JPH05287164A - Thermoplastic elastomer composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition having excellent heatresistance, insulation and mechanical strength and useful for inner and outer trims for automobile, etc., by melting and kneading a polyester with a specific olefinic elastomer and a reaction accelerator at specific ratios. CONSTITUTION:The objective composition can be produced by melting and kneading (A) 2-50 pts.wt. of a polyester such as polybutylene terephthalate, (B) 98-50 pts.wt. of an olefinic elastomer modified with an unsaturated glycidyl compound and expressed by formula (R is H or 1-6C alkyl; Ar is 6-20C aromatic hydrocarbon group having one or more glycidyloxy groups; (n) is 1-4) and (C) 0.01-10 pts.wt. (based on 100 pts.wt. of A+B) of a reaction accelerator such as benzoyl peroxide.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a thermoplastic elastomer composition containing a polyester and an olefinic elastomer modified with a specific unsaturated glycidyl compound. More specifically, it is a heat that combines the properties of polyester and olefin elastomer and is suitable for interior and exterior parts of automobiles, industrial material parts such as belts and pipes, electric / communication parts, sports goods, and molded products such as home appliances. It relates to a plastic elastomer composition.

[0002]

2. Description of the Related Art A thermoplastic elastomer composition combining the properties of polyester, which is excellent in heat resistance, mechanical strength and insulation, with rubber elasticity has been developed as a high performance elastomer, and is used in the automobile industry, electric and electronic industries, etc. Is used for. Conventionally, as a thermoplastic elastomer containing polyester, there is a polyester-ether thermoplastic elastomer excellent in heat resistance having both heat resistance of polyester and moldability of polyether, but it has a high specific gravity and a large permanent elongation. It has drawbacks. On the other hand, the polyolefin-based thermoplastic elastomer has the characteristics of low specific gravity and small permanent elongation, but is not suitable for use at high temperatures because of its low softening point. Therefore, by blending a polyester having excellent heat resistance with the polyolefin-based thermoplastic elastomer, the heat resistance of the polyolefin-based thermoplastic elastomer is improved,
It is expected that a thermoplastic elastomer composition having excellent mechanical properties such as permanent elongation, which cannot be obtained by the polyester-ether type thermoplastic elastomer, light weight (low specific gravity) and good heat resistance can be obtained.

However, since the polyolefin elastomer has poor compatibility with polyester, the improvement of heat resistance and mechanical properties of the polyolefin thermoplastic elastomer composition containing polyester is insufficient. Therefore, an object of the present invention is to solve the drawbacks of conventional polyester-ether thermoplastic elastomers and polyolefin thermoplastic elastomers, and to provide a lightweight and excellent thermoplastic elastomer composition having the properties of polyester and olefin elastomers. To provide things.

[0004]

As a result of earnest research in view of the above object, the present inventors have used an olefin-based elastomer modified with a specific glycidyl compound having an acrylamide group and an epoxy group. By melt-kneading the system-based elastomer and the polyester in a specific ratio in the presence of the reaction accelerator, the polyester and the modified olefin-based elastomer are well compatibilized,
The present invention has been accomplished by finding that a thermoplastic elastomer composition having excellent heat resistance, which combines the characteristics of polyester and an olefin-based elastomer, and having a small permanent elongation and a low specific gravity can be obtained.

That is, the present invention comprises (a) 2 to 50 parts by weight of polyester, (b) the following general formula (1)

[0006]

[Chemical 2]

[In the formula, 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 n represents an integer of 1 to 4. ] 98 to 50 parts by weight of an olefinic elastomer modified with an unsaturated glycidyl compound represented by the following formula, and a total of 1 of (a) + (b)
It is a thermoplastic elastomer composition obtained by melt-kneading 0.01 to 10 parts by weight of the (c) reaction accelerator with respect to 00 parts by weight.

Hereinafter, the thermoplastic elastomer composition of the present invention will be described in detail. The (a) polyester of the thermoplastic elastomer composition component of the present invention is a thermoplastic resin generally obtained by polycondensation of a saturated dicarboxylic acid and a saturated dihydric alcohol, for example, polyethylene terephthalate,
Polypropylene terephthalate, polytetramethylene terephthalate (polybutylene terephthalate), polyhexamethylene terephthalate, polycyclohexane-
1,4-dimethylol terephthalate, polyneopentyl terephthalate, etc. are mentioned. Of these, polyethylene terephthalate and polybutylene terephthalate are preferred.

