KR19990054644A - Thermoplastic Flame Retardant Resin Composition - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic flame retardant resin composition, and has a low impact strength as a polystyrene resin in an alloy resin of a polycarbonate resin and a polystyrene resin, which is mainly used in electronic parts and electronic parts of automobile parts, and has excellent rigidity and formability. A styrene-acrylonitrile resin is used, and a polystyrene-based resin including a functional group copolymerizable with an aromatic vinyl compound and an aromatic vinyl compound and a vinyl cyan compound in the presence of a conjugated diene rubber polymer for improving the compatibility and physical properties of the resin. Flame retardant is improved by adding brominated flame retardant and glycidyl-containing flame retardant, which is excellent in impact resistance, heat resistance and fluidity. This is excellent.

Description

Thermoplastic Flame Retardant Resin Composition

The present invention relates to a thermoplastic flame retardant resin composition, and more particularly, as a flame retardant resin, it has excellent impact resistance, heat resistance, excellent fluidity, and can be formed into a complex large product, and has low dimensional stability because of low molding shrinkage. The present invention relates to an alloy composition of a polycarbonate resin and a polystyrene resin, which can be usefully used in the manufacture of a case, a switch, an adapter, etc., and which has a lower manufacturing cost than a conventional flame retardant resin.

In general, in the manufacture of a new resin, a new polymerization is consumed a lot of development time and cost, so research on the polymer alloy (alloy) has been actively conducted as a way to save the development cost and time .

Polymer alloys have a wide range, including alloys of engineering plastics and general-purpose plastics, alloys of engineering plastics and engineering plastics, and alloys of super engineering plastics and engineering plastics. Of course, it is applied to a wide range of applications from electric, electronic, and sundries.

Among them, particularly for use as components requiring impact resistance, for example, instrument panels, bumpers, radiator grilles, wheel covers, etc. of automobiles, etc. Application to housings, cases, trays and plates has great advantages in terms of functionality and cost, and thus the use of polymer alloys has been expanded.

In particular, in the case of electrical and electronic parts, flame retardancy is indispensable, and the technique of imparting flame retardance as an alloy material is rapidly progressing.

On the other hand, polycarbonate resin and polybutylene terephthalate (hereinafter referred to as PBT) among engineering plastics are applied to automobile bumpers or helmets that require impact resistance. When injection molding, there is a problem in that a sink occurs and shrinkage, and thus its use is limited.

In particular, the two resins have poor compatibility and added a compatibilizer to improve the bar, which is a factor to increase the manufacturing cost.

Alloys of polycarbonate and PBT are disclosed in US Pat. Nos. 3,864,428, 4,034,016, 4,560,722 and 4,654,400, Japanese Patent Publication Nos. 57137347 and 60197757, and European Patent Nos.

Another alloy of polycarbonate resins is an alloy with a polystyrene-based resin composition such as acrylonitrile-butadiene-styrene resin (hereinafter referred to as ABS), for example US Pat. Nos. 3,130,177, 4,218,544. , 4,472,554, 4,522,979, 4,526,926, 4,595,729 and 4,624,869.

Since polycarbonate resin and ABS have a partly miscible property, they have some compatibility. For complete alloy composition, ABS is used for α-methylstyrene, methyl methacrylate, etc. Or a compatibilizer containing a glycidyl group, a maleic anhydride group or an isocyanate group is added.

Such a composition is excellent in mechanical properties such as impact resistance and rigidity, but poor fluidity and poor appearance of the product due to a sink mark or jetting on the product after injection molding having a complicated structure. There is this.

In particular, in this case, when flame retardants are added for use in electrical and electronic parts, such as computer housings, diskettes and CD drive cases, adapters, switches, and cassette cases, the impact resistance is degraded, resulting in cracking of the product. However, there is a limit to the application to the complex structure due to poor fluidity and parts requiring impact strength.

