Urethane-based sealant composition

Abstract

To provide a urethane sealant composition having excellent adhesion and heat resistance.SOLUTION: A urethane sealant composition contains, based on a urethane prepolymer 100 pts.mass, an epoxy compound containing an epoxy group and a hydrolyzable silyl group of 2-10 pts.mass and a latent curing agent of 1-10 pts.mass.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This invention relates to a urethane-based sealing material composition. [Background technology]

[0002] Conventionally, sealant compositions have been used to seal joints in buildings and other structures. Examples of sealant compositions include compositions containing urethane prepolymers.

[0003] To date, for example, Patent Document 1 has proposed a composition containing a urethane prepolymer or the like. Patent Document 1 aims to provide a latent curing agent with excellent storage stability and curing properties, comprising a urethane prepolymer with general formula (1): [ka] (In the formula, R 1 R is an aliphatic hydrocarbon group with 5 or more carbon atoms. 2 We proposed a urethane resin composition comprising an oxazolidine compound represented by (where m is an integer from 1 to 6 and n is an integer from 0 to 4), where m is a residue obtained by removing the isocyanate group from an organic polyisocyanate. [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 07-33852 [Overview of the project] [Problems that the invention aims to solve]

[0005] In this context, the present inventors prepared a composition containing a urethane prepolymer and a latent curing agent with reference to Patent Document 1 and evaluated it. It became clear that such a composition may have low adhesion and heat resistance (Comparative Example 1).

[0006] On the other hand, urethane prepolymers sometimes contain silane coupling agents, but in the above cases, the silane coupling agent is usually used for its function as an adhesion promoter. The actual amount of silane coupling agent used as an adhesion promoter is usually about 1 part by mass per 100 parts by mass of urethane prepolymer. This is because using more silane coupling agent than this may cause problems such as a lower modulus or lower adhesive strength in the resulting cured product. When the inventors evaluated compositions containing a urethane prepolymer and a latent curing agent by adding a silane coupling agent, etc., it became clear that such compositions sometimes exhibited poor heat resistance (Comparative Examples 2-9).

[0007] Therefore, the present invention aims to provide a urethane-based sealing material composition that has excellent adhesive properties and heat resistance. [Means for solving the problem]

[0008] As a result of diligent research to solve the above problems, the inventors of the present invention have found that a urethane-based sealing material composition containing 2 to 10 parts by mass of an epoxy compound having epoxy groups and hydrolyzable silyl groups, and 1 to 10 parts by mass of a latent curing agent, with respect to 100 parts by mass of urethane prepolymer, exhibits excellent adhesion and heat resistance, leading to the present invention. The present invention is based on the above findings, and specifically solves the above problems with the following configuration.

[0009] [1] Per 100 parts by mass of urethane prepolymer, 2 to 10 parts by mass of an epoxy compound having an epoxy group and a hydrolyzable silyl group, A urethane-based sealant composition containing 1 to 10 parts by mass of a latent curing agent. [2] The urethane-based sealant composition according to [1], wherein the urethane prepolymer has aromatic isocyanate residues. [3] The urethane-based sealing material composition according to [1] or [2], wherein the urethane prepolymer has a polyether structure. [4] The urethane-based sealant composition according to any one of [1] to [3], wherein the hydrolyzable silyl group is an alkoxysilyl group. [5] The urethane-based sealant composition according to any one of [1] to [4], wherein the epoxy group is a glycidyl group. [6] The urethane-based sealing material composition according to any one of [1] to [5], wherein the epoxy compound has one or more epoxy groups and hydrolyzable silyl groups in one molecule. [7] A urethane-based sealant composition according to any one of [1] to [6], wherein the latent curing agent comprises an oxazolidine compound. [Effects of the Invention]

[0010] The urethane-based sealant composition of the present invention exhibits excellent adhesion and heat resistance. [Modes for carrying out the invention]

[0011] The present invention will be described in detail below. In this specification, (meth)acrylic refers to acrylic or methacrylic. Furthermore, in this specification, a numerical range represented by "~" means the range that includes the numbers written before and after "~". In this specification, unless otherwise specified, each component may be composed of the substance corresponding to that component, either individually or in combination of two or more substances. If 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, the method of producing each component is not particularly limited. Examples include conventionally known methods. In this specification, a superior effect of the present invention means that at least one of the adhesive properties and heat resistance is superior.

[0012] [Urethane-based sealing material composition] The urethane-based sealing material composition of the present invention (the composition of the present invention) is With respect to 100 parts by mass of the urethane prepolymer, 2 to 10 parts by mass of an epoxy compound having an epoxy group and a hydrolyzable silyl group, and 1 to 10 parts by mass of a latent curing agent, and is a urethane-based sealing material composition.

