Adhesive composition for vulcanized rubber, and tire

Abstract

To provide an adhesive composition for vulcanized rubber having a good balance between an open assembly time and a closed assembly time.SOLUTION: An adhesive composition for vulcanized rubber comprises: an agent A that comprises an epoxy resin comprising a plurality of epoxy groups in one molecule; and an agent B that comprises a polyamide comprising a plurality of primary amino groups in one molecule and having an amine value of 200-350 mgKOH / g, and an unsaturated fatty acid. There is also provided a tire comprising a vulcanized tire and a part bonded using the adhesive composition for vulcanized rubber.SELECTED DRAWING: None

Description

Technical Field

[0001] The present invention relates to an adhesive composition for vulcanized rubber and a tire.

Background Art

[0002] Conventionally, an adhesive composition containing an epoxy resin or the like is known (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In recent years, there is a system that uses IoT (Internet of Things) to monitor information (for example, air pressure, etc.) of tires mounted on automobiles. In the above system, a tire has a container (container) inside that houses devices such as a sensor (detector) for monitoring tire information. Usually, the above container is fixed to the tire with an adhesive. Under such circumstances, the inventors prepared an adhesive composition with reference to Patent Document 1, applied the adhesive composition to the surface of a vulcanized tire, and adhered a component (for example, a rubber container for housing a sensor). As a result, it became clear that the balance between the open assembly time and the closed assembly time may be poor. The open assembly time refers to the time it takes for the viscosity of the mixture of liquid A and liquid B of a two-component adhesive composition to become twice the initial viscosity of the mixture immediately after mixing. The open assembly time is a period during which the viscosity is stable. The closed assembly time is when the adhesive strength of the mixture becomes 0.5 kgf / cm from when the viscosity of the mixture of liquid A and liquid B becomes twice the initial viscosity2 Refers to the time taken until it becomes [a certain state]. That is, the closed door assembly time is the time until curing starts and initial adhesive strength is exhibited.

[0005] Therefore, in view of the above circumstances, an object of the present invention is to provide an adhesive composition for vulcanized rubber with an excellent balance between open assembly time and closed door assembly time. Another object of the present invention is to provide a tire with parts adhered.

Means for Solving the Problems

[0006] As a result of intensive research to solve the above problems, the inventors of the present invention have found that the adhesive composition has Agent A containing an epoxy resin having a plurality of epoxy groups in one molecule, and Agent B containing a polyamide having a plurality of primary amino groups in one molecule, with an amine value of 200 to 350 mgKOH / g, and an unsaturated fatty acid, and have found that a desired effect can be obtained, thus arriving at the present invention. The present invention is based on the above findings and the like, and specifically solves the above problems with the following configuration.

[0007] [1] An adhesive composition for vulcanized rubber, comprising Agent A containing an epoxy resin having a plurality of epoxy groups in one molecule, and Agent B containing a polyamide having a plurality of primary amino groups in one molecule, with an amine value of 200 to 350 mgKOH / g, and an unsaturated fatty acid. [2] The adhesive composition for vulcanized rubber according to [1], wherein the epoxy resin contains at least one selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and dimer acid-modified epoxy resin. [3] The adhesive composition for vulcanized rubber according to [1] or [2], wherein the unsaturated fatty acid contains oleic acid and / or linolenic acid. [4] The vulcanized rubber adhesive composition according to any one of [1] to [3], wherein the content of the unsaturated fatty acid is 0.1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the epoxy resin. [5] The vulcanized rubber adhesive composition according to any one of [1] to [4], wherein the content of the polyamide is 20 to 100 parts by mass with respect to 100 parts by mass of the epoxy resin. [6] A tire in which a vulcanized tire and a component are adhered with the vulcanized rubber adhesive composition according to any one of [1] to [5]. [7] The tire according to [6], wherein the component is a rubber container incorporating a sensor. [Advantages of the Invention]

