Compositions containing zinc phenylphosphonate salt and zinc phosphonate complex, process for their production, their use as crystallization nucleating agents and moisture-curable hot melt polyurethane resin adhesives

Abstract

A method for producing a composition containing a zinc salt of phenylphosphonic acid and a zinc phosphonate complex, the method including a step of simultaneously reacting phenylphosphonic acid represented by formula (1) and a phosphonate represented by formula (2) with a zinc compound, in formula (2), R1 represents an alkyl group, R2 represents an alkylene group, and n represents an integer of 1 or more, when n is an integer of 2 or more, a plurality of R2 are optionally the same as or different from each other, and R 2 represents an ethylene group.

Description

Technical Field

[0001] This disclosure relates to a composition containing zinc phenylphosphonate salt and zinc phosphate complex, a method for producing the same, its use as a crystal nucleating agent, and a moisture-curable hot melt polyurethane resin adhesive. Background Technology

[0002] Moisture-curable hot-melt polyurethane resins offer excellent adhesion and allow for relatively flexible adjustment of bonding times, making them suitable for adhesives used in bonding processes requiring continuous production and molding (such as sealing operations), and applicable to a wide range of fields. However, in applications such as decorative panels for wood packaging requiring initial strength, and in electrical / electronic components and automotive parts requiring continuous production on high-speed production lines, there may be issues where parts proceed to the next process before the polyurethane resin has adequately cooled and cured.

[0003] To address the aforementioned issues, metal salts of phenylphosphonic acid compounds have been incorporated into polyurethane resins as nucleating agents to shorten curing time. For example, Japanese Unexamined Patent Application Publication No. 2012-177016 discloses a moisture-curable hot-melt polyurethane resin adhesive containing an isocyanate-terminated polyurethane prepolymer obtained by reacting a polyol and a polyisocyanate in the presence of a metal salt of an aromatic phosphonic acid as a nucleating agent. Invention Overview

[0005] According to the inventors' research, when using metal salts of aromatic phosphonic acids as nucleating agents, there is still room for further reduction in the curing time of wet-curable hot-melt polyurethane resins.

[0006] In view of these circumstances, one aspect of the present invention aims to provide a composition and a method for producing the same, said composition being suitably used as a nucleating agent that can further shorten the curing time of a wet-curable hot-melt polyurethane resin. Another aspect of the present invention aims to provide a wet-curable hot-melt polyurethane resin adhesive with a further shortened curing time.

[0007] The inventors of this invention have discovered that by using specific phenylphosphonic acid and specific phosphate esters as raw materials and reacting them simultaneously with a zinc compound, a composition containing a specific zinc phenylphosphonic acid salt and a specific zinc phosphate ester complex can be obtained, and this composition can be suitably used as a crystallizing nucleating agent that can further shorten the curing time of wet-curable hot-melt polyurethane resins.

[0008] The present invention includes the following aspects.

[0009] [1] A method for producing a composition containing a zinc phenylphosphonate salt and a zinc phosphate complex, the method comprising the step of simultaneously reacting a phenylphosphonic acid represented by formula (1) and a phosphate ester represented by formula (2) with a zinc compound:

[0010]

[0011]

[0012] In equation (2), R 1 R represents an alkyl group. 2 The denoting alkylene group is denoted by , and n represents an integer greater than or equal to 1. When n is an integer greater than or equal to 2, multiple R groups are considered. 2 They can be the same as each other or different from each other, and R 2 At least one of them represents ethylene.

[0013] [2] According to the method for producing the composition described in [1], the molar ratio of the amount of phosphate ester represented by formula (2) to the amount of phenylphosphonic acid represented by formula (1) is from 1 / 99 to 60 / 40.

[0014] [3] A composition comprising a zinc phenylphosphonate salt represented by formula (3) and a zinc phosphate complex represented by formula (4):

[0015]

[0016]

[0017] In equation (4), R 1 R represents an alkyl group. 2 R represents an alkylene group, and n represents an integer greater than or equal to 1. When n is an integer greater than or equal to 2, multiple R2 groups can be identical or different from each other, and R 2 At least one of them represents ethylene.

[0018] [4] According to the composition of [3], the molar ratio of the amount of the zinc phosphate complex represented by formula (4) to the amount of the zinc phenylphosphonate salt represented by formula (3) is from 1 / 99 to 60 / 40.

[0019] [5] Use of the composition according to [3] or [4] as a crystallizing nucleating agent.

[0020] [6] A moisture-curable hot-melt polyurethane resin adhesive, wherein the moisture-curable hot-melt polyurethane resin adhesive contains an isocyanate-terminated polyurethane prepolymer, a zinc phenylphosphonate salt represented by formula (3), and a zinc phosphate complex represented by formula (4):

[0021]

[0022]

[0023] In equation (4), R1 represents an alkyl group, R2 represents an alkylene group, and n represents an integer greater than or equal to 1. When n is an integer greater than or equal to 2, multiple R2s can be the same or different from each other, and R 2 At least one of them represents ethylene.

