JP7706491B2 - Curable composition and cured film thereof - Google Patents

Description

The present invention relates to a novel curable composition and a cured film thereof.

Optical products such as various lighting fixtures, lenses, displays, and indicators, as well as their accessories such as covers, are given surface treatments that impart stain resistance, water repellency, abrasion resistance, etc., so that their optical properties can be maintained for a long period of time.

Various chemical and physical methods are used for surface treatment, but the method of applying a coating agent to a substrate (subject to be coated) is widely used due to its simplicity. Recently, various coating agents using perfluoropolyether group-containing materials have been proposed. For example, a surface treatment agent containing a perfluoropolyether group-containing silane compound represented by a specific chemical formula is known (Patent Documents 1 to 3).

JP 2020-90652 A JP 2018-172655 A International Publication WO2018/79743

However, although these conventional surface treatment agents exhibit good properties such as water repellency, antifouling properties, and abrasion resistance, further improvements are necessary. In other words, perfluoropolyether group-containing materials are designed primarily for the purpose of protecting touch panels of smartphones, tablet terminals, and the like, and while sufficient properties are obtained under such conditions of use, there is no guarantee that water repellency, antifouling properties, abrasion resistance, and the like will be obtained under other conditions of use (especially outdoors where the material is exposed to sand, dust, and the like).

For example, outdoor security cameras, weather observation cameras, river monitoring cameras, cameras mounted on vehicles and ships, outdoor lighting (street lights, parking lots, stadiums, etc.), and covers for these, are exposed to sand, dust, and other particles for long periods of time, and therefore must be able to withstand these. Even if a protective layer is formed for such applications by applying a surface treatment agent containing a conventional perfluoropolyether group-containing silane compound, repeated collisions with sand, dust, and other particles (sand grains, etc.) can wear away the protective layer, resulting in a risk of deterioration of the original optical properties of the lighting, lenses, etc. For this reason, there is a demand for the development of a protective layer that can provide effective protection even in such environments.

Therefore, the main object of the present invention is to provide a thermosetting composition capable of forming a protective layer that exhibits excellent abrasion resistance, particularly when used outdoors.

As a result of extensive research into the problems of the prior art, the inventors discovered that the above-mentioned objectives could be achieved by adopting a composition having a specific composition, and thus completed the present invention.

That is, the present invention relates to the following thermosetting composition and cured film thereof.
1. The following ingredients:
(1) Perfluoropolyether group-containing alkoxysilanes, and (2) alkoxysilanes containing two or more trialkoxysilyl groups (excluding the alkoxysilanes in (1) above).
A thermosetting composition comprising:
2. The thermosetting composition according to item 1, wherein the alkoxysilane (1) has a number average molecular weight of 3,000 or more.
3. A thermosetting composition according to item 1 or 2, wherein the trialkoxysilyl groups in the alkoxysilane (2) are the same or different and are represented by the general formula -Si(OC _n H _2n+1 ) ₃ (wherein n is an integer of 1 to 3).
4. The thermosetting composition according to any one of items 1 to 3, wherein in the alkoxysilane (2), two or more trialkoxysilyl groups are bonded to each other via an organic group containing an alkylene group in which some or all of the hydrogen atoms may be substituted with fluorine atoms.
5. The thermosetting composition according to claim 4, wherein the organic group has an isocyanuric ring skeleton.
6. The thermosetting composition according to any one of items 1 to 5, comprising 50 to 300 parts by mass of the alkoxysilane of (2) per 100 parts by mass of the perfluoropolyether group-containing alkoxysilane.
7. The thermosetting composition according to any one of items 1 to 6, further comprising (3) an alkoxysilane containing one trialkoxysilyl group (excluding the alkoxysilane of (1) above).
8. The thermosetting composition according to any one of items 1 to 7, further comprising (4) a tetraalkoxysilane hydrolysis condensate.
9. The thermosetting composition according to any one of items 1 to 8, further comprising an organic solvent and being in a liquid state.
10. A cured film obtained by curing the thermosetting composition according to any one of items 1 to 9.
11. A laminate comprising the cured film according to item 10 laminated on a substrate.
12. An article comprising the cured film according to item 10 laminated on a substrate.
13. An optical product comprising the cured film according to item 10 laminated on a substrate.
14. The optical product according to claim 13, which is for outdoor use.

The present invention provides a thermosetting composition capable of forming a protective layer that can withstand outdoor use. The thermosetting composition of the present invention exhibits high resistance to abrasion caused by collisions with particles (sand grains, etc.) that constitute sand, dust, etc., due to the combination of two or three types of alkoxysilanes, making it possible to maintain abrasion resistance over a long period of time, and in turn, the water repellency, transparency, etc., of the cured film.

Conventional cured films are designed primarily with an eye towards increasing hardness, but high hardness also increases brittleness, and so even if they have a certain level of abrasion resistance, they cannot withstand collisions with particles such as sand, dust, etc. In particular, cured films formed from alkoxysilane compounds are composed of silicon atoms, and sand, dust, etc. are generally also composed mainly of silicon atoms, so even if the cured film is made hard and thick, it is prone to being destroyed by impact.

