JP2001261660A - Method for producing isocyanulate ring-containing polyisocyanate having less coloration - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing an isocyanate ring-containing polyisocyanate having less coloration obtained by subjecting 2,5(6)- diisocyanatemethyl[2.2.1]heptane under an isocyanulate-forming reaction. SOLUTION: This method for producing the isocyanulate ring-containing polyisocyanate having less coloration is provided by subjecting 2,5(6)- diisocyanatemethyl[2.2.1]heptane obtained by reacting 2,5(6)- diaminomethyl[2.2.1]heptane having <=0.02 wt.% phenol content with phosgene, under the isocyanulate-forming reaction in the presence of a catalyst.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polyisocyanate having an isocyanurate ring, which is useful as a curing agent when producing a polyurethane resin such as a polyurethane paint or a casting material.

[0002]

2. Description of the Related Art Isocyanurate ring-containing polyisocyanates obtained by converting isocyanates into isocyanurates are used in various applications such as foams, elastomers, paints and adhesives. A number of patents have been filed for the production of polyisocyanates containing isocyanurate rings.

[0003] Among them, Japanese Patent Publication No. 7-5573,
(1) a polyethylene oxide compound, (2) a quaternary ammonium salt, together with potassium fluoride or potassium fluoride described in JP-B-7-5574.
(3) The method of using one or a combination of two or more selected from phosphonium compounds as a catalyst is introduced as a method for obtaining a nearly colorless and transparent isocyanurate ring-containing polyisocyanate.

Further, in Japanese Patent Application Laid-Open No. H11-1478, one or two selected from (1) polyethylene oxide compounds, (2) quaternary ammonium salts, and (3) phosphonium compounds are used together with potassium fluoride as a catalyst. A method for isocyanuration using a combination of two or more species and further using a dialkyltin compound as a cocatalyst is described. This method is a production method characterized by the fact that the reaction proceeds even at a low isocyanurate-forming temperature, the amount of catalyst used is small, and the resulting isocyanurate ring-containing polyisocyanate has a good hue.

[0005]

However, the isocyanuration reaction of 2,5 (6) -diisocyanatomethyl [2,2,1] heptane (hereinafter abbreviated as NBDI) is carried out by the above production method. Then, the resulting isocyanurate ring-containing polyisocyanate often has a problem of coloring.

The problem to be solved by the present invention is that the NBD
An object of the present invention is to find a production method in which isocyanurate ring-containing polyisocyanate (hereinafter abbreviated as NBDI nullate) obtained by subjecting I to an isocyanurate-forming reaction is less colored.

[0007]

The present inventors have conducted intensive studies in view of these points, and as a result, have found that 2,5 (6) -diaminomethyl [2] having a phenol content of 0.02% by weight or less. , 2,1] heptane (NBDA)
It has been found that a polyisocyanate containing an isocyanurate ring with little coloring can be obtained by subjecting NBDI obtained by phosgenation reaction to an isocyanurate reaction, thereby completing the present invention.

That is, the present invention is as follows. 2,5 having a phenol content of 0.02% by weight or less
(6) -Diaminomethyl [2.2.1] heptane isocyanurated in the presence of a catalyst using 2,5 (6) -diisocyanatomethyl [2.2.1] heptane obtained by phosgenation reaction A process for producing an isocyanurate ring-containing polyisocyanate having less coloring, characterized by comprising: (1) a polyethylene oxide compound, (2) a quaternary ammonium salt together with potassium fluoride as a catalyst,
(3) The production method according to the above, wherein one or a combination of two or more compounds selected from phosphonium compounds is used, and a dialkyltin compound is used as a co-catalyst. The production method according to the above, wherein the dialkyltin compound is di-n-butyltin dilaurate.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS NB used in the present invention
DI is NBDA with a phenol content of 0.02% by weight or less
Manufactured from

