JP2005306921A - Method for improving topcoating material adhesiveness and urethane-based sealant composition suitable for topcoating specification - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for improving the coating film adhesiveness of a coating material top-coated on the surface of a cured product and further the water-resistant adhesiveness of a topcoating film without relating to the curing period of a curing composition containing an isocyanate group-containing urethane prepolymer, and to obtain a urethane-based sealant composition suitable for topcoating specifications having improved topcoating adhesiveness. <P>SOLUTION: The method for improving the adhesiveness of the topcoating material comprises adding an oxygen-curable unsaturated compound, such as a compound having an oxygen-curable unsaturated group and a polar group in the molecule, and further one or more compounds selected from the group consisting of drying oils and their modified products, to the isocyanate group-containing urethane prepolymer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for improving the topcoat paint adhesion of a curable composition comprising an isocyanate group-containing urethane prepolymer, and a curable composition suitable for topcoat specifications with improved topcoat paint adhesion. .

  Conventionally, urethane-based curable compositions using polyurethane resin as a curable resin component as a curable composition for waterproof sealants, adhesives, paints, etc. for buildings, civil engineering, automobiles, etc. Widely used because of its excellent adhesion after curing. When this urethane-based curable composition is used in the field of construction or civil engineering, for example, as an adhesive, paint or waterproof sealant on the outer wall surface or outer wall joint of a building, or as a waterproof paint or inter-board joint for civil engineering structures. When used as a waterproof sealant, after applying, filling and curing, for the purpose of giving design properties such as making the appearance beautiful or giving a specific image, or for the purpose of enhancing durability, In addition, there are many cases where specifications for top coating are applied, in which case it is necessary that the coating film adhesion (coating film adhesion) of the top coating to the cured surface is good and that the coating does not peel off over time. Become.

  The urethane-based curable composition uses an isocyanate group-containing urethane prepolymer as a curable resin component, and the urethane group reacts with moisture (humidity) in the atmosphere to crosslink and cure. Therefore, it can be used as a one-component moisture-curable composition, and there is no need to mix the main agent and curing agent as in the two-component type, and there is no mixing failure or poor curing due to measurement errors, so it is safe even for non-skilled workers. It is suitable for use because of its excellent workability and its usage is increasing year by year.

When adopting the specifications for overcoating the paint as described above, the curable composition containing this isocyanate group-containing urethane prepolymer is applied to and filled in the object as described above, and after a short period of 3 to 3 After a curing curing period of about 7 days or 2 weeks to 1 month at the longest, various top coats are applied to the surface of the cured product. In particular, there is a problem that the adhesion of water-based paints whose use amount is increasing due to the recent increase in environmental protection, and there is a strong demand for improving the adhesion of the top coat film.
In addition, building outer walls and civil engineering structures are frequently exposed to rainwater and other water for many years, so that the overcoated film does not peel off when exposed to water, that is, the water-resistant adhesion of the film. Must be good.

Now, polyisocyanate compositions comprising an isocyanate-terminated prepolymer derived from a specific diisocyanate monomer and an unsaturated compound capable of reacting with oxygen have been proposed. This composition is excellent in weather resistance, and in particular, excellent in stain resistance, but how the adhesion of the top coating can be improved when the top coating is applied to the surface after curing. Has no disclosure. (For example, see Patent Document 1)
Moreover, the curable composition which consists of an unsaturated compound which can react with a photocurable substance and oxygen in the air for a urethane prepolymer is proposed. This composition has been shown to improve cracking due to weathering deterioration and to improve stain resistance or dirt on the surface of the cured product due to adhesion of dust, etc., but how it can improve the adhesion of the top coat. It is not described at all. (For example, see Patent Document 2)
As described above, there is still no excellent method for improving the adhesion of the top coating material to the surface after curing of the curable composition, and it has been demanded to improve such adhesion.

JP 07-166147 A Japanese Patent Laid-Open No. 05-163477

  The invention of the present application relates to the coating film adhesion of the coating applied to the cured product surface after curing, even if the curing curing period of the curable composition containing the isocyanate group-containing urethane prepolymer is short or long, and further the top coating film An object of the present invention is to provide a urethane-based sealing material composition suitable for the method of improving the water-resistant adhesion of the coating composition and for the topcoat coating specification with improved adhesion of the topcoat paint.

  As a result of intensive studies in view of the above-mentioned conventional problems, the present inventors have surprisingly found that when an oxygen curable unsaturated compound is blended with an isocyanate group-containing urethane prepolymer, the adhesion of the coating film of the top coating, and further the coating The present inventors have found that the water-resistant adhesion of the film is remarkably improved and have arrived at the present invention. That is, the present invention is directed to a method for improving the adhesion of a top coating by adding an oxygen curable unsaturated compound to an isocyanate group-containing urethane prepolymer and a top coating specification for improving the coating adhesion of the top coating. The present invention relates to a urethane-based sealant composition suitable for use in the manufacturing process.

  More specifically, the present invention is a method for improving the adhesion of a top coating material by adding an oxygen curable unsaturated compound to a curable composition comprising an isocyanate group-containing urethane prepolymer, wherein Examples of the unsaturated compound include compounds containing an oxygen-curable unsaturated group and a polar group in the molecule, and further include one or more compounds selected from the group consisting of drying oils and modified products thereof. . Further, an additive such as a dilution resin may be further added to the one having improved adhesion of the top coat. Moreover, this invention relates to the urethane type sealing material composition suitable for top-coat coating specifications characterized by containing an isocyanate group containing urethane prepolymer and an oxygen curable unsaturated compound.

  By taking such a configuration, the curable composition comprising an isocyanate group-containing urethane prepolymer has a workability at the time of filling and coating, rubber elastic properties such as tensile stress and elongation after curing, adhesiveness, heat resistance, Not only the water resistance is good, but especially when a top coat is applied to the surface of the cured product, not only the adhesion between the paint film and the cured product surface is improved, but also the water resistance of the coating film. This is an excellent effect that is greatly improved.

  Below, the component used by this invention is demonstrated.

  The isocyanate group-containing urethane prepolymer is one in which an isocyanate group reacts with moisture (humidity) in the air, forms a urea bond, crosslinks and cures, and is contained in the curable composition of the present invention as a curing component. Yes, it is obtained by reacting an organic isocyanate and an active hydrogen-containing compound with active hydrogen (group) under an excess of isocyanate groups.

