WO1989005833A1 - Materiaux composites, leur preparation et articles fabriques a partir de ces materiaux - Google Patents

Materiaux composites, leur preparation et articles fabriques a partir de ces materiaux Download PDF

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Publication number
WO1989005833A1
WO1989005833A1 PCT/US1987/003440 US8703440W WO8905833A1 WO 1989005833 A1 WO1989005833 A1 WO 1989005833A1 US 8703440 W US8703440 W US 8703440W WO 8905833 A1 WO8905833 A1 WO 8905833A1
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WIPO (PCT)
Prior art keywords
percent
composite material
web
sheet
bits
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Application number
PCT/US1987/003440
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English (en)
Inventor
Max Klein
Original Assignee
Matcom, Inc.
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
Priority claimed from US06/796,929 external-priority patent/US4716062A/en
Application filed by Matcom, Inc. filed Critical Matcom, Inc.
Priority to PCT/US1987/003440 priority Critical patent/WO1989005833A1/fr
Priority to JP50209688A priority patent/JPH03503058A/ja
Publication of WO1989005833A1 publication Critical patent/WO1989005833A1/fr

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    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
    • C08J11/00—Recovery or working-up of waste materials
    • C08J11/04—Recovery or working-up of waste materials of polymers
    • C08J11/06—Recovery or working-up of waste materials of polymers without chemical reactions
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H25/00—After-treatment of paper not provided for in groups D21H17/00 - D21H23/00
    • D21H25/04—Physical treatment, e.g. heating, irradiating
    • D21H25/06—Physical treatment, e.g. heating, irradiating of impregnated or coated paper
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H27/00—Special paper not otherwise provided for, e.g. made by multi-step processes
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
    • Y02W30/00—Technologies for solid waste management
    • Y02W30/50—Reuse, recycling or recovery technologies
    • Y02W30/62—Plastics recycling; Rubber recycling

Definitions

  • the present invention relates to composite materials, their method of preparation, as well as aqueous dispersions and paper-like sheets or webs used in said method, and to composite structures and articles made from the composite materials.
  • composite material refers to combinations of two or pore materials, in sheet or web form, comprising a continuous matrix phase which surrounds a reinforcing phase composed of discrete reinforcing elements.
  • Composite materials are used in the manufacture of a wide variety of articles including automotive springs, brake pads, chemical processing equipment, air foils and fuselage structures for aircraft, helicopter blades, boat hulls, and sporting goods, such as golf clubs (shafts), baseball bats, skis and tennis rackets (frame).
  • Such structures are commonly produced using so-called continuous fiber methods of fabrication, in which the composite material must be carefully consolidated by means of pressure and vacuum to eliminate porosity and insure complete coalescence of the matrix phase, so as to avoid non-homogeneity in the final product.
  • These fabrication methods often require specialized equipment which adds to the capital expenditure and operating cost involved in manufacturing such structures.
  • composite materials have reportedly been prepared from solid polymer, reinforcing material and a latex binder by an aqueous method employing conventional paper-making equipment and processes. See, for example, U.S.
  • Patent 4,426,470 which specifically describes the preparation of composite sheets using high density polyethylene as the solid polymer, glass fibers as the reinforcing material, and various latex binders of substantially water-insoluble organic polymers having either anionic or cationic bound charges.
  • the aqueous slurries reportedly used in producing composite materials by paper-making techniques must be carefully formulated in order to obtain a satisfactory product. Special care must be taken to avoid accumulation of loose powdered polymer or resin on the surface of the paper-like web from which the composite material is prepared.
  • the finished mat is unusually brittle; and when a neutral dispersion aid, such as LubrizolTM or KatapolTM is employed. and the composite material is converted to a laminated product, individual plies of the product tend to peel apart.
  • a neutral dispersion aid such as LubrizolTM or KatapolTM
  • composite materials can be efficiently produced using paper-making technology, by including polymer micro-bits in the heat fusible sheet or web from which the composite material is prepared.
  • the polymer micro-bits substantially eliminate accumulation of powdered polymer or resin on the sheet or web, and serve to maintain all of the components of the composite material uniformly distributed throughout the final product.
  • Use of the polymer micro-bits also effectively eliminates the occurrence of edge bleeding.
  • composite material in the form of a sheet or web comprising a continuous matrix phase which surrounds a reinforcement phase composed of discrete reinforcing elements, the continuous matrix phase comprising heat fused polymer micro-bits produced from an expanded, hydrophobic, thermoplastic polymer which is non-brittle in expanded form, the polymer micro-bits being substantially free of intact cells of the expanded or foamed polymer from which they are produced.
  • composite materials have a variety of applications, including, but not limited to, furniture board/ grinding wheels, low friction bearings and packings, bullet-proof shields, and a variety of sporting equipment.
  • composition of matter in the form of a uniform aqueous dispersion including the aforesaid polymer micro-bits and one or more reinforcing elements for the composite material, which composition is used as the furnish for the preparation of the composite material, using conventional paper-making equipment and processees.
  • Aqueous dispersions containing the polymer micro-bits enable the formation of consistently uniform, heat fusible sheets or webs which are readily converted into the finished composite material.
  • the heat fusible sheets or webs, formed in an intermediate stage of composite material production, constitute a further aspect of the present invention.
  • a process for the production of the aforementioned composite material which comprises forming a wet sheet or continuous web of the disperse phase of the above-mentioned aqueous dispersion, drying the sheet or web and heating the sheet or web sufficiently to transform the polymer micro-bits to a continuous matrix phase surrounding the reinforcing elements, thus yielding the composite material.
  • composite material having a number of desirable properties, including thermoformability, relatively light weight, high strength, dimensional stability and resistance to deformation. These characteristics are maintained over wide variations in temperature and humidity.
  • the composite materials of this invention are also extremely resistant to water absorption.
  • the principal components of the composite materials are polymer micro-bits and finely divided, hydrophobic, thermoplastic resin, which go into the matrix phase, and at least one reinforcing element constituting the reinforcing phase. Additional components, such as a binder, may be used in fabricating the composite material, as will be described below.