In contrast, the cured film of the present invention is believed to have a certain degree of softness and flexibility, and is therefore presumed to have a certain degree of durability against collisions with particles such as sand and dust. In particular, when an alkyl group or alkylene group is introduced, higher abrasion resistance can be exhibited. Although the mechanism of action is unclear, it is believed that the flexibility and other properties are enhanced by the C-C bond, which reduces brittleness and allows the film to absorb impacts from dust, sand, and the like, thereby exhibiting higher abrasion resistance (impact resistance).

The thermosetting composition of the present invention or its cured film having such characteristics can be used not only as a protective film for optical products used indoors (indoors), but also can be suitably used as a protective film for optical products used outdoors where collisions with particles such as sand, dust, etc. may occur.

1. Thermosetting Composition The thermosetting composition of the present invention (the composition of the present invention) comprises the following components:
(1) an alkoxysilane containing a perfluoropolyether group (first component), and (2) an alkoxysilane containing two or more trialkoxysilyl groups (excluding the alkoxysilane in (1) above) (second component).
The present invention is characterized by comprising:

A. Constituents of the Composition of the Present Invention Component 1 The first component, a perfluoropolyether group-containing alkoxysilane, mainly functions to impart good water and oil repellency, water sliding properties, abrasion resistance, etc. to the cured film.

In the present invention, the type of alkoxysilane containing a perfluoropolyether group is not particularly limited, but for example, a compound represented by the general formula A-PFPE-B (wherein PFPE represents a perfluoropolyether group, and one or both of A and B are organic groups having an alkoxysilyl group at the end, and if the end is not the organic group, it is an alkyl group in which some or all of the hydrogen atoms may be substituted with fluorine atoms) can be preferably used. In particular, in the present invention, from the viewpoint of film-forming properties, etc., it is desirable that the above A and B are the same or different and are organic groups having an alkoxysilyl group at the end.

The organic group having an alkoxysilyl group may be an alkoxysilyl group alone, or may contain an alkoxysilyl group and another organic group. The alkoxysilyl group is not particularly limited, but is preferably a trialkoxysilyl group represented by the general formula -Si(OC _n H _2n+1 ) ₃ (wherein n is an integer of 1 to 3). Examples of the alkoxysilyl group include a trimethoxysilane group and a triethoxysilane group.

When A or B is an alkoxysilyl group alone, the structure is one in which the alkoxysilyl group is directly bonded to PFPE.

When A or B contains an alkoxysilyl group and another organic group, the alkoxysilyl group is bonded to PFPE via the other organic group. In the case of containing an alkoxysilyl group and another organic group, an organic group (specific organic group) represented by the general formula -R ¹ -(OCONH) _m -R ² -R ³ (wherein R ¹ and R ² are the same or different and represent a divalent hydrocarbon group having 1 to 10 carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine, examples of which include -(CH ₂ ) _n - (wherein n is an integer of 1 to 10), -(CF ₂ ) _n - (wherein n is an integer of 1 to 10), -CH ₂ CF ₂ -, -CF ₂ CH ₂ -, -CH ₂ CF(CF ₃ )-, and -CF(CF ₃ )CH ₂ -; R ³ represents an alkoxysilyl group; and m is 0 or 1) can be preferably used as the organic group having the alkoxysilyl group.

Here, R ¹ and R ² may be the same or different and preferably have a carbon number in the range of about 1 to 10, and more preferably 1 to 6.

The above m is 0 or 1. In other words, the specific organic group may or may not contain a urethane bond -OCONH-.

The alkoxysilyl group ^R3 is not particularly limited, but is preferably a trialkoxysilyl group represented by the general formula -Si( _{OCnH2n +1} ) ₃ (wherein n is an integer of 1 to 3). Examples of the alkoxysilyl group include a trimethoxysilane group and a triethoxysilane group.

In the above A-PFPE-B, when A or B is not an organic group having an alkoxysilyl group at the terminal, it is preferably an alkyl group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms, such as CF ₃ -, CF ₃ CF ₂ -, CF ₃ CH ₂ -, CH ₃ -, and CF ₃ CF ₂ CF ₂ -.

The perfluoropolyether group (PFPE) has a structure in which a plurality of -( _CxF2xO ) _m- (x and _m are integers other than 0) are linked together as a basic unit. When m is 2 or more, each ( _CxF2xO ) may be _the same as or different from each other. That is, PFPE may have a structure consisting of a single type of unit repeated alone, or may have a structure consisting of a combination of two or more different types of units. In addition, _{( CxF2xO} ) may have a straight or branched carbon chain.

Examples of the unit -( _CxF2xO )- include _, but are _not limited to _{, CF2O} , _CF2CF2O , _CF2CF2CF2O , _{CF2CF2CF2CF2CF2O} , _CF ( _CF3 ) _CF2O , etc. In particular, in the present invention, _{- ( CF2CF2O} ) _m- ( _CF2O ) _n- (wherein _m and _n are integers other than 0 ₎ and the like can be suitably adopted as PFPE. In this case, the m and n can be within the range of, for example, about 10≦m≦40, about 10≦n≦40, but are not limited to the above range of m and n as long as they are within the above molecular weight range.

