JPH0496955A - Flame-retardant resin composition - Google Patents

Abstract

PURPOSE:To obtain a flame-retardant resin composition having excellent heat resistance, impact resistance and processing properties by blending specific amounts of a specific maleimide-based copolymer, a graft copolymer and a vinyl chloride-based resin. CONSTITUTION:(A) 15-80 pts.wt. maleimide-based copolymer comprising 5-60wt.% maleimide compound shown by the formula (R is H, 1-4C alkyl, aryl, etc.), 10-70wt.% aromatic vinyl compound, 5-30wt.% vinyl cyanide, 20-70wt.% alkyl methacrylate, etc., having 0.15-0.5dl/g reduced viscosity of a methyl ethyl ketone soluble part in a dimethylformamide solution at 30 deg.C is blended with (B) 5-40 pts.wt. graft copolymer prepared by polymerizing 40-90wt.% rubber-like polymer with 60-10wt.% monomer mixture prepared by blending a vinyl cyanide compound with an alkyl(meth)acrylate, etc., in a specific ratio and (C) 15-80 pts.wt. vinyl chloride-based resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a flame-retardant resin composition having excellent heat resistance and impact resistance. More specifically, a low molecular weight maleimide resin containing a maleimide compound, a vinyl cyanide compound, an alkyl acrylate, and an aromatic vinyl as essential components, and a graft copolymer containing a vinyl cyanide compound and an alkyl (meth)acrylate as essential components. The present invention relates to a flame-retardant resin composition comprising: and a low polymerization degree vinyl chloride resin.

Styrenic flame-retardant resins are increasingly being used in various fields because of their excellent balance of heat resistance, impact resistance, and processability.

Among styrene-based resins, ABS-based flame-retardant resins, which are polymer alloys of vinyl chloride-based resins and ZABS-based resins, have particularly high impact resistance and resistance compared to ordinary ABS-based flame-retardant resins that use bromine-based flame retardants. It has the characteristics of excellent flammability and the appearance of molded products, and recently, these characteristics have been recognized and the demand for it has increased significantly, mainly for housings in the field of office automation equipment.

[Conventional technology and problems]

However, in the field of OA equipment, requirements for molded products are becoming stricter year by year. In particular, due to the increase in internal heat generation and thinner housings associated with downsizing of OAQ devices, a vinyl chloride/ABS type flame retardant resin with high heat resistance is required. As a method to improve heat resistance, α
- A method of using ABS resin using methylstyrene is common, but recently a method of copolymerizing maleimide to improve heat resistance has been proposed. For example, JP-A-6
1-143459.62-34936.62-3493
8.63-182364.63-191853 contains a copolymer of an aromatic vinyl compound, a vinyl cyanide compound and a maleimide compound, and JP-A-61-46249.
No. 63-196643 proposes a method of improving heat resistance by blending copolymers of an aromatic vinyl compound, an alkyl methacrylate, and a maleimide compound with a vinyl chloride resin.

However, compositions prepared using the former method have the disadvantage that the maleimide copolymer and the vinyl chloride resin are difficult to be compatible with each other, and impact resistance is not sufficiently developed. Furthermore, in the composition prepared by the latter method, the maleimide copolymer and the vinyl chloride resin are easily compatible, but it is necessary to use a large amount of the maleimide copolymer in order to improve heat resistance. That is, the latter composition has a drawback in that the effect of improving the heat resistance of the maleimide copolymer is low.

[Means for solving problems]

As a result of intensive studies on flame-retardant resin compositions that have both heat resistance and impact resistance, the present inventors surprisingly found that maleimide compounds, aromatic vinyl compounds, alkyl methacrylates, and vinyl cyanide compounds are essential components. When blended with a vinyl chloride resin, a maleimide copolymer copolymerized at a specific ratio and a graft copolymer copolymerized at a specific ratio with a vinyl cyanide compound and alkyl (meth)acrylate as essential components. It has been found that impact resistance and heat resistance are improved at the same time.

