JP2002003664A - Polyolefin thermoplastic elastomer for lamination - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polyolefin thermoplastic elastomer for lamination which has a good adhessiveness to a polyolefin resin. SOLUTION: This polyolefin thermoplastic elastomer for laminating on the polyolefin resin comprises (A) a partially or completely crosslinked ethylene.&alpha;- olefin copolymer comprising mainly ethylene and &alpha;-olefin copolymer having carbons of 3-20 (B) a polyolefin resin (C) a dynamically vulcanized polyolefin thermoplastic elastomer having oil for rubber as a main component. The ethylene.&alpha;-olefin copolymer has a copolymerization ratio of 20-60 wt.%, a density of <0.880 g/cm3, and a content of oil for rubber of <40 pts.wt, based on the ethylene.&alpha;-olefin copolymer of 100 pts.wt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminating thermoplastic elastomer having good adhesion to a polyolefin resin.

[0002]

2. Description of the Related Art Conventionally, resins are widely used in various fields such as automotive materials, building materials, tools and the like. These resins are generally hard resins. However, depending on the application, it is necessary to improve the feel when touched by human hands or to prevent injury or damage to the material even when touched by humans. It is coated with an elastomer. In the method of softening the surface of such a hard resin with a soft resin or an elastomer, the mutual materials are usually different in many cases. Therefore, a primer, an adhesive or the like is applied to the surface of the hard resin, and then the soft material is softened. It is carried out by a method such as attaching a resin or an elastomer or insert molding. However,
In such a method, there is a problem that the lamination is troublesome and, for example, when the laminated product is to be recycled, the hard resin and the soft resin or the elastomer must be peeled off.

There is a trend toward resin integration from the viewpoint of world recycling and the like. For example, polypropylene resin is becoming the main resin used for automobiles. There is also a demand for softening the surface of a polypropylene-based resin in order to improve the feel when touched by human hands, particularly in interior materials for automobiles. In addition, polyamide resins have been used for tools such as housings of power tools.However, polyamide resins absorb water because of easy absorption of water, dimensional change due to humidity and poor dimensional stability or high specific gravity. It is shifting to a polypropylene resin having a low property and a low specific gravity. Even with this tool, there is a demand for softening the surface of the polypropylene resin in order to improve the feel when touched by human hands.

[0004] In order to soften the surface of products made of these polypropylene resins, an elastomer containing the same component as the main component should basically exhibit good adhesiveness. However, when the same component is used as a main component, it becomes possible to add a reinforcing material and the like and to reuse it as a base material without peeling. As the elastomer for softening the surface of a product made of a polypropylene resin, the same component, that is, a dynamically crosslinked polyolefin-based thermoplastic elastomer containing a polypropylene resin as a matrix component is a possible candidate. The dynamically crosslinked polyolefin-based thermoplastic elastomer is described in JP-A-9-137001, JP-A-10-87912, and the like. However, ethylene / α-olefin-based copolymer (for example, ethylene Octene-1 copolymer, ethylene-propylene-diene copolymer, etc.), polypropylene and rubber oil are crosslinked rubber components with an extruder in the presence of a radical initiator and a crosslinking aid, etc. It has excellent properties such as heat resistance. However, when a polypropylene-based resin molded product is loaded in a mold and then this dynamically crosslinked polyolefin-based thermoplastic elastomer is insert-molded, there is a problem that adhesion is poor at present and it cannot be used practically. Even in such insert molding, there is a demand to develop a dynamically crosslinked polyolefin-based thermoplastic elastomer having excellent adhesion to a polyolefin-based resin as a base material.

[0005]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention provides a dynamically crosslinked polyolefin-based thermoplastic elastomer which exhibits good adhesion to a polyolefin-based resin, especially a polypropylene-based resin even in insert molding. It is the purpose.

[0006]

Means for Solving the Problems The present inventors have conducted intensive studies to provide a polyolefin-based thermoplastic elastomer for laminating a polyolefin-based resin having excellent adhesion to a polyolefin-based resin. As the polyolefin-based thermoplastic elastomer, the study focused on a dynamically crosslinked polyolefin-based thermoplastic elastomer having excellent compression set and heat resistance. The lower the hardness of the polyolefin-based thermoplastic elastomer laminated to the polyolefin-based resin, the better the feel when touched by a human hand, or the lowest possible as it is less injured and the material is damaged even by human contact. hardness,
It is necessary that the Shore A hardness is preferably 75 or less, more preferably 70 or less. However, the composition of such a low-hardness, dynamically crosslinked polyolefin-based thermoplastic elastomer currently has extremely poor adhesion to a polyolefin-based resin.

