JP7333161B2 - Elastomer composition, water-crosslinkable elastomer composition, and method for producing the same - Google Patents

Description

The present invention relates to elastomeric compositions. More particularly, it relates to elastomeric compositions that can be molded and processed like thermoplastics using conventional plastics processing equipment and that have very low compression set like vulcanized rubber.

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. In recent years, many attempts have been made to apply them to fields where they are used in harsher environments, and there is a demand for elastomer compositions with extremely low compression set like vulcanized rubber. Various elastomer compositions have been proposed to address this problem, but they have not reached a sufficiently satisfactory level.

JP-A-2002-322342 Japanese Patent Application Laid-Open No. 2003-183450

The problem of the present invention is that it can be molded like a thermoplastic resin using conventional plastic processing equipment, has a very small compression set like vulcanized rubber, has high oil resistance, and has an appearance. Another object of the present invention is to provide an elastomer composition from which good moldings can be obtained.

As a result of intensive research, the present inventors have found that the above objects can be achieved with a specific elastomer composition.

That is, the present invention
(A) 10 to 80 parts by mass of the first propylene-based resin;
(B) 20 to 90 parts by mass of an ethylene/α-olefin copolymer;
(C) Softener for non-aromatic rubber 60 to 150 parts by mass with respect to 100 parts by mass of (B);
(D) organic peroxide 0.5 to 3 parts by mass with respect to 100 parts by mass of the composition consisting of (A) and (B);
(E) cross-linking aid 0.1 to 6 parts by mass with respect to 100 parts by mass of the composition consisting of (A) and (B);
(F) a silane coupling agent 1 to 7 parts by mass with respect to 100 parts by mass of the composition comprising (A) and (B); and (G) an inorganic filler Composition 100 comprising (A) and (B) 0 to 50 parts by weight per part by weight;
An elastomer composition comprising

The second invention is
(1) the (A) first propylene-based resin, the (B) ethylene/α-olefin-based polymer, the (E) cross-linking aid, the (F) silane coupling agent, and the (G) inorganic Melt-kneading the total amount of the filler and 0 to the total amount of the (C) non-aromatic rubber softener,
(2) adding the whole amount of the organic peroxide (D) to the composition obtained in the step (1) and dynamically heat-treating the composition;
(3) The elastomer composition according to the first invention, which is obtained by blending the residue of (C) added in the step (1) to the composition obtained in the step (2).

A third invention according to the second invention, wherein in the step (3), the residue of (C) added in the step (1) and (I) a second propylene-based resin are blended. is an elastomer composition of

A fourth invention is the elastomer composition according to any one of the first to third inventions, having a surface arithmetic mean roughness Ra of 0.5 to 4.0 μm.

A fifth invention further contains (H) a silanol condensation catalyst in an amount of 0.005 to 0.3 parts by mass with respect to 100 parts by mass of the elastomer composition according to any one of the first to fourth inventions. , which is a water-crosslinkable elastomeric composition.

A sixth invention is a molded article containing the elastomer composition according to any one of the first to fourth inventions or the water-crosslinkable elastomer composition according to the fifth invention.

The seventh invention is
(1) (A) 10 to 80 parts by mass of the first propylene-based resin;
(B) 20 to 90 parts by mass of an ethylene/α-olefin polymer;
(E) cross-linking aid 0.1 to 6 parts by mass with respect to 100 parts by mass of the composition consisting of (A) and (B);
(F) a silane coupling agent 1 to 7 parts by mass per 100 parts by mass of the composition comprising (A) and (B); and (G) an inorganic filler Composition 100 comprising (A) and (B) A total amount of 0 to 50 parts by mass with respect to parts by mass,
0 to the entire amount of 60 to 150 parts by mass relative to 100 parts by mass of the (C) aromatic rubber softener, and
A step of melt-kneading;
(2) 0.2 to 3 parts by mass of the (D) organic peroxide per 100 parts by mass of the composition consisting of (A) and (B) is added to the composition obtained in the step (1). adding and dynamically heat-treating;
(3) a step of blending the composition obtained in step (2) with the residue of (C) added in step (1);
(4) A step of blending 0.005 to 0.3 parts by mass of the silanol condensation catalyst (H) with respect to 100 parts by mass of the elastomer composition obtained in the step (3);
(5) a step of molding the elastomer composition containing the (H) silanol condensation catalyst in step (4) into a molded product; processing;
A method for producing a molded article comprising

According to an eighth invention, in the step (3), the residue of (C) added in the step (1) and (I) the second propylene-based resin are blended. It is a manufacturing method of a molding.

The elastomer composition of the present invention can be molded and processed like a thermoplastic resin using conventional plastic processing equipment, has a very small compression set like vulcanized rubber, and has excellent oil resistance. ing. In addition, by feeding the organic peroxide to the intermediate position of the extruder, even when a large amount of the organic peroxide is added, it is possible to suppress the generation of crosslinked pimples (crosslinked gel). Smooth surface and good appearance. Therefore, it can be suitably used as an alternative material for vulcanized rubber, such as packing for automobiles and packing for building materials.

As used herein, the term "resin" includes resin mixtures containing two or more resins and resin compositions containing components other than resins. The term "greater than or equal to" regarding a numerical range is used to mean a certain numerical value or greater than a certain numerical value. For example, 20% or more means 20% or more than 20%. The term “up to” regarding a numerical range is used to mean a certain numerical value or less than a certain numerical value. For example, 20% or less means 20% or less than 20%. Furthermore, the symbol “~” relating to numerical ranges is used to mean a certain numerical value, greater than a certain numerical value and less than another numerical value, or some other numerical value. Here, another certain numerical value is assumed to be a larger numerical value than the certain numerical value. For example, 10-90% means 10%, greater than 10% and less than 90%, or 90%.

