Laminate, method for manufacturing a laminate, and component set

Abstract

To provide a laminate or the like that has excellent re-peelability short time after bonding and high interlayer adhesion. [Solution] A laminate comprising a substrate treated with active energy rays and a cured layer of a moisture-curable polyurethane hot melt resin composition, wherein the moisture-curable polyurethane hot melt resin composition contains a urethane prepolymer (i) having isocyanate groups, and the urethane prepolymer (i) is made from a polyol (A) with crystalline polyester polyol (a1) and amorphous polyester polyol (a2) as essential components, and polyisocyanate (B), and has an α value represented by the following formula (1) in the range of 8.0 to 11.0.

Description

Technical Field

[0001] The present disclosure relates to a laminate having a cured product layer of a moisture-curable polyurethane hot melt resin composition.

Background Art

[0002] In the fields of decorative boards and window frame sashes, etc., wood-based materials such as particle boards and plywood have been mainly used until now (see, for example, Patent Document 1). However, due to the recent supply instability of wood, the material conversion from wood-based materials to non-wood materials has been progressing, and aluminum substrates, etc. have begun to be used.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] On the other hand, in the case of a failure in bonding between a substrate and a sheet due to a defect in the manufacturing process of a window frame sash or the like, there is a demand for reworkability such that the substrate can be disassembled and reused, and imparting re-peelability to the adhesive is required. However, excellent adhesiveness and re-peelability are completely opposite performances, and at present, it is quite difficult to achieve both of these.

[0005] Among these, in order to achieve a strong adhesive force between the adhesive and the substrate, it is necessary to improve the wettability of the adhesive. On the other hand, when the wettability of the adhesive is improved, the curing of the adhesive becomes slower. Therefore, until sufficient curing progresses, glue residue is likely to occur during peeling, and there is a problem that good re-peelability cannot be achieved. In particular, with the progress of shortening the process time for re-sticking the substrate and the sheet, there is a situation where the above problems become prominent. Therefore, for the adhesive used for bonding the substrate and the sheet, compatibility between high re-peelability with respect to the substrate in a short time after bonding and high adhesive force (final adhesive strength) with respect to the substrate is required.

[0006] The present disclosure has been made in view of the above circumstances, and provides a laminate having excellent re-peelability in a short time after bonding and high interlayer adhesiveness.

Means for Solving the Problems

[0007] As a result of intensive studies by the present inventors, depending on the type of surface treatment of the substrate and the initial curability of the adhesive, when it is desired to peel off the substrate and the sheet through the adhesive in a short time after bonding, there are cases where the adhesive is not sufficiently cured and material failure occurs, resulting in a significant decrease in re-peelability, or cases where the high adhesive force (final adhesive strength) of the adhesive with respect to the substrate is greatly reduced, making interlayer peeling likely to occur within the laminate. As a result of further intensive studies by the present inventors, a combination of a substrate and an adhesive has been found that is excellent in re-peelability in a short time after bonding and has a strong interlayer adhesive force after curing, leading to the laminate of the present disclosure.

[0008] The present disclosure includes the following embodiments. [1] A laminate comprising a substrate treated with active energy rays and a cured layer of a moisture-curable polyurethane hot-melt resin composition, wherein the moisture-curable polyurethane hot-melt resin composition contains a urethane prepolymer (i) having isocyanate groups, and the urethane prepolymer (i) is made from a polyol (A) having crystalline polyester polyol (a1) and amorphous polyester polyol (a2) as essential components, and polyisocyanate (B), and the α value represented by the following formula (1) is in the range of 8.0 to 11.0. α = [δp] ÷ [γCPES] …(1) (The wording in formula (1) above refers to the following: δp: Polarity term of the surface free energy of the substrate. γCPES: The proportion of the crystalline polyester polyol (a1) in the total mass of the raw materials constituting the urethane prepolymer (i). [2] A laminate comprising a substrate and a cured layer of a moisture-curing polyurethane hot-melt resin composition, wherein the moisture-curing polyurethane hot-melt resin composition contains a urethane prepolymer (i) having an isocyanate group, and the urethane prepolymer (i) is made from a polyol (A) having crystalline polyester polyol (a1) and amorphous polyester polyol (a2) as essential components, and polyisocyanate (B), wherein the interlayer adhesion between the substrate and the cured layer is 40 N / inch or more, and the α value represented by the following formula (1) is in the range of 8 to 11. α = [δp] ÷ [γCPES] …(1) (The wording in formula (1) above refers to the following: δp: Polarity term of the surface free energy of the substrate. γCPES: The proportion of the crystalline polyester polyol (a1) in the total mass of the raw materials constituting the urethane prepolymer (i). [3] The laminate according to [1] or [2], wherein the content of the crystalline polyester polyol (a1) is in the range of 15% to 80% by mass in 100% by mass of polyol (A). [4] The laminate according to any one of [1] to [3], wherein the content of the amorphous polyester polyol (a2) is in the range of 10% to 80% by mass in 100% by mass of polyol (A). [5] The laminate according to any one of [1] to [4], wherein the blending ratio [(a1) / (a2)] of the crystalline polyester polyol (a1) and the amorphous polyester polyol (a2) is in the range of 0.8 to 1.7. [6] The laminate according to any one of [1] to [3], wherein the base material is an aluminum base material. [7] A method for manufacturing a laminate according to any one of [1] to [3] above, comprising the steps of: irradiating a substrate with active energy rays; and arranging a precursor layer made of a moisture-curable polyurethane hot-melt resin composition on the active energy ray irradiated surface of the substrate. [8] A method for manufacturing a laminate according to [7], wherein the substrate and the precursor layer are bonded together and the substrate and the precursor layer are interfacially peelable after 5 minutes. [9] A parts set comprising a base material and a sheet having an adhesive layer, wherein the first surface of the base material and the surface of the adhesive layer of the sheet are bonded together, the adhesive layer being formed from a moisture-curing polyurethane hot melt resin composition, the moisture-curing polyurethane hot melt resin composition containing a urethane prepolymer (i) having an isocyanate group, the urethane prepolymer (i) being made from a polyol (A) having crystalline polyester polyol (a1) and amorphous polyester polyol (a2) as essential components, and polyisocyanate (B), and having an α value represented by the following formula (1) in the range of 8.0 to 11.0. α = [δp] ÷ [γCPES] …(1) (The wording in formula (1) above refers to the following: δp: Polarity term of the surface free energy of the substrate. γCPES: The proportion of the crystalline polyester polyol (a1) in the total mass of the raw materials constituting the urethane prepolymer (i).

