Polyisocyanate composition, cured film, coating film, adhesive composition, adhesive sheet and resin composition

Abstract

The present invention provides a polyisocyanate composition, etc., which is derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, a bifunctional polyol (A1) having a number average molecular weight of 1500 or more, and a trifunctional or higher polyol (B1) having a number average molecular weight of 500 or more, wherein the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl groups of the polyol (A1) and the polyol (B1) is 2 or more and 30 or less, and the weight average molecular weight of the polyisocyanate composition is 1400 or more. In addition, the present invention provides a polyisocyanate composition, etc., which is derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, a polycaprolactone polyol (A2), and a polyether polyol (B2), and contains 20 parts by mass or more of polypropylene glycol relative to 100 parts by mass of the polyether polyol (B2).

Description

Technical Field

[0001] The present invention relates to a polyisocyanate composition, a cured film, a coating film, an adhesive composition and an adhesive sheet. The present invention also relates to a polyisocyanate composition and a resin composition. Background Art

[0002] In recent years, plastic films, adhesives, and bonding agents have been used in various fields due to their wide range of functions. Under such circumstances, applications are increasing not only to flat plate-like parts, but also to parts that were previously less frequently used, such as curved parts and parts with folding movements. For example, devices such as flexible displays and foldable displays are listed, and demand has been growing rapidly in recent years. As a result, films, adhesives, and bonding agents with high flexibility that have good bending tracking properties and excellent bending resistance are sought.

[0003] In addition, for curable polyurethanes, in order to achieve coating properties that could not be achieved with conventional curing agents, the market demand for higher quality and higher performance of curing agents is increasing. In particular, for coatings, adhesives, bonding agents, sealants, etc. that exhibit final physical properties through curing, further development is required to better utilize the performance derived from curing agents. In particular, as a market trend, there is a tendency to require high flexibility for cured compositions.

[0004] Patent Documents 1 and 2 disclose polyisocyanate compositions modified with polyester polyol or polyether polyol, and disclose that coating films formed by blending the compositions have excellent stretchability and flex resistance.

[0005] Prior art literature

[0006] Patent Literature

[0007] Patent Document 1: Japanese Patent Application Publication No. 61-28518

[0008] Patent Document 2: Japanese Patent Application Laid-Open No. 2-1718 Summary of the invention

[0009] Problem that the invention aims to solve

[0010] There is a demand for a polyisocyanate composition having better flexibility than the polyisocyanate compositions described in Patent Documents 1 and 2. In addition, Patent Documents 1 and 2 do not specifically study the use in adhesives and pressure-sensitive adhesives.

[0011] The present invention is made in view of the above circumstances, and aims to provide a polyisocyanate composition, wherein a cured film formed by curing the polyisocyanate composition alone has good flexibility and can obtain an adhesive sheet having excellent adhesion, cohesion, curability and transparency. In addition, a cured film, a coating film, an adhesive composition and an adhesive sheet using the polyisocyanate composition are provided.

[0012] Furthermore, there is a demand for a polyisocyanate composition that can provide a coating film having better flexibility under a severe environment, specifically, at a low temperature of about -10°C, compared with the polyisocyanate compositions described in Patent Documents 1 and 2.

[0013] The present invention is made in view of the above circumstances, and provides a polyisocyanate composition which has good compatibility with a main agent in a low temperature environment of about -10°C and has excellent flexibility at a low temperature of about -10°C and a room temperature of about 23°C when formed into a coating film. In addition, a resin composition using the above polyisocyanate composition is provided.

[0014] Solutions for solving problems

[0015] That is, the present invention includes the following aspects.

[0016] (1) A polyisocyanate composition derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, a bifunctional polyol (A1) having a number average molecular weight of 1500 or more, and a trifunctional or higher polyol (B1) having a number average molecular weight of 500 or more,

[0017] The molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyol (A1) and the polyol (B1) is 2 or more and 30 or less,

[0018] The weight average molecular weight of the polyisocyanate composition is 1400 or more.

[0019] (2) The polyisocyanate composition according to (1), wherein the mass ratio of the polyol (B1) to the polyol (A1) is 0.1 / 99.9 or more and 99.9 / 0.1 or less, and

[0020] With respect to 100 parts by mass of the above diisocyanate,

[0021] The content of the polyol (A1) is 0.1 parts by mass or more and 250 parts by mass or less,

[0022] The content of the polyol (B1) is 1 part by mass or more and 190 parts by mass or less.

[0023] (3) The polyisocyanate composition according to (1) or (2), wherein the average number of isocyanate functional groups in the polyisocyanate composition is 2 or more and 6 or less.

[0024] (4) The polyisocyanate composition according to any one of (1) to (3), wherein the isocyanate group content of the polyisocyanate composition is 1% by mass or more and 10% by mass or less.

[0025] (5) The polyisocyanate composition according to any one of (1) to (4), wherein the polyol (A1) and the polyol (B1) are at least one polyol selected from the group consisting of polyester polyols, polyether polyols, epoxy polyols, polyolefin polyols and polycarbonate polyols.

[0026] (6) The polyisocyanate composition according to any one of (1) to (5), wherein the polyol (A1) and the polyol (B1) are polyester polyols.

[0027] (7) The polyisocyanate composition according to (6), wherein the polyol (A1) and the polyol (B1) are polycaprolactone polyols.

[0028] (8) A cured film having a thickness of 40 μm formed by applying the polyisocyanate composition according to any one of (1) to (7) onto glass, storing the film at 23° C. and 65% humidity for 168 hours, and then heating the film at 50° C. for 24 hours,

[0029] The cured film has a Koenig hardness of 60 times or less under a 23°C environment.

[0030] (9) A coating film having a thickness of 40 μm after the coating composition is cured at 90° C. for 30 minutes and stored at 23° C. and 65% humidity for 168 hours, the coating composition comprising the polyisocyanate composition described in any one of (1) to (7) and a polyisocyanate having a glass transition temperature of 29.1° C., a hydroxyl value of 139 mgKOH / g and a weight average molecular weight of 2.56×10 4 Acrylic polyols,

[0031] In a tensile test in which a test piece of the coating film having a width of 10 mm and a length of 100 mm was set in a tensile testing machine with a clamp distance of 20 mm and measured at a speed of 20 mm / min, the elongation of the coating film was 50% or more and the stress at an elongation of 140% was 28 MPa or less.

[0032] (10) An adhesive composition comprising the polyisocyanate composition according to any one of (1) to (7) and a crosslinkable functional group-containing polymer having a glass transition temperature of 0° C. or less.

[0033] (11) The pressure-sensitive adhesive composition according to (10), wherein the crosslinkable functional group-containing polymer is an acrylic polymer.

[0034] (12) A pressure-sensitive adhesive sheet comprising:

[0035] substrate; and

[0036] an adhesive layer located on the aforementioned substrate,

[0037] The adhesive layer comprises a cured product of the adhesive composition described in (10) or (11).

[0038] (13) The pressure-sensitive adhesive sheet according to (12), wherein the pressure-sensitive adhesive layer has a thickness of 1 μm to 1000 μm.

[0039] (14) An adhesive sheet according to (12) or (13), wherein the adhesive sheet having an adhesive layer with a thickness of 50 μm is stored in an environment of 23°C and 50% RH for 7 days, then wrapped with a mesh sheet, immersed in ethyl acetate at 23°C for 1 week, taken out and dried at 120°C for 2 hours, and the gel fraction calculated is 20% by mass or more and 99% by mass or less, and the adhesive sheet having an adhesive layer with a thickness of 50 μm is formed by coating the aforementioned adhesive composition on a 38 μm thick release-treated polyethylene terephthalate film and drying it at 130°C for 3 minutes to cure it.

[0040] (15) An adhesive sheet according to any one of (12) to (14), wherein the adhesive sheet having a width of 20 mm and a length of 100 mm and having an adhesive layer having a thickness of 50 μm is stored at 23°C and 50% RH for 7 days, and then crimped using a SUS304BA steel plate as an adherend by reciprocating a 2 kg roller, and after aging at 23°C for 30 minutes, the 180 degree peel adhesion measured at a speed of 300 mm / min at 23°C is 0.05 N / 20 mm or more and 55 N / 20 mm or less, wherein the adhesive sheet having a width of 20 mm and a length of 100 mm and having an adhesive layer having a thickness of 50 μm is formed by coating the above-mentioned adhesive composition on a polyethylene terephthalate film having a thickness of 25 μm and drying and curing it at 130°C for 3 minutes.

[0041] (16) An adhesive sheet according to any one of (12) to (15), wherein a 50 μm thick adhesive layer formed by coating the adhesive composition on a 38 μm thick release-treated polyethylene terephthalate film and drying it at 130°C for 3 minutes to cure it is peeled off from the release-treated polyethylene terephthalate film and then bonded to glass having a haze value of 0.1%, and the haze value of the adhesive sheet obtained thereby, as measured by a haze meter, is less than 2%.

[0042] (17) A coating film, a film, and an adhesive composition, wherein the resin composition is cured at 90°C for 30 minutes and stored at 23°C and 65% humidity for 168 hours to obtain a resin film having a thickness of 40 μm, the resin composition comprising the polyisocyanate composition described in any one of (1) to (7) and a polyisocyanate having a glass transition temperature of 0°C to 100°C, a hydroxyl value of 10 mgKOH / g to 400 mgKOH / g, and a weight average molecular weight of 5.00×10 3 Above and 1.0×10 5 The following acrylic polyols,

[0043] In a tensile test in which a test piece of the resin film having a width of 10 mm and a length of 100 mm was set in a tensile testing machine with a clamp distance of 20 mm and measured at a speed of 20 mm / min, the breaking stress of the resin film was 2.0 MPa or more.

[0044] (18) A coating film, a film, and an adhesive composition, wherein the resin composition is cured at 90°C for 30 minutes and stored at 23°C and 65% humidity for 168 hours to obtain a resin film having a thickness of 40 μm, the resin composition comprising the polyisocyanate composition described in any one of (1) to (7) and a polyisocyanate having a glass transition temperature of 0°C to 100°C, a hydroxyl value of 10 mgKOH / g to 400 mgKOH / g, and a weight average molecular weight of 5.00×10 3 Above and 1.0×10 5 The following acrylic polyols,

[0045] In a tensile test in which a test piece of the resin film having a width of 10 mm and a length of 100 mm was set in a tensile testing machine with a clamp distance of 20 mm and measured at a speed of 20 mm / min, the breaking stress of the resin film was 1.1 or more relative to the stress at 140% elongation.

[0046] (19) A polyisocyanate composition derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, a polycaprolactone polyol (A2) and a polyether polyol (B2),

[0047] The polypropylene glycol is contained in an amount of 20 parts by mass or more based on 100 parts by mass of the polyether polyol (B2).

[0048] (20) The polyisocyanate composition according to (19), wherein the number average molecular weight of the polycaprolactone polyol (A2) is 500 or more and 1500 or less, and

[0049] The number average molecular weight of the polyether polyol (B2) is 1,000 or more and 7,000 or less.

[0050] (21) The polyisocyanate composition according to (20), wherein in the polyether polyol (B2), a mass ratio of polytetramethylene ether glycol to polypropylene glycol is 0 / 100 or more and 60 / 40 or less.

[0051] (22) The polyisocyanate composition according to any one of (19) to (21), wherein the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polycaprolactone polyol (A2) and the polyether polyol (B2) is 2 or more and 10 or less.

[0052] (23) The polyisocyanate composition according to any one of (19) to (22), wherein the mass ratio of the polycaprolactone polyol (A2) to the polyether polyol (B2) is 10 / 90 or more and 90 / 10 or less.

[0053] (24) A resin composition comprising the polyisocyanate composition according to any one of (19) to (23) and a polyol.

[0054] (25) The resin composition according to (24), which is an adhesive composition.

[0055] Effects of the Invention

[0056] According to the polyisocyanate composition of the above aspect, it is possible to provide a polyisocyanate composition which can provide a PSA sheet having good flexibility and excellent adhesiveness, cohesive force, curability and transparency by curing a cured film formed by curing the polyisocyanate composition alone.

[0057] In addition, according to the polyisocyanate composition of the above embodiment, a polyisocyanate composition can be provided, which has good compatibility with a main agent in a low temperature environment of about -10°C and has excellent flexibility at a low temperature of about -10°C and a room temperature of about 23°C when formed into a coating film. The resin composition of the above embodiment includes the above polyisocyanate composition, and has excellent flexibility at a low temperature of about -10°C and a room temperature of about 23°C when formed into a coating film. DETAILED DESCRIPTION

[0058] The following is a detailed description of a method for implementing the present invention (hereinafter referred to as "this embodiment"). The following this embodiment is an example for illustrating the present invention and is not intended to limit the present invention to the following content. The present invention can be modified in various ways without departing from the scope of its purpose.

[0059] In addition, in this specification, "polyol" refers to a compound having two or more hydroxyl groups (-OH) in one molecule.

[0060] In addition, in this specification, "polyisocyanate" means a reaction product in which a plurality of monomer compounds having two or more isocyanate groups (-NCO) are bonded to each other.

[0061] In the present specification, unless otherwise specified, "(meth)acryl*" includes methacryl* and acryl*, and "(meth)acrylate" includes methacrylate and acrylate.

[0062] "Polyisocyanate composition 1"

[0063] The polyisocyanate composition 1 of the present embodiment is derived from a diisocyanate, a bifunctional polyol (A1) having a number average molecular weight of 1500 or more (hereinafter referred to as "polyol (A1)"), and a trifunctional or higher polyol (B1) having a number average molecular weight of 500 or more (hereinafter referred to as "polyol (B1)"). That is, the polyisocyanate composition 1 of the present embodiment is a reaction product of a diisocyanate and the above two polyols, and includes a polyisocyanate modified by the above two polyols. The diisocyanate is at least one selected from the group consisting of an aliphatic diisocyanate and an alicyclic diisocyanate.

[0064] In the polyisocyanate composition 1 of the present embodiment, the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyol (A1) and the polyol (B1) (molar ratio of isocyanate group / hydroxyl group) is 2 or more and 30 or less, preferably 2.6 or more and 30 or less, more preferably 3 or more and 25 or less, further preferably 3.5 or more and 24 or less, particularly preferably 5 or more and 23 or less, and most preferably 5 or more and 20 or less.

[0065] The molar ratio of isocyanate group / hydroxyl group can be calculated using, for example, the molar amount of hydroxyl groups of the polyol (A1) and the polyol (B1) used in producing the polyisocyanate composition 1 and the molar amount of isocyanate groups of the diisocyanate.

[0066] The weight average molecular weight of the polyisocyanate composition 1 of the present embodiment is 1400 or more, preferably 1500 or more.

[0067] The upper limit of the weight average molecular weight of the polyisocyanate composition 1 of the present embodiment is not particularly limited, and can be 100,000.

[0068] The weight average molecular weight of the polyisocyanate composition 1 of the present embodiment can be measured by, for example, gel permeation chromatography (hereinafter, sometimes abbreviated to "GPC").

