JP2736906B2 - Method for blending thermoplastic wholly aromatic polyester resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a compounding method for producing an inexpensive thermoplastic wholly aromatic polyester resin composition having excellent heat resistance and moldability.

(Prior Art) Many techniques for blending talc with thermoplastic polyester have been tried. For example, JP-A-60-124649
And JP-A-59-36154.

However, the thermoplastic polyester blended with these talcs does not necessarily have sufficient mechanical strength and heat resistance, especially heat deformation temperature and blister resistance, due to the moisture of the talc, for example, the moisture absorbed even before being dried. Was not. In particular, in the case of resins requiring high heat resistance and high strength such as wholly aromatic polyester, when this is used as a high-temperature type electronic device material such as a microwave oven material, the performance is remarkably deteriorated at high temperatures. There was a problem.

(Problems to be Solved by the Invention) An object of the present invention is to solve the problems of the above-mentioned conventional thermoplastic wholly aromatic polyester blended with talc.

(Means for Solving the Problems) The present invention relates to a method in which 10 to 60% by weight of talc based on the whole composition is mixed with a thermoplastic wholly aromatic polyester resin and melt-kneaded. The talc must be dried in advance so that the amount of water generated is less than 1000 ppm, and the water content of the talc at the time of blending should be kept at the condition that the amount of water generated when heated at 400 ° C. for 1 hour is less than 1000 ppm. This is a method for compounding a thermoplastic wholly aromatic polyester resin composition.

Particularly preferred as the thermoplastic wholly aromatic polyester used in the present invention is at least a compound represented by the general formula: A (co) polymer containing a monomer unit represented by the formula: Etc.

In particular, the use of wholly aromatic polyesters with a melting point of 300 ° C or higher by DSC (differential scanning calorimetry) improves the performance over a wider range, such as thermal deformation temperature, stiffness at high temperatures, and impact resistance. Thus, the compounding effect of the present invention is significantly improved.

The talc used in the present invention is a white powder having a chemical composition represented by Mg ₃ Si ₄ O ₁₀ (OH) ₂ , which has a layered structure and has a weak interlayer bonding force, so that it easily peels and gives a smooth feel. It is also called talc. Fine particles are often used as compounding agents for plastics, and the heat resistance, dimensional stability, etc. are improved by the compounding. The impurity content varies depending on the place of production, but it is preferable to use a high-grade ore having a small amount of impurities as a raw material, and a total of metal impurities such as alumina and iron oxide is preferably 1% or less. The average particle size is not particularly limited, but is preferably 1 to 40 μm.

Examples of commercially available products include Micron White # 5000A (trade name, manufactured by Hayashi Kasei Co., Ltd.) and Mistron 850F
(Trade name, manufactured by Nippon Mistron). These talcs usually contain 0.2-0.5 wt% moisture.

Usually, as a method for measuring the water content of talc, a pigment test method specified in JIS-5001 can be mentioned. This method uses 10 samples
Heat at 5 ° C. to 110 ° C. for 2 hours, and determine the water content from the weight loss.

By the way, when talc is blended with a thermoplastic wholly aromatic polyester, a step of contact-kneading a melt of the thermoplastic wholly aromatic polyester with talc is involved.

A talc blend of a heat-resistant thermoplastic polyester having a melting point of 250 ° C. or higher has not been obtained having sufficient strength and heat resistance.

This is largely due to the fact that moisture generated from talc heated during the compounding hydrolyzes the polyester.

The amount of water contained in the polyester of the present invention is usually
Much less than the amount of water generated from talc.

The water generated during the compounding includes not only the water measured by the JIS-5001 method which is usually performed as described above, but also the physic adsorption water, the chemical adsorption water, the water generated by the decomposition of the hydroxyl group, and the water of crystallization contained in talc. . Since the talc for compounding is a fine powder and is difficult to handle, it is usually used by taking out the talc left in a bag. Regarding moisture, little attention is paid, or even if special attention is paid,
It can be easily dried at a relatively low temperature of around 100 ° C.

However, the inventors of the present invention have examined that, in order to reduce the water generated when talc is heated to the melting point of the thermoplastic wholly aromatic polyester, ordinary heating conditions are insufficient and it is necessary to sufficiently dry at high temperature. It was found that talc had a high hygroscopicity, so that it was necessary to sufficiently mix and control the moisture so as not to absorb the moisture in the air.

