Two-component acrylic adhesive for vulcanized rubber

Abstract

The present application provides a two-component type acrylic adhesive for vulcanized rubber with excellent adhesion. The two-component type acrylic adhesive for vulcanized rubber of the present application is composed of an A agent and a B agent, wherein the A agent contains a (meth)acrylate represented by the following formula (1) and a radical generator, and the B agent contains a (meth)acrylate represented by the following formula (1), a reducing agent, and a polyurethane. CH2=C(R 11 )‑CO‑O‑R 12 (1) In formula (1), R 11 represents a hydrogen atom or a methyl group, and R 12 represents an alkyl group having 4 to 17 carbon atoms.

Description

TECHNICAL FIELD

[0001] The present application relates to a two-component type acrylic adhesive for vulcanized rubber. BACKGROUND

[0002] As an adhesive, a two-component type acrylic adhesive is known (for example, Patent Document 1).

[0003] PRIOR ART DOCUMENTS

[0004] PATENT DOCUMENTS

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 2001-55421 SUMMARY

[0006] PROBLEMS TO BE SOLVED BY THE INVENTION

[0007] Recently, there is a system that monitors information (for example, air pressure, etc.) of a tire installed in an automobile using IoT (Internet of Things). In the above system, the tire has a container that houses a device such as a sensor (detector) for monitoring tire information in the inside thereof. Generally, the above container is fixed to the tire (for example, inner liner) with an adhesive.

[0008] The present inventors and others have formulated a two-component type acrylic adhesive with reference to Patent Document 1, coated the above adhesive on the surface of the inner liner, and performed press bonding of a rubber container that houses a sensor, and as a result, it was confirmed that the adhesion thereof was not necessarily sufficient.

[0009] Therefore, the present application aims to provide a two-component type acrylic adhesive for vulcanized rubber that has excellent adhesion, in view of the above actual situation.

[0010] METHOD FOR SOLVING THE PROBLEMS

[0011] The present inventors and others have conducted intensive research in order to solve the above problems, and as a result, it was found that the above problems can be solved by being composed of an A agent that contains a specific (meth)acrylate and a radical generator, and a B agent that contains a specific (meth)acrylate, a reducing agent, and a polyurethane, thereby completing the present application.

[0012] That is, the present inventors and others have found that the above problems can be solved by being composed of the following.

[0013] (1) A two-component type acrylic adhesive for vulcanized rubber, composed of an A agent and a B agent, the above A agent containing a (meth)acrylate represented by the following formula (1) and a radical generator,

[0014] the above B agent containing a (meth)acrylate represented by the following formula (1), a reducing agent, and a polyurethane.

[0015] CH2=C(R 11 )-CO-O-R 12 (1)

[0016] In formula (1), R 11 represents a hydrogen atom or a methyl group, R 12 represents an alkyl group having 4 to 17 carbon atoms.

[0017] (2) The two-component type acrylic adhesive for a vulcanized rubber according to the above (1), wherein a mass ratio of a total of the (meth)acrylate in the A agent and the (meth)acrylate in the B agent to the polyurethane in the B agent is 3 / 7 to 8 / 2.

[0018] (3) The two-component type acrylic adhesive for a vulcanized rubber according to the above (1) or (2), wherein a number average molecular weight of the polyurethane is 2,000 or more and 100,000 or less, and the polyurethane is obtained by reacting a polyisocyanate with a polyol.

[0019] Effects of the Invention

[0020] As described below, according to the present application, it is possible to provide a two-component type acrylic adhesive for a vulcanized rubber which is excellent in adhesion. DETAILED DESCRIPTION

[0021] Hereinafter, a two-component type acrylic adhesive for a vulcanized rubber of the present application will be described.

[0022] Further, in the present specification, a numerical range represented by "to" means a range including the numerical values recited before and after "to" as lower limit values and upper limit values.

[0023] Further, each component contained in the two-component type acrylic adhesive for a vulcanized rubber of the present application can be used alone in one kind, or two or more kinds can be used in combination. Here, regarding each component, in the case where two or more kinds are used in combination, regarding the content of the component, unless otherwise specified, it means a total content.

[0024] Further, in the present specification, "(meth)acrylate" means acrylate or methacrylate.

[0025] The two-component type acrylic adhesive for a vulcanized rubber of the present application (hereinafter, also referred to as "the adhesive of the present application") is a two-component type acrylic adhesive for a vulcanized rubber composed of an A agent and a B agent,

[0026] The above A agent contains a (meth)acrylate represented by the following formula (1) and a radical generator,

[0027] The above-mentioned B agent contains a (meth)acrylate represented by the following formula (1), a reducing agent, and a polyurethane.