That is, the present invention was completed based on the discovery that both impact resistance and heat resistance can be satisfied for the first time by allowing both alkyl methacrylate and vinyl cyanide compound to coexist as copolymerization components.

That is, the present invention provides the following maleimide copolymer (A) 1
5 to 80 parts by weight, 5 to 40 parts by weight of graft copolymer (B), and 15 to 80 parts by weight of vinyl chloride resin (C) [However, (A) + (B) + (C) = 100 parts by weight The content is a flame-retardant resin composition having excellent heat resistance and impact resistance.

(A) - Maleimide compound 5 represented by -enlarged H-C=C-H (wherein R represents an alkyl group, a cycloalkyl group, an aryl group, or a substituted aryl group having 1 to 4 H1 carbon atoms) ~60% by weight, aromatic vinyl compound 10-70% by weight, vinyl cyanide compound 5
~30% by weight, 20-70% by weight of alkyl methacrylate and 0-20% by weight of other monomers copolymerizable with these.
and the reduced viscosity of the methyl ethyl ketone soluble portion of the copolymer is 30° in dimethyl formamide solution.
A maleimide copolymer having C in the range of 0.15 to 0.5 dl/g, (B) 40 to 90% by weight of a rubbery polymer, and 60 to 10% by weight of a monomer mixture consisting of the following group 2. Graft copolymer obtained by polymerization; 10≦e+f/4≦40, e+f+g+h=100, e≧0, f≧0. 0≦g≦90, and O≦h≦20 [However, in the formula, e, f, g and h are vinyl cyanide compound (e), alkyl (meth)acrylate-1-
(f), an aromatic vinyl compound (g), and another vinyl compound (h) copolymerizable with these, and the numbers indicate the weight ratio (%) in the monomer mixture. ], (C) A vinyl chloride resin having a degree of polymerization of 400 to 800.

The maleimide copolymer (A) in the present invention contains 5 to 60% by weight of a maleimide compound and 10 to 60% by weight of an aromatic vinyl compound.
70% by weight, 5 to 30% by weight of vinyl cyanide compound, 20 to 70% by weight of alkyl methacrylate, and 0 to 20% by weight of other copolymerizable monomers, and the methyl ethyl ketone soluble portion of the copolymer. Reduced viscosity of 30° CT: O, 15-0.5 d in dimethylformamide solution
It is a copolymer with a range of l/g.

The maleimide compounds used in the maleimide copolymer (A) are those represented by the general formula 2 above, such as maleimide, N-phenylmaleimide, N-methylmaleimide, N-ethylmaleimide, N-propyl Examples include maleimide, N-isopropylmaleimide, N-butylmaleimide, N-isobutylmaleimide, N-tert-butylmaleimide, N-cyclohexylmaleimide, and the like, and these may be used alone or in combination of two or more.

Examples of the aromatic vinyl compound used in the maleimide copolymer (A) include styrene, α-methylstyrene, methylstyrene, and chlorostyrene, which may be used alone or in combination of two or more. From the viewpoint of impact resistance, preferably 10 to 40% by weight of α-methylstyrene is used.

Examples of vinyl cyanide compounds used in the maleimide copolymer (A) include acrylonitrile and methacrylonitrile, which may be used alone or in combination of two or more.

Examples of the alkyl methacrylate used in the maleimide copolymer (A) include methyl methacrylate, ethyl methacrylate, butyl methacrylate, glycidyl methacrylate, 2-hydroxyethyl methacrylate,
-ethylhexyl methacrylate and the like, all of which may be used alone or in combination of two or more.

Other copolymerizable vinyl compounds used in the maleimide copolymer (A) include methyl acrylate, ethyl acrylate, butyl acrylate, methacrylic acid, etc., which may be used alone or in combination of two or more. .

Among the monomer components constituting the maleimide copolymer (A), the amount of the maleimide compound is 5 to 60% by weight, preferably 10 to 50% by weight. If the maleimide compound content is less than 5% by weight, the heat resistance will decrease, and if it exceeds 60% by weight, the impact resistance will decrease significantly.

