WO2016136041A1

WO2016136041A1 - Hydrophilic film and production process therefor, laminate, protective material for surveillance camera, and surveillance camera

Info

Publication number: WO2016136041A1
Application number: PCT/JP2015/081384
Authority: WO
Inventors: 優介畠中
Original assignee: 富士フイルム株式会社
Priority date: 2015-02-27
Filing date: 2015-11-06
Publication date: 2016-09-01
Also published as: JP2016164265A

Abstract

A hydrophilic film comprising a siloxane binder and silica particles and having a surface which has a surface area difference ΔS and a surface roughness Ra that satisfy the following relationship 1; a process for producing the hydrophilic film; a laminate; a protective material for surveillance cameras; and a surveillance camera. ΔS≤0.5Ra relationship 1 In relationship 1, ΔS is the percentage determined with the following equation 2. ΔS=[(S_X-S₀)/S₀]×100 equation 2 In equation 2, S₀ represents the projected area of the hydrophilic film viewed from the perpendicular direction, and S_X represents the actual surface area of the hydrophilic film having the projected area expressed by S₀.

Description

Hydrophilic film and manufacturing method thereof, laminate, protective material for surveillance camera, and surveillance camera

The present invention relates to a hydrophilic film, a manufacturing method thereof, a laminate, a protective material for a surveillance camera, and a surveillance camera.

Equipment or building materials that are installed indoors or outdoors and used for a long period of time are used by being exposed to various environments, so that dust, dust, gravel, etc. gradually accumulate or get wet in rainwater during wind and rain. Equally, planned functions and performance may be impaired.

For example, in recent years, surveillance cameras are widely used for crime prevention in homes or as security systems for commercial buildings or outdoors. Surveillance cameras are stationary devices that include an imaging device such as a charge coupled device (CCD) camera and a protective cover, and are typically used for a long period of time once installed. The protective cover plays a role of protecting the imaging device from rainwater, gravel, or the like while having light transmittance that enables photographing.

The protective cover of the surveillance camera is required to be maintenance-free that does not require cleaning over a long period of time in order to always capture a stable image while protecting the imaging device. However, devices that are generally installed outdoors, such as surveillance cameras, tend to lose light transmittance gradually as water drops, dust, dust, or sand adhere to the surface of the device with long-term use. It is in. In the case of a surveillance camera, dust, dust, sand, etc. are likely to accumulate on the surface of the protective cover, and depending on the size or amount of the deposit, there is a concern that not only the light transmission will be significantly reduced, but also that the expected image cannot be recorded. Arise.
Therefore, a technique for preventing adhesion of water, dust, dust, sand, or the like to the surface of the device exposed to the outdoor environment has been studied.

In this respect, in addition to surveillance cameras, lighting and other equipment, signs, etc., building materials such as garage roofs for cars or bicycles, soundproof walls for roads, etc. are also used outdoors. It is the same.

As a technology related to the above, for example, in Japanese Patent No. 5250685, the water contact angle is 5 to 30 degrees, the centerline average roughness Ra of the surface is 0.01 to 0.06 μm, and the main component There is disclosed a camera cover having a hydrophilic coat of an inorganic material made of silicone on the outer surface of a resin substrate. This camera cover is supposed to prevent water droplets and dirt from adhering to ensure the sharpness of the image.

In addition, JP 2013-203774 A discloses an antifogging and antifouling agent for organic substrates containing an organosilica sol, an organic solvent, and boric acid. This anti-fogging and antifouling agent for organic substrates is said to impart an inorganic cured coating film having high hydrophilicity, hardness, adhesion strength to the organic substrate and water resistance and excellent antifouling and antifogging performance.

In addition to these, JP 2006-52352 A discloses a hydrolyzate of tetraalkoxysilane and / or a condensate thereof, a metal compound capable of interacting with a silanol group, an alkylene oxide unit, and an HLB (Hydrophile). An aqueous hydrophilization treatment agent comprising a nonionic surfactant having a Lipophile Balance) of 10 to 15, acidic colloidal silica, and a hydrophilic organic solvent is disclosed.
Japanese Patent Application Laid-Open No. 2000-212511 discloses a hydrophilic film provided with a cured coating of a hydrophilic inorganic paint containing a silane-modified surfactant having a terminal reactive group in an inorganic paint mainly composed of a silicone resin. A painted product is disclosed.

Equipment, components, or building materials that are installed outdoors and exposed to various environments such as wind and rain tend to deteriorate in their intended functions as dirt adheres to them. It has become customary to regularly clean or replace parts.
When the cover surface of the camera cover described in the above-mentioned Japanese Patent No. 5250685 is wiped by cleaning or the like, the surface of the cover is easily damaged, and the hydrophilicity may not be maintained after cleaning.
Also, surveillance cameras are often installed at high places, and may be installed using dedicated equipment. If the instrument comes into contact with a protective material or the like during installation, the surface of the protective material or the like may be damaged. Since the camera cover and the like described in the above-mentioned Japanese Patent No. 5250685 are not sufficiently scratch resistant, the camera cover and the like tend to be easily damaged during installation. These points are the organic base material coated with the anti-fogging and antifouling agent described in JP-A-2013-203774, the hydrophilic film described in JP-A-2006-52352, and JP-A 2000-2000. There is a similar tendency in the hydrophilic coating described in US Pat.

One embodiment of the present invention has been made in view of the above situation, and provides a hydrophilic film excellent in scratch resistance and hydrophilicity, a method for manufacturing the same, a laminate, a protective material for a surveillance camera, and a surveillance camera. The purpose is to achieve this purpose.

Specific means for solving the problems include the following aspects.
<1> A hydrophilic film containing a siloxane binder and silica particles, wherein the surface area difference ΔS and the surface roughness Ra on the surface satisfy the relationship of the following formula 1.
ΔS ≦ 0.5Ra Formula 1
In Equation 1, ΔS is a percentage obtained by Equation 2 below.
ΔS = [(S _X −S ₀ ) / S ₀ ] × 100 Equation 2
In Equation 2, S ₀ represents the projected area viewed from the perpendicular direction of the hydrophilic film, and S _X represents the actual surface area of the surface of the hydrophilic film in the projected area represented by S ₀ .

<2> The hydrophilic film according to <1>, wherein the surface roughness Ra is 100 nm or less.
<3> The hydrophilic film according to <1> or <2>, wherein the surface roughness Ra is 10 nm or less.
<4> The hydrophilic film according to any one of <1> to <3>, wherein the surface area difference ΔS is 0.1% or more.
<5> The hydrophilic film according to any one of <1> to <4>, further containing an antistatic agent.
<6> The hydrophilic film according to <5>, wherein at least one of the antistatic agents is an ionic surfactant.
<7> The hydrophilic film according to any one of <1> to <6>, further containing a surfactant.
<8> The hydrophilic film according to <7>, wherein the surfactant is a nonionic surfactant.
<9> The hydrophilic film according to any one of <1> to <8>, wherein the siloxane binder is a siloxane binder formed from a compound represented by the following general formula (1).

In general formula (1), R ¹ , R ² , R ³ , and R ⁴ each independently represent a monovalent organic group having 1 to 6 carbon atoms. n represents an integer of 2 to 20.

<10> The hydrophilic film according to any one of <1> to <9>, wherein an average primary particle diameter of the silica particles is 2 nm to 100 nm.

<11> A coating step in which a coating solution containing a siloxane binder and silica particles having an average primary particle size of 2 nm to 100 nm is coated on a substrate, and a coating film coated on the substrate by the coating step is 20 And a drying step of drying at a temperature of from 150 ° C. to 150 ° C., the ratio of the silica particles to the siloxane binder is 0.1 to 1.8 on a mass basis, the surface area difference ΔS on the surface and the surface roughness Ra, Manufacturing method of the hydrophilic film | membrane which manufactures the hydrophilic film | membrane satisfy | filling the relationship of following formula 1.
ΔS ≦ 0.5Ra Formula 1
In Equation 1, ΔS is a percentage obtained by Equation 2 below.
ΔS = [(S _X −S ₀ ) / S ₀ ] × 100 Equation 2
In Equation 2, S ₀ represents the projected area viewed from the perpendicular direction of the hydrophilic film, and S _X represents the actual surface area of the surface of the hydrophilic film in the projected area represented by S ₀ .

<12> The hydrophilic film according to <11>, further comprising a preparation step of preparing a coating liquid by mixing water, a siloxane oligomer, and silica particles having an average primary particle diameter of 2 nm to 100 nm. Production method.
<13> The method for producing a hydrophilic film according to <12>, wherein the preparation step further comprises preparing a coating solution by mixing a catalyst that promotes a condensation reaction of the siloxane oligomer.

