JPH073115A - Cold-setting emulsion and production thereof - Google Patents

Abstract

PURPOSE:To obtain the emulsion having good shelf stability and curability by the emulsion polymerization of a silylated vinyl monomer and other vinyl monomer in the presence of a specified monoisobutylate. CONSTITUTION:An emulsion obtained by the emulsion polymerization of a vinyl monomer containing a silyl group of the formula and other copolymerizable vinyl monomer in the presence of 2,2,4-trimethyl-1,3-pentanediol monoisobutylate. In the formula, R is a monovalent hydrocarbon group selected from 1-10C alkyl, aryl and aralkyl; X is halogen, alkoxy, hydroxy, acyloxy, aminoxy, phenoxy, thioalkoxy or amino; y is 0 to 2; and when the number of X and R each attached to an Si atom is 2 or greater, X's and R's each may be the same or different.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a room temperature curable emulsion and a method for producing the same, and more specifically, a room temperature curable emulsion used for various coatings on interior and exterior, automobiles, home appliances, plastic products and the like, and a method for producing the same. In particular, the present invention relates to a room temperature curable emulsion having good storage stability and curability, which is used for coating requiring weather resistance and durability, and a method for producing the same.

[0002]

2. Description of the Related Art In recent years, in the field of paints and adhesives, from the viewpoints of pollution control and resource saving, from resins containing organic solvents as components, water-soluble resins or water Attempts have been made to convert to a dispersible resin (hereinafter, also collectively referred to as "water-based resin") as a component.

However, the conventional water-based resin-based coating composition is a cured product because it is strongly affected by the surfactant used during polymerization, mainly because it has no crosslinkable functional group. It has a drawback that the physical properties of the coating film are inferior to those of a coating material containing a resin containing an organic solvent, such that the weather resistance, water resistance and stain resistance of the film are significantly deteriorated.

Therefore, a method has been proposed in which an emulsion having an alkoxysilyl group is applied to a coating material as a crosslinkable emulsion (see Japanese Patent Application Laid-Open No. 3-227312).

However, a new problem arose here. That is, usually, a film formation aid such as butyl cellosolve is added to the emulsion afterwards, but agglomerates (scales) are generated with the addition and the fine coating called “butsu” is formed in the formed coating film. There was a case where there was a convexity.

[0006]

[Means and Actions for Solving the Problems] As a result of intensive studies conducted by the present inventors on the above problems, 2, 2, 4
-By adding trimethyl-1,3-pentanediol monoisobutyrate at the time of emulsion polymerization, the film-forming aid which has been necessary until now can be omitted, and agglomerates (scale) that occur when this is added later. It was found that the problem of the occurrence of the projections and the formation of protrusions called "butsu" formed on the coating film can be solved, and moreover, the same effect as in the case of using the film-forming auxiliary can be obtained, and the present invention has been completed. .

That is, the room temperature curable emulsion of the present invention comprises a silyl group-containing vinyl monomer represented by the following general formula (I) (hereinafter, also referred to as "silyl group-containing vinyl monomer"). , Another copolymerizable vinyl-based monomer is emulsion-polymerized in the presence of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.

[0008]

[Chemical 3] (In the formula, R is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, X
Is a group selected from a halogen atom, an alkoxy group, a hydroxy group, an acyloxy group, an aminoxy group, a phenoxy group, a thioalkoxy group and an amino group, y is an integer of 0 to 2,
When each of X and R bonded to Si is 2 or more,
They may be the same or different groups. ).

Further, the method for producing a room temperature curable emulsion of the present invention comprises: a silyl group-containing vinyl monomer represented by the above general formula (I); and another copolymerizable vinyl monomer. This is a method characterized by emulsion polymerization in the presence of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate.

Silyl Group-Containing Vinyl Monomer The vinyl monomer having a silyl group represented by the general formula (I) is not limited, but specific examples include:

[Chemical 4]

[0011]

[Chemical 5]

[0012]

[Chemical 6] Etc.

