JPS5919148B2 - Flame retardant resin composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a flame-retardant resin composition containing styrene as a main component, and its purpose is to maintain the excellent properties of styrene-based resin while at the same time reducing the amount of decomposed molten material during combustion. An object of the present invention is to provide a resin composition that does not cause dripping and has high flame retardancy and heat resistance.

Styrenic resins are widely used in large quantities in various fields such as home appliances, buildings, and furniture because of their low cost, excellent molding process, mechanical properties, electrical properties, and beautiful appearance. However, since styrene resin is easily flammable,
As various regulations related to flame retardancy, such as UL standards, have been strengthened or made mandatory, many restrictions have been imposed on their use. Conventionally, methods have been studied or proposed to impart flame retardancy to styrene resins by adding various flame retardants such as halogenated organic compounds, halogenated phosphate ester compounds, and antimony compounds.

Although flame retardance can be achieved to a certain extent with these methods, it is not easy to prevent melt dripping during combustion. In order to prevent this melt dripping, attempts have been made to, for example, add inorganic compounds such as clay, talc, and glass fiber, crosslinking by radiation irradiation and addition of peroxide, and add polymeric substances such as vinyl chloride. However, a satisfactory method has not yet been found. Of course, this problem can be solved to some extent by significantly increasing the amount of the flame retardant added, but this results in a significant deterioration in the inherent physical properties of the resin and a significant increase in product price, making it extremely impractical. As a result of extensive research to solve these problems, the present inventor found that (2) 100 parts by weight of styrenic resin, (B) 5 to 20 parts by weight of a halogenated compound, and (C) a chlorine content of 20 parts by weight. ~50% chlorinated polyethylene 1-10 parts by weight, 0.2 times epoxy resin
By blending ~5 parts by weight and 2 to 10 parts by weight of (E) antimony trioxide, it maintains the excellent properties of styrenic resin, eliminates the dripping of melt during combustion, and has a high degree of flame retardancy. , found a composition having heat resistance,
This has led to the present invention.

The composition of the present invention does not cause any melt dripping, and has excellent flame retardancy and heat resistance. Surprisingly, the composition of the present invention is free from halogenated organic compounds, chlorinated polyethylene, etc. due to the presence of a suitable small amount of epoxy resin. This means that the total amount of antimony trioxide added can be significantly reduced.

The mechanism of action is not clear, but in addition to the flame retardant effect of the halogenated compound and antimony trioxide, it may also be due to the formation of a three-dimensional network structure due to the epoxy resin during molding or combustion. The composition of the present invention is a mixture of a styrene resin and the above four components, but the properties of each component alone do not increase additively, but each component is added and mixed within a certain range. By doing so, a synergistic effect is exhibited for the first time, and even with the addition of a small amount, properties such as preventing dripping of melts, flame retardance, and heat resistance are improved.

Therefore, it is an essential condition to add and mix the above four components into the styrene resin, and if even one component is missing, the effect can no longer be exhibited. The styrenic resin in the present invention refers not only to homopolymers of styrene monomers and styrene derivative monomers such as α-monosubstituted styrenes such as α-methylstyrene, vinyltoluene, and nuclear-substituted styrenes such as chlorostyrene; and other monomers, such as styrene-acrylonitrile copolymer (AS resin); Graft polymers obtained by graft polymerizing styrene monomer or other monomers to polybutadiene rubber, such as styrene graft polymer (
HIPS resin) Styrene; Acrylonitrile graft polymer (ABS resin): Furthermore, these styrene resins are blended with polybutadiene rubber.

Further, the halogenated organic compound used in the present invention preferably has a decomposition temperature of at least 230° C. or more, and specifically, tetrapromobisphenol A and its ether derivatives, polycarbonate of tetrabromobisphenol A, and tetrabromo anhydride. acids, brominated aromatic compounds such as decapromobiphenyl oxide, hexabromobenzene, pentapromotoluene, tetrapromobisphenol S, or halogens such as perchlorocyclopentadecane and its modifications, chlorendoic anhydride and its derivatives Examples include modified alicyclic compounds.

The purpose can be achieved by using these compounds alone or in combination of two or more. The blending ratio of the above compound to 100 parts by weight of the styrene resin is preferably 5 to 20 parts by weight, and if it is less than 5 parts by weight, the flame retardance will not be sufficient, and if it exceeds 20 parts by weight, the flame retardance will naturally improve, but On the contrary, various physical properties are deteriorated and it is not suitable from an economic point of view. The chlorinated polyethylene used in the present invention is polyethylene that has been chlorinated, and the polyethylene used as a raw material has a weight average molecular weight of 3.
It's ~200,000.

