JPH08165415A - Flame retardant resin composition - Google Patents

Abstract

PURPOSE: To obtain a flame retardant resin composition, capable of imparting a high level of flame retardance to a thin wall while retaining the balance between the fluidity and mechanical strength and thermal stability thereof and useful as household appliances, etc., by using a flame retardant having a specific structure and a polytetrafluoroethylene resin together in diantimony trioxide. CONSTITUTION: This composition is obtained by blending (A) 100 pts.wt. composition of (i) 50-90wt.% polycarbonate resin and (ii) 50-10wt.% rubber-modified styrenic resin containing a vinyl cyanide monomer as a copolymer component with (B) 5-30 pts.wt. high-halogen polymeric flame retardant of formula I (n) is the average degree of polymerization and 20-50; R1 and R2 are each H, an alkyl, epoxypropyl, an aryl or formula II [(m) is 0-3] having 45-60wt.% bromine content based on the weight of the flame retardant and 10000-100000g/mol epoxy equiv.}, (C) 0.5-15 pts.wt. diantimony trioxide and (D) 0.01-2 pts.wt. polytetrafluoroethylene resin. Furthermore, the MFIs of the respective components (A) and (B) are preferably 5-12g/10min and 20-40g/10min.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a flame-retardant resin composition. More specifically, it has a particularly good fluidity and thermal stability of mechanical strength for the production of a thin-walled molded product,
The present invention relates to a resin composition having high flame retardancy that satisfies V-0 of the L-94 standard.

[0002]

2. Description of the Related Art A resin composition comprising a polycarbonate resin and a rubber-modified styrene-based resin (hereinafter referred to as "rubber-modified styrene-based resin") containing a vinyl cyanide monomer as an essential copolymer component is a known material. This resin composition is widely used as a housing material for various mechanical parts and electric parts, particularly home electric appliances and OA equipment. In recent years, however, the tendency toward thinning of molded products has been accelerated in such applications. High fluidity, mechanical properties, and flame retardancy are becoming essential requirements.

In order to impart a high degree of flame retardancy to the above resin composition so that the resin composition has a thickness of 2 mm or less and satisfies V-0 of UL-94, a flame retardant aid is added together with an organic halogen-containing flame retardant. It is necessary to use agents together, and generally diantimony trioxide is widely used as a flame retardant auxiliary. However, diantimony trioxide has the disadvantage that the polycarbonate resin is severely degraded / deteriorated when heated and melted, so that the fluidity of the composition fluctuates greatly during injection molding, making stable molding difficult. It has problems such as deterioration of mechanical properties and remarkable generation of silver strips. In particular, when a thin and large-area molded product such as an OA equipment housing is injection-molded, it is necessary to set a high resin temperature and set a long molding cycle, so that the above-mentioned problems become conspicuous and an increase in defective rate cannot be avoided.

For the purpose of improving this point, for example, Japanese Patent Publication No. 1-21184 discloses a technique of using diantimony trioxide whose surface is treated with alkoxysilane. However, according to the experiments conducted by the present inventors, it cannot be said that this method can obtain sufficient thermal stability of the final composition, and there is a drawback that the number of steps is increased.
Further, it is known that the degradation of the polycarbonate resin can be suppressed by using antimony tetroxide or diantimony pentoxide having different oxidation numbers of antimony. For example, Japanese Patent Publication No. 53-44495 discloses the above composition. In contrast, a system using diantimony tetroxide instead of diantimony trioxide is disclosed. Although this method certainly improves the thermal stability of the final composition, diantimony tetroxide and pentoxide are generally very expensive and industrial because diantimony trioxide is used as a starting material and further steps such as oxidation and pulverization are required. There is a problem that the impact strength of the molded product is lowered due to a large particle size as compared with diantimony trioxide, poor compatibility with a resin, and the like.

[0005]

DISCLOSURE OF THE INVENTION The present invention aims to provide a flame-retardant resin composition, and more specifically, it has a particularly good fluidity and thermal stability of mechanical strength for producing a thin-walled molded article, Another object of the present invention is to provide a resin composition which is thin and has a high degree of flame retardancy that satisfies V-0 of UL-94 standard.

