JPH11140140A - Preparation of vinyl chloride graft resin and vinyl chloride graft resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a process for preparing a vinyl chloride graft resin possessing excellent impact resistance and appearance and, at the same time, long-term running properties at the time of molding, and to provide a vinyl chloride graft resin compsn. contg. the vinyl chloride graft resin obtd. by the process. SOLUTION: This process for preparing a vinyl chloride graft resin comprises the steps of: copolymerizing a monomer mixture (i) comprising 100 pts.wt. mixture of a (meth)acrylate (a) with a radically polymerizable monomer (b) and 0.1 to 1 pt.wt. polyfunctional monomer (c) to form a core copolymer; graft copolymerizing a monomer mixture (ii) comprising 100 pts.wt. mixture of a (meth)acrylate (a) with a radically polymerizable monomer (b) and 1.5 to 30 pts.wt. polyfunctional monomer (c) to form a shell copolymer, thereby obtaining an acrylic copolymer latex (A); and graft copolymerizing a vinyl chloride monomer therewith.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a high impact resistance
The present invention relates to a method for producing a vinyl chloride graft resin having excellent long-term running properties, and a vinyl chloride graft resin composition containing the vinyl chloride graft resin obtained by the method.

[0002]

2. Description of the Related Art Vinyl chloride resins are widely used in many fields such as piping materials and building materials as materials having excellent properties such as mechanical strength, weather resistance and chemical resistance.
However, molded articles made of a vinyl chloride-based resin have a drawback that when used for hard materials, they are inferior in impact resistance. Therefore, various improved methods have been conventionally proposed.

[0003] Japanese Patent Application Laid-Open No. 60-255813 discloses a material suitable for applications requiring impact resistance and weather resistance.
A vinyl chloride resin in which vinyl chloride is graft-copolymerized with an acrylic copolymer is disclosed. However,
In this case, the impact resistance of a molded product obtained with an increase in the amount of the added rubber component is improved, but on the other hand, the mechanical strength such as tensile strength and bending elasticity tends to decrease.

[0004] Japanese Patent Application Laid-Open No. Hei 8-225622 discloses a vinyl chloride-based copolymer which is intended to solve the above-mentioned problems by graft copolymerizing vinyl chloride to an acrylic copolymer latex having a core-shell structure. Resins are disclosed. However, in the case of extrusion molding, if molded over a long period of time, the surface of the molded product will have burrs or streaks, and a molded product with a good surface condition can be stably obtained for a long period of time. Was not obtained, and the long-term running property was poor.

[0005]

SUMMARY OF THE INVENTION In view of the above, it is an object of the present invention to provide a vinyl chloride graft resin which is capable of obtaining a molded article excellent in impact resistance and appearance and excellent in long-term running property during molding. And a vinyl chloride-based graft resin composition containing the vinyl chloride-based graft resin obtained by the method.

[0006]

According to the present invention, 51 to 100% by weight of (meth) acrylate (a) having a glass transition temperature of a homopolymer of -140 to 30 ° C.
A monomer mixture (i) consisting of 100 parts by weight of a mixture of a acrylate (a) and a radical polymerizable monomer (b) copolymerizable with 0 to 49% by weight, and 0.1 to 1 part by weight of a polyfunctional monomer (c) ) Is copolymerized to form a core copolymer, and then, on the outer portion of the core copolymer, a (meth) acrylate (a) 51- (h) having a glass transition temperature of a homopolymer of −140 to 30 ° C. A mixture 100 of 100% by weight and 0 to 49% by weight of a radical polymerizable monomer (b) copolymerizable with the (meth) acrylate (a).
Graft copolymerization of 20 to 70% by weight of a monomer mixture (ii) comprising 1.5 to 30 parts by weight of a polyfunctional monomer (c) with respect to 30 to 80% by weight of the core copolymer. Forming a shell copolymer to obtain an acrylic copolymer latex (A) having a core-shell structure having an average particle diameter of 0.08 to 0.30 μm (A); A step of graft copolymerizing 70 to 99% by weight of a vinyl chloride monomer with respect to 1 to 30% by weight of the copolymer latex (A) (I)
This is a method for producing a vinyl chloride graft resin comprising Ia). Hereinafter, the present invention will be described in detail.

In the method for producing a vinyl chloride graft resin according to the first aspect of the present invention, first, as a step (Ia), a monomer copolymer (i) is copolymerized to form a core copolymer, and then the monomer mixture (ii) Is copolymerized with the above-mentioned core copolymer to form a shell copolymer to obtain an acrylic copolymer latex (A) having a core-shell structure.

The above monomer mixture (i) comprises (meth) acrylate (a), radically polymerizable monomer (b), and polyfunctional monomer (c). In the present specification, “(meth) acrylate” includes both methacrylate and acrylate. The above (meth) acrylate (a) has a homopolymer having a glass transition temperature of −140 to 30 ° C. (Meth) acrylates having a glass transition temperature lower than -140 ° C are not industrially common, and if the temperature exceeds 30 ° C, the flexibility at room temperature decreases, so that the range is limited to the above range. Preferably, it is -100 to -40C.

The glass transition temperature of the homopolymer is -14.
The (meth) acrylate (a) at 0 to 30 ° C is not particularly limited. For example, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl (meth) acrylate, isobutyl acrylate, s-butyl acrylate , Cumyl acrylate, n-hexyl (meth) acrylate, n-
Heptyl (meth) acrylate, n-octyl (meth)
Acrylate, 2-methylheptyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, n-nonyl (meth) acrylate, 2-methyloctyl (meth) acrylate, 2-ethylheptyl (meth) acrylate, n-decyl (meth) ) Acrylate, lauryl (meth) acrylate, cyclohexyl acrylate,
Alkyl (meth) acrylates such as myristyl (meth) acrylate, palmityl methacrylate, and stearyl methacrylate; 2-hydroxyethyl acrylate, 2-hydroxypropyl (meth) acrylate, and the like. These may be used alone or in combination of two or more. The glass transition temperatures of these (meth) acrylate homopolymers are described in "Polymer Data
Handbook (Basic Edition) "(published by Baifukan, edited by The Society of Polymer Science, Japan).

The radically polymerizable monomer (b) is copolymerizable with the (meth) acrylate (a). The radical polymerizable monomer (b) is added for the purpose of lowering the viscosity of the obtained vinyl chloride graft resin at the time of molding and improving the weather resistance and chemical resistance of the molded product.

The radical polymerizable monomer (b) is not particularly restricted but includes, for example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, s-butyl methacrylate, t-butyl (meth) acrylate, Alkyl (meth) acrylates such as cumyl methacrylate, cyclohexyl methacrylate, palmityl methacrylate, stearyl acrylate;
Polar group-containing vinyl monomers such as hydroxyethyl methacrylate and 2-acryloyloxyethyl phthalic acid; styrene, α-methylstyrene, p-methylstyrene, p
Aromatic vinyl monomers such as chlorostyrene; unsaturated nitriles such as acrylonitrile and methacrylonitrile; vinyl esters such as vinyl acetate and vinyl propionate. These may be used alone or in combination of two or more.

