JP2018188525A - Rubber cement composition and conveyor belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber cement composition which does not obstruct vulcanization adhesion between rubber members and is excellent in workability and adhesion with the rubber member, when containing no toluene as an organic solvent.SOLUTION: A rubber cement composition contains a rubber component containing natural rubber and a styrene-butadiene rubber, 30-65 pts.mass of at least one carbon black (A) selected from SAF, ISAF, HAF, MAF, FEF, GPF and SRF based on 100 pts.mass of the rubber component, and an organic solvent which has a distillation point at 1,013 hPa of 60-130°C and contains no toluene, where a content of the organic solvent is 70-95 mass%, preferably 80-92 mass%. The composition further contains at least one carbon (B) selected from FEF, GPF and SRF, where the carbon black (A) and the carbon (B) are different carbons, and a mass ratio of the contents of the carbon blacks (A) and (B) is 20:80 to 8:20.SELECTED DRAWING: None

Description

  The present invention relates to a rubber cement composition and a conveyor belt.

  Conveyor belts carry materials such as ores, earth and sand, cement, foods such as grains and fruits, or a variety of transported items such as boxes and bags packed with products on them, and keep a predetermined section stably. It is a component part of a belt conveyor device used in various places as a transportation means for transportation. Since this conveyor belt deteriorates with repeated use, it needs to be repaired or replaced over time.

  When replacing the conveyor belt, the new rubber for the conveyor belt is placed on a core material such as canvas or steel cord, which is a reinforcing material, and then vulcanized to join the ends (endless processing). Is given. Moreover, about this endless process, it is necessary to fix in the state which connected the edge parts of the rubber for conveyor belts until it vulcanizes. However, the fixing is technically difficult, and there is a problem that the connecting portion of the conveyor belt after endless processing is displaced and a problem that durability of the connecting portion is lowered.

Therefore, a rubber cement composition containing a rubber component and an organic solvent is used for the purpose of temporarily joining the end portions of the rubber for the conveyor belt. Since this rubber cement composition serves as an adhesive, it can be fixed in a state where the ends of the rubber for the conveyor belt are joined together.
This rubber cement composition has a viscosity (processability) suitable for coating, and needs to have adhesion before vulcanization with a rubber for a conveyor belt (hereinafter sometimes simply referred to as “adhesion”). There is. And about the organic solvent used for a rubber cement composition, it is common to use toluene which has moderate volatility (short drying time), and was excellent in workability and compatibility with a rubber component. there were.

  However, since toluene that has been used as an organic solvent has a large environmental load, it is desired to use an alternative material that has a low environmental load as the organic solvent. However, at present, there is no rubber cement composition that does not contain toluene, and there is no rubber cement composition that has the same processability and adhesion as the rubber cement composition that uses toluene.

  An object of the present invention is to provide a rubber cement composition excellent in processability and adhesion to a rubber member without inhibiting vulcanization adhesion between the rubber members even when toluene is not included as an organic solvent. It is to provide. Another object of the present invention is to provide a conveyor belt that is excellent in bondability after endless processing.

  The inventors of the present invention have intensively studied to achieve the above object. In addition to using a specific rubber component and carbon black, an organic solvent having a specific distillation point is used, and by optimizing the content of the organic solvent in the rubber cement composition, toluene is used as the organic solvent. Even if it is not used, it has been found that excellent workability and adhesion to the rubber member can be realized without inhibiting the vulcanization adhesion between the rubber members, and the present invention has been completed.

That is, the rubber cement composition of the present invention comprises a rubber component containing natural rubber and styrene butadiene rubber, and 30 to 65 parts by mass of SAF, ISAF, HAF, MAF, FEF, 100 parts by mass of the rubber component, Including at least one carbon black selected from the group consisting of GPF and SRF, an organic solvent having a distillation point at 1013 hPa of 60 to 130 ° C. and not containing toluene, and the content of the organic solvent is 70 It is -95 mass%.
By the said structure, the outstanding workability and adhesiveness with a rubber member are realizable, without inhibiting the vulcanization adhesion | attachment between rubber members.

