JP2002331614A - Mold release film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mold release film having excellent characteristics when used as a carrier film in a step of molding an anisotropic conductive film having adhesive properties or when used as a separator at the time of winding. SOLUTION: The mold release film comprises a mold release layer A formed on one side surface of a polyester film, and a mold release layer B provided on the other surface. The mold release film is used as the carrier film in the step of molding the anisotropic conductive film having the adhesive properties, and as the separator at the time of winding. The centerline mean roughness and a release force of each of the surfaces of the layers A and B are in specific ranges. The overall light ray permeability and the haze value of the mold release film are in specific ranges.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a release film, and more particularly, to a release film used as a carrier film in a step of forming an anisotropic conductive film having tackiness, or used as a separator during winding. The present invention relates to a release film having excellent characteristics.

[0002]

2. Description of the Related Art An ITO terminal on a glass substrate of a liquid crystal panel is connected to a flexible substrate or a TCP (Tapecarrie).
When connecting two circuit elements and electrically connecting the terminals between the two circuit elements as in the case of connecting to a terminal of RpScage) or in the case of flip-chip bonding a semiconductor chip on a motherboard, bonding is performed. Anisotropic conductive films having properties are widely used.

[0003] The anisotropic conductive film is formed by dispersing conductive particles in an insulating adhesive. The anisotropic conductive film is interposed between terminals of an element to be connected, and thermocompression-bonded. The bonding between the elements and the electrical connection between the terminals are performed simultaneously. The conductive particles used in the anisotropic conductive film are particles in which the surface of the polymer nucleus is substantially covered with a thin metal layer, metal particles, or particles in which both are mixed.

[0004] The method for producing this anisotropic conductive film generally involves the use of an insulating resin such as an epoxy resin and a coupling agent, a curing agent,
It is manufactured by applying and drying an adhesive varnish obtained by mixing and dispersing conductive particles in an insulating adhesive mixed with a curing accelerator on a carrier film (separator). Further, an insulating adhesive varnish containing no conductive particles is applied to the surface to form a multilayer, or an insulating adhesive varnish containing no conductive particles is applied on a carrier film, and then only the conductive particles are sprayed. Also, anisotropic conductive films manufactured by the method are used.

In any case, after the varnish is applied and dried, the carrier film is wound up, cut into an appropriate width, and provided for the above-mentioned purpose of use. An anisotropic conductive film having adhesiveness has tackiness in a normal state, so that a carrier film to be used needs to be provided with release layers on both sides. Further, when used, the carrier film and the anisotropic conductive film need to be pulled out together with the drawn-out carrier film, in other words, when the anisotropic conductive film is peeled off on the inner side and the outer side of the carrier film. It is necessary to make a difference in the peel strength of the steel. If the same release treatment is performed on both sides of the carrier film, the carrier film is taken to the roll where the anisotropic conductive film unwinds when the carrier film is pulled out, or the carrier film and the anisotropic conductive film A problem arises in that a gap is formed between the parts and the parts cannot be pulled out smoothly.

Further, when used as an adhesive anisotropic conductive film, the insulating adhesive varnish is applied to the carrier film until it is in a semi-cured state (B stage), and then is cured in a drying step. At this time, the temperature is usually 100 ° C to 20 ° C.
A polyester film is used because heat is applied for 1 minute to 30 minutes at 0 ° C. for a time. However, when a double-sided release film based on a normal transparent polyester film is used as a carrier film, an anisotropic conductive film is formed. There is a problem that not only is it difficult for air trapped between the carrier films to escape, but it is also difficult to confirm uneven thickness of the anisotropic conductive film and the dispersed state of the conductive particles.

On the other hand, a plastic film such as a polyester film is liable to be charged, and is manufactured by applying an insulating adhesive varnish containing no conductive particles onto a carrier film and then spraying only the conductive particles. In the case of an isotropic conductive film, the charging of the carrier film causes unevenness of charge on the surface of the insulating adhesive varnish, which causes a problem that when the conductive particles are sprayed, they cannot be uniformly spread.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to improve the drawbacks of the prior art and to provide a carrier film for forming an anisotropic conductive film which has little charge during feeding or running and has adhesive properties. When used as an anisotropic conductive film having no sticking air when used, the air which bites easily when the carrier film is wound with the anisotropic conductive film is easily released, and further unwinds and has adhesiveness. When the anisotropic conductive film is smoothly pulled out and heated and pressed on a circuit, etc., the carrier film can be peeled with an appropriate force. To provide.

