KR0130183B1 - Thermoplastic resin composition - Google Patents

Abstract

A polyester resin having a good impact strength and molding processabilities was prepared. 30-80 Wt.% of polyester resin having a limiting viscosity of 0.4-1.2, 5-30 wt.% of a polyester copolymer resin(I) polymerized by terephthalic acid, butanediol and polytetraglycol, 2-20 wt.% of copolymer(II), 1-10 wt.% of phosphoric compound(III), 5-30 wt.% of a flame retardant having the ratio of decabromodiphenyl oxide and antimony trioxide of 1:1-5:1, 5-50 wt.% of a glass fiber. The surface was treated with silane compound having organic functional group, a length of 2-8 mm and a diameter of 7-15 um, a stabilizer containing tetrakis[methylene-3,5-di-t-butyl-4-hydroxyphenyl)propionate methane and tris(2,4-di-t-butylphenyl)phosphite in the ratio of 1:1, 0.1-5 wt.% of ethylene-bis-stearamide, aluminium stearate as releasing agent, were mixed and extruded at 230-270 deg. C. Where X is 4,5, n and m are 10-50, a is 20-100, R1 is C1-30 aliphatic alkyl, R2 is H or C1-30 aliphatic alkyl, and R1 and R2 is can be identical or different.

Description

Thermoplastic resin composition

1 is a cross-sectional view of a specimen for evaluating the release property of the resin composition of the present invention.

2 is a perspective view of a specimen for evaluating releasability of the resin composition of the present invention.

The present invention relates to a polyester resin composition, and more particularly to a polyester resin composition excellent in impact strength and releasability.

In general, aromatic polyester resins represented by polyalkylene terephthalates such as polyethylene terephthalate and polybutylene terephthalate have excellent mechanical and electrical properties, chemical resistance, and molding processability, so that they can be used alone or as reinforcing materials such as glass fibers and inorganic pillars. B. Various additives have been mixed and modified to be widely used as engineering plastic moldings at home and abroad for fiber, film, electric, electronic and automotive parts. In particular, the flame-retardant polyester resin composition reinforced with glass fibers or flame-retarded by the addition of a flame retardant has excellent mechanical strength and electrical properties, and thus its use has been expanded in recent years as various molded articles.

Recently, as the size of various molded articles becomes smaller and the thickness thereof becomes thinner, moldability is greatly demanded, and thus the use of polyester resins having excellent moldability while maintaining impact resistance is increasing. However, although the aromatic polyester resin represented by such polyalkylene terephthalate has excellent properties described above, its impact resistance is low and its use has been limited to molded articles requiring excellent impact resistance. There have been many limited ways to expand.

In general, polyester resins have been known to use higher fatty acid esters, inorganic materials, metal salts, etc. to improve moldability, but moldability is somewhat improved, but mechanical properties, particularly impact strength, are reduced due to compatibility problems. And the most widely used method for improving the impact resistance of polyalkylene terephthalate is to add an α-olefin polymer or α-olefin copolymer as described in Japanese Patent Office 45-26223, 45-26224 There is a way. This method exhibits relatively excellent physical properties but has a disadvantage in that the compatibility between the polyester and the α-olefin copolymer is poor and thus the physical properties of the molded product are inferior in long-term use.

US Pat. Nos. 4,485,212 and 4,558,096 have methods for adding graft copolymers of styrene and acrylonitrile to the α-olefin copolymer to the polyester. This method improves the impact strength and somewhat improves the compatibility between the polyester resin and the α-olefin copolymer, but is not satisfactory. US Pat. No. 4,445,719 and Japanese Patent Application No. 50-23448 improve the impact resistance and formability by adding butadiene-based graft copolymers to epoxy compounds and epoxy compounds, but have disadvantages of poor heat resistance.

On the other hand, the technology newly applied in the existing resin reforming technology is commercialized in which the acrylic resin is grafted to the α-olefin copolymer in order to solve the poor compatibility between the α-olefin polymer and the α-olefin copolymer and the aromatic polyester resin. The addition of small amounts of the agent has been introduced but is not yet satisfactory.

When adding various additives as described above, the impact resistance is somewhat improved, but

There is still a problem in improving the overall mechanical properties such as mold release.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an aromatic polyester resin represented by a polyalkylene terephthalate having excellent moldability without deteriorating overall mechanical properties while maintaining excellent impact strength.

Hereinafter, the present invention will be described in detail.

The composition of the resin composition of this invention is as follows.

