Water-resistant substrate

Abstract

To provide a water-resistant substrate excellent in water resistance.SOLUTION: A water-resistant substrate is formed by impregnating a fibrous core material with a cyclodextrin compound. The cyclodextrin compound is preferably a polymer containing cyclodextrin or a cyclodextrin derivative, or a non-polymeric cyclodextrin compound having a hydrophobic group. In the former case, the polymer is preferably a copolymer of a cyclodextrin derivative with a polymerizable group and an acrylic monomer. In the latter case, the non-polymeric cyclodextrin compound is preferably impregnated into the core material together with an acrylic polymer.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a water-resistant substrate having a core made of a fibrous material and exhibiting water resistance. [Background technology]

[0002] Paper has traditionally been used for a variety of purposes, such as product tags and product labels. Depending on the purpose, the paper may be required to be water-resistant. For example, water-resistant paper impregnated with synthetic resin or coated with synthetic resin is known. These types of water-resistant paper have a paper fiber core, which is impregnated with or coated with synthetic resin.

[0003] For example, Patent Document 1 proposes waterproof paper that includes a paper base material containing a siloxane having a specific chemical structure. From the perspective of environmental issues, it is desirable for paper to be recyclable. Therefore, Patent Document 1 aims to provide waterproof paper that combines water resistance and disintegration properties. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2001-131894 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above-mentioned circumstances, and has as its object to provide a water-resistant substrate having excellent water resistance. [Means for solving the problem]

[0006] To achieve the above object, first, the present invention provides a water-resistant substrate obtained by impregnating a core material made of a fibrous material with a cyclodextrin compound (Invention 1).

[0007] The cyclodextrin compound in the above invention (Invention 1) is a material that becomes water-insoluble through derivatization or polymerization (especially copolymerization with acrylic monomers). By impregnating a core material with such a cyclodextrin compound, the cyclodextrin compound protects the fibrous material (core material) when immersed in water or when water adheres to it. Therefore, the water-resistant substrate according to the above invention (Invention 1) has excellent water resistance.

[0008] In the above invention (Invention 1), the content of the fibrous material is 5 g / m 2 More than 200g / m 2 It is preferable that the following is true (Invention 2):

[0009] In the above inventions (Inventions 1 and 2), the basis weight is 11 g / m 2 More than 300g / m 2 It is preferable that the following is true (Invention 3):

[0010] In the above inventions (Inventions 1 to 3), it is preferable that when the water-resistant substrate is immersed in ethyl acetate for 1 hour, the weight loss rate calculated by the following formula is 20% or more (Invention 4). Weight loss rate (%) = [{(weight of water-resistant substrate before immersion - weight of core material before immersion) - (weight of water-resistant substrate after immersion - weight of core material after immersion)} / (weight of water-resistant substrate before immersion - weight of core material before immersion)] x 100

[0011] In the above inventions (Inventions 1 to 4), it is preferable that the tear strength measured by the trouser tear method at a test speed of 10 mm / min is 0.1 N or more (Invention 5).

[0012] In the above inventions (Inventions 1 to 5), it is preferable that the maximum load measured in a tensile test on the water-resistant substrate having a width of 10 mm, with a measurement length of 10 mm and a tensile speed of 100 mm / min, is 0.5 N or more (Invention 6).

[0013] In the above inventions (Inventions 1 to 6), it is preferable that the water-resistant substrate having a width of 10 mm is immersed in water for 10 minutes, and then the water-resistant substrate is subjected to a tensile test with a measurement length of 10 mm and a tensile speed of 100 mm / min, and the maximum load measured is 0.5 N or more (Invention 7).

[0014] In the above inventions (Inventions 1 to 7), when the maximum load measured in a tensile test on the water-resistant substrate having a width of 10 mm is L1 (N), and the water-resistant substrate having a width of 10 mm is immersed in water for 10 minutes and then the water-resistant substrate is subjected to a tensile test on the water-resistant substrate having a measurement length of 10 mm and a tensile speed of 100 mm / min, the absolute value of the maximum load change rate (%) calculated by the following formula is preferably less than 100% (Invention 8). Maximum load change rate (%) = {(L1-L2) / L1} x 100

[0015] In the above inventions (Inventions 1 to 8), it is preferable that the maximum load elongation measured by a tensile test on the water-resistant substrate having a width of 10 mm, with a measurement length of 10 mm and a tensile speed of 100 mm / min, is 10% or more (Invention 9).

[0016] In the above inventions (Inventions 1 to 9), it is preferable that the water-resistant substrate having a width of 10 mm is immersed in water for 10 minutes, and then the water-resistant substrate is subjected to a tensile test at a measurement length of 10 mm and a tensile speed of 100 mm / min, and the maximum load elongation measured is 10% or more (Invention 10).

[0017] In the above inventions (Inventions 1 to 10), when the maximum load elongation measured by conducting a tensile test on the water-resistant substrate having a width of 10 mm at a measurement length of 10 mm and a pulling speed of 100 mm / min is defined as E1 (%), and when the water-resistant substrate having a width of 10 mm is immersed in water for 10 minutes and then a tensile test on the water-resistant substrate having a width of 10 mm is conducted at a measurement length of 10 mm and a pulling speed of 100 mm / min, the absolute value of the maximum load elongation change rate (%) calculated by the following formula is preferably less than 100% (Invention 11). Maximum load elongation change rate (%) = {(E1-E2) / E1} x 100

[0018] In the above inventions (Inventions 1 to 11), the cyclodextrin compound is preferably a polymer containing cyclodextrin or a cyclodextrin derivative (Invention 12).

[0019] In the above invention (Invention 12), the polymer is preferably a copolymer of a cyclodextrin derivative having a polymerizable group and an acrylic monomer (Invention 13).

[0020] In the above inventions (Inventions 1 to 11), it is also preferable that the cyclodextrin compound is a non-polymerizable cyclodextrin compound having a non-hydrophilic group (Invention 14).

[0021] In the above invention (Invention 14), it is preferable that the non-polymerizable cyclodextrin compound is impregnated into the core material together with an acrylic polymer (Invention 15).

[0022] In the above inventions (Inventions 1 to 15), the fibrous material is preferably paper fiber (Invention 16). [Effects of the Invention]

[0023] The water-resistant substrate according to the present invention has excellent water resistance. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, an embodiment of the present invention will be described. A water-resistant substrate according to one embodiment of the present invention comprises a core material made of a fibrous material impregnated with a cyclodextrin compound. Cyclodextrin compounds are materials that become water-insoluble through derivatization or polymerization (especially copolymerization with acrylic monomers). By impregnating the core material with such a cyclodextrin compound, the cyclodextrin compound protects the fibrous material (core material) when immersed in water or when water adheres to it. This results in the water-resistant substrate according to this embodiment having excellent water resistance. Specifically, the changes in maximum load and maximum load elongation before and after immersing the water-resistant substrate according to this embodiment in water for 10 minutes can be minimized.

[0025] When the cyclodextrin compound is a polymer (resin), impregnation of the core material with the polymer produces high stress, resulting in high strength (strong paper strength), while the supramolecular crosslinked structure does not hinder solvent solubility. Furthermore, when the polymer is solvent-soluble, separation and recovery of the resin from the core material is easy, resulting in excellent recyclability. Furthermore, certain polymers of cyclodextrin compounds can flow upon heating even if they are not tacky at room temperature, making it possible to thermally bond the water-resistant substrate by heating. For example, when forming wiring on the water-resistant substrate of this embodiment, the wiring can be easily bonded by thermal bonding, and by dissolving the wiring in a solvent, the resin and fibrous material can be easily separated and recovered. Therefore, the water-resistant substrate of this embodiment is suitable for product tags and the like having wiring, etc.

