JP2016180039A - Oil-in-water type silicone emulsion composition for removal film coating and removal film using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a silicone emulsion composition for removal film coating capable of reducing the size and number of projections on a removal film surface and a removal film using the same.SOLUTION: The oil-in-water type silicone emulsion composition for removal film coating contains oil-in-water type silicone emulsion (I) and (II), the (I) contains components (A) to (E):(A) diorganopolysiloxane containing 2 or more alkenyl groups binding to a silicon atom in a molecule, (B) a platinum-based catalyst, (C) alkenyl dicarboxylate ester, (D) a nonionic surfactant and (E) water, and the (II) contains components (F) to (H):(F) organo hydrogen polysiloxane containing 2 or more hydrogen atoms binding to a silicon atom in a molecule, (G) the nonionic surfactant and (H) water.SELECTED DRAWING: None

Description

  The present invention relates to an addition-reaction type oil-in-water silicone emulsion composition for coating a release film that imparts high smoothness to the surface of the release film, and a release film using the same.

It is known that a coating composition containing silicone as a main component can impart performances such as peeling properties, releasability, and water repellency to a substrate surface by coating on the substrate surface. For example, in protective films and release films used in the manufacture of electronic components such as adhesives and ceramic capacitors, the silicone film is formed on the surface of the plastic film that is the base material, thereby imparting peelability to the plastic film. Things have been done.
Further, in recent years, when a release film is used when manufacturing a ceramic capacitor from a ceramic green sheet, it has been found that the protrusion on the surface of the release film affects the performance of the obtained ceramic capacitor. This effect is increasing with the miniaturization of electronic components, and sufficient smoothness of the surface of the release film is required.

  When a release film is used for a thin film ceramic green sheet, a pinhole may be formed on the release surface due to a strong protrusion of a release film roll, or a small protrusion made of a film additive or the like may cause island-like leakage. May cause serious defects in peelability. On the other hand, Patent Document 1 does not impair the function of the coating agent by winding a film having a coated surface with a low coefficient of friction that is rich in slidability into a roll with a controlled appropriate winding hardness. The release film that can be exhibited in the above is described, and the problem of peelability of the release film is solved by adjusting the winding method.

In Patent Document 2, a release layer containing a curable silicone resin as a main component is provided on one side of a polyester film, and an antistatic layer is provided on the other side so that the silicone resin attached to the antistatic layer side surface is attached. The method of making the kimono 50 pieces / 25 mm ² or less and smoothing the surface solves the problem of peelability of the release film.
Further, in Patent Document 3, when forming a thin film green sheet, slurry repelling or pinholes occur when ceramic slurry is applied to the release film, or when the green sheet is peeled off from the release film, Problems such as breakage and the like are solved by the film manufacturing method.

JP 2007-186594 A JP 2003-145485 A JP 2004-195750 A

In the inventions described in the above documents (Patent Documents 1, 2, and 3), the surface smoothness of the release film is improved by the production process of the release film and a method of newly providing a release layer. The problem of the occurrence of protrusions and aggregates on the surface of the release film that is the cause has not been solved. For this reason, a silicone release coating agent that can reduce protrusions and aggregates has been demanded.
On the other hand, generally, a method is known in which a release coating silicone composition is dissolved in an organic solvent and applied to the film surface. However, since this method uses an organic solvent, there are problems of safety to the human body, environmental burden, and high cost. For this reason, in recent years, a water-based silicone release coating agent has been used, and in particular, a silicone emulsion composition for release film coating, which is a water-based silicone composition, has been demanded.

  The present invention has been made in view of the above circumstances, and a release film coating silicone emulsion composition capable of reducing the size of protrusions on the surface of a release film and reducing the number of protrusions, and a release film using the same. The purpose is to provide.

  As a result of intensive studies, the present inventors have found that when a dicarboxylic acid alkenyl ester is used in place of an alkenyl alcohol in which a conventional reaction proceeds smoothly as a reaction inhibitor for a silicone emulsion for release coating, the silicone emulsion is converted into a film. It has been found that it is possible to suppress the occurrence of protrusions that occur when coating on a substrate. Further, the present inventors have found that by reducing the amount of catalyst in the release coating silicone emulsion, the size of the protrusions on the surface of the release film can be reduced and the number of protrusions can be reduced. Furthermore, the present inventors have found that the size of the protrusions on the surface of the release film can be reduced and the number of protrusions can be reduced by reducing the content of diorganopolysiloxane having a high vinyl content. The present inventors have also found that the amount of each of the reaction inhibitor and the catalyst added can be reduced by adjusting the type of the reaction inhibitor and the catalyst amount of the release coating silicone emulsion. The present invention has been made based on these findings.

