WO2008007733A1

WO2008007733A1 - Rubber composition for conveyor belt and conveyor belt

Info

Publication number: WO2008007733A1
Application number: PCT/JP2007/063894
Authority: WO
Inventors: Jun Miyaji; Hiroaki Watanabe
Original assignee: The Yokohama Rubber Co., Ltd.
Priority date: 2006-07-14
Filing date: 2007-07-12
Publication date: 2008-01-17
Also published as: CN101490159B; AU2007273485A1; AU2007273485B2; JP2008038133A; JP4286298B2; CN101490159A

Abstract

Disclosed are a rubber composition for a conveyor belt and a conveyor belt which can maintain basic physical properties such as high rupture strength and high wear resistance and can reduce the power consumption to a satisfactory level. The rubber composition comprises a rubber component comprising natural rubber (NR) and polybutadiene rubber (BR), carbon black, silica, a silane coupling agent and diethylene glycol, wherein the ratio between the amount of natural rubber and the amount of polybutadiene rubber (NR/BR) in the rubber component is 80/20 to 25/75, the content of carbon black is 15 to 35 parts by mass based on 100 parts by mass of the rubber component, the content of silica is 5 to 25 parts by mass based on 100 parts by mass or the rubber component, the content of the silane coupling agent is 0.5 to 3 parts by mass based on 100 parts by mass of the rubber component, and the content of diethylene glycol is 0.5 to 4.5 parts by mass based on 100 parts by mass of the rubber component.

Description

Specification

Rubber composition for conveyor belt and conveyor belt

Technical field

[0001] The present invention relates to a rubber composition for a conveyor belt and a conveyor belt.

Background art

[0002] Comparator belts are often used for transportation of materials, etc.! /, But due to increased transport volume, improved transport efficiency, etc., there has been a demand for larger size and higher strength. Some km of things have also appeared.

For this reason, equipment costs and power consumption are increasing, and there is a need for belt conveyor systems that are low in cost and low power consumption.

Lower cost and lower power consumption of belt competitors are being studied.

[0003] For example, Patent Document 1 discloses that a belt inner surface rubber that is in contact with the pulley of a conveyor belt in a conveyor belt used in a conveyance system for an article that is wound around a driving pulley and an idle pulley and travels. The physical property loss factor (tan δ) and dynamic elastic modulus (E ') of 0.04≤tan 6≤0.12, E'≥

Conveyor belt characterized by that. ”And“ Conveyor belts used in the conveyance system of goods that run around the drive pulley and idle pulley, and the inner rubber of the conveyor belt is made of natural rubber 40 ~: LOO parts by weight, BR rubber 60 "Conveyor belt characterized in that 20 to 55 parts by weight of carbon black is blended with respect to a polymer of ~ 0 parts by weight."

[0004] Further, Patent Document 2 states that "in a conveyor belt provided with a cover rubber in contact with the belt support member on at least one of the upper and lower surfaces of the core layer, the cover rubber includes silica and a silane coupling agent. "Compare belt characterized by containing". "

Further, according to the present applicant, “a rubber composition for a conveyor belt containing 30 to 65 parts by mass of carbon black having colloidal characteristics shown below with respect to 100 parts by mass of a rubber component.

1) Nitrogen adsorption specific surface area (N SA) is 80 (m ² / g) or less 2) Iodine adsorption (IA) 70 (mg / g) or less

3) Dibutyl phthalate (DBP) oil absorption of 100 (cm ³ ZlOOg) or higher ”or“ loss factor at frequency 10 Hz, dynamic strain 2%, 20 ° C A rubber composition for a belt is proposed (see Patent Document 3;).

Further, Patent Document 4 states in claim 1 that “a rubber selected from the group consisting of the following: (a) natural rubber, rubber derived from a gen-based monomer, and mixtures thereof;

(b) about 0.1 force about lOphr of the following general formula (I):

[Chemical 1] Y

(Wherein R is a divalent acyclic aliphatic group having about 2 to 16 carbon atoms, a cycloaliphatic group having about 5 to 20 carbon atoms, and about 6 to 18 carbon atoms. Or an aromatic aromatic group having from about 7 to 24 carbon atoms, wherein these divalent groups may contain heteroatoms where 0, N and S forces are also selected; X is 0 Or an integer from 1 to 3; and Y is hydrogen or —CH.)

Three

Compound, and (c) about 0.1 force also about lOphr of the following general formula (Π):

[Chemical 2]

II

Wherein R ¹ is an alkylene group having 1 to 20 carbon atoms, a cycloalkylene group having 6 to 24 carbon atoms, an arylene group having 6 to 18 carbon atoms, or 7 to 25 carbons. Alkali monolene group having atoms and the following formula:

[Chemical 3]

--^ -JOiR ¹ -?-A group force consisting of a divalent group represented by-is selected. A rubber compound having improved vulcanization resistance comprising a bisbenzothiazolyldithio compound. And claim 2 in the form of a tire, hose, belt or shoe sole. The listed rubber compound. Is described.

Patent Document 1: Japanese Patent Application Laid-Open No. 11 139523

Patent Document 2: Japanese Patent Application Laid-Open No. 2004-10215

Patent Document 3: Japanese Unexamined Patent Application Publication No. 2004-18752

Patent Document 4: Japanese Patent Laid-Open No. 10-77361

Disclosure of the invention

Problems to be solved by the invention

[0008] However, the competitor belt described in Patent Document 1 aims to reduce power consumption by reducing the tan δ value. However, if the tan δ value is too small, the breaking strength (Τ

Β) and elongation at break (Ε) are also reduced, which may result in inferior tear strength and fatigue resistance.

Β

When the cover belt was running, the surface of the cover rubber, etc., was destroyed, causing a surface failure of the conveyor belt, resulting in unstable operation.

In addition, the conveyor belt described in Patent Document 2 has a problem that power consumption is not sufficiently reduced because the energy loss index is high.

Furthermore, the conveyor belt using the rubber composition for the conveyor belt described in Patent Document 3 has a high energy loss index, and therefore, due to differences in the belt operation line (for example, the gradient of the line or bending), In some cases, power consumption is not sufficiently reduced.

Furthermore, the belt using the compound described in Patent Document 4 has a tendency to be inferior in wear resistance when the natural rubber (NR) is more than 80 parts by mass. Also, if the NR is less than 25 parts by mass, the 25% modulus (Μ) decreases, the energy loss index (ΔΗ) increases, and the consumption

twenty five

There was a problem that the power could not be reduced. Furthermore, since the compound described in Reference 4 contains silica but does not contain a silane coupling agent and diethylene glycol, the loss factor tan δ and energy loss index (Δ Η) increase, and power consumption cannot be reduced. That was the problem.

[0009] Accordingly, an object of the present invention is to provide a rubber composition for a conveyor belt and a conveyor belt capable of maintaining basic physical properties such as high breaking strength and wear resistance and sufficiently reducing power consumption. To do.

