KR0144382B1 - Inflammable thermoplastic resin composition - Google Patents

Abstract

The thermoplastic resin composition of the present invention comprises (A) 80 to 96% by weight of a thermoplastic polycarbonate resin containing no halogen (a ₁ ); And (a ₂ ) a resin obtained by graft copolymerization of methyl methacrylate, butyl acrylate and styrene in 30 to 50 wt% in 50 to 70 wt% of butadiene rubber, wherein methyl methacrylate is 30 to 50 in the grafted composition. % By weight, butyl acrylate is 0 to 15% by weight, and styrene is 40 to 60% by weight, and the graft ratio is 40% or more by 100 parts by weight of the base resin consisting of 20 to 4% by weight of the styrene-containing graft copolymer resin It is a resin composition which mixed 5-20 weight part phosphorus flame retardant (B) and 0.1-2.0 weight part fluororesin (B) aryl phosphate oligomer.

Description

Thermoplastic resin composition having flame retardancy

1 is a transmission electron microscope (TEM) photograph of a resin composition according to Example 1 of the present invention.

2 is a transmission electron micrograph of a resin composition according to Example 2 of the present invention.

3 is a transmission electron micrograph of a resin composition according to Comparative Example 1 of the present invention.

4 is a transmission electron micrograph of a resin composition according to Comparative Example 2 of the present invention.

5 is a transmission electron micrograph of a resin composition according to Comparative Example 3 of the present invention.

6 is a transmission electron micrograph of a resin composition according to Comparative Example 4 of the present invention.

[Field of Invention]

The present invention relates to a thermoplastic resin composition having flame retardancy.

More specifically, the present invention relates to a thermoplastic resin composition having a flame retardancy composed of a base resin composed of a halogen-free thermoplastic polycarbonate resin and a styrene-containing copolymer resin, an aryl phosphate oligomer as a phosphorus flame retardant, and a fluoro resin. .

The thermoplastic resin composition of the present invention may be added in the required amount of inorganic additives, heat stabilizers, antioxidants, dyes, and / or pigments depending on the respective use of the resin composition.

[Background of invention]

Polycarbonate resins are excellent in transparency, impact resistance, and heat resistance, and are used in many applications such as electric and electronic products and automobile parts. However, polycarbonate resins are used in combination with other resins because of poor processability. For example, a mixture of a polycarbonate resin and a styrene resin is a resin mixture having high notch impact strength and improving workability.

Another essential requirement for the resin composition is that the resin must be flame retardant. Many studies have been conducted to impart flame retardancy to the resin composition, and among them, a method of melt-mixing a halogen compound and an antimony compound to a polycarbonate resin has been used to impart flame retardance to the resin composition. In addition, U.S. Patent Nos. 4,983,658 and 4,883,835 disclose halogen resins and phosphate ester-based compounds as flame retardants in polycarbonate resins, and disclose resin compositions in which polytetrafluoroethylene emulsion is mixed with graft ABS resins to impart flame retardancy. Doing. However, these halogen compounds exhibit sufficient flame retardant functions in the event of a fire. However, decomposition gases are generated during resin processing to cause corrosion in the mold. When using a brominated diphenyl ether bromine compound, dioxins or difuran may be used. Toxic gases are likely to occur that can cause fatal harm to the same body. US Pat. No. 4,692,488 also discloses a resin composition comprising a halogen-free polycarbonate, a halogen-free copolymer of styrene and (meth) acrylonitrile, a halogen-free phosphorus compound, a tetrafluoroethylene polymer, and an additive. And US Pat. No. 5,204,394 discloses resin compositions consisting of aromatic polycarbonates, styrene-containing copolymers and / or styrene-containing graft copolymers, and mixtures of phosphate oligomers or phosphate oligomers as flame retardants. Phosphorus compounds used in the US patents include triaryl phosphate and condensed phosphate esters. When triaryl phosphate is used in a polycarbonate resin, vaporized flame retardants are likely to form a layer at the sites of high stress during processing to cause juicing. In addition, the use of triaryl phosphate has a problem of lowering the heat resistance of the polycarbonate resin. When aryl phosphate oligomers, which are condensed phosphate esters, are used in polycarbonate resins, the juice does not occur, but there is a disadvantage in that flame retardancy is reduced when the same content is used than in the case of using monomolecular aryl phosphate.