As a result of intensive studies to clarify the reason, the following has been found. That is, the dynamically crosslinked polyolefin-based thermoplastic elastomer is usually ethylene.
It is produced by dynamically crosslinking three components of an α-olefin copolymer, a polyolefin resin and a rubber oil in the presence of a radical initiator and a crosslinking aid. In this case, the Shore hardness A of the ethylene / α-olefin copolymer used as a raw material is usually around 70 to 80 in many cases. Dynamically crosslinked polyolefin-based thermoplastic elastomers have a structure in which the polyolefin resin serves as a matrix and the crosslinked rubber is finely dispersed in the polyolefin resin. The Shore A hardness of the polyolefin-based thermoplastic elastomer does not become 70 or less. For this purpose, a large amount of rubber oil is added and included in the crosslinked rubber, thereby lowering the hardness of the crosslinked rubber itself and increasing the Shore A hardness of the final product of the dynamically crosslinked polyolefin thermoplastic elastomer to 70. It is as follows. Inserting a dynamically crosslinked polyolefin-based thermoplastic elastomer containing a large amount of rubber oil into the polyolefin-based resin loaded in the mold causes oil to be present at the interface between the polyolefin-based resin and the dynamically crosslinked polyolefin-based thermoplastic elastomer. It was found that this was caused by lowering the adhesion.

[0008] As a result, a polyolefin-based thermoplastic elastomer is used only when an ethylene / α-olefin-based copolymer rubber having a limited range of properties is used and a dynamic cross-linked polyolefin-based thermoplastic elastomer is used as an oil of a certain amount or less. The present inventors have found that a material for lamination having good adhesion to a resin and low hardness can be obtained, and the present invention has been completed. That is, the present invention provides (A) an ethylene / α-olefin-based copolymer mainly composed of partially or completely crosslinked ethylene and an α-olefin having 3 to 20 carbon atoms, (B) a polyolefin-based resin and C) a dynamically crosslinked polyolefin-based thermoplastic elastomer mainly composed of rubber oil,
The ethylene / α-olefin copolymer has an α-olefin copolymerization ratio of 20 to 60% by weight and a density of 0.88%.
0 g / cm and less than ³ and a polyolefin resin laminating polyolefin heat, wherein the content of the rubber oil is less than 40 parts by weight relative to the ethylene · alpha-olefin copolymer 100 parts by weight It relates to a plastic elastomer.

Hereinafter, the present invention will be described in detail. First, each component of the present invention will be described in detail. The ethylene / α-olefin-based copolymer as the component (A) in the polyolefin-based thermoplastic elastomer of the present invention is an ethylene / α-olefin-based copolymer mainly composed of ethylene and an α-olefin having 3 to 20 carbon atoms. It is united. 3 to 2 carbon atoms
Examples of the α-olefin of 0 include propylene, butene-1, pentene-1, hexene-1, 4-methylpentene-1, heptene-1, octene-1, and nonene-.
1, decene-1, undecene-1, dodecene-1 and the like. These α-olefins may be used alone or in combination of two or more. Further, a copolymer component may be included as the third component. Examples of the copolymerization component of the third component include conjugated dienes such as 1,3-butadiene and isoprene, and non-conjugated dienes such as dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, and ethylidene norbornene.
However, as the ethylene / α-olefin-based copolymer, the ethylene / α-olefin-based copolymer obtained by copolymerizing a conjugated diene or a non-conjugated diene is not excluded. When used as an interior material or a tool, the elastomer needs to have good weather resistance in order to come to the outermost surface. When used in such applications, the conjugated diene and / or non-conjugated diene to be copolymerized is as little or as little as possible.
-An olefin copolymer is excellent in weather resistance and is more preferable. The ethylene / α-olefin-based copolymer which is the component (A) in the polyolefin-based thermoplastic elastomer of the present invention is preferably produced using a metallocene-based catalyst.

In general, a metallocene catalyst is composed of a cyclopentadienyl derivative of a Group IV metal such as titanium or zirconium and a cocatalyst, and is not only highly active as a polymerization catalyst but also has a higher activity than a Ziegler catalyst. The molecular weight distribution of the resulting polymer is narrow, and the distribution of the comonomer α-olefin having 3 to 20 carbon atoms in the copolymer is uniform.
For this reason, the polymer obtained with the metallocene-based catalyst has a more uniform cross-linking and exhibits excellent rubber elasticity.

