KR930000374B1 - Process for producing aromatic polyisocyanate - Google Patents

Abstract

No content.

Description

Aromatic Polyisocyanate and Manufacturing Method Thereof

1 is an IR spectrum of the polyparaxylylene-polyphenyl-polyisocyanate obtained in Example 1. FIG.

2 is an IR spectrum of paraxylylene diphenylisocyanate obtained in Example 2. FIG.

The present invention relates to an aromatic polyisocyanate and a method for producing the same.

The polyisocyanate of the present invention is a polyisocyanate having a novel structure and is used as a raw material of polyurethane resins and polyurea resins in various fields such as foams, elastomers, synthetic leathers, adhesives and films.

Among the aromatic polyisocyanates conventionally known, the following general formula

Polyphenylmethane-polyisocyanate (hereinafter referred to as P-MDI) represented by is well known, and is widely used as a raw material for polyurethane resins and polyurea resins.

The first object of the present invention is to provide a novel aromatic polyisocyanate which is completely different from P-MDI and is expected to be used as a raw material for polyurethane resins and polyurea resins.

A second object of the present invention is to provide a novel process for preparing the polyisocyanate.

In order to achieve the above object, extensive research by the present inventors has found that the object of the present invention can be achieved by reacting an aromatic amine resin having a specific structure or a salt thereof with phosgene, and the present invention is based on this finding. Is achieved.

In particular, the novel polyisocyanates of the present invention are of the general formula,

은 1 또는 2, m은 0~3의 정수이고 n은 0~300의 정수를 나타낸다)로 표현되는 방향족 폴리이소시아네이트의 혼합물을 포함하는 폴리이소시아네이트이다.(Wherein A represents a phenylene group, an alkylene group, an alkyl-substituted phenylene group, a diphenylene group, a diphenylether group or a naphthyleneyl group, and R ₁ is a halogen atom, a lower alkoxy group having 4 or less carbon atoms or a lower alkyl group having 5 or less carbon atoms) R ₁ may be the same or different from each other and may form a ring

Is 1 or 2, m is an integer of 0-3, n represents an integer of 0-300), and is a polyisocyanate containing the mixture of aromatic polyisocyanate represented by).

Further, the novel production method of the present invention is a method for producing a polyisocyanate comprising a mixture of aromatic polyisocyanates represented by the general formula (a), which method is a general formula

Reacting an amine with an amine, or an aromatic amine resin comprising a mixture of aromatic amine compounds represented by formula (A, R ₁ , 1, m, and n are the same as in general formula (a)).

The aromatic amine resin represented by formula (b) is a novel compound recently developed and its properties and preparation methods are described in detail in Japanese Patent Application Nos. 252517/1987 and 282048/1987.

The aromatic polyisocyanate of the present invention is prepared by directly reacting the aromatic amine resin represented by the general formula (b) with phosgene or by synthesizing a salt such as a hydrochloride salt of the aromatic amine resin in advance and suspending the salt in an inert solvent. Prepared by reaction with phosgene.

The former method is called ″ cold heat two-stage phosgenation ″ and the embodiment of the reaction is not particularly limited, but in general, the reaction system may be completely stirred, and the temperature of the reaction system in a reactor equipped with a phosgene gas introduction tube is 0-5. The phosgene gas is introduced into the inert solvent while cooling to 캜. That is, the phosgene is dissolved in an inert solvent so that the solubility of the phosgene in the solvent is almost saturated, and then the amine resin described above is dissolved in the inert solvent, and a solution formed separately is introduced into the stoichiometric amount of phosgene 1-2 times. Add. About halfway, the temperature of the reaction solution is maintained at 15 ° C., and hydrogen chloride and excess phosgene generated are released to the outside of the system through a reflux condenser. The contents in the reactor form a slurry and the main reaction is the production of carbamyl chloride and amine hydrochloride. After adding the amine solution, the reaction proceeds for 30 minutes to 2 hours. The method described above is called cold phosgenation.

Next, the reaction system is heated at a temperature of 130 ° C to 160 ° C for 30 minutes to 3 hours. Increasing the temperature is preferable to reduce the flow ratio of phosgene to the theoretical amount as opposed to the case of cold phosgenation, since phosgene dissolved in the solvent tends to vaporize to foam. After raising the temperature, the reaction proceeds for 1 to 3 hours. When the slurry is completely dissolved, the reaction is considered complete. This method is called thermophosphogenation and the main reactions of thermophosphogenation are the decomposition of carbamyl chloride to isocyanate and phosgenation of amine hydrochloride to isocyanate.

After the completion of thermal phosgenation, the reaction system is heated to a temperature of 150 to 180 ° C., and nitrogen gas is blown into the reaction system at an appropriate ratio (ie, 200 ml / min; this value varies depending on the reaction scale) to dissolve the dissolved gas component. Remove and sufficiently decompose the unreacted carbamylchloride. Next, after cooling, the inert solvent is distilled off under reduced pressure to obtain an aromatic polyisocyanate.