  • the Matrix Phase generally constitutes from about ten to about seventy percent by weight of the finished composite material.
  • the polymer micro-bits component of the matrix phase is produced from any expanded, hydrophobic, thermoplastic polymer, which is non-brittle in expanded form.
  • a significant characteristic of the polymer micro-bits is that they are substantially free of intact cells of the expanded polymer starting material from which they are produced.
  • the starting material for the polymer micro-bits is selected from the group of non-brittle, expanded, hydrophobic, thermoplastic styrene polymers, lower polyolefins, or co-polymers or blends of such polymers.
  • the lower polyolefins may be derived from any ethylenically unsaturated hydrocarbon monomer having from 2 to 6 carbon atoms, e.g. polyethylene, polypropylene, polybutylene or polymethylpentene.
  • non-brittle as used herein, is intended to signify that the polymer starting materials are relatively flexible, generally having a density of five pounds/cubic foot, or less. S.tyrene-polymers whose density is from one or two pounds/cubic foot are especially suitable for the production of micro-bits. Micro-bits of expanded, hydrophobic, thermoplastic styrene-polymers or lower polyolefins are more fully described, along with their process of preparation, in my U.S.
  • the micro-bits are prepared by disintegrating the polymer starting material, in the form of expanded polymer bit pieces, using a comminuting machine such as the one described in my aforementioned U.S. Patent No. 4,207,378 (column 4, line 22 to column 5, line 35).
  • the resultant micro-bits in addition to being substantially free of intact cells of the expanded polymer from which they are produced, typically also have the following characteristics: (a) particle size range from about 40 to about 325 microns long, from about to 20 to about 320 microns wide and about 0.5 microns thick, (b) shape which is substantially non-uniform in outline, and (c ) density which is about 85 percent or more of the density of the specific unexpanded polymer from which the expanded polymer starting material is produced.
  • the surface area of the polymer micro-bits is approximately six square meters per gram.
  • the micro-bits When viewed under a scanning election microscope (SEM), magnified to 1000 times actual size, the micro-bits have the appearance of a crumpled sheet of paper, marked by irregular undulations and having numerous wrinkles, creases and folds. Examination by SEM also reveals what appears to be extended apart and distorted outlines of ruptured boundaries of what before disintegration was an expanded honeycomb array of regular geometrical cross sections of cells.
  • SEM scanning election microscope
  • the polymer micro-bits facilitate preparation of the aqueous dispersion from which the composite material is made.
  • the micro-bits serve as a dispersion aid, helping to uniformly distribute the solid components of the composite throughout, and maintaining the stability of, the aqueous dispersion.
  • micro-bits Even low specific gravity powdered resins, such as polyolefins and polycarbonates are uniformly distributed and maintained in suspension by the micro-bits.
  • the polymer micro-bits also serve to retain in the heat-fusible, paper-like sheet or web the solid components from which the sheet or web is made.
  • Approximately twenty to one hundred weight percent of the matrix phase may be polymer micro-bits.
  • the micro-bits preferably constitute from about twenty to about sixty weight percent of the matrix phase.
  • polystyrene is generally regarded as a relatively brittle material which is not particularly suited for use in composite formulations.
  • polyethylene and/or polycarbonate which are commonly used in composite formulations, are incompatible with polystyrene because a melt mixture of these polymers would be deficient in important physical properties including tensile, impact and flexual strength, as well as heat resistance. The inclusion of reinforcing elements in such a resin mixture would tend to further adversely affect those properties.
  • the matrix phase may also include various finely divided, hydrophobic, heat fusible resins.
  • polycarbonates include polycarbonates, polyolefins, including low and high molecular weight polyethylene and polypropylene and co-polymers thereof, polyester, nylon, polyacetals, chloropolymers, including chlorinated ethylene and polyvinyl chloride, fluoropolymers, including polytetrafluoroethylene, acrylic resins, acrylonitrile-butadiene-styrene (A.B.S.) polymers and the like. Polymer blends or melt alloys of the foregoing polymers may also be used if desired. These resins are finely divided to particle size in the range of 1 to 425 microns. These thermoplastic, heat fusible resin powders, when used, may constitute up to about seventy weight percent of the matrix phase.
  • the resin powder component of the matrix phase is in the range of about forty to about seventy weight percent. In general, at least ten percent by weight of polymer micro-bits, based on the total weight of the matrix is required to achieve a high loading (sixty weight percent or higher) of the resin powder.
  • the reinforcement phase normally constitutes about thirty to about ninety percent by weight of the finished composite material.
