Sound-insulating composition

Abstract

To provide a sound-insulating composition that has a low viscosity, exhibits excellent fillability into a sealing portion or excellent applicability to a desired location, and can generate a cured product having superior sound insulation properties.SOLUTION: The sound-insulating composition of the present invention contains 100 pts.mass of a polymer having a hydrolyzable silyl group, the polymer having a structure represented by formula (1) and having a number-average molecular weight of 13,000 to 50,000, and 10 to 100 pts.mass of a plasticizer, and is characterized in that the composition has a specific gravity of 1.6 or more, a viscosity at 23°C measured under a condition of 10 rpm of 700,000 mPa s or less, and a thixotropy of 5 or more.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a sound-insulating composition. [Background technology]

[0002] Conventionally, sound-insulating compositions containing oxyalkylene polymers having crosslinkable hydrolyzable silyl groups have been known (for example, Patent Document 1). The sound-insulating compositions produce cured products with excellent adhesiveness by hydrolyzing the crosslinkable hydrolyzable silyl groups due to moisture in the atmosphere and then dehydrating and condensing them.

[0003] In recent years, sound insulation has been required in rooms of buildings. Rooms of buildings are constructed by arranging and fixing panels and filling sealing portions formed between adjacent panels with a sealing material.

[0004] Even if the sound insulation of the panels is improved, if the sound insulation of the sealant filled in the sealing portion formed between the panels is low, sound will enter from outside through the sealant, resulting in a decrease in sound insulation inside the room.

[0005] Patent Document 1 discloses a sound-insulating composition containing (A) 100 parts by mass of a reactive silicon group-containing organic polymer having a number-average molecular weight of 2,000 to 6,000 and containing 1.3 to 5 reactive silicon groups per molecule, and (C) 0 to 40 parts by mass of a plasticizer, as a sealant to be filled in the sealing portion formed between panels.

[0006] Patent Document 2 discloses a method for producing a sound-insulating composition comprising (A) an organic polymer having a silicon-containing group capable of crosslinking by forming a siloxane bond and (B) heavy calcium carbonate, in which the content of the heavy calcium carbonate (B) is 30 to 500 parts by mass per 100 parts by mass of the organic polymer (A), and the amount of surface-treated heavy calcium carbonate in the heavy calcium carbonate (B) is less than 60% by weight. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] WO2012 / 070476 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-242506 Summary of the Invention [Problem to be solved by the invention]

[0008] On the other hand, it is generally known as the mass law that the greater the specific gravity, the higher the reflective performance for reflecting sound waves, and the better the sound insulation.

[0009] However, when the specific gravity of the sound-insulating composition is increased, the viscosity increases, making it difficult to fill the sealing portions formed between panels without leaving any gaps, and the flexibility and elongation of the cured product produced also decrease, causing gaps to form as the sealing portions change, resulting in a decrease in sound insulation. Conversely, when an attempt is made to improve the gap-filling ability of the sound-insulating composition, the sound insulation of the cured product of the sound-insulating composition also decreases.

[0010] Furthermore, the sound insulating composition has the problem that the plasticizer contained therein oozes out and impairs the appearance of the member that constitutes the sealing portion.

[0011] The present invention provides a sound-insulating composition that solves the conflicting problems of sound insulation and low viscosity, flexibility, and elongation, while suppressing deterioration in appearance due to exudation of plasticizers, and that maintains low viscosity while increasing the specific gravity, and has excellent fillability into sealing areas or applicability to desired locations.

[0012] To provide a sound-insulating composition which has excellent sound-insulating properties, maintains excellent flexibility and elongation, smoothly follows the deformation of a coated or filled part to prevent the formation of gaps, and can maintain excellent sound-insulating properties, and further can produce a cured product in which the exudation of a plasticizer is reduced and the deterioration of appearance is reduced. [Means for solving the problem]

[0013] The sound-insulating composition of the present invention comprises: The composition comprises 100 parts by mass of a polymer having a hydrolyzable silyl group, which has a structure represented by formula (1) and a number average molecular weight of 13,000 to 50,000, and 10 to 100 parts by mass of a plasticizer, and the composition has a specific gravity of 1.6 or more, a viscosity of 700,000 mPa s or less at 23°C measured at 10 rpm, and a thixotropy of 5 or more. [ka] However, in formula (1), R 1 represents an alkylene group having 1 to 14 carbon atoms, and x, y, and z are each the number of repeating units and are positive integers. 2 represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, or a hydrogen atom. 3 represents an alkyl group having 1 to 6 carbon atoms. k represents an integer of 0 to 2. 1 , R 2 and R 3 may be the same or different from each other. When there are multiple k's, they may be the same or different from each other. [Effects of the Invention]

[0014] The sound-insulating composition of the present invention has low viscosity and is excellent in terms of fillability into coated or sealed areas and applicability to desired locations. In addition, since the specific gravity is 1.6 or more, the cured product produced by curing has excellent sound-insulating properties, and furthermore, the cured product maintains excellent flexibility and elongation.

[0015] Therefore, the sound-insulating composition of the present invention can be easily filled without gaps in the sealing portion formed between panels, or can be applied to fit the shape of the desired location. Furthermore, the cured product (hereinafter sometimes simply referred to as the "cured product") produced by curing the sound-insulating composition has excellent sound insulation properties. Therefore, the sealing portion formed between panels is filled without gaps with the cured product with excellent sound insulation properties, and a space with excellent sound insulation properties can be easily created. Furthermore, the cured product can be produced to fit the shape of the coating location, and excellent sound insulation can be imparted to the desired location. The cured product of the sound-insulating composition has excellent flexibility and extensibility, so it smoothly deforms in response to deformation of the substrate, such as the sealing portion, and can stably maintain the filled state of the substrate, such as the sealing portion, and maintain excellent sound insulation properties.

[0016] Furthermore, the cured product of the sound-insulating composition has reduced exudation of the plasticizer contained in the cured product, which reduces contamination of the substrate due to exudation of the plasticizer and allows the appearance of the substrate to be maintained in good condition. DETAILED DESCRIPTION OF THE INVENTION

[0017] The sound-insulating composition of the present invention comprises 100 parts by mass of a polymer having a hydrolyzable silyl group, which has a structure represented by formula (1) and a number-average molecular weight of 13,000 to 50,000, and 10 to 120 parts by mass of a plasticizer, and the sound-insulating composition has a specific gravity of 1.6 or more, a viscosity of 700,000 mPa s or less at 23°C measured at 10 rpm, and a thixotropy index of 5 or more.

[0018] [ka]

[0019] However, in formula (1), R 1 represents an alkylene group having 1 to 14 carbon atoms, and x, y, and z are each the number of repeating units and are positive integers. 2 represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, or a hydrogen atom. 3represents an alkyl group having 1 to 6 carbon atoms. k represents an integer of 0 to 2. 1 , R 2 and R 3 may be the same or different from each other. When there are multiple k's, they may be the same or different from each other.

[0020] In the sound-insulating composition, the total content of the polymer having a hydrolyzable silyl group, which has a structure represented by formula (1) and has a number-average molecular weight of 13,000 to 50,000, and the plasticizer is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 99% by mass or more, and more preferably 100% by mass.

[0021] [Polymers containing hydrolyzable silyl groups] The sound-insulating composition contains a polymer having a hydrolyzable silyl group and a structure represented by formula (1) and a number-average molecular weight of 13,000 to 50,000. The polymer having a hydrolyzable silyl group crosslinks to form a crosslinked structure due to atmospheric moisture (water) or moisture (water) contained in a member (substrate) such as a sealing portion (joint portion) into which the sound-insulating composition is filled or a substrate to which the sound-insulating composition is applied, thereby producing a cured product with sound-insulating properties. The polymer having a hydrolyzable silyl group may be used alone or in combination of two or more types.

[0022] The polymer having a hydrolyzable silyl group has a structure shown in formula (1).

[0023] [ka]

[0024] However, in formula (1), R 1 represents an alkylene group having 1 to 14 carbon atoms, and x, y, and z are each the number of repeating units and are positive integers. 2 represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, or a hydrogen atom.3 represents an alkyl group having 1 to 6 carbon atoms. k represents an integer of 0 to 2. 1 , R 2 and R 3 may be the same or different from each other. When there are multiple k's, they may be the same or different from each other. x is preferably 60 to 150, more preferably 70 to 140, and more preferably 75 to 130. y is preferably 60 to 150, more preferably 70 to 140, and more preferably 75 to 130. z is preferably 60 to 150, more preferably 70 to 140, and more preferably 75 to 130.

[0025] The content of the polyoxyalkylene polymer having a hydrolyzable silyl group having the structure represented by formula (1) in the polymer having a hydrolyzable silyl group is preferably 50% by mass or more, more preferably 60% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, more preferably 95% by mass or more, more preferably 99% by mass or more, and more preferably 100% by mass.

[0026] A polymer having a hydrolyzable silyl group and having the structure shown in formula (1) has a hydrolyzable silyl group in the molecule and at the molecular terminal. When the hydrolyzable silyl group is bonded to the terminal of the main chain, the cured product of the sound-insulating composition has excellent flexibility and excellent sound insulation due to the chain extension effect during curing. Note that when the polymer having a hydrolyzable silyl group has multiple hydrolyzable silyl groups in the molecule, the hydrolyzable silyl groups may be the same or different from each other.

[0027] The hydrolyzable silyl group refers to a group that undergoes a condensation reaction in the presence of moisture or a crosslinking agent, and if necessary, using a catalyst, such as a silicon-containing group or a silanol group having a hydrolyzable group bonded to a silicon atom. The silanol group refers to a functional group [≡Si-OH, formula (2)] in which a hydroxyl group (-OH) is directly bonded to a silicon atom. In formula (2), *1 to *3 are bonds and represent single bonds.

[0028] [ka]

[0029] The hydrolyzable group of the hydrolyzable silyl group is not particularly limited, and examples thereof include 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.

[0030] Among these, an alkoxysilyl group is preferred as the hydrolyzable silyl group. The sound-insulating composition can be filled or coated in accordance with the shape of the filled or coated portion, and excellent sound insulation can be imparted to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed portion is improved, and the cured product can be filled into the sealed portion without any gaps, thereby improving the sound insulation in the sealed portion.

[0031] The alkoxysilyl group is -SiR 4 j (OR 5 ) 3-j Preferably, the compound has a structure represented by the formula: 4 represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, or a hydrogen atom. 5 represents an alkyl group having 1 to 6 carbon atoms, and j represents an integer of 0 to 2.

[0032] Examples of alkoxysilyl groups include trialkoxysilyl groups such as trimethoxysilyl, triethoxysilyl, triisopropoxysilyl, and triphenoxysilyl; dialkoxysilyl groups such as propyldimethoxysilyl, methyldimethoxysilyl, and methyldiethoxysilyl; and monoalkoxysilyl groups such as dimethylmethoxysilyl and dimethylethoxysilyl. The sound-insulating composition can be filled or coated according to the shape of the filling or coating portion, thereby imparting excellent sound insulation to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed portion is improved, allowing the cured product to be filled into the sealed portion without gaps, thereby improving the sound insulation in the sealed portion. Therefore, as the alkoxysilyl group, dialkoxysilyl and trialkoxysilyl groups are preferred, and dimethoxysilyl and trimethoxysilyl groups are preferred.

[0033] The polymer having a hydrolyzable silyl group has a structure shown in the above formula (1). In the polymer having a hydrolyzable silyl group having a structure shown in formula (1), the hydrolyzable silyl group is preferably an alkoxysilyl group, more preferably a dialkoxysilyl group or a trialkoxysilyl group, more preferably a dialkoxysilyl group, and more preferably a dimethoxysilyl group.

[0034] The polyoxyalkylene polymer constituting the polymer having the structure shown in formula (1) is a polymer having a main chain represented by the general formula: -(RO) m - (wherein R represents an alkylene group having 1 to 14 carbon atoms, and m represents the number of repeating units and is a positive integer.) The main chain skeleton of the polyoxyalkylene polymer may be composed of only one type of repeating unit, or may be composed of two or more types of repeating units.

[0035] The polymer having a hydrolyzable silyl group having the structure shown in formula (1) is represented by the general formula: -(RO) m -Contains a repeating unit represented by the general formula: -(RO) mThe repeating unit represented by - (wherein R represents an alkylene group having 1 to 14 carbon atoms, and m represents the number of repeating units and is a positive integer) may contain only one type of repeating unit, or may contain two or more types of repeating units.

[0036] The polymer having a hydrolyzable silyl group has a structure shown in the following formula (1). When the polymer having a hydrolyzable silyl group has the structure shown in formula (1), the sound-insulating composition can be maintained at a low viscosity while increasing the specific gravity of the sound-insulating composition, and the sound-insulating composition can be filled or coated in accordance with the shape of the filled or coated portion, thereby imparting excellent sound insulation to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed portion is improved, and the cured product can be filled into the sealed portion without gaps, thereby improving the sound insulation in the sealed portion. Furthermore, it is possible to reduce the seepage of plasticizer onto the surface of the cured product and the contamination of the surface of the substrate, such as a panel or a coated body. In formula (1), R 1 represents an alkylene group having 1 to 14 carbon atoms, and x, y, and z are each the number of repeating units and are positive integers. 2 represents an alkyl group having 1 to 20 carbon atoms (e.g., methyl group, ethyl group, propyl group, butyl group, pentyl group, etc.) which may have a substituent, or a hydrogen atom. 3 represents an alkyl group having 1 to 6 carbon atoms (e.g., methyl, ethyl, propyl, butyl, pentyl, hexyl, etc.); k represents an integer of 0 to 2; 1 , R 2 and R 3 may be the same or different from each other. When there are multiple k's, they may be the same or different from each other.

[0037] [ka]

[0038] In formula (1), R 1is preferably an alkylene group having 1 to 4 carbon atoms, more preferably an alkylene group having 1 to 3 carbon atoms, more preferably an alkylene group having 2 or 3 carbon atoms, and more preferably a propylene group [—CH(CH3)—CH2—]. 2 is preferably a hydrogen atom. 3 is preferably a methyl group or an ethyl group, and more preferably a methyl group. x is preferably 60 to 150, and more preferably 70 to 140. y is preferably 60 to 150, and more preferably 70 to 140. z is preferably 60 to 150, and more preferably 70 to 140.

[0039] In the present invention, an alkylene group refers to a divalent atomic group generated by abstracting one hydrogen atom bonded to each different carbon atom in an aliphatic saturated hydrocarbon, or a divalent atomic group generated by abstracting two hydrogen atoms from methane, and includes both linear and branched atomic groups.

[0040] Examples of alkylene groups include methylene groups [-CH2-], ethylene groups [-CH2-CH2-], propylene groups [-CH(CH3)-CH2-], trimethylene groups [-CH2-CH2-CH2-], butylene groups, amylene groups [-(CH2)5-], and hexylene groups.

[0041] Examples of the main chain skeleton of the polyoxyalkylene polymer include polyethylene oxide, polypropylene oxide, polybutylene oxide, polytetramethylene oxide, polyethylene oxide-polypropylene oxide copolymer, and polypropylene oxide-polybutylene oxide copolymer. Among these, polypropylene oxide is preferred. When polypropylene oxide is used, the cured product of the sound-insulating composition has excellent flexibility and excellent sound insulation properties.

[0042] The number average molecular weight of the polymer having a hydrolyzable silyl group having the structure shown in formula (1) is 13,000 or more, preferably 14,000 or more, and more preferably 15,000 or more. The number average molecular weight of the polymer having a hydrolyzable silyl group having the structure shown in formula (1) is 50,000 or less, preferably 40,000 or less, more preferably 35,000 or less, more preferably 32,000 or less, more preferably 30,000 or less, more preferably 25,000 or less, and more preferably 20,000 or less. When the number average molecular weight of the polymer having a hydrolyzable silyl group having the structure shown in formula (1) is 13,000 or more, the exudation of the plasticizer to the surface of the cured product is reduced, and migration to the surface of substrates such as panels and coated bodies, which causes contamination of the substrate surface, is reduced. When the number-average molecular weight of the polymer having a hydrolyzable silyl group and having the structure represented by formula (1) is 50,000 or less, the sound-insulating composition can be filled or coated in accordance with the shape of the filled or coated portion, and excellent sound insulation can be imparted to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed portion is improved, and the cured product can be filled into the sealed portion without any gaps, thereby improving the sound insulation in the sealed portion.

