JP6700865B2 - Hulling roll and method for manufacturing the hulling roll - Google Patents

Description

  The present invention relates to a hulling roll and a method for manufacturing the hulling roll.

  An agricultural thresher equipped with a hulling roll having a rubber layer on the surface of a core material is used for threshing rice and the like (for example, Patent Document 1). Nitrile rubber (NBR), styrene-butadiene rubber (SBR), or the like is used as the rubber (for example, Patent Document 2).

  However, since rubber is easily worn and deteriorated by use, various studies have been made on a rubber layer having superior wear resistance and durability, which can be used for a long period of time, and a hulling roll having the rubber layer ( For example, Non-Patent Document 1 and Patent Document 1).

  Usually, various types of reinforcing materials are appropriately mixed to improve the wear resistance of rubber, and carbon black is considered to have the highest effect of improving the wear resistance. However, considering the use of threshing rice, it is not preferable to use carbon black, which may become a black foreign substance, and the market requires a hulling roll excellent in abrasion resistance even if carbon black is not blended. There is.

  A cured product of a thermoplastic urethane rubber composition is also used as the rubber layer (Patent Document 3). However, the layer formed of the cured product has poor durability and is apt to deteriorate due to hydrolysis by water.

JP 2001-29809 A JP 04-203518 A JP, 2005-202480, A

Abrasion of rubber rolls for chaffing, Journal of Japan Rubber Association, Ichiro Imase, Vol. 44, No. 2 (1971), pp. 187-194.

  As an alternative to the rubber containing carbon black, a rubber containing other fillers, particularly a silica-blended rubber, has been studied because of its relatively high abrasion resistance. However, since silica has poor dispersibility in rubber, the rubber compounded with silica is poor in moldability, and a hulling roll having sufficient abrasion resistance cannot be obtained with the rubber.

  The present invention is intended to solve the problems associated with the prior art as described above, improve the dispersibility of the filler in the rubber, especially silica, excellent in abrasion resistance, further, excellent durability, An object is to provide a hulling roll having a rubber layer on its surface, which can be used for a long period of time.

  The present inventors have conducted intensive studies in order to achieve the above-mentioned object, and as a result, have a very high ethylene content, and blend a high hardness specific ethylene/α-olefin/non-conjugated polyene copolymer with a filler. Can improve the dispersibility of the filler, thereby improving the moldability, it is possible to obtain a rubber layer excellent in wear resistance and durability is suitable, wear resistance and by using the rubber layer on the surface of the hulling roll and The inventors have found that a hulling roll having excellent durability can be used for a long period of time, and have completed the present invention.

The hulling roll of the present invention,
A hulling roll having a rubber layer on the surface,
The rubber layer is
0 to 99 parts by weight of an ethylene/α-olefin/non-conjugated polyene copolymer (A) satisfying the following requirements (A-1) and (A-2):
1 to 100 parts by weight of the ethylene/α-olefin/non-conjugated polyene copolymer (B) satisfying the following requirements (B-1) and (B-2) (however, the copolymer (A) and the copolymer) (The total of (B) is 100 parts by weight),
1 to 100 parts by weight of a filler (C) (excluding carbon black) satisfying the following requirements (C-1) based on 100 parts by weight of the total of the copolymer (A) and the copolymer (B). And a composition containing and.

  (A-1) Containing 40 to 70% by weight of a structural unit derived from ethylene (E).

(A-2) The Mooney viscosity ML ₍₁₊₄₎ (100° C.) at 100° C. obtained by measuring according to ASTM D 1646 is 1 to 50.

  (B-1) Containing more than 70% by weight and 99% by weight or less of a structural unit derived from ethylene (E).

(B-2) The Mooney viscosity ML ₍₁₊₄₎ (100° C.) at 100° C. obtained by measuring according to ASTM D 1646 is ₁ to 90.

  (C-1) The average particle size is 10 μm to 50 μm.

  It is preferable that the composition further contains a crosslinking agent (D).

  The crosslinking agent (D) is a vulcanizing agent, and the vulcanizing agent is 0.1 to 20 parts by weight based on 100 parts by weight of the total amount of the copolymer (A) and the copolymer (B). It is preferable to contain.

  The durometer A hardness of the rubber layer measured according to JIS K6253 is preferably 10 to 100.

The method for manufacturing a hulling roll of the present invention is a method for manufacturing a hulling roll having a rubber layer on its surface,
The manufacturing method is
0 to 99 parts by weight of an ethylene/α-olefin/non-conjugated polyene copolymer (A) satisfying the following requirements (A-1) and (A-2):
1 to 100 parts by weight of the ethylene/α-olefin/non-conjugated polyene copolymer (B) satisfying the following requirements (B-1) and (B-2) (however, the copolymer (A) and the copolymer) (The total of (B) is 100 parts by weight),
1 to 100 parts by weight of a filler (C) (excluding carbon black) satisfying the following requirements (C-1) based on 100 parts by weight of the total of the copolymer (A) and the copolymer (B). And a step of crosslinking the composition containing and in the presence of a crosslinking agent (D) to obtain a rubber layer.

  (A-1) Containing 40 to 70% by weight of a structural unit derived from ethylene (E).

(A-2) The Mooney viscosity ML ₍₁₊₄₎ (100° C.) at 100° C. obtained by measuring according to ASTM D 1646 is 1 to 50.

  (B-1) Containing more than 70% by weight and 99% by weight or less of a structural unit derived from ethylene (E).

(B-2) The Mooney viscosity ML ₍₁₊₄₎ (100° C.) at 100° C. obtained by measuring according to ASTM D 1646 is ₁ to 90.

  (C-1) The average particle size is 10 μm to 50 μm.

  According to the present invention, the ethylene content is very high, and by blending a high hardness ethylene/α-olefin/non-conjugated polyene copolymer with the filler, the dispersibility of the filler can be improved, and the wear resistance and durability are improved. It is possible to provide a hulling roll having a rubber layer on the surface, which is extremely excellent and can be used for a long period of time.

[Hulling roll]
Hereinafter, a hulling roll having a rubber layer on the surface of the present invention and a method for manufacturing the hulling roll will be specifically described.

