Laminate containing an adhesive layer, adhesive composition and method for manufacturing the same.

Abstract

The present invention provides a laminate comprising an adhesive layer that can contribute to reducing the amount of petroleum resources used and expand the range of physical properties of the adhesive, as well as an adhesive composition and a method for manufacturing the same. [Solution] A laminate according to one embodiment of the present disclosure comprises a first copolymer containing structural units derived from a carboxyl group-containing monomer, a second copolymer containing structural units derived from an amino group-containing monomer, an adhesive layer containing a cured product of a crosslinking agent, and a substrate, wherein the first copolymer has a weight-average molecular weight of about 800,000 or less and a glass transition temperature of less than about 0°C, and the second copolymer has a weight-average molecular weight of about 30,000 or more and about 100,000 or less and a glass transition temperature of about 0°C or more, and at least one of the first copolymer and the second copolymer contains structural units derived from a (meth)acrylate monomer containing carbon atoms of biological origin.

Description

[Technical Field]

[0001] This disclosure relates to laminates including an adhesive layer, as well as adhesive compositions and methods for producing the same. [Background technology]

[0002] In recent years, laminates such as adhesive tapes have been developed that feature an adhesive layer formed using bio-derived materials instead of petroleum-derived materials.

[0003] Patent Document 1 (JP 2012-514083) describes an adhesive article in which the adhesive comprises a reaction product of (a) at least one polymerizable (meth)acrylate monomer derived at least in part from palm oil, coconut oil, animal fat or lard, (b) a reaction initiator, and (c) a stabilizer, wherein the reaction occurs in water to produce microsphere adhesive, and the adhesive is placed on a polymer film or the like.

[0004] Patent Document 2 (Japanese Patent Publication No. 2019-218458) describes an adhesive tape having an adhesive layer containing a (meth)acrylic copolymer containing constituent units derived from a (meth)acrylic monomer containing bio-derived carbon, wherein the bio-derived carbon content of the adhesive tape is 30% by weight or more. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Special Publication No. 2012-514083 [Patent Document 2] Japanese Patent Publication No. 2019-218458 [Overview of the project] [Problems that the invention aims to solve]

[0006] As described in Patent Documents 1 and 2, adhesives formed using bio-derived materials generally contain only one type of copolymer formed using bio-derived materials. Therefore, it has sometimes been difficult to adjust the physical properties of such adhesives to a desired range.

[0007] This disclosure provides a laminate comprising an adhesive layer that can contribute to reducing the amount of petroleum resources used and can broaden the range of physical properties of the adhesive, as well as an adhesive composition and a method for manufacturing the same. [Means for solving the problem]

[0008] According to one embodiment of the present disclosure, a laminate is provided comprising a first copolymer containing structural units derived from a carboxyl group-containing monomer, a second copolymer containing structural units derived from an amino group-containing monomer, an adhesive layer containing a cured product of a crosslinking agent, and a substrate, wherein the first copolymer has a weight-average molecular weight of about 800,000 or less and a glass transition temperature of less than about 0°C, and the second copolymer has a weight-average molecular weight of about 30,000 or more and about 100,000 or less and a glass transition temperature of about 0°C or more, and at least one of the first copolymer and the second copolymer contains structural units derived from a (meth)acrylate monomer containing carbon atoms of biological origin.

[0009] According to another embodiment of the present disclosure, an adhesive composition is provided comprising a first copolymer containing structural units derived from a carboxyl group-containing monomer, a second copolymer containing structural units derived from an amino group-containing monomer, and a crosslinking agent, wherein the first copolymer has a weight-average molecular weight of about 800,000 or less and a glass transition temperature of less than about 0°C, and the second copolymer has a weight-average molecular weight of about 30,000 or more and about 100,000 or less and a glass transition temperature of about 0°C or more, and at least one of the first copolymer and the second copolymer contains structural units derived from a (meth)acrylate monomer containing carbon atoms of biological origin.

[0010] According to another embodiment of the present disclosure, there is provided a method for producing the above adhesive composition, the method comprising mixing a first copolymer, a second copolymer, and a crosslinking agent.

[0011] According to another embodiment of the present disclosure, there is provided a method for producing the above adhesive composition containing a pigment, the method comprising preparing a pigment mixture by mixing at least one selected from the group consisting of a second copolymer and a third copolymer containing a structural unit derived from an amide group-containing monomer and a pigment, and mixing the pigment mixture with a mixture containing a first copolymer and a crosslinking agent, or preparing a pigment mixture by mixing at least one selected from the group consisting of a second copolymer and a third copolymer containing a structural unit derived from an amide group-containing monomer, a crosslinking agent, and a pigment, and mixing the pigment mixture with a first copolymer.

Advantages of the Invention

[0012] According to the present disclosure, it is possible to provide a laminate including an adhesive layer that can contribute to reducing the usage amount of petroleum resources and can expand the physical property range of the adhesive, as well as an adhesive composition and a method for producing the same.

[0013] The above description should not be regarded as disclosing all embodiments of the present invention and all advantages related to the present invention.

Brief Description of the Drawings

[0014] [Figure 1] It is a schematic cross-sectional view of a laminate according to an embodiment of the present disclosure.

Modes for Carrying Out the Invention

[0015] Hereinafter, for the purpose of exemplifying representative embodiments of the present invention, a more detailed description will be given with reference to the drawings as necessary, but the present invention is not limited to these embodiments.

[0016] In the present disclosure, for example, the term "above" in the phrase "an adhesive layer disposed above the release liner" means that the adhesive layer is directly disposed above the release liner, or the adhesive layer is indirectly disposed above the release liner through another layer.

[0017] In the present disclosure, for example, the term "below" in the phrase "an adhesive layer disposed below the substrate" means that the adhesive layer is directly disposed below the substrate, or the adhesive layer is indirectly disposed below the substrate through another layer.

[0018] In the present disclosure, "transparent" means that the average transmittance in the visible light region (wavelength 400 nm to 700 nm) measured in accordance with JIS K 7375 is about 80% or more, desirably about 85% or more, or about 90% or more. There is no particular limitation on the upper limit value of the average transmittance, but for example, it can be less than about 100%, about 99% or less, or about 98% or less.

[0019] In the present disclosure, "translucent" means that the average transmittance in the visible light region (wavelength 400 nm to 700 nm) measured in accordance with JIS K 7375 is less than about 80%, desirably about 75% or less, and is intended not to completely conceal the base or the like.

[0020] In the present disclosure, "film" includes a member called "sheet".

[0021] In the present disclosure, "(meth)acryl" means acrylic or methacrylic, "(meth)acrylate" means acrylate or methacrylate, and "(meth)acryloyl" means acryloyl or methacryloyl.

[0022] Figure 1 shows a schematic cross-sectional view of a laminate according to one embodiment of the present disclosure. The laminate 100 in Figure 1 includes a base material 10, an adhesive layer 20, and a release liner 30. Here, the release liner shown in Figure 1 is an arbitrary layer, and the laminate of the present disclosure does not have to include a release liner. In addition, the laminate of the present disclosure may include an arbitrary layer (e.g., a decorative layer) as described later.

[0023] The adhesive strength of the laminates of this disclosure can be evaluated by an adhesive strength test described later. In some embodiments, when a melamine-coated board is used as the substrate to which the adhesive layer of the laminate of this disclosure is applied, it can exhibit an adhesive strength of approximately 5.0 N / 25 mm or more, approximately 6.0 N / 25 mm or more, approximately 7.0 N / 25 mm or more, or approximately 8.0 N / 25 mm or more at room temperature. The upper limit of such adhesive strength can be, for example, approximately 40.0 N / 25 mm or less, approximately 35.0 N / 25 mm or less, approximately 30.0 N / 25 mm or less, approximately 25.0 N / 25 mm or less, approximately 20.0 N / 25 mm or less, approximately 19.0 N / 25 mm or less, approximately 18.5 N / 25 mm or less, or approximately 18.0 N / 25 mm or less. Herein, in this disclosure, "room temperature" means the temperature inside the room in which the test is conducted, and specifically, for example, it may mean approximately 23°C ± approximately 5°C or approximately 23°C ± approximately 3°C.

[0024] In some embodiments, the laminate of the present disclosure can exhibit an adhesive strength of approximately 5.0 N / 25 mm or more, approximately 6.0 N / 25 mm or more, approximately 6.5 N / 25 mm or more, or approximately 7.0 N / 25 mm or more at room temperature when an aluminum plate is used as the substrate to which the adhesive layer is applied. The upper limit of such adhesive strength can be, for example, approximately 40.0 N / 25 mm or less, approximately 35.0 N / 25 mm or less, approximately 30.0 N / 25 mm or less, approximately 25.0 N / 25 mm or less, approximately 24.0 N / 25 mm or less, approximately 23.5 N / 25 mm or less, or approximately 23.0 N / 25 mm or less.