[0008] According to the present invention, it is possible to provide a vulcanized rubber adhesive composition having an excellent balance between open assembly time and closed assembly time. Further, the present invention can also provide a tire having a component adhered thereto. [Embodiments for Carrying Out the Invention]

[0009] The present invention will be described in detail below. In this specification, a numerical range represented by "~" means a range including the numerical values described before and after "~" as a lower limit value and an upper limit value. In this specification, unless otherwise specified, each component can be used alone or in combination of two or more of the substances corresponding to the component. When a component contains two or more substances, the content of the component means the total content of the two or more substances. In this specification, unless otherwise specified, each component is not particularly limited with respect to its production method. For example, conventionally known methods can be mentioned. In this specification, sometimes the balance between open assembly time and closed assembly time being more excellent is referred to as the effect of the present invention being more excellent.

[0010] [Adhesive composition for vulcanized rubber] The adhesive composition for vulcanized rubber (the adhesive composition of the present invention) of the present invention comprises: (Agent A) containing an epoxy resin having a plurality of epoxy groups in one molecule, and (Agent B) containing a polyamide having a plurality of primary amino groups in one molecule, having an amine value of 200 to 350 mgKOH / g, and an unsaturated fatty acid, and is an adhesive composition for vulcanized rubber. Hereinafter, each component contained in the adhesive composition of the present invention will be described in detail.

[0011] [Agent A] In the present invention, Agent A contains an epoxy resin having a plurality of epoxy groups in one molecule.

[0012] [Epoxy resin] In the present invention, the epoxy resin contained in Agent A is a compound having a plurality of epoxy groups in one molecule.

[0013] (Specific examples) Examples of the epoxy resin include bisphenol polyglycidyl ether type epoxy resins such as bisphenol A type epoxy resin, bisphenol B type epoxy resin, bisphenol C type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol AD type epoxy resin, and bisphenol S type epoxy resin; hydrogenated bisphenol type diglycidyl ether (for example, hydrogenated bisphenol A type epoxy resin); novolak type epoxy compounds such as phenol novolak type epoxy resin, biphenyl novolak type epoxy compound, cresol novolak type epoxy compound, and bisphenol A novolak type epoxy compound; naphthalene type epoxy resin, biphenyl type epoxy resin; and dimer acid modified epoxy resin.

[0014] From the viewpoint of more excellent effects of the present invention and excellent adhesiveness to vulcanized rubber, the epoxy resin preferably contains at least one selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and dimer acid modified epoxy resin. Further, from the viewpoint that the epoxy resin has more excellent effects of the present invention and excellent adhesiveness to vulcanized rubber, it is preferably liquid at normal temperature (23°C). Examples of the epoxy resin that is liquid at normal temperature include bisphenol A type epoxy resin, bisphenol F type epoxy resin, and dimer acid-modified epoxy resin.

[0015] (Weight average molecular weight) From the viewpoint that the effects of the present invention are more excellent and the adhesiveness to vulcanized rubber is excellent, the weight average molecular weight of the above epoxy resin is preferably 200 or more and less than 700. The weight average molecular weight of the epoxy resin can be a standard polystyrene conversion value by gel permeation chromatography using tetrahydrofuran (THF) as a solvent.

[0016] [Agent B] In the present invention, Agent B contains a polyamide having a plurality of primary amino groups in one molecule and an amine value of 200 to 350 mgKOH / g, and an unsaturated fatty acid.

[0017] [Polyamide] In the present invention, the polyamide contained in Agent B has a plurality of primary amino groups in one molecule, and the amine value of the above polyamide is 200 to 350 mgKOH / g.

[0018] [Primary amino group] The above polyamide has a plurality of primary amino groups (-NH2) per molecule. From the viewpoint that the effects of the present invention are more excellent and the adhesiveness to vulcanized rubber is more excellent, it preferably has an average of 2 to 3 primary amino groups per molecule.

