JP2001277431A - Release film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a release film which dissolves back transfer and is useful as the protective film of an adhesive coat or for producing an adhesive sheet, a resin sheet, a resin film, or a ceramic sheet precisely. SOLUTION: In the release film, a release layer is laminated on a part or the whole of one side of a plastic film, and a belt-shaped printing layer or a vapor deposition layer is laminated on a part of the opposite side.

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 useful as a protective film for an adhesive coating, an adhesive sheet, or a carrier film for molding a resin sheet, a resin coating or a ceramic sheet. .

[0002]

2. Description of the Related Art A release film is used as a protective film for an adhesive film. For example, the pressure-sensitive adhesive film is usually manufactured by applying a coating liquid containing a pressure-sensitive adhesive and a solvent to the surface of a base film, and then heating and removing the solvent, which protects the pressure-sensitive adhesive film. Therefore, a release film is usually laminated on the surface of the film. The release film may serve as a temporary support.

[0003] Release films have also been used as carrier films for forming pressure-sensitive adhesive sheets, resin sheets, resin films or ceramic sheets. For example, as a resin sheet, a resin solution obtained by dissolving a resin such as a vinyl chloride resin in a solvent is used as a release film (carrier film).
It is manufactured by a method of coating (casting) on the top, removing the solvent by heating, and then separating and separating from the carrier film, and is used for various uses such as a sheet for a marking sheet. Further, the resin film is formed by applying a coating liquid comprising a resin such as an adhesive and a solvent to the surface of the carrier film and then heating to remove the solvent. Furthermore, the ceramic sheet is formed, for example, by coating a slurry in which ceramic powder and a binder or the like are dispersed in a solvent on a release film (carrier film), and then removing the solvent by heating to obtain a ceramic green sheet (ceramic green). Sheet).

A release film used for such an application is often coated with a resin solution, an adhesive or a ceramic slurry over the entire width or a part of the release layer surface. As a component constituting the release layer of the release film, generally, a silicone-based resin, a fluorine-based resin, an aliphatic wax or the like is used. It is excellent in terms of stable, uniform and light peeling properties and cost when peeling off the film or sheet provided on the substrate. However, while the release layer using a silicone resin has the advantage that a light peeling force can be obtained, if the peeling force is too light due to low surface energy, depending on the type of the resin solution or ceramic slurry, the coating liquid may not be applied. In some cases, it may be repelled during coating, or even if it can be applied successfully, it may be unnecessarily peeled off when peeling, making it difficult to control the peeling. In addition, if the weight is increased in consideration of wettability and light peelability, the coating film may partially remain on the release film and may not be peeled off.

Further, in the process of manufacturing a resin sheet or a ceramic sheet, the resin sheet or the ceramic sheet may be stored in a form wound up in a roll form while being laminated on a release film. When the release film is peeled off from the roll, a problem that the laminated resin sheet or ceramic sheet partially adheres to the opposite surface of the release film (rear transfer) may occur, which is not preferable in operation. .

SUMMARY OF THE INVENTION An object of the present invention is to eliminate the disadvantages of the prior art, in particular, the backside transfer, and as a protective film for an adhesive film, or as an adhesive sheet, a resin sheet, a resin film or a ceramic sheet. An object of the present invention is to provide a release film useful for manufacturing with high precision.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a plastic film having a release layer laminated on an entire surface or a part of one surface of a plastic film, and a strip-shaped printing layer formed on a part of the opposite surface. Alternatively, it is achieved by a release film characterized in that a vapor deposition layer is laminated.

The present invention further includes the following embodiments. 1. The printing layer or the vapor deposition layer is provided in parallel with the longitudinal direction of the film. 2. The printing layer or the vapor deposition layer is a printing layer, the printing layer contains a pigment or a dye, and the thickness of the printing layer is 0.01 to 2
μm range. 3. The printing layer or the vapor deposition layer is a vapor deposition layer, the vapor deposition layer is laminated by a vapor deposition method, and the thickness of the vapor deposition layer is 1 to 2000 n.
m. 4. Release force of release layer to adhesive tape is 1mN / cm
At least 2000 mN / cm. 5. The release layer is made of a curable silicone resin, and the surface of the release layer has a maximum surface tension (γLm
ax) is 30 to 100 dyne / cm. γLmax = 1 / b + γc / 2 Equation (I) (where b is a constant determined from the slope of the Zisman plot, and γc is the critical surface tension.) The print layer or the vapor deposition layer is provided only on both ends of the release film.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Plastic film In the present invention, as the plastic film, a polyester film which is excellent in heat-resistant dimensional stability, flatness, fish eye and the like of the film is preferable.

