JP2001323130A - Method for recycling flame-retardant thermoplastic resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for recycling a flame-retardant thermoplastic resin composition without impairing the flame retardancy and impact resistance after the recycling. SOLUTION: In the recycling of a flame-retardant thermoplastic resin composition (I), which comprises a graft-copolymer (A) containing a rubbery polymer (a), a vinyl (co)polymer (B), a flame retardant (C) and antimony oxide (D), 0.01-5 pts.wt. of a fluororesin (E) is added to 100 pts.wt. of the flame-retardant thermoplastic resin composition (I).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for recycling a flame-retardant thermoplastic resin composition, and more particularly, to a flame-retardant thermoplastic resin composition without impairing the flame retardancy and impact resistance after recycling. About how to recycle.

[0002]

2. Description of the Related Art Styrene-based resins have excellent mechanical properties, moldability and electrical insulation properties, and are therefore used in a wide range of fields including home electric appliances, OA appliances and automobiles. ing.

However, most plastics containing a styrene-based resin are flammable, and various techniques have been devised for flame retardancy due to safety issues.

[0004] Generally, as a method of flame retarding plastics, a chlorine or bromine flame retardant having high flame retarding efficiency and antimony oxide are combined and blended into a resin.
A method of flame retardation is employed.

However, conventional flame-retardant styrenic resin compositions containing chlorine or bromine-based flame retardants cause a decrease in flame retardancy and impact strength at the time of recycling. When the ratio is high, there is a problem that sufficient flame retardancy and impact resistance cannot be obtained.

As a technique for improving the recyclability of a flame-retardant styrenic resin composition, for example, JP-A-7-2904
No. 54 discloses a method of suppressing a decrease in flame retardancy by adding a flame retardant when recycling a flame-retardant polystyrene resin.
There is a problem that the physical properties and color tone of the recycled product are reduced.

[0007]

SUMMARY OF THE INVENTION The present invention has been achieved as a result of studying to solve the problems in the prior art described above.

Accordingly, an object of the present invention is to provide a method for recycling a flame-retardant thermoplastic resin composition without impairing the flame retardancy and impact resistance after recycling.

[0009]

Means for Solving the Problems As a result of intensive studies to solve the above-mentioned problems, the present invention achieves the above object by adding a fluorine-based resin when recycling a styrene-based flame-retardant resin composition. The present invention has been found to be achieved efficiently, and has reached the present invention.

That is, the method for recycling a flame-retardant thermoplastic resin composition of the present invention comprises the steps of:
Graft copolymerization of at least one monomer selected from an aromatic vinyl monomer (b), a vinyl cyanide monomer (c) and another copolymerizable vinyl monomer (d). Selected from the polymerized graft copolymer (A), aromatic vinyl monomer (b), vinyl cyanide monomer (c) and other copolymerizable vinyl monomer (d). The flame-retardant thermoplastic resin composition (I) containing the vinyl (co) polymer (B) comprising at least one monomer, the flame retardant (C) and the antimony oxide (D) is recycled. At this time, 0.01 to 5 parts by weight of a fluororesin (E) is added to 100 parts by weight of the flame-retardant thermoplastic resin composition (I).

In the method for recycling a flame-retardant thermoplastic resin composition of the present invention, the fluorine-containing resin (E)
Is polytetrafluoroethylene, the weight average particle diameter of the rubbery polymer (a) is in the range of 0.1 to 0.5 μm, and the rubbery polymer in the graft copolymer (A) The content of (a) is 20 to 80% by weight, and the monomer composition of the graft copolymer (A) is 10 to 90% by weight of an aromatic vinyl monomer (b), 0 to 50% by weight of vinyl chloride monomer (c) and other copolymerizable vinyl monomer (d) 0 to 90%
% Of the vinyl (co) polymer (B)
The aromatic vinyl monomer (b)
10 to 90% by weight, vinyl cyanide monomer (c) 0
50% by weight and 0 to 90% by weight of another copolymerizable vinyl monomer (d), and the total of the graft copolymer (A) and the vinyl (co) polymer (B) is 10
With respect to 0 parts by weight, the flame retardant (C) is contained in an amount of 1 to 30 parts by weight, and the total of the graft copolymer (A) and the vinyl (co) polymer (B) is 100 parts by weight. The antimony oxide (D) is contained in an amount of 0.5 to 15 parts by weight, and the swell ratio of the flame-retardant thermoplastic resin composition which is recycled by adding the fluororesin (E) is 1.
Any of the ranges of 3 to 3.0 is preferred.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the flame-retardant thermoplastic resin composition of the present invention will be described in detail.

First, in the present invention, a flame-retardant thermoplastic resin composition to be used for recycling will be described.

The base polymer in the flame-retardant thermoplastic resin composition of the present invention is based on the rubbery polymer (a) and the aromatic vinyl monomer (b) and the vinyl cyanide monomer (c).
And a graft copolymer (A) obtained by graft copolymerizing one or more monomers selected from vinyl monomers (d) and other copolymerizable vinyl monomers (d), and an aromatic vinyl monomer (b) ), A vinyl (co) polymer (B) comprising at least one monomer selected from vinyl cyanide monomers (c) and other copolymerizable vinyl monomers (d) And a thermoplastic resin composition comprising:

The rubbery polymer (a) used for the graft copolymer (A) is not particularly limited, and may be a diene rubber, an acrylic rubber, an ethylene rubber, or the like. Specific examples of these rubbery polymers (a) include polybutadiene, poly (butadiene-styrene), poly (butadiene-acrylonitrile), polyisoprene, poly (butadiene-butyl acrylate), and poly (butadiene-methyl methacrylate). , Poly (butyl acrylate-methyl methacrylate), poly (butadiene-ethyl acrylate), ethylene-propylene rubber,
Ethylene-propylene-diene rubber, poly (ethylene-isoprene), poly (ethylene-methyl acrylate) and the like. These rubbery polymers (a)
Are used in one kind or in a mixture of two or more kinds. Among these rubbery polymers (a), polybutadiene, poly (butadiene-styrene), poly (butadiene-acrylonitrile) and ethylene-propylene rubber are:
It is preferably used in terms of impact resistance.

The weight average particle diameter of the rubbery polymer (a) constituting the graft copolymer (A) in the present invention is not particularly limited, but is preferably in the range of 0.1 to 0.5 μm. .

The aromatic vinyl monomer (b) used for the graft copolymer (A) and the vinyl (co) polymer (B) in the present invention is not particularly limited, and specific examples include styrene and α. -Methylstyrene, orthomethylstyrene,
Examples thereof include paramethylstyrene, para-t-butylstyrene, and halogenated styrene, and one or more of these can be used. Among these aromatic vinyl monomers (b), styrene and α-methylstyrene are preferable, and styrene is particularly preferably used.

The vinyl cyanide monomer (c) used for the graft copolymer (A) and vinyl (co) polymer (B) in the present invention is not particularly limited, and specific examples include acrylonitrile and methacrylic. Lonitrile and the like can be mentioned, and these can be used alone or in combination of two or more. Among these vinyl cyanide monomers (c), acrylonitrile is preferably used in terms of impact resistance.

The other copolymerizable vinyl monomer (d) used for the graft copolymer (A) and the vinyl (co) polymer (B) in the present invention is not particularly limited, and specific examples are as follows. Is methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate, t-butyl (meth) acrylate, n-hexyl (meth) acrylate (Meth) acrylate compounds having an alkyl group having 1 to 6 carbon atoms or substituted alkyl groups, such as cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, and 2-chloroethyl (meth) acrylate; Maleimide compounds such as methylmaleimide, N-cyclohexylmaleimide and N-phenylmaleimide; unsaturated dicarboxylic acids such as maleic acid; The like can be illustrated copolymerizable vinyl compounds such as unsaturated amide compounds such as unsaturated dicarboxylic acid anhydride and acrylamide such as maleic acid, these alone to be able to use two or more kinds.

The monomer composition used for the graft copolymer (A) is 10 to 90% by weight of an aromatic vinyl monomer (b) and 0 to 50% by weight of a vinyl cyanide monomer (c). ,
And other copolymerizable vinyl monomers (d)
Preferably it comprises 90% by weight. More preferably,
20 to 80% by weight of an aromatic vinyl monomer (b), 0 to 40% by weight of a vinyl cyanide monomer (c), and 0 to 80 of another copolymerizable vinyl monomer (d) % By weight.

