JPH04149263A - Flame-retardant resin composition - Google Patents

Abstract

PURPOSE:To obtain a resin composition suitable for providing large sized molded articles such as external parts of television receiver, having excellent impact strength, flame retardance and fluidity by blending a specific rubber modified vinyl aromatic resin with specific amounts of polyphenylene ether, red phosphorus, etc. CONSTITUTION:100 pts.wt. total amounts of (A) 97-75 pts.wt. rubber modified vinyl aromatic resin prepared by dispersing a particulate rubber-like polymer having 0.6-4 micron average particle diameter into a matrix composed of a vinyl aromatic polymer and (B) 3-25 pts.wt. polyphenylene ether are blended with (C) 1-15 pts.wt., preferably 3-8 pts.wt. red phosphorus and (D) 0-10 pts.wt., preferably 3-6 pts.wt. mineral oil.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a resin composition with excellent flame retardancy.

More specifically, the present invention relates to a flame-retardant styrenic resin composition that does not contain a halogen compound.

[Problems to be solved by conventional technology and invention] 1 (IP
Rubber-modified vinyl aromatic resin represented by S has moldability,
In addition to its excellent dimensional stability, it has excellent impact resistance, rigidity, and electrical insulation properties, so it has come to be used in a wide variety of fields, including home appliance parts and OA equipment parts.

Regarding plastic materials used in such fields in recent years,
Due to safety issues, the demand for flame retardant properties is increasing.
Various flame retardant standards have been established. Various methods have been devised to impart flame retardancy to such easily combustible resins, but the most common ones include halogen compounds such as bromine compounds, which have a high flame retardant effect, and oxidation as necessary. A method has been adopted in which antimony is added to the resin. As bromine compounds, nuclear bromine-substituted aromatic compounds such as decabromodiphenyl ether, tetrabromo biorphenol A, and brominated phthalimide are known, but the method of adding these flame retardants provides excellent flame retardancy. Of course,
There have been problems such as a decrease in impact strength and heat distortion temperature, and in some cases, flame retardant may bleed out onto the surface of the resin molded product, deteriorating the appearance of the molded product. Furthermore, during molding of the resin, thermal decomposition of the halogen compound generates gas toxic to the human body and corrodes the mold and screw.

For this reason, methods of making flame retardant without using halogen compounds are being considered. As such a method, a method of adding hydrated metal compounds such as aluminum hydroxide and magnesium hydroxide to the resin is known, but in order to obtain sufficient flame retardancy, it is necessary to add a large amount of the hydrated metal compounds. This has the disadvantage that the original properties of the resin are lost.

On the other hand, as a method that does not use such hydrated metal compounds,
Blending thermoplastic resin with phenol/aldehyde resin, organic nitrogen compound, and organic phosphorus compound.

Flame retardant resin composition (U.S. Pat. No. 4.632.94)
No. 6 specification), a flame-retardant resin composition made by blending ABS resin with red phosphorus, melamine, and a thermally crosslinked curable resin (Japanese Patent Application Laid-open No. 61-2!06431 discloses. However, such a method There is a problem in that a large amount of various additives are required and the original properties of the resin are impaired.

On the other hand, U.S. Pat. No. 4,461,874 discloses a flame-retardant resin composition comprising Bojenyden, a styrene resin, and red phosphorus.

Although the above resin composition is a useful flame-retardant resin material that does not use halogen compounds, it still has problems such as poor flowability and moldability because it contains a large amount of polyphenylene ether, which has low fluidity. .

[Means for Solving the Problems] The present inventors have conducted intensive studies to solve the above-mentioned problems of resin compositions made of rubber-modified vinyl aromatic resin, polyphenylene ether, and red phosphorus, and have identified! The present inventors have discovered that a resin composition consisting of a rubber-modified vinyl aromatic resin of F+ structure, a small amount of polyphenylene ether, phosphorus, and, if necessary, mineral oil can efficiently solve the above problems, and have completed the present invention. 6 In other words, the present invention comprises lλ) 97 to 75 parts by weight of rubber-modified vinyl aromatic resin, B
) polyphenylene ether 3 to 25 parts by weight total
C) 1 to 15 parts by weight of red phosphorus D) 0 to 10 parts by weight of mineral oil per 100 parts by weight, the resin composition comprising:
The present invention provides a flame-retardant resin composition characterized in that the vinyl aromatic resin has dispersed rubber particles having a weight average particle diameter in the range of 06 to 4.0 microns.

