[go: up one dir, main page]

WO2005035630A1 - Hyperbranched polysiloxanes - Google Patents

Hyperbranched polysiloxanes Download PDF

Info

Publication number
WO2005035630A1
WO2005035630A1 PCT/US2004/020943 US2004020943W WO2005035630A1 WO 2005035630 A1 WO2005035630 A1 WO 2005035630A1 US 2004020943 W US2004020943 W US 2004020943W WO 2005035630 A1 WO2005035630 A1 WO 2005035630A1
Authority
WO
WIPO (PCT)
Prior art keywords
mol
hydrocarbyl
formula
hyperbranched polysiloxane
hyperbranched
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/US2004/020943
Other languages
French (fr)
Inventor
Shihe Xu
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dow Silicones Corp
Original Assignee
Dow Corning Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Dow Corning Corp filed Critical Dow Corning Corp
Publication of WO2005035630A1 publication Critical patent/WO2005035630A1/en
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
    • C08L83/04—Polysiloxanes
    • C08L83/08—Polysiloxanes containing silicon bound to organic groups containing atoms other than carbon, hydrogen and oxygen
    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07F—ACYCLIC, CARBOCYCLIC OR HETEROCYCLIC COMPOUNDS CONTAINING ELEMENTS OTHER THAN CARBON, HYDROGEN, HALOGEN, OXYGEN, NITROGEN, SULFUR, SELENIUM OR TELLURIUM
    • C07F7/00—Compounds containing elements of Groups 4 or 14 of the Periodic Table
    • C07F7/02—Silicon compounds
    • C07F7/08—Compounds having one or more C—Si linkages
    • C07F7/0834—Compounds having one or more O-Si linkage
    • C07F7/0838—Compounds with one or more Si-O-Si sequences
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
    • C08G77/04—Polysiloxanes
    • C08G77/06—Preparatory processes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
    • C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
    • C08L83/04—Polysiloxanes
    • C08L83/06—Polysiloxanes containing silicon bound to oxygen-containing groups