Means for solving the problem [0010] As a result of intensive studies to solve the above problems, the present inventor has found that a rubber component comprising a specific proportion of natural rubber (NR) and polybutadiene rubber (BR), carbon black, silica, and silane coupling A rubber composition containing a specific amount of an agent and diethylene glycol, and a conveyor belt that forms a back surface using a rubber composition having specific values of loss factor tan δ and energy loss index (Δ Η) are high. The inventors have found that the basic physical properties such as breaking strength and wear resistance can be maintained and the power consumption can be sufficiently reduced, and the present invention has been completed.

That is, the present invention provides the following (1) to (15).

(1) Contains a rubber component consisting of NR and BR, carbon black, silica, a silane coupling agent, and diethylene glycol,

The amount ratio of NR and BR in the rubber component (NRZBR) force is 80Z20 to 25Z75, the content force of the carbon black is 15 to 35 parts by mass with respect to 100 parts by mass of the rubber component,

The content force of the silica is 5 to 25 parts by mass with respect to 100 parts by mass of the rubber component, The content force of the silane coupling agent is 0.5 to 3 parts by mass with respect to 100 parts by mass of the rubber component,

Content power of the diethylene glycol The rubber composition for a conveyor belt, which is 0.5 to 4.5 parts by mass with respect to 100 parts by mass of the rubber component.

(2) The composition according to (1), further comprising 1,3 bis (citraconimidomethyl) benzene and Ζ or hexamethylene-1,6 bis (thiosulfate) disodium salt-hydrate A rubber composition for a conveyor belt.

(3) Content power of the above 1,3 bis (citraconimidomethyl) benzene and Ζ or hexamethylene 1,6 bis (thiosulfate) disodium salt-hydrate 0.1. The rubber composition for a conveyor according to the above (2), which is 1 to 2 parts by mass.

(4) Nitrogen adsorption specific surface area (N SA) of the above silica is 100-250m

A 2 ² Zg above (1)

The rubber composition for a conveyor belt according to any one of to (3).

(5) The above-mentioned polybutadiene rubber (BR) force The rubber composition for a conveyor belt according to any one of (4).

(6) A conveyor belt having a top cover rubber layer, a reinforcing layer, and a bottom cover rubber layer force,

A conveyor belt, wherein at least the back surface of the lower surface cover rubber layer is formed of the rubber composition for a conveyor belt according to any one of (1) to (5) above.

[0013] (7) The loss factor tan δ measured by extending 10% at a measurement temperature of 20 ° C and giving a vibration with an amplitude of ± 2% at a frequency of 10 Hz was 0.04 to 0.07.

A rubber composition for a conveyor belt having an energy loss index (ΔΔ) represented by the following formula [1] of 0.080 or less.

A H = (SpGr X tan 6) / M [1]

twenty five

Where SpGr is specific gravity (g / cm ³ ) at 20 ° C, tan δ is 10% stretched at a measurement temperature of 20 ° C, and a vibration with an amplitude of ± 2% is given at a frequency of 10Hz. The measured loss factor, M, is

twenty five

The tensile stress (MPa) at 25% elongation.

(8) The rubber composition for a conveyor belt according to the above (7), which contains a rubber component consisting of NR and BR.

(9) The rubber composition for a conveyor belt according to the above (7), comprising a rubber component comprising NR and BR, carbon black, silica, a silane coupling agent, and diethylene glycol.

(10) Contains a rubber component consisting of NR and BR, carbon black, silica, a silane coupling agent, and diethylene glycol,

The content power of the diethylene glycol The rubber composition for a conveyor belt according to the above (7), which is 0.5 to 4.5 parts by mass with respect to 100 parts by mass of the rubber component. (11) The nitrogen adsorption specific surface area (N SA) of the silica is 100

2 to 250m ² Zg above (9

) Or (10) a rubber composition for a conveyor belt.

(12) The rubber composition for a conveyor belt according to any one of the above (8) to (11), which is a polybutadiene rubber (BR) force.

(13) The above (7), further comprising 1, 3 bis (citraconimidomethyl) benzene and Z or hexamethylene-1,6-bis (thiosulfate) disodium salt-hydrate The rubber composition for a conveyor belt according to any one of to (12).

(14) Content power of 1,3 bis (citraconimidomethyl) benzene and Z or hexamethylene 1,6 bis (thiosulfate) disodium salt-hydrate Above 100 parts by weight of rubber component The rubber composition for a conveyor belt according to the above (13), which is 0.1 to 2 parts by mass.

[0015] (15) A conveyor belt having a top cover rubber layer, a reinforcing layer, and a bottom cover rubber layer force,

A conveyor belt formed of the rubber composition for a conveyor belt according to any one of the above (7) to (14), wherein at least the back surface force of the lower surface cover rubber layer. The invention's effect

[0016] As described below, according to the present invention, it is possible to provide a conveyor belt that can maintain basic physical properties such as high breaking strength and wear resistance and can sufficiently reduce power consumption. Useful.

Brief Description of Drawings

FIG. 1 is a cross-sectional view schematically showing an example of a preferred embodiment of the first conveyor belt of the present invention.

Explanation of symbols

[0018] 1: Competition belt

2: Top cover rubber layer

3: Reinforcement layer

4: Bottom rubber layer

5: Conveying surface 11, 16: Outer layer

12, 15: Inner layer

BEST MODE FOR CARRYING OUT THE INVENTION

[0019] The present invention is described in detail below.

The rubber composition for a conveyor belt according to the first aspect of the present invention (hereinafter sometimes simply referred to as “the first rubber composition for a conveyor belt of the present invention”) includes a rubber component having NR and BR strength, carbon black And silica, a silane coupling agent, and diethylene glycol,

The ratio of NR and BR in the rubber component (NRZBR) force is 0Z20-25Z75, the carbon black content is 15-35 parts by mass with respect to 100 parts by mass of the rubber component, and the silica content The amount is 5 to 25 parts by mass with respect to 100 parts by mass of the rubber component, and the content of the silane coupling agent is 0.5 to 3 parts by mass with respect to 100 parts by mass of the rubber component. Is a rubber composition having a content of 0.5 to 4.5 parts by mass with respect to 100 parts by mass of the rubber component.

Next, each component of the rubber composition for the first conveyor belt of the present invention will be described in detail.

[0020] (Rubber component)

The rubber component is composed of NR and BR.

The ratio of NR and BR in the rubber component (NRZBR) force is 0Ζ20 ~ 25Ζ75, preferably 70/30 ~ 50/50, more preferably 70/30 ~ 60/40! / ヽ.

When the content ratio of NR and BR is in the above range, the resulting rubber composition for the first conveyor belt of the present invention has good rupture strength, wear resistance, and deviation after vulcanization, and the conveyor belt is good. The basic physical properties can be maintained. This is considered to be because the compatibility between NR and BR is improved and the reinforcement is further improved.

[0021] In the rubber composition for the first conveyor belt of the present invention, BR preferably has a weight average molecular weight of 500,000 or more, more preferably 550,000 or more. When the weight average molecular weight force is in the range, the resulting rubber composition for the first conveyor belt of the present invention has improved rupture strength and tear strength after vulcanization, and better wear resistance.

[0022] In the rubber composition for the first conveyor belt of the present invention, BR is a terminal-modified polymer. Preferable is butadiene rubber.

