WO2003099556A1

WO2003099556A1 - Releasing film

Info

Publication number: WO2003099556A1
Application number: PCT/JP2003/006473
Authority: WO
Inventors: Masanori Nishiyama
Original assignee: Teijin Dupont Films Japan Limited
Priority date: 2002-05-27
Filing date: 2003-05-23
Publication date: 2003-12-04
Also published as: AU2003242434A1; CN100379553C; TWI319750B; KR20040111342A; JP3950462B2; JPWO2003099556A1; TW200400879A; CN1655927A; KR100919440B1

Abstract

A releasing film which comprises a polyester base film having a surface exhibiting an appropriate irregularity and a silicone releasing layer, or comprises a polyester base film having a flat and smooth surface and a silicone releasing layer exhibiting an appropriate irregularity. The releasing film has excellent surface characteristics so that it is free from problems wherein concaves and convexes of the surface thereof are transferred to the surface of a formed sheet, is excellent in processability, and also is excellent in releasing characteristics.

Description

Description Release film Technical field

The present invention relates to a release film. More specifically, the present invention relates to a release film having excellent surface characteristics in which surface irregularities are not transferred to a molded sheet, and having excellent workability and release properties. Conventional field

Release films are used, for example, for molding resin sheets, for releasing adhesives, for medical use, and for manufacturing electrical and electronic components. In a molded article such as a resin sheet molded from a release film, flattening the surface of the molded article is an important issue. It is no exaggeration to say that the quality of a molded product formed from a film depends on the accuracy and quality of its surface, that is, the accuracy and quality of the surface of the release film.

The release film itself is formed by providing a polyester film with a resin layer having a release property, for example, a silicone resin layer. Usually, particles are blended in a polyester film to improve processability, for example, slipperiness and winding characteristics, but in general, handling is improved by adding particles to the film, but the surface of the film is improved. Coarse. If the mixing of the particles is stopped to avoid this and create a flat surface, the resulting film will have extremely poor slipperiness and air bleeding properties, and will have seams during processing and will be rolled up. Will not be. In addition, when the film is accompanied by a silicone coating layer, the silicone layer covers the protrusions on the surface of the polyester film, thereby further reducing the processability.

Conventionally, in the case of molded articles or molded sheets molded from a release film, there is no strict requirement for the surface characteristics, and even with a certain degree of rough surface, there has been no quality problem. The requirements for the surface properties of molded sheets using mold films have become very strict. For example, a sheet of vinyl chloride resin or urethane resin These resin solutions are cast on a release film to form a sheet. These sheets may require particularly high gloss on the molding surface. In addition, in the case of a release film for adhesive tape, the irregularities on the release film surface are transferred to the surface of the adhesive layer of the adhesive tape. Air enters into the recesses where the shape has been transferred to the mold, and a clean appearance cannot be obtained. Therefore, strict flatness of the surface is required.

In addition, release films used as process materials for electronic components have particularly high requirements for surface characteristics. For example, when making a thin sheet of a ceramic capacitor, apply a ceramics slurry in which ceramic powder and a binder agent are dispersed in a liquid medium on a release film, and use a very thin sheet of 3 m or less. Create The thinner the sheet, the higher the demands on the surface properties of the release film because the surface irregularities of the release film directly increase the defective rate of the molded sheet. Also, when used as a process material for display applications, the release film surface is required to have a smooth surface by making the molded sheet thinner. Disclosure of the invention

An object of the present invention is to solve the drawbacks of the prior art, and to have excellent surface characteristics in which large irregularities on the surface of the release film are not transferred to the molding sheet, as well as excellent workability and good release characteristics. An object of the present invention is to provide a release film.

Other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the present invention are:

(a) a polyester film having a surface having a centerline average roughness Ra of 15 nm or less and a ten-point average roughness Rz of 30 to 500 nm; and

(b) a silicone release layer formed on the surface of the polyester film and having a thickness of not more than 0.8 times 1 ^ 2 of the surface

This is achieved by a release film characterized by comprising (hereinafter, referred to as a first release film of the present invention).

According to the present invention, the above objects and advantages of the present invention are: (a ') a polyester film having a surface having a centerline average roughness Ra of 5 nm or less and a ten-point average roughness Rz of 30 nm or less; and

Cb ′) formed on the surface of the polyester film and having the following formula (1) 0.3 d ≦ t ≦ 2.5 d (1)

Where d is the average particle size of the inert particles (nm) and t is the thickness of the silicon release layer (nm),

This is achieved by a release film (hereinafter, referred to as a second release film of the present invention) comprising a silicone release layer having a thickness of 300 nm or less and containing inert particles satisfying the following. Preferred embodiments of the invention

Hereinafter, the present invention will be described in detail. First, the first release film will be described. The first release film comprises a polyester film (a) and a silicone release layer (b) formed on its surface.

As the polyester for the polyester film (a), a polyester containing an aromatic dicarboxylic acid as a main acid component and an aliphatic glycol as a main glycol component is preferably used. The dark polyester is substantially linear and has film formability, especially film formability by melt molding.

Aromatic dicarboxylic acids include, for example, terephthalic acid, naphthalenedicarboxylic acid, isophthalic acid, diphenoxyethane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl terdicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl ketone dicarboxylic acid and Anthracene dicarboxylic acid can be mentioned. Examples of the aliphatic glycol include polymethylene glycol having 2 to 10 carbon atoms such as ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol and decamethylene glycol, and cyclohexane. Alicyclic diols such as xanthyl alcohol can be mentioned.

In the present invention, as the polyester, alkylene terephthalate or a Those containing ruchilennaphthalate as a main component are preferably used.

