JPH06263962A - Resin composition having excellent thermal stability and property to hardly corroding mold used therefor - Google Patents

Abstract

PURPOSE:To obtain a resin composition useful for automotive parts, precision machines, etc., having excellent physical properties, etc., comprising a polycarbonate resin and an ABS resin as a specific copolymer as essential components. CONSTITUTION:This resin composition comprises (A) 95-5wt.% of a polycarbonate resin [preferably 85-15wt.% of 2,2-bis(4-oxyphenyl)alkane-based polycarbonate having >=1,800 viscosity average molecular weight] and (B) 5-95wt.% (preferably 15-85wt.%) of an ABS resin having an alkali metal index of formula I of <=1, an alkaline earth metal index of formula II of <=30 and 500ppm chlorine content obtained by copolymerizing 10-200 pts.wt. of one or more monomers selected from styrene and acrylonitrile with 0-50 pts.wt. of a copolymerizable monomer such as methyl vinyl ether in the presence of 100 pts.wt. of a conjugated diene- containing elastomer (e.g. polybutadiene or natural rubber) as essential components and optionally 0.02-2.0 pts.wt. of a stabilizer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is a resin composition containing a polycarbonate resin and an ABS resin as essential components, and while maintaining its excellent physical properties, it has thermal stability during residence and mold corrosion characteristics. An improved composition.

[0002]

2. Description of the Related Art Polycarbonate resins are used in a wide range of fields such as automobile parts, electric / electronic machine parts and precision machine parts because they are excellent in heat resistance and impact resistance.
It is expensive and has disadvantages such as poor moldability and low impact resistance at low temperatures. On the other hand, ABS resin (acrylonitrile-butadiene-styrene copolymer) has a high mechanical strength,
Although it is an inexpensive material with excellent moldability, it has insufficient heat resistance and impact resistance for use in parts such as automobile parts and OA parts that require high heat resistance and high impact resistance. Are limited.

As a method of compensating for these mutual defects,
A method for producing a resin composition composed of a polycarbonate resin and an ABS resin is known. This method improves the moldability, which was a disadvantage of the polycarbonate resin, and the impact resistance at low temperatures, and also improves the heat resistance, which was a disadvantage of the ABS resin, and the insufficient impact resistance. However, as a new problem, a problem that the thermal stability at the time of retention is lowered has appeared. As a method for improving the thermal stability of the resin composition during retention, a method of adding one or more acid compounds selected from inorganic acids, organic acids and organic acid anhydrides (JP-A-56-131657), organic A method of containing phosphonic acid or a phosphoric acid ester metal salt (JP-A-55-123647,
JP-A-54-40854) and the like are disclosed.

[0004]

[Problems to be Solved by the Invention] By these methods,
Certainly, the thermal stability during retention has been improved, but along with this improvement, it is increasingly used in large moldings and thin moldings that have not been molded in the past. When molding large moldings or thin moldings that are difficult to mold, the molding conditions are stricter with respect to the resin, such as when the molding temperature is set higher than before and a large injection molding machine is used. As a result, the residence time of the resin at the time of molding becomes long, and the problem that appearance defects such as flash are likely to occur reoccurs, and the problem of mold corrosion is becoming more prominent.

Therefore, the present inventor has conducted diligent studies to improve these problems, and as a result, polycarbonate resin and AB
It does not impair the heat resistance and impact resistance of the resin composition containing S resin as an essential component, and further exceeds the conventionally improved quality to further improve the thermal stability at the time of residence and also to prevent mold corrosion. The present invention has been accomplished by finding a resin composition having improved properties.

[0006]

That is, according to the present invention, in a resin composition containing a polycarbonate resin and an ABS resin as essential components, the ABS resin has an alkali metal index defined by the formula 1 of 1 or less, and defined by the formula 2. The thermoplastic resin composition has an alkaline earth metal index of 30 or less and a chlorine content of 500 ppm or less.

