JPS6236443A - Production of flame-retardant styrene resin composition - Google Patents

Abstract

PURPOSE:To obtain the titled compsn. having excellent flame retardance and resistance to heat, impact and weather and useful as a housing material of electrical appliances, by melt-kneading a specified resin and a diol in a styrene resin in the presence of a catalyst. CONSTITUTION:0.1-10mol of an arom. diol contg. halogen (e.g. tetra bromobisphenol A) is blended with 1mol of a halogen-contg. epoxy resin of formula I (wherein R is a group of formula II or III; X is Br, Cl; i is 1-4; m is o or a natural number). 0.01-5wt% reaction accelerator such as an amine compd. as a reaction accelerating catalyst is added to the resulting blend. The mixture is melt-kneaded in a PS resin matrix to extend the molecular chain, thus obtaining a flame-retardant styrene resin compsn.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for producing a flame-retardant styrenic resin composition,
The purpose is to provide a method for producing a styrenic resin composition that has excellent heat resistance and impact resistance, good weather resistance, and high flame retardancy.

[Conventional technology and problems]

Styrenic resins are inexpensive and have excellent moldability, mechanical properties, electrical properties, and beautiful appearance, so they are widely used in various fields such as home appliances and furniture. However, since styrene-based resins are easily flammable, they are subject to many restrictions on use as various regulations regarding flame retardancy, such as UL standards, are strengthened or mandated.

Therefore, various methods for making styrene resin flame retardant have been studied, and it has been proposed to add inorganic compounds such as phosphorus compounds, halogen compounds, and antimony oxides as flame retardant agents. . Among these, halogen compounds are effective as flame retardants for styrene resins.
Among these, tetrabromobisphenol A1 decaproso diphenyl ether and brominated polycarbonate oligomers are known as those capable of imparting relatively high flame retardancy.

However, when tetrabromobisphenol A is used as a flame retardant, the heat resistance and thermal stability of the resin are significantly reduced. Japanese Unexamined Patent Application Publication No. 1996-11002 discloses a technique for overcoming such drawbacks of tetrabromobisphenol A.

However, from the table, it cannot be said that the heat resistance and thermal stability have been sufficiently solved.

Special public Akira! 2-32♂ Riza No. Publication, Special Publication Sho-t4-2!9
Publication No. 53 proposes a technique in which K decabromodiphenyl ether and brominated polycarbonate oligomer are used as flame retardants in order to improve the heat resistance and thermal stability of resins, but these flame retardants are not compatible with polystyrene resins. The compatibility is poor and there are problems with dispersibility, and a decline in the mechanical properties, especially the impact resistance, of the molded article is unavoidable. Furthermore, when decabromodiphenyl ether is used as a flame retardant, the weather resistance of the molded article is significantly reduced.

Japanese Patent Publication No. 191μr discloses a technique of adding a small amount of low molecular weight epoxy resin in order to prevent the decomposed melt from dripping during combustion, but the addition of such low molecular weight substances There is a risk that the heat resistance of

[Means for Solving the Problems] The present inventors have found that these problems have been solved, that is,
The present invention was completed as a result of extensive research aimed at obtaining a styrenic resin composition that has excellent heat resistance and impact resistance, good weather resistance, and a high degree of flame retardancy.

That is, the present invention provides a combination of a halogen-containing epoxy resin (g) and a halogen-containing aromatic diol in a styrene resin.
In the presence of a catalyst that promotes the reaction of
The present invention relates to a method for producing a flame-retardant styrenic resin composition, which is characterized in that it has a high molecular weight through melt mixing.

The styrenic resin in the present invention is a polymer containing an aromatic vinyl compound as a main component.

Specific examples include styrene monomers, α-substituted styrenes of α-methylstyrene, vinyltoluene, chlorostyrene, homopolymers of styrene derivative monomers such as styrene, as well as styrene-acrylonitrile copolymers, etc. Graft polymers obtained by graft polymerizing styrene monomers or other monomers to polybutadiene rubber (e.g., styrene graft polymers (HIPS resins), styrene-acrylonitrile graft polymers (ABS resins)
] and these styrene resins are blended with polybutadiene rubber.

The epoxy resin containing nitrogen in the present invention is generally represented by the following structural formula.

