JPH08225709A - Flame-retardant thermoplastic resin composition - Google Patents

Abstract

PURPOSE: To obtain the subject composition free from occurrence of gelation, excellent in thermal stability, light resistance and flame retardancy and useful for OA equipment, etc., by blending a specific resin mixture with a specific halogenated epoxy compound and an antioxidant. CONSTITUTION: This composition is obtained by blending (A) 100 pts.wt. of a resin mixture comprising 10-80 pts.wt. graft copolymer obtained by carrying out graft copolymerization of a monomer mixture consisting of 60-100wt.% aromatic vinyl monomer (A1 ) with 0-40wt.% monomer (A,) copolymerizable with the component A. and 20-90 pts.wt. copolymer obtained by copolymerizing 60-100wt.% component A1 with 0-40wt.% component A, with (B) 5-30 pts.wt. compound of the formula [R is isopropylidene, methylene or sulfone group; X is Br or Cl; (n) is 0-15; (a), (b), (c) and (d) are each 1-4] and (C) 0.5-10 pts.wt. hindered phenol-based or thioether-based antioxidant.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flame-retardant thermoplastic resin composition having excellent thermal stability. More specifically, flame retardancy,
The present invention relates to a thermoplastic resin composition having excellent heat stability and light resistance.

[0002]

2. Description of the Related Art Rubber-modified styrenic resins represented by ABS, HIPS, etc. are widely used for electric appliances, office automation equipment, office equipment, etc. because of their excellent molding processability, mechanical properties, and appearance. ing. In these applications, it is often necessary to make the resin flame-retardant due to problems such as heat generation and ignition of internal parts. Therefore, organic compounds containing halogen elements such as bromine and chlorine are used as flame retardants. In recent years, in electric appliances such as computers and facsimiles, in order to prevent discoloration due to natural light and light from fluorescent lamps, in addition to flame retardancy and impact resistance, light resistance is required.
For example, JP-A-61-211354 discloses a technique for obtaining a light-resistant and flame-retardant thermoplastic resin by using a halogenated epoxy compound having epoxy groups at both ends as a flame retardant.

However, when the halogenated epoxy compound as described above is used, the gelling reaction of the epoxy compound occurs during the kneading / molding process, so that the melt fluidity is lowered.
There has been a problem that defective phenomena such as coloring and carbonization of the resin occur and the thermal stability decreases. In order to solve such a problem, in JP-A-1-101350, a basic inorganic compound such as hydrotalcite is added together with a halogenated epoxy compound having an epoxy group at an end and antimony trioxide to improve thermal stability. However, there is a problem that impact resistance decreases due to the addition of these filler components, and that defects such as silver streak occur during molding because these compounds are hydrates. there were. Further, Japanese Patent Application Laid-Open No. 6-93156 discloses a technique for improving thermal stability by adding zeolite and a metal salt of ethylenediaminetetraacetic acid together with a halogenated epoxy compound having an epoxy group at the terminal, but zeolite is also inorganic. It is a hydrate of the compound and had the same problems in molding as hydrotalcite.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a flame-retardant thermoplastic resin composition excellent in light resistance, which contains a halogenated epoxy compound having epoxy groups at both ends as described above, and has excellent thermal stability. It is an object of the present invention to provide a composition having the above, particularly, in which the gelling reaction during heat retention in the molding machine is suppressed. As a result of intensive studies to solve the above problems, the present inventors have found that the halogenated epoxy is added by adding a hindered phenol-based and / or thioether-based antioxidant in a large amount as compared with the conventional amount. The effect of suppressing the gelation reaction of the compound and remarkably improving the thermal stability of the thermoplastic resin composition containing the epoxy compound was found, and the present invention was completed.

[0005]

That is, the present invention provides (A)
A monomer mixture of 60 to 100% by weight of an aromatic vinyl monomer and 0 to 40% by weight of a monomer copolymerizable with the aromatic vinyl monomer is graft-copolymerized in the presence of a rubbery polymer. 10 to 80 parts by weight of the graft copolymer, (B) 60 to 100% by weight of the aromatic vinyl monomer and 0 to 40% by weight of the monomer copolymerizable with the aromatic vinyl monomer are polymerized. To 100 parts by weight of a resin mixture consisting of 20 to 90 parts by weight of the following copolymer (C):

[0006]

Embedded image

(Wherein n is an integer of 0 to 15, R is an isopropylidene group, a methylene group or a sulfone group, X is bromine or chlorine, and a, b, c and d are integers of 1 to 4). 5 to 30 parts by weight of a halogenated epoxy compound having an epoxy group at the terminal and 0.5 to 1 of (D) a hindered phenol-based and / or thioether-based antioxidant
It is a flame-retardant thermoplastic resin composition having excellent thermal stability, which is characterized by containing 0 part by weight.

