WO2008041615A1 - Reinforcing code and rubbery product using the same - Google Patents

Abstract

Disclosed is a reinforcing code (12) for reinforcing a rubbery product, which comprises a reinforcing fiber and a coating film provided on the surface of the reinforcing fiber. The coating film is formed by applying an aqueous adhesive agent onto the reinforcing fiber and drying the resulting product. The aqueous adhesive agent comprises at least one rubber latex selected from a carboxyl-modified hydrogenated nitrile rubber and a carboxyl-modified nitrile rubber and a crosslinking agent, and contains a resorcinol-formaldehyde condensate in an amount of 0 to 2 parts by mass relative to 100 parts by mass of the rubber in terms of a mass-based solid content.

Description

 Specification

 Reinforcing cord and rubber product using the same

 Technical field

 The present invention relates to a reinforcing cord for reinforcing a rubber product and a rubber product using the same.

 Background art

 A toothed belt used for driving a camshaft of an automobile internal combustion engine is required to have a high degree of dimensional stability in order to maintain an appropriate timing. In addition, rubber belts used for driving injection pumps and power transmission for industrial machines are required to have strength and elasticity to withstand high loads and high bending. In order to meet these requirements, reinforcing cords containing reinforcing fibers were sometimes embedded in the matrix rubber of these rubber products. Further, for example, as a means for reinforcing the toothed belt, a reinforcing sheet may be further used in addition to the reinforcing cord (see JP-A-2006-144932).

 [0003] Generally, a reinforcing cord is formed by providing a coating film for protecting the surface of the reinforcing fiber on the surface of the reinforcing fiber. For the formation of this coating film, a mixture of resorcin-formaldehyde condensate and latex (hereinafter referred to as RFL, which has a force S) is generally used. In addition, the reinforcing fiber itself is not well-adapted to rubber and has poor adhesion to rubber. For this reason, when the reinforcing fiber is embedded in rubber without processing the surface (without providing a coating film on the surface), the reinforcing fiber does not adhere to the rubber, or the adhesive strength is weak. Because of this, problems such as the fiber and rubber easily peeling off during use were likely to occur.

 [0004] Therefore, in order to improve the adhesion to the matrix rubber and to prevent the deterioration of the quality of the reinforcing fiber, a reinforcing cord in which various coating films are provided on the surface of the reinforcing fiber is proposed. Has been.

[0005] For example, Japanese Patent Application Laid-Open No. 63 270877 discloses a resorcin-formaldehyde condensation as a reinforcing fiber to a glass fiber as a reinforcing cord that achieves good adhesion to rubber. A glass fiber cord having a coating film formed by applying a mixed treatment agent of a product and a latex of hydrogenated nitrile rubber (H—NBR) and drying and curing the mixture is disclosed.

[0006] Japanese Patent Laid-Open No. 11-241275 uses a treatment agent containing resorcin-formaldehyde condensate and rubber latex on the surface of a reinforcing fiber as a reinforcing cord for realizing good adhesion to a predetermined rubber. And a second coating layer formed by using a treatment compound mainly composed of a rubber compound, a crosslinking agent and a maleimide-based crosslinking agent. The code is disclosed.

[0007] In JP-A-1-272876, a rubber layer not containing a thermosetting resin component such as resorcin-formaldehyde condensate is formed as a coating film by treating reinforcing fibers with rubber latex alone. An improved reinforcing cord is disclosed. According to this reinforcing cord, superior flexibility and heat resistance can be realized as compared with the conventional reinforcing cord.

JP-A-2004-183121 discloses a nitrile hydrogenated nitrile rubber and maleimide as a reinforcing cord having good adhesion to a predetermined rubber and high heat resistance and bending fatigue resistance. A reinforcing code in which a coating film is formed using a water-based adhesive containing a crosslinking agent has been proposed.

 [0009] JP 2006 207600 discloses a reinforcing cord in which a coating film is formed using an RFL containing two types of rubber latex as a reinforcing cord that realizes good adhesion to a predetermined rubber. The code is disclosed.

