JPH10273517A - Polyisocianate curing agent for aqueous resin, and water base paint and aqueous adhesive using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curing agent which not only can be used for producing an adhesive having excellent adhesiveness and durability, but also is free from the regulations of the Fire Protection Law (Japan), by mixing a hydrophilic polar group- containing polyisocianate and a thixotropy-imparting agent at a specific ratio, thereby producing a mixture which shows a value higher than a specific value in the test for confirming the liquid state as one of the tests for confirming the dangerous object under the Law. SOLUTION: A ratio of a polyisocianate component to a thixotropy-imparting agent of 100/0.1 to 100/50 is employed. A test result of 90 seconds or more in the test for confirming the liquid state is obtained, which indicates the sample tested is classified as a substance outside the definition of the flammable liquid under the Fire Protection Law. The polyisocianate component is prepared by reacting a polyisocianate (for example, 2,4-tolylenediisocianate), a hydrophilic polar group (preferably, non-ionic polar group)-containing compound, and an active hydrogen-containing compound such as a polyoxyalkylene ether containing one or more active hydrogen groups and having 50 mole % or more of an ethylene oxide-derived unit. It contains 2.0 to 4.0 functional groups on average. As a thixotropy-imparting agent, an amorphous silica, which is capable of imparting thixotropy even when its small amount, is preferred.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curing agent for an aqueous resin in which a thixotropic agent is mixed with a hydrophilic polar group-containing polyisocyanate, and a paint and an adhesive using the same.

[0002]

2. Description of the Related Art Paints, adhesives, coatings, etc., which contain a large amount of organic solvents, have adverse effects on the human body, safety and health problems such as explosions and fires, and pollution problems such as air pollution. Therefore, in order to improve these problems,
Development of water system is being actively conducted. Traditionally,
Although a water-soluble polymer solution or an aqueous emulsion is used, an aqueous one-liquid system often cannot exhibit the performance required in the market. For this reason, a curing agent and a cross-linking agent are used for improving durability and adhesiveness. Various methods have been proposed for the curing / crosslinking system, one of which is to use a hydrophilic group-containing polyisocyanate as a curing agent / crosslinking agent.

[0003] Conventional polyisocyanates containing a hydrophilic polar group are described in JP-A-62-50373 and JP-A-61-50373.
There are those described in, for example, Japanese Patent No. 291613 and the like, in which a hydrophilic surfactant-like structure is introduced into polyisocyanate. Also, Japanese Patent Application Laid-Open No. 8-85716
In Japanese Patent Application Laid-Open Publication No. H11-146, a hydrophilic polar group-containing polyisocyanate having a hydrophilic surfactant and a hydrophobic chain introduced therein is described.

[0004]

However, the hardness, durability, adhesive strength, and the like of a coating film using a conventional hydrophilic polar group-containing polyisocyanate as a curing agent for an aqueous system have reached levels required by the market. There were many things that did not exist. For this reason, the emergence of an aqueous polyisocyanate curing agent capable of exhibiting coating film hardness, durability, adhesive strength, and the like that can withstand actual use has been strongly desired. In the aqueous two-pack paints and adhesives currently used, the main agent is not regulated by the Fire Service Law, but the curing agent is regulated. For this reason, it is strongly desired that the curing agent be made non-dangerous.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in order to solve such a conventional problem. As a result, they have added a thixotropic agent to a polyisocyanate containing a hydrophilic group and confirmed the presence of dangerous substances. In a liquid confirmation test in the test, it was found that a polyisocyanate curing agent that was not determined to be liquid could solve the above problem, and completed the present invention.

That is, the present invention provides the following (1) to (5)
It is. (1) A / B = 100 / 0.1-10 by weight ratio of hydrophilic polar group-containing polyisocyanate (A) and thixotropic agent (B).
A polyisocyanate curing agent for an aqueous resin, wherein the mixture is mixed at 0/50 and the result of a liquid confirmation test in a dangerous substance confirmation test exceeds 90 seconds.

(2) The water-soluble resin and / or 5-100 parts by weight of the polyisocyanate curing agent for water-based resin described in (1) above is added to 100 parts by weight of the solid content of the water-based emulsion in terms of resin content. A water-based paint and a water-based adhesive characterized by the above.

(3) The polyisocyanate curing agent for an aqueous resin described in (1) above is blended in an amount of 5 to 100 parts by weight in terms of resin based on 100 parts by weight of the solid content of the water-soluble resin and / or the aqueous emulsion. A water-based adhesive, characterized in that:

(4) The polyisocyanate curing agent for an aqueous resin described in the above (1) is added to 100 parts by weight of water,
A water-based paint characterized by being blended in an amount of 5 to 100 parts by weight in terms of resin content.

(5) The water-based resin polyisocyanate curing agent as described in (1) above is added to 100 parts by weight of water.
A water-based adhesive characterized by being mixed in an amount of 5 to 100 parts by weight in terms of a resin component.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail. The hydrophilic polar group-containing polyisocyanate (A) in the present invention is obtained by reacting a polyisocyanate (a1) with a compound (a2) containing a hydrophilic polar group and an active hydrogen group.