[0006]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that even when diantimony trioxide is used, it is combined with a flame retardant having a specific structure, and a polytetrafluoroethylene resin is further added. It was found that the above problems can be achieved by using them together, and the present invention has been completed. That is, the present invention is directed to [A] a polycarbonate resin, [B] a rubber-modified styrene resin containing a vinyl cyanide monomer as a copolymerization component, and [C] a halogen-containing high amount represented by the formula (1) (Chemical formula 3). The present invention relates to a flame-retardant resin composition comprising a molecular weight flame retardant, [D] diantimony trioxide, and [E] polytetrafluoroethylene resin.

[0007]

Embedded image (In the formula, n is an average degree of polymerization of 20 to 50, R1 and R2 are each independently hydrogen, an alkyl group, an epoxypropyl group,
Aryl groups, or halogenated versions thereof, or

[0008]

[Chemical 4] However, m is an integer of 0 to 3, the bromine content is 45 to 60% by weight with respect to the weight of the flame retardant, and the epoxy equivalent is 10,000 to 10
It is 10,000 g / mol. The polycarbonate resin used in the present invention is a product produced by reacting a dihydric phenol with a carbonate precursor by a known method such as a solution method or a melting method. Typical dihydric phenols are hydroquinone, resorcinol, 2,2-bis (4-hydroxyphenyl) propane, bis (4-hydroxyphenyl) methane, 2,2-
Bis (4-hydroxy-3,5-dimethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, 2,2-bis (4-hydroxy-3-methylphenyl) propane , Bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfone and the like. A bis (4-hydroxyphenyl) alkane system is particularly preferable, and 2,2-bis (4-hydroxyphenyl) propane, which is usually referred to as bisphenol A, is particularly preferable.

Examples of the carbonate precursor include carbonyl halide, carbonyl ester, haloformate and the like, and specific examples include phosgene, diphenyl carbonate and dihaloformate of dihydric phenol.
In producing the polycarbonate resin, addition of an appropriate molecular weight regulator, branching agent, other modifier, etc. may be carried out. Further, each of the dihydric phenol and the carbonate precursor may be used alone or in combination of two or more kinds, and the obtained polycarbonate resin may be used in combination of two or more kinds. In the present invention, a polycarbonate resin containing bisphenol A as a main raw material gives good results.

The rubber-modified styrenic resin containing the vinyl cyanide monomer used as a copolymerization component in the present invention is a styrene-based monomer and a vinyl cyanide monomer in the presence of the rubbery polymer, and is required. If present, it can be obtained by copolymerizing another monomer copolymerizable therewith by a known method such as emulsion polymerization, suspension polymerization, solution polymerization or bulk polymerization. As the rubber-like polymer, for example, a polyene, a butadiene-styrene copolymer, a diene rubber-like polymer represented by polyisoprene, or an ethylene-propylene copolymer or an ethylene-propylene-diene copolymer is represented. It is possible to use ethylene-α-olefin rubbery copolymers, acrylic rubbers mainly composed of acrylic acid esters, isobutylene-isoprene copolymers or polyurethane rubbers, among which polybutadiene and butadiene-styrene. A diene rubbery polymer such as a copolymer is preferably used.

The styrene monomer is not particularly limited,
The aromatic nucleus and vinyl carbon may be substituted with alkyl, aryl, halogen and the like. Typical examples include styrene, α-methylstyrene, p-methylstyrene, vinyltoluene, and nuclear halogen-substituted styrene. Of these, styrene and α-methylstyrene are particularly preferable. Similarly, vinyl cyanide monomer is not particularly limited,
Suitable components include acrylonitrile and methacrylonitrile. Further, examples of the monomer copolymerizable with these monomers include maleic anhydride, its derivative, and acrylic acid ester. Suitable maleic anhydride derivatives include N-substituted maleimides such as N-phenylmaleimide. Examples of suitable acrylic acid ester include methyl acrylate and methyl methacrylate. The monomers and compounds described above can be used alone or in combination of two or more. In addition, two or more kinds of the obtained copolymers may be mixed and used, and further, a copolymer of the above-mentioned monomer containing no rubbery polymer may be mixed and used. In the present invention, among the rubber-modified styrenic resins satisfying the above conditions, a resin obtained by grafting acrylonitrile and styrene onto polybutadiene, so-called ABS resin is preferably used.

