JP6466181B2 - Cross-linked foam - Google Patents

Description

  The present invention relates to a cross-linked foam, and more particularly to a cross-linked foam excellent in waterstop and the like.

  Conventionally, in structures such as buildings, vehicles, and electronic devices, water sealing, heat insulation, sound absorption, and the like are performed by filling a gap between the members with a sealing material. For example, roof tile doors in houses, sashes, shutters, outer joints, metal roof joints, windshield dams for cars, sunroofs, doors, cowl top seals, etc. Widely used in doors of vending machines and backs of refrigerators. In particular, sealing parts such as automobiles and home appliances are particularly required to be water-tight. For example, high water-stopping properties are required for automobile lamp cover seals and body seals.

  As such a sealing material, a foamed material such as ethylene-α-olefin-diene copolymer rubber (hereinafter also referred to as EPDM) is used. Since the foam has an appropriate repulsive force (compressive stress), it can follow and adhere to the unevenness of the surface of the sealing material with only a small amount of compressive deformation, and has excellent sealing properties.

  However, in order to meet the demand for further improvement in water-stopping properties, researches have been made such as improving hydrophobicity by adding wax and imparting adhesiveness by adhering an adhesive or adhesive polymer to adhere to the substrate.

  For example, Patent Document 1 discloses an EPDM foam obtained by foaming a rubber composition containing EPDM, a quinoid crosslinking agent and a foaming agent. Patent Document 2 discloses a rubber foam obtained by blending a rubber component with a softening agent, a filler, a foaming agent, a fluorine-based or silicone-based water repellent and a crosslinking agent, and crosslinking and foaming. . Patent Document 3 discloses a rubber foam obtained by blending an adhesive resin softener composed of EPDM, water repellency and petroleum wax and foam vulcanizing. Patent Document 4 discloses a rubber-based foam obtained by crosslinking and foaming a composition containing a softening agent composed of EPDM, a vulcanizing agent, a foaming agent, and an adhesive polymer. Patent Document 5 discloses a crosslinked foam obtained by crosslinking and foaming a composition containing a specific blend of EPDM, a vulcanizing agent and a foaming agent.

JP 2012-017452 A Japanese Patent Laid-Open No. 2002-164759 Japanese Patent Laid-Open No. 10-045933 JP 2002-146072 A JP 2013-11344 A

However, even such a conventional research has not yet yielded a foam that can sufficiently meet the demand for improvement in water stoppage. In particular, in an automobile lamp cover seal, it is important to improve adhesion with a base material (such as an automobile lamp cover). Moreover, the prescription which added the adhesive had problems, such as contamination.
An object of this invention is to provide the crosslinked foam excellent in the water-stopping property.

The present invention relates to the following [1] to [ 7 ], for example.
[1] An ethylene / α-olefin / non-conjugated polyene copolymer (A) in which a peak of loss tangent tan δ determined by dynamic viscoelasticity measurement is present at −60 ° C. or more and less than 0 ° C .;
a soft material (B) having a tan δ peak in a temperature range of 0 ° C. or more and 60 ° C. or less,
The specific gravity of the copolymer (A) and the soft material (B) is obtained from a composition containing a mass ratio (copolymer (A) / soft material (B)) of 100/5 to 100/35. 01-0.8 cross-linked foam.
[2] The α-olefin in the ethylene / α-olefin / non-conjugated polyene copolymer (A) is an α-olefin having 3 to 20 carbon atoms, and the soft material (B) is 4-methyl-1-pentene. The cross-linked foam according to the above [2], which is an α-olefin copolymer, and the α-olefin in the copolymer is an α-olefin having 2 to 20 carbon atoms excluding 4-methyl-1-pentene.
[3] In the ethylene / α-olefin / non-conjugated polyene copolymer (A), the content of the structural unit derived from ethylene is 40 to 72% by mass, and the content of the structural unit derived from the non-conjugated polyene Is a crosslinked foam according to the above [2], wherein the content is 2 to 15% by mass.
[4] The 4-methyl-pent emissions · alpha-olefin copolymer,
A structural unit derived from 4-methyl-1-pentene (i) of 16 to 95 mol%,
Structural unit (ii) derived from at least one α-olefin selected from α-olefins having 2 to 20 carbon atoms excluding 4-methyl-1-pentene 5 to 84 mol%
And a structural unit (iii) derived from a non-conjugated polyene, 0 to 10 mol%
(However, the total of the structural units (i), (ii) and (iii) is 100 mol%)
The cross-linked foam according to [2] or [3] above, which contains a 4-methyl-1-pentene / α-olefin copolymer (b-1) having the formula:
[5] The cross-linked foam according to [4], wherein the α-olefin of the 4-methyl-1-pentene / α-olefin copolymer (b-1) is propylene.
[6] A waterstop material obtained from the crosslinked foam according to any one of [1] to [5].
[7] An automotive sealing material obtained from the crosslinked foam according to any one of [1] to [5].

Since the crosslinked foamed body of the present invention has high adhesion to the substrate and excellent water-stopping properties, it can be used as a water-stopping material. In particular, it can be suitably used as an automobile lamp cover seal or body seal.
Moreover, the crosslinked foam of this invention has favorable adhesiveness with respect to a roll, and is excellent in roll processability.

FIG. 1 is an explanatory diagram of a water-stop measuring device used for water-stop measurement in Examples. FIG. 2 is an explanatory diagram of a water-stop measuring method in the examples.

  The crosslinked foam of the present invention comprises an ethylene / α-olefin / non-conjugated polyene copolymer (A) having a loss tangent tan δ peak determined by dynamic viscoelasticity measurement at −60 ° C. or more and less than 0 ° C., and It is obtained from a composition containing a soft material (B) having a tan δ peak in a temperature range of 0 ° C. or more and 60 ° C. or less. By blending the soft material (B) having a tan δ peak in the vicinity of room temperature, the effect of improving the uneven followability of the resulting crosslinked foam to the substrate is exhibited.