The terminal-modified polybutadiene rubber is not particularly limited as long as the terminal is modified BR. In addition, as a BR terminal modification method, for example, a method of modifying the BR terminal (active terminal) using a denaturant can be used.

Specific examples of such a modifier include halogenated tin such as tin tetrachloride and tin tetrabromide; halogenated organic tin compound such as tributyltin chloride; Examples of the compound include: a silicon compound such as triethylsilane; an isocyanate group-containing compound such as phenyl isocyanate; an amidy compound such as N-methylpyrrolidone (NMP); a ratata compound; a urea compound; and an isocyanuric acid derivative.

[0023] By using such a terminal-modified polybutadiene rubber, the loss coefficient _tan δ and energy threshold index (Δ Η) described later after vulcanization of the rubber composition for the first conveyor belt of the present invention obtained are obtained. Since both are in a favorable range, power consumption can be sufficiently reduced. This is thought to be because the modified end portion contributes to crosslinking and thus the crosslinking density after vulcanization increases.

[0024] Commercially available products can be used as the terminal-modified polybutadiene having a weight average molecular weight of 500,000 or more.

Specific examples include Nipol BR1250H (weight average molecular weight: 570,000, NMP-modified) manufactured by Nippon Zeon.

[0025] (Carbon black)

The carbon black is not particularly limited, but is preferably one containing GPF (General Purpose Furnace), and may contain other carbon blacks shown below.

[0026] Specifically, as other carbon black, for example, HAF (High Abrasion

Furnace), sAF (Super Abrasion Furnace), ISAF (Intermediate super Abrasion Furnace), FEF (Fast Extruding Furnace), SRF (Semi—Rein forcing Furnace), FT (Fine Thermal), MT (Medium Thermal), etc. It is.

[0027] Commercially available products can be used as such carbon black. Specific examples of GPF include Asahi # 55 (Asahi Carbon Co., Ltd.), Seast V (Tokai Carbon Co., Ltd.), Dia Black G (Mitsubishi Corporation), etc. Carbon Black), Show Black N339 (Showa Cabot) and the like.

In addition, ISAF is Show Black N220 (manufactured by Showa Cabot), SAF is Seast 9 (manufactured by Tokai Carbon Co., Ltd.), FEF is HTC # 100 (Nichinka Carbon Co., Ltd.), and SRF is Asahi # 50 ( Asahi Carbon Co., Ltd.), Mitsubishi Dia Black R (Mitsubishi Chemical Co., Ltd.), and FT include Asahi # 15 (Asahi Carbon Co.) and HTC # 20 (Nisshin Carbon Co.).

[0028] In the rubber composition for the first conveyor belt of the present invention, the content of such carbon black is 15 to 35 parts by mass with respect to 100 parts by mass of the rubber component, and 20 to 30 parts by mass. It is more preferable that the amount is 25 to 30 parts by mass.

If the carbon black content is within the above range, the resulting rubber composition for the first conveyor belt of the present invention will have good rupture strength and abrasion resistance after vulcanization, so that the basic physical properties as a conveyor belt can be obtained. In addition, the loss coefficient tan δ and energy loss index (Δ Η), both of which will be described later, are both in a favorable range, so that the power consumption can be sufficiently reduced. This is considered to be because the intermolecular interaction between the carbon black and the rubber component is large and the reinforcing property is improved.

[0029] In the rubber composition for the first conveyor belt of the present invention, the first conveyor belt of the present invention is formed from the rubber composition obtained by using at least GPF as such a carbon black. The energy loss index becomes better.

[0030] (Silica)

The silica is not particularly limited, and specific examples thereof include fumed silica, calcined silica, precipitated silica, ground silica, fused silica, anhydrous fine powder caustic acid, hydrous fine powder caustic acid, hydrous aluminum silicate, hydrous key. An acid calcium etc. are mentioned.

Of these, hydrous fine powdered caic acid is preferable because the resulting rubber composition for the first conveyor belt of the present invention has better rupture strength and wear resistance after vulcanization.

[0031] Commercially available products can be used as such silica. Specifically, examples of the hydrous fine powdered caic acid include -Pupseal AQ (manufactured by Nippon Silica Kogyo Co., Ltd.), Toxeal GU (manufactured by Tokuyama Co., Ltd.) and the like.

[0032] In the rubber composition for the first conveyor belt of the present invention, the content of such silica is 5 to 25 parts by mass and 10 to 20 parts by mass with respect to 100 parts by mass of the rubber component. Is preferred.

When the silica content is in the above-mentioned range, the loss coefficient tan δ and energy loss index (Δ Η), which will be described later, after vulcanization of the rubber composition for the first conveyor belt of the present invention to be obtained are good. Therefore, the power consumption can be sufficiently reduced. This is thought to be because the intermolecular interaction between silica and the rubber component can be made smaller than that of carbon black.

[0033] In the rubber yarn composite for the first conveyor belt of the present invention, such a silica has a nitrogen adsorption specific surface area (NSA) of 100 to 250 m.

It is preferable to use 2 ² Zg 125-2

I prefer to use OOm ² Zg.

Here, the nitrogen adsorption specific surface area is a surrogate property of the surface area that silica can use for adsorption with rubber molecules, and is measured by the amount of nitrogen adsorbed on the silica surface. When this value is in the above range, the loss coefficient tan δ and energy loss index (Δ Η) described later after vulcanization of the obtained rubber composition for the first conveyor belt of the present invention are both better ranges. Therefore, power consumption can be reduced more sufficiently.

[0034] (Silane coupling agent)

The silane coupling agent is preferably a polysulfide silane coupling agent used for rubber applications.

Specific examples of the polysulfide-based silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide and bis (3-triethoxysilylpropyl) disulfide.

Among them, the power of being bis (3-triethoxysilylpropyl) tetrasulfide is preferable because the resulting rubber composition for the first conveyor belt of the present invention has a better breaking strength after vulcanization.

[0035] As such a silane coupling agent, a commercially available product can be used. Specific examples include bis (3 triethoxysilylpropyl) tetrasulfide (Si69, manufactured by Degussa), bis (3-triethoxysilylpropyl) disulfide (Si75, manufactured by Degussa), and the like.

[0036] In the rubber composition for a first conveyor belt of the present invention, the content of such a silane coupling agent is 0.5 to 3 parts by mass with respect to 100 parts by mass of the rubber component. ~ 2 parts by weight are preferred.

When the content of the silane coupling agent is in the above range, the resulting rubber composition for the first conveyor belt of the present invention has good rupture strength after vulcanization. This is considered to be because the chemical bond between the silane coupling agent and the silica increases.

[0037] (Diethylene glycol)

The diethylene glycol is a compound represented by a chemical formula of (CH OHCH) O

2 2 2 As the diethylene glycol, a commercial product manufactured by Nippon Shokubai Co., Ltd. can be used.

[0038] In the rubber composition for a first conveyor belt of the present invention, the content of the diethylene glycol is 0.5 to 4.5 parts by mass with respect to 100 parts by mass of the rubber component, and 0.5 to 2 It is preferable that the amount is 0.6 parts by mass, more preferably 1.8 to 1.8 parts by mass.

