Moisture-curable resin composition

Abstract

To provide a moisture-curable resin composition which has more excellent storage stability than before.SOLUTION: The moisture-curable resin composition contains: an alkyl (meth)acrylate-based polymer (P) having a crosslinkable silyl group; an amine (A) having an amino group and / or a latent amino group and having no crosslinkable silyl group; and a monoaminosilane (S) having a crosslinkable silyl group and having only one amino group in one molecule.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a moisture-curable resin composition. [Background technology]

[0002] Conventionally, a composition containing a polymer having a crosslinkable silyl group and two different ketimines with different melting points has been known as a moisture-curable resin composition for sealants (for example, Patent Document 1). By including two different ketimines, this composition is intended to improve the surface uniformity and stain resistance of the cured product obtained by curing the composition. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-077120 Summary of the Invention [Problem to be solved by the invention]

[0004] The present inventors have studied the moisture-curable resin composition described in Patent Document 1 and found that, depending on the composition and storage conditions, the storage stability is not necessarily sufficient, and there are disadvantages such as a decrease in workability over time and a shortened storage period, and that there is room for further improvement in storage stability.

[0005] In view of the above circumstances, an object of the present invention is to provide a moisture-curable resin composition having better storage stability than conventional compositions. [Means for solving the problem]

[0006] As a result of extensive research into the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by blending a monoaminosilane into a moisture-curable resin composition, and have arrived at the present invention. That is, the present inventors have found that the above problems can be solved by the following configuration.

[0007] [1] a (meth)acrylic acid alkyl ester polymer (P) having a crosslinkable silyl group; an amine (A) having an amino group and / or a latent amino group and not having a crosslinkable silyl group; A moisture-curable resin composition containing a crosslinkable silyl group and a monoaminosilane (S) having only one amino group per molecule. [2] 2. The moisture-curable resin composition according to claim 1, wherein the monoaminosilane (S) is present in an amount of 2 to 30% by mass relative to 100% by mass of the polymer (P). [3] The moisture-curable resin composition according to [1] or [2], wherein the monoaminosilane (S) is present in an amount of 25 to 400% by mass relative to 100% by mass of the amine (A). [4] The moisture-curable resin composition according to any one of [1] to [3], which is used as a composition for forming a sealant. [5] A step of preparing the moisture-curable resin composition according to any one of [1] to [4]; and curing the moisture-curable resin composition. [6] A sealant obtained by curing the moisture-curable resin composition according to any one of [1] to [4]. [Effects of the Invention]

[0008] As will be described below, the present invention can provide a moisture-curable resin composition having better storage stability than conventional compositions. DETAILED DESCRIPTION OF THE INVENTION

[0009] The moisture-curable resin composition of the present invention will be described below. In this specification, a numerical range expressed using "to" means a range that includes the numerical values ​​before and after "to" as the lower and upper limits. In this specification, each component may be used alone or in combination of two or more. When two or more components are used in combination, the content of the components refers to the total content unless otherwise specified. In this specification, (meth)acrylic means acrylic or methacrylic, and (meth)acrylate means acrylate or methacrylate.

[0010] [Moisture-curable resin composition] The moisture-curable resin composition of the present invention (hereinafter also referred to as "the composition of the present invention") is a moisture-curable resin composition containing a (meth)acrylic acid alkyl ester polymer (P) having a crosslinkable silyl group, an amine (A) having an amino group and / or a latent amino group but not a crosslinkable silyl group, and a monoaminosilane (S) having a crosslinkable silyl group and only one amino group per molecule.

[0011] It is believed that the composition of the present invention contains such ingredients and therefore exhibits the desired effects. The reason for this is not clear, but is presumed to be as follows. The (meth)acrylic acid alkyl ester polymer (P) having a crosslinkable silyl group has an ester bond in its molecule. This ester bond may undergo a side reaction with an amine (A) present in the composition to form an amide bond. If a composition containing such a polymer (P) contains a crosslinkable silyl group and a monoaminosilane (S) having only one amino group per molecule, this competes with the amine (A) in the side reaction, preventing the polymer (P) from reacting with the amine (A), which is thought to improve storage stability.