[0013] Since the composition of the present invention has such a configuration, it is considered that the desired effects can be obtained. Although the reason is not clear, it is presumably as follows. A sealing material composition containing a urethane prepolymer and a latent curing agent cures by the reaction of the isocyanate group of the urethane prepolymer and the active hydrogen-containing group generated from the latent curing agent, and becomes a urethane-based cured product (sealing material). The above urethane-based cured product usually undergoes a decomposition reaction over time or under heating conditions, resulting in a decrease in modulus. On the other hand, when comparing the reactivity of the active hydrogen-containing group generated from the latent curing agent with respect to the isocyanate group of the urethane prepolymer and the reactivity of the epoxy group of the epoxy compound having an epoxy group and a hydrolyzable silyl group with respect to the above isocyanate group, the reactivity of the former is faster than that of the latter. In addition, the hydrolyzable silyl groups of the above epoxy compound can form crosslinks by siloxane bonds through a hydrolysis condensation reaction between the hydrolyzable silyl groups over time (over a long period of time). Thus, the composition of the present invention can form crosslinks by a relatively fast reaction between the isocyanate group of the urethane prepolymer and the active hydrogen-containing group generated from the latent curing agent, and further, crosslinks by a slow reaction between the isocyanate group of the urethane prepolymer and the epoxy group of the above epoxy compound, and crosslinks by siloxane bonds in which the hydrolyzable silyl groups of the above epoxy compound undergo a hydrolysis condensation reaction over time. Therefore, even if the urethane-based cured product undergoes a decomposition reaction over time or under heating conditions, causing a temporary decrease in modulus, the polymer matrix in the cured product can be maintained and the decrease in modulus can be restored or suppressed by the time-dependent reaction between the functional groups of the urethane prepolymer and the epoxy groups, and by the crosslinking that occurs over time due to the hydrolysis condensation reaction of the hydrolyzable silyl groups. For this reason, the composition of the present invention is presumed to have excellent adhesion and heat resistance. The above-described mechanism relating to the present invention is a speculation by the inventors and is not limited to that described above. The following describes in detail each component contained in the composition of the present invention.

[0014] <Urethane prepolymer> The composition of the present invention contains a urethane prepolymer. The above-mentioned urethane prepolymer is a urethane-based compound having an isocyanate group.

[0015] • Isocyanate group One preferred embodiment of the urethane prepolymer is one in which it has multiple isocyanate groups.

[0016] The above urethane prepolymer is preferably having aromatic isocyanate residues from the viewpoint of having superior effects of the present invention and high reactivity of the isocyanate group. In the above urethane prepolymer, the aromatic isocyanate residues refer to residues obtained by removing the isocyanate group from the aromatic polyisocyanate compound, when the polyisocyanate compound that can be used to form the urethane prepolymer contains an aromatic polyisocyanate compound. The urethane prepolymer preferably has isocyanate groups at its molecular ends.

[0017] • Polyether structure From the viewpoint of achieving superior effects of the present invention, the above-mentioned urethane prepolymer preferably has a polyether structure. The above-mentioned polyether structure is preferably derived from a polyether polyol, which can be used as a polyol compound to form the urethane prepolymer. Polyol compounds will be described later.

[0018] As the urethane prepolymer, for example, conventionally known ones can be used. Specifically, for example, a reaction product obtained by reacting a polyisocyanate compound with a compound having two or more active hydrogen-containing groups in one molecule (hereinafter abbreviated as "active hydrogen compound") such that there is an excess of isocyanate groups relative to the active hydrogen-containing groups can be used. In this invention, an active hydrogen-containing group means a group that contains active hydrogen. Examples of active hydrogen-containing groups include a hydroxyl group, an amino group (-NH2), and an imino group (-NH-).

[0019] (Polyisocyanate compounds) The polyisocyanate compounds used in the production of urethane prepolymers are not particularly limited as long as they have two or more isocyanate groups in their molecule. Examples of polyisocyanate compounds include aromatic polyisocyanate compounds such as toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), 1,4-phenylenediisocyanate, polymethylene polyphenylene polyisocyanate, xylylene diisocyanate (XDI), tetramethylxylylene diisocyanate (TMXDI), tollidine diisocyanate (TODI), 1,5-naphthalene diisocyanate (NDI), and triphenylmethane triisocyanate (aromatic polyisocyanate compounds only need to have at least an aromatic hydrocarbon group as the linking group to which the isocyanate group is attached). Hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate (TMHDI), lysine diisocyanate, norbornane diisocyanate (NBDI), transcyclohexane-1,4-diisocyanate, isophorone diisocyanate (IPDI), bis(isocyanate-methyl)cyclohexane (H6XDI), dicyclohexylmethane diisocyanate (H 12 Aliphatic polyisocyanates (where the above definition of aliphatic includes linear, branched, and alicyclic polyisocyanates), such as MDI; (In aliphatic polyisocyanates, the linking groups to which the isocyanate groups are attached are aliphatic hydrocarbon groups and do not have aromatic hydrocarbon groups.) These are examples of carbodiimide-modified polyisocyanates.

[0020] Polyisocyanate compounds can be used individually or in combination of two or more. From the viewpoint of having superior effects of the present invention and excellent reactivity of the isocyanate group, the polyisocyanate compounds that can constitute the urethane prepolymer preferably include aromatic polyisocyanate compounds, more preferably include MDI and TDI, and even more preferably include TDI.

