KR20230009094A - Silicone conformal coating composition, silicone cured film prepared therefrom, and use thereof - Google Patents

Abstract

The present invention relates to a silicone conformal coating composition, a cured film prepared therefrom, and uses thereof, wherein the composition contains: (a) alkoxy-terminated polydialkylsiloxane; (b) polydialkylsiloxane having a terminal group including a (meth)acrylate group and a hydroxyl group; (c) dihydroxy-terminated polydialkylsiloxane terminated with hydroxyl groups at both ends; (d) a curing catalyst; and (e) a photoinitiator.

Description

Silicone conformal coating composition, silicone cured film prepared therefrom and its use {Silicone conformal coating composition, silicone cured film prepared therefrom, and use thereof}

The present invention relates to a silicone conformal coating composition, a cured silicone film prepared therefrom, and uses thereof.

Conformal coating material is a polymer cured film that protects electronic components while maintaining the outline of a printed circuit board (PCB). there is. In particular, silicone-based conformal coating materials are widely used because they are stable in a wide range of temperature and humidity conditions and have excellent physical properties such as elasticity, impact resistance, and dielectric strength.

On the other hand, a room temperature moisture-curable composition capable of reacting with moisture in the air at room temperature to form a cured film is advantageous for application to electric/electronic devices because it does not require additional heating for curing, and a silicone-based conformal coating material capable of room temperature moisture curing Research to develop is ongoing.

However, the conventional moisture-curable silicone-based composition has a slow curing rate, low productivity, and is not suitable for mass production. In addition, in order to increase adhesion with the substrate, the hardness of the cured film is lowered and the surface tends to be sticky, and thus, there is a problem that the cured film is damaged or easily peeled off.

That is, it is required to develop a silicone-based composition capable of simultaneously improving adhesion to a substrate and improving surface stickiness, while maintaining excellent physical properties of a conventional silicone-based cured film and having an improved curing speed.

KR 10-2020-0125578 A

The present invention has been made to solve the above problems, to provide a silicone conformal coating composition capable of curing at room temperature and significantly shortening the curing time when preparing a cured film.

In addition, an object of the present invention is to provide a cured film capable of realizing excellent physical properties by using the silicone conformal coating composition and having improved stickiness on the surface, and an electronic device including the cured film.

For the purpose described above, the present invention provides (a) an alkoxy-terminated polydialkylsiloxane having a terminal group represented by the following formula (1); (b) a polydialkylsiloxane having a terminal group including a (meth)acrylate group and a hydroxyl group; (c) a dihydroxy-terminated polydialkylsiloxane terminated with hydroxyl groups at both ends; (d) a curing catalyst; And (e) a photoinitiator; it provides a silicone conformal coating composition comprising a.

[Formula 1]

(In Formula 1 above,

R ₁ is (C1-C10)alkyl or (C2-C10)alkenyl;

R ₂ is (C1-C10)alkyl;

a is an integer of 0 or 1.)

According to an embodiment of the present invention, the (a) alkoxy-terminated polydialkylsiloxane has a viscosity of 1,000 to 80,000 cps, and (b) the viscosity of the polydialkylsiloxane is 100 to 30,000cps, and (c) the viscosity of the dihydroxy-terminated polydialkylsiloxane may be 1,000 to 80,000cps.

According to an embodiment of the present invention The (b) terminal group including a (meth)acrylate group and a hydroxyl group may be represented by Formula 3 below.

[Formula 3]

(In Formula 3,

R ₅ is hydrogen or (C1-C6)alkyl.)

The (b) polydialkylsiloxane according to an embodiment of the present invention may be represented by Formula 4 below.

[Formula 4]

(In Chemical Formula 4,

R ₅ is hydrogen or (C1-C6)alkyl;

R ₁₁ to R ₁₆ are each independently (C1-C6)alkyl;

p is a real number from 1 to 2,000.)

The silicone conformal coating composition according to an embodiment of the present invention may further include an adhesion imparting agent, fumed silica, or a combination thereof.

In addition, the present invention provides a silicone cured film obtained by photocuring and moisture curing the silicone conformal coating composition.

The ultraviolet moisture silicone conformal coating composition according to the present invention can be cured at room temperature when preparing a cured film, can implement a very fast curing speed, and can provide a cured film having excellent physical properties and excellent adhesion to a substrate.