When the release film requires transparency, the polyester film is preferably a polyester film having good transparency, and more preferably a biaxially stretched polyester film. Further, when the release film is required to have concealing properties, light-shielding properties, etc., a polyester film containing a pigment is preferable, and furthermore, an inorganic pigment such as TiO ₂ , a biaxially stretched polyester film containing SiO ₂ or the like is preferable. .

The polyester constituting such a polyester film is preferably a crystalline linear saturated polyester comprising an aromatic dibasic acid component and a diol component. Specific examples thereof include polyethylene terephthalate, polypropylene terephthalate, and polybutylene terephthalate. And polyethylene-2,6-naphthalenedicarboxylate. Some of them (usually 15 mol% or less, preferably 10
(% By mole or less) or a mixture of a small amount (usually 20% by weight or less, preferably 10% by weight or less, based on the total weight) of a polyalkylene glycol or another resin. May be.

The polyesters are known per se,
This intrinsic viscosity (orthochlorophenol, 35 ° C.) is preferably 0.4 or more, more preferably 0.45 to 0.9.

The polyester film is preferably a biaxially stretched film, and the biaxially stretched film can be manufactured by a known method. For example, after drying the polyester, Tm to (Tm + 70) ° C. (however, Tm:
(Melting point of polyester), and extruded from a die (for example, T-die, I-die, etc.) onto a rotary cooling drum.
C. to 90.degree. C. to obtain an unstretched film, and then the unstretched film is cooled to (Tg-10) to (Tg + 70) .degree.
g: glass transition temperature of polyester) at a temperature in the range of 2 to 7 times in the machine direction, then in the range of 2 to 7 times in the transverse direction, and then heat at 160 to 260 ° C. for 1 to 60 seconds. It can be manufactured by fixing. The thickness of the film is not particularly limited, but is preferably 5 to 200 μm.

The plastic film according to the present invention comprises:
In order to improve the slipperiness and workability of the film, the center line average roughness (Ra) of the surface is preferably 2 nm or more and 500 nm or less. In order to make this surface roughness,
It is preferable that a lubricant such as inorganic fine particles and organic fine particles be contained in the film. More specifically, the average particle size is 0.01 nm or more and 20 μm or less, preferably 0.1
It is preferable to contain 0.001 to 10% by weight (based on the weight of the film) of inorganic fine particles or organic fine particles of not less than nm and not more than 5 μm. If the Ra of the film surface is less than 2 nm, the film will adhere to each other when the film is wound, and a problem that the film will not slip easily will occur. On the other hand, if the Ra is more than 500 nm, the resin sheet or the ceramic sheet coated on the release film will have a problem. It is not preferable because irregularities may be generated on the surface.

Specific examples of such fine particles include silicon dioxide, aluminum oxide, kaolin, calcium carbonate, titanium oxide, aluminum silicate (including calcined products and hydrates), monolithium phosphate, trilithium phosphate, and calcium phosphate. , Lithium benzoate, barium sulfate, double salts of these compounds (including hydrates), carbon black, glass powder, clay (including kaolin, benite, clay, etc.)
And inorganic fine particles such as crosslinked acrylic resin, crosslinked polystyrene resin, melamine resin, crosslinked silicone resin, and polyamideimide resin. These fine particles may be of one kind,
There may be more than one type. In order to maintain the effects of the present invention, it is preferable to use inert particles in order to prevent a change in performance due to interaction.

When the release film is required to have a hiding property, a light-shielding property and the like, a polyester film containing a pigment is preferable. For example, it can be obtained by using the following particles of a pigment or the like. It is preferable that a lubricant having a large particle size be contained as a pigment, for example, silicon oxide, titanium oxide, calcium carbonate, glass beads, silicone resin particles, crosslinked polystyrene particles, and the like. Further, these pigments preferably have an average particle size of 1 to 20 μm, and preferably contain 0.1 to 5.0% by weight based on the weight of the polyester.

