JPS61126166A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide the titled compsn. having excellent resistance to chemicals and low-temperature impact, consisting of an arom. polycarbonate resin, a polytetramethylene terephthalate resin and a acrylate ester core/shell graft copolymer. CONSTITUTION:A vinyl compd. and a crosslinking agent are graft-copolymerized onto a core composed of a crosslinked rubber copolymer obtd. by copolymerizing a 2-12C alkyl acrylate and a polyfunctional polymerizable monomer contg. conjugated diene type double bond in the presence of a crosslinking agent, to form a shell, thus obtaining aan acrylate ester core/shell graft copolymer (C). 15-55pts.wt.arom. polycarbonate resin (A), 44-84pts.wt. mixture (B) of 50-100wt% polytetramethylene terephthalate resin having an intrinsic viscosity of 0.6 or above and 50-0wt% polyethylene terephthalate resin and 1-25pts.wt. component C are blended together.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention provides a heat-resistant material that exhibits various mechanical properties, particularly excellent impact resistance at low temperatures, good chemical resistance, moldability, and appearance. It relates to plastic resin compositions, and provides molding materials suitable for large parts such as automobile bumpers and bodies.

[Conventional technology and its problems]

As is well known, aromatic polycarbonate resins are used as useful engineering plastics because they are tough, have excellent impact resistance, electrical properties, and good dimensional stability. However, the melt viscosity is high and the moldability is poor.
Its range of applications is limited because of its drawbacks, such as its impact resistance being thickness-dependent and its chemical resistance being susceptible to cracking when it comes into contact with aromatic solvents or gasoline. is the actual situation.

For example, in the automobile industry, there is a strong demand for resins that have impact resistance at low temperatures due to safety needs, and aromatic polycarbonate resins are attracting attention for this reason. Due to its high melt viscosity, it is difficult to fill molds for large molded products such as automobile parts, resulting in short molds and crepe patterns, making it difficult to obtain good molded products.

Therefore, if the molding temperature is raised to a level that makes filling easy, problems such as thermal decomposition occur, making it difficult to obtain a molded product with good appearance and stable physical properties. On the other hand, there is a method of improving molding processability by lowering the average molecular weight of the polycarbonate resin, but this has drawbacks such as reduced impact resistance and difficulty in releasing from the mold.

In order to improve these drawbacks, proposals have been made to blend various resins into aromatic polycarbonate resins. For example, Japanese Patent Publication No. 40-17663 discloses polyolefin, Japanese Patent Publication No. 40-24191 discloses ethylene-propylene copolymer, and Japanese Patent Publication No. 38-15225 discloses polyolefin.
It is taught to mix S resin, MBS resin in Japanese Patent Publication No. 39-71, and MAS resin in Japanese Patent Publication No. 4B-29308, and these have improved moldability and impact resistance. There are various defects such as a decrease in the heat deformation temperature of the material, a surface peeling phenomenon due to poor compatibility, and a weakness in the weld portion, so improvements cannot necessarily be said to be sufficient for practical use. Japanese Patent Publication No. 36-14035 proposes blending polyethylene terephthalate resin with aromatic polycarbonate resin to improve solvent resistance, but the compatibility is poor and the impact resistance is poor. Also, JP-A-48-541
No. 50 proposes adding a polytetramethylene terephthalate resin to improve surface hardness and chemical resistance, but this results in extremely low impact resistance. In addition, the special public
Publication No. 20434 proposes a ternary composition in which an aromatic polycarbonate resin is blended with an aromatic saturated polyester resin and a polyolefin, and although improvements in moldability, impact resistance, and chemical resistance are recognized. However, the effect of improving impact resistance at low temperatures is small, and there are various defects such as surface peeling caused by poor compatibility and weak weld parts, and improvements are not necessarily sufficient to meet recent market demands. I can't say that.

[Means for solving problems]

The present invention improves the chemical resistance and impact resistance at low temperatures of aromatic polycarbonate resin by blending aromatic polycarbonate resin, polytetramethylene terephthalate, and a specific acrylic acid ester core-shell graft copolymer. The present invention has been completed by discovering a thermoplastic resin composition that improves the thickness dependence of impact value and moldability, and also has a well-balanced variety of properties such as mechanical strength, heat resistance, and appearance.

That is, the present invention comprises 44 to 84 parts by weight of a mixture of (A) 15 to 55 parts by weight of an aromatic polycarbonate resin, CB) 50 to 100 parts by weight of a polytetramethylene terephthalate resin, and 0 to 50 parts by weight of a polyethylene terephthalate resin, and ( C) A polycarbonate resin-based thermoplastic resin composition with excellent impact resistance at low temperatures, characterized by containing 1 to 25 parts by weight of an acrylic acid ester-based core-shell graft copolymer.