In the present invention, the phenol content in NBDA is measured by gas chromatography analysis.
Specifically, a G column (1.2 mm × 40 m) manufactured by Japan Chemical Inspection Association is used for the column, and GC-14B manufactured by Shimadzu Corporation is used for the gas chromatography device. The column temperature is raised to 290 ° C. at 3 ° C./min after holding at 120 ° C. for 5 minutes. The injection temperature is 250 ° C. and the detector temperature is 300 ° C., which is detected by FID. Gas pressure is nitrogen 80
kPa, hydrogen 60 kPa, and air 50 kPa. The range is 100 MΩ. 1 g of NBDA was dissolved in 9 ml of 1,4-dioxane, and 1 μl was injected. The peak detected at 4.0 minutes was phenol, and the peak detected at 16 minutes was NBDA.

According to gas chromatography analysis, if the phenol content in NBDA is less than 0.02% by weight,
NBDI is induced by the phosgenation reaction, but if the phenol content is 0.02% by weight or more, it is necessary to remove phenol.

Methods for removing phenol from NBDA include distillation, extraction of phenol with a basic aqueous solution, and the like. A preferred method of removing phenol is to charge phenol-containing NBDA with an aqueous sodium hydroxide solution and distill phenol from its sodium salt.

The amount of the sodium hydroxide solution to be charged is sufficient if 1.0 to 2.0 molar equivalents of sodium hydroxide to phenol are charged.

N having a phenol content of 0.02% by weight or less
NBDI is obtained by phosgenation reaction of BDA.

The method for producing NBDI from NBDA can be produced, for example, by the method described in JP-A-3-220167. Specifically, NBDA is reacted with hydrochloric acid to form NBDA hydrochloride, followed by reaction with phosgene to produce NBDI.

The NBDI nitrate obtained by the NBDI isocyanuration reaction in the present invention is NBDI
By isocyanuration reaction in the presence of a catalyst.

The isocyanuration of NBDI in the present invention is preferably carried out by using potassium fluoride as a catalyst together with potassium fluoride as one of compounds selected from (1) polyethylene oxide compounds, (2) quaternary ammonium salts, and (3) phosphonium compounds. A species or a combination of two or more species is used, and a dialkyltin compound is used as a promoter.

Potassium fluoride used as a catalyst in the isocyanuration reaction can be used in various forms such as pellets, powders, and flakes. Potassium is particularly preferred.

Used together with potassium fluoride (1)
Examples of the polyethylene oxide compound include polyethylene glycols such as polyethylene glycol, polyethylene glycol monomethyl ether and polyethylene glycol dimethyl ether, and dibenzo-18-crown-
6, dicyclohexyl-18-crown-ethers such as crown-6, for example C is commercially available as Kanto Chemical Co. [Kryptofix -111] ₁₄ H ₂₈ N ₂ O
_And cryptands such as ₄ . Among them, polyethylene glycol is preferable, and among them, polyethylene glycol having an average molecular weight of 400 (PEG40
0) is preferable because of its high activity.

Used together with potassium fluoride (2)
Examples of the quaternary ammonium salt include benzyltrimethylammonium chloride, tetrabutylammonium bromide and the like.

Used with potassium fluoride (3)
Examples of the phosphonium compound include trioctylphosphonium bromide, tetrabutylphosphonium chloride and the like.

The amount of potassium fluoride used is 0.0001 to 0.05% by weight based on the isocyanate used in the reaction.
Is sufficient, preferably 0.0005 to 0.02.
% By weight. The amount of the compounds (1) to (3) to be used is preferably 1/100 to 100 times the amount of potassium fluoride.

Examples of the dialkyltin compound used as a cocatalyst in the present invention include dialkyltin dicarboxylates such as dimethyltin diacetate, dibutyltin dioctanoate, dibutyltin dilaurate, dibutyltin dibutoxide, and dioctyltin. Dialkyltin dialkoxides such as dibutoxide, dialkyltin dithioalkoxides such as dibutyltin di (thiobutoxide), dialkyltin oxides such as di (2-ethylhexyl) tin oxide, dioctyltin oxide and bis (butoxydibutyltin) oxide And dialkyltin sulfides such as dibutyltin sulfide. Among them, dialkyltin dicarboxylates are preferred, and di-n-butyltin dilaurate is more preferred.

