WO2024225272A1 - Laminate and method for producing recycled film - Google Patents

Abstract

The purpose of the present invention is to provide a laminate in which a printed layer can be easily removed and that has high weather resistance, and a method for producing a recycled film.　A laminate according to the present invention comprises: a film containing a fluororesin; and a printed layer containing an alkali-soluble resin and a pigment on at least a part of the film. The content of the alkali-soluble resin is 1.0-15.0 mass% with respect to the total mass of the printed layer.

Description

Manufacturing method of laminate and recycled film

The present invention relates to a method for manufacturing a laminate and a recycled film.

Because fluororesin films have excellent weather resistance and stain resistance, they are used as membrane materials (roofing materials, exterior wall materials, etc.) in membrane-structured facilities (sports facilities (swimming pools, gymnasiums, tennis courts, soccer fields, athletics stadiums, etc.), warehouses, assembly halls, exhibition halls, horticultural facilities (horticultural greenhouses, agricultural greenhouses, etc.)), etc.

However, because fluororesin film has a high solar radiation transmittance, when it is used as a membrane material for a membrane structure facility that is exposed to sunlight, the inside of the membrane structure facility may become too bright or the temperature inside the membrane structure facility may become too high. For this reason, paint or ink is printed on the fluororesin film to increase the solar radiation reflectance and reduce the solar radiation transmittance to the interior. In addition, the team colors and logos of the teams using the sports facilities are sometimes printed on the film with paint or ink.

Furthermore, because film materials are often used for long periods of time and outdoors, the paints and inks applied to fluororesin films must be weather resistant.

For example, Patent Document 1 discloses a laminate including a substrate containing a fluoropolymer and a resin film disposed on at least a partial region of the substrate, and the resin film is formed from a composition including aluminum-containing composite particles, a fluoropolymer, and a liquid medium.
Patent Document 2 discloses a non-curable coating film-forming composition to be applied onto a fluororesin substrate, the composition containing a fluorocopolymer and a solvent, the mass average molecular weight (M _w ) of the fluorocopolymer being 30,000 to 60,000, and the average number of moles of specific functional groups per mole of the fluorocopolymer being 33 or more and less than 54.
Patent Document 3 discloses a printing ink containing composite particles having a titanium oxide core and three coating layers, a resin, and a liquid medium.

International Publication No. WO 2015/152170 JP 2006-152061 A International Publication No. 2011/013572

In recent years, there is a growing expectation that fluororesin films having a printed layer printed with these paints or inks will be reused after use. In addition to removing the printed layer from the fluororesin film and reusing it in film form, it is also desirable to melt the film by heat to form pellets, and process it into fluororesin films for other uses or with different shapes such as thicknesses for reuse.

However, the resin components contained in the paint or ink do not have as high heat resistance as the fluororesin film base material, and so become discolored when heated for melting during reprocessing, making it necessary to remove the printed layer from the fluororesin film. In fact, paint or ink that has been subjected to a thermal history of approximately 250-350°C turns black, so if the fluororesin film is melted and reprocessed with the printed layer still attached, the resulting film will have black defects or will be darkly colored overall.

In view of the above circumstances, it is desired that the printed layer in the fluororesin film can be completely removed from the fluororesin film when it is recycled. Methods for removing the printed layer include a method of wiping the printed layer with a cloth or the like soaked in an organic solvent such as acetone, and a method of scraping the printed layer off with a grinder. However, there are cases in which the printed area occupies 20 to 95% of the area of the fluororesin film, and the above-mentioned removal methods are not economical.
Furthermore, since they are often used for long periods of time and outdoors, the printed layer is also required to have excellent weather resistance.

This disclosure was made in light of these circumstances, and aims to provide a laminate with high weather resistance that allows the printed layer to be easily removed, and a method for producing recycled film.

Specific means for achieving the above object are as follows:
<1> A film containing a fluororesin;
a printing layer containing an alkali-soluble resin and a pigment on at least a portion of the film;
The content of the alkali-soluble resin is 1.0 to 15.0% by mass relative to the total mass of the printed layer.
<2> The laminate according to <1>, wherein the printed layer further contains at least one resin selected from the group consisting of fluororesins and (meth)acrylic resins.
<3> The laminate according to <2>, wherein the fluororesin in the printed layer is a copolymer having a fluoroolefin unit and a monomer unit having a hydroxyl group.
<4> The laminate according to any one of <1> to <3>, wherein the alkali-soluble resin has an acid value of 100 to 500 mgKOH/g.
<5> The laminate according to any one of <1> to <4>, wherein the pigment is an aluminum composite particle coated with a (meth)acrylic resin or silica.
<6> The laminate according to any one of <1> to <5>, which is used outdoors.
<7> The laminate according to any one of <1> to <6>, which is at least one material selected from the group consisting of a roofing material, a wall covering material, and a display material.
<8> The laminate according to any one of <1> to <7> is immersed in an alkaline liquid to remove the printed layer, thereby obtaining a recycled film containing a fluororesin.
How recycled film is manufactured.
<9> The laminate according to any one of <1> to <7> is immersed in an alkaline liquid to remove the printed layer, thereby obtaining a film containing the fluororesin,
The obtained film containing the fluororesin is melted and molded to obtain a recycled film containing the fluororesin.
How recycled film is manufactured.

According to one aspect of the present disclosure, it is possible to provide a laminate with high weather resistance and a method for producing recycled film, in which the printed layer can be easily removed.

The following describes in detail the embodiments of the present disclosure. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components (including element steps, etc.) are not essential unless otherwise specified. The same applies to numerical values and their ranges, and do not limit the present disclosure.

In the present disclosure, the numerical ranges indicated using "to" include the numerical values before and after "to" as the minimum and maximum values, respectively.
In the numerical ranges described in the present disclosure in stages, the upper or lower limit value described in one numerical range may be replaced with the upper or lower limit value of another numerical range described in stages. In addition, in the numerical ranges described in the present disclosure, the upper or lower limit value of the numerical range may be replaced with a value shown in the examples.
In the present disclosure, each component may contain multiple types of corresponding substances. When multiple types of substances corresponding to each component are present in the composition, the content or amount of each component means the total content or amount of the multiple substances present in the composition, unless otherwise specified.
In the present disclosure, the particles corresponding to each component may include multiple types of particles. When multiple types of particles corresponding to each component are present in the composition, the particle size of each component means the value for a mixture of the multiple types of particles present in the composition, unless otherwise specified.
In this disclosure, the term "unit" of a polymer refers to a portion derived from a monomer that exists in the polymer and constitutes the polymer. The term "unit" also refers to a unit that is obtained by chemically converting the structure of a unit after the formation of the polymer. In some cases, units derived from individual monomers are referred to by the name of the monomer with "unit" added.
In this disclosure, films and sheets are referred to as "films" regardless of their thickness.
In the present disclosure, "(meth)acrylic" means at least one of acrylic and methacrylic.
In this disclosure, the term "layer" includes cases where the layer is formed over the entire area when the area in which the layer exists is observed, as well as cases where the layer is formed over only a portion of the area.

<Laminate>
The laminate of the present disclosure comprises a film containing a fluororesin and a printed layer containing an alkali-soluble resin and a pigment on at least a portion of the film, wherein the content of the alkali-soluble resin is 1.0 to 15.0 mass% relative to the total mass of the printed layer.

By adopting the above-mentioned constitution, the printed layer can be easily removed and a laminate having high weather resistance can be obtained. The reason for this is not clear, but is presumed to be as follows.
By using a film containing a fluororesin, which has better weather resistance than other resins, the film has excellent weather resistance. By using an alkali-soluble resin in the printed layer, the printed layer can be easily removed. In particular, by making the content of the alkali-soluble resin 1.0% by mass or more relative to the total mass of the printed layer, the printed layer can be easily removed. Furthermore, by making the content of the alkali-soluble resin 15.0% by mass or less relative to the total mass of the printed layer, the printed layer has excellent weather resistance.
In addition, since the printed layer contains a pigment, the laminate provided with the printed layer has a high solar reflectance. Therefore, in a membrane structure facility or the like using the laminate of the present disclosure, the temperature, brightness, and the like inside the facility can be appropriately adjusted.

(Film containing fluororesin)
The laminate of the present disclosure has a film (hereinafter also referred to as "substrate") that contains a fluororesin.
The fluororesin contained in the substrate is preferably one that can be molded into a film, and is preferably one that has excellent weather resistance.
From the above viewpoint, the fluororesin contained in the base material is preferably a homopolymer or copolymer of a fluoroolefin. Examples of the fluoroolefin include the fluoroolefins described below as structural units of the specific fluororesin. The fluororesin may be used alone or in combination of two or more.

Examples of fluoroolefin copolymers include copolymers of two or more fluoroolefins, and copolymers of one or more fluoroolefins with one or more olefins or perfluoro(alkyl vinyl ethers). The fluoroolefins and olefins preferably have 2 or 3 carbon atoms. The perfluoro(alkyl vinyl ether) preferably has 3 to 6 carbon atoms.