The object of the present invention is to provide a polyolefin-based thermoplastic elastomer having excellent adhesion to a polyolefin-based resin and low hardness. Therefore, even if the rubber oil is added in a small amount, the polyolefin-based thermoplastic elastomer can be used. It is necessary to lower the hardness of the plastic elastomer. Therefore, the ethylene / α-olefin copolymer which is the component (A) of the present invention has a copolymerization ratio of the α-olefin of 20 to 20.
It needs to be 60% by weight. Preferably 25 to
50% by weight. α-olefin copolymerization ratio is 60
If the amount is more than 10% by weight, the strength of the polyolefin-based thermoplastic elastomer of the present invention is greatly reduced, which is not preferable. or,
If the content is less than 20% by weight, it is difficult to obtain a low hardness for a laminate obtained from the olefin elastomer of the present invention.

The density of the ethylene / α-olefin-based copolymer must be less than 0.880 g / cm ³ . Preferably it is less than 0.870 g / cm ³ . 0.
If it exceeds 880 g / cm ³ , it will be difficult to achieve a low hardness aimed at a laminate obtained from the polyolefin-based thermoplastic elastomer of the present invention. ethylene·
When the copolymerization ratio of α-olefin in the α-olefin copolymer and the density of the ethylene / α-olefin copolymer are within the above ranges, the hardness of the ethylene / α-olefin copolymer is generally The Shore A hardness is less than 75, and the Shore A hardness of the ethylene / α-olefin-based copolymer of the present invention is preferably less than 75. . When the Shore A hardness is more than 75, it is difficult to reduce the hardness so as to aim at a laminate obtained from the polyolefin-based thermoplastic elastomer of the present invention.

The ethylene (α) component (A) of the present invention
The longer the length of the branched side chain, the lower the mechanical strength of the olefin copolymer, the lower the copolymerized α.
-Even when the olefin ratio (% by weight) is the same, the density can be further reduced, and thus a polyolefin elastomer having low hardness and high strength can be obtained. Among them, the ethylene-octene-1 copolymer is most preferable because it can be easily crosslinked and has excellent mechanical strength.

The ethylene (α) component (A) of the present invention
The melt index of the olefin copolymer is 0.0
Those in the range of 1 to 100 g / 10 minutes (190 ° C., 2.16 kg) are preferably used, and more preferably 0.1 g / min.
2 to 20 g / 10 min. If it exceeds 100 g / 10 minutes, the rubber elasticity is insufficient, and if it is less than 0.01 / 10 minutes, the processability at the time of dynamic crosslinking is poor. It is necessary that the ethylene / α-olefin copolymer as the component (A) is partially or completely crosslinked. The polyolefin-based thermoplastic elastomer of the present invention shows that when the ethylene / α-olefin-based copolymer (A) is cross-linked and non-cross-linked, However, heat resistance, compression set and the like are extremely good. The ratio of the crosslinked ethylene / α-olefin copolymer (rubber-like polymer which does not dissolve in the solvent) in the total ethylene / α-olefin copolymer in the polyolefin-based thermoplastic elastomer of the present invention is determined by the degree of crosslinking. The degree of crosslinking is preferably 30% or more, more preferably 50% or more. If it is 30% or less, heat resistance and compression set are inferior.

Next, the polyolefin resin as the component (B) in the polyolefin thermoplastic elastomer of the present invention will be described. The polyolefin-based resin is roughly composed of a polyethylene-based resin, a polypropylene-based resin, or a mixture of a polyethylene-based resin and a polypropylene-based resin. As the polyethylene resin, high density polyethylene (HDPE), low density polyethylene (LDP)
E), linear low density polyethylene (LLDPE), copolymer of acrylic vinyl monomer and ethylene (EE
A, EMMA, etc.) or a copolymer of a vinyl acetate monomer and ethylene (EVA). However, among these, high density polyethylene (HD
PE), low-density polyethylene (LDPE) and linear low-density polyethylene (LLDPE) are particularly preferred because they are available at low cost. These polyethylene resins may be used alone or in combination of two or more.

