JPH04189864A - Polycarbonate-based resin composition for molding - Google Patents

Abstract

PURPOSE:To obtain a molding polycarbonate-based resin composition having excellent extrusion molding properties and heat molding properties without damaging heat resistance, etc., by blending a polycarbonate resin with specific amounts of a copolymer of an aromatic vinyl monomer and a vinyl cyanide monomer with a specific thermoplastic resin of multiple phase structure. CONSTITUTION:(A) 100 pts.wt. polycarbonate resin having >=25000 viscosity- average molecular weight is blended with (B) 5-50 pts.wt. copolymer of 85-60wt.% aromatic vinyl monomer (e.g. styrene) and 15-40wt.% vinyl cyanide monomer (e.g. acrylonitrile) and (C) 5-25 pts.wt. thermoplastic resin of multiple phase structure comprising 20-90wt.% ethylenic copolymer and 80-10wt.% vinyl- based (co)polymer (preferably 10-5,000 number-average polymerization degree) obtained from one or more vinyl monomers.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates to a polycarbonate resin composition suitable for extrusion moldability and thermoformability. The present invention relates to a polycarbonate resin composition for molding which has less drawdown during processing and is improved in its ability to be deep drawn.

[Prior Art and Problems] Due to its excellent mechanical and thermal properties, polycarbonate resin compositions are formed into sheets by extrusion molding, and then vacuum molding, pressure forming, etc. are applied. It is thermoformed into various shapes and used for electrical and electronic equipment, OA equipment,
Housings for automobile parts, interior materials for vehicles, aircraft, etc.
It is also used as a material for various building materials.

However, conventional polycarbonate resin compositions have problems such as large sheet drawdown during thermoforming and difficulty in deep drawing at a high molding ratio.
A drawback is that it is extremely difficult to finish the molded product into a desired shape.

In order to eliminate such drawbacks in thermoforming of polycarbonate resin compositions, a method has been proposed in which polycarbonate resin is mixed with other highly fluid resins1.For example, polycarbonate resin and polybutadiene graft copolymer Mixture I (for example, Japanese Patent Publication No. 38-15225,
(Japanese Patent Publication No. 39-71), a mixture of polycarbonate resin, polymethyl methacrylate and acrylonitrile styrene copolymer (for example, Japanese Patent Publication No. 43-13384
), acrylate styrene-acrylonitrile copolymer mixture (1) (for example, Japanese Patent Publication No. 48-29308), and the like.

However, although all of the above polycarbonate resin compositions have high fluidity and exhibit performance suitable for so-called injection molding, their fluidity is too high for extrusion molding, making extrusion work difficult. In particular, mixtures that cannot be made into polycarbonate resin compositions suitable for extrusion molding, and furthermore, the impact resistance, which is an inherent characteristic of polycarbonate resins, are significantly reduced, and furthermore, physical properties such as heat resistance and rigidity are reduced. (2) exhibits a pearl-like luster and is not suitable for applications that require arbitrary coloring properties.

Means for Solving the L Problem] This invention solves the above-mentioned conventional drawbacks, and improves mechanical properties such as heat resistance, impact resistance, and rigidity, which are inherent characteristics of polycarbonate vIJ resin, and good appearance quality. The object of the present invention is to provide a moldable polycarbonate resin composition that maintains the properties of the polycarbonate resin and has improved extrusion moldability and thermoformability.

That is, this invention uses polycarbonate resin (A) 10
0 parts by weight, 5 to 50 parts by weight of a copolymer (B) of an aromatic vinyl monomer and a vinyl cyanide monomer, an alkyl ester copolymer of an ethylenically unsaturated carboxylic acid, and at least one vinyl monomer. Thermoplastic resin (C) with a multiphase structure consisting of a vinyl polymer or copolymer obtained from a polymer (C) 5 to 2
The gist is a polycarbonate resin composition for molding consisting of 5 parts by weight of each component and component amount.

The polycarbonate resin of component (A) used in this invention is an aromatic polycarbonate resin produced from an aromatic dihydroxy compound and a carbonate precursor by a solvent method or a melt method.

