CN1946788A - Thermoplastic elastomer composition, formed article and sealing material having low hardness - Google Patents

Abstract

A first thermoplastic elastomer composition which comprises 100 parts by mass of the sum of 5 to 60 mass % of [A] an ethylene.alpha-olefin based copolymer having a limiting viscosity of 3.5 dl/g or more as measured in a decalin solvent at 135 DEG C, 1 to 20 mass % of [B] a polyolefin based resin and 30 to 94 mass % of [C] a mineral oil based softening agent (provided that the sum of [A], [B] and [C] is 100 mass %), and 0.1 to 50 parts by mass of a hydrogenated diene based polymer, wherein at least the above [A] an ethylene.alpha-olefin based copolymer and [B] a polyolefin based resin have been subjected to a dynamic heat treatment in the presence of a cross-linking agent; or a second thermoplastic elastomer composition obtained by substituting [A] component of the first thermoplastic elastomer composition with an oil-extended rubber consisting of 20 to 80 mass % of [A1] an ethylene.alpha-olefin based copolymer having a limiting viscosity of 3.5 dl/g or more as measured in a decalin solvent at 135 DEG C and 20 to 80 mass % of [C1] a mineral oil based softening agent (provided that the sum of [A1] and [C1] is 100 mass %). The above thermoplastic elastomer composition is excellent in processability, has a low hardness, is free from the bleeding of a softening agent such as a mineral oil, has softness, is excellent in rubbery elastic properties (rebound, compression set) and further can be recycled.

Description

Thermoplastic elastomer composition, molded article and low hardness sealing material

technical field

The present invention relates to a thermoplastic elastomer composition, a molded article using the composition, and a low-hardness sealing material. A thermoplastic elastomer composition and a molded article excellent in permanent deformation) and free from exudation of a mineral oil-based softener, and further relates to a low-hardness sealing material made of a thermoplastic elastomer composition.

Background technique

Sealants used in sealing materials for office machines, automobiles, building materials, etc. are very flexible, and attempts have been made to improve vulcanized rubber or vulcanized foamed rubber, foamed urethane, or thermoplastic elastomer compositions that can be used as flexible materials (Refer to Patent Documents 1-3). A thermoplastic elastomer composition is disclosed in Patent Document 1, etc., but the composition of this document has insufficient flexibility, and if a softener such as mineral oil is added, the softener will ooze out of the molded product, resulting in rubber elasticity. issues such as reduction.

Vulcanized rubber, vulcanized foamed rubber, and foamed polyurethane satisfy requirements in terms of properties such as flexibility and airtightness, but in recent years, they cannot satisfy the high recyclability required from the viewpoint of resources.

Patent Document 1: Japanese Patent Laid-Open No. 2002-201313

Patent Document 2: Japanese Patent Laid-Open No. 2002-251061

Patent Document 3: Japanese Patent Application Laid-Open No. 7-234579

Contents of the invention

The object of the present invention is to provide a thermoplastic elastomer composition having excellent moldability, low hardness, no leakage of softeners such as mineral oil, flexibility, and excellent rubber elasticity (resilience, compression set) and its molded article and low hardness sealing materials.

The present invention provides thermoplastic elastomer compositions shown below, molded articles thereof, and low-hardness sealing materials.

(1) A thermoplastic elastomer composition containing 0.1 to 50 parts by mass of [D] a hydrogenated diene-based polymer per 100 parts by mass of the total of [A], [B], and [C], wherein the [A] is 5-60% by mass of an ethylene-α-olefin copolymer having an intrinsic viscosity of 3.5 dl/g or more as measured in a decalin solvent at 135°C, and [B] is 1-20% by mass of a polymer. Olefin-based resin, and [C] is 30-94% by mass mineral oil-based softener (the sum of [A], [B] and [C] is 100% by mass);

At least the [A] ethylene·α-olefin-based copolymer and the [B] polyolefin-based resin are dynamically heat-treated in the presence of a crosslinking agent.

(2) A thermoplastic elastomer composition containing 0.1 to 50 parts by mass of a hydrogenated diene polymer of [D1] relative to 100 parts by mass of the total of [X], [B1], and [C2], wherein the [X] is 5-60% by mass of oil-extended rubber containing [A1] 20-80% by mass of ethylene having an intrinsic viscosity of 3.5 dl/g or more measured at 135°C in a decalin solvent. α-olefin-based copolymer, and [C1] 20-80% by mass of mineral oil-based softener (the total of [A1] and [C1] is 100% by mass); [B1] is 1-20% by mass of polyolefin-based resin ; and [C2] is 30-94% by mass mineral oil-based softener (the sum of [X], [B1] and [C2] is 100% by mass);

At least the above-mentioned [A1] ethylene·α-olefin-based copolymer and the above-mentioned [B1] polyolefin-based resin are dynamically heat-treated in the presence of a crosslinking agent.

(3) The thermoplastic elastomer composition of the above (1) or (2), wherein the hydrogenated diene polymer [D] is at least one selected from the group consisting of a monomer composed of a conjugated diene compound A hydrogenated product of a polymer of a unit, a hydrogenated product of a polymer containing a monomer unit formed of a conjugated diene compound and a monomer unit formed of a vinyl aromatic compound.

(4) The thermoplastic elastomer composition according to any one of (1) to (3) above, which has a Shore E (Duro E) hardness of 80 or less as measured in accordance with JIS K6253.

(5) The thermoplastic elastomer composition according to any one of (1) to (4) above, wherein the total of all monomer units including ethylene monomer units and monomer units formed from α-olefin compounds is When 100 mol%, the content of the ethylene monomer unit which comprises the said ethylene·α-olefin copolymer [A] and [A1] is 35-95 mol%.

(6) The thermoplastic elastomer composition according to any one of (1) to (5) above, wherein the mineral oil-based softeners [C], [C1] and [C2] are paraffin-based mineral oils.

(7) The thermoplastic elastomer composition according to any one of the above (1)-(6), wherein the above-mentioned crosslinking agent is selected from 1,3-bis(tert-butylperoxyisopropyl)benzene, 2, 5-Dimethyl-2,5-bis(tert-butylperoxy)hexyne-3,2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, α,α- Organic peroxides of bis(tert-butylperoxy)diisopropylbenzene, dicumyl peroxide and 2-tert-butyl peroxide.

(8) The thermoplastic elastomer composition according to any one of (1) to (7) above, wherein the cyclohexane-insoluble fraction of the ethylene·α-olefin copolymer in the thermoplastic elastomer composition at 23°C is 60% by mass or more.

(9) A molded article containing the thermoplastic elastomer composition according to any one of (1) to (8) above.

(10) A low-hardness sealing material made using the thermoplastic elastomer composition described in any one of (1)-(8) above.

(11) The low-hardness sealing material of the above (10), which has a Shore A hardness of 40 or less as measured in accordance with JIS K6253.

(12) The low-hardness sealing material in (10) or (11) above, which is formed in any one shape selected from an O-ring shape, a sheet shape, and a rod shape.

(13) A container comprising the low-hardness sealing material according to any one of (10) to (12) above as a constituent member.

(14) A container formed by molding a composite body consisting of a sealing part and a box part by injection molding, wherein the sealing part contains the low-hardness seal of any one of the above (10)-(12) Material.

(15) The container according to (14) above, wherein the box part contains a thermoplastic resin and/or a thermoplastic elastomer composition and is recyclable.

(16) A toner cartridge comprising the low-hardness sealing material according to any one of (10) to (12) above as a constituent member.

The thermoplastic elastomer composition of the present invention contains 0.1 to 50 parts by mass of [D] a hydrogenated diene polymer based on 100 parts by mass of the total of the following [A], [B] and [C], said [A] 5-60% by mass of an ethylene-α-olefin copolymer having an intrinsic viscosity of 3.5 dl/g or more as measured in a decalin solvent at 135°C, [B] being 1-20% by mass of a polyolefin-based resin, [C] is 30-94% by mass mineral oil-based softener (total of [A], [B], and [C] is 100% by mass); at least the above-mentioned [A] ethylene·α-olefin copolymer and the above-mentioned [ B] Polyolefin-based resins are dynamically heat-treated in the presence of a cross-linking agent; thus, injection molding, extrusion molding, hollow molding, compression molding, vacuum molding, lamination molding, calendering molding, etc. are excellent in molding processability and low in hardness , Mineral oil-based softener does not bleed out, has softness, and has excellent rubber elasticity (rebound elasticity, compression set).

Another thermoplastic elastomer composition of the present invention contains 0.1 to 50 parts by mass of [D1] a hydrogenated diene-based polymer relative to 100 parts by mass of the total of the following [X], [B1], and [C2], wherein [X] is 5-60% by mass of an oil-extended rubber containing [A1] 20-80% by mass of ethylene·α having an intrinsic viscosity of 3.5 dl/g or more measured in a decalin solvent at 135°C - Olefin-based copolymer, [C1] 20-80% by mass of mineral oil-based softener (total of [A1] and [C1] is 100% by mass); [B1] is 1-20% by mass of polyolefin-based resin; [ C2] is 30-94% by mass mineral oil-based softener (total of [X], [B1] and [C2] is 100% by mass); at least the above-mentioned [A1] ethylene·α-olefin copolymer and the above-mentioned [B1 ] Polyolefin-based resins are dynamically heat-treated in the presence of a cross-linking agent, so that injection molding, extrusion molding, hollow molding, compression molding, vacuum molding, lamination molding, calender molding, etc. are excellent in molding processability and low in hardness , Mineral oil-based softener does not bleed out, has softness, and has excellent rubber elasticity (rebound elasticity, compression set).

When the above-mentioned hydrogenated diene polymer [D] is at least one selected from the following, its Shore E hardness specified by JIS K6253 can reach 80 or less, and a soft composition can be obtained: A hydrogenated product of a polymer of monomer units, and a hydrogenated product of a polymer containing a monomer unit formed of a conjugated diene compound and a monomer unit formed of a vinyl aromatic compound.

In this thermoplastic elastomer composition, when the cyclohexane-insoluble content of the ethylene/α-olefin copolymer at 23° C. is 60% by mass or more, rubber elasticity and mechanical strength are excellent.

The molded article of the present invention has low hardness, no leakage of the mineral oil-based softener, flexibility, and excellent rubber elasticity (resilience, compression set). Furthermore, since the sealing material of the present invention is composed of a thermoplastic elastomer composition, it is recyclable and extremely excellent in saving resources.

Using this low-hardness sealing material as a component can provide a container that can integrally mold the sealing portion and the box portion including the sealing material in a short time by injection molding, save labor in workability, and have excellent recyclability.

Brief description of the drawings

Fig. 1 is a photograph showing a container with a sealing portion comprising the low-hardness sealing material of the present invention as a constituent member.

FIG. 2 is a photograph showing a state in which the container with a sealing portion of FIG. 1 is separated into a sealing portion and a box body.

Fig. 3 is an explanatory diagram showing a water leakage and drop test.

Symbol Description

1...Sealing part, 2...Box body, 10...Container, 11...Cover, 12...Double tail clip, 13...Corrugated paper, 14...Sealing element, 15...Water

The best way to practice the invention

The present invention will be described in detail below.

