Silicone-based resin composition and method of preparing the same

Abstract

Provided is a method of preparing a silicone-based resin composition, the method including: preparing a first polyorganosiloxane by reacting a first alkoxy silane with a second alkoxy silane; preparing a second polyorganosiloxane by modifying an alkoxy group included in the first polyorganosiloxane into a hydroxy group; and preparing a third polyorganosiloxane by modifying the hydroxy group included in the second polyorganosiloxane into a siloxane group.

Description

[0001] Wal2440S

[0002] SILICONE-BASED RESIN COMPOSITION AND METHOD OF PREPARING THE SAME

[0003] [Technical Field]

[0004] The present invention relates to a silicone-based resin and a method of preparing the same.

[0005] [Background Art]

[0006] Silicone resins are known to have excellent heat and cold resistance, electrical insulation, weather resistance, water repellency and transparency, and are widely used in various fields such as electrical and electronic devices, OA devices, automobiles, and building materials. For example, Patent Document 1 (Korean Patent No. 1763464) discloses a method of preparing a polyorganosiloxane using difunctional and trifunctional silanes; and a method of preparing a coating composition including the polyorganosiloxane-containing.

[0007] However, a polyorganosiloxane synthesized by the preparation method contains an alkoxy group. When the polyorganosiloxane composition contains a lot of alkoxy groups, the stability is lowered, so that the properties of the resin composition are adversely affected during long-term storage.

[0008] [Disclosure]

[0009] [Technical Problem]

[0010] Therefore, the present invention has been made in view of the above problems, and it is one object of the present invention to provide a silicone-based resin composition having improved reaction stability and long-term storage stability.

[0011] [Technical Solution]

[0012] In accordance with an aspect of the present invention, the above and other objects can be accomplished by the provision of a method of preparing a silicone-based resin composition, the method including: preparing a first polyorganosiloxane by reacting a first alkoxy silane with a second alkoxy silane; preparing a second polyorganosiloxane by Wal2440S

[0013] modifying an alkoxy group included in the first polyorganosiloxane into a hydroxy group; and preparing a third polyorganosiloxane by modifying a hydroxy group included in the second polyorganosiloxane into a siloxane group.

[0014] In an embodiment, in the preparing of the first polyorganosiloxane, the first alkoxy silane, the second alkoxy silane and a hydrogenated siloxane may be reacted.

[0015] In an embodiment, the first alkoxy silane may be represented by Chemical Formula 1 below:

[0016] [Chemical Formula 1]

[0017] SiRJxR x

[0018] where R1is at least one selected from the group consisting of hydrogen, a substituted or unsubstituted aryl group, and a substituted or unsubstituted alkyl group, R2is a substituted or unsubstituted alkoxy group, and x is an integer from 1 to 3.

[0019] In an embodiment, the second alkoxy silane may be represented by Chemical Formula 2 below:

[0020] [Chemical Formula 2]

[0021] SiR3yR44-y

[0022] where R3is at least one selected from the group consisting of hydrogen, a substituted or unsubstituted aryl group, and a substituted or unsubstituted alkyl group, R4is a substituted or unsubstituted alkoxy group, and y is an integer from 1 to 3.

[0023] In an embodiment, the hydrogenated siloxane may be represented by Chemical Formula 3 below:

[0024] [Chemical Formula 3]

[0025] SixR5yHzOw

[0026] where R5is at least one selected from the group consisting of a substituted or unsubstituted aryl group and a substituted or unsubstituted alkyl group, x is an integer from 2 to 10, y is an integer from 2 to 20, z is an integer from 2 to 10, and w is an integer from 1 to 5.

[0027] In an embodiment, the preparing of the second polyorganosiloxane may include reacting by adding a strong acid to the first polyorganosiloxane.

[0028] In an embodiment, the preparing of the third polyorganosiloxane may include reacting by adding silazane to the second polyorganosiloxane.

[0029] In an embodiment, an alkoxy group ratio in the third polyorganosiloxane may be less than 0.005, wherein the alkoxy group ratio is a value obtained by dividing an area of a peak Wal2440S

[0030] derived from an alkoxy group by an area of all peaks, in nuclear magnetic resonance of the third polyorganosiloxane.

[0031] In accordance with another aspect of the present invention, there is provided a silicone-based resin composition, including a polyorganosiloxane represented by average Compositional Formula 5 below, wherein an alkoxy group ratio in the polyorganosiloxane is less than 0.005, wherein the alkoxy group ratio is a value obtained by dividing an area of a peak derived from an alkoxy group by an area of all peaks, in nuclear magnetic resonance of the polyorganosiloxane,

[0032] [Compositional Formula 5]

[0033] RJaSiO (4-a) / 2

[0034] where R1denotes one or more groups selected from the group consisting of a hydrogen atom, a hydroxyl group, and a saturated or unsaturated monovalent hydrocarbon group having 1 to 18 carbon atoms, and a is 0 to 3.5.

