Moisture-curable resin composition

Abstract

The present invention provides a moisture-curable resin composition in which neither a polysiloxane nor a tin catalyst is used and which has high adhesiveness to metals and plastics and further has stable adhesion performance as an adhesive or sealant. The present disclosure relates to a moisture-curable resin composition comprising: component (A), which is a polyoxyalkylene polymer having a hydrolyzable silyl group and a (meth)acrylic polymer having a hydrolyzable silyl group; component (B), which is a silane coupling agent having one or more epoxy groups in the molecule; and component (C), which is a titanium catalyst.

Description

Moisture-curable resin composition

[0001] The present invention relates to a moisture-curable resin composition having excellent adhesion to metals and plastics and stable adhesive performance.

[0002] With the trend toward lighter automobiles, the use of resin materials is increasing in the automotive electrical components of next-generation electric vehicles (EVs) and hybrid vehicles (HVs). Formed-in-place gaskets (FIPGs) have traditionally been widely used as automotive adhesives and sealants. For example, as proposed in Japanese Patent Application Laid-Open No. 2006-143985, conventional FIPGs are primarily made of polysiloxane. However, FIPGs containing polysiloxanes are difficult to apply to automotive electrical components due to the risk of contact failure caused by low-molecular-weight siloxanes. Furthermore, conventional FIPGs use a tin catalyst as a curing catalyst, and their use is restricted by legal regulations. Furthermore, when used as adhesives or sealants, stable adhesive performance is required. Stable adhesive performance is determined by the state of failure when external force is applied after adhesion. Specifically, if the failure state is interfacial failure, in which failure occurs at the interface between the adherend and the adhesive or sealant, this is considered undesirable because variations in the interfacial state result in large variations in adhesive strength, while if the failure state is cohesive failure, in which failure occurs inside the adhesive or sealant, the adhesive performance is considered to be stable.

[0003] To solve the above problems, adhesives and sealants that do not use polysiloxanes or tin catalysts are needed, but they have the problem of poor adhesion to plastics. Furthermore, improving adhesion to engineering plastics results in a decrease in adhesion to metals due to differences in the rigidity of the materials. Furthermore, it has been difficult to obtain adhesives and sealants with stable adhesive performance.

[0004] As a result of extensive research to achieve the above object, the present inventors have discovered a moisture-curable resin composition that does not use polysiloxane or a tin catalyst, has high adhesion to metals and plastics, and also has stable adhesive performance as an adhesive or sealant.

[0005] The gist of the present invention will now be described.

[0006] [1] A moisture-curable resin composition comprising the following components (A) to (C): Component (A): a polyoxyalkylene polymer having a hydrolyzable silyl group and a (meth)acrylic polymer having a hydrolyzable silyl group; Component (B): a silane coupling agent having one or more epoxy groups in one molecule; and Component (C): a titanium catalyst.

[0007] [2] The moisture-curable resin composition according to [1], which does not contain a silane coupling agent having one or more amino groups in one molecule.

[0008] [3] The moisture-curable resin composition according to [1] or [2], further comprising a plasticizer as component (D).

[0009] [4] The moisture-curable resin composition according to [3], wherein the component (D) is a castor oil-modified fatty acid ester.

[0010] [5] The moisture-curable resin composition according to [3] or [4], wherein the blending amount of the (D) component is 1 to 100 parts by mass per 100 parts by mass of the (A) component.

[0011] [6] The moisture-curable resin composition according to any one of [1] to [5], further comprising an inorganic filler as component (E).

[0012] [7] The moisture-curable resin composition according to [6], wherein the component (E) contains heavy calcium carbonate powder and / or light calcium carbonate powder.

[0013] [8] The moisture-curable resin composition according to any one of [1] to [7], further comprising a silane compound having no reactive functional groups other than alkoxysilyl groups in one molecule.

[0014] [9] The moisture-curable resin composition according to any one of [1] to [8], which is used for bonding plastic members.

[0015]

[10] A cured product obtained by curing the moisture-curable resin composition according to any one of [1] to [9].

[0016] Modes for carrying out the present invention are described in detail below. The embodiments described herein are illustrative only to embody the technical concept of the present invention and are not intended to limit the present invention. Therefore, all other possible embodiments, methods of use, and operational techniques conceivable by those skilled in the art without departing from the spirit of the present invention are included within the scope and spirit of the present invention, as well as within the scope of the claims and their equivalents. The embodiments described herein can be arbitrarily combined to produce other embodiments. Note that, in this specification, the range "X to Y" means "X or more and Y or less," and "weight," "mass," "wt %," "mass %," and "parts by weight" and "parts by mass" are treated as synonyms. In this specification, "A and / or B" encompasses both A and B, as well as both A and B. Unless otherwise specified, in this specification, operations and measurements of physical properties are performed at room temperature (20°C to 25°C) and a relative humidity of 40% RH to 50% RH.

[0017] <Moisture-Curable Resin Composition> One embodiment of the present invention is a moisture-curable resin composition comprising: (A) component: a polyoxyalkylene polymer having a hydrolyzable silyl group and a (meth)acrylic polymer having a hydrolyzable silyl group; (B) component: a silane coupling agent having one or more epoxy groups per molecule; and (C) component: a titanium catalyst. The moisture-curable resin composition according to this embodiment has excellent adhesive strength to metals and plastics and stable adhesive performance. As a result, the moisture-curable resin composition according to this embodiment can be suitably used as an adhesive or sealant.

[0018] Hereinafter, each component contained in the moisture-curable resin composition according to this embodiment will be described in order.