The ratio of the polycarbonate resin used in the present invention and the rubber-modified styrene resin composition containing vinyl cyanide monomer as a copolymerization component is not particularly limited, but from the viewpoint of moldability. The ratio of the former is 50 to 90% by weight, and the latter is 50 to 10% by weight. In consideration of mechanical properties and heat resistance, the former is 70 to 90% by weight and the latter is 30 to 90% by weight.
A ratio of 10% by weight is particularly suitable.

The flowability of the polycarbonate resin or the rubber-modified styrene resin used in the present invention is not particularly limited, but in view of the recent tendency of the molded article to become thinner, the rubber-modified styrene resin is a high flow type. Are preferable because they can improve the fluidity of the entire composition. The moldability of the resin composition of the present invention largely depends on the fluidity of the rubber-modified styrenic resin, and is in accordance with JIS-K7210.
The melt flow index measured under the conditions of 0 ° C. and 10.0 kgf is 20 to 40 g / 10 min. Use of the range of gives good results. When the melt flow index is 20 or less, the moldability of the composition may be poor for thin wall molding applications, and when it exceeds 40, the mechanical and thermal properties of the composition may be poor, which is not preferable. On the other hand, the polycarbonate resin has a small effect of improving the fluidity of the composition even if it is a high-flow type, and rather has a large tendency to deteriorate the mechanical properties. That is, it is not preferable because it is inferior in impact strength and is easily affected by thermal degradation. Therefore, the polycarbonate resin is preferably a medium viscosity type, specifically, JIS-K721.
0, the melt flow index measured under the conditions of 280 ° C. and 2.16 kgf is 5 to 12 g / 10 min.
Those in the range of give good results. The halogen-containing high molecular weight flame retardant used in the present invention is a compound represented by the formula (1) (formula 5).

[0014]

Embedded image (In the formula, n is an average degree of polymerization of 20 to 50, R1 and R2 are each independently hydrogen, an alkyl group, an epoxypropyl group,
Aryl groups, or halogenated versions thereof, or

[0015]

[Chemical 6] However, m is an integer of 0 to 3, the bromine content is 45 to 60% by weight with respect to the weight of the flame retardant, and the epoxy equivalent is 10,000 to 10
It is 10,000 g / mol. )

The average degree of polymerization n is 20-50. When it is less than 20, impact resistance and heat resistance of the final composition may be poor, and when it exceeds 50, moldability may be poor, which is not preferable. The bromine content of the flame retardant is 45 to 60% by weight, preferably 50% by weight or more, based on the weight of the flame retardant. If it is less than 45% by weight, it may be difficult to impart sufficient flame retardancy to the final composition, which is not suitable. The epoxy equivalent is in the range of 10,000 to 100,000 g / mol, preferably 20,000 to 100,000 g / mol. Outside the range, ie less than 10,000 g / mol or 100,000 g / m
Those having an ol of more than 0 are poor in the effect of imparting the thermal stability of the final composition.

The flame retardant satisfying the above requirements is specifically obtained by reacting a brominated bisphenol A type epoxy resin having a preferable average degree of polymerization with an end capping agent under a basic catalyst such as lithium hydroxide to obtain an epoxy equivalent. Is obtained in a range suitable for the present invention. As the terminal blocking agent, halogenated arenes are preferable, and 2,4,6-tribromophenol is particularly preferable. The addition amount of the flame retardant in the present invention is not particularly limited, but it is preferably used in the range of 5 to 30 parts by weight. If it is 5 parts by weight or less, it may be difficult to impart sufficient flame retardancy, and if it exceeds 30 parts by weight, the mechanical and thermal properties of the final composition may be impaired.

