JP2003292895A - Polysiloxane composition and releasing film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polysiloxane-containing coating material, and a releasing film using the coating material. <P>SOLUTION: The polysiloxane coating material comprises (A) 100 pts.wt. polysiloxane having at least two unsaturated groups in the molecule, (B) 0.1-40 pts.wt. hydrogenpolysiloxane having at least two hydrogen atoms directly bonded to a silicon atom in the molecule, (C) a catalytic amount of a platinum family metal catalyst, (D) 0.1-20 pts.wt. compound to be represented by the formula (1): CH<SB>2</SB>=CH-R<SB>1</SB>-Si-[O-N=C(R<SB>2</SB>)(R<SB>3</SB>)]<SB>3</SB>(wherein R<SB>1</SB>is a 1-10C alkylene group; and R<SB>2</SB>and R<SB>3</SB>are each a 1-4C alkyl group), (E) 100-10,000 pts.wt. nonpolar organic solvent capable of dissolving the polysiloxane (A), and (F) 5-70 pts.wt., based on 100 pts.wt. component (E), alcohol to be represented by the formula (2): R<SB>4</SB>-OH (wherein R<SB>4</SB>is a 2-5C alkyl group) and/or an ester to be represented by the formula (3): R<SB>5</SB>COOR<SB>6</SB>(R<SB>5</SB>is a 1-4C alkyl group; and R<SB>6</SB>is a 1-5C alkyl group). The releasing film is produced by using this polysiloxane coating material. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polysiloxane-based coating agent and a release film obtained by using the same, and more specifically, a polysiloxane-based coating for producing a release film used for coating a plastic substrate. And a release film having a silicone release layer formed by the coating agent.

[0002]

2. Description of the Related Art Conventionally, as a release film, there has been proposed a plastic film having releasability provided on the surface thereof. Among them, a polyester film, particularly a polyethylene terephthalate film having releasability provided on the surface has been proposed. It has been used a lot. Examples of such a release film include those provided with a release layer composed of a silicone composition, a fluorine composition, an aliphatic wax composition, etc. on the surface of the film. Many proposals have been made regarding a polyester film in which is used as a release layer.

An example of such a proposal is, for example, one in which a silicone release layer is provided on a silane coupling agent cross-linking layer provided on a polyester film (JP-A-64).
No. 5838), a curable silicone cured film is provided on a plastic film via a thin layer of isocyanate silane (JP-A-3-106645), and one side of a polyester film is unsaturated in the molecule.
An aqueous coating liquid containing a composition comprising a silicone compound having a heavy bond and a graft reaction accelerator is applied, dried and heat-treated to form a release coating film (JP-A-8-11857).
No. 3), a release film containing an addition polymerization type silicone resin as a main component on one side of a polyester film (Japanese Patent Application Laid-Open No. 9-239914), and a silicone release layer containing polydimethylsiloxane having a vinyl group. A silicone layer obtained by addition-polymerizing a hydrogensilane compound with a platinum catalyst (Japanese Patent Laid-Open No. 11-268194) is known.

Further, as the coating agent for producing such a release film, for example, organosiloxane for forming a releasable cured film (JP-A-2-145649, JP-A-2-145650), 1 A composition comprising an organohydrogenpolysiloxane containing one or more alkenyl groups and two or more silicon-bonded hydrogen atoms in its molecule as a crosslinking component (JP-A-5-171047), 2
A siloxane composition composed of an organopolysiloxane containing at least one alkenyl group and an organohydrogenpolysiloxane, and an organoalkoxysilane containing a methacryloxy group or an acryloxy group and an organoacyloxysilane containing an alkenyl group.
16941), an alkenyl group-containing organosiloxane, an organohydrogensiloxane containing an alkyl group and two or more silicon-bonded hydrogen atoms, a non-reactive organohydrogensiloxane, etc. Siloxane composition (JP-A-6-49413) An organopolysiloxane composition containing an organosiloxane having at least two acryloxyalkyl groups bonded to a silicon atom in one molecule (JP-A-9-77979). ) Is known.

[0005]

However, the above-mentioned coating material and composition have the following problems.

The release film is used as a film for protecting the surface of an adhesive layer of acrylic, vinyl chloride, vinyl acetate, natural or synthetic rubber, etc., and in some practical cases, the release film is peeled off before use. . Also,
The release film is also used as a process film used when forming a green sheet or a plastic sheet. For example, a green sheet is manufactured by applying a slurry prepared by dispersing ceramic powder and a binder polymer in a solvent onto a process film (release film) and removing the solvent. Further, various plastic sheets are produced by applying a solution in which a polymer is dissolved onto a release film and removing the solvent.

In the above applications, the release layer of the release film has good releasability from a green sheet or a plastic sheet, durability against solvents used in various steps (solvent resistance), an adhesive layer, etc. Various properties are required, such as less transfer of the release layer component to (rear transfer property) and good adhesion to the base film. Further, the coating agent used for producing the release film is required to have good storage stability and good coatability. For example, in the case of process films for green sheets, poor solvent resistance causes an increase in release force and release of the release layer due to deterioration of the release layer. cause. In addition, in the case of use as an adhesive layer protective film, an increase in the amount transferred to the back side causes a decrease in the adhesive strength of the adhesive layer, and also causes retransfer from the adhesive layer, resulting in poor adhesion and
Poor solvent resistance can cause the release layer to fall off.

All the properties required of the release layer and the coating composition shown above should be well balanced, but in the conventional release film or the coating composition for producing the release film, all the characteristics are required. The characteristics were not satisfied.