[0019] [Component (A)] The component (A) used in the moisture-curable resin composition according to this embodiment is a polyoxyalkylene polymer having a hydrolyzable silyl group and a (meth)acrylic polymer having a hydrolyzable silyl group. That is, the component (A) is a mixture of (a1) a polyoxyalkylene polymer having a hydrolyzable silyl group and (a2) a (meth)acrylic polymer having a hydrolyzable silyl group. From the viewpoint of handling, the component (A) is preferably liquid at 25°C. In the component (A), the polyoxyalkylene polymer having a hydrolyzable silyl group may be used alone, or two or more types may be used in combination. In addition, in the component (A), the (meth)acrylic polymer having a hydrolyzable silyl group may be used alone, or two or more types may be used in combination.

[0020] A polyoxyalkylene polymer is a polymer whose main chain is composed of an oxyalkylene skeleton. Examples of oxyalkylene include polyethylene glycol, polypropylene glycol, polytrimethylene glycol, and polytetramethylene glycol. These polyoxyalkylene polymers may be homopolymers or copolymers.

[0021] The hydrolyzable silyl group is a group in which 1 to 3 hydrolyzable groups are bonded to a silicon atom. Examples of the hydrolyzable group include a halogen atom, an alkoxy group, an acyloxide group, a ketoximate group, an amino group, an amide group, an aminooxy group, and an alkenyloxide group. From the viewpoint of curability, an alkoxy group is preferred.

[0022] Examples of alkoxy groups include methoxy, ethoxy, propyloxy, isopropyloxy, butoxy, tert-butoxy, phenoxy, and benzyloxy groups. From the viewpoint of adhesive strength, methoxy and ethoxy groups are preferred, and methoxy is most preferred. These alkoxy groups may be used alone or in combination with different types. Preferred hydrolyzable silyl groups are trimethoxysilyl and triethoxysilyl groups.

[0023] A method for producing a polyoxyalkylene polymer having a hydrolyzable silyl group may be to introduce the hydrolyzable silyl group into a polyalkylene oxide (oxyalkylene skeleton) that is the main chain. For example, a polyoxyalkylene polymer having a hydrolyzable silyl group can be produced by a known method described in JP-A-63-012632 or JP-A-63-033425.

[0024] The (meth)acrylic polymer may have a main chain structure derived from (meth)acrylic acid. Here, (meth)acrylic is a general term including acrylic and methacrylic, and (meth)acrylate is a general term including acrylate and methacrylate.

[0025] The (meth)acrylic monomer for synthesizing the (meth)acrylic polymer is not particularly limited, and various types can be used. The (meth)acrylic monomer is a general term for a monomer having an acrylic group or a methacrylic group. Examples of the (meth)acrylic monomer include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, (meth)acrylic acid esters, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, cyclohexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, phenyl (meth)acrylate, toluyl (meth)acrylate, benzyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 3-methoxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate,

[0049] Examples of suitable perfluoromethyl acrylates include, but are not limited to, hydroxypropyl, stearyl (meth)acrylate, glycidyl (meth)acrylate, 2-aminoethyl (meth)acrylate, γ-(methacryloyloxypropyl)trimethoxysilane, ethylene oxide adducts of (meth)acrylic acid, trifluoromethylmethyl (meth)acrylate, 2-trifluoromethylethyl (meth)acrylate, 2-perfluoroethylethyl (meth)acrylate, 2-perfluoroethyl-2-perfluorobutylethyl (meth)acrylate, 2-perfluoroethyl (meth)acrylate, perfluoromethyl (meth)acrylate, diperfluoromethylmethyl (meth)acrylate, 2-perfluoromethyl-2-perfluoroethylmethyl (meth)acrylate, 2-perfluorohexylethyl (meth)acrylate, 2-perfluorodecylethyl (meth)acrylate, and 2-perfluorohexadecylethyl (meth)acrylate.

[0026] As a monomer for producing a (meth)acrylic polymer, any (meth)acrylic monomer can be appropriately selected, but it is preferable to select a (meth)acrylic monomer having a hydrocarbon group. A (meth)acrylic polymer can be obtained by various polymerization methods, and the method is not particularly limited. However, radical polymerization is preferred from the viewpoint of the versatility of the monomer and ease of reaction control. Among radical polymerizations, controlled radical polymerization is preferred, living radical polymerization is more preferred, and atom transfer radical polymerization is particularly preferred. A method for producing a (meth)acrylic polymer having a hydrolyzable silyl group can be achieved by introducing a hydrolyzable silyl group into the (meth)acrylic polymer main chain. For example, a (meth)acrylic polymer having a hydrolyzable silyl group can be produced by a known method described in JP-A-2000-154205.

[0027] In the moisture-curable resin composition according to this embodiment, the hydrolyzable silyl group in component (A) may be present in either the side chain and / or the terminal of component (A), but from the viewpoint of moisture curing, it is preferable that it be present at the terminal or both terminals of the main chain. More specifically, in the polyoxyalkylene polymer, the hydrolyzable silyl group may be present in either the side chain and / or the terminal of the polyoxyalkylene polymer, but from the viewpoint of moisture curing, it is preferable that it be present at the terminal or both terminals of the main chain. In the (meth)acrylic polymer, the hydrolyzable silyl group may be present in either the side chain and / or the terminal of the (meth)acrylic polymer, but from the viewpoint of moisture curing, it is preferable that it be present in the side chain.