Preferred fluororesins include vinyl fluoride polymer (hereinafter also referred to as "PVF"), vinylidene fluoride polymer (hereinafter also referred to as "PVDF"), vinylidene fluoride-hexafluoropropylene copolymer, THV, tetrafluoroethylene-propylene copolymer, tetrafluoroethylene-vinylidene fluoride-propylene copolymer, ethylene-tetrafluoroethylene copolymer (hereinafter also referred to as "ETFE"), hexafluoropropylene-tetrafluoroethylene copolymer (hereinafter also referred to as "FEP"), ethylene-hexafluoropropylene-tetrafluoroethylene copolymer (hereinafter also referred to as "EFEP"), perfluoro(alkyl vinyl ether)-tetrafluoroethylene copolymer (hereinafter also referred to as "PFA"), chlorotrifluoroethylene polymer (hereinafter also referred to as "PCTFE"), and ethylene-chlorotrifluoroethylene copolymer (hereinafter also referred to as "ECTFE"). As the fluororesin, ETFE is particularly preferable.

The fluorine atom content in the fluororesin contained in the substrate is preferably 35% by mass or more, more preferably 40% by mass or more, and even more preferably 45% by mass or more. When the fluorine atom content is equal to or more than the lower limit of the above range, the substrate has better weather resistance, stain resistance, chemical resistance, and non-stickiness, and is particularly excellent in non-stickiness and stain resistance.
The fluorine atom content in the fluororesin contained in the base material is preferably 80% by mass or less, and more preferably 70% by mass or less.
The fluorine atom content in the fluororesin can be determined by combusting the fluororesin and then using a fluoride ion selective electrode in combination with gas chromatography.

The content of the fluororesin is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more, relative to the total mass of the substrate, and may be 100% by mass. If the content of the fluororesin is equal to or greater than the lower limit of the above range, the weather resistance of the substrate will be even more excellent.

The substrate may further contain a non-fluorinated resin, a known additive, etc. Examples of the known additive include a color pigment, a UV absorber, a near-infrared absorbing pigment, and a near-infrared reflective pigment.
Examples of colored pigments include titanium oxide, which is a white pigment, aluminum cobalt oxide, which is a blue pigment, and iron oxide, which is a red pigment.
Examples of the UV absorbent include inorganic UV absorbents, organic UV absorbents, etc. Examples of the inorganic UV absorbent include inorganic particles such as zinc oxide, titanium oxide, cerium oxide, and iron oxide; inorganic composite particles in which the surfaces of the inorganic particles are coated with an inorganic material such as silica, alumina, and zirconia; and the like.
Examples of near-infrared absorbing pigments or near-infrared reflective pigments include boron compounds such as lanthanum hexaboride, tungsten compounds such as cesium tungstate, indium tin oxide, and antimony tin oxide.

The fluorine atom content in the substrate is preferably 27% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and particularly preferably 45% by mass or more. When the fluorine atom content is equal to or more than the lower limit of the above range, the substrate has better weather resistance, stain resistance, chemical resistance, and non-adhesiveness, and is particularly excellent in non-adhesiveness and stain resistance.
The fluorine atom content in the substrate is preferably 70% by mass or less, and more preferably 60% by mass or less.
The fluorine atom content in the substrate is determined by combusting the substrate and then using a fluoride ion selective electrode in combination with gas chromatography.

The substrate preferably has a stress for 10% elongation of 10 MPa or more, more preferably 16 MPa or more. The stress for 10% elongation does not depend on the thickness of the film, but on the composition of the fluororesin. If the stress for 10% elongation is 10 MPa or more, the substrate has excellent snow load resistance and wind pressure resistance.
The stress for 10% elongation of the substrate is preferably 80 MPa or less, and more preferably 50 MPa or less.

In this disclosure, the stress at 10% elongation is determined by the method specified in JIS K7127:1999 (Plastics - Test methods for tensile properties - Part 3: Test conditions for films and sheets). Using dumbbell 5 as the test specimen, the tension when stretched at a tensile speed of 200 mm/min is divided by the cross-sectional area of the film before stretching to calculate.

In the case where the printed layer described later has a light reflecting function, the substrate preferably has light transmittance so as not to inhibit the light reflecting function of the printed layer. The total light transmittance of the substrate is preferably 70% or more, more preferably 85% or more.
The total light transmittance of the substrate is preferably 99.9% or less, and more preferably 98% or less.
In this disclosure, the "total light transmittance" is a value measured in accordance with JIS K7375:2008 "Plastics - Determination of total light transmittance and total light reflectance".

The thickness of the substrate is preferably 25 to 1,000 μm, and more preferably 100 to 500 μm. When the thickness of the substrate is equal to or greater than the lower limit of the above range, the mechanical strength of the substrate is excellent. When the thickness of the substrate is equal to or less than the upper limit of the above range, the optical transparency of the substrate is excellent.

In order to improve the adhesion with the printing layer, the substrate is preferably subjected to a surface treatment for increasing the surface tension on the surface on which the printing layer is formed.By carrying out the surface treatment, polar groups such as formyl groups, carboxy groups, and hydroxyl groups are formed on the surface of the substrate.For example, when the printing layer contains a resin having a hydroxyl group in addition to an alkali-soluble resin, the hydroxyl group of this resin and the polar group formed on the surface of the substrate form a chemical bond, and the adhesion between the substrate and the printing layer is further improved.
Examples of the surface treatment include corona discharge treatment, metallic sodium treatment, mechanical graining treatment, excimer laser treatment, etc. Corona discharge treatment is preferred from the viewpoints of high treatment speed and no need for cleaning after treatment.

The surface tension of the substrate is preferably 0.035 N/m or more, and more preferably 0.04 N/m or more. When the surface tension of the substrate is equal to or greater than the lower limit of the above range, the adhesion between the substrate and the printing layer is even better. There is no particular upper limit to the surface tension of the substrate, but it may be, for example, 0.06 N/m.

(Printing layer)
The laminate of the present disclosure has a printed layer on at least a portion of a substrate. The printed layer contains an alkali-soluble resin and a pigment, and the content of the alkali-soluble resin is 1.0 to 15.0 mass % based on the total mass of the printed layer.

-Alkali-soluble resin-
In the present disclosure, an alkali-soluble resin means a resin that can dissolve 0.1 g or more in 100 mL of a 1.5 mass % aqueous sodium hydroxide solution at 85°C.

From the viewpoint of improving the removability of the printed layer with an alkaline liquid, the acid value of the alkali-soluble resin is preferably 100 mgKOH/g or more, more preferably 150 mgKOH/g or more, and even more preferably 250 mgKOH/g or more.
From the viewpoint of adhesion of the printed layer to the substrate, the acid value of the alkali-soluble resin is preferably 500 mgKOH/g or less, and more preferably 400 mgKOH/g or less.
In the present disclosure, the "acid value" is measured in accordance with JIS K 0070:1992.

The alkali-soluble resins may be used alone or in combination of two or more kinds.
The alkali-soluble resin preferably has an alkali-soluble group such as a phenolic hydroxyl group, a carboxyl group, or an acid anhydride group in the main chain or side chain, and more preferably has a carboxyl group or an acid anhydride group in the main chain or side chain. The alkali-soluble resin preferably has a structural unit derived from at least one selected from the group consisting of a monomer having a phenolic hydroxyl group, a monomer having an acid anhydride group, and a monomer having a carboxyl group, and more preferably has a structural unit derived from at least one selected from the group consisting of a monomer having an acid anhydride group and a monomer having a carboxyl group. The alkali-soluble resin may be a homopolymer of these, a copolymer of these, or a copolymer of these monomers and other monomers.

Examples of the monomer having an acid anhydride group or a carboxyl group include unsaturated carboxylic acids such as (meth)acrylic acid, maleic acid, maleic anhydride, fumaric acid, tetrahydrophthalic anhydride, and itaconic acid, and from the viewpoint of excellent copolymerizability, (meth)acrylic acid is preferred.
Examples of the other monomers include (meth)acrylic monomers such as (meth)acrylic acid esters and hydroxylethyl (meth)acrylate, nitrile monomers such as (meth)acrylonitrile, amide monomers such as (meth)acrylamide, N-alkoxy-substituted amide monomers, N-methylol-substituted amide monomers, styrene monomers such as styrene, vinyl toluene, α-methylstyrene, and divinylbenzene, allyl monomers such as diallyl phthalate, allyl glycidyl ether, and triallyl isocyanurate, and monomers having a polymerizable double bond such as vinyl acetate and N-vinylpyrrolidone. As the other monomers, acrylic monomers and styrene monomers are preferred, and styrene monomers are more preferred.

The alkali-soluble resin is preferably a copolymer in which one or more types of monomers having an acid anhydride group or a carboxyl group are copolymerized with one or more types of other monomers.
The alkali-soluble resin is preferably a (meth)acrylic copolymer having an acid anhydride group or a carboxyl group, and a styrene-based monomer copolymer having an acid anhydride group or a carboxyl group, and more preferably a styrene-based monomer copolymer having an acid anhydride group or a carboxyl group.

As the other monomer, a monomer having a group that is easily saponified by an alkaline solution to increase hydrophilicity (hereinafter, also referred to as a "hydrophilicity improving group") may be used.
Examples of the monomer having a hydrophilicity improving group include lower alkyl esters of polymerizable unsaturated carboxyl compounds, and methyl acrylate is preferred from the viewpoint of excellent saponification rate with an alkaline solution.

Commercially available alkali-soluble resins include SMA17352P (styrene-maleic anhydride copolymer resin, manufactured by Kawahara Oil Chemical Co., Ltd., weight average molecular weight 7000, acid value: 270 mg KOH/g), Joncryl 682 (styrene-acrylic acid copolymer resin, manufactured by BASF, weight average molecular weight 1750, acid value: 238 mg KOH/g), etc.

