Laminate, surface modification member, coated product, method for manufacturing a surface modification member, and method for manufacturing a coated product

Abstract

The present invention relates to a surface modification sheet that comprises a release sheet and a surface modification layer that includes a polymer component and an oligomer component, the weight average molecular weight (Mw) of the oligomer component being 100–7000, the HSP distance (Ra) between the oligomer component and bisphenol A glycidyl ether being at least 7.5, and the surface modification layer including 0.1–30 parts by mass of the oligomer component per 100 parts by mass of the polymer component. The present invention also relates to: a laminate; a surface-modified member and a coated object that use the surface modification sheet; a production method for the surface-modified member; and a production method for the coated object.

Description

[Technical Field]

[0001] The present invention relates to a surface-modified sheet, a laminate, a surface-modified member, a coated product, a method for manufacturing a surface-modified member, and a method for manufacturing a coated product. [Background technology]

[0002] In recent years, lightweight and impact-resistant resins have been used in components for transportation equipment such as railway vehicles, aircraft, ships, and automobiles, as well as electronic equipment and housing equipment. Various materials are bonded to the surface of these resin components. Furthermore, various functional coatings are formed on the resin components.

[0003] When joining resin components to metal or other resins, sufficient adhesion is necessary. Conventionally, rubber epoxy-based curable resin compositions are known as such adhesives. However, resin components do not readily adhere to adhesives, and sufficient adhesive strength cannot be obtained using conventional adhesives or adhesive sheets. Furthermore, high-strength resin components such as carbon fiber reinforced polymers (CFRP) require a high level of adhesive strength. Therefore, bonding resin components requires the application of a primer solution, or, prior to the application of the primer solution, various surface treatments such as sandblasting, corona treatment, and plasma treatment as pretreatment. For example, one technique for obtaining sufficient adhesive strength involves applying an appropriate primer solution to modify the surface of a thermoplastic resin component. However, this technique has the problem that it cannot achieve sufficient adhesive strength with highly solvent-resistant resins (e.g., PPS, PA, PP, etc.). Furthermore, such surface treatment methods require both a surface treatment step and a drying step, increasing the number of steps and reducing productivity, thus posing a cost problem.

[0004] Furthermore, one method for applying an easy-adhesion treatment to resin components to provide sufficient adhesive strength is the use of a surface-modified sheet. For example, Patent Document 1 describes a surface-modifying sheet that can impart sufficient adhesive strength to a thermoplastic resin.

[0005] Furthermore, technologies for manufacturing a surface-modified member having a smooth surface using a surface-modifying sheet (Patent Document 2) and technologies for suppressing wrinkles of a surface-modified member using a low linear expansion release sheet (Patent Document 3) have also been studied.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the conventional technology, when the resin member constituting the surface-modified member contains a reinforcing material such as carbon fiber or glass fiber, for example, although the adhesion between the resin member and the coating film is improved by using the surface-modifying sheet, a new problem has been found that the appearance may change over time in a high-temperature and high-humidity environment.

[0008] In view of the above problems, an object of the present invention is to provide a surface-modifying sheet that has excellent adhesive strength, can prevent the occurrence of unevenness and form a smooth surface-modified layer with a uniform thickness, can suppress changes in appearance even in a high-temperature and high-humidity environment, and enables integral molding of the surface-modified layer and the resin member when forming the surface-modified member. Another object is to provide a laminate, a surface-modified member, a coated object, a method for manufacturing a surface-modified member, and a method for manufacturing a coated object using this surface-modifying sheet.

Means for Solving the Problems

[0009] The inventors diligently conducted research to solve the aforementioned problems. As a result, they discovered that by forming the surface modification layer into a sheet and adding an oligomer component to the surface modification layer that has low compatibility with the resin contained in the resin member and has a specific molecular weight range, it is possible to form a smooth surface modification layer with excellent adhesive strength, prevents unevenness, suppresses changes in appearance even in high temperature and high humidity environments, and enables integral molding of the surface modification layer and the resin member during the formation of the surface modification member, thus completing the present invention.

[0010] The means to solve the aforementioned problem are as follows: [1] It comprises a release sheet and a surface modification layer, The surface modification layer comprises a polymer component and an oligomer component. The weight-average molecular weight (Mw) of the aforementioned oligomer component is 100 to 7000. A surface-modified sheet in which the HSP distance (Ra) between the oligomer component and the bisphenol A type glycidyl ether is 7.5 or greater, and the oligomer component is present in an amount of 0.1 to 30 parts by mass per 100 parts by mass of the polymer component. [2] The surface-modified sheet according to [1], wherein the polymer component comprises non-polar units and polar units. [3] The surface-modified sheet according to [1] or [2], wherein the average thickness of the surface-modified layer is 0.1 to 50 μm. [4] A laminate in which the surface modification layer of a surface modification sheet described in any one of items (1) to (3) is laminated on at least a portion of the surface of a resin material containing a thermosetting epoxy resin. [5] The laminate according to [4], wherein the resin material is a prepreg. [6] A surface-modified member in which the surface-modified layer of a surface-modified sheet described in any one of items (1) to (3) is laminated on at least a portion of the surface of a resin member containing a thermosetting epoxy resin. [7] A painted product having a coating on at least a portion of the surface-modifying member described in [6]. [8] The coated article according to [7], wherein the coating film is at least one selected from paint, printing, vapor deposition, and plating. [9] A method for manufacturing a surface-modified member using a surface-modified sheet described in any one of items [1] to [3], comprising a lamination step of laminating the surface-modified layer onto a resin member containing a thermosetting epoxy resin by heating and pressing.

[10] A method for manufacturing a painted product using a surface-modified sheet as described in any one of items (1) to (3), comprising the steps of: manufacturing a surface-modified member by laminating the surface-modified layer onto a resin member containing a thermosetting epoxy resin by heating and pressing; and forming a coating film on the surface-modified layer side of the surface-modified member. [Effects of the Invention]

[0011] The surface-modified sheet according to the embodiment of the present invention exhibits excellent adhesive strength, prevents unevenness, and can form a smooth surface-modified layer with a uniform thickness. It also suppresses changes in appearance even in high-temperature and high-humidity environments, and allows for integral molding of the surface-modified layer and the resin member during the formation of the surface-modified member. [Brief explanation of the drawing]

[0012] [Figure 1] Figure 1 is a schematic cross-sectional view showing an example of a surface-modified sheet according to an embodiment of the present invention. [Figure 2] Figure 2 is a schematic cross-sectional view showing an example of a surface modification member according to an embodiment of the present invention. [Figure 3] Figure 3 is a schematic cross-sectional view showing a configuration in which a surface-modified sheet according to an embodiment of the present invention is placed on a resin material. [Figure 4] Figure 4 is a schematic cross-sectional view showing an example of a painted product according to an embodiment of the present invention. [Modes for carrying out the invention]

[0013] Embodiments of the present invention will be described in detail below.

[0014] [Surface modification sheet] An embodiment of the present invention comprises a release sheet and a surface modification layer. The surface modification layer comprises a polymer component and an oligomer component. The weight-average molecular weight (Mw) of the aforementioned oligomer component is 100 to 7000. The HSP distance (Ra) between the oligomer component and the bisphenol A type glycidyl ether is 7.5 or greater. The surface-modified sheet contains 0.1 to 30 parts by mass of the oligomer component per 100 parts by mass of the polymer component.

