KR20040111342A - Releasing film - Google Patents

Abstract

The present invention relates to a release film having a silicone release layer having a polyester release film having a moderate unevenness on the surface or having a release layer having a proper unevenness at a polyester base film having a flat surface.

It is a release film which has the outstanding surface property which the unevenness | corrugation of the surface of a release film is not transferred to a molded sheet, and is excellent in workability and also a favorable release property.

Description

Release film {RELEASING FILM}

The release film is used, for example, for shaping a resin sheet, for releasing pressure-sensitive adhesive, for medical use, and for producing electric and electronic parts. In a molded article such as a resin sheet molded from a release film, planarization of the surface of the molded article is an important problem. It is no exaggeration to say that the quality of the molded article molded into the film depends on the precision or quality of the surface thereof, that is, on the precision or quality of the surface of the release film.

The release film itself is formed by providing a layer of resin with mold release property, for example, a silicone resin layer, in a polyester film. Usually, although a particle | grain is mix | blended in a polyester film in order to improve workability, for example, slipperiness | lubricacy and a winding characteristic, in general, when adding particle | grains, handling property improves, but a film surface becomes rough. If the particles are not blended in order to avoid this and to form a flat surface property, the resulting film is very deteriorated in slipperiness and air bleeding properties, and wrinkles do not occur during processing, or the rolls are not wound. Moreover, when a film carries a silicone coating layer, since a silicone layer covers the processus | protrusion of the surface of a polyester film, workability will fall.

Conventionally, in a molded article or a molded sheet molded from a release film, the demand for the surface properties is not strict and even roughness of any degree does not cause a problem in quality, but in recent years, the demand for the surface properties of a molded sheet using a release film is very high. It has been strict. For example, the sheet of vinyl chloride resin or urethane resin flows and spreads these resin solutions on a release film, and shape | molds a sheet. In these sheets, especially high glossiness may be requested | required of a shaping surface. Moreover, in the release film for adhesive tapes, since the unevenness | corrugation of the surface of a release film transfers shape to the surface of the adhesive layer of an adhesive tape, when the adhesive tape was stuck to the glass surface, for example, the recessed part shape-transferred from the glass surface to the adhesive tape was carried out. Air enters and it becomes impossible to obtain a clean appearance. Therefore, strict flatness of the surface is required.

In the release film used for the process material of an electronic component, etc., the demand of surface characteristics is especially high. For example, when manufacturing the thin sheet of a ceramic capacitor, the ceramic slurry which disperse | distributed the ceramic powder and binder agent in the liquid medium is apply | coated on a release film, and the very thin sheet of 3 micrometers or less is manufactured. As the sheet becomes thinner, the surface unevenness of the release film leads directly to an increase in the defective rate of the molded sheet, so that the demand for the surface properties of the release film is increased. Moreover, even when used as a process material for display uses, the smoothing of the surface of a release film is calculated | required according to the thinning of a molded sheet.

Disclosure of the Invention

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned drawbacks of the prior art and to provide a release film having excellent surface properties in which large irregularities on the surface of the release film are not transferred to the molded sheet, and having excellent processing aptitudes and good release properties. Is in.

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 first,

(a) a polyester film having a surface having a center line average roughness Ra of 15 nm or less and a 10-point average roughness Rz of 30 to 500 nm, and

(b) a silicon release layer formed on said surface of said polyester film and having a thickness of 0.8 times or less of Rz of said surface;

It is achieved by the release film (henceforth a 1st release film of this invention) characterized by the above-mentioned.

Moreover, according to this invention, the said objective and advantage of this invention are 2nd,

(a ') Polyester film which has a surface whose center line average roughness Ra is 5 nm or less, and 10-point average roughness Rz is 30 nm or less, and

(b ') It is formed on the said surface of the said polyester film, and is following formula (1)

0.3d ≦ t ≦ 2.5d (One)

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

Silicon release layer containing inert particles satisfying

It is achieved by the release film (henceforth a 2nd release film of this invention) characterized by the above-mentioned.

Preferred Embodiments of the Invention

Hereinafter, this invention is explained in full detail. First, the first release film will be described.

The first release film is composed of a polyester film (a) and a silicon release layer (b) formed on the surface thereof.

As polyester of a polyester film (a), polyester which has aromatic dicarboxylic acid as a main acid component and aliphatic glycol as a main glycol component is used preferably. Such polyesters are substantially linear and have film formability, especially film formability by melt molding.

Examples of aromatic dicarboxylic acids include terephthalic acid, naphthalene dicarboxylic acid, isophthalic acid, diphenoxyethane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenylsulfone dicarboxylic acid, diphenylketone dicarboxylic acid and anthracene dicarboxylic acid. Can be mentioned.

Examples of the aliphatic glycols include polymethylene glycols having 2 to 10 carbon atoms such as ethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol and decamethylene glycol, and alicyclic diols such as cyclohexanedimethanol. Can be.

In the present invention, as the polyester, an alkylene terephthalate or an alkylene naphthalate as the main constituent is preferably used.

As such polyester, polyethylene terephthalate or polyethylene-2,6-naphthalate is preferable, for example. It is to be understood that this polyethylene terephthalate includes copolymers in which at least 80 mol% of the total dicarboxylic acid component is terephthalic acid and at least 80 mol% of the total glycol component is ethylene glycol, for example. Similarly, in this polyethylene-2,6-naphthalate, for example, 80 mol% or more of all dicarboxylic acid components is 2,6-naphthalene dicarboxylic acid, and for example, 80 mol% or more of all glycol components is air. It should be understood that coalescence is involved.

