JP7139097B2 - Elastomer composition, water-crosslinkable elastomer composition and crosslinked molding - Google Patents

Description

The present invention relates to elastomeric compositions, more particularly, which can be processed like thermoplastics using conventional plastics processing equipment and which have very low compression set like vulcanized rubber. It relates to elastomer compositions.

In recent years, elastomer compositions, which are soft materials having rubber elasticity and have moldability similar to that of thermoplastic resins, have been used as materials to replace vulcanized rubber, such as automobile parts, home appliance parts, electric wire coatings, medical parts, It is widely used in fields such as footwear and miscellaneous goods. Such elastomer compositions have attracted attention as materials that can replace vulcanized rubber, such as dynamically crosslinked thermoplastic elastomers (TVP). A dynamically cross-linked thermoplastic elastomer is a multi-phase polymer material having a sea-island structure in which cross-linked rubber particles are dispersed as domains in a thermoplastic resin matrix. Moreover, it not only has the advantage of being superior to vulcanized rubber in terms of weather resistance and heat resistance, but also has the characteristic of being able to be colored. Since such dynamically crosslinked thermoplastic elastomers can be designed by arbitrarily combining thermoplastic resins and rubbers, various combinations of elastomers have been proposed. For example, at present, various elastomers such as polyolefin, polyurethane, polyester, polystyrene, and polyvinyl chloride have been developed. Olefinic TPVs have received attention.

In recent years, many attempts have been made to apply them to fields where they are used in harsher environments, and in particular, elastomers with extremely low compression set like vulcanized rubber are desired. Although the elastomers described above have a relatively small compression set, they have not reached a sufficiently satisfactory level compared to vulcanized rubber.

In order to solve the above problems, an elastomer with a small compression set is also obtained by applying a silane crosslinking method to the above-described olefinic TPV (for example, Patent Document 1, etc.). Here, the silane cross-linking method means that the silane-grafted rubber obtained by reacting the rubber with a silane coupling agent is brought into contact with water in the presence of a silanol condensation catalyst, whereby the silane-grafted rubber is crosslinked via the silane coupling agent. This is a technique for obtaining a crosslinked rubber with a structure.

JP 2016-166349 A

Various elastomer compositions have been proposed as described above, but an elastomer composition having a compression set equivalent to that of vulcanized rubber has not yet been realized. Accordingly, it is an object of the present invention to provide an elastomeric composition having a compression set comparable to that of vulcanized rubber. Another object of the present invention is to provide a molded article using the elastomer composition and a method for producing the same.

As a result of intensive studies on the above problems, the present inventors have developed an elastomer composition having a compression set equivalent to that of vulcanized rubber by applying a silane crosslinking method to a specific olefin block copolymer. I found what I can do. The present invention is based on such findings.

And the elastomer composition according to the present invention is
(A) an olefin block copolymer;
(B) an organic peroxide;
(C) a silane coupling agent;
An elastomer composition comprising
The (A) olefin block copolymer comprises a crystalline polymer block (hard segment) mainly composed of ethylene, at least one α-olefin selected from α-olefins having 3 to 30 carbon atoms, and ethylene. It is characterized by containing mainly amorphous polymer blocks (soft segments).

In an embodiment of the present invention, the (B) organic peroxide is preferably contained in an amount of 0.1 to 0.5 parts by mass based on 100 parts by mass of the (A) olefin block copolymer.

In an embodiment of the present invention, the silane coupling agent (C) is preferably contained in an amount of 1 to 5 parts by mass with respect to 100 parts by mass of the olefin block copolymer (A).

In an embodiment of the present invention, the melt index of the olefin block copolymer (A) at 190° C. under a load of 2.16 kg according to ASTM D1238 is preferably 0.5 to 15 g/10 minutes.

Also provided in another embodiment of the present invention is a water-crosslinkable elastomeric composition comprising an elastomeric composition and further (D) a silanol condensation catalyst.

In another embodiment of the present invention, there is also provided a crosslinked molded article comprising the above elastomer composition or water-crosslinkable elastomer composition.

In addition, a method for producing a crosslinked molded product according to another embodiment of the present invention comprises:
dynamically heat-treating an elastomer composition comprising (A) an olefin block copolymer, (B) an organic peroxide, and (C) a silane coupling agent;
(D) applying a silanol condensation catalyst to the heat-treated elastomer composition; and (D) treating the elastomer composition to which the silanol condensation catalyst has been applied with warm water to obtain a crosslinked molded article.
includes.

