JPH05105795A - Flame retardant resin composition - Google Patents

Abstract

PURPOSE:To obtain a flame retardant resin composition capable of providing molded products, excellent in elastic modulus and good in appearance. CONSTITUTION:The objective flame retardant resin composition is obtained by blending (A) 100 pts.wt. flame retardant resin composed of (A1) 30-80wt.% styrene-based resin having 0.2-0.5dl/g reduced viscosity of a portion soluble in methyl ethyl ketone (measured at 30 deg.C in N,N-dimethylformamide solution, C=0.3g/dl), in which the composition of the portion soluble in the methyl ethyl ketone is >=40wt.% alpha-methylstyrene, and (A2) 70-20wt.% vinyl chloride-based resin having 400-8000 polymerization degree with (B) 3-50 pts.wt. glass fiber having 3-50mum fiber diameter and 0.1-50mm fiber length, (C) 1-30 pts.wt. talc having 10-50cc/g oil absorption and 0.5-10mum average particle diameter and (D) 0-10 pts.wt. olefin wax having <=3000, preferably <=2000 weight-average molecular weight. The ratio of the components (B):(C) is (1:0.05) to (1:5).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fiber-reinforced flame-retardant resin composition which gives a molded article having excellent appearance. More specifically, a flame-retardant resin composed of a low molecular weight styrene resin and a low polymerization degree vinyl chloride resin, a specific glass fiber and a specific talc and a low molecular weight olefin wax are blended in a specific ratio. Flame retardant resin composition.

[0002]

2. Description of the Related Art A flame-retardant resin composition comprising a low molecular weight styrene resin and a low polymerization degree vinyl chloride resin is an excellent material in terms of its mechanical properties and economical efficiency, and in recent years, it has been used as a housing for office automation equipment and the like. Its use as wood is increasing. Among OA equipment, a resin for chassis requires a high elastic modulus. As a method of achieving a high elastic modulus, a method of blending glass fiber has been carried out with general resins, but so far, a flame-retardant resin composed of the above-mentioned low molecular weight styrene resin and low polymerization degree vinyl chloride resin This method was not adopted in the composition. The reason for this is that a flame-retardant resin composition composed of a low molecular weight styrene resin and a vinyl chloride resin having a low degree of polymerization has a bad exposure of glass fibers and a decrease in fluidity. This is because there is a problem that it causes decomposition, flashes occur in the molded product, and the external appearance of the molded product remarkably deteriorates. For general resins, addition of glass beads and surface treatment agents for fibers have been investigated as a method of improving the appearance of molded products.The former is sufficient to reduce the elastic modulus, and the latter is sufficient to improve the appearance. Not.

[0003]

In view of the above situation, the present invention provides a fiber-reinforced flame-retardant resin composition having a good appearance and a high elastic modulus.

[0004]

The inventors of the present invention have found that the above flame-retardant resin composition is not a resin having a general molecular weight, but a special injection made of a low molecular weight styrene resin and a low polymerization degree vinyl chloride resin. Since it is a flame-retardant resin composition for molding, considering the fact that the glass fiber easily floats on the surface during molding, etc., the results of diligent examination of a method in which the appearance of the molded article is excellent and the elastic modulus does not decrease, are surprising. In addition, it was found that the use of special talc or olefin wax at a specific ratio can improve the elastic modulus without deteriorating the appearance of the molded product.

That is, according to the present invention, the reduced viscosity of the methyl ethyl ketone soluble portion is 0.2 to 0.5 dl / at 30 ° C. in an N, N-dimethylformamide solution at C = 0.3 g / dl.
A composition comprising a styrene-based resin of g and a vinyl chloride-based resin having a degree of polymerization of 400 to 800, wherein the former is 30
Content of a resin composition obtained by adding specific reinforcing agents (B) and (C) and a modifying agent (D) to a flame-retardant resin (A) whose content is 80 to 80% by weight and the latter is 70 to 20% by weight. As a result, it is possible to obtain a flame-retardant resin composition in which the elastic modulus does not decrease and the appearance of the molded product is excellent.

[0006]

The present invention will be described in detail below. The styrene resin, which is one component used as the component (A) in the present invention, has a reduced viscosity of a methyl ethyl ketone soluble part in an N, N-dimethylformamide solution at C = 0.3 g / dl at 30 ° C. .2 to 0.5 dl / g
Is. The reduced viscosity of the methyl ethyl ketone soluble part is 0.2
If it is less than dl / g, the impact strength will be reduced, and if it exceeds 0.5 dl / g, the thermal stability will be poor. As styrene resin, A
BS resin, AS resin, MBS resin, MABS resin, acrylonitrile-butadiene-styrene-α-methylstyrene copolymer, acrylonitrile-methylmethacrylate-butadiene-styrene-α-methylstyrene copolymer, acrylonitrile-butadiene-styrene-α -Methylstyrene-maleimide copolymer, AAS resin, AE
It includes all of ordinary styrene resins having good compatibility with vinyl chloride resins such as S resin, styrene-maleic anhydride copolymer, and styrene-maleimide copolymer. From the viewpoint of heat resistance, the composition of the methyl ethyl ketone soluble portion of the styrene resin is preferably 40% by weight or more, and more preferably 60% by weight or more.

