JP2003238577A - Perfluoropolyether-modified silane, surface treating agent and antireflection filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a perfluoropolyether-modified silane which has water/oil repellency, parting properties, chemical resistance, lubricity, durability, antifouling properties and fingerprint wipe-off property due to absence of a polar group, is useful as a surface treating agent for coating the surfaces of various kinds of substrates, is applicable to an antireflection filter that has been formed with a cured coating film on the surface, is hardly stained, has the stain to be readily wiped off, is excellent in slipperiness on the surface, is hardly damaged and keeps these performances for a long period of time. <P>SOLUTION: The perfluoropolyether-modified silane is represented by formula (1) (Rf is a bifunctional straight-chain perfluoropolyether group; R is a 1-4C alkyl group or phenyl group; X is a hydrolyzable group; (n) is 0-2; (m) is an integer of 1-5; (a) is 2 or 3). <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel perfluoropolymer which is excellent in water and oil repellency, releasability, chemical resistance, lubricity, and the like, and is excellent in durability, stain resistance, especially fingerprint wipeability. The present invention relates to an ether-modified silane, a surface-treating agent containing the silane as a main component, and an antireflection filter having an antifouling layer having excellent antifouling properties and fingerprint wipeability, and particularly excellent durability.

[0002]

2. Description of the Related Art Generally, a compound containing a perfluoropolyether group has a very small surface energy,
It has water and oil repellency, chemical resistance, lubricity, releasability, and stain resistance. Utilizing its properties, it is widely used industrially for water and oil repellent antifouling agents such as paper and fibers, lubricants for magnetic recording media, oil repellents for precision equipment, release agents, cosmetics, and protective films. ing.

However, its properties indicate that it is non-adhesive and non-adhesive to other base materials at the same time, and it is difficult to form a coating and adhere to it even though it can be applied to the surface of the base material. Met.

On the other hand, a silane coupling agent is well known as a material for binding the surface of a substrate such as glass or cloth to an organic compound. The silane coupling agent has an organic functional group and a reactive silyl group (generally an alkoxysilyl group) in one molecule. The alkoxysilyl group undergoes a self-condensation reaction with water in the air to become a siloxane and forms a film. At the same time, it chemically and physically bonds to the surface of glass or metal to form a durable and strong film. Utilizing this property, silane coupling agents are widely used as coating agents on the surface of various substrates.

Japanese Patent Application Laid-Open No. 58-167597 discloses the following formula (2) which makes use of these characteristics.

[Chemical 3] (In the formula, R ¹ and R ² are alkyl groups having 1 to 4 carbon atoms, Q ¹ is CH ₂ CH ₂ CH ₂ or CH ₂ CH ₂ NHCH ₂ CH ₂ CH ₂ ,
h is an integer of 1 to 4 and i is 2 or 3. ) Is disclosed. However, in this compound, the part of the perfluoropolyether group is hexafluoropropylene oxide (HFP).
Since it is as short as 2 to 5 mer of O), the characteristics of the above perfluoropolyether group could not be sufficiently exhibited.

Further, in JP-A-58-122979, a water- and oil-repellent agent for a glass surface is represented by the following formula (3):

[Chemical 4] (In the formula, Rf ¹ is a polyfluoroalkyl group having 1 to 20 carbon atoms and may contain one or more ether bonds.
R ³ is a hydrogen atom or a lower alkyl group, A is an alkylene group, X ¹ is -CON (R ⁴⁾ -Q- or SO ₂ N (R ⁴⁾ -
Q- (provided that R ⁴ is a lower alkyl group, Q is a divalent organic group), Z is a lower alkyl group, Y is a halogen, an alkoxy group or R ⁵ COO- (provided that R ⁵ is a hydrogen atom or lower Represents an alkyl group), s is an integer of 0 or 1, t is 1 to 3
And u represents 0 or an integer of 1-2. ) Is presented, but in this case as well, the number of carbon atoms in the portion of the fluorine-containing group is as small as 1 to 20, and a sufficient effect is not obtained.

In particular, recently, with the increase in the number of buildings, the window glass is made maintenance-free, and the technique of "hardening stains" such as making the surface of the display hard to have fingerprints to improve the appearance and visibility. , The demand for "easy to remove dirt" technology is increasing year by year,
It has been desired to develop a material that can meet these requirements.

By utilizing the characteristics of the above-mentioned perfluoropolyether group-containing compound and silane coupling agent, a strong coating film is formed on the surface of the substrate, and water and oil repellency, antifouling property, chemical resistance, lubricity, and mold release are provided. As a surface treatment agent having excellent properties, a lens using a fluorine-containing silane compound represented by the following formula (4) in an antifouling layer is known (Japanese Patent Laid-Open No. 9-258003).