[0010] However, even with the reinforcing cord described in JP-A-63-270877, it was difficult to obtain a satisfactory adhesive force with respect to the current requirements. Further, the reinforcing cord described in Japanese Patent Application Laid-Open No. 11-241275 has a problem that the manufacturing process becomes complicated because two layers of coating layers must be formed, although improvement in adhesion to rubber is observed. there were. Furthermore, in the production of the rubber reinforcing cord disclosed in JP-A-11-241275, a large amount of resorcin-formaldehyde condensate and ammonia are used for forming the first coating layer, and an organic solvent is used for forming the second coating layer. Therefore, environmental measures, especially for workers, which have a large environmental burden, were indispensable. Similarly, the reinforcing cord described in Japanese Patent Application Laid-Open No. 2006-207600 also has a large environmental load because a large amount of resorcin-formaldehyde condensate is used when processing the reinforcing fiber. [0011] The reinforcing cords described in JP-A-1-272876 and JP-A-2004-183121 do not use resorcin-formaldehyde condensate and ammonia! /, But depending on the type of rubber, it is satisfactory. In some cases, a good adhesion performance could not be obtained.

 Disclosure of the invention

 [0012] The present invention has been made paying attention to the above-mentioned problems, and has a better adhesion to rubber and a reinforcing cord having a low environmental load in the coating film forming process. The purpose is to provide Furthermore, another object of the present invention is to provide a rubber product using such a reinforcing cord.

 [0013] The reinforcing cord of the present invention is a reinforcing cord for reinforcing a rubber product, and includes a reinforcing fiber and a coating film provided on the surface of the reinforcing fiber. The coating film is a coating film formed by applying a water-based adhesive to the reinforcing fiber and drying it. The aqueous adhesive contains a latex of at least one rubber selected from carboxyl-modified hydrogenated nitrile rubber and carboxy-modified nitrile rubber, and a crosslinking agent, and resorcinol formaldehyde condensation in the aqueous adhesive The content of the product is 0 to 2 parts by mass with respect to 100 parts by mass of the rubber in terms of a solid mass ratio. In the present specification, the solid content is a general term for the remainder (substance) excluding the solvent and the dispersion medium, and the solid content mass ratio is the mass ratio of the constituent components to the solid content.

 [0014] A rubber product of the present invention is a rubber product including the above-described reinforcing cord of the present invention, and the reinforcing cord is embedded in a rubber composition.

 [0015] According to the reinforcing cord of the present invention, the adhesion to the matrix rubber can be greatly improved as compared with the conventional reinforcing cord. In addition, the water-based adhesive used in the present invention does not contain a large amount of environmental load or substances such as organic solvents, formaldehyde, and ammonia! The ability to improve the working environment in the coating formation process. Furthermore, according to the rubber product of the present invention, even a belt such as a timing belt that requires a high level of heat resistance and bending fatigue resistance can satisfy the requirements. Brief Description of Drawings

FIG. 1 is a perspective view including a partial cross section showing an example of a rubber product including a reinforcing cord of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described in detail.

 [0018] The reinforcing cord of the present invention includes a reinforcing fiber and a covering film provided on the surface of the reinforcing fiber. This coating film is a film formed by applying a water-based adhesive to a reinforcing fiber and drying it.

 [0019] Hereinafter, the reinforcing fiber of the reinforcing cord of the present invention and the aqueous adhesive used for forming the coating film provided on the surface of the reinforcing fiber will be described in detail.

 [0020] The reinforcing fiber used in the reinforcing cord of the present invention is not limited as long as it enhances the shape stability and strength of the rubber product when embedded in the matrix rubber of the rubber product. There is no particular limitation. For example, glass fiber, polybulal alcohol fiber typified by vinylon fiber, polyester fiber, nylon, polyamide fiber such as aramid (aromatic polyamide), carbon fiber or polyparaphenylene benzoxazone fiber can be used. Among these, glass fibers excellent in heat resistance and tensile strength are preferably used.

 [0021] The form of the reinforcing fiber is not particularly limited as long as it can be embedded in the matrix rubber. Examples of the reinforcing fiber include a stable form, a filament form, a cord form, and a rope form.

 [0022] The water-based adhesive contains a rubber latex (hereinafter referred to as rubber latex and a squeezing force S) and a crosslinking agent. The rubber latex used here is

 (A) Latex of carboxyl-modified hydrogenated nitrile rubber

 (B) Latex of carboxyl-modified nitrile rubber

 Force is also at least one of the choices. The water-based adhesive may contain only the rubber latex of either (A) or (B) and may contain both (A) and (B) rubber latices! /, Anyway!

