JPH07118421A - Hydrophilic fluorine resin molded product - Google Patents

Abstract

(57) [Summary] [Object] The present invention provides a hydrophilic fluororesin molded article in which the surface of a fluororesin molded article is modified. [Structure] At least a part of the fluororesin molded product,
By irradiating an ultraviolet laser beam having a wavelength of 400 nm or less with a gas-treated water obtained by introducing a gas such as hydrogen gas or nitrogen gas in contact, The surface is modified to be hydrophilic. By doing so, for example, it is suitable for an artificial blood vessel having an excellent antithrombotic property, a material for a contact lens that does not discolor due to modification, etc. Further, it can be expected to be used in a wide range by utilizing the functionality.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hydrophilic fluororesin molded product obtained by modifying a fluororesin molded product to be hydrophilic.

[0002]

2. Description of the Related Art In general, a molded article made of a fluororesin has an inactive surface, and in some cases, lacks hydrophilicity or adhesiveness, and its use is limited by itself. Therefore, conventionally, in order to modify the surface of a molded product made of a fluororesin, a method of treating in an alkali metal solution, a method of using plasma, B (CH ₃ ) ₃ gas or B ₂ H
The surface of a fluorine-based film or the like placed in an atmosphere of a mixed gas of ₆ and NH ₃ or the like is irradiated with F by excimer laser irradiation.
A method of substituting a group with a CH ₃ group or an NH ₂ group for modification (Japanese Patent Laid-Open No. 2-196834) has been known.

[0003]

However, in the above-mentioned various reforming methods, it is difficult to control the reforming due to the structural change of the surface of the fluororesin. For example, in the method of treating in an alkali metal solution, there are problems that there is a risk of ignition and instability of the treatment liquid, and that the modified portion is vulnerable to sunlight and high heat. In the plasma method,
There is a problem that the effect of surface modification is significantly lower than that of a resin containing no fluorine such as polyethylene. Also, B
The method of irradiating an excimer laser in an atmosphere such as (CH ₃ ) ₃ or a mixed gas of B ₂ H ₆ and NH ₃ requires not only cost for putting the apparatus used for the method into practical use but also toxicity. However, there is a problem in that it requires skillful operations such as the use of a strong special gas and decompression operation.

[0004]

As a result of various studies to solve the above problems, the present inventors have found that by using an ultraviolet laser beam having a wavelength of 400 nm (nanometer) or less under specific conditions. It has been found that a hydrophilic fluororesin molded product can be easily obtained, and finally the present invention has been completed.

That is, the present invention is a gas obtained by introducing hydrogen gas, nitrogen gas, and at least one gas selected from rare gases belonging to Group 0 of the periodic table into at least a portion of a fluororesin molded article. At least one of the above fluororesin molded articles is obtained by irradiating an ultraviolet laser beam having a wavelength of 400 nm or less in a state in which one of the treated water and the aqueous solution containing ammonium ions or a mixed solution of both of them is brought into contact with each other. The present invention relates to a hydrophilic fluororesin molded article in which the surface of a part is modified to be hydrophilic.

The ultraviolet laser having a wavelength of 400 nm or less used in the present invention is not particularly limited as long as it can emit ultraviolet light. Specifically, ArF
Excimer laser (wavelength 193 nm), KrF excimer laser (248 nm), XeCl excimer laser (308 nm), XeF excimer laser (351)
nm), various excimer lasers such as F ₂ excimer laser (157 nm), dye lasers, free electron lasers, and the like, and excimer lasers are particularly preferable. The fluence (energy density) of the ultraviolet laser light according to the present invention is not particularly limited, but is 1 to 20.
A preferable value is about 0 mJ / cm ² / pulse (millijoule / square centimeter / pulse). The wavelength of the ultraviolet laser light is 400 as described above.
nm or less is necessary, and preferably 120 to 380 nm
It is a degree. If the wavelength of the ultraviolet laser light exceeds 400 nm, there is a problem that it becomes difficult to modify it to be hydrophilic.