The present invention will be explained in detail below.

The aromatic polycarbonate resin (8) of the present invention is an optionally branched thermoplastic aromatic polycarbonate resin produced by reacting an aromatic dihydroxy compound or a small amount of a polyhydroxy compound with a diester of phosgene or carbonic acid. It is a combination. Examples of aromatic dihydroxy compounds are 2,2-bis(4-hydroxyphenyl)propane (=bisphenol A), tetramethylbisphenol A, tetrabromobisphenol A, bis(
4-hydroxyphenyl) -P-diisopropylbenzene, hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, etc., with bisphenol A being particularly preferred. In addition, to obtain a branched aromatic polycarbonate resin, phloroglucin, 4,6-dimethyl-2.4.6-)li(4-hydroxyphenyl)hebutene-2,4,6-dimethyl-2.4.6- bird (
4-Hydroxyphenyl)hebutane, 2.6-dimethyl-2.4.6-)li(4-hydroxyphenyl)
Hebutene = 3.4.6-dimethyl-2.4.6-tri
(4-hydroxyphenyl)hebutane, 1,3.5-
tri(4-hydroxyphenyl)benzene, 1,1.
Polyhydroxy compounds such as 1-tri(4-hydroxyphenyl)ethane and 3,3-bis(4-hydroxyphenyl)ethane,
-hydroxyaryl)oxindole (=isatin bisphenol), 5-chloroisatin bisphenol, 5,7-cycloisatin bisphenol, 5-bromoisatin bisphenol, etc. as part of the dihydroxy compound, e.g. ~2 mol% is substituted with polyhydroxy compound. In addition, monovalent aromatic hydroxy compounds suitable for adjusting the molecular weight include tri- and p-methylphenol, m- and p-propylphenol, p-bromophenol, p-tert-butylphenol and p-long-chain alkyl-substituted phenol. etc. are preferable. A typical aromatic polycarbonate resin is bis(
Aromatic polycarbonate copolymers obtained by using a combination of two or more aromatic dihydroxy compounds, including aromatic polycarbonate resins containing 4-hydroxyphenyl)alkane compounds, particularly bisphenol A, as the main raw material;
Branched aromatic polycarbonate resins obtained by using a small amount of trivalent phenolic compounds can also be mentioned.

Aromatic polycarbonate resins may be used as a mixture of two or more types.

Polytetramethylene ethylene terephthalate 1 used in the present invention
-(B) is a polymer obtained by reacting an aromatic dicarboxylic acid or its diester with a glycol whose main glycol component is tetramethylene glycol by a known method. Specifically, terephthalic acid or dimethyl terephthalate is used as the main component of the aromatic dicarboxylic acid, and this is combined with isophthalic acid, 2,6-naphthalene dicarboxylic acid, 2,7-naphthalene dicarboxylic acid, and 1.5-naphthalene dicarboxylic acid. , 4.4"-diphenyldicarboxylic acid, 4,4°-diphenoxyethanedicarboxylic acid, ρ-oxybenzoic acid, cehatic acid, adipic acid, etc. are used together as appropriate, and an aromatic carboxylic acid, and tetramethylene glycol are mainly used. , 30 mol% or less of ethylene glycol or other glycols such as ethylene oxide, trimethylene glycol, hexamethylene glycol, decamethylene glycol, cyclohexane dimetatool,
Preferably, it is formed by polycondensing glycol in an amount of 20 mol% or less, and may be polytetramethylene terephthalate alone or a mixture thereof with polyethylene terephthalate as a subcomponent. The polytetramethylene terephthalate resin used in the present invention is
Intrinsic viscosity [η
] is preferably 0.6 or more, and if it is less than 0.6, the improvement in impact strength and chemical resistance will be insufficient.

Furthermore, the acrylic acid ester-based core-shell graft copolymer (C) is a polyfunctional polymer having a conjugated diene type double bond represented by an alkyl ester of acrylic acid having 2 to 12 carbon atoms in the alkyl group and butadiene. A core consisting of a crosslinked rubber copolymer obtained by copolymerizing a rubber monomer with a small amount of crosslinking agent as an essential component, and one or more vinyl compounds as an essential component and a small amount of crosslinking. Refers to a core-shell graft copolymer formed by adding an agent and graft-polymerizing it to form a shell consisting of a resin layer, and refers to a crosslinked rubber copolymer of the core-shell graft copolymer (=
The weight of the core is 50 to 80% by weight, and the weight of the shell is 50 to 20% by weight.

