JP7451072B2 - Moisture-curing hot melt adhesives and laminates - Google Patents

Description

The present invention relates to a moisture-curable hot melt adhesive and a laminate obtained using the same.

Conventionally, organic solvent-based resin compositions have been used in a wide variety of fields, for example, as adhesives and pressure-sensitive adhesives. However, since the organic solvent-based resin composition contains a large amount of organic solvent, it is harmful to the human body, poses a risk of ignition, pollutes the environment such as water quality and air, reduces productivity due to drying, and causes loss of solvent recovery. There were various problems such as energy burden for solvent recovery.

Therefore, various solvent-free resin compositions have been studied as adhesives to replace organic solvent-based resin compositions. Among them, moisture-curing urethane adhesives have excellent adhesive properties and are easy to adjust the adhesion time, so they are attracting attention as suitable for molding processes such as bonding and sealing work that require continuous production. are collecting. Such moisture-curable urethane adhesives include, for example, polyester polyols obtained by reacting polyols in which alkylene oxide is added to bisphenol A, aliphatic polycarboxylic acids, and aromatic polycarboxylic acids, crystalline polyester polyols, and 2, A moisture-curing adhesive containing a urethane prepolymer obtained by reacting a polyol containing polyoxyethylene glycol having a number average molecular weight of 000 to 25,000 with a polyisocyanate has been proposed (see Patent Document 1). )

Patent No. 4240158

However, with conventionally known moisture-curing adhesives, the higher the moisture permeability, the more likely the adhesive strength will decrease.

An object of the present invention is to provide a moisture-curing adhesive that can improve adhesive strength while maintaining moisture permeability.

The present invention is a moisture-curable adhesive containing a urethane prepolymer having an isocyanate group, wherein the urethane prepolymer having an isocyanate group is a reaction product of a polyol (A) and a polyisocyanate (B), The polyol (A) contains a polycarbonate polyol (a1) having a unit derived from a hydroxy compound (d1) represented by the general formula (1), and the hydroxy compound (d1) contains diethylene glycol and triethylene glycol. or triethylene glycol, and relates to a moisture-curable adhesive containing 20% by mass or more of triethylene glycol .

［一般式（１）中、ｎは、２以上７以下の整数を表す。］

[In general formula (1), n represents an integer of 2 or more and 7 or less. ]

According to the moisture-curing adhesive of the present invention, it is possible to provide a cured product with improved adhesive strength while maintaining moisture permeability.

The moisture-curable adhesive of the present invention contains a urethane prepolymer having isocyanate groups. The isocyanate group is preferably present at the end of the urethane prepolymer having the isocyanate group. The urethane prepolymer having isocyanate groups is a reaction product of polyol (A) and polyisocyanate (B). The polyol (A) is a compound having two or more hydroxyl groups, and includes a polycarbonate polyol (a1) having a unit derived from the hydroxy compound (D).

The content of the polycarbonate polyol (a1) in the polyol (A) is preferably 10% by mass or more, more preferably 15% by mass or more, even more preferably 20% by mass or more, and 100% by mass or less, preferably is 90% by mass or less.
The hydroxy compound (D) is a compound having two or more hydroxy groups. As the hydroxy compound (D), one type or two or more types can be used, for example, ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene. Diols such as glycol, polyethylene glycol and polypropylene glycol; polyols such as trimethylolmethane, trimethylolpropane, ditrimethylolpropane, pentaerythritol and dipentaerythritol.

In particular, the hydroxy compound (D) includes a hydroxy compound (d1) represented by general formula (1). The polycarbonate polyol (a1) is obtained by containing a unit (-O-(-(CH ₂ ) ₂ O-) _n -) derived from the hydroxy compound (d1) represented by the general formula (1). Both moisture permeability and heat resistance of the cured product can be achieved.

［一般式（１）中、ｎは、２以上７以下の整数を表す。］

[In general formula (1), n represents an integer of 2 or more and 7 or less. ]

As the hydroxy compound (d1), one type or two or more types can be used, and examples thereof include diethylene glycol, triethylene glycol, polyethylene glycol (preferably molecular weight 160 to 360, more preferably molecular weight 190 to 330). It will be done. Among them, diethylene glycol and triethylene glycol are preferred from the viewpoint of even better moisture permeability and heat resistance.