The amount of aromatic vinyl compound is 10-70% by weight, preferably 10-50% by weight. If it is less than 10% by weight, the fluidity will be significantly lowered, and if it exceeds 70% by weight, the heat resistance and impact resistance will be significantly lowered. The amount of vinyl cyanide monomer is from 5 to 30% by weight, preferably from 8 to 25% by weight. 5
If it is less than 30% by weight or more than 30M%, the impact resistance will be greatly reduced. The amount of alkyl methacrylate is 20-7
0% by weight, preferably 25-60% by weight, more preferably 30-55% by weight. If it is less than 20% by weight, the impact resistance will be greatly reduced, and if it exceeds 70% by weight, the heat resistance will be significantly reduced.

The reduced viscosity of the methyl ethyl ketone soluble portion of the maleimide copolymer (A) in dimethyl formamide solution is 0.
15 to 0.5 dl/g, preferably 0.2 to 0.
It is 4. If the reduced viscosity is less than 0.15 dl/g, the impact strength will decrease, and if it exceeds 0.5 dl/g, the processability will decrease, which is not preferred.

The graft copolymer (B) in the present invention is a copolymer obtained by polymerizing 60 to 10% by weight of a monomer mixture consisting of the following second group to 40 to 90% by weight of a rubbery polymer.

10≦e+f/4≦40, e+f+g+h=], 00, e≧0, f≧0. 0≦g≦90, and O≦h≦20 (wherein, e, f, g and h are vinyl cyanide compound (e), alkyl (meth)acrylate (
f), an aromatic vinyl compound (g), and another vinyl compound (h) copolymerizable with these, and the numbers indicate the weight ratio (%) in the monomer mixture. ) Examples of the rubbery polymer in the graft copolymer (B) include diene rubbers such as polybutadiene rubber, styrene-butadiene copolymer rubber (SBR), acrylonitrile-butadiene rubber (NBR), and polybutyl acrylate. acrylic rubber such as, and ethylene-propylene
Examples include polyolefin rubbers such as diene terpolymer rubber (EPDM), and these may be used alone or in combination of two or more.

Examples of the vinyl cyanide compound (e) in the graft copolymer (B) include acrylonitrile, methacrylonitrile, etc., and examples of the alkyl (meth)acrylate (f) include methyl acrylate, ethyl acrylate, ethyl acrylate, butyl acrylate, etc. Examples of the aromatic vinyl compound (g) include styrene, α-methylstyrene, methylstyrene, chlorostyrene, etc., and examples of the copolymerizable vinyl compound (h) include acrylic acid, methacrylic acid, phenylmaleimide, etc. These may be used alone or in combination of two or more.

In the graft copolymer (B), the rubbery polymer is 40
~90% by weight is used. If the amount is less than 40% by weight or more than 90% by weight, the impact resistance will decrease, which is undesirable.
If the meth)acrylate or aromatic vinyl compound is outside the range of the above-mentioned group 2, the impact resistance will decrease, which is not preferable.

The vinyl chloride resin (C) in the present invention has a polymerization degree of 4.
A vinyl chloride polymer having a molecular weight of 00 to 800 is used, preferably a vinyl chloride polymer having a molecular weight of 400 to 700. Degree of polymerization is 40
If it is less than 0, the impact strength will decrease, and if it exceeds 800, the workability will be significantly decreased, which is not preferable. The vinyl chloride resin (C) includes a homopolymer and/or copolymer in which 80% by weight or more is vinyl chloride, and post-chlorinated polyvinyl chloride. The copolymer may contain 20% by weight or less of a monovinylidene compound such as ethylene, vinyl acetate, methyl methacrylate, butyl acrylate, etc. as a copolymerization component.

In the flame retardant resin of the present invention, a maleimide copolymer (
A) is used in an amount of 15 to 80 parts by weight.

