JPH0414696B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a one-component moisture-curable polyurethane resin composition with excellent storage stability. In general, polyurethane resins have strong toughness, chemical resistance,
It has excellent physical properties such as adhesion and gloss, and is widely used in, for example, paints, adhesives, building materials, elastomers, foams, and molded products. One-component and two-component reactive compositions are generally known as the base of such polyurethane resins, but in both cases polyurethane resins suitable for each purpose are produced through a curing reaction based on isocyanate groups. do. The present inventors have discovered that, apart from the curing reaction based on such isocyanate groups, 1-oxa-3,5
We have focused on the curing reaction by ring opening of -diazine-2,4,6-trione group (hereinafter sometimes simply referred to as trione group), and have studied the use of this reaction for many years. 1-oxa-
The 3,5-diazine-2,4,6-trione group is reactive with active hydrogen in the same way as isocyanate groups; for example, it forms an allophanate bond with hydroxyl compounds, and it forms an allophanate bond with primary amino or secondary amino compounds. It is known that a resin having a biuret bond (hereinafter, such a resin is also referred to as a polyurethane resin) is produced. Although trione groups are much more stable than isocyanate groups, a one-component polyurethane resin composition in which trione groups and active hydrogen compounds coexist,
There are problems with storage stability, and in some cases, when the active hydrogen compound is an amino compound, it is virtually impossible to prepare a one-component composition. The inventors of the present application succeeded in developing a one-component polyurethane resin composition using a compound having a trione group. That is, the present inventors have obtained a new finding that the trione group itself does not substantially have reactivity with aldimine, ketimine, enamine, oxazolidine, or perhydroxazine, and the present invention is based on this finding. It has been done. That is, the present invention provides: (1) 1-oxa-3,5-diazine- in the molecule;
Compounds that have a 2,4,6-trione group (a) and whose terminal isocyanate group is urethanized with a compound that has active hydrogen; and (2) compounds that do not react with group (a) in the molecule and contain moisture. A moisture-curable polyurethane resin composition containing a compound that produces a primary or secondary amino group and has a structure selected from aldimine, ketimine, enamine, osisazolidine, and perhydroxazine. be. 1-oxa-3,5-diazine- as used in the present invention
What is 2,4,6-trione group (a)?

The group having a ring structure represented by [Formula] and the group (b) that does not substantially react with the trione group and generates a primary or secondary amino group with moisture,
Generally, it means a group having a structure called aldimine, ketimine, enamine, oxazolidine, or perhydroxazine (hereinafter sometimes simply abbreviated as blocked amino group). A compound having a group (a) (hereinafter simply referred to as a compound (2-
a)), for example, compounds having an isocyanate group and a trione group.
Examples include compounds obtained by reacting (A) with a compound (B) having active hydrogen, in which the unterminated NCO of (A) is urethanized. Compound (A) can be produced by reacting an aliphatic, alicyclic, or araliphatic polyisocyanate with carbon dioxide. The polyisocyanate used in this reaction is
For example, tetramethylene diisocyanate, hexamethylene diisocyanate, ω, ω'-diisocyanatodipropyl ether, 2,6-diisocyanatocaproic acid ester, 1,6,11-triisocyanatoundecane, bis(isocyanatomethyl)cyclohexane , bis(isocyanatoethyl)cyclohexane, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane, bis(4-isocyanatocyclohexyl)methane, xylylene diisocyanate, bis(2-isocyanatoethyl) Examples include di- or tri-isocyanates such as benzene, or dimers and trimers thereof. These polyisocyanates may be used alone or in mixtures with one another. Furthermore, a compound having an NCO group at the end obtained by reacting these polyisocyanate compounds with a compound having active hydrogen may be used. Also monoisocyanate,
For example, methyl isocyanate, ethyl isocyanate, n-butyl isocyanate, ω-chlorohexyl isocyanate, cyclohexyl isocyanate, cyclohexylmethyl isocyanate, benzyl isocyanate, phenylethylisocyanate, and the like may be mixed. The reaction between these isocyanates and carbon dioxide is usually carried out in the presence of a catalyst, and examples of the catalyst include tertiary phosphines, arsenic compounds, and hydroquinones, with tertiary phosphines being particularly effective. The reaction temperature is usually around -10℃~
The reaction time is about 1 to 20 hours at 100°C. Various compounds are usually added to stop the reaction and to preserve the stability of the product. Alkylating agents, acylating agents,
Acids, ester derivatives, phenols, peroxides,
Sulfur, polysulfide, metal sulfide, halogen, etc. can be used. Such a reaction yields a compound (A) having a trione group and an isocyanate group. The reaction product contains unreacted isocyanate monomers and other low-functional substances, which can be removed using conventional means such as distillation and extraction. It may be subjected to the next reaction without removing the isocyanate and the like. The generated compound (A) having a trione group and an isocyanate group usually has a total number of functional groups of 2 to 5, including the trione group and isocyanate group in one molecule.