[0021] (Active hydrogen compounds) The compounds (active hydrogen compounds) having two or more active hydrogen-containing groups in a single molecule used in the production of urethane prepolymers are not particularly limited. Examples of active hydrogen-containing groups include hydroxyl (OH) groups, amino groups, and imino groups.

[0022] Suitable examples of the above-mentioned active hydrogen compounds include polyol compounds having two or more hydroxyl (OH) groups in one molecule, and polyamine compounds having two or more amino groups and / or imino groups in one molecule. Among these, it is preferable to include a polyol compound from the viewpoint of providing superior effects and excellent degradation resistance.

[0023] The polyol compounds mentioned above are not particularly limited as long as they are compounds having two or more OH groups. Specific examples of polyol compounds include polyether polyols; polyester polyols; (meth)acrylic polyols; polybutadiene polyols, hydrogenated polybutadiene polyols; low molecular weight polyhydric alcohols; and mixed polyols thereof. In particular, for reasons that the effects of the present invention are superior, it is more preferable to include a polyether polyol and a polyester polyol, and even more preferable to include a polyether polyol.

[0024] Polyether polyols are not particularly limited as long as they are compounds having a polyether as the main chain and having two or more hydroxyl groups. A polyether is a group having two or more ether bonds, and a specific example of this is the structural unit -R a -OR b A group having a total of two or more - is an example. Here, in the above structural unit, R a and R b Each of these independently represents a hydrocarbon group. The hydrocarbon group is not particularly limited. For example, a linear alkylene group having 1 to 10 carbon atoms can be used. Examples of polyether polyols include polyoxyethylenediol (polyethylene glycol), polyoxypropylenediol (polypropylene glycol: PPG), polyoxypropylene triol, ethylene oxide / propylene oxide copolymer polyols, polytetramethylene ether glycol (PTMEG), polytetraethylene glycol, and sorbitol-based polyols. From the viewpoint of excellent compatibility with polyisoanate compounds, polypropylene glycol and polyoxypropylene triol are preferred as polyether polyols.

[0025] From the viewpoint of achieving superior effects of the present invention and forming a three-dimensional matrix in the resulting cured product, the above polyol compound preferably contains a trifunctional or higher polyol compound (a polyol compound having three or more hydroxyl groups), more preferably a trifunctional polyol compound, even more preferably a trifunctional polyether polyol and / or a trifunctional polyester polyol, and even more preferably a trifunctional polyether polyol.

[0026] When the above polyol compound includes a polyol compound with three or more functions, it is preferable to use a bifunctional polyol compound in combination, and it is even more preferable to use a trifunctional polyether polyol and a bifunctional polyether polyol in combination. When the above polyol compound includes a trifunctional or higher polyol compound and a bifunctional polyol compound, the amount of the trifunctional or higher polyol compound used is preferably 5 to 80% by mass of the total amount of the above polyol compound.

[0027] The weight-average molecular weight of the polyol compound (e.g., polyether polyol) that can constitute the urethane prepolymer is preferably 1,000 to 10,000, and more preferably 3,000 to 8,000, from the viewpoint of achieving superior effects of the present invention and ensuring that the urethane prepolymer obtained by reaction with the polyisocyanate compound has appropriate fluidity at room temperature (23°C). In the present invention, the above weight-average molecular weight is the polystyrene equivalent value obtained by the GPC method (solvent: tetrahydrofuran (THF)).

[0028] From the viewpoint of having superior effects of the present invention and excellent reactivity of the isocyanate group, the urethane prepolymer preferably contains a urethane prepolymer which is a reaction product of a polyisocyanate compound and a polyol compound, more preferably contains a urethane prepolymer which is an aromatic polyisocyanate compound and a polyol compound, even more preferably contains a urethane prepolymer which is a TDI or MDI and a polyether polyol, and still more preferably contains a urethane prepolymer which is a TDI and a polyether polyol.

[0029] From the viewpoint of achieving superior effects of the present invention, the isocyanate group content of the urethane prepolymer is preferably 1.0 to 10% by mass of the total amount of the urethane prepolymer.

[0030] The method for producing urethane prepolymers is not particularly limited. For example, a urethane prepolymer can be produced by using a polyisocyanate compound such that an excess amount of isocyanate groups reacts with 1 mole of active hydrogen-containing groups (e.g., hydroxyl groups) of an active hydrogen compound, and then mixing and reacting these compounds. The molar ratio (also called the index; expressed as NCO / OH when the active hydrogen-containing group is a hydroxyl group) of isocyanate groups in the polyisocyanate compound to the active hydrogen-containing groups in the active hydrogen compound is preferably 0.5 to 2.5, and more preferably 1.2 to 2.2, from the viewpoint of achieving superior effects of the present invention. Each urethane prepolymer can be used individually or in combination of two or more types.

