WO2016208469A1

WO2016208469A1 - Release film for ceramic green sheet production process

Info

Publication number: WO2016208469A1
Application number: PCT/JP2016/067796
Authority: WO
Inventors: 森　裕一; 佐藤　慶一
Original assignee: リンテック株式会社
Priority date: 2015-06-23
Filing date: 2016-06-15
Publication date: 2016-12-29
Also published as: CN107148348A; KR20180020946A; SG11201710776UA; TW201710085A; PH12017502383A1; JP2017007227A

Abstract

A release film 1 for a ceramic green sheet production process, comprising a base material 11 and a release agent layer 12 provided on one side of the base material 11. The release agent layer 12 comprises a release agent composition containing: a polyorganosiloxane having at least one hydroxyl group per molecule; and a melamine resin having a total acid value of 0.030-0.154 mg KOH/g. This release film 1 for a ceramic green sheet production process displays good release properties and has suppressed transfer of polyorganosiloxane from the release agent layer 12 to the ceramic green sheet.

Description

Release film for ceramic green sheet manufacturing process

The present invention relates to a release film used in a process for producing a ceramic green sheet.

Conventionally, in order to manufacture a multilayer ceramic product such as a multilayer ceramic capacitor or a multilayer ceramic substrate, a ceramic green sheet is formed, and a plurality of obtained ceramic green sheets are laminated and fired.

The ceramic green sheet is formed by coating a ceramic slurry containing a ceramic material such as barium titanate or titanium oxide on a release film. The release film is required to have releasability that allows the release film to be peeled off from the thin ceramic green sheet formed on the release film with an appropriate peeling force without causing cracks or breakage.

The release film is generally composed of a base material and a release agent layer provided on one surface of the base material. As the release agent layer, there is a layer made of an ultraviolet curable compound. This release agent layer is formed by applying a release agent composition containing an ultraviolet curable compound on a substrate and curing the composition by irradiation with ultraviolet rays. However, there are types of ultraviolet curable compounds whose curing is inhibited by oxygen. When such an ultraviolet curable compound is used, curing in the vicinity of the surface of the release agent layer on the side opposite to the substrate (surface in contact with the ceramic slurry / ceramic green sheet; hereinafter may be referred to as “release surface”). It may be insufficient. If the release agent layer is not sufficiently cured, the elasticity of the release agent layer is lowered. As a result, the peeling force required for peeling the release sheet from the ceramic green sheet formed on the release surface is increased.

On the other hand, Patent Document 1 discloses a release film provided with a release agent layer containing a thermosetting compound such as melamine resin and polysiloxane (polyorganosiloxane). In this release film, since the release agent layer contains polyorganosiloxane, the release force can be reduced to some extent. The melamine resin condenses by heating and can be cured without the above-described inhibition by oxygen. Therefore, the above-mentioned problem peculiar when an ultraviolet curable compound is used can be avoided.

In general, the “melamine resin” means a mixture containing at least one of a plurality of types of melamine compounds and a polynuclear product formed by condensation of one or more types of melamine compounds. In the present specification, the phrase “melamine resin” means the above mixture or an aggregate of one kind of melamine compounds. Furthermore, in this specification, what the said melamine resin hardened shall be called "melamine hardened | cured material."

JP 2004-82370 A

By the way, when the multilayer ceramic product is manufactured, there may be a deviation in the plane direction between the laminated ceramic green sheets. Such a shift is considered to be caused by, for example, accumulation of a shift in the stacking position in the stacking process, a shift due to thermocompression bonding in the thermocompression bonding process, a shift due to shrinkage in the sintering process, and the like.

When a ceramic green sheet is formed using a release film having a release agent layer containing polyorganosiloxane as described in Patent Document 1, the migration of the polyorganosiloxane from the release agent layer to the ceramic green sheet is caused. It is likely to occur. When a multilayer ceramic product is manufactured by laminating a plurality of ceramic green sheets to which polyorganosiloxane has migrated, the adhesive strength between the ceramic green sheets is reduced, and the above-described deviation is likely to occur. As a result, the yield in manufacturing the multilayer ceramic product is reduced. For this reason, there is a need for a release film with less migration of the polyorganosiloxane to the ceramic green sheet.

The present invention has been made in view of such a situation, and exhibits a good releasability and is a peel for ceramic green sheet manufacturing process in which the migration of polyorganosiloxane from the release agent layer to the ceramic green sheet is suppressed. The object is to provide a film.

In order to achieve the above object, first, the present invention is 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, the release agent The layer was formed from a release agent composition containing a polyorganosiloxane having at least one hydroxyl group in one molecule and a melamine resin having a total acid value of 0.030 to 0.154 mg KOH / g. Provided is a release film for a ceramic green sheet manufacturing process (Invention 1).

According to the above invention (Invention 1), the release agent layer comprises a polyorganosiloxane having at least one hydroxyl group in one molecule and a melamine resin having a total acid value of 0.030 to 0.154 mg KOH / g. By being formed from the contained release agent composition, it exhibits good release properties and suppresses migration of polyorganosiloxane from the release agent layer to the ceramic green sheet.