Mainly 3 to 4. Among these compounds (A) having a trione group and an isocyanate group, hexamethylene diisocyanate, 1-isocyanato-3-isocyanatomethyl-3,5,5-trimethylcyclohexane, or bis(isocyanatomethyl) is particularly preferred. Mention may be made of compounds derived from diisocyanates such as methyl)cyclohexane. The compound (B) includes a compound containing at least two active hydrogen atoms and a molecular weight of 200 to 500,000, preferably a polyol having 2 to 50 hydroxyl groups in one molecule and a molecular weight of 200 to 50,000, such as polyester. Polyols, polyether polyols, polyether ester polyols, polyester amide polyols, acrylic polyols, polyurethane polyols, epoxy polyols, epoxy-modified polyols, polyhydroxyalkanes (e.g. polybutadiene polyols, saponified products of ethylene/vinyl acetate copolymers), etc. be able to. Some of the hydroxyl groups in these polyols may be replaced with active hydrogen-containing functional groups such as carboxyl groups, amino groups, and thiol groups. When the composition of the present invention is a solvent-free type, among the above polyol components, functional groups of 2 to 6,
Preferably, a compound having a molecular weight of 2 to 4 and an average molecular weight of 10,000 or less, preferably 200 to 5,000 is used. These polyol components also contain approximately 60~
Low molecular weight polyols or low molecular weight polyamines having a molecular weight of 200 may be added. Examples of low molecular weight polyols include ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, cyclohexanedimethanol, glycerol, trimethylolpropane, pentaerythritol, diethylene glycol, triethylene glycol, and dipropylene glycol. Examples of low molecular weight polyamines include ethylenediamine, propylenediamine, trimethylenediamine, diethylenetriamine, tetramethylenediamine, hexamethylenediamine, N,
Aliphatic polyamines such as N'-dibutylhexamethylene diamine, tolylene diamine, phenylene diamine, 4,4'-diaminodiphenylmethane, 4,4'-methylenebisorthochloroaniline, 1,2,4-tridiamine, Aromatic polyamines such as aminobenzene, piperazine, cyclohexylene diamine, isophorone diamine, dipiperidine,
Examples include alicyclic polyamines such as 1,3-di(4-piperidyl)propane, and aromatic aliphatic polyamines such as xylylene diamine hydrazine. Additionally, monoalcohols such as methanol, ethanol, propanol, butanol, octanol, benzyl alcohol, cyclohexanol, 2-ethoxyethanol, monoamines such as ethylamine, n-butylamine, cyclohexylamine, aniline, dimethylamine, dicyclohexylamine are used. You can also do that. When reacting compounds (A) and (B), the
The number of NCO groups and compound (B) are adjusted so that the number of active hydrogens is almost the same. The type of compound (B) and the number of trione groups contained in the generated compound (2-a) are arbitrarily determined depending on the properties required of the desired resin. The number of trione groups contained in compound (2-a) is preferably 1 or more, usually about 2 to 10, and this can be adjusted by the number of functional groups and the amount used of compounds (A) and (B). Compound (B)
When two or more types of components are used, they may be reacted simultaneously or each component may be reacted sequentially. These are reacted using known conditions. The reaction temperature may be approximately -20 to 100°C, preferably 0 to 70°C, and the reaction is usually completed in 5 minutes to 10 hours. If necessary, the reaction may be carried out in the presence of a conventionally used catalyst such as dibutyltin dilaurate, zinc naphthenate, or lead octylate. Compounds having group (b) (hereinafter sometimes simply referred to as compound (2-b)) include, for example, a primary amino group and/or a secondary amino group, and in some cases, Further examples include condensates of compounds having a hydroxyl group and aldehydes or ketones. Examples of aldehydes or ketones include acetaldehyde, propionaldehyde, n-butyraldehyde, i-butyraldehyde, trimethylacetaldehyde, valeroaldehyde, acrolein, crotonaldehyde, furfural, benzaldehyde, acetone, methyl ethyl ketone, methyl isobutyl ketone, diethyl Ketone, diisobutyl ketone, methylheptenone, cyclohexanone, isophorone,
