JPH01163249A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To obtain the title composition significantly outstanding in chemical and impact resistances, by incorporating a specified amount of an aromatic polyester in a rubber-modified styrene-based thermoplastic resin copolymerized with epoxy group-contg. vinyl monomer. CONSTITUTION:The objective composition can be obtained by incorporating (A) 51-90wt.% of a rubber-modified styrene-based thermoplastic resin (e.g., ABS resin) containing 0.05-3wt.% of an epoxy group-contg. vinyl monomer (e.g., glycidyl methacrylate) with (B) 10-49wt.% of an aromatic polyester (e.g., polybutyleneterephthalate).

Description

Detailed Description of the Invention a. Industrial Application Field The present invention relates to a thermoplastic resin composition having excellent chemical resistance and impact resistance, and in particular a thermoplastic resin composition containing an aromatic polyester and copolymerized epoxy groups. The present invention relates to a thermoplastic resin composition containing a specific amount of vinyl monomer and having excellent chemical resistance and impact resistance.

b. Conventional technology Traditionally, aromatic vinyl compound thermoplastic resins, especially rubber-modified styrene thermoplastic resins, have been used in various fields such as automobile parts and electrical products because they are lightweight and have excellent moldability. ing.

Problems to be Solved by the C0 Invention However, the rubber-modified styrenic thermoplastic resin is not necessarily stable against organic solvents, etc., and cannot be used particularly in situations where stress is present or the resin is kept in a deformed state. In many cases, chemical resistance deteriorates significantly. This is a major obstacle to the use of rubber-modified styrene thermoplastic resins in a wider range of fields.

Particularly in automotive parts, if rubber-modified styrenic thermoplastic resin and polyvinyl chloride containing a plasticizer come into contact, or if brake fluid adheres to rubber-modified styrenic thermoplastic resin, It has been said that contact between plasticizer and brake fluid causes so-called environmental stress cracking, which has become a problem.

Therefore, as a means to solve these problems and improve chemical resistance, conventional methods of increasing the molecular weight of rubber-modified thermoplastic resins, vinyl cyan compounds, (
Although methods are known in which a monomer having a polar group such as meth)acrylic acid ester is introduced into a polymer, sufficient chemical resistance cannot yet be obtained by these methods.

Further, conventional rubber-modified styrene thermoplastic resins do not have sufficient impact resistance, and are subject to limitations in the field of their use.

Means for Solving the d9 Problem As a result of intensive research to solve the above problems, the present inventors have identified a rubber-modified styrenic thermoplastic resin copolymerized with a specific amount of epoxy group-containing vinyl monomer. The present invention was completed based on the discovery that a rubber-modified styrenic thermoplastic resin having extremely excellent chemical resistance and impact resistance can be obtained by blending a certain amount of aromatic polyester.

That is, the present invention comprises (A) 51 to 90% by weight of a rubber-modified styrenic thermoplastic resin, (B) 10% by weight of an aromatic polyester.
-49% by weight, and contains 0.05-3% by weight of an epoxy group-containing vinyl monomer copolymerized in the rubber-modified styrenic thermoplastic resin (A). A rubber-modified thermoplastic resin composition with excellent impact resistance.

Detailed Description of the e0 Invention The components used in the thermoplastic resin composition of the present invention will be described in detail below.

(A) Rubber-modified styrenic thermoplastic resin component The rubber-modified styrenic thermoplastic resin component used in the present invention is: ■Rubber-modified styrenic polymer or ■Rubber-modified styrenic polymer and styrenic polymer (rubber It is a mixture of a rubbery polymer and a specific styrenic polymer in order to obtain a high degree of impact resistance. A simple mechanical blending method may be used as the mixing method, but in order to obtain good compatibility, a so-called graft copolymerization method in which a styrene monomer or the like is graft copolymerized in the presence of a rubbery polymer is recommended. Those obtained by polymerization recipe are more preferable. It is also preferable to use a polymer obtained by a so-called graft-blend method, in which a rubber-modified styrenic polymer (graft polymer) obtained by this method is mixed with a styrenic polymer obtained by a separate method. In the case of (2), the method of incorporating a copolymerized epoxy group-containing vinyl monomer into these rubber-modified styrenic thermoplastic resin components is as follows: In the case of a mixture of It contains the body.

