JPH06220306A - Resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition excellent in shock resistance and conductivity. CONSTITUTION:This resin composition is composed of 100 pts.wt. thermoplastic copolyester exhibiting 1.8 to 3.2 relative viscosity and 4 to 50 pts.wt. carbon black and the thermoplastic copolyester resin is a polymer synthesized by using terephthalic acid or its ester forming derivative and a hydrogenated dimer acid or its ester derivative as the acid components and 1,4-butanediol as the main glycol component. The ratio of the hydrogenated dimer acid is 0.5 to 30mol% based on the acid components.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition, more specifically, a resin having excellent impact resistance and high conductivity, which is suitable for electric and electronic parts, packaging materials, containers and automobile parts. It relates to a composition.

[0002]

2. Description of the Related Art Conventionally, as one of methods for imparting conductivity to a resin, a method in which a solid powder having conductivity such as carbon black is kneaded in the resin is known. However, in order to obtain high conductivity, a large amount of solid powder must be blended, and a decrease in mechanical strength, especially impact strength is unavoidable.

On the other hand, polybutylene terephthalate (hereinafter referred to as PBT) has attracted attention as a molding material for injection molding because of its excellent chemical resistance, low water absorption, and moldability. It has been recognized for its great utility value as an automobile part.

However, the PBT resin as a molding material has a drawback that impact strength is small when a notch is formed due to its crystallization behavior, and when carbon black is added to impart conductivity, it has a drawback. There is a drawback that the impact resistance cannot be practically used.

Alloying with a rubber component has been studied as a method for improving the impact resistance of PBT resin. For example, in JP-A-49-97081, PBT resin and ABS resin are mixed to prepare PBT resin. Although the impact strength was improved, when carbon black was added to this composition, the impact strength was reduced and the impact resistance was insufficient.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art and to provide a resin composition excellent in impact resistance and conductivity.

[0007]

That is, according to the present invention, 100 parts by weight of a thermoplastic copolyester resin having a relative viscosity of 1.8 to 3.2 is added to carbon black of 4 to 50.
The thermoplastic copolymerized polyester resin comprises terephthalic acid or its ester-forming derivative and hydrogenated dimer acid or its ester-forming derivative as an acid component, and 1,4-butanediol as a main glycol. The resin composition is a polymer obtained as a component, and the ratio of the hydrogenated dimer acid component is 0.5 to 30 mol% in the acid component.

The present invention will be described in detail below. The acid component of the thermoplastic copolyester resin used in the present invention is
It consists of terephthalic acid and hydrogenated dimer acid or their ester-forming derivatives. The hydrogenated dimer acid is obtained after separating 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 the preferable purity is 99% by weight or more.

A preferred specific example is PRIPOL 1008 manufactured by Unichema Co., which has 36 carbon atoms and is aromatic type /
Alicyclic type / straight chain aliphatic type = 9/54/37 (mol%) dimer acid], PRIPOL 1009 [C36, 13/64/23 (mol%) dimer acid],
Furthermore, as an ester-forming derivative, PR produced by Unichema
IPLAST 3008 [dimethyl ester of PRIPOL 1008] may be mentioned.

It is important that the copolymerization composition ratio of hydrogenated dimer acid, which is a constituent component of the thermoplastic copolyester resin used in the present invention, is 0.5 to 30 mol% with respect to the total of the acid components. , Preferably 1 to 20 mol%.

The copolymerization composition ratio of hydrogenated dimer acid is 0.
If it is less than 5 mol%, the toughness is insufficient, while 30
If it exceeds mol%, the rigidity becomes poor.

It is important that the glycol component of the thermoplastic copolyester resin contains 1,4-butanediol as the main component (70 mol% or more of the total glycol component).

The method for producing the thermoplastic copolyester resin used in the present invention is not particularly limited, and a known method can be used. 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 they are transesterified and then polymerized. The method can be adopted. Various known catalysts, stabilizers, modifiers or additives may be used in the polymerization, esterification reaction or transesterification reaction.

It is important that the thermoplastic copolyester resin has a relative viscosity η _rel of 1.8 to 3.2. When η _rel is less than 1.8, the impact resistance of the composition is poor, while when η _rel exceeds 3.2, molding becomes difficult.

Examples of the carbon black used in the present invention include furnace black, channel black, thermal black, acetylene black, and Ketjen black. Particularly, Ketjen black can provide high conductivity with a small addition amount. It is preferable because it is possible.

In the present invention, it is essential that the amount of carbon black compounded is 4 to 50 parts by weight, especially 5 parts by weight, per 100 parts by weight of the thermoplastic copolyester resin.
-40 parts by weight is preferred.

When the blending amount of carbon black is less than 4 parts by weight, the conductivity is insufficient. On the other hand, when the blending amount of carbon black exceeds 50 parts by weight, not only the impact resistance is insufficient, but also the fluidity at the time of melting the resin is lowered, and kneading and molding become difficult.

