CN1248226A - Hydrophobic silica gels with reduced surface area - Google Patents
Hydrophobic silica gels with reduced surface area Download PDFInfo
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- CN1248226A CN1248226A CN98802755A CN98802755A CN1248226A CN 1248226 A CN1248226 A CN 1248226A CN 98802755 A CN98802755 A CN 98802755A CN 98802755 A CN98802755 A CN 98802755A CN 1248226 A CN1248226 A CN 1248226A
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B33/00—Silicon; Compounds thereof
- C01B33/113—Silicon oxides; Hydrates thereof
- C01B33/12—Silica; Hydrates thereof, e.g. lepidoic silicic acid
- C01B33/16—Preparation of silica xerogels
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09C—TREATMENT OF INORGANIC MATERIALS, OTHER THAN FIBROUS FILLERS, TO ENHANCE THEIR PIGMENTING OR FILLING PROPERTIES ; PREPARATION OF CARBON BLACK ; PREPARATION OF INORGANIC MATERIALS WHICH ARE NO SINGLE CHEMICAL COMPOUNDS AND WHICH ARE MAINLY USED AS PIGMENTS OR FILLERS
- C09C1/00—Treatment of specific inorganic materials other than fibrous fillers; Preparation of carbon black
- C09C1/28—Compounds of silicon
- C09C1/30—Silicic acid
- C09C1/3081—Treatment with organo-silicon compounds
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/60—Particles characterised by their size
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/12—Surface area
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2006/00—Physical properties of inorganic compounds
- C01P2006/90—Other properties not specified above
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Abstract
The present invention relates to hydrophobic silica gels having reduced surface area and a method for their preparation. The method comprises three steps, where in the first step a mixture comprising a silica hydrosol and colloidal silica is formed. In the second step, the mixture is heat treated in the presence of a strong mineral acid at a pH less than about 1 to form a silica hydrogel having incorporated therein colloidal silica. In the third step, the silica hydrogel is contacted with an organosilicon compound in the presence of a catalytic amount of a strong acid to effect hydrophobing of the silica hydrogel thereby forming a hydrophobic silica gel having a surface area within a range of about 100 m<2>/g to 450 m<2>/g as measured in the dry state. In a preferred method, the hydrophobic silica gel is contacted with a sufficient quantity of an organic solvent immiscible with water to convert the hydrophobic silica hydrogel into a hydrophobic silica organogel.
Description
Background of invention
The present invention relates to have dewatering silica gel and its preparation method that reduces surface-area.This method comprised for three steps, wherein formed the mixture that comprises the silicon water-sol (silica hydrosol) and colloidal silica in the first step.In second step, with this mixture pH be lower than about 1 and strong inorganic acid in the presence of thermal treatment formation wherein be mixed with the silicone-hydrogel (silicahydrogel) of colloidal silica.In the 3rd step, silicone-hydrogel contacted with silicoorganic compound in the presence of the strong acid of catalytic amount silicone-hydrogel is carried out hydrophobic treatment, forming surface-area thus is about 100m
2/ g to 450m
2The dewatering silica gel of/g (under dry state, measuring).In a preferred method, dewatering silica gel is contacted with the water organic solvent immiscible of q.s, make the hydrophobic silicon hydrogel be converted into hydrophobic silicon organogel (silica organogel).Then can remove organic solvent formation surface-area from organogel is about 100m
2/ g to 450m
2The dewatering silica gel of/g (under dry state, measuring).The water-soluble cpds that can add cerium or iron in second step is to improve the thermostability of dewatering silica gel.
Although the dewatering silica gel by the inventive method preparation can be used in a lot of aspects such as the natural rubber thermal isolation, enhancing and increment filler and as the filler in the float gear, they are particularly suitable for being used as reinforcing filler in rubber composition.As everyone knows, the silicon rubber that is only formed by polydiorganosiloxane fluid or natural gum sulfuration has low elongation and tensile strength values usually.A kind of method of improving these silicon rubber physicalies relates to the enhancing silica filler and adds in fluid or the natural gum before sulfuration.Yet the silicon-dioxide reinforcing filler has and polydiorganosiloxane fluid or gummy interactional trend, causes the phenomenon that is commonly referred to " crape sclerosis (crepehardening) ".For handle with organosilane or organo-siloxane strengthen silica filler the surface so that silica sphere is hydrophobic, the past has been carried out a lot of trials.This surface treatment reduces or has eliminated composition crape hardened trend, and has improved the physicals of sulphurated siliastic.
The US3 of Brown, 024,126 disclose by preformed enhancing silica filler use silicoorganic compound in organic solvent, amount to the lower molecular weight organo-siloxane that contains 0.1 to 2 hydroxyl and/or alkoxyl group and small amount of amine, quaternary ammonium or organometallic compound processing and make its hydrophobic method as organic silane or each Siliciumatom.
The US3 of Lewis, 979,546 disclose by using alpha-alkoxy base-ω-pure and mild alcohol of siloxanes to make the method that strengthens the silica filler surface hydrophobicity under mild conditions.Disclosed filler is the preliminary shaping solid.
The US3 of Tyler, 015,645 discloses by silicoorganic compound such as dimethyldichlorosilane(DMCS) or trimethylammonium methoxy silane and silicon organogel reacted, removed then the method that volatile matter prepares hydrophobic silica powder in the presence of an acidic catalyst.This method need prepare silicone-hydrogel, and silicone-hydrogel is by being converted into the silicon organogel with the water in the organic solvent replacing water gel.
The US3 of Lentz, 122,520 disclose a kind of method, wherein at first the acid silicon water-sol are added thermosetting and strengthen silicon dioxide structure, mix with silicoorganic compound, acid catalyst and water organic solvent immiscible then and produce the water drain silica filler.The disclosed silicoorganic compound of Lentz only limit to wherein to have those compounds that are lower than 6 carbon atoms with the organic group of silicon atom bonding, do not have with the substituent silicoorganic compound of the organic functional of silicon atom bonding and do not have silicoorganic compound with the hydrogen of silicon atom bonding.
The US2 of Alexander, 892,797 have described by the silicon sol of modification with the solution-treated of metallide, and silica dioxide granule is by the coating of the chemical combination attitude metallic molecule layer of no more than one deck like this, and described chemical combination attitude metal forms insoluble silicate at pH5 to 12 time.Disclose aluminium, tin, zinc and lead and be preferred metal.People such as Alexander instruction, the silicon sol that has metal according to their invention at particle surface has the stability of increase under extreme pH.
People's such as Termin US3,850,971 and people's such as Termin US4,006,175 discloses the about 50m of specific surface area
2/ g to 1000m
2The porous silicic acid of/g can be by using water hydrolysis methyl silicate or ethyl ester or poly-methyl silicate or the ethyl ester preparation by stoichiometry about 70 to 120% under mild stirring.People such as Termin instruct transition metal such as ferriferous oxide and chromated oxide to can be used as the hydrolytic activation agent, and these metals can be present in the finished product.
