JP7615533B2 - Urethane-forming composition - Google Patents

Description

This disclosure relates to a urethane-forming composition.

Various organometallic catalysts are used as catalysts to increase the reactivity and curing properties of the urethane reaction.

However, when curing a polyfunctional polyol and a polyfunctional isocyanate using an organometallic catalyst to enhance the curing properties, wrinkles are likely to occur due to shrinkage, and problems arise in that polyurethanes with a stable, smooth and good appearance cannot be obtained. Furthermore, such catalyst systems are highly active in the urethanization reaction, and urethane-forming compositions using them gel rapidly when heated, dried, or aged, resulting in poor moldability.

Patent Document 1 discloses a method of using a plasticizer to suppress the cure shrinkage of urethane. However, the method of using a plasticizer requires the use of a large amount of a low molecular weight compound, which increases costs, and almost all of the plasticizer remains in the polyurethane, which causes problems such as poor cure properties of the resulting polyurethane, reduced hardness, and impaired urethane properties.

In other words, there was a need for a urethane-forming composition that can suppress shrinkage during the reaction and curing of a multifunctional polyol and an isocyanate using an organometallic catalyst, has good curability and moldability, and produces a smooth, wrinkle-free, good-looking appearance without compromising the hardness and other properties of the resulting polyurethane.

Patent No. 6628453

One aspect of the present invention is directed to providing a urethane-forming composition that suppresses cure shrinkage even when an organometallic catalyst is used, has good curability and moldability, and contributes to the formation of polyurethane that has good physical properties such as hardness, is wrinkle-free, smooth, and has a good appearance, and a urethane-forming composition solution that contains the urethane-forming composition.

Yet another aspect of the present invention is directed to providing a polyurethane sheet made of the polyurethane.

As a result of intensive research to solve the above problems, the inventors have surprisingly found that by combining a triazole derivative with a specific urethane-forming catalyst and allowing the triazole derivative to act in an excess ratio of at least a specific molar ratio relative to the specific urethane-forming catalyst, it is possible to solve the problem of poor appearance due to wrinkles while maintaining curability, and have thus completed the present invention.

The embodiments of the present invention are as follows [1] to [18].
[1] A urethane-forming composition (G) comprising a polyol (A), an isocyanate compound (B), a triazole derivative (C), and a urethane-forming catalyst (D) containing a metal component,
a content of the triazole derivative (C) in the urethane-forming composition (G) of 0.1 mass% or more and 3.0 mass% or less, a content of the urethane-forming catalyst (D) of 0.5 mass% or less, and a molar ratio of the triazole derivative (C)/the urethane-forming catalyst (D) containing a metal component of 7 times or more.
[2] The urethane-forming composition (G) according to [1], characterized in that the triazole derivative (C) is a benzotriazole derivative.
[3] The urethane-forming composition (G) according to [1] or [2], characterized in that the triazole derivative (C) is a benzotriazole derivative having one or more phenolic hydroxyl groups.
[4] The urethane-forming composition (G) contains a keto-enol tautomer compound (E) as an essential component,
The urethane-forming composition (G) according to any one of [1] to [3], characterized in that the keto-enol tautomer compound (E) contains at least one of ethyl acetoacetate and acetylacetone as an essential component.
[5] The urethane-forming composition (G) according to any one of [1] to [4], characterized in that the urethane-forming composition (G) contains an acid retarder (F) as an essential component.
[6] A urethane-forming composition solution (L) comprising the urethane-forming composition (G) according to any one of [1] to [5] and an organic solvent,
The urethane-forming composition solution (L) is characterized in that the concentration of the urethane-forming composition (G) in the urethane-forming composition solution (L) is 10% by mass or more and 95% by mass or less.
[7] A polyurethane (L) which is a reaction product of the urethane-forming composition (G) according to any one of [1] to [5] and the urethane-forming composition (G) in the urethane-forming composition solution (L) according to [6].
[8] A polyurethane sheet comprising the polyurethane (M) according to [7]. [9] A urethane prepolymer composition (I) comprising a urethane prepolymer (H), a triazole derivative (C), and a urethane catalyst (D) containing a metal component,
the urethane prepolymer (H) is a reaction product of at least a polyol (A) and a polyisocyanate (B) and has at least one hydroxyl group in one molecule;
the molar ratio (M _NCO /M _OH ) of the sum of NCO groups (M _NCO ) contained in the isocyanate (B) to the sum of hydroxyl groups (M _OH ) contained in the polyol (A) forming the urethane prepolymer (H) is less than 1.0,
the content of the triazole derivative (C) in the urethane prepolymer composition (I) is 0.1% by mass or more and 3.0% by mass or less, the content of the urethane-forming catalyst (D) is 0.5% by mass or less, and the molar ratio of the triazole derivative (C) to the urethane-forming catalyst (D) containing a metal component is 7 times or more.
[10] The urethane prepolymer composition (I) according to [9], wherein the triazole derivative (C) is a benzotriazole derivative.
[11] The urethane prepolymer composition (I) according to [9] or [10], wherein the triazole derivative (C) is a benzotriazole derivative having one or more phenolic hydroxyl groups.
[12] The urethane prepolymer composition (I) contains a keto-enol tautomer compound (E) as an essential component,
The keto-enol tautomer compound (E) contains at least one of ethyl acetoacetate and acetylacetone as an essential component.
The urethane prepolymer composition (I) according to any one of [9] to [11].
[13] The urethane prepolymer composition (I) according to any one of [9] to [12], characterized in that the urethane prepolymer composition (I) contains an acid retarder (F) as an essential component.
[14] A urethane prepolymer composition solution (K) comprising the urethane prepolymer composition (I) according to any one of [9] to [13] and an organic solvent, wherein the concentration of the urethane prepolymer composition (I) in the urethane prepolymer composition solution (K) is 10% by mass or more and 95% by mass or less.
[15] A urethane-forming composition (G) comprising the urethane prepolymer composition (I) according to any one of [9] to [13] and an isocyanate compound (J).
[16] A urethane-forming composition solution (L) containing the urethane prepolymer composition solution (K) according to [14] and an isocyanate compound (J).
[17] A polyurethane (M) which is a reaction product of the urethane-forming composition (G) according to [15] and the urethane-forming composition solution (L) according to [16].
[18] A polyurethane sheet comprising the polyurethane (M) according to [17].

The urethane-forming composition of the present invention has good moldability when applied to a coating machine or the like to obtain polyurethane, and although it uses an organometallic catalyst to exhibit high curability, it can suppress cure shrinkage, and can form polyurethane with good physical properties such as hardness and a smooth, wrinkle-free appearance.

In addition, polyurethanes obtained by using the urethane-forming composition of the present invention can be used effectively in a wide range of applications, including sealants, paints, pressure sensitive adhesives, and bonding agents.

The following provides a detailed description of exemplary embodiments of the present invention.

The urethane-forming composition (G) according to one embodiment of the present invention is a urethane-forming composition (G) containing a polyol (A), an isocyanate compound (B), a triazole derivative (C), and a urethane-forming catalyst (D) containing a metal component, in which the content of the triazole derivative (C) in the urethane-forming composition (G) is 0.1% by mass or more and 3.0% by mass or less, the content of the urethane-forming catalyst (D) is 0.5% by mass or less, and the molar ratio of the triazole derivative (C)/the urethane-forming catalyst (D) containing a metal component is 7 times or more.

Each component will be described below.
<Polyol (A)>
The polyol (A) may be a commercially available polyol used in the production of polyurethane. Although not particularly limited, examples thereof include polyether polyols obtained by ring-opening polymerization of alkylene oxide or tetrahydrofuran, polymer polyols obtained by radical polymerization of vinyl monomers in polyether polyols, polyester polyols obtained by polycondensation of polyhydric alcohols and polycarboxylic acids, polyesteramide polyols obtained by polycondensation of polyhydric alcohols, polycarboxylic acids, and amino alcohols, polylactone polyols obtained by ring-opening polymerization of lactones, polycarbonate polyols obtained by polycondensation of polyhydric alcohols and carbonates, acrylic polyols, polybutadiene polyols and hydrogenated products thereof, polyisoprene polyols and hydrogenated products thereof, partially saponified ethylene-vinyl acetate copolymers, natural oil-based polyols such as soybean oil and castor oil, halogen and/or phosphorus-based polyols, phenol-based polyols, etc. These polyols may be used alone or in combination of two or more.

Among these, it is preferable to include at least one of polyester polyols and polyether polyols, since although wrinkles and other appearance defects are likely to occur, these can be easily suppressed by adding a triazole derivative, they are highly versatile and easily available, and they tend to exhibit a good balance of physical properties including transparency and hardness. The proportion of polyester polyol and/or polyether polyol is preferably in the range of 10 to 100 parts by weight per 100 parts by weight of polyol.

Examples of polyester polyols include compounds derived from dibasic acids and polyhydric alcohols. Although not particularly limited, examples include polyester polyols derived from adipic acid, orthophthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride, succinic acid, azelaic acid, sebacic acid, linosyl acid, dimethyl terephthalate, and polyethylene terephthalate. Other examples include lactone-based polyester polyols obtained by ring-opening polymerization of cyclic esters such as ε-caprolactone and methyl valerolactone.

