KR100348750B1 - Flame Retardant Thermoplastic Resin Composition - Google Patents

Abstract

The present invention provides a flame retardant thermoplastic resin composition comprising (A) 100 parts by weight of at least one kind of thermoplastic resin and (B) 1 to 35 parts by weight of an alkyl phosphoramidate compound having the following structural formula (I):

(I)

Wherein R ₁ is an aryl group or an alkyl substituted aryl group, R ₂ and R ₃ are C ₁ -C ₈ alkyl groups and m is 1 or 2.

Description

Flame Retardant Thermoplastic Resin Composition

Field of invention

The present invention relates to a flame retardant thermoplastic resin composition. More specifically, the present invention relates to a thermoplastic resin composition which further enhances flame retardancy by using a compound specific to the thermoplastic resin as a flame retardant.

Background of the Invention

Research on improving the flame retardancy of thermoplastic resins has long been a major goal in resin research and development. Flame retardancy is typically assessed according to the UL-94 evaluation standard as defined by the Underwriters Laboratory. In this flame retardancy evaluation, if each specimen was flamed for less than 10 seconds after being flamed and two specimens were flamed twice, the V-0 rating would be obtained if the total flame out time was less than 50 seconds. Can be.

The most widely known flame retardant method is to impart flame retardant properties by applying a halogen-based compound and an antimony-based compound together to the rubber-modified styrene resin. As the halogen-based compound, polybromodiphenyl ether, tetrabromobisphenol A, a brominated substituted epoxy compound, chlorinated polyethylene and the like are mainly used. Antimony trioxide and antimony pentoxide are mainly used as an antimony compound.

The application of halogen and antimony compound together to impart flame retardancy has the advantage of easy flame retardancy and little property deterioration.However, the hydrogen halide gas generated during processing can damage the mold and burn during combustion. The occurrence of such a gas is likely to have a fatal effect on the human body. In particular, polybrominated diphenyl ethers, which are mainly halogen-based flame retardants, have a high possibility of generating very toxic gases such as dioxins and furans during combustion.

Therefore, as interest in environmental problems increases, a method of imparting flame retardance to a resin composition by adding a compound such as phosphorus or nitrogen as a flame-retardant containing no halogen generating toxic gases has been studied. Phosphorus-based flame retardants mainly used to date include monophosphates such as triphenyl phosphate and tricresyl phosphate, resorcinol bis (diphenyl phosphate), hydroquinone bis (diphenyl phosphate), bisphenol abis (diphenyl phosphate), and the like. Like oligophosphates and the like. However, the phosphorus compound alone has a disadvantage in that the heat resistance of the rubber-modified styrene-based resin is lowered and the flame retardancy is insufficient. In addition, since these flame retardants are excessively used in nature, they may lead to a decrease in physical properties such as impact strength.

Therefore, in order to solve this disadvantage, the present inventors have developed a flame-retardant thermoplastic resin composition containing a phosphate-based flame retardant such as alkyl phosphoramidate, which is different from the above, which can minimize the deterioration of physical properties such as impact strength of the thermoplastic resin. Reached.

An object of the present invention is to provide a flame retardant thermoplastic resin composition.

Another object of the present invention is to provide a flame retardant thermoplastic resin composition containing no halogen compound which causes environmental pollution during processing or combustion of the resin.

Still another object of the present invention is to provide a flame retardant thermoplastic resin composition containing a phosphate flame retardant such as alkyl phosphoroamidate capable of minimizing physical property degradation such as impact strength of the thermoplastic resin.

Still another object of the present invention is to provide a flame retardant thermoplastic resin composition useful in manufacturing molded articles such as housings of electrical and electronic products due to excellent workability during injection molding but no black streaks.

The above and other objects of the present invention can be achieved by the following description. Hereinafter, the content of the present invention will be described in detail.

