JP2003231781A - Thermoplastic elastomer composition and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic elastomer composition which can produce a molded article excellent in an appearance in an injection molding, and a method of manufacturing the composition. <P>SOLUTION: The thermoplastic elastomer composition is obtained by dynamically heat-treating a composition comprising the following ingredients (a) to (d): ingredient (a): an olefin rubber, ingredient (b): an olefin resin, ingredient (c): an organic peroxide, the one min half-life temperature of which exceeds 160°C, and ingredient (d): an organic peroxide, the one min half-life temperature of which is at most 160°C. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a thermoplastic elastomer composition and a method for producing the composition. More specifically, the present invention relates to a thermoplastic elastomer composition capable of obtaining an injection-molded article having an excellent appearance and a method for producing the composition.

[0002]

2. Description of the Related Art A thermoplastic elastomer composition obtained by dynamic heat treatment of a resin composition consisting of an olefin resin, an olefin rubber and an organic peroxide is relatively inexpensive and has an appropriate flexibility. Since it has, the injection molding of the thermoplastic elastomer composition can be used for automobile parts, various industrial parts, various civil engineering building materials, housings, OA parts,
It is used in fields such as sundries. For example, Japanese Patent Laid-Open No. 8-
Japanese Patent Publication No. 197538 describes an injection-molded article made of a thermoplastic elastomer composition obtained by dynamically heat-treating an ethylene-propylene-ethylidene norbornene copolymer rubber, polypropylene and a bismaleimide compound.
Conventionally, such a molded body was often used after being coated, but recently, from the viewpoint of economy and productivity, the demand for no coating of the molded body has been increased, and the appearance is excellent even without coating. A molded body is required.

[0003]

However, in the case of the injection-molded article made of the conventional thermoplastic elastomer composition, the satisfactory appearance may not be obtained in some cases.
Under such circumstances, the problem to be solved by the present invention is to provide a thermoplastic elastomer composition capable of obtaining a molded article having an excellent appearance in injection molding and a method for producing the composition.

[0004]

That is, the first aspect of the present invention relates to a thermoplastic elastomer composition obtained by dynamically heat treating a composition containing the following components (a) to (d). . (A): Olefin-based rubber (b): Olefin-based resin (c): Organic peroxide having a one-minute half-life temperature exceeding 160 ° C (d): Organic peroxide having a one-minute half-life temperature of 160 ° C or less The second aspect of the present invention relates to a thermoplastic elastomer composition obtained by dynamic heat treatment of a composition containing the above components (a) to (d) and the following component (e). (E): Cross-linking aid Furthermore, the third aspect of the present invention relates to a method for producing the thermoplastic elastomer composition.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The olefin rubber (a) used in the present invention means ethylene, propylene, 1-butene,
1 to 2 carbon atoms such as 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene and 1-decene
A polymer containing repeating units derived from one or more olefins of No. 0 according to ASTM D22
A polymer having a Shore A of 99 or less measured according to 40. The olefin rubber (a) may contain a repeating unit derived from a monomer other than an olefin, for example, a repeating unit derived from a non-conjugated diene. As the non-conjugated diene, 1,
Chain-like non-conjugated dienes such as 4-hexadiene, 1,6-octadiene, 2-methyl-1,5-hexadiene, 6-methyl-1,5-heptadiene, 7-methyl-1,6-octadiene; cyclohexadiene, Dicyclopentadiene, methyltetrahydroindene, 5-vinylnorbornene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-
Cyclic non-conjugated dienes such as norbornene and 6-chloromethyl-5-isopropenyl-2-norbornene; 2,3-
Trienes such as diisopropylidene-5-norbornene, 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, 1,3,7-octatriene and 1,4,9-decatriene. And so on. These are 1 or 2
Used in combination of two or more species.

Examples of the olefin rubber (a) include ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, ethylene- Propylene-
1-butene copolymer, ethylene-propylene-1-hexene copolymer, ethylene-propylene-1-octene copolymer, ethylene-propylene-5-ethylidene-2-
Examples thereof include norbornene copolymers and propylene-1-butene copolymers, which may be used alone or in combination of two or more. Moreover, these can be manufactured by a well-known method.

Among the olefin rubbers (a), ethylene rubbers containing repeating units derived from ethylene are preferable from the viewpoint of increasing the strength of the molded product, and ethylene-α-olefin copolymers and ethylene-α are preferred. -Olefin-non-conjugated diene copolymer is more preferable, ethylene-
The α-olefin-non-conjugated diene copolymer is more preferable. Here, as the α-olefin, from the viewpoint of easy availability, propylene, 1-butene, 1-pentene, 1-
Hexene and 1-octene are preferable, and propylene is more preferable. As the non-conjugated diene, 5-ethylidene-2-norbornene and dicyclopentadiene are preferable from the viewpoint of easy availability.