That is, the oil-in-water silicone emulsion composition for release film coating of the present invention is an oil-in-water silicone emulsion composition for release film coating containing an oil-in-water silicone emulsion (I) and an oil-in-water silicone emulsion (II). ,
The oil-in-water silicone emulsion (I) has the following components (A) to (E): (A) The average composition formula is represented by the general formula (1), and 2 alkenyl groups bonded to silicon atoms are contained in one molecule. Diorganopolysiloxane containing 20 to 60% by mass,
R ¹ _a R ² _b SiO _{(4-ab) / 2} (1)
[Wherein R ¹ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated group, R ² is an alkenyl group, a is 1 to 3, b is 0.1 to 2, a + b is 1 to 3 It is. ],
(B) The amount of the white metal catalyst is 1 to 500 ppm based on the weight of the diorganopolysiloxane (A), (C) 0.01 to 3% by mass of a dicarboxylic acid alkenyl ester, D) 1 to 10% by weight of a nonionic surfactant and (E) 30 to 80% by weight of water, and the oil-in-water silicone emulsion (II) comprises the following components (F) to (H): (F ) Organohydrogenpolysiloxane having an average composition formula represented by the general formula (2) and containing two or more hydrogen atoms bonded to silicon atoms in one molecule.
R ³ _c H _d SiO _{(4-cd) / 2} (2)
[Wherein R ³ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated group, c is 1 to 3, d is 0.01 to 2, and c + d is 1 to 3]
(G) 1 to 10% by mass of a nonionic surfactant and (H) 20 to 80% by mass of water are contained.

  In the oil-in-water silicone emulsion composition for release film coating, the dicarboxylic acid alkenyl ester (C) of the oil-in-water silicone emulsion (I) is preferably diallyl maleate.

  In the oil-in-water silicone emulsion composition for release film coating, the film constituting the release film is preferably a plastic film.

  In the oil-in-water silicone emulsion composition for coating a release film, the oil-in-water silicone emulsion (I) contains a white metal catalyst (B) and a white metal metal based on the weight of the diorganopolysiloxane (A). Is preferably contained in an amount of 5 to 200 ppm.

  The release film of the present invention is obtained by applying the oil-in-water silicone emulsion composition for coating a release film on the surface of the film.

  According to the oil-in-water silicone emulsion composition for coating of the present invention, by reducing the addition amount of diorganopolysiloxane having a high alkenyl group content, the formation of protrusions and aggregates caused by a high crosslinking density can be achieved. It can be suppressed.

  Further, according to the oil-in-water silicone emulsion composition for coating of the present invention, the reaction start can be suppressed by reducing the amount of the catalyst added or by using a dicarboxylic acid alkenyl ester-based reaction inhibitor. The generation of agglomerates generated in step (1) can be suppressed, local crosslinking due to abrupt reaction start at the time of heat curing is less likely to occur, and the amount of protrusions and aggregates on the coating film surface can be reduced.

  According to the oil-in-water silicone emulsion composition for coating of the present invention, the number of protrusions on the silicone coating film surface of the release film can be reduced and the size of the protrusions can be reduced, and the smoothness of the release film coated silicone coating film surface. Can keep.

  Moreover, according to the oil-in-water silicone emulsion composition for coating of the present invention, the pot life of the coating liquid during coating can be extended, and workability can be improved.

  Furthermore, according to the oil-in-water silicone emulsion composition for coating of the present invention, the coloration seen in emulsions using alkenyl alcohol-based reaction inhibitors can be suppressed, and the transparency of the film can be maintained.

Details of the oil-in-water silicone emulsion composition for release film coating according to the present invention will be described below.
The oil-in-water silicone emulsion composition for coating a release film of the present invention contains an oil-in-water silicone emulsion (I) and an oil-in-water silicone emulsion (II).

[Oil-in-water silicone emulsion (I)]
The oil-in-water silicone emulsion (I) contains the following components (A), (B), (C), (D) and (E).