[0043] The molecular weight distribution (Mw / Mn) of the polymer having a hydrolyzable silyl group and having the structure represented by formula (1) is preferably 2.0 or less, more preferably 1.8 or less, and even more preferably 1.5 or less. When the molecular weight distribution (Mw / Mn) of the polymer having a hydrolyzable silyl group and having the structure represented by formula (1) is 2.0 or less, the sound-insulating composition can be filled or coated in accordance with the shape of the filled or coated portion, and excellent sound insulation can be imparted to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed portion is improved, and the cured product can be filled into the sealed portion without any gaps, thereby improving the sound insulation in the sealed portion.

[0044] In the present invention, the number-average molecular weight and weight-average molecular weight of the polymer having the structure shown in formula (1) and having a hydrolyzable silyl group are values ​​measured by GPC (gel permeation chromatography) in terms of polystyrene. Specifically, 6 to 7 mg of the polymer having the structure shown in formula (1) and having a hydrolyzable silyl group is collected, and the collected polymer having a hydrolyzable silyl group is placed in a test tube. An o-DCB (ortho-dichlorobenzene) solution containing 0.05% by mass of BHT (dibutylhydroxytoluene) is added to the test tube, and the polymer having the structure shown in formula (1) and having a hydrolyzable silyl group is diluted to a concentration of 1 mg / mL to prepare a diluted solution.

[0045] The diluted solution is shaken at 25 rpm at 145°C for 1 hour using a dissolution filter to dissolve the polymer having a hydrolyzable silyl group in the o-DCB solution containing BHT, thereby preparing a measurement sample. The number-average molecular weight and weight-average molecular weight of the polymer having the structure shown in formula (1) and having a hydrolyzable silyl group can be measured by GPC using this measurement sample.

[0046] The number average molecular weight and weight average molecular weight of a polymer having the structure represented by formula (1) and containing a hydrolyzable silyl group can be measured, for example, using the following measuring device and under the following measuring conditions. Measuring device: TOSOH Corporation, product name "HLC-8121GPC / HT" Measurement conditions Column: TSKgelGMHHR-H(20)HT x 3 TSKguardcolumn-HHR(30)HT x 1 Mobile phase: o-DCB 1.0mL / min Sample concentration: 1 mg / mL Detector: Bryce type refractometer Standard material: Polystyrene (TOSOH Corporation, molecular weight: 500-8420000) Elution conditions: 145℃ SEC temperature: 145℃

[0047] The polymer having the structure shown in formula (1) and a hydrolyzable silyl group can be commercially available. For example, examples of polyoxyalkylene polymers having a hydrolyzable silyl group include "SAX260" manufactured by Kaneka Corporation and "S6250" manufactured by AGC.

[0048] [Acrylic polymer having hydrolyzable silyl groups] The sound-insulating composition may contain an acrylic polymer having a hydrolyzable silyl group. The hydrolyzable silyl group possessed by the acrylic polymer is preferably a trialkoxysilyl group. Examples of the trialkoxysilyl group include a trimethoxysilyl group, a triethoxysilyl group, a triisopropoxysilyl group, and a triphenoxysilyl group, with a trimethoxysilyl group being preferred. When the hydrolyzable silyl group possessed by the acrylic polymer is a trialkoxysilyl group, the sound-insulating composition can be filled or coated in accordance with the shape of the filled or coated portion, thereby imparting excellent sound insulation to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed portion is improved, the cured product can be filled into the sealed portion without gaps, and the sound insulation in the sealed portion can be improved.

[0049] The acrylic polymer having hydrolyzable silyl groups preferably has an average of 2.0 to 5.0, and more preferably 3.0 to 4.0, hydrolyzable silyl groups per molecule. When the average number of hydrolyzable silyl groups per molecule of the acrylic polymer having hydrolyzable silyl groups is 2.0 or more, the curing properties of the sound-insulating composition are improved. When the average number of hydrolyzable silyl groups per molecule of the acrylic polymer having hydrolyzable silyl groups is 4.0 or less, the sound-insulating composition can be filled or coated in accordance with the shape of the filled or coated portion, thereby imparting excellent sound insulation to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling properties into the sealed portion are improved, and the cured product can be filled into the sealed portion without any gaps, thereby improving the sound insulation properties of the sealed portion.

[0050] The average number of hydrolyzable silyl groups per molecule in the acrylic polymer having hydrolyzable silyl groups is 1 The concentration of hydrolyzable silyl groups in the acrylic polymer having hydrolyzable silyl groups determined by H-NMR and the number average molecular weight of the acrylic polymer having hydrolyzable silyl groups determined by GPC method can be calculated based on the concentration of hydrolyzable silyl groups in the acrylic polymer having hydrolyzable silyl groups determined by H-NMR and the number average molecular weight of the acrylic polymer having hydrolyzable silyl groups determined by GPC method.

[0051] Examples of the main chain skeleton of an acrylic polymer having a hydrolyzable silyl group include acrylic polymers obtained by radical polymerization of (meth)acrylate monomers, where (meth)acrylate means methacrylate or acrylate.

[0052] Specific examples of the (meth)acrylate monomer that constitutes the main chain of the acrylic polymer having a hydrolyzable silyl group include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, tert-butyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, and isomy Styryl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, benzyl (meth)acrylate, 2-butoxyethyl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, hexanediol di(meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol di(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy(meth)acrylate, polyester(meth)acrylate, urethane(meth)acrylate, 2-hydroxyethyl(meth)acrylate, 3-hydroxypropyl(meth)acrylate, 2-hydroxypropyl(meth)acrylate acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 5-hydroxypentyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 3-hydroxy-3-methylbutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 2-[acryloyloxy]ethyl-2-hydroxyethyl phthalate, 2-[acryloyloxy]ethyl-2-hydroxypropyl phthalate, and the like.As the (meth)acrylate monomer, an alkyl(meth)acrylate having an alkyl group with 1 to 6 carbon atoms is preferred, an alkyl(meth)acrylate having an alkyl group with 1 to 5 carbon atoms is more preferred, and an alkyl acrylate having an alkyl group with 1 to 5 carbon atoms is even more preferred. As the (meth)acrylate monomer, methyl(meth)acrylate and butyl(meth)acrylate are preferred, butyl(meth)acrylate is more preferred, and butyl acrylate is even more preferred. These (meth)acrylate monomers may be used alone or in combination of two or more.

[0053] In the acrylic polymer having a hydrolyzable silyl group, other monomers can also be copolymerized. Examples of such monomers include styrene derivatives such as styrene, indene, α-methylstyrene, p-methylstyrene, p-chlorostyrene, p-chloromethylstyrene, p-methoxystyrene, p-tert-butoxystyrene, and divinylbenzene; compounds having a vinyl ester group such as vinyl acetate, vinyl propionate, vinyl butyrate, vinyl caproate, vinyl benzoate, and vinyl cinnamate; maleic anhydride, N-vinylpyrrolidone, N-vinylmorpholine, (meth)acrylonitrile, (meth)acrylamide, N-cyclohexylmaleimide, N-phenylmaleimide, N-laurylmaleimide, N-benzylmaleimide, n-propyl vinyl ether, n-butyl vinyl ether, isobutyl vinyl ether, tert-butyl vinyl ether, tert-amyl vinyl ether, cyclohexyl vinyl ether, 2-ethylhexyl vinyl ether, dodecyl vinyl ether, octadecyl vinyl ether, 2-chloroethyl vinyl ether, ethylene glycol butyl vinyl ether, and triethylene glycol butyl vinyl ether. Examples of vinyloxy groups include glycol methyl vinyl ether, (4-vinyloxy)butyl benzoate, ethylene glycol divinyl ether, diethylene glycol divinyl ether, triethylene glycol divinyl ether, tetraethylene glycol divinyl ether, butane-1,4-diol divinyl ether, hexane-1,6-diol divinyl ether, cyclohexane-1,4-dimethanol divinyl ether, di(4-vinyloxy)butyl isophthalate, di(4-vinyloxy)butyl glutarate, di(4-vinyloxy)butyl succinate, trimethylolpropane trivinyl ether, 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, 6-hydroxyhexyl vinyl ether, cyclohexane-1,4-dimethanol monovinyl ether, diethylene glycol monovinyl ether, 3-aminopropyl vinyl ether, 2-(N,N-diethylamino)ethyl vinyl ether, urethane vinyl ether, and polyester vinyl ether. These monomers may be used alone or in combination.