The thermoplastic elastomer composition according to the first aspect of the present invention contains 0.1 to 50 parts by mass of [D] a hydrogenated diene polymer per 100 parts by mass of the total of [A], [B], and [C], wherein the [A] is 5-60% by mass of an ethylene-α-olefin-based copolymer having an intrinsic viscosity of 3.5 dl/g or more measured in a decalin solvent at 135°C, and [B] is 1-20% by mass of a polyolefin resin, [C] is 30-94% by mass mineral oil-based softener (total of [A], [B] and [C] is 100% by mass); at least the above-mentioned [A] ethylene·α-olefin copolymer It is obtained by performing dynamic heat treatment with the above-mentioned [B] polyolefin resin in the presence of a crosslinking agent.

The thermoplastic elastomer composition according to the second aspect of the present invention contains 0.1 to 50 parts by mass of [D1] a hydrogenated diene polymer per 100 parts by mass of the total of [X], [B1], and [C2], wherein the [X] is 5-60% by mass of oil-extended rubber containing 20-80% by mass of [A1] ethylene·α having an intrinsic viscosity of 3.5 dl/g or more as measured in a decalin solvent at 135°C - Olefin-based copolymer and 20-80% by mass of [C1] mineral oil-based softener (total of [A1] and [C1] is 100% by mass); [B1] is 1-20% by mass of polyolefin-based resin; [ C2] is 30-94% by mass mineral oil-based softener (total of [X], [B1] and [C2] is 100% by mass); at least the above-mentioned [A1] ethylene·α-olefin copolymer and the above-mentioned [B1 ] Polyolefin resin is dynamically heat-treated in the presence of a cross-linking agent.

Each component will be described in more detail below.

1. Ethylene·α-olefin-based copolymers ([A] and [A1])

The ethylene·α-olefin copolymer (hereinafter referred to simply as "EAO-based copolymer") is a unit composed of ethylene monomer units (a1) and α-olefins having 3 or more carbon atoms other than ethylene. Copolymers of monomeric units (a2).

The ethylene monomer unit (a1) constitutes preferably 35-95 mol%, more preferably 40-90 mol%, particularly preferably 45-85 mol%, based on 100 mol% of the total monomer units constituting the EAO copolymer. When the constituent amount of the ethylene monomer unit (a1) is too large, the flexibility of the thermoplastic elastomer composition obtained tends to be insufficient, and if it is too small, the mechanical strength may be insufficient.

The α-olefin forming the above-mentioned monomer unit (a2) preferably has 3 or more carbon atoms, including: propylene, 1-butene, 2-butene, isobutene, 1-pentene, 2-methyl-1-butene ene, 2-methyl-2-butene, 3-methylbutene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-heptene, 1 -octene, 1-decene, 1-undecene, etc. They may be used alone or in combination of two or more. Among them, an α-olefin having 3 to 10 carbon atoms is more preferable. By using the above-mentioned α-olefin, when the above-mentioned EAO copolymer contains other monomer units, it can be easily copolymerized with other monomer units. Particularly preferred α-olefins are propylene, 1-butene, 1-hexene and 1-octene, more preferably propylene and 1-butene.

When the total amount of monomer units constituting the EAO copolymer is 100 mol%, the content of the above-mentioned monomer unit (a2) is preferably 5-65 mol%, more preferably 10-45 mol%, particularly preferably 15-40 mol%. If the constituent amount of the monomer unit (a2) is too small, the obtained thermoplastic elastomer composition may not exhibit desired rubber elasticity. On the other hand, if it is too large, the durability of the obtained composition may decrease.

The above-mentioned EAO copolymer may be a binary copolymer composed of the above-mentioned monomer units (a1) and (a2), or may be composed of these monomer units (a1) and (a2), and other monomer units (a3) polymers (terpolymers, tetrapolymers, etc.). Examples of such other monomer units include monomer units of non-conjugated diene compounds and the like.

Non-conjugated diene compounds include linear acyclic diene compounds such as 1,4-hexadiene, 1,5-hexadiene, and 1,6-hexadiene, 5-methyl-1,4 -Hexadiene, 3,7-Dimethyl-1,6-octadiene, 5,7-Dimethylocta-1,6-diene, 3,7-Dimethyl-1,7-octadiene Diene, 7-methylocta-1,6-diene, dihydromyrcene and other branched acyclic diene compounds, tetrahydroindene, methyltetrahydroindene, dicyclopentadiene, bicyclo[2.2. 1]-hepta-2,5-diene, 5-methylene-2-norbornene, 5-ethylidene-2-norbornene, 5-propenyl-2-norbornene, 5-iso Alicyclic diene compounds such as propylene-2-norbornene, 5-cyclohexylene-2-norbornene, 5-vinyl-2-norbornene, and the like. They may be used alone or in combination of two or more. Among them, 1,4-hexadiene, dicyclopentadiene, 5-ethylidene-2-norbornene, and the like are preferable.

When using the EAO copolymer containing the above-mentioned monomer unit (a3), the total amount of monomer units constituting the EAO copolymer is 100 mol%, and the constituent amount of the above-mentioned monomer unit (a3) is preferably 10 mol% or less, more preferably 1-8mol%. When the constituent amount of the above-mentioned monomer unit (a3) is too large, the durability of the obtained composition may decrease.

The above-mentioned EAO-based copolymer has an intrinsic viscosity (measured in a decalin solvent at 135°C) of 3.5 dl/g or more, preferably 3.8 dl/g or more, more preferably 4.0-7.0 dl/g. If the intrinsic viscosity is less than 3.5 dl/g, the mineral oil-based softener may bleed out from the obtained thermoplastic elastomer composition, which may lower the rubber elasticity.

As the above-mentioned EAO-based copolymer, a halogenated copolymer in which a part of hydrogen atoms in the molecule is substituted with halogen atoms such as chlorine atoms and bromine atoms can be used.

In the presence of these copolymers, vinyl chloride, vinyl acetate, (meth)acrylic acid, derivatives of (meth)acrylic acid [methyl (meth)acrylate, glycidyl (meth)acrylate , (meth)acrylamide, etc.], maleic acid, derivatives of maleic acid (maleic anhydride, maleimide, dimethyl maleate, etc.), conjugated diene compounds (butadiene, A graft polymer obtained by polymerizing unsaturated monomers such as isoprene, chloroprene, etc.).

The above-mentioned EAO-based copolymers may be used alone or in combination of two or more.

The EAO-based copolymer [A], polyolefin-based resin [B], and mineral oil-based softener [C] contained in the thermoplastic elastomer composition of the first aspect of the present invention are taken as 100% by mass. The content of the copolymer [A] is 5-60% by mass, preferably 10-58% by mass, more preferably 15-55% by mass. If the content of the EAO-based copolymer [A] is too large, the resulting thermoplastic elastomer composition may have insufficient flexibility, and if it is too small, the mineral oil-based softener [C] may ooze out.

As the ethylene/α-olefin copolymer [A1] constituting the oil-extended rubber [X] used to prepare the thermoplastic elastomer composition according to the second aspect of the present invention, the above-described copolymer can be used as it is. Assuming that the total of the EAO-based copolymer [A1] and the mineral oil-based softener [C1] constituting the oil-extended rubber [X] is 100% by mass, their ratios are 20-80% by mass and 20-80% by mass, respectively. , preferably 25-75% by mass and 25-75% by mass, more preferably 30-70% by mass and 30-70% by mass.

This The content of the oil-extended rubber [X] is 5-60% by mass, preferably 10-58% by mass, more preferably 15-55% by mass. If the content of the oil-extended rubber [X] is too large, the resulting thermoplastic elastomer composition may have insufficient flexibility, and if it is too small, the mineral oil-based softener [C1] and/or [C2] may ooze out.

The above-mentioned EAO-based copolymer ([A] or [A1]), for example, can be obtained by mixing ethylene, α-olefin and non- Conjugated diene, and a method of polymerizing by supplying hydrogen as a molecular weight modifier as needed are obtained by a medium-low pressure method of polymerization. This polymerization can be carried out by a gas phase method (fluidized bed or stirred bed), a liquid phase method (slurry method or solution method).

As the above-mentioned soluble vanadium compound, for example, the reaction product of at least one of VOCl ₃ and VCl ₄ with alcohol is preferably used. Methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n-hexanol, n-octanol, 2-ethylhexanol, n-decyl alcohol and n-dodecyl alcohol can be used as alcohol , wherein alcohols having 3-8 carbon atoms are preferably used.

The above organic aluminum compounds are, for example: triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, diethylaluminum monochloride, diisobutylaluminum monochloride, ethyl sesquichloride, butyl Aluminum sesquichloride, ethylaluminum dichloride, butylaluminum dichloride, methylaluminoxane, the reaction product of trimethylaluminum and water, etc. Wherein it is particularly preferred to use ethyl aluminum sesquichloride, butyl aluminum sesquichloride, a mixture of ethyl aluminum sesquichloride and triisobutyl aluminum, triisobutyl aluminum and butyl aluminum sesquichloride mixture. Hydrocarbons are preferably used as the above-mentioned solvents, and n-pentane, n-hexane, n-heptane, n-octane, isooctane, and cyclohexane are particularly preferably used. They may be used alone or in combination of two or more.

The non-oil-extended ethylene·α-olefin copolymer [A] and the oil-extended ethylene·α-olefin copolymer as oil-extended rubber [X] can be in the form of sacks, chips, granules, powders (including large Packaged crushed product) in any form. It is also possible to use the non-oil-extended ethylene·α-olefin copolymer [A] and the oil-extended ethylene·α-olefin copolymer [X] in combination.

2. Polyolefin-based resins ([B] and [B1])

The above-mentioned polyolefin-based resin may be a homopolymer or a copolymer as long as the monomer units containing one or more α-olefins total more than 50 mol%. In the case of a copolymer, it may be a copolymer of α-olefins, or a copolymer of α-olefins and other monomers copolymerizable with the α-olefins. In addition, as the polyolefin-based resin, a crystalline resin and/or an amorphous resin can be used.

For the above-mentioned polyolefin-based resin, when a crystalline polyolefin-based resin (Ba) is used, regarding its crystallinity, the degree of crystallinity measured by X-ray diffraction is 50% or more, preferably 53% or more, more preferably 55% or more above. The crystallinity is closely related to the density. For example, in case of polypropylene, the density of α-type crystal (monoclinic crystal) is 0.936 g/cm ³ , and the density of smectic crystal (quasi-hexagonal crystal) is 0.886 g/cm ³ , the density of the amorphous (atactic) component is 0.850 g/cm ³ . In the case of poly-1-butene, the density of the isotactic crystal component is 0.91 g/cm ³ , and the density of the amorphous (atactic) component is 0.87 g/cm ³ .

Therefore, the density of the above-mentioned crystalline polyolefin resin (Ba) is preferably 0.89 g/cm ³ or more, more preferably 0.90 to 0.94 g/cm ³ , and within this range, the degree of crystallinity can be made 50% or more, If the crystallinity of the crystalline polyolefin resin (Ba) is less than 50% and the density is less than 0.89 g/cm ³ , the heat resistance, strength, etc. of the resulting thermoplastic elastomer composition tend to decrease.

