WO2015141551A1

WO2015141551A1 - Release agent composition, release film, release film roll, and process for producing said roll

Info

Publication number: WO2015141551A1
Application number: PCT/JP2015/057271
Authority: WO
Inventors: 矢野　宏和
Original assignee: リンテック株式会社
Priority date: 2014-03-19
Filing date: 2015-03-12
Publication date: 2015-09-24
Also published as: JPWO2015141551A1; CN106103635A; KR20160135256A

Abstract

A release agent composition which comprises a linear polyorganosiloxane (A) having, in the molecule, at least two reactive functional groups each comprising an alkenyl group, a branched organosiloxane oligomer (B) having at least two alkenyl groups in the molecule, a crosslinking agent (C), and a solvent (D) and which has a surface tension, as measured in a 23°C environment having a relative humidity of 50%, of less than 23.0 mN/m. The release agent composition has a viscosity at 23°C of 0.48 mPa·s or higher and has a peel force measured by the following test of 65 mN/40 mm or less: a release film comprising a base constituted of a polyester film having a thickness of 31 µm and a release agent layer formed from the release agent composition on one surface of the base is prepared; a 3 µm-thick resin film constituted of a polyvinyl butyral is laminated to the release surface of the release film to obtain a layered structure; and the resin film is fixed and the release film is peeled therefrom at a peel angle of 180°.

Description

Release agent composition, release film, release film winding body and method

The present invention relates to a release agent composition and a release film. In this specification, the concept of the term “film” includes the concept of the term “tape” and the concept of the term “sheet”.

In recent years, there has been a demand for a release film having a light release property that can be applied to a thin green sheet having a thickness of 1 μm or less. As disclosed in Patent Document 1 and the like, a release agent containing a crosslinked product containing a branched organosiloxane oligomer by adding a branched organosiloxane oligomer and a crosslinking agent to a release agent composition for forming a release agent layer It is known to improve the peeling performance by forming a layer.

JP 2008-150515 A

However, by improving the release performance of the release agent layer, the coating properties of the release agent composition and the film forming property of the release agent layer are reduced, and as a result, the surface properties of the obtained release agent layer may be reduced. is there. For example, when a release agent composition is applied on a base film to form a release film composed of a base film and a release layer, the thickness of the release layer of the obtained release film is uniform. In some cases, the pinhole or the like may be reduced.

An object of the present invention is to provide a release agent composition capable of forming a release agent layer excellent in release performance and surface properties. Moreover, this invention also makes it a subject to provide a peeling film provided with the peeling agent layer which is excellent in peeling performance and surface property.

In order to solve the above-mentioned problems, the present inventors have examined that a release agent measured using an environment of 23 ° C. and 50% relative humidity while using a plurality of types of siloxane polymers containing a branched organosiloxane oligomer. A new release agent layer having excellent release performance and surface properties can be formed by setting the surface tension of the composition to less than 23.0 mN / m and the viscosity at 23 ° C. to 0.48 mPa · s or more. I got a good knowledge.

Furthermore, by making the mass ratio of the multiple types of siloxane polymers contained in the release agent composition within an appropriate range, it is possible to more stably form a release agent layer with excellent release performance and surface properties. I also got new knowledge.

The present invention provided on the basis of this finding is as follows.
(1) A linear polyorganosiloxane (A) having at least two reactive functional groups composed of alkenyl groups in one molecule and a branched organosiloxane oligomer (B) having at least two alkenyl groups in one molecule ), A crosslinking agent (C), and a solvent (D), and the surface tension measured in an environment of 23 ° C. and 50% relative humidity is less than 23.0 mN / m. The release agent composition has a viscosity at 23 ° C. of 0.48 mPa · s or more, a base material made of a polyester film having a thickness of 31 μm, and the release layer laminated on one surface of the base material. A release film provided with a release agent layer formed from an agent composition, and a laminate structure obtained by laminating a 3 μm thick resin film made of polyvinyl butyral on the release surface of the release film A release agent composition characterized by having a peel force measured by performing a test of fixing the resin film and peeling the release film at a peel angle of 180 ° with respect to the body, of 65 mN / 40 mm or less.

(2) The release agent composition according to (1), wherein the mass ratio of the linear polyorganosiloxane (A) to the branched organosiloxane oligomer (B) is 1/9 or more and 9 or less.

(3) The release agent composition according to (1) or (2), wherein the solvent (D) contains an aprotic polar organic compound.

(4) The release agent composition according to (3), wherein the solvent (D) is a mixed solvent of an aprotic polar organic compound and a nonpolar organic compound.