[0012] Each component contained in the composition of the present invention will be described below.

[0013] <Polymer (P)> The composition of the present invention contains a (meth)acrylic acid alkyl ester polymer (P) having a crosslinkable silyl group. The polymer (P) contains repeating units of a (meth)acrylic acid alkyl ester, and the alkyl group of the (meth)acrylic acid alkyl ester may be unsubstituted or may have a substituent. The polymer (P) may further contain repeating units other than the repeating units derived from the (meth)acrylic acid alkyl ester.

[0014] (Crosslinkable silyl group) The polymer (P) has a crosslinkable silyl group. The polymer (P) preferably has at least one crosslinkable silyl group per molecule. The polymer (P) preferably has a crosslinkable silyl group at its terminal. The crosslinkable silyl group can undergo a condensation reaction, for example, in the presence of moisture or the like, using a curing catalyst or the like.

[0015] The crosslinkable silyl group may be, for example, a hydrolyzable silyl group. The crosslinkable silyl group may contain a silanol group formed by hydrolysis of the hydrolyzable silyl group. The crosslinkable silyl group (hydrolyzable silyl group) may be, for example, a group in which at least one hydrolyzable group selected from the group consisting of a hydrogen atom, a halogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amide group, an acid amide group, an aminooxy group, a mercapto group, and an alkenyloxy group is bonded to a silicon atom.

[0016] (hydrolyzable group) The hydrolyzable group is preferably at least one selected from the group consisting of a hydrogen atom, an alkoxy group, an acyloxy group, a ketoximate group, an amino group, an amido group, an aminooxy group, a mercapto group, and an alkenyloxy group, more preferably an alkoxy group, and even more preferably a methoxy group.

[0017] The hydrolyzable silyl group is preferably a trialkoxysilyl group, more preferably a trimethoxysilyl group. When the polymer (P) contains two or more types of polymers, one type may be a polymer having a trialkoxysilyl group, and the other type may be a polymer having a dialkoxysilyl group (preferably a dimethoxysilyl group). When one or two of the hydrolyzable groups are bonded to one silicon atom, the groups that can be bonded to the silicon atom other than the hydrolyzable groups are not particularly limited, and examples thereof include hydrocarbon groups.

[0018] The crosslinkable silyl group may further have a siloxane bond in addition to the hydrolyzable silyl group. The siloxane bond may be divalent or higher. When the crosslinkable silyl group further has a siloxane bond, the siloxane bond can be bonded to the main chain. The siloxane bond is not particularly limited as long as it is -Si-O-. The organic group bonded to the silicon atom in the -Si-O- is not particularly limited. The siloxane bond may be a polysiloxane, and one preferred embodiment of the polysiloxane is a divalent polysiloxane.

[0019] <Bonding between the main chain and the crosslinkable silyl group> In the polymer (P), the crosslinkable silyl group can be bonded to the main chain directly or via an organic group, which is not particularly limited.

[0020] (molecular weight) The weight average molecular weight of the polymer (P) is preferably from 20,000 to 100,000, more preferably from 40,000 to 80,000. The weight average molecular weight is a value calculated in terms of standard polystyrene based on a measurement value obtained by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent.

[0021] (Content) In the composition of the present invention, the polymer (P) is preferably present in an amount of 10 to 90% by mass relative to the total mass of the composition, and more preferably 15 to 80% by mass.

[0022] <Amine (A)> The composition of the present invention contains an amine (A) which has an amino group and / or a latent amino group and does not have a crosslinkable silyl group.

[0023] <Amine (A-1)> The amine (A) may be an amine (A-1) having an amino group but not a crosslinkable silyl group. The amine (A-1) is preferably an alkylamine having at least one primary amino group per molecule. The primary amino group means -NH2. The amine (A) may also be an alkylamine having two or more primary amino groups per molecule.