Examples of the polyisocyanate (a1) include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 2,2'- Diphenylmethane diisocyanate, 1,5-naphthylene diisocyanate, 1,4-
Naphthylene diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, tetramethyl xylylene diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl −4
4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,
4'-diphenylpropane diisocyanate, 3,3 '
Aromatic diisocyanates such as -dimethoxydiphenyl-4,4'-diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, 2-methyl-1,5-pentane diisocyanate, 3-methyl-1,5-pentane diisocyanate, lysine Aliphatic diisocyanates such as aliphatic diisocyanates such as diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated tetramethyl xylylene diisocyanate, cyclohexyl diisocyanate, and two or more kinds of these. There is a mixture of Further, urethane-modified, allophanate-modified, buret-modified, carbodiimide-modified, uretonimine-modified, uretdione-modified organic diisocyanate,
A single product or a mixture such as a modified isocyanurate can also be used. Further, polymeric isocyanates such as polyphenylene polymethylene polyisocyanate and crude tolylene diisocyanate can also be used. The polyisocyanate (a1) used in the present invention is preferably an aliphatic diisocyanate and a modified product thereof, and an alicyclic diisocyanate and a modified product thereof in consideration of reactivity with water.

The compound (a2) containing a hydrophilic polar group and an active hydrogen group includes a compound containing a nonionic polar group and an active hydrogen group, a compound containing an anionic polar group and an active hydrogen group, a compound containing a cationic polar group and an active hydrogen group. Is mentioned.
These have one or more active hydrogen groups. In the present invention, each of them may be used alone, or different kinds of hydrophilic polar group-containing compounds may be used. In consideration of the stability of the obtained curing agent, a nonionic polar group is preferred in the invention.

Examples of the compound containing a nonionic hydrophilic group and an active hydrogen group include polyoxyalkylene ethers and polyoxyalkylene fatty acid esters containing at least one active hydrogen group and containing at least 50 mol% of ethylene oxide units. No.

As the initiator in the production of the above polyoxyalkylene ether, methanol, ethanol,
Examples thereof include n-propanol, i-propanol, n-butanol, i-butanol, t-butanol, cyclohexanol, phenol, ethylene glycol, propylene glycol, aniline, trimethylolpropane, and glycerin. Among these, when the water dispersibility of the polyisocyanate curing agent is considered, compounds having 5 or less carbon atoms, such as methanol, ethanol, ethylene glycol, and propylene glycol, have higher polyisocyanate curing agent hydrophilicity. Therefore, it is preferable.

The fatty acids used for producing the above polyoxyalkylene fatty acid esters include acetic acid, propionic acid, n-butyric acid, i-butyric acid, n-valeric acid, i-valeric acid, caproic acid, glycolic acid, Lactic acid, methoxyacetic acid and the like can be mentioned. Among these, when considering the water dispersibility of the polyisocyanate curing agent, acetic acid, propionic acid, n-butyric acid, i-butyric acid, n-valeric acid, i-valeric acid, etc.
Compounds having 5 or less carbon atoms are preferred because the hydrophilicity of the polyisocyanate curing agent becomes greater.

Also, the polyoxyalkylene ether,
In the polyoxyalkylene ether fatty acid ester or the like, 50 mol% or more, preferably 70 mol% or more of the polyether units are ethylene oxide units, and the number of repeating polyether units is 3 to 9
The number is 0, particularly preferably 5 to 50.

The compound containing an anionic hydrophilic group and an active hydrogen group comprises an organic acid having at least one active hydrogen group and a neutralizing agent. Acids in organic acids include carboxylate, sulfonate, phosphate, phosphonate, phosphinate, thiosulfonate, and the like, and these groups may be introduced independently. And may be related like a chelate.

Examples of the organic acid include α-hydroxypropionic acid, hydroxysuccinic acid, dihydroxysuccinic acid, ε
-Hydroxypropane-1,2,3-tricarboxylic acid,
Hydroxyacetic acid, α-hydroxybutyric acid, hydroxystearic acid, ricinoleic acid, ricinoleic acid, ricinostearol acid, salicylic acid, mandelic acid, etc., oleic acid, ricinoleic acid, hydroxy hydroxylated unsaturated fatty acids such as linoleic acid Fatty acids, glutamine, asparagine, lysine, diaminopropionic acid, ornithine,
Diamine-type amino acids such as diaminobenzoic acid and diaminobenzenesulfonic acid; monoamine-type amino acids such as glycine, alanine, glutamic acid, taurine, aminocaproic acid, aminobenzoic acid, aminoisophthalic acid, and sulfamic acid; or 2,2-dimethylolpropion acid,
Carboxylic acid-containing polyols such as 2,2-dimethylolbutyric acid and 2,2-dimethylolvaleric acid, chelate types such as adducts of iminodiacetic acid and glycidol, 5-sodium sulfoisophthalic acid and 5-potassium sulfoisophthalic acid were used. Examples include polyester polyol, polycaprolactone using water or a carboxyl group-containing alcohol as an initiator, an ester of an active hydrogen group-containing polyester or a transesterified product of an active hydrogen group-containing polycarbonate and a carboxyl group-containing alcohol.

