JPH04304258A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide a thermoplastic resin composition improved in compatibility of polyester with polyethylene, lowered in density and excellent in impact resistance, tensile elongation, mechanical strengths, etc. CONSTITUTION:A thermoplastic resin composition comprising 100 pts.wt. total of 50-95wt.% polyester, 1-49wt.% polyethylene and 1-30wt.% epoxy ethylene copolymer and 1-15 pts.wt. modified styrene block copolymer.

Description

Description [0001] [Industrial Application Field] The present invention relates to a thermoplastic resin composition containing polyester and polyethylene, and in particular, the polyester and polyethylene are well compatible, and the composition has excellent impact resistance, The present invention relates to a thermoplastic resin composition that is lightweight and has excellent tensile elongation and mechanical strength. [Prior Art and Problems to be Solved by the Invention] Polyester is used in various electrical components such as automobiles and home appliances because of its excellent insulation, mechanical strength, impact resistance, and heat resistance. However, since it has a high specific gravity, it becomes particularly heavy when used for large objects. On the other hand, polyethylene has excellent moldability, chemical resistance, water resistance, etc., but has the disadvantage of being inferior in rigidity, heat resistance, etc. Therefore, attempts have been made to alleviate the drawbacks of both polyesters and polyethylene to create a well-balanced resin. However, since polyethylene and polyester do not have sufficient compatibility, there is a problem in that impact resistance and surface releasability deteriorate when simply blended. [0003] Therefore, in order to improve the compatibility between the two, it has been considered to make polyester and polyethylene compatible by adding an epoxy group-containing ethylene copolymer such as an ethylene-glycidyl methacrylate copolymer. However, compositions containing epoxy group-containing ethylene copolymers have lower mechanical strengths such as rigidity and tensile elongation, and furthermore, polyethylene and polyester are not sufficiently compatible. There is a problem that impact resistance is not sufficient. [0005] Conventionally, mixing polyethylene and polyester improves mechanical strength, insulation, impact resistance,
Physical properties such as moldability, chemical resistance, water resistance, and surface peeling resistance are significantly reduced, making it difficult to obtain a composition that satisfies all properties, that is, a well-balanced resin. Therefore, the object of the present invention is to achieve good compatibility between polyester and polyethylene, thereby improving impact resistance and
The object of the present invention is to provide a lightweight thermoplastic resin composition that has excellent tensile elongation, mechanical strength, etc. [Means for Solving the Problem] As a result of intensive studies in view of the above object, the present inventors have determined that an epoxy group-containing ethylene copolymer and a predetermined amount of an ethylene copolymer are used as a compatibilizer for polyester and polyethylene. The composition containing the modified styrenic block copolymer has good compatibility between polyester and polyethylene, and has excellent mechanical strength such as impact resistance and tensile elongation, and moldability. This heading led to the idea of the present invention. That is, the thermoplastic resin composition of the present invention comprises (a) 50 to 95% by weight of polyester, and (b)
1 to 49% by weight of polyethylene, (c) 1 to 30% by weight of epoxy group-containing ethylene copolymer, and (a)
+ (b) + (c) for a total of 100 parts by weight (
d) 1 to 15 parts by weight of a modified styrenic block copolymer. The present invention will be explained in detail below. In the present invention, (a) polyester is generally a thermoplastic resin consisting of a saturated dicarboxylic acid and a saturated dihydric alcohol, such as polyethylene terephthalate, polypropylene terephthalate, polytetramethylene terephthalate (polybutylene terephthalate), polyhexamethylene terephthalate, polycyclohexane. Examples include -1,4-dimethylol terephthalate and polyneopentyl terephthalate. Among these, polyethylene terephthalate and polybutylene terephthalate are particularly preferred, and polybutylene terephthalate is particularly preferred. The polyester preferably has an intrinsic viscosity [η] of 0.30 to 1.8 and a concentration of terminal carboxyl groups of 10 to 200 m equivalent/kg. Here, the intrinsic viscosity [η] (dl/g) is determined from the solution viscosity measured at 25° C. in an o-chlorophenol solvent. In the case of polybutylene terephthalate, the intrinsic viscosity [η] is preferably 0.30 to 1.8, and the terminal carboxyl group concentration is preferably 10 to 200 m equivalent/kg. In this case as well, the terephthalic acid component is an alkyl group,