[0054] Among these, the main chain skeleton of the acrylic polymer having a hydrolyzable silyl group is preferably a copolymer of butyl (meth)acrylate and methyl (meth)acrylate, more preferably a copolymer of butyl acrylate and methyl methacrylate, and even more preferably a homopolymer of butyl acrylate. When the acrylic polymer having a hydrolyzable silyl group, whose main chain skeleton is the copolymer, is used, the sound-insulating composition can be filled or coated in accordance with the shape of the filled or coated portion, thereby imparting excellent sound insulation to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed portion is improved, and the cured product can be filled into the sealed portion without any gaps, thereby improving the sound insulation in the sealed portion.

[0055] The polymerization method for the acrylic polymer having a hydrolyzable silyl group is not particularly limited, and known methods can be used, including various polymerization methods such as free radical polymerization, anionic polymerization, cationic polymerization, UV radical polymerization, living anionic polymerization, living cationic polymerization, and living radical polymerization.

[0056] The method for introducing a hydrolyzable silyl group into an acrylic polymer having a hydrolyzable silyl group is not particularly limited, and any known method can be used, such as a method of hydrosilylating an acrylic polymer having an unsaturated group introduced into the molecule by allowing a hydrosilane having a hydrolyzable silyl group to act on the polymer.

[0057] The number average molecular weight of the acrylic polymer having a hydrolyzable silyl group is preferably at least 15000, more preferably at least 20000. When the number average molecular weight of the acrylic polymer having a hydrolyzable silyl group is at least 15000, the exudation of the plasticizer onto the surface of the cured product is reduced, and the contamination of the surface of the substrate due to migration to the surface of the substrate such as a panel or a coated object is reduced.

[0058] The number average molecular weight of the acrylic polymer having a hydrolyzable silyl group is preferably 50,000 or less, more preferably 40,000 or less, and even more preferably 30,000 or less. When the number average molecular weight of the acrylic polymer having a hydrolyzable silyl group is 50,000 or less, the sound-insulating composition can be filled or coated in accordance with the shape of the filled or coated portion, and excellent sound insulation can be imparted to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed portion is improved, and the cured product can be filled into the sealed portion without any gaps, thereby improving the sound insulation in the sealed portion.

[0059] In the present invention, the number-average molecular weight and weight-average molecular weight of the acrylic polymer having a hydrolyzable silyl group refer to values ​​measured by gel permeation chromatography (GPC) in terms of polystyrene. In the GPC measurement, for example, a Shodex KF800D manufactured by Tosoh Corporation can be used as a GPC column, and chloroform or the like can be used as a solvent.

[0060] The number average molecular weight and weight average molecular weight of the acrylic polymer having a hydrolyzable silyl group can be measured, for example, using the following measuring device and under the following measuring conditions. Measuring device: TOSOH Corporation, product name "HLC-8121GPC / HT" Measurement conditions Column: TSKgelGMHHR-H(20)HT x 3 TSKguardcolumn-HHR(30)HT x 1 Mobile phase: o-DCB 1.0mL / min Sample concentration: 1 mg / mL Detector: Bryce type refractometer Standard material: Polystyrene (TOSOH Corporation, molecular weight: 500-8420000) Elution conditions: 145℃ SEC temperature: 145℃

[0061] [Plasticizer] The sound-insulating composition contains a plasticizer. By including a plasticizer in the sound-insulating composition, the sound-insulating composition can be filled or coated according to the shape of the filled or coated portion, thereby imparting excellent sound insulation to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed portion is improved, allowing the cured product to be filled into the sealed portion without gaps, thereby improving the sound insulation of the sealed portion. Furthermore, even when a substrate such as a panel or a coated object is deformed due to changes in atmospheric conditions, the cured product can smoothly follow the deformation of the substrate while maintaining a tight adhesion, thereby maintaining excellent sound insulation. The sound-insulating composition uses a polymer having a hydrolyzable silyl group having the structure shown in Formula (1) in combination with a plasticizer, thereby reducing leaching of the plasticizer from the cured product and reducing contamination of the substrate.

[0062] The plasticizer is an additive for imparting plasticity to the cured product of the sound-insulating composition or for increasing the plasticity. Examples of the plasticizer include, but are not limited to, polyalkylene glycols such as polyethylene glycol and polypropylene glycol; trialkylene glycols such as triethylene glycol and tripropylene glycol; phthalate esters such as dibutyl phthalate, diethylhexyl phthalate, diisononyl phthalate, and diisodecyl phthalate; aliphatic dibasic acid esters including adipic acid esters such as diethylhexyl adipate, dibutyl adipate, and diisononyl adipate; citric acid esters; trimellitic acid esters; aliphatic polyesters such as butylene glycol adipate polyesters and propylene glycol adipate polyesters; phthalic acid polyesters; epoxidized soybean oil, ethylene glycol, propylene glycol adipate, and propylene glycol adipate polyesters; ethylene glycol diisodecyl phthalate ... Examples of suitable plasticizers include those having an epoxy structure such as epoxidized linseed oil and epoxidized fatty acid alkyl esters; benzoic acid esters such as 2-ethylhexyl benzoate, isodecyl benzoate, and glycol benzoate; glycol diesters; and glycol dibenzoates such as diethylene glycol dibenzoate, dipropylene glycol dibenzoate, and triethylene glycol dibenzoate. Polyalkylene glycols and trialkylene glycols are preferred, with polyethylene glycol, polypropylene glycol, triethylene glycol, and tripropylene glycol being more preferred, polypropylene glycol and triethylene glycol being more preferred, and polypropylene glycol being even more preferred. The plasticizers may be used alone or in combination of two or more.

[0063] The number of carbon atoms in the alkylene group contained in the polyalkylene glycol is preferably 2 to 5, more preferably 2 to 4, and still more preferably 2 or 3. When the number of carbon atoms in the alkylene group is within the above range, the alkylene group is more likely to be retained in the crosslinked polymer having a hydrolyzable silyl group in the cured product of the sound-insulating composition, thereby reducing exudation to the surface of the cured product and reducing migration to the surface of a substrate such as a panel or a substrate to be coated, thereby reducing contamination of the surface of the substrate.

[0064] The number of carbon atoms in the alkylene group contained in the trialkylene glycol is preferably 2 to 5, more preferably 2 to 4, and more preferably 2 or 3. When the number of carbon atoms in the alkylene group is within the above range, the alkylene group is more likely to be retained in the crosslinked polymer having a hydrolyzable silyl group in the cured product of the sound-insulating composition, thereby reducing exudation to the surface of the cured product and reducing migration to the surface of a substrate such as a panel or a substrate to be coated, thereby reducing contamination of the surface of the substrate.

[0065] When the polymer having a hydrolyzable silyl group has the structure represented by the above formula (1) and has a number-average molecular weight of 13,000 to 50,000, and the plasticizer contains a polyalkylene glycol or trialkylene glycol, the branched structure of the crosslinked polymer having a hydrolyzable silyl group and the affinity with the polyalkylene glycol or trialkylene glycol in the cured product of the sound-insulating composition effectively entangle the two, thereby reducing the exudation of the plasticizer from the cured product. Furthermore, since the branched structure of the crosslinked polymer having a hydrolyzable silyl group and the polyalkylene glycol or trialkylene glycol are moderately entangled in molecular chains, the sound wave attenuation effect caused by the vibration of the crosslinked polymer having a hydrolyzable silyl group is not inhibited, and the cured product of the sound-insulating composition has excellent sound insulation properties.

