JP2010047697A - Curable composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a curable composition which has excellent storage stability, is especially free from toxicity (or low in toxicity), is less in adverse effect to the environment and is good in workability by virtue of its low viscosity. <P>SOLUTION: The curable composition contains an isocyanate group-containing urethane prepolymer (A), a filler (B-1), a thixotropic agent (B-2), a carbonate solvent (C) and a naphthene-containing aliphatic hydrocarbon solvent (D). Further, it is preferable that additives (E) such as a hindered amine-based light stabilizer and/or a hindered phenol-based antioxidant are blended. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a curable composition containing an isocyanate group-containing urethane prepolymer and having low toxicity and improved adverse environmental effects.

The curable composition containing an isocyanate group-containing urethane prepolymer has excellent properties such as adhesiveness after curing and rubber elasticity. Adhesives for construction, civil engineering and automobiles, sealing materials, paints Although the urethane group of the isocyanate group-containing urethane prepolymer has a strong cohesive force because it forms hydrogen bonds, it has excellent adhesion and rubber elasticity, but because of its strong cohesiveness, urethane is used. The prepolymer has a high viscosity, and the viscosity of the curable composition containing the prepolymer is also high, so that the workability is poor. Therefore, it is necessary to use an organic solvent in order to reduce the viscosity of the curable composition and improve workability such as coating and filling, and conventionally, it is excellent in solubility and inexpensive with respect to the urethane prepolymer. Due to the advantages, aromatic organic solvents such as toluene and xylene are widely used. However, aromatic organic solvents directly harm the health of workers and indirectly cause pollution to the environment by being released into the atmosphere, which in turn causes damage to the health and life of people, animals and plants. In addition, it is considered as a causative substance that causes sick house syndrome if it is released into the living space.
In recent years, with the growing awareness of protecting the global environment, products that do not use the above aromatic organic solvents as solvents are strongly desired.
In order to solve the above-mentioned problem, the present applicant has found in the past that a carbonate ester-based organic solvent is used, and a curing in which a carbonate ester-based organic solvent and a water-reactive compound are blended with an isocyanate group-containing urethane prepolymer. The curable composition and the curable composition which mix | blended the oxazolidine compound, the hardening accelerator, and the carbonate compound with the isocyanate group containing urethane prepolymer were proposed (refer patent document 1 and patent document 2). However, these have the advantage of being excellent in storage stability and anti-foaming property, but in order to obtain a non-toxic curable composition, in the system in which an inorganic filler such as calcium carbonate is present, a carbonate ester as a solvent. It has been found that when only the organic solvent is used, the viscosity is increased and the workability is lowered.
Moreover, although the organic solvent type adhesive agent which does not have the toxicity and bad smell which have dimethyl carbonate as a main component of a solvent is also disclosed (refer patent document 3), it has the fault that workability | operativity at low temperature is inferior like the above.
Also disclosed is a moisture curable urethane composition comprising a combination of an isocyanate group-containing urethane prepolymer and an oxazolidine compound and one or more organic solvents such as naphtha hydrocarbons, naphthene hydrocarbons, and paraffin hydrocarbons. (See Patent Document 4). However, this is superior in anti-foaming properties and has the advantage of not containing an organic solvent stipulated in the organic solvent poisoning prevention regulations, but has poor solubility in additives such as urethane prepolymers and hindered amine light stabilizers. Has drawbacks.
JP 2006-36881 A JP 2007-284547 A JP-A-9-279110 JP 2003-268066 A

  The present invention solves the above-mentioned problems, has a high storage stability, is not particularly toxic (or has low toxicity), has a small adverse effect on the environment, and has good workability due to low viscosity. The purpose is to provide.

  As a result of studies conducted in view of the above problems, the present inventors have found that a curable composition containing an isocyanate group-containing urethane prepolymer and a filler or thixotropic agent is used as an organic solvent, a carbonate ester solvent and a naphthene-containing aliphatic carbonization. It has been found that the above problem can be solved by using a combination of hydrogen solvents, and the present invention has been achieved.

That is, the present invention
(1) It contains an isocyanate group-containing urethane prepolymer (A), a filler (B-1), a carbonate ester solvent (C), and a naphthene-containing aliphatic hydrocarbon solvent (D). It is a curable composition.
Or
(2) containing an isocyanate group-containing urethane prepolymer (A), a thixotropic agent (B-2), a carbonate ester solvent (C), and a naphthene-containing aliphatic hydrocarbon solvent (D). It is a curable composition characterized.
Or
(3) Isocyanate group-containing urethane prepolymer (A), filler (B-1), thixotropic agent (B-2), carbonate solvent (C), naphthene-containing aliphatic hydrocarbon solvent ( D) and a curable composition characterized by containing.
In the present invention,
(4) The filler (B-1) is preferably calcium carbonate,
(5) The thixotropic agent (B-2) is preferably a fatty acid surface-treated calcium carbonate,
(6) The carbonate ester solvent (C) is preferably dimethyl carbonate,
Also,
(7) The naphthene content in the naphthene-containing aliphatic hydrocarbon solvent (D) is preferably 20 to 100% by mass, and the aromatic content is preferably 1% by mass or less.
And in the present invention,
(8) Furthermore, it is preferable to blend an additive (E) other than the filler (B-1) and the thixotropic agent (B-2),
(9) It is preferable that the additive (E) is a hindered amine light stabilizer and / or a hindered phenol antioxidant.
In the present invention,
(10) The aromatic content of the curable composition is particularly preferably 1% by mass or less.

  By adopting the above-described configuration, the curable composition of the present invention has excellent storage stability, is not particularly toxic (or has low toxicity), and does not adversely affect the environment. The effect of being excellent in workability due to being low.