  Moreover, in the rubber cement composition of this invention, it is more preferable that content of the said organic solvent is 80-92 mass%. This is because processability and adhesion to the rubber member can be achieved at a higher level.

  Furthermore, in the rubber cement composition of the present invention, the carbon black is at least one selected from the group consisting of SAF, ISAF, HAF, MAF and FEF (carbon black A), and a group consisting of FEF, GPF and SRF. It is preferable that the carbon black A and the carbon black B are different from each other, and the carbon black A content and the carbon black B content are preferably selected. Is more preferably in the range of 20:80 to 80:20. This is because processability and adhesion to the rubber member can be achieved at a higher level.

  The rubber cement composition of the present invention preferably further contains a cobalt-containing compound. This is because the adhesiveness after vulcanization with a rubber member, canvas, core material or the like can be further improved.

  Furthermore, the rubber cement composition of the present invention is preferably used for a conveyor belt. This is because the bondability after endless processing of the conveyor belt can be improved.

The conveyor belt of the present invention is characterized by using the rubber cement composition described above.
With the above configuration, excellent bondability after endless processing can be realized.

  According to the present invention, even when toluene is not included as an organic solvent, a rubber cement composition excellent in processability and adhesion to a rubber member is provided without inhibiting vulcanization adhesion between rubber members. it can. Moreover, according to this invention, the conveyor belt excellent in the joining property after an endless process can be provided.

<Rubber cement composition>
Hereinafter, an embodiment of the rubber cement composition of the present invention will be described in detail.
The rubber cement composition of the present invention includes a rubber component, carbon black, and an organic solvent.

(Rubber component)
The rubber cement composition of the present invention includes a rubber component containing natural rubber (NR) and styrene butadiene rubber (SBR).
By containing natural rubber in the rubber component, tackiness can be imparted to the rubber component, and adhesion between the rubber cement composition of the present invention and the rubber member can be improved. In addition, by containing styrene butadiene rubber in the rubber component, the processability of the rubber cement composition of the present invention can be improved.

Here, the content of the natural rubber in the rubber component is not particularly limited, but it is preferably 25% by mass or more, and 35% by mass from the viewpoint of obtaining better adhesion with the rubber member. More preferably, it is more preferably 40% by mass or more. On the other hand, the upper limit of the content of the natural rubber is not particularly limited, but it is preferably 55% by mass or less from the relationship with the content of styrene butadiene rubber described later.
Further, the content of the styrene butadiene rubber in the rubber component is not particularly limited, but it is preferably 45% by mass or more, and 55% by mass or more from the viewpoint of obtaining better processability. Is more preferably 60% by mass or more. On the other hand, the upper limit of the content of the styrene butadiene rubber is not particularly limited, but is preferably 75% by mass or less from the relationship with the content of the natural rubber described above.

The rubber component can be composed only of natural rubber and styrene butadiene rubber, but can also contain rubber other than natural rubber and styrene butadiene rubber as long as the object of the present invention is not impaired.
Other rubbers include, for example, polybutadiene rubber (which refers to a homopolymer (polybutadiene) consisting only of 1,3-butadiene as a monomer, and does not include a co-polymer with other monomers) (BR), synthesis. Synthetic diene rubbers such as isoprene rubber (IR), styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), ethylene propylene diene rubber (EPDM), ethylene propylene rubber (EPM), butyl rubber Synthetic non-diene rubbers such as (IIR).
In addition, about these other rubber | gum, it may be used individually by 1 type and may be used as 2 or more types of blends. Further, among these other rubbers, it is preferable to include at least one selected from synthetic isoprene rubber and polybutadiene rubber.

