JPH07324159A - Polycarbonate resin composition - Google Patents

Abstract

PURPOSE:To obtain a polycarbonate resin composition which has improved flow and can give a product not suffering from delamination and improved in the dependency of impact strength on thickness without detriment to mechanical properties and surface appearance by mixing a polycarbonate resin with an aliphatic polyester resin. CONSTITUTION:This composition is prepared by mixing 70-99 pts.wt. polycarbonate resin obtained by reacting a 2,2-bis(4-hydroxyphenyl)alkane with a carbonate precursor such as phosgene or diphenyl carbonate and having a weight-average molecular weight (in terms of the molecular weight of PS as measured in gel permeation chromatography) of 30000-5000000 with 30-1wt.% aliphatic polyester resin obtained by adding 0.1-5 pts.wt. diisocyanate to a hydroxyl-terminated polyester of a number-average molecular weight of 5000 or above.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polycarbonate resin composition. More specifically, the present invention relates to a polycarbonate resin composition having improved fluidity and impact strength thickness dependency while maintaining mechanical properties and surface appearance.

[0002]

2. Description of the Related Art Polycarbonate resin is widely used mainly in electric and electronic fields as an engineering plastic having excellent impact resistance, heat resistance and dimensional stability among thermoplastic resins. However, it has a serious drawback that the melt viscosity is high and the flowability is poor, and the impact strength is highly dependent on thickness. For this reason, studies have been widely conducted to overcome the above drawbacks by alloying a polycarbonate resin with another thermoplastic resin.

It is generally known that the thickness dependence of impact strength can be improved by mixing a polyolefin resin with a polycarbonate resin. However, since the compatibility of both components is originally extremely poor, when this composition is formed into a molded article by a method such as injection molding, delamination occurs, physical properties are deteriorated and surface appearance is significantly deteriorated, and an effect of improving fluidity is also obtained. It has the drawback of being difficult. A technique for improving the compatibility between a polyolefin resin and a polycarbonate resin by grafting a molecule having a reactive group such as an acid anhydride onto the polyolefin resin and using this as a compatibilizing agent is disclosed in, for example, JP-A-57 / 57.
No. 123251, JP-A-59-223742 and the like. However, since the terminal of the polycarbonate resin is usually sealed with alkylphenols, the reactivity is poor and the effect as a compatibilizing agent cannot be expected.

[0004]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention has no delamination and maintains mechanical properties and surface appearance.
Moreover, it is an object of the present invention to provide a resin composition having improved fluidity and impact strength dependency on thickness.

[0005]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that the above objects can be achieved by adding a polyester resin having a specific structure to an aromatic polycarbonate resin. The present invention has been completed. That is, the present invention, a polycarbonate resin,
Thickness of fluidity and impact strength while maintaining mechanical properties and surface appearance, consisting of a polyester copolymer synthesized from glycols and aliphatic polybasic acids (hereinafter abbreviated as "aliphatic polyester resin") The present invention relates to a resin composition having improved dependency.

The aromatic polycarbonate resin used in the present invention is a product produced by reacting a dihydric phenol with a carbonate precursor by a known method such as a solution method or a melting method. Typical dihydric phenols are hydroquinone, resorcinol, 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane, and 2,2-bis (4-hydroxy-3,5-).
Dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2
-Bis (4-hydroxy-3-methylphenyl) propane, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone and the like can be mentioned. A bis (4-hydroxyphenyl) alkane system is particularly preferable, and 2,2-bis (4-hydroxyphenyl) propane, which is usually referred to as bisphenol A, is particularly preferable. Further, examples of the carbonate precursor include carbonyl halide, carbonyl ester, haloformate and the like, and specific examples include phosgene, diphenyl carbonate, dihaloformate of dihydric phenol and the like.
In the production of the polycarbonate resin, addition of an appropriate molecular weight modifier, branching agent, other modifier, etc. may be carried out. Further, each of the dihydric phenol and the carbonate precursor may be used alone or in combination of two or more kinds, and the obtained polycarbonate resin may be used in combination of two or more kinds. In the present invention, a polycarbonate resin containing bisphenol A as a main raw material gives good results.

The aliphatic polyester resin in the present invention is a polyester copolymer produced from a glycol and an aliphatic polybasic acid as raw materials by a method such as a solution method or a melting method. Examples of glycols include ethylene glycol, 1,4-butanediol, 1,6-
Hexanediol, decamethylene glycol, neopentyl glycol, 1,4-cyclohexanedimethanol and the like can be mentioned. Examples of the aliphatic polybasic acid that reacts with these glycols to form a polyester include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanoic acid, succinic anhydride, adipic anhydride and the like. The combination of glycols and polybasic acids is
Any combination of the above compounds may be used. In particular, 1,
Combinations of 4-butanediol and succinic acid and ethylene glycol and succinic acid are preferred.

Further, the aliphatic polyester resin may contain diisocyanates as a molecular chain extender in order to increase its molecular weight. Examples of diisocyanates include 2,4-tolylene diisocyanate, 1,
5-naphthylene diisocyanate, diphenylmethane diisocyanate, xylylene diisocyanate, hydrogenated xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and the like can be mentioned.

To obtain the high molecular weight polyester resin, for example, a number average molecular weight of 5,000 or more, preferably 1
After synthesizing a polyester having a hydroxyl group of 50,000 or more and having a terminal hydroxy group, 0.1 to 5 parts by weight of diisocyanate may be added in a molten state of the polyester. Such an aliphatic polyester resin can be easily obtained, for example, as "Bionore (trademark)" manufactured by Showa High Polymer Co., Ltd.