[0019] [Amine value] From the viewpoint that the effects of the present invention are more excellent and the adhesiveness to vulcanized rubber is more excellent, the amine value of the above polyamide is preferably 240 to 300 mgKOH / g. The amine value of the polyamide can be measured in accordance with JIS K7237-1995.

[0020] The main chain of the above polyamide is not particularly limited as long as it is a polymer having a plurality of amide bonds.

[0021] From the viewpoint that the effects of the present invention are more excellent and the adhesiveness to vulcanized rubber is excellent, the weight average molecular weight of the above polyamide is preferably 10,000 to 30,000. The weight average molecular weight of the polyamide can be a standard polystyrene conversion value obtained by gel permeation chromatography (GPC) measurement.

[0022] (Content of polyamide) From the viewpoint that the effects of the present invention are more excellent and the adhesiveness to vulcanized rubber is excellent, the content of the above polyamide is preferably 20 to 100 parts by mass with respect to 100 parts by mass of the above epoxy resin.

[0023] [Unsaturated fatty acid] In the present invention, the unsaturated fatty acid contained in Agent B is a compound having an unsaturated aliphatic hydrocarbon group and a carboxy group. In the present invention, the unsaturated fatty acid has a catalytic function of promoting the reaction between the epoxy group of the epoxy resin and the primary amino group of the above polyamide, but does not act on the above reaction during the open assembly time, and is considered to exhibit the above function at the closed assembly time.

[0024] The unsaturated fatty acid can have one or more unsaturated bonds per molecule, and preferably has one unsaturated bond. The unsaturated fatty acid can have one or more carboxy groups per molecule, and preferably has one carboxy group. The number of carbon atoms of the aliphatic hydrocarbon group of the unsaturated fatty acid is preferably 10 to 30.

[0025] Examples of unsaturated fatty acids include monounsaturated fatty acids such as myristoleic acid, palmitoleic acid, oleic acid, and elaidic acid; diunsaturated fatty acids such as linoleic acid; and triunsaturated fatty acids such as linolenic acid.

[0026] Unsaturated fatty acids preferably contain oleic acid and / or linolenic acid because the effects of the present invention are more excellent and the adhesiveness to vulcanized rubber is excellent.

[0027] (Content of unsaturated fatty acid) The content of unsaturated fatty acids is preferably 0.1 part by mass or more and 10 parts by mass or less, more preferably 2.0 to 10 parts by mass, based on 100 parts by mass of the above epoxy resin, because the effects of the present invention are more excellent and the adhesiveness to vulcanized rubber is excellent.

[0028] (Optional components) The adhesive composition of the present invention may further contain components other than the above-described components (optional components). Examples of optional components include plasticizers, fillers, balloons (hollow bodies), silane coupling agents, anti-aging agents, antioxidants, solvents, and thixotropic agents. It can be appropriately selected whether to add each optional component to either one or both of Agent A and Agent B.

[0029] ·Filler The adhesive composition of the present invention preferably further contains a filler because the effects of the present invention are more excellent and the adhesiveness to vulcanized rubber is excellent. Examples of fillers include carbon black, silica, mica, calcium carbonate, magnesium carbonate, diatomaceous earth, clay, talc, titanium oxide, and ferric oxide. The filler may be surface-treated with, for example, fatty acids or fatty acid esters. The filler preferably contains calcium carbonate because the effects of the present invention are more excellent and the adhesiveness to vulcanized rubber is excellent.

[0030] ·Content When the adhesive composition of the present invention further contains a filler, the total content of the filler in the adhesive composition is preferably 50 to 150 parts by mass with respect to 100 parts by mass of the epoxy resin, because the effects of the present invention are more excellent and the adhesiveness to vulcanized rubber is excellent.

[0031] (Two-component adhesive composition) The adhesive composition of the present invention is a two-component composition having Agent A and Agent B.

