Polysilsesquioxane-based liquid precursor, cured product, and method for producing same

Abstract

Provided are: a method for producing a thick polysilsesquioxane-based cured product having high hardness and excellent transparency; a polysilsesquioxane-based liquid precursor for obtaining such a cured product; and a cured product. The polysilsesquioxane-based liquid precursor according to the present invention contains a copolymer of a trifunctional alkoxy silicon and a bifunctional alkoxy silicon, wherein the fraction of residual silanol groups (fSiOH) in the copolymer is 0.02 to 0.3.

Description

TECHNICAL FIELD

[0001] The present application relates to polysilsesquioxane-based liquid precursors and cured products, and methods for producing the same. BACKGROUND

[0002] Silicon-based organic-inorganic hybrid materials contain silicon (Si) as a backbone element. Silicon (Si) has 4 bonding bonds, and exhibits various properties by the atoms, functional groups bonded thereto. Oxygen (O) and carbon (C) are firmly bonded to Si. Oxygen bridges Si atoms to each other by forming Si-O-Si bonds, forming a polymer. On the other hand, carbon has an action of inhibiting the formation of Si-O-Si bonds. Such silicon-based organic-inorganic hybrid materials are excellent in heat resistance, chemical durability, transparency, electrical insulation, and the like, and are thus used for optical materials or electronic materials.

[0003] Polysilsesquioxane contains a silsesquioxane skeleton represented by the general formula RSiO 3 / 2 (R is an organic functional group) per 1 Si atom. Polysilsesquioxane exhibits a random structure, a ladder structure, a cage structure, and the like, and has excellent mechanical strength, chemical stability, and thermal stability.

[0004] Polysilsesquioxane is obtained by subjecting a tri-functional hydrocarbyloxysilane to hydrolysis and condensation reaction. In order to synthesize polysilsesquioxane, various synthesis methods have been studied in the past.

[0005] For example, in Patent Literature 1, a method for producing a polysilsesquioxane liquid is proposed, which comprises subjecting a mixture containing a tri-functional hydrocarbyloxysilane, water, and an acid catalyst to hydrolysis and condensation without using an organic solvent, and then removing an alcohol produced by hydrolysis of the tri-functional hydrocarbyloxysilane. In addition, in Patent Literature 2, a polysiloxane having a weight average molecular weight (Mw1) in the range of 2000 to 20,000 in terms of polystyrene, and containing 65% by mole or more of a silicon-bonded unit T 3 2 satisfying Formula (1): T 3 2 ≥ 0.026 x Mw2 + 20 is condensed in the presence of an acid catalyst or without a catalyst at a concentration of 5 to 40 mass% to produce a polymethylsilsesquioxane having a weight average molecular weight (Mw1) in the range of 2000 to 20,000 in terms of polystyrene, and containing 65% by mole or more of a silicon-bonded unit T 3 1 (here, T 3 1 refers to a silicon-bonded unit in which all of the 3 oxygen atoms bonded to a silicon atom are bonded to other silicon atoms) is disclosed.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: Japanese Patent Application Laid-Open No. 2013-253223

[0009] Patent Literature 2: Japanese Patent Application Laid-Open No. 2018-178011 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] The properties of the polysilsequioxane known heretofore do not have sufficiently satisfactory performance, and further improvement and development are desired. In addition, in the case where a liquid precursor of polysilsequioxane is thermally cured without using an additive, a curing catalyst, or the like, it is difficult to produce a thick cured product using the conventional production method, and it is difficult to obtain a cured product having a thickness of 5 mm or more.

[0012] Therefore, an object of the present application is to provide a method for producing a cured product of polysilsequioxane having high hardness and excellent transparency, and having a thickness, without using an additive, a curing catalyst, or the like, and to provide a liquid precursor of polysilsequioxane and a cured product for obtaining such a cured product.

[0013] MEANS FOR SOLVING THE PROBLEMS

[0014] One embodiment of the present application relates to a liquid precursor of polysilsequioxane, which contains a copolymer of a trifunctional hydroxyalkylsilane and a difunctional hydroxyalkylsilane, wherein the fraction f of residual silanol groups in the copolymer is 0.02 to 0.3. SiOH

[0015] In addition, another embodiment of the present application relates to a cured product, which is a cured product of a copolymer of a trifunctional hydroxyalkylsilane and a difunctional hydroxyalkylsilane, wherein the fraction f of residual silanol groups in the copolymer is 0.02 to 0.3. SiOH

[0016] In addition, another embodiment of the present application relates to a method for producing a liquid precursor of polysilsequioxane, wherein a trifunctional hydroxyalkylsilane and a difunctional hydroxyalkylsilane are allowed to mature in the presence of an acid catalyst in an aqueous solution without using an organic solvent, while allowing them to undergo a hydrolysis reaction and a polycondensation reaction.

[0017] In addition, another embodiment of the present application relates to a method for producing a cured product, wherein a liquid precursor of polysilsequioxane obtained by the above-described method for producing a liquid precursor of polysilsequioxane is heated to be cured.

[0018] EFFECTS OF THE INVENTION

[0019] ​​The polysilsequioxane-based liquid precursor obtained by the production method of the polysilsequioxane-based liquid precursor of the present application can obtain a cured product having high hardness and excellent transparency. Therefore, the cured product can be expected to be used for various electronic applications such as ultraviolet transparent material, transparent adhesive, sealing material, insulating film, scratch-resistant material, and the like. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 are photographic images showing the appearance of the liquid precursors produced in Test Example 1, (a) is a photographic image showing the appearance of the liquid precursor of Example 1, (b) is a photographic image showing the appearance of the liquid precursor of Example 2, (c) is a photographic image showing the appearance of the liquid precursor of Example 3, (d) is a photographic image showing the appearance of the liquid precursor of Example 4, (e) is a photographic image showing the appearance of the liquid precursor of Example 5, (f) is a photographic image showing the appearance of the liquid precursor of Example 6, (g) is a photographic image showing the appearance of the liquid precursor of Example 7, (h) is a photographic image showing the appearance of the liquid precursor of Example 8, (i) is a photographic image showing the appearance of the liquid precursor of Example 9, and (j) is a photographic image showing the appearance of the liquid precursor of Example 10.

[0021] Figure 2 are photographic images showing the appearance of the liquid precursors produced in Test Example 2, (a) is a photographic image showing the appearance of the liquid precursor of Example 11, (b) is a photographic image showing the appearance of the liquid precursor of Example 12, (c) is a photographic image showing the appearance of the liquid precursor of Example 13, (d) is a photographic image showing the appearance of the liquid precursor of Example 14, (e) is a photographic image showing the appearance of the liquid precursor of Example 15, (f) is a photographic image showing the appearance of the liquid precursor of Example 16, (g) is a photographic image showing the appearance of the liquid precursor of Example 17, (h) is a photographic image showing the appearance of the liquid precursor of Example 18, and (i) is a photographic image showing the appearance of the liquid precursor of Example 19.

[0022] Figure 3 are graphs showing the change in viscosity of the liquid precursors in Test Example 3, (a) is a graph showing the change in viscosity of the liquid precursors of Examples 12 to 14, and (b) is a graph showing the change in viscosity of the liquid precursors of Examples 17 to 19.

[0023] Figure 4 are photographic images showing the appearance of the liquid precursors produced in Test Example 4, (a) is a photographic image showing the appearance of the liquid precursor of Example 20, (b) is a photographic image showing the appearance of the liquid precursor of Example 21, (c) is a photographic image showing the appearance of the liquid precursor of Example 22, (d) is a photographic image showing the appearance of the liquid precursor of Example 23, and (e) is a photographic image showing the appearance of the liquid precursor of Example 24.

