JPH0352940A - Flame-retardant resin composition for injection molding - Google Patents

Abstract

PURPOSE:To obtain the title composition having excellent heat processing properties, improved heat resistance, fluidity and appearance by blending a resin mixture comprising a specific styrene-based resin and vinyl chloride-based resin with a specific compound as a stabilizer. CONSTITUTION:100 pts.wt. resin mixture comprising (A) 25-85 pts.wt. styrene- based resin (e.g. ABS resin) having 0.25-0.70dl/g reduced viscosity of a methyl ethyl ketone soluble component at 30 deg.C in 0.3g/dl N,N-dimethylformamide solution and (B) 78-15 pts.wt. vinyl chloride-based resin (e.g. vinyl chloride homopolymer) having 400-1,000 average degree of polymerization is blended with (C) 0.1-10 stabilizer using a compound shown by formula I and a compound shown by formula II [R<1> and R<2> are 1-8C alkyl; R<3>, R<4> and R<5> are group sown by formula III (R<6> is 1-18C alkyl)] in the ratio of the compound shown by formula I and the compound shown by formula II of (95/5)-(50/50), optionally an antioxidant, a heat stabilizer, etc., to give the objective composition.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a flame-retardant resin composition for injection molding which has extremely excellent moldability. The present invention relates to a flame-retardant resin composition for injection molding which has extremely excellent thermal stability during heating and has good heat resistance, impact resistance, fluidity, and flame retardancy.

[Prior Art and Problems] Styrenic flame-retardant resins have an excellent balance of heat resistance, impact resistance, and processability, and are being used in increasing amounts in various fields.

Among styrene-based resins, ABS-based flame-retardant resins made by blending vinyl chloride-based resins have particularly high impact resistance,
It has the characteristics of excellent flame retardancy and the appearance of molded products, and these characteristics have recently been recognized mainly in the field of office automation equipment, and demand has increased significantly.

However, in the field of OA equipment, requirements regarding appearance are becoming stricter year by year. In this respect, ABS flame-retardant resins made by blending vinyl chloride resins have a high melt viscosity during molding because they contain vinyl chloride resins, and the resin can be easily mixed with metals such as screws, cylinders, and molds. There is a problem in that the shear heat generation increases, causing thermal decomposition and causing burning, flashing, etc. in the molded product.

Conventionally, in order to solve these problems, the amount of tin-based stabilizers, lubricants, antioxidants, etc. has been increased until an appearance that meets the market requirements is obtained. However, with these means, the heat resistance, fluidity, and impact resistance of the resin are impaired, and the economical efficiency of the resin becomes worse.

[Problems to be Solved by the Invention] The purpose of the present invention is to provide a flame retardant material for injection molding that provides molded products with excellent heat processability, heat resistance, impact resistance, fluidity, flame retardance, and good appearance. Our objective is to provide resin composites.

[Means for Solving the Problems] As a result of intensive study by the present inventors on a method that can solve these problems without adding a large amount of stabilizers etc., surprisingly, the general formula: S-CHtCOO -R" (3) [In the formula, R6 represents an alkyl group having 1 to 18 carbon atoms.] By using a specific tin-based stabilizer containing an alkylthioglycolate group represented by the formula, moldability is significantly improved. I found out that it can be done.

That is, the gist of the present invention is that (A) the reduced viscosity of the methyl ethyl ketone soluble portion is 30°C (
25 to 85 parts by weight of a styrenic resin having a D0.39/d (0.25 to 0.70 dl/g0 in a N,N-dimethylformamide solution) and (B) an average degree of polymerization of 400 to 400. 1000 vinyl chloride resin 7
100 parts by weight of a resin mixture consisting of 5 to 15 parts by weight, and (C) as a stabilizer, general formula: R"R' and/or general formula: [wherein R1 and R2 are alkyl groups having 11 to 8 carbon atoms] ,
R3, R' and RS have the general formula: -S-CHtCOO-R" (3) (wherein R
@ represents an alkyl group having 1 to 18 carbon atoms. ) represents a group represented by ] A flame retardant resin composition for injection molding containing 0.1 to 10% by weight of the compound shown below.

The styrene resin (A) has a methyl ethyl ketone soluble content (
7) It original viscosity is 0.39/de N,N- at 30℃
0.25-0.70 in dimethylformamide solution
dl/g, preferably 0.25-0.55 d(2/li
It is a resin that is t. If the reduced viscosity is less than 0.25 dl/g, the impact strength will decrease, and if it exceeds 0.70 dff/9, the fluidity will decrease and the thermal stability during molding will deteriorate.

