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US4391833A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of making and using heat resistant resin coated paperboard product and product thereof

Assignee: International Paper Co
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Filing: 1978-04-24
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Granted: 1983-07-05
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Expires: 1998-04-24
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Abstract

Abstract A paperboard product resistant to discoloration and otherwise stable upon heating, coated on the first surface thereof with a pigmented water impermeable layer and on the second surface thereof with a pigmented water permeable layer. The paperboard product is desirably used as the material employed in containers for food that is to be cooked in conventional or microwave ovens. The container is constructed so that the food in the container is in contact with the water impermeable layer.

Inventors

  • 👤 Robert W. Self
  • 👤 Allan A. Whillock

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-24 04:10
CPC Classifications
B; B65; B65D; B65D81/00; B65D81/34; B65D81/3446; D; D21; D21H; D21H19/00; D21H19/36; D21H19/44; D21H19/62; Y; Y10; Y10S; Y10S148/00; Y10S148/085; Y10S229/00; Y10S229/941; Y10T; Y10T428/00; Y10T428/13; Y10T428/1303; Y10T428/31504; Y10T428/31786; Y10T428/3179; Y10T428/31971; Y10T428/31993

Claims Analysis

Total Claims: 21
Claim 1
Independent Claim 115 words
A paperboard product comprising: (a) a paperboard substrate having affixed to its first surface a water impermeable layer, said water impermeable layer comprising a binder with opaque pigment dispersed therein; and (b) a continuous water permeable layer affixed to the second surface of said paperboard substrate, said water permeable layer comprising a binder with opaque pigment dispersed therein, said paperboard product characterized by the facts that (i) it retains a brightness of at least 70% on its permeable side and at least 50% on its impermeable side after exposure to 400° F. for 30 minutes, and (ii) it will not puff or blister when placed in an oven heated to 350° F. for 15 minutes.
Claim 2
Dependent Claim 115 words
A paperboard product comprising: (a) a paperboard substrate having affixed to its first surface a water impermeable layer, said water impermeable layer comprising a binder with opaque pigment dispersed therein; and (b) a continuous water permeable layer affixed to the second surface of said paperboard substrate, said water permeable layer comprising a binder with opaque pigment dispersed therein, said paperboard product characterized by the facts that (i) it retains a brightness of at least 70% on its permeable side and at least 50% on its impermeable side after exposure to 400° F. for 30 minutes, and (ii) it will not puff or blister when placed in an oven heated to 350° F. for 15 minutes.
Claim 3
Dependent Claim 15 words
The product of claim 1 wherein the pigment in the impermeable layer comprises titanium dioxide.
Claim 4
Dependent Claim 21 words
The product of claim 1 wherein the pigment in the permeable layer comprises a mixture of titanium dioxide and kaolin clay.
Claim 5
Dependent Claim 22 words
The product of claim 1 wherein the impermeable layer binder comprises polytetramethylene terephthalate, polycyclohexalene dimethylene terephthalate or polycyclohexalene dimethylene terephthalate-phthalic acid copolymer.
Claim 6
Dependent Claim 13 words
The product of claim 4 wherein the permeable layer binder comprises polyvinyl acetate.
Claim 7
Dependent Claim 53 words
The product of claim 1 wherein the impermeable layer comprises from about 2.5% to about 20% by weight titanium dioxide and the permeable layer comprises about 15 to 80 parts by weight titanium dioxide, about 20 to 85 parts by weight kaolin clay and about 10 to 30 parts by weight polyvinyl acetate.
Claim 8
Dependent Claim 14 words
The product of claim 1 wherein the water impermeable layer is also grease impermeable.
Claim 9
Dependent Claim 20 words
The product of claim 1 wherein the product has a water content of about 3% to about 10% by weight.
Claim 10
Dependent Claim 133 words
A paperboard container for cooking food comprising a coated paperboard substrate formed into the shape of a container, said container comprising: (a) an inside surface comprising a water impermeable layer affixed to said paperboard substrate, said water impermeable layer comprising a binder with opaque pigment dispersed therein; and (b) an outside surface comprising a continuous water permeable layer affixed to said paperboard substrate, said water permeable layer comprising a binder with opaque pigment dispersed therein, said paperboard container being characterized by the facts that (i) it retains a brightness of at least 70% on its permeable side and at least 50% on its impermeable side after exposure to 400° F. for 30 minutes; and (ii) it will not puff or blister when placed in an oven heated to 350° F. for 15 minutes.
