JPH0987511A - Polyphenylene ether-based flame-retardant resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyphenylene ether-based flame-retardant resin compsn. which has excellent stability by comprising either a polyphenylene ether resin or a compsn. comprising a polyphenylene ether resin and a polystyrene resin; and an organophosphorus compd. represented by a particular formula. SOLUTION: Ten(10) to 99 pts.wt.(hereinafter referred to as 'pts.') polyphenylene ether resin, such as poly(2,6-dimethyl-1,4-phenylene) ether and 90 to 1 pt. polystyrene resin, such as a rubber-modified polystyrene, are mixed together to prepare a resin compsn. At least one organophosphorus compd. represented by formula I (where X represents a group represented by formula II; (j), (k), (l), and (m) are 0 or 1; R1 to R4 represent phenyl, xylyl, or cresyl; and (n) is a natural no.), such as an organophosphoric ester, in an amt. of 0.1 to 100 pts. and a predetermined amt. of a plasticizer, a flame retardant, etc., are added and mixed with 100 pts. polyphenylene ether resin or polyphenylene ether resin compsn. The mixture is melt-kneaded by means of a twin-screw extruder or the like and then extruded and pelletized, thereby preparing a polyphenylene ether-based flame-retardant resin compsn.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polyphenylene ether flame-retardant resin composition comprising a polyphenylene ether resin and a specific organic phosphorus compound, which is excellent in stability, heat resistance and molding processability.

[0002]

2. Description of the Related Art Polyphenylene ether resins are excellent in mechanical properties, electrical properties, acid resistance, alkali resistance, heat resistance, etc., and have low water absorption and good dimensional stability. It is widely used as a material for housings and chassis of office automation equipment such as computers and word processors, but these materials are often required to have high flame retardancy.

Although polyphenylene ether resin has excellent flame retardancy, it is generally used as an alloy with a styrene resin because it is inferior in processability, and the flame retardancy is impaired. . It has been conventionally known that a polyphenylene ether resin can be improved in flame retardancy by compounding a phosphoric acid ester compound such as triphenyl phosphate, cresyl diphenyl phosphate, tricresyl phosphate, and isopropylphenyl phosphate as a flame retardant. . However, also those containing the above flame retardant, heat resistance of the resin composition, deterioration of physical properties, volatilization of the phosphoric acid ester compound during molding, smoke generation,
Further improvements are required for bleeding and the like.

In order to solve the above problems, attempts have been made to put an organophosphate compound having a large molecular weight into practical use as a flame retardant. For example, European Patent Application Publication No. 7
No. 460, tri (2,6-dimethylphenyl) phosphate compound, European Patent Application Publication No. 129824.
No. 129,825, European Patent Application Publication No. 129825, European Patent Application Publication No. 135726, and British Patent Application Publication No. 2043083.
Bisdiphenyl phosphate compounds, US Pat. No. 46
No. 83255 discloses tribiphenyl phosphate compounds.

However, these phosphoric acid ester compounds must be used in large amounts for flame retardancy. According to our research and analysis, resin compositions flame-retarded by using these phosphoric acid ester compounds corrode the mold during molding, and during molding processing and molded products are used for a long time. During that time, the flame retardant may be denatured, the molded product may be discolored or blistered, or water absorption may deteriorate the electrical properties and flame retardant properties of the molded product. As described above, the conventional techniques have not been able to provide a resin composition that simultaneously satisfies sufficient flame retardancy, performance required as a product, and stability. Above all, further improvement is demanded for the balance between heat resistance and molding processability of the resin composition.

[0006]

DISCLOSURE OF THE INVENTION The present invention has excellent stability that does not cause volatilization, smoke emission and bleeding of a flame retardant at the time of molding, and can withstand long-term use or recycling use.
Moreover, it is an object of the present invention to provide a polyphenylene ether flame-retardant resin composition having an excellent balance between heat resistance and molding processability.