Specifically, since the silicone conformal coating composition according to the present invention has a very fast curing speed even at room temperature, it is possible to shorten the process time, reduce cost, improve economic feasibility, and be easily applied to mass production. there is. In addition, the silicone conformal coating composition has excellent flowability and wettability, so workability is good, and a cured film having a uniform thickness can be prepared, and adhesion between the substrate and the cured film can be further improved.

In addition, the cured film prepared from the silicone conformal coating composition not only has excellent adhesion to the substrate, but also can effectively improve the stickiness of the cured film surface, thereby solving the problem of damage to the cured film surface or easy peeling. there is.

That is, the silicone conformal coating composition according to the present invention can improve the curing speed problem of conventional moisture-curable silicone-based compositions, and simultaneously satisfy the adhesive strength and physical properties of a cured film prepared therefrom.

Hereinafter, the present invention will be described in more detail. If there is no other definition in the technical terms and scientific terms used at this time, they have meanings commonly understood by those of ordinary skill in the art to which this invention belongs, and will unnecessarily obscure the gist of the present invention in the following description. Descriptions of possible known functions and configurations are omitted.

Throughout the specification describing the present invention, the phrase "includes" a certain element means that a part may further include other elements, not excluding other elements unless otherwise stated. can

Unless otherwise defined herein, when a part such as a layer, film, thin film, region, plate, etc. is said to be "on" or "on" another part, this means not only when it is "directly on" the other part, but also in the middle thereof. It may also include the case where there is another part in .

As used herein, the term "hybrid curing" may mean that both curing by light irradiation and curing by moisture are possible.

As used herein, the term "tack free time" may refer to the time until the surface is hardened and the sample does not stick to the pipette or hand.

As used herein, the term "complete curing time" may mean the time until the center of the cured film is completely cured.

As used herein, the term "(meth)acrylate" may mean methacrylate or acrylate at the same time.

Hereinafter, the present invention will be specifically described.

Room-temperature moisture-curing silicone-based cured films have been widely used because they are stable in a wide range of temperature and humidity conditions, have excellent physical properties such as elasticity, impact resistance, and dielectric strength, and do not require a heating process when producing cured films. However, the conventional moisture-curable silicone-based composition has a low curing rate and low productivity, and is not suitable for mass production. In addition, in order to increase adhesion with the substrate, the hardness of the cured film is lowered and the surface tends to be sticky, and thus, there is a problem that the cured film is damaged or easily peeled off.

As a result of many studies to solve the above problems, the inventors of the present invention, alkoxy-terminated polydialkylsiloxane; polydialkylsiloxane having a terminal group including a (meth)acrylate group and a hydroxyl group; dihydroxy terminated polydialkylsiloxanes; curing catalyst; And photoinitiator; when using a composition containing a photocuring and moisture curing, it was found that the curing rate can be greatly shortened and a cured film having excellent physical properties can be provided.

That is, the composition having the above structure can realize excellent adhesion to the substrate and surface stickiness improvement effect at the same time while maintaining excellent physical properties compared to conventional moisture-curable silicone-based compositions, and can significantly accelerate the curing speed. discovered and completed the present invention.

Hereinafter, each configuration of the present invention will be described in more detail. However, this is merely an example and the present invention is not limited to the specific embodiments described as examples.

A silicone conformal coating composition according to one aspect of the present invention includes (a) an alkoxy-terminated polydialkylsiloxane having a terminal group represented by Formula 1 below; (b) a polydialkylsiloxane having a terminal group including a (meth)acrylate group and a hydroxyl group; (c) a dihydroxy-terminated polydialkylsiloxane terminated with hydroxyl groups at both ends; (d) a curing catalyst; And (e) a photoinitiator; may be one containing.

[Formula 1]

(In Formula 1 above,

R ₁ is (C1-C10)alkyl or (C2-C10)alkenyl;

R ₂ is (C1-C10)alkyl;

a is an integer of 0 or 1.)