The ratio of the total amount of units derived from monomers having an alkali-soluble group to the entire molecule of the alkali-soluble resin is preferably 0.1% by mass or more, more preferably 1% by mass or more, and even more preferably 5% by mass or more. The ratio of the total amount of units derived from monomers having an alkali-soluble group to the entire molecule of the alkali-soluble resin is preferably 70% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less.

From the viewpoint of solubility, the weight average molecular weight of the alkali-soluble resin is preferably 500 to 50,000, more preferably 1,000 to 10,000, and even more preferably 2,000 to 8,000.

The content of the alkali-soluble resin relative to the total mass of the printed layer is 1.0 to 15.0 mass%. From the viewpoint of removability of the printed layer with an alkaline liquid, the content of the alkali-soluble resin relative to the total mass of the printed layer is preferably 1.2 mass% or more, and more preferably 1.5 mass% or more. Furthermore, from the viewpoint of improving adhesion between the substrate and the printed layer in a long-term wet test, the content of the alkali-soluble resin relative to the total mass of the printed layer is preferably 14 mass% or less, more preferably 12 mass% or less, even more preferably 9.0 mass% or less, and particularly preferably 6.0 mass% or less.

- Pigments -
The pigment contained in the print layer may be any of organic pigments, inorganic pigments, etc. For example, examples of the pigment include white pigments such as titanium oxide and zinc oxide, black pigments such as carbon black, bismuth oxide, and chromium compounds, red pigments such as iron oxide and perylene, blue pigments such as aluminum cobalt oxide, blue or green pigments such as copper phthalocyanine, and yellow pigments such as bismuth vanadate.
Other examples include pearl-like mica, pearl-like silica, pearl-like glass, and pearl-like alumina, which are formed by coating titanium oxide or iron oxide on a flat substrate such as mica, silica, or alumina.
Furthermore, the pigment may be a near infrared absorbing pigment, a near infrared reflective pigment, or the like.
Examples of near-infrared absorbing pigments or near-infrared reflective pigments include boron compounds such as lanthanum hexaboride, which is a green pigment; tungsten compounds such as cesium tungstate, which is a blue pigment; indium tin oxide, which is a light blue pigment; antimony tin oxide, which is a blue pigment; and so-called pearl pigments that utilize the interference color of light.
The pigments may be used alone or in combination of two or more kinds.

In order to adjust the visible light reflectance and the solar radiation reflectance, an aluminum-based pigment or a stainless steel-based pigment may be used.
Aluminum pigments are most commonly used as inks for printing on the surface of fluororesin films, including, for example, aluminum particles such as aluminum flakes, and aluminum particles whose surfaces are coated with an organic or inorganic material (surface-treated aluminum particles).
Examples of the organic matter in the surface-treated aluminum particles include resins, fatty acids, silane coupling agents, etc., and examples of the inorganic matter include inorganic oxides such as silica, metals other than aluminum, etc. Among these, aluminum composite particles coated with (meth)acrylic resin or silica are particularly preferred from the viewpoint of preventing the visible light reflectance and solar reflectance of the laminate of the present disclosure from decreasing over a long period of time.

The total amount of the (meth)acrylic resin and silica coating in the aluminum composite particles is more preferably 3 to 35 parts by mass, more preferably 3 to 33 parts by mass, and particularly preferably 4 to 30 parts by mass, relative to 100 parts by mass of the aluminum particles. When the total amount of the (meth)acrylic resin and silica coating is equal to or greater than the lower limit of the range, the aluminum particles are sufficiently protected by the (meth)acrylic resin or silica, so that the solar reflectance of the laminate of the present disclosure is unlikely to decrease over a long period of time. When the total amount of the (meth)acrylic resin and silica coating is equal to or less than the upper limit of the range, the aluminum particles tend to be dissolved due to deterioration of the (meth)acrylic resin when the laminate of the present disclosure is used for a long period of time, and cracks are generated inside the silica, and the aluminum particles tend to be dissolved by the moisture that has penetrated. As a result, the solar reflectance of the laminate of the present disclosure is unlikely to decrease over a long period of time.
In another embodiment, the total amount of the (meth)acrylic resin and silica coated on the aluminum composite particles is preferably 30 to 45 parts by mass, more preferably 32 to 40 parts by mass, and even more preferably 34 to 38 parts by mass, relative to 100 parts by mass of the aluminum particles. When the total amount of the (meth)acrylic resin and silica coated is equal to or greater than the lower limit of the range, the aluminum particles are sufficiently protected by the (meth)acrylic resin or silica, so that the solar reflectance of the laminate of the present disclosure is unlikely to decrease over a long period of time. When the total amount of the (meth)acrylic resin and silica coated is equal to or less than the upper limit of the range, dissolution of aluminum by halogen ions or hydrogen halide generated from the base material, alkali-soluble resin, and other resins described below, or dissolution of aluminum by water is unlikely to occur, so that the solar reflectance of the laminate of the present disclosure is unlikely to decrease over a long period of time.

It is preferable that the aluminum composite particles do not dissolve in alkaline solutions. If aluminum composite particles dissolve in an alkaline aqueous solution, hydrogen gas may be generated.

The average major axis of the aluminum composite particles is preferably 6 to 25 μm, and more preferably 8 to 15 μm.
The average major axis length of the aluminum composite particles is the arithmetic average value obtained by measuring 20 particles using a scanning electron microscope (SEM).
Commercially available products containing aluminum composite particles include EMR-D5660, BP-280PA, BPZ-6370, WZA-7670, BPA-6390, EMR-B5680, EMR-D6390, and EMR-D4690 (all trade names, manufactured by Toyo Aluminum K.K.).

When the printing layer contains aluminum composite particles, from the viewpoint of the balance of solar reflectance, viscosity of the resin composition, adhesion, etc., the content of the aluminum composite particles is preferably 10 to 60 mass %, more preferably 15 to 50 mass %, and even more preferably 20 to 40 mass %, based on the total mass of the printing layer.

The content of the pigment is preferably from 0.1 to 60% by mass, and more preferably from 5 to 55% by mass, based on the total mass of the printed layer.
The content of the white pigment is preferably 20 to 60% by mass, more preferably 30 to 55% by mass, and the content of the black pigment is preferably 0.1 to 10% by mass, more preferably 1 to 5% by mass.

-Other resins-
The printing layer may contain a resin other than the alkali-soluble resin. The other resin may be used alone or in combination of two or more kinds.
Examples of the other resins include fluororesins, (meth)acrylic resins, polyester resins, vinyl resins, styrene resins, cellulose resins, carbonate resins, amide resins, polyolefin resins such as propylene resins, vinyl alcohol resins, imide resins, phenol resins, and urethane resins.
Among these, the other resin preferably contains at least one selected from the group consisting of fluororesin and (meth)acrylic resin from the viewpoint of excellent adhesion to the substrate. When the printed layer contains at least one of fluororesin and (meth)acrylic resin, the laminate of the present disclosure has excellent weather resistance, and the printed layer is prevented from hardening even after long-term use, and the deterioration of the conformability to the substrate is suppressed, so that adhesion is maintained. In particular, when the printed layer contains a fluororesin, it is preferable because it has excellent adhesion, even more excellent weather resistance, and also excellent contamination resistance.

[Fluororesin]
As the fluororesin as the other resin, known fluororesins can be applied, and among them, a copolymer having a fluoroolefin unit and a monomer unit having a hydroxyl group (hereinafter also referred to as a "specific fluororesin") is preferable. Since the specific fluororesin has a monomer unit having a hydroxyl group in addition to the fluoroolefin unit, it has excellent properties inherent to the fluororesin such as weather resistance and contamination resistance, and also has excellent adhesion to the substrate. The specific fluororesin may be a copolymer with other monomers.
The specific fluororesin may be used alone or in combination of two or more kinds.

The fluoroolefin in the fluoroolefin unit is preferably a fluoroolefin having 10 or less carbon atoms. Specific examples include vinyl fluoride, vinylidene fluoride, trifluoroethylene, chlorotrifluoroethylene (hereinafter also referred to as "CTFE"), tetrafluoroethylene (hereinafter also referred to as "TFE"), hexafluoropropylene, perfluorobutene-1, perfluorohexene-1, perfluorononene-1, (perfluoroalkyl)ethylene, etc., with (perfluoroalkyl)ethylene being preferred.

The (perfluoroalkyl)ethylene is a fluoroolefin represented by CH ₂ ═CH—R ^f (wherein R ^f represents a perfluoroalkyl group). Specific examples include (perfluoromethyl)ethylene and (perfluorobutyl)ethylene.
The (perfluoroalkyl)ethylene is preferably a (perfluoroalkyl)ethylene having 3 to 8 carbon atoms.
As the fluoroolefin other than (perfluoroalkyl)ethylene, a fluoroolefin having 2 or 3 carbon atoms (excluding CH ₂ ═CH—R ^f ) is preferred.

