JPH06884B2 - Flame-retardant resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel flame retardant resin composition. More specifically, it relates to a flame-retardant resin composition which is made of ABS resin, vinyl chloride resin and other synthetic resins and is excellent in processability, impact resistance and thermal stability.

[Conventional technology]

Conventionally, high-impact polystyrene resins and acrylonitrile-based thermoplastic resins that are used in the fields of electric equipment parts, automobile parts, building materials, etc. have the characteristics of excellent impact resistance and rigidity, and extremely good moldability. A rubber-containing impact-resistant polystyrene-based resin such as a butadiene-styrene copolymer (hereinafter referred to as ABS resin) has been often used.

However, for the resins used in this field in recent years,
Higher flame-retardant properties are required, and to some extent, the development of higher flame-retardant resins in place of the above-mentioned polystyrene resins, which are flammable, is desired. Things have been proposed.

For example, there is a flame-retardant resin composition containing a low-molecular-weight flame retardant represented by a phosphorus-containing compound such as a halogenated ester, an aromatic halogen-containing compound, a phosphoric acid ester, or a halogenated phosphoric acid ester.

However, since these flame retardants are chemically unstable low molecular weight compounds and must be added in a considerable amount in order to impart a high degree of flame retardancy to the resin, the mechanical strength of the resin, Above all, it causes a significant drop in impact strength,
Molding processability is hindered by coloring caused by thermal decomposition during molding process, and weather resistance is significantly deteriorated.
In many cases, the commercial value of the product is impaired.Furthermore, since flame retardants are generally expensive, they have the drawbacks of significantly increasing the cost of the product. It is difficult to obtain a resin that can be used for.

On the other hand, focusing on the fact that it is easy to obtain a high degree of balance between flame retardancy and impact strength, flame retardancy obtained recently by mixing halogen-containing compounds such as polyvinyl chloride resin and chlorinated polyethylene with other resins. Many resin compositions have been proposed.

For example, a flame-retardant resin composition comprising a polyvinyl chloride resin and an ABS resin is known (Japanese Patent Publication No. 48-528).

The resin composition is derived from the properties of the polyvinyl chloride resin, and certainly has excellent mechanical strength such as impact strength and rigidity, and a resin having a high degree of flame retardancy can be obtained, but the polyvinyl chloride resin is chemically Since the resin composition is poor in thermal stability because it is unstable in nature and is prone to thermal decomposition, the moldability is remarkably lowered in combination with the poor fluidity of the polyvinyl chloride resin. Have

On the other hand, it is obvious that a heat stabilizer such as a lead-based compound or a tin-based compound is added to improve molding processability by increasing the thermal stability of polyvinyl chloride, but The amount used is naturally limited due to the important effects on liquidity and physical properties and cost.

Also known is a method of improving the molding processability of polyvinyl chloride by reducing the content of molecules having an asymmetric structure (branching, double bond, etc.) in the polymer by ionic polymerization or the like. However, there is a problem in the factory in terms of polymerization rate and yield. Furthermore, as a method of improving the resin moldability, there is a method of increasing the resin fluidity and suppressing the molding temperature to enhance the thermal stability of the resin. Is likely to decrease, and a sufficient effect cannot be obtained.

On the other hand, a flame-retardant resin composition (US Pat. No. 3494982) composed of chlorinated polyethylene and ABS resin is also known. This composition has a slightly better thermal stability than the polyvinyl chloride resin composition, but has the drawback of poor moldability due to poor flowability.

As described above, no conventional flame-retardant resin composition has been found to have practical value as a molding material that simultaneously satisfies heavy molding processability, impact resistance, and weather resistance as commercial values.

[Problems to be solved by the invention]

An object of the present invention is to provide a flame-retardant resin composition that has molding processability that can be put to practical use as a molding material that has been difficult with conventional compositions, and that also has impact resistance. .

[Means for solving problems]

The present inventor has conducted extensive studies to solve the above-mentioned problems, and as a result, by combining an ABS resin with a specific vinyl chloride resin and further adding a synthetic resin, excellent workability, impact resistance, and thermal stability were obtained. The inventors have reached the present invention by finding that a flammable resin composition can be obtained.