[0009]

According to the present invention, there is provided a release film having a release layer A provided on one side of a polyester film and a release layer B provided on the other side.
The release film is used as a carrier film in a step of forming an anisotropic conductive film having adhesiveness, and is used as a separator at the time of winding, and has the following formula (1)
This is achieved by a release film characterized by simultaneously satisfying (6). 0.1 ≦ Ra ^A ≦ 1.0 (1) 0.1 ≦ Ra ^B ≦ 1.0 (2) 0 ≦ Tt ≦ 80 (3) 50 ≦ Hz ( 4) 1.5 ≦ H _B / H _A ≦ 100 (5) 0.15 ≦ H _A + H _B ≦ 7 (6) However, in the formulas (1) to (6), Ra ^A is The center line average roughness (μm) of the release layer A surface, Ra ^B is the center line average roughness (μm) of the release layer B surface, Tt is the total light transmittance (%) of the release film, and Hz is the release haze value form the film (%), H _a peel force of releasing layer a surface (N / 25 mm width), H _B represents release force releasing layer B surface (N / 25 mm width), respectively.

At least one of the release layer A and the release layer B
The release film according to the above, wherein an antistatic layer is provided between the layer and the polyester film layer, wherein the surface specific resistance value of the surface of the release layer on the side provided with the antistatic layer is 5 × 10 ^{4 to} 5 ×.
It is preferably achieved by a release film characterized in that it is 10 ¹² Ω / □.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

(Polyester) In the present invention, the polyester constituting the polyester film used as the base film is a polyester containing an aromatic dicarboxylic acid as a main acid component and an aliphatic glycol as a main glycol component. This polyester is substantially linear and can be formed into a film, but is particularly preferably a polyester that can be formed into a film by melt molding.

The aromatic dicarboxylic acid component constituting the polyester includes, for example, terephthalic acid, 2,6-naphthalenedicarboxylic acid, isophthalic acid, diphenoxyethane dicarboxylic acid, diphenyl dicarboxylic acid, diphenyl ether dicarboxylic acid, diphenyl sulfone dicarboxylic acid, diphenyl Ketone dicarboxylic acid, anthracene dicarboxylic acid and the like can be mentioned.

Examples of the aliphatic glycol component constituting the polyester include those having 2 to 10 carbon atoms such as ethylene glycol, diethylene glycol, trimethylene glycol, tetramethylene glycol, pentamethylene glycol, hexamethylene glycol and decamethylene glycol. Polymethylene glycol or 1,
Alicyclic diols such as 4-cyclohexanedimethanol can be mentioned.

In the present invention, as the polyester, alkylene terephthalate and / or alkylene-2,
Those containing 6-naphthalate as a main component are preferred.

Among these polyesters, in particular, polyethylene terephthalate and polyethylene-2,6-naphthalate, for example, 80% of all dicarboxylic acid components
A copolymer in which at least mol% is terephthalic acid and / or 2,6-naphthalenedicarboxylic acid and at least 80 mol% of all glycol components is ethylene glycol is preferred. In this case, 20 mol% or less of the total acid component can be the above-mentioned aromatic dicarboxylic acids other than terephthalic acid and / or 2,6-naphthalenedicarboxylic acid, and aliphatic dicarboxylic acids such as adipic acid and sebacic acid. An alicyclic dicarboxylic acid such as cyclohexane-1,4-dicarboxylic acid;

Further, 20 mol% or less of the total glycol component can be the above-mentioned glycols other than ethylene glycol. For example, hydroquinone, resorcinol, 2,2
Aromatic diols such as -bis (4-hydroxyphenyl) propane; aliphatic diols having an aromatic ring such as 1,4-dihydroxydimethylbenzene; polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol ( Polyoxyalkylene glycol) and the like.

Further, the polyester in the present invention includes:
For example, aromatic oxyacids such as hydroxybenzoic acid, ω-
Also included are those which copolymerize or combine a component derived from an oxycarboxylic acid such as an aliphatic oxyacid such as hydroxycaproic acid at 20 mol% or less based on the total amount of the dicarboxylic acid component and the oxycarboxylic acid component.

Further, the polyester in the present invention includes:
An amount in the range that is substantially linear, for example, 2 for the total acid component
Also included are those obtained by copolymerizing a tri- or higher functional polycarboxylic acid or polyhydroxy compound such as trimellitic acid or pentaerythritol in an amount of not more than mol%.

The polyester can be produced by a method known per se. As the polyester, those having an intrinsic viscosity of 0.4 to 0.9 dl / g, preferably 0.5 to 0.7 dl / g, measured at 35 ° C. as a solution in o-chlorophenol are preferable. More preferably, it is particularly preferably 0.55 to 0.65 dl / g.

