JPH10120863A - Flame-retardant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a highly flame-retardant resin composition without detriment to impact resistance and heat stability by mixing a high-impact polystyrene resin with a bromine-containing flame retardant, antimony trioxide and a combination of a specified SBR with a chlorinated polyethylene. SOLUTION: This composition is prepared by mixing 100 pts.wt. high-impact polystyrene resin (A) with 2-10 pts.wt. styrene/butadiene copolymer (B) having a butadiene content of 50-80wt.%, 10-30 pts.wt. bromine-containing flame retardant (C), 3-10 pts.wt. antimony trioxide (D) and 1-10 pts.wt. chlorinated polyethylene (E) prepared by chlorinating a polyethylene having a weight-average molecular weight of 200,000-800,000 and having a chlorine content of 5-20wt.% and kneading the resulting mixture. Component B is desirably a styrene/butadiene/ styrene triblock copolymer having good compatibility. Component C is exemplified by hexabromobenzene being a common flame retardant. Because the composition contains components E and B, it retains the properties of component A, does not drip during burning and can show flame retardancy which can pass UL-94V0 specified in U.S. UL specification.

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 particularly to molding of industrial or household materials requiring flame retardance, such as electrical equipment, OA equipment, and household kitchenware. And a flame-retardant resin composition to be used.

[0002]

2. Description of the Related Art An impact-resistant polystyrene resin (hereinafter referred to as HIP) widely used for molding electric equipment, OA equipment, automobile parts, household goods and the like.
S) is generally very flammable and has the drawback that if a flame is brought close to a part of the molded product and starts to burn, it will continue to burn naturally even if the flame is moved away. In recent years, requirements for flame retardancy have become severe due to the need for fire safety. In particular, electrical equipment and OA equipment are required to pass the UL (Underwriters Laboratory) UL-94V0 standard. Fields are expanding.
In order to pass the UL-94V0 standard, it is required that there is no dripping during combustion. Conventionally, as a method of making a styrene-based resin flame-retardant, it is known to mix a styrene-based resin with a flame retardant such as an organic bromine compound or a flame retardant auxiliary such as antimony trioxide. In this case, dripping cannot be prevented, so that it does not pass the UL-94V0 standard, and furthermore, a large amount of a flame retardant is mixed in, so that the excellent impact resistance of HIPS is significantly reduced. Was. As a method for preventing dripping, for example, a method in which an inorganic filler such as talc, clay, or glass fiber is mixed into the above-described composition, or polytetrafluoroethylene (for example,
0-44241), and a method of mixing a chlorinated polyethylene having a chlorine content of 25 to 50% by weight (for example, JP-A-50-94066).
Although dripping can be prevented, it is difficult to maintain the inherently excellent impact resistance of the impact-resistant polystyrene resin. Further, the method of mixing chlorinated polyethylene having a chlorine content of 25 to 50% by weight is not suitable for heat stability of HIPS. Therefore, the practical value was low because the property was also significantly reduced.
Further, Japanese Patent Application Laid-Open No. 54-68855 of the present applicant discloses that styrene-butadiene copolymer (hereinafter abbreviated as SBR) is added to chlorinated polyethylene having a chlorine content of 25 to 50% by weight.
Although the method of mixing HIPS has been proposed, even in this method, the impact resistance of HIPS can be maintained, but a decrease in thermal stability cannot be prevented.

[0003]

Means for Solving the Problems The present inventors have focused on these problems, and as a result of diligent research, have found that the weight-average molecular weight is 200,000 or less.
Chlorine content of 800,000 polyethylene chlorinated 5-20
By using chlorinated polyethylene in a weight percentage, dripping can be prevented without deteriorating thermal stability, and SB
The inventors have found that the impact resistance of HIPS can be maintained by using R together, and have reached the present invention. The present invention relates to (a) 100 parts by weight of an impact-resistant polystyrene resin, (b) 2 to 10 parts by weight of a styrene-butadiene copolymer having a butadiene content of 50 to 80% by weight, and (c) a bromine-based resin. 10 to 30 parts by weight of a fuel, (d) 3 to 10 parts by weight of antimony trioxide, and (e) a weight average molecular weight of 200,000 to 8
A flame-retardant resin composition comprising 1 to 10 parts by weight of chlorinated polyethylene having a chlorine content of 5 to 20% by weight obtained by chlorinating 100,000 polyethylenes.