The resin composition of the present invention includes a resin component consisting of a rubber-modified vinyl aromatic resin referred to as component A, a polyphenylene ether referred to as component B, red phosphorus as a flame retardant imparting component, and optionally added. It consists of mineral oil, which is a fluidity imparting component, and B accounts for the above resin component.
The proportions of the components range from 3 to 25% by weight. If the proportion of component B is less than 3% by weight, the tI flammability is insufficient, and if it exceeds 25% by weight (well, the molding processability is extremely poor, and it does not fall within the scope of the present invention. A more preferable range of component B is 5 to 15% by weight.

The rubber-modified vinyl aromatic resin of component A above refers to a polymer in which a rubber-like polymer is dispersed in the form of particles in a matrix made of a vinyl aromatic polymer. It can be obtained by dissolving the monomer in the group monomer (and a liquid containing an inert solvent) and performing bulk polymerization, bulk suspension polymerization, or solution polymerization under stirring to precipitate and form a bueno-like polymer into particles. It will be done.

In addition to tyrene, the above-mentioned vinyl aromatic compounds include
0-methylstyrene, p-methylstyrene, m-methylstyrene, 2.4 dimethylstyrene, ethylstyrene,
Examples include nuclear alkyl-substituted styrenes such as p-tert-butylstyrene, a-alkyl-substituted styrenes such as α-methylstyrene, α-methyl-p-methylstyrene, etc. 1 Representative 5::;Styrene It is. Two or more of these may be used in combination.

Examples of the rubbery polymer include polybutadiene, styrene-butanene copolymer, polyisoprene, butadiene-isoprene copolymer, natural rubber, ethylene-propylene copolymer, etc. ,
Polybutadiene and styrene-butadiene copolymers are preferred.

The rubber-modified vinyl aromatic resin as the component A of the present invention has a weight average particle diameter f' of dispersed rubber particles of 0.6 to 4.0.
It needs to be in the micron range.

If the weight average particle diameter of the dispersed rubber particles is less than 0.6 microns or exceeds 4.0 microns, the final resin composition will have poor impact strength. A more preferable range of weight average particle diameter is 0.8 to 3.
It is 0 micron.

The weight average particle diameter of the dispersed rubber particles is determined by taking a transmission electron micrograph of the modified vinyl aromatic resin using an ultra-thin section method, and then determining the diameter of 1,000 rubber particles. , calculated according to the following formula.

Σn+Di” Rubber particle diameter = ΣniD Song D, diameter of dispersed rubber particles.

Number of rubber particles with a diameter of n6.

When preparing a rubber-modified vinyl aromatic resin, the general means to satisfy the above requirements regarding dispersed particles is to use rubber particles in bulk polymerization, bulk suspension polymerization, or solution polymerization. Examples of this include controlling the number of stirrings or shearing rate during precipitation.

Next, the content of the rubber-like polymer in component A can be adjusted as appropriate, but is strategically in the range of 5 to 15% by weight. In addition, the higher the content of the rubbery polymer, the more difficult it is to melt and drop during combustion. ``more preferable''.

In addition, the content of gel in the toluene solvent (toluene insoluble matter) in component A can be adjusted as appropriate within the range of 20-40% by the enrichment method. It is more preferable to control the flow strength and flame retardancy in the range of 625 to 40%. 6 Also, the swelling index of the gel component due to the L-luene solvent in the finally obtained resin composition is , 4 to 14 i self-surrounding 4: is preferable, <,
More preferably, it is in the range of 8 to 12. When the swelling index does not reach 4, the impact strength of the resin composition tends to be poor, and when it exceeds I4, the resin composition tends to have poor gloss. The above-mentioned swelling finger V contains a resin composition,
In order to efficiently achieve the above requirements regarding the gel component, which is determined as the weight ratio before and after toluene drying of the gel component obtained by dissolving it in toluene and centrifuging it,
This can be achieved efficiently by controlling the swelling index of the gel component in the rubber-modified vinyl aromatic resin due to the toluene solvent to a range of 8 to 18 before melt-mixing with the polyphenylene ether.

In addition, there are particular restrictions on the reduced viscosity of the matrix part of component A (value measured with a CA-7I infence type viscometer using a 0.5% toluene solution of the matrix part from which toluene insoluble matter has been removed from the rubber-modified vinyl aromatic resin). There is no, but
Preferably the range is 0.4-1.2 dl/g 0-50
The range of 1,80 dl/g is more preferable.