[0035] In accordance with yet another aspect of the present invention, there is provided a silicone-based resin composition, including a polyorganosiloxane represented by average Compositional Formula 5 below, wherein the silicone-based resin composition has a viscosity increase rate of less than 0.07 measured by Measurement method below,

[0036] [Compositional Formula 5]

[0037] R^SiO (4-a) / 2

[0038] where R1denotes one or more groups selected from the group consisting of a hydrogen atom, a hydroxyl group, and a saturated or unsaturated monovalent hydrocarbon group having 1 to 18 carbon atoms, and a is 0 to 3.5,

[0039] [Measurement method]

[0040] the silicone-based resin composition is allowed to stand at 105°C for 72 hours, and the viscosity increase rate is a value obtained by dividing a difference between a viscosity of the silicone-based resin composition after being allowed to stand and an initial viscosity of the silicone-based resin composition by the initial viscosity of the silicone-based resin composition.

[0041] In an embodiment, R1may be at least one selected from the group consisting of a hydrogen atom, a hydroxy group, an alkyl group and an aryl group.

[0042] In an embodiment, the polyorganosiloxane may be represented by Chemical Formula 6 below:

[0043] [Chemical Formula 6] Wal2440S

[0044]

[0045] where R6is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, R7is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, R8is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, m is 1 to 1500, n 1 to 2000, and k is 1 to 1000.

[0046] [Advantageous effects]

[0047] A method of preparing a silicone-based resin composition according to an embodiment includes a step of modifying an alkoxy group into a hydroxy group and a step of modifying a hydroxy group into a siloxane group. The method of preparing a silicone-based resin composition according to an embodiment can prepare a first organic polysiloxane by reacting a first alkoxy silane with a second alkoxy silane and can modify an alkoxy group included in the first organic polysiloxane into a siloxane group.

[0048] Accordingly, a silicone-based resin composition according to an embodiment can include an alkoxy group in a very low content or can exclude the alkoxy group.

[0049] Accordingly, the silicone-based resin composition according to an embodiment can have consistent reactivity. That is, since the silicone-based resin composition according to an embodiment hardly contains an alkoxy group that may affect a reaction rate, a reaction rate variation can be reduced.

[0050] In addition, since that silicone-based resin composition according to an embodiment hardly contains an alkoxy group, constant properties can be maintained even if stored for a long time. In particular, since the silicone-based resin composition according to an embodiment has the aforementioned viscosity increase rate, storage stability can be improved.

[0051] [Description of Drawings]

[0052] FIG. 1 illustrates a process of preparing a silicone-based resin composition according to an embodiment. Wal2440S

[0053] FIG. 2 illustrates 'H-NMR of a first organic polysiloxane according to a comparative example.

[0054] FIG.3 illustrates 'H-NMR of a third organic polysiloxane according to an example.

[0055] [Best Mode]

[0056] Hereinafter, the present invention will be described in more detail with reference to the following embodiments. The scope of the present invention is not limited to the following embodiments and covers modifications of the technical spirit substantially equivalent thereto.

[0057] In the specification, when a certain part “includes” a certain component, this indicates that the part may further include another component instead of excluding another component unless there is no different disclosure. In addition, it should be understood that all numerical ranges representing physical property values, dimensions, etc. of components described in this specification are modified by the term 'about' in all cases unless otherwise specified.

[0058] FIG. 1 illustrates a process of preparing a silicone-based resin composition according to an embodiment. FIG. 2 illustrates 'H-NMR of a first organic polysiloxane according to a comparative example. FIG.3 illustrates 'H-NMR of a third organic polysiloxane according to an example.

[0059] Referring to FIG. 1, a method of preparing a silicone-based resin composition according to an embodiment includes a step (S10) of preparing a first polyorganosiloxane, a step (S20) of preparing a second polyorganosiloxane by modifying the first polyorganosiloxane and a step (S30) of preparing a third polyorganosiloxane by modifying the second polyorganosiloxane.

[0060] The method of preparing a silicone-based resin composition according to an embodiment includes a step of preparing a first polyorganosiloxane by reacting a first alkoxy silane with a second alkoxy silane; a step of preparing a second polyorganosiloxane by modifying an alkoxy group included in the first polyorganosiloxane into a hydroxy group; and a step of preparing a third polyorganosiloxane by modifying a hydroxy group included in the second polyorganosiloxane into a siloxane group.

