JP7179279B2 - Curable composition - Google Patents

Description

The present invention relates to curable compositions.

The modified silicone-based curable composition containing a polyoxyalkylene-based polymer having a crosslinkable silyl group is safe in that it does not generate toxic substances during curing, and the cured product obtained by curing has elasticity and durability. It is widely used as a sealant and adhesive due to its excellent

Urethane solvent-based adhesives and water-based adhesives have been conventionally used for laying and integrating floor finishing materials on underfloor materials in indoor corridors such as condominiums and hospitals.

A urethane solvent-based adhesive contains a solvent, so it is not preferable in terms of environmental hygiene. Water-based adhesives have a problem of poor water resistance. Therefore, replacement with modified silicone adhesives is in progress.

Further, when the floor finishing material is laid and integrated on the underfloor material, the adhesive is usually applied onto the underfloor material using a pectinate trowel. Since the coating of the adhesive on the underfloor material covers a large area and is performed manually, the adhesive is required to have low viscosity and coatability that allows it to be spread with a small force.

However, modified silicone-based adhesives have the problem that they have higher viscosity and are inferior in coatability compared to conventionally used solvent-based adhesives such as urethane solvent-based adhesives and water-based adhesives. there is

Therefore, it has been proposed to improve coatability by imparting thixotropic properties to modified silicone adhesives. Specifically, addition of organic thixotropic agents such as amide wax and hydrogenated castor oil (Patent Document 1) and use of precipitated calcium carbonate (Patent Document 2) have been proposed.

However, according to the methods of Patent Documents 1 and 2, the viscosity of the adhesive becomes high, the adhesive does not flow between the underfloor material and the floor finishing material, and the floor finishing material partially adheres to the adhesive. is supported by

Many floor finishing materials are thin, so when the floor finishing material is partially supported by the adhesive, the floor finishing material is easily deformed, resulting in irregularities on the installed floor surface. This causes a problem that the appearance is spoiled.

Therefore, in order to reduce the viscosity of the modified silicone-based adhesive, Patent Document 3 proposes to reduce the viscosity of the modified silicone-based adhesive by using heavy calcium carbonate.

However, the method of Patent Document 3 causes a problem that the cured product of the modified silicone adhesive becomes hard and brittle, and sufficient adhesive strength cannot be obtained.

As described above, the adhesive is applied onto the underfloor material using a pectinate trowel. The adhesive applied to the underfloor material has a comb-like shape in which the cross section has a chevron shape and the adjacent adhesives are continuous with a slight gap, Peaks and valleys alternately exist.

When the floor finishing material is laid on the underfloor material, the air existing between the underfloor material and the floor finishing material is released through the valleys, and the adhesive is spread between the floor finishing material and the underfloor material. It can be spread out and familiarized with it.

Furthermore, by spreading the adhesive toward the valleys, the adhesive present between the floor covering material and the subfloor material is prevented from protruding from the edge of the floor covering material, so that the floor covering material adheres to the adhesive. can be prevented from being contaminated by

Further, when the viscosity of the modified silicone adhesive is lowered, the thixotropy of the modified silicone adhesive is lowered, and as a result, the modified silicone adhesive applied to the underfloor material has a comb-like shape. Therefore, another problem arises in that the above-described effect of the adhesive and the effect of preventing contamination of the floor finishing material by the adhesive cannot be realized.

Therefore, in order to make modified silicone-based adhesives low in viscosity and high in thixotropic properties, organic solvents are added. In terms of environmental hygiene, it causes a problem that it is not preferable.

JP 2002-265914 A JP 2015-086354 A JP 2009-242506 A

The present invention does not emit a solvent odor like a solvent-based adhesive, is excellent in environmental hygiene during use, has low viscosity and high thixotropy (high thixotropy), and has coatability and A curable composition having excellent adhesive strength is provided.

The curable composition of the present invention is
A polyoxyalkylene polymer (A) having a crosslinkable silyl group;
Precipitated calcium carbonate and surface-untreated ground calcium carbonate are included, and the content ratio of the precipitated calcium carbonate and the surface-untreated ground calcium carbonate (content of precipitated calcium carbonate / surface-untreated surface Calcium carbonate (B) having a heavy calcium carbonate content) of 0.1 to 1.0;
containing a silane coupling agent (C),
It has a viscosity of 15,000 to 100,000 mPa·s at 23° C., and a ratio of viscosity at 1 rpm to viscosity at 10 rpm (viscosity at 1 rpm/viscosity at 10 rpm) is 5 to 10. .

[Polyoxyalkylene polymer (A)]
The curable composition contains a polyoxyalkylene polymer (A) having a crosslinkable silyl group.

The polyoxyalkylene polymer (A) having a crosslinkable silyl group has a main chain of the general formula: -(RO) _n - (wherein R represents an alkylene group having 1 to 14 carbon atoms, n is the number of repeating units and is a positive integer. The main chain skeleton of the polyoxyalkylene polymer (A) may consist of one type of repeating unit, or may consist of two or more types of repeating units. The polyoxyalkylene polymer (A) having a crosslinkable silyl group may be simply referred to as "polyoxyalkylene polymer (A)".

