KR100199159B1 - Polybutylene terephthalate resin composition - Google Patents

Abstract

100 parts by weight of polybutylene terephthalate; 20-100 parts by weight of acrylonitrile-butadiene-styrene resin; Polybutylene terephthalate resin composition containing 1 to 40 parts by weight of the polyether ester block copolymer is excellent in tensile strength, flexural modulus, impact strength, and chemical resistance.

Description

Polybutylene Terephthalate Resin Composition

The present invention relates to a polybutylene terephthalate resin composition, and more particularly, to a polybutylene terephthalate and an acrylonitrile-butadiene-styrene resin composition having excellent mechanical properties.

In general, polybutylene terephthalate resin has the advantages of fast crystallization rate, good moldability, excellent electrical properties, chemical properties, water resistance, chemical resistance except alkali, and easy flame retardancy and glass fiber reinforcement. The demand is increasing not only in the synthetic fiber and plastic industries, but also in the fields where high reliability is required in the electric and electronic fields, and in the field where plastic materials that are stable in a high temperature and high humidity atmosphere are required in the automotive field.

However, since polybutylene terephthalate is a crystalline polymer, it has a disadvantage of poor impact resistance, high dependence on load, easy bending, and low hydrothermal and alkali resistance.

In order to alleviate such drawbacks, studies have been conducted to alloy polybutylene terephthalate and acrylonitrile-butadiene-styrene resins.

Japanese Laid-Open Patent Publication No. 49-97081 discloses a technique of increasing butadiene content in an acrylonitrile-butadiene-styrene resin and copolymerizing methylmethacrylic acid to improve impact strength and molding shrinkage. However, in the above invention, due to the high content of butadiene, there is a problem in that tensile strength and flexural elasticity of mechanical properties are lowered.

Japanese Laid-Open Patent Publication No. 63-248836 discloses a technique of adding a small amount of an epoxy resin, which is a thermosetting resin, and reinforcing glass fibers to improve tensile, flexural strength, and wear resistance. However, the present invention has a disadvantage in that heat resistance, weather resistance and fluidity are lowered due to the higher amount of acrylonitrile-butadiene-styrene resin than polybutylene terephthalate resin.

European Patent Publication No. 0 383 058 uses acrylonitrile-butadiene-styrene resins having a butadiene content of around 45%, and these have a polymeric glycol terephthalate and isophthalate ester group comprising a polybutylene terephthalate resin. A technique for improving the impact strength by applying it to a polyester resin is disclosed. However, this invention has a problem that the heat distortion temperature is low.

EP 0 310 123 discloses compositions in which trace amounts of aromatic polycarbonate are added with styrene modification. However, such a composition has a disadvantage of low fluidity and chemical resistance by simply increasing the composition of polycarbonate and acrylonitrile-butadiene-styrene resin to increase impact strength and heat distortion temperature.

EP 0 314 188 discloses an ethylene-glycidyl methacryl having a glycidyl group, which is a multi-phase structure termoplastic resin having an epoxy group containing an olefin copolymer and at least one vinyl monomer. A technique of grafting a rate to polystyrene or acrylonitrile-styrene to improve interfacial adhesion to polybutylene terephthalate and acrylonitrile-butadiene-styrene resin, thereby improving heat deformation temperature and impact resistance. However, such a composition has a disadvantage of low flexural modulus.

Therefore, the present inventors carefully examine the above-mentioned disadvantages, but align the polybutylene terephthalate resin and acrylonitrile-butadiene-styrene resin, but have excellent compatibility and impact resistance properties with polybutylene terephthalate. Polybutylene terephthalate / acrylo has excellent processability, chemical resistance, impact resistance at room temperature and low temperature by introducing a polyester block copolymer resin as a third component having excellent simple mixing properties with nitrile-butadiene-styrene resin. Nitrile-butadiene-styrene alloy resins were invented.

The present invention has been made to solve the problems of the prior art as described above, the object of the present invention is polybutylene terephthalate / acrylonitrile-butadiene excellent in mechanical strength, impact strength, flexural modulus, processability, heat resistance, chemical resistance To provide a styrene alloy.