It may be substituted with a halogen group or the like, and the glycol component may contain up to about 50% by weight of other glycols in addition to 1,4-butylene glycol, such as ethylene glycol, propylene glycol, hexamethylene glycol, etc. good. In the case of polyethylene terephthalate, it is preferable that the intrinsic viscosity [η] is 0.30 to 1.2 and the terminal carboxyl group concentration is 10 to 200 m equivalent/kg. The terephthalic acid component in polyethylene terephthalate may be substituted with an alkyl group, a halogen group, etc., and the glycol component may contain up to about 50% by weight of other glycols in addition to ethylene glycol, such as 1,4-butylene. It may contain glycol, propylene glycol, hexamethylene glycol, etc. In the present invention, (b) polyethylene is
A polymer compound whose constituent unit is ethylene, with a melt index (MI 190 °C, 2.16 kg load)
0.01-50g/10 min, density (ASTM D1
505) is 0.955 to 0.885 g/cm3, and may be copolymerized with other α-olefins in an amount of up to 10% by weight. Examples of such polyethylene include low-density polyethylene, linear low-density polyethylene, and high-density polyethylene, but high-density polyethylene is particularly preferred because it has high rigidity and the resulting composition has a good balance. In the present invention, the high density polyethylene has a density of 0.935 g/cm3 or more and a melt index (MI 190 °C, 2.16 k
g load) is preferably 0.1 to 10 g/10 minutes. In the present invention, (c) the epoxy group-containing ethylene copolymer refers to (i) an ethylenically unsaturated compound, and (ii) an unsaturated group copolymerizable with the ethylenically unsaturated compound and an epoxy group. It is a copolymer with an unsaturated epoxy compound having each of the following. The above (i) ethylenically unsaturated compounds include olefins, vinyl esters of saturated carboxylic acids having 2 to 6 carbon atoms, and esters of saturated alcohol components having 1 to 8 carbon atoms and acrylic acid or methacrylic acid. esters, maleic acid esters, methacrylic acid esters, fumaric acid esters, vinyl halides, styrenes, nitriles, vinyl ethers, acrylamides, and the like. Specifically, ethylene, propylene, butene-1, vinyl acetate, methyl acrylate, ethyl acrylate, methyl methacrylate, dimethyl maleate, diethyl fumarate, vinyl chloride, vinylidene chloride, styrene, acrylonitrile, isobutyl Examples include vinyl ether and acrylamide, and among these, ethylene is particularly preferred. Further, examples of unsaturated epoxy compounds each having an unsaturated group and an epoxy group copolymerizable with such an ethylenically unsaturated compound include the following general formula (1).
) unsaturated glycidyl esters as represented by the following, unsaturated glycidyl ethers as represented by the following general formula (2), etc. [Formula 1] (wherein, R has 2 to 2 carbon atoms and has an ethylenically unsaturated bond)
18 hydrocarbon groups. ) [Chemical formula 2] (In the formula, R has 2 to 2 carbon atoms and has an ethylenically unsaturated bond.)
18 hydrocarbon groups, and X is -CH2-O- or [Formula 3]. ) Specific examples of such unsaturated glycidyl esters include glycidyl acrylate, glycidyl methacrylate, itaconic acid glycidyl esters, etc., and examples of unsaturated glycidyl ethers include allyl glycidyl ether, 2- Examples include methylallyl glycidyl ether and styrene-p-glycidyl ether. Glycidyl methacrylate is particularly preferred. The amount of copolymerization of the unsaturated epoxy compound as described above is such that the total amount of ethylene and the unsaturated epoxy compound is 1
00% by weight is about 0.1 to 30% by weight,
