JP7144331B2 - Silanol composition, cured product, adhesive, composite film, and curing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to silanol compositions, cured products, adhesives, composite films, and curing methods.

Low Earth orbit (LEO) is an orbit widely used for earth observation satellites, space shuttles, spacecraft such as the International Space Station, and the like. With the advent of the space shuttle, it has become clear that the material exposed to this orbital environment will undergo significant erosion when it becomes possible to travel back and forth. The main component of the atmosphere in low earth orbit is atomic oxygen. When a spacecraft flies in low earth orbit, the surface of the spacecraft exposed to the atmosphere becomes highly reactive with atomic oxygen. It is said that it is significantly degraded by collision. In addition to atomic oxygen, there are reports that active gas species such as oxygen ions and atomic nitrogen also exist in the atmosphere and affect the deterioration of spacecraft.

To address this problem, for example, Patent Document 1 discloses a method of improving the resistance to atomic oxygen by applying an insulating film made of a silicone-based resin film to the surface of a structural material for space use.

Spacecraft are subjected to severe temperature cycles from low temperature (radiation into outer space) to high temperature (incidence of strong sunlight). there is Organic materials such as polyimide are widely used as heat-resistant films for these thermal control materials. However, organic materials have the problem of being colored by ultraviolet light. Colored films have a higher sunlight absorption rate, so they become hotter when exposed to sunlight, and furthermore, heat deterioration and ultraviolet deterioration accelerated by high temperatures occur. It tends to get easier. Here, the solar absorptivity is an index of the easiness of receiving heat input from sunlight, and represents the easiness of absorbing solar energy.

Patent Literature 2 discloses a method of improving resistance to atomic oxygen by applying an insulating film made of a silicone-based resin film on a polyimide film. Further, Patent Document 2 discloses that conventional silicone-based resins have a problem of outgassing, and it is preferable to use a thermosetting resin or an inorganic filler in combination as a countermeasure.

Outgassing is broadly defined as low molecular weight components released from a material. When the silicone-based resin film is exposed to atomic oxygen, the volatilized components redeposit on the surroundings. Volatile components that have reattached to the surroundings, for example, adsorb to the surface of the solar cell panel and reduce the output of the solar cell, or reduce the characteristics of optical equipment such as sensors and cameras. cause a problem called In addition, it is conceivable that deposits due to outgassing are colored by ultraviolet rays, which lowers the light transmittance, thereby further advancing the functional deterioration of the above equipment. As described above, the combined use of thermosetting resins and inorganic fillers is preferable in order to prevent the generation of outgassing, but the combined use may impair the transparency of the cured product. Therefore, combined use of a thermosetting resin and an inorganic filler results in a decrease in light transmittance, which is not sufficient as a measure for preventing functional deterioration of functional devices.

Patent Document 3 also discloses an inorganic film containing aluminum as an essential component instead of a silicone resin as a method for improving the atomic oxygen resistance of a polyimide film. Such an inorganic film has the characteristic of being resistant to deterioration by ultraviolet rays. It shows that the mass change rate was -3.6%. Thus, the resistance to atomic oxygen is not sufficient. In addition, since the formation of the inorganic film requires a very high temperature of 480° C., there is a problem that the application of the inorganic film is limited to substrates that can withstand high temperature treatment.

In addition, in Patent Document 4, in order to improve the insufficient performance of the protective materials described in Patent Documents 1 to 3, a polysiloxane containing a silsesquioxane structural unit, that is, the formula A curable composition for outer space is proposed, which is characterized by containing the polysiloxane represented by (1).

In formula (1), R ¹ , R ² and R ³ are each independently an alkyl group having 1 to 6 carbon atoms, an aralkyl group having 7 to 10 carbon atoms, an aryl group having 6 to 10 carbon atoms, or (meth)acryloyl. represents a monovalent organic group having a group, an epoxy group or an oxetanyl group, and the alkyl group, aralkyl group, aryl group, (meth)acryloyl group, epoxy group and oxetanyl group are halogen atoms, hydroxy groups, alkoxy groups and aryloxy groups. group, aralkyloxy group and/or oxy group, and at least one of R ¹ , R ² and R ³ in the polysiloxane represented by formula (1) is (meth) a monovalent organic group having an acryloyl group, an epoxy group or an oxetanyl group, w represents a positive number, v, x and y each independently represents 0 or a positive number, R ¹ , R ² and Each R ³ may be the same or different.

JP-A-5-270500 JP 2003-113264 A Japanese Patent Application Laid-Open No. 2004-225006 JP 2011-42755 A

The curable composition for outer space disclosed in Patent Document 4 has (A) durability against atomic oxygen, (B) suppression of increase in solar absorptivity due to ultraviolet rays, (C) suppression of outgassing, and (D) surface It is said to be a curable composition for outer space that is excellent in three or more performances (characteristics) including (A) and (C) among non-adhesiveness and (E) cured film followability.

However, as a space material such as a protective material, it is required to have even better performance. When used in materials for outer space (for example, protective materials), it is particularly required to be excellent in suppressing an increase in solar absorptivity and vertical infrared emissivity due to electron beams, and in heat yellowing properties. ing. However, these characteristics are not examined for the protective material described in Patent Document 4. In addition, not only space materials but also radiation-resistant materials are required to have excellent properties.

The objects of the present invention are (A) durability against atomic oxygen, (B) suppression of increase in solar absorption rate due to atomic oxygen, ultraviolet rays, and electron beams, and (C) vertical absorption by atomic oxygen, ultraviolet rays, and electron beams. Obtaining a cured product with an excellent balance of infrared emissivity increase suppression, (D) outgas suppression, (E) surface non-stickiness, (F) heat yellowing, (G) adhesion, and (H) transparency. It is an object of the present invention to provide a curable composition which can be used for radiation resistance or outer space.

As a result of intensive research to solve the above problems, the present inventors found that from a specific silanol composition, (A) durability against atomic oxygen, (B) atomic oxygen, ultraviolet rays, and solar radiation caused by electron beams. (C) Inhibition of increase in vertical infrared emissivity due to atomic oxygen, ultraviolet rays, and electron beams, (D) Outgassing inhibition, (E) Surface non-adhesiveness, (F) Heat yellowing , (G) Adhesive strength, and (H) A cured product excellent in transparency can be obtained, thereby completing the present invention.

（式（Ｉ）中、Ｒは、各々独立して、フッ素原子、アリール基、ビニル基、アリル基、フッ素で置換された直鎖状若しくは分岐状の炭素数１～４のアルキル基、又は非置換の直鎖状若しくは分岐状の炭素数１～４のアルキル基であり、ｎは、２～１０の整数である。）
［２］
前記環状シラノール（Ａ１）が、下記式（１）で表される、［１］に記載のシラノール組成物。

（式（１）中、Ｒ¹～Ｒ⁴は、各々独立して、フッ素原子、アリール基、ビニル基、アリル基、フッ素で置換された直鎖状若しくは分岐状の炭素数１～４のアルキル基、又は、非置換の直鎖状若しくは分岐状の炭素数１～４のアルキル基である。）
［３］
前記環状シラノール（Ａ１）が、下記式（２）～（５）で表される環状シラノール（Ｂ１）～（Ｂ４）：

（式（２）～（５）中、Ｒ¹～Ｒ⁴は、各々独立して、フッ素原子、アリール基、ビニル基、アリル基、フッ素で置換された直鎖状若しくは分岐状の炭素数１～４のアルキル基、又は、非置換の直鎖状若しくは分岐状の炭素数１～４のアルキル基である。）
を含有し、
前記環状シラノール（Ｂ１）～（Ｂ４）の総量に対する前記環状シラノール（Ｂ２）の割合（モル％）をｂとしたとき、０＜ｂ≦２０を満たす、
［１］又は［２］に記載のシラノール組成物。
［４］
ゲルパーミエーションクロマトグラフィーの測定において、前記脱水縮合物（Ａ２）の面積が、前記環状シラノール（Ａ１）及び前記脱水縮合物（Ａ２）の総面積に対して、０％超過５０％以下である、
［１］～［３］のいずれかに記載のシラノール組成物。
［５］
遷移金属の割合が、１質量ｐｐｍ未満である、
［１］～［４］のいずれかに記載のシラノール組成物。
［６］
溶媒を含む、
［１］～［５］のいずれかに記載のシラノール組成物。
［７］
１ｎｍ以上１００ｎｍ以下の平均粒子径を有するシリカ粒子を含む、
［１］～［６］のいずれかに記載のシラノール組成物。
［８］
下記式（６）で表される両末端シラノール変性シロキサンを含む、
［１］～［７］のいずれかに記載のシラノール組成物。

（式（６）中、Ｒ’は、各々独立して、フッ素原子、アリール基、ビニル基、アリル基、フッ素で置換された直鎖状若しくは分枝状の炭素数１～４のアルキル基、又は、非置換の直鎖状若しくは分岐状の炭素数１～４のアルキル基であり、ｍは０～１０００の整数である。）
［９］
Ｎａ及びＶの合計含有割合が、６０質量ｐｐｍ未満である、
［１］～［８］のいずれかに記載のシラノール組成物。
［１０］
［１］～［９］のいずれかに記載のシラノール組成物の硬化物であって、耐放射線用又は宇宙空間用に用いられる硬化物。
［１１］
［１］～［９］のいずれかに記載のシラノール組成物を含み、耐放射線用又は宇宙空間用に用いられる接着剤。
［１２］
フィルムと、
前記フィルム上に配置された硬化物と、
を含み、耐放射線用又は宇宙空間用に用いられる複合膜であって、
前記硬化物が、［１０］に記載の硬化物である、複合膜。
［１３］
［１］～［９］のいずれかに記載のシラノール組成物を熱硬化させる硬化方法であって、
硬化温度が、６０～２５０℃である、硬化方法。
［１４］
硬化時間が、１０分～７２時間である、［１３］に記載の硬化方法。 That is, the present invention is as follows.
[1]
A silanol composition containing a cyclic silanol (A1) represented by the following formula (1) and a dehydration condensate (A2) thereof, and which is used for radiation resistance or outer space use.

(In formula (I), each R is independently a fluorine atom, an aryl group, a vinyl group, an allyl group, a fluorine-substituted linear or branched alkyl group having 1 to 4 carbon atoms, or a non It is a substituted linear or branched alkyl group having 1 to 4 carbon atoms, and n is an integer of 2 to 10.)
[2]
The silanol composition according to [1], wherein the cyclic silanol (A1) is represented by the following formula (1).