(5) A release film comprising a base film and a release agent layer laminated on one main surface of the base film, wherein the release agent layer is any of (1) to (4) above A release film formed from the release agent composition described above.

(6) The release film according to (5), wherein an arithmetic average roughness Ra of the release surface of the release agent layer is less than 15.5 nm.

The release agent composition according to the present invention can form a release agent layer excellent in release performance and surface properties. Moreover, according to this invention, a peeling film provided with the peeling agent layer excellent in peeling performance and surface property is provided.

Hereinafter, embodiments of the present invention will be described.
1. Release Agent Composition The release agent composition according to one embodiment of the present invention contains the components listed below as essential components:
Linear polyorganosiloxane (A);
Branched organosiloxane oligomer (B);
A cross-linking agent (C); and a solvent (D).
Hereinafter, each component will be described, followed by optional components, and further the physical properties of the release agent composition.

(1) Linear polyorganosiloxane (A)
The linear polyorganosiloxane (A) contained in the release agent composition according to one embodiment of the present invention has a linear siloxane skeleton, and has at least a reactive functional group composed of an alkenyl group in one molecule. Have two.

The reactive functional group is a functional group bonded to a silicon atom constituting the siloxane skeleton, and may be bonded to the terminal silicon of the linear polyorganosiloxane (A), or to a silicon other than the terminal silicon. It may be bonded. From the viewpoint of increasing the reactivity of the reactive functional group, the reactive functional group is preferably bonded to the terminal silicon. Two or more reactive functional groups may be bonded to the same silicon or different silicon. From the viewpoint of facilitating production, it may be preferable that two or more reactive functional groups are bonded to the same silicon.

There may be 3 or more reactive functional groups in one molecule. The more reactive functional groups, the more easily the reaction with the crosslinking agent (C) described later proceeds, and the density of the crosslinked structure contained in the crosslinked product formed from the release agent composition is likely to increase. In addition, if the number of reactive functional groups contained in one molecule is excessively large, a secondary action (for example, a change in solubility in a solvent) may occur, and such action may cause the stability of the release agent composition. In some cases, it is preferable to keep it to such an extent that it does not affect the above.

The type of alkenyl group that can be a component of the reactive functional group is not particularly limited. Specific examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, and an octenyl group, and among them, a vinyl group is particularly preferable.

The reactive functional group may be composed of one type of functional group or may be composed of a plurality of types of functional groups.

In the present specification, a functional group other than the reactive functional group of the linear polyorganosiloxane (A) (here, a hydrogen atom or a halogen atom is also positioned as a kind of functional group) is referred to as a non-reactive functional group. . Accordingly, silicon constituting the siloxane skeleton of the linear polyorganosiloxane (A) is bonded to a reactive functional group or a non-reactive functional group other than oxygen for bonding a siloxane bond.

The specific type of the non-reactive functional group that the linear polyorganosiloxane (A) has is not limited. As described above, it may be a hydrogen atom or a halogen atom, or may be an alkyl group or an aryl group. From the viewpoint of enhancing the ease of dissolution in the solvent (D), examples of preferable non-reactive functional groups include alkyl groups having 1 to 12 carbon atoms. Specific examples of such an alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and an octyl group.

The linear polyorganosiloxane (A) is a ratio of the number of reactive functional groups per unit mass (unit: mol / g) to the number of non-reactive functional groups per unit mass (unit: mol / g). (Also referred to as “reactive functional group ratio” in the present specification) is preferably 0.0002 or more and 0.2 or less. When the reactive functional group ratio is excessively low, the possibility that the linear polyorganosiloxane (A) is difficult to form a crosslinked structure with the crosslinking agent (C) increases. In addition, when the reactive functional group ratio is excessively low, the density of the crosslinked structure existing in the release layer formed from the release agent composition (this specification) even if the crosslinked structure is formed with the crosslinking agent (C) (It is also referred to as “crosslinking density” in the document), and it may be difficult to obtain appropriate mechanical properties. On the other hand, when the ratio of reactive functional groups is excessively high, the pot life of the release agent composition becomes excessively short, handling properties decrease, and the crosslink density of the release layer is excessively high. It may be difficult to obtain.

The reactive functional group ratio is 0.0005 or more and 0.1 or less from the viewpoint of facilitating making the mechanical properties of the release layer formed from the release agent composition within an appropriate range while enhancing the handleability. Is more preferably 0.001 or more and 0.05 or less, and particularly preferably 0.002 or more and 0.02 or less.

