JP2016024998A - Mercury lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a mercury lamp capable of remarkably reducing an irradiation time of ultraviolet rays for modifying the surface of a synthetic resin in forming an electroless plating layer.SOLUTION: In a mercury lamp, the vapor pressure of mercury in stable lighting is 1-10 atm, and the content of impurities of silica glass constituting a straight tube type luminous tube 11 is set not to exceed the following numerical values. (A) aluminum (Al): 0.05 ppm, (B) sodium (Na): 0.02 ppm, (C) lithium (Li) and copper (Cu): 0.01 ppm, (D) potassium (K), magnesium (Ma), iron (Fe) and calcium (Ca): 0.05 ppm, (E) OH group: 300 ppm, and (F) other impurities: 0.1 ppm. In addition, the irradiation intensities of ultraviolet rays with a wavelength of 185 nm and a wavelength of 254 nm at an irradiation distance of 150 nm are at least 6.5 mw/cmand 130 mw/cm, respectively.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a mercury lamp, and more particularly to a mercury lamp used for modifying the surface of a synthetic resin forming an electroless plating layer.

  Conventionally, means for producing an electronic circuit component, a decorative article, etc. by forming an electroless plating layer on the surface of a synthetic resin has been widely used. However, when the electroless plating layer is formed on the surface of the synthetic resin, it is necessary to sufficiently secure the adhesion of the electroless plating layer to the surface of the synthetic resin.

  As means for ensuring the adhesion of the electroless plating layer to the surface of the synthetic resin, means for roughening the surface of the synthetic resin by chemical etching or laser light irradiation is widely used. . That is, if the surface of the synthetic resin is roughened to form minute irregularities, electroless plating is deposited in the irregularities and strongly adheres to the surface of the synthetic resin by a so-called anchor effect.

  Nowadays, demands for smaller, lighter, higher speed and higher performance of electronic devices are increasing, and along with this, miniaturization and higher integration of electronic circuits and higher frequency of transmission signals are progressing. . However, the higher the transmitted signal is, the more concentrated the transmitted signal is on the surface of the circuit. Therefore, when the surface of the synthetic resin is roughened, the contact surface with the roughened surface of the electroless plating layer formed on the roughened surface also becomes rough, which increases the conductor loss of high-frequency transmission signals. Occurs.

  Also, when creating decorative items by applying electroless plating to the surface of synthetic resin parts, if the surface of the synthetic resin parts is roughened to ensure adhesion, Since unevenness is also generated on the surface, decoration is required to smooth the upper surface.

  Furthermore, when an electroless plating layer is laminated on the surface of a synthetic resin component to form a light reflector such as an LED lamp, if the upper surface of the electroless plating layer is uneven, the light reflection efficiency decreases. The problem arises.

  Therefore, the present inventors modify the surface of the synthetic resin by irradiating the surface of the synthetic resin with ultraviolet rays in an aerobic atmosphere, thereby maintaining the smoothness of the surface of the electroless plating layer in contact with the surface of the synthetic resin. However, a means for ensuring the adhesion of the electroless plating layer has been proposed (see Patent Document 1). In this means, ultraviolet irradiation uses a low-pressure mercury lamp that irradiates strong ultraviolet rays having wavelengths of 185 nm and 254 nm.

  The mechanism of modifying the surface of the synthetic resin by irradiation with ultraviolet rays and maintaining the adhesion of the electroless plating layer while maintaining the smoothness of the surface of the electroless plating layer is considered as follows. That is, when the synthetic resin is irradiated with ultraviolet light having a wavelength of 185 nm, the high molecular bond of the synthetic resin is cut to generate a low molecule. Ultraviolet light having a wavelength of 185 nm is absorbed by oxygen molecules in the air, dissociates oxygen molecules to generate oxygen atoms, and these oxygen atoms combine with oxygen molecules to generate ozone molecules. On the other hand, ultraviolet light having a wavelength of 254 nm is absorbed by the generated ozone molecules and decomposes the ozone molecules to generate active oxygen atoms.