[0009]

[Chemical 5] (In the formula, Rf ′ is a linear or branched perfluoroalkyl group having 1 to 16 carbon atoms, X ′ is iodine or hydrogen, Y ¹ is hydrogen or a lower alkyl group, Z ¹ is a fluorine or trifluoromethyl group, R ¹² is a hydrolyzable group, R ¹³ is hydrogen or an inert monovalent organic group, and c ′, d ′ and f ′ are 0 to 20.
0 is an integer, g ′ is 0 or 1, p ′ and q ′ are integers from 0 to 2, and k ′ is an integer from 1 to 10. )

However, although the fluorine-containing silane compound represented by the above general formula (4) has a relatively large content of hydrolyzable groups in one molecule, it is present only at one end, so that it is particularly useful as a base material. There is a problem in terms of durability due to insufficient adhesion to, and when used as a surface treatment agent for lenses, the desired performance could not be maintained for a long period of time and could not be said to be appropriate. .

Further, in the case of an antireflection film which is generally provided on the surface of a visual recognition device or the like, contaminants such as hand marks, fingerprints, sweat, saliva, and hair styling materials are likely to adhere, and the adhesion causes surface reflection. There is a problem that contamination is more noticeable than in the case of a simple transparent plate, such as a change in the rate, and the displayed content is unclear due to the appearance of the attached material appearing white. It has been a long-standing problem to provide an antireflection film having excellent stain removability.

Conventionally, as an antireflection film for the purpose of improving stain resistance, etc., an antireflection layer formed of a single layer or a plurality of inorganic layers having a surface layer containing silicon dioxide as a main component formed by a PVD method is used. It is known that the surface thereof has a hardened layer made of an organic polysiloxane polymer or a polymer containing a perfluoroalkyl group (Japanese Patent Publication No. 6-5324).
Issue).

However, when human stains such as hand marks and fingerprints are attached, it is difficult to wipe them off with a tissue or the like, the stains are spread to a thin film, and the antireflection film is scratched when strongly rubbed, which is satisfactory. There was a problem that removal could not be achieved.

In general, the perfluoropolyether group-containing compound has the above-mentioned characteristics. As a compound utilizing these characteristics, in JP-A No. 11-29585, a perfluoro represented by the following formula (5) is shown. An antireflection film using a polyether-modified aminosilane as an antifouling layer is disclosed. However, although this antireflection film is excellent in water repellency, oil repellency, antifouling property, chemical resistance, lubricity, release property, etc., it is contained in the molecule of the perfluoropolyether-modified aminosilane used for the antifouling layer. It contains polar groups such as amide groups that have a high affinity for water, and the proportion (% by weight) of hydrolyzable groups in one molecule is small, so it takes time to cure and It has problems such as adhesiveness to the surface, and it has been desired to provide more sufficient performance for use as a surface treatment agent.

[Chemical 6] (In the formula, X ³ is a hydrolyzable group, R ⁶ is a lower alkyl group, R ^6
7 is a hydrogen atom or a lower alkyl group, Q ² is CH ₂ CH ₂ CH
₂ or _{CH 2 CH 2 NHCH 2 CH 2} CH 2, d is an integer of 6 to 50, e is 2 or 3, b and c are each an integer of 1 to 3. )

Further, Japanese Patent Application Laid-Open No. 2001-188102 discloses an antireflection film using a perfluoropolyether group-containing silane coupling agent represented by the following formula (6) as an antifouling layer. Although the perfluoropolyether group-containing silane coupling agent used for the stain layer does not contain a polar group, it cannot be said that the ratio of hydrolyzable groups in one molecule is sufficient, and it takes time to cure. Moreover, it cannot be said that it has sufficient performance for use as a surface treatment agent, such as poor adhesion to a substrate.

[Chemical 7] (However, Rf ² is a linear or branched perfluoroalkyl group having 1 to 16 carbon atoms, R is an alkyl group having 1 to 10 carbon atoms, k is an integer of 1 to 50, r is an integer of 0 to 6, j is 0
3 is an integer, i is an integer of 0 to 3, and 0 <j + i ≦ 6
Is. )

[0016] Therefore, it is difficult for the stains to adhere, and even when the stains are attached, the stains are not conspicuous, and the adhered stains including human stains such as hand marks and fingerprints can be easily wiped off with a tissue paper or the like. , It is hard to be scratched by the wiping operation, water droplets etc. can be easily shaken off, and anti-reflection that keeps such stain resistance, easy wipe removal property, scratch resistance and water repellency for a long time The development of filters was desired.

