JP2748413B2 - Low reflection processing agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention reduces the surface reflection of a substrate, such as glass or transparent plastic, by treating the surface of the substrate, thereby improving visibility. The present invention relates to a low-reflection processing agent useful for effectively utilizing visible light energy.

[Prior Art] Transparent materials such as glass or transparent plastic are indispensable for windows, doors, show windows, show cases, optical lenses, spectacle lenses, sunglasses, etc. of buildings and vehicles. However, the surface of such a transparent material has a drawback in that the transparency and transparency inherent to the material are impaired due to glare and glare caused by reflection of sunlight and illumination light, or the surrounding scenery is reflected. In addition, in the use of sunlight, for example, a solar water heater needs to remove or reduce the reflection loss of a transparent material used for a heat collecting part in order to improve a heat collecting effect, and pass a large amount of energy. is there.

Hitherto, development of antireflection on the surface of a transparent substrate such as glass or transparent plastic has been promoted mainly for optical components. For example, to prevent reflection of visible light on the glass surface
Single-layer film made of MgF ₂ , cryolite, etc.
A single-layer film made of O, CeO ₂ , ZnS, etc .; a multi-layer film made of SiO-MgF ₂ , arsenic trisulfide glass-WO _2- cryolite; and a monolayer film made of SiO ₂ , LiF, etc. for ultraviolet. A layer film is formed as an antireflection film by a vacuum evaporation method or a sputtering method, and has been put to practical use in optical lenses, eyeglass lenses, filters, and the like. Recently, these antireflection film forming methods have been applied to heat ray reflective glass in sheet glass.

On the other hand, a low-reflection treatment agent composed of a polymer substance is applied to the surface of a transparent substrate such as glass or transparent plastic, sprayed, or dipped in the treatment agent to form a low-reflection coating film. Reflection treatment agents or treatment methods have been proposed.

However, the above-mentioned vacuum deposition method or sputtering method is limited to relatively small precision optical parts in view of the mechanism of the apparatus and cost, and is not suitable for continuous production. Apply and spray a coating of low reflection treatment agent,
Alternatively, in the method of forming by a method such as immersion, the adhesive strength between the transparent substrate and the low-reflection treatment agent is weak, and there is a problem in the durability of the formed low-reflection treatment agent. It is easily contaminated, is damaged by washing work for contamination, and has a defect in hardness and durability such as easy peeling.

[Problems to be Solved by the Invention] An object of the present invention is to provide a transparent base such as glass or transparent plastic without impairing the transparency and transparency thereof, based on the recognition of the above-mentioned problems of the conventional technology. The present invention provides a low-reflection processing agent having good durability, which makes the surface of the substrate low-reflective by a known method such as coating, spraying, or dipping on the surface of the substrate, and whose performance can be maintained for a long time. It is intended to do so.

[Means for Solving the Problems] As a result of intensive studies based on the above-mentioned objects, the present inventors have found that a polymer having a fluorinated aliphatic ring structure has high transparency and a low refractive index, and The inventors have newly found that they are useful as a low-reflection processing agent excellent in film formability on a substrate surface.

Thus, the present invention has been completed on the basis of the above findings, and is characterized in that the low-reflection processing agent for treating the surface of a transparent substrate is made of a polymer having a fluorinated aliphatic ring structure in the main chain. Another object of the present invention is to provide a glass or transparent plastic product having a low-reflection processing agent and an antireflection film made of a polymer having a fluorinated aliphatic ring structure in the main chain on the surface of a transparent substrate.

In the present invention, the polymer having a fluorinated aliphatic ring structure in the main chain can be exemplified in a wide range including conventionally known or well-known polymers.

And those having a ring structure such as Of these,
A polymer having the following ring structure is typical. However, the content of the present invention is not limited only to these.

The methods for producing these polymers are as follows. However, it is not limited to these production methods.

1.By cyclopolymerization 2. Using cyclic monomers (USP 3978030) In the above, a polymer having a perfluoroaliphatic ring structure is exemplified, but in the present invention, a polymer in which part of the above-described fluorine atoms is substituted with another hydrogen atom or an organic group,
Or obtained by metathesis polymerization And the like having a ring structure such as

Thus, the polymer having a specific ring structure in the present invention can be smoothly and advantageously obtained by the cyclization polymerization as described above. In particular, the polymer having two polymerizable groups having different polymerizabilities in the molecule and having these two polymerizable groups. By using a monomer in which the number of atoms in the linear portion of the linking chain connecting two polymerizable groups is 2 to 7, it is possible to suppress the by-product of gelation without employing ultrahigh pressure conditions or large dilution conditions. Cyclization polymerization can proceed smoothly and advantageously.