[0028] Hereinafter, each component contained in the adhesive of the present application will be described.

[0029] [A agent]

[0030] The A agent contains a (meth)acrylate represented by the following formula (1) and a radical generator.

[0031] [Specific monomer]

[0032] As described above, the A agent contains a (meth)acrylate represented by the following formula (1) (hereinafter, also referred to as "specific monomer").

[0033] CH2=C(R 11 )-CO-O-R 12 (1)

[0034] In formula (1), R 11 represents a hydrogen atom or a methyl group, and R 12 represents an alkyl group having 4 to 17 carbon atoms.

[0035] < R 11 >

[0036] As described above, in formula (1), R 11 represents a hydrogen atom or a methyl group. Among them, a methyl group is preferable based on the reason that the adhesiveness, coatability, durability, and heat resistance are more excellent.

[0037] Hereinafter, "the adhesiveness, coatability, durability, and heat resistance are more excellent" will also be referred to as "the effects and the like of the present application are more excellent".

[0038] < R 12 >

[0039] As described above, in formula (1), R 12 represents an alkyl group having 4 to 17 carbon atoms.

[0040] The above-mentioned alkyl group can be any one of a linear shape, a branched shape, and a cyclic shape, but a linear shape is preferable based on the reason that the effects and the like of the present application are more excellent.

[0041] The above-mentioned number of carbon atoms (hereinafter, also referred to as "the number of carbon atoms of the specific monomer") is preferably 4 to 12, more preferably 4 to 10, further preferably 4 to 8, and particularly preferably 4 to 6 based on the reason that the effects and the like of the present application are more excellent.

[0042] <Specific examples>

[0043] As specific examples of the specific monomer, mention can be made of butyl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, heptadecyl (meth) acrylate, and the like. Of these, (meth) acrylate butyl (meth) acrylate, octyl (meth) acrylate are preferable for the reason that they are more excellent in the effects of the present application and the like, and (meth) acrylate butyl (meth) acrylate is more preferable.

[0044] <Content>

[0045] The content of the specific monomer in the A agent is not particularly limited, but for the reason that it is more excellent in the effects of the present application and the like, it is preferably 50% by mass or more, more preferably 70% by mass or more, and further preferably 90% by mass or more, relative to the entire A agent. The upper limit is not particularly limited, but for the reason that it is more excellent in the effects of the present application and the like, it is preferably 99% by mass or less, more preferably 97% by mass or less, and further preferably 95% by mass or less.

[0046] [Radical Generator]

[0047] The radical generator generates radicals by coming into contact with the reducing agent in the B agent described later. In addition, the specific monomers in the A agent and the B agent undergo radical polymerization by the radicals generated, and the adhesive of the present application is cured.

[0048] For the reason that it is more excellent in the effects of the present application and the like, the radical generator is preferably an organic peroxide.

[0049] As the above-mentioned organic peroxide, mention can be made of, for example, hydrogen peroxide-based compounds such as t-butyl hydroperoxide, terpene hydroperoxide, cumene hydroperoxide, diisopropylbenzene hydroperoxide, and the like, peroxy ester-based compounds such as t-butyl peroxybenzoate, t-butyl peroxylaurate, t-butyl peroxydecanoate, and the like. Of these, for the reason that it is more excellent in the effects of the present application and the like, hydrogen peroxide-based compounds are preferable, and t-butyl hydroperoxide is more preferable.

[0050] <Content>

[0051] The content of the radical generator in the A agent is not particularly limited, but for the reason that it is more excellent in the effects of the present application and the like, it is preferably 1 to 20% by mass, and more preferably 5 to 10% by mass, relative to the entire A agent.

[0052] [B Agent]

[0053] The B agent contains the specific monomer, the reducing agent, and a polyurethane.

[0054] [Specific Monomer]

[0055] The definition, specific examples, and suitable options of the specific monomer are the same as those of the specific monomer in the A agent described above. The specific monomer in the B agent can be the same as or different from the specific monomer in the A agent.

[0056] <Content>

[0057] The content of the specific monomer in the B agent is not particularly limited, but for the reason that the effect of the present application and the like are more excellent, it is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 30% by mass or more, relative to the entire B agent. The upper limit is not particularly limited, but for the reason that the effect of the present application and the like are more excellent, it is preferably 90% by mass or less, more preferably 70% by mass or less, and further preferably 50% by mass or less.