[0017]

[Patent Document 1] JP-A-58-167597

[Patent Document 2] JP-A-58-122979

[Patent Document 3] Japanese Patent Laid-Open No. 9-258003

[Patent Document 4] Japanese Patent Publication No. 6-5324

[Patent Document 5] Japanese Patent Laid-Open No. 11-29585

[Patent Document 6] Japanese Patent Laid-Open No. 2001-188102

[0018]

Therefore, in order to meet the above-mentioned demands, the present invention provides water and oil repellency, releasability, chemical resistance,
A novel perfluoropolyether-modified silane that has excellent lubricity, durability, stain resistance, especially fingerprint wipeability, and a surface treatment agent containing it as a main component, as well as stain resistance and fingerprint wipeability. In particular, it is an object of the present invention to provide an antireflection filter having an antifouling layer having excellent durability on its surface.

[0019]

Means for Solving the Problems and Modes for Carrying Out the Invention As a result of intensive studies conducted by the present inventor to meet the above demands, the following general formula (1)

[Chemical 8] (In the formula, Rf represents a divalent linear perfluoropolyether group, R represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, X
Is a hydrolyzable group, n is 0 to 2, m is an integer of 1 to 5, and a is 2 or 3. ) Is a new perfluoropolyether-modified silane, which is excellent in water and oil repellency, mold releasability, chemical resistance, lubricity, durability, antifouling property, especially fingerprint wiping property. As a result, they have found that they are suitable for forming a cured film on the surface of an antireflection filter, and completed the present invention.

Further, by forming an antifouling layer on the surface layer of the inorganic antireflection layer having a silicon dioxide inorganic layer, in this case, by using the silane of the above formula (1), the antifouling layer is formed. When the sliding angle with respect to oleic acid is 5 ° or less and the rate of change of the sliding angle after solvent cleaning with respect to the sliding angle before solvent cleaning is 10% or less, the surface energy is small and contaminants In addition to its low adhesive strength, its effect continues, and it also prevents contaminants such as fingerprints, sebum, sweat, and cosmetics from adhering to it, and even if it adheres, it can be easily wiped off, preventing stains from rubbing. It was found that an antireflection filter capable of preventing the peeling of the antireflection layer caused by scratches, which is less likely to be scratched on the surface of the antireflection layer with less deterioration of the function of the layer, and has completed the present invention. .

Accordingly, the present invention provides the perfluoropolyether-modified silane of the above general formula (1). Also,
The surface treatment agent containing the perfluoropolyether-modified silane and / or its partial hydrolyzed condensate as a main component, and the inorganic antireflection layer having a silicon dioxide-based inorganic layer as the surface layer, on the surface layer of oleic acid Fall angle 5
An antifouling layer having a degree of change of 10 ° or less and a change rate of the sliding angle after solvent cleaning with respect to the sliding angle before solvent cleaning is 10% or less, particularly silane of the above formula (1) and / or its partial hydrolysis-condensation product. There is provided an antireflection filter characterized by forming an antifouling layer using.

The present invention will be described in more detail below.
The perfluoropolyether-modified silane of the present invention is represented by the following general formula (1).

[0023]

[Chemical 9] (In the formula, Rf represents a divalent linear perfluoropolyether group, R represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, X
Is a hydrolyzable group, n is 0 to 2, m is an integer of 1 to 5, and a is 2 or 3. )

Here, Rf is a divalent linear perfluoropolyether group and includes perfluoropolyether groups of various chain lengths, but preferably perfluoropolyether having about 1 to 4 carbon atoms. It is a divalent linear perfluoropolyether having a group as a repeating unit. Examples of this divalent linear perfluoropolyether include those shown below. _{-CF 2 CF 2 O (CF 2} CF 2 CF 2 O) k CF 2 CF 2 - -CF 2 (OC 2 F 4) p - (OCF 2) q - k in the above structural formula, p and q are Each represents an integer of 1 or more. Specifically, 1 to 50, more preferably 10
A range of 40 is preferred. The molecular structure of perfluoropolyether is not limited to those exemplified above.

X represents a hydrolyzable group. Specific examples thereof include methoxy group, ethoxy group, propoxy group, alkoxy group such as butoxy group, methoxymethoxy group, alkoxyalkoxy group such as methoxyethoxy group, acyloxy group such as acetoxy group, alkenyloxy group such as isopropenoxy group, Examples thereof include halogen groups such as chloro group, bromo group and iodo group. Among them, alkoxy groups,
An organooxy group such as an alkenyloxy group and a chloro group are preferable, and a methoxy group, an ethoxy group, an isopropenoxy group and a chloro group are particularly preferable.

R is a lower alkyl group having 1 to 4 carbon atoms or a phenyl group, specifically, a methyl group, an ethyl group, a phenyl group and the like, among which a methyl group is preferable. n is 0
It is an integer of 2 and 1 is preferable. Further, m is an integer of 1 to 5, and 3 is preferable. a is 2 or 3, and 3 is preferable from the viewpoint of reactivity and adhesion to the substrate.

