JPS592286B2 - Trimelitosanester Musubunoseizouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing trimellitic acid ester anhydride.

For more details, please check the temperature at 200°C to 250°C in advance.
The present invention relates to an industrially advantageous method for producing highly pure trimellitic acid ester anhydride from polyalkylene ether polyol heated to 0.degree. C. and trimellitic anhydride. Conventionally, polyol trimellitic acid ester anhydride has generally been produced by reacting polyol polyacetate and trimellitic anhydride.

Therefore, in the method for producing trimellitic acid ester anhydride, one of the starting materials, polyol polyacetate, is first produced, and the hydroxyl groups of the polyol are processed in the presence of acetic acid or an acetylating agent. Obtained by acetylating. In this case, not only are expensive reagents required and used in larger quantities than necessary, but it also takes a long time to complete the reaction, which seriously impairs economic efficiency and also causes problems such as the reaction apparatus becoming dog-shaped. It has its drawbacks. In addition, when reacting polyol polyacetate with trimellitic anhydride, this reaction is slow, and an operation step for removing and recovering acetic acid liberated by the transesterification reaction from the reaction system becomes an essential means, and the equipment required for distillation recovery becomes enormous. In addition, the operation is extremely complicated and difficult, and there is also the problem of corrosion of the equipment by acetic acid, which is extremely disadvantageous from an industrial perspective.

In order to eliminate this drawback, Japanese Patent Publication No. 45-29974 describes a method for obtaining trimellitic acid ester anhydride by directly reacting a polyol with trimellitic anhydride.

That is, the reaction is said to proceed as shown in the following equation (1).

However, Ind. Eng. Chem,. PrOdl
Res,. Devel Rabbit, VOLl9(3)403(1
970) states that by-products are produced and trimellitic acid ester anhydride cannot be obtained with high purity and high yield.

That is, first, the anhydride group and hydroxyl group of trimellitic anhydride react to produce a diester, and then a triester and the like are produced by the transesterification reaction.

However, the present inventors have conducted various studies on a method for directly reacting a polyol and trimellitic anhydride to produce highly pure trimellitic acid ester anhydride industrially and advantageously, overcoming the drawbacks of the conventional methods as described above. As a result of stacking, two polyalkylene ether polyols and trimellitic anhydride, each heated to 200°C to 250°C, were combined.
By carrying out an esterification reaction at 00°C to 250°C,
The present invention was completed based on the discovery of a completely new fact that it is possible to eliminate all of the above-mentioned drawbacks and achieve the above-mentioned object.

That is, in the present invention, each temperature is heated to 200°C to 2.
This relates to a method for producing trimellitic acid ester anhydride, which is characterized in that a polyalkylene ether polyol heated to 50°C and trimellitic anhydride are subjected to an esterification reaction at 200°C to 250°C.
By dehydrating and condensing polyalkylene ether polyol heated to 250°C and trimellitic anhydride at 200°C to 250°C, only free carboxyl groups are esterified without ring-opening of the carboxylic anhydride groups of trimellitic anhydride. trimellitic acid ester anhydride of polyalkylene ether polyol can be obtained very easily in high yield and high purity, and the reaction can proceed rapidly and produce a remarkable industrial effect. It concerns the manufacturing method.

Examples of the polyalkylene ether polyol used in the present invention include ethylene oxide, 1,2-propylene oxide, 1,2-butylene oxide, 1,3
-butylene oxide, 2,3-butylene oxide,
Examples include polyalkylene ether polyols obtained by ring-opening polymerization or ring-opening copolymerization of epoxy compounds such as 1,4-epoxycyclohexane or other epoxy compounds, oxacyclobutane compounds, and oxacyclopentane compounds, or cyclic ethers. .

Also used for the purpose of the present invention are ether type polyols, which are based on polyhydric alcohols such as glycerin and pentaerythritol, and are polymerized (or copolymerized) with the above-mentioned cyclic ethers. The amount of trimellitic anhydride used is 1 of the polyalkylene ether polyol.
It is used in an amount of about 1 mole based on the hydroxyl equivalent; when it is less than about 1 mole, by-products are produced, and when it is more than about 1 mole, trimellitic anhydride remains, which is unfavorable in terms of reaction efficiency.

In carrying out the method of the present invention, by directly dehydrating and condensing polyalkylene ether polyol and trimellitic anhydride, the carboxylic anhydride group of trimellitic anhydride is not ring-opened, and its carboxyl group is is esterified to obtain the corresponding trimellitic acid ester anhydride, and the reaction temperature is in the range of 200°C to 250°C.

If it is higher than this range, the polymer chains of the polyalkylene ether polyol used will decompose and side reactions will occur, and if it is lower than this range, by-products will be produced, resulting in high yield.
Both are unfavorable because they are difficult to obtain with high purity. Therefore, the trimellitic acid ester anhydride of polyalkylene ether polyol obtained by the method of the present invention has many uses, especially the trimellitic acid ester of polyalkylene ether polyol having a molecular weight in the range of about 500 to 12,000. Anhydrides are used as curing agents for epoxy resins, etc. to obtain cured resins with excellent electrical properties, mechanical properties, and especially flexibility, and are also used as curing agents for epoxy resins, etc. 1 such as aniline, 4,4'-methylene dianiline, etc.
It is extremely industrially advantageous, as a polyimide resin with good flexibility can be obtained by reacting with grade diamine.

Next, the method of the present invention will be explained in detail with reference to Examples.

