JPH0987402A - Water-repellent resin molding and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a cellulosic resin molding hardly attaching water drop, ice or dirt. SOLUTION: (Heptadecafluoro-1, 1, 2, 2-tetrahydrodesyl)trichlorosilane in an amount of 0.5ml is added to 50ml perfluoropentane and a cellulose acetate resin plate is immersed in the mixed solution and allowed to stand at ambient temperature and the cellulose acetate resin plate is taken out and cleaned with perfluoropentane and dried to provide the objective water-repelling cellulose acetate resin plate formed with a film 12 to which a fluoroalkyl group formed from a silane compound is fixed through a covalent bond (Si-O bond) on the surface of the plate 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cellulosic resin molded product to which dirt, water drops, and ice hardly adhere, and a method for producing the same.

Further, the present invention relates to a goggle, a helmet visor, a spectacle frame, a spectacle lens, sunglasses, or a plate-shaped resin molded product to which they are applied, for use in a vehicle window.

[0003]

2. Description of the Related Art Conventionally, a glass plate has been mainly used as a base material such as a house window or an automobile window which is required to be transparent.

On the other hand, for safety reasons, a cellulosic resin molding having transparency and excellent impact resistance is used for ski goggles and motorcycle helmets.
For safety and weight reduction, a plate of cellulose-based resin or acrylic resin having excellent impact resistance and transparency is used for glasses and sunglasses, aircraft windows, and ship windows.

[0005] In these applications, there is a problem that visibility is deteriorated due to clouding due to condensation of water vapor, but it is used by making the surface of the resin plate hydrophilic so that it is hard to cloud. Is the current situation. Examples of the surface treatment method include a method of treating a cellulose-based resin molded product with an alkali to hydrolyze it, and a method of exposing the cellulose-based resin molded product to oxygen plasma or steam plasma.

[0006]

The surface of the resin plate made hydrophilic is less likely to fog, but water droplets tend to adhere, and the outside air side of the resin plate is
When exposed to rain or snow, there is a problem that water drops or ice adhere to the eyes and the visibility deteriorates.

Further, dirt is apt to adhere, and the visibility is deteriorated unless it is regularly washed. Therefore, it has been desired to make necessary parts water-repellent without impairing the transparency of the resin plate.

The present invention is intended to solve the above-mentioned conventional problems, and an object thereof is to provide a cellulosic resin molded product which is less likely to have water drops, ice and dirt attached thereto, and a method for producing the same. Only one surface such as the outside air side is water repellent and the original transparency of the resin is not impaired, or part of the surface is water repellent and the original transparency of the resin is not impaired on the same surface of the resin plate. It is an object of the present invention to provide a water repellent cellulosic resin molded article and a method for producing the same.

Of course, according to the present invention, the resin molded product is not only water repellent on one side, but water repellent resin molded product in which only the desired part is made water repellent and the remaining part is made hydrophilic. Can also be provided.

[0010]

In order to achieve the above object, a water-repellent resin molding of the present invention, at least a part of the surface of which is water-repellent, has an alkyl group on at least a part of the surface of a cellulose resin molding. Alternatively, the fluoroalkyl group is fixed by a covalent bond.

In the above-mentioned constitution, an alkyl group or a fluoroalkyl group is covalently fixed to a part of the surface of the cellulosic resin molded article, and the remaining surface has a hydroxyl group, so that the cellulosic resin molded article is formed. It is preferable that a part of the surface of is water repellent and the remaining surface is hydrophilic.

In the above construction, the cellulose resin is any one of cellulose acetate, cellulose propionate, cellulose butyrate and regenerated cellulose, or a mixture thereof or 30% by weight thereof.
A resin mixture containing the above is preferable.

In the above structure, the covalent bond is Si.
It is preferably an -O bond. Moreover, in the said structure, it is preferable that a cellulose resin molding is a transparent cellulose resin molding.

