JP2768476B2 - Room temperature crosslinking cation emulsion composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cold-crosslinkable cationic emulsion composition.

(Conventional technology and its problems) Conventionally, organic solvent-based paints have been used because of their excellent film-forming properties and coating film performance.

However, the organic solvent type paint is not preferable in terms of environmental conservation and safety because the organic solvent in the paint is volatilized into the air when being painted or dried. For this reason, in recent years, various aqueous emulsions have been developed in the paint industry in place of organic solvent type paints, and are widely used.

The aqueous emulsion forms a coating film by fusing the emulsion particles together with volatilization of water, but the performance of the coating film is not sufficient. For this reason, when higher coating film performance is required, it is common practice to introduce a functional group into the aqueous emulsion and to form a crosslinked coating film using the functional group during drying.

As the aqueous emulsion for forming the crosslinked coating film, a one-part type emulsion in which a crosslinking agent is incorporated in the aqueous emulsion and a two-part type aqueous emulsion in which a crosslinking agent is added before coating have been developed. This method is not generally used because it has disadvantages such as troublesome addition of the crosslinking agent and consideration of the time (pot life) from the addition of the crosslinking agent to coating (pot life).

As a one-pack type aqueous emulsion, a method of crosslinking by a combination of functional groups such as an oxirane group and an amino group or a carbonyl group and a hydrazide group has been used.

In the former aqueous emulsion, the reaction between the oxirane group and the amino group proceeds at room temperature. Therefore, the oxirane group is introduced into the emulsion particles, and the amino group by a cross-linking agent such as polyamine is introduced into the aqueous phase. Is separated in an aqueous system. However, the aqueous emulsion has a drawback that the self-reaction between oxirane groups in the particles and the reaction between the oxirane group and the amino group gradually progress during the long-term storage, resulting in poor long-term storage stability.

In the latter aqueous emulsions, studies have been made and many reports have been made. For example, JP-A-54-144432, JP-A-57-3857, JP-A-58
-96643, JP-A-58-104902, JP-A-61-1
36501 JP, JP-A-62-272742, JP-A-63-1799
No. 10 discloses a copolymer of an unsaturated monomer having a carbonyl group and an unsaturated carboxylic acid (or an amide group-containing monomer) and another monomer, which is an anionic and / or nonionic emulsifier. An aqueous emulsion obtained by adding a hydrazide compound (or a hydrazide-based polymer) to an aqueous emulsion emulsified in (1) is described. In these aqueous emulsions, the emulsion particles are uncharged or negatively charged by an anionic or nonionic emulsifier, the hydrazide compound easily enters the particles, the reaction between the carbonyl group and the hydrazide group gradually progresses, and There is a disadvantage that storage stability deteriorates. Furthermore, since the aqueous emulsion of the publication has a carboxyl group or an amide group derived from an unsaturated carboxylic acid or amide group-containing monomer in the emulsion particles, the hydrazide compound easily enters the emulsion particles, and the emulsion storage stability is low. There is a disadvantage that it gets worse. Also, JP-A-55-147557 and JP-A-55-1475.
No. 62 describes an aqueous emulsion obtained by adding a hydrazide or hydrazone compound to an aqueous emulsion obtained by emulsifying a copolymer of a carbonyl group-containing unsaturated monomer, an unsaturated carboxylic acid and other monomers with an emulsifier. These aqueous emulsions have poor emulsion storage stability because carboxyl groups are present in the emulsion particles as described above. Non-ionic, anionic and cationic surfactants are also disclosed as emulsifiers, but non-ionic and anionic surfactants are substantially used, and these have poor emulsion long-term storage stability. There is a disadvantage that.

(Means for Solving the Problems) The present inventors have intensively studied to solve the problems of the prior art as described above. As a result, using a cationic emulsion obtained by dispersing a carbonyl group-containing radical copolymer having no carboxyl group in water,
They have found that they have excellent long-term storage stability, and have completed the present invention.

