JP2009149786A - Terminator composition for allophanatization reaction and method for producing allophanate-modified polyisocyanate using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a terminator composition for allophanatization reaction preventing liquid turbidity of an allophanate-modified polyisocyanate produced using the composition and improving the degree of dilution of the allophanate-modified polyisocyanate with a solvent and to provide a method for producing an allophanate-modified polyisocyanate using the composition. <P>SOLUTION: The method for producing the allophanate-modified polyisocyanate comprises reacting a polyisocyanate with an alcohol in the presence of an allophanatization catalyst and then adding a reaction terminator wherein as the reaction terminator, a composition for terminating allophanatization reaction which comprises phosphoric acid and an alkylbenzene sulphonate in a ratio (by mass) of an alkylbenzene sulphonate to phosphoric acid of at least 2.5 is used. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an allophanatization reaction terminator composition and a method for producing an allophanate-modified polyisocyanate using the same.

Conventionally, polyisocyanate curing agents have been widely used as curing agents for paints and adhesives.
In particular, a polyisocyanate having an isocyanurate group is known to be a curing agent that gives a coating film having excellent weather resistance, heat resistance and durability, but this polyisocyanate has a very high solubility in an organic solvent. There is also a problem that the viscosity is high.

In order to solve these problems, it has recently been proposed to use allophanate-modified polyisocyanates.
This allophanate-modified polyisocyanate is generally produced by reacting a polyisocyanate and an alcohol in the presence of an allophanate catalyst such as a carboxylic acid metal salt (see, for example, Patent Documents 1 to 4). At this time, inorganic acids such as phosphoric acid and hydrochloric acid, and organic acids such as sulfonic acid are used as the reaction terminator.

However, when these conventional reaction terminators are used, there are problems that the obtained allophanate-modified polyisocyanate causes liquid turbidity and solvent dilutability.
In particular, these problems are remarkable in the case of a polyfunctional allophanate using a low molecular polyol having a small number of carbon atoms in the side chain.

Japanese Patent No. 3940801 JP 2002-338655 A JP 2005-15378 A Japanese Patent No. 3850895

  The present invention has been made in view of the above circumstances, and an allophanatization reaction terminator composition capable of suppressing liquid turbidity of an allophanate-modified polyisocyanate obtained using the same and improving the solvent dilutability. It is an object to provide a product and a method for producing an allophanate-modified polyisocyanate using the product.

  As a result of intensive studies to achieve the above object, the inventor of the present invention uses a composition obtained by mixing alkylbenzenesulfonic acid and phosphoric acid at a predetermined ratio as an allophanatization reaction terminator. It was found that the liquid turbidity of the allophanate-modified polyisocyanate, which has been a problem with the terminator, can be suppressed, and the solvent dilutability can be improved, and the present invention has been completed.

That is, the present invention
1. An allophanatization reaction terminator composition comprising phosphoric acid and alkylbenzenesulfonic acid in an alkylbenzenesulfonic acid / phosphoric acid = 2.5 or more (mass ratio);
2. 1 allophanation reaction terminator composition, wherein the alkylbenzenesulfonic acid is an alkylbenzenesulfonic acid having 10 to 16 carbon atoms,
3. In the method for producing an allophanate-modified polyisocyanate in which a polyisocyanate and an alcohol are reacted in the presence of an allophanation catalyst and then a reaction stopper is added, as the reaction stopper, 1 or 2 allophanation reaction stopper Provided is a method for producing an allophanate-modified polyisocyanate characterized by using a composition.

  Since the allophanate reaction terminator composition of the present invention contains phosphoric acid and alkylbenzene sulfonic acid in a predetermined ratio, it can suppress liquid turbidity of the obtained allophanate-modified polyisocyanate and increase its solvent dilutability. it can.