[0028] In component (A), the number of hydrolyzable silyl groups present is preferably 2 or more, more preferably 3 or more, and even more preferably 4 or more. More specifically, the polyoxyalkylene polymer preferably has 2 hydrolyzable silyl groups, and the (meth)acrylic polymer preferably has 2 or more hydrolyzable silyl groups.

[0029] The viscosity of component (A) at 23°C is preferably 1 to 500 Pa·s, more preferably 10 to 300 Pa·s, even more preferably 20 to 200 Pa·s, particularly preferably 30 to 180 Pa·s, and most preferably 50 to 150 Pa·s. If the viscosity is 1 Pa·s or higher, the moisture-curable resin composition has good workability, and if the viscosity is 500 Pa·s or lower, there is no risk of reducing workability even when mixed with components (B) and (C). The viscosity of component (A) is a value measured using a BS-type viscometer.

[0030] In component (A), the mass ratio of the polyoxyalkylene polymer having a hydrolyzable silyl group to the (meth)acrylic polymer having a hydrolyzable silyl group is, for example, preferably 40:60 to 95:5, more preferably 45:65 to 90:10, and even more preferably 50:50 to 90:10. When the mass ratio of the polyoxyalkylene polymer to the (meth)acrylic polymer is within the above range, superior adhesive strength to metals and plastics can be exhibited.

[0031] The component (A) is preferably a mixture of polyethylene oxide having a hydrolyzable silyl group and a (meth)acrylic polymer having a hydrolyzable silyl group; or a mixture of polypropylene oxide having a hydrolyzable silyl group and a (meth)acrylic polymer having a hydrolyzable silyl group.

[0032] Commercially available products of component (A) include, but are not limited to, MA440, MA447, MA451, MA903, MA903M, MA904, etc. (manufactured by Kaneka Corporation). These may be used alone or in combination of two or more.

[0033] In the moisture-curable resin composition according to this embodiment, the blending amount of component (A) is, for example, preferably 10 to 95% by mass, more preferably 15 to 90% by mass, even more preferably 18 to 85% by mass, particularly preferably 20 to 80% by mass, and most preferably 25 to 75% by mass, relative to 100% by mass of the composition. According to one embodiment, in the moisture-curable resin composition according to this embodiment, the blending amount of component (A) is 20 to 70% by mass, 20 to 65% by mass, 20 to 60% by mass, 20 to 50% by mass, or 25 to 50% by mass, relative to 100% by mass of the composition. If the blending amount of component (A) is within the above range, it can exhibit better adhesive strength to metals and plastics.

[0034] [Component (B)] The component (B) used in the moisture-curable resin composition according to this embodiment is a silane coupling agent having one or more epoxy groups per molecule. Component (B) can improve adhesive strength to metals and plastics and improve the cohesive failure rate. Specific examples of component (B) include, but are not limited to, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropyltriethoxysilane. These may be used alone or in combination of two or more. From the viewpoint of improving adhesive strength to metals and plastics and improving the cohesive failure rate, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, and 3-glycidoxypropyltriethoxysilane are preferred.

[0035] The moisture-curable resin composition according to this embodiment preferably does not substantially contain a silane coupling agent (aminosilane coupling agent) having one or more amino groups per molecule. If the moisture-curable resin composition according to this embodiment contains a silane coupling agent having an amino group, the adhesion to metals and plastics decreases. Furthermore, the reaction with component (B) causes a decrease in the adhesive strength and cohesive failure rate to metals and plastics. "Substantially free" here means that the blending amount is less than 0.1% by mass relative to 100% by mass of the entire moisture-curable resin composition. Examples of silane coupling agents having one or more amino groups per molecule include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 3-triethoxysilyl-N-(1,3-dimethyl-butylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, and N-(vinylbenzyl)-2-aminoethyl-3-aminopropyltrimethoxysilane hydrochloride. According to one embodiment, in the moisture-curable resin composition according to this embodiment, component (B) is a silane coupling agent having one or more epoxy groups per molecule and no amino group.

[0036] The blend amount of component (B) is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 18 parts by mass, even more preferably 0.5 to 16 parts by mass, particularly preferably 1 to 15 parts by mass, and most preferably 3 to 10 parts by mass, per 100 parts by mass of component (A). When the blend amount of component (B) is within the above range, it is possible to achieve improved adhesive strength to metals and plastics and an improved cohesive failure rate, without any risk of reducing storage stability.

[0037] [Component (C)] The component (C) that can be used in the moisture-curable resin composition according to this embodiment is a titanium catalyst. In the moisture-curable resin composition according to this embodiment, the component (C) is a curing catalyst for the component (A), and by combining the component (C) with the components (A) and (B), it is possible to improve the adhesive strength and cohesive failure rate to metals and plastics. Specific examples of component (C) include, but are not limited to, tetraisopropyl titanate, tetra-normal butyl titanate, butyl titanate dimer, tetraoctyl titanate, titanium acetylacetonate, titanium tetraacetylacetonate, titanium ethylacetoacetate, dodecylbenzenesulfonic acid titanium compound, phosphate ester titanium complex, titanium octylene glycolate, titanium lactate ammonium salt, titanium lactate, titanium triethanolamine, tetraisopropyl titanate, tetratertiary butyl titanate, tetrastearyl titanate, titanium acetylacetonate, titanium octylene glycolate compound, titanium isostearate, titanium lactate, titanium lactate ammonium salt, titanium diethanolamine, titanium aminoethylamino etherate, etc. These may be used alone or in combination of two or more. From the viewpoint of improving the adhesive strength and cohesive failure rate to metals and plastics, chelate-based titanium catalysts such as titanium tetraacetylacetonate, titanium dodecylbenzenesulfonate compounds, phosphate ester titanium complexes, titanium octylene glycolate, titanium ethyl acetoacetate, titanium acetylacetonate, and titanium octylene glycolate compounds are preferred, with titanium acetylacetonate, titanium tetraacetylacetonate, and titanium ethyl acetoacetate being more preferred, and titanium diisopropoxybis(ethyl acetoacetate) being most preferred.

