JPH0678470B2 - Flame-retardant ABS resin composition - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flame-retardant ABS resin composition having excellent flame-retardant performance.

(Prior Art) In the field of housing materials for office equipment, demand for flame retardancy has been increasing in recent years. In particular, there is the Electrical Appliance and Material Control Law as a safety standard for electrical materials, and flammability tests are stipulated in the detailed rules for plastic materials. In the United States, UL standards (standards for flame retarding plastics for electrical equipment) have been established, and products for export to the United States require highly flame-retardant housing materials. Even for domestic products,
Under the influence of UL standards in the United States, flame retardant regulations tend to be tightened. Under such circumstances, there is a strong demand for a flame-retardant housing material.

Flame-retardant housing materials include, for example, Noryl (modified PPO). Noryl has mechanical strength, impact properties,
Although it has excellent heat resistance, it is expensive and has poor fluidity during molding. In recent years, ABS resin has been used as a housing material instead of Noryl. ABS resin has a good balance of physical properties, is inexpensive, and is easy to mold. However, since ABS resin easily burns, it is necessary to add a flame retardant to make it flame-retardant. Flame retardants are generally
Vinyl chloride polymers and low molecular weight halogen compounds are used. As an ABS resin containing such a halogen-based flame retardant, for example, in JP-A-54-40845, chlorinated polyethylene (chlorination degree 25 to 45%), tetrabromobisphenol A and antimony trichloride are added. Disclosed compositions are disclosed. Japanese Patent Laid-Open No. 54-43255 discloses ABS.
Compositions are disclosed in which polyvinyl chloride and antimony trioxide, or polyvinyl chloride and antimony pentoxide are added to a resin. However, as described above, the ABS resin flame-retarded with the halogen-based flame retardant generates hydrogen halide gas due to thermal decomposition of the halogen compound at the time of molding. Hydrogen halide gas is toxic to the human body. It may also cause discoloration of materials, inclusion of carbides, corrosion of screws and molding dies. If the molding temperature is lowered in order to prevent decomposition of the halogen compound, the fluidity of the resin will deteriorate. The ABS resin containing polyvinyl chloride has a significantly lower heat distortion temperature.

(Problems to be Solved by the Invention) The present invention is to solve the above-mentioned conventional problems, and an object thereof is to provide a flame-retardant ABS resin composition in which the flame-retardant agent is not thermally decomposed during molding. To provide things. Another object of the present invention is to provide a flame-retardant AB excellent in flame-retardant performance.
It is to provide an S resin composition.

(Means for Solving Problems) The flame-retardant ABS resin composition of the present invention comprises 100 parts by weight of ABS resin, 5 to 30 parts by weight of red phosphorus, 5 to 30 parts by weight of melamine, and 3 to 3 of the heat-crosslinkable curable resin. It contains 30 parts by weight, which achieves the above objectives.

ABS resin is a copolymer resin containing acrylonitrile, butadiene, and styrene as main components, and a polymer blend thereof. ABS resin is a blend type of styrene-acrylonitrile copolymer and acrylonitrile-butadiene rubber, and graft type obtained by graft-copolymerizing styrene and acrylonitrile in the presence of butadiene rubber latex or styrene-butadiene rubber latex. There is. In order to further improve heat resistance and fluidity, such ABS resin may be replaced with styrene by α-methylstyrene, or a monomer copolymerizable with styrene and acrylonitrile, such as methylmethacrylate, N-, may be used as a copolymerization component. Phenylmaleinimide may be introduced. It is also preferable to blend other resin components such as polycarbonate.

Red phosphorus is a flame retardant that forms a solid layer film on the combustion surface when ABS resin burns, thereby cutting off the supply of oxygen from the outside.

Generally, a phosphorus compound transforms metaphosphoric acid into polyphosphoric acid during its combustion. Polyphosphoric acid forms a solid film on the combustion surface, which interrupts the supply of oxygen from the outside. In addition, metaphosphoric acid exhibits a dehydrating action in the process of becoming polyphosphoric acid. Therefore, carbonization of the organic compound is promoted. This carbonized layer is also effective in blocking oxygen. Moreover, it is effective in preventing dripping of molten plastics during combustion.