[10] The component set according to [9], wherein the first surface of the substrate is treated with active energy rays.

[11] The parts set according to [9] or

[10] , wherein the interlayer adhesive strength between the substrate and the cured layer is 40 N / inch or more.

[12] A component set according to any one of [9] to

[11] , wherein the adhesive layer and the substrate are bonded together and then interfacially peelable between the adhesive layer and the substrate after 5 minutes. [Effects of the Invention]

[0009] The laminate of this disclosure exhibits excellent re-peelability of the substrate and the pre-curing moisture-curable polyurethane hot-melt resin composition shortly after bonding, and has high interlayer adhesion between the substrate and the cured layer. [Modes for carrying out the invention]

[0010] I. Laminate The laminate of the present disclosure comprises a substrate and a cured layer of a moisture-curable polyurethane hot-melt resin composition, wherein the moisture-curable polyurethane hot-melt resin composition contains a urethane prepolymer (i) having isocyanate groups, and the urethane prepolymer (i) is made from a polyol (A) having crystalline polyester polyol (a1) and amorphous polyester polyol (a2) as essential components, and polyisocyanate (B). The laminate of this disclosure has an α value represented by the following formula (1) in the range of 8.0 to 11.0. α = [δp] ÷ [γCPES] …(1) (The wording in formula (1) above refers to the following: δp: Polarity term of the surface free energy of the substrate. γCPES: The proportion of the crystalline polyester polyol (a1) in the total mass of the raw materials constituting the urethane prepolymer (i).

[0011] One embodiment of the laminate of the present disclosure is one in which the substrate is treated with active energy rays.

[0012] One embodiment of the laminate of the present disclosure is one in which the interlayer adhesive strength between the substrate and the cured layer is 40 N / inch or more.

[0013] The laminate of the present disclosure has an α value represented by formula (1) in the range of 8.0 to 11.0, with a preference for the range of 8.5 to 11.0, a more preference for the range of 9.0 to 11.0, and an even more preference for the range of 9.5 to 10.5.

[0014] Generally, the higher the polarity term of the surface free energy of the substrate, the better the wettability of the substrate and the better the adhesion to the cured product of the moisture-curing polyurethane hot-melt resin composition. However, this also makes it difficult to re-peel the substrate from the moisture-curing polyurethane hot-melt resin composition before curing. Surface treatment methods such as corona treatment and plasma treatment can improve wettability and adhesion by introducing polar functional groups to the surface of the substrate. However, these treatment methods involve a large degree of surface modification, which can increase the wettability of the substrate more than necessary. This can lead to increased affinity between the substrate and the moisture-curing polyurethane hot-melt resin composition, potentially worsening the ability to re-peel off shortly after bonding. Furthermore, with moisture-curing polyurethane hot-melt resin compositions, increasing the adhesion to the substrate after curing (final adhesive strength) reduces the initial solidification properties. If only a short time, such as 5 minutes, has passed since bonding to the substrate, solidification may not proceed sufficiently, resulting in poor re-peelability when peeling from the substrate. On the other hand, while increasing the initial solidification properties of moisture-curing polyurethane hot-melt resin compositions allows for high re-peelability even when peeled off a short time after bonding to the substrate, it may reduce the adhesion to the substrate after curing (final adhesive strength), potentially resulting in inferior interlayer adhesive strength of the laminate. Therefore, there is a need to improve the interlayer adhesive strength between the substrate and the cured layer without significantly affecting the wettability of the substrate or worsening re-peelability shortly after bonding.

[0015] In contrast, according to the present invention, by ensuring that the value obtained by dividing the polar term of the surface free energy of the base material described by the above formula (1) by the amount of the crystalline component in the moisture-curing type polyurethane hot melt resin composition falls within a specific range, it is possible to achieve both excellent releasability in a short time after bonding between the base material and the moisture-curing type polyurethane hot melt resin composition and excellent adhesion between the base material and the cured product layer.

[0016] The surface free energy (polar term and dispersion term) of the base material was measured by measuring the contact angles of the measurement solutions (water and diiodomethane) on the base material using a contact angle meter ("PCA-11" manufactured by Kyowa Interface Science Co., Ltd.). Based on this result, the surface free energy of the base material was calculated using the following formula (2). For the calculation, software "FAMAS" manufactured by Kyowa Interface Science Co., Ltd. was used, and the Owens-Wendt method was employed. (δd L +δp L )·(1 + cosθ) / 2 = (δd·δd L ) 1 / 2 +(δp·δp L ) 1 / 2 …(2)

[0017] The symbols in the above formula (2) are as follows. δd: Dispersion term of the surface free energy of the base material δp: Polar term of the surface free energy of the base material δd L : Dispersion term of the surface free energy of the measurement solution [[ID=3l]] δp L : Polar term of the surface free energy of the measurement solution δd of water L : 21.8 mJ / m -2 、δp L : 51.0 mJ / m -2 δd of diiodomethane L : 49.5 mJ / m -2 、δp L : 1.3 mJ / m -2

[0018] The laminate of the present disclosure preferably has an interlayer adhesive strength of 40 N / inch or more between the substrate and the cured layer, more preferably 45 N / inch or more, even more preferably 50 N / inch or more, and even more preferably 55 N / inch or more. Having an interlayer adhesive strength within this range allows for strong adhesion between the substrate and the cured layer, thereby suppressing the destruction of the laminate due to delamination between the substrate and the cured layer.

[0019] The following describes in detail the various components and manufacturing methods of the laminates described herein.