Particularly preferred is 5 to 20% by weight. Further, such a copolymer of an unsaturated epoxy compound and ethylene is a random copolymer in which an unsaturated epoxy compound is introduced into the main chain of ethylene, or a copolymer in which an unsaturated epoxy compound is introduced into the main chain of ethylene, or a copolymer in which an unsaturated epoxy compound is introduced as a side chain of the ethylene copolymer. Any graft copolymer into which a saturated epoxy compound is introduced may be used. In the case of a random copolymer, ethylene and an unsaturated epoxy compound may be radically polymerized at normal pressure. In the case of a graft copolymer, it can be produced by either a solution method or a melt-kneading method. In the melt-kneading method, ethylene, an unsaturated epoxy compound, and a catalyst are put into an extruder or twin-screw kneader, etc., and 1
The mixture is heated to a temperature of 50 to 300°C and kneaded while melting. In the solution method, the starting material is dissolved in an organic solvent such as xylene, and the solution is stirred at a temperature of 80 to 140°C. In either case, ordinary radical polymerization catalysts can be used as catalysts, such as benzoyl peroxide, lauroyl peroxide, ditertiary butyl peroxide, acetyl peroxide, tertiary butyl peroxybenzoic acid, dicumyl peroxide, Peroxybenzoic acid, peroxyacetic acid, tert-butyl peroxypivalate, 2
, 5-dimethyl-2,5-ditertiarybutylperoxyhexine and other peroxides, and azobisisobutyronitrile and other diazo compounds are preferred. The weight average molecular weight of such a copolymer of ethylene and an unsaturated epoxy compound (c) is usually 8.0.
00 to 500,000, and its melt flow rate (MFR, 230 °C, 2.16 kg load)
is 0.1 to 100 g/10 minutes. In the present invention, the modified styrenic block copolymer (d) is one modified with an unsaturated carboxylic acid or its anhydride, or an epoxy group-containing monomer. The above-mentioned styrenic block copolymer is a copolymer consisting of a polystyrene block and a polyolefin block, or a hydrogenated product thereof. Examples of such styrene block copolymers include styrene-isoprene-styrene block copolymers (SIS, including styrene-isoprene block copolymers), styrene-butadiene-styrene block copolymers (SBS, (including styrene-butadiene block copolymer), styrene-hydrogenated isoprene-styrene block copolymer (styrene-ethylene-propylene-styrene block copolymer: SEPS), styrene-
Hydrogenated butadiene-styrene block copolymer (styrene-ethylene-butylene-styrene block copolymer:
SEBS), etc. Among the above styrene block copolymers, styrene-hydrogenated isoprene-styrene block copolymers (SEPS) and styrene-hydrogenated butadiene-styrene block copolymers (SEBS) are preferred from the viewpoint of weather resistance. . The above styrene-hydrogenated isoprene-styrene block copolymer (SEPS) has the following general formula (3).
It is expressed by (S-EP)n-Sm
...(3) (wherein, S represents the polystyrene moiety, EP
represent hydrogenated polyisoprene moieties (ethylene/propylene moieties), n is an integer from 1 to 20, and m is 0.
Or 1. ) The above-mentioned styrene-hydrogenated isoprene-styrene block copolymer includes two block type ones (SEP when n=1 and m=0), three
Examples include block type (when n=1 and m=1) and multi-block type (when n=2 to 20), and any of them can be used in the present invention. Particularly preferred are three-block type and multi-block type. The above-mentioned styrene-hydrogenated isoprene-styrene block copolymer is prepared by subjecting the styrene-isoprene-styrene block copolymer to 25 to By hydrogenating at a temperature of 175°C, only the isoprene portion was selectively hydrogenated, forming a structure corresponding to an ethylene-propylene copolymer. [0031] In the above styrene-hydrogenated isoprene-styrene block copolymer, it is not necessary that all of the isoprene portion is hydrogenated, as long as 5% or more is hydrogenated. The preferred hydrogenation ratio is 50% or more, more preferably 80% or more. The styrene-hydrogenated isoprene-styrene block copolymer has been explained above, but the styrene-hydrogenated isoprene-styrene block copolymer
Hydrogenated butadiene-styrene block copolymer (SEB
S) is the same as in the above explanation except that isoprene is replaced with butadiene. In the present invention, the content of styrene moieties in such a styrenic block copolymer is 5 to 65%.
It is about 13% to 50% by weight, preferably 13 to 50% by weight. Note that in the styrenic block copolymer, the polystyrene portion is not limited to one consisting only of styrene, but may be one consisting of substituted styrene such as methylstyrene. The weight average molecular weight of such a styrenic block copolymer is 2×10
