KR20130069051A - Siloxane compound and crosslinkable composition forming an insulating layer comprising the same - Google Patents

Abstract

PURPOSE: A siloxane compound and a crosslinking composition for forming an insulating layer are provided to from an insulating layer with improved heat resitsance and hardness. CONSTITUTION: A siloxane compound is obtained by hydrolytic polymerizing a silane compound represented by chemical formula 1: R^1Si(X^1)3, a silane compound represented by chemical formula 2: R^2Si(X^2)3, and a silane compound represented by chemical formula 3: 3: Si(X^3)4. In the chemical formulas, R^1 is a vinyl group; each of X^1 is independently halogen or C1-5 alkoxy; R^2 is hydrogen; each of X^2 is independently halogen or C1-5 alkoxy; each of X^3 is independently halogen or C1-5 alkoxy group.

Description

Siloxane compound and crosslinkable composition forming an insulating layer comprising the same

The present invention relates to a siloxane compound and a crosslinkable composition for forming an insulating layer including the same, and more particularly, to a siloxane compound and a crosslinkable composition comprising the same, which can be usefully used for forming the insulating layer.

As an insulating layer of an electronic device such as a thin film transistor, an inorganic insulating layer using an inorganic material such as silicon nitride (SiN) is mainly used. The inorganic insulating layer using SiN is formed by chemical vapor deposition, which uses expensive high vacuum equipment.

In order to replace this method, it has been attempted to form an organic insulating layer by a solution process, but since this uses an organic material, heat resistance and transparency may be degraded. In addition, although the organic-inorganic composite insulating layer is formed by the conventional sol-gel method, gas due to thermal decomposition may be generated during the formation of the insulating layer, and the formed insulating layer may not be dense, and thus may have poor moisture permeability.

Therefore, an insulating layer having excellent heat resistance and a dense film without using expensive high vacuum equipment is needed.

Korean Unexamined Patent Publication No. 2007-0046548 Korean Unexamined Patent Publication No. 2007-0098401

The present invention provides a siloxane compound capable of forming a high-density crosslink, and provides a crosslinkable composition for forming an insulating layer having improved heat resistance and hardness by being coated on a substrate and effectively cured, including the siloxane compound.

According to an aspect of the present invention, a siloxane compound obtained by hydrolytic polymerization of a silane compound represented by the following Chemical Formula 1, a silane compound represented by the following Chemical Formula 2 and a silane compound represented by the following Chemical Formula 3 is provided:

≪ Formula 1 >

R ¹ Si (X ¹ ) ₃

In Formula 1, R ¹ is a vinyl group, three X ¹ is independently halogen or C ₁ ~ C ₅ alkoxy group,

<Formula 2>

R ² Si (X ² ) ₃

In Formula 2, R ² is hydrogen, and three X ² are each independently a halogen or a C ₁ to C ₅ alkoxy group,

<Formula 3>

Si (X ³ ) ₄

In the formula 3, 4 X ³ is independently halogen or C ₁ ~ C ₅ alkoxy group each other.

The siloxane compound may include a three-dimensional structure represented by Formula 4 below:

&Lt; Formula 4 >

In Formula 4, l, m, and n satisfy a relationship of 0.2 L ≦ m ≦ 3 L and 0.2 L ≦ n ≦ 3 L, and Y ¹ , Y ² , and Y ³ are each independently halogen, C ₁ to C ₅ alkoxy group, C ₁ -C ₅ hydroxy group or -O-SiH _k (Z) _3-k , wherein 3-k Z are independently of each other halogen, C ₁ -C ₅ alkoxy group, C ₁ -C ₅ Y ¹ , which is a hydroxy group or a siloxane unit, k is an integer of 0 to 3), and is independently from each other a C ₁ -C ₅ alkoxy group, a C ₁ -C ₅ hydroxy group, or -O-SiH _k (Z) _3-k . ^{Two of} Y ² and Y ³ may be condensed with each other to form —O—Si—O—.

In Formulas 1 to 3, the C ₁ to C ₅ alkoxy group may include, for example, at least one of a methoxy group, an ethoxy group, an n-propoxy group, and an iso-propoxy group.

The siloxane compound is obtained by hydrolytic polymerization of the silane compounds in the presence of an acid catalyst on an aqueous reaction medium containing the silane compound represented by Formula 1, the silane compound represented by Formula 2, and the silane compound represented by Formula 3. Can lose.

