JP2003176152A - Cold curing lens and water repellent agent for lens filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water repellent agent which gives strong water repellent and oil repellecy to films and has no influence on optical characteristics by reacting with a lens and a glass substrate of a filter applied to the front surfaces of the lens and lens filter and being dried at ordinary temperature. <P>SOLUTION: The water repellent agent for the lens and the lens filter contains polysilazane and polysiloxazane at a concentration of 0.01 to 10% in a fluorine solvent. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a water repellent which is applied to the surfaces of lenses and lens filters and dried at room temperature to react with the surface of a substrate to form a strong water repellent film.

[0002]

2. Description of the Related Art In photography, various filters are used for the purpose of protecting lenses, blocking ultraviolet rays, adjusting light intensity, converting color temperature, correcting colors and producing special effects. However, lenses and lens filters for general-purpose cameras used outdoors, news still cameras, video cameras, etc. interfere with shooting due to water droplets caused by rainfall, snow, water splashes on the coast, salt damage, dust, etc. It was difficult to easily remove it at the shooting site even if it got scratched or dirt was attached, and it often attacked the coating layer.

[0003]

Conventionally, there has been a water repellent which imparts water repellency to a glass surface such as a window glass in automobiles, ships and the like. As a water repellent for glass, for example, there is a composition (Patent Publication S50-15473) consisting of alkyl polysiloxane and one acid selected from sulfuric acid, phosphoric acid, aromatic sulfonic acid, hydrochloric acid, etc. Cannot be maintained, and since acid is used, there is a risk that the coating film may be attacked or the metal may be attacked, which may interfere with the filter frame or the expensive camera body.

Further, a product in which a water-repellent film is coated on the filter in advance by a vacuum vapor deposition process ["Waterproof coat" manufactured by Marumi Koki Co., Ltd.) (JP 2001-18A).
3504) is also on sale, but there are few varieties and it is not required for the filters on hand that are currently used, so you have to purchase it again, and the water repellent treatment is applied only to the glass surface of the filter, and the metal of the frame is used. However, there were many cases where water droplets accumulated in the frame and interfered with shooting.

The present invention is a treatment agent for forming a water-repellent or oil-repellent film having excellent durability which does not affect optical characteristics by reacting with the surface of a substrate by applying it on the glass surface of lenses and lens filters. Therefore, it is not necessary to purchase a dedicated filter, and the filter currently in use can be easily transformed into a water- and oil-repellent filter.

[0006]

The water-repellent agent of the present invention is a water-repellent agent containing polysilazane or polysiloxazane which cures at room temperature and is used by dissolving it in a fluorine-based solvent.

Polysilazanes or polysiloxazans can be made by known methods, eg US Pat. No. 25646.
As described in Japanese Patent No. 74, etc., it can be easily obtained by reacting a halosilane having a halogen atom bonded to silicon with ammonia or a primary amine in a solvent. In the case of polysiloxazane, the organopolysiloxane contains at least 2 SiX per block.
It can be synthesized by adding a halosiloxane containing a group and reacting it with ammonia or a primary amine.

The diluting solvent is a good solvent for the water repellent,
A fluorocarbon solvent is used which does not attack the coating agent and the substrate applied to the lens and the lens filter, has a weak odor, and does not fall under various legal regulations, that is, a CFC solvent. Examples of CFC solvents include dichlorofluoroethane such as HCFC141
b, HCFC-225, hydrofluorocarbons such as HFC-365mf and hydrofluoroethers such as HFE-7100 are used, and these may be used alone or in combination.

The coating can be performed by a method such as degreasing and washing, dipping on the surface of the dried substrate, brush coating, cloth coating, spray coating and the like.

[Effects of the Invention] A commercially available UV filter [MC UV filter manufactured by Kenko Co., Ltd.] is cleaned of dirt and dust with a lens cleaner and dried, and then a small amount of the water repellent of the present invention is added to the cloth to form a glass for the filter. Apply it on the surface, lightly wipe it with another cloth, and dry it at room temperature. Also, by applying to the metal part of the filter frame, a very thin water and oil repellent film is formed on the surface and frame of the filter.
Even when shooting in the rain, water drops on the surface of the filter dropped without stopping, and the optical characteristics were not affected, so there was no problem in shooting. As can be seen from the evaluation results, it shows a good contact angle.

