JP2005344013A - Biodegradable resin-containing aqueous dispersion and method for producing the same aqueous dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodegradable resin-containing aqueous dispersion forming a coated film having excellent finish properties and water resistance and to provide a method for producing the dispersion. <P>SOLUTION: The biodegradable resin-containing aqueous dispersion has ≤1,000 nm average particle diameter of a dispersed resin containing a (co)polymer composed of a biodegradable resin (A) and a polymerizable unsaturated monomer (B) as a constituent unit. The aqueous dispersion can be produced by a method for finely dispersing the biodegradable resin (A) and the polymerizable unsaturated monomer (B) in an aqueous medium so as to ≤1,000 nm average particle diameter and polymerizing the resultant emulsion. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes a biodegradable resin-containing water dispersion that contains a biodegradable material, has excellent storage stability, and can form a coating film having good drying, finishing, and water resistance. The present invention relates to a method for producing the aqueous dispersion and an aqueous coating composition containing the aqueous dispersion.

  In recent years, the environmental pollution of the earth has become obvious, and the construction of a recycling-oriented society that takes into account the reduction of environmental burdens is progressing, and the paint industry is also demanding the development of products that are friendly to the global environment. In such a situation, it does not contain a large amount of volatile organic compounds (VOC) such as toluene and xylene, which cause deterioration of the indoor environment. Various coating agents using an active material have been proposed. For example, Patent Document 1 describes a biodegradable resin aqueous dispersion in which a specific biodegradable resin is dispersed and stabilized in water in the presence of a specific plasticizer and a dispersion stabilizer. Has been. The dispersion is excellent in safety and environment, but when applied as a resin emulsion for water-based paints, the average particle size of the dispersion is as large as about 3000 to 12000 nm, and the storage stability and finish are insufficient. In addition, there is a problem that the use is restricted in terms of physical properties of the coating film.

JP 2002-121288 A

  An object of the present invention is to provide a biodegradable resin-containing aqueous dispersion having excellent storage stability, dryability, finish, and water resistance, a method for producing the dispersion, and an aqueous coating composition containing the dispersion. It is to be.

The present inventors have disclosed an aqueous dispersion characterized in that the particle diameter of a dispersion resin containing a (co) polymer comprising a biodegradable resin and a polymerizable unsaturated monomer as a constituent unit is a specific average particle diameter. And the above-mentioned problems can be solved by a method of polymerizing an emulsion obtained by finely dispersing a mixture containing a biodegradable resin and a polymerizable unsaturated monomer in an aqueous medium to have a specific average particle size, The present invention has been reached. That is, the present invention is 1. A biodegradable resin containing (A) biodegradable resin and (B) a dispersion resin containing a (co) polymer composed of a polymerizable unsaturated monomer as a constituent unit has an average particle size of 1000 nm or less. Water dispersion,
2. The biodegradable resin-containing aqueous dispersion according to 1, wherein the biodegradable resin (A) is one or more compounds selected from the group consisting of cellulose acetate derivatives, chitin, and polybutylene succinate.
3. The biodegradable resin-containing aqueous dispersion according to item 1 or 2, wherein the polymerizable unsaturated monomer (B) contains a polymerizable unsaturated monomer containing a carbonyl group,
4). The biodegradable resin-containing aqueous dispersion according to any one of items 1 to 3, wherein the polymerizable unsaturated monomer (B) contains a fatty acid-modified polymerizable unsaturated monomer,
5). 5. The theoretical glass transition temperature of the (co) polymer comprising the polymerizable unsaturated monomer (B) is in the range of −20 to 50 ° C. An aqueous dispersion containing a biodegradable resin,
6). 6. The biodegradable resin-containing composition according to any one of items 1 to 5, wherein the (co) polymer comprising the polymerizable unsaturated monomer (B) has a weight average molecular weight of 250,000 or less. Water dispersion,
7). The dispersion resin contains at least one additive selected from the group consisting of (C) a plasticizer, an ultraviolet absorber, an ultraviolet stabilizer, and a metal dryer as a constituent unit. A biodegradable resin-containing aqueous dispersion of
8. A biodegradable resin having a core / shell structure in which the dispersion resin according to any one of items 8 to 7 is used as a core, and the core has at least one polymer outer shell as a shell. Containing water dispersion,
9. (A) A mixture (I) containing a biodegradable resin and (B) a polymerizable unsaturated monomer is finely dispersed in an aqueous medium so that the average particle diameter is 1000 nm or less, and the resulting emulsion is polymerized. A method for producing a biodegradable resin-containing aqueous dispersion characterized by
10. (A) A mixture (I) containing a biodegradable resin and (B) a polymerizable unsaturated monomer is finely dispersed in an aqueous medium so that the average particle diameter is 1000 nm or less, and the resulting emulsion is polymerized. In the dispersion obtained by adding a monomer component (II) containing a polymerizable unsaturated monomer (D) and polymerizing, a method for producing a biodegradable resin-containing aqueous dispersion,
11. Item 11. The method according to Item 9 or 10, wherein the biodegradable resin (A) is one or more compounds selected from the group consisting of a cellulose acetate derivative, chitin, and polybutylene succinate.
12 The method according to any one of items 9 to 11, wherein the polymerizable unsaturated monomer (B) contains a polymerizable unsaturated monomer containing a carbonyl group,
13. The method according to any one of items 9 to 12, wherein the polymerizable unsaturated monomer (B) comprises a fatty acid-modified polymerizable unsaturated monomer,
14 Item 14. The mixture according to any one of items 9 to 13, wherein the mixture (I) contains at least one additive (C) selected from the group consisting of a plasticizer, an ultraviolet absorber, an ultraviolet stabilizer, and a metal dryer. Method,
15. An aqueous resin composition containing the biodegradable resin-containing aqueous dispersion according to any one of items 1 to 8;
16. An aqueous coating composition containing the aqueous resin composition according to item 15.15,
17. A method for forming a coating film, characterized in that the surface to be coated is coated with the aqueous coating composition according to item 16,
A coated article obtained by the method for forming a coating film according to Item 18.17,
About.

  Since the biodegradable resin-containing aqueous dispersion of the present invention contains a biodegradable resin and is excellent in various physical properties, it can be widely applied in the fields of paints, molding agents, inks, adhesives and the like. Moreover, according to the manufacturing method of this invention, the water dispersion containing biodegradable resin can be manufactured stably. In addition, according to the aqueous coating composition containing the biodegradable resin-containing aqueous dispersion of the present invention, the storage stability is excellent and the film forming property is excellent, and the formed coating film has good drying and finishing properties. It has a remarkable effect of being excellent in performance such as water resistance and durability.

  The biodegradable resin-containing aqueous dispersion of the present invention has an average particle diameter of 1000 nm of a dispersion resin containing (A) biodegradable resin and (B) a (co) polymer composed of a polymerizable unsaturated monomer as a constituent unit. Hereinafter, it is an aqueous dispersion particularly in the range of 50 to 500 nm. If the average particle diameter exceeds 1000 nm, the finish and storage stability are inferior and the practicality is lowered, which is not preferable. In the present specification, the average particle size is “SALD-3100” (trade name, manufactured by Shimadzu Corporation, laser diffraction particle size distribution measuring device), and the sample is diluted with deionized water, and is about 20 ° C. The measured value. Hereinafter, each structural unit constituting the dispersion resin in the biodegradable resin-containing aqueous dispersion of the present invention will be described.

