JPH0721041B2 - Resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a reinforced thermoplastic polyester resin composition which gives a molded article having a high crystallization rate, and excellent impact resistance and moisture resistance.

[Problems to be Solved by Conventional Techniques and Inventions] Conventionally, polyethylene terephthalate has been widely used for fibers, films, molding materials and the like because of its excellent mechanical properties and chemical properties.

However, polyethylene terephthalate has a relatively low crystallization rate compared to the same polyester material, polybutylene terephthalate, and a mold temperature of 140 ° C or higher is required when injection molding is performed as a molding material. . Further, polyethylene terephthalate has relatively low impact resistance, and its improvement is desired.

As a method for improving such a defect, a method using various crystallization accelerators is known.

For example, JP-B-48-4097 and JP-B-48-4098 propose a method of adding an organic acid metal salt, and JP-B-55-47059 proposes a method of adding a plasticizer and an ionomer.

However, these methods can reduce the mold temperature during injection molding to a practical level, but the impact resistance is not improved.

On the other hand, a method has also been proposed in which a soft segment is copolymerized to increase the crystallization rate and at the same time improve impact resistance. For example, in Journal of Polymer Science, Vol. 8, p. 1 (1952), there is a method of copolymerizing polyethylene glycol, and in JP-A-61-243854 and JP-A-63-108054. A method of copolymerizing a polymer obtained by adding an alkylene oxide to a polyalkylene glycol or a bisphenol type compound is disclosed.

However, when a soft segment, especially a copolymer of polyalkylene glycol is used, the moisture resistance of the molded article is lowered. A molded article made of a composition reinforced with glass fibers has a remarkable decrease in mechanical strength due to moisture absorption, and its improvement is desired.

Although a method using an epoxy compound has been proposed as a method for improving the moisture resistance as described above, the use of an epoxy compound slows down the crystallization rate, and any epoxy compound may not be used. Further, even if the moisture resistance is improved, there is often a problem that other properties are not sufficiently improved, and it is difficult to obtain a resin composition having various properties in a well-balanced manner.

An object of the present invention is to provide a reinforced polyethylene terephthalate resin composition which gives a molded article having an excellent balance of mechanical strength, impact resistance, moisture resistance, processability and the like.

[Means for Solving Problems] The present invention has been made to achieve the above object, and includes (A) general formula (I): (In the formula, R ¹ represents a C _{2 to} C ₄ divalent hydrocarbon group, X represents a divalent bonding group or a direct bond, and m and n are each 5
A polyether having a main part represented by an integer of 20 to 20 (hereinafter, also referred to as a polyether represented by the general formula (I)) 5 to 90 (% by weight, the same hereinafter) and polyethylene terephthalate 10 to 95% Copolymer component 100 consisting of
Parts (parts by weight; hereinafter the same), (B) 10 to 150 parts of glass fiber, and (C) 5 to 100 parts of a copolymer consisting of an α-olefin and a glycidyl ester of an α, β-unsaturated carboxylic acid. Concerning the resin composition, it is remarkable that the use of the composition provides a reinforced polyethylene terephthalate resin composition which gives a molded article having a desired balance of mechanical strength, impact resistance, moisture resistance, processability and the like. The effect is played.

[Examples] Polyethylene terephthalate in the present invention means that at least 90 mol% of terephthalic acid or its ester-forming derivative is used as an acid component, and at least 90 mol% of ethylene glycol or its ester-forming derivative is used as a glycol component. What can be used.

As an acid component other than terephthalic acid which is used in an amount of less than 10 mol%, other aromatic dicarboxylic acid having 6 to 14 carbon atoms and 4 carbon atoms
To aliphatic dicarboxylic acids having 8 to 8 carbon atoms or alicyclic dicarboxylic acids having 8 to 12 carbon atoms, and specific examples thereof include phthalic acid, isophthalic acid, 2,6-naphthalenedicarboxylic acid and 4,4'- Examples thereof include diphenyldicarboxylic acid, adipic acid, sebacic acid and cyclohexanedicarboxylic acid.

Moreover, as a diol component other than ethylene glycol used in an amount of less than 10 mol%, an aliphatic diol having 3 to 10 carbon atoms, an alicyclic diol having 6 to 15 carbon atoms, or 6 to 15 carbon atoms
And aromatic diols thereof, and specific examples thereof include propane-1,3-diol and butane-1,4-
Diol, pentane-1,5-diol, hexane-1,6-
Diol, cyclohexane-1,4-dimethanol, 2,2-
Dimethylpropane-1,3-diol, 2,2-bis (4'-
Examples thereof include hydroxycyclohexyl) propane, 2,2-bis (4'-hydroxyphenyl) propane and hydroquinone.

General formula (I) in the present invention: In the formula, R ¹ is a C _{2 to} C ₄ divalent hydrocarbon group, and X is, for example, Represents a divalent linking group such as —CH ² —, —S—, —SO ₂ —, —CO— or a direct bond, and (m + n) R ¹ 's need not be the same, m and n are respectively A polyether having a main part represented by an integer of 5 to 20) is preferable for improving the crystallization rate and impact resistance of the resin composition of the present invention.

