JP3325315B2 - Aqueous polyurethane resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to metal adhesion, corrosion resistance,
The present invention relates to an aqueous polyurethane resin composition having excellent moisture resistance and useful as a paint and an adhesive.

[0002]

2. Description of the Related Art Aqueous polyurethane resins are used as sealers or top coats for paints, adhesives, aqueous inks, leather, paper, metals, plastics, wood, rubber, inorganic materials and the like. For example, JP-A-53-45398
JP-A-63-305119, JP-A-2-2051
No. 1 and the like are known, but none of these inventions has sufficient performance with respect to metal adhesion, corrosion resistance, and moisture resistance. Japanese Patent Application Laid-Open (JP-A) No. 63-158 discloses a polyfunctional aziridine or epoxy which is used as a crosslinking agent to improve the performance.
No. 16, JP-A-63-256661, etc. are known, but these inventions are also insufficient in metal adhesion and corrosion resistance even though they have sufficient stability.

[0003]

SUMMARY OF THE INVENTION The present invention has been intensively studied to solve the above problems, and as a result, an aqueous polyurethane resin composition containing a polyvalent metal complex as a cross-linking agent has a metal adhesion,
The inventors have found that they have excellent corrosion resistance and moisture resistance, and have completed the present invention.

[0004]

That is, the present invention provides an aqueous polyurethane resin composition excellent in metal adhesion obtained by adding a polyvalent metal complex as a crosslinking agent to a polyurethane resin containing a carboxyl group and / or a salt of a carboxyl group. It is about things.

The carboxyl group and / or a carboxyl group-containing polyurethane resin fat according to the present invention contains a carboxyl group and / or a carboxyl group salt in the chain of the polyurethane resin. For example, it is obtained by adding a carboxyl group-containing polyol or the like to a polyol or an isocyanate compound and producing (neutralizing the carboxyl group as necessary) polymerization in the production of a polyurethane resin. That is,
By introducing a carboxyl group as described above, the polyurethane-based resin can be made into a self-emulsifying or water-soluble aqueous polyurethane resin. The amount of the carboxyl group and / or the salt of the carboxyl group contained in the polyurethane resin can be expressed as an acid value, and the acid value of the present invention is 10 to 100 KOHmg.
/ G (as solid content) is appropriate. When the acid value is less than 10, the polyurethane resin is less likely to self-emulsify, has a large particle size, and tends to lack stability. Further, a coating film formed using an aqueous polyurethane resin composition containing such a polyurethane-based resin does not exhibit sufficient performance. On the other hand, when the acid value exceeds 100, the self-emulsifiability and water solubility of the polyurethane resin are tentatively 100.
It is as good as the following case. However, a coating film formed using an aqueous polyurethane resin composition containing such a polyurethane resin has poor water resistance. In the present invention, any known base that forms a salt of a carboxyl group can be used, and particularly preferred examples include dimethylethanolamine, diethylethanolamine, and triethylamine.

As the above-mentioned carboxyl group-containing polyol, any polyol can be used as long as it imparts a carboxyl group to the polyurethane resin chain in a branched manner. However, the carboxyl group content in the polyurethane resin chain is increased. Is preferably a low-molecular-weight compound having at least one branched carboxyl group and having 3 to 10 carbon atoms, for example,
2,2-dimethylolpropionic acid and the like are particularly preferred.
Examples of the above isocyanate compound include 1,4
Aliphatic isocyanates such as tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, and 2,8-diisocyanate methyl caproate;
-Isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate, methylcyclohexyl-
Aliphatic diisocyanates such as 2,4-diisocyanate, toluylene diisocyanate, diphenylmethane diisocyanate, 1,5-naphthene diisocyanate,
Aromatic diisocyanates such as diphenylmethylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 4,4-dibenzyl isocyanate, 1,3-phenylene diisocyanate, chlorinated diisocyanates, brominated diisocyanates or polyisocyanates which are adducts with water One kind or a mixture of two or more kinds of compounds is used.

The polyols used in the present invention include known polyols usually used in the production of urethane resins, for example, diethylene glycol, butanediol, hexanediol, neopentyl glycol, bisphenol A, cyclohexane dimethanol, trihexane Methylolpropane, glycerin, pentaerythritol,
Examples thereof include one or a mixture of two or more of polyethylene glycol, polycarbonate polyol, polypropylene glycol, polyester polyol, polycaprolactone, polytetramethylene ether glycol, polythioether polyol, polyacetal polyol, polybutadiene polyol, and furan methanol.

