KR20230159711A - release film - Google Patents

Abstract

[Problem] To provide a release film that has light peeling force both before and after heating, can also have light peeling force even when peeled at high speed, and does not substantially contain silicone.
[Solution] A release film comprising a base film and a release layer, wherein the release layer includes at least an acrylic resin (A), a crosslinking agent (B), and a release agent (C), and the acrylic resin (A) is a specific It includes at least an A-1 component represented by the formula (Formula 1) and an A-2 component represented by the formula (Formula 2), the release layer does not substantially contain a silicone component, and the release layer is laminated on the base film. It is a release film in which the ratio a/b of the mass (a) of the acrylic resin (A) contained in the release layer and the mass (b) of the crosslinking agent (B) satisfies the formula (Ⅰ):
(Ⅰ) 0.1≤a/b≤8.0.
In formula (1) in the specification, R ₁ represents (C _n H _2n+1 ) (n = an integer of 8 or more and 20 or less), and R ₄ represents H or CH ₃ .
In formula (2) in the specification, R ₂ represents (C _m H _2m OH) (m = an integer of 1 to 10) or H, and R ₄ represents H or CH ₃ .

Description

release film

The present invention relates to release films.

Release films, which are made by laminating a release layer on a base material such as a polyethylene film, are structural members for batteries, adhesive layer protection (protection for OCA (Optical Clear Adhesive), protection for adhesive tapes, etc.), and transdermal absorption in the medical field. It is used for a wide range of purposes, such as process paper used in the manufacturing process of electronic components such as mold and adhesive separators and ceramic capacitors, and protection of image display members. To give a specific example, an adhesive sheet is composed of a base material and an adhesive layer, and is used as a film for the manufacturing process of electronic components and the like. Before the adhesive sheet is used as a process film, it is affixed to a release film. A release agent layer is provided on the surface of this release film (contact surface with the adhesive layer) for the purpose of improving release properties. Constituent materials of this mold release agent layer include silicone-based mold release agents, fluorine-based mold release agents, and long-chain alkyl-type mold release agents.

Silicone-based mold release agents have excellent release properties. However, the silicon component is easily transferred to the release object, and there are problems such as malfunction of electronic devices due to contamination by silicon, making use in electronic components difficult. Fluorine-based mold release agents have excellent release properties and heat resistance. However, it has the problem of being expensive and having poor wettability. Long-chain alkyl-based mold release agents have superior wettability than silicone-based mold release agents and fluorine-based mold release agents. However, it does not necessarily have sufficient release properties.

Patent Document 1 (Japanese Patent Laid-Open No. 2010-144046) discloses a release agent that prevents cissing when applying an adhesive resin to a release agent and can maintain good peeling performance from the adhesive resin film, ( A) a poly(meth)acrylate containing an alkyl group or aryl group terminal mono or polyalkylene glycol (meth)acrylate unit, and (B) an alkyl (meth)acrylate unit having an alkyl group having 1 to 30 carbon atoms. A release agent including (as the main agent) is disclosed.

Patent Document 2 (Japanese Patent Application Laid-Open No. 2007-002092) discloses at least alkyl (meth)acrylate and hydroxyalkyl (meth)acrylate as release agents that have lighter peelability than silicone resin release agents and do not transfer. A release agent containing an active ingredient obtained by crosslinking a tentatively copolymerized prepolymer with an isocyanate group-containing compound is disclosed.

Patent Document 3 (Japanese Patent Application Laid-Open No. 2014-151481) discloses a release polyester film with little deterioration of release property due to heat during processing, which contains a release agent and an activated methylene block isocyanate compound applied to at least one side of the polyester film. A laminated polyester film characterized by having an application layer formed from a liquid is disclosed.

Japanese Patent Laid-Open No. 2010-144046 Japanese Patent Laid-Open No. 2007-002092 Japanese Patent Laid-Open No. 2014-151481

However, in the technology of Patent Document 1, the peeling force is large, and a release agent with a lighter peeling force is required.

Additionally, in the technology of Patent Document 2, there is a problem that the wettability of the mold release agent is insufficient. In the technology of Patent Document 3, there is a problem in that the peeling force after heating is heavy and suppression of an increase in the peeling force by heating is insufficient.

Additionally, in the manufacturing process of electronic components and the like, heat or pressure may be applied to the release film, and in that case, the long-chain alkyl-based release agent tends to have an increased peeling force after heating. Additionally, in the manufacturing process of required products, high-speed peeling is required to increase productivity. However, when peeling at high speed, especially when peeling at high speed after heating, the peeling force tends to increase. Furthermore, even if peeling is possible, there is a risk that cohesive failure may occur in the release layer and the release layer components may be transferred to the release object.

In this way, long-chain alkyl-based mold release agents have a problem in that they cannot sufficiently exhibit performance as mold release agents, and their improvement is required.

The present invention solves the above problems and, for example, has a light peeling force both before and after heating, can also have a light peeling force even when peeled at high speed, and has a material that does not substantially contain silicon. A release film is provided.

As a result of intensive studies to solve the above problems, the present inventors have found that the above object can be achieved by a release film having the following structure, and have completed the present invention.

That is, the present invention consists of the following configuration.

[1] A release film having a base film and a release layer in this order,

The release layer includes at least an acrylic resin (A), a crosslinking agent (B), and a release agent (C),

The acrylic resin (A) contains at least an A-1 component represented by the following formula (1) and an A-2 component represented by (2),

The release layer does not substantially contain a silicone component and is a release film in which the release layer is laminated on a base film,

A release film characterized in that the ratio a/b of the mass (a) of the acrylic resin (A) contained in the release layer and the mass (b) of the crosslinking agent (B) satisfies the formula (Ⅰ)

(Ⅰ) 0.1≤a/b≤8.0

In formula (1), R ₁ represents (C _n H _2n+1 ) (n = an integer from 8 to 20), and R ₄ represents H or CH ₃ .

In formula (2), R ₂ represents (C _m H _2m OH) (m = integer from 1 to 10) or H, and R ₄ represents H or CH ₃ .

[2] In one aspect, the release layer in the release film of the present invention further contains a release agent (C), and the mass (b) of the crosslinking agent contained in the release layer and the mass (c) of the release agent are The ratio c/b satisfies equation (II).

(Ⅱ) 0.1≤c/b≤12.0

[3] In one embodiment, when the total mass of the A-1 component and the A-2 component of the acrylic resin (A) in the release layer is 100 parts by mass, the mass of A-1 exceeds 50 parts by mass. .

[4] In one aspect, the release agent (C) does not contain an acrylic group and also contains at least a long-chain alkyl group and a reactive functional group that does not contain silicone.

[5] In one aspect, the release film of the present invention has a normal peel force (PF1) of 500 mN/50 mm or less at a peel speed of 0.3 m/min.

[6] In one aspect, the release film of the present invention has a peeling force (PF2) after heating (70°C, 20h) at a peeling speed of 0.3 m/min that is twice the above-mentioned peeling force (PF1). It is as follows.

[7] In one aspect, the release film of the present invention has a peel force (PF3) after heating (70°C, 20 h) at a peel speed of 30 m/min that is 30 times or less than the above-mentioned as-state peel force (PF1). am.

[8] In another aspect of the present invention, a laminated film is provided in which an adhesive layer is laminated on at least one side of the release film of the present invention.

According to the present invention, it is possible to provide a release layer film that has light peelability both before and after heating and maintains light release property even when peeled at high speed.

As a result of intensive study, the inventors have found that the present invention is a release film comprising a base film and a release layer,

The release layer includes at least an acrylic resin (A), a crosslinking agent (B), and a release agent (C),

The acrylic resin (A) contains at least an A-1 component represented by the following formula (1) and an A-2 component represented by (2),

The release layer does not substantially contain a silicone component and is a release film in which the release layer is laminated on a base film,

It relates to a release film wherein the ratio a/b of the mass (a) of the acrylic resin (A) and the mass (b) of the crosslinking agent (B) contained in the release layer satisfies the formula (I).

(Ⅰ) 0.1 ≤a/b≤8.0

In formula (1), R ₁ represents (C _n H _2n+1) (n=8 to 20 integer), and R ₄ represents H or CH ₃ .

In formula (2), R ₂ represents (C _m H _2m OH) (m = integer from 1 to 10) or H, and R ₄ represents H or CH ₃ .

(Base film)

The release film in the present invention includes a base material and a release layer disposed on the surface of the base material. When the mold release object is placed on the release layer of the release film, the mold release object can be molded into the same shape as the base material. Additionally, since the release layer and the mold release body are easily separated, the shape of the mold release body can be transformed and maintained into a desired shape. The release layer may be disposed on one side of the surface of the substrate, or may be disposed on both sides.

As the base material, a known base material can be used. For example, as a base material, a resin film formed of polyester such as polyethylene terephthalate and polyethylene naphthalate, polyolefin such as polypropylene, polyimide, etc. can be used. In particular, from the viewpoint of cost and productivity, polyester film is preferable, and polyethylene terephthalate film is more preferable.

The thickness of the base material is preferably 10 μm or more and 188 μm or less, and more preferably 25 μm or more and 100 μm or less. By having a thickness of the base material of 10 μm or more, deformation due to heat can be suppressed during base material production, processing, and molding. On the other hand, if the thickness of the substrate is 188 μm or less, the physical properties required for the substrate can be satisfied while the amount of substrate discarded after use can be suppressed, thereby reducing the burden on the environment.

An easily adhesive coat may be disposed between the base material and the release layer to improve adhesiveness. Additionally, a coat for imparting release activity, heat resistance, antistatic properties, etc. may be disposed on the surface opposite to the surface of the substrate on which the release layer is disposed.

The area average surface roughness (Sa) of the surface on which the release layer of the base film used in the present invention is laminated is preferably in the range of 1 to 50 nm, more preferably 2 to 30 nm. The maximum protrusion height (P) of the surface on which the release layer of the base film used in the present invention is laminated is preferably 2 μm or less, and more preferably 1.5 μm or less. When Sa is 50 nm or less and P is 2 ㎛ or less, the thickness unevenness of the release layer can be suppressed and the smoothness of the surface of the mold release layer can be kept constant, and further, the thickness unevenness of the mold release body can be reduced, When peeled from the release film, the possibility of tearing starting from the thin part can be suppressed.

The surface average roughness (Sa) of the area opposite to the surface on which the release layer of the base film used in the present invention is laminated is preferably in the range of 10 to 100 nm, more preferably 2 to 30 nm. The maximum protrusion height (P) opposite to the surface on which the release layer of the base film used in the present invention is laminated is preferably 2 μm or less, and more preferably 1.5 μm or less. When Sa is 10 nm or more, the slipperiness of the release surface and anti-release surface improves, and the winding property is excellent. Moreover, if P is 2 micrometers or less, when winding up, no damage will be done to the surface of the release layer, and the possibility that a part of the release layer will peel off will be reduced. Additionally, when the release object is peeled from the release film, the possibility of tearing starting from the part where the release layer was peeled off can be suppressed.

The haze of the base film used in the present invention is preferably 10% or less, more preferably 5% or less, and even more preferably 3% or less. If the haze is 10% or less, external appearance inspection is easy when a release film or an adhesive layer, etc. are processed on the release film.

The base film in the present invention can use recycled raw materials from polyester film scraps and PET bottles. In the present invention, since recycled raw materials such as film scraps and PET bottles can be used, the environmental load can be greatly reduced. Moreover, even in an embodiment containing recycled raw materials from film scraps and PET bottles, improvement in the slipperiness of the film and ease of removal of air can be maintained. The release layer of the present invention can appropriately recover, process, and reuse polyester films used in various applications.