  First, the loss tangent tan δ obtained by dynamic viscoelasticity measurement will be described. The dynamic viscoelasticity measurement is performed on the material while continuously changing the ambient temperature, and the storage elastic modulus G ′ (Pa) and the loss elastic modulus G ″ (Pa) are measured and given by G ″ / G ′. The loss tangent tan δ is obtained. Looking at the relationship between the temperature and the loss tangent tan δ, the loss tangent tan δ generally has a peak at a specific temperature. The temperature at which the peak appears is generally called the glass transition temperature (hereinafter also referred to as tan δ-Tg). The temperature at which the peak of loss tangent tan δ appears can be determined based on the dynamic viscoelasticity measurement described in the examples.

  From the viewpoint of improving water-stopping properties, the ethylene / α-olefin / non-conjugated polyene copolymer (A) preferably has a loss tangent tan δ peak of −55 to −5 ° C., more preferably −50 to −10 ° C. The soft material (B) preferably has a loss tangent tan δ peak in the temperature range of 5 to 55 ° C, more preferably 10 to 50 ° C.

  In the composition containing the ethylene / α-olefin / non-conjugated polyene copolymer (A) and the soft material (B), the mass ratio of the copolymer (A) and the soft material (B) (copolymer ( A) / soft material (B)) is a ratio of 100/5 to 100/35, preferably 8 to 30, more preferably 10 to 20. When the mass ratio of the copolymer (A) and the soft material (B) is within the above range, the obtained crosslinked foam has improved adhesion to the base material and exhibits excellent waterstop properties. If the addition amount is less than the above range, the unevenness followability is insufficient, and if it is too much, the one once changed cannot be recovered and the water stoppage is lowered.

  Since the ethylene / α-olefin / non-conjugated polyene copolymer (A) has a loss tangent tan δ peak within a temperature range of −60 ° C. or more and less than 0 ° C., excellent water stopping properties can be obtained as described above. There is no particular limitation on the type.

  The α-olefin in the ethylene / α-olefin / non-conjugated polyene copolymer (A) is preferably an α-olefin having 3 to 20 carbon atoms. Examples of the α-olefin having 3 to 20 carbon atoms include propylene, butene-1,4-methylpentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1, and undecene-1. , Dodecene-1, tridecene-1, tetradecene-1, pentadecene-1, hexadecene-1, heptadecene-1, nonadecene-1, eicosene-1, 9-methyl-decene-1, 11-methyl-dodecene-1, 12 -Ethyl-tetradecene-1 etc. can be mentioned. Among these, propylene, 1-butene, 1-hexene, 1-octene and the like are particularly preferable. These α-olefins can be used alone or in combination of two or more.

  Examples of the non-conjugated polyene in the ethylene / α-olefin / non-conjugated polyene copolymer (A) include polyenes having 5 to 20 carbon atoms, preferably 5 to 10 carbon atoms. Pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,4-octadiene, 1,5-octadiene, 1,6-octadiene, 1,7-octadiene, 2-methyl-1,5-hexadiene, 6 -Methyl-1,5-heptadiene, 7-methyl-1,6-octadiene, 4-ethylidene-8-methyl-1,7-nonadiene, 4,8-dimethyl-1,4,8-decatriene, dicyclopentadiene , Cyclohexadiene, dicyclooctadiene, methylene norbornene, 5-vinyl norbornene, 5-ethylidene-2-norbornene, 5-methyl Len-2-norbornene, 5-vinylidene-2-norbornene, 5-isopropylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2-norbornene, 2,3-diisopropylidene-5-norbornene, 2 -Ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene and the like can be mentioned. Among these, dicyclopentadiene, 5-vinylidene-2-norbornene, 5-ethylidene-2-norbornene and the like are particularly preferable. These non-conjugated polyenes can be used alone or in combination of two or more.

  In the ethylene / α-olefin / non-conjugated polyene copolymer (A), the content of the structural unit derived from ethylene is 40 to 72 mass%, and the content of the structural unit derived from the non-conjugated polyene is 2 to 2%. It is preferably 15% by mass, the content of the structural unit derived from ethylene is 42 to 66% by mass, and the content of the structural unit derived from non-conjugated polyene is more preferably 5 to 14% by mass. Preferably, the content of structural units derived from ethylene is 44 to 62% by mass, and the content of structural units derived from non-conjugated polyene is more preferably 7 to 12% by mass.

  As long as the soft material (B) has a loss tangent tan δ peak in a temperature range of 0 ° C. or higher and 60 ° C. or lower, excellent water stoppage can be obtained as described above, and there is no particular limitation on the type. Examples of the soft material (B) include aromatic polymer, 4-methyl-1-pentene / α-olefin copolymer, polyvinyl acetate, polyester, polyurethane, poly (meth) acrylate, epoxy resin, and polyamide. Can be mentioned. The soft material (B) can be used by mixing them. The soft material (B) is preferably a 4-methyl-1-pentene / α-olefin copolymer from the viewpoint of improving the water-stopping property.

  Examples of the aromatic polymer include polymers of aromatic vinyl monomers such as styrene and alkylstyrene, and copolymers of aromatic vinyl monomers and olefin monomers. Specific examples include hydrogenated styrene / isoprene / styrene copolymers.

  The α-olefin in the 4-methyl-1-pentene / α-olefin copolymer is preferably an α-olefin having 2 to 20 carbon atoms excluding 4-methyl-1-pentene, linear or Examples include branched α-olefins, cyclic olefins, aromatic vinyl compounds, conjugated dienes, and functionalized vinyl compounds. In the 4-methyl-1-pentene / α-olefin copolymer, the α-olefin does not contain a non-conjugated polyene.

  Examples of the linear α-olefin include linear α-olefins having 2 to 20 carbon atoms, preferably 2 to 15 carbon atoms, more preferably 2 to 10 carbon atoms. Specifically, ethylene, propylene, 1 -Butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene and the like can be mentioned. Among these, ethylene, propylene, 1-butene, 1-pentene, 1-hexene and 1-octene are preferable.