For example, in the above-mentioned JP-A-8-118573, an aqueous coating solution containing a composition comprising a silicone compound and a graft reaction accelerator is applied to form a release coating film. Adhesiveness, back migration and solvent resistance are not satisfactory. In Japanese Patent Laid-Open No. 9-239914, a release layer containing an addition polymerization type silicone resin as a main component is provided on the film for the purpose of improving the peeling force and stability over time, but the adhesion to the film is not satisfactory. There wasn't. JP-A No. 11-268194 discloses a silicone obtained by addition-polymerizing a polydimethylsiloxane having a vinyl group in a silicone release layer and a hydrogensilane-based compound with a platinum catalyst for the purpose of improving the peeling force and reducing the amount transferred to the back surface. Although a release film as a layer is proposed, this method also has a problem of poor adhesion to the film. On the other hand, JP-A-64-5838 and JP-A-3-1-1.
In Japanese Patent Application Laid-Open No. 06645, Japanese Patent Application Laid-Open No. 3-120042, Japanese Patent Application Laid-Open No. 10-29288, etc., it is proposed to provide a silicone mold release layer on a polyester film on which a primer layer made of a silane coupling agent is provided. There is. These improve the adhesion between the base film and the silicone release layer due to the primer layer effect, but in addition to complicating the process, in the former three applications, part of the silane coupling agent is used in the coating process. There is a problem of evaporation and contamination in the process.

Further, regarding the prior art relating to the coating agent for producing the release film, for example, Japanese Patent Application Laid-Open No. 2-14.
Although the organosiloxane for forming a releasable cured film proposed in Japanese Patent Publication No. 5649 and Japanese Patent Application Laid-Open No. 2-145650, is cured at a relatively low temperature and forms a cured film having excellent releasing performance on various substrates. However, there is a problem in that the adhesion to the substrate is poor and the film is likely to fall off the substrate. On the other hand, in JP-A-5-171047 and JP-A-6-49413, an alkenyl group (or an alkyl group) and a silicon atom-bonded hydrogen atom are combined for the purpose of improving the adhesiveness and the releasability. We have proposed a polysiloxane composition containing a non-reactive polysiloxane with hydrogen polysiloxane as a cross-linking component, but the adhesiveness to a plastic film is not always satisfactory and the rear surface migration is poor. It was On the other hand, JP-A-6-169412 and JP-A-9-
In Japanese Patent No. 77979, an alkenyl group-containing organopolysiloxane composition containing a silane coupling agent, an organopolysiloxane composition containing an acryloxyalkyl group-bonded organosiloxane, etc., for the purpose of enhancing adhesion to a film. I'm proposing something,
Although the adhesion is improved, there is a drawback that the peeling force is increased.

Further, as a drawback common to conventional polysiloxane-based coating agents, the pot life of the coating agent is relatively short and it is difficult to handle in the manufacturing process, and the organic solvent capable of dissolving the polysiloxane-based polymer is Since it has a very high insulating property and has a low ability to neutralize the electric charges on the surface of the film base material that has been triboelectrically charged, it has been a problem that the leveling property to the base material is poor.

As described above, the conventional release film does not have the required characteristics in a well-balanced manner.

The present invention has improved these drawbacks, and has a polysiloxane-containing coating agent which is less deteriorated with time and is excellent in coating property on a plastic film substrate, and peeling force, solvent resistance, rear surface transferability and substrate adhesion. It is an object of the present invention to provide a release film having an extremely thin release layer excellent in heat resistance.

[0014]

To achieve the above object, the polysiloxane coating composition of the present invention mainly has the following constitution. That is, A) 100 parts by weight of a polysiloxane having at least two unsaturated groups in one molecule, and B) a hydrogen polysiloxane having at least two hydrogen atoms directly bonded to silicon atoms in one molecule. 40 parts by weight, C) catalytic amount of platinum group metal-based catalyst, D) the following chemical formula
0.1 to 20 parts by weight of the compound represented by [Chemical Formula 1], and E) a non-polar organic solvent capable of dissolving polysiloxane A) 100 to 1
0000 parts by weight and F) alcohols represented by the following chemical formula [Chemical formula 2] and / or esters represented by the following chemical formula [Chemical formula 3] to 5 parts by weight relative to 100 parts by weight of the component E).
It is a polysiloxane-based coating material containing about 70 parts by weight.

[0015]

[Chemical 4] (R ₁ is an alkylene group having 1 to 10 carbon atoms, R 2, R ₃
Represents an alkyl group having 1 to 4 carbon atoms. )

[0016]

[Chemical 5] (R ₄ represents an alkyl group having 2 to 5 carbon atoms.)

[0017]

[Chemical 6] (R ₅ represents an alkyl group having 1 to 4 carbon atoms, and R ₆ represents an alkyl group having 1 to 5 carbon atoms.) The release film of the present invention mainly has the following constitution. That is, it is a release film in which a release layer is provided by applying a coating agent containing the above polysiloxane coating agent on at least one side of a plastic film, drying it, and then heat treating it.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, 100 parts by weight of a polysiloxane having at least two unsaturated groups in one molecule,
Hydrogen polysiloxane having at least two hydrogen atoms directly bonded to silicon atoms in one molecule 0.1 to 4
0 part by weight, a catalytic amount of a platinum group metal-based catalyst, a compound represented by the following chemical formula [Chemical formula 1], a non-polar organic solvent capable of dissolving polysiloxane 100 to 10,000 parts by weight, F) the following chemical formula [Chemical formula 2] Alternatively, there is provided a polysiloxane-based coating material comprising the organic solvent represented by [Chemical Formula 3] in an amount of 5 to 70 parts by weight based on 100 parts by weight of the nonpolar organic solvent.