In the component (A), the styrene resin is 3
It is 0 to 80% by weight, preferably 35 to 75% by weight.
If the styrene resin in the component (A) exceeds 80% by weight,
Flame retardancy and impact strength are significantly reduced. On the other hand, if it is less than 30% by weight, the proportion of the vinyl chloride resin relatively increases, which causes a decrease in thermal stability and a decrease in heat resistance, which is not preferable.

On the other hand, the vinyl chloride resin, which is another component used as the component (A), has a degree of polymerization of 400 to 80.
Homopolymers and / or copolymers of 0, more preferably 450 to 750 and at least 80% by weight or more vinyl chloride, and post-chlorinated polyvinyl chloride are included. The copolymer may contain 20% by weight or less of a monovinylidene compound such as ethylene, vinyl acetate, methyl methacrylate and butyl acrylate as a copolymerization component. If the degree of polymerization is less than 400, the impact strength will decrease and
If it exceeds 00, the thermal stability is significantly lowered. The amount of the vinyl chloride resin in the component (A) is 70 to 20% by weight, preferably 65 to 50% by the reason described in the styrene resin.
It is 25% by weight. Reinforcing agents (B), (C) and modifiers (D), which are added to the above-mentioned component (A) and exhibit an effect of giving a molded article excellent appearance without lowering the elastic modulus, are as follows. It is a compound.

The reinforcing agent (B) has a fiber diameter of 3 to 50 μm,
The glass fiber is preferably 5 to 30 μm and has a fiber length of 0.1 to 50 mm, preferably 0.5 to 30 mm. As the glass component, glass containing 40% by weight or more of silicon oxide is preferable. Further, it is more preferable to apply a surface treatment agent such as a silane compound, a borane compound, an epoxy compound or a polymer. Further, from the viewpoint of handling, the bundled one is more preferable. The amount of component (B) used is the same as component (A) 1
3 to 50 parts by weight, preferably 5 to 40 parts by weight, relative to 00 parts by weight
Parts by weight. If it is less than 3 parts by weight, a sufficient reinforcing effect cannot be exhibited, and if it exceeds 50 parts by weight, the appearance of the molded product is remarkably deteriorated.

The reinforcing agent (C) has an oil absorption of 10 to 50 cc /
g, preferably 15-45 cc / g, average particle size 0.5
The talc has a thickness of 10 to 10 μm, preferably 0.7 to 7 μm. Talc is the main component of magnesium silicate, and may be any one that is purified from talc produced in China, Australia, America, South Korea, Soviet Union, Italy, France, India, Japan, etc., and is not particularly limited. Further, it is preferable that a surface treatment agent is applied in the same manner as the glass fiber. The amount of the component (C) used is 1 to 30 parts by weight, preferably 3 to 20 parts by weight, based on 100 parts by weight of the component (A). If it is less than 1 part by weight, the effect of improving the appearance is not sufficiently exhibited, and if it exceeds 30 parts by weight, the appearance of the molded product is remarkably deteriorated.

The modifier (D) has a weight average molecular weight of 3,000.
The following is preferably an olefin wax of 2000 or less. If the weight average molecular weight exceeds 3,000, the appearance of the molded product deteriorates. Polyolefin wax (D)
Examples thereof include polyethylene wax, polypropylene wax, polymethylpentene wax, and oxides thereof, acid modified products, alcohol modified products, graft modified products of methyl methacrylate and acrylonitrile-styrene, and these may be used alone or in combination of two or more. Used in combination. The amount of polyolefin wax (D) used is
It is 0 to 10 parts by weight, preferably 0.2 to 8 parts by weight, relative to 100 parts by weight of the component (A). If it exceeds 10 parts by weight, the elastic modulus decreases.

As described above, according to the present invention, the reinforcing agent (B), (C), or the reinforcing agent (B) is added to the flame-retardant resin (A) which is a mixture of a special styrene resin and vinyl chloride resin. The flame-retardant resin composition is characterized by further containing a modifier (D). In addition to the well-known antioxidants, heat stabilizers, lubricants and fillers, it is also possible to use them as necessary. A UV absorber, a pigment, an antistatic agent, and also a flame retardant and a flame retardant auxiliary agent can be appropriately used in combination. Especially phenolic antioxidants, phosphite stabilizers used for styrene resins,
Tin-based stabilizers, lead-based stabilizers, and internal / external lubricants such as various fatty acid esters, metal soaps and waxes, which are mixed with vinyl chloride-based resins, have higher performance by using the composition of the present invention as an injection molding resin. It is usually used for making things. Further, the composition of the present invention, vinyl chloride-based resin effectively works and shows good flame retardancy, but depending on the degree of flame retardancy required, a small amount of halogen-based flame retardant, an antimony compound or other flame retardant auxiliary agent. It can also be used by blending.