[0069] Since the polyisocyanate composition 1 of the present embodiment has the above-mentioned structure, it shows higher flexibility than before, and the cured film formed by curing the polyisocyanate composition 1 alone has good flexibility. In addition, by using the polyisocyanate composition 1 of the present embodiment, an adhesive sheet having excellent adhesiveness, cohesive force, curability and transparency can be obtained.

[0070] Next, the details of each constituent component of the polyisocyanate composition 1 of the present embodiment will be described below.

[0071] <Polyisocyanate>

[0072] The polyisocyanate composition 1 of the present embodiment may be a polyisocyanate having structural units derived from each of diisocyanate, polyol (A1) and polyol (B1) in one molecule, or may be a mixture of polyisocyanates having structural units derived from at least one selected from the group consisting of diisocyanate, polyol (A1) and polyol (B1) in one molecule.

[0073] The polyisocyanate may have at least one structure selected from the group consisting of an allophanate structure, a uretdione structure, an iminooxadiazinedione structure, an isocyanurate structure, a urea structure, a carbamate structure, and a biuret structure. Among them, it is preferred to have at least one structure selected from the group consisting of a carbamate structure, an allophanate structure, a biuret structure, a urea structure, and an isocyanurate group, and more preferably contain a carbamate structure.

[0074] [Diisocyanate]

[0075] The diisocyanate is at least one selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

[0076] The aliphatic diisocyanate is not limited to the following, and examples thereof include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, ethyl (2,6-diisocyanato)hexanoate, 1,6-diisocyanatohexane (hereinafter sometimes referred to as "HDI"), 1,9-diisocyanatononane, 1,12-diisocyanatododecane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane, etc. These aliphatic diisocyanates may be used alone or in combination of two or more.

[0077] Examples of the alicyclic diisocyanate include, but are not limited to, 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane (hereinafter sometimes referred to as "hydrogenated XDI"), 1,3- or 1,4-diisocyanatocyclohexane, 3,5,5-trimethyl1-isocyanato-3-(isocyanatomethyl)cyclohexane (hereinafter sometimes referred to as "IPDI"), 4-4'-diisocyanato-dicyclohexylmethane (hereinafter sometimes referred to as "hydrogenated MDI"), 2,5- or 2,6-diisocyanatomethylnorbornane, etc. These alicyclic diisocyanates may be used alone or in combination of two or more.

[0078] These aliphatic diisocyanates and alicyclic diisocyanates may be used alone or in combination of two or more.

[0079] From the viewpoint of flexibility, the mass ratio of the alicyclic polyisocyanate to the aliphatic diisocyanate is preferably 0 / 100 or more and 30 / 70 or less.

[0080] Among them, as the diisocyanate, HDI, IPDI, hydrogenated XDI or hydrogenated MDI is preferred, HDI or IPDI is more preferred, and HDI is further preferred.

[0081] In the production of polyisocyanate, in addition to the above-mentioned diisocyanate, isocyanate monomers as shown below may be used.

[0082] (1) Aromatic diisocyanates such as diphenylmethane-4,4'-diisocyanate (MDI), 1,5-naphthalene diisocyanate, toluene diisocyanate (TDI), xylylene diisocyanate, and m-tetramethylxylylene diisocyanate (TMXDI).

[0083] (2) Triisocyanates such as 4-isocyanatemethyl-1,8-octamethylene diisocyanate (hereinafter sometimes referred to as "NTI"), 1,3,6-hexamethylene triisocyanate (hereinafter sometimes referred to as "HTI"), bis(2-isocyanatoethyl) 2-isocyanatoglutarate (hereinafter referred to as "GTI"), and lysine triisocyanate (hereinafter sometimes referred to as "LTI").

[0084] [Polyol (A1) and Polyol (B1)]

[0085] The polyol (A1) is a bifunctional polyol (diol) having a number average molecular weight of 1,500 or more.

[0086] The polyol (B1) is a trifunctional or higher polyol having a number average molecular weight of 500 or more.

[0087] The number average molecular weight of the polyol (A1) is 1500 or more, preferably 1800 or more. When the number average molecular weight of the polyol (A1) is at least the above lower limit, a cured film obtained by curing the polyisocyanate composition alone has low hardness and good flexibility.

[0088] On the other hand, the upper limit of the number average molecular weight of the polyol (A1) is not particularly limited, and may be, for example, 7,000, preferably 6,000, more preferably 5,000, and further preferably 4,200.

[0089] The number average molecular weight Mn of the polyol (A1) is, for example, a number average molecular weight based on polystyrene measured by GPC. When two or more polyols (A1) are mixed for use, the number average molecular weight of the mixture is calculated.

[0090] The number average molecular weight of the polyol (B1) is 500 or more, preferably 800 or more. When the number average molecular weight of the polyol (B1) is equal to or more than the above lower limit, a cured film obtained by curing the polyisocyanate composition alone has low hardness and good flexibility.

[0091] On the other hand, the upper limit of the number average molecular weight of the polyol (B1) is not particularly limited, and may be, for example, 3,000, preferably 2,200, more preferably 1,500, and further preferably 1,300.

[0092] The number average molecular weight Mn of the polyol (B1) is, for example, a number average molecular weight based on polystyrene measured by GPC. When two or more polyols (B1) are mixed for use, the number average molecular weight of the mixture is calculated.

[0093] The polyol (A1) is preferably at least one bifunctional polyol (diol) selected from the group consisting of polyester polyols, polyether polyols, epoxy polyols, polyolefin polyols and polycarbonate polyols, and more preferably a bifunctional polyester polyol.

[0094] Examples of the bifunctional polyester polyol include any of the following (1) or (2). (1) A polyester polyol obtained by condensation reaction of a dibasic acid alone or a mixture of two or more thereof with a diol alone or a mixture of two or more thereof. (2) A polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone using a diol.

[0095] Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.

[0096] Examples of the diol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, and cyclohexanediol.

[0097] Among them, as the bifunctional polyester polyol, bifunctional polycaprolactone polyol is preferred.

[0098] Examples of commercially available bifunctional polycaprolactone polyols include PLACCEL 210 (number average molecular weight 1000, hydroxyl value 112.8 mgKOH / g, acid value 0.09 mgKOH / g), PLACCEL 210CP (number average molecular weight 1000, hydroxyl value 112.8 mgKOH / g, acid value 0.16 mgKOH / g), PLACCEL 212 (number average molecular weight 1250, hydroxyl value 90.8 mgKOH / g, acid value 0.09 mgKOH / g), PLACCEL 212CP (number average molecular weight 1250, hydroxyl value 90.2 mgKOH / g, acid value 0.14 mgKOH / g), PLACCEL 220 (number average molecular weight 2000, hydroxyl value 56.7 mgKOH / g, acid value 0.06 mgKOH / g), PLACCEL 221CP (number average molecular weight 1250, hydroxyl value 90.8 mgKOH / g, acid value 0.09 mgKOH / g), and PLACCEL 222CP (number average molecular weight 1250, hydroxyl value 90.2 mgKOH / g, acid value 0.14 mgKOH / g). "PLACCEL 220CPB" (number average molecular weight 2000, hydroxyl value 57.2 mgKOH / g, acid value 0.16 mgKOH / g), "PLACCEL 220CPT" (number average molecular weight 2000, hydroxyl value 56.6 mgKOH / g, acid value 0.02 mgKOH / g), "PLACCEL 230" (number average molecular weight 3000, hydroxyl value 37.6 mgKOH / g, acid value 0.07 mgKOH / g), "PLACCEL 240 (number average molecular weight 4000, hydroxyl value 28.5 mgKOH / g, acid value 0.07 mgKOH / g), etc.

[0099] As the bifunctional polycaprolactone polyol, it is preferred to use one having a relatively low acid value from the viewpoint of hydrolysis resistance and reaction stability during synthesis of polyisocyanate.

[0100] The polyol (B1) may be a trifunctional or higher polyol, preferably a trifunctional or higher to decafunctional or lower polyol, more preferably a trifunctional or higher to heptafunctional or lower polyol, further preferably a trifunctional or higher to pentafunctional or lower polyol, particularly preferably a trifunctional or higher to tetrafunctional or lower polyol, and most preferably a trifunctional polyol (triol).

[0101] The trifunctional polyol (triol) is preferably at least one trifunctional polyol (triol) selected from the group consisting of polyester polyols, polyether polyols, epoxy polyols, polyolefin polyols, and polycarbonate polyols, and more preferably a trifunctional polyester polyol.

[0102] Examples of the trifunctional polyester polyol include any of the following (1) or (2). (1) A polyester polyol obtained by condensation reaction of a dibasic acid alone or a mixture of two or more thereof with a triol alone or a mixture of two or more thereof. (2) A polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone using a triol.

[0103] Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.

[0104] Examples of the triol include trimethylolpropane, glycerin, pentaerythritol, 2-methylolpropanediol, and ethoxylated trimethylolpropane.

[0105] Among them, as the trifunctional polyester polyol, a trifunctional polycaprolactone polyol is preferred.

[0106] Examples of commercially available trifunctional polycaprolactone polyols include "PLACCEL 305" (number average molecular weight 550, hydroxyl value 305.6 mgKOH / g, acid value 0.50 mgKOH / g), "PLACCEL 308" (number average molecular weight 850, hydroxyl value 195.3 mgKOH / g, acid value 0.38 mgKOH / g), "PLACCEL 309" (number average molecular weight 900, hydroxyl value 187.3 mgKOH / g, acid value 0.20 mgKOH / g), "PLACCEL 312" (number average molecular weight 1250, hydroxyl value 136.1 mgKOH / g, acid value 0.38 mgKOH / g), and "PLACCEL 320" (number average molecular weight 2000, hydroxyl value 85.4 mgKOH / g, acid value 0.29 mgKOH / g) manufactured by Daicel Corporation.

[0107] In the polyisocyanate composition 1 of the present embodiment, the mass ratio of the polyol (A1) to the polyol (B1) (mass ratio of (A1) / (B1)) is preferably 0.1 / 99.9 or more and 99.9 / 0.1, more preferably 1 / 99 or more and 99 / 1 or less, further preferably 3 / 97 or more and 90 / 10 or less, particularly preferably 5 / 95 or more and 80 / 20 or less, and most preferably 7 / 93 or more and 70 / 30 or less.

[0108] By making the mass ratio of (A1) / (B1) be above the above lower limit, the hardness of the cured film formed by curing the polyisocyanate composition alone is low and the flexibility is better. In addition, an adhesive sheet with better adhesion and flexibility can be obtained. On the other hand, by making the mass ratio of (A1) / (B1) be below the above upper limit, an adhesive sheet with better adhesion, flexibility and cohesion can be obtained.

[0109] The mass ratio of (A1) / (B1) can be calculated from the compounding amounts of the respective polyols when the polyisocyanate composition 1 is produced, for example.

[0110] In the polyisocyanate composition 1 of the present embodiment, the content (charge amount) of the polyol (A1) is 0.1 parts by mass or more and 250 parts by mass or less, preferably 0.1 parts by mass or more and 210 parts by mass or less, more preferably 0.1 parts by mass or more and 170 parts by mass or less, further preferably 0.5 parts by mass or more and 100 parts by mass or less, further preferably 1 parts by mass or more and 50 parts by mass or less, further preferably 1.5 parts by mass or more and 40 parts by mass or less, particularly preferably 1.7 parts by mass or more and 38 parts by mass or less, relative to 100 parts by mass of the diisocyanate.

[0111] By making the content of polyol (A1) be above the above lower limit, the hardness of the cured film formed by curing the polyisocyanate composition alone is low and the flexibility is better. In addition, an adhesive sheet with more excellent adhesion and curability can be obtained. On the other hand, by making the content of polyol (A1) be below the above upper limit, it will not gel when manufacturing polyisocyanate composition 1, can maintain a liquid state, and the flexibility is better when making a resin film.

[0112] The content of the polyol (A1) can be calculated from the amounts of the diisocyanate and the polyol (A1) blended when the polyisocyanate composition 1 is produced, for example.

[0113] In the polyisocyanate composition 1 of the present embodiment, the content (charge amount) of the polyol (B1) is 1 part by mass or more and 190 parts by mass or less, preferably 1 part by mass or more and 140 parts by mass or less, more preferably 1 part by mass or more and 90 parts by mass or less, further preferably 2 parts by mass or more and 80 parts by mass or less, further preferably 5 parts by mass or more and 70 parts by mass or less, further preferably 10 parts by mass or more and 60 parts by mass or less, and particularly preferably 12 parts by mass or more and 50 parts by mass or less.

[0114] By making the content of the polyol (B1) below the above upper limit, the isocyanate composition 1 will not gel when it is manufactured, and can maintain a liquid state, and the curability and flexibility are better when it is made into a resin film. On the other hand, by making the content of the polyol (B1) above the above lower limit, the hardness of the cured film formed by curing the polyisocyanate composition alone is low and the flexibility is better. In addition, an adhesive sheet with better adhesion and curability can be obtained.

[0115] The content of the polyol (B1) can be calculated from the amounts of the diisocyanate and the polyol (B1) added when the isocyanate composition 1 is prepared, for example.

[0116] <Method for producing polyisocyanate composition 1>

[0117] The polyisocyanate is obtained by reacting the above-mentioned diisocyanate, polyol (A1) and polyol (B1). Hereinafter, the polyol (A1) and the polyol (B1) may be collectively referred to as polyol.

[0118] The polyol (A1) and the polyol (B1) may be used alone or in a mixture. When used in a mixture, they may be mixed before reacting with diisocyanate, or each polyol may be reacted with diisocyanate alone to form a polyisocyanate and then mixed.

[0119] That is, examples of the method for producing the polyisocyanate composition 1 include a method of obtaining the polyisocyanate composition 1 by reacting a diisocyanate, a polyol (A1) and a polyol (B1) at the same time; a method of obtaining the polyisocyanate composition 1 by mixing a product obtained by reacting a diisocyanate with a polyol (A1) and a product obtained by reacting a diisocyanate with a polyol (B1); a method of obtaining the polyisocyanate composition 1 by reacting a diisocyanate with a polyol (A1) or a polyol (B1) and then further reacting the remaining polyol. Alternatively, the following method may be used: using these methods, first, a part of the polyol (A1) is added to obtain the polyisocyanate composition 1, and then the remaining polyol (A1) is added to react with the obtained polyisocyanate composition 1 to obtain the polyisocyanate composition 1.

[0120] The amounts of the polyol (A1) and the polyol (B1) to be added are preferably such that the mass ratio of the polyol (A1) to the polyol (B1) falls within the above range.

[0121] During the reaction, the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyol (A1) and the polyol (B1) (molar ratio of isocyanate group / hydroxyl group) is 2 or more and 30 or less, preferably 2.6 or more and 30 or less, more preferably 3 or more and 25 or less, further preferably 3.5 or more and 24 or less, particularly preferably 5 or more and 23 or less, and most preferably 5 or more and 20 or less.

[0122] The reaction of the polyol and the diisocyanate is carried out as described below. The reaction temperature is usually above room temperature (about 23°C) and below 200°C, preferably above 60°C and below 120°C. When the reaction temperature is above the above lower limit, the reaction time is further shortened. On the other hand, when it is below the above upper limit, the viscosity increase of the polyisocyanate caused by undesirable side reactions can be further avoided, and the coloring of the generated polyisocyanate can also be further avoided.