[0004] When only SBR is blended with HIPS, the impact resistance can be improved but dripping cannot be prevented.
Further, even if the butadiene content in HIPS is increased, the tensile strength decreases, so that the combination of the anti-drip property and the excellent impact resistance is achieved only in the presence of the three components of HIPS, SBR and chlorinated polyethylene. The HIPS used in the present invention is mainly composed of a styrene-based polymer. In the presence of rubber-like substances such as polybutadiene, butadiene-styrene copolymer rubber, and ethylene-propylene diene copolymer rubber, styrene, α Graft copolymer obtained by polymerizing one or more styrene monomers such as methylstyrene, vinyltoluene, chlorostyrene, etc .; homopolymer or copolymer obtained by polymerizing the rubbery substance and the styrene monomer; It refers to a blend by post-mixing with a polymer. The SBR used in the present invention is preferably a styrene-butadiene copolymer having a butadiene content of 50 to 80% by weight. If the butadiene content exceeds 80% by weight, the compatibility with HIPS decreases and the physical properties of HIPS decrease, and if it is less than 50% by weight, sufficient impact resistance cannot be obtained. From the viewpoint of compatibility with HIPS, a styrene-butadiene-styrene triblock copolymer is more preferably used. About HI
The content is 2 to 10 parts by weight, more preferably 2 to 7 parts by weight, based on 100 parts by weight of PS.

As the brominated flame retardant of the present invention, those usually used can be used as they are. For example, decabromodiphenyl oxide, tetrabromobisphenol A, hexabromobenzene, brominated bisphenol carbonate oligomer, brominated epoxy And the like. The compounding amount of the flame retardant is 10 to 30 parts by weight of a brominated flame retardant and 3 to 10 parts by weight of antimony trioxide with respect to 100 parts by weight of HIPS. If the amount is less than the respective ranges, sufficient flame retardancy cannot be obtained. If the amount exceeds the range, the mechanical properties are remarkably deteriorated, and it is economically disadvantageous.

The chlorinated polyethylene used in the present invention is made of polyethylene having a weight average molecular weight of 200,000 to 800,000 and a chlorine content of 5 to 20% by weight, more preferably 7 to 13% by weight. good. When the weight average molecular weight of the raw material polyethylene is less than 200,000, both the drip resistance and impact resistance are insufficient, and when it exceeds 800,000, the moldability is deteriorated, which is not preferable. If the chlorine content is less than 5% by weight, the anti-drip property and the impact resistance are inferior.
If the amount is more than 10% by weight, the thermal stability is significantly reduced. The heat of fusion measured by differential scanning calorimetry (DSC) is 3 to 15.
Using cal / g chlorinated polyethylene, HIPS
The dispersibility of the chlorinated polyethylene therein is improved, and more excellent anti-drip properties are obtained. About HIPS
The amount is 1 to 10 parts by weight, more preferably 2 to 5 parts by weight, per 100 parts by weight. If the amount is less than 1 part by weight, sufficient anti-drip property cannot be obtained, and if it exceeds 10 parts by weight, tensile strength, moldability, and thermal stability decrease. There are two main methods for producing chlorinated polyethylene: a method of chlorinating polyethylene in a carbon tetrachloride solvent and a method of chlorinating polyethylene suspended in water. The latter aqueous suspension chlorination method ( For example, particularly good results are obtained when chlorinated polyethylene produced in Japanese Patent Publication No. 46-21729 is used.

[0007] The flame-retardant resin composition of the present invention can be obtained by mixing predetermined components by a usual method using a mixing roll, a kneader, a Banbury mixer, a kneading extruder or the like. In addition to the composition, various compounding agents such as fillers, reinforcing agents, stabilizers, pigments, and the like can be compounded as commonly performed in the art.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below by way of examples.