[Rubber layer]
The hulling roll of the present invention has a rubber layer on the surface of the core material portion. The rubber layer includes a specific ethylene/α-olefin/non-conjugated polyene copolymer (A), a specific ethylene/α-olefin/non-conjugated polyene copolymer (B), and a specific filler (C) ( However, except for carbon black) and a specific amount of each of them. The rubber layer preferably comprises a crosslinked product obtained by crosslinking the composition in the presence of a crosslinking agent (D).

(Ethylene/α-olefin/non-conjugated polyene copolymer (A))
The ethylene/α-olefin/non-conjugated polyene copolymer (A) according to the present invention comprises a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 or more carbon atoms, preferably 3 to 20 carbon atoms. And a constitutional unit derived from a non-conjugated polyene and satisfying the following requirements (A-1) and (A-2). The copolymer (A) preferably satisfies the following requirements (A-1) to (A-3).

  The copolymer (A) may be used alone or in combination of two or more. The copolymer (A) is not limited to structural isomers such as trans isomers and cis isomers as long as the effects of the present invention are exhibited.

  As the α-olefin, specifically, propylene, 1-butene, 4-methylpentene-1,1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1- Dodecene, 1-tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-nonadecene, 1-eicosene, 9-methyldecene-1, 11-methyldodecene-1 and 12-ethyltetradecene-1 etc. Is mentioned. Of these, α-olefins having 3 to 10 carbon atoms are preferable, propylene, 1-butene, 4-methylpentene-1,1-hexene and 1-octene are more preferable, and propylene is particularly preferable.

  These α-olefins may be used alone or in combination of two or more.

  Further, as the non-conjugated polyene, specifically, 1,4-hexadiene, 3-methyl-1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 4 Non-conjugated chain such as 1,5-dimethyl-1,4-hexadiene, 7-methyl-1,6-octadiene, 8-methyl-4-ethylidene-1,7-nonadiene and 4-ethylidene-1,7-undecadiene Diene; methyltetrahydroindene, 5-ethylidene-2-norbornene, 5-methylene-2-norbornene, 5-isopropylidene-2-norbornene, 5-vinylidene-2-norbornene, 6-chloromethyl-5-isopropenyl-2 -Norbornene, 5-vinyl-2-norbornene, 5-isopropenyl-2-norbornene, 5-isobutenyl-2-norbornene, cyclopentadiene, norbornadiene and other cyclic non-conjugated dienes; 2,3-diisopropylidene-5-norbornene , 2-ethylidene-3-isopropylidene-5-norbornene, 2-propenyl-2,2-norbornadiene, triene such as 4-ethylidene-8-methyl-1,7-nonadiene, and the like. Among them, a mixture of 1,4-hexadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene is preferable, and 5-ethylidene-2 A mixture of -norbornene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene is more preferred.

  These non-conjugated polyenes may be used alone or in combination of two or more.

・Requirement (A-1)
The copolymer (A) contains a structural unit derived from ethylene (E) in an amount of usually 40 to 70% by weight, preferably 43 to 65% by weight, more preferably 45 to 55% by weight, and an α-olefin (O The structural unit derived from (1) is usually contained in an amount of 30 to 60% by weight, preferably 35 to 57% by weight, more preferably 45 to 55% by weight (provided that the structural unit derived from ethylene (E) and the α-olefin (O 100% by weight of the structural unit derived from )). The structural unit derived from the non-conjugated polyene (P) is usually 1.0 to 20.0% by weight based on 100% by weight of the structural unit derived from ethylene (E) and the structural unit derived from α-olefin (O). %, preferably 3.0 to 15.0% by weight, more preferably 4.0% to 14.0% by weight. Within the above range, physical properties and production efficiency are preferable.

The composition of the copolymer (A) can be measured, for example, by ¹³ C-NMR according to ASTM D 3900 and ASTM D 6047.

・Requirement (A-2)
The copolymer (A) has a Mooney viscosity ML ₍₁₊₄₎ (100° C.) at 100° C., which is measured according to ASTM D 1646, of usually 1 to 50, more preferably 10 to 50. , And more preferably more than 30 and 50 or less. When the Mooney viscosity is in the above range, good processability is exhibited, which is preferable.

・Requirement (A-3)
The intrinsic viscosity [η] of the copolymer (A) measured in decalin at 135° C. is usually 1.0 to 5.0 dl/g, preferably 1.0 to 4.0 dl/g.

  Specific examples of the copolymer (A) include ethylene/propylene/5-ethylidene-2-norbornene random copolymer and ethylene/propylene/5-ethylidene-2-norbornene-5-vinyl-2-norbornene random copolymer. A polymer etc. can be illustrated.

(Ethylene/α-olefin/non-conjugated polyene copolymer (B))
The ethylene/α-olefin/non-conjugated polyene copolymer (B) according to the present invention comprises a structural unit derived from ethylene and a structural unit derived from an α-olefin having 3 or more carbon atoms, preferably 3 to 20 carbon atoms. And a constitutional unit derived from a non-conjugated polyene and satisfying the following requirements (B-1) and (B-2). The copolymer (B) preferably satisfies the following requirements (B-1) to (B-3).

  The copolymer (B) may be used alone or in combination of two or more. The copolymer (B) is not limited to structural isomers such as trans isomers and cis isomers as long as the effects of the present invention are exhibited.

  Examples of the α-olefin include those exemplified for the copolymer (A). The α-olefins may be used alone or in combination of two or more. Of these, α-olefins having 3 to 10 carbon atoms are preferable, propylene, 1-butene, 4-methylpentene-1,1-hexene and 1-octene are more preferable, and propylene is particularly preferable.

  Examples of the non-conjugated polyene include those exemplified for the copolymer (A). The non-conjugated polyenes may be used alone or in combination of two or more. Among them, a mixture of 1,4-hexadiene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene is preferable, and 5-ethylidene-2 A mixture of -norbornene, 5-vinyl-2-norbornene, 5-ethylidene-2-norbornene and 5-vinyl-2-norbornene is more preferred.