Particularly, it is preferable to use an alkoxysilyl group-containing compound from the viewpoints of easy handling, cost and reaction by-product.

These silyl group-containing vinyl monomers may be used alone or in combination of two or more.

Copolymerizable with vinyl monomer containing silyl group
Other vinyl-based monomers are not limited to other vinyl-based monomers copolymerizable with the silyl group-containing vinyl-based monomer, and include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth). )
(Meth) acrylate monomers such as acrylate, isobutyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate; trifluoroethyl (meth) acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl ( Fluorine-containing vinyl monomers such as (meth) acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, β- (perfluorooctyl) ethyl (meth) acrylate; styrene, α-methylstyrene, chlorostyrene, 4 -Aromatic hydrocarbon vinyl monomers such as hydroxystyrene and vinyltoluene; acrylic acid,
Polymerizable α, β-ethylenically unsaturated carboxylic acids such as methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, crotonic acid, fumaric acid, citraconic acid, styrene sulfonic acid, vinyl sulfonic acid, etc. Acids having a carbon-carbon double bond, or salts thereof (alkali metal salts, ammonium salts, amine salts, etc.); acid anhydrides such as maleic anhydride, or those and C 1-2
Half-esters with 0 straight or branched alcohols;
An amino group-containing (meth) acrylate such as dimethylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, diethylaminoethyl (meth) acrylate; (meth) acrylamide, α-
Ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethylacrylamide, N-methylacrylamide, acryloylmorpholine or their hydrochloric acid, acetate; vinyl acetate, vinyl propionate, vinyl such as diallyl phthalate Ester and allyl compounds; Vinyl monomers containing nitrile groups such as (meth) acrylonitrile; Glycidyl (meth)
Epoxy group-containing vinyl monomer such as acrylate; 2
-Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N-methylol (meth) acrylamide, hydroxystyrene, Aronix 5700 (manufactured by Toagosei Kagaku Co., Ltd.), PlaccelFA-1, Pl
accelFA-4, PlaccelFM-1, Pla
ccelFM-4 (above, manufactured by Daicel Chemical Industries, Ltd.), H
E-10, HE-20, HP-10, HP-20 (all manufactured by Nippon Shokubai Kagaku Co., Ltd.), Blemmer PP series, Blemmer PE series, Blemmer PEP series, Blemmer AP-400, Blemmer AE-35.
0, Bremmer NKH-5050, Bremmer GLM
(Above, manufactured by NOF CORPORATION), hydroxyl-containing vinyl-based monomers such as hydroxyl-containing vinyl-modified hydroxyalkylvinyl-based monomers; α, β-ethylenic monomers such as hydroxyalkyl esters of (meth) acrylic acid Vinyl compounds such as condensation products of hydroxyalkyl esters of saturated carboxylic acids and phosphoric acid or phosphoric acid esters, or vinyl compounds such as (meth) acrylates containing urethane bond or siloxane bond; Toa Synthetic Chemical Co., Ltd. macro AS-6, AN-6, AA-6, which are monomers
Compounds such as AB-6 and AK-5, vinyl vinyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, N-vinyl imidazole, other vinyl monomers such as vinyl sulfonic acid, Asahi Denka Kogyo Co., Ltd. Polymerization type light stabilizers such as LA87, LA82, LA22, etc., polymerization type ultraviolet absorbers, and the like.

By using the fluorine-containing vinyl-based monomer and the siloxane-containing vinyl-based monomer, water repellency is improved, and water resistance and durability are improved. In addition, (meth) acrylic acid, maleic acid, dimethylaminoethyl (meth) acrylate, (meth) acrylamide, vinyl monomers containing hydroxyl groups or hydrophilic monomers such as polypropylene glycol methacrylate and polyethylene glycol monomethacrylate are used. Then, the stability of the emulsion is improved.