[0123] The reaction may be carried out without a solvent or using any solvent inactive to isocyanate groups. In addition, a known catalyst may be used to promote the reaction between the isocyanate groups and the hydroxyl groups as required.

[0124] <Physical Properties of Polyisocyanate Composition 1>

[0125] The isocyanate group content (NCO group content) of the polyisocyanate composition 1 of the present embodiment is preferably 1% by mass or more and 10% by mass or less, more preferably 1.5% by mass or more and 9.8% by mass or less, further preferably 2.0% by mass or more and 9.6% by mass or less, further preferably 2.5% by mass or more and 9.5% by mass or less, further more preferably 2.75% by mass or more and 9.5% by mass or less, particularly preferably 3.0% by mass or more and 9.5% by mass or less, and most preferably 3.15% by mass or more and 9.5% by mass or less, relative to the total mass of the polyisocyanate composition 1, in a state substantially free of solvent and diisocyanate.

[0126] The NCO group content can be determined, for example, by reacting the isocyanate groups of the polyisocyanate composition 1 with an excess of amine (such as dibutylamine) and back-titrating the excess amine with an acid such as hydrochloric acid.

[0127] From the viewpoint of improving the curability and cohesive force of the adhesive composition, the average number of isocyanate functional groups in the polyisocyanate composition 1 of the present embodiment is preferably 2 to 6, preferably 2 to 5.8, and more preferably 2.5 to 5.5.

[0128] The average number of isocyanate functional groups in the polyisocyanate composition 1 of the present embodiment can be measured using the method described in Examples described later.

[0129] "Cured Film"

[0130] The cured film of the present embodiment is obtained by curing the polyisocyanate composition 1 described above.

[0131] The cured film of the present embodiment has low hardness and good flexibility.

[0132] The cured film of the present embodiment can be produced, for example, by diluting or dissolving the polyisocyanate composition 1 as required with a solvent, applying the composition to an adherend using a coater or the like, drying the composition as required, and curing the composition with heat.

[0133] In the present embodiment, when the cured film is a cured film having a thickness of 40 μm formed by the reaction between the polyisocyanate composition 1 and the water in the air after applying the polyisocyanate composition 1 alone on glass and storing it at 23° C. and 65% humidity for 168 hours and then heating it at 50° C. for 24 hours, the Koenig hardness of the cured film at 23° C. is 60 times or less, preferably 57 times or less, more preferably 55 times or less, and further preferably 54 times or less. When the Koenig hardness is set to the above upper limit or less, the hardness is low and the flexibility is more excellent.

[0134] 《Coating》

[0135] The polyisocyanate composition 1 can also be used as a curing agent component of a coating composition. That is, the coating film of the present embodiment can be formed by curing a coating composition containing the polyisocyanate composition 1 and a polyol.

[0136] The coating film of the present embodiment is made of the polyisocyanate composition 1 and a resin having a glass transition temperature of 29.1° C., a hydroxyl value of 139 mgKOH / g relative to the resin solid content, and a weight average molecular weight of 2.56×10 4 When a coating composition of an acrylic polyol is cured at 90°C for 30 minutes and stored at 23°C and 65% humidity for 168 hours to form a coating film of 40 μm in thickness, in a tensile test in which a test piece of 10 mm in width and 100 mm in length is set in a tensile testing machine with a clamp distance of 20 mm and measured at a speed of 20 mm / min, the elongation of the coating film is 50% or more and the stress at an elongation of 140% is 28 MPa or less. In addition, the elongation is preferably 100% or more, more preferably 130% or more, further preferably 140% or more, and particularly preferably 150% or more. On the other hand, the upper limit of the elongation can be, for example, 300%.

[0137] The stress at the elongation of 140% is preferably 27 MPa or less, more preferably 25 MPa or less, and further preferably 20 MPa or less. On the other hand, the lower limit of the stress at the elongation of 140% can be set to 1 MPa, for example.

[0138] When the elongation is not less than the lower limit and the stress when the elongation is 140% is not more than the upper limit, the flexibility of the coating film is more excellent.

[0139] Adhesive composition

[0140] The adhesive composition of the present embodiment includes the polyisocyanate composition 1 and a crosslinkable functional group-containing polymer having a glass transition temperature of 0° C. or less.

[0141] The adhesive composition of the present embodiment includes the polyisocyanate composition 1, so that a adhesive layer having higher flexibility than conventional ones can be formed, and an adhesive sheet having excellent adhesiveness, cohesive force, curability, and transparency can be obtained.

[0142] Next, the details of each component contained in the adhesive composition of this embodiment are described below.

[0143] <Polymers containing cross-linkable functional groups>

[0144] The glass transition temperature of the crosslinkable functional group-containing polymer is below 0°C, preferably above -70°C and below 0°C, more preferably above -70°C and below -5°C, further preferably above -70°C and below -10°C, and particularly preferably above -70°C and below -15°C. By making the glass transition temperature Tg of the crosslinkable functional group-containing polymer within the above range, there is a tendency for the adhesive composition to have better adhesion and cohesion. Regarding the glass transition temperature of the crosslinkable functional group-containing polymer, for example, the organic solvent and water in the solution in which the crosslinkable functional group-containing polymer is dissolved or dispersed are evaporated under reduced pressure, and then vacuum dried. The obtained substance is measured using a differential scanning calorimeter (DSC) measuring device at a heating rate of 5°C / min, and the obtained value is used as the glass transition temperature.

[0145] The weight average molecular weight Mw of the crosslinkable functional group-containing polymer is preferably 3.0×10 5 Above and 2.5×10 6 Below, more preferably 4.0×10 5 Above and 2.3×10 6 Below, more preferably 4.5×10 5 Above and 2.0×10 6 , particularly preferably 4.5×10 5 Above and 1.8×10 6When the weight average molecular weight of the crosslinkable functional group-containing polymer is within the above range, the adhesive strength, cohesive force and durability of the cured product of the adhesive composition tend to be more excellent. The weight average molecular weight Mw of the polyol can be measured, for example, by the method described in the examples described below.

[0146] As the crosslinkable functional group-containing polymer, any polymer containing a crosslinkable functional group that can react with the isocyanate group of the polyisocyanate composition 1 may be used. Examples of the crosslinkable functional group include a hydroxyl group, a thiol group, an amino group, a carboxyl group, and an epoxy group, among which a hydroxyl group is preferred. That is, as the crosslinkable functional group-containing polymer, a polyol is preferred.

[0147] Specific examples of the crosslinkable functional group-containing polymer include aliphatic hydrocarbon polyols, polyether polyols, polyester polyols, epoxy resins, fluorine-containing polyols, acrylic polymers, and urethane polymers.

[0148] Among them, as the crosslinkable functional group-containing polymer, an acrylic polymer is preferred.

[0149] [Aliphatic hydrocarbon polyol]

[0150] Examples of the aliphatic hydrocarbon polyol include terminal hydroxylated polybutadiene and hydrogenated products thereof.

[0151] [Polyether polyol]

[0152] Examples of the polyether polyol include polyether polyols obtained by any of the following methods (1) to (3). (1) Polyether polyols or polytetramethylene ether glycols obtained by adding alkylene oxides alone or in a mixture thereof to polyols alone or in a mixture thereof. (2) Polyether polyols obtained by reacting a polyfunctional compound with an alkylene oxide. (3) So-called polymer polyols obtained by polymerizing acrylamide or the like using the polyether polyols obtained in (1) or (2) as a medium.

[0153] Examples of the polyol include glycerin and propylene glycol.

[0154] Examples of the alkylene oxide include ethylene oxide and propylene oxide.

[0155] Examples of the polyfunctional compound include ethylenediamine and ethanolamine.

[0156] [Polyester polyol]

[0157] Examples of the polyester polyol include any of the following (1) and (2). (1) A polyester polyol resin obtained by condensation reaction of a dibasic acid alone or a mixture of two or more thereof with a polyol alone or a mixture of two or more thereof. (2) A polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone using a polyol.

[0158] Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.

[0159] Examples of the polyol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerin, pentaerythritol, 2-methylolpropanediol, and ethoxylated trimethylolpropane.

[0160] [Epoxy resin]

[0161] Examples of the epoxy resin include novolac epoxy resins, β-methylepichlorohydrin epoxy resins, cyclic oxirane epoxy resins, glycidyl ether epoxy resins, glycol ether epoxy resins, epoxy aliphatic unsaturated compounds, epoxidized fatty acid esters, ester-type polycarboxylic acids, aminoglycidyl epoxy resins, halogenated epoxy resins, resorcinol epoxy resins, and epoxy resins modified with amino compounds, polyamide compounds, and the like.

[0162] [Fluorinated polyols]

[0163] Examples of the fluorine-containing polyol include copolymers of fluoroolefins, cyclohexyl vinyl ether, hydroxyalkyl vinyl ether, monocarboxylic acid vinyl esters, and the like disclosed in Reference 1 (Japanese Patent Application Laid-Open No. 57-34107) and Reference 2 (Japanese Patent Application Laid-Open No. 61-275311).

[0164] [Acrylic polymer]

[0165] The acrylic polymer contains one or more polymerizable (meth)acrylic monomer units having a crosslinkable functional group. The crosslinkable functional group preferably contains a hydroxyl group, a carboxyl group, or an epoxy group, and more preferably contains a hydroxyl group.

[0166] The acrylic polymer may contain one crosslinking functional group alone or two or more different crosslinking functional groups in combination. That is, the acrylic polymer may be obtained by polymerizing one polymerizable (meth) acrylic monomer having a crosslinking functional group alone or by copolymerizing two or more polymerizable (meth) acrylic monomers having different crosslinking functional groups in combination.

[0167] The acrylic polymer may contain one or more polymerizable acrylic monomer units not having a crosslinkable functional group in addition to the polymerizable (meth)acrylic monomer units having a crosslinkable functional group.

[0168] That is, the acrylic polymer can be obtained by polymerizing one or more polymerizable (meth)acrylic monomers having a crosslinkable functional group, or can be obtained by copolymerizing one or more polymerizable (meth)acrylic monomers having a crosslinkable functional group and one or more polymerizable (meth)acrylic monomers not having a crosslinkable functional group.

[0169] Examples of the aforementioned polymerizable (meth)acrylic monomers having a crosslinkable functional group include the monomers shown in (i) to (v) below. These may be used alone or in combination of two or more. (i) Acrylic esters having a hydroxyl group, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 4-hydroxybutyl acrylate, and 6-hydroxyhexyl acrylate. (ii) Methacrylic esters having a hydroxyl group, such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 2-hydroxybutyl methacrylate, 4-hydroxybutyl methacrylate, and 6-hydroxyhexyl methacrylate. (iii) (Meth)acrylic esters having a polyhydric hydroxyl group, such as glycerol monoacrylate or methacrylate, trimethylolpropane monoacrylate or methacrylate. (iv) Unsaturated carboxylic acids, such as acrylic acid, methacrylic acid, maleic acid, and itaconic acid. (v) A polymerizable monomer having an epoxy group, such as glycidyl methacrylate, 1,2-epoxy-4-vinylcyclohexane, allyl glycidyl ether, and 4-hydroxybutyl acrylate glycidyl ether.

[0170] As the aforementioned polymerizable (meth)acrylic monomers having no crosslinking functional group, for example, the monomers shown in (i) to (iii) below can be cited. These may be used alone or in combination of two or more. (i) Methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, (meth)acrylates such as esters, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate), tridecyl (meth)acrylate, tetradecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, nonadecyl (meth)acrylate, eicosyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, etc. (ii) unsaturated amides such as (meth)acrylamide, N-methylol acrylamide, diacetone acrylamide, dimethylaminopropyl acrylamide, etc. (iii) styrene, vinyl toluene, vinyl acetate, (meth)acrylonitrile, N-vinyl pyrrolidone, N-vinyl caprolactam, acryloyl morpholine, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate.

[0171] As other monomers copolymerizable with the polymerizable (meth)acrylic monomer having a crosslinkable functional group, polymerizable ultraviolet stabilizing monomers disclosed in JP-A-1-261409 (reference 3) and JP-A-3-006273 (reference 4) can be used.

[0172] Specific examples of the polymerizable UV-stable monomer include 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonyl-4-crotonyloxy-2,2,6,6-tetramethylpiperidine, and 2-hydroxy-4-(3-methacryloyloxy-2-hydroxypropoxy)benzophenone.

[0173] Among them, the acrylic polymer preferably contains one or more acrylic acid ester units having an alkyl group having 1 to 20 carbon atoms at the end of the ester group.

[0174] The acrylic acid ester unit having an alkyl group having 1 to 20 carbon atoms at the end of the ester group may or may not contain a crosslinkable functional group.

[0175] The number of carbon atoms in the alkyl group of the crosslinkable functional group-containing acrylate unit is 1 or more and 20 or less, preferably 1 or more and 18 or less, and more preferably 2 or more and 18 or less.

[0176] On the other hand, the carbon number of the alkyl group of the acrylate unit not containing a crosslinkable functional group is 1 to 20, preferably 1 to 18, more preferably 2 to 18, and further preferably 4 to 18.

[0177] For example, the acrylic polymer can be obtained by subjecting the above-mentioned monomer components to solution polymerization in the presence of a known radical polymerization initiator such as a peroxide or an azo compound, and diluting the mixture with an organic solvent or the like as necessary.

[0178] When obtaining an acrylic polymer of a water-based matrix, it can be produced by a known method such as a method of subjecting an olefinic unsaturated compound to solution polymerization and converting it to an aqueous layer, emulsion polymerization, etc. In this case, the acidic part of a carboxylic acid-containing monomer such as acrylic acid and methacrylic acid, a sulfonic acid-containing monomer, etc., can be neutralized with amines or ammonia to impart water solubility or water dispersibility.

[0179] [Isocyanate / Hydroxyl]

[0180] The molar ratio of isocyanate groups in the polyisocyanate composition 1 contained in the resin composition of the present embodiment to hydroxyl groups in the polyol (isocyanate group / hydroxyl group molar ratio) can be determined according to the physical properties required for the resin film, and is usually 0.01 to 22.5.

[0181] <Other ingredients>

[0182] The resin composition of the present embodiment may further contain other additives.

[0183] Examples of other additives include curing agents other than the polyisocyanate composition 1 that can react with the polyol, curing catalysts, solvents, pigments (extender pigments, coloring pigments, metallic pigments, etc.), tackifying resins, photopolymerization initiators, ultraviolet absorbers, light stabilizers, free radical stabilizers, anti-yellowing agents that suppress coloration during the sintering process, coating surface regulators, flow regulators, pigment dispersants, defoamers, thickeners, and film-forming aids.

[0184] Examples of the curing agent include melamine resins, urea resins, epoxy group-containing compounds or resins, carboxyl group-containing compounds or resins, acid anhydrides, alkoxysilane-containing compounds or resins, and hydrazide compounds.

[0185] The curing catalyst may be a basic compound or a Lewis acid compound.