(In formula (1), R ¹ to R ⁴ each independently represent a fluorine atom, an aryl group, a vinyl group, an allyl group, or a fluorine-substituted linear or branched alkyl having 1 to 4 carbon atoms) or an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms.)
[3]
The cyclic silanols (A1) are cyclic silanols (B1) to (B4) represented by the following formulas (2) to (5):

(In formulas (2) to (5), R ¹ to R ⁴ each independently represent a fluorine atom, an aryl group, a vinyl group, an allyl group, or a fluorine-substituted linear or branched chain having 1 carbon atom. to 4 alkyl groups, or unsubstituted linear or branched C 1-4 alkyl groups.)
contains
where b is the ratio (mol%) of the cyclic silanol (B2) to the total amount of the cyclic silanols (B1) to (B4), satisfying 0 < b ≤ 20,
The silanol composition according to [1] or [2].
[4]
In measurement by gel permeation chromatography, the area of the dehydrated condensation product (A2) is more than 0% and 50% or less with respect to the total area of the cyclic silanol (A1) and the dehydrated condensation product (A2).
The silanol composition according to any one of [1] to [3].
[5]
the proportion of transition metals is less than 1 ppm by weight;
The silanol composition according to any one of [1] to [4].
[6]
containing solvents,
[1] The silanol composition according to any one of [5].
[7]
including silica particles having an average particle size of 1 nm or more and 100 nm or less,
The silanol composition according to any one of [1] to [6].
[8]
Including both terminal silanol-modified siloxane represented by the following formula (6),
The silanol composition according to any one of [1] to [7].

(in formula (6), each R' is independently a fluorine atom, an aryl group, a vinyl group, an allyl group, a fluorine-substituted linear or branched alkyl group having 1 to 4 carbon atoms, Alternatively, it is an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms, and m is an integer of 0 to 1000.)
[9]
The total content of Na and V is less than 60 mass ppm,
The silanol composition according to any one of [1] to [8].
[10]
A cured product of the silanol composition according to any one of [1] to [9], which is used for radiation resistance or space use.
[11]
An adhesive that contains the silanol composition according to any one of [1] to [9] and is used for radiation resistance or outer space.
[12]
a film;
A cured product placed on the film;
A composite membrane used for radiation resistance or outer space, comprising
A composite film, wherein the cured product is the cured product according to [10].
[13]
A curing method for thermally curing the silanol composition according to any one of [1] to [9],
A curing method in which the curing temperature is 60 to 250°C.
[14]
The curing method according to [13], wherein the curing time is 10 minutes to 72 hours.

According to the present invention, (A) durability against atomic oxygen, (B) suppression of increase in solar absorption rate due to atomic oxygen, ultraviolet rays, and electron beams, and (C) vertical absorption due to atomic oxygen, ultraviolet rays, and electron beams To obtain a cured product excellent in infrared emissivity increase suppression property, (D) outgas suppression property, (E) surface non-tackiness, (F) heat yellowing, (G) adhesive strength, and (H) transparency. can provide a silanol composition.

FIG. 10 shows the ¹ H-NMR spectrum used for calculating the stereoisomer ratio of the silanol composition obtained in Example 10. FIG. FIG. 10 shows ¹ H-NMR spectra used for calculating the stereoisomer ratio of the silanol composition obtained in Example 16. FIG.

EMBODIMENT OF THE INVENTION Hereinafter, the form (henceforth "this embodiment") for implementing this invention is demonstrated in detail. It should be noted that the present invention is not limited to this embodiment, and various modifications can be made within the scope of the gist of the present invention.

(Silanol composition)
The silanol composition of the present embodiment comprises a cyclic silanol (A1) represented by formula (I) and a dehydration condensate (A2) of the cyclic silanol (A1) represented by formula (I), and is resistant to radiation. or for outer space. In the present specification, the "silanol composition" of this embodiment is also referred to as "curable composition".

In formula (I), each R is independently a fluorine atom, an aryl group, a vinyl group, an allyl group, a fluorine-substituted linear or branched alkyl group having 1 to 4 carbon atoms, or an unsubstituted is a linear or branched alkyl group having 1 to 4 carbon atoms, and n is an integer of 2 to 10.

"Outer space" in this embodiment is a concept that includes all of low earth orbit (altitude of 2000 km or less from the surface of the earth, preferably 100 to 1000 km) and space farther than the low earth orbit. In addition, "outer space" is a concept that includes sanitary space such as the moon and space inside a satellite, as well as space on and inside a planet such as Venus and Mars. Furthermore, "outer space" is a concept that includes the interior of spacecraft (eg, earth observation satellites, space shuttles, international space stations, etc.) that exist in the outer space.

Further, "outer space" in the present embodiment refers to a space in which atomic oxygen exists. Active gases such as oxygen ions and atomic nitrogen may or may not exist in this outer space. The silanol composition of the present embodiment is suitable for use as a material for such spacecraft components exposed to outer space (for example, components of spacecraft). Therefore, the silanol composition of this embodiment can also be called a silanol composition for outer space. However, the silanol composition of the present embodiment is not limited to use only in outer space, and as described later, the silanol composition of the present embodiment is also used for radiation resistance.

The silanol composition of the present embodiment can be used, for example, for components of spacecraft. Silanol compositions are, for example, heat control materials, heat insulating films, sheets, fabrics, paints, solar reflectors, thermally conductive adhesives, thermal fillers, structural panels (e.g., composite materials, etc.), trusses, tethers (e.g., strings, etc.), debris bumpers (e.g., plates or cushioning materials that protect spacecraft from space debris), solar battery paddles (e.g., solar battery cell protective covers, etc.), electric wires, insulating coatings, heaters, antenna constituent materials, It is used for cameras, monitors, lighting and their protective covers (for example, radio wave transparent radomes, etc.), robot arms, and the like.

In addition, the silanol composition of the present embodiment can be used for outer skins of space suits in general, heat-insulating tiles and window materials for spacecraft, lunar and planetary space bases or structures in probes, probes and exploration satellites, large deployment structures, Films, sheets, fabrics, foams and shape memory materials for space inflatable structures or solar sails (e.g. solar sailing ships, large structures using photon pressure propulsion, etc.), space elevator cables and elevator housings, end-of-service space It is used for films, sheets, foam materials, etc. for deorbiting aircraft (for example, deorbit using increased air resistance).

Furthermore, the silanol composition of the present embodiment is used for handling on the earth when used for the above applications, damage during launch or space operation, deterioration (moisture absorption, oxidation, etc.) and material surface protection for preventing contamination. is also used.

In addition, the silanol composition of the present embodiment has excellent resistance to radiation such as electron beams, as described above. Therefore, the silanol composition of the present embodiment can be used for materials resistant to radiation such as electron beams.

The silanol composition of the present embodiment is also used for radiation-resistant materials, that is, radiation-resistant materials, and can be called a radiation-resistant silanol composition. The term “radiation-resistant materials” used herein refers to materials that are required to be resistant to radiation (e.g., alpha rays, beta rays, neutron rays, proton rays, heavy ion rays, meson rays, gamma rays, X-rays, and electron rays). Say.

The radiation-resistant silanol composition of the present embodiment is used in fast breeder reactors, nuclear power plants, radiation irradiation facilities, nuclear fuel disposal work, decommissioning work, uranium enrichment facilities, radioactive waste treatment facilities, spent fuel reprocessing facilities, etc. , is a material used for objects exposed to radiation such as electron beams.

The radiation-resistant silanol composition of this embodiment can be used, for example, in fast breeder reactors, nuclear power plants, radiation irradiation facilities, nuclear fuel disposal work, decommissioning work, uranium enrichment facilities, radioactive waste treatment facilities, spent fuel reprocessing facilities. Films, sheets, textiles, foaming agents and Used for shape memory materials, adhesives, etc.

The silanol composition of the present embodiment can also be called a curable composition. The cured product obtained from the silanol composition has (A) durability against atomic oxygen, (B) resistance to increase in sunlight absorption rate due to atomic oxygen, ultraviolet rays, and electron beams, and (C) atomic oxygen, ultraviolet rays, and It is excellent in suppression of increase in vertical infrared emissivity due to electron beams, (D) suppression of outgassing, (E) surface non-stickiness, (F) heat yellowing, (G) adhesion, and (H) transparency.

The silanol composition of the present embodiment is excellent in heat resistance to yellowing, which is a property not found in conventional curable compositions for outer space. The factors that make the silanol composition of the present embodiment excellent in resistance to heat yellowing are considered as follows, but the factors are not limited thereto. That is, conventional curable compositions for outer space require the addition of components such as cationic polymerization initiators or radical polymerization initiators for curing. In addition, conventional curable compositions for outer space need to contain (introduce) polymerizable groups into polysiloxane contained in the curable composition for curing. Due to these reasons, conventional curable compositions for outer space tend to be inferior in yellowing due to heat. On the other hand, in the silanol composition of the present embodiment, the cyclic silanol contained in the silanol composition has a specific structure, so that a polymerizable group can be introduced, a cationic polymerization initiator or a radical polymerization initiator, etc. It cures well with or without the use of Therefore, the silanol composition of the present embodiment is considered to be excellent in heat resistance to yellowing.

In formula (I), each R independently represents the number of fluorine-substituted linear or branched carbon atoms from the viewpoint of imparting heat-resistant yellowing to the cured product of the silanol composition at higher temperatures. 1 to 4 alkyl groups, or unsubstituted linear or branched C 1 to 4 alkyl groups, preferably unsubstituted linear or branched C 1 to 4 alkyl groups is more preferred, and a methyl group is even more preferred. Specific examples of the fluorine-substituted linear or branched alkyl group having 1 to 4 carbon atoms and the unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms will be described later.

In formula (I), n is preferably 2 to 5, more preferably 2 to 4, and even more preferably 3. When n is 2 to 5, the balance between flexibility and rigidity of the main chain skeleton is excellent, and (A) durability against atomic oxygen, (B) sunlight absorption rate due to atomic oxygen, ultraviolet rays, and electron beams. (C) vertical infrared emissivity increase suppression by atomic oxygen, ultraviolet rays, and electron beams, (D) outgas suppression, (E) surface non-adhesiveness, (F) heat yellowing, (G ) adhesion strength and (H) transparency.

The cyclic silanol (A1) contained in the silanol composition of the present embodiment preferably contains a cyclic silanol represented by formula (1). By including the cyclic silanol represented by the formula (1), the silanol composition has (A) durability against atomic oxygen, (B) suppression of increase in solar absorptance due to atomic oxygen, ultraviolet rays, and electron beams, (C) vertical infrared emissivity increase suppression by atomic oxygen, ultraviolet rays, and electron beams, (D) outgassing suppression, (E) surface non-adhesiveness, (F) heat yellowing, (G) adhesion, and (H) tend to be more excellent in transparency.

In formula (1), R ¹ to R ⁴ each independently represents a fluorine atom, an aryl group, a vinyl group, an allyl group, or a fluorine-substituted linear or branched alkyl group having 1 to 4 carbon atoms. , or an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms.

Examples of aryl groups include phenyl groups and naphthyl groups. Examples of fluorine-substituted linear or branched alkyl having 1 to 4 carbon atoms include the following groups.
CF ₃ −,
CF ₃ CF ₂ −,
_{CF3CF2CF2- , _}
(CF ₃ ) ₂ CF−,
_{CF3CF2CF2CF2- , _ _
HCF2CF2CF2CF2- , _ _
( CF3} ) _2CFCF2-

Examples of unsubstituted straight-chain or branched C 1-4 alkyl include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl and the like.