(Carbon black)
The rubber composition for vibration-proof rubber of the present invention contains at least one carbon black selected from the group consisting of SAF, ISAF, HAF, MAF, FEF, GPF and SRF, in addition to the rubber component described above.
By containing an appropriate amount of a specific type of carbon black in the rubber cement composition, it is possible to adjust viscosity and improve workability while maintaining good dynamic fatigue resistance.

Here, the content of the carbon black is 30 to 65 parts by mass with respect to 100 parts by mass of the rubber component. When the carbon black content is less than 30 parts by mass with respect to 100 parts by mass of the rubber component, the amount of carbon black is too small, so that sufficient dynamic fatigue resistance cannot be obtained. If the black content exceeds 65 parts by mass with respect to 100 parts by mass of the rubber component, the viscosity becomes too high, so that sufficient processability cannot be obtained.
Further, from the viewpoint of obtaining better dynamic fatigue resistance, the lower limit of the content of the carbon black is preferably 35 parts by mass, and 40 parts by mass with respect to 100 parts by mass of the rubber component. Is more preferable. Furthermore, from the viewpoint of obtaining better processability, the upper limit value of the carbon black content is preferably 55 parts by mass, more preferably 50 parts by mass with respect to 100 parts by mass of the rubber component. preferable.

The carbon black is at least one selected from the group consisting of SAF, ISAF, HAF, MAF, FEF, GPF and SRF. This is because both good dynamic fatigue resistance and excellent workability can be achieved.
Further, the carbon black is at least one selected from the group consisting of SAF, ISAF, HAF, MAF and FEF (carbon black A), and at least one selected from the group consisting of FEF, GPF and SRF (carbon Black B) is preferably contained, and the carbon black A and the carbon black B are preferably different.
The carbon black A enhances the reinforcement of the rubber composition and ensures high dynamic fatigue, while the carbon black B can adjust the viscosity of the rubber composition and ensure high processability. At a high level, both dynamic fatigue and workability can be achieved.
In addition, regarding the point that “carbon black A and carbon black B are different”, since FEF carbon black can be included in either carbon black A or carbon black B, the carbon black A Alternatively, when one of the carbon blacks B contains FEF carbon black, the other means that no FEF carbon black is contained.

  Here, the combination of the carbon black A and the carbon black B is not particularly limited. For example, from the viewpoint of achieving both dynamic fatigue and workability at a higher level, a combination of ISAF (carbon black A) and FEF (carbon black B), ISAF (carbon black A) and GPF (carbon black B) ), A combination of HAF (carbon black A) and GPF (carbon black B), or a combination of HAF (carbon black A) and SRF (carbon black B).

  Furthermore, it is more preferable that the mass ratio between the content of the carbon black A and the content of the carbon black B is in the range of 20:80 to 80:20. This is because the processability of the rubber cement composition of the present invention and the adhesion to the rubber member can be achieved at a higher level.

(Organic solvent)
In addition to the rubber component and carbon black described above, the rubber cement composition of the present invention includes an organic solvent having a distillation point at 1013 hPa of 60 to 130 ° C. and containing no toluene.
By using an organic solvent having a distillation point in the range of 60 to 130 ° C. at one atmospheric pressure (1013 hPa), the drying rate of the rubber cement composition of the present invention can be increased and the compatibility with the rubber component is increased. be able to. Moreover, since toluene is not contained as an organic solvent, the burden on the environment can be reduced.
“Toluene-free” means that it does not contain toluene positively, and inevitably a small amount of toluene is included in the scope of the present invention.

  Here, the type of the organic solvent is not particularly limited, and examples thereof include rubber volatile oil, hexane, cyclohexane, petroleum ether, heptane, tetrahydrofuran and the like. Among these, the drying rate of the rubber composition and the rubber component It is preferable to use rubber volatile oil and / or cyclohexane from the viewpoint that the compatibility with can be further improved. In addition, about these organic solvents, 1 type can also be used independently and 2 or more types can also be mixed and used.