  • the reinforcing elements that make up the reinforcement phase may be in fibrous or particulate form.
  • the fibrous reinforcing elements may be selected from the group of glass, carbonaceous, polymer (both natural and synthetic), inorganic, and metal fibers.
  • the fibrous reinforcing elements are preferably cel lulosi c materials , such as hard wood pulp f ibers , or mixtures of fiber-containing pulps, produced as a waste product of paper making operations. These pulps generally have a freeness of 350 or less.
  • Other cellulosic fibers which may be used included those derived from semi-refined plant material, e.g.
  • Fibers having utility in the practice of this invention are obtainable from source materials which otherwise have no practical utility.
  • These fibrous reinforcing elements are preferred because they yield light weight, high strength composites at relatively low cost. It is preferable to include glass micro-fibers in the composite material for strength enhancement.
  • Synthetic polymer fiber reinforcing elements impart desirable qualities to the finished composite material, but are more expensive than the pulp fibers mentioned above. Satisfactory composites have been obtained using aromatic polyamide and/or polytetrafluoroethylene (PTFE) fibers.
  • PTFE polytetrafluoroethylene
  • Composites containing Kevlar® fibers, for example have been found to have exceptional physical properties, including very high strength and heat resistance. Composites having good physical properties and excellent high temperature resistance have also been obtained using Nomex® fibers, which are formed from a copolymer of meta-phenylenediamine and isophthaloyl chloride.
  • Suitable nylon fiber lengths are from about .5 cm. to about 1.5 cm.
  • the cellulosic fibers may be cotton fibers, e.g. cotton linters or cellulose fibers from other sources, such as woodpulp from both soft and hard woods.
  • the "cobeat” is so named because, after forming a uniform dispersion of the cellulose fibers and polymer micro-bits in a paper-making pulper, for example, the dispersion is fed into a beater and subjected to beating action until its freeness is within the range of about 400 to about 450.
  • Freeness is generally understood by those skilled in the art to be a measure of the rate of flow of water through a pulp and is determined in accordance with Tappi Standard T227-m-58 (also referred to as Canadian Standard Freeness). The higher the freeness value, the higher the rate of flow of water through the pulp.
  • a relatively minor amount of one or more non-shrinkable, fiber-forming polyester, preferably polyester terephthalate fibers, e.g. Trevira® 101, may be included in the cobeat in order to enhance the wet tear strength of the paper-like elements from which the composite material is fabricated.
  • the cobeat preferably is composed of about 35 to about 50 weight percent of polymer micro-bits and from about 50 to about 65 weight percent cellulose fiber, with the polyester, when used, constituting up to about seven percent of the total of the cellulose fiber and micro-bits.
  • the cobea t dispersion may be used as is , or it may be converted to a continous web using conventional paper-making processes and apparatus, the latter being preferred. After adequate drying, the cobeat web becomes a storable product which is available when required for making the composite material.
  • the cellulose fibers and polyester fibers may be added separately in preparing the furnish, if desired. The procedure for preparing the cobeat is described in detail in Example 1 of my U.S. Patent No. 4,293,378, the entire disclosure of which is incorporated in the present application by reference, as if set forth herein in full.
  • cobeat aids in forming a uniform, homogeneous aqueous dispersion of the composite components.
  • the cobeat also serves to enhance retention of particulate components of the web or sheet material when present therein.
  • the particulate reinforcing elements may be selected from the group of diatomaceous earth, polyurethane micro-bits, aluminum oxide, wood flour, saw dust, carbon powder, (including finely divided graphite), silicon dioxide, calcium carbonate, mica, various low cost clays, and the like.
  • a commercially available diatomaceous earth which may be used advantageously in the present invention is supplied by the Manville Corporation under the name "Hi-Flow Supercel", which has a median particle size of 18 microns, a median pore size of 7 microns, and a softening point of 982°C.
  • the diatomaceous earth is believed to assist in uniformly dispersing the resin powder in the furnish and in checking the occurrence of edge bleeding during heat fusing of sheets of the composite material.
  • Composite materials made in accordance with the present invention may also contain a variety of other components for imparting properties that are beneficial during wet web or sheet formation or in the finished product, or both.
  • non-fibrilated fibers e.g., glass fibers
  • the compatible binding agent is employed in an amount effective for binding the points of contact of the fibrous components of the composite material.
  • the binding agent should be insoluble in cold water, soluble in hot water, and retain its binding action upon cooling.