When high density polyethylene (HDPE) is used as component (B) of the present invention, its density is generally in the range of 0.930 to 0.970 g / cm ² ,
The melt flow rate (MFR) measured at 190 ° C. under a load of 2.16 kg is preferably in the range of 0.05 to 100 g / 10 minutes. Low density polyethylene (LDP
E) Or linear low density polyethylene (LLDPE)
Is used, its density is generally from 0.900 to
0.930 g / cm ² , 190 ° C., 2.1
Melt flow rate (MFR) measured at 6 kg load
Is preferably in the range of 0.05 to 100 g / 10 minutes. When the melt flow rate exceeds 100 g / 10 minutes, the mechanical strength and heat resistance of the polyolefin-based thermoplastic elastomer of the present invention are insufficient, and 0.05 g
If it is shorter than / 10 minutes, the fluidity is poor when molding the polyolefin-based thermoplastic elastomer of the present invention, and the molding processability is undesirably reduced. As the polypropylene resin, homopolypropylene, propylene and ethylene,
Other α- such as butene-1, pentene-1, hexene-1
Examples thereof include copolymer resins with olefins (including blocks and random resins).

The polypropylene resin used as the component (B) of the present invention has a melt flow rate (MFR) of 0.1 to 100 measured at 230 ° C. under a load of 2.16 kg.
It is preferably in the range of g / 10 minutes. When the melt flow rate exceeds 100 g / 10 minutes, the mechanical strength and heat resistance of the polyolefin-based thermoplastic elastomer of the present invention are insufficient, and when it is less than 0.1 g / 10 minutes, the polyolefin-based thermoplastic elastomer of the present invention is used. When molding an elastomer, the fluidity is poor and the molding processability is undesirably reduced.

The polyolefin resin as the component (B) in the polyolefin thermoplastic elastomer of the present invention comprises:
As described above, it is made of a polyethylene resin and / or a polypropylene resin. For example, a laminate of the polyolefin thermoplastic elastomer and the polyolefin resin of the present invention is required to have heat resistance depending on the use. Polypropylene resins are more preferable because of their high heat resistance. However, homopolypropylene generally tends to be oxidatively decomposed and has a tendency to decrease in mechanical strength due to a decrease in molecular weight during long-term use. On the other hand, polyethylene generally has a tendency to crosslink without oxidative decomposition and to maintain or improve mechanical strength. Because of this,
When using a polypropylene resin, particularly in applications where durability is required, it may be preferable to use a homopolypropylene and a polyethylene resin in combination or a propylene and an ethylene random or block polymer. is there. The polyolefin-based resin as the component (B) in the polyolefin-based thermoplastic elastomer of the present invention may be of one type or of two or more types.

In the polyolefin thermoplastic elastomer of the present invention, the ratio of the ethylene / α-olefin copolymer (A) to the olefin resin (B) is such that the component (A) is 50 to 85% by weight. % Of the component (B) is preferably 15 to 50% by weight. Also,
Component (B) is 1 to 60-85% by weight of component (A).
More preferably, it is 5 to 40% by weight. Furthermore,
70% to 80% by weight of component (A) and 2% of component (B)
It is particularly preferred that the amount is 0 to 30% by weight. When the amount of the component (A) is less than 50% by weight, it becomes difficult to obtain a target low-hardness polyolefin-based thermoplastic elastomer. When the component (A) exceeds 85% by weight, the mechanical strength of the polyolefin-based thermoplastic elastomer itself is low.

Next, the rubber oil as the component (C) in the polyolefin-based thermoplastic elastomer of the present invention will be described. As the rubber oil, a paraffinic or naphthenic process oil is preferred. In the case of a dynamically crosslinked polyolefin-based thermoplastic elastomer comprising only an ethylene / α-olefin-based copolymer (A) and an olefin-based resin (B) without adding a rubber oil, the polyolefin Laminates with a system resin are most preferred because they exhibit good adhesion. Therefore, the present invention does not exclude a composition in which the rubber oil which is the component (C) is not added.
It is preferred to add components. The addition amount depends on the hardness of the ethylene / α-olefin-based copolymer used, but is preferably 5 to 40 parts by weight, more preferably 10 to 30 parts by weight, per 100 parts by weight of the ethylene / α-olefin copolymer.
Parts by weight. If the amount is less than 5 parts by weight, it is difficult to obtain a laminate having an A hardness of 75 or less with the currently available ethylene / α-olefin copolymer. If the amount exceeds 40 parts by weight, the adhesion between the polyolefin-based thermoplastic elastomer of the present invention and the polyolefin-based resin as the base material becomes low, which is not preferable in practical use. In any case, the rubber oil as the component (C) in the olefin-based thermoplastic elastomer of the present invention needs to be less than 40 parts by weight based on 100 parts by weight of the ethylene / α-olefin copolymer. .