The present invention for achieving the object of the present invention as described above 100 parts by weight of polybutylene terephthalate resin; 10-100 parts by weight of acrylonitrile-butadiene-styrene; It provides a polybutylene terephthalate resin composition comprising; 1 to 40 parts by weight of a polyether ester block copolymer.

The present invention may further include 0.5 to 10 parts by weight of the reactive compatibilizer, and may further include 0 to 10 parts by weight of the butadiene-containing block copolymer.

As in the conventional invention described above, in the alloying of incompatible polymers, a method of using a reactive compatibilizer having excellent compatibility for introducing a reactive reactor to reduce interfacial tension between two resins and enhancing interfacial adhesion is widely used. It is used.

The inventors also use compatibilizers to increase the compatibility and interfacial adhesion of polybutylene terephthalate and acrylonitrile-butadiene-styrene resins, as well as control the morphology and polyether esters as mentioned above. By adding block copolymer resin, the crystalline polyester component in this polyether ester block copolymer resin chain comprises a hard segment. These are excellent in compatibility with polybutylene terephthalate. In addition, the aliphatic polyether polyol component is covalently bonded in one molecule as a soft segment, and is excellent in compatibility with acrylonitrile-butadiene-styrene resin having a high proportion of amorphous parts. Accordingly, the present invention is a resin composition excellent in impact resistance and moldability at room temperature and low temperature.

Typically, compatibilizers are used to prepare incompatible alloy resins, which are of two types, reactive and non-reactive. In the case of non-reactive, since it does not react with the base polymer in the compatibilizer composition, it is possible to increase the interfacial adhesion between the two substances by introducing a reactive end group of any polymer into the polymer chain. In addition, the reactive compatibilizer is excellent in the use of a small amount, but it is characterized by reducing the molecular weight of the resin composition according to the reaction to reduce the physical properties, the inventors of the two forms of compatibilizer using the reactive compatibilizer The resin having the purpose of excellent mechanical properties, heat resistance, processability and chemical resistance was prepared by blocking the molecular weight decrease of and increasing compatibility and interfacial adhesion.

In this invention, content of acrylonitrile- butadiene- styrene is 20-100 weight part with respect to 100 weight part of polybutylene terephthalate resins, More preferably, 30-70 weight part is preferable. If the content of acrylonitrile-butadiene-styrene is less than 20 parts by weight, the impact strength is poor, and if the content of acrylonitrile-butadiene-styrene is more than 100 parts by weight, the flexural modulus and the chemical resistance are poor.

In this case, the content of acrylonitrile, butadiene, and styrene in the acrylonitrile-butadiene-styrene resin is preferably acrylonitrile: butadiene: styrene = 15-50 wt%: 13-25 wt%: 45-63 wt% .

In the present invention, the polyether ester block copolymer resin component serves to improve the impact resistance, which is the biggest disadvantage of the polybutylene terephthalate resin composition. In particular, the effect of improving the impact resistance at low temperatures is excellent. Accordingly, even if the amount of acrylonitrile-butadiene-styrene resin is reduced, the impact resistance can be improved by the addition of the polyether ester block copolymer resin. Such reduction in the amount of acrylonitrile-butadiene-styrene resin shows an effect of improving chemical resistance of the polybutylene terephthalate resin.

In addition, in the present invention, the polyether ester block copolymer serves as an impact agent and at the same time a compatibilizer. That is, the polyether ester block copolymer resin has excellent compatibility with polybutylene terephthalate, and is also compatible with acrylonitrile-butadiene-styrene, so that the polybutylene terephthalate and acryl It acts as a compatibilizer for ronitrile-butadiene-styrene.

The polyether ester block copolymer is composed of a block copolymer of a hard segment represented by the following structural formula (II) and a soft segment represented by the structural formula (III).