[0023] Examples of the crosslinking agent contained in the water-based adhesive include quinone dioxime-based crosslinking agents such as P-quinonedioxime, methacrylate-based crosslinking agents such as lauryl metatalylate and methyl metatalylate, and DAF (diaryl fumarate). ), DAP (diallyl phthalate), TAC (triallyl cyanurate) and TAIC (triallyl isocyanurate), Examples include maleimide crosslinkers such as maleimide, phenylmaleimide and N, N-m phenylene dimaleimide, aromatic or aliphatic organic diisocyanates, polyisocyanates, aromatic nitroso compounds, or sulfur. These cross-linking agents may be used alone or in combination of two or more. These cross-linking agents are selected in consideration of the rubber latex contained in the water-based adhesive and the type of matrix rubber in which the reinforcing cord is embedded. In addition, it is preferable that these cross-linking agents are made into an aqueous dispersion because they exist uniformly in the aqueous adhesive!

[0024] Among the crosslinking agents exemplified above, it is preferable to use at least one crosslinking agent selected from maleimide crosslinking agents, polyisocyanates, and aromatic nitroso compounds. Among these, maleimide-based crosslinking agents are preferably used. In particular, diphenylmethane 1,4,4 'bismaleimide is highly stable when dispersed in water and has a high crosslinking effect and high heat resistance after crosslinking. Are preferably used. Maleimide crosslinkers, polyisocyanates, and aromatic nitroso compounds combine specifically with the rubber latex (A) and / or (B) above to provide specific adhesion between the reinforcing cord and the matrix rubber. Can be increased. In particular, a combination of a latex of a carboxyl-modified hydrogenated nitrile rubber and a maleimide-based crosslinking agent is preferable because the adhesion can be further improved.

[0025] In addition, a plurality of cross-linking agents may be used from four types of cross-linking agents including maleimide cross-linking agents, polyisocyanates, quinone dioxime cross-linking agents, and aromatic nitroso compounds. In particular, a combination of a maleimide-based crosslinking agent and a polyisocyanate is preferable because higher adhesiveness can be realized.

[0026] If the cross-linking agent contained in the water-based adhesive is too small, the cross-linking between the coating film and the matrix rubber becomes insufficient, and peeling may easily occur at the interface between them. On the other hand, if there are too many crosslinking agents, the amount of rubber latex will be relatively small, so that the strength of the coating film itself will decrease, and as a result, the adhesion between the reinforcing fibers and the matrix rubber will tend to be insufficient There is. For this reason, the content of the crosslinking agent in the water-based adhesive is 5 to 100 parts by mass with respect to 100 parts by mass of rubber (total of carboxyl-modified hydrogenated nitrile rubber and carboxyl-modified nitrile rubber contained in the water-based adhesive). 70 to 50 parts by weight is preferred 15 to 60 parts by weight is more preferred 20 to 50 parts by weight is even more preferred. [0027] In the case of an aqueous adhesive, the resorcinol formaldehyde condensate is not an essential component. If it is 2 parts by mass or less with respect to 100 parts by mass of rubber (total of carboxyl-modified hydrogenated nitrile rubber and carboxyl-modified nitrile rubber contained in the aqueous adhesive) in terms of solid content mass ratio, the aqueous adhesive Contains resorcin formaldehyde condensate! That is, the content of the resorcin formaldehyde condensate in the aqueous adhesive is 0 to 2 parts by mass with respect to 100 parts by mass of the rubber. By adjusting the content of the resorcinol formaldehyde condensate in the aqueous adhesive within this range, the adhesion can be improved. Note that if the content of the resorcin formaldehyde condensate exceeds 2 parts by mass, the adhesiveness is reduced. In addition, by controlling the content of resorcin formaldehyde condensate within this range (0 to 2 parts by mass), while achieving high adhesiveness, the impact on the environment and workers is further suppressed than before. It is possible to produce a reinforcing cord. Considering the impact on the environment and workers, it is desirable that the content of resorcin formaldehyde condensate is low. Therefore, the solid content by mass ratio is preferably 1.5 parts by mass or less, more preferably water based adhesive. Resorcinol Formaldehyde condensate is not included. In addition, if it does not contain resorcin-formaldehyde condensate, it is not necessary to use substances with high environmental impact such as formaldehyde and ammonia, so that environmental measures for workers are not required.