The molecular weight of the perfluoropolyether-modified silane compound of the present invention is not particularly limited, but stability,
From the viewpoint of ease of handling, the number average molecular weight is 500 to 20,000,
It is preferably 1,000 to 10,000.

Specific examples of the above perfluoropolyether-modified silane include those represented by the following structural formula. However, it is not limited to the following examples.

[0029]

[Chemical 10] (In the above formula, L is 1 to 50, p is 1 to 50, and q is 1 to 5
The sum of 0 and p + q is an integer of 10 to 100, and the repeating unit sequence in the formula is random. ) These can be used alone or in combination of two or more.

As the method for producing the perfluoropolyether-modified silane of the present invention, for example, a hydrosilane having a hydrolyzable group is added to a perfluoropolyether having α-unsaturated bonds at both ends and a platinum-based catalyst is used. The conventional method of hydrosilylation is available.

[0031]

[Chemical 11] (In the formula, Rf, R, X, n, m and a are the same as above.)

Here, as a method for synthesizing the perfluoropolyether having an α-unsaturated bond at both ends,
A perfluoropolyether modified with alcohols at both ends represented by the following formula (7) is reacted with an alkali metal such as K, Na and Li and an alkali metal hydroxide such as KOH, NaOH and LiOH to obtain the formula (8). It is obtained by producing a perfluoropolyether modified at both ends with alcoholate modified and then reacting the perfluoropolyether modified with both ends with alcoholate with an α-unsaturated bond-containing halide. _{Rf [(CH 2) n -OH} ] 2 (7) Rf [(CH 2) n -OM] 2 (8) ( wherein, n as defined above, M is an alkali metal.)

Since the perfluoropolyether-modified silane of the present invention contains no polar group in the molecule, which can be a negative factor in terms of characteristics, it has water and oil repellency, antifouling property, chemical resistance, lubricity and release property. It has excellent moldability and can be used as a surface treatment agent by coating the surface of various substrates. Further, at least two hydrolyzable groups such as hydrolyzable silyl groups are provided at both ends of the molecule, and both ends are firmly adhered to the base material, so that the effect is maintained for a long time. be able to.

The following are examples of applications using this function. Water- and oil-repellent agent: Paper, cloth, metal, glass, plastic, ceramic, etc. Release agent: For adhesive tape, resin molding dies, rolls, etc. Antifouling agent: Paper, cloth, metal, glass, plastic・ Ceramics, etc. Others: improving the fluidity and dispersibility of paint additives, resin modifiers, inorganic fillers, and improving the lubricity of tapes and films.

The perfluoropolyether-modified silane of the present invention is preferably used as a surface treatment agent and can form a cured film on the surface of an antireflection filter. The surface treating agent of the present invention contains, as a main component, the perfluoropolyether-modified silane represented by the formula (1) of the present invention and / or its partial hydrolysis-condensation product.

If desired, an organooxysilane hydrolysis condensation catalyst may be added to this surface treatment agent. Examples of the organooxysilane hydrolysis condensation catalyst include organic tin compounds such as dibutyltin dimethoxide and dibutyltin dilaurate, organic titanium compounds such as tetra n-butyl titanate, organic acids such as acetic acid and methanesulfonic acid, hydrochloric acid and sulfuric acid. Inorganic acids may be mentioned. In particular, acetic acid, tetra-n-butyl titanate, dibutyltin dilaurate and the like are preferable. The addition amount is a usual amount of catalyst, preferably 0.01 to 5 parts by weight, and particularly preferably 0.1 to 1 part by weight, based on 100 parts by weight of perfluoropolyether-modified silane and / or its partial hydrolysis-condensation product. preferable.

In the treating agent of the present invention, the perfluoropolyether-modified silane and / or its partial hydrolysis-condensation product may be used as it is, or may be diluted with an appropriate solvent. The solvent may be a mixed solvent of two or more kinds, and it is desirable that the perfluoropolyether-modified silane and / or its partial hydrolysis-condensation product be uniformly dissolved.

Examples of the solvent include fluorine-modified aliphatic hydrocarbon solvents such as perfluoroheptane and perfluorooctane, fluorine-modified aromatic hydrocarbon solvents such as m-xylene hexafluoride and benzotrifluoride, and methyl perfluoro. Fluorine-modified ether solvents such as butyl ether and perfluoro (2-butyltetrahydrofuran), fluorine-modified alkylamine solvents such as perfluorotributylamine and perfluorotripentylamine, hydrocarbons such as petroleum benzine, mineral spirits, toluene and xylene. Examples of the solvent include ketone solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone. From the viewpoint of solubility and wettability, a fluorine-modified solvent is preferable, and m-xylene hexafluoride, perfluoro (2-butyltetrahydrofuran), and perfluorotributylamine are particularly preferable.