The elastomer composition of the present invention comprises (A) a first propylene resin, (B) an ethylene/α-olefin copolymer, (C) a non-aromatic rubber softener, (D) an organic peroxide, (E) a cross-linking aid, and (F) a silane coupling agent. The elastomer composition of the present invention preferably further contains (G) an inorganic filler. When the elastomer composition of the present invention is post-treated with warm water, ie, a so-called water-crosslinking treatment, it preferably further contains (H) a silanol condensation catalyst. In this specification, an elastomer composition containing the above (H) silanol condensation catalyst is sometimes referred to as a "water-crosslinkable elastomer composition." When the elastomer composition of the present invention is side-fed, it preferably further contains (I) a second propylene-based resin. Each component will be described below.

(A) First propylene-based resin:
Component (A) is a propylene-based resin. The above component (A) contributes to heat resistance and moldability.

The propylene-based resin is a polymer having propylene as the main monomer, and includes propylene homopolymers, random copolymers of propylene and a small amount of other α-olefin comonomers, and block copolymers of propylene and α-olefin comonomers. Polymers can be mentioned.

Examples of the α-olefin comonomer include ethylene, 1-butene, 2-methyl-1-propene, 1-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 1-hexene, 2- ethyl-1-butene, 2,3-dimethyl-1-butene, 2-methyl-1-pentene, 3-methyl-1-pentene, 4-methyl-1-pentene, 3,3-dimethyl-1-butene, 1-heptene, methyl-1-hexene, dimethyl-1-pentene, ethyl-1-pentene, trimethyl-1-butene, methylethyl-1-butene, 1-octene, methyl-1-pentene, ethyl-1-hexene , dimethyl-1-hexene, propyl-1-heptene, methylethyl-1-heptene, trimethyl-1-pentene, propyl-1-pentene, diethyl-1-butene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene. Among these, ethylene, 1-butene, 1-pentene, 1-hexene and 1-octene are preferred, and ethylene, 1-butene and 1-hexene are more preferred. As the α-olefin comonomer, one or a mixture of two or more thereof can be used.

Specific examples of the random copolymer of propylene and a small amount of other α-olefin comonomer include, for example, propylene/ethylene random copolymer, propylene/1-butene random copolymer, and propylene/1-hexene random copolymer. Polymers, propylene/1-octene random copolymers, propylene/ethylene/1-butene random copolymers, propylene/ethylene/1-hexene random copolymers, propylene/ethylene/1-octene random copolymers, etc. can give Among them, propylene/ethylene random copolymer, propylene/1-butene random copolymer, propylene/1-hexene random copolymer, propylene/ethylene/1-butene random copolymer, and propylene/ethylene/ 1-hexene random copolymers are preferred.

The block copolymer of propylene and α-olefin comonomer is a copolymer composed of a crystalline polypropylene component and a copolymer rubber component of propylene and α-olefin comonomer. The crystalline polypropylene component is composed of a propylene homopolymer or a random copolymer of propylene with minor amounts of other α-olefin comonomers.

From the viewpoint of heat resistance, the component (A) is preferably a propylene homopolymer or a block copolymer of propylene and an α-olefin comonomer in which the crystalline polypropylene component is a propylene homopolymer.

One or a mixture of two or more thereof can be used as the component (A).

Using a Diamond DSC type differential scanning calorimeter of PerkinElmer Japan Co., Ltd. for the component (A), held at 230 ° C. for 5 minutes, cooled to -10 ° C. at 10 ° C./min, and held at -10 ° C. for 5 minutes. Then, in the second melting curve (melting curve measured in the last heating process) measured by a program that heats up to 230°C at 10°C/min, the peak top melting point of the peak that appears on the highest temperature side is the heat resistance From the viewpoint of quality, the temperature may be preferably 150° C. or higher, more preferably 160° C. or higher. There is no particular upper limit for the peak top melting point, but since it is a polypropylene-based resin, it will be about 167°C at most.

The melt mass flow rate of component (A) measured under the conditions of 230° C. and 21.18 N according to JIS K 7210:1999 is preferably 0.1 to 0.1 from the viewpoint of moldability and compression set. It may be 1000 g/10 min, more preferably 0.3 to 100 g/10 min.

The amount of component (A) to be blended is usually 10 to 80 parts by mass with respect to 90 to 20 parts by mass of component (B) below, and the total of component (A) and component (B) is 100 parts by mass. be. The amount of component (A) is usually 80 parts by mass or less, preferably 60 parts by mass, per 100 parts by mass of the composition comprising component (A) and component (B) below, from the viewpoint of flexibility and compression set. It is not more than 50 parts by mass, more preferably not more than 50 parts by mass. On the other hand, it is usually 10 parts by mass or more, preferably 15 parts by mass or more, more preferably 20 parts by mass or more, from the viewpoint of suppressing the occurrence of crosslinked pimples and improving mechanical properties, heat resistance, and moldability. The amounts of component (A) and component (B) below can be appropriately set according to the application of the elastomer composition.

Further, as will be described later, in the present invention, when the respective components are melt-kneaded to obtain an elastomer composition, (I) a second polypropylene-based resin may be added to the melt-kneaded composition. . For example, when the components are melt-kneaded using a twin-screw extruder or the like, the (I) second polypropylene-based resin can be compounded by side-feeding from the latter half of the extruder.

As the (I) second polypropylene-based resin to be blended, the same resin as the first polypropylene-based resin as the component (A) described above can be used. The amount of (I) the second polypropylene-based resin to be blended can be appropriately adjusted depending on the intended use of the molded product. The preferred amount of (I) the second polypropylene-based resin is It is preferably 5 to 150 parts by mass, more preferably 10 to 100 parts by mass.

(B) Ethylene/α-olefin copolymer:
The component (B) is a copolymer mainly composed of ethylene and α-olefin. The above component (B) imparts flexibility and contributes to improvement of compression set (reduction of compression set).