People's such as Nauroth US4,360,388 disclose the precipitated silica that contains cerium.People such as Nauroth have instructed with the precipitated silica enhanced rubber composition that contains cerium and have shown fabulous thermostability, and this precipitated silica that contains cerium plays the effect of fire retardant.
People's such as Nauroth US4,208,316 disclose hydrophobic precipitated silica purposes as reinforcing filler in plastic material, this plastic material formation elastomerics that can harden.These elastomericss comprise silicone elastomer.
By the dewatering silica gel of the inventive method preparation with do not have the silica gel for preparing under the colloidal silica to compare to have improved and the consistency polydiorganosiloxane polymkeric substance.Therefore, the present invention's dewatering silica gel of being mixed with colloidal silica is particularly suitable for being used as reinforcing filler in can vulcanizing the composition that forms silicon rubber.With do not mix comparing as the composition of reinforcing filler of colloidal silica with dewatering silica gel, these vulcanising compositions have improved physicals as tearing and tensile strength.
The present invention's general introduction
The present invention relates to have dewatering silica gel and its preparation method that reduces surface-area.This method comprised for three steps, wherein formed the mixture that comprises the silicon water-sol and colloidal silica in the first step.In second step, with this mixture pH be lower than about 1 and strong inorganic acid in the presence of thermal treatment formation wherein be mixed with the silicone-hydrogel of colloidal silica.In the 3rd step, silicone-hydrogel contacted with silicoorganic compound in the presence of the strong acid of catalytic amount silicone-hydrogel is carried out hydrophobic treatment, forming surface-area thus is about 100m
2/ g to 450m
2The dewatering silica gel of/g (under dry state, measuring).In a preferred method, dewatering silica gel is contacted with the water organic solvent immiscible of q.s, make the hydrophobic silicon hydrogel be converted into the hydrophobic silicon organogel.Then can remove organic solvent formation surface-area from the hydrophobic silicon organogel is about 100m
2/ g to 450m
2The dewatering silica gel of/g (under dry state, measuring).
The present invention describes
The present invention has dewatering silica gel and its preparation method that reduces surface-area.The method for preparing dewatering silica gel comprises: (A) formation comprises that (i) comprises about 0.02g to 0.5g SiO
2/ ml and average particle size particle size are lower than the silicon water-sol of 4nm and (ii) about average particle size particle size of 0.1 to the 50wt% mixture of the colloidal silica of 4nm at least, (B) with this mixture pH be lower than about 1 and strong inorganic acid in the presence of form the silicone-hydrogel that wherein is mixed with colloidal silica at about 20 to the 250 ℃ of scope internal heating of temperature, (B) strong acid of this silicone-hydrogel with (1) catalytic amount is contacted, present in an amount at least sufficient to carry out (2) and be selected from general formula R
1 aH
bSiX
4-a-b(1) described organosilane and general formula R
1 nSiO
(4-a)/2(2) reaction of the silicoorganic compound of described organo-siloxane and silicone-hydrogel, forming surface-area is about 100m
2/ g to 450m
2The hydrophobic silicon hydrogel of/g (under dry state, measuring), wherein each R
1Be independently selected from alkyl that comprises about 1 to 12 carbon atom and the organic functional alkyl that comprises about 1 to 12 carbon atom, each X is independently selected from halogen and comprises the alkoxyl group of about 1 to 12 carbon atom, a=0,1,2 or 3, b=0 or 1, a+b=1,2 or 3, condition is when b=1, and a+b=2 or 3, n comprise 2 to 3 integer.
The inventive method is three process that are used to prepare the dewatering silica gel that wherein is mixed with colloidal silica, comprises step (A), (B) and (C).The inventive method step (A) comprises forming and contains average particle size particle size and be lower than the preliminary shaping silicon water-sol of 4nm and the average particle size particle size mixture of the preliminary shaping silicon water-sol (being called " colloidal silica " here) of 4nm at least.
The inventive method step (B) is included in and heats the silicone-hydrogel that the mixture formation that contains the silicon water-sol and colloidal silica wherein is mixed with colloidal silica under the strong acid condition.Step (C) comprises that the silicone-hydrogel with preparation in the step (B) contacts with silicoorganic compound, and described silicoorganic compound and silicone-hydrogel reaction obtain the hydrophobic silicon hydrogel.In a preferred method, in step (C), add the water organic solvent immiscible of q.s so that silicone-hydrogel or hydrophobic silicon hydrogel are converted into corresponding organogel.Can from the hydrophobic silicon organogel, remove the formation dewatering silica gel that desolvates then.Have the surface-area of reduction by the dewatering silica gel of the inventive method preparation, it has improved and has been blended into the easiness in the rubber composition and it is adapted in these compositions as reinforcing filler.
The method that is used to prepare the silicon water-sol is unimportant, can be the known any method of those skilled in the art.Term used herein " the silicon water-sol " is meant that average particle size particle size is lower than the silicon water-sol of 4nm.The silicon water-sol that is used for the inventive method can carry out deionization to water glass by the method that for example makes spent ion exchange resin and prepare.The silicon water-sol can be by hydrolysising silane preparation at low temperatures.The silicon water-sol can prepare by the acidifying sodium silicate mixture.
In the methods of the invention, the silicon water-sol provides about 0.02g to 0.5g SiO
2/ ml mixture.The silicon water-sol preferably provides about 0.05g to 0.2g SiO
2/ ml mixture.
The mixture of the inventive method requires to exist about colloidal silica of 0.1 to 50wt% (by the mixture total weight amount).Term used herein " colloidal silica " is meant the average particle size particle size silicon water-sol of 4nm at least.This mixture preferably includes about 10 to 30wt% colloidal silicas (by the mixture total weight amount).Usually, the colloidal silica that is applicable to the inventive method and composition can be described as any moment during its preparation and does not have the colloidal state soft silica of gel.The method for preparing colloidal silica is unimportant for the inventive method and composition, can be any method known in the art.Colloidal silica can be by for example being mixed with soluble metal silicate such as sodium silicate aqueous solution and acid, and colloidal particles is grown in weakly alkaline solution like this, until reaching required particle size.Colloidal silica preferably has average particle size particle size 4 to about 300nm, and more preferably from about 6 to 100nm.
In step (B), the mixture that comprises the silicon water-sol and colloidal silica must comprise the strong inorganic acid of enough concentration, so that the pH of mixture is lower than about 1.The strong inorganic acid that preferably should have q.s, so that pH is essentially 0, pH energy measurement not in other words.For the present invention, can use any strong inorganic acid.Term used herein " strong inorganic acid " be meant under 18 ℃ in the 0.1N aqueous solution degree of ionization be those acid of at least 25%.Strong inorganic acid for example can be hydrochloric acid, hydroiodic acid HI, sulfuric acid, nitric acid and phosphoric acid.
In step (B), about 20 to 250 ℃ in the mixture that will comprise the silicon water-sol and colloidal silica, preferred about 75 to 150 ℃, 90 to 110 ℃ of scope internal heating more preferably from about in temperature.
