JP3489188B2 - Crosslinked water-dispersed resin composition - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to adhesives, coatings and paints, and more particularly to adhesives and coatings for water-permeable substrates such as concrete, woven fabric, wood and paper. The present invention relates to a water-dispersed resin composition useful as an agent and a paint. 2. Description of the Related Art In the fields of adhesives, coatings, paints, and the like, there is an increasing tendency to shift from solvent-based to water-based in terms of resource saving, work environment hygiene, environmental pollution, dangerous substances, and the like. Is coming. For example, in the field of paints, interest in water-based emulsion paints has been growing.However, conventional water-based emulsion paints have the disadvantage that the film strength is inevitably lower than that of organic solvent-based paints because the film is formed by the coalescence of particles. I was As a method of solving this, it is conceivable to use a polyhydrazide compound to form a crosslinked coating film from an acrylic emulsion containing a ketone group or an aldehyde group, and these are known as a crosslinked water-dispersed resin composition (Japanese Patent Application Laid-Open No. -1
10248, JP-A-54-144432, JP-A-5-144
JP-A-5-147562, JP-A-57-3857, JP-A-60-38468, JP-A-62-72742, JP-A-2-138376, JP-A-2-175742, JP-A-4-249587 ). In the case of this combination, a crosslinking reaction at room temperature is possible, but when an acrylic emulsion containing a carboxyl group other than the acrylic emulsion containing a ketone group or an aldehyde group is used, heating is required for crosslinking with the polyhydrazide compound. In such a compounding system, generally used polyhydrazide compounds, such as adipic dihydrazide and succinic dihydrazide, have practical disadvantages as shown below.
1: A uniform coating film surface cannot be obtained, and problems such as adhesion may occur. 2: Since the solubility of the polyhydrazide compound in water at room temperature is low, the amount of water is inevitably increased when forming a one-pack formulation, and the film formation drying time is prolonged. [0003] The present invention overcomes the drawbacks of the conventional cross-linked aqueous dispersion composition in the film formation state and the disadvantages of long film formation drying time, and provides a good film formation state. It is to provide a reduction in the membrane drying time. The inventors of the present invention have made intensive studies to solve the problems of the above-mentioned conventional cross-linked aqueous dispersion composition. As a result, 1,3-bis (hydrazinocarboethyl) was obtained. -
5-isopropylhydantoin (hereinafter abbreviated as VDH)
You. The present inventors have found that the above-mentioned problem can be solved by (1 ), and have completed the present invention. That is, the present invention relates to (A) an acrylic copolymer aqueous resin emulsion into which a ketone group or an aldehyde group is introduced, and (B) VDH
The present invention relates to a crosslinked water-dispersed resin composition characterized by comprising: The component (A) used in the present invention includes:
For example, at least (a) a monomer having radical polymerizability, (b) an unsaturated compound having a ketone group or an aldehyde group, and (c) produced by emulsion polymerization of an unsaturated carboxylic acid in an aqueous dispersion. These are described in JP-A-54-110248, JP-A-54-144432, JP-A-55-147562, JP-A-57-3857, and JP-A-62-157.
No. 72742, and the like. As the monomer having radical polymerizability of the component (a), esters of acrylic acid such as methyl acrylate and ethyl acrylate, esters of methacrylic acid, vinyl aromatic compounds, vinyl aliphatic compounds, vinyl halides, acrylamide and Methacrylamide and the like. The unsaturated compound having a ketone group or aldehyde group of the component (b) is
A carbonyl group-containing compound having at least one aldehyde group or ketone group and one polymerizable double bond in the molecule, comprising an ester group (-COO-), a carboxyl group
Compounds having only (-COOH) are excluded, acrolein,
Examples include diacetone acrylamide and vinyl methyl ketone. In addition, as the unsaturated carboxylic acid of the component (c), acrylic acid, methacrylic acid, maleic acid, and the like are used, but are not limited thereto. (a) to (c)
The ratio of the components is selected depending on the purpose, but the component (a) is used alone or in combination of two or more depending on the use.
The resin particle size of the acrylic copolymer aqueous resin emulsion in the present invention is 0.01 to 3 μm, and the film forming temperature of the dispersion is 60 ° C. or less, preferably −40 ° C. to + 30 ° C.
It is. As the component (B) , for example, 1,3-bis (hydrazinocarboethyl) -5- (2-methylmercaptoethyl) hydantoin, 1-hydrazinocarboethyl-3-hydrazinocarboisopropyl-5- ( 2-Methylmercaptoethyl) hydantoin, thiodipropionic dihydrazide, oxydipropionic dihydrazide, oxydiglycolic dihydrazide, N, N'-dihydrazinocarboethylpiperazine, etc. cannot be used.
