JPH05287163A - Thermoplastic resin composition - Google Patents

Abstract

(57) [Summary] [Structure] An aromatic vinyl monomer and a polar functional group-containing vinyl monomer, particularly an epoxy group-containing vinyl monomer or a carboxyl group-containing vinyl monomer, are added to a molten propylene polymer. A thermoplastic resin composition comprising a modified polypropylene obtained by a melt-kneading polymerization reaction in combination and a polyamide resin. [Effect] The composition of the present invention is excellent in mechanical strength and moldability, is superior to polyamide resin in non-water absorption and impact strength, and is superior to polypropylene in thermal deformability and flexural modulus. Provided is a thermoplastic molding material which is useful as a material and has well-balanced physical properties. It is extremely useful in the plastic molding field.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermoplastic resin composition comprising a modified propylene polymer resin and a polyamide resin, which has excellent heat distortion resistance, impact resistance and rigidity, and is also excellent in non-water absorption. Regarding things.

[0002]

2. Description of the Related Art Polyamide resin is used for abrasion resistance, electrical characteristics,
Since it is excellent in heat distortion resistance and mechanical strength, it is widely used as an engineering resin in various mechanical component materials, but it has drawbacks such as insufficient impact resistance and flexibility, and high water absorption.

Particularly, the water absorption is a problem, and the water-absorbed polyamide resin is not preferable because it tends to contain bubbles and whiten when molded. Further, not only the mechanical strength is greatly lowered by water absorption, but also problems such as dimensional change and deformation occur.

Since the polyamide resin has such drawbacks, its application as an engineering resin is limited, and it is often impossible to take advantage of the excellent characteristics inherent to the polyamide resin.

On the other hand, polypropylene is low in cost and exhibits almost no water absorption, but has a drawback that mechanical strength, particularly physical properties at high temperature, is insufficient. Therefore, attempts have been made to use these resins in combination in order to improve the respective drawbacks of the polyamide resin and polypropylene.

However, even if the polyamide resin and the polypropylene are simply blended by melt-kneading or the like, the compatibility between the two is poor, so that layer peeling occurs and only the surface gloss and the mechanical strength are poor.

To improve this compatibility, for example, a composition using polypropylene obtained by modifying a part or all of polypropylene with a carboxylic acid or an anhydride thereof (Japanese Patent Publication No. 30943/1985, Japanese Patent Laid-Open No. 60-30943). No. 118735), or a composition using polypropylene obtained by further modifying the acid-modified polypropylene with a silane compound (Japanese Patent Publication No.
-74698) and the like have been proposed.

[0008]

However, although these compositions are improved in compatibility by the inclusion of the modified polypropylene, the effect of improving mechanical properties such as strength is not always sufficient.

The present invention solves the problems of these conventional compositions and further improves the compatibility of the polyamide resin and polypropylene, and provides the polyamide resin with excellent wear resistance, electrical characteristics, heat distortion resistance and The object is to obtain a resin composition having both mechanical strength and low water absorption properties of polypropylene.

[0010]

DISCLOSURE OF THE INVENTION As a result of intensive studies to solve the above-mentioned drawbacks of the conventional composition, the present inventors have found that an aromatic vinyl monomer is present in the presence of a propylene polymer in a molten state. It was found that the above object was achieved by blending a modified propylene-based polymer resin obtained by melt-kneading and polymerizing a polar functional group-containing vinyl monomer, and completed the present invention.

That is, the present invention is a modified propylene-based polymer resin (A) obtained by melt-kneading and polymerizing an aromatic vinyl monomer and a polar functional group-containing vinyl monomer with a molten propylene-based polymer. And a polyamide resin (B), wherein the modified propylene polymer resin (A) is contained in an amount of 5 to 95% by weight and the polyamide resin (B) is contained in the thermoplastic resin composition. It is characterized by using 95 to 5% by weight.

