Stretchable film and topcoat composition

Abstract

Subject: To provide a stretchable film having a low-gloss appearance, wherein the low-gloss appearance does not easily change even when the film is stretched. Solution: The stretchable film of one embodiment of the present disclosure includes a surface layer comprising: a binder comprising a urethane resin; urethane resin beads having an average particle size of not less than 4 µm and not more than 20 µm; and nano-silica particles; wherein the surface gloss at 60 degrees is not more than 5 GU.

Description

[0001] This patent application is a divisional application of patent application No. 201880067907.6, filed on October 16, 2018, entitled "Stretchable Film and Surface Coating Composition". Technical Field

[0002] This disclosure relates to a stretchable film and surface coating composition that can be used in applications such as decoration. Background Technology

[0003] Decorative films are used for the purpose of decorating the interior and exterior of buildings, vehicles, etc. For example, known decorative films are formed by laminating a polyvinyl chloride (PVC) film with a printed layer onto a transparent PVC film, followed by an embossing process. By using various combinations of lamination and embossing processes, it can be made to exhibit the textures of various materials such as wood grain, metal, fabric, and marble.

[0004] For example, Patent Document 1 (JP 2011-255552A) describes “an embossed decorative sheet obtained by an embossing process on the surface of a decorative sheet, wherein a surface protective layer is disposed on the surface side of the decorative sheet, the surface protective layer comprising synthetic resin beads containing curable resin, the embossing process having an average amplitude of 15µm to 50µm, and the synthetic resin beads having an average particle size of 8µm to 20µm.”

[0005] Patent document 2 (WO 2008 / 129667) describes “a decorative sheet having a protective layer, the protective layer being mainly composed of a transparent resin component disposed on the surface of a printed layer disposed on a printed sheet, wherein the protective layer includes a first protective layer disposed on the printed layer of the printed sheet and a second protective layer containing transparent or translucent spherical particles disposed on a given area of ​​the first protective layer, and the gloss of the protruding surface of the first protective layer is lower than the gloss of the surface of the second protective layer.”

[0006] Existing art literature

[0007] Patent documents

[0008] Patent Document 1: JP 2011-255552 A

[0009] Patent Document 2: WO 2008 / 129667 Summary of the Invention

[0010] The problem that this invention will solve

[0011] Recently, there has been a demand for stretchable films with a low-gloss appearance that can mimic the surface of dried finished wood, matte finishes, and the like.

[0012] In known methods, decorative films with a low-gloss appearance are formed by coating a surface layer of resin containing microparticles or beads. These decorative films can be used for exterior or interior decoration of buildings, interior decoration of vehicles, furniture, product surface decoration, etc. In many cases, it is necessary to stretch the film to conform to the shape of the product to which it is adhered. However, it is very difficult to form a stretchable film with a low-gloss appearance because the surface structure changes and the gloss increases when the film is stretched.

[0013] This disclosure provides a stretchable film with a low-gloss appearance, wherein the low-gloss appearance is not easily changed even when the film is stretched.

[0014] Methods for solving problems

[0015] According to one embodiment, a stretchable film is provided, the stretchable film comprising a surface layer containing: an adhesive comprising urethane resin; urethane resin beads having an average particle size of not less than 4 µm and not more than 20 µm; and nano-silica particles, wherein the surface gloss at 60 degrees is not greater than 5 GU.

[0016] According to another embodiment, a surface coating composition is provided, comprising: an adhesive precursor comprising a urethane resin composition; urethane resin beads having an average particle size of not less than 4 µm and not more than 20 µm; and nano-silica particles.

[0017] Effects of the present invention

[0018] Because the stretchable film of this disclosure has a low-gloss appearance, which is not easily changed even when the film is stretched, it can be advantageously used in the interior and exterior decoration of buildings, vehicles, etc. Furthermore, the use of the surface coating composition of this disclosure makes it possible to form a stretchable surface layer with low gloss on a substrate surface, wherein the low-gloss appearance is not easily changed even when stretched.

[0019] It should be noted that the above description should not be construed as disclosing all embodiments of the invention or all advantages related to the invention. Attached Figure Description

[0020] Figure 1 This is a schematic cross-sectional view of a stretchable membrane according to one embodiment of this disclosure.

[0021] Figure 2A These are photographs depicting the stretchable films of Example 1, Comparative Example 1, and Comparative Example 2 in order from top to bottom before stretching.

[0022] Figure 2B These are photographs depicting the stretchable films of Example 1, Comparative Example 1, and Comparative Example 2, sequentially from top to bottom, after being stretched by 150%. Detailed Implementation

[0023] The following provides a more detailed description to illustrate typical embodiments of the invention, and the invention is not limited to these embodiments.

