KR20020094345A - Flame retardant polymer resin composition having improved heat distortion temperature and impact strength properties - Google Patents

Abstract

PURPOSE: A flame retardant polymer resin composition is provided, to improve the thermal deformation temperature and the impact strength by using a mixture of a phosphazene compound and a phosphoric ester mixed by a specific ratio. CONSTITUTION: The polymer resin composition comprises 100 parts by weight of a base resin composition consisting of 40-95 wt% of a thermoplastic polycarbonate resin containing no halogen, 4-50 wt% of a rubber-modified styrene-containing graft copolymer resin containing no halogen, and 1-30 wt% of a styrene-containing copolymer containing no halogen; 1-20 parts by weight of a phosphazene compound and a phosphoric ester compound; 0.05-2.0 parts by weight of a fluorinated polyolefin-based resin; and optionally 0.01-2.0 parts by weight of aluminum hydroxide or antimony trioxide. The mass ratio of the phosphazene compound and the phosphoric ester compound is 85:15 to 15:85.

Description

Flame retardant polymer resin composition having improved heat distortion temperature and impact strength properties

The present invention relates to a flame retardant polymer resin composition having improved heat distortion temperature and impact strength characteristics.

Typically, blends of Polycarbonate (PC) and Acrylonitrile-Butadiene-Styrene (ABS) (PC / ABS) have excellent impact resistance and are therefore suitable for use in consumer electronics housings or in automotive interiors. It is often used for decoration. Therefore, flame retardancy has been required for safety in the event of a fire, and thus PC / ABS having flame retardancy has been developed.

Initially, halogen-containing flame retardants were mainly used as flame retardants of PC / ABS. However, flame retardant PC / ABS using a halogen-containing flame retardant has a problem in that toxic gases are generated during combustion. Therefore, development of a flame retardant without using halogen has been required.

Halogen-free flame retardants are termed non-halogen flame retardants, and the most widely used non-halogen flame retardants are phosphorus-based flame retardants containing phosphorus. However, in the case of the phosphorus-based flame retardant, since the flame retardancy is greatly inferior to that of the halogen-containing flame retardant, a large amount of the phosphorus-based flame retardant must be used to obtain excellent flame retardancy, which causes a disadvantage in that the physical properties of the resin composition are lowered.

U.S. Patents 5,030,675 and 5,061,745 describe flame retardant resin compositions consisting of polycarbonate resins, rubber modified styrene containing graft copolymers, styrene containing copolymers, phosphate ester monomers and fluorinated polyolefinic resins. However, this composition exhibits a marked decrease in heat resistance due to the use of phosphate ester monomers as flame retardants.

U.S. Patent No. 5,204,394 uses oligomeric phosphate esters, in particular resorcinol diphenyl phosphate esters, as flame retardants in polycarbonate resins, styrene-containing copolymers and styrene-containing copolymers in order to reduce the heat resistance decrease caused by phosphate ester monomers. It was. This resin composition exhibits higher thermal stability and improved mechanical properties than the conventional flame retardant resin composition using triphenylphosphate as a phosphorus flame retardant, but is less than the physical properties of halogen flame retardant PC / ABS. Heat resistance is only slightly higher than that.

The present invention is to solve the above problems, it is an object to provide a flame retardant polycarbonate-based thermoplastic resin composition excellent in heat resistance and impact strength properties by mixing a phosphazene flame retardant and phosphate ester flame retardant in a specific ratio.

The present invention relates to a flame retardant polymer resin composition having improved heat distortion temperature and impact strength characteristics, comprising: (A) halogen-free thermoplastic polycarbonate resin 40-95 wt%, (B) halogen-free rubber modified styrene (D) phosphazene compound and (E) phosphoric acid based on 100 parts by weight of the base resin composition consisting of 4 to 50% by weight of graft copolymer resin and 1 to 30% by weight of (C) halogen-free styrene-containing copolymer It consists of 1-20 weight part of ester compounds, and 0.05-2.0 weight part of (F) fluorinated polyolefin resin, and a component (D) :( E) is 85: 15-15: 85, It is characterized by the above-mentioned.

In addition, the flame-retardant polymer resin composition of the present invention may be made by further comprising 0.01 to 2.0 parts by weight of aluminum hydroxide and antimony trioxide based on 100 parts by weight of the base resin composition as a flame retardant aid.

Referring to each component constituting the composition of the present invention in detail as follows.