[0020] 1. Base material Examples of the aforementioned substrates include resin substrates such as acrylic resins, urethane resins, silicone resins, epoxy resins, fluororesins, polystyrene resins, polyester resins, polysulfone resins, polyarylate resins, polyvinyl chloride resins, polyvinylidene chloride, cycloolefin resins, polyolefin resins, polyimide resins, alicyclic polyimide resins, cellulose resins, PC (polycarbonate), PBT (polybutylene terephthalate), modified PPE (polyphenylene ether), PEN (polyethylene naphthalate), PET (polyethylene terephthalate), lactic acid polymers, ABS resins, and AS resins; fiber substrates such as nonwoven fabrics, woven fabrics, and knitted fabrics; and metal substrates such as stainless steel, aluminum, copper, iron, chromium, zinc, duralumin, die-cast metals, and alloys thereof.

[0021] Among these, metal substrates are preferred, and aluminum substrates, in particular, are preferred as reworkability is required.

[0022] The surface free energy of the substrate is not particularly limited, but the dispersion term is, for example, 25.0 mJ / m 2 ~45.0 mJ / m 2 A range of 30.0 mJ / m is preferred. 2 ~40.0 mJ / m 2 A range of 30.0 mJ / m is more preferable. 2 ~35.0 mJ / m 2 A range of 2.5 mJ / m is even more preferable. Also, a polarity term of 2.5 mJ / m2 A range of ~10.0 is preferred, and 3.0 mJ / m 2 ~6.0 mJ / m 2 A more preferable range is obtained when the dispersion term and polarity term of the surface free energy of the substrate are independently within the above range, thereby making it easier to achieve the effect of having the α value relationship represented by formula (1) described above between the substrate and the moisture-curing polyurethane hot melt resin composition. The dispersion term and polarity term of the surface free energy of the substrate can be adjusted, for example, by the material of the substrate or by surface treatment by irradiation with active energy rays, as described later. The polarity and dispersion terms of the surface free energy of the substrate were calculated using the following equation (2) based on the contact angle of the measurement solution (water and diiodomethane) on the substrate, measured using a contact angle meter (PCA-11, manufactured by Kyowa Interface Science Co., Ltd.). The calculation was performed using the Owens-Wendt method with the software "FAMAS" (manufactured by Kyowa Interface Science Co., Ltd.). ( δd L +δp L )·(1+cosθ) / 2=(δd·δd L ) 1 / 2 +(δp·δp L ) 1 / 2 …(2)

[0023] The signs in equation (2) above are as follows: δd: Dispersion term of the surface free energy of the substrate δp: Polarity term of the surface free energy of the substrate δd L : Dispersion term of the surface free energy of the measured solution δp L : Polarity term of the surface free energy of the measured solution δd of water L :21.8mJm -2 δp L :51.0mJm -2 Diiodomethane δd L :49.5mJm -2 δp L :1.3mJm -2

[0024] Preferably, the surface of the substrate is treated with active energy rays. The inventors have found that a substrate whose surface has been modified with active energy rays does not deteriorate as easily as a substrate with other surface treatments, and that the re-peelability in a short time after bonding with a moisture-curing polyurethane hot-melt resin composition, and that the interlayer adhesion between the substrate and the cured layer of the moisture-curing polyurethane hot-melt resin composition is improved. The reason for this is not clear, but it is presumed that the surface free energy of the substrate whose surface has been modified with active energy rays did not change significantly before and after the active energy ray treatment, compared to a substrate with other surface treatments. Therefore, the effects of the present invention can be achieved by having a relationship between the active energy ray-treated substrate and the moisture-curing polyurethane hot-melt resin composition in terms of the α value represented by the above formula (1). The specific method of surface treatment by irradiation with active energy rays will be described in the section "4. Method for Manufacturing Laminates" below.

[0025] The active energy rays irradiated onto the substrate surface are not particularly limited and include ionizing radiation such as ultraviolet rays, electron beams, alpha rays, beta rays, and gamma rays. Among these, ultraviolet rays are preferred because they can suppress the deterioration of the substrate. In other words, it is preferable that the substrate surface is treated with ultraviolet rays (surface treatment by ultraviolet irradiation).

[0026] In addition to having its surface treated with active energy rays, the substrate may also undergo other treatments such as corona treatment, plasma treatment, or primer treatment.

[0027] The thickness of the substrate is not particularly limited, but can be in the range of 1 mm to 50 mm, for example.

[0028] 2.Cured material layer The cured layer in this disclosure consists of a cured product of a moisture-curing polyurethane hot-melt resin composition containing a urethane prepolymer (i) having an isocyanate group.

[0029] <Moisture-curing polyurethane hot melt resin composition> The moisture-curing polyurethane hot-melt resin composition (hereinafter sometimes referred to as the resin composition in this disclosure) contains a urethane prepolymer (i) having isocyanate groups. The urethane prepolymer (i) having isocyanate groups is made from polyol (A) and polyisocyanate (B).

[0030] (Polyol (A)) The polyol (A) contains crystalline polyester polyol (a1) and amorphous polyester polyol (a2) as essential components to obtain excellent adhesive properties.

[0031] -Crystalline polyester polyol (a1)- The crystalline polyester polyol (a1) provides excellent adhesion due to its cohesive force, and examples include reaction products of compounds having two or more hydroxyl groups with polybasic acids; polycaprolactone polyols, etc. In this disclosure, "crystalline" refers to materials in which peaks of crystallization heat or fusion heat can be confirmed in DSC (differential scanning calorimeter) measurements in accordance with JIS K7121:2012, and "amorphous" refers to materials in which such peaks cannot be confirmed.

[0032] Examples of compounds having two or more hydroxyl groups include ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, octanediol, nonanediol, decanediol, trimethylolpropane, trimethylolethane, and glycerin. These compounds may be used individually or in combination of two or more. Among these, one or more selected from the group consisting of butanediol, hexanediol, octanediol, and decanediol are preferred because they enhance crystallinity and provide even better adhesion.