[0025] In some embodiments, the laminates of the present disclosure exhibit heat resistance. Such heat resistance can be evaluated by a heat shrinkage test described later. In some embodiments, the laminates of the present disclosure can achieve a maximum gap width (opening) of approximately 0.50 mm or less, approximately 0.40 mm or less, approximately 0.30 mm or less, or approximately 0.25 mm or less after a heat shrinkage test. There is no particular limit to the lower limit of such a width; for example, it can be approximately 0 mm or more.

[0026] The adhesive layer of the present disclosure may contain a pigment, and as a result, the resulting laminate may exhibit opacity. Opacity can be evaluated by the color difference in the opacity test described later. In some embodiments, the laminate of the present disclosure exhibits a color difference of less than about 12, less than or equal to about 10, less than or equal to about 8.0, less than or equal to about 6.0, less than or equal to about 5.0, or less than or equal to about 4.0. There is no particular limit to the lower limit of such color difference, and it may be, for example, about 0 or greater than or equal to about 0.

[0027] In some embodiments, the laminates of the present disclosure exhibit elongation properties. Such elongation properties can be evaluated by yield strength tests, elongation tests, and tensile strength tests, as described later. In some embodiments, the laminates of the present disclosure can exhibit yield strengths of approximately 10 N / 25 mm or more, approximately 15 N / 25 mm or more, or approximately 20 N / 25 mm or more, approximately 70 N / 25 mm or less, approximately 65 N / 25 mm or less, approximately 60 N / 25 mm or less, approximately 55 N / 25 mm or less, or approximately 50 N / 25 mm or less, and approximately 20% or more, approximately 25% or more, approximately 30% or more, approximately 40% or more, approximately 50% or more, approximately 60% or more, and approximately 7 It can exhibit an elongation of 0% or more, approximately 80% or more, or approximately 90% or more, approximately 160% or less, approximately 150% or less, approximately 140% or less, approximately 130% or less, or approximately 125% or less, and can exhibit a 2% tensile strength of approximately 5N / 25mm or more, approximately 10N / 25mm or more, or approximately 15N / 25mm or more, approximately 50N / 25mm or less, approximately 40N / 25mm or less, approximately 30N / 25mm or less, or approximately 25N / 25mm or less.

[0028] In some embodiments, the laminates of the present disclosure exhibit conformability and, as a result, gloss retention performance. Such gloss retention performance can be evaluated by the gloss retention rate described later. In some embodiments, the laminates of the present disclosure may exhibit gloss retention rates of less than about 200%, about 150% or less, about 130% or less, or about 120% or less. There is no particular limit to the lower limit of such retention rates, and for example, it can be about 50% or more, about 80% or more, or about 100% or more.

[0029] The laminate of this disclosure includes an adhesive layer containing a cured product of a first copolymer, a second copolymer, and a crosslinking agent. Since these copolymers are polymers that can be further crosslinked with the crosslinking agent, the first copolymer and the second copolymer before crosslinking with the crosslinking agent can also be referred to as the "first partial polymer" and the "second partial polymer," respectively. In this disclosure, "cured product" is not limited to a crosslinked product in which the crosslinking reactive sites in the first copolymer and / or the second copolymer have completely undergone the crosslinking reaction, but may also include a crosslinked product in which some of the crosslinking reactive sites remain uncrosslinked.

[0030] The first copolymer constituting the adhesive layer contains constituent units derived from carboxyl group-containing monomers, has a weight-average molecular weight of approximately 800,000 or less, and a glass transition temperature of approximately 0°C or less.

[0031] The weight-average molecular weight of the first copolymer can be approximately 700,000 or less, approximately 600,000 or less, approximately 500,000 or less, approximately 450,000 or less, approximately 430,000 or less, approximately 400,000 or less, approximately 380,000 or less, or approximately 350,000 or less, and can be approximately 100,000 or more, approximately 150,000 or more, approximately 200,000 or more, or approximately 210,000 or more. The "weight-average molecular weight" and the "molecular weight distribution" expressed as weight-average molecular weight (Mw) / number-average molecular weight (Mn) in this disclosure can be measured by GPC (gel permeation chromatography). For example, the following conditions can be used as measurement conditions: Equipment: HP-1090 Series II (manufactured by Hewlett-Packard) Solvent: tetrahydrofuran Column: Plgel MIXED-Bx2 (300mm, outer diameter 7.5mm, inner diameter 5mm) Flow rate: 1.0 mL / min Detection means: refractive index Sample concentration: 0.1 wt% Calibration standard: Polystyrene

[0032] In some embodiments, the molecular weight distribution of the first copolymer is about 10 or less. Such molecular weight distribution can be about 8.0 or less, about 7.0 or less, about 6.0 or less, or about 5.0 or less. There is no particular limit to the lower limit of the molecular weight distribution, and it can be about 0 or more, about 1.0 or more, about 2.0 or more, or about 3.0 or more. Using a first copolymer with such a narrow molecular weight distribution can increase the solid content of the adhesive composition and reduce the viscosity of the adhesive. Using an adhesive composition with high solid content can, for example, reduce the energy required to dry the adhesive layer, and as a result, can make a favorable contribution to environmental issues. Furthermore, using a first copolymer with a narrow molecular weight distribution can reduce the proportion of low molecular weight copolymers that cause a decrease in adhesive strength, thus improving performance such as adhesive strength compared to adhesive layers prepared using copolymers with a broad molecular weight distribution.

[0033] The glass transition temperature of the first copolymer can be approximately -5°C or lower, approximately -10°C or lower, approximately -20°C or lower, approximately -30°C or lower, approximately -40°C or lower, approximately -43°C or lower, approximately -45°C or lower, approximately -47°C or lower, or approximately -50°C or lower, and can be approximately -100°C or higher, approximately -80°C or higher, approximately -70°C or higher, approximately -65°C or higher, or approximately -60°C or higher. The "glass transition temperature (Tg)" in this disclosure can be determined as the glass transition temperature calculated using the following FOX formula (Fox, TG, Bull. Am. Phys. Soc., 1 (1956), p. 123), assuming that each polymer is copolymerized from n types of monomers:

number

number

[0034] A first copolymer containing constituent units derived from a carboxyl group-containing monomer can be obtained by copolymerizing a monoethylene unsaturated monomer with a carboxyl group-containing unsaturated monomer.

[0035] Monoethylenically unsaturated monomers are generally represented by the formula CH2=CR 1 COOR 2 (R in the formula 1 R is a hydrogen or methyl group, 2 In addition to (meth)acrylates represented by the formula CH2=CR (where CH2 is a linear, branched, or cyclic alkyl group, phenyl group, alkoxyalkyl group, phenoxyalkyl group, hydroxyalkyl group, or cyclic ether group), the formula also includes aromatic vinyl monomers such as styrene, α-methylstyrene, and vinyltoluene, vinyl esters such as vinyl acetate, and unsaturated nitriles such as acrylonitrile and methacrylonitrile. 1 COOR 2Examples of monoethylene unsaturated monomers represented by include linear alkyl(meth)acrylates such as methyl(meth)acrylate, ethyl(meth)acrylate, n-butyl(meth)acrylate, n-hexyl(meth)acrylate, n-decyl(meth)acrylate, and n-dodecyl(meth)acrylate; branched alkyl(meth)acrylates such as isoamyl(meth)acrylate, 2-ethylhexyl(meth)acrylate, isooctyl(meth)acrylate, and isononyl(meth)acrylate; and alicyclic(meth)acrylates such as cyclohexyl(meth)acrylate and isobornyl(meth)acrylate. Examples include phenyl (meth)acrylate; alkoxyalkyl (meth)acrylates such as methoxypropyl (meth)acrylate and 2-methoxybutyl (meth)acrylate; phenoxyalkyl (meth)acrylates such as phenoxyethyl (meth)acrylate; hydroxyalkyl (meth)acrylates such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, and 4-hydroxybutyl (meth)acrylate; and cyclic ether-containing (meth)acrylates such as glycidyl (meth)acrylate and tetrahydrofurfuryl (meth)acrylate. Among these, n-butyl (meth)acrylate is preferred from the viewpoint of compatibility with the second copolymer described later, adhesive strength, and heat shrinkage resistance. Monoethylene unsaturated monomers can be used alone or in combination of two or more.

