← Back to Patent Explorer
US5286576A Expired / Lapsed US ⏱️ 0.0 years remaining

Compression molded flame retardant and high impact strength ultra high molecular weight polyethylene composition

Assignee: Duramax Marine LLC
•
Filing: 1991-09-12
•
Granted: 1994-02-15
•
Expires: 2011-09-12
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract Impact resistant and flame retardant polymer composition, slab-like rectangular solid made of said composition, and composite laminate article having at least one layer of said composition. The polymer composition comprises a maximum of 86 volume percent of ultra high molecular weight polyethylene (UHMWPE), a minimum of 4.40 volume percent of a flame retardant additive or mixture thereof, and a minimum of 6 volume percent of chopped reinforcing fibers, all volumes referring to the densified (molded) state. In addition the bulk volume of the chopped reinforcing fibers, as measured by a tapped density test, must be a minimum of 27 percent of the final molded volume of the composition. The maximum volume % loading of the additives is limited by the requirement that the notched Izod impact strength is a minimum of 7 ft.-lb per inch width. The preferred flame retardant additive is essentially a water insoluble form of ammonium polyphosphate having a water solubility not exceeding 1 gram per 100 grams of water, and the preferred reinforcing fibers are chopped glass fibers about 1/8 to 1/4" inch in length.

Inventors

  • 👤 Raymond C. Srail
  • 👤 Richard A. Glover
  • 👤 Roy L. Orndorff, Jr.

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-04 09:23
CPC Classifications
B; B32; B32B; B32B27/00; B32B27/18; B32B27/06; B32B27/08; C; C08; C08L; C08L23/00; C08L23/02; C08L23/04; C08L23/06; B32B27/12; B32B27/32; C08K; C08K3/00; C08K3/32; C08K7/00; C08K7/02; C08K7/04; C08K7/14; B32B2262/00; B32B2262/10; B32B2262/101; B32B2307/00; B32B2307/30; B32B2307/306; B32B2307/3065; B32B2307/50; B32B2307/558; B32B2323/00; B32B2323/04; B32B2323/043; Y; Y10; Y10S; Y10S428/00; Y10S428/92; Y10S428/921; Y10T; Y10T428/00; Y10T428/249921; Y10T428/249924; Y10T428/24994; Y10T428/25; Y10T428/252; Y10T428/31504; Y10T428/31855; Y10T428/31909; Y10T428/31913; Y10T428/31917