(Polyester Film) The release film of the present invention is suitably used for forming an anisotropic conductive film having an adhesive property, and further as a separator when the anisotropic conductive film is formed into a tape. The center line average roughness of the film is preferably from 0.1 to 1.0 μm. If the center line average roughness is less than 0.1 μm, it is difficult to make the center line average roughness Ra ^A and Ra ^B of the release layer surface 0.1 μm or more. When the center line average roughness exceeds 1.0 μm, the center line average roughness Ra ^A and Ra ^B of the release layer surface is set to 1.0 μm.
It becomes difficult to:

In the present invention, the polyester film preferably has a total light transmittance of 0 to 80%.
Further, the haze value is preferably 50% or more. Outside this range, it is difficult to observe uneven thickness of the anisotropic conductive film formed on the carrier film and the dispersed state of the dispersed conductive particles, which is not preferable.

In order to simultaneously satisfy the above-mentioned ranges of the center line average roughness, the total light transmittance and the haze value of such a polyester film, a method of incorporating a filler or a pigment into the raw material polyester (kneading method), There are a method of applying a resin paint containing a filler and a pigment to the surface of the polyester film, a sand blast method, an emboss method, an etching method, and the like.

In the present invention, any of the above methods may be employed. However, in consideration of cost and quality, the release film of the present invention is a kneading method in which a filler or a pigment is previously contained in the raw material polyester. Is preferred.

The fillers and pigments contained in the polyester include titanium oxide, silicon oxide, barium sulfate,
Inorganic fillers such as aluminum oxide, magnesium oxide, calcium carbonate, kaolin, talc, etc., organic fillers such as polystyrene resin, acrylic resin, urea resin, melamine resin, etc., polyethylene, polypropylene, ethylene-propylene terpolymer, olefin ionomer And other resin fillers such as
One or more of these may be used. Further, if necessary, an antioxidant, an ultraviolet absorber, a fluorescent whitening agent and the like can be contained.

The particle size of the filler or pigment contained in the polyester is preferably in the range of 0.1 to 6.0 μm, and the content is preferably in the range of 2 to 20% by weight.

The polyester film used in the present invention is preferably a biaxially oriented film, and its thickness is 10 to 300 μm.
m, preferably 25 to 200 μm. The method for producing the biaxially oriented polyester can be obtained by a conventionally known production method.

For example, the melting point (Tm: ° C.) to (Tm + 7
0) The polyester is melt-extruded at a temperature of 0 ° C to obtain an unstretched film, and the unstretched film is uniaxially (longitudinal or transverse) at a temperature of (Tg-10) to (Tg + 70) ° C (where Tg: polyester). Glass transition temperature).
Stretching at a magnification of 5 times or more, preferably 3 times or more, and then at a temperature of Tg to (Tg + 70) ° C. at a temperature of Tg to (Tg + 70) ° C. in a direction perpendicular to the stretching direction at a ratio of 2.5 times or more, preferably 3 times or more. preferable. Further, if necessary, the film may be stretched again in the machine direction and / or the cross direction. As described above, the total stretching ratio is preferably 9 times or more as the area stretching ratio.
It is more preferably from 35 to 35 times, particularly preferably from 15 to 30 times. Furthermore, the biaxially oriented film has (Tg + 70)
C. to (Tm-10) C.
For example, it is preferable to heat set at 180 to 250 ° C. The heat setting time is preferably 1 to 60 seconds.

(Release Layer) In the present invention, a release layer A is provided on one side of the above-mentioned polyester film, and a release layer B is provided on the other side. It is necessary that the release layer A and the release layer B simultaneously satisfy the following expressions (1), (2), (5) and (6). 0.1 ≦ Ra ^A ≦ 1.0 (1) 0.1 ≦ Ra ^B ≦ 1.0 (2) 1.5 ≦ H _B / H _A ≦ 100 (5) 0 _{.15 ≦ H a + H B ≦} 7 ··· (6) in the formula, the central line average roughness Ra ^a is releasing layer a surface ([mu] m), Ra ^B is a center line average of the releasing layer B surface Roughness (μ
m), _HA is the peeling force of the release layer A surface (N / 25 mm
Width), the peel force of H _B is releasing layer B surface (N / 25 mm width)
Respectively.

When Ra ^A and Ra ^B are less than 0.1 μm,
After the anisotropic conductive film is formed on the release film (carrier film), when the film is wound into a roll, it is difficult to remove the air that has been drawn in, so that it is difficult to wind up the roll in a good shape. On the other hand, if Ra ^A and Ra ^B exceed 1 μm, the surface of the anisotropic conductive film peeled off from the carrier film becomes too rough, and is not completely wet-spread in the thermocompression bonding step, resulting in poor adhesion between elements and electrical connection between terminals. Causes poor connection. From such a viewpoint, the lower limit of Ra ^A and Ra ^B is preferably 0.2 μm, and the upper limit is preferably 0.5 μm.