The siloxane compound is 0.2 to 3 moles based on 1 mole of the silane compound represented by Formula 2, and the silane compound represented by Formula 1, and the silane compound represented by Formula 3 is represented by Formula 2 It can be obtained using 0.2 to 3 moles based on 1 mole of the compound.

The molecular weight of the siloxane compound may be 1,000 to 20,000 in terms of weight average molecular weight in terms of polystyrene measured by gel permeation chromatography.

According to another aspect of the invention, a) the siloxane compound; b) radical initiators; And c) a solvent. A crosslinkable composition for forming an insulating layer is provided.

The radical initiators are benzoyl peroxide, acetyl peroxide, lauyl peroxide, t-butyl peroxide, cumene hydroperoxide, hydrogen peroxide, azobisisobutyronitrile (ABIN) and 1,1'-azobis (cyclohexane Carbonitrile) (ABCN).

The solvent is an aliphatic hydrocarbon solvent such as n-pentane, iso-pentane, hexane, cyclohexane and chloroform; Aromatic hydrocarbon solvents such as benzene, toluene and xylene; Alcohol solvents such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol and t-butanol; Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and acetylacetone; Tetrahydrofuran, 2-methyltetrahydrofuran, ethyl ether, n-propyl ether, iso-propyl ether, iso-propyl ether, bis (2-methoxyethyl) ether, ethylene glycol methyl ether, ethylene glycol ethyl ether and propylene Ether solvents such as glycol methyl ether; At least one of ester solvents such as methyl acetate, ethyl acetate, ethylene glycol methyl ether acetate, and propylene glycol methyl ether acetate may be included.

The content of the solvent may be 50 to 500 parts by weight based on 100 parts by weight of the siloxane compound.

The crosslinkable composition for forming an insulating layer may further include an additive including at least one of an adhesion promoter and a surfactant.

According to another aspect of the invention, the step of applying a crosslinkable composition for forming the insulating layer on a substrate; And curing the applied crosslinking composition for forming an insulating layer.

The temperature of the curing step may range from 200 ℃ to 300 ℃.

According to another aspect of the present invention, an insulating layer formed by the above-described insulating layer forming method is provided.

The siloxane compound according to one embodiment of the present invention may form a high density crosslink.

The crosslinkable composition for forming an insulating layer including a siloxane compound according to an embodiment of the present invention may be applied onto a substrate to effectively cure to form an insulating layer having improved heat resistance and hardness. The crosslinkable composition for forming an insulating layer may be used for forming an insulating layer or a coating layer of an electronic device including a thin film transistor, and it is possible to reduce costs by not using expensive high vacuum equipment such as a conventional chemical vapor deposition method.

The siloxane compound according to an aspect of the present invention is obtained by hydrolyzing and polymerizing a silane compound represented by Formula 1, a silane compound represented by Formula 2, and a silane compound represented by Formula 3:

&Lt; Formula 1 >

R ¹ Si (X ¹ ) ₃

In Formula 1, R ¹ is a vinyl group, three X ¹ is independently halogen or C ₁ ~ C ₅ alkoxy group,

<Formula 2>

R ² Si (X ² ) ₃

In Formula 2, R ² is hydrogen, and three X ² are each independently a halogen or a C ₁ to C ₅ alkoxy group,

<Formula 3>

Si (X ³ ) ₄

In the formula 3, 4 X ³ is independently halogen or C ₁ ~ C ₅ alkoxy group each other.

The siloxane compound is a silane compound represented by Formula 1, a silane compound represented by Formula 2, and a silane compound represented by Formula 1 in a state where a silane compound represented by Formula 1, a silane compound represented by Formula 2, and a silane compound represented by Formula 3 coexist It is obtained by hydrolytic polymerization of the silane compound represented by By hydrolysis polymerization, in the presence of an acid catalyst or a base catalyst and water, after the reaction raw materials (ie, the silane compound represented by the formula (1), the silane compound represented by the formula (2) and the silane compound represented by the formula (3)) are hydrolyzed , Means that the reaction raw materials having a hydroxyl group are polymerized with each other. In the hydrolysis polymerization process, R ² (ie, hydrogen atom) of the silane compound represented by Chemical Formula 2 remains unreacted due to differences in hydrolysis and polymerization reactions depending on the type of catalyst, reaction temperature and time. The remaining hydrogen may partially participate in curing in the process of forming an insulating layer by thermal curing.

