JPS61120852A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To improve resistance to chemicals and impact, moldability, etc., by incorporating an arom. polycarbonate resin with ethylene/vinyl carboxylate/ alkyl (meth)acrylate copolymer in a specific wt. ratio. CONSTITUTION:70-99wt% arom. polycarbonate resin yielded by the reaction of an arom. dihydroxy compd. (e.g., bisphenol A) with phosgene or a carbonic acid diester and 30-1wt% ethylene/vinyl carboxylate/alkyl (meth)acrylate copolymer (e.g., ethylene/vinyl acetate/methyl acrylate copolymer) are mixed by means of melt-blend, etc. to yield the intended thermoplastic resin compsn. Stabilizers, pigments, retardants, reinforcers, fillers, and other resin components such as heat-resistance polyesters can be incorporated if necessary.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides various mechanical properties, especially,
The present invention relates to a thermoplastic resin composition that exhibits excellent impact resistance at low temperatures, good chemical resistance, and good moldability.

[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 for this reason, aromatic polycarbonate resins are attracting attention. However, polycarbonate resin has a high melt viscosity as described above, and is difficult to fill into 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 easier, problems such as thermal decomposition will 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 the moldability by lowering the average molecular weight of the polycarbonate resin, but this method has drawbacks such as a decrease in impact resistance and difficulty in releasing the resin from the mold.

In order to improve these drawbacks, proposals have been made to blend various resins into JAJ resin. For example, Japanese Patent Publication No. 40-17663 teaches blending polyolefins, and Japanese Patent Publication No. 40-24191 Koko U teaches blending an ethylene-propylene copolymer. %”−
Although improvements in chemical resistance and chemical resistance have been observed, the effect of improving impact resistance at low temperatures is small, and there are various defects such as the surface Mi + 'ilf phenomenon caused by poor compatibility and the weakness of the welt part. However, it cannot be said that the improvement is necessarily sufficient for practical purposes.

[Means for solving problems]

The present invention improves the moldability, chemical resistance, and i5j 'J resistance under low/packing conditions of aromatic polycarbonate resin by blending a new ethylene/vinyl carboxylic acid ester/alkyl (meth)acrylate copolymer. In addition to improving the dependence of impact strength on thickness, they discovered and completed a thermoplastic resin composition that has a good balance of various properties such as mechanical strength and heat resistance.

That is, the present invention comprises A, aromatic polycarbonate resin 70 to 99% by weight, B, ethylene/carboxylic acid vinyl ester/alkyl (meth)acrylate copolymer 1 to
This is a new thermoplastic resin composition containing 30% by weight and having excellent chemical resistance and impact resistance.

The present invention will be explained in detail below.

8. The aromatic polycarbonate resin of the present invention is an optionally branched thermoplastic aromatic polycarbonate polymer produced by reacting an aromatic dihydroquine compound or a small amount of a polyhydroxy compound with a diester of phosgene or carbonic acid. .

It is. An example of an aromatic dihydroxy compound is 2゜2-
Bis(4-hydroxyphenyl)propane (=bisphenol A), tetramethylbisphenol A, tetrabromobisphenol A, bis(4-hydroxyphenyl)-P-diisopropylbenzene, hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, etc. Among them, bisphenol A is particularly preferred. In addition, to obtain a branched aromatic polycarbonate resin, phloroglucin, 4,6-dimethyl-2,4,6-tri(
4-Hydroxyphenyl)hebutene-2,4,6-dimethyl-2.4.6-)li(4-hydroxyphenyl)hebutane, 2,6-dimethyl-2.4.6-tri(4-hydroxyphenyl) Hebutene-3,4,6-
Cymethyl-2.4.6-)li(4-hydroxyphenyl)hebutane, 1,3.5-tri(4-hydroxyphenyl)benzene, 1.1.1-)li(4-hydroxyphenyl)ethane, etc. and 3,3-bis(4-hydroxyaryl)oxindole (= isatin (bisphenol))
), 5-chloroisatin, 5.7-dichloroisatin,
A part of the dihydroxy compound, for example 0.1 to 2 mol%, of 5-bromoisatin etc. is replaced with a polyhydroxy compound. Furthermore, m-aromatic hydroxy compounds suitable for adjusting the molecular weight include m- and p-methylphenol, m- and p-propylphenol, p-bromophenol, p-tert-butylphenol and p-
Long-chain alkyl-substituted phenols and the like are preferred. Typical aromatic polycarbonate resins include polycarbonates whose main raw materials are bis(4-hydroxyphenyl)alkane compounds, especially bisphenols, and
Also included are polycarbonate copolymers obtained by using a combination of more than one type of aromatic dihydroxy compound, and branched polycarbonates obtained by using a small amount of a trivalent phenol compound. Aromatic polycarbonate resins may be used as a mixture of two or more types.