The release layer having Ra ^A and Ra ^B of 0.1 to 1 μm can be obtained, for example, by providing a release layer on the polyester film surface having a center line average roughness of 0.1 to 1 μm. Can be.

Release Layer A and Release Layer B in the Present Invention
(Hereinafter sometimes abbreviated as "release layer") is not particularly limited as long as its properties satisfy the above formulas (1), (2), (5) and (6). For example, silicone resin, silicone oil, fluorine resin, fluorine oil, various waxes, polyester resin, alkyd, polyurethane, acrylic, melamine, polyvinyl acetal, and other organic resins modified with silicone or fluorine, or silicone oil, fluorine oil Alternatively, a coating liquid of a component obtained by adding various waxes to an organic resin may be used.

Among them, a curable silicone resin is preferable in terms of heat resistance. Examples of the curable silicone resin include condensation reaction type, addition reaction type, and ultraviolet or electron beam curing type. A reaction type can also be used. One of these curable silicone resins may be used alone, or two or more thereof may be used in combination. The curing reaction of various silicone resins can be shown as follows.

[0034]

Embedded image

As the above-mentioned condensation-reaction type silicone resin, for example, a polydimethylsiloxane having a terminal —OH group and a polydimethylsiloxane having a terminal —H group (hydrogensilane) are used as an organic tin catalyst (eg, an organic tin acylate catalyst). To form a three-dimensional cross-linked structure.

As the addition reaction type silicone resin, for example, polydimethylsiloxane having a vinyl group introduced into a terminal and hydrogen silane are reacted using a platinum catalyst,
Those who make three-dimensional bridge construction can be fisted.

As the UV-curable silicone resin,
For example, the most basic type uses the same radical reaction as ordinary silicone rubber crosslinking, the one that introduces an acrylic group and cures it, and the one that decomposes an onium salt with ultraviolet rays to generate a strong acid, thereby forming an epoxy ring. Those which are cleaved and cross-linked, those which are cross-linked by the addition reaction of thiol to vinyl siloxane, and the like can be used. Electron beams have higher energy than ultraviolet rays, and a radical crosslinking reaction occurs without using an initiator as in the case of ultraviolet curing.

As the curable silicone resin, those having a degree of polymerization of about 500,000 to 200,000, preferably about 1,000 to 100,000 are preferable. Specific examples thereof include KS-718 manufactured by Shin-Etsu Chemical Co., Ltd. -774, -775, -77
8, -779H, -830, -835, -837, -8
38, -839, -841, -843, -847, -8
47H, X-62-2418, -2422, -212
5, -2492, -2494, -470, -2366,
-630, X-92-140, -128, KS-723
A / B, -705F, -708A, -883, -70
9, -719, TPR-670 from Toshiba Silicone Co., Ltd.
1, -6702, -6703, -3704, -670
5, -6722, -6721, -6700, XSR-7
029, YSR-3022, YR-3286, DK-Q3-202, -203, -2 manufactured by Dow Corning Co., Ltd.
04, -210, -240, -3003, -205,-
3057, SFXF-2560, SD-7226, -7320 manufactured by Dow Corning Toray Silicone Co., Ltd.
-7229, BY24-900, -171, -312,
-374, SRX-375, SYL-OFF23, SR
X-244, SEX-290, and SILCOLASE 425 manufactured by ICI Japan Ltd. can be fisted. Also, JP-A-47-34447,
The silicone resin described in JP-B-52-40918 can also be used.

As a coating method for forming the curable silicone resin coating film on the film surface, a conventionally known method such as a bar coating method, a doctor blade method, a reverse roll coating method or a gravure roll coating method is used. it can.

Drying and curing (thermal curing, ultraviolet curing, etc.) of the coating film can be performed individually or simultaneously.
When performed simultaneously, it is preferable to perform the drying and curing at a temperature of 100 ° C. or higher. If the drying temperature is less than 100 ° C. and the curing time is less than 30 seconds, the curing of the coating film is incomplete, and the coating film tends to fall off, which is not preferable.

The thickness of the curable silicone resin coating is not particularly limited, but is preferably in the range of 0.05 to 0.5 μm. If the thickness of the coating film is thinner than this range, the releasability will decrease and satisfactory performance may not be obtained. Conversely, if the thickness of the coating film is larger than this range, curing takes a long time, which may cause inconvenience in production.