(Ingredient (A))
The component (A) is a diorganopolysiloxane having an average composition formula represented by the general formula (1) and containing two or more alkenyl groups bonded to a silicon atom in one molecule. Hereinafter, the component (A) diorganopolysiloxane is also referred to as alkenylorganopolysiloxane.
R ¹ _a R ² _b SiO _{(4-ab) / 2} (1)
In the formula (1), R ¹ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated group, R ² is an alkenyl group, a is 1 to 3, b is 0.1 to 2, and a + b is 1-3.
In formula (1), R ¹ preferably has 1 to 18 carbon atoms. R ¹ is preferably SiC-bonded. Furthermore, R ¹ is preferably a substituted or unsubstituted hydrocarbon group having no aliphatic carbon-carbon multiple bond.
In formula (1), R ² preferably has 1 to 18 carbon atoms. R ² is preferably a monovalent hydrocarbon group having an aliphatic carbon-carbon multiple bond.
In Formula (1), a is 1-3, b is 0.1-2, a + b is 1-3.
The alkenylorganopolysiloxane represented by the general formula (1) preferably has an average of at least 2 R ² per molecule.

  The alkenylorganopolysiloxane preferably has a viscosity at 25 ° C. of 5 to 100,000 mPa · s.

  As an alkenyl group in a component (A), C2-C8 alkenyl groups, such as a vinyl group, an allyl group, 1-butenyl group, 1-hexenyl group, can be illustrated, for example, Preferably a vinyl group , An allyl group, and particularly preferably a vinyl group. These alkenyl groups react with the component (F) described later to form a network structure. There are an average of about 2 alkenyl groups, preferably 1.6 to 2.2 in the molecule of component (A). Such an alkenyl group may be bonded to a silicon atom at the end of the molecular chain, or may be bonded to a silicon atom in the middle of the molecular chain. From the viewpoint of the curing reaction rate, an alkenyl group-containing polyorganosiloxane in which an alkenyl group is bonded only to the silicon atom at the molecular chain terminal is preferred.

  The other organic group bonded to the silicon atom in component (A) is preferably a substituted or unsubstituted monovalent hydrocarbon group not containing an aliphatic unsaturated bond having 1 to 12 carbon atoms. Specific examples of the other organic groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, neopentyl group, hexyl group, 2-ethylhexyl group, and heptyl group. Alkyl groups such as octyl group, nonyl group, decyl group and dodecyl group; cycloalkyl groups such as cyclopentyl group, cyclohexyl group and cycloheptyl group; aryl groups such as phenyl group, tolyl group, xylyl group, biphenyl group and naphthyl group An aralkyl group such as a benzyl group, a phenylethyl group, a phenylpropyl group, or a methylbenzyl group; a chloromethyl group in which some or all of the hydrogen atoms in these hydrocarbon groups are substituted by a halogen atom, a cyano group, or the like; -Bromoethyl group, 3,3,3-trifluoropropyl group, 3-chloropropyl group, chloro Eniru group, dibromophenyl group, tetra-chlorophenyl group, difluorophenyl group, beta-cyanoethyl group, .gamma.-cyanopropyl group, and substituted hydrocarbon groups such as beta-cyanopropyl group. Particularly preferred organic groups are a methyl group and a phenyl group.

The alkenyl group-containing polyorganosiloxane (A) may be linear or branched, or a mixture thereof. This alkenyl group-containing polyorganosiloxane is produced by methods known to those skilled in the art.
In order to use the oil-in-water type silicone emulsion composition for release film coating of the present invention for a release coating agent or the like, the composition needs to have appropriate release properties. Appropriate peelability is that the viscosity of the alkenylorganopolysiloxane (A) at 25 ° C. is preferably in the range of 5 to 2000000 mPa · s, more preferably 50 to 1000000 mPa · s, and particularly preferably 100 to 50000 mPa · s. It is given by. Furthermore, by reducing the content of diorganopolysiloxane having a high alkenyl group content, it is possible to suppress the formation of protrusions and aggregates caused by locally increasing crosslink density. ), The molecular weight is 20000 or less, and the content of the alkenylorganopolysiloxane having 3 or more alkenyl groups in one molecule is more preferably 5% by mass or less. Content of the component (A) of the said oil-in-water silicone emulsion (I) is 20-60 mass%. When it exceeds 60% by mass, the viscosity of the aqueous emulsion is increased and the handleability may be deteriorated. More preferably, it is 25-55 mass%.