In the above-mentioned US patent, a polycarbonate resin and a SAN (styrene / acrylonitrile) copolymer resin are used as the base resin, and a resin obtained by melt-mixing a graft-acrylonitrile / butadiene / styrene (ABS) resin is used. However, these basic resins were found to cause agglomeration of the grafted rubber particles in the SAN phase according to the processing conditions. In other words, depending on the processing conditions of the resin, g-ABS resin is highly likely to aggregate mainly in the non-grafted SAN resin having a better compatibility, and since the SAN resin has no compatibility with the polycarbonate resin, Occurs. Therefore, the grafted rubber particles are not evenly distributed throughout the resin, and the phenomenon is concentrated in a SAN resin having a better affinity. The phenomenon in which the grafted rubber particles are collected on the SAN becomes a factor that causes severe physical property deviation of the resin. In particular, this phenomenon is judged to be due to the difference in the affinity of the resins mixed with the thermal history by injection when injecting a polycarbonate-based resin composition with sufficient kneading during extrusion.

In order to solve the above problems, the inventors of the present invention in the Republic of Korea Patent Application No. 95-4542 (US Patent Application No. 08 / 449,521) thermoplastic polycarbonate resin (a ₁ ) and styrene-containing graft copolymer resin (a ₂ ) The thermoplastic resin composition which consists of a phosphorus flame retardant (B) and a fluororesin (C) to the base resin (A) which consists of these is disclosed.

The present invention, in the resin composition of Korean Patent Application No. 95-4542, by deforming the styrene-containing graft copolymer resin (a ₂ ) constituting the base resin (A) without the occurrence of juice phenomenon and according to the processing conditions It relates to a flame-retardant resin composition that does not generate a deviation of the excellent excellent workability and strength of the Weld Line.

[Purpose of invention]

An object of the present invention is to use an aryl phosphate oligomer and fluoro resin in the base resin consisting of polycarbonate and styrene-containing graft copolymer resin, without the occurrence of the juice phenomenon and good workability, the physical property deviation during processing It is to provide a thermoplastic resin composition having a flame retardancy that does not.

Another object of the present invention is to provide a flame retardant thermoplastic resin composition in which particles of the resin are evenly distributed by using an aryl phosphate oligomer and a fluororesin in a base resin composed of a polycarbonate and a styrene-containing graft copolymer resin. .

Still another object of the present invention is to provide a flame retardant thermoplastic resin composition having excellent fusion line strength.

[Summary of invention]

The thermoplastic resin composition of the present invention comprises (A) 80 to 96% by weight of a thermoplastic polycarbonate resin containing no halogen (a ₁ ); And (a ₂ ) a resin obtained by graft copolymerization of methyl methacrylate, butyl acrylate and styrene in 30 to 50 wt% in 50 to 70 wt% of butadiene rubber, wherein methyl methacrylate is 30 to 50 in the grafted composition. % By weight, butyl acrylate is 0 to 15% by weight, and styrene is 40 to 60% by weight, and the graft ratio is 40% or more by 100 parts by weight of the base resin consisting of 20 to 4% by weight of the styrene-containing graft copolymer resin It is a resin composition which mixed 5-20 weight part phosphorus flame retardant (B) and 0.1-2.0 weight part fluororesin (B) aryl phosphate oligomer.

In the resin composition of the present invention, an inorganic additive, a heat stabilizer, a light stabilizer, a pigment, and / or a dye may be added according to each use.

Detailed Description of the Invention

The thermoplastic resin composition having flame retardancy of the present invention comprises a base resin composed of (A) polycarbonate and a styrene-containing graft copolymer resin, (B) phosphorus-based flame retardant, and (C) fluorine-based resin. Description of each of these components is as follows.

(A) Basic resin

The base resin is a resin blend of polycarbonate and styrene-containing graft copolymer resin. Polycarbonate resin is used at 80 to 96% by weight, and styrene-containing graft copolymer resin is used at 20 to 4% by weight.

Polycarbonate resins include aromatic polycarbonates, aliphatic polycarbonates, and aromatic aliphatic polycarbonates depending on the type of substituents, and these may be used alone or in the form of a mixture. An aromatic polycarbonate is preferable, and the polycarbonate whose bisphenol A is a structural unit is especially preferable.

The styrene-containing graft copolymer resin used in admixture with the polycarbonate resin is a resin obtained by graft copolymerization of methyl methacrylate, butyl acrylate and styrene in 30 to 50% by weight to 50 to 70% by weight of butadiene rubber. In the grafted composition, the methyl methacrylate is 30 to 50% by weight, the butyl acrylate is 0 to 15% by weight, and the styrene is 40 to 60% by weight, and the graft ratio is 40% or more and is insoluble in acetone. It is preferable that the content is 90 to 100% by weight. In particular, the polymerized SAN copolymer resin is not added to the base resin of the resin composition of the present invention.