As described above, the distillation point of the organic solvent is required to be 60 to 130 ° C. from the point that the drying speed and compatibility with the rubber component can be improved, and for the same reason, 70 to 125 ° C. It is preferable that it is 80-125 degreeC.
In addition, when the organic solvent is a mixture of a plurality of organic solvents (compounds), it is preferable that 95% by mass or more of the organic solvents in the whole organic solvent have a distillation point in the range of 60 to 130 ° C. It is more preferable to have a distillation point in the range of 70 to 125 ° C, and it is more preferable to have a distillation point in the range of 80 to 125 ° C.

  And in the rubber cement composition of this invention, content of the said organic solvent in the mass of the whole rubber cement composition is 70-95 mass%, It is characterized by the above-mentioned. By setting the content of the organic solvent to 70% by mass or more, the solubility of the rubber component can be increased, and the processability of the rubber cement composition can be maintained at a high level. Further, the content of the organic solvent is 95% by mass. By setting it as% or less, the adhesion to the rubber member can be enhanced without inhibiting the vulcanization adhesion between the rubber members. In addition, the lower limit of the content of the organic solvent is preferably 70% by mass, more preferably 75% by mass, and 80% by mass from the viewpoint of realizing better workability. More preferred is 83% by mass. Furthermore, although the upper limit of the content of the organic solvent is determined by the solubility and storage stability of the organic solvent, it is preferably 95% by mass from the viewpoint of realizing better adhesion with the rubber member. 92 mass% is more preferable, and 88 mass% is particularly preferable.

(Other ingredients)
In addition to the rubber component, carbon black, and organic solvent described above, the rubber cement composition of the present invention includes a cobalt-containing compound, a filler other than carbon black, and a vulcanizing agent as long as the object of the present invention is not impaired. , Vulcanization accelerators, vulcanization accelerators, zinc oxide (ZnO), anti-aging agents, antioxidants, foaming agents, oils, lubricants, tackifiers, ultraviolet absorbers and the like.

  It is preferable that the rubber cement composition of the present invention further includes the cobalt-containing compound from the standpoint of realizing better adhesion. By including a cobalt-containing compound in the rubber cement composition, even if the rubber on the surface of the rubber member is peeled off and the metal wire is partially exposed, the rubber member, canvas, steel cord, etc. It is possible to ensure excellent adhesion after vulcanization with the core material.

Here, the type of the cobalt-containing compound is not particularly limited. For example, cobalt salts of organic acids and cobalt salts of inorganic acids, such as cobalt chloride, cobalt sulfate, cobalt nitrate, cobalt phosphate, cobalt chromate and the like. Of these, a cobalt salt of an organic acid is preferably used from the standpoint of obtaining better adhesion. These may be used alone or in combination of two or more.
Examples of the cobalt salt of the organic acid include at least one of cobalt naphthenate, cobalt stearate, cobalt rosinate, cobalt versatate, cobalt tall oil, and the like. It may be a complex salt replaced with.

  Moreover, content of the said cobalt containing compound is 0.1-10 mass parts with respect to 100 mass parts of said rubber components in conversion of cobalt amount, Preferably it is 1-7 mass parts, More preferably, it is 2-5 mass parts. If the amount of cobalt is less than 0.1 parts by weight with respect to 100 parts by weight of the rubber component, sufficient adhesion cannot be improved, while if the amount of cobalt exceeds 1 part by weight, the dynamic resistance after heat aging There is a risk that fatigue will be reduced.

The filler other than the carbon black is not particularly limited, and can be appropriately selected according to required performance and application. For example, it is preferable to further include silica as a filler from the viewpoint of improving physical properties such as wear resistance.
Examples of the silica include wet silica, colloidal silica, calcium silicate, aluminum silicate, and the like.
Among the above, the silica is preferably wet silica, and more preferably precipitated silica. This is because these silicas have high dispersibility and can further improve wear resistance. Precipitated silica is agglomerated primary particles in the initial stage of production by allowing the reaction solution to react in a relatively high temperature, neutral to alkaline pH region to grow silica primary particles and then controlling to the acidic side. It is the silica obtained as a result.