  The branched α-olefin is preferably a branched α-olefin having 5 to 20 carbon atoms, more preferably 5 to 15 carbon atoms, specifically, 3-methyl-1-butene and 3-methyl. -1-pentene, 3-ethyl-1-pentene, 4,4-dimethyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-hexene, 4-ethyl-1-hexene, 3 -Ethyl-1-hexene and the like.

  Examples of the cyclic olefin include cyclic olefins having 3 to 20 carbon atoms, preferably 5 to 15 carbon atoms. Specifically, cyclopentene, cyclohexene, cycloheptene, norbornene, 5-methyl-2-norbornene, tetracyclodone. Examples include decene and vinylcyclohexane.

  Examples of aromatic vinyl compounds include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o, p-dimethylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene. And mono- or polyalkyl styrene.

  Examples of the conjugated diene include conjugated dienes having 4 to 20 carbon atoms, preferably 4 to 10 carbon atoms. Specific examples thereof include 1,3-butadiene, isoprene, chloroprene, 1,3-pentadiene, and 2,3-dimethyl. Examples thereof include butadiene, 4-methyl-1,3-pentadiene, 1,3-hexadiene, and 1,3-octadiene.

  Examples of the functionalized vinyl compound include a hydroxyl group-containing olefin, a halogenated olefin, (meth) acrylic acid, propionic acid, 3-butenoic acid, 4-pentenoic acid, 5-hexenoic acid, 6-heptenoic acid, 7-octenoic acid, Unsaturated carboxylic acids such as 8-nonenoic acid, 9-decenoic acid and 10-undecenoic acid, unsaturated amines such as allylamine, 5-hexenamine and 6-heptenamine, (2,7-octadienyl) succinic anhydride, penta Propenyl succinic anhydride, unsaturated carboxylic anhydride such as anhydride obtained from unsaturated carboxylic acid, unsaturated carboxylic acid halide such as halide obtained from unsaturated carboxylic acid, 4-epoxy-1 -Butene, 5-epoxy-1-pentene, 6-epoxy-1-hexene, 7-epoxy-1-heptene, 8-epoxy Unsaturated epoxy compounds such as cis-1-octene, 9-epoxy-1-nonene, 10-epoxy-1-decene, 11-epoxy-1-undecene, vinyltriethoxysilane, vinyltrimethoxysilane, 3-acryloxy Examples thereof include ethylenically unsaturated silane compounds such as propyltrimethoxysilane, γ-glycidoxypropyltripyltrimethoxysilane, γ-aminopropyltriethoxysilane, and γ-methacryloxypropyltrimethoxysilane.

  The hydroxyl group-containing olefin is not particularly limited as long as it is a hydroxyl group-containing olefin compound, and examples thereof include terminal hydroxylated olefin compounds. Examples of the terminal hydroxylated olefin compound include vinyl alcohol, allyl alcohol, hydroxyl-1-butene, hydroxyl-1-pentene, hydroxyl-1-hexene, hydroxyl-1-octene, hydroxyl-1-decene, 2-20 carbon atoms, such as hydroxyl-1-undecene, hydroxyl-1-dodecene, hydroxyl-1-tetradecene, hydroxyl-1-hexadecene, hydroxyl-1-octadecene, hydroxyl-1-octadecene, hydroxyl-1-eicosene, etc. Preferably 2 to 15 linear hydroxylated α-olefin, hydroxylated 3-methyl-1-butene, hydroxylated 3-methyl-1-pentene, hydroxylated 4-methyl-1-pentene, Hydroxylated-3-ethyl-1-pentene, hydroxylated-4,4-dimethyl-1-pentene, hydroxylated 4-methyl-1-hexene, hydroxylated-4,4-dimethyl-1-hexene, hydroxylated -4-D -1-hexene, preferably such as hydroxide-3-ethyl-1-hexene having 5 to 20 carbon atoms, or more preferably branched hydroxide -α- olefin having 5 to 15 carbon atoms.

  The halogenated olefin is a halogenated-α-olefin having a group 17 atom of the periodic table such as chlorine, bromine, iodine, etc., for example, vinyl halide, halogenated-1-butene, halogenated-1-pentene, Halogenated-1-hexene, halogenated-1-octene, halogenated-1-decene, halogenated-1-dodecene, halogenated-1-undecene, halogenated-1-tetradecene, halogenated-1-hexadecene, halogen A straight-chain halogenated α-olefin, halogenated-3-methyl-1-butene having 2 to 20 carbon atoms, preferably 2-15, such as chloro-1-octadecene, halogenated-1-eicosene, etc. Halogenated-4-methyl-1-pentene, halogenated-3-methyl-1-pentene, halogenated-3-ethyl-1-pentene, Rogenated-4,4-dimethyl-1-pentene, halogenated-4-methyl-1-hexene, halogenated-4,4-dimethyl-1-hexene, halogenated-4-ethyl-1-hexene, halogenated Preferred are branched halogenated α-olefins having 5 to 20 carbon atoms, more preferably 5 to 15 carbon atoms, such as -3-ethyl-1-hexene.

The α-olefin in the 4-methyl-1-pentene / α-olefin copolymer may be a single type or a combination of two or more types.
Examples of the α-olefin in the 4-methyl-1-pentene / α-olefin copolymer include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 3-methyl-1-butene, and 3-methyl. -1-pentene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene, norbornene, 5-methyl-2-norbornene, tetracyclodone Decene and hydroxyl-1-undecene are preferred. Further, a linear α-olefin having 2 to 10 carbon atoms is preferable, and ethylene, propylene, 1-butene, 1-pentene, 1-hexene and 1-octene are more preferable. Among these, ethylene and propylene are preferable, and propylene is particularly preferable.

  The cross-linked foam formed from the composition containing 4-methyl-1-pentene copolymer as the soft material (B) has excellent unevenness followability, so that the adhesion with the base material is increased and excellent water-stopping property is achieved. Demonstrate.

  The 4-methyl-1-pentene / α-olefin copolymer may have a structural unit derived from a non-conjugated polyene, if necessary. The non-conjugated polyene is the same as the non-conjugated polyene in the aforementioned ethylene / α-olefin / non-conjugated polyene copolymer (A).