In step (B), change with temperature and acid concentration required heat-up time.Typical temperature is high more and acid concentration is big more, and required heat-up time is short more.Heating steps (B) must proceed to the silicone-hydrogel that wherein is mixed with colloidal silica and reach such structure: promptly the finished product have the about 100m of dry state surface-area after the hydrophobic treatment
2/ g to 450m
2/ g, by the US3 of JACS 60:309 (1938) and Lentz, Brunauer Emmettand Teller (BET) method of describing in 122,520 is measured, here as with reference to introducing.
The surface-area of silicone-hydrogel is unimportant when step (B) finishes, as long as the surface-area of hydrophobic step (C) after drying product is in above-mentioned scope.Usually the surface-area of silicone-hydrogel can reduce by hydrophobic reactant, and reason is to become the Organosilyl that is connected with the silicone-hydrogel surface increases average particle size particle size.The surface-area of silicone-hydrogel can be higher than 450m
2/ g is as long as this surface-area is at 100m after the hydrophobic treatment
2/ g to 450m
2Get final product in/g the scope.For determining to carry out the suitable heating condition during the step (B), must carry out the hydrophobic treatment of step (C), measure products obtained therefrom dry state surface-area then.If products obtained therefrom dry state surface-area is higher than 450m
2/ g, then the sour heating condition of step (B) is too gentle.If products obtained therefrom dry state surface-area is lower than 100m
2/ g, then the sour heat treated condition of step (B) is too harsh.The appropriate acid concentration of implementation step (B), the example of temperature and time provide in the following embodiments.If dewatering silica gel dry state surface-area is higher or lower than above-mentioned scope, then dewatering silica gel strengthening the property in silicone elastomer weakened.
If need, can be before the hydrophobic reactant of implementation step (C) the silicon organogel of step (B) be applied shearing force to reduce the aggregate particle size and to improve the homogeneity of particle size distribution.This shearing force can put on the silicon organogel by any method known in the art.This shearing force for example can apply by mechanism such as high-speed mixer or by ultrasonic.So can make dewatering silica gel have the aggregate particle size and the improved particle size homogeneity of reduction, when this dewatering silica gel is formulated as the silicone elastomer composition, can provide than low viscosity compositions, more stable composition and silicon sulfide elastomerics with the improved transparency and physicals.
In the inventive method step (C), the silicone-hydrogel of step (B) is contacted to carry out the hydrophobization of silica gel with general formula (1) one or more silicoorganic compound with (2) definition in the presence of the strong acid of catalytic amount.In step (C), strong acid can with step (B) in use identical.Yet, if need, can from silicone-hydrogel, wash out before adding silicoorganic compound, simultaneously or the acid that adds afterwards and the strong acid of catalytic amount.For example when silicoorganic compound are chlorosilane, can pass through the on-the-spot strong acid that generates catalytic amount of chlorosilane hydrolysis or chlorosilane hydroxyl reaction direct and silicone-hydrogel.In step (C), do not adopt the restriction of describing in the step (B) to pH.The catalytic amount strong acid that only needs to exist is the amount that silicoorganic compound and silicone-hydrogel are reacted of being enough to.The example of suitable acid comprises hydrochloric acid, sulfuric acid and Phenylsulfonic acid.Strong acid catalyst preferably provides pH to be lower than about 2.5 in the step (C).
The temperature of implementing hydrophobic step (C) is unimportant, can be about 20 to 250 ℃.Usually, hydrophobic step (C) is preferably carried out under about 30 to 150 ℃ of temperature.Hydrophobic step (C) can be carried out under the water organic solvent immiscible reflux temperature of (when existing).
In step (C), with silicone-hydrogel and general formula (1) or (2) described reactive organic silicon compound of step (B).In general formula (1) and (2), each R
1Be independently selected from alkyl that comprises about 1 to 12 carbon atom and the organic functional alkyl that comprises about 1 to 12 carbon atom.R
1Can be saturated or unsaturated alkyl.R
1Can be and replace or unsubstituting hydrocarbyl.R
1Can be alkyl such as methyl, ethyl, propyl group, the tertiary butyl, hexyl, heptyl, octyl group, decyl and dodecyl; Alkenyl such as vinyl, allyl group and hexenyl; Substituted alkyl such as chloromethyl, 3,3,3-trifluoro propyl and 6-chlorine hexyl; With aryl such as phenyl, naphthyl and tolyl.R
1Can be and comprise the 1 organic functional alkyl to about 12 carbon atoms, wherein the organic moiety of group can be replaced by reactive atomic or group such as sulfydryl, disulphide, polysulfide, amino, carboxylic acid, methyl alcohol, ester or amide group.Preferred organic functional alkyl is those groups with disulphide or polysulfide functional group.
In general formula (1), each X is independently selected from halogen and comprises the alkoxyl group of about 1 to 12 carbon atom.When X was halogen, halogen was preferably chlorine.When X was alkoxyl group, X can be for example methoxyl group, oxyethyl group and propoxy-.X is preferably selected from chlorine atom and methoxyl group.
The viscosity of the described organo-siloxane of general formula (2) is unrestricted and can be fluid to gummy viscosity.Usually, the organo-siloxane of higher molecular weight can react itself and silicone-hydrogel by the acidic conditions of the inventive method cracking.
Can general formula (1) or (2) described simplification compound or provide organic silicon compound to the inventive method with the form of mixtures of general formula (1) or (2) described two or more silicoorganic compound.
The example of suitable silicoorganic compound comprises diethyl dichlorosilane, the allyl methyl dichlorosilane, dichloromethyl phenylsilane, the phenylethyl diethoxy silane, 3,3,3-trifluoro propyl dimethyl dichlorosilane (DMCS), the trimethylammonium butoxy silane, symmetry phenylbenzene tetramethyl disiloxane, divinyltetraphenylcy,lotrisiloxane, hexaethyldisiloxane, the amyl group dimethyl dichlorosilane (DMCS), divinyl dipropoxy silane, vinyl-dimethyl base chlorosilane, the vinyl dimethyl dichlorosilane (DMCS), the vinyl-dimethyl methoxylsilane, trimethylchlorosilane, hexamethyldisiloxane, the hexenyl dimethyl dichlorosilane (DMCS), the hexenyl dimethylchlorosilane, dimethylchlorosilane, dimethyldichlorosilane(DMCS), mercapto propyl group methyl dimethoxysilane and two { 3-(triethoxysilyl) propyl group } tetrasulfide.When dewatering silica gel was used as filler in silicon rubber, silicoorganic compound were preferably hexamethyldisiloxane or dimethyldichlorosilane(DMCS).
The amount that adds the silicoorganic compound in the inventive method should be enough to make silicone-hydrogel fully hydrophobic, so that the dewatering silica gel that is fit to intended purpose to be provided.Usually, should there be at least 0.04 Organosilyl unit/SiO in the amount of the silicoorganic compound in adding the inventive method in silicone-hydrogel
2The unit, SiO
2The unit comprises that by the silicon water-sol and colloidal silica the two provides.The silicoorganic compound amount upper limit that adds in the inventive method is unimportant, makes the saturated required amount of silica gel will play effect as this method solvent because be in excess in.
