JP6018546B2 - Manufacturing method of rubber composite - Google Patents

Description

  The present invention relates to a method for producing a rubber composite and a rubber composite, and more specifically, at least one of a coating agent containing a composition suitable for adhering to the surface of a rubber article and a coating sheet comprising the coating agent are used. The present invention also relates to a method for producing a rubber composite comprising the coating body and the rubber article, and a rubber composite obtained using the production method.

Conventionally, coating bodies having good adhesion to rubber articles such as tires have been demanded, but there has been no material capable of obtaining sufficient adhesion. As a method for closely attaching a vulcanized rubber article, for example, Patent Document 1 uses an aqueous dispersion containing a 1,2-polybutadiene hydroxyl group-containing material, a liquid polybutadiene isocyanate compound, and a polyolefin resin as a surface treatment agent for vulcanized rubber. It is disclosed.
Patent Document 2 proposes a polymer tire coating produced from an aqueous emulsion containing at least a crosslinkable polymer base, a vulcanizing agent, and a specific surfactant.
Further, Patent Document 3 discloses a first layer forming step in which an ultraviolet curable thermoplastic elastomer is applied to the side surface of a tire, and the applied ultraviolet curable thermoplastic elastomer is irradiated with ultraviolet rays to form a cured layer. A lamination step of applying an ultraviolet curable thermoplastic elastomer on the formed cured layer, and irradiating the applied ultraviolet curable thermoplastic elastomer with ultraviolet rays to laminate the cured layer, There is disclosed a method for decorating a tire side surface, which is characterized by forming a decoration made of a laminate of the cured layers.

JP-A-3-252442 JP 2013-505348 A JP 2013-10295 A

However, since the method described in Patent Document 1 uses a polyurethane-based surface treatment agent, it is not in close contact with the rubber article by covalent bonding, and its adhesion to the rubber article is low.
In addition, the method described in Patent Document 2 sprays or brushes a polymer tire coating produced from an aqueous emulsion containing a specific surfactant on a rubber article such as a tire. It was unsuitable for forming a coating body on the part, and did not impart decorating properties.
And the method of patent document 3 repeats the process of irradiating ultraviolet-ray-curable thermoplastic elastomers, such as an oligomer having a (meth) acryloyl group, with ultraviolet rays to form a cured layer. It was such a thing.
Accordingly, the present invention provides a coating body and a rubber article, which can be easily attached to a rubber article without taking time and can provide a decorative property using a coating agent that can adhere strongly. It is an object of the present invention to provide a rubber composite production method and a rubber composite obtained by the method.

  The present inventors use a coating agent containing a composition comprising a polythiol compound (A), an isocyanate group-containing compound (B), and a radical generator (C) in a specific ratio, and the coating agent. It has been found that the problem of the present invention can be solved by applying at least one of heating and light irradiation using at least one type of coating sheet, and has completed the present invention.

That is, the present invention
[1] The isocyanate group with respect to the total number of moles of thiol groups contained in the polythiol compound (A), comprising the polythiol compound (A), the isocyanate group-containing compound (B), and the radical generator (C). At least a part of the surface of the rubber article is coated with a coating agent containing a composition in which the ratio of the total number of moles of isocyanate groups contained in the compound (B) (isocyanate groups / thiol groups) is 0.20 or more and 0.80 or less. A method for producing a rubber composite comprising the coating body and the rubber article, wherein the coating body is made to be a coating body by applying at least one of heating and light irradiation to the coating agent.
[2] Polyisocyanate compound (A), isocyanate group-containing compound (B), and radical generator (C) are blended, and the isocyanate group with respect to the total number of moles of thiol groups contained in the polythiol compound (A) Forming a coating sheet comprising a coating agent comprising a composition having a total molar ratio of isocyanate groups (isocyanate groups / thiol groups) contained in the containing compound (B) of 0.20 or more and 0.80 or less, After the coating sheet is attached to at least a part of the surface of the rubber article, at least one of heating and light irradiation is applied to the coating sheet to obtain a coating body, and the coating body and the rubber article A method for producing a rubber composite,
[3] The method for producing a rubber composite according to [1], wherein the coating agent is applied to and adhered to at least a part of the surface of the rubber article.
[4] The coating sheet according to [2], wherein after forming the coating sheet, the coating sheet is left in the air at 0 to 60 ° C. for 1 minute or longer, and then the coating sheet is attached to at least a part of the surface of the rubber article. Production method of rubber composite,
[5] The radical generator (C) contains a photo radical generator, and the ratio of the total number of moles of the photo radical generator to the total number of moles of thiol groups contained in the polythiol compound (A) (photo radical generation Agent / thiol group) is 0.0005 or more, and the method for producing a rubber composite according to any one of the above [1] to [4],
[6] The ratio of the total number of moles of the thermal radical generator to the total number of moles of thiol groups contained in the polythiol compound (A) (the thermal radical generator) Agent / thiol group) is 0.025 or more, and the method for producing a rubber composite according to any one of the above [1] to [4],
[7] The radical generator (C) includes a photo radical generator and a thermal radical generator, and the total of the radical generator (C) with respect to the total number of moles of thiol groups contained in the polythiol compound (A). The method for producing a rubber composite according to any one of the above [1] to [4], wherein the molar ratio (radical generator (C) / thiol group) is 0.025 or more, and [8] the rubber article The method for producing a rubber composite according to any one of the above [1] to [7], wherein is a vulcanized rubber article ,
Is to provide.

According to the present invention, from a coating body and a rubber article that can be easily attached to a rubber article without taking time and that can impart decorating properties using a coating agent that can adhere strongly. The rubber composite manufacturing method and the rubber composite obtained by the method can be obtained.
In the present invention, since a transparent coating agent can be obtained, adhesion to a rubber article can be effectively imparted by light irradiation. Moreover, since a coating agent can be prepared without using an organic solvent, the effect that an environmental load is not applied can also be show | played.

In the present specification, it is possible to arbitrarily adopt the rules that are preferable, and it can be said that the combinations of the rules that are preferable are more preferable.
"Production method of rubber composite"
The first aspect of the present invention comprises a polythiol compound (A), an isocyanate group-containing compound (B), and a radical generator (C). The total moles of thiol groups contained in the polythiol compound (A). A rubber article comprising a coating agent containing a composition having a ratio of the total number of moles of isocyanate groups contained in the isocyanate group-containing compound (B) to the number (isocyanate groups / thiol groups) of 0.20 or more and 0.80 or less A rubber composite comprising the coating body and the rubber article, wherein the coating body is made to be a coating body by applying at least one of heating and light irradiation to the coating agent after adhering to at least a part of the surface of the rubber composite. It is a manufacturing method, The 2nd aspect of this invention is a polythiol compound (A), an isocyanate group containing compound (B), and a radio The ratio of the total number of moles of isocyanate groups contained in the isocyanate group-containing compound (B) to the total number of moles of thiol groups contained in the polythiol compound (A) (isocyanate group) / Thiol group) is formed from a coating agent containing a composition (hereinafter sometimes referred to as “coating composition”) having a value of 0.20 or more and 0.80 or less, and the coating sheet is a rubber article. A rubber composite consisting of the coating body and the rubber article, wherein the coating body is made to be a coating body by applying at least one of heating and light irradiation to the coating sheet after being attached to at least a part of the surface of the rubber composite. It is a manufacturing method.
First, the coating composition used in the production method of the present invention and the components of the coating agent containing the coating composition will be described below.