In the above formula (III), R is aliphatic dicarboxylic acid such as tezephthalic acid or its lower alkyl ester cargo alone, or aromatic dicarboxylic acid such as isophthalic acid, old phthalic acid, naphthalenedicarboxylic acid, or adipic acid, sebacic acid, dimer acid or the like. A mixture with aliphatic dicarboxylic acid such as main acid or cyclohexanedicarboxylic acid may be used, and as D, an aliphatic glycol component having 2 to 8 carbon atoms is used, and mainly 1,4-butanediol is used, and ethylene glycol, 1, 2- or 1, 3-propylene glycol, 1, 5- pentanedi 1, 6- hexanediol, 1, 4- cyclohexane dimethane, etc. can be mixed. R in the formula (III) is the same as in the formula (II), G is a polyalkylene oxide glycol component having a molecular weight of 300 to 6000 is used, mainly poly (tetramethylene oxide) glycol is used, Polyethylene glycol or polypropylene glycol may be used here alone or in a mixed form.

In the present invention, a compatibilizer or a reactive compatibilizer such as butadiene-containing block copolymer can be further added for uniform physical properties and quality control of the resin composition.

The butadiene-containing block copolymer is an acrylic ester of an acrylic or alkyl ester monomer and one or more monomers selected from styrene, alpha (α) -methylstyrene, vinyltoluene, and halogen substituted styrene as aromatic vinyl monomers in the presence of polybutadiene latex. , Methacrylic acid esters and the like can be prepared by suspension or emulsion polymerization.

It is preferable that these butadiene containing block copolymers add 0-10 weight part with respect to the whole resin composition. When the addition amount of the butadiene-containing block copolymer exceeds 10 parts by weight, there is a disadvantage in that the heat resistance and processability of the final resin composition are lowered.

The reactive compatibilizer described above has an epoxy group capable of reacting with polybutylene terephthalate in the acrylic main chain, and polymethyl methacrylate compatible with acrylonitrile-butadiene-styrene resin is present in the side chain. It is represented by general formula (IV) and starts with macromolecular monomer to make graft copolymer.

In the formula (IV), X is polystyrene, polymethylmethacrylate, styrene-acrylonitrile, and the like, and the number average molecular weight of the macromolecule is 300 to 2200. R ₀ is an alkyl group, a phenyl group, the alkyl group having a value of 1 to 12 carbon atoms, butyl glycidyl ether, heptyl glycidyl ether, octyl glycidyl ether, aryl glycidyl ether, phenyl glycidyl ether, cre Sil glycidyl ether, (meth-ethenyl) phenyl glycidyl ether, (meth-isobutenyl) phenyl glycidyl ether, (meth-isopropenyl) phenyl glycidyl ether, and the like.

It is preferable to add 0.5-10 weight part of these reactive compatibilizers with respect to the whole resin composition. If the amount of the reactive compatibilizer is less than 0.5 parts by weight, it is difficult to expect the effect of improving the physical properties by the addition of the compatibilizer, when the amount exceeds 10 parts by weight to obtain a reduction in processability due to the reaction and a proportional property improvement effect on the input amount It is not economical because production costs rise.

The reactive compatibilizer comprises 20 parts by weight of macromolecular monomer and 40 parts by weight of glycidyl acrylate monomer such as formula (V), 5 parts by weight of acrylic acid, ethylene, propylene, 1-butene and substitution with alpha-olefin monomer or One or more of monomers such as unsubstituted styrene may be selected and used. 35 parts by weight of 0.5 parts by weight of the reaction initiator 2-2'-azobisisobutylonitrile is added to 100 parts by weight of tetrahydrane, and 60 parts by weight of It can be made by reacting for 24 hours at ℃.

(Wherein R 'is hydrogen or a hydrocarbon group of 1 to 5 carbon atoms, R is a phenyl group including an alkyl group or a hydrocarbon group of 1 to 3 carbon atoms, sulfonyl group, carboxyl group, sulfur, carbonyl group, etc.)

Representative methods for producing the polybutylene terephthalate resin composition of the present invention described above are as follows.

