Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K5/00—Use of organic ingredients
  • C08K5/54—Silicon-containing compounds
  • C08K5/541—Silicon-containing compounds containing oxygen
  • C08K5/5415—Silicon-containing compounds containing oxygen containing at least one Si—O bond
  • C08K5/5419—Silicon-containing compounds containing oxygen containing at least one Si—O bond containing at least one Si—C bond
• • 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
  • C07F7/0836—Compounds with one or more Si-OH or Si-O-metal linkage
• • 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
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D183/00—Coating compositions based on 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; Coating compositions based on derivatives of such polymers
  • C09D183/04—Polysiloxanes
• • 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
  • C08G77/42—Block-or graft-polymers containing polysiloxane sequences
  • C08G77/44—Block-or graft-polymers containing polysiloxane sequences containing only polysiloxane sequences

Definitions

• This invention relates to curable silicone resin compositions and to reactive silicon compounds useful in such curable compositions.
• GB1101589 describes a process for the production of an organosilicon resin by heating in the presence of a solvent a compound of the formula Rl (R2 ) 2 Si-R-Si (R2 ) 2 R1 where R is phenylene, diphenylene or diphenylene oxide, Rl is a monovalent hydrocarbon or substituted hydrocarbon group and R2 is alkoxy or hydroxy, with a compound of the formula R4(R3) 2 Si- R-Si(R3) 2 R4 where each R3 is a monovalent hydrocarbon or substituted hydrocarbon group and R4 is acyloxy, alkoxy or hydroxy.
• a curable silicone resin composition according to the present invention comprises (A) an uncured silicone resin having units of the formula (R*) a (R )bSiO( 4 - a -t > ) /2 / where each R* is a functional group capable of reacting with Si-OH and/or Si-alkoxy groups and each R is a nonfunctional monovalent hydrocarbon group, a+b is from 1.0 to 3.0 and each molecule of uncured silicone resin contains an average of at least two groups R* , and (B) a silanol or hydrolysable compound of the formula
• each R' represents a hydroxyl group or a hydrolysable group
• each R" represents hydrogen, a monovalent hydrocarbon which optionally is substituted, or a group within the above definition of R'
• Ar is a substantially nonflexible linkage including at least one para-arylene moiety, so that the groups (R') 2 R"Si- are spatially separated.
• the compound (B) reacts with the functional groups R* of the silicone resin to crosslink the resin (A) to a structure having improved mechanical properties and generally less brittle than that obtained by curing the resin (A) alone.
• the groups (R') 2 R"Si- are spatially separated by the nonflexible linkage Ar so that intramolecular self-reaction of the groups (R') 2 R"Si- is avoided.
• Figure 1 is a graph showing the dynamic mechanical analysis results of Example 21.
• Figure 2 is a graph showing the dynamic mechanical analysis results of Example 22.
• the nonflexible linkage Ar can be a simple p- phenylene moiety or can contain two or more phenylene groups linked in an array in such a way that the array is held in a substantially linear conformation, that is the linkage between the phenylene groups does not contain any atoms about which the parts of the molecule can freely rotate, such as a carbon atom positioned between two C-C single bonds .
• the p-phenylene groups can be part of a f sed ring system such as a 1, 4-naphthylene or 1, 10-anthracene linkage, and the term "para-arylene moiety" includes other fused ring aromatic linkages in which the (R') 2 R"Si- groups are maintained spatially separated such as a 1,5- or 2,6- naphthylene linkage or even a metallocene, e.g. ferrocene linkage in which the (R') 2 R"Si- groups are bonded to different cyclopentadiene rings.
• the compounds (B) in which the group R" is a hydroxy1 group and Ar contains two or more phenylene groups per molecule are new compounds.
• the invention thus includes an organosilicon compound of the formula (HO) 3 Si-Ar ' -Si (OH) 3 wherein Ar' is a linkage containing two or more phenylene moieties held in a substantially linear conformation so that the (R') 3 Si- groups are spatially separated.
