JPH04252276A - Cationically charged polymer particles, method for producing the same, and electrodeposition paint containing the particles - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to cationically charged polymer particles which are blended into electrodeposition paints as a matting agent and suitably used to form a matte electrodeposition coating film, and a method for producing the same. The present invention relates to an electrodeposition paint containing particles.

0002

BACKGROUND OF THE INVENTION Water-based paints in which charged resins are dispersed in water are generally used as electrodeposition paints for electrodeposition coatings.

On the other hand, a polymer microgel (internally crosslinked resin fine particles) obtained by polymerizing a radically polymerizable α,β-unsaturated ethylenic monomer can be added as a matting agent to such electrodeposition paints. It has been known.

[0004] However, since this microgel does not have the charge necessary for electrodeposition, it does not exhibit co-advancement due to electrophoresis during electrodeposition, unlike charged resin particles, and therefore electrodeposition paints containing such microgels Bath management is difficult and it is difficult to obtain a well-finished coating film.

[0005] Therefore, in order to solve this problem and obtain a one-coat matte electrodeposition paint consisting solely of a charged polymer microgel, an aminated resin such as an aminated product of epoxidized polybutadiene containing α,β ethylenic groups was used. A paint containing a dispersion of cationic crosslinked resin particles obtained by polymerizing a resin having two or more polymerizable vinyl groups in one molecule, such as an epoxy acrylate resin, has been proposed (Japanese Patent Laid-Open No. 2-103273). Publication No.).

[0006]

[Problems to be Solved by the Invention] However, the above-mentioned cationic cross-linked resin particles are used by neutralizing the above-mentioned aminated resin with a neutralizing agent (organic acid) during production. According to the amine value 20-150mgKOH/
When the α,β ethylenic group-containing aminated resin of g was neutralized and diluted with a neutralizing agent, the microgelation reaction could not be carried out at a solid content of 30 to 70% due to the high viscosity. In order to avoid this point, when diluting with a solvent, the viscosity can be lowered, but there is a problem that it becomes difficult to form micelles.

[0007] The present invention has been made in view of the above circumstances.
Cationically charged particles that have excellent properties as a matting agent for electrodeposition coatings, and cationically charged polymer particles that do not have the disadvantages mentioned above, easily undergo microgelation, and have such excellent properties can be easily and easily produced. The object of the present invention is to provide a method for producing the particles that can be reliably obtained and an electrodeposition coating that provides excellent properties such as matting properties, weather resistance, and adhesion by blending the particles.

[0008]

[Means and effects for solving the problem] As a result of intensive studies to achieve the above object, the inventors of the present invention found that (A) a resin obtained by aminating an epoxidized polybutadiene resin is used as a main component; α for 1 equivalent of epoxy group in
contains at least 0.5 equivalents of β-unsaturated ethylenic groups;
and a cationic water-soluble resin having an acid value of 0 to 20 mgKOH/g and an amine value of 20 to 150 mgKOH/g, more preferably a cationic water-soluble resin having an epoxy equivalent of (B) 50 to 5.
000 bisphenol A-type glycidyl compound combined with an epoxy compound in which 0.5 to 1 equivalent of a carboxylic acid having an α, β unsaturated ethylenic group is added to 1 equivalent of the epoxy group in 1 molecule of the resin. On the other hand, when an α,β unsaturated ethylenic monomer is added, the mixture is poured into water in the presence of a surfactant to form micelles, and this is radically polymerized, the α,β unsaturated The saturated ethylenic monomer acts as a reactive diluent, lowering the viscosity of the cationic water-soluble resin and allowing the microgelation reaction to occur, and in this case, the cationic water-soluble resin is neutralized with an organic acid. It is used without harmony, and
Micelle formation is easy, the radical polymerization reaction (microgelation reaction) progresses reliably and easily, and the use of the cationic water-soluble resin (α, β ethylenic group) using α, β unsaturated ethylenic monomer It was discovered that the particle size of cationically charged polymer particles (microgel) could be controlled by modifying the properties of the aminated resin (containing aminated resin) and controlling the amount of surfactant used during micellization. The obtained microgel with an average particle size of 0.1 to 5 μm can be used alone or mixed with a water-soluble resin as a matting agent for one-coat matte electrodeposition paint, and in particular,
In addition to giving the coating film excellent matte properties and forming a coating film with excellent weather resistance, this microgel can also be electrodeposited on its own, and since the microgel particles contain OH groups, it can be used with melamine resins, etc. It has been discovered that it can chemically bond with a known crosslinking agent used in electrodeposition paints such as blocked isocyanate, and thus becomes a constituent element of a coating film and provides a coating film with excellent adhesion. This is what we have come to.

