JPH06299000A - Heat-sensitive gelling copolymer latex - Google Patents

Abstract

(57) [Abstract] [Purpose] A heat-sensitive gelling property that can form a coating layer having good adhesion to a substrate without causing cracks or blisters in the coating layer formed after drying treatment. Providing a copolymer latex. [Structure] Monomer component (a) [aliphatic conjugated diene monomer and / or (meth) acrylic acid alkyl ester monomer] 1 to 99.9% by weight, monomer component (b) [functional Group-containing monomer] 0.1 to 20% by weight and monomer component (c) [monomer copolymerizable with monomer component (a) and monomer component (b)] 0 A glass transition point of +30 to -70 obtained by emulsion polymerization of 100 parts by weight of a monomer mixture consisting of 98.9% by weight in the presence of 0.1 to 20 parts by weight of an ethylenically unsaturated surfactant. It is characterized in that the copolymer latex at ℃ contains a heat-sensitive gelling agent.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a heat-sensitive gelling copolymer latex, more specifically, rubber-immersed products such as gloves and tubes, backing materials for carpets, binders for non-woven fabrics, binders for paper processing, and plywood. Suitable for use as adhesives, interior and exterior paints for civil engineering and construction products, electrical products, office machines, etc., automotive exterior paints, automotive chipping resistant paints, and other protective coating materials, adhesives and paints The present invention relates to a heat-sensitive gelling copolymer latex that can be used.

[0002]

2. Description of the Related Art For example, in a backing material for carpets, a binder for non-woven fabrics, and an adhesive for plywood, from the viewpoint of improving durability, a styrene-butadiene latex or vinyl acetate-based latex dispersed in an aqueous system with an anionic surfactant. BACKGROUND ART Latex and backing materials containing vinyl chloride-based latex as a main component and adhesives are known.

In addition, automobiles, civil engineering and construction products, electric products,
In various base materials used as interior and exterior materials for office machines (eg plastic base materials, rubber base materials, metal base materials, ceramic base materials, cement base materials, etc.)
Paints, coating materials, and adhesives containing acrylic latex, styrene-acrylic latex, silicone latex, and the like as main components are used to protect these surfaces and fix them between base materials.

These latex materials are applied to a base material and then dried at a high temperature, whereby a coating film / coating layer / adhesive layer (hereinafter simply referred to as “coating layer”) is formed on the surface of the base material. Is formed.

[0005]

However, in the above latex material, blisters and cracks may occur in the coating layer formed through the drying treatment. In recent years, there has been a tendency to increase the drying temperature in order to increase productivity, and blister and cracks are particularly likely to occur in the coating layer.

Blisters and cracks in the coating layer lead to a decrease in adhesion to the base material and a decrease in water resistance and weather resistance. Depending on the coating layer having such defects, the protection performance of the base material and the inter-base material Adhesive performance cannot be fully exhibited.

The present invention has been made under the circumstances described above, and an object of the present invention is to prevent cracks and blisters from being generated in a coating layer formed through a drying treatment and to be applied to a substrate. It is to provide a heat-sensitive gelling copolymer latex capable of forming a coating layer having good adhesion.

[0008]

The heat-sensitive gelling copolymer latex of the present invention comprises the following monomer components (a) 1 to 99.
100 parts by weight of a monomer mixture consisting of 9% by weight, 0.1 to 20% by weight of the following monomer component (b) and 0 to 98.9% by weight of the following monomer component (c) was added to an ethylenic mixture. A latex of a copolymer having a glass transition point of +30 to −70 ° C., which is obtained by emulsion polymerization in the presence of 0.1 to 20 parts by weight of a saturated surfactant, contains a heat-sensitive gelling agent. Characterize. Monomer component (a): Aliphatic conjugated diene monomer and /
Or (meth) acrylic acid alkyl ester monomer. Monomer component (b): a monomer having a functional group. Monomer component (c): A monomer copolymerizable with the monomer component (a) and the monomer component (b).