R ¹ to R ⁴ in the present embodiment each independently represent a fluorine-substituted linear or branched chain from the viewpoint of imparting heat-resistant yellowing to the cured product of the silanol composition at higher temperatures. It is preferably an alkyl group having 1 to 4 carbon atoms, or an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms, and an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms. An alkyl group is more preferred, and a methyl group is even more preferred.

The silanol composition of the present embodiment preferably has a haze of 10% or less, more preferably 5% or less, and even more preferably 2% or less (preferably 1%). When the haze of the silanol composition is 10% or less, the cured product of the silanol composition is excellent in transparency and adhesive strength. In addition, since the haze of the silanol composition is 10% or less, the silanol composition has (A) durability against atomic oxygen, and (B) suppression of increase in sunlight absorptance due to atomic oxygen, ultraviolet rays, and electron beams. , (C) vertical infrared emissivity increase suppression by atomic oxygen, ultraviolet rays, and electron beams, (D) outgas suppression, (E) surface non-adhesiveness, (F) heat yellowing, (G) adhesive strength and (H) tend to be more excellent in transparency. The haze used herein refers to the haze obtained when the silanol composition is dried by the method described later in Examples to form a film having a thickness of 3 μm.

As a method for making the haze of the silanol composition 10% or less, for example, the ratio of the isomer in the cyclic silanol (A1) represented by the formula (I) is adjusted to reduce the ratio of the highly crystalline isomer. method, a method of suppressing the amount of metal contained in the composition, and the like.

Specifically, the haze of the silanol composition can be measured by the method described in Examples.

The silanol composition of the present embodiment contains a dehydration condensate of cyclic silanol represented by formula (I). The dehydration condensate of the cyclic silanol represented by the formula (I) means that at least one of the silanol groups possessed by the cyclic silanol represented by the formula (I) is replaced by at least one other cyclic silanol represented by the formula (I). It is a compound obtained by dehydration condensation with at least one silanol group in a silanol molecule to form a siloxane bond.

For example, when the cyclic silanol represented by formula (I) is a cyclic silanol represented by formula (1), the dehydration condensate of the cyclic silanol represented by formula (1) is represented by the following formula ( 7).

In formula (7), each of the four R's is independently any one of R ¹ to R ⁴ in formula (1), and is a fluorine atom, an aryl group, a vinyl group, an allyl group, or a straight chain substituted with fluorine. linear or branched alkyl having 1 to 4 carbon atoms, or unsubstituted linear or branched alkyl having 1 to 4 carbon atoms, and m is an integer of 2 or more. Any silanol group may be used as the dehydration-condensing silanol group in the cyclic silanol. At this time, in the dehydration condensate represented by formula (7), two or more siloxane bonds may be formed between two or more cyclic silanol structures. Preferred groups for R in formula (7) include the same preferred groups as the groups R ¹ to R ⁴ .

Specific examples of the dehydration condensate of cyclic silanol represented by formula (1) include the following compounds. However, the dehydration condensate of cyclic silanol represented by formula (1) is not limited to the following compounds.

The orientation of the hydroxy group (—OH) and the R group with respect to the cyclic silanol skeleton in the following compounds is not particularly limited. Each R in the following compounds is independently any one of R ¹ to R ⁴ in formula (1). Furthermore, preferred groups for R in the following compounds include the same preferred groups as the groups R ¹ to R ⁴ .

In the dehydrated condensate of cyclic silanol represented by formula (1), the molecular weight calculated by gel permeation chromatography is preferably 500 to 1,000,000, more preferably 500 to 100,000. Yes, more preferably 500 to 10,000.

In the silanol composition of the present embodiment, as measured by gel permeation chromatography, the area of the dehydrated condensate (A2) is, with respect to the total area of the cyclic silanol (A1) and the dehydrated condensate (A2), It is preferably more than 0% and 50% or less. The area of each compound determined by gel permeation chromatography represents the content of each compound in the silanol composition.

When the area of A2 is within the above range, an increase in viscosity can be suppressed during production of the silanol composition. Further, when the area of A2 is within the above range, when the silanol composition contains an organic solvent and water, the organic solvent and water tend to be easily removed from the silanol composition.

The area of A2 is more preferably more than 0% and 40% or less, and even more preferably more than 0% and 25% or less.

The area of A2, ie, the content of A2, can be controlled by, for example, purification after the oxidation reaction when oxidizing a hydrosilane compound to obtain a cyclic silanol in the production of a silanol composition.

The area of A1 and A2, that is, the content of A1 and A2 can be measured by gel permeation chromatography, specifically by the method described in Examples.

The silanol composition of this embodiment can be prepared, for example, by oxidizing a hydrosilane compound in the presence of water or alcohol. Any hydrosilane compound can be used as long as it is a tetrasubstituted tetracyclosiloxane containing hydrogen, and commercially available products can be used.

The hydrosilane compound is preferably a tetrasubstituted tetracyclosiloxane represented by formula (8) below.

In formula (8), R ¹ to R ⁴ have the same definitions as R ¹ to R ⁴ in formula (1) and are each independently substituted with a fluorine atom, an aryl group, a vinyl group, an allyl group or fluorine. It is a linear or branched C 1-4 alkyl group or an unsubstituted linear or branched C 1-4 alkyl group.

Specific examples of cyclic hydrosilanes include tetramethyltetracyclosiloxane and the like.

Generally, the cyclic hydrosilanes do not have hydroxy or alkoxy functional groups, although such functional groups may be included in some amount prior to the oxidation reaction.

Methods for oxidizing the hydrosilane compound include, for example, methods using a catalyst and/or an oxidizing agent.

As catalysts, for example, metal catalysts such as Pd, Pt and Rh can be used. These metal catalysts may be used singly or in combination of two or more. Moreover, these metal catalysts may be carried on a carrier such as carbon.

As the oxidizing agent, for example, peroxides and the like can be used. Any peroxides can be used, and examples include oxiranes such as dimethyldioxirane.

As a method of oxidizing the hydrosilane compound, a method of oxidizing the hydrosilane compound using Pd/carbon is preferable from the viewpoint of excellent reactivity and easy removal of the catalyst after the reaction.

Cyclic silanols prepared by oxidizing a hydrosilane compound in the presence of water or alcohol contain various isomers derived from cis and trans hydrogen atoms of the starting SiH groups due to their cyclic structures.

The cyclic hydrosilane compound represented by the above formula (8) can be obtained by hydrolysis of chlorosilane or equilibrium polymerization reaction of polymethylsiloxane, but it is difficult to control the ratio of cis- and trans-derived isomers. Therefore, cyclic hydrosilane compounds contain various cis- and trans-derived isomers. The cis and trans of the cyclic hydrosilane compound in the present embodiment means that two adjacent hydroxy groups or two adjacent R groups are in the same orientation with respect to the cyclic siloxane skeleton (cis), and two adjacent hydroxy groups or two adjacent R groups are in different orientations (trans) with respect to the cyclic siloxane backbone.

The isomer contained in the cyclic silanol produced by the oxidation reaction described above includes an all-cis type cyclic silanol (B1) represented by the following formula (2). In the all-cis type cyclic silanol (B1), all hydroxy groups and R ¹ to R ⁴ groups are arranged in the same direction with respect to the cyclic siloxane skeleton, as shown by formula (2).

In formula (2), R ¹ to R ⁴ each independently represents a fluorine atom, an aryl group, a vinyl group, an allyl group, a fluorine-substituted linear or branched alkyl having 1 to 4 carbon atoms, Alternatively, it is an unsubstituted straight-chain or branched alkyl having 1 to 4 carbon atoms.

Due to the all-cis type cyclic silanol (B1) represented by the formula (2), the cyclic silanol synthesized from the cyclic hydrosilane compound by an oxidation reaction tends to become cloudy. This phenomenon is considered to be due to the crystallinity of the all-cis type cyclic silanol (B1), and is particularly noticeable during storage or when stored frozen at -30°C. By removing highly crystalline cyclic silanol, the silanol is prevented from crystallizing and precipitating in the silanol composition, and a highly transparent silanol composition can be obtained, and a highly transparent cured product can also be obtained. can. In addition, the removal of the highly crystalline cyclic silanol improves the adhesion of the silanol composition.

From the viewpoint of obtaining a silanol composition with even better transparency, it is preferable to keep the proportion of the cyclic silanol (B1) low.

As a method of suppressing the ratio of cyclic silanol (B1), for example, a method of combining recrystallization operation and removal of crystals can be mentioned.

More specifically, the cyclic silanol (B1) precipitates as crystals by adding a poor solvent to a good solvent solution of the product obtained in the synthesis of the cyclic silanol. By removing the precipitated cyclic silanol (B1) and concentrating the solution of the soluble portion, the ratio of the cyclic silanol (B1) in the silanol composition can be suppressed and a highly transparent silanol composition can be obtained.

When performing the recrystallization operation, the cooling temperature is preferably less than 10°C from the viewpoint of obtaining a silanol composition with even better transparency. From the viewpoint of improving the yield of cyclic silanol, the amount (volume) of the poor solvent is preferably equal to or more than the amount of the good solvent and 20 times or less.

The good solvent is not particularly limited, and examples thereof include tetrahydrofuran, diethyl ether, acetone, methanol, ethanol, isopropanol, dimethylformamide, dimethylsulfoxide, glycerin, ethylene glycol, methyl ethyl ketone and the like. These good solvents may be used singly or in combination of two or more.

The poor solvent is not particularly limited, and examples thereof include toluene, chloroform, hexane, dichloromethane, xylene and the like. These poor solvents may be used singly or in combination of two or more.

The proportion of cyclic silanol (B1) can be calculated by ¹ H-NMR measurement of the cyclic silanol obtained by synthesis. Specifically, in ¹ H-NMR measurement, hydrogen contained in R ¹ to R ⁴ groups of cyclic silanol (B1) is different from hydrogen in R ¹ to R ⁴ groups of other isomers of cyclic silanol. On the other hand, it is observed at the highest magnetic field side. Therefore, the ratio of cyclic silanol (B1) is calculated from the integrated value of these hydrogens.

When a metal catalyst is used to oxidize the hydrosilane compound, the transition metal contained in the metal catalyst remains in the insoluble residue due to the above-described recrystallization operation. The proportion of metal can be reduced. Therefore, the operation for removing the cyclic silanol represented by the formula (2) also makes it possible to reduce the coloring of the silanol due to the residual metal catalyst.

From the viewpoint of further improving the light transmittance of the silanol composition, the proportion of the transition metal is preferably less than 1 mass ppm with respect to the total mass of the silanol composition.

Specifically, the ratio of transition metals can be measured by the method described in Examples.

The transition metal is not particularly limited, and examples thereof include palladium.