[0024] Figure 5 are photographic images showing the appearance of the cured products produced in Test Example 5, (a) is a photographic image showing the appearance of the cured product of Example 25, and (b) is a photographic image showing the appearance of the cured product of Example 26.

[0025] Figure 6 is a photograph showing the appearance of the cured product produced in Test Example 5, (a) is a photograph showing the appearance of the cured product of Example 27, (b) is a photograph showing the appearance of the cured product of Example 28, (c) is a photograph showing the appearance of the cured product of Example 29, (d) is a photograph showing the appearance of the cured product of Example 30, and (e) is a photograph showing the appearance of the cured product of Example 31.

[0026] Figure 7 is a photograph showing the appearance of the cured product produced in Test Example 5, (a) is a photograph showing the appearance of the cured product of Example 27, (b) is a photograph showing the appearance of the cured product of Example 28, (c) is a photograph showing the appearance of the cured product of Example 29, (d) is a photograph showing the appearance of the cured product of Example 30, and (e) is a photograph showing the appearance of the cured product of Example 31.

[0027] Figure 8 is a graph showing the stress-strain curve recorded in the uniaxial loading and unloading test of Test Example 6. DETAILED DESCRIPTION

[0028] Hereinafter, the present application will be described, but the present application is not limited by the examples in the following description.

[0029] (Polysilsesquioxane-based liquid precursor)

[0030] The polysilsesquioxane-based liquid precursor of the present application contains a copolymer of a trifunctional hydrocarbyloxysilane and a difunctional hydrocarbyloxysilane, the fraction f of residual silanol groups in the copolymer being 0.02 to 0.3. SiOH is 0.02 to 0.3.

[0031] According to the polysilsesquioxane-based liquid precursor having such a feature, a cured product having both elasticity and high hardness can be obtained. In addition, the polysilsesquioxane-based liquid precursor of the present application can maintain a liquid state for a long time without gelling in room temperature storage.

[0032] The trifunctional hydrocarbyloxysilane is a compound in which three of the four bonds of silicon (Si) are bonded to a hydrocarbyloxy group.

[0033] As the trifunctional hydrocarbyloxysilane, for example, trimethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, propyltrimethoxysilane, phenyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, vinyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, triethoxysilane, methyltriethoxysilane, ethyltriethoxysilane, propyltriethoxysilane, phenyltriethoxysilane, 3-mercaptopropyltriethoxysilane, vinyltriethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-aminopropyltriethoxysilane, and the like can be exemplified. The trifunctional hydrocarbyloxysilane can contain one of them alone, or two or more.

[0034] The tri-functional hydrocarbyloxysilane is preferably at least one selected from the group consisting of methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane, and ethyltriethoxysilane, more preferably methyltrimethoxysilane, further preferably contains 80 mol% or more of methyltrimethoxysilane relative to the total moles of the tri-functional hydrocarbyloxysilane, particularly preferably contains 95 mol% or more of methyltrimethoxysilane relative to the total moles of the tri-functional hydrocarbyloxysilane.

[0035] The di-functional hydrocarbyloxysilane is a compound in which 2 of the 4 bonds of silicon are bonded to a hydrocarbyloxy group.

[0036] As the di-functional hydrocarbyloxysilane, for example, dimethoxysilane, dimethoxymethylsilane, dimethoxydimethylsilane, dimethoxyethylsilane, dimethoxydiethylsilane, dimethoxyethylmethylsilane, dimethoxyphenylsilane, dimethoxymethylphenylsilane, dimethoxydiphenylsilane, dimethoxyvinylsilane, dimethoxymethylvinylsilane, dimethoxydivinylsilane, diethoxysilane, diethoxymethylsilane, diethoxydimethylsilane, diethoxyethylsilane, diethoxydiethylsilane, diethoxyethylmethylsilane, diethoxyphenylsilane, diethoxymethylphenylsilane, diethoxydiphenylsilane, diethoxyvinylsilane, diethoxymethylvinylsilane, diethoxydivinylsilane, and the like can be exemplified. The di-functional hydrocarbyloxysilane can contain one of them alone or 2 or more.

[0037] The di-functional hydrocarbyloxysilane is preferably at least one selected from the group consisting of dimethoxydimethylsilane, dimethoxyethylmethylsilane, dimethoxydiethylsilane, diethoxydimethylsilane, diethoxyethylmethylsilane, and diethoxydiethylsilane, more preferably dimethoxydimethylsilane, further preferably contains 80 mol% or more of dimethoxydimethylsilane relative to the total moles of the di-functional hydrocarbyloxysilane, particularly preferably contains 95 mol% or more of dimethoxydimethylsilane relative to the total moles of the di-functional hydrocarbyloxysilane.

[0038] In the present specification, the structural unit derived from the tri-functional hydrocarbyloxysilane in the copolymer is referred to as "T type", and the T type is classified into 3 types according to the number of bridging oxygen atoms bonded to other silicon atoms. In the case where all of the 3 oxygen atoms are bonded to other silicon atoms, i.e., in the case where the bridging oxygen is 3, the structural unit is referred to as "T 3 type", in the case where 2 of the 3 oxygen atoms are bonded to other silicon atoms, i.e., in the case where the bridging oxygen is 2, the structural unit is referred to as "T 2 type", and in the case where 1 of the 3 oxygen atoms is bonded to other silicon atoms, i.e., in the case where the bridging oxygen is 1, the structural unit is referred to as "T 1"Type D".

[0039] Further, a structural unit derived from a difunctional hydrocarbyloxysilane in the copolymer is referred to as "Type D", and Type D is classified into 2 depending on the number of bridging oxygen atoms bonded to other silicon atoms. In the case where all of the oxygen atoms among the 2 oxygen atoms are bonded to other silicon atoms, that is, in the case where the bridging oxygen is 2, the structural unit is referred to as "Type D 2 1 In the case where 1 of the oxygen atoms among the 2 oxygen atoms is bonded to other silicon atoms, that is, in the case where the bridging oxygen is 1, the structural unit is referred to as "Type D

[0040] In the polysilsesquioxane-based liquid precursor of the present embodiment, the ratio of the bridging oxygen of the copolymer is found by the following formula (1).

[0041] Ratio of bridging oxygen = 100 x (number of bridging oxygen atoms in copolymer) / (total number of oxygen atoms in copolymer) <m> / <m> max ……(1)

[0042] In formula (1), <m> max all of the structural units derived from the tri-functional hydrocarbyloxysilane are T structural units having 3 bridging oxygen atoms 3 all of the structural units derived from the di-functional hydrocarbyloxysilane are D structural units having 2 bridging oxygen atoms 2 the maximum average number of bridging oxygen atoms in a perfect copolymer when all of the structural units derived from the tri-functional hydrocarbyloxysilane are T <m>The average bridging oxygen number actually contained in the copolymer represented by the following formula (2).

[0043] <m>= (f T1 × n T1 ) + (f T2 × n T2 ) + (f T3 × n T3 ) + (f D1 × n D1 ) + (f D2 × n D2 ) ……(2)

[0044] In formula (2), f T1 is the existence ratio of T 1 type structural units having 1 bridging oxygen among the structural units derived from the tri-functional hydrocarbyloxysilane, n T1 represents 1, which is the number of bridging oxygen of the T 1 type structural units, f T2 is the existence ratio of T 2 type structural units having 2 bridging oxygens among the structural units derived from the tri-functional hydrocarbyloxysilane, n T2 represents 2, which is the number of bridging oxygen of the T 2 type structural units, f T3 is the existence ratio of T 3 type structural units having 3 bridging oxygens among the structural units derived from the tri-functional hydrocarbyloxysilane, n T3 represents 3, which is the number of bridging oxygen of the T 3 type structural units, f D1 is the existence ratio of D 1 type structural units having 1 bridging oxygen among the structural units derived from the di-functional hydrocarbyloxysilane, n D1 represents 1, which is the number of bridging oxygen of the D 1 type structural units, f D2 is the existence ratio of D 2 type structural units having 2 bridging oxygens among the structural units derived from the di-functional hydrocarbyloxysilane, n D2 represents 2, which is the number of bridging oxygen of the D 2 type structural units, The following relationships exist among f T1 , f T2 , f T3 , f D1 , and f D2 .