[0015] For example, as shown in Figure 1, the surface modification sheet 200 comprises a release sheet 20 and a surface modification layer 10.

[0016] In the embodiment of the present invention, the surface-modified sheet has a sheet-like surface-modified layer, so instead of coating the surface of the resin member, it can be integrally molded by loading it onto the resin material and heat-treating it. Therefore, it prevents unevenness caused by repulsion and other issues, and allows for the formation of a surface-modified layer with a uniform thickness on the surface of the resin member. Furthermore, when providing the surface-modified layer to only a portion of the surface of the resin member, it is possible to suppress a decrease in yield due to overflow and other issues.

[0017] When the resin component constituting the surface modification member includes reinforcing materials such as carbon fibers or glass fibers, its appearance may change over time in high-temperature and high-humidity environments. The inventors of this invention surmise the cause as follows: When manufacturing the surface-modified member, specifically when a surface-modified sheet is placed on a resin material and heat-treated, unreacted resin (uncured resin in thermosetting resins) contained in the resin material migrates to the surface-modified layer. When the surface-modified member is exposed to a high-temperature, high-humidity environment in this state, the unreacted resin acts as a plasticizer in the surface-modified layer, causing the surface-modified layer to become less elastic. As a result, it is thought that the reinforcing material migrates to the surface-modified layer, causing a change in appearance.

[0018] In the surface-modified sheet according to an embodiment of the present invention, the surface-modified layer contains an oligomer component having a molecular weight within a specific range. Because the oligomer component has a low molecular weight and high mobility, it is believed that at least a portion of it segregates (bleeds out) onto the surface-modified layer side of the surface-modified sheet during or after the formation of the surface-modified layer. When a surface-modified member is manufactured using a surface-modified sheet with the oligomer component segregated on its surface, the oligomer component has low compatibility with the resin in the resin material, thus suppressing the migration of unreacted resin in the resin material to the surface-modified layer. As the oligomer component functions as a blocking layer in this way, the surface-modified layer is less likely to become less elastic even when exposed to high temperature and high humidity environments, preventing the reinforcing material in the resin member from migrating to the surface-modified layer and suppressing deformation of the surface-modified layer. As a result, it is presumed that a good appearance can be maintained and the adhesion of the coating film will also be good. In the above explanation, the term "block layer" is used for convenience, but for the oligomer component to function as a block layer, that is, to suppress the migration of unreacted resin in the resin material to the surface modification layer, it is sufficient for at least a portion of it to be segregated on the surface of the surface modification sheet facing the surface modification layer; it is not necessarily required to form a layer.

[0019] <Surface modification layer> (Oligomer component) The weight-average molecular weight (Mw) of the oligomer component contained in the surface-modified sheet according to the embodiment of the present invention is 100 to 7000. If the weight-average molecular weight is less than 100, the mobility of the oligomer component becomes too high, resulting in insufficient function as a blocking layer during the manufacturing of surface-modified materials (the function of suppressing the migration of unreacted resin in the resin material to the surface-modified layer), which easily leads to changes in appearance. Also, if it exceeds 7000, the oligomer component does not easily segregate on the surface of the surface-modified layer during or after its formation, so in this case as well, the function as a blocking layer is insufficient. From the viewpoint of suppressing changes in appearance, the weight-average molecular weight of the oligomer component is preferably 200 or more, more preferably 300 or more, and even more preferably 500 or more. Furthermore, from the viewpoint of facilitating segregation of the oligomer component on the surface-modified layer, it is preferably 6500 or less, more preferably 6000 or less, and even more preferably 5500 or less.

[0020] In this invention, the weight-average molecular weight (Mw) of the oligomer component is a polymethyl methacrylate equivalent value obtained from a calibration curve prepared using standard polystyrene with gel permeation chromatography (GPC). Details of the measurement will be described later in the examples.

[0021] The HSP distance (Ra) between the oligomer component and bisphenol A type glycidyl ether is 7.5 or greater. As described later, the surface-modified sheet according to the embodiment of the present invention can be suitably used in the manufacture of a surface-modified member using a resin member containing a thermosetting epoxy resin. The above HSP distance (Ra) is an indicator of the compatibility between the oligomer component and the thermosetting epoxy resin contained in the resin member (which may also be a resin material), and a larger value indicates lower compatibility. By setting the above HSP distance (Ra) to 7.5 or higher, and reducing the compatibility between the oligomer component and the thermosetting epoxy resin contained in the resin material, the oligomer component functions as a blocking layer, and the migration of unreacted epoxy resin in the resin material to the surface modification layer during the manufacturing of the surface modification material can be suppressed. From the viewpoint of suppressing changes in appearance, the HSP distance (Ra) is preferably 7.8 or higher, more preferably 8.0 or higher, and even more preferably 8.5 or higher. Furthermore, the larger the HSP distance (Ra), the lower the compatibility between the oligomer component and the thermosetting epoxy resin contained in the resin member. Therefore, although there is no particular upper limit, it is preferably 45 or lower.

[0022] In this invention, the HSP distance (Ra) between the oligomer component and bisphenol A type glycidyl ether is used as an indicator of compatibility between the oligomer component and the thermosetting epoxy resin contained in the resin member. However, bisphenol A type glycidyl ether is merely a compound used as an indicator, and it may or may not be contained in the resin member. In other words, the thermosetting epoxy resin contained in the resin member may be bisphenol A type glycidyl ether, or it may be any other thermosetting epoxy resin.

[0023] The Hansen solubility parameter (hereinafter referred to as HSP value) and HSP distance are explained below. Hansen solubility parameters are based on the Hildebrand solubility parameters and the dispersion force (δ D ), permanent dipole intermolecular force (δ P ), hydrogen bonding force (δ H The three components of the HSP (Heat Point Spectrum) are divided and plotted in three-dimensional space to form a vector. Substances with similar vectors can be judged to have high solubility. In other words, the similarity of solubility can be determined from the distance between their HSP values ​​(HSP distance). The definition and calculation of the Hansen solubility parameter are described in Charles M. Hansen's "Hansen Solubility Parameters: A Users Handbook" (CRC Press, 2007).

[0024] HSP values ​​are known for various resins and solvents, and these can be used as they are, or values ​​calculated using the computer software HSPiP (Hansen Solubility Parameters in Practice) can be used. HSPiP also includes a database of resins and solvents. In this specification, the HSP values of the oligomer component and bisphenol A glycidyl ether are calculated using HSPiP by the following procedure using the Hansen sphere method. A prediction method using a neural network method called Y-MB implemented in HSPiP was used. At this time, the molecular structure is input as the linear notation Smiles formula of the molecule, and δ D , δ P , δ H are calculated and three-dimensionally plotted, and a Hansen sphere is obtained from these coordinates. The center coordinates of this Hansen sphere are the HSP values of the resin to be evaluated.