[0024] [7] The wet-curable hot-melt polyurethane resin adhesive according to [6], wherein the molar ratio of the amount of phosphate ester represented by formula (4) to the amount of phenylphosphonic acid represented by formula (3) is 1 / 99 to 60 / 40.

[0025] [8] According to [6] or [7], the total amount of the zinc phenylphosphonate salt represented by formula (3) and the zinc phosphate complex represented by formula (4) is 0.1 to 10 by mass based on the total amount of the wet-curable hot-melt polyurethane resin adhesive.

[0026] One aspect of the invention provides a composition and a method for producing the same, said composition being suitably used as a crystallizing nucleating agent that can further shorten the curing time of a wet-curable hot-melt polyurethane resin. Another aspect of the invention provides a wet-curable hot-melt polyurethane resin adhesive with a further shortened curing time.

[0027] Description of the implementation plan

[0028] The embodiments of the present invention are described in detail below. One embodiment of the present invention is a method for producing a composition containing a zinc phenylphosphonate salt and a zinc phosphate complex, the method comprising the step of simultaneously reacting a phenylphosphonic acid represented by formula (1) and a phosphate ester represented by formula (2) with a zinc compound (reaction step):

[0029]

[0030] .

[0031] In formula (2), R1 represents alkyl, R2 represents alkylene, and n represents an integer greater than or equal to 1.

[0032] By R 1 The alkyl group can be straight-chain or branched. (By R) 1 The alkyl group represented may have one or more carbon atoms, but may have 15 or fewer, 14 or fewer, 13 or fewer, or 12 or fewer. The phosphate ester represented by formula (2) may be one in which R... 1 A mixture of two or more phosphate esters that are different from each other.

[0033] By R 2 The alkylene group can be straight-chain or branched. (By R) 2 The number of carbon atoms in the alkylene group can be one or more, or two or more, and can be eight or fewer, seven or fewer, six or fewer, five or fewer, four or fewer, or three or fewer. When n is an integer greater than 2, multiple R... 2 They can be the same as each other or different from each other.

[0034] R 2 At least one of them represents an ethylene group. That is, the phosphate ester represented by formula (2) has at least one oxyvinyl group. All R 2 It can be ethylene or R 2 One part may be ethylene while the rest may be alkylene groups other than ethylene.

[0035] The letter n can be an integer greater than or equal to 2, 3, or 4, and less than or equal to 10, 9, 8, 7, 6, 5, or 4. The phosphate ester represented by formula (2) can be a mixture of two or more phosphate esters in which n are different from each other.

[0036] The average molecular weight of the phosphate ester represented by formula (2) can be 100 or more, 200 or more, or 300 or more, and 900 or less, 800 or less, or 700 or less.

[0037] The average molecular weight in this specification refers to the number-average molecular weight measured by gel permeation chromatography (GPC) under the following conditions.

[0038] Measuring instrument: High-speed GPC unit (HLC-8220GPC manufactured by Tosoh Corporation)

[0039] Columns: The following columns manufactured by Tosoh Corporation are used for series connections.

[0040] “TSKgel G5000” (7.8 mm ID × 30 cm) × 1

[0041] “TSKgel G4000” (7.8 mm ID × 30 cm) × 1

[0042] “TSKgel G3000” (7.8 mm ID × 30 cm) × 1

[0043] “TSKgel G2000” (7.8 mm ID × 30 cm) × 1

[0044] Detector: RI (Differential Refractometer)

[0045] Column temperature: 40℃

[0046] Eluent: Tetrahydrofuran (THF)

[0047] Flow rate: 1.0 mL / min

[0048] Injection volume: 100 μL (0.4% by mass tetrahydrofuran solution).

[0049] Standard samples: Calibration curves were created using the following standard polystyrene.

[0050] (Standard polystyrene)

[0051] "TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation

[0052] "TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation

[0053] "TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation

[0054] "TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation

[0055] "TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation

[0056] "TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation

[0057] "TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation

[0058] "TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation

[0059] "TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation

[0060] "TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation

[0061] "TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation

[0062] "TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation

[0063] "TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation

[0064] "TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

[0065] The molar ratio of the amount of phosphate ester represented by formula (2) to the amount of phenylphosphonic acid represented by formula (1) (amount of phosphate ester represented by formula (2) / amount of phenylphosphonic acid represented by formula (1)) can be more than 1 / 99, less than 60 / 40, or between 1 / 99 and 60 / 40. The lower limit of the molar ratio can be 2 / 98, 5 / 95, 10 / 90, 15 / 85, or 20 / 80. The upper limit of the molar ratio can be 55 / 45, 50 / 50, 45 / 55, 40 / 60, 35 / 65, 30 / 70, or 25 / 75.