[0026] Furthermore, it is believed that the cyclodextrin compound allows the ink resin to be adsorbed into the pores inside the cyclodextrin and the irregularities on the molecular surface of the cyclodextrin, and therefore the water-resistant substrate according to this embodiment has excellent ink adhesion and is suitable for printing with various printers.

[0027] 1. Each element 1-1. Core material The water-resistant substrate according to this embodiment includes a core made of a fibrous material. The water-resistant substrate and core according to this embodiment are usually in the form of a sheet, but are not limited thereto and may be in various shapes and forms. In this specification, the "core" refers to a member that forms the skeleton of the water-resistant substrate and is a member (made of a fibrous material) before being impregnated with resin.

[0028] Examples of fibrous materials constituting the core material in this embodiment include paper fibers primarily composed of plant fibers; natural fibers such as silk, cotton, and wool; chemical fibers (including synthetic and semi-synthetic fibers) such as polyester, acrylic, polyethylene naphthalate, nylon, aramid, polylactic acid, and acetate; and inorganic fibers such as glass, carbon, and ceramic. Examples of plant fibers constituting paper fibers include kraft pulp, mechanical pulp, and recycled paper pulp, and may be wood pulp or non-wood pulp. Examples of wood pulp include hardwood pulp, softwood pulp, rag pulp, linter pulp, linen pulp, and pulp from paper mulberry, mitsumata, and gampi. Examples of non-wood pulp include bamboo pulp, straw pulp, bagasse pulp, and kenaf pulp. Among these, paper fibers, which generally have low water resistance, are preferred. When the fibrous material constituting the core material is paper fiber, the effect of improving water resistance due to the cyclodextrin compound is more clearly manifested. The fibrous material may be used alone or in combination of two or more types.

[0029] The core material in this embodiment can be manufactured by a known method using the above-mentioned fibrous material. When the fibrous material constituting the core material is paper fiber, the core material is paper, and the paper can be manufactured by a known method.

[0030] The content of the fibrous material in the water-resistant substrate according to this embodiment, in other words, the basis weight of the core material, is 5 to 200 g / m 2 It is preferable that the density is 6 to 100 g / m 2 It is more preferable that the density is 7 to 75 g / m 2It is preferable that the density is 8 to 50 g / m 2 It is preferable that the density is 9 to 25 g / m 2 This is preferable. This makes it possible to more clearly demonstrate the effect of improving water resistance due to the cyclodextrin compound. In addition, the desired paper strength can be obtained, and the paper has excellent disintegration properties when recycled. Furthermore, the paper can be easily impregnated with the cyclodextrin compound.

[0031] 1-2. Cyclodextrin compounds The cyclodextrin compound in this embodiment may be a cyclodextrin (cyclodextrin derivative) having a substituent, or may be a cyclodextrin or cyclodextrin derivative incorporated into a polymer (a polymer having cyclodextrin or a cyclodextrin derivative as a constituent monomer). The cyclodextrin derivative is preferably a cyclodextrin derivative having a non-hydrophilic substituent (non-hydrophilic group), and may be a non-polymerizable monomer. Among the above, the cyclodextrin compound in this embodiment is preferably a polymer having cyclodextrin or a cyclodextrin derivative as a constituent monomer, from the viewpoint of obtaining not only excellent water resistance but also high strength (strong paper strength), recyclability including solvent solubility (separation and recovery of the cyclodextrin compound from the core material), and thermal adhesiveness in the water-resistant substrate according to this embodiment.

[0032] The polymer is preferably a copolymer of an acrylic monomer and a cyclodextrin derivative having a polymerizable group, and more preferably a polymer having a main chain formed by copolymerizing an acrylic monomer and a cyclodextrin compound having a polymerizable group, which provides the above-mentioned effects (water resistance, paper strength, recyclability, and thermal adhesiveness) more excellently.

[0033] The cyclodextrin compound as the polymer in this embodiment is preferably a polymer (hereinafter sometimes referred to as a "cyclodextrin polymer P") obtained by copolymerizing the acrylic monomer (A) and the polymerizable cyclodextrin compound (Bp) having a polymerizable group (hereinafter sometimes referred to as a "polymerizable cyclodextrin compound") (Bp), preferably further using a photopolymerization initiator (C).

[0034] On the other hand, in this embodiment, a cyclodextrin compound without a polymerizable functional group, i.e., a non-polymerizable cyclodextrin compound (Bn), can also be used as a monomer. This non-polymerizable cyclodextrin compound (Bn) is preferably a cyclodextrin derivative having a non-hydrophilic group. In this case, it is preferable that the non-polymerizable cyclodextrin compound (Bn) coexists in a polymer of the acrylic monomer (A) (the acrylic polymer (AP) described below) (a mixture of the acrylic polymer (AP) and the non-polymerizable cyclodextrin compound (Bn)).

[0035] (1) Each ingredient (1-1) Acrylic Monomer (A) The acrylic monomer (A) in this embodiment is preferably a monofunctional acrylic monomer, which results in the resulting cyclodextrin polymer P having no branched structure and excellent solvent solubility.

[0036] The acrylic monomer (A) preferably contains a (meth)acrylic acid ester. One (meth)acrylic acid ester may be used alone, or two or more (meth)acrylic acid esters may be used in combination. In this specification, (meth)acrylic acid refers to both acrylic acid and methacrylic acid. The same applies to other similar terms.

[0037] Examples of (meth)acrylic acid esters include (meth)acrylic acid alkyl esters having a linear or branched alkyl group, (meth)acrylic acid esters having a cyclic structure, (meth)acrylic acid esters having a functional group such as a hydroxyl group, etc. Among these, firstly, (meth)acrylic acid alkyl esters having a linear or branched alkyl group are preferred, and secondly, (meth)acrylic acid esters having a cyclic structure are preferred.

[0038] From the viewpoint of self-adhesiveness, the (meth)acrylic acid alkyl ester is preferably a (meth)acrylic acid alkyl ester in which the alkyl group has a carbon number of 1 to 20. Examples of (meth)acrylic acid alkyl esters in which the alkyl group has a carbon number of 1 to 20 include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, myristyl (meth)acrylate, palmityl (meth)acrylate, and stearyl (meth)acrylate. Among these, from the viewpoint of solvent solubility, (meth)acrylic acid esters having an alkyl group with 1 to 8 carbon atoms are preferred, (meth)acrylic acid esters having an alkyl group with 1 to 6 carbon atoms are more preferred, (meth)acrylic acid esters having an alkyl group with 1 to 4 carbon atoms are particularly preferred, and (meth)acrylic acid esters having an alkyl group with 1 to 2 carbon atoms are even more preferred. Specifically, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, etc. are preferred, and methyl (meth)acrylate or ethyl (meth)acrylate are particularly preferred, with methyl acrylate being even more preferred.

[0039] The content of the (meth)acrylic acid alkyl ester in the acrylic monomer (A) is preferably 50 to 100 mass%, more preferably 60 to 100 mass%, particularly preferably 70 to 100 mass%, further preferably 80 to 100 mass%, and especially preferably 90 to 100 mass%, which further enhances the above-mentioned effects.

