JPH02302462A - Polyethylene terephthalate resin composition - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a polyethylene terephthalate resin composition with improved moldability that provides stable physical properties of molded products even in the presence of some moisture during molding. .

(Prior Art) Polyethylene terephthalate resin is widely used in various industrial fields as an engineering plastic with excellent mechanical and physical properties. However, since polyethylene terephthalate resin is a polyester resin with a high melting point, it undergoes hydrolysis in an extremely short period of time due to the small amount of water contained in the pellets or attached to the pellet surface during the molding process. It has disadvantages such as significantly deteriorating the mechanical and physical properties of the product and causing "burrs" to appear on the parting line of the product.

In order to solve the drawbacks of polyethylene terephthalate resin, many techniques have been reported for incorporating epoxy resins or phosphorus stabilizers, but no complete solution has been reached.

(Problem to be Solved by the Invention) Therefore, when molding polyethylene terephthalate resin, the pellets should be sufficiently dried before molding, the moisture content should be 100 to 200 ppm or less, and the pellets should be fed to the molding machine as quickly as possible. It is necessary to heat and melt it in time to finish the operation. Due to such troublesome management of pellet moisture and molding conditions, the market expansion of polyethylene terephthalate resin has been slow, even though it has superior mechanical and physical properties compared to polybutylene terephthalate resin. is the current situation.

As a result of intensive studies to solve the problems of these polyethylene terephthalate resin compositions, the present inventors found that
We have arrived at the present invention.

(Means for Solving the Problem) The present inventor has discovered that when a certain epoxy resin and a polystyrene resin are combined with a polyethylene terephthalate resin within a certain range, extremely stable moldability can be achieved even when water is contained. I found out that it shows.

That is, the present invention is a polyethylene terephthalate resin composition comprising the following components and composition ratios.

(A) 100 parts by weight of polyethylene terephthalate, (B) 1 to 15 parts by weight of a bisphenol-type epoxy resin with an epoxy equivalent of 1000 or less, (C) 1 to 15 parts by weight of a bisphenol-type epoxy resin containing 3 or more epoxy groups in one molecule and an epoxy equivalent of 350 to 2500. Epoxy resin 1-1
5 parts by weight, (D) 5 to 50 parts by weight of polystyrene resin, and (E)
Glass fiber 5-150 parts by weight.

Component (A): As the polyethylene terephthalate resin of component (A) used in the present invention, terephthalic acid or its ester-forming derivative is used as the acid component, and ethylene glycol or its ester-forming derivative is used as the glycol component. Refers to a polycondensed polymer, in which case it may contain up to 20 mol% of other dicarboxylic acids, glycols, or ester-forming derivatives thereof as the acid component and glycol component, respectively. Copolymerization components include, for example, isophthalic acid, naphthalene-2,6-dicarboxylic acid, dicarboxylic acids such as adipic acid, nitrimethylene glycol, tetramethylene glycol, neopentyl glycol, hexamethylene glycol, diethylene glycol, cyclohexanediol, 1.4- bis(oxyethoxy)benzene,
Examples include glycols such as bisphenol A, polyethylene glycol, and polypropylene glycol, and ester-forming derivatives thereof.

The intrinsic viscosity of the polyethylene terephthalate resin used in the present invention is 0 when measured at 23°C in a solution using a 1:1 weight ratio mixture of phenol and tetrachloroethane as the solvent.
．． When using a polyethylene terephthalate resin with an intrinsic viscosity of less than 0.4 dl/g, it is preferably in the range of 4 to 1.2 dl/g, especially 0.5 to 0.8 dl/g, to prevent "burr" from molding. Not only is the improvement effect small, but the strength of the obtained molded product is also low and impractical;
．． 2d! When using polyethylene terephthalate with an intrinsic viscosity of more than /g, the fluidity of the composition is extremely poor;
This is not preferable because the resulting molded product loses its glossy appearance.

Component (B): The epoxy equivalent of the bisphenol type epoxy resin which is the component (B) used in the present invention is suitably 1000 or less. For example, a bisphenol A type epoxy resin obtained by reacting bisphenol A and epichlorohydrin is suitable. It is.