In the case of such a copolymer, 20 mol% or less can be set as a dicarboxylic acid component different from terephthalic acid or 2,6-naphthalene dicarboxylic acid. Examples of such other dicarboxylic acid components include aromatic dicarboxylic acids as described above; For example, alicyclic dicarboxylic acid, such as adipic acid and sebacic acid, or alicyclic dicarboxylic acid, such as cyclohexane-1, 4-dicarboxylic acid, etc. are mentioned.

In addition, 20 mol% or less of all the glycol components can be set as a glycol component different from ethylene glycol. Such other glycol components include, for example, glycols as described above; Aromatic diols such as, for example, hydroquinone, resorcin, 2,2-bis (4-hydroxyphenyl) propane; And aliphatic diols having an aromatic ring such as 1,4-dihydroxydimethylbenzene, or polyalkylene glycols (polyoxyalkylene glycols) such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol.

In the polyester of the present invention, for example, a component derived from an oxycarbonic acid such as an aromatic oxyacid such as hydroxybenzoic acid and an aliphatic oxyacid such as ω-hydroxycaproic acid is used as a dicarboxylic acid component and an oxycarboxylic acid. Copolymerization or bonding to 20 mol% or less with respect to the total amount of components is also included.

In addition, polyester has a trifunctional or higher polycarboxylic acid or polyhydroxy compound such as trimellitic acid or pentaeryte in an amount in a substantially linear range, for example, in an amount of 2 mol% or less with respect to the total acid component. The copolymer of lititol is also included.

The polyester is known per se and can be produced by a known method per se. As said polyester, the thing of 0.4-0.9 of the intrinsic viscosity measured and measured at 35 degreeC with the solution in o-chlorophenol is preferable.

In the present invention, the polyester film (a) preferably contains inert particles. The average particle diameter of the inert particles is preferably less than 1 µm, more preferably 0.01 µm or more and less than 1 µm, more preferably 0.03 µm or more and less than 1 µm. The inert particles may be either organic particles or inorganic particles, or mixed particles of organic particles and inorganic particles. Moreover, it is preferable that ratio (long diameter / short diameter) of the long diameter and short diameter of an inert particle is 1.0-1.2. By mix | blending these inert particle | grains, appropriate unevenness | corrugation can be formed in a film surface. Specific examples of such inert particles include inorganic particles such as calcium carbonate, kaolin, silicon oxide, barium sulfate, titanium oxide and alumina; And organic resin particles such as crosslinked polystyrene, crosslinked silicone resin particles, crosslinked acrylic resin particles, and crosslinked polystyrene resin 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 addition amount of such inert particle is 0.01 to 0.3 weight% with respect to polyester.

Moreover, it is preferable that a polyester film (a) has thickness of 0.1-30 times the average particle diameter of the inert particle contained in it.

When the thickness of the layer of polyester is less than 0.1 times the average particle diameter, the inert particles contained are likely to drop off, which is not preferable. Moreover, when it exceeds 30 times of an average particle diameter, it will become easy to overlap of the inert particle contained in a polyester layer, and unevenness will form easily on the surface of a film, and it is unpreferable.

The polyester film (a) has a surface whose center line average roughness Ra is 15 nm or less and 10-point average roughness Rz is 30-500 nm. When Ra exceeds 15 nm, shape transfer occurs on the surface of the molded body. Ra is preferably 1 to 13 nm.

In addition, when Rz is less than 30 nm, winding in roll form and slip with a pass roll become worse, and the handling property of a processing process becomes bad, and when it exceeds 500 nm, shape transfer arises on the surface of a molded object.

Rz becomes like this. Preferably it is 50-300 nm.

10-100 micrometers is preferable and, as for the thickness of a polyester film (a), 25-50 micrometers is more preferable.

Although the 1st release film of this invention formed the silicone mold release layer (b) mentioned later on the surface which has said Ra and Rz of a polyester film (a), it is different from the surface which forms this mold release layer (b). On the surface on the opposite side, you may have another polyester layer.

Such another polyester layer can be formed as a laminated film together with the polyester film (a). The laminated film may consist of at least two layers, preferably produced by coextrusion. In this case, although the polyester which comprises a layer may be same or different, the same thing is preferable.

If a laminated film shows another polyester layer by B layer and C layer, for example, a polyester film (a) layer / B layer, a polyester film (a) layer / B layer / polyester film ( It can take the laminated structure like a) layer or polyester film (a) layer / B layer / C layer.

In the case of laminated | multilayer film, it is preferable that inert particle is contained in the outermost layer on the opposite side to the polyester film (a) layer which forms a release layer (b), for example in the said example, B layer and C layer. In this case, the inert particles preferably have an average particle diameter of 0.1 to 1.0 mu m.

The laminated film preferably has a thickness of 10 to 100 µm, more preferably 25 to 50 µm, as a total thickness of the whole including the polyester film (a) layer.

