Decorative sheet

Abstract

To provide a decorative sheet with reduced environmental load.SOLUTION: A decorative sheet 1 includes a paper substrate layer 10, a pattern layer 20 formed on the substrate layer 10, and a surface protective layer 30 formed on the pattern layer 20. The pattern layer 20 is formed by ink including a biomass material. The surface protective layer 30 is formed by a thermosetting resin including a biomass material and having an urethane bond.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a decorative sheet. [Background technology]

[0002] BACKGROUND ART Decorative sheets used for decorating interior materials for houses and the like, which are made of vinyl chloride resin, are known (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 5-278173 Summary of the Invention [Problem to be solved by the invention]

[0004] Recently, environmental issues have become a growing concern among companies and people around the world. Decorative sheets are no exception, and there is a growing demand for recyclable materials that reduce environmental impact.

[0005] An object of the present invention is to provide a decorative sheet that reduces the environmental impact. [Means for solving the problem]

[0006] The present invention is a decorative sheet comprising a paper substrate layer, a picture pattern layer formed on the substrate layer, and a surface protective layer formed on the picture pattern layer. The design layer is formed from ink containing biomass material. The surface protection layer contains a biomass material and is formed of a thermosetting resin having a urethane bond. [Effects of the Invention]

[0007] According to the present invention, a decorative sheet with reduced environmental impact can be provided. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a schematic cross-sectional view showing a decorative sheet according to one embodiment of the present invention. [Figure 2] FIG. 10 is a schematic cross-sectional view showing a decorative sheet according to a modified example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] One embodiment of the present invention will be described with reference to Fig. 1. The decorative sheet according to this embodiment is attached to the surface of a substrate such as a wood board, an inorganic board, or a metal plate, and imparts a desired appearance to the surface of the substrate.

[0010] As shown in FIG. 1, the decorative sheet 1 comprises a paper substrate layer 10, a picture pattern layer 20, and a surface protection layer 30.

[0011] Various known types of paper can be used, with tissue paper being typical, for the base layer 10. Because the design of the decorative sheet 1 does not depend on the base layer 10, there are no particular restrictions on the color, appearance, thickness, etc. of the base layer, but from the standpoint of ease of handling during printing, a thickness of approximately 10 μm to 200 μm is preferred.

[0012] The design layer 20 has a background color and pattern that constitute the design of the decorative sheet 1. The design layer 20 is formed using printing ink. In this embodiment, an ink containing a renewable and recyclable biomass material is used. Such inks typically use a biomass-derived nitrocellulose resin as the main binder, but other inks can also be used. There are no particular limitations on the biomass raw material, and examples include vegetable oil, pulp, and rice bran.

[0013] Any design can be selected as the design of the design pattern layer 20, and examples include wood grain, stone grain, fabric grain, abstract patterns, geometric patterns, letters, symbols, solid colors, and combinations thereof. There are no particular restrictions on the thickness of the picture pattern layer 20, but it can be, for example, 1 μm or more and 10 μm or less. A thickness of 1 μm or more makes it easier to print clearly. A thickness of 10 μm or less improves the printing workability when producing the decorative sheet 1, making it easier to keep production costs down. The picture pattern layer 20 may contain various functional additives such as extender pigments, plasticizers, dispersants, surfactants, tackifiers, adhesive aids, drying agents, curing agents, curing accelerators, and curing retarders, as appropriate, in order to impart various functions.

[0014] The surface protective layer 30 covers the picture pattern layer 20, thereby imparting to the decorative sheet 1 functions such as weather resistance, scratch resistance, stain resistance, and designability. The surface protective layer 30 can be formed of urethane (meth)acrylate, which is a resin composition containing at least a polyol, an isocyanate compound, and a hydroxy (meth)acrylate. In this embodiment, at least one of the polyol, the isocyanate compound, and the hydroxy (meth)acrylate that constitute the urethane (meth)acrylate contains a biomass-derived component. In other words, the surface protective layer 30 contains a biomass-derived component. At least one of the polyol, the isocyanate compound, and the hydroxy (meth)acrylate may or may not contain a biomass-derived component. In the following description, a urethane (meth)acrylate containing a biomass-derived component may be referred to as a biourethane (meth)acrylate.

[0015] Urethane (meth)acrylates are obtained, for example, by the reaction of a polyol and an isocyanate with a hydroxy (meth)acrylate. In biourethane (meth)acrylates, a plant-derived polyol can be used as the polyol, a plant-derived isocyanate can be used as the isocyanate, or both the polyol and the isocyanate can be plant-derived.