Examples of polyether polyols include polyether polyol compounds obtained by ring-opening addition polymerization of alkylene oxides such as ethylene oxide and propylene oxide, or tetrahydrofuran, to initiators such as ethylene diamine, tolylene diamine, sucrose, amino alcohols, butanol, glycerin, diethylene glycol, and low molecular weight polypropylene glycols having a molecular weight of 1000 or less. When using polyether polyols, although there are no particular limitations, it is preferable that they have at least one of ethylene oxide residues and propylene oxide residues, as this tends to improve moldability and transparency.

Examples of halogen- and/or phosphorus-based polyols include halogen-containing polyols obtained by ring-opening polymerization of epichlorohydrin or trichlorobutylene oxide, halogen-based polyols such as brominated pentaerythritol/sucrose-based polyols and tetrabromophthalic acid polyesters, and phosphorus-based polyols obtained by adding alkylene oxides to phosphoric acid compounds.

Examples of phenol-based polyols include Mannich-based polyols obtained by Mannich-modifying phenol or phenol derivatives such as nonylphenol and alkylphenol with formaldehyde and secondary amines such as diethanolamine, ammonia, primary amines, etc., and then ring-opening addition-polymerizing alkylene oxides such as ethylene oxide and propylene oxide.

The polyol is not particularly limited as long as it has at least one hydroxyl group at the polymer end, branched chain end, etc., but the crosslinked structure of the polyurethane obtained by reaction with the isocyanate compound becomes dense, and although wrinkles and other appearance defects are likely to occur, these can be suppressed by adding a triazole derivative, and the resulting urethane is likely to exhibit a good balance of physical properties including transparency and high hardness, so it is preferable for it to have 2 to 8 hydroxyl groups in the molecule, and more preferably, a polyol having 2 to 4 hydroxyl groups in the molecule because it is easy to obtain, has a wide range of designs, and is highly versatile, and most preferably, a multifunctional polyol having 3 hydroxyl groups. When the average functionality of the polyol is 1.0 or more but less than 2.0, it is preferable to use a multifunctional isocyanate with 3 or more isocyanate functional groups and, if necessary, to include a component having two or more active hydrogens that react with isocyanates, such as water or diamine, in order to densenize the crosslinked structure.

Although not particularly limited, polyurethane raw materials preferably have a hydroxyl value of 1 to 1000 (mgKOH/g), and more preferably 10 to 800 (mgKOH/g). The hydroxyl value can be calculated according to the method of JIS K1557, etc.

The molecular weight of the polyol (A) is not particularly limited, but since the polyol (A) is likely to have excellent curability and moldability, the number average molecular weight calculated from the hydroxyl value and the number of functional groups is preferably in the range of 100 to 50,000, and more preferably in the range of 500 to 10,000.

<Isocyanate Compounds (B) and (J)>
The isocyanate compounds (B) and (J) are not particularly limited, and examples thereof include commercially available isocyanates used in the production of polyurethanes, such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,4'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, tolidine diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, lysine diisocyanate, triphenylmethane triisocyanate, tetramethylxylene diisocyanate, 1,6 Examples of the isocyanate-containing prepolymers include hexamethylene diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, norbornane diisocyanate, lysine ester triisocyanate, 1,6,11-undecane triisocyanate, 1,8-diisocyanate-4-isocyanate methyl octane, 1,3,6-hexamethylene triisocyanate, bicycloheptane triisocyanate, trimethylhexamethylene diisocyanate, isocyanate-containing prepolymers obtained by reacting these with polyols, and mixtures of two or more of these. Furthermore, modified products of these isocyanates (modified products containing a urethane group, a carbodiimide group, an allophanate group, a urea group, a biuret group, an isocyanurate group, an amide group, an imide group, a uretonimine group, a uretdione group, or an oxazolidone group) and condensates (sometimes called polynuclear products) such as polymethylene polyphenylene polyisocyanate (polymeric MDI) are also included. These isocyanates may be used alone or in combination of two or more.

Isocyanate compounds (B) and (J) are not particularly limited as long as they have at least one isocyanate group at the polymer end, branched chain end, etc., but the crosslinked structure of the polyurethane obtained by the reaction with the polyol becomes dense, and although wrinkles and other appearance defects tend to occur, these can be suppressed by adding a triazole derivative, and the obtained urethane is likely to exhibit good physical properties including transparency and high hardness, so it is preferable that the average functionality of the isocyanate group is 2.0 or more.

When the average functionality of the isocyanate group is 1.0 or more but less than 2.0, it is preferable to use a multifunctional polyol having a polyol functionality of 3 or more, and, if necessary, to include a multifunctional component that reacts with the polyol, such as polyisothiocyanate, to form a dense crosslinked structure.

The content of isocyanate compound (B) is preferably in the range of 0.1 to 300 parts by weight per 100 parts by weight of polyol, since a small amount may result in a decrease in hardness, and a large amount may result in poor moldability or may make it difficult to suppress wrinkles even when a triazole derivative is added, and more preferably in the range of 1 to 50 parts by weight per 100 parts by weight of polyol, since this makes it easier to achieve both coating appearance and moldability. When producing a polyurethane foam product, the range of 10 to 300 parts by weight per 100 parts by weight of polyol is preferable.

The polyol (A) and the isocyanate compound (B) used in the present invention may be partially reacted in advance to form a urethane prepolymer (H), or a urethane prepolymer composition (I) containing a catalyst and various additives, or a urethane prepolymer composition solution (K) containing a solvent, as required, may be formed.

When a urethane prepolymer (H) is formed using a composition containing an isocyanate compound (B), a urethane-forming composition (G) can be produced by adding an isocyanate compound (J) as a crosslinking agent after the formation of the prepolymer.

<Triazole Derivative (C)>
The urethane-forming composition (G) is characterized by containing a triazole derivative (C). By containing the triazole derivative (C) in the urethane-forming composition, it is possible to stably suppress the cure shrinkage that occurs when the multifunctional urethane raw material is cured by reaction using a metal catalyst, and form a urethane with good moldability and good appearance without wrinkles. Furthermore, the obtained urethane has high hardness and is likely to exhibit good transparency.

This is thought to be because the triazole derivative (C) acts on the metal catalyst and suppresses reactivity during the curing reaction during drying, aging, etc., thereby suppressing shrinkage caused by the rapid curing of the multifunctional polyol and isocyanate, and the reaction proceeds evenly, resulting in a high degree of crosslinking after completion of the reaction, which gives the resulting urethane high hardness and good transparency.

If the urethane-forming composition does not contain triazole derivative (C), it is difficult to form a urethane with a good, wrinkle-free coating appearance that is stable when forming the urethane using a polyol or isocyanate with a high number of functional groups and a metal catalyst, as the effects of processing conditions are minimal. In addition, transparency is likely to deteriorate, making it difficult to use.

The content of triazole derivative (C) in urethane-forming composition (G) is 0.1% by mass or more and 3.0% by mass or less. In particular, the content of triazole derivative (C) is preferably 0.2% by mass or more and 2.0% by mass or less, and more preferably 0.3% by mass or more and 1.5% by mass or less, because this makes it easier to form a coating film with higher transparency and better appearance.

If the content of triazole derivative (C) in urethane-forming composition (G) is less than 0.1% by mass, the wrinkle-inhibiting effect is low, making it difficult to stably form a urethane with a good coating appearance. If it exceeds 3% by mass, phase separation is likely to occur during storage, processability deteriorates, and compatibility deteriorates, resulting in poor transparency of the urethane obtained and uneven coating, resulting in poor appearance. The gel fraction decreases, and physical properties such as tack expression and hardness deteriorate, making it difficult to use.

The molar ratio of triazole derivative (C) to urethane catalyst (D) containing a metal component in the urethane-forming composition (G) (triazole derivative (C)/urethane catalyst (D) containing a metal component) is 7 times or more. In particular, the molar ratio of triazole derivative (C) to urethane catalyst (D) containing a metal component (triazole derivative (C)/urethane catalyst (D) containing a metal component) is preferably 10 times or more and 500 times or less, more preferably 15 times or more and 300 times or less, and most preferably 25 times or more and 200 times or less, because it is easy to maintain good compatibility and to express higher transparency, and it is easy to have a high wrinkle suppression effect and excellent coating appearance.

If the molar ratio of triazole derivative (C) to the metal catalyst is less than 7 times, the molar ratio of the triazole derivative acting on the metal catalyst is relatively small, so the adjustment effect of the reaction activity of the metal catalyst is small, it becomes difficult to suppress wrinkles due to cure shrinkage, and a urethane with a good coating appearance cannot be formed, making it difficult to use.

The triazole derivative (C) in the urethane-forming composition (G) is not particularly limited as long as it contains a triazole structure containing three nitrogen atoms in a five-membered ring. In compounds that do not contain three nitrogen atoms, such as triazole derivatives, nitrogen is appropriately coordinated to the metal catalyst, which is thought to be the effect of mildening the catalytic activity during heating, drying, and aging, and the curing shrinkage suppression effect is small, making it difficult to form a urethane with a stable, wrinkle-free coating film with good appearance.