The polyester film (a) and the laminated polyester film itself can be obtained by a method known in the art or accumulated in the art. To obtain a biaxially oriented film, for example, the polyester is melted and coextruded at a temperature of melting point (Tm: ° C) to (Tm + 70) ° C to obtain an unstretched film having an intrinsic viscosity of 0.4 to 0.8 dl / g. . Then, the unstretched film is 2.5 times or more at a temperature of (Tg-10) to (Tg + 70) ° C. (wherein Tg: glass transition temperature of polyester) in the uniaxial direction (longitudinal or transverse direction), Preferably, the film is stretched at a magnification of 3 times or more, and then stretched at a magnification of 2.5 times or more, preferably 3 times or more at a temperature of Tg to (Tg + 70) ° C in a direction perpendicular to the stretching direction. Moreover, you may extend again in a longitudinal direction and / or a lateral direction as needed. Thus, 9 times or more are preferable as an area draw ratio, 12-35 times are more preferable, and 15-25 times are especially preferable. In addition, the biaxially oriented film can be heat-set at a temperature of (Tg + 70) ° C to (Tm-10) ° C (wherein Tm: melting point of polyester), for example, preferably 180 to 250 ° C. The heat setting time is preferably 1 to 60 seconds.

In addition, in the above, when a film is a laminated film in which each layer was formed from another polyester, melting | fusing point and glass transition temperature mean the melting | fusing point and glass transition temperature of the polyester which has a higher melting | fusing point and glass transition temperature. It must be understood.

As mentioned above, the 1st release film of this invention forms the silicone release layer (b) on the surface of the polyester film (a). The silicon 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 polydimethylsiloxane, or a main component of which the compound (1) or (2) is added, and the modified polydimethylsiloxane of (3) or (4). Or it consists of the addition type silicone resin of the following (5).

(1) Silicone resin which has a structure of the following D unit, T unit, and / or Q unit in a polydimethylsiloxane polymer.

The silicone resin can be blended with polydimethylsiloxane to adjust the concentration of the methyl group in the release layer to increase the surface tension. Moreover, it is preferable that the compounding ratio of this silicone resin is 10 to 60 weight% in solid content concentration. When resin compounding quantity is 10 weight% or less, wettability may worsen and it may splash when forming a molded sheet. Moreover, in 60 weight% or more, peeling force is large and it becomes impossible to peel a molded object.

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

(2) silica filler.

By mix | blending a silica filler in a polydimethylsiloxane polymer, it can adjust so that the density | concentration of -Si-OH group in a mold release layer may become high. Moreover, it is preferable that this silica filler is 1 micrometer or less in average particle diameter. When the average particle diameter exceeds 1 µm, the film is not preferable because the film has a large haze and may be hindered when used for applications requiring transparency, or the shaping of the release layer may occur when the film is run in the processing step. . It is preferable that the compounding ratio of a silica filler is 0.01 to 1 weight% in solid content concentration. If the blending ratio is less than 0.01% by weight, the slipperiness of the roll with the silicon surface is deteriorated. If the blending ratio is more than 1% by weight, it may be shaved off from the silica filler release layer, which is not preferable.

(3) Modified polydimethylsiloxane in which a part of the methyl group in the polydimethylsiloxane polymer is substituted with a phenyl group.

By steric hindrance of the phenyl group, for example, the rotational movement around the -Si-O-Si-bond in the polymer can be suppressed, so that the surface tension can be increased because the concentration of the methyl group on the surface of the release layer is reduced. Moreover, it is preferable that the substitution ratio of this phenyl group is 10-60 mol%. When this substitution ratio is less than 10 mol%, a shaping | molding layer may be easy to be splashed and it may not apply, and when it exceeds 60 mol%, the mold release property of a mold release layer, various adhesives, and various sheets may become unsatisfactory. not.

(4) A polydimethylsiloxane polymer having a relatively high concentration of a reactive active group such as a silanol group or a methoxy group and an organic resin having a hydroxyl group in a molecule (for example, an alkyd resin, a polyester resin, an acrylic resin) can be obtained by reacting Modified polydimethylsiloxanes.

It is preferable that the ratio of the dimethylsiloxane component in this modified polydimethylsiloxane is 10-30 weight%. If this ratio is less than 10% by weight, the releasability may be poor. If it exceeds 30% by weight, transfer of silicon occurs, which is not preferable.

(5) The addition reaction type silicone resin which consists of polydimethylsiloxane and hydrogen silane which introduce | transduced a addition group, for example, a vinyl group.

The ratio of the polydimethylsiloxane having a vinyl group and the hydrogen silane is preferably such that the vinyl group in the polydimethylsiloxane is 1.0-2.0 mol relative to 1.0 mol of the -SiH group in the hydrogen silane.

By adjusting the concentration of the methyl group in the release layer, the surface tension can be increased. Therefore, you may mix | blend the silicone resin of said (1) with this silicone resin. From the viewpoint of obtaining a suitable peel force, the blending ratio of the silicone resin is at a solid content concentration, preferably 60% by weight or less, and more preferably 0.1 to 30% by weight.

The polydimethylsiloxane having a vinyl group may contain -SiAr ₂ -and -SiAr (R)-groups in addition to the -Si (CH ₃ ) ₂ -group. Here, Ar group is an aromatic hydrocarbon group, Preferably it is a phenyl group. R group is an alkyl group, Preferably it is a methyl group. In the case where the polydimethylsiloxane having a vinyl group contains a -SiPh (CH ₃ )-group or -Si (Ph) _2- , from the viewpoint of suppressing the disturbance of the molecular structure of the silicon and ensuring an appropriate peeling force and sufficient hardness, -Si (CH _{3) 2} -, based on 1 mole of the group, these groups is preferably not more than 0.5 mol. 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.