In the present invention, an epoxy compound having the following two epoxy groups can be further added to the above aqueous polyurethane resin composition. Such an epoxy compound having two epoxy groups is commercially available under the following trade names and can be easily obtained. Such epoxy compounds include, for example, Epicoat 828, Epicoat 1001, Epicoat 1002, Epicoat 1004, Epicoat 100 as epoxy compounds having two epoxy groups.
7, Epicoat 1009 (manufactured by Shell Chemical Co., Ltd.), Epolite 400E, Epolite 200E, Epolite 40E,
Epolite 80MF (manufactured by Kyoeisha Yushi Kagaku Kogyo KK), Denacol EX810, 811, 851, 830, 832,
841, 861, 911, 941, 920, 921, 9
31, 211, 212, 221, 721, 313 (manufactured by Nagase Kasei Kogyo Co., Ltd.). Examples of epoxy compounds having three epoxy groups include Denacol EX314, 321 and 4
21, 512, 521 (manufactured by Nagase Kasei Kogyo), Epicoat 152, 154 (manufactured by Shell Chemical Co., Ltd.), and the like. Examples of epoxy compounds having four epoxy groups in one molecule include Denacol EX611 and 61.
2,614,614B, 622 (manufactured by Nagase Kasei Kogyo Co., Ltd.)
And so on. 2 epoxy groups per molecule
The compounding ratio of the epoxy compound having one or more is preferably 1 to 20 parts by weight (in terms of solid content) based on 100 parts by weight of the polyurethane resin.

In the present invention, a polyurethane copolymer resin such as a urethane-acrylic copolymer resin, a urethane-styrene copolymer resin, a urethane-butadiene copolymer resin can also be used. Also, in the composition of the present invention, acrylic emulsion, styrene emulsion,
Polymer resins other than aqueous polyurethane resins, such as styrene-acryl emulsions, polyethylene wax emulsions, and alkali-soluble resin solutions, can be used in combination. The composition of the present invention is obtained by adding a polyvalent metal complex to the above aqueous polyurethane resin. That is, the polyvalent metal in the polyvalent metal complex compound used in the composition of the present invention is a divalent or higher valent metal, for example, calcium, magnesium, zinc, barium, aluminum,
Zirconium can be used. In particular, calcium, zinc, and aluminum exhibit desirable performance. In addition, the amount of the polyvalent metal complex added to the aqueous polyurethane resin is such that the polyvalent metal complex containing 0.05 to 1.0 equivalent of the polyvalent metal with respect to the carboxyl group of the polyurethane resin is used. Preferably, it is used.

The ligand for forming the polyvalent metal complex includes, for example, carbonate ion, acetate ion, malate ion, hydroxyacetate ion, tartrate ion, acrylate ion, glutamate ion, lactate ion and the like. Alternatively, inorganic acids and organic acids similar to these can be used. Further, as a ligand which is useful for complex formation and forms an ammonia and amine complex, morpholine, ethylenediamine and the like or amines similar to these can be used. Examples of the polyvalent metal complex capable of exhibiting preferable performance in the present invention include zinc carbonate ammonia, calcium carbonate ethylenediamine-ammonia, zinc acetate ammonia, zinc acrylate ammonia, and the like. The composition of the present invention can be easily produced, for example, by stirring and mixing the aqueous solution containing the aqueous polyurethane-based resin and the aqueous solution of the polyvalent metal complex at normal temperature and normal pressure. It is essential that the polyvalent metal in the present invention forms a complex. That is, when a polyvalent metal that does not form a complex is added to an aqueous polyurethane-based resin containing a carboxyl group, the carboxyl group is easily crosslinked by the polyvalent metal, the viscosity increases with time, and the workability is increased. Getting worse. On the other hand, in the composition of the present invention, by containing a polyvalent metal used as a metal crosslinking agent as a polyvalent metal complex, the aqueous polyurethane-based resin can be present in a state of extremely excellent stability. The aqueous polyurethane resin used in the present invention may be, if necessary, an organic solvent, a pigment, a dye, an emulsifier, a surfactant, a thickener, a heat stabilizer, a leveling agent, an antifoaming agent, a filler, an anti-settling agent, and a UV absorber. Agents, antioxidants,
Thickeners and other conventional ingredients can be added.

[0011]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to the following Examples.
EXAMPLES Examples and comparative examples will be described, but the present invention is not limited to these examples. (Production of aqueous solution of polyvalent metal complex) Reference Example 1 54.0 g of water was placed in a container equipped with a stirrer, 10.0 g of zinc oxide was added with stirring, and zinc oxide was dispersed in water. Next, 18.0 g of 28% aqueous ammonia was added and stirring was continued until the mixture was dissolved to obtain an aqueous solution of ammonium zinc carbonate.
This aqueous zinc carbonate solution is designated as A-1. Reference Example 2 60.3 g of water was put in a container equipped with a stirrer, 10.0 g of calcium oxide was added with stirring, and calcium oxide was dispersed in water. Then, ammonium carbonate 14.3 g,
7.7 g of ethylenediamine and 28% aqueous ammonia 7.
Stirring was continued until 7 g was added and dissolved to obtain a calcium carbonate ethylenediamine aqueous solution. This calcium carbonate ethylenediamine aqueous solution is designated as A-2.