[0033] Examples of the polybasic acid that can be used include oxalic acid, malonic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, and dodecanedioic acid. These compounds may be used individually or in combination of two or more. Among these, one or more selected from the group consisting of succinic acid, adipic acid, sebacic acid, and dodecanedioic acid are preferred because they enhance crystallinity and provide even better adhesion.

[0034] As the caprolactone polyol, for example, a reaction product of a compound having two or more hydroxyl groups and ε-caprolactone can be used.

[0035] The number-average molecular weight of the crystalline polyester polyol (a1) is preferably 500 to 10,000 and more preferably 1,000 to 6,000 when using the reaction product of the compound having two or more hydroxyl groups and the polybasic acid, and preferably 5,000 to 200,000 and more preferably 10,000 to 100,000 when using the polycaprolactone polyol. The number-average molecular weight of the crystalline polyester polyol (a1) is shown as the value measured by gel permeation chromatography (GPC).

[0036] The content of the crystalline polyester polyol (a1) in the polyol (A) can be in the range of 15% to 80% by mass per 100% by mass of polyol (A) in order to obtain even better adhesion, with a range of 30% to 70% by mass being preferred, a range of 40% to 65% by mass being more preferred, and a range of 45% to 60% by mass being even more preferred.

[0037] -Amorphous polyester polyol (a2)- The amorphous polyester polyol (a2) has good compatibility with the crystalline polyester polyol (a1) and can form a dense and tough adhesive film. For example, a reaction product of a polybasic acid with a compound having two or more hydroxyl groups, which contains a component that disrupts the crystalline structure, such as an alkylene oxide adduct of bisphenol A or a compound having a branched structure, can be used.

[0038] In the alkylene oxide adduct of bisphenol A, the alkylene can have 1 to 10 carbon atoms, and the number of moles of alkylene oxide added is preferably in the range of 2 moles to 10 moles, and more preferably in the range of 4 moles to 8 moles.

[0039] Examples of compounds having the branched structure include 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2,2,4-trimethyl-1,3-pentanediol, 2,4-diethyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, neopentyl glycol, trimethylolpropane, and the like. These compounds may be used individually or in combination of two or more. Among these, neopentyl glycol is preferred.

[0040] In addition to those mentioned above, other compounds having two or more hydroxyl groups include, for example, ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, trimethylolpropane, trimethylolethane, glycerin, and the like. These compounds may be used individually or in combination of two or more.

[0041] Examples of the polybasic acid that can be used include adipic acid, glutaric acid, pimelic acid, suberic acid, dimer acid, sebacic acid, undecanedicarboxylic acid, hexahydroterephthalic acid, phthalic acid, phthalic anhydride, isophthalic acid, terephthalic acid, and the like.

[0042] The number-average molecular weight of the amorphous polyester polyol (a2) is preferably 500 to 10,000, more preferably 1,000 to 5,000, and even more preferably in the range of 1,000 to 3,000. The number-average molecular weight of the amorphous polyester polyol (a2) is the value measured by gel permeation chromatography (GPC).

[0043] The content of the amorphous polyester polyol (a2) in the polyol (A) can be in the range of 10% to 80% by mass per 100% by mass of polyol (A) in order to obtain even better adhesion, with a range of 30% to 70% by mass being preferred, a range of 40% to 65% by mass being more preferred, and a range of 45% to 60% by mass being even more preferred.

[0044] -Optional polyol component- In addition to those mentioned above, polyol (A) can also be, for example, polyacrylic polyol, polycarbonate polyol, polyether polyol, polybutadiene polyol, etc. These polyols may be used individually or in combination of two or more.

[0045] -Polyol (A)- The total content ratio of crystalline polyester polyol (a1) and amorphous polyester polyol (a2) in the polyol (A) can be in the range of 50% to 100% by mass, with a preference of 60% to 100% by mass, more preferably 70% to 100% by mass, even more preferably 80% to 100% by mass, and particularly preferably 90% to 100% by mass. Furthermore, the blending ratio of crystalline polyester polyol (a1) to amorphous polyester polyol (a2) [(a1) / (a2)] is preferably in the range of 0.5 to 2.5, more preferably 0.6 to 2.0, and even more preferably 0.8 to 1.7. The higher the amount of amorphous component in the polyol (A), the better the adhesive strength, but the reduced initial solidification properties result in poor re-peelability, especially shortly after bonding. On the other hand, the higher the crystalline component content in polyol (A), the better the re-peelability short time after lamination due to initial solidification, but the reduced adhesiveness. Therefore, by setting the total content ratio of crystalline polyester polyol (a1) and amorphous polyester polyol (a2) in polyol (A), and the blending ratio of crystalline polyester polyol (a1) and amorphous polyester polyol (a2) within the aforementioned range, a good balance can be achieved between re-peelability short time after lamination with the substrate (especially substrates treated with activated energy rays) and strong adhesion to the substrate after curing.

[0046] (Polyisocyanate (B)) As the polyisocyanate (B), for example, aromatic polyisocyanates such as polymethylene polyphenyl polyisocyanate, diphenylmethane diisocyanate, carbodiimide-modified diphenylmethane diisocyanate isocyanate, phenylene diisocyanate, tolylene diisocyanate, and naphthalene diisocyanate can be used; and aliphatic or alicyclic polyisocyanates such as hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, xylylene diisocyanate, and tetramethylxylylene diisocyanate can be used. Among these, aromatic polyisocyanates are preferred, and diphenylmethane diisocyanate is more preferred, as they provide even better reactivity and adhesion.

[0047] Regarding the amount of polyisocyanate (B) used, a range of 1% to 25% by mass, and more preferably 5% to 20% by mass, is preferred, based on the total mass (100% by mass) of the raw materials constituting the urethane prepolymer (i), in order to obtain even better adhesion.

[0048] (Urethane prepolymer (i)) The urethane prepolymer (i) is a reaction product obtained by reacting the polyol (A) and the polyisocyanate (B). The urethane prepolymer (i) has isocyanate groups at the polymer ends or within the molecule that can react with moisture present in the air or on the adherend to form a crosslinked structure.