Examples of the α-olefin include propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 2-methyl-1-propene and 2-methyl-1-butene. , 3-methyl-1-butene, 2-ethyl-1-butene, 2,3-dimethyl-1-butene, 3-methyl-1-pentene, and 4-methyl-1-pentene. Among these, α-olefins having 3 to 10 carbon atoms are preferred. As the α-olefin, one or a mixture of two or more of these can be used.

In addition to ethylene and α-olefin, the component (B) may contain structural units derived from monomers copolymerizable therewith.

Examples of the copolymerizable monomer include non-conjugated diene monomers. Examples of the non-conjugated diene monomer include 5-ethylidene-2-norbornene (ENB), 1,4-hexadiene, 5-methylene-2-norbornene (MNB), 1,6-octadiene, 5-methyl-1 ,4-hexadiene, 3,7-dimethyl-1,6-octadiene, 1,3-cyclopentadiene, 1,4-cyclohexadiene, tetrahydroindene, methyltetrahydroindene, dicyclopentadiene, 5-isopropylidene-2-norbornene , 5-vinyl-norbornene, dicyclooctadiene, methylenenorbornene, ethylidenenorbornene, norbornadiene, 1,2-butadiene, and 1,4-pentadiene. As the copolymerizable monomer, one or a mixture of two or more thereof can be used.

Specific examples of component (B) include high-density polyethylene, low-density polyethylene, linear low-density polyethylene, ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber, ethylene-propylene 1-butene copolymer rubber, ethylene/1-butene/nonconjugated diene copolymer rubber, ethylene/1-octene copolymer rubber, ethylene/1-octene/nonconjugated diene copolymer rubber, ethylene/propylene/ Examples include 1-butene copolymer rubber, and ethylene/propylene/1-octene copolymer rubber. Among these, ethylene/1-octene copolymer rubber and ethylene/propylene/non-conjugated diene copolymer rubber (EPDM) are preferred from the viewpoint of flexibility. One or a mixture of two or more thereof can be used as the component (B).

The content of structural units derived from ethylene in the component (B) depends on the type and molecular structure of the α-olefin copolymerized with ethylene (linear or long-chain branched, etc.). Depending on the amount, it may be preferably 50 to 90% by mass, more preferably 60 to 85% by mass.

The Mooney viscosity ML ₁₊₄ of component (B) measured at a temperature of 125° C. according to ASTM D-1646 is not particularly limited, but is preferably 10 or more, more preferably 20 or more from the viewpoint of compression set. you can On the other hand, from the viewpoint of moldability, it may be preferably 250 or less, more preferably 150 or less.

The density of component (B) measured according to JIS K 7112:1999 is preferably 850 to 900 Kg/m ³ , more preferably 855 to 890 Kg/m ³ .

As described above, the blending amount of component (B) is appropriately set according to the blending amount of component (A) so that the total amount of component (A) and component (B) is 100 parts by mass. be able to.

(C) Softener for non-aromatic rubber:
Component (C) is a non-aromatic rubber softener. The component (C) functions to improve moldability and flexibility.

The non-aromatic rubber softener is a non-aromatic mineral oil (hydrocarbon compound derived from petroleum or the like) or synthetic oil (synthetic hydrocarbon compound), and is usually liquid, gel or gum at room temperature. shape. Here, the non-aromatic mineral oil means that the mineral oil is not classified as aromatic in the following classification (the number of aromatic carbon atoms is less than 30%). By synthetic oil is meant that no aromatic monomers are used.

Mineral oils used as softeners for rubber are mixtures of any one or more of paraffin chains, naphthenic rings, and aromatic rings, and those having 30 to 45% of naphthenic ring carbon atoms are naphthenic, Those with an aromatic carbon number of 30% or more are called aromatics, and those that do not belong to either naphthenic or aromatic groups and whose paraffin chain carbon number accounts for 50% or more of the total carbon number are called paraffinic. called and distinguished.

Examples of the component (C) include linear saturated hydrocarbons, branched saturated hydrocarbons, and paraffinic mineral oils such as derivatives thereof; naphthenic mineral oils; hydrogenated polyisobutylene, polyisobutylene, and polybutene. synthetic oil; Commercially available examples of the component (C) include NOF CO., LTD. name)” and “Diana Process Oil PW-380 (trade name)”, Idemitsu Petrochemical Co., Ltd.’s synthetic isoparaffinic hydrocarbon “IP-Solvent 2835 (trade name)”, and Sanko Chemical Industry Co., Ltd. n-paraffinic process Oil "Neothiosol (trade name)" and the like can be mentioned. Among these, from the viewpoint of compatibility, paraffinic mineral oils are preferred, and paraffinic mineral oils with a small number of aromatic carbon atoms are more preferred. Moreover, from the viewpoint of handleability, one that is liquid at room temperature is preferable. One or more of these can be used as the component (C).

From the viewpoint of heat resistance and handleability, the component (C) preferably has a dynamic viscosity of 20 to 1000 cSt at 37.8° C. measured according to JIS K 2283:2000. From the viewpoint of handleability, the pour point measured according to JIS K 2269:1987 is preferably -25 to -10°C. Furthermore, from the viewpoint of safety, the flash point (COC) measured according to JIS K 2265:2007 may preferably be 170 to 300°C.

The amount of component (C) to be blended is usually 60 to 150 parts by mass, preferably 70 to 140 parts by mass, more preferably 80 to 130 parts by mass, per 100 parts by mass of component (B). The amount of component (C) to be blended is usually 60 parts by mass or more, preferably 70 parts by mass or more, and more preferably 80 parts by mass or more from the viewpoint of flexibility with respect to 100 parts by mass of component (B). . On the other hand, from the viewpoint of suppressing the occurrence of bleed out, it is usually 150 parts by mass or less, preferably 140 parts by mass or less, more preferably 130 parts by mass or less.