[0016] The polyol may be a polyester polyol, which is a reaction product of a polyfunctional alcohol and a polyfunctional carboxylic acid, a polyether polyol, which is a reaction product of a polyfunctional alcohol and a polyfunctional isocyanate, or a polycarbonate polyol, which is a reaction product of a polyfunctional alcohol and a carbonate. Each polyol will be described below.

[0017] <Polyester polyol> When the polyester polyol contains a biomass-derived component, at least one of the polyfunctional alcohol and the polyfunctional carboxylic acid contains a biomass-derived component. Examples of polyester polyols containing a biomass-derived component include the following. Reaction products of biomass-derived polyfunctional alcohols and biomass-derived polyfunctional carboxylic acids Reaction products of polyfunctional alcohols derived from fossil fuels and polyfunctional carboxylic acids derived from biomass Reaction products of biomass-derived polyfunctional alcohols and fossil fuel-derived polyfunctional carboxylic acids

[0018] Examples of biomass-derived polyfunctional alcohols that can be used include aliphatic polyfunctional alcohols obtained from plant materials such as corn, sugarcane, cassava, and sago palm. Examples of biomass-derived aliphatic polyfunctional alcohols include polypropylene glycol (PPG), neopentyl glycol (NPG), ethylene glycol (EG), diethylene glycol (DEG), butylene glycol (BG), and hexamethylene glycol, all of which can be obtained from plant materials by the following methods. These may be used alone or in combination.

[0019] Biomass-derived polypropylene glycol is produced by a fermentation method in which glucose is obtained by decomposing plant raw materials, via 3-hydroxypropylaldehyde (HPA) from glycerol. Compared to polypropylene glycol produced by the EO production method, polypropylene glycol produced by a biomethod such as the fermentation method is preferable in terms of safety, as useful by-products such as lactic acid can be obtained, and production costs can be kept low. Biomass-derived butylene glycol can be produced by producing glycol from plant raw materials, fermenting the glycol, obtaining succinic acid, and then hydrogenating the resulting succinic acid. Biomass-derived ethylene glycol can be produced, for example, from bioethanol obtained by a conventional method via ethylene.

[0020] The fossil fuel-derived polyfunctional alcohol may be a compound having two or more, preferably two to eight, hydroxyl groups per molecule. Specifically, the fossil fuel-derived polyfunctional alcohol is not particularly limited and may be any conventionally known alcohol. Examples of such alcohols include polypropylene glycol (PPG), neopentyl glycol (NPG), ethylene glycol (EG), diethylene glycol (DEG), butylene glycol (BG), and hexamethylene glycol, as well as triethylene glycol, dipropylene glycol, 1,4-cyclohexanedimethanol, trimethylolpropane, glycerin, 1,9-nonanediol, 3-methyl-1,5-pentanediol, polyether polyol, polycarbonate polyol, polyolefin polyol, and acrylic polyol. These may be used alone or in combination of two or more.

[0021] Examples of biomass-derived polyfunctional carboxylic acids include aliphatic polyfunctional carboxylic acids obtained from plant materials, such as renewable plant-derived oils such as soybean oil, linseed oil, tung oil, coconut oil, palm oil, and castor oil, as well as regenerated oils derived from recycled waste cooking oils containing these oils as a primary component. Examples of biomass-derived aliphatic polyfunctional carboxylic acids include sebacic acid, succinic acid, phthalic acid, adipic acid, glutaric acid, and dimer acid. For example, sebacic acid is produced by alkaline pyrolysis of ricinoleic acid obtained from castor oil, with heptyl alcohol as a by-product. In the present invention, it is particularly preferable to use biomass-derived succinic acid or biomass-derived sebacic acid. These may be used alone or in combination of two or more.

[0022] The fossil fuel-derived polyfunctional carboxylic acid may be an aliphatic polyfunctional carboxylic acid or an aromatic polyfunctional carboxylic acid. The fossil fuel-derived aliphatic polyfunctional carboxylic acid is not particularly limited and may be any conventionally known substance, such as adipic acid, dodecanedioic acid, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, itaconic anhydride, sebacic acid, succinic acid, glutaric acid, dimer acid, and ester compounds thereof. The fossil fuel-derived aromatic polyfunctional carboxylic acid is not particularly limited and may be any conventionally known substance, such as isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, phthalic anhydride, trimellitic acid, pyromellitic acid, and ester compounds thereof. These may be used alone or in combination of two or more.

