JPH06145478A - Thermoplastic resin composition - Google Patents

Abstract

PURPOSE:To provide the subject composition containing a specified ratio of a polyester, a rubber modified with a glycidyl compound and polypropylene containing a polypropylene modified with a specified modified acrylamide, excellent in low-temperature impact strength and stiffness and useful for an automobile component, an appliance part, etc. CONSTITUTION:The objective thermoplastic resin composition improved in low-temperature impact strength and excellent in stiffness is obtained by blending (A) a polyester (e.g. polyethylene terephthalate), (B) rubber modified with a glycidyl compound (e.g. glycidyl acrylate) and (C) polypropylene containing >=2wt.% polypropylene modified with a glycidyl group-containing acrylamide- based compound represented by the formula [R is H or a 1 to 6C alkyl; Ar is a 6 to 20C aromatic hydrocarbon having one or more glycidyloxy groups; (n) is an integer of 1 to 4] in a ratio of the components (A), (B) and (C) satisfying (A)/[(B)+(C)]: 98/2 to 30/70 and (B)/(C)= 5/95 to 95/5 on weight base.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermoplastic resin composition comprising polyester, modified rubber and modified polypropylene. More specifically, heat composed of polyester, epoxy-modified rubber and unsaturated glycidyl compound-modified polypropylene, which can be suitably used for automobile interior / exterior parts, household electric appliances, industrial parts such as belts, sports equipment, furniture, etc. It relates to a plastic resin composition.

[0002]

2. Description of the Related Art Polyesters such as polyethylene terephthalate and polybutylene terephthalate are excellent in heat resistance and mechanical strength and are widely used as engineering plastics. However, since polyester has a high specific gravity, it is not possible to reduce the weight of the product, and it is inferior in impact resistance (low temperature impact strength) and tensile properties.

In order to reduce the weight of polyester products, it is conceivable to add a polyolefin having a low specific gravity, but even if the polyolefin is simply blended, the impact strength cannot be improved because the compatibility with the polyester is poor. Therefore, various compositions have been proposed in which polyolefin or olefin elastomer is modified and blended with polyester (Japanese Patent Publication No. 58-47419 and Japanese Patent Laid-Open No. 60-219254).
No. 1-193351, JP-A 1-236266, etc.) and improvement of physical properties such as impact resistance are insufficient.

On the other hand, it has been attempted to blend a rubber component in order to improve the impact resistance of polyester (Japanese Patent Laid-Open No. 55-139448, Japanese Patent Publication No. 58-47419, etc.), but a rubber component was blended. However, even if the impact strength is improved, the original rigidity (mechanical strength) of polyester is sacrificed.

Therefore, the object of the present invention is to solve the problem that the rigidity is lowered when the rubber component is blended with polyester to improve the low temperature impact strength, and the polyester based on the excellent low temperature impact strength and the rigidity is used. To provide a thermoplastic composition.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that low temperature impact strength and rigidity are improved by blending polyester modified rubber with a glycidyl compound and polypropylene modified with a specific unsaturated glycidyl compound. The present invention has been accomplished by finding that a composition having satisfactory properties on both sides can be obtained.

That is, the present invention comprises (a) a polyester and (b) a rubber modified with a glycidyl compound,
(C) The following general formula

[Chemical 2] [In the formula, R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms having at least one glycidyloxy group, and n
Represents an integer of 1 to 4. ] Polypropylene containing 2% by weight or more of polypropylene modified with a compound represented by the formula (a), (b) and (c) is contained in a weight ratio of (a) / {(b) + (C)} = 98/2
˜30 / 70 and (b) / (c) = 5 / 95˜95
The thermoplastic resin composition is characterized by being / 5.

Hereinafter, the thermoplastic resin composition of the present invention will be described in detail. The polyester of the raw material component (a) of the thermoplastic resin composition of the present invention is generally a thermoplastic resin obtained by polycondensation of a saturated dicarboxylic acid and a saturated dihydric alcohol, and examples thereof include polyethylene terephthalate, polypropylene terephthalate and polytetramethylene. Examples thereof include terephthalate (polybutylene terephthalate), polyhexamethylene terephthalate, polycyclohexane-1,4-dimethylol terephthalate, and polyneopentyl terephthalate. Of these, polyethylene terephthalate and polybutylene terephthalate are preferred. The above polyester has an intrinsic viscosity [η] (dl / g) of 0.30 to 1.8 determined from a solution viscosity measured at 25 ° C. in an o-chlorophenol solvent and a terminal carboxyl group concentration of 10 to 200 meq / kg. Those are preferable.