[0040] Examples of (meth)acrylic acid esters having a cyclic structure include (meth)acrylic acid esters having an alicyclic structure, (meth)acrylic acid esters having an aromatic ring structure, and (meth)acrylic acid esters having a heterocyclic structure. Specific examples include cyclohexyl (meth)acrylate, benzyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (meth)acrylic acid imide, and phenoxyethyl (meth)acrylate. Among these, (meth)acrylic acid esters having a heterocyclic structure are preferred from the viewpoints of reducing the viscosity of the mixed solution and enhancing hydrogen bonding with paper fibers, and (meth)acrylic acid esters having a heterocyclic structure containing an oxygen atom as a ring-constituting atom are particularly preferred. Specific examples include tetrahydrofurfuryl (meth)acrylate, and particularly tetrahydrofurfuryl acrylate. The use of such bulky (meth)acrylic acid esters can reduce the viscosity of the liquid (mixed solution) to be impregnated into the core material.

[0041] The content of the (meth)acrylic acid ester having the cyclic structure in the acrylic monomer (A) is preferably 50 to 100 mass%, more preferably 60 to 100 mass%, particularly preferably 70 to 100 mass%, further preferably 80 to 100 mass%, and especially preferably 90 to 100 mass%, which further enhances the above-mentioned effects.

[0042] The acrylic monomer (A) may contain an acrylic monomer other than the above-mentioned monomers, for example, an acrylic monomer having a reactive group.

[0043] The content of the component derived from the acrylic monomer (A) in the cyclodextrin polymer P is preferably 50 to 99.9 mass%, more preferably 60 to 99.7 mass%, particularly preferably 70 to 99.5 mass%, and even more preferably 80 to 99.3 mass%, thereby further improving the above-mentioned effects.

[0044] (1-2) Polymerizable cyclodextrin compound (Bp) The cyclodextrin moiety of the polymerizable cyclodextrin compound (Bp) in this embodiment is preferably α-cyclodextrin, β-cyclodextrin, or γ-cyclodextrin, which may have a substituent. Among these, β-cyclodextrin is preferred, and substituted β-cyclodextrin is particularly preferred, from the viewpoint of more easily achieving the above-mentioned effects.

[0045] The substituent is a group obtained by substituting a hydroxyl group of cyclodextrin. Examples of the substituent include an acyl group, an alkyl group, a trityl group, a tosyl group, a trimethylsilane group, a phenyl group, a polyester chain, an oxyethylene chain, an alkyl chain, an ether chain, an ester chain, an acrylic ester chain, etc. Among these, an acyl group is preferred, and an acetyl group is particularly preferred, from the viewpoint of more easily achieving the above-mentioned effects.

[0046] In the polymerizable cyclodextrin compound (Bp), it is preferable that no hydroxyl groups remain in the cyclodextrin, and it is preferable that all hydroxyl groups in the cyclodextrin other than those in the portion having the polymerizable group are substituted with acyl groups, particularly acetyl groups.

[0047] The polymerizable group of the polymerizable cyclodextrin compound (Bp) is not particularly limited as long as it can polymerize with the acryloyl group of the acrylic monomer (A), but is preferably a group containing a polymerizable unsaturated double bond, and more preferably an ethylenically unsaturated group. Specifically, a (meth)acryloyl group, a vinyl group, an allyl group, or the like is preferred, and a (meth)acryloyl group is particularly preferred. The (meth)acryloyl group may also be a functional group derived from (meth)acrylamide. That is, the polymerizable cyclodextrin compound (Bp) is preferably modified with (meth)acrylamide.

[0048] The polymerizable cyclodextrin compound (Bp) preferably has one polymerizable group per cyclodextrin molecule, which allows the copolymer of the acrylic monomer (A) and the polymerizable cyclodextrin compound (Bp) to have no branched structure and has excellent solvent solubility.

[0049] From the above viewpoint, the content of the cyclodextrin compound having two or more polymerizable groups per molecule in the cyclodextrin compound is preferably as low as possible, specifically, 0.1% by mass or less, more preferably 0.01% by mass or less, and even more preferably 0.001% by mass or less.

[0050] The polymerizable cyclodextrin compound (Bp) in this embodiment is preferably a compound represented by the following formula (1). [ka] (R in the above formula (1) 1 represents a hydrogen atom or a methyl group. 2 represents O, NH, a hydrocarbon containing O, a hydrocarbon containing NH, or a hydrocarbon containing O and NH. CD represents α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, or a derivative thereof.

[0051] Examples of the "hydrocarbon containing NH" mentioned above, assuming that the right side is bonded to CD, include -CH2-NH-CH2-, -NH-CH2-O-CH2-, -O-CH2-NH-CH2-, -CH2-NH-CH2-O-, -O-CH2-NH-CH2-O-, -CH2-O-CO-NH-CH2-O-, -CH2-O-CO-NH-C2H4-O-, etc. Among the above, -NH-CH2-O-CH2- is particularly preferred from the viewpoint of easily satisfying the above-mentioned physical properties.

[0052] CD in the above formula (1) is preferably a derivative of β-cyclodextrin, and in particular, a derivative in which the hydroxyl group of cyclodextrin is R 2 It is preferable that the β-cyclodextrin derivative is a β-cyclodextrin derivative in which all the parts except for the part that binds to the β-cyclodextrin are substituted with acyl groups, particularly acetyl groups.

[0053] The weight average molecular weight (Mw) of the polymerizable cyclodextrin compound (Bp) is preferably 100 to 5000, more preferably 300 to 4000, particularly preferably 600 to 3500, and even more preferably 800 to 3000. This improves the above-mentioned effects, particularly water resistance. The weight average molecular weight in this specification is a value measured by gel permeation chromatography (GPC) in terms of standard polystyrene.

[0054] From the viewpoint of production and procurement, the polymerizable cyclodextrin compound (Bp) is preferably a monomer or a dimer.

[0055] The content of the polymerizable cyclodextrin compound (Bp)-derived component in the cyclodextrin polymer P according to the present embodiment (the total amount of polymerizable cyclodextrin compounds (Bp) used in the production of the cyclodextrin polymer P) is preferably 0.05 to 10, more preferably 0.1 to 6, particularly preferably 0.2 to 3, even more preferably 0.4 to 2, and especially preferably 0.5 to 1.5, expressed as a molar ratio relative to 100 mol of the content of the acrylic monomer (A)-derived component (the total amount of acrylic monomer (A) used in the production of the cyclodextrin polymer P). This further enhances the effects described above, particularly improving water resistance.

[0056] (1-3) Non-polymerizable cyclodextrin compounds (Bn) In this embodiment, the cyclodextrin portion of the non-polymerizable cyclodextrin compound (Bn) is preferably α-cyclodextrin, β-cyclodextrin, or γ-cyclodextrin, and is particularly preferably β-cyclodextrin, which provides the above-mentioned effects more effectively.

[0057] The non-polymerizable cyclodextrin compound (Bn) is preferably a cyclodextrin derivative having a substituent other than the polymerizable functional group, the substituent being a non-hydrophilic group. Examples of the non-hydrophilic group include an acyl group, an alkyl group, and an alkoxy group. Among these, an acyl group is preferred, and an acetyl group is particularly preferred. This provides excellent water resistance.

[0058] In the non-polymerizable cyclodextrin compound (Bn), it is preferable that no hydroxyl groups remain in the cyclodextrin, and it is particularly preferable that all of the hydroxyl groups in the cyclodextrin are substituted with acyl groups, especially acetyl groups. Specifically, peracetylated cyclodextrin is preferred, and peracetylated β-cyclodextrin is particularly preferred. This provides better water resistance.

[0059] The weight average molecular weight (Mw) of the non-polymerizable cyclodextrin compound (Bn) is preferably 100 to 4500, more preferably 300 to 3500, particularly preferably 600 to 3000, and further preferably 800 to 2500. This can result in better water resistance.