As the silicone conformal coating composition according to one aspect of the present invention includes the above components as components, a chemical reaction such as a curing reaction is induced between the components, thereby providing a cured film that realizes excellent durability. In addition, it is possible to secure excellent adhesion between the cured film and the substrate after curing, and at the same time, it is possible to improve the phenomenon in which stickiness remains on the surface of the cured film. In addition, it is possible to remarkably shorten the surface curing time (tack free time, TFT) and complete curing time when producing a cured film.

Specifically, the silicone conformal coating composition according to one aspect of the present invention includes (a) an alkoxy-terminated polydialkylsiloxane, (b) a (meth)acrylic group and a hydroxyl group-containing polydialkylsiloxane, and (c) a dihydroxy-terminated polydialkylsiloxane. By using polydialkylsiloxane together, hybrid curing is possible, which not only significantly shortens the curing time even at low temperatures such as room temperature, but also effectively improves the phenomenon that the surface of the cured film remains sticky after curing is completed. can

R ₁ in Formula 1 according to an aspect of the present invention may preferably be (C1-C6)alkyl or (C2-C6)alkenyl, more preferably (C1-C3)alkyl or (C2-C3)alke could be Neil. In addition, R ₂ may be preferably (C1-C6)alkyl, more preferably (C1-C3)alkyl.

The (a) alkoxy-terminated polydialkylsiloxane according to an aspect of the present invention may be represented by Formula 2 below as an example thereof.

[Formula 2]

(In Formula 2 above,

R ₁ is (C1-C6)alkyl or (C2-C6)alkenyl;

R ₂ to R ₄ are each independently (C1-C6)alkyl;

a is an integer of 0 or 1;

n is a real number from 1 to 2,000.)

According to an aspect of the present invention, R ₃ and R ₄ may each independently be (C1-C3)alkyl, and the (a) alkoxy-terminated polydialkylsiloxane is more preferably represented by Formula 2-1 below. can

[Formula 2-1]

(In Chemical Formula 2-1,

The definitions of R ₁ , R ₂ , a and n are the same as those in Formula 2 above.)

The (a) alkoxy-terminated polydialkylsiloxane according to one aspect of the present invention may be more preferably represented by Formula 2-2 or 2-3.

[Formula 2-2]

[Formula 2-3]

(In Chemical Formulas 2-2 and 2-3,

R is (C1-C6)alkyl;

R' is (C1-C6)alkyl or (C2-C6)alkenyl;

n and m are each independently a real number from 1 to 1,000.)

In addition, the (a) alkoxy-terminated polydialkylsiloxane according to one aspect of the present invention may have a viscosity value of 1,000 to 80,000 cps, preferably 5,000 to 30,000 cps, as measured by a Brookfield viscometer at a temperature of 25 ° C. there is. When the above viscosity range is satisfied, not only can workability be improved, but also wettability and flowability of the silicone conformal coating composition can be further improved. In addition, surface contact with the substrate can be improved, and adhesion between the substrate and the cured film can be further improved.

The terminal group including the (b) (meth)acrylate group and the hydroxyl group according to one aspect of the present invention may be represented by Formula 3 below as an example thereof.

[Formula 3]

(In Formula 3,

R ₅ is hydrogen or (C1-C6)alkyl.)

As (b) polydialkylsiloxane according to one aspect of the present invention simultaneously includes a hydroxyl group and a (meth)acrylate group as shown in Chemical Formula 3, the surface curing rate of the silicone conformal coating composition can be further improved. In addition, it is possible to more effectively improve the surface stickiness of the cured film after curing. When a vinyl group or an allyl group is included instead of the (meth)acrylate group, stickiness may remain on the surface of the cured film even after complete curing, which is not preferred.

As an example, the (b) polydialkylsiloxane according to an aspect of the present invention may be represented by Formula 4 below.

[Formula 4]

(In Chemical Formula 4,

R ₅ is hydrogen or (C1-C6)alkyl;

R ₁₁ to R ₁₆ are each independently (C1-C6)alkyl;

p is a real number from 1 to 2,000.)

According to an aspect of the present invention, R ₅ may be hydrogen or (C1-C3)alkyl, and R ₁₁ to R ₁₆ may each independently be (C1-C3)alkyl, wherein p is 10 to 2,000 Could be a mistake.

More preferably, the (b) polydialkylsiloxane may be represented by the following Chemical Formula 4-1.