If the content of diethylene glycol is in the above range, the loss coefficient tan δ and energy loss index (Δ Η) described later of the obtained rubber composition for the first conveyor belt of the present invention are both in a favorable range. The power consumption can be sufficiently reduced. This is considered to be because the interaction between molecules between silica and the rubber component can be reduced.

[0039] The rubber composition for the first conveyor belt of the present invention includes 1, 3 screws in addition to the components described above.

One preferred embodiment contains (citraconimidomethyl) benzene and メチル or hexamethylene 1,6 bis (thiosulfate) disodium salt-hydrate. Here, 1,3 bis (citraconimidomethyl) benzene is a compound represented by the following formula (1), and hexamethylene 1,6 bis (thiosulfate) disodium salt-hydrate is represented by the following formula: It is a compound represented by (2).

[0040] [Chemical 4]

Na ⁺ "O3S-S- (CH ₂ ) -S-SO3" Na ⁺ · 2H ₂ 0 (2)

[0041] By containing these compounds, the energy loss index (ΔΗ) described later of the obtained rubber composition for the first conveyor belt of the present invention is further reduced, and the power consumption can be more sufficiently reduced. Can do.

This is because the tensile stress (M) at 25% elongation described later of the obtained rubber composition for the first conveyor belt of the present invention is improved and the loss factor tan δ is reduced.

twenty five

In view of the fact that these compounds are reagents (reversion inhibitors) that prevent reversion (reversion) of the rubber composition, this is an unexpected effect.

[0042] In the rubber composition for the first conveyor belt of the present invention, the content of these compounds is

The amount of the rubber component is preferably 0.1 to 2 parts by mass, more preferably 0.2 to 1 part by mass with respect to 100 parts by mass of the rubber component.

In addition, this content is the total when 1,3-bis (citraconimidomethyl) benzene and hexamethylene-1,6-bis (thiosulfate) disodium salt-hydrate are both included. Refers to the content.

[0043] In the rubber composition for the first conveyor belt of the present invention, commercially available products can be used as these compounds.

Specifically, PERKALINK 900 manufactured by FLEXSYS can be used as 1,3-bis (citraconimidomethyl) benzene, and hexamethylene-1,6-bis (thiosulfate) disodium salt-hydrate. For example, DURALINK HTS manufactured by FLEXSYS can be used.

[0044] The rubber composition for the first conveyor belt of the present invention may contain a crosslinking agent or a vulcanization retarder such as a vulcanizing agent, a vulcanization aid, and a vulcanization accelerator in addition to the above-described components. Furthermore, various compounding agents may be contained as long as the object of the present invention is not impaired.

[0045] Examples of the vulcanizing agent include xio, organic peroxide, metal oxide, and phenol. Examples thereof include vulcanizing agents such as rosin and quinone dioxime.

Specific examples of the thio-based vulcanizing agent include powder, precipitation, high dispersibility, surface treatment, insoluble, dimorpholine disulfide, alkylphenol disulfide, and the like.

Specific examples of organic peroxide vulcanizing agents include benzoyl peroxide, t-butyl hydroperoxide, 2,4-dichlorobenzoic peroxide, 2,5 dimethyl-2,5 Examples include di (t-butylperoxy) hexane, 2,5 dimethylhexane 2,5 di (veroxylbenzoate), and the like.

Other examples include magnesium oxide, risurge, p-quinonedioxime, p-dibenzoylquinonedioxime, poly-p-dinitrosobenzene, and methylenedialine. Examples of the vulcanization accelerator include vulcanization accelerators such as aldehyde'ammonia, guazine, thiurea, thiazole, sulfenamide, thiuram, and dithiocarnomate.

Specific examples of the aldehyde 'ammonia-based vulcanization accelerator include hexamethyltetramine (H).

Specific examples of the guanidine vulcanization accelerator include diphenyl darazine and the like.

Specific examples of the thiourea vulcanization accelerator include ethylene thiourea.

Specific examples of the thiazole-based vulcanization accelerator include dibenzothiazyl disulfide (DM), 2-mercaptobenzothiazole and its Zn salt. Specific examples of the sulfenamide-based vulcanization accelerator include N-cyclohexyl-2-benzothiazolylsulfenamide (CZ), N-tbutyl-2-benzothiazolylsulfenamide (NS). Etc.

Specific examples of the thiuram vulcanization accelerator include tetramethylthiuram disulfide (TMTD), dipentamethylene thiuram tetrasulfide and the like.

Specific examples of the dithiocarbamate-based vulcanization accelerator include Na dimethyl dithiocarbamate, Zn dimethyldithiocarbamate, Te dimethyl dithiocarbamate, and the like. Mate, Cu-dimethinoresidiocarbamate, Fe-dimethinoresidiocarbamate, pipecoline pipecolyldithiocarbamate, and the like.

[0047] As the vulcanization aid, general rubber aids can be used together, and examples thereof include zinc white, stearic acid, oleic acid, and Zn salts thereof.

[0048] The total content of the vulcanizing agent, the vulcanization accelerator and the vulcanization aid is 0.1 to 10 parts by mass with respect to 100 parts by mass of the rubber component. Is more preferably 0.5 to 5 parts by mass. When the content range is within this range, the resulting rubber composition for the first conveyor belt of the present invention has a better rupture strength after vulcanization, and the loss coefficient tan δ and energy loss index (Δ Η) described later are also improved. Better.

[0049] Specific examples of the vulcanization retarder include, for example, organic acids such as phthalic anhydride, benzoic acid, salicylic acid, and acetylsalicylic acid; -Troso compounds such as polymers of naphthylamine, trosotrimethyl monodihydroquinoline; halides such as trichloromelanin; 2-mercaptobenzimidazole; santoguard PVI: and the like.

In the case of containing a vulcanization retarder, the content is preferably 0.1 to 0.3 parts by mass with respect to 100 parts by mass of the rubber component, and 0.1 to 0.2 parts by mass. Is more preferable. When the content range is within this range, the scorch stability when the conveyor belt is extruded from the resulting rubber composition for the first conveyor belt of the present invention is improved, and the productivity is improved.

[0050] Specific examples of the compounding agent include, for example, reinforcing agents (fillers) other than the above-described carbon black, anti-aging agents, antioxidants, pigments (dyes), plasticizers, thixotropic agents, Examples include ultraviolet absorbers, flame retardants, solvents, surfactants (including leveling agents), dispersants, dehydrating agents, antifungal agents, adhesion-imparting agents, antistatic agents, and processing aids.

As these compounding agents, those generally used for rubber compositions can be used. Their blending amounts are not particularly limited and can be arbitrarily selected.

[0051] The rubber composition for the first conveyor belt of the present invention is manufactured by adding the above-described rubber component, carbon black, silica, silane coupling agent, diethylene glycol, and various compounding agents as required, and kneading with a Banbury mixer or the like. Then, a vulcanizing agent, a vulcanization aid, and a vulcanization accelerator can be kneaded with a kneading roll machine or the like. Further, vulcanization can be carried out under the usual conditions. Specifically, for example, it is carried out by heating under conditions of a temperature of about 140 to 150 ° C. for 0.5 hours.