[0031] <Epoxy compounds> The composition of the present invention contains an epoxy compound having an epoxy group and a hydrolyzable silyl group. The composition of the present invention, by containing the epoxy compound described above, is thought to be able to maintain the polymer matrix in the resulting cured product and restore the modulus reduction, even if the cured product decomposes over time or under heating conditions. This is achieved through the time-dependent reaction between the functional groups of the urethane prepolymer and the epoxy groups of the epoxy compound, and through crosslinking that occurs over time due to the hydrolysis condensation reaction of the hydrolyzable silyl groups of the epoxy compound. The function of the epoxy compound in restoring the modulus reduction of the resulting cured product is considered to be different from the function of conventional adhesion promoters. In this specification, epoxy compounds having the above-mentioned epoxy group and hydrolyzable silyl group may be referred to as "specific epoxy compounds."

[0032] <Epoxy group> The epoxy group of a specific epoxy compound is not particularly limited as long as it has an oxirane ring (structure shown below). [ka]

[0033] Examples of epoxy groups include epoxycycloalkyl groups such as glycidyl groups and epoxycyclohexyl groups.

[0034] From the viewpoint of achieving superior effects of the present invention, the epoxy group described above is preferably a glycidyl group. A specific epoxy compound may have one or more epoxy groups per molecule.

[0035] <Hydrolyzable silyl group> The hydrolyzable silyl group possessed by a specific epoxy compound is not particularly limited as long as it is hydrolyzable by water and contains a silicon atom. Examples of hydrolyzable silyl groups include alkoxysilyl groups, alkenyloxysilyl groups, acyloxysilyl groups, aminosilyl groups, aminooxysilyl groups, oximesilyl groups, and amidesilyl groups.

[0036] In particular, the hydrolyzable silyl group is preferably an alkoxysilyl group from the viewpoint of achieving superior effects in the present invention. Examples of alkoxysilyl groups include trialkoxysilyl groups, dialkoxysilyl groups, and monoalkoxysilyl groups. When the alkoxysilyl group is a dialkoxysilyl group or a monoalkoxysilyl group, other groups that can be further bonded to the silicon atom in the alkoxysilyl group (besides the alkoxy group) include, for example, hydrocarbon groups. Examples of such hydrocarbon groups include aliphatic hydrocarbon groups (including linear, branched, and cyclic), aromatic hydrocarbon groups, or combinations thereof. One preferred embodiment is that the hydrocarbon group is an alkyl group. Examples of the alkoxysilyl groups mentioned above include methyldimethoxysilyl group, methyldiethoxysilyl group, trimethoxysilyl group, and triethoxysilyl group.

[0037] From the viewpoint of achieving superior effects of the present invention, the above epoxy compounds preferably have one or more epoxy groups and one or more hydrolyzable silyl groups per molecule.

[0038] Examples of specific epoxy compounds include epoxy group-containing silane coupling agents and condensates of the above-mentioned epoxy group-containing silane coupling agents. From the viewpoint of achieving superior effects of the present invention, the specific epoxy compound preferably contains an epoxy group-containing silane coupling agent and / or a condensate of an epoxy group-containing silane coupling agent, and more preferably contains an epoxy group-containing silane coupling agent.

[0039] • Epoxy group-containing silane coupling agent The epoxy group-containing silane coupling agent mentioned above refers to a low-molecular-weight (so-called monomer) epoxy compound having an epoxy group and a hydrolyzable silyl group. The epoxy group-containing silane coupling agent described above may have one epoxy group and one hydrolyzable silyl group per molecule. In the epoxy group-containing silane coupling agent described above, the epoxy group and the hydrolyzable silyl group can be bonded via an organic group acting as a linking group.

[0040] ·Organic group Examples of the above-mentioned organic groups include hydrocarbon groups. Specifically, examples include aliphatic hydrocarbon groups (linear, branched, or cyclic), aromatic hydrocarbon groups, or combinations thereof. The above-mentioned hydrocarbon groups may have heteroatoms such as oxygen atoms, nitrogen atoms, and sulfur atoms.

[0041] When the specific epoxy compound is the epoxy group-containing silane coupling agent described above, the hydrolyzable silyl group is preferably an alkoxysilyl group, more preferably a dialkoxysilyl group or a trialkoxysilyl group, and even more preferably a trialkoxysilyl group, from the viewpoint of achieving superior effects of the present invention. More specifically, from the viewpoint of achieving superior effects of the present invention, the above-mentioned alkoxysilyl group is preferably a methyldimethoxysilyl group, a methyldiethoxysilyl group, a trimethoxysilyl group, or a triethoxysilyl group, with the trimethoxysilyl group and triethoxysilyl group being more preferred.

[0042] Examples of the epoxy group-containing silane coupling agents mentioned above include glycidoxyalkylalkoxysilanes such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylethyldimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, and 3-glycidoxypropylethyldiethoxysilane; Examples include epoxycycloalkylalkylalkoxysilanes such as 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. From the viewpoint of achieving superior effects of the present invention, the epoxy group-containing silane coupling agent described above preferably contains glycidoxyalkylalkoxysilane, more preferably contains glycidoxyalkyltrialkoxysilane, and even more preferably contains 3-glycidoxypropyltrimethoxysilane and 3-glycidoxypropyltriethoxysilane.