In the above invention (Invention 1), the polyorganosiloxane preferably has at least one organic group selected from a polyester group and a polyether group in one molecule (Invention 2).

In the above inventions (Inventions 1 and 2), at least one of the hydroxyl groups is preferably present at the end of the polyorganosiloxane (Invention 3).

In the above inventions (Inventions 1 to 3), the polyorganosiloxane preferably has a weight average molecular weight of 1,000 to 300,000 (Invention 4).

In the above inventions (Inventions 1 to 4), the melamine resin has the following general formula (a):

(In the formula, X represents —H, —CH ₂ —OH, or —CH ₂ —O—R, and may be the same or different. R represents a carbon number of 1-8. Each represents the same or different alkyl group, and at least one X is —CH ₂ —OH.)
Or a polynuclear product obtained by condensing two or more of the compounds (Invention 5).

In the above inventions (Inventions 1 to 5), the release agent composition preferably further contains an acid catalyst (Invention 6).

In the above inventions (Inventions 1 to 6), the thickness of the release agent layer is preferably 0.1 to 3 μm (Invention 7).

In the above inventions (Inventions 1 to 7), it is preferable to further comprise a resin layer located between the substrate and the release agent layer (Invention 8).

The release film for a ceramic green sheet production process according to the present invention exhibits good releasability and suppresses migration of polyorganosiloxane from the release agent layer to the ceramic green sheet.

It is sectional drawing of the peeling film for ceramic green sheet manufacturing processes which concerns on one Embodiment of this invention. It is sectional drawing of the peeling film for ceramic green sheet manufacturing processes which concerns on another embodiment of this invention.

Hereinafter, embodiments of the present invention will be described.
[Peeling film for ceramic green sheet manufacturing process]
As shown in FIG. 1, a release film 1 A for a ceramic green sheet manufacturing process according to the first embodiment (hereinafter sometimes simply referred to as “release film 1 A”) is a base material 11 and one of the base materials 11. And a release agent layer 12 laminated on the surface (the upper surface in FIG. 1).

As shown in FIG. 2, the release film 1 B for the ceramic green sheet manufacturing process according to the second embodiment (hereinafter sometimes simply referred to as “release film 1 B”) includes the base material 11 and the base material 11. A resin layer 13 laminated on one surface (upper surface in FIG. 2) and a release agent layer 12 laminated on a surface opposite to the base 11 of the resin layer 13 (upper surface in FIG. 2). Is done.

1. Release Agent Layer The release agent layer 12 of the

release films

1A and 1B comprises a polyorganosiloxane having at least one hydroxyl group in one molecule and a melamine resin having a total acid value of 0.030 to 0.154 mg KOH / g. It is formed from the contained release agent composition.

In the

release films

1A and 1B, the release agent composition for forming the release agent layer 12 contains polyorganosiloxane. For this reason, the surface free energy in the peeling surface of the release agent layer 12 falls moderately. Furthermore, the release agent composition contains a melamine resin. For this reason, the release agent composition can be sufficiently cured by heating, and the formed release agent layer 12 has sufficient elasticity. By these, the peeling force at the time of peeling

peeling film

1A, 1B from the ceramic green sheet shape | molded on the peeling surface of

peeling film

1A, 1B falls moderately, and favorable peelability is exhibited.

In the

release films

1A and 1B, the total acid value of the melamine resin contained in the release agent composition for forming the release agent layer 12 is 0.030 to 0.154 mg KOH / g. This means that the melamine resin has a relatively large number of acidic functional groups. This acidic functional group is derived mainly from the hydroxyl group of the methylol group (—CH ₂ —OH) in the melamine resin. On the other hand, the polyorganosiloxane contained in the release agent composition also has at least one hydroxyl group in one molecule. When such a release agent composition is cured to form the release agent layer 12, a structure in which the melamine resin and the polyorganosiloxane are chemically bonded to each other at the hydroxyl groups and the polyorganosiloxane is fixed to the cured melamine is formed. The For this reason, free movement of the polyorganosiloxane in the release agent layer 12 is restricted. Therefore, when a ceramic green sheet is formed on the release surfaces of the

release films

1A and 1B, the migration of the polyorganosiloxane from the release agent layer 12 to the ceramic green sheet is suppressed. Thereby, when the ceramic green sheets shape | molded using

peeling film

1A, 1B are laminated | stacked, the adhesive force of ceramic green sheets improves, and generation | occurrence | production of the gap between ceramic green sheets is suppressed.