The present invention will be described in detail below. (Constitution) The propylene-based polymer of the present invention is a propylene homopolymer and a copolymer of propylene as a main component with another olefin or an ethylenic vinyl monomer (each of which is a copolymer containing propylene at 75% by weight or more). Specifically, there are isotactic polypropylene, propylene-ethylene copolymer, propylene-butene copolymer and the like.
These propylene-based polymers can be used alone or in combination. Further, other polymers can be used as long as the properties of the propylene polymer are not impaired.

Examples of the aromatic vinyl monomer include styrene, methylstyrene, vinyltoluene, vinylxylene, ethylvinylbenzene, isopropylstyrene, chlorostyrene, dichlorostyrene, bromostyrene, etc., which may be used alone or in combination. Used.

Further, the polar functional group-containing vinyl monomer used in combination with the aromatic vinyl monomer is a copolymerizable epoxy group-containing vinyl monomer, hydroxyl group-containing vinyl monomer, carboxylic acid group-containing vinyl monomer. Examples thereof include monomers and oxazoline group-containing vinyl monomers. Preferably, it is an epoxy group-containing vinyl monomer or a carboxyl group-containing vinyl monomer.

The epoxy group-containing vinyl monomer includes, for example, glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, methacryl glycidyl ether and the like, and these may be used alone or in combination. Glycidyl methacrylate is particularly preferable.

Examples of the hydroxyl group-containing vinyl monomer include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate and 2
-Hydroxybutyl methacrylate and the like can be used, and these can be used alone or in combination.

The carboxylic acid group-containing vinyl monomer includes, for example, acrylic acid, methacrylic acid, maleic anhydride, maleic acid and the like and alkyl esters thereof, and these are used alone or as a mixture thereof.

Examples of vinyl monomers containing an oxazoline group include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-oxazoline.

The amount of the aromatic vinyl monomer added is 50% by weight or less, preferably 1 to 35% by weight, based on the propylene polymer. If it exceeds 50% by weight, the performance of polypropylene is impaired, which is not preferable. In order to prevent the modified propylene-based polymer from having a low molecular weight and to improve the compatibility with the polyamide resin, the aromatic vinyl monomer is at least equal to or more than the addition amount of the polar functional group-containing vinyl monomer, preferably 1 ~ 5
It is preferable to add a double amount.

The amount of the polar functional group-containing vinyl monomer added is 10% by weight or less, preferably 0.1 to 5% by weight, based on the propylene polymer. If it exceeds 10% by weight, not only the product may have a low molecular weight but also the composition may have adverse effects such as tackiness, water absorption and mechanical properties.

The radical initiator is easily dissolved in the aromatic vinyl monomer due to the characteristics of the present invention, and the reaction is carried out at the melt-kneading temperature of the propylene-based polymer to obtain a half-life of 1 minute. The decomposition temperature is preferably 130 to 250 ° C. Specific examples include t-butyl peroctate, bis (t-butyl peroxy) trimethylcyclohexane, cyclohexanone peroxide,
Benzoyl peroxide, dicumyl peroxide,
Examples thereof include t-butylperbenzoate, dimethyldi (t-butylperoxy) hexane, dimethyldi (t-butylperoxy) hexyne and the like. The amount of the organic peroxide used is usually 0.1 to 10 parts by weight, preferably 1 to 5 parts by weight, based on 100 parts by weight of the vinyl monomer.

Since polypropylene is a radical-disintegrating polymer unlike polyethylene, it is preferable to add a stabilizer as an additive. However, it is necessary to consider the kind and addition amount so as not to hinder the polymerization of the aromatic vinyl monomer. For example, pentaerythrityl-tetrakis ((di-t-butyl-hydroxyphenyl) propionate), ocdecyl (di-t-butyl-hydroxyphenyl) propionate, thiobis (methyl t-butylphenol), trimethyl-tris (di-t-butyl). Hydroxybenzyl) benzene and other hindered phenol stabilizers, tetrakis (di-t-butylphenyl) biphenylene phosphite, tris (di-t-butylphenyl) phosphite and other phosphorus stabilizers, zinc stearate, calcium stearate, etc. There are antacid adsorbents such as metal soaps, magnesium oxide, and hydrotalcite. The amount of the stabilizer used is usually 0.01 to 1 part by weight, preferably 0.05 to 0.5 part by weight, based on 100 parts by weight of the propylene polymer.