Definitions

  • the present invention relates to hyperbranched polysiloxanes and more particularly to hyperbranched polysiloxanes containing pendant silicon-bonded hydrogen atoms.
  • U.S. Patent No. 6,284,906 B 1 to Paulasaari et al. discloses methods for the preparation of hyperbranched siloxane polymers by anionic polymerization of a cyclotrisiloxane having the functional group Si-OH.
  • Morikawa et al. (Macromolecules, 1991, 24(12), 3469-3474) describe the synthesis of highly branched polysiloxane starburst polymers starting from tris[(phenyldimethylsiloxy) dimethylsiloxy]methylsilane and bis[(phenyldimethylsiloxy)methylsiloxy]dimethylsilanol as the initiator core (GO-Ph) and the building block, respectively.
  • Muzafarov et al. (Polym. Sci., Ser. A, 1999, 41 , 283) report the synthesis of a hyperbranched polysiloxane from triethoxysilanol via a rapid, ammonia-catalyzed condensation process.
  • R is C ⁇ to Ci o hydrocarbyl or -H;
  • X 3 is X 2 or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; and n+p is 1, 2, or 3; provided either X 1 , or
  • the present invention is also directed to a method of preparing a hyperbranched polysiloxane, comprising reacting a difunctional silane having the formula R ⁇ HSiX ⁇ with at least one tetrafunctional silane having the formula X SiX 2 3 in the presence of a Lewis acid catalyst and, optionally, an organic solvent, wherein R* is C to Ci Q hydrocarbyl or -H;
  • X 3 is X 2 or -OH; and the mole ratio of the difunctional silane to the tetrafunctional silane is from 0.8:1 to 1.2:1; provided either ⁇ l, or X 2 and X 3 are -CI, -Br-, or -I, and when X 2 is -
  • X 3 is not -OH.
  • the present invention is also directed to a hyperbranched polysiloxane having the formula:
  • R is C ⁇ to Cjo hydrocarbyl or -H;
  • R 3 is C ⁇ to C ⁇ Q hydrocarbyl;
  • R 4 is R 3 , -H, or - (CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10;
  • R-> is R 3 or -H;
  • v is from 0 to 40 mol%;
  • w is from 0 to 40 mol%;
  • x is from 0 to 60 mol%;
  • y is from 0 to 60 mol%;
  • z is from 10 to 60 mol%; and the sum x+y is from 10 to 60 mol%.
  • the present invention is further directed to a method of preparing a hyperbranched polysiloxane, comprising reacting a hyperbranched polysiloxane having the formula:
  • R 1 is Ci to Cio hydrocarbyl or -H
  • R 3 is Cj to CJQ hydrocarbyl
  • R 4 is R 3 , H, or -(CH2) q -Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10
  • R is R 3 or -H
  • the present invention is still further directed to a method of preparing a hyperbranched polysiloxane, comprising reacting a hyperbranched polysiloxane having the formula:
  • R 1 is Ci to CJQ hydrocarbyl or -H
  • R 3 is Ci to Ci o hydrocarbyl
  • R 4 is R 3 , H, or -(CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10
  • Y is a divalent organic group
  • X 3 is X 2 or -OH
  • a is from 5 to 50 mol%
  • b is from 0.1 to 25 mol%
  • c is from 0.01 to 50 mol%
  • d is from 5 to 50 mol%
  • e is from 5 to 70 mol%
  • n is 0, 1, 2, or 3
  • p is 0 or 1
  • n+p is 1, 2, or 3
  • the hyperbranched polysiloxanes of the present invention contain a high concentration of silicon-bonded hydrogen atoms compared to known hyperbranched or dendritic polysiloxanes. Also, the hyperbranched polysiloxanes have lower viscosities than linear polysiloxanes of the same molecular weights and tend to be more soluble in organic solvents than linear analogues. Importantly, the hyperbranched polysiloxanes are hydrolytically stable and resistant to degradation by moisture. [0016] The hyperbranched polysiloxanes of the present invention are useful in the preparation of novel hyperbranched polysiloxanes containing various functional groups, introduced by hydrosilylation reactions, in place of hydrogen.
  • the hyperbranched polysiloxanes can be used in the preparation of hydrosilylation-curable silicone compositions further comprising a crosslinking agent having carbon-carbon double bonds, and a hydrosilylation catalyst.
  • the hyperbranched polysiloxanes containing reactive groups represented by ⁇ l, X 2 , and X 3 in addition to silicon-bonded hydrogen atoms, can be used in the formulation of condensation-curable silicone compositions.
  • the "mol%" of a siloxane unit in a hyperbranched polysiloxane is defined as the ratio of the number of moles of the siloxane unit to the total number of moles of siloxane units in the hyperbranched polysiloxane, multiplied by 100.
  • N- carbazolyl refers to a group having the formula:
  • a first hyperbranched polysiloxane according to the present invention has the formula:
  • R 1 is Ci to C ⁇ Q hydrocarbyl or -H
  • X 3 is X 2 or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; and n+p is 1, 2, or 3; provided either X 1 , or
  • the hydrocarbyl groups represented by R! typically have from 1 to 10 carbon atoms, alternatively from 1 to 6 carbon atoms.
  • Acyclic hydrocarbyl groups containing at least 3 carbon atoms can have a branched or unbranched structure.
  • hydrocarbyl groups include, but are not limited to, alkyl, such as methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, pentyl, 1-methylbutyl, 1- ethylpropyl, 2-methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl; cycloalkyl, such as cyclopentyl, cyclohexyl, and methylcyclohexyl; aryl, such as phenyl and nap
  • R 2 typically have from 1 to 8 carbon atoms, alternatively from 3 to 6 carbon atoms.
  • Acyclic hydrocarbyl and halogen-substituted hydrocarbyl groups containing at least 3 carbon atoms can have a branched or unbranched structure.
  • hydrocarbyl groups represented by R 2 include, but are not limited to, unbranched and branched alkyl, such as methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, pentyl, 1- methylbutyl, 1-ethylpropyl, 2-methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 2,2- dimethylpropyl, hexyl, heptyl, and octyl; cycloalkyl, such as cyclopentyl, cyclohexyl, and methylcyclohexyl; phenyl; alkaryl, such as tolyl and xylyl; aralkyl, such as benzyl and phenethyl; alkenyl, such as vinyl, allyl, and propenyl; arylalkenyl, such as s,
  • the divalent organic groups represented by Y typically have from 1 to 8 carbon atoms, alternatively from 2 to 6 carbon atoms. In addition to carbon and hydrogen, the divalent organic groups may contain other atoms such as nitrogen, oxygen, and halogen.
  • hydrocarbylene such as methylene, propylene, and phenylene
  • halogen-substituted hydrocarbylene such as chloroethylene and fluoroethylene
  • alkyleneoxyalkylene such as - CH2 ⁇ CH 2 CH 2 CH2-, -CH 2 CH 2 OCH2CH 2 -, -CH 2 CH 2 OCH(CH3)CH2-, and -
  • the subscript a typically has a value of from 5 to 50 mol%, alternatively from 20 to 50 mol%; the subscript b typically has a value of from 0.1 to 25 mol%, alternatively from 0.1 to 10 mol%; the subscript c typically has a value of from 0.01 to 50 mol%, alternatively from 0.1 to 30 mol%; the subscript d typically has a value of from 5 to 50 mol%, alternatively from 10 to 40 mol%; and the subscript e typically has a value of from 5 to 70 mol%, alternatively from 30 to 50 mol%.
  • the first hyperbranched polysiloxane typically has a number-average molecular weight of from 500 to 1,000,000, alternatively from 1,000 to 100,000, alternatively from 1,000 to 50,000, where the molecular weight is determined by gel permeation chromatography employing a low angle laser light scattering detector.
  • Examples of the first hyperbranched polysiloxane include, but are not limited to, polysiloxanes having the following average formulae:
  • Me is methyl
  • Et is ethyl
  • Ph is phenyl
  • i-PrO is isopropoxy
  • t-BuO is tert-butoxy
  • the numerical subscripts denote mole fractions.
  • R! and X 1 are as defined and exemplified above for the first hyperbranched polysiloxane.
  • difunctional silanes include, but are not limited to, dichloromethylsilane, dichlorosilane, dichloroethylsilane, dichlorophenylsilane, allyldichlorosilane, diiodosilane, and diisopropoxymethylsilane.
  • the difunctional silane can be a single silane or a mixture comprising two or more different silanes, each having the formula R ⁇ HSiX ⁇ , wherein R and ⁇ l are as defined and exemplified above for the first hyperbranched polysiloxane. Methods of preparing difunctional silanes are well known in the art; many of these silanes are commercially available.
  • the tetrafunctional silane is at least one silane having the formula X 3 SiX 2 3, wherein X 2 and X 3 are as defined and exemplified above for the first hyperbranched polysiloxane.
  • tetrafunctional silanes include, but are not limited to, tri-t- butoxysilanol, tetraisopropoxysilane, tetra-t-butoxysilane, tetrachlorosilane, tetraiodosilane, diacetoxy-di-t-butoxysilane, and tetrakis(methoxypropoxy)silane.
  • the tetrafunctional silane can be a single silane or a mixture comprising two or more different silanes each having the formula X 3 SiX 2 3, wherein X 2 and X 3 are as defined and exemplified above for the first hyperbranched polysiloxane.
  • Methods of preparing tetrafunctional silanes are well known in the art; many of these silanes are commercially available.
  • the Lewis acid catalyst is at least one Lewis acid catalyst capable of promoting a condensation reaction between the silicon-bonded groups X 1 in the difunctional silane and the silicon-bonded groups X 2 and X 3 in the tetrafunctional silane.
  • Lewis acid catalysts include, but are not limited to, catalysts having the following formulae: A1C1 3 , FeCl 3 , BC1 3 , and ZnCl 2 .
  • the Lewis acid catalyst can be a single Lewis acid catalyst or a mixture comprising two or more different Lewis acid catalysts.
  • the organic solvent can be any aprotic or dipolar aprotic organic solvent that does not react with the difunctional silane, the tetrafunctional silane, or the hyperbranched polysiloxane produced under the conditions of the present method, and is miscible with the difunctional silane, the tetrafunctional silane, and the hyperbranched polysiloxane.
  • organic solvents include, but are not limited to, saturated aliphatic hydrocarbons such as n-pentane, hexane, n-heptane, isooctane and dodecane; cycloaliphatic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; cyclic ethers such as tetrahydrofuran (THF) and dioxane; ketones such as methyl isobutyl ketone (MIBK); halogenated alkanes such as trichloroethane; and halogenated aromatic hydrocarbons such as bromobenzene and chlorobenzene.
  • saturated aliphatic hydrocarbons such as n-pentane, hexane, n-heptane, isooctane and dodecane
  • the organic solvent can be a single organic solvent or a mixture comprising two or more different organic solvents, each as defined above.
  • the reaction can be carried out in any standard reactor suitable for reacting halosilanes with alkoxysilanes or acyloxysilanes. Suitable reactors include glass and Teflon- lined glass reactors. Preferably, the reactor is equipped with a means of agitation, such as stirring.
  • the reaction can be carried out at atmospheric, subatmospheric, or supraatmospheric pressure. Preferably, the reaction is carried out in an inert atmosphere, such as nitrogen or argon, in the absence of moisture.
  • the difunctional silane, tetrafunctional silane, Lewis acid catalyst, and organic solvent can be combined in any order.
  • the Lewis acid catalyst is added to a mixture comprising the difunctional silane, tetrafunctional silane, and, optionally, organic solvent.
  • the reaction is typically carried out at a temperature of from room temperature ( ⁇ 23 °C) to 150 °C, alternatively from 40 tolOO °C.
  • the reaction is initially conducted at room temperature and then at an elevated temperature. When the temperature is less than room temperature, the rate of reaction is typically very slow. When the temperature is greater than 150 °C, volatile components may be lost from the reaction mixture.
  • the reaction is typically carried out for a period of time sufficient to achieve a constant viscosity of the reaction mixture. The reaction time depends on several factors, such as the structures of the difunctional silane, tetrafunctional silane, and Lewis acid, and the temperature. The time of reaction is typically from 2 to 48 h at a temperature of from room temperature to 150 °C.
  • the optimum reaction time can be readily determined by routine experimentation using the methods set forth in the Examples section below.
  • the mole ratio of the difunctional silane to the tetrafunctional silane is typically from 0.8:1 to 1.2:1, alternatively from 0.9:1 to 1.1:1.
  • the mole ratio of the difunctional silane to the tetrafunctional silane is less than 0.8:1 or greater than 1.2:1, the hyperbranched polysiloxane has a lower molecular weight.
  • the concentration of the Lewis acid catalyst is sufficient to catalyze the condensation reaction of the difunctional silane with the tetrafunctional silane.
  • concentration of the Lewis acid catalyst is from 0.1 to 3% (w/w), alternatively from 0.5 to 1%
  • the concentration of the organic solvent is typically from 0 to 50% (w/w), based on the total weight of the reaction mixture.
  • the first hyperbranched polysiloxane can be separated from volatile solvent and/or by-products by conventional methods of evaporation.
  • the reaction mixture can be heated under reduced pressure, or heated and purged with an inert gas, such as nitrogen.
  • the resulting product can be used without further purification in the preparation of the second hyperbranched polysiloxane, described below.
  • a second hyperbranched polysiloxane according to the present invention has the formula: (RlHSi ⁇ 2/2)v(R 1 Si ⁇ 3/2) w (R 3 2R 4 SiO 1 /2) x (R 2 R 5 SiO 1 /2) y (SiO 4 /2) z (II)
  • R 1 is Ci to CJQ hydrocarbyl or -H
  • R 3 is Ci to Ci Q hydrocarbyl
  • R 4 is R 3 , -H, or -
  • (CH2)n-Cz wherein Cz is N-carbazolyl and q is an integer from 2 to 10; R ⁇ is R 3 or -H; v is from 0 to 40 mol%; w is from 0 to 40 mol%; x is from 0 to 60 mol%; y is from 0 to 60 mol%; z is from 10 to 60 mol%; and the sum x+y is from 10 to 60 mol%.
  • R is as defined and exemplified above for the first hyperbranched polysiloxane.
  • hydrocarbyl groups represented by R 3 are as described and exemplified above for R 1 in the formula of the first hyperbranched polysiloxane.
  • carbazolylalkyl groups represented by R 4 having the formula -(CH2) ⁇ - Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10, include, but are not limited to, groups having the formulae: -CH2-CH2-CZ, -(CH2)3-Cz, -(CH2) 4 -Cz, -(CH2)6"Cz, and -
  • the subscript v typically has a value of from 0 to 40 mol%, alternatively from 5 to 25 mol%; the subscript w typically has a value of from 0 to 40 mol%, alternatively from 0 to 10 mol%; the subscript x typically has a value of from 0 to 60 mol%, alternatively from 0 to 50 mol%; the subscript y typically has a value of from 0 to 60 mol%, alternatively from 0 to 50 mol%; the subscript z typically has a value of from 10 to 60 mol%, alternatively from 20 to 50 mol%; and the sum x+y typically has a value of from 10 to 60 mol%; alternatively from 20 to 50 mol%.
  • the second hyperbranched polysiloxane typically has a number-average molecular weight of from 500 to 1,000,000, alternatively from 1,000 to 100,000, alternatively from
  • Examples of the second hyperbranched polysiloxane include, but are not limited to, polysiloxanes having the following average formulae:
  • the second hyperbranched polysiloxane can be prepared by reacting a hyperbranched polysiloxane having the formula:
  • R is C ⁇ to C ⁇ o hydrocarbyl or -H
  • R 3 is C to CJQ hydrocarbyl
  • R 4 is R 3 , H, or -(CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10
  • R ⁇ is R 3 or -H
  • Hyperbranched polysiloxane (I) is the first hyperbranched polysiloxane, described and exemplified above.
  • the endblocking agent is selected from at least one silane having the formula
  • R 3 2R SiX 4 at least one disiloxane having the formula (R 3 2R 4 SiO)2, at least one disilazane having the formula (R ⁇ R ⁇ Si ⁇ NH, and a mixture comprising at least two of the preceding agents, wherein R 3 , R 4 , and R are as described and exemplified above for the second hyperbranched polysiloxane, and X 4 is a hydrolysable group or -OH.