Hereinafter, the present invention will be described in more detail.
The allophanatization reaction terminator composition according to the present invention comprises phosphoric acid and alkylbenzene sulfonic acid at an alkylbenzene sulfonic acid / phosphoric acid = 2.5 or more (mass ratio).
Here, when the mixing ratio is less than 2.5, the effect of using alkylbenzenesulfonic acid and phosphoric acid together, that is, the effect of suppressing the liquid turbidity of the obtained allophanate-modified polyisocyanate is not sufficiently exhibited.
In consideration of exhibiting a more excellent liquid turbidity suppressing effect, the mixing ratio of phosphoric acid and alkylbenzenesulfonic acid is preferably alkylbenzenesulfonic acid / phosphoric acid = 2.7 or more (mass ratio). More preferably, it is 0 or more. On the other hand, the upper limit is not particularly limited, but is preferably 4.0 or less, and more preferably 3.5 or less.

The alkylbenzenesulfonic acid that can be used in the allophanatization reaction terminator composition of the present invention is not particularly limited, and may be appropriately selected from conventionally known ones.
Specific examples thereof include decyl benzene sulfonic acid, undecyl benzene sulfonic acid, dodecyl benzene sulfonic acid, tridecyl benzene sulfonic acid, tetradecyl benzene sulfonic acid and the like. These may be used alone or in combination of two or more. May be used.
Among these, in consideration of further improving the effect of improving the liquid turbidity and solvent dilution, C10-16 alkylbenzene sulfonic acid is preferable. Specifically, Neoperex GS (manufactured by Kao Corporation) and Raipon LH -200 (manufactured by Lion Corporation).
On the other hand, as phosphoric acid, it is preferable to use a general 75-85 mass% aqueous solution.

An organic solvent may be added to the allophanatization reaction terminator composition of the present invention as necessary.
The organic solvent is not particularly limited as long as it is compatible with alkylbenzene sulfonic acid and phosphoric acid. For example, ester solvents such as ethyl acetate and butyl acetate, ketone solvents such as acetone and methyl ethyl ketone, tetrahydrofuran And ether solvents such as (THF).
The amount of the organic solvent to be used is not particularly limited, but is preferably an amount in which the total amount of alkylbenzenesulfonic acid and phosphoric acid is about 20 to 80% by mass in the composition.

The method for producing an allophanate-modified polyisocyanate according to the present invention is characterized by using the above-described allophanate reaction stopper composition.
That is, in the method for producing a general allophanate-modified polyisocyanate comprising a series of steps of reacting a polyisocyanate and an alcohol in the presence of an allophanate catalyst and then adding a reaction terminator, the above-described allophanate formation is performed. A reaction terminator composition is used.

  As the polyisocyanate for forming allophanate, it can be appropriately selected from conventionally known polyisocyanates, for example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate. 2,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane 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, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1, -Aromatic isocyanates such as diisocyanate, naphthylene-1,5-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate; hexamethylene diisocyanate, 1,4-tetramethylene diisocyanate, 2-methylpentane-1, Aliphatic isocyanates such as 5-diisocyanate and lysine diisocyanate; Aroaliphatic diisocyanates such as xylylene-1,4-diisocyanate and xylylene-1,3-diisocyanate; Isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene diisocyanate, hydrogenated Examples thereof include alicyclic diisocyanates such as diphenylmethane diisocyanate and hydrogenated tetramethylxylene diisocyanate. These organic diisocyanates may be used alone or in the form of a mixture of two or more.

  On the other hand, the alcohol is not particularly limited. For example, monools such as methanol, ethanol, n-propanol, i-propanol, n-butanol, i-butanol, and t-butanol; ethylene glycol, 1, 2 -Propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 1,8-octanediol, 1,9-nonanediol, 2,2-diethyl-1,3-propanediol, 2 -N-butyl-2-ethyl-1,3-propanediol, 2,2,4-trimethyl-1,3-penta Diol, 2-ethyl-1,3-hexanediol, 2-n-hexadecane-1,2-ethylene glycol, 2-n-eicosane-1,2-ethylene glycol, 2-n-octacosane-1,2-ethylene Glycol, diethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, ethylene oxide or propylene oxide adduct of bisphenol A, hydrogenated bisphenol A, 3-hydroxy-2,2-dimethylpropyl-3-hydroxy-2, Diols such as 2-dimethylpropionate; and triols such as trimethylolpropane and glycerin. These may be used alone or in combination of two or more.