Biodegradable resin (A)
In the biodegradable resin-containing aqueous dispersion of the present invention, any conventionally known biodegradable resin (A) can be used without limitation. Specifically, cellulose acetate, cellulose acetate butyrate, cellulose acetate propio Cellulose acetate derivatives such as nitrates, polysaccharides such as chitin and chitosan; polylactic acids such as polylactic acid, copolymers of lactic acid and other hydroxycarboxylic acids; polybutylene succinate, polyethylene succinate, polybutylene adipate, etc. Polybasic acid polyesters; polycaprolactones such as polycaprolactone and copolymers of caprolactone and hydroxycarboxylic acid; polyhydroxybutyrates such as polyhydroxybutyrate and copolymers of polyhydroxybutyrate and hydroxycarboxylic acid Polyhydroxybutyric acid, poly Aliphatic polyesters such as copolymers of hydroxybutyric acid and other hydroxycarboxylic acids; polyamino acids; polyester polycarbonates; water-soluble polymers such as polyethylene glycol and polyvinyl alcohol; natural resins such as shellac and rosin; These may be used, and these may be used alone or in combination of two or more.

  The weight average molecular weight of the biodegradable resin (A) is, for example, 5,000 to 1,000,000, preferably 10,000 to 500,000.

  In the present specification, the weight average molecular weight is a value obtained by converting the weight average molecular weight measured by gel permeation chromatography using tetrahydrofuran as a solvent based on the weight average molecular weight of polystyrene. As the column, “TSKgel G-4000H × L”, “TSKgel G-3000H × L”, “TSKgel G-2500H × L”, “TSKgel G-2000H × L” (all manufactured by Tosoh Corporation) were used. Can be mentioned.

  In the present invention, the biodegradable resin (A) is preferably a resin that can be dissolved in the polymerizable unsaturated monomer (B) described below, and examples thereof include cellulose acetate derivatives, chitin, and polybutylene succinate. In particular, a cellulose acetate derivative, particularly cellulose acetate butyrate is preferable.

  The cellulose acetate butyrate (hereinafter sometimes referred to as CAB) is a cellulose derivative obtained by further butyrylating a partially acetylated product of cellulose, and the acetyl group content is 1 to 30% by weight, preferably 1 to 14% by weight, butyryl group content is preferably in the range of 16-60% by weight, preferably 35-60% by weight, as measured by the viscosity measurement method described in ASTM-D 1343-54T (Formul A). The viscosity is desirably in the range of 0.005 to 5 seconds, preferably 0.005 to 1 second. Moreover, the thing in the range whose number average molecular weight is about 10,000-120,000 is preferable. Specifically, a product of US Eastman Kodak Company, for example, a trade name [butylyl group content (% by weight) up to the second digit of the former number, and hydroxyl group content (% by weight) is the third digit. And the latter number indicates viscosity (seconds)], CAB-171-2, CAB-381-0.5, CAB-381-2, CAB-531-1, CAB-551-0.2, Grades such as CAB-551-0.1 and CAB-551-0.01 are advantageously used.

Polymerizable unsaturated monomer (B)
Examples of the polymerizable unsaturated monomer (B) include compounds containing one or more, preferably one polymerizable unsaturated group in the molecule. Examples of the polymerizable unsaturated group include a vinyl group and a (meth) acryloyl group. Specific examples of the polymerizable unsaturated monomer (B) include methyl (meth) acrylate, ethyl (meth) acrylate, and n-propyl. (Meth) acrylate, i-propyl (meth) acrylate, n-butyl (meth) acrylate, i-butyl (meth) acrylate, tert-butyl (meth) acrylate, n-hexyl (meth) acrylate, octyl (meth) acrylate , 2-ethylhexyl (meth) acrylate, nonyl (meth) acrylate, tridecyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, “isostearyl acrylate” (manufactured by Osaka Organic Chemical Co., Ltd.), cyclohexyl (meth) Acrylate, methyl Polymers having alkyl or cycloalkyl (meth) acrylates such as cyclohexyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, cyclododecyl (meth) acrylate; isobornyl groups such as isobornyl (meth) acrylate Polymerizable unsaturated monomers having an adamantyl group such as adamantyl (meth) acrylate; glycidyl (meth) acrylate, β-methylglycidyl (meth) acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3 , 4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, polymerizable unsaturated monomers having an epoxy group such as allyl glycidyl ether; styrene, α-methyls Aromatic vinyl monomers such as len and vinyl toluene; vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris (2-methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane, γ- (meth) acryloyloxypropyl Polymerizable unsaturated monomer having alkoxysilyl group such as triethoxysilane; Siloxane macromonomer such as polydimethylsiloxane macromonomer; Perfluoroalkyl such as perfluorobutylethyl (meth) acrylate and perfluorooctylethyl (meth) acrylate ( (Meth) acrylate; polymerizable unsaturated monomer having an alkyl fluorine group such as fluoroolefin; polymerizable unsaturated monomer having a photopolymerizable functional group such as maleimide group; N-vinylpyrrolidone; Polymeric unsaturated compounds having a carboxyl group such as (meth) acrylic acid, fumaric acid, itaconic acid, maleic acid, crotonic acid, β-carboxyethyl acrylate, etc., vinyl compounds such as tylene, butadiene, chloroprene, vinyl propionate and vinyl acetate Monomers; unsaturated carboxylic anhydrides such as maleic anhydride and itaconic anhydride; (meth) acrylonitrile, (meth) acrylamide, dimethylaminopropyl (meth) acrylamide, dimethylaminoethyl (meth) acrylate, and glycidyl (meth) acrylate -Containing polymerizable unsaturated monomers such as adducts of amines and amines; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, hydroxybutyl (Meta) Hydroxyl groups such as alkyl (meth) acrylates having 2 to 8 carbon atoms of (meth) acrylic acid such as acrylate, allyl alcohol, and ε-caprolactone modified products of the above hydroxy (meth) acrylates having 2 to 8 carbon atoms (Meth) acrylate having a hydroxyl group; polymerizable unsaturated monomer having a hydroxyl group such as (meth) acrylate having a polyoxyethylene chain having a molecular terminal hydroxyl group: having a polyoxyethylene chain having a molecular terminal alkoxy group (meth) Acrylate; 2-acrylamido-2-methylpropanesulfonic acid, allylsulfonic acid, styrenesulfonic acid sodium salt, sulfoethyl methacrylate and polymerizable unsaturated monomer having a sulfonic acid group such as sodium salt or ammonium salt thereof; 2-hydroxy- 4- (3-Methacryloy Oxy-2-hydroxypropoxy) benzophenone, 2-hydroxy-4- (3-acryloyloxy-2-hydroxypropoxy) benzophenone, 2,2′-dihydroxy-4- (3-methacryloyloxy-2-hydroxypropoxy) benzophenone, Hydroxybenzophenones such as 2,2'-dihydroxy-4- (3-acryloxy-2-hydroxypropoxy) benzophenone, 2,4-dihydroxybenzophenone, 2,2 ', 4-trihydroxybenzophenone and glycidyl (meth) acrylate Or a polymerizable unsaturated monomer having a UV-absorbing functional group such as 2- (2′-hydroxy-5′-methacryloyloxyethylphenyl) -2H-benzotriazole; 4- (meth) acryloyl Oxy 1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-cyano-4- (meth) acryloylamino-2,2, 6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4-cyano-4- (meta ) Acryloylamino-2,2,6,6-tetramethylpiperidine, 4-crotonoyloxy-2,2,6,6-tetramethylpiperidine, 4-crotonoylamino-2,2,6,6-tetramethyl UV-stable polymerizable unsaturated monomers such as piperidine, 1-crotonoyl-4-crotonoyloxy-2,2,6,6-tetramethylpiperidine; , Having a carbonyl group such as diacetone acrylamide, diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrene, vinyl alkyl ketone having 4 to 7 carbon atoms (eg, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone) Polymerizable unsaturated monomer: allyl (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, 1 , 3-butylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, 1,4-butanediol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexanediol (meth) Acrylate, pentaerythritol di (meth) acrylate, pentaerythritol tetra (meth) acrylate, glycerol di (meth) acrylate, 1,1,1-trishydroxymethylethane ( (Meth) acrylate, 1,1,1-trishydroxymethylethane tri (meth) acrylate, 1,1,1-trishydroxymethylpropane tri (meth) acrylate, triallyl isocyanurate, diallyl Polyvinyl compounds having at least two polymerizable unsaturated groups in one molecule such as terephthalate and divinylbenzene; fatty acid-modified polymerizable unsaturated monomers can be mentioned, and these can be used alone depending on the desired performance. Or 2 or more types are used suitably.