The polycarbonate resin is used at 80 to 96% by weight based on the entire base resin of the present invention, and the styrene-containing graft copolymer resin is used at 20 to 4% by weight based on the entire base resin. When the polycarbonate resin is 80% by weight or less, the flame retardancy is lowered. When the polycarbonate resin is 96% by weight or more, the styrene-containing graft copolymer resin does not exhibit sufficient impact reinforcing effect on the polycarbonate resin.

Although the styrene-containing graft copolymer resin can be prepared by a conventional polymerization method, there is an emulsion polymerization method that can be most suitably used in the present invention.

(B) phosphorus flame retardant

The phosphorus flame retardant used in the present invention is an arylphosphate oligomer. The aryl phosphate oligomer is represented by the following general formula (I).

Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ are each independently a halogen-free C ₆ -C ₂₀ aryl group or alkyl-substituted group, and n is in the range of 0 to 5.

In the formula, n represents the degree of synthesis of the flame retardant, and the average value of n of the phosphorus-based flame retardant of the general formula (I) used in the present invention is 0.3 to 0.8. In the above formula, when n is 0, the compound is a conventional monomolecular phosphorus flame retardant, and when n is larger than 0, the compound is an oligomeric phosphorus flame retardant. That is, the phosphorus-based flame retardant is usually present in the form of a mixture in which n has a value from 0 to 5, wherein a compound having an average value of 0.3 to 0.8 can be used in the present invention.

Examples of the compound corresponding to the case where n is 0 in the general formula (I) include triphenyl phosphate, tri (2,6-dimethylphenyl) phosphate, tri (4-methylphenyl) phosphate, tricresylphosphate, diphenyl 2 -Ethylcresyl phosphate, diphenylcresyl phosphate, tri (isopropylphenyl) phosphate, trigylenyl phosphate, and gyrenyl diphenyl phosphate. However, the above-listed compounds corresponding to the general formula (I) may not all be used for the purpose of the present invention. Since the monomolecular phosphorus flame retardant when n is 0 and the phosphorus flame retardant having n less than 0.3 have a good volatilization property at a high temperature of 200 ° C. or higher, volatilized flame retardants are laminated during processing such as injection to generate juice. It has a drawback. Therefore, the monomolecular phosphorus flame retardant whose n is 0 and the phosphorus flame retardant whose n is less than 0.3 are not preferable in a flame retardant resin composition. In addition, when n is 1.0 or more, the juice phenomenon is remarkably reduced, but the flame retardancy is lowered than when using a monomolecular phosphorus flame retardant when n is less than 0.3, which adversely affects the even distribution of grafted rubber particles in the resin. Physical properties, in particular impact strength, are lowered. Therefore, the phosphorus-based flame retardant used in the present invention preferably has an average value of n to 0.3 to 0.8 in the general formula (I).

It is preferable to use an aryl phosphate oligomer in the range of 5-20 weight part with respect to 100 weight part of base resins of this invention.

(c) fluoro resins

Fluoro-based resins are conventionally available resins such as polytetrafluoroethylene, polyvinylidene fluoride, copolymers of tetrafluoroethylene and vinylidene fluoride, copolymers of tetrafluoroethylene and fluoroalkyl vinyl ether, And copolymers of tetrafluoroethylene and hexafluoropropylene. These may be used independently of each other, or a mixture of two or more different types may be used. In order to prevent dripping during combustion, fluoro resins form a fibrillar network in the resin when mixed and extruded together with the resin to lower the flow viscosity and increase the shrinkage rate of the resin during combustion. Prevent dropping of When the fluororesin in an emulsion state is used, the dispersibility of the fluororesin is good with respect to the entire resin, but the process is complicated. Therefore, even if it is a powder state, it can use preferably if it can form a fibrous net by disperse | distributing suitably to all resin. Fluoro-based resins that can be preferably used in the present invention include polytetrafluoroethylene. Polytetrafluoroethylene having a particle size of 20 to 500 microns is suitable for mixing. The usage-amount of a fluororesin is 0.1-2.0 weight part with respect to 100 weight part of base resins.

The thermoplastic resin composition of the present invention may be added with an inorganic additive, a heat stabilizer, an antioxidant, a light stabilizer, a pigment, and / or a dye according to each use. The inorganic additives to be added include asbestos, glass fibers, talc, and ceramics, which can be used in the range of 0 to 30 parts by weight based on 100 parts by weight of the base resin.