  • the term "hydrolysable group” means the silicon-bonded group X 4 can react with water to form a silicon-bonded -OH (silanol) group.
  • R 2 is C ⁇ to Cg hydrocarbyl or halogen-substituted hydrocarbyl and Y is a divalent organic group, as described and exemplified above.
  • Examples of silanes having the formula R 3 2R 4 SiX 4 , wherein R 3 and R 4 are as described and exemplified above for the second hyperbranched polysiloxane, and X 4 is a hydrolysable group or -OH, include, but are not limited to, chlorodimethylsilane, chlorotrimethylsilane, chloromethylphenylsilane, triethylsilanol, triphenylsilanol, allylchlorosilane, and acetoxydimethylsilane.
  • the silane can be a single silane or a mixture comprising two or more different silanes, each having the formula R 3 2R 4 SiX 4 , wherein R 3 , R 4 , and X 4 are as defined and exemplified above.
  • silane having the formula R 3 2R 4 SiX 4 wherein R 4 is -(CH2)q- Cz
  • R 4 is -(CH2)q- Cz
  • disiloxanes having the formula (R 2R 4 SiO)2, wherein R 3 and R 4 are as described and exemplified above for the second hyperbranched polysiloxane include, but are not limited to, 1,1,3,3-tetramethyldisiloxane, 1,1,3,3-tetraethyldisiloxane, 1,3-dimethyl- 1,3-diphenyldisiloxane, hexamethyldisiloxane, and pentamethyldisiloxane.
  • the disiloxane can be a single disiloxane or a mixture comprising two or more different disiloxanes, each having the formula (R 3 2 4 SiO)2, wherein R 3 and R 4 are as described and exemplified above for the second hyperbranched polysiloxane.
  • Methods of preparing disiloxanes are well known in the art; many of these disiloxanes are commercially available.
  • the disiloxane having the formula (R 2R 4 SiO)2, wherein R 4 is -(CH2)q-Cz, can be prepared by reacting a disiloxane having the formula
  • disilazanes having the formula (R 3 2R->Si)2NH, wherein R 3 and R ⁇ are as defined and exemplified above for the second hyperbranched polysiloxane include, but are not limited to, hexamethyldisilazane, tetramethyldisilazane, and pentamethyldisilazane.
  • the disilazane can be a single disilazane or a mixture comprising two or more different disilazanes, each having the formula (R- ⁇ R ⁇ Sf NH wherein R 3 and R ⁇ are as defined and exemplified above for the second hyperbranched polysiloxane. Methods of preparing disilazanes are well known in the art; many of these disilazanes are commercially available.
  • the endblocking agent can be a single endblocking agent selected from the silane, disiloxane, and disilazane, described above, or a mixture comprising at least two of the agents.
  • water-miscible organic solvent means the organic solvent is substantially miscible with water or completely miscible (i.e., miscible in all proportions) with water.
  • solubility of the water-miscible organic solvent in water is typically at least 90 g/100 g of water at 25 °C.
  • water-miscible organic solvents include, but are not limited to, monohydric alcohols such as methanol, ethanol, 1-propanol, and 2-propanol; dihydric alcohols such as ethylene glycol and propylene glycol; polyhydric alcohols such as glycerol and pentaerythritiol; and dipolar aproptic solvents such as N,N- dimethylformamide, tetrahydrofuran, dimethyl sulfoxide, and acetonitrile.
  • the water- miscible organic solvent can be a single water-miscible organic solvent or a mixture comprising two or more different water-miscible organic solvents, each as defined above.
  • the reaction mixture can further comprise a condensation catalyst.
  • hydrolysable group that does not react with water to form an acid means the hydrolysable group does not react with water in the absence of a catalyst at any temperature from room temperature to 100 °C within several minutes, for example thirty minutes, to form an acid.
  • the condensation catalyst can be any condensation catalyst typically used to promote condensation of silicon-bonded hydroxy (silanol) groups to form Si-O-Si linkages.
  • condensation catalysts include, but are not limited to, tin(II) and tin(IV) compounds such as tin dilaurate, tin dioctoate, and tetrabutyl tin; and titanium compounds such as titanium tetrabutoxide.
  • the concentration of the condensation catalyst is typically from 0.1 to 10% (w/w), alternatively from 0.5 to 5% (w/w), alternatively from 1 to 3% (w/w), based on the weight of the hyperbranched polysiloxane (I).
  • the reaction can be carried out in any standard reactor suitable for reacting halosilanes with disiloxanes or disilazanes in the presence of water.
  • Suitable reactors include glass and Teflon-lined glass reactors.
  • the reactor is equipped with a means of agitation, such as stirring.
  • the reaction can be carried out at atmospheric, subatmospheric, or supraatmospheric pressure.
  • the reaction is carried out in an inert atmosphere, such as nitrogen or argon.
  • water is added slowly to a mixture comprising the hyperbranched polysiloxane, the endblocking agent, and the water-miscible organic solvent.
  • the reaction is typically carried out at a temperature of from 0 to 100 °C, alternatively from room temperature ( ⁇ 23 °C) to 80 °C. When the temperature is less than 0 °C, the rate of reaction is typically very slow. When the temperature is greater than 100 °C, the Si-H groups in the hyperbranched polysiloxane may be converted into silanol groups (Si- OH).
  • the reaction is typically carried out for a period of time sufficient to complete the condensation reaction between the hyperbranched polysiloxane (I) and the endblocking agent.
  • complete the condensation reaction means the hyperbranched polysiloxane product does not contain silicon-bonded groups X 1 , X 2 , or X 3 , as determined by NMR.
  • the reaction time depends on several factors, such as the structures of the hyperbranched polysiloxane (I) and the endblocking agent, and the temperature.
  • the time of reaction is typically from 2 to 48 h at a temperature of from 0 to 100 °C. The optimum reaction time can be readily determined by routine experimentation using the methods set forth in the Examples section below.
  • the mole ratio of the endblocking agent to the silicon-bonded groups X 2 in the hyperbranched polysiloxane (I) is typically from 1:1 to 2:1, alternatively from 1.1:1 to 1.5:1.
  • the concentration of water in the reaction mixture depends on the nature of X 1 , X 2 , and X 3 , and the structure of the endblocking agent.
  • the concentration of water is typically from 0.5 to 10% (w/w), alternatively from 1 to 3% (w/w), based on the total weight of the reaction mixture.
  • the endblocking agent has the formula R 2R 4 SiX 4 , wherein X 4 is -
  • the water-miscible organic solvent is present in an effective amount in the reaction mixture.
  • the term "effective amount” means the concentration of the water- miscible solvent is such that the hyperbranched polysiloxane (I) and the endblocking agent are soluble in the reaction mixture containing the water-miscible organic solvent.
  • the concentration of the water-miscible organic solvent is typically from about 50 to 99% (w/w), alternatively from 50 to 90% (w/w), alternatively from 60 to 80% (w/w), based on the total weight of the reaction mixture.
  • the effective amount of the water-miscible organic solvent can be determined by routine experimentation using the methods in the Examples section below.
  • the second hyperbranched polysiloxane can be recovered from the reaction mixture by filtering the mixture to remove any Lewis acid catalyst introduced into the reaction mixture from the hyperbranched polysiloxane (I), and then evaporating the volatile solvent and or by-products. Conventional methods of evaporation can be used. For example, the mixture can be heated under reduced pressure, or heated and purged with an inert gas, such as nitrogen.
  • the second hyperbranched polysiloxane wherein the subscript y has a value of 0, can also be prepared by reacting a hyperbranched polysiloxane having the formula:
  • R 1 is C ⁇ to C Q hydrocarbyl or -H
  • R 3 is Ci to Ci o hydrocarbyl
  • R 4 is R 3 , H, or -(CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10
  • Y is a divalent organic group
  • X 3 is X 2 or -OH
  • a is from 5 to 50 mol%
  • b is from 0.1 to 25 mol%
  • c is from 0.01 to 50 mol%
  • d is from 5 to 50 mol%
  • e is from 5 to 70 mol%
  • n is 0, 1, 2, or 3
  • p is 0 or 1
  • n+p is 1, 2, or 3
  • Hyperbranched polysiloxane (I) is the first hyperbranched polysiloxane, described and exemplified above.
  • the Lewis acid catalyst and organic solvent are as described and exemplified above in the method of preparing the first hyperbranched polysiloxane. Because, the Lewis acid catalyst used to prepare hyperbranched polysiloxane (I) is typically not removed from the preparation, it can also be used as the Lewis acid catalyst in the present method.
  • endblocking agents having the formula R 3 2R 4 Si ⁇ 5, wherein R 3 , R 4 , and ⁇ 5 are as defined and exemplified above, include, but are not limited to, chlorodimethylsilane, chlorotrimethylsilane, chloromethylphenylsilane, allylchlorosilane, acetoxydimethylsilane, isopropoxydimethylsilane, and t-butoxydimethylsilane.
  • the endblocking agent can be a single silane or a mixture comprising two or more different silanes, each having the formula R 3 2R 4 Si ⁇ 5, w herein R 3 , R 4 , and X ⁇ are as defined and exemplified above. Methods of preparing silanes having the preceding formula are well known in the art; many of these silanes are commercially available.
  • the reaction can be carried out in any standard reactor suitable for reacting halosilanes with alkoxysilanes or acyloxysilanes. Suitable reactors include glass and Teflon- lined glass reactors. Preferably, the reactor is equipped with a means of agitation, such as stirring.
  • the reaction can be carried out at atmospheric, subatmospheric, or supraatmospheric pressure. Also, preferably, the reaction is carried out in an inert atmosphere, such as nitrogen or argon, in the absence of moisture.
  • the hyperbranched polysiloxane (I), endblocking agent, Lewis acid catalyst, and organic solvent can be combined in any order.
  • the Lewis acid catalyst is added to a mixture comprising the hyperbranched polysiloxane (I), endblocking agent, and, optionally, organic solvent.
  • the reaction is typically carried out at a temperature of from 0 to 100 °C, alternatively from room temperature ( ⁇ 23 °C) to 80 °C. When the temperature is less than 0 °C, the rate of reaction is typically very slow.
  • the reaction is typically carried out for a period of time sufficient to complete the condensation reaction between the hyperbranched polysiloxane (I) and the endblocking agent.
  • complete the condensation reaction means the hyperbranched polysiloxane product does not contain silicon-bonded groups X 1 , X 2 , or X 3 , as determined by NMR.
  • the reaction time depends on several factors, such as the structures of the hyperbranched polysiloxane (I) and the endblocking agent, and the temperature.
  • the time of reaction is typically from 2 to 48 h at a temperature of from 0 to 100 °C. The optimum reaction time can be readily determined by routine experimentation using the methods set forth in the Examples section below.
  • the mole ratio of the endblocking agent to the silicon-bonded groups X 2 in the hyperbranched polysiloxane (I) is typically from 1:1 to 2:1, alternatively from 1.1:1 to 1.5:1.
  • the concentration of the Lewis acid catalyst is sufficient to catalyze the condensation reaction between the hyperbranched polysiloxane (I) and the endblocking agent.
  • the concentration of the Lewis acid catalyst is from 0.1 to 3% (w/w), alternatively from 0.5 to 1% (w/w), based on the combined weight of the hyperbranched polysiloxane (I) and the endblocking agent.
  • the concentration of the organic solvent is typically from 0 to 50% (w/w), alternatively from 0 to 10% (w/w), based on the total weight of the reaction mixture.
  • the second hyperbranched polysiloxane can be recovered from the reaction mixture by adding sufficient quantity of water to effect precipitation of the Lewis acid catalyst, extracting the hyperbranched polysiloxane with an organic solvent, and removing the organic solvent from the extract.
  • the organic solvent can be removed using conventional methods of evaporation.
  • the mixture can be heated under reduced pressure or heated and purged with an inert gas, such as nitrogen.
  • the reaction mixture can be filtered to remove the Lewis acid precipitate before extraction.
  • Example of organic solvents include, but are not limited to, saturated aliphatic hydrocarbons such as n-pentane, hexane, and n-heptane; cycloaliphatic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; and halogenated aromatic hydrocarbons such as bromobenzene and chlorobenzene.
  • saturated aliphatic hydrocarbons such as n-pentane, hexane, and n-heptane
  • cycloaliphatic hydrocarbons such as cyclopentane and cyclohexane
  • aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene
  • halogenated aromatic hydrocarbons such as bromobenzene and chlorobenzene.
  • the hyperbranched polysiloxanes have lower viscosities than linear polysiloxanes of the same molecular weights and tend to be more soluble in organic solvents than linear analogues. Importantly, the hyperbranched polysiloxanes are hydrolytically stable and resistant to degradation by moisture. [0087]
  • the hyperbranched polysiloxanes of the present invention are useful in the preparation of novel hyperbranched polysiloxanes containing various functional groups, introduced by hydrosilylation reactions, in place of hydrogen.
  • the hyperbranched polysiloxanes can be used in the preparation of hydrosilylation-curable silicone compositions further comprising a crosslinking agent having carbon-carbon double bonds, and a hydrosilylation catalyst.
  • the hyperbranched polysiloxanes containing reactive groups represented by X 1 , X 2 , and X 3 in addition to silicon-bonded hydrogen atoms, can be used in the formulation of condensation-curable silicone compositions.
  • M n and M w Number-average and weight-average molecular weights (M n and M w ) of hyperbranched polysiloxanes were determined by gel permeation chromatography (GPC) using a PLgel (Polymer Laboratories, Inc.) 5- ⁇ m column at room temperature ( ⁇ 23 °C), a THF mobile phase at 1 mL/min, and a refractive index detector. Polystyrene standards were used for linear regression calibrations.
  • a portion (3 g) of the resulting viscous fluid, 2.5 g of chlorodimethylsilane, and 10 ml of tetrahydrofuran (THF) were combined in a glass vial.
  • Water (0.5 g) was added to the mixture and the vial was sealed with a cap and kept at room temperature overnight. Most of the THF was evaporated by directing a stream of air across the surface of the mixture to produce a viscous fluid.
  • the mixture was heated under nitrogen successively at 60 °C for 1 h and 120 °C for 2 h to produce 14.5 g of a slightly cloudy viscous fluid.
  • the viscous fluid was dissolved in 100 ml of THF and the solution was treated with 10 ml of chlorodimethylsilane.
  • Water (0.4 g) was added to the flask drop- wise under vigorous stirring to dissipate heat and the flask was kept at room temperature overnight, during which time a white precipitate formed. Most of the THF was removed by venting the flask, continuously purging the system with a stream of air, and heating the mixture at 60 °C.
  • the resulting viscous fluid solidified at low temperature (below 0 °C) after the solvent was completely evaporated.
  • the hyperbranched polysiloxane product had a number-average molecular weight and a weight-average molecular weight of 1885 and 3413, respectively.
  • the composition of the product, as determined by Si NMR, was H o.57D H 0.53T ⁇ .5Q-
  • THF anhydrous tetrahydrofuran
  • the filtrate was treated with 0.1 g of anhydrous aluminum trichloride under nitrogen and the mixture was kept at room temperature overnight in a closed flask. The mixture was heated at 60 °C for 1 h and at 120 °C for 2 h under nitrogen to produce a viscous fluid.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Silicon Polymers (AREA)