[0009]

According to the heat-sensitive gelling copolymer latex of the present invention, as is clear from the results of Examples described later, cracks and blisters are not generated in the coating layer formed after the drying treatment, and further, The coating layer has excellent adhesion to the base material. Although the reason why such an excellent effect is exerted is not clear, the composition containing the heat-sensitive gelling agent (heat-sensitive gelling copolymer latex of the present invention) has a predetermined heat-sensitive gelling temperature. (For example, 60 to 100
However, when the heat-sensitive gelling temperature is reached, the surface charge of the latex particles is significantly reduced by the heat-sensitive gelling agent and the latex state becomes unstable. Thickens and gels in time. Therefore, under the drying temperature (for example, 80 to 15
At 0 ° C., migration and volume shrinkage are suppressed due to thickening and gelation of the composition, whereby a uniform coating layer having excellent adhesion to a substrate and free from blisters and cracks is formed. It is estimated that

The present invention will be described in detail below. The heat-sensitive gelling copolymer latex of the present invention is a copolymer latex obtained by emulsion-polymerizing a monomer mixture having a specific composition in the presence of an ethylenically unsaturated surfactant, and the heat-sensitive gelling agent is It is contained.

<Monomer Mixture> The monomer mixture used in the present invention is a monomer component (a) comprising an aliphatic conjugated diene monomer and / or a (meth) acrylic acid alkyl ester monomer. [Hereinafter referred to as "component (a)"], a monomer component (b) composed of a monomer having a functional group [hereinafter referred to as "component (b)"], the component (a) and the component (b). The component and a monomer component (c) composed of a monomer capable of copolymerization [hereinafter referred to as "component (c)"].

Component (a) The aliphatic conjugated diene-based monomer which is the component (a) constituting the monomer mixture includes 1,3-butadiene, isoprene, 2-chloro-1,3-butadiene, and -Methyl-
1,3-Butadiene and the like can be mentioned, and these monomers can be used alone or in admixture of two or more kinds. Of these, 1,3-butadiene is preferable.

As the (meth) acrylic acid alkyl ester monomer which is the component (a), there are methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, and (meth) acrylic acid. n-butyl, i-butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, heptyl (meth) acrylate, n-amyl (meth) acrylate, i-methacrylate acrylate Amyl, 2-methylhexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, i-nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate , N-octyl (meth) acrylate, lauryl (meth) acrylate, benzyl (meth) acrylate, and (meth) acrylate Such Rohekishiru, preferably (meth) acrylic acid n- butyl, (meth) acrylic acid 2-ethylhexyl can be mentioned, these monomers may be mixed alone, or two or more types (a)
You may comprise the component.

Of these, the number of carbon atoms in the alkyl group is 1 to
4 (meth) acrylic acid alkyl ester is preferable,
Particularly preferably, methyl methacrylate and acrylic acid n-
Butyl.

The content of the component (a) in the monomer mixture is usually 1 to 99.9% by weight, preferably 3 to 96% by weight. When the content ratio of the component (a) is less than 1% by weight, the film forming property is deteriorated, and the coating layer formed is inferior in adhesiveness to a substrate and water resistance. On the other hand, if this proportion exceeds 99.9% by weight, the coating layer formed will not have sufficient strength.

Component (b) The component (b) constituting the monomer mixture is a monomer having a functional group such as a carboxyl group, an acid anhydride group, a hydroxyl group, an amide group, an amino group and a glycidyl group. Specific examples of the component (b) include itaconic acid, (meth) acrylic acid,
Carboxyl group-containing monomers such as ethylenically unsaturated (di) carboxylic acids such as fumaric acid, maleic acid and crotonic acid; acid anhydride groups such as acid anhydrides of ethylenically unsaturated dicarboxylic acids such as fumaric acid and maleic acid Contained monomer; (meth)
Hydroxyl acrylate, hydroxyethyl (meth) acrylate, β-hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate, and other hydroxyl group-containing monomers such as ethylenically unsaturated carboxylic acid hydroxyalkyl ester; ) Amide group-containing monomers such as acrylamide, N-methylol (meth) acrylamide, diacetone acrylamide, ethacrylamide, crotonamide, itaconamide, methylitaconamide, maleic acid monoamide, and ethylenically unsaturated carboxylic acid alkylamides; ) Aminoethyl acrylate,
Amino group-containing monomers such as dimethylaminoethyl (meth) acrylate, β-aminoethyl vinyl ether, and dimethylaminoethyl vinyl ether; ethylenically unsaturated carboxylic acids such as aminoethylacrylamide, dimethylaminomethylmethacrylamide, and methylaminopropylmethacrylamide Monomers containing amino groups and amide groups such as aminoalkylamides; glycidyl group-containing monomers such as glycidyl esters of ethylenically unsaturated carboxylic acids such as glycidyl (meth) acrylate, and the like. These monomers may be used alone or in combination of two or more to form the component (b). Of these, a carboxyl group-containing monomer is preferable.