The main chain skeleton of the polyoxyalkylene polymer (A) includes polyoxyethylene, polyoxypropylene, polyoxybutylene, polyoxytetramethylene, polyoxyethylene-polyoxypropylene copolymer, and polyoxypropylene-poly Examples include oxybutylene copolymers, and polyoxypropylene is preferred.

The crosslinkable silyl group, for example, a silicon-containing group having a hydrolyzable group bonded to a silicon atom or a silanol group, can be condensed in the presence of moisture or a crosslinker, if necessary using a catalyst or the like. A group that undergoes a reaction.

Examples of crosslinkable silyl groups include monoalkoxysilyl groups such as a methoxysilyl group, ethoxysilyl group, dimethylmethoxysilyl group and dimethylethoxysilyl group; Examples thereof include trialkoxysilyl groups such as alkoxysilyl groups, trimethoxysilyl groups and triethoxysilyl groups, and halogen-bonded silyl groups such as trichlorosilyl groups. Dialkoxysilyl groups are preferred, and dimethoxysilyl groups are preferred.

The polyoxyalkylene polymer (A) preferably does not contain urethane bonds. Since the polyoxyalkylene polymer (A) does not have a urethane bond, it is possible to suppress an increase in the viscosity of the resulting curable composition at low temperatures such as in winter, thereby improving coatability. .

The polyoxyalkylene polymer (A) having a crosslinkable silyl group at both ends of the polyoxyalkylene chain without intervening urethane bonds is, for example, a polyoxyalkylene polymer having a functional group such as a hydroxyl group at the end. The coalescence is reacted with an organic compound having an active group and an unsaturated group that are reactive with this functional group, and then hydrosilylated by reacting the resulting reaction product with a hydrosilane having a hydrolyzable group. It can be manufactured by

The number average molecular weight of the polyoxyalkylene polymer (A) having a crosslinkable silyl group is preferably 18,000 or less, more preferably 8,000 to 17,000, and particularly preferably 10,000 to 15,000. The polyoxyalkylene polymer (A) having a crosslinkable silyl group may be used alone or in combination of two or more. When two or more polyoxyalkylene polymers (A) having a crosslinkable silyl group are used in combination, the number average molecular weight of the polyoxyalkylene polymer (A) having a crosslinkable silyl group is the crosslinkable silyl It refers to the number average molecular weight of the entire polyoxyalkylene polymer (A) having groups.

When the number average molecular weight of the polyoxyalkylene polymer (A) is 18000 or less, the viscosity of the curable composition is low, and the curable composition has excellent coatability regardless of the ambient environment, Even a thin floor finishing material can be beautifully laid on an underfloor material without deforming the floor finishing material. When the number average molecular weight of the polyoxyalkylene polymer (A) is 8000 or more, the strength of the cured product of the curable composition is improved, and the cured product of the curable composition has high adhesive strength.

The molecular weight distribution [weight average molecular weight (Mw)/number average molecular weight (Mn)] of the polyoxyalkylene polymer (A) is preferably 1.6 or less, more preferably 1.5 or less, and particularly 1.3 or less. preferable. According to the polyoxyalkylene polymer (A) having a molecular weight distribution of 1.6 or less, the viscosity of the curable composition is low, and the curable composition has excellent coatability regardless of the ambient environment. At the same time, even a thin floor finishing material can be beautifully laid on the underfloor material without deforming the floor finishing material. Furthermore, the adhesive strength of the cured product of the curable composition is improved.

In the present invention, the number-average molecular weight and weight-average molecular weight of the polyoxyalkylene polymer (A) having a crosslinkable silyl group are values measured by GPC (gel permeation chromatography) and converted to polystyrene. . Specifically, 6 to 7 mg of a polyoxyalkylene polymer is collected, the collected polyoxyalkylene polymer is supplied to a test tube, and 0.05% by mass of BHT (dibutylhydroxytoluene) is added to the test tube. A diluted solution is prepared by adding an o-DCB (ortho-dichlorobenzene) solution containing and diluting the concentration of the polyoxyalkylene polymer to 1 mg/mL.

Using a dissolution filtration device, the above diluted solution is shaken at 145° C. and a rotational speed of 25 rpm for 1 hour to dissolve the polyoxyalkylene polymer in the o-DCB solution containing BHT to obtain a measurement sample. . Using this measurement sample, the number average molecular weight and weight average molecular weight of the polyoxyalkylene polymer can be measured by the GPC method.

