KR100683428B1 - Silicone resin compositions having good solution solubility and stability - Google Patents

Abstract

The present invention relates to a soluble silicone resin composition having excellent solution stability, a method for preparing the same, a nanoporous silicone resin and a film, and a method for producing the same. The silicone resin is composed of a mixture comprising 15 to 70 mol% of tetraalkoxysilane (A) of Formula 1, 12 to 60 mol% of hydrosilane (B) of Formula 2 and 15 to 70 mol% of organotrialkoxysilane (C) of Formula 3 Reaction product in the presence of water (D), a hydrolysis catalyst (E) and an organic solvent (F) for the reaction product.

Formula 1

Si (OR ¹ ) ₄

Formula 2

HSiX ₃

Formula 3

R ² Si (OR ³ ) ₃

In Chemical Formulas 1 to 3 above

Each R ¹ is independently selected from an alkyl group having 1 to 6 carbon atoms,

Each X is independently selected from hydrolyzable substituents,

R ² is a substituted hydrocarbon group comprising a hydrocarbon group of 8 to 24 carbon atoms or a hydrocarbon chain of 8 to 24 carbon atoms,

Each R ³ is independently selected from alkyl groups having 1 to 6 carbon atoms.

Nanoporous silicone resin, dielectric constant, solubility, siloxane resin, weight average molecular weight

Description

Silicone resin compositions having good solution solubility and stability

The present invention relates to a soluble silicone resin composition excellent in solution stability and a method for producing the same. The silicone resin of the present invention is useful for forming a microporous film having a low dielectric constant.

Semiconductor devices typically have one or more arrays of patterned interconnect levels that electrically couple each circuit device forming an integrated circuit (IC). These interconnect levels are typically separated by an insulating or dielectric film. Previously, silicon oxide films formed using chemical vapor deposition (CVD) or plasma enhanced technology (PECVD) have typically been used as such materials for dielectric films. However, as the size of the circuit elements and the spacing between these elements are reduced, the relatively high dielectric constant of such silicon oxide films is inadequate to provide adequate electrical insulation.

In order to provide a dielectric constant lower than that of silicon oxide, dielectric films formed from siloxane based resins are used. Examples of such films are those formed from poly (hydrozine) silsesquioxane resins as described in US Pat. Nos. 3,615,272 and 4,756,977. While such films provide lower dielectric constants than CVD or PECVD silicon oxide films and also provide other benefits such as improved gap filling and surface planarization, the dielectric constant of such films is typically limited to approximately three or more.

It is understood that the dielectric constant of the insulating films discussed above is an important factor when ICs with low power consumption, cross-talk and signal delay are required. As IC dimensions continue to shrink, the importance of the dielectric constant also increases. As a result, there is a need for a method for producing such a material that can provide a siloxane resin material and an electrically insulating film having a dielectric constant of 3 or less. There is also a need for a method of preparing such a resin that provides a siloxane-based resin and a low dielectric constant film with high resistance to cracking. In addition, in the case of the siloxane-based resin as described above, it is preferable to provide a film having a low dielectric constant by standard processing techniques.

It is known that the dielectric constant of a solid film decreases as the density of the film material decreases. Thus, considerable research has been conducted to develop microporous insulating films for use on semiconductor devices.

U. S. Patent No. 5,494, 859 describes an insulating layer having a low dielectric constant for an integrated circuit structure and a method of making such an insulating layer. The porous layer is formed by depositing on the structure a composite layer comprising an insulating matrix material and a material that can be converted to a gas during the conversion process. The gas release leaves a porous matrix of insulating material with a lower dielectric constant than the composite layer. The matrix forming material is typically silicon oxide and an example of a material that can be converted to a gas during the conversion process is carbon.

US Pat. No. 5,776,990 describes insulating foamed polymers prepared by heating the copolymer above the decomposition temperature of the thermally decomposable polymer from copolymers having a pore size of 100 nm or less and comprising matrix polymers and pyrolysable polymers. The copolymer described is an organic polymer that does not contain silicon atoms.

WO 98/49721 describes a process for forming a nanoporous dielectric coating on a substrate. The process comprises blending an alkoxysilane with a solvent composition and optional water; Depositing the mixture on a substrate while evaporating at least a portion of the solvent; Placing the substrate in a sealed chamber and evacuating the chamber to a pressure below atmospheric pressure; Exposing the substrate to water vapor at sub-atmospheric pressure and then exposing the substrate to substrate vapor.

Japanese Unexamined Patent Application Publication No. Hei 10-287746 teaches a method for producing a porous film from a siloxane resin having an organic substituent which is oxidized at a temperature of 250 ° C. or higher. Useful examples of organic substituents that can be oxidized at temperatures above 250 ° C. provided in this document are 3,3,3-trifluoropropyl, β-phenethyl groups, t-butyl groups, 2-cyanoethyl groups, benzyl groups And substituted or unsubstituted groups as exemplified by vinyl groups.

See Mikoshiba et al., J. Mat. Chem., 1999, 9, 591-598, report a method of forming void-sized pores in poly (methylsilsesquioxane) to reduce film density and dielectric constant. A copolymer comprising methyl (trisiloxysilyl) units and alkyl (trisiloxysilyl) units is spin-coated on a substrate and heated at 250 ° C. to provide a hard siloxane matrix. Thereafter, when the film is heated to 450 to 500 ° C. to remove the thermally unstable group, a hole corresponding to the size of the substituent remains. Trifluoropropyl, cyanoethyl, phenylethyl, and propyl groups were investigated with thermally labile substituents.

WO 98/47945 discloses a process for reacting trichlorosilane with organotrichlorosilane to form an organohydridosiloxane polymer having a cage conformation and having a carbon-containing substituent of approximately 0.1 to 40 mol%. This is taught. Resins formed from these polymers have been reported to have dielectric constants of less than three.

It is an object of the present invention to provide silicone resins that are soluble in organic solvents such as toluene, have a usable solution shelf-life, and are suitable for forming crack-free electrically insulating films on electrical devices. Another object is to provide a silicone resin composition which can be coated on a substrate and then heated to form a microporous film having a narrow pore size distribution and a low dielectric constant. The low dielectric constant film may be formed on an electrical component such as a semiconductor device by a conventional method to form a crack-free microporous film having a dielectric constant of 2 or less.

The present invention relates to a soluble silicone resin composition excellent in solution stability and a method for producing the same. The silicone resin is useful for the production of microporous films having a low dielectric constant.

One aspect of the invention is a nanoporous silicone resin that is soluble in standard solvents useful for applying a dielectric coating to electrical components. The silicone resin of the present invention is based on the total moles of component (A) + component (B) + component (C), 15 to 70 mol% of tetraalkoxysilane (A) of Formula 1, hydrosilane (B) of Formula 2 A mixture comprising 12 to 60 mol% and 15 to 70 mol% of organotrialkoxysilane (C) of formula 3 is reacted in the presence of water (D), a hydrolysis catalyst (E) and an organic solvent (F) for the reaction product. Reaction products.

Si (OR ¹ ) ₄

HSiX ₃

R ² Si (OR ³ ) ₃

In Chemical Formulas 1 to 3 above

Each R ¹ is independently selected from an alkyl group having 1 to 6 carbon atoms,

Each X is independently selected from hydrolyzable substituents,

R ² is a substituted hydrocarbon group comprising a hydrocarbon group of 8 to 24 carbon atoms or a hydrocarbon chain of 8 to 24 carbon atoms,

Each R ³ is independently selected from alkyl groups having 1 to 6 carbon atoms.

Component (A) is tetraalkoxysilane of the formula (1). The inventors surprisingly found that the presence of component (A) in the range of 15 to 70 mol%, based on the total moles of component (A) + component (B) + component (C), is dependent on the solubility and stability of the silicone resin in the organic solvent. I found it important. If the mol% of component (A) is out of this range, the silicone resin is at least partially insoluble in the typical organic solvent used to form a solution of such resin for application as a coating. It is preferred that the mol% range of component (A) is within 25 mol% to 50 mol%. In formula 1, each R ¹ is independently selected from alkyl groups having 1 to 6 carbon atoms. R ¹ is, for example, methyl, ethyl, butyl, tert-butyl and hexyl. It is preferable that component (A) is tetramethoxysilane or tetraethoxysilane for availability.

Component (B) is a hydrosilane of formula (2). Component (B) is added to the mixture in an amount of 12 to 60 mol%, based on the total moles of component (A) + component (B) + component (C). If component (B) is added in an amount outside the above range, the solubility of the resulting silicone resin in the organic solvent may be limited. Component (B) is preferably added to the mixture in an amount of 15 to 40 mol%. In formula (2), X is a hydrolyzable substituent. X is a substituent which can be hydrolyzed from silicon atoms in the presence of water under the conditions of the above-described process and is a group that does not adversely affect the solubility or use of the silicone resin during hydrolysis. Examples of hydrolyzable substituents include halogens, alkoxy groups and acyloxy groups. It is preferable when X is an alkoxy group having 1 to 6 carbon atoms. Component (B) is trichlorosilane, trimethoxysilane, or triethoxysilane, for example, and trimethoxysilane and triethoxysilane are preferable.

Component (C) is an organotrialkoxysilane of formula (3). Component (C) is added to the mixture in an amount of 15 to 70 mol%, based on the total moles of component (A) + component (B) + component (C). Component (C) is important in providing a mechanism for providing microporosity to a film formed from a silicone resin. Specifically, component (C) comprises an unsubstituted or substituted hydrocarbon group R ² , which can form voids in the resulting silicone resin coating which is removed from the silicon atoms by pyrolysis during the heating process. Thus, the amount of component (C) added to the mixture is used to adjust the porosity of the resulting silicone resin after thermal curing to remove the R ² substituents by pyrolysis. Generally, an amount of component (C) of 15 mol% or less results in a silicone resin coating having a low porosity and poor solvent solubility to give optimum dielectric properties to the material, while the amount of component (C) is 70 mol% Above, resins are produced in which solubility in organic solvents is limited and physical properties such as crack resistance, when used as a porous coating on a substrate, may be inadequate. Component (C) is preferably added to the mixture in the range of 15 to 40 mol%.

In formula (3), R ² is a substituted hydrocarbon group comprising a hydrocarbon group having 8 to 24 carbon atoms or a hydrocarbon chain having 8 to 24 carbon atoms. R ² may be a linear, branched or cyclic hydrocarbon group. Substituted hydrocarbon groups may be substituted with substituents such as halogen, poly (oxyalkylene) groups of formula 4, alkoxy, acyloxy, acyl, alkoxycarbonyl and trialkylsiloxy groups.

-(O- (CH ₂ ) _m ) _x -CH ₃

In Formula 4 above,
m and x are both positive integers, preferably 1 to 6 positive integers.

It is preferred when R ² is a straight chain alkyl group having 8 to 24 carbon atoms. More preferred is when R ² is a straight alkyl group of 16 to 20 carbon atoms. Examples of R ² are octyl, chlorooctyl, trimethylsiloxyoctyl, methoxyoctyl, ethoxyoctyl, nonyl, decyl, dodecyl, hexadecyl, trimethylsiloxyhexadecyl, octadecyl and docosyl.

In formula (3), R ³ is each independently selected from alkyl groups having 1 to 6 carbon atoms. Examples of R ³ are methyl, ethyl, propyl, isopropyl, butyl, heptyl and hexyl. Preference is given to when R ³ is methyl or ethyl.

Specific examples of the organotrialkoxysilane of the formula (3) include octyltriethoxysilane, octyltrimethoxysilane, octadecyltrimethoxysilane, hexadecyltrimethoxysilane and dodecyltriethoxysilane. It is preferred if the organotrialkoxysilane is selected from the group consisting of octyltriethoxysilane, octadecyltrimethoxysilane and hexadecyltrimethoxysilane. Further examples of organotrialkoxysilanes are those represented by the following formula: (CH ₃ (CH ₂ ) ₁₇ -O-CH ₂ CH ₂ ) Si (OMe) ₃ , (CH ₃ (CH ₂ ) ₆ C (= O)-(CH ₂ ) ₈ CH ₂ ) Si (OMe) ₃ , (CH ₃ (CH ₂ ) ₁₇ -OC (= O) -CH ₂ CH ₂ ) Si (OMe) ₃ and (CH ₃ (CH ₂ ) _16- C (═O) —O—CH ₂ CH ₂ ) Si (OMe) ₃ , where Me is methyl.

Component (D) is water. Component (D) essentially completes the hydrolyzable groups attached to the silicon atoms of components (A), (B) and (C) without excessively generating a two-phase mixture that can slow the reaction. It is preferred to add in an amount sufficient to hydrolyze. In general, it is preferred that the amount of water added is in the amount of 1.4 to 6 moles per mole of components (A), (B) and (C). It is even more preferred to add water in an amount of 2.5 to 4.5 moles on the same basis.

Component (E) is a hydrolysis catalyst and may be one of organic or inorganic acids and bases known in the art to catalyze the hydrolysis of substituents from silicon atoms in the presence of water. The hydrolysis catalyst may be an inorganic base such as potassium hydroxide or sodium hydroxide. The hydrolysis catalyst can be an inorganic acid such as hydrogen chloride, sulfuric acid and nitric acid. The hydrolysis catalyst can be added separately to the reaction mixture or, if component (B) is trihalosilane, at least in part can be generated in situ. Preferred hydrolysis catalysts are hydrogen chloride, which may occur at least in part when component (B) is trichlorosilane.

The amount (catalyst amount) of hydrolysis catalyst added to the reaction mixture is an amount that facilitates the hydrolysis of the silicon-bonded hydrolyzable groups of components (A), (B) and (C) and the optimum amount is not only the chemical composition of the catalyst It depends on the temperature at which the hydrolysis reaction occurs. In general, the amount of hydrolysis catalyst ranges from 0.02 to 0.5 moles per mole of components (A), (B) and (C). It is preferable that the amount of the hydrolysis catalyst is 0.1 to 0.3 moles on the same basis.

Component (F) is an organic solvent for the reaction product. Component (F) may be one or a mixture of organic solvents in which the reaction product forms a homogeneous solution. Examples of useful solvents include ketones (e.g. methyl isobutyl ketone) and aromatic hydrocarbon solvents (e.g. toluene, xylene, mesitylene, isobutyl isobutyrate, benzotrifluoride, propylbenzene, isobutyl propionate, propyl butyrate, Parachlorobenzotrifluoride and n-octane). The amount of organic solvent is an amount sufficient to form a homogeneous solution of the reaction product. In general, it is preferred that the organic solvent comprises 70 to 95% by weight, preferably 85 to 95% by weight of the total amount of components (A) to (F).

In a preferred process for producing a reaction product comprising a silicone resin, components (A), (B), (C) and (F) are combined to form a primary mixture. Thereafter, component (D) and component (E), separately or as a mixture, are added to the primary mixture and mixed to form a reaction product. The formation of the reaction product is carried out at any temperature in the range of 15 to 100 ° C., with room temperature being preferred. In a preferred process after the reaction has ended, the volatiles are removed from the reaction product under reduced pressure to isolate the resin solution. Such volatiles include alcohol by-products, excess water, catalysts and solvents. If desired, all solvents can be removed from the resin solution to form a solid resin. When all the solvent is removed to isolate the solid resin, the temperature of the resin solution should be maintained at 60 ° C or lower, preferably within the range of 30 to 50 ° C. Excessive heating can form insoluble resins. In some cases, the catalyst and the alcoholic by-product may be separated by washing one or more times with water together with the intermediate phase separation to recover the solution of the silicone resin in the solvent.

The silicone resin comprising the reaction product as described above may contain Si—OH functional groups and may contain Si—OR ³ functional groups, where R ³ is as described above. To a silicone resin comprising 10 to 30mol% and SiOH Si-OR ³ 0 to about 10mol% being preferred.

A further aspect of the present invention is a method of increasing the molecular weight and improving the storage stability of a reaction product comprising a silicone resin prepared as described above (hereinafter referred to as the "bodying method"). The main method comprises the steps of (i) forming a solution of the silicone resin in 10 to 60% by weight of an organic solvent in the presence of any condensation catalyst, sufficient to carry out the condensation of the silicone resin at a weight average molecular weight of 100,000 to 400,000. Heating the solution to temperature (ii) and neutralizing the solvent solution of the silicone resin (iii). In step (i) of the reaction, it is preferred that the silicone resin is present in an organic solvent at 20 to 30% by weight. The organic solvent may be one of the organic solvents described above. Any condensation catalyst added in step (i) is one of the acids and bases described above as a hydrolysis catalyst for forming the reaction product. Preferred condensation catalysts are hydrogen chloride at a concentration of 5 to 200 parts by weight of HCl per 1,000,000 parts of resin solids. More preferably, the condensation reaction catalyst is hydrogen chloride having a concentration of 10 to 50 parts by weight of HCl per 1,000,000 parts of resin solids.

The temperature at which the solution of the silicone resin is heated in step (ii) is from 50 ° C. up to the reflux temperature of the solution. In a preferred manner, the solution of the silicone resin is refluxed to increase the weight average molecular weight. In step (ii), it is preferable to heat the solution of the silicone resin so that the weight average molecular weight of the silicone resin after heating is 150,000 to 250,000. In step (iii) of the method, the solvent solution of the silicone resin is neutralized. Neutralization is carried out by washing the solution one or more times with water or by removing the solvent under reduced pressure and re-dissolving the silicone resin in the organic solvent one or more times. The organic solvent used for the neutralization step is one of the organic solvents described above.

Solution stability of the neutralized silicone resin is also improved by dissolving the silicone resin in an organic solvent or organic solvent mixture and adding 0.05 to 0.4 weight percent water, based on the total amount of silicone resin, solvent and water. It is preferable to add 0.1 to 0.25% by weight of water on the same basis. The organic solvent is one or a mixture of these organic solvents, and isobutyl isobutyrate is a preferred solvent.

The silicone resins of the present invention are particularly useful as films having a low dielectric constant on electrical devices such as integrated chips, but can also be used as fillers, for example in chromatography columns. The silicone resin is made porous by pyrolysis of carbon-carbon bonds by curing and heating. Thus, a further aspect of the present invention is a porous silicone resin and a porous silicone resin film and a method of making them.

Specifically, the present invention relates to a method of forming a nanoporous silicone resin. The term "nanoporous" means a silicone resin having a pore diameter of less than 20 nm. A preferred embodiment of the invention is an electrical substrate containing a nanoporous coating of silicone resin. In a preferred embodiment of the invention, the pore diameter of the nanoporous coating is between 0.3 and 2 nm. Reaction products comprising silicone resins, in the case of solids, are dissolved and diluted in an organic solvent as described above, isobutyl isobutyrate and mesitylene are preferred solvents for forming the coating solution. The concentration of the silicone resin in the organic solvent is not so important for the present invention and is the concentration at which the silicone resin is soluble and provides acceptable fluidity to the solution in the coating process. Generally, it is preferable that the concentration of the silicone resin in the organic solvent is 10 to 25% by weight. The silicone resin is coated onto the substrate by standard methods for forming coatings on electronic components, such as spin coating, flow coating, immersion coating and spray coating. The substrate with the silicone resin coating is then heated to a temperature sufficient to cure the silicone resin coating in an inert atmosphere and to thermally decompose the R ² groups from the silicon atoms. Heating can be carried out in a one step process or in a two step process. In the two-step process, the silicone resin is first heated to a temperature sufficient to cure the R ² groups from the silicon atoms without any reliably pyrolysis, preferably in an inert atmosphere. Generally, this temperature is between 20 and 350 ° C. The cured silicone resin is then further heated to temperatures above 350 ° C. up to a temperature below the decomposition temperature of the silicone resin polymer backbone or a temperature that causes undesirable effects on the substrate to pyrolyze the R ² groups from silicon atoms. In general, the pyrolysis step is preferably carried out at a temperature of 350 ° C. or higher and 600 ° C., most preferably 400 ° C. to 550 ° C. In the one-step process, the curing of the silicone resin and the thermal decomposition of the R ² group from the silicon atoms are carried out at a temperature of at least 350 ° C. above the decomposition temperature of the silicone polymer backbone or at a temperature below which undesirable effects are produced on the substrate. It is carried out simultaneously by heating. In general, the one-step heating method is preferably performed at a temperature of 350 ° C. to 600 ° C., most preferably 400 ° C. to 550 ° C.

The one or two stage heating process for forming the nanoporous coating on the substrate is preferably carried out in an inert atmosphere. Inert atmospheres are preferred because the presence of oxygen can increase the dielectric constant for the silicone resin by oxidizing the Si-H bonds to increase the residual silanol concentration in the film. However, in some cases, a small amount of oxidant such as oxygen may be present in the atmosphere to tailor the properties of the resulting nanoporous silicone resin. Inert atmospheres are one of those known in the art, for example argon, helium or nitrogen.

Nanoporous silicone resins formed by the methods described above are particularly useful as low dielectric constant films on electrical devices such as integrated chips. The dielectric constant of the nanoporous silicone resin coating prepared by the method of the present invention is less than two. Such nanoporous silicone resins can also be prepared in a specific form by standard methods such as spray drying and heating as described above to become nanoporous and used for other applications where fillers and porous materials in chromatography columns are used. have.

The following examples are provided to illustrate the present invention. In the examples, all parts are expressed in parts by weight and mol% are based on the total moles of component (A) + component (B) + component (C) as described below. Molecular weights are reported by weight average molecular weight (Mw) as measured by gel permeation chromatography (GPC) using toluene mobile phase and corrected for polystyrene standards.

Example 1-Samples 1-1 to 1-14

The components (A), (B), (C) and (F) as described below in the amounts described in Table 1 were combined in a glass container to prepare a silicone resin:

Tetraethoxysilane (A),

Triethoxysilane (B),

Octadecyltrimethoxysilane (C) and

A mixture of methyl isobutyl ketone (MIBK) and toluene (85:15 weight ratio) (F).

To the mixture was added a mixture of water (D) and hydrogen chloride (E) in the amounts shown in Table 1. In Samples 1-1 to 1-14, the weight part of component (C) is one. The resulting reaction product was stripped of volatiles at 60 ° C. under reduced pressure. The solubility of the resulting solid silicone resin was tested for toluene solubility by adding 8.3 g of toluene to 1.7 g of the solid silicone resin and stripping after 24 hours. Solids are considered to be soluble in toluene when a clear solution is formed and no particles or gels are visible. Toluene solubility is also reported in Table 1. The data presented in Table 1 demonstrate the importance of the mol% of components (A) and (B) in the solubility of the silicone resin.

Effect of mol% of components (A) and (B) on toluene solubility of silicone resin Sample number Parts by weight mol% Toluene Solubility (A) (B) (D) (E) (F) (A) (B) 1-1 0.56 1.32 0.84 0.078 12.0 20 60 O 1-2 0.70 1.21 0.86 0.079 12.1 25 55 O 1-3 0.84 1.10 0.87 0.080 12.2 30 50 O 1-4 0.97 0.98 0.88 0.081 12.2 35 45 O 1-5 1.11 0.88 0.90 0.082 12.3 40 40 O 1-6 1.25 0.77 0.91 0.084 12.4 45 35 O 1-7 1.39 0.66 0.92 0.085 12.5 50 30 O 1-8 1.67 0.44 0.95 0.087 12.6 60 20 O 1-9 1.81 0.33 0.96 0.088 12.7 65 15 O 1-10 * 0.00 1.75 0.79 0.073 11.7 0 80 × 1-11 * 0.28 1.53 0.82 0.075 11.9 10 70 × 1-12 * 0.42 1.42 0.83 0.076 12.0 15 65 × 1-13 * 1.95 0.22 0.98 0.090 12.8 70 10 × 1-14 * 2.22 0.00 1.00 0.092 12.9 80 0 × * Not an embodiment of the present invention.

Further analysis of the resin described in Samples 1-3 by Si ²⁹ and C ¹³ NMR showed 25 mol% SiOH and 5 mol% SiOR ³ , where R ³ is methyl or ethyl.

Example 2

Samples 2-1 to 2-6 were prepared in the same manner as the samples described in Example 1, with the following exceptions. The mol% of component (A) is kept constant at 30 mol% (1 part by weight). The amounts of each other component as described in Example 1 are shown in Table 2 along with the toluene solubility of the resulting silicone resin.

Effect of mol% of Component (C) on Toluene Solubility of Silicone Resin Sample number Parts by weight mol% Toluene Solubility (B) (C) (D) (E) (F) (B) (C) 2-1 1.05 1.80 1.047 0.0960 18.8 40 30 O 2-2 1.16 1.56 1.045 0.0959 17.1 44 26 O 2-3 1.29 1.26 1.046 0.0959 15.0 49 21 O 2-4 1.42 0.96 1.046 0.0959 13.0 54 16 O 2-5 * 1.50 0.78 1.045 0.0958 11.7 57 13 × 2-6 * 1.58 0.60 1.046 0.0959 10.5 60 10 × * Not an embodiment of the present invention.

Example 3

Samples 3-1 to 3-3 are prepared according to the method described in Example 1, wherein component (C) is (C-1) hexadecyltrimethoxysilane or (C-2) as shown in Table 3 Octyltriethoxysilane. The amount of each component [weight parts by weight of (A)] is shown in Table 3 together with the toluene solubility of the resulting resin.

Sample number Parts by weight mol% Toluene Solubility (C) form (B) (C) (D) (E) (F) (A) (B) (C) 3-1 C-1 0.99 1.80 1.05 0.096 20.13 30 37.5 32.5 O 3-2 C-2 0.92 1.55 1.05 0.10 13.73 30 35 35 O 3-3 C-2 0.63 2.92 1.24 0.11 21.88 25 20 55 O

Example 4

Preparation of silicone resin using hydrogen chloride formed in situ as hydrolysis catalyst

The silicone resin was subjected to a process similar to that described in Example 1, 1 part of tetraethoxysilane (A), 1.08 parts of trichlorosilane (B), 1.19 parts of octadecyltrimethoxysilane (C), 1.03 parts of water (D), And 14.87 parts of a mixture (85:15 weight ratio) (F) of MIBK and toluene were prepared. The mixture is refluxed for 5 minutes and the volatiles are removed at 40 ° C. under vacuum. The resulting silicone resin was soluble in toluene as tested by the method described in Example 1.

Example 5

Effect of Heating and Hydrocarbon Substitution on Weight Average Molecular Weight of Silicone Resin

Samples 5-1 to 5-6 are prepared by a method similar to the method described in Example 1. Component (C) is octadecyltrimethoxysilane (C-1) or octyltriethoxysilane (C-2) as shown in Table 4. As described in Example 1, the mol% of component (C) and component (A) and component (B) are shown in Table 4. The amounts of component (D) and component (E) are the same as in Example 1. The silicone resin is recovered as a solid by removing the volatiles at 30 ° C. under vacuum. The solid silicone resin is dissolved at 30% by weight in toluene and heated under reflux while continuing to remove the elution water for the time shown in Table 4. The weight average molecular weight of the silicone resin was measured by GPC before and after heating and the results are shown in Table 4. Toluene solubility of the silicone resin was measured as described in Example 1, and all resins were toluene soluble before and after the heat treatment.

Mw silicone resin before and after heat treatment Sample number (C) form mol% Time (h) Mw (A) (B) (C) Before heating After heating 5-1 C-1 30 47 23 One 12,700 55,000 5-2 C-1 30 47 23 2 12,700 91,500 5-3 C-1 30 47 23 3 12,700 139,400 5-4 C-1 30 49 21 One 11,600 81,500 5-5 C-2 30 30 40 One 5,240 23,800 5-6 C-2 30 25 45 One 7,540 16,300

Example 6

A soluble silicone resin was formed by the method of Example 1, the sample was heated to be porous to measure porosity, and the physical properties of the sample coated on the substrate and the substrate-like coating were measured. The ingredients were added in the amounts shown in Table 5 to form soluble silicone resins.

ingredient Explanation Parts by weight mol% (A) Tetraethoxysilane One 30 (B) Triethoxysilane 1.31 50 (C) Octadecyltrimethoxysilane 1.20 20 (D) water 0.57 - (E) Hydrogen chloride 0.096 - (F) Mixture of MIBK and Toluene (85:15 weight ratio) 15.8 -

A sample of the solid resin was placed in a crucible and heated at 500 ° C. for 0.5 hour in nitrogen. The resulting solids are tested for nitrogen adsorption at 77 ° K using a Micrometrics Accelerated Surface Area and Porosimetry 2000 System (Micrometrics Instrument Corporation, Norcross, GA). It was 913 m <2> / g when the BET surface area was measured. HK analysis of the adsorption data (Horvath, J. Chem. Eng. Jpn., 1983, Vol. 16, p. 476) shows that the micropore volume of the solid is 0.41 cc / g, the pore size distribution is narrow, and the medium pore size Was found to be 0.83 nm.

A sample of a solid silicone resin is also dissolved at 17% by weight in toluene and used to spin coat the silicon wafer. The coated silicon wafer was heated at 450 ° C. for 1 hour under a nitrogen atmosphere. The resulting film had a thickness of 1.2 μm, a thickness variation of 0.9% and a dielectric constant of 1.8.

Example 7

Samples 1-1 to 1-4 are prepared by mixing components (A), (B), (C) and (F) as described below in the amounts shown in Table 6 in a glass container:

Tetraethoxysilane (A), (B) as described in Table 6, octadecyltrimethoxysilane (C) and a mixture of methyl isobutyl ketone (MIBK) and toluene (85:15 weight ratio) (F).

To the mixture is added a mixture of water (D) and hydrogen chloride (E) in the amounts shown in Table 6. The weight part of component (C) is 1. The mol% of components (A), (B) and (C) in each sample are 30%, 50% and 20%, respectively. Volatiles were stripped at 60 ° C. under reduced pressure from the resulting reaction product. The solubility of the resulting solid silicone resin was tested for MIBK solubility by adding 8.3 g of MIBK to 1.7 g of the solid silicone resin 24 hours after stripping was completed. If a clear solution formed and no particles or gels were visually observed, the solid was considered to be soluble in the solvent. MIBK solubility is shown in Table 6.

Characterization of Silicone Resin Compositions Sample number (B) form Parts by weight MIBK Availability (A) (B) (D) (E) (F) 1-1 MeSi (OMe) ₃ 0.83 0.91 0.87 0.081 14.4 O 1-2 MeSiCl ₃ 0.83 1.00 0.87 0 13.5 O 1-3 PrSiCl ₃ 0.83 1.18 0.87 0 15.3 O 1-4 PhSiCl ₃ 0.83 1.41 0.87 0 17.6 O

Samples 1-1, 1-3, and 1-4 are heated to make porous and the porosity is measured. A sample of solid resin was placed in the crucible and heated in nitrogen at 500 ° C. for 0.5 h. The resulting solids were tested for nitrogen adsorption at 77 ° C. using a Micrometrics ASAP 2000 system (Micrometrics Instrument Corporation, Norcross, GA). H-K analysis of adsorption data [Horvath, J. Chem. Eng. Jpn., 1983, Vol. 16, p. 476] was used to determine the median pore size and micropore volume. The results are shown in Table 7.

Nitrogen Adsorption Data of Nanoporous Resin Composition Soluble Resin Sample Number BET surface area (m ² / g) Micro-pore volume (cc / g) Middle pore diameter (nm) 1-1 386 0.180 0.62 1-3 437 0.203 0.60 1-4 564 0.263 0.57

Samples 1-1, 1-2 and 1-4 were coated onto the substrate and the physical properties of the coating on the substrate were measured. A sample of solid silicone resin was dissolved in MIBK at 17% by weight and used to spray coat the silicon wafer. The coated silicon wafer was heated at 450 ° C. for 1 hour under a nitrogen atmosphere. The data of the thin film is presented in Table 8.

Data about thin film Soluble Resin Sample Number Film thickness (nm) Dielectric constant 1-1 887 1.87 1-2 698 1.97 1-4 693 2.60

According to the present invention, it is possible to obtain a silicone resin composition having excellent solution solubility and having a dielectric constant of less than 2 of the coating obtained.

Claims (20)

delete delete A mixture comprising 15 to 70 mol% of tetraalkoxysilane (A) of Formula 1, 12 to 60 mol% of hydrosilane (B) of Formula 2 and 15 to 70 mol% of organotrialkoxysilane (C) of Formula 3 is prepared using water ( D), forming and reacting in the presence of a hydrolysis catalyst (E) and an organic solvent (F) for the reaction product. Formula 1 Si (OR ¹ ) ₄ Formula 2 HSiX ₃ Formula 3 R ² Si (OR ³ ) ₃ In Chemical Formulas 1 to 3 above Each R ¹ is independently selected from an alkyl group having 1 to 6 carbon atoms, Each X is independently selected from hydrolyzable substituents, R ² is a substituted hydrocarbon group comprising a hydrocarbon group of 8 to 24 carbon atoms or a hydrocarbon chain of 8 to 24 carbon atoms, Each R ³ is independently selected from alkyl groups having 1 to 6 carbon atoms. The method of claim 3, wherein water (D) is used in an amount of 1.4 to 6 mol per mol of component (A) + component (B) + component (C). 4. A process for producing a silicone resin according to claim 3, wherein the hydrolysis catalyst (E) is used in an amount of 0.02 to 0.5 mol per mol of component (A) + component (B) + component (C). The method for producing a silicone resin according to claim 3, wherein the hydrolysis catalyst is hydrogen chloride. The organic solvent (F) for the reaction product according to claim 3, wherein the organic solvent (F) for the reaction product is based on the total weight of component (A) + component (B) + component (C) + component (D) + component (E) + component (F). As a result, characterized in that used in an amount of 70 to 95% by weight, a method for producing a silicone resin. The process for producing a silicone resin according to claim 3, wherein the reaction product comprising the silicone resin is neutralized, the silicone resin is dissolved in an organic solvent, and then 0.05 to 0.4 wt% of water is added. 4. The reaction product of claim 3, wherein the reaction product comprising the silicone resin in the organic solvent is heated at a temperature sufficient to condense the silicone resin in the presence of any condensation catalyst such that the weight average molecular weight is from 100,000 to 400,000. , Method for producing silicone resin. A silicone resin obtainable by the method according to any one of claims 3 to 9. (A) coating a silicone resin composition comprising a silicone resin according to claim 10 on a substrate; and The coated substrate is heated to a temperature sufficient to cure the silicone resin and to thermally decompose the R ² groups from the silicon atoms, thereby forming a nanoporous silicone resin coating on the substrate, thereby forming the nanoporous silicone resin coating on the substrate. How to prepare on. The process of claim 11, wherein the heating of step (b) is carried out in a two-step process of a first step of heating the coated substrate at a temperature of 20 to 350 ° C and a second step of heating at a temperature of 350 ° C to 600 ° C. A process for producing a nanoporous silicone resin coating on a substrate, the method comprising: 12. The method of claim 11, wherein the coated substrate is heated in an inert atmosphere. 13. The method of claim 12, wherein the heating in the first step and the heating in the second step are performed in an inert atmosphere. A method of forming a nanoporous silicone resin comprising heating a silicone resin composition comprising the silicone resin according to claim 10 at a temperature sufficient to effect curing of the silicone resin and pyrolysis of the R ² group. Manufacturing method. Nanoporous silicone resin coating obtainable by the method according to claim 11. The nanoporous silicone resin coating of claim 16, wherein the pore diameter is less than 20 nm. The nanoporous silicone resin coating of claim 16, wherein the dielectric constant is less than two. Nanoporous silicone resin obtainable by the process according to claim 15. The nanoporous silicone resin of claim 19 wherein the pore diameter is less than 20 nm.