The content of the component (b) in the monomer mixture is usually 0.1 to 20% by weight, preferably 0.3 to 10% by weight. When the content ratio of the component (b) is less than 0.1% by weight, the coating film formed does not have sufficient strength, and good weather resistance cannot be exhibited. On the other hand, this proportion is 20% by weight
If it exceeds, the heat-sensitive gelling property is difficult to be exhibited, and cracks are generated during the drying treatment.

Component (c) Specific examples of the component (c) constituting the monomer mixture include:
Styrene, α-methylstyrene, p-methylstyrene,
Aromatic vinyl compounds such as vinyltoluene, vinyl acetate, carboxylic acid vinyl esters such as vinyl propionate, (meth) acrylonitrile, vinyl cyanide such as α-chloroacrylonitrile, vinyl chloride, and the like. The body may be a single component or a mixture of two or more components to form the component (c). Of these, aromatic vinyl compounds and vinyl cyanide compounds are preferable, and styrene and acrylonitrile are particularly preferable.

The content ratio of the component (c) in the monomer mixture is usually 0 to 98.9% by weight, preferably 10 to 95% by weight. When the content ratio of the component (c) exceeds 98.9% by weight, the hardness of the coating film formed becomes excessive and becomes brittle, which leads to deterioration in cold and flex resistance and also in repeated environment of cold heat. , The adhesiveness to the substrate is significantly reduced.

As described above, the effect of preventing the generation of blisters and cracks in the coating layer, the coating layer and the base material are not determined until the type and content ratio of each monomer component constituting the monomer mixture are specified. The effect of improving the adhesion between the two is exhibited.

<Ethylene Unsaturated Surfactant> The above-mentioned monomer mixture is subjected to emulsion polymerization in the presence of an ethylenically unsaturated surfactant, whereby the copolymer latex constituting the present invention is obtained. It is formed.

Here, the ethylenically unsaturated surfactant is
It is a surfactant having a polymerizable reactive group such as a vinyl group, an acryloyl group and a methacryloyl group and capable of forming latex particles having an average particle size of 250 nm or less. Compounds particularly suitable as such an ethylenically unsaturated surfactant are shown in Chemical Formulas 1 to 5 below.

[0023]

[Chemical 1]

(In the formula ¹ , R ¹ represents an alkylene group having 2 to 4 carbon atoms, R ² represents a hydrocarbon group which may have a substituent, a phenyl group, an amino group or a carboxyl group; ³ is a hydrogen atom or a methyl group, M is Na
Or NH ₄ is shown. p is an integer of 0-50. )

[0025]

[Chemical 2]

(In chemical formula 2, R ¹ , R ² , R ³ , M and p
Are respectively the same as in Chemical formula 1. )

[0027]

[Chemical 3]

(In Chemical Formula 3, R ¹ and R ³ are the same as those in Chemical Formula 1, R ⁴ represents a hydrocarbon group which may have a substituent, and X represents a hydrogen atom or a nonionic hydrophilic group. Represents a group or an anionic hydrophilic group, and m is an integer of 0 to 100.)

[0029]

[Chemical 4]

(In the formula 4, R ⁵ represents an alkyl group, an alkenyl group or an aralkyl group having 4 to 18 carbon atoms, and R ⁶
Represents a hydrogen atom or an alkyl group, an alkenyl group or an aralkyl group having 4 to 18 carbon atoms, R ⁷ represents a hydrogen atom or a methyl group, and Y represents “—O— (R ⁸ O) _q—
H "or" _{^{-O- (R 8 O) q SO}} 3 Q "(R ⁸ is an alkylene group or substituted alkylene group having 2 to 4 carbon atoms, Q
Represents an alkali metal atom, NH ₄ or an alkanolamine residue, q is an integer of 2 to 200), and n is an integer of 0 to 10. )

[0031]

[Chemical 5]

(Wherein R ¹ , R ² , R ³ and p are
Each is the same as in Chemical formula 1, Z is an alkali metal atom,
Indicates NH ₄ or alkanolamine residue. )

The ethylenically unsaturated surfactant having the structure represented by the above Chemical Formulas 1 to 5 is preferably anionic. Among the ethylenically unsaturated surfactants having the structures represented by Chemical Formulas 1 to 5, those having the structure represented by Chemical Formula 3 are preferable.