The number-average molecular weight and weight-average molecular weight of the polyoxyalkylene-based polymer can be measured, for example, using the following measurement apparatus and measurement conditions.
Measuring device manufactured by TOSOH, trade name “HLC-8121GPC/HT”
Measurement conditions Column: TSKgelGMHHR-H(20)HT x 3
TSKguardcolumn-HHR(30)HT x 1
Mobile phase: o-DCB 1.0 mL/min
Sample concentration: 1 mg/mL
Detector: Bryce refractometer
Standard material: polystyrene (manufactured by TOSOH, molecular weight: 500-8420000)
Elution conditions: 145°C
SEC temperature: 145°C

A commercially available polyoxyalkylene polymer (A) containing a crosslinkable silyl group can be used. As the polyoxyalkylene-based polymer (A), any polyoxyalkylene-based polymer (A) containing a crosslinkable silyl group can be used without particular limitation. It is a liquid substance before curing and forms good rubber elasticity after curing. It is preferable to use a polyoxypropylene-based polymer having no bonds. As a polyoxypropylene-based polymer whose main chain skeleton is polyoxypropylene, which has a dimethoxysilyl group as a hydrolyzable silyl group at the end of the main chain skeleton and does not have a urethane bond, Kaneka Corporation products The name "Silyl EST280", the product names "Excester 6250" and "Excester 4530" manufactured by Asahi Glass Co., Ltd., and the like can be mentioned.

[Calcium carbonate (B)]
The curable composition contains calcium carbonate (B). Calcium carbonate (B) contains precipitated calcium carbonate and surface-untreated ground calcium carbonate.

The curable composition contains the above-described polyoxyalkylene polymer (A) having a crosslinkable silyl group, precipitated calcium carbonate (B1), and surface-untreated ground calcium carbonate (B2). Because of this, both low viscosity and high thixotropy are achieved. Furthermore, the cured product of the curable composition has moderate mechanical strength and moderate rubber elasticity and extensibility. Therefore, not only ordinary floor finishing materials but also thin floor finishing materials can be firmly laid on the construction surface (underfloor material) without causing gaps after laying the floor finishing materials. can be made

The surface of the precipitated calcium carbonate (B1) is preferably treated with a fatty acid, fatty acid ester or fatty acid metal salt, more preferably with a fatty acid. The surface-treated precipitated calcium carbonate (B1) can impart high thixotropy to the curable composition, and the curable composition can maintain the comb-like morphology well after coating. , it is possible to prevent the aggregation of calcium carbonate.

Examples of fatty acids include caproic acid, caprylic acid, pelargonic acid, capric acid, undecanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, alaic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, and melisic acid. , obssylic acid, carroleic acid, undecylenic acid, lindelic acid, thuzunic acid, fizeteric acid, moristoleic acid, palmitoleic acid, petroselinic acid, oleic acid, elaidic acid, asclebic acid, vaccenic acid, gadoleic acid, gondoic acid, Cetreic acid, erucic acid, brassic acid, cerakoleic acid, ximenic acid, lumecitric acid, sorbic acid, linoleic acid, etc., preferably lauric acid, myristic acid, palmitic acid, stearic acid, and oleic acid.

Examples of fatty acid esters include stearyl stearate, lauryl stearate, stearyl palmitate, and lauryl palmitate.

Examples of fatty acid metal salts include sodium salts and potassium salts of the above fatty acids, and sodium lauric acid, sodium myristic acid, sodium palmitic acid, sodium stearic acid, and sodium oleic acid. preferable.

The average particle size of primary particles of precipitated calcium carbonate is preferably 5 μm or less, more preferably 0.01 to 3 μm. When the average particle size is 5 μm or less, the curable composition has high thixotropy and excellent coatability.

The average particle size of the primary particles of precipitated calcium carbonate is a value calculated based on the following formula using the specific surface area per 1 g of precipitated calcium carbonate. The specific surface area value per 1 g of precipitated calcium carbonate can be obtained by using, for example, a powder specific surface area measuring device commercially available from Shimadzu Corporation under the trade name "SS-100 type".
Average particle size (μm) of primary particles of precipitated calcium carbonate
= 6 x 10000/(specific gravity x specific surface area)

The content of the precipitated calcium carbonate (B1) in the curable composition is preferably 10 to 100 parts by mass, preferably 20 to 80 parts by mass, relative to 100 parts by mass of the polyoxyalkylene polymer (A) having a crosslinkable silyl group. Parts by weight are more preferred, and 40 to 60 parts by weight are particularly preferred. When the content of the precipitated calcium carbonate (B1) is 10 parts by mass or more, the curable composition has high thixotropy, and the curable composition after coating can maintain a pectinate shape. . Therefore, for example, the curable composition can be spread between the floor finishing material and the underfloor material to spread and fit in, and the curable composition can be prevented from protruding from the edge of the floor finishing material, and the floor finishing can be improved. It is possible to prevent the material from being contaminated by the curable composition. When the content of the precipitated calcium carbonate (B1) is 100 parts by mass or less, the viscosity of the curable composition is lowered and the coatability of the curable composition is improved.

The surface-untreated ground calcium carbonate (B2) can be obtained, for example, by pulverizing natural calcium carbonate such as natural chalk (chalk), marble and limestone into fine powder.

The average particle size of the primary particles in the surface-untreated heavy calcium carbonate is preferably 10 μm or less, more preferably 1 to 6 μm. When the average particle size is 10 µm or less, the strength of the cured product of the curable composition is improved, and the cured product of the curable composition has high adhesive strength.