 [0028] Carbon black may be included as a constituent of the coating film. That is, the water-based adhesive may further contain carbon black. By carbonizing carbon black, the manufacturing cost of the reinforcing cord can be reduced, and the adhesion between the reinforcing cord and the matrix rubber can be effectively increased. The content of carbon black in the water-based adhesive is 0 to 50 per 100 parts by weight of the rubber (total of carboxyl-modified hydrogenated nitrile rubber and carboxyl-modified nitrile rubber contained in the water-based adhesive) in terms of solid mass ratio. 0 to 35 parts by weight is more preferred 0 to 35 parts by weight is even more preferred. In addition, it is preferable that the carbon black be an aqueous dispersion because it is homogeneously present in the aqueous adhesive.

[0029] In addition to the rubber latexes (A) and (B) described above, the water-based adhesive includes, for example, butadiene / styrene copolymer latex, dicarboxylated butadiene.styrene copolymer latex. Tas, bullpyridine, butadiene, styrene terpolymer:

 Tas acrylonitrile. Butadiene copolymer May be combined. Also:, some of your own ¾Μ

 [0030] A peroxide may be included as a constituent of the coating film. That is, water-based adhesive

 It may further contain 1S peroxide. By adding the peroxide, the crosslinking between the coating film and the matrix rubber is promoted, so that the adhesion between the reinforcing cord and the matrix rubber can be further enhanced. The type of peroxide used is not limited. For example, organic peroxides such as hydroperoxide and dialkyl peroxide can be used. However, it is necessary to select a peroxide having a reaction rate equivalent to that of the crosslinking agent compounded in the matrix rubber. Further, among these peroxides, water-insoluble ones are preferably used in the form of an aqueous dispersion because they are homogeneously present in the aqueous adhesive. Among various peroxides, cumeneno and id-peroxide used in the following examples (

Cumen Hydrperoxide) is preferable because it is adhesive and water-soluble and has excellent handling properties. The content of peroxide in the water-based adhesive is 0 to 100 parts by weight with respect to 100 parts by weight of rubber (total of carboxyl-modified hydrogenated nitrile rubber and carboxyl-modified nitrile rubber contained in the water-based adhesive). 20 parts by mass is preferred 5 to 15 parts by mass.

 [0031] Examples of the composition (solid content mass ratio) of the water-based adhesive for realizing a reinforcing cord excellent in adhesiveness to the matrix rubber include the following compositions.

[0032] (First example)

 Carboxyl-modified hydrogenated nitrile rubber 100 parts by mass

 : Cross-linking agent 2.5-67.5 J

 Nate 2.5-67.5 Section 5 Peroxide

[0033] (second example) Carboxyl-modified nitrile rubber 100 parts by mass

 Maleimide cross-linking agent 2.5 5-67.5 parts by mass

 Polyisocyanate 2.5 to 67.5 parts by mass

 Carbon black 0-50 parts by mass

 Peroxide 0-20 parts by weight

 Resorcin formaldehyde condensate 0-2 parts by mass

[0034] In the compositions of the first and second examples, the total of the maleimide-based crosslinking agent and the polyisocyanate is 5 to 70 parts by mass.

[0035] In the aqueous adhesive, the above components such as rubber, cross-linking agent and resorcin formaldehyde condensate are dispersed or dissolved in an aqueous solvent. As the aqueous solvent, an aqueous solvent is preferably used since the concentration of the above-mentioned constituent components, which are easy to handle, can be easily controlled, and the environmental load is significantly reduced compared with the organic solvent. In addition, the aqueous solvent contains low-grade alcohol or the like.

 [0036] The water-based adhesive contains other constituents such as an inorganic filler other than carbon black, a plasticizer, an anti-aging agent, a metal oxide, and the like!

 [0037] The method of applying a water-based adhesive to the reinforcing fiber to form a coating film is not particularly limited. Usually, the solvent is removed by immersing the reinforcing fiber in a water tank containing a water-based adhesive, pulling it up and letting the drying furnace dive. Also, the drying conditions for removing the solvent are not particularly limited. For example, the solvent can be removed by exposure to an atmosphere at 80 to 160 ° C for 0.1 to 2 minutes. A reinforcing cord can be produced by collecting a predetermined number of reinforcing fibers having a coating film formed in this manner and twisting the fibers. What is necessary is just to set the number of twists suitable for the number of twists according to the fiber to be used. In addition, the twisting direction may be divided into a plurality of times according to the necessary thickness and specifications of the reinforcing cord, and the twisting direction is not limited. When twisting in two stages, it is advisable to form a cord by bundling several reinforcing fibers and making a twisted strand, and then bundling several strands and twisting the strand.