To modify the surface of a fluororesin molded article to be hydrophilic, for example, a C--F bond, a C--C bond, a C--O bond or the like derived from the fluororesin on the surface of the molded product is used. ,
It is presumed that it is preferable to at least partially cleave the C—F bond, but there are uncertain aspects. The condition is that the absorption of the oscillation wavelength of an ultraviolet laser having a wavelength of 400 nm or less used for cutting is within the range of the ultraviolet absorption spectrum of the fluororesin, and the photon energy of the excimer laser light is that of the fluororesin described above. It is desirable that the bond energy be larger than the bond energy. However, this is not particularly limited, and it is presumed that even in the case of an ultraviolet laser beam in which the energy of one photon is smaller than the binding energy, cutting can be achieved by causing multiphoton absorption, but the fact is not clear. Is.

For example, when the above bond of the fluororesin is broken to satisfy the above conditions, when using the gas-treated water into which the specific gas according to the present invention is introduced, that portion is caused by the gas-treated water. It is presumed that it will be replaced with an H group, an OH group, a COOH group, a CO group or the like to be modified to be hydrophilic, but it is not clear that this is the case, and the aqueous solution containing ammonium ion according to the present invention is used. In that case, the portion is NH ₂ group, H group, OH group, CO derived from the aqueous solution according to the present invention.
It is presumed that it is replaced with an OH group, a CO group, or the like to be modified to be hydrophilic, but the fact is not clear.

When the gas-treated water prepared by introducing the specific gas according to the present invention is used, the cut-off F is combined with H resulting from the gas-treated water prepared by introducing the specific gas and removed. It is presumed to be one, but it is uncertain. Further, the ultraviolet laser light activates both the gas-treated water and the surface of the fluororesin molded article, and in particular, the gas acts as an energy transfer agent to activate and form a polar group on the molded article surface. , There are some aspects that are supposed to have an effect, but this is not certain.

Further, when the aqueous solution containing ammonium ions according to the present invention is used, it is presumed that the above-mentioned cleaved and released F is bound to H resulting from the aqueous solution and removed.
At this time, the reason for the binding is, for example, that the binding energy of HF is 135 Kcal / mol, which is larger than the binding energy of C-F 129 Kcal / mol, so that C-
It is presumed that it binds more easily than F, stabilizes in this state, and does not release F again, but the fact is uncertain.

Although all of the above have been described by estimation, it is considered that these will eventually be elucidated by future research.

Examples of rare gases belonging to Group 0 of the periodic table used in the present invention include helium gas, neon gas, argon gas, krypton gas and xenon gas.

In the present invention, these rare gases, hydrogen gas and nitrogen gas are at least one kind, that is, one kind alone or 2 kinds.
A mixture of two or more species can be used.

Various methods are conceivable for preparing the gas-treated water by introducing such a gas, and there is no particular limitation. Usually, it is prepared by contacting the gas with various kinds of water described later. . Upon contact, the gas may be blown into water or water may be positively added to the gas. Further, the gas phase may be provided on the water surface, and there is no particular limitation on the contacting method. By bringing them into contact with each other in this manner, the gas is dissolved in water or exists in the form of fine bubbles in water.
However, the gas-treated water in which the gas phase is provided on the water surface has some points that it is unclear whether the gas is dissolved in water or exists in the water in the form of bubbles. Such gas-treated water is also within the scope of the present invention because the desired effect of (1) is exhibited. As described above, in the present invention, the gas does not necessarily have to be dissolved in water or exist as bubbles in water. The amount of such gas in water is not particularly limited, but when it is dissolved in water, it can be about 10 ^-2 to 10 ^-5 wt%.