[Coating composition]
The coating composition used in the present invention comprises a polythiol compound (A), an isocyanate group-containing compound (B), and a radical generator (C), and the thiol group contained in the blended polythiol compound (A). The ratio (isocyanate group / thiol group) of the total number of isocyanate groups contained in the isocyanate group-containing compound (B) to be blended with respect to the total number of moles is 0.20 or more and 0.80 or less. .
When the molar ratio (isocyanate group / thiol group) is 0.20 or more, the coating composition is sufficiently hardened and the cohesive force of the coating body is increased. In addition, if the molar ratio (isocyanate group / thiol group) is 0.80 or less, the thiol group has a sufficient abundance, for example, between the thiol group and the carbon-carbon double bond of the rubber article. The thiol-ene reaction is sufficiently performed in the above, so that the coating composition can be firmly adhered to the rubber article, and the adhesion strength is high. Therefore, the ratio (isocyanate group / thiol group) is preferably 0.30 or more, more preferably 0.70 or less, and further preferably 0.40 to 0.60.
Here, the total number of moles of thiol groups contained in the blended polythiol compound (A) is obtained by multiplying the number of moles of the blended polythiol compound (A) by the number of thiol groups possessed by one molecule of the polythiol compound (A). Can be calculated.
Moreover, the total mole number of the isocyanate group contained in the isocyanate group containing compound (B) mix | blended can be measured by JISK1603-1: 2007B method.
Furthermore, the ratio of the number of moles (isocyanate group / thiol group) is the polythiol compound blended with the total number of moles of isocyanate groups contained in the blended isocyanate group-containing compound (B) obtained as described above. It can be determined by dividing by the total number of moles of thiol groups contained in (A).

According to the coating composition, not only unvulcanized rubber but also vulcanized rubber can be easily and strongly adhered. The reason is estimated as follows.
It is considered that the coating composition is firmly cured by causing a urethanization reaction between a part of the polythiol compound (A) and the isocyanate group-containing compound (B). Further, it is considered that another part of the polythiol compound (A) reacts with the radical generator (C) to generate a thiyl radical, and this thiyl radical reacts with a carbon-carbon double bond present in the rubber. It is considered that the coating composition strongly adheres to the rubber by chemically bonding the coating composition to the rubber by such a thiol-ene reaction. In particular, since carbon-carbon double bonds exist not only in unvulcanized rubber but also in vulcanized rubber, it is considered that the rubber, particularly vulcanized rubber, can be strongly adhered according to the coating composition of the present invention. It is done.
Further, it is considered that the sulfur atom of the thiol group of the polythiol compound (A) and the carbon atom of the carbon-carbon bond are chemically bonded by a hydrogen abstraction reaction from the carbon-carbon bond main chain existing in the rubber. Therefore, it is not always necessary to have a carbon-carbon double bond in the rubber.
In the present specification, the polythiol compound (A), the isocyanate group-containing compound (B), the radical generator (C), the urethanization catalyst (D) and the surface conditioner (E) are respectively added to the component (A), It may be called a component (B), a component (C), a component (D), and a component (E).

<Polythiol compound (A)>
In the present invention, the polythiol compound (A) refers to a compound having two or more thiol groups in one molecule.
Although there is no restriction | limiting in particular in a polythiol compound (A), From a viewpoint of improving adhesiveness, what has 2-6 thiol groups in 1 molecule is preferable.
In addition, the polythiol compound (A) includes primary, secondary and tertiary compounds, but the primary is more preferable from the viewpoint of improving adhesion.
The molecular weight of the polythiol compound (A) is preferably 3000 or less, more preferably 2000 or less, still more preferably 1000 or less, and still more preferably 900 or less, from the viewpoint of improving adhesion. More preferably, it is 800 or less. In addition, when a polythiol compound (A) is a polymer, molecular weight means the number average molecular weight of standard polystyrene conversion.

Examples of the polythiol compound (A) include aliphatic polythiols that may contain heteroatoms and aromatic polythiols that may contain heteroatoms. From the viewpoint of improving adhesion, the polythiol compound (A) may contain heteroatoms. Good aliphatic polythiols are preferred.
Here, the aliphatic polythiol which may contain a hetero atom refers to an aliphatic compound which may contain a hetero atom having two or more thiol groups in one molecule. Moreover, the aromatic polythiol which may contain the hetero atom means the aromatic compound which may contain the hetero atom which has two or more thiol groups in 1 molecule.
The hetero atom is preferably at least one selected from oxygen, nitrogen, sulfur, phosphorus, halogen atom, and silicon, more preferably oxygen, nitrogen, sulfur, phosphorus, and halogen atoms from the viewpoint of improving adhesion. It is at least one selected, and more preferably at least one selected from oxygen, nitrogen and sulfur.

Examples of the aliphatic polythiol that may contain a hetero atom include, for example, a polythiol other than a thiol group, such as an alkanedithiol having 2 to 20 carbon atoms, and a halogen atom of a halohydrin adduct of alcohol. Thioglycolic acid ester obtained by esterification of polythiol substituted with thiol group, polythiol composed of hydrogen sulfide reaction product of polyepoxide compound, polyhydric alcohol having 2-6 hydroxyl groups in the molecule and thioglycolic acid Contains a mercapto fatty acid esterified product obtained by esterification of a polyhydric alcohol having 2 to 6 hydroxyl groups in the molecule and a mercapto fatty acid, a thiol isocyanurate compound obtained by reacting an isocyanurate compound and a thiol, and a polysulfide group Thiol Silicones modified with thiol groups, silsesquioxane or the like which is modified with a thiol group.
The polyhydric alcohols having 2 to 6 hydroxyl groups in the molecule include alkanediol having 2 to 20 carbon atoms, poly (oxyalkylene) glycol, glycerol, diglycerol, trimethylolpropane, ditrimethylolpropane, Examples include pentaerythritol and dipentaerythritol.

  Among these, from the viewpoint of improving the adhesion, polythiol other than thiol group is aliphatic hydrocarbon, polythiol obtained by substituting halogen atom of alcohol halohydrin adduct with thiol group, hydrogen sulfide of polyepoxide compound A polythiol, a thioglycolic acid ester, a mercapto fatty acid ester, and a thiol isocyanurate compound are more preferable, a mercapto fatty acid ester and a thiol isocyanurate compound are more preferable, and a mercapto fatty acid ester is more preferable. From the same viewpoint, a thiol containing no polysulfide group or siloxane bond is more preferable.

(Polythiol whose part other than thiol group is aliphatic hydrocarbon)
Examples of the polythiol in which the portion other than the thiol group is an aliphatic hydrocarbon include alkanedithiol having 2 to 20 carbon atoms.
Examples of the alkanedithiol having 2 to 20 carbon atoms include 1,2-ethanedithiol, 1,1-propanedithiol, 1,2-propanedithiol, 1,3-propanedithiol, 2,2-propanedithiol, 1,4 -Butanedithiol, 2,3-butanedithiol, 1,5-pentanedithiol, 1,6-hexanedithiol, 1,8-octanedithiol, 1,10-decanedithiol, 1,1-cyclohexanedithiol, 1,2- And cyclohexanedithiol.

(Thioglycolic acid ester)
Examples of the thioglycolic acid ester include 1,4-butanediol bisthioglycolate, 1,6-hexanediol bisthioglycolate, trimethylolpropane tristhioglycolate, pentaerythritol tetrakisthioglycolate, and the like.

(Mercapto fatty acid esterified product)
The mercapto fatty acid ester is preferably a mercapto fatty acid ester having a primary thiol group from the viewpoint of improving adhesion, and a β-mercaptopropionic acid ester of a polyhydric alcohol having 2 to 6 hydroxyl groups in the molecule. The compound is more preferred. In addition, the mercapto fatty acid ester having a primary thiol group preferably has 4 to 6 thiol groups in one molecule from the viewpoint of improving adhesion, and is 4 or 5. Is more preferable and four is still more preferable.

