JP2938161B2 - Water-based polyurethane resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a paint having excellent elongation, strength and blocking properties.
The present invention relates to an aqueous polyurethane resin useful as an adhesive or the like.

[Conventional technology]

Aqueous polyurethane resin is used for paints, adhesives, etc., but the objects to be coated and adherends are plastics, metals,
There are a wide variety of paper and inorganic materials.

When an aqueous polyurethane resin is used as a material having flexibility and elongation among these materials, it is necessary to follow the material.

Conventionally, an aqueous polyurethane resin has been produced using a glycol having a large molecular weight, a glycol having a soft segment, and diisocyanate.

At this time, as the isocyanate, an aliphatic such as 1,6-hexamethylene diisocyanate and an alicyclic such as 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate were used. ,
Although the impact strength is good, the breaking strength and the blocking property are reduced.

Therefore, when used as a paint, paint film contamination,
Blocking occurs and does not function as a coating film.

In addition, when used as an adhesive, when the adherend is exposed to a high temperature state, there is a defect that the adhesive portion peels off and becomes loose, resulting in an adhesive having poor reliability.

[Problems to be solved by the invention]

As a result of intensive studies to solve the above problems, the present invention has found that 2,5- and / or
Or, an aqueous polyurethane resin using 2,6-diisocyanatomethylbicyclo [2,2,1] heptane has an elongation that can sufficiently follow a flexible material, and is a tough coating film with breaking strength. Thus, they found that they did not block against heat and were also excellent in solvent resistance, and finally completed the present invention.

[Means for solving the problem]

The present invention relates to an aqueous polyurethane resin characterized by using 2,5- and / or 2,6-diisocyanatomethylbicyclo [2,2,1] heptane (hereinafter abbreviated as BCHI) as a diisocyanate. Things.

The aqueous polyurethane resin used in the present invention is produced, for example, as follows.

A carboxyl group-containing urethane polymer having two or more isocyanate groups at the end obtained by reacting BCHI with a polyol having a carboxyl group and a polyol is used.

In the above reaction, the ratio of BCHI to the polyol having a carboxyl group and the polyol is such that the isocyanate group content (in terms of solid content) of the prepolymer is 0.5-1.
Adjust so that it becomes 0%.

In the above reaction, the amount of the polyol having a carboxyl group is suitably set so as to be 10 or more as an acid value (in terms of solid content).

The above-mentioned carboxyl group-containing urethane prepolymer can be produced in exactly the same manner as used in the production of ordinary polyurethane prepolymers.

BCHI used in the present invention is 2,5-diisocyanatomethylbicyclo [2,2,1] heptane, 2,6-diisocyanatomethylbicyclo [2,2,1] heptane or these 2,5-
And mixtures of 2,4-isomers can be used.

The above-mentioned BCHI is produced, for example, by the method of Japanese Patent Application No. 2-11801.

Any carboxyl group-containing polyols used in the present invention can be used as long as they impart a carboxyl group to the prepolymer molecule in a branched manner.However, in order to increase the carboxyl group content in the prepolymer, Those having a low molecular weight are preferred, and for example, 2,2-dimethylolpropionic acid and the like are preferred.

Further, as the polyols used in the present invention, known polyols usually used in the production of urethane resins, for example, diethylene glycol, butanediol, hexanediol, neopentyl glycol, bisphenol A, cyclohexanedimethanol, trimethylolpropane, 1 such as glycerin, pentaerythritol, polytetraethylene glycol, polyester polyol, polycaprolactone, tetramethylene ether glycol, polyether polyol, polyacetal polyol, polybutanediene polyol, furandumethanol, etc.
Species or a mixture of two or more species.

These polyols can be appropriately selected depending on the purpose and application, and the required physical properties such as hard and soft can be designed.

Production of the aqueous polyurethane resin used in the present invention,
The carboxyl group-containing urethane prepolymer is dissolved or suspended in the following solvent and / or water, and mixed with a basic organic compound (reacts with a carboxyl group to increase hydrophilicity).
And the following extender is added dropwise, or the basic organic compound and the extender are dissolved in a solvent and / or water, and a solution of the urethane prepolymer is added dropwise. At the same time, it is reacted with an elongating agent, then diluted with an appropriate amount of water, and dehydrated under reduced pressure until the nonvolatile content becomes 30 to 45%.
By removing the solvent, an aqueous polyurethane resin is obtained.

As the extender used in the present invention, water or polyamines are suitable, and as the polyamine, for example, ethylenediamine, diethylenetriamine, triethylenetetramine, propylenediamine, butylenediamine,
Hexamethylenediamine, cyclohexylenediamine,
Piperazine, 2-methylpiperazine, phenylenediamine, tolylenediamine, xylenediamine, α, α'-
Methylenebis (2-chloroaniline) 3,3'-dichloro-α, α'-biphenyldiamine, 2,6-diaminopyridine, α, α'-diaminodiphenylmethane, m-xylenediamine, isophoronediamine, N-methyl-3 ,
Adducts of 3'-diaminopropylamine, diethylenetriamine and acrylate or hydrolysis products thereof, and the like.

