JPH086015B2 - Polycarbonate resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a polycarbonate resin composition, and more particularly to a polycarbonate resin composition having excellent mold release performance, heat resistance and hydrolysis resistance.

[Prior Art and Problems to be Solved by the Invention] Polycarbonate has excellent transparency, mechanical properties, and dimensional stability, and is therefore widely used in various fields.

In order to improve the antistatic property of the polycarbonate, an antistatic polycarbonate composition in which a fatty acid monoglyceride is contained in the polycarbonate has been proposed (Japanese Patent Publication No. 55-4141 (Japanese Patent Application No. 47-45934)).

However, since this compound does not have sufficient thermal stability, a thermally stable polycarbonate composition to which a phosphorus compound such as phosphorous acid or phosphite is further added has been proposed (Japanese Patent Publication No. 51-44552 (Japanese Patent Application No. 51-44552). (Sho 48-22257))).

However, when the phosphorus compound is added in an amount of 0.001% by weight (10 ppm) or more in terms of phosphorus atom, the hydrolysis resistance is extremely deteriorated.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above-mentioned drawbacks of the prior art, and to provide a polycarbonate resin composition having excellent heat resistance and hydrolysis resistance as well as excellent mold release performance.

[Means for Solving the Problems] That is, the present invention relates to (A) β-long side chain alcohol behenic acid ester or long chain aliphatic alcohol in an amount of 0.05 to 1 part by weight and ( B) A polycarbonate resin composition comprising at least one phosphorus compound selected from the group consisting of phosphorous acid and phosphite ester in an amount of 0 to 0.001 part by weight in terms of phosphorus atom.

The polycarbonate resin used as the base of the composition of the present invention is represented by the following general formula.

In the formula, R ¹ , R ² , R ³ and R ⁴ represent a substituent such as hydrogen atom, hydrocarbon or halogen atom.

Such a polycarbonate resin is prepared by a solvent method, that is, in the presence of a known acid acceptor and a molecular weight modifier in a solvent such as methylene chloride or the like, by reacting the dihydric phenol with a carbonate precursor such as phosgene or by dihydric phenol and carbonic acid. It can be produced by an ester exchange reaction with a carbonate precursor such as a diester (diphenyl carbonate).

Here, as the dihydric phenol that can be preferably used, there are bisphenols, and 4,4'-dihydroxyphenylpropane (bisphenol A) is particularly preferable. Also,
A part or all of bisphenol A may be replaced with another dihydric phenol. Examples of dihydric phenols other than bisphenol A include hydroquinone and
4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) alkane, bis (4-hydroxyphenyl) cycloalkane, bis (4-hydroxyphenyl)
Compounds such as sulfide, bis (4-hydroxyphenyl) sulfone, bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) ether or bis (3,5-dibromo-4-hydroxyphenyl) propane, bis ( Mention may be made of halogenated bisphenols such as 3,5-dichloro-4-hydroxyphenyl) propane. These dihydric phenols may be homopolymers of dihydric phenols or copolymers or blends of two or more. Further, the polycarbonate resin used in the present invention may be a thermoplastic random branched polycarbonate obtained by reacting a polyfunctional aromatic compound with a dihydric phenol and / or a carbonate precursor.

The polycarbonate resin used in the present invention has a viscosity average molecular weight of 10,0 from the viewpoint of mechanical strength and moldability.
Those of 100 to 100,000 are preferable, and those of 14,000 to 35,000 are particularly preferable.

In the present invention, β-long side chain alcohol behenic acid ester or long chain aliphatic alcohol is used as the component (A).

Here, the β-long side chain alcohol behenic acid ester is a compound having the following general formula.

Where R ⁵ is an alkyl group having 10 to 13 carbon atoms and R ⁶ is 10 carbon atoms.
To 11 alkyl group, R ⁷ is a behenyl group - shows the (C ₂₂ H _45).

Examples of such an ester include 2-tetradecene-dodecane behenate, 2-octadecene-dodecane behenate, 2-octadecene-undecene behenate, and among them, 2-tetradecene-dodecane behenate is preferable.

The long-chain aliphatic alcohol is represented by the general formula C _n H _{2n + 1} OH, and higher alcohols in which n is 25 or more are preferable, and examples thereof include hexacosanol-1, octacosanol-1, nacosanol, myricyl alcohol, and melicyl. Alcohol and the like are preferably used.

The blending amount of the component (A) is required to be 0.05 to 1 part by weight with respect to 100 parts by weight of the polycarbonate resin, and 0.07 to 0.8 part by weight is particularly preferable.
If the amount of the component (A) is less than 0.05 parts by weight, the release pressure is high, and abnormal noise is generated in the release agent in some cases.
Further, if the amount exceeds 1 part by weight, these additives may bleed out and cause clouding of the resin or deterioration of heat resistance, which is not preferable.

Further, in the present invention, at least one phosphorus compound selected from the group consisting of phosphorous acid and phosphorous acid ester is used as the component (B).

Here, the phosphite is usually used as a heat stabilizer or an antioxidant, and may be monophosphite or diphosphite. Examples of the monophosphite include tris (2,4-di-t-butylphenyl) phosphite; tris (mono- and di-nonylphenyl) phosphite and the like. The general formula for diphosphite is [In the formula, R ⁵ and R ⁶ may be the same or different and each represents an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms. And a specific example thereof is distearylpentaerythritol diphosphite;
Dioctylpentaerythritol diphosphite; diphenylpentaerythritol diphosphite; bis (2,
4-di-t-butylphenyl) pentaerythritol diphosphite; bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite; dicyclohexylpentaerythritol diphosphite;
Tetrakis (2,4-di-t-butylphenyl) -4,4'-
Biphenylene phosphite and the like can be mentioned.