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 meq / kg. The terephthalic acid component in polyethylene terephthalate may be substituted with an alkyl group, a halogen group or the like, and the glycol component may be ethylene glycol up to about 50% by weight of another glycol such as 1,4-butylene. It may contain glycol, propylene glycol, hexamethylene glycol or the like.

In the case of polybutylene terephthalate, it is preferable that the intrinsic viscosity [η] is 0.30 to 1.8 and the terminal carboxyl group concentration is 10 to 200 meq / kg. Also in this case, the terephthalic acid component may be substituted with an alkyl group, a halogen group or the like, and the glycol component may be 1,
In addition to 4-butylene glycol, other glycols such as ethylene glycol, propylene glycol and hexamethylene glycol may be contained up to about 50% by weight.

The base rubber used as the raw material for the (b) unsaturated glycidyl compound-modified rubber of the thermoplastic resin composition of the present invention exhibits rubber elasticity at room temperature, and has ethylene-α-olefin rubber (olefin elastomer) and styrene rubber. It is rubber.

Here, the olefin rubber is a copolymer of ethylene and one or more α-olefins other than ethylene such as propylene, 1-butene, 1-hexene and 4-methyl-pentene. Means rubber. The polymer rubber of ethylene and one or more kinds of α-olefins other than ethylene is typically ethylene-
Examples thereof include propylene copolymer rubber (EPR), ethylene-butene copolymer rubber (EBR), ethylene-propylene-diene copolymer rubber (EPDM) and the like. As the diene in the ethylene-propylene-diene copolymer rubber (EPDM), a non-conjugated diene such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene or a conjugated diene such as butadiene or isoprene is used. be able to.

The content of ethylene in the olefin elastomer is 5 to 95% by weight, preferably 10 to 90.
% By weight. When the ethylene content is less than 5% by weight or exceeds 95% by weight, it becomes difficult to exhibit properties as an elastomer. The crystallinity of such an olefin elastomer is usually 40% by weight or less.

The ethylene-propylene copolymer rubber (EPR) used in the present invention has a content of repeating units derived from ethylene of 50 to 80 mol% and a content of repeating units derived from propylene of 20 to 20 mol%. It is preferably 50% by weight. A more preferable range is 30 to 40 mol% of ethylene-based repeating units and 30 to 40 mol% of propylene-based repeating units. Also, EPR
The melt flow rate (MFR, 230 ° C., 2.16 kg load) is preferably 0.01 to 50 g / 10 minutes, more preferably 0.5 to 30 g / 10 minutes.

The ethylene-butene copolymer rubber (EBR) used in the present invention has a content of repeating units derived from ethylene of 50 to 90 mol% and a content of repeating units derived from butene of 10 to 10. It is preferably 50% by weight. A more preferable range is 60 to 80 mol% of ethylene-based repeating units and 20 to 40 mol% of butene-based repeating units. In addition, the EFR MFR (2
The load (30 ° C., 2.16 kg load) is preferably within the range of 0.01 to 50 g / 10 minutes, more preferably 0.5 to 30 g / 10 minutes.

The ethylene used in the present invention
The propylene-diene copolymer rubber (EPDM) has a repeating unit content of 40 to 70 derived from ethylene.
It is preferable that the content of the repeating unit derived from propylene is 30 to 60% by weight, and the content of the repeating unit derived from a diene is 1 to 10% by mole. A more preferable range is 50-60 mol% of ethylene-based repeating units and 40-60% of propylene-based repeating units.
50 mol% and 3 to 6 mol% of diene-based repeating units. Furthermore, MDM of EPDM (230 ℃, 2.16
(kg load) is preferably in the range of 0.01 to 50 g / 10 minutes, more preferably 0.1 to 30 g / 10 minutes.