[0038] The amount of component (C) blended is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 18 parts by mass, even more preferably 0.5 to 16 parts by mass, particularly preferably 1 to 15 parts by mass, and most preferably 3 to 10 parts by mass, per 100 parts by mass of component (A). When the amount of component (C) blended is within the above range, a cured product having excellent adhesive strength to metals and plastics and excellent cohesive failure rate can be obtained, and there is no risk of reduced storage stability.

[0039] [Component (D)] The moisture-curable resin composition according to this embodiment preferably further contains a plasticizer as component (D). Component (D) can be broadly classified into phthalate ester plasticizers and non-phthalate plasticizers, with non-phthalate ester plasticizers being preferred due to their low carcinogenicity and the ability to maintain the effects of the present invention. Non-phthalate plasticizers are not particularly limited, but examples include (meth)acrylic polymer plasticizers obtained by polymerizing (meth)acrylic monomers; polyether polyol plasticizers such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; polyester plasticizers obtained from dibasic acids such as sebacic acid and adipic acid and dihydric alcohols such as ethylene glycol, diethylene glycol, triethylene glycol, and propylene glycol; process oil plasticizers; alkylsulfonic acid phenyl esters, acetyl tributyl citrate; and castor oil-modified fatty acid esters. These may be used alone or in combination of two or more. From the viewpoint of not reducing the adhesive strength to metals or plastics and the cohesive failure rate, castor oil-modified fatty acid esters and / or alkylsulfonic acid phenyl esters are preferred, and castor oil-modified fatty acid esters are most preferred.

[0040] The amount of component (D) blended is preferably 1 to 100 parts by mass, more preferably 5 to 80 parts by mass, even more preferably 8 to 75 parts by mass, particularly preferably 10 to 70 parts by mass, and most preferably 20 to 60 parts by mass, per 100 parts by mass of component (A). By blending the amount of component (D) within the above range, the cured product can be made flexible, and there is no risk of a decrease in adhesive strength or cohesive failure rate.

[0041] [Component (E)] The moisture-curable resin composition according to this embodiment may further contain an inorganic filler as component (E). By including component (E) in the moisture-curable resin composition according to this embodiment, resin strength can be improved. Examples of component (E) include, but are not limited to, talc powder, silica powder, clay powder, calcium carbonate powder, magnesium carbonate powder, calcium silicate powder, glass powder, alumina powder, zinc oxide powder, magnesium oxide powder, aluminum nitride powder, boron nitride powder, carbon powder, diamond powder, gold powder, silver powder, copper powder, and nickel powder. From the viewpoint of improving resin strength without reducing adhesive strength or cohesive failure rate, it is preferable to include calcium carbonate powder, and it is preferable to include both heavy calcium carbonate powder (E-1) and light calcium carbonate powder (E-2). It is most preferable to include both untreated heavy calcium carbonate powder (E-1) and light calcium carbonate powder (E-2) that has been surface-treated with a fatty acid.

[0042] From the viewpoint of improving resin strength without reducing adhesive strength or cohesive failure rate, component (E) preferably has an average particle size of 0.01 to 10 μm, more preferably 0.02 to 8 μm, even more preferably 0.03 to 7 μm, particularly preferably 0.03 to 6 μm, and most preferably 0.03 to 5 μm. Here, when component (E) is heavy calcium carbonate powder (E-1), the average particle size of component (E-1) is preferably 0.01 to 10 μm, more preferably 0.02 to 8 μm, even more preferably 0.05 to 7 μm, particularly preferably 0.1 to 6 μm, and most preferably 0.5 to 5 μm. When component (E) is precipitated calcium carbonate powder (E-2), the average particle size of component (E-2) is preferably 0.01 to 10 μm, more preferably 0.01 to 5 μm, even more preferably 0.02 to 3 μm, particularly preferably 0.02 to 2 μm, and most preferably 0.03 to 1 μm. Having the average particle sizes of components (E-1) and (E-2) within the above ranges can further improve adhesive strength and cohesive failure rate. The average particle size in the present invention is the particle size (D50) value at a cumulative volume ratio of 50% in the particle size distribution determined by laser diffraction scattering.

[0043] The BET specific surface area of ​​component (E) is set to 1,000 cm from the viewpoint of compatibility with component (A). ２ / g~50,000cm ２ / g is preferred, and 1,500 cm ２ / g~40,000cm ２ / g is more preferred, and 2,000 cm ２ / g~30,000cm ２ / g is more preferable, and 2,500 cm ２ / g~25,000cm ２ / g is particularly preferred, and 3,000 cm ２ / g~20,000cm ２ When component (E) is heavy calcium carbonate powder (E-1), the BET specific surface area of ​​component (E-1) is preferably 3,000 cm ２ / g~50,000cm ２ / g is preferred, and 3,500 cm２ / g~40,000cm ２ / g is more preferred, and 5,000 cm ２ / g~30,000cm ２ / g is more preferable, and 7,500 cm ２ / g~25,000cm ２ / g is particularly preferred, and 8,000 cm ２ / g~20,000cm ２ When component (E) is precipitated calcium carbonate powder (E-2), the BET specific surface area of ​​component (E-2) is most preferably 1,000 cm ２ / g~30,000cm ２ / g is preferred, and 1,200 cm ２ / g~20,000cm ２ / g is more preferred, and 1,500 cm ２ / g~15,000cm ２ / g is more preferable, and 2,000 cm ２ / g~10,000cm ２ / g is particularly preferred, and 3,000 cm ２ / g~8,000cm ２ When the BET specific surface areas of the components (E-1) and (E-2) are within the above ranges, the adhesive strength and the cohesive failure rate can be further improved.