(D) organic peroxide:
Component (D) is an organic peroxide. The component (D) generates radicals during melt-kneading, and the radicals react in a chain reaction to crosslink the component (B), thereby realizing a good (very small) compression set. It also works to improve the oil resistance of the molding. Therefore, in order to improve compression set and oil resistance, it is necessary to increase the blending amount of the organic peroxide. However, if the amount of the organic peroxide compounded is increased, crosslinked pimples occur on the surface of the molded product and the moldability deteriorates. Therefore, it was difficult to obtain a molded product excellent in compression set and oil resistance. In the present invention, as will be described later, components (A) and (B), (E) a cross-linking aid, (F) a silane coupling agent, and optionally (G) an inorganic filler are mixed together. Then, in a state in which each of these components is sufficiently melted and kneaded, the organic peroxide as component (D) is blended. Therefore, it is possible to prevent the components (B) and (D) from undergoing a cross-linking reaction before the respective components are sufficiently melt-kneaded, and as a result, the compression set is very high like that of vulcanized rubber. It is possible to obtain a molded product that is small in size, has high oil resistance, and has a good appearance.

Examples of the component (D) 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 peroxyisopropyl carbonate, diacetyl peroxide, lauroyl peroxide, t-butyl cumyl peroxide, and the like can be mentioned. One or more of these can be used as the component (D).

Among these, the component (D) is 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane from the viewpoint of odor, colorability, and scorch safety of the composition. , and dicumyl peroxide are preferred.

Examples of commercially available products of component (D) include "Perhexa 25B (trade name)" and "Percumyl D (trade name)" manufactured by NOF Corporation.

The amount of the component (D) to be blended is usually 0.5 parts per 100 parts by mass of the total of the components (A) and (B) (in other words, the composition comprising the components (A) and (B)). 5 to 3 parts by mass, preferably 0.6 to 2.5 parts by mass, more preferably 0.7 to 2 parts by mass. The amount of the component (D) is usually 0.5 parts per 100 parts by mass of the components (A) and (B), from the viewpoint of sufficiently cross-linking to reduce the compression set and improve the oil resistance. It is 5 parts by mass or more, preferably 0.6 parts by mass or more, and more preferably 0.7 parts by mass or more. On the other hand, from the viewpoint of suppressing the generation of pimples (crosslinked gel), the amount is usually 3 parts by mass or less, preferably 2.5 parts by mass or less, more preferably 2 parts by mass or less.

(E) cross-linking aid:
The above component (E) is a cross-linking aid. The above component (E) functions to make the cross-linking reaction by the above component (D) uniform and efficient.

The component (E) is a monomer having two or more polymerizable functional groups in one molecule, and typically includes polyfunctional vinyl monomers such as divinylbenzene and triallyl cyanurate; ethylene glycol di( Polyfunctional (meth)acrylates such as meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and allyl (meth)acrylate. ) acrylate monomers; As used herein, (meth)acrylate means methacrylate or acrylate. One or more of these can be used as the component (E).

The amount of component (E) to be blended is usually 0.1 to 6 parts by mass, preferably 0.3 to 5 parts by mass, more preferably 100 parts by mass in total of components (A) and (B). It may be 0.5 to 4 parts by mass. The amount of component (E) to be blended is usually 0.1 parts by mass or more, preferably 0.3 parts by mass or more, more preferably 0.5 parts by mass or more, from the viewpoint of obtaining the effect of using component (E). It's okay. On the other hand, from the viewpoint of controlling the degree of cross-linking within an appropriate range, it may be usually 6 parts by mass or less, preferably 5 parts by mass or less, and more preferably 4 parts by mass or less.

(F) Silane coupling agent:
Component (F) is a silane coupling agent. Silane coupling agents include hydrolyzable groups (e.g., methoxy groups, alkoxy groups such as ethoxy groups; acyloxy groups such as acetoxy groups; halogen groups such as chloro groups, etc.), and organic functional groups (e.g., amino groups, vinyl A silane compound having at least two different reactive groups such as a group, an epoxy group, a methacryloxy group, an acryloxy group, an isocyanate group, etc.). The above component (F) functions to crosslink the above component (B) to achieve good compression set. The above component (F) is grafted onto the above component (B) and functions to form cross-linking points during post-treatment with hot water, ie, so-called water cross-linking treatment.

Examples of the component (F) include 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 agent (silane compound having acryloxy group and hydrolyzable group), epoxy silane coupling agent (silane compound having epoxy group and hydrolyzable group), amino silane coupling agent (amino group 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). One or more of these can be used as the component (F). Among these, vinyl-based silane coupling agents are preferable as the component (F) 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. can be done.

The amount of component (F) blended is usually 1 to 7 parts by mass, preferably 1.5 to 6.5 parts by mass, more preferably 100 parts by mass of components (A) and (B) combined. 2 to 6 parts by mass. The amount of the component (F) is usually 1 part by mass or more, preferably 1 part by mass, based on a total of 100 parts by mass of the components (A) and (B), from the viewpoint of sufficiently cross-linking and reducing the compression set. .5 parts by mass or more, more preferably 2 parts by mass or more. On the other hand, from the viewpoint of the balance (efficiency) between the blending amount and its effect, it may be usually 7 parts by mass or less, preferably 6.5 parts by mass or less, and more preferably 6 parts by mass or less.

(G) Inorganic filler:
The component (G) is an inorganic filler. The above component (G) is an optional component. The above component (A) and the above component (B) are usually commercially available in the form of pellets. The above component (C), the above component (D), the above component (E), and the above component (F) are often liquid at room temperature. Therefore, when producing the elastomer composition of the present invention, the liquid component is introduced into the melt-kneading device using a liquid addition device in order to suppress or prevent the separation and non-uniformity of the pellet-like component and the liquid component. By using component (G), part or all of the liquid component can be fed into the melt-kneading device together with the pellet-like component without using a liquid addition device.

The component (G) is not particularly limited, and any inorganic filler can be used. Examples of the component (G) include calcium carbonate, magnesium carbonate, magnesium oxide, magnesium hydroxide, barium sulfate, talc, mica, and clay. Among these, calcium carbonate, talc, and magnesium hydroxide are preferable from the viewpoint of the effect of suppressing/preventing separation/nonuniformity between the pellet-like component and the liquid component. One or more of these can be used as the component (G).