In addition, when blending the silica, the blending amount is preferably 3 to 15 parts by weight, and 5 to 10 parts by weight with respect to 100 parts by weight of the rubber component, from the viewpoint of preventing workability and physical properties from decreasing. More preferably, it is a part.
Furthermore, when the silica is contained in the rubber cement composition, a known silane coupling agent can be added as appropriate, thereby improving dispersibility in the rubber component.

  Examples of the filler other than silica include fillers such as white carbon, fine particle magnesium silicate, heavy calcium carbonate, magnesium carbonate, clay, and talc. The blending amount is about 3 to 25 parts by mass with respect to 100 parts by mass of the rubber component.

  A conventionally well-known thing can be used for the said vulcanizing agent, Although it does not specifically limit, In this invention, sulfur can be used suitably. The content is usually about 0.5 to 5 parts by mass with respect to 100 parts by mass of the rubber component. If the blending amount of the vulcanizing agent is less than 0.5 parts by mass, a sufficient vulcanizing effect may not be obtained, while if it exceeds 5 parts by mass, the elongation, tensile strength, tear resistance, etc. may be reduced. There is a risk of inviting.

  The oil is not necessarily required in the present invention, but can be appropriately added to improve workability. As this oil, conventionally known oils can be used, and are not particularly limited. Specific examples thereof include process oils such as aromatic oils, naphthenic oils and paraffin oils, vegetable oils such as palm oil, and alkylbenzenes. Synthetic oils such as oil can be mentioned, and in use, one kind alone or two or more kinds may be appropriately selected and used. The blending amount of the oil is preferably 0 to 10 parts by mass, particularly 0 to 5 parts by mass with respect to 100 parts by mass of the rubber component. If it exceeds 10 parts by mass, the tensile strength, wear resistance, and tear resistance may be degraded.

  As the vulcanization accelerator, conventionally known ones can be used, and are not particularly limited. For example, CBS (N-cyclohexyl-2-benzothiazylsulfenamide), TBBS (Nt- Sulfenamide vulcanization accelerators such as butyl-2-benzothiazylsulfenamide) and TBSI (Nt-butyl-2-benzothiazylsulfenimide); guanidines such as DPG (diphenylguanidine) And vulcanization accelerators such as tetraoctyl thiuram disulfide and tetrabenzyl thiuram disulfide; and vulcanization accelerators such as zinc dialkyldithiophosphate. The blending amount is about 0.5 to 3 parts by mass with respect to 100 parts by mass of the rubber component.

  In addition, when obtaining the rubber cement composition of the present invention, there is no particular limitation on the blending method of each component described above, and all the component raw materials may be blended and kneaded at one time, or divided into two stages or three stages. The components may be mixed and kneaded. For kneading, a known kneader such as a roll, an internal mixer or a Banbury rotor can be used.

(Method for producing rubber cement composition)

Next, a method for producing the rubber cement composition of the present invention will be described.
The method for producing the rubber cement composition of the present invention is not particularly limited, and each component (rubber component, carbon black, organic solvent and other components) constituting the rubber cement composition is blended and mixed. Can be obtained.

In the method for producing the rubber cement composition of the present invention, the above-mentioned components can be blended and mixed at the same time, or after any of the components are blended and mixed in advance, the remaining components are blended. It is also possible to mix. About these conditions, it can change suitably according to the performance for which a rubber cement composition is requested | required.
For example, the rubber component, the carbon black, and the other components are kneaded from the viewpoint of improving the compatibility between the rubber component and the organic solvent and realizing better processability and adhesion to the rubber member. It is preferable to prepare the rubber composition in advance and then mix and mix the organic solvent.