The flame retardant thermoplastic resin composition of the present invention comprises (A) 100 parts by weight of at least one kind of thermoplastic resin and (B) 1 to 35 parts by weight of an alkyl phosphoramidate compound having the following structural formula (I) as a flame retardant:

(I)

Wherein R ₁ is an aryl group or an alkyl substituted aryl group, R ₂ and R ₃ are C ₁ -C ₈ alkyl groups and m is 1 or 2.

Detailed description of the invention

The flame retardant thermoplastic resin composition of the present invention includes at least one type of thermoplastic resin (A) and a flame retardant (B), which will be described in detail as follows.

(A) thermoplastic resin

The thermoplastic resin (A) which is a main component of the thermoplastic resin composition of the present invention comprises at least one thermoplastic resin composition listed below. In other words, the thermoplastic resin (A) may be a polyolefin resin such as polyethylene or polypropylene; Thermoplastic resins composed of vinyl carboxylic acids such as polyalkylacrylates, polyalkylmethacrylates, polyacrylamides, polyacrylonitriles or polyacrylic acids, or derivatives thereof; Polystyrene-based vinyl aromatic resins; Diene resins such as polybutadiene or polyisoprene; Polyamide-based resins such as nylon-6 or nylon-6,6; Polyester resins such as polyethylene terephthalate or polybutylene terephthalate; Polycarbonate resins; And at least one selected from the group consisting of polyphenylene ether resins and the like.

The thermoplastic resin (A) of the present invention includes both a homopolymer and a copolymer, and the copolymer includes all of random, block or graft copolymers. Examples thereof include high impact polystyrene (HIPS), acrylonitrile-butadiene-styrene graft copolymer (ABS), and the like, which are polystyrene resins.

Preferred examples of the thermoplastic resin (A) of the present invention include polycarbonate resin, polyphenylene ether resin, polyester resin, high impact polystyrene, or styrene-acrylonitrile copolymer (including ABS copolymer) resin. . In addition, each of the above resins may be used alone or in a blend. Among these, when the thermoplastic resin (A) is used as a blend, polyphenylene ether / vinyl aromatic polymer (including HIPS), polyphenylene ether / vinyl aromatic copolymer (including ABS), polycarbonate / vinyl aromatic copolymer (ABS And polycarbonate / polyester blends.

(A ₁ ) polycarbonate resin

The polycarbonate-based resin (A ₁ ) which can be used in the thermoplastic resin of the present invention is a halogen-free aromatic polycarbonate, and diphenols represented by the following structural formula (II) include phosgene, halogen formate, or dicarbonate. Prepared by reacting with esters:

(Ⅱ)

Wherein A is a single bond, alkylene of C _1-5 , alkylidene of C _2-5 , cycloalkylidene of C _5-6 , —S— or —SO ₂ —.

Examples of the diphenols represented by the structural formula (II) include hydroquinone, resorcinol, 4,4'-dihydroxydiphenyl, 2,2'-bis- (4-hydroxyphenyl) -propane, and 2,4-bis -(4-hydroxyphenyl) -2-methylbutane, 1,1'-bis- (4-hydroxyphenyl) -cyclohexane, 2,2'-bis- (3-chloro-4-hydroxyphenyl) -Propane, 2,2'-bis- (3,5-dichloro-4-hydroxyphenyl) -propane, etc. are mentioned. Among them, 2,2'-bis- (4-hydroxyphenyl) -propane, 2,2'-bis- (3,5-dichloro-4-hydroxyphenyl) -propane, 1,1'-bis- (4-hydroxyphenyl) -cyclohexane and the like. Bisphenols are preferable, and 2,2'-bis- (4-hydroxyphenyl) -propane also called bisphenol-A is more preferable.