[Formula 4-1]

(In Chemical Formula 4-1,

R ₅ is hydrogen or (C1-C3)alkyl;

p is a real number from 1 to 2,000.)

In addition, the (b) polydialkylsiloxane according to an aspect of the present invention may have a viscosity value of 100 to 30,000 cps, preferably 500 to 20,000 cps, as measured by a Brookfield viscometer at a temperature of 25 °C. When the above viscosity range is satisfied, wettability and spreadability of the silicone conformal coating composition according to an aspect of the present invention may be further improved, and adhesion between the substrate and the cured film may be further improved. Also, the curing time can be accelerated.

In addition, the (b) polydialkylsiloxane is not limited as long as the object of the present invention is achieved with respect to 100 parts by weight of (a) alkoxy-terminated polydialkylsiloxane, but for example, 1 to 20 parts by weight, preferably It may include 5 to 20 parts by weight, more preferably 5 to 15 parts by weight. By including the above-described weight part (b) polydialkylsiloxane, the surface curing rate of the polysiloxane composition can be further improved, and a cured film with excellent durability can be provided.

The (c) dihydroxy-terminated polydialkylsiloxane (hereinafter, also referred to as 2OH-PDMS) according to an aspect of the present invention may be represented by Chemical Formula 5 below as an example thereof.

[Formula 5]

(In Formula 5,

R ₂₁ to R ₂₆ are each independently (C1-C6)alkyl;

x is a real number from 1 to 2,000.)

According to an aspect of the present invention, R ₂₁ to R ₂₆ may each independently be (C1-C3)alkyl, more preferably methyl, but are not limited thereto. Also, x may be a real number between 10 and 2,000.

More preferably, the (c) dihydroxy-terminated polydialkylsiloxane may be represented by Formula 5-1 below.

[Formula 5-1]

(In Chemical Formula 5-1,

x is a real number from 1 to 2,000.)

In addition, the (c) dihydroxy-terminated polydialkylsiloxane according to one aspect of the present invention may have a viscosity value of 1,000 to 80,000 cps, preferably 5,000 to 30,000 cps measured by a Brookfield viscometer at a temperature of 25 ° C. can be When the above viscosity range is satisfied, workability of the silicone conformal coating composition according to an aspect of the present invention may be further improved, and a curing reaction may be effectively promoted.

In addition, the (c) dihydroxy-terminated polydialkylsiloxane is not limited as long as the object of the present invention is achieved with respect to 100 parts by weight of (a) alkoxy-terminated polydialkylsiloxane, but, for example, 1 to 20 parts by weight part, preferably 5 to 15 parts by weight. By including the above-described weight part (b) polydialkylsiloxane, the surface curing rate of the composition can be more effectively shortened.

The (d) curing catalyst according to an aspect of the present invention may be one or two or more selected from organic tin compounds, organic zinc compounds, organic nickel compounds, zirconium complexes, aluminum complexes, and titanium complexes. The organotin compound may be, for example, dibutyltin octoate, dibutyltin dilaurate, dibutyltin di(2-ethylhexanoate), dioctyltin dilaurate, dioctyltin diacetate, dibutyltin diacetate, organotin compounds such as octyltin dioctoate; organic zinc compounds such as zinc octylate and zinc (II) acetylacetonate; organic nickel compounds such as nickel acetylacetoate and nickel diacetylacetoate; zirconium complexes such as zirconium tetra(acetylacetonate) and zirconium tetrabutylate; Aluminum tris(acetylacetonate), aluminum isopropylate, monosec-butoxyaluminum diisopropylate, aluminum sec-butylate, aluminum ethylate, ethylacetoacetate aluminum diisopropylate, aluminum tris(ethylacetoacetate ), Alkylacetoacetate aluminum diisopropylate, aluminum monoacetylacetonate bis(ethylacetoacetate), aluminum tris(acetylacetonate), aluminum monoisopropoxymonoleoxyethylacetoacetate, cyclic aluminum oxide isopropylate , aluminum complexes such as cyclic aluminum oxide octylate and cyclic aluminum oxide stearate; Diisopropoxybis(acetylacetonate)titanium, diisopropoxybis(triethanolaminate)titanium, di-n-butoxybis(triethanolaminate)titanium, di(2-ethylhexyloxy)bis(2 -Titanium complexes such as ethyl-1,3-hexanediolato)titanium, isopropoxy(2-ethylhexanediolato)titanium, tetraacetylacetonatetitanium, and hydroxybis(lactate)titanium; one selected from; or It may be two or more, but is not limited thereto.