The content of the hydroxy compound (d1) is preferably 40% by mass or more, more preferably 60% by mass or more, and preferably 100% by mass or less, more preferably 99% by mass based on 100% by mass of the hydroxy compound (D). % or less. When the content of the hydroxy compound (d1) is within the above range, the adhesive strength can be improved while maintaining the moisture permeability of the resulting cured product.

Among these, the hydroxy compound (d1) preferably contains triethylene glycol and/or polyethylene glycol, and in this case, the content of triethylene glycol and/or polyethylene glycol is preferably in the range of 100% by mass of the hydroxy compound (d1). is 10% by mass or more, more preferably 20% by mass or more, and preferably 100% by mass or less, more preferably 99% by mass or less. When the content of triethylene glycol and/or polyethylene glycol is within the above range, adhesive strength can be highly improved while maintaining moisture permeability of the resulting cured product.

When the hydroxy compound (D) contains a hydroxy compound other than the hydroxy compound (d1), the other hydroxy compound may include butanediol, trimethylol, etc. from the viewpoint of improving adhesive strength while maintaining moisture permeability. Propane is preferred.

The polycarbonate polyol (a1) can be produced by reacting the hydroxy compound (D) and the carbonate compound (E) in the presence of an optional polycarbonation or transesterification catalyst.
During the reaction, a titanium compound such as a titanium alcoholate such as tetramethyl titanate, tetraisopropyl titanate, or tetrabutyl titanate, or a titanium phenolate such as tetraphenyl titanate may be coexisting as a polycarbonation or transesterification catalyst. As the polycarbonation or ester catalyst, a metal catalyst, an acid catalyst, etc. may be used.
The amount of the polycarbonation or transesterification catalyst is preferably 0.001 parts by mass or more, more preferably 0.05 parts by mass or more, based on a total of 100 parts by mass of the hydroxy compound (D) and carbonate compound (E). The amount is preferably 1 part by mass or less, more preferably 0.5 part by mass or less, even more preferably 0.3 part by mass or less.
Moreover, the polycarbonate polyol (a1) can be obtained using a known production method, such as one obtained by reacting the hydroxy compound (D) with phosgene.

As the carbonate compound (E), one type or two or more types can be used, and examples thereof include aliphatic carbonates and aromatic ring-containing carbonates. Examples of aliphatic carbonates include saturated aliphatic carbonates such as dimethyl carbonate, diethyl carbonate, ethylmethyl carbonate, di-n-butyl carbonate, diisobutyl carbonate, ethyl-n-butyl carbonate, and ethyl isobutyl carbonate; ethylene carbonate, trimethylene carbonate, Tetramethylene carbonate, 1,2-propylene carbonate, 1,2-butylene carbonate, 1,3-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 1,3-pentylene carbonate, 1, Examples include unsaturated aliphatic carbonates such as 4-pentylene carbonate, 1,5-pentylene carbonate, 2,3-pentylene carbonate and 2,4-pentylene carbonate. Examples of the aromatic ring-containing carbonate include diphenyl carbonate and dibenzyl carbonate. Among these, saturated aliphatic carbonates such as dimethyl carbonate, ethylmethyl carbonate, and diethyl carbonate; aromatic carbonates such as diphenyl carbonate are preferable because they allow a urethane resin molded product with excellent chemical resistance to be obtained.

The number average molecular weight of the polycarbonate polyol (a1) is preferably 500 or more, more preferably 1,000 or more, and preferably 8,000 or less, more preferably 6,000 or less.

The hydroxyl value of the polycarbonate polyol (a1) is preferably 10 mgKOH/g or more, more preferably 20 mgKOH/g or more, and preferably 210 mgKOH/g or less, more preferably 120 mgKOH/g or less. The hydroxyl value is defined as the number of mg of potassium hydroxide corresponding to hydroxyl groups in 1 g of polycarbonate polyol, and represents a value measured in accordance with JIS K1557-1:2007.

