JP5465130B2 - Fiber composite and method for producing the same - Google Patents

Description

  The present invention relates to a fiber composite and a method for producing the same. More specifically, the present invention relates to a material that is suitably used for a substrate, has a small linear expansion coefficient, is lightweight, and has transparency, heat resistance, and flexibility.

  Conventionally, glass plates are generally used for substrates such as liquid crystal display device substrates, organic EL display device substrates, color filter substrates, and solar cell substrates. However, glass has drawbacks such as being easily broken as a material, not being bent, having a large specific gravity, and being unsuitable for weight reduction.

  Therefore, in recent years, investigation of plastic materials has begun as an alternative. However, since general-purpose plastic materials have a larger linear expansion coefficient than silver or copper used for electric circuit wiring, there are problems such as peeling and disconnection of wiring. Furthermore, there has never been a plastic material having high transparency, weather resistance and a small birefringence at the same time.

  Silsesquioxane having a cage-type or partial-cage-type structure is expected to exhibit a unique function due to its characteristic structure, and has attracted attention from various fields and has been studied for application. In particular, because of its high transparency and heat resistance, it has attracted attention and has been studied as an alternative to glass.

  For example, as a film substrate material used for a flat panel display, a copolymer of a silicone resin containing a silsesquioxane having a cage structure and an acrylic resin is disclosed (Patent Documents 1 and 2). Since these contain acrylic resin, there is no problem in mechanical strength and transparency.

  A film substrate produced using a polymer containing a silsesquioxane skeleton in the main chain of a polymer without using an acrylic resin is known (Patent Documents 3 and 4). In addition to transparency, these film substrates have no deterioration against ultraviolet rays and are excellent in weather resistance.

  For the purpose of improving the fluidity of polyphenylene ether (PPE), an attempt has been made to form a film-like molded body with a modified PPE incorporating a cage silsesquioxane and a glass cloth.

  However, the weather resistance of the copolymer of a silicone resin and an acrylic resin containing silsesquioxane having a cage structure described in Patent Documents 1 and 2 is often impaired.

  Moreover, the film substrate produced using the polymer containing the silsesquioxane skeleton in the main chain of the polymers described in Patent Documents 3 and 4 has a problem that the resulting film has a large linear expansion coefficient.

  Furthermore, a film-like molded body made of modified PPE and glass cloth incorporating silsesquioxane having a cage structure has a high processing temperature of 280 ° C., and thus has a difficulty in workability (Patent Document 5).

JP 2004-123936 A JP 2006-096885 A JP 2006-233154 A JP 2008-112942 A JP 2008-201978 A

  Accordingly, an object of the present invention is to provide a fiber composite obtained by curing a mixture containing a fiber and silsesquioxane, which has a small linear expansion coefficient and excellent transparency, heat resistance and flexibility. And

  The inventors have studied to solve the above problems. As a result, a fiber composite obtained by curing a mixture containing a fiber having a fiber diameter of 30 nm or less and a composition containing silsesquioxane or a polymer thereof has high transparency and heat resistance, And it discovered that a linear expansion coefficient was small and came to complete this invention.

That is, the present invention is as follows.
1. A fiber composite obtained by curing a mixture comprising a fiber having a fiber diameter of 30 nm or less and a composition containing silsesquioxane or a silsesquioxane polymer.
2. 2. The fiber composite according to item 1, wherein the fiber is chitin fiber.
3. 3. The fiber composite according to item 2, wherein the chitin fiber is a chitin nonwoven fabric.
4). 4. The fiber composite according to any one of items 1 to 3, wherein the silsesquioxane is a silsesquioxane having a cage type or partial cage type structure.
5. 5. The fiber composite according to item 4, wherein the silsesquioxane having the cage type or partial cage type structure is at least one selected from the compounds represented by the general formulas (A-1) to (A-3). .

In the general formulas (A-1) to (A-3), each R is independently hydrogen, any hydrogen may be replaced with fluorine, and —CH ₂ — not adjacent to each other is —O— or cycloalkylene. The alkyl having 1 to 45 carbon atoms which may be substituted with, cycloalkyl having 4 to 8 carbon atoms, alkyl having 1 to 10 carbon atoms, or aryl optionally substituted with halogen. R ¹ is a group independently selected from alkyl having 1 to 4 carbon atoms, cyclopentyl, cyclohexyl and phenyl. At least one X is hydrogen, a vinyl group, or a polymerizable functional group having 1 to 10 carbon atoms, alkyl, cycloalkyl, or phenyl, and the remaining X is a group defined as in R ¹ It is.
6). 6. The fiber composite according to item 5, wherein in the general formulas (A-1) to (A-3), the polymerizable functional group is oxiranyl, 3,4-epoxycyclohexyl, oxetanyl, acrylic, or (meth) acrylic. body.
7). 7. The fiber composite according to any one of items 1 to 6, wherein the linear expansion coefficient is 120 ppm / K or less.
8). A method for producing a fiber composite of a fiber having a fiber diameter of 30 nm or less and silsesquioxane, comprising the following steps (1) and (2).
(1) A step of impregnating a fiber having a fiber diameter of 30 nm or less with a composition containing silsesquioxane or a polymer thereof (2) The silsesquioxane impregnated in the fiber in step (1) or the 8. Curing reaction of the composition containing a polymer 9. The method according to item 8, wherein the fiber is chitin fiber.
10. 10. The method according to item 9, wherein the chitin fiber is a chitin nonwoven fabric.
11. 11. The production method according to any one of items 8 to 10, wherein the silsesquioxane is at least one selected from compounds represented by general formulas (A-1) to (A-3).

In the general formulas (A-1) to (A-3), each R is independently hydrogen, any hydrogen may be replaced with fluorine, and —CH ₂ — not adjacent to each other is —O— or cycloalkylene. The alkyl having 1 to 45 carbon atoms which may be substituted with, cycloalkyl having 4 to 8 carbon atoms, alkyl having 1 to 10 carbon atoms, or aryl optionally substituted with halogen. R ¹ is a group independently selected from alkyl having 1 to 4 carbon atoms, cyclopentyl, cyclohexyl and phenyl. At least one X is hydrogen, a vinyl group, or an alkyl, cycloalkyl, or phenyl having 1 to 10 carbon atoms having a polymerizable functional group, and the remaining X is a group defined as in R ^1. is there.
12 12. The production method according to 11 above, wherein in the general formulas (A-1) to (A-3), the polymerizable functional group is oxiranyl, 3,4-epoxycyclohexyl, oxetanyl, acrylic or (meth) acrylic. .
13. 13. The production method according to any one of items 8 to 12, wherein the polymer has a weight average molecular weight of 3,000 to 4,000,000.
14 14. The manufacturing method according to any one of items 8 to 13, wherein in the step (1), the composition contains a polymerization initiator.
15. 15. The production method according to 14 above, wherein the polymerization initiator is a cationic polymerization initiator or a radical polymerization initiator.
16. 16. The method according to item 14 or 15, wherein in the step (1), the composition contains a curing agent.
17. 17. The production method according to 16 above, wherein the curing agent is an acid anhydride or an amine.
18. 18. The manufacturing method according to any one of items 8 to 17, wherein in the step (2), the curing reaction is a thermosetting reaction.
19. 16. The manufacturing method according to any one of items 8 to 15, wherein in the step (2), the curing reaction is a photocuring reaction.
20. 20. The method according to any one of items 8 to 19, wherein the composition further contains an epoxy resin or an oxetane resin.
21. 21. A fiber composite produced by the production method according to any one of items 8 to 20.
22. A substrate using the fiber composite according to any one of items 1 to 7 and 21.

