Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
  • D04H1/64—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives the bonding agent being applied in wet state, e.g. chemical agents in dispersions or solutions
• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
  • D04H1/587—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives characterised by the bonding agents used

Definitions

• This invention relates to a binder composition for fiber mats, in particular to a starch based binder composition.
• Various products are prepared by forming a mat of fibers which then have a binder applied to coat or impregnate the fiber mat.
• Typical fibers include polyester fibers, glass fibers, polypropylene fibers, cellulose fibers or other nonwoven fiber materials.
• Polyester fibers are often dry laid to form a mat which is then fed through a pad bath to apply a binder. After drying and curing, the polyester mat is fed through a hot asphalt bath to apply a coating of asphalt. Due to the high temperature of the asphalt bath, untreated polyester mat will stretch resulting in a decrease in the width of the mat. Application of a binder will lessen that stretch and lessen the shrinkage of the mat width.
• Conventional binder systems comprise acrylic or vinyl acrylic latex emulsions. However, these conventional latex systems have exhibited an unacceptable level of stretching and wicking and generally contain formaldehyde-based crosslinking agents.
• Fiberglass roofing mats have been conventionally treated with a urea-formaldehyde resin binder which can typically contain about 10 to 20% acrylic latex. However, it is desirable to improve the dry, wet and hot wet tensile strength of these systems and/or partially or fully replace the urea-formaldehyde resin in the binder.
• An object of this invention is to provide a starch based binder composition which when applied to a fiber mat, dried and cured reduces the level of stretching and wicking.
• Another object of this invention is to provide a starch based binder composition with desirable dry, wet and hot wet tensile strength when applied to a fiber mat.
• a still further object of this invention is to provide a binder composition which can eliminate or reduce the use of formaldehyde-based crosslinking agents and urea-formaldehyde resins.
• a starch binder composition for fiber mats which comprises a starch, a starch crosslinking agent, an anti-wicking agent and preferably a polymer strength additive.
• the starch binder composition when applied to a fiber mat, dried and cured reduces the stretching and wicking of the mat, particularly when the mat is to be subsequently coated and provides improved dry, wet and hot wet tensile strength.
• the bound fiber mats can be subsequently coated, for example, with an asphalt or resin depending upon the end use.
• the binder composition of this invention is a starch based system.
• the starch can be any one of a variety of starches with the starch preferably being chosen to provide a high solids binder composition while maintaining a workable viscosity.
• the starch may be from corn, wheat, potato, waxy maze or sorghum and may be treated by any one of a variety of known methods, e.g. the starch may be gelatinized, enzyme converted, acid modified and oxidized; or starch esters, starch ethers, starch acetates, as well as starch derivatives such as cyclodextrins or maltodextrins can be used.
• starch may be used in a granular ungelatinized form, preferably it is first gelatinized.
• Preferred starches include maltodextrins, acid modified, enzyme converted, oxidized and ethoxylated starches.
• the starches are chosen to be able to formulate a high solids aqueous binder composition, i.e. greater than 25% solids, and preferably the starch will provide a viscosity of less than 500cps when measured at room temperature and at a solids level of 35% on a Brookfield viscometer having a #3 spindle at 100rpm.
• the starch chosen is a low molecular weight starch, i.e.
• a starch crosslinking agent is added to the binder composition for the purpose of crosslinking the starch.
• Various crosslinking agents which are commonly used to crosslink starch may be used including, but not limited to, urea formaldehyde resins, melamine formaldehyde resins, acetone formaldehyde resins, glyoxal, blocked glyoxal resins (e.g. glyoxal blocked with polyols, glycols or cyclic urea) or various metal salts including ammonium zirconium carbonate.
• a preferred crosslinking agent is the blocked glyoxal resin, as is disclosed in U.S. Patent No. 4695606, particularly the cyclic urea glyoxal condensation product disclosed therein.
• the crosslinking agent is added at a level of 1 to 15% based on the dry weight of the starch, preferably about 5 to 10%.
• a polymer strength additive is added to the starch binder composition.
• the polymer strength additive is added at a level less than 50% by dry weight of the starch, preferably up to 10% by dry weight of the starch.
• Suitable polymers include polyvinyl alcohol and homopolymers or copolymers of acrylamide.