The emulsion polymerization of the monomer mixture is finally carried out in the presence of an ethylenically unsaturated surfactant, as compared with the case where the emulsion polymerization is carried out in the presence of a usual surfactant. The heat-sensitive gelling property of the heat-sensitive gelling copolymer latex is remarkably increased, and a coating layer excellent in adhesion and water resistance can be formed.

The amount of the ethylenically unsaturated surfactant used in the emulsion polymerization is 0.1 to 20 parts by weight based on 100 parts by weight of the monomer mixture. This usage is 0.
When the amount is less than 1 part by weight, the polymerization stability is poor, and the copolymer latex constituting the present invention cannot be suitably obtained. On the other hand, when the amount used exceeds 20 parts by weight, the latex state of the composition is stably maintained even when the composition finally obtained is heat-sensitive to the heat-sensitive gelling temperature, which is favorable. The thermosensitive gelling property cannot be exhibited.

In emulsion polymerization of the monomer mixture, various surfactants (anionic surfactants, nonionic surfactants, cationic surfactants) other than the above ethylenically unsaturated surfactants are used. You may use together.

<Polymerization Initiator / Chain Transfer Agent> In emulsion polymerization of the monomer mixture, known polymerization initiators and chain transfer agents are used. Here, as the polymerization initiator, for example, hydroperoxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, and paramenthane hydroperoxide, peroxides such as benzoyl peroxide and lauroyl peroxide, and azobisisobutyrate. Examples thereof include organic polymerization initiators represented by azo compounds such as ronitrile; and inorganic polymerization initiators represented by persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate. The amount of the polymerization initiator to be used is usually 0.03 to 2% by weight, preferably 0.0
It is set to 5 to 1% by weight.

In order to accelerate the emulsion polymerization, reducing agents such as sodium pyrobisulfite, sodium sulfite, sodium hydrogen sulfite, ferrous sulfate, glucose, sodium formaldehyde sulfoxylate, L-ascorbic acid and salts thereof; A chelating agent such as glycine, alanine, and sodium ethylenediaminetetraacetate can also be used in combination.

As the chain transfer agent, α-methylstyrene dimer, preferably 2-4-diphenyl-4-
Α-methylstyrene dimer containing 60% by weight or more of methyl-1-pentene component, terpinolene, α-terpinene, γ-terpinene, dipentene, octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, n-hexadecyl mercaptan, thio. Examples include octyl glycolate, diethylxanthogen disulfide, dimethylxanthogen disulfide, dimethylxanthogen disulfide, diisopropylxanthogen disulfide, tetramethylthiuram monosulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, dipentamethylenethiuram disulfide, and the like. Alternatively, two or more kinds may be used in combination. The amount of the chain transfer agent used is usually 0 to 15% by weight based on the monomer mixture.

<Glass Transition Point of Copolymer Component> The glass transition point (Tg) of the copolymer component [referring to the copolymer (solid content) constituting the latex] obtained by emulsion polymerization of the monomer mixture is , + 30 ° C to -70 ° C, preferably +20 to -50 ° C. When the glass transition point (Tg) of the copolymer component exceeds + 30 ° C. and becomes high, the film-forming property of the finally obtained heat-sensitive gelling copolymer latex is poor, and the coating layer formed is It has low adhesion to the substrate. On the other hand, the glass transition point (T
When g) is lower than -70 ° C, the heat-sensitive gelling copolymer latex finally obtained exhibits tackiness, resulting in poor stain resistance and rigidity.

Here, the "glass transition point (Tg)" in the present invention means a film obtained by applying about 5 g of the copolymer latex on a glass plate so as to stretch it thinly and drying at 25 ° C. for 7 days. The value of the sample is measured by a differential scanning calorimeter (DSC) [manufactured by Rigaku Denki Co., Ltd.]. The measurement conditions are:
Temperature rising temperature: 20 ° C / min, atmosphere gas: nitrogen gas,
Sample amount: 20 mg.