[0025] The HSP distance (Ra) between the oligomer component (HSP values: δ D1 , δ P1 , δ H1 ) and bisphenol A glycidyl ether (HSP values: δ D2 , δ P2 , δ H2 ) can be calculated by Equation (1). Ra = {4×(δ D1 - δ D2 ) 2 + (δ P1 - δ P2 ) 2 + (δ H1 - δ H2 ) 2} 1 / 2 (1) (In Equation (1), δ D1 is the dispersion force of the oligomer component, δ P1 is the permanent dipole intermolecular force of the oligomer component, δ H1 is the hydrogen bonding force of the oligomer component, δ D2 is the dispersion force of bisphenol A glycidyl ether, δ P2 is the permanent dipole intermolecular force of bisphenol A glycidyl ether, and δ H2 represents the hydrogen bonding force of bisphenol A glycidyl ether, respectively.)

[0026] The oligomer components that can be used are not particularly limited as long as the weight-average molecular weight and the HSP distance (Ra) with bisphenol A type glycidyl ether are within the above range, but examples include acrylic oligomers, styrene oligomers, xylene oligomers, rosin ester oligomers, rosin oligomers, terpene oligomers, terpene phenol oligomers, petroleum oligomers, amine oligomers, amide oligomers, epoxy oligomers, and the like.

[0027] It is preferable that the acrylic oligomer is a non-functional oligomer that does not have any functional groups.

[0028] Commercially available oligomers may be used as the oligomer component. Examples of commercially available acrylic oligomers include "UP-1000" and "UP-1080" (manufactured by Toagosei Co., Ltd., ARUFON® registered trademark). Examples of commercially available styrene oligomers include "UP-1150" (manufactured by Toagosei Co., Ltd., ARUFON® registered trademark). Examples of commercially available xylene-based oligomers include "Nikanol H-80" (manufactured by Fudo Co., Ltd., Nikanol® registered trademark). Examples of commercially available rosin ester oligomers include "Pensel D-125" (manufactured by Arakawa Chemical Industries, Ltd., registered trademark).

[0029] In the surface modification layer, the oligomer component is contained in an amount of 0.1 to 30 parts by mass per 100 parts by mass of the polymer component, as described later. If the amount is less than 0.1 parts by mass, the effect of suppressing appearance changes due to the addition of the oligomer component is difficult to obtain. If it exceeds 30 parts by mass, the fluidity of the surface modification layer increases, making it more susceptible to deformation, and thus more prone to appearance changes. From the viewpoint of suppressing changes in appearance, the oligomer component is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, and even more preferably 0.5 parts by mass or more, per 100 parts by mass of the polymer component. Furthermore, from the viewpoint of suppressing excessive bleeding of the oligomer component and obtaining sufficient function as a block layer, it is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and even more preferably 20 parts by mass or less.

[0030] The surface modification layer may contain only one oligomer component or two or more. If two or more oligomer components are included, the weight-average molecular weight of the main oligomer component, the HSP distance (Ra) with bisphenol A type glycidyl ether, and the amount added should be within the above range. The main component, oligomer, refers to a component that makes up 50% or more by mass of the total amount of oligomer components contained in the surface modification layer.

[0031] (Polymer component) The surface modification layer (which may be the material of the surface modification layer) contains a polymer component, and it is preferable that the polymer component has non-polar units and polar units. The polar units have polar groups. The content of the polymer component in the polar unit surface modification layer is preferably 50% to 99.9% by mass, more preferably 70% to 99.9% by mass, even more preferably 90% to 99.9% by mass, particularly preferably 92% to 99.9% by mass, and most preferably 95% to 99.9% by mass.

[0032] In this invention, the polymer component refers to a component with a weight-average molecular weight greater than 7000. In this invention, the weight-average molecular weight (Mw) of the polymer can be measured using the GPC method, in the same manner as the weight-average molecular weight measurement of the oligomer.

[0033] Examples of nonpolar units in the polymer component include polyethylene units, polypropylene units, and polystyrene units. There may be only one type of nonpolar unit, or there may be two or more types.

[0034] Examples of polar groups in a polymer component include epoxy groups, carboxyl groups, nitrile groups, amide groups, ester groups, hydroxyl groups, acid anhydrides, and silanol groups. Examples of polar units having such polar groups include glycidyl methacrylate units, vinyl acetate units, acrylonitrile units, amide units, (meth)acrylic acid ester units, hydroxyethyl (meth)acrylate units, and maleic anhydride units. There may be only one polar unit or two or more polar units.

[0035] The polymer components that the surface modification layer (which may also be the material of the surface modification layer) may contain may be at least one selected from methoxymethyl group-containing polymers, hydroxyl group-containing polymers, carboxyl group-containing polymers, amino group-containing polymers, and amide group-containing polymers.

[0036] Such polymer components that may be included in the surface modification layer (which may also be the material of the surface modification layer) are preferably addition curing agents, and more preferably addition curing agents that react with epoxy groups.

[0037] As the methoxymethyl group-containing polymer, any suitable polymer containing a methoxymethyl group (-CH2-OCH3) can be used, as long as it does not impair the effects of the present invention. Examples of such methoxymethyl group-containing polymers include methoxymethyl group-containing polyamide resins. Commercially available polymers containing methoxymethyl groups may be used. Examples of such commercially available products include the "Fine Resin" (registered trademark) series (manufactured by Namari Co., Ltd.). The methoxymethyl group-containing polymer may be one type or two or more types.

[0038] The methoxymethyl group-containing polymer is preferably such that its weight-average molecular weight (Mw) is more than 7,000 and 1,000,000 or less, more preferably more than 7,000 and 500,000 or less, even more preferably more than 7,000 and 100,000 or less, particularly preferably more than 7,000 to 70,000, and most preferably between 10,000 and 50,000, in order to better exhibit the effects of the present invention.

[0039] As the hydroxyl group-containing polymer, any suitable polymer containing a hydroxyl group (-OH) can be used, as long as it does not impair the effects of the present invention. Examples of such hydroxyl group-containing polymers include hydroxyl group-containing acrylic polymers. Commercially available polymers containing hydroxyl groups may be used. Examples of such commercially available products include the "ARUFON® UH-2000 series" (manufactured by Toagosei Co., Ltd.). The hydroxyl group-containing polymer may be one type or two or more types.

[0040] The hydroxyl group-containing polymer is preferably such that its weight-average molecular weight (Mw) is more than 7,000 and 1,000,000 or less, more preferably more than 7,000 and 500,000 or less, even more preferably more than 7,000 and 100,000 or less, particularly preferably more than 7,000 and 70,000 or less, and most preferably more than 7,000 and 50,000 or less, in order to better exhibit the effects of the present invention.

[0041] As the carboxyl group-containing polymer, any suitable polymer containing a carboxyl group (-COOH) can be used, as long as it does not impair the effects of the present invention. Examples of such carboxyl group-containing polymers include carboxyl group-containing acrylic polymers. Commercially available polymers containing carboxyl groups may be used. Examples of such commercially available products include the "ARUFON® UC-3000 series" (manufactured by Toagosei Co., Ltd.). The carboxyl group-containing polymer may be one type or two or more types.

[0042] The carboxyl group-containing polymer is preferably such that its weight-average molecular weight (Mw) is more than 7,000 and 1,000,000 or less, more preferably more than 7,000 and 500,000 or less, even more preferably more than 7,000 and 100,000 or less, particularly preferably more than 7,000 and 70,000 or less, and most preferably more than 7,000 and 50,000 or less, in order to better exhibit the effects of the present invention.