An object of the present invention is to solve the problems in the conventional polycarbonate alloy composition as described above, to impart flame retardancy to be applied to the electrical components of electrical, electronic parts and automotive parts, impact resistance, heat resistance Excellent and fluidity is not only possible to form a complex large parts, but also to provide a thermoplastic flame-retardant resin composition excellent in dimensional stability with a small molding shrinkage.

Thermoplastic flame retardant resin composition of the present invention for achieving the above object is 100 parts by weight of the main component resin consisting of 20 to 80% by weight of polycarbonate resin and 20 to 80% by weight of styrene-acrylonitrile resin, polystyrene containing a functional group It is characterized by consisting of 5 to 15 parts by weight of the resin and 10 to 13 parts by weight of the flame retardant mixture.

The present invention will be described in more detail as follows.

Polycarbonate resins used in the present invention can be prepared by the method as disclosed in US Patent Nos. 2,999,846, 3,028,365, 3,153,008, 3,271,367 and 4,452,968.

In general, polycarbonate is excellent in impact resistance and heat resistance, but has poor flowability during molding, resulting in jetting or flow marks on the product, resulting in poor injection molding, and impact strength depending on the thickness of the product. .

The polycarbonate resin is prepared by reacting an aromatic dihydric phenol with a carbonate precursor, wherein the carbonate precursor is phosgen, haloformate, carbonate ester, and the like.

Polycarbonate resins suitable in the present invention preferably use phosgene as the carbonate precursor, and are preferably prepared by passing the phosgene gas through an activated divalent phenol and an acid acceptor reaction mixture such as pyridine or dimethylaniline.

At this time, the acid acceptor is not diluted or can be diluted with an inert organic solvent, and the inert organic solvent includes methylene chloride, chlorobenzene or 1,2-dichloroethane.

The temperature at which the phosgene reaction proceeds is from 10 to 80 ° C., and the amount of the phosgene depends on the content of the dihydric phenol. One mole of phosgene reacts with one mole of divalent phenol to produce polycarbonate and two moles of hydrochloric acid. Hydrochloric acid is absorbed by the acid receptor.

Another method of preparing an aromatic polycarbonate resin is to phosgenize a suspension of anhydrous alkali salts of aryldiol in a nonaqueous material such as benzene, chlorobenzene or toluene, and in the presence of an inert organic solvent such as methylene chloride or chlorobenzene The reaction is carried out by adding phosgene to the sodium salt slurry of bisphenol A.

In the case of using the carbonate ester as a carbonate precursor in the polycarbonate production reaction, the reaction is performed at a temperature of 120 ° C. or higher for 1 to 15 hours.

Under these conditions, a transesterification reaction occurs between the carbonate ester and the dihydric phenol.

At this time, 1 ppm to 0.5% by weight of a metal catalyst such as lithium, potassium or magnesium is added to the reactor together with phosgene and bisphenol A, and the inert gas such as nitrogen and argon is preferably introduced into the tube while reducing the pressure to 10 to 100 mmHg. It is preferable to proceed with the reaction.

When the oligomeric carbonate formed through such a reaction is heated to a temperature of 120 ° C. or higher under a reduced pressure to 100 mmHg or less for 3 to 5 hours, an aromatic polycarbonate is produced.

Preferred polycarbonate for use in the present invention is a compound represented by the following formula (1), the number average molecular weight is not particularly limited, but is preferably 20,000 to 60,000.

If the number average molecular weight is less than 20,000, the impact resistance of the final composition is poor, and if the number average molecular weight is more than 60,000, the fluidity is lowered.

Formula 1

Wherein n is an integer of 100 to 500.

The content of such polycarbonate is 20 to 80% by weight of the main component resin, if the content is less than 20% by weight, the impact resistance is poor, and if it exceeds 80% by weight, the fluidity is poor.