[0043] • Condensed product of epoxy group-containing silane coupling agent The condensate of the epoxy group-containing silane coupling agent refers to the hydrolysis condensate of the epoxy group-containing silane coupling agent described above. The above condensate is preferably a compound obtained by hydrolysis condensation of the epoxy group-containing silane coupling agent described above at the hydrolyzable silyl group. For this reason, the above condensate preferably has -(Si-O)n-Si- (n is preferably 2 to 10) as its main chain. When the specific epoxy compound is the above condensate, each silicon in the -(Si-O)n-Si- may constitute a hydrolyzable silyl group of the specific epoxy compound. Each silicon may also form a siloxane bond. Furthermore, if the specific epoxy compound is the above-mentioned condensate, the epoxy group can be bonded to the silicon atom in the main chain via an organic group. The organic group bonded to the epoxy group via the silicon atom is similar to the organic group that acts as a linking group between the epoxy group and the hydrolyzable silyl group in the above-mentioned epoxy group-containing silane coupling agent. The condensate of the epoxy group-containing silane coupling agent described above preferably has two or more epoxy groups and two or more hydrolyzable silyl groups per molecule.

[0044] From the viewpoint of providing superior effects of the present invention, the above condensate is preferably a condensate of glycidoxyalkyltrialkoxysilane, and more preferably a condensate of 3-glycidoxypropyltrimethoxysilane and / or 3-glycidoxypropyltriethoxysilane.

[0045] <Content of specific epoxy compounds> In the present invention, the content of the specific epoxy compound (an epoxy compound having an epoxy group and a hydrolyzable silyl group) is 2 to 10 parts by mass per 100 parts by mass of the above urethane prepolymer. The effects of the present invention are superior when the content of the specific epoxy compound is within the above range. From the viewpoint of achieving superior effects of the present invention, the content of the specific epoxy compound is preferably 3 to 8 parts by mass per 100 parts by mass of the urethane prepolymer.

[0046] • Content of epoxy group-containing silane coupling agent When the specific epoxy compound contains the epoxy group-containing silane coupling agent, the amount of the epoxy group-containing silane coupling agent is preferably 3 to 8 parts by mass per 100 parts by mass of the urethane prepolymer, from the viewpoint of achieving superior effects of the present invention.

[0047] • Content of condensate in epoxy group-containing silane coupling agents When the specific epoxy compound contains a condensate of the epoxy group-containing silane coupling agent, the content of the epoxy group-containing silane coupling agent condensate is preferably 3 to 8 parts by mass per 100 parts by mass of the urethane prepolymer, from the viewpoint of achieving superior effects of the present invention.

[0048] <Latent curing agent> The composition of the present invention contains a latent curing agent. The above-mentioned latent curing agent is one example of a preferred embodiment being a moisture-curing latent curing agent. The above-mentioned moisture-curing latent curing agent can be hydrolyzed by moisture (e.g., moisture in the air) to produce a curing agent having functional groups. The functional groups generated by the hydrolysis of the above-mentioned latent curing agent can react with the isocyanate groups of the above-mentioned urethane prepolymer and / or the epoxy groups of the specific epoxy compound. From the viewpoint of achieving superior effects of the present invention, the functional groups described above are preferably NH2 groups, NH groups, and hydroxyl groups, and more preferably NH groups and hydroxyl groups.

[0049] The curing agent produced by hydrolysis of the above-mentioned latent curing agent preferably has multiple of the above-mentioned functional groups per molecule.

[0050] Examples of the latent curing agents mentioned above include oxazolidine compounds, enamine compounds, silyl ether compounds, thiosilyl ether compounds, and ketimine compounds.

[0051] · Oxazolidine-based compound From the viewpoint that the effects of the present invention are more excellent, the latent curing agent preferably contains an oxazolidine-based compound. An oxazolidine-based compound is a compound having an oxazolidine ring in the molecule. An oxazolidine-based compound can have one or more oxazolidine rings per molecule, and from the viewpoint that the effects of the present invention are more excellent, it preferably has a plurality of them, and more preferably has two of them.

[0052] From the viewpoint that the effects of the present invention are more excellent, the above oxazolidine-based compound preferably contains a compound represented by the following formula (1).

Chemical formula

[0053] In formula (1), R 1 represents a hydrocarbon group, and R 2 represents a linking group having a valence of m + n, m is an integer from 1 to 4, and n is an integer from 0 to 4.

[0054] In the above formula (1), R 1 represents a hydrocarbon group. Examples of the above hydrocarbon group include an aliphatic hydrocarbon group (linear, branched, or cyclic), an aromatic hydrocarbon group, or a combination thereof. From the viewpoint that the effects of the present invention are more excellent, the above hydrocarbon group is preferably a hydrocarbon group having 3 or more carbon atoms, more preferably a hydrocarbon group having 3 to 20 carbon atoms, and even more preferably a hydrocarbon group having 3 to 15 carbon atoms. Examples of the hydrocarbon group as R 1 include isobutyl, n-pentyl, 2-methylpentyl, 3-methylpentyl, 3,5,5-trimethylpentyl, n-heptyl, n-octyl, n-nonyl, n-decanyl, n-undecanyl, n-dodecanyl, n-tridecanyl, n-tetradecanyl, etc.