[Equation 3]

[Equation 4] In the above formulas 1 and 2, 23, 39, 24,
The numerical value of 40 is each atomic weight of sodium, potassium, magnesium and calcium, 0.95, 1.33,
The numerical values of 0.65 and 0.99 are the ionic radii of sodium, potassium, magnesium and calcium (unit is Å)
Represents

The present invention will be described in more detail below. Examples of the polycarbonate resin in the present invention include aromatic polycarbonates, aliphatic polycarbonates, aliphatic-aromatic polycarbonates, and the like, preferably 2,2-bis (4-oxyphenyl) alkane-based,
Bisphenol such as bis (4-oxyphenyl) ether type, bis (4-oxyphenyl) sulfone type, 9,9-bis (4-hydroxyphenyl) fluorenone type, isophorone type and the like, alkylated derivatives thereof, nuclear halogenation One or more homo- and copolycarbonates selected from derivatives. These polycarbonate resins are
Viscosity average molecular weight is 15,000 or more, preferably 1800
It is 0 or more.

The ABS resin in the present invention means an aromatic vinyl monomer such as styrene, α-methylstyrene, a halogen- or alkyl-substituted nucleus-substituted styrene in the presence of 100 parts by weight of a conjugated diene-containing elastomer, acrylonitrile, Selected from the group consisting of vinyl cyanide monomers such as methacrylonitrile and fumaronitrile and unsaturated carboxylic acid alkyl ester monomers such as methyl methacrylate, cyclohexyl methacrylate, methyl acrylate, butyl acrylate and dimethyl fumarate. Copolymerized with 10 to 200 parts by weight of two or more kinds of monomers and 0 to 50 parts by weight of other copolymerizable monomers such as methyl vinyl ether, maleimide, N-phenylmaleimide as necessary. It is a copolymer.

As the conjugated diene-containing elastomer in the ABS resin, polybutadiene, polyisoprene, natural rubber, butadiene-styrene copolymer, butadiene-acrylonitrile copolymer, chloroprene polymer, isoprene-styrene copolymer, acrylic acid alkly Examples include ruble butadiene copolymers and partially hydrogenated products of these copolymers, and one or more homopolymers or copolymers can be used.

The ABS resin is usually produced by an emulsion graft polymerization method and tends to have a large residual amount of an emulsifier and a latex precipitant. In order to make the amount of impurities such as alkali metal, alkaline earth metal, and halide defined in the above formulas 1 and 2 within a predetermined range, the type and amount of the latex depositing agent and washing of the depositing agent are required. It is to optimize the conditions. It is preferable to avoid precipitation only with an alkali metal salt, and to use a precipitation agent composition in which the proportion of halogen compound used is small. Specifically, a combined use agent of magnesium sulfate and sulfuric acid is preferable. The allowable amount of impurities remaining is that the alkali metal index is 1 or less,
It is preferably 0.8 or less, particularly preferably 0.5 or less, and the alkaline earth metal index is 30 or less, preferably 25.
It is preferably 20 or less, particularly preferably 20 or less. Furthermore, chlorine amount is 5
The amount is 00 ppm or less, preferably 400 ppm or less, and particularly preferably 300 ppm or less.

In any case where the alkali metal index remaining in the ABS resin exceeds 1, or the alkaline earth metal index exceeds 30, even if a stabilizer is added, the thermal stability at the time of retention is improved. Further improvement becomes difficult. Further, if the amount of chlorine exceeds 500 ppm, the effect of improving the mold corrosion resistance will be poor even if an additive is added.

The alkali metals remaining in the ABS resin are mainly sodium and potassium, and the residual amounts of lithium, rubidium, cesium, and flangeum are very small. Therefore, in the present invention, sodium and potassium are used as the alkali metals. Limit the amount of potassium remaining. Similarly, the alkaline earth metals remaining in the ABS resin are mostly magnesium and calcium, beryllium,
Since strontium, barium, radium, etc. are present in minute amounts, the present invention limits the alkaline earth metals to magnesium and calcium.

These alkali metals, alkaline earth metals and chlorine contained in the resin composition can be quantified by a known analysis method. For example, quantitative determination of potassium, calcium and chlorine can be performed by energy dispersive or wavelength dispersive X-ray spectroscopy, and quantitative determination of sodium and magnesium can be performed by ashing and then atomic absorption spectrometry.