  Examples of the organic isocyanate include an organic polyisocyanate and, optionally, an organic monoisocyanate. Specific examples of the organic polyisocyanate include phenylene diisocyanate, diphenyl diisocyanate, naphthalene diisocyanate, and 4,4′-diphenylmethane. Diisocyanate such as diisocyanate, 2,4'-diphenylmethane diisocyanate (MDI), toluene diisocyanate (TDI) such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, aromatic such as diphenyl ether diisocyanate Aroaliphatic diisocyanates such as diisocyanate and xylylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, propylene Aliphatic diisocyanates such as diisocyanate and butylene diisocyanate, cyclohexane diisocyanate, methylenebis (cyclohexyl isocyanate), alicyclic diisocyanates such as isophorone diisocyanate, and carbodiimide modified products, biuret modified products, allophanate modified products, dimers, and dimers of these diisocyanates. Examples thereof include a polymer, polymethylene polyphenyl polyisocyanate (crude MDI, polymeric MDI) and the like, and these can be used alone or in combination of two or more. In some cases, for modification of an isocyanate group-containing urethane prepolymer, n-butyl monoisocyanate, n-hexyl monoisocyanate, n-hexadecyl monoisocyanate, n-octadecyl monoisocyanate, p-isopropylphenyl monoisocyanate, p- Organic monoisocyanates such as benzyloxyphenyl monoisocyanate can also be used. Of these, organic polyisocyanates are preferable from the viewpoint of excellent tensile adhesiveness and water resistance after curing, aromatic diisocyanates and araliphatic diisocyanates are more preferable, and MDIs are more preferable, especially 4,4. '-Diphenylmethane diisocyanate is preferred.

  As the active hydrogen-containing compound, in addition to a polymer polyol or polymer polyamine, a low molecular polyol, a low molecular amino alcohol, a low molecular polyamine, or a modification of an isocyanate group-containing urethane prepolymer as a chain extender used in some cases. Examples thereof include a high molecular weight polymer and a low molecular weight monool.

Examples of the polymer polyol include polyester polyol, polycarbonate polyol, polyoxyalkylene polyol, hydrocarbon polyol, poly (meth) acrylate polyol, animal and plant polyol, these copolyols, or a mixture of two or more of these. Etc.
The number average molecular weight of the polymer polyol is 500 or more, 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 500, 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 becomes too high, Since workability deteriorates, it is not preferable.

Examples of 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, triphthalic acid, and the like. One or more of polycarboxylic acids such as merit acid, acid esters, or acid anhydrides, 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, diethylene glycol, dipropylene glycol, 1 , 4-cyclohexanedimethanol, ethylene oxide or propylene oxide adduct of bisphenol A, low molecular polyols such as trimethylolpropane, glycerin, pentaerythritol, butylenediamine, hexamethylenediamine, xylylenediamine, isophoronediamine, etc. Examples thereof include polyester polyols or polyester amide polyols obtained by a dehydration condensation reaction with one or more low molecular amino alcohols such as low molecular polyamines, monoethanolamine, and diethanolamine.
Also, for example, lactone polyesters 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. A polyol is mentioned.

  Examples of the polycarbonate polyol include dehydrochlorination reaction of low molecular polyols and phosgene used for the synthesis of the above-described polyester polyol, or esters of the low molecular polyols with diethylene carbonate, dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and the like. What is obtained by an exchange reaction is mentioned.

Examples of the polyoxyalkylene polyol include low molecular polyols, low molecular polyamines, low molecular amino alcohols, polycarboxylic acids, sorbitol, mannitol, sucrose used for the synthesis of the above-described polyester polyols. 1 or more of cyclic ether compounds such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using one or more of low molecular weight polyhydric alcohols such as saccharides such as glucose and low molecular weight polyphenols such as bisphenol A and bisphenol F as initiators A polyoxyethylene-based polyol, a polyoxypropylene-based polyol, a polyoxybutylene-based polyol, a polyoxyethylene, which is obtained by ring-opening addition polymerization or copolymerization (hereinafter, “polymerization or copolymerization” is referred to as (co) polymerization). Ramechiren polyols, poly - (oxyethylene) - (oxypropylene) - random or block copolymer 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 organic isocyanate react by hydroxyl group excess with respect to an isocyanate group, and made the molecular terminal a hydroxyl group is also mentioned.
The number of average 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 Having a narrow 1.3, viscosity of the resulting diisocyanate sulfonate group-containing urethane prepolymer can reduce, and rubber elasticity properties after curing of the resulting cured composition is preferable in that is good.

In addition, for modification of an isocyanate group-containing urethane prepolymer, polyoxyl obtained by ring-opening addition polymerization of a cyclic ether compound such as propylene oxide using a low-molecular monoalcohol such as methyl alcohol, ethyl alcohol or propyl alcohol as an initiator. In some cases, polyoxyalkylene monools such as propylene monools may be used.
The “system” such as the polyoxyalkylene-based polyol or polyoxyalkylene-based monool is 50% by mass or more, further 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 the hydrocarbon polyol include polyolefin polyols such as polybutadiene polyol and polyisoprene polyol, polyalkylene polyols such as hydrogenated polybutadiene polyol and hydrogenated polyisoprene polyol, halogenated poly such as chlorinated polypropylene polyol and chlorinated polyethylene polyol. Examples include alkylene polyols.

  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 those copolymerized in the presence or absence of.

  Examples of animal and plant-based polyols include castor oil-based diols.

As the chain extender, in addition to the low molecular weight polyols, polyamines and amino alcohols used in the synthesis of the polyester polyol, the polyoxyalkylene polyol described above has a low molecular weight with a number average molecular weight of less than 500, Or the mixture of these 2 or more types is illustrated.
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.