The monomer unit having a hydroxyl group may be a monomer unit having a fluorine atom or a monomer unit not having a fluorine atom, and is preferably a monomer unit not having a fluorine atom. Examples of the monomer unit having a hydroxyl group include units derived from allyl alcohol, hydroxyalkyl vinyl ether, hydroxyalkyl allyl ether, hydroxyalkyl (meth)acrylate, vinyl hydroxyalkyl carboxylate, allyl hydroxyalkyl carboxylate, etc. The hydroxyalkyl group of the monomer unit having a hydroxyalkyl group may be a hydroxycycloalkyl group, a hydroxyalkyl-substituted cycloalkyl group, etc. The number of carbon atoms in the hydroxyalkyl group is preferably 10 or less, more preferably 6 or less.

Examples of hydroxyalkyl vinyl ethers include 2-hydroxyethyl vinyl ether, 3-hydroxypropyl vinyl ether, 4-hydroxybutyl vinyl ether, and 4-hydroxycyclohexyl vinyl ether.
Examples of hydroxyalkyl allyl ethers include 2-hydroxyethyl allyl ether, 3-hydroxypropyl allyl ether, 4-hydroxybutyl allyl ether, and 4-hydroxycyclohexyl allyl ether.
Examples of the hydroxyalkyl (meth)acrylate include 2-hydroxyethyl (meth)acrylate.
Examples of the vinyl hydroxyalkyl carboxylate include vinyl hydroxyacetate, vinyl hydroxyisobutyrate, vinyl hydroxypropionate, vinyl hydroxybutyrate, vinyl hydroxyvalerate, and vinyl hydroxycyclohexanecarboxylate.
Examples of the allyl hydroxyalkyl carboxylate include allyl hydroxyacetate, allyl hydroxypropionate, allyl hydroxybutyrate, allyl hydroxyisobutyrate, and allyl hydroxycyclohexanecarboxylate.

Examples of monomer units other than fluoroolefin units and monomer units having a hydroxyl group include units derived from fluorine-containing monomers other than fluoroolefins, and units derived from monomers not having fluorine atoms (both excluding monomer units having a hydroxyl group).
Examples of fluorine-containing monomers other than fluoroolefins include perfluoro(alkyl vinyl ethers) and perfluoro unsaturated cyclic ethers.
The perfluoro(alkyl vinyl ether) is preferably a perfluoro(alkyl vinyl ether) having 10 or less carbon atoms, more preferably a perfluoro(alkyl vinyl ether) having 6 or less carbon atoms. Specific examples include perfluoro(methyl vinyl ether), perfluoro(ethyl vinyl ether), perfluoro(propyl vinyl ether), and perfluoro(heptyl vinyl ether).

Examples of the monomer having no fluorine atom include olefin, vinyl ether, allyl ether, vinyl carboxylate, allyl carboxylate, unsaturated carboxylate, etc. The number of carbon atoms of the vinyl ether, allyl ether, vinyl carboxylate, allyl carboxylate, and unsaturated carboxylate is preferably 16 or less, more preferably 12 or less, each independently.
The olefin is preferably an olefin having 2 to 4 carbon atoms, such as ethylene, propylene, and isobutylene.
Examples of vinyl ethers include cycloalkyl vinyl ethers (cyclohexyl vinyl ether, etc.), alkyl vinyl ethers (nonyl vinyl ether, 2-ethylhexyl vinyl ether, hexyl vinyl ether, ethyl vinyl ether, n-butyl vinyl ether, tert-butyl vinyl ether, etc.).
The allyl ether includes alkyl allyl ethers (ethyl allyl ether, hexyl allyl ether, etc.).
Examples of vinyl carboxylates include vinyl esters of carboxylic acids (acetic acid, butyric acid, pivalic acid, benzoic acid, propionic acid, etc.). In addition, Veova 9 (registered trademark) and Veova 10 (registered trademark) manufactured by Oxalis Chemicals Co., Ltd. may be used as vinyl esters of carboxylic acids having a branched alkyl group.
Examples of allyl carboxylates include allyl esters of carboxylic acids (acetic acid, butyric acid, pivalic acid, benzoic acid, propionic acid, etc.).
Examples of the unsaturated ester include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-amyl (meth)acrylate, isoamyl (meth)acrylate, n-hexyl (meth)acrylate, isohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and lauryl (meth)acrylate.

The specific fluororesin may further have monomer units having crosslinkable groups other than hydroxyl groups, such as carboxy groups, amide groups, and epoxy groups.

As a combination of a fluoroolefin unit and a monomer unit having a hydroxyl group in the specific fluororesin, a combination of at least one selected from the group consisting of tetrafluoroethylene and chlorotrifluoroethylene and a hydroxyalkyl vinyl ether is particularly preferred.

The proportion of fluoroolefin units in the specific fluororesin is preferably 30 to 70 mol %, and more preferably 40 to 60 mol %, of the total units of the specific fluororesin. If the proportion of fluoroolefin units is equal to or greater than the lower limit of the above range, a printed layer with excellent weather resistance, stain resistance, etc. tends to be obtained. If the proportion of fluoroolefin units is equal to or less than the upper limit of the above range, the adhesion between the substrate and the printed layer tends to be even better.

The proportion of monomer units having a hydroxyl group in the specific fluororesin is preferably 0.5 to 20 mol %, and more preferably 1 to 15 mol %, of the total units of the specific fluororesin. When the proportion of monomer units having a hydroxyl group is equal to or greater than the lower limit of the above range, the adhesion between the printed layer and the substrate tends to be even better. When the proportion of monomer units having a hydroxyl group is equal to or less than the upper limit of the above range, the flexibility of the printed layer tends to be excellent.

The proportion of monomer units in fluororesin can be confirmed using a nuclear magnetic resonance (NMR) spectrometer.

In one embodiment, the specific fluororesin is preferably a copolymer having a fluoroolefin unit, a monomer unit having a hydroxyl group, and a non-fluorine-based monomer unit not having a hydroxyl group. Hereinafter, such a copolymer is also referred to as "copolymer (A)."

As a combination of monomers constituting copolymer (A), the following combinations (1) to (3) are preferred, with combinations (2) and (3) being more preferred, in terms of the fact that the solar reflectance of the printed layer is unlikely to decrease over the long term, that the printed layer has excellent adhesion to the substrate, and that the printed layer has excellent flexibility.

Combination (1)
Fluoroolefin: tetrafluoroethylene or chlorotrifluoroethylene; Monomer having a hydroxyl group: hydroxyalkyl vinyl ether; Non-fluorine-based monomer not having a hydroxyl group: at least one selected from the group consisting of cycloalkyl vinyl ether, alkyl vinyl ether, and vinyl carboxylate.

Combination (2)
・Fluoroolefin: Tetrafluoroethylene ・Monomer with hydroxyl group: Hydroxyalkyl vinyl ether
Non-fluorinated monomer not having a hydroxyl group: at least one selected from the group consisting of tert-butyl vinyl ether and vinyl carboxylate

Combination (3)
・Fluoroolefin: Chlorotrifluoroethylene
- Monomers with hydroxyl groups: Hydroxyalkyl vinyl ether
Non-fluorinated monomer not having a hydroxyl group: at least one selected from the group consisting of tert-butyl vinyl ether and vinyl carboxylate

The proportion of fluoroolefin units in copolymer (A) is preferably 30 to 70 mol %, and more preferably 40 to 60 mol %, of the total units (100 mol %) of copolymer (A). When the proportion of fluoroolefin units is equal to or greater than the lower limit of the above range, a printed layer with excellent weather resistance, stain resistance, etc. tends to be obtained. When the proportion of fluoroolefin units is equal to or less than the upper limit of the above range, the adhesion between the substrate and the printed layer tends to be even better.

The proportion of monomer units having a hydroxyl group in copolymer (A) is preferably 0.5 to 20 mol %, and more preferably 1 to 15 mol %, of the total units of copolymer (A). When the proportion of monomer units having a hydroxyl group is equal to or greater than the lower limit of the above range, the adhesion between the printed layer and the substrate tends to be even better. When the proportion of monomer units having a hydroxyl group is equal to or less than the upper limit of the above range, the flexibility of the printed layer tends to be excellent.

The proportion of non-fluorine-based monomer units not having hydroxyl groups in copolymer (A) is preferably 20 to 60 mol %, more preferably 30 to 50 mol %, of the total units of copolymer (A). When the proportion of the monomer units is equal to or greater than the lower limit of the above range, the flexibility of the printed layer tends to be excellent. When the proportion of the monomer units is equal to or less than the upper limit of the above range, the adhesion between the printed layer and the substrate tends to be even better.

The copolymer (A) is preferably an alternating copolymer of fluoroolefin units, monomer units having a hydroxyl group, and non-fluorine-based monomer units not having a hydroxyl group. In such a case, the printed layer tends to have excellent weather resistance.

Commercially available copolymers (A) include the Lumiflon (registered trademark) series (LF200, LF200MEK, LF100, LF710, LF600, etc.) (AGC Inc.), the Zeffle (registered trademark) GK series (GK-500, GK-510, GK-550, GK-570, GK-580, etc.) (Daikin Industries, Ltd.), and the Fluonate (registered trademark) series. Examples include the ETFE series (K-700, K-702, K-703, K-704, K-705, K-707, etc.) (manufactured by DIC Corporation), and the ETERFLON series (4101, 41011, 4102, 41021, 4261A, 4262A, 42631, 4102A, 41041, 41111, 4261A, etc.) (manufactured by Eternal Chemical Co., Ltd.).