Example 1 1046 parts of polyethylene glycol (molecular weight 1050.0 H value 07) heated to 210°C (
parts by weight, hereinafter the same) and 384 parts of trimellitic anhydride heated to 240°C were added, and the mixture was heated at 230°C in a nitrogen gas stream while stirring.
The mixture was allowed to react for 2 hours.

During this time, 35.97 ml of water was generated (theoretical amount is 36.9 ml of water).
07). Approximately 250 at 5 to 8 mmHg under reduced pressure
The reaction was carried out by keeping the temperature at .degree. C. for 30 minutes.

The acid anhydride purity of the obtained product was determined to be 99.9 by chemical analysis.
It was 5%.

1830 in IR (infrared absorption spectrum)? -1,
1760? -1, 1735? -1 and 1090CfL
-1 has an absorption, and anhydrous carboxyl group and ester group (
and ether groups), while 3400C
TIL-1 and 1710? Absorption of the hydroxyl group and free carboxyl group of -1 was not observed, and it was confirmed to be trimellitic acid ester anhydride. Example 2 2120 parts of polyethylene glycol (molecular weight 2120, 0H value 53) heated to 210°C and 384 parts of trimellitic anhydride heated to 240°C were placed in a four-bottle flask, and the mixture was heated at 230°C 2 in a nitrogen gas stream while stirring. Allowed time to react.

During this time, 35.87 water was generated (theoretical amount is 36 water,
07). The acid anhydride purity of the obtained product was 99.
It was 0%. It showed absorption similar to that of Example 1 in the corresponding IR, and was confirmed to be trimellitic acid ester anhydride. Example 3 1240 parts of polypropylene glycol (molecular weight: 120010 H value: 90) heated to 220°C and 384 parts of trimellitic anhydride heated to 240°C were placed in a four-bottle flask, and the mixture was heated at 235°C under stirring in a nitrogen stream. Allow time to react.

During this time, 35.97 ml of water was generated (theoretical amount is 36.9 ml of water).
07). The acid anhydride purity of the obtained product was 99.
It was 5%. 1830crrL-1,1 in IR
760 (177!-11735Cr1L-1 and 10
Absorption was observed in 90CITL-1, indicating the presence of anhydride carboxyl groups and ester groups (and ether groups), while absorption of hydroxyl groups and free carboxyl groups in 3400cr1L-1 and 1710CT1L-1 was not observed, and the corresponding trimellito It was confirmed to be an acid ester anhydride. Example 4 1300 parts of polypropylene glycol (molecular weight 2500, 0H value 43) heated to 220°C and 192 parts of trimellitic anhydride heated to 240°C were placed in a four-bottle flask, and the mixture was heated at 235°C under stirring in a nitrogen stream. The mixture was allowed to react for 2 hours.

During this time, 17.57 g of water was generated (theoretical amount is 18 g of water).
07). The obtained product showed absorption similar to that of Example 3 in IR and was confirmed to be trimellitic acid ester anhydride. Example 5 Polytetramethylene glycol (molecular weight 1150, 0H value 96) heated to 230°C was placed in a four-loaf flask.
0 part and 384 parts of trimellitic anhydride heated to 240°C were added, and the mixture was reacted with stirring at 240°C for 1.5 hours in a nitrogen gas flow.

During this time, 35.87 g of water was generated (theoretical amount is 36.8 g of water).
07). The acid anhydride purity of the obtained product was 99.
It was 5%.

1830 (:7L-1, 1760?-1,
1735? There are absorptions at -1 and 1090cfn-1, indicating the presence of anhydrous carboxyl groups and ester groups (and ether groups), while at 3400? -1 and 171
No absorption of the hydroxyl group or free carboxyl group of 0cTrL-1 was observed, and it was confirmed to be the corresponding trimellitic acid ester anhydride. Example 64 flasks, 2
1040 parts of polytetramethylene glycol (molecular weight 1980, 0H value 54) heated to 30°C and 192 parts of trimellitic anhydride heated to 240°C were added, and reacted at 240°C for 1.5 hours under stirring in a nitrogen stream. Ta.

During this time, 17.57 water was generated (theoretical amount is 18 water,
07). The purity of the acid anhydride of the obtained product is 99
．． It was 0%.

It showed absorption similar to that of Example 5 in IR (infrared absorption spectrum), and was confirmed to be the corresponding trimellitic acid ester anhydride. San JJ? Put 1170 parts of polytetramethylene glycol (molecular weight 1150, 0H value 96) and 384 parts of trimellitic anhydride into a four-piece H3 chestnut flask, and heat the mixture to 180°C for 30 minutes and 235°C for another 30 minutes in a nitrogen gas stream while stirring. The temperature was raised to 23
The reaction was carried out at 5°C for 2 hours.

During this time, 33.87 g of water was generated (theoretical amount is 36 g of water).
07). The acid anhydride purity of the product was 89.5%. Also in IR, some absorption of free carboxyl groups of 1710-1 was observed. As described above, in the method of the present invention, trimellitic acid ester anhydride can be obtained very easily in high yield and high purity, and therefore has great industrial value.

Claims (1)

[Claims] 1. Polyalkylene ether polyol with a molecular weight of 500 to 12,000 and trimellitic anhydride, each heated to 200 to 250 °C in advance, are heated to 200 to 250 °C.
A method for producing trimellitic acid ester anhydride, which comprises carrying out an esterification reaction.