  A fiber composite obtained by curing a mixture containing a fiber having a fiber diameter of 30 nm or less of the present invention and a composition containing silsesquioxane or a polymer thereof (hereinafter also referred to as a fiber composite of the present invention). ) Has a small linear expansion coefficient and is excellent in transparency and flexibility.

  Therefore, the fiber composite of the present invention can be used as an alternative to a glass plate, such as a liquid crystal display element substrate, an organic EL display element substrate, a color filter substrate, a solar cell substrate, a touch panel substrate, or a plasma display substrate. It can be suitably used for a substrate.

  The present invention will be specifically described below.

  The fiber composite of the present invention is a fiber composite obtained by curing a mixture containing a fiber having a fiber diameter of 30 nm or less and a composition containing silsesquioxane or a polymer thereof. Curing a mixture containing a fiber having a fiber diameter of 30 nm or less and a composition containing silsesquioxane or a polymer thereof means that silsesquioxane or a polymer thereof is applied to a fiber having a fiber diameter of 30 nm or less. It is impregnated with a composition containing, and the composition is cured.

  20-80 mass% is preferable with respect to the total mass of a fiber composite, and, as for the content rate of the fiber whose fiber diameter in the fiber composite of this invention is 30 nm or less, 30-70 mass% is more preferable. In the fiber composite of the present invention, the mass ratio of the fiber having a fiber diameter of 30 nm or less and the silsesquioxane is preferably 2: 8 to 8: 2, and more preferably 3: 7 to 7: 3.

(fiber)
The fiber diameter of the fiber used for the fiber composite of the present invention is 30 nm or less, preferably 20 nm or less, and more preferably 15 nm or less. Moreover, although a minimum is not specifically limited, Usually, it is 4 nm. The fiber diameter can be measured with a scanning electron microscope (SEM), a field emission electron microscope, or the like.

  The fiber having a fiber diameter of 30 nm or less is not particularly limited, but has the advantages of high transparency, high purity compared to cellulose fiber, easy preparation from dry chitin, and low hygroscopicity. Therefore, chitin fiber is preferable.

  Chitin, the raw material of chitin fiber, is a natural material contained in a great many organisms, such as shrimp, crabs, insect rinds and fungal cell walls such as mushrooms. Its structure is similar to cellulose, but N-acetyl-D-glucosamine is an amino polysaccharide with a long chain connection (hundreds to thousands), so it is notable in terms of advanced functions and harmony with the environment. Is a high polymer material.

  Chitin is a biological resource that is estimated to be 100 billion tons of synthesized on the earth in one year. In addition, because it is a sustainable resource, it contributes significantly to the reduction of carbon dioxide, which affects global warming.

  The chitin fiber may be obtained by the following method or the like, or may be a commercially available product. Specific examples of the method for obtaining chitin fibers include a method including the following steps (i) and (ii).

(I) A chitin dispersion in which chitin powder is dispersed in a solvent is prepared. In the case of using chitin that has been purified from natural products and chitin that has a relatively low degree of deacetylation, the solvent is a mixture of halogenated hydrocarbon and trichloroacetic acid, N-methylpyrrolidone, or dimethylacetamide and lithium chloride. Is preferred. When chitin and chitosan having a high degree of deacetylation are used, the solvent is preferably an acid solution such as acetic acid. The chitin concentration in the chitin dispersion is preferably 0.5 to 2.0% by mass.
(Ii) After stirring the chitin dispersion obtained in step (i), the chitin is ground and defibrated. The temperature during stirring is preferably room temperature to 40 ° C. Chitin can be defibrated using a commercially available stone mill grinder (for example, Supermass colloider, manufactured by Masuko Sangyo). The grinding wheel is preferably rotated at 1000 to 1500 rpm during grinding, and the number of grinding is preferably 1 to 3 times. The temperature during grinding is preferably room temperature to 60 ° C.

  The chitin fiber is preferably a chitin nonwoven fabric. The chitin nonwoven fabric in the present invention is a nonwoven fabric mainly composed of chitin, and is an aggregate of chitin fibers.

  When using a chitin nonwoven fabric as a fiber whose fiber diameter is 30 nm or less, it is preferable that the thickness of a chitin nonwoven fabric is 20-500 micrometers, and it is more preferable that it is 50-200 micrometers. By setting it as the said range, the composite_body | complex excellent in transparency, intensity | strength, and thermal expansibility can be prepared.

Further, the specific volume of chitin nonwoven fabric is preferably 5 to 30 cm ³ / g, and more preferably 10 to 15 cm ³ / g. By setting it as the said range, the fiber composite whose fiber content rate is 25-50 mass% can be created.

  The chitin nonwoven fabric used for the fiber composite of the present invention can be obtained by a method of forming a chitin fiber suspension by papermaking or coating, or a method of drying a gel film. Specifically as a manufacturing method of a chitin nonwoven fabric, the method containing the following process (i)-(iii) is mentioned, for example.

(I) The chitin fiber suspension is stirred and filtered. The concentration of chitin fibers in the chitin fiber suspension is preferably 0.1 to 10% by mass. The stirring time is preferably 0.5 to 1 hour. Filtration is performed by placing a membrane filter on a metal mesh filter, pouring a chitin fiber suspension from the membrane filter and filtering under reduced pressure.
(Ii) After the filtration under reduced pressure in step (i), before completely removing water, preferably adding pure water and filtering again under reduced pressure, based on the mass of the chitin fiber suspension that has been poured Is preferably carried out 2 to 5 times. Furthermore, on the basis of the mass of the chitin fiber suspension that has been poured, the operation of preferably adding a highly polar organic solvent and filtering under reduced pressure is preferably carried out 1 to 3 times, so that the chitin fibers are placed on the membrane filter. Get the deposit. Examples of the organic solvent include ethanol, isopropanol, methanol, and acetone.
(Iii) A chitin nonwoven fabric can be obtained by pressurizing and heating the chitin fiber deposit obtained in step (ii). The pressure heating conditions are preferably a pressure of 0.1 to 2 MPa, a temperature of 60 to 100 ° C., and a time of 0.5 to 2 hours.

(Silsesquioxane)
The silsesquioxane is preferably a silsesquioxane having a cage or partial cage structure. The cage silsesquioxane is a silsesquioxane having a closed space. Further, the partial cage silsesquioxane is a compound having a structure in which a space where a part of the Si—O—Si bond forming the skeleton is cleaved and closed is opened.