<14> A laminate having a base material and the hydrophilic film according to any one of <1> to <10>.
<15> A surveillance camera protective material comprising the laminate according to <14>.
<16> The surveillance camera protective material according to <15>, wherein the base material in the laminate has a hemispherical shape, a semi-ellipsoidal shape, a planar shape, a prismatic shape, or a cylindrical shape.
<17> The protective material for a surveillance camera according to <15> or <16>, which is used for a surveillance camera installed outdoors.
<18> A surveillance camera comprising the surveillance camera protective material according to any one of <15> to <17>.

According to one embodiment of the present invention, a hydrophilic film excellent in scratch resistance and hydrophilicity, a method for producing the same, a laminate, a protective material for a surveillance camera, and a surveillance camera are provided.

Hereinafter, the hydrophilic film, the manufacturing method thereof, the laminate, the protective material for the surveillance camera, and the surveillance camera will be described in detail.
In the present specification, a numerical range indicated by using “to” means a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively.

<Hydrophilic membrane>
The hydrophilic film contains a siloxane binder and silica particles, and the surface area difference ΔS and the surface roughness Ra on the surface satisfy the relationship of the following formula 1.
ΔS ≦ 0.5Ra Formula 1
In Equation 1, ΔS is a percentage obtained by Equation 2 below.
ΔS = [(S _X −S ₀ ) / S ₀ ] × 100 Equation 2
In Equation 2, S ₀ represents the projected area viewed from the perpendicular direction of the hydrophilic film, and S _X represents the actual surface area of the surface of the hydrophilic film in the projected area represented by S ₀ . The unit of S ₀ and S _X may be the same unit (for example, μm).

A hydrophilic membrane refers to a membrane having a water contact angle of 40 ° or less.
The water contact angle is a value obtained by measuring 5 times by using a contact angle meter M553G-XM (manufactured by Shiro Sangyo Co., Ltd.) by dropping 1 μl of pure water on the surface of the hydrophilic membrane and calculating by the θ / 2 method. Arithmetic mean value.
The surface roughness Ra is a value measured according to JIS B0601: 2001 using an atomic force microscope (AFM).
S _X is a value measured by an atomic force microscope (AFM).

[Surface area difference ΔS]
The surface area difference ΔS of the hydrophilic film is expressed by the above formula 2.
The surface area difference ΔS indicates that the closer the numerical value approaches 0%, the smaller the difference between the numerical values of S _X and S ₀ . That is, as ΔS approaches 0%, the surface of the hydrophilic film becomes flat with less unevenness.
The actual surface area represented by S _X refers to the total area along the concavo-convex surface measured by an atomic force microscope (AFM). The projected area represented by S ₀ refers to an apparent area in the two-dimensional direction of the xy axis that is projected from the perpendicular direction of the hydrophilic film and ignores irregularities on the surface of the hydrophilic film. Specifically, the _value of the measurement range (projected area viewed from the perpendicular direction of the hydrophilic film) on the xy axis when measuring S _X can be used as S ₀ .
The surface area difference ΔS can be adjusted to a predetermined range depending on the average primary particle diameter of the silica particles, the ratio of the silica particles to the siloxane binder, and the drying conditions (specifically, drying temperature and drying time) at the time of film formation. .

The surface area difference ΔS is preferably 0.1% or more. The state where the surface area difference ΔS is 0.1% or more is a state where a part of the silica particles is exposed on the surface of the hydrophilic film. When the surface of the film is in this state, the hydrophilicity and scratch resistance of the silica particles can be effectively expressed.
The surface area difference ΔS is more preferably 0.1% or more and 50% or less, and further preferably 0.1% or more and 5% or less from the same point as described above.

[Surface roughness Ra]
The surface roughness Ra can be measured according to JIS B0601: 2001 using an atomic force microscope (AFM) (manufactured by Seiko Instruments Inc., SPA-400).

The surface roughness Ra is preferably 100 nm or less, and more preferably 10 nm or less, from the viewpoint of scratch resistance.

[Relationship between surface area difference ΔS and surface roughness Ra]
In the hydrophilic film, the surface area difference ΔS and the surface roughness Ra satisfy the relationship of the following formula 1.
ΔS ≦ 0.5Ra Formula 1

When the surface area difference ΔS and the surface roughness Ra satisfy the relationship of Formula 1, the film has excellent scratch resistance and hydrophilicity.
In the above formula 1, for example, when it is assumed that the surface roughness Ra is 10 nm, the surface area difference ΔS is 5% or less. That is, in the case of the surfaces having the same surface roughness, it is shown that the one with less unevenness is more effective for achieving both scratch resistance and hydrophilicity.

[Water contact angle]
The water contact angle of the hydrophilic film is preferably 30 ° or less, more preferably 25 ° or less, and further preferably 15 ° or less. When the water contact angle is in the above range, the surface of the hydrophilic film is more excellent in hydrophilicity. The water contact angle is as described above.

The reason why the hydrophilic film can achieve the above effect is not clear, but is presumed as follows.
In the hydrophilic film, the surface area difference ΔS and the surface roughness Ra satisfy the relationship of the above formula 1, so that the hydrophilic film has a surface with small unevenness. Therefore, for example, when the surface of the hydrophilic film is rubbed with a contaminant such as gravel attached, the area where the hydrophilic film and the contaminant are in contact with each other is increased, and the stress at the time of contact is dispersed. Further, since the unevenness is small, the accumulation of contaminants can be suppressed. As a result, the hydrophilic film is considered to be a film that is difficult to be scratched and soiled (that is, excellent in scratch resistance and antifouling property).
Further, since the hydrophilic film contains a siloxane binder and silica particles (preferably, the siloxane binder is formed by a condensation reaction of siloxane oligomers), the surface of the silica particles in the formed film has a high density of silanol groups. Exists. Therefore, it is considered that the formed hydrophilic film is excellent in hydrophilicity.
Conventionally, as for the physical properties such as hydrophilicity of a film, for example, the larger the numerical value of the surface roughness Ra, the more the hydrophilicity appears (for example, Wenzel's formula), and the smaller the numerical value of the surface roughness Ra (surface). It was thought that the hydrophilicity etc. were inferior so that it became flat.
However, it is considered that excellent hydrophilicity can be obtained even if the numerical value of the surface roughness Ra is small, by adopting the above-described configuration for the hydrophilic film of one embodiment of the present invention.
From the above, it is considered that the hydrophilic film is excellent in scratch resistance and hydrophilicity.

[Siloxane binder]
The hydrophilic film contains at least one siloxane binder.
When the hydrophilic film contains a siloxane binder, the hydrophilic film can hold silica particles, and both scratch resistance and hydrophilicity can be achieved.

The siloxane binder preferably contains at least one compound obtained by a condensation reaction of a siloxane oligomer.

As the siloxane oligomer, a partial hydrolysis condensate obtained by using one kind of silane compound and a partial cohydrolysis condensate obtained by using two or more kinds of silane compounds can be used. Hereinafter, these compounds may be referred to as “partial (co) hydrolysis condensates”.
The silane compound is a compound having a hydrolyzable silyl group and / or a silanol group. The silyl group is hydrolyzed to become a silanol group, and the silanol group is dehydrated and condensed to produce a siloxane bond.

In this case, as a partial (co) hydrolysis condensate, dimers of the silane compound as described above (1 mol of water was allowed to act on 2 mol of the silane compound to remove 2 mol of alcohol to form disiloxane units. Compound) to 100-mer, preferably dimer to 50-mer, more preferably dimer to 20-mer, and a part (co) of which two or more silane compounds are used as raw materials. It is also possible to use hydrolysis condensates.

Such a partial (co) hydrolysis condensate may be a compound commercially available as a silicone alkoxy oligomer (for example, commercially available from Shin-Etsu Chemical Co., Ltd.). Based on the law, a compound produced by reacting hydrolyzable silane compound with less than an equivalent amount of hydrolyzed water and then removing by-products such as alcohol and hydrochloric acid may be used.

The siloxane oligomer preferably has an alkoxysilyl group at the molecular end. As the siloxane oligomer having an alkoxysilyl group at the molecular end, a tetrafunctional or bifunctional siloxane oligomer can be used, including a tetrafunctional siloxane oligomer having four alkoxysilyl groups in the molecule.
Among these siloxane oligomers, tetrafunctional siloxane oligomers are preferable from the viewpoint of the reactivity of the condensation reaction.

Of the tetrafunctional siloxane oligomers, compounds represented by the general formula (1) (hereinafter also referred to as “specific siloxane compounds”) are preferable.
That is, the hydrophilic film preferably contains at least one siloxane binder formed from the compound represented by the general formula (1).
A hydrophilic film | membrane can improve the hydrophilic property of a surface more by including the siloxane binder formed from the compound represented by General formula (1).

