Release film for ceramic green sheet manufacturing process

Abstract

A release film for use in a ceramic green sheet production process, the release film comprising a base material and a release agent layer that is provided on one surface of the base material, wherein the release agent layer is formed from a release agent composition that contains (A) an amino resin, (B) a hydroxyl group-containing acrylic resin, (C) a polyorganosiloxane and (D) an acid catalyst. This release film for use in a ceramic green sheet production process is able to achieve a good balance between easy separability and suppression of migration of a silicone component.

Description

[Technical Field]

[0001] This invention relates to a release film used in the process of manufacturing ceramic green sheets. [Background technology]

[0002] Conventionally, in order to manufacture multilayer ceramic products such as multilayer ceramic capacitors (hereinafter sometimes referred to as "MLCCs") and multilayer ceramic substrates, ceramic green sheets are formed, and multiple of the resulting ceramic green sheets are stacked and fired. Ceramic green sheets are formed by coating a ceramic slurry containing ceramic materials such as barium titanate and titanium oxide onto a release film.

[0003] The above-mentioned release film typically comprises a base material and a release agent layer provided on one side of the base material. Such release films require easy release properties, allowing a thin ceramic green sheet molded on the release film to be peeled off the film without tearing or other damage. For this reason, the release agent layer is widely used and contains polyorganosiloxanes such as polydimethylsiloxane.

[0004] For example, Patent Document 1 proposes a release film comprising a release agent layer made of a thermosetting amino resin and a polyorganosiloxane containing hydroxyl groups. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Patent No. 6395011 [Overview of the project] [Problems that the invention aims to solve]

[0006] Incidentally, the silicone component in the release agent composition can easily migrate to the surface of the ceramic green sheet that comes into contact with the release agent layer. When the silicone component migrates to the surface of the ceramic green sheet, the adhesion and bonding properties on that surface decrease. If a ceramic green sheet is manufactured using a release film that is prone to such silicone component migration, and then a laminated ceramic product is manufactured using that ceramic green sheet, delamination between layers of the laminated ceramic product becomes more likely due to changes over time and environmental conditions. Furthermore, in laminated ceramic products obtained using a ceramic green sheet with reduced adhesion, the positional accuracy of electrodes and other components decreases, and the desired product performance cannot be obtained. For this reason, there is a need for a release film that minimizes the migration of silicone components to the ceramic green sheet.

[0007] Conventional release films, such as those described in Patent Document 1, require further improvement to satisfy both the requirements of easy release and suppression of silicone component migration.

[0008] This invention has been made in view of the above circumstances, and aims to provide a release film for the ceramic green sheet manufacturing process that can achieve both easy release and suppression of silicone component migration. [Means for solving the problem]

[0009] To achieve the above objective, firstly, the present invention provides a release film for a ceramic green sheet manufacturing process, comprising a base material and a release agent layer provided on one side of the base material, wherein the release agent layer is formed from a release agent composition containing an amino resin (A), a hydroxyl group-containing acrylic resin (B), a polyorganosiloxane (C), and an acid catalyst (D) (Invention 1).

[0010] The hydroxyl group-containing acrylic resin (B) has excellent compatibility with the amino resin (A), but poor compatibility with the polyorganosiloxane (C). In the above invention (Invention 1), by using the hydroxyl group-containing acrylic resin (B) in combination with the amino resin (A), the polyorganosiloxane (C) is more likely to segregate on the surface of the release agent layer. Therefore, it becomes possible to achieve mild release properties with a small amount of polyorganosiloxane (C). In this way, the range over which mild release properties are maintained is expanded, and the amount of polyorganosiloxane (C) blended becomes easier to adjust, which reduces the amount of silicone component transferred to the ceramic green sheet and suppresses the transfer of silicone component.

[0011] In the above invention (Invention 1), it is preferable that the content of the hydroxyl group-containing acrylic resin (B) in the release agent composition is 5 parts by mass or more and 200 parts by mass or less per 100 parts by mass of the amino resin (A) (Invention 2).

[0012] In the above inventions (Inventions 1 and 2), it is preferable that the polyorganosiloxane (C) has at least one hydroxyl group in one molecule (Invention 3).

[0013] In the above inventions (Inventions 1 to 3), it is preferable that the polyorganosiloxane (C) has at least one organic group selected from polyester groups, polyether groups, and carbinol groups (Invention 4).

[0014] In the above inventions (Inventions 1 to 4), it is preferable that the weight-average molecular weight of the polyorganosiloxane (C) is 500 or more and 20,000 or less (Invention 5).

[0015] In the above inventions (Inventions 1 to 5), it is preferable that the content of the polyorganosiloxane (C) in the release agent composition is 0.05 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B) (Invention 6).

[0016] In the above inventions (Inventions 1 to 6), it is preferable that the release agent composition contains an alkoxysilane hydrolytic polycondensate (E) having a siloxane bond (Si-O-Si) as a skeleton (Invention 7).

[0017] In the above inventions (Inventions 1 to 7), it is preferable that the acid catalyst (D) contains at least one of a sulfonic acid-based catalyst and a phosphoric acid-based catalyst (Invention 8).

[0018] In the above inventions (Inventions 1 to 8), it is preferable that the release agent composition contains a polyol compound (F) having a molecular weight or a weight average molecular weight of 50 or more and 10,000 or less (Invention 9).

[0019] In the above inventions (Inventions 1 to 9), it is preferable that the thickness of the release agent layer is 0.02 μm or more and 0.5 μm or less (Invention 10).

[0020] In the above inventions (Inventions 1 to 10), it is preferable that the arithmetic mean roughness (Ra) of the surface of the base material on the side of the release agent layer is 1 nm or more and 50 nm or less, and the maximum protrusion height (Rp) of the surface is 10 nm or more and 1000 nm or less (Invention 11).

[0021] In the above inventions (Inventions 1 to 11), it is preferable that the arithmetic mean roughness (Ra) of the surface of the base material on the side opposite to the release agent layer is 10 nm or more and 50 nm or less, and the maximum protrusion height (Rp) of the surface is 100 nm or more and 1000 nm or less (Invention 12).

Advantages of the Invention

[0022] According to the release film for the ceramic green sheet manufacturing process according to the present invention, it is possible to achieve both easy peelability and suppression of the migration of the silicone component.

Embodiments for Carrying Out the Invention

[0023] Hereinafter, embodiments of the present invention will be described. The release film for the ceramic green sheet manufacturing process according to this embodiment (hereinafter sometimes simply referred to as "release film") comprises a base material and a release agent layer provided on one side of the base material. The side of the release agent layer opposite to the base material may hereinafter be referred to as the "release surface".

[0024] 1. Base material The substrate in this embodiment is not particularly limited as long as it can laminate a release agent layer. Examples of such substrates include films made of polyester such as polyethylene terephthalate or polyethylene naphthalate, polyolefins such as polypropylene or polymethylpentene, polycarbonate, and polyvinyl acetate, and may be a single layer or a multilayer of two or more layers of the same or different materials. Among these, polyester films are preferred, polyethylene terephthalate films are particularly preferred, and biaxially oriented polyethylene terephthalate films are even more preferred. Polyethylene terephthalate films are less likely to generate dust during processing and use, and therefore can effectively prevent defects in ceramic slurry coating caused by dust, for example.

[0025] Furthermore, to improve adhesion with the release agent layer provided on its surface, the substrate may be subjected to surface treatment, such as oxidation or embossing, or primer treatment, on one or both sides as desired. Examples of oxidation methods include corona discharge treatment, plasma discharge treatment, chromium oxidation (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. Examples of embossing methods include sandblasting and thermal spraying. These surface treatment methods are appropriately selected depending on the type of substrate film, but corona discharge treatment is generally preferred in terms of effectiveness and ease of operation.

[0026] The arithmetic mean roughness (Ra) of the surface of the substrate facing the release agent layer is preferably 50 nm or less, particularly preferably 40 nm or less, and even more preferably 30 nm or less. By having an arithmetic mean roughness (Ra) of 50 nm or less, it becomes easier to keep the arithmetic mean roughness (Ra) and maximum protrusion height (Rp) on the release surface within the range described later, thereby effectively suppressing the occurrence of defects in the molded ceramic green sheet. The lower limit of the arithmetic mean roughness (Ra) of the surface of the substrate facing the release agent layer is not particularly limited, and may be, for example, 1 nm or more, particularly 3 nm or more, and even 5 nm or more.

[0027] The maximum protrusion height (Rp) on the release agent layer side of the substrate is preferably 1000 nm or less, particularly preferably 700 nm or less, and even more preferably 500 nm or less. By keeping the maximum protrusion height (Rp) at 1000 nm or less, it becomes easier to keep the arithmetic mean roughness (Ra) and maximum protrusion height (Rp) on the release surface within the range described later, thereby effectively suppressing the occurrence of defects in the molded ceramic green sheet. The lower limit of the maximum protrusion height (Rp) on the release agent layer side of the substrate is not particularly limited; for example, it may be 10 nm or more, particularly 30 nm or more, and even 50 nm or more.