• R' R' wherein R' and R" are defined as in Claim 1, each Ap is a para-arylene moiety, and X is a substantially inflexible linkage having at least two carbon atoms so that the groups (R') 2 R"Si- are spatially separated.
• the structure of the linkage X is such that in combination with the adjacent phenylene groups there is provided a substantially linear rigid-rod array. It is preferred that there are from 2 to 4 phenylene groups, more preferably only 2 phenylene groups, per molecule.
• the phenylene groups are generally positioned trans- to one another; although this arrangement is not strictly linear, it holds the para- (hydroxysilyl) subtituents on the phenylene groups apart from each other and is "substantially linear" within the terms of this invention .
• the para-phenylene groups Ph or any phenylene group within linkage Ar can be substituted by one or more alkyl, for example methyl, ethyl, butyl, hexyl or dodecyl , aryl, aralkyl or alkenyl group, although the phenylene groups are preferably unsubstituted.
• organobis (silane triol)s examples include 4,4' -bis ( trihydroxysilyl) biphenyl, 4,4' -bis (trihydroxysilyl) stilbene, bis (4-trihydroxysilylphenyl) acetylene and 1, 4-bis ( 4-trihydroxysilylphenyl ) butadiyne .
• the organobis (silane triol)s of the invention can be prepared by, for example, the hydrolysis of corresponding organobis (trialkoxysilyl) and organobis (trichlorosilyl) compounds.
• organobis (trialkoxysilyl) precursor can for example be hydrolysed by the methods described by Hyde as disclosed in J.Am.Chem. Soc . 1953, 75, at page 2166 or Tyler as disclosed in J.Am.Chem. Soc . 1955, 77, at page 770.
• organobis (trialkoxysilyl) compounds which can be used as compound (B) include 4,4' -bis (trimethoxysilyl) biphenyl, 4,4' -bis (trimethoxysilyl) stilbene, bis (4-trimethoxysilylphenyl) acetylene and
• Bis (trimethoxysilylphenyl) -substituted acetylenic compounds can be prepared from the condensation reaction of para-bromo (trimethoxysilyl) benzene or para-iodo (trimethoxysilyl) benzene with para- ( trimethoxysilyl ) phenylacetylene .
• Bis (trimethoxysilyl) substituted diphenylbutadiynes can be prepared by the homo coupling reaction of para- (trimethoxysilyl) phenylacetylene .
• Hydrolysis can take place under mild conditions, even by the use of water alone, although it is preferred that a catalyst such as an organic acid, particularly acetic acid, is present in order to facilitate the hydrolysis reaction. It is preferred that from 0.1 to 5% by weight of catalyst based on the weight of water present is used in the reaction mixture, more preferably from 0.25 to 2%.
• the relative proportions of water and organobis (trialkoxysilyl) precursor may vary between wide limits. Generally at least 6 moles water is present per mole of organobis (trialkoxysilane) and sufficient water may be used for the bis (trihydroxysilyl ) arene product to dissolve in the aqueous phase.
• the hydrolysis of the organobis is preferably carried out in the presence of solvent, most preferably a dipolar aprotic organic solvent such as diethyl ether or dichloromethane .
• solvent most preferably a dipolar aprotic organic solvent such as diethyl ether or dichloromethane .
• the reaction temperature is preferably in the range from 0°C to 40°C, for example ambient temperatures.
• the water and catalyst may be incorporated separately into the reaction mixture or can be pre-mixed prior to addition to the organobis (trialkoxysilyl) precursor.
• the reaction period for the hydrolysis to reach completion i.e.
• the hydrolysis of all the alkoxy groups present on the organobis (trialkoxysilyl) precursor is generally from about 30 minutes up to 1 month and the preferred reaction period is from about 1 hour to about 4 days, most preferably from 4 to 24 hours.
• the organobis (silane triol) may be recovered from the reaction mixture by conventional means, for example, by filtration or evaporation.
• organobis ( trialkoxysilane) in ether is added drop-wise quickly to a 0.5 % acetic acid/water solution at 20°C. The mixture is then stirred thoroughly until the resulting organobis ( silane triol) precipitates out in the aqueous phase. After filtration and drying overnight at 25°C the organobis (silane triol) is recovered.
