JPH0948909A - Resin composition for extrusion molding and extrusion molded product thereof - Google Patents

Abstract

(57) Abstract: [PROBLEMS] To provide an extrusion molding resin composition excellent in toughness and antistatic property, and an extrusion molding product thereof. A resin comprising 0 to 95% by weight of a polybutylene terephthalate resin (A) having a relative viscosity of 2.0 or more and 100 to 5% by weight of a thermoplastic copolyester resin (B) having a relative viscosity of 1.9 or more. 5 to 40 parts by weight of carbon graphite (C) and 0 to 10 parts by weight of carbon black (D) are mixed with 100 parts by weight of the mixture, and the thermoplastic copolyester resin (B) is terephthalic acid or its ester. Forming derivative and hydrogenated dimer acid or its ester-forming derivative as an acid component,
1,4-butanediol is obtained as a glycol component, and the proportion of hydrogenated dimer acid component in the total of the acid components constituting the mixture (A) + (B) is 0.5 to 30 mol%. And a thermoplastic resin composition and an extrusion molded article produced by extrusion molding using the resin composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyester resin composition suitable for extrusion molding and having antistatic properties, and an extrusion molded article molded by the extrusion molding method using this composition. Suitable for industrial parts.

[0002]

2. Description of the Related Art Polyester, especially polybutylene terephthalate, is widely used for automobile parts, industrial parts and the like because of its excellent heat resistance and mechanical properties.

Conventionally, as a method for imparting antistatic performance to engineering plastics such as polybutylene terephthalate and polyamide, solid powder having conductivity such as carbon black such as Ketjen black is kneaded and dispersed in a resin. The ones that are done are well known.
However, polybutylene terephthalate has insufficient toughness, and further, the one to which solid powder is added to impart antistatic performance has a problem that the toughness is remarkably lowered.

As a method for improving the toughness of polybutylene terephthalate, for example, JP-B-45-22624 discloses a method of blending polybutylene terephthalate with an α-olefin-vinyl acetate copolymer.

However, when carbon black is added to the resin composition obtained by the above-mentioned method in order to impart antistatic performance, the toughness is significantly reduced.

By the way, since polybutylene terephthalate is excellent in injection moldability, most of it is limited to those obtained by injection molding. However, in recent years, the use of polybutylene terephthalate also tends to become more sophisticated, widespread, and specialized, and it is expected to obtain an extruded product such as a tube by efficiently and economically molding this by an extrusion molding method. Has been done.

However, the polybutylene terephthalate resin generally has the most important characteristic in applying the extrusion molding method, that is, the drawdown property is severe, and it is difficult to obtain a molded product having a desired shape by the extrusion molding method. Is.

As a method of this improvement, for example, a method using polybutylene terephthalate having a high intrinsic viscosity and a high degree of polymerization has been considered, but the effect of improvement is small and insufficient.

Further, a method for improving drawdown property by blending a branching agent such as an epoxy compound has been proposed, but the extrusion moldability is unstable and the gelled product deteriorates the surface of the molded product. There are also problems.

[0010]

SUMMARY OF THE INVENTION The present inventors have made intensive studies to solve the problems of the prior art, and as a result,
The object of the present invention, which has been completed, is to provide a polyester-based resin composition for extrusion molding having excellent toughness and antistatic properties, and an extrusion-molded product thereof.

[0011]

That is, the present invention relates to a polybutylene terephthalate resin (A) having a relative viscosity of 2.0 or more (A) of 0 to 95% by weight and a thermoplastic copolymerized polyester resin (A) having a relative viscosity of 1.9 or more ( B) 100 to 5 parts by weight of a resin mixture consisting of 100 to 5% by weight, 5 to 40 parts by weight of carbon graphite (C) and 0 to 10 parts by weight of carbon black (D), and the thermoplastic copolyester. The resin (B) is obtained by using terephthalic acid or an ester-forming derivative thereof and hydrogenated dimer acid or an ester-forming derivative thereof as an acid component and 1,4-butanediol as a glycol component, and the mixture (A). ) + (B), the ratio of the hydrogenated dimer acid component is 0.5 to 30 mol% in the total of the acid components. It is achieved by a thermoplastic resin composition.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail. In the present invention, the polybutylene terephthalate resin used as the component (A) contains an aromatic dicarboxylic acid or its diester having terephthalic acid or its ester-forming derivative as a main component and 1,4-butanediol as a main component. It is a polymer obtained by reacting a glycol with a known method.