When containing such recycled raw materials (materials), the surface average roughness (Sa) of the surface on which the release layer of the base film is laminated may contain fine particles of a size within the range of 1 to 50 nm, and the base film may also contain fine particles. It may contain fine particles of a size such that the maximum protrusion height (P) of the surface on which the release layer is laminated is 2 μm or less.

For example, in the base material of the present invention, the size of the fine particles may be in the range of (0.001 μm or more to 10 μm). If the fine particles have a size within this range, the area average surface roughness (Sa) and maximum protrusion height (P) of the surface on which the release layer of the base film is laminated can be satisfied.

In one aspect, the substrate may have a surface layer substantially free of inorganic particles, and a release layer may be laminated on this surface layer.

(Heterogeneous layer)

The release layer in the present invention is a release layer that contains at least an acrylic resin (A), a crosslinking agent (B), and a release agent (C), and does not substantially contain a silicone component. For example, a release layer can be formed by curing a release layer forming composition containing an acrylic resin (A), a crosslinking agent (B), and a release agent (C).

(acrylic resin)

The release layer of the present invention contains acrylic resin (A).

Moreover, it is preferable that the acrylic resin (A) contained in the release layer of this invention has a long-chain alkyl group. Although it cannot be analyzed theoretically, as a result of repeated experiments, it is thought that the acrylic resin (A) has a long-chain alkyl group, so that the release agent described later can be efficiently oriented on the surface of the release layer. In particular, the acrylic resin (A) according to the present invention can exhibit good wettability for, for example, an adhesive composition that forms an adhesive. In addition, the acrylic resin (A) according to the present invention has light peelability against a release material such as an adhesive formed on the release layer both before and after heating, and also maintains light release property even when peeled at high speed. can be provided.

In this way, the acrylic resin (A) can contribute to release properties in addition to its function as a binder in the release layer. For example, the molecular weight of the acrylic resin (A) is preferably over 500.

The acrylic resin of the present invention may further include a methacrylic resin, for example, a polymer of methyl methacrylate (methyl methacrylate = MMA), or a copolymer with acrylic acid ester (acrylate).

In addition, in the present invention, before heating means conditions of a temperature of 22°C and 60% humidity, and after heating means a state after heating for 20 hours under conditions of a temperature of 70°C. In addition, in the present invention, after heating may be not only immediately after heating, but may also be in a state of cooling to ambient temperature or lower (for example, 40°C or lower).

Moreover, the release layer according to the present invention contains an acrylic resin (A) and does not substantially contain a silicone component. For this reason, it is possible to suppress the transfer of the silicone component to the release body, so for example, it is possible to prevent the release body from being contaminated by silicone, and for example, malfunction of electronic devices due to the release body can be avoided. can do. In this specification, “substantially does not contain a silicone component” means that a silicone component is not intentionally added among the components that form the release layer. For example, in the manufacturing process of the release layer, etc., there is a possibility that very little silicone composition, etc. that may be unexpectedly present may be included. In consideration of such actual conditions, it is preferable that the amount of the silicone component contained in the release layer is less than 0.1 parts by mass with respect to 100 parts by mass of the release layer.

The acrylic resin (A) may be, for example, an acrylic polymer copolymerized with a long-chain alkyl acrylate, a graft polymer grafted with a long-chain alkyl, a block polymer with a long-chain alkyl added to the terminal, etc.

The acrylic resin (A) is preferably formed by crosslinking a polymer containing at least the A-1 component represented by the following formula (1) and the A-2 component represented by the following formula (2).

In formula (1), R ₁ represents (C _n H _2n+1 ) (n = an integer from 8 to 20), and R ₄ represents H or CH ₃ .

In formula (2), R ₂ represents (C _m H _2m OH) (m = integer from 1 to 10) or H, and R ₄ represents H or CH ₃ .

When the total mass of the A-1 component and the A-2 component of the acrylic resin (A) in the release layer is 100 parts by mass, it is preferable that the mass of A-1 exceeds 50 parts by mass. It is preferable that the mass of A-1 exceeds 50 parts by mass because the peelability of the mold release layer tends to become lighter. The mass of A-1 is preferably over 70 parts by mass, more preferably over 80 parts by mass, and most preferably over 90 parts by mass.

For example, the mass of A-1 may be 99 parts by mass or less, may be 96 parts by mass or less, and may be 92 parts by mass or less. In one aspect, the mass of A-1 may be 85 parts by mass or less.

When the amount of component A-1 is within the above range, the physical properties of the release layer can be maintained even before and after heating.

For this reason, the effect of the release layer according to the present invention, for example, the feature of having light peelability both before and after heating and maintaining light release property even when peeled at high speed, can be exhibited more efficiently.

In addition, in the present invention, since the amount of component A-1 is within the above range, even when the release film of the present invention is stored for, for example, several days to several months after heating, the acrylic resin before heating ( The release film can be stored without significantly deteriorating the physical properties of A).

In formula (1) representing the A-1 component, R ₁ is an alkyl group having n of 8 to 20 carbon atoms. When the carbon number n is 8 or more, the A-1 component can exhibit good release properties and can suppress the adhesiveness of the release layer, which may be caused by an alkyl group with a small number of carbon atoms. On the other hand, if the carbon number n is 20 or less, the flexibility of component A-1 can be maintained, and the wettability of the film surface of the release layer can be sufficiently secured. Carbon number n is preferably 10 to 18, and more preferably 12 to 16. Additionally, R ₁ may be either linear or branched. If R ₁ is linear, it is preferable because the peelability of the release layer tends to become lighter.

In formula (1) representing the A-1 component, R ₄ is H or CH ₃ , either of which is suitable. As a raw material for component A-1, a monomer represented by the following formula (7) can be used.