[0024] In this disclosure, "transparent" means that the total light transmittance of a material or product is not less than about 85% in the wavelength range of 400 nm to 700 nm; "semi-transparent" means that the total light transmittance of a material or product is not less than about 20% and less than about 85% in the wavelength range of 400 nm to 700 nm; and "opaque" means that the total light transmittance of a material or product is less than about 20% in the wavelength range of 400 nm to 700 nm. The total light transmittance is determined according to JIS K7361-1: 1997 (ISO 13468-1:1996).

[0025] In one embodiment, the stretchable film includes a surface layer comprising: an adhesive comprising a urethane resin composition; urethane resin beads having an average particle size of not less than 4 µm and not more than 20 µm; and nano-silica particles. The surface gloss of the stretchable film at 60 degrees Celsius is not greater than about 5 GU. The surface layer containing urethane resin beads and nano-silica particles with an average particle size within the above range imparts low gloss and good appearance retention after stretching to the stretchable film.

[0026] Figure 1 A schematic cross-sectional view of the stretchable membrane of this disclosure is shown. Figure 1 The stretchable membrane 100 includes a surface layer 10 and a base layer 20, the base layer being an optional component. The stretchable membrane 100 can be formed solely from the surface layer 10. That is, the surface layer 10 itself can be a stretchable membrane. The surface layer 10 contains: an adhesive 12 containing urethane resin; urethane resin beads 14 having an average particle size of not less than 4 µm and not more than 20 µm; and nano-silica particles 16.

[0027] The adhesive contains urethane resin. Various known urethane resins can be used as urethane resins. Urethane resins can be obtained by drying or curing the urethane resin composition. The urethane resin composition can be an aqueous or non-aqueous system. This is advantageous when the urethane resin is a cured product of a two-component urethane resin composition. Two-component urethane resin compositions are generally non-aqueous urethane resin compositions. By using a two-component resin composition when forming the surface layer, the other components of the surface layer (such as urethane resin beads, nano-silica particles) form chemical bonds with the urethane resin, preventing or inhibiting the loss of these particles and the exudation of components from the surface layer.

[0028] Two-component urethane resin compositions generally contain polyols as base compounds and polyfunctional isocyanates as curing agents, and may contain catalysts and / or solvents as needed.

[0029] Polyester polyols, such as polycaprolactone diol and polycaprolactone triol; polycarbonate polyols, such as cyclohexanediol carbonate and 1,6-hexanediol carbonate; and combinations thereof, can be used. These polyols can impart transparency, weather resistance, strength, chemical resistance, etc., to the surface layer. Specifically, polycarbonate polyols can form surface layers with high transparency and chemical resistance. From the perspective of imparting stretchability to the surface layer without forming an overly cross-linked structure, the polyol is preferably a diol. Polyester diols and polycarbonate diols, especially polycarbonate diols, can be advantageously used.

[0030] The OH value of polyols can generally be no less than about 10 mg / KOH, no less than about 20 mg / KOH, or no less than about 30 mg / KOH, and no greater than about 150 g / KOH, no greater than about 130 g / KOH, or no greater than about 120 mg / KOH.

[0031] Examples of polyfunctional isocyanates include aliphatic polyisocyanates, alicyclic polyisocyanates, aromatic polyisocyanates, aromatic-aliphatic polyisocyanates, and oligomers (dimers, trimers, etc.) of these polyisocyanates, biuret-modified compounds, urethane-modified compounds, polyol-modified compounds, oxadiazinetrione-modified compounds, carbodiimide-modified compounds, etc. From the perspective of imparting stretchability to the surface layer without forming an overly cross-linked structure, diisocyanates are preferred polyfunctional isocyanates. Examples of such diisocyanates include aliphatic diisocyanates, such as tetramethylene diisocyanate and hexamethylene diisocyanate (HDI); alicyclic diisocyanates, such as isophorone diisocyanate, trans, trans, trans, cis, and cis, cis dicyclohexylmethane-4,4'-diisocyanate and mixtures thereof (hydrogenated MDI); and aromatic diisocyanates, such as 2,4-toluene diisocyanate and 2,6-toluene diisocyanate, and these toluene diisocyanates (TDI). Mixtures of isomers, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and 2,2'-diphenylmethane diisocyanate, and mixtures of isomers of these diphenylmethane diisocyanates (MDI); and aromatic-aliphatic polyisocyanates, such as 1,3- or 1,4-xylene diisocyanate or mixtures thereof (XDI), and 1,3- or 1,4-tetramethylxylene diisocyanate or mixtures thereof (TMXDI).