As the curing type of silicon, in addition to the thermosetting type, silicone of curing type by ultraviolet rays or curing type by electron beam may be used.

It is important that the thickness of a silicone mold release layer is 0.8 times or less of 10-point average roughness Rz of the surface of the polyester film (a) in which the silicone mold release layer was formed. When it exceeds 0.8 times of Rz, a silicone resin enters into the recessed part of the uneven part by the particle | grains in a film, and as a result, the center line average roughness Ra and the 10-point average roughness Rz of the surface of a release layer become low, and in-process It causes inconvenience due to poor handling property or blocking (backside transfer) of the release layer.

It is preferable that a silicone mold release layer contains inert particle | grains of 5-80 nm of average particle diameters. By containing this inert particle, the improvement of the handling characteristic and blocking in a favorable process can be acquired.

In the first release film of the present invention, the center line average roughness Ra of the exposed surface of the silicon release layer (b) is preferably 15 nm or less, and the 10-point average roughness Rz is 100 to 500 nm.

In the first release film of the present invention, the sum of the centerline average roughness Ra of both exposed surfaces is preferably 12 nm or more. If it is less than 12 nm, winding up in roll form and slip with a pass roll will worsen, and the processability defect of a process and blocking (backside transfer) of a release layer will arise.

A well-known various additive can be mix | blended with a mold release layer in the range which does not prevent the objective of this invention. As this additive, you may add a ultraviolet absorber, a pigment, an antifoamer, and an antistatic agent as needed, for example.

In this invention, in order to improve the adhesiveness of a polyester film (a) and a release layer (b), you may provide an adhesive layer between a polyester film (a) and a release layer (b). A silane coupling agent can be used suitably for this adhesive layer, for example. The silane coupling agents include those represented by the formula Y-Si-X _3. Here, Y is a functional group represented by an amino group, an epoxy group, a vinyl group, a methacryl group, a mercapto group, etc., for example, X represents the hydrolysable functional group represented by an alkoxy group. Preferable thickness of the said contact bonding layer is about 0.005-1 micrometer, and 0.02-0.5 micrometer is especially preferable. 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 since the polyester film provided with the adhesive layer (b) is difficult to block, trouble does not occur when handling. .

In this invention, a release layer can apply | coat and install by apply | coating the coating liquid containing the component of a mold release layer to a film, and heat-drying, for example. A well-known arbitrary coating method can be applied as a coating method of this coating liquid. As the application | coating method, although the roll coater method and the blade coater method are mentioned, it is not limited to these methods, for example. The heat drying for forming the coating layer is preferably performed at 70 to 170 ° C for 20 to 60 seconds.

Next, the 2nd release film of this invention is demonstrated.

The 2nd release film consists of a polyester film (a ') and the release film (b') formed on the surface.

As polyester of a polyester film (a '), the thing similar to the polyester described about the 1st release film can be used.

The polyester film (a ') may contain even if it contains inert particle. When it contains, the same thing as the inert particle described about the polyester film (a) of a 1st release film can be used as inert particle. These inert particles can be used individually or in combination of 2 or more types. Such inert particles can be blended at 0.2% by weight or less with respect to the polyester.

The polyester film (a ') has a surface whose center line average roughness Ra is 5 nm or less and 10-point average surface roughness Rz is 30 nm or less. If the center line average roughness Ra exceeds 5 nm, the surface smoothness is impaired in the thin-walled sheet, and if the 10-point average surface roughness Rz exceeds 30 nm, thickness mismatch occurs in the molded sheet, resulting in poor electrical properties in electronic materials. . Ra is preferably 0 to 5 nm, and Rz is preferably 3 to 30 nm.

Preferably the thickness of a polyester film (a ') is 10-100 micrometers, More preferably, it is 15-50 micrometers.

Although the 2nd release film of this invention formed the silicone release layer (b ') mentioned later on the surface which has said Ra and Rz of a polyester film (a'), it forms this release layer (b '). You may have another polyester layer on the surface on the opposite side to the surface to make. Such another polyester layer can be formed as a laminated film together with a polyester film (a '). It is understood that the description described for the first release film is applied as it is to the laminated film by replacing the polyester film (a) with the polyester film (a ').

In addition, a polyester film (a ') and the said laminated | multilayer film can be manufactured similarly to the manufacturing method described about the 1st release film.

As mentioned above, the 2nd release film of this invention forms the silicone release layer (b ') on the surface of the polyester film (a').

The silicon release layer (b ') may be formed on one side or both sides of the polyester film (a').

The release layer is preferably a polydimethylsiloxane or a main component thereof, and a mixture of the above-described components of (1) or (2) with respect to the release layer of the first release film, (3) or (4). A modified polydimethylsiloxane of) or the addition type silicone resin of the above (5). Among these, an addition type silicone resin is preferable.

In the second release film, the silicone release layer preferably has a hardness of at least 100 mgf / μm ² in the microhardness measurement. By setting hardness to 100 mgf / micrometer ² or more, blocking can be prevented and the contact area at the time of winding up a film in a roll shape can be made narrow enough, and peeling charging can be suppressed.

The thickness of a silicon release layer is 300 nm or less, Preferably it is 30-300 nm, More preferably, it is 50-200 nm. If it exceeds 300nm, it becomes easy to cause blocking. If it is less than 30 nm, peeling property will not be stabilized and peeling may become difficult, which is not preferable.

In the present invention, the silicon release layer contains inert particles. Inert particles impart many fine irregularities to the flat release layer surface. Since this unevenness | corrugation is very fine, even if the shape of an unevenness | corrugation transfers from a mold release film to a molded sheet, it does not become a level which causes inconvenience. By addition of this inert particle, transfer (blocking) to the back surface of a release layer improves, and process suitability improves.

For this purpose, the average particle diameter of the inert particles is preferably 1 to 100 nm, more preferably 3 to 80 nm, particularly preferably 3 to 50 nm. Moreover, the ratio (long diameter / short diameter) of the long diameter and short diameter of an inert particle becomes like this. Preferably it is 1.0-1.2.

Such inert particles may be either organic particles or inorganic particles, or 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, alumina, magnesium oxide, zirconium oxide; Organic resin particles, such as crosslinked polystyrene resin particle, crosslinked silicone resin particle, crosslinked acrylic resin particle, and crosslinked polystyrene resin particle, and particle | grains in which an inorganic material and an organic material take the form of a shell core structure are mentioned. In particular, in the case of fine particles, inorganic particles are preferable.

The compounding quantity of the inert particle to a silicone mold release layer becomes like this. Preferably it is 0.1-25 weight%, More preferably, it is 0.3-5 weight%. If the addition amount is less than 0.1, slipperiness or blocking of the release layer occurs, and the peeling characteristics of the release layer become unstable, which is not preferable. When it exceeds 25 weight%, transparency falls and it is easy to aggregate, and large aggregates generate | occur | produce, and it is unpreferable.

The silicone release layer is of the following formula (1):

0.3d ≦ t ≦ 2.5d (One)

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

It is necessary to satisfy.

If the thickness t (nm) of the release layer of silicon is less than 0.3 d, the inert particles may fall off, causing foreign matters. If the thickness exceeds 2.5 d, the surface may not have fine unevenness, resulting in poor slipperiness. It causes brittleness and poor peeling charging.

In the 2nd release film of this invention, it is preferable that the relationship of following formula (2) and (3) is satisfied about protrusion of the exposed surface of a release layer.

HD5 ≧ 500 pcs / mm ² ... (2)

HD10 ≦ 100 pcs / mm ² ... (3)

(Where HD5 is the number of protrusions of 5 nm or more in height and HD10 is the number of protrusions of 10 nm or more in height)

When HD5 is less than 500, it becomes unstable slipperiness | movement, and it is unpreferable since it causes handling, winding property, and peeling charging failure. When HD10 exceeds 100, the shape is transferred to the molded sheet surface, which causes uneven thickness of the sheet, which is not preferable.

In addition, HD5 and HD10 have the following relationship (2 ') and (3'):

10,000 ≧ HD5 ≧ 1,000... (2')

10≤HD10≤70... (3 ')

It is more preferable to satisfy.

The second release film of the present invention preferably has a centerline average roughness Ra of 5 nm or less and a 10-point average roughness Rz of 30 nm or less of the exposed surface of the silicon release layer (b ').

You may add an additive to the mold release layer in this invention in the range which does not prevent the objective of this invention. As this additive, a ultraviolet absorber, a pigment, an antifoamer, an antistatic agent can be illustrated, for example. Moreover, you may mix | blend such additive with resin and apply | coat this resin to the surface of a polyester film (a ') separately from a mold release layer.

In this invention, in order to improve the adhesiveness of a polyester film (a ') and a mold release layer, you may corona-process a polyester film (a'), or you may provide an adhesive layer between a polyester film (a ') and a mold release layer. It is preferable to use a silane coupling agent for an adhesive layer. As this silane coupling agent, the thing similar to what was described about the 1st release film is used. Preferable thickness of the said contact bonding layer is about 0.005-0.1 micrometer, and especially 0.01-0.1 micrometer is preferable. Adhesiveness of a polyester film (a ') and a mold release layer becomes favorable that the thickness of an adhesive layer is the said range.

Formation of a release layer can be performed similarly to the method described about the 1st release film. In addition, it should be understood that the matter which is not described about a 2nd release film is applied as the matter described about a 1st release film as it is, or changes plain to those skilled in the art.

The present invention relates to a release film. In more detail, it is related with the release film which has the outstanding surface characteristic which the unevenness | corrugation of a surface does not transfer to a molded sheet, and was excellent in workability and mold release property.

Hereinafter, the present invention will be described in more detail with reference to Examples.

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

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

It is measured using a CP-50 type Sentryfugirl Particle Size Analyzer made by Shimadzu Seisakusho. From the particle | grains of each particle size computed based on the centrifugal sedimentation curve obtained, and the integration curve of the amount of abundance, the particle size corresponded to 50 mass% is read, and this value is made into the said average particle diameter. (See Book "Granulation Techniques", Daily Industrial Newspaper, 1975, pages 242--247).

(2) Average particle diameter and long diameter / short diameter ratio of the inert particles in the film

The film sample is wrapped up with epoxy resin, the cross section is cut out to thickness of 50 micrometers, and the particle shape in a cross section is measured by TEM (transmission electron microscope).

(3) Centerline average roughness (Ra (nm)), HD5 and HD10

Contact measurement

Center line average roughness Ra is a value defined by JIS-B0601, and it measured using the tactile surface roughness meter (SURFCORDER SE-30C) of Kosaka Seisakusho Co., Ltd. Measurement conditions are as follows.

