JP5476962B2 - Process for producing acylurea-modified polyisocyanate composition - Google Patents

Description

  The present invention relates to a method for producing an acylurea-modified polyisocyanate composition. More specifically, the present invention relates to a method for producing an acylurea-modified polyisocyanate composition that substantially contains no urethane group, uretdione group, and isocyanurate group and has a transparent appearance.

  Various methods for producing acylurea-modified polyisocyanates have been known. For example, Non-Patent Document 1 and Non-Patent Document 2 describe synthesizing an acyl urea group-containing isocyanate polyaddition product by a direct reaction between an isocyanate and a carboxylic acid or via a carbodiimide intermediate. .

Patent Document 1 discloses a reaction product of a carboxylic acid group-containing polyalkylene oxide polyether. A polyalkylene oxide polyether is converted into a lacquer polymer by a reaction between an acylated urea group or an isocyanate group forming an amide bond and a carboxylic acid group. The water dispersible polyisocyanate mixture combined with isocyanate is described.
However, in the method of Patent Document 1, a water-dispersible polyisocyanate obtained from a polyisocyanate obtained by mixing a polyalkylene oxide polyether from an acylated urea group-containing isocyanate with an isocyanate-modified product such as a uretdione group, an isocyanurate group, or an allophanate group. This relates to a mixture, and there is almost no description regarding a method for producing an acylurea-modified polyisocyanate composition.

Patent Document 2 describes a method for producing an acylurea group-containing polyisocyanate, in which an isocyanate and a carboxylic acid are reacted in the presence of a metal salt catalyst to obtain a colorless non-foamed product such as polyisocyanate.
However, Patent Document 2 is a reaction between an aliphatic / aromatic carboxylic acid and a polyisocyanate, and the reaction time becomes considerably long.

Liebigs Ann. Chem. , 1976, Vol. 3, Page 487-495 Recl. Trav. Chim. Pay-Bas, 1992, 111, Page 89-91.

JP 2001-233930 A JP 2003-002873 A

  An object of the present invention is to provide a method for producing an acylurea-modified polyisocyanate composition with a small catalyst amount.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a specific monocarboxylic acid and a metal salt catalyst, and have completed the present invention.
That is, this invention is shown by the following (1)- (3) .

(1) A method of manufacturing a acylurea modified polyisocyanate compositions, the carboxyl group-containing compound from (A), organic diisocyanate (B) and acylurea catalyst (C), a method of manufacturing the acylurea modified polyisocyanate compositions, acylurea The oxidation catalyst (C) is zirconium octylate, and the catalyst poison (D) is used to stop the acylureaization reaction .

(2) the organic diisocyanate (B) (1), wherein the aliphatic or cycloaliphatic diisocyanates.

(3) wherein (1) a carboxyl group-containing compound (A) is characterized in that it is a monocarboxylic acid.

Conventionally, allophanate-modified polyisocyanate compositions that can be produced relatively easily, have little coloration, and have low viscosity have been widely used in applications such as paints and adhesives.
The present invention is a method for producing an acylurea-modified polyisocyanate composition having excellent performance equivalent to that of an allophanate-modified polyisocyanate composition.
Acyl urea-modified polyisocyanate composition obtained by the present invention is a paint, adhesive, various binders, printing ink, magnetic recording medium, coating agent, sealing agent, elastomer, sealant, synthetic leather, various foams, civil engineering It can be applied to a wide range of foam fillers.

The raw material used for this invention is demonstrated.
A monocarboxylic acid is mentioned as a carboxyl group-containing compound (A) used for this invention.
An open chain or cyclic monocarboxylic acid is preferable, and acetic acid, 2-ethylhexanoic acid, hexanoic acid, and octanoic acid are more preferable.

  Examples of the organic diisocyanate (B) used in the present invention include 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-1,4-diisocyanate, naphthylene-1,5-diisocyanate, 3,3 ' Aromatic diisocyanates such as dimethoxydiphenyl-4,4'-diisocyanate; hexamethylene diisocyanate, tetramethylene diisocyanate, 2-methyl-pentane-1,5-diisocyanate, 3-methyl-pentane-1,5-diisocyanate, lysine diisocyanate, Aliphatic diisocyanates such as trioxyethylene diisocyanate; aromatic aliphatic diisocyanates such as xylylene-1,4-diisocyanate, xylylene-1,3-diisocyanate, tetramethylxylylene diisocyanate; isophorone diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated xylene Alicyclic dii such as diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tetramethylxylene diisocyanate Cyanate, and the like. These organic diisocyanates may be used alone or in the form of a mixture of two or more. In the present invention, considering the weather resistance of the acylurea-modified polyisocyanate obtained, non-yellowing diisocyanate selected from aliphatic, araliphatic and alicyclic is preferable, and hexamethylene diisocyanate is particularly optimal.

