US20180072031A1 - Method for producing porous silicone sheet, frozen body, and porous silicone sheet rolled-body - Google Patents

Method for producing porous silicone sheet, frozen body, and porous silicone sheet rolled-body Download PDF

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US20180072031A1
US20180072031A1 US15/564,532 US201615564532A US2018072031A1 US 20180072031 A1 US20180072031 A1 US 20180072031A1 US 201615564532 A US201615564532 A US 201615564532A US 2018072031 A1 US2018072031 A1 US 2018072031A1
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sheet
porous silicone
silicone sheet
frozen
porous
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Naoyuki Matsuo
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Nitto Denko Corp
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B27/00—Layered products comprising a layer of synthetic resin
    • B32B27/28—Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42
    • B32B27/283—Layered products comprising a layer of synthetic resin comprising synthetic resins not wholly covered by any one of the sub-groups B32B27/30 - B32B27/42 comprising polysiloxanes
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D7/00—Producing flat articles, e.g. films or sheets
    • B29D7/01—Films or sheets
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
    • C08G77/04—Polysiloxanes
    • C08G77/06—Preparatory processes
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
    • C08G77/00—Macromolecular compounds obtained by reactions forming a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon in the main chain of the macromolecule
    • C08G77/04—Polysiloxanes
    • C08G77/14—Polysiloxanes containing silicon bound to oxygen-containing groups
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
    • C08J5/18—Manufacture of films or sheets
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/24—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by surface fusion and bonding of particles to form voids, e.g. sintering
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/28—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum
    • C08J9/286—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a liquid phase from a macromolecular composition or article, e.g. drying of coagulum the liquid phase being a solvent for the monomers but not for the resulting macromolecular composition, i.e. macroporous or macroreticular polymers
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
    • C08J9/36—After-treatment
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2201/00—Foams characterised by the foaming process
    • C08J2201/04—Foams characterised by the foaming process characterised by the elimination of a liquid or solid component, e.g. precipitation, leaching out, evaporation
    • C08J2201/05—Elimination by evaporation or heat degradation of a liquid phase
    • C08J2201/0504—Elimination by evaporation or heat degradation of a liquid phase the liquid phase being aqueous
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2201/00—Foams characterised by the foaming process
    • C08J2201/04—Foams characterised by the foaming process characterised by the elimination of a liquid or solid component, e.g. precipitation, leaching out, evaporation
    • C08J2201/054—Precipitating the polymer by adding a non-solvent or a different solvent
    • C08J2201/0545—Precipitating the polymer by adding a non-solvent or a different solvent from an aqueous solvent-based polymer composition
    • C08J2201/0546—Precipitating the polymer by adding a non-solvent or a different solvent from an aqueous solvent-based polymer composition the non-solvent being organic
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2205/00—Foams characterised by their properties
    • C08J2205/02—Foams characterised by their properties the finished foam itself being a gel or a gel being temporarily formed when processing the foamable composition
    • C08J2205/028—Xerogel, i.e. an air dried gel
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2205/00—Foams characterised by their properties
    • C08J2205/04—Foams characterised by their properties characterised by the foam pores
    • C08J2205/05—Open cells, i.e. more than 50% of the pores are open
    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J2383/00—Characterised by the use of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen, or carbon only; Derivatives of such polymers
    • C08J2383/04—Polysiloxanes

Definitions

  • the present invention relates to a method for producing a porous silicone sheet, frozen body, and a porous silicone sheet rolled-body.
  • a sol-gel reaction involving phase separation has conventionally been known as a method for obtaining a monolithic porous material having continuous though-holes with controlled sizes in an organic-inorganic hybrid system using an oxide such as silica or titania, and a trifunctional alkoxysilane as starting materials (see Patent Documents 1 and 2).
  • an oxide such as silica or titania
  • a trifunctional alkoxysilane as starting materials
  • Patent Document 3 describes the preparation of a silicone monolithic body of an aerogel or xerogel having continuously penetrating flow channels and a silicone skeleton capable of dissolving chemical species by using both a bifunctional group-containing alkoxysilane and a trifunctional group-containing alkoxysilane or trifunctional or higher group-containing alkoxysilane as staring materials, copolymerizing those silanes by a sol-gel reaction, forming a network by Si—O bonds and simultaneously performing phase separation.
  • Patent Document 3 further describes that the silicone monolithic body has both high flexibility and high porosity.
  • Patent Document 1 Japanese Patent No. 2893104
  • Patent Document 2 Japanese Patent No. 3397255
  • Patent Document 3 JP-A-2014-61457
  • Patent Document 3 As a result of investigations on the silicone monolithic body (hereinafter referred to as a porous silicone body) described in Patent Document 3, the present inventors have obtained the following finding.
  • impurities such as unreacted precursors, a catalyst and a surfactant are removed by applying cleaning to a bulk wet gel (swollen gel) prepared in a closed vessel.
  • a bulk wet gel swelling gel
  • the present inventors it became clear that even though cleaning is applied to a bulk wet gel, particularly a large-sized bulk wet gel, impurities remained inside pores of the bulk cannot be sufficiently removed, and there are problems of ununiformity of density distribution after drying and inhibition of water repellent function of a skeleton itself.
  • the problem became clear that when a bulk wet gel, particularly a large-sized bulk wet gel, is taken out of the closed vessel, the wet gel may fracture by its weight.
  • the present invention has an object to produce a porous silicone body from which impurities have been sufficiently removed. Furthermore, the present invention has an object to effectively prevent occurrence of fracture of the wet gel in the production process.
  • the present inventors have found that the above problems can be solved by forming a frozen body obtained by freezing a wet gel into a sheet, and have reached to complete the present invention.
  • the present invention provides a method for producing a porous silicone sheet comprising a freezing step of freezing a wet gel of a porous silicone body having communicating pores and a three-dimensional network silicone skeleton which forms the pores and which is formed by a copolymerization of a bifunctional alkoxysilane and a trifunctional alkoxysilane, to obtain a frozen body, a sheet forming step of forming the frozen body into a sheet to obtain a porous silicone sheet, and a cleaning step of cleaning the porous silicone sheet.
  • the sheet forming step may comprise subjecting the frozen body to a skiving processing.
  • the method for producing a porous silicone sheet may further comprise a rolling step of rolling the porous silicone sheet.
  • the present invention further provides a frozen body obtained by freezing a wet gel of a porous silicone body having communicating pores and a three-dimensional network silicone skeleton which forms the pores and which is formed by a copolymerization of a bifunctional alkoxysilane and a trifunctional alkoxysilane.
  • the present invention further provides a porous silicone sheet rolled-body having communicating pores and a three-dimensional network silicone skeleton which forms the pores and which is formed by a copolymerization of a bifunctional alkoxysilane and a trifunctional alkoxysilane.
  • a frozen body obtained by freezing a wet gel is formed into a sheet to obtain a porous silicone sheet.
  • the porous silicone sheet is thinned. Therefore, impurities in the sheet can be satisfactorily removed by cleaning.
  • the wet gel is frozen. Therefore, fracture by its weight of the wet gel is effectively prevented.
  • the frozen body of the frozen wet gel maintains it shape. Therefore, fracture in forming into a sheet is effectively prevented.
  • the porous silicone sheet formed into a sheet is thinned. Therefore, fracture by its weight is effectively prevented even after the frozen state has been dissolved.
  • FIG. 1 is a schematic view showing the state when a frozen body of a wet gel is subjected to skiving processing.
  • the method for producing a porous silicone sheet of the present embodiment comprises a freezing step of freezing a wet gel of a porous silicone body having communicating pores and a three-dimensional network silicone skeleton which forms the pores and which is formed by a copolymerization of a bifunctional alkoxysilane and a trifunctional alkoxysilane, to obtain a frozen body, a sheet forming step of forming the frozen body into a sheet to obtain a porous silicone sheet, and a cleaning step of cleaning the porous silicone sheet.
  • a bifunctional alkoxysilane and a trifunctional alkoxysilane are copolymerized with each other by a sol-gel reaction involving phase separation to obtain a wet gel.
  • a bifunctional alkoxysilane and a trifunctional alkoxysilane are used as precursors, those are networked through Si—O bond by copolymerization by a sol-gel reaction, and simultaneously an acid-base two stage reaction is conducted by an acid catalyst and a base catalyst while controlling phase separation with a surfactant.
  • a wet gel of a porous silicone body having communicating pores and a three-dimensional network silicone skeleton that forms the pores is formed.
  • the porous silicone body has communicating pores and a three-dimensional network silicone skeleton that forms the pores.
  • the porous silicone body in the present embodiment has a monolithic structure.
  • the “monolithic structure” used herein is a bicontinuous structure integrally constituted of a continuous three-dimensional network skeleton and communicating pores.
  • the surface of the three-dimensional network silicone skeleton of the porous silicone body comprises the part forming (demarcating) an external form of the porous silicone body itself and the part forming (demarcating) the communicating pores.
  • the “wet gel” in the present description indicates a state that a liquid such as a reaction liquid after a sol-gel reaction has been adhered to the whole or a part of the surface of the three-dimensional network silicone skeleton of the porous silicone body.
  • a solvent, an acid catalyst, a base catalyst and a surfactant are mixed with each other in an appropriate vessel such as a vessel made of a metal such as stainless steel or a glass vessel.
  • an appropriate vessel such as a vessel made of a metal such as stainless steel or a glass vessel.
  • the solvent that can be used include water, ethanol and methanol.
  • the acid catalyst that can be used include acetic acid, oxalic acid and formic acid.
  • the base catalyst that can be used include urea and ammonia water.
  • the surfactant that can be used include n-hexadecyltrimethyl ammonium chloride (CTAC) and cetyltrimethylammonium bromide (CTAB).
  • acetic acid as an acid catalyst is mixed with water as a solvent in a vessel such as a glass vessel to prepare an acetic acid aqueous solution, and n-hexadecyltrimethylammonium chloride (CTAC) as a surfactant and urea as a base catalyst are added thereto.
  • CTC n-hexadecyltrimethylammonium chloride
  • a bifunctional alkoxysilane and a trifunctional alkoxysilane as precursors are then added to the resulting mixture, followed by stirring, for example, at from 10 to 30° C. for from 0.5 to 2.0 hours, thereby hydrolysis of the precursors proceeds.
  • the solution obtained is placed in a closed state, and heated, for example, at from 50 to 85° C. for from 6 to 48 hours.
  • the base catalyst is hydrolyzed to form basic conditions, and the hydrolyzed precursors are polycondensed by a sol-gel reaction to obtain a wet gel (wet gel).
  • the vessel containing the solution may be placed in the closed state, or the solution may be transferred to a closed vessel other than the vessel.
  • the bifunctional alkoxysilane has four bonding groups bonded to silicon. Of the four bonding groups, two groups are alkoxy groups that participate in polymerization (bonding), and the remaining two groups are modifying groups that do not participate in a reaction.
  • the bifunctional alkoxysilane is represented by the following chemical formula (1).
  • the alkoxy group (—OR 1 ) in the bifunctional alkoxysilane is preferably an alkoxy group having 1 to 5 carbon atoms. From the standpoint of hydrolysis reaction rate, the alkoxy group is preferably methoxy group, ethoxy group or propoxy group, and more preferably methoxy group or ethoxy group. Two alkoxy groups (—OR 1 ) in the bifunctional alkoxysilane may be the same or different.
  • Examples of the modifying group (—R 2 ) in the bifunctional alkoxysilane include a substituted or unsubstituted alkyl group, an aryl group, a vinyl group and a mercaptoalkyl group.
  • the alkyl group in the substituted or unsubstituted alkyl group is preferably an alkyl group having 1 to 5 carbon atoms. Methyl group or ethyl group is preferred, and methyl group is more preferred.
  • Example of the substituent includes a halogen element such as fluorine, chlorine, bromine or iodine.
  • the substituted alkyl group is preferably a fluoroalkyl group.
  • aryl group examples include phenyl group, tolyl group, xylyl group, biphenylyl group and naphthyl group. Phenyl group is preferred.
  • Examples of the mercaptoalkyl group include mercaptomethyl group, mercaptoethyl group and mercaptopropyl group.
  • Mercaptopropyl group is preferred.
  • Two modifying groups (—R 2 ) in the bifunctional alkoxysilane may be the same or different. From the standpoint of imparting functions such as water repellency and heat resistance to the structure to be obtained, at least one of those two modifying groups is preferably selected from the group consisting of methyl group, phenyl group and a fluoroalkyl group.
  • bifunctional alkoxysilane specifically include dimethyl dimethoxysilane, methylphenyl dimethoxysilane, methylvinyl dimethoxysilane, 3-mercaptopropylmethyl dimethoxysilane and 3,3,3-trifluoropropylmethyl dimethoxysilane. From the standpoint of improvement of heat resistance, dimethyl dimethoxysilane and methylphenyl dimethoxysilane are particularly preferred.
  • the bifunctional alkoxysilane may be used in one kind alone or as mixtures of two or more kinds.
  • the trifunctional alkoxysilane has four bonding groups bonded to silicon. Of the four bonding groups, three groups are alkoxy groups that participate in polymerization (bonding), and the remaining one group is a modifying group that does not participate in a reaction.
  • the trifunctional alkoxysilane is represented by the following chemical formula (2).
  • Examples of the alkoxy group (—OR 3 ) in the trifunctional alkoxysilane include the same groups as in the alkoxy group (—OR 1 ) in the bifunctional alkoxysilane.
  • Examples of the modifying group (—R 4 ) in the trifunctional alkoxysilane include the same groups as in the modifying group (—R 2 ) in the bifunctional alkoxysilane.
  • the modifying group in the trifunctional alkoxysilane is preferably methyl group, phenyl group or a fluoroalkyl group, from the standpoint of imparting functions such as water repellency and heat resistance to the structure to be obtained.
  • trifunctional alkoxysilane specifically include methyl trimethoxysilane, vinyl trimethoxysilane and 3-mercaptopropyl trimethoxysilane. Methyl trimethoxysilane is particularly preferred from the standpoint of the improvement of heat resistance.
  • the trifunctional alkoxysilane may be used in one kind alone or as mixtures of two or more kinds.
  • tri- or more polyfunctional alkoxysilanes may be further copolymerized together with the bifunctional alkoxysilane and trifunctional alkoxysilane.
  • the tri- or more polyfunctional alkoxysilanes used herein mean silanes having more than three alkoxy groups participating in polymerization (bonding). Examples of the tri- or more polyfunctional alkoxysilanes include alkoxysilanes having —Si—C—C—Si— structure or —Si— phenyl-Si— structure. The number of bonding groups to Si is 4.
  • alkoxysilanes having —Si—C—C—Si— structure or —Si— phenyl-Si— structure as a crosslinking agent, 6 functional groups can be utilized, and denser silicone network can be formed.
  • Example of the alkoxysilane having —Si—C—C—Si— structure includes 1,2-bis(methyldiethoxysilyl)ethane.
  • Polymerization ratio between the bifunctional alkoxysilane and the trifunctional alkoxysilane can be appropriately selected considering properties and the like of a desired porous silicone body, and is not particularly limited.
  • the polymerization ratio (bifunctional alkoxysilane:trifunctional alkoxysilane) is preferably 2:8 to 6:4, and more preferably 3:7 to 5:5, in volume ratio.
  • the polymerization ratio is 2:8 or more, it is preferred in imparting flexibility to a porous body to be obtained.
  • the polymerization ratio is 6:4 or less, it is preferred in maintaining mechanical strength.
  • the polymerization ratio of the tri- or more polyfunctional alkoxysilanes is not particularly limited.
  • volume ratio to the total of the bifunctional alkoxysilane and trifunctional alkoxysilane total of bifunctional alkoxysilane and trifunctional alkoxysilane: tri- or more polyfunctional alkoxysilanes
  • total of bifunctional alkoxysilane and trifunctional alkoxysilane: tri- or more polyfunctional alkoxysilanes is, for example, 6:4 to 4:6.
  • a freezing step of freezing the wet gel obtained by the preparation step to obtain a frozen body is carried out.
  • the wet gel is frozen to form a frozen body, its shape is maintained, and as a result, the occurrence of fracture by a weight itself can be prevented.
  • the freezing method in freezing the wet gel is not particularly limited so long as it can freeze the wet gel.
  • a method of maintaining a vessel containing the wet gel under the environment that the wet gel freezes (for example, in the case of using water as a solvent, 0° C. or lower) is exemplified.
  • the freezing temperature in freezing the wet gel is not particularly limited so long as it is a temperature that can freeze the frozen gel, and can be appropriately selected depending on the kind of a solvent, and the like.
  • the freezing temperature is set to 0° C. or lower (for example, from ⁇ 50 to 0° C., and preferably from ⁇ 30 to 0° C.).
  • the freezing temperature can be appropriately adjusted by adjusting a pressure in the freezing step.
  • the pressure in the freezing step is not particularly limited, and is, for example, from 0.1 to 2.0 atm.
  • a sheet forming step of forming the wet gel obtained in the freezing step into a sheet to obtain a porous silicone sheet is carried out.
  • the frozen body of the wet gel frozen by the freezing step maintains its shape. Therefore, fracture of the frozen body can be effectively prevented in forming into a sheet.
  • the ambient temperature in forming the frozen body into a sheet is appropriately selected depending on the kind of a solvent used in the preparation step, and the like, and is not particularly limited. It is preferred to maintain the ambient temperature to an extent such that the frozen body does not thaw.
  • the ambient temperature in forming the frozen body into a sheet in the case of using water as a solvent is, for example, from ⁇ 50 to 0° C., and preferably from ⁇ 30 to 0° C.
  • the frozen gel in forming into sheet is required to be in the state of a frozen boy (frozen state). Therefore, the porous silicone sheet after forming into a sheet may be a frozen state and may not be a frozen state. In other words, the porous silicone sheet is thinned after forming into a sheet. Therefore, even after the frozen state has been dissolved, fracture by its weight can be effectively prevented.
  • the porous silicone sheet obtained by this step has a thickness of, for example, from 0.05 to 30 mm, and preferably from 0.5 to 15 mm.
  • the thickness of the porous silicone sheet exceeds 30 mm, there is a case where impurities such as unreacted precursors, a catalyst and a surfactant cannot be satisfactorily removed even by a cleaning step described hereinafter.
  • the thickness of the porous silicone sheet is less than 0.05 mm, there is a case where the sheet fractures in cleaning and sheet conveying steps described hereinafter.
  • the method for forming the frozen body into a sheet is not particularly limited, and examples of the method include a method of slicing the frozen body with various cutting tools such as a cutter or a knife, or appropriate means such as a laser or water jet, and a method of applying skiving processing to the frozen body. Above all, skiving processing is preferred from the standpoint of the possibility of continuous sheet formation.
  • skiving processing in the present embodiment means a so-called rotary cutting (rotary stripping).
  • FIG. 1 is a schematic view showing the state when the state in subjecting a frozen body of a wet gel to skiving process has been seen from a direction of rotation axis of a mandrel 4 .
  • the mandrel 4 (also called a core or a shaft) is inserted in an axis position of a frozen body 2 formed in a cylindrical shape.
  • the mandrel 4 may be inserted in the frozen body 2 after freezing a wet gel to prepare the frozen body 2 , or may be previously inserted in a wet gel before freezing. Alternatively, the mandrel 4 may be previously set to a reaction vessel in the stage before preparing a wet gel.
  • the frozen body 2 when skiving processing is applied to a frozen body by pressing a cutting blade 3 to the surface of the frozen body 2 while rotating the frozen body 2 in one direction as the mandrel 4 inserted in the axis position being a rotation axis, the frozen body 2 is formed into a sheet to form a porous silicone sheet 1 .
  • an angle ⁇ of ⁇ ATB formed by a rotation center A of the frozen body 2 , a contact position T between the cutting blade 3 and the frozen body 2 , and a point B on a blade face of the cutting blade 3 is generally from 20 to 120°, preferably from 70 to 110°, and more preferably from 80 to 110°.
  • the blade face on the cutting blade 3 means a face including a tip position of a blade (the contact position T to the frozen body 2 ) in FIG. 2 , and further including a bisector of an angle in a cross-section of the tip part of a blade.
  • the line speed is preferably from 0.1 to 30 m/min, and more preferably from 1 to 10 m/min.
  • Cutting thickness of the porous silicone sheet 1 is, for example, from 0.05 to 30 mm, preferably from 0.5 to 15 mm, and more preferably from 1 to 10 mm.
  • the long porous silicone sheet 1 continuously formed into a sheet by skiving processing may be directly conveyed using a conveying roller 6 as necessary.
  • a conveying roller 6 since the porous silicone sheet 1 is thinned, tensile strength is low, and there is a case where it is difficult to convey the sheet in the state that tensile stress has been applied thereto. Therefore, when conveying the long porous silicone 1 , it is preferred to convey in the state that the sheet is placed on a long sheet-like carrier substrate (supporting substrate) 5 to be conveyed using a conveying roller 7 as necessary.
  • the porous silicone sheet 1 formed into a sheet by skiving processing can be conveyed without fracture.
  • the carrier substrate 5 may be arranged on only one side of the porous silicone sheet 1 and may be arranged on both sides thereof.
  • the carrier substrate 5 a substrate having tensile strength to an extent such that it does not fracture during conveying can be appropriately used.
  • the carrier substrate that can be used include a mesh comprising a nonwoven fabric, plastic or the like, and various sheets comprising a paper, plastic or the like.
  • a cleaning step of cleaning the porous silicone sheet obtained by the sheet forming step is carried out.
  • impurities such as unreacted precursors, a catalyst and a surfactant remained in the porous silicone sheet are removed. Since the porous silicone sheet is thinned, impurities in the sheet can be satisfactorily removed by cleaning.
  • the cleaning method is not particularly limited, and at least one of various cleaning methods warm water cleaning, ultrasonic cleaning, suction by suction roll, microbubble cleaning, shower-spray cleaning, cleaning by vibration using punching metal roll and chrysanthemum type roll together (FV cleaning system, see JP-A 2006-320811), and the like can be appropriately be used.
  • various cleaning methods warm water cleaning, ultrasonic cleaning, suction by suction roll, microbubble cleaning, shower-spray cleaning, cleaning by vibration using punching metal roll and chrysanthemum type roll together (FV cleaning system, see JP-A 2006-320811), and the like can be appropriately be used.
  • At least one of various solvents such as water, methanol, ethanol, isopropyl alcohol, dioxane, ether, butyl acetate, acetonitrile, chloroform, acetone, toluene, benzene and dichloromethane can be appropriately used as a cleaning liquid in conducting a cleaning method using a cleaning liquid.
  • a drying step of drying the porous silicone sheet is carried out.
  • the porous silicone sheet after the cleaning step is dipped in a non-polar solvent such as normal hexane to perform solvent substitution, and then dried, for example, at 20 to 80° C. for 5 to 24 hours.
  • a porous silicone sheet having a monolithic structure as a xerogel is obtained.
  • the sheet may be dried after substituting with the non-polar solvent as described before, but may be dried in the state that a part or the whole of the sheet is dipped in a cleaning liquid, without passing through a substitution step.
  • a porous silicone sheet having a monolithic structure as a xerogel can be obtained by subjecting the porous silicone sheet after the cleaning step to supercritical drying using carbon dioxide gas or the like.
  • a rolling step of rolling the porous silicone sheet may be further carried out, as necessary.
  • a rolled-body of the porous silicone sheet having communicating pores and a three-dimensional network silicone skeleton which forms the pores and which is formed by a copolymerization of a bifunctional alkoxysilane and a trifunctional alkoxysilane can be produced.
  • the rolling step is not particularly limited so long as it can form the porous silicone sheet into a roll form. From the standpoint of production efficiency, it is preferred to wind up the sheet in a roll form while conveying a long porous silicone sheet produced by skiving processing.
  • the porous silicone sheet 1 may be rolled together with the carrier substrate 5 as shown in FIG. 1 , but only the porous silicone sheet 1 may be rolled.
  • a sheet-formed thin porous silicone sheet can be wound up in a roll form.
  • the porosity of the porous silicone sheet is not particularly limited, but is preferably 50% or more, more preferably 80% or more, and still more preferably 90% or more. In case where the porosity is less than 50%, flexibility and lightness may be deteriorated. On the other hand, when the porosity is too high, mechanical strength may be deteriorated. Therefore, the porosity is preferably 95% or less.
  • the average pore size of the communicating pores in the porous silicone sheet (porous silicone body) is not particularly limited, but is, for example, from 50 to 50,000 nm.
  • the skeleton diameter of the silicone skeleton is not particularly limited, but is, for example, from 50 to 10,000 nm.
  • the average pore size of the communicating pores in the porous silicone body can be measured by SEM, optical microscope or the like. Furthermore, the skeleton diameter of the silicone skeleton can be measured by SEM, optical microscope or the like.
  • the silicone skeleton of the porous silicone sheet obtained by the production method of the present embodiment is a three-dimensional network silicone skeleton formed by the copolymerization of a bifunctional alkoxysilane and a trifunctional alkoxysilane.
  • the porous silicone sheet has a monolithic structure having the three-dimensional network silicone skeleton thus formed and communicating pores, and as a result, has high flexibility and also high heat resistance on the basis of a siloxane bond. Therefore, the porous silicone sheet can be usefully used as a damping material, a vibration-proof material, a cushioning material, a heat insulating material, a sound absorbing material, a permeable member and the like in the fields of aviation, space, automobile, nuclear powder facility, ship and the like.
  • n-Hexadecyltrimethylammonium chloride 10 g as a surfactant and urea (50 g) were added to 5 mM acetic acid aqueous solution (150 mL), followed by mixing those in a glass vessel under stirring.
  • Methyl trimethoxysilane (30 mL) and dimethyl dimethoxysilane (20 mL) as precursors were added to the glass vessel, followed by stirring with a stirrer for 60 minutes. After stirring, the resulting solution was transferred to a cylindrical closed vessel, and heated at 80° C. for 24 hours, thereby hydrolyzing urea to form basic conditions. The precursors hydrolyzed were polycondensed by a sol-gel reaction under the basic conditions.
  • the wet gel (swallen gel) obtained was allowed to stand in a freezer of ⁇ 10° C. for 5 hours in the state of placing the wet gel in the vessel, and formed into a frozen state.
  • the cylindrical wet gel in a frozen state was taken out of the vessel, a mandrel was driven into the cylindrical wet gel along a center axis thereof, and the cylindrical wet gel was rotated as the mandrel driven being an axis in one direction at a constant peripheral velocity of 0.5 m/min.
  • a cutting blade was pushed on the rotating cylindrical wet gel such that an angle ⁇ of ⁇ ATB shown in FIG.
  • the frozen porous silicone sheet produced was passed through hot water at 60° C. in a distance of 50 m while conveying the sheet at a speed of 0.5 m/min in the state of placing on a polypropylene mesh substrate as a carrier substrate, thereby removing impurities by cleaning, and then dried at 70° C. for 2 hours. Thereafter, the porous silicone sheet was wound up to obtain the porous silicone body formed into a sheet in a roll form (rolled-body of porous silicone sheet). As a result of measuring an apparent specific density of the porous silicone sheet obtained, it was 0.09 g/cc.
  • This apparent specific density was equal to an apparent specific density (0.15 g/cc or less) of a small piece of a normal porous silicone sheet (after appropriately removing impurities) manually prepared without conducting freezing and skiving processing treatments. Therefore, it was confirmed that impurities could be appropriately removed.
  • a porous silicone body formed into a sheet in a roll form was obtained under the same conditions as in Example 1, except that cleaning by FV cleaning method (a method in which a chrysanthemum type rotor rotates in punching metal roll to generate water flow in an opening part of the punching metal roll, and an object to be cleaned is brought into contact with the water flow to perform cleaning, number of revolution of chrysanthemum type rotor: 450 rpm, cleaning liquid: water, water temperature: 25° C., path length: 10 m) was conducted as the cleaning step. Similar to Example 1, as a result of measuring an apparent specific density of the porous silicone body prepared, it was a normal numerical value of 0.09 g/cc, and it was confirmed that impurities could be appropriately removed.
  • FV cleaning method a method in which a chrysanthemum type rotor rotates in punching metal roll to generate water flow in an opening part of the punching metal roll, and an object to be cleaned is brought into contact with the water flow to perform cleaning
  • the wet gel prepared by the method described in Example 1 was allowed to stand and dried in an oven at 70° C. for 24 hours in the state that the gel was placed in the vessel to obtain a porous silicone body.
  • an apparent specific gravity of the porous silicone body obtained it was 0.30 g/cc.
  • This value exceeded a normal numerical value (0.15 g/cc or less) of an apparent specific gravity of a porous silicone body prepared in an appropriate manner, and this fact suggested that impurities remain.
  • a water contact angle (5 ⁇ L)
  • water droplets permeated It was confirmed from this that impurities derived from a surfactant remain. (In case where impurities were normally removed, water droplets do not permeate, and water repellency of a water contact angle of 140° or more is shown).
  • the wet gel prepared in the method described in Example 1 was taken out of the vessel under atmospheric pressure without freezing.
  • the wet gel could not maintain its shape due to its weight, and a mandrel could not be inserted therein. As a result, skiving processing could not be performed.

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  • Health & Medical Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Manufacturing & Machinery (AREA)
  • Mechanical Engineering (AREA)
  • Manufacture Of Porous Articles, And Recovery And Treatment Of Waste Products (AREA)
  • Silicon Polymers (AREA)
  • Manufacture Of Macromolecular Shaped Articles (AREA)
  • Silicon Compounds (AREA)
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Publication number Priority date Publication date Assignee Title
US11820114B2 (en) 2015-04-17 2023-11-21 Nitto Denko Corporation Method for producing porous silicone sheet, frozen body, and porous silicone sheet rolled-body

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140076070A1 (en) * 2012-09-19 2014-03-20 Kazuki Nakanishi Monolithic silicone and method of separation, purification and concentration therewith

Family Cites Families (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2571881B2 (ja) * 1991-07-11 1997-01-16 リグナイト株式会社 シリコーン多孔質体の製造方法
US5362761A (en) 1991-07-11 1994-11-08 Lignyte Co., Ltd. Process for fabricating porous silicone product
JP3431197B2 (ja) * 1993-01-22 2003-07-28 明星工業株式会社 ゾル−ゲル法によるシリカ多孔質体の製造方法
JP3397255B2 (ja) 1993-07-30 2003-04-14 直弘 曽我 無機系多孔質体の製造方法
JP2893104B2 (ja) 1994-03-14 1999-05-17 直弘 曽我 有機官能基の結合した無機系多孔質体の製造方法
JPH08300567A (ja) * 1995-04-28 1996-11-19 Matsushita Electric Works Ltd エアロゲルパネルの製法
US7771609B2 (en) * 2002-08-16 2010-08-10 Aerogel Technologies, Llc Methods and compositions for preparing silica aerogels
EP1486244A1 (de) 2003-06-12 2004-12-15 Mann + Hummel GmbH Filterelement mit hydrophoben Eigenschaften
WO2005068537A1 (ja) * 2004-01-15 2005-07-28 Matsushita Electric Industrial Co., Ltd. 多孔体およびその製造方法
JP2005350519A (ja) * 2004-06-08 2005-12-22 Matsushita Electric Ind Co Ltd 多孔体およびその製造方法
JP2006241275A (ja) * 2005-03-02 2006-09-14 Chisso Corp シロキサン系多孔質体の製造方法
JP5215584B2 (ja) * 2007-04-06 2013-06-19 株式会社Ｎｔｔファシリティーズ リチウムイオン二次電池用セパレータ、これを用いるリチウムイオン二次電池、及びリチウムイオン二次電池の製造方法
JP2010120780A (ja) * 2008-11-17 2010-06-03 Emaus Kyoto:Kk 二重細孔有機鎖無機多孔質体、二重細孔有機鎖無機多孔質体の製造方法、およびクロマトグラフィー用カラムの製造方法
US8329290B2 (en) * 2008-12-22 2012-12-11 Nitto Denko Corporation Silicone resin composition
CN101497444B (zh) * 2009-03-04 2012-07-18 中国科学院广州能源研究所 一种真空冷冻干燥法制备大比表面积纳米多孔材料的方法
JP5640591B2 (ja) * 2010-09-14 2014-12-17 コニカミノルタ株式会社 断熱シート
WO2016127084A1 (en) * 2015-02-05 2016-08-11 Aeroger Technologies, Llc Systems and methods for producing aerogel material
JP6469508B2 (ja) 2015-04-17 2019-02-13 日東電工株式会社 シリコーン多孔質シートの製造方法、凍結体及びシリコーン多孔質シートのロール体
US20170210092A1 (en) * 2016-01-27 2017-07-27 W. L. Gore & Associates, Inc. Insulating structures

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20140076070A1 (en) * 2012-09-19 2014-03-20 Kazuki Nakanishi Monolithic silicone and method of separation, purification and concentration therewith

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US11820114B2 (en) 2015-04-17 2023-11-21 Nitto Denko Corporation Method for producing porous silicone sheet, frozen body, and porous silicone sheet rolled-body

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