First, as a monomer suitable for the above-mentioned cyclization polymerization, it is desirable to have two carbon-carbon multiple bonds having different polymerizabilities. Usually, a carbon-carbon double bond is employed, and two multiple bonds having different types or structures are employed. For example, fluorine-containing monomers having two multiple bonds that are not bilaterally symmetric, vinyl and allyl groups, vinyl ether and vinyl groups, fluorine-containing multiple bonds and hydrocarbon multiple bonds, perfluoro multiple bonds and partially fluorinated multiple bonds And the like. Second, the number of atoms in the linear portion of the connecting chain connecting these two carbon-carbon multiple bonds is 2-7.
It is desirable that The number of atoms in the linear portion of the connecting chain is 0
In the case of 1 to 1, cyclization polymerization hardly occurs, and the same applies to the case of 8 or more. Usually preferably, the number of atoms is 2 to 5. Further, the connecting chain is not limited to a straight chain, and may have a side chain structure or a ring structure, and the constituent atoms are not limited to carbon atoms, and may include hetero atoms such as O, S, and N. good. Third, those having a fluorine content of 10% by weight or more are desirable. If the fluorine content is too low, the specificity of the fluorine atom is hardly exhibited. As a matter of course, perfluoro monomers are preferably employed.

Specific examples of the above specific fluorine-containing monomer include CF ₂ = CFOCF ₂ CF = CF ₂ , CF ₂ = CFOCF ₂ CF ₂ CF = CF ₂ , CF ₂ = CFOCF ₂ CF = CH ₂ , CF ₂ = CFOCF ₂ OCF ₂ CF = CF ₂ , CF ₂ = CFOCF ₂ CF ₂ CH = CH ₂ , And the like. In the present invention, those having one vinyl ether group of CF ₂ CCFO— are preferably employed in terms of polymerization reactivity, cyclopolymerization, suppression of gelation, etc., and in particular, perfluoroallyl vinyl ether (CF ₂ CCFOCF ₂₎ CF
= CF ₂ ) and perfluorobutenyl vinyl ether (CF ₂
= CFOCF ₂ CF ₂ CF = CF ₂ ) is a preferred example.

The monomer components as described above can be used alone or in combination of two or more types.Furthermore, there is no problem even if copolymerization is carried out in combination with other copolymerization components to such an extent that the essence of these components is not impaired. If necessary, the polymer may be cross-linked by any method.

The other monomer to be copolymerized is not particularly limited as long as it is a monomer having radical polymerizability, and a wide range of fluorine-containing, hydrocarbon-based, and the like can be exemplified. Naturally, these other monomers may be used alone to form a radical copolymer with the monomer capable of introducing the specific ring structure, or the above copolymerization reaction may be carried out by using two or more kinds in combination. May be performed. In the present invention, it is usually desirable to select a fluorinated monomer such as fluoroolefin or fluorovinyl ether as the other monomer. For example, tetrafluoroethylene,
Perfluoromethyl vinyl ether, perfluoropropyl vinyl ether, or perfluorovinyl ether containing a functional group such as a carboxylic acid group or a sulfonic acid group are preferred specific examples, such as vinylidene fluoride, vinyl fluoride, and chlorotrifluoroethylene. May also be exemplified.

As the copolymer composition, the composition of the cyclic structure is preferably at least 20%, more preferably 40%, in order to make use of the characteristics of the specific fluorinated aliphatic ring structure aimed at in the present invention.
% Is desirable, but the low-reflection processing agent is appropriately selected depending on the relationship between the refractive index of the coating film to be formed and the adhesiveness.

Since the polymer having a specific ring structure in the present invention is soluble in a fluorine-based solvent or the like, a solution can be used as a treatment form for the transparent substrate.

The solvent to be used is not limited as long as it dissolves the above polymer, but is not limited to perfluorobenzene, "Aflud" (trade name: a fluorine-based solvent manufactured by Asahi Glass Co., Ltd.),
"Fluorinert" (trade name: Perfluoro (2M manufactured by 3M)
-Butyltetrahydrofuran), trichlorotrifluoroethane and the like. As a matter of course, two or more of them can be used in combination as a solvent. In particular, in the case of a mixed solvent, hydrocarbons, chlorinated hydrocarbons, fluorinated hydrocarbons, alcohols, and other organic solvents can be used in combination. The solution concentration is 0.01 wt% to 50 wt%, preferably 0.1 wt% to 20 wt%.