  The generated active oxygen atom reacts with the low molecule produced by breaking the bonds of the polymer constituting the synthetic resin to modify the surface of the synthetic resin, thereby changing the hydrophilic —OH group and —COO group. Form. The surface of the modified synthetic resin is slightly roughened to a diameter of 0.1 to 20 μm and a depth of about 0.1 to 5 μm.

  The plating metal of the electroless plating layer is easy to chemically bond with the —OH group or —COO group of the modified layer, and the adhesion with the synthetic resin is improved. Further, since the surface of the synthetic resin is slightly roughened, the adhesion with the synthetic resin is further improved by the microscopic anchor effect. Therefore, the adhesion of the electroless plating layer is maintained while maintaining the smoothness of the surface of the electroless plating layer in contact with the surface of the synthetic resin by the chemical bond with the surface-modified synthetic resin and the microscopic anchor effect. Sex can be secured.

Japanese Patent No. 4738308

  In the above-mentioned means, the irradiation time of ultraviolet rays from the low-pressure mercury lamp, that is, the irradiation time until the surface of the synthetic resin is sufficiently modified to ensure sufficient adhesion of the electroless plating layer is, for example, about aramid resin (nylon) Requires a long time of 20 minutes or more. For this reason, in order to improve productivity, such long-time ultraviolet irradiation is a big bottleneck.

  Therefore, it is strongly desired to shorten the irradiation time until the surface of the synthetic resin is modified to such an extent that sufficient adhesion of the electroless plating layer is ensured.

  Therefore, an object of the present invention is to modify the surface of the synthetic resin by irradiation of ultraviolet rays, and to irradiate ultraviolet rays in a means for ensuring the adhesion of the electroless plating layer while maintaining the smoothness of the surface of the electroless plating layer. The object is to provide a mercury lamp which can greatly reduce the time.

  Mercury lamps are provided with electrodes at both ends of an arc tube sealed with a rare gas such as argon and mercury, and a voltage is applied to the electrodes to generate an arc discharge. The arc discharge causes electrons that travel around each orbit of the mercury atom. It uses ultraviolet light or visible light emitted when excited to make a transition to a higher orbit and this electron returns to a lower orbit, and this ultraviolet or the like has a wavelength peculiar to mercury atoms.

  The mercury lamp for irradiating ultraviolet rays includes the above-described low-pressure mercury lamp having a main wavelength of 185 nm and 254 nm, a high-pressure mercury lamp having a main wavelength of 365 nm used for curing and drying ink, paint and adhesive, or a semiconductor, There are ultra-high pressure mercury lamps used in photoetching and exposure of ICs, exposure, projectors and the like.

  By the way, the mercury lamp emits ultraviolet rays having a long wavelength (UV-A) of 320 nm or more when the pressure of mercury (vapor) during lighting is high, and a wavelength of 320 nm or less (UV-B) when the pressure of mercury (vapor) is low. , UV-C).

The glass constituting the arc tube of the mercury lamp is made of quartz glass which has a low impurity content, is transparent and has high heat resistance. In addition to fused silica glass made from natural quartz, quartz glass includes synthetic quartz glass made from silicon tetrachloride (SiCl ₄ ) or the like and containing as little impurities as possible.

  However, the quartz glass constituting the arc tube can transmit more ultraviolet rays (UV-C) having a short wavelength of 280 nm or less as the amount of impurities decreases. That is, the shorter the wavelength of the ultraviolet light, the more easily the transmission is hindered by impurities. Therefore, if even a small amount of impurities is contained in the quartz glass constituting the arc tube, the transmittance of ultraviolet rays having a short wavelength is lowered. For this reason, low-pressure mercury lamps using short wavelengths of 185 nm and 254 nm use synthetic quartz glass with a very low impurity content and fused silica glass with a low impurity content depending on the application.

  On the other hand, ultraviolet rays having a relatively long wavelength and approximately 320 nm or more are not easily affected by impurities, and the transmittance does not decrease. That is, for ultraviolet rays and visible rays having a wavelength of about 320 nm or more, there is almost no difference in transmittance between fused silica glass and synthetic quartz glass. For this reason, the arc tube of a high-pressure mercury lamp that exclusively uses ultraviolet light or visible light having a wavelength of 365 nm has a higher impurity content than synthetic quartz glass, but inexpensive fused silica glass is used.

  The inventor of the present application has repeated trial and error in order to shorten the irradiation time of ultraviolet rays until the surface of the synthetic resin is modified to an extent that ensures sufficient adhesion of the electroless plating layer. The present invention has been completed by finding that a shortening effect far exceeding expectations can be obtained by replacing the lamp with the mercury lamp according to the present invention.

That is, the mercury lamp according to the present invention is a mercury lamp used for modifying the surface of the synthetic resin forming the electroless plating layer, and this mercury lamp is made of a straight tube type quartz glass having electrodes at both ends. It has an arc tube. The arc tube is filled with mercury in an amount such that the vapor pressure during stable lighting is 1 to 10 atm. The quartz glass constituting the arc tube has the following contents of impurities (A) to (F): be those not exceeding numeric wavelength the intensity of ultraviolet rays 185nm and 254 nm, the irradiation distance 150 mm, characterized in that each of at least 6.5 mW / cm ² and 130 mW / cm ^2.

(A) Aluminum (Al): 0.05 ppm
(B) Sodium (Na): 0.02 ppm
(C) Lithium (Li) and copper (Cu): 0.01 ppm
(D) potassium (K), magnesium (Ma), iron (Fe) and
Calcium (Ca): 0.005 ppm
(E) OH group: 300 ppm
(F) Other impurities: 0.1 ppm
Here, the “electroless plating layer” is a metal layer formed by so-called chemical plating, and may have any shape. For example, in addition to those formed selectively only on a part of the surface of the synthetic resin such as an electronic circuit, those formed over the entire surface of the surface of the synthetic resin such as an ornament are included. Moreover, as a metal of an electroless-plating layer, these alloys other than single metals, such as copper, nickel, gold | metal | money, and silver, are also included. It also includes the case of laminating electroless plating layers of different metals. The electroless plating layer is formed by using a commonly used electroless plating means.

  Examples of the “synthetic resin” include ABS resin, cycloolefin polymer, liquid crystal polymer, polyimide, polycarbonate and the like. The shape of the “synthetic resin” is not particularly limited. A sheet-like material such as a film, a plate-like material such as a printed circuit board, or a three-dimensional shape (molded product) such as a fastener is applicable.

  “Modifying the surface” is a modification for ensuring the adhesion of the electroless plating layer while maintaining the smoothness of the surface of the electroless plating layer in contact with the surface of the synthetic resin, Means equivalent to the modifications described in "0008" to "0009". “Mercury lamps” are electrodes that are provided at both ends of an arc tube filled with mercury together with a small amount of rare gas, and a voltage is applied to the electrodes to generate an arc discharge. Is used to make a transition to a higher orbit and use ultraviolet rays or visible light emitted when the electrons return to a lower orbit. Further, “(F) other” corresponds to phosphorus (P), titanium (Ti), boron (B), and the like.

"Irradiation intensity of ultraviolet light having a wavelength of 185nm and 254nm is in the irradiation distance 150 mm, respectively is at least 6.5 mW / cm ² and 130 mW / cm ^2" in, had a "UV wavelength 185nm and 254nm" are This is because, as described above, in order to modify the surface of the synthetic resin that forms the electroless plating layer, it is considered that ultraviolet rays having these wavelengths act effectively.

  The “irradiation intensity” means the intensity of ultraviolet rays per unit area measured at the “irradiation distance” described below. That is, it means the intensity of ultraviolet rays per unit area on the surface of the synthetic resin at a predetermined distance from the mercury lamp. “Irradiation distance” means the distance from the center line of the arc tube of the mercury lamp to the position where the intensity of ultraviolet rays per unit area is measured. Here, the reason “when the irradiation distance is 150 mm” is that if the irradiation distance is shorter than 150 mm, the influence of heat on the synthetic resin that irradiates ultraviolet rays becomes large, and there is a risk of deformation or alteration.

“Irradiation intensity is at least 6.5 mw / cm ² and 130 mw / cm ² , respectively” means that, as will be described later, at least the irradiation intensity in the test confirming the significant shortening effect of the irradiation time. This is for the purpose of the present invention. Incidentally, "the irradiation distance is 150mm", "irradiation intensity is at least 6.5mw a / cm ² and 130 mW / cm ^2, respectively," and, exert equivalent effects as significant reduction effect of irradiation time was confirmed by the test For this purpose, it is meant to define the minimum irradiation capacity required for the mercury lamp according to the present invention for ultraviolet rays with wavelengths of 185 nm and 254 nm.

That is, the irradiation intensity may be larger than 6.5 mw / cm ² and 130 mw / cm ^{2 at} an irradiation distance of 150 mm. In such a case, at the position where the irradiation distance is longer than 150 mm (150 mm + α), 6.5 mw / cm ^2. Irradiation intensities of cm ² and 130 mw / cm ² are obtained. Therefore, in such a case, if the irradiation distance is in the range of 150 mm to 150 mm + α, the effect of greatly shortening the irradiation time confirmed by the test can be expected. Note irradiation intensity of ultraviolet light having a wavelength of 185nm and 254nm illuminated distance in 150mm is more desirably 8 mW / cm ² and 160 mW / cm ^2, respectively, each 10 mw / cm ² and 200 mw / cm ² is more preferable.

  As will be described later, when the mercury lamp according to the present invention is used, the irradiation time of the ultraviolet rays until the surface of the synthetic resin is modified to such an extent that the adhesion of the electroless plating layer is sufficiently secured is surprisingly low. Depending on the technology, that is, when using the current low-pressure mercury lamp, it can be shortened to 1/4 (20 minutes for aramid resin is 5 minutes) to 1/3 (6 minutes for liquid crystal polymer is 2 minutes). . Such a significant reduction in irradiation time was far beyond expectations.

  As will be described later, when the spectrum of ultraviolet rays irradiated by the mercury lamp according to the present invention and the current low-pressure mercury lamp is compared, it has been found that the irradiation intensity of ultraviolet rays greatly increases at wavelengths of 185 nm and 254 nm. The effect of shortening the irradiation time is considered to be due to an increase in the irradiation intensity of such short wavelength ultraviolet rays. The increase in the irradiation intensity of the short wavelength ultraviolet rays is due to the fact that the transmittance of the short wavelength ultraviolet rays is increased by limiting the content of impurities in the quartz glass constituting the arc tube to an extremely small amount.

1 is an overall view of a mercury lamp according to the present invention. It is process drawing which shows the usage example of the mercury lamp by this invention. It is the graph which compared the irradiation time of the mercury lamp by this invention with respect to a polyamide resin, and the low pressure mercury lamp by a prior art. It is the graph which compared the irradiation time of the mercury lamp by this invention with respect to a liquid crystal polymer, and the low pressure mercury lamp by a prior art. It is a comparison figure of the irradiation intensity | strength of the ultraviolet rays with a wavelength of 185 nm, 254 nm, and 351 nm which the mercury lamp by this invention and the low-pressure mercury lamp in use respectively irradiate.

  First, a mercury lamp according to the present invention will be described, and then a process of forming an electroless plating layer on the surface of the synthetic resin using the mercury lamp will be described. As shown in FIG. 1, a mercury lamp 1 according to the present invention includes an arc tube 11 made of straight tube quartz glass, and ceramic bases 12 and 13 provided on both outer ends of the arc tube. Yes. Tungsten electrodes 14 and 15 are provided at both inner ends of the arc tube 11 at a distance of 250 mm from each other. The arc tube has a length of about 270 mm and an outer diameter of 24 mm.

  Inside the arc tube 11, mercury is enclosed as a main luminescent substance, and a small amount of rare gas (argon, xenon, etc.) is enclosed as a starting gas, and the vapor pressure of mercury during stable lighting is 1 to 10 atmospheres (absolute pressure). Moreover, the quartz glass which comprises the arc_tube | light_emitting_tube 11 uses what the content of the impurity does not exceed the following numerical value.

(A) Aluminum (Al): 0.05 ppm
(B) Sodium (Na): 0.02 ppm
(C) Lithium (Li) and copper (Cu): 0.01 ppm
(D) potassium (K), magnesium (Ma), iron (Fe) and
Calcium (Ca): 0.05ppm
(E) OH group: 300 ppm
(F) Other impurities: 0.1 ppm
In addition, the quartz glass which comprises the arc_tube | light_emitting_tube 11 is manufactured by the structure and manufacturing method equivalent to the well-known synthetic quartz glass used for the low pressure mercury lamp except the content of the said impurity. For example, it is manufactured by a gas phase synthesis method (plasma method or stoe remelting method) using silicon tetrachloride (SiCl ₄ ) as a raw material, or a sol-gel method (liquid phase method) using alkyl silicate as a raw material. Further, in the mercury lamp 1 described above, other configurations are the same as those of a known high-pressure or medium-pressure mercury lamp.

The mercury lamp 1, the irradiation intensity of ultraviolet light having a wavelength of 185nm and 254nm is in the irradiation distance 150 mm, configured to irradiate the ultraviolet rays is at least 6.5 mW / cm ² and 130 mW / cm ^2, respectively. For example, a lamp voltage of 340 V is applied between the electrodes 14 and 15 by a ballast (not shown) fed from an external power source of 200 V to generate a lamp output of 3000 W.

  The total length, tube diameter, and interelectrode distance of the arc tube 11 of the mercury lamp 1 can be selected in the range of 150 to 2350 mm, 17.5 to 25 mm, and 50 to 2250 mm, respectively. The lamp voltage and lamp output of the arc tube 11 are determined by the total length and tube diameter of the arc tube 11, the distance between the electrodes, and the amount of mercury to be sealed, and are selected in the range of 130 to 1750V and 400 to 20000W, respectively. Can do.

  FIG. 2 shows an example of a process for forming an electroless plating layer on the surface of a synthetic resin using the mercury lamp 1 according to the present invention. In the step (A), an aromatic polyamide (nylon) (for example, Kuraray's product “Genesta TA112”) is injection-molded to form the block-shaped substrate 2.

  Next, in a second step (FIG. B), the non-circuit portion 22 of the substrate 2 is covered with a mask 3 made of a material that does not allow ultraviolet light to pass through. The mask 3 has a portion corresponding to the portion 21 serving as a circuit cut out. And using the mercury lamp 1 mentioned above, the part 21 used as the circuit which is not covered with the mask 3 is irradiated with an ultraviolet-ray, and the surface of the part used as this circuit is modified. The ultraviolet ray from the mercury lamp 1 is irradiated for about 5 minutes at an output of 3000 W and an irradiation distance of 290 mm to the substrate 2.

  Next, although not shown in the drawing, the substrate 2 is washed with an alkali and further surface-adjusted so that the catalyst can be easily adsorbed to the portion 21 which becomes the surface-modified circuit. Here, the alkali cleaning is performed, for example, by immersing the substrate 2 in an aqueous solution of sodium hydroxide having a temperature of 50 ° C. and a concentration of 50 g / liter for 5 minutes. The surface adjustment is performed, for example, by immersing the substrate 1 in an aqueous solution in which a surfactant (for example, product “PB-119S” manufactured by JCU Corporation) is diluted to 50 cc / liter and the temperature is set to 25 ° C. for 5 minutes.

  In the next step (C), a palladium ion catalyst (not shown) (for example, product “# ACT-S” manufactured by JCU Co., Ltd.) is ionized at a concentration of 50 ppm with an aqueous solution of hydrochloric acid having a concentration of 0.06% (pH 2.0). The activated substrate 2 is immersed in an ion catalyst solution diluted to a concentration and the temperature is set to 25 ° C. for 2 minutes, and the palladium ion catalyst is adsorbed to the portion 21 that forms the surface-modified circuit.

  The portion 21 that becomes the circuit irradiated with ultraviolet rays has been surface-modified as described above to generate hydrophilic —OH groups and —COO groups, so that the palladium ion catalyst enters the modified layer. It reacts with these hydrophilic groups and is firmly fixed in the modified layer. However, the palladium ion catalyst is not adsorbed to the non-circuit portion 22 that is not surface-modified because it is not irradiated with ultraviolet rays.

  Next, in step (D), the base 2 is immersed in an aqueous solution of sodium borohydride having a temperature of 25 ° C. and a concentration of 1.5 g / liter, and the adsorbed palladium ion catalyst is reduced to palladium metal. Since the palladium ion catalyst is firmly fixed in the modified layer that has been surface-modified by irradiation with ultraviolet rays, the reduced palladium metal is also strongly adsorbed in the modified layer. However, since the palladium ion catalyst is not adsorbed in the non-circuit portion 22 that is not surface-modified because it is not irradiated with ultraviolet light, palladium metal is not fixed to the non-circuit portion 22.

  Next, in the step (E), the substrate 2 is immersed in an electroless copper plating solution, and copper metal is deposited using palladium metal firmly fixed in the modified layer as a nucleus. The plating layer 4 is formed. For example, the substrate 2 is immersed for about 15 minutes in an electroless copper plating solution (for example, product “AISL-520” manufactured by JCU Co., Ltd.) whose liquid temperature is set to 50 ° C. Thereby, an electroless copper plating layer having a thickness of 0.5 to 0.6 μm is formed.

  Here, in the case where the residue of electroless copper plating at the initial stage of the precipitation reaction remains in the non-circuit portion 22, as a step (F), the temperature is set to 40 ° C. and the concentration of 10 g / liter of persulfuric acid. If the substrate 1 is immersed in an aqueous solution for about 20 seconds, the remaining electroless copper plating residue can be reliably removed.

  The time required to modify the surface of the synthetic resin by irradiating the surface of the synthetic resin with ultraviolet rays using the low-pressure mercury lamp according to the prior art and the mercury lamp according to the present invention was compared. Here, a polyamide resin (nylon: Kuraray Co., Ltd. product “Genesta TA112”) is used as a synthetic resin, and a plate-like substrate is injection-molded. The electroless plating layer is formed on the surface of the polyamide resin by the method described above. Formed.

  The test conditions are as follows.

Item Mercury lamp according to the present invention Low pressure mercury lamp according to the prior art Mercury lamp Mercury lamp shown in Fig. 1 Standard low pressure mercury lamp
(Product of Koto Electric Co., Ltd. “KOGLQ-300GS”)
Arc length 250mm 2000mm
Output 3000W 300W
Irradiation distance 290mm 30mm
FIG. 3 shows the test results. FIG. 3 plots the adhesion strength of the electroless plating layer at each irradiation time while changing the irradiation time of ultraviolet rays. The adhesion strength of the electroless plating layer was the peel strength according to “Plating adhesion test: JISH8504”.

  As can be seen in FIG. 3, when using a low-pressure mercury lamp according to the prior art, an irradiation time of 20 minutes or more as shown by the broken line in order to maximize the peel strength (0.6 kN / m). Is required. On the other hand, when the mercury lamp according to the present invention is used, an irradiation time of only 5 minutes or less is sufficient for the peel strength to be 0.6 kN / m, as shown by the solid line.

  That is, when the mercury lamp according to the present invention is used, it is possible to reduce the irradiation time until obtaining the almost maximum adhesion strength by using the low pressure mercury lamp according to the prior art to 5 minutes / 20 minutes = 1/4 = 25%. confirmed. Such a significant shortening effect is far beyond expectations, and it is expected that this will greatly improve productivity.

  A liquid crystal polymer (Kuraray Co., Ltd. product “Vexstar OC”) was used as a synthetic resin, and a comparative test similar to the method described above was performed. The test results are shown in FIG. As is clear from FIG. 4, it was confirmed that the irradiation time required to obtain a substantially maximum adhesion strength can be significantly shortened to 2 minutes / 5 minutes = 40% using a low-pressure mercury lamp according to the prior art.

  For the mercury lamp according to the present invention and the low-pressure mercury lamp according to the prior art, the irradiation intensity of ultraviolet rays having wavelengths of 185 nm and 254 nm that exert an effect on the surface modification of the synthetic resin was compared. For reference, a comparison was also made with respect to ultraviolet rays having a wavelength of 351 nm. The result of this comparative test is shown in FIG.