In addition to the above-mentioned fine particles, a stabilizer, an ultraviolet absorber, a coloring agent, a flame retardant, an antistatic agent, a light stabilizer, an antioxidant, etc. may be used as long as the surface flatness and thermal stability of the film are not impaired. Can be incorporated into the polymer. Further, other thermoplastic resin may be added in a small amount (usually 20% by weight or less, particularly 10% by weight or less).

The plastic film may be a single-layer film or a laminated film. In the case of a laminated film, the fine particles may be contained only in the surface layer, or may be contained only in the substrate film layer (or the core layer of the laminated film of three or more layers). It may be contained in a layer. Which method to use depends on the properties that the plastic film should have, such as transparency, depending on the application.
It is better to select from surface characteristics and the like.

As a method for producing a laminated film, a coating method,
A co-extrusion method is preferred. As a coating method, a method of applying and drying a coating liquid for forming a surface layer on at least one surface of the base film at the time of film formation is preferable, and as a co-extrusion method, a plurality of extruders and a feed block or a multi-manifold die are used. A co-extrusion method is preferably mentioned. In the case of the coating method, it is preferable to use a method of thinly laminating a layer containing fine particles on at least one surface of the base film.

Printing Layer In the present invention, the printing layer to be laminated on the plastic film uses an ink that can be laminated on the plastic film and uses a conventionally known printing technique, for example, a printing method such as gravure, gravure offset, silk screen, or flexo. Stacked.

The composition of the ink is not particularly limited, but usually comprises a composition containing an adhesive, an antistatic agent, various inks for printing, and particles. For example, gravure inks mainly consist of pigments, binders and additives.

The pigments are classified into organic pigments and inorganic pigments. Examples of the organic pigments include various compounds such as nitroso pigments, nitro pigments, azo pigments and condensed polycyclic pigments. For example, metal fine particles, metal oxides, hydroxides, nitrides, sulfides, ferrocyanides,
Various compounds such as chromates, sulfates, carbonates, silicates, phosphates and the like can be mentioned.

The binder may be any resin which can be dissolved in a solvent to form a varnish, regardless of whether it is a natural resin or a synthetic resin. Specifically, acrylic resin, polyester resin, alkyd resin, polyurethane resin, maleic acid resin, vinyl chloride-vinyl acetate copolymer, ethyl cellulose derivative,
Rosin derivatives can be exemplified.

Examples of the additives include various ionic surfactants and electron conductive materials for suppressing charging during printing and traveling charging during transportation in a process, and suppress foaming during ink coating. For this purpose, a silicone oil or a fluorine-based surfactant can be used, and further, a wax or the like can be used for the purpose of imparting damage resistance, slipperiness and releasability to the cured film.

The thickness of the printing layer is preferably 0.01 to 2 μm. It is preferable that the printing layer is thin.
If it is less than 01 μm, it is difficult to make the thickness of the printed layer uniform, while if it is more than 2 μm, the printed layer rises when the film is wound into a roll, and the flatness of the film is impaired, or Problems such as occurrence of local blocking may occur, which is not preferable.

It is preferable that the printing layer itself contains a pigment or a dye so that regions having different peeling forces can be visually identified on the same release surface.

Vapor Deposition Layer In the present invention, the kind of the vapor deposition layer to be laminated on the plastic film is not particularly limited, but various kinds of metal substances including metals can be used. For example, Au,
Metals and alloys such as Ag, Cu, Al, Ni, Cr, Si,
Other examples include oxide, sulfide, and semiconductor thin film forming substances such as Sb-doped SnO ₂ and Sn-doped In ₂ O ₃ (ITO). Among these, metal Al and the like are particularly preferable in terms of cost. Note that two or more metal substances may be used in combination. As a method for forming such a deposition layer, a vapor phase growth method is preferable, and a vacuum deposition method, a sputtering method, or a plasma CVD method is more preferable. The thickness of such a layer is not particularly limited, but is preferably 1 to 2000 nm. If the thickness is less than 1 nm, a uniform film cannot be obtained, while if it exceeds 2000 nm, it is not preferable in terms of productivity.