In formula (7), R ₁ represents (C _n H _2n+1 ) (n = an integer of 8 or more and 20 or less), and R ₄ represents H or CH ₃ .

As a raw material for component A-1, specifically, lauryl (meth)acrylate, stearyl (meth)acrylate, etc. can be used.

In R ₂ of formula (2) representing the A-2 component, the number of carbon atoms m is 1 or more and 10 or less. If the carbon number m is 10 or less, it is possible to avoid the crosslinking density of the release layer of the present invention from becoming coarse, the cohesive force of the release layer itself can be suppressed from weakening, and the peeling force from becoming heavy can be suppressed. there is. The number of carbon atoms m is preferably 2 to 8, and more preferably 2 to 4.

In formula (2) representing the A-2 component, R ₄ is H or CH ₃ , and either is suitable. As a raw material for component A-2, a monomer represented by the following formula (8) can be used.

In formula (8), R ₂ represents (C _m H _2m OH) (m = integer from 1 to 10) or H, and R ₄ represents H or CH ₃ .

As raw materials for component A-2, specifically, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, hydroxybutyl (meth)acrylate, etc. can be used.

(Cross-linking agent)

As the crosslinking agent (B) used in forming the release layer of the present invention, polyisocyanate, melamine, epoxy, aluminum chelate, titanium chelate, ultraviolet curable resin, or a mixture of two or more types thereof can be used. Among them, the use of melamine is preferable because the cured film is rigid and has excellent chemical resistance and weather resistance. Crosslinking with aluminum chelate or titanium chelate may not contain metal components depending on the application.

In the present invention, the ratio a/b of the mass (a) of the acrylic resin contained in the release layer and the mass (b) of the crosslinking agent satisfies the formula (I).

(Ⅰ) 0.1≤a/b≤8.0

In one aspect, the ratio a/b of the mass (a) of the acrylic resin and the mass (b) of the crosslinking agent is 0.2 or more and 5.0 or less, for example, 0.2 or more and 4.0 or less, and may be 0.2 or more and 2.5 or less. When the ratio a/b of the mass of the acrylic resin (a) and the mass of the crosslinking agent (b) is within the above range, the acrylic resin (A) and the acrylic resin (A) additionally added as needed are crosslinked by the crosslinking agent, Since the elastic modulus of the release layer is improved, the peeling force can be further lightened. Moreover, since the release component of the acrylic resin (A) oriented on the surface of the release layer is fixed by the crosslinking agent even after heating, the increase in peeling force after heating is suppressed. If the ratio a/b of the mass (a) of the acrylic resin and the mass (b) of the crosslinking agent is 0.1 or less, the release component of the acrylic resin (A) present on the surface of the release layer decreases, for example, In an embodiment where an adhesive is used for the mold, the peeling force may become heavy.

Moreover, if the ratio a/b of the mass of the acrylic resin (a) and the mass of the crosslinking agent (b) is 8.0 or more, the crosslinking agent will be less, so the acrylic resin (A) will not be sufficiently crosslinked, and the release layer strength will not be sufficient. There is concern that the peeling force may increase. Additionally, this problem tends to become more noticeable when peeling occurs at high speed.

The melamine-based compound used in the release layer in the present invention can be any general compound and is not particularly limited, but is obtained by condensing melamine and formaldehyde, and contains a triazine ring, a methylol group, and/or an alkoxymethyl group in one molecule. It is desirable to have at least one of each. Specifically, a methylol melamine derivative obtained by condensing melamine and formaldehyde is preferably etherified by dehydration condensation reaction of methyl alcohol, ethyl alcohol, isopropyl alcohol, butyl alcohol, etc. as lower alcohols. Examples of methylolated melamine derivatives include monomethylol melamine, dimethylol melamine, trimethylol melamine, tetramethylol melamine, pentamethylol melamine, and hexamethylol melamine. It does not matter whether you use one type or two or more types.

The melamine used in the present invention can also be commercially available. For example, Cymel 300, Cymel 301, Cymel 303LF, Cymel 350, Cymel 370N, Cymel 771, Cymel 325, Cymel 327, Cymel 703, Cymel 712, Cymel 701, Cymel 266, Cymel 267, Cymel 285, Cymel 232, Cymel 235, Cymel 236, Cymel 238, Cymel 272, Cymel 212, Cymel 253, Cymel 254, Cymel 202, Cymel 207( (manufactured by Allnex Japan Co., Ltd.), Nikalak MW-30M, Nikalak MW-30, Nikalak MW-30HM, Nikalak MW-390, Nikalak MW-100LM, Nikalok MA-1-750LM, Nikalok MW -22, Nikalak MS-21, Nikalak MS-11, Nikalak MW-24A-1, Nikalak MS-001, Nikalak MA-1-002, Nikalak MA-1-730, Nikalak MA-1 -750, Nikalac MA-1-708, Nikalac MA-1-706, Nikalac MA-1-042, Nikalac MA-1-035, Nikalac MA-1-45, Nikalac MA-1-43 , Nikalak MA-1-417, Nikalak MA-1-410 (manufactured by Nippon Carbide Co., Ltd.), etc. Among these, full ether type methylated melamine resin is preferable in terms of curability at low temperature and short time and adhesion to the polyester film. Commercially available products include Cymel 303LF and Nikalak MW-30.

It is preferable to add an acid catalyst to the release layer in the present invention in order to promote the crosslinking reaction of the melamine-based compound, and it is preferable to add an acid catalyst to the composition for forming a release layer, apply it, and cure it. The acid catalyst used is not particularly limited and existing acid catalysts can be used, but it is preferable to use a sulfonic acid-based catalyst.

As the sulfonic acid-based catalyst, for example, p-toluenesulfonic acid, xylenesulfonic acid, cumenesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenesulfonic acid, trifluoromethanesulfonic acid, etc. can be suitably used. However, from the viewpoint of reactivity, p- Toluenesulfonic acid can be used particularly suitably.