Preferred α-olefins forming the above-mentioned crystalline polyolefin-based resin (B-a) are α-olefins having 2 or more carbon atoms, more preferably 2-12 carbon atoms. Among them, propylene and 1-butene are preferable.

When the total amount of the monomer units constituting the crystalline polyolefin resin (B-a) is 100 mol%, the content of the α-olefin monomer units (b1) constituting the crystalline polyolefin resin (B-a) is preferably 80 mol% or more, more preferably 90-100 mol%.

When the above-mentioned crystalline polyolefin-based resin (B-a) is a copolymer, the copolymer may be either a block copolymer or a random copolymer. In order to produce a block copolymer with the above-mentioned crystallinity, the total amount of constituent units other than the α-olefin monomer unit (b1) is preferably 40 mol if the total amount of monomer units constituting the block copolymer is 100 mol%. % or less, more preferably 20 mol% or less. The above-mentioned block copolymers can be obtained by living polymerization using a Ziegler-Natta catalyst.

In order to produce a random copolymer with the above-mentioned crystallinity, the total amount of constituent units other than the monomer unit (b1) of α-olefin is preferably 15 mol% or less, more preferably 10 mol% or less.

The aforementioned random copolymer can be obtained, for example, by polymerizing an α-olefin or the like in the presence of a catalyst component containing a Ziegler-Natta catalyst, a soluble vanadium compound, an organoaluminum compound, and a solvent. The polymerization method includes medium and low pressure methods, etc., and can be carried out by gas phase method (fluidized bed or stirred bed), liquid phase method (slurry method or solution method) and the like. During polymerization, a molecular weight modifier such as hydrogen gas may be used as needed.

The above-mentioned soluble vanadium compound is preferably the reaction product of VOCl ₃ and/or VCl ₄ and alcohol. Alcohols include: methanol, ethanol, n-propanol, isopropanol, n-butanol, sec-butanol, tert-butanol, n-hexanol, n-octanol, 2-ethylhexanol, n-decyl alcohol and n-dodecyl alcohol, etc. , wherein alcohols with 3-8 carbon atoms are preferred.

The above organic aluminum compounds are, for example: triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, diethylaluminum monochloride, diisobutylaluminum monochloride, ethyl sesquichloride, butyl Aluminum sesquichloride, ethylaluminum dichloride, butylaluminum dichloride, methylaluminoxane, the reaction product of trimethylaluminum and water, etc. Among them, ethyl aluminum sesquichloride, butyl aluminum sesquichloride, a mixture of ethyl aluminum sesquichloride and triisobutyl aluminum, a mixture of triisobutyl aluminum and butyl aluminum sesquichloride are preferred .

The aforementioned solvent is preferably a hydrocarbon, particularly preferably n-pentane, n-hexane, n-heptane, n-octane, isooctane, and cyclohexane. They may be used alone or in combination of two or more.

The melting point of the above-mentioned crystalline polyolefin-based resin (B-a), that is, the maximum peak temperature measured by differential scanning calorimetry is preferably 100°C or higher, more preferably 120°C or higher. If the melting point is lower than 100°C, it tends to be difficult to exhibit sufficient heat resistance and strength.

The melt flow rate (temperature 230°C, load 2.16 kg) (hereinafter abbreviated as "MFR") of the above-mentioned crystalline polyolefin resin (B-a) is preferably 0.1-1,000 g/10 minutes, more preferably 0.5-500 g/10 minutes , more preferably 1-100 g/10 minutes. If the MFR is less than 0.1 g/10 minutes, the kneading processability, extrusion processability, etc. of the raw material composition will be insufficient. On the other hand, if it exceeds 1000 g/10 minutes, the strength of the obtained thermoplastic elastomer composition tends to decrease.

Therefore, the above-mentioned crystalline polyolefin resin (Ba) preferably has a crystallinity of 50% or more, a density of 0.89 g/ ^cm3 or more, a content of ethylene monomer units of 20 mol% or less, and a melting point of 100°C or more, And the MFR is 0.1-100 g/10 minutes, and it is particularly preferable to use polypropylene and/or a copolymer of propylene and ethylene with a melting point of 140-170°C.

The aforementioned crystalline polyolefin-based resins (B-a) may be used alone or in combination of two or more.

When an amorphous polyolefin-based resin (Bb) (hereinafter referred to as "amorphous polyolefin-based resin (Bb)") is used as the above-mentioned polyolefin-based resin, its crystallinity is measured by X-ray diffraction and has a degree of crystallinity of less than 50. %, preferably 30% or less, more preferably 20% or less. In terms of density, the above-mentioned amorphous polyolefin-based resin (B2) has a density of preferably 0.85-0.89 g/cm ³ , more preferably 0.85-0.88 g/cm ³ .

Preferred α-olefins forming the above-mentioned amorphous polyolefin-based resin (B-b) have 3 or more carbon atoms, more preferably 3-12.

Taking the total amount of the monomer units constituting the above-mentioned amorphous polyolefin resin (B-b) as 100 mol%, the content of the α-olefin monomer unit (b2) constituting the amorphous polyolefin resin (B-b) is preferably 60mol% or more.

The above-mentioned amorphous polyolefin resins (B-b) include: homopolymers such as atactic polypropylene and atactic poly-1-butene, more than 50 mol% of propylene and other α-olefins (ethylene, 1-butene , 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc.), more than 50mol% of 1-butene and other α-olefins ( Copolymers of ethylene, propylene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, etc.) and the like.

Atactic polypropylene and atactic poly-1-butene can be obtained by polymerization using a zirconocene-methylaluminoxane catalyst.

The above-mentioned atactic polypropylene can be obtained as a by-product of the polypropylene exemplified in the above-mentioned crystalline polyolefin-based polymer (B-a).

When the aforementioned amorphous polyolefin-based resin (B-b) is a copolymer, the copolymer may be in any form of a block copolymer or a random copolymer. In the case of a block copolymer, the monomer units (b-2) of α-olefin constituting more than 50 mol% must be combined in an atactic structure. The block copolymers are obtainable by living polymerization using Ziegler-Natta catalysts. The random copolymer can be obtained by the same method as the above-mentioned crystalline polyolefin polymer (B-a).

When the above-mentioned amorphous polyolefin resin (B-b) is a copolymer of α-olefin and ethylene having 3 or more carbon atoms, if the total amount of monomer units constituting the amorphous polyolefin resin (B-b) is 100 mol %, then the content of the above-mentioned α-olefin monomer unit (b2) is preferably 60-100 mol%.

The above-mentioned amorphous polyolefin-based resin (B-b) includes atactic polypropylene, a copolymer containing more than 50 mol% of propylene monomer units and ethylene monomer units, particularly preferably a copolymer of propylene and 1-butene .

The above-mentioned amorphous polyolefin-based resin (B-b) has a polystyrene-equivalent number average molecular weight Mn measured by GPC of preferably 1,000-20,000, more preferably 1,500-15,000.

The aforementioned amorphous polyolefin-based resins (B-b) may be used alone or in combination of two or more.

The above-mentioned polyolefin-based resins may be used alone or in combination depending on the purpose, use, and the like.

The polymer contained in the thermoplastic elastomer composition of the first aspect of the present invention is based on the total of the EAO-based copolymer [A], polyolefin-based resin [B], and mineral oil-based softener [C] as 100% by mass. The content of the olefin-based resin [B] is 1-20% by mass, preferably 3-18% by mass, more preferably 5-15% by mass. When the content of the polyolefin-based resin [B] is too large, the thermoplastic elastomer composition obtained tends to have insufficient flexibility, and if it is too small, the kneading processability tends to decrease.

The polyolefin contained in the thermoplastic elastomer composition of the second aspect of the present invention when the total of oil-extended rubber [X], polyolefin-based resin [B1], and mineral oil-based softener [C2] is 100% by mass The content of the system resin [B1] is 1-20% by mass, preferably 3-18% by mass, more preferably 5-15% by mass. If the content of the polyolefin-based resin [B1] is too large, the flexibility of the thermoplastic elastomer composition obtained tends to be insufficient, and if it is too small, the kneading processability tends to decrease.

3. Mineral oil-based softeners ([C], [C1], and [C2])

The mineral oil-based softener is not particularly limited as long as it is conventionally used for rubber products and the like, and there are paraffin-based, naphthenic-based, and aromatic-based mineral oils.

Softeners for rubber containing mineral oil-based hydrocarbons are generally a mixture of three of aromatic rings, naphthenic rings, and paraffin chains. Those whose paraffin chains account for 50% or more of the total carbon atoms are classified as paraffinic mineral oils, and those whose naphthenic rings account for 30-45% of the total carbon atoms are classified as naphthenes Aromatic-based mineral oils are classified as aromatic-based mineral oils in which the number of carbon atoms in the aromatic ring accounts for 30% or more of the total number of carbon atoms.

The above-mentioned paraffinic, naphthenic, and aromatic mineral oils may be used in combination, or they may be used alone or in combination of two or more. Among them, any one of [C], [C1], and [C2] is preferably paraffinic mineral oil, and hydrogenated paraffinic mineral oil is particularly preferable. Examples of paraffinic mineral oils include "Diana Process Oil PW90" and "Diana Process Oil PW380" manufactured by Idemitsu Kosan Co., Ltd.

The polystyrene-equivalent weight average molecular weight Mw of the mineral oil-based softener measured by GPC is preferably 300-2,000, more preferably 500-1,500. The kinematic viscosity at 40° C. is preferably 20-800 cSt, more preferably 50-600 cSt. The pour point is preferably -40 to 0°C, more preferably -30 to 0°C.

The aforementioned mineral oil-based softeners may be used in combination with low-molecular-weight hydrocarbons such as polybutene-based and polybutadiene-based softeners.

Assuming that the total amount of the EAO-based copolymer [A], polyolefin-based resin [B], and mineral oil-based softener [C] is 100% by mass, the thermoplastic elastomer composition of the first aspect of the present invention contains The content of the mineral oil-based softener [C] is 30-94% by mass, preferably 32-87% by mass, more preferably 35-80% by mass. If the content of the mineral oil-based softener [C] is too high, the strength of the obtained thermoplastic elastomer composition tends to be insufficient, and the mineral oil-based softener [C] may ooze out. If the amount is too small, the resulting plastic elastomer composition tends to have insufficient flexibility.

The mineral oil-based softener [C2] contained in the thermoplastic elastomer composition according to the second aspect of the present invention may be the same softener as the mineral oil-based softener [C1] constituting the oil-extended rubber [X], or may be Can be of different kinds. The content of the mineral oil-based softener [C2] is 30-94% by mass, preferably 32-87% by mass, more preferably 35-80% by mass. If the content of the above-mentioned mineral oil-based softener [C2] is too large, the strength of the obtained thermoplastic elastomer composition tends to be insufficient, and the mineral oil-based softener [C2] may bleed out. When the amount is too small, the resulting thermoplastic elastomer composition tends to have insufficient flexibility.

The thermoplastic elastomer composition of the second aspect of the present invention contains a smaller total amount of the mineral oil-based softener than the thermoplastic elastomer composition of the first aspect. This is because in the second aspect, the oil-extended rubber [X] already contains the mineral oil-based softener [C1].

