JPH07268059A - Curative composition - Google Patents

Abstract

PURPOSE:To obtain a curative compsn. used for a coating material, excellent in workability, weatherability, and low-temp. storage stability, and low in toxicity by reacting-an alcohol having a specific alkyl group with an isocyanurate-type polyisocyanate. CONSTITUTION:This curative compsn. for a coating material comprises a modified polyisocyanate of the formula (wherein (m) and (n) are each an integer of 1 or higher provided 3<=m+n<=9 and 0.03<=n/(m+n)<=0.5; X is a residue of a diisocyanate polymer having isocyanurate rings in the molecule; and R is a 12-20C branched alkyl group) or its mixture. The modified polyisocyanate is obtd. pref. by reacting a diisocyanate polymer having isocyanurate rings in the molecule and derived from an aliph. and/or an alicyclic diisocyanate with a monohydric alcohol having a 12-20C branched alkyl group (e.g. isolauryl alcohol) in an equivalent ratio of the hydroxyl group to the free isocyanate group of 0.03-0.5.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a hardener composition. More specifically, the present invention relates to a curing agent composition for paints which comprises a modified polyisocyanate having low toxicity, excellent workability, weather resistance and low temperature storage stability.

[0002]

2. Description of the Related Art Conventionally, polyisocyanate has been widely used as a curing agent for polyols such as alkyd polyols and acrylic polyols in the coating field and coating field. It is generally known that a coating film obtained by using a polyisocyanate derived from an aliphatic and / or alicyclic diisocyanate among polyisocyanates as a curing agent has good weather resistance and durability. In particular, among the above polyisocyanates, polyisocyanates having an isocyanurate ring in the molecule have a highly stable chemical structure, and therefore, in comparison with conventional burette-type or adduct-type polyisocyanates, weather resistance, durability, etc. It is known to be excellent. Furthermore, for example, Japanese Examined Patent Publication No. 62-519
68, JP-A-62-209124 and JP-A-2-105812,
A resin composition has been proposed which comprises a polyisocyanate having an isocyanurate ring obtained by reacting a diisocyanate compound with a diol or a polyester polyol in the presence of an isocyanurate-forming catalyst, and a nonpolar organic solvent.

[0003]

However, these polyisocyanates having an isocyanurate ring are
Toluene, which is a polar solvent with high toxicity and high solubility,
It is necessary to use it after dissolving it in an organic solvent such as xylene or ethyl acetate. For this reason, there has been a big obstacle in terms of workability and safety. Further, in the above resin composition, in addition to the polyisocyanate having an isocyanurate ring, a reaction product of a diisocyanate compound and a diol or a polyester polyol remains as an unreacted product at the time of the isocyanurate-forming reaction due to its production method. Therefore, a coating film obtained by using the resin composition as a curing agent has a problem that the coating film hardness is lower than that of a coating film obtained by using a polyisocyanate having an ordinary isocyanurate ring. It was

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a curing agent composition obtained by reacting a monoalcohol having a specific alkyl group with an isocyanurate type polyisocyanate is obtained. The inventors have found that the above requirements can be met very effectively and have reached the present invention. That is, the present invention is represented by the following general formula [Wherein, m and n are integers of 1 or more, where 3 ≦ m + n ≦
9, 0.03 ≦ n / (m + n) ≦ 0.5], X represents a residue of a diisocyanate polymer having an isocyanurate ring in the molecule, and R represents a branched alkyl group having 12 to 20 carbon atoms. ] The hardening | curing agent composition for coating materials which consists of the modified polyisocyanate (A) shown by these or its mixture.

As the modified polyisocyanate (A) represented by the general formula (1), a diisocyanate polymer (a) having an isocyanurate ring in the molecule derived from an aliphatic and / or alicyclic diisocyanate is liberated. A modified polyisocyanate obtained by reacting 0.03 to 0.5 equivalent of a monoalcohol (b) having a branched alkyl group having 12 to 20 carbon atoms with 1 equivalent of an isocyanate group can be mentioned.

In the present invention, examples of the aliphatic diisocyanate constituting (a) include 1,6-hexamethylene diisocyanate, tetramethylxylylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, xylylene diisocyanate, Examples thereof include diethylbenzene diisocyanate. Further, examples of the alicyclic diisocyanate include 1,4-cyclohexane diisocyanate, 4,4′-diisocyanatodicyclohexylmethane, isopropylidenedidicyclohexyl-4,4′-diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanate). Natomethyl) cyclohexane and the like can be mentioned. Preferred among these are 1,6-hexamethylene diisocyanate, tetramethylxylylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane and 4,4′-diisocyanatodicyclohexylmethane. These can be used as a mixture of two or more kinds.