In the monomer mixture (i), the mixing ratio of the (meth) acrylate (a) and the radical polymerizable monomer (b) is based on 51 to 100% by weight of the (meth) acrylate (a). And the above-mentioned radical polymerizable monomer (b) is 0 to 49% by weight. When the mixing ratio of the radical polymerizable monomer (b) exceeds 49% by weight, the flexibility of the latex is impaired, and the impact resistance of the molded product is reduced. Preferably,
The radical polymerizable monomer (b) is contained in an amount of 0 to 30% by weight based on 70 to 100% by weight of the (meth) acrylate (a).

The polyfunctional monomer (c) crosslinks the obtained core copolymer, prevents breakage of the acrylic copolymer latex particles during molding, and improves the impact resistance of the molded article. Furthermore, it is added for the purpose of making it difficult for coalescing of the acrylic copolymer latex particles during and after production.

The polyfunctional monomer (c) is not particularly restricted but includes, for example, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, 1,6-hexanediol. Di (meth) acrylates such as di (meth) acrylate and trimethylolpropane di (meth) acrylate; trimethylolpropane tri (meth) acrylate, ethylene oxide-modified trimethylolpropane tri (meth) acrylate, pentaerythritol tri (meth) acrylate And the like. Other polyfunctional monomers other than these include, for example, pentaerythritol tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, diallyl phthalate, diallyl maleate, diallyl fumarate, diallyl succinate, triallyl Diallyl compounds or triallyl compounds such as isocyanurate; and divinyl compounds such as divinylbenzene and butadiene. These may be used alone or in combination of two or more.

In the monomer mixture (i), the compounding amount of the polyfunctional monomer (c) is based on 100 parts by weight of the mixture of the (meth) acrylate (a) and the radical polymerizable monomer (b). , 0.1 to 1 part by weight. If the amount is less than 0.1 part by weight, phase mixing of the core copolymer and the shell copolymer occurs, and the impact resistance of the molded article decreases. If the amount exceeds 1 part by weight, the impact resistance is increased due to excessive crosslinking density. Therefore, the range is limited to the above range because it is difficult to obtain the property. Preferably, it is 0.2 to 0.5 parts by weight.

The monomer mixture (ii) comprises the (meth) acrylate (a), the radical polymerizable monomer (b), and the polyfunctional monomer (c), similarly to the monomer mixture (i). The monomer mixture (ii) may have the completely same configuration as the monomer mixture (i), or may have a different configuration.

In the monomer mixture (ii), the mixing ratio of the (meth) acrylate (a) and the radical polymerizable monomer (b) is the same as that in the monomer mixture (i).

In the monomer mixture (ii), the blending amount of the polyfunctional monomer (c) is set to 1. based on 100 parts by weight of the mixture of the (meth) acrylate (a) and the radical polymerizable monomer. 5 to 30 parts by weight. If the amount is less than 1.5 parts by weight, the viscosity of the latex increases due to the breakage of the shell phase during molding of the obtained vinyl chloride graft resin, and as a result, the appearance of the molded article, particularly the surface property in long-term molding, is reduced. Severely damaged, 3
If it exceeds 0 parts by weight, it is difficult to obtain impact resistance due to excessive crosslinking density, so that it is limited to the above range. Preferably, it is 3 to 12 parts by weight.

The method for forming a core copolymer by copolymerizing the above monomer mixture (i) and the method for forming a shell copolymer by copolymerizing the above monomer mixture (ii) are not particularly limited. However, examples thereof include an emulsion polymerization method and a suspension polymerization method. Among them, the emulsion polymerization method is preferable from the viewpoint of the development of impact resistance and the point that the control of the particle diameter of the latex is relatively easy. In the emulsion polymerization method, an emulsifying dispersant and a polymerization initiator are used. If necessary, a pH adjuster, an antioxidant, and the like may be used.

The above-mentioned emulsifying dispersant is added for the purpose of improving the dispersion stability of the above-mentioned monomer mixture (i) and the above-mentioned monomer mixture (ii) in an emulsion and effecting the polymerization efficiently. The emulsifying dispersant is not particularly limited, and includes, for example, anionic surfactants such as polyoxyethylene nonylphenyl ether sulfate, nonionic surfactants, partially saponified polyvinyl acetate, cellulose dispersants, gelatin and the like. Can be Of these, anionic surfactants are preferably used.

The polymerization initiator is not particularly limited.
For example, water-soluble polymerization initiators such as potassium persulfate, ammonium persulfate, and hydrogen peroxide; organic peroxides such as benzoyl peroxide and lauroyl peroxide; azo initiators such as azobisisobutyronitrile; No.

The above-mentioned emulsion polymerization methods are roughly classified into three methods, namely, a batch polymerization method, a monomer dropping method, and an emulsion dropping method, depending on the difference in the monomer addition method, but are not particularly limited.

The batch polymerization method is, for example, a method in which pure water, an emulsifying dispersant and a monomer mixture are added all at once into a jacketed polymerization reactor, and under a condition of oxygen removal and pressurization under a nitrogen stream. This is a method in which the mixture is sufficiently emulsified by stirring, the inside of the vessel is heated to a predetermined temperature by a jacket, and then a polymerization initiator is added to carry out polymerization.

The above monomer dropping method means, for example, that pure water, an emulsifying dispersant, and a polymerization initiator are put in a polymerization reactor equipped with a jacket, and the reaction is first carried out under a condition of oxygen removal and pressurization under a nitrogen stream. Is heated to a predetermined temperature by a jacket, and then the monomer mixture is added dropwise in a fixed amount to gradually polymerize.

The above-mentioned emulsion dripping method means, for example, that a monomer mixture, an emulsifying dispersant and pure water are sufficiently emulsified by stirring to prepare an emulsifying monomer in advance, and then pure water, polymerization Put the initiator,
Under the conditions of oxygen removal and pressurization under a nitrogen stream,
First, after the inside of the vessel is heated to a predetermined temperature by a jacket, polymerization is carried out by dropping the above-mentioned emulsified monomer by a predetermined amount. In the emulsion dripping method, a part of the emulsified monomer is added at once in the early stage of polymerization (hereinafter referred to as “seed monomer”), and thereafter, the amount of the seed monomer is changed by dropping the remaining emulsified monomer. The particle size of the produced latex can be easily controlled.

The above-mentioned monomer mixture (ii) is graft-copolymerized on the outer side of the core copolymer comprising the above-mentioned monomer mixture (i) to form a shell copolymer, and an acrylic copolymer having a core-shell structure is obtained. The method for obtaining the polymer latex (A) is not particularly limited. For example, the above-mentioned monomer mixture (i) or its emulsified monomer is added or dropped at a time in a polymerization reactor, and a polymerization reaction is carried out to carry out the core copolymer. Then, the monomer mixture (ii) or its emulsified monomer is newly added or dropped at once, and a polymerization reaction is carried out to form a shell copolymer on the surface of the core copolymer particles. And the like.

In this case, the monomer mixture (ii) is added in an amount of 20 to 70% by weight based on 30 to 80% by weight of the core copolymer. If the content is less than 20% by weight, a vinyl chloride graft resin capable of stably obtaining a molded article having a good surface condition cannot be obtained.
If the content exceeds 0% by weight, the impact resistance of the molded article is reduced, so that it is limited to the above range. Preferably, the monomer mixture (ii) is 20 to 40% by weight based on 60 to 80% by weight of the core copolymer.