The polycarbonate-based resin (A ₁ ) that can be used in the thermoplastic resin of the present invention has a weight average molecular weight (M _w ) of 10,000 to 200,000, preferably 15,000 to 80,000. The polycarbonate-based resin (A ₁ ) may be a branched chain, preferably prepared by adding a compound having 0.05 to 2 mol% of a trivalent or more phenol group based on the total amount of diphenols used in the polymerization. Can be. The polycarbonate (PC) used in the preparation of the resin composition of the present invention may be used in the form of a homopolymer, a copolymer, or a mixture thereof. In addition, the polycarbonate-based resin (A ₁ ) may be used in part or in whole by an aromatic polyester-carbonate resin obtained by polymerizing in the presence of a bifunctional carboxylic acid which is an ester precursor.

(A ₂ ) polyphenylene ether resin

Polyphenylene ether resin (A ₂ ) that can be used in the thermoplastic resin of the present invention has an excellent effect in reinforcing flame retardancy, rigidity and heat resistance.

Examples of the polyphenylene ether resin (A ₂ ) include poly (2,6-dimethyl-1,4-phenylene) ether, poly (2,6-diethyl-1,4-phenylene) ether, and poly (2 , 6-dipropyl-1,4-phenylene) ether, poly (2-methyl-6-ethyl-1,4-phenylene) ether, poly (2-methyl-6-propyl-1,4-phenylene ) Ether, poly (2-ethyl-6-propyl-1,4-phenylene) ether, poly (2,6-diphenyl-1,4-phenylene) ether, poly (2,6-dimethyl-1, Copolymer of 4-phenylene) ether and poly (2,3,6-trimethyl-1,4-phenylene) ether, and poly (2,6-dimethyl-1,4-phenylene) ether and poly (2 And copolymers of 3,5-triethyl-1,4-phenylene) ether. Preferably a copolymer of poly (2,6-dimethyl-1,4-phenylene) ether and poly (2,3,6-trimethyl-1,4-phenylene) ether, and poly (2,6-dimethyl -1,4-phenylene) ether is used, more preferably poly (2,6-dimethyl-1,4-phenylene) ether. In addition, the polyphenylene ether resin (A ₂ ) may be used alone or in combination of two or more thereof in an appropriate ratio.

All of the above polyphenylene ethers are compatible with polystyrene at all mixing ratios. Although the degree of polymerization of the polyphenylene ether is not particularly limited, it is preferable that the intrinsic viscosity measured in the chloroform solvent at 25 ° C. is 0.2 to 0.8 in consideration of thermal stability and workability of the resin composition.

(B) alkyl phosphoramidate compounds

The alkyl phosphoramidate compound is added to the thermoplastic resin (A) of the present invention as a main component to enhance flame retardancy, and is an alkyl phosphoramidate compound which is a phosphate-based flame retardant having the following structural formula (I), in the present invention It is used in 1 to 35 parts by weight:

(I)

Wherein R ₁ is an aryl group or an alkyl substituted aryl group, R ₂ and R ₃ are C ₁ -C ₈ alkyl groups and m is 1 or 2.

R ₁ is selected from the group consisting of phenyl group, cresyl group, t-butylphenyl group, isopropylphenyl group, etc., wherein R ₂ and R ₃ are methyl group, ethyl group, propyl group, isopropyl group, n-butyl group, t- Butyl group, pentyl group, neopentyl group, isopentyl group and the like. Among these, particularly preferred R ₁ is a phenyl group or a cresyl group, and preferred R ₂ and R ₃ include an isopropyl group or n-butyl group.

The method for producing the alkyl phosphoroamidate compound (B) is not particularly limited, and can be obtained by, for example, reacting an aromatic alcohol with a tertiary amine to phosphorus oxychloride (POCl ₃ ). It is preferable to use 1-35 weight part with respect to 100 weight part of thermoplastic resins (A), More preferably, 5-30 weight part is used.

(C) other flame retardants and flame retardants

Optionally, the thermoplastic resin composition of the present invention is generally widely commercialized such as other organic phosphoric acid ester compounds, halogen-containing organic compounds, cyanate compounds, metal salts, etc., in addition to the alkyl phosphoroamidate compounds (B) described above for improving flame retardancy. Added flame retardants and flame retardants may be used.