  Moreover, in this invention, it is suitable for a polymerizable unsaturated monomer (B) to contain the polymerizable unsaturated monomer containing a carboxyl group.

  Examples of the polymerizable unsaturated monomer containing a carboxyl group include (meth) acrylic acid, fumaric acid, itaconic acid, maleic acid, crotonic acid, β-carboxyethyl acrylate, etc., either alone or in combination of two or more. Can be used. With this monomer, the storage stability of the obtained aqueous dispersion can be improved.

  The proportion of the polymerizable unsaturated monomer containing a carboxyl group is 0.1 to 5.0% by weight, preferably 0.3 to 4.5% by weight, more preferably in the polymerizable unsaturated monomer (B). 0.5 to 4.0% by weight is preferred.

  The polymerizable unsaturated monomer (B) preferably contains a polymerizable unsaturated monomer having an alkyl group having 4 or less carbon atoms. Examples of the polymerizable unsaturated monomer containing an alkyl group having 4 or less carbon atoms include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, i-propyl (meth) acrylate, and n-butyl. (Meth) acrylate, i-butyl (meth) acrylate, tert-butyl (meth) acrylate, etc. can be mentioned, These can be used individually or in combination of 2 or more types. Since the monomer has good compatibility with the biodegradable resin (A), it has an effect on the stability of the dispersion before polymerization and the storage stability of the aqueous dispersion after polymerization.

  The use ratio of the polymerizable unsaturated monomer containing an alkyl group having 4 or less carbon atoms is 10 to 95% by weight, preferably 15 to 85% by weight, more preferably 20 to 75% by weight in the polymerizable unsaturated monomer. Is preferred.

  Further, the other polymerizable unsaturated monomer (B) preferably contains a polymerizable unsaturated monomer containing a carbonyl group.

  Examples of the polymerizable unsaturated monomer containing a carbonyl group include compounds having one carbonyl group and one polymerizable unsaturated bond in one molecule. Specifically, for example, acrolein, diacetone acrylamide, Examples include diacetone methacrylamide, acetoacetoxyethyl methacrylate, formylstyrene, vinyl alkyl ketones having 4 to 7 carbon atoms (for example, vinyl methyl ketone, vinyl ethyl ketone, vinyl butyl ketone) and the like. Two or more types can be used in combination. Of these, diacetone (meth) acrylamide is particularly preferred.

  By using what comprises a polymerizable unsaturated monomer containing a carbonyl group as at least a part of the other polymerizable unsaturated monomer (B) and blending the resulting dispersion with a hydrazine derivative described later, Auxiliary crosslinking between the monomer-derived carbonyl group and the hydrazine derivative can be promoted, the drying property of the coating film can be further improved, and a coating film having excellent physical properties such as weather resistance and water resistance can be formed. A composition can be prepared. The proportion of the monomer used is suitably 0.5 to 35% by weight, preferably 1 to 20% by weight in the polymerizable unsaturated monomer (B).

  The other polymerizable unsaturated monomer (B) preferably contains a fatty acid-modified polymerizable unsaturated monomer.

  The fatty acid-modified polymerizable unsaturated monomer includes a polymerizable unsaturated monomer having a polymerizable unsaturated group at the terminal of a fatty acid-derived hydrocarbon chain. Examples of the fatty acid-modified polymerizable unsaturated monomer include those obtained by reacting a fatty acid with a polymerizable unsaturated monomer containing an epoxy group or a polymerizable unsaturated monomer containing a hydroxyl group.

  Examples of fatty acids include dry oil fatty acids, semi-dry oil fatty acids and non-dry oil fatty acids. Examples of dry oil fatty acids and semi-dry oil fatty acids include fish oil fatty acids, dehydrated castor oil fatty acids, safflower oil fatty acids, and linseed oil fatty acids. , Soybean oil fatty acid, sesame oil fatty acid, poppy oil fatty acid, eno oil fatty acid, hemp seed fatty acid fatty acid, grape kernel oil fatty acid, corn oil fatty acid, tall oil fatty acid, sunflower oil fatty acid, cottonseed oil fatty acid, walnut oil fatty acid, rubber seed oil fatty acid, hygiene Acid fatty acid etc. are mentioned, and non-drying oil fatty acid includes, for example, coconut oil fatty acid, hydrogenated coconut oil fatty acid, palm oil fatty acid and the like. These can be used alone or in combination of two or more. Furthermore, these fatty acids can be used in combination with caproic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid and the like.

  As the monomer that can be reacted with the fatty acid in order to produce a fatty acid-modified polymerizable unsaturated monomer, a polymerizable unsaturated monomer containing an epoxy group is suitable. For example, glycidyl (meth) acrylate, β-methyl glycidyl (meta ) Acrylate, 3,4-epoxycyclohexylmethyl (meth) acrylate, 3,4-epoxycyclohexylethyl (meth) acrylate, 3,4-epoxycyclohexylpropyl (meth) acrylate, allyl glycidyl ether and the like.

  By using at least a part of the other polymerizable unsaturated monomer (B) that contains a fatty acid-modified polymerizable unsaturated monomer, the stability of the dispersion in the polymerization stage can be improved and formed. It is possible to impart a feeling of meat and oxidative curability to the coating film. The proportion of the monomer used is suitably 0.5 to 40% by weight, preferably 1 to 30% by weight in the polymerizable unsaturated monomer (B).

  In the present invention, the polymerizable unsaturated monomer (B) is composed of a total polymerizable unsaturated monomer to be used from the viewpoint of film forming properties of the formed coating film and coating film properties such as water resistance and durability. It is desirable to select the (co) polymer so that the theoretical glass transition temperature is within a range of -20 to 50 ° C, preferably -10 to 35 ° C.

In the present invention, the glass transition temperature (absolute temperature) is a value calculated from the following equation.
1 / Tg = W ₁ / T ₁ + W ₂ / T ₂ +... W _n / T _{n
W 1, W} 2 ··· _{W n} in the formula is the weight percent of each monomer (= (amount / total weight of the monomers in each _{monomer) × 100), T 1,} T 2 ··· T n is It is the glass transition temperature (absolute temperature) of the homopolymer of each monomer. The glass transition temperature of the homopolymer of each monomer is a value according to Polymer Hand Book (Second Edition, edited by J. Brandrup / EHImmergut), and the glass transition temperature of the monomer not described in this document is the weight of the homopolymer. The average molecular weight was synthesized so as to be about 50,000, and the value obtained by measuring the glass transition temperature by differential scanning thermal analysis was used.