The latter method is called "phosgenation of amine hydrochloride", and the hydrochloride of the aromatic amine resin described above is synthesized in advance. The synthesis of the hydrochloride is easily carried out by known methods in which the aromatic amine resin is treated with hydrogen chloride or concentrated hydrochloric acid. The sufficiently dried and pulverized aromatic amine hydrochloride thus formed is dispersed in an inert solvent in the same reactor as used in the ″ cold heat two stage phosgenation ″ process described above and the reaction system is maintained at a temperature of 80-160 ° C. and the phosgene in the system Gas is introduced for 3 to 10 hours to make the total phosgene introduction amount 2 to 10 times stoichiometrically to synthesize isocyanate. The progress of the reaction can be estimated by the amount of generated hydrogen chloride gas, the loss of aromatic amine hydrochloride used as a raw material, and insoluble in an inert solvent, and the transparency and uniformity of the reaction solution. The generated hydrogen chloride and excess phosgene are released out of the reaction system through the reflux condenser. After the reaction was completed, nitrogen gas was introduced into the reaction solvent to remove dissolved phosgene, cooled and filtered, and the inert solvent was distilled off under reduced pressure to obtain an aromatic polyisocyanate.

The amount of phosgene to be introduced is two to ten times stoichiometrically by means of ″ cold heat two-stage phosgenation ″ and ″ phosgenation of amine hydrochloride ″. Inert solvents include aromatic hydrocarbons, fatty acid esters and chlorinated aromatic hydrocarbons. Dichlorobenzene is suitable.

은 1의 화합물인 다음의 일반식(C)The present invention is explained in connection with the following examples. These examples illustrate the invention and do not limit the scope of the invention. In the formula (a), A is a P-phenylene group, m is 0,

Is the compound of formula (1)

Phosphorus polyparaxylylene-polyphenyl-polyisocyanate is demonstrated.

Example 1

General formula

Polyparaxylylene-polyaniline represented by is used as a raw material for phosgenation. The molecular weight distribution of the polyaniline resin is analyzed by high performance liquid chromatography using a GPC column. As a result of analysis, the compound of general formula (b ') is 76.3 wt% when n = 0, 18.7wt% when n = 1, 4.3wt% when n = 2, and 0.7wt% when n = 3 or more. The average molecular weight is approximately 350 and the amine equivalent of the resin according to the acetic acid method of perchloric acid-ice phase is 0.653 eq / 100 g.

682 g of orthodichlorobenzene (ODCB) is charged to a 2 L reaction flask equipped with a stirrer, thermometer, phosgene introduction tube, cooling tube, and dropping funnel. The reaction flask is placed in an ice bucket with stirring to maintain the internal temperature of the flask at 1-2 ° C. Next, phosgene gas was introduced thereto for 2 hours at a rate of 100 g / hour, and a 100 g solution of the polyaniline resin described above in 704 g of orthodichlorobenzene was added dropwise for 45 minutes. In addition, phosgene gas is introduced at a rate of 100 g / hour upon dropping. The temperature at this time is 2-8 degreeC. Next, cold phosgenation is performed at 4-5 ° C. for 30 minutes while introducing phosgene gas at a rate of 100 g / hour. Cold phosgenation results in the formation of a yellowish green slurry in the reaction flask due to the formation of carbamyl chloride and amine hydrochloride. The reaction flask is heated to 140 ° C. for at least 45 minutes by heating with a mantle heater. Charge phosgene gas at a rate of 100 g / hour during the temperature rise. In the course of raising the temperature, the slurry dissolves completely in orthodichlorobenzene with severe release of hydrogen chloride gas. The heat phosgenation is then performed at 140 ° C. for 75 minutes while introducing phosgene gas at a rate of 100 g / hour. The phosgene gas introduced by cold-heat two-stage phosgenation is 525 g of porcine, which is equivalent to 8.1 times of theoretical value. Next, the reaction solution was raised to a temperature of 160 ° C. and nitrogen gas was introduced therein at a rate of 500 ml / min for 2 hours to remove dissolved gas components and to completely decompose unreacted carbamyl chloride. After cooling, a small amount of insolubles is filtered off and distilled under reduced pressure (approximately 1 mmHg) to remove orthodichlorobenzene from the reaction solution. That is, 119.8 g of polyparaxylylene-polyphenyl-polyisocyanate is obtained. As a result, NCO% was 23.5 wt% (theoretical value: 23.5 wt%), hydrolyzable chlorine content was 0.28 wt%, acid content was 0.063 wt%, and residual ODCB content was 47 wt ppm.

The IR spectrum of the aromatic polyisocyanate is shown in FIG.