The polyester used in the present invention has an intrinsic viscosity [η] (dl / g) of 0.30 to 1.8 determined from the solution viscosity measured at 25 ° C. in an o-chlorophenol solvent,
The terminal carboxyl group preferably has a concentration of 10 to 200 meq / kg. For 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. In addition,
The terephthalic acid component in polyethylene terephthalate is
It may be substituted with an alkyl group or a halogen group,
The glycol component is 50 in addition to ethylene glycol.
Other glycols such as 1,4-butylene glycol, propylene glycol and hexamethylene glycol may be contained up to about wt%. In the case of polybutylene terephthalate, the intrinsic viscosity [η] is 0.30 to 1.8
And the terminal carboxyl group concentration is 10-200meq / kg
Are preferred. 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 1,4-butylene glycol or 5
Other glycols such as ethylene glycol, propylene glycol and hexamethylene glycol may be contained up to about 0% by weight.

In the modified olefin elastomer (b) modified with an unsaturated glycidyl compound, which is a component of the thermoplastic elastomer composition used in the present invention, the olefin elastomer used as the modifying raw material is ethylene, propylene, butene- 1, hexene-1, 4-methyl-pentene-1, etc. means a copolymer rubber with one or more α-olefins other than ethylene, and component (b) is an unmodified olefin elastomer. It may be contained up to about 50% by weight. Specific examples of the copolymer rubber with one or more α-olefins used in the present invention include ethylene-propylene copolymer rubber (EP
R), ethylene-butene copolymer rubber (EBR), ethylene-propylene-diene copolymer rubber (EPDM) and the like. Examples of the diene component in the ethylene-propylene-diene copolymer rubber (EPDM) include non-conjugated dienes such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene and methylenenorbornene,
Alternatively, a conjugated diene such as butadiene or isoprene may be used. The ethylene content in the olefin elastomer is preferably 5 to 95% by weight, more preferably 10 to 90.
% By weight. If the ethylene content is less than 5% by weight or more than 95% by weight, it becomes difficult to exhibit properties as an elastomer. The crystallinity of the olefin elastomer is preferably 40% by weight or less.

In the ethylene-propylene copolymer rubber (EPR) used in the present invention, the content of repeating units derived from ethylene is 50 to 80 mol%, and the content of repeating units derived from propylene is 20 to 20%. It is preferably 50 mol%. More preferably, the content of ethylene-based repeating units is 60 to 70 mol%, and the content of propyne-based repeating units is 30 to 40 mol%.
In addition, the EPR melt flow rate (MFR, 230
C., 2.16 kg load) is preferably in the range of 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 mol%. More preferably, the content of ethylene-based repeating units is 60 to 80 mol% and the content of butene-based repeating units is 20 to 40 mol%. Also, EB
The melt flow rate of R (MFR, 230 ° C., 2.16 kg load) is preferably in 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 (EPDM) has a repeating unit content of 40 to 70 mol% derived from ethylene, a repeating unit content of 30 to 60 mol% derived from propylene, and a diene-derived copolymer. The content of the repeating unit is preferably 1 to 10 mol%. More preferably, the content of ethylene-based repeating units is 50 to 60 mol%, the content of propylene-based repeating units is 40 to 50 mol%, and the content of diene-based repeating units is 3 to 6 mol%. .. In addition, EPDM melt flow rate (MFR, 230 ℃, 2.16kg load)
Is preferably in the range of 0.01 to 50 g / 10 minutes,
It is more preferably 0.1 to 30 g / 10 minutes.

The ethylene-propylene copolymer (EPR), the ethylene-butene copolymer rubber (EBR), and the ethylene-propylene-diene copolymer (EPDM) used in the present invention are within the range that does not impair the characteristics. Thus, other repeating units such as repeating units derived from other α-olefins such as 4-methylpentene-1 may be contained up to a proportion of 10 mol% or less.

In the present invention, it is also possible to use an olefin elastomer composition in which a polyolefin, preferably a crystalline polyolefin, is mixed with the above-mentioned olefin elastomer. As the crystalline polyolefin,
Ethylene, propylene, butene-1, hexene-1, 4
-Homopolymers of α-olefins such as methyl-pentene-1, non-elastomeric copolymers of ethylene and propylene or other α-olefins, or two or more non-elastomeric copolymers of these α-olefins A combination, a homopolymer of these homopolymers, a mixture of a homopolymer and a copolymer, and the like can be used. Of these polyolefins, polyethylene and polypropylene are preferred. Specific examples of polyethylene include low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and high density polyethylene (HDPE). When the polyolefin is mixed, the mixing amount is 80% by weight or less, preferably 50% by weight or less, based on the total amount of the olefin elastomer and the polyolefin (100% by weight). When the amount of the polyolefin mixed exceeds 80% by weight, the properties as an elastomer are lost.