[0186] Examples of the basic compound include metal hydroxides, metal alkoxides, metal carboxylates, metal acetylacetonates, hydroxides of onium salts, onium carboxylates, halides of onium salts, metal salts of active methylene compounds, onium salts of active methylene compounds, aminosilanes, amines, phosphines, etc. As the onium salt, an ammonium salt, a phosphonium salt or a sulfonium salt is preferred.

[0187] Examples of the Lewis acidic compound include organic tin compounds, organic zinc compounds, organic titanium compounds, and organic zirconium compounds.

[0188] Examples of the solvent include 1-methylpyrrolidone, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether (DPDM), propylene glycol dimethyl ether, methyl ethyl ketone, propylene glycol monomethyl ether, 1-methyl-2-nitropropene, 1-methyl-1-nitropropene, 1-methyl-2-nitropropene, 1-methyl-2-nitropropene, 1-methyl-2-nitropropene, 1-methyl-2-nitropropene Ketone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, ethanol, methanol, isopropanol, 1-propanol, isobutyl alcohol, 1-butanol, tert-butyl alcohol, 2-ethylhexanol, cyclohexanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, ethyl acetate, isopropyl acetate, butyl acetate, toluene, xylene, pentane, isopentane, hexane, isohexane, cyclohexane, solvent naphtha, mineral spirits, etc. These solvents can be used alone or in combination of two or more.

[0189] In addition, as pigments (extender pigments, coloring pigments, metallic pigments, etc.), ultraviolet absorbers, light stabilizers, free radical stabilizers, yellowing inhibitors for suppressing coloration during the sintering process, coating surface regulators, flow regulators, pigment dispersants, defoamers, thickeners and film-forming aids, known substances can be appropriately selected and used.

[0190] <Method for producing adhesive composition>

[0191] The adhesive composition can be produced by a conventionally known method, for example, a melt kneading method using a common mixer such as a Banbury mixer, a single screw extruder, a twin screw extruder, a co-kneader, or a multi-screw extruder; a method in which each component is dissolved or dispersed and mixed, and then applied to a substrate film using a coater, and then the solvent is removed by heating.

[0192] In order to seek the effects of lightness, flexibility and adhesion improvement, the adhesive composition of the present embodiment can be foamed. As the foaming method, there are chemical methods, physical methods, and the use of heat-expandable microspheres. Bubbles can be distributed inside the material by adding chemical foaming agents such as inorganic foaming agents or organic foaming agents, physical foaming agents, etc., or adding heat-expandable microspheres, etc.

[0193] Furthermore, by adding a hollow filler (expanded balls), it is also possible to achieve weight reduction, flexibility, and improved adhesion.

[0194] The adhesive composition of the present embodiment may be added with a tackifying resin to adjust the adhesive force and cohesive force. Examples of the tackifying resin include rosin-based tackifying resins, terpene-based tackifying resins, petroleum-based tackifying resins, and styrene-based tackifying resins. These tackifying resins may be used alone or in combination of two or more. In addition, the softening point of the tackifying resin is preferably above 90° C. and below 160° C.

[0195] Adhesive Sheet

[0196] The pressure-sensitive adhesive sheet of the present embodiment includes a substrate and a pressure-sensitive adhesive layer located on the substrate.

[0197] The adhesive layer includes a cured product of the above-mentioned adhesive composition.

[0198] In the pressure-sensitive adhesive sheet of the present embodiment, the pressure-sensitive adhesive layer is excellent in pressure-sensitive adhesiveness, curability, and transparency.

[0199] The substrate is not particularly limited, and examples thereof include papers such as high-quality paper, coated paper, cast-coated paper, thermal paper, and inkjet paper; fabrics such as woven fabrics and nonwoven fabrics; resin films such as polyvinyl chloride, synthetic paper, polyethylene terephthalate (PET), polypropylene, polyethylene, cellulose triacetate, cellulose diacetate, polystyrene, polycarbonate, nylon, polyvinyl alcohol, ethylene-vinyl acetate copolymer, and polyimide; porous resin films such as porous polypropylene films; vapor-deposited films obtained by vapor-depositing metals such as aluminum on PET, polyolefins, etc.; metal foils, etc. The substrate may also be a substrate on which a release treatment has been applied to the surface.

[0200] In the adhesive sheet of this embodiment, the thickness of the adhesive layer can be appropriately determined according to the application, and is preferably 1 μm to 1000 μm, more preferably 5 μm to 900 μm, further preferably 7 μm to 800 μm, and particularly preferably 9 μm to 700 μm.

[0201] The pressure-sensitive adhesive sheet of the present embodiment can be produced, for example, by applying the pressure-sensitive adhesive composition on a substrate, drying it as necessary, and then curing it.

[0202] As a method for applying the adhesive composition to the substrate, for example, a method of applying using an applicator, a roll coater, a knife coater, a gravure coater, etc. can be cited. In the case of drying after the above-mentioned coating, for example, a heating drying method can be cited, in which the obtained laminate is loaded into a dryer, etc. and dried at a temperature of 50° C. to 150° C. for 1 minute to 30 minutes. Alternatively, as other drying methods, for example, natural drying, hot air drying, infrared drying, etc. can be cited.

[0203] The heating temperature during curing may be 70° C. or higher and 150° C. or lower, 75° C. or higher and 145° C. or lower, or 80° C. or higher and 140° C. or lower.

[0204] Regarding the adhesive sheet of the present embodiment, the adhesive sheet having a 50 μm thick adhesive layer is stored at 23° C. and 50% RH for 7 days, then wrapped with a mesh sheet, immersed in ethyl acetate at 23° C. for 1 week, and dried at 120° C. for 2 hours, and the gel fraction calculated is preferably 20% by mass or more and 99% by mass or less, more preferably 25% by mass or more and 99% by mass or less, further preferably 30% by mass or more and 99% by mass or less, particularly preferably 35% by mass or more and 99% by mass or less, and most preferably 40% by mass or more and 99% by mass or less. The 50 μm thick adhesive layer is formed by applying the above-mentioned adhesive composition on a 38 μm thick polyethylene terephthalate film subjected to a peeling treatment, and drying at 130° C. for 3 minutes to cure it. By making the gel fraction equal to or greater than the above lower limit, the curability is more excellent.

[0205] The gel fraction referred to herein is the mass percentage of the pressure-sensitive adhesive sheet obtained by immersing in ethyl acetate and then drying relative to the mass of the pressure-sensitive adhesive sheet before immersing in ethyl acetate.

[0206] Regarding the adhesive sheet of the present embodiment, a 20 mm wide and 100 mm long adhesive sheet having an adhesive layer with a thickness of 50 μm is stored at 23° C. and 50% RH for 7 days, and then a SUS304BA steel plate is used as an adherend, and a 2 kg roller is used for pressure bonding by reciprocating once, and after aging at 23° C. for 30 minutes, the 180-degree peeling adhesive strength measured at a speed of 300 mm / min at 23° C. is preferably 0.05 N / 20 mm or more and 55 N / 20 mm or less, and more preferably 0.07 N / 20mm or more and 45N / 20mm or less, more preferably 0.1N / 20mm or more and 38N / 20mm or less, particularly preferably 0.12N / 20mm or more and 36N / 20mm or less, and most preferably 0.15N / 20mm or more and 33N / 20mm or less, wherein the adhesive layer having a thickness of 50μm is formed by applying the adhesive composition on a polyethylene terephthalate film having a thickness of 25μm and drying and curing it at 130°C for 3 minutes. By making the 180 degree peeling adhesive strength be above the above lower limit, the adhesiveness is more excellent.

[0207] Regarding the adhesive sheet of this embodiment, the adhesive layer of 50 μm thick formed by applying the above-mentioned adhesive composition on a polyethylene terephthalate film with a thickness of 38 μm and drying it at 130°C for 3 minutes to solidify it is peeled off from the above-mentioned polyethylene terephthalate film with a thickness of 38 μm, and then attached to a glass with a haze value of 0.1%. The haze value of the adhesive sheet obtained by measuring it with a haze meter is preferably 0.01% or more and 2% or less, more preferably 0.01% or more and 1.8% or less, further preferably 0.01% or more and 1.5% or less, particularly preferably 0.01% or more and 1.0% or less, and most preferably 0.01% or more and 0.8% or less. By making the haze value below the above-mentioned upper limit value, the transparency is more excellent.

[0208] 《Polyisocyanate composition 2》

[0209] The polyisocyanate composition 2 of the present embodiment is derived from diisocyanate, polycaprolactone polyol (A2) and polyether polyol (B2). That is, the polyisocyanate composition 2 of the present embodiment is a reaction product of diisocyanate, polycaprolactone polyol (A2) and polyether polyol (B2), and includes polyisocyanate modified by polycaprolactone polyol (A2) and polyether polyol (B2). The diisocyanate is at least one selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

[0210] The polyisocyanate composition 2 of the present embodiment contains 20 parts by mass or more of polypropylene glycol based on 100 parts by mass of the polyether polyol (B2).

[0211] The polyisocyanate composition 2 of this embodiment uses two different polyols as described above and contains polypropylene glycol as the polyether polyol (B2), thereby showing higher flexibility than before. Specifically, it has good compatibility with the main agent in a low temperature environment of about -10°C, and can obtain a coating film with excellent flexibility at a low temperature of about -10°C and a room temperature of about 23°C.

[0212] Next, the details of each constituent component of the polyisocyanate composition 2 of the present embodiment will be described below.

[0213] <Polyisocyanate>

[0214] The polyisocyanate composition 2 of the present embodiment may be a polyisocyanate having structural units derived from each of diisocyanate, polycaprolactone polyol (A2) and polyether polyol (B2) in one molecule, or may be a mixture of polyisocyanates having structural units derived from at least one selected from the group consisting of diisocyanate, polycaprolactone polyol (A2) and polyether polyol (B2) in one molecule.

[0215] The polyisocyanate may have at least one structure selected from the group consisting of an allophanate structure, a uretdione structure, an iminooxadiazinedione structure, an isocyanurate structure, a urea structure, a carbamate structure, and a biuret structure. Among them, it is preferred to have at least one structure selected from the group consisting of a carbamate structure, an allophanate structure, a biuret structure, a urea structure, and an isocyanurate group.

[0216] [Diisocyanate]

[0217] The diisocyanate is at least one selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates.

[0218] The aliphatic diisocyanate is not limited to the following, and examples thereof include 1,4-diisocyanatobutane, 1,5-diisocyanatopentane, (2,6-diisocyanato)ethylhexanoate, 1,6-diisocyanatohexane (hereinafter sometimes referred to as "HDI"), 1,9-diisocyanatononane, 1,12-diisocyanatododecane, 2,2,4- or 2,4,4-trimethyl-1,6-diisocyanatohexane, etc. These aliphatic diisocyanates may be used alone or in combination of two or more.

[0219] Examples of the alicyclic diisocyanate include, but are not limited to, 1,3- or 1,4-bis(isocyanatomethyl)cyclohexane (hereinafter sometimes referred to as "hydrogenated XDI"), 1,3- or 1,4-diisocyanatocyclohexane, 3,5,5-trimethyl1-isocyanato-3-(isocyanatomethyl)cyclohexane (hereinafter sometimes referred to as "IPDI"), 4-4'-diisocyanato-dicyclohexylmethane (hereinafter sometimes referred to as "hydrogenated MDI"), 2,5- or 2,6-diisocyanatomethylnorbornane, etc. These alicyclic diisocyanates may be used alone or in combination of two or more.

[0220] These aliphatic diisocyanates and alicyclic diisocyanates may be used alone or in combination of two or more.

[0221] Among them, as the diisocyanate, HDI, IPDI, hydrogenated XDI or hydrogenated MDI is preferred, HDI or IPDI is more preferred, and HDI is further preferred.

[0222] In the production of polyisocyanate, in addition to the above-mentioned diisocyanate, isocyanate monomers as shown below may be used.

[0223] (1) Aromatic diisocyanates such as diphenylmethane-4,4'-diisocyanate (MDI), 1,5-naphthalene diisocyanate, toluene diisocyanate (TDI), xylylene diisocyanate, and m-tetramethylxylylene diisocyanate (TMXDI).

[0224] (2) Triisocyanates such as 4-isocyanatemethyl-1,8-octamethylene diisocyanate (hereinafter sometimes referred to as "NTI"), 1,3,6-hexamethylene triisocyanate (hereinafter sometimes referred to as "HTI"), bis(2-isocyanatoethyl) 2-isocyanatoglutarate (hereinafter referred to as "GTI"), and lysine triisocyanate (hereinafter sometimes referred to as "LTI").

[0225] <Polycaprolactone polyol (A2)>

[0226] The polycaprolactone polyol is not particularly limited, and specifically can be obtained by ring-opening polymerization of ε-caprolactone in the presence of a catalyst using a divalent or higher alcohol, preferably a trivalent alcohol, as an initiator. Such an initiator is not particularly limited, and specifically, divalent alcohols such as ethylene glycol, propylene glycol, 1,3-butanediol, and neopentyl glycol; trivalent alcohols such as trimethylolpropane and glycerol can be used. From the viewpoint of obtaining a low-viscosity polyisocyanate, a polycaprolactone polyol having a branched chain is preferred. Such a polycaprolactone polyol can be obtained by using a trivalent or higher alcohol as an initiator.

[0227] The catalyst is not particularly limited, and specific examples thereof include organic titanium compounds such as tetrabutyl titanate, tetrapropyl titanate, and tetraethyl titanate; and tin compounds such as tin octylate, dibutyltin oxide, dibutyltin laurate, stannous chloride, and stannous bromide.

[0228] The ring-opening polymerization of ε-caprolactone is not particularly limited, and can be specifically carried out as follows: under a nitrogen atmosphere, the molar ratio of ε-caprolactone to the above-mentioned initiator is set in a manner to obtain a desired molecular weight, and a catalyst is added in an amount of 0.1 mass ppm to 100 mass ppm relative to ε-caprolactone, and the reaction is carried out at a temperature of 150° C. to 200° C. for 4 hours to 10 hours.

[0229] The polyisocyanate forms a urethane group by reaction between the hydroxyl group of the polycaprolactone polyol (A2) and the isocyanate group of the diisocyanate.

[0230] The average number of hydroxyl functional groups of the polycaprolactone polyol (A2) is preferably 2.0 or more and 8.0 or less, more preferably 2 or more and 6 or less, further preferably 2 or more and 5 or less, and particularly preferably 3. It should be noted that the average number of hydroxyl functional groups of the polycaprolactone polyol (A2) referred to here is the number of hydroxyl groups present in one molecule of the polycaprolactone polyol (A2).

[0231] The number average molecular weight of the polycaprolactone polyol (A2) is preferably 500 or more and 1500 or less, more preferably 600 or more and 1400 or less, further preferably 700 or more and 1300 or less, particularly preferably 850 or more and 1250 or less.

[0232] When the number average molecular weight of the polycaprolactone polyol (A2) is within the above range, the resulting coating film has better flexibility at low and room temperatures. The number average molecular weight Mn of the polycaprolactone polyol (A2) is, for example, a polystyrene-standard number average molecular weight measured by gel permeation chromatography (GPC).