[0028] Furthermore, the arithmetic mean roughness (Ra) of the surface of the substrate opposite to the release agent layer is preferably 10 nm or more, particularly preferably 15 nm or more, and even more preferably 18 nm or more. Having an arithmetic mean roughness (Ra) of 10 nm or more makes it easier to suppress winding misalignment when winding the release film into a roll. Also, when forming the roll, it suppresses an excessive increase in the effective contact area between the surface of the substrate opposite to the release agent layer and the release surface in contact with it, thereby effectively suppressing blocking and reducing the amount of charge on the release film unwound from the roll. On the other hand, the arithmetic mean roughness (Ra) of the surface of the substrate opposite to the release agent layer is preferably 50 nm or less, particularly preferably 40 nm or less, and even more preferably 30 nm or less. The arithmetic mean roughness (Ra) of 50 nm or less effectively suppresses the transfer of the surface shape (especially the uneven shape) of the substrate on the side opposite the release agent layer to the surface of the ceramic green sheet that comes into contact with it, when the release film and the ceramic green sheet formed on the release film are wound into a roll for transport and storage. As a result, it becomes easier to maintain the smoothness of the ceramic green sheet.

[0029] The maximum protrusion height (Rp) on the side of the substrate opposite to the release agent layer is preferably 100 nm or more, particularly preferably 200 nm or more, and even more preferably 300 nm or more. Having a maximum protrusion height (Rp) of 100 nm or more makes it easier to suppress roll misalignment and blocking, similar to the case where the arithmetic mean roughness (Ra) is 10 nm or more, and also reduces the amount of charge on the release film. Furthermore, the maximum protrusion height (Rp) on the side of the substrate opposite to the release agent layer is preferably 1000 nm or less, particularly preferably 700 nm or less, and even more preferably 500 nm or less. Having a maximum protrusion height (Rp) of 1000 nm or less makes it easier to maintain good smoothness of the ceramic green sheet, similar to the case where the arithmetic mean roughness (Ra) is 50 nm or less.

[0030] The surface roughness of the substrate described above can be measured using a surface roughness measuring instrument in a known manner, for example, in the same way as the method for measuring the surface roughness of the peeled surface in the test example described later.

[0031] The thickness of the substrate is not particularly limited, but is preferably 10 μm or more, more preferably 15 μm or more, and even more preferably 20 μm or more. Furthermore, the thickness of the substrate is preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 125 μm or less.

[0032] 2. Release agent layer The release agent layer in this embodiment is formed from a release agent composition containing an amino resin (A), a hydroxyl group-containing acrylic resin (B), a polyorganosiloxane (C), and an acid catalyst (D).

[0033] In the release agent layer of this embodiment, by using an amino resin (A) and a hydroxyl group-containing acrylic resin (B) in combination, the polyorganosiloxane (C) is more likely to segregate on the surface of the release agent layer. This is because the hydroxyl group-containing acrylic resin (B) has excellent compatibility with the amino resin (A), but poor compatibility with the polyorganosiloxane (C). When the polyorganosiloxane (C) is more likely to segregate on the surface of the release agent layer in this way, it becomes possible to achieve light release properties with a small amount of polyorganosiloxane (C). If a large amount of polyorganosiloxane is used to achieve light release properties, problems such as an increase in the amount of silicone migration tend to occur due to poor reactivity. In this embodiment, since the range in which light release properties are maintained is widened and the amount of polyorganosiloxane (C) blended is easily adjusted, the amount of silicone component migration to the ceramic green sheet can be reduced, and the migration of silicone component can be suppressed. As a result, it is possible to increase the correlation adhesion between the resulting ceramic green sheets.

[0034] (1) Amino resin (A) In the release film according to this embodiment, the release agent composition contains an amino resin (A). When forming a release agent layer from the release agent composition, the amino resin (A) undergoes a condensation reaction in the presence of an acid catalyst (D), so that a three-dimensional structure of amino resin (A) is formed in the resulting release agent layer. Furthermore, since amino resin (A) also reacts with hydroxyl groups, it also reacts with a hydroxyl group-containing acrylic resin (B), and the acrylic resin (B) is also incorporated into the three-dimensional structure. The above reaction can be induced, for example, by heating. Because the release agent layer contains the above-described three-dimensional structure, it exhibits sufficient elasticity, and as a result, the release film according to this embodiment can exhibit excellent release properties. In this specification, the term "amino resin" refers to a component that can undergo a condensation reaction and does not necessarily have to be a polymer compound. Here, the component may not undergo any condensation reaction at all, or it may undergo a partial condensation reaction.

[0035] As the above amino resin (A), known resins can be used, for example, melamine resin, urea resin, guanamine resin, or aniline resin. Among these, it is preferable to use melamine resin, which has a very fast condensation reaction rate. In this specification, the term "melamine resin" means an aggregate of one type of melamine compound, or a mixture containing multiple types of melamine compounds and / or a polynuclear body formed by the condensation of said melamine compounds.

[0036] The melamine resin described above preferably contains a melamine compound represented by the following general formula (a), or a polynuclear body formed by the condensation of two or more such melamine compounds. [ka]

[0037] In formula (a), X is preferably -H, -CH2-OH, or -CH2-OR. These groups constitute the reactants in the condensation reaction between the melamine compounds. Specifically, the -NH group formed when X becomes H can undergo condensation reactions with the -N-CH2-OH group and the -N-CH2-OR group. Furthermore, the -N-CH2-OH group formed when X becomes -CH2-OH and the -N-CH2-OR group formed when X becomes -CH2-OR can both undergo condensation reactions with the -NH group, the -N-CH2-OH group, and the -N-CH2-OR group.

[0038] In the above -CH2-OR group, R preferably represents an alkyl group having 1 to 8 carbon atoms. The number of carbon atoms is preferably 1 to 6, and particularly preferably 1 to 3. Examples of alkyl groups having 1 to 8 carbon atoms include methyl, ethyl, propyl, butyl, pentyl, hexyl, and octyl groups, with methyl being particularly preferred.

[0039] The above X values ​​may be the same or different. Similarly, the above R values ​​may be the same or different.

[0040] Melamine compounds generally include types such as the full ether type where all X are -CH2-OR, the imino-methylol type where at least one X is -CH2-OH and at least one X is H, the methylol type where at least one X is -CH2-OH and no H X is present, and the imino type where at least one X is H and no -CH2-OH X is present. Any of these types of melamine compounds may be used in the release film according to this embodiment.

[0041] In a release agent composition for forming a release agent layer, the weight-average molecular weight of the amino resin (A) is preferably 150 or more, particularly preferably 300 or more, and even more preferably 500 or more. This stabilizes the crosslinking rate and allows for the formation of a smoother release surface. Furthermore, the weight-average molecular weight is preferably 10,000 or less, particularly preferably 5,000 or less, and even more preferably 4,000 or less. This results in a moderately low viscosity of the release agent composition, making it easier to apply the release agent composition coating solution to the substrate. Note that the weight-average molecular weight in this specification is a value on a standard polystyrene basis measured by gel permeation chromatography (GPC).

[0042] (2) Hydroxyl group-containing acrylic resin (B) In the release film according to this embodiment, the release agent composition contains a hydroxyl group-containing acrylic resin (B).

[0043] The hydroxyl group-containing acrylic resin (B) can preferably be produced by consisting only of acrylic monomers containing hydroxyl groups (hereinafter sometimes referred to as "hydroxyl group-containing monomers"), or by copolymerizing hydroxyl group-containing monomers with other copolymerizable monomers. Known methods for production include bulk polymerization, solution polymerization in organic solvents, and emulsion polymerization in water.

[0044] Examples of hydroxyl group-containing monomers include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, neopentyl glycol mono(meth)acrylate, glycerin mono(meth)acrylate, polycaprolactone-modified hydroxylalkyl (meth)acrylate, and polycaprolactone-modified poly(oxyalkylene)(meth)acrylate. Hydroxyl group-containing monomers may be used individually or in combination of two or more. In this specification, (meth)acrylate means both acrylate and methacrylate. The same applies to other similar terms.

[0045] Other copolymerizable acrylic monomers include, for example, alkyl esters of (meth)acrylic acid such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl acrylate, cyclohexyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, isobornyl (meth)acrylate, and stearyl (meth)acrylate; carboxyl group-containing monomers such as (meth)acrylic acid, maleic acid, and maleic anhydride; and N,N-dimethylammonium Examples include aminoalkyl (meth)acrylates such as noethyl (meth)acrylate, N,N-diethylaminoethyl (meth)acrylate, and N,N-dimethylaminopropyl (meth)acrylate; acrylamide, methacrylamide, or their derivatives; quaternary ammonium base-containing monomers such as 2-(methacryloyloxy)ethyltrimethylammonium chloride and 2-(methacryloyloxy)ethyltrimethylammonium bromide; sulfoalkyl (meth)acrylates such as (meth)acrylamide-alkanesulfonic acids such as 2-acrylamido-2-methylpropanesulfonic acid and 2-sulfoethyl (meth)acrylate; and acrylonitrile and methacrylonitrile. Other copolymerizable monomers other than acrylic monomers include vinyl acetate, styrene, vinyltoluene, and α-methylstyrene. These may be used individually or in combination of two or more.

[0046] The hydroxyl value of the hydroxyl group-containing acrylic resin (B) is preferably 10 mg KOH / g or more, particularly preferably 15 mg KOH / g or more, and even more preferably 20 mg KOH / g or more. This allows the amino resin (A) and the hydroxyl group-containing acrylic resin (B) to react well and cure. Furthermore, the above hydroxyl value is preferably 200 mg KOH / g or less, particularly preferably 150 mg KOH / g or less, and even more preferably 100 mg KOH / g or less. This allows the amino resin (A) and the hydroxyl group-containing acrylic resin (B) to react well and cure, while also maintaining sufficient stability of the blended coating solution. In this specification, the hydroxyl value of the acrylic resin shall be the value measured in accordance with the neutralization titration method (JIS K0070).