[0066] The number average molecular weight of the polyalkylene glycol is preferably 1000 or more, more preferably 2000 or more, and more preferably 2500 or more. The number average molecular weight of the polyalkylene glycol is preferably 5000 or less, more preferably 4000 or less, and more preferably 3500 or less. When the number average molecular weight of the polyalkylene glycol is within the above range, the entanglement between the branched structure of the crosslinked polymer having a hydrolyzable silyl group and the branched structure of the polyalkylene glycol is moderate, thereby further reducing the exudation of the plasticizer from the cured product and improving the sound insulation properties of the cured product of the sound-insulating composition. The number average molecular weight of the polyalkylene glycol can be measured in the same manner as for the polymer having the above formula (1) and having a hydrolyzable silyl group.

[0067] The viscosity of the plasticizer measured at 23°C at 10 rpm is preferably 20 mPa·s or more, more preferably 30 mPa·s or more, more preferably 40 mPa·s or more, more preferably 100 mPa·s or more, more preferably 200 mPa·s or more, more preferably 300 mPa·s or more, more preferably 400 mPa·s or more, more preferably 500 mPa·s or more, and more preferably 600 mPa·s or more. The viscosity of the plasticizer measured at 23°C at 10 rpm is preferably 1000 mPa·s or less, more preferably 900 mPa·s or less, and more preferably 800 mPa·s or less. When the viscosity of the plasticizer measured at 23°C at 10 rpm is 1000 mPa·s or less, the plasticizer can be filled without gaps to match the sealing portion or can be coated to match the shape of the substrate, and the cured product of the sound-insulating composition can form a component with excellent sound insulation. When the viscosity of the plasticizer measured at 23°C under the condition of 10 rpm is 20 mPa·s or more, the sound-insulating composition can be made less likely to become stringy.

[0068] The viscosity of a plasticizer measured at 23°C at 10 rpm refers to the viscosity measured using a BM type viscometer with rotor No. 4 to 27 at a temperature of 23°C, a relative humidity of 50%, and a rotation speed of 10 rpm.

[0069] The content of the plasticizer in the sound-insulating composition is 10 parts by mass or more, preferably 20 parts by mass or more, more preferably 30 parts by mass or more, more preferably 40 parts by mass or more, more preferably 50 parts by mass or more, more preferably 60 parts by mass or more, and more preferably 70 parts by mass or more, per 100 parts by mass of the polymer having a structure represented by Formula (1) and a hydrolyzable silyl group with a number-average molecular weight of 13,000 to 50,000. The content of the plasticizer in the sound-insulating composition is 120 parts by mass or less, preferably 110 parts by mass or less, and more preferably 100 parts by mass or less, per 100 parts by mass of the polymer having a structure represented by Formula (1) and a hydrolyzable silyl group with a number-average molecular weight of 13,000 to 50,000. When the content of the plasticizer is 10 parts by mass or more, the sound-insulating composition can be filled or coated in accordance with the shape of the filled or coated portion, and excellent sound insulation can be imparted to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed area is improved, allowing the cured product to fill the sealed area without any gaps, thereby improving the sound insulation of the sealed area. Furthermore, even when a substrate such as a panel or a coated object is deformed due to changes in atmospheric conditions, the cured product can smoothly follow the deformation of the substrate while maintaining a tight adhesion, thereby maintaining excellent sound insulation. When the content of the plasticizer is 120 parts by mass or less, excellent flexibility can be imparted to the crosslinked body of the polymer having a hydrolyzable silyl group, while leaching of the plasticizer from the crosslinked body can be reduced, and contamination of the substrate can be further reduced.

[0070] [Filling material] The sound-insulating composition preferably contains a filler, which improves the sound insulation properties of the cured product of the sound-insulating composition.

[0071] The filler is not particularly limited, and examples thereof include heavy calcium carbonate, magnesium carbonate, calcium oxide, hydrous silicic acid, silicic anhydride, finely powdered silica, calcium silicate, metal hydroxides such as aluminum hydroxide, metal oxides such as titanium dioxide, clay, talc, carbon black, glass balloons, etc. Among these, calcium carbonate, metal oxides, and metal hydroxides are preferred as fillers, as they can improve the specific gravity while maintaining a low viscosity of the sound-insulating composition and can impart excellent flexibility and elongation to the resulting cured product. The fillers may be used alone or in combination of two or more.

[0072] The average particle size of the filler is preferably 0.005 to 60 μm, more preferably 0.005 to 55 μm, more preferably 0.01 to 15 μm, and even more preferably 0.05 to 12 μm. When a filler having such an average particle size is used in combination with a polymer having a hydrolyzable silyl group and a structure represented by formula (1) and a number-average molecular weight of 13,000 to 50,000, the sound-insulating composition has a high specific gravity but a low viscosity. The sound-insulating composition can be filled or coated according to the shape of the filled or coated portion, thereby imparting excellent sound insulation to the desired portion. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed portion is improved, allowing the cured product to be filled into the sealed portion without gaps, thereby improving the sound insulation of the sealed portion. Furthermore, the resulting cured product also has excellent flexibility and extensibility, smoothly adapting to changes in the sealed portion and stably sealing the sealed portion, thereby stably maintaining excellent sound insulation. Furthermore, by setting the average particle size of the filler within the above range and containing a polymer having a hydrolyzable silyl group, which has the structure shown in formula (1) and has a number-average molecular weight within a predetermined range, and a plasticizer, the thixotropy of the sound-insulating composition is improved, and the sound-insulating composition is less likely to become stringy, thereby improving the handleability of the sound-insulating composition.

[0073] The average particle size of calcium carbonate is preferably 0.01 to 10 μm, more preferably 0.05 to 8 μm. When calcium carbonate having such an average particle size is used in combination with a polymer having a hydrolyzable silyl group and a structure represented by formula (1) and a number-average molecular weight of 13,000 to 50,000, the sound-insulating composition has a high specific gravity but a low viscosity. The sound-insulating composition can be filled or coated according to the shape of the filling or coating area, thereby imparting excellent sound insulation to the desired area. In particular, when the sound-insulating composition is used as a sealant, the filling ability into the sealed area is improved, allowing the cured product to be filled into the sealed area without gaps, thereby improving the sound insulation of the sealed area. Furthermore, the resulting cured product also has excellent flexibility and extensibility, smoothly adapting to changes in the sealed area and stably sealing the sealed area, thereby stably maintaining excellent sound insulation.

[0074] The average particle size of the filler is the particle size at which the cumulative distribution (cumulative curve) reaches 50% when the volume-based particle size distribution measured using a laser scattering method is expressed as cumulative distribution with the total volume being 100%.

[0075] The calcium carbonate is preferably surface-treated with a fatty acid, a fatty acid ester, etc. Ground calcium carbonate that has been surface-treated with a fatty acid, a fatty acid ester, etc. can impart excellent thixotropy to the sound-insulating composition and can reduce aggregation of calcium carbonate.

[0076] The calcium carbonate preferably contains both surface-treated and non-surface-treated calcium carbonate. When both types of calcium carbonate are contained, the thixotropy of the sound-insulating composition can be improved, and the sound-insulating properties of the cured product of the sound-insulating composition can be improved. Furthermore, the cured product produced has excellent flexibility and extensibility, and can smoothly follow changes in the sealing area, stably seal the sealing area, and stably maintain excellent sound-insulating properties.

[0077] In the sound-insulating composition, the mass ratio of the content of non-surface-treated calcium carbonate to the content of surface-treated calcium carbonate (content of non-surface-treated calcium carbonate / content of surface-treated calcium carbonate) is preferably 0.5 or more, more preferably 1 or more, more preferably 1.5 or more, and more preferably 2 or more. In the sound-insulating composition, the mass ratio of the content of non-surface-treated calcium carbonate to the content of surface-treated calcium carbonate (content of non-surface-treated calcium carbonate / content of surface-treated calcium carbonate) is preferably 12 or less, more preferably 11 or less, more preferably 10 or less, more preferably 9 or less, more preferably 8 or less, more preferably 7 or less, more preferably 6 or less, more preferably 5 or less, more preferably 4 or less, and more preferably 3 or less. When the mass ratio of the content of non-surface-treated calcium carbonate to the content of surface-treated calcium carbonate is within the above range, the thixotropy of the sound-insulating composition can be further improved, the sound insulating properties of a cured product of the sound-insulating composition can be further improved, and further, the sound-insulating composition can be made less likely to become stringy.

