Epoxy resin-based adhesive composition

Abstract

To provide an epoxy resin-based adhesive composition capable of enhancing vibration damping performance of an adhesive layer used in a vehicle.SOLUTION: The epoxy resin-based adhesive composition for use in a vehicle contains a bisphenol A type epoxy resin, a polyalkylene glycol diglycidyl ether, a dimer acid diglycidyl ester, and a compound having a phenolic group.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to an epoxy resin adhesive composition. [Background technology]

[0002] Patent Document 1 describes an adhesive structure having an adhesive layer. The adhesive layer can be made of, for example, an epoxy resin adhesive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2018-069658 Summary of the Invention [Problem to be solved by the invention]

[0004] In vehicles such as automobiles, for example, it is sometimes desirable to have a structure that suppresses vibrations in order to improve the ride comfort of the vehicle. For example, it is sometimes desirable to improve the vibration damping performance of the adhesive layer that constitutes the adhesive structure in the vehicle.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an epoxy resin adhesive composition that can improve the vibration damping performance of adhesive layers in vehicles. [Means for solving the problem]

[0006] The epoxy resin adhesive composition that solves the above problems is an epoxy resin adhesive composition for use in vehicles, and contains a bisphenol A type epoxy resin, a polyalkylene glycol diglycidyl ether, a dimer acid diglycidyl ester, and a compound having a phenol group.

[0007] In the epoxy resin adhesive composition, the content of the polyalkylene glycol diglycidyl ether may be within a range of 10 parts by mass or more and 60 parts by mass or less, relative to 100 parts by mass of the bisphenol A type epoxy resin; the content of the dimer acid diglycidyl ester may be within a range of 10 parts by mass or more and 60 parts by mass or less, relative to 100 parts by mass of the bisphenol A type epoxy resin; the total content of the polyalkylene glycol diglycidyl ether and the dimer acid diglycidyl ester may be within a range of 40 parts by mass or more and 90 parts by mass or less, relative to 100 parts by mass of the bisphenol A type epoxy resin; and the content of the compound having a phenol group may be within a range of 50 parts by mass or more and 90 parts by mass or less, relative to 100 parts by mass of the bisphenol A type epoxy resin.

[0008] In the epoxy resin adhesive composition, the content of the polyalkylene glycol diglycidyl ether may be within a range of 20 parts by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the bisphenol A type epoxy resin; the content of the dimer acid diglycidyl ester may be within a range of 20 parts by mass or more and 50 parts by mass or less, relative to 100 parts by mass of the bisphenol A type epoxy resin; the total content of the polyalkylene glycol diglycidyl ether and the dimer acid diglycidyl ester may be within a range of 50 parts by mass or more and 80 parts by mass or less, relative to 100 parts by mass of the bisphenol A type epoxy resin; and the content of the compound having a phenol group may be within a range of 60 parts by mass or more and 80 parts by mass or less, relative to 100 parts by mass of the bisphenol A type epoxy resin. [Effects of the Invention]

[0009] The present invention exhibits the effect of making it possible to improve the vibration damping performance of adhesive layers in vehicles. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the epoxy resin adhesive composition will be described. The epoxy resin adhesive composition for use in vehicles contains a bisphenol A epoxy resin, a polyalkylene glycol diglycidyl ether, a dimer acid diglycidyl ester, and a compound having a phenol group. The epoxy resin adhesive composition may contain a curing agent, a curing accelerator, core-shell rubber particles, a block urethane resin, etc., as needed.

[0011] <Bisphenol A epoxy resin> Commercially available bisphenol A epoxy resins can be used. The bisphenol A epoxy resins may be solid resins that are solid at room temperature, or liquid resins that are liquid at room temperature. Only one type of bisphenol A epoxy resin may be used, or two or more types may be used in combination. The bisphenol A epoxy resin is preferably a liquid resin that is liquid at room temperature. The room temperature is, for example, 20°C ± 15°C. Commercially available bisphenol A epoxy resins include "Product Name: NPEL-128" manufactured by Nan Ya Plastics Co., Ltd., "Product Name: jER828" manufactured by Mitsubishi Chemical Corporation, "YD-128" manufactured by Nippon Steel Chemical & Material Co., Ltd., and "Product Name: EPICLON 850" manufactured by DIC Corporation.