Acylurea catalyst used in the present invention (C) is a octylate zirconium beam.

In the present invention, it is preferable to stop the acylureaation reaction by adding a catalyst poison (D) (hereinafter referred to as a terminator). The acylurealation reaction is completed when the organic compound containing the amide group is exhausted, but the addition of a terminator stabilizes the production conditions and can improve the stability of the product.
As the terminator, acidic compounds such as phosphoric acid acidic compounds, sulfuric acid, nitric acid, chloroacetic acid, benzoyl chloride, sulfonic acid ester agents, ion exchange resins, chelating agents, chelating resins and the like can be used. Among these, a phosphoric acid acidic compound is preferable because it is less likely to corrode the base material of a reactor such as stainless steel, and a stopper residue can be easily removed.
Here, examples of the phosphoric acid acidic compound include phosphoric acid, pyrophosphoric acid, metaphosphoric acid, polyphosphoric acid, and alkyl esters thereof. In the present invention, at least one of these phosphoric acid acidic compounds is used as a terminator. Is preferred.
In addition, when a terminator containing no water is used, the reaction product of the terminator and the catalyst is likely to precipitate, so that the reaction product of the terminator and the catalyst hardly remains in the polyisocyanate composition. There is an effect of becoming. Furthermore, when a stop agent that does not contain water is used, the reaction product of water and isocyanate is not mixed in the polyisocyanate, so that there is no increase in viscosity of the polyisocyanate and there is an effect that the dilutability with respect to the organic solvent is not lowered. . In the present invention, “substantially not containing water” means that water may be contained as long as the above effects are exhibited. It is less than 0% by mass, preferably less than 2.0% by mass, more preferably less than 0.50% by mass.
Therefore, in the present invention, the phosphoric acid acidic compound used as a terminator is at least one compound selected from the group consisting of phosphoric acid, pyrophosphoric acid, metaphosphoric acid, and polyphosphoric acid that does not substantially contain water. It is particularly preferred that
It should be noted that phosphoric acid and metaphosphoric acid that do not contain water are crystals, and pyrophosphoric acid and polyphosphoric acid are viscous liquids that are difficult to use as they are, so they are usually used after being dissolved in a solvent. Examples of solvents that substantially dissolve water-free phosphoric acid, pyrophosphoric acid, and metaphosphoric acid include ketones, ethers, and esters. Particularly preferred examples include methanol, ethanol, n-propanol, Alcohols such as isopropanol, n-butanol, isobutanol, amyl alcohol, 1-hexanol and 2-ethyl-1-hexanol.

Next, a specific manufacturing procedure will be described.
In the method of the present invention, first, the organic diisocyanate (B) is reacted with the carboxyl group-containing compound (A).
The organic diisocyanate component is generally present in excess. The ratio of the organic diisocyanate and the carboxyl group-containing compound is preferably 950/50 to 550/450.
When the amount of the carboxyl group-containing compound is less than 50, the yield of the acylurea-modified polyisocyanate composition is deteriorated, and when the amount of the carboxyl group-containing compound is more than 450, the acid content increases and the acylurea-modified polyisocyanate composition cannot be produced. .
A solvent can also be introduced to increase the solubility of the carboxyl group-containing compound.
The reaction between the isocyanate and the carboxyl group-containing compound is accompanied by generation of carbon dioxide, and an amide is generated.
This amide and organic diisocyanate (B) react to produce an N-acyl urea body.

The carboxyl group-containing compound may be introduced after being dissolved in a suitable solvent.
n-hexane, octane and other aliphatic hydrocarbon organic solvents, cyclohexane, methylcyclohexane and other alicyclic hydrocarbon organic solvents, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone and other ketone organic solvents, methyl acetate, acetic acid Ester organic solvents such as ethyl, butyl acetate, isobutyl acetate, glycol ether esters such as ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, 3-methyl-3-methoxybutyl acetate, ethyl-3-ethoxypropionate Organic solvents, ether organic solvents such as diethyl ether, tetrahydrofuran, dioxane, halo such as methyl chloride, methylene chloride, chloroform, carbon tetrachloride, methyl bromide, methylene iodide, dichloroethane Emissions aliphatic hydrocarbon-based organic solvents, N- methylpyrrolidone, dimethylformamide, dimethylacetamide, dimethyl sulfoxide, polar aprotic solvents such as hexamethylphosphoric phosphonyl amides. The said solvent can be used 1 type, or 2 or more types.
The amount of solvent used is adjusted according to the solubility of the carboxyl group-containing compound. In a preferred embodiment of the method of the present invention, the carboxyl group-containing compound is dissolved in a solvent to form a 10-80 wt% solution, preferably a 20-40 wt% solution.
The carboxyl group-containing compound can be added to the reaction solution at room temperature or at a high temperature up to 150 ° C. The temperature range is preferably 0 ° C to 100 ° C, more preferably 20 ° C to 70 ° C.