The aromatic vinyl monomer (b) and the vinyl cyanide monomer (c) constituting the vinyl (co) polymer (B) according to the present invention, and other copolymerizable if necessary. There is no particular limitation on the composition of the vinyl monomer (d), but in terms of balance between moldability and impact resistance,
10 to 90% by weight of an aromatic vinyl monomer (b), 0 to 50% by weight of a vinyl cyanide monomer (c), and 0 to 90% of another copolymerizable vinyl monomer (d) % By weight. More preferably, 20 to 80% by weight of an aromatic vinyl monomer (b), 0 to 40% by weight of a vinyl cyanide monomer (c), and another copolymerizable vinyl monomer (d ) 0-80% by weight.

The mixing ratio of the graft copolymer (A) and the vinyl (co) polymer (B) in the present invention is not particularly limited, but the weight ratio of (A) :( B) is 10:90. ~ 60:
Preferably, the ratio is in the range of 40, particularly 20:80 to 50:50.

The content of the rubbery polymer (a) in the graft copolymer (A) is not particularly limited.
It is preferably in the range of ８０80% by weight, especially 35-60% by weight. When the content of the rubbery polymer (a) is less than the above range, the impact strength of the obtained flame-retardant thermoplastic resin composition tends to decrease, and when the content exceeds the above range, the melt viscosity increases. There is a tendency that the moldability deteriorates.

It is not necessary that all of the monomer mixture blended with the graft copolymer (A) be grafted by bonding to the rubbery polymer (a). The monomers may be bonded to each other and contained as a non-grafted polymer. However, the graft ratio is preferably in the range of 10 to 100%, especially 20 to 50%.

Although the reduced viscosity (ηsp / c) of the vinyl (co) polymer (B) in the present invention is not particularly limited, it is 0.1 to 0.8 dl / g, particularly 0.3 to 0.7 dl.
/ G is preferable. If the reduced viscosity is out of the above range, the impact resistance tends to decrease, or the melt viscosity tends to increase, and the moldability tends to deteriorate.

The method for producing the graft copolymer (A) and vinyl (co) polymer (B) in the present invention is not particularly limited, and may be any of bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization. There may be. There is no particular limitation on the method of charging the monomers during production, and any method of initial batch charging, continuous charging of some or all of the monomers, or split charging of some or all of the monomers is used. You may.

The flame retardant (C) used in the present invention comprises:
Although not particularly limited, it is preferable to use an addition type halogen-based flame retardant.

As the halogen-based flame retardant, for example, a brominated bisphenol-based epoxy resin, tetrabromobisphenol A, an oligomer thereof, and a brominated triazine-based flame retardant are preferably used, and the use of a brominated bisphenol-based epoxy resin is more preferable. .

The addition amount of the flame retardant (C) in the present invention is as follows:
1 to 30 parts by weight, especially 3 to 25 parts by weight, based on 100 parts by weight of the total of the graft copolymer (A) and the vinyl polymer (B).
It is preferable that the amount be in the range of parts by weight in terms of balance between flame retardancy, impact resistance, thermal stability and heat resistance. Flame retardant (C)
If the amount is less than the above range, the flame retardancy is not sufficient, and if it exceeds the above range, the mechanical strength and thermal stability of the obtained thermoplastic resin composition tend to decrease.

As the antimony oxide (D) used in the present invention, antimony trioxide and antimony tetroxide are preferable, and antimony trioxide is more preferable.
The method for producing antimony trioxide itself is not particularly limited.

The amount of antimony oxide (D) used in the present invention is 0.5 to 15 parts by weight, especially 1 to 100 parts by weight of the total of the graft copolymer (A) and the vinyl polymer (B). It is preferably in the range of 10 to 10 parts by weight.
If the amount of antimony oxide (D) is less than the above range, the flame retardancy is not sufficient, and if it exceeds the above range, the mechanical strength of the obtained thermoplastic resin composition tends to decrease.

The flame-retardant thermoplastic resin composition (I) of the present invention
There are no particular restrictions on the method for producing the polymer, and the graft copolymer (A), vinyl (co) polymer (B), flame retardant (C)
And antimony oxide (D) can be produced by melt-kneading with, for example, a Banbury mixer, roll, extruder, kneader or the like.