The siloxane compound may include a three-dimensional structure represented by Formula 4 below:

&Lt; Formula 4 >

The structure represented by Chemical Formula 4 is a three-dimensional structure in which three kinds of siloxane units are randomly bonded, and l, m, and n satisfy a relationship of 0.2 L ≤ m ≤ 3 L and 0.2 L ≤ n ≤ 3 L. It is selected by value. Preferably, the l, m and n values are selected within the range of 1,000 to 20,0000 in terms of the polystyrene reduced weight average molecular weight measured by gel permeation chromatography of the siloxane compound while satisfying the inequality relationship.

In Formula 4, Y ¹ , Y ² , and Y ³ are each independently a halogen, a C ₁ -C ₅ alkoxy group, a C ₁ -C ₅ hydroxy group, or -O-SiH _k (Z) _3-k . The plurality of Y ¹ , Y ² and Y ³ may be the same as or different from each other. Independently of _one another, ^two of said Y ¹ , Y ² and Y ³ , which are a C ₁ -C ₅ alkoxy group, a C ₁ -C ₅ hydroxy group, or -O-SiH _k (Z) _3-k , condense with each other to form -O-Si -O- may also be formed. Here, 3-k Z are independently of each other a halogen, a C ₁ -C ₅ alkoxy group, a C ₁ -C ₅ hydroxy group, or a siloxane unit, and k is an integer of 0-3. The siloxane unit is defined as a structure represented by -O-SiH _{k '} (Z') _{3-k '} , where k' and z 'are each selected within the same range as k and Z described above.

In Formulas 1 to 3, the halogen may be preferably chlorine. The C ₁ to C ₅ alkoxy group may include, for example, at least one of a methoxy group, an ethoxy group, an n-propoxy group and an iso-propoxy group.

The siloxane compound is a silane compound represented by Formula 1 in the presence of an acid catalyst or a base catalyst on an aqueous reaction medium containing a silane compound represented by Formula 1, a silane compound represented by Formula 2, and a silane compound represented by Formula 3, It can obtain by hydrolyzing-polymerizing the silane compound represented by General formula (2) and the silane compound represented by General formula (3).

As the acid catalyst, for example, at least one of formic acid, hydrochloric acid, nitric acid, sulfuric acid, acetic acid and trifluoroacetic acid can be used. Examples of the base catalyst include alkali metal compounds such as sodium hydroxide and potassium hydroxide; Quaternary ammonium compounds such as tetraalkylammonium hydroxide, tetraalkylammonium silanolate, tetraalkylphosphium hydroxide and tetraalkylphosphium silanolate; At least one of amines such as ammonia and organic amines can be used.

In this hydrolysis polymerization reaction, the hydrolysis reaction and the condensation reaction proceed simultaneously. Acid catalyst under becomes the relatively siloxane compound of a low molecular weight obtained proceeds to the hydrolysis reaction predominantly, a base catalyst under silanolate (SiO ^-) is to to act as a nucleophile to promote the condensation reaction are obtained siloxane compounds of relatively high molecular weight .

Preferably, an acid catalyst is used, and when the acid catalyst is used, a coating solution having a relatively low molecular weight and superior storage stability may be prepared.

When the above Chemical Formulas 1, 2 and 3 are reacted with water under an acid catalyst, each alkoxysilane can be hydrolyzed and polymerized at the same time to obtain a three-dimensional siloxane compound having a relatively small molecular weight of 1,000 to 5,000.

In the hydrolysis polymerization process of the siloxane compound, the amount of the silane compound represented by Formula 1 may be about 0.2 mol to about 3 mol based on 1 mol of the silane compound represented by Formula 2. In order to increase the crosslinking density of the coating film due to the radical reaction, 0.2 mol or more should be used, and when used more than 3 mol, it may cause discoloration due to the use of excessive initiator.

In the hydrolysis polymerization process of the siloxane compound, the amount of the silane compound represented by Formula 3 may be about 0.2 mol to about 3 mol based on 1 mol of the silane compound represented by Formula 2. The use of less than 0.2 moles reduces the hardness and thermal stability, and the use of more than 5 moles may cause cracks in the coating.

The aqueous reaction medium used in the hydrolysis polymerization process of the siloxane compound may include water. The amount of water used is, for example, when the number of moles of the silane compound of Formula 1 used is a, the number of moles of the silane compound of Formula 2 used is b, and the number of moles of the silane compound of Formula 3 used is c, (3a + 3b + 4c) mole may be from about 0.5 times to about 3 times.