Examples of the organic phosphate ester compound that can be used include phosphate ester monomer compounds such as triphenylphosphate and tricresylphosphate, and condensed phosphate esters derived from dihydric alcohols such as resorcinol, hydroquinone and bisphenol-A. The metal salts that can be used as flame retardant aids include conventionally known sulfonic acid metal salts and sulfone sulfonic acid metal salts.

(D) anti-dripping agent

In addition, an antidripping agent may be further used in the thermoplastic resin composition of the present invention. The resin that can be used as the anti-dripping agent is a fluorinated polyolefin resin, and the fluorinated polyolefin resin is a polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene / vinylidene fluoride copolymer, tetrafluoro Low ethylene / hexafluoropropylene copolymer, ethylene / tetrafluoroethylene copolymer, and the like. These may be used independently, respectively and may be used in mixture of 2 or more types different from each other. It may be used in combination.

The thermoplastic resin composition of the present invention may further include general additives such as lubricants, mold release agents, nucleating agents, antistatic agents, stabilizers, reinforcing agents, inorganic additives, pigments and / or dyes, and the like. May be used in the range of 0 to 60 parts by weight, preferably 10 to 40 parts by weight based on 100 parts by weight of the thermoplastic resin (A).

The resin composition of the present invention can be produced by a known method for producing a resin composition. For example, the components of the present invention and other additives may be mixed simultaneously, then melt extruded in an extruder and prepared in pellet form.

The composition of the present invention can be used for molding various products, and is particularly suitable for the manufacture of electrical and electronic product housings that require excellent flame retardancy, mechanical properties, and excellent moldability.

The invention can be 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) thermoplastic resin, (B) alkyl phosphoramidate, (C) other flame retardants and flame retardant aids and (D) dropwise used in the flame retardant thermoplastic resin compositions of Examples 1 to 2 and Comparative Examples 1 to 4 below. Preparation and specification of the inhibitor are as follows.

(A) thermoplastic resin

(A ₁ ) polycarbonate resin (PC)

A bicarbonate-type polycarbonate having a melt flow index (250 ° C., 10 kg load) of 20 g / 10 min, measured according to ASTM D1238, was used.

(A ₂ ) Rubber modified graft copolymer (ABS)

Butadiene rubber latex was added so that the butadiene content was 45 parts by weight based on the total amount of the monomer, 1.0 parts by weight of potassium oleate, cumene hydroperoxide, which was an additive necessary for a mixture of 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, 0.3 parts by weight of mercaptan-based chain transfer agent was added to react while maintaining at 75 ℃ for 5 hours to prepare an ABS graft latex. 1% sulfuric acid solution was added to the resultant polymer latex to coagulate and dried to prepare a graft copolymer resin in powder form.

(A ₃ ) Vinyl Copolymer Resin (SAN)

A SAN copolymer resin was prepared by suspension polymerization by adding 0.2 parts by weight of azobisisobutyronitrile and 0.5 parts by weight of tricalcium phosphate, which are necessary additives to a mixture of 70 parts by weight of styrene, 30 parts by weight of acrylonitrile, and 120 parts by weight of deionized water. . The copolymer was washed with water, dehydrated and dried to obtain a SAN copolymer resin in powder form.

(A ₄ ) polyphenylene ether resin (PPE)

The polyphenylene ether resin used in the examples of the present invention was PPE P401 from Asahi Kasei of Japan.

(A ₅ ) High Impact Polystyrene Resin (HIPS)

The high impact polystyrene resin used in the embodiment of the present invention was HI-1190, a product of Cheil Industries, Korea.

(B) alkyl phosphoramidates

As the flame retardant added to the thermoplastic resin of the present invention, alkyl phosphoramidate, which is a flame retardant used in Examples 1 and 2, has an average value of m of 1.2, R ₁ is a phenyl group, and R ₂ and R ₃ are n-butyl groups. It was a compound.