The release layer according to the present invention is used for molding the release film of the present invention for forming an anisotropic conductive film having adhesiveness, and further, for use as a separator when wound up as a tape. Layer A side (surface that can be peeled lightly)
The peel force H _A (N / 25 mm) of the release layer B and the peel force H _B (N / 25 mm) on the side of the release layer B (the surface that can be peeled heavily) can satisfy the following expressions (5) and (6) at the same time. is necessary. 1.5 ≦ H _B / H _A ≦ 100 (5) 0.15 ≦ H _A + H _B ≦ 7 (6) Formula (5) is obtained by comparing the release layer A surface side with the release layer. The ratio of the peeling force to the surface B is defined, and the expression (6) defines the peeling force level of both release surfaces of the release layer.

The value of H _B / H _{A in} the formula (5) (hereinafter referred to as “peeling force ratio”) is preferably in the range of 4 to 70. When the peeling force ratio is less than 1.5, there occurs a problem that when the anisotropic conductive film is pulled out, the film is not drawn smoothly and remains on the reel side. On the other hand, when the peeling force ratio is 10
If it exceeds 0, when the release layer B side, that is, when the anisotropic conductive film is pulled out, the peeling force on the surface where the anisotropic conductive film remains becomes too heavy. When the carrier film (separator) is peeled off after being pressure-bonded to the circuit element, a problem occurs that the carrier film (separator) cannot be peeled cleanly.

Further, since the adhesive strength of the anisotropic conductive film differs depending on the resin used for the anisotropic conductive film, the degree of curing of the resin, and the film thickness, it is necessary to adjust the anisotropic conductive film so as to satisfy the formula (6). is there. As the control of the peeling force, in addition to the above-mentioned combination of the release agent and the adjustment by the curing catalyst amount and the coating thickness,
As for the silicone release agent, at least one of the following four methods can be used.

(1) A silicone resin having the following structure of D unit, T unit and / or Q unit is blended into the polydimethylsiloxane polymer to adjust the concentration of methyl group in the release layer to increase the surface tension. What let you do. The mixing ratio of this silicone resin is 20 to 60% by weight in terms of solid content.
It is preferred that If the compounding ratio is less than 20% by weight, the wettability of the release layer may be poor, and if it exceeds 60% by weight, the release layer may be too hard and the abrasion resistance may be poor, which is preferable. Absent.

[0046]

Embedded image

In the D unit and the T unit, R represents an alkyl group such as a methyl group or an aromatic hydrocarbon group such as a phenyl group.

(2) By blending a silica filler in the polydimethylsiloxane polymer, -S in the release layer
The surface tension is increased by adjusting the concentration of i-OH groups to be higher. The silica filler has an average particle size of 1
Those having a size of μm or less are preferred. If the average particle size exceeds 1 μm, the haze of the film increases, which may hinder the use of the film in applications requiring transparency.
When the film is run in the processing step, the release layer may be shaved, which is not preferable. Further, the mixing ratio of the silica filler is preferably 0.1 to 1% by weight in terms of solid content. If the compounding ratio is less than 0.1% by weight, desired wettability may not be obtained, and if it exceeds 1% by weight, the silica filler may be shaved off the release layer and fall off, which is not preferable.

(3) Modified polydimethylsiloxane in which some of the methyl groups in the polydimethylsiloxane polymer have been replaced by bulky phenyl groups. Due to the steric hindrance of the phenyl group,
For example, the rotational movement around the -Si-O-Si- bond in the polymer is suppressed, and as a result, the concentration of methyl groups on the surface of the release layer decreases, so that the surface tension can be increased.
Incidentally, the substitution ratio of the phenyl group is preferably 20 to 60 mol%. If this substitution ratio is less than 20 mol%, the desired releasability may not be obtained, and if it exceeds 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) A polydimethylsiloxane polymer having a relatively high concentration of a reactive group such as a silanol group or a methoxy group, and an organic resin having a hydroxyl group in the molecule (eg, alkyd resin, polyester resin, acrylic resin, etc.)
And a modified polydimethylsiloxane obtained by reacting
The ratio of the dimethylsiloxane component in the modified polydimethylsiloxane is preferably from 10 to 30% by weight. If the proportion is less than 10% by weight, the releasability may be poor, and if it exceeds 30% by weight, the desired releasability may not be obtained.

(Release Film) The release film of the present invention must satisfy the following formulas (3) and (4) at the same time. 0 ≦ Tt ≦ 80 (3) 50 ≦ Hz (4) In the formulas (3) and (4), Tt is the total light transmittance (%) of the release film, and Hz is the distance. The haze value (%) of the shape film is shown.

When Tt is in the range of the formula (3) and Hz is in the range of the formula (4), the thickness unevenness of the anisotropic conductive film formed on the carrier film and the dispersed state of the dispersed conductive particles are hindered. It can be observed without.