The content of the repeating unit derived from the α-olefin of the ethylene rubber is preferably 10 to 50% by weight, more preferably 20 to 40% by weight, from the viewpoint of flexibility.

The content of the non-conjugated diene in the ethylene-α-olefin-non-conjugated diene copolymer is usually 5 in terms of iodine value.
40.

As the olefin rubber (a), an oil-extended olefin rubber to which a mineral oil softener is added may be used. When the oil-extended olefin rubber is used, the content of the extender oil is usually 20 to 100 parts by weight of the olefin rubber.
It is 150 parts by weight. As the mineral oil-based softening agent, it is possible to use an extension oil that is usually used for adjusting an oil-extended rubber. Minutes (average molecular weight of 300 to 1500, pour point of 0 ° C. or lower) can be used. Of these, paraffinic mineral oils are preferred.

The Mooney viscosity (ML _{1 + 4} 100 ° C.) of the olefin rubber (a) at 100 ° C. is preferably 5 to 150 from the viewpoint of enhancing the strength of the molded product and further enhancing the appearance of the molded product. , More preferably 20 to 100
Is. Here, the Mooney viscosity (ML _{1 + 4} 100 ° C.) at 100 ° C. of the olefin rubber (a) is ASTM D-9.
Measured at 100 ° C according to 27-57T. In addition,
When an oil-extended olefin rubber is used as the olefin rubber (a), the Mooney viscosity of the oil-extended olefin rubber is the Mooney viscosity of the olefin rubber.

The olefin resin (b) used in the present invention is ethylene, propylene, 1-butene, 1-
Pentene, 1-hexene, 4-methyl-1-pentene,
A polymer containing repeating units derived from one or more olefins having 2 to 10 carbon atoms, such as 1-octene and 1-decene, according to JIS K-7121.
The polymer has a maximum melting peak temperature of 80 ° C. or higher measured according to JIS K-7203 and a flexural modulus of 50 MPa or higher measured according to JIS K-7203.

Examples of the olefin resin (b) include ethylene homopolymer, propylene homopolymer, 1-
Butene homopolymer, ethylene-propylene copolymer, ethylene-1-butene copolymer, ethylene-1-hexene copolymer, ethylene-1-octene copolymer, propylene-1-butene copolymer, propylene- 1-hexene copolymer, propylene-1-octene copolymer, ethylene-propylene-1-butene copolymer, ethylene-propylene-1-hexene copolymer, ethylene-propylene-
Examples thereof include 1-octene copolymers, which may be used alone or in combination of two or more. Moreover, these can be manufactured by a well-known method.

Among the olefin resins (b), a propylene polymer containing a repeating unit derived from propylene is preferable from the viewpoint of improving heat resistance. Examples of the propylene-based polymer include propylene homopolymer, propylene-ethylene random copolymer, propylene-ethylene block copolymer and the like. When a propylene homopolymer is used, a propylene homopolymer having high crystallinity is preferable in order to obtain a molded product having high rigidity. On the other hand, when a propylene-ethylene random copolymer is used, a propylene-ethylene random copolymer having a low ethylene unit content and high crystallinity is preferable for obtaining a molded product having high rigidity, and a molded product having low rigidity. In order to obtain the above, a propylene-ethylene random copolymer having a large ethylene unit content and low crystallinity is preferable. The propylene-ethylene block copolymer is composed of a first segment and a second segment, the first segment is a propylene homopolymer part, the second segment is a propylene-ethylene random copolymer part block copolymer There is a propylene-ethylene random copolymer having a different ethylene content as the first segment or the second segment. Further, the content of the propylene-ethylene random copolymer part which is the second segment is 30% by weight.
The reactor olefin-based thermoplastic elastomer (R-TPO) described above may be used.

The melt flow rate (MFR) of the olefin resin (b) is preferably 0.1 to 0.1 from the viewpoint of enhancing the strength of the molded product and further enhancing the appearance of the molded product.
150 g / 10 minutes, more preferably 1-100 g
/ 10 minutes. Here, the melt flow rate (MFR) of the olefin resin (b) is JIS K-7210.
According to (1999), temperature 230 ° C, load 21.18
Measured in N.

Examples of the organic peroxides used in the present invention include ketone peroxides, diacyl peroxides, hydroperoxides, dialkyl peroxides, peroxyketals, alkyl peresters, percarbonates, and peroxides. Known organic peroxides such as oxydicarbonates and peroxyesters can be used.