(1) Melamine resin In the release agent composition for forming the release agent layer 12, the total acid value of the melamine resin is 0.030 to 0.154 mg KOH / g, and 0.032 to 0.100 mg KOH / g. It is preferably 0.035 to 0.070 mg KOH / g. The total acid value of the melamine resin means the mass (mg) of potassium hydroxide necessary to completely react the group capable of reacting with potassium hydroxide contained in 1 g of melamine resin. In this specification, the total acid value of a melamine resin shall be represented not by a theoretical value but by an actual measured value. Here, the group capable of reacting with potassium hydroxide is a methylol group (—CH ₂ —OH). On the other hand, imino groups (—NH—) and alkyl ether groups (—CH ₂ —OR) do not react with potassium hydroxide. In addition, the specific measuring method of the total acid value of a melamine resin is as showing in the test example mentioned later. When the total acid value is less than 0.030 gKOH / g, the number of hydroxyl groups in the melamine resin becomes insufficient, and the reaction between the polyorganosiloxane and the melamine resin does not proceed sufficiently. As a result, in the formed release agent layer 12, the amount of polyorganosiloxane that is not fixed to the melamine cured product increases, and migration of the polyorganosiloxane to the ceramic green sheet is likely to occur. On the other hand, when the total acid value exceeds 0.154 mg KOH / g, an acidic group that does not participate in the above condensation reaction and the condensation reaction between melamine resins is excessively present, and it becomes difficult to control the crosslinking rate. As a result, there is a concern that the quality of the ceramic green sheet formed on the peeled surface is degraded.

Specifically, the melamine resin preferably contains a melamine compound represented by the following general formula (a) or a polynuclear product obtained by condensing two or more of the melamine compounds.

In formula (a), X represents —H, —CH ₂ —OH, or —CH ₂ —O—R. These groups constitute reactive groups in the condensation reaction between the melamine compounds. Specifically, the —NH group formed when X becomes H can undergo a condensation reaction between the —N—CH ₂ —OH group and the —N—CH ₂ —R group. Both the —N—CH ₂ —OH group formed when X becomes —CH ₂ —OH and the —N—CH ₂ —R group formed when X becomes —CH ₂ —R are both , —NH group, —N—CH ₂ —OH group and —N—CH ₂ —R group can be subjected to a condensation reaction. In formula (a), at least one X is —CH ₂ —OH. The presence of at least one —CH ₂ —OH group enables reaction between the hydroxyl group contained in the group and the hydroxyl group of the polyorganosiloxane, and the migration of the polyorganosiloxane is suppressed as described above. When the melamine resin contains a polynuclear product obtained by condensing the melamine compound, the polynuclear product itself has at least one —CH ₂ —OH group.

In the above —CH ₂ —O—R group, R 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 the alkyl group having 1 to 8 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, a hexyl group, and an octyl group, and a methyl group is particularly preferable.

The above Xs may be the same or different. Moreover, said R may be the same respectively, and may differ.

Melamine compounds generally include a full ether form in which all Xs are —CH ₂ —O—R, imino methylol in which at least one X is —CH ₂ —OH and at least one X is H. type, at least one X is _-CH 2 -OH and and and methylol type is H X is absent, and, at least one X is not present _-CH 2 -OH a and a H H imino There are types such as types. In the

release films

1A and 1B, the melamine resin is an imino / methylol type from the viewpoint that curling is easily suppressed and the physical property that the total acid value is 0.030 to 0.154 mgKOH / g. Alternatively, it preferably contains a methylol type melamine compound. In particular, in the formula (a), it is preferable that more X is _-CH 2 -OH, in particular, the number of X is a _-CH 2 -OH is preferably at least two, In particular, at least three are preferable.

The melamine resin may contain a polynuclear product obtained by condensing 2 to 50 compounds represented by the above formula (a), and may contain a polynuclear product obtained by condensing 2 to 30 compounds. A polynuclear product formed by condensation of 10 may be included, and further, a polynuclear product formed by condensation of 2 to 5 may be included.

In the release agent composition for forming the release agent layer 12, the weight average molecular weight of the melamine resin is preferably 350 to 10000, particularly preferably 700 to 5000, and more preferably 1000 to 4000. Is preferred. When the weight average molecular weight is 350 or more, the crosslinking rate is stabilized, and a smoother release surface can be formed. On the other hand, when the weight average molecular weight is 10,000 or less, an excessive increase in the viscosity of the release agent composition is suppressed. Thereby, the applicability | paintability at the time of coating a release agent composition on the base material 11 will become favorable. In addition, the weight average molecular weight in this specification is the value of standard polystyrene conversion measured by the gel permeation chromatography (GPC) method.

(2) Polyorganosiloxane The polyorganosiloxane preferably has at least one hydroxyl group in one molecule. Further, the upper limit of the number of hydroxyl groups in one molecule of polyorganosiloxane is not particularly limited, but is 20 for example. Since the release agent layer 12 of the

release films

1A and 1B is formed of a release agent composition containing polyorganosiloxane, the release surface of the release agent layer 12 can exhibit good release properties. Further, since the polyorganosiloxane has the hydroxyl group, the polyorganosiloxane can be fixed to the cured melamine by a condensation reaction with the melamine resin. As a result, the migration of the polyorganosiloxane from the release agent layer 12 to the ceramic green sheet is suppressed.

