Release film and film laminate

Abstract

A release film for protecting an adhesive layer, which has a release layer on one side of a base film (B), the surface roughness (arithmetic average height; Sa) of the surface of the aforementioned release layer is 200 nm or more, the maximum peak height (Sp) is 300 nm or more, and a distribution curve representing the relationship between the protrusion height (X) and the number of protrusions (Y) of the surface of the release layer satisfies the following formula (1). -(logY2-logY1) / (X2-X1) ≥ 1.0 (1) (In the aforementioned formula, Y1 and Y2 respectively represent the number of protrusions (pieces / mm 2 ) of the surface of the release layer at a protrusion height of X1=0.98 μm and X2=1.98 μm of the surface of the release layer, respectively) can be provided: a release film with an adhesive layer that eliminates moisture or bubble residue as much as possible when adhered to an adherend by water sealing, and that is easily cut into individual sheets, and a film laminate.

Description

Technical Field

[0001] This invention relates to release films and film laminates. Background Technology

[0002] In the past, polyester film, especially polyethylene terephthalate film and polyethylene naphthalate film, has excellent mechanical properties, heat resistance and chemical resistance, and has been used for various purposes such as packaging, electronic components, electrical insulation, metal lamination, optical applications, touch panels, anti-reflection, and glass scattering prevention.

[0003] The polyester films used in these wide-ranging applications can be used as adhesive layers for the protection of glass, steel plates, and other materials primarily used outdoors, such as those in buildings, automobiles, trams, and airplanes.

[0004] When a substrate film with an adhesive layer is bonded to an object such as glass or a car body, air or moisture may remain at the interface between the adhesive layer and the object after bonding. This can result in poor appearance due to air bubbles of a size of several hundred micrometers that can be visually confirmed, or sometimes reduced adhesion due to moisture residue.

[0005] Therefore, as a countermeasure, there are several methods, such as pre-spraying an aqueous solution containing water or surfactant onto the adhesive layer surface, or performing drainage or degassing treatment with a scraper, known as "water sealing," to suppress the aforementioned adverse conditions.

[0006] In this case, for the purpose of forming micro-grooves on the adhesive surface to allow fluid to flow out at the adhesive interface, a release liner with a micro-embossed pattern consisting of multiple interconnected linear protrusions on one surface was proposed (Patent Document 1). Furthermore, as an adhesive sheet that can easily remove air accumulation that may occur during the bonding of the adhered objects, possessing excellent degassing properties and good adhesion, an adhesive sheet was proposed that has a resin layer on a substrate or release agent, the surface of the resin layer opposite to the substrate or release agent has adhesive properties, and that surface has amorphous recesses (Patent Document 2). Furthermore, an automotive coating protective film was proposed, which has a pressure-sensitive re-peelable adhesive layer on the vehicle body surface side and a plastic film on the outer side, such that the average surface roughness (Ra) of the centerline is 0.1–100 μm (Patent Document 3).

[0007] Existing technical documents

[0008] Patent documents

[0009] Patent Document 1: Japanese Patent Application Publication No. 2006-70273

[0010] Patent Document 2: WO2015 / 152352

[0011] Patent Document 3: Japanese Patent Application Publication No. 7-89468 Summary of the Invention

[0012] The problem the invention aims to solve

[0013] Regarding the aforementioned "water seal" method, the process of draining or degassing using a scraper requires skilled techniques. In recent years, with the expansion of the market for PPF (paint protection film) applications—such as polishing printed adhesive films on automobiles, trucks, trams, and airplanes, or for protecting automotive coatings—for example, applications involving 1m... 2 When large-area adhesive films are applied to the objects being adhered to, achieving uniform adhesion becomes increasingly difficult.

[0014] Furthermore, the technologies disclosed in the aforementioned patent documents 1 to 3 are insufficient in terms of moisture or foam residue.

[0015] The present invention was made in view of the above-mentioned actual situation, and its solution is to novelly provide: a release film for adhesive layer protection that is easy to cut even when applied to an adhesive object, with the moisture or bubble residue being minimized; and a film laminate having the same.

[0016] Solution for solving the problem

[0017] In view of the above-mentioned actual situation, the inventors conducted in-depth research and found that the above-mentioned problems can be easily solved by using a release film containing a specific structure, thus completing the present invention.

[0018] That is, the present invention provides the following [1] to

[23] .

[0019] [1] A release film for adhesive layer protection has a release layer on one side of a substrate film (B), wherein the surface roughness (arithmetic mean height; Sa) of the release layer surface is 200 nm or more, the maximum peak height (Sp) is 300 nm or more, and the distribution curve representing the relationship between the protrusion height (X) and the number of protrusions (Y) on the release layer surface satisfies the following formula (1).

[0020] -(logY2-logY1) / (X2-X1)≥1.0 (1)

[0021] (In the above formula, Y1 and Y2 represent the number of protrusions on the surface of the release layer with protrusion heights of X1 = 0.98 μm and X2 = 1.98 μm, respectively (number / mm) 2 ). )

[0022] [2] According to the release film for adhesive layer protection described in [1] above, wherein the aforementioned substrate film (B) contains 0.1 to 10% by mass of particles with an average particle size of 1 to 10 μm.

[0023] [3] According to the release film for adhesive layer protection described in [1] above, wherein the aforementioned substrate film (B) has a multilayer structure, and the surface layer of the substrate film (B) on the side in contact with the release layer contains 0.1 to 10% by mass of particles with an average particle size of 1 to 10 μm.

[0024] [4] The release film for adhesive layer protection according to any one of [1] to [3] above, wherein the number of protrusions with a protrusion height of 0.98 μm shown in X1 above is 1000 per mm. 2 above.

[0025] [5] The release film for adhesive layer protection according to any one of [1] to [4] above, wherein the number of protrusions with a height of 1.98 μm or more as shown in X2 above is 3 per mm. 2 above.

[0026] [6] The release film for adhesive layer protection according to any one of [1] to [5] above, wherein the aforementioned release layer contains a curable silicone resin.

[0027] [7] The release film for adhesive layer protection according to [6] above, wherein the aforementioned release layer further contains a surfactant.

[0028] [8] The release film for adhesive layer protection according to any one of [1] to [7] above, wherein the aforementioned substrate film (B) is a polyester film.

[0029] [9] According to the adhesive layer protective release film described above [8], wherein the birefringence of the aforementioned polyester film (Δn×10) 3 () is below 25.

[0030]

[10] The release film for adhesive layer protection according to [8] or [9] above, wherein the MOR value of the aforementioned polyester film is 1.5 or less.

[0031]

[11] The release film for adhesive layer protection according to any one of [1] to

[10] above has a degassing index of 2000 seconds or less.

[0032]

[12] The release film for adhesive layer protection according to any one of [8] to

[11] above, wherein the aforementioned polyester film contains 50% by mass or more of recycled raw materials.

[0033]

[13] A film laminate having a substrate film (A) on the release layer of the release film described in any one of [1] to

[12] , separated by an adhesive layer.

[0034]

[14] According to the film laminate described in

[13] above, wherein the aforementioned substrate film (A) is a polyurethane film.

[0035]

[15] According to the film laminate described in

[13] above, wherein the aforementioned substrate film (A) is a resin film with a printing layer.

[0036]

[16] The film laminate according to any one of

[13] to

[15] above, wherein the aforementioned adhesive layer is any one of an acrylic adhesive layer, a urethane adhesive layer, or an organosilicon adhesive layer.

[0037]

[17] The film laminate according to any one of

[13] to

[16] above, wherein the surface roughness (arithmetic mean height; Sa) of the aforementioned adhesive layer surface after the release film is peeled off is 200 nm or more.

[0038]

[18] The film laminate according to any one of

[13] to

[17] above, wherein the elastic modulus of the aforementioned adhesive layer at 25°C is 20 MPa or more.

[0039]

[19] A method for manufacturing a release film for adhesive layer protection according to any one of [1] to

[12] above, wherein the substrate film (B) is a multilayer film having a polyester layer containing particles only on the surface, the polyester layer in contact with the release layer containing particles with an average particle size of 1.0 to 4.5 μm, the amount of the particles being added being 1 to 10% by mass, and the difference between the longitudinal stretch ratio and the transverse stretch ratio being within 0.2 times.

[0040]

[20] In the method for manufacturing a release film for adhesive layer protection as described in

[19] above, the longitudinal stretching ratio is 3.0 to 4.5 times and the transverse stretching ratio is 3.5 to 5.0 times.

[0041]

[21] The film laminate according to any one of

[13] to

[18] above, at least one of which is a sheet with a thickness of 1000 mm or more.

[0042]

[22] The release film for adhesive layer protection according to any one of [1] to

[12] above is for use as a protective film for automotive coating or for use as a polishing film.

[0043]

[23] The film laminate according to any one of

[13] to

[18] and

[21] above is for use as a protective or polishing film for automotive coating.

[0044] The effects of the invention

[0045] According to the present invention, a release film and film laminate with an adhesive layer can be provided that, when bonded to an object by a water seal, minimizes moisture or bubble residue, yet is still easily cut into single sheets, and has high industrial value. It is particularly suitable for use as a film for automotive coating or polishing. Attached Figure Description

[0046] Figure 1 This is a top view of the release layer surface (“release surface”) of the release film (sample film) obtained in Example 1.

[0047] Figure 2 This is a top view of the release layer surface (“release surface”) of the release film (sample film) obtained in Example 2.

[0048] Figure 3 This is a top view of the release layer surface (“release surface”) of the release film (sample film) obtained in Example 3.

[0049] Figure 4 This is a top view of the release layer surface (“release surface”) of the release film (sample film) obtained in Comparative Example 1.

[0050] Figure 5 A top view of the adhesive layer surface after the release film (sample film) obtained in Example 1 is bonded to the adhesive layer surface and then peeled off.

[0051] Figure 6 A top view of the adhesive layer surface after the release film (sample film) obtained in Example 2 is bonded to the adhesive layer surface and then peeled off.

[0052] Figure 7 A top view of the adhesive layer surface after the release film (sample film) obtained in Example 3 is bonded to and peeled off.

[0053] Figure 8 A top view of the adhesive layer surface after it has been peeled off, showing the release film (sample film) obtained in Comparative Example 1 adhering to the adhesive layer surface. Detailed Implementation

[0054] The release film for adhesive layer protection of the present invention (hereinafter, sometimes simply referred to as "release film") has a release layer on one side of the substrate film (B). Hereinafter, each feature will be described in detail.

[0055] [Substrate Film (B)]

[0056] Example resin film as substrate film (B).

[0057] Examples include resin films formed from polymers such as polyethylene, polypropylene, cyclic olefin polymers (COP), polyester, polystyrene, acrylic resins, polycarbonate, polyurethane, cellulose triacetate (TAC), polyvinyl chloride, polyethersulfone, polyamide, polyimide, and polyamide-imide. Furthermore, any material capable of being film-formed can be used, including blends of these materials (polymer blends) and composites of structural units (polymers).

[0058] Among the films described above, polyester films exhibit excellent heat resistance, planarity, optical properties, and strength, making them particularly preferred. The polyester film can be a single layer or a multilayer structure; besides two or three layers, it can also be four or more layers, as long as it does not conform to the spirit of the invention, and there are no particular limitations. A multilayer structure of two or more layers is preferred, giving each layer distinctive characteristics and achieving multifunctionality.

[0059] The polyester used in polyester film is preferably obtained by polycondensation of an aromatic dicarboxylic acid and an aliphatic diol. Examples of aromatic dicarboxylic acids include terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid, while examples of aliphatic diols include ethylene glycol, diethylene glycol, trimethylene glycol, tetramethylene glycol, neopentyl glycol, and 1,4-cyclohexanediol.

[0060] Representative polyesters include polyethylene terephthalate (PET), polyethylene-2,6-naphthalenedicarboxylate (PEN), and polybutylene terephthalate. These polyesters can be uncopolymerized homopolymers, or copolymers containing less than 20 mol% of dicarboxylic acid as the main component and / or less than 20 mol% of diol as the main component. Mixtures of these are also possible.

[0061] Polyesters can be obtained by conventionally known methods, such as directly obtaining low-polymerization-degree polyesters from the reaction of dicarboxylic acids and diols, or by reacting lower alkyl esters of dicarboxylic acids with diols in the presence of conventionally known transesterification catalysts, followed by polymerization in the presence of a polymerization catalyst. As polymerization catalysts, known catalysts such as antimony compounds, germanium compounds, and titanium compounds can be used; however, it is preferable to use catalysts with an antimony compound content of zero or less (based on antimony levels of 100 ppm or less) to further reduce film darkening.

[0062] Furthermore, when a titanium compound is used as a catalyst, the amount of metal remaining in the film is small, which is preferable from the viewpoint of film transparency and reduction of foreign matter generation.

[0063] In the substrate film (B), it is preferable to further mix the particles such that the protrusion height (X) and the number of protrusions (Y) on the surface of the release layer satisfy the formula (1) described later, in a manner that does not impair transparency and provides the desired surface roughness (Sa) and maximum peak height (Sp) to the surface of the release layer, which will be detailed later. The type of particles used in the mixing is not particularly limited as long as they impart the aforementioned properties. Specific examples include inorganic particles such as silica, calcium carbonate, magnesium carbonate, barium carbonate, calcium sulfate, calcium phosphate, magnesium phosphate, kaolin, alumina, and titanium dioxide, as well as organic particles such as acrylic resins, styrene resins, urea resins, phenolic resins, epoxy resins, and benzoguanamine resins. Furthermore, in the polyester manufacturing process, precipitated particles obtained by precipitating and micro-dispersing a portion of a metal compound such as a catalyst can also be used. Among these, silica particles and calcium carbonate particles are particularly preferred in terms of their ability to produce effects with small quantities.

[0064] Furthermore, there are no particular restrictions on the shape of the granules used; spherical, blocky, rod-shaped, flat, etc., are all acceptable. There are also no particular restrictions on their hardness, specific gravity, color, etc. Two or more types of granules can be used in combination as needed.