From the viewpoint of obtaining good adhesion, the hydroxyl value of the specific fluororesin is preferably 10 to 150 mgKOH/g, more preferably 15 to 120 mgKOH/g, even more preferably 20 to 100 mgKOH/g, and particularly preferably 20 to 50 mgKOH/g. The hydroxyl value of the fluororesin can be measured by Method A of ISO 14900:2001.

If the printing layer contains a fluororesin as another resin, the content of the fluororesin is preferably 40 to 99 mass% of the total mass of the printing layer, and more preferably 45 to 98 mass%.

[(Meth)acrylic resin]
As the (meth)acrylic resin as the other resin, a known (meth)acrylic resin can be used. When a (meth)acrylic resin is used as the other resin contained in the printed layer, the printed layer has excellent adhesion to the substrate.

The (meth)acrylic resin preferably contains units derived from acrylic monomers such as alkyl (meth)acrylates, hydroxyl group-containing alkyl (meth)acrylates, carboxyl group-containing acrylic monomers, amide bond group-containing acrylic monomers, amino group-containing acrylic monomers, alkylene oxide group-containing acrylic monomers, aromatic ring-containing acrylic monomers, epoxy group-containing acrylic monomers, and acrylic polyols. The units derived from acrylic monomers may be of one type alone or two or more types in combination.

Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, cyclopentyl (meth)acrylate, methylcyclohexyl (meth)acrylate, bornyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, decyl (meth)acrylate, dodecyl (meth)acrylate, tetradecyl (meth)acrylate, hexadecyl (meth)acrylate, and octadecyl (meth)acrylate. Among these, methyl (meth)acrylate is preferred because it is easy to obtain good adhesion to the substrate.

Hydroxyl group-containing alkyl (meth)acrylates include hydroxyalkyl (meth)acrylate esters such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 8-hydroxyoctyl (meth)acrylate; glycol mono(meth)acrylates such as polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, and 1,4-cyclohexanedimethanol mono(meth)acrylate; caprolactone-modified (meth)acrylates; and hydroxyethylacrylamide. Of these, 2-hydroxyethyl (meth)acrylate and 4-hydroxybutyl (meth)acrylate are preferred.

Carboxyl group-containing acrylic monomers include (meth)acrylic acid, monohydroxyethyl phthalate acrylate, p-carboxybenzyl acrylate, ethylene oxide-modified (number of moles added: 2 to 18) phthalate acrylate, monohydroxypropyl phthalate acrylate, monohydroxyethyl succinate acrylate, β-carboxyethyl acrylate, and 2-(4-benzoyl-3-hydroxyphenoxy)ethyl acrylate.

Examples of acrylic monomers containing amide bond groups include N-isopropyl(meth)acrylamide and N,N-diethylacrylamide.

Examples of amino group-containing acrylic monomers include monomethylaminoethyl (meth)acrylate, monoethylaminoethyl (meth)acrylate, monomethylaminopropyl (meth)acrylate, and monoethylaminopropyl (meth)acrylate.

For example, examples of alkylene oxide group-containing acrylic monomers include 2-methoxyethyl acrylate, 2-ethoxyethyl acrylate, 2-phenoxyethyl acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, ethoxypolypropylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, and phenoxypolypropylene glycol (meth)acrylate.

Examples of aromatic ring-containing acrylic monomers include phenyl (meth)acrylate, benzyl (meth)acrylate, phenoxymethyl (meth)acrylate, phenoxyethyl (meth)acrylate, and 2-hydroxy-3-phenoxypropyl (meth)acrylate.

Examples of epoxy group-containing acrylic monomers include glycidyl (meth)acrylate, α-methylglycidyl acrylate, α-methylglycidyl methacrylate, 3,4-epoxycyclohexylmethyl acrylate, and 3,4-epoxycyclohexylmethyl methacrylate.

The (meth)acrylic resin may have an acid value, and in this case, the acid value is preferably 20 mgKOH/g or less, more preferably 10 mgKOH/g or less. By having an acid value of 20 mgKOH/g or less, the durability of the printed layer and the laminate can be further improved.
The acid value can be imparted to the (meth)acrylic resin by copolymerization of an acrylic monomer having an acid value with another acrylic monomer. Examples of the acrylic monomer having an acid value include (meth)acrylic acid, maleic anhydride, 2-(meth)acryloyloxyethyl-succinic acid, 2-(meth)acryloyloxyethyl-hexahydrophthalic acid, 2-(meth)acryloyloxyethyl-phthalic acid, and 2-(meth)acryloyloxyethyl acid phosphate.

The glass transition temperature (Tg) of the (meth)acrylic resin is preferably 20 to 100°C, more preferably 30 to 90°C, and even more preferably 30 to 80°C. A glass transition temperature of 20°C or higher improves blocking properties, and a glass transition temperature of 100°C or lower maintains good adhesion.

The weight-average molecular weight (Mw) of the (meth)acrylic resin is preferably 3000 to 300,000. By making the weight-average molecular weight 3000 or more, it is possible to suppress the settling of the pigment and further to achieve both moldability and surface hardness. By making the weight-average molecular weight 300,000 or less, it is possible to obtain a printing layer with good chemical resistance.

The (meth)acrylic resin may be a synthetic product or a commercially available product. For example, an example of an acrylic polyol is the 6000 series manufactured by Taisei Fine Chemical Co., Ltd. Examples of homopolymers of acrylate monomers such as alkyl acrylates and alkyl methacrylates, and copolymers with other monomers include Dianale solution type and Dianale beads type manufactured by Mitsubishi Chemical Corporation.

If the printing layer contains a (meth)acrylic resin as another resin, the content of the (meth)acrylic resin is preferably 40 to 99% by mass, and more preferably 45 to 98% by mass, based on the total mass of the printing layer.

-Other ingredients-
In addition to the above-mentioned components, the printed layer may contain additives such as antiblocking agents, lubricants, curing agents, UV absorbers, antisettling agents, plasticizers, dispersion stabilizers, fillers, antioxidants, antistatic agents, matting agents (silica, alumina, etc.), tack improvers (polyolefins, etc.), adhesion improvers (silane coupling agents, etc.), etc. Furthermore, the printed layer may contain a solvent (solvent, water, etc.), a curing agent, etc., contained in the ink used to form the printed layer.

[Anti-blocking agent]
When the printed layer contains an anti-blocking agent, the problem of the printed surfaces coming into contact with each other and adhering to each other when the laminate of the present disclosure is spread out is effectively avoided. Note that if the blocking temperature of the printed layer itself exceeds 45° C., it may not be necessary to add an anti-blocking agent.

Examples of the anti-blocking agent include silicon compounds, chlorinated polyethylene, (meth)acrylic resin beads, esterified cellulose resins, etc. Among these, esterified cellulose resins are preferred.
Examples of esterified cellulose resins include cellulose acetate resin, cellulose acetate butyrate (CAB) resin, and cellulose acetate propionate (CAP) resin. In general, CAP is obtained by triesterifying cellulose with acetic acid and propionic acid, followed by hydrolysis. CAB is obtained by triesterifying cellulose with acetic acid and butyric acid, followed by hydrolysis.
The esterified cellulose resin is preferably at least one selected from the group consisting of CAB and CAP. The esterified cellulose resin may be used alone or in combination of two or more.
When the printed layer contains an esterified cellulose resin, the adhesion between the printed layer and the functional layer described below tends to be improved when the functional layer is provided. One of the reasons for this is thought to be that the esterified cellulose resin present on the surface of the printed layer is partially dissolved or compatible with the components in the functional layer.

If the printing layer contains an anti-blocking agent, the content of the anti-blocking agent is preferably 0.5 to 20 mass %, and more preferably 1 to 10 mass %, relative to the total mass of the printing layer. If the content is equal to or greater than the lower limit, the anti-blocking effect is achieved, and if the content is equal to or less than the upper limit, initial poor adhesion to the substrate tends to be suppressed.

[Lubricant]
Examples of the lubricant include various waxes such as polyolefin waxes such as polyethylene wax, fatty acid amides, fatty acid esters, paraffin wax, polytetrafluoroethylene (PTFE) wax, and carnauba wax.
When the printing layer contains a lubricant, the content of the lubricant can be appropriately adjusted and is, for example, preferably 0.05 to 3 mass %, and more preferably 0.2 to 1 mass %, relative to the total mass of the printing layer.

[UV absorber]
Examples of the UV absorbent include inorganic UV absorbents and organic UV absorbents.
Examples of the organic UV absorbent include triazine-based UV absorbents and benzophenone-based UV absorbents, with triazine-based UV absorbents being preferred. Among these, hydroxyphenyltriazine-based UV absorbers such as 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4-phenylphenyl)-1,3,5-triazine (manufactured by BASF Japan Ltd., trade name: TINUVIN 479), 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl)-1,3,5-triazine (manufactured by BASF Japan Ltd., trade name: TINUVIN 460), and 2-[4-[(2-hydroxy-3-(2'-ethyl)hexyloxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine (manufactured by BASF Japan Ltd., trade name: TINUVIN 405) are preferred.
When the printed layer contains a UV absorber, the content of the UV absorber can be appropriately adjusted. For example, the total content of the UV absorber and the pigment is preferably 1 to 15% by mass, more preferably 2 to 10% by mass, based on the total mass of the printed layer.