[0032] As the equivalent ratio of polyol to polyisocyanate, the polyisocyanate in each 1 equivalent of polyol is generally not less than about 0.6 equivalents or not less than about 0.7 equivalents, and not more than about 2 equivalents or not more than about 1.2 equivalents.

[0033] As a catalyst, those commonly used to form urethane resins can be used, such as di-n-butyltin dilaurate, zinc naphthenate, zinc octenate, triethylenediamine, etc. The amount of catalyst used is generally not less than about 0.005 parts by weight or not less than about 0.01 parts by weight, and not more than about 0.5 parts by weight or not more than 0.2 parts by weight, based on 100 parts by weight of the two-component urethane resin composition.

[0034] The binder may also contain cellulose esters. Including cellulose esters in the binder increases the viscosity of the binder during drying and reduces surface flowability, thereby making it possible to uniformly spread the binder precursor containing urethane resin beads. Examples of cellulose esters include cellulose propionate acetate and cellulose butyrate acetate.

[0035] Considering solubility in solvents, the molecular weight of cellulose esters can generally be not less than about 12,000, not less than about 16,000, or not less than about 20,000, and not greater than about 110,000, not greater than about 100,000, or not greater than about 90,000.

[0036] Considering shape retention at operating temperatures, the glass transition temperature (Tg) of cellulose esters is generally not lower than about 85°C, not lower than about 96°C, or not lower than about 101°C, and not higher than about 190°C, not higher than about 180°C, or not higher than about 160°C.

[0037] In several embodiments, the adhesive, based on 100 parts by weight of the adhesive, may contain not less than about 5 parts by weight, not less than about 10 parts by weight, or not less than about 15 parts by weight, and not more than about 35 parts by weight, not more than about 30 parts by weight, or not more than about 25 parts by weight. By setting the blending amount of cellulose ester within the above range, urethane resin beads can be more uniformly dispersed in the surface layer, and the surface layer can be given a uniform low-gloss appearance.

[0038] The surface layer of this embodiment contains urethane resin beads. Due to the presence of these beads on the membrane surface, fine indentations and protrusions are formed, resulting in a low-gloss structure on the membrane surface. Furthermore, because of their good affinity with the urethane resin-containing adhesive, the urethane resin beads exhibit high adhesion to the adhesive. Therefore, the urethane resin beads can be prevented from detaching from the adhesive when the membrane is stretched or deformed.

[0039] Crosslinked polyurethane microparticles obtained through suspension polymerization, seed polymerization, emulsion polymerization, etc., can be used as urethane resin beads. Urethane resin beads have excellent flexibility, toughness, and scratch resistance, and these characteristics can be imparted to the surface layer.

[0040] The average particle size of the urethane resin beads is preferably not less than about 4 µm and not more than about 20 µm. In some embodiments, the average particle size of the urethane resin beads may be not less than about 6 µm or not less than about 10 µm, and not more than about 10 µm or not more than about 15 µm. When the average particle size of the urethane resin beads is less than about 4 µm, whitening of the film surface due to light scattering is likely to occur. When the average particle size of the urethane resin beads is greater than about 20 µm, gloss is easily produced and low gloss is difficult to obtain. Urethane resin beads having an average particle size within the above range can impart low brightness to the surface layer, i.e., low gloss and low whiteness, because they scatter light incident on the surface to an appropriate degree.

[0041] In several embodiments, the surface layer based on 100 parts by weight of the adhesive may contain not less than about 70 parts by weight, not less than about 80 parts by weight, or not less than about 100 parts by weight, and not more than about 240 parts by weight, not more than about 230 parts by weight, or not more than about 200 parts by weight. When the blend amount of urethane resin beads is less than about 70 parts by weight, it is difficult to obtain a low gloss. When it is greater than about 240 parts by weight, whitening is likely to occur. By setting the blend amount of urethane resin beads within the above range, a surface layer exhibiting low gloss over a wide viewing angle range (e.g., 20 degrees to 85 degrees) can be obtained.

[0042] The surface layer of this embodiment also contains nano-silica particles. The nano-silica particles present in the binder suppress changes in low gloss and effectively prevent film whitening, which is prone to occur when the film is stretched in the presence of individual urethane resin beads.

[0043] Examples of nano-silica particles include silica sols obtained using water glass (sodium silicate solution) as a starting material. The surface of nano-silica particles can be modified with surface treatment agents such as silanes, alcohols, amines, carboxylic acids, sulfonic acids, phosphonic acids, or titanates.