The present invention will be described in detail below.
First, the isocyanate group-containing urethane prepolymer (A) will be described.
The isocyanate group-containing urethane prepolymer (A) is obtained by reacting an organic isocyanate compound and an active hydrogen-containing compound with active hydrogen (group) under an excess of isocyanate groups, and is contained in the prepolymer molecule. In the curable composition of the present invention, the isocyanate group to be reacted reacts with moisture such as moisture to form a urea bond, and is contained as a curing component.
Specifically, the active hydrogen-containing compound and the organic isocyanate compound have a molar ratio of raw material isocyanate group / active hydrogen (group) of 1.2 to 10 / 1.0, preferably 1.5 to 5.0 /. The reaction can be carried out simultaneously or sequentially within a range of 1.0 so that the isocyanate group remains in the urethane prepolymer (A). When the molar ratio is less than 1.2 / 1.0, the resulting urethane prepolymer (A) has too few cross-linking points, and the curable composition has decreased elongation, tensile strength, and the like, and rubber elastic properties. If the molar ratio exceeds 10 / 1.0, the amount of carbon dioxide generated when reacting with moisture increases and causes foaming, which is not preferable.
Further, the isocyanate group content of the isocyanate group-containing urethane prepolymer (A) is preferably 0.3 to 15.0 mass%, particularly preferably 0.5 to 5.0 mass%. When the isocyanate group content is less than 0.3% by mass, the viscosity of the prepolymer (A) is increased, workability is deteriorated, the crosslinking point is small and sufficient adhesiveness is not obtained, and the isocyanate group content is 15 If it exceeds 0.0 mass%, the amount of carbon dioxide generated by the reaction with moisture increases, the cured product foams, and the rubber elastic properties become brittle.
As a production method, an active hydrogen-containing compound and an organic isocyanate compound are charged into a reaction vessel made of glass or stainless steel and reacted at 50 to 120 ° C. in the presence or absence of a reaction catalyst or an organic solvent described later. The method etc. are mentioned. At this time, when the isocyanate group reacts with moisture, the resulting urethane prepolymer (A) is thickened. Therefore, the reaction is preferably performed in a state where moisture is blocked, such as nitrogen gas replacement or under a nitrogen gas stream.
The isocyanate group-containing urethane prepolymer (A) can be used as a one-component moisture-curing type by reacting and curing the contained isocyanate group with moisture in the atmosphere (humidity) at room temperature.

Examples of the organic isocyanate compound include organic polyisocyanate and organic monoisocyanate that is optionally used for modifying the isocyanate group-containing urethane prepolymer (A). Further, as the organic polyisocyanate, the isocyanate group is bonded to aromatic carbon. And an aromatic polyisocyanate having an isocyanate group bonded to an aliphatic carbon.
Aromatic polyisocyanates include 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, or mixtures thereof such as diphenylmethane diisocyanates (MDIs); 2,4-toluene diisocyanate, 2,6-toluene Toluene diisocyanates (TDIs) such as diisocyanates or mixtures thereof; other examples include phenylene diisocyanate, diphenyl diisocyanate, naphthalene diisocyanate, diphenyl ether diisocyanate and the like.
Aliphatic polyisocyanates include aromatic rings such as xylylene diisocyanate and aromatic groups bonded to aliphatic carbon; hexamethylene diisocyanate, pentamethylene diisocyanate, propylene diisocyanate, butylene diisocyanate, etc. Aliphatic polyisocyanates composed of the following chain hydrocarbons; alicyclic polyisocyanates having alicyclic hydrocarbons such as cyclohexane diisocyanate, methylene bis (cyclohexyl isocyanate), and isophorone diisocyanate.
In addition, carbodiimide-modified products, biuret-modified products, allophanate-modified products, or polymethylene polyphenyl polyisocyanates (also referred to as crude MDI or polymeric MDI) of these diisocyanates may be mentioned, and these may be used alone or in combination of two or more. Can be used.
Among these, MDIs are preferable among aromatic polyisocyanates because they are excellent in rubber elasticity and weather resistance after curing. Among aliphatic polyisocyanates, xylylene diisocyanate, hexamethylene diisocyanate, isophorone are preferred. Diisocyanate is preferred.
In addition, as a modification of the isocyanate group-containing urethane prepolymer (A), the organic monoisocyanate used in some cases includes aliphatic monoisocyanates such as n-butyl monoisocyanate, n-hexyl monoisocyanate, and n-octadecyl monoisocyanate. Can be mentioned.

Examples of the active hydrogen-containing compound include a low-molecular polyol, a low-molecular amino alcohol, a low-molecular polyamine, or an isocyanate group-containing urethane prepolymer (A ) And a low molecular weight monool.
Examples of the polymer polyol include polyester polyol, polycarbonate polyol, polyoxyalkylene polyol, hydrocarbon polyol, animal and plant polyol, these copolyols, or a mixture of two or more thereof.
The number average molecular weight in terms of polystyrene by gel permeation chromatography of the polymer polyol is preferably 1,000 to 100,000, more preferably 1,000 to 30,000, and particularly preferably 1,000 to 20,000. If the number average molecular weight is less than 1,000, rubber elastic properties such as elongation after curing of the resulting curable composition deteriorate, and if it exceeds 100,000, the viscosity of the resulting isocyanate group-containing urethane prepolymer (A). Is excessively high, and workability is deteriorated.

Polyester polyols include succinic acid, adipic acid, sebacic acid, azelaic acid, terephthalic acid, isophthalic acid, orthophthalic acid, hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydroorthophthalic acid, naphthalenedicarboxylic acid, trimellitic acid, etc. One or more of these acid anhydrides or alkyl esters such as methyl ester and ethyl ester, and ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 1,8-octanediol 1,9-nonanediol, die Or one or more low molecular polyols such as lenglycol, dipropylene glycol, 1,4-cyclohexanedimethanol, ethylene oxide or propylene oxide adduct of bisphenol A, trimethylolpropane, glycerin, pentaerythritol; or In addition, it can be obtained by dehydration or dealcoholization condensation reaction with one or more of low molecular weight polyamines such as butylene diamine, hexamethylene diamine, xylylene diamine, isophorone diamine, and low molecular amino alcohols such as monoethanolamine and diethanolamine. Also included are polyester polyols or polyesteramide polyols.
Also, lactone polyester polyols obtained by ring-opening polymerization of cyclic ester (lactone) monomers such as ε-caprolactone and γ-valerolactone using low molecular polyols, low molecular polyamines, and low molecular amino alcohols as initiators Can be mentioned.
As polycarbonate polyol, dehydrochlorination reaction of low molecular polyols and phosgene used for the synthesis of the above-mentioned polyester polyol, or transesterification reaction of low molecular polyols with diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, etc. Can be obtained.