Abstract

Hyperbranched polysiloxanes containing pendant silicon-bonded hydrogen atoms and methods for the preparation thereof.

Description

[0001] HYPERBRANCHED POLYSILOXANES
FIELD OF THE INVENTION [0002] The present invention relates to hyperbranched polysiloxanes and more particularly to hyperbranched polysiloxanes containing pendant silicon-bonded hydrogen atoms.
BACKGROUND OF THE INVENTION [0003] Only a small number of hyperbranched polysiloxanes containing repeating Si-O-Si linkages are known in the art. For example, Kazakova et al. (Polym. Prepr., 1998, 39(1), 483-484) reported the synthesis of hyperbranched polyethylsilicates, which were hydrolyzed to silica sols and finally converted to silica particles.
[0004] U.S. Patent No. 6,284,906 B 1 to Paulasaari et al. discloses methods for the preparation of hyperbranched siloxane polymers by anionic polymerization of a cyclotrisiloxane having the functional group Si-OH.
[0005] Morikawa et al. (Macromolecules, 1991, 24(12), 3469-3474) describe the synthesis of highly branched polysiloxane starburst polymers starting from tris[(phenyldimethylsiloxy) dimethylsiloxy]methylsilane and bis[(phenyldimethylsiloxy)methylsiloxy]dimethylsilanol as the initiator core (GO-Ph) and the building block, respectively. [0006] Muzafarov et al. (Polym. Sci., Ser. A, 1999, 41 , 283) report the synthesis of a hyperbranched polysiloxane from triethoxysilanol via a rapid, ammonia-catalyzed condensation process.
[0007] Rebrov et al. (Dokl. Akad. Nauk. SSSR, 1989, 309(2), 376-380) describe the preparation of dendritic silsesquioxane oligomers by reaction of MeSiC_3 with
(ETO)2MeSiONa and subsequently with SOCI2 to replace OET groups with reactive CI groups. Repeated treatment of the product with MeSiCl3 and (ETO)2MeSiONa gave products having <46 Si atoms and functionality (OET or CI) <48.
[0008] Uchida et al. (J. Am. Chem. Soc, 1990, 112(19), 7077-7079) report a general strategy for the synthesis of silicone dendrimers having terminal SiH groups and molecular weights >10,000.
[0009] Although, the aforementioned references disclose hyperbranched polysiloxanes, they do not disclose the hyperbranched polysiloxanes of the present invention having pendant silicon-bonded hydrogen atoms. SUMMARY OF THE INVENTION [0010] The present invention is directed to a hyperbranched polysiloxane having the formula:
(RlHSiθ2/2)a(R1HX1SiOι/2)b(R1Siθ3/2)c(Siθ4/2)d(X2nX3pSiO(4.n.p)/2)e (I)
wherein R is C\ to Ci o hydrocarbyl or -H; X* and X2 are independently -CI, -Br, -I, - O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is Ci to Cg hydrocarbyl or halogen- substituted hydrocarbyl and Y is a divalent organic group; X3 is X2 or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; and n+p is 1, 2, or 3; provided either X1, or
X2 and X3 are -CI, -Br, or -I, and when X2 is -CI, -Br, -I, or -O(O=)CR2, X3 is not -OH. [0011] The present invention is also directed to a method of preparing a hyperbranched polysiloxane, comprising reacting a difunctional silane having the formula R^HSiX^ with at least one tetrafunctional silane having the formula X SiX23 in the presence of a Lewis acid catalyst and, optionally, an organic solvent, wherein R* is C to Ci Q hydrocarbyl or -H;
X d X2 are independently -CI, -Br, -I, -O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is C\ to Cg hydrocarbyl or halogen-substituted hydrocarbyl and Y is a divalent organic group;
X3 is X2 or -OH; and the mole ratio of the difunctional silane to the tetrafunctional silane is from 0.8:1 to 1.2:1; provided either χl, or X2 and X3 are -CI, -Br-, or -I, and when X2 is -
CI, -Br, -I, or -O(O=)CR2, X3 is not -OH.
[0012] The present invention is also directed to a hyperbranched polysiloxane having the formula:
(RlHSiθ2/2)v(R1Siθ3/2)w(R32R4SiO1/2)x(R32R5SiO1/2)y(SiO4/2)z (H)
wherein R is C\ to Cjo hydrocarbyl or -H; R3 is C\ to C\Q hydrocarbyl; R4 is R3, -H, or - (CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10; R-> is R3 or -H; v is from 0 to 40 mol%; w is from 0 to 40 mol%; x is from 0 to 60 mol%; y is from 0 to 60 mol%; z is from 10 to 60 mol%; and the sum x+y is from 10 to 60 mol%.
[0013] The present invention is further directed to a method of preparing a hyperbranched polysiloxane, comprising reacting a hyperbranched polysiloxane having the formula:
(RlHSiO2/2)a(R1HχlSiO1/2)b(R1Siθ3/2)c(Siθ4/2)d(X2 nX pSiO(4.n.p)/2)e (I)
with an endblocking agent selected from at least one silane having the formula R^R^SiX4- at least one disiloxane having the formula (R32R4SiO)2, at least one disilazane having the formula (R^R^Sf^NH, and a mixture comprising at least two of the preceding agents, in the presence of water and an effective amount of a water-miscible organic solvent, wherein R1 is Ci to Cio hydrocarbyl or -H; R3 is Cj to CJQ hydrocarbyl; R4 is R3, H, or -(CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10; R is R3 or -H; X and X2 are independently -CI, -Br, -I, -O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is C\ to Cg hydrocarbyl or halogen-substituted hydrocarbyl and Y is a divalent organic group; X3 is X2 or -OH; X4 is a hydroly sable group or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; n+p is 1, 2, or 3; and the mole ratio of the endblocking agent to the silicon-bonded groups X2 in the hyperbranched polysiloxane (I) is from 1:1 to 2:1; provided either X1, or X2 and X3 are -CI, -Br, or -I, and when X2 is -CI, -Br, -I, or -O(O=)CR2, X3 is not -OH.
[0014] The present invention is still further directed to a method of preparing a hyperbranched polysiloxane, comprising reacting a hyperbranched polysiloxane having the formula:
(RlHSiθ2/2)a(R1HX1SiOι/2)b(R1Siθ3/2)c(Siθ4/2)d(X2nX3pSiO(4.n.p)/2)e (I)
with an endblocking agent having the formula R32R4SiX^ m fhe presence of a Lewis acid catalyst and, optionally, an organic solvent, wherein R1 is Ci to CJQ hydrocarbyl or -H; R3 is Ci to Ci o hydrocarbyl; R4 is R3, H, or -(CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10; X1, X2, and X5 are independently -CI, -Br, -I, -O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is C\ to Cg hydrocarbyl or halogen-substituted hydrocarbyl and
Y is a divalent organic group; X3 is X2 or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; n+p is 1, 2, or 3; and the mole ratio of the endblocking agent to the silicon-bonded groups X2 in the hyperbranched polysiloxane (I) is from 1 : 1 to 2: 1 ; provided either X1, or X2 and X3 are -CI, -Br, or -I, when X2 is -CI, -Br, -I, or -O(O=)CR2, X3 is not -OH, and either X2 or X5 is -CI, -Br, or -I.
[0015] The hyperbranched polysiloxanes of the present invention contain a high concentration of silicon-bonded hydrogen atoms compared to known hyperbranched or dendritic polysiloxanes. Also, the hyperbranched polysiloxanes have lower viscosities than linear polysiloxanes of the same molecular weights and tend to be more soluble in organic solvents than linear analogues. Importantly, the hyperbranched polysiloxanes are hydrolytically stable and resistant to degradation by moisture. [0016] The hyperbranched polysiloxanes of the present invention are useful in the preparation of novel hyperbranched polysiloxanes containing various functional groups, introduced by hydrosilylation reactions, in place of hydrogen. Also, the hyperbranched polysiloxanes can be used in the preparation of hydrosilylation-curable silicone compositions further comprising a crosslinking agent having carbon-carbon double bonds, and a hydrosilylation catalyst. Furthermore, the hyperbranched polysiloxanes containing reactive groups represented by χl, X2, and X3, in addition to silicon-bonded hydrogen atoms, can be used in the formulation of condensation-curable silicone compositions. [0017] These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description and appended claims. DETAILED DESCRIPTION OF THE INVENTION [0018] As used herein, the "mol%" of a siloxane unit in a hyperbranched polysiloxane is defined as the ratio of the number of moles of the siloxane unit to the total number of moles of siloxane units in the hyperbranched polysiloxane, multiplied by 100. Also, the term "N- carbazolyl" refers to a group having the formula:
Figure imgf000006_0001
[0019] A first hyperbranched polysiloxane according to the present invention has the formula:
(RlHSiθ2/2)a(R1HχlSiOι/2)b(R1Siθ3/2)c(SiO4/2)d(X2 nX pSiO(4.I1.p)/2)e (I)
wherein R1 is Ci to C^Q hydrocarbyl or -H; X and X2 are independently -CI, -Br, -I, - O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is Ci to Cg hydrocarbyl or halogen- substituted hydrocarbyl and Y is a divalent organic group; X3 is X2 or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; and n+p is 1, 2, or 3; provided either X1, or
X2 and X3 are -CI, -Br, or -I, and when X2 is -CI, -Br, -I, or -O(O=)CR2, X3 is not -OH.
[0020] The hydrocarbyl groups represented by R! typically have from 1 to 10 carbon atoms, alternatively from 1 to 6 carbon atoms. Acyclic hydrocarbyl groups containing at least 3 carbon atoms can have a branched or unbranched structure. Examples of hydrocarbyl groups include, but are not limited to, alkyl, such as methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, pentyl, 1-methylbutyl, 1- ethylpropyl, 2-methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 2,2-dimethylpropyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, and octadecyl; cycloalkyl, such as cyclopentyl, cyclohexyl, and methylcyclohexyl; aryl, such as phenyl and naphthyl; alkaryl, such as tolyl and xylyl; aralkyl, such as benzyl and phenethyl; alkenyl, such as vinyl, allyl, and propenyl; arylalkenyl, such as styryl and cinnamyl; and alkynyl, such as ethynyl and propynyl. [0021] The hydrocarbyl groups and halogen-substituted hydrocarbyl groups represented by
R2 typically have from 1 to 8 carbon atoms, alternatively from 3 to 6 carbon atoms. Acyclic hydrocarbyl and halogen-substituted hydrocarbyl groups containing at least 3 carbon atoms can have a branched or unbranched structure. Examples of hydrocarbyl groups represented by R2 include, but are not limited to, unbranched and branched alkyl, such as methyl, ethyl, propyl, 1-methylethyl, butyl, 1-methylpropyl, 2-methylpropyl, 1,1-dimethylethyl, pentyl, 1- methylbutyl, 1-ethylpropyl, 2-methylbutyl, 3-methylbutyl, 1,2-dimethylpropyl, 2,2- dimethylpropyl, hexyl, heptyl, and octyl; cycloalkyl, such as cyclopentyl, cyclohexyl, and methylcyclohexyl; phenyl; alkaryl, such as tolyl and xylyl; aralkyl, such as benzyl and phenethyl; alkenyl, such as vinyl, allyl, and propenyl; arylalkenyl, such as styryl; and alkynyl, such as ethynyl and propynyl. Examples of halogen-substituted hydrocarbyl groups represented by R2 include, but are not limited to, 3,3,3-trifluoropropyl, 3- chloropropyl, chlorophenyl, and dichlorophenyl.
[0022] The divalent organic groups represented by Y typically have from 1 to 8 carbon atoms, alternatively from 2 to 6 carbon atoms. In addition to carbon and hydrogen, the divalent organic groups may contain other atoms such as nitrogen, oxygen, and halogen. Examples of divalent organic groups represented by Y include, but are not limited to, hydrocarbylene such as methylene, propylene, and phenylene; halogen-substituted hydrocarbylene such as chloroethylene and fluoroethylene; and alkyleneoxyalkylene such as - CH2θCH2CH2CH2-, -CH2CH2OCH2CH2-, -CH2CH2OCH(CH3)CH2-, and - CH2OCH2CH2OCH2CH2-, and carbonyloxyalkylene, such as -C(=O)O-(CH2)3-. [0023] In formula (I), the subscript a typically has a value of from 5 to 50 mol%, alternatively from 20 to 50 mol%; the subscript b typically has a value of from 0.1 to 25 mol%, alternatively from 0.1 to 10 mol%; the subscript c typically has a value of from 0.01 to 50 mol%, alternatively from 0.1 to 30 mol%; the subscript d typically has a value of from 5 to 50 mol%, alternatively from 10 to 40 mol%; and the subscript e typically has a value of from 5 to 70 mol%, alternatively from 30 to 50 mol%.