[Curing agent]
When the printed layer contains a hardener, the water resistance, solvent resistance, and blocking resistance tend to be improved, whereas when the printed layer does not contain a hardener, the printed layer is easily removed with an alkaline solution.
Therefore, it is preferable that the printing layer does not contain a curing agent or contains only a small amount of a curing agent.
The curing agent can be appropriately selected from known curing agents for coating materials. Specific examples include isocyanate-based curing agents, blocked isocyanate-based curing agents, aminoplast-based curing agents, polycarboxylic acid-based curing agents, and polyamine-based curing agents. The curing agent is preferably selected in consideration of the type of curing reactive site of the fluororesin, curing characteristics, and the like. As the curing agent, isocyanate-based curing agents, blocked isocyanate-based curing agents, or aminoplast-based curing agents are preferred. The curing agent may be used alone or in combination of two or more.

[solvent]
The solvent may be any solvent capable of dissolving or dispersing the resin, pigment, etc., and may be appropriately selected depending on the coating method, taking into consideration the repellency of the paint on the substrate, transfer rate, drying properties, storage stability, etc.
Examples of the solvent include aqueous solvents and organic solvents, and one type may be used alone or two or more types may be used in combination.
Examples of the organic solvent include toluene, xylene, ethylbenzene, methyl ethyl ketone, ethyl acetate, and isopropyl alcohol.
In gravure printing, in order to reduce printing defects such as uneven application and bleeding, a solvent that gives the ink a No. 3 Zahn cup viscosity of 15 to 30 seconds is preferred.
When the printed layer is formed by an inkjet method, the ink may further contain a high boiling point solvent to prevent the ink ejection port from drying out.

(Laminate structure, physical properties, etc.)
In the laminate of the present disclosure, the printed layer may be provided on the entire surface of one side of the substrate, or may be provided on a portion of the surface. Also, the printed layer may be provided on one side of the substrate, or on both sides of the substrate.

The ratio of the area of the printed layer to the total area of one side of the substrate may be appropriately selected depending on the purpose, etc., and may be, for example, 10 to 100%, or may be less than 95%, less than 90%, or less than 80%. In addition, the ratio of the area of the printed layer to the total area of one side of the substrate may be 80% or more, 90% or more, or 95% or more.

The printing layer may be one layer or two or more layers.
The thickness of the printed layer (the total thickness when there are two or more layers) is preferably 0.5 to 10 μm, more preferably 1 to 6 μm. When the thickness of the printed layer is equal to or less than the upper limit of the above range, the printed layer can follow deformation of the substrate such as expansion, contraction, bending, etc., and the printed layer tends not to peel off from the substrate. When the thickness of the printed layer is equal to or more than the lower limit of the above range, the printed layer is not too thin and has an excellent effect of reducing solar radiation transmittance, etc.

The laminate may further include layers other than the substrate and the printed layer.
For example, the laminate may further have a functional layer on the printed layer. The functional layer can be formed by coating, transfer using a transfer film, sputtering, etc. The functional layer may be one layer or two or more layers.
In the present disclosure, a functional layer refers to a layer that imparts a desired function to the laminate. The desired function imparted to the laminate includes design, optical properties (ultraviolet ray absorption, ultraviolet ray reflectivity, near-infrared ray absorption, near-infrared ray reflectivity, etc.), durability, etc.
Examples of components of the functional layer include the above-mentioned pigments, UV absorbents, near-infrared absorbing pigments, near-infrared reflective pigments, and curing agents.
The laminate may also have an adhesive layer between the substrate and the printed layer, or between the printed layer and any other layer. Examples of the adhesive layer include a layer formed by applying a silane coupling agent.

The solar reflectance of the laminate of the present disclosure is preferably 20% or more, and more preferably 40% or more.
The solar reflectance of the laminate of the present disclosure is preferably 90% or less, and more preferably 80% or less.

When the laminate of the present disclosure is used as a membrane material for roofs, walls, etc., the film is constantly deforming and returning to its original shape due to deformation caused by snow load, vibration caused by wind, stamping caused by raindrops, etc. It is desirable that the printing layer provided on such a laminate has high adhesion so that it does not peel off even if the substrate is deformed.
In addition, it is expected that the printed layer will be wet for a long time due to condensation or rain blown in by wind, etc. Therefore, it is desirable for the printed layer to have excellent durability when exposed to water (retention of adhesion, maintenance of solar reflectance, etc.).
From this viewpoint, the solar reflectance maintenance rate of the laminate after the 80°C steam test described in the Examples is preferably 85% or more, more preferably 90% or more, and even more preferably 92% or more. The upper limit of the solar reflectance maintenance rate after the 80°C steam test is 100%.
Furthermore, it is preferable that the material has high resistance to ultraviolet rays outdoors.
From this viewpoint, the solar reflectance retention rate of the laminate after the accelerated weather resistance test described in the Examples is preferably 85% or more, more preferably 90% or more, and even more preferably 91% or more. The upper limit of the solar reflectance retention rate after the accelerated weather resistance test is 100%.

<Method of manufacturing laminate>
The method for producing the laminate of the present disclosure is not particularly limited. For example, the laminate may be obtained by applying an ink containing an alkali-soluble resin and a pigment to at least a part of a film containing a fluororesin. The ink may be in any form such as a solution, a dispersion, or a varnish.
The printed layer may be a coating layer obtained by applying ink to a substrate, or may be an ink layer which has been dried as necessary to remove at least a portion of the solvent, or may be a cured layer which has been cured by heating or the like.

The ink components preferably contain other resins in addition to the alkali-soluble resin and pigment, and may further contain other components such as a solvent.
When the ink contains a solvent, the content of the solvent is preferably from 30 to 90% by mass, and more preferably from 40 to 80% by mass, based on the total mass of the ink.

The method for applying the ink to the substrate is not particularly limited, and examples thereof include the following methods.
- A method of applying ink onto a substrate by a known application method such as gravure printing, screen printing, pad printing, inkjet, brush coating, spray coating, die coating, etc. - A method of using a transfer film having a printed layer and transferring the printed layer on the transfer film to the substrate by a heated roll or the like. As a method of applying ink to a substrate, from the viewpoints of accuracy of alignment, productivity, etc., gravure printing, screen printing, pad printing and inkjet methods are preferred, and gravure printing is more preferred.

In the coating method, methods for removing the solvent after applying the ink to the substrate include heat drying, reduced pressure drying, and heat and reduced pressure drying. In the case of heat drying or heat and reduced pressure drying, the heating temperature is preferably 30 to 150°C, and more preferably 60 to 120°C. Drying may be performed once or multiple times.

If the ink is a resin composition containing a curing agent, the ink may be cured by heating to, for example, 40 to 80°C to form a printed layer.

　The surface of the printing layer may be subjected to a surface treatment to improve adhesion, taking into consideration the further formation of a functional layer thereon, which will be described later. Examples of surface treatments include the same treatments that can be applied to the substrate.

<Manufacturing method of recycled film>
In one embodiment of the method for producing a recycled film of the present disclosure, the laminate of the present disclosure is immersed in an alkaline solution to remove the printed layer, thereby obtaining a recycled film containing a fluororesin. Since the printed layer of the laminate of the present disclosure can be easily removed by the alkaline solution, the film containing a fluororesin can be easily removed from the laminate of the present disclosure. This embodiment of the production method is particularly useful when reusing the substrate in the form of a film contained in the laminate.

In another embodiment of the manufacturing method for the recycled film of the present disclosure, the laminate of the present disclosure is immersed in an alkaline solution to remove the printed layer, to obtain a film containing a fluororesin, and the obtained film containing a fluororesin is melted and molded to obtain a recycled film containing a fluororesin. The film may be melted and formed into pellets, and then molded. In this embodiment of the manufacturing method, it is possible to process the film into a shape different from the shape of the film contained in the laminate and reuse it.

The pH of the alkaline liquid used to remove the printed layer from the laminate is preferably from 10 to 14, and more preferably from 10 to 13. Specifically, examples of the alkaline liquid include an aqueous solution of sodium hydroxide and an aqueous solution of potassium hydroxide.
The alkaline solution may be heated before use, for example to a temperature of 70 to 90°C.

The laminate may be cut and then impregnated with an alkaline solution. Alternatively, the printed layer may be removed from the laminate, and then the fluororesin-containing film may be cut. The cut size and shape are not particularly limited.
After removing the printed layer from the laminate, the resulting film containing the fluororesin may be washed with water and dried.

The recycled film obtained by the manufacturing method disclosed herein is less susceptible to black defects and discoloration resulting from the printed layer. Furthermore, the resulting film containing fluororesin may be reused in the laminate disclosed herein or may be used for other purposes.

The decrease in visible light transmittance of recycled film depends on the thickness, but is preferably within 2%, and more preferably within 1%, compared to an unrecycled film of the same thickness that does not have a printed layer. The method for measuring visible light transmittance is as described in the Examples. In the Examples, the visible light transmittance of the 250 μm film before printing is 91%, so in this case the visible light transmittance of the recycled film is preferably 89% or more. A small decrease in visible light transmittance indicates that coloration is suppressed.

The change in stress when the recycled film is elongated by 10% varies slightly depending on the thickness of the film to be molded, but a change within ±2 MPa is preferable, and a change within ±1 MPa is even more preferable, compared to an unrecycled film of the same thickness that does not have a printed layer. In the example, the stress when the 250 μm film before printing is elongated by 10% is 21 MPa, so in this case the stress when the recycled film is elongated by 10% is preferably 19 MPa or more. Furthermore, 20 MPa or more is even more preferable.