The average particle size of the primary particles in surface-untreated ground calcium carbonate refers to a value calculated based on the following formula using the specific surface area per 1 g of surface-untreated ground calcium carbonate. The specific surface area value per 1 g of ground calcium carbonate can be obtained by using, for example, a powder specific surface area measuring device commercially available from Shimadzu Corporation under the trade name "SS-100 type".
Average particle size (μm) of primary particles in surface-untreated ground calcium carbonate
= 6 x 10000/(specific gravity x specific surface area)

The content of the surface-untreated heavy calcium carbonate (B2) in the curable composition is 30 to 400 parts by mass with respect to 100 parts by mass of the polyoxyalkylene polymer (A) having a crosslinkable silyl group. is preferred, 50 to 300 parts by weight is more preferred, 100 to 250 parts by weight is more preferred, and 120 to 230 parts by weight is particularly preferred. When the content of the heavy calcium carbonate (B2) is 30 parts by mass or more, the adhesive strength and water-resistant adhesiveness of the cured product of the curable composition are improved. When the content of the heavy calcium carbonate (B2) is 400 parts by mass or less, the curable composition has high thixotropy, and the curable composition after coating can maintain a pectinate shape. . Therefore, for example, the curable composition can be spread between the floor finishing material and the underfloor material to spread and fit in, and the curable composition can be prevented from protruding from the edge of the floor finishing material, and the floor finishing can be improved. It is possible to prevent the material from being contaminated by the curable composition.

In the curable composition, the content ratio of precipitated calcium carbonate (B1) and surface-untreated heavy calcium carbonate (B2) [content of precipitated calcium carbonate (B1)/surface-untreated heavy content of calcium carbonate (B2)] is 0.1 to 1.0, preferably 0.15 to 0.8, more preferably 0.18 to 0.5, and 0.2 to 0.4. More preferably, 0.22 to 0.3 is particularly preferable. When the content ratio of the precipitated calcium carbonate (B1) and the surface-untreated ground calcium carbonate (B2) is 0.1 or more, the curable composition has high thixotropic properties and hardens after coating. The composition can maintain a pectinate morphology. Therefore, for example, the curable composition can be spread between the floor finishing material and the underfloor material to spread and fit in, and the curable composition can be prevented from protruding from the edge of the floor finishing material, and the floor finishing can be improved. It is possible to prevent the material from being contaminated by the curable composition. When the content ratio of the precipitated calcium carbonate (B1) and the surface-untreated ground calcium carbonate (B2) is 1.0 or less, the viscosity of the curable composition becomes low, and the coating of the curable composition improve sexuality.

[Silane coupling agent (C)]
The curable composition contains a silane coupling agent (C). Since the curable composition contains the silane coupling agent (C), even if the curable composition has a low viscosity, the cured product of the curable composition has excellent adhesive strength.

The silane coupling agent (C) contains an amino group-containing silane coupling agent (C1) or an epoxy group-containing silane coupling agent (C2) because it improves the adhesive strength of the cured product of the curable composition. is preferred.

The silane coupling agent (C) more preferably contains an amino group-containing silane coupling agent (C1) and an epoxy group-containing silane coupling agent (C2). When the silane coupling agent (C) contains an amino group-containing silane coupling agent (C1) and an epoxy group-containing silane coupling agent (C2), the adhesive strength of the cured product of the curable composition is improved. Together with this, the water-resistant adhesion of the curable composition is improved.

The amino group-containing silane coupling agent (C1) means a compound containing a silicon atom bound with an alkoxy group in one molecule and a functional group containing a nitrogen atom. The amino group-containing silane coupling agent (C1) is not particularly limited, and examples thereof include 3-aminopropyltrimethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltriethoxysilane, N-(2-amino ethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, N,N'-bis-[3-(trimethoxysilyl)propyl]ethylenediamine, N,N '-bis-[3-(triethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(methyldimethoxysilyl)propyl]ethylenediamine, N,N'-bis-[3-(trimethoxysilyl) propyl]hexamethylenediamine, N,N'-bis-[3-(triethoxysilyl)propyl]hexamethylenediamine and the like, with N-(2-aminoethyl)-3-aminopropyltrimethoxysilane being preferred.

The epoxy group-containing silane coupling agent (C2) means a compound containing a silicon atom bound with an alkoxy group in one molecule and a functional group containing an epoxy group. The epoxy group-containing silane coupling agent is not particularly limited, and examples thereof include 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, Examples include sidoxypropylethyldiethoxysilane and 2-(3,4 epoxycyclohexyl)ethyltrimethoxysilane, with 3-glycidoxypropyltriethoxysilane being preferred.