[0044] In several embodiments, the average particle size of the nano-silica particles can be not less than about 10 nm, not less than about 20 nm, or not less than about 30 nm, and not greater than about 100 nm, not greater than about 75 nm, or not greater than about 45 nm. By using such tiny nano-silica particles, the nano-silica particles can be highly dispersed in the surface layer. Even when the film is stretched, the loss of low gloss is suppressed, and film whitening is effectively prevented because the tiny nano-silica particles remain dispersed in the stretched portion. It is also possible that the nano-silica particles in contact with the urethane resin beads act as some type of physical crosslinking point between the urethane beads and the binder. The presence of nano-silica particles that can act as physical crosslinking points can suppress the loss of urethane beads and effectively prevent film whitening when the film is stretched.

[0045] In several embodiments, based on 100 parts by weight of adhesive, the surface layer may contain not less than about 5 parts by weight, not less than about 10 parts by weight, or not less than about 20 parts by weight, and not more than about 120 parts by weight, not more than about 110 parts by weight, or not more than about 100 parts by weight of nano-silica particles. By setting the blending amount of nano-silica particles within the above range, a low-gloss appearance is maintained even when the stretchable film is stretched. For example, an increase in brightness, i.e., whitening, when the film is stretched by 150%, can be prevented or suppressed. Furthermore, setting the blending amount of nano-silica particles within the above range makes it possible to impart excellent scratch resistance to the surface layer.

[0046] The surface layer may also contain a silicone-modified polymer containing functional groups capable of reacting with isocyanates or hydroxyl groups. When finger oil adheres to a low-gloss surface, its traces are easily visible. The inclusion of a silicone-modified polymer containing functional groups capable of reacting with isocyanates or hydroxyl groups in the surface layer makes it possible to increase the fingerprint resistance of the surface layer. The silicone-modified polymer imparts scratch resistance to the surface layer by reducing its coefficient of friction and making it smooth. The isocyanate or hydroxyl groups of the silicone-modified polymer can react with the hydroxyl groups or isocyanate groups of the urethane resin in the adhesive or urethane resin beads to bond the silicone-modified polymer to the urethane resin or urethane resin beads. In this embodiment, the exudation of the silicone-modified polymer from the surface layer can be prevented or inhibited.

[0047] Examples of organosilicon-modified polymers containing functional groups capable of reacting with isocyanate or hydroxyl groups include organosilicon-modified polymers such as polyether-modified organosilicon, polyester-modified organosilicon, aralkyl-modified organosilicon, acrylic-modified organosilicon, organosilicon-modified polyacrylate, and urethane-modified organosilicon. Examples of functional groups capable of reacting with the isocyanate or hydroxyl groups of organosilicon-modified polymers include hydroxyl groups, amino groups with active carbon, isocyanate groups, epoxy groups, anhydride groups, etc. Organosilicon-modified polyacrylates are advantageous as organosilicon-modified polymers due to their particularly excellent fingerprint resistance. Organosilicon-modified polymers preferably contain hydroxyl groups or isocyanate groups, especially hydroxyl groups, which have high reactivity with isocyanates or hydroxyl groups.

[0048] In several embodiments, based on 100 parts by weight of adhesive, the surface layer may contain not less than about 0.1 parts by weight, not less than about 0.5 parts by weight, or not less than about 1.0 parts by weight, and not more than about 15 parts by weight, not more than about 12 parts by weight, or not more than about 10 parts by weight of a silicone-modified polymer containing functional groups capable of reacting with isocyanates or hydroxyl groups, such as a silicone-modified polyacrylate. Setting the blending amount of the silicone-modified polymer within the above range makes it possible to further increase either or both of the fingerprint resistance and scratch resistance of the surface layer.

[0049] As other optional components, the surface layer may contain additives such as fillers, UV absorbers, light stabilizers, heat stabilizers, dispersants, plasticizers, flow improvers, and homogenizers, in addition to urethane resin beads and nano-silica particles. The individual and total amounts of these additives can be determined within a range that maintains the desired characteristics of the surface layer.

[0050] The surface coating can be formed using a surface coating composition comprising: a binder precursor comprising the above-described urethane resin composition; urethane resin beads having an average particle size of not less than 4 µm and not more than 20 µm; and nano-silica particles.

[0051] In addition to urethane resin compositions, adhesive precursors may also contain the aforementioned cellulose esters used in adhesives. Cellulose esters can impart rapid drying ability, tack-drying ability, flowability, or homogenization ability to the surface coating composition. Cellulose esters may also be used to adjust the viscosity of the surface coating composition.