Cyclic silanols (A1) preferably contain cyclic silanols (B1) to (B4) represented by the following formulas (2) to (5). In particular, when a tetrasubstituted tetracyclosiloxane represented by formula (8) is used as a raw material and oxidized as a hydrosilane compound, the resulting tetrahydroxytetrasubstituted tetracyclosiloxane is represented by the following formulas (2) to (5). The represented cyclic silanols (B1) to (B4) may be mixed, preferably consisting of cyclic silanols (B1) to (B4). As a result, (H) excellent transparency of the cured product, (G) excellent adhesive strength of the cured product, (A) atomic oxygen durability, (B) atomic oxygen, ultraviolet rays, and solar radiation due to electron beams (C) suppression of increase in vertical infrared emissivity due to atomic oxygen, ultraviolet rays, and electron beams, (D) suppression of outgassing, (E) surface non-adhesiveness, and (F) heat yellowing It tends to be more resistant to denaturation.

In formulas (2) to (5), R ¹ to R ⁴ each independently represent a fluorine atom, an aryl group, a vinyl group, an allyl group, or a fluorine-substituted linear or branched chain having 1 to 1 carbon atoms. 4 alkyl group, or an unsubstituted linear or branched C 1-4 alkyl group.

Preferred groups for R ^{1 to R 4 in formulas (2) to (5) are the same as the preferred groups for R 1 to R 4 in formula} (1).

The cyclic silanols (A1) in the present embodiment contain cyclic silanols (B1) to (B4) represented by the formulas (2) to (5), and the total amount of the cyclic silanols (B1) to (B4) is It is preferable to satisfy 0<b≦20, where b is the proportion (mol %) of the cyclic silanol (B2). As a result, (A) atomic oxygen durability, (B) solar absorption rate increase suppression property due to atomic oxygen, ultraviolet rays, and electron beams, and (C) vertical infrared radiation due to atomic oxygen, ultraviolet rays, and electron beams (D) outgas suppression, (E) surface non-tackiness, and (F) heat yellowing resistance.

As a method for setting the ratio b to 0<b≦20, for example, a method of combining the recrystallization operation and the removal of crystals can be used, as described above.

When tetramethyltetracyclosiloxane was used as a starting material as a hydrosilane compound and oxidized, ¹ H-NMR of the resulting tetrahydroxytetramethyltetracyclosiloxane was measured, and six peaks of four isomers were observed. (Here, three types of peaks are observed for trans-trans-cis.). Hydrogen in R ¹ to R ⁴ is, from the high magnetic field side, all-cis (cyclic silanol (B1)), trans-trans-cis (cyclic silanol (B3)), trans-trans-cis (cyclic silanol (B3) ), cis-trans-cis (cyclic silanol (B2)), all-trans (cyclic silanol (B4)), trans-trans-cis (cyclic silanol (B3)) types are observed in this order, so the integral of such hydrogen From the values, the ratio of each of the cyclic silanols (B1) to (B4) is calculated.

Since the cyclic silanol (B2) represented by the formula (3) also has crystallinity, when a good solvent is used in the reaction solution, addition of a poor solvent causes precipitation as crystals. The synthesized cyclic silanol (A1) tends to become cloudy due to the cyclic silanol (B2). This phenomenon is considered to be due to the fact that the cis-trans-cis type cyclic silanol (B2) has crystallinity, and is particularly noticeable during storage or when stored frozen at -30°C.

From the viewpoint of obtaining a silanol composition with even better transparency, the ratio of the cyclic silanol (B2) is preferably 0% to 50%, more preferably 0%, relative to the cyclic silanol represented by formula (1). % to 40%, more preferably 0 to 35%, particularly 0% or more and less than 35%.

As described above, the silanol composition of the present embodiment is prepared by oxidizing a hydrosilane compound in the presence of water or alcohol to prepare a cyclic silanol, and a good solvent solution of the product obtained by the synthesis of the cyclic silanol It is preferably produced by adding a poor solvent to recrystallization, filtering, and concentrating the solution of the soluble portion obtained by filtering.

In the production of the silanol composition of the present embodiment, the concentration of the soluble portion solution may be optionally performed, and the soluble portion solution itself may be used as the silanol composition. In addition, since it is not necessary to remove all the solvent contained in the solution in concentrating the soluble part solution, the silanol composition of the present embodiment distills off part of the solvent contained in the soluble part solution. It may be a crude concentrate obtained by Furthermore, the silanol composition of the present embodiment may be obtained by concentrating the solution of the soluble portion and then re-diluting it with a solvent. As described above, one of the preferred aspects of this embodiment is a silanol composition containing a solvent.

In this case, the amount of the solvent contained in the silanol composition is preferably 95% by mass or less, more preferably 90% by mass or less, and still more preferably 85% by mass or less, relative to the total amount of the silanol composition. The lower limit of the amount of solvent is not particularly limited, and is, for example, 1% by mass or more.

Solvents in the solvent-containing silanol composition include water and/or alcohol used in the reaction, good solvents and poor solvents used in recrystallization, and the like. The solvent is not particularly limited, and examples thereof include water, tetrahydrofuran, diethyl ether, acetone, methanol, ethanol, isopropanol, dimethylformamide, dimethylsulfoxide, glycerin, ethylene glycol, methyl ethyl ketone, toluene, chloroform, hexane, dichloromethane, and xylene. mentioned. These solvents may be used singly or in combination of two or more.

The silanol composition of the present embodiment preferably further contains silica particles having an average particle size of 1 nm or more and 100 nm or less.

When the average particle size of the silica particles is 1 nm or more, the abrasion resistance tends to be excellent. In addition, when the average particle size of the silica particles is 100 nm or less, it tends to be excellent in transparent dispersibility.

The average particle size of the silica particles is preferably 1 nm or more and 50 nm or less, more preferably 2 nm or more and 30 nm or less, and still more preferably 5 nm or more and 20 nm or less.

The average particle size of silica particles can be measured by dynamic light scattering measurement.

The form of the silica particles having an average particle size of 1 nm or more and 100 nm or less is not particularly limited as long as the transparency of the silanol composition of the present embodiment can be maintained. The silica particles are not particularly limited, and examples thereof include a form of a normal aqueous dispersion, a form dispersed in an organic solvent, and the like. Among these, the silica particles are preferably colloidal silica dispersed in an organic solvent from the viewpoint of uniform and stable dispersion in the silanol composition.

The organic solvent for dispersing silica particles is not particularly limited, and examples include methanol, isopropyl alcohol, n-butanol, ethylene glycol, xylene/butanol, ethyl cellosolve, butyl cellosolve, dimethylformamide, dimethylacetamide, methyl ethyl ketone, methyl isobutyl ketone, and the like. is mentioned.

Among these, from the viewpoint of uniformly dispersing the silica particles in the silanol composition, the organic solvent is preferably an organic solvent capable of dissolving the silanol composition.

The colloidal silica in the form dispersed in an organic solvent is not particularly limited, and examples thereof include methanol silica sol MA-ST, isopropyl alcohol silica sol IPA-ST, n-butanol silica sol NBA-ST, ethylene glycol silica sol EG-ST, xylene/ Butanol Silica Sol XBA-ST, Ethyl Cellosolve Silica Sol ETC-ST, Butyl Cellosolve Silica Sol BTC-ST, Dimethylformamide Silica Sol DBF-ST, Dimethylacetamide Silica Sol DMAC-ST, Methyl Ethyl Ketone Silica Sol MEK-ST, Methyl Isobutyl Ketone Silica Sol MIBK-ST (manufactured by Nissan Chemical Co., Ltd.).

When the silanol composition of the present embodiment further contains silica particles having an average particle size of 1 nm or more and 100 nm or less, the silanol composition can be suitably produced as follows. That is, cyclic silanols are prepared by oxidizing hydrosilane compounds in the presence of water or alcohol. Next, recrystallization and filtration are performed by adding a poor solvent to the good solvent solution containing the product obtained in the synthesis of the cyclic silanol. Next, the solution of the soluble portion obtained by filtration is concentrated, and silica particles having an average particle size of 1 nm or more and 100 nm or less or the silica particle dispersion are added.

The content of the silica particles in the silanol composition of the present embodiment is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, based on the total amount of solids in the silanol composition, More preferably, it is 30 to 60% by mass.

When the content of the silica particles is 10% by mass or more, the cured product tends to be excellent in abrasion resistance. Moreover, when the content of the silica particles is 80% by mass or less, the cured product tends to be excellent in transparency.

Here, the total amount of solids in the silanol composition is, for example, the total amount of the cyclic silanol (A1) and the silica particles.

It is preferable that the silanol composition of the present embodiment further includes a both-terminated silanol-modified siloxane represented by the following formula (6). As a result, (H) the transparency of the cured product and (G) the adhesive strength of the cured product are further excellent, and (A) the durability of atomic oxygen and (B) the absorption of sunlight by atomic oxygen, ultraviolet rays, and electron beams. (C) vertical infrared emissivity increase suppression by atomic oxygen, ultraviolet rays, and electron beams, (D) outgas suppression, (E) surface non-adhesiveness, and (F) heat yellowing It tends to be better.

In formula (6), each R' is independently a fluorine atom, an aryl group, a vinyl group, an allyl group, a fluorine-substituted linear or branched alkyl group having 1 to 4 carbon atoms, or , an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms, and m is an integer of 0 to 1,000.

In formula (6), R' is preferably an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms, more preferably an unsubstituted 1 carbon atom, from the viewpoint of suppressing thermal decomposition. 1 to 2 alkyl groups, more preferably an unsubstituted methyl group.

From the viewpoint of compatibility with the cyclic silanol (A1), the molecular weight of the silanol-modified siloxane at both ends represented by the formula (6) is preferably 10,000 or less, more preferably 5,000 or less, and even more preferably 3,500. It is below.

From the viewpoint of suppressing volatilization, the molecular weight of the silanol-modified siloxane represented by the formula (6) is preferably 200 or more, more preferably 300 or more, and still more preferably 400 or more.

The molecular weight of the silanol-modified siloxane at both ends represented by formula (6) can be measured by gel permeation chromatography (GPC).

The silanol-modified siloxane at both ends is not particularly limited. Examples include 1,1,3,3-tetramethyldisiloxanediol-1,3-diol, 1,1,3,3,5,5-hexamethyldi Siloxane-1,5-diol, 1,1,3,3,5,5,7,7-octamethyltetrasiloxane-1,7-diol, 1,1,3,3,5,5,7,7 ,9,9-decamethylpentasiloxane-1,9-diol, diol-modified polymethyldimethyldisiloxane at both ends, and the like. Both terminal silanol-modified siloxanes may be used alone or in combination of two or more.

A commercially available product may be used as the silanol-modified siloxane at both ends. Commercially available products are not particularly limited, and for example, X21-5841, KF9701 (manufactured by Shin-Etsu Chemical), and DMS-S12, DMS-S14, DMS-S15, DMS-S21, DMS-S27, DMS-S31, DMS -S32, DMS-S33, DMS-S35, DMS-S42, DMS-S45, DMS-S51 (manufactured by Gelest) and the like.