  The silsesquioxane having a cage structure is preferably at least one selected from compounds represented by the following general formulas (A-1) and (A-2). As the silsesquioxane having a partial cage structure, a compound represented by the following general formula (A-3) is preferable. Among the compounds represented by the following general formulas (A-1) to (A-3), compatibility with organic solvents, epoxy resins, oxetane resins, and (meth) acrylic acid monomers, curing agents, and polymerization initiators. In addition, in consideration of the solubility of various additives, the compound represented by the general formula (A-3) is preferable.

(Production example of fiber composite using silsesquioxane)
At least one selected from silsesquioxanes represented by the following general formulas (A-1) to (A-3), and a composition to which other monomers are added as necessary, the fiber diameter is 30 nm or less. A fiber composite can be obtained by impregnating the fibers into a mixture and curing the mixture. High transparency can be maintained by allowing silsesquioxane to enter every corner of the fiber void.

In the general formulas (A-1) to (A-3), each R is independently hydrogen, any hydrogen may be replaced with fluorine, and —CH ₂ — not adjacent to each other is —O— or cycloalkylene. The alkyl having 1 to 45 carbon atoms which may be substituted with, cycloalkyl having 4 to 8 carbon atoms, alkyl having 1 to 10 carbon atoms, or aryl optionally substituted with halogen. Halogen includes chlorine, bromine and fluorine, with fluorine being particularly preferred.

R ¹ is a group independently selected from alkyl having 1 to 4 carbon atoms, cyclopentyl, cyclohexyl and phenyl. At least one X is hydrogen, a vinyl group, or a polymerizable functional group having 1 to 10 carbon atoms, alkyl, cycloalkyl, or phenyl, and the remaining X is a group defined as in R ¹ It is.

  When R is hydrogen, only one X may be hydrogen. When X has a vinyl group or a polymerizable functional group, it is preferable that at least two X have a polymerizable functional group.

  The polymerizable functional group is not particularly limited as long as it is a functional group capable of addition polymerization, ring-opening polymerization, or polycondensation. Examples of the functional group include epoxy such as 3,4-epoxycyclohexyl, oxetane such as oxiranyl, oxetanyl and 2-oxapropane-1,3-dioyl, acrylic or (meth) acrylic, alkenyl and amine. Of these, epoxy and oxetane are particularly preferable because of excellent transparency, heat resistance, and electrical properties.

  Specific examples of X include groups represented by the following formulas (a) to (h). In the present specification, a 3-membered cyclic ether is referred to as an epoxy, a 4-membered cyclic ether is referred to as an oxetane, and compounds each having two or more in one molecule may be referred to as an epoxy resin or an oxetane resin. .

In the formulas (a) to (h), R ² is alkylene having 1 to 10 carbons, and preferably alkylene having 1 to 6 carbons. One —CH ₂ — in the alkylene may be replaced by —O— or 1,4-phenylene. R ³ is hydrogen or alkyl having 1 to 6 carbon atoms, and is preferably hydrogen.

  The compounds represented by the general formulas (A-1) to (A-3) can be synthesized by a known production method.

  The silsesquioxane having a cage structure represented by the general formula (A-1) can be synthesized, for example, by the method described in International Publication No. 2003/024870 or JP-A-2006-265243. is there.

  Silsesquioxane having a cage structure represented by the general formula (A-2) can be synthesized, for example, by the method described in JP-A-2008-150478.

  Silsesquioxane having a partial cage structure represented by the general formula (A-3) can be easily synthesized, for example, by the method described in International Publication No. 2004/024741.

  The fiber composite of the present invention has high transparency and a low linear expansion coefficient. The total light transmittance of the fiber composite of the present invention is preferably 70 to 95%, and more preferably 80 to 95%. Moreover, it is preferable that it is 1-30, and, as for turbidity, it is more preferable that it is 1-20. The total light transmittance and turbidity can be measured by the methods described later in Examples.

  The linear expansion coefficient of the fiber composite of the present invention is preferably 120 ppm / K or less, and more preferably 30 ppm / K or less. By setting it as this range, the workability in the transparent substrate use of a fiber composite will improve remarkably. The linear expansion coefficient can be measured by the method described later in Examples.

  Although the thickness of the fiber composite of this invention is not specifically limited, It is preferable that it is 20-500 micrometers, and it is more preferable that it is 50-200 micrometers. By making it in the said range, the fiber composite excellent in transparency, intensity | strength, and thermal expansibility can be prepared.

The fiber composite of the present invention is obtained by a production method including the following steps (1) and (2).
(1) A step of impregnating a fiber having a fiber diameter of 30 nm or less with a composition containing silsesquioxane or a polymer thereof (2) The silsesquioxane impregnated in the fiber in step (1) or the Step for curing reaction of a composition containing a polymer Hereinafter, each step will be described separately.

(1) A step of impregnating a fiber having a fiber diameter of 30 nm or less with a composition containing silsesquioxane or a polymer thereof. Impregnation is performed by degassing under reduced pressure to remove dissolved air to remove silsesquioxane or its A composition containing a polymer is prepared, and the composition is applied to fibers having a fiber diameter of 30 nm or less so as to prevent bubbles from entering, and pressure is applied. The pressure is preferably 0.1 to 2 MPa.

In the step (1), the amount of silsesquioxane or a polymer thereof impregnated in a fiber having a fiber diameter of 30 nm or less is preferably 0.5 to 2.0 g / cm ³ , and preferably 0.5 to 1 g. / Cm ³ is preferable.

(Production example of fiber composite using silsesquioxane polymer)
The silsesquioxane polymer is added by adding at least one selected from silsesquioxanes represented by the general formulas (A-1) to (A-3), if necessary, other monomers. By polymerizing, ring-opening polymerization, or polycondensation, it can be made into a composition by making it a B-stage, that is, a polymer that is re-soluble in a solvent (not completely cured but semi-cured). . The resulting composition is impregnated into fibers having a fiber diameter of 30 nm or less to form a mixture, and the mixture is cured to obtain a fiber composite.

  In addition, the silsesquioxane polymer is formed by adding at least one selected from silsesquioxanes represented by the general formulas (A-1) to (A-3) by addition polymerization, ring-opening polymerization, or heavy polymerization. By condensing, it becomes B-stage, that is, a polymer that is re-soluble in a solvent (a state that is not completely cured but semi-cured), and separately mixed with a polymer obtained by polymerizing other monomers. It can be a composition. At this time, the polymer obtained from another monomer is also required to be a polymer soluble in a solvent. The resulting composition is impregnated into fibers having a fiber diameter of 30 nm or less to form a mixture, and the mixture is cured to obtain a fiber composite.

  In addition, the silsesquioxane polymer is formed by adding at least one selected from silsesquioxanes represented by the general formulas (A-1) to (A-3) by addition polymerization, ring-opening polymerization, or heavy polymerization. By condensation, the polymer can be made into a B-stage, that is, a polymer that is re-soluble in a solvent (not completely cured but in a semi-cured state), and further added with other monomers. The resulting composition is impregnated into fibers having a fiber diameter of 30 nm or less to form a mixture, and the mixture is cured to obtain a fiber composite.