[0060] (1-4) Photopolymerization initiator (C) When ultraviolet light is used as the active energy ray for copolymerizing the acrylic monomer (A) with the polymerizable cyclodextrin compound (Bp) or for polymerizing the acrylic monomer (A), it is preferable to further use a photopolymerization initiator (C). By using the photopolymerization initiator (C), the acrylic monomer (A) can be efficiently copolymerized without remaining in the system, and the polymerization and curing time and the exposure dose of the active energy ray can be reduced.

[0061] Examples of such photopolymerization initiators (C) include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxycyclohexyl phenyl ketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, Examples of the benzophenone include 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyl dimethyl ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo[2-hydroxy-2-methyl-1[4-(1-methylvinyl)phenyl]propanone], 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide, bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide, etc. These may be used alone or in combination of two or more.

[0062] The amount of the photopolymerization initiator (C) used is preferably 0.001 to 10, more preferably 0.01 to 1, and even more preferably 0.02 to 0.5, particularly preferably 0.05 to 0.3, and even more preferably 0.1 to 0.2, in terms of a molar ratio relative to 100 mol of the total amount of the acrylic monomer (A) and the polymerizable cyclodextrin compound (Bp). This allows the cyclodextrin polymer P to be obtained satisfactorily.

[0063] (2) Method for producing cyclodextrin polymer P The cyclodextrin polymer P is produced by copolymerizing an acrylic monomer (A) with a polymerizable cyclodextrin compound (Bp), and it is particularly preferable to produce the polymer by copolymerization in the absence of a solvent. Three production methods are described below.

[0064] The first manufacturing method is a method in which the acrylic monomer (A) and the polymerizable cyclodextrin compound (Bp) are all cured at once. Specifically, a mixed liquid containing the entire amount of the acrylic monomer (A), the entire amount of the polymerizable cyclodextrin compound (Bp), and optionally a photopolymerization initiator (C) is impregnated into a core material and cured. According to this first manufacturing method, the viscosity of the resulting mixed liquid is low, making it easier to impregnate the core material.

[0065] The mixed liquid can be cured by irradiation with active energy rays or by heat treatment, and is preferably cured by irradiation with active energy rays.

[0066] The active energy ray refers to an electromagnetic wave or a charged particle beam that has an energy quantum, and specific examples thereof include ultraviolet rays, electron beams, etc. Among active energy rays, ultraviolet rays are particularly preferred because they are easy to handle.

[0067] The ultraviolet irradiation can be performed using a high-pressure mercury lamp, a Heraeus H lamp, a xenon lamp, or the like, and the amount of ultraviolet irradiation is set to an illuminance of 50 to 1000 mW / cm. 2 The light intensity is preferably 50 to 10,000 mJ / cm 2 is preferably 100 to 7000 mJ / cm 2 More preferably, it is 200 to 4000 mJ / cm 2 On the other hand, the electron beam irradiation can be carried out by an electron beam accelerator or the like, and the irradiation dose of the electron beam is preferably 10 to 1000 krad.

[0068] The heating temperature for the heat treatment is preferably 60 to 150° C., and particularly preferably 80 to 120° C. The heating time for the heat treatment is preferably 10 seconds to 10 minutes, and particularly preferably 30 seconds to 5 minutes. This heat treatment can also serve as a drying treatment after application of the mixed liquid.

[0069] In producing the cyclodextrin polymer P, the heat treatment may be followed by irradiation with active energy rays, or both treatments may be carried out simultaneously.

[0070] The second production method includes at least the steps of curing a polymerizable cyclodextrin compound (Bp) to obtain a primary cured product (syrup), mixing an acrylic monomer (A), the polymerizable cyclodextrin compound (Bp), and the primary cured product to obtain a secondary mixture, and curing the secondary mixture to obtain a secondary cured product. In the step of obtaining the primary cured product, preferably, a primary mixture containing the acrylic monomer (A) together with the polymerizable cyclodextrin compound (Bp) is cured.

[0071] In the case of the second manufacturing method described above, the viscosity of the resulting mixture generally tends to be high. However, by using a bulky monomer, for example, a monomer having a cyclic structure (particularly a heterocyclic structure) such as tetrahydrofurfuryl acrylate, as the acrylic monomer (A), the viscosity of the resulting mixture (secondary mixture) can be kept low, making it easier to impregnate the core material.

[0072] First, a primary mixture containing a predetermined amount of polymerizable cyclodextrin compound (Bp) and, optionally, predetermined amounts of acrylic monomer (A), photopolymerization initiator (C), etc. is prepared, and the primary mixture is cured to form a primary cured product (syrup). Next, the remaining amount of acrylic monomer (A), the remaining amount of polymerizable cyclodextrin compound (Bp), the primary cured product, and, optionally, photopolymerization initiator (C), etc. are mixed to obtain a secondary mixture (secondary mixed liquid). This secondary mixture (secondary mixed liquid) is impregnated into a core material and cured.

[0073] The amount of the polymerizable cyclodextrin compound (Bp) to be blended when the primary mixture is prepared is preferably 1 mol% or more, more preferably 5 mol% or more, particularly preferably 15 mol% or more, and even more preferably 30 mol% or more, and the upper limit is preferably 100 mol% or less, based on the total amount (100 mol%) of the polymerizable cyclodextrin compound (Bp). The amount of the acrylic monomer (A) to be blended when the primary mixture is prepared is preferably 0 to 80 mol%, particularly preferably 10 to 60 mol%, and even more preferably 20 to 50 mol%, based on the total amount (100 mol%) of the acrylic monomer (A).

[0074] The method for curing the primary mixture and the secondary mixture is the same as in the first manufacturing method described above, except that in curing the primary mixture, the amount of ultraviolet light irradiation is set to an illuminance of 50 to 1000 mW / cm. 2 The light intensity is preferably 200 to 10,000 mJ / cm 2 is preferably 500 to 8000 mJ / cm 2 In addition, in curing the secondary mixture, the amount of ultraviolet light to be irradiated is preferably 50 to 1000 mW / cm. 2 The light intensity is preferably 200 to 20,000 mJ / cm 2 is preferably 500 to 10,000 mJ / cm 2 It is particularly preferred that:

[0075] The third production method includes a step of curing one or more acrylic monomers (A) to obtain a primary cured product, a step of mixing at least a polymerizable cyclodextrin compound (Bp) and the primary cured product to obtain a secondary mixture, and a step of curing the secondary mixture to obtain a secondary cured product. In the step of obtaining the secondary mixture, the acrylic monomer (A) is preferably mixed with the polymerizable cyclodextrin compound (Bp) and the primary cured product to obtain a secondary mixture.

[0076] First, a primary mixture containing a predetermined amount of acrylic monomer (A) and, optionally, a photopolymerization initiator (C) and the like is prepared. In the third manufacturing method, the polymerizable cyclodextrin compound (Bp) is not added at this time. The primary mixture is then cured to form a primary cured product (syrup). Next, the remaining amount of acrylic monomer (A), the polymerizable cyclodextrin compound (Bp), the primary cured product, and, optionally, a photopolymerization initiator (C) and the like are mixed to obtain a secondary mixture (secondary mixed liquid). This secondary mixture (secondary mixed liquid) is impregnated into a core material and cured.

[0077] The amount of the acrylic monomer (A) to be blended when preparing the primary mixture is preferably 5 to 80 mol %, more preferably 10 to 60 mol %, and even more preferably 20 to 50 mol %, relative to the total amount (100 mol %) of the acrylic monomer (A).