The number average molecular weight of the perfluoropolyether group-containing alkoxysilane, which is the first component, is not particularly limited, but is usually preferably 3000 or more, more preferably 3000 to 8000, and most preferably 3500 to 7000. By having such a molecular weight, it is possible to obtain superior effects in terms of water and oil repellency, water sliding properties, abrasion resistance, etc.

The method for measuring the number average molecular weight in the present invention is not particularly limited, and can be performed by measurement in terms of polymethyl methacrylate using gel permeation chromatography, or by structural analysis using nuclear magnetic resonance spectroscopy.

As such a first component, publicly known or commercially available products can be used, and compounds synthesized by publicly known manufacturing methods can also be used. For example, a commercially available product such as "Optool DSX" (manufactured by Daikin Industries, Ltd.) can be used.

When synthesizing the first component, for example, a method of bonding a trialkoxysilyl group to both ends or one end of a perfluoropolyether group can be adopted. More specifically, the first component can be suitably prepared by reacting an isocyanate group-containing alkoxysilane compound with a compound (starting compound) having a perfluoropolyether group as the main chain and OH groups as both or one of the end groups. More specifically, as the starting compound, a compound represented by the general formula X-PFPE-Y (wherein PFPE represents a perfluoropolyether group, one or both of X and Y are hydroxyl groups, and when X or Y is not a hydroxyl group, it represents an alkyl group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms) can be suitably used.

As the starting compound, known or commercially available compounds can be used. That is, compounds in which both terminal groups of the perfluoropolyether group are hydroxyl groups, compounds in which only one terminal group of the perfluoropolyether group is a hydroxyl group, etc., can be used.

Examples of commercially available compounds having perfluoropolyether groups at both ends thereof that have hydroxyl groups include those with the product names "FLUOROLINK D-4000" and "FLUOROLINK D-6000" (both manufactured by Solvay K.K.). The above "FLUOROLINK D-4000" and "FLUOROLINK D-6000" have the basic structure represented by the following general formula (1).

Examples of commercially available compounds in which only one of the terminal groups of the perfluoropolyether group is a hydroxyl group include products with the names "DOL-3000" and "DOL-4000" (both manufactured by Sinochem Corporation) and "PFPE KFE240AL" (manufactured by Chemours Inc.).

In the above starting compound, when one end group is a hydroxyl group, the other end group may be an alkyl group having 10 or less carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms, such as CF ₃ -, CH ₃ -, CF ₃ CH ₂ -, CF ₃ CF ₂ -, and CF ₃ CF ₂ CF ₂ -.

The isocyanate group-containing alkoxysilane compound may be any compound having an isocyanate group and an alkoxysilyl group, and publicly known or commercially available compounds may be used. For example, a commercially available compound such as "KBE-9007N" (3-isocyanatepropyltriethoxysilane) (manufactured by Shin-Etsu Silicones) may be suitably used.

The production conditions are not particularly limited, but can be carried out, for example, by a method including a step of reacting a starting compound and an isocyanate group-containing alkoxysilane compound in a solvent at a temperature of 20 to 70°C (reaction step) and a step of recovering the first component (target product) from the reaction product liquid (recovery step).

In the reaction process, the ratio of the starting compound to the isocyanate group-containing alkoxysilane compound is not particularly limited, but can be set appropriately within the range of, for example, a molar ratio of about 1:1 to 1:4.

In the reaction step, a liquid phase reaction may be carried out using a solvent, and it is preferable to use a fluorine-based solvent as the solvent. As the fluorine-based solvent, for example, a hydrofluoroether-based solvent can be suitably used. As such a solvent, a known or commercially available solvent can also be used. For example, 1,3-bis(trifluoromethyl)benzene can be used. As a commercially available product, for example, product names "Novec HFE-7200" and "Novec HFE-7300" (both 3M products) can be suitably used.

The reaction step can be carried out in the presence of a catalyst, if necessary. As the catalyst, an alkaline catalyst can be suitably used, and among them, at least one organic alkaline catalyst such as triethylamine, tributylamine, pyridine, and 1,4-diazabicyclo[2.2.2]octane is particularly preferred.

In the recovery step, the method is not particularly limited as long as it can recover (isolate) the first component, which is the target product. For example, a method can be adopted in which an alcohol (methanol, ethanol, etc.) is added to the reaction product liquid, the liquid is separated, and then the supernatant liquid (the upper layer of the reaction product liquid) is removed. That is, since the first component generally settles in the reaction product liquid, it is possible to purify and separate it by removing the supernatant liquid. By repeating the series of steps of adding the alcohol and removing the supernatant liquid multiple times, the first component can be obtained with a higher yield. In this case, the first component can also be recovered as a solid content by carrying out decompression, drying, etc., as necessary.

The solid content of the first component in the composition of the present invention is not limited, but is usually 10 to 60% by mass, preferably 10 to 50% by mass, and more preferably 15 to 30% by mass. This makes it possible to more reliably achieve excellent scratch resistance, etc.

Second Component The second component, an alkoxysilane containing two or more trialkoxysilyl groups, is used primarily to reduce the brittleness of the cured film and impart high abrasion resistance by absorbing the impact upon collision with particles such as sand, dust, and other particles (such as sand grains).

