JPH0113501B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an aqueous dispersion composition of carbonyl group-containing copolymer particles having a layered structure that provides a coating with excellent strength. Aqueous dispersions of carbonyl group-containing copolymers containing hydrazine derivatives are known (Japanese Unexamined Patent Publication No. 54
-110248, Publication No. 54-144432). This aqueous dispersion forms a film at a film forming temperature of 5 to 25°C. Moreover, it is noteworthy that a coating having strong adhesion to adherends such as cloth and metal can be provided. For example, JP-A-54-144432 discloses that () a water-soluble aliphatic dihydrazine compound and () a water-soluble A paint binder containing zinc salts, manganese salts, cobalt salts, or iron salts is applied to a cotton cloth tape to form a film, and when measured using a roll stripping device specified in DIN 53-289, it weighs 2 kg/3.5 It is stated that a cotton cloth tape having an adhesion strength of cm was obtained. When this aqueous dispersion of a carbonyl group-containing copolymer containing a hydrazine derivative is dried, the hydrazine derivative undergoes a crosslinking reaction with the carbonyl group of the copolymer to form a film. However, for aqueous dispersions, the glass transition temperature of the copolymer is determined depending on the purpose, and the type and amount of vinyl monomer are determined to achieve that temperature. Naturally, the carbonyl group content in the copolymer obtained by emulsion polymerization is also determined. Therefore, in some cases, crosslinking with the hydrazine derivative may not be carried out sufficiently. The present inventors set the glass transition point temperature by forming the carbonyl group-containing copolymer particles into a layered structure having a core and a shell, and using vinyl monomers as raw materials for the copolymer constituting the core and shell. Sufficient crosslinking is achieved by adjusting the composition and composition ratio, and by incorporating at least a carbonyl group-containing monomer capable of crosslinking with a hydrazine derivative into the vinyl monomer constituting the shell of the outermost layer. The present invention was completed based on the discovery that the glass transition point temperature can be easily set. That is, the present invention provides component (A): a hydrazine derivative having at least two hydrazine residues component (B): (a) methyl methacrylate, tertiary butyl acrylate, vinyl aromatic compound, vinyl halide, ethylene , methacrylonitrile, acrylonitrile, 10-75% by weight of monomers selected from
and (b) monomers selected from acrylic or methacrylic acid esters of alcohols having 2 to 8 carbon atoms, acrylic acid methyl esters, vinyl esters, 1,3-dienes,90
(c) 0 to 20% by weight of a carbonyl group-containing monomer having at least one aldo or keto group and one polymerizable double bond in the molecule; (d) 3 0.5 to 10% by weight of mono- or dicarboxylic acids having ~5 carbon atoms or/and amides of these acids substituted at the nitrogen atom by alkyl groups or/and alkylol groups having 1 to 4 carbon atoms A copolymer obtained by emulsion polymerization [] 100 parts by weight as a core, and further mixed with the monomers (a) to (d) above in the following proportions. Aqueous dispersion of particles of a carbonyl group-containing copolymer [] with a multilayer structure obtained by adding parts by weight and emulsion polymerizing to form shells of different copolymers on the outside of the core Monomer (a) 10~ 75% by weight Monomer (b) 90-25% by weight Monomer (c) 0.1-20% by weight Monomer (d) 0.5-10% by weight Carbonyl of the multilayer structure of component (B) above Component (A) is 0.02 per mole of carbonyl group in the group-containing copolymer.
The present invention provides an aqueous dispersion composition of carbonyl group-containing copolymer particles, characterized in that the carbonyl group-containing copolymer particles are blended in a proportion of 1 mol. In the present invention, the hydrazine derivative having at least two hydrazine residues as component (A) includes, for example, the following dicarboxylic acid dihydrazide containing 2 to 10 carbon atoms, particularly 4 to 6 carbon atoms. oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide and/or itaconic acid dihydrazide,
Aliphatic water-soluble dihydrazines having 2 to 4 carbon atoms, such as ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine and butylene-1,4-dihydrazine. Among these, adipic acid dihydrazide, isophthalic acid dihydrazide, and sebacic acid hydrazide are preferred. In addition, the copolymer particles having a multilayer structure of component (B) include at least a core inner part and an outer shell part.