The 4-methyl-1-pentene / α-olefin copolymer may contain other copolymerization components as long as the object of the present invention is not impaired.
The 4-methyl-1-pentene / α-olefin copolymer is a structural unit derived from 4-methyl-1-pentene (i), an α- of 2 to 20 carbon atoms excluding 4-methyl-1-pentene. 4-methyl-1-pentene / α-olefin copolymer having a structural unit (ii) derived from at least one α-olefin selected from olefins and a structural unit (iii) optionally derived from a non-conjugated polyene ( b-1) is preferably included. As the content of the structural unit (i), the structural unit (ii) and the structural unit (iii) in the 4-methyl-1-pentene / α-olefin copolymer (b-1), the structural unit (i), ( The total of ii) and (iii) is 100 mol%, preferably the structural unit (i) is 16 to 95 mol%, the structural unit (ii) is 5 to 84 mol%, and the structural unit (iii) is 0 to 10 mol%. More preferably, the structural unit (i) is 26 to 90 mol%, the structural unit (ii) is 10 to 74 mol%, the structural unit (iii) is 0 to 7 mol%, and more preferably the structural unit (i) 61 to 85. They are mol%, structural unit (ii) 15-39 mol%, and structural unit (iii) 0-5 mol%. When the content ratio of each structural unit is within the above range, higher adhesion between the obtained crosslinked foam and the base material can be obtained, and the water stoppage of the crosslinked foam is further improved. As the α-olefin in the 4-methyl-1-pentene / α-olefin copolymer (b-1), ethylene and propylene are preferable, and propylene is particularly preferable. When the α-olefin in the 4-methyl-1-pentene / α-olefin copolymer (b-1) is propylene, the structural unit (ii) is a structural unit derived from propylene.

  As described above, the crosslinked foam of the present invention comprises an ethylene / α-olefin / non-conjugated polyene copolymer (A) and a 4-methyl-1-pentene / α-olefin copolymer as a copolymer ( The mass ratio of A) to the soft material (B) (copolymer (A) / soft material (B)) is included at a ratio of 100/5 to 100/35, and the α-olefin in the copolymer (A) is The α-olefin having 3 to 20 carbon atoms is preferably obtained from a composition in which the α-olefin in the soft material (B) is an α-olefin having 2 to 20 carbon atoms excluding 4-methyl-1-pentene. .

The composition contains a foaming agent and a vulcanizing agent (crosslinking agent).
Examples of the foaming agent include inorganic foaming agents such as sodium bicarbonate and sodium carbonate; nitroso compounds such as N, N′-dinitrosopentamethylenetetramine and N, N′-dinitrosoterephthalamide; azodicarbonamide and azobisiso Organic foaming agents such as azo compounds such as butyronitrile; hydrazide compounds such as benzenesulfonyl hydrazide and 4,4′-oxybis (benzenesulfonyl hydrazide); azide compounds such as calcium azide and 4,4′-diphenyldisulfonyl azide Can be mentioned.

  The compounding quantity of a foaming agent is 3-30 mass parts with respect to 100 mass parts of copolymers (A), Preferably it is 4-20 mass parts. As the foaming agent, for example, commercially available vinylol AC # 3M (trade name, Eiwa Kasei Kogyo Co., Ltd., azodicarbonamide (abbreviated as ADCA)), binihol AC # 3C-K2 (brand name, Eiwa Kasei Kogyo Co., Ltd., azodicarbon) Amide (abbreviation ADCA)), VINYHALL AC # LQ (trade name, Eiwa Kasei Kogyo Co., Ltd. azodicarbonamide (abbreviation ADCA)), Cellmic C-2 (trade name, Sankyo Kasei Co., Ltd. azodicarbonamide (abbreviation ADCA)) , Cellular #D (trade name, Eiwa Kasei Kogyo Co., Ltd., N, N′-dinitrosopentamethylenetetramine (abbreviation DPT)), Cellular CK # 54 (trade name, Eiwa Kasei Kogyo Co., Ltd., N, N′-dinitrosopenta Methylenetetramine (abbreviation DPT)), Cell Microphone #A (trade name, Sankyo Kasei Co., Ltd. N, N'-Di Nitrosopentamethylenetetramine (abbreviation: DPT)), Neoselbon N # 1000SW (trade name, Eiwa Kasei Kogyo Co., Ltd. 4,4'-oxybis (benzenesulfonylhydrazide) (abbreviation: OBSH)), Neocerbon N # 1000M (trade name, Eiwa Kasei) Kogyo Co., Ltd. 4,4′-oxybis (benzenesulfonylhydrazide) (abbreviation OBSH)) and the like can be used.

  Moreover, you may contain a foaming auxiliary agent with a foaming agent. Examples of the foaming aid include organic acids such as salicylic acid, phthalic acid, stearic acid, oxalic acid, and citric acid, salts thereof, urea, and derivatives thereof. The blending amount of the foaming aid is 0.1 to 5 parts by mass, preferably 0.3 to 4 parts by mass with respect to 100 parts by mass of the copolymer (A). Examples of foaming aids are commercially available cell paste K5 (trade name, Eiwa Kasei Kogyo Co., Ltd. urea), cell paste 101W (trade name, Eiwa Kasei Kogyo Co., Ltd. urea), FE-507 (trade name, Eiwa). Kasei Kogyo Co., Ltd. baking soda) can be used.

As the vulcanizing agent (crosslinking agent), a sulfur compound, an organic peroxide, a phenol resin, an oxime compound, or the like can be used.
Examples of sulfur compounds include sulfur, sulfur chloride, sulfur dichloride, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, selenium dithiocarbamate, and the like. As the sulfur-based compound, sulfur and tetramethylthiuram disulfide are preferable, and usually 0.3 to 10 parts by weight, preferably 0.5 to 5.0 parts by weight, and 100 parts by weight of the copolymer (A). Preferably 0.7-4.0 mass parts can be mix | blended.