Examples include acetophenone. The reaction of this compound having a primary amino group and/or a secondary amino group, and optionally a hydroxyl group, with an aldehyde or ketone can be carried out under conventionally known reaction conditions. good. The number of blocked amino groups contained in the compound (2-b) can be arbitrarily selected depending on the type of the compound (2-a) and the number of functional groups, but from 2 to
30, usually 2 to 10 is desirable. This number of functional groups is the primary or /
It can be adjusted by selecting a compound having a secondary amino group and, in some cases, a hydroxyl group. Examples of such compounds include ethylenediamine, propylenediamine, tetramethylenediamine, hexamethylenediamine, diaminocyclohexane, diethylenetriamine, ω,ω'-diaminodipropyl ether, ethyl 2,6-diaminocaproate,
1,6,11-triaminoundecane, 3-aminomethyl-3,5,5-trimethylcyclohexylamine, bis(aminocyclohexyl)methane,
Primary polyamines such as xylylene diamine, tris(aminomethyl)benzene, phenylene diamine, tolylene diamine, diaminodiphenylmethane, such as piperazine, 2-methylpiperazine, 2,5-dimethylpiperazine, dipiperidine, 4,4 '-Dipiperidylpropane, N,N'-dimethyl-hexamethylenediamine, N,N'-diisobutyl-2,2,4-trimethyl-hexamethylenediamine, N,N'-diisobutyl-3-
Secondary polyamines such as aminomethyl-3,5,5-trimethyl-cyclohexylamine, and
For example, N-methylethanolamine, N-methylpropanolamine, N,N'-bis(hydroxyethyl)hexamethylenediamine, N,
N'-bis(hydroxypropyl)hexamethylenediamine, N,N'-bis(hydroxyethyl)
Examples include compounds having a secondary amino group and a hydroxyl group, such as -3-aminomethyl-3,5,5-trimethylcyclohexylamine and 4,4'-bis(hydroxyethylamino)dicyclohexylmethane. In addition, compounds having primary or secondary amino groups such as polyether polyamines, polyamide polyamines, polyester polyamines, polyurethane polyamines, and aminoacrylic polymers, as well as amine adducts of polyepoxy compounds, secondary amino groups and hydroxyl groups, etc. Polyethers, polyamides, polyesters, polyurethanes, acrylic polymers, etc. having Further examples include adducts of the compound (C) having a blocked amino group and active hydrogen with isocyanate compounds, and transesterification products with ester compounds. Examples of the active hydrogen contained in this compound (C) include a primary amino group, a secondary amino group, and a hydroxyl group. This compound (C) is
For example, a compound (C') having at least one primary or secondary amino group and an active hydrogen such as a primary or secondary amino group or a hydroxyl group, and the above-mentioned aldehydes or ketones. Examples include condensates of Typical compounds (C') include, for example, compounds having a primary amino group and a hydroxyl group, compounds having a secondary amino group and a hydroxyl group, compounds having a primary amino group and a secondary amino group, and compounds having a primary amino group and a hydroxyl group. compound having a primary amino group, a compound having a secondary amino group and a hydroxyl group, a compound having two primary amino groups, a compound having two secondary amino groups, Examples include compounds having a primary amino group and two hydroxyl groups. Specifically, such a compound includes, for example, 2-(2
-aminoethoxy)ethanol, N-(2-aminoethyl)piperazine, ω-hydroxyhexylamine, N-methyl-1,6-hexanediamine, diethylenetriamine, N-(2-hydroxyethyl)ethylenediamine, 3-aminoethylpiperidine , N-(2-hydroxyethyl)piperazine, 1-amino-3-aminomethyl-3,
Examples include 5,5-trimethylcyclohexane, N-(methylaminoethyl)piperazine, ethanolamine, diethanolamine, and dipropanolamine. In addition to such low molecular weight compounds, amino groups such as those mentioned above,