Therefore, the present invention has (A) a resin obtained by aminating an epoxidized polybutadiene resin as a main component, and has at least 0 α,β unsaturated ethylenic groups per equivalent of epoxy group in one molecule of the resin. .5 equivalent, and has an acid value of 0 to 20 mgKOH/g and an amine value of 20 to 15.
A cationic water-soluble resin having a concentration of 0 mg KOH/g, more preferably this (A), and (B) an epoxy equivalent of 200 to
5000 bisphenol A-type glycidyl compound, an epoxy compound in which 0.5 to 1 equivalent of a carboxylic acid having an α, β unsaturated ethylenic group is added to 1 equivalent of the epoxy group in 1 molecule of the resin, and further, (C) The average particle size obtained by radical polymerizing micelles of a mixture of α,β unsaturated ethylenic monomers is 0.1 to
The cationically charged polymer particles of 5 μm and the above mixture are put into water in the presence of a surfactant to form micelles of the above mixture, and then radical polymerized in the presence of a polymerization initiator to form cationically charged polymers. The present invention provides a method for producing cationically charged polymer particles, which is characterized by obtaining a cationically charged polymer dispersion in which particles are dispersed in water, and an electrodeposition paint containing the above cationically charged polymer particles.

[0010] The present invention will be explained in more detail below. The cationically charged polymer particles (microgel) of the present invention
is formed from a cationic water-soluble resin, preferably an epoxy compound, and an α,β-unsaturated ethylenic monomer, as described above, but the cationic water-soluble resin is an aminated epoxidized polybutadiene resin. resin as the main component, at least 0.5 equivalent of α, β unsaturated ethylenic group per equivalent of epoxy group in one molecule of the resin,
It preferably contains 0.5 to 1 equivalent and has an acid value of 0 to 20.
, preferably 0 to 10 mgKOH/g, and an amine value of 20 to 150, preferably 50 to 100 mgKOH/g.
g is used. This epoxidized polybutadiene resin is produced by a known method, but it is preferable to use one having a number average molecular weight of 700 to 30,000, particularly 1,000 to 10,000. In addition, the amines used for amination include monomethylamine, monoethylamine, dimethylamine, diethylamine, diisopropylamine, N-methylethanolamine, N-methylethanolamine, and N-methylethanolamine.
- Ethylmethanolamine, diethanolamine, etc. are preferably used, and compounds having α,β unsaturated ethylenic groups that are used to contain α,β unsaturated ethylenic groups include acrylic acid, methacrylic acid, α, β unsaturated carboxylic acids such as itaconic acid and crotonic acid, and
α, β unsaturated ethylenic monomers having OH groups, such as half esters of 2-hydroxyethyl acrylate and maleic anhydride, half esters of 2-hydroxyethyl methacrylate and maleic anhydride, and dibasic acids. Examples include compounds obtained by half ester reaction of anhydrides. Note that known methods can also be used for amination and introduction of α, β unsaturated ethylenic groups.

On the other hand, as an epoxy compound, a bisphenol A type glycidyl compound having an epoxy equivalent of 200 to 5,000 is added with 0 carboxylic acid having an α,β unsaturated ethylenic group per equivalent of the epoxy group in one molecule of the resin. .5
~1 equivalent of added epoxy compound is used.

[0012] The carboxylic acids having an α,β unsaturated ethylenic group used in this case include α,β unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, crotonic acid, and acrylic acid- α, β unsaturated ethylenic monomers having OH groups, such as half esters of 2-hydroxyethyl and maleic anhydride, half esters of 2-hydroxyethyl methacrylate and maleic anhydride, and dibasic acid anhydrides. Compounds subjected to half ester reaction are preferably used. Known methods can also be used for the reaction between these carboxylic acids and bisphenol A glycidyl compounds. The epoxy compound preferably has a molecular weight of 400 to 10,000.