The polyolefin-based thermoplastic elastomer of the present invention is used by laminating with a polyolefin-based resin. Its use is for automotive interior parts, tools and the like. The lower the hardness of the polyolefin-based thermoplastic elastomer of the present invention, which is laminated on the polyolefin-based resin, the better the feel when touched by a human hand or the less injuries and damage to the material even when the human is hit. Therefore, it is preferable that the hardness is low. The polyolefin-based thermoplastic elastomer of the present invention preferably has a Shore A hardness of less than 75. More preferably, it is less than 70.

Next, a method for producing the polyolefin-based thermoplastic elastomer of the present invention will be described. The polyolefin-based thermoplastic elastomer of the present invention comprises (A) an ethylene / α-olefin-based copolymer mainly comprising partially or completely crosslinked ethylene and an α-olefin having 3 to 20 carbon atoms, and (B) a polyolefin. And (C) a dynamically crosslinked polyolefin-based thermoplastic elastomer mainly composed of a rubber oil in an amount necessary for exhibiting excellent adhesion to a low-hardness polyolefin-based resin as a base material. A general method for producing the dynamically crosslinked polyolefin-based thermoplastic elastomer is as follows: an ethylene / α-olefin-based copolymer as the component (A), a polyolefin-based resin as the component (B), and a rubber as the component (C). The ethylene / α-olefin-based copolymer is partially or completely cross-linked by heat-treating an oil, a cross-linking agent, and a cross-linking auxiliary with a twin-screw extruder, a Banbury mixer, or the like to produce the product. In this case, the crosslinking agent preferably used includes a radical initiator such as an organic peroxide and an organic azo compound.

Specific examples of the radical initiator include:
1,1-bis (t-butylperoxy) -3,3,5-
Trimethylcyclohexane, 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-hexylperoxy) cyclohexane, 1,1-bis (t-butylperoxy) ) Cyclododecane, 1,1-bis (t-butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl-4,4-bis (t-butylperoxy) butane, Peroxy ketals such as n-butyl-4,4-bis (t-butylperoxy) valerate; di-t-butyl peroxide, dicumyl peroxide, t-butylcumyl peroxide, α, α′-bis (T-butylperoxy-m-isopropyl) benzene, α, α'-bis (t-butylperoxy) diisopropylbenzene, 2,5-di Methyl-2,5-bis (t
-Butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3
Dialkyl peroxides such as acetyl peroxide, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, and 2,4- Diacyl peroxides such as dichlorobenzoyl peroxide and m-trioyl peroxide; t-butylperoxyacetate, t-butylperoxyisobutyrate, t-butylperoxy-2-ethylhexanoate, t-butyl Peroxylaurate, t-butylperoxybenzoate, di-t-butylperoxyisophthalate, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, t-butylperoxymaleic acid, t-butylperoxymaleate Peroxyesters such as tilperoxyisopropyl carbonate and cumylperoxyoctate; and t-butyl hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethylhexane-2,5- Examples thereof include hydroperoxides such as dihydroperoxide and 1,1,3,3-tetramethylbutyl peroxide.

Among these compounds, 1,1-bis (t-butylperoxy) -3,3,5-trimethylcyclohexane, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl -2,5-bis (t-butylperoxy) hexane and 2,5-dimethyl-2,5-bis (t-butylperoxy) hexyne-3 are preferred. These radical initiators include ethylene / α-olefin copolymer and polyolefin resin 1
0.02 to 3 parts by weight, preferably 0.1 to 100 parts by weight.
It is used in an amount of from 0.5 to 1 part by weight. The level of crosslinking is mainly determined by this amount. If the amount is less than 0.02 parts by weight, the crosslinking is insufficient, and if the amount exceeds 3 parts by weight, the crosslinking rate is not greatly improved, so that it is not a preferable direction.