[0019]

[Chemical 7] (R ₁ is an alkylene group having 1 to 10 carbon atoms, R 2, R ₃
Represents an alkyl group having 1 to 4 carbon atoms. )

[0020]

[Chemical 8] (R ₄ represents an alkyl group having 2 to 5 carbon atoms.)

[0021]

[Chemical 9] (R ₅ represents an alkyl group having 1 to 4 carbon atoms, and R ₆ represents an alkyl group having 1 to 5 carbon atoms.) In the present invention, at least two unsaturated groups are contained in one molecule. Weight average molecular weight Mw of polysiloxane having
Of 10000 to 1000000 is provided.

As another aspect of the present invention, a release agent provided with a release layer is formed by applying a coating agent containing a polysiloxane coating agent on at least one side of a plastic film, drying it, and then heat treating it. A mold film is provided.

Furthermore, the present invention provides a release film, wherein the plastic film is a polyethylene terephthalate film or a polyethylene-2,6-naphthalate film.

Further, in the present invention, when the release layer is provided, the release layer-forming coating agent is applied to at least one surface of the plastic film before the crystal orientation is completed, and then stretched and heat-treated in at least one direction to crystallize. A release film is provided which is obtained by completing the orientation.

Further, the present invention provides a release film produced by corona-treating a plastic film before completion of crystal orientation and then applying a release layer-forming coating agent. .

Further, in the present invention, the release layer has a thickness of 0.0.
A release film is provided that is 1 to 0.3 microns. Hereinafter, the present invention will be described in more detail.

The polysiloxane having at least two unsaturated groups in one molecule of the component (A) in the present invention is the main ingredient of the coating agent for producing a release film, and imparts release characteristics to the release layer. It has a role to play. Examples of the unsaturated group include vinyl group, propynyl group, butynyl group,
Examples thereof include alkenyl groups such as pentenyl group, hexenyl group and heptenyl group, but are not limited thereto.

The average unit formula of polysilosan used in the present invention can be represented, for example, by the following chemical formula.

[0029]

[Chemical 10] In the formula, R is an alkyl group such as a methyl group, an ethyl group, a propyl group, and a butyl group; an alkenyl group such as a vinyl group, a propynyl group, a butynyl group, a pentenyl group, a hexenyl group, and a heptenyl group; a phenyl group, a tolyl group, and a xylyl group. An aryl group such as a group; a substituted or unsubstituted monovalent hydrocarbon group exemplified by a substituted alkyl group such as a 2-phenylethyl group, a 2-phenylpropyl group, and a 3,3,3-trifluoropropyl group. is there. The organopolysiloxane may contain a small amount of silicon atom-bonded hydroxyl groups or alkoxy groups.

The weight average molecular weight Mw of the polysiloxane used in the present invention is preferably 10,000 to 1,000,000, and more preferably 100,000 to 10,000.
00 is good. When the Mw of the polysiloxane is less than 10,000, the adhesion of the cured coating film formed on the base material to the base material decreases, and the resistance of the coating film to an organic solvent, that is, the solvent resistance decreases. Further, when the molecular weight of the polysiloxane is larger than 1,000,000, the viscosity becomes high and the handling becomes difficult. When the Mw of the polysiloxane is less than 10,000, the cause of the above-mentioned drawbacks is that the chain length of the siloxane polymer is shortened and the degree of entanglement of the molecular chains is reduced, thereby lowering the coating strength. To be In addition, the Mw of the polysiloxane was determined by the GPC method as a polystyrene-equivalent weight average molecular weight.

Specific examples of this component include dimethylbutenylsiloxy group end-blocked dimethylpolysiloxane, dimethylpentenylsiloxy group endblocked dimethylpolysiloxane, dimethylhexenylsiloxy group endblocked dimethylpolysiloxane, dimethylheptenylsiloxy group endblocked. Dimethylpolysiloxane, dimethyloctenylsiloxy group end-capped dimethylsiloxane, trimethylsiloxy group endblocked butenylmethylsiloxane / dimethylsiloxane copolymer, silanol group endblocked butenylmethylsiloxane / dimethylsiloxane copolymer, trimethylsiloxy group endblocked Methyl pentenyl siloxane / dimethyl siloxane copolymer, trimethylsiloxy group end-capped hexenyl methyl siloxane / dimethyl siloxane copolymer,
Silanol group end-capped hexenylmethylsiloxane / dimethylsiloxane copolymer, trimethylsiloxy group end-capped methylheptenylsiloxane / dimethylsiloxane copolymer, trimethylsiloxy group end-capped methyloctenylsiloxane / dimethylsiloxane copolymer, dimethylpentenylsiloxy group End-blocked methylphenyl siloxane / dimethyl siloxane copolymer, silanol group end-blocked methyl pentenyl siloxane / dimethyl siloxane copolymer, dimethyl hexenyl siloxy group end-blocked hexenyl methyl siloxane / dimethyl siloxane copolymer, dimethyl hexenyl siloxy group end-blocked diphenyl siloxane Examples include, but are not limited to, dimethyl siloxane copolymers.

The hydrogen polysiloxane containing two or more silicon-bonded hydrogen atoms in one molecule of the component B) in the present invention serves as a crosslinking agent for the component A). The crosslinking is based on a hydrosilylation reaction, and specifically, an addition reaction of the Si-H group of the component B) to the unsaturated bond of the component A) occurs.