If it is less than 15 parts by weight, heat resistance will decrease, and if it exceeds 80 parts by weight, flame retardancy will decrease, which is not preferable.

The graft copolymer (B) is used in an amount of 5 to 40 parts by weight. If it is less than 5 parts by weight, the impact resistance will decrease, and if it exceeds 40 parts by weight, the heat resistance will decrease, both of which are undesirable.15 to 80 parts by weight of the vinyl chloride resin (C) is used. 1
If it is less than 5 parts by weight, the flame retardance will be lowered, and if it exceeds 80 parts by weight, the processability will be lowered, both of which are not preferred.

Maleimide copolymer (A) and graft copolymer (B)
can be polymerized using a known polymerization initiator and polymerization degree regulator, and there are no particular restrictions on the type and amount used. After the polymerization is completed, the desired powder can be obtained by solidifying by a known method. Maleimide copolymer (A
) and the graft copolymer (B) may be blended in a Latinx state, or after coagulating, the vinyl chloride resin (C
), or may be blended with other additives.

As mentioned above, the flame retardant resin composition of the present invention contains a maleimide compound, an aromatic vinyl compound, a vinyl cyanide monomer,
Maleimide copolymer (A) and graft copolymer (B) formed by polymerizing alkyl methacrylate as an essential component
A new flame retardant product with improved heat resistance and impact resistance by using a copolymer (A) consisting of a polyvinyl chloride resin (C) and a vinyl cyanide monomer and an alkyl methacrylate in specific amounts. It is a resin composition.

The flame-retardant resin composition of the present invention contains not only well-known antioxidants, heat stabilizers, and lubricants, but also UV absorbers, pigments, antistatic agents, flame retardants, Combustion aids may also be used. In particular, phenolic antioxidants and phosphite stabilizers used in styrene resins, tin stabilizers and lead stabilizers used in vinyl chloride resins, various fatty acid esters, metal soaps, waxes, etc. A lubricant or the like can be used to improve the performance of the flame-retardant resin composition of the present invention as a molding resin. In the flame-retardant resin composition of the present invention, the vinyl chloride resin works effectively and shows good flame retardancy, but depending on the degree of flame retardance required, small amounts of halogen flame retardants, antimony compounds, etc. A flame retardant aid may also be added.

C Example] Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but these do not limit the present invention. still,
In the following description, "r part" indicates parts by weight, and "r%" indicates weight %.

Examples 1 to 10, Comparative Examples 1 to 9 (a) Synthesis of maleimide copolymer (A) The following substances were charged into a reaction vessel equipped with a stirrer and a cooler in a nitrogen stream.

water 250
0.4 parts sodium formaldehyde sulfoxylate 0.0025 parts ferrous sulfate 0.01 parts disodium ethylenediaminetetraacetate 3 parts sodium dotecylbenzenesulfonate The mixture was heated to 60°C and stirred in a nitrogen stream. After that, a monomer mixture in the proportion shown in Table 1 was continuously added dropwise to the container with cumene hydroperoxide as an initiator and tertiary dodecyl mercaptan as a polymerization degree regulator while stirring at 60°C over 5 hours. Added.

After the dropwise addition was completed, stirring was further continued at 60°C for 1 hour to complete the polymerization.

(B) Synthesis of Graft Copolymer (B) In a nitrogen stream, the following substances and the rubbery polymers shown in Table 2 were charged into a reaction vessel equipped with a stirrer and a cooler.

water 25
0 parts Sodium formaldehyde sulfoxylate 0.2
Part ferrous sulfate 0.0025 parts Disodium ethylenediaminetetraacetate 0.01 part Rubber polymer The specified amount shown in Table 2 After heating and stirring at 60°C in a nitrogen stream, the monomer amount in the proportion shown in Table 2 Cumene hydroperoxide as an initiator was continuously added dropwise to the reaction vessel mixture over a period of 5 hours with stirring at 60°C. After the dropwise addition was completed, stirring was further continued at 60°C for 1 hour to complete the polymerization.