(A) is obtained by polymerizing one or more of the above diisocyanates by a conventional method using a known trimerization catalyst such as an alkali metal salt of an organic acid, and if necessary, by reacting unreacted diisocyanate by a method such as molecular distillation. It can be obtained by distilling off.

In the present invention, the monoalcohol (b) having a branched alkyl group has a carbon number of usually 12 to 20, preferably 16 to 18. When the branched alkyl group has less than 12 carbon atoms, it is difficult to dissolve in a nonpolar organic solvent,
When it exceeds 20, the solution dissolved in the nonpolar solvent becomes cloudy at a temperature of room temperature or lower, and further solidifies or separates at a temperature of 0 ° C. or lower, which is not preferable. On the other hand, a polyisocyanate obtained by reacting a monoalcohol having a linear alkyl group instead of a monoalcohol having a branched alkyl group is clouded at room temperature regardless of the number of carbon atoms, and is separated or solidified with time. In contrast to (b), a small amount of diol, triol, monoalcohol having a linear alkyl group or the like can be mixed or used in combination as long as the characteristics of the polyisocyanate of the present invention are not significantly impaired.

Specific examples of the monoalcohol (b) having the branched alkyl group include isolauryl alcohol (having 12 carbon atoms) and isomyristyl alcohol (having 1 carbon atoms).
4), isocetyl alcohol (16 carbon atoms), isostearyl alcohol (18 carbon atoms), isooleyl alcohol (18 carbon atoms) and the like. Of these, preferred are saturated alkyl alcohols, and particularly preferred are isocetyl alcohol and isostearyl alcohol.

In obtaining the modified polyisocyanate (A) of the present invention, the reaction temperature of the diisocyanate polymer (a) and the monoalcohol (b) having a branched alkyl group is
It is usually carried out at 60 to 120 ° C., preferably 80 to 100 ° C. The reaction can be carried out without solvent or in a system containing a solvent.

In the present invention, (m + n) indicating the number of functional groups in the modified polyisocyanate (A) represented by the general formula (1) is usually 3 to 9, preferably 3 to 6. When (m + n) is less than 3, the number of functional groups of the modified polyisocyanate is low and the performance such as mechanical properties and heat resistance of the coating film is impaired. When it is more than 9, the viscosity of the modified polyisocyanate obtained is high and it is used for paints. The coating workability when worn is deteriorated.

Further, in reacting the diisocyanate polymer (a) with the monoalcohol (b) having a branched alkyl group, a general formula (1) showing the equivalent ratio of the hydroxyl group of (b) and the free isocyanate group of (a) is obtained. ) N /
(M + n) is usually 0.03 to 0.5, preferably 0.
It is 03-0.33. When n / (m + n) is less than 0.03, the solubility of (A) in a non-polar solvent is deteriorated, resulting in 0.
When it exceeds 5, the number of functional groups of (A) decreases, so that the mechanical properties of the cured coating film deteriorate.

Nonpolar organic solvent (B) used in the present invention
Is a non-polar organic solvent having a low toxic and weak dissolving power, which is usually composed of an aliphatic and / or naphthenic hydrocarbon organic solvent and has an aniline point of usually 10 to 70 ° C., preferably 12 to 65 ° C. . As specific examples of the (B), House (manufactured by Shell Chemical Co., aniline point 15 ° C.), Swazol 310 (manufactured by Maruzen Petrochemical, aniline point 16 ° C.), Essonaphtha No. 6 (manufactured by Exxon Chemical, aniline point 43)
C.), Loose (manufactured by Shell Chemical Co., aniline point 43.degree. C.), Essonaphtha NO. 5 (manufactured by Exxon Chemical, aniline point 55)
C.), pegazole 3040 (manufactured by Mobil Petroleum, aniline point 55.degree. C.), and other commercially available petroleum hydrocarbon organic solvents.

The curing agent composition of the present invention may be used in a solventless form, but the modified polyisocyanate (A) and the nonpolar organic solvent (B) are (A) / (B) = 10 to 90. / 90
It can be used as a curing agent solution by mixing at an arbitrary ratio in the range of 10 to 10 (weight ratio). In the present invention,
If necessary, a polar organic solvent can be added to the curing agent composition comprising (A) and (B). In that case, in order not to impair the effects of the composition of the present invention as much as possible, the content of the polar organic solvent contained in the composition is kept to 30% by weight or less, preferably 15% by weight or less of the total organic solvent. There is a need. Examples of the polar organic solvent include ester solvents (ethyl acetate, butyl acetate, etc.), ketone solvents (methyl ethyl ketone, methyl isobutyl ketone, etc.),
Examples thereof include ether solvents (butyl cellosolve acetate etc.), aromatic solvents (low molecular weight substances such as xylene and toluene) and mixtures of two or more thereof.

