JPH04370134A - Halogen-free flame-retarding resin composition - Google Patents

Abstract

PURPOSE:To obtain a halogen-free flame-retarding resin composition having excellent impact strength, heat-resistance and flame-retardance by compounding a halogen-free organic phosphorus compound and a nitrogen-containing compound to a rubber-modified vinylaromatic resin and a polyphenylene ether. CONSTITUTION:The objective flame-retarding resin composition is composed of (A) a rubber-modified vinylaromatic resin consisting of a vinylaromatic polymer matrix and a rubbery polymer (preferably polybutadiene or styrene- butadiene copolymer) dispersed in the matrix in the form of particles, (B) a polyphenylene ether [preferably poly(2,6-dimethyl-1,4-phenylene ether)], (C) 5-25 pts.wt., preferably 10-20 pts.wt. (based on 100 pts.wt. of A+B) of a halogen-free organic phosphorus compound having a melting point of >=180 deg.C and containing the atomic group of formula (R1 to R3 are H, 1-8C alkyl, aralkyl, cyclohexyl, phenyl, etc.) and (D) 5-25 pts.wt., preferably 10-20 pts.wt. of triazine and/or its derivative (preferably melamine). The amount of the component B is >=10 pts.wt. and <20 pts.wt. in 100 pts.wt. of A+B.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition having excellent flame retardancy. More specifically, the present invention relates to a flame-retardant styrenic resin composition that does not contain a halogen compound.

0002

[Prior art and problems to be solved by the invention] HIPS
Rubber-modified vinyl aromatic resins, represented by , have excellent moldability and dimensional stability, as well as impact resistance, rigidity, and electrical insulation properties, so they are used in home appliance parts, OA equipment parts, and other applications. It has come to be used in a wide variety of fields. In recent years, there has been an increasing demand for flame retardancy for plastic materials used in such fields due to safety concerns, and various flame retardant standards have been established. Various methods have been devised to impart flame retardancy to such easily flammable resins, but in general, halogen compounds such as bromine compounds, which have a high flame retardant effect, and antimony oxide, if necessary, are used. A method is adopted in which the compound is added to the resin.

However, although these methods of adding halogen compounds provide excellent flame retardancy, impact strength and heat distortion temperature decrease, and in some cases, the flame retardant may bleed out onto the surface of the resin molded product. This has led to problems such as deterioration of 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.

[0004] For this reason, methods of making flame retardant without using halogen compounds are being studied. As such a method, a method of adding a hydrated metal compound such as aluminum hydroxide or 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 compound. 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 a hydrated metal compound, a flame-retardant resin composition comprising a vinyl aromatic resin, polyphenylene ether, an organic phosphorus compound, and a triazine (JP-A-54-38348; Showa 54-3
Publication No. 8349, Specification of European Patent No. 311,909)
is disclosed. Further, JP-A-53-5253 discloses a flame-retardant resin composition comprising a vinyl aromatic resin, polyphenylene ether, a reaction product of an organic phosphorus compound and triazine.

However, the above-mentioned Japanese Patent Application Laid-Open No. 54-3834
No. 8, JP-A-54-38349, European Patent No. 311,909, and JP-A-53-5253 all have useful flame retardant properties that do not use halogen compounds. Although it is a resin material, the heat distortion temperature of the resin composition is low, and in order to make it a practical molding material, there is a problem that it is necessary to use a large amount of expensive polyphenylene ether.

[0007]

[Means for Solving the Problems] As a result of intensive studies to solve the above problems, the present inventors have developed an organic phosphorus compound with a specific structure in a resin component consisting of a rubber-modified vinyl aromatic resin and a small amount of polyphenylene ether. , and a nitrogen-containing compound, it has been discovered that the above problems can be efficiently solved, and the present invention has been completed.

That is, the present invention comprises (A) a rubber-modified vinyl aromatic resin in which a rubbery polymer is dispersed in the form of particles in a vinyl aromatic polymer matrix, and (B) polyphenylene ether; , (B) Total of both components 1
100 parts by weight of a resin component in which component (B) is 10 parts by weight or more and less than 20 parts by weight, (C) a non-halogen organic compound having a melting point of 180° C. or higher and having an atomic group represented by the following formula 2. 5 to 25 parts by weight of a phosphorus compound,

[0009]

[Case 2]

(D) A non-halogen flame-retardant resin composition comprising 5 to 25 parts by weight of a nitrogen-containing compound comprising triazine and/or a derivative thereof. Hereinafter, the contents of the present invention will be explained in order. The resin composition of the present invention comprises a resin component consisting of a rubber-modified vinyl aromatic resin as the component (A) and a polyphenylene ether as the component (B), and the component (C) as a flame retardant component. It consists of the non-halogen organic phosphorus compound mentioned above and the nitrogen-containing compound mentioned above as component (D).