The thermoplastic resin composition of the present invention is a triaryl phosphate such as triphenylphosphate, tri (2,6-dimethylphenyl) phosphate or tri (4-methylphenyl) phosphate in a base resin composed of polycarbonate and styrene-containing graft copolymer resin. By using a mixture of either and an aryl phosphate oligomer as a flame retardant and containing a fluororesin, generation of toxic gas, which is a problem when using a conventional halogen compound as a flame retardant, can be prevented, and only conventional triaryl phosphate is flame retardant. It is possible to prevent surface condition defects such as juice phenomenon and deterioration of heat resistance, which is a problem when used in the process. Can significantly improve surface discoloration problems, The thermoplastic resin composition of the present invention, in which the grafted rubber particles may be uniformly distributed throughout the resin to provide uniform physical properties, and provide excellent fusion line strength, the thermoplastic resin composition of the present invention is a polycarbonate resin and a styrene-containing graft copolymer resin. In the base resin consisting of a mixture of one of the phosphorus compounds such as triphenyl phosphate, triphosphate, tri [2,6-dimethylphenyl] phosphate or tri [4-methylphenyl] phosphate and aryl phosphate oligomer as a flame retardant, The system resins are mixed and the necessary inorganic additives, heat stabilizers, antioxidants, light stabilizers, pigments, and / or dyes are added and mixed in a conventional mixer. This mixture is again prepared into pellet resin composition through an extruder.

The invention is better understood by the following examples, which are intended for the purpose of illustration of the invention and are not intended to limit the scope of protection defined by the appended claims.

EXAMPLE

(A ₁ ) polycarbonate resin, (a ₂ ) styrene-containing graft copolymer resin, which is each component of (A) base resin used in Examples 1 to 2 and Comparative Examples 1 to 4 below, (B ) Production and specifications of phosphorus flame retardant and (C) fluororesin are as follows.

(A) Basic resin

(a ₁ ) Polycarbonate resin: L-1225L Grade of TEIJIN, Japan was used.

(a ₂ ) Styrene-containing graft copolymer resin: Butadiene rubber latex is added so that the butadiene-containing content is 65% by weight based on the entire monomer, and deionized water, cumene hydroperoxide and mercaptan-based chain transfer agent are added to make the interior 70 Keep at ℃. Styrene-containing graft copolymer latex was prepared by dropping 17% by weight of styrene, 14% by weight of methyl methacrylate and 4% by weight of butyl acrylate for 4 hours. At this time, the appropriate amount of divinylbenzene is dripped together. The latex was solidified in a 1.5% magnesium sulfate solution and dried to prepare a powdered styrene-containing graft copolymer resin.

(a ₃ ) Graft-ABS copolymer resin: 1.0 part by weight of potassium oleate, which is an additive necessary for a mixture of 50 parts by weight of butadiene rubber latex of solid content, 36 parts by weight of styrene, 14 parts by weight of acrylonitrile, and 150 parts by weight of deionized water, 0.4 parts by weight of cumene hydroperoxide and 0.3 parts by weight of mercaptan-based chain transfer agent were added and maintained at 75 ° C. for 5 hours to complete the reaction, thereby preparing graft-ABS latex. 0.4 parts by weight of sulfuric acid was added to the resulting resin composition and solidified to prepare a graft-ABS graft copolymer in powder form.

(a ₄ ) SAN copolymer resin: Suspended by adding 0.2 parts by weight of azobisisobutyronitrile and 0.5 parts by weight of tricalcium phosphate as additives necessary for a mixture of 70 parts by weight of styrene, 30 parts by weight of acrylonitrile and 120 parts by weight of deionized water. The polymerization was performed to prepare a SAN copolymer resin. The copolymer was washed with water, dehydrated and dried to obtain a powdery SAN copolymer resin.

(B) phosphorus flame retardant

Triphenyl phosphate (when n is 0 in the said general formula (I)): Triphenyl phosphate (TPP) by Daihachi, Japan was used.

Aryl phosphate oligomer (when n is 1.4 in the general formula (I)): CR-733S manufactured by Daihachi, Japan was used.