The content of the silane coupling agent (C) in the curable composition is preferably 0.1 to 10 parts by mass, more preferably 2 to 8 parts by mass, with respect to 100 parts by mass of the polyoxyalkylene polymer (A). 3 to 6 parts by mass is particularly preferred. When the content of the silane coupling agent (C) is 0.1 parts by mass or more, the adhesive strength of the cured product of the curable composition is improved. When the content of the silane coupling agent (C) is 10 parts by mass or less, it is possible to prevent the cured product of the curable composition from becoming brittle, and to impart excellent adhesive strength and water-resistant adhesiveness to the cured product. In addition, the storage stability of the curable composition can be improved.

When the amino group-containing silane coupling agent (C1) is contained in the curable composition, the content of the amino group-containing silane coupling agent (C1) in the curable composition has a crosslinkable silyl group It is preferably 0.5 to 20 parts by mass, more preferably 1 to 10 parts by mass, particularly preferably 2 to 6 parts by mass, based on 100 parts by mass of the polyoxyalkylene polymer (A). When the content of the amino group-containing silane coupling agent (C1) is 0.5 parts by mass or more, the adhesive strength of the cured product of the curable composition is improved. When the content of the amino group-containing silane coupling agent (C1) is 20 parts by mass or less, the curable composition has excellent curability.

When the curable composition contains the epoxy group-containing silane coupling agent (C2), the content of the epoxy group-containing silane coupling agent (C2) in the curable composition is 0.3 to 20 mass. parts are preferred, 0.4 to 10 parts by weight are more preferred, 0.45 to 6 parts by weight are more preferred, and 0.5 to 3 parts by weight are particularly preferred. When the content of the epoxy group-containing silane coupling agent (C2) is 0.5 parts by mass or more, the water-resistant adhesion of the cured product of the curable composition is improved. When the content of the epoxy group-containing silane coupling agent (C2) is 20 parts by mass or less, the adhesive strength of the cured product of the curable composition is improved.

When the silane coupling agent (C) contains an amino group-containing silane coupling agent (C1) and an epoxy group-containing silane coupling agent (C2), the content of the amino group-containing silane coupling agent (C1) and the epoxy group-containing silane coupling agent (C2) content ratio (C1/C2) is preferably 1.3 to 10, more preferably 1.5 to 9, and particularly preferably 2 to 8. When the ratio of the content of the amino group-containing silane coupling agent (C1) to the content of the epoxy group-containing silane coupling agent (C2) is 1.3 or more, the storage stability of the curable composition is improved. When the ratio of the content of the amino group-containing silane coupling agent (C1) to the content of the epoxy group-containing silane coupling agent (C2) is 10 or less, the cured product of the curable composition has excellent adhesive strength. .

[Plasticizer]
The curable composition preferably contains a plasticizer. The plasticizer is not particularly limited, and examples thereof include phthalates such as dibutyl phthalate, di(2-ethylhexyl) phthalate, diisononyl phthalate, diisodecyl phthalate, and butylbenzyl phthalate; dioctyl adipate, dioctyl sebacate, dibutyl sebacate, Non-aromatic dibasic acid esters such as isodecyl succinate; aliphatic esters such as butyl oleate and methyl acetylricinoleate; polyalkylene glycol esters such as diethylene glycol dibenzoate, triethylene glycol dibenzoate and pentaerythritol ester Phosphate esters such as tricresyl phosphate and tributyl phosphate; Trimellitate esters; Polybutadiene, polybutene, polyisobutylene, butadiene-acrylonitrile, polychloroprene; Chlorinated paraffins; Hydrocarbon oils; process oils; polyether polyols such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; Epoxy plasticizers such as soybean oil and benzyl epoxy stearate; Dibasic acids such as sebacic acid, adipic acid, azelaic acid and phthalic acid and dibasic acids such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and dipropylene glycol Examples include polyester plasticizers obtained from polyhydric alcohols; and vinyl polymers obtained by polymerizing vinyl monomers such as acrylic plasticizers by various methods. The plasticizers may be used alone or in combination of two or more.

The content of the plasticizer in the curable composition is preferably 20 to 100 parts by mass, more preferably 25 to 50 parts by mass, relative to 100 parts by mass of the polyoxyalkylene polymer (A) having a crosslinkable silyl group. . When the content of the plasticizer is 20 parts by mass or more, the coatability of the curable composition is improved. When the content of the plasticizer is 100 parts by mass or less, the mechanical strength of the cured product of the curable composition is improved.

[Silanol condensation catalyst]
Preferably, the curable composition contains a silanol condensation catalyst. A silanol condensation catalyst is a catalyst for promoting dehydration condensation reaction between silanol groups formed by hydrolysis of hydrolyzable silyl groups contained in polyoxyalkylene polymers having hydrolyzable silyl groups. is. The silanol group means a hydroxy group (≡Si—OH) directly bonded to a silicon atom.