As such a polyester, for example, polyethylene terephthalate or polyethylene-1,2,6-naphthalate is preferable. It is to be understood that the polyethylene terephthalate includes copolymers wherein, for example, at least 80 mole% of the total dicarboxylic acid component is terephthalic acid and at least 80 mole% of the total glycol component is ethylene glycol. It is. Similarly, the polyethylene mono-2,6-naphthalate contains, for example, at least 80 mol% of the total dicarboxylic acid component is 2,6-naphthalenedicarboxylic acid and at least 80 mol% of the total dalicol component is e.g. It should be understood that copolymers that are ethylene glycol are included.

In such copolymers, up to 20 mole percent can be terephthalic acid or another dicarboxylic acid component different from 2,6-naphthalenedicarboxylic acid. Such other dicarboxylic acid components include, for example, aromatic dicarboxylic acids as described above; for example, alicyclic dicarboxylic acids such as adipic acid and sebacic acid, and alicyclic dicarboxylic acids such as cyclohexane-1,4-dicarponic acid. Can be

Further, 20 mol% or less of the total glycol component can be another glycol component different from ethylene glycol. Such other dalicol components are, for example, dalicol as described above; for example, an aromatic diol such as hydroquinone, resorcin, 2,2-bis (4-hydroxyphenyl) propane; and a fat having an aromatic ring such as 1,4-dihydroxydimethylbenzene. Group diols or polyalkylene glycols (polyoxyalkylene glycols) such as polyethylene diol, polypropylene glycol and polytetramethylene glycol.

In the polyester of the present invention, a component derived from an oxycarboxylic acid such as an aromatic oxyacid such as hydroxybenzoic acid or an aliphatic oxyacid such as ω-hydroxycabronic acid may be used as a dicarboxylic acid component or an oxycarboxylic acid component. And those which are copolymerized or bonded in an amount of 20 mol% or less based on the total amount of

In addition, polyesters may contain tri- or higher functional polycarboxylic acids or polyhydroxy compounds in amounts that are substantially linear, for example, up to 2 mole percent, based on the total acid component. Substances, for example, those obtained by copolymerizing trimellitic acid and pentaerythritol.

The polyester is known per se and can be produced by a method known per se. As the above-mentioned polyester, those having an intrinsic viscosity of 0.4 to 0.9 measured at 35 ° C. as a solution in phenol with O-cloth are preferable.

In the present invention, the polyester film (a) preferably contains inert particles. The average particle size of the inert particles is preferably less than 1 m, more preferably 0.01 m or more and less than 1 m, more preferably 0.03 111 or more and less than 1111. The inert particles may be either organic particles or inorganic particles, or may be mixed particles of organic particles and inorganic particles. Further, the ratio of the major axis to the minor axis (major axis / minor axis) of the inert particles is preferably from 1.0 to 1.2. By blending these inert particles, appropriate irregularities can be formed on the film surface. Specific examples of such inert particles include inorganic particles such as calcium carbonate, kaolin, gen oxide, barium sulfate, titanium oxide, oxidized alumina; crosslinked polystyrene, crosslinked silicone resin particles, crosslinked acrylic resin particles, crosslinked. Examples include organic resin particles such as polystyrene particles and particles in which an inorganic material and an organic material take the form of a shell core structure.

These inert particles can be used alone or in combination of two or more, for example, three or four.

The amount of the inert particles to be added is 0.01 to 0.3% by weight based on the polyester.

The polyester film (a) preferably has a thickness of 0.1 to 30 times the average particle size of the inert particles contained therein.

If the thickness of the polyester layer is less than 0.1 times the average particle size, the contained inert particles are likely to fall off, which is not preferable. On the other hand, if the average particle diameter exceeds 30 times, the inert particles contained in the polyester layer are liable to overlap, and irregularities are easily formed on the surface of the film.

The polyester film (a) has a center line average roughness Ra of 15 nm or less. The surface has a ten-point average roughness Rz of 30 to 500 nm. If Ra exceeds 15 nm, shape transfer will occur on the surface of the molded body. Ra is preferably from 1 to 13 nm.

Also, if Rz is less than 3 O nm, winding in a roll form and slipping with a pass roll become poor, resulting in poor handling characteristics of the processing step. Shape transfer occurs.

Rz is preferably between 50 and 300 nm.

The thickness of the polyester film (a) is preferably from 10 to 100 m, more preferably from 25 to 50 m.

The first release film of the present invention is obtained by forming a silicone release layer (b) described below on the surface having the above Ra and Rz of the polyester film (a). b) Another polyester layer may be provided on the surface opposite to the surface on which is formed.

Such another polyester layer can be formed as a laminated film together with the polyester film (a). The laminated film can be composed of at least two layers, and is preferably manufactured by co-extrusion. In this case, the polyester constituting the layer may be the same or different, but the same is preferred. For example, when the other polyester layers are referred to as layer B and layer C, for example, a polyester film (a) layer / layer B, a polyester film (a) layer ZB layer Z a polyester film (a) layer or a polyester film (a ) A laminated structure such as layer / layer B / layer C can be adopted.

In the case of a laminated film, it is preferable that the outermost layer on the opposite side of the polyester film (a) layer forming the release layer (b), for example, the B layer and the C layer in the above example, contain inert particles. In this case, the inert particles preferably have an average particle size of from 0.1 to 1.0 m.