The flame-retardant thermoplastic resin composition (I) of the present invention may contain various thermoplastic resins and elastomers as long as the object of the present invention is not impaired.
The performance can be further improved as a molding resin composition.

The flame-retardant thermoplastic resin composition (I) of the present invention may further comprise, if necessary, an antioxidant such as a hindered phenol compound, a sulfur-containing compound compound, a phosphorus-containing organic compound compound, and the like.
Various stabilizers such as phenol-based, acrylate-based heat stabilizers, benzotriazole-based, benzophenone-based, succinate-based ultraviolet absorbers, organic nickel-based, hindered amine-based light stabilizers, etc., metal salts of higher fatty acids, and higher grades Lubricants such as fatty acid amides, plasticizers such as phthalates and phosphates, flame retardant aids such as antimony trioxide and antimony pentoxide, carbon black, pigments and dyes can also be added.

Further, various reinforcing agents and fillers can be added to the flame-retardant thermoplastic resin composition (I) of the present invention.

The flame-retardant thermoplastic resin composition (I) of the present invention obtained as described above can be used for molding thermoplastic resins such as injection molding, extrusion molding, blow molding, vacuum molding, compression molding and gas assist molding. The molding method itself is not particularly limited. The molded article made of the above flame-retardant thermoplastic resin composition (I) has excellent flame retardancy, impact resistance and thermal stability.

Next, the recycling method of the present invention will be described.

The recycling step in the present invention is not particularly limited. As a typical recycling method, a molded article made of the above flame-retardant thermoplastic resin composition is pulverized, and the pulverized article is subjected to molding again. Method.

However, in the recycling method of the present invention, a fluorinated resin (E) may be added to a pulverized product of the above-mentioned flame-retardant thermoplastic resin composition, mixed, and recycled. Importantly, this makes it possible to minimize a decrease in the flame retardancy and impact resistance of a recycled product made of the above flame retardant thermoplastic resin composition.

The fluororesin (E) used in the present invention is not particularly limited, but polytetrafluoroethylene is preferably used. The polytetrafluoroethylene is not particularly limited, but a powder or an aqueous dispersion is preferably used.

The amount of the fluororesin (E) in the present invention is based on 100 parts by weight of the flame-retardant thermoplastic resin composition.
It is preferably 0.01 to 5 parts by weight, more preferably 0.0 to 5 parts by weight.
It is 5 to 4.5 parts by weight. When the addition amount of the fluororesin (E) is less than the above range, the swell ratio of the flame-retardant thermoplastic resin composition after recycling becomes 1.3 or less, and the flame retardancy is not sufficient. If the ratio exceeds the above, the impact resistance of the flame-retardant thermoplastic resin composition after recycling tends to decrease.

In the recycling method of the present invention, a mixture obtained by adding a fluororesin (E) to a pulverized product of the above-mentioned flame-retardant thermoplastic resin composition and mixing the mixture is directly molded. Alternatively, the mixture can be kneaded and pelletized once with an extruder and then subjected to molding.

The flame-retardant thermoplastic resin composition recycled by the recycling method of the present invention has a swell ratio of 1.3 to 3.0, particularly 1.4, as measured by the method described later.
It is preferably in the range of ~ 2.5. If the swell ratio of the obtained flame retardant resin composition is out of the above range, the flame retardancy of the recycled product becomes insufficient or the impact resistance tends to decrease.

The flame-retardant thermoplastic resin composition recycled by the above method can be used in a known thermoplastic resin molding such as injection molding, extrusion molding, blow molding, vacuum molding, compression molding and gas assist molding. By the above method, a desired molded article can be formed again, and the molding method after recycling is not particularly limited.

The flame-retardant thermoplastic resin composition obtained by the recycling method of the present invention, even after recycling,
Various fields in which flame-retardant resins are widely used and recycled by taking advantage of these excellent features because they maintain the original flame retardancy, impact resistance and thermal stability without loss In particular, it can be suitably used as housings for OA equipment, home electric appliances and the like and their components.

[0046]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In Examples and Comparative Examples, all parts and percentages are by weight unless otherwise specified.