  Examples of the organic peroxide include dicumyl peroxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, 2, Examples include 5-diethyl-2,5-di (t-butylperoxy) hexyne-3, di-t-butylperoxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-dibutylhydroperoxide, etc. it can. Of these, dicumyl peroxide, di-t-butyl peroxide, and di-t-butylperoxy-3,3,5-trimethylcyclohexane are preferable. The compounding quantity of an organic peroxide is 0.001-0.05 mol normally with respect to 100 g of copolymers (A), Preferably it is 0.002-0.02 mol, More preferably, it is 0.005-0. 015 mol.

  When a sulfur compound is used as the vulcanizing agent, it is preferable to use a vulcanization accelerator in combination. Examples of the vulcanization accelerator include N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazole sulfenamide, N, N′-diisopropyl-2-benzothiazole sulfenamide, 2-mercapto Benzothiazole (for example, “Sunceller M” (trade name, manufactured by Sanshin Chemical Industry Co., Ltd.)), 2- (4-morpholinodithio) penzothiazole (for example, “Noxeller MDB-P” (trade name, Sanshin) Chemical Industry Co., Ltd.)), 2- (2,4-dinitrophenyl) mercaptobenzothiazole, 2- (2,6-diethyl-4-morpholinothio) benzothiazole, dibenzothiazyl disulfide and other thiazoles; Gua such as diphenyl guanidine, triphenyl guanidine, diorthotolyl guanidine Nidin type; acetaldehyde-aniline condensate, butyraldehyde-aniline condensate, aldehyde amine type; imidazoline type such as 2-mercaptoimidazoline; thiourea type such as diethylthiourea, dibutylthiourea; tetramethylthiuram monosulfide, tetramethylthiuram disulfide, etc. Thiuram series: zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, zinc dibutyldithiocarbamate (for example, “Suncellar PZ” (trade name, manufactured by Sanshin Chemical Co., Ltd.), “Suncellor BZ” (trade name, Sanshin Chemical Industries) Etc.), dithioate salts such as tellurium diethyldithiocarbamate; ethylenethiourea (for example, “Sunseller BUR” (trade name, manufactured by Sanshin Chemical Industry Co., Ltd.), “Sunseller 22-C” (trade name, Thiourea type such as N, N′-diethylthiourea, etc .; 2-mercaptobenzothiazole (eg “Sunseller M” (trade name, manufactured by Sanshin Chemical Industry Co., Ltd.)) thiazole type Vulcanization accelerators: xanthates such as zinc dibutylxatogenate.

The compounding amount of these vulcanization accelerators is 0.1 to 20 parts by mass, preferably 0.2 to 15 parts by mass, and more preferably 0.5 to 10 parts by mass with respect to 100 parts by mass of the copolymer (A). Part by mass.
Along with the vulcanizing agent, a vulcanization aid can be further used. Vulcanization aids can be appropriately selected depending on the application, and can be used alone or in combination of two or more. Specific examples of the vulcanization aid include magnesium oxide and zinc white (for example, zinc oxide such as “META-Z102” (trade name, manufactured by Inoue Lime Industry Co., Ltd.)). The compounding quantity is 1-20 mass parts normally with respect to 100 mass parts of copolymers (A). As vulcanization aids, quinone dioximes such as p-quinonedioxime; acrylics such as ethylene glycol dimethacrylate and trimethylolpropane trimethacrylate; allyls such as diallyl phthalate and triallyl isocyanurate; other maleimides Divinylbenzene and the like.

In addition to the components, the composition may contain a softening material, a reinforcing material, a filler, a processing aid, an activator, a hygroscopic agent, and the like within a range that does not impair the object of the present invention.
The softening material can be appropriately selected depending on its use, and can be used alone or in combination of two or more. Specific examples of the softening material include process oils such as paraffin oil (for example, “Diana Process Oil PS-430” (trade name, manufactured by Idemitsu Kosan Co., Ltd.), lubricating oil, liquid paraffin, petroleum asphalt, petrolatum, and the like. Oil-based softeners such as coal tar and coal tar pitch; fatty oil-based softeners such as castor oil, linseed oil, rapeseed oil, soybean oil, and palm oil; beeswax, carnauba wax, and Waxes such as lanolin; fatty acids such as ricinoleic acid, palmitic acid, stearic acid, barium stearate, calcium stearate, and zinc laurate or salts thereof; naphthenic acid, pine oil, and rosin or derivatives thereof; terpene resins, petroleum resins , Atactic polypropylene, coumarone indene resin, etc. Synthetic polymer materials: ester softeners such as dioctyl phthalate, dioctyl adipate, and dioctyl sebacate; other microcrystalline wax, liquid polybutadiene, modified liquid polybutadiene, liquid thiocol, hydrocarbon synthetic lubricant, tall oil, and Sub (Factis) etc. are mentioned. Of these, petroleum-based softening materials are preferred, and process oils, particularly paraffin oil, are particularly preferred.

The compounding quantity of a softening material is 5-150 mass parts with respect to 100 mass parts of copolymers (A), Preferably it is 10-120 mass parts, More preferably, it is 20-100 mass parts.
Specifically, as the reinforcing material, commercially available “Asahi # 50G”, “Asahi # 15G”, “Asahi # 55G”, “Asahi # 50HG”, “Asahi # 60G” (trade name, Asahi Carbon Co., Ltd.) Company-made), "Seast (trade name)" series: TA, S, V, SO, 116, 3, 6, 9, etc. carbon black (manufactured by Tokai Carbon Co., Ltd.), these carbon blacks as silane coupling agents Surface-treated with silica, silica, activated calcium carbonate, fine powder talc, fine powder silicic acid and the like can be used. Of these, carbon black of “Asahi # 55G”, “Asahi # 50HG”, “Asahi # 15G”, “Asahi # 60G” is preferable.

  As the filler, light calcium carbonate, heavy calcium carbonate, talc, clay and the like can be used. Of these, heavy calcium carbonate is preferred. As heavy calcium carbonate, commercially available “Whiteon SB” (trade name, Shiraishi Calcium Co., Ltd.) or the like can be used.