The laminated film preferably has a total thickness of 10 to 100 m, more preferably 25 to 50 m, as a total thickness including the polyester film (a) layer. The polyester film (a) and the laminated polyester film itself can be obtained by a conventionally known method or a method accumulated in the art. In order to obtain a biaxially oriented film, for example, the polyester is melted at a temperature of melting point (Tm: ° C) or (Tm + 70) ° C and coextruded to obtain an intrinsic viscosity of 0.4 to 0.8 dLZ g. To obtain an unstretched film of Next, the unstretched film is (Tg-10) to (Tg + 70) in the uniaxial direction (longitudinal direction or horizontal direction). Stretching at a temperature of C (Tg: glass transition temperature of polyester) of 2.5 times or more, preferably 3 times or more, and then Tg to (Tg + 70) ° in a direction perpendicular to the above stretching direction The film is stretched at a temperature of C at a ratio of at least 2.5 times, preferably at least 3 times. Further, if necessary, the film may be stretched again in the machine direction and / or the cross direction. Thus, the total stretching ratio is preferably 9 times or more, more preferably 12 to 35 times, particularly preferably 15 to 25 times as the area stretching ratio. Furthermore, the biaxially oriented film can be heat-set at a temperature of (Tg + 70) ° C to (Tm-10) ° C (where Tm is the melting point of the polyester), for example, 180 to 250 °. C is preferred. The heat setting time is preferably 1 to 60 seconds. In the above, when the film is a laminated film in which each layer is formed from a different polyester, the melting point and the glass transition temperature are the melting point and the glass transition temperature of the polyester having a higher melting point and a higher glass transition temperature. Should be understood to mean

As described above, the first release film of the present invention is obtained by forming a silicone release layer (b) on the surface of a polyester film (a). The silicone release layer (b) may be formed on one side or both sides of the polyester film (a). In the present invention, the release layer is preferably made of polydimethylsiloxane or a mixture containing the same as a main component and the following component (1) or (2), or modified by the following (3) or (4). It is composed of polydimethylsiloxane or the addition type silicone resin of the following (5).

(1) A silicone resin having the following D unit, T unit and Z or Q unit structure in a polydimethylsiloxane polymer. This silicone resin is blended with polydimethylsiloxane to increase the surface tension by adjusting the concentration of methyl groups in the release layer. Can be made. The silicone resin is preferably mixed at a solid content of 10 to 60% by weight. If the resin content is less than 10% by weight, wettability may be poor when forming a molded sheet, and the resin sheet may repel. On the other hand, if it is more than 60% by weight, the peeling force is too high, and the molded body cannot be peeled.

R

D-0- Si-O-bifunctional

R R

T -O-Si-O- trifunctional

0-O-

Q-. -Si-O- tetrafunctional

O—

Here, R represents an alkyl group, preferably a methyl group, or an aromatic hydrocarbon group, preferably a phenyl group.

(2) Silica filler. By blending a silica filler in the polydimethylsiloxane polymer, the concentration of one Si SH group in the release layer can be adjusted to be higher. The silica filter preferably has an average particle size of 1 m or less. If the average particle size exceeds 1 m, the haze of the film will increase, which may hinder the use of the film in applications requiring transparency, or may cause separation when the film is run in the processing process. It is not preferable because the mold layer may be scraped. The mixing ratio of the silica filler is preferably from 0.01 to 1% by weight in terms of solid content. If the compounding ratio is less than 0.01% by weight, the slipperiness of the roll with the silicone surface deteriorates, and if it exceeds 1% by weight, it is not preferable because it may be shaved off the silica filler release layer and fall off.

(3) Modified polydimethylsiloxane in which some of the methyl groups in the polydimethylsiloxane polymer have been replaced by phenyl groups. Due to the steric hindrance of the phenyl group, for example poly Rotational movement around the S i-one S i-one bond in the mer is suppressed, and as a result, the surface tension can be increased because the concentration of methyl groups on the release layer surface decreases. The substitution ratio of the phenyl group is preferably 10 to 60 mol%. If the substitution ratio is less than 10 mol%, the molded layer tends to repel and may not be applied. If the substitution ratio is more than 60 mol%, the releasability between the release layer and various adhesives or various sheets may be poor. It is not preferable because there is.

(4) Reaction of polydimethylsiloxane polymer having a relatively high concentration of reactive groups such as silanol group and methoxy group with an organic shelf having a hydroxyl group in the molecule (eg, alkyd resin, polyester resin, acrylic resin) A modified polydimethylsiloxane obtained by the reaction. The proportion of the dimethylsiloxane component in the modified polydimethylsiloxane is preferably 10 to 30% by weight. If this ratio is less than 10% by weight, the releasability may be poor, and if it exceeds 30% by weight, silicone transfer occurs, which is not preferable.

(5) An addition reaction type silicone resin, for example, an addition reaction type silicone resin composed of polydimethylsiloxane having a vinyl group introduced therein and hydrogen silane. The ratio of polydimethylsiloxane having a vinyl group to hydrogen silane is such that the vinyl group in polydimethylsiloxane is 1.0 to 2.0 per 1.0 mole of one SiH group in hydrogen silane. A molar ratio is preferred.

Adjusting the methyl group concentration in the release layer can increase the surface tension. Therefore, the silicone resin of the above (1) may be blended with the silicone resin. The mixing ratio of the silicone resin is preferably not more than 60% by weight, more preferably 0.1 to 30% by weight, in terms of solid content, from the viewpoint of obtaining an appropriate peeling force.

The polydimethylsiloxane having a vinyl group may contain one SiAr ₂ — and one SiAr (R) group in addition to the —Si (CH ₃ ) ₂ — group. Here, the Ar group is an aromatic hydrocarbon group, and is preferably a phenyl group. The R group is an alkyl group, preferably a methyl group. When the polydimethylsiloxane having a pinyl group contains one —S i Ph (CH ₃ ) group or _S i (Ph) ₂ — group, From the viewpoint of suppressing the disorder of the molecular structure and securing an appropriate peeling force and sufficient hardness, these groups should be 0.5 mol or less with respect to 1 mol of one S i (CH ₃ ) ₂ — group. Is preferred. Here, Ph is a phenyl group.