[0043] As the amino group-containing polymer, any suitable polymer containing an amino group (-NH2) can be used, as long as it does not impair the effects of the present invention. Commercially available polymers containing amino groups may be used. The amino group-containing polymer may be one type or two or more types. The surface modification layer (which may also be the material of the surface modification layer) may contain at least one selected from a tertiary amine-containing compound and a strong acid.

[0044] Such tertiary amine-containing compounds or strong acids that may be included in the surface modification layer (which may also be the material of the surface modification layer) are preferably catalytic curing agents, and more preferably catalytic curing agents that react with epoxy groups.

[0045] As the tertiary amine-containing compound, any suitable compound containing a tertiary amine can be used, as long as it does not impair the effects of the present invention. Examples of such tertiary amine-containing compounds include imidazole derivatives and polyethyleneimines. Commercially available products may be used as tertiary amine-containing compounds. Examples of such commercial products include the "Curesol" series (imidazole-based epoxy resin curing agent, manufactured by Shikoku Chemicals Co., Ltd.) as an imidazole derivative, and the "Epomin" (registered trademark) series (manufactured by Nippon Shokubai Co., Ltd.) as a polyethyleneimine. The tertiary amine-containing compound may be one type or two or more types.

[0046] As the strong acid, any suitable strong acid can be used, as long as it does not impair the effects of the present invention. Examples of such strong acids include trifluoroborane, ionic liquids, and Nafion. Examples of ionic liquids include BF3-C2H5NH2 and HMI-PF6. A commercially available strong acid can be used. The strong acid may be one type or two or more types.

[0047] As the amide group-containing polymer, any suitable polymer containing an amide group (-CO-NH2) can be used, as long as it does not impair the effects of the present invention. Examples of such amide group-containing polymers include polyamide copolymer resins. Commercially available polymers containing amide groups may be used. Examples of such commercially available products include "Amiran CM8000" (manufactured by Toray Industries, Inc.). The amide group-containing polymer may be one type or two or more types.

[0048] The amide group-containing polymer is preferably such that its weight-average molecular weight (Mw) is more than 7,000 and 1,000,000 or less, more preferably more than 7,000 and 500,000 or less, even more preferably more than 7,000 and 200,000 or less, particularly preferably 10,000 to 100,000, and most preferably 20,000 to 70,000, in order to better exhibit the effects of the present invention.

[0049] (Other additives) The surface modification layer (which may be the material of the surface modification layer) may further contain a crosslinking agent as an additive. The crosslinking agent may be included in the surface modification layer in the form after the crosslinking reaction, the form before the crosslinking reaction, the partially crosslinked form, or in intermediate or complex forms thereafter. Because the surface modification layer contains a crosslinking agent, the polymer forms a three-dimensional network structure, which increases the elasticity of the surface modification layer and makes it easier to suppress changes in appearance even in high-temperature and high-humidity environments.

[0050] Examples of crosslinking agents include isocyanate-based crosslinking agents, epoxy-based crosslinking agents, amine-based crosslinking agents, thiol-based crosslinking agents, unsaturated crosslinking agents, oxazoline-based crosslinking agents, aziridine-based crosslinking agents, carbodiimide-based crosslinking agents, metal chelate-based crosslinking agents, and peroxide-based crosslinking agents, with epoxy-based crosslinking agents and peroxide-based crosslinking agents being preferred.

[0051] The crosslinking agent that may be included in the surface modification layer may be one type or two or more types.

[0052] From the viewpoint of increasing elasticity, the amount of crosslinking agent that can be included in the surface modification layer is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of polymer. Furthermore, from the viewpoint of imparting high surface tension, it is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less. The type, combination, and content of crosslinking agents that may be included in the surface modification layer can be appropriately determined according to the purpose and desired properties. For example, if the crosslinking agent is a peroxide-based crosslinking agent, it is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and even more preferably 0.1 parts by mass or more, per 100 parts by mass of polymer. Furthermore, from the viewpoint of imparting high surface tension, it is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and even more preferably 1 part by mass or less.

[0053] The surface modification layer (which may be the material of the surface modification layer) may further contain fine particles as an additive. Because the surface modification layer contains fine particles, a high modulus of elasticity can be imparted, making it easier to suppress changes in appearance even in high-temperature and high-humidity environments. The fine particles may be inorganic or organic.

[0054] Examples of inorganic nanoparticles include silicon dioxide nanoparticles (e.g., fumed silica, colloidal silica, precipitated silica, silica gel, silica aerogel, quartz glass, glass fiber, etc.), titanium dioxide nanoparticles, aluminum oxide nanoparticles, zinc oxide nanoparticles, tin oxide nanoparticles, calcium carbonate nanoparticles, barium sulfate nanoparticles, talc nanoparticles, kaolin nanoparticles, and calcium sulfate nanoparticles. Examples of organic fine particles include polymethyl methacrylate resin powder (PMMA fine particles), silicone resin powder, polystyrene resin powder, polycarbonate resin powder, acrylic styrene resin powder, benzoguanamine resin powder, melamine resin powder, polyolefin resin powder, polyester resin powder, polyamide resin powder, polyimide resin powder, polyfluoroethylene resin powder, carbon fiber, and cellulose fiber. The above-mentioned fine particles may be used after surface treatment as needed. From the viewpoint of heat resistance, the fine particles are preferably inorganic fine particles, and from the viewpoint of dispersion stability of the coating solution, silicon dioxide fine particles are more preferable.

[0055] The surface modification layer may contain only one type of fine particle, or two or more types.

[0056] From the viewpoint of increasing elasticity, the content of fine particles that may be included in the surface modification layer is preferably 0.1 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 5 parts by mass or more, per 100 parts by mass of polymer. Furthermore, from the viewpoint of film-forming properties, it is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and even more preferably 30 parts by mass or less. The types, combinations, and content of fine particles that may be included in the surface modification layer can be appropriately determined according to the purpose and desired properties. The average thickness of the surface modification layer is preferably 0.1 to 50 μm.

[0057] In a method for separating polymer components and oligomer components contained in a mixed state in a surface-modified layer and confirming the molecular weight of each component, examples of methods for separating polymer components and oligomer components include solid-phase extraction, liquid chromatography extraction, and solvent extraction. By applying the GPC method to each component separated by the above separation method, the molecular weight of each component can be confirmed. If compositional information is needed to identify each component, 1 H-NMR and 13 It can be identified by combining analytical methods such as nuclear magnetic resonance (C-NMR), infrared spectroscopy (IR), gas chromatography-mass spectroscopy (GC-MS), and matrix-assisted laser desorption / ionization time-of-flight mass spectrometry (MALDI-TOFMS).

[0058] The thickness of the surface modification layer is not particularly limited, ranging from 0.01 μm to 2000 μm, more preferably from 0.1 to 1000 μm, even more preferably from 0.1 to 50 μm, and most preferably from 1 to 30 μm. The thickness of the surface modification layer can be measured by first measuring the thickness of the surface modification sheet using a dial thickness gauge (e.g., Peacock GC-9), then measuring the thickness of the release sheet after removing the surface modification layer at that location, and finally determining the difference as the thickness of the surface modification layer. The average thickness of the surface modification layer is the average value of measurements taken at 10 points.