  The alkenyl group-containing polyorganosiloxane of component (A) is produced by a method known to those skilled in the art, and includes an acid catalyst such as sulfuric acid, hydrochloric acid, nitric acid, activated clay, tris (2-chloroethyl) phosphite, Or use a base catalyst such as lithium hydroxide, sodium hydroxide, potassium hydroxide, tetramethylammonium hydroxide, tetra-n-butylammonium hydroxide, tetra-n-butylphosphonium hydroxide, sodium silanolate, potassium silanolate, etc. It can be produced by condensation and / or ring-opening polymerization of linear and / or cyclic low molecular weight siloxanes.

(Ingredient (B))
Component (B) is a white metal catalyst. This can be used as a hydrosilylation catalyst. The white metal catalyst (B) is made of a metal or a compound containing this metal. As the metal constituting the white metal catalyst (B) or a compound thereof, for example, platinum, rhodium, palladium, ruthenium, and iridium, preferably platinum, or a compound containing these metals can be used. Of these, platinum-based catalysts are particularly preferred because of their high reactivity. The metal may be fixed to a particulate carrier material (for example, activated carbon, aluminum oxide, silicon oxide). Platinum compounds include platinum halides (for example, reaction products comprising PtCl ₄ , H ₂ PtCl ₄ .6H ₂ O, Na ₂ PtCl ₄ .4H ₂ O, H ₂ PtCl ₄ .6H ₂ O and cyclohexane), platinum. -Olefin complexes, platinum-alcohol complexes, platinum-alcolate complexes, platinum-ether complexes, platinum-aldehyde complexes, platinum-ketone complexes, platinum-vinylsiloxane complexes (e.g., platinum-1,3-divinyl 1,1,3, 3-tetramethyldisiloxane complex, bis- (γ-picoline) -platinum dichloride, trimethylenedipyridine-platinum dichloride, dicyclopentadiene-platinum dichloride, cyclooctadiene-platinum dichloride, cyclopentadiene-platinum dichloride), bis ( Alkynyl) bis (triphenylphosphine) Examples include platinum complexes and bis (alkynyl) (cyclooctadiene) platinum complexes. The hydrosilylation catalyst can also be used in a microencapsulated form. In this case, the particulate solid containing a catalyst and insoluble in the polyorganosiloxane is, for example, a thermoplastic resin (for example, a polyester resin or a silicone resin). The platinum-based catalyst can be used in the form of an inclusion compound, for example, in cyclodextrin.

  In the silicone emulsion (I), the amount of the white metal catalyst (B) is 1 to 500 ppm, preferably 5 to 200 ppm, based on the weight of the diorganopolysiloxane (A). Preferably it contains in the quantity used as 20-100 ppm. If the content is less than 1 ppm, it takes time to cure and the production efficiency may be deteriorated. If it exceeds 500 ppm, the pot life of the coating liquid may be shortened, which may cause a decrease in productivity due to gelation of the coating liquid.

(Ingredient (C))
Component (C) is a dicarboxylic acid alkenyl ester. As the dicarboxylic acid alkenyl ester (C), those known as reaction inhibitors can be used. Examples of the dicarboxylic acid alkenyl ester (C) include diallyl maleate, butyl maleate, diallyl succinate, dimethyl maleate, diethyl maleate, silyl maleate and the like. More preferably, component (C) contains diallyl maleate. Content of the component (C) in the said oil-in-water silicone emulsion (I) is 0.01-3 mass% in the silicone emulsion (I) of this invention, Preferably it is 0.05-0.5 mass%. It is. If it is less than 0.01% by mass, the reaction suppressing effect is low and the pot life may be shortened. If it exceeds 3% by mass, the reaction rate may be remarkably slowed.

(Component (D))
Component (D) is a nonionic surfactant. The nonionic surfactant (D) is preferably a nonionic surfactant having an HLB value representing a balance between hydrophilicity and lipophilicity of 8.0 to 19.0, particularly preferably 10.0 to 18.0, Preferably it is 10.0-16.0. Any nonionic surfactant within this HLB value range is not particularly limited. Even if it can emulsify if the HLB value of the surfactant to be used is not appropriate, storage stability and dilution stability are poor and sufficient performance cannot be exhibited. A surfactant having a low HLB value may be used in combination as another emulsification aid.