[0045] f T1 +f T2 +f T3 +f D1 +f D2 =1

[0046] It should be noted that T 1 The ratio of the presence of structural units f T1 T 2 The ratio of the presence of structural units f T2 T 3 The ratio of the presence of structural units f T3 D 1 Type structural unit existence ratio f D1 and D 2 The ratio of the presence of structural units f D2 By measurement 29 The Si NMR spectrum was obtained by calculating the respective ratios based on the results.

[0047] In the polysilsesquioxane liquid precursor of this embodiment, the residual silanol group fraction f in the copolymer is... SiOH It ranges from 0.02 to 0.3.

[0048] Residual silanol group fraction f SiOH The total number of SiOH groups present in the copolymer of trifunctional and difunctional silicon relative to the total number of Si atoms is... <m> max The ratio of the product. When the residual silanol group fraction f SiOH When the concentration is above 0.02, curing based on polycondensation reaction during thermosetting is easier, thus yielding cured products with high hardness. When the residual silanol group fraction f... SiOH When the concentration is below 0.3, the stability of the liquid precursor can be maintained.

[0049] Residual silanol fraction f SiOH Preferably, it is 0.03 or more, more preferably 0.05 or more, even more preferably 0.06 or more, particularly preferably 0.1 or more, and even more preferably 0.25 or less, even more preferably 0.2 or less.

[0050] Regarding the residual silanol group fraction f SiOH ,according to 1 H NMR spectroscopy determined the residual methoxy fraction. SiOMe It can be obtained by the following formula (3).

[0051] Residual silanol group fraction f SiOH =1-( <m> / <m> max +f SiOMe ) ……(3)

[0052] In formula (3), <m>for the average number of bridging oxygen actually contained in the copolymer, <m> max the maximum average bridging oxygen number in the total copolymer, <m> / <m> max The ratio of bridging oxygen that is a copolymer.

[0053] The polysiloxane-based liquid precursor of the present embodiment preferably has a viscosity of 1 x 10 6 mPa-s or less at 40°C. When the viscosity is 1 x 10 6 mPa-s or less, the operability is excellent, and the removal of bubbles, the molding of the precursor, and the like are easy, and loss due to adhesion to a container can be suppressed.

[0054] The viscosity is more preferably 1 x 10 5 mPa-s or less, and the lower the viscosity, the more preferable, and thus the lower limit is not particularly limited.

[0055] The viscosity is measured at 40°C, for example, using a commercially available viscometer (for example, EMS viscometer "EMS-1000S" manufactured by Kyoto Electronics Manufacturing Co., Ltd.).

[0056] The polysiloxane-based liquid precursor of the present embodiment preferably has a mass average molar mass (weight average molecular weight) Mm of 0.5 x 10 3 g-mol -1 to 50 x 10 3 g-mol -1 . The mass average molar mass Mm is more preferably 0.8 x 10 3 g-mol -1 or more, and further preferably 1.0 x 10 3 g-mol -1 or more. In addition, more preferably, it is 20 x 10 3 g-mol -1 or more, further preferably 15 x 10 3 g-mol -1 or more, and particularly preferably 10 x 10 3 g-mol -1 or more.

[0057] In addition, the polysiloxane-based liquid precursor preferably has a number average molar mass (number average molecular weight) Mn of 0.5 x 10 3 g-mol -1 to 5.0 x 10 3 g-mol -1 . The number average molar mass Mn is more preferably 0.7 x 10 3 g-mol -1 or more, and further preferably 0.8 x 10 3 g-mol -1 or more. In addition, more preferably, it is 4.0 x 10 3 g-mol -1 Further, it is further preferred that 3.0 x 10 3 g-mol -1 Further, it is further preferred that 3.0 x 10

[0058] The mass average molar mass Mm and the number average molar mass Mn are obtained by a publicly known measurement method such as gel permeation chromatography.

[0059] (Cured product)

[0060] The cured product of the present application is a cured product of a copolymer of a tri-functional hydrocarbyloxysilane and a di-functional hydrocarbyloxysilane, the fraction f of residual silanol groups in the copolymer being 0.02 to 0.3. SiOH The cured product of the present application is a cured product of a polysiloxane-based liquid precursor obtained by curing the above polysiloxane-based liquid precursor.

[0061] The tri-functional hydrocarbyloxysilane and the di-functional hydrocarbyloxysilane used for the cured product are as described above, and the preferred substances are also the same. Further, the properties of the polysiloxane-based liquid precursor are also as described above.

[0062] The pencil hardness of the cured product of the present embodiment is preferably HB or more. When the pencil hardness is HB or more, the cured product is hard and has excellent hardness. The pencil hardness is more preferably H or more, further preferably 2H or more, particularly preferably 4H or more, and most preferably 6H or more.

[0063] Note that the pencil hardness is measured by the hand scratch method according to the pencil scratch test described in the old JIS K 5400.

[0064] Further, the Vickers hardness of the cured product measured according to JIS R 1610-2003 is preferably 1 HV or more. It is known that when the Vickers hardness is 1 HV or more, high hardness is possessed while having elasticity.

[0065] The Vickers hardness is more preferably 2 HV or more, and further preferably 4 HV or more.

[0066] Note that the cured product of the present embodiment exhibits a remarkable elastic recovery behavior as shown in the uniaxial loading and unloading test in the examples described later, and thus depending on the cured product, sometimes no deformation mark is formed by the Vickers hardness test, and the Vickers hardness cannot be measured. In the case where a deformation mark is formed by the Vickers hardness tester, it can be said that sufficient hardness is possessed as a cured product, but in the case where the Vickers hardness cannot be measured, the hardness can be measured by the pencil hardness test.

[0067] Further, the cured product of the present embodiment has high transparency. The ultraviolet absorption end wavelength of the cured product is preferably 250 nm or less. When the ultraviolet absorption end wavelength is 250 nm or less, excellent visible-ultraviolet transmittance is exhibited, and thus high ultraviolet resistance can be expected.

[0068] The ultraviolet absorption end wavelength is more preferably 220 nm or less, further preferably 210 nm or less, and particularly preferably 200 nm or less.

[0069] The ultraviolet absorption end wavelength is a value obtained as an intersection of an approximate straight line of a spectral region of an ultraviolet absorption end region of an optical absorption spectrum measured using a spectrophotometer (U-4100 manufactured by Hitachi High-Technologies Corporation) and an approximate straight line of a baseline spectrum of a transparent region on the long wavelength side.

[0070] In addition, the cured product of the present embodiment can have a thickness of 4.8 mm or more, preferably 5 mm or more, more preferably 8 mm or more, and further preferably 10 mm or more. In particular, when the cured product has a thickness of 10 mm or more, it can be used as a block material and applied to a large member.

[0071] (Method for producing)

[0072] The polyhedral silsesquioxane-based liquid precursor can be obtained by a method comprising subjecting a tri-functional hydroxysilane and a di-functional hydroxysilane to hydrolysis and condensation reactions in the presence of an acid catalyst in an aqueous solution without using an organic solvent, and aging.

[0073] The tri-functional hydroxysilane and the di-functional hydroxysilane, which can be used in the production method of the present application, are as described above, and the preferred substances are also the same.

[0074] The tri-functional hydroxysilane is preferably used in a range of 0.5 mol to 0.99 mol per 1 mol of the total hydroxysilane. When the amount of the tri-functional hydroxysilane used is in the above range, the obtained cured product can have both elasticity and increased hardness.