In addition, the (d) curing catalyst may contain 0.05 to 2 parts by weight, preferably 0.05 to 1 part by weight, more preferably 0.1 to 1 part by weight, based on 100 parts by weight of the alkoxy-terminated polydialkylsiloxane (a). there is. As the curing catalyst is included in parts by weight, the condensation reaction of the alkoxy group due to moisture can be further promoted without reducing the stability of the composition.

The (e) photoinitiator according to one aspect of the present invention is, for example, one selected from benzophenone-based compounds, triazine-based compounds, benzoin-based compounds, imidazole-based compounds, xanthone-based compounds, phosphine-based compounds and oxime-based compounds or two or more. More specifically, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, acetophenone, dimethylano acetophenone, 2,2-dimethine Toxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1one, 1-hydroxycyclohexylphenylketone, 2-methyl -1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone , p-phenylbenzophenone, 4,4'-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2- Methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethylketal, acetophenone dimethylketal, p-dimethylaminobenzoic acid One selected from esters, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone] and 2,4,6-tmethylbenzoyl-diphenyl-phosphineoxide Or it may be two or more, but is not limited thereto.

In addition, the (e) photoinitiator may include 0.05 to 1 part by weight, preferably 0.05 to 0.5 parts by weight, and more preferably 0.1 to 0.5 parts by weight based on 100 parts by weight of the alkoxy-terminated polydialkylsiloxane (a). .

The silicone conformal coating composition according to an aspect of the present invention may further include an adhesion imparting agent. The adhesion imparting agent is an alkoxysilane having one or two or more reactive groups selected from an amine group, a thiol group and a hydroxyl group; dialkyldialkoxysilane; alkyltrialkoxysilanes; tetraalkoxysilane; Or it may be selected from a combination thereof.

The adhesion imparting agent is, for example, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-phenyl-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3 -aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and N-2-(aminoethyl)-8-aminooctyltrimethoxysilane, (3-mercaptopropyl )trimethoxysilane, (3-mercaptopropyl)triethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, methyltripropoxysilane, methyltriisopro Poxysilane, methyltributoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, hexyltrimethoxysilane, octadecyltrimethoxysilane, octadecyltriethoxysilane, phenyltrimethoxysilane, phenyltrie It may be one or two or more selected from toxysilane, phenyltriisopropoxysilane, tetramethylorthosilicate, tetraethylorthosilicate, tetrapropylorthosilicate, tetrabutylorthosilicate, and tetrapentyllossosilicate. It is not limited.

In addition, the adhesion imparting agent (a) may include 0.01 to 10 parts by weight, preferably 0.5 to 5 parts by weight based on 100 parts by weight of the alkoxy-terminated polydialkylsiloxane. As the adhesion imparting agent is further included by weight, effects such as shortening of the curing time of the silicone conformal coating composition, improvement of durability of the cured film, and improvement of surface stickiness may be more effectively improved.

The silicone conformal coating composition according to one aspect of the present invention may further include an inorganic filler. The inorganic filler is not particularly limited as long as it is an inorganic filler used in this field, but for example, it may be one or two or more selected from silica, talc, titanium dioxide, aluminum oxide, calcium carbonate, aluminum silicate, magnesium silicate, and zirconium oxide. And, preferably, it may be silica, but is not limited thereto. Specifically, the silica may include precipitated silica or fumed silica, and it may be more preferable to use fumed silica.

In addition, when the inorganic filler is used, its content is not particularly limited as long as it achieves the object of the present invention, but, for example, (a) 1 to 20 parts by weight based on 100 parts by weight of alkoxy-terminated polydialkylsiloxane may include As the inorganic filler is further included in the range of parts by weight, the viscosity and storage stability of the silicone conformal coating composition can be more easily controlled, and the mechanical properties of the cured film formed after curing can be further improved.