B, ethylene/carboxylic acid vinyl ester/alkyl (meth)acrylate copolymer used in the present invention is:
The main component is ethylene, and vinyl esters of carboxylic acids having 1 to 4 carbon atoms such as vinyl acetate and vinyl propionate, especially vinyl acetate and methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, etc. of acrylic acid or methacrylic acid having 1 to 8 carbon atoms
The amount of carboxylic acid vinyl ester component in this copolymer is in the range of 0.1 to 15 mol%, preferably 1 to 10 mol%. and the amount of alkyl (meth)acrylate is 0.1 to 15 mol%, preferably 1
-10 mol%.

The ethylene copolymer of the present invention has a density and a degree of 0.
It has a melt index (hereinafter abbreviated as MT) of 0.1 to 100 g/min, and is usually produced by a radical polymerization method under high pressure.

Here, the radical polymerization method under high pressure means a polymerization pressure of 500 to 4,000 kg/c+J, preferably 1,000 to 3,500 kg/cJ, and a reaction temperature of 50
~400°C, preferably 100~350"C,
It refers to a method in which the monomers are brought into contact and polymerized simultaneously or in stages in a tank-type or front-type reactor in the presence of a free radical catalyst, a chain transfer agent, and, if necessary, an auxiliary agent.

The free radical catalysts include customary initiators such as peroxides, hydroperoxides, azo compounds, amine oxide compounds, oxygen, and the like.

In addition, chain transfer agents include hydrogen, propylene, butene-1, C+"Cz. or higher saturated aliphatic hydrocarbons and halogen-substituted hydrocarbons, such as methane, ethane, propane, butane, n-hexane, n - hebutane,
cycloparaffins, chloroform and carbon tetrachloride,
01-c2° or more saturated aliphatic alcohol,
For example, tutanol, ethanol, propatool and isopropanol, 01-C2° or higher saturated aliphatic carbonyl compounds such as carbon dioxide, acetone and methyl ethyl ketone and aromatic compounds such as toluene, diethylbenzene and xylene. Examples include compounds.

The blending ratio of the components of the thermoplastic resin composition of the present invention explained above is: 8. Aromatic polycarbonate resin: 70 to 99% by weight, preferably 80 to 99% by weight, particularly 90 to 99% by weight
The copolymer B is in the range of 1 to 1% by weight.
30% by weight or 1 to 20% by weight, especially 1 to 1
The thermoplastic resin composition of the present invention is usually prepared by melt-mixing.

If the aromatic polycarbonate resin is less than 70 parts by weight, the heat resistance will not reach the level required for engineering plastics, and the dimensional stability will be poor. If the amount of the polymer component is less than 1 part by weight, no improvement in chemical resistance or impact resistance will be achieved, which is not preferable.

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 name: U Polymer, Unitika) 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〕

Hereinafter, it will be explained by examples and comparative examples, but "%"
, "parts" and "molecular weight" are based on weight unless otherwise specified.

Examples 1 and 2 and Comparative Examples 1 to 4 Aromatic polycarbonate made from bisphenol A (manufactured by Mitsubishi Gas Chemical, trade name Newpiron S-2000)
, molecular weight 25,000), ethylene/vinyl acetate/ethyl acrylate copolymer (A: vinyl acetate content 5%)
, ethyl acrylate content 10% by weight, MT=0.9 g
/10 minutes, d = 0.940, and B: vinyl acetate content 5% maximum, ethyl acrylate content 10% by weight, MI =
1.6 g/10 min, d = 0.940> was used at the ratio shown in Table 1, and vented extrusion IR (40u+φ,
L/D・25, cylinder salinity 260° C.) to make pellets by melt extrusion.

The pellets were dried in a hot air dryer at 120° C. for 5 hours or more, and test pieces for measuring physical properties were molded using an injection molding machine and tested for physical properties.

The results are shown in Table 1.

For comparison, aromatic polycarbonate resin alone (comparative example -
1) Aromatic polycarbonate resin and high-density polyethylene (manufactured by Nippon Petrochemical Co., Ltd., product name: Stafrene E707)
, Ml・0.7g/10min, density 0.950g/cJ
) (Comparative Example-2), Ll, PR (manufactured by Nippon Petrochemical 0@, trade name, AF 1210, ■・O,
b/10 min, density 0.920 and 8J 531
0, old-8,0g710min, density 0.920)
The results for Comparative Examples 3 and 4 are also shown in Table 1 in the same manner as above.

In Table 1, the abbreviations and measurements of physical property values were as follows.

・IIDT (=heat distortion temperature): Load 18.6 kg
/cn・IZ (=Izot impact value): Unit with non-touch, kg-cm/cm・C1σy (=CCj!, medium bending strength): Unit sig
/cf [Operations and Effects of the Invention] As explained above in the detailed explanation, the ethylene carboxylic acid vinyl ester alkyl (meth) used in the present invention
The acrylate copolymer is clearly different from those made by conventional methods, and therefore, the composition of the present invention using this copolymer also exhibits excellent properties in terms of fluidity, heat resistance, and impact resistance. One thing is clear.

Claims (1)

[Scope of Claims] A, 70 to 99% by weight of aromatic polycarbonate resin, B, ethylene carboxylic acid vinyl ester alkyl (
A thermoplastic resin composition containing 1 to 30% by weight of a meth)acrylate copolymer and having excellent chemical resistance and impact resistance.