[0038] In the reinforcing cord formed as described above, the adhesion rate of the coating film is preferably 10 to 30% by mass, and more preferably 12 to 22% by mass. This adhesion rate is less than 10% by mass In this case, it is difficult to cover the entire surface of the reinforcing fiber with a coating film. On the other hand, if the adhesion rate exceeds 30% by mass, the dripping of the aqueous adhesive tends to be a problem in the formation of the coating film. Problems such as different characteristics are likely to occur. The adhesion rate (R) of the coating film refers to the degree of adhesion of the coating film to the mass of the reinforcing fiber such as glass fiber V on the reinforcing cord after drying. It is a mass percentage which shows this, and is given by the following formula.

 R (%) = ((C1 -C0) / C1) X 100

 Dry mass of reinforcing fiber before coating: CO, Dry mass of reinforcing fiber after coating: C1 [0039] Next, the rubber product of the present invention will be described.

 [0040] The rubber product of the present invention includes the reinforcing cord described above, and the reinforcing cord is embedded in a rubber composition (matrix rubber). An example of a rubber product is a toothed belt as shown in FIG. The toothed benolet 1 shown in FIG. 1 includes a belt body 11 and a reinforcing cord 12. The belt main body 11 includes a belt portion 13 and a plurality of tooth portions 14 protruding from the belt portion 13 at regular intervals. The reinforcing cord 12 is arranged and embedded in the belt portion 13 in a direction extending in the circumferential direction (longitudinal direction) of the belt portion 13. The reinforcing cord 12 of the present invention described above is used for the reinforcing cord 12.

 [0041] When manufacturing the rubber product of the present invention, the means for embedding the reinforcing cord in the matrix rubber is not particularly limited, and any known means can be used as it is. The rubber product thus obtained has both high heat resistance derived from the properties of matrix rubber, high strength due to the embedded reinforcing cord, and high bending fatigue resistance. Therefore, this rubber product is particularly suitable for applications such as timing belts for vehicle engines.

The rubber of the rubber composition in which the reinforcing cord of the present invention is embedded is not particularly limited, and chloroprene rubber, chlorosulphonated polyethylene rubber, ethylene propylene rubber, hydrogenated nitrile rubber, or the like may be used. In view of adhesiveness, for example, hydrogenated nitrile rubber and / or hydrogenated nitrile rubber in which a zinc acrylate derivative is finely dispersed are preferably used. In addition, Karuboki Sil-modified hydrogenated nitrile rubber may be included.

 Example

 Hereinafter, the present invention will be described in more detail with reference to examples.

 [0044] (Example;! To 24)

 Three glass fibers (E glass composition, 200 filaments with an average diameter of 9 m were bundled together) were drawn together to obtain 101-tex reinforcing fiber. This reinforcing fiber was immersed in the aqueous adhesives of Examples 1 to 24 having the compositions shown in Tables 1 to 4 below, and then dried in a drying furnace set at 150 ° C. for 1 minute to form a coating film. Formed. The glass fiber on which this coating film is formed is burned down at a rate of 8 times / 10 cm, and 11 further twisted ones are aligned, and the upper twist is applied at a rate of 8 times / 10 cm, The reinforcing cords of Examples 1 to 24 were produced. Examples:! To 24 The reinforcing film adhesion rates of the reinforcing cords were all 20% by mass.

[0045] [Table 1]

Solid content mass ratio (parts by mass)

 Ingredients Examples Examples Examples Examples Examples Examples Examples Examples Examples

 1 2 3 4 5 6 7 8 Carboxyl modified

Hydrogenated nitrile rubber 100 100 100 100 100 100 100 100 Latex (* 1)

Force--Bon Black 25 25 25 25 25 10

 Diphenyl meta

 4,4 '-25 25 25 30 50 Bismaleimide

Frame Polyisocyanate 25 25 30 Kazunori Hashi (* 2)

Agent P-Quinonedi 25

 Kisii

 Aromatic nitroso 25

 Compound

Peroxide

 (Cumen Hydro 10

Par-skilled kiside)

Adhesive strength [N / 25 400 380 340 350 410 480 490 400 Rubber Rubber Rubber Rubber Rubber Rubber Rubber Rubber