[0066] The zinc compound that reacts simultaneously with the phenylphosphonic acid represented by formula (1) and the phosphate ester represented by formula (2) can be, for example, zinc halide, zinc oxide, or zinc acetate. The zinc halide can be zinc fluoride, zinc chloride, zinc bromide, or zinc iodide.

[0067] The amount of zinc compound may be more than 0.8 moles, more than 0.9 moles, or more than 0.95 moles, and less than 1.2 moles, less than 1.1 moles, or less than 1.05 moles, relative to the total amount of phenylphosphonic acid represented by formula (1) and phosphate ester represented by formula (2) in 1 mole.

[0068] In the reaction step, for example, the phenylphosphonic acid represented by formula (1) and the phosphate ester represented by formula (2) are simultaneously reacted with the zinc compound by adding an aqueous solution of zinc compound dissolved in water to an aqueous solution of phenylphosphonic acid represented by formula (1) and phosphate ester represented by formula (2). In this process, for example, the above reaction can be carried out by gradually adding an alkaline aqueous solution (e.g., an aqueous solution of sodium hydroxide).

[0069] The white precipitate formed by the reaction was filtered out, washed with water, and then dried to obtain a composition containing zinc phenylphosphonate salt and zinc phosphate complex as a white powder.

[0070] The composition obtained by the above production method contains a zinc phenylphosphonate salt represented by formula (3) and a zinc phosphate complex represented by formula (4). That is, another embodiment of the present invention is a composition containing a zinc phenylphosphonate salt represented by formula (3) and a zinc phosphate complex represented by formula (4):

[0071]

[0072] .

[0073] In equation (4), R1 represents an alkyl group, R2 represents an alkylene group, and n represents an integer greater than or equal to 1. When n is an integer greater than or equal to 2, the plurality of R2s may optionally be the same as or different from each other, and R 2 At least one of them represents ethylene. R 1 R 2 The details of n and the R of the phosphate ester represented by equation (2) 1 R 2 The details are the same as those for n.

[0074] The average molecular weight of the zinc phosphate complex represented by formula (4) can be 150 or more, 250 or more, or 350 or more, and 950 or less, 850 or less, or 750 or less.

[0075] In the composition, the molar ratio of the amount of the zinc phosphate complex represented by formula (4) to the amount of the zinc phenylphosphonate salt represented by formula (3) (amount of zinc phosphate complex represented by formula (4) / amount of zinc phenylphosphonate salt represented by formula (3)) can be more than 1 / 99, less than 60 / 40, or between 1 / 99 and 60 / 40. The lower limit of the molar ratio can be 2 / 98, 5 / 95, 10 / 90, 15 / 85, or 20 / 80. The upper limit of the molar ratio can be 55 / 45, 50 / 50, 45 / 55, 40 / 60, 35 / 65, 30 / 70, or 25 / 75.

[0076] The composition of this embodiment contains, in addition to the zinc phenylphosphonate salt represented by formula (3), a zinc phosphate complex represented by formula (4), and therefore can further shorten the curing time of the moisture-curable hot melt polyurethane resin compared to, for example, a composition containing only the zinc phenylphosphonate salt represented by formula (3). In one embodiment, the composition can improve the initial bond strength of the moisture-curable hot melt polyurethane resin adhesive.

[0077] Therefore, the composition of this embodiment can be suitably used as a crystal nucleating agent, more specifically, as a crystal nucleating agent to promote the crystallization of polyurethane resins. That is, another embodiment of the invention is the use (application) of a composition containing a zinc phenylphosphonate salt represented by formula (3) above and a zinc phosphate complex represented by formula (4) above as a crystal nucleating agent (a crystal nucleating agent to promote the crystallization of polyurethane resins).

[0078] Another embodiment of the present invention is a moisture-curable hot-melt polyurethane resin adhesive containing an isocyanate-terminated polyurethane prepolymer, a zinc phenylphosphonate salt represented by formula (3) above, and a zinc phosphate complex represented by formula (4) above.

[0079] The isocyanate-terminated polyurethane prepolymer can be obtained by reacting a polyol (A) and a polyisocyanate (B) together in the presence of a zinc phenylphosphonate salt represented by formula (3) above and a zinc phosphate complex represented by formula (4) above.

[0080] The polyol (A) may contain aliphatic polyester polyols, two aliphatic polyester polyols (hereinafter aliphatic polyester polyol (a1) and aromatic polyester polyol (a2)), or two aliphatic polyester polyols (hereinafter aliphatic polyester polyol (a1) and aromatic polyester polyol (a2)) and another polyol (a3) ​​other than the aliphatic polyester polyols.