[0078] The method for curing the primary mixture and the secondary mixture is the same as in the second manufacturing method described above.

[0079] (3) Method for producing a mixture of an acrylic polymer (AP) and a non-polymerizable cyclodextrin compound (Bn) A mixture of an acrylic polymer (AP) and a non-polymerizable cyclodextrin compound (Bn) can be produced in the same manner as in the above-mentioned method for producing cyclodextrin polymer P, except that the non-polymerizable cyclodextrin compound (Bn) is used instead of the polymerizable cyclodextrin compound (Bp).

[0080] Alternatively, the acrylic polymer (AP) may be produced by polymerizing the acrylic monomer (A), and then the acrylic polymer (AP) may be mixed with the non-polymerizable cyclodextrin compound (Bn). In this case, the acrylic polymer (AP) may be produced by solventless polymerization or solution polymerization.

[0081] The blending amount of the polymerizable cyclodextrin compound (Bp) is preferably 0.05 to 10, more preferably 0.1 to 6, particularly preferably 0.2 to 3, even more preferably 0.4 to 2, and especially preferably 0.5 to 1.5, in terms of a molar ratio relative to 100 mol of the content of components derived from the acrylic polymer (AP) (the total amount of acrylic monomers (A) used during polymerization of the acrylic polymer (AP)). This makes the above-mentioned effects more excellent, and in particular, makes water resistance more excellent.

[0082] (4) Impregnation amount (basis weight) of the impregnated material The impregnation amount (basis weight) of the impregnated material containing a cyclodextrin compound in the water-resistant substrate according to this embodiment is 5 to 150 g / m 2 It is preferable that the density is 8 to 120 g / m 2 It is more preferable that the density is 10 to 100 g / m 2 It is preferable that the density is 20 to 80 g / m 2 This is preferable. This results in better water resistance. Furthermore, when the cyclodextrin compound is a polymer, strong paper strength is obtained, and the paper exhibits good solvent solubility, making it more recyclable, and furthermore, it can also have better thermal adhesiveness. In addition, the "impregnated material" is preferably the above-mentioned cyclodextrin polymer P, or a mixture of an acrylic polymer (AP) and a non-polymerizable cyclodextrin compound (Bn).

[0083] 2. Manufacturing method To produce the water-resistant substrate according to this embodiment, the core material is impregnated with a liquid containing a cyclodextrin compound or a precursor of the cyclodextrin compound (particularly the cyclodextrin polymer P), and then, if necessary, is subjected to a heat treatment or active energy ray irradiation under the conditions described above.

[0084] The impregnation method is not particularly limited, and any known method can be used. For example, impregnation can be carried out using a size press during the papermaking process, or using an impregnation machine after papermaking.

[0085] 3. Physical Properties (1)Basic weight The basis weight of the water-resistant substrate according to this embodiment is 11 to 300 g / m 2 It is preferable that the density is 15 to 200 g / m 2 It is more preferable that the density is 20 to 150 g / m 2 It is preferable that the density is 30 to 100 g / m 2 It is preferable that the density is 40 to 80 g / m 2 This results in better water resistance. Furthermore, when the cyclodextrin compound impregnated into the core material is a polymer, strong paper strength is obtained and good solvent solubility is exhibited, resulting in better recyclability.

[0086] (2) Weight loss rate When the water-resistant substrate according to this embodiment is immersed in ethyl acetate for 1 hour, the weight loss rate calculated by the following formula is preferably 20% or more, more preferably 25% or more, particularly preferably 30% or more, even more preferably 40% or more, and most preferably 50% or more. This results in excellent solvent solubility, which allows for easy separation and recovery of the cyclodextrin compound (polymer) from the core material, resulting in excellent recyclability. The weight loss rate measurement method used in this specification is as shown in the test examples described below. Weight loss rate (%) = [{(weight of water-resistant substrate before immersion - weight of core material before immersion) - (weight of water-resistant substrate after immersion - weight of core material after immersion)} / (weight of water-resistant substrate before immersion - weight of core material before immersion)] x 100

[0087] The upper limit of the weight loss rate is not particularly limited, but is preferably 100% or less, more preferably 98% or less, particularly preferably 96% or less, and even more preferably 94% or less.

[0088] (3) Tear strength The tear strength of the water-resistant substrate according to this embodiment, measured by the trouser tear method at a test speed of 10 mm / min, is preferably 0.1 N or more, more preferably 0.15 N or more, particularly preferably 0.2 N or more, and even more preferably 0.4 N or more. This provides favorable paper strength, making it suitable for, for example, product tags. The tear strength is also preferably 5 N or less, more preferably 3 N or less, particularly preferably 2 N or less, and even more preferably 1 N or less. This results in improved solvent solubility and therefore recyclability. The detailed method for measuring tear strength in this specification is as shown in the test examples described below.

[0089] (4) Maximum load The maximum load (L1) measured for a water-resistant substrate (10 mm wide) according to this embodiment, when subjected to a tensile test with a measurement length of 10 mm and a tensile speed of 100 mm / min, is preferably 0.5 N or more, more preferably 1 N or more, particularly preferably 1.6 N or more, and even more preferably 2.1 N or more. This provides favorable paper strength, making it suitable for use in, for example, product tags. Furthermore, the maximum load (L1) is preferably 100 N or less, more preferably 70 N or less, particularly preferably 40 N or less, even more preferably 25 N or less, and especially preferably 10 N or less. This results in improved solvent solubility and, ultimately, recyclability. The detailed method for measuring the maximum load in this specification is as shown in the test examples described below.

[0090] The maximum load (L2) measured by immersing a water-resistant substrate (10 mm wide) according to this embodiment in water for 10 minutes and then conducting a tensile test in the same manner as above is preferably 0.5 N or more, more preferably 0.8 N or more, particularly preferably 1.2 N or more, even more preferably 1.6 N or more, and of these, preferably 1.8 N or more. This provides excellent water resistance and allows the paper to exhibit favorable paper strength even after immersion in water. Furthermore, the maximum load (L2) is preferably 50 N or less, more preferably 30 N or less, particularly preferably 20 N or less, and even more preferably 10 N or less. This results in improved solvent solubility and, ultimately, recyclability.

[0091] The absolute value of the maximum load change rate (%) calculated by the following formula based on the maximum load (L1) and maximum load (L2) is preferably less than 100%, more preferably 50% or less, and particularly preferably 25% or less. This provides excellent water resistance, and the paper exhibits favorable paper strength even after immersion in water. The absolute value of the maximum load change rate (%) is also preferably 0% or more, more preferably 1% or more, and particularly preferably 2% or more. This provides excellent solvent solubility and, therefore, recyclability. Maximum load change rate (%) = {(L1-L2) / L1} x 100

[0092] (5) Maximum load elongation The maximum load elongation (E1) measured by a tensile test using a water-resistant substrate (10 mm wide) according to this embodiment with a measurement length of 10 mm and a tensile speed of 100 mm / min is preferably 10% or more, more preferably 25% or more, particularly preferably 50% or more, and even more preferably 75% or more. This provides favorable paper strength, making it suitable for use in, for example, product tags. Furthermore, the maximum load elongation (E1) is preferably 300% or less, more preferably 200% or less, particularly preferably 150% or less, and even more preferably 120% or less. This results in improved solvent solubility and, ultimately, recyclability. The detailed method for measuring the maximum load elongation in this specification is as shown in the test examples described below.