The monovalent organic group having 1 to 6 carbon atoms in R ¹ , R ² , R ³ and R ⁴ may be linear, branched or cyclic. . Examples of the monovalent organic group include an alkyl group and an alkenyl group, and an alkyl group is preferable.
Examples of the alkyl group when R ¹ , R ² , R ³ , or R ⁴ represents an alkyl group include, for example, a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, an n- Examples thereof include a pentyl group, an n-hexyl group, and a cyclohexyl group.
When the monovalent organic group of R ¹ to R ⁴ in the specific siloxane compound, preferably the alkyl group has 1 to 6 carbon atoms, the specific siloxane compound has good hydrolyzability. From the viewpoint of better hydrolyzability, R ¹ to R ⁴ are more preferably each independently an alkyl group having 1 to 4 carbon atoms, and more preferably an alkyl group having 1 or 2 carbon atoms. More preferably.

N in the general formula (1) is an integer of 2 to 20. By setting n in the range of 2 to 20, a coating solution for a hydrophilic film containing a specific siloxane compound (for example, when a hydrophilic film is formed by coating, a coating solution for forming a hydrophilic film; the same applies hereinafter). The viscosity can be in an appropriate range. Moreover, the reactivity of a specific siloxane compound can be controlled in a preferable range. n is preferably 3 to 12, and more preferably 5 to 10.
When n is 20 or less, the viscosity of the coating solution does not become too high, and a hydrophilic film with high uniformity is formed by coating. On the other hand, when n is 2 or more, the reactivity of the siloxane compound is easily controlled, and for example, a hydrophilic film having excellent surface hydrophilicity is formed by coating.
Hereinafter, examples of the specific siloxane compound are described by R ¹ to R ⁴ and n in the general formula (1). However, it is not limited to these exemplary compounds.

The siloxane oligomer is hydrolyzed at least partially by coexisting with water. A hydrolyzate of a siloxane oligomer is a compound in which at least a part of an alkoxy group bonded to a silicon atom of a siloxane oligomer is substituted with a hydroxy group by a reaction between the siloxane oligomer and water, and a hydroxy group that is a hydrophilic group. Due to the group, for example, a hydrophilic film formed through coating and drying becomes a film having good surface hydrophilicity.
In the hydrolysis reaction, it is not always necessary to react all the alkoxy groups of the siloxane oligomer, but for example, from the viewpoint that the hydrophilicity of the coating film obtained by applying and drying the coating liquid for forming a hydrophilic film becomes better. It is preferable that more alkoxy groups are hydrolyzed.
The amount of water required for the hydrolysis is the same molar amount as the alkoxy group of the siloxane oligomer, but it is preferable to carry out the hydrolysis with a large excess of water from the viewpoint of allowing the hydrolysis reaction to proceed efficiently.

As described above, the siloxane binder contained in the hydrophilic film is obtained by condensing at least a part of the hydroxy groups of the hydrolyzate of the siloxane oligomer and condensing the siloxane oligomer.
The hydrophilic film may contain only one type of siloxane binder or two or more types.

The weight average molecular weight of the siloxane oligomer is preferably in the range of 300 to 1500, more preferably in the range of 500 to 1200.

The weight average molecular weight can be measured by gel permeation chromatography (GPC). Specifically, HLC-8120GPC, SC-8020 (manufactured by Tosoh Corporation) is used, TSKgel, SuperHM-H (manufactured by Tosoh Corporation, 6.0 mm ID × 15 cm) are used as columns, and tetrahydrofuran is used as an eluent. It can be measured using (THF). The conditions are as follows: the sample concentration is 0.5 mass%, the flow rate is 0.6 ml / min, the sample injection amount is 10 μl, the measurement temperature is 40 ° C., and a differential refractive index (RI) detector is used. it can. The calibration curves are “polystyrene standard sample TSK standard” manufactured by Tosoh Corporation: “A-500”, “F-1”, “F-10”, “F-80”, “F-380”, “A-2500”. , “F-4”, “F-40”, “F-128”, and “F-700” prepared from 10 samples can be used.

The content of the siloxane binder in the hydrophilic film is preferably 1% by mass to 80% by mass, more preferably 3% by mass to 75% by mass with respect to the total solid content of the hydrophilic film, and 5% by mass to 70%. More preferred is mass%. When the content of the siloxane binder is within the above range, the water contact angle on the surface of the hydrophilic film is suppressed to be low, and the film is difficult to get dirty, and even when dirty, the film can be easily removed.

[Silica particles]
The hydrophilic film contains at least one kind of silica particles.
The silica particles have a function of further improving hydrophilicity while enhancing the scratch resistance of the hydrophilic film. That is, the silica particle plays a role as a hard filler, and the hydroxyl group on the particle surface acts to contribute to hydrophilicity.

Examples of the silica particles include fumed silica and colloidal silica.
Fumed silica can be obtained by reacting a compound containing a silicon atom with oxygen and hydrogen in the gas phase. Examples of the silicon compound used as a raw material include silicon halide (for example, silicon chloride).
Colloidal silica can be synthesized by a sol-gel method in which a raw material compound is hydrolyzed and condensed. Examples of the raw material compound for colloidal silica include alkoxy silicon (for example, tetraethoxysilane) and halogenated silane compound (for example, diphenyldichlorosilane).

The shape of the silica particles is not particularly limited, and examples thereof include a spherical shape, a plate shape, a needle shape, a bead shape, or a shape in which two or more of these are combined. The term “spherical” as used herein includes not only true spheres but also spheroids and oval shapes.

Examples of the silica particles include AEROSIL (registered trademark) series manufactured by Evonik Degussa, Snowtex (registered trademark) series (for example, Snowtex O) manufactured by Nissan Chemical Industries, and Nalco manufactured by Nalco Chemical. (Registered trademark) series (for example, Nalco 8699 etc.) etc. are mentioned.

The silica particles preferably have an average primary particle diameter of 100 nm or less, from the viewpoint of easy adjustment to a range in which the surface area difference ΔS and the surface roughness Ra of the hydrophilic film satisfy the relationship of the above formula 1, and are 50 nm or less. More preferably, it is more preferably 30 nm or less, and particularly preferably 15 nm or less. Moreover, the minimum of the average primary particle diameter of a silica particle is although it does not specifically limit, 2 nm or more is preferable from a viewpoint similar to the above.
Silica particles having different sizes or shapes may be mixed.

The average primary particle diameter of the silica particles is obtained by observing with a transmission electron microscope, measuring the projected area of the particles for 300 or more particles from the obtained photograph, and determining the equivalent circle diameter from the projected area. In addition, when the shape of a silica particle is not spherical, it calculates | requires using another method, for example, a dynamic light scattering method.

The content of silica particles is preferably 5% by mass to 95% by mass, more preferably 10% by mass to 90% by mass, and still more preferably 20% by mass to 85% by mass with respect to the total solid content of the hydrophilic film. . When the content of the silica particles is within the above range, a hydrophilic film having hydrophilicity can be formed while being excellent in hardness, scratch resistance, and impact resistance.

Moreover, it is preferable that content of a silica particle is the range of a fixed ratio with respect to content of the above-mentioned siloxane binder. That is, the ratio of the silica particles to the siloxane binder in the hydrophilic film is preferably 0.1 to 1.8, more preferably 0.1 to 1.5, more preferably 0.1 More preferably, it is -1.2.
When the ratio of the silica particles to the siloxane binder is in the above range, the relationship between the surface area difference ΔS of the hydrophilic film and the surface roughness Ra can be easily adjusted to a range satisfying the above formula 1.

In addition to the siloxane binder and silica particles, the hydrophilic film may contain an antistatic agent, a surfactant, a catalyst for promoting the condensation reaction of the siloxane oligomer, and other components.

[Antistatic agent]
The hydrophilic film preferably contains at least one antistatic agent. By containing an antistatic agent, antistatic properties are imparted to the hydrophilic film. By containing the antistatic agent together with a siloxane binder and silica particles, the effect of preventing adhesion to contaminants is great, and the antifouling property is dramatically improved. improves.

The antistatic agent can be appropriately selected from compounds having an antistatic function, and may be either a compound showing surface activity or a compound not showing surface activity. Examples of the antistatic agent include ionic surfactants and metal oxide particles.
Since an ionic surfactant has a property of easily segregating in the vicinity of the film surface of a coating film when a hydrophilic film is formed by coating, for example, the effect can be expected with a small amount of addition. In addition, metal oxide particles may be required to be added in a relatively large amount in order to impart antistatic properties to the hydrophilic film, but are suitable for enhancing the scratch resistance of the hydrophilic film because it is an inorganic substance. ing.