In addition to this, by using a monomer having two or more polymerizable unsaturated bonds such as polyethylene glycol dimethacrylate, ethylene glycol diacrylate, triallyl cyanurate, the resulting polymer is crosslinked. It is also possible to have a structure.

2,2,4-trimethyl-1,3-penta
In the case of emulsion-polymerizing vinyl diol monoisobutyrate silyl group-containing vinyl monomer and vinyl monomer polymerizable therewith, 2,2,4-trimethyl-1,3-pentanediol monoisobuty By adding a rate (see the following structural formulas [Chemical formula 7] and [Chemical formula 8]), the film-forming aid which has been required up to now can be omitted, and the generation of aggregates and the "bugs" in the coating film can be eliminated. The problem of the generation of so-called fine protrusions is solved. Not only that, the same effect as when the film-forming aid is used can be obtained.

[0019]

[Chemical 7]

[0020]

[Chemical 8]

The proportion of 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate used is preferably 1 to 50% (% by weight, the same applies hereinafter) with respect to the total amount of the monomers. -20% is more preferable.

As the method of use, it may be emulsified in water as an initial charge or used in a dropping monomer emulsion, but it is preferable to use it in a dropping monomer emulsion from the viewpoint of polymerization stability.

The silyl group-containing vinyl-based monomer and the other vinyl-based monomer copolymerizable with the silyl group-containing vinyl monomer are used in proportion to the total amount of the silyl group-containing vinyl-based monomer. It is preferably 0.5 to 30%, and 2 to 20%
Is more preferable. When the ratio of the silyl group-containing vinyl-based monomer is less than 0.5%, the water resistance and weather resistance tend to be poor, and when it exceeds 30%, the stability of the emulsion tends to decrease. Next, production of an emulsion polymer obtained by emulsion-polymerizing the above-mentioned silyl group-containing vinyl-based monomer and another vinyl-based monomer copolymerizable therewith will be described.

As the emulsion polymerization method, various emulsion polymerization methods such as a batch polymerization method, a monomer dropping polymerization method, and an emulsion monomer dropping polymerization method can be appropriately selected and adopted, and in particular, stability during production is ensured. For this purpose, the monomer dropping polymerization method and the emulsion monomer dropping polymerization method are suitable.

The surfactant that can be used in the above production method is not particularly limited, and examples of the ionic surfactant include sodium lauryl sulfonate, sodium dodecylbenzene sulfonate, sodium isooctylbenzene sulfonate, and the like. As the ionic surfactant, polyoxyethylenes such as polyoxyethylene nonylphenyl ether and polyoxyethylene lauryl ether; L-77, L-720, L-5410, L-760
2, representative examples include nonionic surfactants containing silicon such as L-7607 (above, manufactured by Union Carbide Co., Ltd.). The use of a reactive surfactant having a polymerizable double bond in one molecule as the surfactant does not hinder the present invention. In particular, when a reactive activator having a polyoxyethylene group in the molecule is used, water resistance is improved. As a specific example, ADEKA SOAP NE-10, NE
-20, NE-30, NE-40, SE-10N (all manufactured by Asahi Denka Co., Ltd.), Antox-MS-60
(Nippon Emulsifier Co., Ltd.), Aqualon RN-20, RN
-30, RN-50, HS-10, HS-20, HS-
1025 (above, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.).

It is also possible to polymerize by using a water-soluble resin in combination. Using this method has an advantage that the water resistance of the coating film is improved. By introducing the silyl group represented by the general formula (I) into the water-soluble resin, the water resistance can be further enhanced.

Further, a redox catalyst (polymerization initiator)
If the polymerization is carried out at a temperature of 70 ° C. or lower, preferably 40 to 65 ° C., the polymerization can be carried out more stably.