[I] Production of Polybutylene Terephthalate]

Into a stainless steel reaction vessel equipped with a stirrer, an additive such as an acid component, a glycol component, a catalyst, and various stabilizers are added, and the low molecular weight ester condensation by-products are removed out of the system while maintaining the temperature of the reaction tube at 200 to 230 ° C. The reaction is proceeded, and the conversion rate of the ester reaction is terminated based on the point at which 95% or more of the theoretical flow rate of the low molecular weight ester by-product is usually flowed out, and when the ester reaction is terminated, the temperature in the tube is increased to 250 to 260 ° C. While reducing the pressure in the tube to 1mmHg or less to induce polycondensation of the polyester. Then, when the condensation polymerization proceeds, when the pressure in the tube becomes 10 mmHg or less, the reaction proceeds for 2 to 3 hours, the reaction is terminated by adding nitrogen, and the reaction product is discharged in the tube to discharge the polyester base resin of the following formula (I) desired in the present invention. Got. The acid component which can be used here can mainly use terephthalic acid or a lower alkyl ester compound alone, or a small amount of isophthalic acid, orthophthalic acid terephthal or aliphatic dicarboxylic acid, or a mixture with these lower alkyl ester compounds, and as a glycol component, a carbon number is mainly Four butylene glycols alone or mixtures with other small amounts of ethylene glycol, 1,2- or 1,3-propylene glycol, 1,6-hexanediol, 1,4-cyclohexane dimethanol, and the like can be used. It is common practice to use organic titanium compounds such as tetrabutyl titanate, tetraisopropyl titanate and the like, and other organic tin compounds alone or a mixture of these and organic titanium compounds may be used, and alkali metals or antimony thereof may be used. Oxides, acetates and the like can also be used. And when using an organic titanium compound, magnesium acetate can also be used as a cocatalyst. In addition to these main components and catalysts, it is also possible to use subsidiary materials such as antioxidants, antistatic agents and various additives. Meanwhile, the viscosity of the polybutylene terephthalate used in the present invention may be one having an intrinsic viscosity of 0.7 to 1.3 (solvent: orthochlorophenol, 30 ° C.). There is a disadvantage in that the liquidity is poor.

In the formula (I), n represents an integer of 50 to 300.

[Preparation of (II) Acrylonitrile-Butadiene-Styrene Resin]

Synthesized acrylonitrile-styrene as a graft or block copolymer by mixing butadiene-based synthetic rubber and acrylonitrile-butadiene-styrene (hereinafter referred to as SAN resin) copolymer or emulsion polymerization in the polybutadiene backbone. In the present invention, an intrinsic viscosity of 0.4 to 0.9 (solvent: methyl-ethyl-ketone, 30 ° C.) was used. If the molecular weight is less than 0.4, it is difficult to form co-continuous with autopolybutylene terephthalate, so that it is dispersed. This difficulty is difficult to expect good adhesion, and if it is 0.9 or more, there is a disadvantage that the fluidity of the composition is lowered, which is not good. Among acrylonitrile-butadiene-styrene resins, 13 to 25 parts by weight of polybutadiene latex, 15 to 30 parts by weight of acrylonitrile monomers, and 45 to 65 parts by weight of styrene monomers are preferred. The higher the butadiene content, the better the impact resistance but the flexural and tensile strength Is lowered.

[(III) Preparation of Polyether Ester Block Copolymer Resin]

Polyether ester block copolymer resin is a low molecular weight oligomer through the esterification or transesterification reaction in the same manner as the polybutylene terephthalate production method, and a high molecular weight product through a condensation reaction at a high vacuum of 1mmHg or less The polyether ester block copolymer resin prepared in this way may be prepared by removing moisture through drying, and then, a product may be manufactured. However, the polyether ester block copolymer resin may be used as it is. It is also effective when mixed with an agent, an antistatic agent, a pigment and other additives during the polymerization process or other secondary processing, and improves the molecular weight by reacting with the end groups or functional groups of the polyester compound to improve the physical properties of the final resin. Modification techniques to generate small-scale modifications of the molecular structure After the reaction or during the reaction of the additive, the method of simple mixing, or reaction by mixing the hot melt is also very effective. In addition, the hard and soft segments exhibit various flexibility depending on the ratio, but the physical level that can be used in the present invention is not particularly limited, but the soft segment is about 20 to 80% by weight relative to the total weight of the polyether ester block copolymer resin. In order to supplement the impact resistance of the final resin composition, a high content of the polyether ester block copolymer resin having a low soft segment content is added, and a low content of the polyether ester block copolymer resin having a high soft segment content is added thereto. The physical properties exhibit similar effects.