The linear polyorganosiloxane (A) has a polystyrene-equivalent weight average molecular weight (Mw) of preferably from 30,000 to 3,000,000, and preferably from 100,000 to 1,000,000. Is more preferably 150,000 or more and 300,000 or less. When the weight average molecular weight (Mw) in terms of polystyrene of the linear polyorganosiloxane (A) is excessively low, the possibility that the crosslinking density of the release agent layer becomes excessively high is increased. When the weight average molecular weight (Mw) in terms of polystyrene of the linear polyorganosiloxane (A) is excessively high, the viscosity of the release agent composition becomes excessively high, and the possibility that the handleability is lowered increases.

In this specification, the value of polystyrene-equivalent weight average molecular weight (Mw) is a value measured by a gel permeation chromatography (GPC) method (polystyrene standard). The measurement by such a method includes, for example, a high-speed GPC device “HLC-8121GPC / HT” manufactured by Tosoh Corporation and two GPC columns “Shodex GPC HT-806M” manufactured by Showa Denko, and a differential as a detector. A refractometer is used. As other measurement conditions, measurement can be performed with a measurement solvent: o-dichlorobenzene, an oven temperature: 135 ° C., and a sample concentration: 0.2% (w / v).

(2) Branched organosiloxane oligomer (B)
The branched organosiloxane oligomer (B) is a compound having a branched chain containing an organosiloxane skeleton, and is represented by the following general formula (a).

In the formula (a), q, r, s, and t are integers of 1 or more. At least two of R are alkenyl groups. Examples of the alkenyl group include a vinyl group, an allyl group, a propenyl group, a butenyl group, a pentenyl group, a hexenyl group, a heptenyl group, and an octenyl group. Among them, a vinyl group is particularly preferable. The functional group other than the alkenyl group in R (also referred to as “non-alkenyl group” in the present specification) is not limited, but in a preferred example, it is an alkyl group having 1 to 12 carbon atoms, such as a methyl group, an ethyl group, A propyl group, a butyl group, a pentyl group, a hexyl group, an octyl group and the like can be mentioned, and a methyl group is preferable. Each R may be the same or different.

The branched organosiloxane oligomer (B) has a function of reducing the viscosity of the release agent composition.
The branched organosiloxane oligomer (B) has at least two alkenyl groups in one molecule, and the site where the alkenyl group is present may be a main chain or a branched chain, Both may be used.

The branched organosiloxane oligomer (B) is a ratio of the number of reactive functional groups per unit mass (unit: mol / g) to the number of non-alkenyl groups per unit mass (unit: mol / g) (this specification). (Also referred to as “alkenyl group ratio”) is preferably 0.0002 or more and 0.2 or less. When the alkenyl group ratio is excessively low, the possibility that the branched organosiloxane oligomer (B) is difficult to form a crosslinked structure with the crosslinking agent (C) increases. Further, when the alkenyl group ratio is excessively low, even if a crosslinking structure is formed with the crosslinking agent (C), the crosslinking density of the release layer is low, and it may be difficult to obtain appropriate mechanical properties. On the other hand, when the ratio of the alkenyl group is excessively high, the pot life of the release agent composition is excessively shortened, the handleability is lowered, and the crosslink density of the release layer is excessively high, thereby obtaining appropriate mechanical characteristics. May be difficult.

From the viewpoint of facilitating making the mechanical properties of the release layer formed from the release agent composition within an appropriate range while improving the handleability, the alkenyl group ratio is preferably 0.01 or more and 1 or less. It is more preferably 0.02 or more and 0.5 or less, and particularly preferably 0.05 or more and 0.2 or less.

The branched organosiloxane oligomer (B) has a polystyrene-equivalent weight average molecular weight (Mw) of preferably 3,500 or more and 350,000 or less, more preferably 7,000 or more and 200,000 or less, and 15 It is particularly preferable that the number is from 000 to 70,000. When the polystyrene-reduced weight average molecular weight (Mw) of the branched organosiloxane oligomer (B) is excessively low, or conversely excessively high, the thickness of the release agent layer formed from the release agent composition or the release surface (release) The uniformity of the surface property of the surface of the agent layer on the side opposite to the side facing the substrate tends to be lowered. Examples of methods for evaluating the surface properties of the peeled surface include confirming the presence or absence of pinholes and measuring the arithmetic average roughness Ra.