(a) stylus tip radius: 2㎛

(b) measuring pressure: 30mg

(c) cutoff: 0.25mm

(d) Measuring length: 1.0 mm

(2) Center line average roughness (Ra (nm))

Contactless measurement

Centerline average roughness (Ra) is measured using a non-contact surface roughness meter from WYKO CORPORATION NT-2000. Measurement conditions are as follows.

(a) Measurement area: 0.0462 μm

(b) Measurement magnification: 25 times

In addition, HD5 and HD10 calculate | require particle size and protrusion distribution from WYKO measurement data, and make the number of protrusions at the particle diameter of 5 nm into HD5, and the number of protrusions at the particle diameter of 10 nm to HD10.

(4) 10-point average roughness (Rz (nm))

Contact measurement

Ten-point average roughness (Rz) is a value defined by JIS-B0601, and in the present invention, a reference length is obtained from a cross-sectional curve of data obtained using a tactile surface roughness gauge (SURFCORDER SE-30C) manufactured by Kosaka Seisakusho Co., Ltd. The difference between the average value of the elevation of the summit up to the fifth and the average value of the elevation of the grain from the deepest to the fifth from the deepest part is shown.

Contactless Measurement

Ten-point average surface roughness (Rz) is measured using a non-contact surface roughness meter from WYKO CORPORATION NT-2000. Measurement conditions are as follows.

(a) Measurement area: 0.0462 μm

(b) Measurement magnification: 25 times

In any measurement method, the difference between the average value of the elevation of the calculation up to the fifth and the average value of the elevation of the valley from the deepest to the fifth is shown in the portion extracted by the reference length from the cross-sectional curve of the obtained data.

(5) Silicon film thickness measurement (Tsi (nm))

The thickness of a silicon layer is measured by cutting the cross section of a release film with a microtome, and observing the obtained sample by TEM.

(6) handling

Dynamic Friction Coefficient (S):

Two sheets of release films were stacked and placed on a glass plate, the film of the lower side (film in contact with the glass plate) of the overlapped film was drawn on a constant speed roll, and the detector was fixed to one end of the upper film to make a film / The tensile force F between films is detected. In addition, a load P of 200 g / 50 cm ² is applied to the film.

μS = F (g) / P (g)

Handling ability under μS = 1 is good ◎

μS = 1 or more and 2 or less can handle

μS = 2 or more not handled ×

blocking:

After the release film was wound 1000 times in a roll shape and aged at 60 ° C. for 1 month, the sticking phenomenon on the release surface and the back surface of the film was visually observed and evaluated according to the following criteria.

O: no blocking

×: with blocking

Sharpness:

The film surface is abraded with black drawing paper, and the occurrence of white powder is visually observed and evaluated based on the following criteria.

O: no powder

×: 100 minutes

(7) hardness measurement

As for the measurement of the hardness, the hardness of the release layer film was measured directly using ENT-1100a manufactured by Erioniks. The measurement loads 2 mgf with a triangular indenter, and calculates hardness from the deformation amount of a release layer.

Example 1

Polyethylene terephthalate A and B were prepared, polyethylene terephthalate A was used for the layer on the side which provides a release layer, and polyethylene terephthalate B was used for the other layer, and the laminated polyester film which consists of two layers is manufactured. did.

First, dimethyl terephthalate and ethylene glycol were prepared using manganese acetate as a transesterification catalyst, antimony trioxide as a polymerization catalyst, phosphorous acid as a stabilizer, and silicon oxide having an average particle diameter of 0.1 탆 as 0.3 inert particles. wt% was blended and polymerized by a conventional method to obtain polyethylene terephthalate A having an intrinsic viscosity (o-chlorophenol, 35 ° C) 0.62.

In addition, 0.05 weight% of crosslinked silicone particles (long diameter / short diameter = 1.05) of an average particle diameter of 0.5 micrometer and 0.4 weight% of aluminum oxide particles of an average particle diameter of 0.2 micrometer were mixed instead of silicon oxide as an inert particle of a lubricant. Was obtained in the same manner as the polyethylene terephthalate A, polyethylene terephthalate B was obtained.

After drying these pellets of polyethylene terephthalate at 170 ° C. for 3 hours, they are 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 finish of about 0.3 s. It extruded on the rotating cooling drum of surface temperature 20 degreeC, and obtained the unstretched two-layer laminated film of 540 micrometers in thickness.

The unstretched laminated film thus obtained was preheated to 75 ° C, further heated by one IR heater with a surface temperature of 900 ° C from 15 mm above between low and high speed rolls, stretched 3.6 times, quenched, and then stentered. Was supplied to and stretched 3.9 times in the transverse direction at 105 ° C. The biaxially oriented film thus obtained was heat-set at a temperature of 205 ° C for 5 seconds to have a thickness of 38 µm (36 µm in thickness of the polyester A layer on the side where the release layer is provided, and 2 µm in thickness of the polyester B layer on the opposite side thereof). The heat setting biaxially oriented laminated polyester film of was obtained.

Furthermore, on this film, the curable silicone (KS-847 (H) manufactured by Shin-Etsu Silicone Co., Ltd.) of the type which adds and reacts a platinum catalyst to the mixed solution of polydimethylsiloxane and dimethylhydrosilane silane, methyl ethyl ketone, iso It melt | dissolved in the mixed solvent of butyl ketone and toluene, the solution which becomes 3 weight% of total solid content was prepared, and the release film apply | coated so that dry film thickness might be set to 55 nm by the roll coating method of a normal method. Heat drying was performed at 160 degreeC for 30 second. The properties of this release film are shown in Table 1.