As the β-mercaptopropionate esterified product having a primary thiol group, tetraethylene glycol bis (3-mercaptopropionate) (EGMP-4), trimethylolpropane tris (3-mercaptopropio) is preferable. Nate) (TMMP), pentaerythritol tetrakis (3-mercaptopropionate) (PEMP), and dipentaerythritol hexakis (3-mercaptopropionate) (DPMP). Among these, PEMP and DPMP are preferable, and PEMP is more preferable.
In addition, PEMP can be obtained as [manufactured by SC Organic Chemical Co., Ltd., trade name “PEMP”, four thiol groups], and DPMP as [manufactured by SC Organic Chemical Co., Ltd., trade name “DPMP”, six thiol groups]. .

  Examples of the β-mercaptopropionic acid esterified product having a secondary thiol group include esterified products of polyhydric alcohols having 2 to 6 hydroxyl groups in the molecule and β-mercaptobutanoic acid. Examples thereof include 1,4-bis (3-mercaptobutyryloxy) butane, pentaerythritol tetrakis (3-mercaptobutyrate) and the like.

(Thiol isocyanurate compound)
As a thiol isocyanurate compound obtained by reacting an isocyanurate compound and a thiol, a thiol isocyanurate compound having a primary thiol group is preferable from the viewpoint of improving adhesion. Moreover, as a thiol isocyanurate compound having a primary thiol group, the number of thiol groups in one molecule is preferably 2 to 4 and more preferably 3 from the viewpoint of improving adhesion. preferable.
As the thiol isocyanurate compound having the primary thiol group, tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate (TEMPIC) is preferable.

(Silicone modified with thiol group)
Examples of silicones modified with a thiol group include trade names KF-2001, KF-2004, X-22-167B (Shin-Etsu Chemical), SMS042, SMS022 (Gelest), PS849, PS850 (UCT). .

(Aromatic polythiol)
Aromatic polythiols include 1,2-dimercaptobenzene, 1,3-dimercaptobenzene, 1,4-dimercaptobenzene, 1,2-bis (mercaptomethyl) benzene, 1,3-bis (mercaptomethyl) Benzene, 1,4-bis (mercaptomethyl) benzene, 1,2-bis (mercaptoethyl) benzene, 1,3-bis (mercaptoethyl) benzene, 1,4-bis (mercaptoethyl) benzene, 1,2, 3-trimercaptobenzene, 1,2,4-trimercaptobenzene, 1,3,5-trimercaptobenzene, 1,2,3-tris (mercaptomethyl) benzene, 1,2,4-tris (mercaptomethyl) Benzene, 1,3,5-tris (mercaptomethyl) benzene, 1,2,3-tris (mercaptoethyl) benzene, 1,2,4-tris (Mercaptoethyl) benzene, 1,3,5-tris (mercaptoethyl) benzene, 2,5-toluenedithiol, 3,4-toluenedithiol, 1,3-di (p-methoxyphenyl) propane-2,2- Examples include dithiol, 1,3-diphenylpropane-2,2-dithiol, phenylmethane-1,1-dithiol, 2,4-di (p-mercaptophenyl) pentane.

<Isocyanate group-containing compound (B)>
Examples of the isocyanate group-containing compound (B) include aromatic, aliphatic and alicyclic diisocyanates, and modified products thereof.

  Examples of aromatic, aliphatic and alicyclic diisocyanates include tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), xylylene diisocyanate (XDI), naphthylene diisocyanate (NDI), phenylene diisocyanate (PPDI), m. -Tetramethylxylylene diisocyanate (TMXDI), methylcyclohexane diisocyanate (hydrogenated TDI), dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexane diisocyanate (hydrogenated PPDI), bis (isocyanatomethyl) cyclohexane (Hydrogenated XDI), norbornene diisocyanate (NBDI), isophorone diisocyanate (IPDI), hexamethylene diisocyanate (HDI), butanediiso Aneto, hexamethylene diisocyanate 2,2,4-trimethyl hexamethylene diisocyanate to 2,4,4-trimethyl like.

  When the blended polythiol compound (A) is a mercapto fatty acid ester and a thiol isocyanurate compound, the blended isocyanate group-containing compound (B) is hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), tri One or more of diisocyanate (TDI), xylylene diisocyanate (XDI), and diphenylmethane diisocyanate (MDI) are preferred. Among these, hexamethylene diisocyanate (HDI), isophorone diisocyanate (IPDI), xylylene diisocyanate (XDI), bis (isocyanatomethyl) cyclohexane (hydrogenated XDI) and tolylene diisocyanate (TDI). 1 type or 2 types or more are more preferable.

  In addition, as modified products of aromatic, aliphatic and alicyclic diisocyanates, TMP (trimethylolpropane) adduct modified products obtained by reaction of trimethylolpropane and isocyanate, isocyanurate obtained by trimerization of isocyanate Type modified products, burette modified products obtained by reaction of urea and isocyanate, allophanate modified products obtained by reaction of urethane and isocyanate, prepolymers obtained by reaction with polyol, etc. Can be used.

In addition, as a TMP adduct type modified body, an isocyanurate type modified body, a burette type modified body, and an allophanate modified body, the following modified body is preferable from a viewpoint of an adhesive improvement.
That is, as the TMP adduct type modified product, a TMP adduct type modified product obtained by the reaction of TMP and TDI, a TMP adduct type modified product obtained by the reaction of TMP and XDI, and a reaction of TMP and hydrogenated XDI are obtained. TMP adduct-type modified product, TMP adduct-type modified product obtained by reaction of TMP and IPDI, TMP adduct-type modified product obtained by reaction of TMP and HDI, and TMP adduct type obtained by reaction of TMP and MDI A modified product is preferred.
Further, the isocyanurate-type modified product is an isocyanurate-type modified product obtained by trimming HDI, an isocyanurate-type modified product obtained by trimming IPDI, an isocyanurate-type modified product obtained by trimming TDI, and An isocyanurate type modified product obtained by trimerization of hydrogenated XDI is preferred.
Moreover, as a burette type modified body, the burette type modified body obtained by reaction of urea and HDI is preferable.
Moreover, as an allophanate type modified body, the allophanate type modified body obtained by reaction of urethane and IPDI is preferable.

Specific examples of the isocyanate group-containing compound (B) include HDI burette-modified isocyanate [manufactured by Sumitomo Bayer Urethane Co., Ltd., trade name “Desmodur N3200”, two isocyanate groups], HDI isocyanurate-modified isocyanate [Japan Made by Polyurethane Industry Co., Ltd., trade name “Coronate HXLV”, 2 isocyanate groups], IPDI isocyanurate-modified isocyanate [manufactured by Sumika Bayer Urethane Co., Ltd., trade name “Desmodur Z4470BA”, 2 isocyanate groups] IPDI allophanate modified isocyanate [manufactured by Sumika Bayer Urethane Co., Ltd., trade name “Desmodur XP2565”, 2 isocyanate groups], TDI TMP adduct modified isocyanate [manufactured by Sumika Bayer Urethane Co., Ltd., trade name “Desmodur” L75 (C) ", 2 isocyanate groups], TDI isocyanurate-modified isocyanate [Mitsui Chemical Polyurethanes Co., Ltd., trade name" D-204 ", 2 isocyanate groups], XDI TMP adduct-modified isocyanate [Mitsui Chemicals Product name “D-110N” manufactured by Polyurethane Co., Ltd., 2 isocyanate groups], H ₆ XDI TMP adduct-modified isocyanate [product name “D-120N” manufactured by Mitsui Chemicals Polyurethanes Co., Ltd., 2 isocyanate groups] , H ₆ XDI isocyanurate-modified isocyanate [Mitsui Chemical Polyurethanes Co., Ltd., trade name “D-127N”, 2 isocyanate groups], IPDI [Evonik Degussa Japan Co., Ltd., trade name “VESTANAT IPDI”, isocyanate 2 groups, functional group equivalent 111] and the like.