The polyol (A) is a compound having two or more hydroxyl groups, and may contain a polyalkylene polyol (a2) having an oxyethylene unit to the extent that the effects of the present invention are not impaired. The polyalkylene polyol (a2) containing oxyethylene units (-O-CH ₂ CH ₂ -) may be a homopolymer consisting only of oxyethylene units, and the polyalkylene polyol (a2) containing oxyethylene units and carbon atoms of 3 or more (preferably may be a copolymer having 3 to 4) oxyethylene units.

The weight average molecular weight of the polyalkylene polyol (a2) is preferably 1,000 or more, more preferably 2,000 or more, preferably 20,000 or less, more preferably 10,000 or less, even more preferably 5, 000 or less.

The content of the polyalkylene polyol (a2) in the polyol (A) is preferably 2% by mass or more, more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 45% by mass or less. It is.

The polyol (A) may contain a polyol (a3) other than the polycarbonate polyol (a1) and the polyalkylene polyol (a2). Examples of the other polyol (a3) include polycarbonate polyols other than the polycarbonate polyol (a1), polyether polyols other than the polyalkylene polyol (a2), polyester polyols, and the like.

Examples of polycarbonate polyols other than the polycarbonate polyol (a1) include polycarbonate polyol compounds that have units derived from the other hydroxy compound and do not have units derived from the hydroxy compound (d1).

As the polyether polyol other than the polyalkylene polyol (a2), one type or two or more types can be used. For example, one type or two or more types of compounds having two or more active hydrogen atoms are used as an initiator, Examples include compounds obtained by addition polymerization of alkylene oxide. Examples of the compound having two or more active hydrogen atoms include propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, glycerin, and dipropylene glycol. Examples include glycerin, trimethylolethane, trimethylolpropane, water, hexanetriol, and the like. Furthermore, examples of the alkylene oxide include propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, and tetrahydrofuran.

As the polyester polyol, one type or two or more types can be used, and for example, a reaction product of a polycarboxylic acid and a polyol, a polylactone polyol, etc. can be used.

As the polycarboxylic acid, one type or two or more types can be used. For example, aromatic polycarboxylic acids such as orthophthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, biphenyldicarboxylic acid, naphthalene dicarboxylic acid, etc. Carboxylic acid; ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1, Straight chain aliphatic polyols such as 9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, diethylene glycol, triethylene glycol, triethylene glycol, tetraethylene glycol; 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- Branched aliphatic polyols such as methyl-1,8-octanediol, 2,4-diethyl-1,5-pentanediol, trimethylolethane, trimethylolpropane, pentaerythritol; cyclopentanediol, cyclohexanediol, cyclohexanedimethanol alicyclic polyols such as hydrogenated bisphenol A and hydrogenated bisphenol F; alkylene oxide adducts of hydrogenated bisphenol A and hydrogenated bisphenol F; ring-opening polymerization of lactone compounds such as γ-butyrolactone and ε-butyrolactone to the linear aliphatic or alicyclic polyols; Examples include polymers. Among these, aromatic polycarboxylic acids such as orthophthalic acid and terephthalic acid; aliphatic polycarboxylic acids such as adipic acid, sebacic acid, decanedioic acid, and dodecanedioic acid are more preferred.
As the polycarboxylic acid, for example, lower alkyl ester derivatives such as methyl ester, acid derivatives such as acid anhydrides, and acid halides may be used.

The polyols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, Straight chain aliphatic polyols such as 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, diethylene glycol, triethylene glycol, triethylene glycol, tetraethylene glycol; 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, Examples include branched aliphatic polyols such as 2-methyl-1,8-octanediol, 2,4-diethyl-1,5-pentanediol, trimethylolethane, trimethylolpropane, and pentaerythritol. The alicyclic polyols include alicyclic polyols such as cyclopentanediol, cyclohexanediol, and cyclohexanedimethanol; alkylene oxide adducts of hydrogenated bisphenol A and hydrogenated bisphenol F; ethylene glycol to the aromatic polycarboxylic acid; Compounds with alkylene glycol added, such as propylene glycol, tetramethylene glycol, and neopentyl glycol; Aromatic polyols, such as bisphenol A, bisphenol F, and benzenediol; Aromatic compounds, such as 1,4-bis(β-hydroxyethoxy)benzene Examples include compounds in which alkylene glycol is added to polyol. Among these, aliphatic polyols such as ethylene glycol, 1,6-hexanediol, and neopentyl glycol are preferred.