The silanol condensation catalyst is not particularly limited. acetonate), dibutyltin bis(monoester maleate), tin octylate, dibutyltin octoate, dioctyltin oxide, dibutyltin bis(triethoxysilicate), dioctyltin bis(triethoxysilicate), dioctyltin dilaurate, bis( Organotin compounds such as dibutyltin bistriethoxysilicate) oxide and dibutyltinoxybisethoxysilicate; Organotitanium compounds such as tetra-n-butoxy titanate and tetraisopropoxy titanate; 1,5,7-triazabicyclo [4.4.0]deca-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0]deca-5-ene, 1,8-diazabicyclo[5.4.0]undeca -7-ene, 6-dibutylamino-1,8-diazabicyclo[5.4.0]undec-7-ene, 1,5-diazabicyclo[4.3.0]nona-5-ene and other cycloamidine compounds ; and dibutylamine-2-ethylhexoate. Other acidic catalysts and basic catalysts can also be used as silanol condensation catalysts. The silanol condensation catalyst may be used alone or in combination of two or more.

As a silanol condensation catalyst, not only ordinary floor finishing materials, but also thin floor finishing materials can be used without causing gaps after laying floor finishing materials (subfloor materials). Organotin-based compounds are preferred because they can be laid and integrated on top.

The content of the silanol condensation catalyst in the curable composition is preferably 0.1 to 10 parts by weight, preferably 0.5 to 6 parts by weight with respect to 100 parts by weight of the polyoxyalkylene polymer (A) having a crosslinkable silyl group. Parts by mass are more preferred. When the content of the silanol condensation catalyst is 0.1 parts by mass or more, the curability of the curable composition is improved. When the content of the silanol condensation catalyst is 10 parts by mass or less, the adhesive strength of the cured product of the curable composition is improved.

[Dehydrating agent]
The curable composition preferably contains a dehydrating agent. The dehydrating agent can suppress curing of the curable composition due to moisture contained in the air or the like during storage of the curable composition.

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

The content of the dehydrating agent in the curable composition is preferably 0.5 to 20 parts by mass, preferably 1 to 15 parts by mass, relative to 100 parts by mass of the polyoxyalkylene polymer (A) having a hydrolyzable silyl group. is more preferred, and 1 to 5 parts by mass is particularly preferred. When the content of the dehydrating agent is 0.5 parts by mass or more, the storage stability of the curable composition is improved. When the content of the dehydrating agent is 20 parts by mass or less, the storage stability and handleability of the curable composition are improved.

[Other additives]
The curable composition may contain other additives such as antioxidants, UV absorbers, light stabilizers, pigments, dyes, anti-settling agents and the like. Among them, antioxidants are preferred. Preferably, the curable composition does not contain solvents.

Examples of antioxidants include hindered phenol antioxidants, monophenol antioxidants, bisphenol antioxidants, and polyphenol antioxidants, with hindered phenol antioxidants being preferred. The content of the antioxidant in the curable composition is preferably 0.1 to 20 parts by mass with respect to 100 parts by mass of the polyoxyalkylene polymer (A) having a hydrolyzable silyl group, and 0.3 to 10 parts by mass is more preferable.

The viscosity of the curable composition at 23° C. is 15,000 to 100,000 mPa·s, more preferably 20,000 to 80,000 mPa·s. In addition, the viscosity of the curable composition at 23° C. refers to a value measured at 23° C. and a rotation speed of 10 rpm using a Brookfield viscometer according to JIS K6833.

For the curable composition, the ratio of the viscosity at 10 rpm at 23° C. to the viscosity at 1 rpm at 23° C. (viscosity at 1 rpm/viscosity at 10 rpm) is 5 to 10, and 5.5 to 9. Preferably, 6 to 8 are more preferable. When the ratio of the viscosity at 10 rpm at 23° C. and the viscosity at 1 rpm at 23° C. is within the above range, the curable composition has low viscosity and high thixotropy. Therefore, for example, the curable composition can be spread between the floor finishing material and the underfloor material to spread and fit in, and the curable composition can be prevented from protruding from the edge of the floor finishing material, and the floor finishing can be improved. It is possible to prevent the material from being contaminated by the curable composition. Furthermore, the curable composition has excellent coatability.

The viscosities at 10 rpm and 1 rpm at 23° C. of the curable composition refer to values measured according to JIS K6833 using a Brookfield viscometer at 23° C. and a rotation speed of 10 rpm or 1 rpm.

The curable composition is produced by mixing a polyoxyalkylene polymer (A) having a crosslinkable silyl group, calcium carbonate (B) and a silane coupling agent (C), and optionally other additives. can do. In addition, it is preferable to perform mixing under reduced pressure.

Curable compositions are used, for example, in the construction of flooring structures. A floor structure is constructed, for example, by bonding and integrating a floor finishing material onto an underfloor material laid on a floor base via a cured product layer obtained by curing a curable composition. The floor structure comprises a floor base, an underfloor material laid on the floor base, and a curable composition formed on the underfloor material and bonded and integrated with the underfloor material by curing. and a floor covering laid on the cured layer and integrally bonded with the cured layer.

Examples of members constituting floor finishing materials include wood materials such as plywood and medium density fiberboard (MDF), tiles, vinyl chloride sheets, and stone materials. It is preferable to use a thin and soft material like a sheet.

Examples of members constituting the underfloor material include plywood, particle board, wooden joists, gypsum board, slate board, and concrete board.