That is, the present invention provides a cationic emulsion obtained by dispersing a carbonyl group-containing radical copolymer having no carboxyl group in water, and a storage stability characterized by adding a polyhydrazide compound as a crosslinking agent. The present invention relates to an excellent cold-crosslinkable cationic emulsion composition.

In the composition of the present invention, the cationic emulsion to which a crosslinking agent is added is a carbonyl group-containing unsaturated monomer (A) and other ethylenically unsaturated monomers capable of undergoing a radical copolymerization reaction with the monomer (A). (B) and emulsion polymerization using a cationic surfactant in the presence of a radical initiator.

The carbonyl group-containing unsaturated monomer (A) is a monomer having at least one aldehyde group or keto group and one radically polymerizable double bond in one molecule, that is, a polymerizable monomer. Olefinically unsaturated aldehyde compounds and keto compounds. Representative specific examples include, for example, acrolein, diacetone acrylamide, diacetone methacrylamide, formylstyrene, acrylamide pivalinaldehyde, methacrylamide pivalinaldehyde, 3-acrylamidomethyl-anisaldehyde, diacetone acrylate, acetonyl acrylate, diacetone Examples include methacrylate, 2-hydroxypropyl acrylate acetyl acetate and butanediol acrylate acetyl acetate, vinyl alkyl ketone, and the like. Among the above, keto compounds are preferred.

The monomer (A) is used in an amount of about 0.1 to 40% by weight, preferably about 2 to 30% by weight, more preferably 5 to 20% by weight, based on the total weight of the monomers (A) and (B). At the ratio of If the proportion of the monomer (A) is less than about 0.1% by weight, a sufficiently crosslinked coating film cannot be obtained, while if the proportion of the monomer (A) is more than about 40% by weight, the storage stability of the aqueous emulsion can be reduced. Worse.

The other ethylenically unsaturated monomer (B) is not particularly limited as long as it has a double bond capable of undergoing radical polymerization with the monomer (A). It can be appropriately selected and used. Specifically, for example, (1) methyl acrylate, methyl methacrylate,
Ethyl acrylate, ethyl methacrylate, n-butyl acrylate, n-butyl methacrylate, i-butyl acrylate, i-butyl methacrylate, tert-butyl acrylate, tert-butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl Methacrylic acid, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, decyl acrylate, etc., alkyl or cycloalkyl ester of acrylic acid or methacrylic acid having 1 to 24 carbon atoms; (2) acrylamide, methacrylamide, dimethyl Acrylic or methacrylamide such as acrylamide; (3) styrene, vinyltoluene, propion Vinyl, alpha-methyl styrene, vinyl acetate, acrylonitrile, methacrylonitrile, vinyl propionate, vinyl pivalate, Beobamonoma (Shell Chemicals),
Ethylenically unsaturated monomers such as ethylene, propylene, butylene and pentene; and (4) diene compounds such as butadiene, isoprene and chloroprene.

The above-mentioned monomers (1) to (4) can be used alone or in combination of two or more.

In addition to the above-mentioned monomers (1) to (4), the following cationic vinyl monomers can be used. When the cationic vinyl monomer is used, a barrier layer with a positive charge is formed on the surface of the aqueous emulsion particles, and the approach of a positively charged polyhydrazide compound is prevented, so that the storage stability of the aqueous emulsion is improved. Further, the cationic vinyl monomer is bonded to the particles by a chemical bond, and is stable in the system as compared with the cationic surfactant physically adsorbed to the particles. By using this, an aqueous emulsion having further excellent long-term storage stability can be obtained. However,
Since the cationic vinyl monomer inhibits the reaction between the carbonyl group and the polyhydrazide group, in order to obtain a sufficient cross-linked coating film, the amount of the cationic vinyl monomer is about 10% by weight or less, preferably 5% by weight, based on the total weight of the monomer. % Or less.

As the cationic vinyl monomer, specifically,
Examples include compounds such as dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, dimethylaminopropyl acrylamide, dimethylaminopropyl methacrylamide, and adducts of glycidyl (meth) acrylate and amine.
Further, a salt obtained by neutralizing the cationic group of the above-mentioned cationic vinyl monomer with an acid or a quaternized monomer can also be used.