4. Hydrogenated diene polymers ([D] and [D1])

The above-mentioned hydrogenated diene polymer is not particularly limited as long as it is a hydrogenated product of a diene polymer containing a monomer unit composed of a conjugated diene compound. Examples thereof include: (1) containing only (II) a hydrogenated product of a (co)polymer of a monomer unit formed from an alkene compound; Hydrogenated products such as polymers of monomer units formed from group compounds, etc.).

The above-mentioned hydrogenated diene polymer may be one kind in each case of the above-mentioned (I) and the above-mentioned (II), or two or more kinds thereof may be combined. A combination of the above (I) and the above (II) is also possible. The hydrogenated diene polymer may or may not be crosslinked in the thermoplastic elastomer composition of the present invention.

The above (I) includes hydrogenated butadiene block copolymers and the like.

The above-mentioned (II) includes: (i) block copolymers containing a polymer segment formed of a vinyl aromatic compound and a polymer segment formed of a conjugated diene compound (for example, hydrogenated styrene-butadiene block copolymer; block copolymers, hydrogenated styrene-isoprene block copolymers, hydrogenated styrene-butadiene-isoprene block copolymers, etc.); (ii) polymers containing vinyl aromatic compounds segment, a block copolymer of a random copolymer segment formed from a conjugated diene and a vinyl aromatic compound; (iii) a block copolymer containing a polymer segment formed from a conjugated diene compound, composed of a conjugated diene A block copolymer of a copolymer segment formed of a compound and a vinyl aromatic compound; (iv) containing a polymer segment formed of a conjugated diene compound, formed of a vinyl aromatic compound and a conjugated diene compound, and Block copolymers in which the monomer units formed by vinyl aromatic compounds are gradually increasing tapered segments; (v) containing random copolymer segments formed by conjugated diene compounds and vinyl aromatic compounds, A block copolymer formed from a vinyl aromatic compound and a conjugated diene compound and in which the monomer unit formed from the vinyl aromatic compound is a gradually increasing tapered segment, and the like.

Conjugated diene compounds are: 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1 , 3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene, etc. They may be used alone or in combination of two or more. Among them, 1,3-butadiene, isoprene, and 1,3-pentadiene are preferable.

Vinyl aromatic compounds are: styrene, tert-butylstyrene, α-methylstyrene, p-methylstyrene, p-ethylstyrene, divinylbenzene, 1,1-diphenylstyrene, Vinylnaphthalene, vinylanthracene, N,N-diethyl-p-aminoethylstyrene, vinylpyridine, etc. They may be used alone or in combination of two or more. Among them, styrene is preferable.

As the hydrogenated diene-based polymer, a halogenated hydrogenated diene-based polymer in which a part of hydrogen atoms in the molecule is substituted with a halogen atom such as a chlorine atom or a bromine atom can be used.

Vinyl chloride, vinyl acetate, (meth)acrylic acid, derivatives of (meth)acrylic acid [methyl (meth)acrylate, glycidyl (meth)acrylate, (meth)acrylamide, etc.], maleic acid, derivatives of maleic acid (maleic anhydride, maleimide, dimethyl maleate, etc.), conjugated diene compounds (butadiene, iso A graft polymer obtained by polymerizing unsaturated monomers such as pentadiene, chloroprene, etc.).

The hydrogenation rate of the above-mentioned hydrogenated diene-based polymer is preferably 70% or more, more preferably 90% or more, further preferably 95% or more. The "hydrogenation rate" refers to the number of ethylenically unsaturated bonds in the side chain or main chain of the conjugated diene unit constituting the diene polymer before hydrogenation, and the number of ethylenically unsaturated bonds in the side chain or main chain after hydrogenation. The ratio of the number of unsaturated bonds.

As the hydrogenated diene polymer, a non-crosslinked polymer or a crosslinked polymer may be used. They can also be used in combination. In addition, the crosslinked hydrogenated diene polymer can be obtained by a conventionally known method such as the method described below.

The above-mentioned hydrogenated diene polymer has a solution viscosity at 30°C of preferably 5 mPa·s or more, more preferably 10 mPa·s or more, when prepared as a 5% by mass toluene solution. This toluene solution viscosity is a proxy index of molecular weight, and if it is less than 5 mPa·s, the mechanical strength of the obtained thermoplastic elastomer composition tends to decrease.

The hydrogenated diene-based polymer is preferably a hydrogenated styrene-butadiene block copolymer or a hydrogenated styrene-butadiene-isoprene block copolymer.

The above-mentioned hydrogenated diene polymer can be easily prepared by a known method, for example, the method disclosed in Japanese Patent Laid-Open No. 2-36244, that is, a conjugated diene compound and a vinyl aromatic compound by living anion polymerization method, etc., a method of preparing a polymer before hydrogenation, and then hydrogenating the polymer before hydrogenation in the presence of a catalyst, etc.

In the case of living anionic polymerization, initiators such as organolithium compounds and organosodium compounds are generally used. The organolithium compound includes alkyllithiums such as n-butyllithium, sec-butyllithium, and t-butyllithium, all of which are preferably used. In addition, solvents used during polymerization include: hexane, heptane, methylcyclopentane, cyclohexane, benzene, toluene, xylene, 2-methylbutene-1, 2-methylbutene-2 and other hydrocarbon solvents. The way of living anion polymerization can be batch type or continuous type, and the polymerization temperature is usually in the range of 0-120°C.

In the case of living anionic polymerization, ethers, tertiary amines, alcoholates of alkali metals (sodium, potassium, etc.), phenates, sulfonates, and the like can be used in combination. The type, usage amount, and the like can be appropriately selected so that the ratio of the number of conjugated diene units having an ethylenically unsaturated bond in the side chain to the number of all conjugated diene units in the obtained hydrogenated block copolymer can be easily controlled.

In addition, the molecular weight of the polymer can be increased by adding a multifunctional coupling agent or crosslinking agent immediately before the termination of the living anionic polymerization to cause a coupling reaction or crosslinking.

Coupling agents are: divinylbenzene, 1,2,4-trivinylbenzene, epoxidized 1,2-polybutadiene, epoxidized soybean oil, epoxidized linseed oil, benzene-1, 2,4-triisocyanate, diethyl oxalate, diethyl malonate, diethyl adipate, dioctyl adipate, dimethyl phthalate, diethyl phthalate, terephthalate Diethyl phthalate, diethyl carbonate, 1,1,2,2-tetrachloroethane, 1,4-bis(trichloromethyl)benzene, trichlorosilane, methyltrichlorosilane, butyl Trichlorosilane, tetrachlorosilane, (dichloromethyl)trichlorosilane, hexachlorodisilane, tetraethoxysilane, tin tetrachloride, 1,3-dichloro-2-acetone, and the like. Among them, divinylbenzene, epoxidized 1,2-polybutadiene, trichlorosilane, methyltrichlorosilane, and tetrachlorosilane are preferable.

Crosslinking agents are: divinylbenzene, adipate diester, epoxidized liquid butadiene, epoxidized soybean oil, epoxidized linseed oil, xylene diisocyanate, diphenylmethane diisocyanate, 1 , 2,4-Benzene triisocyanate, etc.

The desired hydrogenated dihydrogenated polymer can be produced by reacting the above obtained polymer before hydrogenation, for example, in a hydrocarbon solvent, in the presence of a hydrogenation catalyst, at a hydrogen pressure of 1-100 kg/cm ² , and at a temperature range of -10 to 150°C. vinyl polymers.

The hydrogenation catalyst can use a compound containing metal elements selected from Ti, V, Co, Ni, Zr, Ru, Rh, Pd, Hf, Re, Pt, etc. . These compounds include: metallocene compounds containing Ti, Zr, Hf, Co, Ni, Pd, Pt, Ru, Rh, Re and other elements, and Pd, Ni, Pt, Rh, Ru and other metals are supported on carbon, di Supported heterogeneous catalysts on carriers such as silica, alumina, diatomaceous earth, etc. Homogeneous Ziegler-type catalysts that combine organic salts of elements such as Ni and Co or acetylacetonate salts with reducing agents such as organoaluminum , Ru, Rh and other organometallic compounds or complexes, fullerenes with hydrogen adsorbed, carbon nanotubes, etc. These hydrogenation catalysts may be used alone or in combination of two or more. Among them, metallocene compounds containing elements selected from Ti, Zr, Hf, Co, and Ni, metallocene compounds containing elements selected from Ti, Zr, and Hf that can be hydrogenated in an inert organic solvent and in a homogeneous system are preferred. compound. A low-cost, industrially practical hydrogenation catalyst obtained by reacting a titanocene compound and an alkyllithium is also preferred.

After hydrogenation, if necessary, the residue of the catalyst may be removed, or a phenolic or amine antioxidant may be added, and the resulting hydrogenated diene polymer may be separated from the reaction solution. Isolation of the hydrogenated diene polymer can be carried out, for example, by adding acetone, alcohol, etc. to the reaction solution to precipitate it; by adding the reaction solution to hot water with stirring, and then distilling off the solvent.

The following commercial items can also be used for the said hydrogenated diene polymer. For example, "Septon" (hydrogenated styrene-butadiene-isoprene block copolymer, the preferred grades are 4044, 4055, 4077, etc. 8007, 8004, 8006, etc.), "Hibura", etc., "Taftec" manufactured by Asahi Kasei Co., Ltd. (preferable grades are H1052, H1031, H1041, H1051, H1062, H1943, H1913, H1043, H1075, JT-90P, etc.) etc., "Dynalon" manufactured by JSR Corporation (preferable grades of hydrogenated styrene-butadiene block copolymers are 8600, 8900, etc.), etc., "Clayton" manufactured by Clayton Polymers Co., Ltd. (hydrogenated styrene-butadiene block copolymer) Preferred grades of block copolymers are G1650, G1651, G1652, G1657, etc.) and the like.

When the total of EAO-based copolymer [A], polyolefin-based resin [B], and mineral oil-based softener [C] is 100 parts by mass, the hydrogenated The content of the diene polymer [D] is 0.1-50 parts by mass, preferably 0.5-45 parts by mass, more preferably 1-40 parts by mass. When there is too much content of the said hydrogenated diene-type polymer [D], the flowability of the thermoplastic elastomer composition obtained may deteriorate. If the amount is too small, the mineral oil-based softener [C] may bleed out.

At this time, the content combinations of ethylene·α-olefin copolymer [A], polyolefin resin [B], and mineral oil softener [C] are 5 to 60% when the total of them is 100% by mass. Mass %, 1-20 mass % and 30-94 mass %, preferably 10-58 mass %, 3-18 mass % and 32-87 mass %, more preferably 15-55 mass %, 5-15 mass % and 35- 80% by mass.

When the total of oil-extended rubber [X], polyolefin-based resin [B1], and mineral oil-based softener [C2] is taken as 100 parts by mass, the hydrogenated dihydrogen contained in the thermoplastic elastomer composition according to the second aspect of the present invention The content of the ethylenic polymer [D1] is 0.1-50 parts by mass, preferably 0.5-45 parts by mass, more preferably 1-40 parts by mass. When there is too much content of the said hydrogenated diene-type polymer [D1], the fluidity|fluidity of the thermoplastic elastomer composition obtained may worsen. If the amount is too small, the mineral oil-based softener [C2] may bleed out.