  In the present invention, the (co) polymer comprising the fully polymerizable unsaturated monomer (B) to be used is used from the viewpoint of the film forming properties of the formed coating film and the coating film properties such as water resistance and durability. It is desirable that the weight average molecular weight is 250,000 or less, preferably 5,000 to 240000. If it exceeds 250,000, the average particle size of the dispersed resin in the aqueous dispersion increases, and the finish and the physical properties of the coating film may be inferior.

  In the present invention, the composition ratio of the (co) polymer comprising the biodegradable resin (A) and the polymerizable unsaturated monomer (B) is 1/99 to 85/15 in terms of A / B weight ratio, preferably 5/95 to 70/30, more preferably 5/95 to 60/40 is desirable.

At least one additive (C) selected from the group consisting of a plasticizer, an ultraviolet absorber, an ultraviolet stabilizer and a metal dryer
The dispersion resin in the biodegradable resin-containing aqueous dispersion of the present invention includes a plasticizer and an ultraviolet absorber in addition to the (co) polymer comprising the biodegradable resin (A) and the polymerizable unsaturated monomer (B). As a constituent unit, at least one additive (C) selected from the group consisting of an agent, an ultraviolet stabilizer and a metal dryer can be contained.

  As the plasticizer, those that are highly safe for the human body are desirable. Specifically, for example, citric acid derivatives such as triethyl citrate, tributyl citrate, acetyl triethyl citrate, and tributyl acetyl citrate; diethylene glycol diacetate , Ether ester derivatives such as triethylene glycol diacetate and triethylene glycol dipropionate; glycerol derivatives such as glycerol triacetate, glycerol tripropionate and glycerol tributyrate; condensates of adipic acid and 1,4-butanediol, etc. And polyhydroxycarboxylic acids such as polycaprolactone and polypropiolactone. These may be used alone or in combination of two or more. Of these, glycerin derivatives and adipic acid derivatives are particularly preferable in terms of high plasticizing effect.

  The plasticizer can improve the film forming property of the formed coating film, and can provide good finish and water resistance. The use ratio of the plasticizer is 0.1 to 30% by weight, preferably 0.1 to 15% by weight, based on the total weight of the biodegradable resin (A) and the polymerizable unsaturated monomer (B). is there.

  Examples of the ultraviolet absorber include salicylic acid derivatives such as phenyl salicylate, p-octylphenyl salicylate, 4-t-butylphenyl salicylate; 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxy. Benzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone trihydrate, 2,2'- Dihydroxy-4,4'-dimethoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, sodium 2,2'-dihydroxy-4,4'-dimethoxy-5-sulfobenzophenone , 2,2 ', 4,4'-tet Lahydroxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 5-chloro-2-hydroxybenzophenone, resorcinol monobenzoate, 2,4-dibenzoyl resorcinol, 4,6-dibenzoyl resorcinol, Benzophenones such as hydroxydodecylbenzophenone and 2,2'-dihydroxy-4 (3-methacryloxy-2-hydroxypropoxy) benzophenone; benzotriazo- such as 2- (2'-hydroxy-5'-methylphenyl) benzotriazole And other compounds (such as oxalic anilide and cyanoacrylate).

  As the UV stabilizer, 2- (3-t-butyl-5-methyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl)- 5-chlorobenzotriazole, poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6- Tetramethyl-4-piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}], dimethyl succinate 1- (2-hydroxyethyl) -4-hydroxy-2 , 2,6,6-tetramethylpiperidine polycondensate, 2,4-di-t-butylphenyl-3,5-di-t-butyl-4-hydroxybenzoate, bis- (2,2 ′, 6, 6'-tetramethyl-4- Piperidinyl) sebate, 4-benzoyloxy-2,2 ', 6,6'-tetramethylpiperidine and the like.

  The said ultraviolet absorber and / or ultraviolet stabilizer may be used independently, can also be selected suitably and can be used in combination. The ultraviolet absorber is used in an amount of 0.1 to 5.0% by weight, preferably 0.2 to 2.0%, based on the total weight of the biodegradable resin (A) and the polymerizable unsaturated monomer (B). Weight percent is preferred. The ultraviolet stabilizer is used in an amount of 0.1 to 5.0% by weight, preferably 0.2 to 3.0% by weight based on the total weight of the biodegradable resin (A) and the polymerizable unsaturated monomer (B). Weight percent is preferred.

  In addition, the metal dryer is blended in order to promote the oxidative hardening of the formed coating film when the dispersion resin has a group having oxidative curability, for example, aluminum, calcium, cerium. , A salt of at least one metal selected from the group consisting of cobalt, iron, lithium, magnesium, manganese, zinc, and zirconium and an acid. Examples of the acid include capric acid, caprylic acid, isodecanoic acid, Linolenic acid, naphthenic acid, neodecanoic acid, octenoic acid, oleic acid, palmitic acid, resin acid, ricinoleic acid, soybean oil fatty acid, stearic acid, tall oil fatty acid and the like can be mentioned. The use ratio of the metal dryer is 0.1 to 10% by weight, preferably 0.5 to 7% by weight based on the total weight of the biodegradable resin (A) and the polymerizable unsaturated monomer (B). is there.

  In addition, the dispersion resin in the biodegradable resin-containing aqueous dispersion of the present invention may contain a surfactant as a constituent unit from the viewpoint of particle stability. As the surfactant, anionic surfactants and nonionic surfactants are suitable. Examples of the anionic surfactants include sodium salts such as alkylsulfonic acid, alkylbenzenesulfonic acid, and alkylphosphoric acid, and ammonium. Salt.

  On the other hand, nonionic surfactants include polyoxyethylene oleyl ether, polyoxyethylene stearyl ether, polyoxyethylene lauryl ether, polyoxyethylene tridecyl ether, polyoxyethylene phenyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene Ethylene octylphenyl ether, polyoxyethylene monolaurate, polyoxyethylene monostearate, polyoxyethylene monooleate, sorbitan monolaurate, sorbitan monostearate, sorbitan monostearate, sorbitan trioleate, polyoxyethylene sorbitan mono Examples include laurate, lecithin, and casein.

  In addition, a polyoxyalkylene group-containing anionic surfactant having an anionic group and a polyoxyalkylene group such as a polyoxyethylene group or a polyoxypropylene group in one molecule, the anionic group and a polymerizable unsaturated group May be used as a reactive anionic surfactant. In addition, the reactive anionic surfactant may have a polyoxyalkylene group. These may be used alone or in combination of two or more according to the desired performance. The amount of the surfactant (C) used is 0.1 to 20% by weight, preferably 0.2 to 15% by weight based on the total weight of the components (A) and (B) used from the stability during polymerization. %, More preferably 0.3 to 12% by weight.

  In addition, the biodegradable resin-containing aqueous dispersion of the present invention may have a core / shell structure in which the above-mentioned dispersion resin is a core and one or more polymer outer shells are used as a shell with respect to the core. By further coating the outer layer of the dispersion resin including the biodegradable resin (A) with a polymer layer, for example, the resin composition of each layer, the set Tg, the set molecular weight, the kind of (co) polymerized functional group, etc. Since it can set suitably, the freedom degree of the resin design for expressing the target physical property can be expanded.

  There is no restriction | limiting in particular as a polymer outer shell in this invention, For example, the (co) polymer which consists of a polymerizable unsaturated monomer (D) can be mentioned. The polymerizable unsaturated monomer (D) can be used by selecting one or more kinds from those exemplified for the polymerizable unsaturated monomer (B). Moreover, the molecular weight of a polymer outer shell can be adjusted as necessary using a chain transfer agent described later.