  Examples of such nonionic surfactants include sorbitan fatty acid esters, glycerin fatty acid esters, decaglycerin fatty acid esters, polyglycerin fatty acid esters, propylene glycol pentaerythritol fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbit fatty acid esters. , Polyoxyethylene glycerin fatty acid ester, polyethylene glycol fatty acid ester, polyoxyethylene alkyl ether, polyoxyethylene polyoxypropylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene castor oil, hydrogenated castor oil, polyoxyethylene alkylamine Examples include fatty acid amides and polyalkyl glycosides. These nonionic surfactants are preferable from the viewpoint of safety, stability and price, and can be used alone or as a mixture of two or more. In particular, polyoxyethylene alkyl ether is preferable from the viewpoint of emulsion stability. Content of the component (D) in the silicone emulsion (I) in this invention is 1-10 mass%. When the amount is less than 1% by mass, emulsification is difficult. When the amount exceeds 10% by mass, the viscosity of the aqueous emulsion composition increases and the handleability deteriorates. More preferably, it is 3-6 mass%.

(Ingredient (E))
Ingredient (E) is water. Although it does not specifically limit as water (E), It is preferable to use ion-exchange water, Preferably it is pH 2-12, Most preferably, it is pH 4-10. Use of mineral water is not recommended, but when used, it is preferably used in combination with a metal deactivator. The amount of water used in the emulsification is 20-80% by mass, preferably 35-70% by mass in the silicone emulsion (I) of the present invention. The emulsion of the present invention is stable to dilution with water and can be further diluted after the emulsion is prepared, and the amount of the diluted water is not particularly limited. Since the oil-in-water silicone emulsion of the present invention is a water solvent system, it is preferable from the viewpoint of consideration for the environment as compared with a system using a solvent.

[Oil-in-water silicone emulsion (II)]
The oil-in-water silicone emulsion (II) contains the following components (F), (G) and (H).

(Ingredient (F))
The component (F) is an organohydrogenpolysiloxane having an average composition formula represented by the general formula (2) and containing two or more hydrogen atoms bonded to silicon atoms in one molecule.

The organohydrogenpolysiloxane (F) is a crosslinking component for the component (A) and is represented by the following average composition formula (2).
R ³ _c H _d SiO _{(4-cd) / 2} (2)
In formula (2), R ³ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated group, c is 1 to 3, d is 0.01 to 2, and c + d is 1 to 3. As R ^{3 in the} formula (2), the hydrocarbon group exemplified in the above R ¹ is used, preferably an alkyl group, more preferably a methyl group. The number of hydrogen atoms bonded to the silicon atom of component (F) is preferably 3 or more per molecule. The viscosity at 25 ° C. of the organohydrogenpolysiloxane (F) is usually 1 to 3000 mPa, preferably 5 to 500 mPa.
Content of the component (F) in oil-in-water silicone emulsion (II) is 20-60 mass%. When it exceeds 60% by mass, the viscosity of the aqueous emulsion increases, and the handleability may deteriorate. More preferably, it is 25-55 mass%.

  The amount of component (F) in the composition of the present invention is blended according to the amount of alkenyl in component (A), and the number of alkenyl groups bonded to silicon atoms in component (A). The amount of (NA) and the number of hydrogen atoms bonded to silicon atoms (NF) in component (F) is 1.0 ≦ (NF / NA) ≦ 6.0, preferably 1.5 ≦ The amount is adjusted so that (NF / NA) ≦ 4.0. If NF / NA is less than 1, curing of the composition does not proceed sufficiently, and unreacted alkenyl groups remain in the coating layer. Therefore, the peel force is likely to change over time, and it becomes a migration component, resulting in residual adhesion. The rate tends to decrease. On the other hand, when NF / NA is 6 or more, the peeling force tends to increase over time due to the remaining organohydrogenpolysiloxane in the coating layer. Organohydrogenpolysiloxane (F) is also produced by methods known to those skilled in the art.

(Ingredient (G))
Component (G) is a nonionic surfactant. As the nonionic surfactant (G), the nonionic surfactant described above for the component (D) can be used in the same manner.

(Ingredient (H))
Ingredient (H) is water. As water (H), the water described above for component (E) can be used in the same manner.

  The production method of the silicone emulsions (I) and (II) of the present invention is not particularly limited, but can be produced by a known method. It can be produced by mixing and emulsifying the above components using a high-speed stator rotor stirring device or the like. In the oil-in-water silicone emulsion (I), emulsification is carried out by stirring all or part of the components (A) to (D) and (E) water to prepare a water-in-oil emulsion, and the remaining water. Was added and stirred to prepare an oil-in-water emulsion. In the oil-in-water silicone emulsion (II), all or part of the components (F), (G) and (H) water are stirred to prepare a water-in-oil emulsion, and the remaining water is added. It was prepared by stirring and making an oil-in-water emulsion. A method in which the water-in-oil emulsion is changed to the oil-in-water emulsion is preferable from the viewpoint of easy adjustment of the emulsion particle diameter and the stability of the emulsion.