[0012] <Polyalkylene glycol diglycidyl ether> Examples of polyalkylene glycol diglycidyl ethers include polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, polytetramethylene glycol diglycidyl ether, etc. The polyalkylene glycol diglycidyl ethers may be used alone or in combination of two or more.

[0013] <Dimer acid diglycidyl ester> Dimer acid diglycidyl ester is a divalent epoxy polymer obtained by reacting dimer acid with epichlorohydrin. Dimer acid is a dicarboxylic acid produced by dimerization of unsaturated fatty acid. The number of carbon atoms of the unsaturated fatty acid is, for example, 18. Examples of unsaturated fatty acids include oleic acid and linoleic acid. Commercially available dimer acid diglycidyl esters can be used.

[0014] <Compounds containing a phenol group> Examples of compounds having a phenol group include alkylphenols, alkenylphenols, distyrenated phenols, methylstyrenated phenols, and phenol resins. The alkyl group of the alkylphenol has, for example, 1 to 20 carbon atoms. The alkyl group may be linear or branched. Examples of alkenylphenols include cardanol and cardanol oligomers. Examples of phenol resins include resol resins and novolac resins. Only one type of compound having a phenol group may be used, or two or more types may be used in combination.

[0015] <Content of the above ingredients> The content of the polyalkylene glycol diglycidyl ether in the epoxy resin adhesive composition is preferably in the range of 10 parts by mass or more and 60 parts by mass or less, and more preferably in the range of 20 parts by mass or more and 50 parts by mass or less, per 100 parts by mass of the bisphenol A type epoxy resin.

[0016] The content of the dimer acid diglycidyl ester in the epoxy resin adhesive composition is preferably in the range of 10 parts by mass or more and 60 parts by mass or less, and more preferably in the range of 20 parts by mass or more and 50 parts by mass or less, per 100 parts by mass of the bisphenol A type epoxy resin.

[0017] The total content of the polyalkylene glycol diglycidyl ether and dimer acid diglycidyl ester in the epoxy resin adhesive composition is preferably in the range of 40 parts by mass or more and 90 parts by mass or less, and more preferably in the range of 50 parts by mass or more and 80 parts by mass or less, per 100 parts by mass of the bisphenol A epoxy resin.

[0018] The content of the compound having a phenol group in the epoxy resin adhesive composition is preferably in the range of 50 parts by mass or more and 90 parts by mass or less, and more preferably in the range of 60 parts by mass or more and 80 parts by mass or less, per 100 parts by mass of the bisphenol A type epoxy resin.

[0019] The total content of the bisphenol A type epoxy resin, polyalkylene glycol diglycidyl ether, dimer acid diglycidyl ester, and compound having a phenol group in the epoxy resin adhesive composition is, for example, preferably 10% by mass or more, more preferably 15% by mass or more, and even more preferably 20% by mass or more.

[0020] The upper limit of the total content of the bisphenol A type epoxy resin, polyalkylene glycol diglycidyl ether, dimer acid diglycidyl ester, and compound having a phenol group in the epoxy resin adhesive composition is, for example, 95 mass % or less, 90 mass % or less, or 85 mass % or less.

[0021] <Curing agent> Examples of curing agents include hydrazides, amide compounds, aminocarboxylic acids, amine adducts, polyamines, etc. Examples of hydrazides include adipic acid dihydrazide, sebacic acid dihydrazide, dodecanediohydrazide, isophthalic acid dihydrazide, salicylic acid hydrazide, etc. Examples of amide compounds include dicyandiamide and polyamides, etc. Examples of aminocarboxylic acids include 6-aminohexanoic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, 12-aminolauric acid, etc. One type of curing agent may be used alone, or two or more types may be used in combination.