[0032] [Manufacturing method] The method for manufacturing the adhesive composition of the present invention is not particularly limited. For example, a two-component adhesive composition can be manufactured by putting the components used for Agent A and Agent B into separate containers and mixing each container under a nitrogen gas atmosphere. When using the adhesive composition of the present invention, Agent A and Agent B may be mixed and used.

[0033] [Applications] The adhesive composition of the present invention is useful as an adhesive for fixing another material (for example, a rubber container for housing equipment) to a vulcanized rubber (for example, a tire (especially an inner liner)).

[0034] [Usage] The adhesive composition of the present invention can be cured, for example, under the conditions of 5 to 40°C. When curing the adhesive composition of the present invention, it is not necessary to heat the adhesive composition of the present invention. As a method of using the adhesive composition of the present invention, the adhesive composition of the present invention is applied to a vulcanized rubber and / or another material, the two are bonded together, and, for example, placed under room temperature (for example, 5 to 40°C) conditions, whereby the adhesive composition of the present invention is cured and the two can be adhered.

[0035] [Tire] The tire of the present invention is a tire in which a vulcanized tire and a component are adhered with the adhesive composition for vulcanized rubber of the present invention.

[0036] [Vulcanized tire] The vulcanized tire used in the tire of the present invention is not particularly limited as long as it is a tire after vulcanization (vulcanized). 〔Adhesive composition〕 The adhesive composition used in the tire of the present invention is not particularly limited as long as it is an adhesive composition for vulcanized rubber of the present invention.

[0037] 〔Parts〕 Examples of the parts used in the tire of the present invention include a rubber container incorporating a sensor. (Container) The exterior of the above container is made of rubber. The rubber forming the above container is preferably vulcanized. The rubber forming the above container is not particularly limited. The rubber forming the above container preferably contains natural rubber as a rubber component. (Sensor) The sensor incorporated in the above container is not particularly limited. For example, sensors for the purpose of acquiring information such as the air pressure of the tire, the wear condition of the tire, and the road surface condition can be mentioned.

[0038] The above container is preferably adhered, for example, onto the inner liner of the tire.

Examples

[0039] The present invention will be specifically described below with reference to examples. However, the present invention is not limited thereto.

[0040] [Manufacture of adhesive composition] For each of Agent A and Agent B shown in Table 1, a two-component adhesive composition (Agent A, Agent B) was manufactured by mixing each component at the ratio (parts by mass) shown in the same table. When using the two-component adhesive composition, Liquid A and Liquid B were mixed.

[0041] [Evaluation] The following evaluations were performed using each of the adhesive compositions manufactured as described above. The results are shown in each table. 〔Measurement of open assembly time〕 The A liquid and the B liquid of the two - liquid type adhesive composition were mixed, and the viscosity of the mixture of the A liquid and the B liquid was measured using a B - type viscometer as a measuring device under the condition of 23°C. The time required for the viscosity of the mixture of the A liquid and the B liquid to become twice the initial viscosity of the mixture immediately after mixing was measured. In the present invention, the open assembly time may be 5 minutes or more and less than 30 minutes.

[0042] 〔Measurement of closed assembly time〕 After the open assembly time was measured as described above, the following evaluation of the closed assembly time was performed using each adhesive composition.

[0043] Vulcanized rubbers 1 and 2 were prepared in advance as follows. · Preparation of vulcanized rubber 1 From the components shown in the following "rubber composition for vulcanized rubber 1", the components excluding sulfur and vulcanization accelerator were kneaded in a 1.8 - L closed - type mixer for 5 minutes and then discharged to obtain a masterbatch. To the obtained masterbatch, sulfur and a vulcanization accelerator were added and mixed on an open roll to prepare a rubber composition for vulcanized rubber 1. Using the rubber composition for vulcanized rubber 1 prepared as described above, vulcanization was carried out at 170°C for 10 minutes in a mold of a predetermined shape to produce vulcanized rubber 1 (25 mm in width, 10 cm in length, 2 mm in thickness).