  In the biodegradable resin-containing aqueous dispersion having the core / shell structure, the glass transition temperature of the (co) polymer comprising the polymerizable unsaturated monomer (B) constituting the core part is -30 to 30 ° C, The temperature is preferably -20 to 25 ° C, and the glass transition temperature of the (co) polymer comprising the polymerizable unsaturated monomer (D) constituting the shell portion is -20 to 100 ° C, preferably -15 to 15 ° C. It is preferable to be within the range of 80 ° C.

  The method for producing the biodegradable resin-containing aqueous dispersion of the present invention is not particularly limited, but the mixture (I) containing the biodegradable resin (A) and the polymerizable unsaturated monomer (B) is aqueous. A method of polymerizing a monomer emulsion finely dispersed in a medium so as to have a thickness of 1000 nm or less is desirable.

  According to the above method, the dispersion is stable even in the polymerization stage, and the average particle diameter of the dispersion resin after polymerization can be within the above range.

  In the method of the present invention, the mixture (I) can also contain the additive (C). Thereby, the additive (C) can be contained in the dispersion resin, and as a result, the additive (C) is uniformly dispersed in the coating film formed using the aqueous dispersion of the present invention. In addition, after the coating film is formed, it is not eluted by rainwater or the like, and the effect is stably exhibited over a long period of time.

  In the present invention, polymerization may be performed in the presence of a chain transfer agent for the purpose of adjusting the molecular weight of the biodegradable resin-containing aqueous dispersion. Examples of the chain transfer agent include compounds having a mercapto group, specifically, lauryl mercaptan, t-dodecyl mercaptan, octyl mercaptan, 2-ethylhexyl thioglycolate, 2-methyl-5-tert-butylthio. Examples thereof include phenol, mercaptoethanol, thioglycerol, mercaptoacetic acid (thioglycolic acid), mercaptopropionate, and n-octyl-3-mercaptopropionate. The amount of the chain transfer agent is preferably in the range of 0.1 to 10% by weight based on the total of components (A) and (B).

  In the production method of the present invention, the monomer emulsion is obtained by dispersing the monomer mixture (I) in an aqueous medium.

  Examples of the aqueous medium include water or a water-organic solvent mixed solution obtained by dissolving water and an organic solvent such as a water-soluble organic solvent. For example, a mixed system of alcohol such as methanol, ethanol, 1-propanol, 2-propanol and water can be used.

  The monomer emulsion is desirably finely dispersed by a disperser having high energy shearing ability. Examples of the disperser include a high-pressure emulsifier, an ultrasonic emulsifier, a high-pressure colloid mill, a high-pressure homogenizer, and a high-speed stirrer. The high pressure here is, for example, about 10 to 1000 MPa, preferably about 50 to 300 MPa. The monomer emulsion may be preliminarily emulsified with a disper or the like before emulsification with the machine.

  In addition, the dispersion apparatus to be used is not limited to these, What is necessary is just what can make the average particle diameter of the monomer emulsion obtained by emulsification dispersion 1000 nm or less.

  The average particle size of the monomer emulsion obtained by finely dispersing the monomer mixture (I) in an aqueous medium by the above-mentioned method is not particularly limited, but the transparency, water resistance, and production of the formed coating film are not particularly limited. From the viewpoint of stability and the like, a range of 1000 nm or less, preferably 50 to 700 nm, more preferably 50 to 500 nm is suitable.

  Examples of the method for polymerizing the monomer emulsion include a method in which the finely dispersed monomer emulsion is charged in a reactor equipped with a stirrer, a polymerization initiator is added, and the mixture is heated while stirring.

  The polymerization initiator may be either oil-soluble or water-soluble. Examples of the oil-soluble polymerization initiator include organic peroxides such as benzoyl peroxide, octanoyl peroxide, lauroyl peroxide, and stearoyl peroxide. And azo compounds such as azobisisobutyronitrile and azobis (2,4-dimethylvaleronitrile). Examples of water-soluble initiators include organic compounds such as cumene hydroperoxide, tert-butyl peroxide, tert-butyl peroxylaurate, tert-butyl peroxyisopropyl carbonate, tert-butyl peroxyacetate, and diisopropylbenzene hydroperoxide. Peroxides: azobis (2-methylpropiononitrile), azobis (2-methylbutyronitrile), 4,4′-azobis (4-cyanobutanoic acid), dimethylazobis (2-methylpropionate), azobis [ 2-methyl-N- (2-hydroxyethyl) -propionamide], azo compounds such as azobis {2-methyl-N- [2- (1-hydroxybutyl)]-propionamide}; potassium persulfate, ammonium persulfate , Sodium persulfate, etc. Include sulfate and the like, may be used individually or in combination of two or more. In addition, a reducing agent such as sugar, sodium formaldehyde sulfoxylate, iron complex, sodium sulfite, ascorbate, or longalite may be used in combination with the polymerization initiator as necessary to form a redox polymerization system. Thereby, it becomes easy to accelerate the polymerization rate or to perform polymerization at a low temperature.

  In the present invention, the amount of the polymerization initiator used is preferably in the range of 0.1 to 5% by weight based on the total of components (A) and (B). The addition method of this polymerization initiator can be suitably selected according to the kind and quantity. For example, it may be contained in the mixture (I) or an aqueous medium, or may be added all at once during the polymerization.

  In the present invention, in order to improve the mechanical stability of the particles of the biodegradable resin-containing water dispersion, when the biodegradable resin-containing water dispersion has an acidic group, this is treated with a neutralizing agent. It is desirable to neutralize. The neutralizing agent is not particularly limited as long as it can neutralize acidic groups. For example, sodium hydroxide, potassium hydroxide, trimethylamine, dimethylaminoethanol, 2-methyl-2-amino-1-propanol, Examples include triethylamine and aqueous ammonia. It is desirable to neutralize so that the pH of the biodegradable resin-containing aqueous dispersion after neutralization is about 6.5 to 9.0.

  In the present invention, the mixture (I) containing (A) a biodegradable resin and (B) a polymerizable unsaturated monomer is finely dispersed in an aqueous medium so that the average particle size is 1000 nm or less. A method may be employed in which the monomer component (II) containing the polymerizable unsaturated monomer (D) is added to the dispersion obtained by polymerizing the emulsion to be polymerized.

  In the method of the present invention, the monomer component (II) can be dropped as it is, but it is desirable to disperse the monomer component (II) in an aqueous medium and drop it as a monomer emulsion obtained. In this case, the average particle size of the monomer emulsion is not particularly limited.

  By this method, a biodegradable resin-containing aqueous dispersion in which the outer layer of the dispersion resin including the biodegradable resin (A) is further coated with a (co) polymer layer composed of a polymerizable unsaturated monomer (D). Can be manufactured.

  The polymerizable unsaturated monomer (D) can be used by appropriately selecting one or more compounds from the compounds listed as examples of the polymerizable unsaturated monomer (B).