[0022] The curing agent preferably contains dicyandiamide. The content of the curing agent in the epoxy resin adhesive composition is preferably in the range of 8 parts by mass or more and 24 parts by mass or less, more preferably 10 parts by mass or more and 14 parts by mass or less, per 100 parts by mass of bisphenol A-type epoxy resin. When the content of this curing agent is 8 parts by mass or more, it is possible to further increase the adhesive strength. When the content of this curing agent is 24 parts by mass or less, it is possible to improve storage stability.

[0023] <Curing accelerator> Examples of the curing accelerator include urea-based curing accelerators and imidazole-based curing accelerators. Examples of the urea-based curing accelerator include monouron, diuron, isophorone bisurea, methylene diphenyl bisdimethylurea, phenyl dimethyl urea, and toluene bisdimethyl urea. Examples of the imidazole-based curing accelerator include 2-ethyl-4-methylimidazole, 2-phenylimidazole, 1-(2-cyanoethyl)-2-ethyl-4-methylimidazole, 2-phenylimidazoline, and 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-triazine isocyanuric acid adduct. Only one type of curing accelerator may be used, or two or more types may be used in combination.

[0024] The content of the curing accelerator in the epoxy resin adhesive composition is preferably in the range of 1 part by mass or more and 10 parts by mass or less, more preferably 3 parts by mass or more and 8 parts by mass or less, per 100 parts by mass of bisphenol A-type epoxy resin. When the content of this curing accelerator is 1 part by mass or more, it is possible to further increase the adhesive strength. When the content of this curing accelerator is 10 parts by mass or less, it is possible to improve storage stability.

[0025] <Core-shell rubber particles> The core-shell rubber particles have a core layer made of rubber and a shell layer covering the outer periphery of the core layer. Examples of the core layer of the core-shell rubber particles include olefin rubber, butadiene rubber, urethane rubber, acrylic rubber, and silicone rubber. Examples of the shell layer of the core-shell rubber particles include acrylic resin and styrene resin. Only one type of core-shell rubber particle may be used, or two or more types may be used in combination.

[0026] The content of the core-shell rubber particles in the epoxy resin adhesive composition is preferably in the range of 10 parts by mass or more and 100 parts by mass or less, and more preferably in the range of 20 parts by mass or more and 60 parts by mass or less, per 100 parts by mass of bisphenol A-type epoxy resin. When the content of the core-shell rubber particles is 10 parts by mass or more, the strength of the adhesive layer can be further increased. When the content of the core-shell rubber particles is 100 parts by mass or less, the storage stability can be improved.

[0027] <Block urethane resin> The blocked urethane resin is a resin obtained by blocking, with a blocking agent, polyurethane obtained by reacting a polyhydroxy compound with an excess amount of a polyisocyanate compound.

[0028] Examples of polyhydroxy compounds include polyether diols, polyether triols, polytetramethylene ether glycols, polyester polyols, and polycarbonate diols.

[0029] Examples of polyisocyanate compounds include hexane diisocyanate, hexane diisocyanate polymers, toluene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate (monomeric, polymeric, hydrogenated), isophorone diisocyanate, and the like.

[0030] Examples of blocking agents include monohydric alcohols (ethanol, propanol, butanol, pentanol, etc.), phenol, nonylphenol, p-tert-butylphenol, methyl ethyl ketone oxime, ε-caprolactam, etc. One type of blocking agent may be used alone, or two or more types may be used in combination.

[0031] The content of the block urethane resin in the epoxy resin adhesive composition is preferably in the range of 10 parts by mass or more and 60 parts by mass or less, and more preferably in the range of 20 parts by mass or more and 50 parts by mass or less, per 100 parts by mass of the bisphenol A epoxy resin. When the content of this block urethane resin is 10 parts by mass or more, it is possible to further increase the adhesive strength. When the content of this block urethane resin is 60 parts by mass or less, it is possible to suppress a decrease in the elastic modulus.

[0032] <Filler> Examples of fillers include calcium carbonate, silica, glass beads, milled glass fiber, talc, kaolin, bentonite, wollastonite, mica, calcium oxide, and minerals. Examples of calcium carbonate include heavy calcium carbonate and light calcium carbonate. Examples of the shape of the filler include spherical, plate-like, needle-like, and scaly shapes. The filler may be a surface-treated product obtained by treating the surface of the exemplified substance. Only one type of filler may be used, or two or more types may be used in combination.