The number of trialkoxysilyl groups may be 2 or more, for example, 2, 3, 4, etc. In addition, when using a plurality of second components, the numbers may be the same or different. For example, a second component having two trialkoxysilyl groups and a second component having three trialkoxysilyl groups can be used in combination.

The trialkoxysilyl group in the second component is not limited, but typically, a trialkoxysilyl group represented by the general formula -Si( _{OCnH2n +1} ) ₃ (wherein n is an integer of 1 to 3) can be suitably used. Examples include a trimethoxysilane group and a triethoxysilane group.

In the second component, two or more trialkoxysilyl groups are preferably bonded to each other via an organic group containing an alkylene group in which some or all of the hydrogen atoms may be substituted with fluorine atoms.

The alkylene group may have about 1 to 10 carbon atoms. For example, —CH ₂ —, —CH ₂ CH 2 —, CF 2 CH ₂ —, —CH ₂ CH 2 CH ₂ —, —CH ₂ CH ₂ CH _{2 CH 2 CH 2 —} , —CH 2 CH ₂ CH ₂ CH ₂ CH 2 —, —CH ₂ CH ₂ CH ₂ CH _{2 —} , —CH ₂ CH ₂ CH ₂ CH ₂ —, —CF ₂ CF ₂ CF ₂ —, etc. It is preferable that a carbon atom of the alkylene group is directly bonded to a silicon atom of the trialkoxysilyl group .

Examples of the organic group include organic groups composed only of the above alkylene groups, as well as organic groups in which the above alkylene groups are bonded to a cyclic skeleton. Examples of the cyclic group include an isocyanuric ring skeleton, a cyclohexyl ring skeleton, and a benzene ring skeleton.

Specific examples of the second component include 1,6 bis-(trimethoxysilyl)hexane, bis(trimethoxysilyl)ethylene, and tris(trimethoxysilylpropyl)isocyanurate.

The bistrimethoxysilylethylene is represented by the following general formula (2). The 1,6-bis(trimethoxysilyl)hexane is represented by the following general formula (3). The tris(trimethoxysilylpropyl)isocyanurate is represented by the following general formula (4). In the formulas below, each Me represents a methyl group.

These compounds may be publicly known or commercially available. Commercially available products include, for example, products with the names "KBM-3066" and "KBM-9659" (both manufactured by Shin-Etsu Silicones).

The solid content of the second component in the composition of the present invention is not particularly limited, but in order to ensure that the second component exhibits the functions described above, it is usually about 10 to 50 mass%, and preferably 20 to 40 mass%.

The second component does not include the first component, which is an alkoxysilane containing a perfluoropolyether group. In other words, the second component is composed of a compound that does not contain a perfluoropolyether group.

Third Component In the present invention, an alkoxysilane containing one trialkoxysilyl group may be included as a third component as necessary. The third component, an alkoxysilane containing one trialkoxysilyl group, mainly has the function of imparting good film-forming properties, curing properties, etc.

The alkoxysilane is not particularly limited as long as it has one trialkoxysilyl group, but in particular, a compound represented by R ⁴ -Si(OR ⁵ ) ₃ (wherein R ⁴ represents an alkyl group having 1 to 10 carbon atoms in which some or all of the hydrogen atoms may be substituted with fluorine atoms, and R ⁵ represents an alkyl group having 1 to 3 carbon atoms) can be preferably used. More specific examples include methyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, hexyltrimethoxysilane, hexyltrimethoxysilane, octyltriethoxysilane, 3,3,3-trifluoropropyltrimethoxysilane, and the like.

These may be publicly known or commercially available. Examples of commercially available products include those with the product names "KBE-3083", "KBE-13", "KBM-3033", "KBE-3033", "KBE-3083", and "KBM-7103" (all manufactured by Shin-Etsu Silicones).

The solid content of the third component in the composition of the present invention is not particularly limited, but is usually about 0 to 60% by mass, preferably 25 to 60% by mass, more preferably 30 to 60% by mass, and most preferably 40 to 50% by mass. This makes it possible to more reliably obtain excellent scratch resistance, etc.

The third component does not include the first component, which is an alkoxysilane containing a perfluoropolyether group. In other words, the third component is composed of a compound that does not contain a perfluoropolyether group.

The ratios of the first, second, and third components are not limited, but are preferably 50 to 300 parts by mass of the second component and 0 to 300 parts by mass of the third component per 100 parts by mass of the first component, more preferably 50 to 300 parts by mass of the second component and 100 to 300 parts by mass of the third component, and most preferably 100 to 200 parts by mass of the second component and 200 to 250 parts by mass of the third component per 100 parts by mass of the first component.

In the present invention, a tetraalkoxysilane hydrolysis condensate (silicate oligomer) can be contained as a fourth component, if necessary. By blending the tetraalkoxysilane hydrolysis condensate, it is possible to improve film-forming properties, curing properties, hardness, etc.

