Stock material or miscellaneous articles – Composite – Of metal
Reexamination Certificate
1999-12-15
2002-10-22
Maki, Steven D. (Department: 1733)
Stock material or miscellaneous articles
Composite
Of metal
C156S272200, C156S273300, C156S308200, C156S309600, C428S901000
Reexamination Certificate
active
06468665
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for melt-bonding a molded article of a thermotropic liquid crystalline polyester resin with a metal and a process for producing a molded article formed from a molded article of a thermotropic liquid crystalline polyester resin and a metal.
2. Description of the Related Art
Since thermotropic liquid crystalline polyester resins (hereinafter, sometimes may be referred to as liquid crystalline polymers) have characteristics that they are superior in heat resistance and excellent in flowability at a molten state, they have become widely used centering around the field of electronic materials as injection molding materials usable in high precision molding. One of use thereof in which their heat resistance and lower linear thermal expansion, parts of their excellent characteristics, are made good use is a product for use as mechanical parts, electric parts and electronic parts produced by plating or adhering a metal on a surface of a part molded by injection molding or a film molded by extrusion molding.
In these parts, the molded article and the metal must be adhered with a sufficient strength for practical use. The molded articles of a thermotropic liquid crystalline polyester resin, however, have a weak contact ability because of strong molecular orientation on the surface of molded article and are inactive to almost all chemicals. Therefore, sometimes a sufficient adhesive strength can not be obtained upon adhesion or plating.
Thus, various processes have been attempted for improving adhesive strength between molded articles of a thermotropic liquid crystalline polyester resin and metals. For example, JP-A-1-216824 discloses, as a method for modifying a surface of a molded article of a thermotropic liquid crystalline polyester, a process for obtaining a surface suitable for painting, printing, adhesion, deposition, plating and so on by irradiating with ultraviolet rays. In addition, JP-A-9-100359 discloses a process for obtaining a surface of a molded article excellent in adhesive strength upon plating or others by partially irradiating a surface of a molded article of a thermotropic liquid crystalline polyester resin with ultraviolet rays and then roughening the surface with an etching solution.
When, however, a thermotropic liquid crystalline polyester resin is adhered to a metal by an adhesive, the property of the adhered molded article is strongly damaged due to an inferior property of the adhesive, although the thermotropic liquid crystalline polyester resin is excellent in properties such as heat resistance and dielectric property. In addition, plating requires troublesome steps such as etching.
On the other hand, various processes have been attempted in which a metal and a thermotropic liquid crystalline polyester resin are melt-bonded rather than adhering or plating. In one example, JP-A-8-58024 discloses a process for obtaining a laminate useful as a substrate for circuit by melt-bonding a film of thermotropic liquid crystalline polyester resin with a copper foil.
Even such a product obtained by a process in which a molded article of thermotropic liquid crystalline polyester resin is melt-bonded with a metal has sometimes not a sufficient adhesive strength between the liquid crystalline polyester resin and the metal.
The object of the present invention is to provide a process for melt-bonding a molded article of a thermotropic liquid crystalline polyester resin with a metal with firmness and a process for producing a laminated product in which a molded article of a thermotropic liquid crystalline polyester resin molded article and a metal is laminated with firmness.
SUMMARY OF THE INVENTION
As the result of extensive studies for resolving the above problems, the present inventors have found that the above object can be attained by previously activating a surface of a molded article of a thermotropic liquid crystalline polyester resin and melt-bonding said surface with a metal at or above the flow temperature of said thermotropic liquid crystalline polyester resin. Thus, they have completed the present invention.
The present invention relates to (1) a process for melt-bonding a molded article of a thermotropic liquid crystalline polyester with a metal which comprises activating a surface of a molded article of a thermotropic liquid crystalline polyester resin and melt-bonding said surface with a metal at or above the flow temperature of said thermotropic liquid crystalline polyester resin.
Also, the present invention relates to (2) a process for melt-bonding a molded article of a thermotropic liquid crystalline polyester with a metal which comprises previously irradiating a surface of a molded article of a thermotropic liquid crystalline polyester resin with ultraviolet rays containing a wavelength 254 nm and melt-bonding said surface with a metal at or above the flow temperature of said thermotropic liquid crystalline polyester resin.
Further, the present invention relates to (3) a molded article comprising a molded article of a thermotropic liquid crystalline polyester and a metal, which is melt-bonded by the process according to above (1) or (2).
Still further, the present invention relates to (4) a process for producing a molded article formed from a molded article of a thermotropic liquid crystalline polyester and a metal which comprises, in a process for producing a molded article formed from a molded article of a thermotropic liquid crystalline polyester and a metal, previously irradiating a surface of a molded article of a thermotropic liquid crystalline polyester resin with ultraviolet rays containing a wavelength 254 nm and melt-bonding said surface with a metal at or above the flow temperature of said thermotropic liquid crystalline polyester resin.
Further, the present invention relates to (5) a process for producing a laminated product formed from a thermotropic liquid crystalline polyester and a metal which comprises, in a process for producing a laminated product formed from a molded article of a thermotropic liquid crystalline polyester and a metal, previously irradiating a surface of a molded article of a thermotropic liquid,crystalline polyester resin with ultraviolet rays containing a wavelength 254 nm and melt-bonding said surface with a metal at or above the flow temperature of said thermotropic liquid crystalline polyester resin.
DETAILED DESCRIPTION OF THE INVENTION
The molded article of a thermotropic liquid crystalline polyester used in the present invention is a product molded from thermotropic liquid crystalline polyester resin by injection molding, extrusion molding or the like. Particularly, the molded articles in the form of films or sheet can be used as substrates for circuit excellent in heat resistance, dimension accuracy and the like by bonding together with a copper foil.
The thermotropic liquid crystalline polyester resin for obtaining such molded article can be obtained by polycondensation reaction with combining monomers of an aromatic hydroxyl carboxylic acid, an aromatic dicarboxylic acid and an aromatic dihydroxyl compound.
Examples of the aromatic hydroxyl carboxylic acid unit include:
Examples of the aromatic dihydroxyl compound unit include:
Examples of the aromatic dicarboxylic acid unit include:
While combination and ratio of the monomer components may be determined according to desired object, it is preferred that the components represented by the following formulae (1), (2), (3) and (4) or formulae (1) and (5) are contained in an amount of 97% by mole or more, based on the total amount, for a liquid crystalline polyester having a high heat resistance and a suitable flowability.
Among them, components represented by the formulae (1), (2), (3) and (4) are preferred for thermotropic liquid. crystalline polyester resin having a higher heat resistance. More preferred are those having the component represented by the formula (1) in an amount of 40 to 70% by mole based on the total amount, the amount of the components represented
Nagashima Tohru
Nakamura Hiroshi
Birch & Stewart Kolasch & Birch, LLP
Maki Steven D.
Sumitomo Chemical Company Limited
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