[0065] In addition, in order to achieve good drainage or degassing effects, the average particle size of the particles used is preferably in the range of 1 to 10 μm, more preferably in the range of 1 to 8 μm, even more preferably in the range of 2 to 6 μm, and particularly preferably in the range of 2 to 5 μm.

[0066] Furthermore, regarding the particle content in the polyester, in the case of a single-layer film, it is preferably in the range of 0.1 to 10% by mass relative to the total polyester constituting the film. If the particle content is 0.1% by mass or more, sufficient drainage or degassing effect is obtained, and if it is 10% by mass or less, the transparency of the substrate film is ensured. From the above viewpoint, the particle content in the substrate film (B) is more preferably in the range of 1 to 10% by mass, further preferably 2 to 8% by mass, and particularly preferably 3 to 6% by mass.

[0067] Furthermore, in the case of multilayer films, it is sufficient to have particles of a predetermined content and particle size in the surface layer. For example, by forming a polyester film with a polyester layer containing particles only in the surface layer, sufficient unevenness can be formed, and the reduction in transparency due to particles can be avoided. That is, in the release film for adhesive layer protection of the present invention, for the polyester constituting the surface layer of the polyester that contacts the release layer of the polyester film, the particle content is preferably in the range of 0.1 to 10% by mass, more preferably 1 to 10% by mass, further preferably 2 to 8% by mass, and particularly preferably 3 to 6% by mass, for the sake of sufficient drainage or defoaming effect and the transparency of the substrate film. It should be noted that the average particle size is the same as that of the particles in the single-layer case described above.

[0068] There are no particular limitations on the method for adding particles to polyester, and conventionally known methods can be used. For example, particles can be added at any stage of polyester manufacturing, but it is preferable to add them during the esterification stage or after the transesterification reaction to promote the polycondensation reaction. Alternatively, it can be carried out by methods such as: using a compounding extruder with a vent to blend a slurry of particles dispersed in ethylene glycol or water with polyester raw materials; or using a compounding extruder to blend dried particles with polyester raw materials.

[0069] The birefringence (Δn×10) of the polyester film of the present invention 3 The preferred value is 25 or less. A value of 25 or less is advantageous in terms of the film's cutability. From the above perspective, the birefringence of the polyester film (Δn×10⁻⁶) is... 3 More preferably 20 or less, and even more preferably 15 or less. Birefringence (Δn×10) 3 There is no specific limit to the lower limit of ), which is usually above 0.7.

[0070] It should be noted that birefringence (Δn×10) 3 The value was determined according to the method described in the examples.

[0071] It should be noted that, in addition to the aforementioned particles, conventionally known antioxidants, heat stabilizers, lubricants, antistatic agents, fluorescent whitening agents, dyes, pigments, etc., can be added to polyester films as needed. Furthermore, depending on the purpose of protecting the film substrate from ultraviolet radiation, or preventing the coating film on the protected glass, steel plate, or other substrate from deterioration, ultraviolet absorbers, especially benzoxazinone-based ultraviolet absorbers, may also be included.

[0072] Regarding the thickness of the polyester film (substrate film (B)), from the viewpoint of using it as a release film, a range of 25 to 350 μm is preferred, more preferably 38 to 250 μm, and even more preferably 38 to 125 μm, of which a range of 38 to 100 μm is particularly preferred.

[0073] Furthermore, the polyester film can be formed into a laminated structure using various conventionally known methods such as co-extrusion. In this case, the thickness of the outermost layer, measured only on one side, is preferably 2 μm or more, more preferably 3 μm or more, and preferably less than 1 / 8 of the total thickness. By using it within the above range, a polyester film having a polyester layer containing particles only on the surface can be manufactured, as described above, resulting in sufficient unevenness and preventing a decrease in transparency due to the particles.

[0074] In the release film of the present invention, the water droplet contact angle of the surface of the polyester film on which the release layer is formed (the surface of the release layer) is preferably 70 degrees or more, more preferably 80 degrees or more, further preferably 90 degrees or more, and particularly preferably 100 degrees or more. By making the water droplet contact angle at or above the above angle, the water repellency of the release film is increased, water droplet marks and dirt are less likely to remain on the release film, and transparency is more easily maintained.

[0075] The following describes the manufacturing method of the polyester film of the present invention in detail, but any method that satisfies the spirit of the present invention is acceptable and the present invention is not particularly limited to the following examples.

[0076] Typically, polyester sheets, dried or undried according to known methods, are first fed into a melt extrusion apparatus and heated to a temperature above the melting point of each polymer, then melted. The molten polymer is then extruded from a die and rapidly cooled and solidified on a rotary cooling drum at a temperature below the glass transition temperature, resulting in an essentially amorphous, unoriented sheet. In this case, to improve the planarity of the sheet, it is preferable to improve the adhesion between the sheet and the rotary cooling drum; in this invention, electrostatic application and / or liquid coating adhesion methods are preferred.

[0077] From the viewpoint of film strength, it is preferable to stretch and thin the sheet obtained as described above along the biaxial direction. Specifically, regarding the stretching conditions, it is preferable to stretch the aforementioned unstretched sheet longitudinally at 70–145°C to a ratio of 2.0–4.5 times, forming a longitudinally uniaxially stretched film, and then stretch it transversely at 90–160°C to a ratio of 3.0–6.5 times, forming a biaxially stretched film, followed by heat treatment (heat setting) at 210–260°C for 10–600 seconds. Then, it is preferable to relax the film by 1–10% longitudinally and / or transversely in the highest temperature zone of the heat treatment and / or in the cooling zone at the heat treatment exit.

[0078] Especially for applications where it is desirable to minimize heat shrinkage, the heat treatment temperature is preferably set to 215–250°C, more preferably 220–245°C, and even more preferably 230–245°C. By setting the temperature within the above range, heat shrinkage can be minimized.

[0079] From the viewpoint of forming a sheet with a stable uneven shape, regardless of the position at which the polyester film of the present invention is collected when it is cut from a roll, the molecular orientation ratio (hereinafter referred to as "MOR value") is preferably 1.5 or less. More preferably, it is 1.3 or less, and in particular, it can be 1.1 or less.

[0080] By satisfying the aforementioned range, it is possible to collect sheet-like polyester films with uneven shapes that have good reproducibility and are independent of the sheet collection location.

[0081] It should be noted that the release film of the present invention is characterized by its large film area when applied to the substrate. Therefore, when applying an adhesive sheet with the raised and recessed surface of the release film to the substrate, there is a concern that the workability may be reduced if the degree of debubbling varies depending on the sampling location of the sheet used.

[0082] As a specific method for falling within the range of the aforementioned MOR value, for example, under film stretching conditions, the difference between the longitudinal stretching ratio and the transverse stretching ratio is within 0.2 times, preferably within 0.1 times, wherein, in particular, they can be set to the same ratio.

[0083] On the other hand, considering the productivity of rolled products, there is usually a tendency to set the transverse stretch ratio to be greater than the longitudinal stretch ratio. In this application, it is generally preferable to set the stretching conditions in the opposite direction to the direction of improving film productivity (longitudinal stretch ratio < transverse stretch ratio), and it is preferable to suppress the difference between the longitudinal stretch ratio and the transverse stretch ratio to a constant range.

[0084] For example, when taking 1m wide rolls of products from a 3m wide master roll, and cutting 1m×3m sheet-like release films from each roll, and setting the transverse stretch ratio to be greater than the longitudinal stretch ratio, it is speculated that the stretching orientation of the release films at both ends may affect the film surface protrusions. Therefore, there is a tendency for the distance between the protrusions to further increase, and the protrusion height to decrease. It is speculated that this tendency is the same throughout the entire length (longitudinal) direction of the rolls at both ends. When comparing the case of using sheet-like release films taken from rolls at both ends and bonded to adhesive sheets with the case of using sheet-like release films taken from rolls at the center, there is concern about a time difference in the debubbling of the resulting adhesive sheets.

[0085] This invention proposes a strategy to address the aforementioned concerns, and proposes a release film that can achieve a stable defoaming effect regardless of the collection location of the sheet-like release film.

[0086] Furthermore, the objects to which the adhesive sheet with the release film is bonded are assumed to be automobiles, railway tracks, trams, airplanes, etc., emphasizing large-area applications. Therefore, regarding the size of the release film, at least one piece is preferably 1000 mm or more, more preferably two pieces are both 1000 mm or more, and particularly preferably both pieces are 1000 mm or more and have an area of ​​1 m². 2 Under the above conditions, the reproducibility of the concave-convex shape is good, and it achieves a stable defoaming effect.

[0087] In the polyester film of the present invention, it is preferable to contain 50% or more by mass of recycled raw materials. In particular, when the polyester film is composed of, for example, three layers, it is preferable that the middle layer contains 50% or more by mass of recycled raw materials. More preferably, it contains 70% or more by mass, and particularly 80% or more by mass. There is no particular limitation on the recycled raw materials used, as long as it does not impair the spirit of the present invention.

[0088] As a recycled material, it can be the edge material cut during film manufacturing, or it can be a recycled material formed by temporarily crushing the manufactured polyester film or polyester film with a release layer into flakes or small pieces.

[0089] In particular, the release film of the present invention is suitable for use as an adhesive layer for protection in glass, steel plates, and other road-related components mainly used outdoors, such as those used in automobiles, billboards, solar power generation, road signs, and sound barriers.

[0090] [Mold Release Layer]

[0091] The release film of the present invention has a release layer on one side of the substrate film (B). As a release layer, it not only helps protect various objects and prevents contamination of the protective film, but also improves the operability of the polyester film of the present invention. For example, when the film of the present invention is overlapped sheet by sheet, or when it is rolled into a roll, the release layer also has the following effects: preventing adhesion to the adhesive layer on the back side, improving ease of peeling or sliding, facilitating film manufacturing, improving operability, or improving the processability of the adhesive layer on the film.

[0092] The thickness of the release layer is not particularly limited as long as it is within the range that allows the invention to achieve its intended effect; preferably, it is in the range of 0.001 to 5 μm, more preferably 0.01 to 3 μm, and even more preferably 0.1 to 2 μm. By making the thickness of the release layer within the above range, good appearance, water repellency, and release properties (anti-adhesion properties with the adhesive layer) can be achieved.

[0093] <Mold Release Agent>

[0094] When forming a release layer, a release agent is required. There are no particular limitations on the release agent; conventionally known release agents can be used, such as compounds containing long-chain alkyl groups, fluorinated compounds, organosilicon compounds, waxes, etc. Among these, long-chain alkyl compounds and fluorinated compounds are preferred for their low contamination and excellent water repellency, particularly for their good release properties on the adhesive layer. These release agents can be used alone or in combination.

[0095] (Compounds containing long-chain alkyl groups)

[0096] Compounds containing long-chain alkyl groups refer to compounds having straight-chain or branched alkyl groups, typically with 6 or more carbon atoms, preferably 8 or more, and more preferably 12 or more. It should be noted that there is no particular upper limit on the number of carbon atoms; for example, 30. Examples of alkyl groups include hexyl, octyl, decyl, lauryl, octadecyl, and benzyl. Examples of compounds containing alkyl groups include various polymers containing long-chain alkyl groups, amine compounds containing long-chain alkyl groups, ether compounds containing long-chain alkyl groups, and quaternary ammonium salts containing long-chain alkyl groups. Polymers are preferred when considering heat resistance and stain resistance. Furthermore, from the viewpoint of effectively obtaining mold release properties, polymers having long-chain alkyl groups in their side chains are more preferred.

[0097] Polymer compounds with long-chain alkyl groups on their side chains can be obtained by reacting a polymer with a reactive group with a compound having an alkyl group that can react with that reactive group. Examples of such reactive groups include hydroxyl, amino, carboxyl, and acid anhydride groups. Examples of compounds containing these reactive groups include polyvinyl alcohol, polyethyleneimine, polyethyleneamine, polyacrylic acid resins containing reactive groups, and poly(meth)acrylic acid resins containing reactive groups. Among these, polyvinyl alcohol is preferred when considering mold release properties and ease of handling.

[0098] Compounds containing alkyl groups capable of reacting with the aforementioned reactive groups include, for example, isocyanates containing long-chain alkyl groups such as hexyl isocyanate, octyl isocyanate, decyl isocyanate, lauryl isocyanate, octadecyl isocyanate, and benzyl isocyanate; acyl chlorides containing long-chain alkyl groups such as hexanoyl chloride, octanoyl chloride, decanoyl chloride, lauroyl chloride, octadecanoyl chloride, and benzyl chloride; amines containing long-chain alkyl groups; and alcohols containing long-chain alkyl groups. Among these, isocyanates containing long-chain alkyl groups are preferred, and octadecyl isocyanate is particularly preferred, considering demolding properties and ease of handling.

[0099] In addition, polymers with long-chain alkyl groups in their side chains can also be obtained by copolymerizing polymers of long-chain alkyl methacrylates or copolymerizing long-chain alkyl methacrylates with other vinyl-containing monomers. Examples of long-chain alkyl methacrylates include hexyl methacrylate, octyl methacrylate, decyl methacrylate, lauryl methacrylate, octadecyl methacrylate, and benzyl methacrylate.

[0100] (Fluorine compounds)

[0101] Fluorine compounds are compounds containing fluorine atoms. In terms of coating appearance based on online coating, organic fluorine compounds are suitable, such as polymers containing perfluoroalkane compounds, polymers of olefin compounds containing fluorine atoms, and aromatic fluorine compounds such as fluorobenzene. From the viewpoint of mold release, compounds containing perfluoroalkyl groups are preferred. Compounds that also contain long-chain alkyl compounds (described later) can also be used.

[0102] Examples of compounds containing perfluoroalkyl groups include perfluoroalkyl (meth)acrylates, perfluoroalkyl (meth)acrylates, 2-perfluoroalkyl (meth)acrylates, 3-perfluoroalkyl (meth)acrylates, 3-perfluoroalkyl-1-methylpropyl (meth)acrylates, 3-perfluoroalkyl-2-propylene (meth)acrylates, and other perfluoroalkyl (meth)acrylates, their polymers; perfluoroalkyl methyl vinyl ethers, 2-perfluoroalkyl ethyl vinyl ethers, 3-perfluoropropyl vinyl ethers, 3-perfluoroalkyl-1-methylpropyl vinyl ethers, 3-perfluoroalkyl-2-propylene vinyl ethers, and other perfluoroalkyl vinyl ethers, their polymers, etc. Polymers are preferred when considering heat resistance and stain resistance. The polymer can be a single compound or a polymer of multiple compounds. Furthermore, from the viewpoint of mold release, the perfluoroalkyl group preferably has 3 to 11 carbon atoms. Polymers can also be compounds containing long-chain alkyl compounds as described later. Furthermore, from the viewpoint of adhesion to the substrate, polymers with vinyl chloride are preferred.

