JPH0657044A - Production of flame-retardant resin composition - Google Patents

Abstract

PURPOSE:To obtain the resin composition excellent in blooming resistance and thermal stability and useful for automobile parts, etc., by blending a composition obtained by kneading a PS resin with decabromodiphenyl ether in a specific ratio with a specific amount of polyolefin resin and a specific amount of antimony trioxide. CONSTITUTION:The resin composition is obtained by blending (A) 2-30wt.% composition obtained by previously kneading (i) 10-90wt.% PS resin with (ii) 90-10wt.% decabromodiphenyl ether at 210-290 deg.C with (B) 60-97wt.% polyolefin resin such as PE and (C) 0.5-20wt.% antimony trioxide.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a flame-retardant resin composition. More specifically, the present invention relates to a method for producing a flame-retardant resin composition characterized by improving blooming resistance of a product.

[0002]

2. Description of the Related Art Crystalline resins are widely used in the fields of automobiles, building materials, electric parts and the like in the form of injection molded products, films, sheets and blow molded products by taking advantage of their excellent characteristics. However, a resin which is an organic polymer has a drawback that it is extremely flammable, and the demand for flame retardancy is increasing as its applications are widespread.

To make these organic polymers flame-retardant, (1) add a flame retardant to the resin, (2) blend a flame-retardant resin,
(3) It is carried out by a method of producing a flame-retardant polymer by a reaction with a flame-retardant monomer.

Among these methods, a method generally used is a method of adding a flame retardant to a resin, and many resins are used by this method. Further, as the flame retardant used for these, halides such as organic chlorides and bromides, phosphoric acid esters, phosphorous acid esters, phosphorus-containing compounds such as phosphorus, water-containing inorganic compounds, and as flame retardant aids Antimony oxide is commonly used. In particular, organic halogen-based flame retardant decabromodiphenyl ether has a high flame-retardant effect and is widely used as a flame-retardant for polyolefin resins.

[0005]

However, the flame-retardant resin compositions prepared by adding these flame-retardants have their respective drawbacks. For example, a flame-retardant resin prepared by adding decabromodiphenyl ether, which is an organic halogen-based flame retardant, is likely to cause blooming. Particularly, in the case of a polyolefin resin, the processability decreases due to plate-out during processing, and bleeding during use Appears, making the image of the product worse. Further, the phosphorus-based compound has a flame-retardant effect only on a specific resin, and has poor compatibility with the resin, and blooming easily occurs. Further, although the water-containing inorganic compound is regarded as a promising non-halogen flame retardant, it has a small flame retarding effect and also significantly impairs the physical properties of the resin.

Several methods have been proposed to remedy the drawbacks of organic halides. For example, as a method of suppressing blooming, a method of adding a flame retardant having a polar group to its basic structure (for example, JP-A-61-168643) or a method of brominated a relatively high molecular weight oligomer (for example, Japanese Patent Publication No. 57-26305).
However, even in the former case, the suppression of blooming is not complete, and blooming occurs during use as a product, which not only causes troubles but also extremely causes a fire drop. Further, in the latter, although blooming can be suppressed, it has a drawback that the flame retardant effect is inferior.

[0007]

Means for Solving the Problems As a result of intensive studies to develop a good flame-retardant resin composition, the present inventors have previously found that polystyrene resin 10 to 90 wt% and decabromodiphenyl ether 90 to 10 wt%. 210 to 2
By blending 2 to 30 wt% of the composition obtained by kneading at 90 ° C. with 60 to 97 wt% of a polyolefin resin and 0.5 to 20 wt% of antimony trioxide,
It has been found that a flame-retardant resin composition excellent in blooming resistance and thermal stability can be prepared.

Various polystyrene resins can be used in the present invention. The polystyrene resin used here can be polystyrene, impact-resistant polystyrene, or other styrene copolymer such as styrene-acrylonitrile copolymer, and if it is usually used for molding, it is special. There are no restrictions.

The addition amount of decabromodiphenyl ether in the polystyrene resin used in the present invention is 10 to 90 wt%.
It is preferably 20 to 80 wt%. Addition amount is 10wt
If it is less than%, the amount of the masterbatch added increases and the physical properties of the product are impaired. If it exceeds 90 wt%, it is difficult to form a masterbatch.

The processing temperature for preparing the masterbatch is 210 to 290 ° C, preferably 230 to 270 ° C. When the processing temperature is lower than 210 ° C, the flame retardant is poorly dispersed, and when the processing temperature exceeds 290 ° C, decomposition of the flame retardant and the resin begins.

The masterbatch can be prepared by mixing using a conventional mixing device such as a Henschel mixer or a ribbon blender and using a conventional single-screw extruder, twin-screw extruder or pressure kneader.

The amount of the flame-retardant masterbatch thus prepared varies depending on the required level of flame retardancy, but is 2 to 30 wt%, preferably 4 to 30 wt%. If the amount added is less than 2 wt%, the flame retardancy is poor, and if it exceeds 30 wt%, the physical properties of the polyolefin resin deteriorate.

Various polyolefin resins can be used in the present invention. The polyolefin resin used here includes polyethylene, polypropylene, and ethylene-
Vinyl acetate copolymers, polyethylene-polypropylene copolymers and mixtures thereof can be used. These resins are not particularly limited as long as they are resins that can normally be used for molding, and are not affected by melt index, density, type and amount of catalyst residue.

