JP2588429B2 - Polycarbonate resin composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a polycarbonate resin composition, and more particularly, to a polycarbonate resin composition having improved flame retardancy without impairing the characteristics of the polycarbonate resin itself.

[Related Art and Problems to be Solved by the Invention] In order to improve the flame retardancy of polycarbonate, which is conventionally known as a molding resin having excellent mechanical properties such as rigidity and impact resistance and transparency. As a method for improving the resin itself, there are a method of copolymerizing with a comonomer mainly containing halogen, and a method of adding a halogen-based flame retardant to a polycarbonate resin.

However, these methods have a problem that hydrogen halide is generated at the time of molding to cause corrosion of a mold, and a molded article contains halogen, so that weather resistance is poor. Further, when the halogen-based flame retardant is added, the excellent properties of the polycarbonate resin may be impaired.

 The present invention has been made based on the above circumstances.

That is, the object of the present invention is to maintain the transparency and mechanical properties of the polycarbonate resin itself without impairing it, and without causing corrosion of the mold during molding.
An object of the present invention is to provide a polycarbonate resin composition that can be formed into a molded article having excellent weather resistance.

[Means for Solving the Problems] To achieve the above object, the present invention provides 99.8 to 90% by weight of a polycarbonate resin represented by the following general formula: [However, R ¹ and R ² each represent an alkyl group having 1 to 4 carbon atoms, and R ¹ and R ² may be the same or different. ] The alkylphosphonic acid ester represented by 0.2 to 10
% By weight of the polycarbonate resin composition.

 Hereinafter, the present invention will be described in detail.

-Polycarbonate resin- The polycarbonate resin used in the present invention has the following general formula (I) Wherein Z is a single bond or an alkylene group having 1 to 8 carbon atoms, an alkylidene group having 2 to 8 carbon atoms,
15 cycloalkylene groups, cycloalkylidene group having 5 to 15 carbon _{atoms, -SO 2 -, - SO -} , - O -, - CO- or R represents a hydrogen, chlorine or bromine atom or 1
Represents a saturated alkyl group having up to 8 carbon atoms,
Represents a number from 0 to 4. Further, Rs bonded to two benzene nuclei in the general formula may be the same or different from each other. The polycarbonate resin is prepared by a solvent method, that is, a reaction between a dihydric phenol and a carbonate precursor such as phosgene in a solvent such as methylene chloride in the presence of a known acid acceptor and a molecular weight modifier, or It can be produced by a transesterification reaction between knols and a carbonate precursor such as diphenyl carbonate.

Here, the dihydric phenols that can be suitably used include bisphenols, and 2,2-bis (4-hydroxyphenyl) propane (bisphenol A) is particularly preferable.

Further, bisphenol A may be partially or entirely replaced with another dihydric phenol.

As dihydric phenols other than bisphenol A,
For example, hydroquinone, 4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) alkane, bis (4-hydroxyphenyl) cycloalkane, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone, Bis (4-hydroxyphenyl) sulfoxide, bis (4-hydroxyphenyl) ether, etc., or bis (3,5-dibromo-4-
Halogenated bisphenols such as (hydroxyphenyl) propane and bis (3,5-dichloro-4-hydroxyphenyl) propane can be exemplified.

These dihydric phenols may be homopolymers or copolymers or blends of two or more dihydric phenols.

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 phenol and / or a carbonate precursor.

The polycarbonate resin used in the present invention has a viscosity average molecular weight of 1 in terms of mechanical strength and formability.
It is preferably from 0,000 to 100,000, especially from 20,000 to 40,0
Preferably it is 00.

The polycarbonate resin composition of the present invention contains the above-mentioned polycarbonate resin in an amount of 99.8 to 90% by weight, preferably 99.5 to 95% by weight, based on the total amount of the polycarbonate resin and the alkylphosphonate.

When the compounding amount of the polycarbonate resin exceeds 99.8% by weight, the compounding amount of the alkyl phosphonate becomes relatively small, so that there is no flame retardant effect, and the compounding amount is reduced.
When the content is less than 90% by weight, the amount of the alkyl phosphonate increases, and the physical properties such as the mechanical properties of the polycarbonate resin composition are significantly reduced. -Alkyl phosphonate- The alkyl phosphonate in the present invention Is
The following general formula (II) [However, R ¹ and R ² each represent an alkyl group having 1 to 4 carbon atoms, and R ¹ and R ² may be the same or different. ] Can be represented by

Here, an alkylphosphinic ester in which R ¹ or R ² in the above general formula is an alkyl group having 5 or more carbon atoms is not preferred because compatibility with the polycarbonate resin may be reduced.