[0013]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples. "Parts" and "%" in the following Examples, Comparative Examples and Tables are "parts by weight" and "% by weight", respectively.
Indicates.

Example 1 50% styrene resin S-1 having the characteristics shown in Table 1 was used.
Parts, flame-retardant resin (A) consisting of 50 parts of vinyl chloride resin V-1 having the characteristics shown in Table 2, 10 parts of glass fiber (B) having a fiber diameter of 13 μm and a length of 3 mm, oil absorption 35 cc / g,
10 parts of talc (C) having an average particle diameter of 3 μm, molecular weight 100
A mixture of 2 parts of a polyolefin wax (D) of 0, 3 parts of a tin stabilizer and 1 part of a lubricant was blended with a super mixer and then pelletized with a 40 mm extruder to obtain pellets of the flame retardant resin composition of the present invention. Got As a tin stabilizer, 2 parts of dibutyltin maleate and 1 part of dibutyltin mercapto were used, and as a lubricant, 1 part of glycerin tristearate.

The reduced viscosity was measured as follows. The concentration of N, N-dimethylformamide is 0.3 g /
JIS-K6
According to 721, a passage time (t) was measured at 30 ° C. using an Ubbelohde viscometer (capillary viscosity automatic measuring device manufactured by Shibayama Scientific Instruments Co., Ltd.) at 30 ° C. On the other hand, for the solvent N, N-dimethylformamide, the same apparatus was used to measure the passage time (t ₀ ), and the reduced viscosity (ηred) was calculated by the following formula. η red = (t / t ₀ -1) / C (In the formula, C means the concentration of the polymer solution.)

Examples 2 to 5 and Comparative Examples 1 to 3 Flame-retardant resins (A) and reinforcing agents (B), (C) and modifiers shown in Tables 1 and 2 made of styrene resins and vinyl chloride resins. The flame-retardant resin composition of Table 3 containing (B) was prepared in the same manner as in Example 1. From the pellets produced by the above method, the screw rotation speed is 80 rp on a 5 ounce injection molding machine.
A test piece was molded under the conditions of m 2 and nozzle set temperature of 190 ° C. Elastic modulus is ASTM D790 standard (flexural modulus)
It was evaluated by. The heat resistance was evaluated according to the ASTM D736 standard (HDT). The appearance was evaluated by visually observing the surface condition of the test piece at 5 points. That is, the larger the number, the better the appearance. The results are shown in Table 3. From the results in Table 3, it can be seen that the composition of the present invention is excellent especially in terms of the appearance of the molded product.

[0017]

[Table 1] MMA: methyl methacrylate, AN: acrylonitrile, St: styrene, αSt: α-methylstyrene, P
Bd: Polybutadiene rubber having an average particle size of 2500Å, PB
A: Polybutyl acrylate

[0018]

[Table 2]

[0019]

[Table 3]

[0020]

As described above, the flame-retardant resin composition of the present invention provides a molded product having a good elastic modulus and good appearance.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08L 25/08 LDS 9166-4J LDT 9166-4J LDY 9166-4J 27/06 LEP 9166-4J LER 9166 -4J 51/00 LKS 7142-4J 51/06 LLJ 7142-4J 55/02 LMB 7142-4J LME 7142-4J

Claims (4)

[Claims] 1. A flame-retardant resin composition comprising the following components (A), (B), (C) and (D): (A) The reduced viscosity of a methyl ethyl ketone soluble part is 0.2.
~ 0.5 dl / g (N, N-dimethylformamide solution,
30 ° C., C = 0.3 g / dl) Styrenic resin 30
100 parts by weight of a flame-retardant resin consisting of 80 to 80% by weight and 70 to 20% by weight of a vinyl chloride resin having a degree of polymerization of 400 to 800, (B) a glass having a fiber diameter of 3 to 50 μm and a fiber length of 0.1 to 50 mm. Fiber 3 to 50 parts by weight, (C) Oil absorption amount 10 to 50 cc / g, average particle diameter 0.5 to 1
1 to 30 parts by weight of 0 μm talc, and (D) 0 to 10 parts by weight of an olefin wax having a weight average molecular weight of 3000 or less. 2. The flame-retardant resin composition according to claim 1, wherein the ratio of the glass fiber (B) to the talc (C) is in the range of 1: 0.05 to 1: 5. 3. The flame-retardant resin composition according to claim 1, wherein the olefin wax (D) has a weight average molecular weight of 2000 or less. 4. The flame-retardant resin composition according to claim 1, wherein the composition of the methyl ethyl ketone-soluble portion of the styrene resin is 40% by weight or more of α-methylstyrene.