The hydrophobic silicon hydrogel of step (C) can directly use maybe can be by recycling such as centrifugal or filtering method.The hydrophobic silicon hydrogel can be by adopting such as heating or decompression or heating and the method drying that reduces pressure and combine.
In a preferred method, add the water organic solvent immiscible of q.s, so that silicone-hydrogel or hydrophobic silicon hydrogel are converted into corresponding organogel.This organic solvent can be before adding silicoorganic compound, add simultaneously or afterwards.In other words, silicone-hydrogel can carry out hydrophobization then by at first being converted into organogel with the organic solvent replacing water.On the other hand, silicoorganic compound and organic solvent can be added in the silicone-hydrogel simultaneously.Under these conditions, the reaction of silicone-hydrogel and silicoorganic compound and can carry out simultaneously with the water in the organic solvent displacement hydrophobic silicon hydrogel.At last, can add silicoorganic compound before adding organic solvent, silicone-hydrogel and reactive organic silicon compound make products obtained therefrom be converted into organogel by adding organic solvent then in the case.For back two kinds of situations, realize conversion to the silicon organogel by being separated, wherein the hydrophobic silicon organogel is fed organic solvent mutually in.Preferable methods is, adds the entry organic solvent immiscible after forming the hydrophobic silicon hydrogel, forms the hydrophobic silicon organogel thus.
For the present invention, can use any and the immiscible organic solvent of water.Suitable water immiscible solvent comprises low-molecular-weight siloxane such as hexamethyldisiloxane, octamethylcyclotetrasiloxane, phenylbenzene tetramethyl disiloxane and the end capped polydimethylsiloxane fluid of trimethyl silyl.When siloxanes when the solvent, it can play solvent and with the effect of the reagent of silicone-hydrogel.In addition, suitable solvent comprises aromatic hydrocarbons such as toluene and dimethylbenzene; Heptane and other aliphatic hydrocarbon solvent; Naphthenic hydrocarbon such as hexanaphthene, ether such as diethyl ether and dibutyl ether, halogenated hydrocarbon solvent such as methylene dichloride, chloroform, ethylene chloride and chlorobenzene; And ketone such as methyl iso-butyl ketone (MIBK).
The amount of water organic solvent immiscible is unimportant, makes the hydrophobic silicon hydrogel be converted into enough solvents of silicon organogel as long as exist.The boiling point of solvent preferably should be lower than about 250 ℃ to be removed from the hydrophobic silicon organogel helping, yet boiling point is unimportant, desolvates because can remove from the hydrophobic silicon organogel by centrifugal or other suitable manner.
After silicone-hydrogel was converted into the hydrophobic silicon organogel, products obtained therefrom can directly use.In other words, this hydrophobic silicon organogel can be directly be used as toughener in silicon rubber maybe can use any other field of this series products.In addition, can be except that desolvating and using the dry dewatering silica gel that obtains from the hydrophobic silicon organogel.
During implementation step (C), for helping the reaction of silicoorganic compound and silicone-hydrogel, it is suitable adding tensio-active agent or the miscible solvent of water.Can under the water organic solvent immiscible that exists or do not exist in the adding method, add tensio-active agent or the miscible solvent of water.Suitable tensio-active agent can comprise anion surfactant such as Witco 1298 Soft Acid, nonionogenic tenside such as polyethylene oxide (23) lauryl ether and (Me
3SiO)
2MeSi (CH
2)
3(OCH
2CH
2)
7OMe, wherein Me is methyl and cats product such as N-alkyl trimethyl ammonium chloride.The miscible solvent of suitable water can comprise that alcohol is as ethanol, propyl alcohol, Virahol, propyl carbinol and tetrahydrofuran (THF).
In the inventive method step (C), can add the thermally-stabilised reagent of water-soluble cerium of being selected from of significant quantity and iron cpd.Term " significant quantity " is meant that the water-soluble cerium that exists in the dewatering silica gel or the concentration of iron cpd should be enough to provide improved thermostability to those compositions that wherein add dewatering silica gel.These compositions can comprise for example silicon rubber, natural rubber and synthetic organic rubber.
Usually, think that set by step the water-soluble cpds that component (not comprising solvent) volume in (C) is counted about 0.01%wt/vol to 10%wt/vol cerium or iron can be used for the inventive method.It is preferred that the water-soluble cpds of cerium or iron accounts for about 0.1%wt/vol to 1%wt/vol (by same basic).
The example that can be used for the water-soluble cpds of the inventive method comprises FeCl
3, FeBr
2, FeBr
3.6H
2O, FeCl
2.4H
2O, FeI
2.4H
2O, Fe (NO
3)
3.6H
2O, FePO
4.2H
2O, CeCl
3.9H
2O, CeBr
3.H
2O, CeI
3.9H
2O, Ce (NO
3)
3.6H
2O and Ce (SO
4)
2.2H
2O.Be used for the cerium of the inventive method or the preferably water soluble compound of iron and be selected from FeCl
3And CeCl
3.9H
2O.
Provide following embodiment that the present invention is described.These embodiment are not used in the scope that limits claim of the present invention.Embodiment 1
With hexamethyldisiloxane the silica gel that wherein is mixed with colloidal silica is carried out hydrophobization.(PQ Corporation, Valley Forge is PA) with the dilution of 1350ml deionized water with 750ml PQ N transparent silicic acid sodium.This solution is comprised that with what the speed adding of 420ml/min was stirred fast (Fair Lawn is in solution NJ) for FisherCertified, Fisher Scientific with the 620ml water-reducible 280ml concentrated hydrochloric acid of deionization (HCl).The gained mixture was stirred 2 minutes, then with sodium silicate solution with pH regulator to 2.5.The 3100ml silicon water-sol that obtains contains 0.1g SiO
2/ ml.
Will be by the silicon water-sol for preparing as mentioned above by pump into 1500ml Dowex 50WX8-100 ion exchange resin (the The DowChemical Company that is filled with sour form with speed 60ml/min, Midland is in 1.5m MI) * 5cm pillar and deionizing.The pH of monitoring pillar effluent liquid drops to until pH and is lower than 0.5, collects 2000-2400ml deionization silicon water-sol effluent liquid subsequently this moment.
By the 1L deionization silicon water-sol being put into the 5L flask and under agitation being added 273ml colloidal silica (Ludox SM, DuPont Chemicals, Wilmington, DE, average particle size particle size 10nm) and the dense HCl of 392ml (Fisher Certified), make this deionization silicon water-sol agglomeration.The silicone-hydrogel that will form behind adding HCl several minutes forms the agglomeration silicone-hydrogel suspension that wherein is mixed with colloidal silica thus by the vigorous stirring fragmentation.This silicone-hydrogel suspension 100 ℃ of following heat treated 3 hours, is cooled to room temperature then.