A) 30 to 80 parts by weight of polyester resin

B) 5 to 30 parts by weight of copolymerized polyester resin

C) 2 to 20 parts by weight of copolymer

D) 1 to 10 parts by weight of a phosphorus compound

E) 5 to 30 parts by weight of flame retardant / flame retardant

F) 5 to 50 parts by weight of glass fiber

G) 0.1 to 5 parts by weight of other additives

The aromatic polyester resins represented by the polyalkyl terephthalates used in the present invention include dicarboxylic acids such as terephthalic acid or dialkyl terephthalate or derivatives capable of forming esters thereof, and 1,4-butanediol, 2,3-butanediol, 2, It is a polymer obtained through direct esterification or transesterification reaction mainly based on a diol component such as 4-butanediol, ethylene glycol, propylene glycol, or a derivative capable of ester formation thereof. Such polyester resins include polyethylene terephthalate and polybutylene terebutate, but in the present invention, the intrinsic viscosity (measured in a solvent consisting of 60% phenol and 40% tetrachloroethane in weight ratio at 25 ° C.) is 0.4 to 1.2 good.

If the low molecular polyester resin having an intrinsic viscosity of 0.4 or less is used, the fluidity of the resin composition is excellent, but the compatibility with various additives is poor, resulting in a disadvantage of inferior mechanical properties during injection molding, and a polymer polyester having an intrinsic viscosity of 1.2 or more. When the resin is used, the disadvantages of mechanical properties during extrusion molding can be solved to some extent, but the melt viscosity increases rapidly during processing, so that the dispersibility of the resin composition decreases, and in particular, the injection pressure rises sharply during injection molding, which results in commercialization. The intrinsic viscosity of polyalkylene terephthalate uses the thing of 0.4-1.2.

In the present invention, the copolymerized polyester resin is a copolymer having a structure represented by the following general formula (I) polymerized with terephthalic acid (TPA), butanediol (BG) and polytetraglycol (PRMG), and mixing 5 to 30 parts by weight. Let's do it.

(Where X is an integer of 4 to 5, n and m are integers of 10 to 50 and a is an integer of 20 to 100).

The copolymer mixes 2 to 20 parts by weight of an α-olefin having a structure represented by the following general formula (II) and a glycidyl group-containing olefin copolymer derived from glycidyl ester groups of α and β-unsaturated acids. .

Wherein n is an integer of 2 to 100, X is hydrogen or a hydrocarbon of 1 to 6 carbon atoms, R ₁ is hydrogen or an unsaturated hydrocarbon group, R ₂ is hydrogen or an unsaturated glosidyl group. However, the unsaturated glycidyl group which is excellent in reactivity with the aromatic polyester resin represented by polyalkylene terephthalate is generally used. Wherein the unsaturated glycidyl group has at least one epoxy group and the copolymer is a glycidyl group-containing olefin copolymer obtained by copolymerizing at least one unsaturated glycidyl group and at least one olefin group.

As the olefin group copolymerized with an unsaturated glycidyl group in the present invention, olefins, saturated alcohols, vinyl ethers, and the like are preferable, and these olefin groups may be used alone or as a mixture of two or more different mixtures.

In the present invention, the olefin copolymer obtained by copolymerizing an unsaturated glycidyl group and an olefin group is a copolymer in which an α-olefin copolymer methacrylate, acrylate, vinyl acetate, polystyrene, etc. having a glycidyl group is grafted.

The phosphorus compound has a structure of the following general formula (III) as a phosphate in the form of a monoester or a diester, and it is preferable to use one or two of the following compounds.

(Wherein R ₁ is an aliphatic alkyl group having 1 to 30 carbon atoms, R ₂ is hydrogen or an aliphatic alkyl group having 1 to 30 carbon atoms, and R ₁ and R ₂ may be the same or different from each other.)

That is, methyl dihydrogen phosphate, ethyl dihydrogen phosphate, 2-ethylhexyl dihydrogen phosphate, decyl dihydrogen phosphate, dodecyl dihydrogen phosphate, tridecyl dihydrogen phosphate, stearyl dihydrogen phosphate, etc. Monoesters and dimethylhydrogenphosphate, diisoamylhydrogenphosphate, dioctylhydrogenphosphate, diisooctylhydrogen phosphate, bis (2-ethylhexyl) hydrogen phosphate, dododecylhydrogenphosphate, dididodecylhydrogen Examples thereof include diesters such as phosphate and dioctadecylhydrogen phosphate.

The flame retardant is composed of decabromodiphenyl oxide and antimony trioxide of the following general formula (IV), and the ratio of decabromodiphenyl oxide and antimony trioxide is preferably 1: 1 to 5: 1.