  • a suitabled organic binding agent satisfying these criteria is polyvinyl alcohol (PVA).
  • PVA fibers to achieve uniform dispersion of the components in the furnish used in making the composite material.
  • PVA is essentialy insoluble in cold water but tends to quickly dissolve in water at temperatures above 140°F and this property may be used to advantage during production of the composite material.
  • the solubilized polyvinyl alcohol tends to flow to the points of contact between the fibers, and accumulate there so that when the paper-like element is completely dried, the solid PVA binds the fibers of the sheet material together. It has been found that the addition of PVA fiber, in an amount up to seven percent by weight of the other solid components of the composite material, provides the desired binding effect. If the PVA is used in amounts in excess of seven percent, the resultant composite is undesirably stiff and has a
  • Another component which may optionally be included in the composite material is malamine-formaldehyde resin, which serves as a supplemental binding agent.
  • the malamine-formaldehyde resin is advantageously used in conjunction with the above-described cobeat.
  • Melamine-formaldehyde resin suitable for use in the present invention is of the type described in U.S. Patents Nos. 2,345,543 or 2,559,220, which is prepared by the condensation of melamine and formaldehyde in an aqueous acid medium. Resin of this type are available from Pioneer Plastics, Division of LOF Plastics, Inc., as an aqueous dispersion having 11% solid content.
  • the amount of melamine-formaldehyde resin to be used in the combustible sheet material is generally less than three percent by weight of the other solid components of the composite material.
  • the melamine-formaldehyde resin reacts with the cellulose fiber component of the cobeat to form stable linkages, which provide a high degree of wet strength to the web or sheet.
  • the melamine-formaldehyde resin is non-ionic at the pH of the aqueous dispersion, which is about 7.5 to about 8.5.
  • a further optional component is an adhesive, elastomeric, colloidal latex, employed in an amount effective for improving retention of any particulate component during wet web or sheet formation and imparting flexibility to the finished paper-like element.
  • the adhesive latex preferably has a solids content ranging from about 35 to about 55 percent and an average particle size of about 0.2 microns. It is non-ionic at a pH of 7.5 to 8.5.
  • a suitable adhesive, elastomeric, colloidal latex for use in practicing the present invention is an aqueous dispersion having a 50% solids content made by B. F. Goodrich Company, and sold under the name "Hycar 2671".
  • the adhesive latex also serves to offset the stiffening effect produced by the organic binder.
  • siloxane polymer may also be included in the composite material, if desired.
  • the amount of siloxane polymer employed should be sufficient for aiding in the retention of any particulate component during wet web or sheet formation and in removal of the wet web or sheet from the porous support on which it is formed.
  • siloxane polymer refers to a linear chain structure of the general formula:
  • R 1 is lower alkyl, preferably methyl and R 2 is lower alkyl or hydroxyl and n is equal to approximately 150.
  • siloxane polymer also included with the term “siloxane polymer” are derivates thereof substituted with various functional groups, such as aminoalkyl groups.
  • the siloxane polymer has a solid content of approximately 30 percent and is non-ionic at a pH of 7.5 to 8.5.
  • siloxane polymer in the form of an aqueous emulsion containing 30% solids, which is available from SUS Chemical Company, under the trade name " ⁇ scosoft AF".
  • This product contains a functional amine derived from ethylenediamine in which one nitrogen is attached to a silicon atom of the polymer chain in the above formula.
  • the siloxane polymer significantly aids in the release of the wet web from the porous support and improves particle retention during formation of the wet web.
  • the siloxane polymer is also effective in providing additional binding effect in conjunction with the binding agent.
  • antioxidants such as antioxidants, pigments, oxidizing agents, e.g. ammonium, sodium or potassium perchlorate and/or powdered aluminum oxide, bacteriocides, electromagnetic radiation absorption agents, fire retardants and the like may also be used, if desired.
  • oxidizing agents e.g. ammonium, sodium or potassium perchlorate and/or powdered aluminum oxide, bacteriocides, electromagnetic radiation absorption agents, fire retardants and the like may also be used, if desired.
  • the aqueous dispersion used in making the composite material of the present invention is conveniently prepared in a standard paper-making beater or similar mixing apparatus. Best results are obtained when a small amount of cobeat (on the order of from about two to six percent of the total disperse phase) is first added to the mixing apparatus, followed by the polymer micro-bits, and then the remaining components in any desired order. As previously noted, the cobeat facilitates formulation of a uniform aqueous dispersion of the composite components.
  • the mixing time should be sufficient for obtaining a uniform dispersion, which normally requires about one to twenty minutes, depending on the formulation of the dispersion.