[0007]

Means for Solving the Problems The present inventors have completed the present invention as a result of extensive studies to achieve the above-mentioned object. That is, the present invention provides 100 parts by weight of (A) polyphenylene ether resin, or 10 to 99 parts by weight of polyphenylene ether resin and 90 to 1 of polystyrene resin.
100 parts by weight of the composition, and (B) the following formula (I)
1 or 2 or more types of organic phosphorus compounds represented by 0.1
It is a polyphenylene ether-based flame-retardant resin composition, characterized in that

[0008]

Embedded image

(However, X in the above formula is a group represented by the following formula,

[0010]

Embedded image

N is a natural number, and j, k, l and m are each independently 0 or 1. In the above formula (I), R
1, R2, R3, and R4 are either a phenyl group, a xylyl group, or a cresyl group, at least one of which is a xylyl group and at least one is a phenyl group. The polyphenylene ether resin used in the present invention is a homopolymer or a copolymer having a repeating unit represented by the following formula (II-1) and / or (II-2).

[0012]

Embedded image

(Where R5, R6, R7, R8, R
9 and R10 independently represent an alkyl group having 1 to 4 carbon atoms, an aryl group, halogen, or hydrogen. However, R9 and R10 are not hydrogen at the same time. A typical example of the homopolymer of the polyphenylene ether resin is poly (2,6-dimethyl-1,4-phenylene).
Ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4
-Phenylene) ether, poly (2-ethyl-6-n-)
Propyl-1,4-phenylene) ether, poly (2,
6-di-n-propyl-1,4-phenylene) ether, poly (2-methyl-6-n-butyl-1,4-phenylene) ether, poly (2-ethyl-6-isopropyl-1,4-) Examples thereof include phenylene) ether, poly (2-methyl-6-hydroxyethyl-1,4-phenylene) ether, and poly (2-methyl-6-chloroethyl-1,4-phenylene) ether.

The polyphenylene ether resin used in the present invention is poly (2,6-dimethyl-1,4-phenylene).
Ethers are particularly preferred. The copolymer of polyphenylene ether resin means a copolymer having a phenylene ether structure as a main monomer unit. Examples thereof include copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol, copolymers of 2,6-dimethylphenol and o-cresol, or 2,6-dimethylphenol and 2 , 3,6-trimethylphenol and a copolymer with o-cresol.

In the polyphenylene ether resin used in the present invention, various other phenylene ether units, which have been proposed to be present in the polyphenylene ether resin, have been proposed as a partial structure unless it goes against the gist of the present invention. May be included as. As an example of what is proposed to coexist in a small amount, JP-A-1-29 is known.
2- (dialkylaminomethyl) -6 described in JP 7428 and JP-A 63-301222.
-Methylphenylene ether unit, and 2- (N
-Alkyl-N-phenylaminomethyl) -6-methylphenylene ether unit. The polyphenylene ether resin may contain a small amount of diphenoquinone bound in the main chain. further,
Polyphenylene ether resin modified with a compound having a carbon-carbon double bond, for example, JP-A-2-2768.
23, JP-A-63-108059, JP-A-59-59724 and the like may be included.

The production method of the polyphenylene ether resin used in the present invention is not particularly limited. For example, according to the method described in Japanese Patent Publication No. 5-13966, in the presence of a copper amine catalyst, 2 , 6-xylenol can be produced by oxidative coupling polymerization. Also, the molecular weight and the molecular weight distribution are not particularly limited. Polystyrene resin used in the present invention,
A vinyl aromatic polymer, a rubber-modified vinyl aromatic polymer, a block copolymer composed of a vinyl aromatic polymer block and a conjugated diene polymer block, and a part or all of the conjugated diene polymer block is hydrogenated. It refers to a block copolymer or the like composed of a vinyl aromatic polymer block and a conjugated diene polymer block.

Examples of the vinyl aromatic polymer include styrene, o-methylstyrene, p-methylstyrene,
Nuclear alkyl-substituted styrenes such as m-methyl styrene, 2,4-dimethyl styrene, ethyl styrene, p-tert-butyl styrene, and α-alkyl substituted styrenes such as α-methyl styrene and α-methyl-p-methyl styrene. Examples thereof include polymers, copolymers of one or more of these with at least one of other vinyl compounds, and copolymers of two or more of these. Examples of the compound copolymerizable with the vinyl aromatic compound include methyl methacrylate, methacrylic esters such as ethyl methacrylate, acrylonitrile, unsaturated nitrile compounds such as methacrylonitrile, and acid anhydrides such as maleic anhydride. .
Among these polymers, particularly preferable polymers are polystyrene and styrene-acrylonitrile copolymer (hereinafter, referred to as A
S resin).

