JPH0782397A - Hydrophilic and lipophilic film and preparation thereof - Google Patents

Abstract

PURPOSE:To obtain a hydrophilic and lipophilic film excellent in antifogging ability, etc., by forming an inorganic hard film on a plastic film, forming minute unevenness on the surface and forming a chemisorbing monomolecular film on the surface. CONSTITUTION:This film is prepared by forming an inorganic hard film 12 on a plastic film 11, forming minute unevenness 13 with appropriate roughness by etching the surface through plasma discharge in a gas containing C and F, and forming a chemisorbing monomolecular film 14 on the surface. Thus, there is provided a functional film that has a good transparency, excellent hydrophilic and lipophilic properties and a surface strength sufficient for practical use. When a molecule having methylene groups in the main chain and trichlorosilane groups at the ends is used as a chemisorbing agent by way of example, the -OH and silyl groups on the surface of the inorganic hard film are dehydrochlorinated and fixed by a covalent bond.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic film having enhanced functionality and a method for producing the same.
More specifically, the present invention relates to a hydrophilic / lipophilic film used as an anti-fog film attached to the inside of a rear window of a vehicle, the inside of a seal of a helmet, or the like, and a method for producing the same.

[0002]

2. Description of the Related Art In order to have hydrophilic lipophilicity, it is necessary to make its surface tension higher than that of water or oil. Generally, a hydrophilic film having a contact angle with water of about 20 degrees or less is practically desirable. As a conventional hydrophilic / lipophilic film, it is generally practiced to impart hydrophilicity by coating a hydrophilic coating agent on the surface of a general-purpose film such as a polyester film.

[0003]

However, in the conventional hydrophilic / lipophilic film, the coating film and the substrate are simply adhered to each other only by the anchor effect, so that in view of environment resistance and surface strength (durability). Inferior.

As a method for obtaining the superhydrophilic lipophilic state, the present inventors have also made a trial of a hydrophilic lipophilic film which combines the morphological effect of the film surface and the material hydrophilic lipophilic effect of the coating film. The surface strength did not reach the practical strength.

In order to solve the above-mentioned conventional problems, the present invention provides a low-cost hydrophilic / lipophilic film which maintains transparency of the film, has superhydrophilicity, and has surface strength capable of withstanding practical strength. The purpose is to do.

[0006]

In order to achieve the above object, the present invention provides a plastic film, an inorganic hard film on which at least one surface of a plastic film is formed with minute unevenness, and a fine unevenness on the inorganic hard film. And a chemisorption monomolecular film containing fluorine formed through a siloxane bond.

In the above structure, it is preferable that the inorganic hard film is an oxide and / or a nitride containing silicon. Further, in the above structure, the thickness of the inorganic hard film is preferably 0.02 to 10 μm.

Further, in the above structure, the roughness of the unevenness of the inorganic hard film is preferably 0.01 to 0.3 μm. Further, in the above structure, it is preferable that the back surface of the plastic is coated with an adhesive.

Next, the first method for producing a hydrophilic / lipophilic film of the present invention comprises a step of forming an inorganic hard film on at least one side of a plastic film, and the surface of the inorganic hard film in a gas containing C and F. Plasma discharge treatment with
A step of forming fine irregularities, a step of subjecting the surface of the inorganic hard film formed on the irregularities to a plasma discharge treatment with a gas containing at least oxygen to make the surface of the irregularities hydrophilic, and the inorganic hard film formed on the irregularities. The plastic film formed on the surface is immersed in a solution in which a compound containing at least two chlorosilyl groups is dissolved in a non-aqueous solvent to form a chemisorption monomolecular film on the uneven surface of the inorganic hard film via a siloxane bond. And a step of performing

Next, a second method for producing a hydrophilic / lipophilic film of the present invention comprises a step of forming an inorganic hard film on at least one side of a plastic film, and a step of forming the surface of the inorganic hard film in a gas containing C and F. Plasma discharge treatment with
A step of forming minute irregularities, a step of subjecting the surface of the inorganic hard film formed on the irregularities to a plasma discharge treatment with a gas containing at least oxygen to make the surface of the irregularities hydrophilic, and a surface of the inorganic hard film formed on the irregularities A compound containing at least two chlorosilyl groups or a solution obtained by diluting the compound with a solvent is made into a gas state in the plastic film formed above, and the uneven surface of the inorganic hard film is chemically formed by a gas phase in the gaseous atmosphere. And a step of forming an adsorption film through a siloxane bond.