Examples of the rubbery polymer used include polybutadiene, styrene-butadiene copolymer, acrylic copolymer, ethylene/propylene copolymer, chlorinated polyethylene, polyurethane, etc.
Among them, it is preferable to use polybutadiene.

Examples of the styrene monomer include styrene, α-methylstyrene, bromostyrene, etc. Among these, it is optimal to use styrene and/or α-methylstyrene.

Further, examples of the epoxy group-containing vinyl monomer include glycidyl methacrylate, glycidyl acrylate, vinyl glycidyl ether, allyl glycidyl ether, glycidyl ether of hydroxyalkyl (meth)acrylate, glycidyl ether of polyalkylene glycol (meth)acrylate, Examples include glycidinol, itaconate, etc. Among these, it is preferable to use glycidyl methacrylate.

The epoxy group-containing vinyl monomer is contained in the rubber-modified styrenic thermoplastic resin in an amount of 0.05 to 3% by weight, preferably 0.
．． It is important to contain 1 to 2% by weight. If the content is less than 0.05% by weight, the compatibility with the aromatic polyester resin component decreases, resulting in a decrease in impact resistance, which is not preferable. Moreover, if the amount exceeds 3% by weight, impact resistance and moldability are reduced, which is not preferable. If the content is 0.1 to 0.8% by weight, the surface of the molded product will be beautiful and glossy, while if it exceeds 0.8% by weight and is 2% by weight, the surface of the molded product will be poor. is beautiful and has matte properties.

Furthermore, if necessary, it is possible to copolymerize with a comonomer other than the epoxy group-containing vinyl monomer that is copolymerizable with the entire styrene spinning wheel. Such comonomers include acrylonitrile, methacrylate, methyl methacrylate, N-phenylmaleimide, N
-Cyclohexylmaleimide, etc. are listed.

Generally, it is difficult to develop impact resistance with a styrene monomer alone, so it is preferable to copolymerize acrylonitrile. In this case, the preferred composition ratio of the aromatic vinyl compound and the vinyl cyanide compound is 60-90/10-40% by weight, more preferably 65-85/15-35% by weight.

When copolymerizing an epoxy group-containing vinyl monomer with a rubber-modified styrene thermoplastic resin, the base material to be present and graft copolymerized includes: 1) a rubbery polymer, 2) a graft layer of a graft polymer, or 3) Non-grafted styrene polymers may be mentioned, and among these, 2) or 3), particularly 3), are preferred.

Specifically, the rubber-modified styrenic thermoplastic resins obtained in this manner include conventional acrylonitrile-butadiene-styrene resin (ABS resin), acrylonitrile-ethylenepropylene-styrene resin (AES resin),
Methyl methacrylate-butadiene-styrene resin (MB
S resin), acrylonitrile-butadiene-methyl methacrylate-styrene resin, acrylonitrile-n-butyl acrylate-styrene resin (AAS resin), rubber modified polystyrene (high impact polystyrene: HIP
S) When producing a copolymer resin such as a heat-resistant rubber-modified styrenic resin using α-methylstyrene, styrene is added in the copolymer resin or in the styrenic polymer mixed with the copolymer resin. This copolymer is obtained by polymerizing a part of the monomer by replacing it with an epoxy group-containing vinyl monomer, and contains an epoxy group-containing vinyl monomer in the copolymer. Among these rubber-modified styrenic thermoplastic resins, the conventional ABS resin, particularly a heat-resistant ABS resin using α-methylstyrene, containing an epoxy group-containing vinyl monomer by copolymerization is most suitable.

Production method The above rubber-modified styrenic thermoplastic resin is produced by emulsion polymerization,
Manufactured by solution polymerization, bulk polymerization, suspension polymerization, etc. Further, as the polymerization initiator, molecular weight regulator, emulsifier, dispersant, solvent, etc. used in the polymerization, those normally used in these polymerization methods can be used as they are. A preferred method of the above production method is to use monomers and additional emulsifiers, monomers, and polymerization initiators in the presence of a rubbery polymer obtained by emulsion polymerization, generally at a polymerization temperature of 30 to 150°C. A graft copolymer obtained by graft copolymerization (including ungrafted styrenic polymer) for 1 to 15 hours under a polymerization pressure of 1.0 to 5.0 kg/crJ, and emulsion polymerization or This is a method of manufacturing by mixing with a styrenic polymer obtained by solution polymerization. The rubber content in the rubber-modified styrenic thermoplastic resin is preferably 5 to 40% by weight, more preferably 10 to 30Tl'! ff1%.