  When the allophanation reaction terminator composition of the present invention is used, liquid turbidity of a polyfunctional allophanate obtained by using a low molecular polyol having a molecular weight of 150 or less and a total number of carbon atoms in the side chain of 4 or less is effectively suppressed. Is done. In the case of monools such as methanol and polymer polyols such as polypropylene glycol, the problem of liquid turbidity does not occur even if the allophanatization reaction terminator composition of the present invention is not used.

The allophanatization reaction can be performed by heating the polyisocyanate and alcohol as described above to about 50 to 150 ° C. in the presence or absence of an organic solvent.
Allophanatization may be performed simultaneously with urethanization or after urethanization. When urethanization and allophanatization are performed simultaneously, the reaction may be performed in the presence of an allophanatization catalyst. When allophanatization is performed after urethanization, the urethanization reaction was performed for a predetermined time in the absence of the allophanatization catalyst. Thereafter, an allophanatization catalyst may be added to carry out the allophanatization reaction.

As the allophanatization catalyst, a known catalyst can be appropriately selected and used. For example, a metal salt of an organic carboxylic acid can be used.
Examples of the organic carboxylic acid include saturated aliphatic carboxylic acids such as acetic acid, propionic acid, butyric acid, caproic acid, octylic acid, lauric acid, myristic acid, palmitic acid, stearic acid, and 2-ethylhexanoic acid; cyclohexanecarboxylic acid, Saturated cycloaliphatic carboxylic acids such as cyclopentanecarboxylic acid; saturated bicyclic carboxylic acids such as bicyclo (4.4.0) decane-2-carboxylic acid; oleic acid, linoleic acid, linolenic acid, soybean oil fatty acid, tall oil Examples thereof include unsaturated aliphatic carboxylic acids such as fatty acids; aromatic aliphatic carboxylic acids such as diphenylacetic acid; aromatic carboxylic acids such as benzoic acid and toluic acid.
The metal constituting the metal salt of carboxylic acid includes alkali metals such as lithium, sodium and potassium; alkaline earth metals such as magnesium, calcium and barium; manganese, iron, cobalt, nickel, copper, zinc and zirconium Transition metals and the like.
Of these, metal salts of alkylcarboxylic acid such as zirconium, zinc and lead are preferable, and zirconium salts of alkylcarboxylic acid such as zirconium octylate and zirconium 2-ethylhexanoate are particularly preferable.
In addition, 0.0005-1 mass% is preferable with respect to the total mass of polyisocyanate and alcohol, and, as for the usage-amount of an allophanatization catalyst, 0.001-0.1 mass% is more preferable.

  When the reaction is performed in the presence of an organic solvent, various organic solvents that do not affect the reaction can be used. Specific examples thereof include aliphatic hydrocarbons such as n-hexane and octane, cyclohexane, methylcyclohexane, and the like. Alicyclic hydrocarbons, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketones, methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate esters, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, Glycol ether esters such as 3-methyl-3-methoxybutyl acetate and ethyl-3-ethoxypropionate, ethers such as diethyl ether, tetrahydrofuran and dioxane, methyl chloride, methylene chloride, chloroform and tetrasalt Carbon, methyl bromide, methylene iodide, halogenated hydrocarbons dichloroethane, N- methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, polar aprotic solvents such as hexamethylphosphoric phosphonyl amides. These solvents can be used alone or in combination of two or more.

After completion of the reaction, the above-mentioned reaction terminator containing alkylbenzene sulfonic acid and phosphoric acid is added to the reaction system, and the reaction is stopped at 80 to 100 ° C. for 1 to 2 hours to stop the allophanatization reaction.
At this time, the amount of the reaction terminator used is not particularly limited, but it is preferably used in such an amount that phosphoric acid becomes 2 equivalents with respect to the allophanatization catalyst.
After termination of the reaction, the desired allophanate-modified polyisocyanate can be obtained by removing unreacted components by a known method such as thin film distillation.

  EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated more concretely, this invention is not limited to the following Example. In the following, the viscosity is a value measured with a B-type rotational viscometer.

[Example 1]
In a 1-liter four-necked flask equipped with a stirrer, a thermometer, a condenser tube, and a nitrogen gas inlet tube, 950 g of hexamethylene diisocyanate (NCO content: 49.9% by mass) and 3-methyl-1,5 -50 g of pentanediol were charged and these were heated to 60 ° C with stirring. After reaching 60 ° C., 0.1 g of zirconium octylate (Zr content: 12 mass%) as a urethanization / allophanate catalyst was added. Immediately after the addition of the catalyst, the reaction solution generated heat and rose to around 90 ° C. After the exotherm had subsided, the reaction solution was heated to 110 ° C., held at this temperature for 2 hours, and then heated to 120 ° C. for reaction for about 1 hour.
Thereafter, 0.18 g of a 50 mass% ethyl acetate solution of phosphoric acid / Neopelex GS (mixed solution of alkylbenzene sulfonic acid manufactured by Kao Corporation) (mixed solution of 1/3 by mass) as a reaction terminator was added to the reaction solution. And stopped at 50 ° C. for 1 hour. The NCO content of the reaction solution after stopping was 40.2% by mass.
Excess hexamethylene diisocyanate was removed from this reaction product by thin-film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 19.2% by mass, viscosity (25 ° C.) 2,200 mPa · s, free hexamethylene. An allophanate-modified polyisocyanate having a methylene diisocyanate content of 0.1% by mass was obtained.

[Comparative Example 1]
The allophanatization reaction was performed in the same manner as in Example 1 except that 0.15 g of a 20% by mass ethyl acetate solution of phosphoric acid was used as a reaction terminator. The NCO content of the reaction liquid after stopping was 40.1% by mass.
Excess hexamethylene diisocyanate was removed from this reaction product by thin film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 19.2% by mass, viscosity (25 ° C.) 2,300 mPa · s, free hexamethylene. An allophanate-modified polyisocyanate having a methylene diisocyanate content of 0.1% by mass was obtained.

[Comparative Example 2]
The allophanatization reaction was performed in the same manner as in Example 1 except that 0.15 g of a 50 mass% ethyl acetate solution of Neoperex GS was used as a reaction terminator. The NCO content of the reaction solution after stopping was 40.2% by mass.
Excess hexamethylene diisocyanate was removed from this reaction product by thin film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 19.2% by mass, viscosity (25 ° C.) 2,300 mPa · s, free hexamethylene. An allophanate-modified polyisocyanate having a methylene diisocyanate content of 0.1% by mass was obtained.

[Comparative Example 3]
The allophanatization reaction was carried out in the same manner as in Example 1 except that 0.18 g of a 50% by mass ethyl acetate solution of phosphoric acid / Neopelex GS (mixed solution having a mass ratio of 1 / 2.4) was used as the reaction terminator. went. The NCO content of the reaction solution after stopping was 40.2% by mass.
Excess hexamethylene diisocyanate was removed from this reaction product by thin film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 19.2% by mass, viscosity (25 ° C.) 2,300 mPa · s, free hexamethylene. An allophanate-modified polyisocyanate having a methylene diisocyanate content of 0.1% by mass was obtained.

[Comparative Example 4]
The allophanatization reaction was performed in the same manner as in Example 1 except that 0.15 g of a 50% by mass ethyl acetate solution of phosphoric acid / Neopelex GS (1 / 1.2 mixed solution) was used as the reaction terminator. . The NCO content of the reaction liquid after stopping was 40.1% by mass.
Excess hexamethylene diisocyanate was removed from this reaction product by thin film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 19.2% by mass, viscosity (25 ° C.) 2,300 mPa · s, free hexamethylene. An allophanate-modified polyisocyanate having a methylene diisocyanate content of 0.1% by mass was obtained.