• the polymer can be a copolymer of acrylamide and either acrylic acid, methacrylic acid, vinyl acetate, vinyl pyrrolidone, sodium vinyl sulfonate, hydroxethyl acrylate, acrylonitrile, acrylic ester, methacrylic ester, cationic monomers, N-substituted acrylamide and N-substituted methacrylamide.
• a preferred polymer strength additive is either polyvinyl alcohol or a copolymer of acrylamide and methacrylic acid or both used together. Where wet tensile strength is important, such as in glass mat applications, a polyamine-polyamide epichlorohydrin reaction product may also be added.
• An anti-wicking agent is added to prevent wicking in the fiber mat bound by the starch binder composition. Wicking is the capillary action which draws liquid through the fibrous mat and is generally considered undesirable in fiber mat applications.
• the anti-wicking agent is commonly referred to as a sizing agent or a water repellant and may be any agent which inhibits the capillary action of fluids in the bound fiber mat.
• the anti-wicking agent is often formulated as an emulsion consisting of a hydrophobic base, such as a wax, a melamine formaldehyde resin alkylated by fatty alcohols, alkyl ketene dimers, alkenyl succinic anhydrides, fluorochemicals, or silicone oils; and an emulsifying agent such as ethoxylated alkyl phenols, ethoxylated caster oils, ethoxylated fatty alcohols, ethoxylated fatty acids, sulfate esters, phosphate esters, quaternary ammonium salts, ethoxylated or propoxylated fatty alcohols or amine oxides.
• a hydrophobic base such as a wax, a melamine formaldehyde resin alkylated by fatty alcohols, alkyl ketene dimers, alkenyl succinic anhydrides, fluorochemicals, or silicone oils
• a preferred anti-wicking agent comprises a melamine-­formaldehyde resin alkylated by fatty alcohols and a non-rewetting surfactant such as the amine oxide of dimethyl amino propyl lauramide.
• Another preferred anti-wicking agent is a neutralized solution of a styrene-maleic anhydride copolymer.
• the anti-wicking agent is added at a level of up to 4% by dry weight of the starch, preferably at a level of up to 1%.
• a latex such as a vinyl emulsion polymer or an acrylic emulsion polymer may be added to the bath formulation generally at levels up to 30% by dry weight of the starch.
• a surfactant may also be added to the starch binder composition to improve the stability of the emulsion mixture with preferred surfactants including an amide oxide of dimethyl amino propyl lauramide, amine oxide of dimethyl amino ethyl lauramide, ethoxylated fatty alcohol, ethoxylated fatty acid ester, propoxylated-ethoxylated fatty alcohols and ethoxylated alkyl phenol.
• preferred surfactants including an amide oxide of dimethyl amino propyl lauramide, amine oxide of dimethyl amino ethyl lauramide, ethoxylated fatty alcohol, ethoxylated fatty acid ester, propoxylated-ethoxylated fatty alcohols and ethoxylated alkyl phenol.
• a surfactant will be added at a level of 0.001% to 5% by dry weight of the starch.
• biocide such as Kathon LX R by Rohm & Haas which is a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one to improve the storage shelf stability of the starch binder composition, generally at levels of up to 25ppm active ingredients of the finished starch-based product or a level recommended by the supplier to insure biocidal activity.
• biocide such as Kathon LX R by Rohm & Haas which is a mixture of 5-chloro-2-methyl-4-isothiazolin-3-one and 2-methyl-4-isothiazolin-3-one to improve the storage shelf stability of the starch binder composition, generally at levels of up to 25ppm active ingredients of the finished starch-based product or a level recommended by the supplier to insure biocidal activity.
• the various ingredients may be blended together in water.
• the starch crosslinking agent is maintained separate from the remainder of the binder composition until use is anticipated in order to extend the shelf stability.
• the starch binder composition of this invention can be formulated at solid levels of anywhere from 3 to 50%, advantageously, a high solids starch binder composition can be formulated containing at least 25% solids. This high solids level can be achieved while maintaining a viscosity of below 500cps as measured on a Brookfield viscometer at room temperature having a #3 spindle at 100rpm.
• the starch binder composition may be coated and/or impregnated into the fiber mat, dried and cured by any known or conventional means available.
• the starch binder composition will be coated or impregnated onto or into the fiber mat at a level of about 10 to 30% by dry weight of the fiber mat and the coated and/or impregnated mat will be dried and cured generally at temperatures ranging from 80°C to 250°C for 0.25 to 8 minutes.
• Mat samples (9" x 12") of polyester fibers were impregnated in a pad bath containing either a latex binder (acrylic/N-methylol acrylamide copolymer emulsion) or starch based binders at 15% solids.
• Mat samples were padded to 145% wet pick-up to achieve an add-on level of 22% dry weight. Samples were dried and cured at 204°C (400°F) for 3.5 minutes. Samples were equilibrated at 180°C in the environmental chamber of an Instron Model 1130 instrument and tested for percent stretch at 5Kg and 8Kg.
• a comparison of Samples #1 and #2 shows the benefit of a starch binder compared to a conventional system using a latex binder.