When the above-mentioned shell copolymer is polymerized and formed, it may be carried out in the same polymerization step as the polymerization reaction of the above-mentioned core copolymer, or after the above-mentioned core copolymer is polymerized and recovered, Again, the monomer mixture (ii) or its emulsified monomer may be added to carry out the polymerization and formation of the shell copolymer. However, in the latter case, it is necessary to newly add a polymerization initiator or the like during the polymerization reaction of the shell copolymer.

The acrylic copolymer latex (A) obtained after completion of the latex polymerization reaction has a resin solid content of 10 to 60% by weight in consideration of the productivity of the latex and the stability of the polymerization reaction. It is preferred that

The above acrylic copolymer latex (A)
Has an average particle size of 0.08 to 0.30 μm. 0.
When the thickness is less than 08 μm, the impact resistance of the molded product is slightly reduced, and the thickness of the shell layer is reduced, and as a result, the tackiness of the latex is increased. Is reduced to 0.30 μm
When the ratio exceeds, both the impact resistance and the tensile strength of the molded product are reduced, so that the range is limited to the above range. Preferably, 0.1
0 to 0.18 μm.

The above acrylic copolymer latex (A)
For the purpose of improving the mechanical stability of the latex emulsion, a protective colloid agent may be added as necessary after the completion of the latex polymerization reaction.

In the method for producing a vinyl chloride graft resin according to the present invention, the acrylic copolymer latex (A) obtained in the step (Ia) is subjected to a step (IIa). Graft copolymerize a vinyl monomer.

The vinyl chloride monomer may be a vinyl chloride monomer alone, or may be 50% by weight.
A mixture of the above vinyl chloride monomer and a vinyl monomer copolymerizable with the vinyl chloride monomer may be used.

The vinyl monomer copolymerizable with the vinyl chloride monomer is not particularly restricted but includes, for example, vinyl acetate, alkyl (meth) acrylate, alkyl vinyl ether, ethylene, vinyl fluoride, maleimide and the like. These may be used alone or in combination of two or more.

The above acrylic copolymer latex (A)
The mixing ratio of the vinyl chloride monomer to the vinyl chloride monomer is 70 to 99% by weight based on 1 to 30% by weight of the acrylic copolymer latex (A). If the blending ratio of the acrylic copolymer latex (A) is less than 1% by weight, the impact resistance of the molded article becomes insufficient, and the blending ratio of the acrylic copolymer latex (A) is 30% by weight. %, The mechanical strength such as the bending strength and the tensile strength of the molded product is reduced, so that it is limited to the above range. Preferably, the vinyl chloride-based monomer is 80 to 96% by weight based on the acrylic copolymer latex (A) 4 to 20% by weight.

The above acrylic copolymer latex (A)
On the other hand, the method of graft copolymerizing the vinyl chloride monomer is not particularly limited, and examples thereof include a suspension polymerization method, an emulsion polymerization method, a solution polymerization method, and a bulk polymerization method. Of these, in order to carry out the present invention advantageously,
The suspension polymerization method is preferred.

The above acrylic copolymer latex (A)
In contrast, when the vinyl chloride monomer is graft-copolymerized, a coagulant is added to the acrylic copolymer latex (A) for the purpose of reducing the scale adhering in the polymerization reactor during the polymerization. You may.

In the above suspension polymerization method, a dispersant, an oil-soluble polymerization initiator and the like are used. Also, if necessary, p
You may use H adjuster, antioxidant, etc. The dispersant is added for the purpose of improving the dispersion stability of the acrylic copolymer latex (A) and efficiently performing the graft copolymerization of the vinyl chloride monomer. The dispersant is not particularly limited and includes, for example, poly (meth) acrylate, (meth) acrylate-alkyl acrylate copolymer, methylcellulose, ethylcellulose, hydroxypropylmethylcellulose, polyethylene glycol, polyvinyl acetate and parts thereof. Saponified products, gelatin, polyvinylpyrrolidone, starch, maleic anhydride-styrene copolymer and the like can be mentioned. These may be used alone or in combination of two or more.

As the oil-soluble polymerization initiator, a radical polymerization initiator is preferably used because it is advantageous for graft copolymerization. The radical polymerization initiator is not particularly limited. For example, lauroyl peroxide, t-butyl peroxypivalate, diisopropyl peroxydicarbonate, dioctyl peroxydicarbonate, t
Organic peroxides such as -butyl peroxy neodecanoate and α-cumyl peroxy neodecanoate;
Examples include azo compounds such as 2,2-azobisisobutyronitrile and 2,2-azobis-2,4-dimethylvaleronitrile.

The above suspension polymerization method is, for example, specifically, for example,
In a polymerization reactor equipped with a stirrer and a jacket, pure water, the acrylic copolymer latex (A), the dispersant,
The oil-soluble polymerization initiator, and, if necessary, a water-soluble thickener, a polymerization degree regulator, and the like are charged. Thereafter, the air in the polymerization reactor is discharged by a vacuum pump, and the chloride is further stirred under stirring conditions. After charging the vinyl monomer, the polymerization can be carried out by heating the inside of the polymerization reactor with a jacket. Since the graft copolymerization of the vinyl chloride monomer with the acrylic copolymer latex (A) is an exothermic reaction, the temperature in the polymerization reactor, that is, the polymerization temperature, can be controlled by changing the jacket temperature. It is.

The acrylic copolymer latex (A)
After the completion of the graft copolymerization reaction of the vinyl chloride-based monomer with respect to the above, a vinyl chloride-based graft resin can be obtained by removing the unreacted vinyl chloride-based monomer to form a slurry, followed by dehydration drying.

The degree of polymerization of polyvinyl chloride in the vinyl chloride graft resin obtained by the method for producing a vinyl chloride graft resin of the present invention is preferably from 300 to 2,000 in order to exhibit excellent moldability. More preferably, 4
00 to 1600.

The method for producing a vinyl chloride graft resin according to the present invention comprises a core comprising a copolymer having excellent flexibility at room temperature, and a shell comprising a copolymer having a higher crosslinking density than the core. After obtaining an acrylic copolymer latex having a two-layer structure consisting of the following, a vinyl chloride-based monomer is graft-copolymerized to the acrylic copolymer latex to obtain a vinyl chloride-based graft resin. Therefore, the obtained vinyl chloride-based graft resin has sufficient impact resistance. Further, even during high-temperature processing such as melt extrusion molding, since the particle structure of the latex is not easily destroyed, the development of tackiness of the resin due to the destruction of the latex particle structure is suppressed, and the particle size of the latex is reduced. Is appropriately controlled, so that the flow characteristics of the resin during processing are excellent, and as a result, the long-term running property is excellent.

The present invention 2 is directed to (meth) acrylate (a) wherein the homopolymer has a glass transition temperature of -140 to 30 ° C.
100 parts by weight, and 0.1 to 0.1 of the polyfunctional monomer (c)
After forming a core copolymer by copolymerizing 10 parts by weight, a polyfunctional monomer (d) is formed on the outer side of the core copolymer with respect to 40 to 94.5% by weight of the core copolymer. ) Is formed by graft copolymerization of 0.5 to 10% by weight to form an intermediate layer.
A shell copolymer is formed by copolymerizing 5 to 59.5% by weight of a radical polymerizable monomer (e) having a glass transition temperature of a homopolymer of 30 to 180 ° C.
Step (Ib) of obtaining an acrylic copolymer latex (B) having an intermediate layer / shell structure, and 1 to 30% by weight of the acrylic copolymer latex (B), a vinyl chloride monomer 70 to 99% This is a method for producing a vinyl chloride-based graft resin, comprising a step (IIb) of graft-copolymerizing by weight%.