The ethylene-propylene copolymer rubber (EPR), ethylene-butene copolymer rubber (EBR) and ethylene-propylene-diene copolymer rubber (EPDM) used in the present invention are basically the above-mentioned ones. It is composed of repeating units, but may be, for example, 4-methyl-pentene-1 within a range that does not impair the properties of these copolymers.
Other repeating units, such as repeating units derived from other α-olefins such as, may be included up to a proportion of 10 mol% or less.

The styrene-based rubber is a styrene-based block copolymer exhibiting rubber elasticity, for example, styrene-butadiene-styrene block copolymer (SBS).
And its hydride (SEBS), styrene-isoprene-styrene copolymer (SIS) and its hydride (SEPS), styrene-butadiene copolymer (SB)
And its hydride (SEB), styrene-isoprene copolymer and its hydride (SEP), and the like.

The SEBS is represented by the following general formula.

Embedded image _{(S-EB) p -S q} ( wherein, S is expressed styrenic moiety, EB is hydrogenated butadiene moiety (ethylene-butylene moiety) respectively, p is 1
Is an integer of 20 and q represents 0 or 1. )

As the above SEBS, two-block type (SEB when p = 1 and q = 0), three-block type (when p = 1 and q = 1), and multi-block type ( (when p = 2 to 20), any of them can be used in the present invention. SEBS is hydrogenated at a temperature of 25 to 175 ° C. in the presence of a catalyst obtained by reducing SBS to an alkoxide of cobalt or nickel with an alkylaluminum compound to selectively hydrogenate only a butadiene portion,
It has a structure corresponding to an ethylene / butylene copolymer.

In the above SEBS, it is not necessary that all of the butadiene portion be hydrogenated, and 5% or more may be hydrogenated. 50% preferred hydrogenation rate
Or more, more preferably 80% or more.

In the present invention, the content of the polystyrene moiety in such a polystyrene block copolymer is
It is about 10 to 80% by weight, preferably 20 to 70% by weight. If the polystyrene portion is less than 10% by weight, (a)
The effect of improving the compatibility between the polypropylene resin and the polystyrene resin (b) is not sufficient, and when it exceeds 80% by weight, embrittlement occurs. The content of the polystyrene portion in the polystyrene block copolymer is usually about 15 to 35% by weight, but in the present invention, the styrene content is 10 to 35% by weight.
If it is up to 80% by weight, it can be used. The polystyrene portion in the polystyrene block copolymer is not limited to styrene alone, and may be substituted styrene such as methyl styrene.

The weight average molecular weight of such a polystyrene block copolymer is preferably 3 × 10 ⁴ to 50 × 10 ⁴ , and particularly preferably 5 × 10 ^{4 to} 35 × 10 ⁴ . If the weight average molecular weight is less than 3 × 10 ⁴ , the melt viscosity is too low, while if it exceeds 50 × 10 ⁴ , the melt viscosity becomes too high and the moldability deteriorates, which is not preferable. Among the above rubbers, preferred rubbers are SEBS, SEPS, SE
Among B, SEP, SEPS and SEBS are preferable. In the present invention, the above rubber components are usually used alone, but two or more kinds may be used in combination.

The component (b) of the resin composition of the present invention is the above rubber modified with a glycidyl compound. Here, a saturated or unsaturated glycidyl compound having at least one epoxy group is used as the modifier glycidyl compound. Examples of the saturated glycidyl compound include compounds having two epoxy groups such as terephthalic acid diglycidyl ester and bisphenol A glycidyl ether. The unsaturated glycidyl compound has the general formula
(I)

[0025]

[Chemical 4]

[Wherein R represents a hydrogen atom or a carbon number of 1 to 6]
Of Ar, Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms and having at least one glycidyloxy group, and p represents an integer of 1 to 4. ], General formula (II)

[0027]

[Chemical 5]

[In the formula, R represents the same meaning as described above. ]
Or general formula (III)

[0029]

[Chemical 6]

[In the formula, X represents a methylene group or a phenylene group, and R represents the same meaning as described above. ] The polymerizable compound which has an unsaturated group and glycidyloxy group which can be copolymerized with olefin shown by these is mentioned. Among these modifiers, unsaturated glycidyl compounds are preferred,
The compounds represented by the general formula (I) and the general formula (II) are more preferable. Among the unsaturated glycidyl compounds represented by the general formula (I), the compound represented by the following general formula (IV) is particularly preferable.