• An alternative method of making the organobis (silane triol) is from a organobis (trichlorosilyl) precursor. This method includes the hydrolysis reaction of an organobis (trichlorosilyl) compound with a water/aniline mixture to form the organobis (silane triol) .
• the compounds (B) according to this invention are effective in crosslinking the silicone resin (A) and have high stability against intramolecular self-condensation.
• the invention thus includes a process for forming a cured resin composition comprising mixing (A) and (B) and curing the resulting composition under conditions such that (A) and (B) are copolymerised.
• (A) is an uncured silicone resin having units of the formula (R*) a (R ) b SiO (4 _ a -b) /2 , where each R* is a functional group capable of reacting with Si-OH and/or Si- alkoxy groups and each R is a nonfunctional monovalent hydrocarbon group and a+b is from 1.0 to 3.0.
• Each molecule of uncured silicone resin contains an average of at least two groups R* .
• the groups R* can be -OH groups, alkoxy groups or H atoms bonded to Si.
• R is selected from alkyl and aryl groups.
• Suitable alkyl groups include methyl, ethyl, isopropyl, n-butyl and isobutyl. Suitable aryl groups are exemplified by phenyl.
• Organosilicone resins particularly those prepared by acid hydrolysis and condensation, generally include a considerable concentration of residual hydroxyl groups which can react with the hydroxysilyl or alkoxysilyl groups of the compound (B) through a condensation cure system.
• the amount of (A) in the curable system is generally 5 to 96%, preferably 50 to 95%, by weight. Most preferably, the weight ratio of (A) to (B) is 5:1 to 20:1.
• the curable silicone resin composition of the invention preferably contains a catalyst so that condensation curing can be carried out at reduced, e.g. ambient temperature.
• the catalyst can be a metal ester or alkoxide of a Group IVB metal such as zirconium, hafnium or titanium, for example titanium tetrabutoxide, a metal carboxylate such as zinc octoate, choline octoate, a strong acid such as sulphuric or phosphoric acid or a base such as KOH, CsOH, a metal silanolate, calcined lime or an amine or quaternary base, for example tetramethyl ammonium hydroxide.
• the catalyst can generally be used at up to 2% by weight based on reagents, preferably 0.02 to 0.4%.
• the curable composition may additionally contain a silicone rubber, for example a rubber as described in
• the rubber generally has terminal functional groups capable of reacting with the hydroxyl groups of silicone resin (A) .
• the silicone rubber if used, can be present at up to 30% by weight, for example 5 to 20%.
• the curable composition can optionally contain a solvent at up to 90%, preferably up to 60% of the composition.
• a substrate having a cure silicone resin coated thereon can be prepared by mixing (A) and (B) in a solvent, coating the resulting solution on the substrate, and drying the coating and subjecting it to curing conditions.
• a moulded cured silicone resin can be produced by mixing (A) and (B) in a solvent, casting the resulting solution in a mould, removing the solvent and curing the composition in the mould.
• the solvent is generally a polar organic solvent, for example an amide such as formamide, dimethylformamide or dimethylacetamide, a halogenated hydrocarbon such as dichloromethane or 1,1,1- trichloroethane, an alcohol such as methanol, ethanol, isopropanol or t-butanol, an aromatic hydrocarbon such as toluene or xylene, a glycol ether such as 2-methoxypropanol, 2-butoxypropanol, butoxyethanol or dipropylene glycol methyl ether, or a sulphoxide such as dimethyl sulphoxide.
• the more polar solvents such as alcohols, formamide or dimethyl sulphoxide may be required to dissolve the organobis (silanetriol) s .
• the curable composition can be coated on a substrate, for example as a solution, and cured to form a thin film on the substrate, or can be cured in a mould to form a shaped silicone resin article.
• novel compounds of the formula (R') 3 Si-Ar' ⁇ Si(R') 3 can also be cured alone to produce strong solid resins by condensation of the R' groups. If curing is carried out in a solvent such as formamide, a gel is produced which can be powdered and dried to recover the solid resin, which contains extended chains containing arylene linkages and silicate crosslinks.
