WO2000048831A1 - Structure stratifiee et son procede de fabrication - Google Patents

Structure stratifiee et son procede de fabrication Download PDF

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Publication number
WO2000048831A1
WO2000048831A1 PCT/US1999/003681 US9903681W WO0048831A1 WO 2000048831 A1 WO2000048831 A1 WO 2000048831A1 US 9903681 W US9903681 W US 9903681W WO 0048831 A1 WO0048831 A1 WO 0048831A1
Authority
WO
WIPO (PCT)
Prior art keywords
resin
structural laminate
laminate
prepreg layer
structural
Prior art date
Application number
PCT/US1999/003681
Other languages
English (en)
Inventor
Andrew N. Dion
Original Assignee
International Paper Company
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by International Paper Company filed Critical International Paper Company
Priority to CA002363041A priority Critical patent/CA2363041A1/fr
Priority to AU33043/99A priority patent/AU3304399A/en
Priority to PCT/US1999/003681 priority patent/WO2000048831A1/fr
Priority to MXPA01008430A priority patent/MXPA01008430A/es
Publication of WO2000048831A1 publication Critical patent/WO2000048831A1/fr

Links

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B15/00—Layered products comprising a layer of metal
    • B32B15/04—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material
    • B32B15/12—Layered products comprising a layer of metal comprising metal as the main or only constituent of a layer, which is next to another layer of the same or of a different material of paper or cardboard
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B29/00—Layered products comprising a layer of paper or cardboard
    • B32B29/06—Layered products comprising a layer of paper or cardboard specially treated, e.g. surfaced, parchmentised
    • E—FIXED CONSTRUCTIONS
    • E04—BUILDING
    • E04C—STRUCTURAL ELEMENTS; BUILDING MATERIALS
    • E04C2/00—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels
    • E04C2/02—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials
    • E04C2/26—Building elements of relatively thin form for the construction of parts of buildings, e.g. sheet materials, slabs, or panels characterised by specified materials composed of materials covered by two or more of groups E04C2/04, E04C2/08, E04C2/10 or of materials covered by one of these groups with a material not specified in one of the groups
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2311/00—Metals, their alloys or their compounds
    • B32B2311/24—Aluminium
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2311/00—Metals, their alloys or their compounds
    • B32B2311/30—Iron, e.g. steel
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2317/00—Animal or vegetable based
    • B32B2317/12—Paper, e.g. cardboard
    • B32B2317/125—Paper, e.g. cardboard impregnated with thermosetting resin
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2363/00—Epoxy resins
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B32—LAYERED PRODUCTS
    • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
    • B32B2605/00—Vehicles

Definitions

  • the invention relates generally to a structural laminate and a method of making the same and, more particularly, the invention relates to a metal-paper-metal structural laminate usefiil in vehicular trailer bodies and the like.
  • a structural laminate is described in International Publication No. WO 98/35114 dated August 13, 1998 (hereinafter the '" 114 publication”), the entire disclosure of which is incorporated herein by reference.
  • the '114 publication teaches that a structural panel can be prepared by laminating skins of sheet metal to a paper core.
  • the metal skins having a thickness of 5 mils to 12 mils are thicker than metal foils.
  • one laminate includes sequential layers of a first outer skin of sheet steel, a first adhesive layer, a kraft paperboard core, a second adhesive layer, and a second outer skin of sheet steel.
  • the kraft paperboard core is perforated and has a matrix of circular openings punched from the paper.
  • the openings define paths for adhesively bridging the outer metal skins to each other, where the adhesive bridges form columns of adhesive material oriented transversely to the adhesive layers and integrally connected to the adhesive layers. Without the bridging, the integrity of the laminate is susceptible to failure, in particular from a defect known as buckling, where the fibers in the paper core become separated and there is a local delamination of the paper.
  • the '114 publication further teaches the importance of the orientation of the paper in the laminates. Specifically, the laminates exhibit better performance (i.e., better stiffness and strength) characteristics when the machine direction of the kraft paper is aligned parallel to a neutral axis of bending than when the machine direction of the kraft paper is perpendicular to a neutral axis of bending.
  • the ' 114 publication discloses optionally impregnating a kraft paperboard core with a phenolic resin to improve performance.
  • the resin content of the core is in a range of 40 wt.% to 50 wt.%.
  • the present invention relates to an outdoor application wherein the product is riveted in place; hence, there are numerous sites for undesirable water penetration which can lead to corrosion and delamination. Therefore, it would be desirable to provide a structural laminate which, when exposed to various environmental conditions, does not corrode or delaminate. Furthermore, it would be desirable to provide a structural laminate with a high internal bond strength so that adhesive bridges are not needed. Additionally, it would be desirable to provide a laminate that is stronger and lighter than current aluminum products.
  • the invention provides a laminate formed of first and second metal skins with a resin-impregnated paper prepreg layer disposed between the metal skins.
  • the resin content of the prepreg layer is an effective amount of less than about 40 wt.%.
  • the invention provides a laminate formed of first and second outer metal skins, a middle structural layer disposed between the metal skins, and at least two resin-impregnated paper prepreg layers, one layer disposed between the middle structural layer and each metal skin.
  • the resin content of the prepreg layer is an effective amount of less than about 40 wt.%.
  • a method of preparing the structural laminate including the steps of impregnating a paper with a resin to prepare a prepreg layer, partially drying the prepreg layer to partially cure the resin, disposing the prepreg layer between first and second metal skins to form a structural laminate, and applying sufficient pressure and heat to the laminate to fully cure the resin.
  • Figure 1 is a schematic view of a structural laminate according to a preferred embodiment of the invention.
  • Figure 2 is a schematic view of a structural laminate according to another embodiment of the invention.
  • Figure 3 is a schematic depiction of a manufacturing process employed to prepare a structural laminate of the invention.
  • the invention is directed to a structural laminate comprising first and second metal skins, each having a thickness of preferably at least about 5 mils, and more preferably in a range of about 7 mils to about 8 mils.
  • the metal skins can each have a thickness of about 7.5 mils, and in another embodiment the metal skins can each have a thickness of about 20 mils.
  • the metal skins need not be the same thickness. Suitable metal skins include, but are not limited to, galvanized steel, standard steel, and aluminum.
  • a thermosetting resin-impregnated paper prepreg layer is disposed between the first and second metal skins. As used herein, reference to a prepreg layer includes, but is not limited to, at least one sheet of thermosetting resin-impregnated paper.
  • the laminate is formed of first and second metal skins, a middle structural layer, and at least two prepreg layers, one layer disposed between the middle structural layer and each metal skin.
  • the resin is present in the prepreg layer in an effective amount less than about 40 wt.%, preferably about 35 wt.%, based on the total weight of the prepreg layer.
  • Suitable resins include, but are not limited to, thermosetting resins selected from the group consisting of epoxy resins, phenolic resins, polyester resins, vinyl ester resins, and combinations thereof.
  • a method of preparing the structural laminate including the steps of impregnating a paper with a thermosetting resin to prepare a prepreg layer, partially drying the prepreg layer to partially cure the resin, disposing the prepreg layer between first and second metal skins to form a structural laminate, and applying sufficient pressure and heat to the laminate to fully cure the resin.
  • the invention is directed to a structural laminate, generally designated 10, formed of first and second metal skins 20 and 22, respectively, each skin having a thickness of at least about 5 mils (e.g., a thickness of about 7 mils to about 8 mils), and a thermosetting resin- impregnated paper prepreg layer 24 disposed between the first and second metal skins 20 and 22, respectively.
  • the prepreg layer can be of any suitable overall thickness, for example about 10 mils to about 210 mils.
  • the prepreg layer may be made of a plurality of paper sheets each having a thickness of about 10 mils to about 12 mils, for example.