Polyethers, polyamides, polyesters, polyurethanes, acrylic polymers and the like having hydroxyl groups may also be mentioned. These compounds (2-b) having a blocked amino group such as aldimine, ketimine, enamine, oxazolidine, and perhydroxazine do not necessarily need to be used as a single component, but may be used as a mixture, or two or more types It may be a compound having different blocked amino groups. The ratio of trione groups to blocked amino groups in the composition of the present invention is adjusted to 0.8 to 3, preferably 0.5 to 2. In the case where the blocked amino group is oxazolidine or perhydroxazine, if the hydroxyl group generated by moisture is also involved in the reaction with the trione group, the ratio of the trione group to the blocked amino group is preferably 1 to 4. . Although the composition of the present invention is stable by itself, various additives may be added for the purpose of further increasing storage stability, such as dimethyl sulfate, methyl iodide, toluenesulfonic acid, benzoyl chloride, ethyl chloroformate, etc.
Phosphorus trichloride, boron trifluoride etherate, pentachlorophenol, trichloroacetic acid, ethyl α-bromopropionate, ethyl cyanoacetate, malonitrile, picric acid, 2,4,6-trinitrobenzoic acid, N,N,N' , N'-tetramethylhexamethylene diamine, N-ethylpiperidine, and other alkylating agents, acylating agents, acids, ester derivatives, nitriles, phenols, tertiary amines, and the like can be added. Also, blocked amino compounds such as primary or secondary monoamines such as aldimine, ketimine, and enamine can also be excellent additives for stabilization. Furthermore, for the purpose of promoting the reaction of trione groups, tertiary amines, tertiary phosphine or quaternary ammonium, weak acid salts, hydroxides or alcoholates of alkali metals or alkaline earth metals, organic compounds of metals, organic Acid salts, inorganic salts, etc. may be added.
Various additives such as pigments, dyes, leveling agents, antifoaming agents, anti-sagging agents, fillers, plasticizers, antioxidants, and ultraviolet absorbers can be used as appropriate. The composition of the present invention can be used in either a solvent type or a non-solvent type, but when used as a solvent type, for example, toluene, xylene, ethyl acetate, butyl acetate, cellosolve acetate, methyl ethyl ketone, methyl isobutyl ketone can be used. , cyclohexanone, and other solvents that can be used for ordinary urethane resins may be used, and the type, amount, etc. thereof are appropriately determined depending on the purpose. By contacting the composition of the present invention with moisture, the composition is cured to form a polyurethane resin. Water vapor that normally exists in the air can be used as moisture, but water vapor that exists in gases other than air may also be used, and water vapor that is dispersed or suspended in the gas as mist, mist, etc. Existing water can also be used. Further, depending on the purpose, it may be brought into contact with water existing in liquid form. For example, the composition of the present invention may be mixed with liquid water and used in a dissolved or dispersed state, or the surface of the composition may be brought into contact with liquid water. Furthermore, water-containing crystals that retain water in the form of crystal water, adsorbed water, etc., hygroscopic substances, water-absorbing substances, and the like may be mixed with the composition to coexist. Room temperature is sufficient for contacting with water, but if you want to carry out the curing reaction in a shorter time, 40 to 140