The upper limit of the Tt value in the present invention is preferably 60, particularly preferably 20, so that the dispersion state of the conductive particles can be observed in a more favorable state. The lower limit of the Tt value is preferably as small as possible, but is preferably 10 in order to improve the mechanical properties of the polyester film and the stretchability during film formation.

The lower limit of the Hz value in the present invention is preferably 80, and particularly preferably 90, so that the dispersion state of the conductive particles can be observed in a better state. The upper limit of the Hz value is preferably as large as possible, but is preferably 99 in order to improve the mechanical properties of the polyester film and the stretchability during film formation.

For such a release film having a Tt value and an Hz value, for example, a release layer is provided on a polyester film having a total light transmittance of 0 to 80% and a haze value of 50% or more. Can be obtained by

(Antistatic Layer) In the present invention, in the step of forming an anisotropic conductive film, and further in the step of assembling an LCD and connecting semiconductor parts using an anisotropic conductive film and connecting two circuit elements. The generation of static electricity causes fatal damage. Specifically, when an anisotropic conductive film is manufactured by spraying conductive particles on an insulating adhesive varnish, the conductive film sprayed by the static electricity generated by the friction between the transport roll and the release film in the process. Particles are not evenly distributed, but are scattered in a charged pattern, and peeling charging that occurs when a tape-shaped anisotropic conductive film is pulled out in the LCD process or semiconductor component mounting process is the position at the time of bonding. The semiconductor device may be misaligned or damaged. Therefore, in the present invention, an antistatic layer can be provided on at least one surface before providing a release layer on both surfaces of the polyester film. As the antistatic layer in the present invention,
The surface specific resistance value after providing the release layer is 5 × 10 ^{4 to} 5 ×
10 ¹² Ω / □, preferably 5 × 10 ^{4 to} 5 ×
More preferably, it is 10 ⁹ Ω / □.

[0057]

The present invention will be described below in detail with reference to examples. The physical property values and characteristic values in the present invention were measured by the following methods.

(1) Center Line Average Roughness (Ra) According to JIS B0601, using a commercial precision surface roughness meter SE-3FAT manufactured by Kosaka Laboratory Co., Ltd.
μm, a load of 30 mg, a magnification of 200,000 times, a chart of 0.08 mm cut-off condition, and draw a portion of the measurement length L from the surface roughness curve in the direction of its center line,
When the roughness curve is represented by y = f (x) with the center line of the extracted portion as the X axis and the direction of the vertical magnification as the Y axis, the value given by the following equation is represented in μm. The measurement was performed four times with a reference length of 1.25 mm, and represented by an average value.

[0059]

(Equation 1)

(2) Peeling strength A polyester adhesive tape (nit 31B) was adhered to the release layer surface of the film and pressed with a 5 kg pressure roller, and then the release force (R ₁₀ ) between the release layer and the adhesive tape was removed. It was measured by a tensile tester.

(3) Residual adhesion rate The polyester adhesive tape (Knit-31B) was JIS
Cold rolled stainless steel sheet (SUS3
04) was measured for the peeling force after application, and the result was taken as the basic adhesive force (f ₀ ). Next, the new polyester pressure-sensitive adhesive tape was pressed against the release layer surface of the sample film with a 5 kg pressure roller and maintained for 30 seconds, and then the pressure-sensitive adhesive tape was peeled off.
Then, the peeled polyester pressure-sensitive adhesive tape was stuck on the stainless steel plate, and the peeling force of the bonded portion was measured to obtain a residual adhesive force (f). From the obtained basic adhesive strength (f ₀ ) and residual adhesive force (f), the residual adhesive rate was determined by using the following equation.

[0062]

## EQU2 ## Residual adhesion rate (%) = (f / f ₀ ) × 100

(4) Surface Specific Resistance Using a specific resistance measuring device manufactured by Takeda Riken Co., Ltd.
The surface specific resistance value was measured after 1 minute at an applied voltage of 500 V under the conditions of ° C and a measurement humidity of 65% RH and 45% RH.

(5) Total light transmittance The total light transmittance was measured using a haze meter (wavelength: 580 nm) manufactured by Nippon Seimitsu Optical Co., Ltd. with the antistatic layer side facing the light source.

(6) Haze value A haze value was measured using a haze meter (wavelength: 580 nm) manufactured by Nippon Seimitsu Optics with the antistatic layer side facing the light source.

(7) Glass transition temperature (Tg) 10 mg of a sample was set in a DSC device (differential scanning calorimeter) manufactured by PerkinElmer, and the sample was heated at a temperature of 300 ° C. for 5 minutes.
After melting for 1 minute, the sample was quenched in liquid nitrogen, and the quenched sample was heated at a rate of 10 ° C./min to measure a glass transition temperature (Tg).