  The weight average molecular weight of the silsesquioxane polymer is preferably in the range of 3,000 to 4,000,000, and more preferably in the range of 10,000 to 200,000. The weight average molecular weight of the silsesquioxane polymer can be measured by the method described later in Examples.

  As said other monomer, the compound represented by a following formula (B) is mentioned, for example.

In the formula (B), each R ⁴ is independently alkyl or phenyl having 1 to 4 carbon atoms, m is an integer of 0 to 1000, and preferably an integer of 0 to 150. Y is hydrogen or a vinyl group.

  As the compound (B), a commercially available compound can be obtained, and even a non-commercial compound can be produced by referring to, for example, a method described in JP-A-2003-252995.

  For example, in the general formulas (A-1) to (A-3), as an example in which X is an alkenyl group and Y is hydrogen in the formula (B), International Publication No. 2004/018084 By performing the hydrosilylation reaction of silsesquioxane having an alkenyl group and at least one of silsesquioxane having an SiH group and polydiorganosiloxane in the presence of a hydrosilylation catalyst described later, A polymer of silsesquioxane having an average molecular weight of 3,000 to 4,000,000 can be obtained.

  The hydrosilylation reaction can proceed more easily by using a hydrosilylation catalyst as a polymerization initiator. Examples of the hydrosilylation catalyst include a Karstedt catalyst and a Spier catalyst.

The hydrosilylation catalyst is generally a well-known catalyst, and has a high activity. Therefore, if a small amount is added, the reaction can proceed sufficiently. Therefore, the amount used is usually 10 ⁻⁹ to 1 mol%, more preferably 10 ⁻⁷ to 10 ⁻³ mol% in terms of the platinum group metal contained in the catalyst relative to Si—H.

(Polymerization initiator)
The composition containing silsesquioxane or a polymer thereof preferably contains a polymerization initiator. As the polymerization initiator, a cationic polymerization initiator, a radical polymerization initiator, and the like can be appropriately selected and used depending on the type of polymerizable functional group possessed by the silsesquioxane, but a cationic polymerization initiator is usually preferable.

  Examples of the cationic polymerization initiator include an active energy ray cationic polymerization initiator that generates a cationic species or Lewis acid by active energy rays such as ultraviolet rays, and a thermal cationic polymerization initiator that generates a cationic species or Lewis acid by heat. Can be mentioned.

Examples of the active energy ray cationic polymerization initiator include metal fluoroboron complex salts and boron trifluoride complex compounds, bis (perfluoroalkylsulfonyl) methane metal salts, aryldiazonium compounds, and aromatic oniums of Group VIa elements of the periodic table Salts, aromatic onium salts of group Va elements of the periodic table, dicarbonyl chelates of group IIIa to Va elements, thiopyrylium salts, MF ₆ (group VIb elements of the periodic table in the form of anions; M is phosphorus, antimony And arylsulfonium complex salts, aromatic iodonium complex salts and aromatic sulfonium complex salts and bis [4- (diphenylsulfonio) phenyl] sulfide-bis-hexafluorometal salts and mixed ligand metals of iron compounds And salts and silanol-aluminum complexes That. Some of these salts may be commercially available.

  Examples of the thermal cationic polymerization initiator include cationic and protonic acid catalysts such as triflic acid salt and boron trifluoride. Of these, a triflic acid salt is preferable.

  Examples of the triflic acid salt include diethyl ammonium triflate, diisopropyl ammonium triflate and ethyl diisopropyl ammonium triflate.

  Of the aromatic onium salts that are also used as the active energy ray cationic polymerization initiator, those that generate cationic species by heat can also be used as the thermal cationic polymerization initiator. Preferred examples of the aromatic onium salt include diazonium salts, iodonium salts, sulfonium salts, and phosphonium salts.

  Among these cationic polymerization initiators, an aromatic onium salt is preferable in that it is excellent in handleability and the balance between latency and curability. A cationic polymerization initiator can be used individually or in combination of 2 or more types.

  Although the usage-amount of a polymerization initiator is not specifically limited, 0.01-10.0 mass% is preferable with respect to the mass of silsesquioxane or its polymer, and 0.05-3.0 mass% is more. preferable. By setting it within this range, the curing reaction can proceed sufficiently to obtain the desired cured product, the physical properties of the cured product can be prevented from being lowered, and coloring of the cured product can be suppressed.

(Curing agent)
The composition containing silsesquioxane or a polymer thereof preferably contains a curing agent. The curing agent is not particularly limited as long as it is a compound used for curing a general resin, and amines and acid anhydrides can be used.

  Specific examples of the acid anhydride used as the curing agent include phthalic anhydride, maleic anhydride, trimellitic anhydride, pyromellitic anhydride, hexahydrophthalic anhydride, 3-methyl-cyclohexanedicarboxylic anhydride, 4-methyl- Cyclohexanedicarboxylic acid anhydride, mixture of 3-methyl-cyclohexanedicarboxylic acid anhydride and 4-methyl-cyclohexanedicarboxylic acid anhydride, tetrahydrophthalic anhydride, nadic acid anhydride, methylnadic acid anhydride, norbornane-2,3-dicarboxylic acid Anhydrides, methylnorbornane-2,3-dicarboxylic acid anhydride and cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride and their derivatives.

  Among these, 4-methyl-cyclohexanedicarboxylic acid anhydride and a mixture of 3-methyl-cyclohexanedicarboxylic acid anhydride and 4-methyl-cyclohexanedicarboxylic acid anhydride are preferable because they are easy to handle because they are liquid at room temperature. .

  Specific examples of amines used as curing agents include ethylenediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, dimethylaminopropylamine, diethylaminopropylamine, hexamethylenetriamine, biscyanoethylamine, and tetramethylguanidine, pyridine, piperidine, Mesenediamine, isophoronediamine, 1,3-bisaminomethyl-cyclohexane, bis (4-amino-cyclohexyl) methane, bis (4-amino-3-methyl-cyclohexyl) methane, benzylmethylamine, α-methyl-benzylmethyl And amines, m-phenylenediamine, m-xylylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone and diaminodiphenyl ether. It is.

  The proportion of the curing agent used is preferably 0.7 to 1.2 equivalents of the curing agent with respect to 1 equivalent of the polymerizable functional group contained in the silsesquioxane, 0.9 to 1.1 equivalents. More preferably. By setting it within the range, a cured product that is completely cured and can be obtained can be obtained.

(Curing accelerator)
A curing accelerator may be used in combination with a curing agent. Examples of the curing accelerator include tetraphenylphosphonium bromide, tetrabutylphosphonium bromide, methyltriphenylphosphonium bromide, ethyltriphenylphosphonium bromide, n-butyltriphenylphosphonium bromide, 1,8-diazabicyclo (5,4,0). Examples include undecene-7, 2-methylimidazole and 2-phenyl-4-methylimidazole. However, it is not limited to these as long as it has good curability and is not colored.