・Requirement (B-1)
The copolymer (B) contains a structural unit derived from ethylene (E) in an amount of usually more than 70% by weight and 99% by weight or less, preferably 70 to 90% by weight, more preferably 70 to 85% by weight. , The structural unit derived from α-olefin (O) is usually contained in an amount of 1% by weight or more and less than 30% by weight, preferably 10 to 30% by weight, and more preferably 15 to 30% by weight (provided that it is derived from ethylene (E)). And the structural unit derived from the α-olefin (O) is 100% by weight). The structural unit derived from the non-conjugated polyene (P) is usually 1.0 to 20.0 wt% relative to the structural unit derived from ethylene (E) and the structural unit derived from α-olefin (O) of 100 wt %. %, preferably 3.0 to 15.0% by weight, more preferably 4.0 to 14.0% by weight. Within the above range, physical properties and production efficiency are preferable.

The composition of the copolymer (B) can be measured, for example, by ¹³ C-NMR according to ASTM D 3900 and ASTM D 6047.

・Requirement (B-2)
The copolymer (B) has a Mooney viscosity ML ₍₁₊₄₎ (100° C.) at 100° C., obtained by measuring according to ASTM D 1646, of usually 1 to 90, more preferably 1 to 60. , And more preferably in the range of 1-30. When the Mooney viscosity is within the above range, good processability and good physical properties are exhibited, which is preferable.

・Requirement (B-3)
The intrinsic viscosity [η] of the copolymer (B) measured in decalin at 135° C. is usually 1.0 to 5.0 dl/g, preferably 1.0 to 4.0 dl/g.

  Specific examples of the copolymer (B) include ethylene/propylene/5-ethylidene-2-norbornene random copolymer and ethylene/propylene/5-ethylidene-2-norbornene-5-vinyl-2-norbornene random copolymer. A polymer etc. can be illustrated.

(Method for producing copolymer (A) and copolymer (B))
The copolymer (A) and the copolymer (B) can be produced using a known polymerization catalyst such as a Ziegler-Natta catalyst or a metallocene catalyst. The polymerization method is also not particularly limited, and liquid polymerization method such as solution polymerization, suspension polymerization, bulk polymerization method, gas phase polymerization method, and other known polymerization methods can be used. Further, these copolymers are not limited as long as the effects of the present invention are exhibited, and are available as commercial products. Examples of commercially available products include Vistalon (registered trademark) manufactured by ExxonMobil Corporation, Esplen (registered trademark) manufactured by Sumitomo Chemical Co., Ltd., and Mitsui EPT (registered trademark) manufactured by Mitsui Chemicals, Inc.

(Filler (C))
The filler (C), which is one of the components included in the composition according to the present invention, differs from carbon black such as SRF, GPF, FEF, MAF, HAF, ISAF, SAF, FT and MT in the following requirements (C- As long as the condition 1) is satisfied, the one generally used as a reinforcing material for synthetic rubber can be used. The filler (C) preferably satisfies the following requirements (C-1) to (C-2).

・Requirement (C-1)
The average particle size of the filler is usually 10 to 50 μm, and preferably 20 to 40 μm for the reason of the balance between dispersibility and physical properties. In the present invention, the average particle diameter means a 50%-equivalent particle diameter d50 obtained from an integrated distribution curve measured by using a laser diffraction type particle size distribution measuring apparatus (particle size distribution measuring apparatus based on a laser diffraction/scattering method). ..

  As the filler (C), silica, activated calcium carbonate, light calcium carbonate, heavy calcium carbonate, fine powder talc, fine powder silicic acid, talc, clay, calcium silicate, kaolin, talc, diatomaceous earth, mica powder, asbestos, Alumina, barium sulfate, aluminum sulfate, calcium sulfate, basic magnesium carbonate, molybdenum disulfide, graphite, glass fiber, glass ball, silas balloon, basic magnesium sulfate whiskers, calcium titanate whiskers, aluminum borate whiskers, and the like. Those obtained by treating the surface of the inorganic substance with a silane coupling agent or the like can be used. Considering the application of threshing rice, it is not preferable to use a filler having a black color or a color such as carbon black, and a filler having a white color tone such as silica, activated calcium carbonate, light calcium carbonate or heavy calcium carbonate is not preferable. preferable. Among these, silica is more preferable because excellent dispersibility can be obtained and abrasion resistance of carbon black and the degree of identification can be obtained.

・Requirement (C-2)
The specific surface area of the filler (C) is not particularly limited as long as the effects of the present invention are exhibited, but it is usually preferably ^{5 to} 120 m ² /g. In the present invention, silica can be preferably used because of the effect of improving rigidity.

〔Composition〕
The composition according to the present invention contains 0 to 99 parts by weight of the copolymer (A), preferably 0 to 90 parts by weight, more preferably 0 to 60 parts by weight, and even more preferably 0 for the reason of processability. ˜50 parts by weight and the copolymer (B) is usually 1 to 100 parts by weight, preferably 10 to 100 parts by weight, more preferably 40 to 100 parts by weight, still more preferably higher hardness and more than filler. From the reason that good dispersibility can be obtained, the content is 50 to 100 parts by weight (however, the total amount of the copolymer (A) and the copolymer (B) is 100 parts by weight). Further, the composition contains the filler (C) in an amount of usually 1 to 100 parts by weight, preferably 30 to 100 parts by weight, based on 100 parts by weight of the total amount of the copolymer (A) and the copolymer (B). Parts, and more preferably 40 to 100 parts by weight for the reason that high hardness is achieved.

  The composition according to the present invention has a very high ethylene content and a high hardness with respect to the specific copolymer (B), preferably with respect to the copolymer (B) and the copolymer (A). Since the filler (C) is contained in the above range, the dispersibility of the farr (C) in the composition is remarkably improved, and the moldability is also improved. Therefore, the rubber layer made of the composition has not only high hardness but also excellent wear resistance and durability due to the good dispersion of the filler (C). By using the rubber layer on the surface of the hulling roll, it is possible to obtain a hulling roll which has excellent wear resistance and durability and can be used for a long period of time. According to the present invention, an agricultural thresher provided with the hulling roll can be suitably obtained.

  The reason for this is not clear, but normally, when a filler (C) such as silica is blended, the hardness of the rubber layer becomes high at room temperature, but the ethylene content is very high, and the specific copolymer (B) having a high hardness is added. It is considered that by blending with the filler (C), the viscosity at the time of kneading can be lowered, and the dispersibility of the filler (C), particularly silica can be improved. Therefore, it is considered that a rubber layer having particularly improved abrasion resistance and excellent durability can be obtained.