(A) polycarbonate resin

An aromatic polycarbonate is a polymer containing the unit of following General formula (1).

In the above formula (1), A is a divalent aromatic radical derived from the dihydric phenol used in the preparation of the polymer. As a bivalent phenolic compound used for aromatic polycarbonate manufacture, bisphenol is preferable and bisphenol A is more preferable specifically ,.

Polycarbonate is prepared by reacting the divalent phenolic compound with phosgene on an interface or in a uniform phase. Polycarbonates having a specific molecular weight can be obtained by controlling the amount of monophenols such as phenol, paracresol and paraisooctyl phenol using a chain terminator.

The polycarbonate resin (A) of the present invention has a viscosity average molecular weight (Mv) of 10,000 to 50,000, preferably 15,000 to 30,000. Meanwhile, the polycarbonate may be a homopolymer or a copolymer of a dihydric phenol compound.

The polycarbonate resin (A) of the present invention constitutes a base resin together with the rubber modified styrene-containing graft copolymer (B) and the styrene-containing copolymer (C).

Polycarbonate is preferably used in the range of 40 to 95% by weight of the total base resin.

(B) Rubber Modified Styrene-Containing Graft Copolymer

Rubber-modified styrene-containing graft copolymer resin used in the present invention is one of styrene, α-methyl styrene, nuclear substituted styrene, methyl methacrylate or 30 to 65% by weight of a mixture thereof and acrylonitrile, methacrylonitrile Or a mixture of methyl methacrylate, butyl acrylate, maleic anhydride, N-substituted maleimide, or a mixture thereof with 10 to 30% by weight of butadiene rubber, acrylic rubber, ethylene / propylene rubber having a glass transition temperature of -10 ° C or less. , Styrene / butadiene rubber, acrylonitrile / butadiene rubber, butadiene / styrene rubber, polyisoprene, ethylene-propylene-diene monomer terpolymer (EPDM), polyorganosiloxane and polyalkyl (meth) acrylate composite rubber, or It is a copolymer grafted to 5 to 60 weight% of these mixtures.

The graft copolymer resin may be prepared by a conventional polymerization method, but is preferably synthesized by emulsion polymerization and bulk polymerization. Acrylonitrile-butadiene-styrene (ABS) resins obtained by grafting acrylonitrile and styrene on butadiene rubber are most widely used.

When preparing the graft copolymer, the average size of the rubber particles is preferably in the range of 0.05 to 4 μm in consideration of impact strength and appearance.

The rubber-modified styrene-containing graft copolymer is preferably used in an amount of 4 to 50% by weight in the total base resin.

(C) styrene-containing copolymer

The styrenic-containing copolymer used in the present invention is 50 to 80% by weight of at least one of styrene, α-methylstyrene and nuclear substituted styrene, acrylonitrile, methyl methacrylate, butyl acrylate, maleic hydride and N At least one of the substituted maleimides consists of 20-50% by weight. As the styrene-containing copolymer resin, one produced by a conventional polymerization method can be used, and in particular, one synthesized by suspension polymerization or bulk polymerization is preferable.

The styrene-containing copolymer is preferably used in an amount of 1 to 30% by weight in the entire base resin.

(D) phosphazene compounds

The phosphazene compound used for this invention is represented by following General formula (2).

In Formula (2), n is an integer of 3 to 25 when the phosphazene compound is a cyclic compound, and an integer of 3 to 1000 when the phosphazene compound is a cyclic compound.

R ¹ and R ² are each represented by the formula (3).

R <^3> , R <^4> is a hydrogen atom or a C1-C4 alkyl group.

(E) Phosphate Ester Compound

The phosphate ester compound used in the present invention is preferably resorcinol diphenyl phosphate (RDP), and is represented by the following general formula (4).

In the formula (4), Ar ¹ ~ Ar ⁴ is one selected from the group consisting of cresyl, phenyl, styrene, propylphenyl, butylphenyl, R is arylene, n is 0-5.

In the present invention, the effect is greater when the average value of n is 0.5 to 1.5.

On the other hand, when Ar ¹ to Ar ⁴ are each phenyl, and R is phenylene, it is particularly preferable when R is 1,3-phenylene.

Most preferably Ar ¹ to Ar ⁴ are each phenyl, and R is as shown in Formula (5).

In the present invention, two or more compounds substituted as described above may be used in combination.