(8) Melting point (Tm) A sample (10 mg) was set in a DSC apparatus (differential scanning calorimeter) manufactured by PerkinElmer, and the sample was heated at a temperature of 300 ° C. for 5 minutes.
After melting for 1 minute, the sample was quenched in liquid nitrogen, and the quenched sample was heated at a rate of 10 ° C./minute to measure the melting point (Tm).

(9) Surface state of conductive film Release film wound in a roll (film width: 1.2
m, length: 500 m), a film for a conductive film having the following composition is applied on the surface of the release layer A, and then
The mixture was heated at 20 ° C. for 5 minutes to evaporate the solvent and semi-cured the conductive film to form a 20 μm-thick conductive film, which was then rolled up again. After keeping the roll at 20 ° C. for 24 hours, it was unwound and the surface of the conductive film 10 m ² (sample 10 m long excluding the portions 0.1 m from both ends of the film) formed on the release layer A surface. The state was observed and evaluated according to the following criteria. ：: 1 m dent due to air entrainment on conductive film surface
Less than one place per ^{2 on} average. (Good conductive film surface condition) ×: 1 m dent due to air entrainment on conductive film surface
² or more places on average. (Defective conductive film surface condition)

<Coating Film for Conductive Film> An adhesive resin composition having the following composition was adjusted to have a solid content of 30%, and conductive particles having an average particle size of 5 μm, which were plated with Au on PMMA fine particles, were added to the adhesive resin solution. Monodispersion was performed so that the solid content volume ratio was 25% to obtain a conductive film paint. 100 parts by weight of liquid epoxy resin (Epicoat 828, manufactured by Yuka Shell Epoxy) 200 parts by weight of phenoxy resin (PKHH, manufactured by Union Carbide) 200 parts by weight Curing agent (Amicure PN-23, manufactured by Ajinomoto Fine Techno Co.) 30 parts by weight Solvent (MEK) / Ethyl acetate / toluene = 1/1/1) 1200 parts by weight

(10) Conductive film peeling state In the same manner as in the above (9) Evaluation of the conductive film surface state, the film was unwound from a roll formed of a conductive film and held at 25 ° C. for 48 hours, and the release layer B surface 10 m ² ( From both ends of the film.
The surface condition of the sample (10 m long except for the 1 m portion) was observed and evaluated according to the following criteria. ：: No conductive film present on the release layer B surface is observed.
(Good peeling state of conductive film) ×: One or more conductive films on surface of release layer B are observed. (Defective conductive film peeling state)

(11) Comprehensive Evaluation The following criteria were used to evaluate. ：: Both the conductive film surface state and the conductive film peeling state are good
(Good overall evaluation) ×: Either the conductive film surface state or the conductive film peeling state is defective (Comprehensive evaluation failure)

Example 1 A polyester made from terephthalic acid and ethylene glycol (intrinsic viscosity: 0.1
63 dl / g, Tg: 79 ° C., Tm: 253 ° C.) 90% by weight and 10% by weight of titanium oxide (average particle size: 0.25 μm) are melt-extruded on a rotating cooling drum maintained at 20 ° C. The film was unstretched, then stretched 3.6 times in the machine axis direction, and subsequently stretched 3.9 times in the transverse direction to obtain a biaxially stretched polyester film having a thickness of 100 μm. A release coating A (for release layer A) having the following composition was sequentially applied to one side of the film, and a release coating B (for release layer B) having the following composition was sequentially applied to the opposite side to obtain a double-sided release film. The curing condition of the release coating was 150 ° C. × 30 seconds, and the thickness of the release layer was applied to both sides to be 0.2 μm. Table 1 shows the characteristics of the release film.

<Release paint A> KS-847H (Shin-Etsu Chemical Co., Ltd.) 100 parts Solvent (toluene / MEK = 1/1) 1400 parts PL-50T 2 parts <Release paint B> BY24-400 (Toray)・ Dow Corning Silicone Co., Ltd.) 100 parts Solvent (toluene / MEK = 1/1) 1400 parts SRX-212 (Toray Dow Corning Silicone Co., Ltd.) 2 parts

Example 2 A double-sided release film was prepared in the same manner as in Example 1 except that release coating C (for release layer B) was used instead of release coating B. Table 1 shows the characteristics of the release film. The paint C has the following composition.