That is, the resin composition of the present invention has a secondary rearrangement point of −10 ° C. when A) 20 to 69% by weight of ABS resin and B) homopolymer are used.
Copolymer of 60 to 95 parts by weight of the following alkyl acrylate and / or alkyl methacrylate and 5 to 40 parts by weight of monomers having a secondary rearrangement point of the homopolymer of 0 ° C or higher
(b) -1, when it is a homopolymer, its secondary rearrangement point is -1
70-99 parts by weight of alkyl acrylate and / or alkyl methacrylate having a temperature of 0 ° C. or less and a polyfunctional monomer 1
To 30 parts by weight of copolymer (b) -2, a homopolymer having a secondary rearrangement point of −10 ° C. or less, and 60 to 90 parts by weight of an alkyl acrylate and / or alkyl methacrylate and a homopolymer One or more acrylic copolymers selected from the copolymer (b) -3 of 5 to 39 parts by weight of monomers having a next rearrangement point of 0 ° C. or more and 1 to 30 parts by weight of a polyfunctional monomer. Vinyl chloride resin obtained by graft-copolymerizing 70 to 99 parts by weight of vinyl chloride with 1 to 30 parts by weight of polymer 30 to 80
Wt% and C) Acrylonitrile-styrene polymer, methyl methacrylate-styrene copolymer, polymethylmethacrylate, polystyrene, polyacrylate, acrylonitrile-butadiene rubber, chlorinated polyethylene, polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, Acrylonitrile-acrylic rubber-styrene copolymer, ethylene-vinyl acetate-
One or more synthetic resins selected from vinyl chloride copolymer, acrylonitrile-chlorinated polyethylene-styrene copolymer, polyurethane, chloroprene rubber 1
-20% by weight.

The details will be described below.

The content of ABS resin in the flame-retardant resin composition of the present invention is 20-
It is 69% by weight, but 30 to 65% by weight is particularly preferable. If it is less than 20% by weight, the workability is poor, and if it exceeds 69% by weight, it is difficult to maintain flame retardancy.

Polybutadiene rubber, which is a raw material for ABS resin polymerization,
Polybutadiene or 50% by weight or more of butadiene and 50% by weight or less of a monoolefin monomer copolymerizable therewith, aromatic vinyl compounds such as styrene, alkyl acrylates such as methyl acrylate, ethyl acrylate and butyl acrylate; methyl methacrylate , An alkyl methacrylate such as ethyl methacrylate and butyl methacrylate; a copolymer with a vinyl cyanide compound such as acrylonitrile.

The vinyl cyanide compound used in the ABS resin graft polymerization is acrylonitrile, methacrylonitrile or the like, and the aromatic vinyl compound is styrene or α.
-Methyl styrene, chlorostyrene and the like are typical, and the use ratio is preferably 10 to 50 parts by weight of vinyl cyanide compound and 10 to 50 parts by weight of aromatic vinyl compound to 10 to 50 parts by weight of the butadiene rubber. .

In the graft polymerization, a small amount of vinyl monomers copolymerizable with vinyl cyanide compounds and aromatic vinyl compounds can be used.

Any of the above-mentioned polymerizations can be easily carried out by a conventionally known method such as suspension polymerization and emulsion polymerization, but emulsion polymerization is particularly preferable.

The content of the vinyl chloride resin in the flame-retardant resin composition of the present invention is 30 to 80% by weight, preferably 40 to 70% by weight.

When the content of the vinyl chloride resin exceeds 80% by weight, the impact strength and molding processability of the resin composition are deteriorated, which is not desirable. On the other hand, if the content is less than 30% by weight, the high flame retardancy targeted by the present invention cannot be obtained.

The vinyl chloride resin used in the present invention comprises one or more selected from the following three acrylic copolymers (b) -1, (b) -2 and (b) -3 and vinyl chloride. Obtained by graft polymerization.

The acrylic polymer (b) -1 is a copolymer of alkyl acrylate and / or alkyl methacrylate and other monomers. Alkyl acrylate and alkyl methacrylate are homopolymers,
It has a second-order transition point of −10 ° C. or lower, and is, for example, ethyl acrylate, n-propyl acrylate, iso-butyl acrylate, n-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n.
-Octyl acrylate, n-decyl acrylate, and n-octyl methacrylate, n-decyl methacrylate, n-dodecyl methacrylate, lauryl methacrylate and the like are included, which contribute to impact resistance.

Alkyl acrylate and / or alkyl methacrylate acts as a soft segment, and the amount used is 60 per 100 parts by weight of the total amount with other monomers as copolymerization raw materials.
The amount is preferably up to 95 parts by weight, and if it exceeds 95 parts by weight, no improvement in strength can be expected, and if it is less than 60 parts by weight, impact resistance decreases, which is not preferable.