[0093] The water-resistant substrate (10 mm wide) according to this embodiment is immersed in water for 10 minutes, and then the maximum load elongation (E2) measured by conducting a tensile test in the same manner as above is preferably 10% or more, more preferably 25% or more, particularly preferably 50% or more, and even more preferably 75% or more. This allows the substrate to have excellent water resistance, and even after immersion in water, the substrate exhibits favorable paper strength. Furthermore, the maximum load elongation (E2) is preferably 300% or less, more preferably 200% or less, particularly preferably 150% or less, and even more preferably 120% or less. This results in superior solvent solubility and, ultimately, recyclability.

[0094] The absolute value of the maximum load elongation change rate (%) calculated by the following formula based on the maximum load elongation (E1) and maximum load elongation (E2) is preferably less than 100%, more preferably 50% or less, and particularly preferably 25% or less. This provides excellent water resistance, and favorable paper strength is exhibited even after immersion in water. Furthermore, the absolute value of the maximum load elongation change rate (%) is preferably 0% or more, more preferably 1% or more, and particularly preferably 2% or more. This provides excellent solvent solubility and, therefore, recyclability. Maximum load elongation change rate (%) = {(E1-E2) / E1} x 100

[0095] 4.Applications The water-resistant substrate according to this embodiment can be suitably used in applications requiring water resistance. Examples include product tags, various labels, printed paper, wrapping paper, packaging materials, and building interior materials. Product tags include, for example, tags that have an IC module and wiring and can send and receive data contactlessly via an external reader / writer. In such product tags, the IC module and wiring can be thermally bonded to the water-resistant substrate, and the IC module and wiring can be easily separated and recovered from the resin (cyclodextrin polymer) and fibrous material by dissolving them in a solvent.

[0096] The above-described embodiments have been described to facilitate understanding of the present invention, and are not intended to limit the present invention. Therefore, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0097] In this specification, when it is written "X to Y" (X and Y are any numbers), it means "X or more and Y or less" unless otherwise specified, and also includes the meaning "preferably greater than X" or "preferably smaller than Y." Furthermore, when it is written "X or more" (X is any number), it means "preferably greater than X" unless otherwise specified, and when it is written "Y or less" (Y is any number), it also means "preferably smaller than Y" unless otherwise specified. [Example]

[0098] The present invention will be explained in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0099] [Production Example 1] As the polymerizable cyclodextrin compound (Bp), a polymerizable β-cyclodextrin compound (Bp1) represented by the following formula (2) was produced by the same procedure as in Production Example 6 of WO 2018 / 159791. [ka] (In formula (2), Ac represents an acetyl group.)

[0100] The molecular weight of the polymerizable β-cyclodextrin compound (Bp1) was measured by the method described below, and the weight average molecular weight (Mw) was 2,059.

[0101] [Production Example 2] As the non-polymerizable cyclodextrin compound (Bn), peracetylated β-cyclodextrin represented by the following formula (3) was produced by the following procedure.

[0102] 1.8 g of β-cyclodextrin (Nacalai Tesque) and 47 mg of p-toluenesulfonic acid monohydrate as a catalyst were added to 8.5 ml of isopropenyl acetate as a solvent, and the mixture was reacted for 16 hours at 70° C. The reaction solution was evaporated under reduced pressure, and the resulting solid was washed with a 10% by mass aqueous solution of sodium carbonate, extracted with chloroform, and recrystallized with acetone to obtain 2.5 g of peracetylated β-cyclodextrin (Bn1) as a white solid.

[0103] [ka] (In formula (3), Ac represents an acetyl group.)

[0104] The molecular weight of the peracetylated β-cyclodextrin (Bn1) was measured by the method described below, and the weight average molecular weight (Mw) was 1,460.

[0105] Example 1 1. Preparation of Mixture Methyl acrylate as the acrylic monomer (A), the polymerizable β-cyclodextrin compound (Bp1) produced in Production Example 1, and 1-hydroxycyclohexyl phenyl ketone as the photopolymerization initiator (C) were mixed in the molar ratios shown in Table 1 and thoroughly stirred to obtain a mixed solution.

[0106] 2. Manufacturing of water-resistant substrate A sheet of tissue paper (Daio Paper Co., Ltd., product name "Elleair i:na") as a core and a 0.1 mm thick PET film as a spacer were placed on the release-treated surface of the release film (the core and spacer did not overlap). Another release film was then placed on top of the core and spacer, with its release-treated surface facing the core and spacer. In this way, the core was placed in the gap (0.1 mm) between the two release films.

[0107] Next, the mixed solution obtained in step 1 above was poured into the gap between the release films containing the core material in an amount sufficient for the core material to impregnate the core material with the mixed solution. After that, active energy rays (ultraviolet rays; UV) were irradiated under the following conditions to cure the mixed solution impregnated into the core material, thereby obtaining a water-resistant substrate.

[0108] <Activated energy ray irradiation conditions> -High pressure mercury lamp used ·Illuminance 200mW / cm 2 ,Light intensity 2000mJ / cm 2 The UV illuminance and light intensity meter used is the "UVPF-A1" manufactured by Eye Graphics.

[0109] [Example 2, Comparative Example 2] Water-resistant substrates were produced in the same manner as in Example 1, except that the type and amount of cyclodextrin compound were changed as shown in Table 1.

[0110] Example 3 1. Preparation of Mixture Tetrahydrofurfuryl acrylate as the acrylic monomer (A), the polymerizable β-cyclodextrin compound (Bp1) produced in Production Example 1, and 1-hydroxycyclohexyl phenyl ketone as the photopolymerization initiator (C) were mixed and thoroughly stirred to obtain a primary mixed solution.

[0111] The primary mixed solution was irradiated with active energy rays (ultraviolet rays; UV) under the following conditions to obtain a primary cured product (syrup).

[0112] <Activated energy ray irradiation conditions> -High pressure mercury lamp used ·Illuminance 60mW / cm 2 ,Light intensity 2000mJ / cm 2 The UV illuminance and light intensity meter used is the "UVPF-A1" manufactured by Eye Graphics.

[0113] Next, the primary cured product obtained above was mixed with tetrahydrofurfuryl acrylate as the acrylic monomer (A) and 1-hydroxycyclohexylphenyl ketone as the photopolymerization initiator (C) and stirred thoroughly to obtain a secondary mixed solution. The final blending ratio (molar ratio) of each component is as shown in Table 1.

[0114] 2. Manufacturing of water-resistant substrate A sheet of tissue paper (manufactured by Daio Paper Co., Ltd., product name "Elleair i:na") as a core material and a PET film (0.1 mm thick) as a spacer were placed on the release-treated surface of the release film (the core material and spacer did not overlap). Next, the secondary mixed liquid obtained in step 1 above was dripped onto the core material in an amount sufficiently large relative to the core material. Next, another release film was placed on top of the core material and spacer, with its release-treated surface facing the core material and spacer, and a rubber roller was rolled back and forth twice over the release film. In this way, the core material placed in the gap (0.1 mm) between the two release films was impregnated with the secondary mixed liquid.

[0115] Thereafter, the secondary mixed liquid impregnated into the core material was cured by irradiation with active energy rays (ultraviolet rays; UV) under the following conditions, thereby obtaining a water-resistant substrate.

[0116] <Activated energy ray irradiation conditions> -High pressure mercury lamp used ·Illuminance 60mW / cm 2 ,Light intensity 2000mJ / cm 2 The UV illuminance and light intensity meter used is the "UVPF-A1" manufactured by Eye Graphics.

[0117] [Example 4, Comparative Example 1] Water-resistant substrates were produced in the same manner as in Example 3, except that the type and amount of cyclodextrin compound were changed as shown in Table 1.

