Appeal No. 96-1971
Application 07/914,388
a) heating a composition comprising a crystallizable polyester and an impact modifier to a
temperature above the melting point temperature of the polyester for a time sufficient to bring said
polyester to a substantially amorphous molten state;
b) maintaining the composition heated in step (a) at a temperature above said melting point
temperature for a time sufficient to substantially eliminate previous molecular stress imprinting and until
an effective amount of said impact modifier is dissolved in said polyester;
(c) controlling cooling of the composition in step (b) at a rate of from about 1 C to about 89 CO O
per minute until there is crystallization of the polyester and impact modifier forming a
mixture of precipitated particles of impact modifier embedded in a matrix of the polyester, said
precipitate of the impact modifier having a particle size of from about 0.1 to about 10 microns in
diameter; and
d) continuing controlled cooling of the composition by contacting the composition to a surface
capable of imparting shape for from about 1 second to about 5 minutes, said contact surface being at a
temperature of at least the lower boundary crystallization from melt temperature of said polyester
to provide an impact modified polyester, wherein said impact modified polyester has an oxygen
permeability of from about 0.2 to about 4.0 cc-mil/100 in -24 hr-atm at 23 C and 60% relative2 O
humidity outside/100% relative humidity inside and a heat of recrystallization of from about 0 to about -
4.0 calories per gram as measured by differential scanning calorimetry at a heating rate of about 250
C/minute.
THE REFERENCES OF RECORD
As evidence of obviousness, the examiner relies upon the following references.
Jones et al. (Jones) 3,562,200 Feb. 9, 1971
Duffield et al. (Duffield) 4,061,706 Dec. 6, 1977
Carson 4,713,268 Dec. 15, 1987
THE REJECTIONS
Claims 1 through 3, 5 through 22, 24 through 28, 70, 71, 74, and 75 stand rejected under 35
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