JPH0631371B2 - Mold release coating agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Purpose of the invention [Industrial field of application] The present invention provides a release agent applied to a molding die for rubber / plastic, or a paper or plastic film such as release paper. The present invention relates to a release agent used for the purpose of imparting releasability.

[Prior art and its problems] Conventionally, for the purpose of lubricity and releasability, silicone oil, silicone grease, a fluorine compound such as an oligomer of tetrafluoroethylene or an oligomer of hexafluoropropylene oxide, n- A large number of compounds such as paraffin hydrocarbons such as dodecane and phosphoric acid esters such as tri (2-ethylhexyl) phosphoric acid ester have been used in a manner suitable for the intended use.

For the purpose of releasability, for example, a large amount of silicone oil, the above-mentioned fluorine compound, etc. have been conventionally used as a release agent from a mold at the time of molding rubber / plastic.
Since these conventional mold release agents are the same homogeneous material, it is extremely difficult to achieve both mold releasability and adhesion to the object to be coated, resulting in poor adhesion to the mold. When releasing from a mold coated with, it moves to the surface of rubber / plastic, and when coating paint on rubber / plastic, cissing and poor adhesion occur, which is a big problem. Furthermore, when repeatedly using a mold coated with these release agents,
Since the releasing effect gradually decreases, it is necessary to coat the mold with these releasing agents even if it is used several times, and the yield of the rubber / plastic molded product is greatly reduced.

Reactive silicone has been conventionally used as a release agent for papers having release properties, that is, release paper. However, when used at high temperature, for example, at 70 ° C. or higher, paper and release agent silicone Because of poor adhesion, they cannot be used because they are separated from each other. In addition, various silicones have been developed for the purpose of imparting releasability to plastic films, especially polyethylene terephthalate (hereinafter referred to as PET) films, but they are practically poor in adhesion, water resistance and moisture resistance of adhesion. I'm not satisfied.

(B) Structure of the Invention [Means for Solving the Problems] The present inventors have completed the present invention as a result of intensive studies for solving the above problems.

That is, the present invention is a radical-polymerizable silicone macromonomer (A), a radical-polymerizable monomer (B) having a hydroxyl group, and (C) a radical-polymerizable monomer other than the above-mentioned (A) and (B) are radical-copolymerized. And a release coating agent comprising a graft polymer containing 1 to 30% by weight of the (B) monomer unit and a curing agent.

The coating obtained from the coating agent has a non-uniform phase separation structure derived from the graft polymer, in which the surface of the coating (usually the air interface of the coating) has a large amount of silicone components, and the interface of the coating object is low in silicone components. By the synergistic effect of the formation of and the cross-linking curing action, the releasability and lubricity as well as the excellent adhesion to the object to be coated and the excellent water resistance of adhesion, the moisture resistance, the excellent mechanical strength of the coating, etc. are simultaneously obtained. Express.

[(A) Radical polymerizable silicone macromonomer]

The radically polymerizable silicone macromonomer referred to in the present invention is a polymer having a polymerizable functional group at one end of the molecular chain and having a number average molecular weight of 1,000 to 20,000.

The number average molecular weight in the present invention is a polystyrene reduced molecular weight by gel permeation chromatography (hereinafter referred to as GPC), and the measurement conditions are as follows.

Apparatus: High performance liquid chromatography (for example, Toyo Soda Industry Co., Ltd. trade name HLC-802UR) Column: Polystyrene gel (for example, Toyo Soda Industry Co., Ltd. trade name G4000H8 and G3000H8) Elution solvent: Tetrahydrofuran Outflow rate: 1.0 m / Min Column temperature: 40 ° C. Detector: RI detector The radical-polymerizable silicone macromonomer is obtained by the following various production methods, and any of them can be used.

An example of the production method is a method of obtaining a silicone macromonomer by reacting a living polymer obtained by anionically polymerizing a cyclic siloxane represented by the following general formula (a) with a radical-polymerized silane compound represented by the following general formula (b). (JP-A-59-126478).

(a) However, R ₁ is a methyl group, an ethyl group or a phenyl group,
P is 3 or 4.