The drying conditions are 200 ° C or more and 2 hours or more,
Preferably it is 300 ° C. or more and 2 hours or more, more preferably 400 ° C. or more and 2 hours or more.

After heating and drying, the talc is blended under moisture control so as not to absorb the moisture in the air, that is, to maintain the condition that the amount of moisture generated when heated at 400 ° C. for 1 hour is 1000 ppm or less as the moisture content of talc at the time of blending. Although there is no particular limitation on the method, for example, dry talc is immediately added to a feed hopper heated to a temperature at which the talc does not absorb moisture, and then filled, and the talc that has been heated and dried is subjected to compounding while maintaining a heated state. Is preferred. The heating temperature of the feed hopper at this time is preferably in the range of 100 to 300 ° C. If the content is out of this range, the object cannot be sufficiently achieved. Further, a method of directly connecting the dryer and the extruder is also preferably performed.

The talc at the time of blending is required to have a water generation amount of 1000 ppm or less when the talc is heated at 400 ° C. for 1 hour. If the amount of generated water exceeds 1000 ppm, the original purpose cannot be achieved.

For the measurement of the moisture content, for example, a Karl Fischer moisture meter can be used.

The heat drying may be performed in a vacuum, but industrially, the purpose can be sufficiently achieved by performing the drying in the air.

The amount of talc is 10% by weight based on the composition.
A range of ~ 60% is preferred. When the content of talc exceeds 60% and the content of the thermoplastic polyester resin composition is 40% or less, strength and impact resistance are reduced. When the amount of talc is less than 10%, the effect of the compounding is insufficient.

Talc alone may be used as the compounding agent used in the present invention, or other compounding agents may be added as desired.

As compounding agents, inorganic compounding agents, organic compounding agents, stabilizers,
Examples include antioxidants, ultraviolet absorbers, pigments, dyes, and modifiers. Of these, inorganic compounding agents are particularly important and are often used for improving processability, physical properties and the like. Inorganic compounding agents include molybdenum disulfide, mica, clay, sericite, calcium carbonate, calcium silicate, silica, alumina, aluminum hydroxide, calcium hydroxide, graphite, potassium titanate, glass fiber, carbon fiber, various whiskers, etc. There is.

In this case, the total amount of talc and other compounding agents is desirably not more than 60% by weight based on the composition. Further, other thermoplastic resins and thermosetting resins can be contained as long as the properties intended by the present invention are not impaired.

The thermoplastic wholly aromatic polyester resin composition of the present invention can be produced by various methods. Preferable methods include a method of mixing the resin and talc in an extruder or a kneading apparatus, and a method of coexisting a resin (masterbatch) containing a predetermined talc with the resin at the time of the above-described method or molding. And the like.

The composition obtained by the present invention is usually molded into a desired shape by injection molding and used for various applications.

EXAMPLES Hereinafter, the present invention will be described with reference to examples. However, these examples do not limit the scope of the present invention, but show preferable embodiments of the present invention.

Example 1 Talc (trade name: Talkan Powder PK, Hayashi Kasei Co., Ltd.)
2.40 kg was calcined in an air oven at 500 ° C. for 4 hours, and then cooled to 150 ° C., and immediately dried talc, terephthalic acid, isophthalic acid, 4-hydroxybenzoic acid,
A wholly aromatic polyester made of biphenol (trade name: Zyder, manufactured by Amoco Performance Products of the United States,
<Melting point by DSC> 300 ° C.) 2.60 kg were mixed by a mixer heated to 150 ° C. A twin-screw extruder equipped with a hopper heated immediately to 150 ° C (PC manufactured by Ikegai Iron Works Co., Ltd.)
M-30) at 400 ° C.

For the raw material mixture collected from the feed hopper of the twin-screw extruder, the amount of water generated when heated at 400 ° C. for 1 hour was measured using a Karl Fischer moisture meter (Mitsubishi Kasei Kogyo Co., Ltd., CA-05 and VA-21). ).

The water content of the talc was calculated by subtracting the water content of the resin measured in advance from this value.

The obtained resin pellet was injection molded at a cylinder temperature of 380 ° C. using an injection molding machine (SG-25, manufactured by Sumitomo Heavy Industries, Ltd.) to obtain a tensile test piece and a heat deformation test piece. Tensile strength and tensile modulus are as per ASTM D638, D-
Performed according to 648.