[0233] Examples of commercially available polycaprolactone polyols include "PLACCEL 305" (number average molecular weight 550), "PLACCEL 308" (number average molecular weight 850), "PLACCEL 309" (number average molecular weight 900), "PLACCEL 312" (number average molecular weight 1250), "PLACCEL 205" (number average molecular weight 530), and "PLACCEL 210" (number average molecular weight 1000) manufactured by Daicel Corporation; and "POLYLITE OD-X-2735" (number average molecular weight 500), "POLYLITE OD-X-2586" (number average molecular weight 850), and "POLYLITE OD-X-2588" (number average molecular weight 1250) manufactured by DIC Corporation.

[0234] <Polyether polyol (B2)>

[0235] The polyether polyol (B2) comprises polypropylene glycol (PPG, also called polyoxypropylene polyol).

[0236] In the polyisocyanate composition 2 of the present embodiment, the PPG content is 20 parts by mass or more, preferably 40 parts by mass or more, more preferably 50 parts by mass or more, further preferably 55 parts by mass or more, particularly preferably 60 parts by mass, and most preferably 100 parts by mass relative to 100 parts by mass of the polyether polyol (B2). By making the PPG content greater than the above lower limit, the compatibility with the main agent in a low temperature environment can be improved.

[0237] The polypropylene glycol is not particularly limited, and specific examples thereof include polyoxypropylene glycol or triol; so-called Pluronic (registered trademark) type polyoxypropylene glycol or triol in which ethylene oxide is addition-polymerized at the end of the polyoxypropylene glycol or triol; polyoxypropylene polyoxyethylene polymer glycol or triol, etc. Among them, the aforementioned Pluronic (registered trademark) type polyoxypropylene glycol or triol is preferred from the viewpoint of excellent reactivity with diisocyanate.

[0238] As a method for producing polypropylene glycol, a method of adding propylene oxide, ethylene oxide used as needed, etc. to an initiator and a catalyst alone or in a mixture can be cited. As an initiator, there is no particular limitation, specifically, polyols, polyphenols, polyamines, alkanolamines, or mixtures thereof can be cited, more specifically, dihydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, neopentyl glycol, 1,4-butanediol, 1,6-hexanediol, and bisphenol A can be cited; trihydric alcohols such as glycerol and trimethylolpropane; diamines such as ethylenediamine; and mixtures thereof. In addition, as a catalyst, there is no particular limitation, specifically, hydroxides of lithium, sodium, potassium, etc. can be cited; strong alkaline catalysts such as alkoxides and alkylamines; metal porphyrins, complex metal cyanide complexes, complexes of metals and chelating agents with 3 or more ligands, complex metal complexes such as hexacyanocobaltate complexes. In addition, a method of obtaining polypropylene glycol by dehydration condensation of a polyol can be cited, etc.

[0239] Examples of commercially available polypropylene glycols include "EXCENOL 510" (terminal EO-added polyoxypropylene diol, number average molecular weight 4000), "EXCENOL 840" (terminal EO-added polyoxypropylene triol, number average molecular weight 6500), "EXCENOL 1020" (terminal EO-added polyoxypropylene diol, number average molecular weight 1000), and "EXCENOL 2020" (terminal EO-added polyoxypropylene diol, number average molecular weight 2000) manufactured by Asahi Glass Co., Ltd.

[0240] The polyether polyol (B2) may contain other polyether polyols in addition to polypropylene glycol.

[0241] There are no particular limitations on other polyether polyols, and examples thereof include: polyether polyols obtained by adding alkylene oxide alone or a mixture thereof to polyols alone or a mixture thereof using an alkali metal hydroxide or a strong alkaline catalyst; polyether polyols obtained by reacting alkylene oxide with a polyamine compound; and so-called polymer polyols obtained by polymerizing acrylamide or the like using the above-mentioned polyether as a medium.

[0242] Examples of the alkali metal include lithium, sodium, potassium, etc. Examples of the strong basic catalyst include alkoxides, alkylamines, and the like.

[0243] The polyol is not particularly limited, and examples thereof include at least one polyol selected from the group consisting of ethylene glycol, propylene glycol, diethylene glycol, neopentyl glycol, trimethylolpropane, and glycerin.

[0244] Examples of the alkylene oxide include ethylene oxide, butylene oxide, cyclohexyl oxide, and styrene oxide.

[0245] Examples of the polyamine compound include ethylenediamines and the like.

[0246] Among them, as other polyether polyols, polytetramethylene ether glycol (PTMG, also referred to as polyoxytetramethylene polyol) is preferred.

[0247] Polytetramethylene ether glycol can be manufactured by cationic polymerization of tetrahydrofuran using a catalyst, etc. There is no particular limitation on the catalyst used, and specifically, acetic anhydride-perchloric acid, fluorosulfonic acid or fuming sulfuric acid can be used. For example, the manufacture of polyoxytetramethylene glycol is not particularly limited, and specifically, it can be usually carried out by adding about 1% by mass or more and 30% by mass or less of fluorosulfonic acid to the raw material tetrahydrofuran, and reacting at a temperature of 5°C or more and 65°C or less for more than a few minutes and less than tens of hours. In addition, similar to the above-mentioned method for manufacturing polypropylene glycol, it can be obtained by using a polyol as an initiator and using a strong basic catalyst to perform butylene oxide addition. In addition, the molecular weight of the generated polytetramethylene ether glycol can be adjusted by changing the polymerization temperature, polymerization time, catalyst dosage, etc.

[0248] Examples of commercially available polytetramethylene ether glycol include trade names “PTMG1000” (number average molecular weight 1000), “PTMG2000” (number average molecular weight 2000), “PTMG3000” (number average molecular weight 2900), and “PTMG4000” (number average molecular weight 4000) manufactured by Mitsubishi Chemical Corporation.

[0249] In the polyether polyol (B2), the mass ratio of polytetramethylene ether glycol to polypropylene glycol (mass ratio of PTMG / PPG) is preferably 0 / 100 or more and 80 / 20 or less, more preferably 0 / 100 or more and 60 / 40 or less, further preferably 0 / 100 or more and 50 / 50 or less, and particularly preferably 0 / 100 or more and 45 / 55 or less. When the mass ratio of PTMG / PPG is within the above range, the compatibility with the main agent in a low temperature environment can be further improved.

[0250] The number average molecular weight of the polyether polyol (B2) is preferably 1,000 or more and 7,000 or less, more preferably 2,000 or more and 7,000 or less, further preferably 3,000 or more and 6,700 or less, particularly preferably 4,000 or more and 6,500 or less.

[0251] By making the number average molecular weight of the polyether polyol (B2) within the above range, the softness of the obtained coating film at low temperature and room temperature is more excellent. The number average molecular weight Mn of the polyether polyol (B2) is, for example, the number average molecular weight based on the polystyrene standard measured by GPC. In addition, when two or more polyether polyols (B2) are mixed and used, the number average molecular weight of the mixture is calculated.

[0252] In the polyisocyanate composition 2 of the present embodiment, the mass ratio of the polycaprolactone polyol (A2) to the polyether polyol (B2) (mass ratio of (A2) / (B2)) is preferably 10 / 90 or more and 90 / 10 or less, more preferably 15 / 85 or more and 85 / 15 or less, and further preferably 18 / 82 or more and 83 / 17 or less.

[0253] By making the mass ratio of (A2) / (B2) equal to or greater than the above lower limit, the compatibility with the main agent in a low temperature environment can be improved. On the other hand, by making it equal to or less than the above upper limit, a coating film having better flexibility at low and normal temperatures can be obtained.

[0254] The mass ratio of (A2) / (B2) can be calculated from, for example, the blending amounts of the respective polyols.

[0255] <Method for producing polyisocyanate composition 2>

[0256] The polyisocyanate is obtained by reacting the above-mentioned diisocyanate, polycaprolactone polyol (A2) and polyether polyol (B2). Hereinafter, the polycaprolactone polyol (A2) and the polyether polyol (B2) may be collectively referred to as polyol.

[0257] The polycaprolactone polyol (A2) and the polyether polyol (B2) may be used alone or in a mixture. When used in a mixture, they may be mixed before reacting with diisocyanate, or each polyol may be reacted with diisocyanate alone to form a polyisocyanate and then mixed.

[0258] That is, as a method for producing the polyisocyanate composition 2, for example, there can be cited a method of obtaining the polyisocyanate composition 2 by simultaneously reacting a diisocyanate, a polycaprolactone polyol (A2) and a polyether polyol (B2); a method of obtaining the polyisocyanate composition 2 by mixing a product obtained by reacting a diisocyanate with a polycaprolactone polyol (A2) and a product obtained by reacting a diisocyanate with a polyether polyol (B2); a method of obtaining the polyisocyanate composition 2 by reacting a diisocyanate with a polycaprolactone polyol (A2) or a polyether polyol (B2), and then further reacting the remaining polyol, etc.

[0259] The amounts of the polycaprolactone polyol (A2) and the polyether polyol (B2) to be added are preferably such that the mass ratio of the polycaprolactone polyol (A2) to the polyether polyol (B2) is within the above range.

[0260] The reaction of the polyol and the diisocyanate is carried out as described below. The reaction temperature is usually above room temperature (about 23°C) and below 200°C, preferably above 80°C and below 120°C. When the reaction temperature is above the above lower limit, the reaction time is further shortened. On the other hand, when it is below the above upper limit, the viscosity increase of the polyisocyanate caused by undesirable side reactions can be further avoided, and the coloring of the generated polyisocyanate can also be further avoided.

[0261] The reaction may be carried out without a solvent or using any solvent inactive to isocyanate groups. In addition, a known catalyst may be used to promote the reaction between the isocyanate groups and the hydroxyl groups as required.

[0262] During the reaction, the molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polycaprolactone polyol (A2) and the polyether polyol (B2) (mol ratio of hydroxyl group / isocyanate group) is preferably 2 or more and 10 or less, more preferably 3 or more and 9 or less, and even more preferably 4 or more and 8 or less. By making the molar ratio of hydroxyl group / isocyanate group equal to or more than the above lower limit, the viscosity increase of the polyisocyanate caused by the successive addition reaction between the diisocyanate and the polyol can be further avoided. On the other hand, by being equal to or less than the above upper limit, the productivity becomes better.

[0263] When the reaction is finished, the unreacted diisocyanate in the reaction mixture can be recovered by a known method such as a thin film distillation apparatus, solvent extraction, etc. The less the amount of unreacted diisocyanate remains, the more odor, toxicity, irritation, etc. caused by the diisocyanate during thermal curing can be avoided.

[0264] <Physical Properties of Polyisocyanate Composition 2>

[0265] The isocyanate group content (NCO group content) of the polyisocyanate composition 2 of the present embodiment is preferably 3% by mass or more and 8% by mass or less, more preferably 3.1% by mass or more and 7.5% by mass or less, and further preferably 3.3% by mass or more and 7.3% by mass or less, relative to the total mass of the polyisocyanate composition 2, in a state substantially free of solvent and diisocyanate.

[0266] The NCO group content can be determined, for example, by reacting the isocyanate groups of the polyisocyanate composition 2 with an excess of amine (such as dibutylamine) and back-titrating the excess amine with an acid such as hydrochloric acid.

[0267] 《Resin composition》

[0268] The resin composition of the present embodiment contains the polyisocyanate composition 2 as a curing agent component and a polyol as a main agent component.

[0269] The resin composition of the present embodiment contains the polyisocyanate composition 2 as a curing agent component, thereby obtaining a coating film having excellent flexibility at a low temperature of about -10°C and a normal temperature of about 23°C.

[0270] The resin composition of this embodiment can be used, for example, for architectural coatings, automotive coatings, automotive repair coatings, plastic coatings, adhesives, bonding agents, building materials, household water-based coatings, other coating agents, sealants, inks, molding materials, elastomers, foams, plastic raw materials, fiber treatment agents, and the like.

[0271] Among them, the resin composition of the present embodiment is preferably used as an adhesive composition from the viewpoint of excellent flexibility at low temperature and room temperature when formed into a coating film.

[0272] Next, the details of each constituent component contained in the resin composition of the present embodiment will be described below.

[0273] <Polyol>

[0274] Specific examples of the polyol include aliphatic hydrocarbon polyols, polyether polyols, polyester polyols, epoxy resins, fluorine-containing polyols, and acrylic polyols.

[0275] Among them, as the polyol, acrylic polyol is preferred.

[0276] [Aliphatic hydrocarbon polyol]

[0277] Examples of the aliphatic hydrocarbon polyol include terminal hydroxylated polybutadiene and hydrogenated products thereof.

[0278] [Polyether polyol]

[0279] Examples of the polyether polyol include polyether polyols obtained by any of the following methods (1) to (3).

[0280] (1) A polyether polyol or polytetramethylene ether glycol obtained by adding an alkylene oxide alone or in a mixture to a polyol alone or in a mixture thereof. (2) A polyether polyol obtained by reacting a polyfunctional compound with an alkylene oxide.

[0281] (3) So-called polymer polyols obtained by polymerizing acrylamide or the like using the polyether polyol obtained in (1) or (2) as a medium.

[0282] Examples of the polyol include glycerin and propylene glycol.

[0283] Examples of the alkylene oxide include ethylene oxide and propylene oxide.

[0284] Examples of the polyfunctional compound include ethylenediamine and ethanolamine.

[0285] [Polyester polyol]

[0286] Examples of the polyester polyol include any of the following (1) and (2).

[0287] (1) A polyester polyol resin obtained by a condensation reaction of a dibasic acid alone or a mixture of two or more thereof with a polyol alone or a mixture of two or more thereof.

[0288] (2) Polycaprolactone polyol obtained by ring-opening polymerization of ε-caprolactone using a polyol.

[0289] Examples of the dibasic acid include carboxylic acids such as succinic acid, adipic acid, dimer acid, maleic anhydride, phthalic anhydride, isophthalic acid, terephthalic acid, and 1,4-cyclohexanedicarboxylic acid.

[0290] Examples of the polyol include ethylene glycol, propylene glycol, diethylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, trimethylpentanediol, cyclohexanediol, trimethylolpropane, glycerin, pentaerythritol, 2-methylolpropanediol, and ethoxylated trimethylolpropane.

[0291] [Epoxy resin]

[0292] Examples of the epoxy resin include novolac epoxy resins, β-methylepichlorohydrin epoxy resins, cyclic oxirane epoxy resins, glycidyl ether epoxy resins, glycol ether epoxy resins, epoxy aliphatic unsaturated compounds, epoxidized fatty acid esters, ester-type polycarboxylic acids, aminoglycidyl epoxy resins, halogenated epoxy resins, resorcinol epoxy resins, and epoxy resins modified with amino compounds, polyamide compounds, and the like.

[0293] [Fluorinated polyols]

[0294] Examples of the fluorine-containing polyol include copolymers of fluoroolefins, cyclohexyl vinyl ether, hydroxyalkyl vinyl ether, monocarboxylic acid vinyl esters, and the like disclosed in Reference 1 (Japanese Patent Application Laid-Open No. 57-34107) and Reference 2 (Japanese Patent Application Laid-Open No. 61-275311).