Arylphosphate oligomer (when n is 0.6 in Formula (I)): 114.7 g of phenol, 220 g of resorcinol, and 0.2 g of dichloromagnesium were mixed with 100 ml of benzene, heated to 70 ° C., and then heated at this temperature for 2 hours. 82.8 g of trichlorophosphine oxide were added dropwise over time. After completion of the reaction, the mixture was stirred at a temperature of 120 ° C. for 3 hours and maintained until no more hydrogen chloride gas was generated. The solvent and impurities were removed to exist in a liquid state at room temperature, and the freezing point was -10 ° C. or less. In I), an arylphosphate oligomer having n value of 0.6 was prepared.

(C) fluoro resin

Teflon 7AJ from Dupont, USA was used.

[Examples 1-2 and Comparative Examples 1-4]

The composition of each component used in Examples 1-2 and Comparative Examples 1-6 is shown in Table 1. Examples 1 to 2 are examples according to the resin composition of the present invention. Comparative Examples 1-4 are the Example which manufactured the resin composition, changing the base resin or phosphorus flame retardant.

In Examples 1 to 3 and Comparative Examples 1 to 4, each component was mixed and extruded to prepare a resin composition in a pellet state. Each prepared pellet resin composition was injected under the injection temperature shown in Table 1 to prepare a test piece.

Flame retardancy, heat resistance, fusion line strength and impact strength of the test pieces of the resin composition prepared according to Examples 1 to 2 and Comparative Examples 1 to 4 were measured, and the judging phenomenon and the grafting of the grafted rubber particles were observed. It was. Agglomeration of the grafted rubber particles was observed by photographing the specimens according to Examples 1 to 2 and Comparative Examples 1 to 4 with a transmission electron microscope (TEM). This TEM picture is a 5000 magnification. TEM photographs of the specimens according to Examples 1 to 2 were evenly distributed without agglomeration of the grafted rubber particles. However, TEM photographs of the specimens according to Comparative Examples 1 to 4 show that the grafted rubber particles are not always evenly distributed according to the injection temperature conditions. In Comparative Examples 1 and 2, the grafted rubber particles agglomerate on the SAN. However, in Comparative Example 3, the grafted rubber particles do not aggregate and show an even distribution. In Comparative Example 4, the rubber particles are somewhat aggregated. This is presumed to be different depending on the composition of the resin composition and the injection operation conditions. The results are shown in Table 2.

(1) Flame retardant: Measured according to UL 94 VB.

(2) Impact strength: measured according to ASTM D256.

(3) Fusion line strength: The impact strength is measured after notching the fusion line.

(4) Heat resistance: Measured based on ASTM D306.

(5) Juicing phenomenon: After injection, the result was observed by an optical microscope after holding for 24 hours in an oven at 80 ° C. (×: no juice phenomenon occurred ○: a juice phenomenon occurred).

(6) Agglomeration of grafted rubber particles Processability: The agglomeration of grafted rubber particles was observed by TEM photographs (photographs were taken of samples having a thickness of 1/4). Agglomeration occurs)

Claims (3)

(A) (a ₁ ) 80 to 96% by weight of a thermoplastic polycarbonate resin containing no halogen; And (a ₂ ) a resin obtained by graft copolymerization of methyl methacrylate, butyl acrylate and styrene in 30 to 50 wt% in 50 to 70 wt% of butadiene rubber, wherein methyl methacrylate is 30 to 50 in the grafted composition. 20% to 4% by weight of styrene-containing graft copolymer resin having 0% to 15% by weight of butyl acrylate and 40% to 60% by weight of styrene and having a graft ratio of 40% or more; 100 parts by weight of a base resin; (B) 5 to 20 parts by weight of an arylphosphate oligomer having the following general formula with respect to 100 parts by weight of the base resin and having an average value of n in a range of 0.3 to 0.8; And Wherein R ¹ , R ² , R ³ , R ⁴ and R ⁵ independently of each other are C ₆ -C ₂₀ aryl groups or alkyl-substituted groups containing no halogen. (C) 0.1 to 2.0 parts by weight of fluororesin based on 100 parts by weight of the base resin; A thermoplastic resin composition having flame retardance, characterized in that consisting of. The method of claim 1, wherein the fluororesin (C) is polytetrafluoroethylene, polyvinylidene fluoride, a copolymer of tetrafluoroethylene and vinylidene fluoride, tetrafluoroethylene and fluoroalkyl vinyl ether At least one selected from the group consisting of a copolymer and a copolymer of tetrafluoroethylene and hexafluoropropylene, wherein the thermoplastic resin composition has flame retardancy. The thermoplastic resin composition of claim 1, wherein the resin composition further comprises an inorganic additive, a heat stabilizer, an antioxidant, a light stabilizer, a pigment, and / or a dye.