[0033] The content of the filler in the epoxy resin adhesive composition is preferably in the range of 300 parts by mass or more and 600 parts by mass or less, and more preferably 400 parts by mass or more and 500 parts by mass or less, per 100 parts by mass of bisphenol A epoxy resin. When the content of this filler is 300 parts by mass or more, it is possible to further suppress the fluidity of the coating layer formed by applying the epoxy resin adhesive composition. When the content of this filler is 600 parts by mass or less, it is possible to suppress a decrease in the coatability of the epoxy resin adhesive composition.

[0034] <Method for producing and method for using epoxy resin adhesive composition> Next, an example of a method for producing and using the epoxy resin adhesive composition will be described.

[0035] The epoxy resin adhesive composition can be prepared by mixing the above-mentioned raw materials. A mixing device can be used to prepare the epoxy resin adhesive composition. Examples of the mixing device include a bead mill, a crusher, a pot mill, a three-roll mill, a rotary mixer, and a twin-screw mixer.

[0036] To use the epoxy resin adhesive composition, a coating step is first performed in which the epoxy resin adhesive composition is applied to a first panel, which is a component of a vehicle. For example, a coating gun can be used to apply the epoxy resin adhesive composition. Next, a second panel, which is a component of a vehicle, is placed on the coated layer of the epoxy resin adhesive composition provided on the first panel. This results in a laminated structure having the first panel, the second panel, and the coated layer sandwiched between the first panel and the second panel. The first panel and the second panel are, for example, metal panels. Examples of metal panels include steel plates and aluminum plates. Examples of steel plates include carbon steel plates and stainless steel plates. Examples of the first panel and the second panel include panels that constitute the undercarriage of a vehicle. The first panel and the second panel can also be joined by a joint such as spot welding, if necessary.

[0037] Next, the vehicle having the laminated structure is subjected to a cleaning process, an electrodeposition coating process, and a baking process, in that order. Here, the baking process is a process in which the electrodeposition coating film is baked using a heating furnace. This baking process is used to heat and harden the coating layer of the laminated structure, thereby obtaining an adhesive layer formed by the hardened coating layer. The adhesive layer in the laminated structure is disposed between the first panel and the second panel, and adheres the first panel and the second panel. The heating temperature in the baking process is, for example, in the range of 140°C or higher and 220°C or lower, and the heating time is, for example, in the range of 20 minutes or higher and 60 minutes or lower.

[0038] <Actions and Effects of This Embodiment> Next, the operation and effects of this embodiment will be described. (1) An epoxy resin adhesive composition for use in vehicles contains a bisphenol A-type epoxy resin, a polyalkylene glycol diglycidyl ether, a dimer acid diglycidyl ester, and a compound having a phenol group. This configuration makes it possible to improve the vibration damping performance of the adhesive layer in a vehicle. The vibration damping performance of the adhesive layer can be confirmed, for example, by measuring the dynamic viscoelasticity of the adhesive layer. In measuring the dynamic viscoelasticity of the adhesive layer, the vibration damping performance of the adhesive layer can be determined to be higher, for example, as the loss tangent (tanδ) value at 23°C and the loss tangent (tanδ) value at 40°C are larger.

[0039] (2) The content of the polyalkylene glycol diglycidyl ether in the epoxy resin adhesive composition is preferably in the range of 10 parts by mass or more and 60 parts by mass or less per 100 parts by mass of the bisphenol A epoxy resin. The content of the dimer acid diglycidyl ester in the epoxy resin adhesive composition is preferably in the range of 10 parts by mass or more and 60 parts by mass or less per 100 parts by mass of the bisphenol A epoxy resin. The total content of the polyalkylene glycol diglycidyl ether and the dimer acid diglycidyl ester in the epoxy resin adhesive composition is preferably in the range of 40 parts by mass or more and 90 parts by mass or less per 100 parts by mass of the bisphenol A epoxy resin. The content of the compound having a phenol group in the epoxy resin adhesive composition is preferably in the range of 50 parts by mass or more and 90 parts by mass or less per 100 parts by mass of the bisphenol A epoxy resin. In this case, it is possible to further improve the vibration damping performance of the adhesive layer in a vehicle.