[0059] <Release sheet> The release sheet is not particularly limited, but it is preferably heat resistant to 100°C or higher, and preferably has a tensile modulus of elasticity of 1 GPa or less at 100°C. It may be a silicone resin sheet or a non-silicone resin sheet, but a non-silicone resin sheet is preferred. Examples include fluorine-based resin sheet film (Nitoflon, manufactured by Nitto Denko Corporation), polyester resin sheet, polymethylpentene-based resin sheet (Opulan®, manufactured by Mitsui Chemicals Tohcello), polystyrene-based resin sheet (Oidis®, manufactured by Kurabo), polyamide-based resin sheet, and polyolefin-based resin sheet.

[0060] More specifically, examples of release sheets that can be used for surface modification sheets include unstretched polyamide 6, unstretched polyamide 66, biaxially oriented polyamide 6, biaxially oriented polyamide 66, biaxially oriented polypropylene, biaxially oriented polyethylene terephthalate, biaxially oriented polybutylene terephthalate, easily moldable polyethylene terephthalate, cast polytetrafluoroethylene, unstretched extruded tetrafluoroethylene-ethylene copolymer (ETFE), unstretched extruded tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFA), unstretched extruded tetrafluoroethylene-hexafluoropropylene copolymer (FEP), and laminates with these as the main layers.

[0061] From the viewpoint of shape conformability, the thickness of the release sheet is preferably 1 μm to 1000 μm, more preferably 10 μm to 500 μm, even more preferably 10 μm to 300 μm, and particularly preferably 10 μm to 100 μm. Furthermore, if necessary, the surface of the release sheet facing the surface modification layer, or both sides thereof, may be treated with a suitable release agent such as silicone.

[0062] [Manufacturing of surface-modified sheets] Surface-modified sheets can be manufactured by any suitable method. Examples include dipping a release sheet into a solution containing the surface-modified layer material and solvent (surface-modified composition) and drying as necessary; brushing the surface of the release sheet with the solution containing the surface-modified layer material and solvent and drying as necessary; applying the surface of the release sheet with the solution containing the surface-modified layer material and solvent using various coaters and drying as necessary; and spraying the surface of the release sheet with the solution containing the surface-modified layer material and solvent and drying as necessary.

[0063] Examples of surface modification compositions include solutions in which the material for the surface modification layer is dissolved in a solvent. Examples of solvents include water; alcohols such as methanol, ethanol, and isopropyl alcohol (IPA); ketones such as methyl ethyl ketone; esters; aliphatic, alicyclic, and aromatic hydrocarbons; halogenated hydrocarbons; amides such as dimethylformamide; sulfoxides such as dimethyl sulfoxide; and ethers such as dimethyl ether and tetrahydrofuran. To suppress the formation of gels, ethanol or a mixed solvent of ethanol, isopropyl alcohol, and water is preferred. The solvent may be one type or two or more types.

[0064] The solid content concentration in the surface modification composition can be set appropriately depending on the purpose. From the viewpoint of thickness accuracy of the surface modification layer, the mass percentage is preferably 1% to 40% by mass, more preferably 10% to 35% by mass, and even more preferably 15% to 30% by mass.

[0065] The surface modification composition may optionally contain various additives such as pH adjusters, crosslinking agents, viscosity modifiers (thickeners, etc.), leveling agents, release modifiers, plasticizers, softeners, fillers, colorants (pigments, dyes, etc.), surfactants, antistatic agents, preservatives, anti-aging agents, UV absorbers, antioxidants, and light stabilizers. For example, by adding a coloring agent, the surface modification layer becomes visible, making it easier to determine whether the surface of the resin component has already been modified, which offers advantages in terms of process control. Examples of colorants include dyes or pigments. Alternatively, the colorant may be a fluorescent material that is visible under a black light.

[0066] [Laminate] The laminate according to an embodiment of the present invention is a laminate in which the surface modification layer of the surface modification sheet is laminated on at least a portion of the surface of a resin material containing a thermosetting epoxy resin. The laminate, which is a resin material with a surface modification layer in an embodiment of the present invention, can be manufactured by laminating the surface modification layer side of a surface modification sheet onto at least a portion of the surface of the resin material before molding.

[0067] The thermosetting epoxy resin included in the resin material is not particularly limited. As described above, the HSP distance (Ra) between the oligomer component and bisphenol A type glycidyl ether is used as an indicator of compatibility between the oligomer component in the surface modification layer and the thermosetting epoxy resin contained in the resin member. However, bisphenol A type glycidyl ether is merely a compound used as an indicator and may or may not be present in the resin material. Examples of thermosetting epoxy resins include bisphenol A type glycidyl ether, bisphenol F type glycidyl ether, bisphenol AD ​​type epoxy resin, naphthalene type epoxy resin, biphenyl type epoxy resin, glycidylamine type epoxy resin, alicyclic epoxy resin, dicyclopentadiene type epoxy resin, polyether type epoxy resin, and silicone-modified epoxy resin.

[0068] The resin material may be a prepreg. Here, prepreg refers to a material made by impregnating reinforcing materials such as carbon fiber or glass fiber with a resin mixed with additives such as a hardening agent, and then heating or drying it to a semi-cured state.

[0069] In other words, the resin material may contain fiber-reinforced resin, and the thermosetting epoxy resin may be a fiber-reinforced thermosetting epoxy resin. Examples of fiber-reinforced thermosetting epoxy resins include carbon fiber-reinforced thermosetting epoxy resins and glass fiber-reinforced thermosetting epoxy resins.

[0070] Examples of resin material shapes include flat plates, curved plates, sheets, and films. The thickness of the resin material is, for example, 0.001 mm to 10 mm.

[0071] "At least a portion of the surface of the resin material" means at least a portion of all the surfaces that the resin material has. For example, if the resin material is in the form of a plate, sheet, or film, it means a portion of at least one of its surfaces, or all of at least one of its surfaces.

[0072] The above explanation can be directly applied to the surface modification sheet and surface modification layer.

[0073] [Surface modification material] In an embodiment of the present invention, the surface modification member is characterized in that the surface modification layer of the surface modification sheet is laminated on at least a portion of the surface of a resin member containing a thermosetting epoxy resin. In the embodiment of the present invention, a surface-modified member is obtained by molding a resin material with a surface-modified layer, as shown in Figure 2, in which a surface-modified layer 10 is provided on the surface of a resin member 100. Preferably, a mixed layer, which is a mixture of the resin member and the surface-modified layer, is provided between the resin member and the surface-modified layer.

[0074] The above description can be directly applied to the surface modification sheet, surface modification layer, and resin material. The resin member is obtained by molding the resin material, and the preferred shape and thickness of the resin member are the same as those of the resin material.

[0075] "At least a portion of the surface of the resin component" means at least a portion of all the surfaces of the resin component. For example, if the resin component is in the form of a plate, sheet, or film, it means a portion of at least one of its surfaces, or all of at least one of its surfaces.