In addition, the present invention may further include hexaalkyldisilazane as a reaction promoter. Since the reaction promoter reacts by trapping alcohol, which is a side reactant in the condensate, promotes the overall curing reaction in the forward direction and improves physical properties. It is good that it induces. Preferably, it is preferable to use the same or less than the equivalent of the alkoxy group of the component (a), so the content thereof is not limited. Preferably, it may include 0.5 to 10 parts by weight based on 100 parts by weight of the (a) alkoxy-terminated polydialkylsiloxane. As the reaction promoter is further included in the range of parts by weight, a synergistic effect can be imparted in reducing the surface curing time of the silicone conformal coating composition.

The silicone conformal coating composition according to one aspect of the present invention may be in an anhydrous state, and thus, a curing reaction by moisture may be easily performed under a humidified condition later.

In addition, the silicone conformal coating composition according to one aspect of the present invention may be used as a conformal coating agent, preferably a conformal coating agent for electronic devices.

In addition, one aspect of the present invention provides a cured silicone film obtained by photocuring and moisture curing the silicone conformal coating composition, and an electronic device including the same.

The electronic device is not particularly limited, but may be an electronic device including an electric circuit or an electrode, for example, a resistor, a capacitor, a transistor, a diode, an amplifier, a relay, a transformer, a battery, a fuse, an integrated circuit, a switch, and an LED. , an antenna, and an oscillator.

Of course, any method for producing the cured silicone film according to an aspect of the present invention is possible as long as it is a known method within the range recognized by those skilled in the art.

Hereinafter, a method of forming a cured silicone film using the silicone conformal coating composition will be described in detail.

A silicone cured film according to an aspect of the present invention may include (A) applying the silicone conformal coating composition to a substrate at a relative humidity of 30 to 90%; And (B) photocuring and moisture curing through light irradiation; it can be prepared by a manufacturing method comprising a.

The production of the silicone cured film according to an aspect of the present invention may be characterized in that it is performed at 10 to 50 ° C, preferably 10 to 30 ° C, more preferably 20 to 30 ° C. That is, since the silicone conformal coating composition according to one aspect of the present invention can be cured even at a low temperature such as room temperature and does not require heating during curing, it can be used as a sealant, adhesive or coating agent for electrical and electronic devices. In addition, it is possible to simplify process equipment and manufacturing processes, thereby improving economic feasibility.

In the step (A) according to one aspect of the present invention, a conventional coating method may be used, and one specific example may include a spray method, a roll coater method, a spin coater method, a spin coater method, and the like, but is not limited thereto. In addition, the substrate may use silicon, quartz, glass, silicon wafers, polymers, metals, and metal oxides, but is not limited thereto.

In addition, the relative humidity may be 30 to 90%, preferably 40 to 90%, and more preferably 50 to 80%. Under the above-described humidity conditions, the curing reaction by moisture can proceed more easily.

The light source for photocuring in step (B) according to an aspect of the present invention may be selected from visible light, ultraviolet light, far ultraviolet light, electron beam, X-ray, etc., and in one embodiment, the ultraviolet light is g-ray (wavelength : 436 nm), h-rays, i-rays (wavelength: 365 nm), etc. may be used, and the irradiation amount of these ultraviolet rays may be appropriately selected as needed. More specifically, the light irradiation may be performed using a high-pressure mercury lamp.

Of course, the thickness of the silicone cured film according to one aspect of the present invention may be appropriately changed depending on the purpose, but may be preferably formed to a thickness of 0.1 μm to 2,000 μm, preferably 1 μm to 1,000 μm, and more Preferably, it may be formed to a thickness of 10 μm to 500 μm.

Hereinafter, an embodiment will be described for detailed description of the present invention, but the present invention is not limited to the following embodiment.

[Production Example 1] Production of Room Temperature Moisture Curable PDMS (AK-3M)

A four-necked 3L reactor equipped with a mechanical stirrer, a cooling condenser, a nitrogen injection device, and a thermometer was sufficiently purged with nitrogen gas. After that, 500 g of OH-PDMS (hydroxyl terminated polydimethylsiloxane, YF70C-0.5M) at 5,000 cps, 1,500 g of OH-PDMS (YF70C-2M) at 20,000 cps, and 38.66 g of TMOS (tetramethylorthosilicate) were added and held at 30 ° C for 10 minutes. Mix thoroughly by stirring. 0.38 g of sodium methylate (30% solution in Methanol) was added to the mixture, and the mixture was stirred for 30 minutes while maintaining the temperature of the reactor at 30°C. After taking 10 g of the reaction solution, a tetra-n-butyl titanate (Tyzor TnBT) reaction test was performed to confirm that there was no hydroxyl functional group, and then the reaction was terminated. After completion of the reaction, it was neutralized with 0.11 g of 99% formic acid at room temperature (25 ° C), cooled, and then filtered by high vacuum distillation to remove unreacted substances and filtered through a 200 mesh wire mesh, and room temperature water curing type PDMS with a viscosity of 15,800 cps. A compound, AK-3M, was obtained.