Examples of ionic surfactants include alkyl sulfates (eg, sodium dodecyl sulfate, sodium lauryl sulfate, etc.), alkyl benzene sulfonates (eg, sodium dodecyl benzene sulfonate, sodium lauryl benzene sulfonate, etc.), alkyl sulfosuccinates. Anionic surfactants such as acid salts (eg, sodium di (2-ethylhexyl) sulfosuccinate) and alkyl phosphates (eg, sodium dodecyl phosphate); Cationics such as alkyltrimethylammonium salts and dialkyldimethylammonium salts Surfactants; and amphoteric surfactants such as alkylcarboxybetaines.
It is known that if an ionic surfactant is added excessively in the film, the electrolytic mass in the system increases and silica particles are aggregated. The composition used in combination with has been avoided. However, the knowledge that an ionic surfactant exhibits an antifouling function against pollutants is obtained, and one embodiment of the present invention is based on such knowledge, and an ionic surfactant is used as an antistatic agent in a hydrophilic film. It is a preferable aspect to contain the surfactant. By including an ionic surfactant, the antifouling property and water washability of the hydrophilic membrane are further enhanced.

Although it does not specifically limit as a metal oxide particle, A tin oxide particle, an antimony dope tin oxide particle, a tin dope indium oxide particle, a zinc oxide particle, etc. are mentioned.
Moreover, the metal oxide particles may be used by mixing particles having different sizes, shapes, or materials. The shape of the particles is not particularly limited, and may be spherical, plate-shaped, or needle-shaped.
When the metal oxide particles have a large refractive index and a large particle size, loss due to excessive scattering of transmitted light is likely to occur. Therefore, the average primary particle size is preferably 100 nm or less, and preferably 50 nm or less. More preferably, it is more preferably 30 nm or less.
Regarding the average primary particle diameter of the metal oxide particles, when the particle shape is substantially spherical, such as a spherical shape or a cross-sectional ellipse, the dispersed particles are observed with a transmission electron microscope, and 300 or more particles are obtained from the obtained photograph. It is obtained by measuring the projected area of the particles and determining the equivalent circle diameter from the projected area. In addition, when the shape of a metal oxide particle is not spherical, it calculates | requires using another method, for example, a dynamic light scattering method.

When an ionic surfactant is used as the antistatic agent, the content of the ionic surfactant is preferably 50% by mass or less, more preferably 20% by mass or less, based on the total solid content of the hydrophilic film. Preferably, 10 mass% or less is more preferable. When the content of the ionic surfactant is within the above range, the antifouling property of the hydrophilic film can be enhanced while suppressing aggregation of the silica particles. Moreover, it is preferable that content of an ionic surfactant is 0.05 mass% or more from a viewpoint of the antifouling property improvement effect of a hydrophilic film | membrane by including an ionic surfactant.

When using metal oxide particles as an antistatic agent, the content of metal oxide particles is preferably 70% by mass or less, more preferably 60% by mass or less, and more preferably 50% by mass with respect to the total solid content of the hydrophilic film. % Or less is more preferable. When the content of the metal oxide particles is within the above range, the antistatic property can be effectively imparted without impairing the film formability when the hydrophilic film is formed by coating. Moreover, it is preferable that content of a metal oxide particle is 1 mass% or more from a viewpoint of the antifouling property improvement effect of a hydrophilic film | membrane by including a metal oxide particle.

[Surfactant]
It is preferable that the hydrophilic film further contains a surfactant. In the hydrophilic film, the surfactant is contained together with the siloxane binder and the silica particles, thereby exhibiting the ability to prevent the adhesion of contaminants (particularly gravel, etc.) and excellent antifouling properties.
In addition, the surfactant here does not include the compound having an antistatic function (for example, an ionic surfactant) mentioned as the above-mentioned antistatic agent.

The surfactant may be a combination of an antistatic agent and a surfactant, regardless of whether the antistatic agent has surface activity. When the antistatic agent is a compound that does not exhibit surface activity, it is preferable to contain a surfactant from the viewpoint of water detergency. When the antistatic agent is a compound showing surface activity, it is preferable to contain a surfactant separately from the antistatic agent from the viewpoint of further improving the antifouling property.

When the hydrophilic film contains a surfactant, not only the antifouling property of the hydrophilic film is increased, but also the coating property when the hydrophilic film is formed by coating, for example, can be improved. The surface tension of the coating film also decreases, and the uniformity of the coating film is further improved.

Examples of the surfactant include nonionic surfactants.
When an ionic surfactant is used as the aforementioned antistatic agent, if the ionic surfactant is excessively added to the film as described above, the electrolytic mass in the system increases and silica particles are aggregated. Since it is easy to invite, it is preferable to use a nonionic surfactant together. However, the nonionic surfactant does not necessarily need to be used in combination with the ionic surfactant, and may contain a nonionic surfactant alone as the surfactant.

Examples of the nonionic surfactant include polyalkylene glycol monoalkyl ether, polyalkylene glycol monoalkyl ester, polyalkylene glycol monoalkyl ester / monoalkyl ether, and the like. Specific examples of the nonionic surfactant include polyethylene glycol monolauryl ether, polyethylene glycol monostearyl ether, polyethylene glycol monocetyl ether, polyethylene glycol monolauryl ester, and polyethylene glycol monostearyl ester.

The content of the surfactant in the hydrophilic film is preferably 0.5% by mass or more, and more preferably 1.0% by mass or more based on the total solid content of the hydrophilic film.
Moreover, 50.0 mass% or less is preferable with respect to the total solid of a hydrophilic film | membrane, content of surfactant is more preferable, 40.0 mass% or less is more preferable, and 30.0 mass% or less is further more preferable. When the content of the surfactant is 30.0% by mass or less, the phenomenon that the surfactant is segregated on the film surface is suppressed, which is advantageous in that the hardness of the film is maintained well.

[Catalyst for promoting condensation reaction of siloxane oligomer]
The hydrophilic film may contain at least one catalyst that promotes the condensation reaction of the siloxane oligomer (condensation promoting catalyst). The effect of the condensation accelerating catalyst will be described later.

There is no restriction | limiting in particular as a condensation promotion catalyst, For example, an acid catalyst, an alkali catalyst, and an organometallic catalyst are mentioned.
Examples of the acid catalyst include nitric acid, hydrochloric acid, sulfuric acid, acetic acid, chloroacetic acid, formic acid, oxalic acid, and toluenesulfonic acid.
Examples of the alkali catalyst include sodium hydroxide, potassium hydroxide, and tetramethylammonium hydroxide.
Examples of organometallic catalysts include aluminum chelate compounds such as aluminum bis (ethylacetoacetate) mono (acetylacetonate), aluminum tris (acetylacetonate), and aluminum ethylacetoacetate diisopropylate; zirconium tetrakis (acetylacetonate) And zirconium chelate compounds such as zirconium bis (butoxy) bis (acetylacetonate); titanium chelate compounds such as titanium tetrakis (acetylacetonate) and titanium bis (butoxy) bis (acetylacetonate); and dibutyltin diacetate , Organotin compounds such as dibutyltin dilaurate, and dibutyltin dioctiate.
Among these catalysts, nitric acid is preferable as the acid catalyst, sodium hydroxide is preferable as the alkali catalyst, and an aluminum chelate compound or a zirconium chelate compound is preferable as the organometallic catalyst. Among these catalysts, an organometallic catalyst is more preferable, and an aluminum chelate compound is particularly preferable.

The content of the condensation accelerating catalyst in the hydrophilic membrane is preferably from 0.1% by mass to 20% by mass, more preferably from 0.2% by mass to 15% by mass, based on the total solid content of the hydrophilic membrane. More preferably, the content is 3% by mass to 10% by mass. When the content of the condensation accelerating catalyst is within the above range, it is easy to form a hydrophilic film having scratch resistance. Moreover, it is excellent also in the formation property of a hydrophilic film | membrane.

[Other ingredients]
In addition to the above-described components, the hydrophilic film can further contain additives such as a binder component (binder additive component) other than the siloxane binder, if necessary, as other components.

As a binder addition component, for example, polyurethane, acrylic resin, polyphosphate, metaphosphate, etc., terminal polar groups (for example, hydroxyl group, carboxy group, phosphate group, sulfonate group, amino group, etc.) The binder component which has is mentioned.
By including the binder additive component in the hydrophilic film, the adhesion between the hydrophilic film and the substrate (particularly, the polycarbonate substrate) is improved.
Among the above binder-added components, from the viewpoint of adhesion between the hydrophilic film and the substrate, a binder-added component having a hydroxyl group, a carboxy group, or a phosphate group at the terminal is preferable. Polyurethane, acrylic resin, and polyphosphorus Acid salts are more preferred.