[Comparative Example 5]
The allophanatization reaction was carried out in the same manner as in Example 1 except that 0.11 g of a phosphoric acid monoester / diester mixture (2-ethylhexyl ester) (JP-508, manufactured by Johoku Chemical Co., Ltd.) was used as a reaction terminator. Went. The NCO content of the reaction solution after stopping was 40.2% by mass.
Excess hexamethylene diisocyanate was removed from this reaction product by thin-film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 19.3% by mass, viscosity (25 ° C.) 2,200 mPa · s, free hexamethylene. An allophanate-modified polyisocyanate having a methylene diisocyanate content of 0.1% by mass was obtained.

[Comparative Example 6]
The allophanatization reaction was performed in the same manner as in Example 1 except that 0.13 g of phosphoric acid diester (2-ethylhexyl ester) (LB-58R, manufactured by Johoku Chemical Industry Co., Ltd.) was used as the reaction terminator. The NCO content of the reaction liquid after stopping was 40.1% by mass.
Excess hexamethylene diisocyanate was removed from this reaction product by thin film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 19.2% by mass, viscosity (25 ° C.) 2,300 mPa · s, free hexamethylene. An allophanate-modified polyisocyanate having a methylene diisocyanate content of 0.1% by mass was obtained.

[Comparative Example 7]
The allophanatization reaction was performed in the same manner as in Example 1 except that the reaction terminator was not used. The NCO content of the reaction solution after the reaction was 40.0% by mass.
Excess hexamethylene diisocyanate was removed from this reaction product by thin film distillation (conditions: 140 ° C., 0.04 kPa), NCO content 19.3% by mass, viscosity (25 ° C.) 2,400 mPa · s, free hexamethylene. An allophanate-modified polyisocyanate having a methylene diisocyanate content of 0.1% by mass was obtained.

Using the allophanate-modified polyisocyanate obtained in Example 1 and Comparative Examples 1 to 7, the stopping effect of the reaction terminator, liquid turbidity, and solvent dilutability were measured and evaluated by the following methods. The results of the stopping effect and liquid turbidity are shown in Table 1, and the results of solvent dilution are shown in Table 2.
(1) Stop effect About the obtained allophanate modified polyisocyanate, the storage stability after one month at 50 degreeC was measured, and the following method evaluated.
(Circle): A remarkable NCO fall and thickening are not recognized x: A remarkable NCO fall and thickening are recognized (2) Liquid turbidity About the obtained allophanate modified polyisocyanate, turbidity was measured according to JISK0101.
(Circle): Clear x: Turbidity 2 or more (3) Solvent dilution The ethyl acetate solution was prepared and the solvent dilution was evaluated by the turbidity. The solid content (concentration) of the ethyl acetate solution was evaluated at three levels of 80 mass%, 60 mass%, and 40 mass%. The method for measuring turbidity is as described above.

As shown in Table 1, in Example 1, phosphoric acid / alkylbenzene sulfonic acid (Neopelex GS) (mixed solution having a mass ratio of 1/3) was used as a terminator. It can be seen that the liquid turbidity of the isocyanate is suppressed. Moreover, it turns out that this polyisocyanate also has favorable solvent dilutability.
In contrast, Comparative Examples 1, 5, and 6 using phosphoric acid and phosphoric acid ester alone, and Comparative Examples 3 and 4 using phosphoric acid and alkylbenzenesulfonic acid at a mixing ratio outside the range defined in the present invention. Then, it turns out that liquid turbidity has occurred.
Moreover, when alkyl benzenesulfonic acid is used independently (comparative example 2), it turns out that the stop effect is inadequate.

Claims (3)

  An allophanatization reaction terminator composition comprising phosphoric acid and alkylbenzenesulfonic acid in an alkylbenzenesulfonic acid / phosphoric acid = 2.5 or more (mass ratio).   The allophanatization reaction terminator composition according to claim 1, wherein the alkylbenzenesulfonic acid is an alkylbenzenesulfonic acid having 10 to 16 carbon atoms. In the process for producing an allophanate-modified polyisocyanate in which a reaction stopper is added after reacting a polyisocyanate with an alcohol in the presence of an allophanate catalyst,
A method for producing an allophanate-modified polyisocyanate, characterized in that the allophanate reaction terminator composition according to claim 1 or 2 is used as the reaction terminator.