(b) Or However, R ₂ is hydrogen or a methyl group, m is 0 or 1, R ₃ , R ₄
Is a methyl group, an ethyl group or a phenyl group, n is an integer of 1 to 3, is an integer of 0 to 2 when m = 0, and is 2 when m = 1.

The anionic polymerization of the above cyclic siloxane may be carried out according to a conventional method, and can be easily carried out by a bulk polymerization method or a solution polymerization method using a known anionic polymerization initiator.

Examples of the cyclic siloxane represented by the general formula (a) include hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, hexaethylcyclotrisiloxane, octaethylcyclotetrasiloxane, hexaphenylcyclotrisiloxane, octaphenylcyclotetrasiloxane. Among these, hexamethylcyclotrisiloxane and octamethylcyclotetrasiloxane are particularly preferable in terms of cost and ease of anionic polymerization. Examples of the anionic polymerization initiator include known compounds such as organic lithium compounds, alkali metal hydroxides, alkali metal alkoxides and alkali metal silanolates, and among these, organic lithium compounds are particularly preferable. The molecular weight of the living polymer obtained by anionic polymerization governs the molecular weight of the silicone macromonomer, and is adjusted by the molar ratio of cyclic siloxane and initiator, and the molar ratio of initiator / cyclic siloxane is preferably 0.01 to 0.2. When it is less than 0.01, the silicone macromonomer has an extremely high molecular weight (more than 20,000), and when it is more than 0.2, the silicone macromonomer has an extremely low molecular weight (1,000).
(Less than 0). The number average molecular weight of the silicone macromonomer is 1,000 to 20,000, but when the molecular weight is less than 1,000, the effect of silicone, that is,
This is because the water repellency, oil repellency, and low friction properties deteriorate, and the mold releasability also decreases slightly, and when it exceeds 20,000, the resulting coating resin tends to become oily.

The silicone macromonomer is obtained by reacting the living polymer obtained as described above with the radically polymerizable silicone compound represented by the general formula (b) (living polymerization termination reaction).
It can be obtained by The reaction is easily performed by mixing both.

The radical-polymerized silane compound represented by the general formula (b) can be easily obtained by a known method, for example, _{(R 3) 3 -nC n (} R 2 ,, m, R 3 have the same meanings as defined above), the (R _{2 and} m are the same as above) and unsaturated acrylate and / or methacrylate (hereinafter collectively referred to as (meth) acrylate) and HSi (R ₃ ) _{3 -n} C _n (R ₃ and n are the same as above) It can be obtained by a hydrosilylation reaction with The amount of the radically polymerizable silicone compound used is Si—C of the general formula (b) per 1 equivalent (1 mol) of the living polymerization initiator.
Is preferably 1 to 5 times equivalent.

Another example of the method for producing a silicone macromonomer is a silicone macromolecule obtained by subjecting a silicone represented by the following general formula (a) 'to a condensation reaction of 0.25 to 1 mole of an acrylic compound represented by the following general formula (b)' per 1 mole thereof. This is a method of obtaining a monomer (JP-A-58-154766).

(a) ′ (R ¹ and R ² are monovalent aliphatic hydrocarbon groups having 1 to 10 carbon atoms, phenyl groups or monovalent halogenated hydrocarbon groups. N is a positive number of 1 or more.) (B) ′ (R ³ is a hydrogen atom or a thimel group. R ⁴ is a methyl group, an ethyl group or a phenyl group. X is a chlorine atom, a methoxy group or an ethoxy group.) The details of this production method are described in the above-mentioned published patent publications. As the silicone represented by the general formula (a) ′, various silicones can be easily obtained, and one suitable for the purpose may be used among them, but R ¹ and R ² are methyl groups. Are particularly preferred. N in the general formula (a) ′
Is a factor that determines the molecular weight of silicone, and n is 1
˜500 is preferable, and 10 to 300 is more preferable.
If n is less than 1, the effect of silicone, that is, water repellency, oil repellency, low friction property and releasability cannot be obtained, and if n exceeds 500, the obtained silicone-based graft copolymer becomes oily and can be purified. It becomes difficult.