[0052] The conveyor belt according to the first aspect of the present invention (hereinafter sometimes simply referred to as "the first conveyor belt of the present invention") is a conveyor belt comprising an upper cover rubber layer, a reinforcing layer, and a lower cover rubber layer. In this case, the conveyor belt is formed from the rubber composition for the first conveyor belt of the present invention described above. Hereinafter, the force for explaining the first conveyor belt of the present invention with reference to FIG. 1 The structure of the first conveyor belt of the present invention is the rubber composition for the first conveyor belt of the present invention described above on the back surface of the bottom cover rubber layer. If you use a thing, it is not limited to this.

FIG. 1 is a cross-sectional view schematically showing an example of a preferred embodiment of the first conveyor belt of the present invention. In FIG. 1, 1 is a conveyor belt, 2 is a top cover rubber layer, 3 is a reinforcing layer, 4 is a bottom cover rubber layer, 5 is a transporting surface, 11 and 16 are outer layers, and 12 and 15 are inner layers.

As shown in FIG. 1, the conveyor belt 1 has a reinforcing layer 3 as a central layer, and an upper cover rubber layer 2 and a lower cover rubber layer 4 are provided on both sides thereof, and the upper cover rubber layer 2 includes an outer layer 11 and an inner layer. The two-layer force of 12 is also configured, and the bottom cover rubber layer 4 is also configured of the two-layer force of the outer layer 16 and the inner layer 15. Here, the outer layer and the inner layer (the outer layer 11 and the inner layer 12, the outer layer 16 and the inner layer 15) of the upper cover rubber layer 2 and the lower cover rubber layer 4 may be formed using different rubber compositions.

In FIG. 1, the upper cover rubber layer 2 is composed of two layers of an outer layer 11 and an inner layer 12. In the first conveyor belt of the present invention, the number of layers constituting the upper cover rubber layer 2 is It is not limited to 2 and may be 1 or 3 or more. In the case of 3 or more, these layers may be formed using different rubber compositions. The same applies to the bottom cover rubber layer 4.

It is desirable that the outer layer 11 constituting the transported material carrying surface 5 of the upper cover rubber layer 2 is also formed with a rubber composition having excellent heat resistance, wear resistance, oil resistance, etc. Therefore, the upper cover rubber layer 2 Is preferably composed of two-layer force.

The outer layer 16 constituting the back surface of the lower cover rubber layer 4 is the first competition of the present invention described above. The inner layer 15 of the lower cover rubber layer 4 is formed from other rubber composition covers because the manufacturing cost and the adhesion to the reinforcing layer 3 are important. Desirably, because the cover rubber layer 4 is composed of two-layer force, it is preferable.

[0055] The core of the reinforcing layer 3 is not particularly limited, and those used for ordinary competitor belts can be appropriately selected and used, and specific examples thereof include those that have the power of cotton and chemical fibers or synthetic fibers. Examples include rubber paste coated and infiltrated, RFL-treated one folded, special woven nylon canvas, steel cord, etc. These can be used alone or in combination. May be used.

In addition, the shape of the reinforcing layer 3 is not particularly limited, and may be a sheet shape as shown in FIG. 1. Wire-shaped reinforcing wires may be embedded in parallel.

[0056] The rubber composition for forming the inner layer 12 of the upper surface cover rubber layer 2 and the inner layer 15 of the lower surface cover rubber 4 is not particularly limited, and a rubber composition used for a normal competitor belt can be appropriately selected and used. These may be used alone or in combination of two or more.

[0057] The rubber composition for forming the outer layer 11 of the upper cover rubber layer 2 is not particularly limited, and a rubber composition used for an ordinary conveyor belt has a basic characteristic (for example, heat resistance) required for the outer layer. , Wear resistance, oil resistance, etc.) can be appropriately selected and used.

[0058] In the first conveyor belt of the present invention, at least the back surface of the lower surface cover rubber layer is formed of the rubber composition for the first conveyor belt of the present invention, so that the basic physical properties such as high breaking strength and wear resistance are maintained. Thus, the power consumption can be sufficiently reduced.

In the first conveyor belt of the present invention, the thickness force of the lower cover rubber layer is preferably 5 to 20 mm, more preferably 6 to 15 mm. Here, the thickness of the bottom cover rubber layer refers to the total thickness of these layers when the bottom cover rubber layer is composed of an inner layer and an outer layer.

When the thickness of the bottom cover rubber layer is within this range, even when a high-temperature transported article is used for transport, it is possible to prevent belt curling (cutting) caused by rubber deterioration or the like.

[0060] The method for producing the first conveyor belt of the present invention is not particularly limited, and is usually used. Etc. can be adopted.

Specifically, first, the raw materials are kneaded using a roll, an adader, a Banbury mixer, etc., then formed into a sheet shape for each cover rubber layer using a calendar, etc., and then each layer obtained A method in which the reinforcing layers are laminated in a predetermined order and pressed at a temperature of 140 to 170 ° C. for 10 to 60 minutes is preferably exemplified.

[0061] The rubber composition for a conveyor belt according to the second aspect of the present invention (hereinafter sometimes simply referred to as "the second rubber composition for a conveyor belt of the present invention") is measured at a measurement temperature of 20 ° C. The loss factor tan δ measured by stretching 10% and giving a vibration with an amplitude of ± 2% at a frequency of 10 Hz is 0.04 to 0.07.

The rubber composition has an energy loss index (ΔΗ) represented by the following formula [1] of 0.080 or less.

A H = (SpGr X tan 6) / M [1]

twenty five

The tensile stress (MPa) at 25% elongation.

[0062] The second aspect of the present invention focuses on energy loss in the belt compressor device (system), particularly energy loss that occurs when the conveyor belt crosses the roller during operation, and by reducing this energy loss, the belt compressor is reduced. The power consumption of the entire device is reduced.

Next, each physical property value defined by the rubber composition for the second conveyor belt of the present invention will be described in detail.

[0063] (loss factor tan δ)

The loss coefficient tan δ is the storage elastic modulus E 'representing the dynamic properties of the rubber composition and the loss elastic modulus 弾性

The ratio of tan S = E "/ Έ ', the smaller the value, the smaller the amount of energy (energy loss) dissipated as heat during the deformation of the rubber composition. It can be used as a measure of rusty loss.

On the other hand, if the tan δ value is small, power consumption can be reduced. However, as described in [Problems to be solved by the invention], if the tan δ value is too small, the breaking strength ( Since the T) and elongation at break (E) also decrease, the operation of the conveyor belt is not stable.

B B

Therefore, in the present invention, the tan δ value is set within a specific range so that both low power consumption and basic physical properties such as breaking strength and elongation at break can be achieved, and that the composite belt can be used for a conveyor line requiring a high physical property. It is said.

[0064] Therefore, the loss coefficient tan δ of the rubber composition for the second conveyor belt of the present invention is 0.04 to 0.07, preferably 0.05 to 0.07, and preferably 0.05 to 0.0. The force of becoming 065 is more preferable, and the force of 0.055 to 0.065 is more preferable! / ヽ.

