JPH08176377A - Flame-retardant resin composition - Google Patents

Abstract

PURPOSE: To obtain a flame-retardant resin composition suitable for injection molding, providing a molded article having excellent impact resistance and external appearance, by adding a specific amount of an ethylene/carbon monoxide/(meth)acrylate copolymer to a vinyl chloride-based flame-retardant resin. CONSTITUTION: This flame-retardant resin composition is obtained by blending (A) 100 pts.wt. of a vinyl chloride-based flame-retardant resin composed of (i) 30-80wt.% of a styrenic resin having 0.20-0.55dl/g viscosity of a methyl ethyl ketone soluble part (N,N-dimethylformamide solution, 30 deg.C, c=0.3g/dl) and (ii) 70-20wt.% of a vinyl chloride-based resin having 400-800 average degree of polymerization with (B) 0.5-10 pts.wt. of an ethylene/carbon monoxide/(meth) acrylate copolymer having 30-90wt.% of ethylene residue, 1-40wt.% of carbon monoxide residue and 5-60wt.% of (meth)acrylic acid alkyl ester residue, is suitable for injection molding and provides a molded article having excellent impact resistance and excellent external appearance.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant resin composition, and more specifically, the appearance of a molded product is good,
The present invention also relates to a flame-retardant resin composition having excellent impact resistance, heat distortion resistance and molding processability, which is particularly suitable for injection molding.

[0002]

2. Description of the Related Art Flame-retardant resins for injection molding, which are composed of a low molecular weight styrene resin and a low polymerization degree vinyl chloride resin, are excellent materials in view of their mechanical properties and economical efficiency.
The use as a housing material for equipment A is increasing.
However, this material has a drawback that a molded product is liable to be burned or flashed, and that the molding process is difficult. This is because, especially because it contains vinyl chloride resin, the melt viscosity of the resin during injection molding is high and the fluidity is low, and as a result, the shear heat generation of the metal and resin such as the screw, cylinder, and mold becomes large. It is considered that thermal decomposition may occur, causing burns, flashes, etc. on the molded product. As a method for improving these, it is general to add a large amount of a stabilizer or a lubricant. However, these methods are not ones that satisfy the requirements such as a decrease in impact resistance or an additive added at the time of molding to become a mold deposit and a decrease in productivity, a decrease in balance of physical properties and a poor appearance of a molded product. There wasn't.

[0003]

SUMMARY OF THE INVENTION It is an object of the present invention to obtain a flame-retardant resin composition which gives good appearance of a molded product and is excellent in impact resistance and molding processability balance.

[0004]

That is, the present invention provides (A)
A flame-retardant resin composition obtained by adding 0.5 to 10 parts by weight of (B) ethylene / carbon monoxide / (meth) acrylic acid ester copolymer to 100 parts by weight of a vinyl chloride flame-retardant resin. It is the content.

The vinyl chloride type flame-retardant resin (A) in the present invention has, for example, a reduced viscosity of a methyl ethyl ketone soluble part of 0.20 to 0.55 dl / g (N, N-dimethylformamide solution, 30 ° C., C = 0.3 g / dl) Styrene resin (A1) 30 to 80% by weight and vinyl chloride resin (A2) 7 having an average degree of polymerization of 400 to 800
Those composed of 0 to 20% by weight are preferably used.

(A) The styrene resin (A1) in the vinyl chloride flame-retardant resin has a reduced viscosity in the methyl ethyl ketone-soluble portion of C in an N, N-dimethylformamide solution.
= 0.3 g / dl, 0.20 to 0.55 dl at 30 ° C
/ G is preferable. If the reduced viscosity of the methyl ethyl ketone soluble part is less than 0.20 dl / g, the impact resistance will decrease,
When it exceeds 0.55 dl / g, the fluidity is lowered and the thermal stability during molding is deteriorated. Examples of such a styrene resin (A1) are ABS resin, AS resin, MBS resin, MABS resin, acrylonitrile-butadiene-styrene-α-methylstyrene copolymer, acrylonitrile-methylmethacrylate-butadiene-styrene-α.
Vinyl chloride resins such as methylstyrene copolymer, acrylonitrile-butadiene-styrene-α-methylstyrene-maleimide copolymer, AAS resin, AES resin, styrene-maleic anhydride copolymer, styrene-maleimide copolymer It includes all of the usual styrene resins having good compatibility with, and these are used alone or in combination of two or more kinds.

