JP2667974B2 - Polycarbonate resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial application field) The present invention relates to a polycarbonate composition having improved slipperiness and blocking resistance without significantly impairing transparency.

(Problems to be solved by the prior art and the invention) Polycarbonate has excellent properties such as impact resistance, heat resistance, transparency, dimensional stability, electrical insulation, flame retardancy, and fragrance retention, and forms a film. Taking advantage of its excellent ability, it can be used for food packaging and electrical applications (insulation barrier,
It is used in a wide range of applications such as capacitors), nameplate applications (automobiles, home appliances, etc.), and agricultural applications.

However, polycarbonates having such excellent physical properties are not completely free from defects, and their problems include lack of slipperiness and blocking resistance. Polycarbonate tends to cause poor winding and poor opening during T-die extrusion molding and blown film processing, and thus has a major problem in improving productivity.

In general, methods for improving the slipperiness and blocking resistance of a film have been disclosed in JP-A-58-42432 and JP-A-58-18054.
As shown in 1, there is a method of adding an inorganic filler.
However, the addition of inorganic filler alone is not sufficient in slipperiness and blocking resistance, and if the amount is increased until it is improved, the voids generated by the inorganic filler as a nucleus lower the commercial value of the film and can be satisfied. is not.

(Means for Solving the Problems) In view of such circumstances, the present inventors have conducted various studies to improve the slipperiness and the blocking resistance without greatly impairing the transparency, and as a result, have identified the specified finely divided silica. The present invention has been found a polycarbonate composition containing a fatty acid and an ester or partial ester of a monohydric or polyhydric alcohol.

That is, the present invention is based on 100 parts by weight of 2,2-bis (4'-hydroxyphenyl) propane-based polycarbonate, 0.005 to 0.005 parts by weight of finely divided silica having an average particle diameter of 3 microns or less.
1 part by weight and an ester or partial ester of an aliphatic saturated monohydric carboxylic acid having 10 to 30 carbon atoms and an aliphatic saturated monohydric alcohol or polyhydric alcohol having 30 or less carbon atoms
The present invention provides a polycarbonate resin composition which is blended in an amount of 0.005 to 5 parts by weight and has excellent transparency, slipperiness and blocking resistance.

The 2,2-bis (4'-hydroxyphenyl) propane-based polycarbonate in the present invention means 2,2-bis (4 '
(Hydroxyphenyl) propane and a polycarbonate produced by a generally known solution polymerization method or melt polymerization method from phosgene or diphenyl carbonate. In addition, the following general formula [Where X is as well as Represents a divalent residue selected from the group consisting of: R represents a monovalent residue selected from the group consisting of a hydrogen atom, a hydrocarbon group and a halogen atom. However, 2,2-bis (4'-hydroxylphenyl) propane is excluded. ] Polycarbonate obtained by copolymerizing a compound represented by
A branched polycarbonate obtained by copolymerizing a small amount of a compound having one or more phenolic hydroxyl groups is also included.

The viscosity average molecular weight of the polycarbonate suitable for the present invention is
It is over 15,000.

If it is less than 15,000, stability during film formation, that is, drawdown tends to occur during T-die extrusion molding, and there is a problem in valve formation stability during inflation film formation, which is not appropriate. Preferably it is 15,000-100,000.

The finely divided silica used in the present invention has an average particle diameter of 3 μm.
These are:

When the average particle diameter of the finely divided silica exceeds 3 μm, transparency due to generation of voids is greatly impaired. Preferably 0.1-3
μ. The average particle diameter according to the present invention is measured by the Coal counter method. The compounding amount of finely divided silica is 0.005 to 1 part by weight, preferably 0.01 to 0.1 part by weight, based on 100 parts by weight of polycarbonate. If the amount is less than 0.005 part by weight, the improvement of the blocking resistance is not sufficient, and if it exceeds 1 part by weight, the transparency is significantly reduced.

In the present invention, an ester or a partial ester of an aliphatic saturated monohydric carboxylic acid having 10 to 30 carbon atoms and an aliphatic saturated monohydric alcohol or polyhydric alcohol having 30 or less carbon atoms (hereinafter abbreviated as fatty acid esters) Are, for example, beeswax containing myristyl palmitate as a main component, ethylene glycol ester of montanic acid, pentaerythritol tetrastearate, neopentylene glycol distearate, glycerin monostearate, glycerin distearate, 12- (octadeca Noyloxy) octadecanoic acid-2-octyldodecyl ester.

The amount of these fatty acid esters is polycarbonate
The amount is 0.005 to 5 parts by weight, preferably 0.05 to 1 part by weight, based on 100 parts by weight. If the amount is less than 0.005 parts by weight, the dispersibility of the finely divided silica is not improved. If the amount exceeds 5 parts by weight, a large amount of fatty acid esters bleed on the film surface, which is not practical.

In the present invention, the addition of the finely divided silica and the fatty acid ester to the polycarbonate is an essential condition, and the addition of any one of them can provide a polycarbonate resin composition having good transparency and excellent slipperiness and blocking resistance. Can not.