The amount of the component (G) is not particularly limited because it is an optional component, but usually 0 to 50 parts by mass, preferably 1 to 40 parts by mass, based on 100 parts by mass of the components (A) and (B). parts by weight, more preferably 2 to 30 parts by weight. From the viewpoint of obtaining the effect of using the component (G), the amount of the component (G) to be blended is preferably 1 part by mass or more, more preferably 2 parts by mass or more. On the other hand, from the viewpoint of compression set and mechanical strength, it may be usually 50 parts by mass or less, preferably 40 parts by mass or less, more preferably 30 parts by mass or less.

(H) Silanol condensation catalyst:
Component (H) above is a silanol condensation catalyst. The above-mentioned component (H) is cross-linked at the cross-linking point formed by grafting the above-mentioned component (F) to the above-mentioned component (B) during a post-treatment with warm water, a so-called water cross-linking treatment (dehydration condensation reaction between silanols). promotes and catalyzes, improves (reduces) compression set, and improves oil resistance.

Any silanol condensation catalyst can be used as the component (H) without any particular limitation. Examples of the component (H) include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioleate, stannous acetate, lead naphthenate, cobalt naphthenate, zinc caprylate, iron 2-ethylhexanoate, titanate, Examples include tetrabutyl titanate, tetranonyl titanate, bis(acetylacetonitrile)diisopropyltitanium-ethylamine complex, hexylamine complex, dibutylamine complex, and pyridine complex. One or more of these can be used as the component (H).

The amount of component (H) is not particularly limited because it is an optional component, but it is usually 0.005 to 0.3 parts by mass, preferably 0.008 to 0.008 parts by mass, per 100 parts by mass of the elastomer composition of the present invention. It may be 0.2 parts by mass. From the viewpoint of obtaining the effect of using the component (H), the amount of the component (H) to be blended is usually 0.005 parts by mass or more, preferably 0.008 parts by mass or more. On the other hand, from the viewpoint of the balance (efficiency) between the blending amount and its effect, it may be usually 0.3 parts by mass or less, preferably 0.2 parts by mass or less.

The elastomer composition of the present invention may optionally contain a thermoplastic resin other than the above component (A) and the above component (B), a softening agent other than the above component (C), or Additives such as plasticizers, pigments, organic fillers, lubricants, antioxidants, heat stabilizers, weather stabilizers, mold release agents, antistatic agents, metal deactivators, and surfactants may also be included. can.

Elastomer composition manufacturing method:
The elastomer composition of the present invention contains the total amount of the above components (A), (B), (E), (F), and (G), 0 to the total amount of the above component (C), and optional components used as desired, The entire amount of the component (D) is added to the composition which is melt-kneaded using an arbitrary melt-kneader and the respective components are sufficiently mixed, and the mixture is dynamically heat-treated. , can be obtained by blending the remainder of component (C) into a dynamically heat-treated mixture. Needless to say, when the component (D) is added to the composition to which the entire amount of the component (C) is added, the remaining amount of the component (C) does not have to be added to the dynamically heat-treated mixture. stomach. In the present invention, since the component (D), which is an organic peroxide, is blended as described above, the first propylene-based resin as the component (A) and the ethylene/α-olefin-based resin as the component (B) It is possible to prevent the components (B) and (D) from undergoing a cross-linking reaction before the copolymer and the copolymer are sufficiently melt-kneaded, and as a result, the compression set is very high like that of vulcanized rubber. It is possible to obtain a molded product that is small in size, has high oil resistance, and has a good appearance. In the present invention, for melt-kneading and dynamic heat treatment, for example, a single-screw extruder, a twin-screw extruder, rolls, mixers, various kneaders, and devices combining these can be used as appropriate. . The term "dynamically heat-treated" means that melt-kneading is carried out under temperature conditions that significantly cause decomposition of the component (D) organic peroxide.

The temperature at which the total amount of components (A), (B), (E), (F), and (G), 0 to the total amount of component (C), and optionally used optional components are melt-kneaded Although it can be appropriately adjusted depending on the type of components and the blending amount of each component, it is preferably approximately 170 to 290°C, more preferably 190 to 250°C. By setting the melting temperature within the above range, it is possible to obtain a uniform molten mixture free from unmelted matter while suppressing the denaturation or decomposition of each component due to heat.

In addition, the temperature at which the organic peroxide as component (D) is blended, that is, the temperature at which the dynamic heat treatment is performed is usually a temperature equal to or higher than the one-minute half-life temperature of component (D), preferably the above The temperature may be at least 5° C. higher than the one-minute half-life temperature of component (D). The time conditions for the melt-kneading may be usually 20 seconds or longer, preferably 30 seconds or longer.

The amount of component (C) when mixing and melt-kneading components (A), (B), (E), (F), (G) and (C) is 0 to the entire amount (component ( B) 60 to 150 parts by mass per 100 parts by mass), and is not particularly limited. For example, the entire amount of component (C) may be blended when the respective components are first melt-kneaded, or component (D) may be blended and dynamically blended without blending component (C) during the initial melt-kneading. After heat treatment, the total amount of component (C) may be blended.

Component (D) can be blended by any means by feeding component (D) from the charging zone of the melt-kneading apparatus as described above to any intermediate position of the discharge zone. ), (B), (E), (F), and (G) are sufficiently melted and kneaded, the feeding position may be arbitrary. Further, when component (C) is blended after component (D) is blended, component (C) must be blended at a position closer to the ejection side than the position at which component (D) is blended.