Hereinafter, the present invention will be described in detail. The graft copolymer (A) used in the present invention means a mixture of 60 to 100% by weight of an aromatic vinyl monomer and 0 to 40% by weight of a monomer copolymerizable with the aromatic vinyl monomer, A graft copolymer obtained by graft copolymerization in the presence of a rubbery polymer having a glass transition temperature of 0 ° C or lower, preferably -20 ° C or lower. In order for the resin composition of the present invention to have excellent physical properties, flame retardancy, and processability, the rubber weight average particle diameter contained in the graft copolymer (A) is 0.10 to 10.
It is preferably 4.0 μm, and the rubber content is 10 to 10.
Preferably, it is 70% by weight. If these values are below the above range, the impact resistance of the resin finally obtained may be lowered, and if above these ranges, the flame retardancy of the resin finally obtained may be lowered.

The rubbery polymer used in the graft copolymer (A) is one having a glass transition temperature of 0 ° C. or lower, preferably −20 ° C. or lower. For example, polybutadiene and
Examples thereof include a rubbery polymer made of a copolymer of butadiene and another copolymerizable monomer. Specific examples of the aromatic vinyl monomer that is a constituent of the graft copolymer include
Examples thereof include styrene, α-methylstyrene, vinyltoluene and the like. These may be one kind or a mixture of two or more kinds.

Specific examples of the monomer copolymerizable with the aromatic vinyl monomer include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, maleic anhydride and N-.
Examples thereof include acrylic monomers such as phenylmaleimide, acrylic acid, methacrylic acid and their alkyl esters. These may be one kind or a mixture of two or more kinds.

The ratio of the aromatic vinyl monomer component in the monomer mixture used for the graft copolymer (A) is 60-1.
The range is 00% by weight. If it is less than 60% by weight, heat resistance, impact resistance, color tone and the like of the obtained resin composition are deteriorated.

Specific examples of the graft copolymer (A) include high impact polystyrene (HIPS resin), acrylonitrile / butadiene / styrene copolymer (ABS resin), methyl methacrylate / butadiene / styrene copolymer (MBS resin). ), Methyl methacrylate-acrylonitrile-butadiene-styrene copolymer (MABS
Resin), acrylonitrile / acrylic rubber / styrene copolymer (AAS resin), acrylonitrile / EPDM rubber / styrene copolymer (AES resin), acrylonitrile / chlorinated polyethylene / styrene copolymer (ACS resin), or the like, or These mixtures are mentioned. The graft copolymer (A) can be obtained by batch-processing the above-mentioned monomer or a mixture of the monomers by a known method such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method or a bulk polymerization method. It can be manufactured in a continuous or continuous manner.

The copolymer (B) used in the present invention is
A copolymer obtained by polymerizing 60 to 100% by weight of an aromatic vinyl monomer component and 0 to 40% by weight of a monomer component copolymerizable with an aromatic vinyl monomer. Specific examples of the aromatic vinyl monomer that is a constituent of the copolymer (B) include styrene, α-alkylstyrene such as α-methylstyrene, and p.
-Nucleus-substituted alkylstyrenes such as methylstyrene, vinylnaphthalene and the like can be mentioned. These may be one kind or a mixture of two or more kinds.

Specific examples of the monomer copolymerizable with the aromatic vinyl monomer, which is a constituent of the copolymer (B), include vinyl cyanide monomers such as acrylonitrile and methacrylonitrile, and acryl. Acid, methacrylic acid, and (meth) acrylate-based monomers such as alkyl esters thereof,
Examples thereof include acid anhydride monomers such as maleic anhydride and its imidized product n-phenylmaleimide. These may be one kind or a mixture of two or more kinds.

The ratio of the aromatic vinyl monomer component in the copolymer (B) is in the range of 60 to 100% by weight.
If it is less than 60% by weight, the heat resistance, impact resistance, color tone and the like of the obtained resin composition are deteriorated. This copolymer (B)
For example, according to a known technique for producing an acrylonitrile-styrene copolymer, using a method such as an emulsion polymerization method, a suspension polymerization method, a solution polymerization method, or a bulk polymerization method, a batch method or a continuous method. You can Further, the copolymer (B)
Can be simultaneously produced in the same polymerization system in the polymerization operation of the graft copolymer (A), or can be produced by separately setting the polymerization method and the polymerization conditions.