[0076] The mixed layer is a layer formed by mixing a resin member and a surface modification layer. For example, by applying a surface modification layer to at least a portion of the surface of a resin material and performing heat molding, the interface between the surface modification layer and the resin member melts and comes into contact, resulting in welding and mixing or chemical bonding, and the mixed layer is obtained as a result. The formation of the mixed layer improves the adhesive strength between the resin member and the surface modification layer. In the mixed layer, it is preferable that the resin contained in the resin member and the polymer components constituting the surface modification layer are bonded by a chemical reaction such as covalent bonding. Through a chemical reaction such as covalent bonding, the interface between the resin member and the surface modification layer disappears, and the resin member and the surface modification layer become integrated, resulting in superior adhesive strength.

[0077] However, since the surface modification member according to the embodiment of the present invention uses a surface modification sheet containing an oligomer component with low compatibility with the thermosetting epoxy resin, excessive mixing between the resin member and the surface modification layer is suppressed.

[0078] The thickness of the mixed layer can be appropriately determined depending on the heat molding conditions and the type of resin component and surface modification layer. From the viewpoint of improving adhesive strength, the thickness of the mixed layer is preferably 1.5 nm or more, and more preferably 2.0 nm or more. However, due to the low compatibility between the resin component and the surface modification layer, the upper limit is approximately 10 μm.

[0079] Heat molding may be performed simultaneously with the lamination of the resin material and the surface modification sheet, or it may be performed after the surface modification sheet has been laminated onto the resin material. By performing surface treatment on resin components in this manner, sufficient adhesive strength can be imparted to the resin components, enabling the production of surface-modified components with high productivity and low cost. The manufacturing method for surface-modified components can also be a method for treating the surface of resin components (a resin surface treatment method).

[0080] [Method for manufacturing surface-modified material] There are no particular limitations on the method for manufacturing the surface-modified member according to the embodiment of the present invention. For example, the surface-modified member can be manufactured by placing the surface-modified layer side of a surface-modified sheet, which is a laminate of a release sheet and a surface-modified layer, on at least a portion of the surface of a resin material containing a thermosetting epoxy resin, and then performing heat molding. Through heat molding, the polymer components contained in the surface modification layer come into molten contact with the thermosetting epoxy resin contained in the resin material, resulting in welding, mixing, or chemical bonding at the interface between the surface modification layer and the resin material, thereby forming a surface modification member. Heat molding may be performed simultaneously with the placement of the surface modification sheet, or after the placement of the surface modification sheet. By performing surface treatment on the resin component in this manner, sufficient adhesive strength can be imparted to the resin component, and the surface-modified component can be manufactured with high productivity and low cost. Furthermore, by using the surface-modified sheet according to the embodiment of the present invention, unreacted thermosetting epoxy resin contained in the resin material is less likely to migrate to the surface-modified layer during the heat molding process, thus suppressing changes in appearance even when exposed to high temperature and high humidity environments. A method for manufacturing a surface-modified member may also be a method for treating the surface of a resin member (a method for surface treatment of a resin member).

[0081] The above description can be directly applied to the resin components, resin materials, surface modification sheets, release sheets, and surface modification layers.

[0082] In the manufacture of surface-modified members, when the curing temperature of the thermosetting epoxy resin contained in the resin member is T2°C, it is preferable to provide a surface-modified layer on at least a portion of the surface of the resin material containing the thermosetting epoxy resin and perform heat molding at a temperature of T1°C or higher. The curing temperature is defined as a temperature within the exothermic temperature range of the heat flow curve measured by DSC for the uncured thermosetting epoxy resin. The heat molding temperature is preferably T1°C to T3°C, more preferably (T1+10)°C to (T3-10)°C, and even more preferably (T1+20)°C to (T3-20)°C. Here, T1 is the temperature at which heat generation begins (°C) when measuring uncured thermosetting epoxy resin using DSC, and T3 is the temperature at which heat generation ends (°C).

[0083] By performing surface treatment on the resin member using the method described above, with the heat molding temperature within the above range, the interface between the surface-modified layer and the resin member can melt and come into contact, resulting in welding and mixing or chemical bonding, thereby providing the resin member with sufficient adhesive strength. Furthermore, this can be achieved with high productivity and low cost.

[0084] After melting or softening at least a portion of the surface of the resin member, a surface modification layer can also be applied to the molten or softened surface of the resin member. By applying a surface modification layer to the surface of the molten or softened resin member, the heat from the surface of the resin member causes the surface modification layer to weld, mix, or chemically bond, thereby providing the resin member with sufficient adhesive strength.

[0085] "Molten state" refers to a state in which at least a portion of the surface of the resin member is melted, and this can preferably be achieved by heating the resin member to a temperature above its melting point.

[0086] "Softened state" refers to a state in which at least a portion of the surface of the resin member is softened, which can preferably be achieved by heating the resin member to a temperature above its softening temperature.

[0087] A "chemical bond" can be formed when the resin component and the material of the surface modification layer chemically form a covalent bond.

[0088] Examples of heat molding methods include oven heating, infrared heating, high-frequency heating, and heat pressing. It is preferable to perform the molding by resin molding, and more preferably by heat pressing (press molding). The heating and molding time is preferably 1 second to 10 minutes.

[0089] A method for manufacturing a surface-modified member according to an embodiment of the present invention is a method for manufacturing a surface-modified member using a surface-modified sheet, which may include a lamination step of laminating the surface-modified layer onto a resin member containing a thermosetting epoxy resin by heating and pressing.

[0090] As an example of a heated press, the surface modification layer side of a surface modification sheet is placed on at least a portion of the surface of a resin component (which may be made of resin material) within a molding machine (for example, a press machine), and a molding process involving heating (for example, integral molding by heated press) is performed. With this method, surface treatment of the resin component and molding of the resin component can be performed simultaneously, thus providing high productivity and low cost.

[0091] The molding pressure during press molding is preferably 1 MPa or more, more preferably 2 MPa or more, and even more preferably 3 MPa or more, from the viewpoint of deforming the molded product with the die. Furthermore, from the viewpoint of maintaining the amount of resin in the molded product, it is preferably 30 MPa or less, more preferably 20 MPa or less, and even more preferably 10 MPa or less.

[0092] Furthermore, by peeling the release sheet off the surface-modified member, a surface-modified member having a surface-modified layer on its surface can be obtained. The method of peeling off the release sheet is not particularly limited and can be done by hand, using dedicated peeling equipment, etc.

[0093] The surface modification layer side of the surface modification sheet, which is a laminate of a release sheet and a surface modification layer, is placed on at least a portion of the surface of a resin member (which may be a resin material), and after heat molding, the release sheet is preferably removed. For example, as shown in Figure 3, the surface modification sheet 200 may be placed on the surface of the resin material 400 such that the surface modification layer 10 side of the surface modification sheet 200 faces the surface of the resin material 400. After that, the laminate can be heat-molded and the release sheet can be removed. By removing the release sheet in this way, the surface modification layer is transferred to the surface of the resin member, and a surface modification member (sometimes referred to as a laminated member of the resin member and the surface modification layer) is obtained. As mentioned above, preferably, a mixed layer is provided between the resin member and the surface modification layer, which is a mixture of the resin member and the surface modification layer.