Specific examples of this component include, for example, trimethylsiloxy group end-blocked methyloctylsiloxane / dimethylsiloxane / hydrogenmethylmethylsiloxane copolymer, trimethylsiloxy group endblocked hydrogenenemethylsiloxane / octylhydrodienesiloxane copolymer. , Trimethylsiloxy end-capped dimethyl siloxane / octyl hydrogen diene siloxane copolymer,
Octyl group-containing organohydrogenpolysiloxanes such as trimethylsiloxy group-endblocked methyloctylsiloxane / hydrogenmethylsiloxane copolymers; trimethylsiloxy group-endblocked dimethylsiloxane / butylhydrogensiloxane copolymers, trimethylsiloxy group-endblocked butylmethyl Siloxane / hydrogen methyl siloxane copolymer, trimethylsiloxy group end-capped dimethyl siloxane / butyl methyl siloxane /
Examples thereof include butyl group-containing organopolysiloxanes such as hydrogendiene methyl siloxane copolymers, but are not limited thereto.

The amount of this component blended is 0.1 to 40 parts by weight, preferably 0.5 to 20 parts by weight, relative to 100 parts by weight of component A).
By weight, more preferably 1 to 10 parts by weight. When the amount of component B) is less than 0.1 parts by weight, the amount of component B is 4
In all cases where the amount is more than 0 parts by weight, the crosslinking of the component A becomes insufficient, the strength of the release layer of the release film decreases, and as a result, the substrate adhesion and solvent resistance deteriorate. Further, when the amount is more than 40 parts, the peeling ability tends to decrease.

The platinum group metal catalyst of component C) in the present invention is a catalyst for accelerating the hydrosilylation reaction (addition reaction of Si-H group to unsaturated bond) between component A) and component B). There are known hydrosilylation (addition reaction) catalysts. Examples of such platinum group metal-based catalysts include platinum-based, palladium-based, and rhodium-based catalysts, and of these, platinum-based catalysts are particularly preferable. Examples of such platinum catalysts include chloroplatinic acid, alcoholic solutions of chloroplatinic acid and aldehyde solutions, and complexes of chloroplatinic acid with various olefins or vinylsiloxanes.

The amount of the platinum group metal-based catalyst added is a catalytic amount, but from the viewpoint of obtaining a good hardened layer and economically, the amount of the platinum group metal is 1 to 1, based on 100 parts by weight of the component A). It is preferably in the range of 000 ppm, more preferably 10 to 300 ppm.

The silane compound of component D) in the present invention is a compound represented by the following chemical formula [Chemical formula 1], and functions as a curing retarder to improve the storage stability of the polysiloxane coating composition of the present invention. When the base material has a hydroxyl group or the like, it has a role of improving the adhesion between the release layer and the base material by fixing the release layer to the base material by a covalent bond.

[0038]

[Chemical 11] (R ₁ is an alkylene group having 1 to 10 carbon atoms, R 2, R ₃
Represents an alkyl group having 1 to 4 carbon atoms. ) As a mechanism by which the component (D) enhances the storage stability of the coating composition, the ketoxime site is preferentially coordinated with the platinum group metal-based catalyst to prevent the unsaturated group of the component (A) from being coordinated with the catalyst. Presumed to be present. In addition, as a base material adhesion improving mechanism, when a base material having a hydroxyl group on the surface such as polyester is used, the vinyl portion of the component D) reacts with the component B in a hydrosilylation reaction, and the dialkylketoxime portion is After the elimination, the component D) reacts with the hydroxyl group of the base material to obtain —Si—O—
It is presumed that by forming the C-bond, the substrate and the polysiloxane of the release layer are covalently bonded.

Specific examples of the component D) include, for example, vinyltris (dimethylketoxime) silane, vinyltris (ethylmethylketoxime) silane, vinyltris (diethylketoxime) silane, vinyltris (ethylpropylketoxime) silane, vinyltris ( Butylethylketoxime) silane, propenyltris (ethylmethylketoxime) silane, butenyltris (ethylmethylketoxime) silane, hexenyltris (dimethylketoxime) silane, hexenyltris (ethylmethylketoxime) silane, and the like. It is not limited to.

The amount of this component used is such that a practical pot life is obtained, and it may be an amount sufficient to sufficiently enhance the adhesiveness between the base material and the release layer, but the reaction suppressing effect varies depending on its molecular structure. The amount is not particularly limited and may be any amount, but is preferably 0.1 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, still more preferably 1 to 5 parts by weight, relative to 100 parts by weight of the component A). Good parts by weight. When the amount added is less than 0.1 parts by weight, the effect of improving the adhesiveness between the release layer and the base material tends to be small, and when it is more than 20 parts by weight, the reaction suppressing effect becomes too strong and the reaction rate Becomes extremely slow, and it becomes difficult to cure under normal conditions.

The component E) in the present invention is a non-polar organic solvent capable of dissolving the release layer component, and adjusts the viscosity of the coating material to optimize the coating property, and roughens the surface of the base material to form the base material. It has a role of improving the adhesiveness of the release layer.

Specific examples of E) include toluene, xylene, carbon tetrachloride, 1,1,1 trichloroethane, diethyl ether, petroleum hydrocarbons (n-hexane, n-heptane, n-nonane, etc.), trichloroethane. , Perchloroethane, etc. are exemplified.