[0078] The filler preferably contains a metal oxide, which can further improve the sound insulation properties of the cured product of the sound-insulating composition.

[0079] The filler preferably contains non-surface-treated calcium carbonate, surface-treated calcium carbonate, and a metal oxide, because this can further improve the thixotropy of the sound-insulating composition and can further improve the sound insulation properties of a cured product of the sound-insulating composition.

[0080] In the sound-insulating composition, the mass ratio of the metal oxide content to the surface-treated calcium carbonate content (metal oxide content / surface-treated calcium carbonate content) is preferably 0.05 or more, more preferably 0.05 or more, more preferably 0.1 or more, more preferably 0.2 or more, more preferably 0.3 or more, more preferably 0.4 or more, and more preferably 0.5 or more. In the sound-insulating composition, the mass ratio of the metal oxide content to the surface-treated calcium carbonate content (metal oxide content / surface-treated calcium carbonate content) is preferably 1.2 or less, more preferably 1.1 or less, more preferably 1.0 or less, more preferably 0.9 or less, more preferably 0.8 or less, more preferably 0.7 or less, more preferably 0.6 or less, more preferably 0.5 or less, more preferably 0.4 or less, and more preferably 0.3 or less. When the mass ratio of the content of the metal oxide to the content of the surface-treated calcium carbonate is within the above range, the thixotropy of the sound-insulating composition can be further improved, the sound-insulating properties of the cured product of the sound-insulating composition can be further improved, and further, the sound-insulating composition can be made less susceptible to stringiness.

[0081] The content of the filler in the sound-insulating composition is preferably 100 parts by mass or more, more preferably 200 parts by mass or more, more preferably 300 parts by mass or more, more preferably 400 parts by mass or more, and more preferably 450 parts by mass or more, per 100 parts by mass of the polymer having a structure represented by Formula (1) and a hydrolyzable silyl group with a number-average molecular weight of 13,000 to 50,000. The content of the filler in the sound-insulating composition is preferably 700 parts by mass or less, more preferably 650 parts by mass or less, more preferably 600 parts by mass or less, more preferably 550 parts by mass or less, and more preferably 540 parts by mass or less, per 100 parts by mass of the polymer having a structure represented by Formula (1) and a hydrolyzable silyl group with a number-average molecular weight of 13,000 to 50,000. When the content of the filler in the sound-insulating composition is within the above range, the sound insulation properties of the cured product of the sound-insulating composition are improved.

[0082] The specific gravity of the filler is preferably 2 or more, and more preferably 2.3 or more. The specific gravity of the filler is preferably 6 or less, more preferably 5 or less, more preferably 4 or less, more preferably 3.5 or less, and more preferably 3 or less. When the specific gravity of the filler is 2 or more, the cured product of the sound-insulating composition has excellent sound insulation properties. When the specific gravity of the filler is 6 or less, the state in which the filler is uniformly dispersed in the sound-insulating composition can be stably maintained for a long period of time, and a cured product with uniform sound insulation properties can be produced.

[0083] [Dehydrating agent] The sound-insulating composition preferably further contains a dehydrating agent, which can reduce hardening of the sound-insulating composition due to moisture contained in the air or the like during storage.

[0084] Examples of dehydrating agents include silane compounds such as vinyltrimethoxysilane, dimethyldimethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, tetramethoxysilane, phenyltrimethoxysilane, and diphenyldimethoxysilane; and ester compounds such as methyl orthoformate, ethyl orthoformate, methyl orthoacetate, and ethyl orthoacetate. Among these, vinyltrimethoxysilane is preferred as the dehydrating agent. The dehydrating agents may be used alone or in combination of two or more.

[0085] The content of the dehydrating agent in the sound-insulating composition is preferably 0.5 to 20 parts by mass, more preferably 1 to 15 parts by mass, per 100 parts by mass of the polymer having a hydrolyzable silyl group and having the structure represented by formula (1) and a number-average molecular weight of 13,000 to 50,000. When the content of the dehydrating agent is 0.5 parts by mass or more, the storage stability of the sound-insulating composition is improved. When the content of the dehydrating agent is 20 parts by mass or less, the curability of the sound-insulating composition is improved.

[0086] [Silanol condensation catalyst] The sound-insulating composition preferably contains a silanol condensation catalyst, which is a catalyst for promoting a dehydration condensation reaction between silanol groups formed by hydrolysis of hydrolyzable silyl groups contained in a polymer having a hydrolyzable silyl group.

[0087] Examples of silanol condensation catalysts include 1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane, dibutyltin dilaurate, dibutyltin oxide, dibutyltin diacetate, dibutyltin phthalate, bis(dibutyltin laurate) oxide, dibutyltin bis(acetylacetonate), dibutyltin bis(monoester maleate), tin octoate, dibutyltin octoate, dioctyltin oxide, dibutyltin bis(triethoxysilicate), bis(dibutyltin bistriethoxysilicate) oxide, and dibutyltin oxybisethoxysilicate; and organic titanium compounds such as tetra-n-butoxy titanate and tetraisopropoxy titanate. The silanol condensation catalysts may be used alone or in combination of two or more.

[0088] Preferred silanol condensation catalysts are dibutyltin dilaurate and 1,1,3,3-tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane. Such silanol condensation catalysts make it possible to easily adjust the curing rate of the sound-insulating composition.

[0089] The content of the silanol condensation catalyst in the sound-insulating composition is preferably 1 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the polymer having a hydrolyzable silyl group and having the structure represented by formula (1) and a number-average molecular weight of 13,000 to 50,000. When the content of the silanol condensation catalyst in the sound-insulating composition is 1 part by mass or more, the curing properties of the sound-insulating composition can be improved. When the content of the silanol condensation catalyst in the sound-insulating composition is 10 parts by mass or less, the curing rate of the sound-insulating composition can be made appropriate, and further, the storage stability and handleability of the sound-insulating composition can be improved.

[0090] [Aminosilane coupling agent] The sound-insulating composition preferably contains an aminosilane coupling agent. When the sound-insulating composition contains an aminosilane coupling agent, it is possible to reduce the exudation of plasticizer to the surface in a cured product of the sound-insulating composition, thereby reducing contamination of substrates such as panels and coated objects. When the sound-insulating composition contains an aminosilane coupling agent, it is possible to improve the adhesion of the cured product to sealing portions formed between panels and to coated objects, thereby reducing the occurrence of gaps between the substrate and the cured product, and improving the sound insulation of the cured product.

[0091] Aminosilane coupling agent refers to a compound that contains a silicon atom with an alkoxy group bonded to it in one molecule and a functional group with an amino group.Aminosilane coupling agent is not particularly limited, and for example, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, etc., and N-2-(aminoethyl)-3-aminopropyltrimethoxysilane is preferred.It should be noted that aminosilane coupling agent may be used alone or in combination of two or more kinds.

[0092] The content of the aminosilane coupling agent in the sound-insulating composition is preferably 1 part by mass or more, more preferably 2 parts by mass or more, more preferably 3 parts by mass or more, and more preferably 4 parts by mass or more, per 100 parts by mass of the polymer having a structure represented by Formula (1) and a hydrolyzable silyl group with a number-average molecular weight of 13,000 to 50,000. The content of the aminosilane coupling agent in the sound-insulating composition is preferably 15 parts by mass or less, more preferably 13 parts by mass or less, more preferably 11 parts by mass or less, and more preferably 9 parts by mass or less, per 100 parts by mass of the polymer having a structure represented by Formula (1) and a hydrolyzable silyl group with a number-average molecular weight of 13,000 to 50,000. When the content of the aminosilane coupling agent is 1 part by mass or more, it is possible to reduce the exudation of the plasticizer in the cured product of the sound-insulating composition to the surface, thereby reducing contamination of the substrate by the plasticizer and improving the sound insulation of the cured product. When the content of the aminosilane coupling agent is 15 parts by mass or less, the exudation of the aminosilane coupling agent onto the surface of the cured product is reduced, and the migration of the aminosilane coupling agent to the surface of a substrate such as a panel or a coated body, which causes contamination of the surface of the substrate, is reduced.