The one-sided hydrophilic one-sided water-repellent plate-shaped resin molded product of the present invention is a cellulose-based resin molded product in goggles,
A resin plate used for helmet visor, spectacle lens, sunglasses, or vehicle window, wherein one surface of the cellulose resin plate has a hydroxyl group, and the other surface has an alkyl group or a fluoroalkyl group fixed by covalent bond. It is characterized by being.

Further, the method for producing a water-repellent resin molded product according to the present invention in which at least a part of the surface is water-repellent comprises an alkoxy group,
At least one selected from an acetoxy group, an isocyanate group, and a halogen is bonded to a silicon atom, and a step of bringing a silane compound having an alkyl group or a fluoroalkyl group into contact with at least a part of the surface of the cellulosic resin molded article is included. Is characterized by.

In the method for producing a resin molded product, the cellulose resin molded product, which is a raw material resin molded product, is
It is preferably a cellulose-based resin molded product whose surface is hydrolyzed.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The cellulose resin used in the present invention is any one of cellulose acetate, cellulose propionate, cellulose butyrate, regenerated cellulose, a mixture thereof, or a mixture thereof.
Examples thereof include a resin mixture containing 0% by weight or more. In the case of a resin mixture containing 30% by weight or more of a cellulosic resin, the other resin to be mixed is preferably a material relatively compatible with the cellulosic resin, and examples thereof include an acrylic resin and polycarbonate.

All of them can be similarly subjected to a water-repellent treatment. Of these, cellulose acetate is the most excellent from the viewpoint of price and processability. Therefore, in the following examples, cellulose acetate is used as the cellulose resin. I showed an example.

In the water repellent treatment, a silane compound is brought into contact with a cellulosic resin molded product. By this treatment, a hydroxyl group of cellulose and a silane compound react with each other and the silane compound is bonded onto the cellulose through a Si--O bond. And exhibits water repellency. In order to perform this treatment, active hydrogen groups such as hydroxyl groups and imino groups (N—H) are required on the surface of the cellulose resin molded product.

Cellulose acetate having a degree of acetylation (acetic acid content) of 62% to 43% is commercially available. Most of the hydroxyl groups of cellulose are acetic acid esters with an acetylation degree of 62%, but the surface is somewhat hydrolyzed by the moisture in the air, and even if the acetylation degree is 62%. Water repellent treatment can be applied. Therefore, if the degree of acetylation is lower than this, water repellent treatment can be performed without any problem.

However, in order to enhance the water repellency, it is preferable to actively hydrolyze the surface to increase the number of hydroxyl groups. As this method, for example, there is a method of immersing a cellulose resin molded product in an alkaline aqueous solution and heating it.
As another method, the number of hydroxyl groups on the surface can be increased by dry treatment such as oxygen plasma treatment or steam plasma treatment.

In this hydrolysis treatment, in order to make the surface of the cellulosic resin molded article hydrophilic, the inside surface of windows, glasses, etc. is treated to be hydrophilic by leaving the hydrophilic treatment surface as it is. It is preferable because it can also serve as anti-fog processing for the surface. If the entire surface is made hydrophilic by this hydrolysis treatment and then only the necessary part, such as the outside air side, is subjected to water repellent treatment, the water repellent treated portion, for example, the outside air side, will be covered with dirt and water droplets. It is possible to manufacture windows and glasses that are difficult and cloudy.

Further, a part of the surface of the resin molded product on the same side is treated to be water-repellent and the remaining part is left as the hydrophilic treated surface. Since it has good adhesiveness with, it is extremely effective when something is to be processed on this part to bond another object. For example, in the goggles and the like, most of the outside air is treated to be water-repellent, and if you leave the part to which you want to attach rubber etc. on the hydrophilic side, you can easily apply rubber etc. to the hydrophilic side. The goggles can be firmly manufactured and can be favorably manufactured. Of course, this is not limited to goggles. In order to leave a part of the same surface as the hydrophilic surface, there is no particular limitation, but the part to be left is appropriately masked (for example, masking with a plastic adhesive tape) and water repellent is applied. The method of is mentioned.