On the other hand, in the thermoplastic flame retardant resin composition of the present invention, a copolymer of a polycarbonate resin, an aromatic aromatic vinyl compound and a vinyl cyan compound may be prepared by copolymerizing a resin component composed of other vinyl monomers copolymerizable with the polycarbonate resin if necessary. Do.

At this time, the aromatic vinyl compound is styrene, α-methylstyrene, methylstyrene, vinyl xylene, monochlorostyrene, dichlorostyrene, monobromostyrene, dibromostyrene, p - t -butyl styrene, ethyl styrene vinyl naphthalene or o- It is methyl styrene, It can select from these and can use individually or in mixture of 2 or more types.

Most preferably, styrene resin is used among these aromatic vinyl compounds.

The vinyl cyan compound is acrylonitrile or methacrylate, and other vinyl compounds copolymerizable with the vinyl cyan compound are alkyl acrylates such as methyl acrylate, ethyl acrylate and hexyl acrylate, methyl methacrylate and ethyl methacrylate. Methacrylic acid esters such as late or hexyl methacrylate.

Specific examples of the copolymer of such an aromatic vinyl compound and a vinyl cyan compound include acrylonitrile-ethylene-propylene-styrene (AES), styrene-acrylonitrile (SAN), and acrylonitrile-n-butylacrylate-styrene. (AAS).

In the present invention, styrene-acrylonitrile is used among these copolymers, and the styrene-acrylonitrile resin is added at the polymerization temperature of 30 to 150 ° C by adding a monomer, an emulsifier and a polymerization initiator in the presence of a rubbery polymer obtained by emulsion polymerization. Obtained by graft copolymerization under pressure of 100 mmHg or less for 2 to 10 hours.

At this time, the content of the styrene and acrylonitrile monomers is not particularly limited, but is preferably 1: 1 to 2: 1.

In general, styrene-acrylonitrile has a somewhat low impact strength but excellent rigidity and formability, and can compensate for the disadvantages of using polycarbonate resin alone.

The content of styrene-acrylonitrile which plays such a role is 20 to 80% by weight of the main component resin, if the content is less than 20% by weight, it is difficult to improve the fluidity, and when it exceeds 80% by weight, impact resistance and heat resistance are deteriorated. There is.

Meanwhile, in the present invention, a polystyrene-based resin having a functional group is added to improve the compatibility between the polycarbonate resin and the styrene-acrylonitrile, which enhances the compatibility between the polycarbonate resin and the styrene-acrylonitrile resin. It serves to improve impact resistance, heat resistance, flowability and dimensional stability.

The polystyrene resin having a functional group is composed of a conjugated diene rubber, an aromatic vinyl compound, and a compound copolymerizable with an aromatic vinyl compound and a vinyl cyan compound.

In this case, the conjugated diene rubber is a random copolymer of ethylene-propylene or a block copolymer, a copolymer of ethylene and an α-olefin, an ethylene such as ethylene-methacrylate or ethylene-butyl acrylate, and an unsaturated carboxylic acid ester. Copolymers, butadiene, isoprene, random copolymers of styrene-butadiene and block copolymers, acrylonitrile-butadiene copolymers, butadiene-isoprene copolymers, and the like.

Preferred conjugated diene rubbers in the present invention are rubbery polymers containing butadiene, more preferably polybutadiene and styrene-butadiene copolymers, and most preferably polybutadiene is used as the rubbery polymer.

Such conjugated diene rubber is 10 to 40 parts by weight, preferably 15 to 45 parts by weight, in the functional group-containing polystyrene resin content.

If the content of the conjugated diene rubber is less than 15% by weight of the functional group-containing polystyrene resin content, the effect on improving the impact strength in the final composition is insignificant, and if the content exceeds 35% by weight there is a problem in poor fluidity.