[0081] Aliphatic polyester polyols (a1) are polyester polyols produced by conventional methods using aliphatic polycarboxylic acids and aliphatic polyols as the main components. The production method is not limited to a specific method.

[0082] Preferred examples of aliphatic polycarboxylic acids for the synthesis of aliphatic polyester polyols (a1) include C 4-12 Aliphatic polycarboxylic acids, such as succinic acid, adipic acid, pimelic acid, octanoic acid, azelaic acid, sebacic acid, decanedioic acid, dodecanoic acid, eicosanoic acid, citric acid, itaconic acid, citraconic anhydride, and itaconic anhydride.

[0083] For example, for aliphatic polycarboxylic acids, low alkyl ester derivatives such as methyl esters, acid anhydrides, and corresponding acid derivatives such as acyl halides can be used.

[0084] The aliphatic polyol used to synthesize aliphatic polyester polyol (a1) is an aliphatic polyol having at least two hydroxyl groups in its molecule, preferably C1. 2-12 Aliphatic polyols. (a1) Structurally, they can be linear, branched, or cyclic.

[0085] Examples of aliphatic polyols include straight-chain aliphatic polyols such as ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, diethylene glycol, triethylene glycol, triethylene glycol, and tetraethylene glycol; and branched-chain aliphatic polyols such as neopentyl glycol, 1,3-butanediol, 2,2-diethyl-1,3-propanediol, 2,2-diethylpropanediol, 3-methyl-1,5-pentanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-methyl-1,8-octanediol, 2,4-diethyl-1, 5-Pentanediol, trimethylolethane, trimethylolpropane, and pentaerythritol; and alicyclic polyols, such as cyclopentanediol, cyclohexanediol, and cyclohexanediol. Ethylene glycol, 1,6-hexanediol, and neopentanediol are preferred.

[0086] Alternatively, adducts containing various olefinic oxygens can be used, such as hydrogenated bisphenol A and hydrogenated bisphenol F. Alternatively, polymers obtained by ring-opening polymerization of γ-butyrolactone, ε-caprolactone, etc., using low molecular weight polyols as initiators can be used. These can be used alone or in combination of two or more.

[0087] In combinations of aliphatic polycarboxylic acids and aliphatic polyols, polyol (A) contains C 4-12 Aliphatic polycarboxylic acids and C 2-12 The combination of aliphatic polyols produces aliphatic polyester polyols (a1), which further improves the viscosity stability of hot melt polyurethane resin adhesives during molding and processing, and can produce excellent effects in preventing the reduction of melt viscosity, which is preferred.

[0088] Aromatic polyester polyols (a2) are polyester polyols produced by conventional methods using aromatic polycarboxylic acids and aliphatic polyols or aliphatic polycarboxylic acids and aromatic polyols as the main components. The production method is not limited to a specific method.

[0089] Aromatic polycarboxylic acids are carboxylic acids in which at least two carboxyl groups are bonded to an aromatic ring, and preferably C1646 ... 8-24 Aromatic polycarboxylic acids. Examples include phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, biphenyl phthalic acid, and naphthalenedicarboxylic acid. They can be used alone or in combination of two or more.

[0090] For example, for aromatic polycarboxylic acids, low alkyl ester derivatives such as methyl esters, acid anhydrides, and corresponding acid derivatives such as acyl halides can be used.

[0091] Examples of aliphatic polyols include the same aliphatic polyols that can be used to synthesize aliphatic polyester polyols (a1).

[0092] Aliphatic polyols that can be used to synthesize aromatic polyester polyols (a2) and aliphatic polyester polyols (a1) can be diethylene glycol, triethylene glycol, tetraethylene glycol, 1,4-bis(β-hydroxyethoxy)benzene, etc., in which some carbon atoms are replaced by oxygen atoms or aromatic rings. These aliphatic polyols can also be used alone or in combination of two or more.

[0093] In addition, a mixture of polyester polyols obtained from aromatic polycarboxylic acids and aliphatic polyols can also be used.

[0094] Examples of aliphatic polycarboxylic acids that can be used to synthesize aromatic polyester polyols (a2) include C 4-12 Aliphatic polycarboxylic acids, which are the same as those aliphatic polycarboxylic acids that can be used to synthesize aliphatic polyester polyols (a1).

[0095] Aromatic polyols are not limited to specific aromatic polyols. Examples include aromatic polyols obtained from aliphatic polyols such as ethylene glycol and neopentyl glycol, as well as aromatic polycarboxylic acids such as phthalic acid and terephthalic acid.

[0096] As an aromatic polyol, for example, an adduct obtained by adding olefinic oxygen such as ethylene oxide, propylene oxide and butane oxide to bisphenol A, bisphenol F, etc. can also be used.