Component (C): The epoxy resin which is component (C) conveniently used in the present invention is an epoxy resin having three or more epoxy groups in one molecule and having an epoxy equivalent of 350 to 2,5006. For example,
Styrene-glycidyl (meth)acrylate copolymer,
Styrene-glycidyl (meth)acrylate-methyl (
meth)acrylate terpolymer, styrene-glycidyl(meth)acrylate-methyl(meth)acrylate-acrylonitrile quaternary copolymer, etc., styrene, glycidyl(meth)acrylate, acrylic ester, acrylonitrile, vinyl acetate, etc. Examples include polymers obtained by radical copolymerization of various vinyl compounds, ethylene-vinyl acetate-glycidyl (meth)acrylate ternary copolymers, and novolak-type epoxy resins obtained from novolac resins and epichlorohydrin. Among these epoxy resins, di- to quaternary copolymers containing styrene and glycidyl (meth)acrylate are preferred.

Component (D): The polystyrene resin that is component (D) used in the present invention includes, in addition to ordinary styrene resins and high-impact polystyrene resins, acrylonitrile-styrene copolymers with a styrene content of 50 mol% or more, acrylonitrile -Styrene-butadiene copolymers are also included. Among these, high impact polystyrene resins are particularly preferred.

Component (E): The glass fiber used as component (E) in the present invention is not particularly limited as long as it is generally used for reinforcing resins. For example, it may be of long fiber type (roving) or short fiber type ( Chopped strands) can be selected and used.

Further, the glass fibers may be treated with a sizing agent (eg, polyvinyl acetate, polyester, etc.), a coupling agent (eg, silane compound, borane compound, etc.), or other surface treatment agent.

Blending ratio: The blending amount of the bisphenol type epoxy resin (B) is 1 to 15 parts by weight, preferably 2 to 12 parts by weight, and more preferably 3 to 10 parts by weight per 100 parts by weight of the polyethylene terephthalate resin (A). be. If the amount is less than 1 part by weight, the effect of the present invention will be small, and if it is more than 15 parts by weight, "burrs" will be more likely to occur and the mechanical strength will also be reduced.

Epoxy resin having three or more epoxy groups in one molecule (
The blending amount of C) is polyethylene terephthalate resin (A
) 1 to 15 parts by weight, preferably 2 parts by weight per 100 parts by weight
~12 parts by weight, more preferably 3 to 10 parts by weight.

If it is less than 1 part by weight, the effect of the present invention is small (and if it is more than 15 parts by weight, the fluidity of the composition is extremely poor and it is not practical.

It has also been found that when the blending ratio of the component (B) and component (C) satisfies the following formula, good results can be obtained in the properties of the resin composition.

The blending amount of polystyrene resin (D) is 5 to 50 parts by weight per 100 parts by weight of polyethylene terephthalate resin (A).
Parts by weight, preferably 7 to 40 parts by weight, more preferably 8 parts by weight
~30 parts by weight. If the amount is less than 5 parts by weight, the effect of the present invention will be small, and if it is more than 50 parts by weight, the heat resistance and mechanical strength will be significantly reduced.

The blending amount of the glass fiber (E) is 5 to 150 parts by weight, preferably 10 to 130 parts by weight, based on 100 parts by weight of the polyethylene terephthalate resin (A). If it is less than 5 parts by weight, the reinforcing effect by glass fiber is insufficient, and
If the amount exceeds 150 parts by weight, the fluidity and appearance of the composition will deteriorate significantly.

Mixing/kneading: The composition of the present invention is prepared using a conventional mixer/mixer. That is, after putting each component into a blender, ribbon mixer, tumbler, etc. and mixing them uniformly, -
The mixture is melt-kneaded using a conventional extruder such as a screw or twin-screw extruder, cooled, and then cut into pellets.

At this time, some of the glass fibers and other components may be added midway through the extruder, or some of the components may be mixed and mixed in advance, and then the remaining components may be added and extruded.

The composition of the present invention may contain flame retardants (for example, brominated bisphenol ale, brominated epoxy resin, brominated polystyrene resin, brominated polycarbonate resin, triphenyl phosphate, phosphonic acid) to the extent that the object of the present invention is not impaired. amide, red phosphorus, etc.), flame retardant aids (e.g., antimony trioxide, sodium antimonate, etc.), inorganic fillers (e.g., calcium carbonate, silica, talc, mica,
Potassium silicate, potassium titanate, etc.), nucleating agents (e.g., sodium stearate, ethylene-sodium acrylate copolymer, etc.), stabilizers (e.g., phosphate esters, phosphite esters, etc.), antioxidants ( For example, hindered phenolic compounds), light stabilizers, colorants, foaming agents, lubricants,
A mold release agent, an antistatic agent, etc. may be added.