The present invention is an aqueous resin composition containing the biodegradable resin-containing aqueous dispersion described above.
The aqueous resin composition can further comprise a hydrazine derivative as a crosslinking agent when the dispersion resin contains a carbonyl group. Specific examples of the hydrazine derivative include saturated dicarboxylic acid dihydrazides having 2 to 18 carbon atoms such as oxalic acid dihydrazide, malonic acid dihydrazide, glutaric acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide and the like. Monoolefinic unsaturated dicarboxylic acid dihydrazides such as maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide; phthalic acid dihydrazide, terephthalic acid dihydrazide or isophthalic acid dihydrazide; pyromellitic acid dihydrazide, trihydrazide or tetrahydrazide; nitrilotrihydride Citric acid trihydrazide, 1,2,4-benzenetrihydrazide, ethylenediaminetetraacetic acid tetrahydrazide, 1,4,5,8-naphthoic acid Polyhydrazide obtained by reacting a low polymer having a carboxylic acid lower alkyl ester group with hydrazine or a hydrazine hydrate (hydrazine hydride); a hydrazide group-containing compound such as carbonic dihydrazide; bissemicarbazide; hexamethylene diisocyanate Polyfunctional semicarbazide obtained by excessively reacting N, N-substituted hydrazine such as N, N-dimethylhydrazine or the above-mentioned hydrazide with a diisocyanate such as chlorobenzene or isophorone diisocyanate or a polyisocyanate compound derived therefrom, and the polyisocyanate compound Dihydrazide as exemplified above for the isocyanate group in the reaction product of an active hydrogen compound containing a hydrophilic group such as a polyether and a polyol or a polyethylene glycol monoalkyl ether Excessively reacted with the resulting aqueous polyfunctional semicarbazide; compound having a semicarbazide group, such as a mixture of polyfunctional semicarbazide and aqueous polyfunctional semicarbazide; compound having a hydrazone group such as bis-acetyl-di hydrazone and the like.

  Moreover, the compound which has a functional group which can react with the functional group which exists in the said (A) component and (B) component can also be contained. By mixing a compound having a functional group capable of reacting with the functional group present in the component (A) and the component (B), the water resistance and durability of the formed coating film can be further improved. The compound preferably contains two or more functional groups in one molecule. Examples of such combinations of functional groups include epoxy-amine, epoxy-acid, polyol-isocyanate, carboxyl-metal ion, carboxyl-carbodiimide, carboxyl-oxazoline and the like.

  In the aqueous resin composition, water-soluble or emulsion-type acrylic resin, alkyd resin, silicon resin, fluorine resin, epoxy resin, urethane resin, polyester resin, amino resin, polyethylene glycol, polyvinyl alcohol, etc. Molecules; natural resins such as shellac and rosin; modified resins such as “eclipse cell ace” (trade name, manufactured by Nippon Shokuhin Kako, polysaccharides containing xylose and arabinose obtained from corn seed coat), pigment dispersants, Surfactant, surface conditioner, plasticizer, anti-settling agent, antistatic agent, antibacterial agent, fragrance, UV absorber, UV stabilizer, curing catalyst, dispersant, antifoaming agent, thickener, film-forming aid , Preservatives, antifungal agents, antifreeze agents, pH adjusters, flash last inhibitors, aldehyde scavengers, layered minerals, powder Ku may contain particulate activated carbon, titanium oxide photocatalyst, low pollution agents such as alkylene glycol-modified alkyl silicate, an additive etc. in combination with Tekisen selected.

Aqueous paint composition The aqueous paint composition provided by the present invention comprises the above-mentioned aqueous resin composition.

  The aqueous paint composition may be either a clear paint or an enamel paint.

  When applied as an enamel paint, conventionally known color pigments, glitter pigments, extender pigments, rust preventive pigments, and the like can be blended as the pigment component.

  The coated surface to which the aqueous coating composition is applied can be applied to a conventionally known substrate surface or an old coating surface, and the substrate is not particularly limited. For example, concrete surface, mortar Surface, slate plate, PC plate, ALC plate, cement calcium silicate plate, concrete block surface, inorganic substrate such as wood, stone, organic substrate such as plastic, metal such as iron, aluminum, etc. As the film, there are old coatings such as acrylic resin, acrylic urethane resin, polyurethane resin, fluororesin, silicon acrylic resin, vinyl acetate resin, epoxy resin, alkyd resin, etc. provided on these substrates. Can be mentioned. A water-based or solvent-type undercoat material may be applied to the surface to be coated. If necessary, after applying the undercoat material, the aqueous coating composition can be applied as a topcoat material. On the other hand, after applying the aqueous coating composition of the present invention as an undercoat material, it is also possible to apply a conventionally known aqueous topcoat material.

The water-based coating composition of the present invention may be applied by air spray coating, airless spray coating, electrostatic coating, brush coating, roller coating, lysing gun, universal gun, dipping, roll coater, curtain flow coater, roller curtain coater, or die coater. There is no particular limitation, and it can be appropriately selected according to the use of the substrate. As a drying method, any of heat drying, forced drying, and room temperature drying may be used. In this specification, the drying condition of less than 40 ° C. is room temperature drying, the drying condition of 40 ° C. or more and less than 80 ° C. is forced drying, and the drying condition of 80 ° C. or more is heat drying. Moreover, as an application quantity, it is 50-500 g / m < ² > per time, for example, Preferably it can exist in the range of 80-300 g / m < ² >. Moreover, you may apply repeatedly several times in the range which does not impair the coating-film external appearance.

  Hereinafter, the present invention will be described in more detail with reference to examples. “Parts” and “%” indicate “parts by weight” and “% by weight”.

Production of biodegradable resin-containing aqueous dispersion Example 1
The following components are put in a glass beaker and stirred at 2000 rpm for 15 minutes with a disper to produce a preliminary emulsion, and then the preliminary emulsion is pressurized at 150 MPa with a high-pressure emulsifier that collides the fluids by applying high-pressure energy. By processing, a monomer emulsion having an average particle size of dispersed particles of 250 nm was obtained.
Monomer emulsion composition “CAB-551-0.2” (Note 1) 30 parts methyl methacrylate 36 parts n-butyl acrylate 20.5 parts 2-ethylhexyl acrylate 12 parts methacrylic acid 1.5 parts “Newcol 707SF” (Note 2) 15 parts deionized water 85 parts The above monomer emulsion was then transferred to a glass reaction vessel equipped with a stirrer, reflux condenser, nitrogen gas inlet tube, thermometer and reagent inlet, and the solid content concentration was reduced with deionized water. Dilute to 45%. Thereafter, the temperature was raised to 85 ° C., an aqueous polymerization initiator solution in which 1 part of ammonium persulfate was dissolved in 9.4 parts of deionized water was added to the reaction vessel, and stirred for 3 hours while maintaining the temperature under a nitrogen stream. Thereafter, a polymerization initiator aqueous solution in which 0.3 part of ammonium persulfate was dissolved in 3 parts of deionized water was added, stirred for 1 hour while maintaining the temperature, cooled to 40 ° C., and adjusted to pH with dimethylaminoethanol. The biodegradable resin-containing aqueous dispersion (A-1) having a solid content of 43% and an average particle diameter of the dispersed resin of 245 nm was obtained by adjusting to 8.0.
(Note 1) “CAB-551-0.2”: trade name, manufactured by Eastman Kodak, USA, cellulose acetate butyrate, weight average molecular weight 83000
(Note 2) “Newcol 707SF”: trade name, manufactured by Nippon Emulsifier Co., Ltd., an anionic emulsifier having a polyoxyethylene chain, 30% active ingredient.

Examples 2-14
Except having changed the monomer composition as shown in Table 1, it carried out similarly to Example 1, and obtained biodegradable resin containing water dispersion (A-2)-(A-14).