Triazole derivatives (C) that can be suitably used include, for example, 1,2,4-triazole derivatives and 1,2,3-triazole derivatives.

Among them, it is preferable to include one or more benzotriazole derivatives, which are a type of 1,2,3-triazole derivative, because they have a high effect of suppressing cure shrinkage and are easy to form a urethane with a good coating appearance. In addition, it is preferable for the benzotriazole derivative to have one or more phenolic hydroxyl groups because they tend to have a high effect of suppressing wrinkles, and it is even more preferable for the benzotriazole derivative to have a substituent at the ortho position of the phenolic hydroxyl group because it is difficult to react with isocyanate to deactivate it and it is easy to suppress wrinkles stably. Examples of substituents that are preferable to have at the ortho position of the phenolic hydroxyl group include quaternary substituents such as t-butyl groups, tertiary substituents such as triazolyl groups, and secondary substituents such as methylene groups. In addition, it is preferable to have an alkyl group or an ester group at the para position of the phenolic hydroxyl group because the triazole derivative is easy to liquefy, has good compatibility, is unlikely to cause coating unevenness, and is easy to form a urethane with a transparent appearance.

The triazole derivative (C) is preferably in the molecular weight range of 100 to 2000, more preferably in the molecular weight range of 200 to 1000, and most preferably in the molecular weight range of 300 to 700, because it is less likely to volatilize or bleed from the urethane during curing, and therefore has a high wrinkle suppression effect, and is also more likely to have good compatibility and form a urethane with a transparent appearance and less uneven coating of the resulting urethane. Although not particularly limited, it is preferable that these triazole derivatives (C) are liquid at room temperature, because they tend to have excellent compatibility and the coating film appearance, such as the transparency, of the resulting urethane is more likely to be good. If necessary, a small amount of diluent of 10% by mass or less may be contained relative to the triazole derivative in order to make it liquid.

Although not limited to these, examples of 1,2,4-triazole derivatives include compounds represented by the following general formula (1). These tautomers are also included.

(In formula (1), R1, R2, and R3 are not particularly limited, and the type and presence or absence of a substituent can be selected arbitrarily.)
Examples of R1, R2, and R3 include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl or alkyl-substituted aryl group, a heteroaryl or alkyl-substituted heteroaryl group, an alkoxyalkyl group, an acyloxyalkyl group, a hydroxy group, a halogen, a polyoxyalkylene group, and hydrogen.

Examples of the above compounds include 4-amino-1,2,4-triazole, 1,2,4-triazole, and 3-mercapto-1,2,4-triazole.

Although not limited to these, examples of 1,2,3-triazole derivatives include compounds represented by the following general formula (2). These tautomers are also included.

(In formula (2), R1, R2, and R3 are not particularly limited, and the type and presence or absence of a substituent can be selected arbitrarily.)
Examples of R1, R2, and R3 include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl or alkyl-substituted aryl group, a heteroaryl or alkyl-substituted heteroaryl group, an alkoxyalkyl group, an acyloxyalkyl group, a hydroxy group, a halogen, a polyoxyalkylene group, hydrogen, etc. In the formula, R1 and R2 may be independent or may be bonded to form a ring such as an aryl, heteroaryl, cycloalkyl, or cycloalkenyl.

Benzotriazole derivatives are 1,2,3-triazole derivatives, which are compounds having a benzene ring structure containing the carbon atoms at the 4th and 5th positions of the triazole, and include, but are not limited to, compounds represented by the following general formula (3). These tautomers are also included.

(In formula (3), R1, R2, R3, R4, and R5 are not particularly limited, and the type and presence or absence of a substituent can be selected arbitrarily.)
Examples of R1, R2, R3, R4 and R5 include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl or alkyl-substituted aryl group, a heteroaryl or alkyl-substituted heteroaryl group, an alkoxyalkyl group, an acyloxyalkyl group, a hydroxy group, a halogen, a polyoxyalkylene group, hydrogen, etc. Among these, it is preferable that R5 has a phenyl ring structure directly bonded thereto, since this has a high wrinkle-suppressing effect and tends to result in a stable and good coating film appearance.

The above compounds are not particularly limited, but examples thereof include 2,2'-[[(methyl-1H-benzotriazol-1-yl)methyl]imino]bisethanol (TT-LYK manufactured by Johoku Chemical Industry Co., Ltd.), 1-[N,N-bis(2-ethylhexyl)aminomethyl]methylbenzotriazole (TT-LX manufactured by Johoku Chemical Industry Co., Ltd.), carboxybenzotriazole (CBT-1 manufactured by Johoku Chemical Industry Co., Ltd.), 1-[N,N-bis(2-ethylhexyl)aminomethyl]benzotriazole (BT-LX manufactured by Johoku Chemical Industry Co., Ltd.), 1,2,3-benzotriazole, 6-(2-benzotriazolyl)-4-tert-octyl-6'-tert-butyl-4'-methyl-2,2'-methylenebisphenol (J AST-500), 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-tert-octylphenol] (JF-832 manufactured by Johoku Chemical Industry Co., Ltd.), 2-(2'-hydroxy-5'-tert-octylphenyl)benzotriazole (JF-83 manufactured by Johoku Chemical Industry Co., Ltd.), 2-(2'-hydroxy-3',5'-di-tert-amylphenyl)benzotriazole (JF-80 manufactured by Johoku Chemical Industry Co., Ltd.), 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole (JF-79 manufactured by Johoku Chemical Industry Co., Ltd.), 2-(2'-hydroxy-5'-methylphenyl)benzotriazole (JF-77 manufactured by Johoku Chemical Industry Co., Ltd.), etc.

Benzotriazole derivatives having a phenolic hydroxyl group include compounds having a phenolic hydroxyl group in at least one of R1, R2, R3, R4, and R5 in the above general formula (3). The phenolic hydroxyl group refers to a hydroxyl group directly bonded to a benzene ring, and the aryl group containing the phenolic hydroxyl group may or may not be directly bonded to the benzotriazole. However, it is preferable that the aryl group containing the phenolic hydroxyl group is directly bonded to the benzotriazole, since this promotes coordination of the triazole to the metal, adjusts the reactivity, and makes it easier to suppress wrinkles.

Among them, compounds in which the ortho position of the phenoxy group is directly bonded to the triazole nitrogen are more preferable because isocyanate and phenolic hydroxyl groups are less likely to react with each other and the wrinkle-inhibiting effect is likely to be enhanced. Examples of such compounds include, but are not limited to, the compounds shown in the following general formula (4). These tautomers are also included.

(In formula (4), R1, R2, R3, R4, R5, R6, R7, and R8 are not particularly limited, and the type and presence or absence of a substituent can be selected arbitrarily.)
Examples of R1, R2, R3, R4, R5, R6, R7, and R8 include an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, a cycloalkenyl group, an aryl or alkyl-substituted aryl group, a heteroaryl or alkyl-substituted heteroaryl group, an alkoxyalkyl group, an acyloxyalkyl group, a hydroxy group, a halogen, a polyoxyalkylene group, hydrogen, etc. Among these, it is more preferable that R8 in the general formula is a quaternary substituent such as a t-butyl group, a tertiary substituent such as a triazolyl group, or a secondary substituent such as a methylene group, and it is preferable that R6 has a substituent such as an alkyl group or an ester group in order to facilitate liquefaction.

The above compound is not particularly limited, but examples thereof include 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol (Tinuvin 571 manufactured by BASF), and 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-benzenepropionic acid, alkyl ester having 7 to 9 carbon atoms (Tinuvin 99-2 manufactured by BASF), which are most suitable for use in preventing wrinkles.

<Urethanization catalyst (D) containing metal component>
The urethanization catalyst (D) contains a metal component.

When using only a urethanization catalyst that does not contain a metal component, such as an amine catalyst, or when using a catalyst-free system that does not contain a urethanization catalyst (D) that contains a metal component, the triazole derivative (C) cannot coordinate to the metal that acts as a catalyst, and the effect of suppressing wrinkles due to cure shrinkage is not obtained, making it difficult to use. In addition, side reactions such as a foaming reaction (urea reaction) between moisture in the air and isocyanate are likely to proceed, and air bubbles can deteriorate the appearance of the coating film, or dangling chains can form instead of a uniform crosslinked structure, worsening the curing property and transparency, making it difficult to use.

The content of the urethane catalyst (D) containing a metal component in the urethane-forming composition (G) is 0.001% by mass or more and 0.5% by mass or less. Although not particularly limited, the content of the urethane catalyst (D) containing a metal component is preferably in the range of 0.001% by mass to 0.1% by mass, and more preferably in the range of 0.005% by mass to 0.07% by mass, because this improves moldability and tends to improve the appearance of the resulting urethane coating film.

If the content of the urethane catalyst (D) containing a metal component exceeds 0.5% by mass, the curing reaction will be too rapid, resulting in poor moldability, and wrinkles will be easily promoted, and the amount of triazole derivative (C) required to suppress wrinkles will be too large, resulting in poor compatibility and poor hardness and transparency of the resulting urethane, making it difficult to use.