[0047] The glass transition temperature Tg of the hydroxyl group-containing acrylic resin (B) is preferably -20°C or higher, particularly preferably 30°C or higher, and even more preferably 50°C or higher. This results in a highly elastic coating formed by reaction with the amino resin (A), making it easier to achieve easy peelability from the ceramic green sheet. Furthermore, the glass transition temperature Tg is preferably 150°C or lower, particularly preferably 120°C or lower, and even more preferably 100°C or lower. This allows the amino resin (A) and the hydroxyl group-containing acrylic resin (B) to be appropriately compatible, ensuring sufficient reactivity. The glass transition temperature shall be the value measured using a differential scanning calorimetry (DSC).

[0048] The weight-average molecular weight of the hydroxyl group-containing acrylic resin (B) is preferably 500 or more, particularly preferably 3000 or more, and even more preferably 5000 or more. This results in a highly elastic coating formed by reaction with the amino resin (A) and curing, and its poor compatibility with polyorganosiloxane (C) makes it easier for polyorganosiloxane (C) to segregate on the surface of the release agent layer, thus making it easier to achieve light peelability from the ceramic green sheet. Furthermore, the weight-average molecular weight is preferably 200,000 or less, particularly preferably 150,000 or less, and even more preferably 100,000 or less. This makes it more difficult for polyorganosiloxane (C) and hydroxyl group-containing acrylic resin (B) to be compatible, making it easier for polyorganosiloxane (C) to segregate on the side opposite to the substrate, thus making it easier to achieve light peelability from the ceramic green sheet.

[0049] In this embodiment, the hydroxyl group-containing acrylic resin (B) is preferably substantially unmodified with silicone. This makes it easier to segregate the polyorganosiloxane (C) on the surface of the release agent layer. Specifically, the amount of silicone modification is preferably 0.50 mmol / g or less, particularly preferably 0.20 mmol / g or less, even more preferably 0.10 mmol / g or less, and most preferably 0 mmol / g.

[0050] The content of hydroxyl group-containing acrylic resin (B) in the release agent composition is preferably 5 parts by mass or more, particularly preferably 15 parts by mass or more, and more preferably 25 parts by mass or more, per 100 parts by mass of amino resin (A). Furthermore, the above content is preferably 200 parts by mass or less, particularly preferably 150 parts by mass or less, and more preferably 120 parts by mass or less, per 100 parts by mass of amino resin (A). By having the content of hydroxyl group-containing acrylic resin (B) within the above range, polyorganosiloxane (C), which has poor compatibility with hydroxyl group-containing acrylic resin (B), is more likely to segregate on the surface of the release agent layer, making it possible to more effectively exhibit light release properties with a small amount of polyorganosiloxane (C).

[0051] (3) Polyorganosiloxane (C) In the release film according to this embodiment, the release agent composition contains polyorganosiloxane (C). The inclusion of polyorganosiloxane (C) in the release agent composition moderately reduces the surface free energy of the formed release agent layer. This moderately reduces the peeling force required to peel the release film from the ceramic green sheet formed on the release surface of the release film, resulting in good release properties. As described above, in this embodiment, good release properties can be achieved even with a small amount of polyorganosiloxane (C), thus suppressing the migration of silicone components to the ceramic green sheet.

[0052] The polyorganosiloxane (C) described above is not particularly limited, as long as it can impart the desired release properties to the release agent layer. In the release film according to this embodiment, it is preferable that the polyorganosiloxane (C) has at least one hydroxyl group in one molecule. The presence of a hydroxyl group in the polyorganosiloxane (C) enables a condensation reaction with the amino resin (A) or the hydroxyl group-containing acrylic resin (B), and as a result, the migration of the polyorganosiloxane (C) from the release agent layer to the ceramic green sheet is easily suppressed.

[0053] The structure of polyorganosiloxane (C), other than the hydroxyl group, is not particularly limited as long as it does not inhibit the aforementioned peelability or the reactions between amino resins (A) themselves, between amino resins (A) and hydroxyl-containing acrylic resins (B), and between hydroxyl-containing acrylic resins (B) themselves. As polyorganosiloxane (C), a polymer of a silicon-containing compound represented by the following general formula (b) can be used. [ka]

[0054] In equation (b), m is an integer greater than or equal to 1. Also, R 1 ~R 8 Each of these independently represents a hydroxyl group, an organic group (including organic groups containing a hydroxyl group), or a group other than these. Here, R 1 ~R 8 If at least one of them is a hydroxyl group or an organic group having a hydroxyl group, then R 3 ~R 8 Preferably, at least one of these groups is one of these groups. That is, if the polyorganosiloxane (C) has a hydroxyl group or an organic group having a hydroxyl group, it is preferable that the group is located at the end of the polyorganosiloxane (C). The presence of a hydroxyl group at the end makes it easier for the polyorganosiloxane (C) to undergo a condensation reaction with the amino resin (A) or the hydroxyl group-containing acrylic resin (B) to be fixed into a three-dimensional structure, thereby effectively suppressing the migration of the polyorganosiloxane (C).

[0055] Examples of the organic group include a polyester group, a polyether group, and a carbinol group. In particular, the polyorganosiloxane (C) in the present embodiment preferably has at least one of a polyester group, a polyether group, and a carbinol group. When the polyorganosiloxane (C) has at least one of a polyester group, a polyether group, and a carbinol group, the polyorganosiloxane (C), the amino resin (A), and the hydroxyl group-containing acrylic resin (B) are easily mixed well in the release agent composition.

[0056] Here, the polyorganosiloxane (C) is more easily compatible with the amino resin (A) than with the hydroxyl group-containing acrylic resin (B). By mixing both the amino resin (A) and the hydroxyl group-containing acrylic resin (B), it becomes possible to create a state in which the polyorganosiloxane (C) is likely to segregate while suppressing extreme phase separation during the curing of the coating film. As a result, the condensation reaction between the polyorganosiloxane (C) and the amino resin (A) or the hydroxyl group-containing acrylic resin (B) as described above proceeds well, and the migration of the polyorganosiloxane (C) is effectively suppressed. In the present specification, the "organic group" does not include an alkyl group described later.

[0057] Examples of groups other than the hydroxy group and the organic group (including the organic group having a hydroxy group) include alkyl groups having 1 to 12 carbon atoms. Examples of the alkyl group having 1 to 12 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group, etc., and a methyl group is particularly preferable.

[0058] R 1 ~R 8 may be the same or different. Also, R 1 and R 2 When there are a plurality of them, R 1 and R 2 may be the same or different from each other.

[0059] The weight-average molecular weight of polyorganosiloxane (C) is preferably 20,000 or less, particularly preferably 10,000 or less, and even more preferably 5,000 or less. This results in excellent compatibility between polyorganosiloxane (C) and amino resin (A), making it easier to form a release agent layer with a good surface condition. Furthermore, it makes it easier to suppress the migration of polyorganosiloxane (C) from the release agent layer to the ceramic green sheet. On the other hand, the weight-average molecular weight of polyorganosiloxane (C) is preferably 500 or more, particularly preferably 1,000 or more, and even more preferably 2,000 or more. This makes it easier for polyorganosiloxane (C) to lower the surface free energy at the release surface of the release agent layer, making it easier to achieve the desired release properties.

[0060] The content of polyorganosiloxane (C) in the release agent composition is preferably 0.05 parts by mass or more, more preferably 0.10 parts by mass or more, particularly preferably 0.30 parts by mass or more, and even more preferably 0.50 parts by mass or more, based on 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B). This makes it easier for the release film according to this embodiment to achieve the desired release properties from the ceramic green sheet. Furthermore, the content of polyorganosiloxane (C) is preferably 10 parts by mass or less, more preferably 7 parts by mass or less, particularly preferably 5 parts by mass or less, and even more preferably 4 parts by mass or less, based on 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B). This makes it possible to effectively suppress the migration of polyorganosiloxane (C) from the release agent layer to the ceramic green sheet. In the release film according to this embodiment, even with a small amount of polyorganosiloxane (C), sufficient easy-release properties are achieved for the reasons described above.

[0061] (4) Acid catalyst (D) In the release film according to this embodiment, the release agent composition contains an acid catalyst (D). The inclusion of the acid catalyst (D) in the release agent composition allows for efficient reactions between amino resins (A), between hydroxyl group-containing acrylic resins (B), between amino resins (A) and hydroxyl group-containing acrylic resins (B), and between polyorganosiloxane (C) and the alkoxysilane hydrolysis polycondensate (E) described later, resulting in the formation of a release agent layer exhibiting sufficient elasticity.

[0062] The acid catalyst (D) described above is not particularly limited as long as it has catalytic activity for the reaction described above, but it is especially preferable to use at least one of a sulfonic acid-based catalyst and a phosphoric acid-based catalyst. These catalysts have relatively high catalytic activity, which makes it easier to promote the hardening of the release agent layer at lower temperatures. Examples of sulfonic acid-based catalysts include p-toluenesulfonic acid, methanesulfonic acid, and dodecylbenzenesulfonic acid, and among these, p-toluenesulfonic acid is preferred. When a full-ether type melamine resin is mainly used as the amino resin (A), it is preferable to use a sulfonic acid-based catalyst from the viewpoint of efficiently promoting the condensation reaction of the melamine resin. Examples of phosphoric acid-based catalysts include phosphoric acid and phosphorous acid. When an iminomethylol-type melamine resin is mainly used as the amino resin (A), it is preferable to use a phosphoric acid-based catalyst from the viewpoint of efficiently promoting the condensation reaction of the melamine resin. Examples of acid catalysts (D) other than those described above include hydrochloric acid, sulfuric acid, nitric acid, etc.