[0075] The amount of the tri-functional hydroxysilane used is more preferably 0.6 mol or more, further preferably 0.7 mol or more, and still more preferably 0.95 mol or less, and further preferably 0.9 mol or less, per 1 mol of the total hydroxysilane.

[0076] The di-functional hydroxysilane is preferably used in a range of 0.01 mol to 0.5 mol per 1 mol of the total hydroxysilane. When the amount of the di-functional hydroxysilane used is in the above range, the obtained cured product can have both elasticity and increased hardness.

[0077] The amount of the di-functional hydroxysilane used is more preferably 0.05 mol or more, further preferably 0.1 mol or more, and still more preferably 0.4 mol or less, and further preferably 0.3 mol or less, per 1 mol of the total hydroxysilane.

[0078] As the acid catalyst, nitric acid, hydrochloric acid, sulfuric acid, acetic acid, formic acid and the like used in the conventional sol-gel method using an organic solvent can be preferably used, and from the viewpoints of easiness of obtaining, high purity, volatility, and ultraviolet transparency, hydrochloric acid is preferred.

[0079] Note that phosphoric acid can also be used as the acid catalyst, but since phosphoric acid is highly nonvolatile and tends to remain in the copolymer, it is preferred that phosphoric acid not be used.

[0080] The amount of the acid catalyst used varies depending on the kind or composition of the hydrocarbyloxysilane used, the kind of the acid, and the like, and relative to 1 mole of the total of the tri-functional hydrocarbyloxysilane and the di-functional hydrocarbyloxysilane, the acid catalyst is preferably mixed in an amount of more than 0 mole and 0.01 mole or less. When the acid catalyst is 0.01 mole or less relative to 1 mole of the total of all the hydrocarbyloxysilanes, a stable liquid precursor can be produced, and the residual amount of the acid in the liquid precursor and the cured product can be reduced.

[0081] For example, when methyltrimethoxysilane is used as the tri-functional hydrocarbyloxysilane and dimethoxydimethylsilane is used as the di-functional hydrocarbyloxysilane, relative to 1 mole of the total of all the hydrocarbyloxysilanes, the acid catalyst is preferably used in an amount in the range of 0.00002 mole to 0.002 mole, and more preferably in an amount in the range of 0.00002 mole to 0.001 mole.

[0082] In the present production method, an organic solvent is not used as the solvent, and the reaction is performed in an aqueous solution. As the water, purified water, distilled water, ion-exchanged water and the like can be exemplified.

[0083] The amount of the water used varies depending on the kind or composition of the hydrocarbyloxysilane used, the kind of the acid, and the like, and relative to 1 mole of the total of the tri-functional hydrocarbyloxysilane and the di-functional hydrocarbyloxysilane, the water is preferably mixed in an amount in the range of 1.5 moles to 50 moles. When the amount of the water used is 1.5 moles or more, the viscosity of the reaction liquid can be suppressed from increasing, and when the amount of the water used is 50 moles or less, the amount of the methanol aqueous solution produced as a byproduct can be suppressed.

[0084] For example, when methyltrimethoxysilane is used as the tri-functional hydrocarbyloxysilane and dimethoxydimethylsilane is used as the di-functional hydrocarbyloxysilane, relative to 1 mole of the total of all the hydrocarbyloxysilanes, the water is preferably used in an amount in the range of 5 moles to 50 moles, more preferably in an amount in the range of 8 moles to 40 moles, and further preferably in an amount in the range of 10 moles to 30 moles.

[0085] In the production method of the polysilsequioxane-based liquid precursor of the present embodiment, the trifunctional hydrocarbyloxysilane, difunctional hydrocarbyloxysilane, water, and acid catalyst are mixed, and hydrolysis and polycondensation are performed, at which time maturation is performed by keeping at a temperature of 20°C to 100°C for about 1 hour to about 48 hours. By performing the reaction in the above temperature range, the viscosity increase of the obtained liquid precursor can be suppressed. In addition, by performing the reaction for the above range of time, the reaction proceeds sufficiently, and the residual of unreacted hydrocarbyloxy groups can be suppressed.

[0086] The excess added water or alcohol produced at the time of hydrolysis needs to be removed. In removing the water and alcohol, methods such as drying, liquid-liquid extraction, and the like are used. In the case of performing drying, it is preferable to dry at 20°C to 100°C for 1 hour to 48 hours. When vacuum drying is used at the time of drying, the residual amount of water and alcohol can be reduced, and thus is preferable. In particular, in the production method of the present embodiment, in the case where methoxysilane is used as the silicon source, by hydrolysis and polycondensation, liquid-liquid phase separation into a phase rich in polysilsequioxane-based precursor and a phase rich in methanol and water occurs, and thus liquid-liquid extraction can be performed, and the drying time of the former can be shortened.

[0087] The obtained polysilsequioxane-based liquid precursor is cured by heating to obtain a cured product.

[0088] As the conditions of the heat treatment, there is no particular limitation, and it is preferable to perform at a temperature of 100°C to 300°C in air or in a non-active gas atmosphere such as nitrogen or under vacuum for about 1 hour to about 1 week, and further preferably in a non-active gas atmosphere such as nitrogen or under vacuum in order to improve transparency.

[0089] The heat treatment can be performed at a constant temperature, or can be performed in multiple steps at different temperatures and / or for different times.

[0090] The polysilsequioxane-based liquid precursor obtained in the present embodiment is in a liquid state, does not gel during room temperature storage, is easy to handle, the cured product obtained from the liquid precursor is high in hardness while being elastic, and exhibits excellent visible-ultraviolet light transmittance. In addition, the cured product of the present embodiment can be formed in a certain degree of thickness, and thus bulkiness is easily obtained.

[0091] The cured product of the present embodiment is suitably used for electrical / electronic component applications as an ultraviolet transparent material, a transparent adhesive for alkali-avoiding sites, an ultraviolet LED sealing material, an electrically insulating film, a scratch-resistant coating, a shock-resistant scratch-resistant cover material, and the like.

[0092] As explained above, the following matters are disclosed in the present specification.

[0093] <1> A polysilsesquioxane-based liquid precursor comprising a copolymer of a tri-functional hydrocarbyloxysilane and a di-functional hydrocarbyloxysilane, wherein a fraction f of residual silanol groups in the copolymer is 0.02 to 0.3. SiOH is 0.02 to 0.3.

[0094] <2> The polysilsesquioxane-based liquid precursor according to <1> described above, wherein a viscosity at 40°C of the polysilsesquioxane-based liquid precursor is 1 x 10 6 mPa-s or less.

[0095] <3> The polysilsesquioxane-based liquid precursor according to <1> or <2> described above, wherein the tri-functional hydrocarbyloxysilane comprises 80 mol% or more of methyltrimethoxysilane with respect to the total mol% of the tri-functional hydrocarbyloxysilane.

[0096] <4> The polysilsesquioxane-based liquid precursor according to any one of <1> to <3> described above, wherein the di-functional hydrocarbyloxysilane comprises 80 mol% or more of dimethoxydimethylsilane with respect to the total mol% of the di-functional hydrocarbyloxysilane.

[0097] <5> A cured product of a copolymer of a tri-functional hydrocarbyloxysilane and a di-functional hydrocarbyloxysilane, wherein a fraction f of residual silanol groups in the copolymer is 0.02 to 0.3. SiOH is 0.02 to 0.3.

[0098] <6> The cured product according to <5> described above, wherein the tri-functional hydrocarbyloxysilane comprises 80 mol% or more of methyltrimethoxysilane with respect to the total mol% of the tri-functional hydrocarbyloxysilane.