In an embodiment of the present invention, the step of applying (D) the silanol condensation catalyst comprises blending the heat-treated elastomer composition with a solution or masterbatch containing the (D) silanol condensation catalyst, followed by molding. may be done.

In an embodiment of the present invention, the step of applying (D) the silanol condensation catalyst may be performed by applying a solution containing the (D) silanol condensation catalyst to the molded article of the heat-treated elastomer composition. good.

According to the present invention, by applying the silane crosslinking method to a specific olefin block copolymer, an elastomer composition having a compression set equivalent to that of vulcanized rubber can be realized. Therefore, the elastomer composition of the present invention can be suitably used as a material to replace vulcanized rubber for automobile packings, building packings, and the like.

The elastomer composition according to the present invention comprises (A) an olefin block copolymer, (B) an organic peroxide, and (C) a silane coupling agent as essential components. Each component constituting the elastomer composition according to the present invention will be described below.

<(A) Olefin Block Copolymer>
The (A) olefin block copolymer used in the elastomer composition according to the present invention comprises at least a crystalline polymer block (hard segment) mainly composed of ethylene and an α-olefin having 3 to 30 carbon atoms. An olefin block copolymer containing one type of α-olefin and ethylene, and preferably containing an amorphous polymer block (soft segment) in which the proportion of the latter ethylene is less than that of the hard segment, each block It is desirable to have a multi-block structure in which two or more, preferably three or more, are alternately connected. Further, there are a straight-chain structure and a radial structure, but a straight-chain structure is particularly preferable. In the present invention, block copolymers obtained by hydrogenating 80% or more of butadiene copolymers are excluded.

Conventionally, ethylene and α-olefin copolymers synthesized with metallocene catalysts have been random copolymers in which ethylene and α-olefin are randomly copolymerized. On the other hand, the olefin block copolymer used in the present invention is different in that it is a block copolymer as described above. Block copolymers obtained by hydrogenating 80% or more of block copolymers composed of butadiene, for example, DYNARON CEBC manufactured by JSR Corporation, that is, polyethylene whose C part is a hydrogenated product of 1,4-polybutadiene block block (hard segment), and the EB portion includes a random structure block (soft segment) of ethylene and butylene obtained by hydrogenating a compound consisting of a random structure of 1,4-butadiene and 1,2-butadiene. , which is inferior in compression set.

In addition, as the olefin block copolymer in the present invention, commercially available ones can also be used. etc., are commercially available.

The (A) olefin block copolymer used in the present invention can also be synthesized according to the method disclosed in JP-T-2007-529617. For example, a first olefin polymerization catalyst and a second olefin polymerization catalyst capable of preparing, under comparable polymerization conditions, a polymer that has different chemical or physical properties than the polymer prepared by the first olefin polymerization catalyst. and a chain shuttling agent; can be manufactured.

For the addition polymerization described above, a continuous solution polymerization method is preferably applied. Continuous solution polymerization processes are those in which catalyst components, chain shuttling agents, monomers, optionally solvents, auxiliaries, scavengers and polymerization aids are continuously fed to a reaction zone and polymer product is continuously removed therefrom. be Block length can also be varied by controlling the ratio and type of catalyst, the ratio and type of chain shuttling agent, the polymerization temperature, and the like. In addition, in the method for synthesizing the (A) olefin block copolymer, other detailed conditions are disclosed in Japanese Patent Application Laid-Open No. 2007-529617, so the content of the disclosure can be adopted as appropriate.

The α-olefin constituting the soft segment of the (A) olefin block copolymer in the present invention is a linear or branched chain having 3 to 30 carbon atoms, preferably 4 to 20 carbon atoms, more preferably 4 to 8 carbon atoms. α-olefins such as propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-octene , 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicosene and the like. Among these, the case where 1-octene is the main component is preferable from the viewpoint of compatibility and compression set.

From the viewpoint of the effects of the present invention, the hard segment is a crystalline block containing ethylene and 1-octene, and the soft segment has a higher 1-octene content than the hard segment. It is a crystalline block and has a multi-block structure in which two or more, preferably three or more, blocks are alternately connected.

From the viewpoint of the effect of the present invention, the ethylene content is preferably 25-97%, more preferably 40-96%, and even more preferably 55-95%.