The component E) is usually added in an amount of 100 to 10,000 parts by weight per 100 parts by weight of the component A). 100
If the amount is more than 00 parts by weight, the viscosity of the coating agent may be too low and the coatability may be deteriorated. Further, from the economical viewpoint, it is preferable to reduce the amount of solvent used. If the amount is less than 100 parts by weight, the viscosity of the coating agent becomes too high and the coatability deteriorates, which is not preferable.

The component F) in the present invention has the following chemical formula
An alcohol represented by [Chemical formula 2] and / or an ester represented by a chemical formula [Chemical formula 3], which lowers the insulating property of the coating agent to neutralize the charge on the surface of the film that is frictionally charged, It has the role of improving coatability and leveling characteristics, and making it possible to form a very thin uniform release layer on the film surface.

[0045]

[Chemical 12] (R ₄ represents an alkyl group having 2 to 5 carbon atoms.)

[0046]

[Chemical 13] (R ₅ represents an alkyl group having 1 to 4 carbon atoms, and R ₆ represents an alkyl group having 1 to 5 carbon atoms.) Specific examples of the compound represented by the chemical formula [Formula 2] include ethanol,
n-propyl alcohol, i-propyl alcohol, n
-Butyl alcohol, sec-butyl alcohol, t-
Examples thereof include butyl alcohol, n-pentanol, n-hexyl alcohol, and n-octyl alcohol, and examples of the compound of formula 3 include ethyl acetate, propyl acetate, butyl acetate, ethyl propionate, and ethyl butanoate. It is not limited to these. The component (F) is usually 5 to 70 parts by weight with respect to 100 parts by weight of the component E,
Preferably 10 to 50 parts by weight, more preferably 10 to 3
0 parts by weight are added. If the amount is more than 70 parts by weight, the polarity of the solvent constituting the coating agent becomes too high, and the solubility of the polysiloxane in the solvent becomes low, so that the usable polysiloxane is limited, and the polysiloxane is not used in the coating process. It may precipitate and the coatability may deteriorate.
If the amount is less than 5 parts by weight, it becomes difficult to obtain the effect of addition.

The polysiloxane coating composition of the present invention can be obtained by mixing the above-mentioned components A) to F) in predetermined amounts, but it is possible to add other components in addition to the above components. .

For example, for the purpose of controlling the blocking resistance and slipperiness of the release film, silicone resin particles, acrylic resin particles, polystyrene resin particles, melamine resin particles, silica, alumina, titania, calcium oxide, calcium carbonate, etc. For the purpose of optimizing the catalytic activity of various organic or inorganic fine particles and platinum group metal-based catalysts, various organic nitrogen compounds, organophosphorus compounds, acetylene compounds, oxime compounds, organic chloro compounds, etc. A silicone resin or a diorganopolysiloxane which does not have a hydrogen atom bonded to a silicon atom or a vinyl group may be added for the purpose of controlling the temperature. In addition, the addition amount of the optional component can be a normal amount as long as the effect of the present invention is not impaired.

In preparing the polysiloxane-based coating composition of the present invention, after the components A), B), E), F) and optional components are uniformly mixed in advance, the component D) is added and mixed uniformly. Finally, it is preferable to add the component C) which is a catalyst. Each component may be used alone or in combination of two or more kinds.

The polysiloxane-based coating agent thus prepared can be applied to a plastic film substrate and then heat-cured by a conventional method. The substrate having a cured film formed by the coating composition of the present invention is preferably used as a release film or the like. The release film that can be produced using the coating material of the present invention will be described below.

The plastic film, which is the base material in the release film of the present invention, is an unstretched film obtained by melting a raw material resin into a film as it is, and a uniaxial film obtained by stretching the unstretched film in either the longitudinal direction or the width direction. Either a stretched film or a biaxially stretched film that has been stretched in both the longitudinal and width directions may be used, but a thermoplastic film that is melt extrudable and crystallographically oriented by biaxial stretching is preferable. Biaxially oriented means unstretched, that is, the thermoplastic film before crystal orientation is completed is stretched by 2.5 to 5.0 times in each of the longitudinal direction and the width direction, and then the crystal orientation is completed by heat treatment. And shows a biaxially oriented pattern in wide-angle X-ray diffraction. When the thermoplastic film is biaxially oriented, dimensional stability of the laminated film, particularly dimensional stability under high temperature and high humidity, mechanical strength, flatness and the like are improved, which is preferable.

Specific examples of such a film base material include films of polyester, polyolefin, polyamide, polyphenyl sulfide and the like. In particular, the polyester film has transparency, dimensional stability, mechanical properties, and lamination in the present invention. It is preferable in terms of adhesiveness to the release layer. The preferred polyester is not particularly limited, but may be polyethylene terephthalate, polyethylene naphthalate, polypropylene terephthalate, polybutylene terephthalate, polypropylene naphthalate, or the like, and may be a mixture of two or more thereof. Further, these may be copolymerized with other dicarboxylic acid components or diol components, but in this case, in the film in which the crystal orientation is completed, the crystallinity is 25% or more, preferably 30% or more, It is more preferably 35% or more. It may also be a composite film having two or more layers of an inner layer and a surface layer. For example, substantially no particles in the inner layer portion, a composite film provided with a layer containing particles in the surface layer portion, having a coarse particle in the inner layer portion, a laminate film containing fine particles in the surface layer portion Examples include a composite film in which the inner layer portion is a layer containing fine bubbles and the surface layer portion is substantially free of bubbles. Further, in the composite film, the inner layer portion and the surface layer portion may be different polymers or the same polymer. Crystallinity is 25
If it is less than%, the dimensional stability and mechanical strength tend to be insufficient. When the above polyester is used, its intrinsic viscosity (measured in o-chlorophenol at 25 ° C.) is preferably 0.4 to 1.2 dl / g, and 0.5 to
More preferably, it is 0.8 dl / g.