[0103] (organosilicon compounds)

[0104] Organosilicon compounds refer to compounds that have an organosilicon structure within their molecules. Examples include alkyl organosilicones such as dimethyl organosilicon and diethyl organosilicon, as well as phenyl organosilicones containing phenyl groups and methylphenyl organosilicones. Organosilicones with various functional groups can also be used, such as ether groups, hydroxyl groups, amino groups, epoxy groups, carboxylic acid groups, halogen groups such as fluorine, perfluoroalkyl groups, various alkyl groups, and hydrocarbon groups such as various aromatic groups. Other functional groups include organosilicones with vinyl groups and hydrogen organosilicones where hydrogen atoms are directly bonded to silicon atoms. Both can also be used together as addition-type (based on the type of addition reaction between vinyl groups and hydrosilanes) organosilicones.

[0105] In addition, modified organosilicon compounds such as acrylic-grafted organosilicon, organosilicon-grafted acrylic acid, amino-modified organosilicon, and perfluoroalkyl-modified organosilicon can also be used. If heat resistance and stain resistance are considered, curable organosilicon resins are preferred. As for the type of curing, any curing reaction type can be used, such as addition-type or active energy radiation-cured type. Curable organosilicon resins will be discussed in detail later.

[0106] <Polyether-containing organosilicon compounds>

[0107] As a preferred method for using organosilicon compounds, organosilicon compounds containing polyether groups are preferred from the viewpoints of less back-side transfer, good dispersibility in aqueous solvents, and high suitability for online coating. The polyether groups can be present in the side chains or at the ends of the organosilicon chain, or in the main chain. From the viewpoint of dispersibility in aqueous solvents, it is preferred that they be present in the side chains or at the ends.

[0108] Polyether groups can use conventionally known structures. From the viewpoint of dispersibility in aqueous solvents, aliphatic polyether groups are preferred over aromatic polyether groups, and among aliphatic polyether groups, alkyl polyether groups are preferred. Furthermore, from the viewpoint of synthesis based on steric hindrance, linear alkyl polyether groups are preferred over branched alkyl polyether groups, and among these, polyether groups formed from linear alkyl groups with 8 or fewer carbon atoms are preferred. Moreover, when the solvent is water, considering dispersibility in water, polyethylene glycol or polypropylene glycol groups are preferred, with polyethylene glycol groups being particularly suitable.

[0109] From the viewpoint of improving dispersibility in aqueous solvents and the durability of the release layer, the number of ether bonds in the polyether group is typically in the range of 1 to 30, preferably in the range of 2 to 20, and more preferably in the range of 3 to 15. If there are too few ether bonds, the dispersibility becomes poor; conversely, if there are too many, the durability and release performance become poor.

[0110] When the side chain or end of the organosilicon has a polyether group, the end of the polyether group is not particularly limited, and various functional groups such as hydroxyl, amino, mercapto, alkyl, phenyl, carboxylic acid, sulfonic acid, aldehyde, and acetal groups can be used. Among them, hydroxyl, amino, carboxylic acid, and sulfonic acid groups are preferred if water dispersibility and crosslinking properties for improving the strength of the release layer are considered, with hydroxyl groups being particularly suitable.

[0111] Regarding the content of polyether groups in polyether-containing silicones, with the siloxane bond of the silicone set to 1, the molar ratio is preferably in the range of 0.001 to 0.30, more preferably in the range of 0.01 to 0.20, further preferably in the range of 0.03 to 0.15, and particularly preferably in the range of 0.05 to 0.12. By using it within this range, the dispersibility to water and the durability of the release layer, as well as good release properties, can be maintained.

[0112] For polyether-containing silicones, a relatively low molecular weight is preferable considering dispersibility in aqueous solvents, while a high molecular weight is preferable considering the durability of the release layer and its release properties. A balance between these two characteristics is required, and the preferred number-average molecular weight is in the range of 1000 to 100000, more preferably in the range of 3000 to 30000, and even more preferably in the range of 5000 to 10000.

[0113] Furthermore, considering the changes in the release layer over time, release performance, and contamination from other processes, it is preferable to minimize the amount of low-molecular-weight components (number average molecular weight of 500 or less) in the organosilicon. As a percentage of the total organosilicon compound, this amount is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 5% by mass or less. Additionally, when using condensation-type organosilicon, the unreacted vinyl groups (vinylsilanes) and hydrogen groups (hydrosilanes) bonded to silicon remain in the release layer, contributing to changes in various properties over time. Therefore, based on the amount of functional groups in the organosilicon, the content is preferably 0.1 mol% or less, and even more preferably none.

[0114] <surfactant>

[0115] Polyether-containing silicones are difficult to coat when used alone; therefore, they are preferably used dispersed in water. For dispersion, various conventionally known surfactants can be used, such as anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. Among these, considering the dispersibility of polyether-containing silicones and their compatibility with polymers other than polyether-containing silicones that can be used in the formation of the release layer, anionic surfactants and nonionic surfactants are preferred. Alternatively, fluorinated compounds can be used instead of these surfactants.

[0116] Examples of anionic surfactants include sodium dodecylbenzenesulfonate, sodium alkyl sulfonate, sodium alkylnaphthalene sulfonate, sodium dialkyl sulfosuccinate, sodium polyoxyethylene alkyl ether sulfate, sodium polyoxyethylene alkyl allyl ether sulfate, and ammonium polyoxyethylene alkylene ether sulfate, as well as sulfate esters, carboxylates such as sodium laurylate and potassium oleate, and alkyl phosphates, polyoxyethylene alkyl ether phosphates, and polyoxyethylene alkylphenyl ether phosphates. Among these, sulfonate systems are preferred from the viewpoint of good dispersibility.

[0117] Examples of nonionic surfactants include ether-type surfactants obtained by adding ethylene oxide or propylene oxide to compounds with hydroxyl groups such as higher alcohols and alkylphenols; ester-type surfactants obtained by ester bonding of polyols such as glycerol and sugars with fatty acids; ester-ether-type surfactants obtained by adding ethylene oxide to fatty acids or fatty acid esters of polyols; and amide-type surfactants where hydrophobic and hydrophilic groups are connected by amide bonds. Among these, ether-type surfactants are preferred when considering solubility and stability in water, while those obtained by adding ethylene oxide are more preferred when considering operability.

[0118] It depends on the molecular weight and structure of the polyether-containing silicone used, and also on the type of surfactant used. Therefore, it cannot be generalized. However, as an objective, the amount of polyether-containing silicone is set to 1, preferably 0.01 to 0.5 by mass ratio, more preferably 0.05 to 0.4, and even more preferably 0.1 to 0.3.

[0119] <Cureable silicone resin>

[0120] Regarding the curable silicone resin constituting the release layer, it can be a resin with a curable silicone resin as the main component, or it can be a modified silicone based on graft polymerization with organic resins such as polyurethane resin, epoxy resin, and alkyd resin. Furthermore, when the adhesive layer is a silicone adhesive, a fluorinated silicone resin is preferred.

[0121] As for the type of curable silicone resin, any existing curing reaction type can be used, such as addition / condensation type thermosetting type, ultraviolet curing type, or electron beam curing type. Furthermore, multiple curable silicone resins can be used in combination. There are no particular restrictions on the coating form of the cured silicone resin when forming the release layer; it can be any form dissolved in an organic solvent, an aqueous emulsion, or a solvent-free form. In aqueous emulsions, surfactants are preferred.

[0122] For the surfactant, the same surfactant used in the aforementioned polyether-containing silicone compounds can be used. From the perspective of the dispersibility of the cured silicone resin, anionic surfactants and nonionic surfactants are preferred.

[0123] There are no restrictions on the type of silicone resin used in this invention. From the viewpoint of excellent release properties such as light peelability, a curable silicone resin containing an alkenyl group is preferred in this invention. An example of a curable silicone resin containing an alkenyl group is the one shown in the following general formula (1) as a diorganopolysiloxane.

[0124] R (3-a) X a SiO-(RXSiO) m -(R2SiO) n -SiX a R (3-a) ···(1)

[0125] In general formula (1), R is a monovalent hydrocarbon group with 1 to 10 carbon atoms, and X is an organic group containing an alkenyl group. a is an integer from 0 to 3, and preferably 1. m is 0 or more, but when a = 0, m is 2 or more. m and n are numbers that satisfy 100 ≤ m + n ≤ 20000. In addition, the above formula should not refer to block copolymers. R is a monovalent hydrocarbon group with 1 to 10 carbon atoms. Specifically, examples include alkyl groups such as methyl, ethyl, propyl, and butyl, cycloalkyl groups such as cyclohexyl, phenyl, and aryl groups such as tolyl. Methyl and phenyl are particularly preferred. X is preferably an organic group containing an alkenyl group and having 2 to 10 carbon atoms. Specifically, examples include vinyl, allyl, hexenyl, octenyl, acryloylpropyl, acryloylmethyl, methacryloylpropyl, cyclohexenylethyl, and vinyloxypropyl. Vinyl and hexenyl are particularly preferred. For specific examples, we can cite the following: a dimethylsiloxane-methylhexenylsiloxane copolymer with trimethylsiloxy groups at both ends of the molecular chain (96 mol% dimethylsiloxane units and 4 mol% methylhexenylsiloxane units); a dimethylvinylsiloxy-terminated dimethylsiloxane-methylhexenylsiloxane copolymer with dimethylsiloxane units at both ends of the molecular chain (97 mol% dimethylsiloxane units and 3 mol% methylhexenylsiloxane units); and a dimethylhexenylsiloxy-terminated dimethylsiloxane-methylhexenylsiloxane copolymer with dimethylhexenylsiloxane units at both ends of the molecular chain (95 mol% dimethylsiloxane units and 5 mol% methylhexenylsiloxane units).

[0126] The number average molecular weight of the cured silicone resin is preferably 50,000 or more, more preferably 80,000 or more, even more preferably 100,000 or more, and particularly preferably 150,000 or more. On the other hand, it is preferably 600,000 or less, even more preferably 550,000 or less, and particularly preferably 500,000 or less.

[0127] The release layer is preferably a layer formed by curing an organosilicon resin composition comprising the above-mentioned curable organosilicon resin and a curing agent for curing the curable organosilicon resin. Examples of curing agents include polyorganosiloxanes containing SiH groups. Polyorganosiloxanes containing SiH groups can react with curable organosilicon resins containing alkenes to form a more robust organosilicon release layer. As polyorganosiloxanes containing SiH groups, examples include organohydrogen polysiloxanes having at least two, preferably three or more, hydrogen atoms bonded to silicon atoms in one molecule, and which are linear, branched, or cyclic in form; compounds represented by the following general formula (2) are examples, but are not limited to these.

[0128] H b R 1 (3-b) SiO-(HR 1 SiO) x -(R 1 2SiO)y -SiR 1 (3-b) H b ···(2)

[0129] In general formula (2), R 1 It is a monovalent hydrocarbon group that does not contain aliphatic unsaturated bonds with 1 to 6 carbon atoms. b is an integer from 0 to 3, and x and y are integers. For specific examples, we can give examples of trimethylsiloxy-terminated methylhydrosiloxanes, trimethylsiloxy-terminated dimethylsiloxane-methylhydrosiloxane copolymers, dimethylhydrosiloxy-terminated methylhydrosiloxanes, and dimethylhydrosiloxy-terminated dimethylsiloxane-methylhydrosiloxane copolymers.

[0130] The molar ratio of Si-H groups to alkenyl groups in the organosilicon resin composition is preferably 0.1 to 2.0, more preferably 0.3 to 2.0, and even more preferably 0.3 to 1.8.

[0131] Next, specific examples of various types of commercially available silicone resins that can be used in this invention will be provided, using those manufactured by Shin-Etsu Chemical Industry Co., Ltd. as examples: KS-774, KS-775, KS-778, KS-779H, KS-847H, KS-856, X-62-2422, X-62-2461, X-62-1387, X-62-5039, X-62-5040, KNS-3051, X-62-1496, KNS320A, KNS316, X-62-1574A / B, X-62-7052, X-62-7028A / B, X-62-7619, X-62-7213, and X-41-3035, as Momentive Performance Materials. Manufactured by Inc., examples include YSR-3022, TPR-6700, TPR-6720, TPR-6721, TPR6500, TPR6501, UV9300, UV9425, XS56-A2775, XS56-A2982, UV9430, TPR6600, TPR6604, and TPR6605, as DOW CORNING TORAY. Manufacturers include SRX357, SRX211, SD7220, SD7292, LTC750A, LTC760A, LTC303E, LTC856, LTC761, SP7259, BY24-468C, SP7248S, BY24-452, DKQ3-202, DKQ3-203, DKQ3-204, DKQ3-205, and DKQ3-210 from COMPANY, LTD., and the DEHESIVE series from Wacker asahikaseisilicone Co., LTD., including DEHESIVE 636, 919, 920, 921, 924, and 929.

[0132] The release layer preferably uses a platinum-based catalyst that promotes addition-type reactions. Therefore, the above-mentioned silicone resin composition preferably also contains a platinum-based catalyst. Examples of main components include platinum-based compounds such as chloroplatinic acid, an alcoholic solution of chloroplatinic acid, a complex of chloroplatinic acid with an olefin, and a complex of chloroplatinic acid with an alkenyl siloxane, as well as platinum black, platinum-loaded silica, and platinum-loaded activated carbon. The content of the platinum-based catalyst in the release layer can be in the range of 0.01 to 10.0% by mass, preferably 0.01 to 5.0% by mass. If the content of the platinum-based catalyst in the release layer is 0.01% by mass or more, sufficient peel force is obtained, and adverse conditions such as insufficient advancement of the curing reaction and deterioration of the surface texture are not produced.