(A) The melt index (ASTM D1238, 190°C, 2.16 kg) of the olefin block copolymer is preferably 0.5 to 15 g/10 min, more preferably 0.5 to 10 g/10 min. .

The (A) olefin block copolymer preferably has a density (JIS K6760) of 0.860 to 0.930 g/cm ³ , more preferably 0.865 to 0.890 g/cm ³ .

The (A) olefin block copolymer preferably has a hardness (ASTM D2240, Shore A) of 50-98, more preferably 50-90.

In addition, (A) the olefin block copolymer preferably has a compression set (JIS K6262) of 75 or less at a measurement temperature of 100°C.

In addition, (A) the olefin block copolymer preferably has a melting point measured by DSC of 110 to 125°C, more preferably 115 to 123°C in view of compression set.

Here, the melting point measured by DSC is the peak top melting point obtained by a differential scanning calorimeter (DSC). After that, it was crystallized to −10° C. at a temperature decrease rate of 10° C./min, held at −10° C. for 5 minutes, and then measured up to 200° C. at a temperature increase rate of 10° C./min.

<(B) Organic Peroxide>
The (B) organic peroxide contained in the elastomer composition of the present invention generates radicals when the elastomer composition is melt-kneaded, and the radicals react in a chain reaction to form the (A) olefin The block copolymer crosslinks and serves to achieve good (very low) compression set.

Any radical-generating organic peroxide (B) can be used without particular limitation. Examples include dicumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5 -di-(t-butylperoxy)hexane, 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne-3, 1,3-bis(t-butylperoxyisopropyl)benzene, 1 , 1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, n-butyl-4,4-bis(t-butylperoxy)valerate, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, t-butyl peroxybenzoate, t-butyl peroxy isopropyl carbonate, diacetyl peroxide, lauroyl peroxide, and t-butyl cumyl peroxide, and the like, any one of which alone Alternatively, two or more kinds can be used in combination.

Among the above organic peroxides (B) preferably used in the present invention, 2,5-dimethyl-2,5-dimethyl-2,5-dimethyl-2,5-dimethyl -(t-butylperoxy)hexane and dicumyl peroxide are preferred.

(B) Commercially available organic peroxides include, for example, "Perhexa 25B (trade name)" and "Percumyl D (trade name)" manufactured by NOF Corporation.

(B) The amount of the organic peroxide compounded is usually 0.03 to 1 part by mass, preferably 0.05 to 0.0.8 part by mass, more preferably 0.05 to 0.08 part by mass, per 100 parts by mass of component (A). It is 0.1 to 0.6 parts by mass. When the amount of the organic peroxide (B) is within the above range, the elastomer composition can be sufficiently crosslinked to reduce the compression set, and the generation of pimples (crosslinked gel) can be suppressed. .

<(C) Silane coupling agent>
(C) The silane coupling agent includes hydrolyzable groups (e.g., alkoxy groups such as methoxy and ethoxy groups; acyloxy groups such as acetoxy groups; halogen groups such as chloro groups) and organic functional groups (e.g., amino A silane compound having at least two different reactive groups such as a group, a vinyl group, an epoxy group, a methacryloxy group, an acryloxy group, an isocyanate group, and the like. The silane coupling agent functions to crosslink the (A) olefin block copolymer to achieve good compression set. The silane coupling agent (C) is grafted onto the olefin block copolymer (A) and functions to form a cross-linking point during a post-treatment with warm water, ie, a so-called water cross-linking treatment.

(C) Silane coupling agents include, for example, vinyl silane coupling agents (silane compounds having a vinyl group and a hydrolyzable group), methacrylic silane coupling agents (silane compounds having a methacryloxy group and a hydrolyzable group ), acrylic silane coupling agents (silane compounds having an acryloxy group and a hydrolyzable group), epoxy silane coupling agents (silane compounds having an epoxy group and a hydrolyzable group), amino silane coupling agents (amino and a silane compound having a hydrolyzable group), and a mercapto-based silane coupling agent (a silane compound having a mercapto group and a hydrolyzable group). can be used. Among these, a vinyl-based silane coupling agent is preferable from the viewpoint of heat deformation resistance.