Examples of the main component polyol to which the curing agent composition of the present invention is applied include polyols having two or more hydroxyl groups in one molecule, and specific examples include alkyd polyols, acrylic polyols and acrylated alkyd polyols. , Polyester polyol, polybutadiene polyol and the like. These polyols may contain a solvent, a pigment, a filler, an additive and the like. In particular, when the main component polyol is a non-aqueous dispersion dispersed in a non-polar organic solvent or a solution dissolved in a non-polar organic solvent, application of the curing agent composition of the present invention is extremely effective.

By using the curable composition of the present invention as a curing agent for paints, coating agents, etc., the working environment is remarkably improved as compared with the conventional case where a polar solvent having strong toxicity is used, and pollution and performance aspects are improved. It is possible to make a remarkable improvement also in. For example, when newly coating or repairing a coating film that is easily attacked by a polar solvent, the coating material containing the curing agent composition of the present invention can be lifted by the lifting (chijimi) ) Is not generated and a good coating film is provided.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited thereto. The parts and% in the examples are based on weight.

Production Example 1 Hexamethylene diisocyanate trimer (manufactured by Rhone-Poulin, trade name; "Tronate HD" was placed in a 4-neck glass flask equipped with a stirrer and a thermometer under a nitrogen gas atmosphere.
T "NCO% = 21.7%) 1749 parts, isostearyl alcohol [trade name; manufactured by Mitsubishi Kasei Co., Ltd .;" Diadol 18GT ", hydroxyl value = 200] 280 parts and" Swazol 310 "[hydrocarbon solvent] , Maruzen Petrochemical Co., Ltd.] 676 parts, and gradually stirred to 80
The temperature was raised to 0 ° C., and the temperature was maintained at the same temperature for 3 hours and then cooled to obtain a transparent polyisocyanate solution (D1) which is the objective resin composition of the present invention. The thus obtained (D1) has a nonvolatile content of 75.0%, a Hazen color number of 20, and a viscosity of 85 cps / 25.
C., NCO% = 13.2%, and the dilution ratio of the diluted solution with respect to “Swazol 310” was 2000% or more.

Production Example 2 In a 4-neck glass flask equipped with a stirrer and a thermometer, 1512 parts of "tronate HDT", isocetyl alcohol (manufactured by CONDEA, trade name; "ISOFOL16",
Hydroxyl value = 232) 242 parts and "Swazol 31
0 "585 parts were charged, the temperature was raised to 80 ° C. with gradual stirring, the temperature was maintained at the same temperature for 3 hours, and then the mixture was cooled to obtain a transparent polyisocyanate solution (D
2) was obtained. Thus obtained (D2) is a non-volatile component 7
5.0%, Hazen color number 20, viscosity 80 cps / 25
C., NCO% = 16.0%, and the dilution ratio of the diluted solution to “Swazol 310” was 2000% or more.

Production Example 3 In a 4-neck glass flask equipped with a stirrer and a thermometer, isophorone diisocyanate trimer (manufactured by Daicel-Huls, trade name; "IPDI-T1" under a nitrogen gas atmosphere.
890/100 "NCO% = 17.0%) 2226 parts,
Charge 280 parts of "Dia Doll 18GT" and 835 parts of "Swazol 310", and gradually stir 80
The temperature was raised to 0 ° C., and the temperature was maintained at the same temperature for 3 hours and then cooled to obtain a transparent polyisocyanate solution (D3) which was the objective resin composition of the present invention. The thus obtained (D3) has a nonvolatile content of 75.0%, a Hazen color number of 20, and a viscosity of 120 cps / 2.
The NCO% was 10.0% at 5 ° C, and the dilution ratio of the diluted solution with respect to "Swazol 310" was 2000% or more.