The base film of the present invention may contain various additives, resin compositions, cross-linking agents and the like within a range that does not impair the effects of the present invention. For example, antioxidants, heat stabilizers, UV absorbers, organic and inorganic particles, pigments, dyes, antistatic agents, nucleating agents, acrylic resins, polyester resins, urethane resins, polyolefin resins, polycarbonate resins, alkyd resins, epoxy resins. , Urea resin, phenol resin, silicone resin, rubber resin, wax composition, melamine crosslinking agent, oxazoline crosslinking agent, methylolated, alkylolated urea crosslinking agent, acrylamide, polyamide, epoxy resin, isocyanate compound , Aziridine compounds, various silane coupling agents,
Examples thereof include various titanate coupling agents.

Among these, when inorganic particles such as silica, colloidal silica, alumina, alumina sol, kaolin, talc, mica, calcium carbonate, barium sulfate, carbon black, zeolite, titanium oxide and fine metal powder are added. It is particularly preferable because it improves slipperiness and scratch resistance. The average particle size of the inorganic particles is 0.
005 to 5 μm, preferably about 0.05 to 1 μm. The addition amount is 0.05 to 20 parts by weight, preferably 0.1 to 10 parts by weight.

Next, the method for producing the release film of the present invention will be described.

The release film of the present invention can be produced by applying a polysiloxane coating agent to various films as described above by a conventional method. The productivity of the film, the release layer and the substrate are In consideration of adhesion, film strength, dimensional stability of the film, etc., a coating method is applied to a uniaxially stretched film that is uniaxially stretched in the longitudinal direction, stretched in the width direction, and heat treated (in-line coating method).
Is preferred.

The surface of the base material on which the release layer is formed before applying the coating agent is subjected to various treatments such as air, nitrogen gas, carbon dioxide gas, etc. in order to improve the adhesion to the release layer. Corona discharge treatment, chemical treatment, physical etching treatment, anchor treatment and the like may be performed in any atmosphere. Of these, corona treatment in air is a method that can effectively introduce hydroxyl groups on the surface of the plastic film,
This is a preferred method because the adhesion of the release layer to the substrate can be greatly improved by the reaction with the silane coupling agent which is the component D) in the polysiloxane coating composition of the present invention.

As means for applying the polysiloxane coating composition of the present invention, various coating methods such as reverse coating method,
A gravure coating method, a rod coating method, a bar coating method, a die coating method, a spray coating method, a kiss coating method, a reverse kiss coating method, an air knife coating method, a curtain coating method, an impregnation method and the like can be used. Each method has its own characteristics, and the coating method may be appropriately selected depending on the required characteristics of the release film, the intended use, the characteristics of the coating agent, and the like.

The thickness of the release layer of the release film of the present invention is preferably about 0.01 to 0.3 μm, more preferably 0.05 to 0.2 μm, still more preferably 0.05 to 0.
1 μm is desirable. Since the coating agent of the present invention has excellent coatability on a plastic film substrate, it is possible to form a uniform coating film even when the release layer is very thin, and a dry release thickness of 0.1 μm or less. Even when the layer is coated, a release film having extremely good characteristics can be obtained. In particular, when the release layer is thinned, there is a tendency that the adhesiveness to the substrate, the peeling force, and the transferability to the back surface are deteriorated and become nonuniform, but these properties are improved by using the coating agent of the present invention. Can be made. It is considered that reducing the thickness of the coating film is one of the characteristics strongly required for the release film in consideration of cost reduction of the release film and recycling of the release film.

The thickness of the base film in the release film of the present invention is not particularly limited, but is, for example, 0.5 to 500.
It can be appropriately selected depending on the application in the range of about μm.

A preferable production method for obtaining such a film will be exemplified below, but the present invention is not necessarily limited to this.

After the polyester resin is melt extruded to form a film, it is uniaxially stretched in the longitudinal direction to obtain a uniaxially stretched film. A polysiloxane coating agent is applied to the film before completion of the crystal orientation, and the solvent is stretched together with the substrate before the solvent is dried, and then the solvent is evaporated and heat-fixed to complete the crystal orientation of the substrate. For example, when the base material is a polyester resin, the preheating and stretching temperatures are 85 to 150 ° C,
The heat treatment temperature is preferably 200 to 250 ° C. (Method of measuring characteristics and method of evaluating effects) The method of measuring characteristics and the method of evaluating effects in the present invention are as follows. (1) Thickness of coating layer A cross section of the release layer of the release film was observed using a transmission electron microscope HU-12 type manufactured by Hitachi Ltd. or a transmission electron microscope having a function equivalent to this, and a photograph thereof The thickness of the coating layer is calculated from The thickness is measured as an average value of 30 measurement points. (2) Peeling stress A rubber roller (line pressure of 1 kg / cm) was applied to the release layer surface of the release film so that the acrylic adhesive tape having a width of 19 mm (Knit-polyester tape 31B manufactured by Nitto Denko Corporation) was 200 mm in length. Crimp with. The stress when peeling this adhesive tape at a pulling speed of 300 mm / min and a peeling angle of 180 degrees is determined. The measurement takes the average value of 10-point measurement. (3) Solvent resistance The release layer surface was rubbed 10 times with a cotton swab containing the following organic solvent to remove the release layer from the acrylic adhesive tape having a width of 19 mm (Knit-polyester tape 31 manufactured by Nitto Denko Corporation).
Paste B) and evaluate according to the following criteria. (Toluene, ethyl acetate, ethanol, 2-butanone) O: The adhesive tape is lightly peeled off.