  • the thermosetting resin-impregnated paper prepreg layer 24 illustratively includes two plies of 156 pound basis weight kraft paper obtained from Westvaco Corporation.
  • the paper preferably is illustratively immersed in an epoxy resin to apply a resin content in an effective amount less than about 40 wt.% based on the total weight of the prepreg layer.
  • the resin content is at least about 30 wt.%, more preferably in a range of about 32 wt.% to about 38 wt.%, and most preferably about 35 wt.%.
  • the paper is dried in an oven at varied temperatures depending on the type of oven used.
  • the paper is dried at temperatures ranging from about 200°F to about 365 °F, and more preferably about 315°F to about 365 °F.
  • the resin is only partially cured during this process, to help consolidate the laminate during the final press operation.
  • One epoxy resin that may be used to prepare the prepreg layer 24 is formed from bisphenol A-epichlorohydrin (a resin), dicyandiamide (a promoter), 2-methylimidazole (a catalyst), and methyl Cellosolve (a trademark of Union Carbide for an ethylene glycol monomethyl ether solvent).
  • a preferred bisphenol A-epichlorohydrin based epoxy resin solution can be obtained from Shell under the tradename Epon ® .
  • Dicyandiamide is a commercial product name for cyanoguanidine that can be obtained from SKW Trostberg AG, Germany.
  • 2-methylimidazole is a product name for 2-methyl- lH-imidazole that can be obtained from BASF Corporation in Parsippany, NJ.
  • the epoxy resin is preferably prepared by combining about 50 pounds of dicyandiamide, about 4000 grams of 2-methylimidazole, and about 650 pounds of methyl Cellosolve in a kettle. The mixture then is stirred under ambient conditions with a high speed sheer for about 20 minutes or until all of the dicyandiamide has dissolved. Next, about 1200 pounds of Epon ® resin solution are added to the mixture and the resultant mixture is stirred under ambient conditions with a high speed sheer for about 20 minutes.
  • the viscosity of the resulting epoxy resin is in a range of about 100 cps to about 300 cps, and more preferably about 150 cps to about 250 cps.
  • the specific gravity is in a range of about 1.04 to about 1.07, and a stroke cure is between about 50 seconds and about 90 seconds.
  • thermosetting resins such as phenolic resins, polyester resins, and vinyl ester resins can be used to impregnate one or more kraft paper sheets forming a part of the prepreg layer.
  • the resin content when using a phenolic resin may be reduced from that preferred for other, e.g., epoxy, resins.
  • the phenolic resin content is preferably at least about 25 wt.%, based on the total weight of the prepreg layer.
  • a glue line or another epoxy prepreg layer can be added adjacent to the metal skins to assist in bonding the metal skins to the prepreg layer(s).
  • a phenolic resin-impregnated paper prepreg layer cannot be placed between the metal skins without an adhesive layer because it will not bond to the metal skins.
  • the resin may consist essentially of, or consist of, an epoxy resin because it provides improved moisture resistance, bond strength, and consolidation of the laminate.
  • the prepreg layer 24, once partially cured, is then prebuilt with the metal skins 20 and 22, respectively.
  • the metal skins 20 and 22, respectively preferably are formed of a metal selected from the group consisting of galvanized steel, standard steel, and aluminum.
  • galvanized steel skins are used, each having a thickness of at least about 5 mils.
  • the resulting thickness of the laminate 10 can be varied by using different numbers of prepreg layers 24.
  • the resulting total thickness of the laminate 10 can be up to about 2 inches, for example.
  • the metal skins each have a thickness of about 7.5 mils, so that the resulting thickness of the laminate 10 will be about 35 mils.
  • the prepreg layer 24 and metal skins 20 and 22 are then pressed at about 600 psi and heated to about 165 °C for about 65 minutes to form the laminate 10.
  • the laminate 10 is then cooled for about 30 minutes.
  • the metal skins 20 and 22 each having a thickness of about 19 mils are disposed on either side of the prepreg layer 24 to form the laminate 10.
  • the resulting thickness of the laminate 10 can be varied by using different numbers of prepreg layers 24.
  • the resulting thickness of the laminate 10 using metal skins 20 and 22 having thicknesses of about 19 mils will be about 250 mils.
  • a middle structural layer 30 is disposed between the metal skins 26, and at least two thermosetting resin- impregnated paper prepreg layers 28 are disposed between the middle structural layer 30 and the metal skins 26 to form the laminate 12.
  • the middle structural layer 30 can be formed of a woven glass cloth, which would improve the impact and puncture resistance of the laminate 12.
  • the resulting thickness of the laminate 12 can be varied by using different numbers of prepreg layers 28. Preferred thicknesses of the metal skins 26 and the middle structural layer
  • An epoxy resin is obtained from a chemical source represented by an element 32 and then placed in a treating apparatus 34.
  • Rolls of kraft paper 36 are immersed in an epoxy resin bath, the resin content is metered using squeeze rolls 37, and then the paper is partially dried in one continuous process in an apparatus represented by element 38 to prepare prepreg layers 39.
  • the prepreg layers 39 are then cut to a desired length at 40 and prebuilt at 42 with metal skins 43.
  • the prepreg layers 39 and metal skins 43 are subjected to pressure and heat as shown by a molding process 44.
  • After the molding process 44 a structural laminate 46 is formed.
  • the structural laminate 46 then undergoes shearing 48, inspection 50, and packaging 52.
  • This manufacturing process is by way of illustration only and is not intended to be limited to only those manufacturing steps disclosed.
  • the resulting laminate of the invention has superior water resistance and good adhesion to the galvanized steel.
  • a surprising result in the development is the good adhesion of the galvanized steel to the epoxy/paper prepreg in light of the inherent difficulty when laminating to a galvanized coating.
  • both standard steel and aluminum could be used to form the laminate, the laminate with the galvanized steel is stronger, lighter, and lower in cost.