4 to 50×104 is preferable, particularly 5×104 to
35×104 is preferred. If the weight average molecular weight is less than 2 x 104, the melt viscosity will be too low, while if it exceeds 50 x 104, the melt viscosity will become too high and moldability will deteriorate, which is not preferred. Examples of the unsaturated carboxylic acid or anhydride thereof that modify the styrenic block copolymer include monocarboxylic acids such as acrylic acid and methacrylic acid, maleic acid, fumaric acid, itaconic acid, and endomethylenetetrahydro. Dicarboxylic acids such as phthalic acid, maleic anhydride,
Itaconic anhydride, endo-bicyclo-[2,2,1]
Dicarboxylic acid anhydrides such as -5-heptene-2,3-dicarboxylic anhydride (himic anhydride) are exemplified, and dicarboxylic acids and their anhydrides are particularly preferred. On the other hand, examples of the epoxy group-containing monomer for modification include glycidyl methacrylate and glycidyl acrylate. Furthermore, the following general formula (4): [Formula 4] (wherein, R is H or an alkyl group having 1 to 6 carbon atoms,
Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms and having at least one glycidyloxy group, and n is 1 to 4.
represents an integer. ) Glycidyl compounds represented by the following can also be used as modifying monomers. Preferred glycidyl compounds include those represented by the following general formula (5). [Formula 5] (In the formula, R is H or an alkyl group having 1 to 6 carbon atoms.) Such a glycidyl compound can be prepared, for example, by the following method shown in JP-A-60-130580. It can be manufactured by First, at least one phenolic hydroxyl group
By condensing an aromatic hydrocarbon having 1 or more with N-methylol acrylamide, N-methylol methacrylamide, or an alkyl ether derivative of N-methylol methacrylamide (hereinafter referred to as N-methylol acrylamides) using an acid catalyst. , the following general formula (6) [Chemical formula 6] (wherein, R is H or an alkyl group having 1 to 6 carbon atoms,
Ar' has at least one hydroxyl group and has 6 carbon atoms
~20 aromatic hydrocarbon groups, and n represents an integer of 1 to 4. ) is produced. The aromatic hydrocarbon having at least one phenolic hydroxyl group is not particularly limited;
For example, phenol, o-cresol, m-cresol,
p-cresol, 2,6-xylenol, 2,4-xylenol, o-chlorophenol, m-chlorophenol, p-chlorophenol, o-phenylphenol,
Phenolic compounds such as 2,6-diphenylphenol, polyphenolic compounds such as hydroquinone, catechol, and phloroglucinol, polycyclic hydroxy compounds such as 1-naphthol, 2-naphthol, and 9-hydroxyanthracene, 2,2-bis (4-hydroxyphenyl)propane (bisphenol-A), bis(4-
Examples include bisphenols such as hydroxyphenyl and methane. Next, by glycidylating the hydroxyl group of the compound represented by the above general formula (6), the general formula (4) is obtained.
A glycidyl compound represented by can be obtained. For this glycidylation, it is preferable to conduct an addition reaction between the compound represented by the general formula (6) and epihalohydrin, and then perform dehydrohalogenation using a caustic alkali. The addition reaction with epihalohydrin is carried out using a phase transfer catalyst. The epihalohydrin mentioned above is
Epichlorohydrin, epibromohydrin, epiiodohydrin, etc. can be used. Examples of phase transfer catalysts include quaternary ammonium salts such as tetrabutylammonium bromide, trioctylmethylammonium chloride, benzyltriethylammonium chloride, and quaternary phosphonium salts such as tetraphenylphosphonium chloride and triphenylmethylphosphonium chloride. Salt etc. can be used. The amount of the phase transfer catalyst used is determined by the general formula (6
) as 100 mol%, 0.0
It is preferably used in a range of 1 to 100 mol%. A particularly preferred amount of phase transfer catalyst used is 0.05 to 10 mol%. In addition, the reaction time and reaction temperature are 50 to 120
5 minutes to 2 hours at ℃, more preferably 80 to 110 ℃
It takes 10 to 30 minutes. Subsequently, dehydrohalogenation is carried out using caustic alkali. The above caustic alkali includes caustic soda,
Caustic potash, lithium hydroxide, etc. can be used. These can be used as solids or as aqueous solutions. Further, as a catalyst for dehydrohalogenation, the same one as the above-mentioned phase transfer catalyst can be used. Catalysts other than the above phase transfer catalysts include crown ethers,