Examples of the acrylic compound represented by the general formula (b) ′ include γ-methacryloxypropylmethyldichlorosilane, γ-methacryloxypropylmethyldiethoxysilane, γ-methacryloxypyropyrphenyldichlorosilane, and γ-methacryloxypropylethyl. Examples thereof include dichlorosilane and γ-acryloxypropylmethyldichlorosilane. These acrylic compounds are known and can be easily obtained by reacting a silicon compound with a compound having an aliphatic multiple bond in the presence of chloroplatinic acid.

The reaction between the silicone represented by the general formula (a) 'and the acrylic compound represented by the general formula (b)' proceeds smoothly by a conventional method to obtain a silicone macromonomer. That is, the dehydrochlorination reaction proceeds when X of the acrylic compound is a chlorine atom, and the dealcohol condensation reaction proceeds when X is a methoxy group or an ethoxy group.

The reaction ratio of the silicone and the acrylic compound is 0.25 to 1 mol of the acrylic compound with respect to 1 mol of the silicone. 0.
If it is less than 25 moles, a large amount of unreacted silicone remains during the production of the coating resin, and if it exceeds 1 mole, gelation tends to occur during the production of the coating resin.

Further, as a method for producing the silicone macromonomer preferably used in the present invention, an acrylic compound represented by the following general formula (b ″) is used in place of the acrylic compound represented by the general formula (b ′), and other A raw material compound, reaction conditions and the like are the same as those disclosed in JP-A-58-154766 and a method for synthesizing a silicone macromonomer (JP-A-59-20360).

(B ″) (In the above general formula, n is an integer of 1 or 3, and the other meanings of R ³ , R ⁴ and X are the same as those in the above general formula (b ′).) 154766 or JP-A-59
The product produced by the silicone macromonomer proposed in No. 20360 is mainly composed of a silicone compound introduced into one molecule of an acrylic compound, and other unreacted raw material silicone and by-produced acrylic polyfunctional silicone (silicone). It contains, as a subordinate component, one in which two molecules of an acrylic compound have been introduced into one molecule, and the product can be usefully used as it is in the present invention as a silicone macromonomer.

The proportion of the radically polymerizable silicone macromonomer used is preferably 3 to 60% by weight, and more preferably 5 to 50% by weight, based on the total amount of the monomers (A), (B) and (C).

If the amount of silicone macromonomer used is less than 3% by weight, the desired graft polymer with excellent releasability cannot be obtained. On the other hand, if the amount of silicone macromonomer used exceeds 60% by weight, radical polymerizability deteriorates. This is because the mechanical strength of the coating is reduced and the coating becomes expensive, which is not preferable.

[(B) Radical Polymerizable Monomer Having Hydroxyl Group]

The (B) monomer in the present invention is used for the purpose of crosslinking and curing the graft polymer with a curing agent to be described later, and the (B) monomer unit is 1 to 3 in the graft polymer.
It is necessary to contain 0% by weight. If the proportion of the monomer (B) is less than 1% by weight, the chemical resistance, heat resistance and coating strength of the coating film due to cross-linking and curing will be poor, while if it exceeds 30% by weight, the same problem will occur, and the curing agent The pot life of the release coating agent obtained by mixing the graft polymer is shortened, which causes a problem in workability.

As the radically polymerizable monomer having a hydroxyl group, any radically polymerizable monomer having a hydroxyl group can be used, and examples thereof include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, and 3-hydroxypropyl. (Meth) acrylate, 2-hydroxybutyl (meth) acrylate, 3-hydroxybutyl (meth) acrylate, 2,
3-dihydroxypropyl (meth) acrylate etc. can be mentioned.

Availability of these radically polymerizable monomers,
2-hydroxyethyl (meth) acrylate is preferable in terms of cost.

[Radical polymerizable monomer other than (C), (A) and (B)]

The radical-polymerizable monomer (C) used in the present invention is other than the above-mentioned monomers (A) and (B), and examples thereof include the following.

