JPH01229026A - Aromatic polyisocyanate and its production - Google Patents

Abstract

PURPOSE:To obtain the title novel isocyanate which is useful as a starting substance for polyurethane resins or polyurea resins which is used in foams, elastomer, synthetic leather or adhesive, by reaction of phosgen with a specific aromatic resin or its salt. CONSTITUTION:The reaction of phosgen with an aromatic amine resin of formula I (A is phenylene, alkylene, alkyl-substituted phenylene, diphenylene, diphenyl ether, naphthynyl; R1 is H, halogen, 1-4C alkoxy, 1-5C alkyl; 1 is 1, 2; m is 0-3; n is 0-300) or its salt gives the subject polyisocyanate of formula II.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to an aromatic polyisocyanate and a method for producing the same. As a raw material, it can be used in a variety of ways, including foams, elastic bodies, synthetic leather, adhesives, and films.

(Prior Art) A well-known aromatic polyisocyanate is polyphenylmethane polyisocyanate (P-MDI) represented by the general formula (e), which is widely used as a raw material for polyurethane resins and polyurea resins. It is used in the direction.

(Problems to be Solved by the Invention) The present invention is directed to a novel aromatic polyisocyanate which is expected to find new uses as a raw material for polyurethane resins, polyurea resins, etc. The challenge is to provide.

(Means and effects for solving the problem) As a result of intensive studies to achieve the above-mentioned problems, the present inventors have found that the present invention can be achieved by using an aromatic amine resin having a specific structure or a salt thereof. finding that the task can be accomplished,
The present invention has now been completed.

That is, the present invention is based on the general formula (a) (wherein A represents a phenylene group, an alkylene group, an alkyl-substituted phenylene group, a diphenylene group, a diphenyl ether group, or a naphthylenyl group, and R3 is a hydrogen atom, a halogen atom, or has a carbon number of 4 The following lower alkoxy group or carbon number 5
represents the following lower alkyl group, R2 may be the same or different from each other, and may form a ring; l is l
or 2, 1 represents an integer from 0 to 3, and 7 represents an integer from 0 to 30.
It is an aromatic polyisocyanate represented by the general formula (b) (in which ^, R1, 1, 11, and R are the same as those described in claim 1). (b) A method for producing an aromatic polyisocyanate represented by the general formula (a), which comprises reacting an aromatic amine resin represented by the following or a salt thereof with phosgene.

The aromatic amine resin represented by the general formula (b) is a completely new compound that was recently developed, and its properties and manufacturing method are disclosed in Japanese Patent Application No. 62-252517 and Japanese Patent Application No. 6
2-282048.

The method for producing the aromatic polyisocyanate represented by the general formula (a) of the present invention will be described.

The aromatic polyisocyanate of the present invention is
) A method of directly reacting an aromatic amine resin represented by formula (b) with phosgene, or a method of synthesizing a salt such as a hydrochloride of an aromatic amine resin represented by -tC formula (b) in advance and reacting it in an inert solvent. It is produced by a method of allowing Qi to react with phosgene.

The former method is called "cold-thermal two-stage phosgenation," and there are no particular limitations on the implementation of the reaction. In the presence of a solvent, the inside of the reaction system is cooled to 0 to 5°C, phosgene gas is introduced, and phosgene is used as an inert solvent! The above aromatic amine resin was dissolved and then dissolved in an inert solvent while introducing a predetermined amount of phosgene gas. Add 8 liquids. During this time, the temperature of the reaction solution is kept below 15°C, and the generated hydrogen chloride and excess phosgene are released through a reflux condenser.The contents of the reactor become slurry. The main reactions are the production of carbamyl chloride and amine hydrochloride. After addition of the amine solution, the reaction is continued for a predetermined period of time.

The above process is called cold phosgenation.

Next, the reaction system was heated to 140°C in about 1 hour. Since dissolved phosgene tends to vaporize and foam when the temperature is raised, the phosgene flow rate is reduced to a predetermined amount compared to when cold phosgenation is performed. After raising the temperature, the reaction is continued for a predetermined period of time. If the slurry is completely dissolved, the reaction is complete, and a reaction of 0 or more is called thermal phosgenation. The main reactions of thermal phosgenation are decomposition of carbamyl chloride to isocyanate and phosgenation of amine hydrochloride to isocyanate.