Examples of the vinyl silane coupling agent include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, vinyltriacetoxysilane, vinyl-tris(n-butoxy)silane, vinyl-tris(n -pentoxy)silane, vinyl-tris(n-hexoxy)silane, vinyl-tris(n-heptoxy)silane, vinyl-tris(n-octoxy)silane, vinyl-tris(n-dodecyloxo)silane, vinyl-bis( n-butoxy)methylsilane, vinyl-bis(n-pentoxy)methylsilane, vinyl-bis(n-hexoxy)methylsilane, vinyl-(n-butoxy)dimethylsilane, vinyl-(n-pentoxy)dimethylsilane, and the like. .

(C) The amount of the silane coupling agent is usually 0.5 to 7 parts by mass, preferably 0.8 to 6 parts by mass, with respect to the total 100 parts by mass of the components (A) to (C). It is preferably 1 to 5 parts by mass. When the amount of (C) the silane coupling agent is within the above range, the (A) olefin block copolymer can be sufficiently crosslinked to reduce the compression set.

<Other ingredients>
The elastomer composition according to the present invention may contain optional components in addition to the components described above within a range that does not impair the effects of the invention. For example, a cross-linking aid may be included in order to uniformly and efficiently carry out the cross-linking reaction by (B) the organic peroxide and (C) the silane coupling agent described above. A cross-linking aid is a monomer having two or more polymerizable functional groups in one molecule, and is typically polyfunctional vinyl monomers such as divinylbenzene and triallyl cyanurate; ethylene glycol di(meth) Polyfunctional (meth)acrylates such as acrylates, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and allyl (meth)acrylate and the like, and these can be used singly or in combination of two or more. In this specification, (meth)acrylate means methacrylate or acrylate.

The amount of the cross-linking aid, which is an optional component, is not particularly limited. Parts by weight, preferably 0.05 to 1.5 parts by weight, more preferably 0.1 to 1.0 parts by weight.

The above-mentioned (A) olefin block copolymer can usually be obtained in the form of pellets when a commercially available one is used. On the other hand, (B) the organic peroxide, (C) the silane coupling agent, and the optional cross-linking aid are often liquid at room temperature. Therefore, when producing the elastomer composition according to the present invention, in order to suppress or prevent the separation and non-uniformity of the pellet-like solid component and the liquid component, the liquid component is fed to the melt-kneading device using the liquid addition device. It is normal to put When a liquid addition device is not used, a filler or a lubricant may be added in order to suppress or prevent separation and unevenness between the solid component and the liquid component. By including fillers and lubricants in the elastomer composition, it becomes possible to introduce part or all of the liquid component into the melt-kneading device together with the solid component in the form of pellets.

Such fillers and lubricants are not particularly limited, and known ones can be used. Examples include calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, barium sulfate, talc, mica, clay, etc., and these can be used singly or in combination of two or more.

The blending amount of these fillers and lubricants is an optional component and is not particularly limited, but is usually 0 to 100 parts by mass, preferably 1 to 90 parts by mass, relative to 100 parts by mass of the olefin block copolymer (A). parts, more preferably 5 to 80 parts by mass.

Further, the elastomer composition according to the present invention may optionally contain (A) a thermoplastic resin other than the olefin block copolymer, a softener, a plasticizer, a pigment, an oxidizing Additives such as inhibitors, heat stabilizers, weather stabilizers, mold release agents, antistatic agents, metal deactivators, and surfactants may further be included.

<Water-crosslinkable elastomer composition>
The water-crosslinkable elastomer composition according to the present invention is obtained by applying (D) a silanol condensation catalyst to the elastomer composition of the present invention. (D) The silanol condensation catalyst is obtained by grafting the (C) silane coupling agent to the (A) olefin block copolymer during a post-treatment of the water-crosslinkable elastomer composition with warm water, ie, a so-called water-crosslinking treatment. It promotes and catalyzes the cross-linking of the formed cross-linking points (dehydration condensation reaction between silanols) and improves (reduces) the compression set.

The (D) silanol condensation catalyst used in the present invention is not particularly limited as long as it can promote and catalyze the dehydration condensation reaction between silanols. Oleate, stannous acetate, lead naphthenate, cobalt naphthenate, zinc caprylate, iron 2-ethylhexanoate, titanate, tetrabutyl titanate, tetranonyl titanate, bis(acetylacetonitrile) diisopropyl titanium - Ethylamine complexes, hexylamine complexes, dibutylamine complexes, pyridine complexes, and the like can be mentioned, and these can be used singly or in combination of two or more thereof.

The amount of the silanol condensation catalyst (D) to be applied is not particularly limited, but from the viewpoint of improving the compression set, it is usually 0.005 to 0.3 parts by mass with respect to 100 parts by mass of the elastomer composition. Preferably, it may be 0.008 to 0.2 parts by mass.