In the resin composition of the present invention, the proportion of component (B) in 100 parts by weight of the resin component is 10
The range is from 20 parts by weight to 20 parts by weight. If the proportion of component (B) is less than 10 parts by weight, the flame retardance will not be sufficient, and if it is more than 20 parts by weight, the molding processability will be extremely poor and do not fall within the scope of the present invention. The polyphenylene ether (hereinafter abbreviated as PPE) referred to as component (B) above is a homopolymer and/or copolymer consisting of bonding units represented by the following formula 3.

0012

[Chemical formula 3]

[0013] A specific example of this PPE is poly(
2,6-dimethyl-1,4-phenylene ether), 2
, 6-dimethylphenol and 2,3,6-trimethylphenol are preferred, and among them, poly(2
, 6-dimethyl-1,4-phenylene ether) is preferred. The method for producing such PPE is not particularly limited as long as it can be obtained by a known method. For example, a complex of a cuprous salt and an amine may be produced by the method described in U.S. Pat. No. 3,306,874. used as a catalyst,
For example, it can be easily produced by oxidative polymerization of 2,6 xylenol.
No. 875, U.S. Patent No. 3,257,357, U.S. Patent No. 3,257,358, and Japanese Patent Publication No. 52-17880 and Japanese Patent Application Laid-open No. 50-51197. It can be easily manufactured by this method. The reduced viscosity (0.5 g/dl, chloroform solution, measured at 30°C) of the PPE used in the present invention is 0.20 to 0.70 d.
It is preferably in the range of l/g, 0.30 to 0.6
More preferably, it is in the range of 0 dl/g. As a means for satisfying the above-mentioned requirements regarding the reduced viscosity of PPE, there may be mentioned adjustment of the amount of catalyst during the production of the PPE.

Next, the rubber-modified vinyl aromatic resin of component (A) is a rubber-like polymer dispersed in the form of particles in a vinyl aromatic polymer matrix composed of vinyl aromatic monomers. This is a rubber-modified vinyl aromatic resin. In addition to styrene, the above-mentioned vinyl aromatic monomers include o-
Methylstyrene, p-methylstyrene, m-methylstyrene, 2,4 dimethylstyrene, ethylstyrene, p-
Nuclear alkyl-substituted styrenes such as tertiary-butylstyrene, α-alkyl-substituted styrenes such as α-methylstyrene, α-methyl-p-methylstyrene, etc. can be mentioned, and the representative one is styrene. Two or more of these may be used in combination.

The reduced viscosity of the vinyl aromatic polymer matrix portion (0.5 g/dl, toluene solution) is controlled within the conventional range of 0.40 to 1.20 dl/g, preferably 0.50 to 1.20 dl/g. It is in the range of 1.00 dl/g. Next, as a method for producing the rubber-modified vinyl aromatic resin, the rubber-like polymer described later is generally mixed with a vinyl monomer mainly composed of the vinyl aromatic monomer (and an inert solvent added thereto). The above vinyl monomers can be obtained by dissolving the rubber-like polymer in a latex solution and performing bulk polymerization, bulk suspension polymerization, or solution polymerization with stirring to precipitate and granulate the rubber-like polymer, or add the above-mentioned vinyl monomers to the latex of the rubber-like polymer. It can be obtained by adding a vinyl aromatic polymer prepared separately as necessary to a rubber-like polymer-containing vinyl aromatic polymer obtained by emulsion polymerization.

[0016] Examples of the rubbery polymer include polybutadiene, styrene-butadiene copolymer, polyisoprene,
Examples include butadiene/isoprene copolymer, natural rubber, ethylene/propylene copolymer, etc., but polybutadiene and styrene/butadiene copolymer are generally preferred. There are no particular restrictions on the rubbery polymer content in the rubber-modified vinyl aromatic resin, but generally it is 4.
-15% by weight, more preferably 6-12% by weight.

Next, in the resin composition of the present invention, (C) a non-halogen organic phosphorus compound represented by the above formula (1) and having a melting point of 180° C. or higher is combined with the above (A) and (B) as the third component. It is necessary to contain 5 to 25 parts by weight based on the total of 100 parts by weight of the components. The non-halogen organic phosphorus compound of component (C) has a melting point of 18
If the temperature is not higher than 0°C, the heat deformation temperature of the resin composition finally obtained will be low.

A specific example of a non-halogen organic phosphorus compound satisfying the above requirements is 10-(3,5-di-tert-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10- phosphaphenanthrene,
10-(2,5-dihydroxyphenyl)-10H-9
Examples include -oxa-10-phosphaphenanthrene=10-oxide.

If the content of the non-halogen organic phosphorus compound is less than 5 parts by weight, the flame retardancy of the resin composition finally obtained will not be sufficient, and if the content exceeds 25 parts by weight, This is not preferable because the heat distortion temperature of the resin composition finally obtained is lowered. A more preferable content of the non-halogen organic phosphorus compound is 10 to 20 parts by weight.

Next, in the resin composition of the present invention, (D) a nitrogen-containing compound selected from triazine and/or its derivatives is added as the fourth component to a total of 1 of the components (A) and (B).
It is necessary to contain 5 to 25 parts by weight per 00 parts by weight. If the content is less than 5 parts by weight, the flame retardance of the final resin composition will not be sufficient,
Moreover, if the content exceeds 25 parts by weight, the impact strength of the resin composition finally obtained will decrease, which is not preferable. A more preferable content of the nitrogen-containing compound is 10 to 20 parts by weight. Specific examples of the nitrogen-containing compound suitable for the resin composition of the present invention include melamine, succinoguanamine, adipoguanamine, methylglutaguanamine, and the like, with melamine being the most preferred.