The amount of antimony trioxide added has a strong relationship with the amount of halogen added, and is preferably 0.5 to 20 wt%, more preferably 1 to 15 wt%. If it is less than this range, the flame retardant synergistic effect is not recognized, and if it is more than that, the physical properties of the resin deteriorate.

In the present invention, an inorganic flame retardant and a phosphorus flame retardant may be used in combination, or if they are used to the extent that the physical properties are not deteriorated.

Further, in the present invention, a substance which is usually used as a flame retardant aid, for example, zinc borate can be used in combination.
Addition of these improves flame retardancy and suppresses glowing.

It is also possible to improve the physical properties of the present invention by using an inorganic filler in combination. For these purposes,
Talc, mica, silica, calcium silicate, glass fiber, carbon fiber, calcium carbonate and the like are used.

In the present invention, in addition to the above, those usually used as additives for polyolefin resins, for example, antioxidants, light stabilizers, ultraviolet absorbers and stabilizers can be added.

The flame-retardant polyolefin resin composition thus obtained can be formed into a molded product by a usual processing method such as injection molding, extrusion molding, blow molding and the like.

[0020]

The present invention will be described in detail below with reference to examples, but the present invention is not limited to these.
Various test methods carried out in Examples and Comparative Examples are as follows. -Flame retardancy test According to JIS K7201 "Combustion test method for polymer materials by oxygen index method". The test piece was prepared using an injection molding machine. -Plateout test and blooming test A flat plate of 100 x 65 x 3 mm was prepared using an injection molding machine. At this time, the presence or absence of the plate ant was determined by the degree of cloudiness of the mold. The flat plate was heated in a gear oven at 100 ° C. for 168 hours, then taken out and visually checked for blooming. -Thermal stability The test piece as described above was placed in a gear oven of 150 ° C, heated for 30 days, taken out of the test piece, and the degree of yellowness was measured with a colorimeter.

Example 1 Polystyrene resin (manufactured by Mitsubishi Monsanto Co., Ltd .; HF77)
(General grade) 40% by weight and decabromodiphenyl ether (manufactured by Toso Corporation, frame cut 110R) 6
0% by weight, 2,6-di-t-butyl-p-cresol (manufactured by Yoshitomi Pharmaceutical Co., Ltd .; Yoshinox BHT) 0.1% by weight, calcium stearate 0.1% by weight were mixed with a Hensel mixer, Extrusion was performed at a resin temperature of 250 ° C. with a twin-screw kneading extruder having a diameter of 30 mmφ to produce pellets. Then, the pellets are 10% by weight, antimony trioxide 2% by weight
t% and polypropylene resin (manufactured by Tosoh Corporation; J70)
90 impact-resistant grade) 88% by weight was mixed and pellets were prepared at 210 ° C. using the same twin-screw extruder. Further, the pellets were heated to a resin temperature of 23 using an injection molding machine of 150 tons.
A test piece was prepared at 0 ° C. The results are shown in Table 1. Bull-
It has very good lumping and thermal stability.

Example 2 After preparing a PP flame-retardant compound by mixing 30 wt% of the masterbatch prepared in Example 1, 9 wt% of antimony trioxide and 61 wt% of polypropylene resin, test pieces were prepared in the same manner as in Example 1. It was created. The results are shown in Table 1.
Very good blooming and thermal stability.

Example 3 In the same manner as in Example 1, a masterbatch was prepared by mixing 20% by weight of polystyrene resin (manufactured by Mitsubishi Monsanto Co., Ltd .; HT88 impact grade) and 80% by weight of decabromodiphenyl ether. , This masterbatch 20
A test piece was prepared with a weight of 8% by weight of antimony trioxide and 72% by weight of polypropylene resin. The results are shown in Table 1. Very good blooming and thermal stability.

Comparative Example 1 Example 1 was used instead of the pre-made masterbatch.
A flame-retardant PP compound was prepared using the same amount of decabromodiphenyl ether as used in 1. to prepare a test piece.
The results are shown in Table 1. Inferior blooming resistance.

Comparative Example 2 A test piece was prepared in the same manner as in Example 2 except that a polycarbonate resin (I-1250 manufactured by Teijin Chemicals Ltd.) was used as the base resin of the masterbatch. The results are shown in Table 1. Inferior blooming resistance.

Comparative Example 3 A test piece was prepared in the same manner as in Example 2 except that polybutylene terephthalate resin (C7000N manufactured by Teijin Ltd.) was used as the base resin of the masterbatch. The results are shown in Table 1. Inferior blooming resistance.

[0027]

As is apparent from the above description, the composition of the present invention is extremely defective in blooming resistance and thermal stability, which are disadvantages in making a polyolefin resin flame-retardant with an organic halogen-based flame retardant. It is a good composition.

[Table 1]

Claims (1)

[Claims] 1. Polystyrene resin 10-90w in advance
t% and decabromodiphenyl ether 90 to 10 wt
% Composition kneaded at 210 to 290 ° C. 2-3
A method for producing a flame-retardant resin composition, which comprises blending 0 wt% with 60 to 97 wt% polyolefin resin and 0.5 to 20 wt% antimony trioxide.