  • Conversion of the aqueous dispersion to a heat fusible sheet or web may be accomplished using conventional flat, slant-wire or cylinder-type paper making apparatus, i.e. those equipped with fourdrinier wires, cylinder molds, or combined machines including both fourdrinier wires and cylinder molds.
  • the process ordinarily involves thorough homogenization of the dispersion in a mixing chest to insure uniformity, application of the homogenized dispersion to a porous substrate (usually an endless belt) to form the web or sheet, removal of the web or sheet from the porous substrate, and drying thereof.
  • the drying step may include the application of pressure to the web or sheet to express water therefrom.
  • the furnish should be applied to the forming surface of the paper-making machine at a rate of about 20 pounds to 150 pounds per 1300 square feet of finished material, depending on the drainage and drying capacity, which depends, in turn, on the composition of the material.
  • Individual sheets may be made using an ordinary sheet mold.
  • the finished web is normally passed over an open flame, high-pressure, steady heated drums and through a hot-air tunnel for drying.
  • the temperature required for drying of the web (or sheet) is normally in the range of about 275°F to about 475°F.
  • the final water content of the web or sheet should be less than about three percent, if cellulose is present, or less than about one percent if no cellulose is present.
  • Heat fusion of the sheet or web to produce the finished composite material may be carried out using heated platens or heated calenders operated at about 4000 to 6000 pounds pressure. Heating of the sheet or web at a temperature of about 430°F for about fifteen to thirty seconds will usually be sufficient to cause the polymeric or resin component of the web or sheet to fuse. Slightly higher temperatures may be employed for shorter times, e.g. 440°F for ten to fifteen seconds and vice versa. Of course, optimum conditions for heat fusion will depend on the thickness and composition of any particular sheet or web and may be emperically determined.
  • a plurality of individual sheets of the composite material may be heat fused to provide a monolithic stock material which may be converted by appropriate forming operations into various composite structures.
  • Solid and hollow core panels may be easily prepared by the present invention.
  • a void or hollow space is. obtained by stamping out the central or interior portion of an appropriate number of the intermediate plies of composite material used in forming the finished product. The conditions for heat fusion are essentially the same as those described about with respect to the individual sheets or webs.
  • any forming or machining operations are to be carried out on the composite material, e.g. die cutting, optimum efficiency is achieved by conducting such operations immediately after heat fusion, i.e. while the material is in a heated condition.
  • Composite materials containing PTFE fibers have an extremely low coefficient of friction and are especially suited for the packing of shafts, e.g. pump shafts, notwithstanding the relative rigidity of the material.
  • a suitable material for this purpose is exemplified below.
  • the low friction coefficient of the material facilitates cutting in the form of an annulus, which may be severed at a single point or split into two semi-circles to allow for insertion around a shaft.
  • Polystyrene micro-bits Micro-bits prepared as described in Example 1 of my U.S. Patent No. 4,207,378
  • Polyethylene powder Hostalen® GUR 412
  • Polycarbonate resin Lexan® (average powder particle size 275 microns)
  • Cobeat Blend of polystyrene micro-bits and cellulose fiber prepared as described in Example 1 of my U.S.
  • Glass fiber DE-636 (Owens-Corning);
  • Stainless steel fibers 3/16" long, 4 micron diameter fiber (dimensions designed by manufacturer, N.V. Bekaert S.A.)
  • Polyvinyl alcohol Kuralon 105-2 (fiber binder form); 4mm long
  • Melamine-formaldehyde Piomide; product of resin Pioneer Plastics, Auburn, Maine; 11% aqueous dispersion
  • Adhesive latex Hycar 2671 aqueous emulsion of mixed acrylic polymers, 50% total solids
  • Carbon particles Electrodag 230, fine particle carbon; 25% solid dispersion with density of 1.11 kg. /1.
  • EXAMPLE 1 An aqueous dispersion or furnish was prepared by adding the following components to 12 liters of water in a 5 gallon plastic container. Components Amounts (dry wt. in gms.)
  • the aqueous dispersion was stirred using an air driven three-bladed propeller-type stirrer for about twenty minutes prior to taking aliquots for sheet preparation.
  • Sheets were made from the foregoing furnish in a standard twelve inch by twelve inch sheet mold. In preparing the sheets 2500 ml. aliquots of the aqueous dispersion were added to approximately 8 gallons of water in the sheet mold. At least five uniform sheets were prepared, which exhibited no releasable polymer or resin component on the surface thereof. One of the sheets was dried by heating to a temperature of 240-260° in a photographic sheet dryer and cut into 6 pieces, each measuring four inches by five inches. Two of the cut pieces were superimposed on one another and subjected to a temperature of 430° and a compressive force of 6000 pounds in a platen press for about 30 seconds.