The content of the both-terminated silanol-modified siloxane in the silanol composition of the present embodiment is preferably 1 to 80% by mass, more preferably 10 to 60% by mass, more preferably 10 to 60% by mass, based on the amount of the silanol composition. 15 to 50% by mass.

When the content of the silanol-modified siloxane at both ends is 1% by mass or more, the resulting cured product of the silanol composition tends to be more excellent in crack resistance. Moreover, when the content of the silanol-modified siloxane at both ends is 80% by mass or less, the silanol composition tends to further improve the transparency of the resulting cured product.

The silanol composition of the present embodiment preferably has a total content (total content) of sodium (Na) and vanadium (V) of less than 60 mass ppm.

When the total content is less than 60 ppm by mass, the silanol composition of the present embodiment tends to be even more excellent in storage stability.

The content ratio is preferably 20 mass ppm or less, more preferably 12 mass ppm or less, still more preferably 2 mass ppm or less, and particularly preferably 1 mass ppm or less, from the viewpoint of better storage stability. be.

The content of each of Na and V in the silanol composition of the present embodiment is preferably less than 30 ppm by mass, more preferably 10 ppm by mass or less, and still more preferably, from the viewpoint of better storage stability. It is 6 mass ppm or less, and particularly preferably 1 mass ppm or less.

The method for controlling the total content to less than 60 ppm by mass is not particularly limited, and for example, a method of using powdered cellulose as a filter aid in the filtration step when producing the silanol composition of the present embodiment. mentioned.

Commercial products of powdered cellulose are not particularly limited, and examples thereof include KC Flock W50GK (manufactured by Nippon Paper Industries), KC Flock W100-GK (manufactured by Nippon Paper Industries), cellulose powder 38 μm (400 mesh) passing (manufactured by Wako Pure Chemical Industries), and the like. mentioned.

Methods for controlling the total content to less than 60 ppm by mass include, in addition to the methods described above, a method using a filter aid that does not contain Na and V, and the like.

The respective content ratios of Na and V in the silanol composition can be measured according to the methods described in Examples below.

(cured product)
The cured product of this embodiment is a cured product obtained by curing the silanol composition of this embodiment. The cured product of this embodiment is used for radiation resistance or outer space. The cured product of the present embodiment is obtained by forming siloxane bonds (-Si-O-Si-) by dehydration condensation reaction of silanol groups (-Si-OH) contained in the silanol composition of the present embodiment. . The cured product of this embodiment is insoluble in solvents such as tetrahydrofuran and toluene.

In order to obtain the cured product of this embodiment, for example, the silanol composition of this embodiment may be cured by a known method.

Cyclic silanol (A1) may be polymerized in the absence of a catalyst, or may be polymerized with the addition of a catalyst.

The catalyst used in the polymerization of cyclic silanols acts to promote hydrolysis and condensation reactions of cyclic silanols. As a catalyst, an acid catalyst or an alkali catalyst can be used.

Acid catalysts are not particularly limited, and examples include hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, hydrofluoric acid, formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, fluoroacetic acid, oxalic acid, malonic acid, sulfonic acid, phthalic acid, fumaric acid, citric acid, maleic acid, oleic acid, methylmalonic acid, adipic acid, p-aminobenzoic acid, and p-toluenesulfonic acid. .
Examples of the alkali catalyst include, but are not limited to, inorganic bases such as sodium hydroxide, potassium hydroxide, sodium hydrogencarbonate, sodium carbonate, ammonium carbonate, ammonium hydrogencarbonate, aqueous ammonia, and organic amines.

Each of the acid catalyst and the alkali catalyst may be used alone or in combination of two or more.

The amount of the catalyst to be added can be adjusted depending on the reaction conditions, and is preferably 0.000001 to 2 mol per 1 mol of the hydroxyl group of the cyclic silanol. If the amount added exceeds 2 mol per 1 mol of the hydroxyl group of the cyclic silanol, the reaction rate is very high even at a low concentration, making it difficult to control the molecular weight and gels tend to occur.

When obtaining a cured product, the cyclic silanol in the silanol composition can be hydrolyzed and condensed in stages using an acid catalyst and an alkali catalyst. Specifically, the cyclic silanols in the silanol composition are hydrolyzed and condensed with an acid and then reacted again with a base, or the cyclic silanols are first hydrolyzed and condensed with a base and then acid again. A cured product can be obtained by reacting them. A silanol composition can also be obtained by reacting an acid catalyst and an alkali catalyst, respectively, and then mixing the condensates.

A method for curing the silanol composition of the present embodiment is not particularly limited, and includes a method of curing by heating.

The curing temperature for curing the cured product is preferably 60 to 250°C, more preferably 80 to 200°C.

Curing time for curing the silanol composition of the present embodiment (for example, heat curing time for heat curing) is preferably 10 minutes to 72 hours, more preferably 10 minutes to 48 hours, and still more preferably 30 minutes. to 48 hours (preferably 1 to 24 hours, more preferably 1 to 12 hours).

The silanol composition of this embodiment can be used as an adhesive. The adhesive of the present embodiment contains the silanol composition of the present embodiment and is a radiation-resistant or outer space adhesive. The silanol composition of the present embodiment is applied to a substrate to form an adhesive layer, and the adhesive layer containing the silanol composition is cured to adhere. The substrate is not particularly limited, and examples thereof include glass, silicon wafers, _SiO2 wafers, SiN wafers, compound semiconductors, resins, electronic substrates, resins, metals, inorganic substances, organic substances, polymers and the like.

(composite membrane)
The composite film of this embodiment includes a film and the cured product of this embodiment placed on the film, and is used for radiation resistance or outer space applications.

The film used for the composite membrane of the present embodiment is not particularly limited, and includes materials used as known films, and among these, a polyimide film is preferable.

The polyimide film is not particularly limited. Various apicals), 3,3′,4,4′-biphenyltetracarboxylic dianhydride as a monomer and at least polycondensation (Ube Industries Ltd.: Upilex-R, Upilex-S), and the like.

The thickness of the polyimide film is preferably 7.5-125 μm.

In addition, the polyimide film may be subjected to discharge treatment such as plasma discharge treatment or corona discharge treatment, or surface treatment such as alkali treatment, in order to improve adhesiveness.

The method for forming the film is not particularly limited, and is appropriately selected according to the constituent material, shape, and the like of the base material. When the substrate is in the form of a flat plate such as a film or sheet, the coating may be formed using an applicator, bar coater, wire bar coater, roll coater, curtain flow coater, or the like. mentioned. Other forming methods include a dip coating method, a scat method, a spray method, and the like.

EXAMPLES The present invention will be described in more detail using Examples and Comparative Examples, but the present invention is not limited to these Examples and the like. Methods for measuring physical properties and evaluating properties of the silanol compositions obtained in the present invention and the following examples and comparative examples are as follows.

[Evaluation method]
<Atomic Oxygen Irradiation Test and Atomic Oxygen Durability Test>
Using an atomic oxygen (AO) irradiation device (FAST atomic oxygen irradiation device manufactured by PSI), a bar coater No. 32 was coated with a 32 mass % isopropanol solution of a silanol composition on the surface of a polyimide film as a base material. 6, vacuum drying was performed at 60° C., and the test piece was cured at 100° C. for 2 hours and 120° C. for 3 hours, and then irradiated with atomic oxygen.
Beam velocity: 8km・s ^-1
Beam velocity: 3×10 ¹⁵ cm ^-2 s ^-1
Degree of vacuum: 10 ^-6 to 10 ^-7 Pa when not irradiated (when irradiated) 10 ^-3 Pa Irradiation conditions:
AO average flow velocity: 3×15 ¹⁵ atoms·cm ⁻¹ ·s ⁻¹
AO speed: 8.11 km/s ^-1
Irradiation time: 27.5 hours Irradiation amount: 3×12 ²⁰ atoms·cm ⁻¹
Irradiation temperature: 22 degrees Irradiation degree of vacuum: 2.0×10 ^-2 to 2.3×10 ^-2
The amount of change in the mass of the cured product before and after the irradiation of atomic oxygen was measured by placing the mass of the test piece, including the base material, in an environment with a temperature of 23 ° C and a humidity of 50% for 6 hours or more. (Mettler Toledo Co., Ltd., micro balance XP6) was calculated according to the following formula.
Mass change (mg) = test piece mass after irradiation - test piece mass before irradiation Based on the value divided by the area (mm ² ), evaluation was made according to the criteria shown below.
○ indicates that it was 1.0×10 ⁻⁵ (mg/mm ² ) or less.
x indicates that it was over 1.0×10 ⁻⁵ (mg/mm ² ).
O indicates excellent resistance to exposure to atomic oxygen, and X indicates poor resistance to exposure to atomic oxygen.

<Ultraviolet irradiation test>
A 32% by mass isopropanol solution of a silanol composition was applied to the upper surface of the polyimide film using a bar coater No. 1 using an ultraviolet irradiation device. 6, vacuum dried at 60° C., cured at 100° C. for 2 hours, and then cured at 120° C. for 3 hours, and then irradiated with ultraviolet (UV) rays under the following conditions.
Ultraviolet region light intensity: 1 to 10 solar (at 400 nm or less)
Focal length: 400mm-450mm
Light source: Type UXL-5001YA (manufactured by Ushio) 5kWXe short arc lamp Irradiation: 50ESD
Irradiation rate: 10ESD/day
Irradiation temperature: -10°C to -9°C
Irradiation vacuum degree: 1.6 × 10 ^-4 Pa
Mirror: dichroic mirror

<Electron beam irradiation test>
An electron beam irradiation device (EB500, manufactured by Nissin Electric Co., Ltd.) was used as an electron irradiation device, and a 32% by mass isopropanol solution of a silanol composition was applied to the upper surface of the polyimide film using a bar coater No. 1. 6, vacuum dried at 60° C., cured at 100° C. for 2 hours, and then cured at 120° C. for 3 hours, and electron beam (EB) irradiation was performed under the following conditions.
Accelerating voltage: 500 kV
Irradiation time: 2949 sec
EB irradiation dose: 500 kGy
Electron current: 2.0mA
Time Rating: Continuous Temperature: 22°C
Acceleration tube vacuum: 1.7×10 ⁻⁵ to 4.5×10 ⁻⁵ Pa

<Evaluation of sunlight absorption rate>
The solar absorptance (αs) of the cured product was measured using a solar absorptance measuring device (a spectrophotometer U-4100 manufactured by Hitachi High-Technologies Co., Ltd. equipped with a Spectralon-coated integrating sphere). The solar absorptivity (αs) was measured before and after irradiation with atomic oxygen, ultraviolet rays, and electron beams under the conditions of .
Scanning wavelength: 240-2,800 nm
Measurement method: Double beam direct ratio photometry Scanning width: 1 nm
Wavelength accuracy: UV/visible range ±0.2 nm, near infrared range ±1.0 nm
Detector: photomultiplier tube/lead sulfide element UV resistance test evaluation (solar absorption rate evaluation) is the difference in solar absorption rate (αs) before and after AO irradiation, electron beam irradiation, or UV irradiation. Numerical values were calculated according to the following formula and evaluated according to the criteria shown below.
Change in solar absorptance = solar absorptance of test piece after irradiation - solar absorptance of test piece before irradiation ◯ indicates ±1.0×10 ⁻¹ or less.
X indicates that it exceeded ±1.0×10 ⁻¹ .
◯ indicates excellent suppression of increase/decrease in solar absorptance, and x indicates poor suppression of increase/decrease in solar absorptance due to ultraviolet rays.