[0024] (Alkyl group) The alkyl group of the amine (A-1) may be linear, branched, or cyclic. The amine (A-1) may have, for example, a structure in which one or more primary amino groups are attached to the terminal of a cyclic linear alkyl group, or a structure in which one or more primary amino groups are attached to the terminal of a linear alkyl group.

[0025] (Preferred embodiment) The alkyl group of the amine (A) preferably has 3 to 40 carbon atoms, more preferably 5 to 30 carbon atoms, even more preferably 10 to 25 carbon atoms, and even more preferably 15 to 20 carbon atoms. The amine (A) may be an amine that is solid at room temperature, such as stearylamine or cetylamine.

[0026] <Ketimine (K)> The amine (A) may be a ketimine (K). The ketimine (K) is a compound that generates an amine upon hydrolysis. The ketimine (K) is preferably a compound that generates an amine upon hydrolysis, which is an alkylamine having at least one primary amino group per molecule. The alkylamine generated by the hydrolysis is preferably the same as the amine (A-1).

[0027] <Carbonyl compounds> When ketimine (K) is hydrolyzed, carbonyl compound (C) is usually produced together with amine (A).

[0028] The carbonyl compound (C) is preferably a compound represented by R1C(=O)R2. Here, R1 and R2 each independently represent a hydrogen atom or a hydrocarbon group, and R1 and R2 may be bonded to each other to form a ring. Examples of the hydrocarbon group include an aliphatic hydrocarbon group, an aromatic hydrocarbon group, or a combination thereof, with aliphatic hydrocarbon groups being preferred. The aliphatic hydrocarbon group may be linear, branched, or cyclic. Specific examples of the aliphatic hydrocarbon group include alkyl groups, alkenyl groups, alkynyl groups, etc. Among these, alkyl groups are preferred because they provide better effects of the present invention. The number of carbon atoms in the hydrocarbon group is not particularly limited, but is preferably 1 to 10, for reasons such as better effects of the present invention.

[0029] Specific examples of the carbonyl compound (C) include methyl isopropyl ketone (MIPK), methyl t-butyl ketone (MTBK), methyl isobutyl ketone (MIBK), methyl cyclohexyl ketone, methyl cyclohexanone, etc. Among these, methyl isobutyl ketone (MIBK) is preferred.

[0030] <Manufacturing method> The ketimine (K) can be obtained, for example, by a method of subjecting the amine (A) to a dehydration reaction with the carbonyl compound (C).

[0031] <Content> In the composition of the present invention, the content of the amine (A) is preferably 1 to 50% by mass relative to 100% by mass of the polymer (P), more preferably 2 to 40% by mass, and even more preferably 5 to 30% by mass.

[0032] <Silane (S)> The composition of the present invention contains a monoaminosilane (S) having a crosslinkable silyl group and only one amino group per molecule. The crosslinkable silyl group of the monoaminosilane (S) is preferably a hydrolyzable silyl group.

[0033] (hydrolyzable silyl group) A hydrolyzable silyl group is a group in which a hydrolyzable bond is attached to a silicon atom. Specific examples of the hydrolyzable group are the same as the hydrolyzable group of the crosslinkable silyl group described above. The hydrolyzable group is preferably an alkoxy group, more preferably a methoxy group.

[0034] The hydrolyzable silyl group may be, for example, one in which 1 to 3 hydrolyzable groups are bonded to a silicon atom, and preferably three hydrolyzable groups are bonded to a silicon atom. When one or two hydrolyzable groups are bonded to a silicon atom, the other groups bonded to the silicon atom may be, for example, alkyl groups, such as methyl and ethyl groups. The hydrolyzable silyl group is preferably an alkoxysilyl group, more preferably a trimethoxysilyl group.

[0035] (organic group) The hydrolyzable silyl group and the amino group can be bonded via an organic group. The organic group may be, for example, an aliphatic hydrocarbon group (linear or branched) or an aromatic hydrocarbon group. Examples of the aliphatic hydrocarbon group include alkylene groups having 1 to 10 carbon atoms, such as methylene, ethylene, and trimethylene.