The addition reaction type silicone resin may have a three-dimensional crosslinked structure, and the three-dimensional crosslinked structure can be obtained by reacting with a platinum catalyst. Further, as the type of curing silicone, besides the above-mentioned thermosetting type, a curing type using ultraviolet rays or a silicone type using an electron beam may be used. It is important that the thickness of the silicone release layer is not more than 0.8 times the ten-point average roughness Rz of the surface of the polyester film (a) on which the silicone release layer is formed. If it exceeds 0.8 times 1.2, the silicone resin will enter the recesses of the slightly uneven portion due to the particles in the film, and as a result, the center line average roughness Ra and the ten-point average roughness R of the surface of the release layer will be obtained. z becomes low, resulting in poor handling properties in the process and problems due to blocking of the release layer (backside transfer).

The silicone release layer preferably contains inert particles having an average particle size of 5 to 8 O nm. By containing the inert particles, it is possible to obtain good handling characteristics in the process and an effect of improving blocking.

The first release film of the present invention preferably has a center line average roughness Ra of the exposed surface of the silicone release layer (b) of 15 nm or less and a ten-point average roughness Rz of 10 or less. 0 to 500 nm.

In the first release film of the present invention, the sum of the center line average roughnesses Ra of both exposed surfaces is preferably 12 nm or more. If it is less than 12 nm, winding in a roll form and slippage with a pass roll are poor, resulting in poor handling of the process and blocking of the release layer (backside transfer).

Various known additives can be added to the release layer as long as the object of the present invention is not hindered. As the additive, for example, an ultraviolet absorber, a pigment, an antifoaming agent, or an antistatic agent may be added as needed.

In the present invention, an adhesive layer is provided between the polyester film (a) and the release layer (b) in order to enhance the adhesion between the polyester film (a) and the release layer (b). You may. For this adhesive layer, for example, a silane coupling agent can be preferably used. As the silane coupling agent include those represented by the formula Y- S i- X _3. Here, Y represents a functional group represented by, for example, an amino group, an epoxy group, a vinyl group, a methacryl group, a mercapto group, and X represents a hydrolyzable functional group represented by an alkoxy group. The preferred thickness of the above-mentioned adhesive layer is about 0.05 to 1 m, particularly preferably 0.02 to 0.5 m. When the thickness of the adhesive layer is in the above range, the adhesion between the polyester film (a) and the release layer (b) becomes good, and the polyester film provided with the adhesive layer (b) is difficult to block, so that it is difficult to handle. It is hard to cause trouble.

In the present invention, the release layer can be provided, for example, by applying a coating liquid containing the components of the release layer to a film and drying by heating. As a method of applying the coating liquid, any known coating method can be applied. Applicable coating methods include, for example, a mouth-coating method and a blade-coating method, but are not limited to these methods. The heating and drying for forming the coating layer is preferably performed at 70 to 170 ° C. for 20 to 60 seconds.

Next, the second release film of the present invention will be described.

The second release film comprises a polyester film (a ') and a release film (b') formed on the surface thereof.

As the polyester of the polyester film (a '), the same polyesters as those described for the first release film can be used.

The polyester film (a ′) may or may not contain inert particles. When it is contained, the same inert particles as those described for the polyester film (a) of the first release film can be used as the inert particles. These inert particles can be used alone or in combination of two or more. Such inert particles can be blended in an amount of 0.2% by weight or less based on the polyester. The polyester film (a ′) has a surface having a center line average roughness (R a) of 5 nm or less and a ten-point average surface roughness (R z) of 3 O nm or less. If the center line average roughness (Ra) exceeds 5 nm, the surface smoothness of the thin-layer molded sheet is impaired, and If the average surface roughness (Rz) exceeds 3 Onm, unevenness in the thickness of the formed sheet will occur, and poor electrical properties will occur in electronic material applications. Ra is preferably 0-5 nm, and Rz is preferably 3-3 Onm.

The thickness of the polyester film (a ') is preferably from 10 to 100 m, and more preferably from 15 to 50 m.

The second release film of the present invention is obtained by forming a silicone release layer (b ′) described later on the surface having the above Ra and Rz of the polyester film (a ′). Another polyester layer may be provided on the surface opposite to the surface on which the mold layer (b ') is formed. Such another polyester layer can be formed as a laminated film together with the polyester film (a '). For such a laminated film, it is understood that the description given for the first release film is applied as it is by replacing the polyester film (a) with the polyester film (a ').

Further, the polyester film (a ′) and the laminated film can be manufactured in the same manner as the manufacturing method described for the first release film.

As described above, the second release film of the present invention is obtained by forming a silicone release layer (b ′) on the surface of a polyester film (a ′).

The silicone release layer (Β ′) may be formed on one side or both sides of the polyester film (a ′).

The release layer is preferably made of polydimethylsiloxane or a main component thereof, and the release layer of the first release film is blended with the component (1) or (2) described above. It comprises the modified polydimethylsiloxane of (3) or (4) or the addition-type silicone resin of (5). Of these, addition silicone resins are preferred.

In the second release film, the silicone release layer preferably has a hardness of 10 Omg fZ / xm ² or more in microhardness measurement. By setting the hardness to 10 Omgί / urn ² or more, blocking can be prevented, the contact area when the film is wound into a roll can be sufficiently reduced, and peeling charge can be suppressed. Monkey

The thickness of the silicone release layer is 30 O nm or less, preferably 30 to 300 nm, and more preferably 50 to 200 nm. Above 300 nm, blocking tends to occur. If the thickness is less than 3 O nm, the peeling properties are not stable, and the peeling may be undesirably heavy.