[0036] As the monoethylene unsaturated monomer, a (meth)acrylate monomer containing bio-derived carbon atoms may be used. The (meth)acrylate monomer containing bio-derived carbon atoms can be used alone or in combination of two or more types. The inventors have found that by employing a specific first copolymer and a specific second copolymer described later, even if at least one of them contains constituent units derived from a (meth)acrylate monomer containing bio-derived carbon atoms, it is possible to achieve performance equivalent to that of an adhesive similarly prepared using conventional petroleum-derived materials. From the viewpoint of adhesive strength, heat shrinkage resistance, etc., the first copolymer preferably contains constituent units derived from a (meth)acrylate monomer containing bio-derived carbon atoms (hereinafter sometimes referred to as "bio-derived constituent units"), and more preferably, in addition to such bio-derived constituent units, it also contains constituent units derived from the above-mentioned monoethylene unsaturated monomer other than the bio-derived constituent units, i.e., it is a copolymer of three or more types (for example, a ternary copolymer). If the first copolymer also contains constituent units derived from the monoethylene unsaturated monomers described above, in addition to the biologically derived constituent units, it is possible to adjust the properties such as compatibility with the second copolymer and, if present, the third copolymer, as described later. As a result, it becomes easier to achieve the desired physical properties in the adhesive layer, and the adhesion to the substrate can also be improved. From the viewpoint of improving the properties such as compatibility with the second copolymer and, if present, the third copolymer, it is preferable that the first copolymer contains the same or similar constituent units as the constituent units derived from the monoethylene unsaturated monomers that constitute the second copolymer and / or the third copolymer. In this disclosure, "same constituent units" may refer to constituent units composed of monomers having the same main skeleton, such as n-butyl acrylate and n-butyl methacrylate.

[0037] While bio-derived carbon atoms contain a certain percentage of the radioactive isotope C-14, petroleum-derived carbon atoms contain almost no C-14. Therefore, the content of bio-derived carbon atoms can be calculated by measuring the concentration of C-14 contained in the laminate or adhesive composition. Specifically, this can be measured in accordance with ASTM D6866, a standard used in the bioplastics industry.

[0038] As (meth)acrylate monomers containing carbon atoms of biological origin, plant-derived (meth)acrylate monomers containing carbon atoms are preferred from the viewpoint of adhesive strength, heat shrinkage resistance, etc. Examples of such plants include palm oil and coconut oil. From the viewpoint of adhesive strength, heat shrinkage resistance, etc., (meth)acrylate monomers having alkyl groups with 4 or more, 5 or more, 6 or more, 12 or less, 10 or less, or 8 or less carbon atoms are preferred, and at least one selected from the group consisting of n-octyl (meth)acrylate and 2-octyl (meth)acrylate is more preferred.

[0039] If the first copolymer does not contain biologically derived structural units, the proportion of structural units derived from the monoethylene unsaturated monomers other than the biologically derived structural units can be, for example, about 85% by mass or more, about 90% by mass or more, or about 92% by mass or more, about 99.5% by mass or less, about 99% by mass or less, or about 98% by mass or less, relative to the first copolymer. If the first copolymer contains biologically derived constituent units, the proportion of such constituent units can be, for example, about 40% by mass or more, about 50% by mass or more, about 55% by mass or more, or about 60% by mass or more, about 99.5% by mass or less, about 95% by mass or less, about 90% by mass or less, about 80% by mass or less, about 75% by mass or less, about 70% by mass or less, or about 65% by mass or less, relative to the first copolymer. If present, the proportion of constituent units derived from the above-mentioned monoethylene unsaturated monomers other than the biologically derived constituent units can be, for example, about 10% by mass or more, about 15% by mass or more, about 20% by mass or more, about 25% by mass or more, or about 30% by mass or more, about 50% by mass or less, about 45% by mass or less, about 40% by mass or less, or about 35% by mass or less, relative to the first copolymer.

[0040] Examples of carboxyl group-containing unsaturated monomers include unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid, and crotonic acid; unsaturated dicarboxylic acids such as itaconic acid, fumaric acid, citraconic acid, and maleic acid; ω-carboxypolycaprolactone monoacrylate, monohydroxyethyl (meth)acrylate phthalate, β-carboxyethyl acrylate, 2-(meth)acryloyloxyethyl succinic acid, and 2-(meth)acryloyloxyethyl hexahydrophthalic acid. Carboxyl group-containing unsaturated monomers can be used alone or in combination of two or more.

[0041] The proportion of constituent units derived from carboxyl group-containing unsaturated monomers can be approximately 0.5% by mass or more, approximately 1% by mass or more, or approximately 2% by mass or more, approximately 15% by mass or less, approximately 10% by mass or less, or approximately 8% by mass or less, relative to the first copolymer.

[0042] The second copolymer constituting the adhesive layer contains constituent units derived from amino group-containing monomers, has a weight-average molecular weight of approximately 30,000 to approximately 100,000, and a glass transition temperature of approximately 0°C or higher.

[0043] The weight-average molecular weight of the second copolymer can be approximately 35,000 or more, approximately 40,000 or more, approximately 45,000 or more, approximately 50,000 or more, approximately 55,000 or more, or approximately 60,000 or more, and can be approximately 90,000 or less, approximately 85,000 or less, approximately 80,000 or less, approximately 75,000 or less, or approximately 70,000 or less.

[0044] In some embodiments, the molecular weight distribution of the second copolymer is about 10 or less. Such molecular weight distribution can be about 8.0 or less, about 7.0 or less, about 6.0 or less, or about 5.0 or less. There is no particular limit to the lower limit of the molecular weight distribution, and it can be about 0 or more, about 1.0 or more, about 2.0 or more, or about 3.0 or more. Using a second copolymer with such a narrow molecular weight distribution can increase the solid content of the adhesive composition and reduce the viscosity of the adhesive. Using an adhesive composition with high solid content can, for example, reduce the energy required to dry the adhesive layer, and as a result, can contribute favorably to environmental issues. Furthermore, using a second copolymer with a narrow molecular weight distribution can reduce the proportion of low molecular weight copolymers that cause a decrease in adhesive strength, thus improving performance such as adhesive strength compared to adhesive layers prepared using copolymers with a broad molecular weight distribution.

[0045] The glass transition temperature of the second copolymer can be approximately 10°C or higher, approximately 20°C or higher, approximately 30°C or higher, approximately 40°C or higher, approximately 45°C or higher, approximately 50°C or higher, approximately 55°C or higher, or approximately 60°C or higher, and can be approximately 100°C or lower, approximately 90°C or lower, approximately 80°C or lower, approximately 75°C or lower, approximately 70°C or lower, or approximately 65°C or lower.

[0046] A second copolymer containing constituent units derived from an amino group-containing monomer can be obtained by copolymerizing a monoethylene unsaturated monomer with an amino group-containing unsaturated monomer.

[0047] As monoethylene unsaturated monomers, the monoethylene unsaturated monomers in the first copolymer described above can be used in the same way. Among these, methyl (meth)acrylate and n-butyl (meth)acrylate are preferred from the viewpoint of compatibility with the first copolymer described above, adhesion, and heat shrinkage resistance. Monoethylene unsaturated monomers can be used alone or in combination of two or more. From the viewpoint of improving performance such as compatibility with the first copolymer described above and, if present, the third copolymer, it is preferable that the second copolymer contains the same or the same type of constituent units as those derived from the monoethylene unsaturated monomers constituting the first copolymer and / or the third copolymer.

[0048] In the second copolymer, as in the first copolymer, a (meth)acrylate monomer containing bio-derived carbon atoms may be used. The monomers described above can be used in the same manner.

[0049] If the second copolymer does not contain biologically derived constituent units, the proportion of constituent units derived from monoethylene unsaturated monomers other than biologically derived constituent units can be, for example, about 85% by mass or more, about 90% by mass or more, or about 92% by mass or more, about 99.5% by mass or less, about 99% by mass or less, or about 98% by mass or less, relative to the second copolymer. If the second copolymer contains biologically derived constituent units, the proportion of such constituent units can be, for example, about 40% by mass or more, about 50% by mass or more, about 55% by mass or more, or about 60% by mass or more, about 99.5% by mass or less, about 95% by mass or less, about 90% by mass or less, about 80% by mass or less, about 75% by mass or less, about 70% by mass or less, or about 65% by mass or less, relative to the second copolymer. If present, the proportion of constituent units derived from monoethylene unsaturated monomers other than biologically derived constituent units can be, for example, about 10% by mass or more, about 15% by mass or more, about 20% by mass or more, about 25% by mass or more, or about 30% by mass or more, about 50% by mass or less, about 45% by mass or less, about 40% by mass or less, or about 35% by mass or less, relative to the second copolymer.

[0050] Examples of amino group-containing unsaturated monomers include dialkylaminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl acrylate (DMAEA) and N,N-dimethylaminoethyl methacrylate (DMAEMA); dialkylaminoalkyl (meth)acrylamides such as N,N-dimethylaminopropyl acrylamide (DMAPAA) and N,N-dimethylaminopropyl methacrylamide; dialkylaminoalkyl vinyl ethers such as N,N-dimethylaminoethyl vinyl ether and N,N-diethylaminoethyl vinyl ether; and monomers having tertiary amino groups, such as vinyl monomers having nitrogen-containing heterocycles, such as vinylimidazole. Amino group-containing unsaturated monomers can be used alone or in combination of two or more.

[0051] The proportion of constituent units derived from amino group-containing monomers can be approximately 0.5% by mass or more, approximately 1% by mass or more, or approximately 2% by mass or more, approximately 15% by mass or less, approximately 10% by mass or less, or approximately 8% by mass or less, relative to the second copolymer.