[0009]

EXAMPLE As a HIPS, Styron 494 manufactured by Asahi Kasei Kogyo Co., Ltd. was used. SBR used (SBR1 to SBR3) SBR1: Styrene-butadiene-styrene triblock copolymer having a butadiene content of 70% by weight (Asaprene T-420, manufactured by Asahi Kasei Kogyo Co., Ltd.) SBR2: Styrene having a butadiene content of 76.5% by weight -Butadiene random copolymer (manufactured by Nippon Synthetic Rubber Co., Ltd., J
SR1502) SBR3: Styrene-butadiene-styrene triblock copolymer having a butadiene content of 40% by weight (Asaflex 810, manufactured by Asahi Chemical Industry Co., Ltd.) Chlorinated polyethylene (CPE1 to CPE6) used CPE1: weight average molecular weight of 27 Chlorination of 10,000 polyethylene by aqueous suspension method. Chlorine content 8% by weight, heat of fusion 13
cal / g CPE2: Polyethylene having a weight average molecular weight of 270,000 is chlorinated by an aqueous suspension method. Chlorine content 13% by weight, heat of fusion 1
0 cal / g CPE3: Polyethylene having a weight average molecular weight of 270,000 is chlorinated by an aqueous suspension method. Chlorine content 19% by weight, heat of fusion 6
cal / g CPE4: Chlorinated polyethylene having a weight average molecular weight of 270,000 in a carbon tetrachloride solvent. A chlorine content of 19% by weight and a heat of fusion of 0 cal / g CPE5: Polyethylene having a weight average molecular weight of 270,000 is chlorinated by an aqueous suspension method. Chlorine content 30% by weight, heat of fusion 0
cal / g CPE6: Polyethylene having a weight average molecular weight of 80,000 is chlorinated by an aqueous suspension method. Chlorine content 13% by weight, heat of fusion 10
cal / g

The Izod impact test was 3.2 mm thick and 12.7 width.
It was measured according to JIS K6870 using a mm test piece. HIPS
Izod impact strength of 6.0 Kgf
/ Cm ² or more. Flame retardancy is 2 mm thick,
It evaluated according to UL-94 using the test piece of width 12.7 mm. The measurement results are indicated by V0, V1, and V2, where V0 is "with anti-drip property" and V2 is "without anti-drip property". The heat of fusion was measured at a heating rate of 10 ° C./min using DSC-4 manufactured by PerkinElmer. Thermal stability is 250 ℃
For 30 minutes, and the degree of discoloration of the molded product was visually observed. The results are displayed in four stages from 1 to 4, where 1 is "no discoloration", 2 is "slightly yellowing", 3 is "yellowing", and 4 is "brown coloring". If the result is up to 2, there is practicality.

Examples 1 to 7 and Comparative Examples 1 to 7 Each of the compositions shown in Tables 1 and 2 was kneaded with an 8-inch roll at 160 ° C. for 4 minutes to form sheets. 1
It was hot pressed at 100 Kgf / cm ² for 5 minutes with a hot press set at 90 ° C. It is clear that the resin composition of the present invention exhibits particularly excellent physical properties in comparison with Comparative Examples.

[0012]

[Table 1]

[0013]

[Table 2]

[0014]

The resin composition of the present invention is excellent in flame retardancy, and its mechanical strength is remarkably improved. Therefore, it is expected to be applied as a molding material used for molding industrial or household materials requiring flame retardancy, such as electric equipment, OA equipment, and household kitchenware.

Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 23:28) (C08L 51/04 53:02 23:28) (C08K 13/02 5:02 3:22) (C08L 25/04 9) : 00 53:02 23:28)

Claims (5)

[Claims] 1. A high impact polystyrene resin 100
(B) 2 to 10 parts by weight of a styrene-butadiene copolymer having a butadiene content of 50 to 80% by weight,
(C) 10 to 30 parts by weight of a brominated flame retardant, (d) 3 to 10 parts by weight of antimony trioxide, and (e) weight average molecular weight 2
Chlorine content of 100,000-800,000 polyethylene chlorinated 5
A flame-retardant resin composition comprising 1 to 10 parts by weight of a chlorinated polyethylene of 20 to 20% by weight. 2. The flame-retardant resin composition according to claim 1, wherein the content of the chlorinated polyethylene is 2 to 5 parts by weight. 3. The flame-retardant resin composition according to claim 1, wherein the styrene-butadiene copolymer is a styrene-butadiene-styrene triblock copolymer. 4. The flame-retardant resin composition according to claim 1, wherein the chlorinated polyethylene is a chlorinated polyethylene produced by an aqueous suspension chlorination method. 5. The chlorinated polyethylene having a chlorine content of 7 to 5.
13% by weight and a heat of fusion of 3 to 15 cal / g as measured by differential scanning calorimetry (DSC).
5. The flame-retardant resin composition according to any one of items 1 to 4.