The tetraalkoxysilane hydrolysis condensate is not particularly limited, and may be, for example, a compound produced by hydrolysis and polycondensation of two or more molecules of tetraalkoxysilane, such as tetramethoxysilane or tetraethoxysilane. Depending on the number of molecules polycondensed, there are, for example, dimers, trimers, tetramers, etc., but in the present invention, dimers to decamers (average value) can be preferably used.

Such compounds can be publicly known or commercially available, or can be synthesized by known manufacturing methods. Examples of commercially available products include products with the names "Methyl Silicate 51" and "Methyl Silicate 53A" (both manufactured by Colcoat Co., Ltd.).

The solid content of the fourth component in the composition of the present invention is not particularly limited, but in order to ensure that the fourth component exhibits the functions described above, it is usually about 0 to 20 mass%, and preferably 1 to 15 mass%.

Other Components In addition to the first to fourth components, other components may be appropriately blended into the composition of the present invention as necessary within the range that does not impair the effects of the present invention. For example, in addition to the solvent described below, inorganic fine particles (fine particles of oxides such as silica, alumina, titania, and zirconia), colorants, etc. may be mentioned.

B. Properties of the composition of the present invention The form of the composition of the present invention is not limited, but it is usually sufficient to make it liquid. To make it liquid, a solvent may be added, but it may be either a solution or a dispersion.

The solvent can be appropriately selected depending on the type of the first component, etc. For example, at least one of a fluorine-based solvent, a ketone-based solvent, an ester-based solvent, an alcohol-based solvent, and an amide-based solvent can be used.

Examples of fluorine-based solvents include trifluorotoluene, perfluorobutyl methyl ether, perfluorobutyl ethyl ether, and metaxylene hexafluoride.

Examples of ketone solvents include acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone.

Examples of ester-based solvents include ethyl acetate, butyl acetate, methoxybutyl acetate, and methoxypropyl acetate.

Examples of alcohol-based solvents include methanol, ethanol, 1-propanol, isopropyl alcohol, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether (1-methoxy-2-propanol).

The amount of organic solvent used can be adjusted appropriately depending on the types of components used, the desired viscosity, etc., so that the solid content of the composition of the present invention is within the range of about 0.1 to 10% by weight (preferably about 0.1 to 5% by weight), but is not limited to this.

C. Preparation of the composition of the present invention The composition of the present invention can be prepared by uniformly mixing the above-mentioned components. The order of mixing is not particularly limited, and any order can be adopted. In particular, when preparing a liquid composition, the solvent may be mixed together with the first component and the like. The mixing may be carried out using a known or commercially available device such as a mixer or kneader. In addition, the atmosphere in which the components are mixed may usually be at room temperature and pressure, but is not limited thereto.

D. Use of the Composition of the Present Invention By curing a coating film of the composition of the present invention, a desired cured film can be formed. That is, from the composition of the present invention, a protective layer that is resistant to scratches, etc., even outdoors can be obtained more reliably.

The cured film may be transparent, translucent or opaque. In particular, when used as a protective layer for lighting, lenses or covers thereof, it is desirable for the cured film to be transparent or translucent. In this case, the transparency is not limited, but it is usually desirable for the haze value to be about 0.1 to 5%.

The thickness of the cured film can be set appropriately depending on the application, area of use, etc., but is usually about 0.05 to 2 μm, and preferably 0.1 to 0.5 μm.

The method for forming the cured layer is not particularly limited, and can be suitably carried out, for example, by a method including the steps of a) forming a coating film of the composition of the present invention on a substrate and b) curing the coating film.

The substrate that serves as the base (lower layer) of the cured layer is not particularly limited and may be, for example, any of synthetic resins, rubber, ceramics, glass, metal, etc. In particular, transparent substrates such as glass and synthetic resins (polyester-based resins, acrylic-based resins, etc.) can be preferably used. In addition, the substrate may be, for example, any of raw materials, semi-finished products, finished products, etc.

The coating film of the composition of the present invention can be formed by any known coating method, such as, for example, the doctor blade method, bar coating method, dipping method, air spray method, roller brush method, roller coater method, vapor deposition method, etc.

The amount of coating formed may be, for example, an amount that will result in the desired thickness of the cured film, and can usually be appropriately set so that the thickness of the resulting cured film is within a range of approximately 2 μm or less (preferably within a range of 0.1 to 0.5 μm).

The resulting coating film may be subjected to a drying process prior to curing, if necessary. The drying method may be natural drying or heating at a temperature of about 60 to 120°C.

The coating is then cured. In the present invention, the coating is cured by heating (thermal curing). The conditions for thermal curing may be set appropriately depending on the type of the first component, etc., but it is usually preferable to set the temperature at about 50 to 200°C (particularly 120 to 180°C) in air. The heating time may be long enough to cure the coating, and may be set within the range of, for example, 0.1 to 2 hours, but is not limited to this.

Furthermore, in the present invention, a laminate in which a cured film is laminated on a substrate can be obtained by a method including a step of forming a coating film of the composition of the present invention on a substrate and a step of curing the coating film. Such a laminate can be used, for example, as a material for various products.