Examples of the redox catalysts include inorganic peroxides such as potassium persulfate, ammonium persulfate and hydrogen peroxide, and t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, p.
-A peroxide such as menthane hydroperoxide and a reducing substance such as acidic sodium sulfite, rongalite, and ascorbic acid are used in combination. In particular, a combination of an organic peroxide and a reducing agent is preferable from the viewpoint of stable polymerization. Further, a compound containing a divalent iron ion such as iron sulfate and a chelating agent such as disodium ethylenediaminetetraacetate may be appropriately used in combination in order to stably obtain the catalytic activity.

The proportion of such a polymerization initiator used is preferably 0.01 to 10%, more preferably 0.05 to 5%, based on the total weight of the monomers.

The solid content concentration in the emulsion of the present invention is preferably 20 to 70%, and 30 to 60%.
Is more preferable.

When the solid content concentration exceeds 70%, the viscosity of the system remarkably increases, so that it is difficult to remove heat generated by the polymerization reaction, and it takes a long time to take it out from the polymerization machine. Cause Further, when the solid content concentration is less than 20%, no problem occurs in terms of polymerization operation, but the amount of resin produced by one polymerization operation is small, which is extremely disadvantageous from the economical point of view. If the concentration is less than 20%, the thickness of the coating film becomes thin, resulting in performance problems and disadvantages in coating workability.

The emulsion contains ultrafine particles having an average particle diameter of about 0.02 to 0.7 μm, and as a result, has excellent film forming ability.

The curing agent may or may not be used, but crosslinking is promoted by adding the cured product at the time of coating. As a curing agent, an organometallic compound, an acid catalyst,
A basic catalyst is used. In particular, organic metal compounds are preferable.

The organometallic compound used as the curing agent is not particularly limited, and specific examples thereof include dibutyltin dilaurate, dibutyltin dimaleate, dioctyltin dilaurate, dioctyltin dimaleate, dibutyltin diacetate, dibutyltin dimethoxide, tributyltin. Organotin compounds such as sulfite, dibutyltin thioglycolate and tin octylate; Organoaluminum compounds such as aluminum isopropylate, aluminum tris (ethylacetoacetate), aluminum tris (acetylacetonate), ethylacetoacetate aluminum diisopropylate; Isopropyl tristearoyl titanate, tetraisopropyl bis (dioctyl phosphite) titanate, bis (dioctyl pyrophosphate) ) Organic titanium compounds such as oxyacetate titanate; tetra -n- butoxy zirconium, zirconyl octylate, organic zirconium compound in the reaction products of alkoxy zirconium acetylacetone or acetoacetic ester.

In particular, organotin compounds and organoaluminum compounds are excellent in curing activity. These organometallic compounds are excellent in curing activity and storage stability when they are emulsified in advance and added at the time of use. The amount of the organic metal compound used is 0.01 to 10 relative to 100 parts by weight of the solid content of the silyl group-containing emulsion (hereinafter, simply referred to as “part”).
It is preferable to add 1 part by weight, more preferably 0.1 to 5 parts by weight. If it is less than 0.01 part, the curing activity is low, and if it exceeds 10 parts, the water resistance is lowered.

In the obtained curable emulsion, as an additive, a pigment (white pigment such as titanium dioxide, calcium carbonate, barium carbonate, kaolin, etc.) which is usually used in a paint, a colored system such as carbon, red iron oxide, cyanine blue, etc. is added. Pigment), film-forming agent, colloidal silica, plasticizer, solvent,
It is also possible to use a mixture of additives such as a dispersant, a thickener, a defoaming agent, an antiseptic, an ultraviolet absorber and the like, which are usually used for coating compositions.

It is also possible to blend with a commercially available water-based paint, for example, an acrylic paint,
Thermosetting acrylic paint, such as acrylic melamine paint
It is possible to blend with an alkyd paint, an epoxy paint, and a fluororesin paint, and when blended, the weather resistance, acid resistance, and solvent resistance of these paints can be improved.

It is also possible to add a melamine resin or an isocyanate compound as a cross-linking agent to obtain a fast curing property.