As means for applying the (D) silanol condensation catalyst to the elastomer composition, the (D) silanol condensation catalyst is combined with a suitable liquid substance such as a process oil such as paraffin oil, an organic solvent such as ethyl acetate or toluene, or liquid paraffin. It may be blended with the elastomer composition, or a masterbatch containing (D) the silanol condensation catalyst may be prepared and blended with the elastomer composition. Among the above application means, the addition of (D) the silanol condensation catalyst together with the liquid substance to the elastomer composition suppresses gelation and improves the appearance of the extruded molding. As another means of application, an elastomer composition is dynamically heat-treated as described later to obtain a molded article, and (D) a silanol condensation catalyst is applied to the surface of the molded article by a suitable liquid substance such as , organic solvents such as methanol, ethanol, isopropyl alcohol, ethyl acetate and toluene, and process oils such as paraffin oil may be applied.

Any resin used in the masterbatch is not particularly limited, but (A) an olefin block copolymer is preferable from the viewpoint of miscibility with the elastomer composition of the present invention. The masterbatch optionally contains softeners, plasticizers, pigments, fillers, lubricants, antioxidants, heat stabilizers, weather stabilizers, release agents, antistatic agents, metal deactivators, and surfactants. Additives such as agents can also be included. The melt flow rate (160° C., 10 kg) of the masterbatch is preferably 3 g/10 minutes or more, more preferably 25 g/10 minutes or more. Also, the melt flow rate of the masterbatch is preferably higher than the melt flow rate of the elastomer composition.

<Method for producing crosslinked molding>
The molded article of the present invention is formed by dynamically heat-treating the elastomer composition containing the above components (A) to (C) and optional components using any melt-kneader to give an arbitrary shape. can be obtained by The term "dynamically heat-treated" as used herein means melt-kneading under temperature conditions that significantly cause decomposition of the component (B) organic peroxide. Examples of the melt-kneader include single-screw extruders, twin-screw extruders, rolls, mixers, various kneaders, and devices in which these are combined. The temperature conditions for the melt-kneading are usually a temperature higher than the one-minute half-life temperature of the component (B), preferably a temperature higher than the one-minute half-life temperature of the component (B) by 5°C or higher. . The time conditions for the melt-kneading may be usually 30 seconds or longer, preferably 2 minutes or longer.

In order to apply the above-mentioned (D) silanol condensation catalyst to a molded article to obtain a crosslinked molded article, the above-described elastomer composition or water-crosslinkable elastomer composition is used, and an arbitrary molding machine is used to obtain a crosslinked molded article. After molding into an arbitrary shape, a post-treatment with hot water, a so-called water-crosslinking treatment, can be performed to obtain a crosslinked molded product. The temperature conditions for the above water cross-linking treatment may be normal temperature (20°C) to 150°C, preferably 50 to 90°C. The time conditions for the water cross-linking treatment may be generally 10 seconds to 1 week, preferably 1 minute to 3 days. It can also be brought into contact with water under pressure. Further, the water may contain a wetting agent, a surfactant, a water-soluble organic solvent and other additives to improve the wetting of the molding. Water is not limited to liquid water, and may be in a state such as gas (water vapor or moisture in the air). Examples of the molding machine include an extrusion molding machine, an injection molding machine, and a blow molding machine.

The elastomer composition or water-crosslinkable elastomer composition of the present invention has a compression set as small as that of vulcanized rubber, and has flexibility and moldability. It can be molded into a desired shape by an injection molding method, a thermoforming method, an elastic welding method, a compression molding method, or the like. Also, the molding conditions are not particularly limited.