The present disclosure will be explained in more detail using examples, but the present disclosure is not limited to the following examples as long as it does not exceed the gist of the disclosure. Examples 2 to 4, 6 to 9, and 11 to 13 are examples, and Examples 1, 5, and 10 are comparative examples.

<Ink Preparation>
The inks of Examples 1 to 13 were prepared by incorporating the components shown in Table 1 below in the amounts (parts by mass) shown in Table 1. The inks of Examples 1 to 13 had a viscosity of 24 to 25 seconds using a No. 3 Zahn cup.
The components are as follows:

[Aluminum paste 1]
EMR-D5660 (product name, manufactured by Toyo Aluminum K.K.) was used as the aluminum paste 1. This aluminum paste contains 49.5 mass% of aluminum composite particles 1 in which the surfaces of flat aluminum are coated with 25 mass% of silica relative to 100 mass% of aluminum, and contains 50.5 mass% of propylene glycol monomethyl ether as a solvent. The average major axis of these aluminum composite particles 1 is 9 μm.

[Aluminum paste 2]
BP-280PA (product name, manufactured by Toyo Aluminum K.K.) was used as the aluminum paste 2. This aluminum paste contains 50 mass% of aluminum composite particles 2 in which the surfaces of flat aluminum are coated with 12 mass% (meth)acrylic resin relative to 100 mass% of aluminum, and 50 mass% of n-propyl acetate as a solvent. The average major axis of the aluminum composite particles 2 is 9 μm.

[Aluminum paste 3]
EMR-D6390 (product name, manufactured by Toyo Aluminum K.K.) was used as the aluminum paste 3. This aluminum paste contains 54.5 mass% of aluminum composite particles 3 in which the surfaces of flat aluminum are coated with 34.5 mass% of silica relative to 100 mass% of aluminum, and contains 45.5 mass% of propylene glycol monomethyl ether n-propyl acetate as a solvent. The average major axis of the aluminum composite particles 3 is 9 μm.

[Aluminum paste 4]
EMR-D4690 (product name, manufactured by Toyo Aluminum K.K.) was used as the aluminum paste 4. This aluminum paste contains 50 mass% of aluminum composite particles 4 in which the surfaces of flat aluminum are coated with 37 mass% of silica relative to 100 mass% of aluminum, and 50 mass% of propylene glycol monomethyl ether as a solvent. The average major axis of the aluminum composite particles 4 is 9 μm.

[Fluororesin varnish]
LF200MEK (manufactured by AGC Inc., solid content: 60% by mass, solvent: methyl ethyl ketone, hydroxyl value: 31 mg (KOH)/g) was used as the fluororesin varnish. The resin of LF200MEK (specific fluororesin) is an alternating copolymer of fluoroethylene and vinyl ether, and contains units derived from hydroxyalkyl vinyl ether.

[(Meth)acrylic resin varnish]
As a (meth)acrylic resin, Dianale BR115 (manufactured by Mitsubishi Chemical Corporation, (meth)acrylic resin, Tg 48°C, acid value 0 mgKOH/g, weight average molecular weight 5000) was dissolved in ethyl acetate, and an ethyl acetate solution with a solid content of 40 mass% was used as a (meth)acrylic resin varnish.

[Anti-blocking agent liquid]
An esterified cellulose resin (product name: CAB-381-2, manufactured by Eastman Chemical Japan, glass transition point 133° C., number average molecular weight 40,000, hydroxyl group content 1.3% by mass) was used as the antiblocking agent. This resin was dissolved in methyl ethyl ketone (MEK) to prepare an antiblocking agent solution with a solid content concentration of 20% by mass.

[Alkali-soluble resin liquid 1]
A styrene-maleic anhydride copolymer resin (product name: SMA17352P, manufactured by Kawahara Oil Chemical Co., Ltd., weight average molecular weight 7000, acid value: 270 mg KOH/g, dissolves at least 0.1 g in 100 mL of 1.5 mass % aqueous sodium hydroxide solution at 85° C.) was used as the alkali-soluble resin 1. This was dissolved in MEK to prepare an alkali-soluble resin solution 1 with a solid content of 20 mass %.

[Alkali-soluble resin liquid 2]
A styrene-acrylic acid copolymer resin (product name: Joncryl 682: manufactured by BASF, weight average molecular weight 1750, acid value: 238 mg KOH/g, dissolves at least 0.1 g in 100 mL of 1.5 mass % aqueous sodium hydroxide solution at 85° C.) was used as the alkali-soluble resin 2. This was dissolved in ethyl acetate (EA) to prepare an alkali-soluble resin solution 2 with a solid content of 50 mass %.

[Curing agent]
The curing agent used was a polyisocyanate of hexamethylene diisocyanate (product name: Duranate A201H, manufactured by Asahi Kasei Corporation). The NCO content of this curing agent was 17.2% by mass.

[Dilution Solvent]
As a dilution solvent, a mixed solvent of MEK and toluene (MEK:toluene=50:50 (by mass)) was used.

<Production of Laminate>
The surface of a 250 μm ETFE film (manufactured by AGC Inc., product name: Fluon ETFE Film 250NJ, fluorine atom content of ETFE is 46 mass%, ETFE content is 100 mass%, stress for 10% elongation is 21 MPa, total light transmittance is 92.0%) was subjected to a corona discharge treatment in air at a treatment density of 150 W min / m ^2. The surface tension of the corona discharge treated surface was 0.054 N / m.
Subsequently, the prepared ink was printed by gravure printing on the corona-treated surface of the ETFE film that had been subjected to corona discharge treatment, and dried at 120°C for 1 minute. The design of the gravure printing plate was in the form of dots with a diameter of 16 mm, and the printing area ratio was 58%. The mass of the printing layer per unit area of the substrate ^was 1.4 g/m2 to 1.6 g/ ^m2 . The thickness of the printing layer was 2 μm.

<Evaluation>
As the initial physical properties of the obtained laminate, the solar reflectance was measured, the adhesion strength was evaluated by a peel test, and an alkali desorption test was performed.
In addition, the laminate was subjected to an accelerated weather resistance test, and then the solar reflectance retention rate was measured, and the adhesion strength was evaluated by a peel test, and an alkali desorption test was also performed.
Furthermore, after the laminate was subjected to a steam test at 80° C., the solar reflectance retention rate was measured and the adhesion strength was evaluated by a peel test.
A recycled film was produced from the resulting laminate, and the visible light transmittance and stress at 10% elongation of this recycled film were measured.
The respective measurement and evaluation methods are as follows. The results are shown in Table 2.

(Solar reflectance)
The solar reflectance was measured using a spectrophotometer (UV-3100PC, manufactured by Shimadzu Corporation) in accordance with JIS R3106:1998 ("Test method for transmittance, reflectance, emissivity, and solar heat gain coefficient of plate glass"). These optical properties were measured by irradiating light from the substrate side.

(Peel test)
In accordance with JIS K5600-5-6:1999, 10 x 10 lattice cuts of 1 mm squares were made on the printed layer formed on the substrate (total of 100 squares), and Cellophane Tape (registered trademark) (manufactured by Nichiban Co., Ltd.: product name CT18) was attached, and then the tape was peeled off. The number of peeled squares out of the 100 squares was counted, and the adhesion was evaluated according to the following criteria. A rating of A or B was deemed to be acceptable.
A (excellent): 0 or more but less than 2 squares peeled off.
B (good): 2 or more but less than 20 squares peeled off.
C (bad): 20 or more squares peeled off.

(Alkaline desorption test)
The laminate was cut to a size of 5 cm x 30 cm, immersed in a 1% by mass aqueous solution of sodium hydroxide (pH: 13.2) at 85°C, and stirred for 20 minutes, and the state of detachment of the printed layer was observed and evaluated according to the following criteria. The evaluation result of A was deemed to be acceptable.
A (good): The entire printed layer was detached.
B (poor): At least a part of the printed layer remained.

(Accelerated weather resistance test)
The laminate was exposed to ultraviolet light of 300 to 450 nm wavelength and 1500 mW/cm ² using an accelerated weathering tester (e.g., manufactured by Iwasaki Electric Co., Ltd., product name: Eye UV Tester SUV-W231). The laminate was exposed to ultraviolet light of 300 to 450 nm wavelength and 1500 mW/cm 2 intensity using a cycle (12 hours and 20 seconds per cycle) consisting of (i) 10 hours of ultraviolet light irradiation under conditions of a black panel (BP) temperature of 63°C and a relative humidity of 50% RH, (ii) 10 seconds of shower, (iii) 2 hours of dark condensation under conditions of a BP temperature of 30°C and a relative humidity of 100% RH, and (iv) 10 seconds of shower, while repeatedly exposed to ultraviolet light for 500 hours. The cumulative amount of ultraviolet light under these conditions was 2400 MJ/m ² , which is equivalent to about 10 years of outdoor exposure since the amount of ultraviolet light in Choshi City, Japan is about 250 MJ/m ² per year.

(80°C steam test)
A water tank with water temperature of 80°C was placed indoors at 23°C, and the top of the water tank was covered with the laminate. At this time, the printed layer of the laminate was placed on the inside (the water side of the water tank). In this state, exposure was performed for 5 days.