Lamination of Printing Layer or Deposition Layer The printing layer and the deposition layer in the present invention are provided in a strip shape on a part of the surface of the plastic film opposite to the surface on which the release layer is provided. Such a band-like layer may be continuous or may be discontinuous including a region where a layer does not exist partially.
Further, the layer may be solid or may form various patterns such as dots.

The direction in which the belt-like layers are laminated is not particularly limited, but is preferably the longitudinal direction of the film. More preferably, it is preferably parallel to the longitudinal direction of the film, and more preferably, the layers are at both ends in the width direction of the release film.

In the present invention, the purpose of providing a strip-shaped layer on the surface opposite to the surface on which the release layer of the plastic film is provided is to increase the thickness by a printing layer or a vapor-deposited layer so that the resin sheet is added to the release layer on the opposite surface. Even if the product sheet such as a ceramic sheet or the like is laminated and wound up in a roll shape, a gap is created by the printing layer or vapor deposition layer, the pressure at the time of winding can be relaxed, and the printing layer or vapor deposition layer and the product sheet The purpose of the present invention is to prevent the product sheet from being back-transferred due to the blocking occurring between the sheets. Also, when a strip-shaped printing layer or a vapor-deposited layer is laminated on the same surface as the release layer, when a resin solution, an adhesive solution or a ceramic slurry is applied to the release layer surface with a gravure coater or a die coater, etc. There is a concern that the coating thickness may fluctuate due to the unevenness, or that the printing layer or the vapor deposition layer may be scraped.

Further, when applying a resin solution or ceramic slurry by coloring by printing or vapor deposition, it is effective to confirm a more accurate position by an apparatus such as an edge positioner. For such a purpose, the printing layer or the vapor deposition layer is preferably at both ends of the release film.

The order of laminating a release layer and a printing layer or a vapor deposition layer described later is not particularly limited. For example, after a release layer is laminated, a printing layer or a vapor deposition layer is laminated on the opposite surface. By doing so, a desired structure can be obtained.

The width of the printing layer or the vapor deposition layer is not particularly limited, but is preferably 0.5 mm or more and 50 mm or less when it is necessary to secure an effective coating width for collecting products. If the width of the printing layer or the vapor deposition layer is less than 0.5 mm, the film roll is likely to be displaced when wound up as a film roll, and the end faces of the roll are not uniform, and meandering or the like occurs during running. On the other hand, if it exceeds 50 mm, the ratio of the width of the printing layer or the vapor-deposited layer to the width of the release film may be large. May overlap and sticking may occur, which is not preferable.

Further, the ratio of the width of the printing layer or the vapor deposition layer to the entire width of the release film is 0.1% or more and 50% or more.
% Or less is preferable. If it is less than 0.1%, disadvantages are likely to occur in the above-mentioned winding point, which is not preferable. On the other hand, if it exceeds 50%, the yield of products such as pressure-sensitive adhesive sheets, resin sheets, and ceramic sheets may be undesirably reduced.

Release Layer The release film of the present invention has a release layer on one side of a plastic film. This release layer is not particularly limited as long as it is a material having a release property, but in terms of stable release properties and workability, it is made of a curable silicone resin containing polydimethylsiloxane as a main component. Is preferred. Further, the release layer preferably has a maximum surface tension (γLmax) determined by the following formula (I) of 30 to 100 dyne / cm. γLmax = 1 / b + γc / 2 (I) (where b is a constant determined from the slope of the Zisman plot, and γc is the critical surface tension (dyne / cm).)

In the above formula (I), b is the following Zis
is a constant determined from a man plot, and γc is a critical surface tension determined by the following method. That is, several standard solutions having a surface tension in the range of 20 to 40 dyne / cm are prepared, and these standard solutions are dropped on the release layer of the film, and the contact angle between the standard solution and the release layer (θ ) Is measured. The value of cos θ is calculated from the obtained contact angle (θ), the value of cos θ is plotted against the value of the surface tension of the standard solution (Zisman plot), and the magnitude of the slope of the straight line is defined as b. Also,
The value of the surface tension at the intersection of the straight line of the Zisman plot and the straight line indicated by cos θ = 1 is defined as γc (critical surface tension).