As the organic peroxide (c) having a one-minute half-life temperature exceeding 160 ° C., dicumyl peroxide,
2,5-Dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne, 1,3-bis (t-butylperoxy) (Oxyisopropyl) benzene, t-butylcumyl peroxide, di-t-butylperoxide, 2,
2,4-trimethylpentyl-2-hydroperoxide, diisopropylbenzohydroperoxide,
Cumene peroxide, t-butyl peroxide and the like are mentioned, and these may be used alone or in combination of two or more kinds.

As the organic peroxide (d) having a one-minute half-life temperature of 160 ° C. or less, 1,1-di (t-butylperoxy) 3,5,5-trimethylcyclohexane,
1,1-di-t-butylperoxycyclohexane, isobutyl peroxide, 2,4-dichlorobenzoyl peroxide, o-methylbenzoyl peroxide, bis-3,5,5-trimethylhexanoyl peroxide, lauroyl peroxide , Benzoyl peroxide, p-chlorobenzoyl peroxide, and the like, and these may be used alone or in combination of two or more.

A crosslinking aid (e) may be added to the composition containing the components (a) to (d) used in the present invention. The crosslinking aid (e) is preferably a compound having two or more double bonds in the molecular structure, and examples thereof include N, N-m-phenylene bismaleimide, toluylene bismaleimide,
Examples thereof include p-quinonedioxime, nitrosobenzene, diphenylguanidine, trimethylolpropane, trimethylolpropane trimethacrylate, and divinylbenzene, and these may be used alone or in combination of two or more.

In the composition containing the components (a) to (d) used in the present invention, the content of the olefin rubber (a) is preferably 95 to 40% by weight, and the olefin resin (b). The content of is preferably 5 to 60% by weight
The content of the olefin rubber (a) is more preferably 90 to 60% by weight, and the content of the olefin resin (b) is more preferably 10 to 40% by weight. However, the total amount of the olefin rubber (a) and the olefin resin (b) is 100% by weight. From the viewpoint of enhancing flexibility, it is preferable that the content of the olefin rubber (a) is high, and from the viewpoint of further enhancing the appearance of the molded body,
It is preferable that the content of the olefin resin (b) is high.

In the composition containing the components (a) to (d) used in the present invention, the one-minute half-life temperature is 160 ° C.
The content of the organic peroxide (c) exceeding 100 is a total amount of the olefin rubber (a) and the olefin resin (b) of 100 from the viewpoint of further enhancing the strength of the molded body and the appearance of the molded body.
It is preferably 0.01 to 10 parts by weight with respect to parts by weight. Further, the content of the organic peroxide (d) having a 1-minute half-life temperature of 160 ° C. or lower is the sum of the olefin rubber (a) and the olefin resin (b) from the viewpoint of further enhancing the appearance of the molded body. The amount is preferably 0.0 with respect to 100 parts by weight.
It is from 01 to 0.1 part by weight.

In the composition containing the components (a) to (d) used in the present invention, the content of the crosslinking aid (e) is
It is preferably 0.01 to 10 parts by weight with respect to 100 parts by weight of the total amount of the olefin rubber (a) and the olefin resin (b). By adding the crosslinking aid (e), the strength of the molded product can be increased, but if the content is too large, the productivity may decrease.

The thermoplastic elastomer composition of the present invention comprises
Inorganic fillers (talc, calcium carbonate, calcined kaolin, etc.), organic fillers (fiber, wood flour,
Cellulose powder etc.), lubricant (fatty acid amide, silicone etc.), antioxidant (phenolic, sulfur based,
Phosphorus, lactone, vitamin, etc.), weather resistance stabilizer, ultraviolet absorber (benzotriazole, tridiamine,
Anilides, benzophenones, etc.), heat stabilizers, light stabilizers (hindered amines, benzoates, etc.), antistatic agents, nucleating agents, pigments and other additives may be added. These additives may be blended before the dynamic heat treatment or after the dynamic heat treatment.

The dynamic heat treatment of the present invention is to melt-knead the olefin rubber (a) and the olefin resin (b) in the presence of an organic peroxide. As the kneading device used for the dynamic heat treatment, a continuous kneader and / or a batch kneader can be used. Examples of the continuous kneader include a single screw extruder kneader and a twin screw extruder kneader.
Of these, a twin-screw extrusion kneader is preferable. Examples of the batch type kneader include a kneader and a Banbury mixer. Among these, the Banbury mixer is preferable.

