JP3338875B2 - Hydrophilic fluorinated resin molded product - Google Patents

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 article obtained by modifying a fluororesin molded article to be hydrophilic.

[0002]

2. Description of the Related Art In general, a molded article made of a fluorine-based resin has an inactive surface, and in some cases, lacks hydrophilicity or adhesiveness, and the actual use of the article is limited. For this reason, conventionally, the surface of a molded article made of a fluorine-based resin has been modified by a method of treating in an alkali metal solution, a method by plasma, a B (CH ₃ ) ₃ gas or a B ₂ H
F by excimer laser irradiation ₆ and NH ₃ and the surface of the fluorine-based film or the like which is placed in an atmosphere of mixed gas of
A method of modifying a group by substituting the group with a CH ₃ group or an NH ₂ group (JP-A-2-196834) and the like have 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 fluororesin surface. For example, in the method of treating in an alkali metal solution, there is a danger of ignition and instability of the treatment solution, and there is a problem that the modified portion is vulnerable to sunlight or high heat. In the plasma method,
There is a problem that the surface modification effect is significantly lower than that of a resin containing no fluorine such as polyethylene. Also, B
In the method of irradiating an excimer laser under an atmosphere of (CH ₃ ) ₃ or a mixed gas of B ₂ H ₆ and NH ₃ , not only is it costly to commercialize the apparatus used in the method, but also the toxicity is high. However, there is a problem that an operation requiring skill such as the use of a special gas having a high pressure and a decompression operation is required.

[0004]

Means for Solving the Problems The present inventors have conducted various studies to solve the above-mentioned problems, and as a result, have found that under specific conditions, an ultraviolet laser beam having a wavelength of 400 nm (nanometer) or less is used. It has been found that a hydrophilic fluororesin molded article can be easily obtained, and the present invention has finally been completed.

That is, the present invention provides a gas obtained by introducing at least one gas selected from a hydrogen gas, a nitrogen gas and a rare gas belonging to Group 0 of the periodic table into at least a part of a fluororesin molded article. Either the treated water or the aqueous solution containing ammonium ions, or a liquid mixture of both
(However, the aqueous solution containing ammonium ion is ammonia
When it is an aqueous solution, the ammonia aqueous solution is used alone.
Not used, but mixed with gas-treated water. )
A hydrophilic fluororesin molded article obtained by irradiating an ultraviolet laser beam having a wavelength of 400 nm or less in a state where the particles are in contact with each other, so that at least a part of the surface of the fluororesin molded article is modified to be hydrophilic. According to.

[0006] 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 oscillate 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 an F ₂ excimer laser (157 nm), a dye laser, a free electron laser and the like, and among them, an excimer laser is 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 (millijoules / square centimeter / pulse). The wavelength of such ultraviolet laser light is 400
nm or less, preferably 120 to 380 nm
It is about. If the wavelength of the ultraviolet laser light exceeds 400 nm, there is a disadvantage that the ultraviolet laser light is difficult to be modified into hydrophilic.

In order 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, etc. derived from the fluororesin on the surface of the molded article. ,
It is presumed that it is desirable to cleave the CF bond at least partially, but there are some aspects that are not certain. As the conditions, the absorption of the oscillation wavelength of the 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 the above-mentioned value of the fluororesin. Desirably, it is larger than the binding energy of the bond. However, this is not particularly limited. For example, in the case of an ultraviolet laser beam in which the energy of one photon is smaller than the binding energy, it is presumed that cutting can be performed by causing multiphoton absorption, but it is uncertain. It is.

For example, when the above-mentioned bond of the fluorine-based resin is cut while satisfying the above conditions, when using the gas-treated water into which the specific gas according to the present invention is introduced, the portion is caused by the gas-treated water. H, OH, COOH, CO groups, etc. are presumed to be modified to be hydrophilic, but it is unknown that it is certain, and the aqueous solution containing ammonium ions according to the present invention is used. At that time, the part is caused by the aqueous solution according to the present invention, such as NH ₂ group, H group, OH group, CO 2
It is presumed that it is substituted with OH group, CO group, etc. to be modified to be hydrophilic, but it is unknown that it is certain.

In the case of using the gas-treated water according to the present invention into which the specific gas is introduced, the cut and separated F is removed by combining with H caused by the gas-treated water into which the specific gas is introduced. It is presumed that it is, but it is unknown. Further, the ultraviolet laser light activates both the gas-treated water and the surface of the fluorine-containing resin molded product, and in particular, the gas acts as an energy transfer agent to activate, thereby generating a polar group on the surface of the molded product. However, it is estimated that the effect appears, but it is not clear that this is true.