The thermoplastic elastomer compositions according to the first and second aspects of the present invention may contain other polymer components in addition to the ethylene·α-olefin copolymer, polyolefin resin and hydrogenated diene polymer. Other polymer components are not particularly limited as long as they do not hinder the mechanical strength, flexibility, and the like of the obtained thermoplastic elastomer composition.

The polymer components include: ionomer resin, aminoacrylamide polymer, polyethylene maleic anhydride graft copolymer, polyisobutylene, ethylene-vinyl chloride copolymer, ethylene-vinyl alcohol copolymer, ethylene-vinyl acetate Copolymer, polyethylene oxide, ethylene-acrylic acid copolymer, polypropylene maleic anhydride graft polymer, polyisobutylene and its maleic anhydride graft polymer, chlorinated polypropylene, 4-methylpentene-1 Resin, polystyrene, ABS resin, ACS resin, AS resin, AES resin, ASA resin, MBS resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinylidene chloride resin, polyamide resin, polycarbonate, vinyl Alcohol resin, vinyl acetal resin, fluororesin, polyether resin, polyethylene terephthalate, nitrile rubber and its hydrogenated product, acrylic rubber, silicone rubber, fluororubber, butyl rubber, natural rubber, chlorine Polyethylene-based thermoplastic elastomers, syndiotactic 1,2-polybutadiene, purely blended olefin-based thermoplastic elastomers, our own blended olefin-based thermoplastic elastomers, polyvinyl chloride-based thermoplastic elastomers, Polyurethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and fluorine-based thermoplastic elastomers. These polymer components may be used alone or in combination of two or more.

5. Additives

In addition to the above-mentioned components, the thermoplastic elastomer composition of the present invention may also contain antioxidants, antistatic agents, blocking agents, sealability improvers, lubricants, anti-aging agents, heat stabilizers, weather-resistant agents, metal passivators Antibacterial and antifungal agents, dispersants, plasticizers, nucleating agents, flame retardants, tackifiers, foaming aids, dyes, pigments ( Titanium oxide, etc.), colorants such as carbon black, metal powders such as ferrite, inorganic fibers such as glass fibers and metal fibers, organic fibers such as carbon fibers and aramid fibers, composite fibers, inorganic whiskers such as potassium titanate whiskers , glass beads, glass balls, glass flakes, asbestos, mica, calcium carbonate, talc, wet silica, dry silica, alumina, silica alumina, calcium silicate, hydrotalcite, kaolin, diatomaceous earth, graphite , pumice, bakelite powder, cotton dust, cork powder, barium sulfate, fluororesin, polymer beads and other fillers or their mixtures, polyolefin wax, cellulose powder, rubber powder, wood powder and other fillers, low molecular weight polymers and other additives.

6. Thermoplastic elastomer composition

The thermoplastic elastomer composition of the present invention is obtained by dynamically heat-treating at least ethylene·α-olefin-based copolymer and polyolefin-based resin in the presence of a crosslinking agent. That is, it contains a crosslinked ethylene·α-olefin copolymer and a crosslinked polyolefin resin. In addition, if the hydrogenated diene polymer used in the production is an uncrosslinked product, it can also be crosslinked by dynamic heat treatment. "Dynamic heat treatment" refers to the process of applying shear force and heating.

The above-mentioned cross-linking agent is not particularly limited, and it is preferable that the EAO-based copolymer and the polyolefin-based resin can each be cross-linked by dynamic heat treatment at or above the melting point of the polyolefin-based resin, or the EAO-based copolymer and the polyolefin-based resin can be cross-linked. A compound in which both olefin-based resins are cross-linked.

The above-mentioned crosslinking agents include: organic peroxides, phenolic crosslinking agents, sulfur, sulfur compounds, p-benzoquinone, derivatives of p-benzoquinone dioxime, bismaleimide compounds, epoxy compounds, silane compounds, Amino resins, polyol crosslinking agents, polyamines, triazine compounds, metal soaps, etc. They may be used alone or in combination of two or more. Of these, organic peroxides and phenolic resin crosslinking agents are preferred.

Organic peroxides include: 1,3-bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3,2, 5-Dimethyl-2,5-bis(tert-butylperoxy)hexene-3, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, 2,2' -Bis(tert-butylperoxy)-p-cumene, dicumyl peroxide, di-tert-butyl peroxide, tert-butyl peroxide, p-menthyl peroxide, 1,1-bis(tert-butyl peroxy)-3,3,5-trimethylcyclohexane, dilauroyl peroxide, diacetyl peroxide, tert-butyl peroxybenzoate, 2,4-dichlorobenzoyl peroxide, p-chloro Benzoyl peroxide, benzoyl peroxide, bis(tert-butylperoxy)perbenzoate, n-butyl-4,4-bis(tert-butylperoxy)valerate, tert-butylperoxy Oxyisopropyl carbonate, etc. They may be used alone or in combination of two or more. Among them, preferred: 1,3-bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl-2,5-bis(tert-butylperoxy)hexyne-3,2,5- Dimethyl-2,5-di(tert-butylperoxy)hexane and α,α-bis(tert-butylperoxy)diisopropylbenzene, dicumyl peroxide, di-tert-butyl peroxide.

Phenolic crosslinking agents include, for example, p-substituted phenolic compounds represented by the following general formula (I), ortho-substituted phenol-aldehyde condensates, meta-substituted phenol-aldehyde condensates, brominated alkylphenol-aldehyde condensates, etc. . They may be used alone or in combination of two or more. Among them, p-substituted phenolic compounds are preferred.

[chemical 1]

In the above general formula (I), X is a hydroxyl group, a haloalkyl group or a halogen atom, R is a saturated hydrocarbon group with 1-15 carbon atoms, and n is an integer of 0-10.

The p-substituted phenol compound can be obtained by condensation reaction of p-substituted phenol and aldehyde (preferably formaldehyde) in the presence of a base catalyst.

Relative to 100 parts by mass of the total amount of polymer components used in the preparation of the thermoplastic elastomer composition of the present invention, the amount of the above-mentioned crosslinking agent used is preferably 0.01-20 parts by mass, more preferably 0.1-15 parts by mass, and even more preferably 1-10 parts by mass.

When an organic peroxide is used as the above-mentioned crosslinking agent, it is preferably 0.05-10 parts by mass, more preferably 0.1-5 parts by mass. If the amount of the organic peroxide used is too large, the crosslinking will be too high, resulting in poor moldability and mechanical properties. If it is too small, the degree of crosslinking will be insufficient, and the rubber elasticity and mechanical strength of the obtained thermoplastic elastomer composition may decrease.

When using a phenolic crosslinking agent as the above-mentioned crosslinking agent, it is preferably 0.2-10 parts by mass, more preferably 0.5-5 parts by mass. If the amount of the phenolic crosslinking agent used is too large, moldability tends to deteriorate. If it is too small, the degree of crosslinking will be insufficient, and the rubber elasticity and mechanical strength of the obtained thermoplastic elastomer composition may decrease.

When the above-mentioned crosslinking agent is used in combination with a crosslinking auxiliary agent or a crosslinking accelerator, the crosslinking reaction can be stably performed, and in particular, uniform crosslinking can be formed. In particular, when an organic peroxide is used as the above-mentioned crosslinking agent, it is preferable to use sulfur, sulfur compounds (sulfur powder, colloidal sulfur, precipitated sulfur, insoluble sulfur, surface-treated sulfur, dipentylenethiuram tetrasulfide, etc.), oxime Compounds (p-benzoquinone oxime, p, p'-dibenzoylquinone oxime, etc.), multifunctional monomers (ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, Triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, phthalate Diallyl formate, tetraallyloxyethane, triallyl cyanurate, N,N'-m-phenylene bismaleimide, N,N'-methylphenylene Bismaleimide, maleic anhydride, divinylbenzene, zinc di(meth)acrylate, etc.) and other crosslinking aids. They may be used alone or in combination of two or more. Among them, p,p'-dibenzoylquinone oxime, N,N'-m-phenylene bismaleimide, and divinylbenzene are preferable.

Among the above-mentioned crosslinking aids, N,N'-m-phenylene bismaleimide acts as a crosslinking agent, so it can also be used as a crosslinking agent.

When using an organic peroxide as the above-mentioned crosslinking agent, the amount of the crosslinking aid used is preferably 10 parts by mass or less, more preferably Preferably 0.2-5 parts by mass. If the amount of the cross-linking assistant used is too large, the cross-linking will be too high, the molding processability will decrease, and the mechanical properties will tend to decrease.

When using a phenolic cross-linking agent as the above-mentioned cross-linking agent, metal halides (stannous chloride, ferric chloride, etc.), organic halides (chlorinated polypropylene, bromobutyl rubber, chloroprene rubber, etc. ) and other cross-linking accelerators can be used in combination to adjust the cross-linking speed. More preferably, a metal oxide such as zinc oxide or a dispersant such as stearic acid is used in combination in addition to the crosslinking accelerator.

The thermoplastic elastomer composition of the present invention contains a cross-linked ethylene/α-olefin copolymer, and the content of the cross-linked ethylene/α-olefin copolymer can be evaluated by the cyclohexane-insoluble component. That is, the cyclohexane-insoluble content of the ethylene-α-olefin copolymer contained in the thermoplastic elastomer composition of the present invention is preferably 60% by mass or more, more preferably 65% by mass or more, and still more preferably 70% by mass at 23°C. % by mass or more. If the cyclohexane-insoluble content is less than 60% by mass, rubber elasticity and mechanical strength may decrease. The method for measuring the cyclohexane-insoluble content is as follows.

<Measurement method of insoluble content of cyclohexane>

Weigh about 200 mg of the thermoplastic elastomer composition and chop finely. The resulting flakes were then soaked in 100 ml of cyclohexane at 23° C. for 48 hours in a closed container. Next, this cyclohexane solution was filtered, and the residue on the filter paper was dried with a vacuum dryer (105° C.) for 1 hour. Subtract the mass of the dry residue and the amount of theoretical mineral oil softener in the thermoplastic elastomer composition from the mass of the thermoplastic elastomer composition before soaking, and take this value (soluble non- cross-linked ethylene·α-olefin copolymer) as "corrected final mass (p)".

On the other hand, the mass of the ethylene-α-olefin-based copolymer (the total amount of [A], [A1]) was obtained from the mass of the thermoplastic elastomer composition before soaking, and this was used as the "initial mass after correction ( q)".

The cyclohexane-insoluble fraction (insoluble components in the EAO copolymer/total amount of the EAO copolymer) can be obtained by the following formula.

Cyclohexane insoluble matter [mass %]=[{final mass after correction (p)}÷{initial mass after correction (q)}]×100.

The Shore E hardness (according to JIS K6253) of the thermoplastic elastomer composition of the present invention is preferably 80 or less, more preferably 75 or less, further preferably 70 or less.

7. Preparation method of thermoplastic elastomer composition

The method for producing the thermoplastic elastomer composition of the present invention is not particularly limited as long as it contains an ethylene·α-olefin copolymer and a polyolefin resin that are dynamically heat-treated in the presence of a crosslinking agent.