Particles with a layered structure or more. The glass transition temperature (Tg) of the copolymer that forms the core of the particle is -32℃ ~
+60℃, preferably 0~30℃, that of the shell side -
30°C to +58°C, preferably -2°C to +28°C,
And the film forming temperature of the composition is 2 to 60°C, preferably
The type and amount of the vinyl monomers (a) to (d) to be polymerized are selected so that the temperature is 15 to 35°C. More preferably, the Tg of the copolymer constituting the shell is lower than the Tg of the copolymer constituting the core by at least 2°C, preferably by at least 10°C, to improve the film-forming properties of the composition. The ratio of the core to shell copolymer is preferably 5 to 250 parts by weight of the shell to 100 parts by weight of the core, taking into consideration the water resistance, yellowing resistance, blocking resistance, and adhesive strength of the resulting film. Emulsion polymerization is carried out so that the amount of is 20 to 100 parts by weight. The core and shell copolymers constituting the copolymer used in the present invention have different compositions, and the above-mentioned vinyl monomer compositions are compared and shown in the following table.

[Table] It is more economical and effective to use the carbonyl group-containing monomer of component (c) on the shell side in a quantitative proportion that is equal to or exceeds the quantitative proportion on the core side. This is preferable because crosslinking can be carried out. Furthermore, copolymer particles obtained by not using styrene or using styrene in a proportion of 40% by weight or less as the vinyl monomer (a) constituting the copolymer on the shell side have excellent yellowing resistance and can be used as pigments. , has the advantage of excellent adhesion to the base material. Examples of the vinyl monomer of component (a) include methyl methacrylate, vinyl aromatic compounds (e.g. styrene), tertiary butyl acrylate, acrylonitrile, methacrylonitrile, vinyl halides (e.g. vinyl chloride, vinylidene chloride), and ethylene. etc. These vinyl monomers of component (a) are:
While the vinyl monomer of component (b) acts to impart flexibility to the coating film, it acts to impart hardness to the coating film. Methyl methacrylate (hereinafter referred to as MMA) is used as the vinyl monomer of component (a) that forms the nucleus.
and styrene (hereinafter referred to as St) is 1/2 to 2/1
(on a weight basis), and when using MMA or a mixture of MMA and 40% by weight or less of St as component (a) constituting the shell, yellowing of the resulting coating film is prevented, The core part becomes hydrophobic and the water resistance of the coating film also improves. Next, as the vinyl monomer of component (b), for example, an alcohol having 2 to 8 carbon atoms such as ethanol, isopropanol, n-propanol, n-butanol, isobutanol or
- Esters of ethylhexanol with acrylic acid and/or methacrylic acid, methyl acrylate, vinyl acetate and vinyl propionate, methacrylamide propane sulfonic acid, 1-3 dienes, especially butadiene. Among these, 2-ethylhexyl acrylate, n-butyl acrylate and ethyl acrylate are preferred. Furthermore, as the carbonyl group-containing monomer of component (c), a monomer having at least one aldo group or keto group and one polymerizable double bond in the molecule,
That is, especially polymerizable monoolefinically unsaturated aldo and keto compounds, which contain an ester bond (-COO-), a carboxyl group (-
Compounds with only COOH) are excluded. In particular acrolein, diacetone acrylamide, formylstyrene, vinyl alkyl ketones preferably having 4 to 7 carbon atoms, such as in particular vinyl methyl ketone, vinyl ethyl ketone and vinyl isobutyl ketone and/or (In the formula, R ¹ is H or CH ₃ , R ² is H or an alkyl group having 1 to 3 carbon atoms, R ³ is an alkyl group having 1 to 3 carbon atoms, and R ⁴ is 1 to 3 carbon atoms.