[0055] In formula (1), R 2 This represents a linking group with m+n valence. The m+n valency is preferably 1 to 4. Examples of the linking groups include hydrocarbon groups. Examples of hydrocarbon groups include aliphatic hydrocarbon groups (linear, branched, or cyclic), aromatic hydrocarbon groups, or combinations thereof. The hydrocarbon groups may have heteroatoms such as oxygen atoms, nitrogen atoms, or sulfur atoms. Examples of the above-mentioned linking groups include aromatic groups such as triylene, diphenylmethane, phenylene, and polymethylene-polyphenylene groups; aliphatic groups such as hexamethylene groups; alicyclic hydrocarbon groups such as isophorone groups; aromatic aliphatic groups such as xylene groups; and carbodiimide-modified or isocyanurate-modified groups of these groups.

[0056] In equation (1), m is an integer between 1 and 4. In particular, a value between 2 and 3 is preferable in terms of curability and the physical properties of the cured product. In equation (1), n ​​is an integer between 0 and 4. In particular, it is preferable for n to be between 0 and 2 in terms of curability.

[0057] Examples of the oxazolidine compounds mentioned above include the latent curing agents I to V, each represented by the following structure. [ka]

[0058] From the viewpoint of achieving superior effects of the present invention, the above-mentioned latent curing agent preferably includes a latent curing agent represented by formula (IV) above.

[0059] <Content of latent hardening agent> In the present invention, the content of the latent curing agent is 1 to 10 parts by mass per 100 parts by mass of the urethane prepolymer. The effects of the present invention are superior when the content of the latent curing agent is within the above range.

[0060] From the viewpoint of achieving superior effects of the present invention, the content of the above-mentioned latent curing agent is preferably 3 to 8 parts by mass per 100 parts by mass of the above-mentioned urethane prepolymer.

[0061] (Other optional components) In addition to the above components, the compositions of the present invention may further contain, as necessary and without impairing the objectives of the present invention, various additives such as fillers (e.g., carbon black, calcium carbonate), dehydrating agents such as vinylsilane, plasticizers such as diisononyl phthalate and / or polyoxyalkylene resins, antioxidants, antioxidants, pigments, ultraviolet absorbers, flame retardants, surfactants, dispersants, and antistatic agents.

[0062] Calcium carbonate From the viewpoint of excellent workability, the composition of the present invention preferably further contains calcium carbonate.

[0063] The calcium carbonate is not particularly limited. Examples include conventionally known calcium carbonates. Specifically, examples include untreated calcium carbonate or surface-treated calcium carbonate. Untreated calcium carbonate and / or surface-treated calcium carbonate can be used as the calcium carbonate. Untreated calcium carbonate refers to calcium carbonate that has not undergone any surface treatment. The surface treatment agents used to treat calcium carbonate are not particularly limited. Examples include those that are conventionally known. If the composition of the present invention further contains calcium carbonate, the calcium carbonate content is preferably 20 to 500 parts by mass per 100 parts by mass of the urethane prepolymer.

[0064] • Dehydrating agent If the composition of the present invention further contains a dehydrating agent such as vinylsilane, the content of the dehydrating agent is preferably 0 to 3 parts by mass per 100 parts by mass of the urethane prepolymer. Vinylsilane refers to a compound having a vinyl group and a hydrolyzable silyl group. The hydrolyzable silyl group can be the same as described above. Examples of vinylsilanes include vinylsilane coupling agents such as vinyltrimethoxysilane.

[0065] (Manufacturing method) The composition of the present invention can be produced by mixing the above-mentioned urethane prepolymer, a specific epoxy compound, a latent curing agent, and the above-mentioned additives which can be used as needed.

[0066] The composition of the present invention can be used as a composition for sealing materials.

[0067] The composition of the present invention may be either a one-component type or a two-component type. A preferred embodiment of the composition of the present invention is that it is a one-component type.

[0068] Examples of substrates to which the composition of the present invention can be applied include concrete, wood, metal, glass, plastic, ceramic, and stone. The method for applying the composition of the present invention to a substrate is not particularly limited. For example, conventionally known methods can be used.

[0069] The composition of the present invention can be cured with moisture (for example, moisture in the air). The relative humidity is preferably 30 to 80% RH. The curing may occur at room temperature or under heated conditions. The composition of the present invention can become a urethane-based sealant (for example, a sealant having urethane bonds and / or urea bonds, etc.) after curing. [Examples]

[0070] The present invention will be specifically described below with reference to examples. However, the present invention is not limited to these examples.

[0071] <Production of the composition> Each component in Table 1 below was used in the composition (parts by mass) shown in the same table, and these were mixed in a stirrer to produce each composition.

[0072] <Rating> The following evaluations were performed using each composition (urethane-based sealant composition) manufactured as described above. The results are shown in Table 1. [Peel test (an evaluation test also known as the simple adhesion method)] (Preparation of test specimens) Each of the compositions manufactured as described above was applied to an aluminum substrate in the form of a bead with a width of 15 mm, a thickness of 3 mm, and a length of 50 mm. The substrate was then cured at 40°C for 5 days to prepare test specimens.