The reaction can be promoted by adjusting the temperature to an appropriate temperature within the range of °C. When the water to be contacted exists in the form of water vapor, the water vapor pressure may be selected within the range of 3 to 400 mmHg, but usually 5 to 100 mmHg is sufficient. Further, the contact time with water varies depending on the resin composition, temperature, resin thickness, water concentration, etc., but it is usually 3 to 30 minutes when heating, and 10 minutes to several days at room temperature. However, these temperatures, water vapor pressures, contact times, etc. may be selected depending on the purpose, and are not necessarily limited to the above ranges. The composition of the present invention can be widely applied to various application fields such as paints, adhesives, building materials, elastomers, and foam molded products. When applying or filling the base material and curing it, the base material is:
For example, metals such as iron and aluminum, wood, plastics, rubber, paper, cloth, tiles, concrete, slate, various boards, and composite materials can be used. Despite the coexistence of trione groups and blocked amino groups, the composition of the present invention has excellent storage stability and can withstand long-term storage, and can be cured and dried in a short time even at room temperature due to contact with moisture. It is carried out. In addition, by applying slight heat, it is possible to cure and dry in an even shorter time, allowing line painting, adhesion, etc.
It can also be advantageously used in fields that require continuous curing and drying in a short period of time, such as film forming processes. Furthermore, the cured product is non-yellowing and can be used for outdoor applications where weather resistance is particularly required. Hereinafter, the present invention will be explained in more detail with reference to Examples and Reference Examples, but these are not intended to limit the present invention in any way. Reference example 1 841g of hexamethylene diisocyanate at 40℃
While blowing carbon dioxide gas at a rate of 300 ml/min, 1.8 g of tri-n-butylphosphine was added, and the reaction was carried out for 6 hours while stirring. The supply of carbon dioxide gas was stopped, 0.3 g of sulfur powder was added, and the mixture was stirred for 30 minutes and then cooled. When the raw materials were removed using a thin film evaporator, 255 g of a pale yellow, slightly viscous liquid compound containing an isocyanate group and a trione group was obtained. This compound had an NCO content of 4.78 meq/g, an oxadiazinetrione content of 2.77 meq/g, a residual monomer content of 0.4%, and a viscosity (Gardner) at 25°C of Y to Z (2000 cps). Reference Example 2 2.1 g of tri-n-butylphosphine was added to 971 g of 1,3-bis(isocyanatomethyl)cyclohexane while blowing carbon dioxide gas at 1000 ml/min at 0°C.
was added, and the reaction was carried out for 7 hours while stirring. Replace carbon dioxide supply with nitrogen and use benzoyl peroxide
2.7 g was added and stirred for 30 minutes. When the raw materials were removed by evaporation of the product using a thin film distillation apparatus, 165 g of a pale yellow viscous liquid compound having an isocyanate group and a trione group was obtained. This compound has an NCO group content of 4.40meq/g and an oxadiazinetrione content.
The amount of residual monomer was 2.18 meq/g and 0.5%. Reference Example 3 7.5 g of tri-n-butylphosphine was added to 1010 g of hexamethylene diisocyanate at 20° C. while blowing carbon dioxide gas at 800 ml/min, and the mixture was reacted for 9 hours with stirring. Stop the supply of carbon dioxide gas,
While blowing nitrogen, 4.5 g of 80% t-butyl hydroperoxide was added and stirred for 30 minutes. The product was subjected to thin film distillation to remove raw materials, yielding 924 g of a pale yellow viscous liquid compound having an isocyanate group and a trione group. This compound has an NCO content of 3.30meq/g and an oxadiazinetrione content.
It had 3.28 meq/g, and the residual monomer amount was 0.8%. Example 1 340 g of the compound obtained in Reference Example 2 was heated to 70°C, and 1480 g of polyoxypropylene glycol (OH value 38) and 0.1 dibutyltin dilaurate were added to it.
g, add and dissolve 0.2 g of benzoyl chloride, 60
The reaction was carried out at ℃ for 5 hours. In this, n-propanol
Add 33g and react at 60℃ for another 5 hours.