Reference Example 3 Into a vessel equipped with a stirrer, 55.0 g of water was added, and 15.0 g of zinc acetate was added with stirring to dissolve zinc acetate, and 30.0 g of 28% aqueous ammonia was further added and stirred until dissolved. Was continued to obtain a zinc acetate ammonia aqueous solution. This aqueous zinc acetate solution is designated as A-3. Reference Example 4 59.4 g of water was placed in a container equipped with a stirrer, 7.0 g of zinc oxide was added with stirring, and zinc oxide was dispersed in water. Subsequently, 12.6 g of acrylic acid was added to make zinc acrylate, 21.0 g of 28% aqueous ammonia was added, and stirring was continued until dissolution to obtain a zinc ammonium acrylate aqueous solution. This aqueous solution of zinc acrylate ammonium was used for A-4.
And

(Production of Aqueous Polyurethane Resin) Reference Example 5 83.7 g of polytetramethylene ether glycol having a molecular weight of 2,000 and 51.6 g of neopentyl glycol were placed in a 2000 ml four-necked flask equipped with a thermometer, a stirrer, and a nitrogen inlet tube. 4.2 g of trimethylolpropane, 21.5 g of dimethylolpropionic acid and 34.4 g of N-methyl-2-pyrrolidone were charged, and 90 ° C. while introducing nitrogen.
And the contents were dissolved. Next, the mixture was cooled to 40 ° C., 86.0 g of acetone was added, and when the internal temperature reached 30 ° C., 139.0 g of tolylene diisocyanate was added dropwise over 1 hour. After maintaining the internal temperature at 30 to 40 ° C. and performing the reaction for 8 hours, the mixture was diluted with 86.0 g of acetone. The NCO group content of this prepolymer was 0.90%.
481.5 g of deionized water containing 12.1 g of dimethylethanolamine was kept at 40 ° C.
An aqueous polyurethane resin was obtained by dropping and reacting 06.4 g. The aqueous polyurethane resin is further heated to 40 ° C.
, And finally a non-volatile content of 38.2 was obtained.
%, A pH of 7.6, an acid value of 30 KOH mg / g (in terms of solid content), and a viscosity of 400 cp / 25 ° C. to obtain an aqueous polyurethane resin. This aqueous polyurethane resin is designated as B-1.

Reference Example 6 In a 2000 ml four-necked flask equipped with a thermometer, a stirrer, and a nitrogen inlet tube, 83.7 g of polytetramethylene ether glycol having a molecular weight of 2000, 51.6 g of neopentyl glycol, 4.2 g of trimethylolpropane, 21.5 g of dimethylolpropionic acid and 34.4 g of N-methyl-2-pyrrolidone were charged, and 90 ° C. while introducing nitrogen.
And the contents were dissolved. Next, the mixture was cooled to 40 ° C., 86.0 g of acetone was added, and when the internal temperature reached 30 ° C., 139.0 g of tolylene diisocyanate was added dropwise over 1 hour. After maintaining the internal temperature at 30 to 40 ° C. and performing the reaction for 8 hours, the mixture was diluted with 86.0 g of acetone. The NCO group content of this prepolymer was 0.90%. Epicoat 1 was added to 506.4 g of the above prepolymer.
001 (manufactured by Shell Chemical Co., Ltd.) was charged and mixed. 481.5 g of deionized water containing 12.1 g of dimethylethanolamine was kept at 40 ° C., and a mixture of 506.4 g of the above prepolymer and 52.9 g of Epicoat 1001 (manufactured by Shell Chemical Co., Ltd.) was added dropwise. ° C
After performing decompression acetone under reduced pressure, the internal temperature was maintained at 70 to 80 ° C., and the reaction was carried out for 6 hours.
An aqueous polyurethane resin having a pH of 8.5, an acid value of 14 KOH mg / g (in terms of solid content), and a viscosity of 550 cp / 25 ° C. was obtained.
This aqueous polyurethane resin is designated as B-2.