2. Articles (optical products)
The present invention includes an article (particularly an optical product) in which the cured film of the present invention is laminated on a substrate. In particular, the cured film of the present invention has durability not only against simple friction between materials, but also against abrasion caused by collision with particles such as sand, dust, etc. (scattered sand grains, etc.), and therefore can be used as a protective layer for the substrate (product). In particular, it can be suitably used as a protective layer for the substrate (product) exposed to sand, dust, etc.

Therefore, the cured film of the present invention can be applied as a protective layer (outermost layer) for lighting, lenses, or covers used indoors, as well as for lighting, lenses, or covers used outdoors. For example, it is suitable for surface protection of a) outdoor security cameras, weather observation cameras, river monitoring cameras, cameras mounted on vehicles and ships, outdoor lighting (street lights, parking lots, stadiums, etc.), b) lenses used therein (lighting lenses or camera lenses), c) lighting or lens covers, etc. It can also be used as a protective layer for smartphone screens, tablet screens, etc.

Methods for applying the cured film of the present invention to these articles (particularly optical products) include, for example, forming a coating film of the composition of the present invention on the surface of the substrate to be protected as described above, and then forming a predetermined cured film (protective layer) by a method including a curing step, but are not limited to this.

The following examples and comparative examples are presented to more specifically explain the features of the present invention. However, the scope of the present invention is not limited to the examples.

Example 1
As shown in Table 1, 0.20 g of perfluoropolyether group-containing alkoxysilane (Production Example 1), 0.5 g of an alkoxysilane containing one trialkoxysilyl group (product name "KBM-7103" manufactured by Shin-Etsu Chemical Co., Ltd.), 0.2 g of bistrimethoxysilylethylene, 0.1 g of tetramethoxysilane hydrolysis condensate (product name "Methyl Silicate 51" manufactured by Colcoat Co., Ltd., average tetramer), and 99.0 g of a fluorine-based solvent (product name "Novec HFE-7200" manufactured by 3M Corporation) were weighed into a 200 mL beaker and stirred at room temperature for 1 hour to obtain a liquid composition. The liquid composition was applied to a cleaned glass plate and heated and cured in an oven at 170° C. for 30 minutes to produce a cured film. The film thickness at this time was about 0.2 μm.

Examples 2 to 12 and Comparative Examples 1 to 4
A liquid composition was prepared in the same manner as in Example 1, except that the composition was changed to that shown in Table 1. A cured film was produced using the liquid composition in the same manner as in Example 1.

The meanings of the abbreviations in Table 1 are as follows:
(1) First component: Perfluoropolyether group-containing alkoxysilane "Production Example 1": Perfluoropolyether group-containing alkoxysilane 1 synthesized in the following Production Example 1
<Production Example 1>
In a 30 mL eggplant flask equipped with a stirrer, 18.0 g (3.0 mmol) of a hydroxyl group-containing perfluoropolyether compound (product name "FLUOROLINK D-6000" (manufactured by Solvay, average molecular weight 6000), 1.48 g (7.2 mmol) of 3-isocyanatepropyltrimethoxysilane (manufactured by Kanto Chemical Co., Ltd.), 0.015 g (0.15 mmol) of triethylamine (manufactured by Kanto Chemical Co., Ltd.), and 18.0 g of meta-xylene hexafluoride were weighed. The reaction solution was stirred at 50°C for 6 hours. Methanol was added to the reaction solution after the reaction to separate the reaction solution. Since the lower layer was the target product, the solvent in the upper layer was removed. The washing process was repeated three times using methanol. The product was placed in an eggplant flask and dried under reduced pressure to remove the solvent, and the target perfluoropolyether group-containing alkoxysilane 1 (yield 90%, 17.3 g) was synthesized.
"Production Example 2": Perfluoropolyether group-containing alkoxysilane 2 synthesized in the following <Production Example 2>
<Production Example 2>
In a 30 mL eggplant flask equipped with a stirrer, 12.0 g (3.0 mmol) of a hydroxyl group-containing perfluoropolyether compound (product name "FLUOROLINK D-4000" (manufactured by Solvay, average molecular weight 4000), 1.48 g (7.2 mmol) of 3-isocyanatepropyltrimethoxysilane (manufactured by Kanto Chemical Co., Ltd.), 0.015 g (0.15 mmol) of triethylamine (manufactured by Kanto Chemical Co., Ltd.), and 12.0 g of meta-xylene hexafluoride were weighed. The reaction solution was stirred at 50°C for 6 hours. Methanol was added to the reaction solution after the reaction to separate the reaction solution. Since the lower layer was the target product, the solvent in the upper layer was removed. The washing process was repeated three times using methanol. The product was placed in an eggplant flask and dried under reduced pressure to remove the solvent, and the target perfluoropolyether group-containing alkoxysilane 2 (yield 87%, 10.2 g) was synthesized.
"Production Example 3": Perfluoropolyether group-containing alkoxysilane 3 synthesized in the following <Production Example 3>
<Production Example 3>
In a 30 mL eggplant flask containing a stirrer, a hydroxyl group-containing perfluoropolyether compound (product name "DOL-3000" manufactured by Sinochem, average molecular weight 3000) (4.0 mmol, 12 g), 3-isocyanatepropyltrimethoxysilane (4.8 mmol, 0.99 g), triethylamine (0.20 mmol, 0.020 g), and meta-xylene hexafluoride 12.0 g were weighed. The reaction solution was stirred at 50 ° C. for 6 hours. Methanol was added to the reaction solution after the reaction to separate the reaction. Since the lower layer is the target product, the solvent in the upper layer was removed. The washing process using methanol was repeated three times. The product was placed in an eggplant flask, and the solvent was removed by drying under reduced pressure, and the target perfluoropolyether-containing alkoxysilane 3 (yield 90%, 11.5 g) was synthesized.
(2) Second component: alkoxysilane containing two or more trialkoxysilyl groups. "Raw material A": bis(trimethoxysilyl)ethylene. "Raw material B": 1,6-bis(trimethoxysilyl)hexane. "Raw material C": Shin-Etsu Silicone Co., Ltd.'s "KBM-9659" (tris(trimethoxysilylpropyl)isocyanurate).
(3) Third component: Alkoxysilane containing one trialkoxysilyl group "KBM-7103": Shin-Etsu Silicone "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane)
n-Pro-Si(OMe) ₃ : _{CH3CH2CH2 - Si} (OMe) ₃ (Me is a methyl group)
C6F13Si: _{CF3CF2CF2CF2CF2CF2CF2 - Si (} OMe) ₃ (Me is a methyl _{group )}
(4) Fourth component: Tetraalkoxysilane hydrolysis condensate "MS-51": "Methyl silicate 51" manufactured by Colcoat Co., Ltd. (tetramethoxysilane hydrolysis condensate (average tetramer))
(5) Solvent: "Novec HFE-7200" (manufactured by 3M) (fluorine-based solvent)