The mass ratio of the linear polyorganosiloxane (A) to the branched organosiloxane oligomer (B) (A / B, also referred to as “siloxane ratio” in this specification) is 1/9 or more and less than 9. preferable. As described above, the branched organosiloxane oligomer (B) lowers the viscosity of the release agent composition. Therefore, the lower the siloxane ratio, the easier it is to obtain a low viscosity release agent composition. However, when the siloxane ratio is excessively small, the uniformity of the thickness and surface properties of the release agent layer formed from the release agent composition tends to decrease. On the other hand, when the siloxane ratio is excessively large, it becomes easy to obtain a release film having a high peel strength against PVB, which will be described later, and the release agent layer formed from the release agent composition is less likely to have excellent release properties. From the viewpoint of more stably realizing the reduction of the viscosity of the release agent composition and improving the surface properties of the release agent layer, the siloxane ratio is preferably 1/6 or more, and is 1/4 or more. More preferably, it is particularly preferably 1/3 or more. From the viewpoint of more stably realizing that the release agent layer formed from the release agent composition is excellent in releasability, the siloxane ratio is preferably 6 or less, more preferably 4 or less, Particularly preferred is 3 or less.

(3) Crosslinking agent (C)
The crosslinking agent (C) contained in the release agent composition according to one embodiment of the present invention is obtained by crosslinking the linear polyorganosiloxane (A) and / or the branched organosiloxane oligomer (B). Stable release properties can be imparted to the release agent layer.

The crosslinking agent (C) is not particularly limited as long as it can crosslink the linear polyorganosiloxane (A) and the branched organosiloxane oligomer (B). Other than the linear polyorganosiloxane (A) and the branched organosiloxane oligomer (B), polyorganosiloxane having at least two hydrogen atoms bonded to silicon atoms in one molecule is preferable. Examples of such polyorganosiloxane include dimethylhydrogensiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, trimethylsiloxy group end-capped dimethylsiloxane-methylhydrogensiloxane copolymer, and trimethylsiloxy group end-capped methylhydrol. Examples include polyorganohydrogensiloxanes such as genpolysiloxane and poly (hydrogensilsesquioxane).

The polystyrene-converted weight average molecular weight (Mw) of the polyorganosiloxane as the crosslinking agent (C) is preferably 500 or more and 5,000 or less, and more preferably 500 or more and 2,000 or less.

The content of the crosslinking agent (C) in the release agent composition according to one embodiment of the present invention is the number of reactive functional groups of the linear polyorganosiloxane (A) and the branched organosiloxane oligomer (B). It is preferable that the number of crosslinkable functional groups such as hydrosilyl groups in the crosslinking agent (C) is 1.0 to 5.0 in terms of molar ratio with respect to the total number of alkenyl groups in More preferably, the amount is 1.5 or more and 4.0 or less, and particularly preferably 1.8 or more and 3.0 or less.

(4) Solvent (D)
The kind of the solvent (D) contained in the release agent composition according to one embodiment of the present invention is the above-mentioned linear polyorganosiloxane (A), branched organosiloxane oligomer (B) and crosslinking agent (C). And as long as arbitrary components, such as the catalyst (E) mentioned later, can be melt | dissolved appropriately, and a releasing agent composition can have an appropriate surface tension so that it may mention later, it will not specifically limit.

From the viewpoint of easily satisfying the above-mentioned requirements, particularly the surface tension requirements, the solvent (D) preferably contains an organic compound, more preferably a polar organic compound, and an aprotic polar organic material. It is particularly preferable to contain a compound. Examples of aprotic polar organic compounds include esters such as ethyl acetate and methyl propionate; ketones such as methyl isobutyl ketone (MIBK), methyl ethyl ketone (MEK), cyclohexanone and acetone; ethers such as diethyl ether and tetrahydrofuran; dimethyl Examples include sulfoxides such as sulfoxide.

Further, the solvent (D) may be an aromatic compound as long as the above requirement is satisfied. Specific examples of the aromatic compound include substituted benzenes such as toluene and xylene.
The solvent (D) may contain a nonpolar organic compound such as hexane and heptane as long as the above requirement is satisfied, or a protic polar organic compound such as alcohols such as ethanol and propanol. May be.

The solvent (D) may be composed of one type of compound or a plurality of types of compounds. In some cases, it is easier for the solvent (D) to satisfy the above-mentioned requirements, particularly the requirements related to the surface tension, when composed of a plurality of types of compounds. In this case, it is preferable to combine an aprotic polar organic compound and a nonpolar organic compound as the plurality of types of compounds.

(5) Optional component The release agent composition according to an embodiment of the present invention includes the linear polyorganosiloxane (A), the branched organosiloxane oligomer (B), the crosslinking agent (C), and the solvent (D). In addition, other components can be contained as necessary. Examples of such optional components include a catalyst (E), a reaction inhibitor, and an adhesion improver.