The structure other than the hydroxyl group in the polyorganosiloxane is particularly limited as long as it does not inhibit the above-described peelability, the condensation reaction between the polyorganosiloxane and the melamine resin, and the condensation reaction between the melamine compounds contained in the melamine resin. It is not a thing. As the polyorganosiloxane, a polymer of a silicon-containing compound represented by the following general formula (b) can be used.

In the formula (b), m is an integer of 1 or more. At least one of R ¹ to R ⁸ is a hydroxyl group or an organic group having a hydroxyl group. In particular, at least one of R ³ to R ⁸ is preferably a hydroxyl group or an organic group having a hydroxyl group. That is, it is preferable that at least one of the hydroxyl group or the organic group having a hydroxyl group is present at the terminal of the polyorganosiloxane. When the hydroxyl group is present at the terminal, the polyorganosiloxane easily undergoes a condensation reaction with the melamine resin, and the migration of the polyorganosiloxane is effectively suppressed.

In the formula (b), at least one of the groups other than the hydroxyl group among R ¹ to R ⁸ is preferably an organic group. Here, when at least one of R ¹ to R ⁸ in formula (b) is a hydroxyl group, the other organic groups contained in R ¹ to R ⁸ may be an organic group having a hydroxyl group, or An organic group having no hydroxyl group may be used. On the other hand, when none of R ¹ to R ⁸ in formula (b) is a hydroxyl group, the other organic groups contained in R ¹ to R ⁸ are organic groups having a hydroxyl group. In the present specification, the “organic group” does not include an alkyl group described later. The polyorganosiloxane represented by the formula (b) preferably has at least one organic group having a hydroxyl group or an organic group having no hydroxyl group in one molecule, particularly preferably 1 to 10, more preferably It is preferable to have 1 to 5 pieces. Here, the organic group is preferably one or more organic groups selected from a polyester group and a polyether group. Both polyester groups and polyether groups may be present in one molecule. When a polyester group or a polyether group contains a hydroxyl group, the hydroxyl group may be present at the end of these organic groups, or may be present in the side chain of these organic groups. When the polyorganosiloxane has the above organic group, the polyorganosiloxane and the melamine resin are well mixed in the release agent composition, and the phase separation of these during the curing is suppressed. Thereby, the condensation reaction of the polyorganosiloxane and the melamine resin as described above proceeds well, and the migration of the polyorganosiloxane is effectively suppressed.

In the formula (b), among R ¹ to R ⁸ , groups other than those described above are preferably 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, and an octyl group, and a methyl group is particularly preferable.

R ¹ to R ⁸ may be the same or different. When a plurality of R ¹ and R ² are present, R ¹ and R ² may be the same or different from each other.

The weight-average molecular weight of the polyorganosiloxane is preferably 1000 to 300,000, particularly preferably 3000 to 100,000, and more preferably 4000 to 50,000. When the weight average molecular weight of the polyorganosiloxane is 1000 or more, the surface free energy on the release surface of the release agent layer 12 is moderately reduced, and the peeling force when peeling the

release films

1A and 1B from the ceramic green sheet is effective. Can be reduced. When the weight average molecular weight of the polyorganosiloxane is 300000 or less, an excessive increase in the viscosity of the release agent composition is suppressed, and the release agent composition can be easily applied to the substrate 11.

The content of the polyorganosiloxane in the release agent composition is preferably 0.05 to 15 parts by mass, particularly preferably 0.1 to 10 parts by mass with respect to 100 parts by mass of the melamine resin. Further, it is preferably 0.5 to 8 parts by mass. When the content of the polyorganosiloxane in the release agent composition is 0.05 parts by mass or more, the surface free energy of the release surface of the release agent layer 12 is sufficiently reduced, and an appropriate release force can be achieved. it can. On the other hand, when the content of the polyorganosiloxane in the release agent composition is 15 parts by mass or less, the content of the melamine resin can be ensured. Thereby, the elasticity of the release agent layer 12 is improved, and an appropriate peeling force can be achieved. In the

release films

1A and 1B, the migration of the polyorganosiloxane is suppressed due to the reaction between the polyorganosiloxane and the melamine resin as described above. For this reason, even if the release agent composition contains a relatively large amount of polyorganosiloxane, the migration of the polyorganosiloxane is sufficiently suppressed.

(3) Other components The release agent composition preferably further contains an acid catalyst. As examples of the acid catalyst, hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, phosphorous acid, p-toluenesulfonic acid and the like are preferable, and p-toluenesulfonic acid is particularly preferable. When the release agent composition contains an acid catalyst, the condensation reaction in the melamine resin proceeds efficiently.

The content of the acid catalyst in the release agent composition is preferably from 0.1 to 30 parts by weight, particularly preferably from 0.5 to 20 parts by weight, based on 100 parts by weight of the melamine resin. Is preferably 1 to 15 parts by mass.

The release agent composition may contain a crosslinking agent, a reaction inhibitor and the like in addition to the above components.