The urethane catalyst (D) containing a metal component is not particularly limited as long as it is a compound containing a metal component and exhibits urethane-forming activity, but is preferably an organometallic compound containing one or more of the metals Fe, Sn, Zr, Ti, and Al. Among them, Sn catalysts, which are easily available and have low temperature dependency of catalytic activity, and one or more metal chelate catalysts such as Fe chelate catalysts, Zr chelate catalysts, Ti chelate catalysts, and Al chelate catalysts, which are easy to adjust in reactivity, are even more preferable because they tend to suppress wrinkles when a triazole derivative is added, and it is most preferable to use a Sn catalyst or an Fe chelate catalyst alone.

The Sn catalyst is not particularly limited, but examples include dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diversatate, and dibutyltin bis(acetylacetonate).

Although not particularly limited, examples of the Fe chelate catalyst include iron trisacetylacetonate, etc.; examples of the Zr chelate catalyst include zirconium tetraacetylacetonate, zirconium ethylacetoacetate, etc.; examples of the Ti chelate catalyst include titanium acetylacetonate, titanium ethylacetoacetate, etc.; and examples of the Al chelate catalyst include aluminum trisacetylacetonate, etc.

<Keto-enol tautomer compound (E)>
The urethane-forming composition (G) of the present invention preferably contains one or more keto-enol tautomer compounds, either ethyl acetoacetate or acetylacetone, since this makes it easier to adjust the catalytic activity and improve the moldability.

In the case where the keto-enol tautomer compound (E) is contained, the content thereof is preferably in a molar ratio (keto-enol tautomer compound/metal catalyst) of 10 times or more relative to the urethanization catalyst containing a metal component, since this tends to improve moldability, and more preferably in the range of 50 to 5,000 times. The content of the keto-enol tautomer compound (E) in the urethane-forming composition (G) is preferably in the range of 0.01% by mass to 20% by mass, and more preferably in the range of 0.5% by mass to 10% by mass.

<Acid Retarder (F)>
The urethane-forming composition (G) of the present invention preferably contains an acid retarder (F) because it is easy to suppress rapid gelation during drying, aging, and coating, and it is easy to stably suppress wrinkles and improve moldability, and is preferably, but not limited to, an acid having a pKa of 5.0 or less. Examples of such acids having a pKa of 5.0 or less include phosphorus-based acid retarders such as hydrochloric acid, nitric acid, phosphoric acid, and acidic phosphoric acid esters having 2 to 20 carbon atoms such as ethyl acid phosphate and 2-ethylhexyl acid phosphate, and among them, it is preferable to use a phosphorus-based acid retarder because it is easy to achieve a good balance between reactivity and physical properties. The content of the acid retarder (F) in the urethane-forming composition (G) is preferably in the range of 0.001% by mass to 1% by mass, and more preferably in the range of 0.005% by mass to 0.1% by mass. In addition, the pH of the urethane-forming composition (G) when an acid retarder is used is preferably in the range of 4 to 9. The pH of the urethane-forming composition (G) refers to the value measured by dispersing the composition at 7% by mass in a mixture of water and IPA at a weight ratio of 5:3 using a pH meter.

<Other additives>
The urethane-forming composition (G) of the present invention may contain additives such as antioxidants, chain extenders, antistatic agents, plasticizers, leveling agents, and other additives.

Among these, it is preferable to include a monofunctional compound in addition to the polyol (A) and the isocyanate compound (B) since this tends to improve moldability. As such a functional compound, it is preferable to use at least one of monofunctional alcohols, monofunctional isocyanates, and monofunctional amines, since this tends to improve moldability, and more preferably at least one of polyalkylene glycol monoalkyl ethers and polyalkylene glycol monofatty acid esters having a molecular weight of 100 to 1000. When a monofunctional compound is used, the content in the urethane-forming composition (G) is preferably in the range of 0.1% by mass to 5% by mass.

The chain extender is not particularly limited, and examples thereof include glycols such as ethylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerin, trimethylolpropane, pentaerythritol, and low molecular weight polyalkylene glycols having a molecular weight of 1000 or less; and polyvalent amines such as ethylenediamine, N-aminoethylethanolamine, piperazine, isophoronediamine, and xylylenediamine. Among these, polyvalent amines are preferred because they form urethane urea and are easy to use to obtain urethane with good physical properties.

Antistatic agents include, but are not limited to, alkali metal salts and ionic liquids, such as lithium salts such as lithium bis(trifluoromethanesulfonylimide), quaternary ammonium salts, imidazolium salts, phosphonium salts, and pyridinium salts.

The plasticizer is not particularly limited, but examples thereof include fatty acid esters, alicyclic esters, polyether esters, etc., such as epoxidized fatty acid esters, myristic acid esters, and terminal ester-modified compounds of polyalkylene glycols.

<Urethane-forming composition (G)>
The urethane-forming composition (G) according to one embodiment of the present invention is a urethane-forming composition (G) containing a polyol (A), an isocyanate compound (B), a triazole derivative (C), and a urethane-forming catalyst (D) containing a metal component, in which the content of the triazole derivative (C) is 0.1% by mass or more and 3.0% by mass or less, the content of the urethane-forming catalyst (D) is 0.5% by mass or less, and the molar ratio of the triazole derivative (C)/the urethane-forming catalyst (D) containing a metal component is 7 times or more. The raw materials such as the polyol (A) and the isocyanate compound (B) may be mixed and reacted in advance to form a urethane prepolymer (H).

Although not particularly limited, the urethane-forming composition (G) preferably has a viscosity at 25°C when uniformly dispersed in a range of 0.1 to 100 Pa·s, more preferably 1 to 30 Pa·s, in order to suppress wrinkles in the resulting urethane and to facilitate a transparent and good appearance. It is also preferable that the composition be liquid, with low liquid elasticity and high fluidity.

The preparation of the urethane-forming composition (G) is not particularly limited as long as it is a method capable of uniformly dispersing the raw materials contained in the urethane-forming composition (G), and various stirring methods known in the art can be used, such as a method of stirring using a stirrer. Examples of the stirrer include a general-purpose stirrer, a planetary mixer, a disperser disperser, a kneader, a mixer, a lab plastomill, and a planetary mixer. When all of the components of the urethane-forming composition (G) are liquid at the stirring temperature, a planetary mixer, a planetary mixer, a disperser disperser, or a revolving mixer is preferably used. In addition, operations such as heating, pressurization, and standing may be added as necessary to degas the mixture.

In the case where the urethane-forming composition (G) contains a urethane prepolymer (H) in which some of the raw materials used are mixed and reacted in advance at a certain ratio, various stirring methods known in the art can also be used for preparing the urethane prepolymer.

<Urethane prepolymer composition (I)>
A urethane prepolymer composition (I) according to one embodiment of the present invention is a urethane prepolymer composition (I) comprising a urethane prepolymer (H), a triazole derivative (C), and a urethanization catalyst (D) containing a metal component,
the urethane prepolymer (H) is a reaction product of at least a polyol (A) and a polyisocyanate (B) and has at least one hydroxyl group in one molecule;
the molar ratio (M _NCO /M _OH ) of the sum of NCO groups (M _NCO ) contained in the isocyanate (B) to the sum of hydroxyl groups (M _OH ) contained in the polyol (A) forming the urethane prepolymer (H) is less than 1.0,
The urethane prepolymer composition (I) is characterized in that the content of the triazole derivative (C) in the urethane prepolymer composition (I) is 0.1 mass% or more and 3 mass% or less, the content of the urethanization catalyst (D) is 0.5 mass% or less, and the molar ratio of the triazole derivative (C) to the urethanization catalyst (D) containing a metal component is 7 times or more.

When the urethane prepolymer (H) is formed in advance, the weight average molecular weight is preferably 1000 or more, since this makes it easier to suppress rapid cure shrinkage and improve moldability, and the resulting polyurethane is less likely to wrinkle and has a good coating appearance. In particular, the weight average molecular weight is preferably in the range of 5000 to 1,000,000, which makes it easier to achieve good fluidity and excellent moldability, and more preferably in the range of 10,000 to 500,000. In addition, the molecular weight distribution of the urethane prepolymer (H) is preferably 1.05 to less than 6.0, and more preferably 1.5 to less than 4.0, since the liquid has low elasticity regardless of viscosity and is easier to achieve good fluidity and excellent moldability. The weight average molecular weight and molecular weight distribution of the urethane prepolymer (H) can be measured in accordance with conventional methods using gel permeation chromatography (GPC).

When the urethane prepolymer (H) is formed in advance, the molar ratio (M _NCO /M _OH ) of the sum of the NCO groups (M _NCO ) of the isocyanate (B) to the sum of the hydroxyl groups (M _OH ) of the polyol (A) is less than 1.0. In particular, it is preferably 0.10 or more and 0.95 or less, and more preferably 0.15 or more and 0.80 or less. The ratio (M _NCO /M _OH ) represents a molar ratio. If the ratio (M _NCO /M _OH ) is 1.0 or more, the storage stability of the urethane prepolymer composition is likely to deteriorate, and a small amount of gelled matter or bubbles is likely to be generated in the urethane forming composition obtained using the composition, and the coating film is likely to have poor appearance such as bumps or foaming, so that the coating film appearance may deteriorate when the urethane is formed.