The mixing ratio of the cationic water-soluble resin as the component (A) and the epoxy compound as the component (B) is selected as appropriate, but for 100 parts (parts by weight, the same applies hereinafter) of the component (A), (
The amount of component B) is preferably 0 to 400 parts, particularly 0 to 100 parts.

The α,β-unsaturated ethylenic monomer of component (C) to be mixed with these components (A) and (B) includes ethyl acrylate, methyl acrylate, butyl acrylate, and acrylic acid-2- Acrylic esters such as hydroxyethyl, ethylhexyl acrylate, ethyl methacrylate, methyl methacrylate, butyl methacrylate,
Examples include methacrylic acid esters such as 2-hydroxyethyl methacrylate and ethylhexyl methacrylate, styrene and its derivatives, and α,β unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, and crotonic acid. One of these can be used alone or in combination of two or more, and the amount used is 50 to 300 parts per 100 parts of the mixture of components (A) and (B).
In particular, it is preferably 50 to 200 parts. If the amount of component (C) used is less than 50 parts, improvements in weather resistance etc. will not be sufficient, and if it is more than 300 parts, corrosion resistance will deteriorate.

[0015] When obtaining a microgel using the above components (A), (B), and (C), first, these components (A), (B), and
, (C) into water in the presence of a surfactant to prepare micelles from the mixture.

In this case, as the surfactant, one or more of polyoxyethylene nonionic surfactants and fluorine-containing surfactants having an HLB value of 5 to 15 are preferably used. In addition, the amount used is shown in (A) and (B) above.
, (C) The amount is preferably 5 to 25 parts based on 100 parts of the total amount of components.

Next, microgels or internally crosslinked particles are obtained by radical polymerizing the micelles in the presence of a polymerization initiator such as benzoyl peroxide, acetyl peroxide, azobisisobutylnitrile, or potassium peroxosulfate. be. Although the radical polymerization reaction conditions are appropriately selected, the reaction is usually carried out at a temperature of 50 to 100°C for 1 to 10 hours.

The microgel (internally crosslinked particles) obtained by the above method is dispersed in water, and in the present invention, this dispersion can be used as it is as a matting agent for electrodeposition coating. In this case, the solid content of the dispersion is 30
It is preferable to set it to 70% (weight%, same below). The average particle size of the microgel is 0.1 to 5 μm.
, more preferably 0.2 to 2 μm,
When it is smaller than 0.1 μm, there is no matting effect, and when it is larger than 5 μm, the coating film becomes rough.

The properties of the microgel dispersion are as follows: solid content: 3
0-70%, pH 4-7, conductivity 500-3000
It has a viscosity of 10 to 500 cps, and does not dissolve in polar solvents such as tetrahydrofuron and acetone, which are dissolved before polymerization, and becomes cloudy after polymerization.

[0020] The above microgel can be used as a matting agent for electrodeposition paints as described above. in this case,
The microgel can be electrodeposited alone or can be used in combination with other crosslinking agents, but the amount of this microgel in the paint should be 50% or less, especially 10 to 30%. preferable. The electrodeposition paint to which this microgel is added is preferably a cationic electrodeposition paint, and can be suitably used for any cationic electrodeposition paint such as epoxy resin, acrylic resin, and modified resins thereof. can.

[0021]

Effects of the Invention The cationically charged polymer particles (microgel) of the present invention can be used as a matting agent for electrodeposition coating to provide a coating film having excellent matting properties, weather resistance, and adhesion. Moreover, according to this method for producing cationically charged polymer particles, such particles can be produced easily and reliably. Further, the electrodeposition coating material containing the cationically charged polymer particles is easy to control in the bath and provides a coating film having excellent matting properties, weather resistance, and adhesion as described above.

[0022]

[Examples] The present invention will be specifically explained below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example, Comparative Example I] Production of cationic water-soluble resin A (1) Epoxidized polybutadiene resin (Polybutadiene E-1800-6.5 manufactured by Nisseki Chemical Co., Ltd., number average molecular weight 18
00, oxirane oxygen concentration 6.7%) and 200 g of ethyl cellosolve were placed in a 3 liter 5-necked flask equipped with a reflux device, and then diisopropanolamine 2
66g was added and reacted at 140°C for 7 hours.