In the present invention, the silicone release layer contains inert particles. The inert particles impart many fine irregularities to the flat release layer surface. Since the unevenness is very fine, even if the shape of the unevenness is transferred from the release film to the molded sheet, it is not at a level that causes a problem. By adding the inert particles, transfer (blocking) to the back surface of the release layer is improved, and process suitability is improved.

For this purpose, the average particle size of the inert particles is preferably from 1 to 10 O nm, more preferably from 3 to 80 nm, particularly preferably from 3 to 50 nm. Further, the ratio of the major axis to the minor axis (major axis / minor axis) of the inactive particles is preferably 1.0 to 1.2. Such inert particles may be either organic particles or inorganic particles, or may be mixed particles of organic particles and inorganic particles. Specific examples of such inert particles include inorganic particles such as calcium carbonate, kaolin, silicon oxide, barium sulfate, titanium oxide, oxidized alumina, magnesium oxide, and oxidized zirconium; crosslinked polystyrene resin particles, and crosslinked silica. Examples thereof include organic resin particles such as cone resin particles, crosslinked acrylic resin particles, and crosslinked polystyrene resin particles, and particles in which an inorganic material and an organic material have a shell core structure. In particular, in the case of fine particles, inorganic particles are preferred.

The mixing amount of the inert particles in the silicone release layer is preferably 0.1 to 25% by weight, and more preferably 0.3 to 5% by weight. If the addition amount is less than 0.1, slipperiness and blocking of the release layer occur, and the release characteristics of the release layer become unstable, which is not preferable. If it exceeds 25% by weight, the transparency is lowered, and aggregation is likely to occur, and coarse aggregates are generated, which is not preferable.

The silicone release layer has the following formula (1):

0.3 d≤ t≤2.5 d (1)

Where t (nm) is the thickness of the silicone release layer and d (nm) is inactive Average particle size of the conductive particles,

It is necessary to satisfy

If the thickness t (nm) of the silicone release layer is less than 0.3 d, the inert particles will fall off and cause foreign matter, and if it exceeds 2.5 d, fine irregularities on the surface will be formed. This results in poor slipperiness, which results in poor handling, winding, and peeling electrification. In the second release film of the present invention, it is preferable that the projections on the exposed surface of the release layer satisfy the following expressions (2) and (3).

HD5 ≥ 500 pieces Zmm ²

HD 10≤100pcs Zmm ²

Here, HD 5 is the number of protrusions with a height of 5 nm or more, and HD 10 is the number of protrusions with a height of 10 nm or more.

Is preferably satisfied.

If the HD5 is less than 500, slipperiness is poor, and handling, winding properties, and peeling electrification are poor. If HD10 exceeds 100, the shape is transferred to the surface of the molded sheet, which causes unevenness in the thickness of the sheet, which is not preferable.

HD5 and HD10 have the following relationships (2 ') and (3'):

10,000 ≥HD 5≥1, 000 · ·-(2 ')

10≤HD 10≤70 · · · (3,)

Is more preferably satisfied.

The second release film of the present invention preferably has a center line average roughness Ra of 5 nm or less and a ten-point average roughness Rz of 30 nm or less on the exposed surface of the silicone release layer (b '). It is.

Additives may be added to the release layer in the present invention as long as the object of the present invention is not hindered. Examples of the additive include an ultraviolet absorber, a pigment, an antifoaming agent, and an antistatic agent. Further, separately from the release layer, such an additive may be blended into a resin, and the resin may be applied to the surface of the polyester film (a ′).

In the present invention, the polyester film (a ') is subjected to corona treatment or polyester treatment to enhance the adhesion between the polyester film (a') and the release layer. An adhesive layer may be provided between the release film (a ') and the release layer. It is preferable to use a silane coupling agent for the adhesive layer. The same silane coupling agent as that described for the first release film is used. The preferable thickness of the above-mentioned adhesive layer is about 0.005 to 0.1 m, and particularly preferably 0.01 to 0.1 fim. When the thickness of the adhesive layer is in the above range, the adhesion between the polyester film (a ') and the release layer becomes good.

The release layer can be formed in the same manner as described for the first release film. It should be understood that items not described for the second release film are applied as they are for the first release film, or as they are obvious to those skilled in the art. Example

Hereinafter, the present invention will be further described with reference to examples.

In addition, each characteristic value of the film was measured by the following method.

(1) Average particle size of inert particles (d)

Measured using a Shimadzu CP-50 Centrifugal Particle Size Analyzer. The particle size corresponding to 50 mass percent is read from the integrated curve of particles of each particle size and its abundance calculated based on the obtained centrifugal sedimentation curve, and this value is defined as the above average particle size. (See Book "Particle Size Measurement Techniques" Published by Nikkan Kogyo Shimbun, 1995, pp. 242 to 247).

(2) Average particle size of inert particles and ratio of major axis to minor axis in film

Embed the film sample in epoxy resin, cut out a cross section with a thickness of 50 m, and measure the particle shape in the cross section by TEM (transmission electron microscope).

(3) Center line average roughness (Ra (nm)), HD5 and HD10

Contact measuring method

The center line average roughness (Ra) is a value defined by JIS-B0601, and was measured using a stylus type surface roughness meter (SURFCORDER SE-30C) of Kosaka Laboratory Co., Ltd. The measurement conditions are as follows. (a) Stylus tip radius 2 μ, πι

(b) Measurement pressure 3 Omg

(c) Cut-off 0.25 mm

(d) Measurement length 1.0 mm

(2) Center line average roughness Ra (nm)

Non-contact measurement method

The center line average roughness (Ra) is measured by using a non-contact type surface roughness meter of WYK CORPORATION ON 2000-2. The measurement conditions are as follows.