Styrenic resin [1 (A) includes all normal styrenic resins that can be mixed with vinyl chloride resin, ABS resin,
AS resin, MABS resin, MBS resin, AAS resin, A
ES resin, acrylonitrile-butadiene-styrene-α-methylstyrene copolymer, acrylonitrile-methyl methacrylate-butadiene-styrene-α-methylstyrene copolymer, styrene-maleic anhydride copolymer, styrene-maleimide copolymer, Acrylonitrile-methyl methacrylate-butadiene-styrene-α
-Methylstyrene-maleimide copolymer and the like are exemplified.

The average degree of polymerization of the vinyl chloride resin (B) is 400 to
oo, preferably 400-700. When the average degree of polymerization is less than 400, the impact strength decreases and
If the temperature exceeds 100%, the thermal stability will be significantly reduced. The vinyl chloride resin (B) includes a vinyl chloride homopolymer or a copolymer in which 80% by weight or more is vinyl chloride, and post-chlorinated polyvinyl chloride. The copolymer may contain up to 20% by weight of a monovinylidene compound such as ethylene, vinyl acetate, methyl methacrylate, butyl acrylate.

The stabilizer (C) has the general formula: and/or the general formula: [wherein Rl and R'' are an alkyl group having 1 to 8 carbon atoms,
R3, R4 and R5 have the general formula: S CHzCOO R' (3) (wherein R
6 represents an alkyl group having 1 to 18 carbon atoms. ) represents a group represented by ] It is a compound shown by. As a stabilizer, 2 of the compound
Mixtures of more than one species or mixtures with other stabilizers may also be used. For example, the ratio (weight ratio) of the compounds represented by general formulas (1) and (2) is (1)/(2)=95/5 to 5.
0/5 0, preferably 90/10-7 5/2 5
If a mixture of the following is used as a stabilizer, a resin composition having extremely excellent moldability can be obtained.

The stabilizer (C) is particularly important in the present invention, and is characterized by having a group represented by general formula (3). In general formulas (1) and (2), Rl and R2 are alkyl groups having 1 to 8 carbon atoms, preferably 4 to 8 carbon atoms. In particular, when Rl and R2 are butyl groups, the shape processability is extremely excellent. When the number of carbon atoms exceeds 8, moldability deteriorates. The alkyl groups of R1 and R2 may or may not have a side chain, and are not particularly limited.

In general formula (3), R@ is an alkyl group having 1 to 18 carbon atoms, preferably 1 to 10 carbon atoms, and more preferably 4 to IO carbon atoms. When the number of carbon atoms exceeds 18, moldability deteriorates. The alkyl group R'' may or may not have a side chain, and is not particularly limited.

In the flame retardant resin composition of the present invention, styrenic resin (
A) is a combination of styrene resin (A) and vinyl chloride resin (B).
) to 100 parts by weight of the resin mixture consisting of 25 to 8 parts by weight.
5 parts by weight, preferably 35 to 75 parts by weight. If it is less than 25 parts by weight, molding processability will be reduced, and if it exceeds 85 parts by weight, flame retardancy will be reduced. The vinyl chloride resin (B) is preferably used in an amount of 75 to 15 parts by weight based on 100 parts by weight of the resin mixture.

(2) If it is less than 5 parts by weight, flame retardancy will be reduced, and if it exceeds 75 parts by weight, moldability will be reduced.

The amount of stabilizer (C) is 0.1-10 parts by weight, preferably 0.5-5 parts by weight, based on 100 parts by weight of the resin mixture. If the amount used is less than 0.1 part by weight, moldability will be poor, and if it exceeds IO part by weight, impact strength will decrease.

The flame-retardant resin composition of the present invention usually contains well-known antioxidants, heat stabilizers, and lubricants, as well as suitable UV rays if necessary.
Absorbers, pigments, antistatic agents, and flame retardants and flame retardant aids can also be used together. Special products include phenolic antioxidants, phosphite stabilizers used in styrene resins, tin stabilizers and lead stabilizers used in vinyl chloride resins, various fatty acid esters, metal soaps, waxes, etc. Internal and external lubricants, etc. can be used to make the flame-retardant resin composition of the present invention higher performance as a molding resin. In addition, the flame retardant resin composition of the present invention exhibits good flame retardancy due to the effective action of the vinyl chloride resin;
Depending on the degree of flame retardancy required, a small amount of a flame retardant aid such as a halogen flame retardant or an antimony compound may be added.

The content of components other than styrene resin (A), vinyl chloride resin (B) and stabilizer (C) is 100% of the resin mixture.
It is preferably 25 parts by weight or less, more preferably 20 parts by weight.
Parts by weight or less are preferred. When the content exceeds 25% by weight, impact strength decreases.