In addition, small amounts of other thermoplastic resins (e.g., polyethylene, polypropylene, polyamide resins, polycarbonate resins, polyphenylene ether resins, polyphenylene sulfide resins, etc.), thermosetting resins (e.g., phenolic resins, melamine resins, silicone resins, etc.), A soft thermoplastic resin (eg, ethylene-propylene terpolymer, ethylene-vinyl acetate copolymer, polyester elastomer, etc.) may be added.

The composition thus obtained can be easily molded by any method such as injection molding, extrusion molding, compression molding, or rotational molding.

(Example) Example 1 and Comparative Examples 1 to 7 Intrinsic viscosity of component (A) is 0.7 df! /g (phenol:tetrachloroethane 1:1 mixed solvent, measured at 23°C) of polyethylene terephthalate (PET), as component (B) Epicote 828 (manufactured by Yuka Shell Co., Ltd., epoxy equivalent 190), (C ) as a component Premer CPi"5 (manufactured by NOF Corporation, epoxy equivalent: 1000).

Dialex HT76 (manufactured by Mitsubishi Monsanto, high impact polystyrene, HIPS) as component (D)
As component (E), glass fiber T198H (manufactured by Nippon Electric Glass Co., Ltd.) was mixed in a 10β tumbler at the mixing ratio shown in Table 1, and then mixed at a cylinder temperature of 260°C using a vented l-screw extruder with a screw diameter of 40mmφ. Molten mixture was mixed, and pellets for molding were obtained by strand cutting. The moisture content of this pellet was changed to approximately 100.5 by changing the drying conditions.
After adjusting to 3 levels of 00 and 1500ppn+, 6
A molded test piece was obtained using an ounce injection molding machine (Nippon Steel N-100BII) with a cylinder temperature setting of 265°C, a mold temperature of 90°C, a cooling time of 20 seconds, and a total molding cycle of 35 seconds.

In addition, the injection pressure was 1100p for the same blended composition.
The optimum pressure was uniformly set so that "burrs" would not occur when molding p-moisture content pellets.

The occurrence of "burrs" was evaluated in the following four stages.

×: Observed all around the test piece.

Δ: Although the degree is small, it is observed all around.

○: Found only near the gate.

0: Not recognized.

Measurement of tensile strength and izot (non-notched) impact strength is as follows:
The results are shown in Table 1 in accordance with JIS K7113 and JIS 7110.

From Table 1, the composition of the example has component B) fclfD+
Compared to Comparative Examples 1 to 7 lacking at least one of
Even when molded in a water-containing state of 500 ppm, there was almost no decrease in mechanical strength, and the occurrence of "burrs" was significantly less.

Table 1 1100 42.9 5501400 35
x148G 1150 25 x 2100 5 45.0 5101650 44
x14901290 33 x 3100 6 45.4 5201580 50
x15801300 38 x 105175G 55 0 4100 10 47.1 5251400 3
8 x15701220 29 x 5100 5 5 47.6 5501680 50
x15701530 39 x 6100 5 10 49.3 5701550
50 Δ14901400 42 x 7100 6 10 49.7 5301790 5
3 Δ15601480 42
Only the blending ratio of the ingredients was changed. Mixing and mixing of raw materials, molding, and evaluation were carried out in the same manner as in Example 1.

The results are summarized in Table 2. It can be seen from Table 2 that the effect of the present invention is not observed when the amount of Epicote E828 or Blenmar CP15 is less than 1 part by weight based on PET. On the other hand, when E828 or CP15 was 15 parts by weight or more, the mechanical strength of the composition decreased or the melt viscosity increased significantly, making molding impossible. Further, when the ratio of E828/CP15 was 0.2 or less (Comparative Example 12), the melt flowability of the composition was extremely poor and molding was impossible.

On the other hand, in cases of 3 or more (Comparative Example 13), the effect of the present invention was smaller than in Examples 1-7.