The curable composition has a low viscosity at the time of coating of the curable composition, and has excellent coatability regardless of the ambient environment. Therefore, for example, in applying the curable composition using a comb-shaped trowel, even an unskilled person can easily and uniformly apply the curable composition onto the underfloor material.

Furthermore, since the curable composition has high thixotropic properties, the curable composition maintains a comb-like shape on the coated surface even after the curable composition is applied using a comb-like trowel. is doing.

Since the curable composition maintains a pectinate morphology, air can flow smoothly through the valleys formed between the adjacent curable compositions, and the curable composition can be placed on the surface of the curable composition. It can be cured evenly. Therefore, after the floor finishing material is pasted onto the underfloor material, the floor finishing material can be immediately temporarily adhered onto the underfloor material, and the floor finishing material can be laid at an accurate position on the underfloor material. can.

Furthermore, by pressing the floor finishing material toward the underfloor material, the curable composition applied in a pectinate form is formed between the floor finishing material and the underfloor material so that the curable composition is adjacent to each other. By being spread out by the valleys formed between the objects, it is in a state of uniform existence.

Therefore, even if the floor finishing material is thin and easily deformable, the floor finishing material can be uniformly supported on the underfloor material via the curable composition, without deforming the floor finishing material. It can be laid and integrated on the underfloor material, and a flat and beautiful finished surface without unevenness can be constructed.

In addition, since the curable composition does not need to contain a solvent, the curable composition does not emit a solvent odor during use and the cured product of the curable composition, which is excellent in terms of environmental hygiene.

The curable composition of the present invention is cured by moisture in the air and moisture contained in adherends such as building members (for example, floor finishing materials and underfloor materials) to strengthen adherends to each other. can be integrated into

The curable composition of the present invention has low viscosity and high thixotropy. Therefore, the curable composition has excellent coatability and, for example, when applied using a comb-like trowel, the curable composition maintains a comb-like shape after the application. .

Then, the curable composition is easily spread between the members to be adhered by the stress that causes the members to be adhered to approach each other, and is in a state of being uniformly present. Therefore, the members to be bonded can be firmly and uniformly bonded together by the cured product of the curable composition.

EXAMPLES The aspects of the present invention will be described in more detail below with reference to Examples, but the present invention is not limited to these Examples.

The following raw materials were used in the preparation of the curable compositions of Examples and Comparative Examples.

[Polyoxyalkylene polymer (A) having a crosslinkable silyl group]
- Polyoxyalkylene polymer (A1) having a crosslinkable silyl group (polyoxypropylene polymer having a dimethoxysilyl group as a crosslinkable silyl group and a main chain skeleton of polyoxypropylene, having a urethane bond No, number average molecular weight: 15000, molecular weight distribution: 1.10, product name “Exester 6250” manufactured by Asahi Glass Co., Ltd.)
- Polyoxyalkylene polymer (A2) having a crosslinkable silyl group (polyoxypropylene polymer having a dimethoxysilyl group as a crosslinkable silyl group and a main chain skeleton of polyoxypropylene, having a urethane bond No, number average molecular weight: 10000, molecular weight distribution: 1.49, Kaneka product name “Silyl EST280”)
- Polyoxyalkylene polymer (A3) having a crosslinkable silyl group (polyoxypropylene polymer having a dimethoxysilyl group as a crosslinkable silyl group and a main chain skeleton of polyoxypropylene, having a urethane bond No, number average molecular weight: 20000, molecular weight distribution: 1.16, product name “Exester 4530” manufactured by Asahi Glass Co., Ltd.)

[Calcium carbonate (B)]
・Surface-treated precipitated calcium carbonate (B1) (average particle size of primary particles: 0.05 μm, surface treatment with fatty acid, product name “Calfine 200M” manufactured by Maruo Calcium Co., Ltd.)
・ Surface untreated heavy calcium carbonate (B2) (average particle size of primary particles: 5 μm, product name “Whiten P-30” manufactured by Toyo Fine Chemical Co., Ltd.)

[Silane coupling agent (C)]
・ Amino group-containing silane coupling agent (C1) [N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, product name “KBM-603” manufactured by Shin-Etsu Chemical Co., Ltd.]
・ Epoxy group-containing silane coupling agent (C2) [3-glycidoxypropyltriethoxysilane, product name “KBM-403” manufactured by Shin-Etsu Chemical Co., Ltd.]

(Examples 1 to 6 , Comparative Examples 1 to 11 )
Polyoxyalkylene polymer having a crosslinkable silyl group (A), calcium carbonate (B), silane coupling agent (C), plasticizer, silanol condensation catalyst, dehydrating agent and antioxidant are shown in Table 1. A curable composition was prepared by uniformly mixing the ingredients while reducing the pressure in a sealed stirrer so that the blended amount was equal to the above. The number average molecular weight of the polyoxyalkylene polymer (A) having a crosslinkable silyl group is shown in the "number average molecular weight" column. In Table 1, "polyoxyalkylene polymer having a crosslinkable silyl group" is simply written as "polyoxyalkylene polymer".