The aqueous solution containing ammonium ions used in the present invention means an aqueous solution containing a compound that produces ammonium ions (NH ₄ ⁺ ) in a state of being dissolved in water. Examples of such compounds include inorganic compounds such as ammonia, ammonium hydroxide, ammonium carbonate, ammonium sulfate, ammonium nitrate, ammonium bicarbonate, ammonium thiocyanate, ammonium chloride and ammonium persulfate, and organic compounds such as Examples thereof include organic carboxylic acid salts such as ammonium formate, ammonium oxalate, ammonium citrate and ammonium acetate, and various ammonium complex salts. In addition, compounds such as methylammonium and hydroxylammonium obtained by substituting the hydrogen atom of NH ₄ with another group also belong to the category of compounds that produce ammonium ions in the state of being dissolved in water as described above. In the present invention, at least one kind of such compounds, that is, one kind alone or a mixture of two or more kinds can be used. The amount of such a compound to be added is not particularly limited, but it is usually preferable to add it so as to be contained in the aqueous solution at 10% by weight or less, preferably about 0.001 to 10% by weight.

According to the present invention, either one of the gas-treated water prepared by introducing the above-mentioned specific gas into at least a part of the fluororesin molded article and the above-mentioned aqueous solution containing ammonium ion, or a mixed solution of both of them. It is necessary to make contact. At this time, the mixed liquid of both may be a mixture of the aqueous solution containing the ammonium ion and the gas-treated water, which are prepared in advance, and then mixed.
It may be in a mixed state by introducing a specific gas into an aqueous solution containing ammonium ions, or conversely may be in a mixed state by adding the above-mentioned compound for producing ammonium ions into the gas-treated water. Alternatively, they may be in a mixed state at the same time, and the method for producing the mixed solution is not particularly limited. Further, it goes without saying that both liquids may be separately brought into contact in two steps.

If necessary, various third components may be added to the aqueous solution containing ammonium ions or the gas-treated water. Specific examples of such a third component include compounds having a metal element belonging to Group II of the periodic table, carboxylic acids, water-soluble polymer compounds, carbon monoxide, carbon dioxide, and the like.

In producing the liquid used in the present invention (hereinafter, the mixture is included when simply referred to as "liquid"), the water used is not particularly limited, and natural water, industrial water,
Examples of suitable water include tap water, distilled water, pure water, ion-exchanged water, and it is desirable to introduce the above-mentioned specific gas into such water or to mix or dissolve a compound that produces ammonium ions. In preparing the gas-treated water or the aqueous solution, it is not limited to the above-mentioned water, it may be dissolved in an aqueous solution of an acid or an alkali, and the concentration of the aqueous solution of the acid or the alkali is also particularly limited. However, aqueous solutions of such acids and alkalis are also included in the category of water described above. However, it is desirable to remove unnecessary impurities in water as much as possible.

Of the above-mentioned water, ordinary natural water, industrial water, tap water, etc. may contain a very small amount of various gases in the natural world, but this amount is extremely small,
Such water does not correspond to the aqueous solution containing ammonium referred to in the present invention or the gas-treated water obtained by introducing a specific gas.

The aqueous solution containing ammonium ions used in the present invention includes all liquids containing various kinds of water as a main component such as aqueous suspensions, aqueous dispersions and emulsions.

In order to bring the fluororesin molded product into contact with the liquid of the present invention, it is sufficient to bring the liquid into contact with at least a part of the molded product, that is, partially or entirely. Further, the contact method is not particularly limited, and for example, a method such as immersing the molded product in a liquid, placing the molded product on the liquid surface, or spraying the liquid onto the molded product surface by spraying, etc. Can be mentioned.

The fluororesin molded article according to the present invention has at least one part of its surface, that is, one part or the whole surface, which is modified to be hydrophilic. In order to modify a part of the surface of the molded product, the liquid of the present invention may be partially brought into contact with the surface of the molded product, or the liquid may be brought into contact with the entire surface of the molded product, and then the specific surface may be removed. The ultraviolet laser light may be partially irradiated, and there is no particular limitation. Further, there is no particular limitation for modifying the entire surface of the molded product to be hydrophilic, but for example, as described above, the molded product may be immersed in a liquid, or the molded product may be placed on the liquid surface. The surface of the molded product may be sprayed with a liquid and the entire surface may be irradiated with the laser light. At this time, the irradiation time is not particularly limited and can be appropriately selected depending on the type of ultraviolet laser, irradiation conditions, etc., but as a rough guideline, the incident energy amount (irradiated amount) is about 1 to 3000 J / cm ² ( An irradiation time of about joule / square centimeter) can be exemplified.

