JPS5852346A - Production of mica-filled polyester composition - Google Patents

Abstract

PURPOSE:To obtain the titled compsn. having excellent mechanical properties, particularly modulus, by adding mica powder having a specified particle size in the polycondensation reaction between terephthalic acid (derivative) and a glycol (derivative). CONSTITUTION:In the production of a polyester by the polycondensation reaction between terephthalic acid or its ester-forming derivative and a 2-4C glycol or its ester-forming derivative, mica powder having an average particle size of 50mu or above is added to the reaction system. Pref. mica is added at a stage where the intrinsic viscority of the polyester is 0.2 or belew, because mica can be extremely uniformly dispersed in the polyester at such a viscosity. A compsn. having excellent mechanical properties, particularly modulus can be obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a mica-filled polyester resin composition. More specifically, the present invention relates to a method for producing a high modulus mica-filled glycester resin composition.

Polyesters, particularly polyethylene terephthalate and polybutylene terephthalate, are widely used in fibers, films, plastic molded products, etc. due to their excellent properties. However, when used as plastic molded products, resin alone does not have sufficient mechanical performance, so in many cases various fillers (e.g. glass fiber, glass flakes, talc, asbestos, mica, etc.) must be filled. used. The polyester and filler are generally mixed using a suitable mixer at normal pressure and at a temperature equal to or higher than the melting point of the polyester. This method is adopted because it is easy and efficient to operate, and it has been believed that the physical properties of the resulting resin composition are hardly affected by differences in the mixing method.

As a result of various studies on methods of mixing mica with polyester, the present inventors unexpectedly found that the mechanical properties of the resin composition obtained may vary greatly depending on the mixing method, and conducted further detailed studies. As a result,
It has been discovered that when a resin composition is produced by adding mica of a specific particle size during the polycondensation reaction of polyester, a composition with particularly excellent mechanical properties (particularly elastic modulus) can be obtained. We have arrived at the present invention.

That is, the present invention provides for the production of polyester by polycondensation reaction of terebutanoic acid or its ester-forming derivative with a glycol having 2 to 4 carbon atoms or its ester-forming derivative, at any stage until the completion of polymerization. Then, mica with an average particle size of 5011 or more was added to the reaction system.
This is a method for producing a mica-filled polyester composition having a high elastic modulus.

The polyester used in the present invention is a polyester containing 80 mol % or more of a polyalkylene terephthalate containing terephthalic acid or its ester-forming derivative as a dicarboxylic acid component and a glycol having 2 to 4 carbon atoms as a diol component. Two specific examples of polyalkylene terephthalate are polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate. The polyester used in the present invention can be copolymerized with components other than those mentioned above within a range of less than 20 mol%61, and copolymerizable components include aliphatic dicarboxylic acids such as adipic acid and basic acid. ,
Aromatic fF dicarboxylic acids such as phthalic acid, isophthalic acid, and 2,6-naphthalene dicarboxylic acid, polycarboxylic acids such as trimellitic acid and pyromellitic acid, oxycarboxylic acids such as P-oxyethoxybenzoic acid, and neopentyl glycol. , 1,6-hexanediol, 1,4-cyclohexane dimetatool, P-xylylene glycol, polyethylene glycol, polytetramethylene glycol and the like. ", f I+ ester can be produced by a conventionally known method. That is, by subjecting terephthalic acid, glycol, and other ingredients if necessary to an esterification reaction, or by esterifying diester of terephthalic acid, glycol, and other ingredients if necessary. Polyester can be obtained by subjecting the components to transesterification reaction and then polycondensation under vacuum.The final degree of polymerization of the polyester can be arbitrarily selected depending on the purpose of use, but generally it is 1N. It is preferable that the viscosity (in a 1:1 phenol/tetrachloroethane solution at 50° C.) is 0.4 or more.

The mica used in the present invention can be appropriately selected from muscovite, phlogopite, synthetic mica, etc., but it is necessary to use one with an average particle size of 50 μm or more. When the average particle size is 50 μm or less, the effect of the present invention is small and a composition having a high elastic modulus cannot be obtained. In addition, there is no particular upper limit to the particle size, but from the viewpoint of surface smoothness of the molded product, 20
It is preferable that it is 00μ or less. More particularly preferred is the case where the average particle size is in the range of 60 to 500 microns.

In the present invention, mica can be added to the polyester-rich condensation reaction system at any stage until the polymerization is completed, but polyester Ob viscous K (in a 1:1 solution of phenol/tetrachloroethane at 30°C) is preferably added at a stage of 0.2 or less. Specifically, mica can be added at the time of charging the polyester raw material, during or at the end of the esterification reaction or transesterification reaction, during pre-condensation, or after pre-*X condensation.

In the present invention, mica may be added to the reaction system as a powder, or may be added in the form of a slurry after being dispersed in glycol or the like. Moreover, mica can also be used after being treated with a conventionally known surface treatment agent (for example, a silane coupling agent, etc.).