[0052] The first and second copolymers (partial polymers) can be prepared, for example, using radical polymerization, or using known polymerization methods such as solution polymerization, suspension polymerization, emulsion polymerization, and bulk polymerization. As initiators, for example, organic peroxides such as benzoyl peroxide, lauroyl peroxide, and bis(4-tert-butylcyclohexyl) peroxydicarbonate, and azo polymerization initiators such as 2,2'-azobisisobutyronitrile, 2,2'-azobis(2-methylbutyronitrile), dimethyl-2,2'-azobis(2-methylpropionate), 4,4'-azobis(4-cyanovaleric acid), and 2,2'-azobis(2,4-dimethylvaleronitrile) (AVN) can be used. The amount of initiator used can be, for example, about 0.01 parts by mass or more, or about 0.05 parts by mass or more, about 5 parts by mass or less, or about 3 parts by mass or less, per 100 parts by mass of the monomer mixture.

[0053] The adhesive layer of this disclosure can be prepared using an adhesive composition comprising a first and a second copolymer (partial polymer) and a crosslinking agent, for example, a solvent-type, emulsion-type, pressure-sensitive, heat-sensitive, thermosetting, or radiation-curable (e.g., ultraviolet) adhesive composition. By using a composition containing a crosslinking agent, the adhesive layer comprising such copolymers and cured products of the crosslinking agent can have a crosslinked structure. Examples of crosslinking agents include thermal crosslinking agents and radiation crosslinking agents (e.g., ultraviolet crosslinking agents), and specifically, epoxy crosslinking agents, bisamide crosslinking agents, aziridine crosslinking agents, and carbodiimide crosslinking agents can be used. The crosslinking agent can be used alone or in combination of two or more types. The adhesive layer of this disclosure is not particularly limited, and may be, for example, a heat-sensitive adhesive layer or a pressure-sensitive adhesive layer (tack layer). The type of these adhesive layers can be adjusted, for example, by the type or blending ratio of the first copolymer and the second copolymer, or by the type or blending ratio of the crosslinking agent.

[0054] Examples of epoxy crosslinking agents include N,N,N',N'-tetraglycidyl-1,3-benzenedi(methaneamine) (product name TETRAD-X (Mitsubishi Gas Chemical Co., Ltd., Chiyoda-ku, Tokyo, Japan), E-AX, E-5XM (Soken Chemical Co., Ltd., Toshima-ku, Tokyo, Japan)); and N,N'-(cyclohexane-1,3-diylbismethylene)bis(diglycidylamine) (product name TETRAD-C (Mitsubishi Gas Chemical Co., Ltd., Chiyoda-ku, Tokyo, Japan), E-5C (Soken Chemical Co., Ltd., Toshima-ku, Tokyo, Japan)). Examples of bisamide crosslinking agents include 1,1'-(1,3-phenylenedicarbonyl)bis(2-methylaziridine), 1,4-bis(ethyleneiminocarbonylamino)benzene, 4,4'-bis(ethyleneiminocarbonylamino)diphenylmethane, and 1,8-bis(ethyleneiminocarbonylamino)octane. Examples of aziridine crosslinking agents include Chemitite PZ33 (Nippon Shokubai Co., Ltd., Osaka, Japan) and NeoCryl CX-100 (DSM Coating Resins, LLC., Zwolle, Overijssel, Netherlands). Examples of carbodiimide crosslinking agents include Carbodilite V-03, V-05, and V-07 (Nisshinbo Chemical Co., Ltd., Chuo-ku, Tokyo, Japan).

[0055] The amount of crosslinking agent used may be about 0.01 parts by mass or more, about 0.05 parts by mass or more, or about 0.1 parts by mass or more, about 5 parts by mass or less, about 3 parts by mass or less, or about 2 parts by mass or less, per 100 parts by mass of the first copolymer containing constituent units derived from carboxyl group monomers.

[0056] By changing the blending ratio of a first copolymer containing structural units derived from carboxyl group-containing monomers and a second copolymer containing structural units derived from amino group-containing monomers, desired properties (e.g., adhesive strength, heat shrinkage resistance, reworkability, conformability) can be imparted to the laminate. In one embodiment, the blending ratio of the second copolymer is less than about 20 parts by mass, about 15 parts by mass or less, about 10 parts by mass or less, or about 7 parts by mass or less, about 1 part by mass or more, about 2 parts by mass or more, or about 3 parts by mass or more, per 100 parts by mass of the first copolymer. An adhesive layer containing the second copolymer in such proportions can improve properties such as adhesive strength, heat shrinkage resistance, reworkability, and conformability. The first copolymer, with a weight-average molecular weight of about 800,000 or less, has a lower molecular weight and is more wettable than conventionally used copolymers, making it difficult to obtain significant performance in terms of reworkability. However, the inventors have discovered that simply adding a small amount of the second copolymer can change the wettability and unexpectedly improve reworkability.

[0057] The total content of the first copolymer, the second copolymer, and any third copolymer described later in the adhesive layer or adhesive composition (solid content) can be, for example, about 25% by mass or more, about 30% by mass or more, about 35% by mass or more, about 40% by mass or more, about 45% by mass or more, about 50% by mass or more, about 55% by mass or more, or about 60% by mass or more, 100% by mass or less, about 95% by mass or less, about 90% by mass or less, or about 80% by mass or less.

[0058] The adhesive composition for forming the adhesive layer may optionally contain other components, either alone or in combination of two or more, as long as they do not adversely affect the effects of the present disclosure. Examples of such optional components include other resins besides the first and second copolymers described above (e.g., thermoplastic resins, a third copolymer described later), fillers, conductive agents, thermal conductivity imparters, antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, dispersants, plasticizers, lubricants, surfactants, leveling agents, silane coupling agents, catalysts, pigments, dyes, and solvents.

[0059] The adhesive layer of the present disclosure can be obtained by applying an adhesive composition containing, for example, a first and a second copolymer (partial polymer) and a crosslinking agent to a base material or a release liner described later, and then performing a heat treatment and / or a radiation (e.g., ultraviolet ray) irradiation treatment. Here, as the components used in the adhesive composition, the components that can be used in the above-described adhesive layer can be similarly adopted. As described above, the adhesive composition can be, for example, a solvent-based, emulsion-based, pressure-sensitive, heat-sensitive, thermosetting, or radiation (e.g., ultraviolet ray) curable adhesive composition.

[0060] The heat treatment can be carried out using, for example, a heating heater such as an infrared heater, hot air, an oven, etc. The heat treatment can be performed batchwise or continuously using a belt conveyor or the like, but from the viewpoint of productivity and the like, it is preferably performed continuously. The heating temperature (set temperature) can be, for example, about 70°C or higher, about 80°C or higher, or about 90°C or higher. There is no particular limitation on the upper limit value of the heating temperature, and it can be, for example, about 160°C or lower, about 140°C or lower, or about 120°C or lower.

[0061] As the ultraviolet ray irradiation, which is a kind of radiation irradiation, it can be carried out using, for example, a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a xenon lamp, a metal halide lamp, an electrodeless lamp, or a UV-LED as a light source. The ultraviolet ray irradiation can be performed batchwise or continuously using a belt conveyor or the like, but from the viewpoint of productivity and the like, it is preferably performed continuously. The irradiation amount of ultraviolet ray (UV-C) can be, for example, about 1 mJ / cm 2 or more, about 50 mJ / cm 2 or more, or about 100 mJ / cm 2 or more. There is no particular limitation on the upper limit value of the irradiation amount of ultraviolet ray, but it can be, for example, about 500 mJ / cm 2 or less or about 450 mJ / cm 2 or less.

[0062] The adhesive composition can typically be prepared by mixing the first copolymer, the second copolymer, the crosslinking agent, and optionally any other components as described above.

[0063] In some embodiments, when a pigment is incorporated into the adhesive composition, it is preferable to prepare a pigment mixture by mixing (1) at least one selected from the group consisting of a second copolymer and a third copolymer containing structural units derived from an amide group monomer with the pigment, and then to produce the adhesive composition by mixing the pigment mixture with a mixture containing the first copolymer and a crosslinking agent; or (2) prepare a pigment mixture by mixing at least one selected from the group consisting of a second copolymer and a third copolymer containing structural units derived from an amide group with the pigment with a crosslinking agent, and then to produce the adhesive composition by mixing the pigment mixture with the first copolymer. By producing in this way, an adhesive composition with excellent pigment dispersibility can be obtained.