In the method for producing a vinyl chloride graft resin according to the second aspect of the present invention, first, as a step (Ib), a (meth) acrylate (a) and a polyfunctional monomer (c) are copolymerized to form a core copolymer. After forming the coalesced, an intermediate layer is formed by graft copolymerizing a polyfunctional monomer (d) on the outer portion of the core copolymer,
A shell copolymer is formed by copolymerizing the radical polymerizable monomer (e) on the outer portion of the intermediate layer to obtain an acrylic copolymer latex (B) having a core-intermediate-shell structure.

The (meth) acrylate (a) and the polyfunctional monomer (c) are those described in detail in the present invention 1. The compounding amount of the polyfunctional monomer (c) is based on 100 parts by weight of the (meth) acrylate (a).
0.1 to 10 parts by weight. When the amount is less than 0.1 part by weight, phase mixing of the core copolymer and the shell copolymer occurs, and the impact resistance of the molded article decreases. Since it is difficult to obtain impact properties, it is limited to the above range. Preferably, 0.2 to 3
Parts by weight.

The above polyfunctional monomer (d) comprises a core layer
In addition to cross-linking the polymer between the shell layers to increase the grafting efficiency of both layers and not only firmly fixing the shell layer to the core layer,
A cross-linking layer is formed on the outer surface of the core layer, and functions to prevent the core copolymer from being destroyed by stress during molding. As the polyfunctional monomer (d), one or more of those exemplified as the polyfunctional monomer (c) are used.

The radical polymerizable monomer (e) has a glass transition temperature of a homopolymer of 30 to 180 ° C. When the temperature is lower than 30 ° C., the obtained vinyl chloride graft resin has insufficient tackiness at a high temperature at the time of molding.
Those exceeding ℃ are not industrially common and are limited to the above range. Preferably, it is 60 to 150 ° C.

The homopolymer has a glass transition temperature of 30 to
The radical polymerizable monomer (e) at 180 ° C. is not particularly limited. For example, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, isobutyl methacrylate, s-
Alkyl (meth) acrylates such as butyl methacrylate, t-butyl (meth) acrylate, cumyl methacrylate, cyclohexyl methacrylate, palmityl acrylate, and stearyl acrylate; and polar groups such as 2-hydroxyethyl methacrylate and 2-acryloyloxyethyl phthalic acid Vinyl monomer; styrene, α
Aromatic vinyl monomers such as -methylstyrene, p-methylstyrene, p-chlorostyrene; acrylonitrile,
Unsaturated nitriles such as methacrylonitrile; vinyl acetate,
And vinyl esters such as vinyl propionate. These may be used alone or in combination of two or more. If necessary, the polyfunctional monomer (c) can be used in combination. The glass transition temperature of the homopolymer of these radical polymerizable monomers is
According to “Polymer Data Handbook (Basic)” (published by Baifukan, edited by The Society of Polymer Science).

After forming the core copolymer by copolymerizing the (meth) acrylate (a) and the polyfunctional monomer (c), the polyfunctional monomer (d) is added to the outer portion of the core copolymer. To form an intermediate layer by graft copolymerization of the above, and further to form a shell copolymer by copolymerizing a radical polymerizable monomer (e) on the outer portion of the intermediate layer. The method for obtaining the acrylic copolymer latex (B) having the structure is not particularly limited, and examples thereof include an emulsion polymerization method and a suspension polymerization method. Of these, aspects of the development of impact resistance, and,
Since the control of the particle size of the latex is relatively easy,
Emulsion polymerization is preferred.

The above acrylic copolymer latex (B)
Can be suitably produced by the emulsion polymerization method described in detail in the present invention 1, but is particularly suitable for producing particles having a multilayer structure and can increase the grafting efficiency. It can be suitably manufactured by the method.

Specifically, for example, it is carried out as follows. First, a mixed monomer composed of the (meth) acrylate (a) and the polyfunctional monomer (c) or an emulsified monomer thereof is dropped into a polymerization reactor, and a polymerization reaction is performed to form a core copolymer. Subsequently, the polyfunctional monomer (d) or its emulsified monomer was dropped, and a graft crosslinking reaction was performed on the core copolymer to contain unreacted crosslinking points on the surface of the core copolymer. An intermediate layer of the crosslinked polymer is formed. Further, the radical polymerizable monomer (e) or its emulsified monomer is newly added dropwise,
The acrylic copolymer latex (B) is obtained by copolymerizing a crosslinked polymer to form a shell copolymer on the surface of the intermediate layer.

In this case, in order to improve the graft efficiency between the core layer and the shell layer, the timing of dropping the polyfunctional monomer (d) for the intermediate layer is determined by the above (meth) acrylate (a) and the above-mentioned polyfunctional monomer (d). It is preferable to overlap the last stage of the addition of the mixed monomer comprising the functional monomer (c) and the first stage of the addition of the radical polymerizable monomer (e).

The above acrylic copolymer latex (B)
In the case of preparing the above, the mixing ratio of each component is 40 to 94.5% by weight of the core copolymer, 0.5 to 10% by weight of the polyfunctional monomer (d), and 5 to 10% by weight of the radical polymerizable monomer (e). ５９59.5% by weight. When the blending ratio of the polyfunctional monomer (d) is less than 0.5% by weight, the graft efficiency is low, and the shape preservability of the core copolymer is also reduced. If it exceeds 10% by weight, the impact resistance is lowered due to an excessively high crosslinking density. If the content of the radical polymerizable monomer (e) is less than 5% by weight, the effect of preventing the tackiness of the latex cannot be sufficiently obtained, so that a molded article having a good surface condition can be stably obtained. When the content exceeds 59.5% by weight, the flexibility of the latex is lost, and the impact resistance of the molded product is reduced. Preferably, the core copolymer 68 to
89.5% by weight of the polyfunctional monomer (d) 0.5 to
2% by weight, the above radical polymerizable monomer (e) 10 to 3
0% by weight.

The acrylic copolymer latex (B) obtained after the completion of the latex polymerization reaction has a resin solid content of 10 to 60% by weight in consideration of the productivity of the latex and the stability of the polymerization reaction. Preferably, it is

The above acrylic copolymer latex (B)
Has an average particle diameter of preferably 0.01 to 1.0 μm.
If it is less than 0.01 μm, the impact resistance of the molded article will be slightly reduced, and if it exceeds 1.0 μm, both the impact resistance and the tensile strength of the molded article will be reduced.

The above acrylic copolymer latex (B)
For the purpose of improving the mechanical stability of the latex emulsion, a protective colloid agent may be added as necessary after the completion of the latex polymerization reaction.

In the method for producing a vinyl chloride graft resin according to the second aspect of the present invention, next, in the step (IIb), the acrylic copolymer latex (B) obtained in the step (Ib) is A vinyl chloride monomer is graft-copolymerized. The step (IIb) can be carried out in the same manner as the step (IIa) described in detail in the first invention.