Also, in some cases, when a part of the surface is treated to be water-repellent and the remaining part is left as it is as the original cellulose resin surface, the remaining part is more adhesive than the water-repellent part. Since it is large, it can be adopted for almost the same purpose.

In the water repellent treatment, the silane compound having at least an alkyl group or a fluoroalkyl group and a functional group in which at least one selected from an alkoxy group, an acetoxy group, an isocyanate group and a halogen is bonded to a silicon atom is used as the cellulose. It can be performed by contacting the resin-based molded product.

In particular, when a silane compound having a fluoroalkyl group is used, not only water repellency but also oil repellency can be imparted to the resin molded product. As the alkyl group,
An alkyl group having 2 to 30 carbon atoms is preferable.

The fluoroalkyl group is preferably one in which all or part of the hydrogen atoms in the alkyl group having 3 to 12 carbon atoms is replaced with fluorine. The alkoxy group, 1 to 3 carbon atoms, specifically, methoxy group (CH ₃ O-), ethoxy (CH ₃ CH ₂ O-), propoxy _{(CH 3 CH 2 CH 2 O-} ) is Needless to say, examples thereof are not limited to these.

Examples of the silane compound having an alkyl group include ethyltrichlorosilane, propyltrichlorosilane, octadecyltrichlorosilane, octadecyltriethoxysilane, octadecyltriacetoxysilane, octadecyltriisocyanatesilane and the like.

Examples of the silane compound having a fluoroalkyl group include (3,3,3-trifluoropropyl) trimethoxysilane, (3,3,3-trifluoropropyl) trichlorosilane and (tridecafluoro). -1,1,2,2-
Tetrahydrooctyl) triethoxysilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) triethoxysilane, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trichlorosilane, (henicosafluoro-1 , 1,
2,2-tetrahydrododecyl) trichlorosilane and the like.

When the silane compound is brought into contact with the cellulose resin molding, an alkoxy group, an acetoxy group,
An elimination reaction of an isocyanate group or a halogen occurs, and S is generated between the silane compound and the cellulosic resin molded product.
An i-O bond is formed and the silane compound is fixed to the cellulosic resin molded product.

The method of bringing the silane compound into contact with the cellulosic resin molding includes a vapor phase method and a liquid phase method. The vapor phase method is
A silane compound is introduced in a gaseous state into a dry atmosphere containing a cellulose resin molded product, and the mixture is allowed to stand for a certain period of time while being heated if necessary. This method is (3,3,3-
It is suitable when using a silane compound having a high vapor pressure such as trifluoropropyl) trichlorosilane.

As a method for converting the silane compound into a gas state, for example, when a silane compound having a high vapor pressure is used, a method of putting a liquid or solid silane compound in a closed container can be used. At this time, the airtight container is filled with the silane compound which is naturally vaporized.

In the liquid phase method, the cellulosic resin molded product is dipped in a liquid material consisting of a silane compound alone or a solution of the silane compound diluted with an appropriate solvent, and the reaction is continued for a certain period of time while heating if necessary, followed by washing. The method of doing is available.

In the liquid phase method, a liquid material containing only a silane compound can be used, but it is more economically preferable to dilute it with a suitable solvent. Any solvent may be used as the solvent as long as it dissolves the silane compound, does not react with the silane compound, and does not dissolve the cellulose resin. Examples of such a solvent include hexadecane and perfluoropentane.

The thinner the concentration is, the more economical it is, and the cleaning after the treatment can be completed in a short time. However, if it is too thin, the treatment takes a long time, so 0.5 to 5% by weight is preferable. The reaction temperature and the reaction time are appropriately set depending on the silane compound used, the solvent, and the concentration.