Examples include ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, and the like. The amount of the caustic alkali used is determined by the general formula (6
) It is preferred to use equimolar amounts with respect to the compound represented by. More preferably, 1.1 to 1.5 times the molar amount is used. In addition, the reaction time and reaction temperature are 20 to 90°C for 10 minutes to 30 minutes.
The time is preferably 30 minutes to 2 hours at 40 to 70°C. Modification of the styrenic block copolymer with such an unsaturated carboxylic acid or its anhydride, or an epoxy group-containing monomer is carried out by graft polymerization or random polymerization of the above-mentioned modifying monomer onto the styrenic block copolymer. This can be done depending on the situation. In the case of graft polymerization, first, a styrenic block copolymer, an unsaturated carboxylic acid or its anhydride for modification, or an epoxy group-containing monomer and, if necessary, a catalyst are mixed in an extruder or twin-screw kneader. etc., 150
The mixture is kneaded while melting at about 300°C, preferably about 180 to 250°C. At this time, the amount of unsaturated carboxylic acid or its anhydride, or epoxy group-containing monomer added is about 0.1 to 20 parts by weight, preferably 0.5 to 1 part by weight, based on 100 parts by weight of the styrenic block copolymer.
It is about 0 parts by weight. [0050] As the catalyst to be added as necessary during the above melt-kneading, a usual radical polymerization catalyst can be used, such as benzoyl peroxide, lauroyl peroxide,
Ditert-butyl peroxide, acetyl peroxide, tert-butyl peroxybenzoic acid, dicumyl peroxide, peroxybenzoic acid, peroxyacetic acid, tert-butyl peroxypivalate, 2,5-dimethyl-2,5-
Peroxides such as ditertiary-butylperoxyhexine and diazo compounds such as azobisisobutyronitrile are preferred. The amount of the catalyst added is approximately 0.01 to 3 parts by weight per 100 parts by weight of the styrenic block copolymer. Furthermore, a phenolic antioxidant can be added during the graft reaction, but it is preferable not to add it if a radical polymerization catalyst is not added. The content of the unsaturated carboxylic acid or its anhydride, or the epoxy group-containing monomer in the modified styrenic block copolymer is preferably within the range of 0.01 to 10% by weight. Specifically, in the case of modification with maleic anhydride, the content of maleic anhydride is 0.2 to 5% by weight, more preferably 0.5 to 5% by weight.
3% by weight, and when glycidyl methacrylate is used, its content is 0.2 to 5% by weight, more preferably 0.2 to 3% by weight. If the amount of modification by maleic anhydride and himic anhydride is less than the above lower limit, there will be no sufficient effect on improving the compatibility between polyethylene and polyester, and if it exceeds the upper limit, mechanical strength will decrease. (a) polyester as described above;
The blending ratio of (b) polyethylene, (c) epoxy group-containing ethylene copolymer, and (d) modified styrene block copolymer is (a) + (b) + (c
) (a) polyester is 50 to 95 weight %, preferably 60 to 90 weight %, (b) polyethylene is 1 to 49 weight %, preferably 10 to 40 weight %, (c) 1 to 30% by weight of epoxy group-containing ethylene copolymer, preferably 1 to 30% by weight
It is 10% by weight. (a) 50% by weight polyester
If it is less than 95% by weight, the properties of the polyester will be impaired, while if it exceeds 95% by weight, the effect of the addition of polyethylene will not be sufficiently exhibited. In addition, (b) if polyethylene is less than 1% by weight, the effect of weight reduction etc. due to its addition cannot be sufficiently obtained,
On the other hand, if it exceeds 49% by weight, the amount of polyester will be too small, resulting in a decrease in mechanical strength. Furthermore, (c) if the epoxy group-containing ethylene copolymer is less than 1% by weight, the effect of improving the compatibility between polyester and polyethylene by its addition is insufficient, while if it exceeds 30% by weight, the mechanical strength and moldability Processability decreases. Furthermore, the amount of the modified styrenic block copolymer (d) added is 1 to 15 parts by weight per 100 parts by weight of the total of (a) + (b) + (c). If the content of the modified styrenic block copolymer is less than 1 part by weight, the