When the monomers are homopolymers, their secondary rearrangement points are 0 ° C. or higher. For example, aromatic vinyls such as styrene, α-methylstyrene and vinyltoluene,
Unsaturated nitriles such as acrylonitrile and methacrylonitrile, vinyl acetates such as vinyl acetate and vinyl propionate, vinyl ethers such as butyl vinyl ether, octyl vinyl ether and lauryl vinyl ether, alkyl acrylates of methyl acrylate,
Examples thereof include alkylmethacrylates such as methylmethacrylate, ethylmethacrylate, propylmethacrylate and the like, which function as hard segments by copolymerization and are used alone or in a mixture of two or more kinds.

The amount of monomers used is preferably 5 to 40 parts by weight.
If it is less than part by weight, the strength cannot be expected to be improved, and if it exceeds 40 parts by weight, impact resistance is lowered, which is not preferable. Methyl methacrylate, methyl acrylate, acrylonitrile, and styrene are preferable especially when improvement in strength is expected.

The copolymer of the alkyl acrylate and / or the alkyl methacrylate used in the present invention and the monomers may be a generally known emulsifier, dispersant, catalyst or the like by a polymerization method such as emulsion polymerization, suspension polymerization, solution polymerization or bulk polymerization. It is obtained by using, but it is particularly preferable to employ emulsion polymerization.

The acrylic polymer (b) -2 is a copolymer of an alkyl acrylate and / or an alkyl methacrylate and a polyfunctional monomer. Alkyl acrylate and / or alkyl methacrylate is a monomer whose secondary transition point is -10 ° C or less when formed into a homopolymer,
For example, ethyl acrylate, n-propyl acrylate, iso-butyl acrylate, n-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-decyl acrylate and n-octyl methacrylate, n-decyl methacrylate, n. -Dodecyl methacrylate, lauryl methacrylate, etc. are mentioned, which contribute to impact resistance.

The amount of the alkyl acrylate and / or the alkyl methacrylate to be used is preferably 99 to 70 parts by weight per 100 parts by weight of the total amount of the polyfunctional monomer which is another copolymerization raw material, and 99 parts by weight or more improves the strength. If the amount is less than 70 parts by weight, the impact resistance decreases, which is not preferable.

The polyfunctional monomer is an alkyl acrylate and / or
Or a monomer that causes cross-linking or the like in alkyl methacrylate, such as ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3-
Propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate etc. Mono or polyalkylene glycol acrylates or methacrylates, diallyl phthalate, diallyl malate, diallyl fumarate, diallyl succinate, etc. Examples thereof include di- or triallyl compounds and divinylbenzene.

The polyfunctional monomer is preferably used in an amount of 1 to 30 parts by weight. If it is less than 1 part by weight, the strength cannot be improved, and if it is 30 parts by weight or more, the impact resistance decreases, which is not preferable.

The copolymer of alkyl acrylate and / or alkyl methacrylate and a polyfunctional monomer is prepared by using a generally known emulsifier, dispersant, catalyst or the like by a polymerization method such as emulsion polymerization, suspension polymerization, solution polymerization or bulk polymerization. Although obtained, it is preferable to employ emulsion polymerization.

The acrylic polymer (b) -3 is a copolymer of alkyl acrylate and / or alkyl methacrylate, other monomers, and polyfunctional monomers. Alkyl acrylate and / or alkyl methacrylate has a secondary transition point of -10 when formed into a homopolymer.
C. or less, such as ethyl acrylate, n-propyl acrylate, iso-butyl acrylate, n-butyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-decyl acrylate, and n-octyl methacrylate. , N-decylmethacrylate, n-dodecylmethacrylate, laurylmethacrylate, etc. are mentioned, which contribute to impact resistance.

Alkyl acrylate and / or alkyl methacrylate functions as a soft segment, and the amount thereof is preferably 60 to 90 parts by weight based on 100 parts by weight of the total amount of raw materials used for copolymerization, and if the amount exceeds 90 parts by weight, improvement in strength cannot be expected. If it is less than part by weight, the impact resistance is lowered, which is not preferable.

When the monomers are homopolymers, they have a secondary rearrangement point of 0 ° C. or higher, and they function as a hard segment by copolymerization. For example, aromatic vinyls such as styrene, α-methylstyrene, vinyltoluene, and acrylonitrile. Unsaturated nitriles such as methacrylonitrile, vinyl acetates such as vinyl acetate and vinyl propionate, vinyl ethers such as butyl vinyl ether, octyl vinyl ether and lauryl vinyl ether,
Examples thereof include alkyl acrylates of methyl acrylate, methyl acrylate, ethyl methacrylate, and alkyl methacrylates such as propyl methacrylate. These may be used alone or in a mixture of two or more.