[0064] A third copolymer containing structural units derived from an amide group-containing monomer can be obtained by copolymerizing an amide group-containing monomer with at least one selected from the group consisting of monoethylene unsaturated monomers, (meth)acrylate monomers containing carbon atoms of biological origin, and carboxyl group-containing unsaturated monomers. From the viewpoint of pigment dispersibility and other properties, vinyl acetate, n-butyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate are preferred as monoethylene unsaturated monomers, and (meth)acrylic acid is preferred as the carboxyl group-containing unsaturated monomer. From the viewpoint of improving performance such as compatibility with the first copolymer and the second copolymer described above, it is preferable that the third copolymer contains the same or the same type of structural units as those derived from the monoethylene unsaturated monomer constituting the first copolymer and / or the second copolymer.

[0065] Examples of amide group-containing monomers include N-vinylcaprolactam, N-vinylpyrrolidone, (meth)acrylamide, N-methyl(meth)acrylamide, N,N-dimethyl(meth)acrylamide, and N-octyl(meth)acrylamide. Among these, (meth)acrylamide is preferred from the viewpoint of pigment dispersibility and other factors. The amide group-containing monomers can be used alone or in combination of two or more.

[0066] The proportion of constituent units derived from amide group-containing monomers can be approximately 0.01% by mass or more, approximately 0.05% by mass or more, or approximately 0.1% by mass or more, approximately 5% by mass or less, approximately 1% by mass or less, or approximately 0.5% by mass or less, relative to the third copolymer.

[0067] In some embodiments, if the third copolymer does not contain bio-derived constituent units, the proportion of constituent units derived from the monoethylene unsaturated monomers other than bio-derived constituent units can be, for example, about 85% by mass or more, about 90% by mass or more, or about 92% by mass or more, about 99.5% by mass or less, about 99% by mass or less, or about 98% by mass or less, relative to the third copolymer. If the third copolymer contains biologically derived constituent units, the proportion of such constituent units can be, for example, about 40% by mass or more, about 50% by mass or more, about 55% by mass or more, or about 60% by mass or more, about 95% by mass or less, about 90% by mass or less, about 80% by mass or less, about 75% by mass or less, about 70% by mass or less, or about 65% by mass or less, relative to the third copolymer. If present, the proportion of constituent units derived from the above-mentioned monoethylene unsaturated monomers other than the biologically derived constituent units can be, for example, about 10% by mass or more, about 15% by mass or more, about 20% by mass or more, about 25% by mass or more, or about 30% by mass or more, about 50% by mass or less, about 45% by mass or less, about 40% by mass or less, or about 35% by mass or less, relative to the third copolymer.

[0068] In some embodiments, the proportion of constituent units derived from carboxyl group-containing unsaturated monomers can be about 0.5% by mass or more, about 1% by mass or more, or about 2% by mass or more, about 15% by mass or less, about 10% by mass or less, or about 8% by mass or less, relative to the third copolymer.

[0069] When the adhesive composition and the adhesive layer formed from the composition contain a third copolymer containing structural units derived from an amide group-containing monomer, in one embodiment, the blending ratio of the third copolymer is less than about 20 parts by mass, about 18 parts by mass or less, about 15 parts by mass or less, about 10 parts by mass or less, or about 7 parts by mass or less, about 1 part by mass or more, about 2 parts by mass or more, or about 3 parts by mass or more, per 100 parts by mass of the first copolymer. An adhesive layer containing the third copolymer in such proportions can have excellent pigment dispersibility and improve performance such as opacity.

[0070] There are no particular restrictions on the pigments that can be incorporated into the adhesive layer; conventionally known inorganic or organic pigments can be used. The pigments may be surface-treated with silicon dioxide or aluminum oxide, etc. The pigments can be used individually or in combination of two or more types.

[0071] Examples of inorganic pigments include white pigments such as zinc carbonate, zinc oxide, zinc sulfide, and titanium dioxide (titanium oxide); colored pigments such as black iron oxide, yellow iron oxide, red iron oxide, ultramarine, Prussian blue, cobalt blue, titanium yellow, turquoise, and molybdate orange; and carbon blacks such as furnace black, channel black, thermal black, and acetylene black.

[0072] Examples of organic pigments include CIPigment White 6, CIPigment Black 7, CIPigment Red 122, 202, 254, 255, CIPigment Orange 43, CIPigment Violet 19, 23, CIPigment Blue 15, 15:1, 15:2, 15:3, 15:4, CIPigment Brown 23, 25, CIPigment Yellow 74, 109, 110, 128, CIPigment Green 7, and 36.

[0073] The amount of pigment added can be, for example, about 0.1% by mass or more, about 1% by mass or more, or about 5% by mass or more, about 55% by mass or less, about 50% by mass or less, about 20% by mass or less, or about 10% by mass or less, relative to the total adhesive composition (solids) or adhesive layer.

[0074] In some embodiments, the solids content of the adhesive composition of this disclosure is about 45% or more. The solids content of the adhesive composition can be about 48% or more, about 50% or more, about 52% or more, or about 55% or more, and can be about 80% or less, about 70% or less, about 65% or less, or about 60% or less. Using an adhesive composition with a high solids content can, for example, reduce the energy required to dry the adhesive layer, and as a result, can make a favorable contribution to environmental issues.

[0075] The thickness of the adhesive layer in this disclosure can be set appropriately considering the required adhesive strength, etc. For example, such a thickness can be about 10 micrometers or more, about 20 micrometers or more, or about 30 micrometers or more, and can be about 300 micrometers or less, about 200 micrometers or less, or about 100 micrometers or less.

[0076] The laminate of this disclosure includes a substrate.

[0077] There are no particular restrictions on the base material, and for example, (meth)acrylic resins containing polymethyl methacrylate (PMMA) and (meth)acrylic copolymers, resins having urethane bonds (e.g., polyurethane), fluororesins such as ethylene-tetrafluoroethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), and methyl methacrylate-vinylidene fluoride copolymer (PMMA / PVDF), silicone resins, polyolefins such as polyvinyl chloride (PVC), polycarbonate (PC), polyethylene (PE), and polypropylene (PP), polyesters such as polyethylene terephthalate (PET) and polyethylene naphthalate (PEN), polyamides such as nylon, ethylene / acrylic acid copolymer (EAA) and its ionomers, copolymers such as ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, and ethylene-vinyl alcohol copolymer (EVOH) can be used individually or in blends of two or more. Herein, in this disclosure, "resin having a urethane bond" can include not only urethane resins but also resins prepared using, for example, at least one selected from urethane (meth)acrylate and urethane (meth)acrylate oligomer, and urethane resins can also include (meth)acrylic urethane resins.

[0078] The substrate may have a multilayer structure. For example, the substrate may be a laminate of films formed from the above resin, or a multilayer coating of the above resin. The substrate may have a three-dimensional uneven shape, such as an embossed pattern, on all or part of its surface.

[0079] For example, the substrate can be formed by coating the adhesive layer with a resin composition, either directly or via a bonding layer or decorative layer. The substrate coating can be performed before or after applying the laminate to the adherend described later. Alternatively, a substrate film can be formed by coating a release liner with a resin composition, and then laminating this film to the adhesive layer. The substrate film can be formed by coating a release liner with a resin material such as a curable (meth)acrylic resin composition or a reactive polyurethane composition using a knife coat, bar coat, blade coat, doctor coat, roll coat, or cast coat, and then radiation curing or heat curing as needed.

[0080] As the base material, a film that has been pre-formed into a film shape by extrusion or stretching may be used. Such a film can be laminated to the adhesive layer. By using a film with high flatness, an appearance with higher surface flatness can be given to the article (structure). The base material can also be formed by multilayer extrusion with other layers. As the other layer, for example, a (meth)acrylic film can be used. As the (meth)acrylic film, for example, a resin containing polymethyl methacrylate (PMMA), butyl polyacrylate, (meth)acrylic copolymer, ethylene / acrylic copolymer, ethylene vinyl acetate / acrylic copolymer, etc. can be used in film form. (Meth)acrylic films have excellent transparency and / or scratch resistance, are resistant to heat and / or light, and are less prone to fading and / or changes in gloss. In addition, they have excellent moldability even without the use of plasticizers, and because plasticizers do not need to be used, they also have excellent stain resistance. Among these, those with PMMA as the main component are preferred. For example, if a (meth)acrylic resin with excellent scratch resistance is used as another layer, and a fluororesin such as ETFE, PVDF, or PMMA / PVDF with excellent chemical resistance is used as the base material, the resulting base material may possess the properties of both layers.

[0081] The substrates of this disclosure may contain optional components as long as they do not impair the performance (e.g., protective performance, decorative properties) according to the application. Examples of optional components include fillers, antioxidants, UV absorbers, light stabilizers, heat stabilizers, hard coat agents, gloss enhancers, dispersants, plasticizers, flow enhancers, surfactants, leveling agents, silane coupling agents, catalysts, pigments, and dyes. In particular, UV absorbers such as benzotriazole and Tinuvin® 400 (manufactured by BASF), and hindered amine light stabilizers (HALS) such as Tinuvin® 292 (manufactured by BASF) can be used to effectively prevent discoloration, fading, and deterioration of underlying adhesive layers. Hard coat agents may be included in the substrate or applied as a hard coat layer by coating the substrate separately. Optional components can be used individually or in combination of two or more.