  These curing accelerators may be used alone or in combination of two or more. Bicyclic amidines such as 1,8-diazabicyclo (5,4,0) undecene-7, and imidazoles such as 2-methylimidazole and 2-phenyl-4-methylimidazole can be obtained even in small amounts. It is more preferable because it exhibits high activity for a composition containing oxane or a polymer thereof and can be cured in a short time even at a relatively low curing temperature.

  The use ratio of the curing accelerator is not particularly limited as long as a curing accelerating effect is recognized, the physical properties of the cured product are not deteriorated, and the cured product is not colored. Generally, the mass ratio of the curing accelerator to the amount of silsesquioxane or its polymer is preferably 0.005 to 5.0 mass%, more preferably 0.05 to 1.0 mass%.

(solvent)
The solvent used for the preparation of the composition containing silsesquioxane or a polymer thereof is not particularly limited as long as it can dissolve the composition or the polymer.

  Examples of the solvent include hydrocarbon solvents such as hexane and heptane, aromatic hydrocarbon solvents such as toluene, xylene, mesitylene and anisole, diethyl ether, tetrahydrofuran (hereinafter referred to as THF), dioxane, 1,2-dimethoxyethane. Ether solvents such as 1,2-diethoxyethane and propylene glycol monomethyl ether, halogenated hydrocarbon solvents such as methylene chloride and carbon tetrachloride, ester solvents such as ethyl acetate, glycols such as propylene glycol monomethyl ether acetate Preferable examples include ester solvents, ketones such as methyl ethyl ketone, methyl isopropyl ketone, and methyl isobutyl ketone. These solvents may be used alone or in combination of two or more.

  Among these, toluene, mesitylene, anisole, tetrahydrofuran, cyclopentyl methyl ether, 1,2-dimethoxyethane, propylene glycol monomethyl ether acetate and 2- (2-ethoxyethoxy) ethyl acetate are preferable.

  In addition, it is not always necessary to use a solvent when impregnating a fiber having a fiber diameter of 30 nm or less with a silsesquioxane polymer. However, when diluted with a solvent, the resin concentration is 5 mass% or more and 99 mass%. It is preferable to set it as follows, and it is more preferable to set it as 30 to 90 mass%.

(Epoxy resin and oxetane resin)
You may mix | blend an epoxy resin or an oxetane resin with the fiber composite of this invention. Examples of the epoxy resin include bisphenol type epoxy resins (such as bisphenol A type epoxy resin, bisphenol F type epoxy resin and bisphenol S type epoxy resin), and epoxy resins having two oxiranyl (biphenyl type epoxy resin and hydrogenated bisphenol A). Type epoxy resin), polyfunctional heterocyclic epoxy resin (phenol novolak type epoxy resin, cresol novolak type epoxy resin, alkyl-modified triphenolmethane type epoxy resin, triglycidyl isocyanurate, etc.), epoxy having 3 or more oxiranyl Resin (polyfunctional alicyclic epoxy resin such as poly (epoxidized cyclohexene oxide)) and alicyclic epoxy resin (manufactured by Daicel Chemical Industries, Ltd., product name: Celoxide 2021) And the same product name: Celoxide 3000 and the same product name: Celoxide 2081).

  Examples of the oxetane resin include Aron Oxetane manufactured by Toagosei Co., Ltd., product names OXT-101: 3-ethyl-3-hydroxymethyloxetane, OXT-212: 2-ethylhexyloxetane, OXT-121: xylylenebisoxetane. And OXT-221: 3-ethyl-3 {[(3-ethyloxetane-3-yl) methoxy] methyl} oxetane.

  Two or more of these epoxy resins and oxetane resins may be used in combination. Of these, from the viewpoint of transparency, it is more preferable to use an alicyclic epoxy resin and an oxetane resin that are less colored.

  The blending ratio of the epoxy resin or oxetane resin is preferably 5 to 50% by mass, more preferably 10 to 30% by mass based on the mass of silsesquioxane or a polymer thereof.

  A fiber composite obtained by impregnating a fiber having a fiber diameter of 30 nm or less with a composition containing silsesquioxane not containing an epoxy resin and an oxetane resin or a composition containing a silsesquioxane polymer and curing it. Is naturally included in the fiber composite of the present invention. Such a fiber composite is preferable because it can be easily produced as compared with a conventional molded body.

(Antioxidant)
You may mix | blend antioxidant with the fiber composite of this invention. By blending an antioxidant, it is possible to prevent the oxidative deterioration and to form a molded product with little coloring.

  Examples of the antioxidant include phenol-based, sulfur-based and phosphorus-based antioxidants. The blending ratio of the antioxidant is not particularly limited, but is preferably 0.0001 to 1.0% by mass, more preferably 0.01 to 0.1% by mass based on the mass of silsesquioxane or a polymer thereof. preferable.

  Antioxidants include, for example, monophenols (2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-p-ethylphenol and stearyl-β- (3,5-di-t-butyl-4-hydroxyphenyl) propionate), bisphenols (2,2′-methylenebis (4-methyl-6-tert-butylphenol), 2,2′-methylenebis (4- Ethyl-6-tert-butylphenol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), 4,4′-butylidenebis (3-methyl-6-tert-butylphenol) and 3,9-bis [1,1-dimethyl-2- {β- (3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] 2,4,8,1 0-tetraoxaspiro [5,5] undecane, etc.), polymeric phenols (1,1,3-tris (2-methyl-4-hydroxy-5-tert-butylphenyl) butane, 1,3,5 -Trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, tetrakis- [methylene-3- (3 ', 5'-di-t-butyl-4' -Hydroxyphenyl) propionate] methane, bis [3,3′-bis- (4′-hydroxy-3′-t-butylphenyl) butyric acid] glycol ester, 1,3,5-tris (3 ′, 5 '-Di-t-butyl-4'-hydroxybenzyl) -S-triazine-2,4,6- (1H, 3H, 5H) trione and tocophenol), sulfur-based antioxidants (dilauryl-3,3 -Thiodipropionate, dimyristyl-3,3'-thiodipropionate and distearyl-3,3'-thiodipropionate), phosphites (rephenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite) Phyto, tris (nonylphenyl) phosphite, diisodecylpentaerythritol phosphite, tris (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (octadecyl) phosphite, cyclic neopentanetetra Irbi (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbi (2,4-di-t-butyl-4-methylphenyl) phosphite and bis [2-t-butyl-6 -Methyl-4- 2- (octadecyloxycarbonyl) ethyl} phenyl] hydrogen phosphite) and oxaphosphaphenanthrene oxides (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10- (3 5-Di-t-butyl-4-hydroxybenzyl) -9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide and 10-decyloxy-9,10-dihydro-9-oxa-10- Phosphaphenanthrene-10-oxide, etc.).

  The antioxidants can be used alone, but it is particularly preferable to use them in combination with phenol / sulfur or phenol / phosphorus. As commercially available phenolic antioxidants, IRGANOX 1010 (trade name) and IRGAFOS 168 (trade name) manufactured by Ciba Japan Co., Ltd. can be used singly or in combination. You can also.