The unsaturated glycidyl compound used for modifying the olefinic elastomer in the present invention means the following general formula (1) having an acrylamide group and an epoxy group in the molecule.

[0017]

[Chemical 3]

[Each symbol in the formula has the same meaning as described above. ] It is a glycidyl compound represented by these. Among the glycidyl compounds represented by the above general formula, the glycidyl compound represented by the following general formula (2) is particularly preferable.

[0019]

[Chemical 4]

[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. These glycidyl compounds are usually used alone, but two or more kinds can be used in combination.

Preferred modified olefin elastomers in the present invention are the above-mentioned raw material olefin elastomers, among which EPR, EBR or EPDM are glycidyl compounds represented by the general formula (1), particularly glycidyl compounds represented by the general formula (2). It has been modified with a compound. The content of the unsaturated glycidyl compound as a modifier of the modified olefin elastomer varies depending on the kind of the raw material olefin elastomer and cannot be said unconditionally, but is generally about 0.01 to 30% by weight, preferably
It is 0.1 to 10% by weight. If the content of the unsaturated glycidyl compound is less than 0.01% by weight, modification of the olefinic elastomer is insufficient, and if it exceeds 30% by weight, gelation occurs during blending with the polyester, resulting in poor moldability.

Such a preferable modified olefin elastomer 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 from commercially available products and used. As a specific example of the modification method, a modification example (graft polymerization) of the olefinic elastomer with the glycidyl compound is shown below. That is, in the melt-kneading method, an olefin elastomer, the glycidyl compound described above, and a catalyst as required are used, and these components are charged 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 about 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 modification is carried out while stirring at a temperature of about 90 to 200 ° C for 0.1 to 100 hours.
In any modification method, a usual radical polymerization catalyst can be used as a catalyst. The amount of the catalyst added is 0.1 to 10 relative to 100 parts by weight of the glycidyl compound for modification.
It is about part by weight.

As the (c) reaction accelerator used in the present invention, it is possible to use various peroxides and azo compounds which are used as catalysts in ordinary radical polymerization as in the case of modifying the above-mentioned olefin elastomer. it can. In particular,
Benzoyl peroxide, lauroyl peroxide, ditertiary butyl peroxide, acetyl peroxide, tert-butyl peroxybenzoic acid, dicumyl peroxide, peroxybenzoic acid, peroxyacetic acid, tertiary butyl peroxypivalate, 2,5-dimethyl-2 , 5-ditertiarybutylperoxyhexyne and other peroxides, α, α-
Examples thereof include azo compounds such as azobisisobutyronitrile. These are usually used alone, but two or more kinds may be used in combination.

Further, in the present invention, a crosslinking aid together with a reaction accelerator, such as divinylbenzene, 1,9-decadiene, 1,4-hexadiene, 7-methyloctadiene, 1,7-octadiene, ethylidene norbornene, etc. You may add and use the diene compound of. Of these diene compounds, divinylbenzene is preferred.

The mixing ratio of the respective components is such that (a) polyester and (b) modified olefin elastomer are in a weight ratio of (a) / (b) = 2/98 to 50/50, preferably 5
/ 95 to 50/50. If the weight ratio is less than 2/98, the amount of polyester is too small, and the effect of improving the heat resistance of the elastomer composition by using the polyester cannot be recognized.
On the other hand, if it exceeds 50/50, the amount of the modified olefin elastomer is too small, and the properties as an elastomer are lost. The (c) reaction accelerator is 0.01 to 10 parts by weight, preferably 100 parts by weight of (a) + (b).
It is 0.03 to 5 parts by weight. If it is less than 0.01 parts by weight, the effect of improving the compatibility between the polyester and the modified olefin elastomer by the use of the reaction accelerator is not recognized, and the use of more than 10 parts by weight is not economically disadvantageous. It causes gelation and causes deterioration of moldability.

In the present invention, in addition to the above-mentioned substances, other substances for the purpose of strengthening and modifying the thermoplastic elastomer composition, for example, fillers and reinforcing materials such as glass fibers, heat stabilizers, and light stabilizers. , Flame retardants, plasticizers, antistatic agents, foaming agents, nucleating agents, and the like can be added. The thermoplastic elastomer composition of the present invention can be obtained by melt-kneading the above components using a single-screw extruder, a twin-screw extruder, a Banbury mixer, a kneading roll, a kneader such as a Brabender, or the like. The kneading temperature varies depending on the type of polyester and modified olefin elastomer and cannot be generally specified, but is appropriately about 220 to 300 ° C, preferably 240 to 280 ° C. If the kneading temperature is lower than 220 ° C, the respective components are not sufficiently kneaded, and if the temperature exceeds 300 ° C, the thermoplastic elastomer composition may deteriorate.