[0295] [Acrylic polyol]

[0296] The acrylic polyol can be obtained, for example, by polymerizing a polymerizable monomer having one or more active hydrogen atoms in one molecule, or by copolymerizing a polymerizable monomer having one or more active hydrogen atoms in one molecule and, if necessary, other monomers copolymerizable with the polymerizable monomer.

[0297] Examples of the polymerizable monomer having one or more active hydrogen atoms in one molecule include the monomers shown in (i) to (iii) below. These may be used alone or in combination of two or more.

[0298] (i) Acrylates having active hydrogen, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, and 2-hydroxybutyl acrylate.

[0299] (ii) Methacrylates having active hydrogen, such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 2-hydroxybutyl methacrylate.

[0300] (iii) (meth)acrylates having a plurality of active hydrogen atoms, such as monoacrylate or monomethacrylate of glycerol and monoacrylate or monomethacrylate of trimethylolpropane.

[0301] Examples of the other monomers copolymerizable with the polymerizable monomer include the monomers (i) to (v) below. These may be used alone or in combination of two or more.

[0302] (i) Acrylates such as methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, and 2-ethylhexyl acrylate.

[0303] (ii) Methacrylates such as methyl methacrylate, ethyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-hexyl methacrylate, cyclohexyl methacrylate, lauryl methacrylate and glycidyl methacrylate.

[0304] (iii) Unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, etc. (iv) Unsaturated amides such as acrylamide, N-methylol acrylamide, diacetone acrylamide, etc.

[0305] (v) Styrene, vinyl toluene, vinyl acetate, acrylonitrile, etc.

[0306] In addition, acrylic polyols obtained by copolymerizing polymerizable ultraviolet stable monomers disclosed in Reference 3 (Japanese Patent Application Laid-Open No. 1-261409) and Reference 4 (Japanese Patent Application Laid-Open No. 3-006273) and the like can be mentioned.

[0307] Specific examples of the polymerizable UV-stable monomer include 4-(meth)acryloyloxy-2,2,6,6-tetramethylpiperidine, 4-(meth)acryloylamino-2,2,6,6-tetramethylpiperidine, 1-crotonyl-4-crotonyloxy-2,2,6,6-tetramethylpiperidine, and 2-hydroxy-4-(3-methacryloyloxy-2-hydroxypropoxy)benzophenone.

[0308] For example, the acrylic polyol can be obtained by subjecting the above-mentioned monomer components to solution polymerization in the presence of a known radical polymerization initiator such as a peroxide or an azo compound, and diluting the resulting mixture with an organic solvent or the like as necessary.

[0309] When obtaining an acrylic polyol having a water-based matrix, it can be produced by a known method such as a method of subjecting an olefinic unsaturated compound to solution polymerization and converting it to an aqueous layer, emulsion polymerization, etc. In this case, water solubility or water dispersibility can be imparted by neutralizing the acidic part of a carboxylic acid-containing monomer such as acrylic acid or methacrylic acid, or a sulfonic acid-containing monomer with amine or ammonia.

[0310] [Isocyanate / Hydroxyl]

[0311] The molar ratio of isocyanate groups in the polyisocyanate composition 2 contained in the resin composition of the present embodiment to hydroxyl groups in the polyol (isocyanate group / hydroxyl group molar ratio) can be determined according to the physical properties required for the resin film, and is usually 0.01 to 22.5.

[0312] <Other ingredients>

[0313] The resin composition of the present embodiment may further contain other additives.

[0314] Examples of other additives include curing agents other than the polyisocyanate composition 2 that can react with the polyol, curing catalysts, solvents, pigments (extender pigments, coloring pigments, metallic pigments, etc.), photopolymerization initiators, ultraviolet absorbers, light stabilizers, free radical stabilizers, anti-yellowing agents that suppress coloration during the sintering process, coating surface regulators, flow regulators, pigment dispersants, defoamers, thickeners, and film-forming aids.

[0315] Examples of the curing agent include melamine resins, urea resins, epoxy group-containing compounds or resins, carboxyl group-containing compounds or resins, acid anhydrides, alkoxysilane-containing compounds or resins, and hydrazide compounds.

[0316] The curing catalyst may be a basic compound or a Lewis acid compound.

[0317] Examples of the alkaline compound include metal hydroxides, metal alkoxides, metal carboxylates, metal acetylacetonates, hydroxides of onium salts, onium carboxylates, halides of onium salts, metal salts of active methylene compounds, onium salts of active methylene compounds, aminosilanes, amines, phosphines, etc. Examples of the onium salt include ammonium salts, phosphonium salts, or sulfonium salts. Examples of the Lewis acidic compound include organotin compounds, organozinc compounds, organotitanium compounds, and organozirconium compounds.

[0318] Examples of the solvent include 1-methylpyrrolidone, ethylene glycol monoethyl ether, diethylene glycol monoethyl ether, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, dipropylene glycol monomethyl ether, propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, dipropylene glycol dimethyl ether (DPDM), propylene glycol dimethyl ether, methyl ethyl ketone, propylene glycol monomethyl ether, 1-methyl-2-nitropropene, 1-methyl-1-nitropropene, 1-methyl-2-nitropropene, 1-methyl-2-nitropropene, 1-methyl-2-nitropropene, 1-methyl-2-nitropropene Ketone, methyl isobutyl ketone, propylene glycol monomethyl ether acetate, ethanol, methanol, isopropanol, 1-propanol, isobutyl alcohol, 1-butanol, tert-butyl alcohol, 2-ethylhexanol, cyclohexanol, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, 1,4-butanediol, 1,3-butanediol, ethyl acetate, isopropyl acetate, butyl acetate, toluene, xylene, pentane, isopentane, hexane, isohexane, cyclohexane, solvent naphtha, mineral spirits, etc. These solvents can be used alone or in combination of two or more.

[0319] In addition, as pigments (extender pigments, coloring pigments, metallic pigments, etc.), ultraviolet absorbers, light stabilizers, free radical stabilizers, yellowing inhibitors for suppressing coloration during the sintering process, coating surface regulators, flow regulators, pigment dispersants, defoamers, thickeners and film-forming aids, known substances can be appropriately selected and used.

[0320] <Method for producing resin composition>

[0321] The resin composition of the present embodiment can be produced by a conventionally known method.

[0322] When the resin composition of the present embodiment is an adhesive composition, for example, a melt kneading method using a common mixer such as a Banbury mixer, a single-screw extruder, a twin-screw extruder, a co-kneader, or a multi-screw extruder can be used; a method in which each component is dissolved or dispersed and mixed, and then applied to a substrate film using a coater, and then the solvent is removed by heating; etc.

[0323] In order to seek lightweight, soft, adhesion improvement effect, the resin composition of the present embodiment can be foamed. As the foaming method, there are chemical methods, physical methods, and thermal expansion type microspheres. Bubbles can be distributed inside the material by adding chemical foaming agents such as inorganic foaming agents or organic foaming agents or physical foaming agents, or adding thermal expansion type microspheres.

[0324] Furthermore, by adding a hollow filler (expanded spheres), it is also possible to achieve weight reduction, flexibility, and improved adhesion.

[0325] When the resin composition of the present embodiment is an adhesive composition, a tackifying resin may be added to adjust the adhesive force and cohesive force. As the tackifying resin, for example, rosin-based tackifying resins, terpene-based tackifying resins, petroleum-based tackifying resins, styrene-based tackifying resins, etc. may be cited. These tackifying resins may be used alone or in combination of two or more. In addition, the softening point of the tackifying resin is preferably above 90° C. and below 160° C.

[0326] Example

[0327] The present embodiment will be described in more detail below based on examples and comparative examples, but the present embodiment is not limited to the following examples at all.

[0328] <Test items>

[0329] About the polyisocyanate compositions produced in Examples and Comparative Examples, various physical properties were measured and evaluated by the methods shown below.

[0330] [Physical property 1] (isocyanate group content)

[0331] First, accurately weigh more than 2g and less than 3g (Wg) of the test sample in a flask. Then add 20mL of toluene to dissolve the test sample. Then add 20mL of a toluene solution of 2 equivalents of di-n-butylamine and mix, and leave at room temperature for 15 minutes. Then add 70mL of isopropanol and mix. Then titrate the liquid with an indicator using a 1 equivalent hydrochloric acid solution (factor F). The titration value obtained is set to V2mL. Then, the titration value obtained under the condition of no polyisocyanate sample is set to V1ml. Then calculate the isocyanate group content (NCO%) (mass %) of the polyisocyanate composition by the following formula.

[0332] Isocyanate group content (mass %) = (V1-V2) × F × 42 / (W × 1000) × 100

[0333] [Physical Properties 2] (Number Average Molecular Weight and Weight Average Molecular Weight)

[0334] The number average molecular weight and the weight average molecular weight are the number average molecular weight and the weight average molecular weight based on polystyrene measured by gel permeation chromatography (GPC) using the following apparatus.

[0335] (Measurement conditions)

[0336] Device: Made by Tosoh Corporation, HLC-802A

[0337] Column: Made by Tosoh Corporation, G1000HXL×1

[0338] G2000HXL×1

[0339] G3000HXL×1

[0340] Carrier: Tetrahydrofuran

[0341] Detection method: Differential refractometer

[0342] [Physical Property 3] (Average number of isocyanate functional groups)

[0343] The average number of isocyanate functional groups (average NCO number) of the polyisocyanate composition is calculated by the following formula: In the formula, "Mn" represents the number average molecular weight, and the value measured in the above "Physical Property 2" is used. "NCO%" is the value calculated in the above "Physical Property 1".

[0344] Average number of isocyanate functional groups = (Mn × NCO% × 0.01) / 42

[0345] [Physical Property 4] (Glass transition temperature Tg)

[0346] Regarding the glass transition temperature of acrylic polyol and cross-linkable functional group-containing polymer, the organic solvent and water in the acrylic polyol solution or the cross-linkable functional group-containing polymer solution are evaporated under reduced pressure and then vacuum dried. The obtained material is measured using a differential scanning calorimeter (DSC) measuring apparatus at a heating rate of 5°C / min, and the obtained value is used as the glass transition temperature.

[0347] [Preparation of Cured Film of Polyisocyanate Composition]

[0348] Each polyisocyanate composition was applied onto a release film using an applicator, stored at 23° C. and 65% humidity for 168 hours, and then heated at 50° C. for 24 hours to obtain a cured film having a thickness of 40 μm.

[0349] [Evaluation 1] (Flexibility of Cured Film)

[0350] The cured film was measured for Koenig hardness (times) at 23° C. using a Koenig hardness tester (Pendulum hardness tester manufactured by BYK Gardner). Films with a Koenig hardness of 60 times or less were evaluated as having low hardness and good flexibility.

[0351] [Production of coating film]

[0352] Each polyisocyanate composition, polyol and acrylic polyol for coating composition preparation were mixed to obtain a coating composition. Each obtained coating composition was applied to a release film with an applicator, cured at 90° C. for 30 minutes, and stored at 23° C. and 65% humidity for 168 hours to obtain a coating film.

[0353] [Evaluation 2] (Elongation and stress at 140% elongation)

[0354] For the obtained coating film, a test piece of 10 mm in width and 100 mm in length was placed in a tensile testing machine with a clamp distance of 20 mm, and a tensile test was performed at a speed of 20 mm / min to measure the elongation and the stress at an elongation of 140%. The elongation of 50% or more and the stress at an elongation of 140% of 28 MPa or less were evaluated as having good elongation and good stress at an elongation of 140%, respectively.

[0355] [Preparation of Adhesive Composition X]

[0356] To 100 parts by mass of the acrylic polymer OH1, 0.5 parts by mass of each polyisocyanate composition (1.0 parts by mass for the polyisocyanate compositions PA1-a5 and PA1-a11) and ethyl acetate were added to prepare an adhesive composition X having a solid content of 25% by mass.

[0357] [Preparation of Adhesive Composition Y]

[0358] To 100 parts by mass of the acrylic polymer OH2, 3 parts by mass of each polyisocyanate composition and ethyl acetate were added to prepare a pressure-sensitive adhesive composition Y having a solid content of 25% by mass.

[0359] [Preparation of PSA Sheet 1] (Preparation of PSA Sheet for 180-degree Peel Adhesive Strength Measurement)

[0360] Adhesive composition X or adhesive composition Y was applied to a 25 μm thick polyethylene terephthalate (PET) film using an applicator to a thickness of 50 μm after drying, and dried at 130° C. for 3 minutes. Thereafter, the film was stored at 23° C. and 50% RH for 7 days to obtain an adhesive sheet for 180 degree peeling adhesive strength measurement.

[0361] [Evaluation 3] (Adhesion and cohesion)

[0362] The adhesive sheet obtained in the above "Preparation of Adhesive Sheet 1" was used and a SUS304BA steel plate was used as an adherend. A 2 kg roller was moved back and forth once to press the test piece onto the steel plate. After aging at 23°C for 30 minutes, the 180 degree peeling adhesive strength was measured at a speed of 300 mm / min using a tensile tester. A value of 0.05 N / 20 mm or more was evaluated as good adhesiveness.

[0363] In addition, the adherends with no adhesive layer remaining after peeling were evaluated as having good cohesive force (in the table: ○). In addition, the adherends with a small amount of adhesive residue of less than 5% of the bonding area were evaluated as △, the adherends with adhesive residue of more than 5% and less than 20% were evaluated as △ ○, and the adherends with adhesive residue of more than 20% were evaluated as ×.

[0364] [Preparation of PSA Sheet 2] (Preparation of PSA Sheet for Gel Fraction Measurement)

[0365] PSA composition X or PSA composition Y was applied to a 38 μm thick release-treated PET film using an applicator to a thickness of 50 μm after drying, and dried at 130° C. for 3 minutes. Thereafter, the film was stored at 23° C. and 50% RH for 7 days to obtain a PSA sheet for gel fraction measurement.

[0366] [Evaluation 4] (Curing property)

[0367] The adhesive sheet obtained in the above "Preparation of Adhesive Sheet 2" was collected to a degree of 0.1 g or more and 0.2 g or less, wrapped with a mesh sheet, immersed in ethyl acetate for 1 week, and dried at 120°C for 2 hours. Then, the gel fraction (mass %) was calculated by the following formula. For those with a gel fraction of 20 mass % or more, the curing property was evaluated to be good.

[0368] (Gel fraction) = (mass of sample after drying) / (mass of sample before ethyl acetate addition) × 100

[0369] [Preparation of adhesive sheet 3] (Preparation of adhesive sheet for haze value measurement)

[0370] Adhesive composition X or adhesive composition Y is applied to a 38 μm thick release-treated polyethylene terephthalate film, dried at 130° C. for 3 minutes to cure, and the formed 50 μm thick adhesive layer is peeled off from the release-treated polyethylene terephthalate film and bonded to glass with a haze value of 0.1% to obtain an adhesive sheet for haze value measurement.