Examples of the polyoxyalkylene polyol include low molecular polyols, low molecular polyamines, low molecular amino alcohols and polycarboxylic acids similar to those used for the synthesis of the polyester polyol described above; sorbitol, mannitol, sucrose ( Sucrose), sugar-based low molecular weight polyhydric alcohols such as glucose; cyclic ethers such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using one or more low molecular weight polyphenols such as bisphenol A and bisphenol F as initiators Polyoxyethylene polyol, polyoxypropylene polyol, polyoxybutylene polyol obtained by ring-opening addition polymerization or copolymerization (hereinafter, “polymerization or copolymerization” is referred to as (co) polymerization) of one or more compounds. , Polyoxy Toramechiren polyols, poly - (oxyethylene) - (oxypropylene) - random or block copolymers based polyols, further polyester polyether polyol initiator polyester polyols and polycarbonate polyols described above, such as polycarbonate polyether polyols. Moreover, the polyol which made these various polyols and an organic isocyanate compound react with hydroxyl group excess with respect to an isocyanate group, and made the molecular terminal a hydroxyl group is also mentioned.
The average number of alcoholic hydroxyl groups per molecule of the polyoxyalkylene polyol is preferably 2 or more, more preferably 2 to 4, and particularly preferably 2 to 3.
Furthermore, the polyoxyalkylene-based polyol is produced at the time of production thereof by cesium hydride, cesium methoxide, cesium alkoxide such as cesium ethoxide, cesium-based compounds such as cesium hydroxide, diethyl zinc, iron chloride, metalloporphyrin, phosphazenium compound, The total unsaturation obtained by using a double metal cyanide complex such as a double metal cyanide complex such as a zinc hexacyanocobaltate glyme complex or diglyme complex as a catalyst is 0.1 meq / g or less. 07 meq / g or less, particularly 0.04 meq / g or less is preferable, and molecular weight distribution [ratio of weight average molecular weight (Mw) and number average molecular weight (Mn) in terms of polystyrene by gel permeation chromatography (GPC) = Mw / Mn] is 1.6 or less, especially 1.0 1.3 narrow is the viscosity of the resulting isocyanate group-containing urethane prepolymer (A) can decrease, and rubber elasticity properties after curing of the curable composition obtained is preferable in that is good.

For the modification of the isocyanate group-containing urethane prepolymer (A), a cyclic ether compound such as propylene oxide is subjected to ring-opening addition polymerization using a low-molecular monoalcohol such as methyl alcohol, ethyl alcohol or propyl alcohol as an initiator. In addition, polyoxyalkylene monools such as polyoxypropylene monools may be used in some cases.
The “system” such as the polyoxyalkylene polyol or polyoxyalkylene monool is 50% by mass or more, more preferably 80% by mass or more, particularly preferably 90% by mass of the portion excluding the hydroxyl group in 1 mol of the molecule. % Or more is composed of polyoxyalkylene, which means that the remaining part may be modified with ester, urethane, polycarbonate, polyamide, poly (meth) acrylate, polyolefin, etc., except for hydroxyl groups. Most preferably, 95% by mass or more of the molecules consist of polyoxyalkylene.
Examples of hydrocarbon polyols include polyolefin polyols such as polybutadiene polyol and polyisoprene polyol; polyalkylene polyols such as hydrogenated polybutadiene polyol and hydrogenated polyisoprene polyol; halogenated polyalkylene polyols such as chlorinated polypropylene polyol and chlorinated polyethylene polyol Etc.
As a poly (meth) acrylate-based polyol, a (meth) acrylate monomer containing a hydroxyl group such as hydroxyethyl (meth) acrylate and another (meth) acrylic acid alkyl ester monomer are used as radical polymerization initiators. And copolymerized in the presence or absence of.
Examples of animal and plant-based polyols include castor oil diol.
As the chain extender, the same polyoxyalkylene polyol as described above in addition to low molecular weight polyols, polyamines, amino alcohols similar to those used in the synthesis of the polyester polyol, and the number average molecular weight is less than 1,000. Of low molecular weight, or a mixture of two or more thereof.
The compounds mentioned as the active hydrogen-containing compound can be used alone or in combination of two or more, but among these, the rubber elastic properties and adhesiveness of the resulting curable composition are good. Polymer polyols are preferred, polyoxyalkylene polyols are more preferred, and polyoxypropylene polyols are most preferred.

Next, the filler (B-1) and thixotropic agent (B-2) used in the curable composition of the present invention will be described.
Filler (B-1) is a kind of additive that is added to the curable composition comprising the isocyanate group-containing urethane prepolymer (A) for the purpose of reinforcement or weight gain. An inorganic filler and an organic filler. Is mentioned. Inorganic fillers include calcium carbonate such as heavy calcium carbonate ground natural calcium carbonate or fine powdered synthetic calcium carbonate called precipitated calcium carbonate or light calcium carbonate, mica, kaolin, zeolite, graphite , Diatomaceous earth, white clay, clay, talc, silicic anhydride, quartz, aluminum powder, zinc powder, calcium hydroxide, magnesium carbonate, alumina and other inorganic powder fillers; glass fiber, carbon fiber and other inorganic fibrous fillers And inorganic balloon fillers such as glass balloons, shirasu balloons, silica balloons and ceramic balloons. Organic fillers include organic powder fillers such as wood flour, walnut flour, rice husk flour, pulp powder, rubber powder, thermoplastic or thermosetting resin powder; Examples include balloon-like fillers. Other examples include flame retardant fillers such as magnesium hydroxide and aluminum hydroxide, and these can be used alone or in combination of two or more.
Of these, inorganic fillers are preferred, calcium carbonate is more preferred, and heavy calcium carbonate is particularly preferred because of its high reinforcing and increasing effects. The particle size of the filler is preferably 0.01 to 1,000 μm.
The usage-amount of a filler (B-1) is 1-500 mass parts with respect to 100 mass parts of isocyanate group containing urethane prepolymer (A), Furthermore, 10-300 mass parts, Especially 10-200 mass parts is preferable. If it is less than 1 part by mass, there is no effect of reinforcing or increasing the amount of the curable composition obtained, and if it exceeds 500 parts by mass, the cured product becomes fragile, which is not preferable.