The aqueous reaction medium used in the hydrolysis polymerization process of the siloxane compound may further include a first organic solvent. The first organic solvent may be, for example, an aliphatic hydrocarbon solvent such as n-pentane, iso-pentane, hexane, cyclohexane and chloroform; Aromatic hydrocarbon solvents such as benzene, toluene and xylene; Alcohol solvents such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol and t-butanol; Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and acetylacetone; Tetrahydrofuran, 2-methyltetrahydrofuran, ethyl ether, n-propyl ether, iso-propyl ether, iso-propyl ether, bis (2-methoxyethyl) ether, ethylene glycol methyl ether and ethylene glycol ethyl ether Ether solvents; Ester solvents such as methyl acetate, ethyl acetate, ethylene glycol methyl ether acetate and propylene glycol methyl ether acetate.

As the first organic solvent, preferably, a ketone solvent or an ether solvent may be used, which may simultaneously dissolve the siloxane produced by the hydrolysis and condensation reaction and alcohol as a by-product, thereby obtaining a homogeneous solution. The amount of the first organic solvent may be, for example, about 50 to about 500 parts by weight based on 100 parts by weight of the total weight of the silane compound of Formula 1, the silane compound of Formula 2, and the silane compound of Formula 3.

The molecular weight of the siloxane compound may be about 1,000 to about 20,000 in terms of weight average molecular weight in terms of polystyrene measured by gel permeation chromatography. When the molecular weight of the siloxane compound is less than 1,000, cracking may occur due to loss of raw materials and curing shrinkage during thermosetting, and when the molecular weight of the siloxane compound exceeds 20,000, gel may be generated. The surface may show defects such as polymer aggregation.

Crosslinkable composition for forming an insulating layer according to another aspect of the present invention is a) the siloxane compound; b) radical initiators; And c) a solvent.

In the crosslinkable composition for forming the insulating layer, R ¹ (vinyl group) derived from the silane compound of formula (1) is bonded to at least part of Si atoms of the siloxane compound. These vinyl groups serve as reaction sites for crosslinking reactions by radical initiators. In particular, the crosslinking reaction by the condensation reaction of the hydrogen atoms (hydroxy groups) generated during the reaction as well as the crosslinking reaction by the radical initiator is performed together to form a high-density crosslinking. The crosslinking reaction between the siloxane compounds can be effectively carried out, for example, at a temperature of about 200 ° C to about 300 ° C.

The radical initiator may form crosslinks between the siloxane compounds in the crosslinkable composition for forming an insulating layer without the help of a crosslinking agent. In the insulating layer-forming crosslinkable composition, the radical initiator may be stored at room temperature in contact with the siloxane compound. Since the radical initiator forms crosslinks between the siloxane compounds in the crosslinkable composition for forming an insulating layer at a high temperature of 200 to 300 ° C., the crosslinkable composition for forming an insulating layer may be present at room temperature in a state where a radical initiator is included.

The radical initiators are benzoyl peroxide, acetyl peroxide, lauyl peroxide, t-butyl peroxide, cumene hydroperoxide, hydrogen peroxide, azobisisobutyronitrile (ABIN) and 1,1'-azobis (cyclohexane Carbonitrile) (ABCN). As a radical initiator, t-butyl peroxide can be used, for example.

In the insulating layer forming crosslinkable composition, crosslinking occurs by a radical initiator, and vinyl groups of the siloxane compound form a crosslink by a radical initiator at a high temperature, and a reaction site provided by a hydrogen atom bonded to an Si atom is also used for crosslinking formation. Take part.

For example, at a high temperature of 200 ° C to 300 ° C, the vinyl group of the siloxane compound forms a crosslink by the radical initiator, and at the same time, hydrogen atoms bonded to the Si atom also participate in the crosslinking formation. The thermal stability and hardness of the insulating layer is better than the case of participating in the.

The content of the radical initiator in the crosslinkable composition for forming the insulating layer may be, for example, about 0.1 to about 10 parts by weight based on 100 parts by weight of the siloxane compound. If the content of the initiator is less than 0.1 parts by weight, curing is delayed, and if it exceeds 10 parts by weight, discoloration and outgas may be affected.

In the crosslinkable composition for forming the insulating layer, the solvent is a liquid capable of dissolving or dispersing the siloxane compound and the radical initiator. The solvent may serve as a carrier for transporting the siloxane compound and the catalyst when applying the composition.