Next, polyphenylene referred to as component B of the present invention (herein, R, , R, , R, , R, is each selected from the group consisting of hydrogen, hydrocarbon, or substituted hydrocarbon group) , which may be the same or different, and have a reduced viscosity (0.5 g/dl, chloroform solution, measured at 30°C) in the range of 0.15 to 070 dl/'g, more preferably 0.5 g/dl, measured at 30°C. 20 to 0.60d17"g. Specific examples of this PPE include poly(2,6-dimethyl-1,4-phenylene needle), A copolymer of 2,6-dimethylphenol and 2,3,6-1-limethylphenol is preferred, and among these, bot (2,6-dimethyl-1,4-phenylene/n-edel) is preferred. preferable.

These four methods of making PPEO are those obtained by known methods and are not particularly limited or are limited in any way, for example, US Pat. No. 3,306. It can be easily produced by oxidative polymerization of, for example, 2,6-kydylenol using Daiichi@Hanawa and amine Humbrex as a catalyst according to the method described in U.S. Pat. :30
6.875 specification, U.S. Patent No. 3.257, 357 specification, U.S. Patent No. 3.257.358 specification and Japanese Patent Publication No. 52-L7880, JP-A-50-5119
It can be easily manufactured by the method described in Publication No. 7.

Next, in the present invention, red phosphorus is used as the third component. The red phosphorus may be in the form of fine particles, but from the viewpoint of handling, it is preferable to use one whose surface is coated with resin, mineral oil, or metal hydrate.

The content of the red phosphorus needs to be 1 to 15 parts by weight based on 100 parts by weight of the resin component consisting of the A component and the B component. If the amount is less than 1 part by weight, sufficient flammability cannot be obtained;
If the amount exceeds 1 part by weight, the impact strength, moldability, and appearance of the final composition will be poor. A more preferred amount is 2 to 10 parts by weight, and an even more preferred amount is 3 to 8 parts by weight.

In the present invention, the above A), B1. Add D) mineral oil to C) ingredients as necessary, and add A1. The IO heavy lid part can be added up to the upper limit of the total of 100 parts by weight of both Bl components. If the amount of mineral oil added exceeds 10 parts by weight, the heat distortion temperature of the final resin composition will decrease, and oily substances will accumulate on the mold surface during molding, which is undesirable. A more preferable amount of oil added is 3 to 6 parts by weight. As mineral oil, you can use commonly used mineral oil, but lOn+
It is more preferable that the initial boiling point in mHg is above 210° C. As a mineral oil that satisfies such conditions, for example, Crystoll 352, which is a mineral oil manufactured by Esso Oil, can be mentioned.

In addition, when polymerizing the rubber-modified vinyl aromatic resin as the component B, the entire amount or a part of the mineral oil is added to the polymerization solution to adjust the mineral oil-containing rubber-modified vinyl aromatic resin. The content of mineral oil in the resin composition obtained can also be adjusted.6 There are no particular restrictions on the method of blending each component of the above A-C (or A-C and D), and an extruder, a kneader The above components may be melt-mixed using a commonly used mixer such as a Banbury mixer. At this time, if possible, prior to mixing component C,
The A component and the B component are kneaded in advance, and then the C component is added and kneaded. It is preferable that the B component is evenly distributed.

The present invention will be explained in detail with reference to Examples below.

[Example] In the following Examples and Comparative Examples, the following samples were used.

[Example: Preparation of rubber-modified vinyl aromatic resin] [Reference Example 1 Rubber-modified vinyl aromatic resin, SL] A polymerization stock solution having the following composition was prepared.

Butadiene rubber: 8.0 parts by weight (NF-35A manufactured by Asahi Kasei Industries, Ltd.) - Styrene: 77.0 parts by weight Ethylbenzene 15.0 parts by weight - α-Methyl, Rustyrene die? -: 0.063
0.10 parts by weight of stearyl 3-i3.5-phtaht-butyl-4-hydroquinophenyl)-propio-T-t.Then, the above polymerization stock solution was continuously fed to a multi-stage reactor equipped with a stirring bar, Polymerization was performed. The polymerization temperature and stirring time were adjusted so that the weight average particle diameter of the rubber particles was 2.3 μm and the solid content concentration of the final reaction scrape was 80% by weight. Subsequently, the polymerization liquid was led to a devolatilization device, and the rubber content was reduced to 10
% by weight of rubber-modified vinyl aromatic resin was obtained. As a result of analyzing the obtained rubber-modified vinyl aromatic resin, the gel content was found to be 3.
2% by weight, the swelling index of the gel component is 12.5. The reduced viscosity of the matrix portion was 0.75 dl/g.