[0371] [Evaluation 5] (Transparency)

[0372] The haze of the PSA sheet obtained in the above "Preparation of PSA Sheet 3" was measured using a haze meter (HMG-2DP) manufactured by Suga Test Co., Ltd. A sheet with a haze value of 2% or less was evaluated as having good transparency.

[0373] [Preparation of resin composition]

[0374] Each polyisocyanate composition and acrylic polyol (manufactured by Allnex, trade name "Setalux1152") were mixed so that the molar ratio of isocyanate group to hydroxyl group was 1.0, and further diluted with butyl acetate so that the solid content was 50% by mass. Then, a tin catalyst (manufactured by Nitto Kasei Co., Ltd., trade name "NEOSTANN U-100") was further mixed in the diluted solution in an amount of 300 ppm by mass relative to the solid content to obtain each resin composition.

[0375] [Evaluation 6] (Compatibility with main agent)

[0376] Each resin composition just prepared was kept in an environment of -10°C for 5 days. The state of the coating liquid was visually observed and evaluated according to the following evaluation criteria.

[0377] (Evaluation Criteria)

[0378] ◎: Transparent and uniform

[0379] △: Partial turbidity

[0380] ×: The whole is turbid

[0381] [Production of coating film]

[0382] Each resin composition was applied to a polypropylene plate so as to have a film thickness of 30 μm, and dried by heating at 120° C. for 30 minutes, and then dried for 1 day in an environment of 23° C. and 50% humidity to prepare each coating film.

[0383] [Evaluation 7] (Low-temperature elongation at break)

[0384] The prepared coating film was cut into long strips to prepare test pieces. Then, the test pieces were installed in a tensile testing machine (Tensilon universal testing machine) in a 20 mm long and 10 mm wide manner, and the test was carried out at a test temperature of -10°C and a tensile speed of 20 mm / min to measure the elongation at break. The elongation at break was evaluated according to the following evaluation criteria.

[0385] (Evaluation Criteria)

[0386] ◎: Elongation at break is 150% or more

[0387] ○: Elongation at break is 100% or more and less than 150%

[0388] ×: Elongation at break is less than 100%

[0389] [Evaluation 8] (Low-temperature low-stress properties (stress at 20% elongation))

[0390] The prepared coating film was cut into long strips to prepare test pieces. Then, the test pieces were installed in a tensile testing machine (Tensilon universal testing machine) with a length of 20 mm and a width of 10 mm, and the test was carried out at a test temperature of -10°C and a tensile speed of 20 mm / min. The stress value at an elongation of 20% was evaluated according to the following evaluation criteria.

[0391] (Evaluation Criteria)

[0392] ◎: Less than 10MPa

[0393] ○: 10MPa or more and less than 30MPa

[0394] ×: 30MPa or more

[0395] [Evaluation 9] (Low stress at room temperature (stress at 75% elongation))

[0396] The prepared coating film was cut into long strips to prepare test pieces. Then, the test pieces were installed in a tensile testing machine (Tensilon universal testing machine) with a length of 20 mm and a width of 10 mm, and the test was carried out at a test temperature of 23°C and a tensile speed of 20 mm / min. The stress value at an elongation of 75% was evaluated according to the following evaluation criteria.

[0397] (Evaluation Criteria)

[0398] ◎: Less than 2MPa

[0399] ○: 2MPa or more and less than 5MPa

[0400] ×: 5MPa or more

[0401] <Manufacturing of acrylic polyol>

[0402] [Synthesis Example 1-1] (Manufacturing of acrylic polyol for coating composition preparation)

[0403] In a four-necked flask equipped with a stirring device, a thermometer, a condenser, and a nitrogen inlet, 29 parts by mass of propylene glycol monomethyl ether was added, and the temperature was raised to 112° C. under nitrogen blowing. After reaching 112° C., the nitrogen blowing was stopped, and a mixture containing 22.3 parts by mass of 2-hydroxyethyl methacrylate, 8.0 parts by mass of methyl methacrylate, 26.1 parts by mass of butyl acrylate, 42.3 parts by mass of styrene, 1.3 parts by mass of acrylic acid, and 2 parts by mass of 2,2'-azobis(isobutyronitrile) was added dropwise over 5 hours. Then, after stirring for 3 hours at 115° C. while blowing nitrogen, the mixture was cooled to 60° C., and a butyl acetate solution was added to obtain a solution of an acrylic polyol for preparing a coating composition having a solid content of 60% by mass. The glass transition temperature Tg of the acrylic polyol used in the preparation of the coating composition is 29.1°C, the hydroxyl value relative to the resin solid content is 139 mgKOH / g, and the weight average molecular weight Mw is 2.56×10 4 .

[0404] <Synthesis of polymers containing cross-linkable functional groups>

[0405] [Synthesis Example 1-2] (Synthesis of acrylic polymer OH1)

[0406] Into a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a condenser, 97 parts by mass of 2-ethylhexyl acrylate (2EHA) and 3 parts by mass of 4-hydroxybutyl acrylate (4-HBA) were added, and 145 parts by mass of ethyl acetate as a solvent was added. Then, 0.15 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator was added while stirring under a nitrogen atmosphere, and the mixture was reacted at 63°C for 8 hours. After the reaction, the mixture was cooled to obtain an acrylic polymer OH1 with a solid content concentration of 41.8% by mass. The glass transition temperature of the acrylic polymer OH1 measured by removing the solvent was -69°C, and the weight average molecular weight was 8.3×10 5 .

[0407] [Synthesis Example 1-3] (Synthesis of acrylic polymer OH2)

[0408] Into a four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a condenser, 97 parts by mass of n-butyl acrylate (BA) and 3 parts by mass of 4-hydroxybutyl acrylate (4-HBA) were added, and 145 parts by mass of ethyl acetate as a solvent was added. Then, 0.15 parts by mass of 2,2'-azobisisobutyronitrile (AIBN) as a polymerization initiator was added while stirring under a nitrogen atmosphere, and the reaction was carried out at 63°C for 8 hours. After the reaction, the mixture was cooled to obtain an acrylic polymer OH2 with a solid content concentration of 41.6% by mass. The glass transition temperature measured by removing the solvent of the acrylic polymer OH2 was -54°C, and the weight average molecular weight was 7.8×10 5 .

[0409] <Production of polyisocyanate composition 1>

[0410] [Example 1-1] (Production of polyisocyanate composition PA1-a1)

[0411] In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux condenser, 100 parts by mass of HDI were added under a nitrogen stream, and 1.8 parts by mass of a bifunctional polycaprolactone polyol A1 (hereinafter sometimes referred to as "polyol A1" or simply "A1") (manufactured by Daicel Corporation, trade name "PLACCEL 220", number average molecular weight 2000) and 33 parts by mass of a trifunctional polycaprolactone polyol B1 (hereinafter sometimes referred to as "polyol B1" or simply "B1") (manufactured by Daicel Corporation, trade name "PLACCEL 308", number average molecular weight 850) were stirred (in an amount such that the molar ratio of the isocyanate group of HDI to the hydroxyl group of the polyol A1 and the polyol B1 was 10.2) while the temperature in the reactor was maintained at 95° C. for 100 minutes. The reaction was stopped at the point where the yield was 41% by mass. After filtering the reaction liquid, unreacted HDI was removed by a thin film distillation apparatus to obtain a polyisocyanate composition PA1-a1.

[0412] [Examples 1-2 to 1-13 and Comparative Examples 1-2 to 1-3] (Production of polyisocyanate compositions PA1-a2 to PA1-a13 and PA1-b2 to PA1-b3)

[0413] Each polyisocyanate composition was obtained by the same method as in Example 1-1 except that the composition was set as shown in Tables 1-1 to 1-2 and 1-4.

[0414] [Example 1-14] (Production of polyisocyanate composition PA1-a14)

[0415] In a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of the polyisocyanate composition PA1-a3 obtained in Example 1-3, 0.6 parts by mass of methoxypolyethylene glycol (MPG-081, ethylene oxide repeating unit: 15, manufactured by Nippon Emulsifier Co., Ltd.) and 0.08 parts by mass of 2-ethylhexyl acid phosphate (JP-508T, manufactured by Johoku Chemical Industry Co., Ltd.) were mixed under a nitrogen stream and stirred at 95° C. for 2 hours to obtain a polyisocyanate composition PA1-a14.

[0416] [Examples 1-15 to 1-18] (Production of polyisocyanate compositions PA1-a15 to PA1-a18, PA1-a20 to PA1-a21)

[0417] Each polyisocyanate composition was obtained by the same method as in Example 1-1 except that the composition was set as shown in Table 1-3. In addition, for PA1-a20 and PA1-a21, the reaction was stopped when the yield reached 44% and 48%, respectively. Other treatments were performed by the same method as in Example 1-1.

[0418] [Example 1-19] (Production of polyisocyanate composition PA1-a19)

[0419] 100 parts by mass of HDI were added to a four-necked flask equipped with a thermometer, a stirring blade, and a reflux condenser under a nitrogen stream, and 10 parts by mass of a bifunctional polycaprolactone polyol A4 (hereinafter sometimes referred to as "polyol A4" or simply "A4") (manufactured by Daicel Corporation, trade name "PLACCEL 220CPT", number average molecular weight 2000) and 32 parts by mass of a trifunctional polycaprolactone polyol B1 (hereinafter sometimes referred to as "polyol B1" or simply "B1") (manufactured by Daicel Corporation, trade name "PLACCEL 308", number average molecular weight 850) (an amount such that the molar ratio of the isocyanate group of HDI to the hydroxyl group of the polyol A1 and the polyol B1 is 9.8) were stirred while the temperature in the reactor was maintained at 95°C for 100 minutes. The reaction was stopped at the moment when the yield reached 41% by mass. After filtering the reaction solution, unreacted HDI was removed by a thin film distillation apparatus to obtain a polyisocyanate composition. In a four-necked flask equipped with a thermometer, a stirring blade, and a reflux condenser, 3 parts by mass (NCO / OH=24.4) of a bifunctional polycaprolactone polyol A4 (manufactured by Daicel Corporation, trade name "PLACCEL 220CPT", number average molecular weight 2000) were mixed with 100 parts by mass of the obtained polyisocyanate under a nitrogen stream, 0.060 parts by mass of JP-508T was added, and the temperature in the reactor was maintained at 105° C. for 120 minutes to obtain a polyisocyanate composition PA1-a19.

[0420] [Comparative Example 1-1] (Production of polyisocyanate composition PA1-b1)

[0421] Into a four-necked flask equipped with a thermometer, a stirring blade and a reflux condenser, 100 parts by mass of HDI and 8.9 parts by mass of trimethylolpropane were added under a nitrogen flow, and the temperature in the reactor was maintained at 75° C. for 5 hours under stirring to carry out a urethanization reaction. After filtering the reaction liquid, unreacted HDI was removed using a thin film evaporator to obtain a polyisocyanate composition PA1-b1 containing an isocyanurate-type polyisocyanate.

[0422] The physical properties of the polyisocyanate composition 1 obtained in the examples and comparative examples, and the results of evaluation by the above-described methods are shown in the following Tables 1-1 to 1-4. It should be noted that in Comparative Example 1-1, when measuring the stress at an elongation of 140%, the elongation was not elongated to 140%, and the breaking stress was 72 MPa, which could not be measured, so it was recorded as "-" in the table.

[0423] In addition, in Table 1-1 to Table 1-4, each abbreviation means the following compound.

[0424] (Polyol (A1))

[0425] A1-1: bifunctional polycaprolactone polyol, manufactured by Daicel Corporation, trade name "PLACCEL 220", number average molecular weight 2000

[0426] A1-2: bifunctional polycaprolactone polyol, manufactured by Daicel Corporation, trade name "PLACCEL 230", number average molecular weight 3000

[0427] A1-3: bifunctional polycaprolactone polyol, manufactured by Daicel Corporation, trade name "PLACCEL 240", number average molecular weight 4000

[0428] A1-4: bifunctional polycaprolactone polyol, manufactured by Daicel Corporation, trade name "PLACCEL 220CPT", number average molecular weight 2000

[0429] A1'-1: polytetramethylene ether glycol, manufactured by Mitsubishi Chemical Corporation, trade name "PTMG1000", number average molecular weight 1000

[0430] A1'-2: polyether polyol, manufactured by AGC Corporation, trade name "Exenol 2020", number average molecular weight 2000, hydroxyl value 55.8 mg / KOH

[0431] A1'-3: polyether polyol, manufactured by AGC Corporation, trade name "Exenol 4030", number average molecular weight 4000, hydroxyl value 42 mg / KOH

[0432] A1'-4: Polycarbonate diol, manufactured by Asahi Kasei Co., Ltd., trade name "T5652", number average molecular weight 2000, hydroxyl value 56.0 mg / KOH

[0433] (Polyol (B1))

[0434] B1-1: trifunctional polycaprolactone polyol, manufactured by Daicel Corporation, trade name "PLACCEL 308", number average molecular weight 850

[0435] B1-2: trifunctional polycaprolactone polyol, manufactured by Daicel Corporation, trade name "PLACCEL 312", number average molecular weight 1250

[0436] B1-3: trifunctional polycaprolactone polyol, manufactured by Daicel Corporation, trade name "PLACCEL 305", number average molecular weight 550

[0437] B1'-1: Trimethylolpropane (TMP)

[0438] [Table 1-1]

[0439]

[0440] [Table 1-2]

[0441]

[0442] [Table 1-3]

[0443]

[0444] [Table 1-4]

[0445]

[0446] In the case of the polyisocyanate compositions PA1-a1 to PA1-a21 (Examples 1-1 to 1-21) derived from a diisocyanate and two polyols having a number average molecular weight within a specific numerical range and having a weight average molecular weight of 1400 or more, the hardness when formed into a cured film is low and the flexibility is good, the elongation when formed into a coating film and the stress at an elongation of 140% are good, and the adhesion, cohesion, curability and transparency when formed into an adhesive sheet are excellent.

[0447] On the other hand, in the case of the polyisocyanate compositions PA1-b1 to PA1-b2 (Comparative Examples 1-1 to 1-2) derived from a diisocyanate and one polyol or having a weight average molecular weight of less than 1400, or the polyisocyanate composition PA1-b3 (Comparative Example 1-3) derived from a diisocyanate and two polyols having number average molecular weights outside the specific numerical range and having a weight average molecular weight of less than 1400, good flexibility when formed into a cured film and good adhesion, cohesion, curability and transparency when formed into an adhesive sheet were not obtained.

[0448] <Production of polyisocyanate composition 2>

[0449] [Example 2-1]

[0450] (Production of polyisocyanate composition PA2-a1)

[0451] A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel was set to a nitrogen atmosphere, and 1000 g of HDI and 496.0 g of a trifunctional polycaprolactone polyol (manufactured by DIC Corporation, trade name "OD-X2588", number average molecular weight 1250) were added, and the temperature in the reactor was kept at 100° C. under stirring to carry out a urethanization reaction. After filtering the reaction liquid, unreacted HDI was removed using a thin film evaporator to obtain a polyisocyanate precursor. 100.0 g of the polyisocyanate precursor was added to the flask, and 57.0 g of polyoxypropylene diol (manufactured by AGC Corporation, trade name "EXCENOL 510", number average molecular weight 4000) was added, and the temperature in the reactor was kept at 100° C. under stirring to carry out a urethanization reaction to obtain a polyisocyanate composition PA2-a1.