X: Resistance is felt when the adhesive tape is peeled off. (4) Overlay a polyethylene terephthalate film having a thickness of 38 μm on the coated surface of the rear transferable release film sample, and
Crimping is carried out at 0 ° C. for 20 hours under a load of 100 g / cm ² .
Then, after standing for 3 hours at 23 ° C. and 65% RH, an oil-based magic ink is applied to the surface of the film which is in contact with the release layer, and the repulsion of the ink is evaluated according to the following criteria.

◯: The ink is not repelled at all.

X: Repels ink (x when ink is repelled even a little). (5) Adhesion (lab-off) The release layer surface is rubbed strongly 5 times with a fingertip to visually confirm the release property of the release layer and evaluate according to the following criteria.

◯: Not dropped.

X: Missing (6) Life of coating material The time (hr) until curing (gelation) when the coating material is stored at 50 ° C is measured.

[0068]

EXAMPLES The present invention will now be described based on examples. <Preparation of release layer-forming polysiloxane coating> Polysiloxane polymer (A) component), hydrogen polysiloxane (B) component), chloroplatinic acid catalyst (C) component) (containing 5000 ppm of platinum metal component), A saturated group-containing silane compound (D) component), a non-polar solvent (E) component), and an organic polar solvent (F) component) were mixed in the composition shown in Table 1 to prepare a polysiloxane coating agent. The order of mixing is A), B),
After the components E) and F) were mixed to make a uniform state, the component D) was added to make a uniform state again, and finally the component C) was added.

[0069]

[Table 1] The numbers in the table indicate the component amount ratio (parts by weight) of each component. A) component: Polymer A; both-end vinyl group-blocked polydimethylsiloxane (Mw = 50,000) Polymer B; both-end vinyl group-blocked polydimethylsiloxane (Mw = 250,000) Polymer C; both-end vinyl group-blocked polydimethylsiloxane (Mw =) 500,000) Polymer D; Polydimethylsiloxane (Mw = 5,000) blocked with vinyl groups at both ends B) Component: Crosslinking agent A; SiH group-containing polysiloxane (a in the following chemical formula
= 6, b = 4) Crosslinking agent B: SiH group-containing polysiloxane (a in the following chemical formula:
= 3, b = 7) Crosslinking agent C; SiH group-containing polysiloxane (a in the following chemical formula:
= 7, b = 3)

[0070]

[Chemical 14] C) component: chloroplatinic acid-based catalyst (containing 5000 ppm of platinum metal component) D) component: compound A; vinyl tris (ethylmethyl ketoxime)
Silane compound B; vinyltris (dimethylketoxime) silane compound C; vinyltris (diethylketoxime) silane E) component: "Isopar" H (manufactured by Exxon Chemical Co., Ltd.) F) component: IPA (isopropanol) F) component Numbers indicate parts by weight relative to 100 parts by weight of E component. (Examples 1 to 19) Polyethylene terephthalate (hereinafter PET) containing 0.015% by weight of colloidal silica having an average particle size of 0.4 μm and 0.005% by weight of colloidal silica having an average particle size of 1.5 μm (intrinsic viscosity). 0.63dl
/ G) After sufficiently vacuum-drying the chips at 180 ° C, the chips are supplied to an extruder, melted at 285 ° C, extruded into a sheet form from a T-shaped die, and subjected to a static electricity cast method at a surface temperature of 20 ° C. It was wound around a mirror surface cast drum and cooled and solidified. This unstretched sheet was stretched 3.5 times in the longitudinal direction with a roll group heated to 95 ° C. to obtain a uniaxially stretched film. Coating materials 1-3, 5-8 shown in Table 1 on one side of this film,
11 to 14, 17, and 18 were applied by a bar coating method so that the final laminated thickness was 0.1 μm. The coated film was guided to a preheating zone of 100 ° C. while gripping both ends of the film with clips, and subsequently stretched 3.5 times in the width direction in a heating zone of 110 ° C. Further, heat treatment was continuously performed for 5 seconds with a heat treatment sawne at 230 ° C. to complete the crystal orientation of the base film. This laminated film had a thickness of 40 μm and a laminated thickness of 0.1 μm and was excellent in transparency and flatness. The characteristics of the obtained release film are shown in Table 2.
All of these release films shown in Examples 1 to 22 exhibited sufficiently light peeling stress, good solvent resistance, rear surface transferability, and adhesion to the base film. Further, all the coating materials used here exhibited a good coating material life. However, F)
Examples 17 to 20 using the coating material 20 having a small amount of components
Regarding No. 19, when the coating film was thinned, the peeling force was slightly uneven and the peeling force tended to be slightly higher.