[0058] [Reducing agent]

[0059] The reducing agent is not particularly limited, and as specific examples, tertiary amines such as triethylamine and tripropylamine, 2-mercaptobenzimidazole, thiourea derivatives such as monobenzoylthiourea and ethylene thiourea, cobalt naphthenate, and vanadium compounds can be given. Among them, for the reason that the effect of the present application and the like are more excellent, a vanadium compound is preferred.

[0060] As specific examples of the vanadium compound, metal oxides such as vanadium pentoxide, vanadyl octoate, vanadyl naphthenate, and vanadyl stearate, metal chelates such as vanadyl acetylacetonate and vanadium acetylacetonate, and the like can be given. Among them, for the reason that the effect of the present application and the like are more excellent, a metal oxide is preferred, and vanadium pentoxide is more preferred.

[0061] <Content>

[0062] The content of the reducing agent in the B agent is not particularly limited, but for the reason that the effect of the present application and the like are more excellent, it is preferably 0.1 to 10% by mass, and more preferably 1 to 5% by mass, relative to the entire B agent.

[0063] [Polyurethane]

[0064] The polyurethane is not particularly limited as long as it is a polymer having a urethane bond.

[0065] For the reason that the effect of the present application and the like are more excellent, the polyurethane is preferably a substance obtained by polymerizing a polyisocyanate with a compound having two or more active hydrogen-containing groups in one molecule (active hydrogen compound).

[0066] The above polyisocyanate is not particularly limited as long as it is a substance having two or more isocyanate groups in the molecule.

[0067] As the above-mentioned polyisocyanate, for example, aromatic polyisocyanates such as toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI; for example, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate), 1,4-phenylene diisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), toluidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), triphenylmethane triisocyanate;

[0068] 1,6-hexane diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI), trans-cyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis(isocyanatomethyl)cyclohexane (H6XDI), dicyclohexylmethane diisocyanate (H 12 aliphatic polyisocyanates (including alicyclic polyisocyanates) such as MDI;

[0069] their carbodiimide-modified polyisocyanates;

[0070] their isocyanurate-modified polyisocyanates.

[0071] The above-mentioned compound having two or more active hydrogen-containing groups in one molecule (active hydrogen compound) is not particularly limited. As the active hydrogen-containing group, for example, a hydroxyl (OH) group, an amino group, an imino group can be mentioned.

[0072] As the above-mentioned active hydrogen compound, for example, a polyol compound having two or more hydroxyl (OH) groups in one molecule and the like are suitably mentioned, of which a polyol compound is preferable.

[0073] The above-mentioned polyol compound is not particularly limited as long as it is a compound having two or more hydroxyl groups. For example, polycarbonate polyol; polyether polyol; polyester polyol; acrylic polyol, polybutadiene diol, hydrogenated polybutadiene polyol, and the like having a polymer polyol having a carbon-carbon bond in the main chain skeleton; low molecular polyol; and a mixed polyol thereof can be mentioned. Of these, a polycarbonate polyol is preferable for the reason that it is more excellent in the effect of the present application and the like.

[0074] The method of producing the polyurethane is not particularly limited. For example, it can be produced by using a polyisocyanate in a manner that 1.5 to 2.5 moles of isocyanate groups react with respect to 1 mole of the active hydrogen-containing group (e.g., hydroxyl group) possessed by the active hydrogen compound, mixing them, and allowing them to react. Hereinafter, the number of moles of the isocyanate groups possessed by the polyisocyanate with respect to 1 mole of the active hydrogen-containing group possessed by the active hydrogen compound is also referred to as "NCO / OH".

[0075] <Content>

[0076] The content of the polyurethane in the B agent is not particularly limited, but for the reason that the effects of the present application and the like are more excellent, it is preferably 10% by mass or more, more preferably 20% by mass or more, further preferably 30% by mass or more, particularly preferably 40% by mass or more, and most preferably 50% by mass or more, with respect to the entire B agent. The upper limit is not particularly limited, but for the reason that the effects of the present application and the like are more excellent, it is preferably 90% by mass or less, more preferably 80% by mass or less, and further preferably 70% by mass or less.

[0077] [Specific monomer / polyurethane]

[0078] The mass ratio of the total of the specific monomer in the A agent and the specific monomer in the B agent to the polyurethane in the B agent is not particularly limited, but for the reason that the effects of the present application and the like are more excellent, it is preferably 1 / 9 to 9 / 1, more preferably 3 / 7 to 8 / 2, and further preferably 4 / 6 to 6 / 4.