(Note 3) “CAB-381-0.5”: trade name, manufactured by Eastman Kodak Company, cellulose acetate butyrate, weight average molecular weight 100,000
(Note 4) Fatty acid-modified polymerizable unsaturated monomer Put 280 parts of safflower oil fatty acid and 142 parts of glycidyl methacrylate in a glass reaction vessel equipped with a stirrer, reflux condenser, nitrogen gas inlet tube, thermometer and reagent inlet, The reaction was conducted at 140 ° C. with stirring to obtain a fatty acid-modified polymerizable unsaturated monomer. The reaction between epoxy groups and carboxyl groups was quantified by measuring the amount of residual carboxyl groups. It took about 5 hours to complete the reaction.
(Note 5) “Rikemar PL-012”: trade name, manufactured by Riken Vitamin Co., Ltd., glycerin diacetomonolaurate, plasticizer (Note 6) “TINUVINE 123”: trade name, manufactured by Ciba Specialty Chemicals, Inc. Agent (Note 7) “TINUVINE384-2”: trade name, Ciba Specialty Chemicals, benzotriazole UV absorber (Note 8) “Aqualon HS-10”: trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., anionic reactivity Surfactant.

Example 15
The following components are put in a glass beaker and stirred at 2000 rpm for 15 minutes with a disper to produce a preliminary emulsion, and then the preliminary emulsion is pressurized at 150 MPa with a high-pressure emulsifier that collides the fluids by applying high-pressure energy. By processing, a core monomer emulsion having an average particle size of dispersed particles of 250 nm was obtained.
Monomer emulsion composition for core “CAB-551-0.2” (Note 1) 20 parts methyl methacrylate 28.5 parts n-butyl acrylate 12 parts 2-ethylhexyl acrylate 8 parts methacrylic acid 1.5 parts “Newcol 707SF” (Note) 2) 12 parts deionized water 65 parts The above core monomer emulsion was then transferred to a glass reaction vessel equipped with a stirrer, reflux condenser, nitrogen gas inlet tube, thermometer and reagent inlet and solidified with deionized water. Diluted to a partial concentration of 45%. Thereafter, the temperature was raised to 85 ° C., an aqueous polymerization initiator solution in which 0.8 part of ammonium persulfate was dissolved in 6.6 parts of deionized water was added to the reaction vessel, and the mixture was stirred for 3 hours while maintaining the temperature under a nitrogen stream. And the core part was manufactured.
Next, the following components were put into another glass beaker, stirred at 2000 rpm for 15 minutes with a disper to produce a shell monomer emulsion, and then the shell monomer emulsion and 0.4 parts of ammonium persulfate were maintained while maintaining the temperature. A polymerization initiator aqueous solution in which 2.8 parts of deionized water was dissolved was continuously added dropwise over 1 hour.
Monomer emulsion composition for shell Styrene 10 parts Methyl methacrylate 1.5 parts n-Butyl acrylate 17 parts Methacrylic acid 1.5 parts "Newcol 707SF" (Note 2) 7 parts Deionized water 26 parts After stirring at a temperature for 1 hour, the mixture was cooled to 40 ° C., adjusted to pH 8.0 with dimethylaminoethanol, and a biodegradable resin-containing aqueous dispersion having a solid content concentration of 44% and an average particle size of the dispersed resin of 260 nm (A-15) was obtained.

Comparative Example 1
The following components were put into a glass beaker and stirred at 2000 rpm for 15 minutes with a disper to produce a preliminary emulsion having an average particle size of 8600 nm.
Monomer emulsion composition “CAB-551-0.2” (Note 1) 88 parts methyl methacrylate 4.5 parts n-butyl acrylate 3.5 parts 2-ethylhexyl acrylate 1 part methacrylic acid 3 parts “Newcol 707SF” (Note 2) 15 parts deionized water 85 parts The monomer emulsion was then transferred to a glass reaction vessel equipped with a stirrer, reflux condenser, nitrogen gas inlet tube, thermometer and reagent inlet, and the solid content concentration was 45 with deionized water. The solution was diluted to be%. Thereafter, the temperature was raised to 85 ° C., an aqueous polymerization initiator solution in which 0.2 part of ammonium persulfate was dissolved in 5 parts of deionized water was added to the reaction vessel, and the mixture was stirred for 2 hours while maintaining the temperature under a nitrogen stream. Thereafter, a polymerization initiator aqueous solution in which 0.1 part of ammonium persulfate was dissolved in 3 parts of deionized water was added, stirred for 30 minutes while maintaining the temperature, cooled to 40 ° C., and adjusted to pH with dimethylaminoethanol. Adjusted to 8.0. This aqueous dispersion had very many filtration residues. The average particle diameter of the dispersion resin of the resin dispersion (A-16) in the sample which was sampled and diluted after removing the filtration residue was 1800 nm.

Comparative Example 2
70 parts of toluene was charged into a glass reaction vessel equipped with a stirrer, reflux condenser, nitrogen gas inlet tube, thermometer, and reagent inlet, and the temperature was raised to 100 ° C. A monomer mixture having the following composition prepared in another container was dropped into the reaction container over 4 hours while maintaining the temperature and stirring. After completion of the dropwise addition, the mixture was aged for 1 hour, and a polymerization initiator solution in which 5.0 g of t-butylperoxy-2-ethylhexanoate was dissolved in 1.0 g of toluene was added dropwise over 1 hour, and further aged for 1 hour. . Then, it cooled to 40 degreeC and obtained the acrylic resin.
Monomer mixture composition Methyl methacrylate 44 parts n-butyl acrylate 30 parts 2-ethylhexyl acrylate 21 parts methacrylic acid 5 parts toluene 15 parts t-butylperoxy-2-ethylhexanoate 1.2 parts and then the acrylic resin 20 parts, 80 parts of “CAB-551-0.2” and 270 parts of toluene were charged in a stainless steel container and stirred in a 20 ° C. atmosphere until uniform. Thereafter, while maintaining this temperature, 10 parts of “Newcol 707SF” and 500 g of deionized water were gradually added to carry out phase inversion emulsification. Thereafter, toluene was removed under reduced pressure to obtain an aqueous dispersion (A-17). The weight average molecular weight of the dispersion resin of the aqueous dispersion (A-17) was 35000, and the average particle size was 1300 nm. The storage stability of the aqueous dispersion (A-17) was Δ in the following evaluation.
(* 1) Storage stability 1 kg of the aqueous dispersion shown in Table 1 was placed in an inner-coated can with a capacity of 1 L and stored in a constant temperature room at 40 ° C. for 30 days. Then, it returned to room temperature, the state in a container was observed visually, and the following reference | standard evaluated.
○: Separation is not observed, Δ: Soft caking and separation are observed, but uniform by stirring, ×: Hard caking and separation are observed, and do not return.

Production of aqueous coating composition Example 16
The components shown below were sequentially charged into a container, and stirring was continued until 30 minutes with a disper until it became uniform to obtain a pigment paste for white paint.
Pigment paste composition Water 45 parts "Slaff 72N" (Note 9) 3 parts "BYK-190" (Note 10) 6 parts "JR-605" (Note 11) 100 parts 250 parts of aqueous resin dispersion (A-1), 18 parts of “TEXANOL” (Note 12), 2 parts of “SN Deformer 380” (Note 13), 2 parts of “Adecanol UH-438” (Note 14) It mix | blended and stirred and mixed, and the water-based coating composition (B-1) was obtained.

Examples 17-29 and Comparative Examples 3-4
In Example 16 above, aqueous coating compositions (B-2) to (B-16) were obtained in the same manner as Example 16 except that the formulation was as shown in Table 2 below.