(UV absorber)
You may mix | blend a ultraviolet absorber with the fiber composite of this invention. The weather resistance of a fiber composite can be improved by mix | blending a ultraviolet absorber.

  As a UV absorber, a general UV absorber for plastics can be used. The blending ratio is not particularly limited. The blending amount of the ultraviolet absorber is preferably 0.0001 to 1.0 mass%, more preferably 0.001 to 0.1 mass%, based on the mass of silsesquioxane or a polymer thereof.

  Examples of the ultraviolet absorber include salicylic acids such as phenyl salicylate, pt-butylphenyl salicylate and p-octylphenyl salicylate, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4. Octoxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone and 2-hydroxy-4-methoxy- Benzophenones such as 5-sulfobenzophenone, 2- (2′-hydroxy-5′-methylphenyl) benzotriazole, 2- (2′-hydroxy-5′-tert-butylphenyl) benzotriazole, 2- (2 ′ - Roxy-3 ′, 5′-ditert-butylphenyl) benzotriazole, 2- (2′-hydroxy-3′-tert-butyl-5′-methylphenyl) -5-chlorobenzotriazole, 2- (2 ′ -Hydroxy-3 ', 5'-ditert-butylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy-3', 5'-ditert-amylphenyl) benzotriazole and 2-{(2 Benzotriazoles such as '-hydroxy-3', 3 '', 4 '', 5 '', 6 ''-tetrahydrophthalimidomethyl) -5'-methylphenyl} benzotriazole, and bis (2,2,6 , 6-Tetramethyl-4-piperidyl) sebacate, bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate and bis Hindered amines such as 1,2,2,6,6-pentamethyl-4-piperidyl) [{3,5-bis (1,1-dimethylethyl) -4-hydroxyphenyl} methyl] butyl malonate; Can be mentioned.

  In the step (1), the following components (a) to (f) may be further blended with the composition containing silsesquioxane or the composition containing silsesquioxane polymer.

(A) Powdery reinforcing agents and fillers, for example, metal oxides such as aluminum oxide and magnesium oxide, silicon compounds such as fine powder silica, fused silica and crystalline silica, transparent fillers such as glass beads, and aluminum hydroxide Metal hydroxide, kaolin, mica, quartz powder, graphite and molybdenum disulfide.

(B) Colorants or pigments such as titanium dioxide, molybdenum red, bitumen, ultramarine blue, cadmium yellow, cadmium red and organic dyes.
(C) Flame retardants such as antimony trioxide, bromine compounds and phosphorus compounds.
(D) Ion adsorbent.
(E) Silane coupling agent.
(F) A nanoparticle dispersion of a metal oxide such as zirconia, titania, alumina, or silica.

  The blending amount of these components (a) to (f) is 0.01 to mass ratio with respect to the mass of silsesquioxane in the composition containing silsesquioxane or the composition containing silsesquioxane polymer. It is preferably 0.50.

(2) A step of curing reaction of a composition containing silsesquioxane or a polymer thereof impregnated in a fiber having a fiber diameter of 30 nm or less in step (1) This step is a step (1) in which the fiber diameter is 30 nm. This is a step of curing a composition containing silsesquioxane or a composition containing a silsesquioxane polymer impregnated in the following fibers by applying treatments such as pressurization, heating and photocuring.

(Heat curing)
The temperature and time for heat curing can be appropriately set according to the polymerizable functional group of the silsesquioxane used. When heating, the polymer is not completely cured but in a semi-cured state, that is, in a B-stage state, and then heated and cured while being pressed with a press to obtain a molded body with a smoother surface. it can. In this case, the pressure is usually preferably 0.1 to 2.0 MPa, more preferably 0.2 to 1.0 MPa.

  Heating is preferably performed stepwise while gradually raising the temperature. This is because rapid heating accumulates internal strain of the fiber composite. Specifically, for example, a method of sequentially heating at 80 ° C. for 1 hour, 120 ° C. for 1 hour, and 160 ° C. for 1 hour is preferable.

  When the composition containing the silsesquioxane or the composition containing the polymer does not contain an organic solvent, the composition containing the silsesquioxane or the polymer thereof using a press machine or the like as in Example 1 described later. Can be adhered to fibers having a fiber diameter of 30 nm or less, heated to melt the composition, and impregnated into the fibers. In this case, impregnation and thermosetting can be achieved simultaneously. In this case, the heating condition is preferably, for example, 40 to 100 ° C. and 0.1 to 1 hour.

(Light curing)
In addition, depending on the type of polymerizable functional group possessed by silsesquioxane, a curing reaction is caused by photocuring by adding a polymerization initiator (photoacid generator) to the composition containing silsesquioxane or a polymer thereof. be able to.

  The content of the photoacid generator in the composition containing the silsesquioxane or the composition containing the silsesquioxane polymer is from 0.0001 to 0.01 in a mass ratio to the mass of the silsesquioxane or the polymer. Is preferable, and 0.001 to 0.01 is more preferable.

The photocuring is preferably performed by exposing light having a wavelength of 100 to 400 nm. Examples of light having a wavelength of 100 to 400 nm include light of various wavelengths generated by a radiation generator, for example, ultraviolet light such as g-line and i-line, far-ultraviolet light (248 nm, 198 nm), and electron beam. . The exposure amount is preferably, for example, 10 to 2000 mJ / cm ² .

  The fiber composite of the present invention has high transparency, a small linear expansion coefficient, and is lightweight, so that it can be used for various substrates. Examples of the substrate include a liquid crystal display device substrate, an organic EL display device substrate, a color filter substrate, a solar cell substrate, a touch panel substrate, and a plasma display substrate. Alternatively, the fiber composite of the present invention may be formed on a substrate such as a glass substrate, a plastic substrate, a film substrate, or a metal substrate to form a substrate.

  The present invention will be described in more detail based on examples. The present invention is not limited to the following examples.

  The weight average molecular weight of the silsesquioxane polymer was measured by gel permeation chromatography (GPC). Specifically, it is diluted with tetrahydrofuran (THF) so that the concentration of the silsesquioxane polymer is about 0.05 to 0.10% by mass, and columns KF-805L and KF- manufactured by Showa Denko KK Using 804L, THF was measured as a developing agent, and it was determined by converting to standard polymethyl methacrylate.

[Synthesis Example 1]
<Production of Compound (II)>
Compound (II) was produced by the following route.

First stage: Production of 3-allyloxymethyl-3-ethyl-oxetane 50% by weight aqueous potassium hydroxide solution in a 2.0 liter reaction vessel equipped with a thermometer, dropping funnel and reflux condenser under nitrogen atmosphere (2500 g), 3-ethyl-3-hydroxymethyloxetane (580 g, 50 mol) and tetrabutylammonium bromide (50 g) were added, and allyl bromide (1210 g, 100 mol) was added dropwise from the dropping funnel while stirring. After completion of the dropwise addition, the mixture was stirred at room temperature for 24 hours, water was added, and the mixture was extracted with hexane. The organic layer was washed with water and dried over anhydrous magnesium sulfate. Then, the solvent was distilled off by concentration under reduced pressure, followed by distillation under reduced pressure, and 780 g (yield 89%) of 3-allyloxymethyl-3-ethyl-oxetane was obtained from a fraction having a pressure of 1.4 kPa and a tower top temperature of 76 ° C.

