KR20040061939A - Flameproof Thermoplastic Resin Composition - Google Patents

Abstract

PURPOSE: A flame retardant thermoplastic resin composition is provided to improve impact strength, heat resistance and compatibility and dispersion of a resin with a phosphor-based flame retardant. CONSTITUTION: The thermoplastic resin composition comprises 100 parts by weight of a thermoplastic resin; 1-50 parts by weight of a capsulated phosphor-based compound obtained by coating a dialkyl pentaerythritol diphosphonate of the formula 1 with a polystyrene resin; and optionally 0-5 parts by weight of a fluorinated polyolefin-based resin, wherein R is an alkyl group of C1-C4. Preferably the capsulated phosphor-based compound is obtained by preparing a dual emulsion of water in oil in water (W1/O/W2) and evaporating the solvent in oil, wherein the emulsifying agent required for preparing a W1/O emulsion has a hydrophilic lypophilic balance (HLB) greater than 3 and less than 6, and the emulsifying agent required for preparing an O/W2 emulsion has an HLB greater than 13 and less than 18.

Description

Flameproof Thermoplastic Resin Composition

Field of invention

The present invention relates to a flame retardant thermoplastic resin composition excellent in impact properties. More specifically, the present invention relates to a flame retardant thermoplastic resin composition having excellent impact properties by increasing the dispersibility and compatibility with the resin by applying an encapsulated phosphorus compound coated with a polystyrene resin with a water-soluble phosphorus compound as a flame retardant to the thermoplastic resin. .

Background of the Invention

The most well known method of imparting flame retardancy to thermoplastic resins is to impart flame retardancy by adding halogen-based flame retardants. However, halo-based flame retardants exhibit excellent flame retardancy regardless of the resin type, but they cause corrosion of processing equipment such as molds due to the generation of corrosive gases during processing, and toxic gases such as dioxins, furans, and hydrogen halide gases during combustion. There is a risk of generating gas.

As an alternative to solve the problem of the halogen-based flame retardant, a method of imparting flame retardancy to the resin composition by adding a compound containing phosphorus or nitrogen has been studied. However, when the phosphorus compound is used as a flame retardant, not only the heat resistance of the thermoplastic resin is lowered, but also the compatibility with the resin is poor, and mechanical strength is seriously lowered.

In order to solve this problem, it has been developed to encapsulate a flame retardant.

US Pat. No. 4,440,880 discloses a method for encapsulating a lobe with melamine resin to increase the stability of the lobe in air.

In addition, US Pat. No. 5,561,174 discloses an encapsulation method using an epoxy resin and a curing agent to improve the hygroscopicity of the inorganic filler. However, the above method is encapsulated with a thermosetting resin, and there is a problem of incompatibility with the styrene resin.

Accordingly, the present inventors use encapsulated flame retardants in which a flame retardant is encapsulated with a polystyrene resin by a double emulsification method in order to overcome the above problems, thereby improving compatibility and dispersibility with thermoplastic resins, and thus having excellent impact strength. It has begun to develop a flame retardant thermoplastic resin composition.

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

Another object of the present invention is to provide a flame retardant thermoplastic resin composition excellent in heat resistance.

Still another object of the present invention is to provide a flame retardant thermoplastic resin composition having improved compatibility and dispersibility of a phosphorus flame retardant and a resin.

The above and other objects of the present invention can be achieved by the present invention described below.

The flame retardant thermoplastic resin composition of the present invention (A) 100 parts by weight of a thermoplastic resin; And (B) 1-50 parts by weight of an encapsulated phosphorus compound coated with dialkyl pentaerythritol diphosphonate with a polystyrene resin; And (C) 0 to 5 parts by weight of the fluorinated polyolefin resin, the detailed description of each of these components is as follows.

(A) thermoplastic resin

The type of thermoplastic resin that can be used in the present invention is basically not limited, and more specific examples are as follows: acrylonitrile-styrene copolymer resin (SAN resin), acrylonitrile-butadiene-styrene copolymer resin ( ABS resin), rubber modified polystyrene resin (HIPS), acrylonitrile-styrene-acrylate copolymer resin (ASA resin), methyl methacrylate-butadiene-styrene resin copolymer resin (MBS resin), acrylonitrile-ethyl Acrylate-styrene copolymer resin (AES resin), polystyrene resin (PS), polycarbonate resin (PC), polyphenylene ether resin (PPE), PE (polyethylene), PP (polypropylene), polyethylene terephthalate (PET) ), Polybutylene terephthalate (PBT), polyvinyl chromide (PVC), polymethyl methacrylate (PMMA) and copolymers of these resins or mixed alloys. It is.