[0052] The surface coating composition may also contain the aforementioned silicone-modified polymer, which contains functional groups capable of reacting with isocyanate or hydroxyl groups. The isocyanate or hydroxyl groups of the silicone-modified polymer can react with the hydroxyl or isocyanate groups of the urethane resin composition or urethane resin beads, thereby bonding the silicone-modified polymer to the urethane resin or urethane resin beads. Therefore, the exudation of the silicone-modified polymer from the surface layer can be prevented or inhibited. From a reactivity perspective, this is advantageous when the urethane resin composition is a two-component urethane resin composition, especially when using a silicone-modified polymer.

[0053] The blending of the surface coating composition is as described with respect to the surface layer. While changing "100 parts by weight of binder" to "100 parts by weight of binder precursor", blending amounts of cellulose ester, urethane resin beads, nano-silica particles, and an organosilicon-modified polymer containing functional groups capable of reacting with isocyanates or hydroxyl groups are applied.

[0054] To improve processability, coatability, etc., the surface coating composition may also contain solvents such as ketones, such as methyl ethyl ketone, methyl isobutyl ketone, and acetylacetone; aromatic hydrocarbons, such as toluene and xylene; alcohols, such as ethanol and isopropanol; esters, such as ethyl acetate and butyl acetate; and ethers, such as tetrahydrofuran, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate (1-methoxy-2-propyl acetate), and dipropylene glycol monomethyl ether acetate. The amount of solvent blended in the surface coating composition is generally not less than about 20 parts by weight or not less than about 30 parts by weight, and not more than about 60 parts by weight or not more than about 50 parts by weight, based on 100 parts by weight of the binder precursor.

[0055] The viscosity of the surface coating composition is generally not less than about 20 mPa·s, not less than about 50 mPa·s, or not less than about 100 mPa·s, and not greater than about 1000 mPa·s, not greater than about 800 mPa·s, or not greater than about 600 mPa·s. The viscosity of the surface coating composition is measured using a Type B viscometer with a suitable spindle at a rotation speed of 60 rpm.

[0056] The surface layer can be formed by coating the substrate with a surface coating composition using a doctor blade coater, doctor bar coater, knife coater, air knife coater, roller coater, casting coater, etc., and by either or both of drying and curing by heating at about 80°C to 150°C as needed.

[0057] The thickness of the surface layer may be, for example, not less than about 3 µm, not less than about 5 µm, or not less than about 10 µm, and not greater than about 50 µm, not greater than about 30 µm, or not greater than about 20 µm. In this disclosure, the thickness of the surface layer refers to the thickness of the thickest portion, i.e., the maximum thickness.

[0058] In several embodiments, the surface layer is transparent or translucent. In these embodiments, the total light transmittance of the surface layer in the wavelength range of 400 nm to 700 nm is not less than about 80%, not less than about 85%, or not less than about 90%. In these embodiments, decorations, such as printing applied to the substrate, are visible through the surface layer.

[0059] The stretchable membrane may also contain a stretchable base layer as a substrate. As the stretchable base layer, one or more resin layers may be used, which are selected from polyvinyl chloride, polyurethane, polyethylene, polypropylene, vinyl chloride-vinyl acetate resin, acrylic resin, cellulose resin and fluoropolymer.

[0060] The stretchable substrate can be colored or colorless. It can be opaque, translucent, or transparent. The stretchable substrate can have a substantially smooth surface or a structured surface that can be formed through surface treatments such as embossing. Due to the appearance or shape of the stretchable substrate as described above, it is possible to impart a variety of decorative features to the stretchable film.

[0061] In one embodiment, the stretchable base layer comprises a transparent polyvinyl chloride (PVC) resin layer and a colored PVC resin layer. In the stretchable film of this embodiment, the colored PVC resin layer can be supported or protected by the transparent PVC resin layer and can impart durability to the decorative features of the stretchable film. The stretchable film of this embodiment can be advantageously used in applications in which the stretchable film is adhered to, for example, interior or exterior decorative components of buildings or vehicles.

[0062] The thickness of the stretchable substrate can be, for example, not less than about 25µm, not less than about 50µm, or not less than about 80µm, and not greater than about 5mm, not greater than about 1mm, or not greater than about 0.5mm.

[0063] In several embodiments, the tensile elongation of the stretchable substrate is not less than about 10%, not less than about 20%, or not less than about 30%, and not greater than about 400%, not greater than about 350%, or not greater than about 300%. The tensile elongation of the stretchable substrate is obtained by preparing a sample 25 mm wide and 150 mm long, stretching it until fracture at a temperature of 20°C, a tensile speed of 300 mm / min, and a carrier distance of 100 mm, and calculating {[carrier distance at fracture (mm) - carrier distance before elongation (mm) (= 100 mm)] / carrier distance before elongation (mm) (= 100 mm)} × 100 (%).