<Vertical infrared emissivity (ε _N ) measurement>
The vertical infrared emissivity (ε _N ) of the cured product was measured using a vertical infrared emissivity (ε _N ) measuring device (AZ Technology TESA2000) under the following conditions: atomic oxygen, ultraviolet rays, And the vertical infrared emissivity (ε _N ) before and after electron beam irradiation was measured.
Wavelength range: 3 μm to 35 μm
Change in vertical infrared emissivity = vertical infrared emissivity of test piece after irradiation - vertical infrared emissivity of test piece before irradiation ◯ indicates ±1.0×10 ^-1 or less.
X indicates that it exceeded ±1.0×10 ⁻¹ .
◯ indicates excellent suppression of increase/decrease in vertical infrared emissivity, and x indicates poor suppression of increase/decrease in vertical infrared emissivity.

<Outgassing test (outgassing suppression property)>
Using a polyimide film as a base material, a 32% by mass isopropanol solution of a silanol composition was applied to the surface using a bar coater No. 1. 6, vacuum dried at 60° C., and cured at 100° C. for 2 hours and 120° C. for 3 hours to prepare a test piece, which was measured according to ASTM (American Society for Testing and Materials) E595-93 test method.
〔Measurement condition〕
Degree of vacuum: 7×10 ⁻³ Pa or less Material heating temperature: 125±1° C.
Release gas cooling temperature: 23±1°C
Retention time: 24 hours Measurement items: TML, CVCM
Initial sample weight: 200 mg to 300 mg

TML (Total Mass Loss): Mass loss ratio is defined by the following formula.
Mass loss ratio = {(Sample mass before test - Sample mass after test)/Sample mass before test} x 100 (%)
In outgassing test evaluation of TML, the value of TML was evaluated according to the criteria shown below.
○ indicates that it was 1.0% or less.
x indicates that it was over 1.0%.
○ indicates that the mass loss was the smallest and the performance was excellent, and × indicates that the mass loss was the largest and the performance was poor.

<Surface tackiness evaluation (surface non-tackiness)>
Using a polyimide film as a base material, a curable composition was applied to the surface to a thickness of 1 to 3 μm and cured. It was evaluated according to the following evaluation criteria.
○ represents that there was no surface tackiness.
x indicates that there was surface tackiness.
○ indicates that the physical properties were excellent without surface tackiness, and × indicates that the physical properties were poor with surface tackiness.

<Heat yellowing test>
A 25 μm thick PET film (Toray Industries, Inc., trade name Lumirror) is used as a base material, and a 40% by mass isopropanol solution of a silanol composition is cast and coated on the surface. A test piece was prepared by curing at 120 ° C. for 2 hours, further at 150 ° C. for 2 hours, and further at 180 ° C. for 2 hours. After the test, the transmittance at 380 nm was evaluated using a transmittance measuring device (Spectralon-coated integrating sphere installed in a spectrophotometer U-4100 manufactured by Hitachi High-Technologies Corporation).
In the evaluation of the heat yellowing test, the value of transmittance (%) was evaluated according to the criteria shown below.
○ represents that it was 50% or more.
× indicates that it was less than 50%.
O indicates the least recondensation and excellent performance, and X indicates the most recondensation and poor performance.

<Calculation of mass percent concentration of coating solution>
Using ECZ400S manufactured by JEOL Ltd. and a TFH probe as a probe, NMR measurement was performed as follows.
For example, in the case of an isopropanol solution of tetrahydroxytetramethyltetracyclosiloxane and its polymer, a sample obtained by adding ¹ g of heavy acetone to 0.1 g of an isopropanol solution of tetrahydroxytetramethyltetracyclosiloxane and its polymer was used. 1 H-NMR was measured. The reference peak of the heavy solvent was set to 2.05 ppm, and the measurement was performed with 64 integration times.
The mass percent concentration of tetrahydroxytetramethyltetracyclosiloxane and its polymer can be approximately calculated by the following formula.
Mass percent concentration of tetrahydroxytetramethyltetracyclosiloxane and its polymer = (Peak integral ratio of methyl groups bonded to Si in the region of -0.1-0.3 ppm / 12 × 304.51) / {(-0 .1-0.3 ppm peak integration ratio of methyl group bonded to Si/12×304.51) + (3.7-4.1 ppm region of isopropanol peak integrated value of hydrogen bonded to carbon/ 1×60.1)}
In the above formula, 304.51 means the molecular weight of tetrahydroxytetramethyltetracyclosiloxane, and 60.1 means the molecular weight of isopropanol.

<Measurement of haze>
Haze was measured based on JISK7136 using a turbidity meter NDH5000W (manufactured by Nippon Denshoku Industries). Specific operations are shown below.
The haze of the silanol composition was measured by applying a 42 mass % isopropanol solution of the silanol composition to a plain glass substrate of 5 cm x 5 cm x 0.7 mm thickness (manufactured by Technoprint Co., Ltd.) using a bar coater No. 1. 40 (manufactured by AS ONE) and dried under reduced pressure at 60° C. for 1 hour, and the haze was measured. As a blank for haze measurement, only a plain glass substrate of 5 cm x 5 cm x 0.7 mm thickness (manufactured by Technoprint Co., Ltd.) was used.
For Examples 10, 16 and Comparative Example 1, the haze of the silanol composition after 24 hours was also measured.
The haze of the cured product was measured using a sample obtained by heating the sample prepared for haze measurement of the silanol composition at normal pressure at 100° C. for 2 hours.

<Measurement of film thickness>
The film thickness was calculated by measuring a sample prepared for haze measurement with a surface profile measuring instrument (manufacturer name: Kosaka Laboratory Model: ET4000AK31).

<Confirmation of adhesive strength>
A T-3000-FC3 manual die bonder (manufactured by TRESKY) was used to place a hemispherical quartz lens with a diameter of 2 mm on a sample prepared by haze measurement of a silanol composition with a load of 400 g for 3 seconds. Then, after heating at 100° C. for 2 hours under normal pressure, the obtained glass on which the hemispherical lens was placed was pressed from the side to confirm the presence or absence of adhesion.

<Measurement of Area Ratio (%) of Dehydrated Condensate (A2)>
A measurement sample was prepared by dissolving 0.03 g of the silanol composition in 1.5 mL of tetrahydrofuran.
Using this measurement sample, measurement was performed with Tosoh's HLC-8220GPC.
As the column, TSK guard columns SuperH-H, TSKgel SuperHM-H, TSKgel SuperHM-H, TSKgel SuperH2000, and TSKgel SuperH1000 manufactured by Tosoh Corporation were connected in series, and tetrahydrofuran was used as the mobile phase at a rate of 0.35 ml/min. analyzed.
An RI detector was used as a detector, and polymethyl methacrylate standard samples manufactured by American Polymer Standards Corporation (molecular weight: 2100000, 322000, 87800, 20850, 2000, 670000, 130000, 46300, 11800, 860), and 1,3,5 , 7-tetramethylcyclotetrasiloxane (molecular weight 240.5, manufactured by Tokyo Chemical Industry Co., Ltd.) as a standard substance, the number average molecular weight and weight average molecular weight are determined, p = 0 and p ≥ 1 peaks are specified, and cyclic silanol ( The peak area ratio (%) of each of A1) and the dehydrated condensate (A2) was calculated.
From the cyclic silanol (A1) and the dehydrated condensate (A2), the area ratio (%) of the dehydrated condensate (A2) was obtained from (A2)/[(A1)+(A2)].

<Contents of Na and V, and Contents of Transition Metal (Pd)>
Fluonitric acid was added to the hydrosiloxane oxidation reaction product, and after sealed pressure acid decomposition, the sample was transferred to a Teflon (registered trademark) beaker and heated to dryness. After that, aqua regia was added to the sample, and the completely dissolved solution was adjusted to 20 mL, and quantitative analysis of the metal ratio (mass ppm) in the sample was performed using an ICP mass spectrometer (iCAP Qc manufactured by Themo Fisher Scientific). .

<Calculation of stereoisomer ratio of cyclic silanol using ¹ H-NMR measurement>
Using ECZ400S manufactured by JEOL Ltd. and a TFH probe as a probe, NMR measurement was performed as follows.
0.1 g of the product and 1 g of deuterated acetone were added to the obtained silanol composition, and ¹ H-NMR was measured. The reference peak of the heavy solvent was set to 2.05 ppm, and the measurement was performed with 64 integration times.
When tetramethyltetracyclosiloxane is used as a hydrosilane compound and oxidized, the ¹ H-NMR of the resulting tetrahydroxytetramethyltetracyclosiloxane shows four isomers in the region of 0.04-0.95 ppm. Peaks of methyl groups bonded to six types of Si derived were observed.
The hydrogen of the methyl group is all-cis type (0.057 ppm), trans-trans-cis type (0.064 ppm), trans-trans-cis type (0.067 ppm), cis-trans-cis type (0.074 ppm), all-trans type (0.080 ppm), and trans-trans-cis type (0.087 ppm) were observed in this order. Using Delta 5.2.1 (manufactured by JEOL Ltd.), the six peaks were subjected to waveform separation by Lorentz transformation, and the ratio (%) of each stereoisomer of cyclic silanol was calculated from the peak intensity of these hydrogens.

<Preparation of each stereoisomer>
・all-cis form (cyclic silanol (B1))
Synthesized according to the synthesis example of Inorganic Chemistry Vol.49, No.2, 2010.
・cis-trans-cis form (cyclic silanol (B2))
The recrystallized product obtained in Example 1 was used.
・all-trans form (cyclic silanol (B4))
The mixed solution of 10% by mass of silanol in tetrahydrofuran and dichloromethane prepared in Example 1 was further concentrated, and using the concentrated solution to 20% by mass of silanol, stereoisomers were separated using liquid chromatography under the following conditions. I sorted.
liquid chromatography conditions;
Apparatus Liquid chromatography pump manufactured by GL Sciences: PU715
Column oven: CO705
Fraction collector: FC204YMC－PackSIL-06 φ30mm×250mm
Eluent: Cyclohexane/EtoAc = 60/40
Flow rate: 40mL/min
Injection volume: 5mL
Temperature: 40℃
Detection: The obtained fraction was evaluated and detected by ELSD measurement.
All-trans crystals were obtained by allowing the obtained eluate of all-trans crystals to stand, and they were collected by filtration.
・trans-trans-cis form (cyclic silanol (B3))
The all-trans form was obtained by concentrating the eluent obtained in the same manner as for the all-trans form and substituting with isopropanol.