The average number of functional groups of the polyol (A) is preferably 1.9 or more, and more preferably 2 to 6, although not particularly limited thereto. A urethane-forming composition (G) having an average number of functional groups of 1.9 or more calculated from the number of functional groups and the molar ratio is preferred because it has excellent curing (solidification) properties when a polyurethane is obtained by curing in the reaction, and the polyurethane has even better mechanical properties.

When producing the urethane prepolymer (H), the polyol (A) and the isocyanate compound (B) are preferably dehydrated by vacuum heating or the like before use, but may be used without dehydration if this operation would be complicated.
The urethane prepolymer composition (I) is characterized in that the content of the triazole derivative (C) in the urethane prepolymer composition (I) is 0.1% by mass or more and 3% by mass or less, the content of the urethane-forming catalyst (D) in the urethane prepolymer composition (I) is 0.5% by mass or less, and the molar ratio of the triazole derivative (C) to the urethane-forming catalyst (D) containing a metal component is 7:1 or more. The preferred content, composition ratio, and liquid viscosity are in the same ranges as those in the urethane-forming composition (G).

<Urethane-forming composition solution (L)>
The urethane-forming composition (G) can be mixed with an organic solvent to form a urethane-forming composition solution (L) in order to facilitate handling or to obtain the desired viscosity and coatability.

At this time, the urethane-forming composition solution (L) contains the urethane-forming composition (G) and an organic solvent, and the concentration of the urethane-forming composition (G) in the urethane-forming composition solution (L) is 10% by mass or more and 95% by mass or less.

Examples of organic solvents include methyl ethyl ketone, ethyl acetate, butyl acetate, toluene, xylene, acetone, benzene, dioxane, acetonitrile, tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, dimethylformamide, etc. From the standpoint of solubility, boiling point of the organic solvent, etc., ethyl acetate, toluene, methyl ethyl ketone, or a mixture of these solvents is particularly preferred. These solvents can be added at any stage.

The concentration of the urethane-forming composition in the urethane-forming composition solution (L) is 10% by mass or more and 95% by mass or less, and preferably 30% by mass or more and 70% by mass or less. When the concentration is in this range, the urethane-forming composition solution (L) can be easily handled, for example, good coatability can be obtained when the solution is applied with a coater or the like.

The viscosity of the urethane-forming composition solution (L) at 25° C. is not particularly limited, but
The viscosity is preferably in the range of 0.1 to 100 Pa·s, and more preferably in the range of 1 to 30 Pa·s. In addition, it is preferable that the composition is in a liquid state, and that the liquid has low elasticity and high fluidity.
If the viscosity is within this range, the urethane-forming composition solution (L) can be easily handled, for example, good coatability can be obtained when the solution is applied with a coater or the like.

<Urethane Prepolymer Composition Solution (K)>
The urethane prepolymer composition (I) can be mixed with an organic solvent to form a urethane prepolymer composition solution (K) in order to facilitate handling or to obtain a desired viscosity or coatability.

At this time, the urethane prepolymer composition solution (K) contains a urethane prepolymer composition (I) and an organic solvent, and the concentration of the urethane-forming composition (G) in the urethane prepolymer composition solution (K) is 10% by mass or more and 95% by mass or less, or the urethane prepolymer composition solution (I) contains a urethane prepolymer composition and an organic solvent, and the concentration of the urethane prepolymer composition (I) in the urethane-forming composition solution (L) is 10% by mass or more and 95% by mass or less.

Examples of organic solvents include methyl ethyl ketone, ethyl acetate, butyl acetate, toluene, xylene, acetone, benzene, dioxane, acetonitrile, tetrahydrofuran, dimethyl sulfoxide, N-methylpyrrolidone, dimethylformamide, etc. From the standpoint of solubility, boiling point of the organic solvent, etc., ethyl acetate, toluene, methyl ethyl ketone, or a mixture of these solvents is particularly preferred. These solvents can be added at any stage.

The concentration of the urethane-forming composition in the urethane prepolymer composition solution (K) is 10% by mass or more and 95% by mass or less, and preferably 30% by mass or more and 70% by mass or less. When the concentration is in this range, the urethane prepolymer composition solution (K) can be easily handled, for example, good coatability can be obtained when the solution is applied with a coater or the like.

The viscosity of the urethane prepolymer composition solution (K) at 25°C is not particularly limited, but is preferably in the range of 0.1 to 100 Pa·s, and more preferably in the range of 1 to 30 Pa·s. It is also preferable that the solution is liquid, has low elasticity, and has high fluidity.

When the viscosity is within this range, the urethane prepolymer composition solution (K) can be easily handled, for example, providing good coatability when applied with a coater or the like.

The urethane prepolymer composition solution (K) can be made into a urethane-forming composition solution (L) by being combined with an isocyanate compound (J).

<Polyurethane (M)>
The polyurethane (M) can be obtained by reacting the urethane-forming composition (G) by various methods and curing (solidifying). The method for producing the polyurethane (M) is not particularly limited. For example, the polyurethane-forming composition (G) can be produced by carrying out a urethane-forming reaction or a urea-forming reaction at room temperature or a high temperature of 150° C. or less in the presence of a urethane-forming catalyst, a solvent, an antioxidant, a light stabilizer, a chain extender, a crosslinking agent, other additives, etc., as necessary.

In order to achieve good curability, the process may include a step of activating the composition at high temperature and a step of removing the solvent and additives, if necessary.
Here, since the urethane-forming composition (G) has remarkably excellent formability when applied with a coating machine or the like, a polyurethane (M) coating film or polyurethane sheet having a thin and uniform thickness can be obtained.

There are no particular limitations on the thickness of the polyurethane (M) coating film, but the thickness is preferably 1 μm or more and 1000 μm or less, and more preferably 5 μm or more and 300 μm or less, since this results in a particularly good appearance of the coating film.

The uses of polyurethane (M) are not particularly limited, and it can be used in any application where ordinary polyurethane is used, but it is particularly suitable for applications where mechanical properties and tackiness/adhesive properties are required. Specific examples of applications where polyurethane (M) can be used preferably include sealing materials for construction and civil engineering, adhesives such as elastic adhesives for construction, packing tapes and surface protection films, various pressure sensitive adhesives such as those for optical applications, paints, elastomers, waterproof coating materials, flooring materials, plasticizers, soft polyurethane foams, semi-rigid polyurethane foams, and rigid polyurethane foams.

Among these, polyurethanes are particularly preferred for use as sealants, paints, pressure sensitive adhesives, and bonding agents, as they are required to have high mechanical properties and adhesive properties, as well as ease of application and coating.

The present invention will be described in more detail below with reference to examples, but the present invention should not be construed as being limited to the following examples unless it exceeds the gist of the invention. The raw materials and evaluation methods used in the following examples and comparative examples are as follows.
(Raw Material 1) Polyol A used in the Examples and Comparative Examples
Polyol A1: Trifunctional polypropylene/polyethylene glycol with a molecular weight of 3,400 (ADEKA Polyether GR3308 manufactured by ADEKA Corporation)
Polyol A2: Bifunctional polypropylene glycol having a molecular weight of 2000 (Sanyo Chemical Industries, Ltd., Sannix PP2000)
Polyol A3: Polyester polyol with molecular weight of 1000 (Nippolan 4009, manufactured by Tosoh Corporation)
All of the raw material polyols were dehydrated before use.
(Raw Material 2) Isocyanate Compounds (B) and (J) Used in the Examples and Comparative Examples
Isocyanate compounds B1 and J1: Isocyanurate modified hexamethylene diisocyanate (Coronate HXR manufactured by Tosoh Corporation)
Isocyanate compound B2: Trimethylolpropane adduct modified tolylene diisocyanate (Coronate L manufactured by Tosoh)
(Raw Material 3) Triazole Derivative (C) and Compound (CC) Used in the Examples and Comparative Examples
Triazole derivative C1: 2-(2H-benzotriazol-2-yl)-6-dodecyl-4-methylphenol (BASF Tinuvin 571, liquid)
Triazole derivative C2: 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-benzenepropionic acid, alkyl ester having 7 to 9 carbon atoms (BASF Tinuvin 99-2, liquid)
Triazole derivative C3: 1-[N,N-bis(2-ethylhexyl)aminomethyl]benzotriazole (BT-LX, liquid, manufactured by Johoku Chemical Industry Co., Ltd.)
Triazole derivative C4: 6-(2-benzotriazolyl)-4-tert-octyl-6'-tert-butyl-4'-methyl-2,2'-methylenebisphenol (JAST-500, powder, manufactured by Johoku Chemical Industry Co., Ltd.)
Compound CC1: 1,2-dimethylimidazole Compound CC2: N,N'-dimethylpiperazine Compound CC3: dibutylhydroxytoluene (BHT)
(Raw Material 4) Metal-containing urethanization catalyst (D) and non-metallic urethanization catalyst (DC) used in the examples and comparative examples
Urethane catalyst D1: dioctyltin dilaurate Urethane catalyst D2: iron trisacetylacetonate Urethane catalyst DC1: triethylenediamine (raw material 5) additive Ketoenol tautomer compound E1: acetylacetonate acid retarder F1: 2-ethylhexyl acid phosphate Monofunctional compound 1: polyethylene glycol monomethyl ether #400

(Preparation of urethane-forming composition (G) and urethane-forming composition solution (L))
In the examples and comparative examples, a predetermined amount of each raw material (for example, polyol (A), isocyanate compound (B), triazole derivative (C), urethanization catalyst (D), and other raw materials) was placed in a 50 ml sample bottle, and the mixture was stirred and defoamed at room temperature using a planetary centrifugal mixer to obtain a urethane-forming composition. When a prepolymer (H) was used, the prepolymer was synthesized in advance, and the weight average molecular weight and molecular weight distribution (weight average molecular weight Mw/number average molecular weight Mn) were measured by gel permeation chromatography before use.