The glass fiber is preferably 2 to 8 mm in length, 7 to 15 μm in diameter, and a surface treated glass fiber of a silane compound having an organic functional group.

In other additives, hindered phenol, phosphite, and thio-based stabilizers are widely used, and may be used alone or in combination. In the present invention, tetrakis [methylene- (3,5- Di-t-butyl-4-hydroxyphenyl) propionate] methane mixed with tris (2,4-di-t-butylphenyl) phosphite in 1: 1 (hereinafter referred to as stabilizer A) As the release agent, ethylene-bis-stearamid (hereinafter referred to as stabilizer B) and aluminum stearate (hereinafter referred to as stabilizer C) may be used. Preferably, stabilizers A, B, and C are 1: 1. It is good to use together at ratio of 1 :. Other dyes, pigments, ultraviolet stabilizers, blowing agents and the like can be mixed arbitrarily.

In preparing the thermoplastic resin composition of the present invention, a single screw extruder or a twin screw extruder may be used after the composition is mixed in a super mixer, and the extrusion temperature may be 230 ° C. to 270 ° C.

Hereinafter, the present invention will be described in detail in Examples and Comparative Examples.

(Example 1)

Intrinsic viscosity (phenol: tetrachloroethane = 6: 4, measured at 25 ° C.) 45 parts by weight of polyester resin (PBT) of 0.9, 10 parts by weight of copolymerized polyester resin, 3 parts by weight of copolymer elastomer, phosphorus 1 part by weight of the compound, 10 parts by weight of flame retardant / flame retardant aid, 30 parts by weight of glass fiber and 1 part by weight of other additives were added and mixed in a super mixer, and then extruded at a temperature of 240 ° C. to 260 ° C. using a JSW twin screw extruder. Got.

In order to measure physical properties, the sample was sufficiently dried at 100 ° C. in a hot air dryer for 4 hours or more, and then injected at a temperature of 220 ° C. to 240 ° C. using an ENGEL injection machine to obtain an injection test specimen for ASTM specification. The specimens thus prepared were measured for impact strength according to ASTM D256, flame resistance according to UL 94, and thermal deformation temperature according to ASTM D648.

The release property was evaluated by using the KISSLER pressure sensor to release the mold release pressure and the release property when forming a cylindrical molded article as shown in FIG. 1 and FIG.

(Examples 2 to 4)

The same resin as in Example 1 was tested by changing the content as shown in Table 1 to evaluate the mechanical properties and releasability in the same manner.

(Comparative Examples 1 to 6)

The mechanical properties and the releasability of the resin composition when some of the additives used in the examples were not used were evaluated. The mechanical properties and the releasability were evaluated in the same manner as in Example 1 while changing the composition according to Table 1.

TABLE 1

TABLE 2

Claims (1)

(Correction) The thermoplastic resin composition, comprised as follows. ① 30 to 80 parts by weight of polyester resin having an intrinsic viscosity of 0.4 to 1.2 ② 5 to 30 parts by weight of a copolyester resin represented by the following general formula (I) polymerized with terephthalic acid, butanediol and polytetra glycol. (Where X is an integer of 4 to 5, n and m are integers of 10 to 50 and a is an integer of 20 to 100). ③ 2 to 20 parts by weight of copolymer represented by the following general formula (II) (Wherein n is an integer from 2 to 100, X is hydrogen or a hydrocarbon having 1 to 6 carbon atoms, R ₁ is hydrogen or an unsaturated hydrocarbon group, R ₂ is hydrogen or an unsaturated glycidyl group.) ④ 1 to 10 parts by weight of phosphorus compound represented by the following general formula (III) (Wherein R ₁ is an aliphatic alkyl group having 1 to 30 carbon atoms, R ₂ is hydrogen or an aliphatic alkyl group having 1 to 30 carbon atoms, and R ₁ and R ₂ may be the same or different from each other.) ⑤ 5 to 30 parts by weight of a flame retardant and flame retardant aid having a ratio of decabromodiphenyl oxide and antimony trioxide represented by the following general formula (IV): 1: 1 to 5: 1 ⑥ 5 to 50 parts by weight of glass fibers with a length of 2 to 8 mm, a diameter of 7 to 15 μm, and a surface-treated silane compound having an organic functional group ⑦ Tetrakis [methylene- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane mixed 1: 1 with tris (2,4-di-t-butylphenyl) phosphite To 5 parts by weight of ethylene-bis-stearamid and aluminum stearate as stabilizer and release agent