Aromatic vinyl compounds constituting the functional group-containing polystyrene resin include styrene, α-methylstyrene, vinyl xylene, monochlorostyrene, dichlorostyrene, dibromostyrene, p - t -butylstyrene, or dimethyl styrene. Since one or a mixture thereof may be selected by selecting from the groups, styrene is preferably added as an aromatic vinyl compound in the present invention.

On the other hand, the content of such an aromatic vinyl compound is 35 to 65 parts by weight in the total functional group-containing polystyrene resin.

And as a compound copolymerizable with the aromatic vinyl compound and the vinyl cyan compound which comprise functional group containing polystyrene resin, methyl acrylate, propyl acrylate, ethyl acrylate, and phenyl acrylate. Acrylic acid alkyl esters such as butyl acrylate, cyclohexyl acrylate or dodecyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, dodecyl methacrylate, It contains a methacrylic acid alkyl ester, such as octyl methacrylate, cyclohexyl methacrylate, or phenyl methacrylate, and it is preferable to contain 15-30 weight part of all functional group containing polystyrene resins.

The functional group-containing polystyrene resin having such a composition is prepared by emulsion polymerization, suspension polymerization or solution polymerization of each monomer in the presence of the conjugated diene rubber.

As a polymerization initiator, a molecular weight regulator, an emulsifier, a dispersant, and a solvent used in the polymerization, conventional ones can be used. Specific examples of suitable preparation methods include the addition of monomers, emulsifiers, and polymerization initiators in the presence of conjugated diene-based rubbers to give a polymerization temperature of 50. A polystyrene-based resin containing functional groups was prepared by mixing a graft copolymer obtained by graft copolymerization at a pressure of 1 to 5 kg / cm 2 for 3 to 15 hours and a styrene polymer obtained by emulsion polymerization or solution polymerization at -100 ° C. can do.

In the thermoplastic flame-retardant resin composition of the present invention, the content of the functional group-containing polystyrene resin is 5 to 15 parts by weight based on 100 parts by weight of the main component resin consisting of the polycarbonate resin and the styrene-acrylonitrile resin. If it is less than 5 parts by weight, the effect of improving the compatibility between the polycarbonate resin and the styrene-acrylonitrile resin is insignificant, and the impact strength is poor. If it exceeds 15 parts by weight, the fluidity and the heat resistance are lowered.

Finally, the thermoplastic flame-retardant resin composition of the present invention contains a flame retardant mixture, which serves to improve the flame retardancy to complement the functional characteristics of the application of the final product.

The flame retardant mixture consists of a flame retardant and an auxiliary flame retardant. The flame retardant is a bromine flame retardant including a glycidyl group, and the auxiliary flame retardant is antimony trioxide.

At this time, the content ratio of the flame retardant and the auxiliary flame retardant is 2 to 4: 1, preferably 3: 1.

The content of such a flame retardant mixture is 10 to 13 parts by weight based on 100 parts by weight of the main component resin, and if the content is less than 10 parts by weight, it does not satisfy the requirements of flame retardant 94V-0 in 1/32 inch specimens recognized by UL94. If it is more than 13 parts by weight, there is a problem that the manufacturing cost is increased. In particular, in the case of the flame retardant when the use of scrap (scrap) during molding the product properties due to its decomposition occurs it is not preferable that the content exceeds 13 parts by weight.

The thermoplastic flame-retardant resin composition of this composition is manufactured using a twin screw extruder. In order to maximize the physical properties of the resin composition, it is kneaded using an extruder having two inlets, and the polycarbonate resin and styrene-acrylonitrile are used at the first inlet. The resin is charged into the secondary inlet, the functional group-containing polystyrene resin, flame retardant and auxiliary flame retardant prepared above.

In particular, since the flame retardant is unstable in heat, it is preferable to inject it into the inlet provided on the nozzle side of the extruder as much as possible.

In addition, in order to prevent thermal decomposition of the composition during melt kneading, it is preferable to minimize the residence time, and a heat stabilizer, a release agent or an antistatic agent may be added within a range that does not violate the object of the present invention.