Thixotropy imparting agent (B-2) is applied and filled on vertical and inclined surfaces such as building interior and exterior walls and floors when the curable composition of the present invention is used as an adhesive, sealing material, paint, etc. It is a kind of additive used for the purpose of imparting thixotropy to the curable composition so as not to cause sagging or flow during construction. As thixotropic agents, fine silica such as hydrophilic or hydrophobic colloidal silica, inorganic thixotropic agents such as fatty acid surface-treated calcium carbonate; organic thixotropic agents such as organic bentonite and fatty acid amide, etc. These can be used singly or in combination of two or more. Among them, inorganic thixotropic agents are preferred, and fatty acids are more preferable because they can impart stable thixotropic properties to the curable composition. Surface treated calcium carbonate is preferred.
Fatty acid surface-treated calcium carbonate includes finely ground synthetic calcium carbonate called precipitated calcium carbonate and light calcium carbonate, or the surface of calcium carbonate such as heavy calcium carbonate pulverized by pulverizing natural calcium carbonate. Are treated with fatty acids such as fatty acids, fatty acid alkyl esters, fatty acid metal salts, resin acids such as rosin acid or metal salts thereof for the purpose of imparting thixotropy imparting ability and preventing secondary aggregation. Examples of the fatty acid include fatty acids having 10 to 25 carbonic acids such as stearic acid, and examples of metal salts thereof include sodium salts, potassium salts, calcium salts, and aluminum salts. Examples of these commercially available products include Shiraishi Kogyo Co., Ltd., White Gloss Flower CC, White Gloss Flower CCR, White Gloss Flower R06, VIGOT-10, VIGOT-15, STAVIGOT-15A; These can be used singly or in combination of two or more. Among these, synthetic calcium carbonate surface-treated with a fatty acid or a fatty acid metal salt is preferable, and stearic acid or a sodium stearate salt is more preferable. Synthetic calcium carbonate surface-treated with is preferable. In the present invention, fatty acids and alkyl esters of resin acids and metal salts are also referred to as fatty acids.
The average particle size of the fatty acid surface-treated calcium carbonate is preferably 0.01 to 1.0 μm, more preferably 0.03 to 0.3 μm, and the BET specific surface area is 5 to 200 m ² / g, further 10 to 60 m ² / g. Is preferred. When the average particle diameter is less than 0.01 μm, or the BET specific surface area exceeds 200 m ² / g, the viscosity of the resulting curable composition is increased and the workability is deteriorated, and the average particle diameter is more than 1.0 μm, Alternatively, if the BET specific surface area is less than 5 m ² / g, the thixotropic imparting effect is lowered, which is not preferable.
The amount of thixotropic agent (B-2) used is preferably 1 to 200 parts by weight, more preferably 5 to 150 parts by weight, based on 100 parts by weight of the isocyanate group-containing urethane prepolymer (A). If it is less than 1 part by mass, the thixotropic effect is lost, and if it exceeds 200 parts by mass, the viscosity of the resulting curable composition is increased and workability is deteriorated.

  In addition, in this invention, according to the use of a curable composition, you may use the said filler (B-1) and thixotropic imparting agent (B-2) individually, respectively, or a curable composition. On the other hand, a filler (B-1) and a thixotropic agent (B-2) may be used in combination for the purpose of imparting thixotropy together with reinforcement and increasing amount.

Next, the organic solvent which combined the carbonate ester solvent (C) and the naphthene containing aliphatic hydrocarbon solvent (D) in this invention is demonstrated.
Only the carbonate solvent (C) is used for the purpose of reducing the viscosity of the curable composition comprising the isocyanate group-containing urethane prepolymer (A) and the filler (B-1) or thixotropic agent (B-2). Is used, the solubility in an isocyanate group-containing urethane prepolymer (A) and a weather resistance improver such as a hindered amine light stabilizer to be used later is good, but the polarity of the carbonate solvent (C) Is presumed to be because the dispersibility of the filler (B-1) and thixotropic agent (B-2) is low, but the viscosity of the resulting curable composition is increased, and the extrusion, coating, etc. The problem that workability | operativity will fall arises, and when only a naphthene containing aliphatic hydrocarbon solvent (D) is used, a urethane prepolymer (A), the below-mentioned hindered amine light stabilizer, etc. The solubility of the weather resistance improver and the like is poor, and the resulting curable composition becomes inhomogeneous, resulting in poor performance such as deterioration in appearance, but the carbonate solvent (C) and the naphthene-containing aliphatic hydrocarbon solvent ( When used in combination with D), while maintaining excellent solubility in the isocyanate group-containing urethane prepolymer (A) and weather resistance improver, the viscosity of the resulting curable composition is prevented from increasing, and workability is improved. There is an effect that becomes good.
In the combination of the carbonate ester solvent (C) and the naphthene-containing aliphatic hydrocarbon solvent (D), the ratio of the solvent (D) to the solvent (C) is solvent (D) / solvent (C) = 20 by mass ratio. / 80 to 90/10, more preferably 30/70 to 80/20. The ratio of naphthene (also referred to as naphthene in the catalog of general commercial products) in the naphthene-containing aliphatic hydrocarbon solvent (D) to the carbonate solvent (C) is naphthene / carbonic acid in mass ratio. Ester solvent (C) = 5/95 to 90/10, more preferably 20/80 to 80/20. Use ratio of naphthene-containing aliphatic hydrocarbon solvent (D) to carbonate ester solvent (C) is less than 20/80, or use of naphthene in naphthene-containing aliphatic hydrocarbon solvent (D) to carbonate ester solvent (C) When the ratio is less than 5/95, the viscosity of the curable composition is increased and the workability is lowered. When the ratio is more than 90/10, the solubility of the isocyanate group-containing urethane prepolymer (A) and the weather resistance improver is increased. Is not preferable.
The total amount of the organic solvent including the carbonic acid ester solvent (C), the naphthene-containing aliphatic hydrocarbon solvent (D), and other solvents to be used as necessary is 1 to 40 mass of the entire curable composition. %, And an amount of 3 to 30% by mass is preferred. If the amount is less than 1% by mass, the effect of lowering the viscosity of the curable composition is small. If it exceeds 40% by mass, the organic solvent used in the present invention is less toxic to the atmosphere during the curing process even if the toxicity of the organic solvent itself is low. This is not preferable because the amount of the solvent increases and adversely affects the environment. This usage amount is preferably applied when the use of the curable composition is an adhesive or a paint, and when the use is a sealing material, the total usage amount of the organic solvent is the same as the whole sealing material for the same reason as described above. 1 to 10% by mass is preferable, and 1 to 4% by mass is more preferable.