As a method for forming a film, brush coating,
It can be processed by a known method such as dipping, spraying or vapor deposition. The optimum treatment temperature varies depending on the treatment method, but in the case of brush coating or dipping, for example, the range of room temperature to 120 ° C. is preferable. The treatment humidity is preferably performed under humidification in order to accelerate the reaction, but it is preferable to optimize the treatment humidity depending on the silane compound and other additives used.

As the base material for forming the film, various materials such as paper, cloth, metal and its oxide, glass, plastic, ceramics and ceramics can be used.

Here, as the article on which the cured film is formed on the surface, there are sanitary products (water repellent and antifouling) such as spectacle lenses, antireflection filters, optical members (fingerprint and sebum adhesion preventing coating), bathtubs and wash basins. coating),
Window glass for automobiles, trains, aircraft, etc., headlight covers, etc. (antifouling coating), building materials for outer walls (water repellent, antifouling coating), building materials for kitchen (oil antifouling coating), telephone boxes (water repellent, antifouling) Anti-staining and sticking paper coating), works of art (water- and oil-repellent coating to prevent fingerprints from sticking), compact discs, DV
D (fingerprint adhesion preventing coating) and the like are preferable. In particular, the surface treatment agent of the present invention is suitable for forming a coating film on an optical member such as a lens and a filter to impart antireflection property, antifouling property and the like.

The present invention further provides an antireflection filter, particularly an antireflection filter having a cured coating of the perfluoropolyether-modified silane of the above formula (1) and / or its partial hydrolysis-condensation product on its surface. In this case, the antireflection filter of the present invention has an antifouling layer formed on the surface of an antireflection layer having a silicon dioxide-based inorganic layer as a surface layer, and the antifouling layer has a sliding angle of 5 ° with respect to oleic acid. It is characterized in that the change rate of the falling angle after the solvent cleaning is 10% or less with respect to the falling angle before the solvent cleaning.

Here, the antifouling layer has a sliding angle with respect to oleic acid of 5 ° or less, preferably 3 ° or less, and a change rate of the sliding angle after solvent cleaning with respect to the sliding angle before solvent cleaning is 10%. It is preferably 5% or less. When the sliding angle with respect to oleic acid is larger than 5 °, the anti-staining property is poor, especially fingerprints and the like are apt to be attached, the stain-wiping property is poor, and the slipperiness on the surface during wiping may be poor. .

The change rate [(B−A) / A] × 100 of the falling angle B after solvent cleaning with respect to the falling angle A before solvent cleaning is 10
If it exceeds%, the durability may be poor in terms of anti-staining property and wipeability of fingerprints. The falling angle with respect to oleic acid is measured with a contact angle meter that is usually used. The solvent washing may be carried out by dipping in the corresponding solvent for 5 minutes and then gently pouring, and the solvent may be one used in ordinary washing, and examples thereof include HCFC-225 and nonafluorobutyl methyl ether.

The adhesive strength of the antifouling layer to the adhesive tape and the adhesive strength of the antifouling layer after solvent cleaning to the adhesive tape are preferably 0.2 N / 19 mm or less, respectively. The adhesive strength of the antifouling layer to the adhesive tape is 0.2
If it is larger than N / 19 mm, the fingerprint wiping property may be poor. The adhesive strength of the antifouling layer to the adhesive tape is measured with a polyester adhesive tape on the surface of the antifouling layer using a tensile tester at an angle of 180 ° and a peeling speed of 300 mm / min.

In this case, the antifouling layer is preferably formed using perfluoropolyether-modified silane,
In particular, a cured film of perfluoropolyether-modified silane represented by the following general formula (1) or a partially hydrolyzed product thereof as described above is preferable.

[Chemical 12] (In the formula, Rf represents a divalent linear perfluoropolyether group, R represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, X
Is a hydrolyzable group, n is 0 to 2, m is an integer of 1 to 5, and a is 2 or 3. )

Examples of the method for forming the antifouling layer include known methods such as brush coating, dipping, spraying and vapor deposition. The optimum treatment temperature varies depending on the treatment method. For example, in the case of brushing or dipping, the treatment temperature is preferably in the range of room temperature to 120 ° C. The treatment humidity is preferably performed under humidification in order to accelerate the reaction, but the treatment conditions are different depending on the silane compound and other additives used, and therefore it is preferable to optimize each time.

In such a coating operation, the perfluoropolyether-modified silane may be used as it is,
You may dilute with a suitable solvent and may use it. The solvent may be a mixed solvent of two or more kinds, and one in which the perfluoropolyether-modified silane is uniformly dissolved is preferable.