[Reference Example 2゛Rubber-modified vinyl aromatic resin, S2] Same as Philosophical Example I except that the stirring number was increased, the average particle size of the rubber particles was 0.5 mm, and the rubber content was 10. A rubber-modified vinyl aromatic resin with a heavy weight of % was obtained. As a result of analyzing the obtained rubber-modified vinyl aromatic resin, the gel content was found to be 26.
% by weight, the swelling index of the gel component was 10.9, and the reduced viscosity of the matrix portion was 0.76 dl, 1 g.

[Reference Example 3 - Rubber-modified vinyl aromatic resin, S3] A rubber with a weight average particle diameter of 5.8 microns and a rubber content of 1110% by weight was produced in the same manner as in Reference Example 1 except that the stirring number was reduced. A modified vinyl aromatic resin was obtained. As a result of analyzing the obtained rubber-modified vinyl aromatic resin, the gel content was found to be 32.
The swelling index of the gel component was 10.2 by weight, and the reduced viscosity of the matrix portion was 0.74d17g.

[Reference Example 4: Adjustment of PPE] After sufficiently purging the inside of a stainless steel reaction column with an oxygen inlet at the bottom of the reactor, a cooling coil, and a stirring blade inside with nitrogen, cupric bromide 54 -8g, G-n
-butylamine 1110g, and toluene 20ff,
2 in a mixed solvent of n-butanol at 16℃ and 4 in methanol.
．． 8.75 kg of 6-xylenol was dissolved and charged into the reactor. M element was continuously blown into the reactor while stirring, and polymerization was carried out for 180 minutes while controlling the internal temperature at 30°C. After the polymerization was completed, a methanol/hydrochloric acid mixture was added to the precipitated polymer to decompose the remaining catalyst in the polymer, and the polymer was thoroughly washed with methanol and dried.
Powdered PPE was obtained. The reduced viscosity was 0.55 dl/g.

[Examples 1 to 5, Comparative Examples] to 7] Rubber-modified vinyl aromatic resin PPE prepared in Reference Example, red phosphorus (manufactured by Rin Kagaku Kogyo ■, Norbalet #120, red phosphorus content 85% by weight) and mineral Oil (mineral oil manufactured by Esso Oil ■, Cristol 352, 10m
m)1. g (initial boiling point 237°C) were blended in the proportions shown in Table 1 and kneaded in a twin-screw extruder to obtain pellets of the resin composition.Next, test pieces were created in an injection molding machine. ,
Mechanical properties and flammability tests were conducted. The physical properties and flammability tests were conducted according to the following methods.

・Izotsu impact strength: ASTM D-256+/with holes) ・Melt flow rate: 15O-R1133
(200℃, 5kg load) Vicat Softening Point: ASTM D-1525
Flammability: UL-94 (
Table 1 shows the results for 1/12 months.

(Margins below C) [Example 6] Using the resin composition of Example 2, the cylinder temperature was 25 in an injection molding machine (Toshiba Shibuta Equipment 5800B-75).
Under the conditions of 0° C. and mold temperature of 45° C., a molded body of a TV receiver (4#, machine outer shell part) with an average wall thickness of 3 mm was obtained [Comparative Example 81 In Example 6, the resin assembly of Example 2, By changing to acid,
The same operation as in Example C3 was performed except that the resin composition of Comparative Example 3 was used, but the fluidity of the resin was poor and a molded article could not be obtained.

[Performance (171) Using the resin composition of Example 5, the cylinder temperature was set to 240
The same operation as in Example 6 was performed except that the temperature was changed to .degree. C., and a good molded product was obtained.

(The following is a blank space) [Effects of the Invention] As is clear from Table 1, the resin composition of the present invention has excellent impact strength, flame retardance, and fluidity, and is useful as a resin material for injection molding. . Furthermore, the resin composition of the present invention has excellent fluidity and is suitable for obtaining large molded products such as outer shell parts of TV receivers.

Patent 17 applicant: Asahi Kasei Industries, Ltd.

Claims (1)

[Claims] 1) A) 97 to 75 parts by weight of a rubber-modified vinyl aromatic resin, B) 3 to 25 parts by weight of polyphenylene ether, a total of 10 parts by weight.
0 parts by weight of C) 1 to 15 parts by weight of red phosphorus D) 0 to 10 parts by weight of mineral oil, wherein the rubber-modified vinyl aromatic resin has a weight of the dispersed rubber particles. A flame-retardant resin composition having an average particle diameter in the range of 0.6 to 4.0 microns.