(B) Encapsulated Phosphorus Compound Covered with Polystyrene Resin

In the encapsulation compound of the present invention, the phosphorus compound is coated and encapsulated with a polystyrene resin, and is composed of 30% to 70% of the phosphorus compound and 30% to 70% of the polystyrene resin.

(1) phosphorus compounds

Phosphorus-based compound used as a flame retardant in the present invention is a dialkyl pentaerythritol diphosphonate disclosed in US Patent No. 4,154,721 is a water-soluble phosphorus compound represented by the following formula (1).

[Formula 1]

(Wherein R is a C _1-4 alkyl group)

The substituent of the dialkyl pentaerythritol diphosphonate of the present invention is preferably an alkyl group having 1 to 4 carbon atoms. This is because when the substituent is an aryl group or an alkyl group having 5 or more carbon atoms, it is insoluble in water.

(2) polystyrene resin

In the present invention, polystyrene resin is used to coat the flame retardant.

The polystyrene resin is prepared by bulk polymerization, suspension polymerization or solution polymerization of an aromatic vinyl monomer. Aromatic vinyl monomers include styrene, p-methyl styrene, α-methyl styrene and 4-N-propyl styrene, of which styrene and α-methyl styrene are most preferred.

The polystyrene resin is made by suspension, emulsification and continuous polymerization method, and preferably has a weight average molecular weight of 80,000 to 400,000.

(3) Method of producing encapsulated phosphorus compound

The preparation of the encapsulated phosphorus compound uses a double emulsification method in consideration of the properties of the phosphorus flame retardant and the particle size prepared.

There are two main types of double emulsification: (a) W1 / O / W2 (water in oil in water) and (b) O1 / W / O2 (oil in water in oil). In the present invention, W1 / O / W2 ( water in oilin water) method is preferred. Methods for double emulsification are detailed in the International Journal of Pharmaceutics (A. Silva-Cunha, J.L. Grossiord, F. Puissieux, M. Seiller 158, 1997, 79-89).

In the present invention, two types of emulsifiers are required for the double emulsification: hydrophobic emulsifier (I) for water in oil emulsion and hydrophilic emulsifier (II) for oil in water emulsion.

The type of the emulsifier is not limited, but the emulsifier is selected based on the concept of a hydrophilic lyphophilic balance (HLB) to prepare a stable double emulsion.

First, the primary emulsifier required for the preparation of the W1 / O emulsion uses an HLB value of 3 <HLB <6, and a secondary emulsifier for the preparation of O / W2 uses 13 <HLB <18. In order to satisfy the HLB value, two or more kinds of emulsifiers may be mixed and used.

In the above, the preparation of the W1 / O emulsion to prepare an aqueous solution in which 40 to 70 parts by weight of the phosphorus compound dissolved in the temperature range of 40 ℃ to 80 ℃, 0.1 to 10 parts by weight of the primary emulsifier, 1 to 20 parts by weight of polystyrene The addition is added to the dissolved oil phase and then emulsified using a homogenizer. At this time, the oil used is used to dissolve the polystyrene resin may be a saturated hydrocarbon, aromatic hydrocarbons, alcohols, acetates, ketones and ester compounds having C _6-20 carbon atoms. Specific examples of the oil include n-hexane, THF, benzene, toluene, cyclohexane and the like.

The W1 / O / W2 emulsion is prepared by slowly adding the W1 / O emulsion prepared above to an aqueous solution in which 0.1% to 10% of the secondary emulsifier is dissolved. By slowly stirring the prepared double emulsion to evaporate the oily solvent, it induces solidification of the dissolved polystyrene and obtains a solid capsule membrane.

At this time, the evaporation conditions of the solvent may be used when the solvent is slowly evaporated for 24 hours at room temperature, atmospheric pressure, when the solvent is rapidly evaporated under reduced pressure 50 ℃, and the solvent is evaporated at 50 ℃.