Further, a half-ester containing a carboxyl group obtained by reacting a high molecular polyol, a low molecular polyol such as the aforementioned low molecular glycol, trimethylolpropane, glycerin or the like with a polyamine and a polycarboxylic anhydride. Mixtures and half amide mixtures can also be used. In particular, when a polyol is added to a dianhydride such as pyromellitic anhydride, two carboxylic acids are generated, so that a hydrophilic polar group can be introduced into the molecular chain of the polyester polyol. Other anionic hydrophilic groups include phosphoric acid and the like. In addition, the high molecular polyol mentioned here includes polyester polyol, polyether polyol, polycarbonate polyol and polyolefin polyol.

Examples of neutralizing agents include ammonia, ethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, N-methyldiethanolamine, N-phenyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, Morpholine, N-methylmorpholine, 2-amino-2-ethyl-
Organic amines such as 1-propanol, alkali metals such as lithium, potassium and sodium, sodium hydroxide,
Inorganic alkalis such as potassium hydroxide may be mentioned. In order to improve the weather resistance and water resistance after drying, those having high volatility which easily dissociates by heat are preferable, and ammonia, trimethylamine and triethylamine are preferable. Further, these organic acids and neutralizing agents can be used alone or in combination of two or more.

The compound containing a cationic hydrophilic group and an active hydrogen group is selected from tertiary amines having at least one active hydrogen group, neutralizing agents for inorganic acids and organic acids, and quaternizing agents. Consists of As tertiary amines, N, N
-Dimethylethanolamine, N, N-diethylethanolamine, N, N-dipropylethanolamine,
N, N-diphenylethanolamine, N-methyl-N
-Ethylethanolamine, N-methyl-N-phenylethanolamine, N, N-dimethylpropanolamine, N-methyl-N-ethylpropanolamine, N-
Methyldiethanolamine, N-ethyldiethanolamine, N-methyldipropanolamine, N-phenyldiethanolamine, N-phenyldipropanolamine, N-hydroxyethyl-N-hydroxypropyl-
Methylamine, N, N'-dihydroxyethylpiperazine, triethanolamine, trisisopropanolamine, N-methyl-bis- (3-aminopropyl) -amine, N-methyl-bis- (2-aminopropyl) -amine and the like Is mentioned. Further, those obtained by adding an alkylene oxide to a primary amine such as ammonia or methylamine or a secondary amine such as dimethylamine can also be used.

Examples of the inorganic and organic acids include hydrochloric acid, acetic acid, lactic acid, cyanoacetic acid, phosphoric acid and sulfuric acid. As the quaternizing agent, dimethyl sulfate, benzyl chloride, bromoacetamide, chloroacetamide, or ethyl bromide,
And alkyl halides such as propyl bromide and butyl bromide. Other cationic polar group-containing compounds include cationic compounds such as primary amine salts, secondary amine salts, tertiary amine salts, and pyridinium salts.

Further, an amphoteric polar group such as a sulfobetaine group generated by a reaction between a tertiary amine-containing polyol and sultone can also be introduced.

The neutralizing agent and the quaternizing agent for the anionic and cationic polar groups may be added and the reaction may be performed after the reaction between the polyisocyanate (a1) and the organic acid having an active hydrogen group and / or the tertiary amine. Then, after reacting an organic acid having an active hydrogen group and / or a tertiary amine with a neutralizing agent or a quaternizing agent, the reaction product may be reacted with the polyisocyanate (a1). Sulfonic acid and the like are preferably neutralized before the reaction with the polyisocyanate, and the other anionic and cationic polar groups are preferably neutralized and / or quaternized after the reaction with the polyisocyanate.

The polar group introduction amount in the hydrophilic polar group-containing polyisocyanate (A) used in the present invention is as follows. In the case of introducing a nonionic polar group, (A)
(A2) is 0.1 to 40 wt%, preferably 0.5 to 30 wt%, and more preferably 1 to 30 w%.
t%. In the case where an anionic or cationic polar group is introduced, the amount is 0.1 to 3.0 mmol / g, preferably 0.15 to 2.9 mmol / g.

When the amount of the polar group introduced is less than the lower limit, the modified polyisocyanate is not preferred because the water dispersibility of the modified polyisocyanate deteriorates and, for example, sedimentation occurs. Conversely, if the upper limit is exceeded, the affinity between the modified polyisocyanate and water becomes too strong, so that the stability of the isocyanate group in water deteriorates. When the polar group introduction amount is large, the hydrophilicity can be balanced by increasing the introduction amount of the hydrophobic group and the active hydrogen group-containing compound accordingly, but the isocyanate group content of the hydrophilic group-containing polyisocyanate , And improvement in the weather resistance and the like of the coating film cannot be obtained.