With this thermal treatment silicone-hydrogel suspension hydrophobization as follows.Under agitation add the 555ml Virahol in the thermal treatment silicone-hydrogel suspension, then add the 288ml hexamethyldisiloxane to this.The gained mixture was at room temperature stirred 1 hour.Then, 1L toluene is added in this mixture.With this mixture mild stirring 5 minutes again, stop to stir, and get rid of water from drag.Toluene is used the 500ml deionized water wash mutually.Then flask is loaded onto dean stark trap and toluene is refluxed mutually to remove residual water.Remaining dewatering silica gel product is removed in the distillation under reduced pressure of toluene phase.With this dewatering silica gel 150 ℃ of dried overnight, to remove residual toluene.The output of this dewatering silica gel is 202g.Embodiment 2
With hexamethyldisiloxane the silica gel that wherein is mixed with colloidal silica is carried out hydrophobization.Press the deionization of preparation described in the embodiment 1 silicon water-sol.By the 1L deionization silicon water-sol being put into the 5L flask and under agitation being added 216ml colloidal silica (Nalco 1050, Nalco Chemicals Co., Chicago IL) with the dense HCl of 375ml (FisherCertified), makes this deionization silicon water-sol agglomeration.The silicone-hydrogel that will form behind adding HCl several minutes forms the agglomeration silicone-hydrogel suspension that wherein is mixed with precipitated silica thus by the vigorous stirring fragmentation.With this silicone-hydrogel suspension reflux 3 hours, be cooled to room temperature then.
With this heat-treatment silicone-hydrogel suspension hydrophobization as follows.Under agitation add the 530ml Virahol in the thermal treatment silicone-hydrogel suspension, then add the 100ml hexamethyldisiloxane to this.The gained mixture was at room temperature stirred 1 hour.Then, 1.3L toluene is added in this mixture.With gained mixture mild stirring 5 minutes again, stop to stir, and get rid of water from drag.Toluene is used the 500ml deionized water wash mutually.Then flask is loaded onto dean stark trap and toluene is refluxed mutually to remove residual water.Go into the toluene phase transition in the open container in the stink cupboard and make toluene evaporates, remaining dewatering silica gel product.With this dewatering silica gel 150 ℃ of dryings 4 hours, to remove residual toluene.The output of this dewatering silica gel is 267g.Measure the BET surface-area of dry dewatering silica gel by above-described method, the result provides in table 1.Embodiment 3
With hexamethyldisiloxane the silica gel that wherein is mixed with colloidal silica is carried out hydrophobization.Press the deionization of preparation described in the embodiment 1 silicon water-sol.By the 1L deionization silicon water-sol being put into the 5L flask and under agitation being added about 130ml colloidal silica (Nalco 1140, Nalco Chemicals Co.) and the dense HCl of 375ml (Fisher Certified), make this deionization silicon water-sol agglomeration.The silicone-hydrogel that will form behind adding HCl several minutes forms the agglomeration silicone-hydrogel suspension that wherein is mixed with colloidal silica thus by the vigorous stirring fragmentation.With this silicone-hydrogel suspension reflux 3 hours, be cooled to room temperature then.
With this heat-treatment silicone-hydrogel suspension hydrophobization as follows.Under agitation add the 530ml Virahol in the thermal treatment silicone-hydrogel suspension, then add the 100ml hexamethyldisiloxane to this.The gained mixture was at room temperature stirred 1 hour.Then, 1750ml toluene is added in this mixture.With gained mixture restir 5 minutes, stop to stir, and get rid of water from drag.Toluene is used the 500ml deionized water wash mutually.Then flask is loaded onto dean stark trap and toluene is refluxed mutually to remove residual water.Go into the toluene phase transition in the open container in the stink cupboard and make toluene evaporates, remaining dewatering silica gel product.With this dewatering silica gel 150 ℃ of dryings 4 hours, to remove residual toluene.The output of this dewatering silica gel is 186g.Measure the BET surface-area of dry dewatering silica gel by the method for describing among the embodiment 2, the result provides in table 1.Embodiment 4
Preparation is with the hexamethyldisiloxane hydrophobization and by adding FeCl
3The heat-staple silica gel that wherein is mixed with colloidal silica.400ml PQ N transparent silicic acid sodium (PQ Corporation) is diluted with the 600ml deionized water.The speed of this solution with 375ml/min is added in the stirred solution that comprises with the dense HCl of the water-reducible 440ml of 560ml deionization (Fisher Certified), and formation comprises 0.08g SiO
2The silicon water-sol of/ml.After adding water glass in the HCl solution fully, under continuously stirring, add 309ml Ludox HS (DuPontChemicals) immediately.The gained 2L silicon water-sol is filtered by the sintered glass filter funnel and this silicon water-sol is poured in the dish.The gelling in about 35 minutes of this silicon water-sol, and after gelling, placed 1 hour.Is about 2.1 into about the square of 1cm and with deionized water wash until the pH of effluent with the cutting of gained silicone-hydrogel.Washed silicone-hydrogel is put into the 5L flask and add the dense HCl of 839ml (Fisher Certified), the gained mixture heating up was refluxed 5 hours.Silicone-hydrogel after refluxing is cooled to room temperature.
With this thermal treatment silicone-hydrogel suspension hydrophobization as follows.Under agitation in this silicone-hydrogel, add 1049ml Virahol, 543ml hexamethyldisiloxane and 8.3gFeCl
3After material in the flask at room temperature stirred 1 hour, add 2L toluene.With the mild stirring after 5 minutes again of the material in this flask, stop to stir, and get rid of water from drag.Toluene is used the 500ml deionized water wash mutually.Then flask is loaded onto dean stark trap and toluene is refluxed mutually to remove residual water.After the backflow, remove toluene, remaining dewatering silica gel product by distillation under reduced pressure.With this dewatering silica gel 150 ℃ of dried overnight.The output of this drying dewatering silica gel is 299g.Measure the BET surface-area by the method that embodiment 2 describes.(Perkin Elmer Corporation, Norwalk is CT) by the CHN assay determination with Perkin Elmer Model 2400CHN elemental analyser for the carbon of this dried dewatering silica gel and hydrogen richness.The iron level of this dried dewatering silica gel passes through atomic absorption detecting.These analytical resultss provide in table 1.Embodiment 5
Preparation is with the hexamethyldisiloxane hydrophobization and by adding FeCl
3The heat-staple silica gel that wherein is mixed with colloidal silica.Comprise about 0.1gSiO according to preparation described in the embodiment 1
2The silicon water-sol of/ml, and to its deionization.The 1L deionization silicon water-sol is put into the 5L flask and under agitation added 273ml Ludox SM (DuPont Chemicals), then add the dense HCl of 392ml.The silicone-hydrogel that will form behind adding HCl several minutes forms silicone-hydrogel suspension thus by the vigorous stirring fragmentation.This silicone-hydrogel suspension 100 ℃ of following heat treated 3 hours, is cooled to room temperature then.