The reaction time is, for example, (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trichlorosilane, in which a compound in which a halogen is bonded to a silicon atom is highly reactive, and a gas phase method, In both the liquid phase method, a sufficient density is obtained at room temperature (25 ° C.) for about 10 minutes to 1 hour.

Further, a compound having an alkoxy group bonded to a silicon atom such as (tridecafluoro-1,1,2,2-tetrahydrooctyl) triethoxysilane has a low reactivity, and a gas phase method or a liquid phase method is used. Both methods are at room temperature (25 ° C) for 1 hour to 2
It takes about 4 hours. However, even when these compounds are used, the reaction time can be shortened by heating. For example, at 80 ° C., the reaction is completed within 10 minutes to 1 hour.

Further, in the case of a compound having an acetoxy group or an isocyanate group, the reaction time is intermediate between these because of the intermediate reactivity between the compound having a halogen and the compound having an alkoxy group.

If a large amount of unreacted silane compound remains on the cellulosic resin molded product after the reaction and impairs transparency, the unreacted excess silane compound must be removed. Of course, when the amount of unreacted silane compound attached is small and transparency is not impaired, it is not necessary to remove the unreacted substance.

The simplest method for removing the unreacted substances is to immerse the post-reaction cellulose resin molded product in a solvent capable of dissolving the silane compound.
Of course, it is not limited to this. As another removal method, for example, there is a method in which the cellulose-based resin molded product after the reaction is placed under reduced pressure and the unreacted product is evaporated.

The solvent used for removing the unreacted matter may be any solvent which dissolves the silane compound and does not dissolve the cellulose resin. For example, perfluoropentane, ethanol and the like can be preferably used, but it goes without saying that they are not limited to these.

When the plate-shaped molded product of the present invention is applied to goggles, helmet visors, spectacle lenses, sunglasses, or vehicle windows, the outside air side is treated mainly with water repellent treatment and the opposite side is treated with hydrophilic treatment. By placing them, water drops, ice, and dirt are less likely to adhere to the surface on the outside air side, and the opposite surface is less likely to be fogged, which is effective in maintaining good visibility. Further, when water repellent treatment is applied to a spectacle frame or the like, it is preferable that the water repellent treatment is applied to all the surfaces so that a spectacle frame that is hard to get dirty can be obtained.

As described above, with the water repellent treatment of the present invention, the contact angle of water on the water repellent treated portion of the surface of the resin molded article becomes 90 degrees or more, and the water droplets adhering to the surface easily fall due to the action of gravity or wind force. Further, the ice adhering to the surface can be easily removed by the force of wind force or a wiper.

Further, due to the water repellency of the surface, stains are hard to attach, and even if stains are attached, they can be easily removed by simply wiping with a cloth or the like. Furthermore, if the alkyl group and the fluoroalkyl group are chemically bonded to the surface of the resin molded product by Si—O bonds, they are easily bonded to the cellulosic resin molded product by a covalent bond, so that they are easily peeled off. The water repellency continues for a long time.

In particular, the resin molded product coated with the fluoroalkyl group has not only water repellency but also oil repellency, and therefore has further excellent antifouling property.

[0046]

EXAMPLES The present invention will be described in more detail below with reference to examples. However, the present invention is not limited to the following specific examples.

Example 1 Perfluoropentane 50 m
0.5 ml of (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trichlorosilane was added to 1, and a cellulose acetate resin plate (10 cm × 10
cm) was soaked and allowed to stand at room temperature for 30 minutes.

Take out the cellulose acetate resin plate,
It was washed by shaking several times in 50 ml of perfluoropentane and then dried. Crushed scraped off the surface of the cellulose acetate resin plate was measured for infrared absorption spectrum in KBr pellet method, 1360 cm ^-1 vicinity (attributable C-
F), around 1320 cm ^-1 (attribution C-F), 1060c
Absorption was observed in the vicinity of m ⁻¹ (assigned Si—O), and it was confirmed that the silane compound was bonded and fixed on the cellulose acetate resin plate as shown in FIG.