[0063] The content of the acid catalyst (D) in the release agent composition is preferably 0.5 parts by mass or more, more preferably 0.7 parts by mass or more, and more preferably 1.0 part by mass or more, based on 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B). This allows for efficient condensation reactions between amino resins (A), condensation reactions between hydroxyl group-containing acrylic resins (B), and reactions between the amino resin (A), the hydroxyl group-containing acrylic resin (B), the polyorganosiloxane (C), and the alkoxysilane hydrolysis polycondensate (E) described later. Furthermore, the above content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and more preferably 10 parts by mass or less, based on 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B). This makes it easier to retain low molecular weight components in the three-dimensional structure formed in the release agent layer, and effectively suppresses the precipitation of such components from the release agent layer.

[0064] (3) Hydrolyzed polycondensate of alkoxysilane (E) In the release film according to this embodiment, it is also preferable that the release agent composition contains an alkoxysilane hydrolyzed polycondensate (E) having a siloxane bond (Si-O-Si) as its backbone. When the release agent composition contains the alkoxysilane hydrolyzed polycondensate (E), the alkoxysilane hydrolyzed polycondensate (E) reacts with the hydroxyl group-containing acrylic resin (B) and the hydroxyl group-containing polyorganosiloxane (C), forming an even harder film, which makes it easier to exhibit light release properties on the ceramic green sheet. In addition, the effect of suppressing the migration of silicone components is further improved.

[0065] The above-mentioned alkoxysilane hydrolysis polycondensate (E) is not particularly limited as long as it does not significantly impair the release properties of the release film. Preferably, the alkoxysilane hydrolysis polycondensate (E) is obtained by hydrolyzing a mixture of tetraalkoxysilane and / or its oligomer and phenylalkoxysilane and / or its oligomer, and then by a polycondensation reaction.

[0066] The above tetraalkoxysilane is preferably represented by the formula Si(OR)4, and the oligomer of the tetraalkoxysilane is Si n O n-1 (OR) 2n+2 It is preferable that the formulas be expressed as follows. In these formulas, R is preferably an alkyl group having 1 to 6 carbon atoms, and n is preferably an integer from 2 to 10.

[0067] Preferred specific examples of the above-mentioned tetraalkoxysilane include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, and tetrabutoxysilane. Among these, at least one of tetramethoxysilane and tetraethoxysilane is preferred from the viewpoint of ease of availability and reactivity in hydrolysis reactions.

[0068] Tetraalkoxysilane oligomers are preferably obtained by hydrolysis and condensation reactions of alkoxysilane monomers as described above. Commercially available products such as methyl silicate 51, an average tetramer oligomer of tetramethoxysilane, and ethyl silicate 40, an average pentamer oligomer of tetraethoxysilane, are preferably used.

[0069] The above phenylalkoxysilane is Ph n Si(OR) 4-n It is preferable that the product be represented by the following formula. In this formula, Ph represents a phenyl group, R independently represents an alkyl group having 1 to 6 carbon atoms, and n represents an integer from 1 to 2. Furthermore, the oligomer of the phenylalkoxysilane is preferably a 2 to 10-mer of the phenylalkoxysilane represented by the above formula, and is particularly preferably a 2 to 3-mer.

[0070] Preferred specific examples of phenylalkoxysilanes include phenyltrimethoxysilane, phenyltriethoxysilane, phenyltripropoxysilane, and phenyltri-n-butoxysilane. Among these, it is preferable to use at least one of phenyltrimethoxysilane and phenyltriethoxysilane from the viewpoint of excellent reactivity.

[0071] Alternatively, a diphenyldialkoxysilane, in which two phenyl groups are bonded to a silicon atom, may be used as the phenylalkoxysilane. In this case, the alkoxy groups are preferably methoxy or ethoxy groups.

[0072] The hydrolysis and polycondensation reactions of a mixture of tetraalkoxysilane and / or its oligomer and phenylalkoxysilane and / or its oligomer can be carried out by known methods. Furthermore, the ratio of tetraalkoxysilane and / or its oligomer to phenylalkoxysilane and / or its oligomer in the above mixture is preferably 1:1 to 1:0.1 by mass ratio.

[0073] The content of alkoxysilane hydrolyzed polycondensate (E) in the release agent composition is preferably 2 parts by mass or more, more preferably 5 parts by mass or more, and more preferably 10 parts by mass or more, based on 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B). This results in a better effect in suppressing the migration of silicone components. Furthermore, the content of alkoxysilane hydrolyzed polycondensate (E) is preferably 50 parts by mass or less, more preferably 40 parts by mass or less, and more preferably 30 parts by mass or less, based on 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B). This makes it easier to cure the release agent layer well, and makes it easier to achieve good release properties and suppression of silicone component migration.

[0074] Furthermore, in the release film according to this embodiment, the antistatic properties are also improved by using an alkoxysilane hydrolyzed polycondensate (E). Conventionally, it was predicted that the alkoxysilane hydrolyzed polycondensate (E) described above would not provide antistatic properties when used as a material for the release agent layer. However, contrary to this prediction, the inventors have discovered that by using an alkoxysilane hydrolyzed polycondensate (E), it is possible to achieve the level of antistatic properties required for a release film used in the ceramic green sheet manufacturing process. For example, the surface resistivity of the release film according to this embodiment can be equivalent to that of a polyethylene terephthalate film, which is an insulator.

[0075] One possible reason for achieving this antistatic property, though not the only one, is that the alkoxysilane hydrolysis polycondensate (E) alters the triboelectric series of the components contained in the release agent layer. Generally, the triboelectric series refers to the order in which two substances are arranged, with those that are more likely to become positively charged being higher up and those that are more likely to become negatively charged being lower down, when rubbed together. The further apart the substances are in this triboelectric series, the more likely they are to become charged when rubbed together.

[0076] Typically, the positions of amino resin (A) and hydroxyl group-containing acrylic resin (B) in the triboelectric series are relatively far from the substrate material (e.g., polyethylene terephthalate film). Therefore, in a release agent layer containing amino resin (A), release charging of the release film is very likely to occur when the release film is unwound from a roll.

[0077] On the other hand, the position of the alkoxysilane hydrolyzed polycondensate (E) in the triboelectric series is closer to polyethylene terephthalate, which is commonly used as a base material for release films used in the manufacture of ceramic green sheets, compared to the amino resin (A) and the hydroxyl group-containing acrylic resin (B). In this embodiment, the release agent composition contains such alkoxysilane hydrolyzed polycondensate (E), so that when the release agent layer is formed, the alkoxysilane hydrolyzed polycondensate (E) binds to the amino resin (A) or the hydroxyl group-containing acrylic resin (B). The resulting bond has a position in the triboelectric series that is very close to that of polyethylene terephthalate compared to the amino resin (A) and the hydroxyl group-containing acrylic resin (B) before binding.

[0078] Furthermore, the release agent composition in this embodiment contains polyorganosiloxane (C), and the position of this polyorganosiloxane (C) in the triboelectric series is relatively close to that of polyethylene terephthalate. Depending on the functional groups it possesses, polyorganosiloxane (C) can react and bond with amino resin (A), hydroxyl group-containing acrylic resin (B), or alkoxysilane hydrolyzed polycondensate (E). As a result, the position in the triboelectric series of the crosslinked structure formed by these bondings is very close to that of polyethylene terephthalate.

[0079] As described above, in a release agent layer using alkoxysilane hydrolysis polycondensate (E), the triboelectric series difference between the components contained in the release agent layer and the substrate (polyethylene terephthalate) is greatly reduced compared to conventional release agent layers, and as a result, it becomes less prone to release charge.

[0080] It should be noted that the above explanation is not the sole reason why release films using alkoxysilane hydrolyzed polycondensates (E) are less prone to static charge, and other additional reasons may exist. However, such additional reasons would rule out the possibility that alkoxysilane hydrolyzed polycondensates (E) act as a general antistatic agent. Some compounds corresponding to alkoxysilane hydrolyzed polycondensates (E) are commonly used as antistatic agents. When alkoxysilane hydrolyzed polycondensates (E) are used as antistatic agents, the surface of the component on which they are used will have a large number of hydroxyl groups present, thereby lowering the surface resistance and exhibiting an antistatic effect. However, in release agent layers using alkoxysilane hydrolyzed polycondensates (E), most of the hydroxyl groups present in the alkoxysilane hydrolyzed polycondensates (E) are used in reactions with amino resins (A), hydroxyl-containing acrylic resins (B), or polyorganosiloxanes (C), and have disappeared. Therefore, it is presumed that in the release agent layer using alkoxysilane hydrolyzed polycondensate (E), alkoxysilane hydrolyzed polycondensate (E) does not function as a general antistatic agent. This is also suggested by the fact that the surface resistance value of the release agent layer using alkoxysilane hydrolyzed polycondensate (E) is almost the same as when alkoxysilane hydrolyzed polycondensate (E) is not used.

[0081] (6) Other ingredients In addition to the above components, the release agent composition may also contain other components such as polyol compounds (F), dispersants, crosslinking agents, reaction inhibitors, adhesion enhancers, and lubricants.

[0082] The polyol compound (F) is not particularly limited, and various known compounds can be used. The inclusion of the polyol compound (F) in the release agent composition makes it easier to adjust the elastic modulus of the release agent layer to a desired range, and also improves the curability when curing the release agent composition to form the release agent layer. From this viewpoint, it is preferable to use a polyol compound (F) with a molecular weight or weight-average molecular weight of 50 or more. Furthermore, it is preferable to use one with a weight-average molecular weight of 10,000 or less, particularly 5,000 or less, and even more preferably 3,000 or less.

[0083] Specific examples of polyol compounds (F) include aliphatic diols such as 1,6-hexanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, 2-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 1,9-nonanediol, 1,10-decanediol, butylethylpropanediol, and butylethylpentanediol; alicyclic diols such as 1,4-cyclohexanedimethanol; trimethylolpropane, pentaerythritol, ditrimethylolpropane, dipentaerythritol, dimer diol, hydrogenated dimer diol, trimertriol, hydrogenated trimertriol, castor oil, castor oil-based modified polyols, alkylene oxide adducts of bisphenol compounds or their derivatives, etc. Polymer polyols such as polyether polyols, polyester polyols, polycarbonate polyols, acrylic polyols, and polyolefin polyols are also included. Examples of the above-mentioned polyether polyols include polyalkylene glycols such as polyethylene glycol (containing ethylene glycol), polypropylene glycol (containing propylene glycol), and polytetramethylene glycol, as well as copolymers containing multiple alkylene oxides as monomer components, such as ethylene oxide-propylene oxide copolymers (alkylene oxide-other alkylene oxides). These may be used individually or in combination of two or more types.

[0084] When the release agent composition contains a polyol compound (F), the content of the polyol compound (F) in the release agent composition is preferably 0.1 parts by mass or more, particularly preferably 0.5 parts by mass or more, and more preferably 1 part by mass or more, based on 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B). Furthermore, the content is preferably 100 parts by mass or less, particularly preferably 70 parts by mass or less, and more preferably 40 parts by mass or less, based on 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B). By having the polyol compound (F) content within the above range, the release force can be easily adjusted to the desired range.

[0085] (7) Physical properties of the release agent layer, etc. In the release film according to this embodiment, the surface free energy of the release surface of the release agent layer is 17 mJ / m 2 It is preferable that the concentration be greater than or equal to 19 mJ / m³, and particularly 19 mJ / m³. 2 Preferably, it should be 21 mJ / m³ or more, and even more preferably 21 mJ / m³ 2 It is preferable that the surface free energy is 40 mJ / m 2 The following is preferable, and in particular 35 mJ / m³ 2 Preferably, it is less than 30 mJ / m³. 2 The following is preferable. In the release film according to this embodiment, the release agent layer is formed from a release agent composition containing the aforementioned components, making it easier to adjust the surface free energy at the release surface to the range described above. And, with the surface free energy within the above range, the release film according to this embodiment is more likely to exhibit better release properties to the molded ceramic green sheet. The method for measuring the surface free energy is as shown in the test examples described later.

[0086] In the release film according to this embodiment, the thickness of the release agent layer is preferably 0.02 μm or more, particularly preferably 0.03 μm or more, and even more preferably 0.04 μm or more. This makes it easier to cure the release agent layer well, and consequently, easier to achieve the desired release properties. Furthermore, the thickness is preferably 0.5 μm or less, particularly preferably 0.4 μm or less, and even more preferably 0.3 μm or less. This makes it less likely for the release agent composition to be affected by curing shrinkage, makes it easier to suppress the occurrence of curl in the release film, and makes it easier to maintain high accuracy in the thickness of the molded ceramic green sheet (especially accuracy in the width direction).

[0087] 3. Physical properties of release film for ceramic green sheet manufacturing process In the release film according to this embodiment, the arithmetic mean roughness (Ra) of the release surface is preferably 50 nm or less, particularly preferably 40 nm or less, and even more preferably 30 nm or less. This results in a release surface with excellent smoothness, effectively suppressing the occurrence of defects such as pinholes and thickness variations in the molded ceramic green sheet. The lower limit of the arithmetic mean roughness (Ra) is not particularly limited; for example, it may be 1 nm or more, particularly 3 nm or more, and even more preferably 5 nm or more.

[0088] Furthermore, in the release film according to this embodiment, the maximum protrusion height (Rp) of the release surface is preferably 1000 nm or less, particularly preferably 700 nm or less, and even more preferably 500 nm or less. This results in a release surface with excellent smoothness, effectively suppressing the occurrence of defects such as pinholes and thickness variations in the molded ceramic green sheet. The lower limit of the maximum protrusion height (Rp) is not particularly limited; for example, it may be 10 nm or more, particularly 30 nm or more, and even 50 nm or more.

[0089] The details of the measurement methods for the arithmetic mean roughness (Ra) and maximum protrusion height (Rp) of the delamination surface are as described in the test examples below.

[0090] In the release film according to this embodiment, the peeling force required to peel the release film from the ceramic green sheet molded on the release surface is preferably 20 mN / 50 mm or less, particularly preferably 18 mN / 50 mm or less, and even more preferably 15 mN / 50 mm or less. In the release film according to this embodiment, by including an amino resin (A) and a hydroxyl group-containing acrylic resin (B) as the main components in the release agent layer, the polyorganosiloxane (C) is more likely to segregate on the surface compared to the case where only the amino resin (A) is the main component. As a result, it is possible to achieve light peelability with a small amount of polyorganosiloxane (C), and the peeling force can be easily set to the low value described above. The lower limit of the peeling force is not particularly limited, but in order to prevent unintended peeling of the ceramic green sheet, it is preferably 5 mN / 50 mm or more, particularly preferably 8 mN / 50 mm or more, and even more preferably 10 mN / 50 mm or more. Details of the method for measuring the peeling force described above are as described in the test examples below.

[0091] 4. Method for manufacturing release film for ceramic green sheet manufacturing process The method for manufacturing the release film in this embodiment is not particularly limited, as long as it includes forming a release layer from the release agent composition described above. For example, it is preferable to apply a coating solution containing the release agent composition described above and optionally an organic solvent to one side of a substrate, and then dry and heat the resulting coating to cure the release agent composition and form a release layer, thereby obtaining a release film.

[0092] Specific coating methods mentioned above include, for example, gravure coating, bar coating, spray coating, spin coating, knife coating, roll coating, and die coating.

[0093] There are no particular restrictions on the organic solvents used, and a variety of them can be used. For example, hydrocarbon compounds such as toluene, hexane, and heptane, as well as isopropyl alcohol, isobutyl alcohol, acetone, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and mixtures thereof can be used. In particular, it is preferable to use a mixture of methyl ethyl ketone and isopropyl alcohol.

[0094] The release agent composition coated as described above is preferably heat-cured. In this case, the heating temperature is preferably 100°C or higher, and particularly preferably 110°C or higher. Furthermore, the heating temperature is preferably 150°C or lower, and particularly preferably 140°C or lower. The heating time for heat curing is preferably 10 seconds or more, and particularly preferably 15 seconds or more. Furthermore, the heating time is preferably 120 seconds or less, and particularly preferably 90 seconds or less.

[0095] 5. Method of using release film in the ceramic green sheet manufacturing process In this embodiment, the release film is preferably used to manufacture a ceramic green sheet. In this case, first, a ceramic slurry containing a ceramic material such as barium titanate or titanium oxide is applied to the release surface of the release agent layer.

[0096] The above coating can be carried out using, for example, a slot die coating method or a doctor blade method. Examples of binder components contained in the ceramic slurry include butyral resins and acrylic resins. Examples of solvents contained in the ceramic slurry include organic solvents and aqueous solvents.

[0097] Following the coating of the slurry onto the release surface, the coated ceramic slurry is dried to form a ceramic green sheet. After forming the ceramic green sheet, it is separated from the release film. In this embodiment, the release film has excellent release properties from the ceramic green sheet because the release agent layer is formed from a release agent composition optionally containing an amino resin (A), a hydroxyl group-containing acrylic resin (B), a polyorganosiloxane (C), and other materials. Therefore, the ceramic green sheet can be peeled off with appropriate peeling force without cracking or breaking. Furthermore, in this embodiment, the amount of polyorganosiloxane (C) used in the release film can be reduced, thus reducing the amount of silicone component transferred to the ceramic green sheet.

[0098] The embodiments described above are provided to facilitate understanding of the present invention and are not intended to limit it. Accordingly, each element disclosed in the above embodiments is intended to include all design modifications and equivalents that fall within the technical scope of the present invention.

[0099] For example, other layers may be provided on the surface of the substrate opposite to the release agent layer, or between the substrate and the release agent layer. [Examples]

[0100] The present invention will be described in more detail below with reference to examples, but the scope of the present invention is not limited to these examples.

[0101] [Example 1] 75 parts by mass (based on solid content, same applies hereafter) of methylated melamine resin (manufactured by Nippon Carbide Co., Ltd., product name "MW-30", weight-average molecular weight: 508) as amino resin (A), 25 parts by mass of hydroxyl group-containing acrylic resin (B1) (manufactured by DIC Corporation, product name "Acrydic A-807-BA") as hydroxyl group-containing acrylic resin (B), and 2 parts by mass of carbinol-modified polydimethylsiloxane (C1; manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6001", weight-average molecular weight: 2400) as polyorganosiloxane (C) were diluted with a mixed solvent of isopropyl alcohol, methyl ethyl ketone, and cyclohexanone (mixing ratio: isopropyl alcohol:methyl ethyl ketone:cyclohexanone = 40:40:20). To this diluted solution, 4 parts by mass of p-toluenesulfonic acid (manufactured by Shin-Etsu Chemical Co., Ltd., product name "PS-80") as an acid catalyst (D) was added in a diluted state, and the mixture was uniformly stirred to obtain a coating solution of a stripping agent composition with a solid content concentration of 1.8% by mass.

[0102] On the other hand, a biaxially oriented polyethylene terephthalate film (thickness: 31 μm) was prepared as a substrate. One side of this substrate (hereinafter sometimes referred to as the "first side") had an arithmetic mean roughness (Ra) of 24 nm and a maximum protrusion height (Rp) of 451 nm. The other side of this substrate (hereinafter sometimes referred to as the "second side") had an arithmetic mean roughness (Ra) of 25 nm and a maximum protrusion height (Rp) of 465 nm.

[0103] As described above, the coating solution of the release agent composition was applied to the first surface of the substrate using a bar coater, and the resulting coating film was heated at 125°C for 30 seconds to dry and cure, forming a release agent layer. This resulted in a release film having a release agent layer laminated on one side of the substrate.

[0104] Furthermore, the thickness of the release agent layer of the release film was measured as described in Test Example 2 below, and was found to be 0.07 μm.

[0105] [Example 2] A release film was obtained in the same manner as in Example 1, except that the amount of amino resin (A) was changed to 50 parts by mass and the amount of hydroxyl group-containing acrylic resin (B) was changed to 50 parts by mass.

[0106] [Example 3] A release film was obtained in the same manner as in Example 1, except that hydroxyl group-containing acrylic resin (B) was replaced with hydroxyl group-containing acrylic resin (B2) (manufactured by DIC Corporation, product name "Acrydic WMU-504").

[0107] [Example 4] A release film was obtained in the same manner as in Example 1, except that hydroxyl group-containing acrylic resin (B) was replaced with hydroxyl group-containing acrylic resin (B3) (manufactured by DIC Corporation, product name "Acrydic WAU-139").

[0108] [Example 5] A release film was obtained in the same manner as in Example 1, except that polyorganosiloxane (C) was replaced with carbinol-modified polydimethylsiloxane (C2; manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6002", weight-average molecular weight: 4600).

[0109] [Example 6] A release film was obtained in the same manner as in Example 1, except that polyorganosiloxane (C) was replaced with carbinol-modified polydimethylsiloxane (C3; manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6003", weight-average molecular weight: 8000).

[0110] [Example 7] A release film was obtained in the same manner as in Example 1, except that polyorganosiloxane (C) was replaced with side-chain carbinol-modified polydimethylsiloxane (C4; manufactured by Shin-Etsu Chemical Co., Ltd., product name "X-22-4039", weight-average molecular weight: 5300).

[0111] [Example 8] A release film was obtained in the same manner as in Example 1, except that the amount of polyorganosiloxane (C) was changed to 4 parts by mass.

[0112] [Example 9] 75 parts by mass of methylated melamine resin (manufactured by Nippon Carbide Co., Ltd., product name "MW-30", weight-average molecular weight: 508) as amino resin (A), 25 parts by mass of hydroxyl group-containing acrylic resin (B1) (manufactured by DIC Corporation, product name "Acrydic A-807-BA") as hydroxyl group-containing acrylic resin (B), 2.2 parts by mass of carbinol-modified polydimethylsiloxane (C1; manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6001", weight-average molecular weight: 2400) as polyorganosiloxane (C), and 10 parts by mass of alkoxysilane hydrolyzed polycondensate (E) (E1; manufactured by Colcoat, product name "N-103X") were diluted with a mixed solvent of isopropyl alcohol, methyl ethyl ketone, and cyclohexanone (mixing ratio: isopropyl alcohol:methyl ethyl ketone:cyclohexanone = 40:40:20). To this diluted solution, 4.4 parts by mass of p-toluenesulfonic acid (manufactured by Shin-Etsu Chemical Co., Ltd., product name "PS-80") as an acid catalyst (D) was added in a diluted manner, and the mixture was uniformly stirred to obtain a coating solution of a release agent composition with a solid content concentration of 1.8% by mass. A release film was obtained in the same manner as in Example 1, except that this coating solution was used.

[0113] [Example 10] A release film was obtained in the same manner as in Example 9, except that the alkoxysilane hydrolyzed polycondensate (E) was replaced with "PS-903" (E2) manufactured by Colcoat.

[0114] [Example 11] 75 parts by mass of methylated melamine resin (manufactured by Nippon Carbide Co., Ltd., product name "MW-30", weight-average molecular weight: 508) as amino resin (A), 25 parts by mass of hydroxyl group-containing acrylic resin (B1) (manufactured by DIC Corporation, product name "Acrydic A-807-BA") as hydroxyl group-containing acrylic resin (B), 2.2 parts by mass of carbinol-modified polydimethylsiloxane (C1; manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6001", weight-average molecular weight: 2400) as polyorganosiloxane (C), and 10 parts by mass of ethylene glycol (F1; manufactured by Nippon Shokubai Co., Ltd., product name "(mono)ethylene glycol", molecular weight: 62) as polyol compound (F) were diluted with a mixed solvent of isopropyl alcohol, methyl ethyl ketone, and cyclohexanone (mixing ratio: isopropyl alcohol:methyl ethyl ketone:cyclohexanone = 40:40:20). To this diluted solution, 4.4 parts by mass of p-toluenesulfonic acid (manufactured by Shin-Etsu Chemical Co., Ltd., product name "PS-80") as an acid catalyst (D) was added in a diluted manner, and the mixture was uniformly stirred to obtain a coating solution of a release agent composition with a solid content concentration of 1.8% by mass. A release film was obtained in the same manner as in Example 1, except that this coating solution was used.

[0115] [Example 12] A release film was obtained in the same manner as in Example 11, except that the polyol compound (F) was replaced with propylene glycol (F2; manufactured by Sankyo Chemical Co., Ltd., product name "Propylene Glycol", molecular weight: 76).

[0116] [Example 13] A release film was obtained in the same manner as in Example 11, except that the amount of polyorganosiloxane (C) was changed to 4.4 parts by mass.

[0117] [Example 14] The amino resin (A) consists of 75 parts by mass of methylated melamine resin (manufactured by Nippon Carbide Co., Ltd., product name "MW-30", weight-average molecular weight: 508), 25 parts by mass of hydroxyl group-containing acrylic resin (B) consisting of hydroxyl group-containing acrylic resin (B1) (manufactured by DIC Corporation, product name "Acrydic A-807-BA"), and polyorganosiloxane (C) consisting of 2.4 parts by mass of carbinol-modified polydimethylsiloxane (C1; manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6001", weight-average molecular weight: 2400). Parts by mass of a polyol compound (F1) (manufactured by Nippon Shokubai Co., Ltd., product name "N-103X"), 10 parts by mass of an alkoxysilane hydrolyzed polycondensate (E) (E1; manufactured by Colcoat, product name "N-103X"), and 10 parts by mass of ethylene glycol (F1; manufactured by Nippon Shokubai Co., Ltd., product name "(mono)ethylene glycol", molecular weight: 62) were diluted with a mixed solvent of isopropyl alcohol, methyl ethyl ketone, and cyclohexanone (mixing ratio: isopropyl alcohol:methyl ethyl ketone:cyclohexanone = 40:40:20). To this diluted solution, 4.8 parts by mass of p-toluenesulfonic acid (manufactured by Shin-Etsu Chemical Co., Ltd., product name "PS-80") as an acid catalyst (D) were added in a diluted state, and the mixture was uniformly stirred to obtain a coating solution of a release agent composition with a solid content of 1.8% by mass. A release film was obtained in the same manner as in Example 1, except that this coating solution was used.

[0118] [Example 15] A release film was obtained in the same manner as in Example 1, except that the thickness of the release agent layer was changed to 0.04 μm.

[0119] [Example 16] A release film was obtained in the same manner as in Example 1, except that the substrate was changed to a biaxially oriented polyethylene terephthalate film (thickness: 31 μm) having an arithmetic mean roughness (Ra) of 13 nm and a maximum protrusion height (Rp) of 210 nm on the first surface, and an arithmetic mean roughness (Ra) of 13 nm and a maximum protrusion height (Rp) of 224 nm on the second surface.

[0120] [Example 17] A release film was obtained in the same manner as in Example 1, except that the substrate was changed to a biaxially oriented polyethylene terephthalate film (thickness: 31 μm) having an arithmetic mean roughness (Ra) of 7 nm and a maximum protrusion height (Rp) of 70 nm on the first surface, and an arithmetic mean roughness (Ra) of 28 nm and a maximum protrusion height (Rp) of 498 nm on the second surface.

[0121] [Comparative Example 1] A release film was obtained in the same manner as in Example 1, except that the hydroxyl group-containing acrylic resin (B) was not included.

[0122] [Comparative Example 2] A release film was obtained in the same manner as in Comparative Example 1, except that the amount of polyorganosiloxane (C) was changed to 4 parts by mass.

[0123] [Comparative Example 3] A release film was obtained in the same manner as in Comparative Example 2, except that polyorganosiloxane (C) was replaced with carbinol-modified polydimethylsiloxane (C3; manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6003", weight-average molecular weight: 8000).

[0124] [Comparative Example 4] A release film was obtained in the same manner as in Comparative Example 2, except that polyorganosiloxane (C) was replaced with side-chain carbinol-modified polydimethylsiloxane (C4; manufactured by Shin-Etsu Chemical Co., Ltd., product name "X-22-4039", weight-average molecular weight: 5300).

[0125] [Comparative Example 5] A release film was obtained in the same manner as in Comparative Example 3, except that the amount of polyorganosiloxane (C) was changed to 15 parts by mass.