Examples of olefin compounds include low molecular weight unsaturated hydrocarbons such as ethylene and propylene, vinyl halides such as vinyl chloride and vinyl fluoride, vinyl esters of organic acids such as vinyl acetate, styrene, styrene substitution products, and vinyl pyridine and Gonyl aromatic compounds such as vinylnaphthalene, acrylic acid, methacrylic acid, and acrylic acid and methacrylic acid derivatives including their esters and amides, acrolein, acrylonitrile, N-vinyl such as N-vinylpyrrolidone and N-vinylcaprolactam. Examples thereof include compounds, disubstituted ethylene such as vinylidene fluoride and vinylidene chloride, maleic anhydride, esters of maleic acid and fumaric acid, fluoroalkyl acrylates and fluoroalkyl methacrylates.
These radically polymerizable monomers can be used alone or in combination of two or more. Among these radically polymerizable monomers, styrene, styrene substitution products, esters of acrylic acid / methacrylic acid, fluoroalkyl acrylate, and fluoroalkyl methacrylate are preferable.

The radical polymerizable monomer has 1 to 4 carbon atoms.
It is preferable to use two or more kinds of the methacrylic acid ester having an alkyl group in combination, and it is particularly preferable to use methyl methacrylate and butyl methacrylate in combination. In that case,
When the adherend is a metal, a relatively large amount of methyl methacrylate is preferably used, and when the adherend is a Mylar film, a relatively large amount of butyl methacrylate is preferably used.

The ratio of radically polymerizable monomers used is
The total amount of (A), (B) and (C) is preferably 30 to 90% by weight, more preferably 50 to 85% by weight. If the proportion of the radical-polymerizable monomer used is less than 30% by weight, the film-forming property tends to be insufficient, and the strength and flexibility of the resulting coating tend to deteriorate, and if it exceeds 90% by weight, it is relatively high. The proportions of the radically polymerizable silicone macromonomer and the crosslinkable monomer decrease, and the releasability and strength of the coating are likely to be insufficient.

Regarding the amount of radically polymerizable monomer used, the amount of silicone macromonomer and crosslinkable monomer used is usually first determined.
It is determined by making the rest of them radically polymerizable monomers. This is because it is easy to control the chemical resistance, water resistance, heat resistance and mechanical strength due to the mold release property and cross-linking curing.

[Radical copolymerization]

As the method of radical copolymerization, a conventionally known method can be used,
For example, a radiation method, a method using a radical polymerization initiator and the like can be used, but a method using a radical polymerization initiator is preferable in terms of easiness of polymerization operation and easiness of adjusting molecular weight, and specifically, a solution using a solvent. Although any of the polymerization method, bulk polymerization method, emulsion polymerization method and the like can be carried out, each monomer is uniformly dissolved in a solvent such as toluene or methyl isobutyl ketone (hereinafter referred to as MIBK) to uniformly polymerize. The solution polymerization method which can be carried out is preferred.

The graft polymer can be easily produced by radically copolymerizing the radically polymerizable silicone macromonomer, the radically polymerizable monomer and the crosslinkable monomer by the various polymerization methods as described above.

[Curing agent]

In the present invention, a compound having a group reactive with a hydroxyl group is used as a curing agent, and examples of such a compound include a polyvalent isocyanate, a melamine curing agent, a urea resin curing agent and a polybasic acid curing agent. The cured coating film obtained by crosslinking the trunk polymer of the graft polymer by the reaction with such a curing agent has excellent adhesion to various metals and plastics, and further has solvent resistance, heat resistance, hardness and mechanical properties. Excellent in dynamic strength.

As the polyvalent isocyanate, tolylene diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, methylene bis (4-cyclohexyl isocyanate), the following formula CH ₃ CH ₂ C [CH ₂ OCONH (CH ₂ ) ₆ NCO] ₃ and And the like, and these can be used alone or in combination of two or more kinds.

When performing room temperature curing using isocyanates,
It is also possible to accelerate the curing by adding a known catalyst such as dibutyltin dilaurate. The amount of the polyvalent isocyanate used as a curing agent is determined according to the hydroxyl group amount (OH equivalent) based on the above-mentioned hydroxyl group-containing radically polymerizable monomer in the graft polymer of the present invention.