(a) Measurement area: 0.0462

(b) Measurement magnification: 25 times

For HD5 and HD10, from WYKO measurement data, the particle size and the distribution of protrusions were determined, and the number of protrusions at a particle size of 5 nm was set to HD5, and the number of protrusions at a particle size of 10 nm was set to HD10. .

(4) Ten point average roughness (Rz (nm))

Contact measuring method

The ten-point average roughness (Rz) is a value defined in JIS-B0601. In the present invention, it is obtained by using a stylus type surface roughness meter (SURFCORDER SE-30C) of Kosaka Seisakusho Co., Ltd. The difference between the average of the peaks up to the fifth peak and the average of the peaks of the valleys from the deepest to the fifth is shown for the part extracted by the reference length from the section curve of the night.

Non-contact measurement method

The ten-point average surface roughness Rz is measured using a non-contact surface roughness meter of WYKO CORPORATI ON NT-2000. The measurement conditions are as follows.

(a) Measurement area: 0.0462 m

(b) Measurement magnification: 25 times

In any of the measurement methods, the average of the elevations at the top of the fifth peak and the average of the elevations at the bottom of the valley from the deepest to the fifth at the part extracted by the reference length from the cross-sectional curve of the obtained data. Shows the value of the difference.

(5) Silicone film thickness measurement (Ts i (nm)) The cross section of the release film is cut with a microtome, and the thickness of the silicone layer is measured by observing the obtained sample with a TEM.

(6) Handleability

Dynamic friction coefficient S:

Two release films are stacked on a glass plate, the film on the lower side of the laminated film (the film in contact with the glass plate) is pulled on a constant speed roll, and the detector is fixed to one end of the upper film. To detect the tensile force (F) between the films Z. Incidentally, the film make a 200 gZ50 cm ² load (P).

S = F (g) / P (g)

Good handling performance when liS = l or less ◎

/ iS = l or more and 2 or less can be handled 〇

S = 2 or more is not allowed. X After releasing the release film 1000 times in a roll and aging at 60 ° C for 1 month, the sticking phenomenon is visually observed on the release surface and the back surface of the film and evaluated according to the following criteria.

〇: No blocking

X: With pre-licking

Sharpness:

The film surface is worn with black paper, and the occurrence of white powder is visually observed and evaluated according to the following criteria. 〇: No white powder

X: White powder

(7) Hardness measurement

The hardness of the release layer film was measured directly by using ENT-1100a manufactured by Elionix Inc. For the measurement, apply a load of 2 mgf with a triangular pyramid indenter, and calculate the hardness from the amount of deformation of the release layer.

Example 1

Prepare polyethylene terephthalate A and B, use polyethylene terephthalate A for the layer on which the release layer is provided, and use polyethylene terephthalate B for the other layer. Was used to produce a two-layer laminated polyester film.

First, dimethyl terephthalate and ethylene glycol were used, manganese acetate was used as a transesterification catalyst, antimony trioxide was used as a polymerization catalyst, phosphorous acid was used as a stabilizer, and the average particle diameter was 0 as inert particles of a lubricant. 0.3% by weight of l ^ m acid sulfide was mixed and polymerized by a conventional method to obtain polyethylene terephthalate A having an intrinsic viscosity (orthochlorophenol, 35 ° C) of 0.62.

Also, instead of silicon oxide as inert particles of the lubricant, 0.05% by weight of crosslinked silicone particles (major diameter / minor diameter = 1.05) having an average particle diameter of 0.5 m and a mean particle diameter of 0.2 Polyethylene terephthalate B was obtained in the same manner as in the above-mentioned poly (ethylene terephthalate) A, except that 0.4% by weight of m.

These polyethylene terephthalate pellets were dried at 170 for 3 hours, fed to two extruder hoppers, melted at a melting temperature of 280 to 300 ° C, laminated using a multi-manifold extrusion die, and finished with a surface of 0.3. This was extruded on a rotary cooling drum having a surface temperature of 20 ° C. for about s to obtain an unstretched two-layer laminated film having a thickness of 540 / zm. The unstretched laminated film thus obtained is preheated to 75 ° C, and further heated by a single IR heater with a surface temperature of 900 ° C from 15 mm above between low-speed and high-speed rolls. 3. The film was stretched 6 times, quenched, then supplied to stainless steel overnight, and stretched 3.9 times horizontally at 105 ° C. The obtained biaxially oriented film was heat-set at a temperature of 205 ° C for 5 seconds, and the thickness was 38 πι (the thickness of the polyester layer on the side where the release layer was provided was 36 m, and the thickness of the polyester B layer on the opposite side. A 2 m) heat-set biaxially oriented laminated polyester film was obtained.

Further, on this film, a curable silicone (KS-847 (H) manufactured by Shin-Etsu Silicone Co., Ltd.) of the type that adds a platinum catalyst to a mixed solution of polydimethylsiloxane and dimethylhydrogensilane to cause an addition reaction, , Isobutyl ketone and toluene were dissolved in a mixed solvent to prepare a solution with a total solid concentration of 3% by weight, and then applied by a conventional roll coating method to a dry film thickness of 55ηm. A film was obtained. Heat drying for 30 seconds at 160 became. Table 1 shows the properties of the release film.