[0044] The amount of component (E) is preferably 10 to 300 parts by mass, more preferably 20 to 280 parts by mass, even more preferably 50 to 250 parts by mass, particularly preferably 80 to 220 parts by mass, and most preferably 100 to 200 parts by mass, per 100 parts by mass of component (A). By incorporating the amount of component (E) within the above range, resin strength can be improved without reducing adhesive strength or cohesive failure rate. When both components (E-1) and (E-2) are included, the mass ratio of the amounts ((E-1):(E-2)) is preferably 10:90 to 70:30, more preferably 10:90 to 50:50, even more preferably 15:85 to 50:50, particularly preferably 20:80 to 50:50, and most preferably 25:75 to 50:50. When the mass ratio of the component (E-1) and the component (E-2) is within the above range, the adhesive strength and the cohesive failure rate can be further improved.

[0045] [Additives] The moisture-curable resin composition according to this embodiment may further contain an appropriate amount of additives (components (F) to (I)) such as a storage stabilizer, an antioxidant, a colorant, and an organic filler, within a range that does not impair the properties.

[0046] [Component (F)] The moisture-curable resin composition according to this embodiment may contain a storage stabilizer as component (F). Examples of component (F) (storage stabilizer) include a silane compound that does not have a reactive functional group other than an alkoxysilyl group. By including a silane compound that does not have a reactive functional group other than an alkoxysilyl group in the moisture-curable resin composition according to this embodiment, the effect of suppressing excessive reaction of component (A) is exhibited. In this specification, examples of reactive functional groups other than alkoxysilyl groups include, but are not limited to, vinyl groups, epoxy groups, (meth)acrylic groups, amino groups, isocyanurate groups, ureido groups, mercapto groups, isocyanate groups, acid anhydride groups, and carboxy groups. Specific examples of silane compounds that do not have reactive functional groups other than alkoxysilyl groups include alkylsilane compounds such as methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, n-propyltrimethoxysilane, hexyltrimethoxysilane, decyltrimethoxysilane, 1,6-bis(trimethoxysilyl)hexane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, n-propyltriethoxysilane, hexyltriethoxysilane, octyltriethoxysilane, and decyltriethoxysilane. These may be used alone or in combination of two or more. From the viewpoint of improving the storage stability of the moisture-curable resin composition according to this embodiment, it is preferable to contain methyltrimethoxysilane and / or diphenyldimethoxysilane, and it is more preferable to contain methyltrimethoxysilane and diphenyldimethoxysilane. The amount of component (F) (storage stabilizer) blended is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass, and most preferably 1.0 to 10 parts by mass, per 100 parts by mass of component (A). By blending the amount of component (F) within this range, storage stability is improved and there is no risk of a decrease in curability.When both methyltrimethoxysilane and diphenyldimethoxysilane are contained as component (F), the mass ratio of methyltrimethoxysilane to diphenyldimethoxysilane (methyltrimethoxysilane:diphenyldimethoxysilane) is preferably 99:1 to 50:50, more preferably 95:5 to 50:50, even more preferably 90:10 to 50:50, particularly preferably 85:15 to 55:45, and most preferably 85:15 to 60:40. When the mass ratio of methyltrimethoxysilane to diphenyldimethoxysilane is within the above range, storage stability is improved and there is no risk of a decrease in adhesive strength or cohesive failure rate.

