JPS591295B2 - Sunmusubutsuesterjiyugoutainoseizohouhou - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing an ester polymer having an acid anhydride group at its terminal.

More specifically, the production of an acid anhydride ester polymer is characterized in that the transesterification reaction between trimellitic anhydride and polyalkylene ether glycol is carried out in the presence of polyphosphoric acid as a method for more fully and effectively carrying out the transesterification reaction. It is about the method. Conventionally, transesterification reactions with polyols using trimellitic anhydride or its derivatives have involved (1) reaction between chloroformylphthalic anhydride and a glycol component, and (2) reaction between trimellitic anhydride and glycol acetate. and (3) direct transesterification reaction between trimellitic anhydride and a glycol component.

However, in the reaction (1X2), the reaction temperature is relatively low and the reaction product is generated during the reaction, although it has advantages such as obtaining an acid anhydride ester corresponding to the glycol equivalent. Toxic hydrochloric acid gas, acetic acid, and the like not only corrode the reaction equipment, but also cannot be ignored as sources of environmental pollution, posing not only environmental problems but also economical problems.

In addition, the method (3) does not have the above disadvantages, but because the reaction temperature is relatively high (approximately 200°C or higher), trimellitic acid may sublimate during the reaction, low molecular weight glycol may volatilize, etc. occurs, making the chemical equivalent ratio significantly unbalanced and causing a decrease in the acid anhydride group content. However, this trimellitic acid anhydride ester has a wide range of applications and is useful as a raw material for heat-resistant resins, as a curing agent for epoxy resins, and as a material for rubber-like elastic bodies, and there is a strong desire to develop a manufacturing method that is truly economically advantageous. This is where it is being held.

The present inventors have solved the above-mentioned drawbacks, and the glycol group of polyalkylene ether glycol is transesterified with trimellitic anhydride through a stoichiometric reaction, and in order to produce an acid anhydride ester, polyphosphoryl As a result of various studies, we found that the factor that interferes with the polyesterification reaction is the low molecular weight glycol, and that the form in the reaction system is that the surface of the low molecular weight glycol is covered with polyphosphoric acid. It was determined that the situation was the same.

In order to eliminate this phenomenon, a glycol with a large molecular weight is essential, and the polyphosphoric acid used in such a state has a catalytic effect that promotes the transesterification reaction, and also acts as a dehydrating agent. It was discovered that the affinity for is particularly effective for the transesterification reaction, leading to the completion of the present invention. That is, the present invention has 1
Molecular weight 1 having at least two or more hydroxyl groups in the molecule
This is a method for producing an acid anhydride ester polymer, in which about 1 mole of trimellitic acid anhydride is reacted with 1 hydroxyl equivalent of polyalkylene ether glycol having a polyalkylene ether glycol of 000 or more, and the above reaction is carried out in the presence of polyphosphoric acid.

The amount of polyphosphoric acid added in the present invention is 0.1 to 20 parts by weight per 100 parts by weight of the reactants, but if the amount is 0.1 parts by weight or less outside the above range, it will be produced during the reaction. It is not preferred because it is diluted by water and the reaction catalytic effect is significantly reduced.

In addition, if the amount is 20 parts by weight or more, it is preferable to carry out the reaction smoothly, but after the reaction ends, it remains in the produced acid anhydride ester, so when used as an electrical insulating material, It can only be used for special purposes as it significantly reduces the electrical properties of the material. However, it has been found that within the scope of use of the present invention, the remaining phosphoric acid not only has little effect on the test properties, but is actually effective in terms of flame retardancy. The reaction temperature in the present invention is from 150°C to 250°C, but preferably,
A temperature of 180°C to 230°C is chosen.

During the reaction, some water may be distilled out, but the volatilization of glycol components or trimellitic acid, for example,
It was not observed even if the temperature was raised above ℃. Examples of the polyalkylene ether glycol used in the present invention include polymers having at least two or more hydroxyl groups in one molecule, such as polytetramethylene ether glycol, polypropylene ether glycol, and polyethylene ether glycol.

Polyphosphoric acid is basically produced based on phosphorus pentoxide, but it is also composed of condensates with a linear structure, such as orthophosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, and tetrapolyphosphoric acid. It is. The trimellitic anhydride ester obtained by these methods can be mixed with an epoxy resin and cured to make a flexible and elastic cured resin, and can also be made into an imide polymer by reaction with aromatic diamines. It is also possible to add fillers and colorants as necessary.