The solvent may include, for example, water, an organic solvent, or a combination thereof. The organic solvent is, for example, aliphatic hydrocarbon solvents such as n-pentane, iso-pentane, hexane, cyclohexane and chloroform; Aromatic hydrocarbon solvents such as benzene, toluene and xylene; Alcohol solvents such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol and t-butanol; Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and acetylacetone; Tetrahydrofuran, 2-methyltetrahydrofuran, ethyl ether, n-propyl ether, iso-propyl ether, iso-propyl ether, bis (2-methoxyethyl) ether, ethylene glycol methyl ether and ethylene glycol ethyl ether Ether solvents; Ester solvents such as methyl acetate, ethyl acetate, ethylene glycol methyl ether acetate and propylene glycol methyl ether acetate.

Preferably, a homogeneous crosslinkable composition can be obtained and a ketone solvent or an ether solvent can be used in consideration of wettability with a substrate such as a silicon wafer or glass.

The content of the solvent in the crosslinkable composition for forming an insulation layer may be, for example, about 50 to about 500 parts by weight based on 100 parts by weight of the siloxane compound. The organic solvent is used to obtain a homogeneous solution and control of the content of the siloxane compound produced during the hydrolysis polymerization of the alkoxysilane, and the amount of the organic solvent can be appropriately adjusted to obtain the desired coating thickness during spin coating after compounding. have.

The crosslinkable composition for forming an insulating layer may further include an additive such as an adhesion promoter for improving adhesion between the insulating layer and the substrate, a surfactant for reducing the surface tension of the crosslinkable composition for forming the insulating layer, or a combination thereof. Can be. The adhesion promoter is, for example, at least one of glycidoxypropyltrimethoxysilane, glycidoxypropyltriethoxysilane, aminopropyltrimethoxysilane, aminopropyltriethoxysilane, vinyltrimethoxysilane and vinylethoxysilane. It may include one kind. Surfactants include, for example, BYK306 (manufactured by "BYK-chemie"), BYK307 (manufactured by "BYK-chemie"), BYK333 (manufactured by "BYK-chemie"), BYK337 ("polyether modified polydimethylsiloxane"). And BYK341 (manufactured by "BYK-chemie" company).

Insulating layer forming method according to another aspect of the present invention comprises the steps of applying a crosslinkable composition for forming the insulating layer on a substrate; And curing the applied crosslinkable composition for forming an insulating layer.

The substrate may be any substrate with or without a circuit pattern formed on its surface.

Application steps include, for example, spin coating, slit coating, ink-jet printing, gravure printing, gravure offset printing and screen printing (gravure off-set printing). and at least one of screen printing and roll-to-roll printing.

In the curing step, the solvent in the crosslinkable composition for forming the insulating layer is removed. In addition, in the curing step, a crosslinking reaction between the siloxane compounds in the crosslinkable composition for forming an insulating layer proceeds. The crosslinking reaction can for example be based on radical reactions.

The curing step may be a temperature of about 200 to about 300 ℃ due to the presence of the reaction site provided by the vinyl group of the siloxane compound and the presence of unreacted hydroxy groups. For example, curing can be performed effectively at a temperature of 230 ° C.

The insulating layer according to another aspect of the present invention may be formed by the above-described insulating layer forming method.

The insulating layer is formed by curing a crosslinkable composition comprising a siloxane compound capable of forming a high density crosslink, and has improved heat resistance and hardness.

<Examples>

Synthetic example  One --- Siloxane  Preparation of compounds

In a 250 ml three-necked flask equipped with a thermometer and reflux cooler, 22.2 g (0.15 mole) of vinyltrimethoxysilane, 18.3 g (0.15 mole) of trimethoxysilane, 31.1 g (0.15 mole) of tetraethoxysilane and propylene 71 g of glycol methyl ether acetate were added. The reaction mixture was slowly heated to 60 ° C. with vigorous stirring with a magnetic stirring bar. At this temperature, a solution of 1.5 g of formic acid at a concentration of 1 N and 25.5 g of distilled water was slowly added dropwise to the flask for 30 minutes. As a result, an exothermic reaction occurred in the reaction mixture in the flask. The reaction mixture was initially a white cloudy solution, but stirring continued to give a colorless clear solution. After further reaction for 1 hour, the reaction mixture was stored in a refrigerator. The molecular weight of the siloxane compound measured by gel permeation chromatography (Gel Permeation Chromatography) was about 1,800 by weight average molecular weight in terms of polystyrene.