Moreover, as a method of processing the polycarbonate resin composition in the present invention into a film, a T-die extrusion processing, an inflation film processing, a calendering method and the like are usually mentioned. If necessary, combine the stretching process,
Lamination by co-extrusion or lamination with a resin other than the polycarbonate resin, for example, polymethyl methacrylate, polypropylene, polyethylene, vinyl acetate, tetrafluoroethylene and the like is also possible.

Antioxidants, weathering agents, dyes, pigments, non-dripping agents, flame retardants, antistatic agents and the like can be appropriately added to the polycarbonate used in the present invention.

Next, the present invention will be described with reference to examples, but these are illustrative and the present invention is not limited thereto.

 Physical properties in the examples were measured by the following test methods.

Average particle size: weight fraction 50 by Coulter counter method
% Expressed as the diameter of the fine powder.

Specific surface area: BET method by nitrogen adsorption at liquid nitrogen temperature Transparency: Haze value Compliant with ASTM D-1003 Slippery: Coefficient of friction (static) Compliant with ASTM D-1894 Blocking resistance: Opening of film obtained by inflation film processing Open the part by hand and evaluate the easiness of peeling. ○: Easy △: Slightly difficult ×: Difficult Tensile strength: According to ASTM D-882 Average molecular weight: Dissolve completely the polycarbonate sample in methylene chloride and use a viscosity tube The number of seconds of the solution falling at 20 ° C. was measured and the intrinsic viscosity “η”
The average molecular weight is determined by the formula of l).

Example 1 Silica having an average particle diameter of 1.4 μm (specific surface area: 300 m ^{2 /} g) 0.05 per 100 parts by weight of polycarbonate having an average molecular weight of 25,500
After adding and mixing 0.1 parts by weight of beeswax and beeswax, the mixture was pelletized by a granulator, and then subjected to inflation film processing at a resin temperature of 290 ° C. to obtain a 20 μm thick film.

Example 2 Silica having an average particle size of 1.4 μm (specific surface area: 300 m ^{2 /} g) was added to 100 parts by weight of polycarbonate having an average molecular weight of 25,500.
Parts by weight and 0.2 parts by weight of beeswax were added and mixed, and pelletized by a granulator, followed by inflation film processing at a resin temperature of 290 ° C. to form a 20 μm thick film.

Example 3 Silica having an average particle size of 1.8 μm (specific surface area: 300 m ^{2 /} g) per 100 parts by weight of polycarbonate having an average molecular weight of 21,500 was 0.05
Parts by weight, pentaerythritol tetrastearate 0.2
After adding and mixing parts by weight and pelletizing with a granulator, an inflation film process was performed at a resin temperature of 270 ° C. to obtain a film having a thickness of 20 μm.

Example 4 Silica having an average particle size of 1.4 μm (specific surface area: 300 m ^{2 /} g) per 100 parts by weight of polycarbonate having an average molecular weight of 26,500 was 0.05
After adding and mixing 0.1 parts by weight of beeswax and 0.1 part by weight of beeswax, pelletized by a granulator, T-die extrusion was performed at a resin temperature of 290 ° C. to form a film having a thickness of 100 μm.

Comparative Example 1 Silica having an average particle diameter of 1.4 μm (specific surface area: 300 m ^{2 /} g) 0.05 per 100 parts by weight of polycarbonate having an average molecular weight of 25,500
After adding and mixing parts by weight and pelletizing with a granulator, an inflation film processing was performed at a resin temperature of 290 ° C. to obtain a film having a thickness of 20 μm.

Comparative Example 2 Silica having an average particle size of 12 μm (specific surface area: 300 m ^{2 /} g) was added to 100 parts by weight of a polycarbonate having an average molecular weight of 25,500.
After adding and mixing 0.1 parts by weight of beeswax and beeswax, the mixture was pelletized by a granulator, and then subjected to inflation film processing at a resin temperature of 290 ° C. to obtain a 20 μm thick film.

Comparative Example 3 0.1 part by weight of beeswax was added to and mixed with 100 parts by weight of a polycarbonate having an average molecular weight of 25,500, and pelletized by a granulator. Then, an inflation film was processed at a resin temperature of 290 ° C. to form a film having a thickness of 20 μ. .

Comparative Example 4 Polycarbonate having an average molecular weight of 25,500 was pelletized by a granulator, and then subjected to inflation film processing at a resin temperature of 290 ° C. to obtain a 20 μm thick film.

 Table 1 shows the film properties.

(Effect of the Invention) The polycarbonate composition of the present invention provides a film having excellent slipperiness, blocking resistance, and transparency as compared with conventional compositions, and also improves productivity in film processing. Is.

Claims (1)

(57) [Claims] (1) 0.001 to 1 part by weight of finely divided silica having an average particle diameter of 3 μm or less per 100 parts by weight of a 2,2-bis (4′-hydroxyphenyl) propane-based polycarbonate having a viscosity average molecular weight of 15,000 or more; The transparency is obtained by blending 0.005 to 5 parts by weight of an ester or a partial ester of an aliphatic saturated monohydric carboxylic acid having 10 to 30 carbon atoms and an aliphatic saturated monohydric alcohol or a polyhydric alcohol having 30 or less carbon atoms. A polycarbonate resin composition which is good and has excellent slipperiness and blocking resistance.