[0093] The sound-insulating composition may contain other additives such as antioxidants, ultraviolet absorbers, pigments, dyes, anti-settling agents, and solvents. Among these, thixotropy-imparting agents, ultraviolet absorbers, and antioxidants are preferred.

[0094] Examples of solvents include alcohols (methyl alcohol, ethyl alcohol, propyl alcohol, etc.), hydrocarbons (toluene, xylene, methylnaphthalene, kerosene, cyclohexane, isoparaffin, etc.), ethers (diethyl ether, tetrahydrofuran, dioxane, etc.), ketones (acetone, methyl ethyl ketone, etc.), and amides (N,N-dimethylformamide, etc.), with alcohols being preferred because they can increase the specific gravity of the sound-insulating composition while keeping the viscosity low, and the resulting cured product has excellent flexibility and elongation. The solvents may be used alone or in combination of two or more.

[0095] Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers and benzophenone-based ultraviolet absorbers, with benzotriazole-based ultraviolet absorbers being preferred. The content of the ultraviolet absorber in the sound-insulating composition is preferably 0.1 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, per 100 parts by mass of the polymer having a hydrolyzable silyl group and having a structure represented by formula (1) and a number-average molecular weight of 13,000 to 50,000.

[0096] Examples of the antioxidant include hindered phenol-based antioxidants, monophenol-based antioxidants, bisphenol-based antioxidants, and polyphenol-based antioxidants, with hindered phenol-based antioxidants being preferred. The content of the antioxidant in the sound-insulating composition is preferably 0.1 to 20 parts by mass, more preferably 0.3 to 10 parts by mass, per 100 parts by mass of the polymer having a hydrolyzable silyl group and having a structure represented by formula (1) and a number-average molecular weight of 13,000 to 50,000.

[0097] Examples of thixotropic agents include aliphatic amide-based thixotropic agents (e.g., polyamide waxes), polyethylene oxide-based thixotropic agents, and metal soaps (calcium stearate, aluminum stearate, barium stearate, etc.), with aliphatic amide-based thixotropic agents being preferred.

[0098] The content of the thixotropy-imparting agent in the sound-insulating composition is preferably 0.5 to 10 parts by mass, and more preferably 1 to 5 parts by mass, per 100 parts by mass of the polymer having a hydrolyzable silyl group and having the structure represented by formula (1) and a number-average molecular weight of 13000 to 50000. When the content of the thixotropy-imparting agent is within the above range, the sound-insulating composition is less likely to become stringy.

[0099] [Sound-insulating composition] The sound-insulating composition can be produced by supplying the polymer having a hydrolyzable silyl group, and optionally containing a plasticizer, a filler, and other additives, to a known stirring device and mixing them.

[0100] The specific gravity of the sound-insulating composition is 1.6 or more, preferably 1.65 or more, and more preferably 1.7 or more. The specific gravity of the sound-insulating composition is preferably 10 or less, and more preferably 7 or less. When the sound-insulating composition has a specific gravity of 1.6 or more, the cured product of the sound-insulating composition has excellent sound insulation properties.

[0101] The specific gravity of the sound-insulating composition is measured as follows: A stainless steel plate with a thickness of approximately 1.5 mm is prepared, and the mass W1 (g) of the stainless steel plate is measured. The stainless steel plate is immersed in water, and the volume V0 (cm 3 ) is measured.

[0102] Next, approximately 1 g of the sound-insulating composition is applied to one surface of the stainless steel plate. The mass W1 (g) of the stainless steel plate coated with the sound-insulating composition is measured. The volume V1 (cm 3 ) is measured in the same manner as above. The specific gravity of the sound-insulating composition is calculated based on the following formula. Specific gravity of sound-insulating composition=(W1-W0) / (V1-V0)

[0103] The viscosity of the sound-insulating composition at 23°C measured at 10 rpm is preferably 700,000 mPa·s or less, more preferably 690,000 mPa·s or less, more preferably 685,000 mPa·s or less, preferably 600,000 mPa·s or less, and more preferably 550,000 mPa·s or less. The viscosity of the sound-insulating composition at 23°C measured at 10 rpm is preferably 300,000 mPa·s or more, more preferably 350,000 mPa·s or more, more preferably 380,000 mPa·s or more, more preferably 390,000 mPa·s or more, and more preferably 395,000 mPa·s or more. If the sound-insulating composition has a viscosity of 700,000 mPa·s or less at 23°C measured at 10 rpm, it can be filled without gaps to fit sealing areas or can be coated to fit the shape of the substrate, and the cured sound-insulating composition can form a component with excellent sound insulation.If the sound-insulating composition has a viscosity of 300,000 mPa·s or more at 23°C measured at 10 rpm, the sound-insulating composition can be made less likely to become stringy.

[0104] The viscosity of the sound-insulating composition measured at 23°C under conditions of 10 rpm refers to the viscosity obtained by measuring using a BS-type viscometer with a rotor No. 7 under conditions of a temperature of 23°C, a relative humidity of 50%, and a rotation speed of 10 rpm.

[0105] The sound-insulating composition has a thixotropy index of 5 or more, preferably 5.5 or more, more preferably 6.0 or more, and even more preferably 7.0 or more. There is no upper limit to the thixotropy index of the sound-insulating composition, but it is preferably 8 or less. When the sound-insulating composition has a thixotropy index of 5 or more, the viscosity of the sound-insulating composition can be reduced during use, allowing the sound-insulating composition to be filled without gaps in accordance with the sealing portion or coated to conform to the shape of the substrate, and a cured product of the sound-insulating composition can be used to form a component with excellent sound insulation properties. Furthermore, the sound-insulating composition is less likely to become stringy or sagging during application, and has excellent coatability.

[0106] The thixotropy is measured as follows: The viscosity of the sound-insulating composition is measured using a BS-type viscometer with a No. 7 rotor at a temperature of 23°C, a relative humidity of 50%, and a rotation speed of 10 rpm or 1 rpm, and the thixotropy is calculated according to the following formula: Thixotropy = Viscosity at a rotation speed of 1 rpm / Viscosity at a rotation speed of 10 rpm

[0107] The sound-insulating composition cures in the atmosphere (air) or with moisture present in the substrate to produce a cured product with excellent sound-insulating properties. The sound-insulating composition has low viscosity and excellent thixotropy, making it excellent for filling sealing portions formed between panels or for applying to desired locations. Furthermore, the cured product produced by curing the sound-insulating composition has excellent sound-insulating properties.

[0108] Therefore, the sound-insulating composition of the present invention can be easily filled without gaps into the sealing portions formed between panels, or can be applied to fit the shape of the object to be coated. Therefore, the sealing portions formed between panels are filled without gaps with a cured product with excellent sound insulation properties, making it easy to construct spaces with excellent sound insulation (e.g., soundproof rooms). Furthermore, the cured product can be produced to fit the shape of the object to be coated (the area to be coated, for example, a wall such as an exterior wall, interior wall, or ceiling), and excellent sound insulation can be imparted to the object to be coated.

[0109] Furthermore, the cured product of the sound-insulating composition has excellent flexibility and extensibility, and can smoothly conform to changes in the shape of the sealing area formed between panels or the object to be coated, thereby enabling excellent sound insulation to be stably maintained.

[0110] As described above, the sound-insulating composition has low viscosity, excellent thixotropy, and excellent handleability, and therefore can be used in various applications such as sealing materials, coating materials, adhesives, and paints, and is particularly suitable for use as a sealing material.

[0111] The cured product obtained by curing the sound-insulating composition with moisture has excellent sound insulation properties, so by filling a sealing portion formed between panels that constitute a space such as a room with the sound-insulating composition, or by applying the sound-insulating composition to a coated body and curing it, it is possible to impart excellent sound insulation to the sealing portion or the coated body, and to easily construct a structure such as a space with excellent sound insulation properties. Moreover, even if the cured product of the sound-insulating composition contains a plasticizer, the leaching of the plasticizer to the surface of the cured product is reduced, so that substrates such as panels or coated bodies are not contaminated by the plasticizer and the appearance can be maintained in a beautiful condition for a long period of time.