Specifically, terephthalic acid or its ester-forming derivative (such as dimethyl terephthalate) is the main component, and isophthalic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-diphenyldicarboxylic acid, 4,
An aromatic dicarboxylic acid component, which is obtained by appropriately combining 4'-diphenoxyethanedicarboxylic acid, p-oxybenzoic acid, sebacic acid, adipic acid and the like, and 1,4-butanediol as a main component, and an glycol It is polycondensed with a glycol component which is appropriately used in combination with ethylene oxide, trimethylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexanedimethanol and the like.

It is important that the polybutylene terephthalate resin (A) used in the present invention has a relative viscosity ηrel of 2.0 or more when measured at 20 ° C. using a mixed solvent of tetrachloroethane: phenol = 2: 3. is there. ηrel is 2.
If it is less than 0, the drawdown property becomes severe and the shape of the extrusion molded product becomes poor.

In the present invention, it is important that the amount of the polybutylene terephthalate resin (A) is 0 to 95% by weight, particularly preferably 0 to 90% by weight. When the compounding amount of the polybutylene terephthalate resin (A) exceeds 95% by weight, that is, the thermoplastic copolyester resin (B)
If the ratio is less than 5% by weight, the toughness becomes insufficient.

The acidic component of the thermoplastic copolyester resin (B) used in the present invention mainly comprises terephthalic acid and hydrogenated dimer acid.

The hydrogenated dimer acid is obtained after separation of by-products such as trimer acid and monomer acid by separation and hydrogenation from a low polymer of unsaturated fatty acid by a clay catalyst, and a preferable purity is 99% by weight or more. Is. As a preferred specific example, PRIPOL 10 manufactured by Unichema
08 (36 carbon atoms, aromatic type / alicyclic type / linear aliphatic type = 9/54/37 (mol%) dimer
Acid), PRIPOL1009 (13/64 with 36 carbon atoms)
/ 23 (mol%) dimer acid), and PRICHELAST 300 manufactured by Unichema as an ester-forming derivative.
8 (dimethyl ester of PRIPOL 1008). The copolymerization composition ratio of the hydrogenated dimer acid which is a constituent component of the thermoplastic copolyester resin (B) is not particularly limited, but is preferably 1 to 50 mol%.

As the glycol component of the thermoplastic copolyester resin (B) of the present invention, 1,4-butanediol as the main component (for example, 70 mol% or more) is used as the polybutylene terephthalate resin (A). It is essential for compatibility.

The method for producing the thermoplastic copolyester resin (B) in the present invention is not particularly limited and can be carried out according to a known method. For example, terephthalic acid or its ester-forming derivative, hydrogenated dimer acid or its ester-forming derivative, and 1,4-butanediol are directly or simultaneously esterified, or after transesterification, A method of polymerizing can be adopted. Various known catalysts, stabilizers, and the like in the polymerization or esterification reaction, transesterification reaction,
A modifier or an additive may be used.

The thermoplastic copolyester resin (B) of the present invention has a relative viscosity ηrel measured at 20 ° C. using a mixed solvent of tetrachloroethane: phenol = 2: 3,
It is essential that it is 1.9 or more. When ηrel is less than 1.9, the drawdown property becomes severe and the shape of the extrusion molded product becomes poor.

The composition of the present invention comprises the above (A) and (B).
It is important that the proportion of the hydrogenated dimer acid component is 0.5 to 30 mol%, and preferably 1 to 20 mol%, with respect to the total of the acidic components constituting the. When the proportion of the hydrogenated dimer acid component is less than 0.5 mol%, the extruded product obtained by the extrusion molding is brittle, while on the other hand, 30 mol%
If it exceeds, the rigidity will be poor, and the extruded product will bend when held horizontally by a cantilever.

Examples of carbon graphite (C) used in the present invention include man-made products and natural products. Natural products include scales, scales, and soils, but any of them can be used. The average particle size is preferably 500 μm or less, and particularly preferably 50 μm or less from the viewpoint of imparting conductivity.

In the present invention, the blending amount of carbon graphite (C) is importantly 5 to 40 parts by weight, especially 7 to 30 parts by weight, relative to 100 parts by weight of the resin mixture comprising (A) and (B). Parts by weight are preferred. If it exceeds 40 parts by weight, the extruded product obtained by extrusion becomes brittle. On the other hand, if it is less than 5 parts by weight, the drawdown property becomes severe and the shape of the extrusion molded product becomes poor.

