US4394235A — Heat-sealable polypropylene blends and methods fo…

Claim 1

Independent Claim 55 words

A heat-sealable film consisting essentially of a corona discharge treated, biaxially oriented film comprising a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer.

Claim 2

Dependent Claim 55 words

A heat-sealable film consisting essentially of a corona discharge treated, biaxially oriented film comprising a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer.

Claim 3

Dependent Claim 27 words

The film of claim 1 wherein the copolymer consists of a copolymer of about 85% to about 40% terpene and about 15% to about 60% styrenic monomer.

Claim 4

Dependent Claim 15 words

The film of claims 1 or 2 wherein copolymer is a dipentene-styrene or limonene-styrene copolymer.

Claim 5

Dependent Claim 41 words

The film as in claim 3 wherein the copolymer consists of a copolymer of about 15% to about 30% styrene and about 85% to about 70% dipentene or limonene and has a ring and ball softening point above about 100° C.

Claim 6

Dependent Claim 31 words

A heat-sealable film as in claim 1 wherein the film in addition contains an antiblocking and/or slip agent functioning enhancing amount between about 0.5% to about 2% of a Fischer-Tropsch wax.

Claim 7

Dependent Claim 27 words

The film of claim 5 wherein the copolymer consists of a copolymer of about 85% to about 40% terpene and about 15% to about 60% styrenic monomer.

Claim 8

Dependent Claim 15 words

The film of claims 5 and 6 wherein copolymer is a dipentene-styrene or limonene-styrene copolymer.

Claim 9

Dependent Claim 41 words

The film as in claim 7 wherein the copolymer consists of a copolymer of about 15% to about 30% styrene and about 85% to about 70% dipentene or limonene and has a ring and ball softening point above about 100° C.

Claim 10

Dependent Claim 79 words

A heat-sealable film comprising a corona discharge treated, biaxially oriented film comprising a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of a copolymer of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer, and containing a coefficient of friction reducing, nonheat-seal preventing amount between about 0.02% to about 0.1% of a saturated fatty amide slip agent.

Claim 11

Dependent Claim 79 words

A heat-sealable film comprising a corona discharge treated, biaxially oriented film comprising a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of a copolymer of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer, and containing a coefficient of friction reducing, nonheat-seal preventing amount between about 0.02% to about 0.1% of a saturated fatty amide slip agent.

Claim 12

Dependent Claim 26 words

The film of claim 9 which has been aged at an elevated temperature for a time sufficient to reduce the coefficient of friction of the film.

Claim 13

Dependent Claim 29 words

The film of claims 9 or 10 wherein the copolymer consists of a copolymer of about 85% to about 40% terpene and about 15% to about 60% styrenic monomer.

Claim 14

Dependent Claim 13 words

The film of claim 11 wherein copolymer is a dipentene-styrene or limonene-styrene copolymer.

Claim 15

Dependent Claim 12 words

The heat-sealable film as in claim 9 wherein the amide comprises stearamide.

Claim 16

Dependent Claim 22 words

A heat-sealable film as in claim 9 wherein the film in addition comprises about 0.5% to about 2% of a Fischer-Tropsch wax.

Claim 17

Dependent Claim 27 words

The film of claim 14 wherein the copolymer consists of a copolymer of about 85% to about 40% terpene and about 15% to about 60% styrenic monomer.

Claim 18

Dependent Claim 13 words

The film of claim 14 wherein copolymer is a dipentene-styrene or limonene-styrene copolymer.

Claim 19

Dependent Claim 41 words

The film as in claim 14 wherein the copolymer consists of a copolymer of about 15% to about 30% styrene and about 85% to about 70% dipentene or limonene and has a ring and ball softening point above about 100° C.

Claim 20

Dependent Claim 19 words

A heat-sealable film as in claims 1, 5, 9 or 14 which in addition contains a particulate anti-blocking agent.

Claim 21

Independent Claim 77 words

A method of forming a heat-sealable polypropylene film which comprises subjecting a biaxially oriented film consisting essentially of a film comprising a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer to a corona discharge in an amount sufficient to enhance the heat-sealability of the film.