[0112] The cured sound-insulating composition has excellent flexibility, so it can smoothly adapt to changes in the dimensions of the sealed area or the object to be coated due to environmental changes such as temperature and humidity, maintaining good adhesion to the sealed area or the object to be coated and maintaining excellent sound-insulating properties for a long period of time.

[0113] A method for applying a sound-insulating composition to a sealing portion (gap) to obtain a sealing structure involves filling the gap with the sound-insulating composition, allowing it to cure and harden by moisture in the air or in the components that make up the sealing portion. The resulting sealing structure comprises a structural member of an architectural structure and a cured product of the sound-insulating composition that has been filled into a gap formed between adjacent structural members. Examples of structural members of an architectural structure include wall portions such as exterior walls, interior walls, and ceilings. [Example]

[0114] The present invention will be described in more detail below using examples, but the present invention is not limited thereto. Specific numerical values ​​of blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be replaced with the upper limit values ​​(numeric values ​​defined as "equal to or less than") or lower limit values ​​(numeric values ​​defined as "equal to or greater than") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the "Description of Embodiments."

[0115] The compounds shown below were used in the examples and comparative examples. [Polymers containing hydrolyzable silyl groups] Polyoxyalkylene polymer 1 having a hydrolyzable silyl group (manufactured by Kaneka Corporation, trade name "SILYL SAX260", number average molecular weight: 17,000, molecular weight distribution: 1.2, formula (1), R 1 : Propylene group [-CH(CH3)-CH2-], R 2 : Hydrogen atom, R 3 : Methyl group, k: 1, x: 90-120, y: 90-120, z: 90-120)

[0116] Polyoxyalkylene polymer 2 having a hydrolyzable silyl group (manufactured by AGC Corporation, trade name "S6250", number average molecular weight: 15,000, molecular weight distribution: 1.2, formula (1), R 1 : Propylene group [-CH(CH3)-CH2-], R 2 : Hydrogen atom, R 3 : methyl group, k: 1, x: 80-110, y: 80-110, z: 80-110)

[0117] Polyoxyalkylene polymer 3 having hydrolyzable silyl groups (manufactured by Kaneka Corporation, trade name "SILYL SAX350", number average molecular weight: 17,000, main chain: polyoxyethylene, having hydrolyzable silyl groups (dimethoxysilyl groups) at both ends of the linear main chain)

[0118] Polyoxyalkylene polymer 4 having a hydrolyzable silyl group (manufactured by Kaneka Corporation, trade name "SILYL SAX015", number average molecular weight: 4700, molecular weight distribution: 1.2, formula (1), R 1 : Propylene group [-CH(CH3)-CH2-], R 2 : hydrogen atom, x: 15-35, y: 15-35, z: 15-35)

[0119] [ka]

[0120] [Plasticizer] Polypropylene glycol (PPG, number average molecular weight: 3000, viscosity measured at 23°C under 10 rpm conditions: 700 mPa·s) Diisononyl phthalate (DINP, viscosity measured at 23°C under 10 rpm: 175 mPa·s) Triethylene glycol (viscosity measured at 23°C under 10 rpm conditions: 75 mPa·s)

[0121] [Filling material] Untreated heavy calcium carbonate (specific gravity: 2.7, average particle size: 5.5 μm) Surface-treated heavy calcium carbonate (specific gravity: 2.7, average particle size: 0.05 μm, surface treatment: fatty acid treatment) Titanium dioxide (specific gravity: 4.0, average particle size: 0.2 μm) Aluminum hydroxide (specific gravity: 2.7, average particle size: 54 μm)

[0122] [solvent] Ethyl alcohol Isoparaffin [Dehydrating agent] Vinyltrimethoxysilane [Aminosilane coupling agent] N-2-(aminoethyl)-3-aminopropyltrimethoxysilane [Silanol condensation catalyst] 1,1,3,3-Tetrabutyl-1,3-dilauryloxycarbonyl-distannoxane [Thixotropic agent] Aliphatic amide thixotropic agent (manufactured by Ito Oil Mills, product name "T-1800")

[0123] (Examples 1 to 9, Comparative Examples 1 to 4) A sound-insulating composition was obtained by mixing a polymer having a hydrolyzable silyl group, a plasticizer, a filler, a solvent, a dehydrating agent, an aminosilane coupling agent, and a silanol condensation catalyst in the amounts shown in Table 1 in a sealed mixer under reduced pressure until uniform.

[0124] The specific gravity, viscosity at 23°C measured at 10 rpm, and thixotropy of the obtained sound-insulating composition were measured in the same manner as above, and the results are shown in Table 1. In Table 1, "viscosity at 23°C measured at 10 rpm" is referred to as "viscosity."

[0125] The resulting sound-insulating compositions were measured for stain resistance, hardness, elongation and stringiness in the following manner. The results are shown in Table 1.

[0126] (pollution) A gypsum board conforming to JIS A6901 was prepared. The sound-insulating composition was applied to a board base paper attached to the surface of the gypsum board in a width of 1 cm using a hand gun. The sound-insulating composition was cured by aging for 24 hours in an atmosphere of 23°C and 50% relative humidity. After the sound-insulating composition cured, the width of the plasticizer seeping into the board base paper (the maximum width of the plasticizer seeping from the cured sound-insulating composition) was measured and evaluated according to the following criteria.

[0127] A: The width of the leak was less than 1 mm. B: The width of the leak was 1 mm or more and less than 2 mm. C: The width of the leak was 2 mm or more.

[0128] [Elongation (gauge length) and hardness] The sound-insulating composition was applied to a polyethylene sheet to a thickness of 300 μm, and cured by aging for 168 hours in an atmosphere of 23°C and a relative humidity of 50% to prepare a test specimen. The obtained test specimen was subjected to a tensile property test in accordance with JIS A1439 to measure the elongation (gauge length) (cm).

[0129] Two test pieces were prepared in the same manner as above, and the two test pieces were stacked together to prepare a laminated sheet. The hardness of the obtained laminated sheet was measured using Type A in accordance with JIS K6253-3.

[0130] (string resistance) In an atmosphere maintained at 23°C, 50 mL of the uncured liquid sound-insulating composition was poured into a container to a depth of 3 cm. A circular rod (bamboo stick) with a cross section of approximately 0.5 mm in diameter was immersed in the sound-insulating composition, with a portion of 1 cm from its bottom end perpendicular to the surface of the sound-insulating composition. The rod was then pulled out of the sound-insulating composition in a direction perpendicular to the surface at a speed of 30 mm / sec. The sound-insulating composition (thread-like sound-insulating composition) that was connected in a thread-like manner to the bottom end of the rod and the sound-insulating composition was pulled out until it broke. The maximum length of the thread-like sound-insulating composition was measured.

[0131] [Table 1]

Claims

1. A sound-insulating composition comprising: 100 parts by mass of a polymer having a hydrolyzable silyl group, which has a structure represented by formula (1) and a number-average molecular weight of 13,000 to 50,000; and 10 to 120 parts by mass of a plasticizer; wherein the sound-insulating composition has a specific gravity of 1.6 or more, a viscosity of 700,000 mPa s or less at 23°C measured at 10 rpm, and a thixotropy index of 5 or more. 【Chemistry 1】 However, in formula (1), R １ represents an alkylene group having 1 to 14 carbon atoms, and x, y, and z are each the number of repeating units and are positive integers. 2 represents an alkyl group having 1 to 20 carbon atoms which may have a substituent, or a hydrogen atom. 3 represents an alkyl group having 1 to 6 carbon atoms. k represents an integer of 0 to 2. 1 , R 2 and R 3 may be the same or different from each other. When there are multiple k's, they may be the same or different from each other.

2. 2. The sound-insulating composition according to claim 1, further comprising a filler.

3. 3. The sound-insulating composition according to claim 2, wherein the specific gravity of the filler is 2 to 6.

4. 4. The sound-insulating composition according to claim 2, wherein the filler contains a surface-treated filler.

5. 5. The sound-insulating composition according to claim 4, wherein the filler contains surface-treated calcium carbonate.

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