[0036] The silane (S) having a hydrolyzable silyl group and an amino group may be, for example, an aminoalkyltrialkoxysilane such as 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, 4-aminobutyltrimethoxysilane, and 4-aminobutyltriethoxysilane, with 3-aminopropyltriethoxysilane being preferred.

[0037] (Content) In the composition of the present invention, the monoaminosilane (S) is preferably present in an amount of 2 to 30% by mass relative to 100% by mass of the polymer (P), more preferably 3 to 25% by mass, even more preferably 4 to 20% by mass, and even more preferably 5 to 15% by mass.

[0038] (Content) In the composition of the present invention, the monoaminosilane (S) is preferably present in an amount of 25 to 400% by mass relative to 100% by mass of the amine (A), more preferably 30 to 350% by mass, even more preferably 35 to 300% by mass, even more preferably 40 to 250% by mass, and most preferably 50 to 200% by mass.

[0039] [Optional ingredients] The composition of the present invention may contain components (optional components) other than the above-mentioned components. Examples of such optional components include fillers, plasticizers, solvents (thickening agents), catalysts (curing catalysts), thixotropic agents, dehydrating agents, and antioxidants.

[0040] <Filler> The compositions of the present invention may contain fillers. Examples of the filler include fillers that are generally used in moisture-curable resin compositions, and specific examples include calcium carbonate, talc, silica, and carbon black. The filler is preferably calcium carbonate because it provides better effects of the present invention. Specific examples of calcium carbonate include colloidal calcium carbonate, heavy calcium carbonate, and light calcium carbonate.

[0041] (Content) In the composition of the present invention, the content of the filler is preferably 50 to 400 mass% and may be 100 to 300 mass% relative to 100 mass% of the above-mentioned polymer (P), for reasons such as better effects of the present invention.

[0042] <Plasticizer> The composition of the present invention may contain a plasticizer. The plasticizer is preferably a polymer having a weight-average molecular weight of 400 to 11,000. Specific examples include phthalate esters such as dioctyl phthalate, dibutyl phthalate, and butyl benzyl phthalate, polyalkylene oxides such as polypropylene glycol, and acrylic polymers. Of these, acrylic polymers are preferred. The acrylic polymer preferably does not contain a hydrolyzable silyl group.

[0043] (Content) In the composition of the present invention, the content of the plasticizer is preferably 20 to 400 mass %, more preferably 30 to 300 mass %, and even more preferably 50 to 200 mass %, relative to 100 mass % of the polymer (P). <Catalyst> The composition of the present invention may contain a catalyst (curing catalyst). The curing catalyst is a compound capable of hydrolyzing and / or condensing the crosslinkable silyl group.

[0044] The curing catalyst may include a tin catalyst.

[0045] Examples of tin catalysts include metal carboxylates such as tin octoate, tin butanoate, tin caprylate, and tin oleate; organic tin compounds such as dibutyltin diacetate, dibutyltin dioctoate, dibutyltin dilaurate, dibutyltin dioleate, dioctyltin dilaurate, diphenyltin diacetate, dibutyltin oxide, reaction products of dibutyltin oxide and phthalic acid ester, dibutyltin dimethoxide, and dibutyltin(triethoxysiloxy); tin chelate compounds such as dibutyltin diacetylacetonate; tin oxides such as dibutyltin oxide and dioctyltin oxide; and diisononyl phthalate (DINP)-modified tin.

[0046] (Content) In the composition of the present invention, the content of the curing catalyst is preferably from 0.05 to 5% by mass, and more preferably from 0.1 to 3% by mass, relative to 100% by mass of the polymer (P).

[0047] [Manufacturing method] The composition of the present invention can be produced, for example, by mixing the above-mentioned components.