Further, in addition to the above-mentioned monomers, hydrophilic monomers such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate, and polyethylene glycol (meth) acrylate, depending on the required coating film performance. And the like can be used in combination with the above monomers.

The radical polymerization initiator used for the copolymerization reaction between the monomer (A) and the monomer (B) can be used without any particular limitation. Specifically, for example, 1- [1-
Cyano-methylethyl) azo] formamide, 2,2'-
Azo initiators such as azobis {2-methyl-N- [1,1-bis (hydroxymethyl) ethyl] propionamide}, azobisisobutyronitrile, etc .; hydrogen peroxide, te
Nonionic initiators such as peroxide initiators such as rt-butyl hydroperoxide and cumene hydroperoxide; 2,2'-azobis (2-methylpropionamidine) dihydrochloride, 2,2'-azobis [2-
(5-methyl-2-imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2-
(2-Imidazolin-2-yl) propane] dihydrochloride, 2,2'-azobis [2- (4,5,6,7-tetrahydro-1H-1,3-diazepin-2-yl) propane] A cationic azo initiator such as dihydrochloride can be suitably used.

As the cationic surfactant used when the monomer (A) and the monomer (B) are copolymerized, a conventionally known cationic surfactant can be used. Specifically, for example, octadecyltrimethylammonium chloride, dodecyltrimethylammonium chloride, hexadecyltrimethylammonium chloride, dioctadecyldimethylammonium chloride, didodecylmethylammonium chloride, dodecylbenzyldimethylammonium chloride, tetradecylbenzyldimethylammonium chloride, octadecylbenzyldimethyl Ammonium chloride, tetradecyltrimethylammonium chloride, dihexadecyldimethylammonium chloride, dioctadecyldimethylammonium chloride, hexadecylbenzyldimethylammonium chloride, palmityltrimethylammonium chloride, oleyltrimethylammonium chloride, Palmityl benzyltrimethylammonium chloride,
Dioleylbenzyltrimethylammonium chloride, decyl ammonium methyl sulfate, N-ethyldodecyl ammonium bromide, cetyl ammonium bromide, N,
N-dimethyl dodecyl ammonium, N, N-dimethyl stearyl ammonium chloride, lauryl pyridinium chloride, polyoxyethylene dodecylamine, polyoxyethylene hexadecylamine, polyoxyethylene octadecylamine, dodecylamine acetate, tetradodecylamine acetate, octadecylamine Examples include compounds such as acetate, dodecylamine hydrochloride, tetradecylamine hydrochloride, octadecylamine hydrochloride, and hardened tallowamine acetate. In addition to the above, a cationic polymer or a cationic polyvinyl alcohol containing the cationic vinyl monomer as an essential component, a reactive emulsifier, and the like can also be used. The above-mentioned cationic surfactants can be used alone or in combination of two or more. Further, the cationic surfactant and a nonionic surfactant described below can be used in combination.

From the viewpoint of storage stability of the aqueous emulsion and curability of the coating film, the mixing ratio of the cationic surfactant is preferably about 0.1 to 100 parts by weight in total with the monomers (A) and (B). -10 parts by weight, preferably about 0.5-5 parts by weight.

Emulsion polymerization using the monomer, initiator and cationic surfactant can be carried out by a conventionally known emulsion polymerization method.

Further, the cationic emulsion used in the composition of the present invention may further comprise, for example, (1) an essential monomer comprising the carbonyl group-containing unsaturated monomer (A) and the cationic vinyl monomer. (2) the carbonyl group-containing unsaturated monomer, wherein the monomer as a component is polymerized in the presence of the nonionic radical initiator, or further polymerized using a cation and / or a nonionic surfactant. (A)
And the other ethylenically unsaturated monomer (B) are polymerized in the presence of an initiator having a cationic initiator as an essential component, or are further polymerized using a nonionic surfactant. Things can also be used.