[0023] <Polyether polyol> When the polyether polyol contains a biomass-derived component, at least one of the polyfunctional alcohol and the polyfunctional isocyanate contains a biomass-derived component. Examples of polyether polyols containing a biomass-derived component include the following. Reaction product of biomass-derived polyfunctional alcohol and biomass-derived polyfunctional isocyanate Reaction product of fossil fuel-derived polyfunctional alcohol and biomass-derived polyfunctional isocyanate Reaction products of biomass-derived polyfunctional alcohols and fossil fuel-derived polyfunctional isocyanates

[0024] As the biomass-derived polyfunctional alcohol and the fossil fuel-derived polyfunctional alcohol, the biomass-derived polyfunctional alcohol and the fossil fuel-derived polyfunctional alcohol described above in connection with the polyester polyol can be used.

[0025] Biomass-derived polyfunctional isocyanates can be obtained by converting plant-derived dicarboxylic acids into terminal amino groups through acid amidation and reduction, and then reacting the amidated dicarboxylic acids with phosgene to convert the amino groups into isocyanate groups. Examples of biomass-derived polyfunctional isocyanates include biomass-derived diisocyanates. Examples of biomass-derived diisocyanates include dimer acid diisocyanate (DDI), octamethylene diisocyanate, and decamethylene diisocyanate. Plant-derived diisocyanates can also be obtained by using plant-derived amino acids as raw materials and converting their amino groups into isocyanate groups. For example, lysine diisocyanate (LDI) can be obtained by methyl esterifying the carboxyl groups of lysine and then converting the amino groups into isocyanate groups. 1,5-pentamethylene diisocyanate can be obtained by decarboxylating the carboxyl groups of lysine and then converting the amino groups into isocyanate groups.

[0026] Other methods for synthesizing 1,5-pentamethylene diisocyanate include the phosgenation method and the carbamate method. More specifically, the phosgenation method involves directly reacting 1,5-pentamethylene diamine or a salt thereof with phosgene, or suspending pentamethylene diamine hydrochloride in an inert solvent and reacting it with phosgene to synthesize 1,5-pentamethylene diisocyanate. The carbamate method involves first carbamatizing 1,5-pentamethylene diamine or a salt thereof to generate pentamethylene dicarbamate (PDC), which is then thermally decomposed to synthesize 1,5-pentamethylene diisocyanate. A polyisocyanate that can be suitably used in the present invention is 1,5-pentamethylene diisocyanate-based polyisocyanate (trade name: STABIO (registered trademark)) manufactured by Mitsui Chemicals, Inc.

[0027] The fossil fuel-derived polyfunctional isocyanate is not particularly limited, and conventionally known substances can be used, and examples thereof include aromatic diisocyanates such as toluene-2,4-diisocyanate, 4-methoxy-1,3-phenylene diisocyanate, 4-isopropyl-1,3-phenylene diisocyanate, 4-chloro-1,3-phenylene diisocyanate, 4-butoxy-1,3-phenylene diisocyanate, 2,4-diisocyanate diphenyl ether, 4,4'-methylenebis(phenylene isocyanate) (MDI), jurylene diisocyanate, tolidine diisocyanate, xylylene diisocyanate (XDI), 1,5-naphthalene diisocyanate, benzidine diisocyanate, o-nitrobenzidine diisocyanate, and 4,4'-diisocyanate dibenzyl. Other examples include aliphatic diisocyanates such as methylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, and 1,10-decamethylene diisocyanate; and alicyclic diisocyanates such as 1,4-cyclohexylene diisocyanate, 4,4-methylenebis(cyclohexyl isocyanate), 1,5-tetrahydronaphthalene diisocyanate, isophorone diisocyanate, hydrogenated MDI, and hydrogenated XDI. These may be used alone or in combination of two or more.

[0028] <Polycarbonate polyol> When the polycarbonate polyol contains a biomass-derived component, the polycarbonate polyol can be a reaction product of a polyfunctional alcohol containing a biomass-derived component and a carbonate derived from a fossil fuel. Alternatively, the polycarbonate polyol can be a reaction product of a polyfunctional alcohol containing a fossil fuel-derived component and a carbonate containing a biomass-derived component. Examples of carbonates include dimethyl carbonate, dipropyl carbonate, diethyl carbonate, diethylene carbonate, dibutyl carbonate, ethylene carbonate, and diphenyl carbonate. These can be used alone or in combination of two or more.