After the completion of thermal phosgenation, the inside of the reaction system is heated to 160'C and a predetermined amount of nitrogen gas is blown into the reaction system to remove dissolved gas and sufficiently decompose unreacted carbamyl chloride.

After cooling, the inert solvent is distilled off under reduced pressure to obtain aromatic polyisocyanate.

The latter method is called "amine hydrochloride phosgenation method," and the hydrochloride of the aromatic amine resin is synthesized in advance. The hydrochloride is easily synthesized by a well-known method by treating an aromatic amine resin with hydrogen chloride or concentrated hydrochloric acid. The above aromatic amine hydrochloride, which has been thoroughly dried and pulverized, is dispersed in an inert solvent in a reactor similar to that used in the above-mentioned "cold-hot two-stage phosgenation method", and the reaction temperature is raised to 8.
The progress of the reaction, which is maintained at 0 to 150°C and synthesizes isocyanate by introducing phosgene gas, is due to the amount of hydrogen chloride gas generated and the disappearance of the aromatic amine hydrochloride that is insoluble in the inert solvent as a raw material. The generated hydrogen chloride and excess phosgene gas, which can be inferred by the fact that the reaction solution becomes transparent and homogeneous, are released through a reflux condenser.

After the reaction is completed, nitrogen gas is introduced into the reaction solvent to remove dissolved phosgene, and after cooling and filtration, the inert solvent is distilled off under reduced pressure to obtain aromatic polyisocyanate.

The amount of phosgene to be introduced is 3 to 1 times the theoretical amount of the “cold-heat two-stage phosgenation method” and the “amine hydrochloride phosgenation method”.
It is sufficient to use 0 times the amount. The inert solvent is an aromatic hydrocarbon or a chlorinated aromatic hydrocarbon, preferably orthodichlorobenzene.

(Example) Hereinafter, the present invention will be specifically explained with reference to Examples.

Examples will be particularly described for polyparaxylylene polyphenyl polyisocyanate (C) in which A is a p-phenylene group, R3 is a hydrogen atom, and l in the general formula (a). ) is not limited to the examples.

(Example 1) Phosgenation was carried out using polyvaraxylylene polyalinine represented by formula (b) -C as a raw material (b). The molecular weight distribution of the polyaniline resin as a raw material was determined by high performance liquid chromatography using a GPC column. As a result of compositional analysis, n-0 of general formula (b)° is 76.3wtχ, n-1 is 18.7wt%, n
=2 is 4.3 wt%, n-=3 or more is Q, 7 wt%, the average molecular weight is about 350, and the amine equivalent of this resin by the perchloric acid-glacial acetic acid method was 0.653 eq/100 g. . After stirring, 682 g of orthodichlorobenzene was charged into a 21 reaction flask equipped with a thermometer, phosgene gas introduction tube, cooling tube, and dropping funnel, and while stirring, the reaction flask was placed in an ice water bath to bring the internal temperature to 1 to 2 °C. Then, 100 g of the above polyaniline resin dissolved in 704 g of orthodichlorobenzene was added dropwise over 45 minutes.
Phosgene gas was introduced at a rate of /h. At this time, the temperature was 2 to 8°C2.Cold phosgenation was carried out at 4 to 5"C while introducing phosgene gas at a rate of 100 g/hour for another 30 minutes. Due to the cold phosgenation, carbamyl chloride and amine were present in the reaction flask. The reaction flask, which had formed a yellow-green slurry due to the formation of hydrochloride, was then heated using a mantle heater, and the temperature was raised to 140'C in about 45 minutes.

During the temperature rise, phosgene gas was introduced at a rate of 100 g/hour. During the temperature rise, the slurry completely dissolved in ortho-dichlorobenzene while generating hydrogen chloride residue.

Furthermore, thermal phosgenation was carried out at 140"C while introducing phosgene gas at a rate of toog/hour. A total of 525 g of phosgene gas was introduced in the cold and hot two-stage phosgenation. This was 8.1 times the theoretical amount. Then, the reaction solution was heated to 160 ml.
After raising the temperature to °C, nitrogen gas was introduced at a rate of 500 a+f/min for 2 hours to remove dissolved gas and to sufficiently decompose unreacted carbamyl chloride.