The amount of the styrene resin (A1) is 30 to 80% by weight, preferably 35 to 75% by weight in the flame-retardant resin (A). Styrene resin (A1) is 8 in component (A)
When it exceeds 0% by weight, impact strength is remarkably reduced, while 3
If it is less than 0% by weight, the proportion of the vinyl chloride resin (A2) becomes relatively large, which causes deterioration of processability.

The vinyl chloride resin (A2) in the (A) vinyl chloride flame retardant resin preferably has an average degree of polymerization of 4
00-800, more preferably 450-750,
Included are vinyl chloride homopolymers and / or copolymers in which at least 80% by weight or more is vinyl chloride, and post-chlorinated polyvinyl chloride. The copolymer may contain one or more monovinylidene compounds such as ethylene, vinyl acetate, methyl methacrylate, and butyl acrylate as a copolymerization component in an amount of less than 20% by weight. If the average degree of polymerization is less than 400, the impact strength will decrease, while if it exceeds 800, the fluidity will decrease significantly. The amount of the vinyl chloride resin (A2) in the component (A) is preferably 70-2.
It is 0% by weight, and more preferably 65 to 25% by weight.

(A) It is added to a vinyl chloride flame-retardant resin in order to improve the molding processability and to provide a molded article having good appearance and excellent impact resistance (B). ) Ethylene / carbon monoxide / (meth) acrylic acid ester copolymer is ethylene / carbon monoxide / (meth) acrylic acid ester copolymer, and the alkyl group of the (meth) acrylic acid alkyl ester is a straight chain. -Like or branched, having 1 to 18 carbon atoms, methyl group, ethyl group, n-propyl group, isopropyl group, n-
Examples thereof include a butyl group, a sec-butyl group, a t-butyl group, an isobutyl group, a hexyl group, a 2ethyl-hexyl group and an octyl group, and among them, those having 2 to 8 carbon atoms are more preferable. Those having more than 18 carbon atoms are not preferable in terms of economy.

The composition of the (B) ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer used in the present invention has an ethylene residue of preferably 30 to 90% by weight, more preferably 40 to 80% by weight. %, Carbon monoxide residue is preferably 1 to 40% by weight, more preferably 5 to 30
% By weight, the composition of the (meth) acrylic acid alkyl ester residue is preferably 5 to 60% by weight, more preferably 20 to 50% by weight (100% by weight in combination of the three), and if necessary, other It is also possible to copolymerize the compounds. Ethylene / carbon monoxide / (meth) with such composition
Examples of the acrylic acid alkyl ester copolymer include “Elvalloy HP441 (registered trademark: manufactured by Mitsui DuPont Chemical Co., Ltd.)”. Ingredient (B)
If the composition is out of the above range, the effect of improving impact resistance and molding processability is small, the thermal deformation resistance is largely reduced, and further peeling of the molded product is not preferable, which is not preferable.

The (B) ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer has a melt index (190 ° C., 2.16 Kg / cm ² ) of preferably 1 to 1000 g / 10 min. Preferably 5 to 200
g / 10 minutes. Regarding the method for producing the (B) ethylene / carbon monoxide / (meth) acrylic acid alkyl ester copolymer used in the present invention, see JP-A-4-125.
5, the method described in JP-A No. 4-1256, 4-1257, and the like.

The amount of component (B) used is 100 parts of component (A).
0.5 to 10 parts by weight, preferably 1 to 5 parts by weight
Parts by weight. If it is less than 0.5 parts by weight, the effect cannot be sufficiently exhibited, and if it exceeds 10 parts by weight, the peeling resistance of the molded product and the impact strength are largely lowered. The component (A) and the component (B) in the present invention are synthesized by a known method.

The flame-retardant resin composition of the present invention contains not only antioxidants, heat stabilizers and lubricants that are generally well known, but also UV absorbers, pigments, antistatic agents and flame retardants as required. The flame retardant aids may be used alone or in combination of two or more. In particular, phenolic antioxidants, phosphite stabilizers, thioether antioxidants used in styrene resins, tin stabilizers, lead stabilizers and various fatty acid esters, metal soaps that are blended with vinyl chloride resins. Inner lubricants, outer lubricants and the like are usually used to improve the performance of the composition of the present invention as a resin for injection molding. Further, the composition of the present invention, vinyl chloride-based resin effectively works and shows good flame retardancy, depending on the need for flame retardancy, further halogen-based flame retardants, flame retardant aids such as antimony compounds. It is also possible to mix and use.