[0031]

[Chemical 7]

[In the formula, R represents the same meaning as described above. ]
Such a glycidyl compound is disclosed, for example, in JP-A-60-13058.
It can be produced by the method shown in No. 0.

As the unsaturated glycidyl ester represented by the general formula (II) and the unsaturated glycidyl ether represented by the general formula (III), glycidyl acrylate (G
A), glycidyl methacrylate (GMA), allyl glycidyl ether, 2-methylallyl glycidyl ether, styrene-p-glycidyl ether and the like,
Of these, glycidyl methacrylate (GMA) is preferable. These polymerizable compounds are usually used alone,
It is also possible to use two or more types in combination.

The preferred glycidyl compound-modified rubber in the present invention is the above-mentioned raw material rubber, especially EPR, EBR,
EPDM, SEPS, and SEBS are modified with an unsaturated glycidyl compound represented by the above general formula (I), particularly a glycidyl compound represented by the general formula (IV). The content of the modifier (glycidyl compound) in the modified rubber varies depending on the type of raw rubber and cannot be generally stated, but it is generally about 0.01 to 30% by weight, preferably 0.01 to 10% by weight. When the content of the glycidyl compound is less than 0.01% by weight, the modification of the olefinic elastomer is insufficient, and when the content exceeds 30% by weight, it is not economical and gelation occurs when blending with the polyester.

Such modified rubber can be obtained by utilizing a known modification method such as a solution method or a melt-kneading method. In addition, a desired product may be appropriately selected and used from commercially available products.

As a specific example of the modification method, a method by graft polymerization will be described below. That is, in the melt-kneading method, rubber, the above-mentioned glycidyl compound, and, if necessary, a catalyst are used, and these components are put into an extruder, a twin-screw kneader, or the like and heated to a temperature of about 180 to 300 ° C. While being melted, the mixture is kneaded for 0.1 to 20 minutes to obtain a modified olefin elastomer. In the case of the solution method, the above-mentioned starting materials are dissolved in an organic solvent such as xylene and the temperature is 90 to 200 ° C.
Denaturation is carried out at a temperature of about 0.1 to 100 hours with stirring.

In any of the modification methods, a conventional catalyst for radical polymerization such as benzoyl peroxide, lauroyl peroxide, ditertiary butyl peroxide, acetyl peroxide, tert-butyl peroxybenzoic acid, dicumyl peroxide is used as a catalyst. , Peroxybenzoic acid, peroxyacetic acid,
Use of peroxides such as tertiary butyl peroxypivalate and 2,5-dimethyl-2,5-ditertiary butyl peroxyhexyne, and azo compounds such as α, α-azobisisobutyronitrile You can The amount of the catalyst added is about 0.1 to 10 parts by weight with respect to 100 parts by weight of the modifying glycidyl compound. It is also possible to add a phenolic antioxidant during the above graft reaction.

The component (c) of the resin composition of the present invention is an unsaturated glycidyl compound represented by the above general formula (I) having an acrylamide group and an epoxy group described in the rubber modifier of the component (b), In particular, it is a polypropylene containing 2% by weight or more of polypropylene modified with the compound represented by the general formula (IV). Here, the polypropylene used as the modified raw material and the unmodified polypropylene is not limited to a homopolymer, but is a random or block copolymer with another α-olefin containing a propylene component in an amount of 50 mol% or more, preferably 80 mol% or more. Can be used. The following general formula

[0039]

[Chemical 8]

(Wherein R ^{1 to} R ⁴ represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, m represents an integer of 1 to 20) and a propylene random group containing a non-conjugated diene comonomer is represented. You may use a copolymer (PPDM) etc.

As the non-conjugated diene used for PPDM, for example, 2-methyl-1,4-pentadiene,
1,4-hexadiene, 4-methylidene-1-hexene, 4-methyl-1,4-hexadiene, 5-methyl-
1,4-hexadiene, 1,4-heptadiene, 4-ethyl-1,4-hexadiene, 4,5-dimethyl-1,
4-hexadiene, 4-methyl-1,4-heptadiene, 4-ethyl-1,4-heptadiene, 5-methyl-
1,4-heptadiene, 5-methyl-1,4-octadiene, 1,5-heptadiene, 1,5-octadiene,
5-methyl-1,5-heptadiene, 6-methyl-1,
5-heptadiene, 2-methyl-1,5-hexadiene, 1,6-octadiene, 6-methyl-1,6-octadiene, 7-methyl-1,6-octadiene, 2-methyl-1,6-heptadiene, 1,9-decadiene,
1,13-tetradecadiene and the like can be mentioned. Among these, especially 1,4-hexadiene and 2-methyl-
1,4-pentadiene, 1,9-decadiene and the like are preferable. These non-conjugated diene comonomers are usually used alone, but two or more kinds can be used in combination.