  A composition containing less than 1 part by weight of the copolymer (B) may not have sufficient abrasion resistance.

  It is preferable to add a copolymer (A) having a medium ethylene content because it is excellent in processability.

  If the composition of the filler (C) is less than 1 part by weight, the desired effect cannot be obtained, and the rubber layer obtained by vulcanization may have poor rigidity and mechanical strength. A composition containing more than 100 parts by weight of the filler (C) has poor kneading processability, and the rubber elasticity and mechanical strength of the rubber layer obtained by vulcanization may decrease.

(Crosslinking agent (D))
The composition according to the present invention may contain a crosslinking agent (D) in addition to the copolymer (A), the copolymer (B) and the filler (C). Examples of the cross-linking agent used for cross-linking include vulcanizing agents such as sulfur and sulfur compounds, and organic peroxides. The crosslinking agent is not particularly limited as long as the effects of the present invention are exhibited, but is preferably 0.1 to 20 parts by weight with respect to 100 parts by weight of the total amount of the copolymer (A) and the copolymer (B). And more preferably 0.3 to 5 parts by weight.

  In the present invention, a vulcanizing agent is preferable because it has less odor than organic peroxides and thus has excellent workability and can be processed well.

-Vulcanizing agent As one of the crosslinking agents, vulcanizing agents used during vulcanization include sulfur and sulfur compounds. Specific examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, insoluble sulfur and the like.

  Specific examples of the sulfur compound include sulfur chloride, sulfur dichloride, and polymer polysulfide. Further, it is also possible to use a sulfur compound which releases active sulfur at the vulcanization temperature and vulcanizes, for example, morpholine disulfide, alkylphenol disulfide, tetramethylthiuram disulfide, dipentamethylenethiuram tetrasulfide, selenium dimethyldithiocarbamate. You can Of these, sulfur is preferably used. These sulfur and sulfur compounds may be used alone or in combination of two or more.

  Sulfur and sulfur compounds are not particularly limited as long as the effects of the present invention are exhibited, but usually 0.1 to 20 parts by weight based on 100 parts by weight of the total of the copolymer (A) and the copolymer (B). The amount is preferably 0.1 to 10 parts by weight, more preferably 0.3 to 5 parts by weight, but it is desirable to appropriately determine the optimum amount according to the required physical properties. When sulfur or a sulfur compound is used as a vulcanizing agent, it is preferable to use a vulcanization accelerator together.

・Vulcanization accelerator As the vulcanization accelerator, specifically, N-cyclohexyl-2-benzothiazole sulfenamide, N-oxydiethylene-2-benzothiazolsulfenamide, N,N-diisopropyl-2- Sulfenamide compounds such as benzothiazolsulfenamide; 2-mercaptobenzothiazole, 2-(2',4'-dinitrophenyl)mercaptobenzothiazole, 2-(4'-morpholinodithio)benzothiazole, di-2 -Thiazole compounds such as dibenzothiazyl disulfide (MBTS); guanidine compounds such as diphenylguanidine, diorthotolylguanidine, diorsonitrile guanidine, orthonitrile biguanide, diphenylguanidine phthalate; acetaldehyde-aniline reaction product, butyraldehyde- Aniline condensates, aldehyde amines such as hexamethylenetetramine, acetaldehyde ammonia, or aldehyde-ammonia compounds; imidazoline compounds such as 2-mercaptoimidazoline; thiocarbanilide, diethylthiourea, dibutylthiourea, trimethylthiourea, diorthotriylthiourea Thiourea-based compounds such as; tetramethylthiuram monosulfide, tetramethylthiuram disulfide, tetraethylthiuram disulfide, tetrabutylthiuram disulfide, pentamethylenethiuram tetrasulfide, and other thiuram-based compounds; zinc dimethyldithiocarbamate, zinc diethyldithiocarbamate, di-n -Dithioate compounds such as zinc butyldithiocarbamate (ZnBDC), zinc ethylphenyldithiocarbamate, zinc butylphenyldithiocarbamate, sodium dimethyldithiocarbamate, selenium dimethyldithiocarbamate and tellurium dimethyldithiocarbamate; xanthates such as zinc dibutylxanthate. Examples of compounds include compounds such as zinc white (zinc oxide).

  These vulcanization accelerators are not particularly limited as long as the effects of the present invention are exhibited, but are usually 0.1 to 20 relative to 100 parts by weight in total of the copolymer (A) and the copolymer (B). It is used in a proportion of parts by weight, preferably 0.2 to 10 parts by weight, but it is desirable to appropriately determine the optimum amount according to the required physical properties.

-Organic peroxide As the organic peroxide which is one of the cross-linking agents, any one that is usually used for peroxide vulcanization of rubber may be used. Specifically, dicumyl peroxide, di-t-butyl peroxide, di-t-butylperoxy-3,3,5-trimethylcyclohexane, t-butylhydroperoxide, t-butylcumyl peroxide, benzoyl Peroxide, 2,5-dimethyl-2,5-di(t-butylperoxine) hexyne-3,2,5-dimethyl-2,5-di(benzoylperoxy)hexane, 2,5-dimethyl-2 Examples include 1,5-mono(t-butylperoxy)-hexane, α,α′-bis(t-butylperoxy-m-isopropyl)benzene and the like. Among them, dicumyl peroxide, di-t-butyl peroxide and di-t-butylperoxy-3,3,5-trimethylcyclohexane are preferably used. These organic peroxides are used alone or in combination of two or more.

  The organic peroxide is not particularly limited as long as the effects of the present invention are exhibited, but is usually 0.0003 to 0.05 based on 100 parts by weight of the total amount of the copolymer (A) and the copolymer (B). It is used in a molar ratio, preferably 0.001 to 0.03 mol, but it is desirable to appropriately determine the optimum amount according to the required physical properties.

  When using an organic peroxide as a crosslinking agent, it is preferable to use a crosslinking auxiliary together. Specific examples of the crosslinking aid include sulfur; quinone dioxime compounds such as p-quinone dioxime; methacrylate compounds such as polyethylene glycol dimethacrylate; allyl compounds such as diallyl phthalate and triallyl cyanurate; and others. Maleimide compounds, such as divinylbenzene. Such a crosslinking aid is used in an amount of 0.5 to 2 mol, preferably approximately equimolar, relative to 1 mol of the organic peroxide used.