[0073] (Adhesiveness) Using the test specimens prepared as described above, a peel test (an evaluation test called a simple adhesion method) was performed under 23°C conditions, in which the cured material (sealant layer) of the composition was peeled off by hand at a 180° angle from each specimen. The "adhesion" was evaluated by visually observing the fracture state after the peel test according to the following criteria.

[0074] • Criteria for evaluating adhesion The results of the fracture state after the above peel test are shown below. ··C:CF (Coagulation and delamination of sealant) ·T:TCF (thin layer cohesive delamination) ··A: AF (Interfacial delamination) In the adhesion evaluation section, the number "100" listed alongside "C," etc., represents the sum of the percentages of each failure state relative to the entire adhesive surface. For example, "C+T 100" means that CF and TCF together accounted for 100% of the entire adhesive surface, meaning that AF was absent. In this invention, when the fracture state is CF and / or TCF, the adhesion is evaluated as excellent and is indicated by "○". On the other hand, if the fracture state was AF, it was evaluated as having poor adhesion.

[0075] (Heat resistance test) Using each test specimen prepared as described above, a heat resistance test was conducted by placing them at 100°C for 7 days.

[0076] (Heat resistance) For each test specimen prepared as described above, the Asker C hardness was measured using an Asker C hardness tester (manufactured by Polymer Instruments Co., Ltd.) in accordance with the Japan Rubber Association Standard (SRIS) 0101 before and after the heat resistance test, and the "heat resistance" was evaluated according to the following criteria.

[0077] • Evaluation criteria for heat resistance If the absolute value of the difference in Asker C hardness of the sealant layer before and after the above heat resistance test was 10.0 or less, it was evaluated as having excellent heat resistance and was indicated with "○". The absolute value of the difference in Asker C hardness between the above sealant layers was considered to be less than 10.0, indicating superior heat resistance. On the other hand, if the absolute value of the difference in Asker C hardness of the sealant layer exceeds 10.0, or if the Asker C hardness of the sealant layer could not be measured before or after the heat resistance test, the heat resistance was evaluated as poor and marked with "×". Regarding the evaluation results of the Asker C hardness of the sealant layer, a "-" is displayed if the Asker C hardness could not be measured (the measured value immediately returned to 0).

[0078] • Asker C hardness of the sealant layer before heat resistance testing The Asker C hardness of the sealant layer before the heat resistance test is preferably 40 or higher.

[0079] [Table 1]

[0080] The details of each component shown in Table 1 are as follows: (Urethane prepolymer) • Urethane prepolymer 1 (TDI type): Urethane prepolymer 1 prepared as follows 750 g of polyoxypropylene triol (trade name: Exenol 5030, number average molecular weight approximately 5000, manufactured by AGC), a polyether triol, and polyoxypropylene diol (trade name: Exenol 2020, number average molecular weight approximately 2000, manufactured by AGC), a polyether diol, were mixed in a mass ratio of 70 / 30, and the mixture was dehydrated under reduced pressure at 120°C. Toluene diisocyanate (trade name: Coronate T-80, manufactured by Tosoh Corporation) was added to the mixture in an amount such that the equivalent ratio of the NCO groups of the toluene diisocyanate to the OH groups of the above mixture (NCO / OH) was 1.7. These were mixed and stirred at 80°C for 24 hours under nitrogen purging to obtain urethane prepolymer 1. The NCO group content of the obtained urethane prepolymer 1 was 1.5% by mass of the total amount of urethane prepolymer 1.

[0081] • Urethane prepolymer 2 (HDI type): Urethane prepolymer 2 prepared as follows 750 g of polyoxypropylene triol (trade name: Exenol 5030, number average molecular weight approximately 5000, manufactured by AGC), a polyether triol, and polyoxypropylene diol (trade name: Exenol 2020, number average molecular weight approximately 2000, manufactured by AGC), a polyether diol, were mixed in a mass ratio of 70 / 30, and the mixture was dehydrated under reduced pressure at 120°C. Hexamethylene diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the mixture in an amount such that the equivalent ratio of the NCO groups of the hexamethylene diisocyanate to the OH groups of the above mixture (NCO / OH) was 1.7. These were mixed and stirred at 80°C for 24 hours under nitrogen purging to obtain urethane prepolymer 2. The NCO group content of the obtained urethane prepolymer 2 was 1.5% by mass of the total amount of urethane prepolymer 2.

[0082] • Urethane prepolymer 3 (XDI type): Urethane prepolymer 3 prepared as follows 750 g of polyoxypropylene triol (trade name: Exenol 5030, number average molecular weight approximately 5000, manufactured by AGC), a polyether triol, and polyoxypropylene diol (trade name: Exenol 2020, number average molecular weight approximately 2000, manufactured by AGC), a polyether diol, were mixed in a mass ratio of 70 / 30, and the mixture was dehydrated under reduced pressure at 120°C. Xylylene diisocyanate (manufactured by Tokyo Chemical Industry Co., Ltd.) was added to the mixture in an amount such that the equivalent ratio of the NCO groups of xylylene diisocyanate to the OH groups of the above mixture (NCO / OH) was 1.7. These were mixed and stirred at 80°C for 24 hours under nitrogen purging to obtain urethane prepolymer 3. The NCO group content of the obtained urethane prepolymer 3 was 1.5% by mass of the total amount of urethane prepolymer 3.