Both ends of the polyether are usually hydroxyl groups, but the terminal is not limited to this and may be any one that can be copolymerized with the polyethylene terephthalate component.

The polyether represented by the general formula (I) is 5 to 90 parts, preferably 10 to 60 parts, and particularly preferably 25 to 100 parts of the component (A) consisting of this and polyethylene terephthalate.
Contains ~ 50 parts. If the amount is less than 5 parts, the effect of improving the crystallization rate cannot be expected, and if it exceeds 90 parts, the mechanical strength of the molded product,
Moisture resistance is significantly reduced, which is not preferable.

The copolymerization component (hereinafter referred to as the component (A)) comprising polyethylene terephthalate and the polyether represented by the general formula (I) in the present invention usually has an intrinsic viscosity of 0.35 to 1.20 (phenol / tetrachloroethane = 50/50 ( Weight ratio), 0.5% concentration, measured at 25 ° C). The intrinsic viscosity is preferably 0.40 to 1.00 and particularly preferably 0.50 to 0.80 from the viewpoint of improving the crystallization rate and the mechanical strength in a well-balanced manner.

The component (A) composed of polyethylene terephthalate and the polyether represented by the general formula (I) may be produced by block copolymerization in a polyethylene terephthalate synthesis reaction vessel, and reacted by using an extruder. It may be produced, or may be produced by copolymerization by an ordinary method. More specifically, for example, a high-viscosity horizontal twin-screw reactor having a temperature of 280 ° C. and an average residence time of 30 minutes,
The component (A) (copolymer component) can be obtained under the condition that the degree of vacuum is 1 Torr or less.

The glass fiber used in the present invention usually has a diameter of 1 to 20 μm,
The length is about 0.05 to 50 mm. The glass fiber may be treated with a coupling agent, or may be one using a binder, but from the viewpoint of improving impact resistance, moisture resistance and the like which are the effects of the present invention, the coupling Γ-aminopropyltriethoxysilane as an agent, γ-
It is preferable to use an alkoxysilane compound such as glycidoxypropyltrimethoxysilane and an epoxy resin or urethane resin as a binder.

The amount of glass fiber used is 10 to 150 per 100 parts of component (A).
Parts, preferably 15 to 100 parts, and when the amount is less than 10 parts, the mechanical strength is largely decreased, which is not preferable.
If it exceeds the area, the workability of extrusion molding, injection molding, etc. will be insufficient, and there will be restrictions from this aspect.

The copolymer composed of the α-olefin and the glycidyl ester of the α, β-unsaturated carboxylic acid used in the present invention is, for example, ethylene, propylene, 1-butene, 1-hexane, 1-octene, or two kinds thereof. The above is a copolymer of acrylic acid glycidyl ester, methacrylic acid glycidyl ester, cyclohexene-4-carboxylic acid glycidyl ester, or the like, or a copolymer of two or more thereof. The content of the glycidyl ester of α, β-unsaturated carboxylic acid in the copolymer is preferably 1.0 to 20%,
It is more preferably 3 to 15%. If the content is less than 1.0, not only is the effect of improving moisture resistance insufficient, but the compatibility of the copolymer with polyethylene terephthalate is poor,
The mechanical strength is liable to be lowered, and if it exceeds 20%, the fluidity of the composition tends to be remarkably lowered.

The copolymer is used in an amount of 5 to 100 parts, preferably 7 to 60 parts, based on 100 parts of the component (A). If the amount is less than 5 parts, the effect of improving the moisture resistance is not sufficient, and if it exceeds 100 parts, the mechanical strength is significantly lowered, and the composition is contrary to the object of the present invention.

The composition of the present invention may contain additives commonly used in resin compositions, such as stabilizers, colorants, antistatic agents, flame retardants, processability improvers and nucleating agents.

The composition of the present invention can be produced by various known methods such as an extruder method.

The composition of the present invention thus produced is molded by, for example, a method such as extrusion molding or injection molding. The molded product has good heat resistance, impact resistance, moisture resistance, rigidity, appearance and the like. It has the feature. Therefore, auto parts,
It is preferably used in fields such as electric tool housings and electric appliance parts.

Next, the composition of the present invention will be described more specifically based on Examples and Comparative Examples.

Comparative Examples 1 to 3 Modified polyethylene terephthalate-1 (phenol / 1,1,2) obtained by melt-kneading 35 parts of polyethylene glycol having an average molecular weight of about 600 and 65 parts of polyethylene terephthalate oligomer under reduced pressure to copolymerize polyethylene glycol. , 2
-Tetrachloroethane = 1: 1 (weight ratio) in a mixed solvent, 0.5
% Concentration, the intrinsic viscosity measured at 25 ° C is 0.80), then
It was dried until the water content was 0.01% or less to obtain the component (A).