  The isocyanate group-containing urethane prepolymer in the present invention can be synthesized by either a batch charge reaction method or a multistage charge reaction method, but it is necessary to leave an isocyanate group in the molecule of the prepolymer. The isocyanate group / active hydrogen (group) equivalent ratio of the isocyanate group of the organic isocyanate and the polymer polyol and optionally the active hydrogen (group) of the active hydrogen-containing compound such as a chain extender is 1.1 to 5.0. /1.0 is preferable, and 1.3 to 2.0 / 1.0 is more preferable. The isocyanate group-containing urethane prepolymer thus obtained preferably has an isocyanate group content of 0.1 to 15.0% by mass, particularly preferably 0.3 to 10.0% by mass, and most preferably 0.4 to 5.0% by mass. When the isocyanate group content is less than 0.1% by mass, the molecular weight becomes too large, the viscosity increases, and the workability decreases. Moreover, since there are few crosslinking points in a prepolymer, sufficient adhesiveness cannot be obtained. When the isocyanate group content exceeds 15.0% by mass, it is difficult to prevent foaming due to carbon dioxide gas generated by the reaction of the isocyanate group with moisture, such being undesirable.

  In synthesizing the isocyanate group-containing urethane prepolymer in the present invention, a known catalyst similar to the compound mentioned as the curing acceleration catalyst described later can be used as the urethanization catalyst. Among these, metal organic acid salts and salts of organic metals and organic acids are preferable, and dibutyltin dilaurate is particularly preferable. Furthermore, a known organic solvent can be used.

  Next, the oxygen curable unsaturated compound will be described.

An oxygen curable unsaturated compound is a compound having in its molecule an unsaturated group that reacts and cures with oxygen, such as in the air. By adding it to the curable composition, the surface after curing of the curable composition When the top coat is applied to the surface, the effect of remarkably improving the adhesion of the paint is exhibited. This is presumably because the oxygen curable unsaturated compound migrates to the surface of the cured product to form a thin cured film, and this film and the coating film of the overcoated paint are strongly bonded.
Specific examples of the oxygen curable unsaturated compound include oxygen-cured in the molecule such as drying oil, various modified products of drying oil, (co) polymer maleic acid modified product of diene compound, and boiled oil modified product. Compounds having an oxygen-curable unsaturated group in the molecule, such as a compound containing a polar unsaturated group and a polar group such as an ester group, or a (co) polymer of a diene compound, etc. Can be mentioned.

  Examples of drying oil (including semi-drying oil in a broad sense) include paulownia oil, soybean oil, linseed oil, dehydrated castor oil, coconut oil, castor oil, and the like. Examples thereof include various alkyd resins obtained, (meth) acrylic (co) polymers modified with drying oil, epoxy resins, and silicone resins.

Examples of (co) polymers of diene compounds include polymers of C _{4 to} C ₈ diene compounds such as 1,2-butadiene, 1,4-butadiene, 1,3-pentadiene, isoprene, chloroprene, and the like. Examples of the above-mentioned copolymers, or copolymers of these with other monomers such as styrene and acrylonitrile (SBR, NBR, etc.) and the like, as modified products of (co) polymers of diene compounds, Examples thereof include maleated products, boiled products, and epoxidized products of (co) polymers of the diene compounds, and among these, (co) polymers that are liquid at room temperature are preferred.
These can be used alone or in combination of two or more.
Among these, when blended in the curable composition, a compound containing an oxygen curable unsaturated group and a polar group such as an ester group in the molecule is a great effect of improving the adhesion of the top coating material. Preferably, one or more selected from the group of drying oils and modified products of drying oils are preferred, more preferred are drying oils, and most preferred are tung oils.

  The oxygen curable unsaturated compound can be used in combination with a catalyst or a metal dryer that promotes the oxidative curing reaction. Examples of these catalysts and metal dryers include salts of metals and organic acids such as cobalt naphthenate, lead naphthenate, zirconium naphthenate, cobalt octylate and zirconium octylate, and amine compounds.

  The oxygen curable unsaturated compound is preferably used in an amount of 0.01 to 50 parts by weight, more preferably 0.1 to 20 parts by weight, particularly 1 to 20 parts by weight, based on 100 parts by weight of the isocyanate group-containing urethane prepolymer. If it is less than 0.01 part by weight, the adhesiveness of the top coat is not sufficiently improved, and if it exceeds 50 parts by weight, the tensile properties of the cured product tend to be impaired.

  Next, the additive further used in the curable composition in the adhesion improving method of the present invention will be described.

  Examples of additives in the present invention include dilution resins, weathering stabilizers, thixotropic agents, fillers, adhesion promoters, storage stability improvers (dehydrating agents), colorants, and the like.

  The dilution resin in the present invention is used to dilute the curable composition to lower the viscosity, improve workability, and adjust the elastic properties of rubber such as modulus and elongation after curing. Preferred examples include low viscosity resin compounds having an average molecular weight of 500 or more and having or not having a polar group in the molecule. Examples of the polar group include an ester group, an ether group (oxyalkylene group), a urethane group, and the like and the number and the number of these groups may be included in the molecule alone or in combination. Also good. Furthermore, the dilution resin is preferably a compound that has substantially no hydroxyl group or isocyanate group in the molecule.

  Specific examples of the dilution resin include, for example, a resin having a polar group, a polyester resin from dicarboxylic acids and glycols, and an alkyl etherification of a polyoxyalkylene glycol such as polyoxyethylene glycol or polyoxypropylene glycol. Derivatives, alkyl esterified derivatives, saccharide polyhydric alcohol polyether resins, polyoxyalkylene resins such as liquid polyoxyalkylene urethane resins, low viscosity acrylic acid and methacrylic acid alkyl ester (co) polymer resins Etc. Hereinafter, in the present invention, “acrylic acid or methacrylic acid” is referred to as “(meth) acrylic acid”. Examples of the resin having no polar group include hydrocarbon resins such as polyolefin resins such as polybutadiene and polyisoprene, and polyalkylene resins such as hydrogenated polybutadiene and hydrogenated polyisoprene.

  These can be used alone or in combination of two or more. Among these, a saccharide-based polyhydric alcohol polyether resin, a liquid polyoxy compound, having low viscosity, good compatibility with an isocyanate group-containing urethane prepolymer, and good workability of the resulting curable composition. Alkylene-based urethane resins and low-viscosity (meth) acrylic acid alkyl ester-based (co) polymer resins are preferred, particularly liquid polyoxyalkylene-based urethane resins and low-viscosity (meth) acrylic acid alkyl ester-based (co) polymer resins. Resins are preferred.

  The number average molecular weight of the dilution resin is 500 or more, further 1,000 to 100,000, more preferably 2,000 to 50,000, particularly preferably 2,000 to 20,000, and 2,000 to 10,000. Is most preferred. If the number average molecular weight is less than 500, it tends to migrate (bleed) to the surface of the cured product, lowers the adhesion of the overcoated film, and further migrates to the surface of the coated film to adhere the surface of the coated film. This is not preferable because contamination due to adhesion occurs. When the number average molecular weight exceeds 100,000, the viscosity of the dilution resin is increased, and the workability of the resulting curable composition is deteriorated.