The elastomer composition obtained as described above contains the organic peroxide as component (D) in a proportion of 0.5 to 3 parts by mass per 100 parts by mass of the composition comprising (A) and (B). The appearance is also good in spite of the fact that it is For example, the surface of an elastomer composition (molded article) obtained using an extruder has an arithmetic mean roughness Ra of 0.5 to 4 μm measured according to JIS B 0601:1994. On the other hand, if component (D) is also blended during the melt-kneading of components (A), (B), (E), (F), (G), and (C), the resulting elastomer composition The average roughness Ra becomes 7 μm or more. As described above, in the present invention, it is possible to obtain a molded article having a good appearance while improving the compression set and oil resistance by increasing the amount of the organic peroxide.

Water-Crosslinkable Elastomer Composition The water-crosslinkable elastomer composition of the present invention can be obtained by blending the component (H), ie, a silanol condensation catalyst, with the elastomer composition of the present invention. The component (H) may be blended as a single silanol condensation catalyst as it is, or may be blended as a so-called masterbatch composition in which the silanol condensation catalyst is melt-kneaded with an arbitrary resin. From the viewpoint of handleability, the component (H) is preferably blended as a masterbatch. Any resin used in the masterbatch is not particularly limited, but from the viewpoint of miscibility with the elastomer composition of the present invention, ethylene/α-olefin copolymers, propylene resins, and the like are preferable. The masterbatch may optionally contain a softening agent, a plasticizer, a pigment, an organic filler, a lubricant, an antioxidant, a heat stabilizer, a weather stabilizer, a release agent, and an electrostatic Additives such as inhibitors, metal deactivators, and surfactants can also be included.

The molded article of the present invention is obtained by using the water-crosslinkable elastomer composition of the present invention, using any molding machine, molding it into an arbitrary shape, and then subjecting it to a post-treatment with warm water, a so-called water-crosslinking treatment. be able to. 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.

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

raw materials used

(A) First propylene-based resin:
(A-1) Polypropylene homopolymer "Novatec EA9 (trade name)" from Japan Polypropylene Corporation, melt mass flow rate (temperature 230°C, load 21.18N) 0.5 g/10 min.
(A-2) Polypropylene homopolymer “VS200A (trade name)” manufactured by SunAllomer Co., Ltd. Melt mass flow rate (temperature: 230° C., load: 21.18 N) 0.5 g/10 min.
(A-3) Polypropylene homopolymer “PM900A (trade name)” manufactured by SunAllomer Co., Ltd. Melt mass flow rate (temperature: 230° C., load: 21.18 N) 30 g/10 min.

(B) Ethylene/α-olefin copolymer:
(B-1) Ethylene/α-olefin/diene copolymer “KEP570P (trade name)” manufactured by KUMHO, containing 70% by mass of structural units derived from ethylene. Mooney viscosity ML ₁₊₄ (125° C.) 53, ENB content 4.5 mass %.

(C) Softener for non-aromatic rubber:
(C-1) Paraffinic mineral oil "Diana Process Oil PW100 (trade name)" from Idemitsu Kosan Co., Ltd., dynamic viscosity 100 cSt (40°C), pour point -12°C, flash point 260°C.

(D) organic peroxide:
(D-1) NOF Corporation 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane “Perhexa 25B (trade name)”. 1 minute half-life temperature 179.8°C.
(D-2) NOF Corporation's 2,5-dimethyl-2,5-di-(t-butylperoxy)hexane mixture "Perhexa 25B-36 (trade name)". A mixture obtained by diluting 36% by mass of the above (D-1) with 64% by mass of the above (C-1).

(E) cross-linking aid:
(E-1) Divinylbenzene "DVB-570 (trade name)" of Nippon Steel & Sumikin Chemical Co., Ltd.;

(F) Silane coupling agent:
(F-1) Shin-Etsu Chemical Co., Ltd. vinyltrimethoxysilane "KBM-1003 (trade name)".

(G) Inorganic filler:
(G-1) Calcium carbonate “NS400 (trade name)” manufactured by Nitto Funka Kogyo Co., Ltd.

(H) Silanol condensation catalyst:
(H-1) Nitto Kasei Kogyo Co., Ltd. dioctyltin dilaurate "Neostan U-810 (trade name)".

(I) Second propylene-based resin (I-1) Nippon Polypropylene homopolymer "Novatec EA9 (trade name)", melt mass flow rate (temperature 230°C, load 21.18N) 0.5 g/10 minutes .

(J) Optional ingredients:
(J-1) BASF's hindered phenolic antioxidant "IRGANOX1010 (trade name)".
(J-2) Phosphorus antioxidant "IRGAFOS168 (trade name)" from BASF.
(J-3) Carbon black masterbatch "PEM-8080 (trade name)" manufactured by Sumika Color Co., Ltd.

Example 1A
(1) Production of elastomer composition:
With respect to 100 parts by mass of a composition comprising 21.43 parts by mass of the component (A-1), 9.52 parts by mass of the component (A-3), and 69.05 parts by mass of the component (B-1), the above Component (C-1) 69.05 parts by mass, Component (D-2) 2.79 parts by mass, Component (E-1) 2.00 parts by mass, Component (F-1) 3.00 parts by mass , the component (G-1) 28.57 parts by mass, the component (I-1) 69.05 parts by mass, the component (J-1) 0.24 parts by mass, the component (J-2) 0.12 parts by mass and 4.92 parts by mass of component (J-3), an elastomer composition was produced. Using a co-rotating twin-screw extruder, components other than the above components (D-2), (C-1) and (I-1) are dry blended using a blender, and then the screw root of the extruder , the component (D-2) uses a liquid addition device and is fed at a position about 1/4 of the extruder barrel length, and then the component (C-1) uses the liquid addition device. Use, feed at a position of about 1/2 of the total length of the extruder barrel, then side feed the component (I-1) at a position of about 3/4 of the total length of the extruder barrel, and set the die temperature to 200 ° C. were melt-kneaded under the conditions of to obtain an elastomer composition.