Although not a problem , 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin (VDH) is excellent in that it has a high water solubility and a uniform and good coating film with little coloring can be obtained. VDH of the component (B) is (A)
For 1 equivalent of the sum of the ketone group and the aldehyde group of the component,
The component (B) is used so that the -NH.NH2 group content of the component is 0.02 to 5 molar equivalents, preferably 0.1 to 2 molar equivalents. The composition of the present invention may further contain an antifoaming agent, a film-forming aid, a plasticizer, a thickener, a dye, a pigment, a filler, an antifreezing agent, and the like. Further, the aqueous resin emulsion of the present invention may be mixed with a water-soluble copolymer which is a room temperature crosslinkable water retention agent, a room temperature crosslinkable polyurethane / acrylic resin aqueous emulsion or another aqueous emulsion which does not inhibit crosslinkability, without impairing the original performance. Can be added with. The crosslinked water-dispersed resin composition causes a crosslinking reaction by drying of water,
A film is formed. Conversely, since the system is stable as long as water is present, the storage stability is good. Now, the present invention will be described in further detail with reference to Examples. All parts and percentages are by weight unless otherwise indicated. (Solubility of hydrazide compound) 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin “Amicure VDH (VDH)”
(Manufactured by Ajinomoto Co., Inc.) , adipic acid dihydrazide “AD
H "(manufactured by Nippon Hydrazine Industry Co., Ltd.) and isophthalic acid dihydrazide" IDH "(Nippon Hydrazine Industry Co., Ltd.)
Co., Ltd.), succinic dihydrazide “SaADH” (Aldr
ich), oxalic acid dihydrazide “ODH” (Aldri)
ch)) and malonic acid dihydrazide “MDH” (manufactured by Nippon Hydrazine Industry Co., Ltd.) in water at 25 ° C. were measured. [ Table 1] (Blending of Emulsion and Crosslinking Agent) Polyacrylic acid emulsion containing carbonyl group "Selna WE-518" (manufactured by Chukyo Yushi Co., Ltd., solid content 50%)
And 1,3-bis (hydrazinocarboethyl) -5-isopropylhydantoin “VDH” (Ajinomoto Co., Inc.)
10% aqueous solution of “VDH” , adipic dihydrazide “ADH” (manufactured by Nippon Hydrazine Industry Co., Ltd.),
10% aqueous solution of [ADH], isophthalic acid dihydrazide “IDH” (manufactured by Nippon Hydrazine Industry Co., Ltd.), succinic acid dihydrazide “SaADH” (manufactured by Aldrich), oxalic acid dihydrazide “ODH” (manufactured by Aldrich), malonic acid dihydrazide “MDH” (Manufactured by Nippon Hydrazine Industry Co., Ltd.) and butyl cellosolve as a film-forming aid in combination with Table 2 in order to improve drying and wetting properties. A water-dispersed resin composition was obtained. (Evaluation of Samples) In the case of room temperature curing: the compositions obtained in Examples 1 to 5 and Comparative Examples 1 to 6 were applied to an aluminum plate to form a film using an applicator so as to have a thickness of about 5 microns after drying. After standing at room temperature, this was used as a sample. In case of heat curing; Examples 1 to 5 on aluminum plate
Then, the compositions obtained in Comparative Examples 1 to 6 were formed into a film using an applicator so as to have a thickness of about 50 microns after drying.
After heating at 0 ° C. for 15 minutes, this was used as a sample. (Evaluation method) Appearance: The surface condition of the film is visually observed, and is indicated by “O” for a uniform and good surface, and “X” for a rough and uneven surface. Film formation drying time; this was measured only in the case of room temperature curing. After forming the film with the applicator, the time required until the tack disappeared was measured with a stopwatch. Cross cut test: 100 pieces of 1 mm square were cut on the coating film surface, and the number of squares that did not peel off after peeling off the cellophane tape was displayed. [ Table 2] The crosslinked water-dispersed resin composition of the present invention comprises:
Suitable for applications such as clear coating agents, top coating agents, undercoating agents, adhesives, and cloth and paper impregnating agents, because the film formation condition is good and a uniform film surface is obtained, and the time required for film formation is short. ing. Further, since the system is stable as long as water is present in the system, storage stability is good. Furthermore, since the composition of the present invention is water-based, it is very useful in terms of environmental hygiene, pollution, dangerous substances, and the like, as compared with solvent systems commonly used in the world.

Claims (1)

(57) [Claim 1] (A) Acrylic copolymer aqueous resin emulsion into which ketone group or aldehyde group is introduced and (B) 1,3-bis (hydrazinocarboethyl)- 5
-A crosslinked water-dispersed resin composition comprising -isopropylhydantoin .