Sulfonic acid-based catalysts have high acidity and excellent reactivity compared to other acid catalysts such as carboxylic acid-based catalysts, so the release layer can be processed at a lower temperature. Therefore, it is preferable because it can suppress the deterioration of the flatness of the film and the deterioration of the rolled appearance due to heat during processing.

The sulfonic acid-based catalyst used in the present invention may be a commercially available catalyst. Examples of commercial products include Dryer (registered trademark) 900 (p-toluenesulfonic acid, manufactured by Hitachi Chemical Industries, Ltd.), NACURE (registered trademark) DNNDSA series (dinonylnaphthalene disulfonic acid, manufactured by Kusumoto Chemical Industries, Ltd.), and DNNSA series (Dinonyl). Naphthalene (mono)sulfonic acid, manufactured by Kusumoto Kasei Co., Ltd.), DDBSA series (dodecylbenzenesulfonic acid, manufactured by Kusumoto Kasei Co., Ltd.), p-TSA series (p-toluenesulfonic acid, manufactured by Kusumoto Kasei Co., Ltd.) etc. can be mentioned.

(Lee Hyeong-je)

In one aspect, the release layer further contains a release agent (C). The mold release agent (C) preferably contains a reactive functional group. Although it cannot be interpreted theoretically, repeated experiments have shown that the added release agent (C) crosslinks with the acrylic resin (A) present near the surface of the release layer, and the long-chain alkyl component near the surface of the release layer forms a bond with the acrylic resin. Compared to the case of (A) alone, it is thought that it is possible to reduce the peeling force by being dense. In addition, since the release agent (C) is crosslinked even after heating, it can remain on the surface of the release layer, so it is thought that an increase in peeling force can be suppressed even after heating.

The mold release agent used in the present invention is preferably a compound containing a long-chain alkyl group and a reactive functional group that does not contain an acrylic group and does not contain silicone, and a low-molecular-weight polyolefin wax, a long-chain alkyl-based additive, a higher alcohol, etc. are preferable. These structures may be linear or crushed. Among these, two or more types of materials may be mixed and used.

The mold release agent used in the present invention preferably has a low molecular weight, and the molecular weight is preferably 100 to 500. By keeping the molecular weight of the release agent within the above range, it can be easily oriented on the surface of the release layer, making it possible to reduce the peeling force. On the other hand, if the molecular weight is 100 or more, the release property of the mold release agent can be exhibited, and the risk of exhibiting stickiness can be suppressed. In addition, if the molecular weight is 500 or less, the solubility of the release agent can be suppressed from decreasing, the flatness of the surface of the release film can be suppressed, and the risk of the appearance of the obtained mold release being damaged can be reduced.

(Low molecular weight polyolefin wax)

As the low molecular weight polyolefin wax, for example, low molecular weight ones such as polyethylene wax and polypropylene wax can be used.

(Long-chain alkyl additive)

As the long-chain alkyl-based additive, one other than the acrylic resin (A) can be added. For example, low molecular weight additives having an alkyl chain, such as Pyroyl 1010 or Pyroyl 1010S (both manufactured by Ipposha Yushi Kogyo Co., Ltd.), can be used as appropriate. The above-mentioned mold release additive is added in a timely manner in an amount capable of producing a predetermined mold release property.

(higher alcohol)

Higher alcohols include linear higher alcohols such as octanol, nonanol, decanol, undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol, cetanol, heptadecanol, stearyl alcohol, Eicosanol, docosanol, etc. can be mentioned.

The carbon number of the higher alcohol is preferably 8 to 24. When the number of carbon atoms is 8 or more, the release layer exhibits good release properties. A carbon number of 24 or less is preferable because it has good solubility in solvents and is unlikely to damage the appearance of the coating film.

In one aspect, the ratio c/b of the mass (b) of the crosslinking agent contained in the release layer and the mass (c) of the release agent satisfies the formula (II).

(Ⅱ) 0.1≤c/b≤12.0

For example, the amount of the release agent added in the present invention is preferably such that the ratio c/b of the mass (b) of the crosslinking agent and the mass (c) of the release agent is 7.0 or less, for example, 5.0 or less. Additionally, the ratio c/b may be 0.15 or more.

By adjusting the ratio (c/b) of the release agent/crosslinking agent to this range, the release agent component segregates to the surface of the release layer, thereby lightening the peeling force. In addition, since the release agent component oriented on the surface of the release layer is fixed by the crosslinking agent even after heating, the increase in peeling force after heating and high-speed peeling force after heating is suppressed.

On the other hand, if the ratio of release agent/crosslinking agent is 12.0 or more, since there is little crosslinking agent, there is a possibility that the release component may not be able to remain on the surface layer of the release layer when heated, and the peeling force after heating may become heavy.

Although the interpretation should not be limited to a specific theory, by using the release agent (C) in combination with the acrylic resin (A) according to the present invention, it is possible to maintain sufficient film strength so that the release agent (C) does not peel off from the surface of the release layer. It can have release properties.

In one aspect, the ratio a/c of the mass (a) of the acrylic resin contained in the release layer and the mass (c) of the release agent satisfies the formula (III).

(Ⅲ) 0.1≤a/c≤7.0

For example, as the amount of the release agent added in the present invention, the ratio a/c of the mass (a) of the acrylic resin and the mass (c) of the release agent is preferably 5.0 or less, more preferably 3.0 or less, and 2.0 or less. It is most desirable. Moreover, the ratio a/c is preferably 0.3 or more, more preferably 0.5 or more, and most preferably 0.7 or more.