[0064] The stretchable base layer may also have an adhesive layer on the side opposite to the surface layer. As the adhesive layer, commonly used solvent-based, emulsion-based, pressure-sensitive, heat-sensitive, thermosetting, or UV-curable adhesives may be used, such as acrylic-based adhesives, polyolefin-based adhesives, polyurethane-based adhesives, polyester-based adhesives, or rubber-based adhesives. The thickness of the adhesive layer is generally not less than about 5µm, not less than about 10µm, or not less than about 20µm, and not greater than about 100µm, not greater than about 80µm, or not greater than about 50µm.

[0065] The liner may be disposed on the surface of the adhesive layer. Examples of liners include paper; plastic materials such as polyethylene, polypropylene, polyester, and cellulose acetate; and paper coated with such plastic materials. The liner may also have a surface that has been peeled with silicone or the like. The thickness of the liner is generally not less than about 5 µm, not less than about 15 µm, or not less than about 25 µm, and not greater than about 500 µm, not greater than about 300 µm, or not greater than about 250 µm.

[0066] In one embodiment, the surface gloss of the stretchable film is no greater than about 5 GU when the measurement angle is 60 degrees. In several embodiments, the surface gloss of the stretchable film at 60 degrees is no greater than about 0.7 GU, no greater than about 0.5 GU, or no greater than about 0.3 GU.

[0067] In one embodiment, the surface gloss of the stretchable film is no greater than about 0.2 GU at 20 degrees, no greater than about 0.7 GU at 60 degrees, and no greater than about 5.0 GU at 85 degrees. In several embodiments, the surface gloss of the stretchable film is no greater than about 0.2 GU at 20 degrees, no greater than about 0.5 GU at 60 degrees, and no greater than about 4.5 GU at 85 degrees, or no greater than about 0.1 GU at 20 degrees, no greater than about 0.3 GU at 60 degrees, and no greater than about 4.0 GU at 85 degrees. Because the surface gloss of the stretchable film is a combination of the above ranges, reflection of light incident on the stretchable film at various angles can be suppressed, and the decorative effect of the stretchable film can be seen from a wide viewing angle range.

[0068] In several embodiments, the brightness of the stretchable film is measured using a spectrophotometer with a D65 / 10 light source having SCI mirror treatment and 0% UV reflection. Not greater than about 23, not greater than about 22.5, or not greater than about 22.0.

[0069] In several implementations, the brightness of the stretchable film before stretching is taken as... 1. The brightness after 150% stretching is taken as... 2, and the brightness difference is taken as At that time, the difference in brightness Not greater than about 3, not greater than about 2.5, or not greater than about 2.0. equal 2 minus 1. In this embodiment, whitening of the stretchable film is suppressed when it is stretched. To this end, when the stretchable film is applied to a surface while being bent or stretched, the decorative features of the stretchable film can be maintained even at the bent or stretched portions.

[0070] The applications of the stretchable membrane disclosed herein are not particularly limited. For example, the stretchable membrane of this disclosure can be used as an interior decorative component for walls, stairs, ceilings, columns, finishes, etc., or as an exterior decorative component for exterior walls, etc. Furthermore, it can be used for the interior and exterior decoration of various transport vehicles, such as railway vehicles, ships, airplanes, and automobiles (including two-wheeled and four-wheeled vehicles). Additionally, it can also be used as a surface decoration for any product, such as road signs, billboards, furniture, appliances, etc.

[0071] Example

[0072] Specific embodiments of this disclosure are shown in the following examples, but the invention is not limited thereto. Unless otherwise specified, all parts and percentages are by mass. Numerical values ​​include errors inherent in the measurement principles and measuring equipment. Numerical values ​​are represented by significant digits rounded using typical methods.

[0073] The materials, reagents, etc. used in these embodiments are shown in Table 1.

[0074]

[0075] transparent resin base layer

[0076] A polyethylene terephthalate (PET) film was preheated and laminated onto a polyvinyl chloride (PVC) film with a measured thickness of 80 µm to obtain a transparent resin substrate layer. The PVC film composition was PVC / ester-based plasticizer / organic stabilizer (acrylic resin, zinc stearate, etc.) = 72 / 16 / 12 (mass ratio). The PET film was Teijin Tetoron G2 film with a thickness of 50 µm (Teijin FilmSolutions Ltd., Chiyoda-ku, Tokyo, Japan).