Reference Example 7 In a 2000 ml four-necked flask equipped with a thermometer, a stirrer, and a nitrogen inlet tube, 37.9 g of polytetramethylene ether glycol having a molecular weight of 2,000, 23.4 g of neopentyl glycol, 1.9 g of trimethylolpropane, 78.9 g of dimethylolpropionic acid and 32.8 g of N-methyl-2-pyrrolidone were charged, and 90 ° C. while introducing nitrogen.
And the contents were dissolved. Next, the mixture was cooled to 40 ° C., 86.0 g of acetone was added, and when the internal temperature reached 30 ° C., 157.9 g of tolylene diisocyanate was added dropwise over 1 hour. After performing the reaction for 8 hours while maintaining the internal temperature at 30 to 40 ° C., the mixture was diluted with 86.0 g of acetone. The NCO group content of this prepolymer was 0.90%.
458.9 g of deionized water containing 44.5 g of dimethylethanolamine was kept at 40 ° C., and 496.7 g of the above prepolymer was added dropwise to obtain an aqueous polyurethane resin. This aqueous polyurethane resin is further
Deacetone was performed under reduced pressure at 0 ° C.
An aqueous polyurethane resin having a pH of 9%, a pH of 7.4, an acid value of 110 KOH mg / g (in terms of solid content), and a viscosity of 950 cp / 25 ° C. was obtained. This aqueous polyurethane resin is designated as B-3. The following were used as other additives. Acrylic emulsion; manufactured by Mitsui Toatsu Chemicals, Inc.
Acrylate emulsion having a trade name of Almatex K102, a non-volatile content of 42%, a viscosity of 2000 cps, and a pH of 8. Dispersant: Emulgen A-6 manufactured by Kao Corporation
0. Antifoaming agent; Nopco 803 (trade name, manufactured by San Nopco Co., Ltd.)
4-L.

Examples 1 to 6 The polyvalent metal complex aqueous solutions (A-1) prepared in Reference Examples 1 to 4
To 4) and aqueous polyurethane resins (B-1 to 3) synthesized in Reference Examples 5 to 7, titanium oxide CR-90 (manufactured by Ishihara Sangyo Co., Ltd.), additives and the like were blended in the proportions shown in Table 1, The pigment was dispersed for 1 hour using a paint shaker to obtain a base paint. After adjusting the viscosity of the obtained base paint, it was applied to a polished mild steel plate (JIS G3141) with a bar coater so that the dry film thickness became 20 μm. After drying at 80 ° C. for 10 minutes, it was left in a constant temperature and humidity room at a temperature of 20 ° C. and a humidity of 60% for 7 days to perform a performance test. The test method was performed according to JIS K5400. Table 2 shows the results.

Comparative Examples 1-4 Paints containing no polyvalent metal complex (Comparative Examples 1 and 3), paints containing an excess of polyvalent metal complex (Comparative Example 2), and paints containing an aqueous polyurethane resin having a high acid value (Comparative Example 4) is shown in Table 1.
And a base paint was obtained in the same manner as in Example. These paints were applied and tested for performance in the same manner as in the examples. Table 2 shows the results.

[0018]

[Table 1] (Note 1) Chemical equivalent to carboxyl group of polyvalent metal in polyvalent metal complex

[0019]

[Table 2]

Performance Test Method and Evaluation Criteria Adhesion: Cross-cut cellotape test according to JIS K5400 ○; 100/100 ×; 99 / 100-0 / 100 Warm water resistance: immersed in boiling water for 4 hours to observe the state of coating film ；: No abnormality ；: Partially whitened ×: Whole whitening, blister Moisture resistance: Observed state of coating film after standing at 50 ° C, 98% RH for 96 hours ；: No abnormality 一部: Partly whitened ×: Full surface Whitening, blister Salt spray test: Observe the state of the coating film after standing for 96 hours according to JIS K5400 ○: No abnormality △: Rust enters from cut part, whitens partially ×: Rust, whitens, blisters over the entire surface

[0021]

It is evident from Table 2 that the aqueous polyurethane resin composition obtained in the present invention is excellent in metal adhesion, hot water resistance, moisture resistance and salt spray resistance.

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification symbol FI C09D 175/04 C08K 5/15 (56) References JP-A-51-47027 (JP, A) JP-A-60-96655 (JP) , A) JP-A-6-200149 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C08L 75/04-75/12 C08G 18/00-18/87 C08K 3/24 , 5 / 15,5 / 56 C09D 175/04-175/12

Claims (1)

(57) [Claims] 1. A carboxyl group and / or carboxyl
Having an acid value of 10 to 100 KOHmg / g
(Solid content equivalent) polyurethane resin
Crosslinks 0.05 to 1.0 equivalents of polyvalent metal complex with respect to group
Aqueous polyurethane resin composition added as an
And the polyurethane resin is the polyurethane resin 10
Epoxy having two or more epoxy groups per 0 parts by weight
Gold containing 1 to 20 parts by weight of a compound
An aqueous polyurethane resin composition having excellent genus adhesion.