Examples of the crosslinking assistant include divinylbenzene, triallyl isocyanurate, triallyl cyanurate,
Diacetone diacrylamide, polyethylene glycol diacrylate, polyethylene glycol dimethacrylate, trimethylolpropane trimethacrylate,
Trimethylolpropane triacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, diisopropenylbenzene, P-quinone dioxime, P, P'-dibenzoylquinone dioxime, phenylmaleimide, allyl methacrylate, N , N'-m-
Phenylene bismaleimide, diallyl phthalate, tetraallyloxyethane, 1,2-polybutadiene and the like are preferably used. These crosslinking aids may be used in combination of two or more.

The crosslinking aid is used in an amount of 0.1 to 5 parts by weight, preferably 0.5 to 2 parts by weight, based on 100 parts by weight of the ethylene / α-olefin copolymer and the polyolefin resin. If the amount is less than 0.1 part by weight, the degree of crosslinking is unpreferably low. If the amount exceeds 5 parts by weight, the degree of crosslinking is not greatly improved, which is not a preferable direction. It is preferable to use a crosslinking agent and a crosslinking auxiliary as described above as a method of crosslinking,
In addition, a phenol resin or bismaleimide can be used as a crosslinking agent.

The polyolefin-based thermoplastic elastomer of the present invention is basically a partially or completely crosslinked ethylene / α-olefin-based copolymer which is at least the component (A), and a polyolefin-based resin which is the component (B) And (C) a rubber oil, which may contain other components, if necessary, such as a resin other than the polyolefin-based resin, an inorganic filler, and a plasticizer. As resins other than polyolefin resins,
For example, polystyrene resins, polyamide resins, polyphenylene ether resins, polyurethane resins, polycarbonate resins, polyester resins, and the like can be given. When these resins other than the polyolefin-based resin are used in combination, the polyolefin-based resin and the above-mentioned resins other than the polyolefin-based resin generally do not mix with each other, and the molded product may be phase-separated. In this case, a compatibilizer is added to increase the affinity between the two.

Examples of the inorganic filler include magnesium hydroxide, aluminum hydroxide, talc, calcium carbonate, magnesium carbonate, silica, carbon black,
Glass fibers, carbon fibers, whiskers, titanium oxide, clay, mica, and the like are included. Among them, magnesium hydroxide and aluminum hydroxide are effective for imparting flame retardancy. Examples of the plasticizer include phthalic acid esters such as polyethylene glycol and dioctyl phthalate (DOP). Also, other additives such as organic / inorganic pigments, heat stabilizers, antioxidants, ultraviolet absorbers, light stabilizers, flame retardants, silicone oils, antiblocking agents, foaming agents, antistatic agents, antibacterial agents, etc. Are also preferably used.

The polyolefin-based thermoplastic elastomer of the present invention is used by laminating it on a polyolefin-based resin. As described above, the purpose of the invention is to use a hard resin such as an olefin-based resin such as a polypropylene-based resin alone to be touched by human hands. The feel is poor when hit or there is injury or damage to the material when hit by people. A soft polyolefin-based thermoplastic elastomer is laminated on a hard polyolefin-based resin in order to improve the feel when touched by a human hand or to prevent injuries and damage to the material even when the human is touched. The polyolefin resin, which is a base material on which the polyolefin thermoplastic elastomer is laminated, is roughly composed of a polyethylene resin, a polypropylene resin, or a mixture of a polyethylene resin and a polypropylene resin. Basically, the combination of the olefin resin as the base material and the olefin resin similar to the polyolefin resin as the component (B) of the polyolefin thermoplastic elastomer is preferable. The reason is,
Since the polyolefin-based thermoplastic elastomer uses the polyolefin-based resin as the component (B) as a matrix, the surface layer of the molded product of the polyolefin-based thermoplastic elastomer is mainly composed of the polyolefin-based resin as the component (B). When an adhesive or the like is not used, when the base material and the laminating resin are the same component, the interfacial adhesiveness is the highest and the olefin resin, which is the base material, is also the component (B) of the polyolefin thermoplastic elastomer for lamination. It is preferable that a certain polyolefin resin also has the same component. However, the components do not necessarily have to be the same, and good adhesion is exhibited even when both contain a common component. As an example of the combination of the polyolefin resin of the base material and the polyolefin resin as the component (B) in the polyolefin thermoplastic elastomer for lamination, for example, when the base material is polypropylene, ( The component B) is preferably the same polypropylene. When the substrate is polyethylene, the component (B) in the polyolefin-based thermoplastic elastomer is most preferably polyethylene. However, when the component (B) in the polyolefin-based thermoplastic elastomer is polyethylene, the polyethylene, which is a matrix, tends to crosslink during dynamic crosslinking, and depending on the conditions, the fluidity of the obtained dynamically crosslinked elastomer may be lost. There is also.
In this case, the polyolefin resin as the component (B)
Adhesion with a substrate is imparted by using a mixture of polypropylene and polyethylene.