Next, the present invention will be explained by giving specific examples.

Example 1 115 parts of polytetramethylene ether glycol (molecular weight 1150..0 H value 96) and 20 parts of polyphosphoric acid were placed in a reaction vessel equipped with a stirrer and a reflux device, and
After raising the temperature to .degree. C., 38.4 parts of trimellitic anhydride was added, and the reaction was completed at 220.degree. C. for 4 hours.

The infrared absorption spectrum of the obtained product is 1830? −
111760? -1, 1735? -1 and 1735c
Absorption of acid anhydride groups and ester groups was observed in TIL-1, while absorption of hydroxyl groups of 3400C71L-1 and 1710? No absorption of carboxyl groups was observed in the release of -1, confirming trimellitic acid ester anhydride.

Further, the ring opening rate of the acid anhydride was 2.0%.

Example 2 A four-loaf flask was equipped with a condenser and a stirrer and polypropylene glycol (molecular weight 1200, H value 90) 12
1 part, 38.4 parts of trimellitic anhydride, and 2 parts of polyphosphoric acid were added, and the temperature was raised to 200°C.

During this time, water began to flow out, and heating was continued to 220° C., and about 3.0 parts of water flowed out, and the reaction was completed.
The infrared absorption spectrum of the obtained product is 1830CT
IL-1, 1760CT11-1, 1735CT! L-
1 and 1090CTrL-1 have absorption of acid anhydride groups and ester groups, and 3 of hydroxyl and carboxyl groups.
Absorption of 400CT11-1 and 1710CT1L-1 was not observed at all, confirming trimellitic acid ester anhydride.

Further, the ring opening rate of the acid anhydride was 1.8%. Example 3 Polyethylene glycol (molecular weight 2120, 0H value 53)
Put 106 parts of trimellitic anhydride, 19.2 parts of trimellitic anhydride, and 20 parts of polyphosphoric acid into a four-loaf flask, and raise the temperature to 170°C.
The reaction was allowed to proceed for approximately 5 hours.

During this time, approximately 1.0 part of water was observed to flow out. The infrared absorption spectrum of the obtained product showed the same absorption as in Example 1, and it was confirmed that it was trimellitic acid ester anhydride. Further, the ring opening rate of the acid anhydride was 2.1%. Example
4. Put 130 parts of polypropylene glycol (molecular weight: 25,000, H value: 43), 19.2 parts of trimellitic anhydride, and 0.2 parts of polyphosphoric acid into a four-ring flask, and heat at 180°C for 1 hour, at 200°C for 2 hours, and at 250°C. The mixture was heated for 1 hour, and 1.0 part of water was removed from the reaction system.

The infrared absorption spectrum of the obtained product showed a characteristic absorption at the same position as in Example 1, and it was confirmed that it was trimellitic acid ester anhydride.

Further, the ring opening rate of the acid anhydride was 2.0%. Reference Example Four 192 parts of trimellitic anhydride was added to 1300 parts of polypropylene glycol (molecular weight 2500, 0H value 43) in a 4-lough flask, and the temperature was raised from room temperature to 200°C over 100 minutes while stirring and flowing nitrogen gas. .

Hold at 200°C for 60 minutes and distill off the generated water,
The reaction temperature was further raised to 250° C. and maintained at that temperature for 30 minutes, and then the produced water was completely removed under reduced pressure at 10 mmHg over a period of 30 minutes.

The water distilled off was 13 parts. The infrared absorption spectrum of the obtained product is 1830CTIL-1, 1760?
-1, absorption of acid anhydride groups and ester groups was observed at 1735 cm-1, weak absorption of hydroxyl groups was also observed near 3440CTIL-1, and absorption of carboxyl groups was also observed at 1710cTIL-1.

Claims (1)

[Claims] 1. When reacting about 1 mol of trimellitic anhydride with 1 hydroxyl group equivalent of polyalkylene ether glycol having a molecular weight of 1000 or more and having at least two or more hydroxyl groups in one molecule, the above reaction is carried out in the presence of polyphosphoric acid. A method for producing an acid anhydride ester polymer, characterized in that the method is carried out by: