CN1101725C - Method for producing organically modified, permanently hydrophobic aerogels - Google Patents
Method for producing organically modified, permanently hydrophobic aerogels Download PDFInfo
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- CN1101725C CN1101725C CN97181109A CN97181109A CN1101725C CN 1101725 C CN1101725 C CN 1101725C CN 97181109 A CN97181109 A CN 97181109A CN 97181109 A CN97181109 A CN 97181109A CN 1101725 C CN1101725 C CN 1101725C
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- gel
- lyogel
- silylanizing
- silylating agent
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
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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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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J13/00—Colloid chemistry, e.g. the production of colloidal materials or their solutions, not otherwise provided for; Making microcapsules or microballoons
- B01J13/0091—Preparation of aerogels, e.g. xerogels
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Abstract
The invention relates to a method for producing organically modified aerogels with permanently hydrophobic surface groups, wherein a) a lyogel is provided; b) the lyogel provided in step (a) is wahed with an organic solvant; c) the surface of the gel obtained in step (b) is silylated; and d) the silylated surface gel obtained in step (c) is dried. The invention is characterized in that a disiloxane of the formula (I) R3Si-O-SiR3 is used as silylating agent in step (c), wherein the radicals R mean individually, being the same or different, either a hydrogen atom or a non-reactive organic linear, branched, cyclic, saturated or unsaturated, aromatic or heteroaromatic radical.
Description
The present invention relates to a kind of method for preparing aeroge organically-modified, permanently hydrophobic.
Aeroge, particularly porosity be higher than 60% and the density aeroge that is lower than 0.6 gram/cubic centimetre have the low especially capacity of heat transmission, and therefore can be used as heat-insulating material and use, as in EP-A-0 171 722, describing.
In a broad sense, promptly on the meaning of " with the aeroge of air as dispersant ", aeroge is by the suitable preparing gel of drying.On this meaning, term " aeroge " comprises the aeroge of narrow sense, is meant xerogel and epoxy resin.Therefore, surpassing under the temperature of critical-temperature and when the pressure that surpasses critical pressure began to be removed basically, dry gel was sense stricto aeroge when the liquid in the gel.On the contrary, if the liquid of gel under the condition of subcritical, for example is removed by generating liquid-vapour interface mutually, the gel of Sheng Chenging is called as xerogel so.
Employed term aeroge is sensu lato aeroge among the present invention, promptly is as the aeroge on the gel meaning of dispersant with air.
Therefore aeroge can be divided into inorganic and organic aeroge basically.
Inorganic aerogels (S.S.Kistler, nature, 1931,127,741) is just disclosed since 1931.Afterwards, by various raw material preparing aeroge.Therefore for example can prepare SiO by these raw material
2, Al
2O
3, TiO
2, ZrO
2, SnO
2, Li
2O, CeO
2, V
2O
5Aeroge and their mixture (H.D.Gesser, P.C.Goswami, chemistry summary, 1989,89,765 pages etc.).
In the past few years same known organic aerogel.In open source literature, can know organic aerogel (R.W.Pekala based on resorcin/formaldehyde, melamine/formaldehyde or resorcinol/furfural, " material science magazine " (J.Mater.Sci.), 1989,24,3221, US-A-5,508,341, RD388047, WO94/22943 and US-A-5,556,892).Known in addition organic aerogel by PIC (WO95/03358) and polyurethane (US-A-5,484,818) preparation.As US-A-5,508,341 is described, can be prepared as follows aeroge: for example formaldehyde and resorcinol are dissolved in the water with raw material, by appropriate catalyst they are reacted to each other, exchange out the water in the gel pore of generation with the organic solvent that is fit to, subsequently supercritical drying.
Inorganic aerogels can prepare according to diverse ways.
SiO
2Aeroge for example can prepare by orthosilicic acid tetraethyl ester acidic hydrolysis and condensation in ethanol.Therefore produce and a kind ofly under the condition that keeps its structure, can come dry gel by supercritical drying.Preparation method based on this dry technology is for example disclosed among EP-A-0 396 076, WO92/03378 and the WO95/06617.
A kind of subcritical dry SiO is provided
2The method of-gel in the method, made SiO to replace above-mentioned drying means before drying
2-gel and chloride silylating agent reaction.At this moment, SiO
2-gel for example can appropriate organic solvent for example in the ethanol, by water make four alkoxy silicanes, preferably tetraethoxy-silicane (TEOS) acidic hydrolysis prepares.After a kind of appropriate organic solvent is made exchange of solvent, resulting gel in next step with the reaction of chloride silylating agent.According to its reactivity, preferably use methyl chloride monosilane (Me
4-nSiCl
n, n=1-3 wherein) and as silylating agent.Last in air, from organic solvent dry go out so make, its surface is with the group modified SiO of methyl silicane
2-gel.Therefore, can obtain that density is lower than 0.6 gram/cubic centimetre and porosity is higher than 60% aeroge.Described preparation method among the WO94/25149 in detail based on this dry technology.
In addition, as disclosed among the WO92/20623, before drying, above-mentioned gel can react in a pure aqueous solution with four alkoxy silicanes and be aging, to improve the intensity of gel structure.
Yet, in said method, be very expensive as raw-material four alkoxy silicanes.
By using waterglass as preparation SiO
2The raw material of-gel can significantly reduce cost.To this, for example prepare silicic acid by sodium silicate solution by means of ion exchange resin, making this silicic acid polycondensation by adding alkali is SiO
2-gel.After the exchange of water-bearing media and appropriate organic solvent, resulting gel in next step with chloride silylating agent reaction.According to its reactivity, preferably use methyl chloride monosilane (Me
4-nSiCl
n, n=1-3 wherein) and as silylating agent.Last same in air, from organic solvent dry go out so make, its surface is with the group modified SiO of methyl silicane
2-gel.Described preparation method among the DE-A-43 42 548 in detail based on this technology.
When carrying out silylanizing with chloride silylating agent, produce a large amount of hydrochloric acid (HCl) and various relevant therewith accessory substance inevitably, in case of necessity, their require to carry out very expensive, that cost is high, use the appropriate organic solvent cyclic washing so that silylanizing SiO
2-gel-purified.
The purposes of free from chloride silylating agent has been described in DE-C 19502453.To this, at first obtain preparation, the silicic acid salt according to the method described above lyogel, then with free from chloride silylating agent reaction.Therefore, silylating agent methyl isopropyl alkene oxygen base monosilane (Me preferably
4-nSi (OC (CH
3) CH
2)
n, n=1～3 wherein).Subsequently, in air, from organic solvent dry that go out wherein to produce, surface by the methyl silicane base group modified SiO
2-gel.
Though can solve the problem that produces HCl by the no chloromethane silane-based agent of use, yet used no chloromethane silane-based agent is very expensive.
In WO95/06617 and German patent application 195 41 279.6, disclose preparation and had the method for the silicic acid aeroge of hydrophobic surface groups.
In WO95/066 17, following acquisition silicic acid aeroge: water glass solution and a kind of acid are reacted under the pH of 7.5-11 value, the solution washing of the inorganic base by water or dilution, basically remove the ion component in the silicate gel that makes, wherein the pH value of hydrogel remains in the scope of 7.5-11, remove the water that comprises in the hydrogel by alcohol, follow the alcogel that supercritical drying obtains.
In German patent application 195 41 279.6, similar with WO95/06617, preparation silicic acid aeroge is followed subcritical drying.
Yet, in these two kinds of methods, owing to do not use chloride silylating agent just to cause producing the aeroge that has through the hydrophobic surface groups of oxygen bonding.These groups quite are difficult to disconnect under moisture atmosphere again.Therefore, described aeroge only is hydrophobic in short-term.
In addition, for example can use organically-modified in cosmetics and the pharmaceutical field in different technical fields and do not have the gel of subsequent drying as aeroge.
Therefore, the purpose of this invention is to provide a kind of method for preparing the aeroge of permanently hydrophobic, can use cheap silylating agent commonly used in the method, but do not produce defective above-described and well known in the prior art.
The objective of the invention is to have that the method for the aeroge of permanently hydrophobic surface group solves by preparation, in the method,
A) prepare a kind of lyogel,
B) with the lyogel for preparing in the organic solvent washing step a),
C) make the gel surface silylanizing that obtains in the step b) and
D) dry at c) the surperficial silylated gel that obtains in the step, it is characterized in that the disiloxane that uses formula I in step c) is as silylating agent,
R
3Si-O-SiR
3(I) wherein R is separate, and identical or different ground respectively is a hydrogen atom or non-reacted, organic, straight chain, side chain, ring-type, saturated or unsaturated, aromatics or heteroaromatic group, preferably C
1-C
18-alkyl or C
6-C
14-aryl, especially preferably C
1-C
6Alkyl, cyclohexyl or phenyl, particularly methyl or ethyl.
In the present invention, lyogel is the gel that is dispersed at least a solvent.This solvent also can be a water.The water content total is 50 weight % at least in solvent, so also can be called hydrogel.
The structure of lyogel can exist in any organic and/or inorganic base composition.This area professional all systems known in the prior art all can be used as organic base composition.Be preferably based on the silicon of oxidation-, tin-, aluminium-, gallium-, indium-, titanium-and/or the inorganic base composition of zirconium compounds, special preferably those silicon based on oxidation-, aluminium-, titanium-and/or the inorganic base composition of zirconium compounds.More preferably contain a part of zirconium-, aluminium-, titanium-, vanadium-and/or the hydrogel of the silicates of iron compound, particularly pure silicates hydrogel.Under the situation of organic and/or inorganic base composition, various component needs not to be homodisperse and/or forms continuous structure.Single component can partially or even wholly examine with field trash, monocrystalline and/or the form of precipitation exists in this structure.
Compare with chloride silylating agent well known in the prior art, the advantage of the disiloxane that the present invention uses is not produce chloride accessory substance.Indissolubility owing to it is easy to isolate from containing aqueous phase in addition, to reclaim superfluous reagent.Therefore minimum by using excessive concentrate that the silylated time is reduced to.
Lyogel in the step a) can prepare according to all known methods of professional.
Describe the preferred embodiment of the lyogel of preparation silicates below in detail, yet be not limitation ot it.
In preferred embodiments, obtain the lyogel of silicate in step a), this silicate liquid gel obtains by water hydrolysis in organic solvent and condensated silanes oxide.Used silane oxide is four alkoxy silicanes, preferably tetraethoxy-silicane or tetramethoxy-silicane.Here organic solvent is preferably pure, special preferred alcohol or methyl alcohol, the water of 20 volume % more than can being added in them.In organic solvent when water hydrolysis and condensated silanes oxide, can add acid and/or alkali as catalyst with a step or two steps.
Lyogel in the step a) can additionally comprise zirconium compounds, aluminium compound, tin compound and/or the titanium compound that can be used for condensation.
In addition, before the preparation gel and/or during, in colloidal sol, add opacifier as additive, particularly, add the IR opacifier, for example carbon black, titanium dioxide, iron oxide and/or zirconium dioxide in order to reduce the influence of radiation to thermal conductivity.
In addition, can in colloidal sol, add fiber to improve mechanical stability.Fibrous material can be an inorfil, as glass fibre or mineral fibres, and organic fiber, as polyester fiber, aramid fibre, nylon fiber or come from fibre of plant, and their mixture.Also can apply these fibers, for example use metal, as aluminium, the metallized polyimide ester fiber.
Usually, under the temperature of the freezing point to 70 of solution ℃, prepare lyogel.If desired, can carry out molding procedure simultaneously therebetween, for example spray shaping, extruding or one-tenth drip.
In addition, the lyogel of acquisition can further wear out.This process is carried out between the boiling point of organic solvent at 20 ℃ usually.If desired equally can be under higher temperature wear out adding to depress.Aging temperature generally altogether is 48 hours at the most, preferably at the most 24 hours.
In second embodiment preferred, in step a), obtain the hydrogel of silicic acid salt, this hydrogel is prepared as follows: by help downward modulation water saving glass pH value of aqueous solution≤3 of acid-exchange resin, mineral acid or hydrochloric acid solution, making consequent silicic acid polycondensation by adding alkali is SiO
2-gel if use mineral acid or hydrochloric acid solution, washes gel with water to essentially no electrolyte.Can in a step or multistep are rapid, carry out polycondensation, to obtain SiO
2-gel.
Preferred water glass is waterglass sodium and/or waterglass potassium.Ion exchange resin is acidic resins preferably, and wherein particularly suitable is those resins that contain sulfonic acid group.If the use mineral acid, particularly suitable is hydrochloric acid and sulfuric acid.If the use hydrochloric acid solution, particularly suitable is aluminium salt, particularly aluminum sulfate and/or aluminium chloride.Normally used alkali is NH
4OH, NaOH, KOH, Al (OH)
3And/or colloid silicic acid.
Preferably the hydrogel by the preparation of the initial compounds of above-mentioned silicates can additionally comprise zirconium compounds, aluminium compound, tin compound and/or the titanium compound that can be used for condensation.
In addition, before the preparation gel and/or during, in colloidal sol, add opacifier as additive, particularly in order to reduce the influence of radiation, add IR opacifier for example carbon black, titanium dioxide, iron oxide and/or zirconium dioxide to thermal conductivity.
In addition, can in colloidal sol, add fiber to improve mechanical stability.Fibrous material can be an inorfil, as glass fibre or mineral fibres, and organic fiber, as polyester fiber, aramid fibre, nylon fiber or come from fibre of plant, and their mixture.Also can apply these fibers, for example with metal such as aluminium these fibers that metallize.
Usually, under the temperature of the freezing point to 70 of solution ℃, prepare hydrogel.If desired, can carry out molding procedure simultaneously, for example spray shaping, extruding or one-tenth drip.
In addition, the hydrogel of acquisition can further wear out.This process can be carried out before or after above-mentioned possible water washing, wherein water with gel detergent to essentially no electrolyte.
Aging under 20～100 ℃, preferred 40～100 ℃ and preferred especially 80～100 ℃, carry out usually, and be 4～11, preferred 5～9, preferred especially 5～8 until the pH value.For this reason, usually the time adds up to 48 hours at the most, and preferably at the most 24 hours, particularly at the most 3 hours.
In the 3rd embodiment preferred, the hydrogel of the silicates in the step a) is prepared as follows: under the help of at least a organic and/or inorganic acid, obtain SiO by sodium silicate solution through the intermediate steps of silica sol
2-gel.
Water glass solution normally contains 6 to 25 weight % (with SiO
2The content meter) waterglass sodium and/or the solution of waterglass potassium.The preferably water glass solution of 10 to 25 weight %, the particularly water glass solution of 10 to 18 weight %.
In addition, water glass solution comprises with SiO
2Count 90 weight %, that can be used for condensation at the most zirconium compounds, aluminium compound, tin compound and/or titanium compound.
Common employed acid is the acid of 1 to 50 weight %, preferably the acid of 1 to 10 weight %.Preferred acid is sulfuric acid, phosphoric acid, hydrofluoric acid, oxalic acid and/or hydrochloric acid.Preferred especially hydrochloric acid.Can use these sour mixtures equally.
Except that the mixture of original water glass solution and acid, before original mixture, can in water glass solution, add part acid and/or in acid, add part waterglass.By this method, the ratio of water glass solution/acid can change in the scope of non-constant width in the feed stream.
Preferably, these two kinds of solution obtain the SiO of 5 to 12 weight % after mixing
2-gel.The special preferably SiO of 6 to 9 weight %
2-gel.
In order to guarantee that water glass solution and acid mix as well as possiblely fully, at SiO
2Before-gel formed, the temperature that preferably makes these two kinds of solution was 0 to 30 ℃ independently of each other, especially preferably 5 to 25 ℃, is more preferably 10 to 20 ℃.
The rapid mixing of these two kinds of solution is carried out in the known equipment of professional, for example carries out in stirred tank, mixing nozzle and the static mixer.Preferred semicontinuous or continuation method, for example mixing nozzle.
In case of necessity, in preparation, can carry out a kind of forming step, drip as spray shaping, extruding or one-tenth.
In addition, the hydrogel of acquisition can further wear out.Aging usually at 20～100 ℃, carry out under preferred 40～100 ℃ and preferred especially 80～100 ℃, and the pH value is 2.5～11 preferred 5～8.Time for this reason adds up to 12 hours at the most usually, and preferably at the most 2 hours, particularly at the most 30 minutes.
The gel that makes preferably washes with water, especially preferably is washed till the essentially no electrolyte of employed washings.If aging gel, so can be before aging, between or wash afterwards, in this case, preferably between aging or wash afterwards.Wherein water with gel detergent to essentially no electrolyte.Can replace a part of water with organic solvent in order to wash.Yet the content of water is should be so high, comes out to such an extent as to the salt in the hydrogel hole is uncrystallizable.
In order to remove sodium ion and/or potassium ion as much as possible, before washing with water, between and/or also can use inorganic acid washings gel afterwards.Preferred inorganic acid is the inorganic acid of preferably mentioning in the hydrogel preparation too.
In addition, can in waterglass, acid and/or colloidal sol, add opacifier,, add IR opacifier for example carbon black, titanium dioxide, iron oxide and/or zirconium dioxide particularly in order to reduce the influence of radiation to thermal conductivity as additive.
In addition, can in colloidal sol, add fiber to improve mechanical stability.Fibrous material can be an inorfil, as glass fibre or mineral fibres, and organic fiber, as polyester fiber, aramid fibre, nylon fiber or come from fibre of plant, and their mixture.Also can apply these fibers, for example use these fibers of metal such as aluminum metallization.
In step b), preferred≤2 weight % preferably with the gel that obtains in the organic solvent washing step a) until the water content≤5 weight % of gel, especially preferably≤1 weight %.Organic solvent is aliphatic alcohol class, ethers, ester class or ketone and aliphatic series or aromatic hydrocarbons normally.Preferred solvent is methyl alcohol, ethanol, acetone, oxolane, ethyl acetate, diox, pentane, n-hexane, normal heptane and toluene.Preferred especially acetone, oxolane, pentane and normal heptane are as solvent.Can use the mixture of above-mentioned solvent equally.In addition, can at first use with the miscible solvent of water and wash out water, wash out with hydrocarbon then as alcohol, acetone or THF.Hydrocarbon is pentane or normal heptane preferably.
In addition, the lyogel that obtains in the step b) can further wear out.This process is carried out between the boiling point of organic solvent at 20 ℃ usually.If desired, equally can be under higher temperature, wear out adding to depress.Ageing time is general to amount to 48 hours at the most, preferably at the most 24 hours.After this ageing process, if desired, and then carry out exchange of solvent, wherein use identical solvent or another kind of solvent.The aging step that should add if desired, can repeat repeatedly.
In step c) solvent-laden gel with as the reaction of the formula I disiloxane of silylating agent,
R
3Si-O-SiR
3(I) wherein radicals R is separate, and identical or different ground respectively is a hydrogen atom or non-reacted, organic, straight chain, side chain, ring-type, saturated or unsaturated, aromatics or heteroaromatic group, preferably C
1-C
18-alkyl or C
6-C
14-aryl, especially preferably C
1-C
6Alkyl, cyclohexyl or phenyl, particularly methyl or ethyl.
The solvent-laden gel and the disiloxane of symmetry are reacted, and wherein Dui Cheng disiloxane is meant that two Si-atoms respectively have the disiloxane of identical radicals R.
Especially preferably use the identical disiloxane of all radicals R, especially preferably use HMDO.
This reaction is carried out to the temperature between the silylating agent boiling point at 20 ℃ usually, if desired, carries out in solvent.Preferred solvent is the preferred solvent of describing in step b).Preferred especially acetone, oxolane, pentane and normal heptane.If in solvent, carry out silylanizing, to solvent boiling point, carry out silylanizing at 20 ℃ so usually.
In preferred embodiments, catalyst for example acid or alkali in the presence of carry out silylanizing.Preferred use acid is as catalyst.Particularly preferred acid is hydrochloric acid, sulfuric acid, acetate and/or phosphoric acid.
In another embodiment preferred, in the presence of the silylating agent of catalytic amount, carry out silylation reactive, this silylating agent is made up of acid in the presence of water.Chloromethane silane preferably, preferred especially chlorotrimethylsilane (TMCS).In addition, can use the mixture of acid or alkali and TMCS.
Before step d), preferably use proton or aprotic solvent to wash silylated gel, until removing unreacted silylating agent (residual content≤1 weight %) basically.Suitable solvent is aliphatic alcohol, ether, ester or ketone and aliphatic series or aromatic hydrocarbon normally.Preferred solvent is the solvent of mentioning in step b).Similarly, also be preferred here solvent as the solvent of preferably mentioning.
In step d), silylanizing and, if desired, the gel that has washed subsequently is dry under the undercritical conditions, preferably at-30 ℃ to 200 ℃, under preferred especially 0 to the 100 ℃ temperature and at 0.001 to 20 crust, preferred 0.01 to 5 clings to, under the pressure of preferred especially 0.1 to 2 crust, for example by radiant type drying, convection type drying and/or contact drying.Drying lasts till that always the residual solvent levels of gel is less than 0.1 weight % usually.The aeroge that obtains in dry run is a permanently hydrophobic.
The gel that obtains in step c) equally can be dry under super critical condition.Depend on used solvent, it requires baking temperature to be higher than 200 ℃ and/or pressure to be higher than 20 crust.This point undoubtedly is possible, but this means that also high cost can not bring any substantive advantage.
In another embodiment, decide, before the silylanizing of step c), also can make gel carry out structure and strengthen on using.For example by the gel that makes and original acid alkyl ester and/or-the aryl ester solution reaction or with the silicate aqueous solution reaction, described original acid alkyl ester has the condensation ability, its chemical formula is R
1 4-nSi (OR
2)
n, wherein n=2-4 and R
1And R
2Be the C of hydrogen atom, straight or branched independently of each other
1-C
6-alkyl, cyclohexyl or phenyl.
In another embodiment, can according to the known technology of professional for example grinding in step a) the moulding polycondensation and/or each operation subsequently after smash gel to pieces.
Aeroge according to method preparation of the present invention uses as heat-insulating material especially.
Describe method of the present invention in detail by means of embodiment below, but be not limitation of the present invention.
Embodiment 1
Make 2 premium on currency glass sodium solution (SiO
2Content is 6 weight % and Na
2O: SiO
2Ratio=1: 3.3) by protective-cover type glass column (long 100cm, diameter 8cm), wherein this glass column filling (about 70ml/ minute) has 4 liters of acid-exchange resins (styrene diethylene benzene copoly mer with sulfonic acid group is with trade name
@Duolite C20d is commercially available).This glass column is worked under about 7 ℃ temperature.The pH value of the silicate solution that flow out the column bottom is 2.3.For polycondensation, use 1 mole NaOH solution that the pH value of this solution is adjusted to 4.7.Then, under 85 ℃, the gel that is produced was worn out 3 hours, follow acetone-exchanged water with 3 liters.Then at room temperature make the gel that contains acetone carry out silylanizing 5 hours (every gram wet gel with the HMDO of 2.5 weight %) with HMDO.After 3 liters of acetone detergent gel, in air drying gel (40 ℃ following 3 hours, 50 ℃ of following 2 hours and 150 ℃ are following 12 hours then).The density of the transparency aerogel of Huo Deing is 0.15 gram/cubic centimetre like this, and thermal conductivity is 16mW/mk, and the BET specific area is 600 meters squared per gram, and is permanently hydrophobic.
Embodiment 2
Be cooled at 424 grams and dripped 712 grams in 10 ℃ the 7.5 weight %HCl solution and be cooled to 10 ℃ waterglass sodium solution (SiO
2Content is 13 weight % and Na
2O: SiO
2Ratio=1: 3.3).Regulating the pH value is 4.7.The hydrogel that back in several seconds is produced 85 ℃ aging 3 hours down, use 3 liters of hot washes subsequently, and with 3 liters acetone-exchanged water.The gel silylanizing of at room temperature using HMDO (every gram wet gel with the HMDO of 2.5 weight %) to make then to contain acetone 5 hours.After 3 liters of acetone detergent gel, in air drying gel (40 ℃ following 3 hours, 50 ℃ of following 2 hours and 150 ℃ are following 12 hours then).
The density of the aeroge of Huo Deing is 0.15 gram/cubic centimetre like this, and thermal conductivity is 17mW/mk, and the BET specific area is 580 meters squared per gram, and is permanently hydrophobic.
Embodiment 3
With embodiment 2 preparation hydrogels.At 85 ℃ of following aging hydrogels 1 hour, use 3 liters of hot washes subsequently, and with 3 liters acetone-exchanged water.Then, at room temperature, in the presence of the trim,ethylchlorosilane of 0.1 weight % (every gram wet gel with the chlorotrimethylsilane of 0.1 weight %), make the gel silylanizing 5 hours that contains acetone with HMDO (every gram wet gel with the HMDO of 2.5 weight %).After 3 liters of acetone detergent gel, in air drying gel (40 ℃ following 3 hours, 50 ℃ of following 2 hours and 150 ℃ are following 12 hours then).
The density of the aeroge of Huo Deing is 0.14 gram/cubic centimetre like this, and thermal conductivity is 16mW/mk, and the BET specific area is 590 meters squared per gram, and is permanently hydrophobic.
Embodiment 4
With embodiment 2 preparation hydrogels.At 85 ℃ of following aging hydrogels 1 hour, use 3 liters of hot washes subsequently, and with 3 liters acetone-exchanged water.Then, at room temperature, in the presence of the 1N aqueous hydrochloric acid of 0.1 weight % (every gram wet gel with the 1N aqueous hydrochloric acid of 0.1 weight %), make the gel silylanizing 5 hours that contains acetone with HMDO (every gram wet gel with the HMDO of 2.5 weight %).After 3 liters of acetone detergent gel, in air drying gel (40 ℃ following 3 hours, 50 ℃ of following 2 hours and 150 ℃ are following 12 hours then).
The density of the aeroge of Huo Deing is 0.14 gram/cubic centimetre like this, and thermal conductivity is 16mW/mk, and the BET specific area is 570 meters squared per gram, and is permanently hydrophobic.
Measure thermal conductivity (referring to as O.Nielssion, G.Ruschenpohler, J.Gross, J.Fricke, " high temperature-high pressure ", the 21st phase, 267-274 (1989)) with heat wire method.
Claims (32)
1, preparation has the method for the organically-modified aeroge of permanently hydrophobic surface group, in the method,
A) preparation lyogel,
B) with the gel for preparing in the organic solvent washing step a),
C) make the gel surface silylanizing that obtains in the step b) and
D) dry at c) the surperficial silylated gel that obtains in the step, it is characterized in that the disiloxane that uses formula I in step c) is as silylating agent,
R
3Si-O-SiR
3(I) wherein R independently of each other, identical or different ground respectively is a hydrogen atom or non-reacted, organic, straight chain, side chain, ring-type, saturated or unsaturated, aromatics or heteroaromatic group.
2, according to the method for claim 1, it is characterized in that the lyogel of preparation silicates in step a).
3, according to the method for claim 2, it is characterized in that, the lyogel of preparation silicates in step a), this silicates lyogel obtains by water hydrolysis in organic solvent and condensated silanes oxide.
4, according to the method for claim 2, it is characterized in that, the lyogel of preparation silicates in the step a), this lyogel is prepared as follows: in help downward modulation water saving glass pH value of aqueous solution≤3 of acid-exchange resin, mineral acid or hydrochloric acid solution, making the silicic acid polycondensation that is produced by adding alkali is SiO
2-gel, and when using mineral acid or hydrochloric acid solution, make to wash gel with water to essentially no electrolyte.
According to the method for claim 2, it is characterized in that 5, the hydrogel of the silicates in the step a) is prepared as follows: under the help of at least a organic and/or inorganic acid, by sodium silicate solution through the intermediate steps of silica sol and obtain SiO
2-gel.
6, according to each method in the claim 1 to 5, it is characterized in that, before the preparing gel and/or between add opacifier.
7, according to each method in the claim 1 to 5, it is characterized in that, before the preparation gel and/or the phase with adding fiber.
8, according to the method for claim 6, it is characterized in that, the preparation gel before and/or during add fiber.
9, according to each method in the claim 1 to 5, it is characterized in that aging this gel before in step b), the lyogel that obtains in the step a) being washed.
10, according to the method for claim 6, it is characterized in that aging this gel before in step b), the lyogel that obtains in the step a) being washed.
According to each method in the claim 1 to 5, it is characterized in that 11, detergent gel so for a long time in step b) is till the water content≤5 weight % of gel.
According to the method for claim 6, it is characterized in that 12, detergent gel so for a long time in step b) is till the water content≤5 weight % of gel.
According to each method in the claim 1 to 5, it is characterized in that 13, the organic solvent in the step b) is aliphatic alcohol class, ethers, ester class or ketone and aliphatic series or aromatic hydrocarbon based.
According to the method for claim 6, it is characterized in that 14, the organic solvent in the step b) is aliphatic alcohol class, ethers, ester class or ketone and aliphatic series or aromatic hydrocarbon based.
15, according to each method in the claim 1 to 5, it is characterized in that, in step c), use the disiloxane of symmetry as silylating agent.
16, according to the method for claim 6, it is characterized in that, in step c), use the disiloxane of symmetry as silylating agent.
17, according to each method in the claim 1 to 5, it is characterized in that, in step c), use disiloxane that wherein all radicals R are all identical as silylating agent.
According to the method for claim 6, it is characterized in that 18, the use disiloxane that wherein all radicals R are all identical is as silylating agent in step c).
19, according to each method in the claim 1 to 5, it is characterized in that, in step c), use HMDO as silylating agent.
20, according to the method for claim 6, it is characterized in that, in step c), use HMDO as silylating agent.
21, according to each method in the claim 1 to 5, it is characterized in that, in solvent, carry out silylation reactive.
22, according to the method for claim 6, it is characterized in that, in solvent, carry out silylation reactive.
23, according to each method in the claim 1 to 5, it is characterized in that, in the presence of catalyst, carry out silylation reactive.
24, according to the method for claim 6, it is characterized in that, in the presence of catalyst, carry out silylation reactive.
25, according to each method in the claim 1 to 5, it is characterized in that, in the presence of the chlorotrimethylsilane of catalytic amount, carry out silylation reactive.
26, according to the method for claim 6, it is characterized in that, in the presence of the chlorotrimethylsilane of catalytic amount, carry out silylation reactive.
27, according to each method in the claim 1 to 5, it is characterized in that, before step d), use proton or aprotic solvent wash its surface silylanizing gel.
28, according to the method for claim 6, it is characterized in that, before step d), use proton or aprotic solvent wash its surface silylanizing gel.
29, according to each method in the claim 1 to 5, it is characterized in that, in step d), under undercritical conditions desiccated surface silylanizing gel.
30, according to the method for claim 6, it is characterized in that, in step d), under undercritical conditions desiccated surface silylanizing gel.
31, according to each method in the claim 1 to 5, it is characterized in that, before silylanizing, make the gel that obtains in the step b) and ortho-silicate reaction or with the silicate aqueous solution reaction, described ortho-silicate has the condensation ability, its chemical formula is R
1 4-nSi (OR
2)
n, wherein n=2-4 and R
1And R
2Be the C of hydrogen atom, straight or branched independently of each other
1-C
6-alkyl, cyclohexyl or phenyl.
32, according to the method for claim 6, it is characterized in that, before silylanizing, make the reaction of the gel that obtains in the step b) and ortho-silicate or with the silicate aqueous solution reaction, described ortho-silicate has the condensation ability, its chemical formula is R
1 4-nSi (OR
2)
n, wherein n=2-4 and R
1And R
2Be the C of hydrogen atom, straight or branched independently of each other
1-C
6-alkyl, cyclohexyl or phenyl.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| DE19648797.8 | 1996-11-26 | ||
| DE19648797A DE19648797A1 (en) | 1996-11-26 | 1996-11-26 | Process for the production of organically modified, permanently hydrophobic aerogels |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN1241953A CN1241953A (en) | 2000-01-19 |
| CN1101725C true CN1101725C (en) | 2003-02-19 |
Family
ID=7812715
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN97181109A Expired - Fee Related CN1101725C (en) | 1996-11-26 | 1997-11-26 | Method for producing organically modified, permanently hydrophobic aerogels |
Country Status (7)
| Country | Link |
|---|---|
| EP (1) | EP0946277A2 (en) |
| JP (1) | JP2001504757A (en) |
| KR (1) | KR20000057273A (en) |
| CN (1) | CN1101725C (en) |
| CA (1) | CA2274911A1 (en) |
| DE (1) | DE19648797A1 (en) |
| WO (1) | WO1998023367A2 (en) |
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| DE112017001567T5 (en) | 2016-09-14 | 2018-12-20 | Nano Technology Co., Ltd. | A rapid production process for an airgel with a microemulsion precursor |
| WO2021069783A1 (en) | 2019-10-07 | 2021-04-15 | Consejo Superior De Investigaciones Científicas | Method for preparing hydrophobic aerogels |
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| CN1317188C (en) * | 2005-07-15 | 2007-05-23 | 清华大学 | Process for preparing hydrophobic silicon dioxide aerogel using rice husk ash as raw material |
| KR100785521B1 (en) * | 2006-07-03 | 2007-12-13 | 한국생산기술연구원 | Method for preparing surface-modified aerogel and surface-modified aerogel therefrom |
| KR101091860B1 (en) * | 2006-10-10 | 2011-12-12 | 한국생산기술연구원 | Method for Preparing Permanently Hydrophobic Aerogel And Permanently Hydrophobic Aerogel Prepared by Using the Method |
| CN100463852C (en) * | 2006-12-19 | 2009-02-25 | 中国人民解放军国防科学技术大学 | High temperature and high pressure prepn process of SiO2 aerogel |
| KR101434273B1 (en) * | 2007-03-15 | 2014-08-27 | 알이엠텍 주식회사 | Method for Preparing Surface-Modified Aerogel |
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| KR100867466B1 (en) * | 2007-04-18 | 2008-11-10 | 한국생산기술연구원 | Method for Preparing Permanently Hydrophobic Aerogel Powder Having Increased Particle Size and Density And Aerogel Powder Therefrom |
| KR100896790B1 (en) * | 2007-07-16 | 2009-05-11 | 한국과학기술연구원 | Fabrication method for silica aerogel and silica aerogel fabricated therefrom |
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| CN102198943B (en) * | 2011-04-21 | 2013-03-13 | 江苏大学 | Method for preparing silicon-based aerogel with different contact angles by drying with low cost under normal pressure |
| FR2981341B1 (en) * | 2011-10-14 | 2018-02-16 | Enersens | PROCESS FOR MANUFACTURING XEROGELS |
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| DE102015207939A1 (en) * | 2015-04-29 | 2016-11-03 | Wacker Chemie Ag | Process for the preparation of organically modified aerogels |
| CN107709236A (en) * | 2015-07-01 | 2018-02-16 | 松下知识产权经营株式会社 | Aeroge, the manufacture method using the component of the aeroge and the aeroge |
| KR20180114017A (en) * | 2016-02-15 | 2018-10-17 | 파나소닉 아이피 매니지먼트 가부시키가이샤 | Process for hydrophobic treatment and method for manufacturing sheet-like member using the same |
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| EP3571173A1 (en) * | 2017-01-18 | 2019-11-27 | Evonik Degussa GmbH | Granular thermal insulation material and method for producing the same |
| CN107384067A (en) * | 2017-06-03 | 2017-11-24 | 安徽绿环泵业有限公司 | A kind of preparation method of pump heat resisting motor fan housing |
| CN113402902A (en) * | 2021-06-21 | 2021-09-17 | 江苏脒诺甫纳米材料有限公司 | Production process of silicon-based sunscreen heat-insulation powder |
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| WO1994026406A1 (en) * | 1993-05-18 | 1994-11-24 | Hoechst Aktiengesellschaft | Method for the sub-critical drying of aerogels |
| WO1996022942A1 (en) * | 1995-01-27 | 1996-08-01 | Hoechst Aktiengesellschaft | Process for the production of modified aerogels and use thereof |
-
1996
- 1996-11-26 DE DE19648797A patent/DE19648797A1/en not_active Ceased
-
1997
- 1997-11-26 WO PCT/EP1997/006596 patent/WO1998023367A2/en not_active Application Discontinuation
- 1997-11-26 CN CN97181109A patent/CN1101725C/en not_active Expired - Fee Related
- 1997-11-26 JP JP52427998A patent/JP2001504757A/en not_active Ceased
- 1997-11-26 KR KR1019990704666A patent/KR20000057273A/en not_active Application Discontinuation
- 1997-11-26 EP EP97952807A patent/EP0946277A2/en not_active Withdrawn
- 1997-11-26 CA CA002274911A patent/CA2274911A1/en not_active Abandoned
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1994026406A1 (en) * | 1993-05-18 | 1994-11-24 | Hoechst Aktiengesellschaft | Method for the sub-critical drying of aerogels |
| WO1996022942A1 (en) * | 1995-01-27 | 1996-08-01 | Hoechst Aktiengesellschaft | Process for the production of modified aerogels and use thereof |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE112017001567T5 (en) | 2016-09-14 | 2018-12-20 | Nano Technology Co., Ltd. | A rapid production process for an airgel with a microemulsion precursor |
| WO2021069783A1 (en) | 2019-10-07 | 2021-04-15 | Consejo Superior De Investigaciones Científicas | Method for preparing hydrophobic aerogels |
Also Published As
| Publication number | Publication date |
|---|---|
| DE19648797A1 (en) | 1998-05-28 |
| WO1998023367A2 (en) | 1998-06-04 |
| JP2001504757A (en) | 2001-04-10 |
| EP0946277A2 (en) | 1999-10-06 |
| CN1241953A (en) | 2000-01-19 |
| CA2274911A1 (en) | 1998-06-04 |
| KR20000057273A (en) | 2000-09-15 |
| WO1998023367A3 (en) | 1998-07-16 |
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