[0010]

Synthesis Example 1 Methyltrichlorosilane (CH ₃ SiCl
₃ ) 20 g of methylene chloride was dissolved in 200 ml of methylene chloride, cooled to 5 ° C. or lower, and ammonia gas was blown into the mixture, followed by stirring for 2 hours, and then the temperature was raised to drive off excess ammonia, followed by cooling to produce ammonium chloride. Was filtered to obtain a polysilazane solution. The methylene chloride was removed from the filtrate by evaporation and 16 g of white solid was obtained.

[0011]

[Synthesis Example 2] Methyltrichlorosilane and formula A mixture with 40 mol of organochlorosiloxane represented by was dissolved in 150 ml of methylene chloride, and polysiloxazane was synthesized in the same manner as in Synthesis Example 1.

[0012]

Example 1 A color-enhanced filter "Green Enrinser" [manufactured by Kenko Co., Ltd.] that had been degreased, washed and dried
10 g of polysilazane synthesized in Synthesis Example 1 was mixed with hydrofluoroether [HFE-710 manufactured by Sumitomo 3M Limited].
0] A water repellent prepared by adding 1 kg was mixed in a small amount in a cloth, applied to the surface of the filter, and wiped up with another cloth. The treated film had excellent water repellency and antifouling properties, and even if water drops were applied, it did not stay on the filter surface and fell. In addition, dust can be removed easily at the shooting site by wiping it gently with a cloth.

[0013]

[Example 2] 1 kg of dichlorofluoroethane [HCFC-141b manufactured by Daikin Industries, Ltd.] was added to 5 g of polysiloxazane synthesized in Synthesis Example 2 on a degreased and washed Skylight filter MC1B [manufactured by Kenko Corporation]. In addition, the prepared water repellent was spray coated and dried at room temperature.
The treated film has excellent water repellency and antifouling properties, and even if water drops are applied, it drops without staying on the filter surface, and it is possible to shoot without affecting the optical characteristics. In addition, dust can be removed easily at the shooting site by wiping it gently with a cloth.

[0014]

[Example 3] A close-up lens [manufactured by Marumi Koki Co., Ltd.] that had been degreased, washed and dried, and 5 g of polysiloxazane synthesized in Synthesis Example 2 and hydrofluorocarbon [AK-225 manufactured by Asahi Glass Co., Ltd.] A water repellent prepared by adding 1 kg was mixed in a cloth and applied, and the cloth was lightly wiped with another cloth and dried at room temperature. The treated film was excellent in water repellency, and it was possible to shoot smoothly without water droplets remaining on the filter even in wind and rain.

[0015]

Example 4 A cloth containing a water repellent prepared by adding 700 g of dichlorofluorocarbon and 300 g of hydrofluoroether to 2 g of polysilazane synthesized in Synthesis Example 1 was added to a degreased and washed PL filter [manufactured by Kenko Co., Ltd.]. It was applied, wiped lightly with another cloth, and dried at room temperature. The treated film was excellent in water repellency, water droplets did not collect on the filter surface, and shooting was possible without affecting the optical characteristics.

[0016]

【Evaluation results】

(Contact angle of water): 5 ml of water was dropped on a filter kept horizontally, and Contact meter C
The contact angle was measured using AA [Kyowa Scientific Co., Ltd.]. (Hexadecane contact angle): 5 ml of n-hexadecane was dropped on a filter kept horizontally, and the contact angle was measured using the same measuring device as above. (Anti-fouling property): Set the filter in the sunshine weather meter (manufactured by Suga Test Instruments) at an angle of 45 degrees to 100.
After exposure for a period of time, the appearance was observed.

Claims (2)

[Claims] 1. A room temperature-curable water repellent comprising polysilazane and polysiloxazane, which is firmly adhered to a lens and a lens filter when applied. 2. A room temperature curable water repellent obtained by dissolving polysilazane and polysiloxazane in a flon solvent at a concentration of 0.01 to 10%.