As the acrylic acid alkyl ester having an alkyl group having 2 to 12 carbon atoms used to form the crosslinked rubber copolymer core, n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferred. Further, as the conjugated diene, in addition to the above-mentioned butadiene, l-methyl-2-vinyl-4,6-hebutadien-1-ol, 7-methyl-3
-methylene-1,6-octadiene, 1,3,7-octatriene, and the like.

Furthermore, the crosslinking agent used should be selected from one that copolymerizes well with the mixed monomers in each polymerization step, such as aromatic polyfunctional vinyl compounds such as divinylbenzene and divinyltoluene, and ethylene glycol dimethacrylate. ,
Dimethacrylates such as diethylene glycol dimethacrylate and triethylene glycol dimethacrylate, and diacrylates such as ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, and 1,3-butanediol diacrylate are preferred.

In addition, when copolymerizing an alkyl ester of acrylic acid with a polyfunctional polymerizable monomer having a conjugated diene type double bond, an aromatic vinyl compound such as styrene or methyl methacrylate may be used as desired. methacrylic acid ester, vinyl cyanide compound represented by acrylonitrile, vinyl ether compound represented by methyl vinyl ether, vinyl halide compound represented by vinyl chloride, and vinyl ester compound represented by vinyl acetate. A monofunctional polymerizable monomer, particularly a methacrylic acid ester represented by methyl methacrylate, can also be used as a part of an acrylic alkyl ester having an alkyl group having 2 to 12 carbon atoms.

Next, the vinyl compounds used for graft polymerization to the crosslinked rubber copolymer (core) include methacrylic acid esters represented by methyl methacrylate, aromatic vinyl compounds represented by styrene, and acrylonitrile. Examples include polymerizable monomers selected from the group consisting of vinyl cyanide compounds and halogenated vinyl compounds represented by vinyl chloride, and two or more of these may be used in combination. Furthermore, the above-mentioned crosslinking agent may be used in combination during graft polymerization.

A typical production example of such an acrylic ester-based core-shell graft copolymer includes 70 to 95 parts by weight of an acrylic alkyl ester having an alkyl group of 2 to 12 carbon atoms, 30 to 5 parts by weight of butadiene, and Crosslinking agent 0.0
Crosslinked rubber copolymer obtained by emulsion polymerization of mixed monomers consisting of 1 to 3 parts by weight, especially 0.05 to 1.5 parts by weight 5
Contains 0 to 75 parts by weight, and has an average particle size of 0.05 to 0.1
- Average particle diameter obtained by adding a flocculant, for example, a mineral acid such as hydrochloric acid or sulfuric acid, to latex in the range of 0612 to
A monomer component consisting of 10-90% by weight of styrene and 90-10% by weight of superimposed methacrylate containing 0.01-2.0 parts by weight of a crosslinking agent in 0.3-weight aggregated particles 50-2
First, 5 parts by weight was divided into a mixture of methyl methacrylate containing styrene as a main component containing a cross-linking agent and methyl methacrylate containing a cross-linking agent, and the former was added and polymerized to the aggregated rubber latex described in 11j, and then the latter was added and polymerized. Method: 40 to 95 parts by weight of an acrylic acid alkyl ester having an alkyl group having 2 to 12 carbon atoms, 40 to 5 parts by weight of butadiene, 80 to 30 parts by weight of methyl methacrylate, and 0.01 to 3 parts by weight of a crosslinking agent, especially A crosslinked rubber copolymer obtained by emulsion polymerization of mixed monomers consisting of 0.05 to 1.5 parts by weight. A flocculant, for example, a mineral acid such as hydrochloric acid or sulfuric acid, is added to a latex containing 50 to 80 parts by weight. Agglomerated particles having an average particle diameter of 0.12 to 0.5 mm are first mixed with 10 to 50% by weight of acrylonitrile and 90 to 50% by weight of styrene or methyl methacrylate, and 0.5% of a crosslinking agent is added.
After adding and polymerizing 45 to 10 parts by weight of a monomer containing 01 to 3.0 parts by weight, a methacrylic acid argyl ester monomer having 1 to 4 carbon atoms in an alkyl group containing 0.01 to 3.0 parts by weight of a crosslinking agent is added. Examples include a method of further adding and polymerizing 5 to 25 parts by weight of the polymer.

These graft polymerizations may be carried out in one stage, or may be carried out in multiple stages by changing the graft component monomer in multiple stages. Although the preferred manufacturing method is shown as an emulsion type method,
It is a matter of course that the desired acrylic acid ester core-shell graft copolymer can be produced by other known polymerization methods without being limited thereto.

Such an acrylic ester based core-shell graft copolymer is available from Kureha Chemical Industry Co., Ltd. under the trade name rHIA-15.
A resin commercially available as JrHIA-28J or [HIA-30J is preferably used.