Examples 8 to 1O and Comparative Examples 14 to 15 The same types of raw materials as in Example 1 were used, and only the blending ratio of CD+ and component (E) was changed. Mixing and mixing of raw materials, molding, and evaluation were carried out in the same manner as in Example 1. The results are summarized in Table 3. From the same table, if the amount of HT76 is less than 5 parts by weight, the effect of the present invention is not observed, and if it is more than 50 parts by weight, no decrease due to moisture in the pellets is observed, but the mechanical strength itself is significantly decreased and is not practical.

Table 3 (Example) 8 100 5 6 7 50.6 5
41 1830 63 09 100 5
6 20 56.1 495 1770
54 010 100 5
6 40 64.7 495
1710 49 014 100
5 6 3 48.9 499 17
80 60 x1510 1720 54
x15 100 5 6 60
73.3 489 1300 35 0 Examples 11 to 13 and Comparative Examples 16 to 17 The same raw materials as in Example 1 were used, and only the blending ratio of the El component was changed.

Mixing and mixing of raw materials, molding, and evaluation were carried out in the same manner as in Example 1. The results are summarized in Table 4. From the same table, when the amount of glass fiber blended is 5 parts by weight or less, the mechanical strength is low;
If it exceeds 50 parts by weight, the melt viscosity of the composition is so high that molding is impossible. In addition, in Comparative Example 17, the pellets were 1480p.
Molding was possible at the maximum injection pressure only when it contained pm of water.

Table 4 11100 5 6 10 9.114951000
41 012 100 5 6
10 21.4 520 1
280 50 015202100 73
Q 16 100 5 6
10 3.74 504
50 ro 24 @ 0 1520 500 20 Δ 93 Not moldable Example 14.15 and Comparative Example 18 The same experiment as in Example 1 was conducted using bisphenol A type epoxy resins having different epoxy equivalents as the component (B). The results were compared with Example 1 and summarized in Table 5. From the same table, the epoxy equivalent of bisphenol A epoxy resin is 1
000 or more, it can be seen that the effect of the present invention is no longer recognized.

Table 5 (Example) Bisphenol A type epoxy resin manufactured by Chuyuka Shell Co., Ltd. Example 16 and Comparative Example 19.20 An experiment similar to Example 1 was conducted using epoxy resins having different epoxy equivalents as the component (C).

The results were compared with Example 1 and summarized in Table 6. From the same table (C
) When the epoxy equivalent of the epoxy resin was 350 or less, the melt flowability of the composition was poor and molding was impossible. Also, 25
00 or more, the effect of the present invention was not observed.

Table 6 (Comparative example) Glycidyl methacrylate copolymer Examples 17 and 18 (manufactured by Nakanihon Yushi Co., Ltd.) Tufflex 710 (manufactured by Mitsubishi Monsando Co., Ltd., acrylonitrile-butadiene-styrene copolymer, ABS) as the styrenic resin as component (D) ), Sunrex 5
AN-A (manufactured by Mitsubishi Monsando, acrylonitrile)
An experiment similar to Example 1 was conducted using a styrene copolymer (AS). The results are summarized in Table 7 along with Comparative Example 5. From the table, it was confirmed that both resins exhibited the same effects as in Example 1.

Table 7 (Example) 17 Tufflex 710" 475
1750 60 01520
1710 54 △1
6 Sunrex 5AN-A” 502
1790 56 01520
1720 52 Δ (comparative example) 5 - 550 1680
50 x 1570 1530
39 xol Mitsubishi Monsando ABS
Resin°3 Mitsubishi Monsanto Company AS resin (effects of the invention) The polyethylene terephthalate resin composition of the present invention shows almost no deterioration during molding, even if a small amount of moisture is present during molding, as described above. It also has good flow characteristics and exhibits stable moldability. Therefore, the occurrence of flakes in molded products can be minimized, and molded products with less deterioration in mechanical and physical properties can be obtained. In addition, the strict moisture control such as prevention of immersion and strict control of molding conditions, which are required for conventional molding materials, can be greatly relaxed.

Claims (1)

[Claims] A polyethylene terephthalate resin composition comprising the following components and composition ratios (A) 100 parts by weight of polyethylene terephthalate, (B) 1 to 15 parts by weight of a bisphenol-type epoxy resin having an epoxy equivalent of 1000 or less, (C ) 1 to 15 parts by weight of an epoxy resin containing three or more epoxy groups in one molecule and having an epoxy equivalent of 350 to 2,500, (D) 5 to 50 parts by weight of a polystyrene resin, and (E) 5 to 5 parts by weight of glass fiber. 150 parts by weight.