Irradiation of the ultraviolet resin light to the fluororesin molded product is not particularly limited, but it is desirable to wash the molded product with various cleaning agents such as alcohol prior to irradiation. By washing with a cleaning agent, it is possible to remove oil and dirt attached to the surface of the fluororesin molded product during the molding process, etc., and it is possible to obtain a product with high commercial value. The alcohol or the like is not particularly limited, but an alcohol having a low boiling point is more preferable because it does not adversely affect the reforming.

There are no particular restrictions on the fluororesin used as the material for the fluororesin molded article treated in the present invention,
Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), Examples thereof include fluorosilicone polymers synthesized from fluorocarbon and organic silicone, and mixtures thereof. An appropriate third component such as various synthetic resins and fillers may be added to such a fluororesin within a range that does not significantly modify the properties of the fluororesin.

Specific examples of the fluororesin molded article in the present invention include films, sheets, tubes, sleeves, tapes, filaments, knits, woven fabrics, strings, rods and powders made of fluororesins. However, the present invention is not limited to these and includes all fluororesin molded articles.
Such fluorocarbon resin molded products include fluorocarbon resin molded products such as composite molded products with other molded products such as synthetic resins, and composite molded products with natural fibers, chemical fibers, synthetic fibers, etc. Includes all complex compounds and the like used even in a small amount.

When a film is used as a fluororesin molded product, the thickness of the film is not particularly limited. For example, when the film is placed on the liquid, it can be about 1 mm or less. In such a case, There is also an advantage that the ultraviolet laser light passes through the film (for example, the transmittance is 95% or less, preferably 5 to 50%) and is modified at the contact interface between the liquid and the back surface of the film.

The fluororesin molded article of the present invention is suitable, for example, as a material for various artificial organs, and particularly when used as an artificial blood vessel, an artificial blood vessel having excellent antithrombotic properties can be obtained. Further, since it does not discolor due to modification, it can be used as a material for contact lenses, for example, and can also be used as one of composite materials by adhesion with a molded product made of another material or combination. In addition to these, a wide range of applications can be expected in all fields, and the applications are not particularly limited.

[0028]

EXAMPLES Next, the present invention will be further clarified with reference to examples, but the present invention is not limited to these.
The following examples will be described with reference to FIG. 1, which shows a schematic diagram of an excimer laser irradiation device that is one type of ultraviolet laser. The contact angle with water is Kyowa Interface Science Co., Ltd.
3 when using a CA-A type measuring machine manufactured by K.K.
It is the measured value of the contact angle after 0 seconds, and it is 3 for the same sample.
This is a value obtained by measuring twice and averaging the values.

Example 1 Reaction cell [5] made of stainless steel (a Petri dish may be used)
Into the above, gas-treated water obtained by blowing nitrogen gas into distilled water for 10 minutes was put, and a film (thickness 100 μm, light transmittance 7%) [7] made of PFA resin was brought into contact with the aqueous solution [6] (the aqueous solution). Placed in water 5 mm below the surface to make contact), then Ar formed through a metal mask [3]
A F-excimer laser (wavelength 193 nm) light [1] was focused by a convex lens [4] and irradiated perpendicularly to the film surface.
The irradiation conditions at this time were laser fluence 13 mJ / c.
m ² / pulse, the number of shots was 16000, and the frequency was 50 Hz.

The film [7] made of the PFA resin treated as described above has a contact angle with water of 70 degrees, which is excellent in hydrophilicity on the film surface as compared with the contact angle of 106 degrees of the unirradiated film. Indicated.