Examples of the nonionic surfactant include polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether and polyoxyethylene lauryl ether; and polyoxyethylene alkyl phenyl ethers such as polyoxyethylene nonyl phenyl ether and polyoxyethylene octyl phenyl ether. Polyoxyethylene alkyl esters such as polyoxyethylene monolaurate and polyoxyethylene monostearate; sorbitan esters such as sorbitan monolaurate and sorbitan monostearate; sorbitan ester ethers such as polyoxyethylene sorbitan monolaurate; Polyoxyethylene oxypropylene block polymer, polyethylene glycol and the like can be mentioned.

Further, an amphoteric surfactant such as dimethylalkyl betaine, lauryl betaine, and stearyl betaine can be used in combination.

These polymerizations can be carried out according to a conventionally known polymerization method.

In the composition of the present invention, the polyhydrazide compound as a crosslinking agent to be added to the cationic emulsion contains a hydrazide group in one molecule. Can be used without any particular limitation as long as it has two or more. Specifically, aliphatic carboxylic acid dihydrazides having 2 to 40 carbon atoms such as oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, eicosane diacid dihydrazide and the like; Polyhydrazides such as carbonic dihydrazide and the general formula (Where x represents a number of 1 to 5, preferably 1 to 3); bissemicarbazide, particularly of the general formula (Wherein the group -R- is a linear or branched aliphatic residue having 2 to 7 carbon atoms or a carbocyclic residue having 6 to 8 carbon atoms, for example, o-, m- or aliphatic, alicyclic or aromatic bissemicarbazide represented by p-phenylene group, toluylene group, cyclohexylidene group or methylcyclohexylidene group); polyhydrazide of aromatic polycarboxylic acid, for example, phthalic acid Dihydrazide of terephthalic acid or isophthalic acid, and dihydrazide, trihydrazide or tetrahydrazide of pyromellitic acid; at least two, often in one molecule
Polyhydrazide of polyacrylic acid having 20 to 100 hydrazide groups; trihydrazide such as nitrilotriacetic trihydrazide or tetrahydrazide such as ethylenediaminetetraacetic acid tetrahydrazide;

Examples of the hydrazide used include the following. Di- or trihydrazine-triazine, thiocarbohydrazide or N, N'-diaminoguanidine, and hydrazine-pyridine derivatives such as 2
-Hydrazinopyridine-5-carboxylic acid hydrazide, 3
-Chloro-2-hydrazinopyridine-5-carboxylic acid hydrazide, 6-chloro-2-hydrazinopyridine-4-
Carboxylic acid hydrazide or 2,5-dihydrazinopyridine-4-carboxylic acid and the like and bis-thiosemicarbazide,
And bishydrazine of alkylene bisacrylamide, hydrazine alkane and dihydrazine of aromatic hydrocarbon such as 1,4-dihydrazinobenzol, 1,3-dihydrazinobenzol, 2,3-dihydrazinenaphthalene,
And dihydrazides of monoolefinically unsaturated dicarboxylic acids, such as maleic dihydrazide, fumaric dihydrazide and itaconic dihydrazide.

As the polyhydrazide compound, if the hydrophilicity itself is too strong, the emulsion storage stability is poor.On the other hand, if the hydrophobicity is too strong, it is difficult to disperse in water, and a uniform crosslinked coating film cannot be obtained. It is preferable to use a compound having a relatively low molecular weight (about 300 or less) having high hydrophilicity. One of the preferred representative examples is C _4-12 such as succinic dihydrazide, glutaric dihydrazide, adipic dihydrazide, sebacic dihydrazide and the like.
Dicarboxylic acid dihydrazide compound.

The amount of the polyhydrazide compound to be added is determined by the ratio of the hydrazide group in the polyhydrazide compound to the number of carbonyl groups / the number of hydrazide groups with respect to the carbonyl groups in the aqueous emulsion.
1/10 to 100/1, preferably 1/1 to 10/1, more preferably
It can be blended to be 3/1 to 1/2.