The method for treating the transparent substrate is not particularly limited, and the transparent substrate is applied by usual brushing, roll coating, spraying, dipping, spin casting, or the like.

The low-reflection processing agent of the present invention can obtain a film having adhesiveness that can withstand practical use by directly treating on a transparent substrate such as glass or transparent plastic, but depending on the type of the transparent substrate, the adhesiveness is poor or Alternatively, in order to further strengthen the adhesion, a treatment can be performed on a coating film which has been previously formed on a transparent substrate with a primer such as a silane coupling agent. Further, it is also possible to further improve the adhesiveness by copolymerizing a monolayer having an adhesive group.

In forming an anti-reflection film on the surface of a transparent substrate using the low-reflection processing agent of the present invention, a sufficient anti-reflection effect can be obtained even if a single layer of a fluoropolymer coating film having a low refractive index is formed on the substrate. However, it is also possible to provide a coating film having a higher refractive index than that of the fluoropolymer between the substrate and the fluoropolymer layer to form a multilayer, thereby enhancing the antireflection performance.

The coating formed by the low-reflection processing agent of the present invention itself has practical strength, but can be cured by a cross-linking reaction when a very thin film or scratch resistance is required.

As a method for crosslinking the fluoropolymer used in the low-reflection processing agent of the present invention, an ordinary method or the like can be appropriately used. For example, it is possible to crosslink by copolymerizing a monomer having a crosslinkable site, to add a crosslinking agent to crosslink, or to crosslink using radiation or the like.

The low-reflection processing agent of the present invention is suitably used not only for glass but also for transparent plastics such as polyvinyl chloride, polymethyl methacrylate, polycarbonate, polydiethylene glycol bisallyl carbonate, polystyrene, and unsaturated polyester. Building windows, doors, show windows, showcases, vehicle windows and windshields, optical lenses, spectacle lenses, safety glasses, filters, television display anti-glare, clock glass, sunlight collection It can be used for components, other glass or transparent plastic products.

[Action] In the present invention, the polymer having a fluorinated aliphatic ring structure in the main chain exhibits high transparency and high transparency despite being a fluororesin because of low crystallinity or little crystallinity. It shows light transmittance and is considered to have a lower refractive index and better moisture resistance, weather resistance, and chemical resistance than ordinary hydrocarbon-based resins because it is a fluoropolymer. However, such description is intended to help the understanding of the present invention, and is not intended to limit the present invention.

[Example] Next, an example of the present invention will be described more specifically. However, it goes without saying that this description does not limit the present invention.

Synthesis Example 1 35 g of perfluoroallyl vinyl ether, 5 g of trichlorotrifluoroethane (hereinafter abbreviated as R-113),
150 g of ion-exchanged water and as a polymerization initiator Was placed in a pressure-resistant glass autoclave having an internal volume of 200 ml. After purging the system with nitrogen three times, suspension polymerization was performed at 26 ° C. for 23 hours. As a result, 28 g of a polymer was obtained.

When the infrared absorption spectrum of this polymer was measured, the result was 1660 cm ⁻¹ , 184
There was no absorption around 0 cm ^-1 . Further, when this polymer was dissolved in perfluorobenzene and the ¹⁹ F NMR spectrum was measured, a spectrum showing the following repeating structure was obtained.

The intrinsic viscosity [η] of this polymer is "Fluorinert" FC
It was 0.530 at-30 ° C in -75 (trade name: liquid containing perfluoro (2-butyltetrahydrofuran) manufactured by 3M Company as a main component, hereinafter abbreviated as FC-75). The glass transition point of the polymer is 69 ° C., and it is a tough and transparent glassy polymer at room temperature. The 10% thermal decomposition temperature is 462 ° C., and the polymer is colorless and transparent, and has a low refractive index of 1.34,
The light transmittance was as high as 95%.

Synthetic Example 2 1,1,2,4,4,5,5-heptafluoro-3-oxa-1,6-
20 g of heptadiene and 40 g of R-113 were placed in a three-necked flask purged with nitrogen, and used as a polymerization initiator. 20 mg was added, and the inside of the system was further replaced with nitrogen.
Polymerized for 10 hours. As a result, 10 g of a polymer was obtained. This polymer is a polymer soluble in R-113 and has an intrinsic viscosity [η] at 30 ° C. of 0.96 in meta-xylene hexafluoride.
Met. ¹⁹ F NMR and ¹ H NMR confirmed that the polymer had a cyclic structure in the main chain.