[0118] Comparative Example 3 The tissue paper used as the core material in the examples was used as the water-resistant substrate in Comparative Example 3. Note that even if the tissue paper is not water-resistant, it will be referred to as a "water-resistant substrate" here for convenience. The same applies to the other comparative examples.

[0119] Comparative Example 4 Copy paper (1 sheet) (sold by Plus Jointex Company, product name "Copy Paper J2 Neutral Paper") was used as the water-resistant substrate of Comparative Example 4.

[0120] Details of the abbreviations and other information listed in Table 1 are as follows: [Acrylic Monomer (A)] MA: methyl acrylate THF-A: tetrahydrofurfuryl acrylate HDA: 1,6-hexanediol diacrylate [Polymerizable cyclodextrin compound (Bp)] Bp1: Polymerizable β-cyclodextrin compound (Production Example 1) [Non-polymerizable cyclodextrin compounds (Bn)] Bn1: Peracetylated β-cyclodextrin (Production Example 2)

[0121] The weight average molecular weight (Mw) of the cyclodextrin compound is a weight average molecular weight measured in terms of polystyrene using gel permeation chromatography (GPC) under the following conditions (GPC measurement). <Measurement conditions> GPC measuring device: Tosoh HLC-8020 GPC columns (passed in the following order): Tosoh Corporation TSK guard column HXL-H TSK gel GMHXL (×2) TSK gel G2000HXL Measurement solvent: tetrahydrofuran ·Measurement temperature: 40℃

[0122] [Test Example 1] (Measurement of basis weight) The basis weight (= the content of paper fibers in the water-resistant substrate) of the core material used in the examples and comparative examples (g / m 2 ), and the basis weight (g / m ) of the water-resistant substrates of the examples and comparative examples. 2 ) was measured using a precision electronic balance (manufactured by A&D Co., Ltd., model number: GR-200). The results are shown in Table 1.

[0123] In addition, the water-resistant substrates of the examples and comparative examples were punched with a hole punch having a diameter of 8 mm to prepare circular samples. The mass (mg) of the samples was measured, and the 8 mm diameter circle and 1 m diameter circle were measured. 2 Using the ratio of the areas of 1m 2 Then, the basis weight of the core material was subtracted from this value to obtain the basis weight of the impregnated material (g / m 2 The results are shown in Table 1.

[0124] [Test Example 2] (Measurement of tear strength) Samples measuring 20 mm wide x 100 mm long were cut out from the water-resistant substrates of the Examples and Comparative Examples. The samples were set in a tensile tester (manufactured by Orientec Co., Ltd., product name "Tensilon") so that the sample measurement area was 20 mm wide x 50 mm long, and the tear strength (N) was measured using the tensile tester at a test speed of 10 mm / min by the trouser tear method under an environment of 23°C and 50% RH. The results are shown in Table 2.

[0125] [Test Example 3] (Tensile test / evaluation of water resistance) Samples measuring 10 mm wide x 75 mm long were cut out from the water-resistant substrates of the Examples and Comparative Examples. The samples were set in a tensile tester (manufactured by Orientec Co., Ltd., product name "Tensilon") so that the sample measurement area was 10 mm wide x 10 mm long, and elongated at a tensile speed of 200 mm / min using the tensile tester under an environment of 23°C and 50% RH. The samples were elongated until they broke, and the maximum load (N; L1) and maximum load elongation (%; E1) were measured. The results are shown in Table 2.

[0126] On the other hand, the above sample was immersed in water for 10 minutes. After that, the maximum load (N; L2) and maximum load elongation (%; E2) of the sample were measured in the same manner as above. The results are shown in Table 2.

[0127] Based on the maximum load (L1) measured above and the maximum load after water immersion (L2), the absolute value of the maximum load change rate (%) was calculated using the following formula. The results are shown in Table 2. Maximum load change rate (%) = {(L1-L2) / L1} x 100

[0128] The water resistance was evaluated based on the calculated absolute value of the maximum load change rate (%) according to the following criteria. The results are shown in Table 2. ◎...The absolute value of the maximum load change rate is 0% or more and less than 25% ○...The absolute value of the maximum load change rate is 25% or more and less than 50% △: Absolute value of maximum load change rate is 50% or more and less than 100% ×...The absolute value of the maximum load change rate is 100% or more

[0129] Furthermore, based on the maximum load elongation (E1) and the maximum load elongation after water immersion (E2) measured above, the absolute value of the maximum load elongation change rate (%) was calculated using the following formula. The results are shown in Table 2. Maximum load elongation change rate (%) = {(E1-E2) / E1} x 100

[0130] The water resistance was evaluated based on the calculated absolute value of the maximum load elongation change rate (%) according to the following criteria. The results are shown in Table 2. ◎...The absolute value of the maximum load elongation change rate is 0% or more and less than 25% 〇: Absolute value of maximum load elongation change rate is 25% or more and less than 50% △: Absolute value of maximum load elongation change rate is 50% or more and less than 100% ×...The absolute value of the maximum load elongation change rate is 100% or more

[0131] Furthermore, the water resistance was evaluated based on the maximum load change rate and the maximum load elongation change rate, with ⊚ being given 3 points, ◯ being given 2 points, △ being given 1 point, and × being given 0 point. The sum of the scores for the water resistance evaluation based on the maximum load change rate and the maximum load elongation change rate were calculated, and an overall evaluation of water resistance was made based on the following criteria. The results are shown in Table 2. A: The sum is 5 or more points B…Sum is 4 points C...Sum is 3 points D...sum is 2 points or less

[0132] Test Example 4 (Measurement of Weight Loss Rate) Samples measuring 50 mm wide x 50 mm long were cut from the core materials used in the Examples and Comparative Examples, and the water-resistant substrates of the Examples and Comparative Examples, and their weights (mg) were measured. The samples were then immersed in ethyl acetate for 1 hour, thoroughly dried, and their weights (mg) were measured. Based on these measurement results, the weight loss rate (%) was calculated using the following formula. The results are shown in Table 2. Weight loss rate (%) = [{(weight of water-resistant substrate before immersion - weight of core material before immersion) - (weight of water-resistant substrate after immersion - weight of core material after immersion)} / (weight of water-resistant substrate before immersion - weight of core material before immersion)] x 100

[0133] The greater the weight loss rate, the more the cyclodextrin polymer dissolves and elutes from the core material, and the more excellent the solvent solubility and, in turn, the more recyclable the material is.

[0134] [Test Example 5] (Evaluation of Wiring Recovery) Three strips of aluminum foil, 1 mm wide and 20 mm long, were prepared as wiring and placed at 1 cm intervals on the water-resistant substrates of the Examples and Comparative Examples. The same water-resistant substrates were placed on top of them with the aluminum foil sandwiched between them, and the wiring was heated to 70°C with a pressure of 20 g / cm. 2 The two water-resistant substrates were thermocompression bonded to each other by applying a load of 1000 kJ / cm2 and leaving the substrates to stand for 10 minutes. This was used as a sample.

[0135] The sample was immersed in ethyl acetate for 24 hours, and then the aluminum foil was removed from the sample. The wire recovery was evaluated according to the following criteria. The results are shown in Table 2. A...Three rolls of aluminum foil were recovered. B...There was some torn aluminum foil, but more than two pieces of aluminum foil were recovered. C...Only one roll or less of aluminum foil was recovered.