The equivalent ratio between the hydroxyl group of the polyol and the carboxyl group of the polycarboxylic acid (that is, [OH/COOH equivalent ratio]) is preferably 1.02 or more, more preferably 1.05 or more on a molar basis. , preferably 1.50 or less, more preferably 1.30 or less.If the [OH/COOH equivalent ratio] is within the above range, a larger amount of hydroxyl group-terminated polyol can be produced.

The number average molecular weight of the polyester polyol is preferably 500 or more, more preferably 1,000 or more, still more preferably 2,000 or more, and preferably 10, 000 or less, more preferably 8,000 or less, still more preferably 6,000 or less.

Examples of the polycaprolactone polyol include polylactone polyols obtained by ring-opening polymerization of lactone monomers such as α-acetolactone, β-propiolactone, γ-butyrolactone, ε-caprolactone, and δ-valerolactone. .

The polyisocyanate (B) is a compound having two or more isocyanate groups, and one type or two or more types can be used. Examples include aliphatic polyisocyanate, alicyclic polyisocyanate, and aromatic polyisocyanate. It will be done.

Examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI), dimer acid diisocyanate, norbornene diisocyanate, lysine diisocyanate, and tetramethylxylylene diisocyanate.

Examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), hydrogenated xylylene diisocyanate (hydrogenated XDI), cyclohexane diisocyanate, dicyclohexylmethane diisocyanate, isophorone diisocyanate, and the like. It will be done.

As the aromatic polyisocyanate, one type or two or more types can be used, for example, phenylene diisocyanate, tolylene diisocyanate (TDI; 2,4 body or 2,6 body, or a mixture thereof), diphenylmethane diisocyanate ( MDI; its 4,4' form, 2,4' form or 2,2' form, or a mixture thereof, crude MDI), 1,5-naphthalene diisocyanate (NDI), xylylene diisocyanate (XDI), tetramethylxylene Aromatic diisocyanates such as diisocyanate; Aromatic polyisocyanates having three or more isocyanate groups such as polyphenylene polymethylene polyisocyanate, formalin condensate of methylene diphenyl diisocyanate, and carbodiimide modified product of diphenylmethane diisocyanate.

The equivalent ratio of the isocyanate groups of the polyisocyanate (B) to the hydroxyl groups of the polyol (A) ([NCO/OH equivalent ratio]) is determined based on the melting temperature and workability of the moisture-curing adhesive, the physical properties of the film, and the speed. From the viewpoint of curability etc., on a molar basis, it is preferably 1.1 or more, more preferably 1.2 or more, and preferably 4 or less, more preferably 3 or less.

The isocyanate group content of the urethane prepolymer having isocyanate groups is preferably 1% by mass or more, more preferably 1.5% by mass or more, and preferably 8% by mass or less, more preferably 7% by mass or less, and Preferably it is 6% by mass or less.

By reacting the polyol (A) with the polyisocyanate (B), a urethane prepolymer having an isocyanate group, which is included in the moisture-curable adhesive of the present invention, can be produced. The reaction temperature is preferably 80°C or more and 130°C or less, and the reaction time is preferably 1 hour or more and 10 hours or less. The reaction atmosphere may be any condition that does not contain moisture, such as a dry air atmosphere or a closed atmosphere. During the reaction, an inert gas atmosphere such as nitrogen or argon is preferable, and a solvent may be coexisting. In this case, it is preferable to remove the solvent during or after the reaction.