(Other ingredients)
The composition according to the present invention has various known additives generally used in the production of rubber products, such as a softening agent, an antioxidant, a processing aid, an alkoxysilane compound, and an activator, depending on performance. , Reaction inhibitors, colorants, dispersants, flame retardants, plasticizers, antioxidants, scorch inhibitors, UV absorbers, antistatic agents, lubricants, antifungal agents, mastication accelerators, tackifiers, surface active agents You may select an agent etc. suitably and mix it in a suitable compounding quantity.

-Softening agent As the softening agent, a softening agent usually used for rubber can be used.

  Specifically, petroleum-based softeners such as process oil, lubricating oil, paraffin, liquid paraffin, petroleum asphalt, and vaseline; coal tar-based softeners such as coal tar and coal tar pitch; castor oil, linseed oil, rapeseed oil, Fat oil softeners such as coconut oil; tall oil; sub; waxes such as beeswax, carnauba wax and lanolin; fatty acids and fatty acid salts such as ricinoleic acid, palmitic acid, barium stearate, calcium stearate and zinc laurate; petroleum Examples thereof include resins, atactic polypropylene, coumarone indene resin, and other synthetic polymer substances. Of these, petroleum-based softeners are preferably used, and process oils are particularly preferably used.

  The blending amount of these softening agents is not particularly limited as long as the effects of the present invention are exhibited, but 150 parts by weight or less based on 100 parts by weight of the total of the copolymer (A) and the copolymer (B), The maximum amount is preferably 130 parts by weight or less.

-Anti-aging agent If an anti-aging agent is used, the material life can be further extended. This is the same as in the case of normal rubber.

  Specific examples of the antioxidant used in the present invention include phenylnaphthylamine, 4,4′-(α,α-dimethylbenzyl)diphenylamine, N,N′-di-2-naphthyl-p-phenylenediamine and the like. Aromatic secondary amine stabilizers of 2,6-di-t-butyl-4-methylphenol, tetrakis-[methylene-3-(3',5'-di-t-butyl-4'-hydroxyphenyl] ) Phenolic stabilizers such as propionate]methane; Thioether stabilizers such as bis[2-methyl-4-(3-n-alkylthiopropionyloxy)-5-t-butylphenyl]sulfide; 2-mercaptobenzimidazole etc. Examples thereof include benzimidazole-based stabilizers; dithiocarbamate-based stabilizers such as nickel dibutyldithiocarbamate; and quinoline-based stabilizers such as polymers of 2,2,4-trimethyl-1,2-dihydroquinoline. These antioxidants may be used alone or in combination of two or more.

  Such an anti-aging agent is not particularly limited as long as the effects of the present invention are exhibited, but usually 5 parts by weight or less based on 100 parts by weight of the total of the copolymer (A) and the copolymer (B), It is preferably used in a proportion of 3 parts by weight or less, but it is desirable to appropriately determine the optimum amount according to the required physical property values.

-Processing aid As a processing aid, a compound used in usual rubber processing can be used. Specifically, higher fatty acids such as ricinoleic acid, stearic acid, palmitic acid, and lauric acid, higher fatty acid salts such as barium stearate, zinc stearate, and calcium stearate, ricinoleic acid ester, stearic acid ester, palmitic acid ester, and lauric acid. Examples include higher fatty acid esters such as acid esters.

  Such a processing aid is not particularly limited as long as the effects of the present invention are exhibited, but usually 10 parts by weight or less based on 100 parts by weight of the total amount of the copolymer (A) and the copolymer (B), It is preferably used in a proportion of 5 parts by weight or less, but it is desirable to appropriately determine the optimum amount according to the required physical property values.

-Surfactant As the surfactant, compounds used in ordinary rubber processing can be used. Specifically, amines such as di-n-butylamine, dicyclohexylamine, monoeranolamine, triethanolamine, "Acting B (manufactured by Yoshitomi Pharmaceutical Co., Ltd.), "Acting SL (manufactured by Yoshitomi Pharmaceutical Co., Ltd.), polyethylene glycol. , Zinc compounds of diethylene glycol, polyethylene glycol, lecithin, triallyl mellitate, aliphatic and aromatic carboxylic acids (eg, "Struktol activator 73", "Struktol IB 531", "Struktol FA 541" manufactured by Schill & SeiraZEET, Inc.). (Nippon Zeon Co., Ltd.), octadecyltrimethylammonium bromide, synthetic hydrotalcite, special quaternary ammonium compounds (eg; “Arcard 2HF” (Lion Akzo Co., Ltd.)).

  Such a surfactant is not particularly limited as long as the effects of the present invention are exhibited, but is usually 0.2 to 10 relative to 100 parts by weight of the total amount of the copolymer (A) and the copolymer (B). The amount is about 0.3 to 5 parts by mass, more preferably about 0.5 to 4 parts by mass. The surfactant can be appropriately selected depending on the application, and can be used alone or in combination of two or more.

[Method for producing composition]
The composition according to the present invention comprises the copolymer (A), the copolymer (B) and the filler (C), and optionally a cross-linking agent (D) together with, for example, a general rubber product such as a softening agent. Can be prepared by a general method for producing a rubber compound from various known additives used in the production of

  As a method for producing the composition, the copolymer (A), the copolymer (B) and the filler (C) can be prepared, for example, by using an internal mixer (closed mixer) such as a Banbury mixer, a kneader or an intermix. ), and if necessary, a softening agent (for oil extension), a processing aid, a vulcanization accelerator and the like are kneaded at a temperature of 80 to 170° C. for 2 to 20 minutes. Then, if necessary, additives such as a cross-linking agent (D) and a softening agent are added to the obtained blended product by using rolls such as an open roll or a kneader, and a vulcanization accelerator is added if necessary. Can be prepared by additionally mixing a crosslinking aid, kneading at a roll temperature of 40 to 80° C. for 5 to 30 minutes, and then dispensing.