(4) Release agent layer thickness The release agent layer 12 preferably has a thickness of 0.1 to 3 μm, particularly preferably 0.2 to 2 μm, and more preferably 0.3 to 1.5 μm. It is preferable that When the thickness of the release agent layer 12 is 0.1 μm or more, the function as the release agent layer 12 can be effectively exhibited. In particular, when the release agent layer 12 containing the cured melamine is thicker than usual, the release agent layer 12 is more elastic and improved in peelability. Moreover, when the release agent layer 12 has a thickness of 3 μm or less, it is possible to suppress occurrence of blocking when the

release films

1A and 1B are wound into a roll. The thickness of the release agent layer 12 such as 0.1 to 3 μm is thicker than that of the normal release agent layer 12. Usually, as the thickness of the release agent layer 12 increases, the amount of migration of the polyorganosiloxane tends to increase, but in the release agent layer 12 of the

release films

1A and 1B, the reaction between the polyorganosiloxane and the melamine resin occurs. Therefore, even when the release agent layer 12 is thick, the migration of the polyorganosiloxane is sufficiently suppressed.

2. Base Material The base material 11 of the

release films

1A and 1B is not particularly limited as long as the release agent layer 12 or the resin layer 13 can be laminated. Examples of the base material 11 include films made of polyesters such as polyethylene terephthalate and polyethylene naphthalate, polyolefins such as polypropylene and polymethylpentene, plastics such as polycarbonate and polyvinyl acetate. These films may be a single layer or a multilayer of two or more layers of the same 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, by performing an antistatic treatment on the polyethylene terephthalate film, it is possible to increase the effect of preventing ignition due to static electricity when coating a ceramic slurry using an organic solvent or preventing defective coating.

Moreover, in this base material 11, for the purpose of improving the adhesiveness with the release agent layer 12 or the resin layer 13 provided on the surface, a surface treatment by an oxidation method, a concavo-convex method, or the like, if desired, on one side or both sides, Alternatively, primer treatment can be performed. Examples of the oxidation method include corona discharge treatment, plasma discharge treatment, chromium oxidation treatment (wet), flame treatment, hot air treatment, ozone, and ultraviolet irradiation treatment. Examples of the unevenness method include a sand blast method and a thermal spraying method. These surface treatment methods are appropriately selected depending on 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 substrate 11 is usually 10 to 300 μm, preferably 15 to 200 μm, and particularly preferably 20 to 125 μm.

3. Resin Layer The resin layer 13 provided on the release film 1B is located between the base material 11 and the release agent layer 12 as shown in FIG. By providing the resin layer 13 between the base material 11 and the release agent layer 12, irregularities on the surface of the base material 11 on the release agent layer 12 side are absorbed, and the roughness of the release surface of the release film 1B is reduced. Can do.

The resin forming the resin layer 13 is not particularly limited, and examples thereof include melamine resin, epoxy resin, phenol resin, urea resin, polyester resin, urethane resin, acrylic resin, polyimide resin, and benzoxazine resin. Among these, it is preferable to form the resin layer 13 with a melamine resin. By forming the resin layer 13 with a melamine resin, the adhesive force between the resin layer 13 and the base material 11 and between the resin layer 13 and the release agent layer 12 is improved. Furthermore, the elasticity on the peeling surface side of the release film 1B is improved, and the peeling force when peeling the release film 1B from the ceramic green sheet is appropriately reduced.

The melamine resin for forming the resin layer 13 is not particularly limited. However, from the viewpoint of suppressing the shrinkage of the resin layer 13 itself, the melamine resin used for forming the release agent layer 12 is preferably used as the melamine resin for the resin layer 13. That is, it is preferable to form the resin layer 13 using the composition containing the above-mentioned melamine resin.

Moreover, the resin layer 13 may contain components other than the melamine resin together with the melamine resin, such as an epoxy resin, a phenol resin, a urea resin, a polyester resin, a urethane resin, an acrylic resin, a polyimide resin, and a benzoxazine resin. A resin may be contained. When the resin layer 13 contains these resins, the content thereof is preferably 1 to 200 parts by mass, particularly preferably 10 to 150 parts by mass, with respect to 100 parts by mass of the melamine resin. It is preferably from ˜100 parts by mass. Moreover, the resin layer 13 may contain a crosslinking agent, a reaction inhibitor, an adhesion improver, and the like.

The thickness of the resin layer 13 is usually 0.1 to 3 μm, preferably 0.2 to 2 μm, and particularly preferably 0.3 to 1.5 μm.

4. Physical properties of release film for ceramic green sheet manufacturing process The release force required to release the

release films

1A and 1B from the ceramic green sheet formed on the release surface of the

release films

1A and 1B should be set as appropriate. However, it is preferably 2.5 to 50 mN / 20 mm, and more preferably 5 to 25 mN / 20 mm. The release agent layer in the

release films

1A and 1B is formed of a release agent composition containing the melamine resin and polyorganosiloxane. Therefore, it is possible to appropriately set the peeling force as 2.5 to 50 mN / 20 mm.