Specific examples of the polyolefin resin as the base material include a polyethylene resin, a polypropylene resin, and a mixture of a polyethylene resin and a polypropylene resin. As the polyethylene resin, high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (L
LDPE), a copolymer of an acrylic vinyl monomer and ethylene (EEA, EMMA, etc.) or a copolymer of a vinyl acetate monomer and ethylene (EVA). Examples of the polypropylene resin include homopolypropylene, copolymer resins (including block and random) of propylene with other α-olefins such as ethylene, butene-1, pentene-1, and hexene-1. . The higher the rigidity of the polyolefin-based resin as the base material, the thinner the thickness can be measured as a whole, and the weight and cost can be reduced. As the base material in this case, polyolefin-based resin, glass fiber, fibrous filler such as carbon fiber, talc, needle filler such as magnesium oxysulfate whisker, powdered filler such as talc and the like may be used. Can also.

The polyolefin-based thermoplastic elastomer of the present invention can be laminated with a polyolefin-based resin by various molding methods. As a specific molding method,
For example, an insert molding method in which a polyolefin-based resin molded product as a base material is loaded into a mold and injection molding of a polyolefin-based thermoplastic elastomer is performed, and after the polyolefin-based resin as a base material is injection-molded, then a polyolefin-based thermoplastic elastomer is formed. Two-color molding method of injection molding, co-extrusion method of simultaneously extruding olefin-based resin and polyolefin-based thermoplastic elastomer as a base material into a sheet, compression-pressing of polyolefin-based resin and polyolefin-based thermoplastic elastomer as base materials Examples thereof include a press method in which each is formed into a sheet by extrusion or the like and both are compression-pressed, and a blow molding method in which a polyolefin-based resin and a polyolefin-based thermoplastic elastomer as base materials are simultaneously extruded and blow-molded.

[0032]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. In these examples and comparative examples, the test methods used for evaluating various physical properties are as follows.

1. Test Method (1) Surface Hardness (Shore A Hardness) Four 2 mm-thick sheets were stacked and evaluated according to ASTM D2240 using an A type in a 23 ° C. atmosphere. (2) Tensile breaking strength Measured at 23 ° C. by a method according to JIS K6251. (3) Tensile elongation at break Measured at 23 ° C. by a method according to JIS K6251. (4) Compression set (C-Set) 100 ° C. × 22 by a method based on JIS K6301.
The time was evaluated. (5) Adhesive strength It was evaluated by a method based on JIS K6854. 180
This is the strength at the time of peeling. (6) Degree of Crosslinking 0.5 g of the crosslinked thermoplastic elastomer was added to xylene 200
Reflux in ml for 4 hours. The solution was filtered with a filter paper for quantification, the residue on the filter paper was vacuum-dried, quantified, and calculated as the ratio (%) of the weight of the residue to the weight of the rubbery polymer in the crosslinked thermoplastic elastomer.

2. Raw Materials (1) Ethylene / α-olefin copolymer (a) Ethylene / octene-1 copolymer The following four kinds of samples were produced by a method using a metallocene catalyst.

* Composition ratio: ethylene / octene-1 = 60/40 (weight ratio) Density: 0.857 g / cm ³ Shore A hardness: 51 (referred to as TPE-1) * Composition ratio: ethylene / octene-1 = 72/28 (weight ratio) Density: 0.863 g / cm ³ Shore A hardness: 66 (referred to as TPE-2) * Composition ratio: ethylene / octene-1 = 76/24 (weight ratio) Density: 0.870 g / cm ³ Shore A hardness: 75 (referred to as TPE-3) * Composition ratio: ethylene / octene-1 = 81/19 (weight ratio) Density: 0.886 g / cm ³ Shore A hardness: 81 (referred to as TPE-4) (B) Ethylene / propylene / ethylidene norbornene copolymer-1 Produced by a method using a metallocene catalyst. Composition ratio: ethylene / propylene / ethylidene norbornene = 50/45/5 Density: 0.87 g / cm ³ Shore A hardness: 73 (referred to as TPE-5) (c) Ethylene / propylene / ethylidene norbornene copolymer-2 Ziegler It was manufactured by a method using a system catalyst. Composition ratio: ethylene / propylene / ethylidene norbornene = 47.5 / 43 / 9.5 Density: 0.86 g / cm ³ Shore A hardness: 67 (referred to as TPE-6)