The rotating and revolving mixer used was a Thinky Thinker ARE-310. Rotation was performed for 5 minutes at 2000 rpm and revolution for 5 minutes at 2200 rpm to produce the urethane-forming composition (G) or urethane-forming composition solution (L). The viscosity was measured immediately afterwards using a Brookfield viscometer, and this was recorded as the viscosity. Performance evaluation was then performed.

During this process, the properties were evaluated according to the following criteria.
(Property evaluation)
<Viscosity>
Viscosity 〇 (good): 0.1 to 30 Pa·s, and the liquid can flow 1 cm within 3 seconds when tilted 180°. Viscosity △ (possible): Over 30 Pa·s, or the liquid can be tilted 180° and requires more than 3 seconds to flow 1 cm (high elasticity)
<Weight average molecular weight>
Weight average molecular weight 〇 (good): 10,000 to 500,000 Weight average molecular weight △ (possible): more than 500,000 <Molecular weight distribution>
Molecular weight distribution 〇 (good): 1.05 to less than 6.0 Molecular weight distribution △ (acceptable): 6.0 or more

(Performance evaluation)
The urethane-forming composition (G) was applied onto a PET film having a thickness of 38 μm using a Baker-type applicator so that the thickness after drying would be 100 μm or less. The film was then placed in an oven set at 130° C. for 3 minutes to volatilize the solvent, and allowed to stand for 1 week in an environment of 23° C. and a relative humidity of 50% to obtain a coating film.

In this process, the performance of the urethane-forming composition was evaluated according to the following criteria.
<Moldability (coatability, thickness unevenness)>
⊚ (Passing formability): When a molded sheet with no coating unevenness and a uniform thickness with a difference in thickness between the edges and center of 3% or less is obtained.
○ (Pass moldability): Slight coating unevenness is visible to the naked eye, or there is slight thickness unevenness with the difference in thickness between the edge and center exceeding 3% and not exceeding 5%.
× (failed formability): The liquid flows during application or drying (making uniform forming difficult), or there is clear thickness unevenness exceeding 5% between the edges and center.
<Curability>
◎ (Passed curing): When the sticky feeling disappears after being removed from the oven and returned to room temperature.
◯ (Curability Passed): When removed from the oven, slight tack remains when touched with the fingers, and the sticky feeling almost disappears when left to stand for 7 days in an environment of 23° C. and a relative humidity of 50%.
XX (failed curing): After being removed from the oven, the product still felt sticky even after being left to stand for 7 days in an environment of 23° C. and 50% relative humidity (poor curing).
<Appearance of coating film>
◎ (Paint film appearance passes): The obtained urethane has no wrinkles, is visually free of bumps and is smooth.
○ (Paint film appearance passed): The obtained urethane was free of wrinkles and bubbles, but had slight bumps and was therefore inferior in smoothness, or had poor transparency when visually examined.
× (coating appearance failed): Air bubbles were generated in the obtained urethane, and the coating appearance was poor.
XX (coating appearance failed): The coating appearance was poor due to wrinkles occurring in the obtained urethane due to cure shrinkage.
<Coating film properties>
◎ (Paint film physical properties pass): No tack when evaluated by touching with fingers.
◯ (Paint film physical properties pass): When evaluated by touching with fingers, there is a slight sense of tack.
XX (coating film physical properties fail): If there is tack when evaluated by touching with fingers (insufficient hardness).

Compositions that passed all the evaluation criteria were judged to be urethane-forming compositions that contribute to the formation of polyurethane with excellent coating film appearance and coating film physical properties, and that have good moldability and curability, do not require long periods of time for coating and curing, and have high productivity.

<Examples and Comparative Examples>
Example 1 is a urethane-forming composition (G1) containing 100 parts by weight of polyol (A1), 1 part by weight of triazole derivative (C1), 0.02 parts by weight of urethanization catalyst (D1) containing metal, 3.0 parts by weight of ketoenol tautomer compound (E1), 0.03 parts by weight of acid retarder (F1), and the amount of hydroxyl groups (M _OH ) derived from (A1) and the amount of isocyanate groups (M _NCO ) derived from (B1) are mixed with isocyanate compound (B1) so that the molar ratio is M _NCO of (B1) / M _OH of (A1) = 1.05. Table 1 shows the results of Example 1, but the urethane-forming composition (G1) has good coating properties and curing properties, and the coating film of polyurethane (M1) obtained from the composition (G1) has excellent coating film appearance and coating film physical properties without appearance defects such as wrinkles and tack.

Comparative Example 1 is a urethane-forming composition (GC1) that does not contain the triazole derivative (C1) in Example 1. Since this composition (GC1) does not contain the triazole derivative (C1), wrinkles occur when it dries, a uniform molded product cannot be obtained, and moldability is poor. In addition, polyurethane (MC1) obtained from this composition (GC1) has no tack when touched with fingers and exhibits hardness, but has wrinkles and other issues that make it difficult to use because it is not smooth and has a poor appearance.

Example 2 is a urethane-forming composition (G2) containing 100 parts by weight of a polyol (A2), 1.5 parts by weight of a triazole derivative (C1), 0.015 parts by weight of a metal-containing urethanization catalyst (D1), 3.0 parts by weight of a keto-enol tautomer compound (E1), and 0.03 parts by weight of an acid retarder (F1), and isocyanate compound (B2) mixed therein such that the amount (M _OH ) of hydroxyl groups derived from (A1) and the amount (M _NCO ) of isocyanate groups derived from (B2) are in a molar ratio of M _NCO of (B2) /M _OH of (A1) = 1.05.

The urethane-forming composition (G2) had good coatability and curability, and the polyurethane (M2) coating obtained from the composition (G2) had excellent coating appearance and physical properties, being free of appearance defects such as wrinkles and tackiness.

Comparative Example 2 is a urethane-forming composition (GC2) that does not contain the urethane catalyst (D1) of Example 2. Since this composition (GC2) does not contain the urethane catalyst (D1), the liquid flows when dried, resulting in poor moldability and poor curing properties, and the polyurethane (MC2) obtained from this composition (GC2) was very tacky to the touch, had poor coating properties, and also had poor coating appearance, making it difficult to use.

Example 3 is a urethane-forming composition (G3) in which the amount of triazole derivative (C1) was reduced to 0.4 parts by weight and the amount of urethane catalyst (D1) was increased to 0.05 parts by weight compared to Example 1. The urethane-forming composition (G3) had good coatability and curability, and the coating of polyurethane (M3) obtained from the composition (G3) had excellent coating appearance and physical properties, with no appearance defects such as wrinkles or tack.

Comparative Example 3 is a urethane-forming composition (GC3) in which the amount of triazole derivative (C1) was further reduced to 0.07 parts by weight compared to Example 3, and the molar ratio of triazole derivative (C1) to urethane catalyst (D1) was reduced to 2.6.

The ratio of triazole derivative (C1) to urethane catalyst (D1) in this composition (GC3) was less than 7 times, so it was not possible to suppress cure shrinkage during urethane formation, and wrinkles occurred in the coating film, causing poor appearance of the coating film and making it difficult to use.

Example 4 is a urethane-forming composition (G4) containing 100 parts by weight of a polyol (A3), 2.9 parts by weight of a triazole derivative (C2), 0.03 parts by weight of a metal-containing urethanization catalyst (D1), 5.0 parts by weight of a keto-enol tautomer compound (E1), and 0.03 parts by weight of an acid retarder (F1), and isocyanate compound (B2) is mixed therein such that the amount (M _OH ) of hydroxyl groups derived from (A3) and the amount (M _NCO ) of isocyanate groups derived from (B2) are in a molar ratio of M _NCO of (B2) /M _OH of (A3) = 1.05.

The urethane-forming composition (G4) had a thickness difference from Example 2 due to the high content of liquid triazole, but the moldability and curability were generally good, and the coating of polyurethane (M4) obtained from the composition (G4) had no appearance defects such as wrinkles, was generally free of tack, and had excellent coating appearance and physical properties.

Comparative Example 4 is a urethane-forming composition (GC4) in which the amount of triazole derivative (C2) was further increased to 4.0 parts by weight compared to Example 4. Since the content of triazole derivative (C1) in the urethane-forming composition in this composition (GC4) exceeds 3.0 mass %, it is possible to suppress wrinkles during curing, but curing takes time, and the resulting polyurethane (MC4) is also a composition that is difficult to use because it has strong tack and poor coating properties.