effect of improving moldability and elongation properties due to its addition will not be sufficient, and if it exceeds 15 parts by weight, heat resistance and rigidity will decrease. . The content of the modified styrenic block copolymer is preferably 2 to 10 parts by weight. The thermoplastic resin composition of the present invention has the above composition, but for the purpose of strengthening and modifying it, other fillers, reinforcing materials, heat stabilizers, light stabilizers, flame retardants, plasticizers, Antistatic agents, foaming agents, nucleating agents, etc. can be added. [0056] The thermoplastic resin composition of the present invention as described above is prepared by mixing the above-mentioned components at 220 to 300°C using a kneading machine such as a single screw extruder, twin screw extruder, Banbury mixer, kneading roll, or Brabender. Preferably 230 to 280
It can be obtained by heating and kneading in a molten state at °C. Note that the melt-kneading can be performed for each component all at once or divided into two or more steps. [Function] The thermoplastic resin composition of the present invention contains an epoxy group-containing ethylene copolymer and a modified styrene block copolymer as a compatibilizer for polyester and polyethylene. Polyester and polyethylene are well compatible with each other, and it has excellent mechanical strength such as impact resistance and elongation properties, moldability, etc., and is lightweight. The reason why such an effect is obtained is not necessarily clear, but polyester, which has excellent mechanical strength, insulation properties, and impact resistance, and polyethylene, which has excellent moldability, chemical resistance, and water resistance, are combined with epoxy group-containing polyester. By making it compatible with an ethylene copolymer and adding a specific amount of a modified styrene block copolymer, it is possible to further improve the compatibility of the two and improve elongation properties and formability. This is thought to be due to the EXAMPLES The present invention will be explained in more detail with the following specific examples. In addition, in each Example and Comparative Example, the following materials and additives were used. [1] Polyester polybutylene terephthalate PBT: [TRB J manufactured by Teijin Ltd., intrinsic viscosity [η]
0.87] [2] Polyethylene/high density polyethylene HDPE: [Melt index (MI, 190 °C,
2.16 kg load) 0.2 g/10 min, density (A
STM D1505) 0.935g/cm 3 ]・Linear low density polyethylene LLDPE: [Melt index (MI, 190 ℃
, 2.16kg load) 4.0g/10 min, density (AS
TM D1505) 0.934 g/cm3]・Low density polyethylene LDPE: [Melt index (MI, 190 ℃,
2.16 kg load) 2.4 g/10 min, density (A
STM D1505) 0.923 g/cm3] [3
] Epoxy group-containing ethylene copolymer/ethylene-glycidyl methacrylate random copolymer EGMA: [Bonto First E manufactured by Sumitomo Chemical Co., Ltd.] [4] Modified styrene block copolymer CMSEBS
-1: [Epoxy-modified styrene-hydrogenated butadiene-styrene block copolymer, manufactured by Asahi Kasei Corporation: Tuftec Z513] CMSEBS-2: [Carboxylic acid-modified styrene-hydrogenated butadiene-styrene block copolymer, Asahi Kasei Corporation Co., Ltd.: Tuftec M1943] CMSEPS-1: [Carboxylic acid-modified styrene-hydrogenated isoprene-styrene block copolymer, Kuraray Co., Ltd.: Septon KL03M2] Examples 1 to 5, Comparative Example 1 Polyester (PBT) and polyethylene (HPP,
LDPE or LLDPE), an epoxy group-containing ethylene copolymer (EGMA), and a modified styrenic block copolymer (CMSEBS-1, CMSEBS-2 or C
MSEPS-1) in the proportions shown in Table 1 using a Henschel mixer, and then
250°C using a 5mmφ, L/D=28 twin screw extruder
, and kneaded at 200 rpm to obtain a thermoplastic resin composition. Melt flow rate of the thermoplastic resin composition thus obtained (250°C, 2.16kg
load), tensile yield strength, tensile elongation at break, flexural modulus,
Izod impact strength, heat distortion temperature, and specific gravity were measured. The results are shown in Table 2. [0062] No.
1 Table Composition Weight part Example 1 Example 2 Example 3 Example 4 PBT 80
80 80
80 HDPE 14
11-
- LLDPE -
-14
-LDPE-
- - 14
EGMA 4
4 4 4
CMSEBS-1 2
5 2
2 0063
1 Table (continued) Composition Weight part Example 5 Example 6
Comparative example 1 Comparative example 2 PBT
80 80 80
80 HDPE 14
14 16
10 EGMA 4
4 4
10 CMSEBS-2 2
− −
- CMSEPS-1
- 2 -
-0064
2 Surface properties Example 1 Example 2 Example 3 Example 4
MFR