(2) Polyolefin resin (a) Polypropylene Isotactic homopolypropylene (trade name MA03) (referred to as PP) manufactured by Nippon Polychem Co., Ltd. (b) Ethylene (E) -propylene (PP) copolymer resin Nippon Polyolefin Co., Ltd., random E-PP resin [E / PP = 7/93 (weight ratio)] (trade name: PM94)
0M) (referred to as EP) (c) High density polyethylene Suntech HD (trade name: B47, manufactured by Asahi Kasei Corporation)
0) (referred to as HDPE) (4) Radical initiator 2,5-dimethyl-2,5-bis (t-manufactured by NOF Corporation)
Butylperoxy) hexane (trade name Perhexa 25)
B) (referred to as POX) (5) Crosslinking aid Wako Pure Chemical, divinylbenzene (referred to as DVB) (6) Rubber oil (paraffin oil) Idemitsu Kosan, Diana Process Oil (trade name PW-3)
80) (referred to as PO)

[0037]

Examples 1 to 8 and Comparative Examples 1 to 3 As an extruder, a twin screw extruder (40 mmφ, L /
D = 47) was used. As the screw, a double screw having a kneading portion before and after the injection port was used. An ethylene / α-olefin-based copolymer, a polyolefin-based resin, a cross-linking agent and a cross-linking aid were mixed at the ratio shown in Table 1, and the mixture was melt-extruded at a cylinder temperature of 220 ° C. At the time of this melt extrusion, the oil for rubber shown in Table 1 was injected from the injection port at the center to obtain a dynamically crosslinked polyolefin-based thermoplastic elastomer. Using an injection molding machine (Toshiba IS45PNV), a separately molded polypropylene (PP) flat plate
The resulting mixture was charged into a mold set at a temperature of 200 ° C., and the dynamically crosslinked polyolefin-based thermoplastic elastomer was insert-molded at 220 ° C. The results are summarized in Table 1.

[0038]

[Table 1]

[0039]

The polyolefin-based thermoplastic elastomer of the present invention is used by being laminated on a polyolefin-based resin.
The polyolefin-based thermoplastic elastomer of the present invention has low hardness and high strength, and is excellent in compression set, heat resistance and the like. Laminated products composed of polyolefin-based resin and polyolefin-based thermoplastic elastomer are used as the base material by crushing the same component as the main raw material and adding a reinforcing material for the reduced strength. It also has features that can be used. This laminated product can be widely used for applications such as interior parts for automobiles such as assist grips or shift lever knobs, tools such as drivers or power tool housings, building materials such as handrails, etc.
It plays a major role in industry.

Continued on front page F-term (reference) 4F100 AK03A AK03B AK05 AK07 AK62A AK64 AL09A BA02 BA07 BA15 GB07 GB32 JA13A JB12A JB15A JB16A JL12 YY00A 4J002 AE053 BB03X BB05W BB06X BB12X BB12X

Claims (4)

[Claims] 1. An ethylene / α-olefin-based copolymer comprising (A) a partially or completely crosslinked ethylene and an α-olefin having 3 to 20 carbon atoms, (B) a polyolefin-based resin and (C) ) Made of a dynamically crosslinked polyolefin-based thermoplastic elastomer mainly composed of rubber oil,
The ethylene / α-olefin copolymer has an α-olefin copolymerization ratio of 20 to 60% by weight and a density of 0.88%.
0 g / cm and less than ³ and a polyolefin resin laminating polyolefin heat, wherein the content of the rubber oil is less than 40 parts by weight relative to the ethylene · alpha-olefin copolymer 100 parts by weight Plastic elastomer. 2. The laminating polyolefin-based thermoplastic elastomer according to claim 1, wherein the ethylene / α-olefin-based copolymer as the component (A) is produced with a metallocene-based catalyst. 3. The polyolefin thermoplastic elastomer for lamination according to claim 1, wherein the polyolefin resin as the component (B) is mainly composed of a polypropylene resin. 4. A laminated product obtained by laminating the polyolefin-based thermoplastic elastomer according to claim 1 on a polyolefin-based resin.