Injection molding can be performed using pellets or powder. The pellets can be produced by an ordinary extruder, and the extrusion conditions may be any as long as the vinyl chloride resin is not deteriorated, and the screw shape, extrusion temperature, extrusion speed, etc. are not particularly limited. Regarding the injection molding conditions, a general injection molding machine can be used as long as the vinyl chloride resin is not deteriorated, and the screw shape, injection temperature, speed, pressure and the like are not particularly limited.

[0015]

EXAMPLES The present invention will be specifically described below based on Examples and Comparative Examples, but the present invention is not limited thereto.
In the following Examples and Comparative Examples, "parts" means "parts by weight" unless otherwise specified.

Examples 1 to 3 and Comparative Examples 1 to 3 (A1) Synthesis of Styrenic Resin Acrylonitrile 2 was polymerized by a known emulsion polymerization method.
A styrene resin having 5 parts, 75 parts of styrene and 20 parts of butadiene and having a reduced viscosity (ηsp / c) of 0.35 dl / g was obtained. (A2) Synthesis of vinyl chloride-based resin Polymerization was carried out by a known suspension polymerization method to obtain a vinyl chloride-based resin composed of 100 parts of vinyl chloride and having an average degree of polymerization of 600.

50 parts of the above styrene resin (A1),
50 parts of vinyl chloride resin (A2), 2 parts of dibutyltin malate as a tin stabilizer, 1 part of dibutyltin mercapto, 1 part of glycerin tristearate as a lubricant.
And 1 part of paraffin wax are used in common, and Table 1
Predetermined amount of (B) ethylene / carbon monoxide / (meta)
Acrylic ester copolymer "Elvalloy HP441
(Registered trademark, manufactured by Mitsui DuPont Chemical Co., Ltd.)
Pelletization was performed with a 0 mm extruder to obtain pellets of a flame-retardant resin composition for injection molding. Test pieces were prepared by injection molding using the pellets, and various physical properties were measured.
In addition, the appearance was evaluated by visually observing whether the appearance was good or bad and the presence or absence of flash.

The reduced viscosity of the styrene resin (A1) was measured as follows. The methyl ethyl ketone soluble component of the styrene resin was dissolved in N, N-dimethylformamide to a concentration of 0.3 g / dl to obtain a polymer solution,
According to JIS-K6721, the passage time (t) was measured at 30 ° C. using an Ubbelohde viscometer (capillary viscosity automatic meter side device manufactured by Shibayama Chemical Equipment Co., Ltd.). on the other hand,
Also for N, N-dimethylformamide as a solvent, the passage time (t _o ) was measured at 30 ° C. using the same device, and the reduced viscosity (η red) was calculated by the following formula. η red = (t / t-1) / C (In the formula, C means the concentration of the polymer solution.)

[0019]

[Table 1]

Izod impact value: (Kgcm / cm) ASTM
D-256, notched, 23 ° C heat distortion temperature: (° C) ASTM D-648, 1
8.6 Kg / cm ² load flexural modulus: (× 10 ² Kg / cm ² ) ASTM D
-636, 23 ° C MI (melt index): (g / 10 minutes) ASTM
D-1238, 190 ° C, 10 kg / cm ² load Drop weight strength: (Kg · m) length 150 mm, width 100
mm, thickness 3mmk flat plate, half breaking height x weight weight,
23 ° C

[0021]

INDUSTRIAL APPLICABILITY The flame-retardant resin composition of the present invention is particularly suitable for injection molding, provides a molded article having good appearance and excellent impact resistance, and has good molding processability.

Claims (3)

[Claims] 1. Addition of 0.5 to 10 parts by weight of (B) ethylene / carbon monoxide / (meth) acrylic acid ester copolymer to 100 parts by weight of (A) vinyl chloride flame-retardant resin. Flame-retardant resin composition. 2. The vinyl chloride flame-retardant resin (A) has a reduced viscosity of 0.20 to 0.55 in the methyl ethyl ketone soluble portion.
dl / g (N, N-dimethylformamide solution, 30
C, C = 0.3 g / dl) Styrenic resin (A
1) 30 to 80% by weight and an average degree of polymerization of 400 to 800
The flame-retardant resin composition according to claim 1, which comprises 70 to 20% by weight of the vinyl chloride resin (A2). 3. (B) Ethylene / carbon monoxide / (meth)
The acrylic ester copolymer has an ethylene residue of 30 to 9
The flame-retardant resin composition according to claim 1 or 2, comprising 0% by weight, carbon monoxide residues of 1 to 40% by weight, and (meth) acrylic acid alkyl ester residues of 5 to 60% by weight.