Second Stage: Production of Compound (II) Compound (II) was synthesized according to the method disclosed in International Publication No. 2004/024741. That is, in a nitrogen atmosphere, compound (I) (400 g) and toluene (620 g) were charged into a 2.0 liter reaction vessel equipped with a thermometer, a dropping funnel and a reflux condenser, and stirred with a magnetic stirrer. The solution was heated to 80 ° C. Pt catalyst [manufactured by Umicore Precious Metal Co., Ltd., product name Pt-VTSC-3.0X (platinum 3 mass% xylene solution)] (80 μL) was added with a microsyringe, and then 3-allyloxy produced in the first stage. Methyl-3-ethyl-oxetane (288 g) was added. And after stirring at reflux temperature for 3 hours, after cooling to room temperature, the product name SH silica (2.0g) by Fuji Silysia Chemical Co., Ltd. was added, and it stirred for 1 hour. The filtrate obtained by filtering SH silica was concentrated with an evaporator. Methanol (3000 g) was added to the obtained concentrate, activated carbon (18 g) was further added, and the mixture was stirred at room temperature for 1 hour. The filtrate from which the activated carbon was removed by filtration was concentrated with an evaporator to obtain 595 g of a colorless viscous liquid. As a result of ¹ H NMR measurement, it was found to be compound (II) (yield 83%).

[Preparation of chitin fiber]
20 g of dried chitin powder derived from crab shells (chitin (powder) manufactured by Nacalai Tesque, product code 07946-62) is dispersed in 2 liters of pure water, 10 g of acetic acid is added, and the mixture is stirred for about 1 hour at room temperature and chitin fiber A dispersion was prepared. Then, the chitin fiber in the obtained chitin fiber dispersion was defibrated for 1 hour using a stone mill grinder (Supermass colloider, manufactured by Masuko Sangyo Co., Ltd.) to obtain a chitin fiber suspension. The rotational speed of the grindstone during defibration was 1500 rpm. The chitin fiber after the defibrating treatment was observed with a field emission electron microscope, and a photograph was taken. Fifty chitin fibers in the photograph were selected at random, the fiber diameter was measured, and the minimum and maximum fiber diameters were determined. As a result, it was found that the obtained chitin fiber had a fiber diameter in the range of 10 to 20 nm. It was also confirmed that the nanofiber was uniform and had a high aspect ratio.

[Preparation of chitin nonwoven fabric A]
The suspension of chitin fibers obtained by the above method was diluted with pure water to a chitin fiber concentration of 0.2% by mass, and stirred at 25 ° C. for 3 hours at 300 rpm. A filter made by Advantech was used, and a 0.1 μm PTFE membrane filter made by Advantech was placed on the metal mesh filter. 15 g of a chitin fiber suspension that had been sufficiently stirred from above was poured and filtered under reduced pressure. Before the water was completely removed, 5 g of pure water was added, and the vacuum filtration operation was again performed twice. Thereafter, 5 g of ethanol is added, and the vacuum filtration operation is again performed twice. A deposit of chitin fibers was obtained on the PTFE membrane filter. This chitin fiber deposit was sandwiched between filter papers and dried at 90 ° C. for 6 hours under a load of 2 kg to obtain a 40 μm thick chitin nonwoven fabric A. The specific volume of the chitin nonwoven fabric A was 2 cm ³ / g.

[Preparation of chitin nonwoven fabric B]
The chitin fiber nonwoven fabric A was further dried at 110 ° C. for 4 hours, and the resulting product was designated as chitin nonwoven fabric B. The thickness of the chitin nonwoven fabric B was 40 μm, and the specific volume was 2 cm ³ / g.

Main materials used in this example: Silsesquioxane: Compound (II) produced in Synthesis Example 1
Fiber having a fiber diameter of 30 nm or less: chitin nonwoven fabric A or chitin nonwoven fabric B
Polymerization initiator: Cationic polymerization initiator (trade name Sun-Aid SI-100, manufactured by Sanshin Chemical Industry Co., Ltd.)

Example 1
A container is charged with Compound (II) produced in Synthesis Example 1 (100 parts by mass) and a cationic polymerization initiator (0.5 parts by mass) dissolved in ethylene glycol dimethyl ether (5 parts by mass). Set to Shintaro Awatori (trade name) ARE-250) manufactured by Shinki Co., Ltd., mixed and degassed to obtain a composition containing silsesquioxane. This composition was coated on PET (TORAY Lumirror 100-T60, hereinafter referred to as PET) so that the coating amount was uniform, and the chitin nonwoven fabric A, the above composition, and PET were laminated in this order. Thereafter, the metal plate was impregnated for 2 hours while applying a pressure of 1 MPa to the uppermost layer of PET, taking care not to introduce bubbles.

  After impregnation, the obtained mixture was set in a heat press machine (MINI TEST PRESS-10 manufactured by Toyo Seiki Seisakusho Co., Ltd., hereinafter referred to as a press machine). Then, a pressure of 1 MPa is applied and heating is performed at 80 ° C. for 1 hour, 120 ° C. for 1 hour, and 160 ° C. for 1 hour to obtain a chitin fiber composite silsesquioxane molded body having a thickness of 55 μm as a fiber composite. It was.

(Example 2)
A container is charged with Compound (II) produced in Synthesis Example 1 (50 parts by mass) and a cationic polymerization initiator (0.5 parts by mass) dissolved in ethylene glycol dimethyl ether (50 parts by mass). Set to Shintaro Awatori (trade name) ARE-250) manufactured by Shinki Co., Ltd., mixed and degassed to obtain a composition containing silsesquioxane. This composition was impregnated with chitin nonwoven fabric A for 5 minutes to obtain a mixture. The resulting mixture was heated at 80 ° C. for 1 hour, 120 ° C. for 1 hour, and 160 ° C. for 1 hour to obtain a chitin fiber composite silsesquioxane molded body having a thickness of 80 μm as a fiber composite.

(Example 3)
The same procedure as in Example 2 was carried out except that the compound (II) produced in Synthesis Example 1 (80 parts by mass), ethylene glycol dimethyl ether (20 parts by mass), and a cationic polymerization initiator (0.5 parts by mass) were charged in a container. Thus, a chitin fiber composite silsesquioxane molded body having a thickness of 130 μm was obtained as a fiber composite.

Example 4
Using chitin nonwoven fabric B, a chitin fiber composite silsesquioxane molded body having a thickness of 80 μm was obtained as a fiber composite in the same manner as in Example 2.

(Example 5)
Using chitin nonwoven fabric B, a chitin fiber composite silsesquioxane molded body having a thickness of 130 μm was obtained as a fiber composite in the same manner as in Example 3.