[0079] Hereinafter, the "mass ratio of the total of the specific monomer in the A agent and the specific monomer in the B agent to the polyurethane in the B agent" is also referred to as "specific monomer / polyurethane".

[0080] [Radical generator / specific monomer]

[0081] The content of the radical generator in the A agent with respect to the total of the specific monomer in the A agent and the specific monomer in the B agent is not particularly limited, but for the reason that the effects of the present application and the like are more excellent, it is preferably 1 to 10% by mass, and more preferably 2 to 5% by mass.

[0082] Hereinafter, the "content of the radical generator in the A agent with respect to the total of the specific monomer in the A agent and the specific monomer in the B agent" is also referred to as "radical generator / specific monomer".

[0083] [Reducing agent / specific monomer]

[0084] The content of the reducing agent in the B agent with respect to the total of the specific monomer in the A agent and the specific monomer in the B agent is not particularly limited, but for the reason that the effects of the present application and the like are more excellent, it is preferably 1 to 10% by mass, and more preferably 2 to 5% by mass.

[0085] Hereinafter, the content of the reducing agent in the B agent relative to the total of the specific monomer in the A agent and the specific monomer in the B agent is also referred to as "reducing agent / specific monomer".

[0086] [specific monomer in A agent / specific monomer in B agent]

[0087] The mass ratio of the specific monomer in the A agent to the specific monomer in the B agent is not particularly limited, but for the reason that the effect according to the present application and the like are more excellent, it is preferably 1 / 9 to 9 / 1, more preferably 3 / 7 to 7 / 3, and further preferably 4 / 6 to 6 / 4.

[0088] Hereinafter, the mass ratio of the specific monomer in the A agent to the specific monomer in the B agent is also referred to as "specific monomer in A agent / specific monomer in B agent".

[0089] [radical generator / reducing agent]

[0090] The mass ratio of the radical generator in the A agent to the reducing agent in the B agent is not particularly limited, but for the reason that the effect according to the present application and the like are more excellent, it is preferably 1 / 9 to 9 / 1, more preferably 3 / 7 to 7 / 3, and further preferably 4 / 6 to 6 / 4.

[0091] Hereinafter, the mass ratio of the radical generator in the A agent to the reducing agent in the B agent is also referred to as "radical generator / reducing agent".

[0092] [arbitrary component]

[0093] The adhesive (A agent and / or B agent) of the present application can contain a component other than the above-mentioned components (arbitrary component).

[0094] As such an arbitrary component, a monomer other than the specific monomer (for example, a monofunctional (meth)acrylate other than the specific monomer, a polyfunctional (meth)acrylate), a polymer other than a polyurethane, a plasticizer, a balloon (hollow body), a curing catalyst, an age resistor, an antioxidant, a reaction modifier, a filler, a diluent (solvent), a thixotropic agent, a thickening agent, a dispersant, a pigment, and the like can be mentioned.

[0095] [modulation method]

[0096] The method of modulating the adhesive of the present application is not particularly limited, but for the A agent and the B agent each, a method of mixing the above-mentioned components, and the like can be mentioned.

[0097] In addition, the A agent and the B agent are mixed at the time of use.

[0098] [use]

[0099] The adhesive of the present application is useful as an adhesive for fixing other materials (e.g., a rubber-made container of a housing device) on a vulcanized rubber (e.g., a tire (particularly, an inner liner)).

[0100] Examples

[0101] Hereinafter, the present application is further explained in detail by examples, but the present application is not limited to them.

[0102] Preparation of the two-component type acrylic adhesive

[0103] Each of the A agent and the B agent shown in Table 1 was prepared by mixing each component in the proportions (parts by mass) shown in the table.

[0104] Adhesiveness

[0105] The A agent and the B agent of the obtained two-component type acrylic adhesive were mixed, and applied (application amount: 2 to 5 g / cm 2 ) to the inner liner of the inner surface of a tire (after vulcanization), and a rubber-made container (vulcanizate of a rubber composition containing natural rubber) that housed a sensor was crimped. After 1 day, the rubber-made container was peeled from the inner liner, and the peel strength at that time was measured. Further, the adhesiveness was evaluated based on the following criteria. The results are shown in Table 1. In practical use, it is preferable that it be, or, more preferable that it be, and further preferable that it be.