Examples of aromatic dihydroxy compounds include 2.2-bis(4-hydroxyphenyl)propane (i.e., bisphenol A), bis(4-hydroxyphenyl)alkane, and 2.2-bis(4-hydroxy-3,5-dimethyl). Examples include compounds such as phenyl)propane, bis(4-hydroxyphenyl)sulfide, and bis(4-hydroxyphenyl)sulfone, which can be used alone or in combination of two or more.

Examples of the carbonate precursor include carbonyl halides such as phosgene, carbonyl esters such as diphenyl carbonate, and mixtures thereof.

Usually, aromatic polycarbonate resins are produced from an aromatic dihydroxy compound and phosgene by a solvent method, or from an aromatic dihydroxy compound and a diphenyl compound by a melt method.

In addition, the polycarbonate resin used in this invention is
Some of them may be branched, and include, for example, thermoplastic randomly branched polycarbonate resins prepared by reacting a polyfunctional aromatic compound with a dihydric phenol and a carbonate precursor.

Furthermore, regarding the molecular weight of the polycarbonate resin, the viscosity average molecular weight calculated from the intrinsic viscosity measured in methylene chloride at 20° C. is 25°,000 or more, preferably 27,000 or more.

That is, if the average molecular weight is less than 25,000, the drawdown during thermoforming of the sheet will be large, the moldability will be reduced, and the impact resistance will also be reduced, making it impractical.

Component CB) is then produced by polymerizing an aromatic vinyl monomer and a vinyl cyanide monomer by any of the following methods: bulk polymerization, suspension polymerization, emulsion polymerization or a combination thereof. .

Examples of the aromatic vinyl monomer used here include styrene, α-methylstyrene, vinyltoluene, vinylxylene, trimethylstyrene, and halogenated styrene. Examples of vinyl cyanide monomers include acrylonitrile and methacrylonitrile.

Examples of the most preferred combinations of aromatic vinyl monomers and vinyl cyanide monomers include styrene-acrylonitrile copolymers, α-styrene-acrylonitrile copolymers, and ortho-styrene-acrylonitrile copolymers. .

The copolymerization ratio of the aromatic vinyl monomer and the vinyl cyanide monomer is 85 to 60% by weight of the aromatic vinyl monomer,
The vinyl cyanide monomer content is 15 to 40% by weight. In this case, if the vinyl cyanide monomer is less than 15% by weight, the rigidity of the polycarbonate resin composition for molding will be low, and if it is more than 40% by weight, the impact resistance of the composition will be low. I don't like it because it has a tendency.

The molecular weight of the copolymer of component (B) is such that the number average molecular weight determined by gel permeation chromatography using a polystyrene standard sample and tetrahydrofuran as a solvent is 80.000 or more. 00
If it is less than 0, the impact resistance and heat resistance of the sheet will decrease, and if this average molecular weight becomes too small, the difference in melt viscosity with the polycarbonate resin of the component (A>) will increase, resulting in a decrease in compatibility. Extrusion molding becomes difficult.

Component (C) is a multiphase thermoplastic resin comprising an ethylene copolymer and a vinyl polymer or copolymer obtained from at least two vinyl monomers.

Here, the ethylene copolymer refers to ethylene monomer 50
It is an ethylene-alkyl ester copolymer of an unsaturated carboxylic acid consisting of ~95% by weight and 50-5% by weight of an alkyl ester of an unsaturated carboxylic acid.

Examples of the ethylene copolymer include ethylene-methacrylic acid copolymer, ethylene-ethyl acrylate copolymer, and the like.

In addition, monomers of the alkyl esters of unsaturated carboxylic acids include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, propyl acrylate, propyl methacrylate, isopropyl acrylate, and methacrylate. Isopropyl acid, acrylic acid
〇-Butyl, 〇-butyl methacrylate, cyclohexyl acrylate, cyclohexyl methacrylate, lauryl acrylate, lauryl methacrylate, stearyl acrylate, stearyl methacrylate, monomethyl maleate, monoethyl maleate, Examples include diethyl maleate and monomethyl fumarate.