[0040] (3) The content of the polyalkylene glycol diglycidyl ether in the epoxy resin adhesive composition is more preferably in the range of 20 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the bisphenol A epoxy resin. The content of the dimer acid diglycidyl ester in the epoxy resin adhesive composition is more preferably in the range of 20 parts by mass or more and 50 parts by mass or less per 100 parts by mass of the bisphenol A epoxy resin. The total content of the polyalkylene glycol diglycidyl ether and the dimer acid diglycidyl ester in the epoxy resin adhesive composition is more preferably in the range of 50 parts by mass or more and 80 parts by mass or less per 100 parts by mass of the bisphenol A epoxy resin. The content of the compound having a phenol group in the epoxy resin adhesive composition is more preferably in the range of 60 parts by mass or more and 80 parts by mass or less per 100 parts by mass of the bisphenol A epoxy resin. In this case, it is possible to further improve the vibration damping performance of the adhesive layer in a vehicle. [Example]

[0041] Next, examples and comparative examples will be described. (Examples 1 to 23 and Comparative Examples 1 to 3) The epoxy resin adhesive compositions of each Example and Comparative Example were prepared by kneading the raw materials and other ingredients shown in Tables 1 to 3 using a kneader. The units of the values ​​indicating the amounts of raw materials in Tables 1 to 3 are parts by mass. The epoxy resin adhesive compositions of each Example and Comparative Example contained a curing agent, a curing accelerator, and a filler as other ingredients. In the epoxy resin adhesive compositions of each Example and Comparative Example, the amount of curing agent was 12 parts by mass, the amount of curing accelerator was 6 parts by mass, and the amount of filler was 400 parts by mass.

[0042] Details of the raw materials in Tables 1 to 3 are as follows: (A) As the bisphenol A type epoxy resin, "Product name: NPEL-128" manufactured by Nan Ya Plastics Industry Co., Ltd. was used.

[0043] As the (B) polyalkylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether (manufactured by Kyoeisha Chemical Co., Ltd., trade name: Epolite 400E) was used.

[0044] (C) As the diglycidyl ester of dimer acid, "ERISYS GS-120" manufactured by Huntsman was used. (D) As the compound having a phenol group, distyrenated phenol (trade name: KUMANOX 3112, manufactured by Kumho Petrochemical Co., Ltd.) was used. Note that, as the distyrenated phenol, for example, "trade name: DSP" manufactured by Yokkaichi Synthetic Co., Ltd. can also be used.

[0045] Dicyandiamide (Huntsman, trade name: Omicure DDA5) was used as a curing agent, which is another compounding component mentioned above. As the curing accelerator, which is another compounding component, diuron (manufactured by Alzchem, trade name: UR200) ​​was used.

[0046] As the filler, which is another compounding component, heavy calcium carbonate (manufactured by Shimizu Kogyo Co., Ltd., trade name: LW-350) was used. (Dynamic viscoelasticity measurement) The epoxy resin adhesive composition of Example 1 was applied to a first steel plate. A 2 mm thick spacer was placed on the first steel plate, and then a second steel plate was placed on top of the first steel plate to obtain a laminate. The resulting laminate was heated at 170°C for 30 minutes. This cured the epoxy resin adhesive composition, thereby obtaining a bonded structure with an adhesive layer. A sample of the adhesive layer measuring 40 mm in length, 6 mm in width, and 2 mm in thickness was obtained from the resulting bonded structure.

[0047] The dynamic viscoelasticity of the obtained sample was measured using a dynamic viscoelasticity measuring device (manufactured by Hitachi High-Tech Science Corporation, product name: DMA7100) under the following measurement conditions. Deformation mode: Tensile mode (sine wave) Frequency: 1Hz Chuck distance: 20mm Amplitude: 10μm Measurement temperature: -20℃~100℃ Heating rate: 1℃ / min For each of the epoxy resin adhesive compositions of Examples 2 to 23 and Comparative Examples 1 to 3, samples were prepared in the same manner as in Example 1, and the dynamic viscoelasticity was measured.