Further, when the aqueous solution containing ammonium ions according to the present invention is used, it is presumed that the F which has been cleaved and released binds to H caused by the aqueous solution and is removed,
At this time, as a reason for the binding, for example, the binding energy of HF is 135 Kcal / mol, which is larger than the binding energy of CF of 129 Kcal / mol.
It is presumed that it binds more easily than F, stabilizes in this state, and does not release F again, but it is unclear.

Although all of the above has been presumed, it is expected that these will be clarified in future studies.

The 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, at least one of these rare gases, hydrogen gas and nitrogen gas is used, that is,
A mixture of more than one species can be used.

Various methods are conceivable for preparing gas-treated water by introducing such a gas, and there is no particular limitation. Usually, the water is prepared by contacting the gas with various waters described below. . In contacting the gas, 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 how the gas phase is brought into contact. By contacting in this way, the gas is dissolved in water or exists in the form of fine bubbles in water.
However, in the gas-treated water provided with the gas phase on the water surface, it is unknown whether the gas is dissolved in water or exists in the form of bubbles in the water. Since the desired effect is exhibited, such gas-treated water is also within the scope of the present invention. As described above, in the present invention, the gas does not necessarily need to be dissolved in water or exist as bubbles in water. The amount of such a gas in water is not particularly limited, but may be about 10 ^-2 to 10 ^-5 % by weight when dissolved in water.

The aqueous solution containing ammonium ions used in the present invention refers to an aqueous solution containing a compound which produces ammonium ions (NH ₄ ⁺ ) when 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. Examples thereof include organic carboxylate 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 the above-mentioned compounds that form ammonium ions in a state of being dissolved in water. In the present invention, at least one of such compounds can be used, that is, one type can be used alone, or two or more types can be used in combination. The amount of such a compound is not particularly limited, but it is generally preferable to add it so that it is contained in an aqueous solution at 10% by weight or less, preferably about 0.001 to 10% by weight.

According to the present invention, there is provided a method for producing a liquid-treated resin comprising at least one part of the above-mentioned specific gas and at least one part of the above-mentioned gas-treated water and the above-mentioned aqueous solution containing ammonium ions, or a liquid mixture of both. It is necessary to make contact. At this time, the mixture of both may be prepared by previously preparing an aqueous solution containing the ammonium ion and the gas-treated water, and then mixing the two,
A specific gas may be introduced into an aqueous solution containing ammonium ions to form a mixed state, or conversely, a compound that produces the above-mentioned ammonium ions may be added to gas-treated water to form a mixed state. The mixture may be mixed at the same time, and there is no particular limitation on the method of preparing the mixture. Further, it goes without saying that both liquids may be separately brought into contact with each other in two steps.

If necessary, it is possible to add various third components to the aqueous solution or the gas-treated water containing such ammonium ions. Specific examples of the 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 preparing the liquid used in the present invention (hereinafter referred to simply as "liquid", a liquid mixture is also included), the water used is not particularly limited, and natural water, industrial water,
Examples include tap water, distilled water, pure water, ion-exchanged water, and other appropriate water. 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 and the aqueous solution, the water is not limited to the above-mentioned water, and 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 not particularly limited. However, such aqueous solutions of 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.

With respect to the above-mentioned water, ordinary natural water, industrial water, tap water and the like sometimes contain a trace 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 or the gas-treated water into which a specific gas is introduced in the present invention.

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

In order to bring the fluororesin molded article into contact with the liquid of the present invention, the liquid may be brought into contact with at least a part of the molded article, that is, partially or entirely. The method of contact is not particularly limited, and examples thereof include a method of immersing the molded product in a liquid, a method of placing the molded product on a liquid surface, and a method of spraying a liquid on the surface of the molded product with a spray or the like. Can be mentioned.

The fluororesin molded article according to the present invention is obtained by modifying at least one part of its surface, that is, one part or the whole surface to be hydrophilic. In order to modify a part of the surface of the molded article, the liquid of the present invention may be partially brought into contact with the surface of the molded article, or the liquid may be brought into contact with the entire surface of the molded article, Ultraviolet laser light may be partially irradiated, and there is no particular limitation. There is no particular limitation on the entire surface of the molded product to be modified to be hydrophilic.For example, the molded product is immersed in a liquid as described above, or the molded product is placed on a liquid surface, A liquid may be sprayed on the surface of the molded product by spraying or the like, 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 the ultraviolet laser, irradiation conditions, and the like. However, as a rough guide, the incident energy (irradiation amount) is about 1 to 3000 J / cm ² ( Joule / square centimeter).

Irradiation of the ultraviolet ray to the fluororesin molded article is not particularly limited, but it is preferable to wash the molded article with various cleaning agents such as alcohol prior to irradiation. By washing with a detergent, oil and dirt adhered to the surface of the fluororesin molded product during the molding process or the like can be removed, and a product with high commercial value can be obtained. The alcohol or the like is not particularly limited, but is preferably an alcohol having a low boiling point so as not to adversely affect the reforming.

The fluororesin used as the raw material of the fluororesin molded article treated in the present invention is not particularly limited.
Tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), ethylene-tetrafluoroethylene copolymer (ETFE), Examples include a fluorosilicone polymer synthesized from fluorocarbon and an organic silicone, and a mixture thereof. An appropriate third component such as a synthetic resin or a filler may be added to such a fluororesin within a range that does not significantly modify the properties of the fluororesin.

Examples of the fluororesin molded article in the present invention include, specifically, films, sheets, tubes, sleeves, tapes, filaments, knits, woven fabrics, strings, rods, powders and the like made of fluororesin. However, the present invention is not limited thereto, and includes all fluorine-based resin molded products.
Such a fluororesin molded article further includes a composite molded article with another synthetic resin or the like, or a fluororesin molded article such as a composite molded article with a natural fiber, a chemical fiber, a synthetic fiber, or the like. , Etc., are all included.

When a film is used as a fluororesin molded article, the thickness of the film is not particularly limited. For example, when the film is placed on the liquid, the thickness can be about 1 mm or less. There is also an advantage that the ultraviolet laser beam transmits 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. Particularly, when used as an artificial blood vessel, an artificial blood vessel having excellent antithrombotic properties can be obtained. Further, since there is no discoloration due to the modification, it can be used for a material such as a contact lens, for example, and can also be used as one of composite materials by bonding with a molded product made of another material, combining, and the like. Further, in addition to these, a wide range of applications can be expected in all fields, and there is no particular limitation on the applications.

[0028]

EXAMPLES Next, the present invention will be further clarified with reference to examples, but the present invention is not limited to these examples.
The following embodiment will be described with reference to FIG. 1 which shows a schematic view of an excimer laser irradiation apparatus which is one kind of ultraviolet laser. The contact angle with water is defined as Kyowa Interface Science Co., Ltd.
When a water drop was dropped using a CA-A type measuring instrument manufactured by
This is a measured value of the contact angle after 0 seconds, and 3
The average value was obtained by measuring twice.

Example 1 A stainless steel reaction cell [5] (a petri dish may be used)
Gas-treated water into which nitrogen gas has been blown into distilled water for 10 minutes, and a film (thickness: 100 μm, light transmittance: 7%) [7] made of PFA resin is brought into contact with the aqueous solution [6] (the aqueous solution). Ar was formed through a metal mask [3].
F excimer laser (wavelength 193 nm) light [1] was focused by a convex lens [4] and irradiated perpendicularly to the film surface.
The irradiation condition at this time was a laser fluence of 13 mJ / c.
m ² / pulse, the number of shots was 16,000, 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 °, and has a superior hydrophilicity on the film surface as compared with the contact angle of 106 ° of the unirradiated film. Indicated.

Example 2 Instead of the gas-treated water [6] of Example 1, gas-treated water in which hydrogen gas was blown into distilled water for 10 minutes was used, and a film made of PFA resin (thickness: 100 μm) was used in the aqueous solution.
[7] was brought into contact (contact was made by placing it in water 5 mm below the surface of the aqueous solution), and the same ArF excimer laser light [1] as in Example 1 was converged by a convex lens [4] to be perpendicular to the film surface. Irradiated. Irradiation conditions were as follows: laser fluence 13 mJ / cm ² / pulse, number of shots 16,000
Shot and frequency were 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 in which helium gas was blown into distilled water for 10 minutes was used, and a film made of PFA resin (100 μm thick) was added to the mixed solution.
m) [7] is brought into contact as in Example 1, and the same ArF excimer laser beam [1] as in Example 1 is used as a convex lens [4].
And irradiated vertically to the film surface. Irradiation conditions are laser fluence 13 mJ / cm ² / pulss
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 exhibited excellent hydrophilicity.

Example 4 A film made of PFA resin (100 μm thick) was placed in distilled water in which gaseous argon was blown for 10 minutes.
m) [7] is brought into contact as in Example 1, and the same ArF excimer laser beam [1] as in Example 1 is used as a convex lens [4].
And irradiated vertically to the film surface. Irradiation conditions are laser fluence 13 mJ / cm ² / pulss
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 markedly increased hydrophilicity as compared with the untreated film, and had a contact angle of 34 degrees.