The conventional method is to prepare a raw material composition containing ethylene-α-olefin copolymer, polyolefin resin, mineral oil softener, hydrogenated diene polymer and crosslinking agent, and perform dynamic heat treatment on the raw material composition .

Other methods include: (i) preparing a raw material composition containing ethylene·α-olefin copolymer (or oil-extended rubber), polyolefin resin and crosslinking agent, performing dynamic heat treatment on the raw material composition, and then adding other raw materials The method of composition; (ii) prepare the raw material composition that contains ethylene. Dynamic heat treatment, followed by methods of adding other raw material components, etc.

The ethylene/α-olefin copolymer, polyolefin resin, and hydrogenated diene polymer used in preparing the raw material composition may be used as they are, or may be used separately as compositions containing the same or different additives. In addition, when the ethylene·α-olefin copolymer is used, it can be in any form of sack, granule, chip, powder (including crushed product of sack or chip), and ethylene·α with different shapes can also be used. - Olefin-based copolymers are used in combination.

Ethylene-α-olefin-based copolymer [A], polyolefin-based resin [B], and mineral oil-based softener [C] in all raw material components (I) used to prepare the thermoplastic elastomer composition of the first aspect The combination of content is 5-60 mass%, 1-20 mass% and 30-94 mass% when their total is 100 mass%, preferably 10-58 mass%, 3-18 mass% and 32-87 mass%. % by mass, more preferably 15-55% by mass, 5-15% by mass and 35-80% by mass.

In order to prepare the thermoplastic elastomer composition of the second aspect, an oil-extended rubber [X] containing an ethylene-α-olefin copolymer [A1] and a mineral oil-based softener [C1] is prepared in advance, and the oil-extended rubber [X] ] used together with other raw material components such as cross-linking agent.

The contents of oil-extended rubber [X], polyolefin-based resin [B1], and mineral oil-based softener [C2] in all raw material components (II) used to prepare the thermoplastic elastomer composition of the first aspect are combined in their When the total is 100% by mass, it is respectively 5-60% by mass, 1-20% by mass and 30-94% by mass, preferably 10-58% by mass, 3-18% by mass and 32-87% by mass, more preferably 15% by mass -55% by mass, 5-15% by mass and 35-80% by mass.

When preparing a thermoplastic elastomer composition, the apparatus used for "dynamic heat treatment" includes a melt kneading apparatus and the like. The treatment by this melting and kneading device may be continuous or batch.

The melt kneading device includes, for example, an open kneading roll, a non-open Banbury mixer, a single-screw extruder, a twin-screw extruder, a continuous kneader, a pressurized kneader, and the like. Among them, continuous melting and kneading devices such as single-screw extruders, twin-screw extruders, and continuous kneading machines are preferably used from the viewpoints of economy, processing efficiency, and the like. The continuous melting and kneading device can use two or more same or different devices in combination.

When the above-mentioned twin-screw extruder is used, it is preferable that L/D (ratio of screw effective length L to outer diameter D) is 30 or more, more preferably 36-60. As the twin-screw extruder, for example, any twin-screw extruder such as two intermeshed or non-intermeshed screws can be used, and a twin-screw extruder in which the two screws rotate in the same direction and are intermeshed is more preferable.

The twin-screw extruders include: "PCM" manufactured by Ikegai, "KTX" manufactured by Kobe Steel, "TEX" manufactured by Nippon Steel, "TEM" manufactured by Toshiba Machinery, and ワ一"ZSK" manufactured by Naichi Co., Ltd., etc.

When the above-mentioned continuous kneader is used, it is preferable that L/D (ratio of screw effective length L to outer diameter D) is 5 or more, more preferably L/D is 10.

Examples of the continuous kneader include "Mixtron KTX·LCM·NCM" manufactured by Kobe Steel Works, "CIM·CMP" manufactured by Nippon Steel Works, Ltd., and the like.

The treatment temperature during the dynamic heat treatment is usually 120-350°C, preferably 150-290°C. The treatment time is usually 20 seconds to 320 minutes, preferably 30 seconds to 25 minutes. In addition, the shear force applied to the mixture is: a shear rate of 10-20,000/sec, preferably 100-10,000/sec.

The thermoplastic elastomer composition obtained above has low hardness, especially Shore E and Shore A hardness, has flexibility, and is excellent in rubber elasticity. Therefore, when a molded article containing only this thermoplastic elastomer composition is produced according to the purpose and application, the above-mentioned excellent properties can be exhibited. Methods for producing molded articles containing the thermoplastic elastomer composition of the present invention include, for example, extrusion molding, calender molding, solvent casting, injection molding, vacuum molding, powder slush molding, and hot pressing.

8. Molded products

The molded article of the present invention is characterized by comprising the above-mentioned thermoplastic elastomer composition.

The molded article of the present invention can be made into a composite article by laminating, bonding, or the like with members containing other materials.

Examples of other materials include rubber, resin, thermoplastic elastomer compositions other than the present invention, metal (alloy), glass, cloth, wood, and the like.

As the rubber and resin, those exemplified as other polymer components that can be mixed with the thermoplastic elastomer composition of the present invention can be used.

Metals (alloys) include: stainless steel, aluminum, iron, copper, nickel, zinc, lead, tin, or nickel-zinc alloys, iron-zinc alloys, and lead-tin alloys used in automobiles, ships, and home appliances.

9. Sealing materials containing thermoplastic elastomer compositions:

Among the thermoplastic elastomer compositions of the present invention, those having a Shore A hardness of 40 or less, preferably 35 or less, more preferably 30 or less, particularly preferably 22 or less as measured according to JIS K6253 are preferably used as sealing materials. The compression set of the thermoplastic elastomer composition measured according to JIS K6262 (measurement conditions: 70° C., 22 hours) is preferably 40% or less, more preferably 38% or less, more preferably 35% or less. A sealing material made of a thermoplastic elastomer composition having the above characteristics has excellent sealing performance, and at the same time, mineral oil-based softener does not bleed out, and since it is composed of a thermoplastic elastomer composition, it can be recycled easily Utilization is excellent in saving resources.

As a method for producing a sealing material containing the thermoplastic elastomer composition of the present invention, for example, extrusion molding, calender molding, solvent casting, injection molding, vacuum molding, powder slush molding, and hot pressing can be used.

The shape of the obtained sealing material is not particularly limited, and examples thereof include an O-ring shape, a sheet shape, a rod shape, and the like. The sealing material can also be used as a plug.

The sealing material of the present invention can be formed into a sealing part, laminated, bonded, etc., with parts such as a box part containing other materials, and made into a composite product, such as a container such as a toner cartridge for a copier or a printer, etc. products. Here, other materials include, for example, rubber, resin, thermoplastic elastomer compositions other than the present invention, metal (alloy), glass, cloth, wood, and the like.

When it is made into a product such as a container, the above-mentioned various materials can be used for the box body, and it is preferably composed of a recyclable material. Among them, if the box part contains a thermoplastic resin and/or a thermoplastic elastomer composition, it is possible and easy to recycle, which is preferable.

The recyclable thermoplastic resin, thermoplastic elastomer, and thermoplastic elastomer composition are preferably used among the compounds listed as other polymer synthesis components in the description of the raw material composition for forming the thermoplastic elastomer composition Thermoplastic substances. Such as ionomer resin, aminoacrylamide polymer, polyethylene and its maleic anhydride graft polymer, polyisobutylene, ethylene vinyl chloride copolymer, ethylene vinyl alcohol copolymer, ethylene vinyl acetate copolymer, poly Ethylene oxide, ethylene-acrylic acid copolymer, polypropylene and its maleic anhydride graft copolymer, polyisobutylene and its maleic anhydride graft copolymer, chlorinated polypropylene, 4-methylpentene-1 resin, Polystyrene, ABS resin, ACS resin, AS resin, AES resin, ASA resin, MBS resin, acrylic resin, methacrylic resin, vinyl chloride resin, vinylidene chloride resin, polyamide resin, polycarbonate, vinyl alcohol resin , vinyl acetal resin, fluororesin, polyether resin, polyethylene terephthalate, chlorinated polyethylene-based thermoplastic elastomer, syndiotactic 1,2-polybutadiene, simple blend type Olefin-based thermoplastic elastomers, our own blended olefin-based thermoplastic elastomers, dynamic cross-linked olefin-based thermoplastic elastomers, polyvinyl chloride-based thermoplastic elastomers, polyurethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamides It is a thermoplastic elastomer and a fluorine-based thermoplastic elastomer. These polymer components may be used alone or in combination of two or more.

If an olefin-based material having good compatibility with the sealing material is selected as the material for the case side, a container in which the case part and the sealing part are thermally fused can be obtained. On the other hand, if a material with poor compatibility with the sealing material (for example, a thermoplastic resin containing functional groups) is selected as the material of the casing, the sealing portion and the casing can be composited without fusion.

Specifically, the box side materials with good compatibility with the sealing material include polypropylene or polyethylene, and the box side materials with poor compatibility with the sealing material include ABS resin, polycarbonate, and polystyrene.

The container of the present invention can also use materials other than thermoplastic resin or thermoplastic elastomer composition - metal (alloy), glass, cloth, wood etc., for example, metal (alloy) has: stainless steel, aluminum, iron, copper, nickel , zinc, lead, tin, or nickel-zinc alloys, iron-zinc alloys, lead-tin alloys, etc. used in automobiles, ships, and home appliances.

The sealing material of the present invention can be formed into a container (case with a seal) by forming it into a seal and preferably compounding it with a box by injection molding. In this container, the sealing portion containing the sealing material of the present invention exhibits extremely excellent sealing performance when containing contents such as powder such as toner or liquid.

The methods of compounding by injection molding include: core backing method, die slide method, rotation method, etc. Two-color or two or more resins are sequentially injected into the mold from different injection plastic cylinders. Internal injection filling, a method of making molded products of different materials or materials of different colors. Multiple injections can also form multi-layer or multi-color moldings.

Rotary method means that the material of the first color (first material) is injected from the first barrel, the mold is opened, and the primary molded product is attached to the side of the mold core. In this state, the mold rotating disk is rotated 180 degrees. Clamping the mold, injecting the material of the second color (second material) from the second cylinder, opening the mold again, and taking out the molded product from the mold, thereby manufacturing a composite injection molded product.

The mold core regression method includes primary molding and secondary molding. During primary molding, a part of the mold cavity is closed with a moving core, and molten resin is injected into the vacated cavity to form a semi-molded product. , The method of withdrawing the moving mold core, injecting molten resin into the withdrawn space, and obtaining a molded product integrated with the primary molded product.

In the method of manufacturing a container using the sealing material of the present invention, die-slider injection (DSI) is used as a preferable molding method in injection molding. The DSI method is briefly described as follows.

First, a primary molded product (half mold of a hollow product) is molded by one shot in the mold closed state, and the mold is opened with the primary molded product left in the cavity. The mold is a movable structure through the mold slide mechanism provided on the injection molding machine. With this mechanism, the mold can be moved to a position where the primary molded products face each other. The mold is closed again, and the wrapping resin is injected twice, so as to wrap the joint part of the butt-joint primary molded product to form a whole. The above-mentioned hollow product molding method is described in, for example, "Progress of DSI Hollow Injection Molding Technology" (August 2002) by Plastic and Japanese Patent Laid-Open No. Sho 62-87315.