As the solvent, the same solvents as those mentioned above can be used. Further, if necessary, the same organooxysilane hydrolysis condensation catalyst as described above may be added.

The thickness of the antifouling layer is appropriately selected, but is usually 0.1 nm to 5 μm, and particularly preferably 1 to 100 nm.

The antireflection filter of the present invention is an antireflection filter in which an antifouling layer is formed on the surface layer of an inorganic antireflection layer having a silicon dioxide inorganic layer as a surface layer as described above. The inorganic antireflection layer is preferably provided directly on the supporting substrate or via an intermediate layer such as a hard coat layer. Figures 1 and 2 show this,
In the figure, 1 is a supporting substrate, 2 is an intermediate layer, 3 is an inorganic antireflection layer, and 4 is an antifouling layer.

Here, the inorganic antireflection layer is a portion having a substantial antireflection function, and in the present invention, it may have an appropriate structure of a single layer structure or a multilayer structure.
The surface layer of the antireflection film is a silicon dioxide-based inorganic layer.

Therefore, as the inorganic antireflection layer, for example, JP-A-58-46301 and JP-A-59-495 are used.
No. 01, No. 58-50401, and No. 1
It can be formed as an antireflection layer having a structure according to the prior art, as in the prior art based on JP-A-294709 and JP-B-6-5324.

The antireflection layer is, from the viewpoint of antireflection effect and the like,
A multi-layer structure is preferable, and a multi-layer structure in which one or more layers having a higher refractive index than the silicon dioxide-based inorganic layer of the surface layer is contained is particularly preferable. In that case, the thickness of each layer, the setting of the refractive index, and the like can be based on known techniques.

To form the inorganic antireflection layer, an inorganic oxide is used.
Substance, inorganic halide, inorganic compound composed of these
A thing can be used. As a specific example, SiO
₂, ZrO₂, Al₂O₃, Y₂O₃, TiO₂Inorganic oxidation such as
Thing, MgF₂, BaF₂, CaF ₂, LaF₂, LiF, N
aF, SrF₂Typical examples include inorganic halides such as
Can be mentioned.

The inorganic material for forming the antireflection layer is used in an appropriate state such as a solid material or a dispersion liquid in which one or more kinds thereof are mixed with a polymer for a binder or the like according to the following forming method. In that case, it is preferable to use a composition containing 30% by weight or more of an inorganic substance in terms of hardness and stain resistance. An appropriate polymer can be used as the binder polymer, and it is not particularly limited, but from the viewpoint of hardness and the like, various organosilicon compounds capable of forming polyorganosiloxane and hydrolysates thereof are preferable.

The inorganic antireflection layer is formed by various types of PVD (Physical Vapo) represented by, for example, a vacuum deposition method, a sputtering method, an ion plating method and the like.
rDeposition) method, or an appropriate thin film forming method such as a spin coating method, a dip coating method, a curtain flow coating method, a roll coating method, a spray coating method, or a fluid coating method typified by a flow coating method. .

[0058] The PVD method, such as inorganic halides such as inorganic oxides and MgF ₂ of SiO ₂ or the like exemplified above are preferably used, particularly the surface layer to become silicon dioxide-based inorganic layer, Ya height of the surface hardness From the viewpoint of adhesion of the antifouling layer,
What was formed in the layer containing silicon dioxide as a main component by the PVD method is preferable.

In addition, the inorganic antireflection layer may include a conductive layer which also exhibits a static electricity removing effect and an electromagnetic wave shielding effect in order to prevent adhesion of dust and the like due to charging.
Such a conductive layer may be, for example, a metal thin film of gold, silver, aluminum or the like, tin oxide, indium oxide, or a mixture thereof (I
It is formed as a transparent conductive film made of an inorganic oxide thin film such as TO). In the visible region, an inorganic oxide-based transparent conductive film that absorbs very little light is particularly preferable.

On the other hand, as the supporting base material, any suitable material may be used, but it is not particularly limited, but when forming an antireflection film by a liquid coating method or the like, a supporting base material made of glass or plastic is preferable. Used. In addition, in the figure, the antireflection filter formed by providing the inorganic antireflection layer 3 on one surface of the supporting substrate 1 is illustrated, but the inorganic antireflection layer 3 may be provided on one surface or both surfaces of the supporting substrate 1. .

When the supporting base material is a glass base material, it is preferable that the antireflection layer contains a material having a low refractive index such as MgF ₂ or CaF _{2 in} order to obtain a high reflection effect.
In the case of a plastic substrate, the antireflection layer is made of SiO 2.
It is preferable from the standpoint of durability etc. to include a material such as ₂ having a relatively low refractive index and high hardness. Examples of plastics include acrylic resins, diethylene glycol bisallyl carbonate resins, polycarbonate resins, polyester resins such as polyethylene terephthalate and unsaturated polyester, acetate resins such as triacetyl cellulose, styrene resins, polyvinyl chloride. Examples include resin.