Here, γLmax is defined as the surface tension (dyne / cm) of the liquid which maximizes the adhesive force (W: dyne / cm) represented by the following formula (II). W = γS + γL−γSL (II) (where γS is the surface tension of the solid (dyne / cm), γL is the surface tension of the liquid (dyne / cm), and γSL is the surface tension of the solid-liquid (dyne / cm). cm).)

If the γLmax is less than 30 dyne / cm, repelling becomes large when a resin solution or slurry is applied, resulting in defects such as uneven or missing coating films and floating on coating film sheets. And may come off partly. On the other hand, when γLmax exceeds 100 dyne / cm,
The adhesion between the pressure-sensitive adhesive or sheet and the release layer becomes too large,
It becomes difficult to peel them from the release film.

In the present invention, the component of the release layer is γLm
There is no particular limitation as long as the release layer has an ax of 30 to 100 dyne / cm. For example, commercially available silicone for addition-type and / or polycondensation-type release paper having polydimethylsiloxane as a main skeleton. Is preferred. Examples of further improved wettability include those containing the following components, or the following modified silicones and organic resin-modified silicones.

(A) A silicone resin having the following structure of D unit, T unit and / or Q unit is blended in 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 blending ratio is less than 20% by weight, the wettability of the release layer may be poor, while if it exceeds 60% by weight, the release layer may be too hard and the abrasion resistance may be poor. It is not preferable because there is.

[0040]

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[0041]

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[0042]

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However, in the D unit and the T unit, R ₁ ,
R ₂ and R ₃ represent an alkyl group such as a methyl group or an aromatic hydrocarbon group such as a phenyl group.

(B) A polydimethylsiloxane polymer mixed with a silica filler such as colloidal silica to increase the surface tension by adjusting the concentration of -Si-OH groups in the release layer to be high. .

(C) Modified polydimethylsiloxane in which a methyl group in the polydimethylsiloxane polymer is partially substituted with a bulky phenyl group. Due to the steric hindrance of the phenyl group, for example, the rotational motion 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, thereby increasing the surface tension. Can be. The substitution ratio of the phenyl group is not particularly specified, but is preferably 3 to 40 mol%.

(D) As the organic resin-modified silicone,
A resin having a resin composition obtained by blending a resin mixture of an alkyd resin, an acrylic resin or a melamine resin and a silicone resin as a main component is exemplified. The alkyd resin or the acrylic resin is used alone or at a certain mixing ratio, and at least a part of the alkyd resin or the acrylic resin forms a copolymer with the silicone resin.
The melamine resin mainly acts to crosslink with the acrylic resin to cure the release layer. The alkyd resin or the acrylic resin may be mixed with a silicone resin during or after its production, and the alkyd resin or the acrylic resin may be graft-copolymerized with the silicone resin.

An alkyd resin or an acrylic resin is blended to improve the wettability of the surface of the release layer, to increase the toughness of the release layer, and to obtain an appropriate release property.

The alkyd resin has a skeleton of a condensate of a polybasic acid such as phthalic anhydride as an acid component and a polyhydric alcohol such as glycerin or ethylene glycol as a glycol component. It is a resin modified with. For example, castor oil-modified alkyd resin, soybean oil-modified alkyd resin, linseed oil-modified alkyd resin, and the like are used, and alkyd resins modified with various fatty acids can be used in any combination.

Examples of the acrylic resin include polyacrylic acids such as polyacrylic acid and polymethacrylic acid, and polymethyl methacrylate and polyethyl methacrylate. Further, higher alkyl methacrylate or a part thereof is used. For example, acrylic acid esters such as those obtained by hydroxylation can be used.

As the melamine resin, for example, methylated melamine resin, butylated melamine resin, methylated urea melamine resin and the like can be used.

As a catalyst for the crosslinking reaction between the melamine resin and the alkyd resin or the acrylic resin, for example, an acidic catalyst such as sodium p-toluenesulfonate can be used.

The silicone resin is a polymer whose basic skeleton is composed of polydimethylsiloxane, and preferably has a phenyl group, an alkyl group or the like at a terminal or a side chain in order to improve compatibility with an acrylic resin or the like. Specific examples include polyphenylpolysiloxane and hydroxyl-substituted diphenylpolysiloxane. The mixing ratio of the silicone resin is preferably 1 to 30 parts by weight of the silicone resin based on 100 parts by weight of the total amount of the melamine resin and the alkyd resin or the acrylic resin.
Particularly preferred is 10 to 10 parts by weight.