In order to randomly copolymerize propylene and a non-conjugated diene comonomer, an ordinary copolymerization method using a Ziegler-Natta catalyst may be applied. In this case, it is preferable that the proportion of the non-conjugated diene is 0.05 to 10 mol%. Non-conjugated diene content is 0.05 mol%
When it is less than 10% by weight, a high graft ratio cannot be obtained in the subsequent grafting reaction, and when it exceeds 10 mol%, the crystallinity of the copolymer is significantly lowered. The more preferable content of the non-conjugated diene is 0.1 to 3 mol%.

Other unsaturated monomers such as ethylene and butene-1 may be copolymerized with the random copolymer in an amount of 5 mol% or less. The molecular weight of this copolymer is usually 1
It is in the range of 0,000 to 1,000,000.

The content of the unsaturated glycidyl compound represented by the general formula (I) as a modifier of the polypropylene varies depending on the kind of the raw material polypropylene and cannot be generally stated, but is generally about 0.01 to 30% by weight, preferably is 0.
It is from 01 to 10% by weight. The content of glycidyl compound is 0.
If it is less than 01% by weight, modification of polypropylene is insufficient, and if it exceeds 30% by weight, it is not economical, and gelation occurs when blending with polyester.

Preparation of such modified polypropylene is
Similar to the case of modifying the rubber with the glycidyl compound, the above-mentioned component (b) can be carried out by a solution method or a melt-kneading method using an ordinary radical polymerization catalyst.

Component (a) in the resin composition of the present invention,
The mixing ratios of the components (b) and (c) are as follows:
The weight ratio of the components (b) and (c) is (a) /
{(B) + (c)} = 98/2 to 30/70, preferably 90/10 to 50/50. Weight ratio 30/70
If it is less than 100%, the rigidity is lowered, and if it exceeds 98/2, the impact strength is not improved.

The weight ratio of (b) to (c) is (b) / (c) = 5/95 to 95/5, preferably 1.
It is 0/90 to 90/10. If the weight ratio is less than 5/95, the low temperature impact strength is not improved, and if it exceeds 95/5, the rigidity is lowered. Further, by blending the unmodified polypropylene in the component (c), the production cost can be reduced and the moldability can be improved.
When the content is more than wt%, the compatibility is lowered and the molded product is exfoliated on the surface.

Further, in the present invention, other substances, for example, for the purpose of strengthening or modifying the thermoplastic resin composition, for example,
Fillers and reinforcements such as glass fiber, heat stabilizers, light stabilizers,
A flame retardant, a plasticizer, an antistatic agent, a foaming agent, a nucleating agent, etc. can be added and blended.

As the melt-kneading method, various conventionally known methods can be adopted. That is, a batch kneading method using a batch type kneading machine, a kneading method using a kneading machine such as a Banbury mixer, a Brabender, a kneading roll, a single-screw extruder, or a twin-screw extruder can be exemplified. The kneading temperature is 230 to 300 ° C., preferably 240
Is in the range of 280 ° C. If the kneading temperature is lower than 230 ° C, the polyester and the polyolefin-based elastomer may not be sufficiently compatibilized, and if the kneading temperature exceeds 300 ° C, the original properties of the resin may be impaired.

In the present invention, the kneading order of the respective components is not particularly limited, and the three components of the component (a) polyester, the component (b) glycidyl compound-modified rubber and the component (c) unsaturated glycidyl compound-modified polypropylene are used. They may be kneaded all at once or may be kneaded in any order. That is, (i) the components (a), (b), and (c) are simultaneously charged into a batch-type kneader, a Brabender, or a kneader such as a single-screw or twin-screw extruder to knead at once. , (Ii) the component (a) and the component (b) are simultaneously charged into the extruder, and then the component (c) is charged from the middle of the barrel and kneaded, (iii) the component (b) and the component (C) is charged into the extruder at the same time, then component (a) is charged in the middle, and (iv) component (a) and component (b) are charged into the extruder at the same time, and then component (c) is added. For example, the method of charging in the middle.

