JPS6079037A - Preparation of heat-resistant polyester - Google Patents

Abstract

PURPOSE:To prepare a heat-resistant polyester by reacting a polyester, made from an arfomatic dicarboxylic acid and a glycol component, with a silane compound having two terminal glycidyl ether groups so as to decrease the terminal carboxylic groups. CONSTITUTION:A polyester, made from an aromatic dicarboxylic acid (e.g. terephthalic acid) and a glycol component of 2-6C (e.g. ethylene glycol), is reacted with 0.1-5wt% silane compound having two glycidyl ether groups attached to silicon atoms, so that the terminal carboxylic groups of the polyester may be decreased to 15g equivalent of less per 10<6>g of the polymer to obtain the heat-resistant polyester of the invention. The silane component may be obtained by reacting a compound containing halogen atoms in place of glycidyl groups with glycidyl.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a heat-resistant polyester having a reduced number of terminal carboxyl groups (hereinafter referred to as (Cool)).

Various methods have been proposed to reduce the (C0010) of polyester, but a typical example is known to be a method of reacting polyester with an epoxy compound. However, when the present inventors studied this method, they found that
Depending on the epoxy compound, polyester (COO11
) has poor reactivity with [7.

It was found that there was a problem that the effect was not sufficient.

As a result of intensive research to solve this problem, the present inventors found that
The present invention was achieved based on the discovery that it is effective to react with a specific epoxy compound, a silane compound having two glycidyl ether groups directly bonded to silicon atoms.

That is, the present invention uses an aromatic dicarboxylic acid and a carbon atom having 2 to 6 carbon atoms.
0.1 to 5% by weight of a silane compound having two glycidyl ether groups directly bonded to silicon atoms is reacted with a polyester consisting of a glycol component of The gist of this paper is a method for producing heat-resistant polyester.

In the present invention, polyester means a polycondensate of an aromatic dicarboxylic acid and a glycol having 2 to 6 carbon atoms, and its type is not particularly limited. Moreover, either a homopolymer or a copolymer may be used. As the polycondensation method for polyester, conventionally known methods can be used as they are.

The silane compound in the present invention is represented by the following general formula.

1 (11' and R2 represent a monovalent organic group and may be the same or different.) Specific examples of such silane compounds include the following.

Dimethylsilane diglycidyl ether, methylethylsilane diglycidyl ether, diethylsilane diglycidyl ether, di-n-propylsilane diglycidyl ether, diphenylsilane diglycidyl ether, methylphenylsilane diglycidyl ether, ethylphenylsilane diglycidyl ether, di- -p-tolylsilane diglycidyl ether, methyl-p-)tolylsilane diglycidyl ether. Ethyl-p-tolylsilane diglycidyl ether, phenyl-p-tolylsilane diglycidyl ether. G-m-) Tsursilane diglycidyl ether. Di-tolylsilane diglycidyl ether, dibenzylsilane diglycidyl ether, methylbenzylsilane diglycidyl ether, ethylbenzylsilane diglycidyl ether, phenylbenzylsilane diglycidyl ether, dinaphthylsilane diglycidyl ether.

Methylnaphthylsilane diglycidyl ether, ethylnaphthylsilane diglycidyl ether, phenylnaphthylsilane diglycidyl ether, benzylnaphthylsilane diglycidyl ether, dicyclohexylsilane diglycidyl ether, methylcyclohexylsilane diglycidyl ether.

Ethylcyclohexylsilane diglycidyl ether, cyclohexylphenylsilane diglycidyl ether, benzylcyclohexylsilane diglycidyl ether.

These compounds can be synthesized by reacting glycidol with a compound containing a halogen instead of a glycidyl group as a starting material.

That is, this is a method in which a halogen, preferably chlorine, as a starting material is reacted with glycidol to form a glycidyl ether group.

Even if only one type of such silane compound is used alone,
Two or more types may be used in combination.

The amount of the silane compound used in the present invention is 0.1 to 5% by weight based on the polyester. If this amount is too small, the degree of blocking of (COOII) will be low, and if it is too large, the reaction will proceed satisfactorily, but undesirable problems will occur, such as gelation of the polyester, which will make spinning impossible.

The reaction between the polyester and the silane compound is carried out at a stage after the polyester reaches an intrinsic viscosity of 0.50, by adding the silane compound and taking a time of 3 minutes or more at a temperature higher than the melting temperature of the polyester. be exposed. Note that the intrinsic viscosity here is phenol/tetrachloroethane (1/1 weight ratio)
Measured at 20°C using a mixed solvent. During the reaction, it is of course necessary that the atmosphere is filled with an inert gas such as nitrogen gas, or that active gases such as oxygen that promote the decomposition of polyester are blocked by other methods, and the reaction must be carried out under stirring. It should be done.