[0083] • Calcium carbonate: A mixture of surface-treated calcium carbonate (product name: Sealets 200, manufactured by Maruo Calcium Co., Ltd.) and heavy calcium carbonate (product name: Super S, manufactured by Maruo Calcium Co., Ltd.) (mass ratio of surface-treated calcium carbonate to heavy calcium carbonate = 3:1) • Dehydrating agent (vinylsilane): Vinyltrimethoxysilane, trade name KBM-1003, manufactured by Shin-Etsu Chemical Co., Ltd.

[0084] (Specific epoxy compounds) • Specific epoxy compound 1: 3-glycidoxypropyltrimethoxysilane (structure shown below). Trade name KBM-403, manufactured by Shin-Etsu Chemical Co., Ltd. [ka]

[0085] • Specific epoxy compound 2: A compound whose main chain skeleton is a linear polysiloxane (-Si-O-Si-O-Si-), and which has multiple alkoxysilyl groups and epoxy groups in one molecule. Each silicon atom in the above (-Si-O-Si-O-Si-) can form a hydrolyzable silyl group. Alkoxy group content: 17 wt%. Epoxy equivalent: 280 g / mol. Trade name: KR-516, manufactured by Shin-Etsu Chemical Co., Ltd.

[0086] • Comparative silane coupling agent: 3-methacryloxypropyltrimethoxysilane, trade name KBM-503, manufactured by Shin-Etsu Chemical Co., Ltd. • (Comparison) Epoxy resin: Bisphenol A type epoxy resin, product name EP-4100, manufactured by ADEKA Corporation.

[0087] (Latent curing agent) • Latent curing agent: A latent curing agent represented by the following formula (IV), prepared by reacting 100 g of 2-(1-methylbutyl)-3-oxazolidineethanol with 51.5 g of xylylene diisocyanate. When water reacts with the latent curing agent represented by formula (IV), the two oxazolidine rings undergo hydrolysis to produce -NH-CH2CH2-OH compounds. [ka]

[0088] • Plasticizer: A mixture of diisononyl phthalate (DINP, manufactured by Mitsubishi Chemical Corporation) and a polyoxyalkylene resin for dilution (product name LBU-25, manufactured by Sanyo Chemical Industries, Ltd. Note that LBU-25 does not contain active hydrogen groups) (mass ratio: DINP:LBU-25 = 6:10)

[0089] As is clear from the results shown in Table 1, Comparative Example 1, which did not contain the above-mentioned specific epoxy compound, exhibited poor adhesion and heat resistance. Comparative Examples 2 and 5, which contained less of the specified epoxy compound than required, exhibited poor heat resistance. Comparative Examples 3 and 6, which contained a higher-than-specified amount of the specific epoxy compound, exhibited poor heat resistance. Comparative Examples 4, 8, and 9, which did not contain the above-mentioned specific epoxy compound and instead contained a comparative silane coupling agent, exhibited poor adhesion and heat resistance. Comparative Example 7, which did not contain the above-mentioned specific epoxy compound and instead contained an epoxy resin, exhibited poor adhesion and heat resistance.

[0090] In contrast, the urethane-based sealing material composition of the present invention has excellent adhesion and heat resistance.

Claims

1. Per 100 parts by mass of urethane prepolymer, 3 to 8 parts by mass of an epoxy compound having an epoxy group and a hydrolyzable silyl group, It contains 1 to 10 parts by mass of a latent curing agent, The latent curing agent is a urethane-based sealant composition containing an oxazolidine compound, The urethane-based sealing material composition that does not contain either a urethane prepolymer sealed with a blocking agent or an isocyanate group blocking agent.

2. The urethane prepolymer has an aromatic isocyanate residue, The urethane-based sealing material composition according to claim 1, wherein the urethane prepolymer has a polyether structure.

3. The hydrolyzable silyl group is an alkoxysilyl group, The urethane-based sealant composition according to claim 1 or 2, wherein the epoxy group is a glycidyl group.

4. The urethane-based sealing material composition according to any one of claims 1 to 3, wherein the epoxy compound has one or more epoxy groups and one or more hydrolyzable silyl groups in one molecule.

5. Per 100 parts by mass of urethane prepolymer, An epoxy compound having an epoxy group and a hydrolyzable silyl group, 2 to 10 parts by mass, A urethane-based sealant composition containing 1 to 10 parts by mass of a latent curing agent, The latent curing agent comprises an oxazolidine compound, A urethane-based sealant composition wherein the content of the epoxy compound is in the range of 3 / 310 × 100 to 8 / 315 × 100 parts by mass per 100 parts by mass of the urethane-based sealant composition, The urethane-based sealing material composition that does not contain either a urethane prepolymer sealed with a blocking agent or an isocyanate group blocking agent.

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