Preferred as R ¹ and R ² are a methyl group and an ethyl group.

The alkylphosphonic acid ester represented by the general formula (II) can be produced by esterifying a trimethylol compound with an alkylphosphonic acid chloride as a phosphorylating agent.

-Other optional components-The polycarbonate resin composition of the present invention may contain various inorganic fillers, additives, or other synthetic resins, elastomers, and the like, if necessary, as long as the object of the present invention is not impaired. it can.

Examples of the inorganic filler compounded for the purpose of increasing the mechanical strength, durability, or weight of the polycarbonate resin composition include, for example, glass fiber, glass beads, glass flakes, carbon black, calcium sulfate, calcium carbonate, calcium silicate, Examples include titanium, alumina, silica, asbestos, talc, clay, mica, and quartz powder.

Examples of the additives include phosphorous acid-based and phosphate ester-based antioxidants, such as benzothiazole-based and benzophenone-based ultraviolet absorbers, such as aliphatic carboxylic acid ester-based and paraffin-based external lubricants, and common additives. Flame retardants, release agents, antistatic agents, coloring agents and the like.

Examples of other synthetic resins include resins such as polyethylene, polypropylene, polystyrene, AS resin, ABS resin, and polymethyl methacrylate. Examples of the elastomer include isobutylene-isoprene rubber, styrene-butadiene rubber, ethylene-propylene rubber, and acrylic elastomer.

These optional components are blended in appropriate amounts depending on the purpose.

—Production of Polycarbonate Resin Composition— The polycarbonate resin composition of the present invention can be produced by blending and kneading the above components at a predetermined ratio.

The compounding and kneading can be performed by a usual method, for example, using 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 and the like. be able to.

A suitable heating temperature for kneading is usually from 260 to 320 ° C.

 An example of a particularly preferred production method is as follows.

That is, the polycarbonate resin and the alkylphosphonate are uniformly dispersed and compounded by a super mixer, and then the resin temperature is reduced using a vented single screw extruder.
Melt and knead while heating to 260-320 ° C.

The polycarbonate resin composition thus obtained can be molded by various known molding methods, for example, injection molding, extrusion molding, calender molding, rotational molding, etc., into molded articles in the automotive field such as automobile bumpers and home appliances. It can be molded into molded articles in fields and the like.

[Example] Next, the present invention will be described more specifically with reference to examples of the present invention. However, the present invention is not limited to the following examples.

(Examples 1 and 2 and Comparative Examples 1 and 2) The polycarbonate resin (PC resin) and the alkylphosphonate (R ¹ = ethyl group, R ²
= Methyl group) in a mixing ratio shown in Table 1 using a super mixer.

This blend was fed to a single screw extruder and the resin temperature was raised to 260
The mixture was kneaded at a temperature of 300 ° C. to form a pellet.

The obtained pellets were further formed into test pieces, and the following tests were performed.

 The results are shown in Table 1.

Test method Tensile strength: conforms to JIS K7113 Tensile elongation: conforms to JIS K7113 Flexural modulus conforms to JIS K7203 Izod impact strength (with notch, 23 ° C) JIS K7110
Conforms to heat distortion temperature ・ ・ Conforms to JIS K7207, 18.6kg / cm ² Flame retardant ・ ・ ・ ・ UL-94 (1/8 ″) Transparency ・ ・ ・ ・ Specimen 3mm thick according to ASTM D1003 Was measured for total light transmittance.

[Effects of the Invention] According to the present invention, a polycarbonate resin composition having improved flame retardancy can be provided without impairing mechanical properties such as transparency and impact resistance of the polycarbonate resin itself.

Claims (1)

(57) [Claims] (1) 99.8 to 90% by weight of a polycarbonate resin having the following general formula [However, R ¹ and R ² each represent an alkyl group having 1 to 4 carbon atoms, and R ¹ and R ² may be the same or different. ] The alkylphosphonic acid ester represented by 0.2 to 10
% By weight of the polycarbonate resin composition.