The melt-kneading polymerization reaction of the propylene-based polymer with the aromatic vinyl monomer and the polar functional group-containing vinyl monomer is carried out using a closed container such as a Banbury mixer or a continuous kneader such as an extruder. It can be carried out. Of these, the extruder is preferable when considering industrial production such as granulation. Further, the twin-screw extruder is easier to control the supply of reactants, kneading, polymerization time and the like.

As the method for producing the modified propylene-based copolymer resin, powdery or pelletized propylene-based polymer is supplied to an extruder and heated to 130 to 250 ° C. under pressure to melt the crystalline propylene-based polymer. Then, after the melt-kneading polymerization reaction of the aromatic vinyl monomer and the polar functional group-containing vinyl monomer, the strand discharged from the die is cooled,
Pellet using a pelletizer.

The vinyl monomer may be mixed with the propylene-based polymer in advance and then supplied to the extruder or may be supplied to the propylene-based polymer in a molten state by using a liquid feeder. It is preferable to mix and impregnate the propylene-based polymer.

The radical initiator may be added by dissolving it in the vinyl monomer in advance, or may be added to the mixture of the propylene polymer and the vinyl monomer by using the liquid feeder. The stabilizer is preferably mixed in advance with the propylene polymer by using a Henschel mixer or the like.

Since the propylene-based polymer is a radical-disintegrating polymer unlike the ethylene-based polymer, if the polymer is simply melt-heated, the molecular weight is likely to decrease due to the breaking of the main chain.
Therefore, a modified propylene polymer having a low molecular weight can be obtained by simply melt-kneading a polar functional group-containing vinyl monomer in the presence of an organic peroxide. However, according to the melt-kneading reaction method of the present invention, the aromatic vinyl monomer and the polar functional group-containing vinyl monomer are efficiently graft-reacted by reacting in the presence of a stabilizer, resulting in a decrease in molecular weight. Instead, a modified propylene-based polymer having improved compatibility with a polyamide resin can be obtained.

The polyamide resin in the present invention is a polymer compound having an acid amide (--CONH--) as a repeating unit, which is obtained by ring-opening polymerization of lactam depending on the polymerization mode.
Examples thereof include those obtained by polycondensation of diamine and dibasic acid and those obtained by polycondensation of aminocarboxylic acid. They are,
It has a general name of nylon, such as nylon 6, nylon 12, nylon 9, nylon 11, nylon 6
6, Nylon 610 and the like can be mentioned, but among these, Nylon 6 and Nylon 66 are preferable. Although the molecular weight of the polyamide resin is not particularly limited, one having a relative viscosity (η _rel ) of 0.5 or more, preferably 2.0 or more is usually used.

The composition of the present invention comprises the modified propylene polymer (A) in an amount of 5 to 95% by weight, preferably 20 to 85% by weight, and the polyamide resin (B) in an amount of 95 to 5% by weight, preferably 80 to 15% by weight. %. If the amount of the modified propylene polymer in the composition is less than 5% by weight, the modified propylene polymer cannot provide the effect of improving the low water absorption and the molding processability. On the other hand, if the polyamide resin content is less than 5% by weight, the effect of improving the wear resistance, mechanical properties, heat distortion resistance and the like of the polyamide resin cannot be obtained.

In addition to these essential components, additional components can be added to the composition of the present invention within a range that does not impair the effects of the invention. Unmodified polypropylene may be added as an additional component. In that case, the addition timing may be either first mixing with the modified propylene-based polymer or before mixing with the polyamide resin, but the addition amount of the unmodified polypropylene is 900 with respect to 100 parts of the modified propylene-based polymer.
It should be less than a part. Other additional components include, for example, other thermoplastic resins, rubbers, inorganic fillers, pigments, various stabilizers (antioxidants, light stabilizers, antistatic agents,
Antiblocking agents, lubricants) and the like.