  The compounding amount of the reinforcing material and the filler is usually 30 to 300 parts by mass, preferably 50 to 250 parts by mass, and more preferably 70 to 230 parts by mass with respect to 100 parts by mass of the copolymer (A).

  As processing aids, those generally blended into rubber as processing aids can be widely used. Specific examples include ricinoleic acid, stearic acid, palmitic acid, lauric acid, barium stearate, zinc stearate, calcium stearate or esters. Of these, stearic acid is preferred. The processing aid can be appropriately blended in an amount of 10 parts by mass or less, preferably 8.0 parts by mass or less, more preferably 5.0 parts by mass or less, relative to 100 parts by mass of the copolymer (A). .

  An activator can be suitably selected according to a use, and can be used individually or in mixture of 2 or more types. Specific examples of the activator include di-n-butylamine, dicyclohexylamine, monoelaanolamine, “Acting B” (trade name, manufactured by Yoshitake Pharmaceutical Co., Ltd.), and “Acching SL” (trade name, Yoshitsugu Pharmaceutical Co., Ltd.). Amines such as diethylene glycol, polyethylene glycol (for example, “PEG # 4000” (manufactured by Lion Corporation)), lecithin, triarylate melitrate, zinc compounds of aliphatic and aromatic carboxylic acids (for example, “Struktol activator”). 73 ”,“ Struktol IB 531 ”and“ Struktol FA541 ”(trade name, manufactured by Schill &Seilacher)); zinc peroxide preparations such as“ ZEONET ZP ”(trade name, manufactured by Nippon Zeon Co., Ltd.) ; Octadecyltri Chill ammonium bromide, synthetic hydrotalcite, special quaternary ammonium compounds (for example, "Arquad 2HT-F" (trade name, manufactured by Lion Akzo Co., Ltd.)), and the like. Among these, polyethylene glycol (for example, “PEG # 4000” (manufactured by Lion Corporation)) and “Arcade 2HT-F” are preferable. The compounding quantity of an activator is 0.2-10 mass parts with respect to 100 mass parts of copolymers (A), Preferably it is 0.3-5 mass parts, More preferably, it is 0.5-4 mass parts. .

  The hygroscopic agent can be appropriately selected depending on the application, and can be used alone or in combination of two or more. Specific examples of the hygroscopic agent include calcium oxide, silica gel, sodium sulfate, molecular sieve, zeolite, white carbon and the like. Of these, calcium oxide is preferred. The amount of the hygroscopic agent is 0.5 to 15 parts by mass, preferably 1.0 to 12 parts by mass, and more preferably 1.0 to 10 parts by mass with respect to 100 parts by mass of the copolymer (A). .

  The crosslinked foam of the present invention can be obtained by crosslinking and foaming the composition. As an example of cross-linking foaming, there is a method in which the composition is extruded using an extruder mounted on a sheet-shaped die and formed into a sheet shape. The obtained molded body is introduced into a vulcanizing tank and heated at 100 to 250 ° C. for 5 to 60 minutes, for example, to perform crosslinking and foaming to obtain a sheet-like crosslinked foam (sponge).

  The cross-linked foam of the present invention has a specific gravity of 0.01 to 0.8, preferably 0.03 to 0.6, and more preferably 0.05 to 0.4. When the specific gravity of the cross-linked foam is within the above range, the adhesion to the substrate is enhanced and excellent water-stopping properties are exhibited. In order to adjust the specific gravity of the cross-linked foam within the above range, the type and amount of the foaming agent and the foaming aid and the cross-linking foaming conditions may be appropriately adjusted.

  The crosslinked foam of the present invention can be obtained by crosslinking and foaming the composition. As an example of cross-linking foaming, there is a method in which the composition is extruded using an extruder mounted on a sheet-shaped die and formed into a sheet shape. The obtained molded body is introduced into a vulcanization tank and heated, for example, at 100 to 250 ° C. for 5 to 60 minutes to perform crosslinking and foaming to obtain a sheet-like crosslinked foam (sponge).

The cross-linked foam of the present invention has excellent unevenness followability and high adhesiveness, and therefore has excellent water stopping properties. For this reason, it can be used as a water stop material. The cross-linked foam of the present invention can be suitably used as a lamp cover seal for automobiles that require high water-stopping properties, particularly because of its high adhesion to substrates such as automobile lamp covers.
Moreover, the crosslinked foam of this invention has favorable adhesiveness with respect to a roll, and is excellent in roll processability.

EXAMPLES Hereinafter, although this invention is demonstrated further more concretely based on an Example, this invention is not limited to these Examples. The numerical value regarding the component in the following table | surface shows a mass part.
(Blend material)
The compounding materials used in Examples and Comparative Examples are as follows.
A) Ethylene / α-olefin / non-conjugated polyene copolymer (A)
A-1) EPDM (trade name: Mitsui EPT 8030M (manufactured by Mitsui Chemicals)), structural unit content derived from ethylene: 47% by mass, structural unit content derived from 5-ethylidene-2-norbornene (ENB) Amount: 9.5% by mass, Mooney viscosity [ML _{1 + 4} (100 ° C.)]: 32, tan δ-Tg: -38 ° C., tan δ maximum value: 1.8)
A-2) EPDM (trade name: Mitsui EPT 3045 (manufactured by Mitsui Chemicals)), structural unit content derived from ethylene: 56 mass%, structural unit content derived from 5-ethylidene-2-norbornene (ENB) Amount: 4.7% by mass, tan δ-Tg: −41 ° C., tan δ maximum value: 1.3)
B) Soft material (B)
B-1) 4-Methyl-1-pentene / α-olefin polymer obtained in Polymerization Example 1 below

[Polymerization Example 1]
A SUS autoclave with a stirring blade having a capacity of 1.5 liters sufficiently purged with nitrogen was charged with 300 ml of normal hexane at 23 ° C. (dried in a dry nitrogen atmosphere and activated alumina) and 450 ml of 4-methyl-1-pentene. . The autoclave was charged with 0.75 ml of a 1.0 mmol / ml toluene solution of triisobutylaluminum (TIBAL), and the stirrer was rotated.