[Production of (IV) Resin Composition]

The resin composition according to the present invention may be prepared using a twin screw extruder, and is kneaded using an extruder having two inlets to maximize the mechanical properties of the resin composition, and the primary inlets are polybutylene terephthalate and acrylonitrile. Butadiene-styrene and polyether ester block copolymers are added, and reactive compatibilizers and butadiene-containing block copolymers are preferably added to the secondary inlet. In addition, it is desirable to minimize residence time in order to prevent thermal decomposition of the composition during melt kneading, and it is necessary to optimally adjust the screw rotation speed to appropriately control the butadiene domain size affecting the destruction of molecules of the composition and impact resistance. The size of 0.2-0.8 micrometers is good.

In addition, additives such as fibrous or inorganic fillers, heat stabilizers, lubricants, flame retardants, antistatic agents, and plasticizers can be suitably blended as necessary within the range of not impairing the object according to the present invention, and in the resin composition of the present invention, Tris- (2,4-di-tert-butylphenyl) -phosphite and N-N'-hexamethylene bis (3,5-di-tert-butyl-4-hydroxy-) Iganox B1171 (trade name, manufacturer: CIGAIGI), which is a one-to-one mixture of hydrocinamide, may be used.

Hereinafter, preferred examples and comparative examples of the present invention are described. However, the following examples are merely examples of the present invention and the present invention is not limited to the following examples.

[Examples 1-5 and Comparative Examples 1-6]

Acrylonitrile-butadiene-styrene and a polyether ester block copolymer were added to 100 parts by weight of polybutylene terephthalate resin in the primary raw material inlet by using a twin-screw compressor heated to 240 ° C. A styrene-butadiene-styrene copolymer, a reactive compatibilizer and a butadiene-containing block copolymer, was also introduced into the secondary inlet located in the middle of the cylinder in the composition shown in Table 1 to prepare a resin composition through a hot melt kneading process, and then to 110 ° C. After drying using a dehumidifying dryer for 5 hours at was prepared by using a screw injection machine heated to 240 ℃ to measure the physical properties.

In Table 1, the types of reactive compatibilizers A, B, and C have the structure of general formula (IV), and the substituents represent reactive compatibilizers as shown in Table 2.

The physical properties of the resin composition specimens prepared according to the above Examples and Comparative Examples were measured by the following method, and the results are shown in Table 3.

(1) Flexural modulus:

It was measured according to ASTM D 790 and the unit is kg / cm 2.

(2) Impact strength

In accordance with ASTM D 256, measured at room temperature (23 ℃) and low temperature (-30 ℃) by the Izod notch method, the unit is kg ㎝ / ㎝.

(3) Chemical resistance:

After immersion in carbon tetrachloride, 10% ammonia water and gasoline at room temperature for 10 days, respectively, the retention rate of tensile strength was measured based on the tensile strength evaluation criteria of the lower phase.

(4) Melt Index:

According to ASTM D 1238, the amount of the resin composition was flowed in a chip state at 240 ° C. under a 2.16 kg load for 10 minutes, and the unit was g / 10 min.

(5) Heat deflection temperature:

It measured at 264 psi (18.6 kg / cm <2>) according to ASTM D 648, and a unit is ° C.

(6) Tensile strength

Measured according to ASTM D 638, the unit is kg / cm 2,

As can be seen in Table 3, the resin composition according to the embodiment of the present invention is superior in tensile strength, flexural modulus, impact strength, and chemical resistance than the resin composition prepared according to the comparative example.

Claims (3)

100 parts by weight of polybutylene terephthalate; 20-100 parts by weight of acrylonitrile-butadiene-styrene resin; And 1-40 parts by weight of a polyether ester block copolymer. The polybutylene terephthalate resin composition according to claim 1, further comprising 0.5-10 parts by weight of a reactive compatibilizer represented by the following general formula (I). (In Formula (I), X is selected from the group consisting of polystyrene, polymethylmethacrylate, styrene-acrylonitrile copolymer, and R ₀ is selected from the group consisting of an alkyl group having 1 to 12 carbon atoms and a phenyl group). The polybutylene terephthalate resin composition according to any one of claims 1 to 3, further comprising 0-10 parts by weight of butadiene-containing block copolymer.