With this thermal treatment silicone-hydrogel hydrophobization as follows.Under agitation in this silicone-hydrogel, add 555ml Virahol, 288ml hexamethyldisiloxane and 2.7g FeCl
3The gained mixture was at room temperature stirred 1 hour, then 1L toluene is added in the mixture.With this mixture mild stirring after 5 minutes again, stop to stir, and get rid of water from drag.Toluene is used the 500ml deionized water wash mutually.Then flask is loaded onto dean stark trap and toluene is refluxed mutually to remove residual water.With the underpressure distillation of toluene phase, remaining dewatering silica gel product.This dewatering silica gel is removed residual toluene 150 ℃ of dried overnight.The output of this drying dewatering silica gel is 210g.The methods analyst of describing according to embodiment 4 is the exsiccant dewatering silica gel, to measure surface-area, carbon and hydrogen richness and iron level.The result of this analysis provides in table 1.Embodiment 6
Preparation is with hexamethyldisiloxane and vinyl-dimethyl base chlorosilane hydrophobization and pass through to add FeCl
3The heat-staple silica gel that wherein is mixed with colloidal silica.According to the deionization of preparation described in the embodiment 1 silicon water-sol.The deionization silicon water-sol of 1L is put into the 5L flask also under agitation to add 273ml colloidal silica (Ludox SM, DuPont Chemicals) and the dense HCl of 392ml (Fisher Certified) and makes its agglomeration.This mixture is formed the suspension that comprises the silicone-hydrogel that wherein is mixed with colloidal silica by stirring and refluxing thermal treatment in 3 hours.The heat treated silicone-hydrogel of gained is cooled to room temperature.
With this thermal treatment silicone-hydrogel hydrophobization as follows.Under agitation in this heat-treatment silicone-hydrogel, add 555ml Virahol, 78ml hexamethyldisiloxane and 2.7gFeCl
3The gained mixture was at room temperature stirred 1 hour, then 2L toluene is added in the mixture.With this mixture stirred for several minute, stop to stir, and get rid of water from drag.Toluene is used the 1L deionized water wash mutually.To handle flask then loads onto dean stark trap and toluene is refluxed mutually to remove residual water.Toluene is heated to remove remaining hexamethyldisiloxane down at 110 ℃, add 5ml vinyl-dimethyl base chlorosilane then.This mixture was refluxed 1 hour and be cooled to room temperature.Will be about the 50ml deionized water add in the flask and wash out remaining HCl, and toluene is refluxed mutually to remove residual water.Go into the toluene phase transition in the open container in the stink cupboard and make toluene evaporates, remaining dewatering silica gel product.With this dewatering silica gel 85 ℃ of dried overnight.The output of this drying dewatering silica gel is 214g.The physicals of the dry dewatering silica gel of choosing characterizes by standard method, and gained is the result provide in table 2.Embodiment 7
Preparation is with hexamethyldisiloxane and vinyl-dimethyl base chlorosilane hydrophobization and pass through to add FeCl
3The heat-staple silica gel that wherein is mixed with colloidal silica.Before hydrophobization, this silicone-hydrogel carried out shearing treatment to reduce the aggregate particle size and to improve the homogeneity of particle size distribution.Prepare the deionization silicon water-sol by being similar to the method for describing among the embodiment 1.By the 1L deionization silicon water-sol being added in the 5L flask and under agitation adding 273ml colloidal silica (Ludox SM, DuPont Chemicals) and the dense HCl of 392ml (FisherCertified) makes its agglomeration.This mixture is formed the suspension that comprises the silicone-hydrogel that wherein is mixed with colloidal silica by stirring and refluxing thermal treatment in 3 hours.
After being cooled to room temperature, with this silicone-hydrogel the Waring mixing roll (Model 7011, Waring Products Division of Dynamics Corporation of America, New Hartford sheared 2 minutes in CT), sent back to then in the 5L flask.
With this silicone-hydrogel hydrophobization as follows of thermal treatment and shearing.Under agitation in this silicone-hydrogel, add 555ml Virahol, 117ml hexamethyldisiloxane and 2.7gFeCl
3The gained mixture was at room temperature stirred 1 hour, then 2L toluene is added in the mixture.With this mixture stirred for several minute, stop to stir, and get rid of water from drag.Toluene is used the 1L deionized water wash mutually.Then flask is loaded onto dean stark trap and toluene is refluxed mutually to remove residual water.Toluene is heated to remove remaining hexamethyldisiloxane down at 110 ℃, add 5ml vinyl-dimethyl base chlorosilane then.This mixture was refluxed 1 hour and be cooled to room temperature.Will be about the 50ml deionized water add in the flask and wash out remaining HCl, and toluene is refluxed mutually to remove residual water.Go into the toluene phase transition in the open container in the stink cupboard and make toluene evaporates, remaining dewatering silica gel product.With this dewatering silica gel 85 ℃ of following dried overnight.The output of this drying dewatering silica gel is 209g.The physicals of the dry dewatering silica gel of choosing characterizes by standard method, and gained is the result provide in table 2.Embodiment 8
Preparation is with hexamethyldisiloxane and vinyl-dimethyl base chlorosilane hydrophobization and pass through to add FeCl
3The heat-staple silica gel that wherein is mixed with colloidal silica.Before hydrophobization, this silicone-hydrogel carried out shearing treatment to reduce the aggregate particle size and to improve the homogeneity of particle size distribution.Prepare the deionization silicon water-sol by being similar to the method for describing among the embodiment 1.By the 1.5L deionization silicon water-sol being added in the 5L flask and under agitation adding 409.5ml colloidal silica (Ludox SM, DuPont Chemicals) and the dense HCl of 588ml (FisherCertified) makes its agglomeration.This mixture is formed the suspension that comprises the silicone-hydrogel that wherein is mixed with colloidal silica by stirring and refluxing thermal treatment in 3 hours.
After being cooled to room temperature, this silicone-hydrogel was sheared 2 minutes in Waring mixing roll (Model 7011), sent back to then in the 5L flask.