Examples of the rubber used for the rubber-modified vinyl aromatic polymer include polybutadiene, styrene-butadiene copolymer, polyisoprene, butadiene-isoprene copolymer, natural rubber and ethylene-propylene copolymer. In particular, polybutadiene and styrene-butadiene copolymer are preferable. As the rubber-modified vinyl aromatic polymer, rubber-modified polystyrene (hereinafter referred to as H
IPS) and rubber-modified styrene-acrylonitrile copolymer (hereinafter, ABS resin) are preferable.

Examples of the block copolymer comprising a vinyl aromatic polymer block and a conjugated diene polymer block include a styrene-butadiene block copolymer and a styrene-isoprene block copolymer. Further, as an example of a block copolymer composed of a vinyl aromatic polymer block in which a conjugated diene polymer block is partially or entirely hydrogenated and a conjugated diene polymer block, a part or all of a butadiene portion is hydrogen. Examples thereof include added styrene-butadiene block copolymers, styrene-isoprene block copolymers in which some or all of the isoprene moieties are hydrogenated.

The organic phosphorus compound used as (B) in the present invention is represented by the following formula (I).

[0021]

[Chemical 6]

(However, X in the above formula is a group represented by the following formula,

[0023]

[Chemical 7]

N is a natural number, and j, k, l and m are independently 0 or 1. In the above formula (I), R
1, R2, R3, and R4 are either a phenyl group, a xylyl group, or a cresyl group, at least one of which is a xylyl group and at least one is a phenyl group. ) At least one of the substituents R1, R2, R3, and R4 in the formula (I) is a xylyl group, at least one of the other three is a phenyl group, and the remaining two are phenyl groups, It is selected from either a xylyl group or a cresyl group. When all of R1, R2, R3 and R4 are phenyl groups or cresyl groups, the heat resistance of the resin is lowered. R1,
It is preferred that R2, R3, and R4 are phenyl groups or xylyl groups, at least one of which is a xylyl group, one of which is a phenyl group, and the other two are selected from either a phenyl group or a xylyl group. Further, from the viewpoint of blooming due to hydrolysis and economically, R1 and R
2, R3 and R4 are phenyl groups or xylyl groups,
More preferably, at least one of them is a xylyl group and the remaining three are phenyl groups.

Further, n in the above formula (I) is generally from 1 to 5
Those having an average value of
The average value of 3 is preferable, and the average value of 1 to 2 is particularly preferable. These organic phosphorus compounds may be used alone or in combination of two or more. The polyphenylene ether-based flame-retardant resin composition of the present invention comprises 100 parts by weight of the polyphenylene ether resin (A), or a composition 100 of 10 to 99 parts by weight of the polyphenylene ether resin and 90 to 1 parts by weight of the polystyrene resin. Parts by weight,
It is characterized by comprising 0.1 to 100 parts by weight of the organophosphorus compound (B). If the blending ratio of (B) is too small, the flame retardancy is insufficient, and if it is too large, the heat resistance of the resin is impaired. The organic phosphorus compound is more preferably 0.5 to 50 parts by weight, and most preferably 1 to 30 parts by weight.

The polyphenylene ether flame-retardant resin composition of the present invention contains other additives such as ethylene-propylene elastomer, styrene-grafted ethylene-propylene elastomer, thermoplastic polyester elastomer, and Iomomer, as long as the effects of the present invention are not impaired. Impact strength improvers such as resins, core-shell polymers consisting of rubber-like cores and non-rubber-like shells, anti-drip agents such as Teflon, plasticizers, other flame retardants, antioxidants, and stabilizers such as UV absorbers. Release agents, dyes and pigments, or fibrous reinforcing agents such as glass fibers and carbon fibers, and fillers such as glass beads, calcium carbonate, and talc may be added. The polyphenylene ether flame-retardant resin composition of the present invention is not particularly limited in its production method, and can be kneaded and produced using a kneader such as an extruder, a heating roll, a kneader, and a Banbury mixer.