Polymerization of the styrene resin (A) and vinyl chloride resin (B) can be carried out by a known polymerization method, but there are no particular restrictions on the type or operation. After the polymerization is completed, a desired powder is obtained by a known method, for example, by precipitating the polymer, filtration, washing, and drying.

The flame-retardant resin composition is a powdered styrene resin (
It is obtained by blending A) with a vinyl chloride resin (B), a stabilizer (C), compounding agents, etc.

Injection molding can be performed using pellets (or powder). Pellets can be produced using an ordinary extruder, and the screw shape, extrusion temperature, and speed are not particularly limited as long as the conditions do not deteriorate the vinyl chloride resin (B).

As for the injection molding conditions, a normal injection molding machine can be used, and the conditions are sufficient as long as the vinyl chloride resin (B) does not deteriorate, and there are no particular limitations on the screw shape, injection temperature, speed, pressure, etc. It's not a thing.

The flame-retardant resin composition of the present invention is suitable for injection molding.

[Effect of the invention] The resin composition of the present invention has excellent heat processability, heat resistance,
Provides molded products with good impact resistance, fluidity, flame retardancy and appearance.

[Preferred Embodiments of the Invention] The present invention will be specifically explained below by showing Reference Examples, Examples, Comparative Examples, and Test Examples. These examples are not intended to limit the invention. In the following, "ro" means parts by weight, "%"
” indicates weight %.

Reference example (a) Production of styrenic resin (A) In a reaction vessel equipped with a stirrer and a cooler, 250 parts of water,
0.4 parts of sodium formaldehyde sulfoxylate, 0.0025 parts of ferrous sulfate, 0.0 parts of disodium ethylenediaminetetraacetate. 1 part of O and 3 parts of sodium palmitate were charged. After deoxygenation, a mixture of monomers in the proportions shown in Table 1, 0.3 parts of cumene hydroperoxide initiator, and t-dodecylmercabutane (desired (the number of parts that would give a reduced viscosity) was continuously added dropwise over a period of 5 hours. After the dripping is finished,
Stirring was further continued at 60° C. for 1 hour to complete the polymerization and obtain a latex of copolymer (A-a).

Also, add 25 liters of water to a reaction vessel equipped with a stirrer and a cooler.
0 parts, sodium formaldehyde sulfoxylate 0
．． 4 parts, 0.0025 parts of ferrous sulfate, 0.0025 parts of disodium ethylenediaminetetraacetate. 1 part of O and a predetermined amount of rubbery polymer shown in Table 1 were charged.

After deoxygenation, the mixture was stirred and heated to 60° C. in a nitrogen stream, and then a monomer mixture in the proportions shown in Table 1 and 0.2 parts of cumene hydroperoxide as an initiator were continuously added dropwise over 5 hours. After completion of the dropwise addition, stirring was further continued at 60° C. for 1 hour to complete the polymerization and obtain a latex of the graft copolymer (A-b).

Copolymer (A-a) latex and graft copolymer (A-a)
-b) Mix the latex in the proportions shown in Table 1, add a phenolic antioxidant, coagulate with an aqueous calcium chloride solution, wash with water, dehydrate, and dry.
Powders 1 to 4) were obtained.

The reduced viscosity of the styrene resin was measured as follows. The concentration of styrene resin is 0. Dissolve the polymer solution in N,N-dimethylformamide to give 39/dQ, and use an Ubbelohde viscometer (capillary viscosity automatic measuring device manufactured by Shibayama Scientific Instruments Manufacturing Co., Ltd.) at 30°C according to JIS-K672i. ) was used to measure the transit time (1). On the other hand, using the same apparatus for the solvent N,N-dimethylformamide, the transit time (t0) was measured at 30°C, and the reduced viscosity (ηred) was calculated using the following formula: '7red= (t/to! )/C [wherein C represents the concentration of the polymer solution.

Ko.

Table 1 (Note) Rubber-like polymer...Used in latex state PBd: Polybutadiene rubber, average particle size 2,500 people PBA: Bolybutyl acrylate rubber, average particle size 2,400 people Monomer 8N: Acrylonitrile St: Styrene α-St: Method for producing α-methylstyrene vinyl chloride resin fil (B) In an autoclave equipped with a stirrer and a cooler, 250 parts of water, 0.1 part of methylcellulose, and g-tylperoxy 0.1 part of trimethyl adipate and 2-mercaptoethanol (the number of parts that gives the desired average degree of polymerization) are charged,
After replacing the internal air with nitrogen, vinyl chloride monomer lO
I prepared part O. After polymerization at 50°C for 8 hours, unreacted monomers were collected when the pressure decreased by 2k97Cx'' from the steady pressure.The resulting polymer slurry was dehydrated and dried to form vinyl chloride resins (B) shown in Table 2. -1 to 3) powders were obtained.