Usually, the amount of polyvalent isocyanate used is determined so that the amount of isocyanate (NCO equivalent) is approximately equal to the OH equivalent.

Further, the graft polymer in the present invention, by using a melamine curing agent, a urea resin curing agent, a polybasic acid curing agent or the like used in a usual heat-curable acrylic paint, by heat-curing the polyvalent isocyanate curing agent. Excellent physical properties (adhesion, water resistance of adhesion, moisture resistance, solvent resistance,
An excellent release coating agent having heat resistance, strength, etc.) can be obtained. Examples of the melamine curing agent include butylated melamine, methylated melamine, and epoxy-modified melamine, and those with various degrees of modification can be used depending on the application, and the degree of self-condensation can be appropriately selected. Examples of the urea resin include methylated urea and butylated urea.
Further, as the polybasic acid curing agent, long-chain aliphatic dicarboxylic acids, aromatic polyvalent carboxylic acids or their anhydrides are useful.

When using a melamine or urea curing agent, the curing can be accelerated by adding an acidic catalyst.

The heat curing condition is usually at a temperature of 80 to 200 ° C. for 5 minutes to 6
It is a heating time of 0 minutes.

As the curing agent, a melamine curing agent is preferable from the viewpoint of easy control of coating hardness and control of heat crosslinking.

The amount of melamine curing agent used is the same as in the case of ordinary heat-curable acrylic paint. That is, the amount of melamine is determined according to the amount of hydroxyl groups in the graft polymer, but there is also condensation of the melamine curing agent itself, and the amount of melamine also differs depending on the application. The amount of the melamine curing agent in the total amount of the agents is 10 to 50% by weight.

[Filler, pigment, stabilizer]

Various fillers, pigments and the like can be added to the release coating agent of the present invention. Examples of them are various silicas, various clays, calcium carbonate, magnesium carbonate, titanium oxide, iron oxide, glass fibers, dispersion stabilizers,
An ultraviolet absorber or the like can be used.

Further, a resin other than the present graft polymer, for example, an acrylic resin, an epoxy resin, an unsaturated polyester resin or the like can be blended in the release coating agent of the present invention.

[Subject]

Main objects to be coated with the release coating agent of the present invention are plastic or metal molds, plastic films and papers, and the plastic film or paper coated with the release coating agent is a release film. Alternatively, it is preferably used as a release paper in the field of adhesive tapes and adhesive sheets.

[Action]

The release coating agent of the present invention shows extremely excellent adhesion to various objects to be coated, water resistance of adhesion, and moisture resistance, so that the coating film obtained from the release coating agent of the present invention is The formation of a non-uniform phase separation structure derived from a graft polymer, in which there is a large amount of silicone components on the surface of the coating and a small amount of silicone components at the interface of the coating object, and the synergistic effect of the crosslinking and curing action Conceivable.

Furthermore, in the mold release coating agent of the present invention, since the bond between the silicone component of the silicone macromonomer (A) and the radical polymerizable monomer (C) component is not bonded by a Si-O-C bond, hydrolysis resistance is high. It is thought that this is because it has excellent properties and the action of the water repellent effect of silicone is added.

The reason why the film itself exhibits excellent mechanical strength, heat resistance and chemical resistance is considered to be because the film is crosslinked and cured.

Based on such an action, excellent releasability having practical value can be exhibited on the surface of the coating film, and in addition, excellent lubricity can be exhibited in association therewith.

[Reference Example, Example and Comparative Example]

The present invention will be described more specifically below with reference to Reference Examples, Examples and Comparative Examples.

The evaluation of the film physical properties in each example was carried out by the following methods. Parts and% represent parts by weight and% by weight, respectively.

Releasability: Using an object to be coated coated with the coating agent of the present invention as a sample, KOKUYO cellophane tape (24 mm width) is pressure-bonded to the coating surface, and the cellophane tape is pulled by a tensile tester at a pulling speed of 200 mm / min × 25 ° C × It was expressed as the tensile strength (g) when peeled at 180 ° under the condition of 60% RH.