[Production Example 2] Production of Room Temperature Moisture Curable PDMS (AK-M2M)

AK-M2M having a viscosity of 15,700 cps was obtained in the same manner as in Preparation Example 1, except that 27.24 g of methyltrimethoxysilane (MTMS) was used instead of 38.66 g of tetramethylorthosilicate (TMOS).

[Production Example 3] Production of Room Temperature Moisture Curing PDMS (AK-V2M)

AK-V2M having a viscosity of 16,050 cps was obtained in the same manner as in Preparation Example 1, except that 27.24 g of VTMS (Vinyltrimethoxysilane) was used instead of 38.66 g of TMOS.

[Production Example 4] Preparation of UV curable PDMS (MAT-PDMS)

A four-necked 3L reactor equipped with a mechanical stirrer, a cooling condenser, a nitrogen injection device, and a thermometer was sufficiently purged with nitrogen gas. Then, 1,000 g of HT-PDMS (Korea Biogen, RF HD 0080, H content 0.093 mmol/g), 11.1 g of AGE (Allyl gylcidyl ether), 10 g (1 wt%) of platinum catalyst, and 1,000 g of toluene were added. The mixture was stirred at 130 °C for 50 minutes while maintaining a nitrogen atmosphere. FT-IR was measured to confirm that the Si-H peak (2140 cm ^-1 ) disappeared, and the reaction was terminated to obtain ET-PDMS. Thereafter, 8.6 g of MAA (methacrylic acid) was added and reacted at 110 ° C. for 4 hours. Then, unreacted materials and solvents were distilled off under reduced pressure and filtered through a 200 mesh wire mesh to obtain MAT-PDMS having a viscosity of 1,100 cps.

[Production Example 5] Preparation of UV curable PDMS (AT-PDMS)

AT-PDMS having a viscosity of 1,080 cps was obtained in the same manner as in Preparation Example 4, except that 7.2 g of AA (acrylic acid) was used instead of 8.6 g of MAA.

[Example 1]

Preparation of silicone conformal coating composition

After putting 1,955 g of room temperature moisture-curing PDMS (AK-3M PMDS) and 175 g of silicone oil (PDMS Oil, 100 cPs) prepared in Preparation Example 1 into a mixing tank, the tank was mounted on a stirrer and stirred at room temperature (25 ° C) for 30 After stirring for 30 minutes, 250 g of fumed silica (KONASIL, K-P15) was added and further stirred for 30 minutes. After that, 25 g of 3-aminopropyltrimethoxysilane (ATPMS,) and 37.5 g of methyltrimethoxysilane (MTMS) were added as an adhesion imparting agent and stirred for 30 minutes, followed by alcohol scavenger. 50 g of hexamethyldisilazane (HMDZ) and 7.5 g of dibutyltin dilaurate (DBTDL) were added as a curing catalyst and stirred for 30 minutes. Then, 100 g of UV curable PDMS (MAT-PDMS) prepared in Preparation Example 4, 150 g of dihydroxy-terminated PDMS (2OH-PDMS, 15,000 cPs), and 5 g of benzyl dimethyl ketal (BDK) as a photoinitiator were added and stirred for 30 minutes, and then quickly packaged in a prescribed cartridge to obtain the silicone conformal coating composition of Example 1. The physical properties are listed in Table 2 below.

Production of cured silicone film

Under conditions of a relative humidity of 50%, room temperature (25° C.), and a nitrogen atmosphere, the prepared silicone conformal coating composition was coated on a glass substrate to a thickness of 0.2 mm. Then, after light irradiation for 30 seconds with a high-pressure mercury lamp (1 kW, Philips), it was left at room temperature to measure the surface curing time (ASTM C679) and complete curing time, to prepare a silicone cured film.