 Destruction destruction destruction destruction destruction destruction destruction destruction destruction

(* 1) Z e t p o l L a t e x (manufactured by Zeon Corporation)

(* 2) Elastron (Daiichi Kogyo Seiyaku Co., Ltd.) 2]

Solid content mass ratio (parts by mass) Component Example Example Example

 9 1 0 1 1 1 2 Forced loxyl-modified hydrogenation 100 100 100 100 Nitryl rubber latex (* 1)

Carbon black 25 10

 Diphenylmethane

 -4,4 '-25 25 30 50 Crosslinker Bismaleimide

 Polyisocyanate 25 30

 (2)

Resorcinol 1.5 1.5 1.5 1.5 Formaldehyde condensate

Adhesive strength [N / 25mm] 400 500 500 410 Failure state Rubber destruction Rubber destruction Rubber destruction

(* 1) Ze t p o I La t e x (Nippon Zeon Corporation)

(* 2) Eras Soron (Daiichi Kogyo Seiyaku Co., Ltd.) 3]

Solid content mass ratio (parts by mass)

 Ingredients Examples Examples Examples Examples Examples Examples Examples Examples Examples

 1 3 1 4 1 5 1 6 1 7 1 8 1 9 20 Carboxyl modified

Nitrile rubber latte 100 100 100 100 100 100 100 100 box (* 3)

Rikiichi Bon Black 25 25 25 25 25 10

 Diphenyl meta

 4,4 '― 25 25 25 30 50 Bismaleimide

Frame Polyisocyanate 25 25 30 Kazunori Hashi (* 2)

Agent

 P—Quinonezi 25

 Kisii

 Aromatic nitroso 25

 Compound

Excess S g

 7—Menhydro 10

Parr-a talented boyfriend)

Adhesive strength [N / 25mm] 380 350 320 330 390 460 450 370 Rubber Rubber Rubber Rubber Rubber Rubber Rubber Rubber Destruction state

 Destruction destruction destruction destruction destruction destruction destruction destruction destruction

(* 2) Elastron (Daiichi Kogyo Seiyaku Co., Ltd.)

(* 3) Synthome (Synthome) 4]

Solid content mass ratio (parts by mass)

 Ingredient Example Example Example Example

 2 1 2 2 2 3 24

 Carboxyl modified 100 100 100 100 Nyloryl rubber latex

 (* 3)

 Carbon black 25 10

 Diphenylmethane

 -4,4 'one 25 25 30 50

 Cross-linking agent bismaleimide

 Polyisocyanate 25 30

 卜 (* 2)

 Resorcinol 1.5 1.5 1.5 1.5 Formaldehyde compound

 Adhesive strength CN / 25mm] 390 470 470 380

 Rubber rubber

 Destroyed state

 Destruction destruction destruction destruction

 (* 2) Elastron (Daiichi Kogyo Seiyaku Co., Ltd.)

 (* 3) S y n t h ome r (manufactured by S y n t h ome r)

[0049] (Comparative Example;! ~ 22)

 Comparative Examples 1-22 under the same conditions as Examples 1-24 except that the aqueous adhesives having the compositions shown in Tables 5-8 below were used instead of the aqueous adhesives having the compositions shown in Tables 1-4. A reinforcing cord was prepared.

[0050] [Table 5]

Solid content mass ratio (parts by mass)

 Component Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example

 1 2 3 4 5 6 Nitrile hydride 100 100 100 100 100 100 Rubber latex (* 4)

Car pump rack 25 25 25 25 25

 Diphenylmer

 4 '4'-25 25 30 Bismaleimide

Cross-linking agent Polyisocyanate 25 30

 -卜 （* 2)

 P—Quinonezi 25

 Kisii

 Aromatic bistro 25

 Compound

Peroxide (Cumenhydr 10-peroxide)

Adhesive strength [N / 25nm] 220 200 50 70 230 240 Partial Partial Interfacial Debonding Interfacial Debonding Partial Partial Destructive state

 Rubber destruction Rubber destruction Rubber destruction Rubber destruction

(* 2) Elastron (Daiichi Kogyo Seiyaku Co., Ltd.)