The polythiol compound (A) used in combination with at least one of the above-mentioned TMP adduct type modified product, isocyanurate type modified product, burette type modified product and allophanate modified product preferably has a primary thiol group. It is 1 type or 2 types of the thiol isocyanurate compound which has (beta) -mercaptopropionic ester and the primary thiol group.
Here, the β-mercaptopropionate esterified product having a primary thiol group is preferably pentaerythritol tetrakis (3-mercaptopropionate) (PEMP) and dipentaerythritol hexakis (3-mercaptopropionate). It is at least one of (DPMP). The thiol isocyanurate compound having a primary thiol group is preferably a thiol isocyanurate compound having a primary thiol group having 3 thiol groups in one molecule, more preferably tris. -[(3-mercaptopropionyloxy) -ethyl] -isocyanurate (TEMPIC) [manufactured by SC Organic Chemical Co., Ltd., trade name “TEMPIC”, three thiol groups].

<Radical generator (C)>
As the radical generator (C), at least one of a thermal radical generator and a photo radical generator can be used. Among these, the photo radical generator can be used in the same manner as the thermal radical generator from the viewpoint of attaching the coating agent containing the coating composition to at least a part of the surface of the rubber article. Further, from the viewpoint of further improving the adhesion to the rubber article, a thermal radical generator is preferable, a thermal radical generator composed of a peroxide is more preferable, and a thermal radical generator composed of an organic peroxide is still more preferable.
A radical generator (C) can also be used individually by 1 type or in combination of 2 or more types.

As the photoradical generator, known ones can be widely used and are not particularly limited.
For example, an intramolecular cleavage type photo radical generator may be mentioned, and benzoin alkyl ether photo radical generators such as benzoin ethyl ether, benzoin isobutyl ether and benzoin isopropyl ether; 2,2-diethoxyacetophenone, 4′-phenoxy-2 Acetophenone photoradical generators such as 2-dichloroacetophenone, 2-hydroxy-2-methylpropiophenone, 4′-isopropyl-2-hydroxy-2-methylpropiophenone, 4′-dodecyl-2-hydroxy- Propiophenone photoradical generators such as 2-methylpropiophenone; anthraquinone photoradical generators such as benzyldimethyl ketal, 1-hydroxycyclohexyl phenyl ketone and 2-ethylanthraquinone, 2-chloroanthraquinone; , 4,6-trimethyl benzoyl - diphenyl - phosphine oxide, bis (2,4,6-trimethylbenzoyl) - acylphosphine oxide-based photoradical generating agents such as triphenylphosphine oxide.

Other hydrogen abstraction type photo radical generators include benzophenone / amine photo radical generator, Michler ketone / benzophenone photo radical generator, thioxanthone / amine photo radical generator, and the like. In order to avoid migration of the unreacted photoradical generator, a non-extractable photoradical generator can be used. For example, there are those obtained by polymerizing an acetophenone radical generator and those obtained by adding a double bond of an acrylic group to benzophenone.
These photo radical generators can be used alone or in combination of two or more.

  Examples of the thermal radical generator composed of an organic peroxide include t-butyl-2-ethylperoxyhexanoate, dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexa. Noate, 1,1-di (t-hexylperoxy) cyclohexanone, di-t-butyl peroxide, t-butylcumyl peroxide, 1,1-di (t-hexylperoxy) -3,3,5 -Trimethylcyclohexane, t-amylperoxy-2-ethylhexanoate, di (2-t-butylperoxyisopropyl) benzene, di (t-butyl) peroxide, benzoyl peroxide 1,1'-di (2 -T-butylperoxyisopropyl) benzene, benzoyl peroxide, 1,1'-di (t-butylperoxy) cyclohexane, di (3,5,5-trimethylhexanoyl) peroxide, t-butylperoxyneodecanoate, t-hexylperoxyneodecanoate, dicumyl peroxide and the like. Among these, preferably t-butyl-2-ethylperoxyhexanoate, dilauroyl peroxide, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1,1-di It is at least one of (t-hexylperoxy) cyclohexanone, di-t-butyl peroxide, and t-butylcumyl peroxide. The thermal radical generator composed of an organic peroxide can be used alone or in combination of two or more.

  Redox generation consisting of a combination of oxidizing agent and reducing agent such as a combination of hydrogen peroxide and iron (II) salt, a combination of persulfate and sodium bisulfite, etc. Agents. The thermal radical generator composed of an inorganic oxide can be used alone or in combination of two or more.

<Optional component>
The coating composition according to the present invention may further contain optional components. Optional components include urethanization catalysts, surface conditioners, solvents, binders, fillers, pigment dispersants, conductivity imparting agents, UV absorbers, antioxidants, anti-drying agents, penetrants, pH adjusters, metal sequestering agents. , Fungicides, fungicides, surfactants, plasticizers, waxes, leveling agents and the like.

(Urethane catalyst (D))
Any urethanization catalyst can be used as the urethanization catalyst (D). Examples of the catalyst for urethanization reaction include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin thiocarboxylate, dibutyltin dimaleate, dioctyltin thiocarboxylate, tin octenoate, monobutyltin oxide and the like; stannous chloride, etc. Inorganic lead compounds; organic lead compounds such as lead octenoate; bis (2-dimethylaminoethyl) ether, N, N, N ′, N′-tetramethylhexamethylenediamine, triethylenediamine (TEDA), benzyldimethylamine, Amines such as 2,2′-dimorpholinoethyl ether and N-methylmorpholine; organic sulfonic acids such as p-toluenesulfonic acid, methanesulfonic acid and fluorosulfuric acid; inorganic acids such as sulfuric acid, phosphoric acid and perchloric acid Sodium alcoholate, lithium hydroxide Aluminum alcoholates, bases such as sodium hydroxide; tetrabutyl titanate, tetraethyl titanate, titanium compounds such as tetraisopropyl titanate; bismuth compounds; quaternary ammonium salts, and the like. Among these, the above amines are preferable, and triethylenediamine (TEDA) is more preferable. These catalysts may be used alone or in combination of two or more.
It is preferable that 0.0001-0.1 mass% of urethanization catalysts (D) are contained in a coating agent.

(Surface conditioner (E))
Any surface conditioning agent can be used as the surface conditioning agent (E). Examples of the surface conditioner include acrylic, vinyl, silicone, and fluorine. Among these, a silicone type is preferable from the viewpoint of compatibility and surface tension reducing ability.
It is preferable that 0.001-10 mass% of surface conditioning agents (E) are contained in a coating agent.

(solvent)
The solvent is not particularly limited as long as it does not react with other compounding components, and examples thereof include aromatic solvents and aliphatic solvents.
Specific examples of the aromatic solvent include toluene, xylene and the like. Hexane etc. are mentioned as an aliphatic solvent.

<Amount of each component>
The ratio of the total number of moles of the radical generator (C) to be blended to the total number of moles of thiol groups contained in the blended polythiol compound (A) (radical generator (C) / thiol group) is 0.025. The above is preferable. Thereby, adhesiveness improves. From this viewpoint, the ratio (radical generator (C) / thiol group) is preferably 0.03 or more, more preferably 0.035 or more, and further preferably 0.04 or more. From the viewpoint of improving adhesion, the ratio (radical generator (C) / thiol group) is preferably 0.5 or less, more preferably 0.45 or less, and still more preferably 0.4. It is as follows.

  When the radical generator (C) contains a photoradical generator, the ratio of the total number of moles of the photoradical generator to the total number of moles of thiol groups contained in the polythiol compound (A) (photoradical generation (Agent / thiol group) is preferably 0.0005 or more. Thereby, adhesiveness improves. From this viewpoint, the ratio (photo radical generator / thiol group) is more preferably 0.001 or more, and further preferably 0.005 or more. Moreover, since an excessive photoradical generator causes high cost, it is preferably 0.2 or less, more preferably 0.1 or less, and further preferably 0.05 or less from the viewpoint of economy. It is.