The method for producing a vinyl chloride-based graft resin of the present invention 2 comprises a core portion made of a copolymer having a low glass transition temperature and excellent flexibility at room temperature, a glass portion having a high glass transition temperature, The shell part made of a copolymer having the function of suppressing the adhesiveness of the latex and the polymer between the core and shell layers are cross-linked to increase the grafting efficiency of both layers, and the function of firmly fixing the shell part to the core part surface. Having, further, after obtaining an acrylic copolymer latex consisting of an intermediate layer having an action of preventing the core portion from being broken by stress during molding by forming a crosslinked layer on the outer surface of the core portion, A vinyl chloride-based graft resin is obtained by graft-copolymerizing a vinyl chloride-based monomer. Therefore, the obtained vinyl chloride-based graft resin has sufficient impact resistance, and even during high-temperature processing such as melt extrusion molding, generation of mold adhering matter which causes poor appearance of the molded product. Is prevented, and excellent in long-term running property.

In the present invention 3, (meth) acrylate (a) wherein the homopolymer has a glass transition temperature of -140 to 30 ° C.
51 to 100% by weight of a radical polymerizable monomer (b) copolymerizable with the (meth) acrylate (a)
And a monomer mixture (iii) consisting of 0.1 to 30 parts by weight of a polyfunctional monomer (c) at a polymerization temperature of 50 to 75 ° C. After the coalescence was formed, the glass transition temperature of the homopolymer was -140 on the outer side of the core copolymer.
(Meth) acrylate (a) 51 to 10
100 parts by weight of a mixture of 0% by weight, 0 to 49% by weight of a radical polymerizable monomer (b) copolymerizable with the (meth) acrylate (a), and a polyfunctional monomer (c)
A copolymer obtained by copolymerizing a monomer mixture (vi) consisting of 1.5 to 30 parts by weight at a polymerization temperature of 5 to 50 ° C. was added in an amount of 20 to 70% by weight based on 30 to 80% by weight of the core copolymer.
A step (Ic) of obtaining a core-shell structure acrylic copolymer latex (C) by forming a shell copolymer by graft polymerization by weight%, and the acrylic copolymer latex (C) 1 Step (IIc) of graft copolymerizing 70 to 99% by weight of a vinyl chloride monomer with respect to about 30% by weight.

In the method for producing a vinyl chloride graft resin according to the third aspect of the present invention, first, as in the first aspect, the step (I)
c) forming a core copolymer by copolymerizing the monomer mixture (iii) and then forming a shell copolymer by copolymerizing the monomer mixture (vi) with the core copolymer. Thus, an acrylic copolymer latex (C) having a core-shell structure is obtained.

The monomer mixture (iii) and the monomer mixture (vi) are composed of a (meth) acrylate (a), a radical polymerizable monomer (b), and a polyfunctional monomer (c). It is described. The monomer mixture (vi) may have a completely same configuration as the monomer mixture (iii), or may have a different configuration.

In the monomer mixture (iii) and the monomer mixture (vi), the mixing ratio of the (meth) acrylate (a) and the radical polymerizable monomer (b) is Above (meta)
The radical polymerizable monomer (b) is 0 to 49% by weight based on 51 to 100% by weight of the acrylate (a).

In the above monomer mixture (iii),
The compounding amount of the polyfunctional monomer (c) is the same as the above (meth)
0.1 to 30 parts by weight per 100 parts by weight of the mixture of the acrylate (a) and the radical polymerizable monomer (b)
Parts by weight. If the amount is less than 0.1 part by weight, phase mixing of the core copolymer and the shell copolymer occurs, and the impact resistance of the molded article decreases. If the amount exceeds 30 parts by weight, the impact resistance is increased due to excessive crosslinking density. Therefore, the range is limited to the above range because it is difficult to obtain the property. Preferably it is 0.1 to 1 part by weight.

In the monomer mixture (vi), the addition of the polyfunctional monomer (c) is indispensable, and the amount of the polyfunctional monomer (c) depends on the amount of the (meth) acrylate (a) and the radical polymerizable monomer (b). It is 1.5 to 30 parts by weight based on 100 parts by weight of the mixture. When the amount is less than 1.5 parts by weight, the shell phase is broken during molding of the obtained vinyl chloride graft resin, so that the tackiness of the latex is increased, and as a result, the appearance of the molded article, particularly the surface property in long-term molding When the content exceeds 30 parts by weight, it becomes difficult to obtain impact resistance due to excessive crosslinking density, so that the content is limited to the above range. Preferably, it is 3 to 12 parts by weight.

The method of forming the core copolymer by copolymerizing the monomer mixture (iii) and the method of forming the shell copolymer by copolymerizing the monomer mixture (vi) are not particularly limited. Examples include an emulsion polymerization method and a suspension polymerization method. Among these, the emulsion polymerization method is preferred from the viewpoint of impact resistance development and the relative ease of controlling the particle size of the latex. In the emulsion polymerization method, an emulsifying dispersant and a polymerization initiator are used. Also, if necessary, a pH adjuster,
An antioxidant or the like may be used.

In the present invention 3, when synthesizing the copolymer latex containing the acrylic polymer, first, a core copolymer is synthesized at a polymerization temperature of 50 to 75 ° C., and a shell copolymer is polymerized on the outside thereof. It is characterized in that it is formed at a temperature of 5 to 50 ° C., and the obtained acrylic copolymer latex has a two-layer structure of a core part having a low degree of polymerization and a shell part having a high degree of polymerization. A vinyl chloride-based graft resin having both long-term running properties is obtained. In the polymerization of the shell portion, when the temperature is lower than 5 ° C., the activity of the polymerization catalyst is remarkably reduced, so that the polymerization speed is slow, the polymerization requires a long time, and the polymerization may be substantially difficult. Therefore, as described above,
The polymerization temperature is preferably from 5 to 50 ° C, more preferably from 20 to 50 ° C.

The above-mentioned emulsifying dispersant is used for the same purpose as in the present invention 1, and the emulsifying dispersant is not particularly limited, and those similar to the present invention 1 are preferably used.

As the above polymerization initiator, it is necessary to add the polymerization initiator twice during the polymerization of the core copolymer and during the polymerization of the shell copolymer. First, at the time of polymerization of the core copolymer, there is no particular limitation, and examples thereof include those similar to the first embodiment. At the time of shell copolymer polymerization, since polymerization is carried out at a low temperature, a redox polymerization initiator is preferable.For example, potassium persulfate, ammonium persulfate and sodium bisulfite, formaldehyde sodium sulfoxylate dihydrate, sodium pyrobisulfite Combinations of t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, p-menthane hydroperoxide and other organic peroxides with sodium bisulfite, formaldehyde sodium sulfoxylate dihydrate, sodium pyrobisulfite Combination: a combination of an organic peroxide such as t-butyl peroxyisopropyl carbonate, t-butyl peroxybenzoate, diisopropyl peroxy carbonate and ferrous sulfate, and the like. That. Among these, a combination of a persulfate and a reducing agent is particularly preferable in that polymerization can be stably promoted.

The emulsion polymerization method is roughly classified into three methods, namely, a batch polymerization method, a monomer dropping method, and an emulsion dropping method, as described in the present invention 1 due to the difference in the monomer addition method, but is not particularly limited. Not something.

The shell copolymer is formed by graft copolymerizing the monomer mixture (vi) on the outside of the core copolymer composed of the monomer mixture (iii) to form an acrylic copolymer having a core-shell structure. The method for obtaining the coalesced latex (C) is not particularly limited, and includes, for example, the same method as in the first invention.