  Therefore, the composition according to the present invention (unvulcanized compounded rubber) is prepared, for example, by the following method. Using an internal mixer such as a Banbury mixer, a kneader or an intermix, the copolymer (A), the copolymer (B) and the filler (C), if necessary, a softening agent, a processing aid, and an additive. After kneading an additive such as a sulfur accelerator at a temperature of 110 to 170° C. for 3 to 10 minutes, a roll such as an open roll or a kneader is used, and if necessary, a crosslinking agent (D) and a softening agent. It can be prepared by additionally mixing an agent, a vulcanization accelerator or a vulcanization aid at a temperature of less than 120° C., kneading at a roll temperature of 40 to 80° C. for 5 to 30 minutes, and then dispensing.

  When the kneading temperature in the internal mixers is low, the copolymer (A), the copolymer (B) and the filler (C) together with the softening agent, and the crosslinking agent (D ), a vulcanization accelerator, a vulcanization aid, etc. can also be kneaded simultaneously.

[Rubber layer]
The rubber layer according to the present invention comprises the composition. Further, the rubber layer preferably comprises a crosslinked product obtained by crosslinking the composition in the presence of a crosslinking agent (D). Particularly, when the rubber layer is made of a vulcanized product, ionic aggregates are formed in the rubber layer, so that the rubber layer has high rigidity and excellent mechanical properties (elongation) and rubber elasticity. Also has. Therefore, the rubber layer can be thinned to have desired physical properties (in particular, abrasion resistance and durability), which is particularly preferable.

  The rubber layer is not particularly limited as long as the effects of the present invention are exhibited, but the durometer A hardness measured according to JIS K6253 is preferably 10 to 100. If the durometer A hardness is less than 10, the rubber layer is too soft, and the abrasion resistance may decrease. Further, if the durometer A hardness exceeds 100, the rice may be damaged during hulling and the occurrence rate of so-called broken rice may increase.

  The durometer A hardness is more preferably from 40 to 100, further preferably from 60 to 100 from the viewpoint of the balance between the rice breakage rate and the wearability.

  The durometer A hardness of the rubber layer is preferably about 40 to 90 when the rice to be hulled is relatively soft Japonica rice or the like, and the durometer A hardness when the rice to be hulled is relatively hard Indica rice or the like. About 60 to 100 is preferable.

  The “rubber layer” in the present invention corresponds to the “rubber part” according to JIS K 9124.

  The rubber layer preferably has a tan δ peak temperature (Tg) of 10° C. or lower. This is because appropriate rubber elasticity is exhibited at 30 to 50° C., which is the temperature of the rubber layer during use.

  The rubber layer preferably has a DIN wear amount of 10 to 500 mg. If the DIN abrasion amount is less than 10 mg, the occurrence rate of broken rice may increase during hulling, and if it exceeds 500 mg, the durability becomes insufficient. The DIN wear amount can be measured according to the DIN wear test of JIS-K6264-2:2005.

  The thickness of the rubber layer is not particularly limited as long as the effects of the present invention are exhibited, and can be appropriately set in accordance with the specifications of the huller to which the hulling roll is attached and the JIS standard (JIS B 9214) as in the conventional product. Here, the thickness of the rubber layer means a value of 1/2 of the difference between the outer diameter and the inner diameter of the rubber layer when not in use.

[Rubber layer manufacturing method]
The rubber layer is formed by injection-molding the above-mentioned rubber composition into a mold in which the core material of the rice roll is set in advance and then crosslinking the composition.

  In addition, the rubber layer is prepared by once preparing an uncrosslinked composition (compounded rubber) by the method as described above, and then molding this compounded rubber into an intended shape in the same manner as in the case of crosslinking general rubber. It can also be obtained by carrying out crosslinking after that. Vulcanization is preferred as the crosslinking.

  The uncrosslinked composition prepared as described above can be molded and crosslinked by various molding methods such as an extruder, a calender roll or a press, but can be used for compression molding, injection molding, injection molding, etc. By molding, the characteristics can be most exerted when molding and crosslinking.

  That is, in the case of compression molding, a pre-weighed uncrosslinked compounded rubber is put in a mold, and after the mold is closed, heating is performed at a temperature of 120 to 270° C. for 30 seconds to 120 minutes, whereby a desired crosslinked rubber layer is obtained. can get.

  In the case of injection molding, a ribbon-shaped or pellet-shaped compounded rubber is supplied to a pot by a screw in a preset amount. Subsequently, the preheated compounded rubber is fed into the mold by a plunger in 1 to 20 seconds. After injecting the compounded rubber, by heating at a temperature of 120 to 270° C. for 30 seconds to 120 minutes, a target rubber layer can be obtained.

  In the case of injection molding, a pre-weighed compounded rubber is put into a pot and injected into a mold by a piston in 1 to 20 seconds. After injecting the compounded rubber, by heating at a temperature of 120 to 270° C. for 30 seconds to 120 minutes, the desired crosslinked rubber layer is obtained.

[Hulling roll]
The hulling roll of the present invention has the rubber layer on the surface of the core member. Usually, a hulling roll is obtained by baking a rubber layer on the surface of a core material and then subjecting the surface to polishing, finishing, or the like. As the core member, for example, a core member used in a conventionally known hulling roll such as a metal fitting drum can be used. Examples of the material of the core material include aluminum, stainless steel, iron, molybdenum, titanium and the like. Further, the shape and size of the core material are not particularly limited, and can be appropriately set according to the specifications of the hulling machine to which the hulling roll is attached and the JIS standard (JIS B 9214: rubber roll for chaffing) as in the conventional product.

  In the hulling roll of the present invention, a primer layer and/or an adhesive layer may be formed between the core material portion and the rubber layer in order to further improve the adhesion therebetween. Further, the outer peripheral surface of the core member may be subjected to a surface treatment for enhancing the adhesion with the rubber layer. The formation of the adhesive layer is not particularly limited as long as the effects of the present invention are exhibited, but can be performed using, for example, a phenolic adhesive or the like. Further, the formation of the primer layer is not particularly limited as long as the effects of the present invention are exhibited, but for example, it is performed using a urethane-based, polyester-based, silane-based, polyamide-based, phenol-based primer, a silane coupling agent, or the like. You can Examples of the surface treatment include formation of a roughened surface, and the formation of the roughened surface may be performed by, for example, blast treatment, grinding treatment, etching treatment, plating treatment, polishing treatment, oxidation treatment, or the like.