[0047] [Component (G)] The moisture-curable resin composition according to this embodiment may contain an antioxidant as component (G). By containing an antioxidant as component (G), a cured product with excellent heat resistance can be obtained. Examples of antioxidants include quinone compounds such as β-naphthoquinone, 2-methoxy-1,4-naphthoquinone, methylhydroquinone, hydroquinone, hydroquinone monomethyl ether, mono-tert-butylhydroquinone, 2,5-di-tert-butylhydroquinone, p-benzoquinone, 2,5-diphenyl-p-benzoquinone, and 2,5-di-tert-butyl-p-benzoquinone; phenothiazine, 2,2-methylene-bis(4-methyl-6-tert-butylphenol); ), catechol, tert-butylcatechol, 2-butyl-4-hydroxyanisole, 2,6-di-tert-butyl-p-cresol, 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, 4,4'-butylidenebis(6-tert-butyl-3-methylphenyl) 4,4'-thiobis(6-tert-butyl-3-methylphenol), 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5,5]undecane, pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], thiodiethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionamide], benzenepropanoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy, C7-C9 side chain alkyl ester, 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate, 3,3',3'',5,5',5''-hexa-tert-butyl-a,a',a''-(mesitylene-2,4,6-tolyl)tri-p-cresol, calcium diethyl bis[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate, 4,6-bis(octylthiomethyl)-o-cresol, ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate nate], hexamethylenebis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 1,3,5-tris[(4-tert-butyl-3-hydroxy-2,6-xylyl)methyl]-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, reaction products of N-phenylbenzenamine with 2,4,6-trimethylpentene, 2 phenols such as 4,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, picric acid, and citric acid; tris(2,4-di-tert-butylphenyl)phosphite, tris[2-[[2,4,8,10-tetra-tert-butyldibenzo[d,f][1,3,2]dioxaphosphen-6-yl]oxy]ethyl]amine, bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, bis[2,4-bis(1,1 phosphorus compounds such as tetrakis(2,4-di-tert-butylphenyl)[1,1-bisphenyl]-4,4'-diylbisphosphonite, 6-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10-tetra-tert-butyldibenz[d,f][1,3,2]dioxaphosphene; dilauryl 3,3'-thiodipropionate, dimyristyl 3,3'-thiodipropionate, distearyl 3,Examples of antioxidants include sulfur-based compounds such as 3'-thiodipropionate, pentaerythrityl tetrakis(3-laurylthiopropionate), and 2-mercaptobenzimidazole; thioether-based compounds; amine-based compounds such as phenothiazine; lactone-based compounds; and vitamin E-based compounds. These may be used alone or in combination. From the viewpoint of improving storage stability and heat resistance, it is preferable to contain an amine-based antioxidant and / or a thioether-based compound, and it is more preferable to contain a thioether-based compound. The amount of component (G) (antioxidant) is preferably 0.01 to 5 parts by mass, more preferably 0.02 to 4 parts by mass, even more preferably 0.05 to 3 parts by mass, particularly preferably 0.1 to 3 parts by mass, and most preferably 0.5 to 3 parts by mass, per 100 parts by mass of component (A). A content of 0.01 to 5 parts by mass prevents a decrease in adhesive strength or cohesive failure rate.

[0048] [Component (H)] In the moisture-curable resin composition according to this embodiment, a colorant can be added as component (H). Examples of component (H) include inorganic pigments such as carbon black, barium sulfate, alumina white, clay, and titanium oxide; organic pigments such as indanthrone blue, quinacridone red, dioxazine violet, and phthalocyanine blue; ZnS:Ag, ZnS:Cu, ZnS:Mn, and SrAl. ２ O ４ : Eu, Sr ４ Al １４ O ２５ : Eu, Y ２ O ２ S: Eu, Y ２ O ３Examples of the pigment include fluorescent inorganic pigments such as Eu, fluorescent organic pigments, and dyes. These pigments may be used alone or in combination of two or more. From the viewpoint of not reducing the adhesive strength and cohesive failure rate, inorganic pigments are preferred, and carbon black is most preferred. The amount of component (H) (colorant) is preferably 0.01 to 5 parts by mass, more preferably 0.05 to 4 parts by mass, even more preferably 0.1 to 3% by mass, particularly preferably 0.2 to 3 parts by mass, and most preferably 0.3 to 2% by mass, relative to 100% by mass of the entire moisture-curable resin composition. When the amount of component (H) is within the above range, there is no risk of reducing the adhesive strength and cohesive failure rate.

[0049] [Component (I)] The moisture-curable resin composition according to this embodiment may contain an organic filler as component (I). The organic filler may be an organic powder composed of rubber, elastomer, plastic, polymer (or copolymer), or the like. These may be used alone or in combination of two or more. Organic fillers having a multilayer structure, such as a core-shell structure, may also be used. The average particle size of the organic filler is preferably in the range of 0.05 to 50 μm. The amount of component (I) (colorant) is preferably 0.01 to 5 parts by mass, more preferably 0.02 to 4 parts by mass, even more preferably 0.05 to 3 parts by mass, particularly preferably 0.1 to 3 parts by mass, and most preferably 0.5 to 3 parts by mass, per 100 parts by mass of component (A). When the amount of component (I) is within the above range, there is no risk of a decrease in adhesive strength and cohesive failure rate.

[0050] <Applications> The moisture-curable resin composition according to this embodiment can be a one-component type or a two-component type as needed. Furthermore, the moisture-curable resin composition according to this embodiment is most suitable for use as an adhesive or sealant, but can also be used as a pressure-sensitive adhesive, coating agent, potting agent, etc. as needed. The moisture-curable resin composition according to this embodiment can be used for various electrical and electronic fields, buildings, automobiles, civil engineering, etc., but since it does not contain cyclic low-molecular-weight siloxanes such as octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, and dodecamethylcyclohexasiloxane, it is particularly suitable for use in electrical and electronic components and automotive electrical components.

[0051] <Adherend> The moisture-curable resin composition according to this embodiment has excellent adhesive strength and stable adhesive performance to metals and plastics, making it suitable for bonding a variety of materials and also applicable to bonding materials of different materials. Metals are not particularly limited, but examples include iron, aluminum, magnesium, copper, stainless steel, and titanium. Plastics are not particularly limited, but examples include fiber-reinforced plastic (FRP), carbon fiber-reinforced plastic (CFRP), polyacrylic, polyester, polyamide, acrylonitrile-butadiene-styrene, 6,6-nylon, polycarbonate, polyacetal, polyethylene terephthalate, polybutylene terephthalate, polyphenylene sulfide, polyphenylene ether, polyether ether ketone, polyethylene, and polypropylene. Rubbers are not particularly limited, but examples include nitrile rubber, urethane rubber, silicone rubber, and ethylene propylene diene rubber (EPDM). Examples include adhesion between at least two types of adherends selected from these materials. The surfaces of these materials may be pre-treated or left untreated. In one embodiment, the moisture-curable resin composition according to this embodiment adheres a metal (e.g., aluminum) to a plastic (e.g., 6,6-nylon or polybutylene terephthalate) with a shear bond strength of 0.7 MPa or more (preferably 0.8 MPa or more), calculated according to the method in the examples described below.