  Next, the autoclave was heated to an internal temperature of 60 ° C. and pressurized with propylene so that the total pressure was 0.40 MPa (gauge pressure). Subsequently, 1 mmol of methylaluminoxane prepared in advance, diphenylmethylene (1-ethyl-3-tert-butyl-cyclopentadienyl) (2,7-di-tert-butyl-fluorenyl) zirconium in terms of Al Polymerization was initiated by injecting 0.34 ml of a toluene solution containing 0.01 mmol of dichloride into the autoclave with nitrogen. During the polymerization reaction, the temperature was adjusted so that the internal temperature of the autoclave was 60 ° C. Sixty minutes after the start of polymerization, 5 ml of methanol was injected into the autoclave with nitrogen to stop the polymerization, and the autoclave was depressurized to atmospheric pressure. Acetone was poured into the reaction solution with stirring.

  The obtained powdered polymer containing the solvent was dried at 100 ° C. under reduced pressure for 12 hours. The obtained polymer was 36.9 g, the content of structural units derived from 4-methyl-1-pentene in the polymer was 72 mol%, and the content of structural units derived from propylene was 28 mol%. The weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) was 337,000, tan δ-Tg was 28 ° C., and the maximum tan δ was 2.4.

B-2) Hydrogenated styrene / isoprene / styrene copolymer (trade name: HIBLER 5127 (manufactured by Kuraray Co., Ltd.), tan δ-Tg: 18 ° C., tan δ maximum value: 0.8)
C) Vulcanizing aid Active zinc white (trade name: META-Z102 (manufactured by Inoue Lime Industry Co., Ltd.))
D) Processing aid Stearic acid (trade name: powdered stearic acid cherry (manufactured by NOF Corporation))
E) Active agent Polyethylene glycol (trade name: PEG # 4000 (manufactured by Lion Corporation))
F) Reinforcement material Carbon black (trade name: Asahi # 50G (Asahi Carbon Co., Ltd.))
G) Filler Calcium carbonate (trade name: Whiten SB (manufactured by Shiraishi Calcium Co., Ltd.)
H) Softening material Paraffin oil (trade name: Diana Process Oil PS-430 (manufactured by Idemitsu Kosan Co., Ltd.))
I) Vulcanization accelerator I-1) Thiazole vulcanization accelerator: 2-mercaptobenzothiazole (trade name: Sunseller M (manufactured by Sanshin Chemical Industry Co., Ltd.))
I-2) Dithiocarbamate vulcanization accelerator: zinc dibutyldithiocarbamate (trade name: Sunseller BZ (manufactured by Sanshin Chemical Industry Co., Ltd.))
I-3) Dithiocarbamate vulcanization accelerator: zinc diethyldithiocarbamate (trade name: Sunseller PZ (manufactured by Sanshin Chemical Industry Co., Ltd.))
I-4) Thiourea vulcanization accelerator: N, N′-dibutylthiourea (trade name: Sunseller BUR (manufactured by Sanshin Chemical Industry Co., Ltd.))
J) Vulcanizing agent Sulfur (made by Junsei Chemical Co., Ltd.)
K) Foaming agent Azodicarbonamide (Brand name: VINYHALL AC # LQ (manufactured by Eiwa Chemical Industry Co., Ltd.))
L) Foaming aid urea (trade name: Cell Paste K5 (manufactured by Eiwa Kasei Kogyo Co., Ltd.))
Tan δ-Tg was determined by the following dynamic viscoelasticity measurement.

Using a viscoelasticity measuring apparatus ARES (manufactured by TA Instruments JAPAN Inc.), the temperature dependence of the viscosity of each material was measured under the following measurement conditions. The ratio (G ″ / G ′: loss tangent) between the storage elastic modulus (G ′) and the loss elastic modulus (G ″) obtained by the measurement was defined as tan δ. When tan δ is plotted against temperature, an upwardly convex curve or peak is obtained, and the temperature at the peak apex is defined as the glass transition temperature, that is, tan δ−Tg, and the maximum value at that temperature is measured.
Measurement conditions; Frequency: 1.0 Hz, Temperature: -70 to 80 ° C
Ramp Rate: 4.0 ° C./min, Strain: 0.5%

[Example 1]
MIXTRON BB MIXER (BB-4 type, volume 2.95L, rotor 4WH, manufactured by Kobe Steel, Ltd.) was used to prepare a copolymer (70% filling rate, conventional method (total kneading time 5 minutes)). A-1) 800 g, soft material (B-1) 80 g, vulcanization aid 64 g, processing aid 16 g, activator 8 g, reinforcing material 240 g, filler 1200 g, and softening material 400 g were kneaded.

  Using a 14-inch two-roll kneader, vulcanization accelerator I-1 12 g, vulcanization accelerator I-2 12 g, vulcanization accelerator I-3 12 g, and vulcanization accelerator I-4 12 g Then, 12 g of vulcanizing agent, 280 g of foaming agent and 4 g of foaming aid were added and kneaded.

The obtained kneaded material was subjected to extrusion molding with a rubber extruder having a diameter of 50 mm (manufactured by Mitsuba Corporation) to prepare a sheet-like composition. The temperature condition of the extruder was HD / C2 / C1 / SC = 80/70/60/50 ° C.
This composition was crosslinked and foamed at 180 ° C. for 8 minutes in a hot-air vulcanization tank (manufactured by Microelectronics) to obtain a crosslinked foam.

[Comparative Example 1]
A cross-linked foam was obtained in the same manner as in Example 1 except that the soft material (B-1) was not blended in the kneading by MIXTRON BB MIXER.

[Examples 2 and 3, Comparative Examples 2 and 3]
In kneading with MIXTRON BB MIXER, a crosslinked foam was obtained in the same manner as in Example 1 except that the blending amount of the soft material (B-1) was changed to the amount shown in Table 1.