As the basic organic compound for imparting hydrophilicity by reacting with a carboxyl group, any known organic compound can be used, and particularly preferred examples include dimethylethanolamine, diethylethanolamine, and triethylamine. No.

Examples of the solvent used for resin production include, for example, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, toluene, xylene, isobutyl acetate, acetone,
Dimethylformamide, N-methyl-2-pyrrolidone, diethylene glycol dimethyl ether and the like are suitable.

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. It may contain other conventional components such as an agent, an antioxidant and a viscosity reducing agent.

The aqueous polyurethane resin obtained in the present invention can be used for blending with an acrylic emulsion or another aqueous resin.

In the aqueous polyurethane resin obtained in the present invention, for example, acrylic acid, acrylic acid ester, methacrylic acid,
At least one kind of vinyl monomer such as methacrylate, vinyl chloride, styrene, acrylonitrile, vinyl acetate and the like can be polymerized.

The aqueous polyurethane resin using the BCHI of the present invention as a diisocyanate component is more excellent in elongation, breaking strength and blocking properties than conventional ones, and is suitable as a paint or an adhesive.

〔Example〕

Hereinafter, in order to more specifically describe the present invention, a comparative example,
The present invention will be described by way of examples, but the present invention is not limited to these examples.

Production of BCHI Reference Example 1 As a solvent, 687 g of isoamyl acetate and 2189 g of o-dichlorobenzene (abbreviated as ODCB; the same applies hereinafter) were mixed to prepare a solvent for salt formation and phosgenation (hereinafter, referred to as a mixed solvent).

In this case, the ratio of the ODCB corresponding to the solvent isoamyl acetate is
76.1%.

1126 g of the mixed solvent was placed in a three-necked three-necked flask, and cooled to 5 ° C. with ice water while stirring.

Hydrogen chloride gas was blown into this at a rate of 1.6 Nl / min for 30 minutes, and then a separately prepared raw material diamine 2,5-isomer about 6
250.0 g (1.62 mol) of diaminomethyl-bicyclo [2,2,1] heptane (BHCA), which is a mixture of 0% and about 40% of the 2,6-isomer.
l) was dissolved in 1750 g of a mixed solvent (raw material diamine concentration: 12.5% by weight), and added dropwise to the liquid in the flask over 2 hours.

Cooling was continued during the dropping, and the temperature inside the flask was kept at 10 to 15 ° C.

The blowing of hydrogen chloride gas was continued at a rate of 1 Nl / min.

After completion of the dropwise addition of the starting diamine solution, blowing of hydrogen chloride gas was continued at a rate of 0.4 Nl / min for 2 hours while maintaining the temperature inside the flask at 25 ° C. or lower, to complete the salt formation reaction.

In the salt-forming reaction, agglomeration of hydrochloride particles did not occur, the transition was extremely smooth, and a slurry of white uniform fine particles was obtained.

After completion of the salt-forming reaction, the temperature inside the flask is increased from 25 ° C to 160 ° C by 5
While raising the temperature in 0 minutes, phosgene was gradually blown in from 100 ° C. to start the phosgenation reaction. Blowing of phosgene was continued at a rate of 100 g / h to 120 g / h while adjusting the internal temperature to 160 ± 1 ° C. with a mantle heater.

After about 6 hours from the start of phosgene blowing, the property of the reaction liquid changed from a slurry (white) to clear (red), and then phosgene gas was blown at a rate of 50 g / h for another 30 minutes, and then the phosgenation reaction was terminated. did. The phosgenation reaction time was 6.5 hours in total. The phosgene gas used was about 2.2 times the theoretical amount.

Thereafter, N ₂ gas was blown into the reaction solution in the flask at a rate of 1.3 Nl / min for 80 minutes to perform degassing. During this time, the liquid temperature was 16
0 ± 1 ° C. After the reaction solution was degassed and cooled to remove a trace amount of solids, the reaction solution was filtered through filter paper (5C).

After removing the solvent from the filtrate, rectification under vacuum was performed at 110 to 116 ° C /
306.5 g of a 0.4-0.6 torr main fraction was obtained.

 The analysis of this product was as follows.

NCO% 40.72 Hydrolysable chlorine (abbreviated as HC) 0.032% Gas chromatographic purity% 99.8 HC 0.202g / 100g-BCHI after desolvation Elemental analysis CHN Calculated% 64.06 6.84 13.58 Actual% 64.11 6.89 13.47 Elemental analysis, The main fraction obtained from the results of IR spectrum, NMR spectrum and the like was confirmed to be the target product. The yield of the main fraction was 91.7% of the theoretical value (1.62 mol, 334.2 g).

Example 1 2000 ml equipped with a thermometer, a stirrer, a cooling pipe, and a nitrogen introduction pipe
Q4646B (manufactured by Mitsui Toatsu Chemicals, Inc., polyester polyol, molecular weight 500) in a four-necked flask
0.7 g, trimethylolpropane 1.6 g, dimethylolpropionic acid 17.9 g, N-methyl-2-pyrrolidone 34.
3 g, 71.7 g of ethyl acetate, and BCHI obtained in Reference Example 1.
Was charged and reacted at 80 ° C. for 8 hours.

After the reaction, 100.0 g of ethyl acetate was added and diluted, and the isocyanate group content of the obtained prepolymer was 1.8%.

506.0 g of the above prepolymer, 13.3 g of triethylamine
After neutralization at 50 ° C., the mixture was poured into deionized water at 50 ° C. to obtain an aqueous polyurethane resin solution.

This aqueous polyurethane resin solution, 50 ° C. under reduced pressure,
De-ethyl acetate, non-volatile content 38.1%, PH 7.8, viscosity 4
An aqueous polyurethane resin of 50 CP / 25 ° C. was obtained.

Comparative Example 1 2000 ml equipped with a thermometer, a stirrer, a cooling pipe, and a nitrogen introduction pipe
Q4646B (Mitsui Toatsu Chemical Co., Ltd., polyester polyol, molecular weight 500) in a four-necked flask
4.5 g, trimethylolpropane 1.6 g, dimethylolpropionic acid 17.9 g, N-methyl-2-pyrrolidone 34.
3 g, 71.7 g of ethyl acetate and 126.1 g of isophorone diisocyanate were further charged, and the reaction was carried out at 80 ° C. for 8 hours. Then, 100.0 g of ethyl acetate was added and diluted.

The isocyanate group content of the obtained prepolymer is 1.
8%.

After neutralizing 506.0 g of the above prepolymer with 13.3 g of triethylamine, it was added to deionized water at 50 ° C. to obtain an aqueous polyurethane resin solution.

The aqueous polyurethane resin solution was subjected to ethyl acetate removal under reduced pressure at 50 ° C. to obtain a nonvolatile content of 37.5%, a pH of 7.8, and a viscosity of 6
An aqueous polyurethane resin of 30 CP / 25 ° C. was obtained.

Comparative Example 2 2000 ml equipped with a thermometer, a stirrer, a cooling pipe, and a nitrogen introduction pipe
Orester Q4646B (Mitsui Toatsu Chemical Co., Ltd., polyester polyol, molecular weight 500) in a four-necked flask
7.0 g, trimethylolpropane 1.8 g, dimethylolpropionic acid 17.9 g, N-methyl-2-pyrrolidone 34.
After 3 g, 71.7 g of ethyl acetate and 103.3 g of 1,6-hexamethylene diisocyanate were charged and reacted at 80 ° C. for 8 hours, 100.0 g of ethyl acetate was added and diluted. The isocyanate group content of the obtained prepolymer was 1.8%.

After neutralizing 506.0 g of the above prepolymer with 13.3 g of triethylamine, it was added to deionized water at 50 ° C. to obtain an aqueous polyurethane resin solution.

This aqueous polyurethane resin solution was subjected to deethylation at 50 ° C. under reduced pressure to obtain a nonvolatile content of 36.5%, a pH of 7.8, and a viscosity of 5
An aqueous polyurethane resin of 50 CP / 25 ° C. was obtained.

The aqueous polyurethane resins obtained in Comparative Examples 1 and 2 and Example 1 were dried and then coated on a tin plate to a thickness of 100 μm, and dried in a constant temperature and humidity room at a temperature of 20 ° C. and a humidity of 60% for 7 days. The coating film was peeled off, and the physical properties of the coating film were measured with a tensile tester.

Further, the steel sheet treated with zinc phosphate was dried so as to have a thickness of 10 μm, dried in a constant temperature and humidity room at a temperature of 20 ° C. and a humidity of 60% for 7 days, and then subjected to a performance test.

 The results are shown in Tables 1 and 2.

[Effects of the Invention] It is clear from Tables 1 and 2 that the aqueous polyurethane resin obtained in the present invention has an excellent balance between elongation and breaking strength and also has an excellent blocking property.

Continuation of the front page (58) Field surveyed (Int. Cl. ⁶ , DB name) C08G 18/75 C09D 175/04-175/12 C09D 5/00

Claims (5)

(57) [Claims] An aqueous polyurethane obtained by reacting a carboxyl group-containing urethane prepolymer comprising a carboxyl group-containing polyol and a diisocyanate with a basic organic compound and an extender in the presence of a solvent and / or water. In the resin, 2,5 as a diisocyanate
And / or 2,6-diisocyanatomethylbicyclo [2,
2,1] An aqueous polyurethane resin using heptane. 2. A polyol having a carboxyl group,
The aqueous polyurethane resin according to claim 1, which is 2,2-dimethylolpropionic acid. 3. The aqueous polyurethane resin according to claim 1, wherein the urethane prepolymer containing a carboxyl group contains 0.5 to 10.0% of an isocyanate group. 4. The aqueous polyurethane resin according to claim 1, wherein the basic organic compound is dimethylethanolamine, diethylethanolamine or triethylamine. 5. The aqueous polyurethane resin according to claim 1, wherein the extender is water or a polyamine.