[0024] The first hyperbranched polysiloxane typically has a number-average molecular weight of from 500 to 1,000,000, alternatively from 1,000 to 100,000, alternatively from 1,000 to 50,000, where the molecular weight is determined by gel permeation chromatography employing a low angle laser light scattering detector. [0025] Examples of the first hyperbranched polysiloxane include, but are not limited to, polysiloxanes having the following average formulae:
(MeHSiθ2/2)θ.3( eHClSiOι/2)o.05( eSiO3/2)o.l(Siθ4/2)θ.05(t-BuOSiθ3/2)o.08 ((t-
BuO)2Siθ2/2)θ.l2((t-BuO)3SiO1/2)o.3,
(EtHSiθ2/2)θ.3(EtHClSiOι/2)o.05(EtSiθ3/2)o.l(SiO4/2)o.θ5(t-BuOSiθ3/2)o.08 ((t-
BuO)2SiO2/2)θ.l2( -BuO)3SiOι/2)o.3,
(PhHSiθ2/2)θ.25(PhHClSiOι/2)o.05(PhSiθ3/2)o.l(Siθ4/2)o.05(t-BuOSiO3/2)o.l ((t-
BuO)2Siθ2/2)θ.l5((t-BuO)3SiO1/2)o.33
(H2Siθ2/2)0.3(H2ClSiO1/2)0.05(HSiθ3/2)0.l(SiO4/2)0.05(t-BuOSiθ3/2)0.08 ((t-
BuO)2Siθ2/2)θ.l2((t-BuO)3SiO1/2)o.3,
(MeHSiθ2/2)θ.3( eHClSiOι/2)o.05(MeSiθ3/2)o.l(Siθ4/2)o.05(i-PrOSiO3/2)o.08 ((i-
PrO)2Siθ2/2)θ.l2((i-PrO)3SiOι/2)o.3.
(EtHSiθ2/2)θ.3(EtHClSiO1/2)o.05(EtSiθ3/2)o.l(SiO4/2)o.05 -PrOSiθ3/2)o.08 ((i-
PrO)2SiO2/2)0.12((i-PrO)3SiOι/2)0.3,
(PhHSiθ2/2)0.3(PhHClSiOι/2)0.05(PhSiO3/2)0.l(SiO4/2)0.05(i-PrOSiθ3/2)0.08 ((i-
PrO)2SiO2/2)0.12((i-PrO)3SiO1/2)0.3J
(H2Siθ2/2)0.3(H2ClSiO1/2)0.05(HSiθ3/2)0.l(SiO4/2)0.05(i-PrOSiO3/2)0.08 ((i-
PrO)2Siθ2/2)θ.l2((i"PrC)3SiOι/2)o.3. wherein Me is methyl, Et is ethyl, Ph is phenyl, i-PrO is isopropoxy, t-BuO is tert-butoxy, and the numerical subscripts denote mole fractions.
[0026] The first hyperbranched polysiloxane can be prepared by reacting a difunctional silane having the formula R^HSiX^ with at least one tetrafunctional silane having the formula X3SiX23 in the presence of a Lewis acid catalyst and, optionally, an organic solvent, wherein R is C to Ci o hydrocarbyl or -H; x d X2 are independently -CI, -Br, -I, - O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is C to Cg hydrocarbyl or halogen- substituted hydrocarbyl and Y is a divalent organic group; X3 is X2 or -OH; and the mole ratio of the difunctional silane to the tetrafunctional silane is from 0.8:1 to 1.2:1; provided either X1, or X2 and X3 are -CI, -Br-, or -I, and when X2 is -CI, -Br, -I, or -O(O=)CR2 X3 is not -OH. [0027] The difunctional silane is at least one silane having the formula R^HSiX^, wherein
R! and X1 are as defined and exemplified above for the first hyperbranched polysiloxane. [0028] Examples of difunctional silanes include, but are not limited to, dichloromethylsilane, dichlorosilane, dichloroethylsilane, dichlorophenylsilane, allyldichlorosilane, diiodosilane, and diisopropoxymethylsilane. [0029] The difunctional silane can be a single silane or a mixture comprising two or more different silanes, each having the formula R^HSiX^, wherein R and χl are as defined and exemplified above for the first hyperbranched polysiloxane. Methods of preparing difunctional silanes are well known in the art; many of these silanes are commercially available.
[0030] The tetrafunctional silane is at least one silane having the formula X3SiX23, wherein X2 and X3 are as defined and exemplified above for the first hyperbranched polysiloxane.
[0031] Examples of tetrafunctional silanes include, but are not limited to, tri-t- butoxysilanol, tetraisopropoxysilane, tetra-t-butoxysilane, tetrachlorosilane, tetraiodosilane, diacetoxy-di-t-butoxysilane, and tetrakis(methoxypropoxy)silane.
[0032] The tetrafunctional silane can be a single silane or a mixture comprising two or more different silanes each having the formula X3SiX23, wherein X2 and X3 are as defined and exemplified above for the first hyperbranched polysiloxane. Methods of preparing tetrafunctional silanes are well known in the art; many of these silanes are commercially available.
[0033] The Lewis acid catalyst is at least one Lewis acid catalyst capable of promoting a condensation reaction between the silicon-bonded groups X1 in the difunctional silane and the silicon-bonded groups X2 and X3 in the tetrafunctional silane. Examples of Lewis acid catalysts include, but are not limited to, catalysts having the following formulae: A1C13, FeCl3, BC13, and ZnCl2. The Lewis acid catalyst can be a single Lewis acid catalyst or a mixture comprising two or more different Lewis acid catalysts.
[0034] The organic solvent can be any aprotic or dipolar aprotic organic solvent that does not react with the difunctional silane, the tetrafunctional silane, or the hyperbranched polysiloxane produced under the conditions of the present method, and is miscible with the difunctional silane, the tetrafunctional silane, and the hyperbranched polysiloxane. [0035] Examples of organic solvents include, but are not limited to, saturated aliphatic hydrocarbons such as n-pentane, hexane, n-heptane, isooctane and dodecane; cycloaliphatic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; cyclic ethers such as tetrahydrofuran (THF) and dioxane; ketones such as methyl isobutyl ketone (MIBK); halogenated alkanes such as trichloroethane; and halogenated aromatic hydrocarbons such as bromobenzene and chlorobenzene. The organic solvent can be a single organic solvent or a mixture comprising two or more different organic solvents, each as defined above. [0036] The reaction can be carried out in any standard reactor suitable for reacting halosilanes with alkoxysilanes or acyloxysilanes. Suitable reactors include glass and Teflon- lined glass reactors. Preferably, the reactor is equipped with a means of agitation, such as stirring. The reaction can be carried out at atmospheric, subatmospheric, or supraatmospheric pressure. Preferably, the reaction is carried out in an inert atmosphere, such as nitrogen or argon, in the absence of moisture.
[0037] The difunctional silane, tetrafunctional silane, Lewis acid catalyst, and organic solvent can be combined in any order. Typically, the Lewis acid catalyst is added to a mixture comprising the difunctional silane, tetrafunctional silane, and, optionally, organic solvent.
[0038] The reaction is typically carried out at a temperature of from room temperature (~23 °C) to 150 °C, alternatively from 40 tolOO °C. Typically, the reaction is initially conducted at room temperature and then at an elevated temperature. When the temperature is less than room temperature, the rate of reaction is typically very slow. When the temperature is greater than 150 °C, volatile components may be lost from the reaction mixture. [0039] The reaction is typically carried out for a period of time sufficient to achieve a constant viscosity of the reaction mixture. The reaction time depends on several factors, such as the structures of the difunctional silane, tetrafunctional silane, and Lewis acid, and the temperature. The time of reaction is typically from 2 to 48 h at a temperature of from room temperature to 150 °C. The optimum reaction time can be readily determined by routine experimentation using the methods set forth in the Examples section below. [0040] The mole ratio of the difunctional silane to the tetrafunctional silane is typically from 0.8:1 to 1.2:1, alternatively from 0.9:1 to 1.1:1. When the mole ratio of the difunctional silane to the tetrafunctional silane is less than 0.8:1 or greater than 1.2:1, the hyperbranched polysiloxane has a lower molecular weight.
[0041] The concentration of the Lewis acid catalyst is sufficient to catalyze the condensation reaction of the difunctional silane with the tetrafunctional silane. Typically, the concentration of the Lewis acid catalyst is from 0.1 to 3% (w/w), alternatively from 0.5 to 1%
(w/w), based on the combined weight of the difunctional silane and the tetrafunctional silane.
[0042] The concentration of the organic solvent is typically from 0 to 50% (w/w), based on the total weight of the reaction mixture.
[0043] The first hyperbranched polysiloxane can be separated from volatile solvent and/or by-products by conventional methods of evaporation. For example the reaction mixture can be heated under reduced pressure, or heated and purged with an inert gas, such as nitrogen.
The resulting product can be used without further purification in the preparation of the second hyperbranched polysiloxane, described below.
[0044] A second hyperbranched polysiloxane according to the present invention has the formula: (RlHSiθ2/2)v(R1Siθ3/2)w(R32R4SiO1/2)x(R 2R5SiO1/2)y(SiO4/2)z (II)
wherein R1 is Ci to CJQ hydrocarbyl or -H; R3 is Ci to Ci Q hydrocarbyl; R4 is R3, -H, or -
(CH2)n-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10; R^ is R3 or -H; v is from 0 to 40 mol%; w is from 0 to 40 mol%; x is from 0 to 60 mol%; y is from 0 to 60 mol%; z is from 10 to 60 mol%; and the sum x+y is from 10 to 60 mol%.
[0045] In formula (II), R is as defined and exemplified above for the first hyperbranched polysiloxane. Examples of hydrocarbyl groups represented by R3 are as described and exemplified above for R1 in the formula of the first hyperbranched polysiloxane. [0046] Examples of carbazolylalkyl groups represented by R4 having the formula -(CH2)π- Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10, include, but are not limited to, groups having the formulae: -CH2-CH2-CZ, -(CH2)3-Cz, -(CH2)4-Cz, -(CH2)6"Cz, and -
(CH2)8-Cz.
[0047] Also, in formula (II), the subscript v typically has a value of from 0 to 40 mol%, alternatively from 5 to 25 mol%; the subscript w typically has a value of from 0 to 40 mol%, alternatively from 0 to 10 mol%; the subscript x typically has a value of from 0 to 60 mol%, alternatively from 0 to 50 mol%; the subscript y typically has a value of from 0 to 60 mol%, alternatively from 0 to 50 mol%; the subscript z typically has a value of from 10 to 60 mol%, alternatively from 20 to 50 mol%; and the sum x+y typically has a value of from 10 to 60 mol%; alternatively from 20 to 50 mol%.
[0048] The second hyperbranched polysiloxane typically has a number-average molecular weight of from 500 to 1,000,000, alternatively from 1,000 to 100,000, alternatively from
1,000 to 50,000, where the molecular weight is determined by gel permeation chromatography employing a low angle laser light scattering detector.
[0049] Examples of the second hyperbranched polysiloxane include, but are not limited to, polysiloxanes having the following average formulae:
(MeHSiO2/2)0.2( eSiO3/2)0.05( e2HSiOi/2)0.45(SiO4/2)0.35
(EtHSiO2/2)0.2(EtSiO3/2)0.05(Me2HSiO1/2)0.45(SiO /2)0.3,
(PhHSiθ2/2)θ.2(PhSiθ3/2)o.05( e2HSiO1/2)o.45(SiO4/2)θ.35
(MeHSiθ2/2)θ.2( eSiθ3/2)o.05(Ph eHSiOι/2)o.45(SiO4/2)o.35
(H2Siθ2/2)0.15(HSiθ3/2)0.05(Me2(CzCH2CH2CH2)SiOι/2)0.5(SiO4/2)0.35 wherein Me is methyl, Et is ethyl, Ph is phenyl, Cz is N-carbazolyl, and the numerical subscripts denote mole fractions.
[0050] The second hyperbranched polysiloxane can be prepared by reacting a hyperbranched polysiloxane having the formula:
(RlHSiθ2/2)a(R1HX1SiO1/2)b(R1Siθ3/2)c(SiO4/2)d(X2nX3pSiO(4.n.p)/2)e (I)
with an endblocking agent selected from at least one silane having the formula R32R4SiX4, at least one disiloxane having the formula (R32R SiO)2, at least one disilazane having the formula (R32 ^Si)2NH, and a mixture comprising at least two of the preceding agents, in the presence of water and an effective amount of a water-miscible organic solvent, wherein R is C\ to C\ o hydrocarbyl or -H; R3 is C to CJQ hydrocarbyl; R4 is R3, H, or -(CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10; R^ is R3 or -H; χl and X2 are independently -CI, -Br, -I, -O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is C\ to Cg hydrocarbyl or halogen-substituted hydrocarbyl and Y is a divalent organic group; X3 is X2 or -OH; X4 is a hydrolysable group or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; n+p is 1, 2, or 3; and the mole ratio of the endblocking agent to the silicon-bonded groups X2 in the hyperbranched polysiloxane (I) is from 1 : 1 to 2: 1 ; provided either X1, or X2 and X3 are -CI, -Br, or -I, and when X2 is -CI, -Br, -I, or -O(O=)CR2, X3 is not -OH.