The amount of monomers used is preferably 5 to 40 parts by weight.
If it is less than part by weight, the strength cannot be expected to be improved, and if it exceeds 40 parts by weight, impact resistance is lowered, which is not preferable. Methyl methacrylate, methyl acrylate, acrylonitrile, and styrene are preferable especially when improvement in strength is expected.

The polyfunctional monomer is an alkyl acrylate and / or
Or a monomer that causes cross-linking or the like in alkyl methacrylate, such as ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, 1,3-
Propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylate etc. Mono or polyalkylene glycol acrylates or methacrylates, diallyl phthalate, diallyl malate, diallyl fumarate, diallyl succinate, etc. Examples thereof include di- or triallyl compounds and divinylbenzene.

The amount of the polyfunctional monomer used is preferably from 1 to 30 parts by weight. If it is less than 1 part by weight, the strength cannot be expected to be improved, and if it exceeds 30 parts by weight, the impact resistance is not improved.

The copolymer of the alkyl acrylate and / or alkyl methacrylate used in the present invention and the monomer and the polyfunctional monomer is a generally known emulsifier by a polymerization method such as emulsion polymerization, suspension polymerization, solution polymerization or bulk polymerization. It can be obtained by using a dispersant, a catalyst, a molecular weight modifier and the like, but it is preferable to employ emulsion polymerization.

The amount of the acrylic copolymer used as the trunk polymer of the graft copolymerization for obtaining the vinyl chloride resin of the present invention is 100 parts by weight in total with the amount of vinyl chloride which is another raw material of the graft copolymerization. Amounts of use of 1 to 30 parts by weight are suitable. When the amount of the acrylic copolymer used is less than 1 part by weight, the impact resistance is insufficient, and when it exceeds 30 parts by weight, the impact resistance is improved but the strength is lowered, which is not preferable.

As a polymerization method for obtaining the vinyl chloride resin of the present invention, any known method can be used. Examples thereof include an aqueous suspension polymerization method, an aqueous emulsion polymerization method, a solution polymerization method and a solventless polymerization method, and the aqueous suspension polymerization method is preferable.

Moreover, in obtaining vinyl chloride resin, molding processability,
Other monomers may coexist as long as the characteristics of the resin composition of the present invention such as impact resistance are not changed.

The synthetic resin used in the present invention is used for the purpose of improving processability, accelerating gelation, improving secondary processability, strengthening impact resistance, enhancing physical properties at low temperature, accelerating fluidity, etc. Improvements and improvements in physical properties can be made. Any of these synthetic resins may be a commercially available synthetic resin. The amount used can be within the range that does not impair molding processability, impact resistance, and flame retardancy. The content is preferably 20% by weight or less, and if it is less than 1% by weight, the effect cannot be exhibited.

Examples of the synthetic resin used in the present invention include acrylonitrile-styrene polymer, methyl methacrylate-styrene copolymer, polymethyl methacrylate, polystyrene, polyacrylate, acrylonitrile-butadiene rubber, chlorinated polyethylene, polyethylene, ethylene-vinyl acetate copolymer, ethylene- Ethyl acrylate copolymer, acrylonitrile-acrylic rubber-styrene copolymer, ethylene-vinyl acetate-vinyl chloride copolymer, acrylonitrile-chlorinated polyethylene-styrene copolymer, polyurethane, chloroprene rubber, and one or two selected from these The above synthetic resins can be used.

The resin composition of the present invention may optionally contain other additives such as a flame retardant, an ultraviolet absorber, an antioxidant, a colorant, a lubricant and a heat stabilizer.

The resin composition of the present invention is a mixing roll, a co-kneader,
It is easily melt-mixed by a kneading machine such as a Banbury mixer or an extruder.

The resin composition of the present invention thus obtained can be widely used in the fields of electric parts, automobile parts, building materials, office equipment parts and the like, which require high flame retardancy.

The present invention will be described in detail below with reference to examples and reference examples.

Each physical property value in the present invention was measured by the following methods.

(1) Measurement of molding processability (fluidity) Using 1g of extruded pellets, using a die with an inner diameter of 1mm and a length of 10mm, under the conditions of pressure 150kg / cm ² and temperature 200 ° C, using an advanced flow tester. The flow rate was measured.

(2) Measurement of molding processability (thermal stability) (2) -1 CR thermal stability test (static thermal stability) Time (minutes) until decomposition starts according to JIS K-6723 method
Was measured. However, the temperature was 200 ° C.

(2) -2 Dynamic Thermal Stability 32 g of extrusion pellets were placed in a rotor mixer with an internal volume of 30 cc and a batch type plastograph at a temperature of 190 ° C, and the rotation speed was 50.
After kneading under the conditions of rpm and a load of 10.0 kg, the time (minutes) from when the torque decreased to a steady state to when it started to increase again was measured.