[0044] ((Rubber composition for vulcanized rubber 1)) · 100 parts by mass of halogenated butyl rubber (brominated isobutylene isoprene rubber, manufactured by Exxon Chemical Co., Ltd.) · 25 parts by mass of carbon black (Nitron #GN manufactured by Shin - Nippon Carbon Co., Ltd., N2SA is 35 m 2 / g · 3 parts by mass of zinc oxide (zinc oxide No. 3 manufactured by Sho - do Chemical Industry Co., Ltd.) · 3 parts by mass of sulfur (Sulfax 5 manufactured by Tsurumi Chemical Industry Co., Ltd.) · 2 parts by mass of vulcanization accelerator (DM - PO manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)

[0045] · Preparation of vulcanized rubber 2 From the components shown in the following "rubber composition for vulcanized rubber 2", the components excluding sulfur and vulcanization accelerator were kneaded in a 1.8 L closed mixer for 5 minutes and then discharged to obtain a masterbatch. The obtained masterbatch was mixed with sulfur and a vulcanization accelerator on an open roll to prepare a rubber composition for vulcanized rubber 2. Using the rubber composition for vulcanized rubber 2 prepared as described above, vulcanization was carried out at 170 °C for 10 minutes in a mold of a predetermined shape to produce vulcanized rubber 2 (width 25 mm, length 10 cm, thickness 2 mm).

[0046] ((Rubber composition for vulcanized rubber 2)) · 100 parts by mass of natural rubber · 25 parts by mass of carbon black (Nitron #GN manufactured by Shin-Nippon Chemical Co., Ltd., N2SA is 35 m 2 / g · 3 parts by mass of zinc oxide (zinc oxide type 3 manufactured by Shodo Chemical Industry Co., Ltd.) · 3 parts by mass of sulfur (Sulfax 5 manufactured by Tsurumi Chemical Industry Co., Ltd.) · 2 parts by mass of vulcanization accelerator (DM-PO manufactured by Ouchi Shinko Chemical Industry Co., Ltd.)

[0047] · Preparation of test specimens ·· Application process Each adhesive composition manufactured as described above was applied to the above-mentioned vulcanized rubber 1 (application amount: 2 to 5 g / cm 2 ), and laminated with the above-mentioned vulcanized rubber 2 to obtain a laminate.

[0048] ·· Curing process Each laminate obtained as described above was cured by placing it under the conditions of 25 °C and 50% relative humidity to obtain a test specimen having an adhesive layer (thickness 1 mm) made of an adhesive composition between vulcanized rubbers 1 and 2.

[0049] · Tensile test Using each test specimen obtained as described above, in accordance with JIS K6250:2019, the T-peel adhesive strength was measured under the conditions of 25 °C and a tensile speed of 50 mm / min. After laminating vulcanized rubber 1 and vulcanized rubber 2, the time until the adhesive strength reached 0.5 kgf / cm 2 was measured.

[0050] · Evaluation criteria From the measurement results of the open assembly time (OAT) and the closed assembly time (CAT) measured as described above, the balance between the open assembly time and the closed assembly time was evaluated according to the following criteria. In the present invention, when the open assembly time is 5 minutes or more and less than 30 minutes, and the value of CAT / OAT is 1.0 or less, it was evaluated that the balance between the open assembly time and the closed assembly time is excellent. In addition, when the open assembly time is shorter within the above range, or when the value of CAT / OAT is 0.3 to 0.8, it was evaluated that the balance between the open assembly time and the closed assembly time is more excellent. On the other hand, when the open assembly time is less than 5 minutes or 30 minutes or more, or when the value of CAT / OAT exceeds 1.0, it was evaluated that the balance between the open assembly time and the closed assembly time is poor.