Adhesion (1): A knife-like cut was made on a coated object coated with the coating agent of the present invention with a knife, and the gouged eyes were peeled off with a cellophane tape. It was

Adhesion (2): A coating film as shown in Fig. 1 was formed and the Teflon sheet 3 was removed as a sample. A part of the film was pinched with tweezers and pulled in the direction of the arrow to adhere the film to the coating object. The sex was observed. When the A portion of the coating film was destroyed, it was indicated by ◯ (adhesion was good), and when the B portion of the coating was peeled off, it was indicated by X (adhesion was poor).

Adhesion water resistance: After the sample obtained by the test method of the adhesion (2) is immersed in boiling water for a predetermined time, the sample is taken out of the boiling water and cooled, and then the adhesion (2) is evaluated. The water resistance of adhesion was evaluated in accordance with.

Heat resistance of coating film: The article coated with the coating agent of the present invention is placed in a dryer at 150 ° C. for 1 hour,
The presence or absence of tack on the surface of the coating at ℃ was evaluated as heat resistance.
The tack was tack when the gauze was pressed against the surface of the coating and released, and there was heat resistance when there was no tack (indicated by a circle) and no heat resistance when there was tack (indicated by a cross).

Solvent resistance of coating: A coating obtained by coating a Teflon sheet with the coating agent of the present invention was immersed in a predetermined solvent for 1 week at room temperature, and the solvent resistance of the coating was observed. When the coating retains the same shape as before dipping, it is marked with ○ (solvent resistance is good), and when it becomes swollen, it is marked with △ (poor solvent resistance), when the coating dissolves and loses its shape. Is marked with x (solvent resistance is extremely poor).

Surface hardness of coating film: The coating agent of the present invention was coated on a glass plate and evaluated according to JIS K5400 (Paint General Test Method, 6-14 Pencil Scratch Test). The weight was 1 kg, and the pencil hardness when scratches were observed and the pencil hardness when breakage of the film was observed were measured.

Lubricity: Dynamic friction coefficient (μk) measured using the sample rotary type frictional force measuring device manufactured by Seimitsu Enterprise Co., Ltd., using a circular object with a diameter of 8 cm coated with the coating agent of the present invention as a sample under the following conditions: ). Note that μk
Is the average value of the measurement time of 10 minutes.

Contact: 30mmR sapphire load *: 15g (* load applied to the coating surface through the contact) Peripheral speed: 93.2cm / Sec Time: 10 minutes (friction measurement time) Temperature: 25 ° C Humidity: 60% RH Reference Example 1 0.5 g of potassium metal (0.0128 (mo) and n in a flask)
About 5 m of hexane was added, and 10 m of methanol was added dropwise over 30 minutes in an ice bath under a stream of dry nitrogen. 30 more
After stirring for minutes, excess methanol and n-hexane were distilled off under reduced pressure. Subsequently, 40 g (0.135 mo) of octamethylcyclotetrasiloxane and 40 g of tetrahydrofuran were thoroughly dehydrated with molecular sieves, and the mixture was heated under reflux for 4 hours.

(Molar ratio).

After the temperature of the reaction solution has dropped to room temperature, 31 g of a 10% tetrahydrofuran solution of γ-methacryloxypropyldimethylchlorosilane (γ-methacryloxypropylmethylchlorosilane 0.0141mo) is gradually added dropwise, and after completion of the addition, further 30 minutes at room temperature It was stirred.

Met. After filtering off the formed precipitate of potassium chloride,
The filtrate was poured into 1 of methanol to precipitate the silicone macromonomer. After decanting and drying, 26.0 g of a colorless and transparent oily silicone macromonomer was obtained.

The silicone macromonomer had a polystyrene reduced number average molecular weight by GPC of 8,900.

Next, 10 parts of the obtained silicone macromonomer, 42 parts of methyl methacrylate (abbreviated as MMA above), 42 parts of butyl methacrylate (abbreviated as BMA hereinafter), and 2-hydroxyethyl methacrylate (abbreviated as HEMA hereinafter) 6
Methyl isobutyl ketone (hereinafter abbreviated as MIBK) 15
0 part and 0.5 part of azobisisobutyronitrile (hereinafter abbreviated as AIBN) were placed in a flask equipped with a condenser, a stirrer and a thermometer, and polymerized under N _{2 at} a temperature of 75 ° C. for 5 hours,
After that, 0.5 part of AIBN was added, and the mixture was added at a temperature of 75 ° C.
Polymerized for hours. Thus, a 40% MIBK solution of the hydroxyl group-crosslinkable curable graft polymer was obtained.