  The hulling roll preferably has a circularity of its cross section (cross section perpendicular to the rotation axis during use) of 0.5 mm or less. If the circularity exceeds 0.5 mm, the spacing between the hulling rolls may be greatly varied during use, and the removal rate may decrease or the rate of broken rice may increase.

  Further, according to the present invention, an agricultural thresher provided with the hulling roll can be suitably obtained.

[Manufacturing method of hulling roll]
The hulling roll can be manufactured, for example, by going through the following steps (1) and (2).

  (1) First, the core material portion is manufactured. The core member can be manufactured by a conventionally known method, for example, aluminum die casting. Then, if necessary, an adhesive layer and/or a primer layer is formed on the outer peripheral surface of the core member. In addition, the outer peripheral surface of the core material is surface-treated as necessary.

  (2) Next, the rubber layer is formed around the core member. As a forming method, for example, the core material is placed in a cylindrical mold, and then the composition is injected into a gap between the outer peripheral surface of the core material and the inner wall surface of the mold, and the composition is cured under predetermined conditions. By doing so, the rubber layer can be formed. The conditions can be referred to the above.

  The curing conditions are not particularly limited as long as the effects of the present invention are exhibited and can be set appropriately, but conditions for heating at 100 to 160° C. for 30 to 90 minutes can be usually adopted. In addition, after performing a curing treatment and releasing from the mold, post-curing may be performed, for example, at 100 to 160° C. for 3 to 48 hours.

  The composition according to the present invention has remarkably improved dispersibility of the filler and has suitable moldability, so that the composition can be suitably laminated on the surface of the core material part. Therefore, according to the present invention, having a uniform density over the entire surface of the core material, excellent in wear resistance and durability, a hulling roll formed with a rubber layer that can be used for a long time, It can be suitably manufactured.

  In the method for manufacturing a hulling roll, the surface of the rubber layer may be formed by grinding if necessary. Grinding may not be performed with the mold removed from the mold.

[How to use the hulling roll]
The hulling roll of the present invention is used by attaching two hulling rolls as a set to a conventionally known rubber roll type hulling machine (for example, an agricultural threshing machine).

  The pair of hulling rolls are usually attached to the hulling machine in parallel so as to have a predetermined interval, and rotate the hulling rolls in mutually opposite directions at different rotation speeds. Then, when paddy rice is put between the paddy rolls in this state, the chaff is removed from the paddy rice due to the difference in peripheral speed between the paddy rolls.

  The distance between the hulling roll gaps and the rotation speed (peripheral speed) of each hulling roll are not particularly limited. It may be set appropriately.

  Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto.

  In the examples and comparative examples, the following were used.

(1) Copolymer (A)
As an ethylene/α-olefin/non-conjugated polyene copolymer (A), Mitsui Chemicals Co., Ltd. Mitsui EPT (registered trademark) 4045M (structural unit derived from ethylene: 45% by weight, structural unit derived from diene: 7.6% by weight, Mooney viscosity ML ₍₁₊₄₎ (100° C.) (ASTM D 1646):45) was used.

(2) Copolymer (B)
As the ethylene/α-olefin/non-conjugated polyene copolymer (B), Mitsui Chemicals Co., Ltd. Mitsui EPT (registered trademark) K9720 (structural unit derived from ethylene: 77% by weight, structural unit derived from diene: 10.4% by weight, Mooney viscosity ML ₍₁₊₄₎ (100° C.) (ASTM D 1646): 20) was used.

(3) Filler (C)
As the filler (C), Silica VN3 GRType manufactured by Tosoh Silica Co., Ltd. (primary particle diameter: 15 nm, particle diameter of secondary aggregate: 18 μm, specific surface area: 200 m ² /g) was used.

  In the present invention, each physical property was evaluated as follows.

(1) Hardness test A flat portion of the vulcanized molded body was overlapped to have a length of 12 mm, and the hardness (durometer A hardness) was measured according to JIS K6253.

(2) Tensile test According to JIS K6251, a vulcanized molded product was subjected to a tensile test under the conditions of a measurement temperature of 23° C. and a tensile speed of 500 mm/min. The modulus at 25% elongation (M25) and the modulus at 50% elongation (M50 ), modulus at 100% elongation (M100), modulus at 200% elongation (M200), modulus at 300% elongation (M300), strength at break (TB) and elongation at break (EB).

(3) DIN friction test (DIN wear amount)
A disc-shaped test piece having a diameter of 16.0±0.2 mm and a thickness of 6 mm or more was prepared by using the vulcanized molded body according to JIS-K6264-2:2005, and the test piece was subjected to DIN abrasion. Using a testing machine, a drum having a diameter of 150.0±0.2 mm and a length of 500 mm was rotated at 40 times/min, a load of 1 kgf, and an abrasion distance of 40.0±0.2 m (amount of wear ( DIN wear amount: unit mg) was measured.

(4) Crosslinking Density After cutting a sheet-shaped sample into a size of 20 mm×20 mm×2 mmt, it is immersed in toluene at 37° C. for 72 hours to be swollen according to JIS K 6258 (1993), and then the Flory-Rehner formula (B) Then, the effective network chain density (crosslink density) was calculated.

In the formula (B), ν (pieces/cm ³ ) is the effective network chain density (crosslink density), the number of effective network chains in 1 cm ^{3 of} pure rubber, and V _R is the pure rubber in the swollen crosslinked rubber. is the volume fraction of, V ₀ is the molecular volume of the solvent, the μ rubber - an interaction constant = 0.49 between solvent, a is Avogadro's number.

(5) Payne effect (filler dispersion index)
A sample was punched out from the vulcanized product to prepare a test piece. The strain modulus dependence of the storage elastic modulus G′ of this sample was measured using a dynamic viscoelasticity tester. The measurement conditions are as follows.

Dynamic viscoelasticity tester (RDS): Rheometrics, Inc. Sample: Used by punching a 2 mm sheet into a circle with a diameter of 25 mm.

Temperature: 100°C
Distortion rate: 0.01% to 10%
Frequency: 10Hz
The storage modulus G′ at a strain rate of 0.01% thus obtained is G′ (0.01%), and the storage modulus G′ at a strain rate of 1.00% is G′ (1.00%). The sex index FDI (%) was calculated from the following formula (1).