<Heat-sensitive gelling agent> The heat-sensitive gelling copolymer latex of the present invention is obtained by adding a heat-sensitive gelling agent to the copolymer latex obtained by emulsion polymerization of a monomer mixture. is there.

The "heat-sensitive gelling agent" changes its structural function at a predetermined heat-sensitive temperature and changes the properties of the copolymer latex containing the same (thickening / gelling). .

Specific examples of the heat-sensitive gelling agent include alkylene oxide adducts of alkylphenol formalin condensates, polyether formal, polyvinyl methyl ether, polypropylene glycol, polyalkylene oxide-modified polysiloxane, water-soluble polyamide, starch,
Examples thereof include methyl cellulose, hydroxyethyl cellulose, carboxymethyl cellulose, protein, carbonate, bicarbonate, polyphosphate, and nonionic surfactant having a cloud point. These may be used alone or in admixture of two or more. You can Of these, alkylene oxide adducts of alkylphenol formalin condensates (especially those having a cloud point of 40 ° C. or higher) and polyalkylene oxide-modified polysiloxanes are preferable.

The content ratio of the heat-sensitive gelling agent in the heat-sensitive gelling copolymer latex of the present invention is 0.01 to 30 parts by weight based on 100 parts by weight of the copolymer component (solid content of the copolymer latex). It is preferably part. If this proportion is less than 0.01 part by weight, blisters in the coating layer
It becomes difficult to exhibit the effect of preventing the occurrence of cracks and the effect of improving the adhesion between the coating layer and the base material. On the other hand, if this ratio exceeds 30 parts by weight, the stability of the latex state is impaired, and gelation or coagulation may occur at a stage where the temperature does not reach the heat-sensitive temperature.

The content range of the heat-sensitive gelling agent has a different preferable range depending on the kind of the heat-sensitive gelling agent and the kind of the copolymer latex. The preferable content ratios of the individual heat-sensitive gelling agents are shown below (the numerical values are "parts by weight per 100 parts by weight of the copolymer component").

Alkylene oxide adduct of alkylphenol formalin condensate, and polyalkylene oxide-modified polysiloxane ... 0.01 to 5 polyether polyformal and polyvinyl methyl ether ... 0.5 to 7 polypropylene glycol ... 0.2 to 5 water-soluble Polyamide ... 1-10 Starch ... 5-30 Protein ... 5-30 Methylcellulose, hydroxyethylcellulose and carboxymethylcellulose ... 0.2-10 Carbonate and bicarbonate ... 0.1-3.0 Polyphosphate ... 0.5- 3.0 Nonionic surfactant having a cloud point of 50 ° C. or lower ...
1 to 3.0

<Heat-Sensitive Aid> The heat-sensitive gelling copolymer latex of the present invention is constituted by containing a heat-sensitive gelling agent in the copolymer latex. The agent may be contained. Here, the heat-sensitive auxiliary agent is a compound that changes the heat-sensitive temperature and viscosity increase of the latex composition, and by containing this heat-sensitive auxiliary agent, the heat-sensitive gelling property of the heat-sensitive gelling copolymer latex Can be further improved (thickening / promotion of gelation). Specific examples of the heat-sensitive assistant include ammonia, boric acid,
Examples include zinc white, urea, salts of polyvalent metals, double salts, complex salts and the like. The content ratio of the heat-sensitive assistant is preferably 0.02 to 10 parts by weight, and more preferably 0.1 to 8 parts by weight with respect to 100 parts by weight of the copolymer component.

<Additives> The heat-sensitive gelling copolymer latex of the present invention contains the copolymer latex and the heat-sensitive gelling agent as essential components, but other additives may be added as necessary. May be contained. As additives, fillers such as clay, kaolin, talc, calcium carbonate, diatomaceous earth, graphite, alumina, iron oxide, titanium oxide, silica, rubber powder, glass flakes, bentonite, aluminum hydroxide; epoxy resin, melamine resin, Cross-linking agents such as blocked isocyanate; dispersants such as sodium tripolyphosphate and potassium pyrophosphate; other,
Thickener, anti-aging agent, UV absorber, colorant, preservative,
Examples thereof include antifoaming agents. Further, by adding a nonionic surfactant having a cloud point of about 60 ° C. to the heat-sensitive gelling copolymer latex of the present invention, the storage stability thereof can be further enhanced. Here, the amount of the nonionic surfactant added is the copolymer latex 10
The amount is about 0.2 to 1.5 parts by weight with respect to 0 parts by weight (solid content).