[0136] [Test Example 6] (Evaluation of Adhesion) Two sheets of the water-resistant substrates of the Examples and Comparative Examples were stacked together and subjected to a temperature of 23°C at 20 g / cm 2 The water-resistant substrates were pressed together by applying a load of 1000 kJ / s and leaving it to stand for 10 minutes. After 24 hours, a T-peel test was performed at a peel rate of 10 mm / min using a tensile tester (manufactured by Orientec Co., Ltd., product name "Tensilon") in accordance with JIS K6854-3:1999 to examine the relationship (self-adhesion) between interfacial peeling and substrate failure (substrate strength).

[0137] In addition, two sheets of each of the water-resistant substrates of the examples and comparative examples were stacked, and the resulting sheets were subjected to a temperature of 70°C and a pressure of 20 g / cm 2 The water-resistant substrates were thermocompression bonded to each other by applying a load of 1000 kJ / cm2 and leaving the substrates to stand for 10 minutes. After 24 hours, T-peel tests were performed in the same manner as above to examine the relationship (thermal adhesion) between interfacial peeling and substrate failure (substrate strength).

[0138] The self-adhesiveness and thermal adhesiveness were evaluated according to the following criteria, and the results are shown in Table 2. ◯: The adhesive strength was stronger than the strength of the substrate, and the substrate was destroyed. △: The interface peeled off in some places, and the substrate was broken in some places. ×: The adhesive strength was weaker than the strength of the substrate, and interfacial peeling occurred over the entire surface.

[0139] [Test Example 7] (Evaluation of ink adhesion) For the water-resistant substrates of the examples and comparative examples, the total light transmittance (%) was measured using a haze meter (manufactured by Nippon Denshoku Industries Co., Ltd., product name "SH-7000") in accordance with JIS K7361-1:1997.

[0140] A circle with a diameter of 10 mm was drawn on the surface of the above-mentioned water-resistant substrate, and the inside of the circle was filled in black with an oil-based pen (manufactured by Zebra, product name "Maki Black"). The total light transmittance (%; before wiping) of the circle was measured in the same manner as above.

[0141] Next, a nonwoven fabric wiper (manufactured by Asahi Kasei Corporation, product name "Bemcot S-2") was reciprocated 10 times with a load of 250 g to wipe off the black color of the circular area. The total light transmittance (%; after wiping) of the circular area was measured in the same manner as above. The total light transmittance after wiping was then subtracted from the total light transmittance before wiping to calculate the change in total light transmittance. The results are shown in Table 2. The closer this change is to 0, the better the ink application can be evaluated.

[0142] [Test Example 8] (Evaluation of printability) The letters "Aiueo (MS P Gothic 10.5 point)" were printed in black on the water-resistant substrates of the Examples and Comparative Examples using a laser printer (Fujifilm Corporation, product name "Apeos C2570"). The printed area was then rubbed 10 times with copy paper (Plus Jointex Company, product name "Copy Paper J2 Neutral Paper"), and the condition of the printed area and copy paper was then visually inspected, and printability was evaluated according to the following criteria. The results are shown in Table 2. ◎...There was no bleeding in the printed area and no transfer to the copy paper. ○...There was no bleeding in the printed area, but there was some transfer onto the copy paper. ×...The printed part has bled.

[0143] [Table 1]

[0144] [Table 2]

[0145] As can be seen from Table 2, the water-resistant substrates of the Examples were excellent in water resistance, wiring recovery, and printability. The water-resistant substrates of Examples 1 and 2 also had excellent solvent solubility and ink adhesion. Meanwhile, the water-resistant substrates of Examples 3 and 4 also had excellent thermal adhesiveness. [Industrial Applicability]

[0146] The water-resistant substrate according to the present invention is suitable for use in applications requiring water resistance, such as product tags.

Claims

1. A water-resistant substrate comprising a core material made of a fibrous material impregnated with a cyclodextrin compound.

2. The content of the fibrous material is 5 g / m ２ Above, 200g / m ２ 2. The water-resistant substrate according to claim 1, wherein:

3. Basis weight: 11 g / m ２ Above, 300g / m ２ 2. The water-resistant substrate according to claim 1, wherein:

4. 2. The water-resistant substrate according to claim 1, wherein when the water-resistant substrate is immersed in ethyl acetate for 1 hour, the weight loss rate calculated by the following formula is 20% or more. Weight loss rate (%) = [{(weight of water-resistant substrate before immersion - weight of core material before immersion) - (weight of water-resistant substrate after immersion - weight of core material after immersion)} / (weight of water-resistant substrate before immersion - weight of core material before immersion)] x 100

5. 2. The water-resistant substrate according to claim 1, wherein the tear strength measured by a trouser tearing method at a test speed of 10 mm / min is 0.1 N or more.

6. 2. The water-resistant substrate according to claim 1, wherein the maximum load measured in a tensile test on the water-resistant substrate having a width of 10 mm, with a measurement length of 10 mm and a tensile speed of 100 mm / min, is 0.5 N or more.

7. 2. The water-resistant substrate according to claim 1, wherein the water-resistant substrate has a width of 10 mm, is immersed in water for 10 minutes, and then a tensile test is performed on the water-resistant substrate at a measurement length of 10 mm and a tensile speed of 100 mm / min, and the maximum load measured is 0.5 N or more.

8. The water-resistant substrate having a width of 10 mm is subjected to a tensile test at a measurement length of 10 mm and a tensile speed of 100 mm / min, and the maximum load measured is defined as L1 (N). The water-resistant substrate having a width of 10 mm is immersed in water for 10 minutes, and then a tensile test is carried out on the water-resistant substrate at a measurement length of 10 mm and a tensile speed of 100 mm / min. When the maximum load measured is L2 (N), 2. The water-resistant substrate according to claim 1, wherein the absolute value of the maximum load change rate (%) calculated by the following formula is less than 100%. Maximum load change rate (%) = {(L1 - L2) / L1} x 100

9. 2. The water-resistant substrate according to claim 1, wherein the maximum load elongation measured in a tensile test on a 10 mm wide water-resistant substrate at a measurement length of 10 mm and a tensile speed of 100 mm / min is 10% or more.

10. 2. The water-resistant substrate according to claim 1, wherein the water-resistant substrate has a width of 10 mm, is immersed in water for 10 minutes, and then a tensile test is performed on the water-resistant substrate at a measurement length of 10 mm and a tensile speed of 100 mm / min, and the maximum load elongation measured is 10% or more.

11. The water-resistant substrate having a width of 10 mm is subjected to a tensile test at a measurement length of 10 mm and a tensile speed of 100 mm / min, and the maximum load elongation measured is defined as E1 (%). The water-resistant substrate having a width of 10 mm is immersed in water for 10 minutes, and then a tensile test is performed on the water-resistant substrate at a measurement length of 10 mm and a tensile speed of 100 mm / min. When the maximum load elongation measured is E2 (%), 2. The water-resistant substrate according to claim 1, wherein the absolute value of the maximum load elongation change rate (%) calculated by the following formula is less than 100%. Maximum load elongation change rate (%) = {(E1 - E2) / E1} × 100

12. 2. The water-resistant substrate according to claim 1, wherein the cyclodextrin compound is a polymer containing cyclodextrin or a cyclodextrin derivative.

13. 13. The water-resistant substrate according to claim 12, wherein the polymer is a copolymer of a cyclodextrin derivative having a polymerizable group and an acrylic monomer.

14. 2. The water-resistant substrate according to claim 1, wherein the cyclodextrin compound is a non-polymeric cyclodextrin compound having a non-hydrophilic group.

15. 15. The water-resistant substrate according to claim 14, wherein the non-polymeric cyclodextrin compound is impregnated into the core material together with an acrylic polymer.

16. 16. The water-resistant substrate according to claim 1, wherein the fibrous material is paper fiber.

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