[Example 1]
(Preparation of silanol composition)
In a reaction vessel, 28 g of distilled water, 960 mL of tetrahydrofuran (THF, manufactured by Wako Pure Chemical Industries), and 3.7 g of Pd/C (10% palladium-carbon, manufactured by N.E. Chemcat) were added and mixed. was maintained at 5°C.
81 g of 1,3,5,7-tetramethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd., also referred to as D4H) was gradually added to the reaction vessel, and after stirring for 2 hours, the mixture was stirred until SiH groups disappeared by ¹ H-NMR. 1.8 g of Pd/C (10% palladium/carbon) was divided into three portions, and the reaction was carried out for a total of 17 hours. The disappearance of SiH groups was confirmed by measuring ¹ H-NMR of the reaction solution with a heavy acetone solution having a concentration of 1% by mass using JEOL NMR (ECZ400S) to confirm the disappearance of 4 to 5 ppm of SiH groups.
75 g of magnesium sulfate was added to the reaction solution and stirred at 5°C for 30 minutes. 545 (manufactured by Wako Pure Chemical Industries, Ltd.) (450 g) was filled into the funnel using tetrahydrofuran. Subsequently, the reaction solution is passed through the celite, the celite is washed with 1.5 L of tetrahydrofuran, and 1,3,5,7-tetrahydroxy-1,3,5,7-tetramethyltetracyclosiloxane (hereinafter referred to as 2057 g of a THF solution containing (also referred to as D4OH) was obtained. This solution was concentrated with an evaporator in a water bath of 15° C. to a residual amount of 587 g (649 mL), and poured into a mixed solvent of 4.4 L of tetrahydrofuran and 217 mL of dichloromethane. After the mixture was allowed to stand at 5° C. for 4 hours, the precipitated insoluble matter was filtered under reduced pressure to recover 22 g of a crystalline solid. 6169 g of the solubles filtrate was concentrated under reduced pressure to yield 89 g of D4OH concentrate (ie, hydrosiloxane oxidation reactant).
Furthermore, the D4OH concentrate: both terminal silanol-modified siloxane represented by the above formula (6): tetrahydrofuran is 8: 2: 90 (that is, the content of both terminal silanol-modified siloxane is 20% by mass). A silanol-modified siloxane (manufactured by Shin-Etsu Chemical Co., Ltd. X21-5841, molecular weight 1000) and tetrahydrofuran were added to the D4OH concentrate so as to obtain a silanol composition.
Using the obtained silanol composition, haze was measured according to the method described above (Measurement of haze). Also, the proportions of all-trans type and cis-trans-cis type cyclic silanols were calculated by ¹ H-NMR.
Furthermore, the content of the transition metal Pd was calculated as described above.

(Confirmation of curing of silanol composition, confirmation of adhesive strength, and measurement of light transmittance of cured product)
The silanol composition obtained in the above (Preparation of silanol composition) was coated on quartz glass with a bar coater No. 1. 2 was applied to a thickness of 3 μm, quartz glass was placed thereon, and cured with a temperature program of 80° C. for 6 hours and 180° C. for 6 hours.
After curing, only one glass plate was lifted, and after confirming that the glass was adhered, the haze of the resulting cured product was measured.

(Confirmation of crack resistance during rapid cooling after curing)
The cured product was removed from the oven at 180° C. to a room temperature of 25° C. and cooled rapidly, and the occurrence of cracks was observed under a microscope.

[Example 2]
Example 1, except that the mass ratio of D4OH concentrate: silanol-modified siloxane at both ends: tetrahydrofuran was 6:4:90 (that is, the content of silanol-modified siloxane at both ends was 40% by mass). A silanol composition was obtained in the same manner as in , and the same experiment was performed.

[Example 3]
Silanol composition in the same manner as in Example 1 except that both terminal silanol-modified siloxane (Shin-Etsu Chemical X21-5841, molecular weight 1000) was replaced with both terminal silanol-modified siloxane (Shin-Etsu Chemical KF-9701, molecular weight 3000). I got the product and did the same experiment.

[Example 4]
Both terminal silanol-modified siloxane (Shin-Etsu Chemical X21-5841, molecular weight 1000) is replaced with both terminal silanol-modified siloxane (Shin-Etsu Chemical KF-9701, molecular weight 3000), and D4OH concentrate: both terminal silanol-modified siloxane: tetrahydrofuran However, a silanol composition was obtained in the same manner as in Example 1 except that the mass ratio was 6:4:90 (that is, the content of silanol-modified siloxane at both ends was 40% by mass). A similar experiment was conducted.

[Example 5]
Silanol in the same manner as in Example 1 except that both ends silanol-modified siloxane (Shin-Etsu Chemical X21-5841, molecular weight 1000) was replaced with both ends silanol-modified siloxane (Gelest DMS-S15, molecular weight 2000 to 3500). A composition was obtained and similarly tested.

[Example 6]
Both terminal silanol-modified siloxane (Shin-Etsu Chemical X21-5841, molecular weight 1000) is replaced with both terminal silanol-modified siloxane (Gelest DMS-S15, molecular weight 2000 to 3500), and D4OH concentrate: both terminal silanol-modified siloxane: A silanol composition was obtained in the same manner as in Example 1, except that the mass ratio of tetrahydrofuran was 6:4:90 (that is, the content of silanol-modified siloxane at both ends was 40% by mass). , conducted a similar experiment.

[Example 7]
(Preparation of silanol composition)
In a reaction vessel, 28 g of distilled water, 960 mL of tetrahydrofuran (THF, manufactured by Wako Pure Chemical Industries), and 3.7 g of Pd/C (10% palladium-carbon, manufactured by N.E. Chemcat) were added and mixed. was maintained at 5°C.
81 g of 1,3,5,7-tetramethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd., also referred to as D4H) was gradually added to the reaction vessel, and after stirring for 2 hours, SiH groups disappeared by ¹ H-NMR. 1.8 g of the Pd/C (10% palladium-carbon) was added in 3 portions until the reaction reached 17 hours in total.
¹ H-NMR of the reaction solution was measured using a JEOL NMR (ECZ400S) with a heavy acetone solution having a concentration of 1% by mass, and the disappearance of 4 to 5 ppm of SiH groups was confirmed.
75 g of magnesium sulfate was added to the reaction solution and stirred at 5°C for 30 minutes. 545 (manufactured by Wako Pure Chemical Industries, Ltd.) (450 g) was filled into the funnel using tetrahydrofuran. Subsequently, the reaction solution is passed through the celite, the celite is washed with 1.5 L of tetrahydrofuran, and 1,3,5,7-tetrahydroxy-1,3,5,7-tetramethyltetracyclosiloxane (hereinafter referred to as 2057 g of a THF solution containing (also referred to as D4OH) was obtained.
This solution was concentrated with an evaporator in a water bath of 15° C. to a residual amount of 587 g (649 mL), and poured into a mixed solvent of 4.4 L of tetrahydrofuran and 217 mL of dichloromethane. After the mixture was allowed to stand at 5° C. for 4 hours, the precipitated insoluble matter was filtered under reduced pressure to recover 22 g of a crystalline solid. 6169 g of the solubles filtrate was concentrated under reduced pressure to yield 89 g of D4OH concentrate (ie, hydrosiloxane oxidation reactant).
Furthermore, silica particles (MEKST-40, manufactured by Nissan Chemical Industries, Ltd., particle size 40 nm) were added to the D4OH concentrate so that the mass ratio of D4OH concentrate: silica was 50:50, and the solid content concentration was 16 mass. % to obtain a silanol composition (isopropanol solution).
Using the obtained silanol composition, the haze was measured according to the method described above (Measurement of haze), and the peak area in the differential molecular weight distribution curve of GPC was measured. Also, the proportions of all-cis type and cis-trans-cis type cyclic silanols were calculated by ¹ H-NMR.
Also, the content of the transition metal Pd was calculated as described above.

(Confirmation of curing of silanol composition, confirmation of adhesive strength, and measurement of light transmittance of cured product)
8.3 g of the silanol composition obtained in the above (Preparation of silanol composition) was coated on quartz glass with a bar coater No. 1. 2 was applied to a thickness of 3 μm, quartz glass was placed thereon, and cured with a temperature program of 80° C. for 6 hours and 180° C. for 6 hours.
After curing, only one glass plate was lifted, and after confirming that the glass was adhered, the haze of the resulting cured product was measured.

(Abrasion resistance evaluation of hardened material)
Primer SHP470FT2050 (manufactured by Momentive) was applied to a 10 cm square, 1 mm thick polycarbonate plate (Takiron 1600) with a bar coater No. 16 (manufactured by AS ONE) and cured in an oven at 30° C. for 30 minutes and 120° C. for 30 minutes to obtain a polycarbonate plate coated with a 2 μm primer.
The silanol composition obtained in the above (Preparation of silanol composition) was applied to the polycarbonate plate using a bar coater No. 1. After coating the primer-coated polycarbonate plate in step 16, it was cured in an oven at 100° C. for 2 hours and then at 120° C. for 2 hours to obtain a cured plate.
The resulting hardened plate was subjected to a Taber abrasion test of 500 times at a rotation speed of 60 rpm using 101 TABER TYPE ABRASION TESTER (manufactured by Yasuda) with CALIBRASE CS-10F (manufactured by TABER INDUSTRIES) attached to the wear wheel.
For all measurement samples, before the Taber abrasion test, the wear wheels were polished 25 times at a rotational speed of 60 rpm using ST-11 REFACEING STONE (manufactured by TABER INDUSTRIES).
The haze of the measurement sample after the Taber abrasion test was measured using a HAZE METER NDH 5000SP (manufactured by NIPPON DENSHOKU), and the increase in haze (ΔHaze (%)) before and after the Taber abrasion test was calculated.

[Example 8]
An experiment similar to Example 7 was performed, except that silica particles were added such that the weight ratio of D4OH concentrate:silica was 75:25 (silica addition rate was 25% by weight).