Carbon black (D) used in the present invention
Examples thereof include furnace black, channel black, thermal black, acetylene black, ketjen black, and the like. Among them, utchen black is particularly preferable because it has excellent antistatic properties when dispersed in a resin.

In the present invention, it is essential that the amount of carbon black (D) is 0 to 10 parts by weight based on 100 parts by weight of the resin mixture comprising (A) and (B).
Particularly, 0.5 to 7 parts by weight is preferable. If it exceeds 10 parts by weight, the extrusion-molded product obtained by extrusion molding becomes brittle.

The composition of the present invention contains conventional additives such as antioxidants and heat stabilizers (eg hindered phenols, hydroquinones, thioethers, phosphites and their substitutions) within a range not impairing the object of the present invention. Body and combinations thereof), UV absorbers (eg resorcinol, salicylate, benzotriazole, benzophenone, etc.), lubricants and mold release agents (eg montanic acid and its salts, stearic acid and its salts, stearyl alcohol,
One or more kinds of colorants including stearylamide, silicone resin, etc., dyes (eg, nitrocin, etc.) and pigments (eg, cadmium sulfide, phthalocyanine, etc.), additive impregnation liquids (eg, silicone oil), etc. can be added.

The composition of the present invention contains a small amount of other thermoplastic resin (for example, olefin resin such as polyethylene, polypropylene, ethylene copolymer, acrylic resin, fluororesin, polyamide, polyacetal, polycarbonate, polysulfone, polyphenylene oxide). , A graft copolymer such as polyester, ABS resin, MBS resin, etc.) can be blended.

It is preferable that all components of the thermoplastic resin composition of the present invention are sufficiently dispersed until it becomes an extrusion molded product. As a method for this, for example, there is a method in which pellet-shaped resin is produced by using a different-direction rotating twin-screw extruder, and the pelletized resin is subjected to an extrusion molding step.

The extrusion molding method of the present invention may be carried out by an ordinary method using an extruder which is generally used for extrusion molding of thermoplastic resins.

That is, the above-mentioned thermoplastic resin composition is plasticized by an extruder. For example, in the case of a pipe-shaped extrusion-molded product, it is extruded from an annular die and cooled and solidified by a sizing die to form a shape, for example, a rod-like shape. In the case of, the product is extruded from a pipe-shaped die and cooled with water or the like.

[0031]

INDUSTRIAL APPLICABILITY The present invention relates to a polyester resin composition suitable for extrusion molding and having an antistatic property, and an extrusion molded article molded by the extrusion molding method using this composition. Suitable for industrial parts.

[0032]

EXAMPLES The present invention will be specifically described below with reference to examples. The physical properties were evaluated according to the following methods.

Relative viscosity η rel: solvent tetrachloroethane: phenol = 2: 3 (weight ratio), measurement temperature
20 ° C, concentration 1.000 g / dl Tensile elongation at break: ASTM D638 Test speed 50 mm / min Volume resistivity: ASTM D257 Drawdown index: Length of resin extruded from orifice of melt indexer reaches from 0 mm to 10 mm The ratio of the time required to reach 90 mm to the time required to reach 100 mm was defined as the drawdown index. A resin with no drawdown has a drawdown index of 1, and the larger the drawdown, the larger the index. (Melt indexer conditions: temperature 250 ° C, preheating time 6 minutes,
Orifice diameter 2 mm) Extruded product shape: ◯ (good), × (poor). Extruded product rigidity: When the end of a molded product having a length of 5 cm was horizontally cantilevered, it was represented by ○ (maintains the shape) and × (bends by its own weight).

(Production Example of Thermoplastic Copolymerized Polyester Resin) Dimethyl terephthalate, hydrogenated dimer acid (PRIPLAST 3008 manufactured by Unichema), transesterification to 1,4-butanediol and tetra- as a polymerization catalyst.
n-butyl titanate was charged into a transesterification tank, and 21
Methanol produced by heating to 0 ° C. was distilled out of the system, and transesterification was performed. After the methanol distillation was almost completed, the reaction product was transferred to a polymerization tank, and the temperature was reduced to 250 over 1 hour.
The temperature was brought to 0 ° C and the degree of vacuum to 0.5 mmHg, and then polycondensation was performed. Table 1 shows the respective compositions and the sample names and the relative viscosities ηrel of the thermoplastic polyester resins obtained.