Production Example 4 Tetramethylxylylene diisocyanate (American Cy) was placed in a 4-neck glass flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and an air cooling tube under a nitrogen gas atmosphere.
manufactured by anamid Company, trade name; "m-T
MXDI ”) 1000 parts and charged with stirring at 60 ° C.
The temperature was raised to. Next, 0.75 parts of a 10% butyl cellosolve solution of potassium 2-ethylhexanoate was added as an isocyanurate-forming catalyst, followed by reacting for 3 hours at a temperature of 60 ° C., and then 1.0 part of a 5% butyl cellosolve solution of phosphoric acid was added. Then, the isocyanurate-forming catalyst was deactivated, and the isocyanurate-forming reaction was completed. After cooling the reaction mixture to room temperature, it was subjected to molecular distillation to give 520 parts of a polyisocyanate having an isocyanurate ring as an evaporation residue and tetramethylxylylene diisocyanate 480 as a distillate.
I got a part. 2160 parts of the obtained polyisocyanate having an isocyanurate ring, "Diadol 18GT" 2
80 parts and 813 parts of "Swazol 310" were charged into a reaction container similar to that in Production Example 1, and stirred gradually while
The temperature was raised to 0 ° C., and the temperature was maintained at the same temperature for 3 hours and then cooled to obtain a transparent polyisocyanate solution (D4) which was the objective resin composition of the present invention. The thus obtained (D4) has a nonvolatile content of 75.0%, a Hazen color number of 20, and a viscosity of 100 cps /
The NCO% was 10.3% at 25 ° C., and the dilution ratio of the diluted solution with respect to “Swazol 310” was 2000% or more.

Production Example 5 In a 4-neck glass flask equipped with a stirrer, a thermometer, a nitrogen introducing tube and an air cooling tube, 1.3-bis (isocyanatomethyl) cyclohexane [Takeda Yakuhin K.K. ), Trade name; "Takenate 600"] was charged, and the temperature was raised to 60 ° C with stirring. Next, 0.75 parts of a 10% butyl cellosolve solution of potassium 2-ethylhexanoate was added as an isocyanurate-forming catalyst, and after reacting at a temperature of 60 ° C. for 3 hours, 5% of phosphoric acid was added.
The isocyanurate-forming catalyst was deactivated by adding 1.0 part of a butyl cellosolve solution to complete the isocyanurate-forming reaction. The reaction mixture was cooled to room temperature and then subjected to molecular distillation to obtain 450 parts of polyisocyanate having an isocyanurate ring as an evaporation residue and 550 parts of tetramethylxylylene diisocyanate as a distillate. Obtained polyisocyanate having isocyanurate ring 1746
Parts, 280 parts of "Diadol 18GT" and 675 parts of "Swazol 310" are charged in the same reaction container as in Production Example 1, gradually heated to 80 ° C. with stirring, kept at the same temperature for 3 hours, and then cooled. Then, a transparent polyisocyanate solution (D5) which is the objective resin composition of the present invention was obtained. The thus obtained (D5) had a nonvolatile content of 75.0%, a Hazen color number of 20, a viscosity of 65 cps / 25 ° C., and an NCO% of 13.
6%, and the dilution ratio of the diluted solution with respect to "Swazol 310" was 2000% or more.

Production Example 6 In a 4-neck glass flask equipped with a stirrer, a thermometer, a nitrogen introducing tube and an air cooling tube, 4.4'-diisocyanate-dicyclohexylmethane (manufactured by Sumitomo Bayer Urethane Co., Ltd.) under a nitrogen gas atmosphere. , Product name; "Desmodur W")
1000 parts were charged and the temperature was raised to 60 ° C. with stirring.
Next, 0.75 parts of a 10% butyl cellosolve solution of potassium 2-ethylhexanoate was added as an isocyanurate-forming catalyst, and after the reaction was continued at a temperature of 60 ° C. for 3 hours,
The isocyanurate-forming reaction was terminated by adding 1.0 part of a 5% butyl cellosolve solution of phosphoric acid to deactivate the isocyanurate-forming catalyst. The reaction mixture was cooled to room temperature and then subjected to molecular distillation to obtain 420 parts of a polyisocyanate having an isocyanurate ring as an evaporation residue and 580 parts of tetramethylxylylene diisocyanate as a distillate. 2358 parts of the obtained polyisocyanate having an isocyanurate ring, 280 parts of "Diadol 18GT" and 879 parts of "Swazol 310" were charged into a reaction vessel similar to that in Example 1, and the temperature was raised to 80 ° C while gradually stirring. Then
After being kept at the same temperature for 3 hours, it was cooled to obtain a transparent polyisocyanate solution (D6) which was the objective resin composition of the present invention. Polyisocyanate solution (D6) thus obtained
Is non-volatile 75.0%, Hazen color number 20, viscosity 135
cps / 25 ° C., NCO% = 9.6%, and the dilution ratio with respect to the diluted solution Swazol 310 was 2000% or more.