In the present invention, the kneading order of each component is not particularly limited, and the components (a), (b) and (c) may be kneaded together, or the components (a) and (b) may be kneaded. After that, the component (c) may be kneaded. Furthermore, when a modified olefin elastomer containing an unmodified olefin elastomer is used as the component (b), the unmodified olefin elastomer and the modified olefin elastomer can be kneaded as independent components.
For example, unmodified olefin elastomer and component (a)
After kneading and, the modified olefin elastomer and the component (c) may be kneaded, or other kneading order may be adopted.

[0028]

The thermoplastic elastomer composition of the present invention comprises a polyester and an olefinic elastomer modified with a specific unsaturated glycidyl compound having an acrylamide group and an epoxy group in a specific ratio in the presence of a reaction accelerator. A thermoplastic elastomer composition which is obtained by melt-kneading, in which polyester and a modified olefin elastomer are well compatibilized, and which has excellent heat resistance and mechanical properties, particularly a high softening point, a small permanent elongation, and a light weight. Is. Although the detailed reason why the thermoplastic elastomer composition of the present invention exerts such an effect is not always clear, a modified olefin elastomer is obtained by the interaction between the unsaturated glycidyl compound component in the modified olefin elastomer and the reaction accelerator. It is considered that the cross-linking reaction occurs to increase the viscosity, and in this thickened state, the polyester and the modified olefin elastomer are compatibilized and cross-linked.

[0029]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. In each of the examples and comparative examples, the following materials were used as raw materials and additives. Polyester (1) Polyethylene terephthalate PET: [TR4550BH manufactured by Teijin Limited, intrinsic viscosity [η]
0.70 (in o-chlorophenol)] (2) Polybutylene terephthalate PBT: [C7000N manufactured by Teijin Limited, intrinsic viscosity [η]
1.05 (in o-chlorophenol)] olefin elastomer ethylene-propylene copolymer rubber EPR: [PO180 manufactured by Mitsui Petrochemical Co., Ltd., melt flow rate (MFR, 230 ° C., 2.16 kg load) 6.0 g / 1
0 minutes] Modification monomer AXE: glycidyl compound represented by the following chemical formula [Kanefuchi Chemical Industry Co., Ltd.]

[0030]

[Chemical 5]

[0031]Reaction accelerator  Dicumyl peroxide POX: Park Mill D [Made by NOF Corporation]Polyester-ether thermoplastic elastomer PEsEl: [Toyobo Co., Ltd. P280B, melt flow
-Rate (MFR, 230 ℃, 2.16kg load) 18.0g / 1
0 minutes]Polyolefin thermoplastic elastomer POEl: [Sumitomo Chemical Co., Ltd. TPE1500, melt flow
-Rate (MFR, 230 ° C, 2.16kg load) 0.1 g / 1
0 minutes]

Modified Olefin Elastomer (1) AXE Modified Olefin Elastomer (1) Ethylene-Propylene Copolymer Rubber [Melt Flow Rate (MFR, 230 ° C., 2.16 kg Load) 6.0 g / 10 min]
After 100 parts by weight, 3 parts by weight of AXE and 0.03 parts by weight of an organic peroxide [Perhexin 25B (manufactured by NOF CORPORATION)] were dry blended, the resulting mixture was blended with a uniaxial extruder having a diameter of 65 mm at 200 ° C. and 60 rpm. The mixture was melt-kneaded under the conditions to obtain a modified olefin elastomer (M-EPR-1) having a melt flow rate (MFR, 230 ° C., 2.16 kg load) of 2.8 g / 10 minutes. The AXE graft ratio of this modified olefin elastomer was 2.6% by weight. The graft ratio was calculated by the following method. The modified olefin elastomer is dissolved in boiling xylene, the insoluble matter is removed, and then the dissolved component is precipitated with methanol, and this is pressed to a thickness of about 50 μm, the IR spectrum is measured, and the C = O bond of AXE is measured. Expansion peak (16
It was calculated from the ratio of 48 cm ⁻¹ ) to one of the isotactic PP-specific peaks (840 cm ⁻¹ ).