[0099] <7> The cured product according to <5> or <6> described above, wherein the di-functional hydrocarbyloxysilane comprises 80 mol% or more of dimethoxydimethylsilane with respect to the total mol% of the di-functional hydrocarbyloxysilane.

[0100] <8> The cured product according to any one of <5> to <7> described above, wherein a pencil hardness of the cured product is HB or more.

[0101] <9> The cured product according to any one of <5> to <8> described above, wherein a Vickers hardness of the cured product is 1 HV or more.

[0102] <10> The cured product according to any one of <5> to <9> described above, wherein an ultraviolet absorption end wavelength of the cured product is 250 nm or less.

[0103] <11> The cured product according to any one of <5> to <10> described above, wherein a thickness of the cured product is 4.8 mm or more.

[0104] <12> The cured product according to any one of <5> to <11> above, wherein the cured product is used for an electrical / electronic component use.

[0105] <13> A method for producing a polysilsesquioxane-based liquid precursor, wherein, without using an organic solvent, in an aqueous solution, in the presence of an acid catalyst, a trivalent hydrocarbyloxysilane and a bivalent hydrocarbyloxysilane are allowed to mature while undergoing a hydrolysis reaction and a polycondensation reaction.

[0106] <14> The method for producing a polysilsesquioxane-based liquid precursor according to <13> above, wherein the trivalent hydrocarbyloxysilane is used in an amount of 0.5 moles to 0.99 moles per 1 mole of the total hydrocarbyloxysilane.

[0107] <15> The method for producing a polysilsesquioxane-based liquid precursor according to <13> or <14> above, wherein the acid catalyst is used in an amount of more than 0 moles and less than or equal to 0.01 moles per 1 mole of the total hydrocarbyloxysilane.

[0108] <16> The method for producing a polysilsesquioxane-based liquid precursor according to any one of <13> to <15> above, wherein water is used in an amount of 1.5 moles to 50 moles per 1 mole of the total hydrocarbyloxysilane.

[0109] <17> The method for producing a polysilsesquioxane-based liquid precursor according to any one of <13> to <16> above, wherein the trivalent hydrocarbyloxysilane contains 80% by mole or more of methyltrimethoxysilane, relative to the total % by mole of the trivalent hydrocarbyloxysilane.

[0110] <18> The method for producing a polysilsesquioxane-based liquid precursor according to any one of <13> to <17> above, wherein the bivalent hydrocarbyloxysilane contains 80% by mole or more of dimethoxydimethylsilane, relative to the total % by mole of the bivalent hydrocarbyloxysilane.

[0111] <19> The method for producing a polysilsesquioxane-based liquid precursor according to any one of <13> to <18> above, wherein the method includes a step of removing alcohol generated in the hydrolysis reaction.

[0112] <20> A method for producing a cured product, wherein a polysilsesquioxane-based liquid precursor obtained by the method for producing a polysilsesquioxane-based liquid precursor according to any one of <13> to <19> above is heated to cure it.

[0113] Example

[0114] The present application is described in detail below by way of examples, but the present application is not limited to these examples. Examples 1 to 27, Example 32, Examples 36 to 39 are examples, and Examples 28 to 31, Example 33 to 35, Example 40 are comparative examples.

[0115] (Test Example 1)

[0116] (Example 1)

[0117] Methyltrimethoxysilane as a trifunctional hydrocarbon oxy silane and dimethoxydimethylsilane as a difunctional hydrocarbon oxy silane were mixed in a ratio of methyltrimethoxysilane: dimethoxydimethylsilane = 0.5:0.5 so that the total of the molar ratio was 1, and the total was 100 millimoles.

[0118] To this, dilute hydrochloric acid containing 0.2 millimoles of hydrogen chloride (HCl / silicon ratio = 0.002) and 250 millimoles of water (water / silicon ratio = 2.5) was added, and stirring was performed at 20°C for 3 hours in a closed container. Then, it was allowed to stand at 80°C for 24 hours to allow it to mature, and hydrolysis and polycondensation were performed.

[0119] After maturation, the container was opened and the upper layer solution after liquid-liquid phase separation was removed by using a Pasteur pipette.

[0120] The lower layer solution was vacuum dried at 60°C for 24 hours, and a colorless transparent liquid precursor was obtained.

[0121] (Examples 2 to 10)

[0122] The same operations as in Example 1 were performed except that the amounts of methyltrimethoxysilane, dimethoxydimethylsilane, and water were changed as shown in Table 1, and a colorless transparent liquid precursor was obtained.

[0123] <Viscosity Measurement>

[0124] The viscosity of the liquid precursor was measured at 30°C and 40°C using an EMS viscometer ("EMS-1000S" manufactured by Kyoto Electronic Industrial Co., Ltd.).

[0125] The results are shown in Table 1.

[0126] <Determination of Molar Mass>

[0127] The mass average molar mass (weight average molecular weight) Mm and the number average molar mass (number average molecular weight) Mn of the liquid precursor were determined by gel permeation chromatography.

[0128] "RID-10A" manufactured by Shimadzu Corporation was used as a detector, "Shodex KF-804L" manufactured by Showa Denko K.K. was used as a column, tetrahydrofuran was used as a solvent, and the measurement was performed under conditions of a flow rate of 1.0 ml / min and a sample amount of 20 μl, and the mass average molar mass and the number average molar mass were calculated based on a standard curve obtained using polystyrene having a known molar mass as a standard substance.

[0129] The results are shown in Table 1.

[0130] <NMR Measurement>

[0131] The liquid precursor was measured using "JMN-ECS300" manufactured by JEOL Ltd. and using CDCl3as a solvent. 1 H and 29 Si NMR spectra. 1 H nuclei were measured at 300 MHz, 29 Si nuclei were measured at 59.6 MHz.

[0132] The respective existence ratios (f 29 Si NMR spectra were used to determine the respective existence ratios (f T1 , f T2 , f T3 , f D1 , f D2 ) of the T type and the D type, and the average number of bridging oxygen was calculated based on the following equation (2). <m> 。

[0133] <m>= (f T1 × n T1 ) + (f T2 × n T2 ) + (f T3 × n T3 ) + (f D1 × n D1 ) + (f D2 × n D2 ) ……(2)

[0134] In formula (2), f T1 is the existence ratio of T 1 type structural units having 1 bridging oxygen among the structural units derived from the tri-functional hydrocarbyloxysilane, n T1 represents 1, which is the number of bridging oxygen of the T 1 type structural units, f T2 is the existence ratio of T 2 type structural units having 2 bridging oxygens among the structural units derived from the tri-functional hydrocarbyloxysilane, n T2 represents 2, which is the number of bridging oxygen of the T 2 type structural units, f T3 is the existence ratio of T 3 type structural units having 3 bridging oxygens among the structural units derived from the tri-functional hydrocarbyloxysilane, n T3 represents 3, which is the number of bridging oxygen of the T 3 type structural units, f D1 is the existence ratio of D 1 type structural units having 1 bridging oxygen among the structural units derived from the di-functional hydrocarbyloxysilane, n D1 represents 1, which is the number of bridging oxygen of the D 1 type structural units, f D2 is the existence ratio of D 2 type structural units having 2 bridging oxygens among the structural units derived from the di-functional hydrocarbyloxysilane, n D2 represents 2, which is the number of bridging oxygen of the D 2 type structural units, f T1 + f T2 + f T3 + f D1 + f D2 = 1.

[0135] Then, the ratio of bridging oxygen is calculated by the following formula (1).

[0136] Ratio of bridging oxygen = 100 x (number of bridging oxygen) / (number of terminal oxygen + number of bridging oxygen) <m> / <m> max ……(1)

[0137] In formula (1), <m> max for all structural units derived from tri-functional hydrocarbyloxysilanes are T 3 for all structural units derived from di-functional hydrocarbyloxysilanes are D 2 for all structural units derived from tri-functional hydrocarbyloxysilanes are T

[0138] Next, the residual methoxy fraction f 1 The residual silanol fraction f SiOMe is determined by the following equation (3) SiOH .