(2) Production of silanol catalyst masterbatch:
100 parts by mass of a composition comprising 14% by mass of the component (A-2), 5% by mass of the component (A-3), 44% by mass of the component (B-1), and 37% by mass of the component (C-1) , the component (D-1) 0.15 parts by mass, the component (E-1) 0.3 parts by mass, the component (H-1) 0.5 parts by mass, the component (J-1) 0.1 parts by mass, 0.05 parts by mass of the component (J-2), 16 parts by mass of the component (G-1), and 2.022 parts by mass of the component (J-3) A silanol catalyst masterbatch It was created. Using a co-rotating twin-screw extruder, components other than the component (C-1) are dry blended using a blender, then fed to the position of the screw root of the extruder, and the component (C-1 ) was side-fed using a liquid addition device at a position about 1/2 of the extruder barrel length, and melt-kneaded at a die temperature of 200° C. to obtain a silanol catalyst masterbatch.

(3) Production of water-crosslinkable elastomer composition:
100 parts by mass of the elastomer composition obtained in the above step (1) and 5 parts by mass of the silanol catalyst masterbatch obtained in the above step (2) (0.01999 parts by mass in terms of the above component (H-1)) were blended using a blender. to obtain a water-crosslinkable elastomer composition.

(4) Manufacture of moldings:
Using the water-crosslinkable elastomer composition obtained in step (3) above, a flat plate 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. using an injection molding machine.
(4-1) Molded product for collecting test pieces for tensile test or oil resistance test:
The flat plate obtained above was immersed in hot water at a temperature of 80° C. for 48 hours to obtain a molding for taking a test piece for a tensile test or an oil resistance test.
(4-2) Molded product for collecting compression set or hardness test piece:
Four flat plates obtained above are stacked and press-molded at a temperature of 200°C to create a flat plate of 6.3 mm in thickness, 160 mm in length and 130 mm in width, which is then immersed in hot water at a temperature of 80°C for 48 hours. Then, a molded article for taking a compression set or hardness test piece was obtained.
(4-3) Molded product for collecting test pieces for appearance evaluation:
A single-screw extruder with a diameter of 20 mm was equipped with a die having a slit of 1 mm thickness x 25 mm width, extruded at a screw rotation speed of 30 rpm and an extrusion temperature of 220 ° C., one side was brought into contact with a metal roll, and the other side was air-cooled to about An extruded sheet having a thickness of 1 mm was produced to obtain a molded article for obtaining a test piece for appearance evaluation.

The following tests (1) to (5) were performed. Table 1 shows the results.
The blending amounts of the components (A) and (B) in the table are values per 100 parts by mass of the composition comprising the components (A) and (B).
Composition P in the table means a composition consisting of the above components (A) and (B).
The amounts of the components (C) to (G) and the components (I) to (J) in the table are based on 100 parts by mass of the composition P (composition consisting of the components (A) and (B)). value.
The amount of component (C) in the table is not only for 100 parts by mass of the composition comprising components (A) and (B), but also for 100 parts by mass of component (B).
When the component (D-2) was used, the equivalent amount of the component (D-1) was also shown. In addition, component (C-1) contained in component (D-2) is not included in the amount of component (C).
Composition Q in the table means an elastomer composition. Composition R in the table means a water-crosslinkable elastomer composition.
MB in the table means silanol catalyst masterbatch. The amount of MB compounded in the table is a value for 100 parts by mass of the elastomer composition. At this time, the calculation is made without including components other than the component (H) in the MB in the elastomer composition.
The value of component (H) in the table is the compounding amount of component (H) per 100 parts by mass of the elastomer composition calculated from the compounding amount of MB. At this time, the "H-1" column was calculated without including the components other than the above component (H) in the MB in the elastomer composition, and the "H-1 conversion" column was calculated including them. be.

(1) Compression set:
In accordance with JIS K6262: 2013, using the molded product obtained in (4-2) above, compressibility 25%, small test piece, temperature 70 ° C. or 120 ° C., 22 hours, and compression set under the conditions of Method A was measured.

(2) Hardness:
Using the molding obtained in (4-2) above, the Shore A hardness (15-second value) was measured according to JIS K6253-3:2012.

(3) Tensile test:
In accordance with JIS K6251:2010, using a dumbbell-shaped No. 3 test piece punched from the molding obtained in (4-1) above, measurement was performed at a tensile speed of 500 mm/min.

(4) Oil resistance test:
According to JIS K6258:2003, using a test piece taken from the molding obtained in (4-1) above, the volume swelling rate was measured after immersing in IRM#903 oil at a temperature of 120° C. for 22 hours.

(5) Appearance Evaluation In accordance with JIS B0601:1994, the arithmetic average roughness Ra of the surface (air-cooled surface) of the molding obtained in (4-3) above was measured. Also, the surface condition (air-cooled surface) was visually evaluated.

Example 1B
With respect to 100 parts by mass of a composition comprising 21.43 parts by mass of the component (A-1), 9.52 parts by mass of the component (A-3), and 69.05 parts by mass of the component (B-1), the above Component (C-1) 69.05 parts by mass, Component (D-2) 2.79 parts by mass, Component (E-1) 2.00 parts by mass, Component (F-1) 3.00 parts by mass , the component (G-1) 28.57 parts by mass, the component (I-1) 69.05 parts by mass, the component (J-1) 0.24 parts by mass, the component (J-2) 0.12 parts by mass and 4.92 parts by mass of component (J-3), an elastomer composition was produced. Using a co-rotating twin screw extruder, 61.90 parts by mass of the above component (C-1) 69.05 parts by mass, components other than (D-2) and (I-1) are blended After dry blending using, feed to the screw root position of the extruder, the above component (D-2) uses a liquid addition device, feeds at a position of about 1/4 of the extruder barrel length, and then , 61.90 parts by mass of the component (C-1) using a liquid addition device, fed at a position of about 1/2 of the total length of the extruder barrel, and then the component (I-1) added to the extruder barrel Side-feeding was carried out at a position of about 3/4 of the total length, and melt-kneading was carried out under conditions of a die set temperature of 200°C to obtain an elastomer composition. Other than that, it was carried out in the same manner as in Example 1A. Table 1 shows the results.