FIG. 1 is a schematic sectional view of the vicinity of the surface of a cellulose acetate resin plate, 11 is a cellulose acetate resin plate, and 12 is a coating film made of a silane compound.
Figure X is _{a, C 8 F 17 C 2 H} 4 - represents a.

The contact angle of the cellulose acetate resin plate with water is 70 ° before the treatment and 100 ° after the treatment.
Water repellency was imparted. Further, the contact angle of the cellulose acetate resin plate to the salad oil was 20 ° before the treatment and 70 ° after the treatment, and the oil repellency was imparted.

The transparency of the cellulose acetate plate did not change before and after the treatment. (Example 2) 0.5 ml of octadecyltrichlorosilane was added to 50 ml of perfluoropentane, and a cellulose acetate resin plate (10 cm × 10 cm) formed into a thickness of 1 mm was formed.
cm) was soaked and allowed to stand at room temperature for 30 minutes.

Take out the cellulose acetate resin plate,
It was washed by shaking several times in 50 ml of perfluoropentane and then dried. Crushed scraped off the surface of the cellulose acetate resin plate was measured for infrared absorption spectrum in KBr pellet method, 3200 cm ^-1 vicinity (attributable C-
H) Absorption was observed in the vicinity of 1060 cm ⁻¹ (attributable Si—O), and it was confirmed that the silane compound was bonded and fixed on the cellulose acetate resin plate as shown in FIG.

FIG. 2 is a schematic sectional view of the vicinity of the surface of a cellulose acetate resin plate, in which 21 is a cellulose acetate resin molding and 22 is a coating film made of a silane compound. Y in the figure is, C ₁₈ H ₃₇ - represents a.

The contact angle of the cellulose acetate resin plate with water was 70 ° before the treatment and 90 ° after the treatment, and the water repellency was imparted. The transparency of the cellulose acetate resin plate did not change before and after the treatment.

(Example 3) A cellulose acetate resin plate (10 cm x 10 cm) molded to a thickness of 1 mm had a density of 10
It was immersed in an aqueous solution of sodium hydroxide of wt% and heated at 60 ° C. for 1 hour.

By this treatment, the contact angle of the cellulose acetate resin plate with water is 70 ° before the treatment and 4 after the treatment.
It became 2 °, and hydrophilicity was imparted. A part of the above cellulose acetate resin plate was masked with a polyimide adhesive tape, and immersed in a solution in which 0.5 ml of (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trichlorosilane was added to 50 ml of perfluoropentane. Then, it was allowed to stand at room temperature for 30 minutes.

Take out the cellulose acetate resin plate,
After shaking and washing several times in 50 ml of perfluoropentane, the adhesive tape was peeled off and dried. The contact angle of the cellulose acetate resin plate with water is 4 for the masking part.
The angle was 2 ° and 110 ° except for the masking part, and the masking part was hydrophilic and the others were water repellent.

The transparency of the cellulose acetate resin plate did not change before and after the treatment. (Example 4) A transparent molded plate for ski goggles made of cellulose acetate resin was immersed in an aqueous sodium hydroxide solution having a concentration of 10% by weight, and heated at 60 ° C for 1 hour.

By this treatment, the entire surface of the transparent molded plate was rendered hydrophilic. The entire face side of the transparent molded plate was masked with a polyimide adhesive tape, and immersed in a solution in which 0.5 ml of (heptadecafluoro-1,1,2,2-tetrahydrodecyl) trichlorosilane was added to 50 ml of perfluoropentane. Then, it was allowed to stand at room temperature for 30 minutes.

The transparent molded plate was taken out, shaken and washed several times in 50 ml of perfluoropentane, and then the adhesive tape was peeled off and dried. The contact angle of water on the surface of the transparent molded plate was 45 ° on the face side and 113 ° on the outside air side. The face side was hydrophilic and the outside air side was water repellent.