Example

The following examples are given to illustrate the present invention in detail, and the present invention is not limited by these examples. Unless otherwise specified, "%" and "parts" in the examples are based on mass.

Example 1

1. Preparation of thermoplastic elastomer composition

According to the ratio shown in Table 1, an oil extender containing the following ethylene-α-olefin copolymer and a mineral oil softener (hydrogenated paraffin mineral oil manufactured by Idemitsu Kosan Co., Ltd., trade name "Diana proses oil PW380") was prepared. Rubber (I). Then, according to the mixing ratio in Table 2, the oil-extended rubber (I), the following polyolefin-based resin, the above-mentioned mineral oil-based softener, hydrogenated diene-based polymer, cross-linking agent and cross-linking auxiliary agent were combined. Various additives are mixed to obtain a raw material composition. This raw material composition was put into a pressurized kneader (capacity 10 L, manufactured by Moriyama Co., Ltd.) heated to 150° C. in advance, and kneaded at 40 rpm (shear rate 200/second) for 15 minutes until the polyolefin resin melted, and each The ingredients are evenly dispersed. Then, the kneaded material in the molten state was passed through a feeder ruler (manufactured by Moriyama Co., Ltd.) to form pellets.

Next, according to the ratio shown in Table 2, the above-mentioned granules, cross-linking agent and cross-linking auxiliary agent were added into the Henschel mixer, and mixed for 30 seconds. Then use a twin-screw extruder (co-rotating fully meshing screws, the ratio L/D of the length L of the screw thread portion to the diameter D of the screw = 33.5, manufactured by Ikegai Corporation, model PCM45), at 200 ° C, residence time 1 minute 30 seconds, 300 rpm, and a shear rate of 400/sec for dynamic heat treatment and simultaneous extrusion to obtain a granular thermoplastic elastomer composition.

(1) Ethylene·α-olefin copolymer

(I) Ethylene·propylene·5-ethylidene-2-norbornene terpolymer

The amount of ethylene monomer units was 66 mol%, the amount of 5-ethylidene-2-norbornene monomer units was 4.5 mol%, and the intrinsic viscosity measured at 135°C in a decalin solvent was 5.5 dl/g.

(II) Ethylene·propylene·5-ethylidene-2-norbornene terpolymer

The amount of ethylene monomer units was 66 mol%, the amount of 5-ethylidene-2-norbornene monomer units was 4.5 mol%, and the intrinsic viscosity measured at 135°C in a decalin solvent was 2.7 dl/g.

(2) Polyolefin resin

(I) Crystalline polypropylene

The Nippon Polychem Co., Ltd. product name "Novatec FL25R" (density: 0.90 g/cm ³ , MFR (temperature: 230° C., load: 2.16 kg): 23 g/10 minutes) was used.

(II) Propylene·1-butene amorphous copolymer

Using Ube Reckisen Co., Ltd. product name "UBETAC APAO UT 2780" (acrylic monomer unit amount: 71 mol%, melt viscosity 8,000 cPs, density: 0.87 g/cm ³ , crystallinity by X-ray diffraction measurement: 0%, GPC measurement The polystyrene conversion number average molecular weight Mn: 6,500).

(3) Hydrogenated diene polymer

(I) Styrene-butadiene-isoprene hydrogenated diene polymer

The product of Clare Co., Ltd., trade name "Septon 4077" (amount of styrene monomer unit: 30 mol%, specific gravity: 0.91, hydrogenation rate: 98%, viscosity of toluene solution (30°C, concentration 5% by mass): 300 mPa·s, melt Bulk flow rate (230°C, 21.2N): no flow, undeterminable).

(II) Styrene-butadiene hydrogenated diene polymer

The product of Clare Co., Ltd. was used under the trade name "Septon 8006" (amount of styrene monomer unit: 30 mol%, specific gravity: 0.91, hydrogenation rate: 98%, viscosity of toluene solution (30°C, concentration 5% by mass): 42 mPa·s, melt Bulk flow rate (230°C, 21.2N): no flow, undeterminable).

(III) Styrene butadiene hydrogenated diene polymer

Clayton Polymers Co., Ltd., trade name "G1651" (amount of styrene monomer unit: 33 mol%, specific gravity: 0.91, hydrogenation rate: 99%, viscosity of toluene solution (30°C, concentration 5% by mass): 50 mPa·s , Melt flow rate (230°C, 21.2N): no flow, cannot be measured).

(4) Additives

(i) Cross-linking agent

The NOF Co., Ltd. product, brand name "Paichikisa 25B-40" (5-dimethyl-2,5-di(tert-butylperoxy)hexane) was used.

(ii) Cross-linking aids

Divinylbenzene (purity: 96%) manufactured by Nippon Steel Chemical Co., Ltd. was used.

(iii) Anti-aging agent

The Ciba Specialty Chemicals Co., Ltd. product name "Irganox 1010" (tetrakis[methylene 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane) was used.

[Table 1] Oil-extended rubber (I) (II) Composition (parts) Ethylene·α-olefin copolymer Intrinsic viscosity (dl/g) (I) 5.5 50 (II) 2.7 60 mineral oil softener 50 40

2. Evaluation of thermoplastic elastomer composition

The pellets of the thermoplastic elastomer composition obtained above were processed with an injection molding machine (manufactured by Nippon Steel Works, Model "N-100") to produce a sheet (test sheet) with a length of 120 mm, a width of 120 mm, and a thickness of 2 mm. Various evaluations were performed using this sheet. The results are recorded in Table 2 together.

(1) Melt flow rate (MFR)

According to JIS K7210, it was measured at 190°C and a load of 21N.

(2) Cyclohexane insoluble matter

Measured at 23°C according to the method described herein.

(3) Hardness (Shore E)

According to JIS K6253, the hardness is measured 5 seconds after the start of the measurement, and this is used as an index of softness.

(4) Hardness (Shore A)

According to JIS K6253, the hardness is measured 5 seconds after the start of the Shore A hardness measurement, and this is used as an index of softness.

(5) Tensile breaking strength and tensile breaking elongation

Measured in accordance with JIS K6251.

(6) Compression permanent deformation

Measured at 70°C for 22 hours in accordance with JIS K6262 as an indicator of rubber elasticity.

(7) Resilience

According to JIS K6255, use a リュプケ type resilience tester, measure at 23°C, and use it as an index of rubber elasticity.

(8) Molded appearance (bleeding test of mineral oil softener)

A rectangular test piece with a length of 40 mm and a width of 30 mm was punched out from the above-mentioned test piece, and the test piece was left to stand in a constant temperature bath at 50° C. for 168 hours, and then the appearance was visually observed and evaluated as follows.

○: Mineral oil-based softener does not bleed out

×: Leakage of mineral oil-based softener

[Table 2] Example comparative example 1 2 3 1 2 3 Ingredients (parts) Oil-extended rubber (I) 47 47 35 47 47 (II) 47 Polyolefin resin (I) 4 4 3 4 4 4 (II) 4 4 3 4 4 4 mineral oil softener 45 45 59 45 45 45 Hydrogenated diene polymer (I) 5 5 (II) 5 (III) 25 crosslinking agent 0.8 0.8 0.8 0.8 0.8 Crosslinking Auxiliary 0.6 0.6 0.6 0.6 0.6 anti aging agent 0.1 0.1 0.1 0.1 0.1 0.1 Total amount of mineral oil-based softener in the composition 68.5 68.5 76.5 44 68 68.5 Presence or absence of dynamic crosslinking have have have have have none physical properties MFR(190℃, 21N)[g/10min] 8 10 8 16 5 1 Cyclohexane insoluble [%] 87 85 86 81 84 29 Hardness (Shore E) 55 54 55 53 59 53 Hardness (Shore A) 26 twenty two twenty four 19 twenty two 19 Tensile breaking strength [MPa] 2.1 2 2.7 1.9 1.4 0.8 Tensile elongation at break [%] 770 750 780 720 740 930 Compression set[%] 29 33 19 37 37 90 Resilience[%] 57 57 68 57 56 55 Molded Appearance ○ ○ ○ x x x

Embodiment 2-3 and comparative example 1-2

Except having used each raw material component in the mixing ratio of Table 2, it carried out similarly to Example 1, obtained each thermoplastic elastomer composition, and evaluated it. The results are recorded in Table 2 together.

In Comparative Example 2, the oil-extended rubber (II) in Table 1 was prepared in the same manner as in Example 1 above, and the oil-extended rubber (II) and other raw material components were mixed at the mixing ratios in Table 2 to obtain each raw material composition.

Comparative example 3

The oil-extended rubber (I) was mixed with other raw material components according to the mixing ratio in Table 2 to obtain a raw material composition. This raw material composition was put into a pressurized kneader (capacity 10 L, manufactured by Moriyama Co., Ltd.) preheated to 150° C., and kneaded at 40 rpm (shear rate 200/sec) for 15 minutes until the polyolefin resin melted, and each component Disperse evenly. Then, the kneaded product in the molten state was pelletized by a feeder ruler (manufactured by Moriyama Co., Ltd.) to obtain a thermoplastic elastomer composition, which was evaluated. The results are recorded in Table 2 together.

From the results in Table 2, it can be seen that Comparative Example 1 does not contain a hydrogenated diene-based polymer, and the mineral oil-based softener bleeds from the surface of the molded article, resulting in poor appearance. Comparative Example 2 contained a hydrogenated diene polymer, but the intrinsic viscosity of the ethylene·α-olefin copolymer was lower than 3.5 dl/g, so the mineral oil softener bleed out and the appearance was poor. Comparative Example 3 is an example without dynamic crosslinking, and its tensile properties are poor, so its mechanical strength is insufficient, its compression set is high, its mineral oil-based softener oozes out, and its appearance is poor.

On the other hand, the thermoplastic elastomer compositions of Examples 1-3 have a hardness (Shore E) of 54-55 and a hardness (Shore A) of 22-26, which is very low in hardness and excellent in flexibility. In addition, the compression set is very small at 29-33%, and the resilience is very high at 57-68%, showing excellent rubber elasticity. In addition, no bleeding phenomenon was observed, and the appearance was good.

Embodiment 4-5, comparative example 4-5

1. Preparation of thermoplastic elastomer composition

Mix the following oil-extended rubber [X], polyolefin-based resin, mineral oil-based softener, hydrogenated diene-based polymer, and additives (excluding cross-linking agent and cross-linking auxiliary agent) according to the mixing ratio in Table 3, Granules were produced in the same manner as in Example 1.

Then, according to the ratio shown in Table 3, the above-mentioned granules, crosslinking agent and crosslinking auxiliary agent were added in the Henschel mixer, mixed for 30 seconds, and then carried out in the same way as in Example 1 with a twin-screw extruder. Dynamic heat treatment and extrusion to obtain three (A, B, C) granular thermoplastic elastomer compositions.

(1) Oil-extended rubber [X]

Oil-extended copolymer rubber 1: 50% by mass ethylene/propylene/5-ethylene-2-norbornene terpolymer (ethylene content is 66mol%, 5-ethylene-2-norbornene content is 4.5mol %, intrinsic viscosity is 5.5dl/g), 50% by mass of paraffin-based softener.