The hydrophilic polar group-containing polyisocyanate (A) in the present invention may be reacted with a compound containing a hydrophobic group and an active hydrogen group, if necessary. Examples of the compound containing a hydrophobic group and an active hydrogen group include methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, t-butanol, pentanol, hexanol, heptanol, octanol,
Low molecular weight monols such as ethylhexanol, benzyl alcohol, cyclohexanol, alkylene glycol monoalkyl ether, low molecular weight primary monoamines such as ethylamine, butylamine and aniline, and low molecular weight second monoamines such as diethylamine, dibutylamine and methylaniline
Monoamines, active hydrogen group-containing polyesters, active hydrogen group-containing polyethers having less than 50 mol% of ethylene oxide units, active hydrogen group-containing polycartes, active hydrogen group-containing polyolefins, hydroxy higher fatty acids having 6 or more carbon atoms and esters thereof, etc. Is mentioned.

The average number of functional groups of the hydrophilic polar group-containing polyisocyanate (A) in the present invention is 2.0 to 5.0,
Preferably, it is 2.0 to 4.0. When the average number of functional groups is less than 2.0, the crosslink density becomes small, so that the coating film strength and the adhesive strength tend to be insufficient. Also, 5.0
When the value exceeds, the crosslink density of the cured product becomes unnecessarily large, and the flexibility of the coating film or the adhesive layer tends to be insufficient.

The reaction temperature in the reaction between the polyisocyanate (a1) and the compound (a2) containing a hydrophilic polar group and an active hydrogen group is 30 to 120 ° C., preferably 40 to 100 ° C.
° C. The compound containing a hydrophobic group and an active hydrogen group, which is used as necessary, may be the same as the introduction of the hydrophilic group, or may be different. At this time, if necessary, a urethanization catalyst such as dibutyltin dilaurate and triethylenediamine may be added. After the reaction, the thixotropic agent (B) is added to the obtained hydrophilic polar group-containing polyisocyanate (A) to obtain the polyisocyanate curing agent for an aqueous resin of the present invention.

The polyisocyanate curing agent for an aqueous resin thus obtained has an isocyanate group content of 5 to 5.
It is 50% by weight, preferably 10 to 40% by weight.

Examples of the thixotropic agent (B) used in the present invention include amorphous silica, silica-alumina mixture, colloidal silica, asbestos powder, and inorganic thixotropic agents such as fatty acid-treated calcium carbonate, organic bentonite, and stearamide. And organic thixotropic agents such as fatty acid amide waxes and modified polyesters. Since these thixotropic agents contain water, if used as they are, they may impair the stability of the resulting curing agent.If necessary, paratoluenesulfonyl isocyanate, fine powder of calcium oxide or magnesium sulfate may be used. Alternatively, a dehydrating agent such as molecular sieve may be used. Preferred among the above-mentioned thixotropic agents are amorphous silicas which can impart thixotropic properties with a small amount.

In the present invention, the mixing ratio of the hydrophilic polar group-containing polyisocyanate (A) and the thixotropic agent (B) is A / B
= 100 / 0.1-100 / 50, preferably 100 /
0.5 to 100/40. When the amount of the thixotropic agent added is 0.1
When the amount is less than 90% by weight, the liquid determination test is performed within 90 seconds. On the other hand, if it exceeds 50% by weight, the isocyanate group content of the polyisocyanate curing agent becomes unnecessarily small, and the durability tends to decrease due to the decrease in crosslink density.

A necessary property of the polyisocyanate curing agent for an aqueous resin of the present invention is that the result of a liquid confirmation test in a dangerous substance confirmation test at 1 atm and a sample temperature of 20 ° C. exceeds 90 seconds. The method of this liquid confirmation test is
The test results are described in "Dangerous Goods Confirmation Manual (New Japan Law Publishing Co., Ltd.)" and the like, and the test result within 90 seconds is judged as "liquid". A polyisocyanate having a liquid confirmation test result of 90 seconds or less corresponds to a fourth-class dangerous substance in the Fire Service Law, that is, a flammable “liquid”. For this reason,
Actual storage and use will be restricted. on the other hand,
Since the result of the liquid confirmation test of the polyisocyanate curing agent for aqueous resin of the present invention exceeds 90 seconds, it is not "liquid", that is, not flammable "liquid". Therefore, it can be used without being restricted by the Fire Service Law.

The water-based paint and water-based adhesive of the present invention are obtained by blending the above-mentioned polyisocyanate curing agent for water-based resin with a water-soluble resin and / or water-based emulsion. Applications include paints (including coatings) and adhesives for metals, woodwork, plastics, inorganic materials and the like. By blending the two components, it is possible to improve the adhesion due to the isocyanate group present in the curing agent, and to improve the strength and hardness durability by forming a crosslink.

The water-soluble resin used in the water-based paint and water-based adhesive of the present invention includes polyvinyl alcohol, polyethylene oxide, a water-soluble ethylene-vinyl acetate copolymer, a water-soluble acrylic resin, a water-soluble epoxy resin, a water-soluble epoxy resin. Examples thereof include a cellulose derivative, a water-soluble polyester, a water-soluble lignin derivative, a water-soluble fluororesin, and a water-soluble silicone resin.