Furthermore, the vinyl polymer or copolymer herein refers to styrene, methylstyrene, dimethylstyrene, ethylstyrene, isopropylstyrene, chlorstyrene, α-
Aromatic vinyl monomers such as methylstyrene, α-ethylstyrene, methyl acrylic acid or methacrylate,
Ester monomers with ethyl, propyl, isopropyl, butyl, etc., acrylonitrile or methacrylonitrile ammonium; vinyl ester monomers such as vinyl acetate, vinyl propionate, acrylamide or methacrylamide monomers; maleic anhydride, maleic It is a polymer or copolymer obtained by polymerizing one or more types of vinyl monomers such as acid monoesters and diesters. Among them, vinyl polymers or copolymers containing 50% by weight or more of ester monomers of acrylic acid or methacrylic acid are preferable because they have less deterioration in impact resistance, which is a feature of polycarbonate resins.

The multiphase thermoplastic resin referred to in the second invention is a polymer or copolymer that forms 7 trixes when the other polymer or copolymer made of a different component is uniformly dispersed in a spherical shape. It is.

The particle size of the dispersed polymer or copolymer is 0001 to 1
It is 0 μm, preferably 0.01 to 5 μm. If the particle size is less than 0,001 μm or more than 10 μm, the dispersibility when mixed with the polycarbonate resin is poor, for example, the appearance deteriorates and the impact resistance decreases, which is not preferable.

In addition, the number average degree of polymerization of the vinyl polymer or copolymer in the multiphase structure thermoplastic resin is 5 to 10,000, preferably tL<
is 10-5.000. If the number average degree of polymerization is less than 5, the heat resistance of the polycarbonate resin composition for molding of the present invention will decrease, which is not preferable.
If it exceeds 7-0, the melt viscosity becomes high, resulting in poor extrusion moldability, and 2) the surface gloss decreases, which is not preferable.

The thermoplastic resin having a multiphase structure as component (C) preferably contains 20 to 90% by weight of an ethylene copolymer and 80 to 10% by weight of a vinyl polymer or copolymer.

If the ethylene copolymer content is less than 20% by weight, the impact resistance of the polycarbonate resin composition for molding will decrease, which is undesirable, and if it exceeds 90% by weight, the heat resistance and rigidity of the polycarbonate resin composition for molding will deteriorate. This is not preferable because it tends to reduce the

Next, the amounts of component (B) and component (C) relative to component (A>) of the polycarbonate resin composition for molding of the present invention will be described.

First, if component (B) is less than 5 parts by weight, it will not be possible to reduce the drawdown of the plate during thermoforming, making it impossible to finish the molded product into the desired shape, and not only will it not be possible to maintain sufficient rigidity. I can't. If the amount exceeds 50 parts by weight, the compatibility with component (A) will significantly decrease regardless of the presence of component (C) as a compatibilizer, causing delamination in the extruded sheet and 1ii1 impact resistance. decreases significantly.

In addition, component (C) acts as a compatibilizer to improve the compatibility between component (A) and component (B), and when the amount is less than 5 parts by weight, it acts as a compatibilizer. The action and effect of the film become insufficient, and the sheet also suffers from delamination, resulting in a decrease in impact resistance.

If the amount exceeds 25 parts by weight, the effect as a compatibilizer will increase and the impact resistance will improve, but on the other hand, the drawdown during thermoforming will increase, the heat resistance and rigidity will decrease, and a satisfactory molded product cannot be obtained. do not have.

Therefore, the component ratio of the composition of this invention is component (A) 10
0 parts by weight, 5 to 50 parts by weight of component (B), component (C
)5 to 25 parts by weight.

The polycarbonate resin composition for molding according to the present invention can be obtained by blending the above components (A) to (C) in a predetermined ratio, and any commonly known blending method may be used. . For example, a method of mixing using a mixer such as a Henschel mixer or a tumbler;
and a method of kneading using a Banbury mixer, kneader 1 melt extruder, etc. and then forming pellets.

In addition, the polycarbonate resin composition for molding according to the present invention can be added in the same manner as ultraviolet absorbers, colorants, lubricants, etc. that are usually added to polycarbonate resins.