  When the radical generator (C) contains a thermal radical generator, the ratio of the total number of moles of the thermal radical generator to the total number of moles of thiol groups contained in the polythiol compound (A) (radical generator) (C) / thiol group) is preferably 0.025 or more. Thereby, adhesiveness improves. From this viewpoint, the ratio (thermal radical generator / thiol group) is preferably 0.03 or more, more preferably 0.035 or more, and further preferably 0.04 or more. From the viewpoint of improving adhesion, the ratio (thermal radical generator / thiol group) is preferably 0.5 or less, more preferably 0.45 or less, and further preferably 0.4 or less. is there.

  When the radical generator (C) includes a photoradical generator and a thermal radical generator, the photoradical generator and the thermal radical generator with respect to the total number of moles of thiol groups contained in the polythiol compound (A). The ratio of the total number of moles {(photo radical generator and thermal radical generator) / thiol group} is preferably 0.025 or more. Thereby, adhesiveness improves. From this viewpoint, the ratio {(photo radical generator and thermal radical generator) / thiol group} is preferably 0.03 or more, more preferably 0.035 or more, and further preferably 0.04 or more. It is. From the viewpoint of improving adhesion, the ratio {(photo radical generator and thermal radical generator) / thiol group} is preferably 0.5 or less, more preferably 0.45 or less, and further Preferably it is 0.4 or less.

As an optional component, a compound containing a carbon-carbon double bond may be blended. However, when the compounding quantity of this compound containing a carbon-carbon double bond increases, a polythiol compound (A) will react with the compound containing this carbon-carbon double bond. This makes it difficult for the thiol-ene reaction between the polythiol compound (A) and the carbon-carbon double bond in the rubber to occur, which may reduce the adhesion of the coating composition to the rubber. Alternatively, a reaction in which the sulfur atom of the thiol group of the polythiol compound (A) and the carbon atom of the carbon-carbon bond are chemically bonded hardly occurs due to the hydrogen abstraction reaction from the carbon-carbon bond main chain of the rubber. Thus, the adhesion of the coating composition to rubber may be reduced. Therefore, the ratio of the total number of moles of carbon-carbon double bonds contained in the compound containing carbon-carbon double bonds to be blended to the total number of moles of thiol groups contained in the blended polythiol compound (A) (carbon -Carbon double bond / thiol group) is preferably less than 0.4, preferably less than 0.1, more preferably 0.08 or less, and 0.05 or less. More preferably, it is still more preferably 0.01 or less.
Here, the total number of moles of carbon-carbon double bonds contained in the compound containing a carbon-carbon double bond to be blended is the carbon-carbon of one molecule of the compound in the number of moles of the compound to be blended. It can be determined by multiplying the number of double bonds.
Further, the ratio of the number of moles (carbon-carbon double bond / thiol group) includes the total number of moles of carbon-carbon double bonds obtained as described above in the blended polythiol compound (A). It can be determined by dividing by the total number of moles of thiol groups.

As described above, the coating composition according to the present invention may contain an optional component in addition to the essential components (A) to (C). However, the total content of components (A) to (C) in the coating composition is preferably 80% by mass or more from the viewpoint of strongly adhering the coating agent or the coating sheet to rubber articles, particularly vulcanized rubber articles. More preferably, it is 90 mass% or more, More preferably, it is 95 mass% or more, More preferably, it is 98 mass% or more.
From the same viewpoint, the total content of the components (A) to (E) is preferably 90% by mass or more, more preferably 95% by mass or more, further preferably 99% by mass or more, and further preferably 100% by mass. .

[Coating agent]
The coating agent used by this invention contains said coating composition. This coating agent may contain components other than the coating composition as long as the object of the present invention is not impaired. However, from the viewpoint of satisfactorily expressing the effects of the present invention, the content of the coating composition in the coating agent is preferably 90% by mass or more, more preferably 95% by mass or more, still more preferably 99% by mass or more, Preferably it is 100 mass%.
This coating agent can be applied to at least a part of the surface of the rubber article and adhered to form a coating body.

[Coating sheet]
In the present invention, the coating agent may be used after forming a coating sheet. The coating sheet is formed by using the above-described coating composition or a coating agent containing the coating composition.
This coating sheet can be suitably manufactured by applying the coating composition or the coating agent on a release sheet such as a release paper or a release film, or by thin-film extrusion molding and then holding the sheet shape. By this holding, it is considered that at least a part of the thiol group and the isocyanate group in the coating composition undergoes a thiol urethane reaction to form a sheet shape.
In order to maintain the sheet shape, after forming the coating sheet, it is allowed to stand in the air at 0 to 60 ° C. for 1 minute or longer, and then the coating sheet is attached to at least a part of the surface of the rubber article. This is preferable because the handling of the sheet can be facilitated and the adhesion workability can be improved. The standing temperature is more preferably 5 to 40 ° C, and further preferably 15 to 40 ° C. The standing time can be adjusted by the amount of the urethanization catalyst. From the viewpoint of maintaining the sheet shape so that the sheet shape can be maintained during the workability of sheet formation and the adhesion work, it is preferably 1 minute or longer, more preferably 3 minutes or longer. There is no upper limit to the standing time, and it is not particularly limited, but it is preferably 24 hours or less, more preferably 10 hours or less, and even more preferably 5 hours or less from the viewpoint of storage.
Further, if desired, after forming the coating sheet, the coating sheet is heated by heating to such an extent that the radical reaction by the radical generator does not start, or by light irradiation to the extent that the radical reaction by all radical generators is not completed. May be manufactured. For example, the coating sheet may be preheated at 65 to 100 ° C. for about 1 to 3 minutes and then adhered to at least a part of the surface of the rubber article.

The material of the release sheet is not particularly limited, but polyester resins such as polyethylene terephthalate (PET), polycyclohexylene terephthalate, polyethylene naphthalate, and polyamide resins such as nylon 46, modified nylon 6T, nylon MXD6, and polyphthalamide. In addition to ketone resins such as polyphenylene sulfide and polythioether sulfone and sulfone resins such as polysulfone and polyether sulfone, polyether nitrile, polyarylate, polyetherimide, polyamideimide, polycarbonate, polymethyl methacrylate, triacetyl A transparent resin substrate mainly composed of an organic resin such as cellulose, polystyrene, or polyvinyl chloride can be suitably used.
The thickness of the coating sheet (however, excluding the release sheet) can be appropriately selected according to the object to be adhered, the required adhesion strength, and the like, and is, for example, 10 μm to 10 mm, preferably 20 μm to 10 mm, more preferably 30 μm to 10 mm.
Needless to say, when a coating sheet is used, it is used after peeling or peeling off the release sheet.