The blending ratio of each resin in the resin composition of the present invention is 10 to 80% by weight of the graft copolymer (A),
It should be in the range of 20 to 90% by weight of the copolymer (B). If the amount is out of this range, the resin composition obtained cannot have sufficient flame retardancy and physical properties. When the graft copolymer (A) or the copolymer (B) is produced by emulsion polymerization, a resin composition having a smaller residual amount of fatty acid or metal salt derived from an emulsifier, a salting-out agent, etc. It is preferable because thermal stability and mechanical strength are improved.

If desired, any other resin may be further added to the resin composition of the present invention. Examples of other resins that can be added include polycarbonate resins, polybutylene terephthalate resins, and polyethylene terephthalate resins. These are one or two
It may be a mixture of two or more species.

The halogenated epoxy compound (C) having an epoxy group at the terminal used in the present invention is a reaction product of halogenated bisphenol, diglycidyl ether of halogenated bisphenol or its epihalohydrin, and has the following general formula:

[0019]

[Chemical 4]

(Wherein n is an integer of 0 to 15, R is an isopropylidene group, a methylene group or a sulfone group, X is bromine or chlorine, and a, b, c and d are integers of 1 to 4). expressed.

Specific examples of the halogenated bisphenol include tetrabromobisphenol A, dibromobisphenol A, tetrachlorobisphenol A, dichlorobisphenol A, tetrabromobisphenol F, dibromobisphenol F, tetrachlorobisphenol F,
Dichlorobisphenol F, tetrabromobisphenol S, dibromobisphenol S, tetrachlorobisphenol S, dichlorobisphenol S and the like can be mentioned. These may be one kind or a mixture of two or more kinds.

The degree of polymerization n of the halogenated epoxy compound (C) must be an integer of 0-15. Polymerization degree n is 1
When it exceeds 5, the impact resistance and light resistance of the obtained resin composition are deteriorated. Two or more kinds having different polymerization degrees n may be used in combination. The addition amount of the halogenated epoxy compound (C) is 5 to 100 parts by weight of the mixture of the copolymers (A) and (B).
It is 30 parts by weight, preferably 10 to 30 parts by weight. If the amount added exceeds 30 parts by weight, not only is it economically disadvantageous, but the physical properties of the resulting resin composition deteriorate. If the amount added is less than 5 parts by weight, sufficient flame retardancy cannot be imparted to the resin composition obtained.

As the antioxidant (D) used in the present invention, those commonly used as antioxidants for hindered phenol type and / or thioether type resins can be used.

The former is an organic compound having a hindered phenol structure, and suppresses the gelation reaction by trapping radicals such as halogen radicals which can be an initiator of the gelation reaction of the halogenated epoxy compound (C), It has the effect of improving the thermal stability of the obtained resin composition.
As a specific example, triethylene glycol-bis [3-
(3-t-Butyl-5-methyl-4-hydroxyphenyl) propionate, 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], pentaerythritol -Tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 2,2-thio-diethylenebis [3- (3,5-di-t-butyl-4-hydroxyphenyl) ) Propionate], octadecyl-3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate etc. can be mentioned. In particular, hindered phenolic antioxidants that also have metal deactivating ability have a high effect of suppressing the gelation reaction.
2'-oxamidobis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], N,
Specific examples include N'-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyl] hydrazine.

The latter is an organic compound having a thioether bond, and specific examples thereof include antioxidants such as dilaurylthiodipropionate, distearylthiodipropionate and dimyristylthiodipropionate.
The antioxidant (D) may be one kind or a mixture of two or more kinds, and a hindered phenol-based antioxidant and a thioether-based antioxidant may be used in combination.

When the antioxidant (D) is used for the purpose of preventing oxidative deterioration of the resin, it is 0.01 per 100 parts by weight of the resin.
The conventional use method was to add about 0.2 parts by weight, but in the present invention, the effect of the present invention becomes clear for the first time by adding an extremely large amount as compared with the conventional antioxidant. Therefore, 0.5 to 10 parts by weight, preferably 1 to 10 parts by weight is added to 100 parts by weight of the mixture of the graft copolymer (A) and the copolymer (B). Must. If the addition amount exceeds 10 parts by weight, not only is it economically disadvantageous, but the physical properties of the obtained resin composition deteriorate, and if the addition amount is less than 0.5 parts by weight, the thermal stability of the obtained resin composition is high. Can not be improved.