The above components (A), (B) and (C) of the present invention are aromatic polycarbonate resin (A) 15 to 55 parts by weight, polytetramethylene terephthalate resin 50 to 80 parts by weight, and polyethylene terephthalate resin 0 to 50 parts by weight. (B) 44 to 84 parts by weight and acrylic acid ester core-shell graft copolymer (C) 1 to 2
5 parts by weight is blended.

If the aromatic polycarbonate resin (c) is less than 15 parts by weight, the heat resistance will not reach the level required for engineering plastics, and the dimensional stability will be poor, and if it exceeds 55 parts by weight, the moldability will not improve. It becomes insufficient. If the polytetramethylene terephthalate resin (B) is less than 44 parts by weight, the improvement in chemical resistance will be insufficient, and if it exceeds 84 parts by weight, dimensional stability will be poor and impact resistance will decrease. Furthermore, if the acrylic acid ester based core-shell graft copolymer (C) is less than 1 part by weight, the impact resistance will not be improved, and if it exceeds 25% by weight, it will cause poor heat resistance. Therefore, by blending in the above-mentioned specific proportions, the resin composition of the present invention exhibits balanced physical properties.

The thermoplastic resin composition of the present invention as described above may contain various additives such as stabilizers, pigments, dyes, flame retardants, and lubricants, reinforcing materials such as inorganic or organic fiber substances, glass beads, etc., as desired. Various fillers may be blended, and other resin components may also be blended within a range that does not impair the characteristics of the present invention. For example, polycarbonate oligomers from bisphenol A or tetrabromobisphenol A can be used to improve moldability, flame retardancy, and surface properties, and heat-resistant polyesters such as polyester carbonates and polyarylates (e.g., trade names: U Polymer, Unitika N) For improving heat resistance, it is possible to incorporate

In preparing the thermoplastic resin composition of the present invention,
Any conventionally known method may be used, and methods of kneading using an extruder, Banbury mixer, rolls, etc. may be selected as appropriate.

〔Example〕

Examples and comparative examples will be described below, and "parts" are based on weight unless otherwise specified.

Examples 1 to 5 and Comparative Examples 1 to 5 Aromatic polycarbonate made from bisphenol A (manufactured by Mitsubishi Gas Chemical, trade name Newpiron S-2000)
, molecular weight 25,000), polytetramethylene terephthalate (manufactured by Polyplastic ■, product name: Duranesox 2002), polyethylene terephthalate (manufactured by Nippon Unipet ■, product name: Unipet RT-580)
, and acrylic acid ester-based core-shell graft copolymer (manufactured by Kureha Chemical Co., Ltd., trade name, A: former A-15, B
:HI8-28) in the ratio shown in Table 1 in a blender, mixed for 30 minutes, and then melted and extruded into pellets using a vented extruder (40mm diameter, L/D-25, cylinder temperature 230°C). And so.

This pellet was dried in a hot air dryer at 120° C. for 5 hours or more, and a test piece for measuring physical properties was molded using an injection molding machine, and the physical properties were tested.

The results are shown in Table 1.

For comparison, aromatic polycarbonate resin alone (comparative example -
1), Composition of aromatic polycarbonate resin and polytetramethylene terephthalate (Comparative example-2), Comparative example-
CHINOKU Comparative Example-3) Adding MBS resin (manufactured by Japan Synthetic Rubber ■, product name: JSRMBS 67) to the composition of 2)
, MAS resin (Mitsubishi Rayon■
5EBS resin (Comparative Example-4) and Comparative Example-2 (Comparative Example-2).
Table 1 also shows the results of the same procedure as above for the product (Comparative Example-5) to which Kraton G1651 (manufactured by Shell Kagaku@, trade name: Kraton G1651) was added.

[Operation and effect of the invention]

As explained above in the detailed explanation, the composition of the present invention includes:
Chemical resistance, impact resistance at low temperatures and thickness dependence of impact value,
In addition to improving moldability, it has a good balance of various properties such as mechanical strength, heat resistance, and appearance, and can provide a molding material suitable for large parts such as automobile bumpers and bodies. That is clear.

Claims (1)

[Scope of Claims] (A) 15 to 55 parts by weight of aromatic polycarbonate resin, (B) 50 to 1 part by weight of polytetramethylene terephthalate resin
00% by weight and polyethylene terephthalate resin 0-50
A polycarbonate resin system having excellent impact resistance at low temperatures, characterized by containing 44 to 84 parts by weight of a mixture with % by weight and 1 to 25 parts by weight of (C) an acrylic acid ester based core-shell graft copolymer. thermoplastic resin composition.