(C) other flame retardants and flame retardants

(C ₁ ) resorcinol bis (diphenylphosphate)

The phosphate ester compound used in Comparative Examples 2 and 4 as the flame retardant added to the thermoplastic resin (A) of the present invention was CR-733S from Nihachihachi Chemical Co., Ltd. which is resorcinol bis (diphenylphosphate).

(C ₂ ) Bisphenol A bis (diphenyl phosphate)

The phosphoric acid ester compound used in Comparative Examples 1 and 3 as the flame retardant added to the thermoplastic resin (A) of the present invention was CR-741S of Nippon Daihachi Chemical Co., Ltd. which is bisphenol A bis (diphenylphosphate).

(D) anti-dripping agent

Fluorinated polyolefin resin of Teflon (trade name) 7AJ of Dupont, USA was used.

Using the above-mentioned components, a resin composition was prepared as shown in Table 1 below.

division Example Comparative Example One 2 One 2 3 4 Ingredients (parts by weight) (A) Polycarbonate resin 80 - 80 80 - - Rubber Modified Graft Copolymer Resin 10 - 10 10 - - Vinyl copolymer resin 10 - 10 10 - - Polyphenylene ether resin - 70 - - 70 70 High Impact Polystyrene Resin - 30 - - 30 30 (B) alkyl phosphoramidates 16 15 - - - - (C) Resorcinol bis (diphenylphosphate) - - - 16 - 15 Bisphenol A bis (diphenyl phosphate) - - 16 - 15 - (D) fluorinated polyolefin resin 0.5 0.5 0.5 0.5 0.5 0.5

The components of Examples 1 to 2 and Comparative Examples 1 to 4 shown in Table 1, antioxidants and heat stabilizers were added, mixed in a conventional mixer, and used in a twin screw extruder having L / D = 35 and Φ = 45 mm. After extruding, the extrudates were prepared in pellet form, and then specimens for physical properties measurement and flame retardancy evaluation were prepared at an injection temperature of 250 ° C. After the specimens were allowed to stand at 23 ° C. and 50% relative humidity for 48 hours, their physical properties were measured according to ASTM standards. Izod impact strength was evaluated using a 3.2 mm thick, V-notched specimen in accordance with ASTM D256. The flame retardancy was evaluated using 1.2 mm thick specimens in accordance with UL94. The total combustion time is the sum of both primary and secondary combustion times when five specimens were evaluated. The melt flow index was evaluated according to ASTM D1238, and the measurement conditions were evaluated at 250 ° C. and 10 kg load. The thermal stability and appearance of the resin compositions prepared in Examples and Comparative Examples were judged as the occurrence of black streak appearing on the surface of the injection molding when a plate having a size of 200 mm × 50 mm × 2 mm was injected (below). In Table 2, black lines frequently appear as ×, and when black lines do not occur, they are marked as ○, and when black lines are generated according to conditions, they are marked as Δ). The injection temperature was changed in the range of 260-300 degreeC, and it evaluated while changing also injection pressure and speed | rate. These physical property measurement results are summarized in Table 2 below.

division Example Comparative Example One 2 One 2 3 4 Properties Izod impact strength (kgfcm / cm) (ASTM D256) 60 22 38 41 14 15 Flame retardant (UL 94) V-0 V-0 V-1 V-1 V-1 V-1 Total burning time (seconds) 38 34 79 57 72 54 Melt Flow Index (g / 10 min) (ASTM D1238) 57 11 37 42 6 7 Appearance (black line) ○ - △ × - -

As can be seen in the Examples and Comparative Examples of Table 2, Examples 1 to 2 using alkyl phosphoramidate as a flame retardant, having excellent flame retardancy and impact strength, excellent fluidity, and black streaks It was found that the moldability was excellent.