[Rubber articles]
The rubber article may be a vulcanized rubber article or an unvulcanized rubber article. According to the adhesion method of the present invention, even if the rubber article is an unvulcanized rubber article, it is possible to strongly adhere to the adherend.
The rubber article preferably has a carbon-carbon double bond. In this case, the carbon atom of the carbon-carbon double bond possessed by the rubber in contact with the coating agent or the coating sheet is the sulfur atom of the thiol group of the polythiol compound (A) possessed by the coating agent or the coating sheet and the carbon-sulfur. Presumed to form a bond.
However, even if the rubber article does not have a carbon-carbon double bond, it is presumed that the rubber article and the coating body can be adhered to each other. In this case, the sulfur atom of the thiol group of the polythiol compound (A) and the carbon atom of the carbon-carbon bond are caused by a hydrogen abstraction reaction from the carbon-carbon bond main chain present in the rubber article by the polythiol compound (A). Presumed to be chemically bound. However, from the viewpoint of improving the adhesion, the rubber constituting the rubber layer preferably has a carbon-carbon double bond.
The material of the rubber article is not particularly limited, but diene rubber made of natural rubber or conjugated diene synthetic rubber is preferable. Here, as the conjugated diene synthetic rubber, synthetic polyisoprene rubber (IR), polybutadiene rubber (BR), styrene-butadiene copolymer rubber (SBR), acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), butyl rubber (IIR), halogenated butyl rubber (Cl-IIR, Br-IIR, etc.), ethylene-propylene-diene copolymer rubber (EPDM), ethylene-butadiene copolymer rubber, propylene-butadiene copolymer rubber and the like. . Further, as other rubbers used as a material for rubber articles, synthetic rubbers such as hyperon rubber (chlorosulfonated polyethylene rubber), ethylene-propylene copolymer rubber (EPM), and polysiloxane rubber can be cited. Moreover, you may use rubber | gum in combination of 2 or more types.

(Application method)
In the present invention, the coating method is not limited when the coating agent is applied to at least part of the surface of the rubber article, or when the coating agent is formed by applying the coating agent to a release sheet or the like. For example, coating methods such as brush coating, roller brush coating, tampo coating, spatula coating, etc. by manual or machine operation; coating method by inkjet printing; spray coating such as spray coating, hot spray coating, airless spray coating, hot airless spray coating Curtain flow coating; flow coating; roll coating; gravure coating; dip coating (dipping); rolling coating; spin coating; reverse coating; bar coating; screen coating; blade coating; air knife coating; Various coating methods such as die molding method; thin film extrusion molding method and the like are included.

  When pressing pressure is applied to a rubber composite composed of a coating body and a rubber article obtained by applying and adhering the coating agent to at least a part of the surface of the rubber article, the adhesion is improved and the coating agent is applied from the laminate. From the viewpoint of preventing or suppressing leakage, the press pressure is preferably 0 to 5 MPa, more preferably 0 to 2.5 MPa, and still more preferably 0 to 1 MPa. From the same viewpoint, the pressing time is preferably 5 to 120 minutes, more preferably 10 to 60 minutes, and further preferably 15 to 45 minutes.

In the case of using a coating sheet, the rubber composite composed of the coating body and the rubber article may be obtained through one coating sheet, or obtained through two or more coating sheets. It may be. From the viewpoint of cost and workability, it is preferable to use one or two coating sheets. In particular, when it is preferable to use a coating sheet having better adhesion to rubber and a coating sheet having better adhesion to the adherend, it can be said that it is preferable to use two coating sheets.
In the case of applying a press pressure to the laminated body of the rubber and the adherend through the coating sheet, the press pressure is preferably 0.1 to 5 MPa, more preferably 0.4 from the viewpoint of improving the adhesion. It is -4MPa, More preferably, it is 0.5-3MPa, More preferably, it is 1.5-3MPa.

In the present invention, when the coating agent contains a photo radical generator as a radical generator, curing is preferably performed by light irradiation. As the light, at least one selected from electromagnetic waves such as ultraviolet rays, visible rays, infrared rays, and X-rays; and particle beams such as α rays, γ rays, and electron beams can be preferably used. Among these, ultraviolet rays are preferable as the light. From the viewpoint of improving the adhesion and reducing the cost, an ultraviolet lamp can be suitably used as the light source. From the same viewpoint, the light irradiation time is preferably several seconds to several tens of seconds, more preferably 1 second to 40 seconds, and further preferably 3 seconds to 20 seconds.
When the coating agent contains a thermal radical generator as a radical generator, curing is preferably performed by heating. The temperature at which the thermal radical generator efficiently generates radicals can be appropriately selected as the heating temperature, but it is preferably about 1 minute half-life temperature of ± 30 ° C. of the thermal radical generator.
In any operation of light irradiation and heating, as long as light energy and / or heat energy is transmitted to the coating agent, there is no particular limitation on the portion to be irradiated and / or the portion to be heated. And / or may be heated. That is, the coating agent may be directly irradiated and / or heated, or the coating agent may be irradiated and / or heated via a rubber article. This is because the rubber article may transmit light.
It should be noted that the fact that a strong adhesion can be obtained even when cured by heating is beneficial in that a heating method can be employed when it is difficult to sufficiently irradiate the coating agent with light, and the laminated body It is easy to operate and is preferable in that it can be strongly adhered even if light irradiation and / or heating is applied to any part of the throat.
In any operation of light irradiation and heating, as long as light energy and / or heat energy is transmitted to the coating sheet, there is no particular limitation on the portion to be irradiated and / or the portion to be heated. And / or may be heated. That is, the coating sheet may be directly heated or irradiated with light, or the coating sheet may be heated or irradiated with light through a rubber article.
In addition, as described above, the fact that a strong adhesion can be obtained even when cured by heating is beneficial in that a heating method can be employed when it is difficult to sufficiently irradiate the coating agent, and It is preferable because it can be easily operated even if it is heated and / or irradiated with light to any part of the coating body.

[Rubber composite]
In the rubber composite of the present invention, the carbon atom in the rubber of the rubber layer in contact with the coating agent or the coating sheet is a sulfur atom of the thiol group of the polythiol compound (A) contained in the coating agent or the coating sheet. It is thought that strong adhesion is expressed by forming a carbon-sulfur bond.
In this carbon-sulfur bond, another part of the polythiol compound (A) reacts with the radical generator (C) to generate a thiyl radical, which reacts with a carbon-carbon double bond present in the rubber. Or the sulfur atom of the thiol group of the polythiol compound (A) and the carbon atom of the carbon-carbon bond by a hydrogen abstraction reaction from the carbon-carbon bond main chain present in the rubber. Is considered to be formed by chemically bonding.

  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.

[Raw materials]
As raw materials, the following were used.
<Polythiol Compound (A) (Component (A))>
PEMP: pentaerythritol tetrakis (3-mercaptopropionate): manufactured by SC Organic Chemical Co., Ltd., trade name “PEMP”, 4 thiol groups DPMP: dipentaerythritol hexakis (3-mercaptopropionate): SC organic chemistry Product name "DPMP", 6 thiol groups

<Isocyanate group-containing compound (B) (component (B))>
N3200: HDI burette-modified isocyanate: manufactured by Sumitomo Bayer Urethane Co., Ltd., trade name “Desmodur N3200”, two isocyanate groups, NCO content: 23.0% by mass
Z4470BA: IPDI isocyanurate-modified isocyanate: manufactured by Sumika Bayer Urethane Co., Ltd., trade name “Desmodur Z4470BA”, two isocyanate groups, NCO content: 11.9% by mass

<Radical generator (C) (component (C))>
IRGACURE 184: 1-hydroxycyclohexyl phenyl ketone: product name “IRGACURE 184” manufactured by BASF
Perbutyl O: t-butyl-2-ethylperoxyhexanoate: Nippon Oil & Fats Co., Ltd., trade name “Perbutyl O”
Perbutyl D: Di-t-butyl peroxide: manufactured by NOF Corporation, trade name “Perbutyl D”

<Urethaneization catalyst (D) (component (D))>
TEDA: Triethylenediamine: Product name “DABCO 33LV catalyst” manufactured by Air Products

<Surface Conditioner (E) (Component (E))>
BYK-307: Mixture of polyether-modified polydimethylsiloxane and polyether: manufactured by Big Chemie Japan, trade name “BYK-307”, content: 100%

[Measurement of thiol group content]
The total number of moles of thiol groups contained in the blended polythiol compound (A) was calculated by dividing the blended amount by the theoretical molecular weight and multiplying by the number of thiol groups possessed by one molecule of the polythiol compound (A). .