An analysis method for the characteristics of the flame-retardant thermoplastic resin composition will be described below. (1) Weight average rubber particle diameter “Rubber Age Vol.88 p.484-
490 (1960) by E.I. Schmidt, P .;
H. And the sodium alginate method described in "Biddison". That is, utilizing the fact that the particle size of polybutadiene to be creamed differs depending on the concentration of sodium alginate, the cumulative weight fraction of the creamed weight ratio and the cumulative weight fraction of the sodium alginate concentration are 50%.
Was determined. (2) Graft ratio Acetone was added to a predetermined amount (m) of the graft copolymer to obtain 3
After refluxing for 8 hours, the solution
After centrifugation at 0 G) for 40 minutes, the insolubles were collected by filtration, and the insolubles were dried under reduced pressure at 60 ° C. for 5 hours, and the weight (n) was measured. The graft ratio was calculated from the following equation.

Graft ratio (%) = ｛[(n)-(m) ×
L] / [(m) × L]｝ × 100 where L is the rubber content of the graft copolymer. (3) Reduced viscosity ηsp / c 200 ml of acetone was added to 1 g of the sample, refluxed for 3 hours, and the solution was centrifuged at 8800 r / min (10000 G) for 40 minutes, and the insoluble matter was filtered. The filtrate was concentrated with a rotary evaporator, and the precipitate (soluble matter in acetone) was dried under reduced pressure at 60 ° C. for 5 hours.
The volume was adjusted to 00 ml (methyl ethyl ketone, 30 ° C.), and ηsp / c was measured using an Ubbelohde viscometer. (4) Izod impact strength Measured under the conditions of 23 ° C. with a 12.7 mm notch in accordance with the provisions of ASTM D256. (5) MFR (melt flow rate value) Measured in accordance with ISO 1133 (220 ° C., 98 N load). (6) Flame retardancy UL standard 94 method (United States: Underwriters L
laboratories Inc., standard) and the test piece thickness was 1.5 mm. (7) Swell ratio The degree of swelling of the resin sample extruded under the above MFR measurement conditions was measured and evaluated. Specifically, the above MFR
After extruding the resin by 50 mm under the measurement conditions described above, the resin is cut out and placed on a flat surface. After standing for 5 minutes, the diameter of the central portion (25 mm from both ends) of the resin sample was measured. The measurement was performed twice, the average value was calculated, and the average value was calculated by the following equation.

Swell ratio = [extruded resin sample diameter (average value of two times)] / [orifice diameter (2.095 m
m)] [Reference Example 1] Method for producing graft copolymer (A) In a reactor purged with nitrogen, 120 parts of pure water and 0.5 part of glucose were added.
Part, sodium pyrophosphate 0.5 part, ferrous sulfate 0.0
05 parts and polybutadiene latex (rubber particle diameter 0.3 μm, gel content 85%) 60 parts (solid content conversion)
And the temperature inside the reactor was raised to 65 ° C. while stirring. Monomer (30 parts of styrene and 10 parts of acrylonitrile) is defined as the start of polymerization when the internal temperature reaches 65 ° C.
And a mixture consisting of 0.3 parts of t-dodecyl mercaptan was continuously dropped over 5 hours. At the same time, an aqueous solution consisting of 0.25 parts of cumene hydroperoxide, 2.5 parts of potassium oleate and 25 parts of pure water was continuously added dropwise over 7 hours to complete the reaction.

The obtained styrene-based graft copolymer latex was coagulated with sulfuric acid, neutralized with caustic soda, washed, filtered and dried to obtain a graft copolymer (A) A1. The graft ratio of this styrene-based copolymer (A) A1 is 35%,
Ηsp / c of the resin component was 0.35 dl / g. Reference Example 2 Method for Producing Vinyl (Co) polymer (B) A 20-L capacity stainless steel autoclave equipped with a baffle and a Faudra-type stirring blade was composed of 20% by weight of methyl methacrylate and 80% by weight of acrylamide. A solution prepared by dissolving 0.05 part of the copolymer in 165 parts of ion-exchanged water was charged, stirred at 400 rpm, and the system was replaced with nitrogen gas. Next, acrylonitrile 30 parts, styrene 5.0 parts, t-dodecyl mercaptan 0.46 parts, 2,
2'-azobis (2,4-dimethylvaleronitrile)
A mixed solution of 0.39 parts and 0.05 parts of 2,2′-azobisisobutylnitrile was added while stirring the reaction system, and the temperature was raised to 58 ° C. to initiate polymerization. 15 from the start of polymerization
After a lapse of minutes, 65 parts of styrene from a feed pump provided at the top of the autoclave was added over 110 minutes. During this time, the reaction temperature was raised to 65 ° C. After the addition of styrene to the reaction system was completed, the temperature was raised to 100 ° C. over 50 minutes.