[0048] (Vibration damping performance evaluation 1) From the loss tangent (tan δ) value (23° C.) obtained by the above viscoelasticity measurement, Evaluation 1 of vibration damping property was carried out according to the following criteria. The results of Evaluation 1 of vibration damping performance are shown in Tables 1 to 3.

[0049] Excellent (a): The loss tangent (tan δ) at 23°C is 0.13 or more. Good (b): The loss tangent (tan δ) at 23° C. is 0.1 or more and less than 0.13.

[0050] Poor (c): The loss tangent (tan δ) at 23°C is less than 0.1. (Vibration damping performance evaluation 2) From the loss tangent (tan δ) value (40° C.) obtained by the above viscoelasticity measurement, Evaluation 2 of vibration damping property was carried out according to the following criteria. The results of Evaluation 2 of vibration damping performance are shown in Tables 1 to 3.

[0051] Excellent (a): The loss tangent (tan δ) at 40°C is 0.4 or more. Good (b): The loss tangent (tan δ) at 40° C. is 0.3 or more and less than 0.4. Poor (c): The loss tangent (tan δ) at 40°C is less than 0.3.

[0052] [Table 1]

[0053] [Table 2]

[0054] [Table 3]

[0055] As shown in Tables 1 to 3, Examples 1 to 23 obtained excellent or good results in vibration damping performance evaluations 1 and 2. In contrast, Comparative Example 1, which did not contain polyalkylene glycol diglycidyl ether, obtained results inferior to Examples 1 to 23 in vibration damping performance evaluations 1 and 2. Comparative Example 2, which did not contain dimer acid diglycidyl ester, and Comparative Example 3, which did not contain a compound having a phenol group, also obtained results inferior to Examples 1 to 23.

[0056] In Examples 4 to 7, Examples 12 to 15, Example 21, and Example 22, excellent results were obtained in both Evaluation 1 and Evaluation 2 of vibration damping performance. (Study 1-1: Study of polyalkylene glycol diglycidyl ether) A sample was prepared in the same manner as in Examples 1 to 23, and dynamic viscoelasticity was measured, except that the polyethylene glycol diglycidyl ether used in Examples 1 to 23 was changed to a polyethylene glycol diglycidyl ether (trade name: Denacol EX-832, manufactured by Nagase ChemteX Corporation) made by a different manufacturer. Even in this case, results equivalent to those of Examples 1 to 23 were obtained for Evaluation 1 and Evaluation 2 of vibration damping performance.

[0057] (Study 1-2: Polyalkylene glycol diglycidyl ether) The polyethylene glycol diglycidyl ether used in Examples 1 to 23 was changed to polypropylene glycol diglycidyl ether (manufactured by Yokkaichi Synthetic Co., Ltd., product name: Epogose-PG400). Apart from this change, samples were prepared in the same manner as in Examples 1 to 23, and dynamic viscoelasticity was measured. Even in this case, results equivalent to those of Examples 1 to 23 were obtained for Evaluation 1 and Evaluation 2 of vibration damping performance.

[0058] (Study 1-3: Study of polyalkylene glycol diglycidyl ether) The polyethylene glycol diglycidyl ether used in Examples 1 to 23 was changed to polytetramethylene glycol diglycidyl ether (manufactured by Yokkaichi Synthetic Co., Ltd., product name: Epogose-PT). Apart from this change, samples were prepared in the same manner as in Examples 1 to 23, and dynamic viscoelasticity was measured. Even in this case, results equivalent to those of Examples 1 to 23 were obtained for Evaluation 1 and Evaluation 2 of vibration damping performance.

[0059] (Study 2-1: Study of dimer acid diglycidyl ester) A sample was prepared in the same manner as in Examples 1 to 23, except that the dimer acid diglycidyl ester used in Examples 1 to 23 was replaced with a dimer acid diglycidyl ester from a different manufacturer (manufactured by Mitsubishi Chemical Corporation, product name: jER 871), and dynamic viscoelasticity was measured. Even in this case, results equivalent to those of Examples 1 to 23 were obtained for Evaluation 1 and Evaluation 2 of vibration damping performance.