• the percent stretch for the starch binder is substantially less than the latex binder, although the wicking is worsened.
• Comparison of Sample #3 to Samples #1 and #2 shows the benefit of adding a starch crosslinking agent to the formulation. The stretching is substantially reduced in Sample #3, although there is substantial wicking.
• a comparison of Sample #4 to the previous samples shows the further improvement which was obtained by the addition of a small amount of acrylamide-methacrylic acid copolymer; however, wicking is still high.
• Comparing Sample #5 to the other samples show the benefit of adding a small amount of anti-wicking agent to the formulation.
• the percent stretch is about one-half the level found in a conventional latex system and there is a substantial reduction of wicking compared to the latex or other starch systems.
• the samples in Table II demonstrate the usefulness of various starch crosslinking agents.
• the crosslinking agents used in this example include cyclic urea-glyoxal condensate, glycol-glyoxal condensate and melamine-formaldehyde resin.
• the binder was applied to a polyester mat and tested as detailed in Example I. In all three cases, the stretch is less than that seen with the conventional latex (acrylic/N-methylol acrylamide copolymer emulsion).
• the anti-wicking agent was deleted in these samples to better observe the performance of the crosslinking agents.
• a pad bath was prepared with the starch binder composition of Sample 5 of Example I at 25% solids and heated to 110°F (43°C). The room temperature viscosity of this bath was 125cps and at 100°F the viscosity was 90cps (Brookfield RV Viscometer, #3 spindle at 100rpm). A polyester mat was padded through 1 dip and 1 nip, then dried and cured for 3.5 minutes at 400°F (204°C). The sample was tested in the same manner as in previous examples with the following results: Tensile Kg : 26.05 180°C % Stretch: 5 Kg 1.60 8 Kg 5.20 Wicking mm : 12
• a starch was modified with a starch crosslinking agent by adding to a 1 liter round bottomed flask fitted with a mechanical stirrer, thermometer and condenser 445.2g of water, 6 grams of an 18% acrylamide-methacrylic acid copolymer, 6g of a 45% cyclic urea-glyoxal condensate, 0.5g of an ammonia-­hydrolyzed styrene-maleic anhydride copolymer sizing agent and 240g of a low molecular weight acid modified starch (maltodextrin, m.w. 3600 daltons). This mixture was heated to 90°C for 30 minutes, then cooled to 35°C.
• the tan suspension was slightly foamy, which was remedied by adding four drops of a commercial defoamer, and ten drops of biocide to inhibit mold formation.
• Example VI was similar to Example V in that a starch was modified with a starch crosslinking agent except that 4% of the low molecular weight starch was replaced by a high molecular weight starch (oxidized and ethoxylated potato starch), and 44g of a blocked glyoxal resin was used. After cooking for 30 minutes at 90°C, the product was cooled to 40°C. To the product was then added 2.8g of an emulsified sizing agent consisting of a stearylated melamine resin and surfactants; and a biocide.
• This starch binder was suitable for use with a urea formaldehyde resin, an acrylamide copolymer and a wet strength agent for binding a glass mat.
• Sample 12 containing a mixture consisting of 25% of an 18% solution copolymer of acrylamide and methacrylic acid (72:28 mole ratio), 50% of the starch binder in Example VI and 25% of a 12.5% solution of a polyamide-polyamine-epichlorohydrin wet strength agent was prepared for use with a urea formaldehyde resin.
• Sample 13 contained a mixture similar to Sample 12 except that an 18% solution of a 10 mole% cationic polyacrylamide copolymer was used in lieu of the acrylamide-methacrylic acid copolymer.
• the products of Samples 12 and 13 were mixed to comprise 20% of the solids of a bath with a commercial urea formaldehyde resin which comprised 80% of the bath solids.
• Sample 13 of Example VII was mixed so as to comprise 20% of the solids of a pad bath, with a urea-­formaldehyde resin comprising 80% of the solids.
• a similar bath was prepared in which an acrylic/N-methylol acrylamide latex comprised 20% of the solids.
• These binders were applied to fiberglass mat on a pilot-scale production machine, followed by normal drying and curing conditions. The results are in Table VI.

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• Engineering & Computer Science (AREA)
• Textile Engineering (AREA)
• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Dispersion Chemistry (AREA)
• General Chemical & Material Sciences (AREA)
• Treatments For Attaching Organic Compounds To Fibrous Goods (AREA)
• Nonwoven Fabrics (AREA)
• Adhesives Or Adhesive Processes (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Fireproofing Substances (AREA)

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Cited By (36)

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• 1989
  • 1989-07-31 JP JP1199166A patent/JPH0299655A/ja active Pending
  • 1989-08-02 EP EP89307872A patent/EP0354023A3/de not_active Withdrawn

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