[0133] On the other hand, if the content of platinum-based catalyst in the release layer is less than 3.0% by mass, it is cost-effective. In addition, it improves reactivity and does not cause process defects such as the generation of gel foreign matter.

[0134] Furthermore, addition reactions are highly reactive; therefore, ethynyl alcohol can be added as an addition reaction inhibitor, depending on the circumstances. This component is an organic compound having a carbon-carbon triple bond and a hydroxyl group, preferably a compound selected from the group consisting of 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and phenylbutynyl alcohol.

[0135] To adjust the peelability of the release layer, various peel control agents can be used. In cases of increasing peel strength, organopolysiloxane resins, silica particles, and silicone substances that increase peel strength are typically added to the release layer in appropriate amounts to obtain the desired peel strength. Examples of commercially available peel control agents include Shin-Etsu Chemical Industry Co., Ltd.'s KS-3800 and X-92-183, and DOW CORNING TORAY COMPANY, LTD.'s SDY7292, BY24-843, and BY24-4980.

[0136] To achieve a light peeling force, various low-molecular-weight siloxanes are selected, and their content in the release layer is appropriately adjusted to allow the migrating components of the siloxanes to exert their release properties. Examples of low-molecular-weight siloxane compounds include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, and decamethylcyclopentasiloxane. Other compounds that are low-molecular-weight cyclic siloxanes include: trimethylsiloxy-terminated dimethylsiloxane oligomers; dimethylhydroxysiloxy-terminated dimethylsiloxane oligomers; and the aforementioned compounds can also be mixed as needed. These low-molecular-weight siloxane compounds, as migrating components, are typically present in the silicone resin at 0.1–15.0% by mass, preferably 0.1–10.0% by mass, and more preferably 0.1–5% by mass, thereby achieving the desired light peeling. If the content is 0.1% by mass or more, the migrating components are sufficient, and sufficient release properties are achieved. On the other hand, if the content of low molecular weight siloxanes is less than 15.0% by mass, there will be no excessive precipitation of migratory components and no problem of process contamination.

[0137] In addition, in order to ensure good adhesion between the release layer and the coating of the polyester film, it is preferable to use an organosilicon compound represented by the following general formula (3).

[0138] Si(X) d (Y) e (R 1 ) f ···(3)

[0139] In the above formula, X is an organic group having at least one selected from epoxy, mercapto, (meth)acryloyl, alkenyl, haloalkyl, and amino groups, and R 1 For a monovalent hydrocarbon group with 1 to 10 carbon atoms, Y is a hydrolyzable group, d is an integer of 1 or 2, e is an integer of 2 or 3, f is an integer of 0 or 1, and the expression is d + e + f = 4.

[0140] The organosilicon compounds represented by the aforementioned general formula (3) can be those with two hydrolytic groups Y (D unit source) that can form siloxane bonds through hydrolysis / condensation reactions or those with three groups (T unit source).

[0141] In general formula (3), the monovalent hydrocarbon group R 1 The carbon number is 1 to 10, therefore, methyl, ethyl, and propyl are particularly preferred.

[0142] In general formula (3), the hydrolyzable group Y can be exemplified by the following: methoxy, ethoxy, butoxy, isopropoxy, acetoxy, butyryloxy, and amino groups. These hydrolyzable groups can be used alone or in combination. If methoxy or ethoxy is used, it can impart good storage stability to the coating material, and in addition, it has appropriate hydrolytic properties, so it is particularly preferred.

[0143] Specific examples of organosilicon compounds contained in the release layer include vinyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-methacryloyloxypropyltrimethoxysilane, γ-acryloyloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, 5-hexenyltrimethoxysilane, p-styryltrimethoxysilane, trifluoropropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, and γ-glycidoxypropylmethyldiisopropoxysilane.

[0144] The content of the organosilicon compound can be 0.5 to 5.0 parts by weight, preferably 0.5 to 2.0 parts by weight, relative to 100 parts by weight of the cured organosilicon resin. If the content is 0.5 parts by weight or more, the desired adhesion can be easily ensured. On the other hand, if the content is 5.0 parts by weight or less, the adhesion to the resin layer of the object to be bonded will not be too strong, and peeling can be easily performed if peeling is originally required.

[0145] (wax)

[0146] Wax refers to waxes selected from natural waxes, synthetic waxes, and blends of these.

[0147] Natural waxes refer to plant-based waxes, animal-based waxes, mineral-based waxes, and petroleum waxes. Examples of plant-based waxes include candelilla wax, carnauba wax, rice bran wax, wood wax, and jojoba oil. Examples of animal-based waxes include beeswax, lanolin, and whale wax. Examples of mineral-based waxes include lignite wax, ceresin wax, and other similar products. Examples of petroleum waxes include paraffin wax, microcrystalline wax, and petroleum jelly.

[0148] Examples of synthetic waxes include synthetic hydrocarbons, modified waxes, hydrogenated waxes, fatty acids, amides, amines, imides, esters, and ketones. Examples of synthetic hydrocarbons include Fischer-Tropsch wax (also known as Sasol wax) and polyethylene wax. Furthermore, examples of low molecular weight polymers (specifically, polymers with a number average molecular weight of 500 to 20,000) include polypropylene, ethylene-acrylic acid copolymers, polyethylene glycol, polypropylene glycol, and block or graft copolymers of polyethylene glycol and polypropylene glycol. Examples of modified waxes include lignite wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives. Here, "derivative" refers to compounds obtained through any treatment such as purification, oxidation, esterification, saponification, or a combination thereof. Examples of hydrogenated waxes include hydrogenated castor oil and hydrogenated castor oil derivatives.

[0149] From the viewpoint of stable properties, synthetic waxes are preferred, with polyethylene waxes being more preferred, and oxidized polyethylene waxes being even more preferred. As for the number-average molecular weight of the synthetic wax, from the viewpoint of stability and operability of properties such as adhesion, a range of 500 to 30,000 is preferred, 1,000 to 15,000 is more preferred, and 2,000 to 8,000 is even more preferred.

[0150] Crosslinking agent

[0151] In the formation of the release layer, various crosslinking agents are preferably used to stabilize its properties such as firmness and water repellency. It is particularly preferred to use it in combination with organosilicon compounds containing polyether groups.

[0152] As crosslinking agents, conventionally known materials can be used, such as melamine compounds, epoxy compounds, oxazoline compounds, isocyanate compounds, carbodiimide compounds, silane coupling compounds, hydrazine compounds, and aziridine compounds. Among these, melamine compounds, epoxy compounds, isocyanate compounds, oxazoline compounds, carbodiimide compounds, and silane coupling compounds are preferred. Furthermore, from the viewpoint of maintaining appropriate water repellency and ensuring a firm release layer, melamine compounds, oxazoline compounds, and isocyanate compounds are preferred, with melamine compounds being particularly preferred. In addition, one type of these crosslinking agents can be used, or two or more types can be used in combination.

[0153] Melamine compounds refer to compounds containing a melamine backbone. Examples include compounds obtained by partially or completely etherifying alkylated melamine derivatives with an alcohol, and mixtures thereof. Suitable alcohols for etherification include methanol, ethanol, isopropanol, n-butanol, and isobutanol. Furthermore, melamine compounds can be monomers, polymers of two or more monomers, or mixtures thereof. Considering reactivity with various compounds, melamine compounds containing hydroxyl groups are preferred. Furthermore, compounds formed by fused urea or the like to a portion of melamine can also be used, and catalysts can be employed to enhance the reactivity of the melamine compound.

[0154] Oxazoline compounds refer to compounds containing an oxazoline group within their molecules, with polymers containing an oxazoline group being particularly preferred. These compounds can be prepared by polymerization of a monomer containing an addition-polymerizable oxazoline group, either alone or with other monomers. Examples of monomers containing an addition-polymerizable oxazoline group include 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-vinyl-5-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline, 2-isopropenyl-4-methyl-2-oxazoline, and 2-isopropenyl-5-ethyl-2-oxazoline, and mixtures of one or more of these monomers can be used. Among these, 2-isopropenyl-2-oxazoline is industrially readily available and suitable. Other monomers are unrestricted as long as they can copolymerize with monomers containing addition-polymerizable oxazoline groups. Examples include (meth)acrylates such as alkyl methacrylates (as alkyl groups, they are methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, cyclohexyl); unsaturated carboxylic acids such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, crotonic acid, styrene sulfonic acid and their salts (sodium salts, potassium salts, ammonium salts, tertiary amine salts, etc.); unsaturated nitriles such as acrylonitrile and methacrylonitrile; (meth)acrylamide, N-alkyl(methyl) Acrylamide, N,N-dialkyl(methyl)acrylamide, and other unsaturated amides (as alkyl groups, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, 2-ethylhexyl, cyclohexyl, etc.); vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether and ethyl vinyl ether; α-olefins such as ethylene and propylene; halogenated α,β-unsaturated monomers such as vinyl chloride, vinylidene chloride, and vinyl fluoride; and α,β-unsaturated aromatic monomers such as styrene and α-methylstyrene, etc., may use one or more of these monomers.

[0155] The amount of oxazoline group in the oxazoline compound is preferably in the range of 0.5–10 mmol / g, more preferably 1–9 mmol / g, even more preferably 3–8 mmol / g, and particularly preferably 4–6 mmol / g. By using it within the above range, the water-repellent properties become easier to adjust.

[0156] Isocyanate compounds refer to isocyanates, or compounds with isocyanate derivative structures, represented by terminally capped isocyanates. Examples of isocyanates include: aromatic isocyanates such as toluene diisocyanate, phenyl diisocyanate, methylene diphenyl diisocyanate, phenyl diisocyanate, and naphthalene diisocyanate; aliphatic isocyanates with aromatic rings such as α,α,α',α'-tetramethylphenyl diisocyanate; aliphatic isocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; aliphatic isocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, methylene bis(4-cyclohexyl) isocyanate, and isopropylidene dicyclohexyl diisocyanate. In addition, examples include polymers and derivatives of these isocyanates such as biuret compounds, isocyanurate compounds, urea diketides, and carbodiimide modifiers. These can be used alone or in combination. Among the aforementioned isocyanates, to avoid yellowing caused by ultraviolet light, aliphatic or alicyclic isocyanates are preferred over aromatic isocyanates.

[0157] When used in the form of a capped isocyanate, examples of capping agents include, for instance, phenolic compounds such as bisulfites, phenol, cresol, and ethylphenol; alcoholic compounds such as propylene glycol monomethyl ether, ethylene glycol, benzyl alcohol, methanol, and ethanol; active methylene compounds such as dimethyl malonate, diethyl malonate, methyl isobutyryl acetate, methyl acetoacetate, ethyl acetoacetate, and acetylacetone; thiol compounds such as butyl mercaptan and dodecyl mercaptan; lactam compounds such as ε-caprolactam and δ-valeronamide; amine compounds such as diphenylaniline, aniline, and ethyleneimine; amide compounds such as acetaniline and acetamide; and oxime compounds such as formaldehyde, acetaldehyde oxime, acetone oxime, methyl ethyl ketone oxime, and cyclohexanone oxime. These can be used alone or in combination of two or more. Of the above, isocyanate compounds capped with active methylene compounds are preferred, particularly from the viewpoint of effectively reducing the migration of the adhesive layer to the adhered material.

[0158] Isocyanate compounds can be used alone or as mixtures or combinations with various polymers. To improve the dispersibility and crosslinking properties of isocyanate compounds, mixtures or combinations with polyester resins and polyurethane resins are preferred.

[0159] Epoxy compounds refer to compounds containing epoxy groups within their molecules. Examples include condensates of epichlorohydrin with the hydroxyl and amino groups of ethylene glycol, polyethylene glycol, glycerol, polyglycerol, bisphenol A, etc., including polyepoxy compounds, diepoxy compounds, monoepoxy compounds, and glycidylamine compounds. Examples of polyepoxy compounds include sorbitol polyglycidyl ether, polyglycerol-based polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol-based polyglycidyl ether, triglycidyl tri(2-hydroxyethyl) isocyanate, glycerol-based polyglycidyl ether, and trimethylolpropane polyglycidyl ether. Examples of diepoxy compounds include neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcinol diglycidyl ether, and ethylene glycol diglycidyl ether. Glycidyl ethers, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polytetramethylene glycol diglycidyl ether are examples of monoepoxide compounds, such as allyl glycidyl ether, 2-ethylhexyl glycidyl ether, and phenyl glycidyl ether. Glycidyl amine compounds include N,N,N',N'-tetraglycidyl-m-phenylenediamine and 1,3-bis(N,N-diglycidylamino)cyclohexane.

[0160] From the perspective of various favorable properties, polyether-based epoxy compounds are preferred among those mentioned above. Furthermore, regarding the amount of epoxy groups, multifunctional polyepoxides with three or more functional groups are preferred compared to difunctional ones.

[0161] Carbodiimide compounds refer to compounds having one or more carbodiimide or carbodiimide derivative structures within their molecules. For better release layer strength, polycarbodiimide compounds having two or more molecules are preferred.

[0162] Carbodiimide compounds can be synthesized using conventionally known techniques, typically through the condensation reaction of diisocyanate compounds. There are no particular limitations on the diisocyanate compounds used; both aromatic and aliphatic compounds can be employed. Examples include toluene diisocyanate, xylene diisocyanate, diphenylmethane diisocyanate, benzene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, trimethylhexamethylene diisocyanate, cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexyl diisocyanate, and dicyclohexylmethane diisocyanate.

[0163] Furthermore, without impairing the effects of the present invention, in order to improve the water solubility and water dispersibility of polycarbodiimide compounds, surfactants, hydrophilic monomers such as polyepoxides, quaternary ammonium salts of dialkylamines, and hydroxyalkyl sulfonates may be added.