  As the polyether-based (polyoxyalkylenated) resin of the saccharide polyhydric alcohol, ethylene oxide, propylene oxide or the like can be used with respect to the hydroxyl group of the saccharide polyhydric alcohol such as sucrose (sucrose), glucose, mannitol, sorbitol. Examples include addition (co) polymerization of alkylene oxide, further alkyl etherification or alkyl esterification, and capping the ends with alkyl groups, and resins having substantially no hydroxyl groups in the molecule. As a general commercial product of the polyether resin, SPX-80 manufactured by Sanyo Chemical Industries, Ltd. can be mentioned.

  The liquid polyoxyalkylene urethane resin contains a polyoxyalkylene group and a urethane group in the molecule obtained by reacting a polyoxyalkylene alcohol and an organic isocyanate, and has substantially a hydroxyl group or an isocyanate group. High molecular weight resins are preferred. By making the molecular maximum distribution (Mw / Mn) of the liquid polyoxyalkylene urethane resin 1.6 or less, particularly preferably as narrow as 1.0 to 1.3, the wavy polyoxyalkylene urethane resin can be obtained. Even if it is high molecular weight, a viscosity can be restrained low and workability | operativity of the curable composition obtained can be made favorable.

Specifically, a polyoxyalkylene alcohol and an organic isocyanate (preferably a polyoxyalkylene monool and an organic isocyanate, or a polyoxyalkylene polyol and an organic monoisocyanate) have an isocyanate group / hydroxyl group equivalent ratio. In the range of 0.9 to 1.1 / 1.0, the reaction can be preferably carried out by preferably reacting 1/1. If the equivalent ratio is less than 0.9 / 1.0, the maximum content of hydroxyl groups increases, so that it reacts with the isocyanate groups of the isocyanate group-containing urethane prepolymer to increase the viscosity and deteriorate the workability. If it exceeds 0, the content of isocyanate groups increases, which is not preferable because the influence of the cured product on the rubber elastic properties cannot be ignored.
The above-mentioned “substantially free of hydroxyl group or isocyanate group in the molecule” means that when synthesizing a polyether-based resin of saccharide-based polyhydric alcohol or a liquid polyoxyalkylene-based urethane resin, it depends on the molar ratio of raw materials. Although a small amount of hydroxyl group or isocyanate group may remain in the molecule, this means that there is no inconvenience even if it is assumed that no hydroxyl group or isocyanate group is contained in achieving the present invention.

Specific examples of the polyoxyalkylene alcohol include polyoxyalkylene monools, polyoxyalkylene polyols, and mixtures thereof.
Examples of the polyoxyalkylene monool include those obtained by ring-opening addition (co) polymerization of a cyclic ether compound to an initiator. The number average molecular weight of the polyoxyalkylene monool is preferably 500 to 50,000, more preferably 1,000 to 30,000, and particularly preferably 1,000 to 10,000. If the number average molecular weight is less than 500, the resulting liquid polyoxyalkylene urethane resin is likely to bleed. If the number average molecular weight exceeds 50,000, the viscosity of the liquid polyoxyalkylene urethane resin increases, and the workability of the curable composition increases. Since it gets worse, it is not preferable.

  Specific examples of the initiator include low-molecular alkyl monoalcohols such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, tert-butanol, cyclohexanol, phenol, cresol and the like. Phenols, and mixtures of two or more of these. Of these, low molecular alkyl monoalcohols having 5 or less carbon atoms such as methanol and ethanol are preferred.

  Examples of the cyclic ether compound include ethylene oxide, propylene oxide, butylene oxide, tetrahydrofuran, and a mixture of two or more thereof. Of these, propylene oxide is preferred.

  Furthermore, the polyoxyalkylene monool is produced using the same catalyst as mentioned as the catalyst used in the production of the polyoxyalkylene polyol used in the synthesis of the isocyanate group-containing urethane prepolymer. The total degree of unsaturation is 0.1 meq / g or less, more preferably 0.07 meq / g or less, and particularly preferably 0.04 meq / g or less. Molecular weight distribution [weight average molecular weight in terms of polystyrene by gel permeation chromatography (GPC) The ratio of (Mw) to number average molecular weight (Mn) = Mw / Mn] is 1.6 or less, particularly a narrow one of 1.0 to 1.3 lowers the viscosity of the resulting liquid polyoxyalkylene urethane resin. It is preferable in that the workability of the resulting curable composition is improved.

The “system” of the polyoxyalkylene monool is 50% by mass or more of the portion excluding the hydroxyl group in 1 mol of the molecule, more preferably 80% by mass or more, particularly preferably 90% by mass or more. Means that the remaining part may be modified with ester, urethane, polycarbonate, polyamide, poly (meth) acrylate, polyolefin, etc., but 95% by mass or more of the molecule excluding the hydroxyl group Is most preferably composed of polyoxyalkylene.
Examples of the polyoxyalkylene polyol include the same compounds as those used in the synthesis of the isocyanate group-containing urethane prepolymer.
These can be used alone or in combination of two or more. Of these, the polyoxyalkylene monool is preferred, and the polyoxypropylene monool is particularly preferred because the viscosity of the liquid polyoxyalkylene urethane resin obtained can be lowered and the workability of the resulting curable composition is improved. Is preferred.

Specific examples of the organic isocyanate include organic monoisocyanates, organic polyisocyanates, and mixtures thereof. Furthermore, the same compounds as those used for the synthesis of the isocyanate group-containing urethane prepolymer can be mentioned. .
These can be used alone or in combination of two or more. Of these, organic polyisocyanates are preferred in that the viscosity of the liquid polyoxyalkylene-based urethane resin obtained at a relatively low cost can be reduced, and the workability of the resulting curable composition is favorable. Alicyclic polyisocyanates and araliphatic polyisocyanates are preferred, araliphatic polyisocyanates are more preferred, xylylene diisocyanates are more preferred, and m-xylylene diisocyanate is most preferred.
In synthesizing the liquid polyoxyalkylene urethane resin, a compound similar to the effect promoting catalyst described later can be used as a reaction catalyst. Furthermore, a well-known organic solvent can also be used.