  • the heat fusion cycle was repeated as the remaining pieces of composite material were added to the previously fused sheets, so that all six were fushed together to form a solid, monolithic block of high strength stock material, the composition of which was uniform throughout. No individual plies of the composite material were noticeable in the finished product, the polymer component having become thoroughly fused .
  • sample sheets were prepared from an aqueous dispersion which was essentially the same as that just described, but contained no polymer micro-bits.
  • the exposed surface of the resultant sheet i.e. the surface not facing the mold screen, was covered with loose polyethylene powder, which was readily released from the dry sheets.
  • Additional composite materials of the present inventions were prepared from the furnishes described in Table I below.
  • the resulting paper-like sheets were hot pressed according to the general conditions described hereinbelow.
  • thermoformable glass-resin paper was prepared from the following furnish, which was mixed in ten liters of water in a five gallon container. Components Amounts (dry wt. in gms.)
  • the above furnish was reformulated by including 100 grams of low molecular fine polyethylene powder powder (Dow Chemical Co.) and 30 added grams of DE glass fiber. Hand sheets were made and hot pressed under the same conditions as just described. The composite material thus produced exhibited no cracking tendency upon folding or creasing.
  • EXAMPLE 13 An aqueous dispersion was prepared from the following components using the same general procedure described in Example 1 above, except that the dispersion was mixed in 14 liters of water.
  • Components Amounts dry wt. in gms.
  • Aromatic polyamide fiber 5 Aromatic polyamide fiber 5
  • the cellulosic fiber used in the present example was in the form of a sludge produced as a waste product in paper-making.
  • the sludge was obtained from Crane & Co., Dalton, Massachusetts on October 25, 1985.
  • the composition of paper-making sludge is subject to wide variation and is extremely difficult to determine. The composition on any given day depends on the type of paper produced in the mills in operation on that day.
  • the sludge used in this example contained primarily cellulose fiber, with a relatively minor amount of glass fiber and other additives normally used in paper-making. Because of its poor drainage rate, paper-making sludge cannot be recycled economically, and is usually discarded.
  • Sheets were made from 3000 ml. aliquots of the furnish of this example by the procedure described in Example 1 above. The wet laid sheets exhibited good drainage and wet strength. A composite block composed of twenty plies of the resulting sheet material, and measuring 5" ⁇ 5" ⁇ 11/32" in finished form, was prepared according to the hot pressing procedure described in Example 1, under the following conditions: 6000 lbs. pressure; 25 seconds; 435°F. The finished block weighed 135 gms. EXAMPLE 14
  • a low cost, high strength composite was prepared from a hardwood pulp.
  • a cobeat was prepared by heating together 1400 gms. of hardwood Oxybrite Craft and .600 gms. of polystyrene micro-bits in 67 liters of water following the general procedure described above. After beating for approximately one hour and fifteen minutes, the freeness of the cobeat decreased to 600, from a initial value of 850. The cobeat had a solids content of about 3%.
  • a furnish was prepared by adding 300 ml. of the resulting cobeat (approx. 9 gms. dry weight) to 14 liters of water in a 5 gallon container, after which the following components were added: Components Amounts (dry wt. in gms.)
  • Sheets were made from 3000 ml. aliquots of the furnish of this example by the procedure described in Example 1, above. The sheets retained considerable water, but could be coverted to composite materials nonetheless.
  • Cereal grasses such as the rice straw employed in Example 5 must be at least partially refined to provide fibers suitable for incorporation into a composite material.
  • Rice straw has a composition of about 20% silica, 30% lignin, 20% soluble hemi-cellulose and about 30% fibrous cellulose available for paper-making. It has been found that rice straw processed in a conventional beater as described in this example, yields fiber suitable for use in a composite formulation.
  • the stainless steel fibers used in the composite of Example 11 were processed in a ball mill in order to impart thereto the necessary degree of dispersability for formulating the furnish.
  • a standard laboratory ball mill having a 1.7 liter capacity were placed 10 grams (dry weight) of polystyrene micro-bits, 40 grams of the stainless steel fiber, about 1.3 liters of water, and approximately equal amounts of steel balls (measuring 1 in. or 1/2 in. in diameter) and ceramic cylinders (measuring 1/2" in length and 1/2" around), so as to fill approximately 75 percent of the capacity of the ball mill.
  • the micro-bits were used as a milling aid. If the micro-bits are not used, metal fibers agglomerates are produced. After running the mill for about one day, a uniform aqueous dispersion of the stainless steel fibers was obtained, which could be used directly for making the furnish for the stainless steel fiber-containing composite material.