The supporting base material may have a suitable form such as a film, a sheet and a plate, and its thickness is arbitrary. Further, the supporting base material may have a hard coat layer as an intermediate layer. In this case, as shown in FIG. 2, the antireflection filter has a form having the hard coat layer 2 between the antireflection layer 3 and the supporting substrate 1.

The hard coat layer can also be formed in a conventional manner. For example, a hard coat layer made of an organic silicon compound, particularly a cured product of an organic silicon compound represented by the following general formula (9) or a partially hydrolyzed condensate thereof is preferable. R ⁹ _f R ¹⁰ _g Si (OR ¹¹ ) _4-fg (9) (In the formula, R ⁹ and R ¹⁰ are an alkyl group, an alkenyl group, an aryl group, or a halogen group, an epoxy group, a glycidoxy group, an amino group, and a mercapto. Group, a methacryloxy group, a hydrocarbon group having a cyano group, etc., R ¹¹ is an alkyl group having 1 to 8 carbon atoms, an alkoxyalkyl group, an acyl group, an aryl group, etc. f and g are 0 or 1 and f + g is 0, 1 or 2.)

The hard coat layer is formed by a method of containing fine particles such as silica or metal oxide having an average particle diameter of 0.5 to 5 μm by a sol-gel method, or an appropriate method such as buffing, corona discharge or ion etching. It can also be attached as a method having an antiglare function by a method of forming an uneven surface having a center line average roughness of 0.01 to 0.5 μm.

Further, the supporting base material may be used as an intermediate layer, instead of or together with the hard coat layer, for example, improvement of adhesion, hardness, chemical resistance, durability, dyeability, etc. of the antireflection film. For this purpose, it may have an appropriate coat layer or may be surface-treated.

Incidentally, in order to improve the hardness, Japanese Patent Publication No. 50-28
092, Japanese Patent Publication No. 50-28446, Japanese Patent Publication No. 50-39449, Japanese Patent Publication No. 51-24368, Japanese Patent Publication No. 57-2735 and Japanese Patent Publication No. 52-112.
Appropriate materials for increasing the hardness described in Japanese Patent No. 698 can be used. Further, a method of coating an oxide of a metal such as titanium, aluminum, tin or the like or a silicon oxide, and addition of an acrylic crosslinked product such as a crosslinked product of pentamethyrritol of (meth) acrylic acid, etc. are also effective for improving hardness. .

[0067]

EXAMPLES The present invention will be specifically described below with reference to synthesis examples, examples and comparative examples, but the present invention is not limited to the following examples. In the following examples, parts are parts by weight.

[Synthesis Example] 160 g of perfluoropolyether having α-unsaturated bonds at both ends represented by the following formula (10), 80 g of metaxylene hexafluoride and chloroplatinic acid were converted into CH ₂ ═CH—Si ( _{CH 3) 2 OSi (CH 3} )
Was added dropwise trimethoxysilane 15g at 70 ° C. Drying under air atmosphere ₂ -CH = CH ₂ modified with catalyst 0.1 g, 8
After stirring and reacting for a period of time, the solvent was distilled off. As a result, 165 g of a colorless transparent liquid represented by the following formula (11) (viscosity: 4
5.5 cSt, specific gravity: 1.730, refractive index: 1.30
5) was obtained.

[Chemical 13]

[Example 1] PET film (thickness: 10
0 μm) On a substrate, 135 parts by weight of silica sol, γ-gly
Addition of 129 parts by weight of cidoxypropyltriethoxysilane
Water decomposition product, γ-chloropropyltrimethoxysilane 70
Apply 1 part by weight of hydrolyzate to the main ethanol solution.
Cloth, cured to form a hard coat layer with a thickness of 3 μm
It was On top of that, by sputtering method, SiO₂Layer, Ti
O₂Layer, SiO₂Layer, TiO₂Layer, SiO ₂5 layers of it
An antireflection layer is attached by sequentially stacking each with a λ / 4 optical thickness.
It was Next, the compound represented by the above formula (11) obtained in the synthesis example
Compound 1 was mixed with 0.2 g of perfluoroether-modified silane.
-Fluoro (2-butyltetrahydrofuran) 99.8
and the coating solution was prepared. This process
The liquid is applied to the antireflection layer by spin coating,
Let stand for 24 hours in an atmosphere of ℃ and 70% humidity to cure
An antifouling layer was formed. Using this sample piece, the following (1)
-(3) was evaluated. The results are shown in Table 1.