[0049] The method for producing the urethane prepolymer (i) can be a known method, but for example, it can be produced by adding the polyol (A) dropwise to a reaction vessel containing the polyisocyanate (B), then heating the vessel, and reacting under conditions in which the isocyanate groups of the polyisocyanate (B) are in excess of the hydroxyl groups of the polyol (A).

[0050] The isocyanate group content (hereinafter abbreviated as "NCO%") of the urethane prepolymer (i) is preferably in the range of 1% to 5% by mass from the viewpoint of obtaining even better adhesion. The NCO% of the urethane prepolymer (i) is the value measured by potentiometric titration in accordance with JIS K1603-1:2007.

[0051] (Moisture-curing polyurethane hot melt resin composition) The moisture-curing polyurethane hot-melt resin composition comprises the urethane prepolymer (i) as an essential component, but may also contain other additives as needed. Examples of these other additives include antioxidants, tackifiers, plasticizers, stabilizers, fillers, dyes, pigments, fluorescent whitening agents, silane coupling agents, waxes, and the like. These additives may be used individually or in combination of two or more.

[0052] <Cured material layer> The thickness of the cured layer is not particularly limited, but can be in the range of, for example, 5 μm to 500 μm.

[0053] 3. Laminate The laminate of this disclosure comprises at least the above-described substrate and a cured layer of the moisture-curing polyurethane hot-melt resin composition. The laminate of this disclosure may also have a laminated structure in which, for example, the above-described substrate is on one surface of the cured layer of the moisture-curing polyurethane hot-melt resin composition, and an adherend (for example, a sheet such as a decorative film or cosmetic film) is on the other surface.

[0054] 4. Manufacturing method of laminates The method for manufacturing the laminate according to the present disclosure comprises the steps of: irradiating a substrate with active energy rays (hereinafter referred to as step 1); and arranging a precursor layer made of a moisture-curable polyurethane hot-melt resin composition on the active energy ray irradiated surface of the substrate (hereinafter referred to as step 2).

[0055] Step 1 involves irradiating the substrate with active energy rays. In the method for manufacturing a laminate according to the present disclosure, by irradiating the substrate with active energy rays, when formula (1) has a predetermined relationship between the substrate and the moisture-curable polyurethane hot-melt resin composition, it is possible to achieve both the ability to be re-peel off the substrate and the precursor layer in a short time after bonding, and strong adhesion between the substrate and the cured product (cured layer) of the precursor layer. The reason for this is not clear, but the following reason is presumed. That is, when the substrate is irradiated with active energy rays, ozone is generated from oxygen in the atmosphere, and oxygen radicals separated from the ozone are introduced into the main chain of the polymer constituting the treated surface, forming oxygen-containing functional groups. When the precursor layer made of the moisture-curable polyurethane hot-melt resin composition is placed on the ultraviolet-irradiated surface of the substrate, the substrate and the precursor layer are chemically bonded, and further, the precursor layer becomes a cured product layer through moisture curing, which is presumed to improve the adhesion between the substrate and the cured product layer, allowing for strong adhesion.

[0056] The types of active energy rays that can be used are those described above. Of these, ultraviolet light is preferred. Furthermore, the irradiation treatment using active energy rays can be carried out using known methods depending on the type of active energy ray. The active energy ray source is not particularly limited, but examples include electron beams, gamma rays, carbon arc lamps, low-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, xenon lamps, gallium lamps, metal halide lamps, sunlight, LEDs, etc. When the active energy ray is ultraviolet light, the ultraviolet light source is not particularly limited, but high-pressure mercury lamps and the like are preferred.

[0057] Furthermore, the atmosphere during active energy ray irradiation is preferably an oxygen-containing atmosphere, and an air atmosphere is preferred. When ultraviolet light is used as the active energy ray, irradiation may be carried out under an inert gas atmosphere such as nitrogen gas, or under an air atmosphere, in order to efficiently carry out the curing reaction by ultraviolet light.

[0058] The integrated light intensity of the active energy rays can be set as appropriate, but is typically between 50 mJ / cm² and 5000 mJ / cm².2 It can be within the range of 100 mJ / cm², among others. 2 ~3500 mJ / cm 2 A range of 150 mJ / cm² is preferred. 2 ~2500 mJ / cm 2 A range of 200 mJ / cm² is more preferable. 2 ~2000 mJ / cm 2 A range of is even more preferable. By setting the integrated amount of active energy rays within the above range, the substrate surface can be modified to a desired state, and the relationship of formula (1) can be satisfied with the moisture-curing polyurethane hot-melt resin composition in this disclosure.

[0059] When irradiating the substrate with active energy rays, the substrate may or may not be heated.

[0060] The surface free energy of the active energy ray irradiated surface of the substrate is not particularly limited as long as the relationship of formula (1) is satisfied with the moisture-curable polyurethane hot-melt resin composition, but it is preferable that the dispersion term and polarity term of the surface free energy of the substrate are independently within the range described in section "1. Substrate".

[0061] Step 2 involves placing a precursor layer made of a moisture-curable polyurethane hot-melt resin composition on the active energy ray irradiation surface of the substrate.

[0062] A precursor layer consisting of a moisture-curing polyurethane hot-melt resin composition refers to a precursor to the cured product layer of the moisture-curing polyurethane hot-melt resin composition, and is a layer in which curing is not yet complete. The precursor layer may be partially cured if the curing reaction is not yet complete. Examples of the precursor layer include a coating film of a moisture-curing polyurethane hot-melt resin composition, or a layer before aging.

[0063] Methods for arranging a precursor layer made of a moisture-curing polyurethane hot-melt resin composition on the active energy ray irradiation surface of the substrate include, for example, a method of applying the moisture-curing polyurethane hot-melt resin composition to the active energy ray irradiation surface of the substrate to form a coating film (precursor layer), and a method of applying the moisture-curing polyurethane hot-melt resin composition to a coating sheet provided on the surface of a substrate such as a decorative sheet or a decorative sheet to form a coating film (precursor layer), and then laminating the coating film (precursor layer) onto the active energy ray irradiation surface of the substrate. The latter method is preferred among these.