Or chlorine, i! −≠, and m is O or a natural number.

Specific examples include halogen-containing bisphenol A and/or
Or a reaction product having a terminal glycidyl ether group of halogen-containing bisphenol F and halogen-containing bisphenol A-type epoxy resin and/or halogen-containing bisphenol F-type epoxy resin, halogen-containing bisphenol A and/or halogen-containing bisphenol F, and epichlorohydrin in a conventional manner. This is a reaction product obtained by reacting according to the following.

Specific examples of halogen-containing bisphenol A and halogen-containing bisphenol F include tetrabromobisphenol A s dichlorobisphenol A1 tetrachlorobisphenol A1 dibromobisphenol A1 tetrabromobisphenol F, and the like. Specific examples of halogen-containing bisphenol A-type epoxy resins and halogen-containing bisphenol F-type epoxy resins include diglycidyl ether of tetrabromobisphenol A, diglycidyl ether of tetrachlorobisphenol A, diglycidyl ether of dichlorobisphenol A, and dibromobisphenol A diglycidyl ether. Examples include diglycidyl ether of bisphenol A and diglycidyl ether of tetrabromobisphenol F.

Particularly preferred is an epoxy resin obtained by reacting tetrabromobisphenol A and epichlorohydrin,
and an epoxy resin obtained by reacting the epoxy resin with tetrabromobisphenol A.

In the present invention, the halogen-containing aromatic diol is -
It is an aromatic compound that has two phenolic hydroxyl groups in its molecule and contains chlorine or bromine as other substituents.

Specific examples include tetrabromobisphenol A and dichlorobisphenol A.

Tetrachlorobisphenol A1 dipromopisphe/
-#A, polycarbonate oligomer of tetrabromobisphenol A, tetrabromobisphenol S
1-tetrabromobisphenol F, etc.

A particularly preferred aromatic diol containing tetrabromobisphenol A is tetrabromobisphenol A.

The catalyst used in the present invention is generally a compound that promotes the reaction between a phenolic OH group and an epoxy resin. Specific examples include hydroxides, carbonates, phosphates, silicates, and pisfelds of alkali metals and/or alkaline earth metals; other specific examples include amine compounds, ammonium compounds, amide compounds, and imidazoles. compounds, phosphonium salt compounds, phosphonium betaine, phosphonium, phosphine, sulfonium salts, ammonium salts, selenium salts, tellurium salts, tertiary bismuth compounds, tertiary antimony compounds, and the like.

The method for producing the composition of the present invention is characterized by increasing the molecular weight by melt-kneading a halogen-containing epoxy resin and a halogen-containing aromatic diol in a polystyrene resin matrix in the presence of a catalyst. .

The blending ratio of the halogen-containing epoxy resin and the halogen-containing aromatic diol can be changed arbitrarily, and if you want to increase the molecular weight of the flame retardant, the molar ratio of the two can be changed to /
This can be achieved by approaching K. Furthermore, if the number of moles of the halogen-containing epoxy resin is excessive relative to the diol, the epoxy group can remain in the flame retardant, and conversely, if the number of moles of the halogen-containing aromatic diol is excessive, the flame retardant A terminal OH group can remain.

The desired improvement in heat resistance cannot be achieved by using a halogen-containing epoxy resin alone or a halogen-containing aromatic diol alone.

A preferable ratio of the number of moles of the halogen-containing epoxy resin to the number of moles of the halogen-containing aromatic diol is in the range of o, i to IO.

There is no particular limit on the amount of polymerization catalyst added, but
The addition amount is preferably 0.0/~j% by weight based on the total amount of the halogen-containing epoxy resin and the halogen-containing aromatic diol.

Melt mixed wire has enough fluidity to uniformly mix a system containing a styrene resin, a halogen-containing epoxy resin, and a halogen-containing aromatic diol, and a system containing a halogen-containing epoxy resin and a halogen-containing aromatic diol. This is achieved by stirring the entire system at a temperature at which the diol can react in the presence of a catalyst.

Specific melt-kneading methods include melt extrusion methods, niegu methods, roll methods, and various types of mixers equipped with heating devices. In particular, a method using melt extrusion is advantageous in that blending and pelletizing the compound can be performed in one step.