[0164] Silane coupling compounds are organosilicon compounds that contain organic functional groups and hydrolytic groups such as alkoxy groups in a single molecule. Examples include epoxy-containing compounds such as 3-epoxypropoxypropylmethyldimethoxysilane, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldiethoxysilane, 3-epoxypropoxypropyltriethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; vinyl-containing compounds such as vinyltrimethoxysilane and vinyltriethoxysilane; styryl-containing compounds such as p-styryltrimethoxysilane and p-styryltriethoxysilane; compounds containing styryl groups such as 3-(meth)acryloyloxypropyltrimethoxysilane, 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, and 3-(meth)acryloyloxypropylmethyldiethoxysilane; and compounds containing (meth)acryloyl groups such as 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane. Compounds containing amino groups, such as alkanes, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, 3-triethoxysilyl-N-(1,3-dimethylbutylidene)propylamine, N-phenyl-3-aminopropyltrimethoxysilane, N-phenyl-3-aminopropyltriethoxysilane, etc.; compounds containing isocyanurate groups, such as tri(trimethoxysilylpropyl) isocyanurate, tri(triethoxysilylpropyl) isocyanurate, etc.; and compounds containing mercapto groups, such as 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropylmethyldiethoxysilane, etc.

[0165] From the viewpoint of the strength of the release layer, among the above compounds, silane coupling compounds containing epoxy groups, silane coupling compounds containing double bonds such as vinyl and (meth)acryloyl groups, and silane coupling compounds containing amino groups are more preferred.

[0166] It should be noted that these crosslinking agents are designed to react during the drying and film-forming processes to improve the performance of the release layer. It can be inferred that unreacted products of these crosslinking agents, post-reaction compounds, or mixtures thereof may be present in the formed release layer.

[0167] <Various Polymers>

[0168] In the formation of the release layer, various polymers such as polyester resin, acrylic resin, polyurethane resin, and vinyl resin can be used to improve the coating appearance, transparency, control water repellency, and slip resistance. Among these polymers, polyester resin, acrylic resin, polyurethane resin, and vinyl resin are preferred from the viewpoint of easy control of water repellency, and polyester resin and acrylic resin are more preferred.

[0169] Polyester resin refers to, for example, those formed from polycarboxylic acids and polyhydroxy compounds as their main components. Specifically, as polycarboxylic acids, terephthalic acid, isophthalic acid, phthalic acid, 4,4'-diphenyldicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 2-sodium sulfoterephthalic acid, sodium isophthalate-5-sulfonate, adipic acid, azelaic acid, sebacic acid, dodecyl dicarboxylic acid, glutaric acid, succinic acid, trimellitic acid, pyromellitic acid, pyromellitic tetracarboxylic acid, trimellitic anhydride, phthalic anhydride, p-hydroxybenzoic acid, trimellitic acid monopotassium salt, and... Their esterifying derivatives, etc., as polyhydroxy compounds, can be ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 2-methyl-1,5-pentanediol, neopentanediol, 1,4-cyclohexanediol, p-phenylenediol, bisphenol A-ethylene glycol adduct, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene ether glycol, dimethylolpropionic acid, glycerol, trimethylolpropane, sodium dimethylol ethyl sulfonate, potassium dimethylolpropionate, etc. One or more of these compounds can be appropriately selected, or polyester resins can be synthesized through conventional polycondensation reactions.

[0170] Acrylic resins refer to polymers formed from polymerizable monomers containing acrylic acid and methacrylic acid monomers (hereinafter, acrylic acid and methacrylic acid are sometimes referred to together as (meth)acrylic acid). They can be homopolymers or copolymers, or copolymers with polymerizable monomers other than acrylic acid and methacrylic acid monomers.

[0171] Additionally, it includes copolymers of these polymers with other polymers (e.g., polyesters, polyurethanes, etc.). Examples include block copolymers and graft copolymers. It may also include polymers (mixtures of polymers, depending on the case) obtained by polymerizing polymeric monomers in a polyester solution or dispersion. Similarly, it includes polymers (mixtures of polymers, depending on the case) obtained by polymerizing polymeric monomers in a polyurethane solution or dispersion. Likewise, it includes polymers (mixtures of polymers, depending on the case) obtained by polymerizing polymeric monomers in other polymer solutions or dispersions.

[0172] The term "polymerizable monomer" is not particularly limited, but representative compounds include, for example, various carboxyl-containing monomers and their salts such as acrylic acid, methacrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid, and citraconic acid; various hydroxyl-containing monomers such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, monobutyl hydroxy fumarate, and monobutyl hydroxy fumarate; and methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and so on. Various (meth)acrylates such as lauryl acrylate; various nitrogen-containing compounds such as (meth)acrylamide, diacetone acrylamide, N-hydroxymethylacrylamide, or (meth)acrylonitrile; various styrene derivatives such as styrene, α-methylstyrene, divinylbenzene, and vinyltoluene; various vinyl esters such as vinyl propionate and vinyl acetate; various silicon-containing polymeric monomers such as γ-methacryloyloxypropyltrimethoxysilane and vinyltrimethoxysilane; phosphorus-containing vinyl monomers; various vinyl halides such as vinyl chloride and vinylidene chloride; and various conjugated dienes such as butadiene.

[0173] Polyurethane resin refers to a polymer compound with urethane bonds within its molecule. Polyurethane resin is typically produced by the reaction of polyols with isocyanates. Examples of polyols include polycarbonate polyols, polyester polyols, polyether polyols, polyolefin polyols, and acrylic polyols. These compounds can be used individually or in combination.

[0174] Polycarbonate polyols are obtained by reacting polyols with carbonate compounds via a dealcoholization reaction. Examples of polyols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanediol, 1,4-cyclohexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, neopentanediol, 3-methyl-1,5-pentanediol, and 3,3-dihydroxymethylheptane. Examples of carbonate compounds include dimethyl carbonate, diethyl carbonate, diphenyl carbonate, and ethylene carbonate. Examples of polycarbonate polyols obtained from these reactions include poly(1,6-hexanediol) carbonate and poly(3-methyl-1,5-pentanediol) carbonate.

[0175] Examples of polyester polyols include those composed of polycarboxylic acids (malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, octanoic acid, sebacic acid, fumaric acid, maleic acid, terephthalic acid, isophthalic acid, etc.) or their anhydrides and polyols (ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, neopentanediol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,5-pentanediol, etc.). It is obtained by reacting 2,4-pentanediol, 2-methyl-2-propyl-1,3-propanediol, 1,8-octanediol, 2,2,4-trimethyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol, 2,5-dimethyl-2,5-hexanediol, 1,9-nonanediol, 2-methyl-1,8-octanediol, 2-butyl-2-ethyl-1,3-propanediol, 2-butyl-2-hexyl-1,3-propanediol, cyclohexanediol, dihydroxymethylcyclohexane, dimethylbenzene, dihydroxyethoxybenzene, alkyldialkylolamine, lactone diol, etc.

[0176] Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polyethylene propylene glycol, polytetramethylene ether glycol, and polyhexamethylene ether glycol.

[0177] Examples of polyisocyanate compounds used to obtain polyurethane resins include aromatic diisocyanates such as toluene diisocyanate, phenyl diisocyanate, methylene diphenyl diisocyanate, phenyl diisocyanate, naphthalene diisocyanate, and benzyltoluidine diisocyanate; aliphatic diisocyanates with aromatic rings such as α,α,α',α'-tetramethylphenyl diisocyanate; aliphatic diisocyanates such as methylene diisocyanate, propylene diisocyanate, lysine diisocyanate, trimethylhexamethylene diisocyanate, and hexamethylene diisocyanate; alicyclic diisocyanates such as cyclohexane diisocyanate, methylcyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and isopropylidene dicyclohexyl diisocyanate. These can be used alone or in combination.

[0178] Chain extenders can be used when synthesizing polyurethane resins. As a chain extender, there are no particular restrictions as long as it has two or more active groups that react with isocyanate groups. Generally, chain extenders with two hydroxyl or amino groups can be used.

[0179] Examples of chain extenders with two hydroxyl groups include aliphatic diols such as ethylene glycol, propylene glycol, and butanediol; aromatic diols such as dimethylbenzene and dihydroxyethoxybenzene; and ester diols such as neopentyl glycol hydroxypentanoate. In addition, examples of chain extenders having two amino groups include aromatic diamines such as toluene diamine, phenylenediamine, and diphenylmethane diamine; aliphatic diamines such as ethylenediamine, propylenediamine, and hexanediamine; 2,2-dimethyl-1,3-propanediamine, 2-methyl-1,5-pentanediamine, trimethylhexanediamine, 2-butyl-2-ethyl-1,5-pentanediamine, 1,8-octanediamine, 1,9-nonanediamine, and 1,10-decanediamine; alicyclic diamines such as 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane, dicyclohexylmethanediamine, isopropylidenecyclohexyl-4,4'-diamine, 1,4-diaminocyclohexane, and 1,3-diaminomethylcyclohexane.

[0180] Polyurethane resins can be dispersed in solvents, but water is preferred. Methods for dispersing or dissolving polyurethane resins in water include: forced emulsification using emulsifiers, self-emulsification by introducing hydrophilic groups into the polyurethane resin, and water-soluble types. In particular, self-emulsifying liquids, which are ionomerized by introducing ionic groups into the structure of the polyurethane resin, are preferred due to their excellent storage stability, water resistance of the resulting release layer, and transparency.

[0181] In addition, various groups such as carboxyl groups, sulfonic acid groups, phosphoric acid groups, phosphonic acid groups, and quaternary ammonium salts can be used as introduced ionic groups, with carboxyl groups being preferred. Various methods can be adopted at different stages of the polymerization reaction to introduce carboxyl groups into the polyurethane resin. For example, methods include using a resin containing carboxyl groups as a copolymer component during prepolymer synthesis, and using a component containing carboxyl groups as a component such as a polyol, polyisocyanate, or chain extender. A method using a carboxyl-containing diol, introducing a desired amount of carboxyl groups based on the amount of this component added, is particularly preferred. For example, diol copolymers used in the polymerization of polyurethane resins can be dimethylolpropionic acid, dimethylolbutyric acid, bis-(2-hydroxyethyl)propionic acid, bis-(2-hydroxyethyl)butyric acid, etc. Furthermore, the carboxyl group preferably forms a salt neutralized by ammonia, amine, alkali metals, inorganic bases, etc. Ammonia, trimethylamine, and triethylamine are particularly preferred. The aforementioned polyurethane resin can use the carboxyl groups from which the neutralizing agent has been removed during the drying process after coating as crosslinking reaction sites based on other crosslinking agents. Therefore, the excellent stability in the liquid state before coating can further improve the durability, solvent resistance, water resistance, and anti-blocking properties of the resulting release layer.

[0182] Antistatic agent

[0183] Furthermore, including an antistatic agent in the release layer is a preferred method to prevent defects such as film peeling and charging, and the adhesion of surrounding dust and other contaminants caused by frictional charging. There are no particular limitations on the antistatic agent used in the release layer; conventionally known antistatic agents can be used. However, polymeric antistatic agents are preferred due to their good heat resistance and resistance to damp heat. Examples of polymeric antistatic agents include compounds with ammonium groups, polyether compounds, compounds with sulfonic acid groups, amphoteric compounds, and conductive polymers.

[0184] Compounds containing an ammonium group refer to compounds that have an ammonium group within their molecules. Examples include ammonium compounds of aliphatic amines, alicyclic amines, and aromatic amines. Preferably, the ammonium group is a polymeric compound containing an ammonium group, and the ammonium group is preferably incorporated into the main chain or side chain of the polymer rather than acting as a counterion. For example, polymers formed by polymerizing monomers containing ammonium groups such as addition-polymerizable ammonium groups or amines as precursors are suitable for use. As polymers, monomers containing addition-polymerizable ammonium groups such as ammonium groups or amines as precursors can be homopolymerized, or copolymers of monomers containing these groups with other monomers can be used.

[0185] Among compounds with ammonium groups, those with pyrrolidine rings are preferred due to their excellent antistatic properties and thermal stability.

[0186] In compounds containing a pyrrolidine ring, the two substituents bonded to the nitrogen atom are each independently alkyl, phenyl, etc., and these alkyl or phenyl groups can be substituted by groups listed below. Substitutable groups include, for example, hydroxyl, amide, ester, alkoxy, phenoxy, naphthoxy, thioalkoxy, thiophenoxy, cycloalkyl, trialkylammonium alkyl, cyano, and halogen. Furthermore, the two substituents bonded to the nitrogen atom can be chemically bonded, for example, -(CH2). m -(m=an integer from 2 to 5), -CH(CH3)CH(CH3)-, -CH=CH-CH=CH-, -CH=CH-CH=N-, -CH=CH-N=CH-, -CH2OCH2-, -(CH2)2O(CH2)2-, etc.

[0187] Polymers containing pyrrolidine rings are obtained by cyclizing diallylamine derivatives using a free radical polymerization catalyst. The polymerization can be carried out using known, but not limited to, methods in polar solvents such as water, methanol, ethanol, isopropanol, formamide, dimethylformamide, dioxane, or acetonitrile, with polymerization initiators such as hydrogen peroxide, benzoyl peroxide, or tert-butyl peroxide. In this invention, diallylamine derivatives can be copolymerized with compounds having polymerizable carbon-carbon unsaturated bonds.

[0188] Furthermore, polymers with the following general formula (4) are preferred in terms of excellent antistatic properties and resistance to humid heat. Homopolymers and copolymers can be further copolymerized with other components.

[0189]

[0190] For example, in the above formula, the substituent R 1 R is a hydrogen atom or a hydrocarbon group such as an alkyl or phenyl group with 1 to 20 carbon atoms. 2 For -O-, -NH-, or -S-, R 3 R is an alkylene group having 1 to 20 carbon atoms or other structures that can form the general formula (4). 4 R 5 R 6 Each is a hydrocarbon group that is independently endowed with a functional group, such as a hydrogen atom, an alkyl group with 1 to 20 carbon atoms, a phenyl group, or a hydroxyalkyl group, etc. - For various counter ions.