The obtained composition is used, for example, for interior and exterior construction,
For repair, for automobiles such as clear on metallic coat,
For direct coating of metals such as aluminum and stainless steel, slate,
It is used as a paint for ceramics such as concrete and roof tiles, as a paint for glass and stone, or as a top treatment agent. Also,
It can also be used as an adhesive or an adhesive.

[0040]

EFFECTS OF THE INVENTION According to the present invention, the film-forming aid, which has been necessary up to now, can be omitted, resulting in the generation of agglomerates and the protrusions called "bugs" formed on the cured product (coating film). The problem of occurrence of the above can be solved, and moreover, an effect equivalent to that in the case of using the film-forming auxiliary can be obtained.

[0041]

EXAMPLES The present invention will be described below based on examples, but the present invention is not limited thereto.

Examples 1 and 2 and Comparative Examples 1 to 3 A reactor equipped with a stirrer, a reflux condenser, a nitrogen gas introducing pipe and a dropping funnel was initially charged with deionized water 40.
Parts, Rongalit 0.35 parts, ammonium acetate 0.5
Parts, 0.2 parts of t-butyl hydroperoxide, and an initial charged monomer emulsion having the composition shown in [Table 1] below were used for initial polymerization.

Then, while introducing nitrogen gas, the temperature was raised to 50 ° C., and after heating for 1 hour, 0.5 part of t-butyl hydroperoxide and a dropping monomer emulsion having the composition shown in [Table 1] were added. The mixture was added dropwise over 3 hours.

Polymerization was carried out for 1 hour after the completion of dropping, and deionized water was used to adjust the solid content concentration to 40% to obtain the desired emulsion.

The polymerization state (), the coating film forming performance () using the obtained emulsion as a coating material, and the appearance property () of the formed coating film were evaluated as follows. The results are shown in [Table 2].

Polymerization state It was evaluated by the amount of scale (aggregate) generated during polymerization . That is, after the completion of the polymerization, those with a large scale amount were marked with X, and those with a small amount were marked with O.

Film Forming Performance The film forming property at 5 ° C. was visually evaluated. That is, 5 ° C
When an emulsion (previously filtered through a 200-mesh wire mesh) was applied on a glass plate under the conditions of No., the formed coating film showed no abnormality, and the one in which cracks were observed was marked as X. .

Appearance The appearance of the coating film was also visually evaluated. That is, when an emulsion (previously filtered with a 200-mesh wire net) was applied to a glass plate under the condition of 23 ° C., a film having no abnormality in the formed coating film was ◯, and generation of spots was observed. Was designated as x.

[0049]

[Table 1]

[0050]

[Table 2]

Claims (3)

[Claims] 1. A vinyl monomer having a silyl group represented by the following general formula (I) and another copolymerizable vinyl monomer are added to 2,2,4-trimethyl-1,3. -A room temperature curable emulsion obtained by emulsion polymerization in the presence of pentanediol monoisobutyrate. [Chemical 1] (In the formula, R is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, X
Is a group selected from a halogen atom, an alkoxy group, a hydroxy group, an acyloxy group, an aminoxy group, a phenoxy group, a thioalkoxy group and an amino group, y is an integer of 0 to 2,
When each of X and R bonded to Si is 2 or more,
They may be the same or different groups. ) 2. The room temperature curable emulsion according to claim 1, wherein the silyl group is an alkoxysilyl group. 3. A vinyl monomer having a silyl group represented by the following general formula (I) and another copolymerizable vinyl monomer are added to 2,2,4-trimethyl-1, A method for producing a room temperature curable emulsion, which comprises emulsion-polymerizing in the presence of 3-pentanediol monoisobutyrate. [Chemical 2] (In the formula, R is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, X
Is a group selected from a halogen atom, an alkoxy group, a hydroxy group, an acyloxy group, an aminoxy group, a phenoxy group, a thioalkoxy group and an amino group, y is an integer of 0 to 2,
When each of X and R bonded to Si is 2 or more,
They may be the same or different groups. )