FDI=G′(1.00%)/G′(0.01%)×100 (1)
[Comparative Example 1]
Using MIXTRON BB MIXER (manufactured by Kobe Steel, BB-4 type, volume 2.95 L, rotor 4WH), 105 parts by weight of silica (C) and 100 parts by weight of the copolymer (A) and a cup were used. 1 part by weight of silicon (Si69, manufactured by Evonik) as a ring agent, 1 part by weight of polyethylene glycol (PEG#4000, manufactured by Sanyo Chemical Industry Co., Ltd.) as a surfactant, and zinc oxide (zinc) as a vulcanization accelerator. 5 parts by weight of Hana, #1, manufactured by Huxui Tech Co., Ltd., 1 part by weight of stearic acid as a processing aid, and 15 parts by weight of process oil (Diana Process Oil PS-430, manufactured by Idemitsu Kosan Co., Ltd.) as a softening agent. Thus, a composition before vulcanization was obtained. The kneading conditions were as follows: the rotation speed of the rotor was 50 rpm, the floating weight pressure was 3 kg/cm ² , the kneading time was 5 minutes, and the kneading discharge temperature was 145° C.

  Then, after confirming that the temperature of the above compound was 40° C., a 6-inch roll was used to add di-2-benzothiazolyl disulfide (MBTS, Ouchi Shinko Chemical Industry Co., Ltd.) as a vulcanization accelerator to the compound. 0.5 parts by weight, N-cyclohexyl-2-benzothiazole sulfenamide (CBS, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) as a vulcanization accelerator, 0.5 parts by weight, vulcanization accelerator 1.0 part by weight of tetramethylthiuram disulfide (TMTD, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.), and 1.0% of zinc dibutyldithiocarbamate (ZnBDC, manufactured by Ouchi Shinko Chemical Industry Co., Ltd.) as a vulcanization accelerator. By weight, 1.0 part by weight of sulfur as a vulcanizing agent was kneaded. The kneading conditions were as follows: roll temperature: front roll/rear roll=50° C./50° C., roll rotation number: front roll/rear roll=18 rpm/15 rpm, roll gap: 5 mm, and kneading time: 8 minutes.

  Next, this compound was vulcanized at 180° C. for 15 minutes using a press molding machine to prepare a rubber sheet (vulcanized molded body) having a thickness of 2 mm.

  The obtained vulcanized molded product was subjected to hardness test, tensile test, DIN friction test, crosslink density and filler dispersion index by the above methods. The results are shown in Table 1.

[Example 1]
In Comparative Example 1, 100 parts by weight of the copolymer (A) was 60 parts by weight of the copolymer (A) and 40 parts by weight of the copolymer (B), and 105 parts by weight of silica (C) was 80 parts by weight. The same procedure as in Comparative Example 1 was carried out except that the above was carried out. The results are shown in Table 1.

[Example 2]
Comparative Example 1 was the same as Comparative Example 1 except that 100 parts by weight of the copolymer (A) was 100 parts by weight of the copolymer (B) and 105 parts by weight of silica (C) was 50 parts by weight. went. The results are shown in Table 1.

Claims (5)

A hulling roll having a rubber layer on the surface,
The rubber layer is
A following requirement (A-1) and the ethylene-alpha-olefin-non-conjugated polyene copolymer satisfies the (A-2) (A) from 0 to 60 parts by weight,
40 to 100 parts by weight of the ethylene/α-olefin/non-conjugated polyene copolymer (B) satisfying the following requirements (B-1) and (B-2) (however, the copolymer (A) and the copolymer). (The total of (B) is 100 parts by weight),
1 to 100 parts by weight of a filler (C) (excluding carbon black) satisfying the following requirement (C-1) based on 100 parts by weight of the total of the copolymer (A) and the copolymer (B). A hulling roll comprising a composition containing and.
(A-1) Containing 40 to 70% by weight of a structural unit derived from ethylene (E).
(A-2) The Mooney viscosity ML ₍₁₊₄₎ (100° C.) at 100° C. obtained by measuring according to ASTM D 1646 is 1 to 50.
(B-1) Containing more than 70% by weight and 99% by weight or less of a structural unit derived from ethylene (E).
(B-2) The Mooney viscosity ML ₍₁₊₄₎ (100° C.) at 100° C. obtained by measuring according to ASTM D 1646 is ₁ to 90.
(C-1) The average particle size is 10 μm to 50 μm.   The hulling roll according to claim 1, wherein the composition further contains a crosslinking agent (D).   The crosslinking agent (D) is a vulcanizing agent, and the vulcanizing agent is 0.1 to 20 parts by weight based on 100 parts by weight of the total amount of the copolymer (A) and the copolymer (B). The hulling roll according to claim 2, which contains the hulling roll.   The hulling roll according to any one of claims 1 to 3, wherein a durometer A hardness of the rubber layer measured according to JIS K6253 is 10 to 100. A method for manufacturing a hulling roll having a rubber layer on the surface,
The manufacturing method is
A following requirement (A-1) and the ethylene-alpha-olefin-non-conjugated polyene copolymer satisfies the (A-2) (A) from 0 to 60 parts by weight,
40 to 100 parts by weight of the ethylene/α-olefin/non-conjugated polyene copolymer (B) satisfying the following requirements (B-1) and (B-2) (however, the copolymer (A) and the copolymer). (The total of (B) is 100 parts by weight),
1 to 100 parts by weight of a filler (C) (excluding carbon black) satisfying the following requirements (C-1) based on 100 parts by weight of the total of the copolymer (A) and the copolymer (B). A method for producing a hulling roll, comprising the step of cross-linking the composition containing and in the presence of a cross-linking agent (D) to obtain a rubber layer.
(A-1) Containing 40 to 70% by weight of a structural unit derived from ethylene (E).
(A-2) The Mooney viscosity ML ₍₁₊₄₎ (100° C.) at 100° C. obtained by measuring according to ASTM D 1646 is 1 to 50.
(B-1) Containing more than 70% by weight and 99% by weight or less of a structural unit derived from ethylene (E).
(B-2) The Mooney viscosity ML ₍₁₊₄₎ (100° C.) at 100° C. obtained by measuring according to ASTM D 1646 is ₁ to 90.
(C-1) The average particle size is 10 μm to 50 μm.