This polymer was colorless and transparent, had a low refractive index of 1.36, and had a high light transmittance of 93%.

Example 1 The fluoropolymer obtained in Synthesis Example 1 was dissolved in "Fluorinert" FC-75, and a 1 wt% solution was prepared to obtain a low reflection processing agent. 10 cm x 10 cm (2 mm thick) glass plate (soda lime glass) and polydiethylene glycol bisallyl carbonate plate (hereinafter referred to as carbonate plate)
Was immersed in a low-reflection processing agent, pulled up at a speed of 20 cm / min, and dried overnight at a temperature of 60 ° C. to form a coating film. The thickness of each of the formed films was 0.095 μm. The total light transmittance of these plates was measured with Asahi Optical's MODEL304, and the average reflectance of the coating film was measured using a Hitachi Spectrophotometer regular reflection light measurement accessory type 323 with a wavelength of 400 to 700 nm. Table 1 shows the results measured at an incident angle of 5 °.

Example 2 3-glycidoxypropyltrimethoxysilane 5.0
And 4.8 parts of methyltrimethoxysilane, 1.1 parts of ethyltriethoxysilane and 283.2 parts of diacetone alcohol to obtain a uniform solution, and the mixture was maintained at a temperature of 5 ° C. under ice cooling. Next, 3.4 parts of a 1% aqueous hydrochloric acid solution was gradually added dropwise to this solution, and after completion of the addition, the mixture was returned to room temperature and left to stand for 24 hours to mature. Further, 15.7 parts of methanol-dispersed colloidal antimony, 0.6 part of a bisphenol A type epoxy resin (EP828 manufactured by Yuka Shell Co., Ltd.), 0.1 part of aluminum acetylacetonate, and 0.4 part of a silicone surfactant were added to the obtained solution. After aging for days, the mixture was filtered to obtain a coating composition.

The same glass plate and carbonate plate as in Example 1 were immersed in this coating composition, pulled up at a speed of 9 cm / min, and fired at 100 ° C. for 10 minutes. Further, a coating film of a low reflection processing agent was formed thereon in the same manner as in Example 1, and the total light transmittance and the average reflectance were measured. Table 2 shows the results.

Example 3 3-glycidoxypropyltrimethoxysilane 5.0
, 2.4 parts of methyltrimethoxysilane and 561.4 parts of diacetone alcohol to obtain a uniform solution, which was then maintained at a temperature of ice cooling (5 ° C). Next, 2.1 parts of a 1% aqueous hydrochloric acid solution was gradually added dropwise to this solution, and after completion of the addition,
The mixture was returned to room temperature and left for one day to mature. Further, 47.2 parts of colloidal antimony dispersed in methanol and bisphenol A type epoxy resin (EP 828 manufactured by Yuka Shell Co., Ltd.) were added to the obtained solution.
0.5 parts, 0.2 parts of aluminum acetylacetonate and 0.4 parts of a silicone-based surfactant were added, the mixture was aged for 3 days, and then filtered to obtain a coating composition.

The same glass plate and carbonate plate as in Example 1 were immersed in this coating composition, pulled up at a speed of 9 cm / min, and fired at 100 ° C. for 10 minutes. Further, a coating film of a low reflection processing agent was formed thereon in the same manner as in Example 1, and the total light transmittance and the average reflectance were measured. Table 3 shows the results.

[Effect of the Invention] In the present invention, a polymer having a fluorinated aliphatic ring structure in the main chain is employed as a low-reflection processing agent, whereby a film having a low refractive index can be formed on the surface of a transparent molded article, and the transparent molded article It is possible to significantly reduce the light reflectance of the body.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G02B 1/11 G02B 1/10 A

Claims (3)

(57) [Claims] 1. A low-reflection processing agent characterized in that the low-reflection processing agent for treating the surface of a transparent substrate comprises a polymer having a fluorinated aliphatic ring structure in its main chain. 2. A glass or transparent plastic product having an antireflection film made of a polymer having a fluorinated alicyclic structure in its main chain on the surface of a transparent substrate. 3. The method according to claim 1, wherein the surface of the transparent substrate and an antireflection film made of a polymer having a fluorinated aliphatic ring structure in its main chain,
3. The glass or transparent plastic product according to claim 2, further comprising a coating layer having a higher refractive index than the antireflection film.