[0051] Hyperbranched polysiloxane (I) is the first hyperbranched polysiloxane, described and exemplified above.
[0052] The endblocking agent is selected from at least one silane having the formula
R32R SiX4, at least one disiloxane having the formula (R32R4SiO)2, at least one disilazane having the formula (R^R^Si^NH, and a mixture comprising at least two of the preceding agents, wherein R3, R4, and R are as described and exemplified above for the second hyperbranched polysiloxane, and X4 is a hydrolysable group or -OH. As used herein, the term "hydrolysable group" means the silicon-bonded group X4 can react with water to form a silicon-bonded -OH (silanol) group. Examples of hydrolysable groups represented by X4 include, but are not limited to, -CI, -Br, -OR2, -O-Y-O-R2, CH3C(=O)O-, Et(Me)C=N-O-,
CH3C(=O)N(CH3)-, and -ONH2, wherein R2 is C\ to Cg hydrocarbyl or halogen-substituted hydrocarbyl and Y is a divalent organic group, as described and exemplified above. [0053] Examples of silanes having the formula R32R4SiX4, wherein R3 and R4 are as described and exemplified above for the second hyperbranched polysiloxane, and X4 is a hydrolysable group or -OH, include, but are not limited to, chlorodimethylsilane, chlorotrimethylsilane, chloromethylphenylsilane, triethylsilanol, triphenylsilanol, allylchlorosilane, and acetoxydimethylsilane. [0054] The silane can be a single silane or a mixture comprising two or more different silanes, each having the formula R32R4SiX4, wherein R3, R4, and X4 are as defined and exemplified above.
[0055] Methods of preparing silanes are well known in the art; many of these silanes are commercially available. The silane having the formula R32R4SiX4, wherein R4 is -(CH2)q- Cz, can be prepared by reacting a silane having the formula R32HSiX4 with an alkenyl carbazole having the formula Cz-(CH2)q_2-CH=CH2 in the presence of a hydrosilylation catalyst, wherein R3, Cz, and q are as defined and exemplified above for the second hyperbranched polysiloxane and X4 is a hydrolysable group or -OH.
[0056] Examples of disiloxanes having the formula (R 2R4SiO)2, wherein R3 and R4 are as described and exemplified above for the second hyperbranched polysiloxane, include, but are not limited to, 1,1,3,3-tetramethyldisiloxane, 1,1,3,3-tetraethyldisiloxane, 1,3-dimethyl- 1,3-diphenyldisiloxane, hexamethyldisiloxane, and pentamethyldisiloxane. [0057] The disiloxane can be a single disiloxane or a mixture comprising two or more different disiloxanes, each having the formula (R32 4SiO)2, wherein R3 and R4 are as described and exemplified above for the second hyperbranched polysiloxane. [0058] Methods of preparing disiloxanes are well known in the art; many of these disiloxanes are commercially available. The disiloxane having the formula (R 2R4SiO)2, wherein R4 is -(CH2)q-Cz, can be prepared by reacting a disiloxane having the formula
(R32HSiO)2 with an alkenyl carbazole having the formula Cz-(CH2)q_2-CH=CH2 in the presence of a hydrosilylation catalyst, wherein R3, Cz, an q are as defined and exemplified above for the second hyperbranched polysiloxane.
[0059] Examples of disilazanes having the formula (R32R->Si)2NH, wherein R3 and R^ are as defined and exemplified above for the second hyperbranched polysiloxane include, but are not limited to, hexamethyldisilazane, tetramethyldisilazane, and pentamethyldisilazane. [0060] The disilazane can be a single disilazane or a mixture comprising two or more different disilazanes, each having the formula (R-^R^Sf NH wherein R3 and R^ are as defined and exemplified above for the second hyperbranched polysiloxane. Methods of preparing disilazanes are well known in the art; many of these disilazanes are commercially available.
[0061] The endblocking agent can be a single endblocking agent selected from the silane, disiloxane, and disilazane, described above, or a mixture comprising at least two of the agents.
[0062] As used herein, the term "water-miscible organic solvent" means the organic solvent is substantially miscible with water or completely miscible (i.e., miscible in all proportions) with water. For example, the solubility of the water-miscible organic solvent in water is typically at least 90 g/100 g of water at 25 °C. Examples of water-miscible organic solvents include, but are not limited to, monohydric alcohols such as methanol, ethanol, 1-propanol, and 2-propanol; dihydric alcohols such as ethylene glycol and propylene glycol; polyhydric alcohols such as glycerol and pentaerythritiol; and dipolar aproptic solvents such as N,N- dimethylformamide, tetrahydrofuran, dimethyl sulfoxide, and acetonitrile. The water- miscible organic solvent can be a single water-miscible organic solvent or a mixture comprising two or more different water-miscible organic solvents, each as defined above.
[0063] When the endblocking agent is a silane having the formula R32R4SiX4, wherein R3 and R4 are as defined above and X4 is -OH or a hydrolysable group that does not react with water to form an acid, the reaction mixture can further comprise a condensation catalyst. The term "hydrolysable group that does not react with water to form an acid" means the hydrolysable group does not react with water in the absence of a catalyst at any temperature from room temperature to 100 °C within several minutes, for example thirty minutes, to form an acid. Examples of hydrolysable groups that do not react with water to form an acid include, but are not limited to, -OR2, -O-Y-O-R2, Et(Me)C=N-O-, CH3C(=O)N(CH3), and -
ONH2, wherein R2 and Y are as defined and exemplified above.
[0064] The condensation catalyst can be any condensation catalyst typically used to promote condensation of silicon-bonded hydroxy (silanol) groups to form Si-O-Si linkages. Examples of condensation catalysts include, but are not limited to, tin(II) and tin(IV) compounds such as tin dilaurate, tin dioctoate, and tetrabutyl tin; and titanium compounds such as titanium tetrabutoxide. When present, the concentration of the condensation catalyst is typically from 0.1 to 10% (w/w), alternatively from 0.5 to 5% (w/w), alternatively from 1 to 3% (w/w), based on the weight of the hyperbranched polysiloxane (I). [0065] The reaction can be carried out in any standard reactor suitable for reacting halosilanes with disiloxanes or disilazanes in the presence of water. Suitable reactors include glass and Teflon-lined glass reactors. Preferably, the reactor is equipped with a means of agitation, such as stirring. The reaction can be carried out at atmospheric, subatmospheric, or supraatmospheric pressure. Also, preferably, the reaction is carried out in an inert atmosphere, such as nitrogen or argon.
[0066] Typically, water is added slowly to a mixture comprising the hyperbranched polysiloxane, the endblocking agent, and the water-miscible organic solvent. [0067] The reaction is typically carried out at a temperature of from 0 to 100 °C, alternatively from room temperature (~23 °C) to 80 °C. When the temperature is less than 0 °C, the rate of reaction is typically very slow. When the temperature is greater than 100 °C, the Si-H groups in the hyperbranched polysiloxane may be converted into silanol groups (Si- OH).
[0068] The reaction is typically carried out for a period of time sufficient to complete the condensation reaction between the hyperbranched polysiloxane (I) and the endblocking agent. The term "complete the condensation reaction" means the hyperbranched polysiloxane product does not contain silicon-bonded groups X1, X2, or X3, as determined by NMR. The reaction time depends on several factors, such as the structures of the hyperbranched polysiloxane (I) and the endblocking agent, and the temperature. The time of reaction is typically from 2 to 48 h at a temperature of from 0 to 100 °C. The optimum reaction time can be readily determined by routine experimentation using the methods set forth in the Examples section below.
[0069] The mole ratio of the endblocking agent to the silicon-bonded groups X2 in the hyperbranched polysiloxane (I) is typically from 1:1 to 2:1, alternatively from 1.1:1 to 1.5:1.
[0070] The concentration of water in the reaction mixture depends on the nature of X1, X2, and X3, and the structure of the endblocking agent. The concentration of water is typically from 0.5 to 10% (w/w), alternatively from 1 to 3% (w/w), based on the total weight of the reaction mixture. When the endblocking agent has the formula R 2R4SiX4, wherein X4 is -
OH, only a trace amount, for example, 100 ppm, of water is required in the reaction mixture. [0071] The water-miscible organic solvent is present in an effective amount in the reaction mixture. As used herein, the term "effective amount" means the concentration of the water- miscible solvent is such that the hyperbranched polysiloxane (I) and the endblocking agent are soluble in the reaction mixture containing the water-miscible organic solvent. The concentration of the water-miscible organic solvent is typically from about 50 to 99% (w/w), alternatively from 50 to 90% (w/w), alternatively from 60 to 80% (w/w), based on the total weight of the reaction mixture. The effective amount of the water-miscible organic solvent can be determined by routine experimentation using the methods in the Examples section below. [0072] The second hyperbranched polysiloxane can be recovered from the reaction mixture by filtering the mixture to remove any Lewis acid catalyst introduced into the reaction mixture from the hyperbranched polysiloxane (I), and then evaporating the volatile solvent and or by-products. Conventional methods of evaporation can be used. For example, the mixture can be heated under reduced pressure, or heated and purged with an inert gas, such as nitrogen.
[0073] The second hyperbranched polysiloxane, wherein the subscript y has a value of 0, can also be prepared by reacting a hyperbranched polysiloxane having the formula:
(RlHSiθ2/2)a(R1HX1SiO1/2)b(R1Siθ3/2)c(SiO4/2)d(X2nX3pSiO(4.n.p)/2)e (I)
with an endblocking agent having the formula R 2R4Siχ5 in the presence of a Lewis acid catalyst and, optionally, an organic solvent, wherein R1 is C\ to C Q hydrocarbyl or -H; R3 is Ci to Ci o hydrocarbyl; R4 is R3, H, or -(CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10; X1, X2, and X5 are independently -CI, -Br, -I, -O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is C\ to Cg hydrocarbyl or halogen-substituted hydrocarbyl and
Y is a divalent organic group; X3 is X2 or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; n+p is 1, 2, or 3; and the mole ratio of the endblocking agent to the silicon-bonded groups X2 in the hyperbranched polysiloxane (I) is from 1:1 to 2:1; provided either X1, or X2 and X3 are -CI, -Br, or -I, when X2 is -CI, -Br, -I, or -O(O=)CR2, X3 is not -OH, and either X2 or X^ is -CI, -Br, or -I. The second hyperbranched polysiloxane prepared by the preceding method may contain minor amounts of unreacted silicon-bonded χl groups.
[0074] Hyperbranched polysiloxane (I) is the first hyperbranched polysiloxane, described and exemplified above. The Lewis acid catalyst and organic solvent are as described and exemplified above in the method of preparing the first hyperbranched polysiloxane. Because, the Lewis acid catalyst used to prepare hyperbranched polysiloxane (I) is typically not removed from the preparation, it can also be used as the Lewis acid catalyst in the present method. [0075] The endblocking agent is at least one silane having the formula R 2R4Siχ5, wherein R3 and R4 are as defined and exemplified above for the second hyperbranched polysiloxane, and X5 is -CI, -Br, -I, -O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is Cx to Cg hydrocarbyl or halogen-substituted hydrocarbyl and Y is a divalent organic group.