  The carbonate ester solvent (C) has a carbonate ester bond (—O—C (O) —O—) in the molecule, and has a melting point or freezing point of 4 ° C. or less, preferably 1 ° C. or less, and a boiling point of 300 ° C. or less, preferably Is a liquid compound at room temperature of 250 ° C. or lower, and specific examples include dimethyl carbonate (also referred to as DMC), diethyl carbonate, propylene carbonate, and the like. Although these can be used individually or in combination of 2 or more types, among these, dimethyl carbonate and propylene carbonate are preferable in terms of good solubility, and dimethyl carbonate is particularly preferable.

The naphthene-containing aliphatic hydrocarbon solvent (D) is an aliphatic organic solvent containing at least naphthene (naphthenic hydrocarbon compound) in the hydrocarbon solvent. Naphthene alone or naphthene and paraffin (paraffinic hydrocarbon compound) And a liquid obtained by hydrogenating a petroleum fraction or petroleum fraction. The initial boiling point of the naphthene-containing aliphatic hydrocarbon solvent (D) is preferably 80 to 300 ° C, more preferably 100 to 250 ° C. If the initial boiling point is less than 80 ° C., the risk of ignition increases, and if it exceeds 300 ° C., evaporation is slow, which is not preferable.
General commercial products of naphthene-containing aliphatic hydrocarbon solvent (D) include Exxon Chemical's Exol series DSP100 / 140, D30, D40, D80, D110, D130; Shell Chemical's Shellsol series D60, D70. ; Suwaclean 150 from Maruzen Petrochemical Co., Ltd.
Specific examples of naphthene include alicyclic hydrocarbon compounds (cycloalkanes) such as methylcyclohexane, ethylcyclohexane, diethylcyclohexane, and methylethylcyclohexane, each alone or a mixture of two or more.
Cyclohexane is a kind of naphthenic compound, but has a low flash point (−20 ° C.) and a high freezing point (6.5 ° C.). It is preferable not to use the composition because it reduces the workability of the composition at low temperatures.
The naphthene content in the naphthene-containing aliphatic hydrocarbon solvent (D) is preferably 20 to 100 mass%, more preferably 30 to 100 mass%. If the content of naphthene is less than 20% by mass, the content of paraffin increases and the solubility of the isocyanate group-containing urethane prepolymer (A) and the like is not preferable.
In order to achieve the object of the present invention, a volatile aromatic hydrocarbon (also referred to as an aromatic component in the present invention) as an organic solvent component in the naphthene-containing aliphatic hydrocarbon solvent (D) is contained. The amount is preferably 1% by mass or less, more preferably 0.5% by mass or less. Thereby, the content of the volatile aromatic hydrocarbon compound (aromatic component) contained in the entire curable composition of the present invention obtained is 1% by mass or less, more preferably 0.2% by mass or less, particularly preferably 0. .1% by mass or less, and particularly excellent in toxicity and low adverse effects on the environment.
In the present invention, a known organic solvent such as an ester solvent such as ethyl acetate, a ketone solvent such as acetone or methyl ethyl ketone, if necessary, in addition to the carbonate solvent (C) and the naphthene-containing aliphatic hydrocarbon solvent (D). It is also possible to use other solvents that do not react with isocyanate groups at the same time, but for the purposes of health protection and environmental protection as described above, it is necessary not to use aromatic organic solvents such as toluene and xylene. The amount of the other solvent used is also preferably suppressed to 5% by mass or less, more preferably 4% by mass or less, based on the entire curable composition.

  Next, in the present invention, in addition to the components (A), (B-1), (B-2), (C) and (D), it is preferable to further blend, a weather resistance improver, adhesiveness The improver, the storage stability improver, the colorant, the plasticizer, the curing accelerating catalyst and the like will be described. These belong to the additive (E) other than the filler (B-1) and the thixotropic agent (B-2), and these additives (E) and the compounds described later in these additives (E) Can be used alone or in combination of two or more.

The weather resistance improver is used to prevent oxidation, light deterioration, and heat deterioration of the cured product, and to further improve not only the weather resistance but also the heat resistance. Specifically, the weather resistance improver is a hindered amine light stabilizer. , Hindered phenol antioxidants, ultraviolet absorbers and the like.
Examples of hindered amine light stabilizers include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) [{3,5 -Bis (1,1-dimethylethyl) -4-hydroxyphenyl} methyl] butyl malonate, methyl 1,2,2,6,6-pentamethyl-4-piperidyl sebacate, bis (1,2,2,6 , 6-pentamethyl-4-piperidyl) sebacate, 1- [2- {3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionyloxy} ethyl] -4- {3- (3,5 -Di-tert-butyl-4-hydroxyphenyl) propionyloxy} -2,2,6,6-tetramethylpiperidine, 4-benzoyloxy-2,2,6,6-tetramethylpi In addition to lysine, ADEKA's trade name ADK STAB series LA-52, LA-57, LA-62, LA-67, LA-77, LA-82, LA-87, etc. Hindered amine light stabilizers of the same; Adequastab series of LA-63P, LA-68LD, Ciba Specialty Chemicals' trade name CHIMASSORB series of 119FL, 2020FDL, 944FD, 944LD, etc. Examples thereof include hindered amine light stabilizers.
As the hindered phenol-based antioxidant, pentaerythritol-tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], octadecyl-3- (3,5-di-tert-butyl) -4-hydroxyphenyl) propionate, N, N'-hexane-1,6-diylbis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propioamide], benzenepropanoic acid, 3,5- Examples include bis (1,1-dimethylethyl) -4-hydroxy, C7-C9 side chain alkyl ester, 2,4-dimethyl-6- (1-methylpentadecyl) phenol, and the like.
Examples of the ultraviolet absorber include benzotriazoles such as 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole; 2- (4,6-diphenyl-1,3,5 -Triazine type such as triazin-2-yl) -5-[(hexyl) oxy] -phenol; Benzophenone type such as octabenzone; 2,4-di-tert-butylphenyl-3,5-di-tert-butyl- Examples thereof include benzoate-based compounds such as 4-hydroxybenzoate.
Among these, the hindered amine light has a high effect of improving the weather resistance and the maximum use of the effect of the combination of the carbonate ester solvent (C) component and the naphthene-containing aliphatic hydrocarbon solvent (D) component. Stabilizers and / or hindered phenolic antioxidants are preferred. In the present invention, “and / or” means that each may be used in combination, or each may be used alone.
The weathering stabilizer is preferably blended in an amount of 0.01 to 30 parts by weight, particularly 0.1 to 10 parts by weight, based on 100 parts by weight of the isocyanate group-containing urethane prepolymer (A).