The antimony trioxide used as a flame retardant aid in the present invention is a known substance. Particle size is 0.01-5
A material having a thickness of μm, more preferably 0.03 to 3 μm produces good results in terms of mechanical strength and surface appearance. The combined use of diantimony tetroxide and diantimony pentoxide is acceptable, but it is meaningless to use them in accordance with the gist of the present invention. The amount of diantimony trioxide used in the present invention is not particularly limited, but it is desirable to use it together in the range of 1/10 to 1/2 with respect to the amount of the flame retardant added. If it is 1/10 or less, it is difficult to obtain the combined effect as a flame retardant aid, and if it exceeds 1/2, not only the mechanical and thermal properties of the composition are impaired but also the thermal stability which is the gist of the present invention is sufficiently obtained. There are cases where you cannot do it.
That is, the use of 0.5 to 15 parts by weight based on the whole composition gives good results.

The polytetrafluoroethylene resin used as an anti-drip agent in the present invention is a resin having a carbon-fluorine bond in the molecule, and the content of fluorine in the resin is preferably 65 to 76% by weight. Preferably 70-
76% by weight. By microfibrillating in the composition, this retains the shape of the combustion body and acts to suppress drip. Therefore, if the fluorine content is less than 65% by weight, the crystallinity may be poor and the fibril-forming ability may be poor, which is not preferable. Further, the molecular weight is not particularly limited, but one having a large molecular weight is preferable because fibrils are easily formed, and specifically, the weight average molecular weight is 1,000,000 to
10 million are preferred. As a material satisfying these conditions, for example, a fine powder grade polytetrafluoroethylene resin for paste extrusion molding can be mentioned, which gives good results. Furthermore, the average secondary particle diameter when powdered is not particularly limited, but the average secondary particle diameter is 1 to 100.
The range of μm is more preferable because it is excellent in workability at the time of melt extrusion and the appearance of the molded product, and has little influence on the fluidity of the composition. Such a polytetrafluoroethylene resin is, for example, MPA- manufactured by Daikin Industries, Ltd.
It is easily available from the market as FA100. The addition amount of the polytetrafluoroethylene resin in the present invention is not particularly limited, but it is preferably used in the range of 0.01 to 2 parts by weight. If it is less than 0.01 part by weight, the effect of imparting the drip prevention property cannot be obtained, and if it exceeds 2 parts by weight, the fluidity of the composition is impaired.

The above-mentioned resin composition contains various elastomers, plasticizers, pigments, as long as the characteristics of the present invention are not impaired.
A stabilizer, a filler, a metal powder, a filler and the like can be appropriately used depending on the purpose and application. In particular, the addition of a phosphorus-based flame retardant such as an organic phosphate or red phosphorus is desirable in order to further improve the flame retardancy of the composition.

The method for producing the resin composition of the present invention is not particularly limited, and a generally known method can be adopted. That is, the above [A] to [E] and other necessary components are uniformly mixed with a high-speed stirrer or the like, and then melted with a uniaxial or multiaxial extruder having sufficient kneading ability, a mixing roll, a kneader, a Brabender, etc. It can be manufactured by a method such as kneading. Further, a method in which an aqueous dispersion of a polytetrafluoroethylene resin is shaken and mixed with pellets or powder of a polycarbonate resin and / or a rubber-modified styrene resin, and the mixture is kneaded and extruded after drying is particularly effective in improving the dispersion of the polytetrafluoroethylene resin. It is valid.