In the present invention, dialkyltin halides such as dibutyltin dichloride and dimethyltin dichloride have almost no effect as a cocatalyst.

The amount of cocatalyst used is preferably 1/10 to 10 times the amount of potassium fluoride used, and
In the following, the effect as a co-catalyst is small, and if it is more than 10 times, the product isocyanurate ring-containing polyisocyanate may be cloudy, which may adversely affect physical properties, which is not preferable.

In the present invention, active hydrogen compounds such as alcohols and compounds generally known as co-catalysts for isocyanuration such as tertiary amines and phosphite triesters may be used in combination.

The catalyst and the cocatalyst may be added to the raw material isocyanate, respectively, or may be added in advance after mixing.

The reaction temperature for isocyanuration is from 10 to 8
0 ° C, preferably 20 to 60 ° C.

In the present invention, a solvent may or may not be used at the time of the isocyanuration reaction.

When a solvent is used in the isocyanurate-forming reaction in the present invention, an isocyanato group non-reactive solvent is preferred. Examples of the isocyanato group non-reactive solvent include ethyl acetate, butyl acetate, toluene, xylene, tetrahydrofuran, 1,4-dioxane, n-hexane, o-
Examples include, but are not limited to, dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, and the like. The water in the solvent reacts with the isocyanate and produces undesirable urea, which must be removed.

The reaction is stopped when the desired conversion has been reached. As a method for stopping the reaction, it is preferable to add an acidic substance. It is preferable to use an acidic phosphate ester containing an alkoxy group or an alkylene oxide group described in JP-A-11-12342 since no cloudiness occurs.

The conversion of the reaction can be determined by the isocyanato titration of the reaction solution by the di-n-butylamine method, gas chromatography, refractive index, viscosity, infrared spectrometry and the like.

In the method for evaluating the hue of NBDI nullate, the reaction solution after the termination of the reaction is visually evaluated. Specifically, the reaction solution was charged into an APHA measurement tube, compared with a standard solution, and compared with an APHA measurement tube.
Find the value. The reaction solution stopped at a reaction conversion rate of 30 to 50% is NBD with little coloring if APHA is 40 or less.
I Nurate.

[0034]

The present invention will be described below in more detail with reference to examples, but the method of the present invention is not limited to the examples.

Example 1 NBDA185 having a phenol content of 0.0197% by weight
g was dissolved in 1665 g of o-dichlorobenzene,
NBD by blowing 109.5 g of hydrochloric acid gas at ~ 140 ° C
A hydrochloride was used. After aging at 140 ° C. for 1 hour, 1158 g of phosgene gas was blown at 165 to 170 ° C. for 5 hours to carry out a phosgenation reaction. Nitrogen was blown into the reaction solution to remove phosgene gas and hydrochloric acid gas dissolved in the reaction solution. After ODCB was removed by distillation, distillation purification was carried out and 1
97 g of NBDI were obtained.

A four-necked flask equipped with a reflux condenser, a thermometer and a stirrer was charged with 130 g of NBDI and 0.01 g of dibutyltin dilaurate. The temperature inside the reactor was raised to 45 ° C. while stirring under a nitrogen atmosphere, and 0.026 g of potassium fluoride mixed in advance and 6.541 g of polyethylene glycol (PEG400) having an average molecular weight of 400 were added over 3 hours, and dibutoxyethyl was added. Phosphate 0.
The reaction was stopped by adding 44 g. As a result of analysis by gas chromatography, the reaction conversion was 38%. The color of the obtained isocyanurate ring-containing polyisocyanate is AP
HA30.