The silane compound may be added or mixed before the polycondensation of the polyester is completed, but it may be added to the molten polyester after the completion of one polymerization and then melt-spun, or it may be mixed with the powdery solid polyester and then melt-spun. A method of reacting can also be adopted. Although the reaction proceeds without a catalyst, a preferred catalyst may be used.

In this way, heat resistance can be improved by reacting polyester with 0.1 to 5% by weight of a silane compound (by controlling COOII:l to 15 g equivalent or less per 1068 of the polymer).

Note that in obtaining the polyester of the present invention, it is of course possible to add other additives to the polyester for other purposes.

The final form of polyester in the present invention is fiber.

It may be a film or other molded product.

The polyester with reduced (COO11) obtained by the method of the present invention has significantly improved thermal stability, that is, resistance to hydrolysis and amine decomposition at high temperatures, improving performance in conventional applications and streamlining processes. The improvement in its practical value is remarkable, as it can now be applied to fields that were previously inapplicable.

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

Examples and Comparative Examples The intrinsic viscosity obtained from terephthalic acid and ethylene glycol by a conventional method was 0.73. (COO11) was added to the epoxy compounds shown in Table 1 for 24 g equivalent of polyethylene terephthalate chips per 106 g of polymerized resin.
The mixtures were blended in the amounts shown in , and spun using a spinneret having 192 spinning holes with a diameter of 0.51° C. and 1 wl. The spinning conditions were a temperature of 300'C, a residence time of 3 to 12 minutes, a discharge rate of 300 g/min, and a winding speed of 317 m/min.
The yarn obtained was 8520d/192f. The obtained undrawn yarn was stretched 3.8 times at 90°C in the first stage, then heat-treated at 220°C under tension, and finally
A drawn yarn of 00 d/192 f was obtained.

For the obtained drawn yarn, first, 40T/10cm Z
) After combining the two cords, a 40T/10cm sl was processed to obtain a raw cord of 1500d x 2. This raw cord is coated with a one-bath adhesive solution (Pexul (I).
C1 product) - RFL liquid] per cord 1.
After applying a tension of 0 kg, heat treatment was performed at 240° C. for 3 minutes to obtain a treated cord. Next, in order to examine the heat resistance of the treated cord, the heat resistance strength was measured for a sample prepared under vulcanization conditions of 170°C, IQO kg/self, and 60 minutes. The adhesion of the treated cords was then evaluated using the H-test.

First, the test piece was heated at 150℃ and 100kg/cta.
, was prepared by vulcanization adhesion for 30 minutes, and the adhesive strength was measured.

Table 1 shows the characteristic values of the drawn yarn and treated cord.

Bunacol EX-221 of Comparative Example 5 is a trade name of dibromoneopentyl glycol diglycidyl ether (Nagase Sangyo Co., Ltd.).

The silane compounds of Examples 1 to 4 were crude products obtained by reacting dichlorodimethylsilane, dichlorodiethylsilane, dichlorodiphenylsilane, dichloromethylphenylsilane and glycidol at 0°C in tetrahydrofuran. It was synthesized by distillation under reduced pressure.

According to Examples 1 to 4 that satisfy the requirements of the present invention from Table 1, by adding the silane compound, (C00I+) decreased, the intrinsic viscosity increased, and the heat-resistant strength and heat-resistant strength retention rate were improved. It can be seen that the adhesive strength is also improved.

Furthermore, when the amount of the silane compound added is too small (Comparative Example 2), the effect is insufficient, and when it is too large (Comparative Example 3), the effect is insufficient.
), the polyester gelled and the pressure inside the extruder increased abnormally, making spinning impossible.

Comparative Examples 4 and 5 show known examples, Comparative Example 4 uses a monofunctional epoxy compound, and Comparative Example 5 uses a trifunctional epoxy compound, but in both cases, the intrinsic viscosity decreases due to the addition of the epoxy compound. In Comparative Example 5, the reactivity of the epoxy compound and polyester with (COOID) was poor, and (Co
ol) was not observed.

Claims (1)

[Claims] (1) A silane compound containing two glycidyl ether groups directly bonded to a silicon atom in a polyester consisting of an aromatic dicarboxylic acid and a glycol component having 2 to G carbon atoms.
A method for producing a heat-resistant polyester, which comprises reacting 5% by weight to reduce the amount of terminal carboxyl groups to 15g or less per 106g of polymer.