The catalyst (E) is not particularly limited as long as it can cure the release agent composition according to one embodiment of the present invention, and among them, a platinum group metal compound is preferable. Examples of the platinum group metal compounds include fine platinum, fine platinum adsorbed on a carbon powder carrier, chloroplatinic acid, alcohol-modified chloroplatinic acid, olefin complexes of chloroplatinic acid, palladium, rhodium and the like. . When the release agent composition according to one embodiment of the present invention contains such a catalyst (E), the curing reaction of the release agent composition can proceed more efficiently. The content of the catalyst (E) in the release agent composition according to one embodiment of the present invention is preferably about 500 to 3000 ppm with respect to the total amount of components other than the catalyst (E).

(6) Surface tension The release agent composition according to an embodiment of the present invention has a surface tension measured under an environment of 23 ° C. and a relative humidity of 50% of less than 23.0 mN / m. Thus, when the surface tension of a release agent composition is low, it becomes possible to suppress that the coating property of a release agent composition and the surface property of the obtained release agent layer fall. Specifically, when a release agent composition is applied on a base film to form a release film composed of a base film and a release agent layer, pinholes are formed in the release agent layer of the obtained release film. Hard to occur. In addition, the release agent layer is not formed on the base film, and a portion where the base film is exposed (also referred to as an “unformed portion” in this specification) hardly occurs.

From the viewpoint of facilitating the formation of a release agent layer having excellent surface property uniformity, the release agent composition according to an embodiment of the present invention was measured in an environment of 23 ° C. and 50% relative humidity. The surface tension is preferably 22.8 mN / m or less, more preferably 22.6 mN / m or less, and particularly preferably 22.4 mN / m or less. From the viewpoint of facilitating formation of a release agent layer having excellent surface property uniformity, the lower limit of the surface tension is not set. When the surface tension is excessively low, the leveling property of the coating film of the release agent composition on the base film tends to be lowered when the release agent composition is applied on the base film. The surface tension of the release agent layer obtained from such a coating film may be 14 mN / m or more because the surface properties of the release surface may not be uniform because pinholes may occur. Preferably, it is more preferably 16 mN / m or more, and particularly preferably 18 mN / m or more.

(7) Viscosity The release agent composition according to one embodiment of the present invention has a viscosity measured in an environment of 23 ° C. of 0.48 mPa · s or more. When the viscosity is 0.48 mPa · s or more, the surface property uniformity of the release surface of the release agent layer formed from the release agent composition can be enhanced. Specifically, the arithmetic average roughness Ra (JIS B0601: 2013 (ISO 4287: 1997, Amd1: 2009)) of the release surface of the release agent layer is easily set to less than 15.5 nm. From the viewpoint of facilitating the reduction of the arithmetic average roughness Ra of the release surface of the release agent layer, the above viscosity is preferably 0.60 mPa · s or more, and more preferably 0.65 mPa · s or more. Preferably, it is 0.70 mPa · s or more. In addition, from the viewpoint of coating suitability, the viscosity of the release agent composition is preferably 3.0 mPa · s or less, more preferably 2.0 mPa · s or less, and particularly preferably 1.2 mPa · s or less.

2. Release Film The release film according to one embodiment of the present invention includes a base film and a release agent layer laminated on one main surface of the base film.

(1) Base film There is no restriction | limiting in particular as a base film with which a peeling film is equipped, Arbitrary things can be suitably selected and used from a conventionally well-known thing. Examples of such a base film include films made of polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene and polymethylpentene, polycarbonates, and plastics such as polyvinyl acetate. Alternatively, it may be a multilayer of two or more layers of the same type or different types. Among these, a polyester film is preferable, a polyethylene terephthalate film is particularly preferable, and a biaxially stretched polyethylene terephthalate film is more preferable. Since the polyethylene terephthalate film hardly generates dust or the like during processing or use, for example, it is possible to effectively prevent a ceramic slurry coating failure due to dust or the like. Furthermore, the effect which prevents the defect in a coating process, etc. can be heightened by performing an antistatic process to a polyethylene terephthalate film.

In addition, in this base film, for the purpose of improving the adhesion with the release agent layer provided on the surface, one or both surfaces are subjected to surface treatment by an oxidation method or a concavo-convex method or a primer treatment as desired. be able to. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, ultraviolet irradiation treatment, and the like. Examples include a thermal spraying method. These surface treatment methods are appropriately selected according to the type of the base film, but generally, a corona discharge treatment method is preferably used from the viewpoints of effects and operability.
The thickness of the base film is usually 10 to 300 μm, preferably 15 to 200 μm, and particularly preferably 20 to 125 μm.