<Rubber cement composition for conveyor belt>
Moreover, it is preferable that the rubber cement composition of this invention is used for a conveyor belt (it is a rubber cement composition for conveyor belts).
By using the rubber cement composition of the present invention, which is excellent in processability and adhesion to the rubber member, without inhibiting the vulcanization adhesion between the rubber members described above, the conveyor belt after endless processing of the conveyor belt is used. Bondability can be improved.

<Conveyor belt>
The conveyor belt of the present invention is characterized by using the above-described rubber cement composition of the present invention.
By using the rubber cement composition for a conveyor belt according to the present invention in an endless processed part, the bondability of the conveyor belt after endless processing can be improved.

  Further, the rubber cement composition of the present invention can be used for other than the endless processed part. For example, the conveyor belt can be repaired by filling a rubber cement composition in a repaired portion of the conveyor belt (for example, cracks, scratches, holes, etc. generated in the conveyor belt).

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the following examples.

(Examples 1-20, Comparative Examples 1-6)
Samples of rubber cement composition were prepared according to the component composition of Table 1. The following evaluation was performed about the sample of the obtained rubber cement composition.

(Evaluation)
The rubber cement composition of each sample described above was evaluated for (1) handleability, (2) workability, and (3) adhesion after vulcanization.

(1) Handleability (1-1) Solubility of rubber cement composition For each sample of the rubber cement composition, the rubber composition having the composition shown in Table 1 was finely cut and added to the organic solvent shown in Table 1. Then, it produced by expanding sales at 1000 rpm using a homogenizer. Each sample of the obtained rubber cement composition was dipped on a release film, and the dispersion state of each component in the dried film was visually observed. The evaluation of dispersibility is performed according to the following criteria, and the evaluation results are shown in Table 1.
◎ +: Dispersibility is good and mixing time is short ◎: Dispersibility is good ○: Dispersibility is normal ×: Dispersion does not occur

(1-2) Storage stability of rubber cement composition Each sample of the rubber cement composition was allowed to stand in a dark state at room temperature in a sealed state, and the time until settling or gelation was measured. The storage stability was evaluated according to the following criteria, and the evaluation results are shown in Table 1.
○: No sedimentation or gelation over 6 months ×: No sedimentation or gelation within 6 months

(2) Processability (2-1) Ease of application of rubber cement composition Each sample of rubber cement composition with a brush on the surface of the steel cord formed by coating and vulcanizing an arbitrary rubber with a brush. Coated. The evaluation of the ease of coating is performed according to the following criteria, and the evaluation results are shown in Table 1.
◎: Can be applied uniformly ○: Can be applied almost uniformly × -1: Viscosity is too low × -2: Viscosity is too high

(2-2) Drying speed of rubber cement composition For each sample of the rubber cement composition, the time until drying was measured under normal temperature and normal pressure conditions. The evaluation of the drying rate is performed according to the following criteria, and the evaluation results are shown in Table 1.
◎: Dry within 10 minutes ○: Dry within 30 minutes ×: Dry after 30 minutes

(2-3) Tackiness (adhesion)
Arbitrary unvulcanized rubber was bonded to the surface where the rubber was peeled off from the steel cord formed by covering and vulcanizing arbitrary rubber through each sample of the rubber cement composition. Then, it was confirmed whether or not the unvulcanized rubber sheet could be worked without peeling off from the surface of the steel cord during the bonding work. The tackiness is evaluated according to the following criteria, and the evaluation results are shown in Table 1.
A: There is no peeling of the unvulcanized rubber sheet, and the workability is good. B: The peeling of the unvulcanized rubber sheet is small and the work is possible.

(3) Adhesiveness after vulcanization A steel specimen and a rubber composition (unvulcanized) having the composition shown in Table 2 were molded and vulcanized to obtain a primary test specimen. The rubber was peeled off from the test specimen to adjust the pene cord filled with vulcanized rubber, and then the rubber cement composition of each sample was applied. Thereafter, it was molded again with a rubber composition (unvulcanized) having the composition shown in Table 2 and vulcanized to obtain a specimen.