The monomer mixture (vi) is used in an amount of 20 to 70% by weight based on 30 to 80% by weight of the core copolymer.
Is added. When the amount is less than 20% by weight, a vinyl chloride graft resin capable of stably obtaining a molded article having a good surface condition cannot be obtained.
Since the impact resistance of the molded article is reduced, it is limited to the above range, and preferably 40 to 70% by weight of the core copolymer.
Is 30 to 60% by weight.

The acrylic copolymer latex (C) obtained after the completion of the latex polymerization reaction has a resin solid content of 10 to 60% by weight in consideration of the productivity of the latex and the stability of the polymerization reaction. Preferably, it is

The above acrylic copolymer latex (C)
Has an average particle diameter of preferably 0.01 to 0.3 μm.
When the thickness is less than 0.01 μm, the impact resistance of the molded product is slightly reduced, and the thickness of the shell layer is reduced, and as a result, the tackiness of the latex is increased. Running performance decreases, 0.3μ
If it exceeds m, both the impact resistance and the tensile strength of the molded article decrease, so the above range is preferable. More preferably 0.08
０．３0.3 μm.

The above acrylic copolymer latex (C)
For the purpose of improving the mechanical stability of the latex emulsion, a protective colloid agent may be added as necessary after the completion of the latex polymerization reaction.

In the method for producing a vinyl chloride graft resin according to the third aspect of the present invention, next, in the step (IIc), the acrylic copolymer latex (C) obtained in the step (Ic) is used A vinyl chloride monomer is graft-copolymerized. The step (IIc) can be carried out in the same manner as the step (IIa) described in detail in the first invention.

The method for producing a vinyl chloride graft resin according to the third aspect of the present invention comprises a core portion made of a low-polymerization degree copolymer having excellent flexibility at ordinary temperature, a cross-linking density higher than that of the core portion, and a higher polymerization degree. After obtaining an acrylic copolymer latex having a two-layer structure composed of a shell portion composed of the above copolymer, a vinyl chloride monomer is graft-copolymerized to obtain a vinyl chloride graft resin. Therefore, the obtained vinyl chloride graft resin has sufficient impact resistance,
In addition, even during high-temperature processing such as melt extrusion molding, since the particle structure of the latex is hard to be broken, the development of tackiness due to the breakage of the latex particle structure is suppressed, and the particle size of the latex is also appropriate. , The flow characteristics of the resin during processing are excellent, and as a result, the long-term running property is excellent.

The present invention 4 is a vinyl chloride graft resin composition containing a vinyl chloride graft resin obtained by the method for producing a vinyl chloride graft resin according to any one of the present inventions 1 to 3.

The vinyl chloride graft resin composition of the present invention 4 comprises a vinyl chloride graft resin obtained by the method for producing a vinyl chloride graft resin of the present invention 1 to 3;
Further, it is composed of various additives conventionally used generally in molding and processing of a vinyl chloride resin.

The additives are not particularly restricted but include, for example, heat stabilizers, stabilizing aids, lubricants, processing aids, antioxidants, light stabilizers, fillers, pigments and the like. The heat stabilizer is not particularly limited, for example, dimethyltin mercapto, dibutyltin mercapto, dioctyltin mercapto, dibutyltin malate, dibutyltin maleate polymer, dioctyltin malate, dioctyltin maleate polymer, dibutyltin laurate, dibutyl Organic tin stabilizers such as tin laurate polymers; calcium-zinc stabilizers;
Barium-zinc-based stabilizers, barium-cadmium-based stabilizers and the like can be mentioned.

The stabilizing aid is not particularly limited.
For example, epoxidized soybean oil, epoxidized linseed oil, epoxidized tetrahydrophthalate, epoxidized polybutadiene, phosphate ester and the like can be mentioned.

The lubricant is not particularly restricted but includes, for example, montanic acid wax, paraffin wax, polyethylene wax, stearic acid, stearyl alcohol, butyl stearate and the like.

The processing aid is not particularly limited, and examples thereof include an acrylic processing aid which is an alkyl acrylate / alkyl methacrylate copolymer having a weight-average molecular weight of 100,000 to 2,000,000. For example, n-butyl acrylate / methyl methacrylate copolymer, 2-ethylhexyl acrylate / methyl methacrylate / butyl methacrylate copolymer and the like can be mentioned.

The antioxidant is not particularly limited.
For example, phenolic antioxidants and the like can be mentioned. The light stabilizer is not particularly limited, for example, salicylic acid ester type, benzophenone type, benzotriazole type,
UV absorbers such as cyanoacrylates; hindered amine light stabilizers;

The filler is not particularly restricted but includes, for example, calcium carbonate and talc. The pigment is not particularly limited and includes, for example, organic pigments such as azo-based, phthalocyanine-based, sulene-based, and dye lake-based; oxide-based, molybdenum chromate-based, sulfide / selenide-based, and ferrocyanide-based. And inorganic pigments.

A plasticizer may be added to the vinyl chloride graft resin composition of the present invention 4 for the purpose of improving the processability during molding. The plasticizer is not particularly limited,
For example, dibutyl phthalate, di-2-ethylhexyl phthalate, di-2-ethylhexyl adipate and the like can be mentioned.

The method of mixing the above additives with the above vinyl chloride graft resin is not particularly limited, and examples thereof include a method using hot blending and a method using cold blending. The method for molding the vinyl chloride-based graft resin composition of the present invention 4 is not particularly limited, and examples thereof include an extrusion forming method, an injection molding method, a calendar molding method, and a press molding method.

The vinyl chloride graft resin composition of the present invention 4 can provide a molded article having excellent impact resistance, and has excellent flow characteristics at the time of working and molding, and therefore has excellent long-term running properties. I have. Therefore, it is suitably used for applications such as pipes, joints, outer walls, and soundproof walls having irregular cross sections, which require high impact resistance. Further, it can be suitably used for window frames, sashes, and the like that require good moldability.

[0089]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 Preparation of Acrylic Copolymer Latex First, according to the composition table shown in Table 1, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), -Ethylhexyl acrylate (hereinafter, referred to as "2-EHA") and trimethylolpropane triacrylate (hereinafter, referred to as "TMPTA") were mixed and stirred to prepare an emulsifying monomer for forming a core copolymer. Also, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), n-butyl acrylate (hereinafter referred to as “n-BA”), and TMPTA are mixed and stirred to form an emulsion for forming a shell copolymer. A monomer was prepared.

Pure water was charged into the polymerization reactor, and oxygen in the reactor was replaced with nitrogen.
The temperature was raised to 0 ° C. Ammonium persulfate (hereinafter, referred to as “APS”) and 20% by weight of the emulsifying monomer for forming a core copolymer were collectively charged as a seed monomer into the polymerization reactor in which the temperature was raised, and polymerization was started. Subsequently, the remainder of the core copolymer-forming emulsifying monomer was added dropwise. As soon as the dropping of the emulsifying monomer for forming the core copolymer system was completed, the dropping of the emulsifying monomer for forming the shell copolymer was started. The dropping of all the emulsified monomers was completed in 3 hours, and after an aging period of 1 hour, the polymerization was terminated, and an acrylic copolymer latex having a solid concentration of about 30% by weight (hereinafter referred to as “latex”) ) Got.