Although the composition of the present invention can obtain a crosslinked coating film by drying at room temperature, it can also be heated if necessary.

The composition of the present invention, a pigment, a dye, an organic solvent, a plasticizer,
Preservatives, coating surface adjusters and the like can be added as required.

The composition of the present invention is useful for paints, lining materials, sealing materials, textile processing, adhesives and the like.

(Actions and Effects) As described above, in the composition of the present invention, since the emulsion particles are positively charged in the system and repel the positively charged hydrazide compound in the aqueous dispersion medium layer, the hydrazide compound is contained in the emulsion particles. Therefore, a property excellent in long-term storage stability can be exhibited.

(Examples) Next, the present invention will be described in more detail with reference to examples.
“Parts” and “%” in Production Examples are based on weight.

Production Examples of Aqueous Emulsions A to H Production Example 12 The following are placed in a two-flask.

170 parts of deionized water V-50 (manufactured by Wako Pure Chemical Industries, Ltd., trade name, 2,2'-A
zobis (2-methylpropionamidin) dihydrochloride,
Hereinafter, the same meaning is used. 0.6 parts Separately mix the following ingredients to make a pre-emulsion.

Deionized water 340 parts Coatamine 86P Conc (manufactured by Kao Corporation, trade name, stearyltrimethylammonium chloride) 23 parts V-50 3.5 parts Styrene 150 parts 2-ethylhexyl acrylate 300 parts Diacetone acrylamide 50 parts The contents of the two flasks are 80 After heating to <RTIgt; C, </ RTI> the pre-emulsion is added dropwise over 2-3 hours to effect emulsion polymerization. Thirty minutes after the completion of the dropwise addition, for 30 minutes, 0.5 part of V-50 dissolved in 10 parts of deionized water is added. Further, after aging at the same temperature for 30 minutes, the emulsion was cooled to obtain an emulsion A. The properties of the emulsion A are shown in Table 1.

Production Example 2 The following were placed in a 2 flask.

170 parts of deionized water V-50 0.6 parts Separately mix the following ingredients to make a pre-emulsion.

Deionized water 340 parts Coatamine 86P Conch 15 parts Inogen EA130T (manufactured by Daiichi Kogyo Co., Ltd., trade name, polyoxyethylene nonylphenyl ether) 10 parts V-50 3.5 parts Styrene 150 parts 2-ethylhexyl acrylate 300 parts Diacetone acrylamide 50 parts The above composition was synthesized in the same manner as in Production Example 1 to obtain Emulsion B. The properties of the emulsion B are shown in Table 1.

Production Example 3 The following were placed in a 2 flask.

170 parts of deionized water V-50 0.6 parts Separately mix the following ingredients to make a pre-emulsion.

Deionized water 435.7 parts Coatamine 86P conc 23 parts V-50 3.5 parts Styrene 95 parts 2-ethylhexyl acrylate 370 parts Diacetone acrylamide 25 parts Dimethylaminopropyl acrylamide 10 parts The above compound was synthesized in the same manner as in Production Example 1. The emulsion C was obtained. The properties of the emulsion C are shown in Table 1.

Preparation 4 The following were placed in the flask of Example 2.

170 parts of deionized water V-50 0.6 parts Separately mix the following ingredients to make a pre-emulsion.

Deionized water 340 parts Coatamine 86P conc 23 parts V-50 3.5 parts Styrene 150 parts 2-ethylhexyl acrylate 325 parts Diacetone acrylamide 25 parts Emulsion D is obtained by synthesizing the above compound in the same manner as in Production Example 1. Was. Table 1 shows the properties of the emulsion D.

The following were added to the flask of Preparation Example 52:

170 parts of deionized water V-50 0.6 parts Separately mix the following ingredients to make a pre-emulsion.

Deionized water 340 parts Coatamine 86P conc 23 parts V-50 3.5 parts Styrene 150 parts 2-Ethylhexyl acrylate 250 parts Diacetone acrylamide 100 parts Emulsion E is obtained by synthesizing the above compound in the same manner as in Production Example 1. Was. The properties of the emulsion E are shown in Table 1.