[0082] The substrate may be partially translucent or opaque. However, if the laminate includes, for example, a decorative layer, it is preferable that the substrate be transparent from the viewpoint of the visibility of such layer.

[0083] The thickness of the substrate may vary, for example, it may be about 1 micrometer or more, about 5 micrometers or more, about 10 micrometers or more, about 30 micrometers or more, or about 50 micrometers or more, and it may also be about 200 micrometers or less, about 150 micrometers or less, about 100 micrometers or less, or about 90 micrometers or less.

[0084] In some embodiments, the laminates of the present disclosure optionally include additional layers. Such additional layers may include, for example, at least one selected from the group consisting of decorative layers (e.g., color layers, pattern layers, relief layers), glossy layers, bonding layers, intermediate film layers, and release liners. The additional layers may be applied to the entire surface or to a portion of the laminate. The additional layers may have a three-dimensional shape, such as an embossed pattern, on their surface. Laminates including a layer that can exhibit decorative properties (e.g., a decorative layer) may also be referred to as "decorative laminates." If they provide protective properties, such as the ability to prevent chipping by pebbles, they may also be referred to as "protective laminates."

[0085] Decorative layers include, but are not limited to, the following: color layers exhibiting paint colors, such as light colors like white and yellow, and dark colors like red, brown, green, blue, gray, and black; pattern layers that impart patterns such as wood grain, stone patterns, geometric patterns, and leather patterns to an object; relief layers with raised or recessed shapes on the surface; and combinations thereof.

[0086] The decorative layer is not limited to the following, but can be applied directly or via a bonding layer to all or part of the layers constituting the laminate, such as the substrate and / or adhesive layer.

[0087] The material for the color layer is not limited to the following, but for example, materials can be used in which pigments such as inorganic pigments such as carbon black, lead yellow, yellow iron oxide, red iron oxide, etc., phthalocyanine pigments such as phthalocyanine blue, phthalocyanine green, etc., organic pigments such as azolake pigments, indigo pigments, perinone pigments, perylene pigments, quinophthalone pigments, dioxazine pigments, quinacridone pigments such as quinacridone red, etc. are dispersed in a binder resin such as (meth)acrylic resin or a resin having urethane bonds.

[0088] The color layer can be formed using such materials by coating methods such as gravure coating, roll coating, die coating, bar coating, and knife coating.

[0089] The pattern layer is not limited to the following, but may be a pattern such as a design, logo, or illustration applied directly to the substrate and / or adhesive layer using a printing method such as gravure direct printing, gravure offset printing, inkjet printing, laser printing, or screen printing. Alternatively, a film or sheet having a design, logo, or illustration formed by a coating such as gravure coating, roll coating, die coating, bar coating, or knife coating, or by die-cutting or etching may be used. As for the material of the pattern layer, for example, the same material used for the color layer may be used.

[0090] As the relief layer, a thermoplastic resin film having an uneven surface shape achieved by conventionally known methods, such as embossing, scratching, laser processing, dry etching, or hot pressing, can be used. Alternatively, a thermosetting or radiation-curable resin, such as a curable (meth)acrylic resin, can be applied to a release liner having an uneven surface shape, cured by heating or radiation, and then the release liner can be removed to form the relief layer.

[0091] The thermoplastic resin, thermosetting resin, and radiation-curable resin used in the relief layer are not particularly limited, but examples include fluororesins, polyester resins such as PET and PEN, (meth)acrylic resins, polyolefin resins such as polyethylene and polypropylene, thermoplastic elastomers, polycarbonate, polyamide, ABS resin, acrylonitrile-styrene resin, polystyrene, vinyl chloride, and resins having urethane bonds. The relief layer may also contain at least one of the pigments used in the color layer.

[0092] The decorative layer of the present disclosure may include, to the extent that it does not adversely affect the effects of the present disclosure, optional components such as fillers, reinforcing agents, antioxidants, ultraviolet absorbers, light stabilizers, heat stabilizers, dispersants, plasticizers, flow enhancers, surfactants, leveling agents, silane coupling agents, catalysts, and the like.

[0093] The thickness of the decorative layer is not particularly limited and can be adjusted as appropriate according to the required level of decoration. For example, such a thickness can be approximately 1 micrometer or more, approximately 3 micrometers or more, or approximately 5 micrometers or more, and approximately 50 micrometers or less, approximately 40 micrometers or less, or approximately 30 micrometers or less.

[0094] The glossy layer is not limited to the following, but may be a layer containing a metal selected from aluminum, nickel, gold, silver, copper, platinum, chromium, iron, tin, indium, titanium, lead, zinc, germanium, or an alloy or compound thereof, formed on all or part of the substrate and / or adhesive layer of the laminate by vacuum deposition, sputtering, ion plating, plating, etc. The thickness of the glossy layer can be set appropriately according to the required decorative effect.

[0095] The laminates of this disclosure may use a bonding layer (sometimes called a "primer layer," etc.) to bond additional layers in the laminate. As the bonding layer, commonly used solvent-type, emulsion-type, pressure-sensitive, heat-sensitive, thermosetting, or UV-curing adhesives such as (meth)acrylic, polyolefin-based, polyurethane-based, polyester-based, and rubber-based adhesives can be used. The bonding layer can be applied by known coating methods, etc.

[0096] The laminate of this disclosure may include an intermediate film layer. As the intermediate film layer, for example, a resin film of a resin having urethane bonds, polyolefin such as polyvinyl chloride, polyethylene, or polypropylene, polyester such as polyethylene terephthalate or polybutylene terephthalate, (meth)acrylic polymer, or fluoropolymer can be used.

[0097] The thickness of the intermediate film layer can be approximately 5 micrometers or more, approximately 10 micrometers or more, or approximately 15 micrometers or more, approximately 200 micrometers or less, approximately 100 micrometers or less, or approximately 50 micrometers or less.

[0098] The laminates of this disclosure typically have a release liner applied to the adhesive layer. Examples of release liners include paper; plastic materials such as polyethylene, polypropylene, polyester (e.g., PET), and cellulose acetate; and paper coated with such plastic materials. These liners may have a surface that has been released with a release agent such as silicone.

[0099] The thickness of the release liner can generally be about 5 micrometers or more, about 15 micrometers or more, or about 25 micrometers or more, and can be about 500 micrometers or less, about 300 micrometers or less, about 100 micrometers or less, or about 50 micrometers or less.

[0100] The laminate of this disclosure may be, for example, a single sheet, a roll wound into a roll, or a three-dimensional object.

[0101] The following manufacturing method is described as an example, but the manufacturing method of the laminate described herein is not limited thereto.

[0102] For example, in the case of a laminate comprising a release liner, an adhesive layer, a decorative layer (e.g., a color layer), and a substrate in that order, a color layer composition containing a pigment is coated onto the substrate, and a drying and curing process is applied as necessary to form the color layer. Subsequently, an adhesive composition is coated onto the color layer, and a drying and curing process is applied as necessary to form the adhesive layer, after which the release liner can be bonded to the adhesive layer to form the laminate.

[0103] In some embodiments, the laminates of the present disclosure described above are arranged on a substrate via an adhesive layer to provide an article comprising the laminate.

[0104] There are no particular restrictions on the material of the substrate to which the laminate can be applied. Examples of such materials include resin materials (e.g., polyolefin resins, polyester resins, (meth)acrylic resins, polycarbonate resins, resins having urethane bonds, acrylonitrile-butadiene-styrene copolymers), inorganic materials (e.g., glass, ceramics, concrete, gypsum, calcium silicate, natural stone, asphalt), rubber materials, fabric materials (e.g., woven fabrics, knitted fabrics, nonwoven fabrics), metal or metal alloy materials (e.g., iron, aluminum, stainless steel), and wood-based materials including paper.

[0105] There are no particular restrictions on the shape or structure of the adherend; for example, it may be planar (e.g., film shape, plate shape), curved shape, irregular shape, or three-dimensional shape, and it may be a single-layer structure, a laminated structure, or a composite structure in which multiple members of different shapes or materials are combined.

[0106] The laminates of this disclosure can be used in a variety of applications. Such applications include, for example, signs (e.g., internally illuminated signs and externally illuminated signs); signs (e.g., internally illuminated signs and externally illuminated signs); various interior or exterior parts, such as interior or exterior parts for vehicles such as automobiles, trains, aircraft, and ships (e.g., roof members, pillar members, door trim members, instrument panel members, front members such as hoods, bumper members, fender members, side sill members, and interior panel members); and interior or exterior parts for buildings (e.g., window glass, doors, sashes, roof members such as tiles, exterior wall members, wallpaper, etc.); electrical appliances such as personal computers, smartphones, mobile phones, refrigerators, and air conditioners; stationery; furniture; desks; and various containers such as cans. The adhesive layer constituting the laminate of this disclosure has excellent durability, such as weather resistance, despite the fact that at least one of the first copolymer and the second copolymer used contains structural units derived from (meth)acrylate monomers containing bio-derived carbon atoms. Therefore, it can be suitably used for exterior applications, more specifically for the exterior of vehicles (e.g., automobiles) and the exterior of buildings (e.g., exterior wall members). In some embodiments, the laminate of this disclosure also has excellent conformability and can therefore be suitably used for rough surfaces. For example, the laminate of this disclosure can be suitably used for rough surfaces (e.g., wall surfaces) having irregularities with a maximum height from the protrusion to the bottom of about 1 mm or more, or about 1.5 mm or more, 1 cm or less, 7 mm or less, 5 mm or less, 3 mm or less, 2.5 mm or less, or 2 mm or less.