[0029] As the biomass-derived polyfunctional alcohol, the biomass-derived polyfunctional alcohols described above in connection with the polyester polyol can be used.

[0030] <Isocyanate compounds> Next, the isocyanate compound will be described. As the isocyanate compound containing a biomass-derived component, the biomass-derived polyfunctional isocyanate described in the polyether polyol can be used.

[0031] <Hydroxy (meth)acrylate> Next, hydroxy(meth)acrylates will be described. Examples of hydroxy(meth)acrylates include hydroxy(meth)acrylates having one (meth)acryloyl group, such as hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, hydroxybutyl(meth)acrylate, and 2-hydroxy-3-phenoxypropyl(meth)acrylate; and hydroxy(meth)acrylates having two or more (meth)acryloyl groups, such as glycerin di(meth)acrylate, pentaerythritol tri(meth)acrylate, ditrimethylolpropane tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, and sorbitol penta(meth)acrylate. These may be used alone or in combination of two or more.

[0032] Furthermore, the surface protective layer 30 may be formed to contain nitrocellulose in addition to the above-mentioned biourethane (meth)acrylate. That is, the surface protective layer 30 may be formed from the above-mentioned biourethane (meth)acrylate, or may be formed by adding nitrocellulose to the biourethane (meth)acrylate.

[0033] <Nitrocellulose> Nitrocellulose is a nitro-substituted cellulose resin in which some of the hydroxyl groups in the cellulose skeleton are nitrated. The cellulose skeleton of nitrocellulose resin is a biomass material. While ordinary nitrocellulose can be used without any problems, it is particularly preferable to use nitrocellulose in which an average of 1.3 to 2.7 nitro groups are substituted per glucose unit constituting the cellulose skeleton.

[0034] Nitrocellulose is classified into L type and H type depending on the molecular weight. From the viewpoint of solubility in organic solvents, it is preferable to use L type.

[0035] The surface protective layer 30 preferably has a biomass ratio of 5% or more, more preferably 5% to 50%, and even more preferably 10% to 50%. If the biomass ratio is within the above range, the amount of fossil fuel used can be reduced, and the environmental load can be reduced. The weight of the surface protective layer 30 after drying is preferably 0.1 g / cm². 2 More than 15g / m 2 Less than 3g / m, more preferably 2 More than 10g / m 2 or less, more preferably 6 g / m 2 More than 9g / m 2 The surface protective layer 30 preferably has a thickness of 0.1 μm or more and 10 μm or less, more preferably 3 μm or more and 10 μm or less, and even more preferably 6 μm or more and 9 μm or less. Regarding the "biomass ratio," in the case of biourethane (meth)acrylate, for example, as described above, it is determined as a value measured by measuring the amount of carbon derived from biomass using radiocarbon (C14) measurement.

[0036] Regarding "biomass content," in the case of nitrocellulose, for example, there are three hydroxyl groups per glucose unit (formula weight = 172) that makes up the cellulose skeleton (the starting material), and one to three of these hydroxyl groups can be converted to nitrate esters (the hydrogen is replaced by a nitro group (non-biomass material, formula weight = 46)). If the original cellulose skeleton is made up of 100% biomass material by weight, and the average number of nitro groups replaced per glucose unit is n, then the proportion (mass %) of biomass material in the entire nitrocellulose molecule can be calculated as (172-n) x 100 / (172-n + 46n). The proportion of biomass material in the entire nitrocellulose molecule is approximately 78.8% by mass when each glucose unit constituting the cellulose backbone is substituted with an average of one nitro group, approximately 64.9% by mass when each glucose unit is substituted with two nitro groups, and approximately 55.0% by mass when each glucose unit is substituted with three nitro groups (values ​​calculated using the above formula).

[0037] The surface protection layer 30 is more preferably formed from a thermosetting resin having a urethane bond and using a biomass material. Examples of such resins include a cured mixture of a biomass-derived alkyd resin and an isocyanate compound, and a cured mixture of a polyester polyol, an isocyanate compound, and a hydroxy(meth)acrylate, any of which contains a biomass-derived component.

[0038] The surface protective layer 30 may contain various additives, such as weathering agents, plasticizers, stabilizers, fillers, dispersants, colorants such as dyes and pigments, solvents, ultraviolet absorbers, heat stabilizers, light stabilizers, antiblocking agents, catalyst scavengers, colorants, light scattering agents, and gloss adjusters, as needed. Furthermore, the surface protective layer 30 may contain functional additives, such as antibacterial agents and antifungal agents, as needed.