Claim 11
Dependent Claim 133 words
A paperboard container for cooking food comprising a coated paperboard substrate formed into the shape of a container, said container comprising: (a) an inside surface comprising a water impermeable layer affixed to said paperboard substrate, said water impermeable layer comprising a binder with opaque pigment dispersed therein; and (b) an outside surface comprising a continuous water permeable layer affixed to said paperboard substrate, said water permeable layer comprising a binder with opaque pigment dispersed therein, said paperboard container being characterized by the facts that (i) it retains a brightness of at least 70% on its permeable side and at least 50% on its impermeable side after exposure to 400° F. for 30 minutes; and (ii) it will not puff or blister when placed in an oven heated to 350° F. for 15 minutes.
Claim 12
Dependent Claim 19 words
A process for cooking food in a paperboard container comprising heating food in the container defined by claim 9.
Claim 13
Dependent Claim 139 words
A paperboard container for cooking food comprising a coated paperboard substrate formed into the shape of a container, said container comprising: (a) an inside surface comprising a water and grease impermeable layer affixed to said paperboard substrate, said water and grease impermeable layer comprising a binder with opaque white pigment dispersed therein; and (b) an outside surface comprising a continuous water permeable layer affixed to said paperboard substrate, said water permeable layer comprising a binder with opaque white pigment dispersed therein, said paperboard container being characterized by the facts that (i) it retains a brightness of at least 70% on its permeable side and at least 50% on its impermeable side after exposure to 400° F. for 30 minutes; and (ii) it will not puff or blister when placed in an oven heated to 350° F. for 15 minutes.
Claim 14
Dependent Claim 139 words
A paperboard container for cooking food comprising a coated paperboard substrate formed into the shape of a container, said container comprising: (a) an inside surface comprising a water and grease impermeable layer affixed to said paperboard substrate, said water and grease impermeable layer comprising a binder with opaque white pigment dispersed therein; and (b) an outside surface comprising a continuous water permeable layer affixed to said paperboard substrate, said water permeable layer comprising a binder with opaque white pigment dispersed therein, said paperboard container being characterized by the facts that (i) it retains a brightness of at least 70% on its permeable side and at least 50% on its impermeable side after exposure to 400° F. for 30 minutes; and (ii) it will not puff or blister when placed in an oven heated to 350° F. for 15 minutes.
Claim 15
Dependent Claim 26 words
The container of claim 11 wherein the impermeable layer comprises titanium dioxide and polytetramethylene terephthalate and the permeable layer comprises polyvinylacetate, titanium dioxide and kaolin clay.
Claim 16
Dependent Claim 20 words
The container of claim 11 wherein the container has a water content of about 3% to about 10% by weight.
Claim 17
Dependent Claim 52 words
A process for producing a paperboard product comprising: (a) affixing a continuous water permeable layer comprising a mixture of binder and opaque pigment to a first surface of a paperboard substrate; and (b) affixing a water impermeable layer comprising a binder and opaque pigment to a second surface of said paperboard substrate.
Claim 18
Dependent Claim 52 words
A process for producing a paperboard product comprising: (a) affixing a continuous water permeable layer comprising a mixture of binder and opaque pigment to a first surface of a paperboard substrate; and (b) affixing a water impermeable layer comprising a binder and opaque pigment to a second surface of said paperboard substrate.
Claim 19
Dependent Claim 44 words
The process of claim 14 wherein the water impermeable layer is affixed onto the second surface of the paper substrate by extruding the impermeable mixture onto the second surface and then chilling the coated substrate to harden and set the impermeable layer extruded thereon.
Claim 20
Dependent Claim 35 words
The process of claim 14 wherein the permeable layer is affixed to the paperboard substrate by first coating an aqueous slurry of the permeable layer onto the paperboard substrate and then drying the coated substrate.
Claim 21
Dependent Claim 28 words
The process of claim 16 wherein after the permeable layer is dried a second coating of aqueous slurry is coated onto the once coated substrate and subsequently dried.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-07-04 1987-01-03 1987-07-05 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-07-04 1991-01-03 1991-07-05 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-07-04 1995-01-03 1995-07-05 $7700.00 Window Closed / Lapsed

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