In the present invention, the loss factor tan δ is a strip shape (length: 20 mm) from a vulcanized product obtained by vulcanizing the rubber composition for the second conveyor belt of the present invention at 148 ° C for 30 minutes. (X width 5mm X thickness 2mm) Using a test piece cut out at a measurement temperature of 20 ° C, stretched 10% and measured the loss factor when measured by giving a vibration with an amplitude of ± 2% at a frequency of 10Hz. Say.

[0065] (Energy Loss Index (ΔH))

The energy loss index (ΔΗ) is expressed by the above equation [1].

The above formula [1] is considered to be effective in the evaluation of the force used as an index of the friction reduction efficiency with the road surface used in the field of conventional tires, and the power consumption reduction of the rubber composition for the conveyor belt.

SpGr in the above formula [1] indicates a specific gravity (g / cm ³ ) at 20 ° C. If this value is small, the total mass can be reduced, and the same low power consumption effect as a small load can be obtained.

In addition, tan δ in the above equation [1] affects the energy loss due to deformation of the rubber composition at the time of overcoming the roller, as described above. This value is small! /, And a low power consumption effect is obtained. In addition, Μ in the above equation [1] is a force vector indicating a tensile stress (MPa) at 25% elongation.

twenty five

Since it can be considered as a substitute characteristic of hardness as the default stiffness, it affects the amount of stagnation of the rubber composition. When this value is large, the stagnation is reduced and a low power consumption effect is obtained. In the present invention, M represents the rubber composition for the second conveyor belt of the present invention at 148 ° C., 30

twenty five

Using a test piece punched out in the shape of No. 3 dumbbell from a vulcanized product obtained by vulcanization under the conditions of min., According to JIS K6251-2004, a tensile test was performed at a tensile speed of 500 mmZ, and 25% elongation was achieved. The tensile stress (M) [MPa] at the time measured at room temperature. Therefore, the technical significance of the above equation [1] is that the product of SpGr and tan δ is divided by Μ.

twenty five

Therefore, based on these physical properties, it is possible to comprehensively determine the energy intensity when the rubber composition gets over the roller, and whether the rubber composition for the conveyor belt is suitable for a conveyor belt that reduces power consumption. It is to be an indicator of whether or not.

[0066] Therefore, the energy loss effect number (Δ Ρί) shown in the above formula [1] of the rubber composition for the second conveyor belt of the present invention is 0.080 or less and 0.07 or less. A force of less than 0.07 is more preferred than S, and a force of 0.030 to 0.065 is even more preferred! /.

[0067] As described above, the rubber yarn for a second conveyor belt according to the present invention has a loss coefficient tan δ measured under a predetermined condition of 0.04 to 0.07, and energy represented by the above formula [1]. The rubber composition has a loss index (厶 11) of 0.080 or less.

Here, despite the fact that tan δ is defined in the above formula [1], the value of the loss factor tan δ is defined in the range of 0.04 to 0.07 is simply the energy loss index (Δ This is because even if Η) is 0.080 or less, if tan δ is less than 0.04, basic physical properties such as breaking strength and breaking elongation cannot be secured.

[0068] The rubber composition for the second conveyor belt of the present invention preferably contains a rubber component composed of NR and BR. By containing a rubber component consisting of NR and BR, the rubber composition for the second conveyor belt of the present invention has good rupture strength and abrasion resistance after vulcanization, and maintains the basic physical properties as a competitor belt. be able to.

Here, as BR, those detailed in the rubber composition for the first conveyor belt of the present invention can be used, and for the same reason as in the rubber composition for the first conveyor belt of the present invention, the weight average is used. It is preferable that the molecular weight is 500,000 or more, and end-modified polybutadiene is preferable.

[0069] The rubber composition for the second conveyor belt of the present invention preferably contains a rubber component having NR and BR strength, carbon black, silica, a silane coupling agent, and diethylene glycol. . By containing not only NR and BR, but also carbon black, silica, silane coupling agent and diethylene glycol, the rubber composition for the second conveyor belt of the present invention has any rupture strength and abrasion resistance after vulcanization. As a result, the basic physical properties of the conveyor belt can be maintained and the loss factor tan δ and Since the energy loss index (ΔΗ) is in a better range, the power consumption can be reduced more sufficiently.

Here, as carbon black, silica, silane coupling agent, and diethylene glycol, those detailed in the rubber composition for the first conveyor belt of the present invention can be used.

[0070] Further, the rubber composition for the second conveyor belt of the present invention contains a rubber component having NR and BR force, carbon black, silica, a silane coupling agent, and diethylene glycol, and the rubber component The ratio of NR to BR (NRZBR) force is 0 to 20 to 25 to 75, the carbon black content is 15 to 35 parts by mass with respect to 100 parts by mass of the rubber component, and the silica content is the rubber. It is 5 to 25 parts by mass with respect to 100 parts by mass of the component, the content of the silane coupling agent is 0.5 to 3 parts by mass with respect to 100 parts by mass of the rubber component, and the content of the diethylene glycol is the above The amount is preferably 0.5 to 4.5 parts by mass with respect to 100 parts by mass of the rubber component. By containing specific amounts of carbon black, silica, silane coupling agent, and diethylene glycol, the rubber composition for the second conveyor belt of the present invention has good rupture strength and abrasion resistance after vulcanization, so that it can be used as a conveyor belt. In addition to maintaining the basic physical properties, the loss factor tan δ and the energy loss index (Δ Η) are in a better range, so the power consumption can be further reduced.

[0071] In the rubber composition for a second conveyor belt of the present invention, the amount it (NR / BR) of NR and BR in the rubber component is more preferable than a force S of 70/30 to 50/50, More preferably, it is 70 / 30-60 / 40.

The carbon black content is more preferably 25-30 parts by mass, more preferably 20-30 parts by mass with respect to 100 parts by mass of the rubber component.

Further, the content of the silica is more preferably 10 to 20 parts by mass with respect to 100 parts by mass of the rubber component.

In addition, the content of the silane coupling agent is more preferably 1 to 2 parts by mass with respect to 100 parts by mass of the rubber component.

The diethylene glycol content is 0 with respect to 100 parts by mass of the rubber component. More preferably, it is 5 to 2 parts by mass, and still more preferably 0.6 to 1.8 parts by mass.

[0072] Further, in the rubber composition for the second conveyor belt of the present invention, the silica has a nitrogen adsorption specific surface area (NSA) of 100 as in the case of the rubber composition for the first conveyor belt of the present invention.

2

～250M ² is more preferable to use those preferred instrument 125~200m ² Zg to use one of the Zg.

[0073] The rubber composition for the second conveyor belt of the present invention is the same as the rubber composition for the first conveyor belt of the present invention, such as 1,3 bis (citraconimidomethyl) benzene and Z or hexamethylene 1,6 bis. It is one of the preferred embodiments to contain (thiosulfate) disodium salt-hydrate.

Here, similarly to the rubber composition for the first conveyor belt of the present invention, 1,3 bis (citraconimidmethyl) benzene is a compound represented by the above formula (1), and hexamethylene 1,6 bis (thiosulfate). ) Disodium salt dihydrate is a compound represented by the above formula (2).