[0060] (Study 2-2: Study of dimer acid diglycidyl ester) Samples were prepared and dynamic viscoelasticity was measured in the same manner as in Examples 1 to 23, except that the dimer acid diglycidyl ester used in Examples 1 to 23 was replaced with a dimer acid diglycidyl ester from a different manufacturer (manufactured by Kokudo Chemical Co., Ltd., product name: YD-171). Even in this case, results equivalent to those of Examples 1 to 23 were obtained for evaluations 1 and 2 of vibration damping performance.

[0061] (Study 3-1: Study of compounds with phenol groups) Samples were prepared and dynamic viscoelasticity was measured in the same manner as in Examples 1 to 23, except that the distyrenated phenol used in Examples 1 to 23 was replaced with cardanol oligomer (manufactured by Tohoku Kako Co., Ltd., product name: CD-5L). Even in this case, results equivalent to those of Examples 1 to 23 were obtained for Evaluation 1 and Evaluation 2 of vibration damping performance.

[0062] (Study 3-2: Study of compounds with phenol groups) Samples were prepared in the same manner as in Examples 1 to 23, except that the distyrenated phenol used in Examples 1 to 23 was replaced with methyl styrenated phenol (manufactured by Kolon, product name: HiRENOL PL1000-S), and dynamic viscoelasticity was measured. Even in this case, results equivalent to those of Examples 1 to 23 were obtained for Evaluation 1 and Evaluation 2 of vibration damping performance.

[0063] (Regarding the combination of the above ingredients) The raw materials used in the above Studies 1-1 to 1-3, the raw materials used in the above Studies 2-1 and 2-2, and the raw materials used in the above Studies 3-1 and 3-2 were arbitrarily combined to prepare samples in the same manner as in Examples 1 to 23, and dynamic viscoelasticity was measured. Even in this case, results equivalent to those of Examples 1 to 23 were obtained for Evaluations 1 and 2 of vibration damping performance.

Claims

1. An epoxy resin adhesive composition for use in a vehicle, comprising: bisphenol A epoxy resin, a polyalkylene glycol diglycidyl ether; Dimer acid diglycidyl ester, An epoxy resin adhesive composition comprising: a compound having a phenol group;

2. The content of the polyalkylene glycol diglycidyl ether is the content is in the range of 10 parts by mass or more and 60 parts by mass or less relative to 100 parts by mass of the bisphenol A type epoxy resin, The content of the dimer acid diglycidyl ester is the content is in the range of 10 parts by mass or more and 60 parts by mass or less relative to 100 parts by mass of the bisphenol A type epoxy resin, The total content of the polyalkylene glycol diglycidyl ether and the dimer acid diglycidyl ester is the content is in the range of 40 parts by mass or more and 90 parts by mass or less relative to 100 parts by mass of the bisphenol A type epoxy resin, The content of the compound having a phenol group is 2. The epoxy resin adhesive composition according to claim 1, wherein the content of the hydroxybenzoate is in the range of 50 parts by mass or more and 90 parts by mass or less per 100 parts by mass of the bisphenol A type epoxy resin.

3. The content of the polyalkylene glycol diglycidyl ether is the content is in the range of 20 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of the bisphenol A type epoxy resin, The content of the dimer acid diglycidyl ester is the content is in the range of 20 parts by mass or more and 50 parts by mass or less relative to 100 parts by mass of the bisphenol A type epoxy resin, The total content of the polyalkylene glycol diglycidyl ether and the dimer acid diglycidyl ester is the content is in the range of 50 parts by mass or more and 80 parts by mass or less relative to 100 parts by mass of the bisphenol A type epoxy resin, The content of the compound having a phenol group is 2. The epoxy resin adhesive composition according to claim 1, wherein the content of the hydroxybenzoate is in the range of 60 parts by mass or more and 80 parts by mass or less per 100 parts by mass of the bisphenol A type epoxy resin.

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