[0011]

According to the structure of the present invention, an inorganic hard film is formed on the film, and the surface is made finely uneven, instead of directly making the surface of the film finely uneven.
The inorganic hard film can make up for the weakness of the film surface strength, and the fine irregularities of the inorganic hard film can exert an excellent hydrophilic and lipophilic effect. Further, the minute unevenness is 0.01 to 0.
Since it has a roughness of 3 μm, it has excellent light transmittance and does not interfere with the transparency of the film. Furthermore, since the surface of the inorganic hard film and the chemical adsorption film containing fluorine are formed through the siloxane bond, a transparent hydrophilic lipophilic film having excellent hydrophilic and lipophilic properties, weather resistance and surface strength. Can be

The inorganic hard film has a thickness of 0.02 to 1
According to the preferable constitution of the present invention of 0 μm, the light transmittance of the film in the visible light region is not hindered. Further, according to the preferable configuration of the present invention in which the inorganic hard film is an oxide film containing silicon or a nitride film, minute irregularities can be formed relatively easily.

Further, according to the preferable constitution of the present invention in which the back surface of the film is coated with the adhesive, it can be easily attached to the substrate to be adhered. Next, according to the first to second production methods of the present invention, the hydrophilic lipophilic film of the present invention can be efficiently and rationally produced.

[0014]

【Example】

(Embodiment 1) Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a constitutional view of the hydrophilic / lipophilic film of the present invention. FIG. 2 is an enlarged view of part B of FIG. 1 to the molecular level.

In FIG. 1, 11 is a 100 μm-thick polyethylene terephthalate (PET) film, 12 is a 2 μm-thick silicon oxide film formed on the PET film 11, and 13 is minute unevenness formed on the silicon oxide 12. Reference numeral 14 is a chemisorption monomolecular film.

First, the procedure for producing the hydrophilic / lipophilic film will be described. First, the PET film 11 is placed in a vacuum container, and an SiO ₂ target is sputtered with an RF discharge power of 400 W in an argon gas held at 0.4 Pa to obtain P
A 2 μm thick silicon oxide film 12 was formed on the ET film 11.

Next, the surface of the silicon oxide film 12 is subjected to C and F.
While supplying a gas containing the above to the surface of PET 11 in a shower shape, the silicon oxide 12 was etched using a plasma discharge with a discharge power of 150 W to form minute irregularities 13. At this time, the roughness of the fine irregularities 13 was 0.2 μm after the etching time was 3 minutes, and the transparency of the film was not lost. Next, in order to activate (hydrophilic) the surface of the minute unevenness 13, the surface of R
A plasma treatment was performed for 5 minutes with an F discharge power of 100 W.
The film thus treated was taken out of the container and diluted with a solvent of cyclohexane to obtain 1 × 10 ^-2 Mol.
It was immersed for 10 minutes in a solution of a compound (Chemical formula 1) containing chlorosilane groups at both ends at a concentration of 1 / l.

[0018]

[Chemical 1]

Then, since the surface of the silicon oxide film 12 on which the minute irregularities 13 are formed is hydrophilized by the plasma treatment containing oxygen, the bond of (Chemical Formula 2) is formed on the surface, and the compound (Chemical Formula 2) is formed. Chemisorption monolayer 1)
4 was formed (Fig. 2).

[0020]

[Chemical 2]

That is, when, for example, a molecule having a methylene group in the main chain and a trichlorosilane group at both ends is used as the chemical adsorbent, the --OH group on the surface of the inorganic hard film and the silyl group of one molecule are dehydrochlorinated. And are fixed by covalent bonds. The other silyl group is hydrolyzed by moisture in the air, etc., and the terminal becomes a hydroxyl group to exhibit hydrophilicity. On the other hand, the main chain of chemisorption molecule is methylene group,
Lipophilicity is exhibited. Further, since the chemisorption film has a thickness of angstrom or nanometer level, it has excellent transparency.