(2) Polyolefin resin

(I) Crystalline polypropylene

The Nippon Polychem Co., Ltd. product name "Novatec FL25R" (density: 0.90 g/cm ³ , MFR (temperature: 230° C., load: 2.16 kg): 23 g/10 minutes) was used.

(II) Propylene·1-butene amorphous copolymer

Using Ube Reckisen Co., Ltd., trade name "UBETAC APAO UT2780" (acrylic monomer unit amount: 71 mol%, melt viscosity: 8,000 cPs, density: 0.87 g/cm ³ , crystallinity by X-ray diffraction measurement: 0%, GPC measurement The polystyrene conversion number average molecular weight Mn: 6,500).

(3) Mineral oil-based softener

The product made by Idemitsu Kosan Co., Ltd., trade name "Diana Proses Oil PW90" (paraffinic mineral oil) was used.

(4) Hydrogenated diene polymer

(I) Styrene-butadiene-isoprene hydrogenated diene polymer

The product name "Septon 4077" manufactured by Kurare Corporation (the amount of styrene monomer units: 30 mol%, specific gravity: 0.91, hydrogenation rate: 98%, toluene solution viscosity (30° C., concentration: 5% by mass): 300 mPa·s, melt Bulk flow rate (230°C, 21.2N): no flow, undeterminable).

(5) Additives

(i) Cross-linking agent

The NOF Co., Ltd. product, brand name "Parhekisa 25B-40" (5-dimethyl-2,5-di(tert-butylperoxy)hexane) was used.

(ii) Cross-linking aids

Divinylbenzene (purity: 96%) manufactured by Nippon Steel Chemical Co., Ltd. is used

(iii) Anti-aging agent

The Ciba Specialty Chemicals Co., Ltd. product name "Ilganox 1010" (tetrakis[methylene 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate]methane) was used.

[table 3] A B C Ingredients (parts) Oil-extended rubber (I) 45 47 75 Polyolefin resin (I) 5 4 6 (II) 5 4 6 mineral oil softener 40 45 13 Hydrogenated diene polymer (I) 5 crosslinking agent 0.8 0.8 0.8 Crosslinking Auxiliary 0.6 0.6 0.6 anti aging agent 0.1 0.1 0.1 physical properties Cyclohexane insoluble fraction [%] 85 87 86 MFR(190℃, 21N) [g/10 minutes] 6 twenty two MFR(230℃, 49N) [g/10 minutes] 41 Hardness (Shore A) 20 twenty two 42 Tensile breaking strength [MPa] 2.7 2.8 4.2 Tensile elongation at break [%] 700 650 740 Compression set [%] 33 34 38 oil exudation ○ ○ ○

2. Evaluation of thermoplastic elastomer composition

The pellets of the three thermoplastic elastomer compositions obtained above were processed by an injection molding machine (manufactured by Nippon Steel Works, model "N-100") to produce a piece (test piece) with a length of 120 mm, a width of 120 mm, and a thickness of 2 mm. films for various evaluations. The results are recorded in Table 3 together.

(1) Oil leakage

After standing at 80° C. for 72 hours, the oil exudation property was visually evaluated.

○: Mineral oil-based softener does not bleed out

×: Leakage of mineral oil-based softener

3. Fabrication of containers with seals

In order to manufacture a container with a sealing portion, use 220EII-P2M (injection molding machine for two-color molding) manufactured by Nippon Steel Works, by mold slide injection molding (M-DSI method; trademark), polystyrene (Nippon Polysucilen Co., Ltd. Manufacturing, grade H230) forming one side of the box body (barrel temperature 210°C, mold temperature 50°C), and then continuously molding the sealing part side (barrel temperature 210°C, mold temperature 50°C) with a thermoplastic elastomer composition, A container with a seal is obtained. FIG. 1 shows the obtained container 10 with a sealed portion, and FIG. 2 is a photograph showing a state in which the sealed portion 1 containing the low-hardness sealing material of the present invention and the box body 2 constituting the sealed portion container 10 are separated.

4. Sealing performance evaluation method

(experimental method)

As shown in FIG. 3 , the container with sealing material (two-color molded product) 10 produced in the above 3 was filled with 90% water 15 . Next, the cap 11 was put on the container 10, and the ends were clamped with double clips (manufactured by Kokuyo Co., Ltd.: クリ-34, mouth width: 25 mm) 12 (eight pieces). 14 represents a seal. This container 10 was dropped on the corrugated cardboard 13 from a height of 1 meter, and it was checked whether the water in the container 10 leaked out. For each sample, 5 tests (n=5) were performed by changing the direction of drop. The results are shown in Table 4.

[Table 4] Example 4 Example 5 Comparative example 4 Comparative Example 5 thermoplastic elastomer composition A B C no sealing material no 1 2 1 2 1 2 1 1 ○ ○ ○ ○ ○ ○ x 2 ○ ○ ○ ○ ○ x x 3 ○ ○ ○ ○ x ○ x 4 ○ ○ ○ ○ ○ x x 5 ○ ○ ○ ○ x ○ x Toner cartridge leakage rate (%) 0 0 80 100

○: no leakage; ×: leakage.

(Evaluation results)

From the results shown in Table 4, it can be seen that the low-hardness sealing material (thermoplastic elastomer composition = A, B) of the present invention has no water leakage and good sealing performance. However, the sealing performance of the sealing material made of the thermoplastic elastomer composition with a hardness exceeding 40 is poor.

Industrial applicability

The thermoplastic elastomer composition of the present invention is excellent in softness and rubber elasticity (resilience, compression set), so it can be widely used in automobile bumpers, exterior moldings, window gaskets, door gaskets, duct gaskets, automotive Top and side beams, signs, inner dashboards, door trims, console boxes and other interior and exterior surface materials, weather strips, etc., leather seats that require scratch resistance, sealing materials for aircraft and ships, and interior and exterior surface materials, etc., civil engineering Building sealing materials, interior and exterior decoration surface materials or waterproof sheets, etc., general machinery and device sealing materials, etc., weak current components, water pipe seals, sealing materials, surface materials or casings in fuel cell stacks, etc., railway track seals parts, rollers for information equipment, cleaning blades, films for electronic components, protective films in the manufacturing process of flat panel displays (FPDs) such as semiconductors and liquid crystal display devices, sealing materials, image protection films such as photographs, decorative films for building materials, General processed products such as medical equipment parts, electric wires, daily miscellaneous goods, sporting goods, etc.

The low-hardness sealing material of the present invention can be processed by injection molding, extrusion molding, hollow molding, compression molding, vacuum molding, lamination molding, calendering molding, etc., and has extremely low hardness, excellent sealing performance, and no leakage of mineral oil softeners , small compression set and other properties are excellent, so it can be used as a sealing material for general machinery or equipment. In addition, the sealing material is composed of a thermoplastic elastomer composition, is recyclable, and is excellent in respect to the global environment and resource saving.

The container obtained by integrally molding the low-hardness sealing material and the box body through two-color injection molding will never leak when storing various contents, and can be used with peace of mind during use and transportation.

Claims (16)

1. A thermoplastic elastomer composition comprising 0.1 to 50 parts by mass of [D] a hydrogenated diene polymer per 100 parts by mass of the total of [A], [B], and [C], wherein [A] 5-60% by mass of an ethylene-α-olefin copolymer having an intrinsic viscosity of 3.5 dl/g or more as measured in a decalin solvent at 135°C, [B] being 1-20% by mass of a polyolefin-based resin, And [C] is 30-94% by mass of mineral oil-based softener, and the total of [A], [B] and [C] is 100% by mass; At least the [A] ethylene·α-olefin-based copolymer and the [B] polyolefin-based resin are dynamically heat-treated in the presence of a crosslinking agent. 2. A thermoplastic elastomer composition comprising 0.1 to 50 parts by mass of a hydrogenated diene polymer of [D1] relative to 100 parts by mass of the total of [X], [B1], and [C2], wherein [X] is 5-60% by mass of oil-extended rubber containing [A1] 20-80% by mass of an ethylene·α-olefin system having an intrinsic viscosity of 3.5 dl/g or more measured at 135°C in a decalin solvent A copolymer and [C1] 20-80% by mass of a mineral oil-based softener, wherein the total of [A1] and [C1] is 100% by mass; [B1] is 1-20% by mass of a polyolefin-based resin; and [C2] It is 30-94% by mass of mineral oil-based softener, wherein the total of [X], [B1] and [C2] is 100% by mass; At least the above-mentioned [A1] ethylene·α-olefin-based copolymer and the above-mentioned [B1] polyolefin-based resin are dynamically heat-treated in the presence of a crosslinking agent. 3. The thermoplastic elastomer composition according to claim 1 or 2, wherein the hydrogenated diene polymer [D] is at least one selected from the group consisting of polymers containing monomer units formed from conjugated diene compounds and a hydride of a polymer containing a monomer unit formed from a conjugated diene compound and a monomer unit formed from a vinyl aromatic compound. 4. The thermoplastic elastomer composition according to any one of claims 1 to 3, which has a Shore E hardness of 80 or less as measured according to JIS K6253. 5. The thermoplastic elastomer composition according to any one of claims 1-4, wherein, when the total of all monomer units comprising ethylene monomer units and monomer units formed from α-olefin compounds is 100 mol%, The content of ethylene monomer units constituting the above-mentioned ethylene·α-olefin copolymers [A] and [A1] is 35 to 95 mol%. 6. The thermoplastic elastomer composition according to any one of claims 1 to 5, wherein the mineral oil-based softeners [C], [C1] and [C2] are paraffin-based mineral oils. 7. The thermoplastic elastomer composition according to any one of claims 1-6, wherein the above-mentioned crosslinking agent is selected from 1,3-bis(tert-butylperoxyisopropyl)benzene, 2,5-dimethyl Base-2,5-bis(tert-butylperoxy)hexyne-3,2,5-dimethyl-2,5-bis(tert-butylperoxy)hexane, α,α-bis(tert-butyl organic peroxides of diisopropylbenzene, dicumyl peroxide and di-tert-butyl peroxide. 8. The thermoplastic elastomer composition according to any one of claims 1-7, wherein the cyclohexane-insoluble content of the ethylene-α-olefin copolymer in the thermoplastic elastomer composition at 23°C is 60% by mass or above. 9. A molded article comprising the thermoplastic elastomer composition according to any one of claims 1-8. 10. A low-hardness sealing material made of the thermoplastic elastomer composition according to any one of claims 1-8. 11. The low-hardness sealing material according to claim 10, which has a Shore A hardness of 40 or less as measured in accordance with JIS K6253. 12. The low-hardness sealing material according to claim 10 or 11, which is formed in any one shape selected from an O-ring shape, a sheet shape, and a rod shape. 13. A container comprising the low-hardness sealing material according to any one of claims 10-12 as a component. 14. A container formed by molding a composite body comprising a sealing part and a box body by injection molding, wherein the sealing part contains the low-hardness sealing material according to any one of claims 10-12. 15. The container according to claim 14, wherein the box part contains a thermoplastic resin and/or a thermoplastic elastomer composition and is recyclable. 16. A toner cartridge comprising the low-hardness sealing material according to any one of claims 10 to 12 as a constituent.

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