Example 2 Instead of the gas-treated water [6] of Example 1, gas-treated water obtained by blowing hydrogen gas into distilled water for 10 minutes was used, and a film made of PFA resin (thickness: 100 μm) in the aqueous solution.
[7] was brought into contact (placed in water 5 mm below the surface of the aqueous solution and brought into contact), and the ArF excimer laser light [1] similar to that in Example 1 was focused by a convex lens [4] to be perpendicular to the film surface. Irradiated. Irradiation conditions are laser fluence 13 mJ / cm ² / pulse, number of shots 16000
The shot has a frequency of 50 Hz.

The film [7] made of the treated PFA resin had a contact angle with water of 30 °, and the film surface showed excellent hydrophilicity.

Example 3 Instead of the gas-treated water [6] of Example 1, gas-treated water obtained by blowing helium gas into distilled water for 10 minutes was used, and a film made of PFA resin (thickness: 100 μm) was added to the mixed solution.
m) [7] is contacted in the same manner as in Example 1, and the same ArF excimer laser light [1] as in Example 1 is applied to the convex lens [4].
It was focused on and irradiated perpendicularly to the film surface. Irradiation conditions are laser fluence 13mJ / cm ² / pulses
e, the number of shots was 16,000, and the frequency was 50 Hz.

The film [7] made of the treated PFA resin had a contact angle with water of 40 degrees, and the film surface showed excellent hydrophilicity.

Example 4 A film made of PFA resin (thickness 100 μm) in gas-treated water in which argon gas was blown into distilled water for 10 minutes.
m) [7] is contacted in the same manner as in Example 1, and the same ArF excimer laser light [1] as in Example 1 is applied to the convex lens [4].
It was focused on and irradiated perpendicularly to the film surface. Irradiation conditions are laser fluence 13mJ / cm ² / pulses
e, the number of shots was 16,000, and the frequency was 50 Hz.

The film [7] made of the treated PFA resin had a significantly increased hydrophilicity as compared with the untreated one, and the contact angle was 34 degrees.

Example 5 A film made of PFA resin (thickness: 100 μm) in gas-treated water in which xenon gas was blown into distilled water for 10 minutes.
m) [7] is contacted in the same manner as in Example 1, and the same ArF excimer laser light [1] as in Example 1 is applied to the convex lens [4].
It was focused on and irradiated perpendicularly to the film surface. Irradiation conditions are laser fluence 13mJ / cm ² / pulses
e, the number of shots was 16,000, and the frequency was 50 Hz.

The film [7] made of the treated PFA resin had a contact angle with water of 53 degrees, and the film surface showed excellent hydrophilicity.

Example 6 A reaction cell [5] made of stainless steel (a Petri dish may be used).
An aqueous solution of ammonium having a concentration of 0.01% by weight is put into the solution, and a film (100 μm in thickness, light transmittance of 7%) [7] made of PFA resin is brought into contact with the aqueous solution [6] (on the surface of the aqueous solution). The surface of the film was not in direct contact with the aqueous solution.),
Then, an ArF excimer laser (wavelength 193 nm) light [1] formed through a metal mask [3] was focused by a convex lens [4] and vertically irradiated on the film surface. The irradiation conditions at this time were laser fluence 13 mJ / cm ²
/ Pulse, the number of shots was 16000, and the frequency was 50 Hz.

The film [7] made of the PFA resin treated as described above had a contact angle with water of 31 degrees, and the surface on the back side of the film exhibited excellent hydrophilicity.

Example 7 A 0.10% by weight aqueous ammonia solution was used in place of the aqueous solution [6] of Example 6, and a film made of PFA resin (thickness 100 μm) [7] was brought into contact with the aqueous solution [(6)]. The film was placed on the surface of the aqueous solution and brought into contact therewith, and the contact state was the same as in Example 6), and the same ArF excimer laser light [1] as in Example 6 was focused by a convex lens [4] and irradiated perpendicularly to the film surface. did. Irradiation conditions are laser fluence 13mJ
/ Cm ² / pulse, the number of shots was 16,000, and the frequency was 50 Hz.

The film [7] made of the treated PFA resin had a contact angle with water of 32 degrees, and the surface on the back side of the film exhibited excellent hydrophilicity.

Example 8 A 0.01% by weight aqueous solution of ammonium carbonate was used in place of the aqueous solution [6] of Example 6, and a film (thickness 100 μm) [7] made of PFA resin was used in the mixed solution. 6
The same contact as in Example 6 was performed, and the same ArF excimer laser light [1] as in Example 6 was focused by the convex lens [4] and irradiated perpendicularly to the film surface. Irradiation conditions are laser fluence 13 mJ / cm ² / pulse, number of shots 16000
The shot has a frequency of 50 Hz.

The film [7] made of the treated PFA resin had a contact angle with water of 57 degrees, and the surface on the back side of the film exhibited excellent hydrophilicity.

Comparative Example P was added to each of the nitrogen gas atmosphere and the helium gas atmosphere.
A film (thickness 100 μm) [7] made of FA resin was placed, and the surface of the film was irradiated with ArF excimer laser light [1] vertically. Irradiation conditions are laser fluence 1
3 mJ / cm ² / pulse, the number of shots was 16000, and the frequency was 50 Hz.

The film [7] made of PFA resin treated in any atmosphere was compared with the untreated one.
The surface was wavy and the appearance was impaired. Further, there was no great difference in the contact angle with water between the film and the untreated film, the former was 110 degrees and the latter was 107 degrees, and the hydrophilicity was not modified.

[0047]

According to the present invention, it is possible to realize a simple device by using a liquid that is easy to handle without using a complicated device or a highly toxic B ₂ H ₆ gas or NH ₃ gas as in the prior art. Moreover, it is possible to obtain a fluororesin molded article having excellent hydrophilicity by a simple operation. The hydrophilicity imparted by the present invention is extremely excellent, and the hydrophilicity is not likely to be altered by sunlight or heat. The hydrophilic fluororesin molded article of the present invention is, for example, an artificial blood vessel having excellent antithrombotic properties, various artificial organs, and since it does not discolor due to modification, it is also suitable as a material such as a contact lens. It is also suitable as a composite material with other molded products and can be expected to be used in various fields in the future by utilizing its excellent functionality.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a schematic view of an excimer laser irradiation device.

[Explanation of symbols]

 1 Excimer Laser Light 2 Mirror 3 Mask 4 Lens 5 Reaction Cell 6 Liquid 7 Fluorine Resin Molded Product (Film) 8 XY-Stage 9 Excimer Laser Oscillator

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Yuichi Shimizu 25-1 Mitsui Minamimachi, Neyagawa-shi, Osaka Prefecture Takasaki Research Institute, Japan Hara Research Institute Osaka Branch (72) Shunichi Kanishi 25, Miiminamimachi, Neyagawa-shi, Osaka Prefecture No. 1 Japan Hara Research Institute Takasaki Research Center Osaka Branch (72) Inventor Masanobu Nishii 25-1 Mitsui Minamimachi, Neyagawa City, Osaka Prefecture Japan Hara Research Center Takasaki Research Center Osaka Branch (72) Inventor Sugimoto Shunichi 25-1 Mitsuiminami-cho, Neyagawa-shi, Osaka Japan Hara Research Institute Takasaki Research Center Osaka Branch Radiation Irradiation Promotion Association

Claims (2)

[Claims] 1. Gas-treated water and ammonium obtained by introducing at least one kind of gas selected from hydrogen gas, nitrogen gas and rare gases belonging to Group 0 of the periodic table into at least a part of a fluororesin molded article. By irradiating an ultraviolet laser beam having a wavelength of 400 nm or less in a state in which either one of the aqueous solutions containing ions or a mixed solution of both are brought into contact with each other, the surface of at least one part of the fluororesin molded article is A hydrophilic fluororesin molded product that has been modified to be hydrophilic. 2. The hydrophilic fluororesin molded article according to claim 1, wherein the ultraviolet laser light having a wavelength of 400 nm or less is excimer laser light.