[0050]

EXAMPLES Examples of the present invention will be described below, but the present invention is not limited thereto. In the following, "parts" and "%" indicate "parts by weight" and "% by weight", respectively.

<Example of Preparation of Copolymer Latex> Copolymer Latex AE 100 parts of each monomer mixture having the composition shown in Table 1 below, and an ethylenically unsaturated surfactant represented by the following chemical formula 6 ADEKA S
E10N "(manufactured by Asahi Denka Co., Ltd.), 2.5 parts of potassium persulfate (polymerization initiator), 0.2 part of dodecyl mercaptan (molecular weight modifier), and sodium ethylenediaminetetraacetate (chelating agent). 0.03 parts and 180 parts of water were charged into a stainless steel autoclave having an internal volume of 100 liters which was replaced with nitrogen gas, and emulsion polymerization was carried out at a temperature of 55 to 80 ° C. for 20 hours while stirring to obtain a Polymer latexes A to E (for the present invention) were prepared. Table 1 also shows the polymerization conversion rate and glass transition point (Tg) of these copolymer latexes.

[0052]

[Chemical 6]

Copolymer Latex FI I Copolymer Latex FI (Comparative) except that each monomer mixture having the composition shown in Table 1 below was used. ) Was prepared. The polymerization conversion rate and glass transition point (T
g) is also shown in Table 1. Here, the copolymer latex F had no component (b) in the monomer mixture, and the copolymer latex G had an excessively large proportion of the component (b) in the monomer mixture. The copolymer latex H has a too high glass transition point (Tg),
The copolymer latex I has a too low glass transition point (Tg).

Copolymer Latex J Using a monomer mixture having the composition shown in Table 1 below, instead of the ethylenically unsaturated surfactant, a hydrocarbon surfactant "Emar 10 Needle" (manufactured by Kao Corporation, structure Formula: C ₁₂ H ₂₅ O
SO ₃ Na) except that 2.5 parts of copolymer latex A was used, and copolymer latex J was prepared in the same manner as in the preparation example of copolymer latex A.
(For comparison) was prepared. The polymerization conversion rate of this copolymer latex J was 99.8%, and the glass transition point (Tg) was −30 ° C.

Copolymer Latex K of Copolymer Latex A except that the monomer mixture having the composition shown in Table 1 below was used and the amount of the ethylenically unsaturated surfactant used was changed to 23.5 parts. A copolymer latex K (for comparison) was prepared in the same manner as in Preparation Example. The polymerization conversion rate of this copolymer latex K was 99.8%, and the glass transition point (Tg) was -23 ° C.

[0056]

[Table 1]

<Examples 1 to 5 and Comparative Examples 1 to 7> According to the formulation shown in Table 2 below, a heat-sensitive gelling agent was added to 100 parts (solid content) of the copolymer latex, and this system was stirred and mixed. By doing so, the heat-sensitive gelling copolymer latex of the present invention (Examples 1 to 5) and the heat-sensitive gelling copolymer latex for comparison (Comparative Examples 1 to 6) were produced. In addition, as Comparative Example 7, a copolymer latex A containing no heat-sensitive gelling agent was prepared. In Table 2, heat-sensitive gelling agents a to c represent the following compounds. Heat-sensitive gelling agent a: Polyalkylene oxide-modified polysiloxane "F474" (manufactured by Shin-Etsu Silicone Co., Ltd.) Heat-sensitive gelling agent b: Alkylenephenol formalin condensate alkylene oxide adduct "Latemul 5150T"
(Kao Corporation) Heat-sensitive gelling agent c: Polyvinyl methyl ether (Wako Pure Chemical Industries, Ltd.)

<Evaluation of Heat-Sensitive Gelation Property> The BF viscosity at room temperature was measured for each of the (heat-sensitive gelation property) copolymer latexes produced in Examples and Comparative Examples. Then, each of the (heat-sensitive gelling) copolymer latex was placed in a resin container, the resin container was immersed in hot water at 90 ° C., and the BF viscosity at a temperature of 90 ° C. was measured. The results are also shown in Table 2 below. Here, it can be said that the larger the degree of change (increase) in the BF viscosity, the better the heat-sensitive gelation property.