[0039] By having the above-described configuration, the decorative sheet 1 according to this embodiment has a biomass material ratio of 8% or more, which is close to the current upper limit, to the total weight of the organic components in the picture pattern layer 20 and the surface protective layer 30. As a result, not only can carbon dioxide emissions be reduced, but combined with the paper base layer 10, recycling is also easy.

[0040] Details will be shown in the examples, but as described above, the decorative sheet 1 of this embodiment has a reduced environmental impact, while also possessing solvent resistance, scratch resistance, and contamination resistance that are comparable to those of general decorative sheets that do not use biomass materials.

[0041] The decorative sheet according to this embodiment will be described in more detail using examples. The technical scope of the present invention is not limited solely by the specific content of the examples.

[0042] (Example) A 55.5 μm thick tissue paper was used as the base layer. A design layer was formed on one side of the base layer by gravure printing using a gravure printing ink whose main ingredient was biomass-derived nitrocellulose resin. Furthermore, a coating agent containing a biomass-derived alkyd resin and an isocyanate compound was applied onto the design layer and cured to form a surface protection layer made of a thermosetting resin having a urethane bond. The coating amount of the coating agent was 4.5 g / m 2 It was decided. In this manner, a decorative sheet according to the example was produced. In this decorative sheet, the ratio of biomass material to the total weight of organic components in the picture pattern layer and the surface protective layer was 8.2%.

[0043] (Comparative Example) A decorative sheet according to a comparative example was produced in the same manner as in the examples, except that a design layer was not provided and a surface protective layer was formed using a fossil fuel-derived acrylic UV-curable resin. This decorative sheet does not contain biomass materials.

[0044] The decorative sheets of each example were evaluated for the following items. (Solvent resistance test) Bemcot (registered trademark) soaked in methyl ethyl ketone was placed on the surface protective layer of each decorative sheet, and it was reciprocated 10 times without applying a load. Thereafter, the surface protective layer was visually evaluated according to which of the following criteria it met. ○ (Pass): No abnormalities were found in the surface protection layer × (Fail): Abnormalities were found in the surface protection layer

[0045] (Scratch resistance test: Hoffman scratch test) The decorative sheet according to each example was attached to MDF, and then the surface of each decorative sheet was scratched using a Hoffman scratch hardness tester while increasing the load from 25 g to 125 g in 25 g increments.

[0046] (Stain resistance) The decorative sheet according to each example was attached to MDF, and then the staining test for special plywood A of the JAS (Japanese Agricultural Standards) was carried out using blue ink, red crayon, and black magic marker. The evaluation was made on the following two levels, with only ○ being considered a pass. 〇(Good): No color residue × (Bad): Color remains The results are shown in Table 1.

[0047] [Table 1]

[0048] As shown in Table 1, it was confirmed that the decorative sheets according to the examples have various performance characteristics that are comparable to the decorative sheets of the comparative examples, which are equivalent to conventional products, despite having a high biomass ratio.

[0049] The present invention has been described above using embodiments and examples, but the specific configuration is not limited to these embodiments, and configuration changes and combinations within the scope that do not deviate from the gist of the present invention are also included.

[0050] For example, in the decorative sheet according to the present invention, a desired appearance and feel may be imparted by partially disposing a second protective layer 40 on a flat surface protective layer 30, as in the modified decorative sheet 1A shown in Figure 2. Examples of the appearance include an overall matte appearance and a three-dimensional appearance corresponding to the pattern of the picture pattern layer 20. The material of the second protective layer 40 may be the same as or different from that of the surface protective layer 30. In addition, since the volume of the second protective layer 40 may be significantly smaller than that of the surface protective layer 30, the second protective layer 40 does not necessarily need to contain a biomass material. [Explanation of symbols]

[0051] 1. 1A decorative sheet 10 Base material layer 20 Pattern layer 30 Surface protective layer 40 Second protective layer

Claims

1. a paper substrate layer; A picture pattern layer formed on the base layer; a surface protection layer formed on the picture pattern layer; Equipped with the design layer is formed using ink containing a biomass material, the surface protection layer contains a biomass material and is formed of a thermosetting resin having a urethane bond; Decorative sheet.

2. The ratio of biomass materials to the total weight of organic components of the picture pattern layer and the surface protective layer is 8% or more. The decorative sheet according to claim 1 .

3. a second protective layer formed on the surface protective layer and covering only a portion of the surface protective layer; The decorative sheet according to claim 1 .

Images