[0191] In the above, especially regarding the excellent antistatic properties and resistance to damp heat, in general formula (4), the substituent R 1 Preferably, it is an alkyl group with 1 to 6 carbon atoms, R 3 Preferably, it is an alkyl group having 1 to 6 carbon atoms, R 4 R 5 R 6 Preferably, each is an alkyl group having a hydrogen atom or a carbon number of 1 to 6, and more preferably R. 4 R 5 R 6 One of them is a hydrogen atom, and the other substituents are alkyl groups having 1 to 4 carbon atoms.

[0192] Examples of anions that can become counterions (anti-ions) of the ammonium groups in the aforementioned compounds containing ammonium groups include ions such as halide ions, sulfonate ions, phosphate ions, nitrate ions, alkyl sulfonate ions, and carboxylate ions.

[0193] Furthermore, the number average molecular weight of the compounds containing ammonium groups is 1,000 to 500,000, preferably 2,000 to 350,000, and more preferably 5,000 to 200,000. If the molecular weight is above 1,000, the coating film has sufficient strength and maintains heat resistance stability. Conversely, if the molecular weight is below 500,000, the viscosity of the coating solution becomes lower, resulting in good workability and coatability.

[0194] Examples of polyether compounds include acrylic resins with side chains containing polyethylene oxide, polyether ester amide, or polyethylene glycol.

[0195] Compounds with sulfonic acid groups are compounds that contain sulfonic acid or sulfonates within their molecules, such as compounds suitable for use with polystyrene sulfonic acid, or compounds in which sulfonic acid or sulfonates are present in large quantities.

[0196] Examples of conductive polymers include polythiophene-based, polyaniline-based, polypyrrole-based, and polyacetylene-based polymers. Among these, polythiophene-based polymers, such as those combining poly(3,4-ethylenedioxythiophene) with polystyrene sulfonic acid, are particularly suitable. Conductive polymers are advantageous compared to the other antistatic agents mentioned above in terms of lower resistivity. However, in applications where coloring and cost are important, efforts to reduce the dosage are necessary.

[0197] Furthermore, without prejudice to the spirit of the present invention, defoamers, coatability modifiers, thickeners, organic lubricants, ultraviolet absorbers, antioxidants, foaming agents, dyes, pigments, etc. may also be used in combination in the release layer as needed.

[0198] <Ratio of release agent>

[0199] The proportion of the release agent in the release layer varies depending on the type of release agent, and therefore cannot be generalized. A range of 3% by mass or more is preferred, more preferably 15% by mass or more, and even more preferably 25% to 99% by mass. If it is 3% by mass or more, sufficient water repellency is obtained.

[0200] When using long-chain alkyl compounds or fluorinated compounds as release agents, the proportion in the release layer is preferably 5% by mass or more, more preferably 15 to 99% by mass, even more preferably 20 to 95% by mass, and particularly preferably 25 to 90% by mass. By using it within the above range, water repellency and peelability from the adhesive layer become effective.

[0201] In addition, the proportion of crosslinking agent is preferably 95% by mass or less, more preferably 1 to 80% by mass, even more preferably 5 to 70% by mass, and particularly preferably 10 to 50% by mass. As a crosslinking agent, melamine compounds, oxazoline compounds, and isocyanate compounds are preferred. From the viewpoint of water repellency and the strength of the release layer, melamine compounds are particularly preferred.

[0202] When using an addition-type silicone compound as a release agent, the proportion in the release layer is preferably 5% by mass or more, more preferably 25% by mass or more, further preferably 50% by mass or more, and particularly preferably 70% by mass or more. The upper limit of the preferred range is 99% by mass, and the upper limit is more preferably 90% by mass. By using it within the above range, water repellency and peelability from the adhesive layer become effective, and the appearance of the release layer also becomes better.

[0203] Furthermore, when using a polyether-based silicone as a release agent, the proportion in the release layer is preferably 5% by mass or more, more preferably 10% by mass or more, even more preferably 25% by mass or more, and particularly preferably 40% by mass or more. The upper limit of the preferred range is 99% by mass, the more preferred upper limit is 80% by mass, and the even more preferred upper limit is 70% by mass. By using it within the above range, water repellency and peelability from the adhesive layer become effective, and the appearance of the release layer also becomes better.

[0204] In addition, the proportion of the crosslinking agent is preferably 90% by mass or less, more preferably 10 to 70% by mass, and even more preferably 20 to 40% by mass.

[0205] When wax is used as a release agent, its proportion in the release layer is preferably 5% by mass or more, more preferably 10 to 90% by mass, even more preferably 20 to 80% by mass, and particularly preferably 25 to 70% by mass. By using it within the above range, the water repellency becomes good.

[0206] Furthermore, the proportion of the crosslinking agent is preferably 90% by mass or less, more preferably 10 to 70% by mass, and even more preferably 20 to 50% by mass. Additionally, from the viewpoint of water repellency and the strength of the release layer, melamine compounds are preferred as the crosslinking agent.

[0207] <Proportion of antistatic agent>

[0208] Furthermore, when an antistatic release layer with antistatic properties is provided as the release layer, the appropriate amount of antistatic agent varies depending on the type of antistatic agent. Therefore, it cannot be generalized. It is preferred to be in the range of 0.5% by mass or more, more preferably 3 to 90% by mass, even more preferably 5 to 70% by mass, and particularly preferably 8 to 60% by mass.

[0209] When an antistatic agent other than a conductive polymer is used as the antistatic agent, the proportion in the antistatic release layer is preferably 5% by mass or more, more preferably 10 to 90% by mass, further preferably in the range of 20 to 70% by mass, and particularly preferably in the range of 25 to 60% by mass.

[0210] When a conductive polymer is used as an antistatic agent, the proportion in the antistatic release layer is preferably 0.5% by mass or more, more preferably 3 to 70% by mass, even more preferably 5 to 50% by mass, and particularly preferably 8 to 30% by mass.

[0211] The composition of the release layer can be analyzed using methods such as TOF-SIMS, ESCA, fluorescence X-ray, and IR.

[0212] On the other hand, as an example, when setting the release layer by offline coating, a case using a curable silicone resin will be explained.

[0213] As mentioned above, as a type of curable silicone resin, it can be used with any existing curing reaction type, such as addition / condensation type thermosetting type, ultraviolet curing type, or electron beam curing type. In addition, multiple types of curable silicone resins can be used in combination. There are no particular restrictions on the coating form of the cured silicone resin when forming the release layer; it can be in the form of being dissolved in an organic solvent, in the form of an aqueous emulsion, or in a solvent-free form.

[0214] Regarding the formation of the release layer, it is preferable to coat the film with a liquid that has been adjusted to a solid content of approximately 0.1% to 80% by mass, forming a solution or dispersion of the aforementioned series of compounds. Especially in the case of an online coating setup, an aqueous solution or aqueous dispersion is more preferred. For purposes such as improving water dispersibility and film-forming properties, the coating liquid may contain a small amount of organic solvent. Furthermore, only one type of organic solvent may be used, or two or more types may be suitable.

[0215] <Method for forming the release layer>

[0216] Methods for forming a release layer include, for example, coating, transfer printing, and lamination. Considering the ease of forming the release layer, coating is the preferred method.

[0217] As a coating-based method, it can be set up through online coating performed within the film manufacturing process, or through offline coating applied to a temporarily manufactured film outside the system.

[0218] Online coating is a method of coating at any stage after the resin for forming the film has been melted and extruded, stretched, heat-set, and rolled up. Generally, it can be applied to any of the following: unstretched sheets obtained by melting and quenching, stretched uniaxially stretched films, biaxially stretched films before heat setting, and films after heat setting and before rolling up. It is not limited to these, but for example, in sequential biaxial stretching, a method of coating a uniaxially stretched film stretched along its length (longitudinal direction) followed by stretching in the transverse direction is particularly advantageous. According to the above method, film formation and release layer formation can be performed simultaneously, thus offering advantages in manufacturing costs. Furthermore, since stretching is performed after coating, the thickness of the release layer can be varied according to the stretch ratio, making film coating easier compared to offline coating.

[0219] Furthermore, by providing a release layer on the film before stretching, the release layer can be stretched together with the substrate film, thereby ensuring that the release layer is firmly and tightly bonded to the substrate film. Moreover, in the manufacture of biaxially stretched polyester film, stretching is performed while the film ends are fixed by clamps or the like, thus binding the film both longitudinally and laterally. During the heat setting process, high temperatures can be applied while maintaining planarity without introducing wrinkles.

[0220] Therefore, the heat treatment performed after coating can be set to a high temperature that is impossible to achieve by other methods. This improves the film-forming properties of the release layer, allowing for a stronger and more secure adhesion between the release layer and the substrate film, further forming a robust release layer. In particular, inducing the crosslinking agent to react is very effective in demonstrating stable water-repellent properties.

[0221] As for coating methods, conventionally known coating methods can be used, such as gravure coating, reverse roller coating, die coating, air knife coating, blade coating, rod coating, bar coating, curtain coating, knife coating, transfer roller coating, extrusion coating, impregnation coating, lip coating, spray coating, calendering coating, and extrusion coating.

[0222] There are no particular limitations on the drying and curing conditions when forming the release layer on the film. In the case of a coating method, the drying temperature of the solvent such as water used in the coating solution is preferably in the range of 70 to 150°C, more preferably 80 to 130°C, and even more preferably 90 to 120°C. The drying time is, as a target, in the range of 3 to 200 seconds, preferably 5 to 120 seconds.

[0223] In addition, heat treatment can be combined with irradiation by active energy rays such as ultraviolet light, as needed. Surface treatments such as corona treatment and plasma treatment can be pre-treated on polyester films.

[0224] Polyester films have an adhesive layer on the release layer. There are no particular limitations on how the adhesive layer is applied, including methods such as bonding the adhesive layer, which is applied to a release substrate, to another resin film; and directly applying a coating liquid containing adhesive layer components.

[0225] In methods involving bonding with a release substrate, care must be taken to prevent air bubbles and wrinkles from entering during bonding. However, this method has the advantage of not requiring heat treatment for the adhesive film used in the final product. In direct coating methods, heat is applied to the film during the application of the adhesive layer for drying and curing. Therefore, variations in film shrinkage must sometimes be considered, but this method also results in a more uniform adhesive layer. Generally, the appropriate method can be chosen based on the composition and purpose of the final product.

[0226] [Average surface roughness (arithmetic mean height; Sa) and maximum peak height (Sp) of the release layer surface]

[0227] The average surface roughness (Sa) of the release layer surface of the release film of the present invention is 200 nm or more. If it is less than 200 nm, drainage or debubbling becomes insufficient when bonded to the adhered object. From the above viewpoint, the average surface roughness (Sa) of the release layer surface is further preferably 250 nm or more. On the other hand, from the viewpoint of the transparency of the release film of the present invention, it is preferably 500 nm or less, more preferably 450 nm or less, and even more preferably 420 nm or less.

[0228] Furthermore, the maximum peak height (Sp) of the release layer surface of the release film of the present invention is 300 nm or more. If it is less than 300 nm, drainage or degassing becomes insufficient when bonded to the substrate. From the above viewpoint, the maximum peak height (Sp) of the release layer surface is preferably 350 nm or more, and more preferably 400 nm or more. On the other hand, from the viewpoint of the transparency of the release film of the present invention, it is preferably 1000 nm or less, more preferably 800 nm or less, and more preferably 650 nm or less.

[0229] It should be noted that surface roughness (Sa, arithmetic mean height, ISO 25178 surface properties) is a parameter that expands Ra (arithmetic mean height of a line) to a surface, and represents the average value of the absolute values ​​of the height differences between points on the average surface. Furthermore, maximum peak height (Sp) is obtained by expanding the two-dimensional maximum peak height (Rp) to three dimensions, and is the maximum height of the surface whose height from the measurement area is 0.

[0230] [Protrusion height (X) and number of protrusions (Y)]

[0231] The distribution curve representing the relationship between the protrusion height (X) and the number of protrusions (Y) on the surface of the release layer of the release film of the present invention satisfies the following equation (1). By satisfying the following equation (1), drainage or debubbling becomes easier when bonded to the adhered object. From the above viewpoint, -(logY2-logY1) / (X2-X1) is more preferably 1.2 or more, and even more preferably 1.3 or more. There is no particular limitation on the upper limit value, but from the viewpoint of the transparency of the release film, it is preferably 3.0 or less, and even more preferably 2.5 or less.

[0232] -(logY2-logY1) / (X2-X1)≥1.0 (1)

[0233] Here, Y1 and Y2 represent the number (pieces / mm) of protrusions on the surface of the release layer when the protrusion heights are X1 = 0.98 μm and X2 = 1.98 μm, respectively. 2 ).

[0234] The above formula (1) in this invention is a collection that combines the number of protrusions of each protrusion height.

[0235] Generally, even when using pinpoints to define the protrusion height, the surface irregularities of the thin film as described in this invention are considered to be suitable for a three-dimensional top-down view, regardless of the arbitrary shape of the irregularities. Specifically, by selecting two points, 0.98 μm and 1.98 μm, representing the protrusion height on the thicker side where debubbling effects are expected, and varying the slope of the straight line between these two points, the area enclosed by the straight line is considered suitable for the purposes of this invention.

[0236] Further optimization of the number of protrusions with a height of 0.98 μm can simultaneously satisfy 1000 protrusions / mm. 2 The above. More preferably, the number of protrusions is 2000 per mm. 2 Above, further optimization to 3000 pieces / mm 2 above.

[0237] In addition, the number of protrusions with a height of 1.98 μm or more is preferably 3 per mm. 2 The above, more preferably, has 10 protrusions per mm. 2 Above, further optimization to 30 pieces / mm 2 The above. In particular, based on simultaneously satisfying the aforementioned conditions (the conditions of the above formula (1) and the condition of the number of protrusions with a protrusion height of 0.98 μm), as an additional feature, it is possible to satisfy that the number of protrusions with a protrusion height of 1.98 μm or more is 3 per mm. 2 above.

[0238] By meeting the aforementioned requirements, the degassing effect becomes good when the adhesive sheet with the release film is applied to the substrate.

[0239] [Degassing Index]

[0240] The degassing index of the demolding surface is below 2000 seconds, preferably below 1500 seconds, and even more preferably below 1000 seconds, and especially below 500 seconds.