As the low-viscosity (meth) acrylic acid alkyl ester-based (co) polymer resin, specifically, a (meth) acrylic acid alkyl ester-based monomer and, if necessary, other ethylenically unsaturated compounds In the presence or absence of a polymerization initiator and in the presence or absence of an organic solvent at 50 to 350 ° C. by a known radical polymerization reaction such as batch or continuous polymerization (co-polymerization). ) A polymer resin, preferably a (co) polymer resin having a narrow molecular weight distribution and a low viscosity, which is obtained by a high temperature continuous polymerization reaction at 100 to 300 ° C., and has substantially no hydroxyl group or isocyanate group. .
The (meth) acrylic acid alkyl ester-based (co) polymer resin has a polystyrene-reduced number average molecular weight of 500 to 50,000, more preferably 800 to 10,000, particularly 800 to 5,000, by gel permeation chromatography. Tg is preferably 0 ° C. or less, more preferably −100 to −20 ° C., and a viscosity at 25 ° C. of 50,000 mPa · s or less, more preferably 100 to 10,000 mPa · s, and particularly preferably 200 to 5,000 mPa · s. If the number average molecular weight is less than 500, it is not preferable because it tends to bleed on the surface of the cured product and deteriorates the adhesion of the top coat, and the number average molecular star is 50,000, Tg is 0 ° C., viscosity Is more than 50,000 mPa · s, the workability of the curable composition is deteriorated.

  The (meth) acrylic acid alkyl ester (co) polymer resin may be obtained by polymerizing a (meth) acrylic acid alkyl ester monomer alone, or a (meth) acrylic acid alkyl ester monomer. Two or more kinds of the copolymer may be copolymerized, or a (meth) acrylic acid alkyl ester monomer and another ethylenically unsaturated compound may be copolymerized. Of these, (meth) acrylic acid alkyl ester copolymer resins are preferred because the resulting resin has a low viscosity.

  Examples of the (meth) acrylic acid alkyl ester monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and (meth) acrylic acid. Isobutyl, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, isodecyl (meth) acrylate, stearyl (meth) acrylate, (meth) acrylic Cyclohexyl acid, cetyl (meth) acrylate, behenyl (meth) acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, ethoxylated phenol (meth) acrylate, ethoxylated paracumylphenol (meth) acrylate, ethoxylated Nonylphenol (meth) a Mono (meth) acrylic acid esters such as relate, propoxylated nonylphenol (meth) acrylate, methoxydiethylene glycol (meth) acrylate, ethoxydiethylene glycol (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, 2-phenoxy (meth) acrylate, etc. , Ethoxylated bisphenol F di (meth) acrylate, ethoxylated bisphenol A di (meth) acrylate, tripropylene glycol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, caprolactone di (meth) acrylate , Neopentyl glycol di (meth) acrylate, 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, ethylene glycol Cold di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, propoxylated neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, Poly (meth) acrylic acid ester monomers such as polypropylene glycol di (meth) acrylate, etc. can be used, and these can be used alone or in combination of two or more. Among them, low viscosity dilution resin In view of the above, a low molecular weight mono (meth) acrylic acid alkyl ester monomer having a molecular weight of less than 500 and a molecular weight of less than 300 is preferable, methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylic acid. Propyl, ( More preferred are butyl (meth) acrylate and 2-ethylhexyl (meth) acrylate.

  Examples of the ethylenically unsaturated monomer other than the (meth) acrylic acid ester monomer that can be used as needed include, for example, ethylene, propylene, isobutylene, butadiene, chloroprene, vinyl chloride, and vinylidene chloride. , Vinyl acetate, acrylonitrile, styrene, chlorostyrene, 2-methylstyrene, divinylbenzene, (meth) acrylamide, N-vinyl-pyrrolidone, etc., and these can be used alone or in combination of two or more. Of these, styrene is preferred in the same manner as described above.

  The dilution resin is preferably added in an amount of 1 to 200 parts by weight, particularly 10 to 100 parts by weight, based on 100 parts by weight of the isocyanate group-containing urethane prepolymer. If it is less than 1 part by weight, the effect of reducing the viscosity with respect to the cured composition is lost, and if it exceeds 200 parts by weight, durability such as heat resistance and water resistance of the cured product is lowered, which is not preferable.

  The weather stabilizer is used to prevent oxidation, light degradation, and thermal degradation of the cured product and further improve not only the weather resistance but also the heat resistance. Specific examples of the weather stabilizer include an antioxidant and an ultraviolet absorber.

  Antioxidants include hindered amine and hindered phenol antioxidants. Examples of hindered amine antioxidants include bis (2,2,6,6-tetramethyl-4-piperidyl) sebacate and 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-tetramethylpiperidine, trade names ADK STAB series LA-52, LA-57, LA-62, LA manufactured by Asahi Denka Kogyo Co., Ltd. -67, LA-77, LA-82, LA-87 and other low molecular weight hindered amine antioxidants with a molecular weight of less than 1,000, LA-63P, LA-68D, or Ciba Specialty Chemicals of the ADK STAB series Examples thereof include hindered amine-based antioxidants having a molecular weight of 1,000 or more, such as 119FL, 2020FDL, 944FD, and 944LD of the trade name CHIMASSORB series manufactured by the company.

  Examples of the hindered phenol antioxidant include 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-hydroxyphenylpropioamide], benzenepropane Examples include acid 3,5-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 benzotriazole-based ultraviolet absorbers such as 2- (3,5-di-tert-butyl-2-hydroxyphenyl) -5-chlorobenzotriazole, and 2- (4,6-diphenyl- 1,3,5-triazin-2-yl) -5-[(hexyl) oxy] -phenol and other triazine-based UV absorbers, benzophenone-based UV absorbers such as octabenzone, 2,4-di-tert-butyl Examples thereof include benzoate ultraviolet absorbers such as phenyl-3,5-di-tert-butyl-4-hydroxybenzoate.
These weather stabilizers can be used alone or in combination of two or more.

  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, per 100 parts by weight of the isocyanate group-containing urethane prepolymer.