Before and after the treatment, there was no change in the transparency of the transparent molded plate. When the transparent molded plate was fixed so that the outside air side had an inclination of 45 ° and water droplets were dropped onto the outside air side, it was confirmed that all water droplets with a volume of 3 μl or more fell off and the water droplets were hard to adhere. He blew on his face, but it didn't cloud.

Fine water droplets were attached to the outside air side of the transparent molded plate with a mist blower and frozen in a freezer at -10 ° C. It was confirmed that all the ice was removed by rubbing once with a cotton cloth while applying a load of about 40 g / cm ² , and it was difficult for the ice to adhere.

When muddy water was dropped on the outside air side of the transparent molded plate, all the muddy water was removed simply by vertically standing and shaking the transparent molded plate. The transparent molded plate, which was dried by placing muddy water on the outside air side, was removed by rubbing it once with a cotton cloth having a load of about 40 g / cm ² .

The transparent molded plate was rubbed with a sponge containing a neutral detergent 200 times and washed with water, but the contact angle to water, the ease of removing water droplets, ice and dirt were not changed, and the water repellency was maintained. In addition, helmet visor made of cellulose acetate resin, eyeglass frame, eyeglass lens, sunglasses,
The same results were obtained when the same examination as in Example 4 was carried out for the vehicle window. However, the spectacle frame was tested on its entire surface treated with water repellent.

Comparative Example 1 A transparent molded plate for ski goggles made of cellulose acetate resin was washed with a detergent to obtain a transparent molded plate for Comparative Example.

The transparent molded plate was fixed so that the outside air had an inclination of 45 °, and when water droplets were dropped on the outside air side, most of the water droplets with a volume of 20 μl or less adhered, and compared with the transparent molded plate of Example 4. It was confirmed that water droplets tended to adhere.

Fine water droplets were attached to the outside air side of the transparent molded plate with a mist blower and frozen in a freezer at -10 ° C. Rubbing with a cotton cloth under a load of about 40 g / cm ² did not remove the ice. When the load was increased to about 100 g / cm ² and rubbed 10 times, about 60% of the ice was removed, and it was confirmed that the ice was more likely to adhere to the transparent molded plate of Example 4.

Muddy water was dropped on the outside air side of the transparent molded plate, and the transparent molded plate was vertically erected and shaken, but the muddy water spreads and almost adhered. In addition, when the muddy water adhering to the outside air of the transparent molded plate is dried, the load is about 40 g / cm ²
Even if it was rubbed once with the cotton cloth, 50% or more remained.

[0069]

As described above, in the water-repellent resin molded product of the present invention, an alkyl group or a fluoroalkyl group is covalently fixed to at least a part of the surface of the cellulosic resin molded product. The resin molded product has a high antifouling effect such that no dirt or dirt adheres, or even if it adheres, it is easily removed. Moreover, the effect is maintained for a long time without being impaired by washing or the like.

Further, an alkyl group or a fluoroalkyl group is covalently fixed to a part of the surface of the cellulosic resin molded product, and the remaining surface has a hydroxyl group. A water-repellent resin molded product that is water-repellent and the remaining surface is hydrophilic can be obtained. Since the hydrophilic part generally has good adhesiveness with adhesives etc., something is processed on this part to bond another object. It is extremely effective when you want to.

Further, the cellulose resin is any one of cellulose acetate, cellulose propionate, cellulose butyrate and regenerated cellulose, or a mixture thereof or a resin mixture containing 30% by weight or more thereof, These resins are preferred because they are industrially easily available and relatively inexpensive.

By making the preferred embodiment of the present invention in which the covalent bond is a Si--O bond, an alkyl group is formed on the surface of the cellulosic resin molded article by using a silane compound that is easily available and has a very simple reaction operation. Alternatively, it is possible to easily realize a cellulose resin molded product having a water-repellent surface having a fluoroalkyl group fixed by a covalent bond.