[0071]

[Table 2] (Example 23) A coating film 18 having a composition shown in Table 1 was used for a biaxially oriented polyester film ("Lumirror" T60 manufactured by Toray Industries, Inc.) having a thickness of 50 µm, and the thickness after drying was 0.1 µm.
The coating film was dried and cured by heating in a hot air oven at 140 ° C. for 3 minutes. The properties of the obtained release film are also shown in Table 2. This release film exhibited sufficiently light peel stress, good solvent resistance, rear surface transferability, and adhesion to the base film. Example 24 A PET (intrinsic viscosity 0.63 dl / g) chip containing 0.015% by weight of colloidal silica having an average particle size of 0.4 μm and 0.005% by weight of colloidal silica having an average particle size of 1.5 μm was used. After fully vacuum-dried at 180 ° C, supply to an extruder, melt at 285 ° C, extruded into a sheet from a T-shaped die, and wrapped around a mirror-cast cast drum with a surface temperature of 20 ° C using the electrostatic applied casting method. It solidified by cooling. This unstretched sheet was stretched 3.5 times in the longitudinal direction with a roll group heated to 95 ° C. to obtain a uniaxially stretched film. After performing corona treatment on one surface of this film in air, the coating material 18 shown in Table 1 was applied to the corona-treated surface by a bar coating method so that the final laminated thickness was 0.1 μm. While holding both ends of the coated film with clips, guide it to the preheating zone of 100 ° C, and continue to 110 ° C.
Was stretched 3.5 times in the width direction in the heating zone. Further, heat treatment was continuously performed for 5 seconds in a heat treatment zone of 230 ° C. to complete the crystal orientation of the base film. This laminated film had a thickness of 40 μm and a laminated thickness of 0.1 μm and was excellent in transparency and flatness. The properties of the obtained release film are also shown in Table 2. All of the release films exhibited sufficiently light peel stress, good solvent resistance, rear surface transferability, and adhesion to the base film. (Comparative Examples 1 to 7) Coating agents 4, 9, 10, and 1 shown in Table 1
Using 5, 16, 19, and 22, a release film was trial-produced by the same method as in Examples 1 to 17. This laminated film had a thickness of 40 μm and a laminated thickness of 0.1 μm and was excellent in transparency and flatness. The properties of the obtained release film are shown in Table 3.

Comparative Example 1 using a low molecular weight polysiloxane as the component A) was poor in solvent resistance, rear surface migration and adhesion to the substrate. Further, also in Comparative Examples 2 and 3 in which the amount of the component B) as the cross-linking agent was inappropriate, the solvent resistance, back migration and adhesion were poor. In Comparative Example 4 in which the amount of the silane coupling agent as the component D) is too small, the coating agent life, solvent resistance and adhesion are poor, and in Comparative Example 5 in which the amount is too large, solvent release is caused by insufficient curing of the release layer. , The rear surface transferability and the adhesion were poor. Although the coating agent 19 is a coating agent containing no F component, when the coating film thickness was sufficiently thick (0.5 micron) as in Example 14, good peeling force was exhibited,
When the coating film thickness was as thin as 0.1 μm as in Comparative Example 6, the peeling force was slightly uneven and the value was high.
In Comparative Example 7, which contains an excess of butyl acetate as the component F),
A visually ununiform coating film was formed, and the peeling force was also uneven.

[0073]

[Table 3]

[0074]

EFFECT OF THE INVENTION A polysiloxane-containing coating agent which is less deteriorated with time and is excellent in coating property on a plastic film substrate,
Also, it is possible to provide a release film having an extremely thin release layer which is excellent in peeling force, solvent resistance, back surface migration and substrate adhesion.

   ─────────────────────────────────────────────────── ─── Continued front page    F term (reference) 4F100 AH06B AK01A AK42A AK42K                       AK52B AK52H BA02 EH462                       EJ373 EJ423 EJ55A EJ553                       GB90 JA07B JA20A JB01                       JK06 JL00 YY00B                 4J038 DL042 DL082 DL101 JA19                       JA55 JC38 KA04 KA06 MA14                       NA10 PB04 PC08

Claims (7)

[Claims] 1. A) 100 parts by weight of a polysiloxane having at least two unsaturated groups in one molecule, and B) a hydrogen polysiloxane having at least two hydrogen atoms directly bonded to silicon atoms in one molecule. 1 to 40 parts by weight,
C) a catalytic amount of a platinum group metal-based catalyst, D) the following chemical formula:
0.1 to 20 parts by weight of the compound represented by E), and E) a nonpolar organic solvent capable of dissolving polysiloxane A) 100 to 1000
0 parts by weight and F) alcohols represented by the following chemical formula [Chemical formula 2] and / or esters represented by the following chemical formula [Chemical formula 3] are used in an amount of 5 to 70 parts by weight based on 100 parts by weight of the component E).
A polysiloxane-based coating agent, characterized by comprising parts by weight. [Chemical 1] (R ₁ is an alkylene group having 1 to 10 carbon atoms, R ₂ , R ₃
Represents an alkyl group having 1 to 4 carbon atoms. ) [Chemical 2] (R ₄ represents an alkyl group having 2 to 5 carbon atoms.) (R ₅ represents an alkyl group having 1 to 4 carbon atoms, and R ₆ represents an alkyl group having 1 to 5 carbon atoms.) 2. A weight average molecular weight Mw of polysiloxane A).
Is 1,000,000 to 1,000,000, and the polysiloxane-based coating composition according to claim 1. 3. A release layer is provided by applying a coating agent containing the polysiloxane coating agent according to claim 1 on at least one side of a plastic film, drying and then heat-treating the coating agent. Release film. 4. The release film according to claim 3, wherein the plastic film is a polyethylene terephthalate film or a polyethylene-2,6-naphthalate film. 5. When providing a release layer, a release layer forming coating agent is applied to at least one surface of a plastic film before completion of crystal orientation, and then stretched and heat-treated in at least one direction to complete crystal orientation. The release film according to claim 3 or 4, which is obtained by 6. The release film according to claim 5, wherein the plastic film before the crystal orientation is completed is subjected to corona treatment, and then the release layer forming coating agent is applied. 7. The release film according to claim 5, wherein the release layer has a thickness of 0.01 to 0.3 μm.