By adjusting the acrylic resin/mold release agent (a/c) to this range, the release agent component segregates to the surface of the release layer, thereby lightening the peeling force. In addition, since the release agent component oriented on the surface of the release layer is fixed by the crosslinking agent even after heating, the increase in peeling force after heating and high-speed peeling force after heating is suppressed.

If the ratio of acrylic resin/mold release agent (a/c) is 0.1 or less, it is not preferable because there is too much release agent, excessive segregation of the release agent occurs on the surface of the release layer, and a film of sufficient hardness cannot be obtained.

Although the interpretation should not be limited to a specific theory, by using the release agent (C) in combination with the acrylic resin (A) according to the present invention, it is possible to maintain sufficient film strength so that the release agent (C) does not peel off from the surface of the release layer. It can be provided with release properties.

Additives such as adhesion improvers and antistatic agents may be added to the release layer of the present invention as long as they do not impair the effects of the present invention. Additionally, in order to improve adhesion to the substrate, it is also desirable to pre-treat the surface of the polyester film, such as anchor coat, corona treatment, plasma treatment, or atmospheric pressure plasma treatment, before installing the release coating layer.

The thickness of the release layer is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.05 μm or more and 1 μm or less. When the thickness of the release layer is less than 0.01 μm, it is difficult to uniformly mold the release layer, and there is a risk that the peeling force may become unstable. On the other hand, if the thickness of the release layer exceeds 10 μm, it is not preferable because the use ratio of recycled raw materials is lowered and it is not economical.

The regional surface average roughness (Sa) of the release layer is preferably in the range of 1 to 50 nm, more preferably 2 to 30 nm. The maximum protrusion height (P) of the surface on which the release layer of the base film used in the present invention is laminated is preferably 2 μm or less, and more preferably 1.5 μm or less. When Sa is 50 nm or less and P is 2 ㎛ or less, uneven thickness of the release layer can be suppressed and the smoothness of the surface of the release layer can be kept constant, so that when the release body is peeled from the release film, the thinner part starts. This can reduce the possibility of tearing.

In addition, the change rate of the surface average roughness (Sa) and maximum protrusion height (P) of this area before and after heating is preferably within 20%, more preferably within 10%, and even more preferably within 5%. If the change rate of the area surface average roughness (Sa) or maximum protrusion height (P) before and after heating is within 20%, the adhesive area between the mold release layer and the mold release object increases after heating, and the mold release object is separated from the mold release layer by the anchor effect. This is preferable because the possibility of heavy peeling during peeling is low.

In the present invention, the method of forming the release coating layer is not particularly limited, and a coating liquid in which a release resin is dissolved or dispersed is spread by applying it to one side of a polyester film as a substrate, and then dissolving in a solvent. After removing the material by drying, heat drying, heat curing, or ultraviolet curing is used. At this time, the drying temperature during solvent drying and heat curing is preferably 180°C or lower, more preferably 160°C or lower, and most preferably 140°C or lower. The heating time is preferably 30 seconds or less, more preferably 20 seconds or less, and even more preferably 10 seconds or less. When it is 180°C or lower, the flatness of the film is maintained and there is little risk of uneven thickness of the release layer, so it is preferable. If it is 140°C or lower, processing can be done without damaging the flatness of the film, and the risk of uneven thickness of the release layer is further reduced, so it is particularly preferable.

In the present invention, the coating liquid for applying the release coating layer is not particularly limited, but it is preferable to add a solvent having a boiling point of 70°C or higher. By adding a solvent with a boiling point of 70°C or higher, the coating film can be leveled by preventing boiling during drying, and the flatness of the coating film surface after drying can be improved. The addition amount is preferably about 50 to 99% by mass relative to the entire coating liquid.

As the application method of the coating liquid, any known application method can be applied, for example, roll coating methods such as gravure coating or reverse coating, bar coating methods such as wire bars, die coating, or spray coating. Conventionally known methods such as method and air knife coating method can be used.

The release film obtained in the present invention preferably falls within the ranges shown below with respect to the peeling force as-is, the peeling force after heating, and the peeling force during high-speed peeling after heating.

The release film obtained in the present invention may have a normal peeling force (PF1) of 1000 mN/50 mm or less at a peeling speed of 0.3 m/min, for example, 600 mN/50 mm or less, and may be 500 mN/50 mm or less. Although the interpretation should not be limited to a specific theory, in the present invention, in addition to the feature that the release layer does not substantially contain a silicone component, in particular, the A-1 component and A- of the acrylic resin (A) in the release layer When the total mass of the two components is 100 parts by mass, such light peelability can be induced by the mass of A-1 exceeding 50 parts by mass.

In one aspect, the release film obtained in the invention has a normal peeling force (PF1) of 50 mN/50 mm or more at a peeling speed of 0.3 m/min, for example, 80 mN/50 mm or more.

If it is within the above range, it is preferable because the peeling force is light. In particular, it is preferable that the normal peeling force is 50 mN/50 mm or more and 1000 mN/50 mm or less because the possibility of the mold release material being peeled off during the conveyance process is low. It is preferable that the peeling force before heating is 1000 mN/50 mm or less, especially 500 mN/50 mm or less, because there is a low possibility that the mold release object will be deformed when the mold release object is peeled.

The normal peeling force means the normal peeling force at a peeling speed of 0.3 m/min. The release material disposed on the release layer according to the present invention, for example, an adhesive (as an example, an acrylic adhesive tape (Nitto Den) The peeling force can be evaluated when peeling off No. 31B), manufactured by Kosa, etc.). In addition, the measurement of the normal peeling force can be performed under conditions of room temperature (25°C). The same release body can be applied for the peeling force after heating below.

In one aspect, the peeling force (PF2) after heating (70°C, 20h) at a peeling speed of 0.3 m/min. is two times or less than the normal peeling force (PF1). It is preferable that the peel force after heating (PF2) is 2 times or less than the normal peel force because the peel force after heating is low. The peeling force after heating (PF2) is more preferably 1.9 times or less, and most preferably 1.8 times or less, than the normal peeling force (PF1). It is preferable that the peeling force after heating is two times or less than the normal peeling force because the mold release object is not deformed when the mold release object is peeled off after heating.