The thickness of the release layer is not particularly limited,
It is preferably from 0.01 to 3 μm, particularly preferably from 0.0
It is preferably from 5 to 1 μm. This thickness is 0.01
If it is less than μm, there is a concern that the coating of the base film with the silicone resin is not sufficient, and poor peeling may occur. On the other hand, when the thickness is more than 3 μm, the absolute amount of unreacted substances and low-molecular silicone increases, which may cause migration or blocking of the silicone.

The release force of the release layer is preferably 1 mN / cm or more and 2000 mN / cm or less, more preferably 100 mN / cm or more and 1000 mN / cm or less with respect to the pressure-sensitive adhesive tape. When the release force of the release layer is less than 1 mN / cm, the release force of the pressure-sensitive adhesive sheet, the resin sheet or the ceramic sheet is too light, and the release layer may be peeled off or partially floated. The release force of the release layer is 2000
If it is larger than mN / cm, the release force of the release layer may be so high that problems such as inability to peel off may occur.

In the present invention, the above-mentioned release layer is provided on one side of a plastic film. For example, the release layer is formed by applying a coating liquid containing a component constituting the release layer to the film. Then, it can be applied by heating, drying and curing to form a coating film. As a coating method of the coating liquid, any known coating method can be applied, and examples thereof include a roll coating method, a blade coating method, and a bar coating method, but are not limited to these methods. . Also, the release layer
It is laminated on the whole surface or one part of one side of the plastic film. When the release layer is laminated on a part of the plastic film, the position of the part where the release layer is not provided is not particularly limited, but the adhesive solution, the resin solution or the ceramic slurry or the like is applied without being thinly repelled, or high. In order to obtain a product at a yield, it is preferable that both ends of the plastic film be used.

Adhesive Layer In the present invention, in order to enhance the adhesion between the plastic film and the release layer, an adhesive layer is provided on the surface of the plastic film on which the release layer is provided, and the release layer is laminated thereon. Is preferred. For this adhesive layer, for example, a silane coupling agent can be used. As the silane coupling agent include those represented by the general formula Y-Si-X _3. Here, Y is, for example, an amino group,
X represents a functional group represented by an epoxy group, a vinyl group, a methacryl group, a mercapto group and the like, and X represents a hydrolyzable functional group represented by an alkoxy group. The preferable thickness of the above-mentioned adhesive layer is 0.01 to 5 μm, particularly 0.02 to 2 μm.

[0057]

The present invention will be further described below with reference to examples. In addition, each characteristic value of the film was measured by the following method.

(1) Peeling force between release layer and adhesive tape Nitto 31B tape (manufactured by Nitto Denko Corporation) is adhered to the release layer surface of the release film with a rubber roller, and one reciprocation is performed from above with a 20N rubber roller. And adhered. It was left as it was under the condition of a temperature of 23 ° C. and a humidity of 55 ± 5% RH for 30 minutes, and then cut into 25 mm wide strips. Using a tensile tester (Strograph manufactured by Toyo Seiki Co., Ltd.)
180mm at 300mm / min.
° and the peeling force (unit: mN /
cm).

(2) Coatability of Ceramic Green Sheet A ceramic sheet was prepared from the following materials. Various materials are mixed with a ball mill and dispersed to a Hegman grind gauge of 7 or more, and this ceramic powder dispersion slurry is coated on a release film using a straight edge applicator to a dry thickness of 10 μm. After drying at 110 ° C. for 2 minutes, the repelling state was observed and evaluated according to the following criteria. <Ceramic slurry composition> Ceramic powder 100 parts Binder: polyvinyl butyral resin 25 parts Plasticizer: dibutyl phthalate 10 parts Organic solvent 65 parts <Observation evaluation> ○: No repelling (good wettability) Δ: Repelling is slightly observed ( ×: Repelling is observed (poor wettability)