[0097] In the synthesis of aliphatic polyester polyols (a1) and aromatic polyester polyols (a2), the equivalence ratio (i.e., [OH / COOH equivalence ratio]) of the hydroxyl groups of the aliphatic and aromatic polyols to the carboxyl groups of the aliphatic and aromatic polycarboxylic acids is preferably in the range of 1.03 to 1.50, more preferably in the range of 1.05 to 1.30. When the [OH / COOH equivalence ratio] is in such a range, a larger amount of hydroxyl-terminated polyol can be generated, and the urethane esterification reaction with polyisocyanate (B) can be carried out more easily, which is preferred.

[0098] The polycondensation conditions in the synthesis of aliphatic polyester polyols (a1) and aromatic polyester polyols (a2) are not limited to specific conditions, as long as no abnormal reactions occur and normal products are obtained. Generally, a certain amount of aliphatic polycarboxylic acids and aliphatic polyols or aromatic polycarboxylic acids and aliphatic polyols can undergo esterification or transesterification reactions for 5 to 50 hours at an internal temperature of 150 to 250°C, with or without a catalyst, followed by polycondensation.

[0099] Polycondensation reactions are preferably carried out in the presence of a catalyst because the reaction proceeds readily. The catalyst is not limited to a specific catalyst. Examples include titanium-based catalysts such as tetrabutoxytitanium and tin-based catalysts such as dibutyltin oxide.

[0100] The catalyst can be added together with aliphatic polyols and aliphatic polycarboxylic acids or aliphatic polyols and aromatic polycarboxylic acids, or added after prepolymerization in the absence of a catalyst.

[0101] In the production of aliphatic polyester polyols (a1) and aromatic polyester polyols (a2), it is desirable to have almost all ends with hydroxyl groups and leave as few carboxyl groups as possible. For this purpose, it is effective and preferred to add a catalyst after prepolymerization.

[0102] The number-average molecular weight (Mn) of the aliphatic polyester polyol (a1) and the aromatic polyester polyol (a2) is preferably in the range of 500 to 6,000, more preferably in the range of 1,000 to 5,000, and particularly preferably in the range of 2,000 to 4,000. When the Mn of (a1) and (a2) are in such ranges, a balance can be obtained according to the properties of the application, such as strength and elongation, which is preferred.

[0103] Examples of other polyols (a3) ​​include polycarbonate polyols, polylactone polyols, and polyether polyols. Examples of polycarbonate polyols include those obtained using linear aliphatic polyols such as 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol. Examples of polylactone polyols include polycaprolactone polyols obtained by ring-opening polymerization of caprolactone monomers. Examples of polyether polyols include polyethylene glycol, polypropylene glycol, and polybutanediol.

[0104] In 100 parts by weight of polyol (A), the content ratio of aliphatic polyester polyol (a1) / aromatic polyester polyol (a2) / other polyol (a3) ​​can be 20 to 60 parts by weight / 10 to 50 parts by weight / 0 to 50 parts by weight, preferably 30 to 50 parts by weight / 20 to 40 parts by weight / 10 to 20 parts by weight. When the content ratio is within such a range, the melt viscosity of polyol (A) can be adjusted to an appropriate range, and a moisture-curable hot melt polyurethane resin adhesive exhibiting excellent processability and miscibility, as well as further excellent curing properties, can be obtained.

[0105] Examples of polyisocyanates (B) include commonly known aliphatic, aromatic, and alicyclic polyisocyanates. Examples include: aromatic diisocyanates such as diphenylmethane diisocyanate (MDI; 4,4', 2,4', 2,2' types, mixtures thereof, and crude MDI), carbodiimide-modified MDI (modified MDI), polymethylene polyphenyl polyisocyanate, carbodiimide-modified diphenylmethane polyisocyanate, xylene diisocyanate, toluene diisocyanate (TDI; 2,4', 2,6' types, mixtures thereof), xylene diisocyanate (XDI), 1,5', and so on. - Naphthalene diisocyanate (NDI), tetramethylxylene diisocyanate, and phenylene diisocyanate; aliphatic diisocyanates, such as hexamethylene diisocyanate (HDI), dimer acid diisocyanate, norbornene diisocyanate, lysine diisocyanate, and tetramethylxylene diisocyanate; and alicyclic diisocyanates, such as isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated xylene diisocyanate (hydrogenated XDI), cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, and isophorone diisocyanate. MDI and XDI are preferred because they react rapidly with polyol (A) and water (aqueous solution), exhibiting excellent processability. They can be used alone or in combination of two or more.

[0106] When synthesizing isocyanate-terminated polyurethane prepolymers (hereinafter referred to as "prepolymers"), the ratio between the polyol (A) and the polyisocyanate (B) used can be within a range that does not adversely affect reaction behavior, product quality, etc. Typically, the equivalent ratio of the isocyanate groups in the polyisocyanate (B) to the hydroxyl groups in the polyol (A) (hereinafter referred to as the [NCO / OH equivalent ratio]) is preferably in the range of 1.2 to 4.0, more preferably in the range of 1.5 to 3.0. When the [NCO / OH equivalent ratio] is within such a range, the melt viscosity of the target wet-curable hot-melt polyurethane resin composition is within an appropriate range, and it can exhibit properties such as excellent processability, film properties, and further excellent curing properties.