[0051]

The reason why the thermoplastic resin composition of the present invention obtained by blending a polyester modified with a glycidyl compound-modified rubber and a polypropylene modified with a specific unsaturated glycidyl compound is excellent in rigidity and impact resistance is Although not necessarily clear, the polypropylene and the polyester modified with an unsaturated glycidyl compound, and the glycidyl compound-modified rubber and the unsaturated glycidyl compound-modified polypropylene have an affinity, as a result, with the polyester through the modified polypropylene. It is considered that this is due to good compatibility with the glycidyl compound-modified rubber.

[0052]

The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples. In the examples and comparative examples, the following raw material components and additives were used.

Polyester (1) Polybutylene terephthalate (PBT): C 7000N manufactured by Teijin Ltd., intrinsic viscosity [η] 1.05 (in o-chlorophenol). (2) Polyethylene terephthalate (PET): TR 4550BH manufactured by Teijin Ltd., intrinsic viscosity [η] 0.70 (in o-chlorophenol).

Modified rubber GMA Modified SEBS (modified SEBS): Asahi Kasei Corp.
Z 513, styrene content 30% by weight, MFR (230
℃, 2.16kg load) 3.5 g / 10 minutes, GMA content 1% by weight.

Rubber SEBS: Asahi Kasei Corporation H 1041, styrene content 3
0% by weight, MFR (230 ° C, 2.16 kg load) 5.0 g / 10 minutes

Polyolefin (1) Homopolypropylene (Homo PP): Tonen Chemical Co., Ltd.
Made: J209, MFR (230 ℃, 2.16kg load) 8.5 g / 10
Minutes. (2) Block polypropylene (Block PP): Tonen Chemical Co., Ltd .: BJ510, MFR (230 ° C, 2.16kg load)
10g / 10 minutes.

Organic peroxide POX: Perhexin 25B (manufactured by NOF CORPORATION).

Modified polypropylene AXE modified polypropylene (modified PP): homopolypropylene (MFR (230 ° C., 2.16 kg load) 1.0 g / 10 minutes)
100 parts by weight of organic peroxide (POX) 0.03 parts by weight and unsaturated glycidyl compound (AXE) represented by the following chemical formula [Kanefuchi Chemical Industry Co., Ltd.]

[Chemical 9] After dry blending 3 parts by weight of
0mmφ, L / D ratio 30), screw rotation speed 6
Melted and kneaded at 0 rpm and a temperature of 200 ° C and pelletized. AX graft ratio: 2.4% by weight, MFR (230
℃, 2.16kg load) 9.5 g / 10 minutes.

Here, the graft ratio of AXE was calculated as follows. The modified polypropylene was dissolved in boiling xylene, reprecipitated in methanol, the precipitated polymer was vacuum dried, and this was hot pressed into a film having a thickness of about 50 μm. The IR of the obtained film is measured,
Calculate the ratio of absorbance between the peak (1648 cm ^-1 ) associated with the expansion and contraction of the carbonyl (C = O) bond of the denaturant and the peak (840 cm ^-1 ) peculiar to isotactic polypropylene, and prepare the calibration value prepared in advance. Calculated using the line.

Examples 1 to 11 and Comparative Examples 1 to 16 Polyesters (PBT, PET) in proportions shown in Table 1.
And rubber (SEBS, modified SEBS) and polypropylene (modified PP, homo PP, block PP) were mixed by a Henschel mixer, and this was mixed with a diameter of 45 mm and L / D.
Using a twin-screw extruder with a ratio of 30 and a screw rotation speed of 20
0 rpm, temperature 250 ℃ (when using PBT) and temperature 28
The mixture was melt-kneaded at 0 ° C. (when using PET), pelletized, and injection-molded. The flexural modulus of the thermoplastic resin composition thus obtained, Izod impact strength (23 ° C.,
-30 ° C), Rockwell hardness, and surface peeling property were measured. The results are also shown in Table 1.