[0074] By containing these compounds, the energy loss index (Δ の) of the obtained rubber composition for the second conveyor belt of the present invention becomes smaller, and the power consumption can be more sufficiently reduced.

This is because the obtained rubber composition for the second conveyor belt of the present invention has an improved tensile stress (M) at 25% elongation and a smaller loss factor tan δ.

twenty five

In view of the fact that the product is an anti-reversion agent for rubber compositions, this is an unexpected effect.

[0075] In the rubber composition for the second conveyor belt of the present invention, the content of these compounds is

This content is the total content when both 1,3bis (citraconimidomethyl) benzene and hexamethylene-1,6-bis (thiosulfate) disodium salt-hydrate are contained. Say quantity.

In the rubber composition for the second conveyor belt of the present invention, commercially available products similar to the rubber composition for the first conveyor belt of the present invention can be used as these compounds.

[0077] The rubber composition for the second conveyor belt of the present invention includes a vulcanizing agent, a vulcanizing agent, in addition to the components described above. It may contain a crosslinking agent and a vulcanization retarder such as a vulcanization aid and a vulcanization accelerator, and may further contain various compounding agents as long as the object of the present invention is not impaired.

Here, as vulcanizing agents, vulcanization aids, vulcanization accelerators, vulcanization retarders and various compounding agents

Those detailed in the rubber composition for the first conveyor belt of the present invention can be used.

The competitor belt according to the second aspect of the present invention (hereinafter sometimes simply referred to as “second conveyor belt of the present invention”) is a conveyor belt comprising an upper cover rubber layer, a reinforcing layer, and a lower cover rubber layer. In this case, the conveyor belt is formed by the rubber composition for the second conveyor belt of the present invention described above. That is, the second conveyor belt of the present invention is used in the above-described first conveyor belt of the present invention, and instead of the rubber composition for the first conveyor belt of the present invention, the rubber for the second conveyor belt of the present invention. The composition is used, and the other configuration is the same as that of the first conveyor of the present invention.

[0079] In the second conveyor belt of the present invention, at least the back surface of the lower surface cover rubber layer is formed of the rubber composition for the second conveyor belt of the present invention, so that the basic physical properties such as high breaking strength and wear resistance are maintained. Thus, the power consumption can be sufficiently reduced.

[0080] The method for producing the second conveyor belt of the present invention is not particularly limited, and a commonly used method or the like can be adopted, and the second conveyor belt can be produced by the same method as the first conveyor belt of the present invention.

Example

[0081] The rubber composition for a conveyor belt of the present invention will be described in more detail below with reference to examples, but the present invention is not limited to these.

(Examples 1 to 26, Comparative Examples 1 to 8, Reference Examples 1 and 2)

Each rubber composition for a conveyor belt was prepared with the composition components (parts by mass) shown in Table 1 below with respect to 100 parts by mass of the rubber components. About each obtained rubber composition, the various physical properties after vulcanization were measured and evaluated by the method shown below. The results are shown in Table 1 below.

Reference Examples 1 and 2 were prepared by preparing rubber compositions similar to Example 5 and Comparative Example 2 described in JP-A-11 139523. Both reference examples are silica, Since it contained tylene glycol and a silane coupling agent, it became a comparative example, and physical properties other than abrasion resistance were measured and evaluated by the methods shown below.

[0082] <Physical properties after vulcanization>

(1) Breaking strength

Each obtained rubber composition was vulcanized at 148 ° C. for 30 minutes to prepare a vulcanized rubber composition. A tensile test at a tensile speed of 500 mmZ was performed in accordance with JIS K6251-2004 using a test piece punched out from each vulcanized rubber composition prepared in the shape of No. 3 dumbbell, and its breaking strength (T

B

) [MPa] was measured at room temperature.

If the breaking strength is 14 MPa or more, it can be evaluated as having a high breaking strength.

[0083] (2) Abrasion resistance

A DIN abrasion test was conducted in accordance with JIS-K6264-2-2005 using a test piece cut out from each prepared vulcanized rubber composition into a disc shape (diameter: 16.2 mm X thickness: 6 mm). The amount of wear (mm ³ ) when the DIN wear test was performed at room temperature was measured.

As a result, those whose wear amount was 120 mm ³ or less were evaluated as “◯” as having wear resistance.

[0084] (3) Loss coefficient tan δ

Cut out each vulcanized rubber composition into strips (length 20mm x width 5mm x thickness 2mm)! Using the test piece, the loss factor t an δ using a viscoelastic spectrometer manufactured by Toyo Seiki Seisakusho Was measured. The measurement was performed by extending 10% at a measurement temperature of 20 ° C. and applying a vibration with an amplitude of ± 2% at a frequency of 10 Hz.

[0085] (4) Energy loss index (ΔH)

The specific gravity of each prepared vulcanized rubber composition was measured.

Also, using a test piece punched from each vulcanized rubber composition prepared in the shape of No. 3 dumbbell, a tensile test was conducted at a tensile speed of 500 mmZ according to JIS K6251-2004, and at 25% elongation Tensile stress (M) [MPa] was measured at room temperature.

twenty five

Then, using specific gravity, M and the value of loss factor tan δ measured above, it was prepared

twenty five

The energy loss index (ΔΗ) of each vulcanized rubber composition was determined from the above formula [1].

[0086] [Table 1] Table 1 (Part 1)

[0087] [Table 2]

Table 1 (Part 2)

[0088] [Table 3] Table 1 (Part 3)

[0089] [Table 4]

Table 1 (Part 4)

[0090] [Table 5] Table 1 (Part 5)

[0091] [Table 6]

Table 1 (Part 6)

[0092] As the composition components such as the rubber component shown in Table 1 above, those shown below were used. 'Natural Rubber (NR): RSS # 3

• Polybutadiene rubber (VCR): VCR617 (manufactured by Ube Industries)

• BRl: Nipol BR1220 (weight average molecular weight: 460,000, terminal unmodified, manufactured by Nippon Zeon) • BR2: Nipol BR1250H (weight average molecular weight: 570,000, terminal NMP modified, manufactured by Nippon Zeon)

• Carbon Black 1: HAF (Show Black N339, Showa Cabot)

'Carbon black 2: GPF (Diablack G, manufactured by Mitsubishi Chemical Corporation)

• Silica 1: Hydrous fine powdered caic acid (Nitrogen adsorption specific surface area (N SA): 202m ² / g, -Pseal

2

AQ, manufactured by Nippon Silica Industry Co., Ltd.)

Silica 2: Hydrous fine powdered caic acid (Nitrogen adsorption specific surface area (N SA): 120 m ² / g, Toxeal G

2

(Made by Uto Tokama)

・ Silica 3: Hydrous fine powdered caic acid (Nitrogen adsorption specific surface area (N SA): 144m ² / g, Zeosil 165

2

GR, manufactured by Rhodia Silica korea)

• Silica 4: Hydrous fine powdered caic acid (Nitrogen adsorption specific surface area (N SA): 159m ² / g, Ultrasil 700

2

0GR, manufactured by United Silica Industrial;)

• Diethylene glycol: manufactured by Nippon Shokubai Co., Ltd.