The use of the obtained crosslinked molding is not particularly limited, but it can be suitably used as a substitute for vulcanized rubber. For example, automotive parts include lighting gaskets, 3D exchange blow clean air ducts, fuloteal hinge covers, belly pans (Robotech extrusion gaskets), cup holders, side brake grips, shift knob covers, seat adjustment knobs, IP skins, flapper door seals, wires. Harness grommet, rack and pinion boot, suspension cover boot (strut cover boot), glass guide, inner belt line seal, roof guide, trunk lid seal, molded quarter window gasket, corner molding, glass encapsulation (Robotech Extru John), hood seals, glass encapsulation (injection molding), glass run channels, secondary seals, and the like. In addition, as industrial parts, curtain wall gaskets for high-rise buildings, window frame seals, adhesion to metals/reinforcing fibers, parking deck seals, expansion joints, expansion joints for earthquake countermeasures, residential window door seals (e.g. co-extrusion), Housing door seals, handrail skins, walking mats (sheets, foot rubbers, washing machine drain hoses (two-color molding with PP, etc.), washing machine lid seals, air conditioner motor mounts, drain pipe seals (two-color molding with PP, etc.) ), riser tubes (PVC, etc.), caster wheels, printer rolls, duct hoses, wires & cables, syringe syringe gaskets, etc. In addition, daily necessities and parts include speaker surrounds, hairbrush grips, razor grips, cosmetic grips, Foot, toothbrush grip, daily brush grip, broom tip, kitchen utensil grip, measuring spoon grip, pruning scissors grip, heat-resistant glass lid, gardening grip, scissors grip, stapler grip, computer mouse, golf bag parts, wall It can be preferably used for coating iron grips, chain saw grips, screwdriver grips, hammer grips, electric drill grips, grinder grips, alarm clocks, and the like.

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.

The following materials were prepared.
(1-1) Component (A): Olefin block copolymer INFUSE D9007 (manufactured by Dow Chemical Company, melt index (ASTM D1238, 190°C, 2.16 kg) = 0.5 g/10 minutes)
INFUSE D9107 (manufactured by Dow Chemical Co., melt index (ASTM D1238, 190°C, 2.16 kg) = 1 g/10 minutes)
INFUSE D9507 (manufactured by Dow Chemical Co., melt index (ASTM D1238, 190°C, 2.16 kg) = 5 g/10 minutes)
INFUSE D9817 (manufactured by Dow Chemical Co., melt index (ASTM D1238, 190°C, 2.16 kg) = 15 g/10 minutes)
(1-2) Ethylene/α-olefin copolymer Nodel IP4760P (manufactured by Dow Chemical Company, ethylene/propylene/ethylidene norbornene copolymer rubber: EPDM)
(1-3) Propylene resin PB270A (manufactured by SunAllomer Co., Ltd., crystalline propylene-ethylene block copolymer)
(2) Component B: Organic peroxide Perhexa 25B (manufactured by NOF Corporation, 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane)
(3) Component C: Silane coupling agent KBM-1003 (manufactured by Shin-Etsu Chemical Co., Ltd., vinyltrimethoxysilane )
(4) Component D: Silanol condensation catalyst Neostan U-810 (manufactured by Nitto Kasei Kogyo Co., Ltd., dioctyltin dilaurate)
(5) Other ingredients:
DVB-570 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., divinylbenzene cross-linking aid)
IRGANOX1010 (manufactured by BASF, hindered phenolic antioxidant)
IRGAFOS168 (manufactured by BASF, phosphorus antioxidant)
NS400 (manufactured by Nitto Funka Kogyo Co., Ltd., calcium carbonate)
PW-100 (manufactured by Idemitsu Kosan Co., Ltd., softener for non-aromatic rubber, paraffinic mineral oil)
PEM-8080 (manufactured by Sumika Color Co., Ltd., carbon black masterbatch)

<Production of silanol condensation catalyst masterbatch>
After dry blending using a blender according to the composition shown in Table 1 below, the mixture was supplied to an extruder and melt-kneaded at a die outlet resin temperature of 160° C. to obtain silanol condensation catalyst masterbatches MB1 to MB4. In addition, the numerical value in a table|surface represents a mass part.

<Preparation of Elastomer Composition>
After dry blending each of the above components using a blender according to the composition shown in Tables 2 and 3 below, the elastomer is supplied to the screw root of the extruder and melt-kneaded under the conditions of a die outlet resin temperature of 160 ° C. Compositions 1-18 were obtained. In addition, the numerical value in a table|surface represents a mass part.

<Production of crosslinked molding>
100 parts by mass of each elastomer composition obtained as described above, 5 parts by mass of each masterbatch, and 2 parts by mass of carbon masterbatch (PEM-8080) are combined as shown in Table 4 below for injection molding. A plate-like molding having a thickness of 2 mm, a length of 130 mm, and a width of 130 mm was produced at an injection resin temperature of 200°C. Then, four flat plate-shaped moldings were stacked and press-molded at a temperature of 200°C to produce a flat plate of 6.3 mm in thickness, 160 mm in length, and 130 mm in width, which was then placed in hot water at a temperature of 80°C for 48 hours. By immersion, crosslinked moldings 1 to 18 for compression set and bending set test pieces were obtained.