[0107] The reaction conditions can be set as long as they do not adversely affect the reaction behavior or product quality, and are not limited to specific conditions. Generally, they are preferably set at a reaction temperature of 80 to 130°C for 1 to 10 hours.

[0108] For the reaction method, for example, a known reaction method can be selected, such as a batch reaction, a semi-continuous reaction, or a continuous reaction.

[0109] The reaction can be carried out in a solvent or without a solvent. However, when the reaction is carried out in a solvent, it is preferable to remove the solvent during or after the reaction to ultimately eliminate the solvent. The method of solvent removal is not limited to a specific method.

[0110] Based on the total amount of the wet-curable hot-melt polyurethane resin adhesive, the total amount of zinc phenylphosphonate salt represented by formula (3) and zinc phosphate complex represented by formula (4) is 0.1% by mass or more, 10% by mass or less, or 0.1% to 10% by mass. Based on the total amount of the wet-curable hot-melt polyurethane resin adhesive, the lower limit of the total amount can be 0.3% by mass, 0.5% by mass or 1% by mass. Based on the total amount of the wet-curable hot-melt polyurethane resin adhesive, the upper limit of the total amount can be 7% by mass, 5% by mass or 3% by mass.

[0111] In a moisture-curable hot-melt polyurethane resin adhesive, the molar ratio of the amount of zinc phosphate complex represented by formula (4) to the amount of zinc phenylphosphonate salt represented by formula (3) (amount of zinc phosphate complex represented by formula (4) / amount of zinc phenylphosphonate salt represented by formula (3)) can be more than 1 / 99, less than 60 / 40, or between 1 / 99 and 60 / 40. The lower limit of the molar ratio can be 2 / 98, 5 / 95, 10 / 90, 15 / 85, or 20 / 80. The upper limit of the molar ratio can be 55 / 45, 50 / 50, 45 / 55, 40 / 60, 35 / 65, 30 / 70, or 25 / 75.

[0112] The moisture-curable hot-melt polyurethane resin adhesive of this embodiment may also contain other resins, such as previously known thermoplastic and thermosetting resins, and may also contain other additives. Examples of other additives include foam stabilizers, antioxidants, defoamers, UV absorbers, abrasives, fillers, pigments, dyes, colorants, thickeners, surfactants, flame retardants, plasticizers, lubricants, antistatic agents, heat stabilizers, adhesion promoters, curing catalysts, stabilizers, optical brighteners, silane coupling agents, and waxes.

[0113] The present invention will be further described in detail below based on embodiments. The present invention is not limited to these embodiments.

[0114] [Example 1]

[0115] (Production of compositions containing zinc phenylphosphonate salt and zinc phosphate complex)

[0116] To prepare an aqueous solution, 12.3 parts by mass (78.0 mmol) of phenylphosphonic acid represented by formula (1), 2.0 parts by mass (4.1 mmol) of phosphate ester represented by formula (2A) (where n represents an integer greater than 1), and 600 parts by mass of water were added to a 3-liter four-necked flask.

[0117]

[0118] To the flask, an aqueous solution prepared from 11.2 parts by mass (82.2 mmol) of zinc chloride and 260 parts by mass of water was added and mixed together. Under stirring, 1,608 parts by mass of 0.1 M sodium hydroxide aqueous solution was added to the solution over 6 hours to allow it to react. The white precipitate was filtered off, washed with water, and then dried under reduced pressure at 80°C for at least 2 hours to obtain composition 1 as a white powder, containing zinc phenylphosphonate salt represented by formula (3) and a zinc phosphate complex with an average molecular weight of 543 represented by formula (4A) (where n represents an integer greater than or equal to 1).

[0119]

[0120] (Production of moisture-curable hot-melt polyurethane resin adhesives)

[0121] In a 1-liter four-necked flask, 30 parts by weight of polypropylene glycol (Mn = 1,000), 40 parts by weight of aliphatic polyester polyol (Mn = 4,500), and 30 parts by weight of aromatic polyester polyol (Mn = 5,000) were mixed and melted to prepare polyol (A). The aliphatic polyester polyol was obtained by reacting 1,6-hexanediol (HD) and adipic acid (AA) with each other in a mass ratio of HD / AA = 46 / 54. The aromatic polyester polyol was obtained by reacting 1,6-hexanediol (HD), neopentyl glycol (NPG), ethylene glycol (EG), isophthalic acid (iPA), and terephthalic acid (tPA) with each other in a mass ratio of HD / NPG / EG / iPA / tPA = 7 / 14 / 18 / 40 / 21.