The composition of the present invention contains conventional additives such as reinforcing materials (eg, glass fibers, carbon fibers, etc.), antioxidants and heat stabilizers (eg, hindered phenols) within the range not impairing the object of the present invention. , Hydroquinone, thioethers, phosphites and their substitutions and combinations thereof, UV absorbers (eg various resorcinols, salicylates, benzotriazoles, benzophenones, etc.), lubricants and mold release agents (eg stearic acid and its salts). , Montanic acid and its salts, esters, stearyl alcohol, stearyl amide, etc.), dyes (eg nitrosine etc.) and pigments (eg cadmium sulfide, phthalocyanine, carbon black etc.), flame retardants (eg decabromodiphenyl ether, bromine) Polycarbonate, Bromine Polystyrene, halogen type such as brominated epoxy oligomer, melamine or cyanuric acid type, phosphorus type, etc., flame retardant aid (eg antimony trioxide, antimony pentoxide etc.), antistatic agent (eg sodium benzene sulfonate, poly It is possible to add one or more of an alkyl glycol, etc.), a crystallization accelerator (eg, polyethylene glycol, etc.), and an additive impregnation liquid (silicone oil, etc.).

A PBT resin may be further added to the composition of the present invention. The blending amount may be such that the proportion of the hydrogenated dimer acid component is 0.5 to 30 mol% with respect to the total of the acid components constituting the PBT resin and the thermoplastic copolyester resin.

The method for producing the resin composition of the present invention includes:
Various known methods can be used. For example, by using a counter-rotating twin-screw kneading extruder, a thermoplastic copolyester resin is supplied from a hopper port, and carbon black is supplied from a side feed port to form a pellet resin, and then subjected to a molding step. Examples include a method in which the plastic copolymerized polyester resin and carbon black are mixed in a blender, and then pelletized resin is produced by a single-screw kneading extruder, and the pelletized resin is supplied to a molding step.

[0021]

INDUSTRIAL APPLICABILITY The resin composition of the present invention has excellent impact resistance and high conductivity, and is suitable for electric and electronic parts, packaging materials, containers, automobile parts and the like.

[0022]

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

Izod impact strength (notched, 1/4
Inch): ASTM D256 Flexural modulus: ASTM D790 Volume resistivity: ASTM D257 Relative viscosity η _rel : Solvent tetrachloroethane: phenol = 2: 3 (weight ratio), measurement temperature 20 ° C., concentration 1.000
g / dl

Production Example of Thermoplastic Copolymerized Polyester Resin Dimethyl terephthalate, hydrogenated dimer acid (PRIPLAST 3008 manufactured by Unichema), 1,4-butanediol, transesterification and tetra-n-as a polymerization catalyst.
Add butyl titanate with the composition shown in Table 1 and add 210 ° C.
The methanol produced by heating to 100 ° C. was distilled off from the system to carry out a transesterification reaction. After the distillation of methanol was almost completed, the reaction product was transferred to a polymerization vessel and the temperature was raised to 250
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 sample names and relative viscosities η _rel of the obtained thermoplastic copolyester resins.

[0025]

[Table 1]

Examples 1 to 5 and Comparative Examples 1 to 6 Table 2 shows carbon black (Lion Ketjen Black EC) based on 100 parts by weight of the thermoplastic copolyester resin obtained by the above method. The mixture was blended with the composition, pre-mixed, and then melt-mixed with a 30 mm diameter counter-rotating twin screw extruder to obtain pellets.

The pellets obtained were dried under reduced pressure, injection-molded to obtain test pieces, and subjected to physical property tests. The results are also shown in Table 2.

[0028]

[Table 2]

Example 6 50 parts by weight of PBT resin [PBT120 manufactured by Kanebo Co., Ltd.], 50 parts by weight of the thermoplastic copolyester resin [Sample C] obtained by the above method, antioxidant [IRGA manufactured by Ciba Geigy] Knox B-225] 0.1 part by weight, crystal nucleating agent [Hoechst Wax NA manufactured by Hoechst Japan Co., Ltd.
W] 0.5 parts by weight and 10 parts by weight of carbon black [Ketjenblack EC600JD of Lion Co., Ltd.] were mixed and premixed, and then 30 mm diameter different direction rotation 2
It was supplied from the hopper port of the axial extruder and melt-mixed to obtain pellets.

The pellets obtained were dried under reduced pressure, injection-molded to obtain test pieces, and subjected to physical property tests. The results are shown in Table 3.

[0031]

[Table 3]

Comparative Examples 7-9 50 parts by weight of the PBT resin used in Example 6, 0.1 part by weight of the antioxidant used in Example 6 and 0.5 part by weight of a crystal nucleating agent, used in Example 6. 10 parts by weight of carbon black and 50 parts by weight of the impact modifier shown in Table 4 were mixed and premixed, and then melt-mixed in the same manner as in Example 6 to obtain pellets.

The pellets thus obtained were dried under reduced pressure, injection-molded to obtain test pieces, and subjected to physical property tests. The results are shown in Table 4.

[0034]

[Table 4]

Claims (1)

[Claims] 1. A thermoplastic copolymerized polyester resin having a relative viscosity of 1.8 to 3.2 is blended with 4 to 50 parts by weight of carbon black, and the thermoplastic copolymerized polyester resin is terephthalic acid. Or a polymer obtained by using an ester-forming derivative thereof and a hydrogenated dimer acid or an ester-forming derivative thereof as an acid component and 1,4-butanediol as a main glycol component, and having a proportion of a hydrogenated dimer acid component. 0.5 to 30 in the acid component
A resin composition characterized in that the content is mol%.