The phosphazene compound and the phosphate ester compound are preferably used in an amount of 1 to 20 parts by weight based on 100 parts by weight of the total base resin composition.

(F) fluorinated polyolefin resin

Fluorinated polyolefin resins used in the present invention are conventionally available resins such as polytetrafluoroethylene, polyvinylidene fluoride, copolymers of tetrafluoroethylene and vinylidene fluoride, and tetrafluoroethylene and hexafluoro There is a copolymer of propylene. These may be used independently from each other, or a mixture of two or more different from each other may be used.

The fluorinated polyolefin resin which can be preferably used in the present invention is polytetrafluoroethylene. Polytetrafluoroethylene having a particle size of 0.05 to 1000 µm is suitable for mixing.

The amount of fluorinated polyolefin resin used is 0.05 to 2.0 parts by weight based on 100 parts by weight of the base resin composition.

(G) aluminum hydroxide and antimony trioxide

In the present invention, since aluminum hydroxide and antimony trioxide are used as flame retardant aids, the flame retardancy is improved while lowering the content of the phosphazene / phosphate ester flame retardant.

Aluminum hydroxide and antimony trioxide may be used in 0.01 to 2.0 parts by weight based on 100 parts by weight of the base resin composition.

The flame retardant polymer resin composition of the present invention is mixed in a conventional mixer after addition of an inorganic additive, a heat stabilizer, an antioxidant, a light stabilizer, a pigment or a dye according to each use.

Hereinafter, exemplary embodiments of the present invention will be described in detail, but the present invention is not limited thereto.

Example

The specification of the composition used in the Example and the comparison is as follows.

(A) Polycarbonate resin: Bisphenol A type polycarbonate having a viscosity average molecular weight (Mv) of 15,000 to 30,000

(B) Rubber modified styrene-containing graft copolymer (g-ABS): 45 wt% discontinuous polybutadiene rubber phase and 55 wt% solid styrene-acrylonitrile thermoplastic phase (72 wt% styrene and 28 wt% Emulsion-acrylonitrile-butadiene-styrene graft copolymers including copolymers of acrylonitrile)

(C) Styrene-containing copolymer: copolymer of 75% by weight of styrene and 25% by weight of acrylonitrile

(D) phosphazene compound: commercially available SPS-100 from Otsuka Chemical

(E) Phosphate Ester Compounds: Commercially Available RDP

(F) Fluorinated polyolefin resin: polytetrafluoroethylene having an average particle size of 30 to 500 µm

(G) Aluminum hydroxide and antimony trioxide: use of commercially available products

Each component shown in Table 1 was mixed, and the antioxidant and the heat stabilizer were added, mixed in a conventional mixer, and then introduced into a twin screw extruder having L / D 40 and Φ = 25 mm. The mixture was prepared into a resin composition in pellet form through an extruder.

The specimens were prepared at an injection temperature of 230 ° C., and then left at 23 ° C. and a relative humidity of 50% for 40 hours.

Heat resistance: The heat deflection temperature was measured in a conventional manner at 18.6 kgf / cm 2 on 0.25 inch thick specimens in accordance with ASTM D648.

Impact Strength: According to ASTM D256, the notched Izod impact strength of the specimen with a thickness of 0.125 inch was measured in a conventional manner.

Flame retardancy: Flame retardancy was measured in a conventional manner for 1/16 inch thickness of specimen in accordance with UL94.

Flame retardancy and total burn time were measured with two sets of five specimens.

Table 1 shows the results of the measured physical properties.

Comparative example

A resin composition was prepared by compounding by the method used in the above examples except for using the components and the composition ratios shown in Table 1.

The composition and measured physical property results of each component used in Comparative Examples 1 to 3 are shown in Table 1.