(* 4) Z etp 0 IL atex (Nippon Zeon Corporation) 6]

Solid content ratio (parts by mass)

 Component Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example

 7 8 9 1 0 1 1 1 2 Nitrile 100 100 100 100 100 100 Gold latex (* 5)

Carbon black 25 25 25 25 25

 Diphenylmer

 4, 4 '-25 25 30 Bismaleimide

Cross-linking agent Polyisocyanate 25 30 Ichigo (* 2)

 P—Quinonezi 25

 Kisii

 Aromatic nitroso 25

 Compound

Peroxide (Cumen High 10

Dropper oxide side)

Adhesive strength [N / 25mm] 1 50 100 30 30 150 160

 Partial Partial Interfacial Debonding Interfacial Debonding Partial Partial Destruction

 Rubber destruction Rubber destruction Rubber destruction Rubber destruction

(* 2) Eras Soron (Daiichi Kogyo Seiyaku Co., Ltd.)

(* 5) Nipo IL atex (manufactured by Nippon Zensai Co., Ltd.) 7]

Solid content mass ratio (parts by mass)

 Component Comparative Example Comparative Example Comparative Example Comparative Example Comparative Example

1 3 1 4 1 5 1 6 1 7 Carboxyl-modified hydrogenation 100 100 100 100 100 Nitrile rubber latex (* 1)

Carbon black 25 25 Diphenylmethane 25 25 Crosslinker 1,4'-Bismaleimide

 Aromatic double-mouthed 50 50

 Compound

Peroxide (Kumen Hydro 10 10 10 Par-killed side)

Resorcinol 10 10 10 3 10 Formaldehyde condensate

Adhesive strength [N / 25mm] 80 180 230 260 180 Interfacial debonding Part Part Part Part Destruction state

 Rubber destruction rubber destruction rubber destruction

(* 1) Z etpol Latex (Nippon Zeon Corporation) 8]

Solid content mass ratio (parts by mass) Component Comparative example Comparative example Comparative example Comparative example Comparative example 1 8 1 9 2 0 2 1 2 2 Carboxyl-modified 100 100 100 100 100 Bisole lysole rubber latex (* 3)

 Carbon black 25 25 Diphenylmethane 25 25 -4,4 'One

 Cross-linking agent bismaleimide

 Aromatic nitrosation 50 50

 Compound

 Peroxide (Kumen Hydro 10 10 10 Par-killed side)

 Resorcinol 10 10 10 3 10 Formaldehyde condensate

 Adhesive strength [N / 25mm] 40 80 120 180 90 Interfacial debonding Interfacial debonding Part Partial interfacial debonding Destruction state

 Rubber destruction rubber destruction

(* 3) S y n t h o me r (manufactured by S y n t h o me r)

[0054] The reinforcing cords of Examples 1 to 24 and Comparative Examples 1 to 22 were evaluated for adhesion to rubbers having the compositions shown in Table 9 below. On the rubber sheet (width 25 mm x length 50 mm x thickness 5 mm) having the composition shown in Table 9, along the long side of the reinforcing cord (the fiber direction of the reinforcing cord is almost parallel to the long side of the rubber sheet) ) And heated at 160 ° C. for 20 minutes to bond the reinforcing cord and the rubber sheet to each other to prepare a test piece. Thereafter, the test piece was placed on a tensile tester and pulled in the fiber direction of the reinforcing cord, and the peel strength (adhesive strength) between the rubber sheet and the reinforcing cord was measured. Also, by visually observing the fracture surface of the test piece, the force of `` rubber breakage '' with the rubber of the rubber sheet remaining completely on the reinforcing cord side, or the rubber is not on the reinforcing cord side at all. The power of “interface peeling” that does not remain was confirmed. The results are also shown in Tables 1 to 8 above.

[0055] [Table 9] Ingredients Mass ratio Hydrogenated nitrile rubber (* 6) 70 Hydrogenated nitrile rubber containing zinc dimethacrylate (* 7) 30 Zinc oxide 10 Stearic acid 1 Carbon black 30 卜 Liooctyl limelite 5 Sulfur j | 0.1

1, 3 Bis (t-butyl butyl xyloxy) Benzene 6 Magnesium oxide 1

4, 4-(α, α Dimethylpentyl) Diphenylamine 0.5

2 Mercaptobenzimidazole zinc salt 0.5 卜 Riarylisocyanurate 卜 1

(* 6) Z e t p o l 2020 (manufactured by Nippon Zensai Co., Ltd.)

 (* 7) Z e t p o l 2000 L (manufactured by Nippon Zensai Co., Ltd.)