[Example 9]
(Preparation of silanol composition)
In a reaction vessel, 28 g of distilled water, 960 mL of tetrahydrofuran (THF, manufactured by Wako Pure Chemical Industries), and 3.7 g of Pd/C (10% palladium/carbon, manufactured by N.E. Chemcat) were added and mixed. was maintained at 5°C.
81 g of 1,3,5,7-tetramethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd., also referred to as D4H) was gradually added to the reaction vessel, and after stirring for 2 hours, SiH groups disappeared by ¹ H-NMR. 1.8 g of the Pd/C (10% palladium/carbon) was added in 3 portions until the reaction reached 17 hours in total.
¹ H-NMR of the reaction solution was measured using a JEOL NMR (ECZ400S) with a heavy acetone solution having a concentration of 1% by mass, and the disappearance of 4 to 5 ppm of SiH groups was confirmed.
75 g of magnesium sulfate was added to the reaction solution, and after stirring at 5° C. for 30 minutes, 450 g of powdered cellulose KC Floc W50GK (manufactured by Nippon Paper Industries) as a filter aid was filled into a funnel using tetrahydrofuran. Subsequently, the reaction solution is passed through the powdered cellulose, the powdered cellulose is washed with 1.5 L of tetrahydrofuran, and 1,3,5,7-tetrahydroxy-1,3,5,7-tetramethyltetracyclosiloxane ( 2057 g of a THF solution containing (hereinafter also referred to as D4OH) was obtained.
This solution was concentrated with an evaporator at a water bath of 15° C. to a residual volume of 587 (649 mL), and poured into a mixed solvent of 4.4 L of tetrahydrofuran and 217 mL of dichloromethane. After the mixture was allowed to stand at 5° C. for 4 hours, the precipitated insoluble matter was filtered under reduced pressure to recover 22 g of a crystalline solid. 6169 g of the filtrate of the soluble part was concentrated under reduced pressure to obtain a silanol composition (89 g) which was a hydrosiloxane oxidation reaction product.
Using the obtained silanol composition, the haze was measured according to the method described above (Measurement of haze), and the peak area in the differential molecular weight distribution curve of GPC was measured.
Also, the proportions of all-trans type and cis-trans-cis type cyclic silanols were calculated by ¹ H-NMR. The Na, V content, and transition metal (Pd) content were measured as described above.

(Confirmation of curing of silanol composition, confirmation of adhesive strength, measurement of light transmittance of cured product)
8.3 g of the silanol composition obtained in the above (Preparation of silanol composition) was coated on quartz glass with bar coater No. 1. 2 was applied to a thickness of 3 μm, quartz glass was further placed thereon, and cured with a temperature program of 80° C. for 6 hours and 180° C. for 6 hours. After curing, only one glass plate was lifted to confirm that the quartz glass was adhered.
After that, the light transmittance at 400 to 800 nm of the obtained cured product was measured.

(Storage stability test of silanol composition)
The resulting silanol composition was allowed to stand at room temperature of 25° C. for one month.
The silanol composition was touched with a spatula to confirm whether it was solidified, and the storage stability was evaluated based on the presence or absence of solidification.
In the table, 〇 means that the material was not solidified, and × means that it was solidified.

[Example 10]
(Preparation of silanol composition)
In a reaction vessel, 28 g of distilled water, 960 mL of tetrahydrofuran (manufactured by Wako Pure Chemical Industries), and 3.7 g of Pd/C (10% palladium/carbon, manufactured by N.E. Chemcat) were added and mixed. °C.
81 g of 1,3,5,7-tetramethylcyclotetrasiloxane (manufactured by Tokyo Chemical Industry Co., Ltd., also referred to as D4H) was gradually added to the reaction vessel, and after stirring for 2 hours, the mixture was stirred until SiH groups disappeared by ¹ H-NMR. 1.8 g of Pd/C (10% palladium/carbon) was divided into three portions, and the reaction was carried out for a total of 17 hours. The disappearance of the SiH group is determined by measuring ¹ H-NMR of the reaction liquid with a heavy acetone solution having a concentration of 1% by mass using JEOL NMR (ECZ400S), and detecting the disappearance of the SiH group present at 4 to 5 ppm. confirmed.
75 g of magnesium sulfate was added to the reaction solution, and the mixture was stirred at 5°C for 30 minutes. Celite No. 545 (manufactured by Wako Pure Chemical Industries, Ltd.) (450 g) was filled into the funnel using tetrahydrofuran. Subsequently, the reaction solution is passed through the celite, the celite is washed with 1.5 L of tetrahydrofuran, and 1,3,5,7-tetrahydroxy-1,3,5,7-tetramethyltetracyclosiloxane (hereinafter referred to as 2057 g of a THF solution containing (also referred to as D4OH) was obtained. This solution was concentrated with an evaporator in a water bath of 15° C. to a residual amount of 587 g (649 mL), and poured into a mixed solvent of 4.4 L of tetrahydrofuran and 217 mL of dichloromethane. After the mixture was allowed to stand at 5° C. for 4 hours, the precipitated insoluble matter was filtered under reduced pressure to recover 22 g of a crystalline solid. 6169 g of the filtrate of the soluble portion was concentrated under reduced pressure until a mixed solution of tetrahydrofuran and dichloromethane containing 10% by mass of the silanol composition was obtained. After concentrating 10 g of a mixed solution of 10% by mass of silanol composition in tetrahydrofuran and dichloromethane to 1 g under reduced pressure, 100 g of isopropanol was added again. Furthermore, concentration was performed again under reduced pressure to prepare a silanol composition (isopropanol solution) having a predetermined concentration.
Physical properties such as haze were evaluated using the obtained silanol composition. Also, the ratio of stereoisomers of cyclic silanol was calculated by ¹ H-NMR. ¹ H-NMR spectrum is shown in FIG.

[Example 11]
The all-trans isomer (cyclic silanol (B4)) prepared in (Preparation of each stereoisomer) was added to the silanol composition (isopropanol solution) prepared in Example 10, and the all-tras isomer ratio was 43. The same experiment as in Example 10 was performed, except that % was used.

[Example 12]
The all-trans isomer (cyclic silanol (B4)) prepared in (Preparation of each stereoisomer) was added to the silanol composition (isopropanol solution) prepared in Example 10, and the all-tras isomer ratio was 56. The same experiment as in Example 10 was performed, except that % was used.

[Example 13]
The all-cis isomer (cyclic silanol (B1)) prepared in (Preparation of each stereoisomer) was added to the silanol composition (isopropanol solution) prepared in Example 10, and the all-cis isomer ratio was 31. The same experiment as in Example 10 was performed, except that % was used.

[Example 14]
The all-cis isomer (cyclic silanol (B1)) prepared in (Preparation of each stereoisomer) was added to the silanol composition (isopropanol solution) prepared in Example 10, and the all-cis isomer ratio was 41. The same experiment as in Example 10 was performed, except that % was used.

[Example 15]
The trans-trans-cis isomer (cyclic silanol (B3)) prepared in (Preparation of each stereoisomer) was added to the silanol composition (isopropanol solution) prepared in Example 10 to obtain trans-trans-cis The same experiment as in Example 10 was conducted, except that the body ratio was 66%.

[Example 16]
The same experiment as in Example 10 was conducted except that the recrystallization temperature in Example 10 was -40°C. FIG. 2 shows the ¹ H-NMR spectrum.

[Comparative Example 1]
The same test as in Example 1 was performed using the resin described in Example 1 of JP-A-2011-42755.

Tables 1 and 2 show physical properties and evaluation results of the silanol compositions and cured products obtained in Examples and Comparative Examples.

In Tables 1 and 2, "-" indicates "not present" for components and "not measured" for properties.

The radiation-resistant or outer space silanol composition of the present invention is used in outer space, materials used for objects exposed to atomic oxygen, ultraviolet rays, electron beams, etc., fast breeder reactors, nuclear power As a material used for objects exposed to radiation such as electron beams at power plants, radiation irradiation facilities, nuclear fuel disposal work, decommissioning work, uranium enrichment facilities, radioactive waste treatment facilities, spent fuel reprocessing facilities, etc. It has industrial applicability.

Specifically, the silanol composition for radiation resistance or space use of the present invention is used for heat control materials, heat insulating films, sheets, fabrics, paints, solar reflectors, heat conductive adhesives, thermal fillers, Structure panels (mainly composite materials), trusses, tethers (strings), debris bumpers (plates or cushion materials that protect spacecraft from space debris), solar array paddles (including solar array cell protective covers), electric wires, insulation coatings, heaters, antenna components, cameras, monitors, lighting and their protective covers (including radio-transmitting radomes), robot arms, outer skins of spacesuits, heat-insulating tiles and window materials for spacecraft, moons and planets Films, sheets, fabrics, foams for structures on upper space stations or probes, rovers and probes, large deployment structures, space inflatable structures or solar sails (large structures using photon pressure propulsion) And shape memory materials, space elevator cables and elevator housings, development films, sheets and foam materials for de-orbiting spacecraft in the final stage of operation (de-orbit using increased air resistance). have sex.

Further, the radiation-resistant or outer space silanol composition of the present invention is specifically used for fast breeder reactors, nuclear power plants, radiation irradiation facilities, nuclear fuel disposal work, decommissioning work, uranium enrichment facilities, radioactive waste treatment Films and sheets to protect devices, electronic substrates, semiconductors, resins, metals, inorganic substances, organic substances, and polymers from radiation when they are placed in high-dose radiation environments such as facilities, spent fuel reprocessing facilities, etc. , textiles, foaming agents and shape memory materials, adhesives, etc.

Claims (14)

including a cyclic silanol (A1) represented by the following formula (I) and a dehydration condensate (A2) thereof,
A silanol composition used for radiation resistance or space applications.

(In formula (I), R is a methyl group and n is 3. ) The silanol composition according to claim 1, wherein the cyclic silanol (A1) is represented by the following formula (1).

(In Formula (1), R ¹ to R ⁴ are methyl groups .) The cyclic silanols (A1) are cyclic silanols (B1) to (B4) represented by the following formulas (2) to (5):

(In formulas (2) to (5), R ¹ to R ⁴ are methyl groups .)
contains
where b is the ratio (mol%) of the cyclic silanol (B2) to the total amount of the cyclic silanols (B1) to (B4), satisfying 0 < b ≤ 20,
A silanol composition according to claim 1 or 2. In measurement by gel permeation chromatography, the area of the dehydrated condensation product (A2) is more than 0% and 50% or less with respect to the total area of the cyclic silanol (A1) and the dehydrated condensation product (A2).
The silanol composition according to any one of claims 1-3. the proportion of transition metals is less than 1 ppm by weight;
The silanol composition according to any one of claims 1-4. containing solvents,
The silanol composition according to any one of claims 1-5. including silica particles having an average particle size of 1 nm or more and 100 nm or less,
The silanol composition according to any one of claims 1-6. Including both terminal silanol-modified siloxane represented by the following formula (6),
The silanol composition according to any one of claims 1-7.

(in formula (6), each R' is independently a fluorine atom, an aryl group, a vinyl group, an allyl group, a fluorine-substituted linear or branched alkyl group having 1 to 4 carbon atoms, Alternatively, it is an unsubstituted linear or branched alkyl group having 1 to 4 carbon atoms, and m is an integer of 0 to 1000.) The total content of Na and V is less than 60 mass ppm,
The silanol composition according to any one of claims 1-8. A cured product of the silanol composition according to any one of claims 1 to 9, which is used for radiation resistance or outer space. An adhesive comprising the silanol composition according to any one of claims 1 to 9 and used for radiation resistance or outer space. a film;
A cured product placed on the film;
A composite membrane used for radiation resistance or outer space, comprising
A composite film, wherein the cured product is the cured product according to claim 10 . A curing method for thermally curing the silanol composition according to any one of claims 1 to 9,
A curing method in which the curing temperature is 60 to 250°C. The curing method according to claim 13, wherein the curing time is 10 minutes to 72 hours.

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