The adhesion improver is used for improving the adhesion of the curable composition. In addition to the coupling agent, an epoxy resin, a phenol resin, an alkyl titanate, an organic polyisocyanate, and the like can be given. Examples of the coupling agent include various coupling agents such as silane-based, aluminum-based, and zircoaluminate-based and / or partial hydrolysis condensates thereof. Of these, the silane-based coupling agent and / or partial hydrolysis thereof. The decomposed product is preferable because of its excellent adhesiveness.
Specific examples of the silane coupling agent include vinyltrimethoxysilane, 3- (meth) acryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, vinylmethyldimethoxy. Silane, 3- (meth) acryloxypropylmethyldimethoxysilane, N- (2-aminomethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- Molecular weight of 500 or less, preferably 400 containing alkoxysilyl groups such as (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane The following low molecular weight compounds And / or it may be a compound with a molecular weight of 200 to 3,000 with one or more partially hydrolyzed condensate of the silane-based coupling agent.
The usage-amount of an adhesive improvement agent is 0.1-30 mass parts with respect to 100 mass parts of isocyanate group containing urethane prepolymer (A), Furthermore, 0.1-5 mass parts is preferable.

The storage stability improver is blended to improve the stability of the curable composition during storage, and the storage stability improver reacts with the water present in the curable composition and dehydrates. And low molecular crosslinkable silyl group-containing compounds such as vinyltrimethoxysilane, calcium oxide, magnesium oxide, p-toluenesulfonyl isocyanate, and the like. Among these, p-toluenesulfonyl isocyanate is preferable.
The usage-amount of a storage stability improver is 0.1-30 mass parts with respect to 100 mass parts of isocyanate group containing urethane prepolymer (A), Furthermore, 0.1-5 mass parts is preferable.

  Examples of the colorant include inorganic pigments such as titanium oxide and iron oxide, organic pigments such as copper phthalocyanine, and carbon black. These can be used alone or in combination of two or more.

The plasticizer is used to lower the viscosity of the curable composition to improve workability, or to adjust the physical properties after curing, and includes dioctyl phthalate (DOP), dibutyl phthalate, phthalate Phthalate esters such as butyl benzyl acid, dioctyl adipate, diisodecyl succinate, dibutyl sebacate, butyl oleate, etc., phosphate esters such as trioctyl phosphate, tricresyl phosphate, chlorinated paraffin, etc. Low molecular weight plasticizers having a molecular weight of less than 1,000, such as halogenated aliphatic compounds; the same polyoxyalkylene polyols and polyoxyalkylene monools as mentioned in the synthesis of the isocyanate group-containing urethane prepolymer (A) Alkyl etherification or alkyl ester of the hydroxyl group of Compound blocked with, polybutadiene, polychloroprene, polyisoprene, and the like molecular weight of 1,000 or more high molecular weight plasticizer, such as olefin polymers such as hydrogenated polybutene.
However, low molecular weight plasticizers such as DOP tend to migrate (bleed) to the surface of the cured product, and therefore have the disadvantage of causing surface contamination due to adhesion of dust in the atmosphere due to adhesion of the surface. If it leaks into the environment such as water or the ocean, it is suspected of becoming an environmentally hazardous substance called endocrine disrupting substance, so-called environmental hormone, and disturbing the ecosystem. A polymeric plasticizer having a molecular weight of 1,000 or more and further having a molecular weight of 1,000 to 20,000 is preferred.
For the above reasons, it is desirable to keep the amount of plasticizer used in a small amount, preferably 100 parts by mass or less, more preferably 50 parts by mass or less, and even more preferably 100 parts by mass or less with respect to 100 parts by mass of the isocyanate group-containing urethane prepolymer (A). It is preferably 20 parts by mass or less, and most preferably 0 parts by weight.

  Curing accelerating catalysts include alkoxides of metals such as tetra-n-butyl titanate; metals such as zinc, tin, lead, zirconium, bismuth, cobalt, manganese, iron and octyl, such as stannous octylate and tin octenoate. Salts with acids, organic acids such as octenoic acid, naphthenic acid; metal chelate compounds such as dibutyltin bis (acetylacetonate), zirconium tetrakis (acetylacetonate), titanium tetrakis (acetylacetonate); dibutyltin dilaurate, dioctyl Salts of organic metals such as tin dilaurate and organic acids; triethylenediamine, triethylamine, tri-n-butylamine, hexamethylenetetramine, 1,8-diazabicyclo [5,4,0] undecene-7 (DBU), 1,4 -Diazabicyclo [2,2,2] octane (DABC ), N- methylmorpholine, tertiary amines such as N- ethylmorpholine, or a salt of these amines with organic acids. These can be used alone or in combination of two or more. Of these, a metal chelate compound or a salt of an organic metal and an organic acid is preferable, and dibutyltin dilaurate is more preferable because the effect of promoting curing is high. The usage-amount of a hardening acceleration | stimulation catalyst is 0.001-10 mass parts with respect to 100 mass parts of isocyanate group containing urethane prepolymer (A), Furthermore, 0.1-5 mass parts is preferable. If it is less than 0.001 part by mass, the effect of promoting the curing does not appear, and if it exceeds 10 parts by mass, the storage stability of the curable composition and the water resistance and heat resistance of the cured product are deteriorated.