Surface-treated red phosphorus particles are used for red phosphorus. The surface treatment is described in JP-A-51-105996 and JP-A-
As disclosed in JP-A-52-125489, it is performed by coating the surface of the red phosphorus fine particles with a thermosetting resin. By such surface treatment, alteration of red phosphorus fine particles due to moisture in the air is prevented, and danger in handling is also avoided. Red phosphorus particles are 5-30 per 100 parts by weight of ABS resin
It is contained in an amount of 10 parts by weight, preferably 10 to 20 parts by weight. If the amount is less than 5 parts by weight, the desired flame retardant performance cannot be obtained. If it exceeds 30 parts by weight, the flame retardant performance is rather deteriorated and the characteristics of the ABS resin are adversely affected.

Melamine is a flame retardant that blocks the supply of oxygen and prevents drip by condensing around the combustion temperature of ABS resin and taking a carbonized structure. The amino group in the melamine molecule traps free radicals during the oxidation reaction of the flammable gas to further promote flame retardation. Melamine is contained in an amount of 5 to 30 parts by weight, preferably 10 to 20 parts by weight, based on 100 parts by weight of ABS resin. 5
If it is less than the weight part, the desired flame retardant performance cannot be obtained. 30
If it exceeds the weight part, the flame retardant performance is rather deteriorated and the characteristics of the ABS resin are adversely affected.

The heat-crosslinking curable resin is a resole phenolic resin and polyacrylonitrile having a reactive methylol group, which can be cured by heat crosslinking and take a carbonized structure when the ABS resin is burned. Due to this carbonized structure, the supply of oxygen is cut off and the ABS resin becomes flame retardant. The carbonized structure also helps prevent drip.

As the resol-based phenol resin, a heat infusible or heat fusible granular phenol resin is used. The phenolic resin of the present invention further has a reactive methylol group. The content of methylol group is 3 to 15% by weight, preferably 5 to 10%.
% By weight. Moreover, the three-dimensional crosslink density is small. Therefore, the compatibility between the phenol resin and the ABS resin is improved. In addition, the condensation of the phenolic resin is promoted during the burning of the ABS resin, making it easier to form a carbonized structure.

Polyacrylonitrile can be obtained by a known polymerization method such as suspension polymerization or emulsion polymerization. The molecular weight is preferably 50,000 to 200,000. Polyacrylonitrile takes on a one-dimensional graphite structure by being cyclized by the heat of combustion. In addition, they condense between each graphite chain and form a graphite skeleton. This graphite skeleton cuts off the supply of oxygen and makes ABS resin flame-retardant. Instead of polyacrylonitrile, there are 10 monomers that can be copolymerized with acrylonitrile.
You may use the acrylonitrile copolymer contained in the range of weight% or less.

Such a heat-crosslinking curable resin is contained in an amount of 3 to 30 parts by weight, preferably 5 to 15 parts by weight, based on 100 parts by weight of ABS resin. If it is less than 3 parts by weight, the desired flame retardant performance cannot be obtained. If it exceeds 30 parts by weight, the flame retardant performance is rather deteriorated and the characteristics of the ABS resin are adversely affected.

The addition of such a flame retardant effectively makes the ABS resin composition of the present invention flame retardant. A composition obtained by adding a similar flame retardant to resins other than ABS resin is disclosed in
Although disclosed in Japanese Patent Publication No. 51-27461, the desired flame retardant performance cannot be obtained even if it is directly applied to ABS resin. As shown in the present invention, it is necessary to mix the flame retardant within a certain range.

(Examples) The present invention will be described below with reference to Examples.

Example 1 ABS resin (Psycholac EX-418, manufactured by Ube Cycon) 10
0 parts by weight, 10 parts by weight of red phosphorus fine particles surface-treated with thermosetting resin (Nova Red ^# 120, manufactured by Rin Kagaku Kogyo Co., Ltd.),
20 parts by weight of powdery melamine and 10 parts by weight of a phenol resin having a reactive methylol group (Bellpearl S-970, manufactured by Kanebo Co., Ltd.) were mixed and roll-kneaded at 180 to 185 ° C for 0.5 hour. The kneaded material was heated and pressed at 190 to 200 ° C to obtain a sheet having a thickness of 1.6 mm (1/16 inch). A test piece with a width of 12.7 mm was cut out from this sheet and subjected to a flame retardance test in accordance with the standards of US UL-94. The results are shown in the table below.