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  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Organic Chemistry (AREA)
  • Compositions Of Macromolecular Compounds (AREA)
  • Paper (AREA)
  • Reinforced Plastic Materials (AREA)

Abstract

Des matériaux composites légers, de haute résistance, comprenant des éléments discrets de renforcement entourés par une matrice comprenant des micro-morceaux polymères qui sont sensiblement exempts des cellules intactes des polymères thermoplastiques hydrophobes, expansés, à partir desquels ils sont produits, sont préparés par pressage à chaud d'éléments similaires au papier en utilisant une technologie de fabrication du papier.
PCT/US1987/003440 1985-11-08 1987-12-24 Materiaux composites, leur preparation et articles fabriques a partir de ces materiaux WO1989005833A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
PCT/US1987/003440 WO1989005833A1 (fr) 1985-11-08 1987-12-24 Materiaux composites, leur preparation et articles fabriques a partir de ces materiaux
JP50209688A JPH03503058A (ja) 1987-12-24 1987-12-24 複合材料，それらの製造方法及びそれらから製造した成形品

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US06/796,929 US4716062A (en) 1985-11-08 1985-11-08 Composite materials, their preparation and articles made therefrom
PCT/US1987/003440 WO1989005833A1 (fr) 1985-11-08 1987-12-24 Materiaux composites, leur preparation et articles fabriques a partir de ces materiaux

Publications (1)

Publication Number Publication Date
WO1989005833A1 true WO1989005833A1 (fr) 1989-06-29

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PCT/US1987/003440 WO1989005833A1 (fr) 1985-11-08 1987-12-24 Materiaux composites, leur preparation et articles fabriques a partir de ces materiaux

Country Status (1)

Country Link
WO (1) WO1989005833A1 (fr)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9718980B2 (en) 2012-08-14 2017-08-01 Goldeast Paper (Jiangsu) Co., Ltd Coating composition and coated paper

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4426470A (en) * 1981-07-27 1984-01-17 The Dow Chemical Company Aqueous method of making reinforced composite material from latex, solid polymer and reinforcing material
US4543288A (en) * 1984-01-06 1985-09-24 The Wiggins Teape Group Limited Fibre reinforced plastics sheets
US4670331A (en) * 1984-01-06 1987-06-02 The Wiggins Teape Group Limited Moulded fibre reinforced plastics articles

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4426470A (en) * 1981-07-27 1984-01-17 The Dow Chemical Company Aqueous method of making reinforced composite material from latex, solid polymer and reinforcing material
US4543288A (en) * 1984-01-06 1985-09-24 The Wiggins Teape Group Limited Fibre reinforced plastics sheets
US4670331A (en) * 1984-01-06 1987-06-02 The Wiggins Teape Group Limited Moulded fibre reinforced plastics articles
US4543288B1 (fr) * 1984-01-06 1988-01-26

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US9718980B2 (en) 2012-08-14 2017-08-01 Goldeast Paper (Jiangsu) Co., Ltd Coating composition and coated paper

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