(1) Evaluation of surface characteristics A sliding angle contact angle meter (CA-A type manufactured by Kyowa Interface Science Co., Ltd.) was used to measure the sliding angle of oleic acid droplets having a diameter of 2 mm with respect to the antifouling layer. did. The measurement was carried out at five different points on the surface, and the average value was shown. Adhesive strength Polyester adhesive tape (Nitto Denko N
o. 31B, width 19 mm) was applied and the adhesive force was measured. The measurement was performed using a tensile tester at an angle of 180 ° and a peeling speed of 300 mm / min. (2) Evaluation of durability of coating film A sample piece was immersed in a fluorine-based solvent (AK-225 manufactured by Asahi Glass Co., Ltd.) for 5 minutes, taken out and dried, and then the falling angle and the adhesive force were measured by the methods described above and. The durability was evaluated. (3) Evaluation of antifouling property The index finger was pressed against the surface of the antifouling layer for 5 seconds to attach the fingerprint, and the fingerprint was wiped off with a dry cloth to evaluate the ease of wiping the fingerprint. Based on the following evaluation criteria, the average of 5 subjects was used as the evaluation. Ease of wiping fingerprints ○: Fingerprints can be lightly wiped △: Fingerprints are difficult to wipe but no marks are left ×: Fingerprints are hard to wipe and marks are left

[Comparative Examples 1 to 3] Compound 1 used in Examples
Evaluation was performed in the same manner as in the example except that the following compounds 2 to 4 were used instead of the perfluoropolyether-modified silane. The evaluation results are shown in Table 1.

[0072]

[Chemical 14]

[0073]

[Table 1]

The example has surface characteristics superior to those of the comparative example,
Moreover, it is excellent in durability and fingerprint wipeability.

[0075]

Since the perfluoropolyether-modified silane of the present invention does not contain a polar group in the molecule, which can be a negative factor in terms of characteristics, it has water and oil repellency, releasability, chemical resistance, lubricity, It has excellent durability, antifouling property, and fingerprint wiping property, and can be used as a surface treatment agent for coating various substrate surfaces, and can be applied to an antireflection filter having a cured coating formed on the surface. Further, the antireflection filter of the present invention has features that it is hard to stain, is easy to wipe off the stain, has good surface slipperiness and is not easily scratched, and has a long-term performance thereof. Can be used for various visual devices such as the above-mentioned visual recognition devices and various optical elements such as polarizing plates.

[0076]

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of an antireflection filter according to the present invention.

FIG. 2 is a cross-sectional view showing another example of the antireflection filter according to the present invention.

[Explanation of symbols]

1 Support substrate 2 Middle class 3 Inorganic antireflection layer 4 Antifouling layer

Continued front page    (72) Inventor Hirofumi Kinoshita             Gunma Prefecture Usui District, Matsuida Town             Shin-Etsu Chemical Co., Ltd. Silicone electronic materials             Inside the technical laboratory F term (reference) 2K009 AA05 AA15 BB02 BB06 BB11                       CC02 CC03 CC09 CC26 CC42                       DD02 DD03 DD06 EE05                 4H020 BA31                 4H049 VN01 VP02 VQ21 VR21 VR43                       VU21 VW02

Claims (7)

[Claims] 1. The following general formula (1): (In the formula, Rf represents a divalent linear perfluoropolyether group, R represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, X
Is a hydrolyzable group, n is 0 to 2, m is an integer of 1 to 5, and a is 2 or 3. ) A perfluoropolyether-modified silane represented by 2. The perfluoropolyether-modified silane according to claim 1, wherein the hydrolyzable group X is an organooxy group. 3. A surface treating agent comprising the perfluoropolyether-modified silane according to claim 1 or 2 and / or its partial hydrolysis-condensation product as a main component. 4. A sliding angle to oleic acid of 5 ° or less on the surface layer of an inorganic antireflection layer having a silicon dioxide inorganic layer as a surface layer, and after solvent cleaning to the sliding angle before solvent cleaning. An antireflection filter formed by forming an antifouling layer having a change rate of the falling angle of 10% or less. 5. The antireflection according to claim 4, wherein the adhesive strength of the antifouling layer to the adhesive tape and the adhesive strength of the antifouling layer after solvent cleaning to the adhesive tape are 0.2 N / 19 mm or less, respectively. filter. 6. The antireflection filter according to claim 4, wherein the antifouling layer is formed by using a perfluoropolyether-modified silane and / or a partial hydrolysis-condensation product thereof. 7. A perfluoropolyether-modified silane has the following general formula (1): (In the formula, Rf represents a divalent linear perfluoropolyether group, R represents an alkyl group having 1 to 4 carbon atoms or a phenyl group, X
Is a hydrolyzable group, n is 0 to 2, m is an integer of 1 to 5, and a is 2 or 3. 7. The antireflection filter according to claim 6, which is a compound represented by the formula (1).