Landscapes

  • Engineering & Computer Science (AREA)
  • Architecture (AREA)
  • Civil Engineering (AREA)
  • Structural Engineering (AREA)
  • Laminated Bodies (AREA)

Abstract

L'invention concerne une structure stratifiée et son procédé de fabrication. Ce stratifié est composé d'une couche thermodurcissante préimprégnée en papier imprégné de résine située entre une première et une deuxième peaux métalliques rendues résistantes sous l'effet de chaleur et de pression. Ces peaux métalliques, possèdent, de préférence, une épaisseur d'au moins 5 mm et, dans un mode de réalisation préféré, de 7,5 mm. On prépare la couche préimprégnée par imprégnation de papier au moyen d'une résine, de préférence, une résine époxy. On applique cette résine, de façon à être présente dans la couche préimprégnée en une quantité inférieure à 40 % en poids, de préférence, 35 % en poids, par rapport au poids total de la couche préimprégnée.
PCT/US1999/003681 1999-02-19 1999-02-19 Structure stratifiee et son procede de fabrication WO2000048831A1 (fr)

Priority Applications (4)

Application Number Priority Date Filing Date Title
CA002363041A CA2363041A1 (fr) 1999-02-19 1999-02-19 Structure stratifiee et son procede de fabrication
AU33043/99A AU3304399A (en) 1999-02-19 1999-02-19 Structural laminate and method of making the same
PCT/US1999/003681 WO2000048831A1 (fr) 1999-02-19 1999-02-19 Structure stratifiee et son procede de fabrication
MXPA01008430A MXPA01008430A (es) 1999-02-19 1999-02-19 Laminado estructural y metodo para fabricarlo.

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/US1999/003681 WO2000048831A1 (fr) 1999-02-19 1999-02-19 Structure stratifiee et son procede de fabrication

Publications (1)

Publication Number Publication Date
WO2000048831A1 true WO2000048831A1 (fr) 2000-08-24

Family

ID=22272217

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/US1999/003681 WO2000048831A1 (fr) 1999-02-19 1999-02-19 Structure stratifiee et son procede de fabrication

Country Status (4)

Country Link
AU (1) AU3304399A (fr)
CA (1) CA2363041A1 (fr)
MX (1) MXPA01008430A (fr)
WO (1) WO2000048831A1 (fr)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001012434A1 (fr) * 1999-08-12 2001-02-22 Dofasco Inc. Panneau structurel ameliore et procede de fabrication
DE102004037398A1 (de) * 2004-07-30 2006-03-23 Fritz Egger Gmbh & Co Schichtstoff, Bauteil mit einem Schichtstoff sowie Verfahren zu dessen Herstellung
US7204906B2 (en) * 2001-04-20 2007-04-17 Dofasco Inc. Method for laminating and forming a composite laminate in a single operation
WO2016041895A1 (fr) * 2014-09-17 2016-03-24 Basf Coatings Gmbh Composant stratifié extérieur de véhicule automobile et son procédé de formation

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1579770A (fr) * 1967-09-06 1969-08-29
GB2148793A (en) * 1983-10-07 1985-06-05 Sanyo Kokusaku Pulp Co Process for the production of laminated sheet
WO1998035114A1 (fr) * 1997-02-10 1998-08-13 Dofasco Inc. Panneau structural comprenant un noyau en papier kraft entre des enveloppes metalliques

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR1579770A (fr) * 1967-09-06 1969-08-29
GB2148793A (en) * 1983-10-07 1985-06-05 Sanyo Kokusaku Pulp Co Process for the production of laminated sheet
WO1998035114A1 (fr) * 1997-02-10 1998-08-13 Dofasco Inc. Panneau structural comprenant un noyau en papier kraft entre des enveloppes metalliques

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2001012434A1 (fr) * 1999-08-12 2001-02-22 Dofasco Inc. Panneau structurel ameliore et procede de fabrication
US7204906B2 (en) * 2001-04-20 2007-04-17 Dofasco Inc. Method for laminating and forming a composite laminate in a single operation
DE102004037398A1 (de) * 2004-07-30 2006-03-23 Fritz Egger Gmbh & Co Schichtstoff, Bauteil mit einem Schichtstoff sowie Verfahren zu dessen Herstellung
DE102004037398B4 (de) * 2004-07-30 2011-06-22 Fritz Egger Gmbh & Co. Holzwerkstoffplatte mit einem Schichtstoff und Verfahren zur Herstellung eines Bauteils mit einer Holzwerkstoffplatte
WO2016041895A1 (fr) * 2014-09-17 2016-03-24 Basf Coatings Gmbh Composant stratifié extérieur de véhicule automobile et son procédé de formation

Also Published As

Publication number Publication date
CA2363041A1 (fr) 2000-08-24
MXPA01008430A (es) 2003-06-06
AU3304399A (en) 2000-09-04

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