In addition, the chlorine content is 20 to 50%, preferably 30 to 4%.
0%, and the remaining polyethylene crystals are 20% or less of chlorinated polyethylene. If the chlorine content of chlorinated polyethylene is less than 20%, the ability to prevent melting and dripping during combustion will decrease, while if the chlorine content exceeds 50%, the polyethylene itself will become extremely rigid, resulting in a decrease in mechanical properties. has. Chlorinated polyethylene whose raw material polyethylene has a molecular weight of less than 30,000 has poor thermal stability and is insufficiently effective in preventing dripping of melt, and when the molecular weight of polyethylene is extremely large, compatibility is poor and processability is reduced. The compounding amount is
It is preferably 1 to 10 parts by weight based on 100 parts by weight of the resin.
If it is less than 1 part by weight, the melt dripping prevention property is insufficient, and if it exceeds 10 parts by weight, processability and heat resistance are poor, and expansion power and flame retardance are reduced. Examples of the epoxy resin used in the present invention include bisphenol type epoxy, halogenated bisphenol type epoxy, novolac type epoxy, and glycerin type epoxy, with bisphenol A epoxy resin and brominated bisphenol A epoxy resin being particularly preferred.

There is no limit to the degree of polymerization, epoxy equivalent, etc. of these epoxy resins, and epoxy resins with arbitrary properties may be selected in consideration of economic efficiency, workability, and the like. In addition, the blending amount is preferably 0.2 to 5 parts by weight per 100 parts by weight of the styrene resin; if it is less than 0.2 parts by weight, the drip prevention effect and heat resistance improvement will be insufficient, and the halogenated organic compound, The total amount of chlorinated polyethylene and antimony trioxide cannot be reduced. On the other hand, if the blending amount exceeds 5 parts by weight, impact resistance and flame retardance will deteriorate, which is not preferable.
The amount of antimony trioxide in the present invention is 100% of the resin.
The amount is preferably from 2 to 10 parts by weight, and if it is less than 2 parts by weight, the flame retardance will be insufficient, and if it exceeds 10 parts by weight, the physical properties will deteriorate, which is not preferred.

The method of blending the composition of the present invention is not particularly limited, and examples include methods using a tumbler mixer, super mixer, Nauta mixer, Banbury mixer, kneader, etc., methods using a roll, and methods using melt extrusion. Of course, various additives used in ordinary thermoplastic resins, such as ultraviolet absorbers, plasticizers, colorants, fillers, reinforcing agents, lubricants, stabilizers, etc., may be added to the composition of the present invention as necessary. You may do so. As described above, the present invention is extremely useful as an industrial material, mainly as a housing material for electrical equipment, as it has excellent physical properties, flame retardance, and heat resistance, and does not produce melted drippings during combustion, even if it is a small molded plate of % inches. The present invention provides a composition that provides a unique composition.

The present invention will be explained below with reference to Examples and Comparative Examples, but the scope of the present invention is not limited thereby.

The molded samples were evaluated according to the following method. Heat resistance: The hue of the molded sample plate (L/,
The hue (L) of the sample plate formed without staying with Al, b')
, a, b) were measured using a color difference meter, and the degree of discoloration was determined from Examples 1 to 3.
5 and Comparative Examples 1 to 4 Predetermined amounts of halogenated organic compound, chlorinated polyethylene, epoxy resin, and antimony trioxide were added to 100 parts by weight of impact-resistant polystyrene (Dialex HT-76: manufactured by Mitsubishi Monsanto) as shown in Table 1. After mixing in a blender, extrude at a temperature of 2 using a 301m extruder.
It was pelletized at 00°C.

Next, test pieces were prepared by injection molding at a molding temperature of 210° C., and a heat resistance test was conducted. The test pieces were subjected to combustion tests and physical property tests. The results are shown in Tables 1 and 2. Example 6 and Comparative Example 5 ABS resin (Sevian V-100: Daisel Co., Ltd.) was blended with each component in the proportions shown in Table 1, pelletized at 200°C, injection molded at 220°C, and carried out below. The same procedure as Examples 1 to 5 was carried out.

Claims (1)

[Claims] 1 (A) 100 parts by weight of styrene resin, (B) 5 to 20 parts by weight of halogenated organic compound, (C) chlorine content 2
1 to 10 parts by weight of 0 to 50% chlorinated polyethylene, (D
) A flame-retardant resin composition comprising 0.2 to 5 parts by weight of an epoxy resin and (E) 2 to 10 parts by weight of antimony trioxide.