[0064] The aforementioned moisture-curing polyurethane hot-melt resin composition can be melted at 50°C to 130°C and applied to the substrate.

[0065] The method for applying the moisture-curing polyurethane hot-melt resin composition to the substrate is not particularly limited and includes methods using a roll coater, spray coater, T-die coater, knife coater, comma coater, etc.

[0066] The aforementioned moisture-curing polyurethane hot-melt resin composition can be sufficiently cured and a cured product obtained by aging it for 0.5 to 3 days at a temperature of 20 to 80°C and a relative humidity of 50 to 90%.

[0067] When the adherend is a substrate in the laminate of this disclosure, the moisture-curable polyurethane hot melt resin composition can be applied to the active energy ray irradiation surface of the substrate, and the coating film (precursor layer) can be aged under the above conditions to form a cured layer of the moisture-curable polyurethane hot melt resin composition. At this time, the coating film (precursor layer) of the moisture-curable polyurethane hot melt resin composition may be aged with a covering sheet such as a decorative sheet or an ornamental sheet placed on the coating film (precursor layer). This makes it possible to manufacture a laminate of a covering sheet / cured layer of the moisture-curable polyurethane hot melt resin composition / substrate (" / " represents the lamination interface).

[0068] On the other hand, when the adherend is a coating sheet such as a decorative sheet or an ornamental sheet, the moisture-curing polyurethane hot melt resin composition can be applied to the sheet, and the coating film (precursor layer) can be bonded to the active energy ray irradiated surface of the substrate and aged under the above conditions to form a cured layer of the moisture-curing polyurethane hot melt resin composition. This makes it possible to manufacture a laminate of a coating sheet / cured layer of the moisture-curing polyurethane hot melt resin composition / substrate (" / " represents the lamination interface).

[0069] Preferably, the laminate of the present disclosure allows for interfacial delamination between the substrate and the precursor layer made of a moisture-curing polyurethane hot-melt resin composition 5 minutes after bonding the substrate and the precursor layer. Interfacial delamination after 5 minutes allows for interfacial delamination between the substrate and the precursor layer even after 5 minutes or more have passed since bonding. The laminate of the present disclosure having the above characteristics allows for good re-peelability without leaving any moisture-curing polyurethane hot-melt resin composition on the substrate side in a short time after bonding the sheet to the substrate via the precursor layer made of a moisture-curing polyurethane hot-melt resin composition, thus enabling re-bonding to the substrate during the manufacturing of the laminate.

[0070] II. Parts Set The parts set of this disclosure comprises a base material and a sheet having an adhesive layer, and is used by bonding the first surface of the base material and the surface of the adhesive layer of the sheet. In the parts set of this disclosure, the adhesive layer is formed of a moisture-curing polyurethane hot melt resin composition, and the moisture-curing polyurethane hot melt resin composition contains a urethane prepolymer (i) having isocyanate groups, and the urethane prepolymer (i) is made from a polyol (A) with crystalline polyester polyol (a1) and amorphous polyester polyol (a2) as essential components, and polyisocyanate (B), and has an α value represented by the following formula (1) in the range of 8.0 to 11.0. α = [δp] ÷ [γCPES] …(1) (The wording in formula (1) above refers to the following: δp: Polarity term of the surface free energy of the substrate. γCPES: The proportion of the crystalline polyester polyol (a1) in the total mass of the raw materials constituting the urethane prepolymer (i).

[0071] According to the parts set of this disclosure, it is possible to manufacture the laminate described in section "I. Laminate" by bonding the substrate and the adhesive layer on the sheet. Furthermore, according to the parts set of this disclosure, when the substrate and the sheet are bonded via the adhesive layer, excellent re-peelability is achieved in a short time after bonding, so if misalignment occurs, the bonding can be reapplied, thereby improving bonding accuracy. In addition, when the substrate and the adhesive layer on the sheet are bonded and cured, the interlayer adhesion between the substrate and the sheet is increased, allowing for a strong bond.

[0072] The preferred range of the α value represented by formula (1) in the component set of this disclosure, as well as the details of the substrate and moisture-curing polyurethane hot-melt resin composition constituting the component set, are the same as those already described in section "I. Laminates," and therefore will not be described here. Furthermore, the "adhesive layer" in the parts set of this disclosure is the pre-curing form of the cured material layer described in section "I. Laminate" (i.e., the precursor layer described in section "I. Laminate").

[0073] In the component set of this disclosure, the first surface of the substrate is preferably treated with active energy rays. That is, the first surface of the substrate is preferably an active energy ray treated surface. Details of the substrate in the component set of this disclosure are the same as those already described in section "I. Laminates" above, and therefore will not be described here.

[0074] In the component set of this disclosure, it is preferable that the interlayer adhesion between the substrate and the cured layer is 40 N / inch or more. The reason for this and the more preferable range of the interlayer adhesion are the same as those already explained in section "I. Laminates" above, and therefore will not be explained here.

[0075] The component set of this disclosure is preferably capable of interfacial delamination between the adhesive layer and the substrate five minutes after bonding the adhesive layer and the substrate. The reason for this and the preferred range of time for delamination after bonding the adhesive layer and the substrate are the same as those already explained in section "I. Laminates," and therefore will not be explained here.

[0076] This disclosure is not limited to the embodiments described above. The embodiments are illustrative, and any configuration that is substantially identical to the technical idea described in the claims of this disclosure and achieves similar effects is included within the technical scope of this disclosure. [Examples]

[0077] The present invention will be described in more detail below with reference to examples.

[0078] [Synthesis Examples 1-9] In a four-necked flask equipped with a thermometer, stirrer, inert gas inlet, and reflux condenser, each polyol raw material shown in Table 1 was charged in the amount (parts by mass) indicated in the same table, and dehydrated by heating under reduced pressure at 90°C until the moisture content was 0.05% by mass or less. Next, after cooling the temperature in the reaction vessel to 60°C, 4,4'-diphenylmethane diisocyanate was added in the amount (parts by mass) shown in Table 1, and the temperature was raised to 110°C. The reaction was carried out for about 3 hours until the isocyanate group content became constant, thereby preparing urethane prepolymers (i-1) to (i-8) having isocyanate groups, and moisture-curing polyurethane hot-melt resin compositions (1) to (9) were obtained.