  The composition of the present invention is prepared by adding silicone emulsions (I) and (II) after dilution with a diluting solvent so that the ratio of component (A) to component (F) is within the above range. The

  As a dilution solvent for the silicone emulsions (I) and (II), water is preferred. The water is not particularly limited, but it is preferable to use ion exchange water, preferably pH 2 to 12, more preferably pH 4 to 10. Use of mineral water is not recommended, but when used, it is preferably used in combination with a metal deactivator. When diluting with an organic solvent, there is no need for an organic solvent recovery facility or explosion-proof facility required in the process, which is economically advantageous and environmentally preferable.

  The emulsion composition of the present invention is an adhesion improver that is acceptable for the purpose of improving the adhesion to the film substrate within the range that does not impair the object of the present invention, or a transition component that is acceptable for the purpose of adjusting the peeling force, or , A heavy release control agent, and a preservative for antiseptic purposes. Examples of such other components include a general silane coupling agent as an adhesion improver, a migration component, an oil-in-water organosiloxane emulsion composition as a heavy release control agent, and sorbic acid and sorbine as preservatives. Examples thereof include acid salts, acetic acid, lactic acid, formalin and the like.

  The release film of the present invention is obtained by applying the oil-in-water silicone emulsion composition for coating a release film of the present invention to the surface of the film.

  Examples of the film to which the composition of the present invention is applied include vinyl resins such as polyvinyl chloride resin, polyvinylidene chloride resin and polyvinyl alcohol resin, polyester resins such as polybutylene terephthalate resin, polyethylene terephthalate resin and polyethylene naphthalate resin, , Polyethylene resin, polypropylene resin, polymethylpentene resin, polyolefin resin such as ethylene / vinyl acetate copolymer, polycarbonate, polystyrene, ionomer, polyacrylate, polymethacrylate, nylon, polyamide, polyethersulfine, poly Phenyl sulfide, polyimide, polyurethane, polyetherimide, modified polyphenylene ether, polyether ether ketone, polyacrylonitrile, norbornene, Cycloolefin, cellophane, plastics and cellulose acetate etc., vinylon, films and the like made of regenerated cellulose. Among these, a polyester resin is preferable, and polyethylene terephthalate is particularly preferable.

  The method for applying the composition of the present invention is not particularly limited. For example, gravure coating, bar coating, spray coating, spin coating, air knife coating, roll coating, blade coating, gate roll Examples thereof include a coating method, a die coating method, a doctor coating method, and a brush coating method. The composition of the present invention may be applied off-line to a plastic film after stretching or in-line coating in a stretching process at the time of plastic production. When the content of the component (B) is small, in-line coating is more preferable. In this invention, the thickness of the coating layer after drying is 0.01-1 micrometer, Preferably it is 0.01-0.5 micrometer, Most preferably, it is 0.01-0.3 micrometer.

  There is no limitation in particular in the method of hardening the composition of this invention, For example, the normal method of hardening with a heating roll, a heating drum, or a hot air drying furnace etc. is mentioned. Although it does not specifically limit as curing conditions of the composition of this invention, A coating layer is formed by processing a curing temperature at 50-250 degreeC, and drying time for 5 second-10 minutes.

  Next, the present invention will be described by way of examples. In addition, this invention is not limited by this. Moreover, preparation of the coating liquid in Examples and Comparative Examples and production of a release film were performed as follows. Moreover, the measurement method of the magnitude | size of protrusion and the number of protrusions of the obtained peeling film was performed as follows. Production conditions and measurement results are shown in Table 1.

<Preparation method of coating liquid>
Using the oil-in-water silicone emulsion (I) and the oil-in-water silicone emulsion (II) prepared in the following examples and comparative examples, a coating solution was prepared as follows.
First, 3.7 parts by mass of the oil-in-water silicone emulsion (I) and 0.12 parts by mass of the oil-in-water silicone emulsion (II) were mixed and stirred. Subsequently, 100 mass parts of water was added and the coating liquid was prepared so that the solid content of a coating liquid might be 2 mass% by stirring.

<Method for producing release film>
The coating solution prepared by the above method was applied to Teijin Tetron film G2 (thickness: 38 μm) manufactured by Teijin DuPont Films Ltd. 3 was applied. Next, a release film having a film thickness of about 0.15 μm was produced by heat-curing in an oven at 150 ° C. for 4 minutes.