  After carrying out the reaction, the solvent can be removed from the reaction batch by heating or by applying an additional vacuum, depending on the solvent used.

  In the practice of the process of the present invention, after the addition of the carboxyl group-containing compound to the organic diisocyanate or vice versa, the reaction mixture is stirred in the presence of the catalyst until gas evolution ceases. The reaction mixture is then heated to a higher temperature. The choice of reaction temperature is generally not limited, but yellowing of the organic diisocyanate is observed at excessively high temperatures. A suitable temperature is 20 ° C to 220 ° C, preferably 80 ° C to 150 ° C, more preferably 100 ° C to 140 ° C. Unlike known reactions that do not take place in the presence of a catalyst, in the catalytic reaction, the discoloration of the reaction mixture is significantly less even at higher temperatures.

  The amount of the acylureaization catalyst (C) used varies depending on the type thereof, but is preferably 0.0005 to 1% by mass, preferably 0.001 to 0.1% by mass, based on the total amount of the above (A) and (B). Is more preferable. When the amount of the catalyst used is less than 0.0005% by mass, the reaction is substantially delayed, requiring a long time, and coloring due to thermal history may occur. On the other hand, when the amount of the catalyst used exceeds 1% by mass, it is difficult to control the reaction, and a dimerization reaction (uretodione reaction) or a trimerization reaction (isocyanurate reaction), which are side reactions, may occur. When polyisocyanate is used as a curing agent for a two-component paint, problems such as a shortened pot life of the paint may occur.

  After the acyl urea reaction, the catalyst poison (D) is added to stop the acyl urea reaction. There is no particular limitation on the timing of addition of the catalyst poison (D) as long as it is after the acylureaization reaction. It is preferable to add a catalyst poison (D). This is to prevent side reactions from occurring due to heat during thin film distillation.

  As the catalyst poison (D), known substances such as inorganic acids such as phosphoric acid and hydrochloric acid, organic acids having a sulfonic acid group, a sulfamic acid group and the like, esters thereof, and acyl halides can be used.

  The amount of the catalyst poison (D) added varies depending on the type and type of the catalyst, but is preferably 0.5 to 2 equivalents, particularly preferably 0.8 to 1.5 equivalents of the catalyst. When there is too little catalyst poison, the storage stability of the polyisocyanate obtained tends to fall. When there are too many, the obtained polyisocyanate may color.

  The amount of by-products produced by the method of the present invention depends in particular on the amount and type of solvent used to dissolve the carboxyl group-containing compound.

  The reaction time varies depending on the type of catalyst, the amount added, and the reaction temperature, but is usually within 10 hours, preferably 1 to 5 hours.

  In the present invention, free isocyanate is basically present in the product after the acylureaization reaction. Since this free isocyanate causes odor and turbidity with time, it is preferable to remove the unreacted isocyanate until the free isocyanate content is 1% by mass or less.

  Examples of the method for removing free isocyanate include known methods such as distillation, reprecipitation, and extraction. Distillation, particularly thin film distillation, can be performed without using a solvent or the like, which is preferable. Further, preferable conditions for thin film distillation are pressure: 0.1 kPa or less, temperature: 100 to 200 ° C., and particularly preferable conditions are pressure: 0.05 kPa or less and temperature: 120 to 180 ° C.

  A preferred viscosity (25 ° C., solid content = 100% conversion) of the acylurea-modified polyisocyanate composition obtained by the present invention is 1000 mPa · s or less, and particularly preferably 500 mPa · s or less. Moreover, 10-20 mass% is preferable, and, as for isocyanate content (solid content = 100% conversion), Most preferably, it is 12-18 mass%.

  The acylurea-modified polyisocyanate composition obtained by the present invention may be added to an antioxidant such as 2,6-di-tert-butyl-4-methylphenol, an ultraviolet absorber, a pigment, a dye, a solvent, if necessary. In addition, additives such as flame retardants, hydrolysis inhibitors, lubricants, plasticizers, fillers, storage stabilizers and the like can be appropriately blended.

  The present invention will be described in more detail with reference to examples and comparative examples, but the present invention is not limited thereto. In Examples and Comparative Examples, “%” means “% by mass”.

