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Publication numberUS1809276 A
Publication typeGrant
Publication dateJun 9, 1931
Filing dateJul 2, 1929
Priority dateMar 4, 1929
Also published asDE571018C
Publication numberUS 1809276 A, US 1809276A, US-A-1809276, US1809276 A, US1809276A
InventorsWilliam Johnston
Original AssigneeAcetex Safety Glass Ltd
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Manufacture of compound sheets of glass and cellulose derivative composition
US 1809276 A
Abstract  available in
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Claims  available in
Description  (OCR text may contain errors)

U adherently secured to two tact, the glass sheets and Patented June 9, 1931 UNITED STATES WILLIAM JOHNSTON, OF

ASHFORD, ENGLAND, ASSIGNOR'TO ACETEX SAFETY GLASS LIMITED, 01? LONDON, ENGLAND MANUFACTURE OF COMPOUND SHEETS 0F GLASS AND CELLULOSE DERIVATIVE COMPOSITION Ho Drawing. Application filed July 2, 1929, Serial No. 375,594, and in Great Britain March 4,

This invention relates to the manufacture of compound sheets, comprising a sheet of cellulose derivative composition, such as cellulose acetate, interposed between and sheets of glass. According to the invention, two sheets of glass are caused to adhere to'an interposed sheet of cellulose such as cellulose acetate, by moistening the 10 surface of the cellulose derivative composition sheet with a plasticizer or solvent of high boiling point; initially pressing together the three sheets by an inert gas under pressure, so that they are in direct, close, surface conedges of all the sheets being freely exposed to the gas; and finally subjecting the sheets to steam under pressure. The steam is at a temperature less than the boiling point of the plasticizer or solvent, and the sheets are similarly freely exposed to the steam as they were to the inert gas.

Prior to subjecting the sheets to gas and steam pressure, superflous liquid and air are eliminated. This can be done by passing the sheets between rubber faced rollers.

The gas and steam pressure treatments can be effected in an autoclave into which compressed air is admitted to effect the initial pressing and subsequently the steam to eflect the final pressing.

A suitable pla-sticizer for use with cellulose acetate is triacetin.

A representative example of one way of carrying out the above described process is as follows: I

A sheet of cellulose acetate, which has been previously moistened with triacetin by immersion in a bath thereof, is interposed between two sheets of glass. and the three sheets p are first rolled between rubber faced rollers to express air and excess liquid from between the sheets. The combined pack of sheets is then. placed in a closed chamber and subjected to the direct pressure of compresse air at a pressure of approximately 50 pounds absolute per square inch for a period of 15 minutes. After slight relaxation of the air pressure, steam at a pressure of approximately 50 pounds absolute to the square inch is leased, not unduly rapidly,

derivative composition, 1

then admitted to the closed chamber, and the pack of sheets is subjected to the pressure and temperature of the steam for a period of 15 minutes. The gaseous pressure is then reand the adhering sheets are then removed from the chamber.

The temperature of steam at the above )ressure is below the boiling point of triacetin which is 258 C. at atmospheric pressure.

The above mentioned pressures and periods can be varied somewhat without materially affecting the resultant product.

Claims:

1. A process for effecting the interadherence of two sheets of glass to an interposed sheet of cellulose derivative composition, consisting in moistening the surface of said cellulose derivative composition sheet solely with a plasticizer of high boiling point, initially freely exposing and pressing together said glass sheets with said moistened cellulose derivative composition sheet interposed in a gas under pressure inert to said cellulose derivative composition sheet, and finally freely exposing and pressing said sheets in steam under pressure and at a temperature lower than the boiling point of said plasticizer.

2. A process for ence of two sheets effecting the interadherof glass to an interposed sheet of cellulose derivative composition, consisting in moistening the surface of said cellulose derivative composition sheet solely with a plasticizer of high boiling point, initially freely exposing and pressing together said glass sheets with said moistened cellu* lose derivative composition sheet interposed in compressed air, and finally freely exposing and pressing said sheets in steam under ressure and at a temperature lower than the boiling point of said plasticizer.

3. A process for effecting the interadheronce of two sheets of glass to an interposed sheet of cellulose acetate, consisting in moistening the surface of said cellulose acetate sheet solely with triacetin, initially freely exposing and pressing together said glass sheets with said moistened cellulose acetate sheet interposed in a gas under pressure inert to said cellulose acetate sheet, and

finally freely exposing and pressing said sheets in steam under pressure and at a temperature lower than the boiling point of said triacetin.

4. A process for effecting the interadherence of two sheets of glass to an interposed sheet of cellulose acetate, consisting in moistening the surface of said cellulose acetate sheet solely with triacetin, initially freely exposing and pressing together said glass sheets with said moistened cellulose acetate sheet interposed in compressed air, and finally freely exposing and pressing said sheets in steam under pressure and at a temperature lower than the boiling point of said triacetin.

5. A process for effecting the interadherence of two sheets of glass to an interposed sheet of cellulose derivative composition, consisting in moistening the surface of said cellulose derivative composition sheet solely with a plasticizer of high boiling point, initially freely exposing and pressing together said glass sheets with said moistened cellulose derivative composition sheet interposed in a gas under pressure inert to said cellulose derivative composition sheet, slightly relaxing the pressure of said inert as, and finally admitting to said gas under relaxed pressure steam under pressure and at a temperature lower than the boiling point of said plasticizer.

6. A process for effecting the interadherence of two sheets of glass to an interposed sheet of cellulose derivative composition, consisting in moistening the surface of said cellulose derivative composition sheet solely with a plasticizer of high boiling point, initially freely exposing and pressing together said glass sheets with said moistened cellulose derivative composition sheet interposed in compressed air, slightly relaxing the pressure of said compressed air and finally admitting to said compressed air under relaxed pressure steam under pressure and at a temperature lower than the boiling point of said plasticizer.

7. A process for effecting the interadherence of two sheets of glass to an interposed sheet of cellulose acetate, consisting in moistening the surface of said cellulose acetate sheet solely with triacetin, initially freely exposing and pressing together said glass sheets with said moistened cellulose acetate sheet interposed in a gas under pressure inert to said cellulose acetate, slightly relaxing the pressure of said inert gas, and finally admitting to said gas under relaxed pressure steam under pressure and at a temperature lower than the boiling point of said triacetin.

8. A process for effecting the interadherence of two sheets of glass to an interposed sheet of cellulose acetate, consisting in moistening the surface of said cellulose WILLIAM JOHNSTON.

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4385951 *Mar 25, 1981May 31, 1983Ppg Industries, Inc.Low pressure lamination of safety glass
Classifications
U.S. Classification156/105, 156/106
International ClassificationB32B17/06, B32B17/08
Cooperative ClassificationB32B17/08
European ClassificationB32B17/08