  The thixotropic agent is used to impart thixotropic properties to the curable composition of the present invention so as not to cause sagging (slump) when the composition is filled or applied to a vertical surface such as a building outer wall. Furthermore, this is an extremely important requirement when the curable composition is used as a sealing material. For example, inorganic thixotropic agents such as finely divided silica and organic surface treated calcium carbonate Organic thixotropic agents such as organic bentonite and fatty acid amide can be used, and one or more of these can be selected and added as appropriate. Of these, finely divided silica is preferable because it can impart thixotropy with a small amount of blending, but if a curing accelerating catalyst described later is used in order to increase the curing rate of the curable composition, the thixotropic structure is destroyed and the vertical plane is destroyed. However, organic surface-treated calcium carbonate does not have these disadvantages and gives stable thixotropic properties to the curable composition. This is particularly preferable.

  In this invention, the usage-amount of the said thixotropic agent is 1-200 weight part with respect to 100 weight part of isocyanate group containing urethane prepolymers, Furthermore, 5-150 weight part is preferable. If the amount is less than 1 part by weight, the thixotropic effect is lost, and if it exceeds 200 parts by weight, the viscosity of the resulting curable composition increases and workability deteriorates, which is not preferable.

Examples of the finely divided silica include natural silica obtained by pulverizing quartz, silica sand, diatomaceous earth, etc., and wet method silica such as sedimentation method silica, and dry method silica such as fumed silica. Silica etc. are mentioned. Further, the properties of the silica particle surface include a hydrophilic property that is not treated with an organic substance and a hydrophobic property obtained by treating the particle surface with an organic silane compound such as dimethyldichlorosilane. The size of the particles is preferably a so-called colloidal colloid having an average (primary) particle size of 1 to 1,000 nm, more preferably 1 to 100 nm, and particularly 5 to 50 nm, from the viewpoint of great thixotropic effect. The BET specific surface area (m ² / g) is 0.1 or more, more preferably 20 to 500, and particularly preferably 40 to 500.
Of these, synthetic colloidal silica and hydrophilic colloidal silica are preferred because of their great thixotropic effect.

  Examples of the organic surface-treated calcium carbonate include, for example, the surface of heavy calcium carbonate obtained by pulverizing natural calcium carbonate into fine powder, such as finely powdered synthetic calcium carbonate called precipitated calcium carbonate or light calcium carbonate, For the purpose of imparting thixotropy imparting ability and preventing secondary aggregation, fatty acid, fatty acid alkyl ester, fatty acid metal salt, metal salt of resin acid such as rosin acid, reaction product of organic polyisocyanate and stearyl alcohol, Examples thereof include calcium carbonate treated with an organic compound such as coupling agents similar to the silane coupling agent described later. The fatty acid metal salt is preferably a sodium, potassium, calcium or aluminum salt of a fatty acid having 10 to 25 carbon atoms such as stearic acid. As these commercially available products, for example, white gloss flower CC, white gloss flower CCR, white gloss flower R06, VIGOT-10, VIGOT-15, STAVIGOT-15A (manufactured by Shiroishi Kogyo Co., Ltd.), NCC # 3010, NCC # 1010 (more than Nitto Flour Industry Co., Ltd.) Manufactured) and the like. These can be used alone or in combination of two or more. Of these, fatty acid surface-treated calcium carbonate is particularly preferred because of its high thixotropic effect.

The average particle size of the organic surface-treated calcium carbonate is preferably 0.01 to 0.5 μm, more preferably 0.03 to 0.15 μm, and the BET specific surface area is 5 to 200 m ² / g, and further 10 to 60 m ² / g. preferable.
If the average particle diameter is less than 0.01 μm, or if 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 exceeds 0.5 μm. If the BET specific surface area is less than 5 m ² / g, the thixotropic effect is lost, which is not preferable.

  Fillers, adhesion-imparting agents, storage stability improvers (dehydrating agents), and colorants are used for the purpose of increasing or reinforcing, improving adhesion, improving storage stability (storage stability), coloring, etc. It can mix | blend and use for the curable composition in.

  Fillers include synthetic silica such as mica, kaolin, zeolite, graphite, diatomaceous earth, white clay, clay, talc, silicic anhydride, quartz, aluminum powder, zinc powder, precipitated silica, calcium carbonate, calcium hydroxide, magnesium carbonate Inorganic filler such as alumina, fibrous filler such as glass fiber and carbon fiber, inorganic filler such as glass balloon, shirasu balloon, silica balloon, ceramic balloon and other inorganic balloon filler, wood powder Organic, such as walnut flour, rice husk flour, pulp powder, cotton chips, rubber powder, fine powder of thermoplastic or thermosetting resin, polyethylene powder or hollow body, organic balloon filler such as Saran microballoon Other fillers, flame retardant fillers such as magnesium hydroxide and aluminum hydroxide, etc. Among them, those having a particle size 0.01~1,000μm are preferred. These can be used alone or in combination of two or more.

  Examples of the adhesion-imparting agent include epoxy resins, phenol resins, alkyl titanates, and organic polyisocyanates in addition to the coupling agent.

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 the portion thereof. A hydrolyzate is preferable because of its excellent adhesiveness.
Specific examples of the silane coupling agent include methyl silicate, methyltrimethoxysilane, ethyltrimethoxysilane, butyltrimethoxysilane, octyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, vinyltrimethoxy. Silane, 3-methacryloxypropyltrimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, dimethyldimethoxysilane, diethyldimethoxysilane, dibutyldimethoxysilane, diphenyldimethoxy Silane, vinylmethyldimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, trimethylmethoxysilane, triethylmethoxysilane, tri Phenylmethoxysilane, N- (2-aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminopropyltrimethoxysilane, N- (2-aminoethyl) -3-amino Low molecular weight compounds containing alkoxysilyl groups such as propylmethyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldiethoxysilane and the like and / or these silanes having a molecular weight of 500 or less, preferably 400 or less A compound having a molecular weight of 200 to 3,000 may be mentioned as one or more partial hydrolysis condensates of the system coupling agent. These can be used alone or in combination of two or more.

  Examples of the storage stability improver include vinyltrimethoxysilane, calcium oxide, magnesium oxide, p-toluenesulfonyl isocyanate which reacts with moisture present in the composition, and these may be used alone or in combination of two or more. Can be used.

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 total amount of the filler, the adhesion-imparting agent, the storage stability improver, and the colorant is 0 to 500 parts by weight, particularly 5 to 300 parts by weight, per 100 parts by weight of the isocyanate group-containing urethane prepolymer. It is preferable.