[Measurement of isocyanate group content]
The total number of moles of isocyanate groups contained in the blended isocyanate group-containing compound (B) was measured by JIS K1603-1 B method.

[Manufacture of rubber articles]
A rubber article (length 100 mm × width 25 mm × thickness 10 mm) was produced according to the formulation shown in Table 1 below.

The details of each component in Table 1 are as follows.
Natural rubber (NR): RSS # 3
Polybutadiene rubber (BR): Product name “JSR BRO1” manufactured by JSR Corporation
Styrene-butadiene copolymer rubber (SBR): Product name “JSR 1500” manufactured by JSR Corporation
Carbon black: Asahi Carbon Co., Ltd., trade name “Asahi # 70”
Anti-aging agent: N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine, manufactured by Ouchi Shinsei Chemical Co., Ltd., trade name “NOCRACK 6C”
Vulcanization accelerator 1: 1,3-diphenylguanidine, manufactured by Ouchi Shinsei Chemical Co., Ltd., trade name “Noxeller D (DP)”
Vulcanization accelerator 2: Di-2-benzothiazolyl disulfide, manufactured by Ouchi Shinsei Chemical Industry Co., Ltd., trade name “Noxeller DM-P (DM)”

[Measurement method of adhesion strength of coated body obtained from coating agent application]
The coating agent was applied to a rubber article so as to have a thickness of 30 μm, and the coated surface was cured. Curing, in the case of coated tablets containing only photoradical generator, 200~400mW / cm ^2, was irradiated with ultraviolet rays under conditions of 1000~4000mJ / cm ^2. In the case of a coating agent containing only a thermal radical generator, the coating was carried out at a temperature of 150 ° C. for 30 minutes while applying a press pressure of 0.05 MPa. For coating agent containing a photo-radical generator and a heat radical generator, 200~400mW / cm ^2, after the ultraviolet irradiation under the condition of 500~1000mJ / cm ^2, at a temperature 0.99 ° C., 0.05 MPa This was carried out by holding for 30 minutes while applying the press pressure. The adhesion strength of the obtained coated body and rubber article was measured by a cross cut test (cross cut method) according to JIS K5600-5-6. In this method, a film is cut with a blade using a guide, and the peeling of the film is observed when the cellophane tape is attached and then peeled off at an angle close to 60 ° C. The test was performed at 5 × 5 25 squares × 4 locations per test piece, and the evaluation was performed based on the number of squares remaining without peeling.
<Criteria>
A: 100/100 (there is no peeling of one cell)
○: (80/100) to (99/100)
Δ: (50/100) to (79/100)
X: (0/100) to (49/100) or measurement is impossible because the coating body is uncured.
[Measurement method of adhesion strength of coated body obtained from coating sheet]
Alternatively, a coating sheet having a thickness of 30 μm was attached to a part of the surface of the rubber article, and then the coating sheet was cured. Curing is the same as in the case of a coating body obtained from application of a coating agent. The adhesion strength of the obtained coated body and rubber article was measured by a cross cut test (cross cut method) according to JIS K5600-5-6. In this method, a film is cut with a blade using a guide, and the peeling of the film is observed when the cellophane tape is applied and then peeled off at an angle close to 60 ° C. The test was performed at 5 × 5 25 squares × 4 locations per test piece, and the evaluation was performed based on the number of squares remaining without peeling.
<Criteria>
A: 100/100 (there is no peeling of one cell)
○: (80/100) to (99/100)
Δ: (50/100) to (79/100)
X: (0/100) to (49/100) or measurement is impossible because the coating body is uncured.
If the number of remaining squares is 80/100 or more, it has sufficient adhesion that does not easily peel from the base material of the rubber article. Preferably it is 100/100.
On the other hand, if it is less than 80/100, the reaction between the base material of the rubber article and the coating agent is not sufficient, and peeling occurs at the interface. In such a state, it cannot be said that the adhesion is sufficient.

[Measurement method of curability of coated body]
The surface of the coated body was touched with a finger, and the presence or absence of a tacky feeling (adhesive feeling) was evaluated functionally.
○: No tack feeling ×: Tack feeling

[Measurement method of decorativeness of coated body]
Colored particles (Art Pearl: manufactured by Negami Kogyo Co., Ltd.) were added to the coating body by visual observation, and the decorating property was evaluated.
○: The coating body is uniformly decorated.
X: The coating body is unevenly decorated, or the coating body is uncured.

[Examples 1-8 and Comparative Examples 1-6 and Examples 9-16 and Comparative Examples 7-12]
In Examples 1 to 8 and Comparative Examples 1 to 6 (coating bodies obtained from application of the coating agent), the isocyanate group-containing compound to be blended with respect to the total number of moles of thiol groups contained in the blended polythiol compound (A) By changing the ratio of the total number of moles of isocyanate groups contained in (B) (isocyanate groups / thiol groups), the ratio (isocyanate groups / thiol groups) and the adhesion between the rubber article, curability and decorating properties. We examined the relationship.
In Examples 9 to 16 and Comparative Examples 7 to 12 (coating bodies obtained from coating sheets), the coating agents of 1 to 8 and Comparative Examples 1 to 6 (coating bodies obtained from application of the coating agent) were coated. The relationship between the ratio (isocyanate group / thiol group) and the adhesion strength, curability and decorating property with the rubber article was examined in the same manner except that the sheet was used.
Next, these examples and comparative examples will be specifically described.

<Examples 1-8 and Comparative Examples 1-6 (coating bodies obtained from application of coating agent)>
As shown in Table 2 below (each component represents a part by mass), each component was blended to obtain a coating composition, and the coating composition was used as a coating agent.
The obtained coating agent was cured as described above, and the adhesion of the cured coating agent was measured as described above. Rubber article 1 (NR / BR blend) was used as the rubber article. The results are shown in Table 5.
In Tables 2, 3, and 4, the thiol functional group concentration refers to the concentration (mmol / g) of thiol groups in the total amount of the coating agent or the total amount of the coating sheet. Further, the NCO functional group concentration refers to the concentration (mmol / g) of isocyanate groups in the total amount of the coating agent or the total amount of the coating sheet. Furthermore, the generator concentration refers to the concentration (mmol / g) of the radical generator in the total amount of the coating agent or the total amount of the coating sheet.
However, since each component may react with each other or decompose, each value is a value calculated before each component reacts or decomposes, in other words, each component immediately before mixing. A theoretical value calculated from the amount of the component was used.

<Examples 9 to 16 and Comparative Examples 7 to 12 (coating bodies obtained from coating sheets)>
As shown in Table 2, in Examples 9 to 16 and Comparative Examples 7 to 12, the same coating agents as in Examples 1 to 8 and Comparative Examples 1 to 6 were prepared, respectively.
Each coating agent was applied on a PET film release sheet and held at room temperature for 30 minutes to obtain a coating sheet having a length of 100 mm, a width of 25 mm, and a thickness of 30 μm.
The obtained coating sheet was cured as described above, and the adhesive strength of the cured body of the coating sheet was measured as described above. As the rubber article, rubber article 1 (NR / BR blend) was used in the same manner as in Example 1. The results are shown in Table 5.

[Examples 17 to 24 and Comparative Examples 13 to 18 and Examples 25 to 32 and Comparative Examples 19 to 24]
As shown in Table 3, the component (C) was changed from a photo radical generator {1-hydroxycyclohexyl phenyl ketone (IRGACURE184): manufactured by BASF} to a thermal radical generator {t-butyl-2-ethylperoxyhexanoate ( The relationship between the ratio of the total number of moles (isocyanate group / thiol group) and the adhesive strength, curability and decorating properties of the rubber article 1 (NR / BR blended) is the same except that it is changed to perbutyl O)}. Was evaluated by the method described above. The results are shown in Table 6.