[Preparation of vinyl chloride graft resin] Then, pure water, the above latex, a 3% aqueous solution of partially saponified vinyl acetate, t-butyl peroxy neodecanoate were placed in a polymerization reactor equipped with a stirrer and a jacket. , Α-cumyl peroxy neodecanoate,
The air in the polymerization reactor was discharged by a vacuum pump, and vinyl chloride was further added under stirring conditions. Thereafter, polymerization was started at a polymerization temperature of 53.6 ° C. by controlling the jacket temperature. When the pressure in the polymerization reactor dropped to 5.3 kg / cm ^{2, the} termination of the polymerization reaction was confirmed, and the reaction was stopped. Thereafter, the unreacted vinyl chloride monomer was removed, and further dehydration drying was performed to obtain a vinyl chloride-based graft resin having a polymerization degree of vinyl chloride of about 1200. The latex particle diameter, impact resistance, tensile strength and long-term running property of the obtained vinyl chloride graft resin were evaluated by the following methods. The results are shown in Table 1.

(Latex particle diameter) The median diameter measured by a laser diffraction type particle size distribution meter (manufactured by Horiba, Ltd.) is shown.

(Impact resistance) A Charpy impact test was performed according to JIS K 7111. The sample was roll-kneaded at 200 ° C. for 3 minutes at a resin composition obtained by mixing 0.5 parts by weight of an organotin stabilizer and 1.0 part by weight of a montanic acid lubricant with respect to 100 parts by weight of a vinyl chloride graft resin. rear,
A 3 mm-thick press plate obtained by press molding at 200 ° C. for 3 minutes was used. The measurement temperature was 23 ° C.

(Tensile strength) A tensile strength test was performed according to JIS K 7113. The same sample as the press plate used in the above Charpy impact test was used. The measurement temperature was 23 ° C.

(Evaluation of long-term running property) 100 parts by weight of vinyl chloride graft resin, 0.8 parts by weight of organotin stabilizer, 0.5 parts by weight of polyethylene lubricant, 0.2 parts by weight of stearic acid, calcium stearate 0.5 parts by weight,
Then, 3.0 parts by weight of an acrylic processing aid was added, and the mixture was stirred and mixed with a super mixer (100 L, manufactured by Kawata) to obtain a vinyl chloride graft resin composition. The obtained vinyl chloride-based graft resin composition is extruded from a biaxially-oriented extruder having a diameter of 50 mm (BT-50, manufactured by Plastics Engineering Laboratory).
And a 20 mm diameter vinyl chloride resin tube was continuously molded for 24 hours. The inner and outer surfaces of the obtained vinyl chloride resin tube were visually observed, and those having a good surface condition over 24 hours were evaluated as ○, and those having poor appearance such as blur, streak, and unevenness were evaluated as × (× In the case of, the time at which blurring or the like began to occur is also described).

(Examples 2 to 6, Comparative Examples 1 to 6) A vinyl chloride graft resin was prepared and evaluated in the same manner as in Example 1 except that the composition shown in Table 1 was followed. The results are shown in Table 1.

[0098]

[Table 1]

(Example 7) [Preparation of acrylic copolymer latex] First, according to the composition table shown in Table 2, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), n -BA, 2-EHA and TMPT
A was mixed and stirred to prepare an emulsifying monomer for forming a core copolymer. Further, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate) and TMPTA were mixed and stirred to prepare an emulsifying monomer for forming an intermediate layer. Also, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), methyl methacrylate (hereinafter referred to as “MMA”), and TMPTA are mixed,
The mixture was stirred to prepare an emulsion monomer for forming a shell copolymer.

Pure water was charged into the polymerization reactor, and oxygen in the reactor was replaced with nitrogen.
The temperature rose. APS and 25% by weight of the emulsifying monomer for forming a core copolymer were collectively charged as a seed monomer into the polymerization reactor in which the temperature was raised, and polymerization was started.
Subsequently, 70% by weight of the emulsifying monomer for forming the core copolymer was used.
Was added dropwise. Next, the remaining 5% by weight of the emulsifying monomer for forming the core copolymer and 25% by weight of the emulsifying monomer for forming the intermediate layer were simultaneously dropped. Next, 50% by weight of the emulsifying monomer for forming an intermediate layer was dropped. As soon as the dripping is finished,
5% by weight of the emulsifying monomer for forming the shell copolymer and the remaining 25% by weight of the emulsifying monomer for forming the intermediate layer were simultaneously dropped. Subsequently, the remaining 95% by weight of the emulsifying monomer for forming a shell copolymer was added dropwise. After the dropping of all the emulsified monomers was completed in 3 hours, and after an aging period of 1 hour, the polymerization was terminated to obtain a latex having a solid content of about 30% by weight.

[Preparation of Graft Resin Based on Vinyl Chloride] Then, pure water, the above latex, a 3% aqueous solution of partially saponified vinyl acetate, t-butyl peroxy neodecanoate were placed in a polymerization reactor equipped with a stirrer and a jacket. , Α-cumyl peroxy neodecanoate,
The air in the polymerization reactor was discharged by a vacuum pump, and vinyl chloride was further charged under stirring conditions. Then, polymerization was started at a polymerization temperature of 50 ° C. by controlling the jacket temperature. When the pressure in the polymerization reactor dropped to 4.8 kg / cm ^{2, the} completion of the polymerization reaction was confirmed, and the reaction was stopped. Then, by removing unreacted vinyl chloride monomer, and further dehydration drying,
A vinyl chloride graft resin having a polymerization degree of vinyl chloride of about 1400 was obtained.

The impact resistance, tensile strength and long-term running property of the obtained vinyl chloride graft resin were evaluated in the same manner as in Example 1. In the evaluation of long-term running performance, a vinyl chloride resin tube having a diameter of 20 mm
Molding was continued for 4 hours. The inner and outer surfaces of the obtained vinyl chloride resin tube were visually observed, and those having a good surface condition over 24 hours were evaluated as ○, and those having poor appearance such as blur, streak, and unevenness were evaluated as × (× In the case of, the time at which blurring or the like began to occur is also described).

(Examples 8 to 11, Comparative Examples 7 to 15) Table 2
A vinyl chloride-based graft resin was prepared and evaluated in the same manner as in Example 7, except that the composition table shown in Table 1 was followed. The results are shown in Table 2. In Table 2, “PETA” indicates pentaerythritol tetraacrylate. Also,
The amounts of the emulsifying dispersant and the initiator were shown as values based on 100 parts by weight of the monomer. In Comparative Example 9, no intermediate layer was formed.

[0104]

[Table 2]

(Example 12) [Preparation of acrylic copolymer latex] First, according to the composition table shown in Table 3, a predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate), -Mixing EHA and TMPTA,
The mixture was stirred to prepare an emulsifying monomer for forming a core copolymer.
A predetermined amount of pure water, an emulsifying dispersant (polyoxyethylene nonylphenyl ether ammonium sulfate),
n-BA and TMPTA were mixed and stirred to prepare an emulsion monomer for forming a shell copolymer.