[0241] By satisfying the aforementioned range, air is rapidly removed from the gap, indicating a shape in which air is well removed.

[0242] It should be noted that the degassing index can be determined according to the method described in the examples.

[0243] <Adhesive Layer>

[0244] The release film of the present invention is a film for protecting the adhesive layer. The adhesive layer used herein is preferably any one of silicone adhesive layer, acrylic adhesive layer and urethane adhesive layer.

[0245] (Silicone-based adhesive layer)

[0246] The silicone adhesive that constitutes the silicone-based adhesive layer can be any adhesive that uses silicone as the main component of the resin.

[0247] The "main component resin" refers to the resin that constitutes the adhesive and has the highest proportion (by mass) of it.

[0248] Examples of silicone adhesives include addition-reaction type, peroxide-curing type, and condensation-reaction type silicone adhesives. From the viewpoint of curing at low temperatures and for a short time, addition-reaction type silicone adhesives are preferred. It should be noted that these addition-reaction type silicone adhesives are cured when an adhesive layer is formed on a support. When using addition-reaction type silicone adhesives, the aforementioned silicone adhesives may also contain a catalyst such as a platinum catalyst.

[0249] For example, addition-reactive silicone adhesives can be cured as follows, depending on the requirements: a silicone resin solution diluted with a solvent such as toluene is stirred to achieve uniformity by adding a catalyst such as a platinum catalyst, then applied to a support and cured at 100–130°C for 1–5 minutes. Alternatively, depending on the requirements, a crosslinking agent, additives for controlling adhesion, or a primer treatment of the substrate film can be added to the addition-reactive silicone adhesive.

[0250] Commercially available silicone resins used in addition-reaction silicone adhesives include, for example, SD4580PSA, SD4584PSA, SD4585PSA, SD4587LPSA, SD4560PSA, SD4570PSA, SD4600FCPSA, SD4593PSA, DC7651ADHESIVE, DC7652ADHESIVE, LTC-755, and LTC-310 (all DOW CORNING). (Manufactured by TORAYCOMPANY,LTD.), KR-3700, KR-3701, KR-3704, X-40-3237-1, X-40-3240, X-40-3291-1, X-40-3229, X-40-3323, X-40-3306, X-40-3270-1 (all manufactured by Shin-Etsu Chemical Industry Co., Ltd.), AS-PSA001, AS-PSA002, AS-PSA003, AS-PSA004, AS-PSA005, AS-PSA012, AS-PSA014, PSA-7465 (all manufactured by Arakawa Chemical Industry Co., Ltd.), TSR1512, TSR1516, TSR1521 (all manufactured by Momentive Performance Materials Inc.), etc.

[0251] (Acrylic adhesive layer)

[0252] Acrylic adhesive layers can be formed from adhesive compositions containing (meth)acrylate (co)polymers, and, if necessary, photopolymerization initiators, crosslinking agents, silane coupling agents, and other materials. Acrylic adhesive layers can be formed from conventionally known adhesive compositions, such as those described in Japanese Patent Application Publication No. 2019-210446.

[0253] (Carbamate-based adhesive layer)

[0254] A urethane-based adhesive layer can be formed using the urethane-based adhesives described below.

[0255] As a urethane-based adhesive, the urethane-based base polymer can be a reactant of polyols and polyisocyanate compounds.

[0256] Examples of polyol components include high molecular weight polyols such as polyester polyols, polyether polyols, polycarbonate polyols, and caprolactone polyols. These polyol components can be used alone or in combination of two or more.

[0257] Examples of polyisocyanate compounds include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanates. These polyisocyanate compounds can be used alone or in combination of two or more.

[0258] (Thickness of the adhesive layer)

[0259] The thickness of the adhesive layer (after drying) is preferably 1–100 μm, more preferably 5–80 μm, further preferably 10–60 μm, and particularly preferably 20–50 μm.

[0260] If the value is above the lower limit mentioned above, sufficient adhesive force is obtained; if the value is below the upper limit mentioned above, the operation is easy.

[0261] (Total thickness of the release film with adhesive layer)

[0262] From an operational point of view, the total thickness of the release film with the adhesive layer is preferably 500 μm or less, more preferably 40 μm or more and 350 μm or less, even more preferably 40 μm or more and 200 μm or less, and even more preferably 50 μm or more and 150 μm or less.

[0263] [Thin Film Laminate]

[0264] As a first embodiment of the film laminate, a substrate film (A) is attached to the release layer of the aforementioned release film, with an adhesive layer in between. The release layer and adhesive layer are as described above.

[0265] (Substrate film (A))

[0266] Examples of substrate films (A) include resin films formed from polymers such as polyethylene, polypropylene, cyclic olefin polymers (COP), polyester, polystyrene, acrylic resins, polycarbonate, polyurethane, cellulose triacetate (TAC), polyvinyl chloride, polyethersulfone, polyamide, polyimide, and polyamide-imide. Furthermore, any material suitable for film formation can be a mixture of these materials (polymer blend) or a composite of structural units (polymer). Among these, polyurethane films are preferred due to their moderate flexibility and good handling properties.

[0267] The thickness of the substrate film (A) is preferably 25-350 μm, more preferably 50-250 μm, further preferably 75-200 μm, and particularly preferably 75-150 μm.

[0268] Furthermore, in order to impart various functions such as stain resistance, water repellency, antistatic properties, weather resistance, fingerprint resistance, and hard coating properties to the surface of the aforementioned substrate film (A), a functional layer may also be provided. Additionally, a printing layer may also be provided.

[0269] (Surface roughness (Sa) of the adhesive layer surface)

[0270] The surface roughness (arithmetic mean height; Sa) of the adhesive layer surface after the release film of the present invention is preferably 200 nm or more. This surface roughness of 200 nm or more is suitable because it results in less moisture or bubble residue when bonded to the adhered object. From the above viewpoint, the surface roughness of the adhesive layer surface is more preferably 250 nm or more, and even more preferably 300 nm or more. On the other hand, from the viewpoint of the transparency of the adhesive film formed by the substrate (A) and the adhesive layer, this surface roughness is preferably 600 nm or less, more preferably 500 nm or less, and even more preferably 400 nm or less.

[0271] The surface roughness of the adhesive layer is formed by the surface roughness of the transfer release layer. Therefore, the surface roughness of the adhesive layer can be controlled by controlling the surface roughness of the release layer and the elastic modulus of the adhesive layer.

[0272] It should be noted that, from the viewpoint of the transfer rate of the surface shape of the release layer to the surface of the adhesive layer, the ratio of Sa of the adhesive layer surface to Sa of the release layer surface is preferably 0.9 or higher. If it is 0.9 or higher, it can be said that the surface shape of the release layer is reproduced with good accuracy.

[0273] (Elastic modulus of the adhesive layer)

[0274] The elastic modulus of the adhesive layer at 25°C is preferably 20 MPa or higher. If this elastic modulus is 20 MPa or higher, the adhesive layer will not be leveled off due to unevenness transferred from the release layer, making it easier to achieve the aforementioned surface roughness (Sa). On the other hand, the elastic modulus of the adhesive layer is preferably 80 MPa or lower. If it is 80 MPa or lower, it has moderate flexibility, suitable for transferring the surface roughness (Sa) of the release layer. From the above viewpoints, the elastic modulus of the adhesive layer at 25°C is more preferably in the range of 20 MPa to 80 MPa, and even more preferably in the range of 20 MPa to 60 MPa.

[0275] It should be noted that the elastic modulus of the adhesive layer is a value measured according to the method described in the embodiments.

[0276] The thickness of the adhesive layer is not particularly limited, but it is preferably 1–100 μm, more preferably 5–80 μm, and even more preferably 10–60 μm, and particularly preferably 20–50 μm. By satisfying the aforementioned range, good adhesive properties can be achieved.

[0277] If the value is above the lower limit mentioned above, sufficient adhesive force is obtained; if the value is below the upper limit mentioned above, the operation is easy.

[0278] <Method for manufacturing thin film laminates>

[0279] The method for manufacturing the film laminate of the present invention is not particularly limited. For example, an adhesive layer can be formed by applying an adhesive layer forming liquid to the release layer of the release film of the present invention using an applicator, and then bonding the substrate film (A) onto the adhesive layer. The method for applying the adhesive layer forming liquid is not particularly limited and can be performed using conventionally known methods. In addition, as described above, a functional layer can also be provided on the side of the substrate film opposite to the surface in contact with the adhesive layer.

[0280] The film laminate of the present invention, as described below, is suitable for use as a release film for adhesive layer protection. However, in the manufacturing method of the release film for adhesive layer protection, it is preferable that the substrate film (B) is a multilayer film, comprising a polyester layer containing particles only on the surface, wherein the polyester layer in contact with the release layer contains particles with an average particle size of 1.0 to 4.5 μm, the amount of which is added is 1 to 10% by mass, and the difference between the longitudinal stretch ratio and the transverse stretch ratio is within 0.2 times. By employing this method, it becomes advantageous to have minimal variation in the unevenness of the film collection location.

[0281] Furthermore, the longitudinal stretching ratio is preferably 3.0 to 4.5 times, and the transverse stretching ratio is preferably 3.5 to 5.0 times.

[0282] <Applications>

[0283] The release film for adhesive layer protection and the film laminate of the present invention are useful as PPF (paint protection film) for the purpose of protecting automotive coatings. They are also useful as polishing films for polishing adhesive films printed on automobiles, railways, trams, airplanes, etc. According to the release film for adhesive layer protection and the film laminate of the present invention, when a large area of ​​adhesive film as described above is adhered to an object, adhesion can be performed easily and uniformly.

[0284] Example

[0285] The present invention will now be described in further detail with reference to embodiments, but the invention is not limited to the following embodiments as long as it does not deviate from its spirit. Furthermore, the measurement and evaluation methods used in the present invention are described below.

[0286] (1) Method for determining the intrinsic viscosity of polyester

[0287] Accurately weigh 1g of polyester, add 100ml of a mixed solvent of phenol / tetrachloroethane = 50 / 50 (mass ratio) to dissolve it, and perform the determination at 30℃.

[0288] (2) Average particle size (d) 50Method for determining μm

[0289] The average particle size is taken as the cumulative (mass standard) 50% of the equivalent spherical distribution measured using a centrifugal sedimentation particle size distribution measuring device (SA-CP3 type manufactured by Shimadzu Corporation).

[0290] (3) Methods for determining number-average molecular weight

[0291] The molecular weight was determined using GPC (HLC-8120GPC manufactured by Tosoh Corporation). The number-average molecular weight was calculated based on polystyrene.

[0292] (4) Elastic modulus of the adhesive layer

[0293] The elastic modulus at an indentation depth of 50 nm was measured at room temperature (25 °C) using a Hysitron nanoindenter (TI 950 Tribo Indenter).

[0294] (5) Distribution curve of the release layer surface and determination of the number of protrusions with a height of 0.98 μm or higher.

[0295] Using a surface shape measurement system (Hitachi High-Tech Science Corporation's "VertScan" (registered trademark) R5500), the surface roughness of a 237.65 μm × 178.25 μm region on the surface of the release film (sample) was measured by optical interferometry. The relationship between the protrusion height per 0.1 μm and the number of protrusions at each height was graphically represented as a distribution curve. The number of protrusions at heights X1 μm and X2 μm was set as Y1 protrusions / mm. 2 Y2 pieces / mm 2 It should be noted that the protrusion heights X1 and X2 are set to 0.98μm and 1.98μm, respectively.

[0296] (6) Birefringence (Δn×10 3 )

[0297] Birefringence (Δn×10⁻¹⁵) was measured using a microwave molecular orientation meter (model: MOA-6015) manufactured by Oji Measurement Machines Co., Ltd. 3 ).

[0298] (7) Degassing index

[0299] The release film (sample) was cut into 70mm square pieces. The release film was then laminated with a polyester film with a 5mm diameter hole in the center, with the release layer surface of the release film in contact with the polyester film. The degassing index was then measured.

[0300] The degassing index was determined as follows: A Digi-Bekk smoothness testing machine (DB-2, manufactured by Toyo Seiki Co., Ltd.) was used under conditions of 23°C and 50% RH. A small vacuum container with a volume of 38 ml and a pressure of 100 kPa was used. The time it took for 1 mL of air to flow through the container, i.e., the time it took for the pressure inside the container to change from 50.7 kPa to 48.0 kPa (in seconds), was measured. Ten times the obtained number of seconds was taken as the degassing index.

[0301] The smaller the degassing index value, the faster the air is removed from the gap, indicating a shape where air is effectively removed.

[0302] (8) Surface roughness (arithmetic mean height; Sa) of the adhesive layer after the release film is peeled off.

[0303] An adhesive layer consisting of the following adhesive layers was applied to the surface of the release layer of the sample film to a thickness (after drying) of 20 μm, and then dried. A 75 μm PET film was then bonded to the exposed adhesive layer surface. Afterward, the release film was peeled off from the adhesive layer surface, and the arithmetic mean height (Sa) of the adhesive layer surface was measured using a surface shape measurement system (Hitachi High-Tech Science Corporation's "VertScan" (registered trademark) R5500).

[0304] It should be noted that the elastic modulus of the adhesive layer at 25℃ is 20MPa.

[0305] Adhesive Compositions

[0306] Main component (acrylic resin): AT352 (manufactured by SAIDEN CHEMICAL INDUSTRY CO.,LTD.) 100 parts by weight

[0307] Crosslinking agent: 0.25 parts by weight of AL (manufactured by SAIDEN CHEMICAL INDUSTRY CO.,LTD.)

[0308] Additive: X-301-375SK (manufactured by SAIDEN CHEMICAL INDUSTRY CO.,LTD.) 0.25 parts by weight

[0309] Additive: X-301-352S (manufactured by SAIDEN CHEMICAL INDUSTRY CO.,LTD.) 0.25 parts by weight

[0310] Solvent: Toluene: 40 parts by weight

[0311] (9) Gloss (60 degrees)

[0312] The 60-degree gloss of the cured resin layer surface of the laminated film was measured using a VG-2000 manufactured by Nippon Denshoku Kogyo.