When the capsule is manufactured using the solvent evaporation method, the thickness of the capsule membrane can be easily controlled, and a thin capsule membrane can be formed as compared to the core substance to protect a large number of core substances with a small amount of membrane material.

(C) fluorinated polyolefin resin

Fluorinated polyolefin resins (C) used in the present invention are conventionally available resins as polytetrafluoroethylene, polyvinylidene fluoride, tetrafluoroethylene / vinylidene fluoride copolymer, tetrafluoroethylene / hexa Fluoropropylene copolymers, ethylene / tetrafluoroethylene copolymers, and the like. These may be used independently from each other, and two or more different types may be used together.

When the fluorinated polyolefin resin is mixed and extruded together with the other component resins of the present invention, a fibrillar network is formed in the resin to lower the flow viscosity of the resin during combustion and increase the shrinkage rate to increase the shrinkage. To prevent.

The fluorinated resin used in the preparation of the resin composition of the present invention can be prepared using a known polymerization method, for example, a pressure of 7 to 71 kg / ㎠ and a temperature of 0 to 200 ℃, preferably 20 to 100 It can be prepared in an aqueous medium containing free radical forming catalysts such as sodium, potassium or ammonium peroxydisulfate at conditions of &lt; RTI ID = 0.0 &gt;

The fluorinated polyolefin resin may be used in an emulsion state or a powder state. When the fluorinated polyolefin resin in the emulsion state is used, the dispersibility in the entire resin composition is good, but there is a disadvantage in that the manufacturing process is complicated. Therefore, even if it is powder state, if it can disperse | distribute suitably in whole resin composition and can form a fibrous network, it is preferable to use it in powder state.

Fluorinated polyolefin-based resins which can be preferably used in the preparation of the resin composition of the present invention include polytetrafluoroethylene having a particle size of 0.05 to 1,000 µm and specific gravity of 1.2 to 2.3 g / cm 3.

The content of the fluorinated polyolefin resin used for producing the resin composition of the present invention is 0 to 5 parts by weight.

The flame-retardant thermoplastic resin composition of the present invention may be added to the impact modifier, plasticizer, inorganic additives, heat stabilizers, antioxidants, compatibilizers, light stabilizers, pigments and / or dyes in addition to the above components. The inorganic additives to be added include asbestos, glass fibers, talc, ceramics and sulfates, which may be used in an amount of 0 to 30 parts by weight based on 100 parts by weight of the base resin of the present invention.

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

Specifications of the (A) thermoplastic resin and (B) encapsulated phosphorus compound used in the following Examples and Comparative Examples are as follows.

(A) thermoplastic resin

(A ₁ ) Rubber reinforced polystyrene copolymer (High Impact Polystyrene)

A rubber-modified polystyrene resin prepared by a conventional method, the rubber content is 9% by weight, the size of the average rubber particles is 1.5 ㎛ and the weight average molecular weight of 220,000 polystyrene was used.

(A ₂ ) SAN graft copolymer resin

50 parts by weight of butadiene rubber latex solid, 36 parts by weight of styrene and 14 parts by weight of acrylonitrile are added to 150 parts of deionized water, 1.0 part of potassium oleate, 0.4 part of cumene hydroperoxide, and mercaptan chain 0.2 parts of a moving agent, 0.4 parts of glucose, 0.01 parts of iron sulfate hydrate, 0.3 parts of pyrophosphate sodium salt were added, and then, the reaction mixture was maintained at 75 ° C. for 5 hours to prepare a graft ABS latex. 0.4 parts by weight based on solids was added and solidified to prepare a graft copolymer resin (g-ABS) powder.

(A ₃ ) Styrene-containing copolymer resin

(A ₃₁ ) SAN resin with 25% acrylonitrile content

75 parts by weight of styrene, 25 parts by weight of acrylonitrile, 120 parts of deionized water, 0.15 part of azobisisobutyronitrile, 0.4 part of tricalcium phosphate and 0.2 part of mercaptan-based chain transfer agent were added. After heating up for minutes, the temperature was maintained at this temperature for 180 minutes to prepare a copolymer resin (SAN). This was washed with water, dehydrated and dried to prepare a SAN powder.