Claims Analysis

Total Claims: 23
Claim 1
Independent Claim 140 words
A compression molded polymer composition having good flame retardancy and high impact strength, comprising: a) a polymer which is a high impact strength ultra-high molecular weight polyethylene (UHMWPE) which is free of halogen and cyanide or derivatives thereof on combustion; b) at least 4.40 percent by volume as molded ammonium polyphosphate (APP); and c) at least 6 percent by volume as molded of chopped glass fibers; wherein the maximum amount of component (b) in combination with component (c) as molded is an amount such that composition has a notched Izod impact strength of at least about 7 ft.lbs. per inch of width, wherein the bulk volume percent fiberglass (BVPF) prior to molding is at least about 27 percent of the volume of the polymer composition as molded, and wherein said polymer composition exhibits no flame drip according to ASTM E-162.
Claim 2
Dependent Claim 140 words
A compression molded polymer composition having good flame retardancy and high impact strength, comprising: a) a polymer which is a high impact strength ultra-high molecular weight polyethylene (UHMWPE) which is free of halogen and cyanide or derivatives thereof on combustion; b) at least 4.40 percent by volume as molded ammonium polyphosphate (APP); and c) at least 6 percent by volume as molded of chopped glass fibers; wherein the maximum amount of component (b) in combination with component (c) as molded is an amount such that composition has a notched Izod impact strength of at least about 7 ft.lbs. per inch of width, wherein the bulk volume percent fiberglass (BVPF) prior to molding is at least about 27 percent of the volume of the polymer composition as molded, and wherein said polymer composition exhibits no flame drip according to ASTM E-162.
Claim 3
Dependent Claim 38 words
The polymer composition according to claim 1, wherein the volumetric ratio of (b) to (c) is between about 0.465 and 1.65 as molded, and wherein the weight average molecular weight of said UHMWPE is at least 21/2 million.
Claim 4
Dependent Claim 48 words
The polymer composition according to claim 2, wherein said APP is present in an amount of about 12.13 volume percent; wherein said chopped fiberglass is present in an amount of about 8.69 volume percent; and wherein said UHMWPE is present in an amount of about 79.18 volume percent.
Claim 5
Dependent Claim 56 words
The polymer composition according to claim 1, wherein said composition has a flame spread index, according to ASTM E-162, achieves a class A rating, corresponding to less than 25 percent compared to that of pure ultra-high molecular weight polyethylene (UHMWPE) and wherein the weight average molecular weight of said UHMWPE is at least about 21/2 million.
Claim 6
Dependent Claim 15 words
The polymer composition according to claim 4, wherein said ammonium polyphosphate is essentially water insoluble.
Claim 7
Dependent Claim 36 words
A shaped article for protecting an object from impact damage comprising the polymer composition of claim 1, and wherein the weight average molecular weight of said UHMWPE is between about 3 million to about 7 million.
Claim 8
Dependent Claim 29 words
The shaped article according to claim 6, said shaped article being a panel of essentially rectangular shape in which the length and width are substantially greater than the thickness.
Claim 9
Dependent Claim 89 words
A molded composition comprising: a compression molded article having a notched Izod impact strength of at least about 7 ft.-lbs. per inch of width, said compression molded article made from a blend of a) a polymer powder which is UHMWPE powder; b) ammonium polyphosphate in powder form; and c) chopped glass fibers; wherein the bulk volume percent fiberglass (BVPF) prior to molding is at least 27 percent of the volume of the polymer composition as molded, and wherein said molded composition exhibits no flame drip according to ASTM E-162.
Claim 10
Dependent Claim 89 words
A molded composition comprising: a compression molded article having a notched Izod impact strength of at least about 7 ft.-lbs. per inch of width, said compression molded article made from a blend of a) a polymer powder which is UHMWPE powder; b) ammonium polyphosphate in powder form; and c) chopped glass fibers; wherein the bulk volume percent fiberglass (BVPF) prior to molding is at least 27 percent of the volume of the polymer composition as molded, and wherein said molded composition exhibits no flame drip according to ASTM E-162.
Claim 11
Dependent Claim 36 words
The molded composition of claim 8, wherein the particle size of said UHMWPE powder is less than about 215 microns, and wherein the weight average molecular weight of said UHMWPE is at least about 21/2 million.
Claim 12
Dependent Claim 22 words
The molded composition of claim 9, wherein the particle size of the flame retardant additive (b) is less than about 50 microns.
Claim 13
Dependent Claim 21 words
The molded composition of claim 10, wherein the length of the chopped glass fibers (c) is less than about 1/4 inch.
Claim 14
Dependent Claim 24 words
The molded composition according to claim 8, including a thin fiber cloth or veil located on the top of said blend prior to molding.
Claim 15
Dependent Claim 27 words
The molded composition of claim 12, wherein said cloth or veil thickness is less than about 2 percent of the total thickness of said final molded composition.
Claim 16
Dependent Claim 167 words
A composite laminate for protecting a surface from impact damage, said composite laminate comprising; a first layer comprising; a) a polymer which is a high impact strength ultra-high molecular weight polyethylene (UHMWPE) which is free of halogen and cyanide or derivatives thereof on combustion; b) at least 4.40 percent by volume as molded of ammonium polyphosphate; and c) at least 6 percent by volume as molded of chopped glass fibers; wherein the maximum amount of component (b) in combination with component (c) as molded in an amount such that composition has a notched Izod impact strength of at least about 7 ft.lbs. per inch of width, wherein the bulk volume percent fiberglass (BVPF) prior to molding is at least about 27 percent of the volume of the polymer composition as molded, and wherein said polymer composition exhibits no flame drip according to ASTM E-162; an elastomeric second layer bonded to said first layer; and an optional fiber veil attached to said remaining side of said first layer.
Claim 17
Dependent Claim 167 words
A composite laminate for protecting a surface from impact damage, said composite laminate comprising; a first layer comprising; a) a polymer which is a high impact strength ultra-high molecular weight polyethylene (UHMWPE) which is free of halogen and cyanide or derivatives thereof on combustion; b) at least 4.40 percent by volume as molded of ammonium polyphosphate; and c) at least 6 percent by volume as molded of chopped glass fibers; wherein the maximum amount of component (b) in combination with component (c) as molded in an amount such that composition has a notched Izod impact strength of at least about 7 ft.lbs. per inch of width, wherein the bulk volume percent fiberglass (BVPF) prior to molding is at least about 27 percent of the volume of the polymer composition as molded, and wherein said polymer composition exhibits no flame drip according to ASTM E-162; an elastomeric second layer bonded to said first layer; and an optional fiber veil attached to said remaining side of said first layer.
Claim 18
Dependent Claim 142 words
The composite laminate of claim 14, wherein said composite laminate further comprises a third layer comprising: a) a high impact strength ultra-high molecular weight polyethylene (UHMWPE) polymer which is free of halogen and cyanide or derivatives thereof on combustion; b) at least 4.40 percent by volume as molded of ammonium polyphosphate; and c) at least 6 percent by volume as molded of chopped glass fibers; wherein the maximum amount of component (b) in combination with component (c) as molded is an amount such that composition has a notched Izod impact strength of at least about 7 ft.lbs. per inch of width, and wherein the bulk volume percent fiberglass (BVPF) prior to molding is at least 27 percent of the volume of the polymer composition as molded, said first layer and said third layer being bonded to opposite surfaces of said second layer.
Claim 19
Dependent Claim 23 words
The composite laminate of claim 14, wherein said elastomeric layer contains a flame retardant which does not generate halogen or cyanide upon pyrolysis.
Claim 20
Dependent Claim 17 words
The composite laminate of claim 14, wherein said flame retardant in the elastomer layer is alumina trihydrate.
Claim 21
Dependent Claim 11 words
The composite laminate of claim 14, wherein said elastomer is crosslinked.
Claim 22
Dependent Claim 74 words
A compression molded polymer composition having good flame retardancy and high impact strength, consisting essentially of: a) a high impact strength ultra-high molecular weight polyethylene; b) at least 4.40 percent by volume as molded of ammonium polyphosphate; and c) at least 6 percent by volume as molded of chopped glass fibers, wherein the bulk volume percent fiberglass prior to molding is at least 27 percent of the volume of the polymer composition as molded.
Claim 23
Dependent Claim 74 words
A compression molded polymer composition having good flame retardancy and high impact strength, consisting essentially of: a) a high impact strength ultra-high molecular weight polyethylene; b) at least 4.40 percent by volume as molded of ammonium polyphosphate; and c) at least 6 percent by volume as molded of chopped glass fibers, wherein the bulk volume percent fiberglass prior to molding is at least 27 percent of the volume of the polymer composition as molded.

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-02-14 1997-08-16 1998-02-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-02-14 2001-08-16 2002-02-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-02-14 2005-08-16 2006-02-15 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag