JPH075776B2 - Chemical plating method for fluoropolymer moldings - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical plating method for fluoropolymer moldings. More specifically, the present invention, by irradiating an ultraviolet laser beam in a system containing a gas of hydrazines, without making impurities such as residues on the polymer surface, to make the laser-irradiated surface hydrophilic and structural characteristics of the surface and The present invention relates to a novel chemical plating method for a fluoropolymer molded article, which has improved functionality and is then chemically plated to positionally and selectively deposit a metal film on the surface of the molded article.

[0002]

2. Description of the Related Art A polymer surface reaction using an excimer laser that oscillates high-intensity pulsed light in the ultraviolet region has been actively studied from the viewpoint of both basic and application as a precise surface treatment / processing method for polymers. ing. The inventors of the present invention have so far studied (1) the surface of a polymer by laser irradiation.
Formation of fine structure applicable to liquid crystal alignment film (H. Niino, A.
Yabe, et al., Japan Journal of Applied Physics, vo
l.28, p.L2225 (1989); Applied Physics Letters, vol.
55, p.510 (1989); Applied Physics Letters, vol.54,
p.2159 (1989); Applied Physics Letters, vol.57, p.2
368 (1990); Journal of Photochemistry. Photobiology
A: Chemistry, vol.65, p.303 (1992), and (2) Performing irradiation position-selective chemical plating by utilizing changes in surface potential (H. Niino, A. Yabe, et al. , Applied
Physics Letters, vol.60, p.2697 (1992)) was reported. These are based on periodic surface shape changes and generation of ionic species.

W. G. Hawkins a
nd PL Houston, Journal of Physical Chemistry, V
ol.86, p.704 (1982)), photochemical decomposition of hydrazine (N ₂ H ₄ ) by irradiation with argon fluorine (ArF) excimer laser (wavelength: 193 nm) was attempted in a gas phase, and NH ₂ and N were used as reaction intermediates. Radical species such as ₂ H ₃ and nitrene species such as NH are detected by spectroscopy. As described above, when an ultraviolet laser is used, gas molecules are decomposed by a photochemical reaction, and a reaction intermediate having high chemical reactivity can be efficiently generated. However,
They have not proposed any industrial utility or utilization of surface treatment methods using these reaction intermediates.

On the other hand, a fluorine-based polymer typified by polytetrafluoroethylene has a high thermal and chemical stability and is of wide industrial interest. However, since the surface free energy is very low, the surface shows water and oil repellency,
The surface adhesiveness is poor and the field of application is limited. Therefore, while maintaining the characteristics of the molded product itself,
In order to improve the surface adhesiveness, introduction of polar groups by various surface modification methods has been studied. For example, a method using plasma treatment (M. Morra, et al., Lang
muir, vol.5, p.872 (1989)), chemical activation method using alkali metal solution (ER Nelson, et al., Industr
ial and Engineering Chemistry, vol.50, p.329 (195
8)), and a method by laser irradiation using a boron-aluminum-ammonia compound (Toyota, Murahara, JP-A-2-196834). However, these methods have problems such as physical damage to the polymer surface, difficulty in local surface modification, and careful handling of reagents. Further, in these reports, no proposal has been made for depositing a metal film on the laser irradiation treated surface.

[0005]

DISCLOSURE OF THE INVENTION The present invention relates to an optical surface processing method for a fluorine-containing polymer molded article, and by using the excellent characteristics of the optical processing method by irradiation with an ultraviolet laser, a fluorine-based high surface processing energy with a low surface free energy is obtained. The purpose of the present invention is to deposit a metal film having excellent adhesion on the surface of the polymer by making the surface of the molecular molded article hydrophilic in a position-selective manner and then performing chemical plating. That is, an object of the present invention is to provide a more effective surface treatment method for a synthetic resin molded product.

[0006]

Means for Solving the Problems As a result of intensive studies on the surface processing method of a fluorine-containing polymer by ultraviolet laser irradiation, the present inventors have found that when an ultraviolet laser is irradiated in a system containing hydrazines, a high fluorine-containing polymer is obtained. It was found that the fluorine atom on the surface of the molecule can be replaced with an amino group to make only the laser-irradiated surface hydrophilic (Japanese Patent Application No. 4-356941). Further, by immersing the polymer in a stannous chloride / hydrochloric acid mixed aqueous solution and a palladium chloride aqueous solution for surface activation, and then in a chemical plating bath, laser irradiation of the surface of the fluoropolymer is performed. It was found that it is possible to selectively deposit a metal film with good adhesion only on the site. The present invention has been made based on these findings.

That is, according to the present invention, (1) a fluorine-based polymer molded article is exposed to ultraviolet laser light in the presence of hydrazines to hydrophilize the surface of the polymer molded article, and then chemical plating is carried out, A method for chemical plating of a fluorine-based polymer molded article, which comprises depositing a metal film on the surface of the polymer molded article, (2) a wavelength of 25 as an ultraviolet laser
The method according to item (1) is characterized in that an argon fluorine excimer laser of 0 nm or less or a krypton fluorine excimer laser is used.

Next, the present invention will be described in detail. The polymer molded article here means a material such as a film, a sheet, a fiber, a fiber reinforced resin and a resin molded article, and does not necessarily have to be a molded article as a final product, and its shape is not limited. Absent. As the hydrazines used in the present invention,
Examples thereof include hydrazine, hydrazine hydrate, phenylhydrazine and hydrazine hydrochloride. The reaction between the fluoropolymer molded product and hydrazines will be described by taking hydrazine as an example. Irradiation with an ultraviolet laser in a hydrazine atmosphere produces hydrazine in an electronically excited state, and then hydrazine in the electronically excited state is decomposed into a reaction intermediate such as a radical or nitrene. Since these reaction intermediates have high chemical reactivity, when a fluoropolymer molded product is present in the reaction system, substitution of the fluorine atom with the reaction intermediate on the carbon atom on the surface of the molded product is performed. The reaction occurs. Therefore, a polymer molecular chain having an amino group is generated on the surface of the molded article,
As a result, hydrophilization of the surface is observed. Further, since the life of the reaction intermediate is short, the substitution reaction occurs only on the surface portion irradiated with the laser beam, and the regioselective surface amination reaction is performed.

Polytetrafluoroethylene (PTF) irradiated with ArF excimer laser light in a system containing hydrazine
E) and the presence of substitution with amino groups on the surface of the tetrafluoroethylene / hexafluoropropylene copolymer (FEP) film indicate the appearance of nitrogen peaks and fluorine peaks in X-ray photoelectron spectroscopy (XPS) spectra. It was confirmed by the decrease of (Fig. 1 and Fig. 2). After the laser irradiation (FIG. 1), the nitrogen (N _1s ) peak appears and the fluorine (F _1s ) peak decreases compared to the carbon (C _1s ) peak before the laser irradiation (FIG. 2). Is shown. This means that the carbon atom to which the fluorine atom was bonded before the laser irradiation was replaced by the nitrogen atom, that is, the amino group. Further, the contact angle with water was 130 degrees before the treatment, but changed from 90 degrees to 30 degrees after the treatment, which revealed that the surface was hydrophilized. According to the above-mentioned ultraviolet laser irradiation, the surface of the fluoropolymer molded product can be easily and quickly made hydrophilic. Fluorine-based polymer molded products whose surface has been modified with amino groups
Since the surface free energy is large while maintaining the bulk properties, the surface adhesiveness is improved while maintaining the advantages of the fluoropolymer, or the range of application is further improved by the reaction between the amino group and other reagents. It is also possible to expand.

Next, the position-selective chemical plating process will be described. In order to activate the surface of the fluoropolymer molding that has undergone surface amination treatment, first stannous chloride-
Immerse in hydrochloric acid mixed aqueous solution. Since the aqueous solution is acidic, the amino groups on the surface of the molded product are ionized and ammonio groups (RN
H ₃ ⁺ ) and tin chloro complex ion (SnCl ₄ ²⁻ ) is immobilized on the surface by ionic bonding. Then, after washing with water, it is immersed in an aqueous solution of palladium chloride (PdCl ₂ ) and palladium ions adsorbed on the surface are reduced by tin complex ions to deposit a metal palladium colloid on the surface. After these surface activation steps, the molded product is immersed in a chemical plating bath containing the metal to be plated to deposit a metal film only on the laser irradiation site, using the metal palladium colloid on the surface as a catalyst site. You can In the present invention, nickel, copper, cobalt and gold are preferable as the metal used in the plating bath to form the metal film.

Further, the metal-plated film deposited on the laser-irradiated surface by the method described above has a luster and has good adhesion to the surface of the molded product. However, the metal film did not come off. Further, by utilizing the fact that the plated film has conductivity, general electrolytic plating can be performed to process the plated film into a more robust metal film. Further, in the present invention, the surface treatment is performed only on a desired irradiation portion by irradiating with a laser beam that has passed through a mask (a metal plate pattern or the like) corresponding to a portion to be modified on the surface of the polymer molded article. It is possible. On the other hand, ArF or Kr
The beam of the F excimer laser has a large beam shape as compared with the beams of other lasers such as a helium-neon laser, an argon and krypton ion laser, and an Nd ⁺ : YAG laser. By irradiating the area to be modified, it is possible to easily deal with large area processing. In particular, in the present invention, since hydrazines react by a non-thermal photochemical reaction by an ultraviolet laser, the peripheral portion other than the irradiation site is not accompanied by any thermal damage, and the surface treatment can be performed extremely effectively. it can.

As the laser in the present invention, an ultraviolet laser that oscillates the ultraviolet absorption wavelength of hydrazines is suitable, and an ArF excimer laser (wavelength: 193 nm) or a krypton fluorine (KrF) excimer laser (248 nm) is particularly preferable. Used. Also, N
d ⁺ : YAG, dye laser, Kr ion laser, A
An r-ion laser, a copper vapor laser, or the like can also be used by converting light having a fundamental wavelength into laser light in the ultraviolet light region of 250 nm or less using a non-linear optical element or the like. The laser fluence varies depending on the type of polymer or hydrazine, but a high intensity laser of about 1 mJ · pulse ⁻¹ or more is desirable when the pulse width is about nanosecond. In the present invention, the intensity of the ultraviolet laser light is preferably lower than the threshold intensity at which ablation occurs, for example, about 100 mJ · cm ⁻² ·
It is preferable that the intensity is less than or equal to pulse- ¹ . Further, it is effective that the gas pressure of hydrazines in the system for ultraviolet laser irradiation is high. The fluorine-based synthetic polymer molded article targeted in the present invention may be either an amorphous or crystalline aromatic or non-aromatic polymer, and examples thereof include polytetrafluorinated ethylene and polyhexafluoroethylene. It is a synthetic resin composed of any one of fluorinated propylene, polyfluorinated vinylidene, and polytrifluorinated ethylene chloride resin, a copolymer thereof, or a mixture thereof.

[0013]

The present invention will be described in more detail based on the following examples. Example 1 A polytetrafluoroethylene / polyhexafluoropropylene copolymer (FEP) film was set in a reaction vessel, and an ArF excimer laser was irradiated with 50 mJ · cm ⁻² · pulse- ¹ at room temperature and in a hydrazine atmosphere (9 Torr). 1,0 in strength
A surface treatment was performed by irradiating with 00 pulses. Due to the laser irradiation, the contact angle of the surface with water is 130 degrees to 30 degrees.
It was found that the surface was hydrophilized. In addition, a nitrogen (N _1s ) peak appeared after laser irradiation and a fluorine (F _1s ) peak decreased by X-ray photoelectron spectroscopy (XPS), indicating that an amino group was introduced on the surface after the treatment. Was confirmed (FIGS. 1 and 2). The surface-aminated FEP film is first immersed in a stannous chloride-hydrochloric acid mixed aqueous solution for a few seconds to 1 minute for surface activation, washed with water, and then dipped in a palladium chloride (PdCl ₂ ) aqueous solution for a few minutes. Soaked. When the FEP film was immersed in a nickel or copper chemical plating bath after these surface activation steps, a nickel or copper metal film could be deposited site-selectively only on the laser irradiation site. A peeling test using an adhesive tape (Mending Tape (M-18) manufactured by 3M USA) was performed on the generated metal plating film. As a result, it was found that the metal film did not peel off and the adhesion to the polymer surface was excellent.

[0014] Example 2 polyquaternary sets polytetrafluoroethylene (PTFE) film into the reaction vessel at room temperature, 50 mJ ArF excimer laser in hydrazine atmosphere (9Torr) · cm ^- 1 at an intensity of ² pulse ^-1, 000 pulses Irradiation and surface treatment were performed. It was found that the contact angle of the surface to water was reduced from 130 degrees to 90 degrees by the laser irradiation, and the surface was hydrophilized. PT subjected to the surface amination treatment
The FE film was first immersed in a stannous chloride-hydrochloric acid mixed aqueous solution for several seconds to 1 minute for surface activation, washed with water, and then immersed in an aqueous palladium chloride (PdCl ₂ ) solution for several minutes. When the PTFE film was immersed in a nickel or copper chemical plating bath after these surface activation steps, a nickel or copper metal film could be deposited site-selectively only on the laser irradiation site. A peeling test using the same adhesive tape as in Example 1 was performed on the generated metal plating film.
As a result, it was found that the metal film did not peel off and the adhesion to the polymer surface was excellent.

[0015]

EFFECTS OF THE INVENTION According to the present invention, by utilizing the fact that the irradiation of ultraviolet laser light is excellent in energy and position controllability, amino groups can be extremely effectively, precisely and uniformly applied to the surface of a fluoropolymer molding. Can be introduced to make the surface hydrophilic. Then, by performing a chemical plating after the surface activation treatment, the metal plating film can be deposited with good adhesion only on the pattern formation site by laser irradiation.

[Brief description of drawings]

FIG. 1 shows the FE after the tetrafluoroethylene / propylene hexafluoride copolymer (FEP) film was irradiated with ArF excimer laser in a hydrazine atmosphere in Example 1.
It is an X-ray photoelectron spectroscopy (XPS) spectrum of P film.

FIG. 2 is a graph showing F before being irradiated with laser in Example 1.
It is an XPS spectrum of EP film.

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Claims (2)

[Claims] 1. The surface of the polymer molded article is hydrophilized by irradiating a fluorine-based polymer molded article with an ultraviolet laser beam in the presence of hydrazines, and then chemical plating is performed to perform the chemical plating. A chemical plating method for a fluoropolymer molded article, which comprises depositing a metal film on the surface. 2. The method according to claim 1, wherein an argon fluorine excimer laser or a krypton fluorine excimer laser having a wavelength of 250 nm or less is used as the ultraviolet laser.