Test Example 1
The water repellency of the cured films prepared in the examples and comparative examples was examined. More specifically, the contact angle (initial) of the cured film with water was measured at 25° C. The water contact angle was measured using a contact angle measuring device (product name: DropMaster 700, manufactured by Kyowa Interface Science Co., Ltd.) (the same applies to the following tests). The results are shown in Table 2.

Test Example 2
For the cured films produced in the Examples and Comparative Examples, a predetermined abrasion test was carried out, and then the water repellency was measured.
The abrasion test was carried out using an ultrasonic cleaner as follows. A dispersion of 10% by mass of Kanto loam (JIS test powder 1, type 8) was used and placed in a stainless steel container (SUS container). Then, a test piece (glass plate with cured film) was placed in the SUS container. The SUS container was placed in a commercially available ultrasonic cleaner, and the ultrasonic cleaner was operated to irradiate the dispersion with ultrasonic waves to treat the test piece. By treating the test piece in this way, the Kanto loam was violently shaken by shock waves generated by the bursting of vacuum bubbles generated in the dispersion by ultrasonic waves, and the Kanto loam collided with the test piece, causing damage to the test piece. The ultrasonic conditions were a frequency of 28 kHz and an output of 600 W. After 8 hours of irradiation, the test piece was collected, washed with pure water, and naturally dried. The contact angle of water with respect to the cured film obtained in this way after the test was measured. The results are shown in Table 2.

Test Example 3
A steel wool resistance test was carried out on each test piece. The cured film surface of the test piece was rubbed back and forth with steel wool (#0000) 300 times (load 1000 g) and then the water contact angle was measured. The results are shown in Table 2.

Comparing Example 1 and Comparative Example 1 in Table 2, it can be seen that when the first and second components are not included, the liquid repellency in the abrasion test decreases significantly. In particular, comparing Examples 1 to 5 and Comparative Examples 2 to 4, it can be seen that when the second component is not included, the liquid repellency in the abrasion resistance test decreases significantly.

In this way, the present invention has a film thickness of at least about 0.2 μm, and by containing a certain amount of polysubstituted alkoxysilane with an alkyl chain, the brittleness of the cured film is reduced by introducing not only Si-O-Si bonds, but also C-C bonds in particular, making it possible to increase durability against abrasion caused by impact with particles.

Example 13
As shown in Table 3, 0.60 g of perfluoropolyether group-containing alkoxysilane (Production Example 4), 0.3 g of bistrimethoxysilylethylene, 0.1 g of tetramethoxysilane hydrolysis condensate (product name "Methyl Silicate 51" manufactured by Colcoat Co., Ltd., average tetramer), and 99.0 g of fluorine-based solvent (product name "Novec HFE-7200" manufactured by 3M Co.) were weighed into a 200 mL beaker and stirred at room temperature for 1 hour to obtain a liquid composition. The liquid composition was applied to a cleaned glass plate and heated and cured in an oven at 170° C. for 30 minutes to produce a cured film. The film thickness at this time was about 0.2 μm.

Examples 14 to 16 and Comparative Example 5
A liquid composition was prepared in the same manner as in Example 13, except that the composition was changed as shown in Table 3. A cured film was produced using the liquid composition in the same manner as in Example 1.