In the present invention, the ratio of the polycarbonate resin to the ABS resin is set to various mixing ratios in consideration of the intended use of the molded product, product rigidity, impact strength, heat resistance, price, moldability and the like. However, the polycarbonate resin is 95 to 5% by weight, preferably 90 to 10% by weight, particularly preferably 85 to 15% by weight, the ABS resin is 5 to 95% by weight, preferably 10 to 90% by weight, particularly preferably 15% by weight.
~ 85% by weight. The ratio of polycarbonate resin is 5
If it is less than 95% by weight, the effect of improving heat resistance and impact resistance is poor, and if it exceeds 95% by weight, moldability and hot water resistance tend to decrease.

Further, the other thermoplastic resin is 0 to 100 parts by weight, preferably 0 to 70 parts by weight, particularly preferably 0 to 50 per 100 parts by weight of the total amount of the polycarbonate resin and the ABS resin which are essential components in the present invention. Parts by weight can be used in combination. If the amount of the other thermoplastic resin that can be used in combination exceeds 100 parts by weight, at least one of the physical properties such as heat resistance, impact resistance and moldability is impaired.

In the present invention, examples of other thermoplastic resins which can be used in combination include aromatic vinyl monomers such as styrene, α-methylstyrene, halogen- or alkyl-substituted nucleus-substituted styrene, acrylonitrile and methacrylonitrile. , Vinyl cyanide monomers such as fumaronitrile and methyl methacrylate, cyclohexyl methacrylate, unsaturated carboxylic acid ester monomers such as dimethyl fumarate, maleic anhydride, unsaturated dicarboxylic acids such as itaconic acid (anhydride), Homopolymers and / or copolymers of one or more monomers selected from the group consisting of unsaturated dicarboxylic acid imide compounds such as maleimide, N-methylmaleimide and N-phenylmaleimide, and vinyl ether compounds such as methyl vinyl ether. , AAS resin (acrylonitrile-acrylic rubber Styrene copolymer), AES (acrylonitrile-ethylene-propylene-diene elastomer-styrene copolymer), polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycyclohexane dimethylene terephthalate, bisphenol A and phthalic acid Aromatic polyester resin such as a condensate with 6-nylon, 66-nylon, 46-nylon, MXD6 nylon, 6/10 nylon, 12 nylon, 6T nylon, polyamide resin such as 6 / 6T nylon, polyphenylene resin, Polyethylene, polypropylene, poly-4
-Polyolefin resins such as methylpentene, syndiotactic polystyrene and the like can be mentioned.

Among the above-mentioned thermoplastic resins which can be used in combination, weather resistance is improved by using AAS resin or AES resin together, and addition of styrene-maleic anhydride-N-phenylmaleimide copolymer improves heat resistance. In addition, when a proper amount of polybutylene terephthalate or polyethylene terephthalate is used together, weld strength and moldability can be further improved while maintaining heat resistance and impact resistance.

Of course, in the resin composition of the present invention, inorganic phosphoric acid such as phosphorous acid and phosphoric acid as a stabilizer, benzenephosphonic acid, ethylphosphonic acid, octyl acid phosphate, dioctyl phosphate, dibutyl. Hydrogen phosphite, pentaerythritol diphosphite compound, triphenylphosphine, triphenylphosphine oxide, tributylphosphine oxide, triphenylphosphate, dibutyl
Butyl phosphate, tetrakis (2,4-di-t-
Butylphenyl) -4,4-biphenylene phosphonite, organophosphorus compounds such as trilauryl thiophosphite, terephthalic acid, cyclopentane tetracarboxylic acid,
Organic carboxylic acids such as trimellitic acid, transanitic acid, β, β'-dithiocarboxylic acid, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, diphenic anhydride,
Cyclopentanecarboxylic anhydride, norbornene anhydride
2,3-dicarboxylic acid, methylendomethylenetetrahydrophthalic anhydride, a low molecular weight copolymer of styrene and maleic anhydride, an acid anhydride such as a maleic anhydride modified product of low molecular weight polypropylene, pentaerythrityl tetrakis (3 -(3,5-Di-t-butyl-4-hydroxyphenyl) propionate, octadecyl-3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionate, 3,5-di-t-butyl-4-hydroxy-benzylphosphonate-diethyl ester, 2-t-butyl-6- (3-t-butyl- Hindered phenol compounds such as 2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2,2-methylenebis ((1,1,3,3-tetramethylbutyl) -4- (2
H-benzotriazol-2-yl) phenol), 2
-(5-Methyl-2-hydroxyphenyl) benzotriazole, 2- (2-hydroxy-3,5-bis (α,
α-dimethylbenzyl) phenol) -2H-benzotriazole, 2- (3,5-di-t-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, 2
Benzotriazole derivatives such as-(3,5-di-t-amyl-2-hydroxyphenyl) benzotriazole, bis (2,2,6,6-tetramethyl-4-piperdyl) sebacate, bis (1,2,2) 2,6,6-Pentamethyl-4-piperidyl) sebacate, dimethyl succinate 1- (2-hydroxyethyl) -4-hydroxy-
2,2,6,6-tetramethylpiperidine polycondensate, 1
-(2- (3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy) ethyl) -4-
(3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy) -2,2,6,6-tetramethylpiperidine and other hindered amine compounds, polymeric hindered amine compounds, 2-hydroxy-4 −
Benzophenone compounds such as n-octoxybenzophenone, salicylate compounds, cyanoacrylate compounds and the like can be added.