In order to form a sheet from the composition of this invention, extrusion molding means generally used for sheet forming of polycarbonate resin is applied, and in order to thermoform the sheet, generally known vacuum forming method, vacuum/pressure forming method, Press molding method etc. are applied.

[Function] According to the molding polycarbonate resin composition of the present invention, the component (A) which is a polycarbonate resin is ) while maintaining its impact resistance and heat resistance, and reducing drawdown during thermoforming, which is a drawback.
A component (C
) can compensate for the low compatibility between component (A) and component (B) and prevent layer peeling, deterioration of surface texture, and deterioration of impact resistance caused by this.

1 Example] Next, examples of the present invention will be described together with comparative examples.

First, the component contents of Examples and Comparative Examples will be described below.

A1: Polycarbonate resin with an average molecular weight of 27,000 (trade name: "Nipilon", manufactured by Mitsubishi Gas Chemical Co., Ltd.) A2: Polycarbonate resin with an average molecular weight of 18,000 (trade name: "Nipilon J", manufactured by Mitsubishi Gas Chemical Co., Ltd.) B1: Styrene monomer B2. Copolymer consisting of 70% by weight of styrene monomer, 30% by weight of acrylonitrile monomer, average molecular weight of 1oo, ooo (trade name "Stylac JT-8705, manufactured by Asahi Kasei Corporation)" B2. 70% by weight of styrene monomer, acrylonitrile monomer A copolymer consisting of 30% by weight of C1 ethyl acrylate and an average molecular weight of 6o, ooo (trade name: Stylac JT-8707, manufactured by Asahi Kasei Corporation). 70% by weight of ethylene-ethyl acrylate copolymer with 20% by weight of C1 ethyl acrylate. % and styrene polymer 30
C2: 70% by weight of ethylene-ethyl acrylate copolymer similar to C1 and 30% by weight of methyl methacrylate polymer A graft copolymer consisting of % by weight (same as CI < A-52
C3: Graft copolymer consisting of 70% by weight of ethylene-ethyl acrylate copolymer similar to C1 and 30% by weight of styrene-acrylonitrile copolymer (A-5400, same as C1) In C4/C2, ethylene- A graft copolymer consisting of 50% by weight of ethyl acrylate copolymer and 50% by weight of methyl acrylate polymer (based on the above components of A-5, same as C2). <The amounts of each component in Examples and Comparative Examples are shown in Table 1.

Next, for Examples 1 to 10, sheets P were manufactured by extrusion molding according to the component amounts shown in Table 1.

That is, the amounts of each component were blended, mixed in a tumbler, and then molded using an extruder with a cylinder inner diameter of 50 mm at an extrusion temperature of 280 DEG C. to produce a sheet with a thickness of 30 liters.

Furthermore, for Comparative Examples 11 to 19, extrusion molding was performed in accordance with the component amounts in Table 1 in the same manner as in the examples to try to manufacture sheets.

Comparison The extrusion moldability, sheet appearance, and
Each item of physical properties (impact resistance, heat resistance, rigidity) and thermoformability (drawdown, deep drawability, thickness retention) will be compared.

-Extrusion moldability- Table 2 Note: Extrusion moldability: ○ indicates that the extrusion fluctuation is small and the discharge rate is high and stable; otherwise, it is rated ×.

A sheet with good surface gloss and a clean skin with no layer peeling was rated O5, and a sheet with poor surface appearance was rated x.

(Hereinafter, blank space) Those with little extrusion fluctuation, stable flow, and excellent discharge amount were rated as ○, and those with poor extrusion were rated as ×.

As shown in Table 2, all of the Examples had good extrusion moldability, but in Comparative Examples 12 and 16, the viscosity during molding was extremely low, making extrusion molding impossible and making it difficult to obtain a sheet. could not.

-Sheet Appearance- A sheet with good surface gloss and clean skin was rated as ○, and a sheet with poor surface gloss was rated as ×.

As shown in Table 2, all of the Examples had good sheet appearance, but Comparative Example 11 had significantly poor gloss and skin, and layer peeling occurred. Both gloss and skin were poor, and layer peeling occurred, although to a lesser extent.

This indicates that the compatibility between component (A) and component (B) is poor.