The maleimide copolymer (A) obtained in (a) above and the latex of the graft copolymer (B) obtained in (b) were uniformly mixed in the proportions shown in Table 4, and After adding antioxidants and coagulating with calcium chloride aqueous solution,
The mixture was washed with water, dehydrated, and dried to obtain a mixed powder of maleimide copolymer (A) and graft copolymer (B).

Table 2 (Note) Rubbery polymer is used in latex state PBd: Polybutadiene rubber, average particle size 2500P
BA: Polybutyl acrylate rubber, average particle size 2400
(c) Manufacture of flame-retardant resin composition The copolymer (A) and graft copolymer (B) produced as in (a) and (b) above, and the average degree of polymerization and chlorine shown in Table 3. vinyl chloride resin (C) and a tin stabilizer,
A lubricant and a flame retardant aid were blended in a super mixer at the ratio shown in Table 4, and pellets were produced using a 40ml extruder. As the tin stabilizer, 2 parts of dibutyl tin maleate and 1 part of dibutyl tin mercapto were used, and as the lubricant, 1 part of glycerin tristearate and 1 part of polyethylene wax were used. A test piece was molded from this pellet using a 5-ounce injection molding machine under the conditions of a screw rotation speed of 80 rpm+ and a nozzle temperature setting of 190°C, and heat resistance, impact resistance, workability, and flame retardance were measured. The results are shown in Table 4.

Heat resistance is based on ASTM (D-256) standard, 18
, and was evaluated at a heat distortion temperature of 6 kg/c1il load.

Processability is spiral flow value (Nissin FS-75 injection molding machine, nozzle temperature) 95°C 1 injection pressure 1100kg/c
d, mold temperature 40°C).

Impact resistance is A, based on STM (D-648) standard,
It was evaluated using an Izot impact test.

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

From the results in Table 4, it can be seen that the flame-retardant resin composition of the present invention is particularly excellent in heat resistance and impact strength, and also has good processability and flame retardancy.

(Action/Effect) As described above, according to the present invention, a flame-retardant resin composition having excellent heat resistance and impact resistance as well as good processability is provided.

Claims (1)

[Claims] 1. 15 to 80 parts by weight of the following maleimide copolymer (A), 5 to 40 parts by weight of the graft copolymer (B), and 15 to 80 parts by weight of vinyl chloride resin (C) [However, (A) +
(B) + (C) = 100 parts by weight] A flame-retardant resin composition with excellent heat resistance and impact resistance; (A) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R represents H, an alkyl group having 1 to 4 carbon atoms, a cycloalkyl group, an aryl group, or a substituted aryl group.) 5 to 60% by weight of a maleimide compound, 10 to 60% by weight of an aromatic vinyl compound 70% by weight, vinyl cyanide compound 5
~30% by weight, 20-70% by weight of alkyl methacrylate and 0-20% by weight of other monomers copolymerizable with these.
and the reduced viscosity of the methyl ethyl ketone soluble portion of the copolymer in dimethyl formamide solution at 30°C.
A maleimide copolymer having a concentration of 0.15 to 0.5 dl/g, (B) 40 to 90 weight % of a rubbery polymer is polymerized with 60 to 10 weight % of a monomer mixture consisting of the following formula group. A graft copolymer formed by g and h are vinyl cyanide compound (e) and alkyl (meth)acrylate (
f), an aromatic vinyl compound (g), and another vinyl compound (h) copolymerizable with these, and the numbers indicate the weight ratio (%) in the monomer mixture. ], (C) A vinyl chloride resin having a degree of polymerization of 400 to 800. 2. The maleimide copolymer (A) contains 5 to 60% by weight of N-phenylmaleimide, 10 to 70% by weight of styrene and/or α-methylstyrene, and 5 to 30% of acrylonitrile.
2. The flame-retardant resin composition according to claim 1, which is obtained by polymerizing 20 to 70 percent by weight of methyl methacrylate and 0 to 20 percent by weight of other monomers copolymerizable with these (total of 100 percent by weight). thing.