Further, a catalyst may be present in the reaction. Examples of the catalyst include transition metal compound catalysts such as titanium tetrabutoxide, dibutyltin oxide, dibutyltin dilaurate, tin 2-ethylcaproate, zinc naphthenate, cobalt naphthenate, zinc 2-ethylcaproate, and molybdenum glycolate. , iron chloride, zinc chloride, etc., and amine catalysts such as triethylamine, tributylamine, triethylenediamine, benzyldibutylamine, etc.

In addition to the above-mentioned urethane prepolymer having an isocyanate group, the moisture-curable adhesive of the present invention includes a crystal nucleating agent, a foam stabilizer, an antioxidant, a defoaming agent, an ultraviolet absorber, an abrasive grain, a filler, a pigment, and a dye. , colorants, thickeners, surfactants, flame retardants, plasticizers, lubricants, antistatic agents, heat stabilizers, tackifiers, curing catalysts, stabilizers, optical brighteners, silane coupling agents, waxes, etc. It may also contain blending resins such as additives and thermoplastic resins and thermosetting resins.

The melt viscosity of the moisture-curable adhesive of the present invention at a measurement temperature of 120°C is preferably 500 mPa·s or more, more preferably 1,000 mPa·s or more, and preferably 50,000 mPa·s or less, more preferably It is 30,000 mPa·s or less. Having a melt viscosity within the above range is effective in improving workability during processing and preventing appearance defects such as air pockets.

The processing temperature of the moisture-curable adhesive of the present invention is at least the melting point of the resin composition, preferably 80°C or more and 130°C or less, more preferably 100°C or more and 120°C or less. When the processing temperature is within the above range, operational defects are less likely to occur, operational efficiency is good, and deterioration, decomposition, gelation, etc. of the resin composition can be suppressed.

A laminate using the moisture-curing adhesive of the present invention is also included within the technical scope of the present invention.

The thickness of the cured layer of the moisture-curable adhesive of the present invention is preferably 10 μm or more and 5000 μm or less.

A method for obtaining an adhesive layer using the moisture-curable adhesive of the present invention includes, for example, a method in which a base material and a sheet or film are bonded together and then moisture-cured.

As a method of bonding a substrate and a sheet or film, etc. using the moisture-curing adhesive of the present invention, for example, the moisture-curing adhesive is melted by heating in the range of 60 to 150°C, and then rolled. Coating onto the base material using a coater, spray coater, T-die coater, knife coater, etc., and pasting the sheet, etc. on the coated surface, or coating on the sheet, etc. using the roll coater, etc. However, a method can be used in which the base material is laminated to the coated surface and the base material is pressed appropriately according to the shape of the base material by a method such as a roll press, a flat press, or a belt press. After the pressure bonding, it may be cured for 1 to 7 days, if necessary.

The moisture-curing adhesive of the present invention is applicable not only to the building materials and textile fields, but also to the electrical and electronic parts manufacturing industry, the automobile manufacturing industry, the semiconductor parts manufacturing industry, the shoe manufacturing industry, the lumber processing industry, the building materials industry, the bookbinding industry, and the metal industry. It can be used in a wide range of fields such as the resin processing industry.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

(Synthesis Example 1: Synthesis of polycarbonate polyol (1))
A four-necked flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with 50 parts by mass of diethylene glycol, 50 parts by mass of triethylene glycol, and 152 parts by mass of diphenyl carbonate, and tetraisopropyl titanate was added as a polycarbonate catalyst. 0.01% by mass was added, reacted at 200°C for 5 hours, and then reacted under reduced pressure conditions for 10 hours to obtain polycarbonate polyol (1). The hydroxyl group value of this polycarbonate polyol (1) was 55 mgKOH/g.

(Synthesis Example 2: Synthesis of polycarbonate polyol (2))
In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, 70 parts by mass of diethylene glycol, 30 parts by mass of polyethylene glycol ("PEG #200" manufactured by NOF Corporation), and 153 parts by mass of diphenyl carbonate. was charged, 0.01% by mass of tetraisopropyl titanate was added as a polycarbonation catalyst, and the mixture was reacted at 200° C. for 5 hours, and then under reduced pressure for 10 hours to obtain polycarbonate polyol (2). The hydroxyl group value of this polycarbonate polyol (2) was 57 mgKOH/g.