[0027]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described specifically with reference to examples. The organic phosphorus compounds used in Examples and Comparative Examples were as follows. (B-1): a phosphoric acid ester compound represented by the following formula (III) (average value of n is 1.5)

[0028]

Embedded image

(B-2): Bisphenol A polyphenyl phosphate represented by the following formula (IV) (average value of n: 1.4)

[0030]

Embedded image

(B-3): Resorcinol polyphenyl phosphate represented by the following formula (V) (average value of n: 1.
5)

[0032]

Embedded image

(B-4): Triphenyl phosphate [trade name: TPP manufactured by Daihachi Chemical Co., Ltd.] The polyphenylene ether flame-retardant resin composition was evaluated by the following methods and conditions. (1) Flame retardance: Based on UL standard 94 vertical combustion test method, the test was carried out using 1/8 inch test pieces and ranked. (2) Smoke amount: The amount of smoke generated from the nozzle of the injection molding machine when purging the polyphenylene ether flame-retardant resin composition was visually observed. (3) Stability of composition: The water absorption before and after the hydrolysis acceleration test of the test piece and the change of the dielectric loss tangent as an electrical property were used as the stability index.

In the hydrolysis acceleration test, the test piece was heated at 120 ° C.
It was exposed for 200 hours under 2 atmospheric pressure saturated steam. Water absorption rate: Calculated from the weight change rate of the test piece before and after the hydrolysis acceleration test (wt%). Dielectric loss tangent: 23 ° C., 60 according to ASTM D150
It was measured at Hz. (4) Heat distortion temperature: Load 1 according to ASTM D648
It was measured at 8.6 Kg / cm ² . Melt flow rate (MFR): Measured at 250 ° C. under a load of 10 kg according to JIS K7210.

[0035]

Example 1 As a polyphenylene ether resin, the intrinsic viscosity [η] measured at 30 ° C. in chloroform was 0.47.
67 parts by weight of poly 2,6-dimethyl-1,4-phenylene ether (hereinafter abbreviated as PPE), which is a high-impact polystyrene resin as HIPS [manufactured by Asahi Kasei Kogyo KK:
Product name: Asahi Kasei Polystyrene 492] 24 parts by weight, polystyrene resin (hereinafter abbreviated as GPPS) [Asahi Kasei Industry Co., Ltd .: product name Asahi Kasei Polystyrene 685] 14 parts by weight of the compound (b-1), 1.0 part by weight of zinc oxide, 0.3 part by weight of octadecyl-3- (3-5-di-t-butyl-4-hydroxyphenyl) propionate are mixed, and a cylinder is prepared. Melt kneading was performed with a twin-screw extruder set to a temperature of 300 ° C. to obtain pellets. The pellets were injection-molded and evaluated. The results are shown in Table 1.

[0036]

Example 2 Pellets were obtained and evaluated in the same manner as in Example 1 except that 14 parts by weight of the organophosphorus compound (b-1) was changed to 11 parts by weight, and the results are shown in Table 1. .

[0037]

[Comparative Examples 1 to 3] Each component was mixed in the composition shown in Table 1, molded and evaluated in the same manner as in Example 2, and the results are shown in Table 1.

[0038]

[Table 1]

[0039]

Example 3 100 parts by weight of PPE and 18 parts by weight of the organophosphorus compound (b-1) were kneaded with a twin-screw extruder having a cylinder temperature of 320 ° C. to obtain pellets. The pellets were injection-molded and evaluated. The results are shown in Table 2.

[0040]

Comparative Example 4 The organophosphorus compound (b-1) was added to (b-3)
Molding and evaluation were carried out in the same manner as in Example 3 except that the result was shown in Table 2.

[0041]

[Table 2]

[0042]

EFFECTS OF THE INVENTION The polyphenylene ether flame-retardant resin composition of the present invention is free from volatilization, smoke emission and bleeding of the flame retardant at the time of molding and can be used for a long period of time as compared with the conventional flame-retardant resin composition. It is a flame-retardant resin composition that has excellent stability to withstand recycling and has an excellent balance between heat resistance and molding processability.

Claims (1)

[Claims] 1. The (A) polyphenylene ether resin is 1
00 parts by weight, or polyphenylene ether resin 10
100 parts by weight of a composition of 99 parts by weight and 90 to 1 part by weight of a polystyrene resin, and (B) 1 represented by the following formula (I)
A polyphenylene ether flame-retardant resin composition comprising 0.1 to 100 parts by weight of one or more organic phosphorus compounds. Embedded image (However, X in the above formula is a group represented by the following formula, and n is a natural number, and j, k, l, and m are each independently 0 or 1. Further, in the above formula (I), R1, R2, R
3 and R4 are either a phenyl group, a xylyl group, or a cresyl group, at least one of which is a xylyl group and at least one is a phenyl group. )