(3) Maximum surface tension of release layer (γLmax) Methyl benzoate is mixed with isopropyl acetate at an appropriate ratio to prepare several standard solutions having a surface tension in the range of 20 to 40 dyne / cm. . The surface tension is measured by the Dunuy ring pulling method. Next, this standard solution is dropped on the release layer of the film, and the contact angle (θ) between the standard solution and the release layer is determined.
Is measured. The cos θ value is calculated from the obtained contact angle (θ), a plot (Zisman plot) of the cos θ value and the surface tension measured by the above method is created, and the magnitude of the slope of the straight line is defined as b. Also, this Zis
The value of the surface tension at the intersection of the straight line of the man plot and the line indicated by cos θ-1 is defined as γc (critical surface tension). Using the thus obtained b and γc, γLmax was determined from the following formula (I). γLmax = 1 / b + γC / 2 Equation (I) where b is a constant determined from the slope of the Zisman plot, and γc is the critical surface tension determined by the above method.

(4) Thickness of Printing Layer The thickness of the printing layer and the thickness of the printing layer where the printing layer is present are measured by an electronic micrometer (manufactured by Anritsu Corporation). Assume the thickness.

(5) Thickness of Vapor Deposition Layer Using a stylus type surface roughness meter (Surfcoder 30C, manufactured by Kosaka Laboratory Co., Ltd.), the thickness of the vapor deposition layer of the film was measured under the conditions of a needle radius of 2 μm and a stylus pressure of 30 mg. The surface of the portion and the non-deposited layer portion were scanned, the displacement was measured, and the center line surface roughness was determined. The difference between the two locations was defined as the thickness of the vapor deposition layer.

(6) Blocking property On the release layer of the release film, a ceramic slurry is applied so as to have a dry thickness of 10 μm over the entire surface except for 5 mm from both ends in the same manner as in the evaluation method (2) and dried. The laminate obtained by laminating the ceramic sheets thus obtained is overlaid so that the ceramic sheets and the plastic films are alternately formed, and then pressed at a pressure of 500 N / mm ² and left at 50 ° C. for 20 hours. I do. Thereafter, the laminate is peeled off, and the situation is confirmed. ：: No sticking (ceramic sheet can be peeled off while being laminated on release surface) △: Partly sticking (ceramic sheet peels off partly from releasing surface) ×: Almost sticking (ceramic sheet is (Almost peels from the release surface)

Example 1 An intrinsic viscosity of 0.62 containing 0.1% by weight of true spherical silica particles having an average particle diameter of 0.15 μm.
The polyethylene terephthalate polymer was melted by an extruder, and was brought into close contact with a rotary cooling drum maintained at 40 ° C. from a die by using an electrostatic adhesion method, and rapidly cooled to obtain an unstretched film. Next, the unstretched film was stretched 3.5 times in the machine direction and then 3.6 times in the transverse direction,
Heat fixing was performed at 20 ° C. to obtain a biaxially oriented polyethylene terephthalate film having a thickness of 38 μm. Next, the film was slit to a width of 150 mm, and gravure printing was performed to form a strip having a thickness of 0.5 μm at each end of the film at a thickness of 20 μm.
m, the yellow pigment “SYMUL ER FAST YELL OW”
41 19 "(manufactured by Dainippon Ink and Chemicals, Inc.).

Next, 200 parts by weight of an acrylic resin (polymethyl methacrylate), 60 parts by weight of a melamine resin (butylated melamine resin) and 40 parts by weight of a silicone resin (polyphenylpolysiloxane) (a resin composed of an acrylic resin and a melamine resin) A resin composition obtained by mixing about 15 parts by weight of silicone resin with respect to 100 parts by weight of the mixture) was dissolved in a mixed solvent of toluene and methyl ethyl ketone, and a solution having a total solid content of 2% by weight was dissolved. It was created. Further, an acid catalyst (p-toluenesulfonic acid) was added to the above solution as a curing reaction accelerator to prepare a coating solution.

This coating solution was applied to the surface of the film having the printing layer formed thereon, which had been provided with the printing layer, on the opposite side to the printing layer.
The film was cured by heating and drying at 0 ° C. for 1 minute to obtain a release film having a release layer thickness of 0.1 μm. Table 1 shows the characteristics of the release film.

Example 2 A release film was obtained in the same manner as in Example 1 except that the thickness of the print layer was changed to 1.5 μm. Table 1 shows the characteristics of the release film.