When the ceramic green sheet is formed using the

release films

1A and 1B, the migration of the polyorganosiloxane from the release agent layer 12 to the ceramic green sheet is suppressed. Specifically, after the ceramic green sheet was formed on the release surfaces of the

release films

1A and 1B, when the ceramic green sheet was released from the

release films

1A and 1B, it was in contact with the release surface of the ceramic green sheet. The migration amount of polyorganosiloxane on the surface is reduced. In particular, when a ceramic green sheet is formed using the

release films

1A and 1B, the silicon atomic ratio obtained by measuring the surface of the ceramic green sheet that is in contact with the release surface is less than 1.0 atomic%. In particular, it is preferably less than 0.5 atomic%, more preferably 0.3 atomic% or less. The silicon atom ratio is based on the amount of silicon atoms (Si), carbon atoms (C), and oxygen atoms (O) (XPS count number) measured by, for example, X-ray photoelectron spectroscopy (XPS). It is calculated by the following formula.
Silicon atomic ratio (atomic%) = [(Si element amount) / {(C element amount) + (O element amount) + (Si element amount)}] × 100

In addition, as the ceramic green sheet for measurement, a ceramic green sheet in which silicon is not detected by XPS (that is, does not contain a silicon compound) is appropriately selected, and the silicon atomic ratio is determined based on the migration amount of the polyorganosiloxane in the release agent layer 12. It can be used as an evaluation standard.

5. Manufacturing method of release film for ceramic green sheet manufacturing process When manufacturing release film 1A, one side of substrate 11 is coated with the above-described release agent composition and, optionally, a coating solution containing an organic solvent. Then, the release agent composition is cured by drying and heating, and the release agent layer 12 is formed. Thereby, release film 1A is obtained. As the coating method, for example, gravure coating method, bar coating method, spray coating method, spin coating method, knife coating method, roll coating method, die coating method and the like can be used.

Moreover, when manufacturing peeling film 1B, after applying the coating liquid containing the melamine resin used as the raw material of a melamine resin to one surface of the base material 11, it is resin by drying and heating, for example. Layer 13 is formed. Furthermore, after applying the above-mentioned release agent composition and a coating solution containing an organic solvent as required to the surface of the resin layer 13 opposite to the substrate 11, the release agent composition is dried and heated. Is cured to form the release agent layer 12. Thereby, release film 1B is obtained. As these coating methods, the same coating methods as those described above can be used.

The organic solvent is not particularly limited, and various types can be used. For example, hydrocarbon compounds such as toluene, hexane, heptane, isopropyl alcohol, isobutyl alcohol, acetone, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and mixtures thereof are used. In particular, it is preferable to use a mixed liquid of methyl ethyl ketone and isopropyl alcohol.

The release agent composition coated as described above is preferably thermoset. In this case, the heating temperature is preferably 90 to 140 ° C., more preferably 110 to 130 ° C. The heating time is preferably about 10 to 120 seconds, particularly preferably about 50 to 70 seconds.

6. Method for Using Release Film for Ceramic Green Sheet Manufacturing

Process Release films

1A and 1B can be used for manufacturing ceramic green sheets. Specifically, after applying a ceramic slurry containing a ceramic material such as barium titanate or titanium oxide to the release surface of the release agent layer 12, a ceramic green sheet is obtained by drying the ceramic slurry. Can do. The coating can be performed using, for example, a slot die coating method or a doctor blade method.

Examples of the binder component contained in the ceramic slurry include butyral resins and acrylic resins. Examples of the solvent contained in the ceramic slurry include organic solvents and aqueous solvents.

In the release films 1 A and 1 B, the release agent layer 12 is formed of the release agent composition containing the melamine resin and polyorganosiloxane described above, whereby excellent release properties are exhibited. Furthermore, since a structure in which the polyorganosiloxane is fixed to the melamine resin is formed in the release agent layer 12, the migration of the polyorganosiloxane from the release agent layer 12 to the ceramic green sheet is suppressed. Thereby, when the ceramic green sheets shape | molded using

peeling film

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, the surface on the opposite side of the release agent layer 12 in the base material 11, between the base material 11 and the release agent layer 12 in the release film 1A, or between the base material 11 and the resin layer 13 in the release film 1B, or a resin Another layer such as an antistatic layer may be provided between the layer 13 and the release agent layer 12.

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]
100 parts by mass of imino-type methylated melamine resin (manufactured by Nippon Carbide Co., Ltd., trade name: MX-730, weight average molecular weight 1508) (amount converted as solid content, hereinafter the same) and polyether-modified hydroxyl group-containing polydimethylsiloxane (b1 ) (Manufactured by Big Chemie Japan, trade name: BYK-377, number average molecular weight (Mn) 5078, weight average molecular weight (Mw) 5993, molecular weight distribution (Mw / Mn) 1.18) 0.5 parts by mass, acid 4.0 parts by mass of p-toluenesulfonic acid (trade name: dryer 900, manufactured by Hitachi Chemical Co., Ltd.) as a catalyst was mixed in a mixed solvent of methyl ethyl ketone, isopropyl alcohol and isobutyl alcohol, and the solid content was 20% by mass. A coating solution for the release agent composition was obtained.