Examples 2-8
Example 1A was repeated except that the components of the elastomer composition were changed as shown in any one of Tables 1-2. The results are shown in any one of Tables 1 and 2.

Example 9
Example 1A was repeated except that the components of the elastomer composition were changed as shown in Table 2 and the above component (I) was not added as a side feed. Table 2 shows the results.

Examples 10-14
(1′) 100 parts by mass of a composition comprising 21.43 parts by mass of the component (A-1), 9.52 parts by mass of the component (A-3), and 69.05 parts by mass of the component (B-1) In contrast, the component (C-1) 69.5 parts by mass, the component (D-2) 2.79 parts by mass, the component (E-1) 2.0 parts by mass, the component (F-1) 3 .0 parts by mass, the component (G-1) 28.57 parts by mass, the component (I-1) 69.05 parts by mass, the component (J-1) 0.24 parts by mass, the component (J-2 ) and 4.92 parts by mass of component (J-3), an elastomer composition was produced. Using a co-rotating twin-screw extruder, components other than the component (C-1), the component (D-2), and the component (I-1) are dry blended using a blender, Feed to the position of the screw root of the extruder, the component (D-1) uses a liquid addition device, feeds at a position of about 1/4 of the extruder barrel length, and then the component (C-1). uses a liquid addition device, feeds at a position of about 1/2 of the extruder barrel length, and then side-feeds the component (I-1) at a position of about 3/4 of the extruder barrel length, An elastomer composition was obtained by melt-kneading under conditions of a die set temperature of 200°C.
(2') Using the elastomer composition obtained in (1') above, a flat plate 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 using an injection molding machine.
(3')
(3'-1) Molded product for collecting test pieces for tensile test or oil resistance test:
The flat plate obtained in (2′) above was immersed in hot water at a temperature of 80° C. for 48 hours to obtain a molding for taking a test piece for a tensile test or an oil resistance test.
(3'-2) Molded product for collecting compression set or hardness test piece:
Four of the flat plates obtained in (2′) above were stacked and press-molded at a temperature of 200°C to form a flat plate with a thickness of 6.3 mm, a length of 160 mm and a width of 130 mm. immersed for 48 hours to obtain a molded product for taking a compression set or hardness test piece.
(3'-3) Molded product for collecting test pieces for appearance evaluation:
A single-screw extruder with a diameter of 20 mm was equipped with a die having a slit of 1 mm thickness x 25 mm width, extruded at a screw rotation speed of 30 rpm and an extrusion temperature of 220 ° C., one side was brought into contact with a metal roll, and the other side was air-cooled to about An extruded sheet having a thickness of 1 mm was produced to obtain a molded article for obtaining a test piece for appearance evaluation.

Tests similar to the above Tests (1) to (5) were conducted. The results are shown in any one of Tables 2-3.

Examples 15-21
The procedure was carried out in the same manner as in Examples 10 to 14, except that the components of the elastomer composition were changed as shown in any one of Tables 3 and 4, and the hot water immersion treatment was not performed. The results are shown in any one of Tables 3-4.

Example 22 (comparative example)
In the same manner as in Example 1A, except that the components of the elastomer composition were changed as shown in Table 4, and the component (D-1) was mainly fed together instead of the side feed of the component (D-2). went. Table 4 shows the results.

Example 23 ( reference example)
As the elastomer composition, an olefinic thermoplastic elastomer composition "Santoprene 101-73 (trade name)" manufactured by ExxonMobil was used to produce moldings, and various tests were conducted. Table 4 shows the results.

Example 24 ( reference example)
The procedure was carried out in the same manner as in Example 23 , except that an olefinic thermoplastic elastomer composition "Santoprene 101-87 (trade name)" manufactured by ExxonMobil was used as the elastomer composition. Table 4 shows the results.

Example 25 (comparative example)
The procedure of Example 2 was repeated except that the amounts of the components (D-2) and (E-1) in Example 2 were changed as shown in Table 4. Table 4 shows the results.

The elastomer composition of the present invention can be molded and processed like thermoplastic resins using conventional plastic processing equipment, has a very low compression set like vulcanized rubber, and has high oil resistance. Moreover, a molded article having a good appearance can be obtained. Therefore, it can be suitably used as an alternative material for vulcanized rubber, such as packing for automobiles and packing for building materials.

Claims (2)

(1) (A) 10 to 80 parts by mass of the first propylene-based resin;
(B) ethylene/α-olefin polymer (excluding (A) above) 20 to 90 parts by mass;
(E) cross-linking aid 0.1 to 6 parts by mass with respect to 100 parts by mass of the composition consisting of (A) and (B);
(F) a silane coupling agent 1 to 7 parts by mass per 100 parts by mass of the composition comprising (A) and (B); and (G) an inorganic filler Composition 100 comprising (A) and (B) A total amount of 0 to 50 parts by mass with respect to parts by mass,
(C) a softening agent for non-aromatic rubber, from 60 to 150 parts by mass with respect to 100 parts by mass of (B), from 0 to the entire amount,
A step of melt-kneading;
(2) 0.5 to 3 parts by mass of the (D) organic peroxide per 100 parts by mass of the composition consisting of (A) and (B) is added to the composition obtained in the step (1). adding and dynamically heat-treating;
(3) a step of blending the residue of (C) added in step (1) to the composition obtained in step (2); and (4) the elastomer composition obtained in step (3). A step of blending 0.005 to 0.3 parts by mass of the (H) silanol condensation catalyst with respect to 100 parts by mass of the product;
A method for producing a water-crosslinkable elastomer composition, comprising: 2. The water-crosslinkable elastomer composition according to claim 1, wherein in the step (3), the residue of (C) added in the step (1) and (I) the second propylene-based resin are blended. Production method.