(2) Release agent layer The release agent layer with which the release film which concerns on one Embodiment of this invention is provided is formed with the release agent composition mentioned above. In a specific example, the release agent layer includes a linear polyorganosiloxane (A) having at least two reactive functional groups composed of alkenyl groups in one molecule and an organosiloxane skeleton in one molecule. It contains a crosslinked product formed from a release agent composition containing a branched organosiloxane oligomer (B) having at least two alkenyl groups and a crosslinking agent (C).

The release agent layer is formed by applying a release agent composition to one surface of the base film, and then drying and curing. The application method is not limited, and for example, a known method such as gravure coating, bar coating, spray coating, spin coating, knife coating, roll coating, or die coating may be applied.

The coating film of the release agent composition applied as described above and formed on the base film is preferably heat-treated to promote a crosslinking reaction in the release agent composition. In the case of heat treatment, the heating temperature is preferably in the range of about 90 ° C. to 140 ° C., and the heating time is preferably in the range of about 10 seconds to 120 seconds. By this heat treatment or the like, the solvent (D) contained in the coating film of the release agent composition can be volatilized.

The thickness of the release agent layer provided in the release film according to an embodiment of the present invention is not particularly limited. It is preferably in the range of 0.01 μm to 3 μm, more preferably in the range of 0.03 μm to 1 μm. When the thickness of the release agent layer is less than 0.01 μm, the function as the release agent layer may not be sufficiently exhibited depending on the material constituting the release agent layer. On the other hand, when the thickness of the release agent layer exceeds 3 μm, when the release film is wound into a roll to form a wound body, blocking may occur, resulting in a problem in feeding.

In addition, the release film according to an embodiment of the present invention preferably has no pinholes or unformed portions. Since the release agent layer according to an embodiment of the present invention is formed from a release agent composition whose surface tension is appropriately controlled, pinholes and unformed portions are less likely to occur.

(3) Release surface It is preferable that arithmetic mean roughness Ra of the release surface of the release agent layer with which the release film which concerns on one Embodiment of this invention is provided is less than 15.5 nm. When the arithmetic average roughness Ra of the release surface is less than 15.5 nm, the ease of use of the release film can be increased. One specific example of ease of use of the release film is ease of formation of the green sheet. When the arithmetic average roughness Ra of the release surface of the release agent layer provided in the release film according to one embodiment of the present invention is less than 15.5 nm, the uniformity of the film thickness of the green sheet formed on the release film is Get higher. Furthermore, even if the green sheet to be formed is a thin film having a thickness of about 1 μm, the obtained green sheet has a high uniformity of film thickness, and problems such as pinholes are unlikely to occur. From the viewpoint of more stably increasing the ease of use of the release film, the arithmetic average roughness Ra of the release surface of the release agent layer provided in the release film according to one embodiment of the present invention is preferably 14 nm or less, It is more preferably 12 nm or less, and particularly preferably 10 nm or less.

(4) Pvb peeling force A peel formed from a base material made of a polyester film having a thickness of 31 μm and a release agent composition according to an embodiment of the present invention laminated on one surface of the base material. A release film comprising an agent layer is prepared, and a laminate film obtained by laminating a 3 μm-thick resin film made of polyvinyl butyral on the release surface of the release film is fixed to the release film. The peel force (also referred to as “PVB peel force against” in this specification) measured by performing a test of peeling at a peel angle of 180 ° is 65 mN / 40 mm or less. Polyvinyl butyral is a common material as a binder component of a green sheet, and when the peel strength against PVB is in the above range, a release agent layer having a release surface having good peelability with respect to the green sheet is provided. It is possible to obtain. From the viewpoint of more stably obtaining good peelability for the green sheet, the peel strength against PVB is preferably 60 mN / 40 mm or less, more preferably 55 mN / 40 mm or less, and 50 mN / 40 mm or less. Particularly preferred.

3. Method for Using Release Film The method for using the release film described above is not limited. Hereinafter, the case where it uses for manufacture of a green sheet is demonstrated as a specific example.

First, using a slot die coating method, a doctor blade method, or the like, ceramic slurry is applied to the release surface of the release film according to an embodiment of the present invention to obtain a ceramic slurry coating. A ceramic green sheet can be formed by drying the coating film of the obtained ceramic slurry. At this time, since the release agent layer of the release film according to one embodiment of the present invention is less likely to cause pinholes and unformed portions, even when a thin ceramic green sheet with low strength is formed on the release agent layer, The ceramic green sheet can be peeled from the release agent layer without causing problems such as breakage. Thus, according to the peeling film which concerns on this embodiment, while being excellent in the coating property of a ceramic slurry, it is excellent also in the peeling property of a ceramic green sheet.