(A ₃₂ ) SAN resin with an acrylonitrile content of 13%

Styrene is 87 parts by weight of acrylonitrile is 13 parts by weight, 120 parts of deionized water, 0.1 part of azobisisobutyronitrile, 1,1'di (tertiarybutylperoxy) 3,3 ', 5trimethylcyclohexane 0.2 part , 0.4 parts of tricalcium phosphate and 0.2 part of mercaptan-based chain transfer agent were added. Next, after raising the temperature from room temperature to 80 ° C. for 90 minutes, the temperature was maintained at this temperature for 150 minutes, the temperature was further increased to 95 ° C., and maintained for 120 minutes to prepare a copolymer resin (SAN) having an acrylonitrile content of 13%. . This was washed with water, dehydrated and dried to prepare a SAN powder.

(A ₄ ) polystyrene resin

Cheil Industries Co., Ltd. used GPPS (trade name HF-2680) having an average molecular weight of 210,000.

(A ₅ ) polycarbonate resin

A linear bisphenol-A polycarbonate having a weight average molecular weight of 25,000 was used.

(A ₆ ) polyphenylene ether resin

Poly (2,6-dimethyl-phenylether) (trade name P-402) of Asahi Kasei Co., Ltd., Japan, was used, and the particle size was in the form of a powder having an average particle diameter of several tens of micrometers.

(B ₁ ) Encapsulated Phosphorus Flame Retardant

After dissolving 25 g of dimethyl pantaerythritol diphosphonate, a water-soluble flame retardant, in 25 g of 50 ° C. distilled water, the aqueous solution was dissolved in 5 g of Pluronic L61, a hydrophobic surfactant, and an average molecular weight of 210,000 polystyrene. ]) 5 g of dissolved cyclohexane (cyclohexane) 45g solution was added. W1 / O emulsion was prepared by emulsifying for 3 minutes at a rotational speed of 16,000 rpm at room temperature using a homogenizer (Homogenizer). Next, the prepared W1 / O emulsion was slowly emulsified for 10 minutes at a rotational speed of 500 rpm with a mechanical stirrer while slowly adding 5 g of Triton X-405, a hydrophilic surfactant, to the external water phase dissolved in 400 g of distilled water for 5 minutes. A double emulsion of W1 / O / W2 was prepared.

The double emulsion of W1 / O / W2 prepared above was stirred at a speed of 80 rpm under normal temperature and reduced pressure to evaporate an oily solvent to induce solidification of dissolved polystyrene, thereby obtaining a solid capsule membrane. The average particle size of the capsule obtained at this time was 10 ㎛ and the content rate of the flame retardant was 70%.

(B ') Dimethyl pentaerythritol diphosphonate

Phosphorus content of 24.2% and white solid dimethyl pentaerythritol diphosphonate was used without encapsulation.

(C) fluorinated polyolefin resin

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

Examples 1-5

Each component was added in the amounts shown in Table 1 below, and extruded in a conventional twin screw extruder at a temperature range of 200 ~ 280 ℃ to prepare a pellet. The prepared pellets were dried at 80 ° C. for 3 hours and then injected into a 6 Oz injection machine under molding conditions of 180 to 280 ° C. and mold temperatures of 40 to 80 ° C. to prepare flame retardant specimens.

Comparative Examples 1 to 5

Dimethyl pentaerythritol diphosphonate as a flame retardant was carried out in the same manner as in the above except that it was added without encapsulation.

Table 1 shows the composition and test results of each component used in Example 1-5 and Comparative Example 1-5.

Item Example Comparative Example One 2 3 4 5 One 2 3 4 5 (A) (A ₁ ) Rubber reinforced polystyrene resin 80 - - - - 80 - - - - (A ₂ ) SAN graft copolymer resin - 10 20 5 35 - 10 20 5 35 (A ₃₁ ) SAN resin (AN content 25%) - 15 35 - 65 - 15 35 - 65 (A ₃₂ ) SAN resin (AN content 13%) - - 15 - - - - 15 - - (A ₄ ) polystyrene resin - - - - - 4.5 6 6 1.8 1.5 (A ₅ ) PC - 70 - 95 - - 70 - 95 - (A ₆ ) PPE 20 - 30 - - 20 - 30 - - (B) Encapsulated Phosphorus Compound 15 20 20 6 5 - - - - - (B ') Phosphorus Flame Retardant - - - - 10.5 14 14 4.2 3.5 (C) fluorinated polyolefin resin - 0.5 - 0.5 - - 0.5 - 0.5 - Heat resistance degree (℃) 104 93 92 134 93 102 91 88 130 93 Izod impact strength (1/8 ") 9 38 24 55 21 3 15 7 22 11 UL94 flame retardant (1/12 ") V-0 V-0 V-0 V-0 V-2 V-0 V-0 V-0 V-0 Fail