Comparative Production Example 1 A four-neck glass flask equipped with a stirrer and a thermometer was charged with 750 parts of hexamethylene diisocyanate trimer (trade name: "Tronate HDT" manufactured by Rhone-Poulin) and 250 parts of "Swazol 310". After charging, the temperature was raised to 80 ° C. with gradual stirring, and cooling was started when the temperature became uniform. However, this solution became cloudy as the temperature decreased, and when left standing, it separated into two layers.

Comparative Production Example 2 Isophorone diisocyanate trimer (trade name; IPDI-T1890 / 1, manufactured by Daicel Hüls) was placed in a 4-neck glass flask equipped with the same equipment as in Comparative Production Example 1.
00]) and 250 parts of “Swazol 310” were charged, the temperature was raised to 80 ° C. with gradual stirring, and when uniform, cooling was started. However, the solution became cloudy as the temperature decreased and separated into two layers when left standing.

Examples 1 to 6 Polyisocyanate solutions (D) obtained in Production Examples 1 to 6
1) to (D6) are safflower oil-modified middle oil alkyd resin [manufactured by Dainippon Ink and Chemicals, Inc., trade name; "Beckosol J-557", nonvolatile content = 50 ± 1%, solvent; "Swazol 310", Hydroxyl value (measured value) 60, acid value 8 or less)
Table 1 shows the results of coating a glass plate with a resin varnish prepared by blending the same amount so that NCO / OH = 1, and the hardness of the obtained coating film. Further, Table 1 shows the results of the coating film surface state when the above resin varnish was applied over the cured coating film of the long oil alkyd resin enamel.

Comparative Example 1 Hexamethylene diisocyanate trimer (manufactured by Rhone Poulenc Co., Ltd., was used for the safflower oil-modified medium oil alkyd resin “Beckosol J-557” used in Examples 1-6.
Product name; "Tronate HDT"), NCO / OH = 1
Table 1 shows the results of coating a glass plate with a resin varnish prepared by blending the same amount so that

Comparative Example 2 Isophorone diisocyanate trimer (manufactured by Daicel Hüls Ltd., trade name: “IPDI-T1890 / 100”) was added to “Beccosol J-557” in NCO /
Table 1 shows the results of coating a glass plate with a resin varnish prepared by blending so that OH = 1.

Comparative Example 3 A petroleum hydrocarbon solvent-soluble polyisocyanate [manufactured by Dainippon Ink and Chemicals, Inc., trade name; "Bernock DN / 990"] was used against "Beccosol J-557".
Table 1 shows the results of coating a glass plate with a resin varnish prepared by blending the same amount so that NCO / OH = 1 and the hardness of the obtained coating film.

[0030]

[Table 1]

[0031]

The curing agent composition of the present invention has the following effects. (1) It has low toxicity and good solubility in a weakly polar hydrocarbon-based non-polar organic solvent. As a result, the working environment, air pollution, etc. are significantly improved. (2) A coating film having excellent curability and good physical properties is provided. (3) Lifting does not occur even when paint is applied over the coating film. From the above effect, the curing agent composition of the present invention,
In particular, it is extremely useful as a curing agent for paints (for example, non-aqueous dispersion type paints) containing a non-polar organic solvent as a main dilution medium.

Claims (4)

[Claims] 1. The following general formula [Wherein, m and n are integers of 1 or more, where 3 ≦ m + n ≦
9, 0.03 ≦ n / (m + n) ≦ 0.5], X represents a residue of a diisocyanate polymer having an isocyanurate ring in the molecule, and R represents a branched alkyl group having 12 to 20 carbon atoms. ] The hardening | curing agent composition for coating materials which consists of the modified polyisocyanate (A) shown by these or its mixture. 2. The amount of (A) is 0.03 relative to 1 equivalent of the free isocyanate group of the diisocyanate polymer (a) having an isocyanurate ring in the molecule derived from an aliphatic and / or alicyclic diisocyanate. The composition according to claim 1, which is a modified polyisocyanate obtained by reacting ??? 0.5 equivalent of a monoalcohol (b) having a branched alkyl group having 12 to 20 carbon atoms. 3. (a) is selected from 1,6-hexamethylene diisocyanate, isophorone diisocyanate, tetramethylxylylene diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane and 4,4′-diisocyanate-dicyclohexylmethane. A composition according to claim 1 or 2 which is a diisocyanate polymer derived from at least one diisocyanate. 4. The composition according to claim 1, which is dissolved in a non-polar organic solvent (B) having an aniline point of 10 to 70 ° C.