Example 2

Inert particles mixed with polyethylene terephthalate A in Example 1 were changed to 0.12% by weight of crosslinked silicone particles having an average particle size of 0.3 m, and polyethylene terephthalate B was mixed with inert particles. Changed to something that does not. The polyethylene terephthalate rate was co-extruded with a multi-manifold die so as to have an A / BA configuration, and the extrusion amount was adjusted so that the thickness configuration was mZ34 / im / 2m. The release layer had a thickness of 77 nm. Except for these, a release film was obtained in the same manner as in Example 1.

Example 3

Using only the polyethylene terephthalate A used in Example 2, a film of 38 m was produced, and the release layer had a thickness of 77 nm. Except for these, a release film was obtained in the same manner as in Example 2.

Comparative Example 1

Dimethyl terephthalate and ethylene glycol are polymerized by a conventional method using manganese acetate as a transesterification catalyst, antimony trioxide as a polymerization catalyst, phosphorous acid as a stabilizer, and an intrinsic viscosity (orthochlorophenol, 3 5 ° C) was obtained. 0.05% by weight of silicon oxide having an average particle size of 1.7 m is blended in polyethylene terephthalate as inert fine particles of lubricant to obtain a single layer film, and the thickness of the release layer is set to 98 nm. Except for the above, a release film was obtained in the same manner as in Example 1.

Comparative Example 2

A release film was obtained in the same manner as in Comparative Example 1, except that the inert particles in Comparative Example 1 were replaced with particles having an average particle size of 0.1 m.

Comparative Example 3

A release film was obtained in the same manner except that the silicone release film thickness was applied to the film obtained in Example 1 so as to be 20 O nm. Table 1 Polyestenolefinolem release film

Ra (one side) Rz (one side) Ra (other side) One side (layer side) Other side Sum of roughness Tsi

Processing suitability, ηττυ Ra (run) Rz (nm) (ran), nm nm Example 1 12 132 12 10 76 12 22 77 〇 Example 2 7 74 9 5 35 9 14 55 〇 Example 3 13 142 14 11 83 13 24 77 〇 Comparative example 1 29 870 29 27 790 29 56 98 〇 Comparative example 2 5 58 5 3 12 5 8 55 X Comparative example 3 7 74 9 2 10 9 11 200 X

Example 4

First, dimethyl terephthalate and ethylene glycol are polymerized by a conventional method using manganese acetate as a transesterification catalyst, antimony trioxide as a polymerization catalyst, and phosphorous acid as a stabilizer, and an intrinsic viscosity. (Orthochlorophenol, 35 ° C) 0.62 polyethylene terephthalate was obtained.

The pellets of polyethylene terephthalate were supplied to an extruder hopper after drying at 170 ° C for 3 hours, melted at a melting temperature of 280 to 300 ° C, and then extruded using an extrusion die. It was extruded on a rotary cooling drum having a surface finish of about 0.3 s and a surface temperature of 20 ° C. to obtain an unstretched film having a thickness of 540 m.

This unstretched film is preheated to 75 ° C and heated between the low-speed roll and the high-speed mouth by one IR heater with a surface temperature of 900 ° C from 15 mm above. Then, the film was uniaxially stretched 3.6 times in the machine direction, then quenched, and then supplied to the stenter, and stretched 3.9 times in the transverse direction at 105 ° C to obtain a biaxially oriented film. . The biaxially oriented film was heat-set at a temperature of 205 ° C. for 5 seconds to obtain a heat-set biaxially oriented film having a thickness of 38 zm. After the uniaxial stretching, an aqueous solution of 3-glycidoxypropyltrimethoxysilane was applied by a kiss coat method as an anchor treatment of the silicone.

On this heat-set biaxially oriented film, a curable silicone resin (Shin-Etsu Silicone Co., Ltd.) is used in which a platinum catalyst is added to a mixed solution of polydimethylsiloxane and dimethylhydrogensilane having a phenyl group content of 1.0 mol% or less and a platinum catalyst is added. Was dissolved in a mixed solvent of methyl ether ketone, isobutyl ketone and toluene, and silicon oxide particles were used as inorganic particles (Nippon Air Gill Co., Ltd. R972 average particle size 30 nm) ) Is added at 0.5% by weight per silicone resin component to prepare a solution with a total solid concentration of 1% by weight, and the dry film thickness is adjusted to 45 nm by the usual roll coating method. An applied release film was obtained. Heat drying by the roll coating method was performed at 150 ° C. for 20 seconds. Table 2 shows the characteristics of this release film.

Example 5

Dimethyl Terephthalate and Ethylene Dalicol as Transesterification Catalysts Using manganese acetate, antimony trioxide as a polymerization catalyst, phosphorous acid as a stabilizer, and 0.12% by weight of silicon oxide having an average particle diameter of 0.1 m as inert particles of a lubricant. Polymerized by the intrinsic viscosity (orthochlorophenol,

(35 ° C) 0.62 polyethylene terephthalate was obtained.

The polyethylene terephthalate pellets are supplied to an extruder hopper after drying at 170 for 3 hours, melted at a melting temperature of 280 to 300 ° C, and surface-finished for about 0.3 s using an extrusion die. Extruded on a rotating cooling drum at a temperature of 20 ° C, thickness 5

A 40 m unstretched film was obtained.

This unstretched film is preheated to 75 ° C, and heated vertically by a single IR heater with a surface temperature of 900 ° C from 15 mm above between the low speed roll and the high speed roll. The film was uniaxially stretched twice, quenched and then supplied to a stenter, and stretched 3.9 times in the transverse direction at 105 ° C. to obtain a biaxially oriented film. This biaxially oriented film was heat set at a temperature of 205 ° C for 5 seconds to obtain a heat fixed biaxially oriented film having a thickness of 38 zm. After uniaxial stretching, an aqueous solution of 3-glycidoxypropyltrimethoxysilane was applied by a kiss coat method as a silicone anchor treatment.