[0077] Example 1

[0078] The mixture having the composition shown in Table 2 was mixed for 3.5 min using a planetary centrifugal mixer (Thinky Corporation, Chiyoda-ku, Tokyo, Japan) to obtain a surface coating composition. A PVC film with a transparent resin substrate was coated with the surface coating composition using a doctor blade coater with a 40 µm gap. The PVC film was then dried and cured in an oven at 65 °C for 2 min, and then dried and cured in an oven at 120 °C for 5 min to form a surface layer with a dry thickness of approximately 12 µm. A PET film was peeled off from the obtained film and laminated with an 80 µm thick black PVC film (PVC / ester-based plasticizer / organic stabilizer, pigments, etc. (acrylic resin, zinc stearate, etc.) = 72 / 16 / 12 (mass ratio)). The film was then extruded using heated rollers at a pad speed of 7 m / min at an extrusion pressure of 0.2 MPa and a temperature of 60 °C.

[0079] Examples 2 to 5

[0080] The surface coating composition was prepared in the same manner as in Example 1, and a stretchable film was obtained, except that the blending amounts of nano-silica particles and urethane resin beads varied as shown in Table 2.

[0081] Examples 6 to 8

[0082] The surface coating composition was prepared in the same manner as in Example 1, and a stretchable film was obtained, except that the type of nano-silica particles was changed.

[0083] Comparative Example 1

[0084] A stretchable film was obtained in the same manner as in Example 1, except that no surface layer was formed.

[0085] Comparative Example 2

[0086] A commercially available matte-toned decorative film (brand name DI NOC (trade name) film PS-1183MT (3M Japan Ltd., Shinagawa-ku, Tokyo, Japan)) is used as a stretchable film without modification.

[0087] Comparative Example 3

[0088] The surface coating composition was prepared in the same manner as in Example 1 and a stretchable film was obtained, except that nano-silica particles were not used and the blending amount of urethane resin beads was varied as shown in Table 2.

[0089] Comparative Example 4

[0090] The surface coating composition was prepared in the same manner as in Example 1 to obtain a stretchable film, except that the urethane resin beads were replaced with acrylic resin beads and the blending amounts were varied as shown in Table 2.

[0091]

[0092] [Table 2-2]

[0093] (Table 2 continued)

[0094] Surface gloss

[0095] For Examples 1 to 8, Comparative Examples 1 to 4, and Reference Examples 1 to 15, surface gloss was measured using a portable gloss meter, BYK-Gardner micro-TRI-gloss (BYK Chemical Japan Co., Ltd., Shinjuku-ku, Tokyo, Japan), at measurement angles of 20 degrees, 60 degrees, and 85 degrees. When the surface gloss at 60 degrees was no greater than 5 GU, the actual low-gloss conditions were considered satisfactory. Furthermore, when the surface gloss met all three conditions—no greater than 0.2 GU at a measurement angle of 20 degrees, no greater than 0.7 GU at 60 degrees, and no greater than 5.0 GU at 85 degrees—the samples exhibited a very good low-gloss surface appearance.

[0096] Surface colorimetry

[0097] For Examples 1 to 8, Comparative Examples 1 to 4, and Reference Examples 1 to 15, the luminance was measured using a D65 / 10 light source with SCI mirror treatment and 0% ultraviolet reflection using a spectrophotometer CM-3700d (Konica Minolta Japan, Inc., Minato-ku, Tokyo, Japan). When brightness When the value is no greater than 23, the brightness can be assessed as good, with low gloss.

[0098] Brightness after 150% stretch

[0099] For Examples 1 to 8 and Comparative Examples 1 to 4, samples pre-cut to 150 mm × 15 mm were stretched by 150% at a speed of 100 mm / min in an environment of 20°C and 60% relative humidity using a Tensilon RTC-1210A universal testing instrument (A&D Co., Ltd., Toyoshima-ku, Tokyo, Japan). Surface colorimetry was performed on the samples after stretching. The brightness difference was calculated. The brightness before stretching is taken as 1. The brightness after 150% stretching is taken as... 2, and the brightness difference is taken as , equal 2 minus 1. When the brightness difference When the value is no greater than 3, the change in low gloss caused by stretching can be assessed as minimal.

[0100] fingerprint resistance

[0101] For Example 1, the fingerprint resistance of the surface layer was evaluated using an artificial fingerprint oil solution. The artificial fingerprint oil solution was dropped onto the surface and rubbed back and forth with a cotton swab for 100 cycles. Afterward, the solution was wiped off with a dry or damp paper towel. The surface color remained essentially unchanged, and it exhibited good fingerprint resistance.

[0102] Scratch resistance

[0103] For Example 1, the abrasion resistance of the surface layer was evaluated using a steel wool abrasion test. #0000 steel wool with a head area of ​​7.6 cm (3 inches) in diameter was used to rub the surface layer back and forth for 10 cycles under a load of 500 g. Afterward, the sample was rinsed with water to remove the steel wool particles, and the surface layer was visually observed after wiping away any remaining water with a paper towel. No visible scratches were observed, and the sample exhibited good abrasion resistance.