Example 2

The inert particles to be blended into the polyethylene terephthalate A in Example 1 were changed to 0.12% by weight of crosslinked silicon particles having an average particle diameter of 0.3 μm, and the polyethylene terephthalate B was changed to not inert particles. The polyethylene terephthalate was coextruded in a multi-manifold die so as to have an A / B / A configuration, and the extrusion amount was adjusted so that the thickness configuration was A / B / A = 2 µm / 34 µm / 2 µm. Moreover, the release layer was set to 77 nm. A release film was obtained by the method similar to Example 1 except these.

Example 3

Using only the polyethylene terephthalate A used in Example 2, the 38 micrometers film was produced, and the release layer was set to 77 nm. A release film was obtained by the method similar to Example 2 except these.

Comparative Example 1

Dimethyl terephthalate and ethylene glycol were polymerized by the conventional method using manganese acetate as a transesterification catalyst, antimony trioxide as a polymerization catalyst, and phosphorous acid as a stabilizer, and intrinsic viscosity (o-chlorophenol, 35 degreeC) the polyethylene terephthalate of 0.62 was obtained. A release film was prepared in the same manner as in Example 1 except that 0.05 wt% of silicon oxide having an average particle diameter of 1.7 μm was blended as polyethylene inert fine particles in the polyethylene terephthalate to obtain a single layer, and the thickness of the release layer was 98 nm. Got.

Comparative Example 2

The release film was obtained by the method similar to the comparative example 1 except changing the inert particle of the comparative example 1 into the particle | grains of an average particle diameter of 0.1 micrometer.

Comparative Example 3

The release film was obtained by the same method except apply | coating so that a silicon mold release layer film thickness might be set to 200 nm on the film obtained in Example 1.

TABLE 1

Example 4

First, dimethyl terephthalate and ethylene glycol were polymerized by the conventional method using manganese acetate as a transesterification catalyst, antimony trioxide as a polymerization catalyst, and phosphorous acid as a stabilizer, and intrinsic viscosity (o-chloro Phenol, 35 degreeC) The polyethylene terephthalate of 0.62 was obtained.

After pelleting this polyethylene terephthalate at 170 degreeC for 3 hours, it supplies to an extruder hopper, melts at melting temperature of 280-300 degreeC, and spin-cools about 0.3s of surface finishing and surface temperature of 20 degreeC using an extrusion die. It extruded on the drum and obtained the unstretched film of 540 micrometers in thickness.

After preheating this unstretched film to 75 degreeC and heating by one IR heater of surface temperature of 900 degreeC from 15 mm upper direction between a low speed roll and a high speed roll, it uniaxially stretches 3.6 times in the longitudinal direction, and after that It quenched and then supplied to the stenter, and extended | stretched 3.9 times transversely at 105 degreeC, and obtained the biaxially-oriented film. This biaxially oriented film was heat-set at a temperature of 205 ° C. for 5 seconds to obtain a heat-setting biaxially oriented film having a thickness of 38 μm. Furthermore, after uniaxial stretching, the aqueous solution of 3-glycidoxy propyl trimethoxysilane was apply | coated by the kiss coat method as an anchor treatment of silicone.

On this heat-setting biaxially oriented film, a curable silicone resin (KS-774 available from Shin-Etsu Silicone Co., Ltd.) of a type in which a platinum catalyst is added and reacted with a mixed solution of polydimethylsiloxane and dimethylhydrogensilane having a phenyl group of 1.0 mol% or less, It melt | dissolves in the mixed solvent of methyl ethyl ketone, isobutyl ketone, and toluene, adds silicon oxide particle | grains (R972 average particle diameter 30nm by Nippon Aerosol Co., Ltd. 30nm) as an inorganic particle, 0.5 weight% per silicone resin component, and the total solid content concentration is 1 weight% The solution to be used was manufactured, and the release film apply | coated so that a dry film thickness might be set to 45 nm by the normal roll coating method. The heat drying in the roll coating method was performed at 150 degreeC for 20 second. The properties of this release film are shown in Table 2.

Example 5

Dimethyl terephthalate and ethylene glycol were used as manganese acetate as a transesterification catalyst, 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 탆 as inert particles of the lubricant. It mix | blended and superposed | polymerized by the normal method and obtained the polyethylene terephthalate of intrinsic viscosity (o-chlorophenol, 35 degreeC) 0.62.

The polyethylene terephthalate pellets were dried at 170 ° C. for 3 hours, then fed to an extruder hopper, melted at a melting temperature of 280 to 300 ° C., and cooled by rotation at a surface finish of about 0.3 s and surface temperature of 20 ° C. using an extrusion die. It extruded on the drum and obtained the unstretched film of 540 micrometers in thickness.

The pre-stretched film is preheated to 75 ° C., uniaxially stretched 3.6 times in the longitudinal direction while heating with one IR heater having a surface temperature of 900 ° C. from 15 mm above between the low speed roll and the high speed roll, and then quenched thereafter. Then, it supplied to the stenter, and extended | stretched 3.9 times transversely at 105 degreeC, and obtained the biaxially oriented film. This biaxially oriented film was heat-set at a temperature of 205 ° C. for 5 seconds to obtain a heat-setting biaxially oriented film having a thickness of 38 μm. In addition, after uniaxial stretching, the 3-glycidoxy propyl trimethoxysilane aqueous solution was apply | coated by the kiss coat method as an anchor treatment of silicone.