• the compounds (B) particularly the bis (trihydroxysilyl) arene compounds and the bis (dihydroxysilyl) arene compounds, have X-ray patterns showing that they are ordered in the solid state.
• the white biphasic mixture was well agitated for a period of twenty-four hours at a temperature of 20°C. During this period, a colourless solid precipitated out in the aqueous phase.
• the reaction mixture was filtered and the recovered precipitate was washed three times each with ethanol, acetone and ether and then dried overnight at a temperature of 20°C to give a white crystalline solid.
• Example 1 The procedure of Example 1 was repeated employing 4 , 4 ' -bis (trimethoxysilyl) stilbene) in place of bis (trimethoxysilyl) biphenyl (2g, 4.75 mmol) and using a 1% acetic acid solution (9 ml) to give a ratio of 2.94 equivalents of stilbene to 1 equivalent of acetic acid.
• the reaction mixture was stirred for a period of 10 days and a yellow coloured powder was recovered at 70% yield.
• Example 19 1, 4-bis (dimethoxymethylsilyl) benzene prepared in Example 13; solvent tetrahydrofuran (THF) [0077]
• Example 22 - 1 4-bis (trihydroxysilyl) benzene ; solvent DMSO
• DMA dynamic mechanical analysis
• the three point bending test was performed on an Instron 8562 (Trade Mark) test machine per ASTM standard D 790.
• the plane strain fracture toughness, K ⁇ c was obtained per ASTM D 5045, and the critical strain energy release rate, G ⁇ C / (fracture energy) was calculated from K ⁇ c based on Linear Elastic Fracture Mechanics assumptions.
• each compound (B) into the resin structure slightly lowers the resin's Young's modulus, but increases the fracture toughness (K lc ) and the critical energy release rate G ⁇ c .
• the fracture toughness K ⁇ c measures the difficulty of initiating a crack in the material, while the G ⁇ c measures how much energy per unit area it needs to propagate a crack in the material once the crack is initiated.
• the modified resin of Example 19 is slightly tougher than the unmodified resin, and the modified resin of Example 20 is substantially tougher than the unmodified resin.
• Example 21 the storage modulus (1A) and loss factor(tan ⁇ , (2A) ) of the modified resin are plotted in Figure 1, together with the storage modulus (IC) and loss factor (2C) of the unmodified resin.
• the high temperature transition peak of the tan ⁇ curve was much enhanced by the incorporation of the 4 , 4 ' -bis ( trihydroxysilyl ) diphenylbut- 1, 3-diyne.
• the addition of this modifier significantly enhances the mechanical damping capability of the resin in the temperature range 150-350oC. This damping capability is important for applications where mechanical vibration needs to be mitigated.
• Example 22 the storage modulus (IB) and loss factor (2B) of the modified resin are plotted in Figure 2, together with the storage modulus (IC) and loss factor (2C) of the unmodified resin.
• the storage modulus is much higher, approximately twice that of the unmodified resin throughout the whole temperature range, even though the modulus dependence on temperature was quite similar and no obvious shift of glass transition temperature was seen. Both had a glass transition temperature at about 100 °C .

Landscapes

• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Silicon Polymers (AREA)
• Macromonomer-Based Addition Polymer (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8173660

Family Applications (1)

Country Status (7)

Cited By (1)

Families Citing this family (3)

Citations (1)

Family Cites Families (10)

• 2001
  • 2001-04-24 WO PCT/EP2001/004606 patent/WO2001083608A1/en not_active Ceased
  • 2001-04-24 US US10/258,722 patent/US6780471B2/en not_active Expired - Fee Related
  • 2001-04-24 EP EP01940358A patent/EP1276807B1/en not_active Expired - Lifetime
  • 2001-04-24 AU AU2001273963A patent/AU2001273963A1/en not_active Abandoned
  • 2001-04-24 DE DE60120147T patent/DE60120147T2/de not_active Expired - Fee Related
  • 2001-04-24 JP JP2001580225A patent/JP2003531942A/ja active Pending
  • 2001-04-24 AT AT01940358T patent/ATE306518T1/de not_active IP Right Cessation

Patent Citations (1)

Non-Patent Citations (4)

Also Published As

Similar Documents

Legal Events