Separately, ethylene / glycidyl methacrylate =
9/1 (weight ratio) ethylene-glycidyl methacrylate random copolymer (flow rate 3.0 g / 10 min (ASTM D-
1238, E), hereinafter referred to as EGMA-1 (component (C)) was produced.

Obtained modified polyethylene terephthalate-1 and EG
MA-1 was added in the proportion shown in Table 1, and tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-
Hydroxyphenyl) propionate] methane 0.2 parts,
0.2 parts tris (2,4-di-t-butylphenyl) phosphite and pentaerythritol-tetrakis (β
-Lauryl thiopropionate) (0.2 part) was added and mixed, and then melt-kneaded using a twin-screw extruder PCM-45 manufactured by Ikegai Tekko KK to obtain a pelletized resin composition. At this time, 30 parts of glass fibers (Glaslon 03MJ-486A, manufactured by Asahi Fiber Co., Ltd.) were added in the middle of the twin-screw extruder.

The temperature conditions during extrusion are from the hopper side to the die side.
A temperature gradient of 0 ° C to 270 ° C was applied. For other conditions, general conditions were selected so as to stably extrude.

The pelletized resin composition obtained was dried to a water content of 0.02% or less, and an injection molding machine (manufactured by Toshiba Machine Co., Ltd. IS-
75E) was used to fabricate and evaluate test pieces for evaluating the properties shown in Table 1. The results are shown in Table 1.

The tensile strength is ASTM D-638 method, and the falling weight strength is load 500.
g, tip R3 / 8 inch, half fracture height in case of sample thickness 3mm, required for HDT of thin molded product to exceed 160 ° C. Mold temperature is described in ASTM D648-56 Note-1. 1/16 in the way
Inch thin-wall molded product test pieces were prepared and their HDT (18.6 kg /
The mold temperature required for the cm ² ) to exceed 160 ° C is measured, and the humidity resistance is 90 ° C and the test piece is placed in an atmosphere of 100% RH for 72 hours, then the tensile strength is measured and the initial strength is maintained. It was determined by calculating the rate.

Comparative Example 4 A test piece was prepared and evaluated in the same manner as in Comparative Example 1 except that all EGMA-1 used in Comparative Example 1 was modified polyethylene terephthalate-1. The results are shown in Table 1.

Comparative Example 5 Modified polyethylene terephthalate-1 used in Comparative Example 4
A test piece was prepared and evaluated in the same manner as in Comparative Example 4 except that polyethylene terephthalate having an intrinsic viscosity of 0.62 was used. The results are shown in Table 1.

Comparative Example 6 Modified polyethylene terephthalate-1 used in Comparative Example 2
A test piece was prepared and evaluated in the same manner as in Comparative Example 2 except that polyethylene terephthalate having an intrinsic viscosity of 0.62 was used. The results are shown in Table 1.

Examples 1-2 Modified polyethylene terephthalate-1 used in Comparative Example 1
Instead of 40 parts of an ethylene oxide addition polymer of bisphenol A having an average molecular weight of about 1000 and 60 parts of polyethylene terephthalate, modified polyethylene terephthalate-2 (intrinsic viscosity 0.65) and ethylene / Glycidyl methacrylate = 95/5 (weight ratio) ethylene glycidyl methacrylate random copolymer (flow rate 3.0g / 10min (ASTM D-1238, E),
(Hereinafter referred to as EGMA-2) in the proportions shown in Table 2, the same amount of the same additive used in Comparative Example 1 was used, and glass fiber was added in the same manner as in Comparative Example 1 to form a pelletized resin composition. Then, a test piece was prepared and evaluated. The results are shown in Table 2.

Comparative Example 7 A test piece was prepared and evaluated in the same manner as in Example 1 except that all the EGMA-2 used in Example 1 was modified polyethylene terephthalate-2. The results are shown in Table 2.

Comparative Example 8 A test piece was prepared and evaluated in the same manner as in Example 1 except that EGMA-2 used in Example 1 was changed to Epicoat 828 (produced by Yuka Shell Epoxy Co., Ltd.). The results are shown in Table 2.

[Effects of the Invention] Molded articles produced from the composition of the present invention have mechanical strength,
It has an excellent balance of impact resistance, moisture resistance, workability, etc., and eliminates the drawbacks of conventional molded articles made of polyethylene terephthalate resin.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification number Office reference number FI technical display location C08L 63/00 67/02 LPC LPF 71/00 LPZ

Claims (1)

[Claims] 1. A general formula (I): (In the formula, R ¹ represents a C _{2 to} C ₄ divalent hydrocarbon group, X represents a divalent bonding group or a direct bond, and m and n are each 5
Polyethylene terephthalate 10 to 5 to 90% by weight of a polyether having a main part represented by
To 95% by weight, 100 parts by weight of a copolymer component, (B) 10 to 150 parts by weight of glass fiber, and (C) a copolymer of α-olefin and glycidyl ester of α, β-unsaturated carboxylic acid. A resin composition containing 5 to 100 parts by weight.