There are no particular restrictions on the method of premixing the blend, and methods include methods using a Banbury mixer, a super mixer, a drum mixer, and the like.

It is also possible to add the oil medium and mix it before melting.
It can also be added during melt mixing.

In the case of cross-conducting by melt extrusion, it is also possible to add the catalyst from the pent part.

In addition, a master batch is prepared by blending a halogen-containing epoxy resin, an aromatic diol containing /-10 gen, and a catalyst into a styrene-based resin at a high concentration, and the master patch is mixed with the styrene-based resin blend system to perform melt mixing. It is also possible.

In the production method of the present invention, in addition to the 2-rogen-containing epoxy resin, the 2-rogen-containing aromatic diol, the catalyst, and the styrene resin, other types of flame retardants used in ordinary thermoplastic resins may be used as necessary. Flame retardant aids, e.g. 5b2
03, chlorinated polyethylene, etc. may be further added, and various additives such as ultraviolet absorbers, plasticizers, colorants, fillers, reinforcing agents, lubricants, stabilizers, etc. may be added.

〔Effect of the invention〕

The flame-retardant styrenic resin composition produced by the production method of the present invention has a high degree of flame retardancy even when molded as a thin plate of 6 inches, and has excellent heat resistance, impact resistance, and weather resistance, so it can be used as an industrial material. It is extremely useful, primarily as a connecting material for electrical equipment.

〔Example〕

The present invention will be explained below with reference to Examples and Comparative Examples, but the scope of the present invention is not limited thereto. In addition, evaluation of the molded sample was implemented by the following method.

Flame retardant: UL9≠Test method (A6 inch) Dirt impact test: Uses hemispherical steel with a diameter of 7.5 inches According to ASTM-1709 Heat distortion temperature: According to ASTM D-4 < zrK 1z
od impact test: Based on ASTM D-2zt Vicat softening point: Based on ASTM D-/YokojK Thermal stability: After staying in the cylinder (temperature 220°C) for 20 minutes, molding is performed and its appearance is observed.

○: No discoloration Δ: Slight yellowing ×: Yellowing Weather resistance: Observe the discoloration of the test piece after 200 hours of sunshine weather off-season.

○... No discoloration x... Yellowing Measuring method of molecular weight (My): Weight average molecular weight (Mw) is measured by gelpamienne chromatography based on a calibration curve using polystyrene as a standard material. did.

The specific conditions for measurement are shown below.

Column... A-403 (Showa tube! Kubu 1 gin gφX j00wnH8G-20 (Shimadzu ■yogφ×5ooranH8G-1! (//)
φ×jQQfRInH8G-10(1/), 1
A concatenation of μ pieces of 'φ×jOOTrr1n was used.

Solvent: Tetrahydrofuran Column temperature: θ℃ Transfer pressure: 3 μKi/d Flow rate: /,
Comparative Example 1-j Impact-resistant polystyrene (manufactured by Asahi Kasei Corporation, Styron QH-
≠0r) 100 parts by weight, a halogen-containing epoxy resin, a halogen-containing aromatic alcohol, and a polymerization catalyst were blended in the proportions shown in Table 1, mixed in a drum blender, and then subjected to twin-screw extrusion with a jOrtmφ pent. Pelletization was carried out at the same time as polymerization using a machine. The cylinder temperature is 21
At 0°C, the discharge amount was λO−λjKg/hr. Next, a test piece was prepared using an injection molding machine (1S-40k'' manufactured by Toshiba Corporation).

(Cylinder temperature is 2-0°C, mold temperature is 60°C.

) The results of measuring the physical properties of this test piece are shown in Table 1.

Example 6. Comparative example t ABS resin (manufactured by Asahi Kasei Co., Ltd., Stylac 7t3) io
o parts by weight of each component in the proportions shown in Table 7, test pieces were prepared in the same manner as in Example/-j, and the physical properties of the test pieces were measured. The results are shown in Table 1. It was shown to.

(Margin below)

Claims (1)

[Claims] (1) In a styrene resin, a halogen-containing epoxy resin (A) and a halogen-containing aromatic diol (B) are combined (A
1. A method for producing a flame-retardant styrenic resin composition, which comprises increasing the molecular weight by melt-kneading in the presence of a catalyst that promotes the reaction between ) and (B).