<Method for measuring the number of protrusions>
The surface of the release film was observed with a scanning electron microscope, and the number of protrusions having a diameter of 5 μm or more in a measurement area of 0.04 mm ² was counted.

<Example 1>
The oil-in-water silicone emulsion (I) of Example 1 was prepared as follows. First, 50 parts by mass of a vinyl group-containing polydimethylsiloxane (A) having a viscosity of 1000 mPa · s blocked at both ends with dimethylvinylsilyl groups, and a platinum-vinylsiloxane complex solution (B ) 0.2 part by mass, diallyl maleate (C) (Tokyo Chemical Industry Co., Ltd.) 0.11 part by mass, and (D) nonionic surfactant (Pegnol T10 / 80, Toho Chemical Co., Ltd.) 6 .6 parts by mass and (E) 44 parts by mass of purified water were stirred at 4000 rpm using an IKA Ultra Tarrax T50 Basic Shaft Generator G45M to obtain the oil-in-water silicone emulsion (I) of Example 1. Prepared.
Moreover, the oil-in-water silicone emulsion (II) of Example 1 was prepared as follows. First, as an oil-in-water silicone emulsion (II), 35 parts by mass of methyl hydrogen polysiloxane (F) having a viscosity of 65 mPa · s (25 ° C.) blocked with trimethylsiloxy groups at both molecular chain ends, and (H) 5 parts by weight of a nonionic surfactant (Pegnol T10 / 80 manufactured by Toho Chemical Industry Co., Ltd.) and 60 parts by weight of (E) purified water are stirred at 4000 rpm using an Ultra-Turrax T50 Basic Shaft Generator G45M manufactured by IKA. Thus, an oil-in-water silicone emulsion (II) of Example 1 was prepared. The platinum content is 40 ppm with respect to the weight of the diorganopolysiloxane (A), and NF / NA = 3.4.
Using the prepared emulsions (I) and (II), a coating solution was prepared by the above preparation method, and a release film was prepared by the above-described release film preparation method. The number of protrusions was counted and evaluated on the surface of the release film according to the above method and criteria. The evaluation results are shown in Table 1.

<Example 2>
The oil-in-water silicone emulsion (I) of Example 2 was prepared in the same manner as in Example 1 except that the amount of the component (B) of the oil-in-water silicone emulsion (I) was 0.4 parts by mass. Using the prepared oil-in-water silicone emulsion (I) of Example 2 and the oil-in-water silicone emulsion (II) of Example 1, a coating solution was prepared by the above preparation method, and the release film was prepared by the above-described release film preparation method. Was made. The surface of the release film was evaluated by counting the number of protrusions according to the above method and criteria. The evaluation results are shown in Table 1.

<Example 3>
The oil-in-water silicone emulsion (I) of Example 3 was prepared in the same manner as in Example 1 except that the amount of the component (C) of the oil-in-water silicone emulsion (I) was 0.27 parts by mass. Using the prepared oil-in-water silicone emulsion (I) of Example 3 and the oil-in-water silicone emulsion (II) of Example 1, a coating solution was prepared by the above-described preparation method, and peeling was performed by the above-described release film preparation method. A film was prepared. The surface of the release film was evaluated by counting the number of protrusions according to the above method and criteria. The evaluation results are shown in Table 1.

<Comparative Example 1>
The component (A) contains 5.3% by mass of a component having a molecular weight of 20000 or less and 3 or more alkenyl groups in one molecule, the amount of the component (B) is 1 part by mass, and the component (C) is 1- An oil-in-water silicone emulsion (I) of Comparative Example 1 was prepared in the same manner as in Example 1 except that 0.1 part by mass of ethynyl-1-cyclohexanol (manufactured by Nissin Chemical Industry Co., Ltd.) was used. Using the prepared oil-in-water silicone emulsion (I) of Comparative Example 1 and the oil-in-water silicone emulsion (II) of Example 1, a coating solution was prepared by the above preparation method, and the release film was prepared by the above-described release film preparation method. Was made. The surface of the release film was evaluated by counting the number of protrusions according to the above method and criteria. The evaluation results are shown in Table 1.