(Synthesis Example 3: Synthesis of polycarbonate polyol (3))
A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with 50 parts by mass of triethylene glycol, 50 parts by mass of 1,4-butanediol, and 173 parts by mass of diphenyl carbonate, and a polycarbonate catalyst was prepared. 0.01% by mass of tetraisopropyl titanate was added thereto, and the mixture was reacted at 200° C. for 5 hours, and then under reduced pressure for 10 hours to obtain polycarbonate polyol (3). The hydroxyl value of this polycarbonate polyol (3) was 37 mgKOH/g.

(Synthesis Example 4: Synthesis of polycarbonate polyol (4))
A four-neck flask equipped with a thermometer, a stirrer, an inert gas inlet, and a reflux condenser was charged with 20 parts by mass of triethylene glycol, 80 parts by mass of 1,4-butanediol, and 127 parts by mass of diethyl carbonate, and a polycarbonate catalyst was added. 0.01% by mass of tetraisopropyl titanate was added thereto, and the mixture was reacted at 120°C for 10 hours, then at 190°C for 2 hours, and then for 10 hours under reduced pressure to obtain polycarbonate polyol (4). The hydroxyl value of this polycarbonate polyol (4) was 38 mgKOH/g.

[Synthesis Example 5] Synthesis of moisture-curable polyurethane adhesive (X-1) 99 parts by mass of polycarbonate polyol (1) and PET-1 (manufactured by Mitsui Chemicals Polyurethane: 1 part by mass of T-700) was added and dehydrated under reduced pressure until the water content was 0.05% by mass or less. Next, after cooling the container internal temperature to 70°C, 28 parts by mass of 4,4'-diphenylmethane diisocyanate was added, the temperature was raised to 100°C, and the reaction was carried out for about 3 hours until the isocyanate group content became constant, and NCO% A moisture-curable polyurethane adhesive (X-1) containing the urethane prepolymer of 4.1 was obtained.

[Synthesis Example 6] Synthesis of moisture-curing polyurethane adhesive (X-2) 17 parts by mass of polycarbonate polyol (1) and 40 parts of PEG #4000 (manufactured by NOF Corporation) were placed in a reaction apparatus equipped with a stirrer, a reflux tube, and a thermometer. Parts by mass, 21 parts by mass of PES-1 (manufactured by DIC: MX-2913), 21 parts by mass of PES-2 (manufactured by DIC: MX-2906), and 1 part by mass of PET-1 (manufactured by Mitsui Chemicals Polyurethane: T-700). In addition, dehydration was performed under reduced pressure conditions until the water content became 0.05% by mass or less. Next, after cooling the container internal temperature to 70°C, 27 parts by mass of 4,4'-diphenylmethane diisocyanate was added, and the temperature was raised to 100°C, and the reaction was carried out for about 3 hours until the isocyanate group content became constant, and NCO% A moisture-curable polyurethane adhesive (X-2) containing a 4.0 urethane prepolymer was obtained.

[Synthesis Example 7] Synthesis of moisture-curing polyurethane adhesive (X-3) 28 parts by mass of polycarbonate polyol (1) and 28 parts by mass of PEG #4000 (manufactured by NOF Corporation) were placed in a reaction apparatus equipped with a stirrer, a reflux tube, and a thermometer. Parts by mass, 21 parts by mass of PES-1 (manufactured by DIC: MX-2913), 21 parts by mass of PES-2 (manufactured by DIC: MX-2906), and 1 part by mass of PET-1 (manufactured by Mitsui Chemicals Polyurethane: T-700). In addition, dehydration was performed under reduced pressure conditions until the water content became 0.05% by mass or less. Next, after cooling the container internal temperature to 70°C, 28 parts by mass of 4,4'-diphenylmethane diisocyanate was added, the temperature was raised to 100°C, and the reaction was carried out for about 3 hours until the isocyanate group content became constant, and NCO% A moisture-curable polyurethane adhesive (X-3) containing a 4.0 urethane prepolymer was obtained.