[0107] There are no particular limitations on the method of applying the laminate of this disclosure to the adherend (support member) constituting the article, and known methods can be used as appropriate. Examples of such methods include manual bonding, insert injection molding, in-mold molding, over-mold molding, two-color injection molding, core-back injection molding, sandwich injection molding, and other injection molding methods, lamination methods, and three-dimensional heat stretch molding (TOM). [Examples]

[0108] The following examples illustrate specific embodiments of the present disclosure, but the present invention is not limited thereto. All parts and percentages are by mass unless otherwise specified. Numerical values ​​include errors inherent to the measurement principle and measuring device. Numerical values ​​are shown with significant figures after normal rounding.

[0109] Table 1 shows the various materials used. In the table, "Mw" and "Tg" refer to "weight-average molecular weight" and "glass transition temperature," respectively. For the first, second, and third copolymers, polymerizable compositions were prepared by mixing each monomer component, a chain transfer agent (such as isooctyl thioglycolate), a polymerization initiator (such as 2,2'-azobis(2,4-dimethylvaleronitrile)), and a solvent (such as ethyl acetate) so that the mass ratio of constituent units derived from the monomers listed in the table (e.g., NOAA (n-octyl acrylate), BA (n-butyl acrylate), AA (acrylic acid)) was such that polymerizable compositions were prepared by polymerizing these compositions using conventional polymerization methods. Here, NOAA (n-octyl acrylate) and 2OA (2-octyl acrylate) correspond to (meth)acrylate monomers containing carbon atoms of biological origin.

[0110] [Table 1]

[0111] <Example Test 1> In Test Example 1, the adhesive strength, heat shrinkage resistance, and reworkability of an adhesive layer without pigment were evaluated.

[0112] Example 1 An adhesive composition was prepared by mixing a first copolymer (ADH1) containing structural units derived from a carboxyl group-containing monomer, a second copolymer (HP1) containing structural units derived from an amino group-containing monomer, and a crosslinking agent (TETRAD®-X) in a mass ratio of 100:5:0.18 based on non-volatile content. This adhesive composition was coated onto a release liner (SCW1034) using a knife coater. The resulting adhesive layer was dried at 95°C for 5 minutes to obtain an adhesive layer with a thickness of 40 micrometers. A substrate (UW5002) was laminated onto this adhesive layer to obtain the test sample of Example 1.

[0113] Examples 2-10 Test samples for Examples 2 to 10 were obtained in the same manner as in Example 1, except that the first copolymer, the thickness of the adhesive layer, and at least one of the substrates were changed to those shown in Table 2.

[0114] Reference examples 1~2 Except for changing the first copolymer, the thickness of the adhesive layer, and at least one of the substrates to those shown in Table 2, test samples for Reference Examples 1 and 2 were obtained in the same manner as in Example 1. In Reference Examples 1 and 2, test samples were used that included an adhesive layer prepared using conventional petroleum-derived materials.

[0115] Evaluation Test 1 Each test sample obtained was evaluated according to the following test method. The results are shown in Table 2.

[0116] Adhesion strength test 1: Adhesion strength to painted board Test specimens were prepared by cutting the test sample into pieces 25 mm wide and 150 mm long. In accordance with JIS Z 0237 8.2.3, the test specimens were applied to a melamine-coated board (manufactured by Paltec Co., Ltd., Hiratsuka City, Kanagawa Prefecture, Japan) in an atmosphere of 20°C. After leaving the test specimens at 20°C for 48 hours, the 180-degree peel force of the test specimens was measured using a Tensilon universal material tester (manufactured by A&D Company, Limited, Toshima-ku, Tokyo, Japan). The air jaw speed was set to 300 mm per minute.

[0117] Adhesion strength test 2: Adhesion strength to aluminum plate Test specimens were prepared by cutting the test sample into pieces 25 mm wide and 150 mm long. The specimens were applied to an aluminum plate in an atmosphere of 20°C, according to JIS Z 0237 8.2.3. After leaving the specimens at 20°C for 48 hours, the 180-degree peel force of the specimens was measured using a Tensilon universal material testing machine (manufactured by A&D Company, Limited (Toshima-ku, Tokyo, Japan)). The air jaw speed was set to 300 mm per minute.

[0118] Heat shrinkage test Test specimens were prepared by cutting the test sample into pieces 50 mm wide and 100 mm long. These specimens were mounted on an aluminum plate and set at 23°C for 24 hours, after which the specimens were cut in a cross shape. These specimens were left at 65°C for 48 hours. After thermal aging, the maximum width of the cut opening (mouth opening) was measured under a microscope.

[0119] Reworkability Test Test specimens were prepared by cutting the test sample into pieces 210 mm wide and 300 mm long. The test specimens were applied to a melamine-coated board (manufactured by Paltec Co., Ltd., Hiratsuka City, Kanagawa Prefecture, Japan) using a squeegee in a 25°C atmosphere, and then quickly peeled off by hand. Test specimens that could be easily peeled off without stretching were evaluated as "good," those that were not stretched but felt heavy to peel off were evaluated as "acceptable," and those that had strong tack, were difficult to peel off, and were stretched were evaluated as "poor."

[0120] [Table 2]

[0121] <Example Test 2> In Test Example 2, in addition to evaluating the adhesive strength, heat shrinkage resistance, and reworkability of the pigment-containing adhesive layer, the opacity, tensile strength, elongation properties, conformability, and gloss retention rate were also evaluated.

[0122] Table 3 shows the pigment mixtures used to prepare the adhesive compositions containing pigments, and Table 4 shows the amount (parts by mass) and solid content (%) of each component in the adhesive compositions prepared using such pigment mixtures. Here, the amounts of each component in Table 4 are based on the non-volatile content.

[0123] [Table 3]

[0124] [Table 4]

[0125] Example 11 The adhesive composition (CA1) shown in Table 4 was applied to a release liner (SLK-110AWP#3009) using a knife coater. The resulting white adhesive layer was dried at 95°C for 5 minutes to obtain an adhesive layer with a thickness of 39 micrometers. A substrate (UW5002) was laminated onto this adhesive layer to obtain the test sample of Example 11.

[0126] Examples 12-18 Test samples for Examples 12 to 18 were obtained in the same manner as in Example 11, except that at least one of the adhesive composition, adhesive layer thickness, and substrate was changed to those shown in Table 5.

[0127] Reference examples 3~6 Except for changing the adhesive composition, the thickness of the adhesive layer, and at least one of the substrates as shown in Table 5, test samples for Reference Examples 3 to 6 were obtained in the same manner as in Example 11. In Reference Examples 3 to 6, test samples were used that had an adhesive layer prepared using conventional petroleum-derived materials.

[0128] Evaluation Test 2 Each test sample obtained was evaluated according to the following test method. The results are shown in Table 5. Here, the tests for adhesion to painted boards, adhesion to aluminum boards, heat shrinkage, and reworkability were conducted using the same test methods as in Evaluation Test 1 described above.

[0129] Opacity test Test specimens were prepared by cutting the test sample into 100mm x 50mm squares. These specimens were attached to "Opacity Chart Paper" (zebra pattern). A spectrophotometer (CM-3700d, manufactured by Konica Minolta, Inc. (Chiyoda-ku, Tokyo, Japan)) was used to measure L in the white and black regions. * a * and b * The value of the white area was measured. * a1 * , b1 * The value of the black area is L2 * a2 * , b2 * The color difference (ΔE) was calculated using the following equation 1:

number

[0130] Yield point evaluation test Test specimens were prepared by cutting the test sample into pieces 25 mm wide and 150 mm long. The tensile force and elongation of the test specimens were measured using a Tensilon universal material testing machine (manufactured by A&D Company, Limited (Toshima-ku, Tokyo, Japan)) in an atmosphere of 20°C. The air jaw speed was set to 300 mm per minute, and the air jaw spacing was 100 mm. The yield point was determined from the graphs of elongation (x axis) and tensile force (y axis).

[0131] Elongation test Test specimens were prepared by cutting the test sample into pieces 25 mm wide and 150 mm long. The elongation of the test specimens was measured using a Tensilon universal material testing machine (manufactured by A&D Company, Limited (Toshima-ku, Tokyo, Japan)) in an atmosphere of 20°C. The air jaw speed was set to 300 mm per minute, and the air jaw spacing was set to 100 mm.