In order to evaluate the hydrophilicity, lipophilicity and transparency of the hydrophilic / lipophilic film thus produced, the contact angle to water / hexadecane and the transmittance were measured. As a comparative sample, a PET film coated with a hydrophilic coating agent {"Si Coat T2" (a silicon-based hard coating agent manufactured by Daihachi Chemical Industry Co., Ltd.)}, an untreated PET film, a PET film on which only a chemical adsorption film is formed, and a minute film The same measurement was performed on a PET film having a chemisorption monomolecular film formed on the surface of the film having irregularities.

The measurement results are shown in (Table 1).

[0024]

[Table 1]

As is clear from this (Table 1), it was found that the hydrophilic / lipophilic film produced in Example 1 was a functional film excellent in hydrophilicity, transparency and surface strength.

Further, the hydrophilic / lipophilic film prepared in this Example 1 and P coated with the hydrophilic coating agent of Comparative Example were applied.
When the ET film is left at room temperature (25 ° C.), in a high humidity atmosphere (40 ° C., 95%), and subjected to various environmental tests such as atmospheric exposure, the product of this example does not lose its hydrophilic and lipophilic properties up to 1000 hours. Although the environmental resistance was also sufficiently satisfactory, the comparative example product deteriorated in characteristics in a high humidity atmosphere leaving test and an atmospheric exposure test by 500 hours.

Example 2 A procedure for producing a hydrophilic / lipophilic film will be described with reference to the drawings. FIG. 3 is a schematic view of a chemical adsorption film forming apparatus for producing the hydrophilic / lipophilic film of the present invention. In FIG. 3, 21 is a PET film on which a silicon oxide film is formed, 25 is a vacuum container, 2
Reference numeral 6 is a closed container, 27 is a compound (Chemical Formula 1) in which both ends are contained in the closed container 26 (chemical formula 1), and 28 is a cock of the closed container.

After depositing a 2 μm silicon oxide film on the PET film 21 in the same manner as in Example 1, minute irregularities having a roughness of 0.2 μm are formed on the surface of the silicon oxide film, and the surface is exposed to oxygen gas. Activated (hydrophilic) by included plasma discharge treatment
Turn into. Next, the inside of the vacuum container 25 is evacuated to 1 × 10 ⁻³ Pa. The cock 28 of the closed container 26 is opened to vaporize the stock solution of the compound (Formula 1) 27 having chlorosilane at both ends.

Then, since the surface of the silicon oxide film subjected to the plasma treatment is hydrophilized, a bond of (chemical formula 2) is formed between the vaporized compound (chemical formula 1) and the surface of the silicon oxide film, and the compound (chemical formula 1) is formed. ) Containing a chemisorption monolayer.

The hydrophilic / lipophilic film thus obtained was compared with the hydrophilic / lipophilic film prepared in Example 1, and there was no difference in characteristics. That is, it was a functional film excellent in terms of water repellency, transparency, surface strength, and environment resistance as in Example 1.

At the same time, it is possible to collectively form a film in the same vacuum container, so that the process time can be shortened and the cost can be reduced. (Example 3) A procedure for producing a hydrophilic lipophilic film will be described.

FIG. 4 is a sectional conceptual view in which the surface of silicon oxide after forming the siloxane monomolecular film which is the third embodiment of the present invention is enlarged to the molecular level. FIG. 5 is a conceptual cross-sectional view in which the surface of silicon oxide after forming the chemisorption monomolecular film containing fluorine according to the third embodiment of the present invention is enlarged to the molecular level.

In FIG. 4, 32 is a silicon oxide film formed on the PET film, and 39 is a siloxane monomolecular film. In FIG. 5, 34 is a chemisorption monomolecular film.