(Comparative Example 1)
A silsesquioxane film having a thickness of 50 μm was obtained as a fiber composite in the same manner as in Example 1 except that chitin nonwoven fabric A was not used.

(Comparative Example 2)
The physical properties of chitin nonwoven fabric A were evaluated.

(Comparative Example 3)
The physical properties of chitin nonwoven fabric B were evaluated.

<Chitin fiber content>
The chitin fiber content was measured by measuring the mass of the material before and after the composite.

<Total light transmittance / turbidity measurement>
The total light transmittance and turbidity of the silsesquioxane molded bodies obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were measured with a haze meter (NHD5000 manufactured by Nippon Denshoku Industries Co., Ltd.). The results are shown in Table 1. When the total light transmittance was 70 to 95% and the turbidity was 1 to 30, it was judged that the transparency was high.

<Linear expansion coefficient>
The silsesquioxane molded bodies obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were cut into a width of 3 mm and a length of 15 mm, and a thermomechanical analyzer (TMA-100) manufactured by Seiko Electronics Industry Co., Ltd. was used. The linear expansion coefficient was calculated in the range of 100 to 150 ° C. at a distance of 10 mm between chucks and a load of 0.1 g at 10 ° C./min. The results are shown in Table 1.

<Evaluation of flexibility>
When the 180 ° bending test was performed so that the short side and the short side of the samples of the silsesquioxane molded bodies obtained from Examples 1 to 5 and Comparative Examples 1 and 2 were combined, none of the samples was broken. It was flexible and could be bent freely.

  As can be seen from the results shown in Table 1, according to the present invention, the silsesquioxane molded bodies of Examples 1 to 5 complexed with chitin fibers reduce the linear expansion coefficient while maintaining high transparency. I was able to. Furthermore, since it did not crack even if it bent | folded at 180 degrees, it turned out that flexibility is high.

  On the other hand, Comparative Example 1 that was not complexed with chitin fibers had a high linear expansion coefficient although it had a high total light transmittance. Moreover, since the comparative example 2 which is the chitin nonwoven fabric A and the comparative example 3 which is the chitin nonwoven fabric B do not contain silsesquioxane, the total light transmittance and turbidity were large.

  From these results, it was expected that the fiber composite of the present invention can be suitably used for a liquid crystal display element substrate, an organic EL display element substrate, a color filter substrate, and a solar cell substrate.

  The fiber composite of the present invention can be suitably used for liquid crystal display element substrates, organic EL display element substrates, color filter substrates, solar cell substrates, touch panel substrates, plasma display substrates, and the like.

Claims (22)

  A fiber composite obtained by curing a mixture comprising a fiber having a fiber diameter of 30 nm or less and a composition containing silsesquioxane or a silsesquioxane polymer.   The fiber composite according to claim 1, wherein the fiber is chitin fiber.   The fiber composite according to claim 2, wherein the chitin fiber is a chitin nonwoven fabric.   The fiber composite according to any one of claims 1 to 3, wherein the silsesquioxane is a silsesquioxane having a cage type or partial cage type structure. The fiber composite according to claim 4, wherein the silsesquioxane having the cage type or partial cage type structure is at least one selected from the compounds represented by the general formulas (A-1) to (A-3). body.

In the general formulas (A-1) to (A-3), each R is independently hydrogen, any hydrogen may be replaced with fluorine, and —CH ₂ — not adjacent to each other is —O— or cycloalkylene. The alkyl having 1 to 45 carbon atoms which may be substituted with, cycloalkyl having 4 to 8 carbon atoms, alkyl having 1 to 10 carbon atoms, or aryl optionally substituted with halogen. R ¹ is a group independently selected from alkyl having 1 to 4 carbon atoms, cyclopentyl, cyclohexyl and phenyl. At least one X is hydrogen, a vinyl group, or a polymerizable functional group having 1 to 10 carbon atoms, alkyl, cycloalkyl, or phenyl, and the remaining X is a group defined as in R ¹ It is.   The fiber according to claim 5, wherein in the general formulas (A-1) to (A-3), the polymerizable functional group is oxiranyl, 3,4-epoxycyclohexyl, oxetanyl, acrylic, or (meth) acrylic. Complex.   The fiber composite according to any one of claims 1 to 6, wherein a linear expansion coefficient is 120 ppm / K or less. A method for producing a fiber composite of a fiber having a fiber diameter of 30 nm or less and silsesquioxane, comprising the following steps (1) and (2).
(1) A step of impregnating a fiber having a fiber diameter of 30 nm or less with a composition containing silsesquioxane or a polymer thereof (2) The silsesquioxane impregnated in the fiber in step (1) or the A step of curing reaction of a composition containing a polymer   The manufacturing method according to claim 8, wherein the fibers are chitin fibers.   The manufacturing method according to claim 9, wherein the chitin fiber is a chitin nonwoven fabric. The method according to any one of claims 8 to 10, wherein the silsesquioxane is at least one selected from the compounds represented by the general formulas (A-1) to (A-3).

In the general formulas (A-1) to (A-3), each R is independently hydrogen, any hydrogen may be replaced with fluorine, and —CH ₂ — not adjacent to each other is —O— or cycloalkylene. The alkyl having 1 to 45 carbon atoms which may be substituted with, cycloalkyl having 4 to 8 carbon atoms, alkyl having 1 to 10 carbon atoms, or aryl optionally substituted with halogen. R ¹ is a group independently selected from alkyl having 1 to 4 carbon atoms, cyclopentyl, cyclohexyl and phenyl. At least one X is hydrogen, a vinyl group, or a polymerizable functional group having 1 to 10 carbon atoms, alkyl, cycloalkyl, or phenyl, and the remaining X is a group defined as in R ¹ It is.   The production according to claim 11, wherein in the general formulas (A-1) to (A-3), the polymerizable functional group is oxiranyl, 3,4-epoxycyclohexyl, oxetanyl, acrylic, or (meth) acrylic. Method.   The manufacturing method of any one of Claims 8-12 whose weight average molecular weights of the said polymer are 3,000-4,000,000.   The manufacturing method according to any one of claims 8 to 13, wherein in the step (1), the composition contains a polymerization initiator.   The production method according to claim 14, wherein the polymerization initiator is a cationic polymerization initiator or a radical polymerization initiator.   The manufacturing method according to claim 14 or 15, wherein in the step (1), the composition contains a curing agent.   The manufacturing method according to claim 16, wherein the curing agent is an acid anhydride or an amine.   In the said process (2), hardening reaction is a thermosetting reaction, The manufacturing method of any one of Claims 8-17.   In the said process (2), hardening reaction is photocuring reaction, The manufacturing method of any one of Claims 8-15.   The manufacturing method according to any one of claims 8 to 19, wherein the composition further contains an epoxy resin or an oxetane resin.   The fiber composite manufactured by the manufacturing method of any one of Claims 8-20.   A substrate using the fiber composite according to any one of claims 1 to 7 and 21.