[0051] [Table 1]

[0052] The details of each component shown in Table 1 are as follows. · Epoxy resin 1: Bisphenol A type epoxy resin. Epicoat 828, manufactured by JER. Weight average molecular weight 380, epoxy equivalent 190 g / eq · Epoxy resin 2: Dimer acid modified epoxy resin. EPU-16B, manufactured by ADEKA. Weight average molecular weight 450, epoxy equivalent 225 g / eq

[0053] · Filler 1: Heavy calcium carbonate. Super S, manufactured by Maruo Calcium Co., Ltd. · Fillers 2 and 3: Surface-treated calcium carbonate. Calfine 200, manufactured by Maruo Calcium Co., Ltd. · Filler 4: Dry silica. Trade name R923, manufactured by Nippon Aerosil Co., Ltd.

[0054] · Polyamide 1 (with primary amino group): A dimer acid-modified polyamide having two primary amino groups in one molecule. Trade name: Tomide RS640, manufactured by T&K TOKA Co., Ltd. Amine value: 270 mg KOH / g

[0055] · Polyamide 2 (with primary amino group): A dimer acid-modified polyamide having a primary amino group. Trade name: Tomide 296, manufactured by T&K TOKA Co., Ltd. Amine value: 430 mg KOH / g · Polyamine (without amide bond): A polyamine having two primary amino groups in one molecule and a hydrocarbon group as the main skeleton. Trade name: Tetraethylenepentamine, manufactured by Wako Pure Chemical Industries, Ltd. Amine value: 1310 mg KOH / g

[0056] · Unsaturated fatty acid 1: Oleic acid, manufactured by Wako Pure Chemical Industries, Ltd. · Unsaturated fatty acid 2: Linolenic acid, manufactured by Wako Pure Chemical Industries, Ltd.

[0057] · Triethylamine: manufactured by Wako Pure Chemical Industries, Ltd. · 2-Ethylhexanoic acid: manufactured by Wako Pure Chemical Industries, Ltd.

[0058] As is clear from the results shown in Table 1, Comparative Example 1, which does not contain an unsaturated fatty acid, had a poor balance between the open assembly time and the closed assembly time. Comparative Examples 2 to 4, which do not contain an unsaturated fatty acid but instead contain triethylamine, also had a poor balance. Comparative Example 5, which does not contain an unsaturated fatty acid but instead contains 2-ethylhexanoic acid, had a short open assembly time and a poor balance. Comparative Example 6, which contains a polyamide with an amine value exceeding 350 mg KOH / g, had a short open assembly time and a poor balance. Comparative Example 7, which contains a polyamine (without amide bond) with an amine value exceeding 350 mg KOH / g, had a long open assembly time and a poor balance.

[0059] On the other hand, the adhesive composition of the present invention had an excellent balance between the open assembly time and the closed assembly time.

Claims

1. Agent A containing an epoxy resin having a plurality of epoxy groups in one molecule, and Agent B containing a polyamide having a plurality of primary amino groups in one molecule and an amine value of 200 to 350 mg KOH / g, and an unsaturated fatty acid, an adhesive composition for vulcanized rubber.

2. The adhesive composition for vulcanized rubber according to claim 1, wherein the epoxy resin contains at least one selected from the group consisting of bisphenol A type epoxy resin, bisphenol F type epoxy resin, and dimer acid-modified epoxy resin.

3. The adhesive composition for vulcanized rubber according to claim 1 or 2, wherein the unsaturated fatty acid contains oleic acid and / or linolenic acid.

4. The adhesive composition for vulcanized rubber according to any one of claims 1 to 3, wherein the content of the unsaturated fatty acid is 0.1 part by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the epoxy resin.

5. The adhesive composition for vulcanized rubber according to any one of claims 1 to 4, wherein the content of the polyamide is 20 to 100 parts by mass with respect to 100 parts by mass of the epoxy resin.

6. A tire in which a vulcanized tire and a component are adhered with the adhesive composition for vulcanized rubber according to any one of claims 1 to 5.

7. The tire according to claim 6, wherein the component is a rubber container incorporating a sensor.

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