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Inexpensive Preparation of Hydrophilic-Coated Masters for Electro-Erosion Printing

IP.com Disclosure Number: IPCOM000119781D
Original Publication Date: 1991-Feb-01
Included in the Prior Art Database: 2005-Apr-02
Document File: 1 page(s) / 61K

Publishing Venue

IBM

Related People

Afzali-Ardakani, A: AUTHOR [+4]

Abstract

Research has determined that direct negatives and masters prepared for electro-erosion writing are most effective if the silica-containing base layer and intermediate thin aluminum layer are coated with a lubricating overlayer containing graphite particles. This overlayer protects the aluminum from air during storage so that it does not become hydrophobic and suppresses scratching of the aluminum by the stylus during writing. The separately applied hydrophilic overlayer adds significantly to the costs of master fabrication, however. This article suggests a simple method of applying a hydrophilic coating to the back of the polyester substrate before the rest of the structure is fabricated. Such a coating is inexpensive and can be done by a manufacturer other than the fabricator of the remainder of the master.

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Inexpensive Preparation of Hydrophilic-Coated Masters for Electro-Erosion
Printing

      Research has determined that direct negatives and masters
prepared for electro-erosion writing are most effective if the
silica-containing base layer and intermediate thin aluminum layer are
coated with a lubricating overlayer containing graphite particles.
This overlayer protects the aluminum from air during storage so that
it does not become hydrophobic and suppresses scratching of the
aluminum by the stylus during writing.  The separately applied
hydrophilic overlayer adds significantly to the costs of master
fabrication, however.  This article suggests a simple method of
applying a hydrophilic coating to the back of the polyester substrate
before the rest of the structure is fabricated.  Such a coating is
inexpensive and can be done by a manufacturer other than the
fabricator of the remainder of the master.

      Aluminum deposition is the last step in the manufacturing
process of direct negatives and masters. Using the new approach
described here, during the rewind operation in vacuum, the ackside of
the hydrophilic-coated polyester web contacts the fresh, highly
reactive aluminum, and a thin layer of the hydrophobic coating
transfers to the aluminum.  It may be noted that this transfer does
not take place during wind-up operations, directly after the basecoat
is applied, because the basecoat is hydrophobic.

      Polyethylene glycol, which is soft and hydrophilic...