[0056] As shown in Tables !! to 8, the Examples had higher adhesive strength between the reinforcing cord and the rubber than the Comparative Examples. Specifically, Examples 1 to 24 using a latex of at least one rubber selected from a carboxyl-modified hydrogenated nitrile rubber and a carboxyl-modified nitrile rubber as rubber latex, use these rubber latex! /, N / A, high adhesive strength was obtained as compared with Comparative Examples 1 and 12. In Comparative Examples 13 to 22, although the latex of at least one selected from the carboxyl-modified hydrogenated nitrile rubber and the carboxynole-modified nitrile rubber force is used, the content of the resorcin-formaldehyde condensate (solid content) Since the mass ratio was too large, 3 parts by mass or more, high adhesive strength could not be obtained. Further, when a maleimide-based crosslinking agent was used, higher adhesive force was obtained. Further, examples in which diphenylmethane 4,4, monobismaleimide, which is a maleimide type crosslinking agent, and a polyisocyanate were combined as a crosslinking agent (Examples 6, 7, 10, 11, 18, 19, 22, 22). It was also confirmed that No. 23) was able to obtain even higher adhesion and adhesive strength.

 The power described above with reference to the embodiments of the present invention as described above The present invention is not limited to the above-described embodiments, and can be applied to other embodiments based on the technical idea of the present invention. Industrial applicability

[0058] Since the reinforcing cord of the present invention can realize good adhesion to rubber, Applicable for reinforcing products. For example, it can be suitably used as a reinforcing cord for a timing belt or the like that requires a high level of heat resistance and bending fatigue resistance. In addition, since the rubber product of the present invention can withstand a high load, it can be applied to various uses.

Claims

The scope of the claims

 [1] A reinforcing cord for reinforcing a rubber product,

 A reinforcing film and a coating film provided on a surface of the reinforcing fiber, wherein the coating film is formed by applying an aqueous adhesive to the reinforcing fiber and drying the coating film. And

 The aqueous adhesive contains a latex of at least one rubber selected from carboxyl-modified hydrogenated nitrile rubber and carboxyl-modified nitrile rubber, and a crosslinking agent, and the resorcinol formaldehyde condensate in the aqueous adhesive. The reinforcing cord, whose content is 0 to 2 parts by mass with respect to 100 parts by mass of the rubber in terms of mass ratio of solid content.

 [2] The aqueous adhesive does not contain the resorcin formaldehyde condensate! /,

The reinforcing cord according to 1.

[3] The crosslinking agent is a maleimide crosslinking agent, polyisocyanate, or quinonedioxime crosslinking agent

The reinforcing cord according to claim 1, which is at least one crosslinking agent selected from aromatic nitroso compounds.

 [4] The reinforcing cord according to [3], wherein the aqueous adhesive contains a maleimide-based crosslinking agent and a polyisocyanate as the crosslinking agent.

[5] The composition of the water-based adhesive is a solid mass ratio,

 Carboxyl-modified hydrogenated nitrile rubber 100 parts by mass

 Maleimide cross-linking agent 2.5 5-67.5 parts by mass

 Polyisocyanate 2.5 to 67.5 parts by mass

 Carbon black 0-50 parts by mass

 Peroxide 0-20 parts by weight

 Resorcin formaldehyde condensate 0-2 parts by mass

 The rubber reinforcing cord according to claim 4, wherein the total of the maleimide-based crosslinking agent and the polyisocyanate is 5 to 70 parts by mass.

[6] The composition of the water-based adhesive is a solid mass ratio,

Carboxyl-modified nitrile rubber 100 parts by mass Maleimide cross-linking agent 2.5 5-67.5 parts by mass

 Polyisocyanate 2.5 to 67.5 parts by mass

 Carbon black 0-50 parts by mass

 Peroxide 0-20 parts by weight

 Resorcin formaldehyde condensate 0-2 parts by mass

 The rubber reinforcing cord according to claim 4, wherein the total of the maleimide-based crosslinking agent and the polyisocyanate is 5 to 70 parts by mass.

7. The reinforcing cord according to claim 1, wherein the water-based adhesive further contains carbon black.

 8. The reinforcing cord according to claim 1, wherein the water-based adhesive further contains a peroxide.

[9] A rubber product comprising the reinforcing cord according to claim 1,

 A rubber product in which the reinforcing cord is embedded in a rubber composition.