Example 2

Vacuum distillation purifies 30 g of the aromatic polyisocyanate obtained in Example 1. Break point Approximately 20 g of yellow transparent liquid is obtained under the condition of 210-220 ° C 10.2mmHg and the distillation flask sump temperature of 220-240 ° C. Rapidly solidify the liquid product to form crystals with a melting point of 45-48 ° C. The resultant liquid product by the analysis described below is paraxylylenediphenyl isocyanate, which is a compound represented by formula (C) with n = 0 in Formula (C) representing the aromatic polyisocyanate obtained in Example 1 .

원소분석(C₂₂H₁₆N₂O₂) :

Elemental Analysis (C ₂₂ H ₁₆ N ₂ O ₂ ):

Calculated (%): C; 77.63, H; 4.74, N: 8.23.

Analytical Value (%): C; 77.86, H; 4.35, N: 8.25.

NCO중량% : 분석치 24.65%(계산치 24.69%)

NCO weight%: Analytical value 24.65% (calculated 24.69%)

IR스펙트럼 : 제2도

IR Spectrum: 2nd

H－NMR(CDCl₃, TMS)ppm

H-NMR (CDCl ₃ , TMS) ppm

δ 3.92 (4H-CH _2- × 2), 7.10 (12H PH-H ₄ × 3)

Example 3

4일때 화합물은 1.3wt%이다. 평균분자량은 대략 423이며 과염소산－빙상의 아세트산 방법에 따른 수지의 아민당량은 0.633eg/100g이다.The phosgenation is carried out in the same manner as in Example 1 using polyparaxylylene-polyaniline represented by the formula (b ') as a raw material. The molecular weight distribution of the polyaniline resin used as a raw material is analyzed according to the same analysis method as in Example 1. The analysis results show that the compound of formula (b ') is 56.5 wt% when n = 0, the compound is 26.5 wt% when n = 1, the compound is 10.1 wt% when n = 2, and the compound is 5.6 wt% when n = 3 , n

When 4, the compound is 1.3 wt%. The average molecular weight is approximately 423 and the amine equivalent of the resin according to the acetic acid method of perchloric acid-ice phase is 0.633eg / 100g.

100 g of polyaniline resin was dissolved in 704 g of orthodichlorobenzene and phosgenation was carried out in the same manner as in Example 1. The total phosgene gas introduced in the cold heat two-stage phosgenation is 400 g, which is equivalent to 6.4 times theoretical. Subsequently, dissolved gaseous components are removed from the reaction solution and carbamyl chloride is completely decomposed. After cooling and filtration, distillation under reduced pressure removes orthodichlorobenzene to obtain 103.5 g of polyparaxylylene-polyphenyl-polyisocyanate. The analysis shows that the NCO% is 23.1% by weight, the soluble chlorine content is 0.41% by weight and the acid content is 0.10% by weight.

은 1, n은 0(즉, 방향족 디이소시아네이트)인 화합물을 얻으며 이들은 완전히 새로운 화합물로 신규의 용도를 지닐 것으로 기대된다.The aromatic polyisocyanate obtained according to the method of the present invention is an entirely new compound that has not been known in the past, and thus is expected to have new use as a raw material for polyurethane resins and polyurea resins. Moreover, in the aromatic polyisocyanate, a relatively low molecular weight aromatic polyisocyanate, i.e., in general formula (a), is a P-phenylene group, m is 0,

Silver 1, n is 0 (ie aromatic diisocyanate) compounds are obtained which are expected to have new uses as a completely new compound.

Claims (8)

General formula

(Wherein A represents a phenylene group, an alkylene group, an alkyl substituted phenylene group, a diphenylene group, a diphenyl ether group or a naphthyleneyl group, and R ₁ represents a halogen atom, a lower alkoxy group having 4 or less carbon atoms or a lower alkyl group having 5 or less carbon atoms) R ₁ may be the same as or different from each other and may form a ring,

Is 1 or 2, m is an integer of 0 to 3, n represents an integer of 0 to 300), an aromatic polyisocyanate comprising a mixture of aromatic polyisocyanates represented by. The method of claim 1,

Is 1 and m is 0. 9. 3. The aromatic polyisocyanate of claim 2 wherein n is a polyisocyanate comprising a mixture of aromatic polyisocyanates of 0,1,2,3 or 4. The aromatic polyisocyanate according to claim 3, wherein A is a phenylene group. The aromatic polyisocyanate according to claim 1, wherein A is a phenylene group. The method of claim 5,

Is 1 and m is 0. The aromatic polyisocyanate of claim 1, wherein m is 2 or 3 and two of the R ₁ groups are bonded to form 5 to 6 aliphatic rings which may have side chains. The aromatic polyisocyanate according to claim 5, wherein A is a P-phenylene group and n is 0.

Images