  In the curable composition of the present invention, each of the additive components can be used alone or in combination of two or more.

In the present invention, a curing accelerating catalyst can be further added to the curable composition.
Examples of the curing accelerating catalyst include metals such as zinc, tin, lead, zirconium, bismuth, cobalt, manganese, iron, such as metal alkoxides such as tetra-n-butyl titanate, stannous octylate, and tin octenoate. Salts with organic acids such as octylic acid, octenoic acid, naphthenic acid, metal chelate compounds such as dibutyltin bis (acetylacetonate), zirconium tetrakis (acetylacetonate), titanium tetrakis (acetylacetonate), dibutyltin dilaurate , Salts of organic metals and organic acids such as dioctyltin dilaurate, triethylenediamine, triethylamine, tri-n-butylamine, hexamethylenetetramine, 1,8-diazabicyclo [5,4,0] undecene-7 (DBU), 1 , 4-Diazabicyclo [2,2,2] octane Tertiary amines such as (DABCO), N-methylmorpholine and N-ethylmorpholine, or salts 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.

  In the present invention, if necessary, ester solvents such as ethyl acetate, ketone solvents such as methyl ethyl ketone, aliphatic solvents such as n-hexane, alicyclic solvents such as cyclohexane, aromatics such as toluene and xylene Any known organic solvent such as a petroleum solvent such as a petroleum solvent, kerosene, mineral spirit, or industrial gasoline that does not react with an isocyanate group can be used.

Although it does not specifically limit as a manufacturing method of the curable composition in this invention, For example, the said isocyanate group containing urethane prepolymer, an oxygen curable unsaturated compound, and the additive further by the case are made from stainless steel, for example. It can be manufactured by mixing and mixing in a batch or continuous manner under various conditions such as normal pressure, reduced pressure, pressurized pressure, nitrogen flow, etc. it can. Examples of the agitation and mixing device include a planetary mixer, a kneader, an agitator, a nauta mixer, and a line mixer.
Since the produced curable composition is thickened and cured by moisture, it is preferably stored in a container that can block moisture, sealed and stored in order to maintain the storage stability of the contents. The container may be anything as long as it can block moisture, and examples include various kinds of containers such as drum cans, metal or synthetic resin pail cans and bag-like containers, and paper or synthetic resin cartridge-like containers. .

  Furthermore, as a method of using the curable composition in the present invention, specifically, for example, when used as a paint such as a waterproof paint, on a floor surface or an outer wall surface of a building or a civil engineering structure, a brush, a spatula, When a curable composition is applied using a roll coater, spray gun, etc., or used as a building sealant, it is a gun that is pushed out manually, electrically or pneumatically to various joints such as exterior wall joints of buildings. Is used to fill the curable composition, and the excess curable composition is smoothed with a spatula or the like to make the surface flat and cured. A method to remarkably improve the adhesion of the top coating to the surface of the cured product by applying and curing the top coating to the surface of the cured product with a brush, spatula, roll coater, spray gun, etc. Is mentioned.

Examples of the top coat include water-based paints such as emulsion paints and water-based spray paints, as well as various room temperature curable paints such as solvent-based paints and alkyd paints. A room temperature curable paint is preferable in terms of low load, and a room temperature curable water-based paint is particularly preferable.
Moreover, it is preferable to use the curable composition in this invention as a urethane type sealing material composition further as a urethane type sealing material composition by the point which can exhibit the effect of this invention to the maximum.

  In the invention of the present application, the curable composition may be a one-part type depending on the application, or a two-part type using a curable composition as a main agent and an active hydrogen compound such as a low molecular weight alcohol as a curing agent. Although it can be used, there is no trouble of mixing the main agent and curing agent, and it has excellent workability without problems such as poor curing due to poor mixing, so it is particularly one-component moisture curable as a one-component curable composition. It is preferably used as a composition.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

[Synthesis Example 1]
Polyoxypropylene glycol (produced by Asahi Glass Co., Exenol-3021, number average molecular weight 3,200, molecular weight distribution (Mw / Mn) while flowing nitrogen gas into a reaction vessel equipped with a stirrer, thermometer, nitrogen seal tube and heating / cooling device 1.1 to 1.2) 340 g, polyoxypropylene triol (Mitsui Chemicals, MN-4000, number average molecular weight 4,000, molecular weight distribution (Mw / Mn) 1.1 to 1.2) 100 g and 90 g of toluene is charged as a solvent, 54 g of 4,4′-diphenylmethane diisocyanate (manufactured by Nippon Polyurethane Industry, Millionate MT, molecular weight 250) is charged with stirring, and 0.05 g of dibutyltin dilaurate is added as a reaction catalyst, and 70-80 Reaction with stirring for 2 hours at ℃, isocyanate group content by titration The reaction was terminated when it becomes less than the theoretical value (1.04 wt%) was synthesized an isocyanate group-containing urethane prepolymer P-1 by cooling.
The obtained isocyanate group-containing urethane prepolymer P-1 was a viscous transparent liquid at room temperature with an isocyanate group content of 1.00% by mass and a viscosity of 32,000 mPa · s at 25 ° C.

[Synthesis Example 2]
In a reaction vessel equipped with a heating / cooling device similar to Synthesis Example 1, under a nitrogen stream, polyoxypropylene monool (XS-M3000 manufactured by Asahi Glass Co., Ltd., number average molecular weight 3,243, molecular weight distribution (Mw / Mn) 1.0 To 1.1) 300 g (OH equivalent: 0.0925) was charged and stirred with stirring, dibutyltin dilaurate 0.1 g and m-xylylene diisocyanate (Takenate 500, molecular weight 188, Takeda Pharmaceutical Co., Ltd.) 9.1 g (NCO equivalent = 0.0968) (R value (NCO equivalent / OH equivalent) = 1.05), and then heated and stirred at 70 to 80 ° C. for 4 hours to obtain an isocyanate group content of theoretical value (0.06). The reaction was terminated at the time when it became less than or equal to (mass%), and liquid polyoxypropylene urethane resin U-1 was produced.
This liquid polyoxypropylene urethane resin U-1 has a measured isocyanate group content of 0.04% by mass, a viscosity of 3,300 mPa · s / 25 ° C., and a molecular weight distribution (Mw / Mn) of 1.0 to 1.1. The liquid was transparent at room temperature and contained substantially no isocyanate group.