The molecular weight of the sample was obtained using Gel Permeation Chromatography 2414 (Refractive Index Detector) from Waters. Using a tetrahydrofuran as a mobile phase, a calibration curve was prepared using polystyrene having five molecular weights (molecular weight: 1200, 2940, 6180, 16500, 55100) as a standard material, and the sample was flowed at a rate of 1 ml / min while the residence time The weight average molecular weight, number average molecular weight and concentration of the sample were calculated from the detection intensity according to the method.

Example  1 --- preparation of the composition

10 g of the siloxane compound-containing reaction mixture obtained in Synthesis Example 1, 5 g of propylene glycol methyl ether, 0.1 g glycidoxypropyltrimethoxysilane, surfactant BYK 307 (manufactured by "BYK-chemie", polyether modified polydimethylsiloxane) 0.1 g and 0.1 g of di-t-butyl peroxide were mixed and then filtered through a PTFE (polytetrafluoroethylene) filter having an average pore size of 0.1 μm to prepare a crosslinkable composition for forming an insulation layer.

Example  2 --- Insulation layer  formation

The crosslinkable composition for insulating layer formation obtained in Example 1 was dropped on a glass substrate, and then spin-coated for 5 seconds at 500 rpm and 25 seconds at 2000 rpm. The applied composition was heat treated at 120 ° C. for 3 minutes using a hot plate to remove the solvent. The applied composition was then cured by heating in air at 230 ° C. for 30 minutes using a hotplate. The insulating layer thus formed was 4700 mm thick.

Comparative example  One

Into a 250 ml three-necked flask equipped with a thermometer and a reflux condenser, 14.8 g of vinyltrimethoxysilane, 13.6 g of methyltrimethoxysilane, 20.8 g of tetraethoxysilane, and 51.3 g of propylene glycol methyl ether acetate were added. The reaction mixture was heated to 60 ° C. to reflux with vigorous stirring using a stirring magnet. Then, a solution containing 1 g of 1N nitric acid and 17 g of distilled water was slowly added dropwise to the reaction mixture for 30 minutes using a dropping funnel installed in the flask. After further reacting for 3 hours, the reaction mixture was cooled to room temperature and refrigerated.

10 g of the reaction mixture thus obtained, 5 g of propylene glycol methyl ether, 0.1 g of glycidoxypropyltrimethoxysilane, 0.1 g of surfactant BYK 307 and 0.1 g of t-butyl peroxide were mixed, followed by a PTFE filter having an average pore size of 0.1 μm. It filtered through to prepare a crosslinkable composition for forming an insulating layer.

The crosslinkable composition for insulating layer formation thus obtained was dropped on a glass substrate, spin-coated, heated to 120 ° C. using a hot plate to remove the solvent, and then thermally cured at 230 ° C. for 30 minutes in air to form an insulating layer. Formed.

Comparative example  2

Into a 500 ml three-necked flask equipped with a thermometer and a reflux condenser, 32.6 g of vinyltrimethoxysilane, 43.6 g of phenyltrimethoxysilane, 45.8 g of tetraethoxysilane, and 153.8 g of propylene glycol methyl ether acetate were charged. The reaction mixture was heated to reflux while stirring vigorously with a stirring magnet. Then, a solution containing 2.2 g of 1N nitric acid and 37.4 g of distilled water was slowly added dropwise to the reaction mixture for 30 minutes using a dropping funnel installed in the flask. After further reacting for 3 hours, the mixture was cooled to room temperature and stored in a refrigerator.

The crosslinkable composition for insulating layer formation and the insulating layer were formed using the same method as the comparative example 1 except having used the siloxane compound containing reaction mixture obtained in this way.

<Evaluation result>

For the insulating layers formed according to Example 2, Comparative Example 1 and Comparative Example 2, the refractive index, the dielectric constant, V _BD (breakdown voltage), Leakage currnet (J _LC ), thermo-gravimetric analysis (TGA) and surface hardness were measured and the results are summarized in Table 1.

The refractive index was measured at 632.8 nm wavelength using the ST4000-DLX refractometer manufactured by K-MAC.

CV electrical properties were evaluated to determine the dielectric constant. To this end, Au was thermally deposited on each insulating film to prepare a specimen having a metal insulator semiconductor (MIS) structure. CV plots were obtained for the specimens using probes and Agilent's B1500A semiconductor characteristic analyzer. The capacitance measurement value (C _i ), the thickness (d) of the insulating film, and the area (A) of the upper electrode obtained by fixing the frequency at 1 MHz and applying a bias voltage reciprocating from -10 V to 10 V are obtained. ε ₀ = 8.85 x 10 ^-12 F / m) can be substituted into the following equation to obtain the dielectric constant.)

IV electrical characteristics were evaluated to measure breakdown voltage (V _BD ) and leakage current (J _LC ), and Au was thermally deposited on the insulating film formed by the same method as CV electrical characteristics to have MIS (Metal Insulator Semiconductor) structure. Specimen was produced. An IV graph was obtained on the specimen using a probe and Agilent's B1500A semiconductor characterization analyzer. Current density (A / cm ² ) obtained by gradually applying a voltage from 0 V to 100 V in 0.5 V increments, divided by the area of the upper electrode, and withstand voltage (MV / cm) divided by the voltage (d) of the insulating film. ), Respectively. The breakdown voltage when the current density reached 1 µA / cm ² was defined as breakdown voltage V _BD , and the current density when the breakdown voltage was 1 MV / cm was defined as the leakage current J _LC .

TGA (TA Instrument, Inc., Q500) was used to measure the thermal decomposition temperature of 95 wt% at a temperature of 10 ° C./min from room temperature to 600 ° C. under a nitrogen atmosphere.

Surface hardness was obtained by indentation experiments with the following working variables in CSM (continous stiffness measurement) mode using Nanoindenter XP of MTS.

Strain rate 0.05 1 / s, harmonic displacement 2 nm, frequency 45 Hz, maximum indentation depth 500 nm.

The surface hardness of the sample is obtained by dividing the indentation load by the contact area, and the surface hardness of this experiment is the average value at 50-60 nm indentation depth.

division Refractive index Dielectric constant V _BD (MV / cm)
[@ 1㎂ / ㎠] J _LC (A / cm ² )
[@ 1MV / cm] TGA
(℃) Surface hardness
(㎬) Example 2 1.44 5.36 0.46 6.63 × 10 ^-6 450 1.03 Comparative Example 1 1.44 4.72 1.05 7.84 × 10 ^-7 357 0.39 Comparative Example 2 1.52 4.65 1.06 1.15 × 10 ^-7 362 0.18

Referring to Table 1, the refractive index of the coating film increases as it contains a phenyl group, and the difference between the methyl group and the hydro group was found to be insignificant. In addition, in view of the dielectric constants, V _BD and J _LC values of the insulating layer of Example 2, it can be seen that the insulating layer of Example 2 exhibits very good electrical insulation property to be used as an insulating layer or a coating layer of an electronic device. have.

Of particular note, the TGA value of Example 2 was 450 ° C., which was significantly increased compared to the TGA values of 357 ° C. and 362 ° C. of the insulating layers of Comparative Examples 1 and 2 thermoset at high temperatures. In addition, the surface hardness of Example 2 is 1.03, which indicates that the surface hardness of the insulating layers of Comparative Examples 1 and 2 thermoset at the same temperature is significantly increased compared to 0.39 GPa and 0.18 GPa. Therefore, in view of the TGA and the surface hardness of Example 2, it can be seen that the insulating layer of Example 2 was more effectively crosslinked than Comparative Examples 1 and 2.

The siloxane compound in the crosslinkable composition for forming an insulation layer used to form the insulation layers of Comparative Examples 1 and 2 is prepared without using the silane compound of formula (2) containing a hydrogen atom bonded to Si. In contrast, the siloxane compound in the crosslinkable composition for forming an insulation layer used in the formation of the insulation layer of Example 2 is prepared using a silane compound of formula (2) containing a hydrogen atom bonded to Si.