Preparation 6 The following were added to the flask of 2:

200 parts of deionized water Separately mix the following ingredients to make a pre-emulsion.

Deionized water 285 parts Levenol WZ (manufactured by Kao Corporation, trade name, sodium polyoxyethylene alkyl phenyl ether sulfate) 58 parts Ammonium persulfate 2.5 parts Styrene 150 parts 2-ethylhexyl acrylate 300 parts Diacetone acrylamide 50 parts Ammonium persulfate as an additional catalyst Emulsion F was obtained in the same manner as in Production Example 1, except that 0.5 part of the polymer was dissolved in 10 parts of deionized water. Table 1 shows the properties of the emulsion F.

Preparation 7 The following are added to the flask of Example 2:

200 parts of deionized water Separately mix the following ingredients to make a pre-emulsion.

Deionized water 285 parts Emal 2F needle (manufactured by Kao Corporation, trade name, sodium lauryl sulfate) 19 parts Ammonium persulfate 2.5 parts Styrene 150 parts 2-Ethylhexyl acrylate 300 parts Diacetone acrylamide 50 parts Emulsion G was obtained by performing synthesis in the same manner. The properties of the emulsion G are shown in Table 1.

Preparation 8 The following were added to the flask of 2:

200 parts of deionized water Separately mix the following ingredients to make a pre-emulsion.

Deionized water 285 parts Levenol WZ 50 parts Ammonium persulfate 2.5 parts Styrene 90 parts 2-Ethylhexyl acrylate 340 parts Diacetone acrylamide 50 parts Acrylic acid 10 parts Acrylamide 10 parts Emulsion H is obtained by performing synthesis in the same manner as in Production Example 6. Was. The characteristics are shown in Table 1.

Production Examples of Crosslinking Agents X and Y Production Example 1 174.2 parts of dimethyl adipate 100.1 parts of hydrazine (monohydrate) 224 parts of deionized water are placed in a 2 flask and heated to 80 ° C. The reaction was continued at the same temperature for 10 hours to obtain a crosslinking agent X. The crosslinking agent turns into a white solid crystal in water at room temperature, but turns into a homogeneous aqueous solution when heated.

Production Example 2 Dimethyl malonate 139 parts Hydrazine (monohydrate) 105 parts Deionized water 332 parts were placed in a flask 2 and heated at 80 ° C. for 7 hours to obtain a crosslinking agent Y. The crosslinking agent turns into a white solid crystal in water at room temperature, but turns into a homogeneous aqueous solution when heated.

A water dilution of the clear emulsion is measured with a spectrophotometer, and the absorbance ratio is calculated from the following equation [Bull.
trial.Chemical.Research VoL.42 P145-152 (1964)]
The average particle diameter was determined by the calibration curve described in (1).

Examples and Comparative Examples Crosslinkers X and Y were added to the emulsions A to H obtained in the Production Examples.
The aqueous emulsions of Examples 1 to 10 and Comparative Examples 1 to 6 were obtained by mixing so that the compounding ratio of the carbonyl group and the hydrazide group, etc., was equivalent in the combination of the two.

Table 2 summarizes the storage stability and the properties of the crosslinked coating film.

Continuation of the front page (56) References JP-A-55-147557 (JP, A) JP-A-57-3857 (JP, A) JP-A-63-179910 (JP, A) JP-A-64-20256 (JP) JP-A-64-33110 (JP, A) JP-B-61-6681 (JP, B2) (58) Fields investigated (Int. Cl. ⁶ , DB name) C09D 201/00-201/10 C08L 101/00-101/14

Claims (1)

(57) [Claims] 1. A storage stability characterized by adding a polyhydrazide compound as a crosslinking agent to a cationic emulsion obtained by dispersing a carbonyl group-containing radical copolymer having no carboxyl group in water. Excellent cold-crosslinkable cationic emulsion composition.