Similarly, 100 parts by mass of each elastomer composition obtained as described above, 5 parts by mass of each masterbatch, and 2 parts by mass of carbon masterbatch (PEM-8080) were combined as shown in Table 4 below. and supplied to an extruder to produce a flat molded product with a thickness of 2 mm and a width of 2.5 mm under the conditions of an extruded resin temperature of 160 ° C., which is further immersed in hot water at a temperature of 80 ° C. for 48 hours and molded. Crosslinked moldings 1 to 18 for physical appearance evaluation were obtained.

In addition, a silanol condensation catalyst mixture solution was prepared by mixing 100 parts by mass of paraffinic mineral oil (PW-100) and 0.4 parts by mass of a silanol condensation catalyst (Neostan U-810), and 100 parts by mass of elastomer composition 4 was prepared. The silanol condensation catalyst mixed solution is mixed with the elastomer composition 4 at a ratio of 0.5 parts by mass of the silanol condensation catalyst mixed solution per part, and the mixed solution is supplied to an injection molding machine and an extruder, respectively. After obtaining a molded article under the same conditions, the molded article was immersed in hot water at a temperature of 80° C. for 48 hours to obtain a crosslinked molded article 19 for each test piece.

In addition, only elastomer composition 4 was supplied to an injection molding machine and an extruder, respectively, and molded products were obtained under the same conditions as above. A silanol condensation catalyst mixed solution is prepared by mixing parts by mass of the silanol condensation catalyst on the surface of the molded article at a ratio of 0.5 parts by weight of the silanol condensation catalyst mixed solution per 100 parts by weight of the obtained molded article. The catalyst mixed solution was applied and the dried molding was immersed in hot water at a temperature of 80° C. for 48 hours to obtain a crosslinked molding 20 for each test piece.

<Measurement of compression set>
The crosslinked moldings 1 to 20 obtained as described above are subjected to JIS K6262: 2013, a compression rate of 25%, a small test piece, a temperature of 70 ° C., 22 hours, A method (immediate release) and B method. The compression set was measured under the condition of (released after holding at 23° C. for 2 hours). The measurement results were as shown in Tables 5 and 6 below.

<Measurement of bending permanent strain>
In addition, compression permanent under the conditions of A method and B method when bending the crosslinked moldings 1 to 20 under the condition that the test piece is fixed and held in a state where it is bent at 90 degrees using a metal bending jig Strain was measured as above. The measurement results were as shown in Tables 5 and 6 below.

<Appearance evaluation of molding>
The external appearance of the crosslinked moldings 1 to 20 obtained using the extruder as described above was visually evaluated. The evaluation criteria were as follows.
A: The surface was smooth with no foreign matter observed.
◯: Small foreign matter was slightly scattered.
Δ: Small foreign matter was present over the entire surface.
x: The surface was uneven, and the surface was rough with many foreign substances present.
The evaluation results were as shown in Tables 5 and 6 below.

As is clear from the evaluation results in Tables 5 and 6, a crystalline polymer block mainly composed of ethylene, at least one α-olefin selected from α-olefins having 3 to 30 carbon atoms, and ethylene. In the crosslinked moldings (Examples 1 to 16) to which the silane crosslinking method was applied using the olefin block copolymer containing mainly amorphous polymer blocks, the compression set of the vulcanized rubber (A It can be seen that it has a compression set of a value comparable to or smaller than that of about 17% by method.

Further, when comparing Examples 4, 15, and 16, when applying the silanol condensation catalyst to the elastomer composition, the solution containing the silanol condensation catalyst was mixed with the elastomer composition and molded rather than applying it as a masterbatch. It can be seen that the surface appearance of the molded article is better when the solution containing the silanol condensation catalyst is applied to the surface of the molded article after molding the elastomer composition.

On the other hand, a conventional olefin-based TPV (Comparative Example 1) or an olefin block copolymer (Comparative Example 4) was simply molded, and an olefin block copolymer was blended with an organic peroxide and crosslinked. It can be seen that the molded product (Comparative Example 3) does not reach the compression set of vulcanized rubber. In addition, in the crosslinked molded article (Comparative Example 2) obtained by applying the silane crosslinking method to the conventional olefinic TPV, although the compression set by the A method is reduced to some extent, the compression set by the B method is insufficient. .