Example 1
348 g of hexamethylene diisocyanate and 320 mg of zirconium octylate were placed in a 1 L 3-neck flask. 52 g of octanoic acid was added to the mixture. At the end of the addition, the temperature was adjusted to 130 ° C. and heating was continued for 6 hours.
Next, 350 mg of 2-ethylhexyl phosphate ester (manufactured by Johoku Chemical Industry Co., Ltd., trade name “JP-508”) was added to stop the reaction, and the mixture was cooled. The reaction solution whose NCO content was 36.0% was subjected to thin film distillation (temperature 130 ° C., pressure 1.5 × 10 −2 bar). 147 g (yield 36.7%, based on acid and isocyanate) of product having a color value of 30 [APHA] and a viscosity of 440 mPas / 25 ° C. were obtained. The amount of hexamethylene diisocyanate monomer was about 0.1%.

Example 2
360 g of hexamethylene diisocyanate and 240 mg of zirconium octylate were placed in a 1 L 3-neck flask. The temperature was kept at 70 ° C. and 40 g of hexanoic acid was added to the mixture. At the end of the addition, the temperature was adjusted to 130 ° C. and heating was continued for 4 hours.
Next, 260 mg of 2-ethylhexyl phosphate (Johoku Chemical Co., Ltd., trade name “JP-508”) was added to stop the reaction, and the mixture was cooled. The NCO content of the solution was 38.1%.
The reaction solution was subjected to thin film distillation (temperature 130 ° C., pressure 1.5 × 10 −2 bar). 131 g (yield 32.8%, based on acid and isocyanate) of product having a color value of 30 [APHA] and a viscosity of 730 mPas / 25 ° C. were obtained. The amount of hexamethylene diisocyanate monomer was about 0.1%.

Comparative Example 1
348 g of hexamethylene diisocyanate and 120 mg of zinc benzoate were placed in a 1 L 3-neck flask. The temperature was kept at 70 ° C. and 52 g of octanoic acid was added to the mixture. At the end of the addition, the temperature was adjusted to 130 ° C. and heating was continued for 5 hours.
Next, 180 mg of 2-ethylhexyl phosphate (manufactured by Johoku Chemical Co., Ltd., trade name “JP-508”) was added to stop the reaction, and the mixture was cooled. The NCO content of the solution was 35.3%.
The reaction solution was subjected to thin film distillation (temperature 130 ° C., pressure 1.5 × 10 −2 bar). 147 g (yield 36.7%, based on acid and isocyanate) of product having a color value of 30 [APHA] and a viscosity of 1220 mPas / 25 ° C. were obtained. The amount of hexamethylene diisocyanate monomer was about 0.1%.

Comparative Example 2
380 g of hexamethylene diisocyanate was placed in a 1 L 3-neck flask. Then 20 g of acetic acid was added over 15 minutes. The temperature during the addition was 70 ° C.
At the end of the addition, the temperature was adjusted to 110 ° C. and heating was continued for 27 hours.
The mixture was then cooled.
The reaction solution whose NCO content was 42.1% was subjected to thin-film distillation (temperature 130 ° C., pressure 1.5 × 10 −2 bar). 109 g (yield 27.3%, based on acid and isocyanate) of product having a color value of 500 [APHA] and a viscosity of 569 mPas / 25 ° C. were obtained. The amount of hexamethylene diisocyanate monomer was about 0.1%.

ＨＤＩ：ヘキサメチレンジイソシアネート（日本ポリウレタン工業株式会社製）
ＪＰ−５０８：リン酸２−エチルヘキシルエステル（城北化学工業株式会社製）
ＴＰＰ：トリフェニルフォスファイト（城北化学工業株式会社製）

HDI: Hexamethylene diisocyanate (Nippon Polyurethane Industry Co., Ltd.)
JP-508: 2-ethylhexyl phosphate (manufactured by Johoku Chemical Industry Co., Ltd.)
TPP: Triphenyl phosphite (Johoku Chemical Industry Co., Ltd.)

As can be seen from Table 1, when zinc benzoate is used as the acylureaization catalyst instead of zirconium octylate, the viscosity increases to about twice that of the examples, making handling difficult.
Moreover, when it is made to react without using a metal salt catalyst, reaction time will require 27 hours with respect to 5-6 hours when a metal salt catalyst was put.

Claims (3)

A process for producing an acylurea-modified polyisocyanate composition from a carboxyl group-containing compound (A), an organic diisocyanate (B) and an acylureaization catalyst (C), wherein the acylurealation catalyst (C) is zirconium octylate, A method for producing an acylurea-modified polyisocyanate composition, characterized in that a catalyst poison (D) is used to stop the conversion reaction . The organic diisocyanate (B) is an aliphatic or granulation how Made in acylurea modified polyisocyanate composition according to claim 1, characterized in that a cycloaliphatic diisocyanate. Carboxyl group-containing compound (A), forming how Made in acylurea modified polyisocyanate composition according to claim 1, characterized in that the monocarboxylic acid.