In the thermoplastic resin composition of the present invention, these components are dry blended with a Henschel mixer, a V blender, a ribbon blender, a tumbler blender, etc., and then this mixture is uniaxially or biaxially extruder, roll, Banbury mixer. It is melt-mixed with an equal kneader and pelletized or pulverized before being used for molding. For the molding, any method such as injection molding, hollow molding, extrusion molding and the like can be adopted.

By doing so, the composition of the present invention is
It is possible to obtain a thermoplastic resin composition having a good balance of non-water absorption, heat resistance, rigidity, moisture resistance, paintability and surface property.

[0033]

EXAMPLES Next, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In the following, all parts and% are based on weight unless otherwise specified.

The test methods for the physical properties of the composition and the target physical properties are as follows. Melt index (modified PP): JIS K7210
(2.16 Kg, 230 ° C.) Target 15 or less Delamination: The molding surface was wiped with toluene and the presence or absence of delamination was visually judged.

Thermal Deformability: Measurement JIS K7202 (Vi
Cat temperature Load 5 Kg) Target 130 ° C or more Bending elastic modulus: Measurement JIS K7203 Target 1.5 * 10 ⁴
kg / cm ² or more Impact strength: Measured ASTM D256 Target 6 or more Water absorption rate: Using injection test piece (104 * 50 * 2mm) 2
Calculated by the following formula after immersion for 120 hours at 3 ℃ (Example 1) Production of modified polypropylene A 30 mm twin-screw extruder manufactured by Brabender (Germany) was set to a barrel temperature of 200 ° C (however, a feeder section of 180 ° C) and a die temperature of 210 ° C. Powdered polypropylene (HIPOL B200P, manufactured by Mitsui Petrochemical Co., Ltd.) 930 parts, and Irganox 1010 (stabilizer manufactured by Ciba-Gaiki) Co.
5 parts, phosphite 168 (stabilizer manufactured by Ciba-Gaiki)
0.5 parts and 1 part of calcium stearate (stabilizer) were mixed. 50 parts of styrene, 2 of glycidyl methacrylate
A mixture of 0 parts and 2.1 parts of Perhexin 25B [Dimethyldi (t-butylperoxy) hexin manufactured by NOF CORPORATION] was dry blended with the powdered polypropylene compound. The resulting dry blend is fed to the extruder and
The mixture was melt-kneaded at rpm to carry out a graft reaction and passed through a pelletizer to obtain 960 parts of product pellets. 4.8 percent styrene content from the calibration curve using the ratio of the styrene content of the extruded product using an infrared spectroscopic analysis of the product 700 cm ^-1 (assigned to styrene) and 1380 cm ^-1 (assigned to polypropylene) there were.

Production of Thermoplastic Resin Composition 400 parts of the modified propylene-based polymer obtained above and 600 parts of nylon-6 (nylon MC112 manufactured by Kanebo Co., Ltd.) were blended, and this was heated to 240 ° C. using a twin-screw extruder. And kneaded into pellets. The obtained pellets are manufactured by Toshiba IS50A
Using an M injection molding machine, test pieces were prepared under the condition of a resin temperature of 270 ° C., and various physical properties were evaluated. The results are shown in Tables 1 and 2.

Example 2 Instead of using 400 parts of the modified propylene-based polymer and 600 parts of nylon-6 (MC112 manufactured by Kanebo Co., Ltd.) in the production of the thermoplastic resin composition of Example 1, the modified propylene-based polymer 700 was used. And 300 parts of nylon-6 (MC112 manufactured by Kanebo Co., Ltd.) were used to prepare a composition, and various physical properties were evaluated in the same manner as in Example 1. The results are shown in Tables 1 and 2.

Example 3 In the production of the modified propylene-based polymer of Example 1, the amount of styrene was increased to 70 parts, and accordingly, powdery polypropylene (Hypol B200) was added.
P, manufactured by Mitsui Petrochemical Co., Ltd.) to 900 parts, and Perhexin 2
A modified polypropylene and a thermoplastic resin composition were produced in the same manner as in Example 1 except that 2.7 parts of 5B (manufactured by NOF CORPORATION) was used, and various physical properties were evaluated. The results are shown in Table 1 and Table 2.
Shown in.