Further, the intrinsic viscosity ([η] unit dEX/g) of the methyl ethyl ketone soluble component of the rubber-modified styrene thermoplastic resin measured in methyl ethyl ketone at 30°C is preferably 0.2 to 1.2, more preferably 0°. 3~
A value of 1.0 is preferred.

The grafting ratio measured by solvent fractionation using acetone or the like of the rubber component of the graft polymer in the rubber-modified methylene thermoplastic resin is preferably 10 to 150%, more preferably 20 to 100%.

(B) Aromatic polyester Examples of the aromatic polyester include those obtained by condensing an aromatic dicarboxylic acid, ester, or an ester-forming derivative thereof with a diol by a known method.

Examples of the aromatic dicarboxylic acids include naphthalene-2
, 6-dicarboxylic acid, naphthalene dicarboxylic acid, terephthalic acid, isophthalic acid, p-hydroxybenzoic acid,
Included are adipic acid and sebacic acid and their ester-forming derivatives.

Examples of the diol include ethylene glycol, 1,
polymethylene glycols having 2 to 6 carbon atoms, such as 4-butanediol, 1,6-hexanediol;
or 1,4-cyclohexanediol, bisphenol A and ester-forming derivatives thereof.

Specific examples of aromatic polyesters obtained in this way include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), bisphenol A
Examples include ichphthalate, among which PBT is preferred.

The aromatic polyester preferably has an intrinsic viscosity of 0.4 to 2.0, more preferably 0.6 to 1.0 at 25°C in an isostatic mixed solvent of tetrachloroethane/phenol. 5.

The thermoplastic resin composition of the present invention is produced by mixing (A) a rubber-modified styrenic thermoplastic resin and (B) an aromatic polyester, and the specific method thereof is as follows. .

Composition The rubber-modified styrenic thermoplastic resin contains 5% in the composition.
The content is 1 to 90% by weight, preferably 55 to 90% by weight, and more preferably 60 to 85% by weight. If it is less than 51% by weight, the impact resistance of the resulting resin will decrease, which is not preferable. Moreover, if it exceeds 90% by weight, it is not preferable because chemical resistance decreases. The aromatic polyester is present in the composition in an amount of 10 to 49% by weight.
, preferably 10 to 45% by weight, more preferably 15% by weight
It is blended to contain up to 40% by weight. If it is less than 10% by weight, the chemical resistance of the resulting resin will decrease, which is not preferable. Moreover, if it exceeds 49% by weight, impact resistance will decrease, which is not preferable.

Mixing Rubber Modified styrenic thermoplastic resins and aromatic polyesters can be mixed using various mixing machines commonly used for mixing thermoplastic resins, such as Banbury mixers, Brabenders, plastomills, kneaders, and vented extruders. Although any apparatus and method may be used, preferred among these is a method using a vented extruder.

Furthermore, the form of each component resin before mixing is not particularly limited; for example, any form such as pellets, beads, powder, flakes, etc. can be mixed.
The mixing temperature needs to be higher than the melting point of the aromatic polyester to be mixed. On the other hand, since rubber-modified thermoplastic resins are thermally unstable at temperatures exceeding 300°C,
It is preferable that the mixing temperature is 230 to 300°C.

Note that it is convenient to produce the rubber-modified styrenic thermoplastic resin by the graft-blend method, since it is possible to simultaneously mix the graft polymer, styrenic polymer, and aromatic polyester.

The thermoplastic resin composition of the present invention produced by the method described above has extremely excellent chemical resistance and impact resistance, and has properties unique to rubber-modified styrenic thermoplastic resins, such as moldability and appearance of molded products. It also has excellent physical properties.

The thermoplastic resin composition of the present invention is characterized by blending an aromatic polyester with a rubber-modified stichine thermoplastic resin copolymerized with an epoxy group-containing vinyl monomer.