[0076] Examples of endblocking agents having the formula R32R4Siχ5, wherein R3, R4, and χ5 are as defined and exemplified above, include, but are not limited to, chlorodimethylsilane, chlorotrimethylsilane, chloromethylphenylsilane, allylchlorosilane, acetoxydimethylsilane, isopropoxydimethylsilane, and t-butoxydimethylsilane. [0077] The endblocking agent can be a single silane or a mixture comprising two or more different silanes, each having the formula R32R4Siχ5, wherein R3, R4, and X^are as defined and exemplified above. Methods of preparing silanes having the preceding formula are well known in the art; many of these silanes are commercially available. [0078] The reaction can be carried out in any standard reactor suitable for reacting halosilanes with alkoxysilanes or acyloxysilanes. Suitable reactors include glass and Teflon- lined glass reactors. Preferably, the reactor is equipped with a means of agitation, such as stirring. The reaction can be carried out at atmospheric, subatmospheric, or supraatmospheric pressure. Also, preferably, the reaction is carried out in an inert atmosphere, such as nitrogen or argon, in the absence of moisture.
[0079] The hyperbranched polysiloxane (I), endblocking agent, Lewis acid catalyst, and organic solvent can be combined in any order. Typically, the Lewis acid catalyst is added to a mixture comprising the hyperbranched polysiloxane (I), endblocking agent, and, optionally, organic solvent.
[0080] The reaction is typically carried out at a temperature of from 0 to 100 °C, alternatively from room temperature (~23 °C) to 80 °C. When the temperature is less than 0 °C, the rate of reaction is typically very slow.
[0081] The reaction is typically carried out for a period of time sufficient to complete the condensation reaction between the hyperbranched polysiloxane (I) and the endblocking agent. The term "complete the condensation reaction" means the hyperbranched polysiloxane product does not contain silicon-bonded groups X1, X2, or X3, as determined by NMR. The reaction time depends on several factors, such as the structures of the hyperbranched polysiloxane (I) and the endblocking agent, and the temperature. The time of reaction is typically from 2 to 48 h at a temperature of from 0 to 100 °C. The optimum reaction time can be readily determined by routine experimentation using the methods set forth in the Examples section below.
[0082] The mole ratio of the endblocking agent to the silicon-bonded groups X2 in the hyperbranched polysiloxane (I) is typically from 1:1 to 2:1, alternatively from 1.1:1 to 1.5:1. [0083] The concentration of the Lewis acid catalyst is sufficient to catalyze the condensation reaction between the hyperbranched polysiloxane (I) and the endblocking agent. Typically, the concentration of the Lewis acid catalyst is from 0.1 to 3% (w/w), alternatively from 0.5 to 1% (w/w), based on the combined weight of the hyperbranched polysiloxane (I) and the endblocking agent.
[0084] The concentration of the organic solvent is typically from 0 to 50% (w/w), alternatively from 0 to 10% (w/w), based on the total weight of the reaction mixture. [0085] The second hyperbranched polysiloxane can be recovered from the reaction mixture by adding sufficient quantity of water to effect precipitation of the Lewis acid catalyst, extracting the hyperbranched polysiloxane with an organic solvent, and removing the organic solvent from the extract. The organic solvent can be removed using conventional methods of evaporation. For example, the mixture can be heated under reduced pressure or heated and purged with an inert gas, such as nitrogen. Optionally, after the addition of water, the reaction mixture can be filtered to remove the Lewis acid precipitate before extraction. Example of organic solvents include, but are not limited to, saturated aliphatic hydrocarbons such as n-pentane, hexane, and n-heptane; cycloaliphatic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as benzene, toluene, xylene and mesitylene; and halogenated aromatic hydrocarbons such as bromobenzene and chlorobenzene. [0086] The hyperbranched polysiloxanes of the present invention contain a high concentration of silicon-bonded hydrogen atoms compared to known hyperbranched or dendritic polysiloxanes. Also, the hyperbranched polysiloxanes have lower viscosities than linear polysiloxanes of the same molecular weights and tend to be more soluble in organic solvents than linear analogues. Importantly, the hyperbranched polysiloxanes are hydrolytically stable and resistant to degradation by moisture. [0087] The hyperbranched polysiloxanes of the present invention are useful in the preparation of novel hyperbranched polysiloxanes containing various functional groups, introduced by hydrosilylation reactions, in place of hydrogen. Also, the hyperbranched polysiloxanes can be used in the preparation of hydrosilylation-curable silicone compositions further comprising a crosslinking agent having carbon-carbon double bonds, and a hydrosilylation catalyst. Furthermore, the hyperbranched polysiloxanes containing reactive groups represented by X1, X2, and X3, in addition to silicon-bonded hydrogen atoms, can be used in the formulation of condensation-curable silicone compositions.
EXAMPLES [0088] The following examples are presented to better illustrate the hyperbranched polysiloxanes of the present invention, but are not to be considered as limiting the invention, which is delineated in the appended claims. Unless otherwise noted, all parts and percentages reported in the examples are by weight. The symbols used to designate the siloxane units in formulas below are defined as follows:
DH = HMeSiO2/2
DH2 = H2SiO2/2
T = MeSiO3/2
TH = HSiO /2
T i = (CH2=CH)SiO3/2
Q = SiO4/2
The following methods and materials were employed in the examples:
Infrared Spectra
[0089] Infrared spectra of hyperbranched polysiloxanes were recorded on a Perkin Elmer Instruments 1600 FT-IR spectrometer. An aliquot of a reaction mixture containing the polysiloxane was dissolved in THF or toluene to achieve a concentration of approximately 10%. A drop of the solution was applied to a NaCl window and the solvent was evaporated under a stream of dry nitrogen to form a thin film of the polysiloxane. NMR Spectra
[0090] Nuclear magnetic resonance spectra (2^Si NMR) of hyperbranched polysiloxanes were obtained using a Varian Mercury 400 MHz NMR spectrometer. The polysiloxane (0.5- l.Og) was dissolved in 2.5-3mL of chloroform-d in a 0.5 oz glass vial. The solution was transferred to a Teflon NMR tube and 3-4 mL of a solution of Cr(acac)3 in chloroform-d
(0.04 M) was added to the tube. The chemical shift values (δ) reported in the examples are in units of parts per million (ppm), measured relative to tetramethylsilane in the ^Si NMR spectra.
Determination of Molecular Weights
[0091] Number-average and weight-average molecular weights (Mn and Mw) of hyperbranched polysiloxanes were determined by gel permeation chromatography (GPC) using a PLgel (Polymer Laboratories, Inc.) 5-μm column at room temperature (~23 °C), a THF mobile phase at 1 mL/min, and a refractive index detector. Polystyrene standards were used for linear regression calibrations.
Example 1
[0092] Dichloromethylsilane (115.8 g) and 292.6 g of di-t-butoxydiacetoxysilane were combined under nitrogen in a 3 -neck glass flask equipped with a magnetic stir bar. The mixture was treated with a solution (10 mL) consisting of boron trichloride (1M) in xylene and then kept at room temperature overnight. The mixture was heated under nitrogen successively at 50 °C for 2 h, 100 °C for 1.5 h, and 140 °C for 0.5 h. A portion (3 g) of the resulting viscous fluid, 2.5 g of chlorodimethylsilane, and 10 ml of tetrahydrofuran (THF) were combined in a glass vial. Water (0.5 g) was added to the mixture and the vial was sealed with a cap and kept at room temperature overnight. Most of the THF was evaporated by directing a stream of air across the surface of the mixture to produce a viscous fluid. The
FTIR spectrum of the product showed an Si-H absorption at 2138.6 cm"l with a shoulder at
2184 cm"1, and a strong absorption at 901 cm"1. Example 2
[0093] Dichloromethylsilane (11.5 g) was added under nitrogen to a 3 -neck glass flask equipped with a magnetic stir bar. The flask was sealed with a septum and then cooled in dry ice. A solution consisting of 26.4 g of tri-tert-butoxysilanol in 20 ml of anhydrous tetrahydrofuran (THF) was slowly added to the dichloromethylsilane under vigorous stirring to dissipate heat. The mixture was treated with 0.1 g of anhydrous aluminum trichloride and then kept at room temperature overnight in the closed flask. The mixture was heated under nitrogen successively at 60 °C for 1 h and 120 °C for 2 h to produce 14.5 g of a slightly cloudy viscous fluid. The viscous fluid was dissolved in 100 ml of THF and the solution was treated with 10 ml of chlorodimethylsilane. Water (0.4 g) was added to the flask drop- wise under vigorous stirring to dissipate heat and the flask was kept at room temperature overnight, during which time a white precipitate formed. Most of the THF was removed by venting the flask, continuously purging the system with a stream of air, and heating the mixture at 60 °C. The resulting viscous fluid solidified at low temperature (below 0 °C) after the solvent was completely evaporated. The hyperbranched polysiloxane product had a number-average molecular weight and a weight-average molecular weight of 1885 and 3413, respectively. The composition of the product, as determined by Si NMR, was Ho.57DH0.53Tθ.5Q-
Example 3
[0094] Dichlorosilane (40.4 g) and 29.2 g of di-tert-butoxydiacetoxysilane were combined under nitrogen in a 3 -neck glass flask equipped with a magnetic stir bar. The mixture was treated with 0.5 g of anhydrous aluminum trichloride and then kept at room temperature overnight. The mixture was heated successively at 45 °C for 2 h and at 120 °C for 2 h to produce ~ 14.2 g of a viscous fluid. The viscous fluid was dissolved in 100 ml of tetrahydrofuran (THF) and the solution was treated with 20 ml of tetramethyldisilazane. Water (4 g) was added to the flask drop- wise under vigorous stirring to dissipate heat and the flask was kept at room temperature overnight, during which time a white precipitate formed. Most of the THF was removed by venting the flask, continuously purging the system with a stream of air, and heating the mixture at 60 °C. The resulting product had a number-average molecular weight and a weight-average molecular weight of 3719 and 9034, respectively. The composition of the product, as determined by 2^Si NMR, was MH1 6θDH20 13τH0 33Q.
Example 4
[0095] A solution (40.4 g) consisting of 25% of dichlorosilane in xylene was added under nitrogen to a 3 -neck glass flask equipped with a magnetic stir bar. The flask was sealed with a septum and cooled in dry ice. A solution consisting of 26.4 g of tri-t-butoxysilanol, 9.5 g of triethylamine, and 15 ml of anhydrous tetrahydrofuran (THF) were added drop- wise to the mixture under vigorous stirring. A white precipitate formed immediately. Toluene (50 mL) was added to flask and the precipitate was removed by filtration. The filtrate was treated with 0.1 g of anhydrous aluminum trichloride under nitrogen and the mixture was kept at room temperature overnight in a closed flask. The mixture was heated at 60 °C for 1 h and at 120 °C for 2 h under nitrogen to produce a viscous fluid.