Although it does not specifically limit as a polyurethane, For example, the polyurethane which has a soft segment / hard segment structure comprised by a polyol skeleton and a polyisocyanate skeleton is mentioned.
A commercially available polyurethane may be used. For example, Takerak (registered trademark) W series, WS series, WD series manufactured by Mitsui Chemical Co., Ltd., Permarin (registered trademark) series manufactured by Sanyo Chemical Industries, Ltd., Ucoat (Registered trademark) series, Uprene (registered trademark) series, and the like.
Examples of acrylic resins include acrylic acid homopolymers (polyacrylic acid), acrylic acid derivatives such as acrylic acid and esters of acrylic acid, and methacrylic acid derivatives such as methyl methacrylate.
Among these acrylic resins, polyacrylic acid is preferable, polyacrylic acid having a weight average molecular weight of 20 to 5 million is preferable, polyacrylic acid having 10,000 to 2 million is more preferable, and polyacrylic acid having 250,000 to 1 million is preferable. Acid is more preferred.
Examples of the polyphosphate include sodium polyphosphate and potassium polyphosphate.
The weight average molecular weight can be measured by the method described above.

The content of the binder additive component in the hydrophilic film is preferably 0.001% by mass to 0.1% by mass and more preferably 0.001% by mass to 0.01% by mass with respect to the total solid content of the hydrophilic film. Preferably, 0.002% by mass to 0.008% by mass is more preferable. When the content of the binder additive component is within the above range, it is easy to form a hydrophilic film having excellent adhesion to the substrate.

It can be said that the hydrophilic film contains silicon and oxygen as main components of the solid content, and has a small carbon content. By reducing the carbon content, for example, a hydrophilic film formed by forming a coating film using a hydrophilic film-forming coating solution and drying it can be used in various environments exposed to outdoor wind and rain. Even when placed on the film, the influence of light and heat on the film can be kept to a minimum.
In the hydrophilic film, the proportion of carbon in the total solid content is preferably 3% by mass or less, more preferably 2.5% by mass or less, and further preferably 2% by mass or less.

When the hydrophilic film contains an organic compound containing carbon, the organic compound containing carbon is preferably a compound having a low weight average molecular weight. Specifically, in the hydrophilic film, the content of the organic compound having a weight average molecular weight of 1100 or more is preferably 0.2% by mass or less, and 0% by mass with respect to the total solid content of the hydrophilic film. That is, it is more preferable that it is not contained except for inevitable impurities.
When the content of the organic compound having a weight average molecular weight of 1100 or more is in the above range, the compatibility of the solid content in the hydrophilic film becomes better, and the coating film is formed using the hydrophilic film forming coating solution. The film formability can be further improved.
The “organic compound having a weight average molecular weight of 1100 or more” does not include the above-described siloxane binder.
Moreover, a weight average molecular weight can be measured by the above-mentioned method.

The thickness of the hydrophilic film is preferably in the range of 20 nm to 600 nm, more preferably in the range of 50 nm to 350 nm, and still more preferably in the range of 100 nm to 250 nm.

[Physical properties of hydrophilic film]
The hydrophilic film is excellent in scratch resistance and hydrophilicity. As a result, the hydrophilic film is suitable as a protective material for objects installed outdoors (for example, surveillance cameras, protective materials for protecting lighting, garage roofing materials, protective materials for signs, wall materials). By attaching a hydrophilic film, adhesion of contaminants is suppressed. Further, since the hydrophilic film has good hydrophilicity, when a contaminant adheres to the surface, it can be easily removed by washing away the contaminant (for example, washing with water). There is also an effect that it is easy to be washed away by rain water or the like during rainy weather.
In addition, since the hydrophilic film is excellent in scratch resistance, it is possible to prevent the film from being damaged when the contaminant is wiped off.
The physical properties of the hydrophilic film are listed below.

[Surface resistance]
The surface resistance value of the hydrophilic film is preferably 1 × 10 ¹² Ω / square or less, more preferably 1 × 10 ¹¹ Ω / square or less, and 1 × 10 ¹⁰ Ω / square or less. Is more preferable. When the surface resistance of the hydrophilic film is within the above range, the hydrophilic film has a more excellent antifouling property.
The surface resistance value is measured using Hiresta MCP-HT450 (manufactured by Mitsubishi Chemical Analytech).

[Integral sphere transmittance]
The hydrophilic film is preferably excellent in light transmittance. From such a viewpoint, the integrating sphere transmittance of the hydrophilic film (wavelength (λ) = average value of integrating sphere transmittance at 300 nm to 1200 nm) is 95% or more. Preferably there is.
The integrating sphere transmittance here is an average value obtained by measuring the integrating sphere transmittance for each wavelength of 5 nm in the wavelength region of 300 nm to 1200 nm and averaging the measured values (the integrating sphere at the wavelength (λ) = 300 nm to 1200 nm). (Average value of transmittance).
The integrating sphere transmittance is more preferably 95.5% or more.
Integral sphere transmittance of the hydrophilic membrane is determined by measuring the integral sphere transmittance of the base material on which the hydrophilic membrane is not formed and the base material on which the hydrophilic membrane is formed with reference to the white plate of barium sulfate. By subtracting the integrated sphere transmittance of the base material on which the hydrophilic film is not formed from the integrated sphere transmittance of the formed base material, the light transmittance improvement for the base material is calculated.
The integrating sphere transmittance is measured using a transmission spectrophotometer with an integrating sphere. Specifically, for example, an apparatus in which an integrating sphere attachment device (ISR-2200, manufactured by Shimadzu Corporation) is connected to an ultraviolet-visible infrared spectrophotometer (UV-3600, manufactured by Shimadzu Corporation), or ultraviolet-visible red Measured using light having a wavelength of 300 nm to 1400 nm with a device such as an external spectrophotometer (UV-3600, manufactured by Shimadzu Corporation) connected to a versatile large sample chamber (MPC-3100, manufactured by Shimadzu Corporation) The
The more transmittance improvement obtained by measurement, the better the transparency (low reflectivity), and the light transmittance improvement (wavelength (λ) = 400 nm to 1400 nm) is preferably 1% or more, 1.5% or more is more preferable, and 1.8% or more is particularly preferable.
The light transmittance improvement is obtained as an average value in the wavelength region of 400 nm to 1400 nm.

[Transmissivity]
The transmittance of the hydrophilic membrane (average value at λ = 300 nm to 1200 nm) is preferably 70% or more, and more preferably 80% or more. The transmittance of the hydrophilic membrane was determined by measuring the integrating sphere transmittance of the base material on which the hydrophilic membrane was formed with reference to the integrating sphere transmittance of the base material on which the hydrophilic membrane was not formed.
The transmittance is a value measured by a self-recording spectrophotometer (UV2400-PC, manufactured by Shimadzu Corporation).

<Method for producing hydrophilic membrane>
The hydrophilic film is produced by applying a coating liquid containing a siloxane binder and silica particles having an average primary particle diameter of 2 nm or more and 100 nm or less to the substrate, and applying the coating liquid on the substrate by the coating process. And a drying step of drying the coated film at a temperature of 20 ° C. or higher and 150 ° C. or lower.
Moreover, it is preferable that the manufacturing method of a hydrophilic film | membrane has the preparation process which prepares a coating liquid further.
In the hydrophilic film produced by the production method of one embodiment of the present invention, the ratio of the silica particles to the siloxane binder is 0.1 to 1.8 on a mass basis, and the surface area difference ΔS and the surface roughness on the surface. Ra satisfies the relationship of the following formula 1.
ΔS ≦ 0.5Ra Formula 1
In Equation 1, ΔS is a percentage obtained by Equation 2 below.
ΔS = [(S _X −S ₀ ) / S ₀ ] × 100 Equation 2
In Equation 2, S ₀ represents the projected area viewed from the perpendicular direction of the hydrophilic film, and S _X represents the actual surface area of the surface of the hydrophilic film in the projected area represented by S ₀ .

[Preparation process]
It is preferable that the manufacturing method of a hydrophilic film | membrane has a preparation process which prepares a coating liquid.
The coating liquid used in the method for producing the hydrophilic film can be appropriately selected from coating liquids containing a siloxane binder and silica particles having an average primary particle diameter of 2 nm to 100 nm. In the preparation process shown below, It is preferable to use the prepared coating solution.
In the preparation step, a coating solution is prepared by mixing water, a siloxane oligomer, and silica particles having an average primary particle size of 2 nm to 100 nm. Moreover, it is preferable that a preparation process prepares a coating liquid by further mixing the catalyst (condensation promotion catalyst) which accelerates | stimulates the condensation reaction of a siloxane oligomer.