Among these, trisnonylphenyl phosphite,
Aromatic phosphites such as trisphenyl phosphite are preferred.

The component (B) is used in a proportion of 0 to 0.0001 parts by weight, preferably 0 to 0.0008 parts by weight, calculated as phosphorus atoms, based on 100 parts by weight of the polycarbonate resin. When the component (B) is blended in an appropriate amount, it improves heat resistance and hydrolysis resistance, but when it exceeds 0.001 part by weight (10 ppm), the hydrolysis resistance is extremely deteriorated. In this sense, it is preferable to use the component (B) in a small amount as much as possible.
By using the component, the amount of the component (B) used was successfully reduced as much as possible.

Further, in the present invention, paraffin wax may be used as the component (C) if necessary.

It is preferable to use the paraffin wax having a softening point of 75 to 90 ° C., particularly preferably the softening point of 80 to 90 ° C. Further, the paraffin wax having an average carbon number of 37 to 40, particularly 38 to 40 is preferable.

Although such paraffin wax belongs to petroleum wax, it has a softening point different from that of microcrystalline wax, petroram, or the like.

The paraffin wax is usually solid or powdery, and in this case, the particle size is preferably about 1 mm, but it is of course also possible to heat and melt the solid above its softening point and add it by mixing. It is possible.

If the softening point of this paraffin wax is less than 75 ° C., the heat resistance will deteriorate and ΔYI in heat resistance evaluation will increase, which is not preferable. On the other hand, if it exceeds 90 ° C., the releasing pressure becomes high, the compatibility with the polycarbonate becomes poor, and the transparency is slightly lowered, which is not preferable. Such paraffin wax may be used as a mixture of two or more kinds.

When this paraffin wax is used as the component (C), 100 parts by weight of the above-mentioned polycarbonate resin is used.
The amount is 0.05 to 1 part by weight, preferably 0.1 to 0.6 part by weight. If the content of the component (C) is less than 0.05 parts by weight, the releasing pressure may be high, and noise may be generated during releasing. Both of them are not preferable because they occur.

When this component (C) is used, the respective compounding amounts of the component (A) and the component (C) are as described above,
Further, the total amount of the components (A) and (C) must be 0.1 to 1 part by weight, preferably 0.3 to 0.8 part by weight. If the total amount of both is less than 0.1 parts by weight, the release pressure is high and abnormal noise may occur during release, which is not preferable. On the other hand, if the total amount of both exceeds 1 part by weight, white turbidity occurs and the commercial value is significantly reduced, which is not preferable.

In the present invention, in addition to the components (A) and (B) and the component (C) optionally added, the object of the present invention is not impaired.
Further, various kinds of additives can be blended as necessary. For example, glass fibers, carbon fibers, metal fibers, inorganic fillers, metal powders, ultraviolet absorbers, flame retardants, colorants and the like can be added.

The polycarbonate resin composition of the present invention can be obtained by blending the above components and kneading. The compounding and kneading methods may be carried out by ordinary methods, for example, a ribbon blender, a Henschel mixer, a Banbury mixer, a drum tumbler, a single-screw extruder, a twin-screw extruder, a co-kneader, a multi-screw extruder, etc. . The heating temperature for kneading is usually
250 to 300 ° C is suitable.

[Examples] Next, the present invention will be described in detail with reference to Examples. Examples 1-11 and Comparative Examples 1-6 As shown in Table 1, polycarbonate resin (A),
Components (B) and (C) were blended, preliminarily kneaded with a drum tumbler, and then kneaded with an extruder at 270 ° C. to obtain a polycarbonate resin composition. This composition was tested by the following method. The results are shown in Table 1.

Test method Heat resistance method (ΔYI) 15 oz injection molding machine and runner part diameter 6 mm length 80 m
Using a mold that can form a molded piece of 80 mm square with a thickness of 3 mm with m,
Cylinder temperature 290 ℃, mold temperature 90 ℃, injection time 20
Seconds, cooling time 20 seconds, back pressure 5kg / cm ² G, screw speed 4
Molding was performed continuously at 6 rpm. 1st shot and 60
The yellow index (YI) was measured based on JIS K-7103 for the molded product of the shot eye, and the difference (ΔYI) was shown. The smaller ΔYI indicates the better heat resistance.

Mold release pressure (kg / cm ² ) Length 35mm, diameter 40-42mm, wall thickness 2mm
The pressure generated in the ejector was measured.

 Metal rust Visually.

Long-term heat resistance (ΔYI) A yellowness measurement test piece molded under the above standard molding conditions
After being left in an oven at 140 ° C. for 14 days, the yellow index was measured and the difference (ΔYI) is shown.

Hydrolyzability A yellowness measurement test piece molded under the standard molding conditions described above
The sample was exposed to a saturated steam atmosphere at 120 ° C for 48 hours, and the appearance change and the viscosity average molecular weight were measured. Decrease in molecular weight (Δ
M _v ).

[Effects of the Invention] The polycarbonate resin composition of the present invention as described above has excellent heat resistance and hydrolysis resistance, and also has good mold release performance. Therefore, various known molding methods such as injection molding, extrusion molding, compression molding, calender molding, rotational molding, etc. are applied to mold structural parts such as electric and electronic equipment, OA office machines and automobile parts, and particularly large-sized thin-walled parts. It is effective for injection-molded products that require products with good releasability.

Claims (1)

[Claims] 1. To 100 parts by weight of a polycarbonate resin, 0.05 to 1 part by weight of (A) β-long side chain alcohol behenic acid ester or long chain aliphatic alcohol and (B) phosphorous acid and phosphorus. A polycarbonate resin composition comprising at least one phosphorus compound selected from the group consisting of acid esters in an amount of 0 to 0.001 part by weight calculated as phosphorus atoms.