(means an alkyl group having 4 carbon atoms)
Acrylic (methacrylic)oxyalkylpropanal, diacetone acrylate, acetonyl acrylate, diacetone acrylate, diacetone methacrylate, 2-hydroxypropyl acrylate-acetylacetate and butanediol-1,4-acrylate-acetylacetate are used. It will be done. Among these, diacetone acrylamide, acrolein and vinyl methyl ketone are preferred. Component (d) monomers include monoolefinically unsaturated mono- and/or dicarboxylic acids having 3 to 5 carbon atoms, such as acrylic acid,
Methacrylic acid and maleic acid, and/or their amides, such as acrylamide, methacrylamide, and/or their N-alkyl or N-alkylol derivatives, such as N-methylacrylamide, N-isobutylacrylamide, N-methylmethacrylamide, N-methylacrylamide, N-isobutylacrylamide, N-methylmethacrylamide, - Methylolacrylamide, N-methylolmethacrylamide, N-ethoxymethylacrylamide, N-n-butoxymethylacrylamide or N-isopropoxymethacrylamide, among which acrylic acid, methacrylic acid, itaconic acid and maleic acid are preferred. . The aqueous dispersion of component (B) of the present invention can be easily produced using conventional emulsion polymerization. For example, first stage emulsion polymerization is performed in a system of the vinyl monomer that forms the core portion of the polymer particles, an emulsifier, a polymerization initiator, and water, and after the polymerization is substantially completed, the monomer that forms the shell portion is A polymerization initiator is added to perform second stage emulsion polymerization. At this time, in order to make the synthetic resin particles produced have a two-layer structure, no emulsifier is added in the second stage emulsion polymerization, or even if added, the amount is limited to such an extent that new particles are not formed. Advantageously, care is taken to ensure that polymerization substantially proceeds in the polymer particles formed. The structure of the copolymer particles in the aqueous dispersion of component (B) of the present invention does not necessarily have to be a two-layer structure,
It is also possible to perform third-stage polymerization or more polymerization by changing the monomer composition as necessary to obtain a three-layered or more-layered structure. The emulsifier and polymerization initiator used in this emulsion polymerization are not particularly limited, but should be selected according to the monomer system so that the polymerization can be carried out smoothly. Examples of emulsifiers include anionic surfactants such as higher alcohol sulfate salts, alkylbenzene sulfonate salts, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenol ether sulfate salts, polyoxyethylene alkyl ethers, and polyoxyethylene alkyl ethers. Nonionic surfactants such as ethylene alkyl phenol ethers, ethylene oxide propylene oxide block copolymers, sorbitan derivatives, etc. are preferred. As a polymerization initiator, potassium persulfate,
Persulfates such as ammonium persulfate, hydrogen peroxide, peroxides such as benzoyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, and azobisisobutyronitrile are commonly used, but especially water-soluble Initiators and water-soluble redox-type initiator systems are preferred. It is blended into the aqueous dispersion of the carbonyl group-containing copolymer particles of component (B) obtained by emulsion polymerization in this manner.
The amount of the hydrazine derivative of component (A) is 0.02 to 1 mole of carbonyl group of the copolymer particles of component (B).
It is blended in a molar ratio, preferably 0.4 to 0.6 molar. In addition to these components (A) and (B), zinc sulfate, manganese sulfate, cobalt sulfate, water-soluble acetates of zinc, manganese, cobalt, and lead, nitrates, cobalt nitrate, manganese nitrate, and zinc nitrite and nitrous acid. A small amount of lead may be added. In addition, pigments commonly known in the art of paint formulation, extender pigments such as calcium carbonate, talc, clay, mica powder, barite, potassium, sodium or ammonium salts of condensed phosphates such as hexametaphosphoric acid, Ingredients such as sodium or ammonium salts of acrylic acid, common anionic or nonionic surfactants, dispersants and thickeners such as methylcellulose, ethylcellulose, propylcellulose, carboxymethylcellulose, and polyvinyl alcohol may be incorporated. good. The composition of the present invention is useful as a coating material for gloss paints, mastic top coating materials, soft mastic top coating materials, slate coating materials, etc., and provides coatings with excellent solvent resistance, durability, and yellowing resistance. . Furthermore, it has good adhesion to vinyl chloride resin and alkyd resin coatings, and is useful as a repair agent for old coatings. Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that parts and percentages in the examples are based on weight unless otherwise specified. Example 1 The following raw materials were charged into a reaction vessel equipped with a temperature controller, an anchor stirrer, a reflux condenser, a supply container, a thermometer, and a nitrogen inlet tube. 200 parts of water 35% aqueous solution of the sodium salt of the sulfuric acid half ester of p-nonylphenol (anionic emulsifier) reacted with 20 moles of ethylene oxide 5 parts of p-nonylphenol (nonionic emulsifier) reacted with 25 moles of ethylene oxide 20% solution