The NCO group disappeared and a compound having an oxadiazinetrione group was obtained. N-2-aminoethylpiperazine and excess isobutyraldehyde were refluxed under heating, the resulting water was removed with a water droplet separator, and then distilled to obtain an aldimine-enamine derivative of N-2-aminoethylpiperazine. A composition was prepared by mixing 24 g of this derivative and 500 g of the above urethane prepolymer. This composition was applied onto a steel plate to a thickness of 5 mm, and the applied material was
It was left in air at 50% humidity. After one hour, the surface was hardened, and after two weeks, an elastic body completely hardened to the inside was obtained. Furthermore, when this composition was stored at room temperature with moisture excluded, it remained stable without gelation even after being left for 6 months. Example 2 303g of the compound obtained in Reference Example 3 was dissolved in ethyl acetate.
It was dissolved in 150g. Add n-butanol to this solution.
55 g and 0.02 g of dibutyltin dilaurate were added and the reaction was carried out at 70° C. for 2 hours to obtain a compound in which n-butanol had completely reacted. Excess methyl isobutyl ketone was added to a toluene solution of an acrylic polymer having amino groups (amino group equivalent: 830, average molecular weight: approximately 8000, constituent units are styrene, methyl methacrylate, n-butyl acrylate, and 2-aminoethyl methacrylate). The mixture was refluxed under heating, the water produced was removed using a water separator, and the mixture was concentrated to obtain a ketimine derivative of an aminoacrylic polymer with a solid content of 50%. This derivative 180
A two-component composition was prepared by mixing g and 41 g of the previously obtained product. This is applied onto a steel plate with a film thickness of approx.
The coating was applied to a thickness of 30 μm, and when the coating was left at room temperature, it hardened after 3 hours. One day later, a rubbing test (50 times) with ethyl acetate was performed, but no scratches were observed. Example 3 623 g of polyester diol (OH value: 90; synthesized from phthalic anhydride, 1,4-butanediol, and ethylene glycol) was dissolved in 400 g of ethyl acetate. Add 313g of the compound obtained in Reference Example 1 to this solution.
and 0.1 g of dibutyltin dilaurate were added and dissolved, and the mixture was reacted at 60°C for 2 hours. When 25 g of ethanol was added to this reaction solution and the mixture was further reacted at 60° C. for 3 hours, the NCO group disappeared and a compound having an oxadiazinetrione group was obtained. on the other hand,
159 g of 2-isopropyl-3-(2-hydroxyethyl)-1,3-osisazolidine obtained from diethanolamine and isobutyraldehyde was dissolved in 100 g of ethyl acetate, and an adduct of isophorone diisocyanate and trimethylolpropane (75 g) was dissolved in 100 g of ethyl acetate. % ethyl acetate solution, NCO equivalent 390)
390 g and 0.6 g of dibutyltin dilaurate were added and reacted at room temperature for 10 hours to obtain a polyoxazolidine solution. A two-component composition containing a catalyst was prepared by mixing 65 g of this solution with 157 g of the above urethane prepolymer and 0.7 g of N,N,N',N'-tetramethyl-1,6-hexanediamine. This composition was applied onto a steel plate, and the applied product was cured by heating at 80° C. for 20 minutes under a water vapor pressure of 20 mmHg. The cured film did not cause any scratches in the ethyl acetate rubbing test (30 reciprocations). When this composition was stored at 40° C. with moisture excluded, it remained stable without gelation for 3 months.

Claims (1)

[Claims] 1 (1) 1-oxa-3,5-diazine- in the molecule
A compound having a 2,4,6-trione group (a) and whose terminal isocyanate group is urethanized with a compound having active hydrogen, and (2) a compound that does not react with the group (a) in the molecule and has no moisture content. to produce a primary or secondary amino group, aldimine, ketimine, enamine,
1. A composition for a moisture-curable polyurethane resin, comprising a compound having a structure selected from oxazolidine and perhydroxazine.