Claims (12)

(A) an olefin block copolymer;
(B) an organic peroxide;
(C) a silane coupling agent;
An elastomer composition comprising
The (A) olefin block copolymer comprises a crystalline polymer block (hard segment) mainly composed of ethylene, at least one α-olefin selected from α-olefins having 3 to 30 carbon atoms, and ethylene. Including a main amorphous polymer block (soft segment),
The (B) organic peroxide is contained in an amount of 0.285 to 0.475 parts by mass with respect to 100 parts by mass of the (A) olefin block copolymer,
The (C) silane coupling agent is contained in an amount of 2.851 to 4.751 parts by mass with respect to 100 parts by mass of the (A) olefin block copolymer.
An elastomer composition characterized by: (A) an olefin block copolymer;
(B) an organic peroxide;
(C) a silane coupling agent;
An elastomer composition comprising
The (A) olefin block copolymer comprises a crystalline polymer block (hard segment) mainly composed of ethylene, at least one α-olefin selected from α-olefins having 3 to 30 carbon atoms, and ethylene. Including a main amorphous polymer block (soft segment),
The (B) organic peroxide is contained in an amount of 0.285 to 0.475 parts by mass with respect to 100 parts by mass of the (A) olefin block copolymer,
The compression set of the crosslinked molding of the elastomer composition measured by A method in accordance with JIS K6262:2013 is 17% or less.
An elastomer composition characterized by: (A) an olefin block copolymer;
(B) an organic peroxide;
(C) a silane coupling agent;
An elastomer composition comprising
The (A) olefin block copolymer comprises a crystalline polymer block (hard segment) mainly composed of ethylene, at least one α-olefin selected from α-olefins having 3 to 30 carbon atoms, and ethylene. An elastomer composition for packing of automobiles or building materials, comprising mainly amorphous polymer blocks (soft segments). 4. The elastomer composition according to claim 3, wherein the (B) organic peroxide is contained in an amount of 0.1 to 0.5 parts by mass based on 100 parts by mass of the (A) olefin block copolymer. 5. The elastomer composition according to claim 3, wherein the (C) silane coupling agent is contained in an amount of 1 to 5 parts by mass with respect to 100 parts by mass of the (A) olefin block copolymer. 6. The melt index of the olefin block copolymer (A) at 190° C. under a load of 2.16 kg according to ASTM D1238 is 0.5 to 15 g/10 minutes, according to any one of claims 1 to 5. elastomer composition. A water-crosslinkable elastomer composition comprising the elastomer composition according to any one of claims 1 to 6 and (D) a silanol condensation catalyst. (A) an olefin block copolymer;
(B) an organic peroxide;
(C) a silane coupling agent;
(D) a silanol condensation catalyst;
An elastomer composition comprising
The (A) olefin block copolymer comprises a crystalline polymer block (hard segment) mainly composed of ethylene, at least one α-olefin selected from α-olefins having 3 to 30 carbon atoms, and ethylene. an elastomer composition comprising mainly amorphous polymer blocks (soft segments);
(D) a composition comprising a silanol condensation catalyst;
is a combination of
The (D) silanol condensation catalyst is contained in an amount of 0.0021 to 0.020 parts by mass with respect to 100 parts by mass of the olefin block copolymer (A) in the entire combination composition.
A water-crosslinkable elastomer composition. A crosslinked molding of the elastomer composition according to any one of claims 1 to 6 or the water-crosslinkable elastomer composition according to claim 7 or 8. A method for producing the crosslinked molding according to claim 9 ,
dynamically heat-treating an elastomer composition comprising (A) an olefin block copolymer, (B) an organic peroxide, and (C) a silane coupling agent;
(D) applying a silanol condensation catalyst to the heat-treated elastomer composition; and (D) treating the heat-treated elastomer composition to which the silanol condensation catalyst is applied with warm water to obtain a crosslinked molded article.
A method for producing a crosslinked molding, comprising: 11. The step of applying (D) a silanol condensation catalyst according to claim 10, wherein the heat-treated elastomer composition is blended with a solution or masterbatch containing the (D) silanol condensation catalyst and molded. the method of. 11. The method of claim 10, wherein the step of applying (D) a silanol condensation catalyst is performed by applying a solution containing the (D) silanol condensation catalyst to the molded article of the heat-treated elastomeric composition.