Example 2 A test piece was prepared in the same manner as in Example 1 except that the red phosphorus fine particles were 15 parts by weight and the phenol resin was 5 parts by weight.
The same combustion test was performed. The results are shown in the table below.

Example 3 15 parts by weight of red phosphorus fine particles, polyacrylonitrile instead of phenol resin (Toughtic B, manufactured by Nippon Exlan Co., Ltd.)
A test piece was prepared in the same manner as in Example 1 except that 5 parts by weight of was used, and the same burning test was performed. The results are shown in the table below.

Example 4 A test piece was prepared in the same manner as in Example 1 except that 15 parts by weight of red phosphorus fine particles, 10 parts by weight of melamine, and 5 parts by weight of phenol resin were used, and the same burning test was performed. The results are shown in the table below.

Example 5 A test piece was prepared in the same manner as in Example 1 except that 20 parts by weight of red phosphorus fine particles, 10 parts by weight of melamine, and 5 parts by weight of phenol resin were used, and the same burning test was performed. The results are shown in the table below.

Comparative Example 1 A test piece was prepared in the same manner as in Example 1 except that melamine and phenol resin were not used, and the same burning test was performed. The results are shown in the table below.

Comparative Example 2 A test piece was prepared in the same manner as in Example 1 except that the phenol resin was not used, and the same burning test was performed. The results are shown in the table below.

Comparative Example 3 A test piece was prepared in the same manner as in Example 1 except that 15 parts by weight of red phosphorus fine particles and 15 parts by weight of phenol resin were used and no melamine was used, and the same burning test was performed. The results are shown in the table below.

Comparative Example 4 A test piece was prepared in the same manner as in Example 1 except that 35 parts by weight of red phosphorus fine particles, 10 parts by weight of melamine, and 5 parts by weight of phenol resin were used, and the same burning test was performed. The results are shown in the table below.

As is clear from the table, by adding 10 to 20 parts by weight of red phosphorus fine particles, 10 to 20 parts by weight of melamine, and 5 to 10 parts by weight of the heat-crosslinking curable resin to 100 parts by weight of ABS resin, the UL
Excellent flame retardancy of -94 standards V-O to V-1 was obtained. Considering other experimental data by the present inventor,
If the composition of the present invention is in the range of 5 to 30 parts by weight of red phosphorus fine particles, 5 to 30 parts by weight of melamine, and 3 to 30 parts by weight of a heat-crosslinking curable resin, the composition is desired with respect to 100 parts by weight of ABS resin. It has been revealed that it can have excellent flame retardancy.

As shown in Comparative Examples 1 to 3, even if any one of these additives is lacking, remarkably low flame retardant performance such as UL-94 standard notV can be obtained. In addition, as shown in Comparative Example 4,
Even if the amount of the additive deviates from the above range, the flame retardant performance is deteriorated.

(Effect of the Invention) Since the flame-retardant ABS resin composition of the present invention thus uses the flame retardant other than the halogen compound, the flame retardant does not decompose thermally during its molding. As a result, generation of toxic gas, discoloration of material, mixing of carbide, corrosion of screw and molding die does not occur. Therefore, the composition of the present invention is useful as a flame retardant material.

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Claims (2)

[Claims] 1. ABS resin 100 parts by weight, red phosphorus 5 to 30 parts by weight,
Thermal cross-linking curable resin 3 to 5 which is at least one of a resole phenolic resin having 5 to 30 parts by weight of melamine and a reactive methylol group and polyacrylonitrile
Flame-retardant ABS resin composition containing 30 parts by weight. 2. The flame-retardant ABS resin composition according to claim 1, wherein the red phosphorus is fine particles of red phosphorus surface-treated with a thermosetting resin.