For example, the coating liquid is prepared by bringing a siloxane oligomer into contact with water to prepare a mixed liquid containing a hydrolyzate of the siloxane oligomer, and then adding silica particles having an average primary particle diameter of 2 nm to 100 nm to the mixed liquid. The method of doing is mentioned.
The hydrolysis reaction of the siloxane oligomer proceeds even at room temperature (25 ° C.), but in order to promote the reaction, after preparing a mixed solution by bringing the siloxane oligomer into contact with water, the obtained mixed solution is heated at 30 ° C. to 50 ° C. You may heat to about degreeC. A longer reaction time for the hydrolysis reaction is preferred because the reaction proceeds more. For this reason, from the viewpoint of sufficiently allowing the hydrolysis reaction to proceed, it is also preferable to carry out the reaction for 1 hour to 36 hours in a heated state.
In addition, by allowing a catalyst for promoting the hydrolysis reaction of the siloxane oligomer to coexist in the mixed solution, it is possible to obtain a hydrolyzate of the siloxane oligomer necessary for hydrophilicity even for about half a day.
The hydrolysis reaction of the siloxane oligomer is a reversible reaction. Therefore, when water is removed from the mixed solution, the hydrolyzate of the siloxane oligomer starts with a condensation reaction between hydroxy groups and proceeds. Therefore, when a hydrolyzate of a siloxane oligomer is obtained by a hydrolysis reaction in a mixed solution containing a siloxane oligomer and preferably a large excess of water, the hydrolyzate is not isolated but remains in the mixed solution. It is preferable to prepare a coating solution by adding silica particles.
Since the condensation reaction of the hydrolyzate of the siloxane oligomer proceeds in the coating solution, the coating solution contains a siloxane binder.

The addition amount of the siloxane oligomer is preferably 0.1% by mass to 50% by mass, more preferably 0.5% by mass to 30% by mass, and more preferably 0.5% by mass to 20% by mass with respect to the total mass of the coating solution. % Is more preferable.
The amount of silica particles added is preferably 30% by mass or less, more preferably 20% by mass or less, and still more preferably 10% by mass or less with respect to the total mass of the coating solution. When the proportion of the silica particles in the coating solution is within the above range, it is advantageous in that the dispersibility of the silica particles in the solution is enhanced and aggregation is prevented.

If necessary, the coating solution may further contain a condensation accelerating catalyst, an antistatic agent, a surfactant, and a binder additive component.

When the coating solution contains the siloxane oligomer and the condensation accelerating catalyst, the condensation reaction of the siloxane oligomer is promoted and the formation of the siloxane binder is promoted. Thereby, a hydrophilic film | membrane becomes a film | membrane excellent in scratch resistance.

The condensation accelerating catalyst is the same as the condensation accelerating catalyst in the hydrophilic membrane described above, and the preferred embodiment is also the same.

The amount of the condensation accelerating catalyst added to the coating solution is preferably 0.1% by mass to 20% by mass, more preferably 0.2% by mass to 15% by mass, and 0.3% with respect to the total solid content of the coating solution. More preferably, the content is 10% by mass to 10% by mass. When the content of the condensation accelerating catalyst is within the above range, a hydrophilic film having scratch resistance is easily formed. Moreover, it is excellent also in the formation property of a hydrophilic film | membrane.

The condensation accelerating catalyst is also useful for hydrolysis of siloxane oligomers. Here, the hydrolysis reaction and condensation reaction of the alkoxy group bonded to silicon of the siloxane oligomer are in an equilibrium relationship. If there is a lot of moisture in the system, the reaction proceeds in the direction of hydrolysis, and if the moisture in the system is low, the reaction Proceeds in the direction of condensation. Since the catalyst for promoting the condensation reaction of the alkoxy group promotes the reaction in both directions, the hydrolysis reaction can be promoted in a state where there is a lot of moisture in the system. The presence of the catalyst allows the hydrolysis of the siloxane oligomer to proceed more reliably under milder conditions.
In this case, it is efficient if the catalyst used for the hydrolysis reaction of the siloxane oligomer is kept in the system as it is to be used as a component of the coating liquid for forming a hydrophilic film and used as it is as a condensation catalyst for the siloxane oligomer.

The coating liquid may contain an antistatic agent. Since the coating liquid contains an antistatic agent, it is possible to form a hydrophilic film imparted with antistatic properties, and the formed hydrophilic film is antifouling because the adhesion of contaminants to the film is suppressed. Will improve.
As an antistatic agent, it is the same as the antistatic agent in the above-mentioned hydrophilic film | membrane, A preferable aspect is also the same.

When an ionic surfactant is used as the antistatic agent, the content of the ionic surfactant in the coating liquid is preferably 1.0% by mass or less based on the total mass of the coating liquid. More preferably, it is 8 mass% or less, More preferably, it is 0.5 mass% or less. When the proportion of the ionic surfactant in the coating solution is within the above range, the antifouling property of the hydrophilic film can be enhanced while suppressing aggregation of the silica particles.
When metal oxide particles are used as the antistatic agent, the content of the metal oxide particles in the coating solution is preferably 30% by mass or less, and 20% by mass or less with respect to the total mass of the coating solution. More preferably, it is more preferably 10% by mass or less. When the ratio of the metal oxide particles in the coating liquid is within the above range, the dispersibility of the metal oxide particles in the liquid is enhanced, which is advantageous in preventing aggregation and the like.

When the coating solution contains a surfactant, the wettability of the coating solution to the substrate is improved.
The surfactant is the same as the surfactant in the hydrophilic film described above, and the preferred embodiment is also the same.

The content of the surfactant in the coating solution is preferably 0.01% by mass or more, preferably 0.02% by mass or more, and more preferably 0.03% by mass or more with respect to the total mass of the coating solution. When the content of the surfactant is within the above range, the wettability to the substrate is more excellent. Moreover, 15 mass% or less is preferable with respect to the total solid of a coating liquid, content of surfactant is 10.0 mass% or less, More preferably, it is 5 mass% or less.

The coating liquid may contain a binder additive component. When the coating solution contains a binder addition component, a hydrophilic film with improved adhesion to the substrate can be formed.
As a binder addition component, it is the same as the binder addition component in the above-mentioned hydrophilic film | membrane, A preferable aspect is also the same.

The content of the binder additive component in the coating solution is preferably 0.001% by mass to 0.1% by mass, more preferably 0.001% by mass to 0.01% by mass, based on the total solid content of the coating solution. 0.002 mass% to 0.008 mass% is more preferable.

In the above, when an antistatic agent, a surfactant and a binder additive component are added, a part or all of them may be added in the step of obtaining a hydrolyzate of a siloxane oligomer.

It is preferable that the coating liquid does not contain a photopolymerization initiator and a thermal polymerization initiator. By not using a photopolymerization initiator and a thermal polymerization initiator, light irradiation or heat treatment can be omitted when forming the hydrophilic film. Moreover, it is preferable not to contain a photoinitiator and a thermal polymerization initiator from a viewpoint of the storage stability of a coating liquid.

The conditions for preparing the coating liquid are not particularly limited, but from the viewpoint of suppressing the aggregation of silica particles due to pH and the concentration of coexisting components, the silica particles are preferably added in the latter half of the process of preparing the coating liquid. More preferably, it is added last. Here, when the silica particles are used as a dispersion (specifically, a dispersion in which silica particles are previously dispersed in an aqueous solvent, or a commercially available silica particle dispersion), the pH of the dispersion and the solvent used in the coating solution It is preferable to adjust the pH of the dispersion of silica particles and the solvent of the coating solution to the same or close values by making the pH both acidic or basic.

[Coating process]
The manufacturing method of a hydrophilic film | membrane has an application | coating process which apply | coats to a base material the coating liquid containing a siloxane binder and a silica particle with an average primary particle diameter of 2 nm or more and 100 nm or less.
There is no restriction | limiting in particular as a coating method which apply | coats a coating liquid to a base material, For example, the well-known method of spray coating, brush coating, roller coating, bar coating, dip coating (dip coating) can be applied.

The coating amount of the coating liquid is not particularly limited, and can be appropriately set in consideration of operability and the like according to the solid content concentration in the coating liquid, the desired film thickness, and the like. The coating amount of the coating solution is preferably 0.1 mL / m ² to 1000 mL / m ² , more preferably 0.5 mL / m ² to 500 mL / m ² , and 1 mL / m ² to 200 mL / m ^2. ² is more preferable. When the coating amount of the coating liquid is within the above range, the coating accuracy is good and the surface area difference ΔS and the surface roughness Ra can be easily adjusted.

[Drying process]
The manufacturing method of a hydrophilic film | membrane has a drying process which dries the coating film apply | coated on the base material by the application | coating process at the temperature of 20 to 150 degreeC.

In the drying step, the coating film formed by applying the coating liquid is heated to a temperature of 20 ° C. or more and 150 ° C. and dried, whereby the surface area difference ΔS and the surface roughness Ra are expressed by the above formula 1 Thus, the formed hydrophilic film is excellent in scratch resistance and hydrophilicity.

The coating film may be dried using a heating device. The heating device is not particularly limited as long as it can be heated to a target temperature, and any known heating device can be used. As the heating device, an oven, an electric furnace, or the like, or a heating device uniquely manufactured according to the production line can be used.