(2) AXE-modified olefin elastomer (2) ethylene-propylene copolymer rubber [melt flow rate (MFR, 230 ° C., 2.16 kg load) 8.0 g / 10 min]
80 parts by weight and polyethylene (HDPE) [melt flow rate (MFR, 190 ° C, 2.16 kg load) 5.0 g / 1
0 minutes] 20 parts by weight, 3 parts by weight of AXE and organic peroxide [Perhexin 25B (manufactured by NOF Corporation)] 0.05
After dry blending parts by weight, this was melt-kneaded using a uniaxial extruder having a diameter of 65 mm at 200 ° C and 60 rpm to obtain a melt flow rate (MFR, 230 ° C, 2.16 kg).
A modified olefin elastomer (M-EPR-2) was obtained under a load of 4.9 g / 10 minutes. The AXE graft ratio of this modified olefin elastomer was 2.3% by weight. The graft ratio was determined in the same manner as in the case of M-EPR-1.

Examples 1-12 and Comparative Examples 1-8 Reaction with polyester (PET or PBT), olefin elastomer (EPR), modified olefin elastomer (M-EPR-1 or M-EPR-2) After dry blending with the accelerator (POX) in a ratio shown in Table 1 by a Henschel mixer, it was 28 when PET was used by a twin screw extruder (L / D = 30) with a diameter of 45 mm.
200 ℃ at 0 ℃ and 250 ℃ when using PBT
Melt kneading at rpm to obtain pellets of the thermoplastic elastomer composition. The thermoplastic elastomer composition thus obtained was injection-molded, and the specific gravity, Vicat softening point, surface hardness, permanent elongation, and elongation at break of the molded product were measured. The results are shown in Table 1.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

The methods for measuring the physical properties shown in Table 1 above are as follows. (1) Specific gravity: Measured according to JIS K6911. (2) Vicat softening point: measured according to ASTM D1525. (3) Surface hardness (23 ° C.): Shore D hardness was measured according to ASTM D2240. (4) Permanent elongation (23 ℃): 100% based on JISK6301
Evaluation by extension. (5) Elongation at break (23 ° C.): Measured according to JIS K6301.

As is clear from Table 1, the softening point of the composition comprising polyester and an unmodified olefin elastomer (Comparative Example 5) was the same as that of the commercially available polyolefin thermoplastic elastomer containing no polyester (Comparative Example 4). ) Is the same level as the softening point, and no improvement in heat resistance due to the blending of polyester (Comparative Examples 1 and 2) is observed. Further, the elongation as a breaking point is low and the properties as an elastomer are deteriorated as is apparent from the fact that the permanent elongation cannot be measured,
It can be seen that the compatibility of polyester and olefin elastomer is poor. Further, the compositions (Comparative Examples 6 to 8) composed of a polyester lacking a reaction accelerator (POX) and a modified olefin elastomer have improved properties as an elastomer, but still have a low softening point,
It can be seen that the compatibility between the polyester and the modified olefin elastomer is poor.

On the other hand, the thermoplastic elastomer composition of the present invention comprises a commercially available polyolefin-based thermoplastic elastomer containing no polyester (Comparative Example 4) and a thermoplastic elastomer composed of polyester and an unmodified olefin-based elastomer (comparative). Compared with Example 5), and compositions comprising a polyester lacking a reaction accelerator (POX) and a modified olefin elastomer (Comparative Examples 6 to 8), the softening point, surface hardness, permanent elongation, and elongation at break. Has a good balance of all physical properties, and the improvement of the softening point is remarkable. Further, the specific gravity is lower than that of the polyester-polyether thermoplastic elastomer (Comparative Example 3), and the permanent elongation is remarkably improved.

[0041]

As described above, the thermoplastic elastomer composition of the present invention is a reaction accelerator comprising a polyester and an olefin elastomer modified with a specific unsaturated glycidyl compound having an acrylamide group and an epoxy group. Which is obtained by melt-kneading in the presence of, the polyester and the modified olefin-based elastomer are well compatibilized, have the properties of the polyester and the olefin-based elastomer, and have excellent heat resistance and mechanical properties,
It has a low specific gravity. Such a thermoplastic elastomer composition of the present invention is an elastomer composition for various engineering elastomers, especially for interior and exterior parts of automobiles, industrial material parts such as belts and pipes, electric / communication parts, sports equipment, home appliances, etc. It is suitable as a product.

Continuation of the front page (72) Inventor Yuji Fujita 1-3-1 Nishitsurugaoka, Oi-cho, Iruma-gun, Saitama Inside Tonen Research Institute

Claims (1)

[Claims] 1. (a) 2 to 50 parts by weight of polyester,
(B) The following general formula (1): [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 is 1
Represents an integer of ~ 4. ] The olefin elastomer 98-5 modified with the unsaturated glycidyl compound represented by
A thermoplastic elastomer composition obtained by melt-kneading 0.01 to 10 parts by weight of (c) a reaction accelerator with respect to 0 parts by weight and a total of 100 parts by weight of (a) + (b).