In the resin composition according to the present invention, the graft copolymer (A), the copolymer (B), the halogenated epoxy compound (C) and the antioxidant (D) are weighed within the above range,
It is obtained by mixing and kneading by a known method. For example, a mixture of the respective constituents in the form of powder, beads, flakes or pellets is passed through an extruder such as a single-screw extruder or a twin-screw extruder, or a kneader such as a Banbury mixer, a pressure kneader or a two-roll mill. A resin composition can be obtained by melt-kneading. When it is necessary to mix liquid components, kneading may be performed by the above method using a known liquid injection device. Further, in that case, if necessary, the type and amount of the lubricant, the release agent, the colorant, the antistatic agent, the antioxidant, the other flame retardant, which do not substantially impair the properties of the resin composition of the present invention,
Flame retardant aids such as antimony trioxide, drip (dripping of fire species during combustion) inhibitors, UV absorbers, light resistance stabilizers,
Various resin additives such as a heat resistance stabilizer, a filler and a reinforcing material can be appropriately combined and added.

[0028]

EXAMPLES The present invention will now be specifically described based on examples, but the present invention is not limited to the following examples unless it exceeds the gist. In the following examples, "parts" means "parts by weight".

(1) Production of Graft Copolymer (A) In a reactor having a capacity of 5 L equipped with a stirrer, a heating / cooling device, each raw material and an auxiliary material charging device, 0.25 with acetic anhydride was used.
100 parts of a conjugated diene rubber latex having an enlarged particle size of μm as a solid content and 270 parts of deionized water (including water in the latex) were charged, and the temperature was raised to 70 ° C. During the temperature increase, at 60 ° C., 1.0 part of sodium pyrophosphate dissolved in 45 parts of water, 0.5 part of dextrose and 0.01 part of ferrous sulfate were added. 2.5 when the temperature reaches 70 ℃
Over time, 70 parts styrene, 30 parts acrylonitrile,
1.1 parts of t-dodecyl mercaptan, and 0.5 parts of cumene hydroperoxide, 1.8 parts of disproportionated potassium rosinate soap, 0.37 parts of potassium hydroxide, and 3 parts of deionized water.
5 parts were added. After the addition was completed, the reaction was continued for another 30 minutes and cooled to complete the reaction.

After adding 5 parts of an antioxidant to this graft copolymer latex, it was added to an aqueous magnesium sulfate solution heated at 95 ° C. with stirring to coagulate, and the coagulated product was washed with water and dried to give a white powdery graft copolymer. A polymer resin composition was obtained.

(2) Copolymer (B) Styrene / acrylonitrile = 70/30 weight polymerization ratio and a molecular weight of 120,000 were used.

(3) Halogenated Epoxy Compound (C) A commercially available tetrabromobisphenol A type epoxy oligomer (manufactured by Dainippon Ink and Chemicals, Inc., trade name Platherm EP-13) was used. The structural formula is shown below.

[0033]

Embedded image

(However, a mixture of n = 0 and 1) (4) Antioxidant (D) a) Octadecyl-3- (3,5-di-t-butyl-4)
-Hydroxyphenyl) propionate A commercially available hindered phenolic antioxidant (manufactured by Yoshitomi Pharmaceutical Co., Ltd., trade name Tominox SS) was used (hereinafter abbreviated as "AO-1"). The structural formula is shown below.

[0035]

[Chemical 6]

B) Triethylene glycol-bis [3-
(3-t-Butyl-5-methyl-4-hydroxyphenyl) propionate A commercially available hindered phenolic antioxidant (manufactured by Nippon Ciba-Geigy Co., Ltd., trade name Irganox 245) was used (hereinafter referred to as “AO-2”). Is abbreviated as "). The structural formula is shown below.

[0037]

[Chemical 7]

C) 2,2'-oxamidobis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] A commercially available hindered phenol-based antioxidant / metal deactivator (manufactured by Uniroyal Chemical Co., Ltd., trade name Naugard XL-1) was used (hereinafter abbreviated as “AO-3”). The structural formula is shown below.