[0139] The residual silanol fraction f SiOH =1- <m> / <m> max +f SiOMe ) ……(3)

[0140] The results are shown in Table 1.

[0141] It is noted that for Examples 2, 4, 8-10, only the maximum average number of bridging oxygen in the total copolymer is reported for the structure of the liquid precursor <m> max In Example 4, only the mass average molar mass Mmand the number average molar mass Mnwere determined, and for Example 2, no physical property determination was performed.

[0142] In Table 1, the presence ratio (f T1 , f T2 , f T3 , f D1 and f D2 ) of the structural units of Example 6, and the sum of the presence ratios (f <m> / <m> max , f SiOMe and f SiOH The sum not being 1 is due to rounding errors of numerical values.

[0143] [Table 1]

[0144] The appearance of the liquid precursors of Examples 1 to 10 is shown in Figure 1 In Figure 1 , (a) is the liquid precursor of Example 1, (b) is the liquid precursor of Example 2, (c) is the liquid precursor of Example 3, (d) is the liquid precursor of Example 4, (e) is the liquid precursor of Example 5, (f) is the liquid precursor of Example 6, (g) is the liquid precursor of Example 7, (h) is the liquid precursor of Example 8, (i) is the liquid precursor of Example 9, and (j) is the liquid precursor of Example 10.

[0145] As shown in Figure 1 (a) to (j), the liquid precursors of Examples 1 to 10 were all obtained in the form of a liquid.

[0146] (Test Example 2)

[0147] (Example 11)

[0148] Methyltrimethoxysilane as a tri-functional hydrocarbonoxy silane and dimethoxydimethylsilane as a di-functional hydrocarbonoxy silane were mixed in a ratio of methyltrimethoxysilane:dimethoxydimethylsilane = 0.8:0.2 so that the total of the molar ratio was 1.

[0149] To this, dilute hydrochloric acid containing 0.02 mmol of hydrogen chloride (HCl / silicon ratio = 0.0002) and 500 mmol of water (water / silicon ratio = 5) was added, and stirring was performed at 20°C for 3 hours in a closed container. Then, it was allowed to stand at 80°C for 24 hours to allow for aging, hydrolysis and polycondensation.

[0150] After aging, the container was opened and the upper layer solution after liquid-liquid phase separation was removed by pipetting with a Pasteur pipette.

[0151] The lower layer solution was vacuum-dried at 60°C for 24 hours, thereby obtaining a colorless transparent liquid precursor.

[0152] (Examples 12 to 19)

[0153] The same operations as in Example 11 were performed except that the amounts of methyltrimethoxysilane, dimethoxydimethylsilane, water and hydrogen chloride were changed as shown in Table 2, thereby obtaining a colorless transparent liquid precursor.

[0154] <Viscosity Measurement>

[0155] The viscosity of the liquid precursor at 40°C was measured in the same manner as in Test Example 1. The results are shown in Table 2.

[0156] <Measurement of molar mass>

[0157] The mass average molar mass and the number average molar mass of the liquid precursor were calculated in the same manner as in Test Example 1. The results are shown in Table 2.

[0158] <NMR measurement>

[0159] The respective existence ratios (f T1 , f T2 , f T3 , f D1 , f D2 ) of the T type and the D type of the liquid precursor were found in the same manner as in Test Example 1. The average bridge oxygen number <m>• the maximum average number of bridging oxygen in the total copolymer <m> max , the ratio of bridging oxygen <m> / <m> max , residual methoxy group fraction f SiOMe , residual silanol group fraction f SiOH These results are shown in Table 2.

[0160] Note that in Table 2, the existence ratio (f T1 , f T2 , f T3 , f D1 and f D2 ) of the structural units of Example 12, and the existence ratio (f <m> / <m> max , f SiOMe and f SiOH The sum not being 1 is due to rounding errors of numerical values.

[0161] [Table 2]

[0162] The appearance of the liquid precursors of Examples 11 to 19 is shown in Figure 2 In Figure 2 , (a) is the liquid precursor of Example 11, (b) is the liquid precursor of Example 12, (c) is the liquid precursor of Example 13, (d) is the liquid precursor of Example 14, (e) is the liquid precursor of Example 15, (f) is the liquid precursor of Example 16, (g) is the liquid precursor of Example 17, (h) is the liquid precursor of Example 18, and (i) is the liquid precursor of Example 19.

[0163] As shown in Figure 2 (a) to (i), the liquid precursors of Examples 11 to 19 were obtained in the form of a liquid.

[0164] (Test Example 3)

[0165] The viscosity change over time was confirmed for the liquid precursors of Examples 12 to 14 and 16 to 19 produced in Test Example 2. Regarding the viscosity, the viscosity at 40°C of the liquid precursors immediately after production and the liquid precursors after being kept in a closed container at room temperature (about 20°C to about 30°C) for the longest period of 60 days was measured using an EMS viscometer "EMS-1000S" manufactured by Kyoto Electronic Industrial Co., Ltd., and the viscosity increase rate (%) was calculated from the following formula.

[0166] Viscosity increase rate (%) = (viscosity after kept at room temperature for 60 days / viscosity immediately after production - 1) x 100

[0167] The results of the viscosity increase rate are shown in Table 3.

[0168] Note that the liquid precursors of Example 12, Example 14, and Example 16 had a viscosity of more than 1 x 10 6 mPa-s before 60 days had passed, and thus the viscosity increase rate could not be measured.

[0169] In addition, regarding Examples 12 to 14 and 17 to 19, the progress of the viscosity of the liquid precursors is shown in Figure 3 In Figure 3 , (a) indicates the results of Examples 12 to 14, and (b) indicates the results of Examples 17 to 19.

[0170] [Table 3]

[0171] According to Table 3 and Figure 3 The liquid precursors of Examples 12 to 14 and Examples 16 to 19 had a slow increase in viscosity and excellent stability over time. In particular, it was found that the liquid precursors of Example 13, Examples 17 to 19 had a small increase in viscosity even after 60 days, and had long-term stability of viscosity.

[0172] (Test Example 4)

[0173] (Example 20)

[0174] Methyltrimethoxysilane as a trifunctional hydrocarbyloxysilane and dimethoxydimethylsilane as a difunctional hydrocarbyloxysilane were mixed at a ratio of methyltrimethoxysilane:dimethoxydimethylsilane = 0.8:0.2 so that the total of the molar ratio was 1.

[0175] To this, dilute hydrochloric acid containing 0.2 mmol of hydrogen chloride (HCl / silicon ratio = 0.002) and 2000 mmol of water (water / silicon ratio = 20) was added, and stirring was performed at 20°C for 3 hours in a closed container. Then, it was allowed to stand at 80°C for 24 hours to allow hydrolysis and polycondensation to proceed.

[0176] After maturation, the container was opened and the upper layer solution after liquid-liquid phase separation was removed by using a Pasteur pipette.

[0177] The lower layer solution was vacuum-dried at 60°C for 24 hours, thereby obtaining a colorless transparent liquid precursor.

[0178] (Examples 21 to 24)

[0179] The same operations as in Example 20 were performed except that the amounts of methyltrimethoxysilane, dimethoxydimethylsilane, water, and hydrogen chloride were changed as shown in Table 4, thereby obtaining a colorless transparent liquid precursor.

[0180] Note that the liquid precursor of Example 22 was the same as that of Example 13.

[0181] <Viscosity Measurement>

[0182] The same operations as in Test Example 1 were performed, and the viscosity of the liquid precursor at 40°C was measured. The results are shown in Table 4.