[0132] Tensile strength test Test specimens were prepared by cutting the test sample into pieces 25 mm wide and 150 mm long. The tensile force and elongation of the test specimens were measured using a Tensilon universal material testing machine (manufactured by A&D Company, Limited (Toshima-ku, Tokyo, Japan)) in an atmosphere of 20°C. The air jaw speed was set to 300 mm per minute, and the air jaw spacing was set to 100 mm. The tensile force at 2% elongation was recorded as the tensile strength (2% tensile strength).

[0133] Followability test Test specimens were prepared by cutting the test sample to a width of 70 mm and a length of 75 mm. In an atmosphere of 25°C, the test specimens equipped with pre-masks were attached to a stucco-coated substrate (manufactured by Test Materials Co., Ltd., Kawaguchi City, Saitama Prefecture, Japan). The pre-masks were removed, and the test specimens were pressed without heating using a rivet brush "PFA-1" (manufactured by 3M Japan Limited, Shinagawa Ward, Tokyo, Japan). The press was performed three times back and forth on the test specimen. The maximum roughness between the top and bottom of the substrate surface was approximately 1.5 mm. After attaching the test specimens, the conformability to the rough substrate surface was visually judged. Specimens with good conformability to the rough substrate surface were evaluated as "good," and those with insufficient conformability to the rough substrate surface were evaluated as "poor."

[0134] Gloss retention evaluation test Test specimens were prepared in the same manner as in the conformability test. The specimens were left in a 65°C oven for 48 hours. Using a portable gloss meter (GMX-202, manufactured by Murakami Color Research Institute Co., Ltd. (Chuo-ku, Tokyo, Japan)), the initial gloss value and the gloss value after aging at 65°C were measured, and the gloss retention rate was calculated using the following formula 2: Gloss retention rate (%) = Gloss value after aging at 65°C / Initial gloss value × 100 ... Equation 2 Here, the test was repeated three times, and the average value was recorded as the representative value. Products with a gloss retention rate of less than 200% were evaluated as "good," and those with a gloss retention rate of 200% or more were evaluated as "poor."

[0135] [Table 5]

[0136] It will be apparent to those skilled in the art that the above embodiments and examples can be modified in various ways without departing from the basic principles of the present invention. Furthermore, it will be apparent to those skilled in the art that various improvements and modifications of the present invention can be implemented without departing from the spirit and scope of the invention. [Explanation of Symbols]

[0137] 10 Base material 20 Adhesive layer 30 Release Liner 100-layer structure

[0138] Some embodiments of this disclosure are described in the following sections [1]-

[13] . [Item 1] The adhesive layer comprises a first copolymer containing structural units derived from carboxyl group-containing monomers, a second copolymer containing structural units derived from amino group-containing monomers, and a cured product of a crosslinking agent, and a substrate. The first copolymer has a weight-average molecular weight of 800,000 or less and a glass transition temperature of less than 0°C. The second copolymer has a weight-average molecular weight of 30,000 or more and 100,000 or less, and a glass transition temperature of 0°C or higher. At least one of the first copolymer and the second copolymer contains constituent units derived from a (meth)acrylate monomer containing bio-derived carbon atoms. Laminated structure. [Item 2] The laminate according to item 1, wherein the molecular weight distribution of the first copolymer and the second copolymer is 10 or less. [Item 3] The laminate according to item 1 or 2, wherein the (meth)acrylate monomer has an alkyl group having 4 to 12 carbon atoms. [Item 4] The laminate according to any one of items 1 to 3, wherein the (meth)acrylate monomer comprises at least one selected from the group consisting of n-octyl (meth)acrylate and 2-octyl (meth)acrylate. [Item 5] A laminate according to any one of items 1 to 4, wherein the proportion of constituent units derived from (meth)acrylate monomers containing bio-derived carbon atoms is 40% by mass or more relative to the copolymer containing said constituent units. [Item 6] The laminate according to any one of items 1 to 5, wherein the content of the second copolymer is 1 part by mass or more and less than 20 parts by mass per 100 parts by mass of the first copolymer. [Item 7] The laminate according to any one of items 1 to 6, wherein the adhesive layer further comprises a pigment. [Item 8] A first copolymer comprising structural units derived from a carboxyl group-containing monomer, a second copolymer comprising structural units derived from an amino group-containing monomer, and a crosslinking agent, The first copolymer has a weight-average molecular weight of 800,000 or less and a glass transition temperature of less than 0°C. The second copolymer has a weight-average molecular weight of 30,000 or more and 100,000 or less, and a glass transition temperature of 0°C or higher. At least one of the first copolymer and the second copolymer contains constituent units derived from a (meth)acrylate monomer containing bio-derived carbon atoms. Adhesive composition. [Item 9] The adhesive composition according to item 8, wherein the molecular weight distribution of the first copolymer and the second copolymer is 10 or less. [Item 10] An adhesive composition according to item 8 or 9, wherein the solid content is 45% or more. [Item 11] An adhesive composition according to any one of items 8 to 10, further comprising a pigment. [Item 12] A method for producing an adhesive composition as described in any one of items 8 to 10, Mixing the first copolymer, the second copolymer, and the crosslinking agent, A manufacturing method that includes this. [Item 13] A method for producing the adhesive composition described in item 11, A pigment mixture is prepared by mixing at least one selected from the group consisting of the second copolymer and a third copolymer containing structural units derived from an amide group monomer with the pigment, and the pigment mixture is mixed with the mixture containing the first copolymer and the crosslinking agent, or A pigment mixture is prepared by mixing at least one selected from the group consisting of the second copolymer and a third copolymer containing structural units derived from an amide group monomer, the crosslinking agent, and the pigment, and the pigment mixture is mixed with the first copolymer. A manufacturing method that includes this.

Claims

1. The adhesive layer comprises a first copolymer containing structural units derived from carboxyl group-containing monomers, a second copolymer containing structural units derived from amino group-containing monomers, and a cured product of a crosslinking agent, and a substrate. The first copolymer has a weight-average molecular weight of 800,000 or less and a glass transition temperature of less than 0°C. The second copolymer has a weight-average molecular weight of 30,000 or more and 100,000 or less, and a glass transition temperature of 0°C or higher. At least one of the first copolymer and the second copolymer contains constituent units derived from a (meth)acrylate monomer containing bio-derived carbon atoms. Laminated structure.

2. The laminate according to claim 1, wherein the molecular weight distribution of the first copolymer and the second copolymer is 10 or less.

3. The laminate according to claim 1 or 2, wherein the (meth)acrylate monomer has an alkyl group having 4 to 12 carbon atoms.

4. The laminate according to claim 1 or 2, wherein the (meth)acrylate monomer comprises at least one selected from the group consisting of n-octyl (meth)acrylate and 2-octyl (meth)acrylate.

5. The laminate according to claim 1 or 2, wherein the proportion of constituent units derived from (meth)acrylate monomers containing bio-derived carbon atoms is 40% by mass or more with respect to the copolymer containing said constituent units.

6. The laminate according to claim 1 or 2, wherein the content of the second copolymer is 1 part by mass or more and less than 20 parts by mass per 100 parts by mass of the first copolymer.

7. The laminate according to claim 1 or 2, wherein the adhesive layer further comprises a pigment.

8. A first copolymer comprising structural units derived from a carboxyl group-containing monomer, a second copolymer comprising structural units derived from an amino group-containing monomer, and a crosslinking agent, The first copolymer has a weight-average molecular weight of 800,000 or less and a glass transition temperature of less than 0°C. The second copolymer has a weight-average molecular weight of 30,000 or more and 100,000 or less, and a glass transition temperature of 0°C or higher. At least one of the first copolymer and the second copolymer contains constituent units derived from a (meth)acrylate monomer containing bio-derived carbon atoms. Adhesive composition.

9. The adhesive composition according to claim 8, wherein the molecular weight distribution of the first copolymer and the second copolymer is 10 or less.

10. The adhesive composition according to claim 8 or 9, wherein the solid content is 45% or more.

11. The adhesive composition according to claim 8 or 9, further comprising a pigment.

12. A method for producing the adhesive composition according to claim 8 or 9, Mixing the first copolymer, the second copolymer, and the crosslinking agent, A manufacturing method that includes this.

13. A method for producing the adhesive composition according to claim 11, A pigment mixture is prepared by mixing at least one selected from the group consisting of the second copolymer and a third copolymer containing structural units derived from an amide group monomer with the pigment, and the pigment mixture is mixed with the mixture containing the first copolymer and the crosslinking agent, or A pigment mixture is prepared by mixing at least one selected from the group consisting of the second copolymer and a third copolymer containing structural units derived from an amide group monomer, the crosslinking agent, and the pigment, and then mixing the pigment mixture with the first copolymer. A manufacturing method that includes this.

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