[0079] [Table 1]

[0080] The abbreviations in Table 1 refer to the following: Amorphous PEs1: An amorphous polyester polyol obtained by reacting diethylene glycol, neopentyl glycol, 1,6-hexanediol, and adipic acid, with a number-average molecular weight of 2,000. Amorphous PEs2: An amorphous polyester polyol obtained by reacting diethylene glycol, neopentyl glycol, 1,6-hexanediol, and adipic acid, with a number-average molecular weight of 7,000. Amorphous PEs3; an amorphous polyester polyol obtained by reacting ethylene glycol, adipic acid, phthalic acid, and terephthalic acid, with a number-average molecular weight of 3,500. Crystalline polyester polyol obtained by reacting crystalline PEs1:1,6-hexanediol and adipic acid, number average molecular weight 4,500 Crystalline polyester polyol obtained by reacting crystalline PEs2:1,6-hexanediol and dodecanediic acid, number average molecular weight 3,500 • Crystalline PEs3: A crystalline polycaprolactone polyol obtained by polymerizing caprolactone, with a number-average molecular weight of 80,000. MDI: 4,4'-diphenylmethane diisocyanate

[0081] (Method for measuring number-average molecular weight) The number-average molecular weight is the value measured by gel permeation chromatography (GPC) under the following conditions.

[0082] Measurement device: High-speed GPC device (HLC-8220GPC manufactured by Tosoh Corporation) Columns: The following columns manufactured by Tosoh Corporation were used, connected in series. "TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 "TSKgel G2000" (7.8mmI.D. x 30cm) x 1 Detector: RI (Differential Refractometer) Column temperature: 40℃ Eluent: Tetrahydrofuran (THF) Flow rate: 1.0mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass) Standard samples: Calibration curves were prepared using the following standard polystyrene samples.

[0083] (Standard polystyrene) TSKgel Standard Polystyrene A-500, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-1000, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-2500, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene A-5000, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-1, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-2, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-4, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-10, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-20, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-40, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-80, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-128, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-288, manufactured by Tosoh Corporation. TSKgel Standard Polystyrene F-550, manufactured by Tosoh Corporation.

[0084] [Example 1] Using a GS Yuasa CSOT-40-4 UV irradiation device (light source: 4kW high-pressure mercury lamp), the cumulative light intensity was 1000 mJ / cm². 2 The aluminum substrate was irradiated with UV light in such a manner. The dispersion term in the surface free energy of the aluminum substrate after UV light irradiation was 33.0 mJ / m2 The polarity term is 4.3 mJ / m 2 That was the case.

[0085] Next, the moisture-curing polyurethane hot melt resin composition (1) was heated and melted at 120°C for 1 hour, and then coated onto a 40 mm wide decorative sheet to a thickness of 0.1 mm using an applicator. The coating film (precursor layer) of the moisture-curing polyurethane hot melt resin composition provided on the decorative sheet was then bonded to the UV light irradiation surface of the aluminum substrate using a press roll to create a laminate of aluminum substrate / coating film (precursor layer) of moisture-curing polyurethane hot melt resin composition / decorative sheet (" / " represents the lamination interface).

[0086] [Examples 2-5] A laminate was obtained in the same manner as in Example 1, except that the moisture-curing polyurethane hot-melt resin composition (1) was replaced with the moisture-curing polyurethane hot-melt resin composition listed in Table 2.

[0087] [Example 6] The cumulative light intensity is 250 mJ / cm². 2 A laminate was obtained in the same manner as in Example 1, except for the aforementioned difference.

[0088] [Comparative Examples 1-2] A laminate was obtained in the same manner as in Example 1, except that the moisture-curing polyurethane hot-melt resin composition (1) was replaced with the moisture-curing polyurethane hot-melt resin composition listed in Table 3.

[0089] [Comparative Example 3] A laminate was obtained in the same manner as in Example 2, except that the aluminum substrate was not irradiated with UV light. The dispersion term in the surface free energy of the aluminum substrate was 36.4 mJ / m 2 The polarity term is 4.3 mJ / m 2 That was the case.

[0090] [Comparative Example 4] A laminate was obtained in the same manner as in Example 1, except that the aluminum substrate was not irradiated with UV light. The dispersion term in the surface free energy of the aluminum substrate was 36.4 mJ / m2 The polarity term is 4.3 mJ / m 2 That was the case.

[0091] [Comparative Example 5] A laminate was obtained in the same manner as in Example 5, except that the aluminum substrate was not irradiated with UV light. The dispersion term in the surface free energy of the aluminum substrate was 36.4 mJ / m 2 The polarity term is 4.3 mJ / m 2 That was the case.

[0092] [evaluation] The following evaluations were performed on the obtained laminate. The results are shown in the table.

[0093] <The alpha value represented by equation (1)> The α value represented by the following formula (1) was determined from the substrate used in the laminate and the moisture-curing polyurethane hot-melt resin composition. α = [δp] ÷ [γ CPES ] …(1) (The wording in formula (1) above refers to the following: δp: Polarity term of the surface free energy of the substrate. γ CPES : The proportion of the crystalline polyester polyol (a1) in the total mass of the raw materials constituting the urethane prepolymer (i).