Regarding physical properties and impact resistance, as shown in Table 3, in Examples,
Ordinary polycarbonate resin (Comparative Example 1 Table 3 Note, Measuring method Impact resistance: ASTM D256 Izot method (with notch) measuring method (Unit: kgf-c+a/cm) Heat resistance: ASTM D648 (Load: 18.5 kg
f/cm2) (unit: °C) Rigidity: Corresponds to ASTM D790 flexural modulus measurement method (unit: ), but all showed impact resistance values that could withstand practical use. On the other hand, Comparative Example 11.1
In No. 3 and No. 14, the impact resistance values were significantly lowered due to poor compatibility between component (A) and component (B). In particular, for Comparative Example 14, the component (C
) despite the addition of a significant amount of component (B)
This was caused by In addition, the low impact resistance value of Comparative Example 18 is due to the low average molecular weight of component (A) A2. 6 Also, regarding the heat resistance, there is no significant difference in heat resistance in any of the examples compared to that of ordinary polycarbonate resin. Ta.

Furthermore, with regard to rigidity, the examples showed values of flexural modulus that were higher than those of ordinary polycarbonate resins, but which were sufficient for practical use.

-Thermoformability- First, for drawdown, use a vacuum forming machine,
It was measured by the amount of drooping of the sheet due to heat softening (unit: -). That is, as shown in Fig. 1, the sheet (1) is 405 wa x 610 wa in length.
4 Note: Deep drawing formability: Normal ones were rated ○, and those with tearing were rated ×.

Thickness retention rate: The average value of the thickness of the molded body at each point P in FIG. 2 was rated ○ if it was 20% or more of the sheet thickness.

Clamps (3) and (4) (hereinafter referred to as margins) are used to sandwich the sheet from above and below, and heated at a heater temperature of 400°C for 120 seconds. A distance 111 (H) was measured.

As a result, as shown in Table 4, the amount of droop in each example was within about 605 m, which was clearly smaller than in the comparative example.

As for deep drawability, the sheet (1) was heated for 120 seconds (plate temperature 180''C) L and the forming magnification was 4 times to see if vacuum forming was possible in the same manner as in the case of drawdown.

As a result, as shown in Table 4, in the example, a box-shaped body (2) of 400 m in length, 600 m in width, and 360 cm in height as shown in Fig. 2 could be obtained, but in the comparative example, The molded product also broke and a normal molded product could not be obtained.

Furthermore, regarding the thickness retention rate, the thickness at each point P in FIG. 2 was measured for each of the deep-drawn molded bodies.

As a result, as shown in Table 4, all of the Examples showed sufficient thickness retention.

〔Effect of the invention〕

As described above, the polycarbonate resin composition for molding according to the present invention includes a polycarbonate resin, a copolymer of an aromatic vinyl ammonium and a cyanide vinyl ammonium, and a multiphase thermoplastic resin as a compatibilizer. Because it contains resin, it maintains the physical properties of conventional polycarbonate resin, such as heat resistance, impact resistance, and rigidity, without major changes, and also has no delamination and a good surface texture. , a sheet with excellent appearance quality can be obtained. Furthermore, there is less drawdown during thermoforming, which is a drawback of conventional methods.
Moreover, the molding magnification can be increased, so-called deep drawing becomes possible, the thermoforming operation becomes extremely easy, and the range of uses of the molded product can be expanded.

[Brief explanation of the drawing]

FIG. 1 is an enlarged sectional view of main parts showing the state of sheet molding of the polycarbonate resin composition for molding according to the present invention, and FIG.
The figure is a longitudinal cross-sectional view of a box-shaped body formed from the same sheet. (1)...Sheet (2)...Box forming body 5 (
3)〈4)・・・Clamp and above Patent applicant Tsutsunaka Plastic Industry Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] 100 parts by weight of polycarbonate resin (A), copolymer of aromatic vinyl monomer and vinyl cyanide monomer (B) 5
~50 parts by weight, and 5 to 25 parts by weight of a multiphase thermoplastic resin (C) consisting of an ethylene copolymer and a vinyl polymer or copolymer obtained from at least one vinyl monomer. A polycarbonate resin composition for molding.