[0035]

[Table 1]

Examples 1 to 3, Comparative Examples 1 to 5 Various thermoplastic copolyester resins obtained by the above method, and polybutylene terephthalate resin (PBT119 manufactured by Kanebo Co., relative viscosity ηrel = 1.9, or Kanebo PBT124, relative viscosity ηrel = 2.4) is shown in Table 2.
The composition shown in Table 1 was added to 100 parts by weight of this resin mixture, and an antioxidant (IRGANOX 1 manufactured by Ciba-Geigy) was used.
330) 0.1 part by weight, talc (PKD manufactured by Hayashi Kasei Co., Ltd.) as a crystal nucleating agent 0.1 part by weight, carbon graphite (manufactured by Nippon Graphite Co., HOP average particle size = 2 to 3 μm) 10
By weight, 2 parts by weight of Ketjen Black (Ketjen EC600, manufactured by Lion Co., Ltd.) as carbon black were blended, pre-mixed and then melt-mixed with a 30 mm diameter counter-rotating twin-screw extruder to obtain pellets.

After the obtained pellets were dried under reduced pressure, they were subjected to injection molding to obtain test specimens, which were subjected to physical property tests. The results are shown in Table 2.
Shown in

Further, using this pellet, an extruder (manufactured by Rikua Co., Ltd., single shaft, screw diameter = 30 mmφ, L
/ D = 26, compression ratio = 3), cylinder temperature 240
℃, using a sizing die pipe-shaped (diameter = 10
φ, thickness = 0.5 mm) was extruded. Table 2 shows the results.
It shows together.

[0039]

[Table 2]

In Comparative Examples 1 and 2, the relative viscosity ηrel of the thermoplastic copolymerized polyester resin (B) and the polybutylene terephthalate resin (A) used in Comparative Examples 1 and 2
Therefore, the drawdown of the resin composition was severe and the shape of the obtained pipe was poor. In addition, Comparative Example 3 in which the thermoplastic copolymerized polyester resin (B-2) was contained in a small amount
However, the improvement effect was small, and the obtained extrusion molded product had a small tensile elongation at break and had insufficient toughness. In Comparative Example 4 in which the proportion of hydrogenated dimer acid in the resin composition is small, the extruded product obtained is brittle, while in Comparative Example 5 in which the amount is too large, the molded product lacks rigidity and bends when horizontally cantilevered. Met.

Examples 4-5, Comparative Examples 6-8 25 parts by weight of the thermoplastic copolyester resin (Sample B-2) obtained by the above method, polybutylene terephthalate resin (PBT124 manufactured by Kanebo Co., relative viscosity ηre
l = 2.4) 75 parts by weight, 0.1 part by weight of the antioxidant used in Example 1, 0.1 part by weight of talc used in Example 1 as a crystal nucleating agent, carbon graphite (manufactured by Nippon Graphite Co., Ltd., CP average particle size = 7 μm), and Ketjenblack used in Example 1 as carbon black were blended in the composition shown in Table 3, pre-mixed, and then melt-mixed with a 30 mm diameter counter-rotating twin-screw extruder, Pellets were obtained.

The pellets thus obtained were dried under reduced pressure and then subjected to injection molding to obtain test pieces, which were then subjected to a physical property test. Table 3 shows the results.
Shown in

Further, the pellets were extruded in the same manner as in Example 1. The results are also shown in Table 3.

[0044]

[Table 3]

The extruded product obtained in Comparative Example 6 containing too much carbon graphite (C) had a low tensile elongation at break and was brittle, while in Comparative Example 7 containing a small amount of the compound, drawdown was performed. The moldability was not improved and the shape of the molded product was poor. The extrusion molded product obtained in Comparative Example 8 in which the amount of Ketjen Black (D) was too large was also brittle.

Claims (2)

[Claims] 1. A polybutylene terephthalate resin (A) having a relative viscosity of 2.0 or more (A) of 0 to 95% by weight and a thermoplastic copolyester resin (B) having a relative viscosity of 1.9 or more of 100 to 5% by weight. 5 to 40 parts by weight of carbon graphite (C) and 0 to 10 parts by weight of carbon black (D) are mixed with 100 parts by weight of the resin mixture, and the thermoplastic copolyester resin (B) is terephthalic acid or its compound. An ester-forming derivative and hydrogenated dimer acid or an ester-forming derivative thereof as an acid component,
1,4-butanediol is obtained as a glycol component, and the proportion of hydrogenated dimer acid component in the total of the acid components constituting the mixture (A) + (B) is 0.5 to 30 mol%. And a thermoplastic resin composition. 2. An extrusion molded article produced by extrusion molding using the resin composition according to claim 1.