The water-based emulsion used in the water-based paint and water-based adhesive of the present invention includes all of what is called latex and emulsion. For example, styrene butadiene copolymer latex, acrylonitrile butadiene copolymer latex, methyl methacrylate-butadiene copolymer latex, chloroprene latex, rubber-based latex such as polybutadiene latex, polyacrylate latex, polyvinylidene chloride latex, Examples thereof include polybutadiene latex and those obtained by carboxyl-modifying these latexes, and examples thereof include polyvinyl chloride emulsion, urethane acrylic emulsion, silicone acrylic emulsion, vinyl acetate acrylic emulsion, polyurethane emulsion, and acrylic emulsion. In addition, fluorine emulsions having excellent weather resistance and stain resistance are poor in solvent resistance due to non-crosslinking.However, by using the polyisocyanate curing agent for aqueous resin of the present invention, weather resistance, stain resistance and resistance to contamination are reduced. Solvent properties can be further improved.

The water-soluble resin and / or the water-based emulsion used in the present invention may contain no active hydrogen groups capable of reacting with isocyanate groups or may contain only a small amount of active hydrogen groups. The polyisocyanate curing agent for use reacts with water in a water-soluble resin and / or an aqueous emulsion to form a polyurea compound, and forms a hard and tough coating film, thereby improving weather resistance. Further, since the isocyanate group reacts with an active hydrogen group existing on the surface of the adherend, the adhesion is also improved. However, when a water-soluble resin and / or an aqueous emulsion containing a large amount of active hydrogen groups that can react with isocyanate groups at room temperature are used, the active hydrogen groups in the polymer and the isocyanate groups in the polyisocyanate curing agent for the aqueous resin are used. Reacts to form a crosslinked structure, so that weather resistance, solvent resistance, and the like are further improved. In addition, when baking is performed at a high temperature, in the uretdione group-containing type, the uretdione group is dissociated and an isocyanate group is generated. Therefore, it is more preferable that the water-soluble resin and / or the water-based emulsion contain an active hydrogen group capable of reacting with an isocyanate group.

The compounding method of the polyisocyanate curing agent for water-based resin of the present invention and the water-soluble resin and / or water-based emulsion may be added as it is, temporarily disperse the water-based resin curing agent in water, or use a solvent commonly used in urethane industry. It is compounded by a method such as dissolving in water. A preferred method is to disperse the polyisocyanate curing agent for water-based resin in water and then blend it.

In the water-based paint and water-based adhesive of the present invention, the amount of the hydrophilic polar group-containing polyisocyanate hardener added to the water-soluble resin and / or water-based emulsion is determined by the solid content of the water-soluble resin and / or water-based emulsion. 0.5 to 100 parts by weight, preferably 1 to 8 parts by weight, based on 100 parts by weight of the resin component of the polyisocyanate curing agent for an aqueous resin.
0 parts by weight, more preferably 50 to 60 parts by weight.

The water-based paint and water-based adhesive of the present invention are obtained by blending the above-mentioned water-based resin polyisocyanate curing agent with water. Applications include paints (including coatings) and adhesives for metals, woodwork, plastics, inorganic materials and the like.

In the water-based paint and water-based adhesive of the present invention, the mixing ratio of water and the polyisocyanate curing agent for water-based resin is 1 to 100 parts by weight based on 100 parts by weight of water. Parts by weight, preferably 10 to 100 parts by weight, more preferably 20 to 100 parts by weight. This dispersion becomes a paint (coating agent) or adhesive with very good adhesion because the isocyanate groups which are present relatively stably even after being dispersed in water react with the active hydrogen present on the surface of the substrate. . In addition, a considerable amount of time has elapsed after the dispersion in water, and the dispersion in water after the isocyanate groups have disappeared stably exists as an emulsion having a particle size of about 0.1 to 0.3 μm. Since the coating mainly composed of the urea compound obtained by drying becomes hard and tough, it can be used as a film or sheet, or as a coating agent for various substrates. When importance is attached to the adhesion to the base material, it is desirable to use in a state where the isocyanate group is present.

In the paint (including the coating agent) and the adhesive using the polyisocyanate curing agent for water-based resin of the present invention, additives and auxiliaries commonly used in water-based two-component systems may be used, if necessary. it can. For example, pigments, dyes, dispersion stabilizers, viscosity modifiers, leveling agents, anti-gelling agents,
Light stabilizer, antioxidant, ultraviolet absorber, heat resistance improver,
Inorganic and organic fillers, plasticizers, lubricants, antistatic agents, reinforcing materials, catalysts and the like can be added.

The application fields of the polyisocyanate curing agent for water-based resin of the present invention include, in addition to paints and adhesives,
It can be used as sealant, ink, fiber / glass fiber treatment agent, and sizing agent. The effect of the addition is that a cured product or a processed product having better adhesion and durability than conventional products can be obtained.

[0045]

EXAMPLES The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited to these examples. In Examples and Comparative Examples, “parts” were used.
Means "parts by weight", and "%" means "% by weight".

Example 1 In a planetary mixer, coronate HX which is an isocyanurate-modified hexamethylene diisocyanate was added.
86 parts (manufactured by Nippon Polyurethane Industry) and 14 parts of Monool (1) were charged and reacted at 70 ° C. for 3 hours. Then, when cooled to 40 ° C., 4 parts of thixotropic agent A were charged and sufficiently dispersed to obtain polyisocyanate curing agent A for an aqueous resin. The isocyanate group content of A was 16.2%.

Example 2 A planetary mixer was charged with 98 parts of Millionate MR-200 (manufactured by Nippon Polyurethane Industry), a mixture of diphenylmethane diisocyanate and polymethylene polyphenylene polyisocyanate, and 2 parts of monool (2) at 70 ° C. For 3 hours. Then, when cooled to 40 ° C., 25 parts of thixotropic agent B was charged,
After sufficient dispersion, a polyisocyanate curing agent B for an aqueous resin was obtained. The isocyanate group content of B was 24.2%.

Example 3 86 parts of coronate HX, 10 parts of monol (3) and 4 parts of monol (4) were charged into a planetary mixer and reacted at 70 ° C. for 3 hours. Thereafter, when cooled to 40 ° C., 2 parts of thixotropic agent A were charged and sufficiently dispersed to obtain a polyisocyanate curing agent C for an aqueous resin. The isocyanate group content of C was 17.4%.

Example 4 98 parts of isophorone diisocyanate was charged into a four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, and heated to 50 ° C. Thereafter, 2 parts of diol (1) was charged and reacted at 70 ° C. for 3 hours. Then, when cooled to 40 ° C., thixotropic agent A is added with 1
0 parts were charged and sufficiently dispersed to obtain a polyisocyanate curing agent D for an aqueous resin. The isocyanate group content of D was 33.6%.

Example 5 A reactor similar to that of Example 4 was charged with 3,000 parts of hexamethylene diisocyanate and 6 parts of trioctylphosphine as a uretdionation and isocyanuration catalyst.
The mixture was heated to 65 to 70 ° C. with stirring and reacted at the same temperature for 6 hours. Next, 3.5 parts of phosphoric acid was added to stop the reaction, and a pale yellow reaction product liquid having an isocyanate group content of 30.3% was obtained. From this reaction solution, unreacted HDI was removed by thin-film distillation at 120 ° C. and 0.01 Torr. An isocyanate group content = 18.7% of the product, from the FT-IR and C ¹³ -NMR, isocyanate groups in this product, is that there are uretdione groups and isocyanurate groups was confirmed. The product was heated to 180 ° C. to dissociate the uretdione group, and the total amount of the isocyanate group and the isocyanate group generated by dissociation of the uretdione group originally present was determined. The content of isocyanate groups generated by dissociation of uretdione groups was 12.1%. Further, the isocyanurate group content was 19.2%. This is designated as P-1. 86 parts of P-1 and 14 parts of the monol (1) were charged into a planetary mixer and reacted at 70 ° C. for 3 hours. Thereafter, when cooled to 40 ° C., 4 parts of thixotropic agent A were charged and sufficiently dispersed to obtain polyisocyanate curing agent E for an aqueous resin. The isocyanate group content of E was 14.1%.

Example 6 80 parts of Coronate HX and 20 parts of Monool (5) were charged into a planetary mixer and reacted at 70 ° C. for 3 hours. Thereafter, after cooling to 50 ° C., 4 parts of triethylamine as a neutralizing agent was charged and reacted at the same temperature for 2 hours. Thereafter, 6 parts of thixotropic agent A were charged and sufficiently dispersed to obtain a polyisocyanate curing agent F for an aqueous resin. The isocyanate group content of F was 14.0%.

Example 7 A planetary mixer was charged with 93 parts of coronate HX and 7 parts of monool (6), and reacted at 70 ° C. for 3 hours. Then, after cooling to 50 ° C., 6 parts of ethyl bromide as a quaternizing agent was charged and reacted at the same temperature for 2 hours. Thereafter, 4 parts of thixotropic agent A were charged and sufficiently dispersed.
A polyisocyanate curing agent G for an aqueous resin was obtained. The isocyanate group content of G was 15.7%.

Comparative Example 1 86 parts of Coronate HX and 14 parts of Monool (1) were charged into a planetary mixer and reacted at 70 ° C. for 3 hours to obtain a polyisocyanate curing agent H for an aqueous resin. The isocyanate group content of H was 16.8%.

Comparative Example 2 86 parts of Coronate HX and 14 parts of Monool (1) were charged into a planetary mixer and reacted at 70 ° C. for 3 hours. Then, when cooled down to 40 ° C,
60 parts of thixotropic agent A were charged and dispersed to obtain polyisocyanate curing agent I for an aqueous resin. The isocyanate group content of I was 10.5%.

Comparative Example 3 100 parts of Coronate HX was added to a planetary mixer.
60 parts of thixotropic agent A were charged and sufficiently dispersed to obtain a polyisocyanate curing agent J for an aqueous resin. The isocyanate group content of J was 20.5%. Table 1 shows Examples 1 to 7.
And Comparative Examples 1 to 3 are shown.

[0056]

[Table 1]

In Examples 1 to 7 and Comparative Examples 1 to 3, in Table 1, C-HX: coronate HX isocyanate group content = 21.3% MR-200: millionate MR-200 isocyanate group content = 31.0% IPDI: isophorone diisocyanate monol (1): ethylene oxide / propylene oxide = 100/0 Initiator = methanol Monool having a number average molecular weight of 400 Monool (2): ethylene oxide / propylene oxide = 80/20 initiator = ethanol number Monool having an average molecular weight of 700 Monool (3): ethylene oxide / propylene oxide = 90/10 Initiator = methanol Monool having a number average molecular weight of 1,000 Monool (4): methyl ricinoleate monool (5): Initiator = Hydro Xyacetic acid terminal carboxylic acid, polycaprolactone having the other terminal hydroxyl group monool having a number average molecular weight of 1,000 monool (6): diethylethanolamine diol (1): ethylene oxide / propylene oxide = 90/10 initiator ethylene glycol Diol having a number average molecular weight of 1,000 Thixotropic agent A: Aerosil 300 (Nippon Aerosil) Amorphous silica type Thixotropic agent B: Calfine 200M (Maruo calcium) Fatty acid-treated calcium carbonate type

In the aqueous resin curing agents obtained in Examples 1 to 7 and Comparative Examples 1 to 3, the dispersion state of the thixotropic agent was visually observed.
A liquid confirmation test and an evaluation of water dispersibility were performed. Table 2 shows the results
Shown in [Liquid confirmation test method] (1) The temperature of the water in the thermostatic bath is set to 20 ° C ± 0.1 ° C. (2) A sample is put in a flat bottomed cylindrical transparent glass tube having an inner diameter of 30 mm and a height of 120 mm with a marked line at 55 mm and 85 mm from the bottom of the tube to the underline of the marked line. Prepare two of these. (3) One test tube containing the sample is sealed with a rubber stopper having no hole. (Hereinafter, this is referred to as a test tube for judging liquid.) (4) The other test tube containing the sample is sealed with a rubber stopper equipped with a thermometer. (Hereinafter, this is referred to as a temperature measurement test tube.) The tip of the thermometer is 30 m from the sample surface.
m depth. (5) The two test tubes are allowed to stand upright in a thermostatic water bath so that the upper line of the marked line sinks below the water surface. (6) The sample in the test tube for temperature measurement is
The temperature is maintained for another 10 minutes after the temperature reaches ℃. (7) The test tube for judging liquid is taken out of the thermostatic water bath while standing upright on a horizontal table, immediately dropped horizontally on the table, and the time until the tip of the sample reaches the upper line of the marked line is measured. [Water dispersibility test method] 100 parts of water was mixed with 50 parts of a polyisocyanate curing agent for an aqueous resin, and the mixture was stirred at a high speed for 30 seconds with a homomixer to visually evaluate the state of the aqueous dispersion.

[0059]

[Table 2]

In Table 2, the thixotropic agent dispersion state ：: Uniformly dispersed ×: “Dama” -like substance or precipitate can be confirmed in liquid confirmation test ○: More than 90 seconds ×: Within 90 seconds Water dispersion state ○: Uniformly dispersed ×: "Dama" -like substance and precipitate can be confirmed

[Synthesis of Aqueous Acrylic Emulsion] In a reactor equipped with a stirrer, a thermometer, a nitrogen sealed tube, and a condenser,
170 parts of ion-exchanged water, 4 parts of Levenol WZ (anionic emulsifier, manufactured by Kao), 1 part of Neugen EA-170 (nonionic emulsifier, manufactured by Daiichi Kogyo Seiyaku), and 80 ° C.
Until heated. Then 300 parts of methyl methacrylate,
Butyl acrylate 180 parts, acrylic acid 4 parts, diacetone acrylamide 5 parts, ion exchange water 330
Parts, a mixture of 5 parts Neugen EA-170 and 1 part potassium peroxide (initiator) at a temperature of 80
The solution was added dropwise over 3 hours while keeping the temperature at 80 ° C, and then reacted at 80 ° C for 3 hours. After the reaction is completed, cool to room temperature and add 25%
The pH was adjusted to 8 with an aqueous ammonia solution, and the solid content was 49.5.
% Aqueous acrylic emulsion was obtained.

[Evaluation of Paint] Example 8 100 parts of an acrylic emulsion was mixed with 10 parts of a polyisocyanate curing agent A for an aqueous resin, and the mixture was stirred at a high speed for 30 seconds with a homomixer to prepare a clear paint. The clear paint was applied to an aluminum plate with an applicator so as to have a dry film thickness of 20 μm, and then cured at 50 ° C. for 20 hours to obtain a coated sample.

Examples 9 to 14 and Comparative Example 4 Coating samples were prepared in the same manner as in Example 8 except that the polyisocyanate curing agents BG and J for the aqueous resin were used instead of the polyisocyanate curing agent A for the aqueous resin. Obtained.