[Example 1]
100 g of the isocyanate group-containing urethane prepolymer P-1 obtained in Synthesis Example 1 while flowing nitrogen gas into a kneading vessel equipped with a cooling device and a nitrogen seal tube, a sucrose-polyetherized resin substantially free of hydroxyl groups (Sanyo) Made by Kasei Kogyo Co., Ltd., Sunflex SPX-80, number average molecular weight 8,000) 50 g, toluene 20 g, calcium carbonate 50 g, titanium oxide 10 g, 3-glycidoxy previously dried in an oven at 80-100 ° C. for 1 day 0.5 g of propyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM403), hindered phenol antioxidant (manufactured by Ciba Specialty Chemicals, IRGANOX 1010, pentaerythritol tetrakis [3- (3,5-di-tert 1-butyl-4-hydroxyphenyl) propionate]), and 2 g of paulownia oil was sequentially added and stirred and kneaded at 60 ° C. or lower until the contents were uniform. Next, 10 g of hydrophilic colloidal silica (manufactured by Nippon Aerosil Co., Ltd., AEROSIL 200) was charged and further kneaded until uniform. Subsequently, it was degassed under reduced pressure at 30 to 100 hPa, filled in a container and sealed to prepare a paste-like one-component moisture-curable urethane-based sealing material composition.

[Example 2]
100 g of the isocyanate group-containing urethane prepolymer P-1 obtained in Synthesis Example 1 while flowing nitrogen gas in the same kneading vessel as in Example 1, a liquid polyoxypropylene-based urethane resin U- containing substantially no isocyanate group 1, 50 g, toluene 30 g, titanium oxide 10 g, 3-glycidoxypropyltrimethoxysilane (manufactured by Shin-Etsu Chemical Co., Ltd., KBM403) 0.5 g, hindered phenol antioxidant (manufactured by Ciba Specialty Chemicals) IRGANOX 1010, 1 g of pentaerythritol tetrakis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]) and 2 g of paulownia oil were sequentially charged and stirred at 60 ° C. or lower until the contents were uniform. Kneaded. Next, 100 g of fatty acid surface-treated calcium carbonate (Shiraishi Kogyo Co., Ltd., Hakujyo Hana CCR) dried in an oven at 80 to 100 ° C. for 1 day in advance and 0.05 g of dibutyltin dilaurate were sequentially added and kneaded until uniform. Subsequently, it was degassed under reduced pressure at 30 to 100 hPa, filled in a container and sealed to prepare a paste-like one-component moisture-curable urethane-based sealing material composition.

Example 3
In Example 2, instead of the liquid polyoxypropylene-based urethane resin U-1 containing substantially no isocyanate group, an acrylic acid alkyl ester-based copolymer resin (manufactured by Toagosei Co., Ltd., UP1000, viscosity 1,000 mPa · s) A paste-like one-component moisture-curable urethane-based sealing material composition was prepared in the same manner except that 50 g of / 25 ° C, Tg-77 ° C) was used.

[Comparative Example 1]
In Example 1, a paste-like one-component moisture-curable urethane-based sealant composition was prepared in the same manner except that 50 g of dioctyl phthalate was used in place of the sucrose polyetherized resin and tung oil was not used. did.

Table 1 shows the test results using these materials.

Test method (1) Extrudability Measured according to “4.14 Extrusion test with cartridge for test” in JIS A1439: 1997 “Test method for sealing material for building” (measurement temperature 23 ° C.). Those having an extrusion time of 5 seconds or less were evaluated as ◯.

(2) Slump In accordance with “4.1 slump test” in JIS A1439: 1997 “Testing method of sealing material for building”, slump (longitudinal) was measured (measurement temperature: 23 ° C.).

(3) Tack-free Measured in accordance with “4.19 Tack-free test” in JIS A1439: 1997 “Testing method of sealing material for building”. A tack-free time of 5 hours or less was rated as “good”.

(4) Adhesiveness of the coating film Using a flexible plate having a size of about 150 mm × 100 mm and a thickness of 5 mm, the sealing material composition was applied to the surface with a thickness of about 3 mm, and the temperature was 23 ° C. and 50% relative humidity. And cured for 14 days. Next, an aqueous top made by Nippon Paint Co., Ltd. is applied as a top coating to the surface of the cured sealing material with a brush to a thickness of about 20 to 30 μm, and the coating is cured and cured at 23 ° C. and 50% relative humidity for 14 days. This was used as a specimen after paint curing.
In addition to this, in order to test the water adhesion resistance of the coating film, a specimen after coating curing was prepared in the same manner as described above, and then immersed in water at 23 ° C. for 7 days. A later test specimen was obtained.
Each specimen was cut in accordance with JIS K 5600-5-6 (1999) “Paint General Test Method, Part 5: Mechanical Properties of Coating Film, Section 6: Adhesion (Cross Cut Method)”. The test was conducted using a multi-blade cutting tool having a blade interval of 2 mm, and the adhesion of the coating film was evaluated according to the following criteria.
Evaluation criteria (numerical value is the number of grids to which the coating film is attached)
○: 20-25 / 25
×: 19 or less / 25

Test results As shown in Table 1 above, the composition of the present invention showed a very improved coating adhesion when the top coat was applied to the surface of the cured product, and the water resistance of the top coat was also extremely high. It was improved.

Claims (6)

  A method in which an oxygen curable unsaturated compound is blended with a curable composition comprising an isocyanate group-containing urethane prepolymer to improve the adhesion of a top coating material to a coating film.   The said oxygen curable unsaturated compound is a compound containing an oxygen curable unsaturated group and a polar group in the molecule, and improves the coating film adhesion of the topcoat paint according to claim 1 Method.   The said oxygen curable unsaturated compound is 1 type, or 2 or more types chosen from the group which consists of drying oil and its modified material, The coating-film adhesiveness of the top-coat paint of Claim 1 is improved How to make.   The method for improving coating film adhesion of a top coating composition according to any one of claims 1 to 3, wherein the curable composition further contains an additive.   The method for improving coating film adhesion of a top coating composition according to claim 4, wherein the additive is a dilution resin. A urethane-based sealant composition suitable for topcoat coating specifications having improved coating film adhesion of a topcoat, comprising an isocyanate group-containing urethane prepolymer and an oxygen curable unsaturated compound.