The coating film can be dried using, for example, the above-described heating device so that the surface temperature of the coating film is 20 ° C. or higher and 150 ° C. or lower. The drying time can be, for example, a heating time of about 1 minute to 60 minutes.
The drying condition of the coating film is preferably a drying condition in which the coating film is heated at a surface temperature of 20 ° C. or higher and 150 ° C. or lower for 1 minute to 60 minutes, and is heated at a surface temperature of 40 ° C. or higher and 150 ° C. or lower for 1 minute to 60 minutes. More preferably, the drying condition is heating for 1 to 30 minutes at a surface temperature of 60 ° C. to 150 ° C., and the drying condition is heating for 1 to 10 minutes at a surface temperature of 90 ° C. to 150 ° C. Particularly preferred.
The drying of the coating film is preferably performed in a short time at a high temperature from the viewpoint of maintaining the surface shape of the coating film.
The surface temperature can be measured with an infrared thermometer.

The coating film after drying preferably has a film thickness of 20 nm or more. When the film thickness is 20 nm or more, the coating film after drying is more excellent in scratch resistance.
The coating film after drying preferably has a thickness of 20 nm to 600 nm, more preferably 50 nm to 350 nm, and particularly preferably 100 nm to 250 nm.

<Laminated body>
The laminate has at least a base material and the hydrophilic film according to one embodiment of the present invention described above.
Since the laminate has the hydrophilic film according to the embodiment of the present invention, the laminate is excellent in scratch resistance and hydrophilicity.

[Hydrophilic membrane]
The hydrophilic film | membrane in a laminated body is the hydrophilic film | membrane of one Embodiment of the above-mentioned this invention, A preferable aspect is as above-mentioned.

[Base material]
There is no restriction | limiting in particular as a base material which forms a laminated body, It can select suitably from various materials, such as glass, a resin material (plastics material), a metal, and ceramics, and can use it.

Glass is widely used as a substrate, and is suitable as a substrate for forming a laminate. When glass is used as the substrate, condensation of hydroxy groups on silicon occurs even with the hydroxy groups on the glass surface, thereby forming a film having better adhesion to the substrate.
A resin material is also suitable as the base material. For example, a resin material is often used for a base material such as a protective material for a monitoring camera. Among the resin materials, polycarbonate and polymethyl methacrylate are preferable because they are excellent in durability against light and heat.
The substrate may be a composite material. As a base material, for example, any of a composite material including glass and a resin material, in which glass and a resin material are mixed and combined, or a resin composite material in which a plurality of types of resin materials are kneaded or bonded may be used.

The thickness of the substrate is not particularly limited and may be appropriately selected depending on the intended use or intended purpose, and may be, for example, 0.05 mm to 10 mm.

Laminates are for surveillance cameras, protective materials for protecting lighting (so-called protective covers), roof materials for garages for vehicles such as automobiles and bicycles, protective materials for signs such as road signs, and highway shoulder installations. Or it is used suitably for uses, such as a noise barrier for railroads.
Especially, it can apply suitably for the use of the protective material (what is called a camera cover) for the surveillance camera which protects an imaging device.

<Protective material for surveillance cameras>
The surveillance camera protective material includes at least the laminate according to the embodiment of the present invention.
Since the laminate has the hydrophilic film according to one embodiment of the present invention described above, it is excellent in scratch resistance and hydrophilicity. Accordingly, the protective material for a surveillance camera is, for example, an imaging device for a surveillance camera that is easily exposed to a harsh outdoor environment for a long period of time, has excellent light transmission and transparency over a long period of time, and requires long-term durability. It is useful as a protective material for protecting the imaging surface.

As the shape of the substrate in the laminate, a hemispherical shape, a semi-ellipsoidal shape (including a so-called dome shape), a planar shape, a prismatic shape, or a cylindrical shape is preferable. Here, the ellipsoid refers to a shape obtained by extending the ellipse into three dimensions so as to be symmetric with respect to the xy plane, the yz plane, and the zx plane.
Moreover, there is no restriction | limiting in particular in the size of a base material, What is necessary is just to select suitably according to a use, a use purpose, etc. For example, in the case of a hemispherical shape, the diameter of the circle of the opening surface may be in the range of 10 mm to 1000 mm, for example.

As the material of the base material, the same material as the base material in the above-described laminate of one embodiment of the present invention can be used. Among the materials of the base material, a resin material is preferable and polycarbonate and polymethyl methacrylate are more preferable from the viewpoint of adhesion to the hydrophilic film of one embodiment of the present invention.

<Monitoring camera>
The surveillance camera includes the monitoring camera protective material according to the embodiment of the present invention described above for protecting the imaging apparatus. Therefore, the surveillance camera is excellent in scratch resistance and hydrophilicity. Therefore, the surveillance camera is useful as a surveillance camera that is easily exposed to a harsh outdoor environment for a long period of time, maintains excellent light transmission and transparency over a long period of time, and requires long-term durability.

Hereinafter, one embodiment of the present invention will be described more specifically by way of examples. However, one embodiment of the present invention is not limited to the following examples unless it exceeds the gist thereof.

(Example 1)
-Preparation of coating solution-
To 81.07 g of ethanol, 3.06 g of a siloxane oligomer (compound 1 in Table 1; compound represented by general formula (1) (n = 5)) and aluminum bis (ethylacetoacetate) mono (acetylacetonate) 0.94 g of a 1% by mass isopropanol solution (catalyst for promoting condensation reaction of siloxane oligomer) was added and mixed.
To the obtained solution, 114.80 g of an aqueous solution in which 0.057 g of polyethylene glycol monolauryl ether (ethylene oxide repeat number 15; nonionic surfactant) was dissolved was gradually added and stirred at room temperature for 12 hours or more. did. Thereby, application mother liquid B1 was prepared by hydrolyzing a siloxane oligomer.
Next, 7.36 g of ethanol, 12.58 g of water, and 0.0056 g of polyethylene glycol monolauryl ether (15 ethylene oxide repeats; nonionic surfactant) are added to 19.99 g of the coating mother liquor B1. It was. Thereafter, 0.0011 g of sodium di (2-ethylhexyl) sulfosuccinate (an ionic surfactant as an antistatic agent) was further added for dilution. This solution was further mixed with 0.85 g of a 1% by mass isopropanol solution of aluminum bis (ethylacetoacetate) mono (acetylacetonate) (catalyst for promoting condensation reaction of siloxane oligomer) and silica particles 1 (Snowtex® O). The average primary particle size: 10 nm to 15 nm, manufactured by Nissan Chemical Industries, Ltd.) was added as a solid content and 1.4 g was added to prepare a coating solution. In addition, since the condensation reaction of the hydrolyzate of siloxane oligomer proceeds in the coating solution, the coating solution contains a siloxane binder.

-Production of camera cover-
Next, after forming the coating film by spray-coating the prepared coating liquid on one side of an acrylic plate (planar shape) [plate size: 300 mm × 450 mm, thickness: 1 mm, manufactured by Ebara Kogyo Co., Ltd .; The film was dried at 65 ° C. for 2 minutes to obtain a hydrophilic film having a thickness of 130 mm (0.13 μm). For spray application, a spray atomizer (Preval, manufactured by Precision Valve) was used. Here, condensation of the siloxane oligomer contained in the hydrophilic film proceeds, and the hydrophilic film contains a siloxane binder. The ratio of silica particles to siloxane binder in the hydrophilic film is 0.5 on a mass basis.
As described above, a camera cover (laminate) for a surveillance camera, which was an acrylic plate having a hydrophilic film, was produced.

-Evaluation-
The following measurement or evaluation was performed using the produced camera cover for a surveillance camera. The evaluation results are shown in Table 2 below.

(1) Surface roughness Ra and surface area difference ΔS
The surface roughness Ra and the surface area difference ΔS were calculated by obtaining three-dimensional data by measuring the surface shape with an atomic force microscope (AFM). In addition, the following formula 2 was used for the calculation of ΔS.
ΔS = [(S _X −S ₀ ) / S ₀ ] × 100 Equation 2
In Equation 2, S ₀ represents the projected area viewed from the perpendicular direction of the hydrophilic film, and S _X represents the actual surface area of the surface of the hydrophilic film in the projected area represented by S ₀ .

Specifically, the laminate on which the hydrophilic film is formed is cut to a size of 1 cm × 1 cm, set on a horizontal sample stage on a piezo scanner, the cantilever is approached to the sample surface, and the atomic force is reduced. When it reached the working area, it was scanned in the XY directions. During scanning, irregularities on the surface of the hydrophilic film were captured by the displacement of the piezo in the Z direction. The measurement was performed at 512 points × 512 points in a surface area of 5 μm × 5 μm. Three-dimensional data was obtained from the measured results. Note that the actual surface area that is actually measured by the cantilever and S _X, the area of the measurement range (5μm × 5μm) was S _0.
The relationship between the surface area difference ΔS and the surface roughness Ra was determined using the numerical values obtained above. In Table 2, it is represented by ΔS / Ra, and satisfies the formula 1 when the value of ΔS / Ra is 0.5 or less.