[0061] The first polyorganosiloxane may be formed by reacting the first alkoxy silane with the second alkoxy silane. The first polyorganosiloxane may be prepared by condensationreacting the first alkoxy silane with the second alkoxy silane. Wal2440S

[0062] The first alkoxy silane may be represented by Chemical Formula 1 below:

[0063] [Chemical Formula 1]

[0064] SiRJxR x

[0065] In Chemical Formula 1, R1is at least one selected from the group consisting of hydrogen, a substituted or unsubstituted aryl group, and a substituted or unsubstituted alkyl group, R2is a substituted or unsubstituted alkoxy group, and x is an integer from 1 to 3.

[0066] In Chemical Formula 1, R1may be a substituted or unsubstituted aryl group, and R2may be a substituted or unsubstituted alkoxy group.

[0067] In Chemical Formula 1, R1may be a substituted or unsubstituted aryl group, and R2may be a substituted or unsubstituted alkoxy group.

[0068] In Chemical Formula 1, R1may be a phenyl group or a naphthalene group, and R2may be a methoxy group or an ethoxy group.

[0069] In Chemical Formula 1, R1may be a phenyl group, R2may be an ethoxy group, and x may be 1.

[0070] The second alkoxy silane may be represented by Chemical Formula 2 below:

[0071] [Chemical Formula 2]

[0072] SiR3yR44-y

[0073] In Chemical Formula 2, R3is at least one selected from the group consisting of hydrogen, a substituted or unsubstituted aryl group, and a substituted or unsubstituted alkyl group, R4is a substituted or unsubstituted alkoxy group, and y is an integer from 1 to 3.

[0074] In Chemical Formula 2, R3may be a substituted or unsubstituted alkyl group, and R4may be a substituted or unsubstituted alkoxy group.

[0075] In Chemical Formula 2, R3may be at least one selected from a methyl group and an ethyl group, and R4may be at least one selected from a methoxy group and an ethoxy group.

[0076] In Chemical Formula 2, R3may be at least one selected from a methyl group and an ethyl group, and R4may be at least one selected from a methoxy group and an ethoxy group.

[0077] In Chemical Formula 2, R3may be a methyl group, R4may be an ethoxy group, and y may be 1.

[0078] The step of preparing the first polyorganosiloxane may include a step of reacting the first alkoxy silane, the second alkoxy silane and a hydrogenated siloxane. That is, the first polyorganosiloxane may be prepared through a reaction between the first alkoxy silane, the second alkoxy silane and the hydrogenated siloxane.

[0079] The hydrogenated siloxane may be represented by Chemical Formula 3 below. Wal2440S

[0080] [Chemical Formula 3]

[0081] SixR5yHzOw

[0082] In Chemical Formula 3, R5is at least one selected from the group consisting of a substituted or unsubstituted aryl group and a substituted or unsubstituted alkyl group, x is an integer from 2 to 10, y is an integer from 2 to 20, z is an integer from 2 to 10, and w is an integer from 1 to 5.

[0083] In Chemical Formula 3, R5may be at least one selected from the group consisting of a substituted or unsubstituted aryl group having 6 to 20 carbon atoms and a substituted or unsubstituted alkyl group having 1 to 18 carbon atoms.

[0084] In Chemical Formula 3, R5may be at least one selected from a phenyl group, a naphthalene group, a methyl group, and an ethyl group.

[0085] In Chemical Formula 3, R5may be at least one selected from a methyl group and an ethyl group.

[0086] In Chemical Formula 3, R5may be a methyl group, x may be 2, y may be 4, z may be 2, and w may be 1.

[0087] In Chemical Formula, 1, 2 or 3, R1, R2, R3, R4and R5may be each independently an alkyl group having 1 to 6 carbon atoms, a phenyl group, a hydroxy group, a halogen, an aryl group having 6 to 20 carbon atoms or an alkoxy group having 1 to 3 carbon atoms. Here, the alkyl group having 1 to 6 carbon atoms may be a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, a pentyl group or a hexyl group and may be substituted with a halogen group. The alkoxy group having 1 to 3 carbon atoms may be a methoxy group, an ethoxy group or a propoxy group and may be substituted with a halogen group. The halogen group may be fluorine (F), chlorine (Cl), bromine (Br) or iodine (I).

[0088] The first and second alkoxysilanes may be each independently at least one selected from, methyltrimethoxysilane, triethoxymethylsilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diethyldimethoxysilane, diethyldiethoxysilane, dipropyldimethoxysilane, dipropyldiethoxysilane, dibuyldimethoxysilane, dibuyldiethoxysilane, dipentyldimethoxysilane, dipentyldiethoxysilane, dihexyldimethoxysilane, dihexyldi ethoxysilane, phenyltrimethoxysilane,

[0089] phenyltri ethoxysilane, phenylmethyldimethoxysilane, phenylmethyldi ethoxysilane, phenylmethyldipropoxysilane, phenylethyldimethoxysilane and

[0090] pheny Ipropy 1 dimethoxy sil ane .

[0091] The hydrogenated siloxane may be, for example, 1,1,3,3-tetramethyldisiloxane, 1,3- Wal2440S

[0092] dimethyl-l,3-diphenyltetramethyldisiloxane, l,l-dimethyl-3,3-diphenyltetramethyldisiloxane, 1.1.3.3-tetraphenyldisiloxane, pentamethyldisiloxane, methyltetramethyldisiloxane, 1,1-dimethyl- 1 ,3 ,3 -triphenyldisiloxane, 1 , 1 -dimethyl- 1 ,3 ,3 -triphenyldisiloxane, 1 , 1 -dimethyl- 1.3.3-triphenyldisiloxane, l,l,l-trimethyl-3,3-diphenyldisiloxane, l,l,l-trimethyl-3,3-diphenyldisiloxane, l,3,3-trimethyl-l,l-diphenyldisiloxane, tetramethylphenyldisiloxane) or the like, without being limited thereto.

[0093] The first alkoxysilane, the second alkoxysilane and the hydrogenated siloxane may be fed into a reactor and a first condensation reaction may proceed as shown in Reaction Scheme 1 below under acidic and basic conditions:

[0094] [Reaction Scheme 1]

[0095] Acid + Base

[0096] First alkoxysilane + Second alkoxysilane + Hydrogenated siloxane - ► First polyorganosiloxane In the condensation reaction, an acid may be introduced, and then a base may be introduced.

[0097] In addition, in the condensation reaction, ethanol or methanol may be produced as a by-product

[0098] The acid used in the condensation reaction may be at least one selected from the group consisting of hydrochloric acid, nitric acid and sulfuric acid.

[0099] The base used in the condensation reaction may be at least one selected from the group consisting of ammonia, sodium hydroxide, potassium hydroxide, calcium hydroxide and magnesium hydroxide.

[0100] The condensation reaction may proceed at about 60°C to about 100°C.

[0101] The condensation reaction may proceed over several steps. First, the first alkoxy silane, the second alkoxy silane, and the hydrogenated siloxane may be fed into a reactor, the acid may be added thereto, and a first reaction may proceed. Next, the base may be added to the first reactant, and a second reaction may proceed. In addition, the acid may be added to the second reactant, and a third reaction may proceed.

[0102] The condensation reaction may proceed for about 4 hours to about 10 hours. The first reaction may proceed for about 2 hours to about 5 hours. The second reaction may proceed for about 2 hours to about 5 hours.

[0103] In addition, the condensation reaction may proceed in an aqueous solution. That is, the condensation reaction may proceed in a mixture including the reactant and the water.

[0104] In the condensation reaction, a molar ratio of the first alkoxy silane to the second Wal2440S

[0105] alkoxy silane may be about 1 : 1 to about 1 :4. In addition, in the condensation reaction, a molar ratio of the first alkoxy silane to the hydrogenated siloxane may be about 1 :0.3 to about 1 : 1.5.

[0106] The acid may be added to the mixture in a content of about 0.04 parts by weight to about 0.4 parts by weight based on 100 parts by weight of the mixture including the reactant and the water.

[0107] The base may be added to the mixture in a content of about 0.04 parts by weight to about 0.4 parts by weight based on 100 parts by weight of the mixture including the reactant and the water.

[0108] After the condensation reaction is completed, the first polyorganosiloxane may be extracted and purified with an organic solvent such as toluene.

[0109] The first polyorganosiloxane may be modified by a first modification reaction to prepare a second polyorganosiloxane. In the first modification reaction, an alkoxy group included in the first polyorganosiloxane may be modified into a hydroxy group.

[0110] The first modification reaction may proceed as shown in Reaction Scheme 2 below:

[0111] [Reaction Scheme 2]

[0112] Strong acid

[0113] First polyorganosiloxane - ► Second polyorganosiloxane

[0114] In the first modification reaction, a strong acid may be used. The strong acid used in the first modification reaction may be, for example, hydrochloric acid (HC1), nitric acid (HNO3), phosphoric acid (H3PO4), sulfuric acid (H2SO4), boric acid (H3BO3), hydrofluoric acid (HF), hydrobromic acid (HBR) or the like, without being limited thereto.

[0115] The first modification reaction may proceed at about 60°C to about 110°C. The first modification reaction may proceed for about 1 hours to about 4 hours. In addition, the first modification reaction may proceed by adding the first polyorganosiloxane and water to an organic solvent such as acetonitrile. The strong acid may be added to the first polyorganosiloxane in a content of about 0.04 parts by weight to about 0.1 parts by weight based on 100 parts by weight of the first polyorganosiloxane.

[0116] After the first modification reaction is completed, the second polyorganosiloxane may be extracted with an organic solvent such as toluene.

[0117] The second polyorganosiloxane may be modified by a second modification reaction Wal2440S

[0118] to prepare a third polyorganosiloxane. In the second modification reaction, a hydroxy group contained in the second polyorganosiloxane may be modified into a siloxane group.

[0119] The second polyorganosiloxane may be reacted with silazane to prepare the third polyorganosiloxane.

[0120] The silazane may be represented by Chemical Formula 4 below:

[0121] [Chemical Formula 4]

[0122] SixR5yHzNw

[0123] where R5is at least one selected from the group consisting of a substituted or unsubstituted aryl group and a substituted or unsubstituted alkyl group, x is an integer from 2 to 10, y is an integer from 4 to 20, z is an integer from 1 to 5, and w is an integer from 1 to 5.

[0124] The silazane used in the second modification reaction may be, for example, hexamethyldisilazane, hexaphenyldisilazane, methylpentylphenyldisilazane, 1,1-dimethyl- 1.3.3.3-tetraphenyldisilazane, l,3-dimethyl-l,l,3,3-tetraphenyldisilazane, 3,3-dimethyl- 1.1.1.3-tetraphenyldisilazane, l,l,l-trimethyl-3,3,3-triphenyldisilazane, l,l,3-trimethyl-l,3,3-triphenyldisilazane, l,3,3-trimethyl-l,l,3-triphenyldisilazane, l,3,3-trimethyl-l,l,3-triphenyldisilazane, 1 , 1 , 1 , 1 -tetramethyl-3 ,3 -diphenyldi silazane, 1,1, 1 ,3 -tetramethyl- 1,3-diphenyldisilazane, l,l,3,3-tetramethyl-3,3-diphenyldisilazane, 1,1,1,1,3-pentylmethyl-l-phenyl di silazane, 1,1,1, 1 ,3 -pentyl methyl -3 -phenyl di silazane, 1,1,1, 1 ,3 -pentyl methyl -3 -phenyldisilazane, l,l,l,l,3-pentylmethyl-3-phenyldisilazane or the like, without being limited thereto.

[0125] The second modification reaction may proceed as shown in Reaction Scheme 3 below:

[0126] [Reaction Scheme 3]

[0127] Silazane

[0128] Second polyorganosiloxane - ► Third polyorganosiloxane

[0129] The second modification reaction may proceed at about 60°C to about 110°C. The second modification reaction may proceed for about 1 hours to about 4 hours.

[0130] In the second modification reaction, the silazane may be added to the second polyorganosiloxane in a content of about 5 parts by weight to about 35 parts by weight based on 100 parts by weight of the second polyorganosiloxane.

[0131] Accordingly, the second polyorganosiloxane is modified, and the third Wal2440S

[0132] polyorganosiloxane is synthesized. That is, a silicone-based resin composition including the third polyorganosiloxane is prepared.

[0133] A silicone-based resin composition according to an embodiment may include the third polyorganosiloxane as a main component. A silicone-based resin composition according to an embodiment may include the third polyorganosiloxane. A silicone-based resin composition according to an embodiment may include the third polyorganosiloxane and a solvent.

[0134] The silicone-based resin composition according to an embodiment may include the third polyorganosiloxane in a content of about 95 wt% or more based on a weight excluding a solvent. The silicone-based resin composition according to an embodiment may include the third polyorganosiloxane in a content of about 97 wt% or more based on a weight excluding a solvent. The silicone-based resin composition according to an embodiment may include the third polyorganosiloxane in a content of about 99 wt% or more based on a weight excluding a solvent.

[0135] The third polyorganosiloxane may be represented by Compositional Formula 5 below:

[0136] [Compositional Formula 5]

[0137] RJaSiO (4-a) / 2

[0138] In Compositional Formula 5, R1may denote one or more groups selected from the group consisting of a hydrogen atom, a hydroxyl group, and a saturated or unsaturated monovalent hydrocarbon group having 1 to 18 carbon atoms, and a may be 0 to 3.5. a may be 1 to 2.8.

[0139] In Compositional Formula 5, R1may be at least one selected from the group consisting of a hydrogen atom, a hydroxy group, an alkyl group having 1 to 18 carbon atoms and an aryl group having 6 to 18 carbon atoms.

[0140] In Compositional Formula 5, R1may be at least one selected from the group consisting of a hydrogen atom, a hydroxy group, a methyl group and a phenyl group.

[0141] The third polyorganosiloxane may be represented by Chemical Formula 6 below: [Chemical Formula 6] Wal2440S

[0142]

[0143] In Chemical Formula 6, R6is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, R7is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, and R8is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms.

[0144] In addition, m may be 1 to 1500, n may be 1 to 2000, and k may be 1 to 1000.

[0145] In Chemical Formula 6, R6may be a phenyl group, R7may be a methyl group or an ethyl group, and R8may be a hydrogen atom.

[0146] The third polyorganosiloxane may have a weight average molecular weight of about 3000 g / mol to about 4000 g / mol.

[0147] The third polyorganosiloxane may have a viscosity of about 700 cPS to about 3000 cPS.

[0148] In the silicone-based resin composition according to an embodiment, an alkoxy ratio may be defined. The alkoxy ratio may be a value obtained by dividing the area of a peak derived from an alkoxy group by the area of all peaks, in nuclear magnetic resonance of the third polyorganosiloxane. That is, for the third polyorganosiloxane, 'H-NMR is measured, and it may be a ratio of the area of a hydrogen peak included in an alkoxy group to the area of all hydrogen peaks.

[0149] The alkoxy ratio may be represented by Equation 1 below:

[0150] [Equation 1]

[0151] Alkoxy ratio = Area of alkoxy peak / Area of all peaks

[0152] As shown in 'H-NMR of FIG. 2, a peak derived from a methoxy group may be located at about 3.3 ppm to about 3.7 ppm, and a peak derived from an ethoxy group may be located at about 1 ppm to about 1.4 ppm and about 3.7 ppm to about 3.9 ppm.

[0153] In the silicone-based resin composition according to an embodiment, the alkoxy ratio may be less than 0.05. In the silicone-based resin composition according to an embodiment, the alkoxy ratio may be less than 0.03. In the silicone-based resin composition according to Wal2440S

[0154] an embodiment, the alkoxy ratio may be less than 0.01. In the silicone-based resin composition according to an embodiment, the alkoxy ratio may be less than 0.005. In the silicone-based resin composition according to an embodiment, the alkoxy ratio may be less than 0.001.

[0155] In addition, in the silicone-based resin composition according to an embodiment, a viscosity increase rate may be defined.

[0156] The viscosity increase rate may be a value obtained by dividing a viscosity increase when the silicone-based resin composition according to an embodiment is allowed to stand at a certain temperature for a certain time by an initial viscosity.

[0157] The temperature when allowed to stand may be any one selected from among about 95°C, about 105°C, about 120°C and about 130°C. In addition, the time for which it is allowed to stand may be any one selected from among about 48 hours, about 72 hours, about 96 hours and about 120 hours.

[0158] The viscosity increase denotes a difference between a viscosity after standing the silicone-based resin composition according to an embodiment and an initial viscosity thereof.

[0159] The viscosity increase rate of the silicone-based resin composition according to an embodiment may be measured by the following measurement method:

[0160] [Measurement method]

[0161] the silicone-based resin composition is allowed to stand at 105°C for 72 hours, and the viscosity increase rate is a value obtained by dividing a difference between a viscosity of the silicone-based resin composition after being allowed to stand and an initial viscosity of the silicone-based resin composition by the initial viscosity of the silicone-based resin composition.

[0162] In the silicone-based resin composition according to an embodiment, the viscosity increase rate may be less than 0.07. In the silicone-based resin composition according to an embodiment, the viscosity increase rate may be less than 0.05. In the silicone-based resin composition according to an embodiment, the viscosity increase rate may be less than 0.03. In the silicone-based resin composition according to an embodiment, the viscosity increase rate may be less than 0.02. In the silicone-based resin composition according to an embodiment, the viscosity increase rate may be less than 0.01.

[0163] The method of preparing a silicone-based resin composition according to an embodiment includes a step of modifying an alkoxy group into a hydroxy group and a step of modifying a hydroxy group into a siloxane group. The method of preparing a silicone-based Wal2440S

[0164] resin composition according to an embodiment may prepare the first organic polysiloxane by reacting the first alkoxy silane with the second alkoxy silane, and may modify an alkoxy group included in the first organic polysiloxane into a siloxane group.

[0165] Accordingly, the silicone-based resin composition according to an embodiment may include an alkoxy group in a very low content or may exclude the same.

[0166] Accordingly, the silicone-based resin composition according to an embodiment may have consistent reactivity. That is, since the silicone-based resin composition according to an embodiment hardly contains an alkoxy group that may affect a reaction rate, a reaction rate variation may be reduced.

[0167] In addition, since that silicone-based resin composition according to an embodiment hardly contains an alkoxy group, constant properties may be maintained even if stored for a long time. In particular, since the silicone-based resin composition according to an embodiment has the aforementioned viscosity increase rate, storage stability may be improved.

[0168] Hereinafter, examples and a comparative example are described in more detail for the purpose of clarifying the effect of the present invention, but the present invention is not limited thereto.

[0169] Preparation Example

[0170] First alkoxy silane

[0171]

[0172] Wal2440S

[0173] hydrogenated siloxane

[0174]

[0175] Example 1

[0176] 1.4 parts by mole of the first alkoxy silane, 2.4 parts by mole of the second alkoxy silane, 1 part by mole of the hydrogenated siloxane and 58 parts by mole of water were uniformly mixed. 0.19 parts by weight of an aqueous hydrochloric acid solution (concentration: 20 wt%), based on 100 parts by weight of the mixture, was added to the mixture, the reaction proceeded at about 80 °C for 2 hours, and the temperature was reduced. Next, 0.18 parts by weight of an aqueous ammonia solution (concentration: 25 wt%) were added to the reactant at about 70 °C and reacted at about 80 °C for 3 hours. Next, the reactant was neutralized with an aqueous hydrochloric acid solution. Next, the reactant was washed with an aqueous sodium chloride solution (concentration: 20 wt%) and purified with toluene. As a result, a first polyorganosiloxane dissolved in toluene was obtained.

[0177] Next, 114 parts by weight of acetonitrile, 8 parts by weight of water and 0.08 parts by weight of an aqueous hydrochloric acid solution (concentration: 20 wt%) were mixed based on 100 parts by weight of the first polyorganosiloxane. Next, the reaction proceeded at about 80 °C for about 2 hours. Next, the reactant was washed with an aqueous sodium chloride solution (concentration: 20 wt%) and purified with toluene. Accordingly, a second polyorganosiloxane dissolved in toluene was obtained.

[0178] Next, about 20 parts by weight of hexamethyldisilazane were added to 100 parts by weight of the second polyorganosiloxane Next, the reaction proceeded at about 80 °C for about 3 hours. The reactant was washed with an aqueous sodium chloride solution (concentration: 20 wt%), subjected to a water removal process, and purified with toluene. As a result, a third polyorganosiloxane dissolved in toluene was obtained.

[0179] [Table 1 ]

[0180]

[0181] Wal2440S

[0182]

[0183] Comparative Example

[0184] The first polyorganosiloxane of Example 1 was used as a comparative example.

[0185] Evaluation Example

[0186] 1. 'H-NMR

[0187] To confirm the structure of the sample synthesized in each of the following Examples 1 to 4 and Comparative Example 1, nuclear magnetic resonance analysis was performed. In the nuclear magnetic resonance analysis, 'H-NMR spectrum was analyzed using a Varian 400MR (400 MHz), and measurement was performed in a state of being dissolved in CDCh. The internal standard was CHC12 (-7.24 ppm).

[0188] Phenyl group: Located between about 7 ppm to about 8 ppm

[0189] H-Si: Located between about 4.5 ppm to about 5 ppm

[0190] Methyl-Si: Located between about -0.5 ppm to about 0.5 ppm

[0191] Methoxy: Located between about 3.3 ppm to about 3.7 ppm

[0192] Ethoxy: Located between about 1 ppm to about 1.4 ppm and about 3.7 ppm to about 3.9 ppm

[0193] 2. Viscosity measurement

[0194] To compare the thermal stability of Examples 1 to 4 and Comparative Example 1, a viscosity was measured at 25°C using ANTON PAAR Rheometer MCR302. The viscosities before and after the synthesis of the first polyorganosiloxane and the viscosities before and after the synthesis of the third polyorganosiloxane were respectively measured. The first polyorganosiloxane and the third polyorganosiloxane of Examples were allowed to stand at about 105°C for about 72 hours, and the initial viscosity and after-standing viscosity thereof were respectively measured.

[0195] 3. Long-term storage stability Wal2440S

[0196] After preparing of the polyorganosiloxane composition of each of the examples and the comparative example, the polyorganosiloxane composition was stored at room temperature in a sealed state for 90 days, and then was subjected to long-term storage stability measurement. O: No increase in viscosity after storage for 90 days (less than 5%)

[0197] X: Viscosity increased after storage for 90 days (greater than 5%)

[0198] As shown in Table 2 below, each area was derived from 1H-NMR.

[0199] [Table 2]

[0200]

[0201] As shown in Table 3 below, a viscosity change rate and long-term storage stability were derived.

[0202] [Table 3]

[0203]

[0204] Wal2440S

[0205] As shown in Tables 2 and 3, the silicone-based resin composition according to an embodiment may have improved storage stability.

[0206] [Description of Symbols]

[0207] S10: condensation reaction

[0208] S20: first modification reaction

[0209] S30: second modification reaction

Claims

Wal2440S[CLAIMS]

1. A method of preparing a silicone-based resin composition, the method comprising: preparing a first polyorganosiloxane by reacting a first alkoxy silane with a second alkoxy silane;preparing a second polyorganosiloxane by modifying an alkoxy group comprised in the first polyorganosiloxane into a hydroxy group; andpreparing a third polyorganosiloxane by modifying the hydroxy group comprised in the second polyorganosiloxane into a siloxane group.

2. The method according to claim 1, wherein, in the preparing of the first polyorganosiloxane, the first alkoxy silane, the second alkoxy silane and a hydrogenated siloxane are reacted.

3. The method according to claim 1, wherein the first alkoxy silane is represented by Chemical Formula 1 below:[Chemical Formula 1]SiRJxR xwhere R1is at least one selected from the group consisting of hydrogen, a substituted or unsubstituted aryl group, and a substituted or unsubstituted alkyl group, R2is a substituted or unsubstituted alkoxy group, and x is an integer from 1 to 3.

4. The method according to claim 1, wherein the second alkoxy silane is represented by Chemical Formula 2 below:[Chemical Formula 2]SiR3yR44-ywhere R3is at least one selected from the group consisting of hydrogen, a substituted or unsubstituted aryl group, and a substituted or unsubstituted alkyl group, R4is a substitutedWal2440Sor unsubstituted alkoxy group, and y is an integer from 1 to 3.

5. The method according to claim 2, wherein the hydrogenated siloxane is represented by Chemical Formula 3 below:[Chemical Formula 3]SixR5yHzOwwhere R5is at least one selected from the group consisting of a substituted or unsubstituted aryl group and a substituted or unsubstituted alkyl group, x is an integer from 2 to 10, y is an integer from 2 to 20, z is an integer from 2 to 10, and w is an integer from 1 to 5.

6. The method according to claim 1, wherein the preparing of the second polyorganosiloxane comprises reacting by adding a strong acid to the first polyorganosiloxane.

7. The method according to claim 1, wherein the preparing of the third polyorganosiloxane comprises reacting by adding silazane to the second polyorganosiloxane.

8. The method according to claim 1, wherein an alkoxy group ratio in the third polyorganosiloxane is less than 0.005,wherein the alkoxy group ratio is a value obtained by dividing an area of a peak derived from an alkoxy group by an area of all peaks, in nuclear magnetic resonance of the third polyorganosiloxane.

9. A silicone-based resin composition, comprising a polyorganosiloxane represented by average Compositional Formula 5 below,wherein an alkoxy group ratio in the polyorganosiloxane is less than 0.005,Wal2440Swherein the alkoxy group ratio is a value obtained by dividing an area of a peak derived from an alkoxy group by an area of all peaks, in nuclear magnetic resonance of the polyorganosiloxane,[Compositional Formula 5]RJaSiO (4-a) / 2where R1denotes one or more groups selected from the group consisting of a hydrogen atom, a hydroxyl group, and a saturated or unsaturated monovalent hydrocarbon group having 1 to 18 carbon atoms, and a is 0 to 3.5.

10. A silicone-based resin composition, comprising a polyorganosiloxane represented by average Compositional Formula 5 below,wherein the silicone-based resin composition has a viscosity increase rate of less than 0.07 measured by Measurement method below,[Compositional Formula 5]R^SiO (4-a) / 2where R1denotes one or more groups selected from the group consisting of a hydrogen atom, a hydroxyl group, and a saturated or unsaturated monovalent hydrocarbon group having 1 to 18 carbon atoms, and a is 0 to 3.5,[Measurement method]the silicone-based resin composition is allowed to stand at 105°C for 72 hours, and the viscosity increase rate is a value obtained by dividing a difference between a viscosity of the silicone-based resin composition after being allowed to stand and an initial viscosity of the silicone-based resin composition by the initial viscosity of the silicone-based resin composition.

11. The silicone-based resin composition according to claim 10, wherein R1is at least one selected from the group consisting of a hydrogen atom, a hydroxy group, an alkyl group and an aryl group.

12. The silicone-based resin composition according to claim 10, wherein theWal2440Spolyorganosiloxane is represented by Chemical Formula 6 below:[Chemical Formula 6]where R6is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms, R7is a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, R8is a hydrogen atom or a substituted or unsubstituted alkyl group having 1 to 10 carbon atoms, m is 1 to 1500, n 1 to 2000, and k is 1 to 1000.

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