(g/1
0 minutes) (1) 7.4
11 9.3 9.1
tensile yield strength


(kg/cm2) (2) 440
440 440
420 Tensile elongation at break


(%) (3)
200 280 160
200 Flexural modulus

(kg/cm2) (4)
19000 18000 1
9000 18000
Izod impact strength

(kg ・cm/cm) (5
) 40 56
22 43
heat distortion temperature

(℃) (
6) 115 113
110 105
specific gravity


(g/cm3) (7) 1.22
1.22 1.21
1.21 0065
2 Table (continued)
Example 5 Example 6
Comparative example 1 Comparative example 2 MFR


(g/10 min) (1) 7.6
6.8 2.1
0.9 Tensile yield strength

(kg/cm2
) (2) 430 43
0 410 420
Tensile elongation at break

(%) (3)
160 150
30 100 Flexural modulus

(kg/cm2) (4) 190
00 20000 19000
16000 Izod impact strength

(kg・cm
/cm) (5) 24 2
8 8 12
heat distortion temperature

(℃) (6)
116 120
120 117 specific gravity

(g/cm3) (7)
1.22 1.22 1.22
1.22 (1) MFR: 250 according to ASTM D1238
Measured at ℃ and 2.16 kg load. (2) Tensile yield strength: Measured according to ASTM D638. (3) Tensile elongation at break: Measured according to ASTM D638. (4) Flexural modulus: Measured according to ASTM D790. (5) Izod impact strength: Measured at 23°C with a notch according to ASTM D256. (6) Heat distortion temperature: 4 according to ASTM D648.
Measured at 6kg/cm2. (7) Specific gravity: Measured according to ASTM D792. As is clear from Table 2, Examples 1 to 6
The thermoplastic resin composition has good tensile yield strength, tensile elongation at break, flexural modulus, Izod impact strength, and heat distortion temperature, and is particularly good in comparative examples that do not contain modified styrenic block copolymers. Compared with the thermoplastic resin compositions of Comparative Example 1 and Comparative Example 2, the tensile elongation at break, fluidity, and impact resistance were good. Effects of the Invention As detailed above, the thermoplastic resin composition of the present invention contains an epoxy group-containing ethylene copolymer and a modified styrene block copolymer as a compatibilizer for polyester and polyethylene. Since it contains a combination of
Polyester and polyethylene are well compatible, and it has excellent mechanical strength such as impact resistance and elongation characteristics, moldability, etc., and is lightweight. The thermoplastic resin composition of the present invention is suitable as various engineering plastics, particularly as a resin composition for automobile interior and exterior parts, home appliance parts, industrial material parts, packaging materials, and the like.

Claims (5)

[Claims] Claim 1: (a) 50-95% by weight of polyester; (b) 1-49% by weight of polyethylene; (c)
(d) 1 to 15 parts by weight of the modified styrenic block copolymer based on 1 to 30 parts by weight of the epoxy group-containing ethylene copolymer and 100 parts by weight of the above (a) + (b) + (c). A thermoplastic resin composition comprising: 2. The thermoplastic resin composition according to claim 1, wherein the styrenic block copolymer is a hydrogenated styrene-isoprene-styrene block copolymer or a hydrogenated styrene-butadiene-styrene block copolymer. A thermoplastic resin composition characterized in that it is selected from. 3. The thermoplastic resin composition according to claim 1 or 2, wherein the modified styrenic block copolymer (d) is a modified product with an epoxy group-containing monomer. thing. 4. The thermoplastic resin composition according to claim 1, wherein the modified styrenic block copolymer (d) is a modified product with an unsaturated carboxylic acid or an anhydride thereof. Characteristic thermoplastic resin composition. 5. The thermoplastic resin composition according to claim 1, wherein the polyester (a) is polybutylene terephthalate or polyethylene terephthalate.