[Synthesis Example 8] Synthesis of moisture-curing polyurethane adhesive (X-4) 28 parts by mass of polycarbonate polyol (2) and 28 parts by mass of PEG #4000 (manufactured by NOF Corporation) were placed in a reaction apparatus equipped with a stirrer, a reflux tube, and a thermometer. Parts by mass, 21 parts by mass of PES-1 (manufactured by DIC: MX-2913), 21 parts by mass of PES-2 (manufactured by DIC: MX-2906), and 1 part by mass of PET-1 (manufactured by Mitsui Chemicals Polyurethane: T-700). In addition, dehydration was performed under reduced pressure conditions until the water content became 0.05% by mass or less. Next, after cooling the container internal temperature to 70°C, 28 parts by mass of 4,4'-diphenylmethane diisocyanate was added, the temperature was raised to 100°C, and the reaction was carried out for about 3 hours until the isocyanate group content became constant, and NCO% A moisture-curing polyurethane adhesive (X-4) containing a urethane prepolymer of 3.9 was obtained.

[Synthesis Example 9] Synthesis of moisture-curing polyurethane adhesive (X-5) 28 parts by mass of polycarbonate polyol (3) and 28 parts by mass of PEG #4000 (manufactured by NOF Corporation) were placed in a reaction apparatus equipped with a stirrer, a reflux tube, and a thermometer. Parts by mass, 21 parts by mass of PES-1 (manufactured by DIC: MX-2913), 21 parts by mass of PES-2 (manufactured by DIC: MX-2906), and 1 part by mass of PET-1 (manufactured by Mitsui Chemicals Polyurethane: T-700). In addition, dehydration was performed under reduced pressure conditions until the water content became 0.05% by mass or less. Next, after cooling the container internal temperature to 70°C, 27 parts by mass of 4,4'-diphenylmethane diisocyanate was added, and the temperature was raised to 100°C, and the reaction was carried out for about 3 hours until the isocyanate group content became constant, and NCO% A moisture-curable polyurethane adhesive (X-5) containing the urethane prepolymer of 4.1 was obtained.

[Synthesis Example 10] Synthesis of moisture-curing polyurethane adhesive (X-6) 28 parts by mass of polycarbonate polyol (4) and 28 parts by mass of PEG #4000 (manufactured by NOF Corporation) were placed in a reaction apparatus equipped with a stirrer, a reflux tube, and a thermometer. Parts by mass, 21 parts by mass of PES-1 (manufactured by DIC: MX-2913), 21 parts by mass of PES-2 (manufactured by DIC: MX-2906), and 1 part by mass of PET-1 (manufactured by Mitsui Chemicals Polyurethane: T-700). In addition, dehydration was performed under reduced pressure conditions until the water content became 0.05% by mass or less. Next, after cooling the container internal temperature to 70°C, 27 parts by mass of 4,4'-diphenylmethane diisocyanate was added, and the temperature was raised to 100°C, and the reaction was carried out for about 3 hours until the isocyanate group content became constant, and NCO% A moisture-curable polyurethane adhesive (X-6) containing the urethane prepolymer of 4.1 was obtained.

[Synthesis Example 11] Synthesis of moisture-curing polyurethane adhesive (X'-1) 57 parts by mass of PEG #4000 (manufactured by NOF) and PES-1 (DIC) were placed in a reaction apparatus equipped with a stirrer, a reflux tube, and a thermometer. 21 parts by mass of PES-2 (manufactured by DIC: MX-2906) and 1 part by mass of PET-1 (manufactured by Mitsui Chemicals Polyurethane: T-700) were added, and water was added under reduced pressure conditions. Dehydration was carried out until the percentage was 0.05% by mass or less. Next, after cooling the container internal temperature to 70°C, 27 parts by mass of 4,4'-diphenylmethane diisocyanate was added, the temperature was raised to 100°C, and the reaction was carried out for about 3 hours until the isocyanate group content became constant, and NCO% A moisture-curable polyurethane adhesive (X'-1) containing the urethane prepolymer of 4.2 was obtained.