The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

For example, another layer such as an antistatic layer may be provided between the surface of the substrate opposite to the side facing the release agent layer or between the substrate and the release agent layer.

Hereinafter, the present invention will be described more specifically with reference to examples and the like, but the scope of the present invention is not limited to these examples and the like.

[Example 1]
Addition reaction type silicone resin release agent containing linear polyorganosiloxane (A) (“KS-847H” manufactured by Shin-Etsu Chemical Co., Ltd., solid content concentration 30%, hereinafter, the release agent is referred to as “first release agent”. )) And 25 parts by mass (solid content concentration of 30) of addition reaction type silicone resin release agent containing the branched organosiloxane oligomer (B) (hereinafter referred to as “second release agent”). %). A mixed solvent composed of ethyl acetate and cyclohexanone (mixing ratio is ethyl acetate: cyclohexanone = 90 parts by mass: 10 parts by mass) was prepared as the solvent (D). A mixture of the first release agent and the second release agent was diluted with a solvent (D) to prepare a liquid composition having a solid content concentration of 1.5% by mass. The first release agent contained a crosslinking agent (C). 3 parts by mass of a platinum-based catalyst (“PL-50T” manufactured by Shin-Etsu Chemical Co., Ltd.) was added to 100 parts by mass of this liquid composition to obtain a release agent composition. In addition, the polystyrene conversion weight average molecular weight (Mw) of the linear polyorganosiloxane (A) was 288,000, and the polystyrene conversion weight average molecular weight (Mw) of the branched organosiloxane oligomer (B) was 36,000.

Thickness after drying the obtained release agent composition using a bar coater on one side (arithmetic mean roughness Ra: 7 nm, maximum peak height Rp: 26 nm) of a biaxially stretched polyethylene terephthalate film having a thickness of 31 μm Is uniformly applied so as to be 0.06 μm (solid content coating amount 0.06 g / m ² ), and dried at 130 ° C. for 1 minute by a drier, whereby a 300 m long release film is used as a wound body Obtained. The arithmetic average roughness Ra and the maximum peak height Rp of the biaxially stretched polyethylene terephthalate film are values measured according to JIS B0601: 2013 (ISO 4287: 1997).

[Examples 2 to 12 and Comparative Examples 1 to 5]
In the preparation of the release agent composition of Example 1, except that the mixing ratio of the first release agent and the second release agent was changed to the ratio shown in Table 1 or the composition of the mixed solvent was changed. In the same manner as in Example 1, a release agent composition was prepared. Hereinafter, the same operation as in Example 1 was performed to obtain a wound film of a release film.
In Table 1, “MIBK” means methyl isobutyl ketone, and “MEK” means methyl ethyl ketone. In addition, the display in parentheses in the column of the solvent is a mixing ratio when the solvent is a mixed solvent.

[Test Example 1] <Measurement of surface tension of release agent composition>
For each of the release agent compositions prepared in Examples and Comparative Examples, 10 g was poured into a glass petri dish having a diameter of 7.5 cm, and a surface tension meter (“FACE CBVP type surface tension meter V3” manufactured by Kyowa Interface Science Co., Ltd.) The surface tension (unit: mN / m) of the release agent composition was measured by immersing a 10 mm × 30 mm platinum plate in the release agent composition in an environment of 23 ° C. and 50% relative humidity. The results are shown in Table 2.

[Test Example 2] <Measurement of viscosity of release agent composition>
For each of the release agent compositions prepared in the examples and comparative examples, 50 g was poured into a glass bottle (70 ml), and the liquid temperature and The viscosity (unit: mPa · s) of the composition was measured while stirring the release agent composition with a stirrer in an environment where the room temperature was 23 ° C. The results are shown in Table 2.

[Test Example 3] <Measurement of peel strength of peelable film against PVB>
To 100 parts by mass of polyvinyl butyral (“S-LEC BL-S” manufactured by Sekisui Chemical Co., Ltd.), which is a common binder component for green sheets, is a mixture of toluene and ethanol (mixing ratio is toluene: ethanol = 60 parts by mass: 40 (Mass part) 400 parts by mass was added and stirred with a disper until uniformly dissolved to prepare a polyvinyl butyral coating solution.