[0048] [Application] Substrates to which the compositions of the present invention can be applied may be, for example, glass, plastic, rubber, wood, metal, asphalt, stone, or porous materials. The composition of the present invention is particularly useful as a sealant for exterior walls (for example, siding boards) and the like. The composition of the present invention cures, for example, due to moisture in the air. [Example]

[0049] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0050] [Synthesis of Ketimines] Stearylamine (Melting point: 53°C, CH3(CH2) 17Ketimine (K-1) was synthesized by dehydration of NH2) with methyl isobutyl ketone (MIBK).

[0051] [Preparation of moisture-curable resin composition] Each moisture-curable resin composition was prepared by mixing the components shown in Tables 1 and 2 below in the proportions (mass %) shown in the tables.

[0052] 〔evaluation〕 The viscosity of each of the obtained moisture-curable resin compositions was measured as follows.

[0053] <Viscosity> Each moisture-curable resin composition obtained was sealed in a glass container and allowed to stand at 80°C for 28 days. The viscosity (Pa·S) of each moisture-curable resin composition was measured initially, after 3 days, after 7 days, and after 28 days. Viscosity was measured using an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., with a standard cone rotor) at a rotation speed of 1 rpm or 0.5 rpm and 23°C (unit: Pa·s). RC represents the percentage change from the initial viscosity.

[0054] [Table 1]

[0055] [Table 2]

[0056] Details of each component in Tables 1 and 2 are as follows:

[0057] Polymer (P-1): Polyoxypropylene with trimethoxysilyl groups at both ends (product name SAX220, corresponding to Polymer (P), manufactured by Kaneka Corporation) Polymer (P-2): A modified polymer having a methyldimethoxysilyl group at the end and a poly(meth)acrylate skeleton in the main chain (product name SA410S, corresponding to Polymer (P), manufactured by Kaneka Corporation) Polymer (P-3): SB803S (a mixture of SA410S and SAX220 in a mass ratio of 70:30) Stearylamine-MIBK ketimine: The compound mentioned above, which corresponds to ketimine (K). Diaminosilane (product name: KBM-603, having the following structure, manufactured by Shin-Etsu Chemical Co., Ltd.) (CH3O)3SiC3H6NHC2H4NH2 Epoxysilane: (Product name: KBM-403, having the following structure, manufactured by Shin-Etsu Chemical Co., Ltd.) TIFF2025168778000003.tif26123·Monoaminosilane (product name: KBM-903, having the following structure, manufactured by Shin-Etsu Chemical Co., Ltd.) (CH3O)3SiC3H6NH2 NBDA: Norbornanediamine (bis(aminomethyl)norbornane (mixture of isomers) having the following structure, manufactured by Tokyo Chemical Industry Co., Ltd.) TIFF2025168778000004.tif2056 · Plasticizer: Non-functional acrylic plasticizer (product name: ARUFON (registered trademark) UP-1110, manufactured by Toagosei Co., Ltd.) Moisture remover: Vinyl silane coupling agent (product name SILQUEST A-171, manufactured by Nissho Sangyo Co., Ltd.)

[0058] As can be seen from Table 1, Example 1, which contains polymer (P), amine (A), and monoaminosilane (S), showed a suppressed increase in viscosity over time compared to Comparative Examples 1 to 9, and had particularly excellent storage stability.

Claims

1. a (meth)acrylic acid alkyl ester polymer (P) having a crosslinkable silyl group; an amine (A) having an amino group and / or a latent amino group but not having a crosslinkable silyl group; A moisture-curable resin composition containing a crosslinkable silyl group and a monoaminosilane (S) having only one amino group per molecule.

2. The moisture-curable resin composition according to claim 1, wherein the monoaminosilane (S) is present in an amount of 2 to 30% by mass relative to 100% by mass of the polymer (P).

3. The moisture-curable resin composition according to claim 1, wherein the monoaminosilane (S) is present in an amount of 25 to 400% by mass relative to 100% by mass of the amine (A).

4. The moisture-curable resin composition according to claim 1, which is used as a composition for forming a sealant.

5. A step of preparing the moisture-curable resin composition according to claim 1; and curing the moisture-curable resin composition.

6. A sealant obtained by curing the moisture-curable resin composition according to claim 1.

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