The obtained coating solution was uniformly coated on a surface of a biaxially stretched polyethylene terephthalate film (thickness: 25 μm) as a base material having a maximum protrusion height Rp of 452 nm by a Mayer bar # 6. Subsequently, it heat-dried at 120 degreeC for 1 minute (s), the release agent composition was hardened, and the peeling film by which the 1.2-micrometer-thick release agent layer was laminated | stacked on the base material was obtained.

In addition, the thickness of the base material and the release agent layer was measured using a reflective film thickness meter (manufactured by Filmetrics, product name: F20).

[Examples 2 to 4]
A release film was obtained in the same manner as in Example 1 except that the mass parts of the polyether-modified hydroxyl group-containing polydimethylsiloxane (b1) was changed as shown in Table 1.

Example 5
0.5 parts by mass of polyether-modified hydroxyl group-containing polydimethylsiloxane (b1), polyester-modified hydroxyl group-containing polydimethylsiloxane (b2) (manufactured by BYK Japan, trade name: BYK-370, number average molecular weight (Mn) 2689, A release film was obtained in the same manner as in Example 1, except that the weight average molecular weight (Mw) 4283, the molecular weight distribution (Mw / Mn) 1.59) was changed to 1.0 part by mass.

Example 6
A release film was obtained in the same manner as in Example 5 except that the mass parts of the polyester-modified hydroxyl group-containing polydimethylsiloxane (b2) was changed as shown in Table 1.

[Comparative Example 1]
0.5 parts by mass of a polyether-modified hydroxyl group-containing polydimethylsiloxane (b1) and 1.0 part by mass of a polyether-modified polydimethylsiloxane (b3) (manufactured by BYK Japan Japan, trade name: BYK-345, number average) A release film was obtained in the same manner as in Example 1 except that the molecular weight (Mn) was 1194, the weight average molecular weight (Mw) 1563, and the molecular weight distribution (Mw / Mn) 1.31).

[Comparative Example 2]
A release film was obtained in the same manner as in Comparative Example 1 except that the mass parts of the polyether-modified polydimethylsiloxane (b3) was changed as shown in Table 1.

[Test Example 1] (Measurement of total acid value)
The melamine resin used in Examples and Comparative Examples was diluted with isopropyl alcohol so that the solid content concentration was 50% by mass. 10 g of this diluted solution was collected in a 200 mL beaker. On the other hand, 125 mL of a solution in which toluene, pure water and 2-propanol were mixed at a mass ratio of 500: 5: 495 was added to obtain a measurement sample. In addition, when each product of the melamine resin used in Examples and Comparative Examples uses a product other than isopropyl alcohol as a solvent, after drying and removing the solvent, diluting with isopropyl alcohol, the solid content concentration Was 50% by mass.

The measurement sample is titrated with a potassium hydroxide standard 2-propanol solution using a potentiometric automatic titrator (product name: AT-610, EBU-610-20B, manufactured by Kyoto Electronics Industry Co., Ltd.) for neutralization. The amount of potassium hydroxide standard 2-propanol solution required was measured. The measurement was performed 3 times, and the average value was calculated. From this average value, the amount (mg) of potassium hydroxide required to neutralize 1 g of the melamine resin was calculated and used as the total acid value (mgKOH / g). The results are shown in Table 1.

[Test Example 2] (Measurement of peel force)
100 parts by mass of barium titanate (BaTiO ₃ ; manufactured by Sakai Chemical Industry Co., Ltd., trade name: BT-03), 10 parts by mass of polyvinyl butyral (manufactured by Sekisui Chemical Co., Ltd., trade name: ESREC B · KBM-2), and phthalic acid 69 parts by mass of toluene and 46 parts by mass of ethanol were added to 5 parts by mass of dioctyl (manufactured by Kanto Chemical Co., Inc., trade name: dioctyl deer phthalate grade 1), and mixed and dispersed in a ball mill to prepare a ceramic slurry.

In the release film that was manufactured in Examples and Comparative Examples and stored at room temperature for 48 hours, the ceramic slurry was uniformly applied to the release surface of the release agent layer using an applicator. Then, it was made to dry at 80 degreeC with a dryer for 1 minute. As a result, a ceramic green sheet having a thickness of 3 μm was obtained on the release film. In this way, a release film with a ceramic green sheet was produced.

This release film with a ceramic green sheet was allowed to stand for 24 hours in an atmosphere at room temperature of 23 degrees and humidity of 50%. Next, an acrylic pressure-sensitive adhesive tape (manufactured by Nitto Denko Corporation, trade name: 31B tape) was applied to the surface of the ceramic green sheet opposite to the release film, and cut into a width of 20 mm in that state. This was used as a measurement sample.

The pressure-sensitive adhesive tape side of the measurement sample is fixed to a flat plate and peeled off from the ceramic green sheet using a tensile tester (manufactured by Shimadzu Corporation, product name: AG-IS500N) at a peeling angle of 180 ° and a peeling speed of 100 mm / min. The film was peeled and the force required to peel (peeling force; mN / 20 mm) was measured. The results are shown in Table 1.