Although the interpretation should not be limited to a specific theory, in the present invention, in addition to the feature that the release layer does not substantially contain a silicone component, in particular, the A-1 component and A- of the acrylic resin (A) in the release layer When the total mass of the two components is 100 parts by mass, the mass of A-1 exceeds 50 parts by mass, so that light peelability before and after heating can be maintained.

In one aspect, the peeling force (PF3) after heating (70°C, 20h) at a peeling speed of 30 m/min is 30 times or less than the normal peeling force (PF1). By having this relationship, the high-speed peeling force after heating is low, which is preferable. It is more preferable that the peeling force (PF3) is 25 times or less, and most preferably 20 times or less, the normal peeling force (PF1). It is preferable that the peeling force (PF3) is 30 times or less of the normal peeling force (PF1) because there is a low possibility that the molded release object will be deformed when the molded release object is peeled off at high speed after heating.

In the present invention, a laminated film can be obtained by providing an adhesive layer on at least one side of the release film. The laminated film is obtained, for example, by applying an adhesive composition to the surface of at least one side of the release film of the present invention, drying it as necessary, and forming an adhesive layer on at least one side of the base material. For example, the release layer may have an adhesive layer on the side opposite to the base material.

The present invention is not limited to adhesive sheets, but is used in electronic applications such as structural members for batteries, adhesive layer protection (protection for OCA (Optical Clear Adhesive), protection for adhesive tapes, etc.), separators for transdermal absorbable patches in the medical field, and ceramic condensers. It can also be applied to other uses, such as process paper used in the manufacturing process of parts and protection of image display members. The same effect is expected regarding the effect.

Example

Below, the present invention will be described in more detail using examples, but the present invention is not limited to these examples in any way. The characteristic values used in the present invention were evaluated using the following method.

＜Evaluation＞

(State peel force (PF1))

Attach an adhesive tape (“31B” manufactured by Nitto Denko Co., Ltd.) to the surface of the release film, press it with a pressure roller with a linear pressure of 5 kgf/mm, and leave it for 20 hours under conditions of a temperature of 22°C and a humidity of 60%. did. The release film to which the adhesive tape was attached was cut into strips with a width of 25 mm and a length of 150 mm. One end of the adhesive tape was fixed, one end of the release film was held, and the release film side was pulled at a speed of 300 mm/min. to measure the T-shaped peel strength. For the measurement, a tensile tester (Shimadzu Seisaku Co., Ltd.) was used. “AUTOGRAPHAG-A-1” manufactured by Shaw was used. The results are shown in Table 1.

(Peel force after heating (PF2))

Adhesive tape (manufactured by Nitto Denko Co., Ltd., product name “31B”) is attached to the surface of the release film, and after pressing with a pressure roller with a linear pressure of 5 kgf/mm, the release film with the adhesive tape attached is rolled into a single sheet with a width of 25 mm and a length of 150 mm. It was cut and heated in an oven at a temperature of 70°C for 20 hours. After that, one end of the adhesive tape was fixed, one end of the release film was held, the release film side was pulled and peeled at a speed of 300 mm/min., and the T-shaped peel strength was measured. To measure the T-shaped peel strength, a tensile tester (“AUTOGRAPHAG-A-1” manufactured by Shimadzu Seisakusho Co., Ltd.) was used. The results are shown in Table 1.

(High-speed peel force after heating (PF3))

Adhesive tape (manufactured by Nitto Denko Co., Ltd., product name “31B”) is attached to the surface of the release film, and after pressing with a pressure roller with a linear pressure of 5 kgf/mm, the release film with the adhesive tape attached is rolled into a single sheet with a width of 25 mm and a length of 150 mm. Cut it into pieces and heat it in an oven at 70°C for 20 hours. After that, the release film side is fixed to a metal plate with double-sided tape, one end of the adhesive tape is held, the adhesive tape side is pulled at a speed of 30 m/min to peel, and the 180° peel strength is measured. To measure the 180° peel strength, a tensile tester (“High-Speed Peel Tester TE-701” manufactured by Tester Sangyo Co., Ltd.) was used. The results are shown in Table 1.

(Silicon transferability)

Adhesive tape (manufactured by Nitto Denko Co., Ltd., product name “31B”) is attached to the surface of the release film, and after pressing with a pressure roller with a linear pressure of 5 kgf/mm, the release film with the adhesive tape attached is rolled into a single sheet with a width of 25 mm and a length of 150 mm. It was cut and heated in an oven at a temperature of 70°C for 20 hours. After that, one end of the adhesive tape was fixed, one end of the release film was held, the release film side was pulled and peeled at a speed of 300 mm/min., and the Si strength (Ⅰ ₁ ) of the peeled adhesive tape was measured. Moreover, the Si strength (Ⅰ ₀ ) of the adhesive tape not affixed to the surface of the release film was measured as a blank, and Ⅰ ₁ - Ⅰ ₀ was calculated. In the case of I ₁ - I ₀ > 0, the transition of silicon was observed, _so the transition property _was set as The results are shown in Table 1.

(Example 1)

(Preparation of acrylic resin (A ₁ ) and release layer coating solution)

Stearyl acrylate (CH ₂ = C(H)COOC ₁₅ H ₂₅ ) and hydroxyethyl acrylate (CH ₂ = C(H)COOC ₂ H ₄ OH) were mixed in a ratio of 99:1, and the solid concentration was Toluene was added to 40% by mass, and 0.5 mol% of azobisisobutyronitrile (AIBN) was added and copolymerized under a nitrogen stream to obtain an acrylic resin (A ₁ ).

Acrylic resin (A ₁ ) in the mixing ratio shown in Table 1, melamine resin (Nikalac MW-30, manufactured by Nippon Carbide Co., Ltd.) as the crosslinking agent (B), and higher alcohol (manufactured by Tokyo Kasei Kogyo Co., Ltd.) as the mold release agent (C). , pentadecanol), paratoluenesulfonic acid (Hitachi Kasei Polymer Co., Ltd., dryer #900) was added as a curing catalyst, and a solvent (toluene/MEK = 50/50: mass ratio) was added to adjust the solid content concentration. The release layer coating liquid was obtained at 6.0% by mass.

(Formation of release layer)

The obtained release layer coating solution was coated with a polyethylene terephthalate film (E5100 manufactured by Toyobo Co., Ltd., thickness: 38 μm, surface roughness (Sa): 0.0365 nm (corona-treated surface), surface maximum cross-sectional height (St): 3.72, haze: 3.7. %) was applied to the corona-treated surface using a gravure coater, and then dried at 130°C for 30 seconds to form a release layer with a thickness of 0.2 μm. The obtained release film was evaluated for its normal peeling force, peeling force after heating, and high-speed peeling force after heating. Various composition and evaluation results

(Examples 2 to 5, Comparative Examples 1 to 3)

A release layer was formed in the same manner as in Example 1, except that the composition was changed to that shown in Table 1. The obtained release film was evaluated for its normal peeling force, peeling force after heating, high-speed peeling force after heating, and silicone transferability.

(Comparative Example 4)

(Preparation of acrylic resin (A ₄ ) and release layer coating solution)

Methyl acrylate (CH ₂ = C(H)COOCH ₃ ) was copolymerized by adding toluene so that the solid concentration was 40% by mass, and adding 0.5 mol% of azobisisobutyronitrile (AIBN) under a nitrogen stream. Acrylic resin (A ₄ ) was obtained.

A release layer was formed in the same manner as in Example 1, except that the acrylic resin was changed to _A4 . The obtained release film was evaluated for its normal peeling force, peeling force after heating, high-speed peeling force after heating, and silicone transferability.

(Comparative Example 5)

A release layer was formed in the same manner as in Example 3, except that a thermosetting silicone-based release agent was used together with a platinum catalyst as the release agent. The obtained release film was evaluated for its normal peeling force, peeling force after heating, and high-speed peeling force after heating.

＜Evaluation results＞

According to the present invention, it is possible to provide a release layer film that has light peelability both before and after heating and maintains light release property even when peeled at high speed. On the other hand, in Comparative Example 1, when the total mass of the A-1 component and the A-2 component of the acrylic resin (A) is 100 parts by mass, the mass of A-1 does not exceed 50 parts by mass, so PF1 is large. Because the peeling force increased significantly in PF2, the release layer and the adhesive tape could not be peeled off. In Comparative Example 2, because the amount of the crosslinking agent was too small, sufficient film strength was not obtained, so PF1 and PF2 increased significantly, and PF3 was too large, making it impossible to peel the release layer and the adhesive tape. In Comparative Example 3, since the release agent was not included, PF2 increased significantly, and the release layer and the adhesive tape could not be peeled. In addition, in Comparative Example 4, since the release layer was composed of an acrylic resin not containing components A-1 and A-2, the release layer and the adhesive tape could not be peeled even at room temperature. In Comparative Example 5, since a silicone-based mold release agent was used, it was confirmed that silicone was migrating.

The embodiments and examples disclosed this time should be considered illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the above-described embodiments, and is intended to include all changes within the scope and meaning equivalent to the claims.

The release film of the present invention can be suitably used in applications such as electronic component manufacturing processes where it is difficult to use a silicone release film.

Claims (8)

A release film having a base film and a release layer in this order,
The release layer includes at least an acrylic resin (A), a crosslinking agent (B), and a release agent (C),
The acrylic resin (A) contains at least an A-1 component represented by the following formula (1) and an A-2 component represented by (2),
The release layer does not substantially contain a silicone component,
A release film, characterized in that the ratio a/b of the mass (a) of the acrylic resin (A) contained in the release layer and the mass (b) of the crosslinking agent (B) satisfies the formula (I):
(Ⅰ) 0.1≤a/b≤8.0
[Formula 1]

In formula (1), R ₁ represents (C _n H _2n+1 ) (n = an integer from 8 to 20), R ₄ represents H or CH ₃ ,
[Formula 2]

In formula (2), R ₂ represents (C _m H _2m OH) (m = integer from 1 to 10) or H, and R ₄ represents H or CH ₃ . According to claim 1,
A release film in which the ratio c/b of the mass (b) of the crosslinking agent (B) contained in the release layer and the mass (c) of the release agent satisfies the formula (II):
(Ⅱ) 0.1≤c/b≤12.0. The method of claim 1 or 2,
A release film characterized in that when the total mass of the A-1 component and the A-2 component of the acrylic resin (A) in the release layer is 100 parts by mass, the mass of A-1 exceeds 50 parts by mass. The method according to any one of claims 1 to 3,
A release film in which the release agent (C) does not contain an acrylic group and contains at least a long-chain alkyl group and a reactive functional group that does not contain silicone. The method according to any one of claims 1 to 4,
A release film having a normal peeling force (PF1) of 500mN/50mm or less at a peeling speed of 0.3m/min. The method according to any one of claims 1 to 5,
A release film whose peeling force (PF2) after heating (70°C, 20h) at a peeling speed of 0.3 m/min is twice or less than the above-mentioned normal peeling force (PF1). The method according to any one of claims 1 to 6,
A release film whose peeling force (PF3) after heating (70°C, 20h) at a peeling speed of 30 m/min is 30 times or less than the above-mentioned normal peeling force (PF1). A laminated film in which an adhesive layer is laminated on at least one side of the release film according to any one of claims 1 to 7.