The vinyl chloride resin (B-4'') was obtained by chlorinating the vinyl chloride resin (B-2) in a conventional manner.

2nd Omotesono 221 (Note) Example 1 50 parts of styrene resin (A-2) shown in Table 1, 50 parts of vinyl chloride resin (B-2) shown in Table 2, 50 parts of vinyl chloride resin (B-2) shown in Table 3. 4 parts of stabilizer (C-1), stabilizer (C-2) Toro, 1 part of glycerin tristearate as a lubricant, 1 part of polyethylene wax, and 1 part of titanium oxide as a pigment were blended using a super mixer, and extruded to 40 nm. Pellets were prepared using a machine.

Examples 2 to 7 Styrenic resin (A) shown in Table 1, vinyl chloride resin (B) shown in Table 2, stabilizer (C) shown in Table 3, (C
-1, 2) and tin-based stabilizers (C-3 to 6) in the amounts shown in Table 4, 1 part of glycerin tristearate and 1 part of polyethylene wax as lubricants, and titanium oxide as pigment! The components were blended using a super mixer, and pellets were produced using a 40 mm extruder.

Comparative Examples 1 to 12 Styrene resin (A) shown in Table 1, vinyl chloride resin (B) shown in Table 2, stabilizer (C) shown in Table 3, (C
-1, 2) and/or a tin-based stabilizer (C-3-6) in the amounts shown in Table 5, 1 part of glycerin tristearate as a lubricant, 1 part of polyethylene wax, and 1 part of titanium oxide as a pigment in a super mixer. Blend by 40
Pellets were produced using a mm extruder.

Table 3 Table 4 1 loss (1) Molding processability The pellets obtained in the Examples and Comparative Examples were molded using a 5-ounce injection molding machine at a screw rotation speed of 20 O rpm and a nozzle temperature of 200° C. for 150 strokes x 2. 0 0nmX
A 1.5 mm test piece was molded and moldability was evaluated. Molding processability was evaluated by the degree of discoloration (surface appearance) of the test piece after shaping. Evaluation was made using a 5-point system, with 5 points being the highest and 1 point being the lowest. The larger the number, the better the formability.

(2) Impact resistance, heat resistance, and flame retardancy The pellets obtained in Examples and Comparative Examples were tested using a 5-ounce injection molding machine at a screw rotation speed of 8 orpm and a nozzle temperature of 200°C to the dimensions listed in each standard. Pieces were molded and tested for impact resistance, heat resistance and flame retardancy.

The vertical impact resistance was evaluated by an Izod impact test based on the ASTM (D-648) standard.

Heat resistance Heat resistance is based on ASTM (D-256) standard, 18
．． 6 k9/c was evaluated based on the heat distortion temperature under load.

1 indigo raw Flame retardancy was evaluated based on the UL-94 standard.

(3) Fluidity A fluidity test was conducted using the pellets obtained in Examples and Comparative Examples. Fluidity is 19 by Koka formula B method flow.
Evaluation was made under the conditions of 0°C and a load of 150 k9/Cx''.

The results are shown in Table 6.

From Table 6, the flame retardant resin composites of the present invention (Examples 1 to 7)
) was found to have excellent shapeability and good impact resistance, heat resistance, fluidity, and flame retardancy.

Claims (1)

[Claims] 1. (A) The reduced viscosity of the methyl ethyl ketone soluble component is 30
25 to 85 parts by weight of a styrenic resin in the range of 0.25 to 0.70 dl/g and (B) an average degree of polymerization of 4 in a 0.3 g/dlN,N-dimethylformamide solution at °C.
100 parts by weight of a resin mixture consisting of 75 to 15 parts by weight of a vinyl chloride resin having a molecular weight of 00 to 1000; General formula: ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (2) [In the formula, R^1 and R^2 are alkyl groups having 1 to 8 carbon atoms, and R^3, R^4 and R^5 are general Formula: -S-CH
_2COO-R^6(3) (In the formula, R^6 represents an alkyl group having 1 to 18 carbon atoms.) ] A flame-retardant resin composition for injection molding containing 0.1 to 10 parts by weight of a compound represented by the following. 2. The weight ratio of the compounds represented by the general formulas (1) and (2) of the stabilizer (C) is (1)/(2) = 95/5 to 50
2. The flame retardant resin composition for injection molding according to claim 1, wherein the flame retardant resin composition is within the range of /50. 3. R^1 of general formulas (1) and (2) of the stabilizer (C)
The flame-retardant resin composition for injection molding according to claim 1 or 2, wherein and R^2 is a butyl group.