[0106] • : 25 N / m or more

[0107] • : 20 N / m or more and less than 24 N / m

[0108] • : 8 N / m or more and less than 19 N / m

[0109] • : Less than 8 N / m

[0110]

[0111] The details of each component in Table 1 are as follows.

[0112] • Comparative monomer 1: Methyl methacrylate represented by the above formula (1). Here, R 11 represents a methyl group, and R 12 represents an alkyl group having 1 carbon atom (methyl group). Comparative monomer 1 does not satisfy the above specific monomer because R 12 is an alkyl group having 1 carbon atom.

[0113] • Specific monomer 1: Methyl methacrylate represented by the above formula (1). Here, R 11 represents a methyl group, and R 12represents a linear alkyl group having 4 carbon atoms. Specific monomer 1 conforms to the above specific monomer.

[0114] • Specific monomer 2: methacrylate represented by the above formula (1). Here, R 11 represents a methyl group, and R 12 represents a linear alkyl group having 8 carbon atoms. Specific monomer 2 conforms to the above specific monomer.

[0115] • Specific monomer 3: methacrylate represented by the above formula (1). Here, R 11 represents a methyl group, and R 12 represents a linear alkyl group having 17 carbon atoms. Specific monomer 3 conforms to the above specific monomer.

[0116] • Comparative monomer 2: methacrylate represented by the above formula (1). Here, R 11 represents a methyl group, and R 12 represents an alkyl group having 23 carbon atoms. Comparative monomer 2 does not conform to the above specific monomer because R 12 is an alkyl group having 23 carbon atoms.

[0117] • Radical generator: t-butyl hydroperoxide

[0118] • Polyurethane: PANDEX 5205 (polyurethane, Mn: 25,000) manufactured by DIC Corporation

[0119] • Reducing agent: vanadium pentoxide

[0120] In Table 1, with respect to the monomers, "carbon atoms" represents the number of carbon atoms of the alkyl group represented by R 12 in formula (1). Further, in Table 1, "(meth)acrylate / polyurethane" represents the mass ratio of the total of the (meth)acrylate in the A agent and the (meth)acrylate in the B agent, to the polyurethane in the B agent.

[0121] As is clear from Table 1, Examples 1 to 9 each of which is composed of the A agent containing the specific monomer and the radical generator, and the B agent containing the specific monomer, the reducing agent, and the polyurethane, all show excellent adhesiveness.

[0122] According to the comparison of Examples 1 to 4 (comparison of the schemes in which the types of the specific monomers are different from each other), Examples 1 to 2 each of which is such that the number of carbon atoms of the specific monomer in the A agent and the B agent is 4 to 8, show more excellent adhesiveness. Among them, Example 1 in which the number of carbon atoms of the specific monomer in the A agent and the B agent is 4 to 6 shows further excellent adhesiveness.

[0123] Further, according to the comparison between Example 1 and Examples 5 to 9 (comparison between the cases where the specific monomer / polyurethane differs from each other), Examples 1 and 7 to 8 in which the specific monomer / polyurethane is 3 / 7 to 8 / 2 showed more excellent adhesiveness. Among them, Example 1 in which the specific monomer / polyurethane is 4 / 6 to 6 / 4 showed further excellent adhesiveness.

[0124] On the other hand, the adhesiveness was insufficient in Comparative Examples 1 and 2 in which the A agent did not contain the specific monomer, and Comparative Example 3 in which the B agent did not contain the polyurethane.

Claims

1. A two-component acrylic adhesive for vulcanized rubber, comprising agent A and agent B, Agent A contains (meth)acrylate and a free radical generator as shown in formula (1), and Agent B contains (meth)acrylate, a reducing agent, and polyurethane as shown in formula (1). CH2=C(R 11 )-CO-OR 12 (1) In equation (1), R 11 R represents a hydrogen atom or a methyl group. 12 Indicates alkyl groups having 4 to 17 carbon atoms. The content of the (meth)acrylate in agent A is 70% or more by mass relative to the total content of agent A. The content of the (meth)acrylate in agent B is 20% by mass or more relative to the total content of agent B. The total mass ratio of the (meth)acrylate in Agent A to the (meth)acrylate in Agent B, and the mass ratio of the (meth)acrylate in Agent B to the polyurethane in Agent B, is 3 / 7 to 8 / 2.

2. The two-component acrylic adhesive for vulcanized rubber according to claim 1, wherein the polyurethane has a number average molecular weight of 2,000 or more and 100,000 or less, and wherein the polyurethane is obtained by reacting a polyisocyanate with a polyol.

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