[Synthesis Example 12] Synthesis of moisture-curable polyurethane adhesive (X'-2) 21 parts by mass of PES-1 (manufactured by DIC: MX-2913) and PES- 2 (manufactured by DIC: MX-2906) and 1 part by mass of PET-1 (manufactured by Mitsui Chemicals Polyurethane: T-700) were added and dehydrated under reduced pressure conditions until the water content became 0.05% by mass or less. did. Next, after cooling the container internal temperature to 70°C, 26 parts by mass of 4,4'-diphenylmethane diisocyanate was added, the temperature was raised to 100°C, and the reaction was carried out for about 3 hours until the isocyanate group content became constant, and NCO% A moisture-curable polyurethane adhesive (X'-2) containing a urethane prepolymer of 3.9 was obtained.

[Example 1]
The moisture-curable polyurethane adhesive (X-1) obtained in Synthesis Example 5 was heated and melted at 110°C, coated on a 100 μm thick PET (polyethylene terephthalate) film at a thickness of 80 μm, and then The same PET film was placed and bonded to obtain a laminate. In addition, a moisture-curing polyurethane adhesive (X-1) was melted by heating at 110°C, and coated on release paper to a thickness of 80 μm using a knife coater heated to 110°C, and then subjected to moisture-curing treatment (temperature 23°C). ℃ and 65% relative humidity for 3 days) to prepare a film.

[Examples 2 to 6, Comparative Examples 1 and 2]
A laminate and film (Y- 2) - (Y-6), (Y'-1) and (Y'-2) were obtained.

[Evaluation method of adhesive strength]
The laminates obtained in Examples and Comparative Examples were cured for 10 days at 23°C and 50% humidity, and then peeled at a speed of 200 mm/min in a 180° direction with respect to a 25 mm width. Peel strength was measured and evaluated as follows.
◎: Peel strength is 15 N/25 mm or more.
○: Peel strength is 10 N/25 mm or more and less than 15 N/25 mm.
×; Peel strength is less than 10 N/25 mm.

[Measurement method of moisture permeability]
Using the films obtained in Examples and Comparative Examples as test specimens, the moisture permeability is measured using the measurement method specified in JIS L-1099 A-1 method.
○; 1,000g/m ² -24h or more
△; 750g/m ² -24h or more 1000g/m ² Less than -24h ×: 750g/m ² Less than -24h

The moisture-curing adhesives of Examples 1 to 6 are moisture-curing adhesives of the present invention, and were able to improve adhesive strength while maintaining humidity.

On the other hand, the moisture-curable adhesive of Comparative Example 1 was formed using a polyol that did not contain the polycarbonate polyl (a1) having a unit derived from the hydroxy compound (d1) represented by the general formula (1). The adhesive strength was poor.

The moisture-curable adhesive of Comparative Example 2 was formed using a polyol that did not contain the polycarbonate polyl (a1) having a unit derived from the hydroxy compound (d1) represented by the general formula (1). , the moisture permeability was poor.

Claims (5)

A moisture-curing adhesive comprising a urethane prepolymer having an isocyanate group,
The urethane prepolymer having an isocyanate group is a reaction product of a polyol (A) and a polyisocyanate (B),
The polyol (A) contains a polycarbonate polyol (a1) having a unit derived from a hydroxy compound (d1) represented by the general formula (1),
A moisture-curable adhesive characterized in that the hydroxy compound (d1) is diethylene glycol, triethylene glycol, or triethylene glycol , and contains 20% by mass or more of triethylene glycol .

[In general formula (1), n represents an integer of 2 or more and 7 or less. ] The moisture-curable adhesive according to claim 1, wherein the content of the polycarbonate polyol (a1) in the polyol (A) is 10% by mass or more. The moisture-curable adhesive according to claim 1 or 2, wherein the polycarbonate polyol (a1) has a number average molecular weight of 500 or more and 8,000 or less. The moisture-curable adhesive according to any one of claims 1 to 3, wherein the content of the compound (d1) is 40% by mass or more in the hydroxy compound (D) that is a raw material for the polycarbonate polyol (a1). . A laminate comprising a cured product layer of the moisture-curable adhesive according to any one of claims 1 to 4.