For the resulting curable composition, the viscosity at 23 ° C., the ratio of the viscosity at 1 rpm at 23 ° C. and the viscosity at 10 rpm at 23 ° C. (viscosity at 1 rpm/viscosity at 10 rpm) were measured in the above manner. Table 1 shows the results. In addition, in Table 1, "viscosity at 23°C" is described in the "viscosity" column. In Table 1, "the ratio of the viscosity at 1 rpm at 23°C and the viscosity at 10 rpm at 23°C (viscosity at 1 rpm/viscosity at 10 rpm)" is described in the "viscosity ratio (1 rpm/10 rpm)" column. .

The resulting curable composition was measured for comb shape retention, normal state adhesiveness, water immersion adhesiveness and storage stability in the following manner, and the results are shown in Table 1.

(Comb-like shape maintenance property)
The curable composition was applied onto a mortar plate using a comb-shaped trowel conforming to JIS A5536. The height of the pile of the curable composition immediately after coating the curable composition on the mortar plate, and the height of the pile of the curable composition one minute after the coating of the curable composition on the mortar plate. Evaluation was made based on the following criteria based on the rate of change in height (height of ridges of curable composition after one minute elapsed/height of ridges of curable composition immediately after coating).
Good: 0.9 or more and 1.0 or less.
(triangle|delta)... It was 0.7 or more and less than 0.9.
×: Less than 0.7.

(normal state adhesiveness)
The normal state adhesiveness of the curable composition was measured according to JIS A5536 5.3.3 e)1). Specifically, a sheet commercially available from Takiron under the product name "Takistron PRENTO PRE-81" was used as the floor finishing material. A slate plate (JIS A5536 Table 7) having a thickness of 5 mm was used as the underfloor material. Based on the strength standard of JIS A5536, evaluation was made using the following criteria.

A: 30 N/25 mm or more.
Good: 20 N/25 mm or more and less than 30 N/25 mm.
x: Less than 20 N/25 mm.

(Water immersion adhesion)
The adhesiveness of the curable composition in water immersion was measured according to JIS A5536 5.3.3 e)2) and evaluated using the results. A sheet commercially available from Takiron under the product name "Takistron PRENTO PRE-81" was used as the floor finishing material. A slate plate (JIS A5536 Table 7) having a thickness of 5 mm was used as the underfloor material. Based on the strength standard of JIS A5536, evaluation was made using the following criteria.
A: 20 N/25 mm or more.
Good: 10 N/25 mm or more and less than 20 N/25 mm.
x: Less than 10 N/25 mm.

(Storage stability)
The viscosity of the curable composition at 23° C. was measured according to JIS K6833 using a Brookfield viscometer at a rotation speed of 10 rpm, and the viscosity of the resulting curable composition was defined as the “initial viscosity”.

After filling 300 g of the curable composition into a mayonnaise bottle, the air in the mayonnaise bottle was removed, nitrogen filling was performed, and the mayonnaise bottle was sealed so as to be in a sealed state. After leaving the mayonnaise bottle at 50° C. for one month, the mayonnaise bottle was opened.

The viscosity of the curable composition in the mayonnaise bottle at 23 ° C. was measured using a Brookfield viscometer at a rotation speed of 10 rpm in accordance with JIS K6833. Viscosity after 1 month". The viscosity change was calculated based on the following formula and evaluated based on the following criteria.
Viscosity change = (viscosity after 1 month at 50°C)/(initial viscosity)

Good: Viscosity change was less than 1.5.
(triangle|delta)... Viscosity change was 1.5 or more and less than 2.0.
x: Viscosity change was 2.0 or more.

Claims (3)

100 parts by mass of a polyoxyalkylene polymer (A) having a crosslinkable silyl group and a number average molecular weight of 18000 or less;
40 to 80 parts by mass of precipitated calcium carbonate and 120 to 250 parts by mass of surface-untreated ground calcium carbonate, and the content ratio of the precipitated calcium carbonate to the surface-untreated ground calcium carbonate (precipitated carbonate calcium carbonate (B) having a calcium content/surface-untreated heavy calcium carbonate content) of 0.1 to 1.0;
containing an amino group-containing silane coupling agent (C1) and an epoxy group-containing silane coupling agent (C2), and the content of the amino group-containing silane coupling agent (C1) and the epoxy group-containing silane coupling agent ( C2) contains 3 to 6 parts by mass of a silane coupling agent (C) having a content ratio (C1/C2) of 2.0 to 10,
It has a viscosity of 15,000 to 100,000 mPa s at 23 ° C., and the ratio of the viscosity at 1 rpm at 23 ° C. and the viscosity at 10 rpm at 23 ° C. (viscosity at 1 rpm/viscosity at 10 rpm) is 5 to 10. A curable composition characterized by being 2. The curable composition according to claim 1, wherein the polyoxyalkylene polymer (A) having a crosslinkable silyl group has a number average molecular weight of 18,000 or less. A floor adhesive comprising the curable composition according to claim 1 or 2 .