[0126] [Comparative Example 6] 100 parts by mass of thermosetting addition-reaction type silicone resin (manufactured by Shin-Etsu Chemical Co., Ltd., product name "KS-847H") was diluted with toluene, and then 2 parts by mass of platinum catalyst (manufactured by Shin-Etsu Chemical Co., Ltd., product name "CAT-PL-50T") was added and mixed to obtain a coating solution of a release agent composition with a solid content concentration of 1.5% by mass.

[0127] The obtained coating solution was applied to the first surface of the same substrate as in Example 1 using a bar coater, and the resulting coating film was heated at 125°C for 30 seconds to dry and cure, forming a release agent layer. This resulted in a release film in which a release agent layer was laminated on one side of the substrate.

[0128] Furthermore, the thickness of the release agent layer of the release film was measured as described in Test Example 2 below, and was found to be 0.09 μm.

[0129] [Test Example 1] (Evaluation of compatibility of release agent compositions) 2 g each of the amino resin (A) and hydroxyl group-containing acrylic resin (B) used in the examples were diluted with ethyl acetate to a solid content of 60% by mass, and 0.02 g of undiluted polyorganosiloxane (C) was mixed with each of these solutions. The appearance of the mixtures was visually observed, and the compatibility of the release agent compositions was evaluated according to the following criteria. The results are shown in Table 2. A…The mixture of amino resin (A) and polyorganosiloxane (C) was transparent, while the mixture of hydroxyl group-containing acrylic resin (B) and polyorganosiloxane (C) was cloudy. B... The mixture of amino resin (A) and polyorganosiloxane (C) became cloudy, and the mixture of hydroxyl group-containing acrylic resin (B) and polyorganosiloxane (C) also became cloudy. C...Other than A and B above

[0130] [Test Example 2] (Measurement of the thickness of the release agent layer) The thickness (μm) of the release agent layer of the release films obtained in the examples and comparative examples was measured using a spectroscopic ellipsometer (JAWoollam, product name "M-2000"). The results are shown in Table 2.

[0131] [Test Example 3] (Evaluation of the hardening properties of the release agent layer) The release films obtained in the examples and comparative examples were subjected to a load of 200 g / cm² on the surface of the release agent layer using a cloth containing methyl ethyl ketone (manufactured by Ozu Sangyo Co., Ltd., product name "BEMCOT AP-2").2 The surface was polished 10 times back and forth. Afterwards, the peeled surface was visually inspected, and the hardening properties of the release agent layer were evaluated according to the following criteria. The results are shown in Table 2. A... The release agent layer did not dissolve or detach. B...Partial dissolution of the release agent layer was observed. C... The release agent layer completely dissolved and detached from the substrate.

[0132] [Test Example 4] (Measurement of surface free energy on the delamination surface) For the release films obtained in the examples and comparative examples, the contact angles of various droplets with respect to the release surface of the release agent layer were measured, and based on these values, the surface free energy (mJ / m) was calculated using the Kitazaki-Hata theory. 2 The contact angle was determined using a contact angle meter (Kyowa Interface Science Co., Ltd., product name "DM-701") and measured by the static droplet method in accordance with JIS R3257:1999. For the droplets, diiodomethane was used as the "dispersion component," 1-bromonaphthalene as the "dipole component," and distilled water as the "hydrogen bonding component." The results are shown in Table 2.

[0133] [Test Example 5] (Measurement of surface roughness of the peeled surface) The substrate-side surface of the release films obtained in the examples and comparative examples was fixed to a glass plate with double-sided adhesive tape. The arithmetic mean roughness (Ra; nm) and maximum protrusion height (Rp; nm) on the release surface were measured using an optical interference surface shape observation device (Vecco, product name "WYKO-1100") in PSI mode at 50x magnification. Measurements for Ra and Rp were performed 10 times each, and the average values ​​were taken as the Ra and Rp of the release surface. The results are shown in Table 2.

[0134] [Test Example 6] (Evaluation of electrostatic charge during unwinding) We prepared the release films obtained in the examples and comparative examples, as well as the same films used in the examples and comparative examples (hereinafter sometimes referred to as "substrate films").

[0135] Furthermore, a device equipped with a metal guide roll was prepared. The guide roll of this device was positioned with a space of 500 mm (length of the test piece) or more between it and the floor, and its roll axis was parallel to the floor and locked in place so as not to rotate relative to the device. The side of the prepared base film to be coated with the release agent was attached to the guide roll with adhesive, and the side opposite to the coating side facing outwards.

[0136] On the other hand, the release films obtained in the examples and comparative examples were cut to a size of 100 mm in width and 500 mm in length, cardboard was attached to one end in the long direction, and a 300 g weight was attached to the cardboard portion to obtain a test piece for measuring electrostatic charge. After the test piece was discharged using an electrostatic brush, it was confirmed that the test piece was not charged (in the range of -2 kV to +2 kV) using an electrostatic measuring instrument (manufactured by Kasuga Electric Co., Ltd., product name "KSD-1000", measurement mode: High).

[0137] Next, the test specimen, which had been confirmed to be free of static charge, was placed on a guide roll covered with a base film, with the end without the weight attached being held by hand. The specimen was then balanced with the hand holding the end of the specimen to prevent it from rotating relative to the guide roll.

[0138] Then, by manually pulling the end without the weight towards the floor, the specimen was lowered by 300 mm, and the end with the weight was raised by 300 mm. Subsequently, the pulling force was released, causing the end with the weight to lower by 300 mm and the end without the weight to rise by 300 mm. By performing this raising and lowering motion once back and forth against the guide roll, friction was created between the test specimen and the film, simulating the conditions in which electrostatic discharge occurs during the peeling process when the release film is unwound from the winding to the unwinding of the release film.

[0139] Subsequently, the electrostatic charge (kV) of the test specimen removed from the guide roll was measured using the electrostatic measuring instrument described above. Based on this charge value, the electrostatic charge during unwinding was evaluated according to the following criteria. The results are shown in Table 2. A... The absolute value of the electric charge was 20kV or less. B... The absolute value of the electric charge was greater than 20kV and less than or equal to 25kV. C... The absolute value of the charge was over 25kV.

[0140] [Test Example 7] (Evaluation of slurry coating properties) A ceramic slurry was prepared by adding 100 parts by mass of barium titanate powder (BaTiO3; manufactured by Sakai Chemical Industry Co., Ltd., product name "BT-03", average particle size: 300 nm), 8 parts by mass of polyvinyl butyral resin as a binder (manufactured by Sekisui Chemical Co., Ltd., product name "Eslec B·K BM-2"), and 4 parts by mass of dioctyl phthalate as a plasticizer (manufactured by Kanto Chemical Co., Ltd., product name "Dioctyl Phthalate Grade 1") to 135 parts by mass of a mixture of toluene and ethanol (mass ratio 6:4), mixing and dispersing the mixture in the presence of zirconia beads using a ball mill, and then removing the beads.

[0141] The ceramic slurry was applied to the release surface of the release films obtained in the examples and comparative examples using a die coater, covering an area 250 mm wide and 10 m long, and then dried in a dryer at 80°C for 1 minute. This formed a 3 μm thick ceramic green sheet on the release film.

[0142] Next, the laminate of the ceramic green sheet and release film obtained as described above was illuminated with a fluorescent lamp from the release film side, and the degree of repulsion at both ends of the ceramic green sheet was visually confirmed. The slurry coating properties were then evaluated according to the following criteria. The results are shown in Table 2 as the slurry coating properties during the manufacturing of the "thin film (3 μm)" ceramic green sheet. A... No gunshots were detected. B...A slight (less than 0.5mm) defect was observed. C...Rejections of 0.5 mm or larger were observed.

[0143] Furthermore, the slurry coating properties were evaluated in the same manner as above, except that the barium titanate powder used as the material for the ceramic slurry was changed to "BT-02" (average particle size: 200 nm) manufactured by Sakai Chemical Industry Co., Ltd., and the thickness of the molded ceramic green sheet was changed to 1 μm. The results are also shown in Table 2 as slurry coating properties during the manufacture of "ultra-thin (1 μm)" ceramic green sheets.

[0144] [Test Example 8] (Measurement of peeling force of acrylic adhesive tape) Acrylic adhesive tape (manufactured by Nitto Denko Corporation, product name "31B Tape") was applied to the release surface of the release films obtained in the examples and comparative examples by using a 2 kg roller and making one pass back and forth motion. In this state, the samples were left to stand for 24 hours in an atmosphere of 23 degrees Celsius and 50% humidity. Next, the release film side of the prepared samples was fixed to a rigid plate with double-sided adhesive tape. Then, using a tensile testing machine, the acrylic adhesive tape was peeled off the release film at a peeling angle of 180° and a peeling speed of 300 mm / min, and the force required to peel (peeling force; mN / 20 mm) was measured. The results are shown in Table 2.

[0145] [Test Example 9] (Measurement of peeling force on ceramic green sheet) A ceramic green sheet "ultra-thin (1 μm)" was formed on the release surface of the release film using the same procedure as in Test Example 7. The resulting laminate of the ceramic green sheet and release film was left to stand for 24 hours in an atmosphere of 23°C and 50% RH, and then cut into 20 mm wide strips, which were used as the measurement samples.

[0146] The ceramic green sheet side of the measurement sample was attached and fixed to a flat plate. Using a tensile testing machine (Shimadzu Corporation, product name "AG-IS500N"), the release film was peeled from the ceramic green sheet at a peel angle of 90° and a peel speed of 300 mm / min, and the force required for peeling (peel force; mN / 50 mm) was measured. The results are shown in Table 2.