The mixing ratio of mica and polyester is not particularly limited, but in order to ensure smooth mixing, it is preferable that the ratio of mica in the composition is 70 M% or less. Further, in order to obtain a composition having a high elastic modulus, it is preferable that the proportion of mica in the composition is 10 quintillion% or more. Furthermore, a particularly preferred range is 20 to 60% coul, and the most preferred range is 60 to 55% direct densification.

In the present invention, in addition to the above-mentioned components, additives commonly used in polyester resins, such as colorants, mold release agents,
Antioxidants, ultraviolet stabilizers, flame retardants, etc. can also be used simultaneously.

The mica-filled polyester composition produced according to the present invention can be molded into any shape such as a plastic molded article or a film. Further, as the molding method, conventionally known molding methods such as extrusion molding and injection molding can be employed.

The present invention will be explained in more detail with reference to Examples below.
The present invention is not limited to such embodiments.

Example 1 Ethylene glycol 70f% dimethyl terephthalate 1
00t1 Phlogopite (manufactured by Marietsuta Resources International, Inc., tin olide mica) 40f (treated with 0.5 coul% of aminosilane coupling agent) having an average particle size of 250 μm is placed in a 500-glass container. Salty acid (
Transesterification was carried out by adding Zn (0 mu) 2" 2 H20) 0.0' f and stirring at 190°C. Methanol (approximately 40 -) close to the theoretical amount
Antimony oxide (20s) 0.04 is distilled out.
t, triphenyl phosphate ((C2H3O
)0.04t was added and the temperature was raised to 280°C. From the time the hot water temperature reached 240°C, the pressure of the reaction system was reduced to about 1
Preliminary polycondensation was carried out while maintaining 50 molecules R at a vacuum degree of 5 to 1 mmHg. Next, reduce the degree of vacuum to 5 to 0.5 mmHH9.
After performing polycondensation while holding for 0 minutes, the polymerization was stopped.

During the reaction, the reaction system was constantly stirred at a speed of 60 rpm.

The obtained mica-filled polyester composition was hot press-molded at 280° C. for 5 minutes to obtain a plate-shaped sample having a thickness of 3 sheets. The mica content in the sample was in the 58-fold form. Table 1 shows the flexural modulus measurement results.

Example 2 A mica-filled polyester composition was obtained in exactly the same manner as in Example 1, except that mica was added after the end of the transesterification reaction and before the start of pressure reduction. Table 1 shows the flexural modulus measurement results.

Example 3 A mica-filled polyester composition was obtained in exactly the same manner as in Example 1, except that mica was added at the prepolycondensation line Y. The flexural modulus measurement results are shown in the table.

Comparison fill Phlogopite (tin olide mica) 2 with an average particle size of 250 s
6.6 F and polyethylene terephthalate (polymerized with the same composition and catalyst composition as in Example 1 except that phlogopite was not added) However, the blood condensation time was 150
minutes, and the storm intensity was increased to 0.78)45.
49 and Plastograph (Braventa, PL-5)
000 type) for 5 minutes at 275° C., normal pressure, and 60 rpm. The resulting composition was hot press-molded at 280° C. for 5 minutes in the same manner as in Example 1 to obtain a plate-shaped sample with a thickness of 3 mm. Table 1 shows the measurement results of the flexural modulus.

Father J; S, 1 Table 1 Flexural Modulus of Polyester Compositions As is clear from Table 1, the mica-filled polyester compositions obtained in Examples all have higher flexural modulus than Comparative Example 1. have.

Example 4 A mica-filled polyester composition was obtained in exactly the same manner as in Example 1 except that phlogopite having an average particle size of 70 μm was used. Table 2 shows the flexural modulus measurement results.

Comparative Example 2 A polyester composition was obtained in exactly the same manner as in Example 1, except that phlogopite (tin olide mica) having an average particle size of 40 μm was used in Example 1. Table 2 shows the flexural modulus measurement results.

Comparative Example 6 A polyester composition was obtained in exactly the same manner as in Example 6 except that phlogopite having an average particle size of 40 μm was used in Example 3. Table 2 shows the flexural modulus measurement results.

Comparative Example 4 A polyester composition was obtained in exactly the same manner as in Comparative Example 1 except that phlogopite having an average particle size of 40 μm was used. Table 2 shows the flexural modulus measurement results.

Table 2/Bending ratio of ester composition! ! As is clear from Table 2, reference 21, when the average particle size of mica is smaller than 50μ, no improvement in the elastic modulus is observed even if mica is mixed under vacuum.

Claims (3)

[Claims] (1) When producing a preester by subjecting terephthalic acid or its ester-forming derivative to a polycondensation reaction with a glycol having 2 to 4 carbon atoms or its ester-forming derivative, j! 'Mica filling is characterized by adding mica powder with an average particle size of 50 tones or more to the reaction system at any stage until the combination is completed. Method for producing a realester composition. (2) The manufactured string according to claim 1, wherein the mica has an average particle size of 60 to 500 μm. (3) If the addition of the mother is the intrinsic viscosity of the polyester [
The manufacturing method according to claim 1, which is carried out at stages L2 and below.