As in Example 1, 2 on the PET film.
After forming the silicon oxide film 32 having a thickness of μm, minute irregularities 33 having a roughness of 0.2 μm are formed on the surface of the silicon oxide film 32, and the surface is activated (hydrophilic) by a plasma treatment containing oxygen gas. . Then, 1 in a solution of 2 × 10 ^-2 Mol / l concentration of SiCl ₄ diluted with cyclohexane solvent.
Soak for 0 minutes.

Then, since the surface of the silicon oxide film 32 is made hydrophilic by the plasma treatment containing oxygen, a dehydrochlorination reaction occurs on the surface, and the molecules are converted to --SiO 2 as in (Chemical Formula 3) and (Chemical Formula 4). -Fixed to the surface via a bond.

[0036]

[Chemical 3]

[0037]

[Chemical 4]

After that, when washed with a non-aqueous solvent such as cyclohexane and further washed with water, SiCl ₄ molecules which have not reacted with the film are removed, and as shown in FIG. It is obtained in a state where the siloxane monomolecular film 39 such as 6) is chemically bonded.

[0039]

[Chemical 5]

[0040]

[Chemical 6]

Next, 1 diluted with a solvent of cyclohexane
It is immersed for 10 minutes in a solution of a compound (Chemical Formula 1) containing a chlorosilane group at a concentration of × 10 ^-2 Mol / l. Then, since the silicon oxide film surface 32 on which the minute irregularities 33 are formed contains a large number of hydroxyl groups by the above-mentioned chemical treatment, a dehydrochlorination reaction occurs on the surface and a bond of (Chemical Formula 2) is generated, A chemisorption monomolecular film 34 is formed by the compound (Chemical Formula 2) (FIG. 5).

Further, this film could be formed with a higher density than in Example 1. When the hydrophilic and lipophilic films produced in this example and Example 1 were compared, the transparency, surface strength and environment resistance were exactly the same, and the hydrophilicity was even better than that of the hydrophilic and lipophilic film of Example 1. It was a thing.

In Example 2, the solution to be vaporized from the closed container was the stock solution of the compound (Chemical formula 1), but the effect does not change even if the solution is diluted with a non-aqueous solvent such as cyclohexane.

In Example 2, when the molecular weight of the chlorosilane compound becomes large, that is, when the number of carbons becomes large, it becomes difficult to evaporate, but it can be dealt with by appropriately heating the stock solution. However, in the case of a straight chain, the number of carbon atoms is preferably up to about 25.

Incidentally, the embodiment 1 or 2, or 3,
In, the compound to be adsorbed is compound (Chemical formula 1), SiC
l ₄ was used, but other chlorosilane group-containing compounds such as SiHCl ₃ , SiH ₂ Cl ₂ , Cl- (SiC
l ₂ O) _n -SiCl ₃ (n is an integer), Cl ₃ Si-
_{(CH 2) n -SiCl 3 (} n is an integer) can obtain the same effect even like, or mixtures thereof.

The surface roughness of the inorganic hard film was 0.2 μm in this example, but when it was 0.01 μm or less, sufficient hydrophilicity could not be obtained. The mechanical strength of the surface of the film is not only weakened as much as possible, but also the transparency is deteriorated.
It is 3 μm.

In the present embodiment, the thickness of the silicon oxide film is set to 2 μm, but if it is thinner than 0.02 μm, it becomes impossible to form sufficient minute irregularities. That is, sufficient hydrophilicity and lipophilicity cannot be obtained, and if the thickness exceeds 10 μm, not only the flexibility of the film is lost but also the adhesive force of the film is extremely deteriorated, so that the thickness is preferably 0.02 to 10 μm.

In this embodiment, the silicon oxide film is used as the inorganic hard film, but other inorganic oxides, nitrides, sulfides and the like can also be used to obtain the same effect. However, an oxide film containing silicon and / or a nitride film is preferable from the viewpoint of easy formation of fine protrusions on the film surface.

Further, the method for producing the inorganic hard film is not limited to sputtering. Further, in this embodiment, P
Although the ET film was used, it goes without saying that similar results can be obtained with other plastic films such as polyimide film, polyamide film, polyethylene film, polypropylene film, polycarbonate film, and trifluorochloroethylene.