[0094] As shown in Figure 2, the above manufacturing method provides a surface modification layer 10 on the surface of the resin member 100, thereby obtaining a surface modification member. In Figure 2, the surface modification layer 10 is laminated on the surface of the resin member 100, but preferably, a mixed layer (not shown) is provided between the resin member 100 and the surface modification layer 10, which is a mixture of the resin member and the surface modification layer.

[0095] [Painted products and methods for manufacturing painted products] In the embodiment of the present invention, the coated product has a coating film on at least a portion of the surface-modified member, and it is preferable that the coating film is on at least a portion of the surface of the surface-modified member on the surface-modified layer side. The coating film may be at least one selected from paint, printing layer, vapor deposition layer, and plating layer. As an example of a coated product according to an embodiment of the present invention, Figure 4 shows a coated product 300 in which a surface-modified member is provided with a surface-modified layer 10 on the surface of a resin member 100, and a coating film 30 is provided on the surface on the side of the surface-modified layer.

[0096] Since the surface modification layer is formed using a sheet-like surface modification sheet rather than being applied to the surface of the component, unevenness due to repelling and other issues can be prevented. As a result, the surface modification layer can be formed with a uniform thickness on the surface of the resin component, and the coating film can be applied with a uniform film thickness. Furthermore, by applying a surface modification layer to the surface of a molten or softened resin component, the heat from the surface of the resin component causes the surface modification layer to weld, mix, or chemically bond, increasing the adhesive strength between the surface modification layer and the resin component, thus forming a coating with excellent adhesion. Moreover, since integral molding of the surface modification layer and the resin component is possible during the formation of the coated object, there is no need for cleaning or polishing processes using organic solvents to remove the mold release agent before forming the coating, resulting in superior safety and reduced environmental and labor burdens. Furthermore, by using the surface modification sheet according to the embodiment of the present invention, the resulting coated product is less prone to changes in appearance even when exposed to high temperature and high humidity environments.

[0097] The coating film is not particularly limited and can be any of the following: epoxy, polyester-melamine, alkyd-melamine, acrylic-melamine, acrylic-urethane, or acrylic-polyacid hardener. The thickness of the coating film is not particularly limited, but is 0.01 to 2000 μm, more preferably 0.1 to 1000 μm, even more preferably 0.5 to 500 μm, and especially preferably 1 to 200 μm.

[0098] A method for manufacturing a coated product according to an embodiment of the present invention is a method for manufacturing a coated product using a surface-modified sheet according to an embodiment of the present invention, and includes the steps of: manufacturing a surface-modified member by laminating a surface-modified layer onto a resin member containing a thermosetting epoxy resin by heating and pressing; and forming a coating film on the surface-modified layer side of the surface-modified member.

[0099] There are no particular restrictions on the method of coating the paint film; common methods such as brush application, roller application, spray application, and various coater applications can be used, and the amount applied is not particularly limited. Furthermore, the heating time and temperature of the paint film can be appropriately determined depending on the paint used, the amount applied, etc.

[0100] The above descriptions can be directly applied to the resin component, surface modification sheet, surface modification layer, and surface modification component. Furthermore, the above description in the [Method for Manufacturing Surface Modification Components] can be directly applied to the process for manufacturing the surface modification component.

[0101] [Process control method] In the manufacture of surface-modified sheets, surface-modified members, and coated products according to the embodiments of the present invention, for example, by including additives such as dyes, pigments, or crystalline substances in the surface-modified composition or surface-modified layer, the surface-modified layer becomes visible, making it easier to control the manufacturing process.

[0102] The above description can be applied directly to the surface modification composition, surface modification sheet, coated product, and additive.

[0103] Process control methods include, for example, visually inspecting the surface-treated and colored areas, or recognizing and identifying them using images captured by a camera. [Examples]

[0104] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way to these examples.

[0105] <Weight molecular weight (Mw) of oligomeric components> The weight-average molecular weight (Mw) of the oligomer component was determined using gel permeation chromatography (GPC) and converted to polymethyl methacrylate values ​​from a calibration curve created using standard polystyrene.

[0106] (Measurement conditions for weight-average molecular weight (Mw)) Device name: HLC-8420GPC, manufactured by Tosoh Corporation Test specimen concentration: 1 mg / mL Test specimen injection volume: 20 μl Eluent: HFIP + 10mM-CF3COONa Flow rate: 0.300ml / min Measurement (column) temperature: 40℃ Columns: Specimen columns; TSKgel SuperAWM-H (2 tubes), Reference column; TSKgel SuperH-RC (1 tube), manufactured by Tosoh Corporation. Detector: Differential refractometer (RI)

[0107] <HSP distance (Ra) between oligomeric component and bisphenol A glycidyl ether> The estimation method used was a neural network method called Y-MB, implemented in the HSP value calculation software (HSPiP Ver.4.1.0.7 (Hansen Solubility Parameters in Practice)). In this case, the molecular structure was input using the Smiles equation, a linear notation for molecules, and the HSP value (δ) of the oligomer component was used. D1 , δ P1 , δ H1 ) and the HSP value (δ) of bisphenol A type glycidyl ether D2 , δ P2 , δ H2 We calculated each of the following: The HSP distance (Ra) was calculated using equation (1). Ra = {4 × (δ D1 -δ D2 ) 2 +( δ P1 -δ P2 ) 2 +( δ H1 -δ H2 ) 2} 1 / 2 (1) (In formula (1), δ D1 This is the dispersion power of the oligomer component, δ P1 This is the permanent dipole intermolecular force of the oligomer component, δ H1 This is the hydrogen bonding force of the oligomer component, δ D2 This is the dispersion power of bisphenol A type glycidyl ether, δ P2 This is the permanent dipole intermolecular force of bisphenol A type glycidyl ether, δ H2 (These represent the hydrogen bonding forces of bisphenol A type glycidyl ether.)

[0108] <Thickness of the surface modification layer> The thickness of the surface modification layer was measured using a dial gauge (Peacock GC-9). The thickness of the surface modification sheet was measured, and the thickness (μm) of the release sheet with the surface modification layer removed at that point was measured. The difference between these two measurements was taken as the thickness of the surface modification layer (μm). The average thickness (μm) is the average of 10 measurements.

[0109] <Coating thickness> The coating thickness was measured using a dial gauge (Peacock GC-9). The thickness of the painted object and the surface-modified material before coating was measured, and the difference was defined as the coating thickness (μm). The average thickness (μm) is the average value of 10 measurements.

[0110] <60° gloss> The gloss level at room temperature (25°C) was measured using specular gloss measurement (JIS Z8741-1997). A BYK micro-tri-gloss gloss meter was placed on the painted surface to measure the gloss level of the coating. The average gloss level is the average of five measurements. The 60° gloss was measured after being kept for 24 hours in a constant temperature and humidity chamber set to a temperature of 85°C and humidity of 85%RH. Using the 60° gloss at room temperature (25°C) and the 60° gloss after being held for 24 hours in an environment of 85°C and 85% RH, the rate of decrease in 60° gloss was calculated using the following formula. Gloss reduction rate (%) = [(Gloss (25°C) - Gloss (85°C / 85%RH)) / Gloss (25°C)] × 100 When the gloss reduction rate at 60° was 3% or less, it was determined that the change in the appearance of the coating film had been suppressed.