Next, after cooling to 50°C, acrylic acid 1
08 g and 10 g of hydroquinone were added and reacted at 120°C until the acid value became 5 mgKOH/g or less to obtain a cationic water-soluble resin (hereinafter referred to as resin A-1) having the following properties. Properties of resin A-1 Solid content 87% Amine value 82 mmol/g acid value
3mgKOH/g

(2)
In the same manner as above, 210 g of diethanolamine was added to 1000 g of the same epoxidized polybutadiene resin and 200 g of ethyl cellosolve, reacted at 180°C for 7 hours, cooled to 50°C, added 108 g of acrylic acid and 10 g of hydroquinone, and The reaction was carried out at 0.degree. C. to obtain a cationic water-soluble resin (hereinafter referred to as resin A-2) having the following properties. Properties of resin A-2 Solid content 70% Amine value 82 mmol/g acid value
3mgKOH/g

Production of epoxy compound B (1) 1000 g of a glycidyl compound of bisphenol A having an epoxy equivalent of 200, 100 g of ethyl cellosolve, 360 g of acrylic acid and 36 g of hydroquinone were placed in a 3 liter 5-necked flask equipped with a reflux device, and heated at 80°C. The reaction was carried out until the acid value became 5 mgKOH/g or less to obtain an epoxy compound (hereinafter referred to as compound B-1) having the following properties. Properties of compound B-1 Solid content 90% Acid value 4mgKOH/g

00
27] (2) In the same manner as above, the epoxy equivalent is 95
After completely dissolving 100 g of ethyl cellosolve in 1000 g of glycidyl compound of bisphenol A at 100°C, it was cooled to 50°C, 75 g of acrylic acid and 7.5 g of hydroquinone were mixed, and then reacted at 120°C to obtain the following properties. Epoxy compound (hereinafter referred to as compound B-2)
I got it. Properties of compound B-2 Solid content 78% Acid value 4mgKOH/g

00
28] Production of microgel (1) Using the components shown in Table 1, a microgel (cationically charged polymer particles) was produced by the following method.

20 g of alkyldiphenyl ether disulfonate as an activator, and resins A-1, A-2,
100 g of a mixture of compounds B-1, B-2, styrene, methyl methacrylate, butyl acrylate, 2-hydroxyethyl methacrylate and 100 g of deionized water were added to a 1 liter four-wheeler equipped with a stirring funnel and a dropping funnel and a cooling tube.
The mixture was placed in a neck flask, nitrogen gas was introduced, and the mixture was heated to 80° C., and then a mixture of 10 g of the above activator, 200 g of the mixture, and 1 g of a polymerization initiator (potassium peroxodisulfate) was added dropwise over 100 minutes. Thereafter, 2 g of a polymerization initiator was added and reacted completely to obtain microgels having an average particle size of 0.1 to 5 μm (Examples 1 to 6).

For comparison, a microgel was obtained in the same manner as above except that resins A-1 and A-2 and mixtures B-1 and B-2 were not used (Comparative Example 1). In addition, in the formulation of Example 1, when resin A-1 was neutralized with 1 g of acetic acid and used, microgel was not generated but gelatinized.

(2) The total amount of activator is 10g, 50g, 1
Microgels (Example 7, Comparative Examples 2 and 3) were produced in the same manner as above except that the amount was 00 g. In this case, 10 g of activator was initially charged into the flask and the remaining amount was mixed into the dropping mixture.

[0032]

[Table 1]

[Example, Comparative Example II] 100 parts of the microgel obtained in Example and Comparative Example I was added to 200 g of an epoxy resin-based aqueous cationic electrodeposition paint (New Peyton Black ER, manufactured by Uemura Kogyo Co., Ltd., solid content 40%). The mixture was mixed and water was added to adjust the solid content to 10%. Next, electrodeposition coating was performed using the zinc phosphate chemical conversion treated board under the following conditions. When painting with a coating thickness of 10μm, applied voltage: 70V, current application time: 3 separation temperature: 28±1°C, coating thickness: 20μm
In the case of coating, the applied voltage was 120V, the current application time was 3, the liquid separation temperature was 28±1°C, and the weather resistance, SST, adhesion, and appearance of the resulting coating film were evaluated using the following methods. The results are shown in Table 2. Evaluation of weather resistance of coating film A Sunshine Weather-Ometer (manufactured by Suga Test Instruments) was used, and a gloss retention rate of 80% or higher was considered to be a pass. The salt spray test (SST) evaluation method is based on JIS-K5400. A cross cut within 3 mm on one side was considered acceptable. Adhesion evaluation cross cut (1mm) 90/100 or better, 90
/100 or less was considered defective. Appearance evaluation: Judging by visual inspection. 60° gloss was measured with SZS-Σ80 (manufactured by Nippon Denshoku Kogyo Co., Ltd.).