[0183] <Determination of Molar Mass>

[0184] The same operations as in Test Example 1 were performed, and the mass average molar mass and the number average molar mass of the liquid precursor were calculated. The results are shown in Table 4.

[0185] [Table 4]

[0186] The appearance of the liquid precursors of Examples 20 to 24 is shown in Figure 4 In the table, (a) is the liquid precursor of Example 20, (b) is the liquid precursor of Example 21, (c) is the liquid precursor of Example 22, (d) is the liquid precursor of Example 23, and (e) is the liquid precursor of Example 24. Figure 4 In the table, (a) is the liquid precursor of Example 20, (b) is the liquid precursor of Example 21, (c) is the liquid precursor of Example 22, (d) is the liquid precursor of Example 23, and (e) is the liquid precursor of Example 24.

[0187] As shown in (a) to (e) of the table, the liquid precursors of Examples 20 to 24 were all obtained in the form of a liquid. Figure 4 As shown in (a) to (e) of the table, the liquid precursors of Examples 20 to 24 were all obtained in the form of a liquid.

[0188] (Test Example 5)

[0189] (Example 25)

[0190] The liquid precursor of Example 13 was heated at 200°C for 24 hours under a nitrogen atmosphere, thereby obtaining a cured product having a thickness of 4.9 mm. The appearance of the obtained cured product (a photograph viewed from above) is shown in (a) of the figure. Figure 5

[0191] (Example 26)

[0192] The liquid precursor of Example 13 was heated at 200°C for 12 hours and then at 250°C for 24 hours under a nitrogen atmosphere, thereby obtaining a cured product having a thickness of 5.4 mm. The appearance of the obtained cured product (a photograph viewed from above) is shown in (b) of the figure. Figure 5

[0193] (Example 27)

[0194] The total amount of methyltrimethoxysilane as a tri-functional hydrocarbyloxysilane and dimethoxydimethylsilane as a di-functional hydrocarbyloxysilane was adjusted to 300 millimoles, and otherwise, the same as Example 13 was made, thereby obtaining a colorless transparent liquid precursor. The flowability of the liquid precursor was equivalent to that of Example 13 by visual observation, and thus the 40°C viscosity was judged to be equivalent to that of Example 13.

[0195] The obtained liquid precursor was put into a mold having a diameter of 30 mm and a depth of 20 mm, and heated at 120°C for 6 hours, at 180°C for 6 hours, and then at 250°C for 24 hours under a nitrogen atmosphere, thereby obtaining a cured product having a thickness of 15.6 mm. The plan view of the obtained cured product is shown in (a) of the figure, and the side view of the obtained cured product is shown in (b) of the figure. Figure 6 Figure 6

[0196] (Example 28)

[0197] ​​​​To 100 mmol of ethyltrimethoxysilane as a tri-functional hydrocarbonoxy silane, dilute hydrochloric acid containing 0.02 mmol of hydrogen chloride (HCl / silicon ratio = 0.0002) and 2000 mmol of water (water / silicon ratio = 20) was added, and stirred at 20°C for 3 hours in a closed container. Then, it was allowed to stand at 80°C for 24 hours to effect hydrolysis and polycondensation.

[0198] After maturation, the container was opened after cooling to room temperature, and the upper layer solution after liquid-liquid phase separation was removed by pipetting with a Pasteur pipette.

[0199] The lower layer solution was vacuum-dried at 60°C for 24 hours to obtain a colorless transparent liquid precursor. The 40°C viscosity of the liquid precursor was 27300 mPa-s.

[0200] The obtained liquid precursor was heated at 200°C for 24 hours under a nitrogen atmosphere to obtain a cured product having a thickness of 4.8 mm. The appearance of the obtained cured product (photograph viewed from above) is shown in Figure 7 (a) of the figure.

[0201] (Examples 29 to 31)

[0202] The operation was carried out in the same manner as in Example 28 except that the heating conditions of the liquid precursor were changed as described in Table 5 to obtain a cured product. The appearance of the obtained cured product (photograph viewed from above) is shown in Figure 7 (b) to (d) of the figure. In Figure 7 , (b) is the cured product of Example 29, (c) is the cured product of Example 30, and (d) is the cured product of Example 31.

[0203] <Measurement of hardness>

[0204] The measurement of the pencil hardness of the cured product was carried out by hand drawing method according to the pencil scratch test prescribed in the old JIS K 5400.

[0205] First, the lead tip of the pencil used for the test was brought into vertical contact with the 400# abrasive paper placed on a hard and flat surface, and was ground to make the lead tip flat and the corners sharp. The ground lead tip was brought into contact with the surface of the cured product at 45°, and was drawn over the coating surface at a uniform speed to about 1 cm in front of the tester while pressing the lead tip on the coating surface as much as possible without breaking. The drawing speed was about 1 cm / sec.

[0206] The lead tip of the ground pencil was ground every 1 draw, and the test was repeated 5 times using the same concentration of pencil. The hardness of the pencil was recorded as the next lower concentration mark when the damage or scratch of the coating film reached 2 times or more in 5 tests.

[0207] As an evaluation standard, from the hard side, the evaluation was 9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, 4B, 5B, 6B. The results are shown in Table 5.

[0208] [Table 5]

[0209] According to the results of Table 5 and Figures 5 to 7 In Examples 25 to 27, a transparent cured product having a high hardness and a sufficient thickness was obtained. In particular, in Example 27, a cured product having a thickness of 15.6 mm was able to be formed. On the other hand, in Example 28 and Example 29, a bubble was generated, the appearance was poor, and the pencil hardness was also low. In Example 30, a large number of cracks were generated on the surface by heat treatment, and in Example 31, compared to Example 28 and Example 29, the generation of a bubble was suppressed, but a partial appearance defect was generated, and the pencil hardness was also low. From these results, it was known that by using a trifunctional hydrocarbyloxysilane having an organic functional group of a methyl group and a difunctional hydrocarbyloxysilane, a cured product having a high hardness and an improved appearance could be obtained.

[0210] (Test Example 6)

[0211] (Example 32)

[0212] The cured product of Example 26 produced in Test Example 5 was cut into a size of 5 mm in the longitudinal direction x 5 mm in the lateral direction x 4 mm in height, and used as a test piece of Example 32.

[0213] (Example 33)

[0214] The cured product of Example 29 produced in Test Example 5 was cut into a size of 5 mm in the longitudinal direction x 5 mm in the lateral direction x 4 mm in height, and used as a test piece of Example 33.

[0215] (Example 34)

[0216] A commercially available polymethyl methacrylate (PMMA) resin ("ACRYLITE (registered trademark) L001" manufactured by Mitsubishi Chemical Corporation) was prepared.

[0217] The PMMA resin was cut into a size of 5 mm in the longitudinal direction x 5 mm in the lateral direction x 4 mm in height, and used as a test piece of Example 34.

[0218] (Example 35)

[0219] A commercially available polyethylene terephthalate (PET) resin ("Sanloid Pet Ace EPG100" manufactured by Sumitomo Bakelite Co., Ltd.) was prepared.

[0220] The PET resin was cut into a size of 5 mm in the longitudinal direction x 5 mm in the lateral direction x 4 mm in height, and used as a test piece of Example 35.

[0221] <Uniaxial loading and unloading test>

[0222] The stress-strain curve at this time was measured by applying compression at a rate of 0.5 mm / min in displacement control to each sample. Next, the stress-strain curve at the time of unloading at a rate of 0.5 mm / min was measured.

[0223] The results are shown in Figure 8 .

[0224] From the results according to Figure 8 , in Example 32, compared with Examples 34 and 35, when unloading, the strain returned to a stage close to the initial state, showing a strong elastic behavior. In addition, in Example 33, yielding at a high stress, and not returning to the initial state after unloading.