Example 5 is a urethane-forming composition (G5) containing 50 parts by weight of a polyol (A1), 50 parts by weight of a polyol (A2), 0.5 parts by weight of a triazole derivative (C2), 0.02 parts by weight of a metal-containing urethanization catalyst (D1), and 0.03 parts by weight of an acid retarder (F1), in which an isocyanate compound (B1) was mixed so that the amount (M _OH ) of hydroxyl groups derived from (A1) and (A2) and the amount (M _NCO ) of isocyanate groups derived from (B1) were M _NCO of (B1) /M _OH of (A1) and (A2) = 1.05 in terms of molar ratio.

The urethane-forming composition (G5) does not contain the keto-enol tautomer compound (E1), and therefore is slightly inferior in moldability to Example 3. However, the moldability and curability are generally good, and the coating film of the polyurethane (M5) obtained from the composition (G5) is free of appearance defects such as wrinkles, is free of tack, and has excellent coating appearance and physical properties.

Comparative Example 5 is a urethane-forming composition (GC5) that does not contain the triazole derivative (C2) of Example 5, but instead reduces the amount of urethane catalyst (D1) to 0.001 parts by weight to adjust the reactivity.

The urethane-forming composition (GC5) does not contain triazole derivative (C), so wrinkles occur when it dries even if the amount of the urethane catalyst (D1) is reduced. The polyurethane (MC5) obtained from the composition (GC5) has no tack when touched with the fingers and exhibits hardness, but has wrinkles and other imperfect smoothness, resulting in a poor appearance, making it difficult to use.

Example 6 is a urethane-forming composition (G6) that does not contain the acid retarder (F1) for adjusting the reactivity compared to Example 5, but instead contains an increased amount of triazole derivative (C2) to 1.0 part by weight.

The urethane-forming composition (G6) does not contain the monofunctional compound (1), and therefore is slightly inferior in moldability to Example 5. However, the moldability and curability are generally good, and the coating of the polyurethane (M6) obtained from the composition (G6) is wrinkle-free and has slight coating unevenness, but generally has a good coating appearance and exhibits excellent coating physical properties.

All of Examples 1 to 6 and Comparative Examples 1 to 5 shown in Table 1 had a low viscosity of less than 30 Pa·s and presented no problems with handling.

Example 7 is a urethane-forming composition (G7) in which the urethane-forming catalyst (D1) with Sn as the central metal was changed to a urethane-forming catalyst (D2), which is a metal chelate catalyst, in comparison with Example 1. The urethane-forming composition (G7) had good coatability and curability, and the coating of polyurethane (M7) obtained from the composition (G7) had excellent coating appearance and physical properties, being free of appearance defects such as wrinkles and tackiness.

Example 8 is a urethane-forming composition (G8) in which the triazole derivative (C1) in Example 7 was changed to (C2) and the amount of the urethane catalyst (D2) was reduced to 0.005 parts by weight. The urethane-forming composition (G8) had good coatability and curability, and the coating of polyurethane (M8) obtained from the composition (G8) had excellent coating appearance and physical properties, being free of appearance defects such as wrinkles and tackiness.

Example 9 is a urethane-forming composition (G9) in which the triazole derivative (C1) having a phenolic hydroxyl group in Example 1 is changed to a triazole derivative (C3) having no phenolic hydroxyl group.

The urethane-forming composition (G9) had good coatability and curability, and because it contained a triazole derivative, the coating of polyurethane (M9) obtained from the composition (G9) was wrinkle-free and had slight coating unevenness, but the coating generally had a good appearance and excellent coating physical properties.

Example 10 is a urethane-forming composition (G10) in which the liquid triazole derivative (C1) in Example 1 is replaced with a powder triazole derivative (C4), and the amount of the urethane-forming catalyst (D1) is changed from 0.02 parts by weight to 0.005 parts by weight, increasing the molar ratio of the triazole derivative to the urethane-forming catalyst by 297.5 times.

The urethane-forming composition (G10) had good coatability and curability, and because it contained a powdered triazole derivative, the coating of polyurethane (M10) obtained from this composition (G10) was wrinkle-free and slightly less smooth due to a small amount of bumps, but the coating generally had a good appearance, was almost free of tack, and had generally excellent coating properties.

Comparative Example 6 is a urethane-forming composition (GC6) in which 1.0 part by weight of triazole derivative (C1) in Example 7 is changed to 1.0 part by weight of compound (CC1), which is an imidazole derivative that is a nitrogen-based heterocycle. This composition (GC6) does not contain triazole derivative (C) but does contain an imidazole derivative, so in addition to wrinkles, air bubbles are generated when drying, and the composition hardens quickly, so a uniform molded product cannot be obtained, and the moldability is poor. In addition, polyurethane (MC6) obtained from this composition (GC6) has no tack when touched with fingers and exhibits hardness, but has wrinkles and other issues that make it difficult to use because it is not smooth and has a poor appearance.

Comparative Example 7 is a urethane-forming composition (GC7) in which 1.0 part by weight of triazole derivative (C4) in Example 10 is changed to 1.0 part by weight of compound (CC2), which is a piperazine derivative that is a nitrogen-based heterocycle. This composition (GC7) does not contain triazole derivative (C) but contains a piperazine derivative, so the curability is generally good, but when dried, wrinkles and bubbles are generated, and a molded product cannot be obtained, resulting in poor moldability. In addition, polyurethane (MC7) obtained from this composition (GC7) has no tack when touched with fingers and exhibits hardness, but has wrinkles and other imperfect smoothness and a poor appearance, making it difficult to use.

Comparative Example 8 is a urethane-forming composition (GC8) in which 1.0 part by weight of the triazole derivative (C4) in Example 10 is changed to 1.0 part by weight of a compound (CC3) having a phenolic hydroxyl group but not containing a triazole structure.

Since the composition (GC8) does not contain triazole derivative (C), wrinkles occur when it dries, a uniform molded product cannot be obtained, and the moldability is poor. In addition, the polyurethane (MC8) obtained from the composition (GC8) has no tack when touched with the fingers and exhibits hardness, but has wrinkles and other issues that make it difficult to use because it is not smooth and has a poor appearance.

Comparative Example 9 is a urethane-forming composition (GC9) in which, compared to Example 8, 0.005 parts by weight of the urethane catalyst (D2) containing a metal component was replaced with 0.07 parts by weight of an amine-based catalyst (DC1) containing no metal component, and the amount of triazole derivative (C2) was increased.

This composition (GC9) does not contain the urethane catalyst (D2) containing a metal component, but contains an amine catalyst, which causes slight liquid flow and a slight delay in curing, resulting in slightly inferior moldability and curing properties. The polyurethane (MC9) obtained from this composition (GC9) had poor coating appearance due to air bubbles, was tacky, and had insufficient hardness, making it difficult to use.

All of Examples 7 to 10 and Comparative Examples 6 to 9 shown in Table 2 had a low viscosity of less than 30 Pa·s and presented no problems with handling.

In Example 11, 100 parts by weight of polyol (A1), 0.5 parts by weight of monofunctional compound (1), and isocyanate compound (B1) were mixed and reacted in the presence of 0.02 parts by weight of urethanization catalyst (D1) so that the amount (M _OH ) of hydroxyl groups derived from (A1) and monofunctional compound (1) and the amount (M _NCO ) of isocyanate groups derived from (B1) were M _NCO of (B1) / M _OH of (A1) and monofunctional compound (1) = 0.35 in terms of molar ratio, to prepare prepolymer (H11).

The urethane forming composition (G11) is a mixture of the urethane prepolymer composition (I11) containing the prepolymer (H11), 1.0 part by weight of the triazole derivative (C1), 3.0 parts by weight of the keto-enol tautomer compound (E1), and 0.03 parts by weight of the acid retarder (F1), and the amount of hydroxyl groups (M _OH ) derived from (A1) and the monofunctional compound (1) and the amount of isocyanate groups (M _NCO ) derived from (B1) are in a molar ratio of M _NCO of (B1) / M _OH of (A1) and the monofunctional compound (1) = 0.70, and the urethane forming composition solution (L11) contains ethyl acetate as an organic solvent. The concentration of (G11) in the solution (L11) is 30%.

The urethane-forming composition solution (L11) had a low solution viscosity of less than 30 Pa·s, a prepolymer weight average molecular weight of 500,000 or less, and a low molecular weight distribution of 1.5 or more and less than 6.0, resulting in solution properties with excellent handleability.

The results of Example 11 are shown in Table 3. The urethane-forming composition solution (L11) had good coatability and curability, and the coating of polyurethane (M11) obtained from the composition solution (L11) had excellent coating appearance and physical properties, being free of appearance defects such as wrinkles and tackiness.

In Example 12, 75 parts by weight of polyol (A1), 25 parts by weight of polyol (A2), 5 parts by weight of monofunctional compound (1), and isocyanate compound (B2) were mixed and reacted in the presence of 0.02 parts by weight of urethanization catalyst (D1) so that the amount of hydroxyl groups (M _OH ) derived from (A1), (A3), and monofunctional compound (1) and the amount of isocyanate groups (M _NCO ) derived from (B2) were M _NCO of (B2) / M _OH of (A1), (A3), and monofunctional compound (1) = 0.35 in terms of molar ratio, to prepare prepolymer (H12).