Claims

That which is claimed is:
1. A hyperbranched polysiloxane having the formula:
(RlHSiθ2/2)a(R1HχlSiOι/2)b(R1Siθ3/2)c(SiO4/2)d(X2nX3pSiO(4.n-p)/2)e
wherein R is C\ to CJQ hydrocarbyl or -H; X1 and X2 are independently -CI, -Br, -I, - O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is Ci to Cg hydrocarbyl or halogen- substituted hydrocarbyl and Y is a divalent organic group; X3 is X2 or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; and n+p is 1, 2, or 3; provided either X1, or X2 and X3 are -CI, -Br, or -I, and when X2 is -CI, -Br, -I, or -O(O=)CR2 X3 is not -OH.
2. The hyperbranched polysiloxane according to claim 1, wherein the subscript a has a value of from 20 to 50 mol%; the subscript b has a value of from 0.1 to 10 mol%; the subscript c has a value of from 0.1 to 30 mol%; the subscript d has a value of from 10 to 40 mol%; and the subscript e has a value of from 30 to 50 mol%.
3. A method of preparing a hyperbranched polysiloxane, comprising reacting a difunctional silane having the formula R^HSiX^ with at least one tetrafunctional silane having the formula X3SiX23 in the presence of a Lewis acid catalyst and, optionally, an organic solvent, wherein R1 is Ci to CJQ hydrocarbyl or-H; X^and X2 are independently -
CI, -Br, -I, -O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is C\ to Cg hydrocarbyl or halogen-substituted hydrocarbyl and Y is a divalent organic group; X3 is X2 or -OH; and the mole ratio of the difunctional silane to the tetrafunctional silane is from 0.8:1 to 1.2:1; provided either X1, or X2 and X3 are -CI, -Br-, or -I, and when X2 is -CI, -Br, -I, or -
O(O=)CR2, X3 is not -OH.
4. The method according to claim 3, wherein the mole ratio of the difunctional silane to the tetrafunctional silane is from 0.9:1 to 1.1:1.
5. A hyperbranched polysiloxane having the formula:
(RlHSiθ2/2)v(R1Siθ3/2)w(R32R4SiOι/2)x(R32R5SiOι/2)y(SiO4/2)z
wherein R! is C\ to C\ Q hydrocarbyl or -H; R3 is Ci to Ci o hydrocarbyl; R4 is R3, -H, or -
(CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10; Rp is R3 or -H; v is from 0 to 40 mol%; w is from 0 to 40 mol%; x is from 0 to 60 mol%; y is from. 0 to 60 mol%; z is from 10 to 60 mol%; and the sum x+y is from 10 to 60 mol%.
6. The hyperbranched polysiloxane according to claim 5, wherein the subscript v has a value of from 5 to 25 mol%; the subscript w has a value of from 0 to 10 mol%; the subscript x has a value of from 0 to 50 mol%; the subscript y has a value of from 0 to 50 mol%, the subscript z has a value of from 20 to 50 mol%; and the sum x+y has a value of from 20 to 50 mol%.
7. A method of preparing a hyperbranched polysiloxane, comprising reacting a hyperbranched polysiloxane having the formula: (RlHSiθ2/2)a(R1HX1SiOι/2)b(R1Siθ3/2)c(SiO4/2)d(X2nX3pSiO(4.n.p /2)e with an endblocking agent selected from at least one silane having the formula R32R4SiX4, at least one disiloxane having the formula (R32R4SiO)2, at least one disilazane having the formula (R^R^Sf^NH, and a mixture comprising at least two of the preceding agents, in the presence of water and an effective amount of a water-miscible organic solvent, wherein R! is Ci to Cio hydrocarbyl or -H; R3 is Ci to Ci Q hydrocarbyl; R4 is R3, H, or -(CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10; R^ is R3 or -H; 1 and X2 are independently -CI, -Br, -I, -O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is Ci to Cg hydrocarbyl or halogen-substituted hydrocarbyl and Y is a divalent organic group; X3 is X2 or -OH; X4 is a hydrolysable group or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; n+p is 1, 2, or 3; and the mole ratio of the endblocking agent to the silicon-bonded groups X2 in the hyperbranched polysiloxane is from 1:1 to 2:1; provided either χl, or X2 and X3 are -CI, -Br, or -I, and when X2 is -CI, -Br, -I, or -O(O=)CR2, X3 is not -OH.
8. The method according to claim 7, wherein the endblocking agent is a silane having the formula R32R4SiX4, wherein R3 and R4 are as defined above and X4 is -OH or a hydrolysable group that does not react with water to form an acid, and further comprising a condensation catalyst.
9. The method according to claim 7, wherein the mole ratio of the endblocking agent to the silicon-bonded groups X2 in the hyperbranched polysiloxane is from 1.1:1 to 1.5:1.
10. A method of preparing a hyperbranched polysiloxane, comprising reacting a hyperbranched polysiloxane having the formula: (RlHSiθ2/2)a(R1HX1SiO1/2)b(R1Siθ3/2)c(SiO4/2)d(X2 nX3pSiO(4.n.p)/2)e
with an endblocking agent having the formula R 2R4Siχ5 jn the presence of a Lewis acid catalyst and, optionally, an organic solvent, wherein R1 is Cj to Ci Q hydrocarbyl or -H; R3 is C\ to C o hydrocarbyl; R4 is R3, H, or -(CH2)q-Cz, wherein Cz is N-carbazolyl and q is an integer from 2 to 10; X1, X2, and X5 are independently -CI, -Br, -I, -O(O=)CR2, -OR2, or -O-Y-O-R2, wherein R2 is C\ to Cg hydrocarbyl or halogen-substituted hydrocarbyl and
Y is a divalent organic group; X3 is X2 or -OH; a is from 5 to 50 mol%; b is from 0.1 to 25 mol%; c is from 0.01 to 50 mol%; d is from 5 to 50 mol%; e is from 5 to 70 mol%; n is 0, 1, 2, or 3; p is 0 or 1; n+p is 1, 2, or 3; and the mole ratio of the endblocking agent to the silicon-bonded groups X2 in the hyperbranched polysiloxane (I) is from 1 : 1 to 2: 1 ; provided either X1, or X2 and X3 are -CI, -Br, or -I, when X2 is -CI, -Br, -I, or -O(O=)CR2, X3 is not -OH, and either X2 or X5 is -CI, -Br, or -I.
1. The method according to claim 10, wherein the mole ratio of the endblocking agente silicon-bonded groups X2 in the hyperbranched polysiloxane is from 1.1:1 to 1.5:1.
PCT/US2004/020943 2003-09-11 2004-06-29 Hyperbranched polysiloxanes Ceased WO2005035630A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US50207903P 2003-09-11 2003-09-11
US60/502,079 2003-09-11

Publications (1)

Publication Number Publication Date
WO2005035630A1 true WO2005035630A1 (en) 2005-04-21

Family

ID=34434840

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US2004/020943 Ceased WO2005035630A1 (en) 2003-09-11 2004-06-29 Hyperbranched polysiloxanes

Country Status (1)

Country Link
WO (1) WO2005035630A1 (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008000353A1 (en) 2008-02-20 2009-08-27 Wacker Chemie Ag Hardenable polymer blends
DE102008041097A1 (en) 2008-08-07 2010-02-11 Wacker Chemie Ag Process for the preparation of silicone-based foams
CN108659224A (en) * 2018-05-29 2018-10-16 西北工业大学 A kind of hyperbranched polyorganosiloxane fluorescent material and preparation method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5446087A (en) * 1992-12-04 1995-08-29 Rhone-Poulenc Chimie Curable release compositions comprising novel silicone adhesion modifier
EP0940421A2 (en) * 1998-03-06 1999-09-08 Dow Corning Corporation Hyperbranched polymers
US6140525A (en) * 1997-11-24 2000-10-31 Russian Academy Of Sciences Hyperbranched polymers and methods for the preparation thereof
US6307081B1 (en) * 1997-11-24 2001-10-23 Dow Corning Silicone Company, Ltd. Hyperbranched polymers and methods for the preparation, cure, and stabilization thereof

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5446087A (en) * 1992-12-04 1995-08-29 Rhone-Poulenc Chimie Curable release compositions comprising novel silicone adhesion modifier
US6140525A (en) * 1997-11-24 2000-10-31 Russian Academy Of Sciences Hyperbranched polymers and methods for the preparation thereof
US6307081B1 (en) * 1997-11-24 2001-10-23 Dow Corning Silicone Company, Ltd. Hyperbranched polymers and methods for the preparation, cure, and stabilization thereof
EP0940421A2 (en) * 1998-03-06 1999-09-08 Dow Corning Corporation Hyperbranched polymers

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
MATHIAS L J ET AL: "HYPERBRANCHED POLY(SILOXYSILANES)", JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, AMERICAN CHEMICAL SOCIETY, WASHINGTON, DC, US, vol. 113, 1991, pages 4043 - 4044, XP002048742, ISSN: 0002-7863 *
RUBINSZTAJN S: "SYNTHESIS AND CHARACTERIZATION OF NEW POLY(SILOXYSILANES)", JOURNAL OF INORGANIC AND ORGANOMETALLIC POLYMERS, NEW YORK, NY, US, vol. 4, no. 1, March 1994 (1994-03-01), pages 61 - 77, XP002047244 *

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE102008000353A1 (en) 2008-02-20 2009-08-27 Wacker Chemie Ag Hardenable polymer blends
WO2009103604A1 (en) * 2008-02-20 2009-08-27 Wacker Chemie Ag Curable polymer mixtures
DE102008041097A1 (en) 2008-08-07 2010-02-11 Wacker Chemie Ag Process for the preparation of silicone-based foams
US8455561B2 (en) 2008-08-07 2013-06-04 Wacker Chemie Ag Method for the production of foams on silicone basis
CN108659224A (en) * 2018-05-29 2018-10-16 西北工业大学 A kind of hyperbranched polyorganosiloxane fluorescent material and preparation method
CN108659224B (en) * 2018-05-29 2021-01-05 西北工业大学 A kind of hyperbranched polysiloxane fluorescent material and preparation method thereof

Similar Documents

Publication Publication Date Title
KR100359392B1 (en) Thermosetting silicone resins
CN101842415B (en) Method for producing branched SiH functional polysiloxanes and the use thereof for producting SiC- and SiOC-linked, branched organomodified polysiloxanes
KR101506205B1 (en) Resin-linear organosiloxane block copolymers
KR101477609B1 (en) High refractive index compositions containing resin-linear organosiloxane block copolymers
US20110021736A1 (en) Polyborosiloxane and Method of Preparing Same
US20190106441A1 (en) Mixtures Of Cyclic Branched Siloxanes Of The D/T Type And Conversion Products Thereof
US9006358B2 (en) Compositions of resin-linear organosiloxane block copolymers
JP2002212294A (en) Multibranched polycarbosilane, polycarbosiloxane, polycarbosilazene and copolymer thereof
EP0972788B1 (en) Hyperbranched polymers containing silicon atoms
KR20160057428A (en) Compositions of resin-linear organosiloxane block copolymers
Anisimov et al. Carborane–siloxanes: synthesis and properties. New possibilities for structure control
WO1999043738A1 (en) Silyl and siloxyl substituted carborane compositions with unsaturated organic end groups
WO1999043737A1 (en) Silyl and siloxyl substituted carboranes with unsaturated organic end groups
Chruściel Hydrosilyl-Functional Polysiloxanes: Synthesis, Reactions and Applications
WO2005035630A1 (en) Hyperbranched polysiloxanes
Allcock et al. Hybrid phosphazene-organosilicon polymers: II. High-polymer and materials synthesis and properties
WO2005035629A1 (en) Hyperbranched polysiloxanes
Kawahara et al. Dendritic, Nanosized Building Block for Siloxane‐Based Materials: A Spherosilicate Dendrimer
KR101037417B1 (en) Process for preparing high molecular weight organopolysiloxane
EP0768331B1 (en) Sheet and tube siloxane polymers
Hengge et al. Recent advances in the chemistry of cyclopolysilanes
Flipsen et al. Densely crosslinked polycarbosiloxanes. I. Synthesis
Leśniak et al. One-step synthesis of thermoplastic phenylsilsesquioxane polymer and its copolymers with diphenylsiloxanes
RU2685545C1 (en) Oligosiloxanes with hydrophilic and hydrophobic branches as a modifier for siloxane rubber and a method for production thereof
Mukbaniani et al. Formation of new thermoreactive polysiloxanes

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

121 Ep: the epo has been informed by wipo that ep was designated in this application
122 Ep: pct application non-entry in european phase