Thereafter, the reaction system was cooled, the polymer was separated, washed, and dried according to a conventional method to obtain a vinyl (co) polymer (B) B1. This vinyl (co)
Ηsp / c of the polymer (B) B1 was 0.53 dl / g. [Reference Example 3] Flame retardant (C) Brominated bisphenol epoxy resin "Prasam" E
PR-16 (manufactured by Dainippon Ink and Chemicals, Inc.) was prepared. Reference Example 4 Antimony oxide (D) Antimony trioxide "Timonox" (manufactured by AZON) was prepared. Reference Example 5 Fluorine-based resin (E) The following two types of fluorinated resins were prepared.

<E-1> Polytetrafluoroethylene "Polyflon" D-2C
(Manufactured by Daikin Industries, Ltd.) Particle size of 0.15 to 0.35 μm, 60% aqueous solution <E-2> polytetrafluoroethylene “Polyflon”
F201 (manufactured by Daikin Industries, Ltd.) Particle size (secondary) measured by ASTM D1457: 0.5 m
m. [Examples 1 to 3] Table 1 shows the graft copolymer (A), vinyl (co) polymer (B), flame retardant (C) and antimony oxide (D) shown in Reference Examples. The mixture is mixed at a mixing ratio, and the mixture is melt-kneaded and extruded at a resin temperature of 230 ° C. using a vented 30 mmφ twin-screw extruder (Ikegai PCM-30) to obtain a pellet-shaped flame-retardant thermoplastic resin composition. Manufactured.

Next, a test piece was molded by an injection molding machine under the conditions of a cylinder temperature of 230 ° C. and a mold temperature of 60 ° C.
The measurement results (initial characteristics) obtained by measuring the physical properties under the above conditions are also shown in Table 1.

Further, the injection-molded test piece was pulverized with a pulverizer, and the pulverized product was mixed with the fluorine resin (E) at the compounding ratio shown in Table 1, and a 30 mmφ twin-screw extruder with vent (PCM manufactured by Ikegai Co., Ltd.) Using -30), the mixture was melt-kneaded at a resin temperature of 230 ° C. and extruded to produce a pellet-shaped flame-retardant thermoplastic resin composition.

Next, a test piece was molded by an injection molding machine under the conditions of a cylinder temperature of 230 ° C. and a mold temperature of 60 ° C.
Physical properties were measured under the above conditions, and the obtained measurement results (recycling characteristics) are shown in Table 1. [Comparative Examples 1 to 6] The graft copolymer (A), vinyl (co) polymer (B), flame retardant (C) and antimony oxide (D) shown in Reference Example were blended as shown in Table 1. Table 1 also shows the measurement results (initial characteristics) obtained by mixing at a ratio and measuring each physical property in the same manner as in the examples.

Further, the injection-molded test piece was pulverized with a pulverizer, and the pulverized product was mixed with the fluororesin (E) at the compounding ratio shown in Table 1 or without mixing.
A pellet-shaped flame-retardant thermoplastic resin composition was produced by melt-kneading and extruding at a resin temperature of 230 ° C. using a 0 mm φ twin-screw extruder (PCM-30 manufactured by Ikegai).

Next, a test piece was molded by an injection molding machine under the conditions of a cylinder temperature of 230 ° C. and a mold temperature of 60 ° C.
Physical properties were measured under the above conditions, and the obtained measurement results (recycling characteristics) are shown in Table 1.

[0058]

[Table 1] From the results in Table 1, the following is clear.

That is, the flame-retardant thermoplastic resin composition obtained by the recycling method of the present invention (Examples 1 to 3)
All have the same flame retardancy after recycling as the initial physical properties, and are also excellent in impact resistance.