The urethane forming composition (G12) is a mixture of the urethane prepolymer composition (I12) containing the prepolymer (H12), 1.0 part by weight of the triazole derivative (C2), 3.0 parts by weight of the ketoenol tautomer compound (E1), and 0.03 parts by weight of the acid retarder (F1), and the amount of hydroxyl groups (M _OH ) derived from (A1), (A3), and the monofunctional compound (1) and the amount of isocyanate groups (M _NCO ) derived from (B2) are in a molar ratio of M _NCO of (B2) / M _OH of (A1), (A3), and the monofunctional compound (1) = 0.70, and the urethane forming composition solution (L12) contains ethyl acetate as an organic solvent. The concentration of (G12) in the solution (L12) is 70%.

The urethane-forming composition solution (L12) had a low solution viscosity of less than 30 Pa·s, a prepolymer weight average molecular weight of 500,000 or less, and a low molecular weight distribution of 1.5 or more and less than 6.0, resulting in solution properties with excellent handleability.

The results of Example 12 are shown in Table 3. The urethane-forming composition solution (L12) had good coatability and curability, and the coating of polyurethane (M12) obtained from the composition solution (L12) had excellent coating appearance and physical properties, being free of appearance defects such as wrinkles and tackiness.

In Example 13, 100 parts by weight of a polyol (A1) and an isocyanate compound (B1) were mixed and reacted in the presence of 0.005 part by weight of a urethanization catalyst (D1) so that the amount (M _OH ) of hydroxyl groups derived from (A1) and the amount (M _NCO ) of isocyanate groups derived from (B1) were in a molar ratio of M _NCO of (B1) /M _OH of (A1) = 0.52, thereby preparing a prepolymer (H13).

The urethane-forming composition (G13) contains the above prepolymer (H13) and a urethane prepolymer composition (I13) containing 1.0 part by weight of a triazole derivative (C3), and is mixed with an isocyanate compound (J1) so that the amount of hydroxyl groups (M _OH ) derived from (A1) and the amount of isocyanate groups (M _NCO ) derived from (B1) are M _NCO of (B1) / M _OH of (A1) = 0.53 in molar ratio, and the urethane-forming composition solution (L13) contains methyl ethyl ketone as an organic solvent. The concentration of (G13) in the solution (L13) is 60%.

The urethane-forming composition solution (L13) had a prepolymer weight-average molecular weight of over 500,000 and a high molecular weight distribution of 6.0 or more, so the fluidity of the solution was somewhat low, and although it was usable, the solution properties made it somewhat difficult to handle.

The results of Example 13 are shown in Table 3. The urethane-forming composition solution (L13) had generally good coatability and curability, and the coating of polyurethane (M13) obtained from the composition solution (L13) had no wrinkles and was slightly less smooth, but generally had a good coating appearance and was free of tack, providing excellent coating physical properties.

Comparative Example 10 is a urethane-forming composition (GC10) in which the triazole derivative (C1) mixed after the prepolymer formation is replaced with a compound (CC1) that does not contain a triazole structure, as compared to Example 11, and a urethane-forming composition solution (LC10) that contains ethyl acetate as an organic solvent. The concentration of (GC10) in the solution (LC10) is 50%.

The composition solution (LC10) does not contain the triazole derivative (C1) but does contain the imidazole derivative, so in addition to wrinkles, air bubbles are generated when it dries, and a uniform molded product cannot be obtained, resulting in poor moldability. In addition, the polyurethane (MC10) obtained from the composition solution (LC10) had no tack when touched with the fingers and exhibited hardness, but was not smooth due to wrinkles and had a poor appearance, making it difficult to use.

Comparative Example 11 is a urethane-forming composition (GC11) in which the triazole derivative (C1) mixed after the prepolymer formation is replaced with a compound (CC3) having a phenolic hydroxyl group but not a triazole structure, and a urethane-forming composition solution (LC11) containing ethyl acetate as an organic solvent. The concentration of (GC11) in the solution (LC11) is 50%.

Since the composition solution (LC11) does not contain the triazole derivative (C1), wrinkles occur when it dries, a uniform molded product cannot be obtained, and the moldability is poor. In addition, the polyurethane (MC11) obtained from the composition solution (LC11) has no tack when touched with the fingers and exhibits hardness, but has wrinkles and other issues that make it difficult to use because it is not smooth and has a poor appearance.

Comparative Example 12 is a urethane-forming composition (GC12) that does not contain the urethane-forming catalyst (D1) having a metal component, as compared to Example 11, and a urethane-forming composition solution (LC12) that contains ethyl acetate as an organic solvent. The concentration of (GC12) in the solution (LC12) is 50%. Since the composition (GC12) does not contain the urethane-forming catalyst (D1), the curing properties are significantly poor, and the polyurethane (MC12) obtained from the composition (GC12) has an opaque coating appearance, is very tacky when touched with fingers, and has poor coating properties, making it difficult to use.

All of the compositions used in the examples of the present invention had a pH in the range of 4 to 9, and exhibited good liquid properties that were low corrosive and tended to exhibit good curing properties.

As shown in the above examples, the urethane-forming composition developed in this study has excellent moldability when applied, dried, and cured using a coating machine, and can suppress deterioration of the coating film appearance due to wrinkles, air bubbles, etc., without impairing curing properties.

Furthermore, by reacting with an isocyanate compound, it is possible to obtain a polyurethane that has little tack and good physical properties such as hardness. By taking advantage of this characteristic, it has been shown that the polyurethane obtained from the urethane-forming composition can be suitably used for sealing materials, paints, pressure sensitive adhesives, and adhesives.

Claims (11)

A urethane-forming composition (G) comprising a polyol (A), a polyisocyanate compound (B), a triazole derivative (C), a urethanization catalyst (D) containing a metal component, and one or more keto-enol tautomer compounds (E) of ethyl acetoacetate or acetylacetone, wherein the content of the triazole derivative (C) in the urethane-forming composition (G) is 0.1% by mass or more and 3.0% by mass or less, the content of the urethanization catalyst (D) is 0.001% by mass or more and 0.5% by mass or less, the content of the keto-enol tautomer compound (E) is 0.5% by mass or more and 10% by mass or less, and the molar ratio of the triazole derivative (C)/the urethanization catalyst (D) is 7 times or more,
the molar ratio of the keto-enol tautomer compound (E) to the urethanization catalyst (D) is in the range of 50 to 5000 times;
The urethane-forming composition (G) comprises an acid retarder (F) in the urethane-forming composition (G). A urethane prepolymer composition (I) comprising a urethane prepolymer (H), a triazole derivative (C), a urethanization catalyst (D) containing a metal component, and one or more keto-enol tautomer compounds (E) of ethyl acetoacetate and acetylacetone,
the urethane prepolymer (H) is a reaction product of at least a polyol (A) and a polyisocyanate compound (B) and has at least one hydroxyl group in one molecule;
a molar ratio (MNCO/MOH) of the sum of the NCO groups (MNCO) contained in the polyisocyanate compound (B) to the sum of the hydroxyl groups (MOH) contained in the polyol (A) forming the urethane prepolymer (H) is less than 1.0,
The urethane prepolymer composition (I) has a content of triazole derivative (C) of 0.1 mass% or more and 3.0 mass% or less, a content of urethanization catalyst (D) of more than 0 mass% and 0.5 mass% or less, a content of keto-enol tautomerization compound (E) of 0.5 mass% or more and 10 mass% or less, a molar ratio of triazole derivative (C)/urethanization catalyst (D) containing a metal component is 7 times or more, and a molar ratio of keto-enol tautomerization compound (E)/urethanization catalyst (D) is in the range of 50 times to 5,000 times. The urethane prepolymer composition (I) according to claim 2, characterized in that the triazole derivative (C) is a benzotriazole derivative. The urethane prepolymer composition (I) according to claims 2 and 3, characterized in that the benzotriazole derivative has one or more phenolic hydroxyl groups. The urethane prepolymer composition (I) according to claims 2 to 4, wherein the molar ratio of the triazole derivative (C) to the urethane catalyst (D) containing the metal component is 25 to 200 times. The urethane prepolymer composition (I) according to any one of claims 2 to 5, characterized in that the urethane prepolymer composition (I) contains an acid retarder (F). A urethane prepolymer composition solution (K) comprising the urethane prepolymer composition (I) according to any one of claims 2 to 6 and an organic solvent,
The urethane prepolymer composition solution (K) is characterized in that a concentration of the urethane prepolymer composition (I) in the urethane prepolymer composition solution (K) is 10% by mass or more and 95% by mass or less. A urethane-forming composition (G) comprising the urethane prepolymer composition (I) according to any one of claims 2 to 6 and a polyisocyanate compound (J). A urethane-forming composition solution (L) comprising the urethane prepolymer composition solution (K) according to claim 7 and a polyisocyanate compound (J). Polyurethane (M) which is a reaction product of the urethane-forming composition (G) described in claim 8 or the urethane-forming composition (G) in the urethane-forming composition solution (L) described in claim 9. A polyurethane sheet made of the polyurethane (M) according to claim 10.