Example 5 A film (100 μm thick) made of a PFA resin was placed in gas-treated water in which xenon gas was blown into distilled water for 10 minutes.
m) [7] is brought into contact as in Example 1, and the same ArF excimer laser beam [1] as in Example 1 is used as a convex lens [4].
And irradiated vertically to the film surface. Irradiation conditions are laser fluence 13 mJ / cm ² / pulss
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 °, and the film surface showed excellent hydrophilicity.

Example 6 Reaction cell [5] made of stainless steel (a petri dish may be used)
Then, an aqueous solution of ammonium having a concentration of 0.01% by weight is put into the aqueous solution [6], and a film (thickness: 100 μm, light transmittance: 7%) [7] made of PFA resin is brought into contact with the aqueous solution [6] (the surface of the aqueous solution). The surface on the front side of the film was not in direct contact with the aqueous solution.)
Next, ArF excimer laser (wavelength 193 nm) light [1] formed through a metal mask [3] was focused by a convex lens [4] and irradiated perpendicularly to the film surface. The irradiation condition at this time was a laser fluence of 13 mJ / cm ²
/ Pulse, the number of shots was 16,000, 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 showed excellent hydrophilicity.

[0041]

[0042]

Example 7 A 0.01% by weight ammonium carbonate aqueous solution was used in place of the aqueous solution [6] of Example 6, and a film (100 μm thick) made of PFA resin [7] was used in the mixed solution. 6
And the same ArF excimer laser beam [1] as in Example 6 was focused by a convex lens [4] and irradiated perpendicularly to the film surface. Irradiation conditions were as follows: laser fluence 13 mJ / cm ² / pulse, number of shots 16,000
Shot and frequency were 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 showed excellent hydrophilicity.

Comparative Example P was added to each of a nitrogen gas atmosphere and a helium gas atmosphere.
A film made of FA resin (thickness: 100 μm) [7] was placed, and an ArF excimer laser beam [1] was vertically irradiated on the film surface. Irradiation conditions are laser fluence 1
3 mJ / cm ² / pulse, the number of shots was 16,000, and the frequency was 50 Hz.

The film [7] made of the PFA resin treated in any atmosphere was compared with the untreated film.
The surface became wavy and the appearance was impaired. In addition, there was no significant 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, a simple device can be used by using a liquid which 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, a fluororesin molded article having excellent hydrophilicity can be obtained by a simple operation. The hydrophilicity imparted in the present invention is extremely excellent, and the hydrophilicity is not likely to be altered by sunlight or heat. The hydrophilic fluorine-based resin molded product of the present invention, for example, including artificial blood vessels having excellent antithrombotic properties, various artificial organs, and is suitable as a material for contact lenses and the like because there is no discoloration due to modification, 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 superior functionality.

[Brief description of the drawings]

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

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 excimer laser beam 2 mirror 3 mask 4 lens 5 reaction cell 6 liquid 7 fluorinated resin molded product (film) 8 XY-stage 9 excimer laser oscillator

──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yuichi Shimizu 25-1 Mitsumi-machi, Neyagawa-shi, Osaka Japan Atomic Energy Research Institute, Takasaki Research Laboratory Osaka Branch (72) Inventor Shunichi Kawanishi 25-1, Mitsumi-cho, Neyagawa-shi, Osaka No. Japan Atomic Energy Research Institute Takasaki Research Institute Osaka Branch (72) Inventor Masanobu Nishi 25-1 Mitsui Minamimachi, Neyagawa City, Osaka Prefecture Japan Atomic Energy Research Institute Takasaki Research Institute Osaka Branch (72) Inventor Shunichi Sugimoto Mitsui, Neyagawa City, Osaka Prefecture 25-1, Minamimachi Japan Atomic Energy Research Institute Takasaki Research Institute Osaka Branch Office of Radiation Irradiation Promotion Association (56) References JP-A-6-279590 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB Name) C08J 7/00-7/18

Claims (2)

(57) [Claims] 1. Gas-treated water obtained by introducing at least one 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, and ammonium gas. Either one of the aqueous solutions containing ions or a mixture of both (however, ammonia
When the aqueous solution containing umium ions is an aqueous ammonia solution
In this case, the aqueous ammonia solution is not used
It shall be used by mixing with water. ) Is irradiated with an ultraviolet laser beam having a wavelength of 400 nm or less in a state in which the surface of at least one part of the fluororesin molded article is modified to be hydrophilic to form a hydrophilic fluororesin. Goods. 2. The hydrophilic fluororesin molded article according to claim 1, wherein the ultraviolet laser light having a wavelength of 400 nm or less is an excimer laser light.