[0122] Next, 1.2 parts by weight (1.0 parts by weight based on the total amount of the adhesive) of composition 1 was added to (A) as a crystallizing nucleating agent, and the mixture was heated to 110°C and dehydrated under reduced pressure until the moisture content reached 0.05 by weight.

[0123] Subsequently, it was cooled to 70°C, and 19 parts by weight of 4,4-diphenylmethane diisocyanate were added. The mixture was then reacted at 90°C for 3 hours until the NCO content (%) became constant, in order to obtain a moisture-curable hot melt polyurethane resin adhesive.

[0124] [Example 2]

[0125] Except for using 11.7 parts by weight (73.9 mmol) of phenylphosphonic acid and 3.9 parts by weight (8.2 mmol) of the phosphate ester represented by formula (2A), the same operation as in Example 1 was performed to obtain composition 2 as a white powder. Except for using composition 2, the same operation as in Example 1 was performed to obtain a moisture-curable hot-melt polyurethane resin adhesive.

[0126] [Example 3]

[0127] Except for using 10.0 parts by weight (63.3 mmol) of phenylphosphonic acid and 9.0 parts by weight (18.8 mmol) of the phosphate ester represented by formula (2A), the same operation as in Example 1 was performed to obtain composition 3 as a white powder. Except for using composition 3, the same operation as in Example 1 was performed to obtain a moisture-curable hot-melt polyurethane resin adhesive.

[0128] [Example 4]

[0129] Except for using 9.1 parts by weight (57.5 mmol) of phenylphosphonic acid and 11.8 parts by weight (24.6 mmol) of the phosphate ester represented by formula (2A), the same procedure as in Example 1 was performed to obtain composition 4 as a white powder. Except for using composition 4, the same procedure as in Example 1 was performed to obtain a moisture-curable hot-melt polyurethane resin adhesive.

[0130] [Example 5]

[0131] Except for using 6.5 parts by weight (41.1 mmol) of phenylphosphonic acid and 19.7 parts by weight (41.1 mmol) of the phosphate ester represented by formula (2A), the same operation as in Example 1 was performed to obtain composition 5 as a white powder. Except for using composition 5, the same operation as in Example 1 was performed to obtain a moisture-curable hot-melt polyurethane resin adhesive.

[0132] [Example 6]

[0133] Add 12.6 parts by weight (80.0 mmol) of phenylphosphonic acid and 1.4 parts by weight (2.1 mmol) of the solution from formula (2B) to a 3-liter four-necked flask. (In the formula, R1 represents C) 12 H 25 Or C 14 H 29 An aqueous solution is prepared by combining an alkyl group (represented by a phosphate ester with an average molecular weight of 671) with 600 parts by mass of water.

[0134]

[0135] To the flask, an aqueous solution prepared from 11.2 parts by mass (82.2 mmol) of zinc chloride and 260 parts by mass of water was added and mixed together. Under stirring, 1,606 parts by mass of 0.1 M sodium hydroxide aqueous solution was added to the solution over 6 hours to allow it to react. The white precipitate was filtered off, washed with water, and then dried under reduced pressure at 80 °C for at least 2 hours to obtain composition 6 as a white powder, which contains zinc phenylphosphonate salt represented by formula (3) and [a compound from formula (4B)] (where R1 represents C). 12 H 25 Or C 14 H 29 (The alkyl group represents a zinc phosphate complex with an average molecular weight of 753.)

[0136]

[0137] Except for using composition 6, the same operation as in Example 1 was performed to obtain a moisture-curable hot melt polyurethane resin adhesive.

[0138] [Example 7]

[0139] Except for using 12.3 parts by weight (78.0 mmol) of phenylphosphonic acid and 2.7 parts by weight (4.1 mmol) of the phosphate ester represented by formula (2B), the same operation as in Example 6 was performed to obtain composition 7 as a white powder. Except for using composition 7, the same operation as in Example 1 was performed to obtain a moisture-curable hot-melt polyurethane resin adhesive.

[0140] [Example 8]

[0141] Except for using 11.7 parts by weight (73.9 mmol) of phenylphosphonic acid and 5.1 parts by weight (8.2 mmol) of the phosphate ester represented by formula (2B), the same operation as in Example 6 was performed to obtain composition 8 as a white powder. Except for using composition 8, the same operation as in Example 1 was performed to obtain a moisture-curable hot-melt polyurethane resin adhesive.

[0142] [Example 9]

[0143] Except for using 10.0 parts by weight (63.3 mmol) of phenylphosphonic acid and 12.5 parts by weight (18.7 mmol) of the phosphate ester represented by formula (2B), the same operation as in Example 6 was performed to obtain composition 9 as a white powder. Except for using composition 9, the same operation as in Example 1 was performed to obtain a moisture-curable hot-melt polyurethane resin adhesive.