The prepared specimens were measured for flame retardancy according to UL 94 VB flame retardant regulations. Izod impact strength was measured under ASTM 256A condition at 1/8 "thickness and heat resistance at 5 kgf load according to ASTM D 1525.

From the results of Table 1, it can be seen that in Comparative Example 1-5 in which the dialkyl pentaerythritol diphosphonate was added without encapsulation, the flame retardancy was excellent, but the impact physical properties were severely reduced. However, in the case of Example 1-5 coated with dialkyl pentaerythritol diphosphonate using polystyrene resin, it is confirmed that the impact strength can be prevented from being lowered as the compatibility with the resin is improved and the dispersibility is improved. Could.

The present invention uses an encapsulated phosphorus compound encapsulated with a polystyrene resin as a water-soluble phosphorus flame retardant as a flame retardant of a thermoplastic resin, thereby increasing dispersibility and compatibility with the resin to prevent degradation of the resin properties, as well as impact properties and heat resistance It has the effect of providing an excellent flame retardant thermoplastic resin composition.

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 (8)

(A) 100 parts by weight of thermoplastic resin; And (B) 1-50 parts by weight of an encapsulated phosphorus compound coated with a distyrene pentaerythritol diphosphonate represented by Formula 1 with a polystyrene resin; Flame-retardant thermoplastic resin composition, characterized in that consisting of. [Formula 1] Wherein R is a C _1-4 alkyl group. The method of claim 1, wherein the thermoplastic resin is acrylonitrile-butadiene-styrene copolymer resin (ABS resin), rubber modified polystyrene resin (HIPS), acrylonitrile-styrene-acrylate copolymer resin (ASA resin), methyl Methacrylate-butadiene-styrene resin copolymer resin (MBS resin), acrylonitrile-ethylacrylate-styrene copolymer resin (AES resin), polycarbonate resin (PC), polyphenylene ether resin (PPE), PE (Polyethylene), PP (polypropylene), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyvinyl chloride (PVC), polymethyl methacrylate (PMMA) and copolymers thereof Flame retardant thermoplastic resin composition, characterized in that one or a mixture thereof. The method of claim 1, wherein the encapsulated phosphorus-based compound is prepared by preparing a double emulsion of water in oil in water (W1 / O / W2) and then evaporating the solvent in the oil phase, in preparing the W1 / O emulsion during the preparation of the double emulsion. The required emulsifier has a HLB (Hydrophilic lyphophilic balance) value of 3 <HLB <6, the emulsifier for O / W2 production is 13 <HLB <18, characterized in that the flame retardant thermoplastic resin composition. The method of claim 1, wherein the encapsulated phosphorus-based compound is emulsified in an aqueous solution of dialkyl pentaerythritol diphosphonate on the emulsifier and the oil in the polystyrene to prepare a W1 / O emulsion, the W1 / O emulsion emulsifier Is added to the dissolved aqueous solution to prepare a W1 / O / W2 emulsion, and the W1 / O / W2 emulsion is stirred to evaporate an oily solvent to prepare a flame retardant thermoplastic resin composition. The flame retardant thermoplastic resin composition of claim 1, wherein the polystyrene resin has a weight average molecular weight of 80,000 to 400,000. The flame retardant thermoplastic resin composition of claim 1, wherein the oil is selected from the group consisting of C _6-20 saturated hydrocarbons, aromatic hydrocarbons, alcohols, acetates, ketones and ester compounds. The flame retardant thermoplastic resin composition according to claim 1, wherein the resin composition further comprises 5 parts by weight or less of a fluorinated polyolefin resin (C). The thermoplastic resin composition of claim 1, wherein the resin composition further includes a plasticizer, a heat stabilizer, an antioxidant, a light stabilizer, a compatibilizer, a pigment and / or a dye, and an inorganic additive.