[0061]

[Table 1]

[0062]

[Table 2]

[0063]

[Table 3]

[0064]

[Table 4]

The methods for measuring the physical properties shown in Table 1 above are as follows. (1) Flexural modulus (23 ° C.): measured by ASTM D790. (2) Izod impact strength (23 ℃, -30 ℃): ASTM D
Measured by 256. (3) Rockwell hardness (23 ° C): measured by ASTM D785. (4) Surface releasability: 100 squares of 1 mm x 1 mm were attached to the surface of the test piece using a razor, cellophane tape (manufactured by Nichiban Co., Ltd.) was attached to the squares, and then peeled off.
Among 100 squares, the number of squares left on the surface of the test piece without adhering to the cellophane tape was counted.

As is clear from Table 1, even if the polyester was simply blended with unmodified polypropylene (Comparative Example 3).
~ 5, 12), as shown by the data of the surface peeling test, improvement in mechanical properties cannot be expected. In the case where only AXE-modified polypropylene is blended with polyester (Comparative Examples 6 to 8,
13) Surface peeling is suppressed, but low temperature impact strength is not improved. On the other hand, polyester has rubber (SEBS, modified S
In the case of blending only EBS (Comparative Examples 9 to 11, 1
4-16) The impact strength is improved, but the flexural modulus is significantly reduced.

On the other hand, the polyester of the present invention (PB
T) The composition of Example 1 consisting of 90 parts by weight and modified SEBS and modified PP of 10 parts by weight has improved impact strength as compared to the composition of Comparative Example 6 consisting of a considerable amount of polyester and modified PP, The flexural modulus was improved as compared to the composition of Comparative Example 9 consisting of polyester and modified SEBS. Further, 80 parts by weight of the polyester (PBT) of the present invention, modified SEBS and modified PP (and unmodified PP)
The modified compositions of Examples 2 to 4 containing 20 parts by weight of modified PP containing 20% by weight of the modified PP have improved low-temperature impact strength, in particular, as compared with the composition of Comparative Example 7 composed of a considerable amount of polyester and modified PP. The flexural modulus is improved as compared to the composition of Comparative Example 10 consisting of polyester and modified SEBS.

Further, the polyester (PBT) of the present invention
Example 5 consisting of 70 parts by weight and 30 parts by weight of modified SEBS and modified PP (and modified PP including unmodified PP)
The compositions Nos. 9 to 9 have particularly improved low temperature impact strength, no surface peeling, and polyester and modified SEB as compared to the composition of Comparative Example 8 comprising a considerable amount of polyester and modified PP.
The flexural modulus was improved compared to the composition of Comparative Example 11 containing S. Also in the composition of Example 10 using PET as polyester, the low temperature impact strength was improved as compared with Comparative Examples 13 and 14.

[0069]

As described in detail above, the thermoplastic resin composition of the present invention comprises polyester, an epoxy modified rubber and an unsaturated glycidyl compound modified polypropylene. The rubber component is blended with the polyester to improve the low temperature impact strength. It is a composition that secures the inherent rigidity of polyester while aiming. Such a thermoplastic resin composition of the present invention is used as various engineering plastics, particularly for automobile interior / exterior parts, home electric appliances parts, industrial parts such as belts, sports equipment, furniture, etc., and further has low temperature characteristics. It is suitable as a resin composition such as a ski boot material.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI technical display location // C08G 59/34 NHU 8416-4J (72) Inventor Shintaro Kikuchi Nishitsuruga, Oimachi, Iruma-gun, Saitama Prefecture Oka 1-3-1 Tonen Co., Ltd. Research Institute (72) Inventor Yuji Fujita Nishitsurugaoka 1-3-3-1, Otsui, Iruma-gun, Saitama Tonen Co. Research Institute

Claims (1)

[Claims] 1. A polyester (a), a rubber modified with a glycidyl compound (b), and (c) the following general formula: [In the formula, R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, Ar is an aromatic hydrocarbon group having 6 to 20 carbon atoms having at least one glycidyloxy group, and n
Represents an integer of 1 to 4. ] Polypropylene containing 2% by weight or more of polypropylene modified with a compound represented by the formula (a), (b) and (c) is contained in a weight ratio of (a) / {(b) + (C)} = 98/2
˜30 / 70 and (b) / (c) = 5 / 95˜95
/ 5, the thermoplastic resin composition.