(2) Scratch resistance Steel wool model # 0000 was cut to a size of 1 cm ² , piled on the hydrophilic film side of the laminate, and rubbed 10 times over the steel wool with a predetermined load, and evaluated according to the following evaluation criteria. did. Among the evaluation criteria A to E, A and B were allowed.

<Evaluation criteria>
A: The hydrophilic film was not scratched even at a load of 30 g.
B: The hydrophilic film was scratched with a load of 20 g.
C: The hydrophilic film was scratched with a load of 10 g.
D: The hydrophilic film was scratched with a load of 5 g.
E: The hydrophilic film was scratched with a load of 1 g.

(3) Water contact angle Using a contact angle meter M553G-XM (manufactured by Shiro Sangyo Co., Ltd.), 1 μl of pure water was dropped on the surface of the hydrophilic film, and the contact angle [°] was measured by the θ / 2 method. The average of the values obtained by repeated measurements was taken as the water contact angle.
The water contact angle was set to an allowable value of 40 ° or less.

(4) Antifouling property After applying a natural ocher pigment (manufactured by Holbein Co., Ltd.) evenly on the surface of the hydrophilic film of the camera cover, the surface of the camera cover is struck to remove the attached natural ocher pigment. The operation was repeated 5 times. Thereafter, a photograph of the hydrophilic film after repeating the work 5 times was taken, and in the range of 10 mm × 10 mm, the adhesion area of the natural ocher pigment was obtained by binarized image analysis using image analysis software ImageFactory (manufactured by Imsoft). The degree of contamination was evaluated according to the following evaluation criteria. Among the evaluation criteria A to E, A and B were allowed.

<Evaluation criteria>
A: The natural ocher pigment does not adhere to the surface of the hydrophilic film and is colorless and transparent.
B: A natural ocher pigment adheres to the surface of the hydrophilic film, and the adhesion area is 10% or less of the total area.
C: A natural ocher pigment adheres to the surface of the hydrophilic film, and the adhesion area exceeds 10% of the total area and is 50% or less.
D: Although natural ocher pigment adheres to the surface of the hydrophilic film and the transparency of the hydrophilic film is maintained, the adhesion area exceeds 50% of the total area.
E: Natural ocher pigment adheres to the entire surface of the hydrophilic film, and part or all of the surface is opaque.

(Examples 2 to 14, Comparative Examples 1 to 4 and Comparative Examples 6 to 7)
In Example 1, a hydrophilic film was prepared in the same manner as in Example 1 except that various components, base materials, and drying conditions were changed as shown in Table 2. Further, a camera cover (laminate) for a surveillance camera was produced in the same manner as in Example 1, and measured and evaluated. The results of measurement and evaluation are shown in Table 2.

(Comparative Example 5)
A hydrophilic film was prepared in the same manner as in Example 1 except that EXCELPURE manufactured by China Automotive Industry Co., Ltd. was used as the coating solution. Further, a camera cover (laminate) for a surveillance camera was produced in the same manner as in Example 1, and measured and evaluated. The results of measurement and evaluation are shown in Table 2.

(Explanation of Table 2)
About silica particles
・ Silica particles 1… Snowtex (registered trademark) O, average primary particle size: 10 nm to 15 nm, manufactured by Nissan Chemical Industries ・ Silica particles 2… Snowtex (registered trademark) OXS, average primary particle size: 4 to 6 nm, Nissan Made by Chemical Industry Co., Ltd./Silica Particle 3 ... Snowtex (registered trademark) OS, average primary particle size: 8 to 11 nm, manufactured by Nissan Chemical Industries Co., Ltd./Silica particle 4 ... Snowtex (registered trademark) N40, average primary particle size: 20 nm ~ 30 nm, manufactured by Nissan Chemical Industries, Ltd., silica particles 5 ... Snowtex (registered trademark) OYL, average primary particle size: 50 nm to 80 nm, manufactured by Nissan Chemical Industries, Ltd.
-Acrylic plate ... Planar shape, plate size: 300 mm x 450 mm, thickness: 1 mm, made by Ebara Kogyo Co., Ltd.-Dome substrate ... Semi-ellipsoidal shape (dome shape), maximum outer diameter: 150 mm, maximum height: 130 mm, thickness: 3mm, polymethylmethacrylate molding member, K camera type made by Sugawara Kogyo Co., Ltd. (transparent)

As shown in Table 2, in the examples, any camera cover for a surveillance camera was colorless and transparent, and exhibited good scratch resistance and hydrophilicity.
In contrast, in Comparative Examples 1 to 7, the surface of the camera cover for the surveillance camera was inferior in both scratch resistance and hydrophilicity.

The disclosure of Japanese Patent Application No. 2015-039450 filed on February 27, 2015 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards mentioned in this specification are to the same extent as if each individual document, patent application, and technical standard were specifically and individually stated to be incorporated by reference, Incorporated herein by reference.

Claims

A hydrophilic film containing a siloxane binder and silica particles, wherein the surface area difference ΔS and the surface roughness Ra on the surface satisfy the relationship of the following formula 1.
ΔS ≦ 0.5Ra Formula 1
In Equation 1, ΔS is a percentage obtained by Equation 2 below.
ΔS = [(S X −S 0 ) / S 0 ] × 100 Equation 2
In Equation 2, S 0 represents the projected area viewed from the perpendicular direction of the hydrophilic film, and S X represents the actual surface area of the surface of the hydrophilic film in the projected area represented by S 0 .
The hydrophilic film according to claim 1, wherein the surface roughness Ra is 100 nm or less.
The hydrophilic film according to claim 1 or 2, wherein the surface roughness Ra is 10 nm or less.
The hydrophilic film according to any one of claims 1 to 3, wherein the surface area difference ΔS is 0.1% or more.
The hydrophilic film according to any one of claims 1 to 4, further comprising an antistatic agent.
The hydrophilic film according to claim 5, wherein at least one of the antistatic agents is an ionic surfactant.
The hydrophilic film according to any one of claims 1 to 6, further comprising a surfactant.
The hydrophilic film according to claim 7, wherein the surfactant is a nonionic surfactant.
The hydrophilic film according to any one of claims 1 to 8, wherein the siloxane binder is a siloxane binder formed from a compound represented by the following general formula (1).

In general formula (1), R 1 , R 2 , R 3 , and R 4 each independently represent a monovalent organic group having 1 to 6 carbon atoms. n represents an integer of 2 to 20.
The hydrophilic membrane according to any one of claims 1 to 9, wherein an average primary particle diameter of the silica particles is 2 nm or more and 100 nm or less.
A coating step of coating a substrate with a coating solution containing a siloxane binder and silica particles having an average primary particle size of 2 nm to 100 nm,
A drying step of drying the coating film coated on the substrate by the coating step at a temperature of 20 ° C. or higher and 150 ° C. or lower;
The ratio of silica particles to siloxane binder is 0.1 to 1.8 on a mass basis, and the surface area difference ΔS on the surface and the surface roughness Ra satisfy the relationship of the following formula 1. A method for producing a hydrophilic film.
ΔS ≦ 0.5Ra Formula 1
In Equation 1, ΔS is a percentage obtained by Equation 2 below.
ΔS = [(S X −S 0 ) / S 0 ] × 100 Equation 2
In Equation 2, S 0 represents the projected area viewed from the perpendicular direction of the hydrophilic film, and S X represents the actual surface area of the surface of the hydrophilic film in the projected area represented by S 0 .
Furthermore, the manufacturing method of the hydrophilic film | membrane of Claim 11 which has the preparation process which prepares the said coating liquid by mixing water, a siloxane oligomer, and a silica particle with an average primary particle diameter of 2 nm or more and 100 nm or less. .
The method for producing a hydrophilic film according to claim 12, wherein the preparation step further comprises preparing a coating solution by mixing a catalyst that promotes the condensation reaction of the siloxane oligomer.
A laminate having a substrate and the hydrophilic film according to any one of claims 1 to 10.
A protective material for a surveillance camera, comprising the laminate according to claim 14.
The protective material for a surveillance camera according to claim 15, wherein the shape of the base material in the laminate is a hemispherical shape, a semi-ellipsoidal shape, a planar shape, a prismatic shape or a cylindrical shape.
The surveillance camera protective material according to claim 15 or 16, which is used for a surveillance camera installed outdoors.
A surveillance camera comprising the surveillance camera protective material according to any one of claims 15 to 17.