  As a reference for the ultraviolet irradiation conditions, a comparative test was conducted by matching the irradiation intensity with a wavelength of 185 nm, which is considered to be most effective for the surface modification of the synthetic resin. The reason for adopting such a standard is as follows. That is, for example, a method of matching the irradiation distance to a non-irradiated body (here, a UV intensity measuring device) is conceivable. However, the irradiation distance of both is 290 mm (the irradiation distance of the mercury lamp according to the present invention shown in FIG. 5). ), The intensity of ultraviolet irradiation by the low-pressure mercury lamp of the prior art becomes extremely low, and accurate measurement becomes difficult.

  On the other hand, if the irradiation distance of both is 30 mm (the irradiation distance of the low-pressure mercury lamp according to the prior art shown in FIG. 5), the ultraviolet irradiation intensity by the mercury lamp according to the present invention becomes excessive, and accurate measurement is possible. It becomes difficult. That is, since the irradiation intensity of ultraviolet rays by the mercury lamp according to the present invention and the low-pressure mercury lamp of the prior art is greatly different, it is difficult to match the irradiation distances of the two. A method of matching the outputs of the two is also conceivable. For example, in order to match the mercury lamp according to the present invention with the output of the low-pressure mercury lamp according to the prior art, a mercury lamp having a size and a structure capable of exhibiting such output is used. It is necessary to make a new one only for testing.

  Therefore, the standard 300W low-pressure mercury lamp currently used for surface modification of synthetic resins and the mercury lamp according to the present invention are used, and the irradiation intensity at the wavelength of 185 nm is matched by changing the irradiation distance between them. A comparative test was conducted as described above.

As shown in FIG. 5, at a wavelength of 185 nm, the irradiation intensity of both ultraviolet rays is the same at 6.5 mw / cm ² , but the irradiation distance of the mercury lamp according to the present invention is almost 10 times that of the low-pressure mercury lamp. . Therefore, the irradiation intensity of ultraviolet rays at a wavelength of 185 nm is much higher in the mercury lamp of the present invention than in the low-pressure mercury lamp. Also, at wavelengths of 254 nm and 351 nm, the irradiation intensity of ultraviolet rays by the mercury lamp of the present invention is much higher than that of the low-pressure mercury lamp, although the irradiation distance is almost 10 times.

  As shown in FIG. 5, it was confirmed that the mercury lamp according to the present invention significantly increased the irradiation intensity of ultraviolet rays at wavelengths of 185 nm and 254 nm, as compared with the low-pressure mercury lamp according to the prior art. The significant reduction in the ultraviolet irradiation time described above is thought to be due to a significant increase in the irradiation intensity of ultraviolet rays having wavelengths of 185 nm and 254 nm.

  When forming the electroless plating layer, the irradiation time of ultraviolet rays for modifying the surface of the synthetic resin can be greatly shortened, so that it can be widely used in the industry related to electroless plating.

DESCRIPTION OF SYMBOLS 1 Mercury lamp 11 Arc tube 12 Base 13 Base 14 Electrode 15 Electrode 2 Base body 21 Portion to be a circuit 22 Portion to be a non-circuit 3 Mask 4 Electroless copper plating layer (electroless plating layer)

Claims (1)

A mercury lamp used to modify the surface of a synthetic resin that forms an electroless plating layer,
The mercury lamp comprises a straight tube type quartz glass arc tube having electrodes at both ends,
The arc tube is filled with mercury in an amount such that the vapor pressure during stable lighting is 1 to 10 atmospheres,
The quartz glass constituting the arc tube has a content of impurities (A) to (F) not exceeding the following numerical values,
The irradiation intensity of ultraviolet light having a wavelength of 185nm and 254nm is in the irradiation distance 150 mm, characterized in that each of at least 6.5 mW / cm ² and 130 mW / cm ^2.
(A) Aluminum (Al): 0.05 ppm
(B) Sodium (Na): 0.02 ppm
(C) Lithium (Li) and copper (Cu): 0.01 ppm
(D) potassium (K), magnesium (Ma), iron (Fe) and
Calcium (Ca): 0.005 ppm
(E) OH group: 300 ppm
(F) Other impurities: 0.1 ppm

Images