The action of aromatic polyester is thought to be as follows. In other words, rubber-modified styrenic thermoplastic resin is an amorphous resin, but when aromatic polyester, which is a crystalline resin, is blended with it, the dense crystal structure prevents chemicals from entering the resin. This is thought to improve chemical resistance.

Next, the action of the rubber-modified styrenic thermoplastic resin copolymerized with an epoxy group-containing vinyl monomer is considered to be as follows. First, when an aromatic polyester is blended with a rubber-modified styrenic thermoplastic resin that does not contain an epoxy group-containing vinyl monomer, chemical resistance improves, but impact resistance decreases. This is thought to be due to the miscibility of the two, but it has been found that when a specific amount of the epoxy group-containing vinyl monomer is copolymerized, the decrease in impact resistance can be suppressed.

Although the details are unknown, the epoxy groups present in the rubber-modified styrenic thermoplastic resin and the terminal hydroxyl groups of the aromatic polyester react during solvent kneading, and the resulting block (graft) body increases the miscibility of the two. I think there are.

Other Compounding Agents In addition to the above-mentioned essential ingredients, the thermoplastic resin composition of the present invention may optionally contain lubricants, antistatic agents, antioxidants, flame retardants, ultraviolet absorbers, photooxidants, It is possible to mix coloring agents, inorganic fillers such as glass fibers, or compounding agents and additives commonly used in this type of thermoplastic resin composition. will be further explained in detail with examples.

Parts by weight in this example are simply abbreviated as "parts."

Production Example 1 (Graft Copolymers G-1, G-2) A chemical solution with the batch composition shown in Table 1 was added to a 72 glass flask equipped with a stirring blade, and the air inside the flask was replaced with nitrogen. After that, the temperature inside the flask was raised to 40°C while controlling the jacket at 70°C. Then, 0.3 parts of sodium pyrophosphate, 0.35 parts of dextrose, 0.01 parts of ferrous sulfate, and 0.1 parts of cumene hydroperoxide dissolved in 10 parts of water were added to initiate the polymerization reaction. .

One hour after starting the reaction, the chemical solution of the incremental mixture shown in Table 1 was continuously added for 3 hours, and then the reaction was continued for another 1 hour.

To the obtained graft copolymer latex, 1.2,6-tert-butyl para-cresol was added as an anti-aging agent.
After adding 0 parts, sulfuric acid (2 parts per 100 parts of polymer) was added and coagulated at 90°C. And separate this,
Washed with water, dehydrated, and dried to obtain graft copolymers G-1 and G-2
I got it.

Margin Table-1 Production Example 1 (Graft Copolymer G1, G2) Table-1
Production Example 1 (Continued) 1) #0700 polybutadiene latex manufactured by Japan Synthetic Rubber ■ was used.

2) #0561 styrene-butadiene copolymer latex manufactured by Japan Synthetic Rubber ■ was used.

3) Measured using acetone.

Production Example 2 (Styrenic Polymers M-1 to M-10) The chemical solution shown in Table 2 was added to a 72mm glass flask equipped with a stirring blade, and after replacing the air inside with nitrogen, the jacket was The internal temperature was raised to 50°C while controlling the temperature at 50°C. Then, 0.3 parts of potassium persulfate dissolved in 4 parts of water and 1 part of water.
Add 0.1 part of sodium sulfite dissolved in
The copolymerization reaction was carried out for 3 hours.

Calcium chloride (2 parts per 100 parts of polymer) was added to the obtained styrenic polymer latex to give a
Solidified at 0°C. Then, separate this, wash it with water, dehydrate it,
After drying, styrenic polymers M-1 to M-9 shown in Table 2 were obtained.

Examples 1 to 13, Comparative Examples 1 to 6 Each thermoplastic resin component was mixed in the proportions shown in Tables 3 and 4 using a Henschel mixer. Furthermore, these mixtures were processed using a 30aIlrIi twin-screw vented extruder for 23
After granulation at a temperature of 0 to 270'C and drying at 90C, injection molding was performed at a temperature of 230 to 270C.
Various physical properties shown in 4 were measured.