  The method for producing the curable composition of the present invention is not particularly limited. For example, an organic isocyanate compound and an active hydrogen-containing compound are charged in a reaction vessel made of stainless steel or the like, or in the presence of a urethanization reaction catalyst. In the absence, in the presence or absence of an organic solvent, with moisture blocked under a nitrogen gas stream, etc., the reaction is carried out by heating at 50 to 120 ° C. for 0.5 to 10 hours, and contains an isocyanate group in advance. A urethane prepolymer (A) is synthesized. The obtained isocyanate group-containing urethane prepolymer (A), filler (B-1), thixotropic agent (B-2), carbonate ester solvent (C) and naphthene were separately prepared in a kneading container made of stainless steel or the like. Charge the containing aliphatic hydrocarbon solvent (D). Furthermore, when using other solvents and additives other than (B-1) and (B-2), these raw materials are charged and kneaded in a state where moisture is blocked as described above. Next, a method of producing a curable composition product by defoaming under reduced pressure, filling a paper, resin or metal cartridge, a pail can, or various bag-like containers and sealing them can be mentioned. At this time, when the isocyanate group-containing urethane prepolymer (A) is synthesized, various raw materials such as the filler (B-1) may be charged, or the filler (B-1), thixotropic agent ( B-2) After adding at least one of the solvent (C), the solvent (D), and other additives, by adding an organic isocyanate compound and an active hydrogen-containing compound therein and performing a urethanation reaction, A method of synthesizing the isocyanate group-containing urethane prepolymer (A) and obtaining a curable composition is also mentioned.

The curable composition of the present invention can be used as a one-component type according to the use, or as a two-component type using the curable composition of the present invention as a main agent and water or an amine compound as a curing agent. It is preferable to use it as a one-component moisture-curable curable composition because there is no trouble of mixing the main agent and the curing agent, and there is no inconvenience such as poor mixing and excellent workability.
In addition, examples of the use of the curable composition of the present invention include adhesives, paints, sealing materials, and the like for construction, civil engineering, and automobiles. It is preferably used as an adhesive or a sealing material, particularly as an adhesive.
In addition, the materials to which the curable composition of the present invention is applied include cement materials such as mortar and concrete, natural stone materials such as marble, ceramic materials such as siding and tiles, and various materials such as polyethylene and vinyl chloride. A sheet-like or plate-like material made of a synthetic resin, a wood-based material such as wood or plywood, and the like are preferable because of good adhesiveness.

Hereinafter, the present invention will be described in more detail with reference to examples.
Here, the one-component moisture curable adhesive is shown as an example of the curable composition, but is not limited thereto.

[Synthesis Example 1] Synthesis of Isocyanate Group-Containing Urethane Prepolymer P-1 Polyoxypropylene diol (Asahi Glass) while flowing nitrogen gas into a reaction vessel equipped with a stirrer, thermometer, nitrogen gas introduction tube and heating / cooling device. 458 g of company product, Exenol 3021, number average molecular weight 3,300), 292 g of polyoxypropylene triol (product of Mitsui Chemicals Polyurethane, Triol-MN-4000, number average molecular weight 4,000), dimethyl carbonate (DMC) And 195 g of 4,4′-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry Co., Ltd., Millionate MT, molecular weight 250) with stirring, and dibutyltin dilaurate (Nitto Kasei Co., Ltd., Neostan U-100) as 0 as a reaction catalyst. . After adding 1 g, heat to 70 Reacted at 80 ° C., an isocyanate group content has finished cooling the reaction to room temperature when it becomes less than the theoretical value (4.51 wt%) was synthesized an isocyanate group-containing urethane prepolymer P-1. The reaction time at this time was 2 hours, and the measured isocyanate group content by titration was 4.35% by mass.
The obtained isocyanate group-containing urethane prepolymer P-1 was a viscous liquid transparent at room temperature with a viscosity of 10,000 mPa · s at 25 ° C. The amount of DMC in 105 g of the urethane prepolymer P-1 is 5 g.

Example 1
While flowing nitrogen gas into a kneading vessel equipped with a stirrer, a nitrogen gas introduction pipe and a heating / cooling device, 105 g of the isocyanate group-containing urethane prepolymer P-1 obtained in Synthesis Example 1 was charged and stirred in advance, each of 100- 50 g fatty acid surface-treated calcium carbonate (Shiraishi Kogyo Co., Ltd., Shirahika Hana CCR), which has been dried in a dryer at 110 ° C. to a moisture content of 0.05% by mass or less, is charged with 145 g of heavy calcium carbonate, and a solvent. 50 g of dimethyl carbonate (DMC) and 50 g of Exol D40 (Exxon Mobil product, 50% by weight of naphthene, 0.03% by weight of aromatic) as a naphthene-containing aliphatic hydrocarbon solvent were added in order. Mix until. Next, 1 g of the following hindered phenol antioxidant, 1 g of hindered amine light stabilizer, 1 g of 3-glycidoxypropyltrimethoxysilane (manufactured by Chisso, Silaace S510) as a silane coupling agent, p -1 g of toluenesulfonyl isocyanate was added and further mixed until the contents were uniform. Subsequently, it was degassed under reduced pressure at 50 to 70 hPa, filled into a square container made of tinplate, and sealed to prepare a one-part moisture-curable adhesive (S-1) that is a viscous paste-like liquid at room temperature.
Hindered phenolic antioxidants:
Ciba Specialty Chemicals, IRGANOX 1010, pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]
Hindered amine light stabilizer:
Ciba Specialty Chemicals, CHIMASSORB 944LD,
Poly [{6- (1,1,3,3-tetramethylbutyl) amino-1,3,5-triazine-2,4-diyl} {(2,2,6,6-tetramethyl-4- Piperidyl) imino} hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl) imino}]

Example 2
In Example 1, instead of Exol D40, 50 g of Exol D30 (ExxonMobil product, 67% by weight of naphthene, 0.01% by weight of aromatic) was used as a naphthene-containing aliphatic hydrocarbon solvent, and hindered amine light A one-part moisture-curing adhesive (S-2) was prepared in the same manner except that no stabilizer was used.