[0021] When blending each of the above components (A) to (D), a commonly used mixer such as an extruder, kneader, or Banbury mixer may be used. ) and (C) to increase the dispersion of the components,
Components (B) and (C) and a portion of component (A) are melt-kneaded in advance under high temperature conditions, and then the remaining (A)
By adding the components and melt-mixing them again, more uniform mixing of each component can be achieved.

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

[0023]

[Example] In the following examples and comparative examples, the following samples were used.

[0024]

[Reference Example 1 - Preparation of rubber-modified vinyl aromatic resin (A1)] A rubber-modified vinyl aromatic resin was prepared by the following method. A polymerization stock solution having the following composition was prepared.・Polybutadiene rubber
:10.0 parts by weight ・Styrene
:75.0 parts by weight ・Ethylbenzene
: 15.0 parts by weight ・α-methylstyrene dimer : 0.06 parts by weight
・Stearyl 3-(3,5-ditertiarybutyl-4-
Hydroxyphenyl)-propionate
: 0.15 parts by weight The above polymerization stock solution was then continuously fed into a multi-stage reactor equipped with a stirring bar to carry out polymerization. The polymerization temperature and the number of stirring were adjusted so that the average particle diameter of the rubber particles was 2.5 microns and the solid content concentration at the end of the reactor was 80% by weight. Subsequently, the polymerization liquid was led to a devolatilization device, and the rubber content was 12.5% by weight.
A rubber-modified vinyl aromatic resin was obtained. As a result of analyzing the obtained rubber-modified vinyl aromatic resin, the reduced viscosity of the matrix was 0.72 dl/g.

[0025]

[Reference Example 2 - Preparation of PPE (B1)] After sufficiently replacing the interior of a stainless steel reactor with an oxygen inlet at the bottom of the reactor, a cooling coil, and a stirring blade inside, the bromide 2 copper 54.8 g, di-n-butylamine 11
10 g, and 20 liters of toluene, 1 n-butanol
2,6 in a mixed solvent of 6 liters and 4 liters of methanol.
- 8.75 kg of xylenol was dissolved and charged into the reactor. Oxygen 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, the precipitated polymer was filtered out, a methanol/hydrochloric acid mixture was added to decompose the remaining catalyst in the polymer, and the polymer was thoroughly washed with methanol and dried to obtain powdered PPE. The reduced viscosity was 0.55 dl/g.

[0026]

[Reference Example 3 - Organic phosphorus compound] C1:10-(3,5-
di-tert-butyl-4-hydroxybenzyl)-
9,10-dihydro-9-oxa-10-phosphaphenanthrene [melting point 203°C] C2:10-(2,5-dihydroxyphenyl)-10
H-9-oxa-10-phosphaphenanthrene = 10
-oxide [melting point 253°C] C3: 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide [melting point 115°C]
C4: Triphenylphosphine oxide [melting point 156
°C] C5: Triphenyl phosphite [melting point 48 °C]

00
27]

[Reference Example 4-Nitrogen-containing compound] D1: Melamine

0028
]

[Examples 1 to 3, Comparative Examples 1 to 7] Rubber modified vinyl aromatic resin prepared in Reference Example, PPE, organic phosphorus compound,
Nitrogen-containing compounds were blended in the proportions shown in Table 1 and kneaded using a twin-screw extruder to obtain pellets of the resin composition. Next, test pieces were prepared using an injection molding machine, and mechanical properties and flammability tests were conducted. The physical properties and flammability tests were conducted according to the following methods.

・Izod impact strength: ASTM D2
56 (notched) ・Melt flow rate: ISO-R1133 (200℃
, 5 kg load) Vicat Softening Point: ASTM D-1525 Flammability: UL-94 (1/12 inch) The results are shown in Table 1.

[0030]

[Table 1]

[0031]

EFFECTS OF THE INVENTION As is clear from Table 1, the resin composition of the present invention has excellent impact strength, heat resistance, and flame retardancy, and is useful as a material for injection molding.

Claims (1)

[Claims] Claim 1: Comprising (A) a rubber-modified vinyl aromatic resin in which a rubbery polymer is dispersed in the form of particles in a vinyl aromatic polymer matrix, and (B) polyphenylene ether; ) 100 parts by weight of a resin component in which component (B) accounts for 10 parts by weight or more and less than 20 parts by weight in a total of 100 parts by weight of both components; (C) a resin component having an atomic group represented by the following formula 1 and having a melting point of 180 A flame-retardant resin composition comprising 5 to 25 parts by weight of a non-halogen organic phosphorus compound having a temperature of 5 to 25 parts by weight, and (D) 5 to 25 parts by weight of a nitrogen-containing compound made of triazine and/or a derivative thereof.