The meanings of the abbreviations in Table 3 are as follows:
(1) First component: Perfluoropolyether group-containing alkoxysilane "Production Example 4": Perfluoropolyether group-containing alkoxysilane 4 synthesized in the following Production Example 4
<Production Example 4>
In a 30 mL eggplant flask equipped with a stirrer, a hydroxyl group-containing perfluoropolyether compound (product name "DOL-3000" manufactured by Sinochem, average molecular weight 3000 (6.0 mmol, 18.0 g), 3-isocyanatepropyltrimethoxysilane (7.2 mmol, 1.48 g), triethylamine (0.30 mmol, 0.030 g), and 18.0 g of meta-xylene hexafluoride were weighed. The reaction solution was stirred at 50°C for 6 hours. Methanol was added to the reaction solution after the reaction to separate the reaction. Since the lower layer was the target product, the solvent in the upper layer was removed. The washing process using methanol was repeated three times. The product was placed in an eggplant flask and dried under reduced pressure to remove the solvent, and the target perfluoropolyether-containing alkoxysilane 4 (yield 90%, 17.3 g) was synthesized.
"Production Example 5": Perfluoropolyether group-containing alkoxysilane No. 5 synthesized in the following <Production Example 5>
<Production Example 5>
In a 30 mL eggplant flask equipped with a stirrer, a hydroxyl group-containing perfluoropolyether compound (product name "DOL-4000" manufactured by Sinochem, average molecular weight 4000 (3.0 mmol, 12.0 g), 3-isocyanatepropyltrimethoxysilane (3.6 mmol, 0.74 g), triethylamine (0.15 mmol, 0.015 g), and meta-xylene hexafluoride 12.0 g were weighed. The reaction solution was stirred at 50 ° C. for 6 hours. Methanol was added to the reaction solution after the reaction to separate the reaction. Since the lower layer is the target product, the solvent in the upper layer was removed. The washing process using methanol was repeated three times. The product was placed in an eggplant flask and dried under reduced pressure to remove the solvent, and the target perfluoropolyether-containing alkoxysilane 5 (yield 87%, 10.2 g) was synthesized.
(2) Second component: alkoxysilane containing two or more trialkoxysilyl groups. "Raw material A": bis(trimethoxysilyl)ethylene. "Raw material B": 1,6-bis(trimethoxysilyl)hexane. "Raw material C": Shin-Etsu Silicone Co., Ltd.'s "KBM-9659" (tris(trimethoxysilylpropyl)isocyanurate).
(3) Third component: Alkoxysilane containing one trialkoxysilyl group "KBM-7103": Shin-Etsu Silicone "KBM-7103" (3,3,3-trifluoropropyltrimethoxysilane)
(4) Fourth component: Tetraalkoxysilane hydrolysis condensate "MS-51": "Methyl silicate 51" manufactured by Colcoat Co., Ltd. (tetramethoxysilane hydrolysis condensate (average tetramer))
(5) Solvent: "Novec HFE-7200" (manufactured by 3M) (fluorine-based solvent)

Test Example 4
The water repellency of the cured films prepared in each of the Examples and Comparative Examples was examined in the same manner as in Test Example 1. The results are shown in Table 4.

Test Example 5
The cured films prepared in the Examples and Comparative Examples were subjected to a predetermined abrasion test and then their water repellency was measured in the same manner as in Test Example 2. The results are shown in Table 4.

Test Example 6
A steel wool resistance test was carried out on each test piece in the same manner as in Test Example 3. The results are shown in Table 4.

Comparing Example 16 with Comparative Example 5, it is clear that the ultrasonic abrasion resistance is reduced when no poly-substituted alkyl chain-containing alkoxysilane is contained.
In addition, the film thickness is about 0.2 μm, and it is understood that by including a certain amount of poly-substituted alkoxysilane having an alkyl chain and introducing an alkyl chain bond in addition to the Si—O—Si bond, the brittleness of the cured film is reduced and the abrasion resistance in the Kanto loam soil is improved.

Claims (11)

The following ingredients:
(1) Perfluoropolyether group-containing alkoxysilane : 10 to 60% by mass,
(2) 1,6 bis-(trimethoxysilyl)hexane or bis(trimethoxysilyl)ethylene: 10 to 50% by mass,
(3) Alkoxysilanes containing one trialkoxysilyl group (excluding the alkoxysilanes of (1) above) : 0 mass% ; and
(4) Tetraalkoxysilane hydrolysis condensate: 1 to 15% by mass
A thermosetting composition comprising: The thermosetting composition according to claim 1, wherein the number average molecular weight of the alkoxysilane (1) is 3000 or more. 2. The thermosetting composition according to claim 1, comprising 50 to 200 parts by mass of the alkoxysilane of (2) per 100 parts by mass of the perfluoropolyether group-containing alkoxysilane. The thermosetting composition according to claim 1 , further comprising an organic solvent and being in a liquid state. 10. The thermosetting composition of claim 1 used to form a protective layer for a substrate exposed to sand or dust. A cured film formed by curing the thermosetting composition according to any one of claims 1 to 5. A laminate comprising the cured film according to claim 6 laminated on a substrate. An article comprising the cured film according to claim 6 laminated on a substrate. An optical product comprising the cured film according to claim 6 laminated on a substrate. The optical product according to claim 9, which is used outdoors. The optical product according to claim 10, wherein the substrate is a light, a lens, or a cover thereof for outdoor use.