20 copies. Next, after purging the inside of the reaction vessel with nitrogen gas, 10% of the following feed was added, and the mixture was heated to 90%
heated to ℃. Feed Water 200 parts 35% aqueous solution of the above anionic emulsifier 25 parts Styrene 195 parts n-butyl acrylate 183 parts Acrolein 6 parts Acrylic acid 8 parts Acrylamide 8 parts. Furthermore, after charging 10% of 2.5 parts of potassium persulfate dissolved in 85 parts of water (feed) into the container, all remaining feed and 40% of the feed
Supplied into the container over 3.5 hours, and after supplying, 2
The feed was polymerized while maintaining the same temperature for a period of time to obtain a core copolymer. The following feeds were fed into this reaction vessel over a period of 1 hour, the remaining feeds were fed over a period of 0.5 hours, and the polymerization was completed by reacting at 90°C for 1.5 hours, and the reaction vessel was moved to room temperature. The mixture was cooled until an aqueous dispersion was obtained. Feed Styrene 44 parts n-butyl acrylate 47 parts Acrolein 5 parts Acrylic acid 2 parts Acrylamide 2 parts After adjusting the pH of the obtained aqueous dispersion to 7 to 8 with aqueous ammonia, 4 parts of adipic acid dihydrazide was added. Stirred for about 1 hour. The coating film obtained from the aqueous dispersion thus produced was excellent in blocking resistance, solvent resistance, and hardness, as shown in Table 2. Also, vinyl chloride resin,
Adhesion to the alkyd resin coating was also good. Comparative Example 1 The physical properties of a coating film formed from an aqueous dispersion (without the addition of adipic acid dihydrazide) obtained by performing the polymerization operation in the same manner as in Example 1 were as shown in Table 2. Comparative Example 2 Feed and more acrolein (component (C))
The aqueous dispersion obtained in the same manner as in Example 1, except for the following, formed a coating film with the physical properties shown in Table 2. Example 2 An aqueous dispersion obtained in the same manner as in Example 1, except that the composition of the feed was changed as shown in Table 1, formed a coating film with the physical properties shown in Table 2. Example 3 The following raw materials were charged into a reactor equipped with the same equipment as in Example 1. Water 200 parts Anionic emulsifier as in Example 1 (35% solution)
5 parts Nonionic emulsifier as in Example 1 (20% solution)
20 copies. The following raw materials were used as feeds. Water 150 parts Anionic emulsifier (35%) 24 parts Styrene 200 parts n-butyl acrylate 174 parts Acrolein 10 parts Acrylic acid 8 parts Acrylamide 8 parts As feed, dissolve 2.5 parts of potassium persulfate in 85 parts of water. I used the one I made. Furthermore, the following mixture was used as a feed. 50 parts of water 1 part of the above anionic emulsifier (35%) 1 part of methyl methacrylate 42 parts of n-butyl acrylate 49 parts of acrolein 5 parts of acrylic acid 2 parts of acrylamide 2 parts Polymerization was carried out in the same manner as in Example 1 using the above raw materials. An aqueous dispersion was obtained. This aqueous dispersion
After adjusting the pH to 7 to 8 with aqueous ammonia, 6 parts of sebacic acid dihydrazide was added and stirred for about 1 hour. Table 2 shows the physical properties of the coating film formed from the aqueous dispersion thus produced. Examples 4 to 7 Table 2 shows the physical properties of coating films formed from aqueous dispersions obtained in the same manner as in Example 1, except that the composition of the vinyl monomer used to obtain the copolymer was changed as shown in Table 1. . Comparative Example 3 The following raw materials were charged into a reaction vessel equipped with a temperature controller, an anchor stirrer, a reflux condenser, a supply container, a thermometer, and a nitrogen inlet tube. 200 parts of water 35% aqueous solution of the sodium salt of the sulfuric acid half ester of p-nonylphenol (anionic emulsifier) reacted with 20 moles of ethylene oxide 5 parts of p-nonylphenol (nonionic emulsifier) reacted with 25 moles of ethylene oxide 20 parts of 20% solution The following mixture was used as feed. 200 parts of water 35% solution of the above anionic emulsifier 25 parts of styrene 242 parts of n-butyl acrylate 227 parts of acrolein 11 parts of acrylic acid 10 parts of acrylamide As a feed, 2.5 parts of potassium persulfate are dissolved in 85 parts of water. I used the one I made. After purging the reactor with nitrogen gas, the feed
10% was added and the mixture was heated to 90°C. Then 10% of the feed was charged to the reactor.