[0144] [Comparative Example 1]

[0145] Except for the absence of composition 1, the same procedure as in Example 1 was performed to obtain a moisture-curable hot melt polyurethane resin adhesive.

[0146] [Comparative Example 2]

[0147] Except for replacing composition 1 with zinc phenylphosphonate obtained through the following procedure, the same operation as in Example 1 was performed to obtain a moisture-curable hot melt polyurethane resin adhesive.

[0148] To prepare an aqueous solution, 10.0 parts by weight (63.3 mmol) of phenylphosphonic acid and 400 parts by weight of water were added to a 3-liter four-necked flask. Then, an aqueous solution prepared from 8.6 parts by weight (63.3 mmol) of zinc chloride and 200 parts by weight of water was added to the same flask and mixed together. Under stirring, 1,244 parts by weight of 0.1 M sodium hydroxide aqueous solution was added to this solution over 6 hours to allow the reaction to proceed. The resulting white precipitate was filtered off, washed with water, and then dried under reduced pressure at 80°C for at least 2 hours to obtain zinc phenylphosphonate as a white powder.

[0149] [Assessment of curing time (open time)]

[0150] Each of the wet-curable hot-melt polyurethane resin adhesives obtained in the examples and comparative examples was prepared into a molten state at 120°C and coated onto a polypropylene sheet as a substrate to a thickness of 50 μm. Next, kraft paper, serving as a surface member, was placed on the adhesive layer coated as described above and immediately placed in a constant-temperature oven at 23°C. Based on the time point of placement in the constant-temperature oven, the time (in seconds) until the kraft paper no longer adhered to the adhesive layer was measured and determined as the curing time at 23°C (open time at 23°C). The results are listed in Table 1.

[0151] [Initial Bond Strength Assessment]

[0152] Each of the wet-curable hot-melt polyurethane resin adhesives obtained in the examples and comparative examples was prepared into a molten state at 120°C, and 1 ml of adhesive was applied to a single-sided area of ​​4 cm². 2 The wood block substrate was then glued to another wood block substrate without adhesive and placed in a constant temperature oven at 23°C for 3 minutes. The tensile strength (mPa) was measured and determined as the initial bond strength.

[0153] [Table 1]

[0154]

Claims

1. A method for producing a composition comprising a zinc phenylphosphonate salt represented by formula (3) and a zinc phosphate complex represented by formula (4), The method includes the step of simultaneously reacting a phenylphosphonic acid represented by formula (1) and a phosphate ester represented by formula (2) with a zinc compound: In equations (4) and (2), R 1 C represents 1-15 Alkyl, R 2 C represents 1-8 Alkylene, and n represents an integer from 1 to 10. When n is an integer greater than 2, multiple R... 2 They may be identical or different from each other, and R 2 At least one of them represents ethylene.

2. The method for producing the composition according to claim 1, wherein the molar ratio of the amount of phosphate ester represented by formula (2) to the amount of phenylphosphonic acid represented by formula (1) is from 1 / 99 to 60 / 40.

3. A composition comprising a zinc phenylphosphonate salt represented by formula (3) and a zinc phosphate complex represented by formula (4): In equation (4), R 1 C represents 1-15 Alkyl, R 2 C represents 1-8 Alkylene, and n represents an integer from 1 to 10. When n is an integer greater than 2, multiple R... 2 They may be identical or different from each other, and R 2 At least one of them represents ethylene.

4. The composition according to claim 3, wherein the molar ratio of the amount of the phosphate ester represented by formula (4) to the amount of the phenylphosphonic acid represented by formula (3) is from 1 / 99 to 60 / 40.

5. Use of the composition according to claim 3 or 4 as a crystallizing nucleating agent.

6. A moisture-curable hot-melt polyurethane resin adhesive, said moisture-curable hot-melt polyurethane resin adhesive comprising an isocyanate-terminated polyurethane prepolymer, a zinc phenylphosphonate salt represented by formula (3), and a zinc phosphate complex represented by formula (4): In equation (4), R 1 C represents 1-15 Alkyl, R 2 C represents 1-8 Alkylene, and n represents an integer from 1 to 10. When n is an integer greater than 2, multiple R... 2 They may be identical or different from each other, and R 2 At least one of them represents ethylene.

7. The moisture-curable hot-melt polyurethane resin adhesive according to claim 6, wherein the molar ratio of the amount of phosphate ester represented by formula (4) to the amount of phenylphosphonic acid represented by formula (3) is 1 / 99 to 60 / 40.

8. The moisture-curable hot melt polyurethane resin adhesive according to claim 6 or 7, wherein the total amount of the zinc phenylphosphonate salt represented by formula (3) and the zinc phosphate complex represented by formula (4) is 0.1 to 10 by mass based on the total amount of the moisture-curable hot melt polyurethane resin adhesive.

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