<Comparative example 2>
The component (A) contains 5.3% by weight of a component having a molecular weight of 20000 or less and 3 or more alkenyl groups in one molecule, the amount of the component (B) is 0.16 parts by mass, and the component (C) is An oil-in-water silicone emulsion (I) of Comparative Example 2 was prepared in the same manner as in Example 1 except that 0.1 part by mass of 1-ethynyl-1-cyclohexanol (manufactured by Nissin Chemical Industry Co., Ltd.) was used. . Using the prepared oil-in-water silicone emulsion (I) of Comparative Example 2 and the oil-in-water silicone emulsion (II) of Example 1, a coating solution was prepared by the above preparation method, and the release film was prepared by the above-described release film preparation method. Was made. The surface of the release film was evaluated by counting the number of protrusions according to the above method and criteria. The evaluation results are shown in Table 1.

<Comparative Example 3>
The same as Example 1 except that the amount of the component (B) was 1 part by mass and the component (C) was 0.1 part by mass of 1-ethynyl-1-cyclohexanol (manufactured by Nissin Chemical Industry Co., Ltd.). Thus, an oil-in-water silicone emulsion (I) of Comparative Example 3 was prepared. Using the prepared oil-in-water silicone emulsion (I) of Comparative Example 3 and the oil-in-water silicone emulsion (II) of Example 1, a coating solution was prepared by the above preparation method, and the release film was prepared by the above-described release film preparation method. Was made. The surface of the release film was evaluated by counting the number of protrusions according to the above method and criteria. The evaluation results are shown in Table 1.

<Comparative example 4>
Comparison was made in the same manner as in Example 1 except that the amount of component (B) was 0.2 parts by mass and component (C) was 0.2 parts by mass of monooctyl maleate (manufactured by Tokyo Chemical Industry Co., Ltd.). The oil-in-water silicone emulsion (I) of Example 4 was prepared. Using the prepared oil-in-water silicone emulsion (I) of Comparative Example 4 and the oil-in-water silicone emulsion (II) of Example 1, a coating solution was prepared by the above preparation method, and the release film was prepared by the above-described release film preparation method. Was made. The surface of the release film was evaluated by counting the number of protrusions according to the above method and criteria. The evaluation results are shown in Table 1.

  The oil-in-water type silicone emulsion composition for release film coating of the present invention can suppress the generation of protrusions on the surface of the coating film during the production of a silicone coating on a substrate such as a film, particularly a release film. It is useful for silicone coating that maintains the surface smoothness of the protective film.

Claims (5)

An oil-in-water silicone emulsion composition for release film coating comprising an oil-in-water silicone emulsion (I) and an oil-in-water silicone emulsion (II),
The oil-in-water silicone emulsion (I) includes the following components (A) to (E):
(A) 20 to 60% by mass of a diorganopolysiloxane having an average composition formula represented by the general formula (1) and containing two or more alkenyl groups bonded to a silicon atom in one molecule;
R ¹ _a R ² _b SiO _{(4-ab) / 2} (1)
[Wherein R ¹ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated group, R ² is an alkenyl group, a is 1 to 3, b is 0.1 to 2, a + b is 1 to 3 It is. ],
(B) The amount of the white metal catalyst is 1 to 500 ppm based on the weight of the diorganopolysiloxane (A),
(C) 0.01 to 3% by mass of a dicarboxylic acid alkenyl ester,
(D) 1-10% by weight of a nonionic surfactant, and (E) 30-80% by weight of water.
Containing
The oil-in-water silicone emulsion (II) includes the following components (F) to (H):
(F) Organohydrogenpolysiloxane having an average composition formula represented by general formula (2) and containing two or more hydrogen atoms bonded to silicon atoms in one molecule: 20 to 60% by weight
R ³ _c H _d SiO _{(4-cd) / 2} (2)
[Wherein R ³ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated group, c is 1 to 3, d is 0.01 to 2, and c + d is 1 to 3]
(G) 1-10% by mass of a nonionic surfactant, and (H) 20-80% by mass of water,
An oil-in-water silicone emulsion composition for coating a release film.   The oil-in-water silicone emulsion composition for release film coating according to claim 1, wherein the dicarboxylic acid alkenyl ester (C) of the oil-in-water silicone emulsion (I) is diallyl maleate.   3. The oil-in-water silicone emulsion composition for coating a release film according to claim 1 or 2, wherein the film constituting the release film is a plastic film.   The oil-in-water silicone emulsion (I) contains the white metal catalyst (B) in an amount that the white metal metal is 5 to 200 ppm based on the weight of the diorganopolysiloxane (A). The oil-in-water silicone emulsion composition for release film coating according to any one of claims 1 to 3.   A release film obtained by applying the oil-in-water silicone emulsion composition for release film coating according to any one of claims 1 to 4 to the surface of the film.