Dowa Metaltech Co., Ltd.

Rion Company Ltd.

Keisuke Shinohara

Hiroshi Miyazawa

Masafumi Ogata

Akira Sugawara

Shunki Sadamori

Atsushi Saito

Takashi Iwakura

A silver-plated product is produced by forming a surface layer of silver on a base material by electroplating at a liquid temperature of 10 to 35&#xb0; C. and a current density of 3 to 15 A/dmin a silver plating solution so as to satisfy (32.6x&#x2212;300)&#x2264;y&#x2264;(32.6x+200) assuming that a product of a concentration of potassium cyanide in the silver plating solution and a current density is y (g&#xb7;A/L&#xb7;dm) and that a liquid temperature of the silver plating solution is x (&#xb0; C.), the silver plating solution containing 80 to 110 g/L of silver, 70 to 160 g/L of potassium cyanide and 55 to 70 mg/L of selenium.

Silver-plated product and method for producing same

A silver-plated product, wherein the preferred orientation plane of a surface layer of silver is {111} plane and wherein the ratio of the full-width at half maximum of an X-ray diffraction peak on {111} plane after heating the silver-plated product at 50&#xb0; C. for 168 hours to the full-width at half maximum of an X-ray diffraction peak on {111} plane before the heating of the silver-plated product is not less than 0.5, is produced by forming the surface layer on a base material by electroplating at a liquid temperature of 12 to 24&#xb0; C. and a current density of 3 to 8 A/dmin a silver plating solution which contains 80 to 110 g/L of silver, 70 to 160 g/L of potassium cyanide and 55 to 70 mg/L of selenium, so as to cause the product of the concentration of potassium cyanide and the current density to be 840 g&#xb7;A/L&#xb7;dmor less.

There is provided a silver-plated product which has good thermal resistance, bendability and wear resistance. In a silver-plated product wherein a surface layer of silver having a thickness of 10 &#x3bc;m or less is formed on a base material of copper or a copper alloy, the full-width at half maximum of a rocking curve on a preferred orientation plane (preferably {200} or {111} plane) of the surface layer is caused to be 2 to 8&#xb0;, preferably 3 to 7&#xb0;, to improve the out-of-plane orientation of the surface layer to improve the thermal resistance, bendability and wear resistance of the silver-plated product.

Silver-plated product

There is provided a silver-plated product wherein a surface layer of silver is formed on the surface of an underlying layer of nickel formed on a base material, the silver-plated product having a good bendability. In a silver-plated product which comprises a base material of copper or a copper alloy, an underlying layer of nickel formed on the base material, and a surface layer of silver formed on the surface of the underlying layer, the surface layer having a thickness of 10 &#x3bc;m or less, the thickness of the underlying layer is 2 &#x3bc;m or less, preferably 1.5 &#x3bc;m or less, and the area fraction in {200} orientation of the surface layer is 15% or more, preferably 25% or more.

There is provided a silver-plated product wherein a silver plating film having a thickness of not greater than 10 micrometers is formed on a base material of copper or a copper alloy and wherein the surface of the silver plating film has an arithmetic average roughness Ra of not greater than 0.1 micrometers, and the silver plating film has a {111} orientation ratio of not less than 35%.

There is provided a silver-plated product which has a good bendability and which can restrain the rise of the contact resistance thereof even if it is used in a high-temperature environment, and a method for producing the same. In a silver-plated product wherein a surface layer of silver is formed on the surface of a base material of copper or a copper alloy, or on the surface of an underlying layer of copper or a copper alloy formed on the base material, the percentage of an X-ray diffraction intensity on {200} plane of the surface layer with respect to the sum of X-ray diffraction intensities on {111}, {200}, {220} and {311} planes of the surface layer is 40% or more.

Method for producing silver-plated product

In a silver-plated product wherein a surface layer of silver is formed on the surface of a base material or on the surface of an underlying layer formed on the base material, the surface layer of silver is formed by electroplating in a silver plating bath which contains 1 to 15 mg/L of selenium and wherein a mass ratio of silver to free cyanogen is in the range of from 0.9 to 1.8, and thereafter, an aging treatment is carried out to produce a silver-plated product wherein an area fraction in {200} orientation of the surface layer is 15% or more.

There is provided a waterproof hearing aid capable of being worn without caring about the entry of sweat or water even at the time of sweating or bathing. The waterproof hearing aid has a first waterproof film stretchingly provided at the sound inlet of a microphone and a second waterproof film stretchingly provided at the sound outlet of an earphone, a tube (first vent) communicating a microphone chamber formed by the first waterproof film and the microphone with a hearing aid case chamber formed by a hearing aid case, a tube (second vent) communicating an earphone chamber formed by the second waterproof film and the earphone with the hearing aid case chamber, and a porous film (third vent) communicating the hearing aid case chamber with the outside.

Growing community of inventors

Saitama, Japan

Keisuke Shinohara