In the present invention, tris- (2,4-di- t -butylphenyl) -phosphite and N, N' -hexamethylenebis (3,5-di- t -butyl- 4-hydroxy-hydroxycinamide) is added.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited by the Examples.

Examples 1-14 and Comparative Examples 1-12

Next, it was made into a chip state using a twin screw extruder heated to 260 ℃ in the content and composition as shown in Table 1 and dried at 90 ℃ for 5 hours, and then injection molded using a mold for producing test specimens.

Main ingredient (100 parts by weight) Functional group-containing polystyrene resin ⁽¹⁾ (by weight) Flame Retardant Mixture ⁽² ) Polycarbonate (% by weight) Styrene-acrylonitrile (% by weight) A B Example One 80 20 5 - 12 2 80 20 10 - 12 3 80 20 15 - 12 4 80 20 15 - 10 5 60 40 - 5 12 6 60 40 - 10 12 7 60 40 - 15 12 8 60 40 - 15 10 9 40 60 - 10 12 10 40 60 - 15 12 11 60 40 10 - 13 12 60 40 - 10 10 13 20 80 - 10 12 14 20 80 15 - 12 Comparative example One 90 10 - - - 2 80 20 - - - 3 60 40 - - - 4 40 60 - - - 5 20 80 - - - 6 10 90 - - - 7 60 40 2 - 12 8 60 40 - 18 12 9 60 40 10 - 8 10 60 40 - 10 15 11 90 10 10 - 12 12 10 90 - 10 12 (1) Product of GE Corporation (2) Product of DEAD SEA Company: 3: 1 mixture of antimony trioxide A: Styrene-butadiene-methylacrylate B: Styrene-butadiene-ethyl methacrylate

Experimental Example

For the specimens prepared according to Examples 1 to 14 and Comparative Examples 1 to 12, the impact strength, the melt index, the mold shrinkage rate, the flame retardancy, and the heat deformation temperature were measured, and the results are shown in Table 2 below.

At this time, the impact strength was evaluated using an Izod Notched type 1/8 inch specimen according to ASTM D258.

Melt index was evaluated for the amount of flow for 10 minutes at 275 ℃, 5kg / ㎠ load after drying for 5 hours at 90 ℃ in a chip state in accordance with ASTM D1238.

In addition, the mold shrinkage was evaluated in accordance with the ASTM D955 using a disc specimen having a diameter of 100mm in the flow direction shrinkage.

Flame retardancy was evaluated using a 1/32 inch specimen according to the UL94 method, and the heat deflection temperature was evaluated at a load of 264 psi according to ASTM D648.

Impact strength (kgcm / cm) Heat deflection temperature (℃) Melt Index (g / 10min) Mold Shrinkage (%) UL94 Example One 25 125 25.2 0.411 V-0 2 35 121 22.0 0.419 V-0 3 47 116 16.7 0.426 V-0 4 51 115 18.0 0.433 V-0 5 20 120 30.0 0.425 V-0 6 37 114 24.5 0.418 V-0 7 38 110 20.4 0.426 V-0 8 40 109 20.0 0.431 V-0 9 31 111 26.2 0.422 V-0 10 35 107 23.1 0.432 V-0 11 32 115 22.9 0.425 V-0 12 30 112 25.5 0.428 V-0 13 20 106 33.5 0.434 V-0 14 24 103 31.2 0.439 V-0 Comparative example One 22 120 24.0 0.443 HB 2 19 117 32.0 0.442 HB 3 13 112 36.0 0.449 HB 4 10 107 37.5 0.455 HB 5 7 100 39.2 0.459 HB 6 5 89 42.0 0.464 HB 7 11 116 25.3 0.435 V-0 8 55 96 9.0 0.425 V-0 9 31 119 25.3 0.430 V-2 10 26 114 12 0.419 V-0 11 56 120 11 0.421 V-0 12 12 92 38.7 0.451 V-2

In general, flame retardant resins applicable to electric and electronic parts and electrical parts should have impact strength of 20kg · cm / cm or more, heat deformation temperature of 100 ℃ or more, melt index of 15g / 10min or more, and Shrinkage is 0.41 to 0.44% and flame retardancy must meet V-0 in the measurement according to UL49 method.