Thereafter, the feeds and were fed simultaneously over a period of 3 to 3.5 hours. After the supply, the temperature was maintained at 90° C. for 1.5 hours, and then the reactor was cooled to room temperature to obtain a dispersion. After adjusting the pH after dispersion to 7 to 8 with aqueous ammonia, 4 parts of adipic acid dihydrazide was added and stirred for about 1 hour. Table 2 shows the physical properties of the coating film formed from the dispersion thus obtained by conventional one-step polymerization. The abbreviations for vinyl monomers in Table 1 are as follows. St: Styrene MMA: Methyl methacrylate n-BA: n-Butyl acrylate 2-EHA: 2-ethylhexyl acrylate ACr: Acrolein DAAM: Diacetone acrylamide AA: Acrylic acid A・Amid: Acrylamide In addition, the coating films in Table 2 The evaluation method is as follows. Preparation of paint: A paint with a pigment volume concentration of approximately 21% was created by blending pigments, thickeners, wetting agents, antifoaming agents, etc. with the aqueous dispersion. (1) Water resistance The obtained paint was applied to a flexible board to a thickness of 50μ (dry coating) and dried at 20°C for one week to prepare a test piece. Thereafter, it was immersed in water at 20°C for one week, and the appearance of the coating film and the presence or absence of blisters were evaluated. (2) Alkali resistance A test piece prepared in the same manner as in (1) was immersed in saturated lime water at 20°C, and evaluated in the same manner as in (1). (3) Blocking resistance 50μ of the obtained paint was applied on a glass plate (dry coating)
A test piece was prepared by coating the film and drying it at 20°C for 1 hour. Thereafter, gauze was placed on the coating film, a weight of 500 g was applied thereto, and the adhesiveness was evaluated after treatment at a predetermined temperature for 24 hours. (4) Hardness The pencil hardness of the test piece prepared in the same manner as in (3) was measured. (5) Solvent resistance A line was drawn on a test piece prepared in the same manner as in (3) using magic ink or office ink and then wiped off with ethyl acetate to evaluate the state of the coating film. (6) Adhesion to alkyd resin coating The obtained paint is applied onto the alkyd resin coating.
It was applied to a thickness of 50μ (dry coating) and dried at 20°C for one week. Thereafter, a peel test was conducted using cellophane tape to evaluate its adhesive strength. (7) Adhesion to vinyl chloride resin coating The adhesive strength to vinyl chloride resin was evaluated using the same method as in (6). (8) Resistance to yellowing A test piece obtained in the same manner as in (3) was irradiated with a germicidal ultraviolet lamp from a distance of 15 cm for one week, and the degree of yellowing was evaluated.

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Claims (1)

[Claims] 1 Component (A): Hydrazine derivative having at least two hydrazine residues (B) Component: (a) Methyl methacrylate, tertiary butyl acrylate, vinyl aromatic compound, vinyl halide 10 to 75% by weight of monomers selected from , ethylene, acrylonitrile, and methacrylonitrile
and (b) esters of acrylic acid or methacrylic acid of alcohols having 2 to 8 carbon atoms,
Methyl acrylate, vinyl ester, 1,3
- Diene, selected monomers 90-25% by weight
(C) 0 to 20% by weight of a carbonyl group-containing monomer having at least one aldo or keto group and one polymerizable double bond in the molecule; and (d) 3 to 5 carbon atoms. something that has or/
and a dicarboxylic acid or/and 0.5 to 10% by weight of an amide of these acids substituted with an alkyl group having 1 to 4 carbon atoms at the nitrogen atom and/or an alkylol group. Things [] 100
Monomer 5 to 250 parts by weight is used as a core, and the monomers (a) to (d) above are further mixed in the following proportions.
Aqueous dispersion of particles (a) of carbonyl group-containing copolymer with a multilayer structure obtained by adding parts by weight and emulsion polymerizing to form a shell of the copolymer on the outside of the core Monomer 10 to 75 weight % Monomer (b) 90-25% by weight Monomer (c) 0.1-20% by weight Monomer (d) 0.5-10% by weight Carbonyl group-containing multilayer structure of component (B) above Component (A) is 0.02 per mole of carbonyl group in the copolymer.
An aqueous dispersion composition of carbonyl group-containing copolymer particles, characterized in that the carbonyl group-containing copolymer particles are blended in a proportion of 1 mol. 2 The amount of monomer (c) in the copolymer constituting the shell of particles formed by emulsion polymerization in the subsequent step is the amount of monomer (c) in the copolymer constituting the core obtained by emulsion polymerization first. The aqueous dispersion composition of carbonyl group-containing copolymer particles according to claim 1, characterized in that the content is equal to or greater than the proportion of the monomer (c). 3. The vinyl monomer of component (a) that forms the core of the carbonyl group-containing copolymer particles with a multilayer structure of component (B) is
It contains styrene or styrene and methyl methacrylate, and the vinyl monomer of component (a) forming the shell is methyl methacrylate or
2. The aqueous dispersion composition according to claim 1, comprising methyl methacrylate and 40% by weight or less of styrene. 4. Copolymer [Claim 1] The glass transition temperature of the copolymer constituting the shell of the particle is 2° C. or more lower than the glass transition temperature of the copolymer constituting the core. An aqueous dispersion composition of.