[0059]

[Table 2]

From the results shown in Table 2, the thermosensitive gelling copolymer latexes (Examples 1 to 5) of the present invention have a small BF viscosity at room temperature and gel at a temperature of 90 ° C. It is understood that it has an excellent heat-sensitive gelation property.

<Production of Baking-type Chipping-resistant Coating> Using each of the (heat-sensitive gelling) copolymer latexes produced in the Examples and Comparative Examples, a baking-type chipping-resistant coating [solid content 75%, viscosity 5000
0 mPa · s] was produced. Formulation (heat-sensitive gelling property) Copolymer latex: 100 parts Polyethylene glycol: 10 parts Nonionic surfactant "Emulgen 910": 0.3 parts Sodium tripolyphosphate: 0.2 parts Titanium oxide: 20 parts Talc: 50 parts Part Sodium polyacrylate (thickener) ... 1.0 part

Each of the baking-type chipping-resistant paints obtained as described above was evaluated for the following coating film performance (baking property and adhesion). Baking Property A test piece was prepared by applying a baking-type chipping-resistant paint on an iron plate so that the thickness of the paint film (which means the thickness of the paint film after drying; the same applies below) is different. . Use this test piece in a hot air dryer (13
The paint was baked and dried by leaving it at 0 ° C. for 20 minutes. After the completion of baking and drying, the relationship between the thickness of the coating film and the occurrence of blisters and cracks in the coating film was observed (blisters and cracks are more likely to occur as the thickness of the coating film increases). The minimum value (μm) of the thickness of the coating film when blisters and cracks occur is shown in Table 3 below. It can be said that the larger this value, the better the seizure property.

Adhesion A baking type chipping-resistant paint was applied on an iron plate so that the thickness of the coating film was 300 μm, to prepare a test piece. The test piece was allowed to stand in a hot air dryer (130 ° C.) for 20 minutes to bake and dry the paint, and allowed to stand at room temperature for 24 hours. A razor was used to make a cut on the coating surface of this test piece to divide it into 100 pieces of 2 mm square coating pieces. Then, a peeling test was performed with an adhesive tape, and the number of peeled coating film pieces was measured. The results are shown in Table 3 below.

[0064]

[Table 3]

From the results shown in Table 3, the baking-type chipping-resistant paints produced using the heat-sensitive gelling copolymer latexes of the present invention (Examples 1 to 5) were found to have baking properties and base materials (iron plates).
It is understood that the adhesiveness with respect to is excellent.

[0066]

The heat-sensitive gelling copolymer latex of the present invention has an excellent heat-sensitive gelling property. Therefore,
Cracks and blisters do not occur in the coating layer formed through the drying treatment, and the coating layer formed has excellent adhesion to the substrate. And, the heat-sensitive gelling copolymer latex of the present invention having such excellent properties is a rubber dipping product, a backing material for carpet, a binder for non-woven fabric, a binder for paper processing, an adhesive for plywood, a civil engineering building product, It can be suitably used as a protective coating material, adhesive, and paint for all materials such as interior and exterior paints for electric appliances and office machines, paints for automobile exteriors, etc., especially when it is necessary to form a thick coating film. It is useful as a baking resistant chipping resistant coating.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI technical display location C09J 133/08 JDB 7921-4J D06M 15/693 D21H 17/31 // D04H 1/58 A 7199- 3B (72) Inventor Yasuhisa Watabe 2-11-24 Tsukiji, Chuo-ku, Tokyo Within Nippon Synthetic Rubber Co., Ltd.

Claims (1)

[Claims] 1. A monomer component (a) of 1 to 99.9% by weight, a monomer component (b) of 0.1 to 20% by weight, and a monomer component (c) of 0 to 98.9 below. Obtained by emulsion polymerization of 100 parts by weight of a monomer mixture consisting of 10% by weight and 0.1 to 20 parts by weight of an ethylenically unsaturated surfactant.
A heat-sensitive gelling copolymer latex, comprising a heat-sensitive gelling agent contained in a latex of a copolymer having a glass transition point of +30 to -70 ° C. Monomer component (a): Aliphatic conjugated diene monomer and /
Or (meth) acrylic acid alkyl ester monomer Monomer component (b): Monomer having functional group Monomer component (c): Monomer component (a) and monomer component (b) Copolymerizable monomer