[Examples 33 to 40 and Comparative Examples 25 to 31 and Examples 41 to 48 and Comparative Examples 32 to 38]
As shown in Table 4, the component (C) was converted into a photo radical generator {1-hydroxycyclohexyl phenyl ketone (IRGACURE184): manufactured by BASF} and a heat radical generator {di-t-butyl peroxide (perbutyl D)}. In the same manner except for changing to the combined use, the relationship between the ratio of the total number of moles (isocyanate group / thiol group) and the adhesion, curability and decorating properties of the rubber article 1 (NR / BR blend) is The method was evaluated. The results are shown in Table 7.

[Examples 49 to 56 and Comparative Examples 39 to 44 and Examples 57 to 64 and Comparative Examples 45 to 50]
Using the coating agent and the coating sheet having the composition shown in Table 2 which is the same composition as Examples 1 to 8 and Comparative Examples 1 to 6 and Examples 9 to 16 and Comparative Examples 7 to 12, the ratio of the total number of moles ( (Isocyanate group / thiol group) and the relationship between the adhesion strength, curability and decorating properties of rubber article 2 (SBR blending) were evaluated by the above methods. The results are shown in Table 8.

[Examples 65-72 and Comparative Examples 51-56 and Examples 73-80 and Comparative Examples 57-62]
Using the coating agents and coating sheets having the composition shown in Table 3 which is the same composition as Examples 17 to 24 and Comparative Examples 13 to 18 and Examples 25 to 32 and Comparative Examples 19 to 24, the ratio of the total number of moles ( (Isocyanate group / thiol group) and the relationship between the adhesion strength, curability and decorating properties of rubber article 2 (SBR blending) were evaluated by the above methods. The results are shown in Table 9.

[Examples 81-88 and Comparative Examples 63-69 and Examples 89-96 and Comparative Examples 70-76]
The ratio of the total number of moles using the coating agent and the coating sheet having the composition shown in Table 4 which is the same composition as in Examples 33 to 40 and Comparative Examples 25 to 31 and Examples 41 to 48 and Comparative Examples 32 to 38 ( (Isocyanate group / thiol group) and the relationship between the adhesion strength, curability and decorating properties of rubber article 2 (SBR blending) were evaluated by the above methods. The results are shown in Table 10.

[Examples 97 to 104 and Comparative Examples 77 to 82 and Examples 105 to 112 and Comparative Examples 83 to 88]
Using the coating agent and the coating sheet having the composition shown in Table 2 which is the same composition as Examples 1 to 8 and Comparative Examples 1 to 6 and Examples 9 to 16 and Comparative Examples 7 to 12, the ratio of the total number of moles ( (Isocyanate group / thiol group) and the relationship between the adhesion strength, curability and decorating properties of rubber article 3 (NR blend) were evaluated by the above methods. The results are shown in Table 11.

[Examples 113 to 120 and Comparative Examples 89 to 94 and Examples 121 to 128 and Comparative Examples 95 to 100]
Using the coating agents and coating sheets having the composition shown in Table 3 which is the same composition as Examples 17 to 24 and Comparative Examples 13 to 18 and Examples 25 to 32 and Comparative Examples 19 to 24, the ratio of the total number of moles ( (Isocyanate group / thiol group) and the relationship between the adhesion strength, curability and decorating properties of rubber article 3 (NR blend) were evaluated by the above methods. The results are shown in Table 12.

[Examples 129 to 136 and Comparative Examples 101 to 107 and Examples 137 to 144 and Comparative Examples 108 to 114]
The ratio of the total number of moles using the coating agent and the coating sheet having the composition shown in Table 4 which is the same composition as in Examples 33 to 40 and Comparative Examples 25 to 31 and Examples 41 to 48 and Comparative Examples 32 to 38 ( (Isocyanate group / thiol group) and the relationship between the adhesion strength, curability and decorating properties of rubber article 3 (NR blend) were evaluated by the above methods. The results are shown in Table 13.

[Evaluation]
As shown in Tables 2 to 13, Examples 1 to 144 include components (A) to (C) and are included in the component (B) with respect to the total number of moles of thiol groups included in the component (A). Since the ratio of the total number of moles of isocyanate groups (isocyanate group / thiol group) was 0.2 or more and 0.8 or less, all of adhesion, curability and decorating properties were good.
On the other hand, in Comparative Examples 1-114, (isocyanate group / thiol group) was less than 0.2 or greater than 0.8, so the adhesion was low.
Thus, in the production method of the present invention, the carbon atom in the rubber of the rubber layer in contact with the coating agent or the coating sheet is the sulfur atom of the thiol group of the polythiol compound (A) contained in the coating agent or the coating sheet. In order to develop a strong adhesion by forming a carbon-sulfur bond with each other, it was possible to produce a coating body by easily and strongly adhering without taking time and effort.

  The production method of the present invention is a rubber composite in which a rubber article, particularly a vulcanized rubber article and a coating body are suitably adhered, in particular, a tire, various industrial rubber products such as a rubber hose, an anti-vibration rubber, a rubber belt, a rubber dam, a belt. It can be used for manufacturing conveyors, packings, and the like.

Claims (8)

A compound comprising a polythiol compound (A), an isocyanate group-containing compound (B), and a radical generator (C), and the isocyanate group-containing compound relative to the total number of moles of thiol groups contained in the polythiol compound (A) ( A coating agent containing a composition having a ratio of the total number of moles of isocyanate groups contained in B) (isocyanate groups / thiol groups) of 0.20 or more and 0.80 or less is adhered to at least a part of the surface of the rubber article. After
A method for producing a rubber composite comprising the coating body and the rubber article, wherein the coating agent is formed by subjecting the coating agent to at least one of heating and light irradiation. A compound comprising a polythiol compound (A), an isocyanate group-containing compound (B), and a radical generator (C), and the isocyanate group-containing compound relative to the total number of moles of thiol groups contained in the polythiol compound (A) ( Forming a coating sheet comprising a coating agent comprising a composition in which the ratio of the total number of isocyanate groups contained in B) (isocyanate group / thiol group) is 0.20 or more and 0.80 or less,
After attaching the coating sheet to at least a part of the surface of the rubber article,
A method for producing a rubber composite comprising the coating body and the rubber article, wherein the coating sheet is formed by subjecting the coating sheet to at least one of heating and light irradiation.   The method for producing a rubber composite according to claim 1, wherein the coating agent is applied and adhered to at least a part of the surface of the rubber article.   3. The rubber composite according to claim 2, wherein after forming the coating sheet, the rubber sheet is allowed to stand in air for 1 minute or more at 0 to 60 ° C., and then the coating sheet is attached to at least a part of the surface of the rubber article. Production method.   The radical generator (C) contains a photo radical generator, and the ratio of the total number of moles of the photo radical generator to the total number of moles of thiol groups contained in the polythiol compound (A) (photo radical generator / The method for producing a rubber composite according to any one of claims 1 to 4, wherein the thiol group is 0.0005 or more.   The radical generator (C) contains a thermal radical generator, and the ratio of the total number of moles of the thermal radical generator to the total number of moles of thiol groups contained in the polythiol compound (A) (thermal radical generator / The method for producing a rubber composite according to any one of claims 1 to 4, wherein the (thiol group) is 0.025 or more.   The radical generator (C) includes a photo radical generator and a thermal radical generator, and the total number of moles of the radical generator (C) with respect to the total number of moles of thiol groups contained in the polythiol compound (A). The method for producing a rubber composite according to any one of claims 1 to 4, wherein the ratio (radical generator (C) / thiol group) is 0.025 or more. The method for producing a rubber composite according to any one of claims 1 to 7, wherein the rubber article is a vulcanized rubber article.