Example 15 25 parts of water-based resin polyisocyanate curing agent A was mixed with 75 parts of water, and the mixture was stirred at a high speed for 30 seconds with a homomixer to prepare a clear paint. The clear coating was applied to an aluminum plate with an applicator so as to have a dry film thickness of 20 μm, and then cured at 50 ° C. for 20 hours to obtain a coating sample.

Examples 16 to 21 and Comparative Example 5 Coating samples were prepared in the same manner as in Example 15 except that polyisocyanate curing agents BG and J for aqueous resin were used instead of polyisocyanate curing agent A for aqueous resin. I got The coating evaluation results are shown in Tables 3 and 4.

[0066]

[Table 3]

[0067]

[Table 4]

[Coating Evaluation Method] Solvent resistance: Xylene was impregnated into absorbent cotton and rubbed onto the coating film. ：: No change in appearance at 200 times. Δ: The coating film surface fogged after 100 cycles. ×: The coating film is broken after 50 times or less. Water resistance: The coated sample was immersed for one week to evaluate the appearance. ：: no change in appearance. ×: The coating film surface whitens The cross-cut peeling test was measured by the method specified in JIS K-5400.

[Evaluation of Adhesive] Example 22 20 parts of the polyisocyanate curing agent A for an aqueous resin was blended with 100 parts of the acrylic emulsion, and the mixture was stirred at a high speed with a homomixer for 30 seconds to prepare an adhesive. This adhesive was brush-coated on a birch plate so as to have a coating amount of 300 g / m ² (wet), and the coated surface was bonded to the coated surface.
Then, it was cured at 80 ° C. for 10 minutes and further at room temperature for 24 hours to obtain an adhesive sample.

Examples 23 to 26 and Comparative Example 6 In the same manner as in Example 22, polyisocyanate curing agents for water-based resin C, E, F, H and J were used instead of polyisocyanate curing agent A for water-based resin. Was used to obtain an adhesive sample.

Example 27 To 75 parts of water, 25 parts of a polyisocyanate curing agent A for an aqueous resin were mixed, and the mixture was stirred at a high speed with a homomixer for 30 seconds to prepare an adhesive. Apply this adhesive to the birch board in an amount of 3
Brush it so that it becomes 00 g / m ² (wet)
Coating surface-Coating surface was bonded. Then, at 80 ° C, 1
The mixture was cured for 0 minutes and at room temperature for 24 hours to obtain an adhesive sample.

Examples 28 to 31 and Comparative Example 7 In the same manner as in Example 27, polyisocyanate curing agents C, E, F, H, and J for an aqueous resin were used in place of polyisocyanate curing agent A for an aqueous resin. Was used to obtain an adhesive sample. Tables 5 and 6 show the adhesion evaluation results.

[0073]

[Table 5]

[0074]

[Table 6]

[Adhesion evaluation method] Normal adhesive strength: The adhesive sample was measured for compressive shear adhesive strength at 20 ° C. and 1 atm. Boiling repetition adhesive strength: 4 hours in boiling water + 60 ° C x 20
Time (dry) +4 hours in boiling water + Leave the sample in water until boiling water is immersed → Measure compressive shear adhesive strength while wet. Compression shear adhesive strength measurement conditions: Compression speed = 1 m / min

[0076]

The polyisocyanate curing agent for water-based resin of the present invention comprises the following conventional water-based polyisocyanate-based curing agent:
With respect to the resin used as the main agent, it was possible to develop levels of adhesion and durability that could not be achieved until now. Further, the polyisocyanate curing agent for an aqueous resin of the present invention is not subject to the regulations of the Fire Service Law. And the paint and adhesive using this curing agent also showed good performance.

Claims (5)

[Claims] 1. A hydrophilic polar group-containing polyisocyanate (A) and a thixotropic agent (B) in a weight ratio of A / B = 100/0.
A polyisocyanate curing agent for an aqueous resin, wherein the mixture is mixed at 1 to 100/50 and the result of a liquid confirmation test in a hazardous substance confirmation test exceeds 90 seconds. 2. The water-soluble resin and / or 100 parts by weight of the solid content of the water-based emulsion, the polyisocyanate curing agent for water-based resin according to claim 1 is added in an amount of 0.5% in terms of resin content.
A water-based paint and a water-based adhesive characterized by being mixed in an amount of 100 parts by weight. 3. A water-soluble resin and / or 100 parts by weight of a solid content of an aqueous emulsion, wherein the polyisocyanate curing agent for an aqueous resin according to claim 1 is added in an amount of 0.5% in terms of resin content.
A water-based adhesive characterized by being mixed in an amount of 100 parts by weight. 4. A water-based paint comprising the water-based resin polyisocyanate curing agent according to claim 1 in an amount of 5 to 100 parts by weight, based on 100 parts by weight of water. 5. A water-based adhesive comprising the water-based resin polyisocyanate curing agent according to claim 1 in an amount of 5 to 100 parts by weight in terms of resin based on 100 parts by weight of water.