[0034]

[Table 2]

[Example, Comparative Example III] 100 parts of the microgel obtained in Example and Comparative Example I was mixed into an acrylic resin-based aqueous cationic electrodeposition paint (New Peyton Clear A-7X, Uemura Industries Co., Ltd., solid content 70%). The solid content was adjusted to 10% by adding water to the mixture. Next, electrodeposition coating was performed using the zinc phosphate chemical conversion treated board under the following conditions. When painting with a coating thickness of 10μm, applied voltage: 70V, current application time: 3 separation temperature: 28±1°C, coating thickness: 20μm
In the case of coating, the applied voltage was 120V, the current application time was 3, the liquid separation temperature was 28±1°C, and the weather resistance, SST, adhesion, and appearance of the resulting coating film were evaluated using the methods described above. The results are shown in Table 3.

[0036]

[Table 3]

Claims (5)

[Claims] Claim 1: (A) The main component is a resin obtained by aminating an epoxidized polybutadiene resin, and contains at least 0.5 equivalents of α, β unsaturated ethylenic groups per equivalent of epoxy group in one molecule of the resin. and has an acid value of 0 to 20 mgK.
OH/g, and the amine value is 20 to 150 mgKOH/
The average particle size obtained by radical polymerizing micelles of a mixture of the cationic water-soluble resin (g) and the α,β unsaturated ethylenic monomer (C) is 0.1 to 5 μm.
cationically charged polymer particles. [Claim 2] (A) The main component is a resin obtained by aminating an epoxidized polybutadiene resin, and contains at least 0.5 equivalents of α, β unsaturated ethylenic groups per equivalent of epoxy group in one molecule of the resin. and has an acid value of 0 to 20 mgK.
OH/g, and the amine value is 20 to 150 mgKOH/
g, and (B) a bisphenol A type glycidyl compound having an epoxy equivalent of 200 to 5,000, α,
0.5 to 1 carboxylic acid having β-unsaturated ethylenic group
Cationically charged polymer particles having an average particle size of 0.1 to 5 μm obtained by radical polymerizing micelles of a mixture of an epoxy compound added in an equivalent amount and (C) an α,β unsaturated ethylenic monomer. 3. (A) The main component is a resin obtained by aminating an epoxidized polybutadiene resin, and contains at least 0.5 equivalents of α, β unsaturated ethylenic groups per equivalent of epoxy group in one molecule of the resin. and has an acid value of 0 to 20 mgK.
OH/g, and the amine value is 20 to 150 mgKOH/
A mixture of the cationic water-soluble resin (g) and the α,β unsaturated ethylenic monomer (C) is poured into water in the presence of a surfactant to form micelles of the above mixture, and then a polymerization initiator is added to the mixture. 1. A method for producing cationically charged polymer particles, which comprises performing radical polymerization in the presence of a cationically charged polymer to obtain a cationically charged polymer dispersion. (A) The main component is a resin obtained by aminating an epoxidized polybutadiene resin, and contains at least 0.5 equivalents of α, β unsaturated ethylenic groups per equivalent of epoxy group in one molecule of the resin. and has an acid value of 0 to 20 mgK.
OH/g, and the amine value is 20 to 150 mgKOH/
g, and (B) a bisphenol A type glycidyl compound having an epoxy equivalent of 200 to 5,000, α,
0.5 to 1 carboxylic acid having β-unsaturated ethylenic group
A mixture of the epoxy compound added in an equivalent amount and (C) the α,β unsaturated ethylenic monomer is poured into water in the presence of a surfactant to form micelles of the above mixture, and then in the presence of a polymerization initiator. A method for producing cationically charged polymer particles, which comprises performing radical polymerization to obtain a cationically charged polymer dispersion. 5. An electrodeposition paint containing the cationically charged polymer particles according to claim 1 or 2.