Example 4 In the production of the modified propylene-based polymer of Example 1, 40 parts of methacrylic acid and 50 parts of styrene were used in place of 20 parts of glycidyl methacrylate.
To 900 parts of powdered polypropylene (HIPOL B200P, manufactured by Mitsui Petrochemical Co., Ltd.)
A modified polypropylene was produced in the same manner as in Example 1 except that 2.7 parts of Perhexin 25B (manufactured by NOF CORPORATION) was used. 300 parts of the obtained modified propylene-based polymer and nylon-66 (ULTRAMID112 manufactured by BASF) 7
00 parts were blended, and this was kneaded at 280 ° C. using a twin-screw extruder to form pellets. Using the IS50AM injection molding machine manufactured by Toshiba, test pieces were prepared from the obtained pellets at a resin temperature of 290 ° C., and various physical properties were evaluated. The results are shown in Tables 1 and 2.

[0040]

[Table 1]

[0041]

[Table 2] (Comparative Example 1) In the production of the thermoplastic resin composition of Example 1, the same amount of polypropylene (Hypol B200, manufactured by Mitsui Petrochemical Co., Ltd.) was used instead of using 400 parts of the modified propylene-based polymer. Was manufactured, and various physical properties were evaluated in the same manner as in Example 1. The results are shown in Tables 3 and 4.

Comparative Example 2 Same as Example 1 except that 50 parts of styrene was removed from the production of the modified propylene polymer of Example 1 and 0.6 parts of Perhexin 25B (manufactured by NOF CORPORATION) was added accordingly. Then, a modified polypropylene and a thermoplastic resin composition were produced and various physical properties were evaluated.
The results are shown in Tables 3 and 4.

Comparative Example 3 Instead of using 400 parts of the modified propylene polymer in the production of the thermoplastic resin composition of Example 1, the same amount of commercially available carboxylic acid modified polypropylene (Admer QF540, manufactured by Mitsui Petrochemical Co., Ltd.) was used. Was used to produce a thermoplastic resin composition, and various physical properties were evaluated in the same manner as in Example 1. The results are shown in Tables 3 and 4.

Comparative Examples 4 and 5 Instead of using the modified propylene-based polymer and the polyamide resin in the production of the thermoplastic resin composition of Example 1, a polyamide resin (nylon MC112 manufactured by Kanebo Ltd.) and a polypropylene resin were used for the purpose of physical properties. (Hipol B200, manufactured by Mitsui Petrochemical Co., Ltd.) was used alone to prepare a composition, and various physical properties were evaluated in the same manner as in Example 1. The results are shown in Tables 3 and 4.

[0045]

[Table 3]

[0046]

[Table 4]

[0047]

INDUSTRIAL APPLICABILITY The present invention relates to an aromatic vinyl monomer and a polar functional group-containing vinyl monomer (particularly an epoxy group-containing vinyl monomer or a carboxyl group-containing vinyl monomer) in a molten propylene polymer. A thermoplastic resin composition comprising a modified polypropylene and a polyamide resin obtained by a melt-kneading polymerization reaction in combination with, mechanical strength, excellent moldability, superior to polyamide resin in non-water absorption and impact strength, and Since it is superior to polypropylene in heat deformability and flexural modulus, it is possible to provide a thermoplastic molding material having a good balance of physical properties, which is particularly useful as a packaging container material.

Claims (3)

[Claims] 1. A modified propylene-based polymer resin (A) and a polyamide resin (obtained by melt-kneading and polymerizing an aromatic vinyl monomer and a polar functional group-containing vinyl monomer with a molten propylene-based polymer). B) and a thermoplastic resin composition. 2. A modified propylene polymer resin (A) containing 5 to 5 parts.
The thermoplastic resin composition according to claim 1, wherein 95% by weight and 95 to 5% by weight of the polyamide resin (B) are used. 3. The thermoplastic resin composition according to claim 1, wherein the polar functional group-containing vinyl monomer is an epoxy group-containing vinyl monomer or a carboxyl group-containing vinyl monomer.