After cooling, a small amount of insoluble matter was removed by filtration, and the mixture was heated under reduced pressure (approximately 1
119.
The analysis result of 8g obtained is NC0%23.5% (theoretical value 2
3.5%), hydrolyzable chlorine was 0.28 wt%, acid content was 0.063%, and residual 0DCB was 47 ppm.

The results of IR analysis of this aromatic polyisocyanate are shown in FIG.

Example 2 30 g of the aromatic polyisocyanate obtained in Example 1 was purified by vacuum distillation. Boiling point 210-220
'C/ 0.2 mmHg, Naru flask oil bath/! !
Approximately 20 g of a yellow transparent liquid was obtained at 220-240°C.

This liquid material quickly solidified into crystals with a melting point of 45-48°C. As a result of the analysis shown below, it was revealed that this liquid was paraxylylene diphenyl isocyanate in which n=0 in the aromatic polyisocyanate-s formula (C) obtained in Example 1.

・Elemental analysis (CzzLaNtO□) HN calculated value (χ)? 7.63 4.74 8.23
Analysis (+!(χ) 77.86 4.35 8.
25・NC0% Analysis value 24.65% (calculated value 24.6
9%)・IR Figure 2・HNMR (CDCl3.7M5) ppm63.92
(4H-CH,-x2)7.10 (12)I
Ph-H, According to the same compositional analysis as in Example 1, the molecular weight distribution of the raw material polyaniline resin was 56.5 wt%, n-
=1 is 26.5wt%, n=2 is 10.1-t%, n=
3 was 5.5 wt%, n==4 was 1.3 wt%, the average molecular weight was about 423, and the amine equivalent of this resin by the perchloric acid-glacial acetic acid method was 0.633 eq/100 g. 100 g of this polyaniline resin was dissolved in 704 g of orthodichlorobenzene, and phosgenation was performed in the same manner as in Example 1. A total of 400 g of phosgene gas was introduced in the cold and hot two-stage phosgenation. This amount was 6.4 times the theoretical amount.Next, dissolved gas was removed from the reaction solution, and carbamyl chloride was sufficiently decomposed. After cooling, filtration is performed, and then orthodichlorobenzene is distilled off under reduced pressure to obtain polyparaxylylene polyphenyl polyisocyaner) 103.
Upon analysis of the obtained 5 g, NC0% 23.1%,
The hydrolyzable chlorine content was 0.41 wt% and the acid content was 0.10%.

(Effects of the Invention) The aromatic polyisocyanate obtained by the method of the present invention is a completely new compound that has not been previously known, and is expected to find new uses as a raw material for polyurethane resins, polyurea resins, etc. In addition, by operations such as high vacuum distillation from this aromatic polyisoneanate, A in -S formula (a) can be obtained.
is a p-phenylene group, R1 is a hydrogen atom, 1. A relatively low-molecular aromatic polyisonanate (aromatic diisonanate) in which n is O is obtained, and this is also a completely new compound and is expected to have new uses.

[Brief explanation of the drawing]

FIG. 1 is an IR chart of polyparaxylylene polyphenyl polyisocyanate in Example 1, and FIG. 2 is an IR chart of paraxylylene diphenyl isocyanate in Example 2. Patent applicant: Mitsui Toatsu Chemical Co., Ltd. ΔNaoshige (η) Reference rate ('/e)

Claims (4)

[Claims] (1) General formula (a) ▲ Numerical formulas, chemical formulas, tables, etc. ▼ (a) (In the formula, A represents a phenylene group, an alkylene group, an alkyl-substituted phenylene group, a diphenylene group, a diphenyl ether group, or a naphthylenyl group, and R_1 represents a hydrogen atom, a halogen atom, a lower alkoxy group having 4 or less carbon atoms, or a lower alkyl group having 5 or less carbon atoms, and R_1 may be the same or different from each other, and may form a ring._
l represents 1 or 2, _m represents an integer from 0 to 3, _n
represents an integer from 0 to 300. ) aromatic polyisocyanate. (2) General formula (b) ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ (b) (In the formula, A, R_1, _l, _m, _n are the same as those described in claim 1) Fragrance represented by A method for producing an aromatic polyisocyanate represented by the general formula (a), which comprises reacting a group amine resin or a salt thereof with phosgene. (3) A is p-phenylene group, R_1 is hydrogen atom, _l
The aromatic polyisocyanate according to claim 1, wherein is 1. (4) The aromatic polyisocyanate according to claim 3, wherein n is 0.