<Release coating C> KS-847H (Shin-Etsu Chemical Co., Ltd.) 100 parts by weight KS-3800 (Shin-Etsu Chemical Co., Ltd.) 25 parts by weight Solvent (MEK / toluene = 1) / 1) 1400 parts by weight PL-50T 2 parts by weight

Example 3 A double-sided release film was prepared in the same manner as in Example 1 except that release coating D (for release layer B) was used instead of release coating B. Table 1 shows the characteristics of the release film. The coating material D has the following composition.

<Release paint D> KS-847H (Shin-Etsu Chemical Co., Ltd.) 100 parts by weight KS-3800 (Shin-Etsu Chemical Co., Ltd.) 50 parts by weight Solvent (MEK / toluene = 1/1) ... 1400 parts by weight PL-50T ... 2 parts by weight

Example 4 0.2% by weight of silica particles having an average particle size of 5.0 μm and 6% by weight of titanium oxide particles having an average particle size of 0.25 μm were prepared from terephthalic acid and ethylene glycol. Polyester (intrinsic viscosity: 0.6
3dl / g, Tg: 79 ° C, Tm: 253 ° C) 93.8
A biaxially stretched polyester film was prepared in the same manner as in Example 1 except that the polyester was used in an amount of 1% by weight, and a release layer was provided to obtain a release film. Table 1 shows the characteristics of the release film.

Example 5 Release paint B in Example 1
Before coating, the antistatic layer shown below is
A release film was obtained in the same manner as in Example 1 except that the release coating B was provided. Table 1 shows the characteristics of the release film.

<Antistatic paint> Colcoat SP-2014 (Colcoat) 100 parts Tetraethyl silicate (Wako Pure Chemical Industries) 10 parts Water 100 parts Surfactant 20 parts

Comparative Example 1 A release film was prepared in the same manner as in Example 1 except that release coating A (for release layer B) was used instead of release coating B. Table 1 shows the performance of this release film.
Shown in

Comparative Example 2 A release film was obtained in the same manner as in Example 1 except that a polyester containing 0.01% by weight of silica particles having an average particle diameter of 1.2 μm was used. Table 1 shows the characteristics of the release film.

[0083]

[Table 1]

In the measurement planes shown in Table 1, surface A indicates the surface of the release layer A, and surface B indicates the surface of the release layer B.

As is clear from Table 1 and the description of the examples and comparative examples, the release film according to the present invention is used as a carrier film in the step of forming an anisotropic conductive film having an adhesive property, or when it is rolled. It has excellent characteristics when used as a separator at the time of removal.

[0086]

According to the present invention, there is provided a release film having excellent properties when used as a carrier film in the step of forming an anisotropic conductive film having adhesiveness, or when used as a separator during winding. Can be provided.

Continued on the front page F term (reference) 4F100 AA17D AA17E AA20A AA21A AK01D AK01E AK42A BA03 BA04 BA05 BA07 BA10B BA10C DE01D DE01E GB90 JG01D JG01E JG03D JG03E JG04 JL14B JL14C YY00A

Claims (4)

[Claims] 1. A release layer A on one side of a polyester film
A release film provided with a release layer B on the other surface, wherein the release film is used as a carrier film in a step of forming an anisotropic conductive film having adhesiveness, and is wound up. Sometimes used as a separator, the following formula (1)
A release film characterized by satisfying (6) at the same time. 0.1 ≦ Ra ^A ≦ 1.0 (1) 0.1 ≦ Ra ^B ≦ 1.0 (2) 0 ≦ Tt ≦ 80 (3) 50 ≦ Hz ( 4) 1.5 ≦ H _B / H _A ≦ 100 (5) 0.15 ≦ H _A + H _B ≦ 7 (6) However, in the formulas (1) to (6), Ra ^A is The center line average roughness (μm) of the release layer A surface, Ra ^B is the center line average roughness (μm) of the release layer B surface, Tt is the total light transmittance (%) of the release film, and Hz is the release haze value form the film (%), H _a peel force of releasing layer a surface (N / 25 mm width), H _B represents release force releasing layer B surface (N / 25 mm width), respectively. 2. An antistatic layer is provided between at least one of the release layers A and B and the polyester film, and the surface of the release layer on the side where the antistatic layer is provided has a surface resistivity of 5 ×.
2. The release film according to claim 1, wherein the release film is 10 ^{4 to} 5 × 10 ¹² Ω / □. 3. The polyester film is prepared by adding titanium oxide particles having an average particle size of 0.1 to 0.5 μm to 0 to 15 wt.
%, Silica particles having an average particle diameter of 2 to 6 μm are 0.2 to 2 watts.
3. The release film according to claim 1, which contains t%. 4. The release film according to claim 2, wherein the antistatic layer contains at least one selected from the group consisting of a conductive polymer, metal oxide fine particles, and a polymer to which a quaternary ammonium salt is added.