With this silicone-hydrogel suspension hydrophobization as follows of thermal treatment and shearing.Under agitation in this silicone-hydrogel suspension, add 832.5ml Virahol, 175ml hexamethyldisiloxane and 4g FeCl
3The gained mixture was at room temperature stirred 1 hour, then 3.2L toluene is added in the mixture.With this mixture stirred for several minute, stop to stir, and get rid of water from drag.Toluene is used the 1L deionized water wash mutually.Then flask is loaded onto dean stark trap and toluene is refluxed mutually to remove residual water.Toluene is heated to remove remaining hexamethyldisiloxane down at 110 ℃, add 3.75ml vinyl-dimethyl base chlorosilane then.This mixture was refluxed 1 hour and be cooled to room temperature.Will be about the 50ml deionized water add in the flask and wash out remaining HCl, and toluene is refluxed mutually to remove residual water.Go into the toluene phase transition in the open container in the stink cupboard and make toluene evaporates, remaining dewatering silica gel product.With this dewatering silica gel 85 ℃ of following dried overnight.The output of this drying dewatering silica gel is 292g.The physicals of the dry dewatering silica gel of choosing characterizes by standard method, and gained is the result provide in table 2.Embodiment 9
To be blended in the liquid-state silastic compositions according to each dry dewatering silica gel of embodiment 1 to 5 preparation, with said composition sulfuration and mensuration physicals.Each dry dewatering silica gel of 38 weight parts/100 part (pph) is blended into to contain vinyl that about 0.15mol% replaces on Siliciumatom and plasticity be in about 55 to 65 the polydimethylsiloxane natural gum.Blending 0.7 weight pph2 in this base composition, two (t-butyl peroxy)-2 of 5-, 5-dimethylhexane (by polydimethylsiloxane natural gum weight).With this catalytic base composition by in 34.5MPa and 175 ℃ of following hot pressing sulfuration in 15 minutes for being used to test the suitable configuration of physicals.Following test method is used to test sulfurized silicon rubber: stretch ASTM D412; Elongation, ASTM D412; 100% modulus, ASTM D412; 50% modulus, ASTM D412; Hardness (Shore A), ASTM 2240; Tear (die head B), ASTM D624; Tear (die head C), ASTM D624; Compressive set (at 177 ℃ of following 22h), ASTM D395.Be the sample measurement plasticity of vulcanising composition not of the twice of composition proportion to weight, these samples are made ball and placement 1 hour before measuring according to ASTM D926.The result of this test provides in following table 1.Embodiment 10
To be blended in the rubber composition according to each dry dewatering silica gel of embodiment 6 to 8 preparations, with said composition sulfuration and mensuration physicals.Each exsiccant dewatering silica gel is blended in the mixture of siloxanes by weight part/100 of describing in the table 2 part (pph).The temperature of carrying out blending also provides in table 2.When this mixture of siloxanes comprises 83.8wt%25 ℃ viscosity be the end capped polydimethylsiloxane of vinyl-dimethyl base siloxy-of 55Pa.s and 16.2wt% when on Siliciumatom, having 2mol% vinyl substituted base and 25 ℃ viscosity be end capped poly-(vinyl methyl) dimethylsiloxane copolymer of vinyl-dimethyl base siloxy-of 0.35Pa.s.In this base composition, blending comprise lower molecular weight polydimethyl (methyl hydrogen) siloxane fluid, platinum dichloride and symmetrical divinyl tetramethyl disiloxane in and the vulcanization system of title complex and 1-ethynylcyclohexanol.With this catalytic base composition by in 34.5MPa and 150 ℃ of following hot pressing sulfuration in 15 minutes for being used to test the suitable configuration of physicals.With this vulcanising composition 177 ℃ of following postcure 1 hour.According to the physicals of these vulcanising compositions of test determines of embodiment 9, the result provides in table 2
Table 1
Physicals with dewatering silica gel enhanced silicon rubber
*-expression do not obtain data
| The embodiment numbering | |||||
| Performance | ???1 | ???2 | ????3 | ???4 | ??5 |
| BET surface-area (m 2/g) | ???- | ???268 | ???361 | ???342 | ??355 |
| Wt% carbon | ???- | ???- | ???- | ???6.3 | ??6.0 |
| Wt% hydrogen | ???- | ???- | ???- | ???1.5 | ??1.5 |
| Wt% iron | ???- | ???- | ???- | ???0.45 | ??0.43 |
| Plasticity | ???142 | ???- | ???- | ???101 | ??113 |
| Stretch (MPa) | ???7.76 | ???4.68 | ???6.55 | ???6.69 | ??7.12 |
| Elongation (%) | ???815 | ???690 | ???785 | ???1291 | ??824 |
| Mo Liang @50% (MPa) | ???0.61 | ???0.52 | ???0.65 | ???0.31 | ??0.54 |
| Mo Liang @100% (MPa) | ???0.89 | ???0.73 | ???0.89 | ???0.49 | ??0.80 |
| Hardness (Shore A) | ???50 | ???- | ???- | ???39 | ??46 |
| Tear B (kN/m) | ???12.43 | ???7.84 | ???11.56 | ???10.50 | ??11.60 |
| Tear C (kN/m) | ???14.53 | ???11.41 | ???13.85 | ???11.20 | ??13.23 |
| Compressive set (%@22h) | ???- | ???- | ???- | ???11 | ??15 |
Table 2
Physicals with dewatering silica gel enhanced silicon rubber
| The embodiment numbering | |||||||
| Performance | ???6 | ????????????7 | ????????????8 | ||||
| BET surface-area (m 2/g) | ???357 | ????????????357 | ????????????372 | ||||
| Void volume (cm 3/g) | ???4.56 | ????????????4.60 | ????????????4.23 | ||||
| Pore volume (cm 3/g) | ???2.49 | ????????????2.47 | ????????????2.37 | ||||
| Mean pore size (dust) | ???173 | ????????????167 | ????????????164 | ||||
| Average particle size particle size (μ m) | ???36.6 | ????????????34.8 | ????????????33.3 | ||||
| Mixing temperature (℃) | ???R.T.* | ??100 | ??60 | ??60 | ??60 | ??60 | ?60 |
| The silica gel umber | ???30 | ??30 | ??35 | ??40 | ??30 | ??35 | ?40 |
| Stretch (MPa) | ???4.71 | ??6.01 | ??6.11 | ??6.58 | ??6.14 | ??6.71 | ?7.20 |
| Elongation (%) | ???217 | ??364 | ??458 | ??410 | ??368 | ??446 | ?472 |
| Mo Liang @100% (MPa) | ???2.97 | ??2.38 | ??2.59 | ??2.75 | ??2.08 | ??2.24 | ?2.45 |
| Hardness (Shore A) | ???58 | ??54 | ??59 | ??62 | ??48 | ??51 | ?57 |
| Tear die head B (kN/m) | ???37.1 | ??38.2 | ??44.5 | ??39.9 | ??38.9 | ??42.4 | ?42.5 |
* room temperature
Claims (24)
1. method for preparing dewatering silica gel comprises:
(A) formation comprises that (i) comprises about 0.02g to 0.5g SiO
2/ ml and average particle size particle size are lower than the silicon water-sol of 4nm and (ii) about average particle size particle size of 0.1 to the 50wt% mixture of the colloidal silica of 4nm at least,
(B) with this mixture pH be lower than about 1 and strong inorganic acid in the presence of about 20 to the 250 ℃ of scope internal heating of temperature form the silicone-hydrogel that wherein is mixed with colloidal silica and
(C) strong acid of this silicone-hydrogel with (1) catalytic amount is mixed, this amount is enough to carry out (2) and is selected from general formula R
1 aH
bSiX
4-a-bDescribed organosilane and general formula R
1 nSiO
(4-n)/2The silicoorganic compound of described organo-siloxane and the reaction of silicone-hydrogel, being formed on the surface-area of measuring under the dry state is about 100m
2/ g to 450m
2The hydrophobic silicon hydrogel of/g, wherein each R
1Be independently selected from alkyl that comprises about 1 to 12 carbon atom and the organic functional alkyl that comprises about 1 to 12 carbon atom, each X is independently selected from halogen and comprises the alkoxyl group of 1 to 12 carbon atom, a=0,1,2 or 3, b=0 or 1, a+b=1,2 or 3, condition is when b=1, and a+b=2 or 3, n comprise 2 to 3 integer.
2. according to the process of claim 1 wherein that this mixture comprises about 0.05 to 0.2gSiO
2/ ml.
3. according to the process of claim 1 wherein that this mixture comprises about colloidal silica of 10 to 30wt%.
4. according to the process of claim 1 wherein that the particle size about 6 of colloidal silica is to 100nm.