On the other hand, the amount of addition of the fluororesin (E) is 0.1.
Those having less than 01 parts by weight (Comparative Example 1) had a swell ratio of 1.3 or less and were inferior in flame retardancy after recycling.
When the amount exceeds part by weight (Comparative Example 2), the impact resistance is poor.

When the amount of the flame retardant (C) added was less than 1 part by weight (Comparative Example 4), the flame retardancy was initially inferior. Poor sex.

When the amount of antimony oxide (D) was less than 0.5 part by weight (Comparative Example 5), the flame retardancy was inferior from the beginning.

[0063]

As described above, the flame-retardant thermoplastic resin composition obtained by the recycling method of the present invention has the inherent flame retardancy, impact resistance and thermal stability even after recycling. Utilizing these excellent features, flame-retardant resins are widely used and recycled for various fields, especially housings for OA equipment, home electric appliances, etc., and parts thereof, because they are maintained without loss. Can be suitably used.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) C08L 27/12 C08L 27/12 63/00 63/00 A // B29K 25:00 B29K 25:00 33:18 33: 18 96:02 96:02 F term (reference) 4F301 AA05 AA07 AA15 AA20 AB01 AD06 AD10 BB02 BB04 BB05 BC16 BE15 BF15 BF32 4J002 BC04X BC06X BD124 BD154 BN06W BN12W BN15W BN16W CD123 DE126 FD090 FD133 FD136

Claims (8)

[Claims] 1. An aromatic vinyl monomer (b), a vinyl cyanide monomer (c) and another copolymerizable vinyl monomer (d) are added to the rubbery polymer (a). ), A graft copolymer (A) obtained by graft copolymerizing one or more monomers selected from the group consisting of an aromatic vinyl monomer (b), a vinyl cyanide monomer (c) and other It contains a vinyl (co) polymer (B) composed of one or more monomers selected from copolymerizable vinyl monomers (d), a flame retardant (C) and antimony oxide (D). When recycling the flame-retardant thermoplastic resin composition (I), 0.01 to 5 parts by weight of the fluororesin (E) is added to 100 parts by weight of the flame-retardant thermoplastic resin composition (I). A method for recycling a flame-retardant thermoplastic resin composition. 2. The method for recycling a flame-retardant thermoplastic resin composition according to claim 1, wherein the fluororesin (E) is polytetrafluoroethylene. 3. The rubbery polymer (a) has a weight average particle diameter in the range of 0.1 to 0.5 μm, and the rubbery polymer (a) in the graft copolymer (A) The content is 20 to 80% by weight.
Or the recycling method of the flame-retardant thermoplastic resin composition according to 2. 4. The monomer composition constituting the graft copolymer (A) is an aromatic vinyl monomer (b) 10 to 90.
% By weight, 0 to 50% by weight of vinyl cyanide monomer (c)
And other copolymerizable vinyl monomers (d)
The method for recycling a flame-retardant thermoplastic resin composition according to any one of claims 1 to 3, comprising 90% by weight. 5. The monomer composition constituting the vinyl (co) polymer (B) is an aromatic vinyl monomer (b) 10 to 10.
90% by weight, 0 to 50% by weight of a vinyl cyanide monomer (c) and another copolymerizable vinyl monomer (d)
5. The composition according to claim 1, comprising 0 to 90% by weight.
The method for recycling a flame-retardant thermoplastic resin composition according to any one of the above. 6. The flame retardant (C) is contained in an amount of 1 to 30 parts by weight based on a total of 100 parts by weight of the graft copolymer (A) and the vinyl (co) polymer (B). A method for recycling the flame-retardant thermoplastic resin composition according to any one of claims 1 to 5. 7. The antimony oxide (D) is contained in an amount of 0.5 to 15 parts by weight based on 100 parts by weight of the total of the graft copolymer (A) and the vinyl (co) polymer (B). The method for recycling the flame-retardant thermoplastic resin composition according to any one of claims 1 to 6, characterized in that: 8. The swell ratio of the flame-retardant thermoplastic resin composition added with the fluorine-based resin (E) and recycled is in the range of 1.3 to 3.0.
A method for recycling the flame-retardant thermoplastic resin composition according to any one of claims 1 to 7.