[0104] Adhesion characteristics

[0105] For Example 1, adhesion characteristics were evaluated using a cross-section method according to JIS K5600-5-6: 1999. A 5 × 5 grid with a 1 mm spacing was formed using 851 silicone tape (3M Japan Ltd., Shinagawa-ku, Tokyo, Japan). No separation, peeling, or cracking between layers was observed on the surface, and the sample exhibited good adhesion characteristics.

[0106] The evaluation results of the stretchable membranes of Examples 1 to 8 and Comparative Examples 1 to 4 are shown in Table 3. Figure 2A These are photographs depicting the stretchable films of Example 1, Comparative Example 1, and Comparative Example 2 in order from top to bottom before stretching. Figure 2B These are photographs depicting the appearance after being stretched by 150% in the same order. The stretchable film of Example 1 exhibits low gloss and does not turn white even after stretching. The stretchable film of Comparative Example 1 exhibits high gloss. In the stretchable film of Comparative Example 2, whitening was observed after stretching.

[0107] Table 3

[0108] Refer to Examples 1 to 15

[0109] Surface coating compositions were prepared using the compositions shown in Table 4 in the same manner as in Example 1, and stretchable films were obtained for examining the relationship between the type, average particle size, and blending amount of urethane resin beads, as well as the type of binder, and surface gloss and brightness. The surface coating compositions of these reference examples do not contain nano-silica particles.

[0110]

[0111] The evaluation results of the stretchable membranes of Examples 1 to 15 are shown in Table 5.

[0112] Table 5

[0113] [Reference Number]

[0114] 100 Stretchable Film

[0115] 10 Surface layer

[0116] 12 Adhesive

[0117] 14. Carbamate resin beads

[0118] 16-nanometer silica particles

[0119] 20 Basal layer

Claims

1. A stretchable membrane, the stretchable membrane comprising a surface layer, the surface layer comprising: Adhesive, said adhesive comprising urethane resin; The urethane resin beads, wherein the amount of the urethane resin beads is calculated based on 100 parts by weight of the binder to be not less than 100 parts by weight and not more than 240 parts by weight, and the urethane resin beads have an average particle size of not less than 4 µm and not more than 20 µm; and Nano-silica particles, wherein the amount of said nano-silica particles is calculated based on 100 parts by weight of said binder as not less than 20 parts by weight and not more than 120 parts by weight; The surface gloss at 60 degrees is no greater than 0.5 GU.

2. The stretchable membrane according to claim 1, wherein the average particle size of the nano-silica particles is not less than 10 nm and not greater than 100 nm.

3. The stretchable membrane according to claim 1, wherein, based on 100 parts by weight of the adhesive, the surface layer comprises not less than 20 parts by weight and not more than 110 parts by weight of the nano-silica particles.

4. The stretchable film according to claim 1, wherein the brightness of the stretchable film before stretching is taken as...

1. The brightness after 150% stretching is taken as... 2, and the brightness difference is taken as At that time, the brightness difference No more than 3 equal 2 minus 1.

5. The stretchable membrane according to claim 1, wherein the binder further comprises a cellulose ester.

6. The stretchable membrane according to claim 1, wherein the urethane resin comprises a cured product of a two-component urethane resin composition.

7. The stretchable membrane according to claim 1, wherein the surface layer further comprises a silicone-modified polymer containing functional groups capable of reacting with isocyanates or hydroxyl groups.

8. The stretchable film according to claim 1, wherein the surface gloss of the stretchable film at 60 degrees is not greater than 0.3 GU.

9. A surface coating composition, said surface coating composition comprising: Adhesive precursor, said adhesive precursor comprising an urethane resin composition; The urethane resin beads, wherein the amount of the urethane resin beads is calculated based on 100 parts by weight of the binder to be not less than 100 parts by weight and not more than 240 parts by weight, and the urethane resin beads have an average particle size of not less than 4 µm and not more than 20 µm; and Nano-silica particles, wherein the amount of said nano-silica particles is calculated based on 100 parts by weight of the binder as not less than 20 parts by weight and not more than 120 parts by weight.

10. The surface coating composition according to claim 9, wherein the average particle size of the nano-silica particles is not less than 10 nm and not greater than 100 nm.

11. The surface coating composition according to claim 9, wherein, based on 100 parts by weight of the binder precursor, the composition comprises not less than 20 parts by weight and not more than 110 parts by weight of the nano-silica particles.

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