[Example 4]
In kneading by MIXTRON BB MIXER, a crosslinked foam was obtained in the same manner as in Example 2 except that the soft material (B-2) was blended instead of the soft material (B-1).

[Example 5]
In kneading by MIXTRON BB MIXER, a crosslinked foam was obtained in the same manner as in Example 2 except that the copolymer (A-2) was blended instead of the copolymer (A-1).

[Comparative Example 4]
In kneading with MIXTRON BB MIXER, a crosslinked foam was obtained in the same manner as in Example 5 except that the soft material (B-1) was not blended.

(Measurement method and evaluation method)
The following physical properties of the crosslinked foams obtained in the following examples and comparative examples were measured or evaluated by the following methods. The results are shown in Table 1.
a) Specific gravity The specific gravity of the obtained foam was measured from the difference in mass between air and pure water using an automatic hydrometer (manufactured by Toyo Seiki Seisakusho: M-1 type) in an atmosphere at 23 ° C.
b) Waterstop The obtained sheet-like foam was sliced to a thickness of 10 mm and punched into a ring to produce a ring-shaped sample having an outer diameter of 35 mm, an inner diameter of 25 mm, and a thickness of 10 mm.

  About this ring-shaped sample, the water stop was measured using the water stop measuring apparatus. A water stoppage measuring apparatus will be described with reference to FIG. The water-stop measuring device includes a bottom plate 2, two spacers 3, and a water injection unit 4. The spacer 3 is a long plate-like body having a thickness of 5 mm. The water injection part 4 includes a flat plate part 5 and a cylindrical part 6. The cylindrical portion 6 is made of acrylic having an inner diameter of 30 mm and a thickness of 2 mm, and one end opening thereof is joined to the upper surface of the flat plate portion 5. The flat plate portion 5 is provided with a hole in a portion corresponding to the opening of the cylindrical portion 6.

As shown in FIG. 1, the ring-shaped sample 1 is placed on the bottom plate 2, the spacers 3 are placed on both sides of the ring-shaped sample 1, and the flat plate portion 5 of the water injection unit 4 is applied from above the ring-shaped sample 1. 1 was compressed to the thickness of the spacer 3. The position of the ring-shaped sample 1 was set such that the hole of the flat plate portion 5 covers the opening of the ring-shaped sample 1. The bottom plate 2 and the flat plate portion 5 of the water injection portion 4 were sandwiched by clips (not shown) and fixed. Water was injected into the hollow part of the cylindrical part 6 of the water injection part 4. FIG. 2 shows a state where water is injected. In this state, the hollow part of the ring-shaped sample 1, the hole of the flat plate part 5, and the lower part of the hollow part of the cylindrical part 6 were filled with water 7. The amount of water to be injected was such that the height of the water surface from the upper surface of the flat plate portion 5 was 100 mm. The time from the time when water was injected to the time when water leaked from the ring-shaped sample 1 was measured. From this time, the water-stopping property of the foam was evaluated according to the following criteria.
A: 60 minutes or more B: 30 minutes or more and less than 60 minutes C: 0.5 minutes or more and less than 30 minutes D: Less than 0.5 minutes In addition, the foaming agent and the foaming aid are removed from the compositions in each Example and Comparative Example. A composition having the above composition was prepared, and the following solid hardness was measured using the composition.

c) Solid hardness Measured in accordance with JIS K6253 (2006) “Durometer Hardness Test” test type A described in Section 6 of “Vulcanized Rubber and Thermoplastic Rubber—How to Obtain Hardness”. A sample for solid hardness measurement was prepared by cross-linking at 180 ° C. for 10 minutes using a 100T electric heating press manufactured by Kotaki Co., Ltd., and a sheet thickness of 2 mm.

DESCRIPTION OF SYMBOLS 1 Ring-shaped sample 2 Bottom plate 3 Spacer 4 Water injection part 5 Flat plate part 6 Cylindrical part 7 Water

Claims (7)

An ethylene / α-olefin / non-conjugated polyene copolymer (A) in which a peak of loss tangent tan δ determined by dynamic viscoelasticity measurement is present at −60 ° C. or more and less than 0 ° C .;
A soft material (B) having a peak of loss tangent tan δ determined by dynamic viscoelasticity measurement in a temperature range of 0 ° C. or higher and 60 ° C. or lower;
The specific gravity of the copolymer (A) and the soft material (B) is obtained from a composition containing a mass ratio (copolymer (A) / soft material (B)) of 100/5 to 100/35. 01 to 0.4 cross-linked foam.   The α-olefin in the ethylene / α-olefin / non-conjugated polyene copolymer (A) is an α-olefin having 3 to 20 carbon atoms, and the soft material (B) is 4-methyl-1-pentene / α-. The cross-linked foam according to claim 1, which is an olefin copolymer, and the α-olefin in the copolymer is an α-olefin having 2 to 20 carbon atoms excluding 4-methyl-1-pentene.   In the ethylene / α-olefin / non-conjugated polyene copolymer (A), the content of the structural unit derived from ethylene is 40 to 72 mass%, and the content of the structural unit derived from the non-conjugated polyene is 2 to 2%. The cross-linked foam according to claim 2, which is 15% by mass. The 4-methyl-1-pentene / α-olefin copolymer is
Structural units (i) 61 ~ 85 mol% derived from 4-methyl-1-pentene,
Structural unit (ii) derived from at least one α-olefin selected from α-olefins having 2 to 20 carbon atoms excluding 4-methyl-1-pentene 15 to 39 mol%
And structural unit (iii) derived from non-conjugated polyene 0 to 5 mol%
(However, the total of the structural units (i), (ii) and (iii) is 100 mol%)
The cross-linked foam according to claim 2, comprising a 4-methyl-1-pentene / α-olefin copolymer (b-1) having the following formula.   The cross-linked foam according to claim 4, wherein the α-olefin of the 4-methyl-1-pentene / α-olefin copolymer (b-1) is propylene.   A waterstop material obtained from the crosslinked foam according to any one of claims 1 to 5. The sealing material for motor vehicles obtained from the crosslinked foam in any one of Claims 1-5.

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