The heat resistance was determined by heating the test piece in an air oven at 260 ° C. for 4 hours and determining whether or not blisters (blisters) had occurred.

 Table 1 shows the results.

Examples 2 and 3 Talc powder used in Example 1 as talc
Example 2 instead of PK (trade name, manufactured by Hayashi Kasei Co., Ltd.)
3 respectively, Rotaruk (trade name, Senko Co., Ltd.)
) And Micron White # 5000A (trade name, manufactured by Hayashi Kasei Co., Ltd.) in the same manner as in Example 1.

 Table 1 shows the results.

Comparative Examples 1 and 2 Tests were performed in the same manner as in Example 1 except that talcum powder PK and Rotalc were used as talcs, respectively, and the heat-drying treatment at 500 ° C. × 4 hours in Example 1 was not performed.

 Table 1 shows the results.

Comparative Example 3 As a talc, mistron 850F (trade name, manufactured by Nippon Mistron) was used and dried at 150 ° C. for 2 hours in an air oven under the conditions of heating and drying at 500 ° C. × 4 hours in Example 1. The test was performed in the same manner as described above.

 Table 1 shows the results.

Example 4 Talc (trade name: Talkan Powder PK, manufactured by Hayashi Kasei Co., Ltd.) was supplied to a continuous heating dryer equipped with a stirrer, and dried under the conditions of a residence time of 1 hour and a drying temperature of 320 ° C. With a twin-screw extruder (PCM-30, manufactured by Ikegai Iron Works Co., Ltd.) with talc directly connected to the dryer outlet
The same wholly aromatic polyester as used in Example 1 (trade name: Zyder, Amoco Performance Products, USA) fed to the extruder at a feed rate of 4.23 kg / hr and fed from the feeder at a feed rate of 4.77 kg / hr (Melting point by DSC> 300 ° C.) and 400 ° C.

400 ° C of talc collected from the pushing device in the middle of the extruder
The amount of generated water when heated for 1 hour was measured in the same manner as in Example 1. Next, the mechanical properties and heat resistance of the resin pellets were measured in the same manner as in Example 1.

 Table 1 shows the results.

Comparative Example 4 The same procedure as in Example 1 was carried out except that the mixing machine and the feed hopper were not heated, and 2.40 kg of talc (trade name: Talkan Powder PK, manufactured by Hayashi Kasei Co., Ltd.) was used. 2.60 kg of an aromatic polyester (trade name: Zyder, manufactured by Amoco Performance Products, USA, <melting point by DSC> 300 ° C.) was kneaded and granulated. The raw material mixture at the time of feeding the feed hopper was sampled to measure the water content, and the water content of talc was calculated in the same procedure as in Example 1. Table 1 shows the physical properties of the resin pellet.

(Effects of the Invention) As described above, the present invention relates to a method of adding a talc having a water generation amount of 1000 ppm or less when heated at 400 ° C for 1 hour to a thermoplastic polyester, and By mixing 10 to 60% by ratio, the strength, elastic modulus, impact resistance and heat resistance of the thermoplastic polyester resin composition can be remarkably improved, and the amount of talc can be increased, resulting in an inexpensive composition. It is possible to provide a product, and to obtain an effect of dramatically expanding a range that can be implemented in a wide range of application fields.

Claims (4)

(57) [Claims] (1) When mixing talc in a weight ratio of 10 to 60% with respect to the whole composition to a thermoplastic wholly aromatic polyester resin and melting and kneading the mixture, the amount of water generated when heated at 400 ° C. for 1 hour is 1000 ppm or less. Talc is preliminarily dried and blended while maintaining the condition that the amount of water in the talc at the time of blending is 1 hour or less when heated at 400 ° C. for 1 hour. A method for blending the aromatic polyester resin composition. 2. The method for blending a thermoplastic wholly aromatic polyester resin composition according to claim 1, wherein the talc is immediately put into a feed hopper heated to a temperature range in which the talc does not absorb moisture after the drying treatment. 3. The heating temperature of the feed hopper is 100 to 300.
The method for blending a thermoplastic wholly aromatic polyester resin composition according to claim 2, wherein the temperature is ℃. 4. The whole aromatic polyester has a melting point of 300 ° C.
4. The method for blending a thermoplastic wholly aromatic polyester resin composition according to claim 3, wherein: