KR101472188B1 - Silicon composition - Google Patents

Abstract

The present application relates to silicone compositions and uses thereof.

Description

Silicon composition {Silicon composition}

The present application relates to silicone compositions and uses thereof.

The present application relates to the development of a composition for obtaining a thin film-like cured product having excellent adhesive strength and a curable composition in the form of a transparent elastomer film. The composition may include, for example, a liquid silicone resin (LSR: Liguid Silicon Rubber), and may also contain additives such as a crosslinking agent (curing agent) and a specific additive such as a catalyst for providing a three- Lt; / RTI > Mixed materials based on liquid silicone resins are designed to retain their liquid form for nearly infinite times at room temperature and to cure into the structure of the vulcanizates as the temperature increases. In the case of a device, the solution is spread over the surface. An elastic film having excellent adhesion with the inorganic surface is formed on the surface of the apparatus during the solvent removal step and the curing of the mixed material.

As exemplified in Non-Patent Documents 1 to 3, low molecular weight silicone resins generally having different compositions are used in the production of liquid silicone resin. These resins contain at least three vinyl residues linked to the end or middle of the silicon atom per polymer.

Vinyl group-containing liquid silicone resins can be prepared by reacting a polyfunctional organosilicon compound, such as oligohydridesiloxanes (OHS) or oligohydridesilanes, with at least two silicon-bonded hydrogen atoms per molecule, It hardens through hydrosilation. Multifunctional oligomethyl hydride siloxane (OMHS) is typically used. As disclosed in Patent Documents 1 and 2, curing occurs with participation of a catalyst such as, for example, a platinum group metal complex compound.

The refractive index of the formed transparent coating is mainly determined by the refractive index of the liquid silicone resin made of the bulk coating material. The refractive index value (refractive index: 1.39 to 1.40) of the oligomethylhydride siloxane crosslinking agent used for liquid silicone resin curing differs greatly from the refractive index value (R = 1,40 to 1,44) of a commercially available silicone resin It is worth noting [see non-patent documents 4 and 5].

In addition, the use of oligomethylhydride siloxane as the polyfunctional curing agent has little effect on the refractive index of the resultant material. There are many examples of compositions for obtaining liquid silicone resin compositions. These examples include the following.

For applications such as, for example, LED products for optical sensors and protective coatings, transparent materials with higher refractive index values are required. European Patent 20020075566 discloses polysiloxane synthesis and methods of making polymers and materials, and European Patent 0204171 describes a flexible silicon production process with high refractive index. High refractive index may be required in these applications.

This patent document describes a multi-step synthesis in which a siloxane homopolymer having a high refractive index is obtained by adding a cluster group modified through a 2-equivalent carbon bridge to the siloxane main chain. Usually, the cluster group is used to increase the refractive index of the material and is selected from aromatic, phenyl-, aryl-, arylalkyl-, cycloalkyl- and alkyl- groups present in linear, cyclic or branched form. The copolymer obtained in the next step may be selected from the group consisting of tetravinyl-tetramethyl-cyclotetrasiloxane, octamethyl-cyclotetra-siloxane, trimethyl-triphenyl-cyclo-trisiloxane but are not limited to, trymethyl-triphenyl-cyclo-trisiloxane, tetramethyl-tetraphenylcyclotetrasiloxane, trifluoropropyl-methyl-cyclo-trisiloxane, Hexaphenyl-cyclo-trisiloxane and octaphenylcyclotetrasiloxane are copolymerized from cyclic monomers in the preparation of copolymers.

The best known approach to developing refractive index materials is to use a silicone resin containing a vinyl group modified with a siloxane moiety containing an organic moiety in the silicon atom as the base of the polymer coating composition for improving the refractive index .

This approach is described, for example, in European Patent No. 86106247.9 as an illustration of how to obtain silicon with a high index of refraction.

In order to increase the refractive index value of the cross-linked polysiloxane, modified group produces a hydro-silane (HSi-O) or a vinyl siloxane maternal Society (CH ₂ = CH-SiO) hydrosilation addition reaction (hydrosilylation) a polymer comprising a.

As the organohydrosilane in general, materials of the following formula (I), (II) or (III) may be used.

R ¹ , R ² and R ³ are hydrocarbon substituents containing different or identical aromatic groups (phenyl-, naphtyl-, antranyl-, biphenyl-, etc.), which improve the refractive index of the polymer. For example, European Patent Publication No. 0204171 discloses a polymeric material such as phenyldimethylsilane, diphenylmethylsilane, phenylsilane, diphenylsilane, nethyphenylsilane, parabis-L (Dimethylsilyl) benzene, triphenylsilane, bis [p-dimethylsilyl] phenyl] ether, cyclohexyldimethylsilane, , 1,3-diphenyl-1,3-dimethyldisiloxane, and the like have been proposed.

Curing of the polymeric material The next step is carried out by hydrosilylation of the vinyl group with a silicone compound having at least two silicon hydrate groups (Si-H). The refractive index of the crosslinked polymer can be changed in the case of using the above-mentioned range of materials.

Of a copolymer comprising three different polymerized units comprising dimethylsiloxane ((CH ₃ ) ₂ SiO-), vinyldimethylsiloxane (CH ₂ = CHSiCH ₃ O-) and diorganosiloxane (R ₂ SiO-) Synthesis is a complex task.

Thus, it is very difficult to make general techniques for compositions based on silicone resins containing modified vinyl groups suitable for the manufacture of transparent coatings for various applications.

Conventional methods of curing modified liquid silicone resins using oligomethylhydride siloxanes having low refractive index values can reduce the effect of a modifying agent on the liquid silicone resin molecules to obtain a better effect. In particular, when all the other conditions are the same, there is a negative effect due to the conventional oligomethyl hydride siloxane having the refractive index value of the cured material when the difference in the degree of increase in refraction between the modified liquid silicone resin and the oligomethyl hydride siloxane becomes large. Can be deepened.

In such cases, the liquid silicone resin may be a commercially available linear silicone resin containing vinyl methyl-siloxane in its main chain. In addition, such a composition may include not only liquid silicone resins containing vinyl groups, but also organic solvents and platinum catalysts, as well as curing agents, with a high refractive index. Such a composition may be applied by a suitable technique, for example, a method of applying on a surface of a corresponding device in advance using a liquid material, a method of drying (removal of an organic solvent), a method of curing a film having a viscosity at a high temperature It may be that you need a method. With this method, a three-dimensional polymer network may be formed, resulting in complete removal of the volatile mixture and residual solvent. It is known that the optical properties of cured materials are affected by curing conditions such as polymerization time and solvent evaporation rate. In addition, most of the transparent silicone coatings are prepared by a liquid polymer composition that has been treated according to the process described above.

In addition, the use of additional elements in the mixture is not preferred because it can change the curing conditions and complicate the coating process.

In addition, the development of a polymeric silicone coating suitable for practical and versatile optical properties (refractive index, transmittance, discoloration prevention) improves existing technology and solves many problems. Development of a composition having a high refractive index value using a liquid silicone resin and a curing agent based on a multifunctional silicone hydrate is required.

Patent Document 1: UK Patent No. 1272705 (1972) Patent Document 2: UK Patent No. 1279045 (1972)

Non-Patent Document 1: Noll, W. Chemistry and Technology of Silicones. New York: Academic Press, 1968, 703 p. Non-Patent Document 2: M. Shatz Silikonovy kaucuk, Praha, S. Naklad.Tech.Liter., 1973 Non-Patent Document 3: Clarson, S. J. & Semlyen, J. A. (eds) 1993, Siloxane Polymers, Prentice Hall, New Jersey. Non-Patent Document 4: M.V. Sobolevskiy, O.A. Muzovskaya, G.S. Popeleva «Properties and applications of silicone organic materials», Moscow, Khimiya, 296p Non-Patent Document 5: L.M. Khananashvili «Chemistry and technology of elemental organic monomers and polymers», Moscow, Khimiya, 1998, p.528

The present application provides silicone compositions and uses thereof.

The main object of the present application is to develop a transparent silicon coating method which is cured by a hydrogen silylation reaction using oligohydride siloxane and has a higher refractive index than an equivalent coating obtained through a liquid phase diorganosilicon resin of similar composition.

Another goal is to simplify the process, thereby reducing the use of materials and improving the physical-mechanical properties of the silicone coating.

The multifunctional curing agent (crosslinking agent) presented in the present application is a low molecular weight organosilicon compound, that is, an oligophenylhydroxysilane (OPHS) having the following formula.

These compounds are commercially available and can be synthesized from phenyltrichlorosilane, which is easy to obtain, as a raw material, and are characterized by having a high refractive index (a refractive index is 1 or more).

The object is achieved by a process wherein the transparent silicone coating composition comprises a liquid diorganosiloxane rubber, a curing agent, a curing catalyst and an organic solvent, and is selected from the group consisting of oligophenylhydroxysilane having at least two hydrosilyl groups (Si-H) For example, by using a compound represented by the following formula (A).

(A)

Wherein n is 1 to 2, and R is a hydrogen atom or a phenyl group.

For example, the composition may comprise a liquid diorganosiloxane resin, an oligophenylene hydride silane, and a catalyst (ex. [H ₂ PtC ₆ .H ₂ O]) and also includes an organic solvent dissolved in isopropanol or the like .

The liquid silicone resin used is generally a linear polydiorganosiloxane containing an unsaturated vinyl moiety bonded to a silicon atom having a weight average molecular weight of 15000 to 10000. Generally, the content of the vinylorganosiloxane units in the chain is from 2 to 50 mol%. For example, isopropyl alcohol having about 0.1 molar concentration of [H ₂ PtC ₆ .6H ₂ O] can be used as a catalyst.

The organic solvent includes aromatic or alicyclic hydrocarbons such as benzene, ethylbenzene, toluene, xylene, cyclohexane, or mixtures thereof.

The present application uses oligophenylhydroxysilane (Formula A) as a crosslinking agent.

Due to the content of high aromatic residues, the silane has a high refractive index (1.60 or more).

The refractive index according to oligophenylhydroxysilane (OPHS) compound H _Ph : H _Si n _D ²⁵ HH
( 1 ) Ph-SiC ₆ H ₄ Si-Ph
HH 3.5: 1 1.6047 Ph Ph
( 2 ) m-H-SiC ₆ H ₄ Si-H
Ph Ph 12: 1 1.6327 OPHS B-1-9
(Isomer mixture) 3.9: 1 1.6173 OPHS B -10-32
(Isomer mixture) 9.5: 1 1.6328

The amount of Ph: H used in Examples B-1-9 is the same as that of Compound (1), and the amount of Ph: H used in B-10-32 corresponds to the compound (2).

The high functionality of the oligophenylhydroxysilane is due to its structure, i.e. the bonding structure between the polyvinylsiloxane polymers containing the functional group Si-H of 2 to 6 per molecule and the liquid phase through the hydrogen silylation reaction caused by the silane It is related to the integrated network in the curing process of silicone resin.

To synthesize the oligophenylhydroxysilane, commercially available phenylchlorosilane And an oligophenylene of the following formula (B) having a chlorosilyl substituent.

[Chemical Formula B]

(R = -Cl or Ph; n = 1, 2).

In the case where the oligophenylhydroxysilane is used as a crosslinking agent for curing the liquid silicone resin, the best molecular ratio (Si-H: SiCH = CH ₂ ) is 1.10: 1 to 1.20: 1. Considering this ratio range and the high molecular weight of the oligophenylhydroxysilane can be compared with conventional cross-linking agents, requiring a larger amount of cross-linking agent.

This advantage can increase the total refractive index value of the composition and provide a material having an improved refractive index value even after curing.

The present application provides silicone compositions and uses thereof.

Example  One.

A. Initial (s) corresponding to the structure of formula (A) Oligophenylhydroxy Silane  synthesis

(A) (n = 1, R = H)

Reaction scheme:

A four-necked flask is equipped with a thermometer, a reflux condenser, a dropping funnel and a magnetic stirrer. 30.4 g (over 2 times) of LiAlH ₄ (0.8 M) and 250 ml of diethyl ether are added. 42.8 g (0.1 M) of 1,4-bis- (phenyldichlorosilyl) -benzene [(C ₆ H ₅ SiCl ₂ ) ₂ ] C ₆ H ₄ are added using a 20% ether dropping funnel. The ratio of the added chlorosilane is controlled such that the temperature of the reaction mixture does not exceed 30 ° C. After all of the chlorosilane solution has been added, the reaction solution is heated for 3 hours and cooled at +5 占 폚. The cold water containing HCl is then added dropwise through the funnel. So that unreacted LiAlH ₄ is decomposed. The oligophenylhydroxysilane obtained in the ether solution is washed with distilled water until a natural reaction occurs. After this, the organic layer and CaCl ₂ are removed. The ether is evaporated under atm pressure and the residue is distilled under 1 mm Hg vacuum conditions. The fractions are separated at a boiling point of 177-178 DEG / 1 mm Hg. The yield of [(C ₆ H ₅ SiH ₂ ) ₂ ] C ₆ H ₄ is 83% in the initial chlorinated silane. The resulting product, 1,4-bis (C ₆ H ₅ SiCl ₂ ) ₂ C ₆ H ₄ , has a crystalline form at melting point 51-52 ° C.

Chloro silyl-phenylene _{Cl [(C 6 H 5 SiCl} ) C 6 H 4] in the same manner ₂ C ₆ H ₅ SiCl up from the _second and LiAlH ₄ (hydrosilylation) phenylene _{Hl [(C 6 H 5 SiH} ) C 6 H ₄ ] ₂ C ₆ H ₅ SiH ₂ (T _melt = 83-84 ° C) can be obtained. The yield was approximately 30%.

B. Curing of liquid silicone resin

11.2 g of polymethylvinylsiloxane rubber (Mw = 65000, m = 24.1 mol%, n D 20 = 1.41),

12.5 g of oligophenylhydroxysilane (M = 290, ratio Si-H / Si- = 1.2) having the structure:

And 3.8 × 10 ^-3 M of the H ₂ [PtCl ₆ ] (0.1 ml) dissolved in isopropanol were mixed with 76.3 g of toluene, and maintained at 30 ° C. for 30 minutes. The reaction mixture is then poured into pyridine and dried in air until the solvent is removed. The obtained film is further maintained at 120 DEG C for 1 hour. n _D ²⁰ = 1.54.

Example  2.

7.4 g of polymethylvinylsiloxane resin having the following structure

(M w = 33000, m = 34.2 mol.%, N _D ²⁰ = 1.44),

27.4 g (n = 1, R = Ph, M = 442, ratio Si-H / Si- = 1.3) of OPHS-

And 3.8 × 10 ^-3 M of the H ₂ [PtCl ₆ ] (0.1 ml) dissolved in isopropanol were mixed with 83.6 g of toluene, and the reaction solution was poured into a floridish for 30 minutes at 30 ^° C., Dry in air until removed. The obtained film is further maintained at 120 DEG C for 1 hour. n _D ²⁰ = 1.58.

Example  3.

12.5 g of polymethylsiloxane (M = 5000, n _D ²⁵ = 1.5525) having the structure shown below was used in the same manner.

35.0 g of OPHS-3 (refractive index of the entire mixture: n _D ²⁵ = 1.6112) was dissolved in 52.5 g of xylene and 0.15 g of catalyst H ₂ [PtCl ₆ ] (3.8 × 10 ^-3 M in isopropyl alcohol ). The solvent was evaporated in air and the residue was held at 60 캜 for 2 minutes and then left at 120 캜 for 1 hour. The crosslinked material obtained was n _D ²⁵ = 1.57 clear rigid film.

Example  4.

In the same manner, 22.5 g of methylvinylsiloxane of the same composition as in Example 3 was obtained from a mixture containing 11.25 g of OPHS (total refractive index n _D ²⁵ = 1.6277 of the mixture). Triphenyltrisilyl-phenylene of the formula:

A crosslinked material was obtained from a mixture containing 66.25 g of toluene and the catalyst H ₂ [PtCl ₆ ] .6H ₂ O.

The solvent was evaporated and the film was further held at 80 ° C for 2 hours and then held at 120 ° C for 1 hour. The obtained transparent rigid film had n _D ²⁵ = n _D ²⁵ = 1.59.

Example  5.

Example 3 and methyl vinyl siloxane, 7.0 g of OPHS (corresponding to the isomeric mixture having a ^{_{n D 25 = 1.6277, tryphenyltrihydrosilyl-}} phenylene) 28.0g of the same composition, 3.92 g of 1,4- bis (silyl-phenyl) -phenyl (OPHS-3 n _D ²⁵ = 1,612, according to the table), 61.08 g of xylene and a catalyst. After evaporating the solvent, a transparent and flexible film (n _D ²⁵ = 1.59) was obtained by curing (the same temperature condition as in Example 3).

Claims (6)

A composition for the production of a silicone cured body based on a liquid vinyl siloxane resin which is cured by hydrogen silylation and comprising a polyfunctional curing agent having at least two reactive silicone hydrate groups, A composition comprising an oligohydride phenylsilane:
(A)

In the formula (A), n is a number of 1 to 2, and R is hydrogen or a phenyl group. The composition of claim 1, further comprising a platinum hydrogen siloxane catalyst. The composition of claim 1, further comprising an organic solvent. A transparent silicone polymer cured product formed from the composition of claim 1. An electronic device comprising an electronic device coated with a cured product of the composition of claim 1. A light emitting diode comprising a light emitting element coated with a cured product of the composition of claim 1.