Of course, these additives may be used in combination of two or more. The amount of these additives to be added is 0 to 5.0 parts by weight, preferably 0.01 to 3.0 parts by weight, and particularly preferably 100 parts by weight of the resin component containing polycarbonate resin and ABS resin as essential components. Is 0.02-
2.0 parts by weight. If the amount is more than 5.0 parts by weight, heat resistance and mechanical properties will be deteriorated, and the stabilizer will bleed to the surface of the molded product.

Among the above stabilizers, phosphorus compounds, especially those of formula 3
When the pentaerythritol diphosphite-based compound represented by is added, the thermal stability during retention can be further improved. In the formula 3, R1 and R2 are preferably an aryl group or an aralkyl group, particularly a 2,6-di-t-butyl-4-methylphenyl group or a 2,6-di-t-butylphenyl group.

[0021]

[Chemical 1]

The resin composition of the present invention can be produced by melt-kneading with a kneading machine which is usually used, for example, Banbury mixer, kneader, kneading extruder, twin-screw extruder, etc., but preferably with a vent I use a twin screw extruder. The extrusion temperature during melt-kneading is not particularly limited, and the resin temperature should be selected according to the glass transition point and melting point of the raw material resin component. Particularly preferable resin temperature is 2
It is in the range of 30 ° C to 300 ° C.

In the resin composition of the present invention, if necessary, pigments, dyes, lubricants, crystal nucleating agents, antiblocking agents, release agents, plasticizers, silicone compounds, flame retardants, flame retardant aids, antistatic agents. Agents, coupling agents and glass fibers, whiskers,
A filler such as carbon fiber can be added. Of course, when adding these, alkali metal,
It is desirable to select and use varieties with low alkaline earth metal and chlorine contents.

[0024]

EXAMPLES AND COMPARATIVE EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited thereto. In addition, all parts described in the present specification are based on weight. Further, the measurement of physical properties in Examples and Comparative Examples was performed by the following methods. (1) Heat resistance (Vicat softening point): JIS K7206 (2) Melt flow index (hereinafter abbreviated as MFR): According to JIS K7210, temperature 250 ° C, load 5 kg (3) Appearance during retention: injection molding machine Sumitomo Nestal 75T
Molding temperature is set to 260 ° C, the resin is retained in the cylinder for 30 minutes, and a test piece of 55 × 90 × 2 mm is molded with a one-point gate, and the flash generation status is visually determined. did. ○… No flash △… Partially flashed ×… Flashed all over the plate (4) Izod impact strength during retention: injection molding machine Toshiba IS
Using -55EPN, setting the molding temperature to 280 ° C,
After the resin was retained in the cylinder for 2 minutes, a dumbbell bar was formed and cut out to obtain a test piece for Izod impact strength evaluation. (Thickness of test product is ⅛ inch, temperature is 23 ℃) (5) Corrosion resistance of mold: Metal piece of PDS3 made of Daido special steel widely used as steel for plastic molding mold (2
(0 × 30 × 2 mm) was hung from above, 20 parts of the resin composition was charged into a stainless steel autoclave devised so as to be immersed in the resin composition, and after nitrogen substitution, it was left in a gear oven at 250 ° C. for 4 hours. After cooling to room temperature, the autoclave was opened, the taken out metal piece was immersed and washed in a tetrahydrofuran solvent, and the state of corrosion was visually determined. A metal piece was almost equivalent to the state before the test. B: The metal piece is slightly discolored as compared with that before the test. × ... The discoloration of the metal piece is remarkable as compared with that before the test.