Each thermoplastic resin component other than G-1, G-2 and M-1 to M-8 used in the formulation is shown below.

PBT resin... [η) = 1.0 manufactured by Polyplastics Co., Ltd. Product name: Dielanex XD-4 PET resin... [η) = 0.9 AES resin...
- AES resin consisting of 30 parts of EPDM containing ethylidene norbornene, 49 parts of styrene and 21 parts of acrylonitrile, grafting rate 50%, [η) = 0.5 AAS resin... From 30 parts of acrylic rubber, 49 parts of styrene and 21 parts of acrylonitrile AAS resin, graft ratio 40%, [η)=0.5 The physical properties were measured by the following method.

Izot impact strength: ASTM D256 (with 6 sequential thickness notches) Melt flow rate: ASTM D1238 (240
9C10kg) Load deflection temperature: ASTM D648 (Load 18
．． 6kg/c (no cyanyl) Gloss: ASTM D523 (3mm
Thickness) Constant strain solvent crack: Test piece (1/8" x 115'
A constant strain with a strain rate of 0.5% was applied to X5'), brake oil (abbreviated as BO) was applied to the bent portion, and the time until breakage was measured when the sample was left at 23°C. Also, under the condition of strain rate 1.0%, dioctyl phthalate) (DOP
Similar measurements were carried out using The longer the time, the better the chemical resistance. The target values were 5Hr or more for BO (several minutes with normal ABS) and 1011r or more (several hours with normal ABS) for DOP.

As shown in Examples 1 to 12, the compositions according to the present invention provide resin molded articles having extremely good impact resistance as shown by isot impact strength and chemical resistance as shown by constant strain solvent cracks. In addition, other physical properties such as fluidity as indicated by the melt flow rate, heat resistance as indicated by the deflection temperature under load, and appearance of the molded product as indicated by the degree of gloss are also good.

The rubber-modified styrenic thermoplastic resin composition of Comparative Example 1 was a general ABS resin and had poor chemical resistance.

In the composition of Comparative Example 2, the content of the epoxy group-containing vinyl monomer in the rubber-modified styrenic thermoplastic resin is below the range of the present invention, and the impact resistance is undesirable. Comparative example 3
In the composition, the content of the monomer exceeds the range of the present invention, and the impact resistance and melt flow rate are lowered, which is not preferable.

In Comparative Example 4.5, the blending ratio of (A) rubber-modified styrenic thermoplastic resin and (B) aromatic polyester is outside the range of the present invention. That is, it is not preferable that the content of component (A) exceeds 90% by weight and the content of component (B) is less than 10% by weight because the chemical resistance decreases (Comparative Example 4). Furthermore, if the content of component (A) is less than 50% by weight and the content of component (B) is greater than 50% by weight, the impact resistance will decrease, which is not preferable.

In Comparative Example 6, methacrylic acid was copolymerized instead of the epoxy group-containing vinyl monomer, and the impact resistance was insufficient.

h0 Effects of the invention In the rubber-modified styrenic thermoplastic resin composition of the invention, impact resistance is improved by containing a specific amount of an epoxy group-containing vinyl monomer as a copolymer in the rubber-modified styrenic thermoplastic resin. has been improved.

Since the thermoplastic resin composition of the present invention has excellent impact resistance and chemical resistance, it has great potential for application to new fields and is extremely useful industrially.

Claims (4)

[Claims] (1) (A) Rubber-modified styrenic thermoplastic resin 51-9
0% by weight, (B) aromatic polyester 10-49% by weight
The epoxy group-containing vinyl monomer copolymerized in the rubber-modified styrenic thermoplastic resin (A) is
A rubber-modified thermoplastic resin composition with excellent chemical resistance and impact resistance, characterized by containing 3% by weight. (2) The thermoplastic resin composition according to claim (1), wherein the rubber-modified styrenic thermoplastic resin (A) is an ABS resin copolymerized with an epoxy group-containing vinyl monomer. thing. (3) (B) Claim No. 1 characterized in that the aromatic polyester is polybutylene terephthalate.
Thermoplastic resin composition according to item ). (4) Claim No. 1, characterized in that the epoxy group-containing vinyl monomer is glycidyl methacrylate.
Thermoplastic resin composition according to item ).