On this heat-setting biaxially oriented film, a curable silicone resin (KS-774 manufactured by Shin-Etsu Silicone Co., Ltd.) of a type in which a platinum catalyst is added and reacted with a mixed solution of polydimethylsiloxane and dimethylhydrogensilane is methyl ethyl ketone and isobutyl. It melt | dissolved in the mixed solvent of ketone and toluene, and added the silicon oxide particle (R972 average particle diameter 30nm by Nippon Aerosol Co., Ltd.) as an inorganic particle by 0.2 weight% per silicone resin component, and prepared the solution which makes the total solid concentration into 1 weight%. Then, it apply | coated so that dry film thickness might be set to 45 nm by the normal roll coating method, and the release film was obtained. The heat drying in the roll coating method was performed at 150 degreeC for 20 second. The properties of this release film are shown in Table 2.

Example 6

Example 1 Using a polyethylene terephthalate prepared in Example 4 and a polyethylene terephthalate A prepared in Example 2, except that a film having a configuration of polyethylene terephthalate / polyethylene terephthalate A = 36 μm / 2 μm was prepared. The release film was obtained by the method similar to 4.

Comparative Example 4

The release film was obtained by the method similar to Example 4 except not having mix | blended inorganic particle with the silicone mold release layer of Example 1. The properties of this release film are shown in Table 2.

Comparative Example 5

A release film was obtained in the same manner as in Example 4 except that the thickness of the silicon release layer of Example 4 was set to 1000 nm. The properties of this release film are shown in Table 2.

Comparative Example 6

A release film was obtained in the same manner as in Example 4 except that the particles added to the silicon release layer of Example 4 were 30% by weight. The properties of this release film are shown in Table 2.

Comparative Example 7

The release film was obtained by the method similar to Example 4 except having added diphenylsiloxane so that diphenyl siloxane content in a mold release layer may be 5 mol%. The properties of this release film are shown in Table 2.

<Table 2>

Claims (16)

(a) a polyester film having a surface having a centerline average roughness Ra of 15 nm or less and a 10-point average roughness Rz of 30 to 500 nm, and (b) a silicon release layer formed on said surface of said polyester film and having a thickness of 0.8 times or less of Rz of said surface; Release film, characterized in that consisting of. The method of claim 1, The release film whose center line average roughness (Ra) of the exposed surface of a silicone mold release layer (b) is 15 nm or less, and 10-point average roughness (Rz) is 100-500 nm. The method of claim 1, The release film whose sum of center line average roughness (Ra) of both exposure surfaces is 12 nm or more. The method of claim 1, The release film in which a polyester film (a) contains inert particle | grains whose average particle diameter is less than 1 micrometer. The method according to claim 3 or 4, The release film whose average particle diameter of an inert particle is 0.01 micrometer or more and less than 1 micrometer, and the long diameter / short diameter ratio is 1.0-1.2. The method of claim 1, The release film in which a silicone mold release layer (b) consists of polydimethylsiloxane. The method according to claim 1 or 6, The release film in which a silicone mold release layer (b) contains inert particles of 5 to 80 nm in average particle diameter. The method of claim 1, The release film in which the other polyester layer exists further on the surface opposite to the surface where the silicone mold release layer (b) of a polyester film (a) exists. (a ') Polyester film which has a surface whose center line average roughness Ra is 5 nm or less, and 10-point average roughness Rz is 30 nm or less, and (b ') It is formed on the said surface of the said polyester film, and is following formula (1) 0.3d ≦ t ≦ 2.5d (One) (Where d is the average particle diameter (nm) of the inert particles and t is the thickness (nm) of the silicon release layer) Silicon release layer containing inert particles satisfying Release film, characterized in that consisting of. The method of claim 9, The release film whose center line average roughness (Ra) of the exposed surface of a silicone mold release layer (b ') is 5 nm or less, and 10-point average roughness (Rz) is 30 nm or less. The method of claim 9, Projections on the exposed surface of the silicon release layer (b ') are represented by the following formulas (2) and (3) HD5? 500 pieces / mm ² ... (2) HD10 ≦ 100 pcs / mm ² ... (3) (Where HD5 is the number of protrusions of 5 nm or more in height and HD10 is the number of protrusions of 10 nm or more in height) Release film to satisfy. The method of claim 9, The release film which consists of an addition reaction type | mold silicone resin which the silicone mold release layer (b ') consists of polydimethylsiloxane and hydrogensilane which have a vinyl group. The method of claim 9 or 12, The release film whose microhardness of a silicone mold release layer (b ') is 100 mgf / micrometer <^2> or more. The method of claim 12, Having a vinyl group of polydimethylsiloxane is -Si (CH _{3) 2} - 1 mol of _{-Si (C 6 H 5) 2} - release film containing more than 0.5 mol. The method of claim 9, The release film whose inert particle in a silicone mold release layer (b ') is an inorganic particle with an average particle diameter of 3-80 nm. The method of claim 9, The release film in which the other polyester layer exists further on the surface opposite to the surface where the silicone mold release layer (b ') of a polyester film (a') exists.