[0313] (10) Risk of particles detaching from the surface of the self-demolding film

[0314] The risk of particles detaching from the surface of the self-release film is assessed.

[0315] (Judgment Criteria)

[0316] A: The slope of the roughness distribution curve is above 1.0, therefore, the risk of particles detaching from the film surface is low, and there is no problem.

[0317] B: The slope of the roughness distribution curve is less than 1.0, therefore, there is a high risk of particles detaching from the film surface, resulting in a decrease in operability.

[0318] Examples and comparative examples are shown below, and the methods for manufacturing the polyester used in the examples and comparative examples are described below.

[0319] <Manufacturing Method of Polyester (A)>

[0320] Starting with 100 parts by mass of dimethyl terephthalate and 55 parts by mass of ethylene glycol, and 0.04 parts by mass of magnesium acetate tetrahydrate as a catalyst, the reaction was introduced into a reactor. The initial reaction temperature was set at 150°C, and the temperature was slowly increased while methanol was distilled off. After 3 hours, the temperature was set to 230°C. After 4 hours, the transesterification reaction was essentially completed. Then, 0.02 parts by mass of ethyl phosphate and 0.04 parts by mass of antimony trioxide were added to the reaction mixture, and a polycondensation reaction was carried out for 4 hours. That is, the temperature was slowly increased from 230°C to 280°C. Simultaneously, the pressure was slowly decreased from atmospheric pressure, eventually reaching 0.3 mmHg. After the reaction started, the reaction was stopped at the point when the intrinsic viscosity was equivalent to 0.65, based on changes in the stirring power of the reaction vessel. The polymer was then discharged under nitrogen pressure, yielding polyester (A) with an intrinsic viscosity of 0.65.

[0321] <Manufacturing Method of Polyester (B)>

[0322] Polyester (B) was obtained by adding 3.5% by mass of silica particles with an average primary particle size of 4.1 μm to the above-mentioned polyester (A), which is substantially free of particles, and then mixing it with a vented twin-screw mixer.

[0323] <Manufacturing Method of Polyester (C)>

[0324] Polyester (C) was obtained by adding 0.3% by mass of silica particles with an average primary particle size of 2.4 μm to the above-mentioned polyester (A), which is essentially free of particles, and then mixing it with a vented twin-screw mixer.

[0325] Example 1

[0326] A mixture of polyesters (A) and (B) at 73% and 27% by mass, respectively, was fed into a vented twin-screw extruder, where it was melted and co-extruded at 285°C. The extruded material was then electrostatically bonded and cooled to solidify on cooling rollers with a surface temperature set at 22°C, yielding an unstretched sheet. Next, utilizing the difference in roller circumferential speed, the sheet was stretched longitudinally to 3.5 times its original length at a film temperature of 86°C, then fed into a tenter frame and stretched transversely to 3.6 times its original length at 120°C. After heat treatment at a main crystallization zone temperature of 230°C, the sheet was relaxed transversely by 3%, resulting in a biaxially stretched polyester film roll with a thickness of 75 μm.

[0327] Furthermore, the thickness (after drying) is 0.1 g / m. 2 The following release layer composition was applied in a specific manner and dried at 120°C for 30 seconds to obtain a release film roll. The properties of the release film are shown in Table 1 below.

[0328] <Mold Release Layer Composition>

[0329] Curing silicone resin (a silicone resin with vinyl groups introduced into the side chains and / or ends of the main chain formed by siloxane bonds, number average molecular weight: 10600, viscosity: 1.7 mcps. Methyl:vinyl = 98.9:1.1 (mol%)): 91% by mass)

[0330] Crosslinking agent (CL750: manufactured by Momentive Performance Materials Inc.): 3% by mass

[0331] Addition-type platinum catalyst (CM678: manufactured by Momentive Performance Materials Inc.): 6% by mass

[0332] The above release layer composition was diluted with n-heptane to adjust the solids concentration to 5.4% by mass.

[0333] Compositional analysis of the cured silicone resin was performed using 400MHz-NMR (Bruker Avance 400M).

[0334] 1 In the H-NMR determination, CDCl3 was used as the solvent, and the peak of the methyl group derived from dimethylsiloxane was used as the chemical shift reference. The determination was performed at a temperature of 30 °C.

[0335] Examples 2-4 and Comparative Example 1

[0336] In Example 1, the composition of the polyester film was changed to that shown in Table 1. The stretching temperature, stretch ratio, heat setting temperature, and relaxation rate were changed as shown in Table 1. Otherwise, the film was manufactured in the same manner as in Example 1 to obtain a release film roll. The properties of these films are shown in Table 1 below.

[0337] Example 5

[0338] A mixed raw material containing the aforementioned polyesters (A) and (B) at 70% and 30% by mass, respectively, was fed into a vented twin-screw extruder and melt-co-extruded at 285°C. The material was extruded from a nozzle, electrostatically bonded, and then cooled and cured on cooling rollers with a surface temperature set to 22°C to obtain an unstretched sheet. Next, utilizing the difference in roller circumferential speed, the film was stretched longitudinally to 3.4 times its original length at 88°C. The following release layer composition was then coated to a thickness (after drying) of 0.07 μm and fed into a tenter frame. The film was stretched transversely to 4.2 times its original length at 115°C, with the main crystallization zone temperature set to 245°C. After heat treatment, the film was relaxed transversely by 2% to obtain a release film roll with a thickness of 75 μm. The characteristics of the film are shown in Table 1 below.

[0339] (Mold release layer composition)

[0340] Main component: Vinyl-containing polydimethylsiloxane (vinyl content 0.16 mmol / g)

[0341] Crosslinking agent: Hydrogen-containing polydimethylsiloxane (Si-H group content 6.6 mmol / g)

[0342] (Si-CH3 group:Si-H group = 100:29)

[0343] Catalyst: A complex of chloroplatinic acid and vinylsiloxane

[0344] Main agent: Crosslinking agent = 95.2:4.8 (mass ratio)

[0345] Catalyst addition: 100 ppm (relative to organosilicon (main agent + crosslinking agent))

[0346] Comparative Example 2

[0347] In Example 5, as shown in Table 1, the release layer composition and film forming conditions were changed, but otherwise the same as in Example 5 was used to produce a release film roll with a thickness of 75 μm.

[0348] (Mold release layer composition)

[0349] A: Organosilicon containing polyether groups

[0350] The side chain of the dimethyl organosilicon contains: 100 parts dimethylsiloxane, 1 part polyethylene glycol (terminated with hydroxyl groups) with an 8-membered ethylene glycol chain, and a number average molecular weight of 7000 for a polyether-containing organosilicon (when the siloxane bond of the organosilicon is set to 1, the ether bond of the polyether group is 0.07 in molar ratio). The low molecular weight component with a number average molecular weight of less than 500 is 3%, and vinyl (vinylsilane) and hydrogen (hydrosilane) groups bonded to silicon are absent. It should be noted that this compound, by mass ratio, contains 1 part polyether-containing organosilicon, is mixed with sodium dodecylbenzenesulfonate in a 0.25 ratio, and dispersed in water for use in the formation of a release layer.

[0351] B: Melamine compound: Hexamethoxyhydroxymethyl melamine

[0352] C: Polyester resin

[0353] Aqueous dispersion of polyester resin comprising the following composition

[0354] Monomer composition: (Acid component) Terephthalic acid / isophthalic acid / sodium isophthalate-5-sulfonate / / (Diol component) Ethylene glycol / 1,4-butanediol / diethylene glycol = 56 / 40 / 4 / / 70 / 20 / 10 (mol ratio)

[0355] A:B:C = 20:30:50 (mass ratio)

[0356] The properties of the thin film are shown in Table 1 below.

[0357] [Table 1]

[0358] Table 1

[0359]

[0360] As can be seen from Examples 1 to 5, for the release film of the present invention, in order to depict the distribution curve of the surface roughness after appropriate roughening, when the release film is peeled off after being bonded to the adhesive layer, the shape of the surface of the release layer is transferred to the surface of the adhesive layer, the degassing index is small, and the time required for air leakage from the adhesive layer is short, so that the air is removed smoothly. In addition, from the viewpoint of the surface shape transfer rate of the release layer to the adhesive layer surface, it can be seen that the ratio of Sa of the adhesive layer surface to Sa of the release layer surface in Examples 1 to 5 is 0.9 or more, and the surface shape of the release layer is reproduced with good accuracy.

[0361] Furthermore, the substrate film constituting the release film has low birefringence, suggesting that the release film with adhesive layer has good cutability when cut into sheets.

[0362] On the other hand, Comparative Example 1 is a smooth, general-purpose release film, but it does not adequately transfer the embossing of the adhesive layer surface, showing a large degassing index value, suggesting that degassing is difficult when the sheet with the adhesive layer is bonded to the substrate.

[0363] Furthermore, the slope range of the roughness distribution curve in Comparative Example 2 exceeds the scope of this application, therefore, there is a high risk of particles detaching from the surface of the demolded film, which tends to reduce operability.

[0364] It should be noted that, Figures 1-3 The figures show top views of the release layer surface (“release surface”) of the release films (sample films) obtained in Examples 1-3. These figures also demonstrate that the roughness of the release layer surface of the release film of the present invention can be visually identified as different from the release layer surface (“release surface”) of the release film (sample film) of Comparative Example 1 (see Figure 1). Figure 4 ).

[0365] In addition, by Figures 5-7 It can be seen that the surface of the adhesive layer accurately reproduces the surface shape of the release layer.

[0366] Industrial availability

[0367] The release film of this invention can minimize moisture or bubble residue when bonded to the substrate by water sealing, while still being easy to cut into single sheets and film laminates, thus possessing high industrial value. It is particularly suitable for use as a protective film for automotive coatings or as a polishing film.

Claims

1. A release film for adhesive layer protection, wherein a release layer is provided on one side of a substrate film B, wherein the surface roughness of the release layer surface, i.e., the arithmetic mean height Sa, is 200 nm or more, the maximum peak height Sp is 300 nm or more, and the distribution curve representing the relationship between the protrusion height X and the number of protrusions Y on the surface of the release layer satisfies the following formula (1). The substrate film B contains 0.1-10% by mass of particles with an average particle size of 1-10 μm. -(logY2-logY1) / (X2-X1)≥1.0 (1) In the formula, Y1 and Y2 represent the number of protrusions on the surface of the release layer with protrusion heights of X1 = 0.98 μm and X2 = 1.98 μm, respectively, and the unit of the number of protrusions is units / mm. 2 .

2. The release film for adhesive layer protection according to claim 1, wherein, The substrate film B has a multilayer structure, and the surface layer of the substrate film B on the side in contact with the release layer contains 0.1 to 10% by mass of particles with an average particle size of 1 to 10 μm.

3. The release film for adhesive layer protection according to claim 1 or 2, wherein, The number of protrusions with a height of 0.98 μm shown in X1 is 1000 per mm. 2 above.

4. The release film for protecting the adhesive layer according to claim 1 or 2, wherein, The number of protrusions with a height of 1.98 μm or higher, as shown in X2, is 3 per mm. 2 above.

5. The release film for adhesive layer protection according to claim 1 or 2, wherein, The release layer contains a curable silicone resin.

6. The release film for protecting the adhesive layer according to claim 5, wherein, The release layer also contains a surfactant.

7. The release film for adhesive layer protection according to claim 1 or 2, wherein, The substrate film B is a polyester film.

8. The release film for adhesive layer protection according to claim 7, wherein, The birefringence of the polyester film is Δn×10 3 The value is calculated to be below 25.

9. The release film for adhesive layer protection according to claim 7, wherein, The molecular orientation degree, i.e., the MOR value, of the polyester film is below 1.

5.

10. The release film for adhesive layer protection according to claim 1 or 2, wherein the degassing index is 2000 seconds or less. The release film was cut into 70mm square pieces. The release film was then laminated with a polyester film having a 5mm diameter hole in the center, with the surface of the release layer of the release film in contact with the polyester film. The degassing index was then measured. The degassing index is determined as follows: using a Digi-Bekk smoothness tester, in an atmosphere of 23°C and 50%RH, the pressure of the pressurizing device is 100 kPa and the vacuum container is a small vacuum container with a volume of 38 ml. The time it takes for 1 mL of air to flow through the container, i.e., the time it takes for the pressure inside the container to change from 50.7 kPa to 48.0 kPa, is measured in seconds. Ten times the number of seconds obtained is taken as the degassing index.

11. The release film for adhesive layer protection according to claim 7, wherein, The polyester film contains more than 50% by mass of recycled raw materials.

12. A film laminate having a substrate film A on the release layer of the release film according to any one of claims 1 to 11, separated by an adhesive layer.

13. The thin film laminate according to claim 12, wherein, The substrate film A is a polyurethane film.

14. The thin film laminate according to claim 12, wherein, The substrate film A is a resin film with a printed layer.

15. The thin film laminate according to any one of claims 12 to 14, wherein, The adhesive layer is any one of acrylic adhesive layer, urethane adhesive layer, or silicone adhesive layer.

16. The thin film laminate according to any one of claims 12 to 14, wherein, The surface roughness of the adhesive layer after the release film is peeled off, i.e., the arithmetic mean height Sa, is above 200 nm.

17. The thin film laminate according to any one of claims 12 to 14, wherein, The elastic modulus of the adhesive layer at 25°C is above 20 MPa.

18. A method for manufacturing a release film for adhesive layer protection according to any one of claims 1 to 11, wherein, The substrate film B is a multilayer film, which has a polyester layer containing particles only on the surface. The polyester layer in contact with the release layer contains particles with an average particle size of 1.0 to 4.5 μm. The amount of these particles added is 1 to 10% by mass, and the difference between the longitudinal stretch ratio and the transverse stretch ratio is within 0.2 times.

19. The method for manufacturing a release film for adhesive layer protection according to claim 18, wherein, The longitudinal stretch ratio is 3.4 to 3.8 times, and the transverse stretch ratio is 3.5 to 4 times.

20. The release film for adhesive layer protection according to claim 1 or 2, which is for use as a protective film for automotive coatings or for polishing.

21. The film laminate according to any one of claims 12 to 14, which is for use as a protective film for automotive coatings or for polishing films.

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