• Silane coupling agent: bis (3-triethoxysilylpropyl) tetrasulfide (Si69, manufactured by Degussa)

• Vulcanizing agent 1: Sulfur (oil-treated sulfur, manufactured by Hosoi Chemical Co., Ltd.)

• Vulcanization accelerator 1: N-tert butyl 2-benzothiazolylsulfenamide (Noxera I NS, manufactured by Ouchi Shinsei Chemical Co., Ltd.)

Anti-reversion agent 1: 1, 3 Bis (citraconimidomethyl) benzene (PERKALIN K 900, manufactured by FLEXSYS)

• Reversion inhibitor 2: Hexamethylene 1, 6 bis (thiosulfate) disodium salt-hydrate (DURALINK HTS, manufactured by FLEXSYS)

From the results shown in Table 1, the rubber compositions obtained in Examples 1 to 26 maintain the basic physical properties such as high rupture strength and wear resistance and reduce power consumption from the physical properties after vulcanization. It has become a component that it is a rubber thread and a composition suitable for a competitor belt that can be sufficiently planned. In contrast, a rubber composition containing no diethylene glycol or the like (Comparative Examples 1 to 5), a rubber composition containing a rubber component with a low NR ratio (Comparative Example 6), a high V amount of carbon black, a rubber composition ( The rubber composition (Comparative Example 8) and the rubber compositions of Reference Examples 1 and 2 have a high energy loss index (ΔΗ) due to their physical properties after vulcanization. It has become a component that the rubber composition is insufficient in reducing power consumption.

[0094] Further, in the rubber compositions obtained in Examples 13 to 21 containing the anti-reversion agent, the M is improved and the loss factor tan δ is reduced, so that the energy loss index (ΔΗ) is smaller.

twenty five

As a result, it has become a component that it is a rubber thread suitable for a conveyor belt that can sufficiently reduce power consumption.

In particular, the rubber compositions obtained in Examples 18 to 21 containing silica containing an anti-reversion agent and having a nitrogen adsorption specific surface area in a suitable range (125 to 200 m ² / g) are as follows:

25 Since the loss factor tan δ is improved and the energy loss index (Δ Η) is smaller, the rubber yarn and the composition suitable for the conveyor belt can reduce power consumption more sufficiently. However, it was divided.

[0095] Furthermore, the rubber compositions obtained in Examples 24 to 26 containing BR having a weight average molecular weight of 500,000 or more and having a terminal-modified polybutadiene as a BR have improved wrinkles and a loss factor. ta

twenty five

Since η δ is reduced, the energy loss index (Δ 更に) is further reduced, and it is found that the rubber yarn is suitable for a conveyor belt that can further reduce power consumption.

Claims

The scope of the claims

[1] Contains a rubber component made of natural rubber (NR) and polybutadiene rubber (BR), carbon black, silica, silane coupling agent, and diethylene glycol.

The ratio of natural rubber to polybutadiene rubber in the rubber component (NRZBR) is 1S 80/20 to 25Z75,

The carbon black content is 15 to 35 parts by mass with respect to 100 parts by mass of the rubber component,

The silica content is 5 to 25 parts by mass with respect to 100 parts by mass of the rubber component, and the content force of the silane coupling agent is 0.5 to 3 parts by mass with respect to 100 parts by mass of the rubber component. ,

Content power of the diethylene glycol 0.5 to 4 to 100 parts by mass of the rubber component

A rubber composition for a conveyor belt, which is 5 parts by mass.

[2] The composition according to claim 1, further comprising 1,3-bis (citraconimidomethyl) benzene and Z or hexamethylene-1,6-bis (thiosulfate) disodium salt-hydrate. A rubber composition for a conveyor belt.

[3] Content power of the 1,3-bis (citraconimidomethyl) benzene and Z or the hexamethylene-1,6-bis (thiosulfate) disodium salt-hydrate 100 parts by mass of the rubber component The rubber composition for a conveyor belt according to claim 2, wherein the rubber composition is 0.1 to 2 parts by mass relative to the mass.

[4] The nitrogen adsorption specific surface area (NSA) of the silica is 100 to 250 m ² Zg.

2

A rubber composition for a conveyor belt according to any one of the above.

[5] The polybutadiene rubber (BR) force is a terminally modified polybutadiene rubber.

V, rubber composition for a conveyor belt according to any one of the above.

[6] A conveyor belt comprising an upper cover rubber layer, a reinforcing layer, and a lower cover rubber layer,

A conveyor belt formed by the rubber composition for a conveyor belt according to any one of claims 1 to 5, wherein at least a back surface force of the lower surface cover rubber layer.

[7] At a measurement temperature of 20 ° C, stretch 10% and give a vibration with an amplitude of ± 2% at a frequency of 10Hz. Yanagi's determined loss factor tan δ force SO. 04-0.

Δ Η = (SpGr X tan δ) / Μ [1]

twenty five

The tensile stress (MPa) at 25% elongation.

[8] Claims containing a rubber component comprising natural rubber (NR) and polybutadiene rubber (BR)

8. The rubber composition for a conveyor belt according to 7.

[9] The rubber composition for a conveyor belt according to claim 7, comprising a rubber component comprising natural rubber (NR) and polybutadiene rubber (BR), carbon black, silica, a silane coupling agent, and diethylene glycol. .

[10] A rubber component comprising natural rubber (NR) and polybutadiene rubber (BR), carbon black, silica, a silane coupling agent, and diethylene glycol.

Ratio of natural rubber to polybutadiene rubber in the rubber component (NRZBR) 1S 80/20

~ 25Z75,

The rubber composition for a conveyor belt according to claim 7, wherein the content power of the diethylene glycol is 0.5 to 4.5 parts by mass with respect to 100 parts by mass of the rubber component.

[11] The silica has a nitrogen adsorption specific surface area (N SA) of 100 to 250 m.

The rubber composition for a conveyor belt according to claim 9 or 10, wherein the rubber composition is 2 ² Zg.

12. The rubber composition for a conveyor belt according to any one of claims 8 to 11, wherein the rubber composition is a polybutadiene rubber (BR) force terminal-modified polybutadiene rubber.

[13] In addition, 1,3-bis (citraconimidomethyl) benzene and Z or hexamethyle The rubber composition for a conveyor belt according to any one of claims 7 to 12, comprising N-1,6-bis (thiosulfate) disodium salt-hydrate.

[14] Content power of the 1,3-bis (citraconimidomethyl) benzene and Ζ or hexamethylene-1,6-bis (thiosulfate) disodium salt-hydrate 100 parts by mass of the rubber component 14. The rubber composition for a conveyor belt according to claim 13, wherein the rubber composition is 0.1 to 2 parts by mass relative to the mass.

[15] A conveyor belt comprising an upper cover rubber layer, a reinforcing layer, and a lower cover rubber layer,

A conveyor belt formed by the rubber composition for a conveyor belt according to any one of claims 7 to 14, wherein at least the back surface force of the lower surface cover rubber layer.