By making the preferred embodiment of the present invention in which the cellulosic resin molded article is a transparent cellulosic resin molded article, the transparency and durability of goggles, helmet visors, spectacle lenses, sunglasses, or vehicle windows are improved. It is possible to provide a cellulosic resin molded product which is useful in applications where impact resistance is required and water droplets and stains do not easily occur.

Cellulose resin moldings are goggles, helmet visors, spectacle lenses, sunglasses,
Alternatively, a resin plate used for a vehicle window, wherein one surface of the cellulose resin plate has a hydroxyl group and the other surface has an alkyl group or a fluoroalkyl group fixed by a covalent bond. By doing so, it is difficult for water drops, ice, and dirt to adhere to the surface on the outside air side, and it is possible to keep good visibility because the other surface is less likely to fog.Useful for goggles, helmet visors, eyeglass lenses, sunglasses, or vehicle windows. Can be made of a different resin plate.

Further, according to the method for producing a water-repellent resin molded product of the present invention, not only the resin molded product whose entire surface is water-repellent but also one surface or an arbitrary part of the surface is repelled. It is possible to provide a method for producing a water-repellent resin molded product, which is capable of easily producing an aqueous resin molded product with the remaining hydrophilic.

Further, in the method for producing a water-repellent resin molded product of the present invention, the surface is hydrolyzed by providing a preferred embodiment in which the cellulose-based resin molded product is a cellulose-based resin molded product in which only the surface is hydrolyzed. As a result, a large number of hydroxyl groups are present on the surface, so there are many reaction sites with the silane compound, a water-repellent resin molded product can be easily produced, and the hydrolyzed portion is When leaving a part, the adhesiveness of that part is good, which is convenient when performing a bonding process with other necessary objects, and the part is less likely to be fogged by water vapor or the like, which is preferable.

[Brief description of drawings]

FIG. 1 is a surface structure diagram of a cellulose acetate resin molded article in Example 1 of the present invention.

FIG. 2 is a surface structure diagram of a cellulose acetate resin molded article in Example 2 of the present invention.

[Explanation of symbols]

 11,21 Cellulose acetate resin molded product 12,22 Coating made of silane compound

Claims (8)

[Claims] 1. A water-repellent resin molded product, wherein an alkyl group or a fluoroalkyl group is covalently fixed to at least a part of the surface of the cellulose resin molded product, at least a part of the surface of which is water repellent. . 2. An alkyl group or a fluoroalkyl group is covalently fixed to a part of the surface of the cellulose resin molded product, and the remaining surface has a hydroxyl group. The water-repellent resin molded product according to claim 1, which is water-based and the remaining surface is hydrophilic. 3. The cellulosic resin is any one of cellulose acetate, cellulose propionate, cellulose butyrate and regenerated cellulose, or a mixture thereof or a resin mixture containing 30% by weight or more thereof. The water-repellent resin molding described. 4. The covalent bond is a Si—O bond.
4. The water-repellent resin molded product according to any one of to 3. 5. The water repellent resin molded product according to claim 1, wherein the cellulose resin molded product is a transparent cellulose resin molded product. 6. The cellulose resin molded article is a resin plate used for goggles, helmet visors, spectacle lenses, sunglasses, or vehicle windows, wherein one surface of the cellulose resin plate has a hydroxyl group and the other surface thereof has a hydroxyl group. A one-sided hydrophilic one-sided water-repellent plate-shaped resin molded product, wherein an alkyl group or a fluoroalkyl group is fixed to the surface by a covalent bond. 7. A silane compound having at least one selected from an alkoxy group, an acetoxy group, an isocyanate group, and a halogen bonded to a silicon atom and having an alkyl group or a fluoroalkyl group is added to at least one surface of a cellulose resin molded article. A method for producing a water-repellent resin molded product, at least a part of the surface of which is water-repellent, characterized in that the method comprises a step of contacting the part. 8. The method for producing a water-repellent resin molded article according to claim 7, wherein the cellulose resin molded article is a cellulose resin molded article whose surface is hydrolyzed only.