If the mold shrinkage is greater than 0.44%, it means that the shrinkage is unstable.

Based on such conditions, as in the present invention, a polycarbonate resin and styrene-acrylonitrile are the main components, and a polystyrene-based resin having a functional group is added as a compatibilizer, a flame retardant having a glycidyl group, and trioxide The resin prepared by adding antimony as a flame retardant aid satisfies all conditions of impact strength, heat deformation temperature, melt index, molding stability and flame retardancy.

On the other hand, as in Comparative Examples 1 to 6, a polycarbonate resin and a resin composed of only styrene-acrylonitrile generally have poor physical properties, in particular, impact strength, molding stability, and flame retardancy.

And, as in Comparative Examples 7 to 12, the content range of each composition deviates from that of the present invention. Specifically, when the content of the functional group-containing polystyrene is low, the impact strength is low, and when the amount is excessive, the heat deformation temperature, the melt index, etc. are lowered. do.

In addition, if the content of the flame retardant is small, the flame retardancy falls, and if the content is excessive, the melt index is lowered.

In addition, in the content ratio of the main component resin, the content of the polycarbonate resin is excessive, the melt index drops, and in the small amount, the impact strength, the molding stability, and the flame retardancy are inferior.

As described in detail above, the polycarbonate resin and the styrene-acrylonitrile resin as a main component as in the present invention, in order to increase the compatibility between the two resin conjugated diene rubber, aromatic vinyl compound and aromatic vinyl compound The thermoplastic flame retardant composition prepared by adding a polystyrene-based resin composed of a copolymerizable compound with a vinyl cyan compound, and adding a flame retardant having a glycidyl group and antimony trioxide has a high impact resistance, excellent heat resistance, and excellent fluidity. Since there is no molding problem in the manufacturing of the product and the molding shrinkage rate is small, it is excellent in dimensional stability, which is useful for manufacturing molded articles and large articles of complex structure such as housings, cases, switches, and adapters of electrical and electronic parts, and manufacturing cost is low.

Claims (4)

Thermoplastic flame retardant consisting of 100 parts by weight of the main component consisting of 20 to 80% by weight of polycarbonate resin and 20 to 80% by weight of styrene-acrylonitrile resin, 5 to 15 parts by weight of polystyrene resin containing functional groups and 10 to 13 parts by weight of a flame retardant mixture. Resin composition. According to claim 1, wherein the polystyrene-based resin containing a functional group is composed of a conjugated diene rubber, an aromatic vinyl compound and a compound copolymerizable with an aromatic vinyl compound and a vinyl cyan compound, wherein the copolymerizable with an aromatic vinyl compound and a vinyl cyan compound The compound is a thermoplastic flame retardant resin composition, characterized in that at least one compound selected from alkyl acrylate and alkyl methacrylate. The compound of claim 2, wherein the compound copolymerizable with the aromatic vinyl compound and the vinyl cyan compound is methyl acrylate, propyl acrylate, ethyl acrylate, phenyl acrylate, butyl acrylate, cyclohexyl acrylate, dodecyl acrylate, methyl At least one selected from methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, hexyl methacrylate, dodecyl methacrylate, octyl methacrylate, cyclohexyl methacrylate and phenyl methacrylate Thermoplastic flame retardant resin composition, characterized in that the compound. 2. The thermoplastic flame retardant composition according to claim 1, wherein the flame retardant mixture is a mixture of bromine flame retardant having glycidyl group and antimony trioxide in a ratio of 2 to 4: 1 by weight.