Claim 22

Independent Claim 77 words

A method of forming a heat-sealable polypropylene film which comprises subjecting a biaxially oriented film consisting essentially of a film comprising a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer to a corona discharge in an amount sufficient to enhance the heat-sealability of the film.

Claim 23

Dependent Claim 28 words

The method as in claim 19 wherein the corona discharge is conducted in a manner such that the temperature of the film is maintained below about 150° F.

Claim 24

Dependent Claim 32 words

The method as in claim 19 wherein the corona discharge is conducted in a manner such that the temperature of the film is maintained between about 100° F. and about 130° F.

Claim 25

Independent Claim 111 words

A method of forming a heat-sealable polypropylene film which comprises subjecting a biaxially oriented corona discharge treated film consisting essentially of a film comprising a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of a copolymer of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer, and containing a coefficient of friction reducing, non-heat-seal preventing amount between about 0.02% to about 0.1% of a saturated fatty amide slip agent to an aging at an elevated temperature for a time sufficient to reduce the coefficient of friction of the film.

Claim 26

Independent Claim 111 words

A method of forming a heat-sealable polypropylene film which comprises subjecting a biaxially oriented corona discharge treated film consisting essentially of a film comprising a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of a copolymer of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer, and containing a coefficient of friction reducing, non-heat-seal preventing amount between about 0.02% to about 0.1% of a saturated fatty amide slip agent to an aging at an elevated temperature for a time sufficient to reduce the coefficient of friction of the film.

Claim 27

Dependent Claim 37 words

A method of claim 22 wherein the heat aging is conducted with the film in roll form upon a core adapted to shorten the time required for all points with the roll to reach a predetermined temperature.

Claim 28

Dependent Claim 19 words

The method as in claim 22 wherein the core is a hollow core of a relatively heat conductive material.

Claim 29

Dependent Claim 100 words

A film having enhanced heat-sealability comprising a corona discharge treated, biaxially oriented film comprising a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of a copolymer of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer, where the film has been treated with corona discharge in an amount sufficient to enhance the heat sealability of the film, the corona discharge being conducted in a manner such that the temperature of the film is maintained below about 150° F.

Claim 30

Dependent Claim 100 words

A film having enhanced heat-sealability comprising a corona discharge treated, biaxially oriented film comprising a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of a copolymer of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer, where the film has been treated with corona discharge in an amount sufficient to enhance the heat sealability of the film, the corona discharge being conducted in a manner such that the temperature of the film is maintained below about 150° F.

Claim 31

Dependent Claim 23 words

The film as in claim 25 where the film temperature during corona discharge is maintained between about 100° F. and about 130° F.

Claim 32

Dependent Claim 30 words

The method as in claim 19 wherein the film in addition contains an antiblocking and/or slip agent functioning enhancing amount between about 0.5% to about 2% of a Fischer-Tropsch wax.

Claim 33

Dependent Claim 76 words

The method of claim 19 wherein the film comprises a blend of stereoregular polypropylene containing about 5% to about 25% by weight based on the total composition of a terpene-styrene or substituted styrene copolymer consisting of a copolymer of about 85% to about 25% terpene and about 15% to about 75% styrenic monomer, and containing a coefficient of friction reducing, non-heat-seal preventing amount between about 0.02% to about 0.1% of a saturated fatty amide slip agent.

Claim 34

Dependent Claim 20 words

The method of claim 28 wherein the film in addition comprises about 0.5% to about 2% of a Fischer-Tropsch wax.

Claim 35

Dependent Claim 10 words

The method of claim 22 wherein the amide comprises stearamide.

Claim 36

Dependent Claim 21 words

The method as in claim 22 wherein the film in addition comprises about 0.5% to about 2% of a Fischer-Tropsch wax.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1986-07-18	1987-01-17	1987-07-19	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1990-07-18	1991-01-17	1991-07-19	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1994-07-18	1995-01-17	1995-07-19	$7700.00	Window Closed / Lapsed

Heat-sealable polypropylene blends and methods for their preparation

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