[Test Example 3] (Evaluation of polyorganosiloxane migration)
In the release film that was manufactured in Examples and Comparative Examples and stored at room temperature for 48 hours, the ceramic slurry was uniformly applied to the release surface of the release agent layer using a 35 μm applicator. Then, it was made to dry at 60 degreeC with a dryer for 1 minute. As a result, a ceramic green sheet having a thickness of 4 μm was obtained on the release film. In this way, a release film with a ceramic green sheet was produced.

The ceramic green sheet is peeled from the release film, and silicon atoms (Si), carbon atoms (measured by X-ray photoelectron spectroscopy (XPS) are measured on the surface of the ceramic green sheet that is in contact with the surface of the release agent layer. Based on the amount of C) and oxygen atoms (O) (XPS count number), the silicon atom ratio (atomic%) was calculated by the following formula.
Silicon atomic ratio (atomic%) = [(Si element amount) / {(C element amount) + (O element amount) + (Si element amount)}] × 100

The polyorganosiloxane migration was evaluated according to the following criteria. Table 1 shows the silicon atomic ratio and the evaluation results.
A: Silicon atomic ratio is less than 0.3 atomic% B: Silicon atomic ratio is 0.3 atomic% or more and less than 0.75 atomic% C: Silicon atomic ratio is 0.75 atomic% or more

Details of the abbreviations and the like described in Table 1 are as follows.
[Polyorganosiloxane]
b1: Polydimethylsiloxane having a polyether-modified hydroxyl group (manufactured by BYK Japan, trade name: BYK-377, number average molecular weight (Mn) 5078, weight average molecular weight (Mw) 5993, molecular weight distribution (Mw / Mn) 1.18 )
b2: Polyester-modified hydroxyl group-containing polydimethylsiloxane (manufactured by BYK Japan, trade name: BYK-370, number average molecular weight (Mn) 2689, weight average molecular weight (Mw) 4283, molecular weight distribution (Mw / Mn) 1.59)
b3: Polyether-modified polydimethylsiloxane (manufactured by Big Chemie Japan, trade name: BYK-345, number average molecular weight (Mn) 1194, weight average molecular weight (Mw) 1563, molecular weight distribution (Mw / Mn) 1.31)

As is clear from Table 1, the release films obtained in the examples could be peeled with an appropriate peeling force when peeled from the ceramic green sheet. Furthermore, it was found that the ceramic green sheet formed using the release film obtained in the example has a small silicon atom ratio, and the migration of polyorganosiloxane is effectively suppressed. In particular, it can be seen that even when the amount of polyorganosiloxane in the release agent composition increases, the migration of polyorganosiloxane is suppressed. In addition, in the release sheet obtained in the Example, it was also confirmed that the maximum protrusion height Rp of the release surface was relatively low and the smoothness was excellent.

On the other hand, it was found that the release film obtained in the comparative example required a strong peeling force when peeling from the ceramic green sheet. Moreover, in the ceramic green sheet shape | molded using the peeling film obtained by the comparative example, it turned out that the silicon atom ratio is large and the transfer of polyorganosiloxane is not fully suppressed.

The release film for a ceramic green sheet production process of the present invention is suitable for forming a ceramic green sheet.

1A, 1B ... Release film for ceramic green sheet manufacturing process 11 ... Base material 12 ... Release agent layer 13 ... Resin layer

Claims

A release film for a ceramic green sheet manufacturing process comprising a substrate and a release agent layer provided on one side of the substrate,
The release agent layer is
A polyorganosiloxane having at least one hydroxyl group in one molecule;
A release film for a ceramic green sheet manufacturing process, comprising a release agent composition containing a melamine resin having a total acid value of 0.030 to 0.154 mg KOH / g.
2. The ceramic green sheet manufacturing process according to claim 1, wherein the polyorganosiloxane has at least one organic group selected from a polyester group and a polyether group in one molecule. Release film.
3. The release film for producing a ceramic green sheet according to claim 1, wherein at least one of the hydroxyl groups is present at an end of the polyorganosiloxane.
The release film for a ceramic green sheet production process according to any one of claims 1 to 3, wherein the polyorganosiloxane has a weight average molecular weight of 1,000 to 300,000.
The melamine resin has the following general formula (a)

(In the formula, X represents —H, —CH 2 —OH, or —CH 2 —O—R, and may be the same or different. R represents a carbon number of 1-8. Each represents the same or different alkyl group, and at least one X is —CH 2 —OH.)
The release film for a ceramic green sheet production process according to any one of claims 1 to 4, comprising a compound represented by the formula (1) or a polynuclear product obtained by condensing two or more of the compounds.
The release film for a ceramic green sheet production process according to any one of claims 1 to 5, wherein the release agent composition further contains an acid catalyst.
The release film for a ceramic green sheet manufacturing process according to any one of claims 1 to 6, wherein the release agent layer has a thickness of 0.1 to 3 µm.
The release film for a ceramic green sheet production process according to any one of claims 1 to 7, further comprising a resin layer positioned between the substrate and the release agent layer.