Reference Example 2 4 equipped with stirrer, thermometer, condenser, N ₂ inlet tube
Α, ω-dihydroxypolydimethylsiloxane in a two-necked flask (0.15 mol), 12.4 g (0.05 mol) of γ-methacryloxypropyltrimethoxysilane, and 3.5 g of potassium acetate were charged and reacted under N _{2 at} a temperature of 150 ° C. for 20 hours. After cooling, the reaction product was poured into 1360 g of toluene to precipitate potassium acetate, and potassium acetate was removed by filtration. Thus obtained silicone macromonomer 20% toluene solution 50 parts, MMA 42 parts, BMA 42 parts, HEMA
Polymerization was carried out in the same manner as in Reference Example 1 using 6 parts, MIBK 110 parts and AIBN 0.5 part to obtain a 40% solution of the hydroxyl group cross-linking curable present graft polymer.

Reference Example 3 α, ω-dihydroxydimethylpolysiloxane as a silicone [ N is 30 on average], and 220 g (0.1 mol) and 9.49 g (0.12 mol) of pyridine are added to diethyl ether 400
A 10% diethyl ether solution of 22.06 g (0.1 mol) of γ-methacryloxypropyldimethylchlorosilane was gradually added dropwise to the solution dissolved in m at room temperature over 20 minutes.

The reaction proceeded immediately and white crystals of pyridine hydrochloride were precipitated. After completion of dropping, the mixture was further stirred at room temperature for 1 hour, and crystals of pyridine hydrochloride were removed by filtration.

Next, this filtrate was placed in a separating funnel, and 500 m of water was further added, and the mixture was shaken well and washed with water. After washing with water, the separating funnel was left still to separate the upper ether layer and the lower aqueous layer, anhydrous Glauber's salt was added to the obtained ether layer, and the mixture was left at room temperature overnight for dehydration. Thereafter, anhydrous Glauber's salt was removed by filtration, and the obtained liquid was distilled under reduced pressure to remove ether, thereby obtaining 205 g of a colorless and transparent silicone macromonomer.

10 parts of the above silicone macromonomer, 45 parts of MMA,
30 parts of ethyl acrylate (hereinafter abbreviated as EA), HEM
A15 parts, MIBK 150 parts, AIBN 0.5 parts,
Then, polymerization was carried out in the same manner as in Reference Example 1 to obtain a 40% solution of the hydroxyl group cross-linking curable present graft polymer.

Reference Example 4 15 parts of the silicone macromonomer obtained in Reference Example 1,
50 parts styrene, 29 parts butyl acrylate, HEMA
Polymerization was performed in the same manner as in Reference Example 1 using 6 parts, MIBK 150 parts, and AIBN 0.5 part to obtain a 40% solution of the hydroxyl group-crosslinking curable gulatopolymer.

Example 1 40% MIBK solution 2 of the present graft polymer of Reference Example 1
5 parts, Nippon Polyurethane Industry Co., Ltd. Coronate EH1.
1 part and 0.005 part of dibutyltin dilaurate were mixed and further diluted with MEK to obtain a solution having a solid content of 20%. The solution was applied to a PET film having a thickness of 50 μm using a bar coater, air-dried, and then dried at a temperature of 70 ° C. for 0.5 hours. The coating is extremely smooth, colorless and transparent without cissing, and 20μ
It was m thick.

The PET film surface coating thus obtained was evaluated for each item according to the method for evaluating physical properties of coating film described above. The results are shown in Table 1 as Example 1. The solvent resistance of the coating and the surface hardness of the coating were evaluated by coating in the same manner as above according to the method for evaluating physical properties of coating. In this case as well, the coating thickness was 20 μm. The results are also shown in Table 1 as Example 1.