[0052] <Application Method> The moisture-curable resin composition according to this embodiment can be applied to an adherend by a known application method for a sealant or adhesive. For example, methods such as dispensing using an automatic coater, spraying, inkjet printing, screen printing, gravure printing, dipping, and spin coating can be used. Note that the moisture-curable resin composition according to this embodiment is liquid at 25°C from the viewpoint of coatability. The viscosity is preferably 1000 Pa s or less at 25°C.

[0053] <Curing Method> The moisture-curable resin composition according to this embodiment is not particularly limited as to the curing temperature, but is preferably 10 to 50°C, and more preferably 15 to 30°C. The relative humidity is preferably 40% RH or higher, and the curing time is preferably 1 hour or more but less than 2 weeks (336 hours), more preferably 1 hour or more but less than 288 hours, even more preferably 2 hours or more but less than 240 hours, particularly preferably 3 hours or more but less than 216 hours, and most preferably 5 hours or more but less than 192 hours. According to one embodiment, the moisture-curable resin composition according to this embodiment is cured (aged) at 10 to 50°C (preferably 15 to 30°C) for 1 hour or more but less than 336 hours (preferably 2 hours or more but less than 288 hours, more preferably 2 hours or more but less than 240 hours, and even more preferably 3 hours or more but less than 216 hours).

[0054] <Sealing Method> The sealing method using the moisture-curable resin composition according to the present embodiment is not particularly limited, but representative examples include FIPG (formed-in-place gasket), CIPG (cured-in-place gasket), MIPG (molded-in-place gasket), and liquid injection molding.

[0055] The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples.

[0056] Examples 1 to 3, Comparative Examples 1 to 6 The following components were prepared to prepare moisture-curable resin compositions.

[0057] <Component (A): Polyoxyalkylene polymer having hydrolyzable silyl groups and (meth)acrylic polymer having hydrolyzable silyl groups> Component (A-1): A mixture of (a1) a polyoxyalkylene polymer (polypropylene oxide) having hydrolyzable silyl groups (trimethoxysilyl groups) at both ends and (a2) a (meth)acrylic polymer having two or more hydrolyzable silyl groups (dimethoxysilyl groups and / or trimethoxysilyl groups) on side chains. Product name: MA451 (Kaneka Corporation). Viscosity (23°C): 90 Pa·s (50% by mass or more of (a1) and less than 50% by mass of (a2) in component (A-1)). Component (A'-1): A polyoxyalkylene polymer having trimethoxysilyl groups on both ends. Product name: SAX575 (Kaneka Corporation). Viscosity (23°C): 50 Pa·s. Component (A'-2): A (meth)acrylic polymer having two dimethoxysilyl groups on side chains. Product name: SA100S (Kaneka Corporation) Viscosity (23°C): 210 Pa·s <Component (B): Silane coupling agent having one or more epoxy groups per molecule> Component (B-1): 3-glycidoxypropyltrimethoxysilane Product name: KBM-403 (Shin-Etsu Chemical Co., Ltd.) Component (B-2): 2-(3,4-Epoxycyclohexyl)ethyltrimethoxysilane, trade name: KBM-303 (Shin-Etsu Chemical Co., Ltd.) Component (B-3): 3-glycidoxypropyltriethoxysilane, trade name: KBE-403 (Shin-Etsu Chemical Co., Ltd.) Component (B'-1): N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, trade name: KBM-603 (Shin-Etsu Chemical Co., Ltd.) Component (B'-2): 3-methacryloxypropyltrimethoxysilane, trade name: KBM-503 (Shin-Etsu Chemical Co., Ltd.) <Component (C): Titanium catalyst> Component (C-1): Chelate-type titanium catalyst Titanium diisopropoxybis(ethylacetoacetate), trade name: TC-750 (Matsumoto Fine Chemical Co., Ltd.) Component (C'-1): Zinc catalyst containing alkylamine, trade name: K-KAT670 (King Industries) Component (C'-2): dioctylbis[(1-oxododecyl)oxy]tin, trade name: Neostan U-810 (Nitto Kasei Co., Ltd.) <Component (D): plasticizer> Component (D-1): castor oil-modified fatty acid ester, trade name: Rickcizer GR-301 (Ito Oil Mills Co., Ltd.) <Component (E): inorganic filler> Component (E-1): unsurface-treated heavy calcium carbonate, trade name: Softon 1800 (Bihoku Funka Kogyo Co., Ltd.) Average particle size: 1.25 μm Specific surface area: 18,000 cm ２ / g (E-2) Component: Precipitated calcium carbonate surface-treated with fatty acid soap. Product name: Calfine 500 (Maruo Calcium Co., Ltd.). Average particle size: 0.05 μm. Specific surface area: 5,000 cm. ２ / g <Component (F): Storage stabilizer> Component (F-1): Methyltrimethoxysilane, trade name: KBM-13 (Shin-Etsu Chemical Co., Ltd.) Component (F-2): Diphenyldimethoxysilane, trade name: KBM-202SS (Shin-Etsu Chemical Co., Ltd.) <Component (G): Antioxidant> Component (G-1): Thioether-based antioxidant, trade name: ADK STAB AO-26 <Component (H): Colorant> Component (H-1): Carbon black.