(3-1) Pullout strength The obtained specimens were subjected to a steel cord pullout test in accordance with JIS K 6369 (2000), and the pullout strength (N / mm) was measured.
The measurement results are shown in Table 1. In addition, about the measured drawing force, it shows that adhesiveness is so favorable that a value is large.

(3-2) Dynamic fatigue property About each obtained specimen, the 50% load dynamic fatigue test was implemented based on AS1333 (1994), and the frequency | count (times) until a fracture | rupture was measured.
The measurement results are shown in Table 1. In addition, about the frequency | count to the fracture | rupture measured, it shows that dynamic fatigue property is so favorable that a value is large.

* 1 “Show Black N110” manufactured by Cabot Japan
* 2 "Seast 3" manufactured by Tokai Carbon Co., Ltd.
* 3 "Seast SO" manufactured by Tokai Carbon Co., Ltd.
* 4 "Asahi # 55" manufactured by Asahi Carbon Co., Ltd.
* 5 "Asahi # 50" manufactured by Asahi Carbon Co., Ltd.
* 6 N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine, “NORAC 6C” manufactured by Ouchi Shinsei Chemical Co., Ltd.
* 7 Cobalt stearate * 8 N-tert-butyl-2-benzothiazolylsulfenamide, “Noxeller NS-P” manufactured by Ouchi Shinsei Chemical Co., Ltd.
* 9 Rubber volatile oil (distillation point: 80 to 125 ° C), “LA Rubber Volatile Oil (G)” manufactured by Nippon Oil Corporation
* 10 Cyclohexane (Distillation point: 81 ° C)
* 11 Pentane (Distillation point: 81 ° C)
* 12 Xylene (Distillation point: 138-144 ° C)
* 13 "A / O MIX" manufactured by JX Nippon Oil & Energy Corporation

  From the results in Table 1, all the rubber cement compositions of each example are well balanced with respect to all evaluation items of (1) handleability, (2) workability, and (3) adhesion after vulcanization. It turned out that it shows a result. On the other hand, about the rubber cement composition of each comparative example, it turned out that an inadequate result is shown by any evaluation item.

  According to the present invention, even when toluene is not included as an organic solvent, a rubber cement composition excellent in processability and adhesion to a rubber member is provided without inhibiting vulcanization adhesion between rubber members. it can. Moreover, according to this invention, the conveyor belt excellent in the joining property after an endless process can be provided.

Claims (7)

A rubber component containing natural rubber and styrene butadiene rubber;
30 to 65 parts by mass with respect to 100 parts by mass of the rubber component, at least one carbon black selected from the group consisting of SAF, ISAF, HAF, MAF, FEF, GPF and SRF;
An organic solvent having a distillation point at 1013 hPa of 60 to 130 ° C. and containing no toluene,
A content of the organic solvent is 70 to 95% by mass, a rubber cement composition.   The rubber cement composition according to claim 1, wherein the content of the organic solvent is 80 to 92% by mass.   The carbon black is at least one selected from the group consisting of SAF, ISAF, HAF, MAF and FEF (carbon black A), and at least one selected from the group consisting of FEF, GPF and SRF (carbon black B) The rubber cement composition according to claim 1, wherein the carbon black A and the carbon black B are different from each other.   The rubber cement composition according to claim 3, wherein a mass ratio of the content of the carbon black A and the content of the carbon black B is in a range of 20:80 to 80:20.   The rubber cement composition according to any one of claims 1 to 4, further comprising a cobalt-containing compound.   The rubber cement composition according to claim 1, wherein the rubber cement composition is used for a conveyor belt.   A conveyor belt using the rubber cement composition according to any one of claims 1 to 6.