On this heat-fixed biaxially oriented film, a silicone resin (KS-774 manufactured by Shin-Etsu Silicone Co., Ltd.) of a type in which a platinum catalyst is added to a mixed solution of polydimethylsiloxane and dimethylhydrogensilane to cause an addition reaction, Dissolved in a mixed solvent of butyl ketone, isopropyl ketone and toluene, added 2% by weight of silicone oxide particles (R972 average particle size 3 Onm, manufactured by Nippon Air Gill Co., Ltd.) as inorganic particles, 2% by weight per silicone resin component. A solution having a concentration of 1% by weight was prepared, and applied by a conventional roll coating method so that the dry film thickness became 45 nm, to obtain a release film. Heat drying by the roll coating method was performed at 150 ° C for 20 seconds. Table 2 shows the properties of this release film.

Example 6

Except for using the polyethylene terephthalate prepared in Example 4 and the polyethylene terephthalate A prepared in Example 2 to produce a film having a configuration of polyethylene terephthalate Z and polyethylene terephthalate A = 36 mZ2 im, A release film was obtained in the same manner as in Example 4.

Comparative Example 4

A release film was obtained in the same manner as in Example 4, except that no inorganic particles were added to the silicone release layer of Example 1. Table 2 shows the properties of this release film.

Comparative Example 5

A release film was obtained in the same manner as in Example 4, except that the thickness of the silicone release layer in Example 4 was set to 100 nm. Table 2 shows the properties of this release film.

Comparative Example 6

A release film was obtained in the same manner as in Example 4, except that the amount of particles added to the silicone release layer in Example 4 was 30% by weight. Table 2 shows the characteristics of this release film.

Comparative Example 7

A release film was obtained in the same manner as in Example 4, except that diphenylsiloxane was added so that the diphenylsiloxane content in the release layer was 5 mol%. Table 2 shows the characteristics of this release film.

Table 2

Ra Rz hardness HD5 HDIO

t / d-flops locking of abrasion (nm) (run) xsxgi / μ ϊΆ " number / fraction ² / wicked person ²

Example 4 0.93 108 1200 70 1.5 〇例 Example 5 3.8 28 104 9600 95 2 〇実施 Example 6 0.93 108 1300 72 1.5 〇比較 Comparative Example 4 0.7.10 105 100 40 X 〇 Comparative example 5 13 48 104 8 300 180 3.3 3.3 XX Comparative example 6 26 63 102 13000 230 1.5 〇 X Comparative example 7 0.78 13 93 1100 75 1.5 X 〇

Claims

The scope of the claims

1. (a) a polyester film having a surface having a centerline average roughness Ra of 15 nm or less and a ten-point average roughness Rz of 30 to 500 nm; and

(b) a silicone release layer formed on the surface of the polyester film and having a thickness of 0.8 times or less of Rz on the surface.

A release film comprising:

2. The release film according to claim 1, wherein the exposed surface of the silicone release layer (b) has a center line average roughness Ra of 15 nm or less and a ten-point average roughness Rz of 100 to 500 nm. .

3. The release film according to claim 1, wherein the sum of the center line average roughnesses Ra of both exposed surfaces is 12 nm or more.

4. The release film according to claim 1, wherein the polyester film (a) contains inert particles having an average particle size of less than 1 m.

5. The release film according to claim 3, wherein the inert particles have an average particle size of 0.01 m or more and less than 1 m, and a ratio of major axis / minor axis is 1.0 to 1.2.

6. The release according to claim 1, wherein the silicone release layer (b) is made of polydimethylsiloxane.

7. The release film according to claim 1, wherein the silicone release layer (b) contains inert particles having an average particle size of 5 to 8 Onm.

8. Opposite side of polyester film (a) with silicone release layer (b) 2. The release film according to claim 1, further comprising another polyester layer on the surface.

9. (a ') a polyester film having a surface having a centerline average roughness Ra of 5 nm or less and a ten-point average roughness Rz of 30 nm or less; and

(b ′) formed on the surface of the polyester film and having the following formula (1)

0.3 d≤ t≤2.5 d (1)

A release film containing inert particles satisfying the following conditions and comprising a silicone release layer having a thickness of 300 nm or less.

10. The mold release film according to claim 9, wherein the exposed surface of the silicone release layer (b ') has a center line average roughness Ra of 5 nm or less and a ten-point average roughness Rz of 30 nm or less. M

11. The protrusions on the exposed surface of the silicone release layer (b ') are represented by the following formulas (2) and (3)

HD 5≥500 pcs / mm ²

HD 10≤100 pieces ^{/ mm 2 · · · (3} )

Where HD 5 is the number of protrusions that are 5 nm or more in height and HD 10 is the number of protrusions that are 10 nm or more in height.

10. The release film according to claim 9, which satisfies the following.

12. The release film according to claim 9, wherein the silicone release layer (b ') is made of an addition reaction type silicone resin composed of polydimethylsiloxane having a vinyl group and hydrogen silane.

13. The release film according to claim 9, wherein the micro-hardness of the silicone release layer (b ') is 10 Omgf or more.

14. The release film according to claim 12, wherein the polydimethylsiloxane having a vinyl group is contained in an amount of —S i (CH ₃ ) ₂ — per mol of —S i (C ₆ H ₅ ) ₂ -0.5 mol or less. .

15. The release film according to claim 9, wherein the inert particles in the silicone release layer (b ') are inorganic particles having an average particle size of 3 to 80 nm.

16. The release film according to claim 9, further comprising another polyester layer on the surface of the polyester film (a ') opposite to the surface on which the silicone release layer (b') is present.