[0058] Components (A), (B), and (D) to (H) were weighed into a stirring vessel and stirred for 30 minutes. Component (C) was then added and stirred for 1 hour. Detailed amounts prepared are shown in Table 1, and all values ​​are expressed in parts by mass. A blank space in the table indicates that the component was not added.

[0059] The shear adhesive strength (AL / PA66) and shear adhesive strength (AL / PBT) of each moisture-curable resin composition were evaluated according to the following methods. In addition, the cohesive failure rate was calculated for each shear adhesive strength measurement.

[0060] [Shear Adhesion Strength (AL / PA66)] A moisture-curable resin composition was applied to an aluminum (A1050P) test piece measuring 25 mm wide x 100 mm long x 1 mm thick. A 6,6-nylon test piece measuring 25 mm wide x 100 mm long x 1 mm thick was then bonded and fixed to the aluminum (A1050P) test piece so that the overlapping surface was 25 mm x 10 mm x 1 mm clearance. The test piece was then aged for 7 days at 23°C and 50% RH to obtain a test specimen. The shear adhesive strength (unit: MPa) was measured at 25°C using a universal tensile tester (tensile speed: 50 mm / min) in accordance with JIS K 6850:1999. The shear adhesive strength was the value at maximum strength. The pass criterion for shear adhesive strength (AL / PA66) was 0.7 MPa or more.

[0061] [Shear Adhesion Strength (AL / PBT)] A moisture-curable resin composition was applied to an aluminum (A1050P) test piece measuring 25 mm wide x 100 mm long x 1 mm thick. Then, a polybutylene terephthalate test piece measuring 25 mm wide x 100 mm long x 1 mm thick was attached to the aluminum (A1050P) test piece so that the overlapping surface was 25 mm x 10 mm x 1 mm clearance. The test piece was then aged for 7 days at 23 ° C. and 50% RH to obtain a test specimen. The shear adhesive strength (unit: MPa) was measured at 25 ° C. using a universal tensile tester (tensile speed: 50 mm / min) according to JIS K 6850:1999. The shear adhesive strength was the value at maximum strength. The pass criterion for shear adhesive strength (AL / PBT) was 0.7 MPa or more.

[0062] [Cohesive Failure Rate] The state of failure of the test piece after the shear adhesive strength test was visually confirmed, and the area percentage of the cohesive failure state was calculated. Here, when observing the fracture surface, the failure state was judged as cohesive failure when the part where the cured material remained on both sides of the test piece, and interfacial failure when the part where the cured material did not remain on one side. The total area of ​​the observed fracture surfaces was set to 100, and the area percentage of cohesive failure on the fracture surface (total area) was calculated. The pass criterion for the cohesive failure rate was set to 100% (the entire fracture surface was cohesive failure and there was no interfacial failure state).

[0063]

[0064] Examples 1 to 3 are moisture-curable resin compositions containing components (A) to (C). The shear adhesive strength of test pieces made of aluminum and 6,6-nylon or aluminum and polybutylene terephthalate was excellent, and the cohesive failure rate, an indicator of adhesive performance stability, also showed satisfactory results. On the other hand, partial interfacial failure was observed in Comparative Examples 1 and 2, which used component (B)'. Comparative Example 3, which used a tin catalyst as the curing catalyst, also showed low shear adhesive strength and all interfacial failure. Comparative Example 4, which used a zinc catalyst, also showed partial interfacial failure. Comparative Example 5, which used only a polyoxyalkylene polymer having a hydrolyzable silyl group instead of component (A), also showed low shear adhesive strength and 100% interfacial failure. Comparative Example 6, which used only a (meth)acrylic polymer having a hydrolyzable silyl group instead of component (A), also showed low shear adhesive strength and partial interfacial failure. From the above, it can be seen that the inclusion of components (A) to (C) provides high adhesive strength and stable adhesive performance.

[0065] The present invention has excellent adhesive strength to metals and plastics and also has stable adhesive performance, and therefore can be applied to fields where various materials are used as adhesives and sealants, and is extremely useful.

[0066] This application is based on Japanese Patent Application No. 2024-41819, filed on March 18, 2024, the disclosure of which is hereby incorporated by reference in its entirety.

Claims

1. A moisture-curable resin composition comprising the following components (A) to (C): Component (A): a polyoxyalkylene polymer having a hydrolyzable silyl group and a (meth)acrylic polymer having a hydrolyzable silyl group; Component (B): a silane coupling agent having one or more epoxy groups per molecule; and Component (C): a titanium catalyst.

2. The moisture-curable resin composition according to claim 1, which does not contain a silane coupling agent having one or more amino groups in one molecule.

3. The moisture-curable resin composition according to claim 1 or 2, further comprising a plasticizer as component (D).

4. The moisture-curable resin composition according to claim 3, wherein component (D) is a castor oil-modified fatty acid ester.

5. The moisture-curable resin composition according to claim 1 or 2, further comprising an inorganic filler as component (E).

6. The moisture-curable resin composition according to claim 5, wherein the component (E) comprises heavy calcium carbonate powder and / or light calcium carbonate powder.

7. The moisture-curable resin composition according to claim 3, wherein the blending amount of the component (D) is 1 to 100 parts by mass per 100 parts by mass of the component (A).

8. The moisture-curable resin composition according to claim 1 or 2, further comprising a silane compound having no reactive functional groups other than alkoxysilyl groups in one molecule.

9. The moisture-curable resin composition according to claim 1 or 2, which is used for bonding plastic members.

10. A cured product obtained by curing the moisture-curable resin composition according to claim 1 or 2.

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