Example Comparative example One 2 3 4 One 2 3 ingredient PC 75 75 75 75 75 75 75 g-ABS 10 10 10 10 10 10 10 SAN 15 15 15 15 15 15 15 SPS-100 4 6 6 5 12 0 One RDP 8 6 6 5 0 12 11 PTFE (800J) 0.4 0.4 0.4 0.4 0.4 0.4 0.4 Aluminum hydroxide 0 0 0.1 One 0 0 0 Antimony trioxide 0 0 0.1 One 0 0 0 Properties HDT (℃) 84 86 86 90 92 77 79 Notched Izod Impact (kgfcm / cm) 52 55 53 51 57 20 22 UL94 V-0 (1/16 ") 1 set 2 sets V-0V-0 V-0V-0 V-0V-0 V-0V-0 V-1V-1 V-1V-0 V-1V-0 Average total burn time (sec) 1 set 2 sets 2825 3529 2118 4238 137128 9865 9570

※ PC: Aromatic Polycarbonate

g-ABS: rubber modified styrene-containing graft copolymer

SAN: Styrene-containing copolymer resin

SPS-100: Phosphagen

RDP: Phosphate Ester

PTFE: Polytetrafluoroethylene

HDT: Heat Deflection Temperature

V-0: Good flame retardancy. V-1: Flame retardant medium.

As shown in Table 1, Examples 1 to 4 were mixed with phosphazene and phosphate ester in a predetermined ratio to prepare a resin composition excellent in heat resistance, impact strength and flame retardancy at the same time.

In addition, when comparing Examples 2 and 3, Example 3 was added to the phosphazene / phosphate ester ratio of a small amount of aluminum hydroxide and antimony trioxide as a flame retardant adjuvant, the average total burning time of the five specimens without significant decrease in the impact strength It takes less than 2 was confirmed that the flame retardancy is improved.

In Example 4, by reducing the phosphazene / phosphate ester flame retardant content, by adding the aluminum hydroxide and antimony trioxide by the reduced amount it was confirmed that the flame resistance is excellent and at the same time the heat resistance is greatly improved.

In Comparative Example 1, phosphazene alone was used, but heat resistance and impact strength were excellent, but flame retardancy was not good.

In Comparative Example 2, the use of phosphate ester alone was unstable to secure flame retardancy and severely decreased heat resistance and impact strength.

Therefore, when phosphazene / phosphate ester is used at a constant ratio (phosphazene: phosphate ester = 85:15 to 15:85), a great synergistic effect is found in flame retardancy, and when it is out of the range, the flame retardancy is increased as in Comparative Example 3. There was no effect and it was confirmed that the impact strength was reduced.

The polycarbonate-based thermoplastic resin composition of the present invention can be expected to have excellent heat resistance, impact strength and flame retardancy at the same time than when phosphazene or phosphate ester compound is used alone by mixing phosphazene and phosphate ester in an optimum ratio. have.

Claims (10)

(A) Halogen-free thermoplastic polycarbonate resin 40 to 95% by weight, (B) Halogen-free rubber modified styrene-containing graft copolymer resin 4 to 50% by weight, (C) Halogen-free styrene To 100 parts by weight of the base resin composition consisting of 1 to 30% by weight of the containing copolymer, 1 to 20 parts by weight of (D) phosphazene compound and (E) phosphate ester compound, and (F) 0.05 to 2.0 parts by weight of fluorinated polyolefin resin. And a component (D) :( E) is 85: 15-15: 85 The flame-retardant polymer resin composition according to claim 1, wherein the component (D) phosphazene compound has a structure represented by the following general formula (2). (n is an integer of 3 to 25 for the phosphazene compound and an integer of 3 to 1000 for the linear compound.) The flame retardant polymer resin composition according to claim 2, wherein each of R ¹ and R ² has a structure represented by the following general formula (3): (R ³ and R ⁴ are hydrogen atoms or alkyl groups having 1 to 4 carbon atoms.) The flame-retardant polymer resin composition according to any one of claims 1 to 3, wherein the component (E) phosphate ester compound has a structure represented by the following general formula (4). (Ar ¹ to Ar ⁴ is one selected from the group consisting of cresyl, phenyl, xylene, propylphenyl, butylphenyl, R is arylene, n is 0-5.) The flame retardant polymer resin composition according to claim 4, wherein two or more substituted (E) phosphate ester compounds are mixed as described above. The flame-retardant polymer resin composition according to claim 4, wherein the average value of n is 0.5 to 1.5. The flame retardant polymer resin composition according to claim 4, wherein Ar ¹ to Ar ⁴ are each phenyl and R is phenylene. The flame retardant polymer resin composition according to claim 7, wherein R is 1,3-phenylene. The flame-retardant polymer resin composition according to claim 7, wherein R is a formula (5) The flame retardant polymer resin composition according to any one of claims 1 to 3, further comprising 0.01 to 2.0 parts by weight of aluminum hydroxide and antimony trioxide, respectively, based on 100 parts by weight of the base resin composition.