(3) Impact strength measurement According to ASTM-256 method, injection molding temperature 18 with 4OZ injection molding machine
Izod impact strength was measured using an Izod impact test piece obtained by molding under conditions of 0 °, 200 °, 200 ° C and a molding cycle of 1 minute. However, a notch was used for the notch.

(4) Flame retardant UL-94 method sample thickness 1/8 inch test piece used.

〔Example〕

Examples 1 to 7 and Reference Examples 1 to 11 (1) Production of ABS Resin Emulsion polymerization was carried out at 60 ° C. based on the amounts of raw materials used shown in Table 1 to obtain polymers (A) -1 to 10. The composition of the solid polybutadiene latex used is as follows.

PB-1 …… Butadiene content 100% (wt%, same below) PB-2 …… Butadiene content 60%, Styrene content 40% PB-3 …… Butadiene content 60%, Acrylonitrile content 40% PB-4 …… Butadiene 40% min, 40% styrene, 20% acrylonitrile The amounts of raw materials used in Table 1 are parts by weight (the same applies to Table 2 and below).

(2) Production of vinyl chloride resin Based on the amounts of raw materials shown in Table 2, aqueous suspension polymerization was carried out at 63 ° C to obtain polymers (B) -1 to 10.

The secondary transition temperature of the acrylic resin homopolymer is as follows.

Poly-n-butyl acrylate …… -56 ℃ Poly-2-ethylhexyl acrylate …… -20 ℃ Methyl acrylate …… 0 ℃ Methyl methacrylate …… 45 ℃ (3) Production of resin composition of the present invention The resin component obtained in (1) above, and the resin component and synthetic resin component obtained in (2) above are more stable at the ratios shown in Table 3. 2.5 parts by weight of dibutyltin mercaptide as an agent
Supermixer (manufactured by Kawata Manufacturing Co., Ltd.) was mixed at 90 ° C. for 10 minutes, and then melt-kneaded at 200 ° C. with a 40 mmφ extruder to form pellets.

Next, a test piece for measuring physical properties was prepared using a 4-ounce injection molding machine. In this case, the molding temperature is 18 cylinder temperature.
The temperature was set to 0, 200, 200 ° C. Using the pellets and test pieces thus obtained, the above-mentioned various physical property tests were conducted.

The evaluation results are shown in Tables 3 and 4 together with the following reference examples.

As is clear from Tables 3 and 4, the composition of the present invention is excellent in processability, physical strength, and flame retardancy.

[Effects of the Invention] As described in detail above, the present invention provides a flame-retardant resin composition excellent in processability, impact resistance, and thermal stability, and improves the quality of the flame-retardant resin and expands the use thereof. The contribution is extremely large.

Claims (1)

[Claims] 1. When A) 20 to 69% by weight of ABS resin and B) homopolymer are used, the secondary rearrangement point thereof is -10 ° C.
Copolymer (b) -1, with 60 to 95 parts by weight of the following alkyl acrylate and / or alkyl methacrylate and 5 to 40 parts by weight of monomers having a secondary rearrangement point of 0 ° C. or more, when made into a homopolymer: A copolymer (b) -2 of 70 to 99 parts by weight of an alkyl acrylate and / or an alkyl methacrylate having a secondary rearrangement point of −10 ° C. or less when used as a homopolymer and 1 to 30 parts by weight of a polyfunctional monomer. , 60 to 90 parts by weight of alkyl acrylate and / or alkyl methacrylate having a secondary rearrangement point of −10 ° C. or lower when used as a homopolymer and monomers having a secondary rearrangement point of 0 ° C. or higher when used as a homopolymer 5 ~ 39 parts by weight of a polyfunctional monomer 1 to 30 parts by weight of a copolymer (b) -3 or one or more kinds of acrylic copolymer selected from 1 to 30 parts by weight of vinyl chloride 70 ~ 99 Graft copolymerization of parts by weight C) acrylonitrile-styrene polymer, methyl methacrylate-styrene copolymer, polymethylmethacrylate, polystyrene, polyacrylate, acrylonitrile-butadiene rubber, chlorinated polyethylene, polyethylene, ethylene -Vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, acrylonitrile-acrylic rubber-styrene copolymer, ethylene-vinyl acetate-
One or more synthetic resins selected from vinyl chloride copolymer, acrylonitrile-chlorinated polyethylene-styrene copolymer, polyurethane, chloroprene rubber 1
A novel flame-retardant resin composition comprising about 20% by weight.