There is no particular limitation on the molecular weight of the polycarbonate resin and the aliphatic polyester resin used in the present invention, and a commonly used injection molding grade may be used.
However, it is preferable that the aliphatic polyester resin has a relatively large molecular weight from the viewpoint of thermal and mechanical properties. Specifically, the weight average molecular weight measured by gel permeation chromatography is 30,000 to 5,000,0.
A value of 00 (value in terms of polystyrene) is suitable. When the molecular weight is larger than this, the effect of improving the fluidity becomes poor, which is not preferable.

In the composition of the present invention, the polycarbonate resin and the aliphatic polyester resin are used in an arbitrary ratio, but from the viewpoint of improving the fluidity of the polycarbonate resin and the thickness dependence of the impact strength, which are the features of the present invention. A ratio of 70 to 99 parts by weight for the former and 30 to 1 parts by weight for the latter give good results. The former is 80 to 95 parts by weight from the viewpoint of maintaining thermal and mechanical properties and improving fluidity.
It can be said that the latter is particularly suitable in the range of 20 to 5 parts by weight. When the amount of the polycarbonate resin is 70 parts by weight or more, the heat resistance characteristic of the polycarbonate resin is not impaired, which is preferable.

The above-mentioned composition contains various elastomers, other thermoplastic resins having good compatibility with the polycarbonate resin, plasticizers, pigments, stabilizers, release agents, flame retardants within the range not impairing the characteristics of the present invention. , Other additives and fillers can be appropriately used according to the purpose and application. The method for producing the resin composition of the present invention is not particularly limited, and a commonly known method can be adopted. That is, after uniformly mixing the polycarbonate resin, the aliphatic polyester resin and other necessary components with a high speed stirrer or the like, melt kneading with a uniaxial or multiaxial extruder having sufficient kneading ability, a mixing roll, a kneader, a Brabender, etc. Can be manufactured by a method such as After dissolving and swelling both components in a suitable solvent and stirring mechanically or using ultrasonic waves, etc.,
A method of evaporating the solvent and concentrating it is also effective.

[0013]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples.

Examples 1 to 2 Aliphatic polyester resin mainly composed of 1,4-butanediol and succinic acid (Bionole 1020, manufactured by Showa Highpolymer Co., Ltd., hereinafter "aliphatic polyester resin 1") and polycarbonate A resin (manufactured by Teijin Kasei Co., Ltd., Panlite L-1225) was blended in the proportions shown in Table 1 and thoroughly mixed with a tumbler mixer, and then the screw diameter 37 mm, L / D = 32 in a twin-screw extruder. , Melting temperature 230 ℃, screw rotation speed 80rp
m was melt-mixed and extruded to obtain a pelletized molding material composition. The composition obtained by the above method was added to the composition of 260-240.
A test piece was molded by an injection molding machine set at ℃, and each physical property was measured. The results are shown in Table 1. The thickness dependence of impact strength and the spiral flow length were improved, and good results without delamination were obtained.

[Examples 3 to 4] Aliphatic polyester resin 2 mainly composed of 1,4-butanediol, succinic acid and adipic acid (manufactured by Showa Highpolymer Co., Ltd., Bionole 3020,
Hereinafter, the same evaluation was performed using "aliphatic polyester resin 2". The results are shown in Table 1. Also in this case, good results were obtained.

[Comparative Examples 1-2] Instead of the aliphatic polyester resins 1-2 used in Examples 1-4, polypropylene resin (Noblene J3H, manufactured by Mitsui Toatsu Chemicals, Inc., hereinafter "polyolefin resin") Was evaluated in the same manner. The results are shown in Table 2. In this case, addition of the polyolefin resin causes a decrease in tensile strength at break and elongation, and delamination of the fracture surface is observed, which is not preferable.

[Comparative Examples 3 to 4] Instead of the aliphatic polyester resins 1 and 2 used in Examples 1 to 4, a polypropylene resin modified with maleic anhydride (having a maleic acid graft ratio of 1 wt%, hereinafter referred to as "modified" The same evaluation was performed using "polyolefin resin"). The results are shown in Table 2. This case is also not preferable for the same reason as in Comparative Examples 1 and 2.

[Comparative Example 5] This is the result of performing the same evaluation using a polycarbonate resin alone. The results are shown in Table 2.

In the above Examples and Comparative Examples, each physical property was evaluated as follows. (1) Izod impact test (impact value) Based on JIS-K7110. The thickness of the test piece is 1 /
8 "and 1/4". (2) Tensile test (tensile breaking strength, breaking elongation) Based on JIS-K7113. Further, the fracture surface was visually observed to evaluate the degree of delamination. Here, those without delamination were rated as “none”, and those with a large degree were rated as “present”. (3) Spiral flow flow length Using an Archimedes type spiral mold (flow thickness 1 mm, flow width 10 mm), resin temperature 280 ° C., mold temperature 10
The flow length was measured under the condition of 0 ° C.

[0020]

[Table 1]

[0021]

[Table 2]

[0022]

EFFECT OF THE INVENTION The polycarbonate resin composition of the present invention is capable of maintaining mechanical properties and surface appearance without delamination, and improving fluidity and thickness dependence of impact strength.
Its application is not limited to the conventional polycarbonate resin, and it can be applied to various fields such as electric / electronic / mechanical parts.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Sachino Sachino 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Chemical Co., Ltd. (72) Koichi Sano 1190 Kasama-cho, Sakae-ku, Yokohama-shi, Kanagawa Mitsui Toatsu Inside Chemical Co., Ltd.

Claims (2)

[Claims] 1. A resin composition comprising a polycarbonate resin and an aliphatic polyester resin. 2. The resin composition according to claim 1, wherein the polycarbonate resin is 70 to 99 parts by weight and the aliphatic polyester resin is 30 to 1 parts by weight.