Example 3
In Example 1, 37 g of DMC was used, and in place of Exol D40, Swaclean 150 (Maruzen Oil Co., a mixture of C9 and C10 alkylcyclohexane, aromatic content 1. In the same manner except that 47 g of 0% by volume or less) and 16 g of acetone were used, a one-part moisture-curing adhesive (S-3) that was viscous at room temperature was prepared.

Example 4
In Example 3, 14 g of DMC and 70 g of Swaclean 150 were used, except that a hindered phenolic antioxidant was not used. S-4) was prepared.

Comparative Example 1
In Example 1, a one-part moisture-curing adhesive (Comparative S-1) that was viscous at room temperature was prepared in the same manner except that 100 g of DMC was used and Exol D40 was not used.

Comparative Example 2
In Example 2, a one-part moisture-curing adhesive (Comparative S-2) that was viscous at room temperature was prepared in the same manner except that 50 g of toluene was used instead of Exol D30. .

Comparative Example 3
In Example 3, a one-part moisture-curing adhesive (Comparative S-3) that was viscous at room temperature was prepared in the same manner except that 84 g of DMC was used and SWACLEAN 150 was not used.

Comparative Example 4
In Example 4, a one-part moisture-curing adhesive (Comparative S-4) that is viscous at room temperature was prepared in the same manner except that 70 g of toluene was used instead of Swclean 150. did.

（２）粘度
ＪＩＳ Ｋ ７１１７−１（１９９９）「プラスチック−液状、乳濁状又は分散状の樹脂−ブルックフィールド形回転粘度計による見掛け粘度の測定方法」および付属書１により、ＳＢ形回転粘度計を使用し、試験温度２５℃における接着剤の粘度を測定した。
なお、スピンドルはＳＢ４号を使用し、回転数６ｒｐｍまたは１２ｒｐｍで測定した。
（３）はく離接着強さ
ＪＩＳ Ａ ５５３６（２００３年）、「床仕上げ材用接着剤」の５．３．３はく離接着強さにより、９０度はく離接着試験を行い、はく離接着強さが２０Ｎ／２５ｍｍ以上のものを○と評価した。
なお、下地材としてフレキシル板、試験用床材としてＪＩＳ Ａ ５７０５に規定する市販のビニル床シートを用い、下地材に接着剤を塗布後約２０分経過後、ビニル床シートを貼り付け、４８時間養生後引張試験をした。 Using the one-component moisture curable adhesives (S-1) to (S-4) and (Comparative S-1) to (Comparative S-4) obtained in Examples 1 to 4 and Comparative Examples 1 to 4 The results of testing by the test methods described below are shown in Tables 1 and 2 together with the composition.
Also, the amount of DMC in the urethane prepolymer P-1, the amount of DMC in the solvent (in the adhesive), the amount of naphthene in the solvent (in the adhesive) (also referred to as naphthene), the ratio of naphthene to DMC Tables 1 and 2 show the results obtained by calculation based on the blending composition and the composition of the raw materials with respect to the amount of aromatic hydrocarbon (also referred to as aromatic component) in the solvent.
〔Test method〕
(1) Content of aromatic content in adhesive The content of aromatic content in the adhesive obtained in Examples and Comparative Examples was calculated by the following formula based on the calculation results in Tables 1 and 2.
In addition, although the aromatic content of the Swaclean 150 used in Examples 3 and 4 is volume%, since the content is small, it may be approximated to mass%.

(2) Viscosity JIS K 7117-1 (1999) “Plastic-Liquid, emulsion or dispersion resin-Method of measuring apparent viscosity with Brookfield type rotational viscometer” and Appendix 1 SB type rotational viscometer And the viscosity of the adhesive at a test temperature of 25 ° C. was measured.
In addition, SB4 was used for the spindle, and the measurement was performed at a rotational speed of 6 rpm or 12 rpm.
(3) Peeling adhesion strength JIS A 5536 (2003), “Adhesive for floor finish”, 5.3.3 Peeling adhesion strength, 90 degree peeling adhesion test was conducted. The thing of 25 mm or more was evaluated as (circle).
In addition, a flexible vinyl plate is used as the base material, and a commercially available vinyl floor sheet specified in JIS A 5705 is used as the test floor material. After about 20 minutes have passed since the adhesive was applied to the base material, the vinyl floor sheet was pasted for 48 hours. A tensile test was conducted after curing.

Claims (10)

  Curability characterized by containing an isocyanate group-containing urethane prepolymer (A), a filler (B-1), a carbonate solvent (C), and a naphthene-containing aliphatic hydrocarbon solvent (D). Composition.   It contains an isocyanate group-containing urethane prepolymer (A), a thixotropic agent (B-2), a carbonate solvent (C), and a naphthene-containing aliphatic hydrocarbon solvent (D). Curable composition.   Isocyanate group-containing urethane prepolymer (A), filler (B-1), thixotropic agent (B-2), carbonate solvent (C), naphthene-containing aliphatic hydrocarbon solvent (D), A curable composition comprising:   The curable composition according to claim 1 or 3, wherein the filler (B-1) is calcium carbonate.   The curable composition according to claim 2 or 3, wherein the thixotropic agent (B-2) is a fatty acid surface-treated calcium carbonate.   The curable composition according to any one of claims 1 to 5, wherein the carbonate ester solvent (C) is dimethyl carbonate.   The naphthene content in the naphthene-containing aliphatic hydrocarbon solvent (D) is 20 to 100% by mass, and the aromatic content is 1% by mass or less. The curable composition according to 1.   Furthermore, the curable composition as described in any one of Claims 1-7 which mix | blends additives (E) other than a filler (B-1) and a thixotropic imparting agent (B-2).   The curable composition according to claim 8, wherein the additive (E) is a hindered amine light stabilizer and / or a hindered phenol antioxidant.   The curable composition as described in any one of Claims 1-9 whose content of the aromatic content of the said curable composition is 1 mass% or less.