Further, if an adhesive is attached to the back surface of the film of the present invention, it can be easily attached to the substrate to be adhered without affecting the optical characteristics. A release sheet may be present on the surface of the pressure-sensitive adhesive.

[0051]

INDUSTRIAL APPLICABILITY As described above, the present invention comprises a plastic film, an inorganic hard film having fine irregularities formed on the film, and a chemisorption monomolecular film formed on the fine irregularities through a siloxane bond. As a result, a transparent film having a very high hydrophilic / lipophilic effect can be obtained. In addition, since the chemisorption monomolecular film on the surface is chemically bonded to the inorganic hard film, it does not peel off or deteriorate, and has excellent durability, heat resistance, weather resistance, and abrasion resistance. A lipophilic film can be provided and its practical effect is great.

[Brief description of drawings]

FIG. 1 is a constitutional view of a hydrophilic / lipophilic film in Example 1 of the present invention.

FIG. 2 is a cross-sectional view in which a portion B in FIG. 1 in Example 1 of the present invention is enlarged to a molecular level.

FIG. 3 is a schematic view of a chemical adsorption film forming apparatus for producing a hydrophilic / lipophilic film in Example 2 of the present invention.

FIG. 4 is a cross-sectional view in which the surface of the hydrophilic / lipophilic film in Example 3 of the present invention is enlarged to the molecular level.

5 is a cross-sectional view after forming a chemisorption monolayer on the surface of the hydrophilic / lipophilic film shown in FIG.

[Explanation of symbols]

 11 polyethylene terephthalate (PET) film 12 silicon oxide film 13 minute irregularities on a silicon oxide film 14 chemisorption monomolecular film 21 polyethylene terephthalate (PET) film 25 vacuum container 26 closed container 27 compound containing chlorosilane group 28 cock of closed container 32 silicon oxide film 34 chemisorption monomolecular film 39 siloxane monomolecular film

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazufumi Ogawa 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (7)

[Claims] 1. A plastic film, an inorganic hard film having minute irregularities formed on at least one surface of the plastic film, and a chemisorption monomolecular film formed on the minute irregularities of the inorganic hard film through siloxane bonds. A hydrophilic and lipophilic film consisting of. 2. The inorganic hard film is at least one film selected from an oxide film containing silicon and a nitride film.
The hydrophilic / lipophilic film according to. 3. The inorganic hard film has a thickness of 0.02 to 10 μm.
The hydrophilic / lipophilic film according to claim 1 or 2, which is in the range. 4. The roughness of fine irregularities is 0.01 to 0.3 μm.
The hydrophilic / lipophilic film according to claim 1, which is in the range of m. 5. The hydrophilic / lipophilic film according to claim 1, wherein an adhesive is applied to the back surface of the plastic film. 6. A step of forming an inorganic hard film on at least one surface of a plastic film, and a step of subjecting the surface of the inorganic hard film to plasma discharge treatment in a gas containing C and F to form minute irregularities, The inorganic hard film surface formed in the unevenness is subjected to plasma discharge treatment with a gas containing at least oxygen to make the uneven surface hydrophilic, and the plastic film formed on the surface of the inorganic hard film formed in the unevenness A step of immersing a compound containing at least two chlorosilyl groups in a non-aqueous solvent to form a chemisorption monomolecular film on the uneven surface of the inorganic hard film through a siloxane bond. Manufacturing method. 7. A step of forming an inorganic hard film on at least one surface of a plastic film, and a step of performing plasma discharge treatment on the surface of the inorganic hard film in a gas containing C and F to form minute irregularities, The inorganic hard film surface formed in the unevenness is subjected to plasma discharge treatment with a gas containing at least oxygen to make the uneven surface hydrophilic, and at least the plastic film formed on the surface of the inorganic hard film formed in the unevenness A compound containing two chlorosilyl groups,
Alternatively, a step of forming a solution of the compound diluted with a solvent into a gas, and forming a chemisorption film on the uneven surface of the inorganic hard film through a siloxane bond in a gas phase in a gas phase through a siloxane bond. Manufacturing method.