[0094] The surface free energy (polarity term and dispersion term) of the substrate was calculated by measuring the contact angle of the measurement solution (water and diiodomethane) on the substrate using a contact angle meter (PCA-11, manufactured by Kyowa Interface Science Co., Ltd.). Based on this result, the surface free energy, polarity term, and dispersion term of the substrate were calculated using the following equation (2). The calculation was performed using the Owens-Wendt method with software "FAMAS" (manufactured by Kyowa Interface Science Co., Ltd.). (δdL+δpL)·(1+cosθ) / 2=(δd·δdL)1 / 2+(δp·δpL)1 / 2 …(2) (The signs in equation (2) above are as follows: δd: Dispersion term of the surface free energy of the substrate δp: Polarity term of the surface free energy of the substrate δdL: Dispersion term of the surface free energy of the measured solution δpL: Polarity term of the surface free energy of the measured solution δdL of water: 21.8 mJm -2 δpL: 51.0 mJm -2 Diiodomethane δdL: 49.5 mJm -2 δpL: 1.3mJm -2 )

[0095] <Adhesion (interlayer adhesive strength)> In the aforementioned "Method for Manufacturing a Laminate," a coating film (precursor layer) of a moisture-curing polyurethane hot-melt resin composition provided on a sheet was bonded to an aluminum substrate. After curing at 23°C and 50% humidity for 48 hours to form a cured coating film (cured layer), the sheet was cut to a width of 25 mm. Using a Shimadzu Autograph AGS-X manufactured by Shimadzu Corporation, the 180° peel strength was measured at a peeling speed of 50 mm / min and evaluated according to the following criteria. (standard) ○: Peel strength of 40 N / inch or more ×: Peel strength less than 40 N / inch

[0096] <Removability 1 (5 minutes)> In the "Method for Manufacturing a Laminate" described above, a coating film (precursor layer) of a moisture-curing polyurethane hot-melt resin composition provided on a sheet was bonded to an aluminum substrate, and the sheet was peeled off by hand 5 minutes later. At this time, interfacial delamination between the coating film and the aluminum substrate was evaluated as "○", and material failure of the coating film (precursor layer) occurred, leaving the coating film (precursor layer) on the aluminum substrate side was evaluated as "×".

[0097] <Removability 2 (15 minutes)> In the "Method for Manufacturing a Laminate" described above, a coating film (precursor layer) of a moisture-curing polyurethane hot-melt resin composition provided on a sheet was bonded to an aluminum substrate, and 15 minutes later the sheet was peeled off by hand. Interfacial delamination between the coating film and the aluminum substrate was evaluated as "○", while partial or complete retention of the coating film on the aluminum substrate side was evaluated as "×".

[0098] [Table 2]

[0099] [Table 3]

Claims

1. The material comprises a substrate treated with active energy rays and a cured layer of a moisture-curing polyurethane hot-melt resin composition. The moisture-curing polyurethane hot-melt resin composition contains a urethane prepolymer (i) having an isocyanate group, The urethane prepolymer (i) is made from a polyol (A) which has crystalline polyester polyol (a1) and amorphous polyester polyol (a2) as essential components, and a polyisocyanate (B) as raw materials. A laminate in which the α value represented by the following formula (1) is in the range of 8.0 to 11.

0. α=[δp]÷[γCPES]…(1) (The words in formula (1) above are as follows: δp: Polarity term of the surface free energy of the substrate. γCPES: The percentage of crystalline polyester polyol (a1) in the total mass of the raw materials constituting the urethane prepolymer (i).

2. The material comprises a base material and a cured layer of a moisture-curing polyurethane hot melt resin composition. The moisture-curing polyurethane hot-melt resin composition contains a urethane prepolymer (i) having an isocyanate group, The urethane prepolymer (i) is made from a polyol (A) which has crystalline polyester polyol (a1) and amorphous polyester polyol (a2) as essential components, and a polyisocyanate (B) as raw materials. The interlayer adhesive strength between the substrate and the cured layer is 40 N / inch or more. A laminate in which the α value represented by the following formula (1) is in the range of 8 to 11. α=[δp]÷[γCPES]…(1) (The words in formula (1) above are as follows: δp: Polarity term of the surface free energy of the substrate. γCPES: The percentage of crystalline polyester polyol (a1) in the total mass of the raw materials constituting the urethane prepolymer (i).

3. The laminate according to claim 1 or 2, wherein the content of the crystalline polyester polyol (a1) is in the range of 15% to 80% by mass in 100% by mass of polyol (A).

4. The laminate according to claim 1 or 2, wherein the content of the amorphous polyester polyol (a2) is in the range of 10% to 80% by mass in 100% by mass of polyol (A).

5. The laminate according to claim 1 or 2, wherein the blending ratio [(a1) / (a2)] of the crystalline polyester polyol (a1) and the amorphous polyester polyol (a2) is in the range of 0.8 to 1.

7.

6. The laminate according to claim 1, wherein the base material is an aluminum base material.

7. A method for manufacturing a laminate according to any one of claims 1 to 6, A process of irradiating the substrate with active energy rays, The process involves placing a precursor layer made of a moisture-curable polyurethane hot-melt resin composition on the active energy ray irradiation surface of the substrate, A method for manufacturing a laminate having the following characteristics.

8. A method for manufacturing a laminate according to claim 7, wherein the substrate and the precursor layer are bonded together, and after 5 minutes, the interface between the substrate and the precursor layer can be peeled off.

9. A component set comprising a base material and a sheet having an adhesive layer, wherein the first surface of the base material and the surface of the adhesive layer of the sheet are bonded together, The adhesive layer is formed from a moisture-curing polyurethane hot-melt resin composition. The moisture-curing polyurethane hot-melt resin composition contains a urethane prepolymer (i) having an isocyanate group, The urethane prepolymer (i) is made from a polyol (A) which has crystalline polyester polyol (a1) and amorphous polyester polyol (a2) as essential components, and a polyisocyanate (B) as raw materials. A parts set in which the α value represented by the following formula (1) is in the range of 8.0 to 11.

0. α=[δp]÷[γCPES]…(1) (The words in formula (1) above are as follows: δp: Polarity term of the surface free energy of the substrate. γCPES: The percentage of crystalline polyester polyol (a1) in the total mass of the raw materials constituting the urethane prepolymer (i).

10. The component set according to claim 9, wherein the first surface of the substrate is treated with active energy rays.

11. The parts set according to claim 9, wherein the interlayer adhesive strength between the substrate and the cured product layer is 40 N / inch or more.

12. The parts set according to claim 9, wherein the adhesive layer and the substrate are bonded together, and after 5 minutes, the interface between the adhesive layer and the substrate can be peeled off.

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