[Examples 2 to 7]

Except for using the polydimethylsiloxane (PDMS) compound and the photoinitiator content of Examples 2 to 7 described in Table 1, the same procedure as in Example 1 was performed, and the physical properties are listed in Table 2 below.

[Comparative Example 1]

Except for not using UV-curable PDMS (MAT-PDMS), 2OH-PDMS, and photoinitiator (BDK), a room temperature moisture-curable silicone-based composition of Comparative Example 1 was prepared in the same manner as in Example 1, and its physical properties are listed in Table 2 below.

Room temperature moisture curing PDMS UV-curable PDMS 2OH-PDMS photoinitiator Kinds Content (g) Kinds Content (g) Content (g) Content (g) Example 1 AK-3M 1,955 MAT-PDMS 100 100 5 Example 2 AK-3M 1,955 MAT-PDMS 100 200 5 Example 3 AK-3M 1,955 MAT-PDMS 200 100 10 Example 4 AK-3M 1,955 MAT-PDMS 300 100 15 Example 5 AK-3M 1,955 AT-PDMS 300 100 15 Example 6 AK-M2M 1,955 MAT-PDMS 300 100 15 Example 7 AK-V2M 1,955 MAT-PDMS 300 100 15 Comparative Example 1 AK-3M 1,955 - - -

Surface hardening time (min) Complete curing time (h) Example 1 3 20 Example 2 2 18 Example 3 One 12 Example 4 One 5 Example 5 One 5 Example 6 One 5 Example 7 One 3 Comparative Example 1 11 51

As shown in Table 2, it can be seen that the curing time of the silicone conformal coating composition according to the present invention is remarkably shortened. Specifically, even if the conventional moisture-curable silicone-based composition can implement excellent physical properties after curing, the curing speed is slow, and the hardness of the cured film decreases and stickiness occurs on the surface when improving the adhesion with the substrate. There was a limit. However, it can be seen that the composition according to the present invention, compared to Comparative Example 1, can significantly improve the curing speed while securing excellent physical properties of the existing silicone-based cured film.

That is, the silicone conformal coating composition according to the present invention can shorten the process time, reduce costs, improve economic efficiency, and can be easily applied to mass production, and the adhesive strength of the cured film prepared therefrom. and physical properties may be simultaneously satisfied.

Claims (6)

(a) an alkoxy-terminated polydialkylsiloxane having a terminal group represented by Formula 1 below; (b) a polydialkylsiloxane having a terminal group including a (meth)acrylate group and a hydroxyl group; (c) a dihydroxy-terminated polydialkylsiloxane terminated with hydroxyl groups at both ends; (d) a curing catalyst; And (e) a photoinitiator; containing, a silicone conformal coating composition.
[Formula 1]

In Formula 1,
R ₁ is (C1-C10)alkyl or (C2-C10)alkenyl;
R ₂ is (C1-C10)alkyl;
a is an integer of 0 or 1; According to claim 1,
(a) the viscosity of the alkoxy-terminated polydialkylsiloxane is 1,000 to 80,000 cps, (b) the viscosity of the polydialkylsiloxane is 100 to 30,000 cps, and (c) The viscosity of the hydroxy-terminated polydialkylsiloxane is 1,000 to 80,000 cps, the silicone conformal coating composition. According to claim 1,
The (b) (meth) terminal group including an acrylate group and a hydroxyl group is represented by Formula 3 below, the silicone conformal coating composition.
[Formula 3]

In Formula 3,
R ₅ is hydrogen or (C1-C6)alkyl. According to claim 1,
The (b) polydialkylsiloxane is a silicone conformal coating composition represented by Formula 4 below.
[Formula 4]

In Formula 4,
R ₅ is hydrogen or (C1-C6)alkyl;
R ₁₁ to R ₁₆ are each independently (C1-C6)alkyl;
p is a real number from 1 to 2,000. According to claim 1,
The silicone conformal coating composition further comprises an adhesion imparting agent, fumed silica or a combination thereof, the silicone conformal coating composition. A silicone cured film obtained by photocuring and moisture curing the silicone conformal coating composition of any one of claims 1 to 5.