The flame retardant thermoplastic resin composition of the present invention does not contain a halogen compound and thus does not cause environmental pollution during the processing or combustion of the resin. Minimizes the physical property degradation of, and has excellent workability during injection molding but no black streak has a useful effect in manufacturing molded articles such as housing of electrical and electronic products.

Simple modifications or changes of the present invention can be easily carried out by those skilled in the art, and all such modifications or changes can be seen to be included in the scope of the present invention.

Claims (13)

A flame retardant thermoplastic resin composition comprising (A) 100 parts by weight of at least one type of thermoplastic resin and (B) 1 to 35 parts by weight of an alkyl phosphoramidate compound having the following structural formula (I): (I) Wherein R ₁ is an aryl group or an alkyl substituted aryl group, R ₂ and R ₃ are C ₁ -C ₈ alkyl groups and m is 1 or 2. The method of claim 1, wherein the thermoplastic resin (A) is a polyolefin resin such as polyethylene or polypropylene; Thermoplastic resins composed of vinyl carboxylic acids such as polyalkylacrylates, polyalkylmethacrylates, polyacrylamides, polyacrylonitriles or polyacrylic acids, or derivatives thereof; Polystyrene-based vinyl aromatic resins; Diene resins such as polybutadiene or polyisoprene; Polyamide-based resins such as nylon-6 or nylon-6,6; Polyester resins such as polyethylene terephthalate or polybutylene terephthalate; Polycarbonate resins; And at least one member selected from the group consisting of polyphenylene ether resins and the like. The method of claim 1, wherein the thermoplastic resin (A) is a blend of polyphenylene ether and a vinyl aromatic polymer, a blend of polyphenylene ether and a vinyl aromatic copolymer, a blend of a polycarbonate and a vinyl aromatic copolymer, or a polycarbonate Flame retardant thermoplastic resin composition, characterized in that the blend of polyester. The flame retardant thermoplastic resin composition according to claim 1, wherein the thermoplastic resin (A) is a polystyrene resin or an ABS resin. The flame retardant thermoplastic resin composition according to claim 1, wherein R _{1 in} the structural formula (I) is a phenyl group or a cresyl group. The flame retardant thermoplastic resin composition of claim 1, wherein R ₂ and R ₃ in the structural formula (I) are an isopropyl group or an n-butyl group. The flame retardant thermoplastic resin composition according to claim 1, wherein the resin composition further comprises a flame retardant such as an organic phosphate ester compound, a halogen-containing organic compound, a cyanate compound and / or a metal salt. 8. The method of claim 7, wherein the organic phosphate ester compound is a phosphate ester monomer compound such as triphenylphosphate and tricresylphosphate, or a condensed phosphate ester derived from dihydric alcohols such as resorcinol, hydroquinone, bisphenol-A, and The metal salt is a sulfonic acid metal salt or sulfone sulfonic acid metal salt, flame retardant thermoplastic resin composition. The flame retardant thermoplastic resin composition according to claim 1, wherein the resin composition further comprises a fluorinated polyolefin resin (D). The method of claim 9, wherein the fluorinated polyolefin resin is polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene / vinylidene fluoride copolymer, tetrafluoroethylene / hexafluoropropylene copolymer and ethylene Flame-retardant thermoplastic resin composition, characterized in that at least one selected from the group consisting of / tetrafluoroethylene copolymer, each of two or more different from each other is used. The flame retardant thermoplastic resin composition of claim 1, further comprising a lubricant, a mold release agent, a nucleating agent, an antistatic agent, a stabilizer, a reinforcing agent, an inorganic additive pigment, and / or a dye. The flame retardant thermoplastic resin composition of claim 11, wherein the inorganic additive is used in an amount of 0 to 60 parts by weight based on 100 parts by weight of the thermoplastic resin (A). A molded article processed from the flame retardant thermoplastic resin composition according to any one of claims 1 to 12.