(Note 9) “Sura-off 72N”: trade name, manufactured by Takeda Pharmaceutical Co., Ltd., preservative (Note 10) “BYK-190”: trade name, manufactured by Big Chemie, pigment dispersant (Note 11) “JR-605” ": Trade name, manufactured by Teica, Titanium White (Note 12)" TEXANOL ": Trade name, manufactured by Eastman Chemical Co., 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate, film-forming assistant Agent (Note 13) “SN Deformer 380”: trade name, manufactured by San Nopco, defoaming agent (Note 14) “Adecanol UH438”: trade name, manufactured by Adeka, thickener.

Evaluation test The aqueous coating compositions (B-1) to (B-16) were evaluated according to the following criteria. The results are also shown in Table 2.
(* 2) Appearance of coating film Each aqueous coating composition was coated on a glass plate using a 6 mil doctor blade and dried under conditions of an air temperature of 20 ° C. and a relative humidity of 60% to obtain test coating plates. The appearance of the coating film was visually evaluated after 1 day.
◎: Good, excellent feeling of flesh, ○: Good, △: Slightly poor, X: Defects such as cracks and chijimi (* 3) Gloss 60 of the test coated plate obtained in the same manner as (* 2) above The degree of gloss was measured. The larger the value, the better the gloss.
(* 4) Dryability Each water-based paint composition was coated on a glass plate using a 6 mil doctor blade and dried for 6 hours under conditions of an air temperature of 20 ° C. and a relative humidity of 60%. It investigated and evaluated by the following reference | standard.
◎: Fingerprint is not attached at all, ○: Fingerprint is attached but it returns to its original state after a while, Δ: Fingerprint is attached and it does not return, ×: The coating film is attached to the finger.
(* 5) Water resistance “EP sealer transparent” (manufactured by Kansai Paint Co., Ltd., acrylic emulsion sealer) is brush-coated on a slate plate (70 × 150 × 5 mm) to a coating amount of 150 g / m ² , and the temperature is 20 What was dried for one day under the conditions of ° C. and relative humidity 60% RH was used as a test material. Next, the test material was brushed with each aqueous coating composition so that the coating amount was 100 g / m ^2, and after standing for 4 hours, the same aqueous coating composition was further brushed so that the coating amount was 100 g / m ^2. Then, the test coating plates were obtained by drying for 7 days under conditions of an air temperature of 20 ° C. and a relative humidity of 60%. The state of the coating film after visually immersing each test coating plate in clean water (20 ° C.) for 7 days was visually evaluated.
◎: Good, ○: Slight luster is observed, but practical level, Δ: Gloss, whitening, and blisters are observed, X: Remarkably blisters are observed, or the coating is softened (* 6) After coating “Ares Holder GII” (manufactured by Kansai Paint Co., Ltd., aqueous base preparation) on a cycle test slate plate (70 × 150 × 5 mm) in accordance with the JIS A 6909 repeated heating and cooling test, each aqueous coating composition Was applied with a brush so that the coating amount was 100 g / m ^2, and allowed to stand for 4 hours, and then the same aqueous coating composition was further applied with a brush so that the coating amount was 100 g / m ^2. Each test coated plate was obtained by drying for 7 days under the condition of%. [Dip in water (20 ° C.) for 18 hours to 3 hours in a −20 ° C. incubator for 3 hours to 3 hours in a 50 ° C. incubator] to visually evaluate the coating state after 10 cycles test did.
◎: No cracks, peels, or bulges are observed; ○: No cracks, peels, or bulges are observed, but slight fading is observed; △: Cracks, peels, or bulges are observed; x: Significant cracks or peels (* 7) Accelerated weather resistance According to the accelerated weather resistance test of 9.8.1 (Sunshine carbon arc lamp type) of JIS K 5400 And after irradiating for 1000 hours, the coating-film state was evaluated visually.
A: No cracking, peeling, or blistering was observed, and gloss retention was 70% or more. B: No cracking, peeling, or swelling was observed, and gloss retention was 60% or more. Δ: Cracking, peeling, No swelling is observed and the gloss retention is 50% or less. X: cracking, peeling, and swelling are observed.

Claims (18)

A biodegradable resin containing (A) biodegradable resin and (B) a dispersion resin containing a (co) polymer composed of a polymerizable unsaturated monomer as a constituent unit has an average particle size of 1000 nm or less. Water dispersion. The biodegradable resin-containing aqueous dispersion according to claim 1, wherein the biodegradable resin (A) is one or more compounds selected from the group consisting of cellulose acetate derivatives, chitin and polybutylene succinate. The biodegradable resin-containing aqueous dispersion according to claim 1 or 2, wherein the polymerizable unsaturated monomer (B) contains a polymerizable unsaturated monomer containing a carbonyl group. The biodegradable resin-containing aqueous dispersion according to any one of claims 1 to 3, wherein the polymerizable unsaturated monomer (B) contains a fatty acid-modified polymerizable unsaturated monomer. The theoretical glass transition temperature of the (co) polymer composed of the polymerizable unsaturated monomer (B) is in the range of -20 to 50 ° C, according to any one of claims 1 to 4. Biodegradable resin-containing water dispersion. The biodegradable resin-containing composition according to any one of claims 1 to 5, wherein the (co) polymer comprising the polymerizable unsaturated monomer (B) has a weight average molecular weight of 250,000 or less. Water dispersion. The dispersion resin contains (C) at least one additive selected from the group consisting of a plasticizer, an ultraviolet absorber, an ultraviolet stabilizer, and a metal dryer as a constituent unit. A biodegradable resin-containing water dispersion. A biodegradable resin-containing water having a core / shell structure in which the dispersion resin according to any one of claims 1 to 7 is used as a core and at least one polymer outer shell is used as a shell for the core. Dispersion. (A) A mixture (I) containing a biodegradable resin and (B) a polymerizable unsaturated monomer is finely dispersed in an aqueous medium so that the average particle diameter is 1000 nm or less, and the resulting emulsion is polymerized. A process for producing a biodegradable resin-containing water dispersion characterized by the above. (A) A mixture (I) containing a biodegradable resin and (B) a polymerizable unsaturated monomer is finely dispersed in an aqueous medium so that the average particle diameter is 1000 nm or less, and the resulting emulsion is polymerized. A method for producing a biodegradable resin-containing aqueous dispersion, wherein the monomer component (II) containing a polymerizable unsaturated monomer (D) is added to the dispersion obtained by polymerization to polymerize. The method according to claim 9 or 10, wherein the biodegradable resin (A) is one or more compounds selected from the group consisting of a cellulose acetate derivative, chitin and polybutylene succinate. The method according to any one of claims 9 to 11, wherein the polymerizable unsaturated monomer (B) contains a polymerizable unsaturated monomer containing a carbonyl group. The method according to any one of claims 9 to 12, wherein the polymerizable unsaturated monomer (B) contains a fatty acid-modified polymerizable unsaturated monomer. 14. The mixture (I) according to claim 9, wherein the mixture (I) contains at least one additive (C) selected from the group consisting of a plasticizer, an ultraviolet absorber, an ultraviolet stabilizer, and a metal dryer. Method. An aqueous resin composition containing the biodegradable resin-containing aqueous dispersion according to any one of claims 1 to 8. An aqueous coating composition containing the aqueous resin composition according to claim 15. A method for forming a coating film, comprising applying the aqueous coating composition according to claim 16 to a surface to be coated. The coated article obtained by the coating-film formation method of Claim 17.