[0452] [Examples 2-2 to 2-6]

[0453] (Production of polyisocyanate compositions PA2-a2 to PA2-a6)

[0454] Each polyisocyanate composition was obtained by the same method as in Example 2-1 except that the composition was set as shown in Table 2-1.

[0455] [Example 2-7]

[0456] (Production of polyisocyanate composition PA2-a7)

[0457] A four-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a nitrogen blowing tube, and a dropping funnel was set to a nitrogen atmosphere, and 1000 g of HDI, a trifunctional polycaprolactone polyol (manufactured by DIC Corporation, trade name "OD-X2735", number average molecular weight 500) 150.0 g, polytetramethylene ether glycol (manufactured by Mitsubishi Chemical Corporation, trade name "PTMG1000", number average molecular weight 1000) 200.0 g and polyoxypropylene glycol (manufactured by AGC Corporation, trade name "EXCENOL 510", number average molecular weight 4000) 300.0 g were added, and the temperature in the reactor was maintained at 100° C. under stirring to carry out a urethanization reaction. After filtering the reaction liquid, unreacted HDI was removed using a thin film evaporator to obtain a polyisocyanate composition PA2-a6.

[0458] [Example 2-8 and Comparative Examples 2-1 to 2-3]

[0459] (Manufacture of polyisocyanate compositions PA2-a8 and PA2-b1 to PA2-b3)

[0460] Each polyisocyanate composition was obtained by the same method as in Example 2-7 except that the composition was set as shown in Table 2-2.

[0461] The physical properties of each polyisocyanate composition obtained and the evaluation results using the methods described above are shown in Table 2-1 and Table 2-2.

[0462] In addition, each abbreviation in Table 2-1 and Table 2-2 represents the following compound.

[0463] (Polycaprolactone polyol (A2))

[0464] A2: Polycaprolactone polyol

[0465] OD-X-2735: Made by DIC Co., Ltd., trifunctional polycaprolactone polyol, number average molecular weight 500

[0466] OD-X-2586: Made by DIC Co., Ltd., trifunctional polycaprolactone polyol, number average molecular weight 850

[0467] OD-X-2588: Made by DIC Co., Ltd., trifunctional polycaprolactone polyol, number average molecular weight 1250

[0468] (Polyether polyol (B2))

[0469] B2-1: Polypropylene glycol

[0470] Excenol 510: Made by AGC Co., Ltd., polyoxypropylene glycol, number average molecular weight 4000

[0471] Excenol840: Made by AGC Co., Ltd., polyoxypropylenetriol, number average molecular weight 6500

[0472] Excenol1020: Made by AGC Co., Ltd., polyoxypropylene glycol, number average molecular weight 1000

[0473] B2-2: Other polyether polyols

[0474] PTMG1000: manufactured by Mitsubishi Chemical Corporation, polytetramethylene ether glycol, number average molecular weight 1000

[0475] [Table 2-1]

[0476]

[0477] [Table 2-2]

[0478]

[0479] In the case of the polyisocyanate compositions PA2-a1 to PA2-a8 (Examples 2-1 to 2-8) derived from diisocyanate, polycaprolactone polyol (A2) and polyether polyol (B2) and containing 20 parts by mass or more of polypropylene glycol relative to 100 parts by mass of polyether polyol (B2), the compatibility with the main agent is good in a low temperature environment of about -10°C, and the elongation at break at a low temperature of about -10°C when the coating film is made, as well as the low stress properties at a low temperature of about -10°C and at a normal temperature of about 23°C are excellent.

[0480] In the case of the polyisocyanate composition PA2-b1 (Comparative Example 2-1) derived from diisocyanate and polycaprolactone polyol (A2), the compatibility with the main agent is good in a low temperature environment of about -10°C, but the elongation at break at a low temperature of about -10°C when the coating film is made and the low stress properties at a low temperature of about -10°C and at a normal temperature of about 23°C are poor.

[0481] In addition, in the case of the polyisocyanate composition PA2-b2 (Comparative Example 2-2) derived from a diisocyanate, a polycaprolactone polyol (A2) and a polyether polyol (B2) not containing polypropylene glycol, the elongation at break at a low temperature of about -10°C when formed into a coating film, and the low stress properties at a low temperature of about -10°C and at a normal temperature of about 23°C are within the allowable range, but the compatibility with the main agent is poor in a low temperature environment of about -10°C.

[0482] In addition, in the case of the polyisocyanate composition PA2-b3 (Comparative Example 2-3) derived from a diisocyanate, a polycaprolactone polyol (A2) and a polyether polyol (B2) and containing less than 20 parts by mass (10 parts by mass) of polypropylene glycol relative to 100 parts by mass of the polyether polyol (B2), the elongation at break at a low temperature of about -10°C when the coating film is made and the low stress properties at a low temperature of about -10°C and at a normal temperature of about 23°C are within the allowable range, but the compatibility with the main agent is poor in a low temperature environment of about -10°C.

[0483] Industrial Applicability

[0484] According to the polyisocyanate composition 1 of the present embodiment, it is possible to provide a polyisocyanate composition which has good flexibility when a cured film formed by curing the polyisocyanate composition alone and can provide a pressure-sensitive adhesive sheet having excellent adhesiveness, cohesive force, curability, and transparency.

[0485] Furthermore, the polyisocyanate composition 2 of this embodiment can provide a polyisocyanate composition having good compatibility with the main agent in a low temperature environment of about -10°C and excellent flexibility at a low temperature of about -10°C and a normal temperature of about 23°C when formed into a coating film.

Claims

1. A polyisocyanate composition derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, a bifunctional polyol (A1) having a number average molecular weight of 1500 or more, and a trifunctional or higher polyol (B1) having a number average molecular weight of 500 or more, The molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyol (A1) and the polyol (B1) is 2 or more and 30 or less, The weight average molecular weight of the polyisocyanate composition is greater than 1400. The polyol (A1) and the polyol (B1) are polyester polyols.

2. The polyisocyanate composition according to claim 1, in, The mass ratio of the alicyclic diisocyanate to the aliphatic diisocyanate is 0 / 100 or more and 30 / 70 or less.

3. The polyisocyanate composition according to claim 1 or 2, in, The molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polyol (A1) and the polyol (B1) is 5 or more and 20 or less.

4. The polyisocyanate composition according to claim 1 or 2, in, The number average molecular weight of the polyol (A1) is 7,000 or less.

5. The polyisocyanate composition according to claim 1 or 2, in, The number average molecular weight of the polyol (B1) is 3,000 or less.

6. The polyisocyanate composition according to claim 1 or 2, in, The weight average molecular weight of the polyisocyanate composition is 100,000 or less.

7. The polyisocyanate composition according to claim 1 or 2, in, The mass ratio of the polyol (A1) to the polyol (B1), that is, the mass ratio of (A1) / (B1) is 0.1 / 99.9 or more and 99.9 / 0.1 or less, and With respect to 100 parts by mass of the diisocyanate, The content of the polyol (A1) is 0.1 parts by mass or more and 250 parts by mass or less, The content of the polyol (B1) is 1 part by mass or more and 190 parts by mass or less.

8. The polyisocyanate composition according to claim 7, in, The mass ratio of (A1) / (B1) is 7 / 93 or more and 70 / 30 or less.

9. The polyisocyanate composition according to claim 7, in, The content of the polyol (A1) is 1.7 parts by mass or more and 38 parts by mass or less.

10. The polyisocyanate composition according to claim 7, in, The content of the polyol (B1) is 12 parts by mass or more and 50 parts by mass or less.

11. The polyisocyanate composition according to claim 1 or 2, in, The polyisocyanate composition has an average isocyanate functional group number of 2 or more and 6 or less.

12. The polyisocyanate composition according to claim 1 or 2, in, The polyisocyanate composition has an average isocyanate functional group number of 2.5 or more and 5.5 or less.

13. The polyisocyanate composition according to claim 1 or 2, in, The polyisocyanate composition has an isocyanate group content of 1% by mass or more and 10% by mass or less.

14. The polyisocyanate composition according to claim 1 or 2, in, The polyol (A1) and the polyol (B1) are polycaprolactone polyols.

15. A cured film having a thickness of 40 μm formed by applying the polyisocyanate composition according to any one of claims 1 to 14 onto glass, storing the film at 23°C and 65% humidity for 168 hours, and then heating the film at 50°C for 24 hours, The cured film has a Koenig hardness of 60 times or less under a 23° C. environment.

16. A coating film having a thickness of 40 μm after the coating composition is cured at 90° C. for 30 minutes and stored at 23° C. and 65% humidity for 168 hours, the coating composition comprising the polyisocyanate composition according to any one of claims 1 to 14 and a polyisocyanate having a glass transition temperature of 29.1° C., a hydroxyl value of 139 mgKOH / g and a weight average molecular weight of 2.56×10 4 Acrylic polyols, In a tensile test in which a test piece of the coating film having a width of 10 mm and a length of 100 mm was set in a tensile testing machine with a clamp distance of 20 mm and measured at a speed of 20 mm / min, the elongation of the coating film was 50% or more and the stress at an elongation of 140% was 28 MPa or less. 17 . An adhesive composition comprising the polyisocyanate composition according to claim 1 and a crosslinkable functional group-containing polymer having a glass transition temperature of 0° C. or less.

18. The adhesive composition according to claim 17, in, The crosslinkable functional group-containing polymer is an acrylic polymer.

19. An adhesive sheet comprising: substrate; and an adhesive layer located on the substrate, The adhesive layer comprises a cured product of the adhesive composition according to claim 17 or 18.

20. The adhesive sheet according to claim 19, in, The adhesive layer has a thickness of 1 μm or more and 1000 μm or less.

21. The adhesive sheet according to claim 19 or 20, in, An adhesive sheet having an adhesive layer with a thickness of 50 μm is stored in an environment of 23°C and 50% RH for 7 days, then wrapped with a mesh sheet, immersed in ethyl acetate at 23°C for 1 week, taken out and dried at 120°C for 2 hours, and the calculated gel fraction is 20% by mass or more and 99% by mass or less. The adhesive sheet having an adhesive layer with a thickness of 50 μm is formed by coating the adhesive composition on a 38 μm thick release-treated polyethylene terephthalate film and drying it at 130°C for 3 minutes to cure it.

22. The adhesive sheet according to claim 19 or 20, in, After storing an adhesive sheet having a width of 20 mm and a length of 100 mm and an adhesive layer having a thickness of 50 μm at 23°C and 50% RH for 7 days, a SUS304BA steel plate is used as an adherend and crimped with a 2 kg roller by moving it back and forth once. After aging at 23°C for 30 minutes, the 180-degree peel adhesion measured at a speed of 300 mm / min at 23°C is 0.05 N / 20 mm or more and 55 N / 20 mm or less. The adhesive sheet having a width of 20 mm and a length of 100 mm and having an adhesive layer having a thickness of 50 μm is formed by coating the adhesive composition on a polyethylene terephthalate film having a thickness of 25 μm and drying it at 130°C for 3 minutes to cure it.

23. The adhesive sheet according to claim 19 or 20, in, The adhesive layer with a thickness of 50 μm formed by coating the adhesive composition on a 38 μm thick release-treated polyethylene terephthalate film and drying it at 130°C for 3 minutes to cure it is peeled off from the release-treated polyethylene terephthalate film and then bonded to glass with a haze value of 0.1%. The haze value of the adhesive sheet obtained thereby, as measured by a haze meter, is less than 2%.

24. A coating film, a film and an adhesive composition, which is a resin film having a thickness of 40 μm after the resin composition is cured at 90° C. for 30 minutes and stored at 23° C. and 65% humidity for 168 hours, the resin composition comprising the polyisocyanate composition according to any one of claims 1 to 14 and a polyisocyanate having a glass transition temperature of 0° C. to 100° C., a hydroxyl value of 10 mgKOH / g to 400 mgKOH / g, and a weight average molecular weight of 5.00×10 3 Above and 1.0×10 5 The following acrylic polyols, The resin film has a breaking stress of 2.0 MPa or more in a tensile test in which a test piece of the resin film having a width of 10 mm and a length of 100 mm is set in a tensile testing machine with a clamp distance of 20 mm and measured at a speed of 20 mm / min.

25. A coating film, a film and an adhesive composition, which is a resin film having a thickness of 40 μm after the resin composition is cured at 90° C. for 30 minutes and stored at 23° C. and 65% humidity for 168 hours, the resin composition comprising the polyisocyanate composition according to any one of claims 1 to 14 and a polyisocyanate having a glass transition temperature of 0° C. to 100° C., a hydroxyl value of 10 mgKOH / g to 400 mgKOH / g, and a weight average molecular weight of 5.00×10 3 Above and 1.0×10 5 The following acrylic polyols, In a tensile test in which a test piece of the resin film having a width of 10 mm and a length of 100 mm was set in a tensile testing machine with a clamp distance of 20 mm and measured at a speed of 20 mm / min, the breaking stress of the resin film was 1.1 or more relative to the stress at 140% elongation.

26. A polyisocyanate composition derived from at least one diisocyanate selected from the group consisting of aliphatic diisocyanates and alicyclic diisocyanates, a polycaprolactone polyol (A2) and a polyether polyol (B2), The polyether polyol (B2) contains 20 parts by mass or more of polypropylene glycol, The polyisocyanate composition has an isocyanate group content of 3% by mass or more and 8% by mass or less.

27. The polyisocyanate composition according to claim 26, in, The number average molecular weight of the polycaprolactone polyol (A2) is 500 or more and 1500 or less, and The number average molecular weight of the polyether polyol (B2) is 1,000 or more and 7,000 or less.

28. The polyisocyanate composition according to claim 27, in, The number average molecular weight of the polycaprolactone polyol (A2) is 700 or more and 1500 or less.

29. The polyisocyanate composition according to claim 27 or 28, in, The number average molecular weight of the polyether polyol (B2) is 3,000 or more and 6,700 or less.

30. The polyisocyanate composition according to claim 27 or 28, in, In the polyether polyol (B2), the mass ratio of polytetramethylene ether glycol to the polypropylene glycol is 0 / 100 or more and 60 / 40 or less.

31. The polyisocyanate composition according to claim 27 or 28, in, In the polyether polyol (B2), the mass ratio of polytetramethylene ether glycol to the polypropylene glycol is 0 / 100 or more and 45 / 55 or less.

32. The polyisocyanate composition according to claim 26 or 27, in, The molar ratio of the isocyanate group of the diisocyanate to the hydroxyl group of the polycaprolactone polyol (A2) and the polyether polyol (B2) is 2 or more and 10 or less.

33. The polyisocyanate composition according to claim 26 or 27, in, The mass ratio of the polycaprolactone polyol (A2) to the polyether polyol (B2) is 10 / 90 or more and 90 / 10 or less. 34 . A resin composition comprising the polyisocyanate composition according to claim 26 and a polyol. The resin composition according to claim 34 , which is an adhesive composition.

Images