First, the stabilizers such as resins and phosphorus compounds used in the following Examples and Comparative Examples will be shown. (1) Production of ABS resin 80 parts of polybutadiene latex (average particle size 350 m
μ, solid content 50% by weight), ABS resin latex obtained by graft polymerization of 18 parts of acrylonitrile and 42 parts of styrene was precipitated, washed with water, filtered, and dried with an aqueous calcium chloride solution, and designated as ABS-1. . A powder obtained by precipitating the same ABS resin latex with an aqueous solution of magnesium sulfate, washing with water, filtering and drying was designated as ABS-2. Similarly, the molar ratio of sulfuric acid to magnesium sulfate is 1: 2, 1:
Powders obtained by precipitating with an aqueous solution of a precipitant of 1: 1: 1, washing with water, filtering, and drying are ABS-3, ABS-4, and
ABS-5. In the production of ABS-5,
The powder obtained by halving the amount of the washing water of the precipitate is ABS-
6 The molar ratio of hydrochloric acid to magnesium sulfate is 2: 1.
The powder obtained by precipitating with an aqueous solution of the precipitant, washing with water, filtering, and drying is referred to as ABS-7.

(2) Polycarbonate resin Iupilon E-2000 manufactured by Mitsubishi Gas Chemical Co., Inc., which is a bisphenol A type polycarbonate, was used. Less than,
Abbreviated as PC.

(3) Polybutylene terephthalate resin Novadur 5020 manufactured by Mitsubishi Kasei was used. Below, P
Abbreviated as BT

(4) Polyethylene terephthalate resin NEH2050 manufactured by Unitika was used. Hereinafter, it is abbreviated as PET.

(5) Styrene-maleic anhydride-N-phenylmaleimide copolymer (styrene 48.8%, maleic anhydride 3.8%, N-phenylmaleimide 47.
4%) or less, abbreviated as ST-MI.

(6) Phosphorus Compound Bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite Hereinafter, it is abbreviated as PEP-24G. Bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite or less, PEP
Abbreviated as -36. Trilauryltrithiophosphite Hereinafter, abbreviated as TLTP.

(7) Other stabilizers pentaerythrityl-tetrakis (3- (3,5-di-
t-Butyl-4-hydroxyphenyl) propionate) Hereinafter, it is abbreviated as Irganox.

Examples 1 to 11 and Comparative Examples 1 to 3 The formulations shown in Tables 1, 2 and 3 were charged in a Henschel mixer and mixed at low speed for 3 minutes. This mixture is melt-kneaded with a 35φ twin-screw extruder with a vent to produce pellets for physical property evaluation, and evaluated by the above-mentioned measurement method.
The measured results are shown in Tables 1, 2 and 3.

[0033]

[Table 1]

[0034]

[Table 2]

[0035]

[Table 3]

[0036]

EFFECTS OF THE INVENTION In a resin composition containing a polycarbonate resin and an ABS resin as essential components, the use of an ABS resin in which the amount of impurities in the ABS resin is an alkali metal index ≦ 1 and an alkaline earth metal index ≦ 30 It was possible to improve the appearance and impact resistance during retention. on the other hand,
It was possible to improve the mold corrosion characteristics by using an ABS resin having a chlorine content of 500 ppm or less. These alkali metal index ≦ 1, alkali metal index ≦
By using an ABS resin having a chlorine content of 30 and a chlorine content of 500 ppm or less, it was possible to achieve both thermal stability during residence and mold corrosion resistance.

Claims (1)

[Claims] 1. A resin composition comprising a polycarbonate resin and an ABS resin as essential components, wherein the ABS resin has the formula 1
A thermoplastic resin composition having an alkali metal index of 1 or less, an alkaline earth metal index of 30 or less, and a chlorine content of 500 ppm or less defined by Formula 2. [Equation 1] [Equation 2]