[0022]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Moreover, the evaluation method of the composition in the following examples was based on the following. (1) Izod impact test It was based on JIS-K7110. Here, a comparison was made between a sample formed by molding the composition in a normal molding cycle (30 seconds) and a sample molded by allowing the composition to retain heat in the injection molding machine for 10 minutes. It is judged that the composition is more deteriorated as the impact strength before and after the retention is larger (the smaller the retention rate is), and the thermal stability is inferior. The thickness of the test piece was 3.2 mm. (2) Tensile test Based on JIS-K7113. Similar to (1), a sample formed by molding the composition in a normal molding cycle (30 seconds) was compared with a sample molded by allowing the composition to retain heat in the injection molding machine for 10 minutes. The greater the decrease in tensile rupture strength and elongation before and after the retention (the smaller the retention rate), the more the composition is being degraded, and the thermal stability is judged to be poor. (3) Presence or absence of silver strips The occurrence of silver strips on the test piece due to the heat retention was visually determined. Those with silver strips are considered to have poor thermal stability. (4) Melt flow index Based on JIS-K7210. However, here, the measurement start point was set to two points at the 6th minute and the 15th minute, and changes in the melt flow index due to heat retention were observed. As the melt flow index increases (the increase rate increases), the composition is degrading and the thermal stability is judged to be poor. The measurement conditions are a load of 2.16 kgf and a temperature of 26.
It was set to 0 ° C. (5) Spiral flow flow length The flow length was measured using an Archimedes type spiral mold (flow thickness 1 mm, flow width 10 mm). The larger the obtained value, the better the moldability. The measurement conditions were a resin temperature of 260 ° C and a mold temperature of 60 ° C. (6) Flame retardance Compliant with UL-94. According to this standard, the composition having flame retardancy is V-0, V-1, V- in descending order of flame retardancy.
2, rated below. A normal composition of a polycarbonate resin containing no flame retardant and a flame retardant aid and a rubber-modified styrene resin is flammable, and the whole test piece burns out while producing many cotton ignitable drip.
-2 is not rated. The thickness of the test piece was 1.6 mm.

Production Example 300 g of brominated bisphenol A type epoxy resin,
15 g of 2,4,6-tribromophenol was reacted with 1 g of lithium hydroxide as a catalyst to prepare a halogen-containing high molecular weight flame retardant (FR-1). The average degree of polymerization and the epoxy equivalent are shown in Table 1. In addition, the average degree of polymerization and epoxy equivalent of the halogen-containing high molecular weight flame retardant were the same as those of the flame retardants FR-2 to FR-6 shown in Table 1 and brominated bisphenol A.
-Type epoxy resin and 2,4,6-tribromophenol were produced using the same method as FR-1. The average degree of polymerization n of these flame retardants was determined by gel permeation chromatography (in terms of polystyrene), and the epoxy equivalent was determined by a method according to JIS-K7236.

Examples 1 to 3 Polycarbonate resin (manufactured by Teijin Chemicals Ltd., trade name Panlite L-1250, melt flow index measured under the conditions of 280 ° C. and 2.16 kgf is 8 g / 10 m).
in. , Hereinafter "polycarbonate resin 1"), high-flow type ABS resin (manufactured by Mitsui Toatsu Chemicals, Inc., trade name Santak UT-61, melt flow index measured under the conditions of 220 ° C and 10.0 kgf is 33 g / 1.
0 min. , "ABS resin 1"), halogen-containing high molecular weight flame retardants (FR-1 to 3), diantimony trioxide (manufactured by Mitsui Toatsu Fine Co., Ltd.), and polytetrafluoroethylene resin (Daikin Industries Co., Ltd. ) Company name, MP
A-FA100) was mixed in the ratio shown in Table 2 and then thoroughly mixed with a tumbler mixer to obtain a screw diameter of 37
mm, L / D = 32 twin screw extruder, melting temperature 240
Melt extrusion was performed at a temperature of 80 ° C. and a screw rotation speed of 80 rpm to obtain a pelletized molding material composition. The composition obtained by the above method was molded into a test piece by an injection molding machine set at 260 ° C., and the physical properties of each were measured. Table 2 shows the results.

Examples 4 to 6 The polycarbonate resin and AB used in Examples 1 to 3
The S resin was changed to a grade having a different melt flow index within a suitable range and evaluated in the same manner (the polycarbonate resin used was manufactured by Teijin Chemicals Ltd. under the trade name of Panlite L-1225, 280 ° C · 2.16 kgf). Melt flow index measured under the conditions of 10g / 10mi
n. , Hereinafter "Polycarbonate resin 2", AB used
S resin is manufactured by Mitsui Toatsu Chemicals, Inc., trade name Santak GT-12, melt flow index measured under the conditions of 220 ° C. and 10.0 kgf is 30 g / 10 mi.
n. , "ABS resin 2"). Table 2 shows the results.