(Solar reflectance retention rate after accelerated weather resistance test)
The solar reflectance was measured before and after the accelerated weather resistance test, and the solar reflectance maintenance rate was calculated and evaluated according to the following criteria. The evaluation result of A was deemed to be pass.
A (Good): Solar reflectance maintenance rate is 85% or more B (Poor): Solar reflectance maintenance rate is less than 85%

(Solar reflectance retention rate after 80°C steam test)
The solar reflectance was measured before and after the 80° C. steam test, and the solar reflectance maintenance rate was calculated and evaluated according to the following criteria. The evaluation result of A was deemed to be acceptable.
A (Good): Solar reflectance maintenance rate is 85% or more B (Poor): Solar reflectance maintenance rate is less than 85%

(Production and evaluation of recycled film)
The laminate was cut to a size of 5 cm x 30 cm and immersed in a 1% by mass aqueous solution of sodium hydroxide at 85°C for 20 minutes to remove the printed layer. The resulting substrate was then taken out, washed with water and dried.

The obtained base material was fed into a 15 mmφ co-rotating twin screw extruder (manufactured by Technobel Co., Ltd.), the cylinder and head temperatures were set to 280° C., and pellets having a diameter of 2 mmφ and a length of 3 mm were obtained. The discharge rate at this time was 2 kg/hour.
The obtained pellets were used to extrude a recycled film having a thickness of 250 μm using a 30 mm short screw extruder equipped with a 150 mm wide T-die at the tip.

The visible light transmittance and stress at 10% elongation of the recycled film were measured.
The stress at 10% elongation was measured at a tensile speed of 200 mm/min in accordance with JIS K7127:1999 (Plastics-Test methods for tensile properties-Part 3: Test conditions for films and sheets). Type V test pieces with a gauge length of 25 mm were used for the stress at 10% elongation.

The virgin 250 μm thick ETFE film used as the raw material for the laminate has a visible light transmittance of 91% and a stress of 21 MPa at 10% elongation, so the recycled film was evaluated according to the following criteria.

- Visible light transmittance of recycled film -
A (good): 89% or more B (poor): less than 89%

- Stress of recycled film when stretched by 10% -
A (good): 19 MPa or more B (poor): less than 19 MPa

 

 

<Considerations>
[Example 1]
The initial solar reflectance was 58.6%. The peeling test result was judged to be pass, with not even one square peeling off. In the alkali desorption test, no desorption occurred after 20 minutes of immersion and stirring.
In addition, the solar reflectance after 500 hours of accelerated weather resistance testing was 58.0%, and the solar reflectance maintenance rate was 99%. The peeling test after the accelerated weather resistance testing was passed without any peeling. However, in the alkali desorption test after the accelerated weather resistance testing, the ink did not desorb.
In addition, the solar reflectance retention rate after the 80° C. steam exposure test was 92%, and the film passed the test without peeling off even one square. The film also passed the peeling test.
The visible light transmittance of the recycled film was 86%, and it was clearly colored brown. In addition, holes were found in the recycled film that were thought to be caused by gas generation. The stress of the recycled film at 10% elongation was 16.2 MPa, which did not meet the 19 MPa requirement and therefore failed the test.
Because the ink was not sufficiently removed by the alkaline solution, the recycled film had insufficient visible light transmittance and mechanical properties.

[Example 2]
The initial solar reflectance was 56.6%. The peeling test results were good, with not even one square peeling off. In the alkali desorption test, the printed layer was completely desorbed after 20 minutes of immersion and agitation.
The solar reflectance retention rate after 500 hours of accelerated weathering test was 99%. The peeling test after the accelerated weathering test was passed with not even one square peeling. In the alkali desorption test after the accelerated weathering test, the ink was completely desorbed.
In addition, the solar reflectance retention rate after the 80° C. steam exposure test was 92%, and the peeling test was also passed with not even one square peeling off.
The visible light transmittance of the recycled film was 90%, and no coloring was observed. The stress of the recycled film at 10% elongation was 20.8 MPa, which exceeded 19 MPa and therefore passed the test.
It was determined that the ink had been sufficiently removed by the alkaline hot water, and that the mechanical properties and visible light transmittance of the recycled film were comparable to those of the virgin ETFE film used as the raw material for the laminate.

[Examples 3 and 4]
Examples 3 and 4, in which the alkali-soluble resin contents were 3.4% by mass and 10.9% by mass, respectively, showed good results in the initial solar reflectance, after the accelerated weather resistance test, and after the 80°C steam test, the peel test, the alkali desorption test, etc.
It was also found that the recycled films of Examples 3 and 4 were less discolored and maintained their mechanical properties sufficiently.

[Example 5]
In the case of Example 5 in which the content of the alkali-soluble resin was 16.1% by mass, problems were observed in the solar reflectance maintenance rate after the accelerated weather resistance test, the reflectance maintenance rate after the 80° C. steam test, and the peel test.
It was found that the recycled film of Example 5 had little coloring and also maintained sufficient mechanical properties.

[Example 6]
The solar reflectance or solar reflectance retention rate, peel test, and detachment test showed good results initially, after the accelerated weather resistance test, and after the 80° C. steam test. In addition, the recycled film had little coloring and maintained sufficient mechanical properties.

[Examples 7 to 9]
Examples 7 to 9 show good results in solar reflectance, solar reflectance maintenance rate, peel test, and detachment test at the initial stage, after the accelerated weather resistance test, and after the 80° C. steam test. In addition, the recycled films were little discolored, and the mechanical properties were sufficiently maintained.
It was also found that the recycled films of Examples 7 to 9 were less discolored and maintained their mechanical properties sufficiently.

[Example 10]
In the case of Example 10 in which the content of the alkali-soluble resin was 18.3% by mass, problems were observed in the solar reflectance retention rate after the accelerated weather resistance test and the peel test, and in the solar reflectance retention rate after the 80° C. steam test and the peel test.
It was found that the recycled film of Example 10 had little coloring and also maintained sufficient mechanical properties.

[Example 11]
The solar reflectance, solar reflectance retention, peel test, and detachment test showed good results initially, after the accelerated weather resistance test, and after the 80° C. steam test. In addition, the recycled film had little coloring and maintained sufficient mechanical properties.

[Example 12]
The solar reflectance, solar reflectance retention, peel test, and detachment test showed good results initially, after the accelerated weather resistance test, and after the 80° C. steam test. In addition, the recycled film had little coloring and maintained sufficient mechanical properties.

[Example 13]
The solar reflectance, solar reflectance retention, peel test, and detachment test showed good results initially, after the accelerated weather resistance test, and after the 80° C. steam test. In addition, the recycled film had little coloring and maintained sufficient mechanical properties.

The laminate of the present disclosure has excellent weather resistance and can be suitably used outdoors.
The application of the laminate of the present disclosure is not particularly limited, but it is suitably used as a roofing material, a wall covering material, and a display material. Specifically, it is suitable for use as a membrane material (roofing material, exterior wall material, skylight, waterproof sheet, protective sheet, etc.) in membrane structure facilities (sports facilities (swimming pools, gymnasiums, tennis courts, soccer fields, athletic stadiums, etc.), warehouses, assembly halls, exhibition halls, horticultural facilities (horticultural houses, agricultural houses, etc.), arcades, etc.); membrane material for screens; soundproof walls; windbreak fences; overtopping fences; highway side walls; garage canopies; membrane material for shopping malls; walkway walls; glass shatterproof films; heat-resistant sheets; water-resistant sheets; tent materials for tent warehouses; membrane materials for adjusting solar radiation; light Examples of such materials include partial roofing materials for removal, window materials replacing glass, fireproof partition membrane materials, curtains, membrane materials for reinforcing exterior walls, waterproof membranes, smokeproof membranes, non-flammable transparent partitions, membrane materials for reinforcing roads, interiors (lighting, walls, brands, etc.), exteriors (tents, signs, etc.), automotive materials (canopies, vibration-damping materials, bodies, etc.), aircraft materials, ship materials, home appliance exteriors, tanks, filters, construction membrane materials, etc. In one embodiment, the laminate of the present disclosure is particularly suitable for use as a membrane material for membrane structure facilities, screens, signs, or solar radiation adjustment.

Claims (9)

A film containing a fluororesin;
a printing layer containing an alkali-soluble resin and a pigment on at least a portion of the film;
The content of the alkali-soluble resin is 1.0 to 15.0% by mass relative to the total mass of the printed layer. The laminate according to claim 1, wherein the printed layer further contains at least one resin selected from the group consisting of fluororesins and (meth)acrylic resins. The laminate according to claim 2, wherein the fluororesin in the printed layer is a copolymer having a fluoroolefin unit and a monomer unit having a hydroxyl group. The laminate according to claim 1 or 2, wherein the acid value of the alkali-soluble resin is 100 to 500 mg KOH/g. The laminate according to claim 1 or 2, wherein the pigment is an aluminum composite particle coated with a (meth)acrylic resin or silica. The laminate according to claim 1 or 2, for outdoor use. The laminate according to claim 1 or 2, which is at least one material selected from the group consisting of roofing materials, wall covering materials, and display materials. The laminate according to claim 1 or 2 is immersed in an alkaline solution to remove the printed layer, thereby obtaining a recycled film containing a fluororesin.
How recycled film is manufactured. The laminate according to claim 1 or 2 is impregnated with an alkaline solution to remove the printed layer, thereby obtaining a film containing the fluororesin,
The obtained film containing the fluororesin is melted and molded to obtain a recycled film containing the fluororesin.
How recycled film is manufactured.