In order to reduce the influence of the residual Si—H groups in the release agent layer on the release force, the release films prepared in the examples and comparative examples were allowed to stand for 24 hours in an environment of 70 ° C. and 50% relative humidity. The release film after standing was used as a measurement target of the release force. Using the applicator, the polyvinyl butyral coating solution prepared as described above is uniformly applied on each release film that has been allowed to stand as described above so that the thickness after drying is 3 μm, followed by drying treatment. Thus, a release film with polyvinyl butyral was prepared.

Next, an adhesive tape (“31B tape” manufactured by Nitto Denko Corporation) was bonded to the surface of the release film with polyvinyl butyral on the polyvinyl butyral side. After being left in an environment of 23 ° C. and 50% relative humidity for 24 hours, it was cut into 40 mm × 100 mm to obtain a test piece in which a release film, a layered body made of polyvinyl butyral, and an adhesive tape were laminated in this order. .

Using a high-speed peel tester (manufactured by Tester Sangyo Co., Ltd.), it is necessary to peel off the peeled film side at a peel angle of 180 ° in an environment of 23 ° C. and 50% relative humidity at a speed of 100 m / min. The maximum force (unit: mN / 40 mm) was taken as the PVB peel force. The results are shown in Table 2. When the peel strength against PVB is 65 mN / 40 mm or less, it can be determined that the peelable film has good peelability.

[Test Example 4] <Measurement of the number of pinholes>
Each winding body produced in the Examples and Comparative Examples was fed out to prepare a release film having a length of 3 m. Five evaluation samples having an A4-sized release surface were collected from an arbitrary position of the release film. The peeled surfaces of these evaluation samples were visually observed, and the number of visually recognized pinholes was measured. The results are shown in Table 2. If the number of visually recognized pinholes is 5 or less, it can be determined from this point of view that the peeled surface has particularly good surface properties. When the number of pinholes is 6 or more and 11 or less, it can be determined from this point of view that the surface is a peeled surface having good surface properties. When the number of pinholes is 12 or more, it can be determined that this is not a release surface having good surface properties.

[Test Example 5] <Measurement of arithmetic average roughness Ra>
The arithmetic average roughness Ra (JIS B0601: 2013 (ISO 4287: 1997, Amd1: 2009)) of the peeling surface of the peeling film produced in the Example was measured. The results are shown in Table 2. When the arithmetic average roughness Ra of the peeled surface is less than 14.0 nm, it can be determined from this point of view that the peeled surface has particularly good surface properties. When the arithmetic average roughness Ra of the peeled surface is 14.0 nm or more and less than 15.5 nm, it can be determined from this point of view that the peeled surface has good surface properties. When the arithmetic average roughness Ra of the peeled surface is 15.5 nm or more, it can be determined that this is not a peeled surface having good surface properties from this viewpoint.

As can be seen from Table 2, the release film according to the example of the present invention, which is an example satisfying the conditions of the present invention, was excellent in surface properties and had good releasability.

The release agent composition according to the present invention is suitably used as a composition for forming a release agent layer of a release film of a thin green sheet having a thickness of 1 μm or less.

Claims

A linear polyorganosiloxane (A) having at least two reactive functional groups consisting of alkenyl groups in one molecule; a branched organosiloxane oligomer (B) having at least two alkenyl groups in one molecule; Containing a crosslinking agent (C) and a solvent (D),
A release agent composition having a surface tension measured under an environment of 23 ° C. and a relative humidity of 50% of less than 23.0 mN / m,
The release agent composition has a viscosity at 23 ° C. of 0.48 mPa · s or more,
A release film comprising a base material made of a polyester film having a thickness of 31 μm and a release agent layer formed from the release agent composition laminated on one surface of the base material is prepared. Measurement was performed on a laminate structure obtained by laminating a 3 μm-thick resin film made of polyvinyl butyral on the release surface, by fixing the resin film and peeling the release film at a peel angle of 180 °. A release agent composition having a release force of 65 mN / 40 mm or less.
The release agent composition according to claim 1, wherein a mass ratio of the linear polyorganosiloxane (A) to the branched organosiloxane oligomer (B) is 1/9 or more and 9 or less.
The release agent composition according to claim 1 or 2, wherein the solvent (D) contains an aprotic polar organic compound.
The release agent composition according to claim 3, wherein the solvent (D) is composed of a mixed solvent of an aprotic polar organic compound and a nonpolar organic compound.
A release film comprising a base film and a release agent layer laminated on one main surface of the base film,
The said release agent layer was formed from the release agent composition as described in any one of Claim 1 to 4, The release film characterized by the above-mentioned.
The release film according to claim 5, wherein an arithmetic average roughness Ra of the release surface of the release agent layer is less than 15.5 nm.