The thermoplastic elastomer composition of the present invention comprises
It may be produced by collectively melt-kneading all the components to be subjected to the dynamic heat treatment, or the components not selected after melt-kneading a part of the components to be subjected to the dynamic heat treatment. It may be produced by adding and kneading.

As the method for producing the thermoplastic elastomer of the present invention, a production method satisfying the following requirements (1) and (2) is preferable from the viewpoint of further enhancing the appearance of the molded article. (1): Simultaneously with the start of the dynamic heat treatment of the component (a), or
Starting the dynamic heat treatment of the component (b) after starting the dynamic heat treatment of the component (a) (2): simultaneously with the start of the dynamic heat treatment of the component (d) or the start of the dynamic heat treatment of the component (d). Later, component (c)
Starting dynamic heat treatment by

As a manufacturing method that satisfies the requirements (1) and (2), for example, the following manufacturing method can be given. Production method 1: A production method in which the components (a) to (d) are collectively melt-kneaded by a kneader. The additives and the like may be added either during the process or after the completion of all the processes. Production method 2: After melt-kneading the component (a), the component (b) and the component (d) with a kneader, the component (c) is added to the melt-kneaded product of the component (a), the component (b) and the component (d). A manufacturing method of adding and melt-kneading. The additives and the like may be added either during the process or after the completion of all the processes. Manufacturing method 3: After melt-kneading the component (a) and the component (d) with a kneader, the component (b) and the component (c) are added to the melt-kneaded product of the component (a) and the component (d), and the melt-kneading is performed. Manufacturing method. The additives and the like may be added either during the process or after the completion of all the processes.

When the crosslinking aid (e) is used for producing the thermoplastic elastomer of the present invention, a production method satisfying the following requirement (3) in addition to the above requirements (1) and (2) is
It is preferable from the viewpoint of further enhancing the appearance of the molded body. (3): Simultaneously with the addition of the component (d), the component (c)
Adding component (e) before adding

As a manufacturing method satisfying the requirements (1) to (3), for example, the following manufacturing method can be mentioned. Production method 4: A production method in which the components (a) to (e) are melt-kneaded together in a kneader. The additives and the like may be added either during the process or after the completion of all the processes. Production method 5: Component (a), component (b), component (d) and component (e) are melt-kneaded in a kneader and then component (a), component (b), component (d) and component (e). A manufacturing method in which the component (c) is added to the melt-kneaded product, and melt-kneaded. The additives and the like may be added either during the process or after the completion of all the processes. Production method 6: After melt-kneading the component (a), the component (b) and the component (d) in a kneader, the component (e) is added to the melt-kneaded product of the component (a), the component (b) and the component (d). A production method in which the components are added and melt-kneaded, and then the component (c) is added to the melt-kneaded product of the component (a), the component (b), the component (d) and the component (e), and the mixture is melt-kneaded. The additives and the like may be added either during the process or after the completion of all the processes. Production method 7: After melt-kneading the component (a), the component (d) and the component (e) with a kneader, the component (b) is added to the melt-kneaded product of the component (a), the component (d) and the component (e). A manufacturing method in which the component (c) is added and melt kneading is performed. The additives and the like may be added either during the process or after the completion of all the processes. Production method 8: After melt-kneading the component (a) and the component (e) with a kneader, the component (d) is added to the melt-kneaded product of the component (a) and the component (e) to perform melt-kneading. A manufacturing method in which the component (b) and the component (c) are added to a melt-kneaded product of the component (a), the component (d) and the component (e) and the mixture is melt-kneaded. The additives and the like may be added either during the process or after the completion of all the processes. Manufacturing method 9: After melt-kneading the component (a) and the component (d) with a kneader, the component (e) is added to the melt-kneaded product of the component (a) and the component (d) to perform melt-kneading. A manufacturing method in which the component (b) and the component (c) are added to a melt-kneaded product of the component (a), the component (d) and the component (e) and the mixture is melt-kneaded. The additives and the like may be added either during the process or after the completion of all the processes.

The thermoplastic elastomer composition of the present invention comprises
Various molding methods such as injection molding, extrusion molding, hollow molding, vacuum molding, and calendar molding are used to mold various molded products, and among these, it is suitable for injection molding.

The molded article comprising the thermoplastic elastomer composition of the present invention is used for parts of automobiles, trains, ships, home appliances, buildings, etc .; stationery; medical instruments, etc., and as automobile parts, mudguards, airbag covers. , Armrests, console boxes, shift levers, slide covers, shelf covers, brake covers, etc.