[0111] <Paint adhesion> The painted samples prepared in the examples and comparative examples were evaluated using the cross-cut method described in JIS K5600-5-6, and the number of peeled-off paint layers was counted. When the number of peeled-off paint layers was 0 out of 100, the adhesion was judged to be good. • Cutting interval: 2mm • Number of cross-cuts: 100 squares • Release tape: Nichiban Cellophane Tape (registered trademark) 24mm width

[0112] [Example 1] (Surface modification sheet (1)) 100 parts by mass of polyamide copolymer resin (Amiran CM8000, manufactured by Toray Industries, Inc.) and 0.1 parts by mass of acrylic oligomer (ARUFON UP-1000, manufactured by Toagosei Co., Ltd.) were dissolved in a mixed solvent of ethanol (EtOH) / water / isopropyl alcohol (IPA) = 68% by mass / 12% by mass / 20% by mass at 40°C to prepare a 20% by mass solids solution (surface modification composition). The prepared surface modification composition was filtered through a nylon mesh with a mesh size of 188 μm, then coated onto a release sheet (Niftron 900UL: manufactured by Nitto Denko Corporation) fluororesin sheet film (polytetrafluoroethylene (PTFE) (thickness 0.05 mm, dimensions: width 250 mm x length 450 mm)) using an applicator, and dried in a constant temperature dryer at 100°C for 2 minutes to produce a surface modification sheet (1) with a surface modification layer of 10 μm thickness.

[0113] (Surface modification member (1)) The surface-modified sheet (1) prepared as described above was placed on top of a carbon fiber-reinforced thermosetting epoxy resin prepreg (bisphenol A type glycidyl ether type, manufactured by Toray Industries, Inc., Torayca, FK6244C-84K) (dimensions: width 150 mm x length 120 mm x thickness 1 mm), and the surface-modified member (1) was fabricated by heat welding using a press process (molding pressure 3 MPa, 150°C, 5 minutes).

[0114] (Painted item (1)) After peeling off the release sheet from the surface-modified member (1) prepared as described above, V-Top H (two-component curing urethane paint) manufactured by Dainippon Paint Co., Ltd. was applied to the surface-modified layer with an applicator, and the coating was cured at room temperature for more than 3 days to produce a coated object (1) with a coating thickness of 50 μm.

[0115] [Examples 2-7] Except for changing the materials and amounts used in the surface modification composition as shown in Table 1, surface modification sheets (2) to (7), surface modification members (2) to (7), and coated products (2) to (7) were prepared in the same manner as in Example 1.

[0116] [Example 8] Except for changing the thickness of the surface modification layer to 30 μm, the surface modification sheet (8), surface modification member (8), and coated product (8) were prepared in the same manner as in Example 2.

[0117] [Comparative Examples 1-11] Except for changing the materials and amounts used in the surface modification composition as shown in Table 2, surface modification sheets (r1) to (r11), surface modification members (r1) to (r11), and coated products (r1) to (r11) were prepared in the same manner as in Example 1.

[0118] [Comparative Example 12] A coated object (r12) was prepared in the same manner as in Example 1, except that a surface modification layer was not provided and a surface modification member was prepared using a release sheet.

[0119] Examples and comparative examples are shown in Tables 1 and 2 below.

[0120] [Table 1]

[0121] [Table 2]

[0122] The materials listed in Tables 1 and 2 are as follows: ·polymer CM8000: Polyamide copolymer resin (Amiran, manufactured by Toray Industries, Inc.) FR105: Methoxymethyl group-containing nylon 6 (Fine resin manufactured by Namari Co., Ltd.) • Oligomer UP-1000: Acrylic oligomer (ARUFON, manufactured by Toagosei Co., Ltd.) UP-1080: Acrylic oligomer (ARUFON, manufactured by Toagosei Co., Ltd.) UP-1150: Styrene oligomer (ARUFON, manufactured by Toagosei Co., Ltd.) Nikanol H: Xylene-based oligomer (manufactured by Fudo Co., Ltd., Nikanol H-80) Pencel D-125: Rosin ester oligomer (manufactured by Arakawa Chemical Industries, Ltd., Pencel) Haritac PCJ: Rosin ester oligomer (Haritac, manufactured by Harima Chemicals Group Co., Ltd.) UC-3510: Acrylic oligomer (ARUFON, manufactured by Toagosei Co., Ltd.) Pencel D160: Rosin ester oligomer (manufactured by Arakawa Chemical Industries, Ltd., Pencel) MHDR: Rosin ester oligomer (manufactured by Nissei Forestry Chemical Co., Ltd.) UC-3000: Acrylic oligomer (ARUFON, manufactured by Toagosei Co., Ltd.) YS Polystar UH1150: Terpene phenol oligomer (manufactured by Yasuhara Chemical Co., Ltd., YS Polystar) [Industrial applicability]

[0123] The surface-modified sheet according to the embodiment of the present invention exhibits excellent adhesive strength, prevents unevenness, and can form a smooth surface-modified layer with a uniform thickness. It also suppresses changes in appearance even in high-temperature and high-humidity environments, and allows for integral molding of the surface-modified layer and the resin member during the formation of the surface-modified member.

[0124] Although the present invention has been described in detail and with reference to specific embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention. This application is based on Japanese Patent Application No. 2021-051500 filed on March 25, 2021, the contents of which are incorporated herein by reference. [Explanation of Symbols]

[0125] 10 Surface Modified Layer 20 release sheets 30 Coating film 100 Resin component 200 Surface Modification Sheets 300 Painted items 400 Resin materials

Claims

1. The surface modification sheet comprises a release sheet and a surface modification layer, and the surface modification layer is laminated on at least a portion of the surface of a resin material containing a thermosetting epoxy resin. The surface modification layer comprises a polymer component and an oligomer component. The weight-average molecular weight (Mw) of the oligomer component is 100 to 7000. The HSP distance (Ra) between the oligomer component and the bisphenol A type glycidyl ether is 7.5 or greater, and the oligomer component is present in an amount of 0.1 to 30 parts by mass per 100 parts by mass of the polymer component. The aforementioned polymer component is a methoxymethyl group-containing polymer or an amide group-containing polymer. A laminate in which the aforementioned resin material is a prepreg.

2. The laminate according to claim 1, wherein the polymer component has non-polar units and polar units.

3. The laminate according to claim 1 or 2, wherein the average thickness of the surface modification layer is 0.1 to 50 μm.

4. A surface-modifying member formed from a laminate according to any one of claims 1 to 3.

5. A coated article having a coating film on at least a portion of the surface modifying member according to claim 4.

6. The coated article according to claim 5, wherein the coating film is at least one selected from paint, printing, vapor deposition, and plating.

7. A method for manufacturing a surface-modified member using a laminate according to any one of claims 1 to 3, comprising a lamination step of laminating the surface-modified layer onto the prepreg by heating and pressing.

8. A method for manufacturing a coated product using a laminate according to any one of claims 1 to 3, comprising the steps of: manufacturing a surface-modified member by laminating the surface-modified layer onto the prepreg by heating and pressing; and forming a coating film on the surface-modified layer side of the surface-modified member.

Images