[0225] (Test Example 7)

[0226] Using the cured product of Example 26 produced in Test Example 5, the ultraviolet absorption edge wavelength was found.

[0227] <Measurement of ultraviolet-visible light absorption spectrum>

[0228] The ultraviolet-visible light absorption spectrum was measured using a spectrophotometer ("U-4100" manufactured by Hitachi High-Technologies Corporation), and the spectrum of the light absorption coefficient was obtained by normalizing the sample thickness.

[0229] The ultraviolet absorption edge wavelength was found as the intersection point of the approximate straight line of the spectrum of the ultraviolet absorption edge region of the obtained absorption spectrum and the approximate straight line of the baseline spectrum of the transparent region on the long wavelength side.

[0230] The ultraviolet absorption edge was observed around 195 nm, and thus it was known that there was high transparency in the ultraviolet region.

[0231] (Test Example 8)

[0232] (Example 36)

[0233] The liquid precursor of Example 9 produced in Test Example 1 (viscosity at 40°C: 23300 mPa-s) was heated at 200°C for 12 hours and then at 250°C for 24 hours in a nitrogen atmosphere, and thus a cured product was obtained.

[0234] (Example 37)

[0235] Methyltrimethoxysilane as a trifunctional hydrocarbyloxysilane and dimethoxydimethylsilane as a difunctional hydrocarbyloxysilane were mixed in a ratio of methyltrimethoxysilane:dimethoxydimethylsilane = 0.75:0.25 so that the total of the molar ratio was 1, and the total was 100 millimoles.

[0236] To this was added dilute hydrochloric acid containing 0.2 millimoles of hydrogen chloride (HCl / silica ratio = 0.002) and 3000 millimoles of water (water / silica ratio = 30), and stirring was performed at 20°C for 3 hours in a closed container. Then, aging was performed by standing at 80°C for 24 hours to perform hydrolysis and polycondensation.

[0237] After aging, the container was opened after cooling to room temperature, and the upper layer solution after liquid-liquid phase separation was removed by pipetting with a Pasteur pipette.

[0238] The lower layer solution was vacuum-dried at 60°C for 24 hours, and a colorless transparent liquid precursor was obtained. The 40°C viscosity of the liquid precursor was 50400 mPa s.

[0239] The obtained liquid precursor was heated at 200°C for 12 hours and then at 250°C for 24 hours under a nitrogen atmosphere, and a cured product was obtained.

[0240] (Example 38)

[0241] The cured product of Example 26 produced in Test Example 5 was used.

[0242] (Example 39)

[0243] The same operation as in Example 37 was performed except that the amounts of methyltrimethoxysilane, dimethoxydimethylsilane, hydrogen chloride and water were changed as shown in Table 6, and a colorless transparent liquid precursor was obtained. The 40°C viscosity of the liquid precursor was 1 x 10 6 mPa s or more.

[0244] The obtained liquid precursor was heated at 150°C for 12 hours and then at 250°C for 24 hours under a nitrogen atmosphere, and a cured product was obtained.

[0245] (Example 40)

[0246] The cured product of Example 29 produced in Test Example 5 was used.

[0247] <Measurement of Hardness>

[0248] The Vickers hardness of the cured product was measured in accordance with JIS R 1610-2003. The results are shown in Table 6.

[0249] [Table 6]

[0250] From the results of Table 6, in Examples 36 to 39, the Vickers hardness was all 4 or more, and in Examples 38 and 39 in which the proportion of methyltrimethoxysilane in all hydrocarbyloxysilanes was 0.8 or more, elastic recovery occurred and indentation observation could not be performed. In contrast, in Example 40, the Vickers hardness was as low as 2.8, and the hardness could not be maintained.

[0251] The present application has been described in detail based on specific embodiments, but various modifications or corrections can be made without departing from the spirit and scope of the present application, which will be apparent to those skilled in the art. This application is based on Japanese Patent Application (Japanese Patent Application No. 2023-138037) filed on August 28, 2023, the contents of which are incorporated herein by reference.< / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> < / m> ​

Claims

1. A polysilsesquioxane liquid precursor comprising a copolymer of trifunctional hydroxyl-containing silicon and difunctional hydroxyl-containing silicon, wherein, The residual silanol group fraction f in the copolymer SiOH It ranges from 0.02 to 0.

3.

2. The polysilsesquioxane liquid precursor according to claim 1, wherein, The viscosity of the polysilsesquioxane-based liquid precursor at 40°C is 1×10⁻⁶. 6 Below mPa·s.

3. The polysilsesquioxane liquid precursor according to claim 1, wherein, The trifunctional hydroxyl group comprises more than 80 mol% methyltrimethoxysilane relative to the total mole percentage of the trifunctional hydroxyl group silicon.

4. The polysilsesquioxane liquid precursor according to claim 1, wherein, The difunctional hydroxyl group comprises more than 80 mol% of dimethoxydimethylsilane relative to the total mole percentage of the difunctional hydroxyl group silicon.

5. A cured product, which is a cured product of a copolymer of trifunctional hydroxyl silicon and difunctional hydroxyl silicon, wherein, The residual silanol group fraction f in the copolymer SiOH It ranges from 0.02 to 0.

3.

6. The cured product according to claim 5, wherein, The trifunctional hydroxyl group comprises more than 80 mol% methyltrimethoxysilane relative to the total mole percentage of the trifunctional hydroxyl group silicon.

7. The cured product according to claim 5, wherein, The difunctional hydroxyl group comprises more than 80 mol% of dimethoxydimethylsilane relative to the total mole percentage of the difunctional hydroxyl group silicon.

8. The cured product according to claim 5, wherein, The pencil hardness of the cured material is HB or higher.

9. The cured product according to claim 5, wherein, The Vickers hardness of the cured material is above 1HV.

10. The cured product according to claim 5, wherein, The wavelength of the ultraviolet absorption end of the cured material is below 250nm.

11. The cured product according to claim 5, wherein, The thickness of the cured material is 4.8 mm or more.

12. The cured product according to claim 5, wherein, The cured material is used for electrical / electronic components.

13. A method for manufacturing a polysilsesquioxane-based liquid precursor, wherein, Instead of using organic solvents, the trifunctional and difunctional hydroxyl groups are matured in aqueous solution in the presence of an acid catalyst during hydrolysis and polycondensation reactions.

14. The method for manufacturing the polysilsesquioxane liquid precursor according to claim 13, wherein, The trifunctional hydroxyl-oxysilane is used in amounts of 0.5 to 0.99 moles relative to 1 mole of total hydroxyl-oxysilane.

15. The method for manufacturing the polysilsesquioxane liquid precursor according to claim 13, wherein, The acid catalyst is used in an amount greater than 0 moles and less than or equal to 0.01 moles relative to 1 mole of all hydroxyl-containing silicon.

16. The method for manufacturing the polysilsesquioxane liquid precursor according to claim 13, wherein, Use water in amounts of 1.5 to 50 moles relative to 1 mole of total hydroxyl silicon.

17. The method for manufacturing the polysilsesquioxane liquid precursor according to claim 13, wherein, The trifunctional hydroxyl group comprises more than 80 mol% methyltrimethoxysilane relative to the total mole percentage of the trifunctional hydroxyl group silicon.

18. The method for manufacturing the polysilsesquioxane liquid precursor according to claim 13, wherein, The difunctional hydroxyl group comprises more than 80 mol% of dimethoxydimethylsilane relative to the total mole percentage of the difunctional hydroxyl group silicon.

19. The method for manufacturing the polysilsesquioxane liquid precursor according to claim 13, wherein, The manufacturing method includes the step of removing the alcohol generated in the hydrolysis reaction.

20. A method for manufacturing a solidified material, wherein, The polysilsesquioxane liquid precursor obtained by the manufacturing method of any one of claims 13 to 19 is heated to solidify it.

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