Comparative Examples 1 to 3 Tests were carried out in the same manner as in Examples 1 to 3, but the flame retardant used here had a molecular weight and / or epoxy equivalent which are not suitable in the present invention (FR-4 to 6). ). The results are shown in Table 3.

Comparative Examples 4 to 5 Tests were carried out in the same manner as in Examples 1 to 3, but the flame retardant used here was decabromodiphenyl ether (manufactured by Mitsui Toatsu Fine Co., Ltd., trade name DB-102, in the table). "Decabro" and a carbonate oligomer of tetrabromobisphenol A (Teijin Kasei Co., Ltd., trade name F
G-8500, abbreviated as "TBA carbonate" in the table). The results are shown in Table 3.

Comparative Examples 6 to 7 The flame retardant aids used in Comparative Example 5 were diantimony pentoxide (manufactured by Nissan Chemical Co., Ltd., trade name NA-1030) and diantimony tetroxide (Nissan Chemical Co., Ltd.). Made, product name NA-
5050) and evaluated in the same manner. The results are shown in Table 4.

Comparative Example 8 The flame-retardant auxiliary agent used in Comparative Example 5 was previously prepared with methyltriethoxysilane (manufactured by Daihachi Chemical Co., Ltd., trade name MTS).
-32) and diantimony trioxide that has been surface treated,
It evaluated similarly. The results are shown in Table 4.

Comparative Example 9 Comparative Example 9 is an example in which the polytetrafluoroethylene resin was not used in Examples 1 to 3. The results are shown in Table 4.

Comparative Example 10 A composition consisting of a polycarbonate resin and an ABS resin alone, containing no flame retardant, flame retardant aid, polytetrafluoroethylene resin, etc. was evaluated in the same manner as in Examples 1-3. The results are shown in Table 4.

[0032]

[Table 1]

[0033]

[Table 2]

[0034]

[Table 3]

[0035]

[Table 4]

[0036]

EFFECTS OF THE INVENTION The flame-retardant resin composition of the present invention is capable of imparting a high degree of flame retardancy with a thin wall while maintaining the balance between fluidity and mechanical strength and their thermal stability. It is extremely useful in various fields such as various mechanical parts and electric parts, especially home electric appliances and molding materials for OA equipment, in which molded products are required to be thin.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display area C08L 27:18 63:02)

Claims (5)

[Claims] 1. A polycarbonate resin [A], [B] a rubber-modified styrene resin containing a vinyl cyanide monomer as a copolymerization component, and [C] a high halogen-containing compound represented by the formula (1) Molecular weight flame retardant, [D] diantimony trioxide,
Flame-retardant resin composition comprising [E] polytetrafluoroethylene resin (In the formula, n is an average degree of polymerization of 20 to 50, R1 and R2 are each independently hydrogen, an alkyl group, an epoxypropyl group,
Aryl groups, or brominated forms of these, or However, m is an integer of 0 to 3, the bromine content is 45 to 60% by weight with respect to the weight of the flame retardant, and the epoxy equivalent is 10,000 to 1
It is 0,000 g / mol. ) 2. A polycarbonate resin [A] having a melt flow index of 5 to 12 g / 10 min. Is,
The resin composition according to claim 1. 3. A rubber-modified styrenic resin containing [B] a vinyl cyanide monomer as a copolymerization component has a melt flow index of 20 to 40 g / 10 min. The resin composition according to claim 1, which is 4. The resin composition according to claim 1, wherein the polytetrafluoroethylene resin [E] has a weight average molecular weight of 1 to 10,000,000 and an average secondary particle diameter of 1 to 100 μm. 5. A polycarbonate resin [A] is 50-9.
The composition is represented by the formula (1) (formula 1) based on 100 parts by weight of a composition containing 0 to 10% by weight of a rubber-modified styrene resin containing vinyl cyanide monomer [B] as a copolymer component. 5 to 30 parts by weight of [C] halogen-containing high molecular weight flame retardant, and 0.5 to 15 parts by weight of [D] diantimony trioxide,
[E] polytetrafluoroethylene resin 0.01-2
The resin composition according to claim 1, which is blended by weight.