Example 2 NBDA183 having a phenol content of 0.0088% by weight
g was dissolved in 1660 g of amyl acetate,
Then, 110.9 g of hydrochloric acid gas was blown in to obtain NBDA hydrochloride. After aging at 140 ° C. for 1 hour, 1350 g of liquefied phosgene was charged at 135 ° C. over 10 hours to carry out a phosgenation reaction. Nitrogen was blown into the reaction solution to remove phosgene gas and hydrochloric acid gas dissolved in the reaction solution. After removing amyl acetate by distillation, the residue was purified by distillation to obtain 170 g of NB.
DI was obtained.

A four-necked flask equipped with a reflux condenser, a thermometer and a stirrer was charged with 100 g of NBDI and 0.01 g of dibutyltin dilaurate. The temperature inside the reactor was raised to 45 ° C. while stirring under a nitrogen atmosphere, and 0.005 g of potassium fluoride mixed in advance and 1.22 g of polyethylene glycol (PEG400) having an average molecular weight of 400 were added to 2 parts.
The reaction was added over a period of 50 minutes, and the reaction was stopped by adding 0.20 g of dibutoxyethyl phosphate. As a result of analysis by gas chromatography, the reaction conversion was 44%. The color of the obtained isocyanurate ring-containing polyisocyanate was APHA30.

Comparative Example NBDA 186 having a phenol content of 0.2287% by weight
g was dissolved in 1674 g of amyl acetate.
Then, 110.4 g of hydrochloric acid gas was blown in to obtain NBDA hydrochloride. After aging at 140 ° C. for 1 hour, 1334 g of liquefied phosgene was charged at 135 ° C. over 10 hours to carry out a phosgenation reaction. Nitrogen was blown in to remove phosgene gas and hydrochloric acid gas dissolved in the reaction solution. After removing amyl acetate by distillation, the residue was purified by distillation to obtain 171 g of NB.
DI was obtained.

A four-necked flask equipped with a reflux condenser, a thermometer and a stirrer was charged with 100 g of NBDI and 0.01 g of dibutyltin dilaurate. The temperature inside the reactor was raised to 45 ° C. while stirring under a nitrogen atmosphere, and 0.004 g of potassium fluoride mixed in advance and 1.09 g of polyethylene glycol (PEG400) having an average molecular weight of 400 were added to the reactor.
The reaction was added over a period of 30 minutes, and the reaction was stopped by adding 0.15 g of dibutoxyethyl phosphate. As a result of analysis by gas chromatography, the conversion of the reaction was 45%, and the color of the obtained isocyanurate ring-containing polyisocyanate was APH.
A60.

[0041]

According to the method of the present invention, NBDI obtained by phosgenating NBDA having a phenol content of 0.02% by weight or less is used, and an isocyanurate-forming reaction is carried out to produce NBDI nullate with less coloring. Can be.

Continued on the front page (72) Inventor Hideki Mizuta 30 Asamuta-cho, Omuta-shi, Fukuoka Prefecture Mitsui Chemicals, Inc. (72) Inventor Naoto Ito 30-30 Asamuta-cho, Omuta-shi, Fukuoka Mitsui Chemicals, Inc. (72) Invention Person Masahiko Kusumoto 30 Asamata-cho, Omuta-shi, Fukuoka Mitsui Chemicals, Inc. F term (reference) 4H039 CA42 CH30 4J034 HA06 HA08 HB05 HC06 HC35

Claims (3)

[Claims] 1. A 2,5 (6) -diphenol obtained by subjecting 2,5 (6) -diaminomethyl [2.2.1] heptane having a phenol content of not more than 0.02% by weight to a phosgenation reaction. A process for producing a less colored isocyanurate ring-containing polyisocyanate, which comprises subjecting isocyanatomethyl [2.2.1] heptane to an isocyanurate reaction in the presence of a catalyst. (2) A catalyst together with potassium fluoride (1)
One or a combination of two or more compounds selected from polyethylene oxide compounds, (2) quaternary ammonium salts, and (3) phosphonium compounds are used, and a dialkyltin compound is used as a co-catalyst. The manufacturing method according to claim 1, wherein 3. The method according to claim 1, wherein the dialkyltin compound is di-n-butyltin dilaurate.