After pure water was charged into the polymerization reactor and the oxygen in the reactor was replaced with nitrogen, the polymerization reactor was stirred for 6 hours.
The temperature was raised to 5 ° C. AP is placed in the polymerization reactor where the temperature has been raised.
S and 20% by weight of the emulsifying monomer for forming a core copolymer were collectively charged as a seed monomer, and polymerization was started. Subsequently, the remainder of the core copolymer-forming emulsifying monomer was added dropwise. As soon as the dropping of the core copolymer system-forming emulsifying monomer was completed, the temperature of the polymerization reactor was immediately lowered to 40 ° C., and then the dropping of the shell copolymer-forming emulsifying monomer was started. Dropping of all the emulsified monomers was completed in 3 hours, and after an aging period of 1 hour, the polymerization was terminated to obtain a latex having a solid content of about 30% by weight.

[Preparation of Graft Resin Based on Vinyl Chloride] Then, pure water, the above latex, a 3% aqueous solution of partially saponified vinyl acetate, t-butyl peroxy neodecanoate were placed in a polymerization reactor equipped with a stirrer and a jacket. , Α-cumyl peroxy neodecanoate,
The air in the polymerization reactor was discharged with a vacuum pump, and vinyl chloride was further added under stirring conditions. Thereafter, polymerization was started at a polymerization temperature of 53.6 ° C. by controlling the jacket temperature. When the pressure in the polymerization reactor dropped to 5.3 kg / cm ^{2, the} termination of the polymerization reaction was confirmed, and the reaction was stopped. Thereafter, the unreacted vinyl chloride monomer was removed, and further dehydration drying was performed to obtain a vinyl chloride-based graft resin having a polymerization degree of vinyl chloride of about 1200.

The impact resistance and tensile strength of the obtained vinyl chloride graft resin were evaluated in the same manner as in Example 1. In the evaluation of long-term running properties, the following extrusion was performed into a plate shape, and the time from the start of molding until appearance defects such as blur, streak, and unevenness were examined.

(Evaluation of long-term running property) 100 parts by weight of vinyl chloride graft resin, 0.8 parts by weight of organotin stabilizer, 0.5 parts by weight of polyethylene lubricant, 0.2 parts by weight of stearic acid, calcium stearate 0.5 parts by weight,
Then, 3.0 parts by weight of an acrylic processing aid was added, and the mixture was stirred and mixed with a super mixer (100 L, manufactured by Kawata) to obtain a vinyl chloride graft resin composition. The obtained vinyl chloride graft resin composition was extruded into a plate shape using a plast extruder manufactured by Toyo Seiki Co., Ltd. (biaxial non-intermeshing parallel screw) and a slit mold manufactured by Toyo Seiki Co., Ltd. Observation was performed using an optical microscope. The time required until appearance defects (such as blur, streak, and unevenness) occurred on the sample surface was defined as the running time.

(Examples 13 to 18, Comparative Examples 16 to 19)
Except for following the composition table shown in Table 3, a vinyl chloride-based graft resin was prepared and evaluated in the same manner as in Example 12. The results are shown in Table 3.

[0111]

[Table 3]

[0112]

According to the method for producing a vinyl chloride graft resin of the present invention having the above-mentioned constitution, it is possible to obtain a vinyl chloride graft resin from which a molded article having extremely excellent impact resistance can be obtained. In addition, with respect to the obtained vinyl chloride-based graft resin, a vinyl chloride-based graft resin composition obtained by blending a lubricant, a stabilizer, a pigment, and the like, which are generally used in molding processing of a vinyl chloride-based resin, is used. Excellent in nature,
Even in long-term continuous molding, a molded article having a good surface condition can be stably obtained. Therefore, it can be suitably used as pipes, joints, outer walls, sound-insulating walls having irregular cross sections, etc., which require high impact resistance, and also as window frames, sashes, etc., which require good formability. It can be suitably used.

Claims (4)

[Claims] The glass transition temperature of the homopolymer is -140.
(Meth) acrylate (a) 51 to 10
100 parts by weight of a mixture of 0% by weight, 0 to 49% by weight of a radical polymerizable monomer (b) copolymerizable with the (meth) acrylate (a), and a polyfunctional monomer (c)
After forming the core copolymer by copolymerizing the monomer mixture (i) consisting of 0.1 to 1 part by weight, the glass transition temperature of the homopolymer is -140 to outside the core copolymer. (Meth) acrylate (a) 5 at 30 ° C.
1 to 100% by weight and the (meth) acrylate (a)
Radical polymerizable monomer (b) copolymerizable with
100 parts by weight of a mixture with 100% by weight of a polyfunctional monomer (c) and a monomer mixture (ii) composed of 1.5 to 30 parts by weight of a polyfunctional monomer (c), based on 30 to 80% by weight of the core copolymer. A shell copolymer is formed by graft copolymerization at 70% by weight, and has an average particle size of 0.08 to 0.1%.
Step (Ia) of obtaining an acrylic copolymer latex (A) having a core-shell structure of 30 μm, and 1 to 30% by weight of the acrylic copolymer latex (A), a vinyl chloride monomer 70 A method for producing a vinyl chloride-based graft resin, which comprises a step (IIa) of graft copolymerization of up to 99% by weight. 2. The glass transition temperature of the homopolymer is -140.
After forming a core copolymer by copolymerizing 100 parts by weight of (meth) acrylate (a) having a temperature of ３０30 ° C. and 0.1 to 10 parts by weight of a polyfunctional monomer (c),
On the outer side of the core copolymer, the core copolymer 40 to
An intermediate layer is formed by graft copolymerizing 0.5 to 10% by weight of the polyfunctional monomer (d) with respect to 94.5% by weight, and further, a homopolymer of A shell copolymer is formed by copolymerizing 5 to 59.5% by weight of a radical polymerizable monomer (e) having a glass transition temperature of 30 to 180 ° C. to form a core-intermediate layer.
Step (Ib) of obtaining an acrylic copolymer latex (B) having a shell structure, and 70 to 99% by weight of a vinyl chloride monomer based on 1 to 30% by weight of the acrylic copolymer latex (B). A method for producing a vinyl chloride-based graft resin, comprising a step (IIb) of graft copolymerization. 3. The glass transition temperature of the homopolymer is -140.
(Meth) acrylate (a) 51 to 10
100 parts by weight of a mixture of 0% by weight, 0 to 49% by weight of a radical polymerizable monomer (b) copolymerizable with the (meth) acrylate (a), and a polyfunctional monomer (c)
A monomer mixture consisting of 0.1 to 30 parts by weight (iii)
After forming a core copolymer by copolymerizing at a polymerization temperature of 50 to 75 ° C., on the outer portion of the core copolymer,
(Meth) acrylate (a) having a glass transition temperature of −140 to 30 ° C. and 51 to 100% by weight, and a radical polymerizable monomer (b) 0 copolymerizable with the (meth) acrylate (a). Mixture 100 with ~ 49% by weight
Parts by weight and a monomer mixture (vi) consisting of 1.5 to 30 parts by weight of the polyfunctional monomer (c) at a polymerization temperature of 5 to 5
A copolymer obtained by copolymerizing at 0 ° C. is graft copolymerized with 20 to 70% by weight with respect to 30 to 80% by weight of the core copolymer to form a shell copolymer. Acrylic copolymer latex of structure (C)
And a step (IIc) of graft copolymerizing 70 to 99% by weight of a vinyl chloride monomer with respect to 1 to 30% by weight of the acrylic copolymer latex (C). Characteristic method for producing a vinyl chloride graft resin. 4. A vinyl chloride graft resin composition comprising a vinyl chloride graft resin obtained by the production method according to claim 1.