[0147] [Test Example 10] (Evaluation of adhesion between ceramic green sheets) A thin ceramic green sheet (3 μm) was formed on the release surface of the release film using the same procedure as in Test Example 7. The two resulting ceramic green sheets were stacked so that the green sheet surface that was in contact with the release agent layer and the green sheet surface that was not in contact with the release agent layer were facing each other, and a load of 50 kg / cm² was applied. 2 Pressurized at 50°C (pressure area: 25 cm²) 2 After that, the interface between the two ceramic green sheets was visually observed through the release film. Then, the adhesion between the ceramic green sheets was evaluated based on the following criteria. A... The ceramic sheets were in close contact with each other over a pressure surface area of ​​more than 50%. B... The ceramic sheets were in close contact with each other, covering between 30% and 50% of the pressure area. C... The ceramic sheets were in close contact with each other over a pressure area of ​​less than 30%.

[0148] [Test Example 11] (Evaluation of Handling) The handling characteristics of the release films obtained in the examples and comparative examples when rolled were evaluated. Specifically, 400 mm wide, 2000 m long release films were wound onto a 3-inch outer diameter ABS resin core at a winding tension of 15 kg / m and a winding speed of 150 m / min. During the winding process, the slipperiness of the contacting release films, the ease of air release when rolled, and the resistance to winding misalignment of the release films were evaluated according to the following criteria. The results are shown in Table 2. A... The release films had good sliding properties when in contact with each other, and air escaped well when the release film was rolled into a roll, preventing the release film from shifting during winding. B... The slipperiness between the contacting release films was slightly poor, and the air escaped slightly poorly when the release film was rolled up, resulting in some slight misalignment, but this did not cause any problems. C...The slipperiness between the contacting release films was poor, and air did not escape well when the release films were rolled up, resulting in significant winding misalignment.

[0149] [Test Example 12] (Evaluation of Blocking Resistance) The release films obtained in the examples and comparative examples were wound into rolls 400 mm wide and 5000 m long. These release film rolls were stored for 30 days in an environment of 23 ± 5°C and 50 ± 10% humidity. Subsequently, the resistance to blocking was evaluated when attempting to unwind the release film from the roll, according to the following criteria. The results are shown in Table 2. A... No blocking occurred at all, and the release film could be dispensed smoothly. B... Although there was a tendency for blocking to occur, the release film could be dispensed. C... Blocking occurred, preventing the release film from being dispensed.

[0150] [Test Example 13] (Evaluation of silicone migration) A polyvinyl butyral (PVB) binder resin (manufactured by Sekisui Chemical Co., Ltd., product name: "BL-S") was diluted with a mixed solvent of toluene and ethanol (mixing ratio 50:50) to obtain a PVB resin solution with a solid content of 20% by mass. This PVB resin solution was uniformly applied to the release surface of the release films obtained in the examples and comparative examples using a 35 μm applicator, and then dried in a dryer at 60°C for 1 minute. This resulted in a release film with a 4 μm thick PVB resin sheet laminated on it.

[0151] The release film was peeled off the PVB resin sheet, and the silicon atom ratio (atomic %) was calculated using the following formula based on the amount of silicon atoms (Si), carbon atoms (C), and oxygen atoms (O) measured by X-ray photoelectron spectroscopy (XPS) on the surface of the PVB resin sheet that was in contact with the peeled surface of the release film. The results are shown in Table 2. Silicon atom ratio (atomic %) = [(amount of Si) / {(amount of C) + (amount of O) + (amount of Si)}] × 100

[0152] Furthermore, based on the obtained silicon atom ratio, the silicone migration properties were evaluated according to the following criteria. The results are shown in Table 2. A...Silicon atom ratio is less than 0.5 atomic percent B...Silicon atom ratio of 0.5 atomic% or more, and less than 1.0 atomic% C...Silicon atom ratio of 1.0 atom or more Furthermore, if the silicon atom ratio is 0.5 atomic percent or higher, pinholes may occur during slurry coating, or misalignment may occur during the process of laminating the ceramic green sheets, potentially resulting in defective multilayer ceramic products.

[0153] Details of the abbreviations and other terms listed in the table are as follows: [Hydroxygroup-containing acrylic resin (B)] B1: Hydroxyl group-containing acrylic resin (manufactured by DIC Corporation, product name "Acrydic A-807-BA", hydroxyl value: 22.0-27.0 mg KOH / g, Tg: 65℃, weight-average molecular weight: 65000) B2: Hydroxyl group-containing acrylic resin (manufactured by DIC Corporation, product name "Acrydic WMU-504", hydroxyl value: 53.0-61.0 mg KOH / g, Tg: 60℃, weight-average molecular weight: 9000) B3: Hydroxyl group-containing acrylic resin (manufactured by DIC Corporation, product name "Acrydic WAU-139", hydroxyl value: 47.0-53.0 mg KOH / g, Tg: 50℃, weight-average molecular weight: 8000) [Polyorganosiloxane (C)] C1: Carbinol-modified polydimethylsiloxane (both terminals) (Manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6001", weight-average molecular weight: 2400) C2: Carbinol-modified polydimethylsiloxane (both terminals) (Manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6002", weight-average molecular weight: 4600) C3: Carbinol-modified polydimethylsiloxane (both terminals) (Manufactured by Shin-Etsu Chemical Co., Ltd., product name "KF-6003", weight-average molecular weight: 8000) C4: Side-chain carbinol-modified polydimethylsiloxane (Manufactured by Shin-Etsu Chemical Co., Ltd., product name "X-22-4039", weight-average molecular weight: 5300) [Alkoxysilane hydrolyzed polycondensate (E)] E1: Manufactured by Colcoat, product name "N-103X" E2: Manufactured by Colcoat, product name "PS-903" [Polyol compound (F)] F1: Ethylene glycol (manufactured by Nippon Shokubai Co., Ltd., product name "(mono)ethylene glycol", molecular weight: 62) F2: Propylene glycol (manufactured by Sankyo Chemical Co., Ltd., product name "Propylene Glycol", molecular weight: 76)

[0154] [Table 1]

[0155] [Table 2]

[0156] As can be seen from Table 2, the release films obtained in the examples exhibited low peeling force on the ceramic green sheet and low migration of silicone components. Furthermore, the release films obtained in the examples were found to have good performance in terms of slurry coating properties, curability of the release agent layer, smoothness (surface roughness) of the release surface, handling properties, and blocking resistance. [Industrial applicability]

[0157] The release film for the ceramic green sheet manufacturing process of the present invention is suitable for forming ceramic green sheets.

Claims

1. A release film for the ceramic green sheet manufacturing process, comprising a base material and a release agent layer provided on one side of the base material, The aforementioned release agent layer is formed from a release agent composition containing an amino resin (A), a hydroxyl group-containing acrylic resin (B), a polyorganosiloxane (C), and an acid catalyst (D). The amount of the hydroxyl group-containing acrylic resin (B) in the release agent composition is 15 parts by mass or more and 200 parts by mass or less, based on 100 parts by mass of the amino resin (A). The content of the polyorganosiloxane (C) in the release agent composition is 0.05 parts by mass or more and 10 parts by mass or less, based on 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B). The content of the acid catalyst (D) in the release agent composition is 0.5 parts by mass or more and 30 parts by mass or less, based on 100 parts by mass of the total of the amino resin (A) and the hydroxyl group-containing acrylic resin (B). The weight-average molecular weight of the hydroxyl group-containing acrylic resin (B) is 500 or more and 200,000 or less. The weight-average molecular weight of the polyorganosiloxane (C) is 500 or more and 20,000 or less. The polyorganosiloxane (C) has an organic group having a hydroxyl group at either the terminal or side chain, The hydroxyl value of the hydroxyl group-containing acrylic resin (B) is 10 mg KOH / g or more and 100 mg KOH / g or less. A release film for the ceramic green sheet manufacturing process, characterized by the following features.

2. The release film for the ceramic green sheet manufacturing process according to claim 1, characterized in that the polyorganosiloxane (C) has at least one organic group selected from polyester groups, polyether groups, and carbinol groups.

3. The release agent composition is characterized by containing an alkoxysilane hydrolysis polycondensate (E) having a siloxane bond (Si-O-Si) as its backbone, as described in claim 1 or 2, for use in the ceramic green sheet manufacturing process.

4. The release film for the ceramic green sheet manufacturing process according to any one of claims 1 to 3, characterized in that the acid catalyst (D) comprises at least one of a sulfonic acid-based catalyst and a phosphoric acid-based catalyst.

5. The release agent composition is characterized by containing a polyol compound (F) having a molecular weight or weight-average molecular weight of 50 or more and 10,000 or less, as described in any one of claims 1 to 4, for use in the manufacturing process of ceramic green sheets.

6. The release film for the ceramic green sheet manufacturing process according to any one of claims 1 to 5, characterized in that the thickness of the release agent layer is 0.02 μm or more and 0.5 μm or less.

7. The release film for the ceramic green sheet manufacturing process according to any one of claims 1 to 6, characterized in that the arithmetic mean roughness (Ra) of the surface on the release agent layer side of the substrate is 1 nm or more and 50 nm or less, and the maximum protrusion height (Rp) of the surface is 10 nm or more and 1000 nm or less.

8. The release film for the ceramic green sheet manufacturing process according to any one of claims 1 to 7, characterized in that the arithmetic mean roughness (Ra) of the surface of the substrate opposite to the release agent layer is 10 nm or more and 50 nm or less, and the maximum protrusion height (Rp) of the surface is 100 nm or more and 1000 nm or less.

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