[0039]

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D) Distearyl thiodipropionate Commercially available thioether type antioxidant (Yoshitomi Pharmaceutical Co., Ltd.)
Manufactured by the trade name DSTP "Yoshitomi") was used (hereinafter abbreviated as "AO-4"). The structural formula is shown below.

[0041]

[Chemical 9]

(5) Phosphorus Stabilizer (E) As a comparative example, a commercially available phosphorus stabilizer having the following structural formula (manufactured by Sanko Chemical Co., Ltd., trade name HCA) was used.

[0043]

[Chemical 10]

(6) Antimony trioxide (F) As the flame retardant auxiliary, commercially available antimony trioxide (trade name: Ultra Fine 2 manufactured by Laurel Industry Co., Ltd.) was used.

Examples 1 to 6 and Comparative Examples 1 to 3 The above graft copolymer (A), copolymer (B), halogenated epoxy compound (C), antioxidant (D), phosphorus stabilizer (E) and antimony trioxide (F) were weighed and mixed in the blending ratio (parts by weight) shown in Table 1. 70 g of the above resin mixture was kneaded at a rotation speed of 100 rpm by using a kneading torque measuring machine (Plasticorder manufactured by C. W. Brabender Instruments Co., Ltd.), and the resin was hardened and the kneading torque rapidly increased. The maximum value of the torque at that time and the kneading time (gelling time) until reaching the maximum value were measured. The heat coloring property was judged by visually observing the coloring of the compound after kneading. The results are shown in Table 1.

[0046]

[Table 1]

From Table 1, the resin composition according to the present invention is
By adding a hindered phenol-based or thioether-based antioxidant in a larger amount than the conventional amount, the gelation reaction of the halogenated epoxy compound is suppressed, the kneading torque is low, and the kneading time can be extended. In addition, it is understood that the coloration during heating is suppressed, and that it has extremely excellent processing heat stability (Examples 1 to 6). On the other hand, a gelling reaction was observed when no hindered phenol-based or thioether-based antioxidant was added (Comparative Example 1), and when a phosphorus-based stabilizer was added as a stabilizer, a vigorous gelation reaction occurred at the same time. It can be seen that the thermal stability of the resin composition is reduced (Comparative Example 2). Further, it can be seen from Comparative Example 3 that the conventional use amount (0.2 parts by weight) as the antioxidant has no effect on improving the thermal stability.

[0048]

The resin composition of the present invention comprises a mixture of a graft copolymer (A) and a copolymer (B), and a halogenated epoxy compound (C) and a hindered phenol-based and / or thioether-based oxidation. By blending the inhibitor (D), it can be used as a flame-retardant thermoplastic resin material that does not cause gelation reaction and has extremely excellent thermal stability, and its industrial utility value is extremely high. .

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08K 5/36 C08K 5/36 C08L 25/02 LDW C08L 25/02 LDW LDY LDY LEA LEA 55/02 LMC 55/02 LMC LME LME LMF LMF 63/00 NJN 63/00 NJN

Claims (3)

[Claims] 1. (A) 60 to 100% by weight of an aromatic vinyl monomer and 0 to 0 a monomer copolymerizable with the aromatic vinyl monomer.
10 to 80 parts by weight of a graft copolymer obtained by graft copolymerizing 40% by weight of a monomer mixture in the presence of a rubbery polymer, (B) 60 to 100% by weight of an aromatic vinyl monomer, and an aromatic compound. To 100 parts by weight of a resin mixture consisting of 20 to 90 parts by weight of a copolymer obtained by polymerizing 0 to 40% by weight of a monomer copolymerizable with a vinyl group monomer, (C) the following general formula: (In the formula, n is an integer of 0 to 15, R is an isopropylidene group, a methylene group or a sulfone group, X is bromine or chlorine, a,
b, c, d show the integer of 1-4. ) A halogenated epoxy compound having an epoxy group at the terminal represented by
0 parts by weight, and (D) 0.5 to 10 parts by weight of a hindered phenol-based and / or thioether-based antioxidant are blended, and a flame-retardant thermoplastic resin composition having excellent thermal stability. Stuff. 2. A halogenated epoxy compound (C) is represented by the following formula: The flame-retardant thermoplastic resin composition according to claim 1, which is represented by the formula (n represents a mixture of 0 and 1). 3. The flame-retardant thermoplastic resin according to claim 1 or 2, which comprises 1 to 10 parts by weight of (D) a hindered phenol-based and / or thioether-based antioxidant. Composition.