5. according to the process of claim 1 wherein this mixture is essentially 0 time heating at pH.
6. according to the process of claim 1 wherein this mixture is essentially 0 time heating at temperature about 75 ℃ to 150 ℃ and pH.
7. according to the method for claim 1, further be included in and carry out step (C) and before the silicone-hydrogel of step (B) is applied shearing force.
8. according to the process of claim 1 wherein that during contact procedure (C), strong acid provides pH to be lower than about 2.5.
9. according to the process of claim 1 wherein that contact procedure (C) carries out under about 20 to 250 ℃ of temperature.
10. according to the process of claim 1 wherein that contact procedure (C) carries out under about 30 to 150 ℃ of temperature.
11. according to the process of claim 1 wherein that silicoorganic compound are organosilane.
12. according to the method for claim 11, wherein organosilane is selected from vinyl-dimethyl base chlorosilane, hexenyl dimethyl dichlorosilane (DMCS), hexenyl dimethylchlorosilane and dimethyldichlorosilane(DMCS).
13. according to the process of claim 1 wherein that silicoorganic compound are organo-siloxane.
14. according to the method for claim 13, wherein organo-siloxane is a hexamethyldisiloxane.
15. according to the process of claim 1 wherein that silicoorganic compound provide the SiO of at least 0.04 Organosilyl unit/silicone-hydrogel
2The unit.
16. according to the method for claim 1, further comprise the hydrophobic silicon hydrogel is contacted with the water organic solvent immiscible of q.s, thus the hydrophobic silicon hydrogel be converted into the hydrophobic silicon organogel
17. according to the method for claim 1, further be included in during the contact procedure (C), have and help silicoorganic compound and silicone-hydrogel reacted surface promoting agent.
18. according to the method for claim 1, further be included in during the contact procedure (C), have the miscible solvent of water that helps silicoorganic compound and silicone-hydrogel reaction.
19., further comprise the thermo-stabilizer of silicone-hydrogel with the water-soluble cpds that is selected from cerium and iron of significant quantity contacted according to the method for claim 1.
20. according to the method for claim 19, wherein the water-soluble cpds of cerium and iron is selected from FeCl
3And CeCl
3.9H
2O.
21. composition by the method preparation of claim 1.
22. composition by the method preparation of claim 7.
23. composition by the method preparation of claim 16.
24. composition by the method preparation of claim 19.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US80600597A | 1997-02-24 | 1997-02-24 | |
| US08/806,005 | 1997-02-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN1248226A true CN1248226A (en) | 2000-03-22 |
Family
ID=25193082
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN98802755A Pending CN1248226A (en) | 1997-02-24 | 1998-02-18 | Hydrophobic silica gels with reduced surface area |
Country Status (8)
| Country | Link |
|---|---|
| EP (1) | EP0963345A1 (en) |
| JP (1) | JP2001513066A (en) |
| KR (1) | KR20000075594A (en) |
| CN (1) | CN1248226A (en) |
| AU (1) | AU6660598A (en) |
| BR (1) | BR9810408A (en) |
| CA (1) | CA2280795A1 (en) |
| WO (1) | WO1998037020A1 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104745145A (en) * | 2013-12-26 | 2015-07-01 | 安集微电子（上海）有限公司 | Preparation method and use of modified silica particles |
| CN107089666A (en) * | 2016-05-28 | 2017-08-25 | 郑善 | A kind of preparation technology of rare earth toughness reinforcing silica aerogel presoma and solid-state silica aerogel |
| CN110589839A (en) * | 2019-09-23 | 2019-12-20 | 东莞创利科技发展有限公司 | Silicon dioxide reinforcing agent and preparation method and application thereof |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6342560B1 (en) * | 1999-08-19 | 2002-01-29 | Ppg Industries Ohio, Inc. | Chemically modified fillers and polymeric compositions containing same |
| JP6405540B2 (en) * | 2014-11-11 | 2018-10-17 | パナソニックＩｐマネジメント株式会社 | Airgel and method for producing the same |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR1092407A (en) * | 1953-10-19 | 1955-04-21 | Du Pont | Surface esterified siliceous solids and their uses |
| GB783868A (en) * | 1954-10-06 | 1957-10-02 | Midland Silicones Ltd | A process of preparing hydrophobic organo-silicon powders |
| US3122520A (en) * | 1959-10-05 | 1964-02-25 | Dow Corning | Method of making silicone rubber fillers |
| SU369131A1 (en) * | 1969-11-12 | 1973-02-08 | ||
| DE2015402A1 (en) * | 1970-04-01 | 1971-10-21 | Bayer | Process for improving the vulcanization behavior and for heat stabilization of polyorganosiloxane elastomers |
| DE3005137A1 (en) * | 1980-02-12 | 1981-08-20 | Degussa Ag, 6000 Frankfurt | CONTAINING PELLETIC SILICONE, METHOD FOR THE PRODUCTION THEREOF, AND ELASTOMERIC LIQUID MEASURES CONTAINING THE CONTAINING PELLETIC SILICONE |
| IT1266660B1 (en) * | 1993-11-04 | 1997-01-09 | Eniricerche Spa | PROCEDURE FOR THE PREPARATION OF POROUS SILICA XEROGELS IN SPHERICAL FORM |
| US5708069A (en) * | 1997-02-24 | 1998-01-13 | Dow Corning Corporation | Method for making hydrophobic silica gels under neutral conditions |
-
1998
- 1998-02-18 JP JP53688398A patent/JP2001513066A/en active Pending
- 1998-02-18 AU AU66605/98A patent/AU6660598A/en not_active Abandoned
- 1998-02-18 KR KR1019997007655A patent/KR20000075594A/en not_active Application Discontinuation
- 1998-02-18 CA CA002280795A patent/CA2280795A1/en not_active Abandoned
- 1998-02-18 CN CN98802755A patent/CN1248226A/en active Pending
- 1998-02-18 BR BR9810408-0A patent/BR9810408A/en not_active Application Discontinuation
- 1998-02-18 EP EP98908610A patent/EP0963345A1/en not_active Withdrawn
- 1998-02-18 WO PCT/US1998/003273 patent/WO1998037020A1/en not_active Application Discontinuation
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104745145A (en) * | 2013-12-26 | 2015-07-01 | 安集微电子（上海）有限公司 | Preparation method and use of modified silica particles |
| CN107089666A (en) * | 2016-05-28 | 2017-08-25 | 郑善 | A kind of preparation technology of rare earth toughness reinforcing silica aerogel presoma and solid-state silica aerogel |
| CN110589839A (en) * | 2019-09-23 | 2019-12-20 | 东莞创利科技发展有限公司 | Silicon dioxide reinforcing agent and preparation method and application thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| WO1998037020A1 (en) | 1998-08-27 |
| JP2001513066A (en) | 2001-08-28 |
| CA2280795A1 (en) | 1998-08-27 |
| AU6660598A (en) | 1998-09-09 |
| EP0963345A1 (en) | 1999-12-15 |
| BR9810408A (en) | 2000-08-22 |
| KR20000075594A (en) | 2000-12-26 |
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