Example 2 Using a 40% solution of the present graft polymer of Reference Example 2, the same operation as in Example 1 was carried out to obtain a PET film surface coated product, and the physical properties of the coating film were evaluated in the same manner as in Example 1.

The results are shown in Table 1 as Example 2.

Example 3 15 parts of Cymel 266J (trade name of Mitsui Toatsu Chemicals, Inc.) as a melamine curing agent and 0.5 part of P-toluenesulfonic acid were added and mixed with 100 parts of a 40% solution of the graft polymer of Reference Example 3. Then, it was further diluted with MEK to obtain a solution having a solid content of 20%. The solution was coated on a plate A using a bar coater, air-dried and then heated at 200 ° C. for 30 minutes. The coating is extremely smooth, colorless and transparent without cissing, and 10μ
It was m thick.

The coating physical properties of the thus-obtained A plate surface coating were evaluated in the same manner as in Example 1. The results are shown in Table 1 as Example 3.

Example 4 Using a 40% solution of the present graft polymer of Reference Example 4, the same operation as in Example 1 was carried out to obtain a PET film surface coating product, and the physical properties of the coating film were evaluated in the same manner as in Example 1. The results are shown in Table 1 as Example 4.

Example 5 10 parts of the silicone macromonomer obtained in Reference Example 3,
MMA 42 parts, BMA 42 parts, HEMA 6 parts, MIBK
Polymerization was carried out in the same manner as in Reference Example 1 using 150 parts of AIBN and 0.5 part of AIBN to obtain a 40% solution of the hydroxyl group cross-linking curable present graft polymer.

25 parts of the obtained solution, 1.1 parts of Coronate EH manufactured by Nippon Polyurethane Industry Co., Ltd., and 0.005 part of dibutyltin dilaurate were mixed and further diluted with MEK to obtain a solution having a solid content of 5%. The solution was applied to a PET film having a thickness of 12 μm by using a bar coater, air-dried and then dried at a temperature of 70 ° C. for 0.5 hours. The coating was extremely smooth, colorless and transparent with no cissing, and 0.7 μm thick.

The film physical properties of the PET film surface coating thus obtained were evaluated in the same manner as in Example 1. The results are shown in Table 1 as Example 5. In this case, since the coating thickness was as thin as 0.7 μm, the evaluation of the adhesiveness (2) was not performed. Further, the water resistance of adhesion is obtained by immersing the PET film surface coating obtained as described above in boiling water for a predetermined time and then taking it out, and removing the adhered water with paper, and then the adhesion (1)
The water resistance of the adhesiveness was evaluated according to the evaluation method of 1.

Comparative Example 1 In the polymerization of Reference Example 1, silicone macromonomer 10 was used.
Part, MMA 45 part, BMA 45 part, MIBK 150 part,
Polymerization was carried out in the same manner as in Reference Example 1 using 0.5 part of AIBN to obtain a 40% solution of a graft polymer containing no crosslinkable monomer. The solution is diluted with MEK to obtain a solid content of 2
A 0% solution was prepared, and the same operation as in Example 1 was performed to obtain a PET film surface coating product.
It evaluated similarly to. The results are shown in Table 1 as Comparative Example 1.

(C) Effect of the Invention The release coating agent of the present invention has excellent release properties on the coating surface, and also has excellent adhesiveness to an object to be coated, and also has excellent durability. It is industrially useful as a mold release agent, a mold release agent for molding rubber plastics, and the like.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic view showing a measurement state of adhesion (2). 1. …… Coating 2. …… The object to be coated 3. ...... 5 μm thick Teflon sheet 4. …… Direction of pulling the coating A …… A portion of the coating on the top of the Teflon sheet B …… A portion of the coating that is in direct contact with the object to be coated

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Claims (1)

[Claims] 1. A radical-polymerizable silicone macromonomer (A), a radical-polymerizable monomer (B) having a hydroxyl group, and a radical-polymerizable monomer (C) other than (A) and (B) are radical-copolymerized. And a release coating agent comprising a graft polymer containing 1 to 30% by weight of the (B) monomer unit and a curing agent.