Due to these differences, it is assumed that the insulating layer of Example 2 exhibited significantly improved heat resistance and hardness by crosslinking the siloxane compound very effectively.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

Claims (14)

The siloxane compound obtained by hydrolytic polymerization of the silane compound represented by the following formula (1), the silane compound represented by the following formula (2) and the silane compound represented by the following formula (3):
&Lt; Formula 1 >
R ¹ Si (X ¹ ) ₃
In Formula 1, R ¹ is a vinyl group, three X ¹ is independently halogen or C ₁ ~ C ₅ alkoxy group,
(2)
R ² Si (X ² ) ₃
In Formula 2, R ² is hydrogen, and three X ² are each independently a halogen or a C ₁ to C ₅ alkoxy group,
(3)
Si (X ³ ) ₄
In the formula 3, 4 X ³ is independently halogen or C ₁ ~ C ₅ alkoxy group each other. The method of claim 1,
Siloxane compound comprising a three-dimensional structure represented by the following formula (4):
&Lt; Formula 4 >

In Formula 4,
l, m and n satisfy the relationship of 0.2 L ≤ m ≤ 3 L and 0.2 L ≤ n ≤ 3 L,
Y ¹ , Y ² , and Y ³ independently of one another are halogen, C ₁ -C ₅ alkoxy group, C ₁ -C ₅ hydroxy group or -O-SiH _k (Z) _3-k (where 3-k Z are Independently of one another are halogen, a C ₁ to C ₅ alkoxy group, a C ₁ to C ₅ hydroxy group or a siloxane unit, k is an integer from 0 to 3),
Independently of _one another, ^two of said Y ¹ , Y ² and Y ³ , which are a C ₁ -C ₅ alkoxy group, a C ₁ -C ₅ hydroxy group, or -O-SiH _k (Z) _3-k , condense with each other to form -O-Si -O- can be formed. The method of claim 1,
The C ₁ -C ₅ alkoxy group comprises at least one of a methoxy group, an ethoxy group, n-propoxy group and iso-propoxy group. The method of claim 1,
A siloxane compound obtained by hydrolysis polymerization of the silane compound represented by Formula 1, the silane compound represented by Formula 2, and the silane compound represented by Formula 3 in the presence of an acid catalyst on an aqueous reaction medium. The method of claim 1,
0.2 mol to 3 mol of the silane compound represented by Chemical Formula 1 is used based on 1 mol of the silane compound represented by Chemical Formula 2, and 1 mol of the silane compound represented by Chemical Formula 2 is used as the silane compound represented by Chemical Formula 3. The siloxane compound obtained using 0.2 mol-3 mol as a reference. The method of claim 1,
The siloxane compound whose molecular weight of the said siloxane compound is 1,000-20,000 in the weight average molecular weight of polystyrene conversion measured by the gel permeation chromatography. a) a siloxane compound according to any one of claims 1 to 6;
b) radical initiators; And
c) solvents;
Crosslinkable composition for forming an insulating layer comprising a. The method of claim 7, wherein
The radical initiators are benzoyl peroxide, acetyl peroxide, lauyl peroxide, t-butyl peroxide, cumene hydroperoxide, hydrogen peroxide, azobisisobutyronitrile (ABIN) and 1,1'-azobis (cyclohexane Carbonyl nitrile) (ABCN) comprising at least one cross-linkable composition for forming an insulating layer. The method of claim 7, wherein
The solvent is an aliphatic hydrocarbon solvent such as n-pentane, iso-pentane, hexane, cyclohexane and chloroform; Aromatic hydrocarbon solvents such as benzene, toluene and xylene; Alcohol solvents such as methanol, ethanol, n-propanol, iso-propanol, n-butanol, iso-butanol, sec-butanol and t-butanol; Ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, and acetylacetone; Tetrahydrofuran, 2-methyltetrahydrofuran, ethyl ether, n-propyl ether, iso-propyl ether, iso-propyl ether, bis (2-methoxyethyl) ether, ethylene glycol methyl ether, ethylene glycol ethyl ether and propylene Ether solvents such as glycol methyl ether; A crosslinkable composition for forming an insulation layer comprising at least one of ester solvents such as methyl acetate, ethyl acetate, ethylene glycol methyl ether acetate, and propylene glycol methyl ether acetate. The method of claim 7, wherein
The content of the solvent is 50 to 500 parts by weight based on 100 parts by weight of the siloxane compound crosslinkable composition for forming an insulating layer. The method of claim 7, wherein
A crosslinkable composition for forming an insulation layer further comprising an additive including at least one of an adhesion promoter and a surfactant. Applying a crosslinkable composition for forming an insulating layer according to claim 7 on a substrate; And
Curing the coated crosslinkable composition for forming an insulating layer;
Insulation layer forming method comprising a. The method of claim 12,
Method for forming an insulating layer of the curing step is a temperature of 200 ℃ to 300 ℃. An insulating layer formed by the insulating layer forming method according to claim 12.