Example 3 A release film was obtained in the same manner as in Example 1, except that the coating liquid used as the release layer had the following contents. Table 1 shows the characteristics of the release film. A curable silicone of the addition reaction type comprising polydimethylsiloxane having a vinyl group and dimethylhydrogensilane is dissolved in a mixed solvent of toluene and methyl ethyl ketone, and colloidal silica having an average particle diameter of 0.1 μm is added to the curable silicone. , At a solid content ratio of 0.5
% By weight to prepare a solution having a total solid content of 2%. A platinum catalyst was added to this solution to prepare a coating solution.

Example 4 The procedure of Example 1 was repeated, except that Al was evaporated to a thickness of 50 nm using a vacuum evaporator, and the coating liquid for the release layer had the following contents. A shaped film was obtained. Table 1 shows the characteristics of the release film.

A curable silicone of the addition reaction type consisting of polydimethylsiloxane having a vinyl group and dimethylhydrogensilane is dissolved in a mixed solvent of toluene and methyl ethyl ketone.
m of colloidal silica with respect to the above-mentioned curable silicone,
It was blended so as to have a solid content ratio of 0.1% by weight to prepare a solution having a total solid content of 2%. A platinum catalyst was added to this solution to prepare a coating solution.

Comparative Example 1 A release film was obtained in the same manner as in Example 1, except that a release layer was provided on the same surface as the surface on which the belt-shaped print layer was provided. Table 1 shows the characteristics of the release film.

[Comparative Example 2] A release film was obtained in the same manner as in Example 3, except that the belt-shaped printing layer was not laminated. Table 1 shows the characteristics of the release film.

Comparative Example 3 A release film was obtained in the same manner as in Comparative Example 1, except that the thickness of the printing layer was changed to 3 μm and the coating liquid for the release layer was changed to the following coating liquid. Table 1 shows the characteristics of the release film.

Curable silicone of the type in which a platinum catalyst is added to a mixed solution of polydimethylsiloxane and dimethylhydrogensilane to cause an addition reaction (Shin-Etsu Chemical Co., Ltd.)
KS847 (H)) was dissolved in a mixed solvent of toluene and methyl ethyl ketone to prepare a solution having a solid concentration of 2%. A platinum catalyst was added to this solution to prepare a coating solution.

[0075]

[Table 1]

[0076]

EFFECT OF THE INVENTION The release film of the present invention is capable of minimizing the problems of coating and peeling of a paint and having a proper wettability and peeling force. And a useful release film for producing the same.

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 4F100 AA20H AH02H AH04H AK01A AK25 AK36 AK42 AK52B AL05 AR00B AR00C BA03 BA07 BA10B BA10C BA41 CA02 CA13C CA23 EH66C GB90 HB31C JB04B JK06 JL14BYA00A

Claims (8)

[Claims] 1. A release film characterized in that a release layer is laminated on the whole surface or a part of one surface of a plastic film, and a strip-shaped printing layer or a vapor deposition layer is laminated on a part of the opposite surface. . 2. The release film according to claim 1, wherein the printing layer or the vapor deposition layer is provided in parallel with the longitudinal direction of the film. 3. The separation according to claim 1, wherein the printing layer or the vapor deposition layer is a printing layer, the printing layer contains a pigment or a dye, and the thickness of the printing layer is in the range of 0.01 to 2 μm. Shape film. 4. The printing layer or the vapor deposition layer is a vapor deposition layer, the vapor deposition layer is laminated by a vapor deposition method, and the thickness of the vapor deposition layer is 1 to 4.
3. The release film according to claim 1, which has a range of 2000 nm. 5. The release force of the release layer to the pressure-sensitive adhesive tape is 1
The release film according to any one of claims 1 to 4, which has a mN / cm of 2,000 mN / cm or more. 6. The release layer is made of a curable silicone resin, and the surface of the release layer has a maximum surface tension (γLmax) determined by the following formula (I) of 30 to 100 dyne / cm. The release film according to any one of the above. γLmax = 1 / b + γc / 2 Equation (I) (where b is a constant determined from the slope of the Zisman plot, and γc is the critical surface tension) 7. The release film according to claim 1, wherein the printing layer or the vapor deposition layer is provided only at both ends of the release film. 8. The release film according to claim 1, which is used as a carrier film for producing a ceramic green sheet.