[0032]

EXAMPLES Next, the present invention will be explained by examples. [1] Evaluation method (1) Appearance of injection-molded sheet A flat plate having a thickness of 2 mm and a size of 150 mm × 90 mm was molded using an injection molding machine at a cylinder temperature of 220 ° C. and a mold temperature of 50 ° C. The surface was visually evaluated as follows. ◯: Appearance is good with no flow marks or spots ×: Appearance is poor with flow marks and / or spots

[2] Raw material (a) Olefin rubber Sumitomo Chemical Co., Ltd. Esprane 670F (ethylene-propylene copolymer) (b) Olefin resin Sumitomo Chemical Co., Ltd. Noblene HR100XG
(Polypropylene) (c) Organic peroxide having a one-minute half-life temperature of more than 160 ° C Sanperox-YPO (2,5-) manufactured by Sanken Kako Co., Ltd.
Dimethyl-2,5-di (t-butylperoxy) hexine) (d) Organic peroxides having a one-minute half-life temperature of 160 ° C. or less Sanperox-CY-1.1
(1,1-di (t-butylperoxy) 3,5,5-trimethylcyclohexane) (e) Crosslinking agent Sumitomo Chemical Co., Ltd. Sumifine BM (N, N
-M-phenylene bismaleimide)

[3] Preparation of Thermoplastic Elastomer Composition Example 1 and Comparative Example 1 Bale-like olefinic rubber was put into a Banbury mixer (internal volume 16 L), pulverized and kneaded at a rotor rotation speed of 68 rpm for 1 minute at room temperature. The olefin resin, the organic peroxide and the crosslinking aid were added to the Banbury mixer so that the blending amounts shown in Table 1 were obtained, melt kneading was performed, and a dynamically heat-treated thermoplastic elastomer composition was obtained. It was At this time, the total filling amount was 11 kg, and as the melt-kneading conditions, the rotor rotation speed was 68 rpm, the chamber temperature was a temperature at which the olefin resin was melted in about 2 minutes from the start of the melt-kneading, and the kneading time was 6 minutes. did. Table 1 shows the evaluation results of the obtained thermoplastic elastomer composition.

[0035]

[Table 1]

[0036]

As described above, according to the present invention, it is possible to provide a thermoplastic elastomer composition capable of obtaining a molded article having an excellent appearance in injection molding and a method for producing the composition. Further, the thermoplastic elastomer composition of the present invention can be excellent in strength, flexibility and heat resistance.
INDUSTRIAL APPLICABILITY The thermoplastic elastomer composition of the present invention can be used for parts such as automobiles, trains, ships, home appliances, and buildings; stationery; medical instruments and the like.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F070 AA12 AA13 AA15 AA16 AC56                       AE08 GB08                 4J002 BB03X BB05W BB05X BB12X                       BB15W BB15X BB17X BP02X                       FD010 FD030 FD040 FD050                       FD070 FD140 FD150 FD170                       GC00 GL00 GN00

Claims (7)

[Claims] 1. A thermoplastic elastomer composition obtained by dynamic heat treatment of a composition containing the following components (a) to (d). (A): Olefin-based rubber (b): Olefin-based resin (c): Organic peroxide having a one-minute half-life temperature exceeding 160 ° C (d): Organic peroxide having a one-minute half-life temperature of 160 ° C or less object 2. The thermoplastic elastomer composition according to claim 1, which is obtained by dynamic heat treatment of a composition containing the components (a) to (d) according to claim 1 and the following component (e). (E): Crosslinking aid 3. A composition containing components (a) to (d), wherein the total amount of component (a) and component (b) is 100% by weight.
On the other hand, the thermoplastic elastomer composition according to claim 1, wherein the content of the component (a) is 95 to 40% by weight and the content of the component (b) is 5 to 60% by weight. 4. The thermoplastic elastomer composition according to claim 1, wherein the olefin rubber is ethylene rubber and the olefin resin is propylene resin. 5. The thermoplastic elastomer composition according to claim 1, which is for injection molding. 6. The method for producing a thermoplastic elastomer composition according to claim 1, wherein the dynamic heat treatment satisfies the following requirements (1) and (2). (1): Simultaneously with the start of the dynamic heat treatment of the component (a), or
Starting the dynamic heat treatment of the component (b) after starting the dynamic heat treatment of the component (a) (2): simultaneously with the start of the dynamic heat treatment of the component (d) or the start of the dynamic heat treatment of the component (d). Later, component (c)
Starting dynamic heat treatment by 7. The method for producing a thermoplastic elastomer composition according to claim 2, wherein the dynamic heat treatment satisfies the requirements (1) and (2) of claim 6 and the following requirement (3). (3): Starting the dynamic heat treatment with the component (d) in the presence of the component (e), or starting the dynamic heat treatment with the component (c) in the presence of the component (e).