Classifications

• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J131/00—Adhesives based on homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and at least one being terminated by an acyloxy radical of a saturated carboxylic acid, of carbonic acid, or of a haloformic acid; Adhesives based on derivatives of such polymers
  • C09J131/02—Homopolymers or copolymers of esters of monocarboxylic acids
  • C09J131/04—Homopolymers or copolymers of vinyl acetate
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09J—ADHESIVES; NON-MECHANICAL ASPECTS OF ADHESIVE PROCESSES IN GENERAL; ADHESIVE PROCESSES NOT PROVIDED FOR ELSEWHERE; USE OF MATERIALS AS ADHESIVES
  • C09J123/00—Adhesives based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Adhesives based on derivatives of such polymers
  • C09J123/02—Adhesives based on homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Adhesives based on derivatives of such polymers not modified by chemical after-treatment
  • C09J123/04—Homopolymers or copolymers of ethene
  • C09J123/08—Copolymers of ethene
  • C09J123/0846—Copolymers of ethene with unsaturated hydrocarbons containing other atoms than carbon or hydrogen atoms
  • C09J123/0853—Vinylacetate
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L1/00—Compositions of cellulose, modified cellulose or cellulose derivatives
  • C08L1/08—Cellulose derivatives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
  • C08L23/08—Copolymers of ethene
  • C08L23/0846—Copolymers of ethene with unsaturated hydrocarbons containing atoms other than carbon or hydrogen
  • C08L23/0869—Copolymers of ethene with unsaturated hydrocarbons containing atoms other than carbon or hydrogen with unsaturated acids, e.g. [meth]acrylic acid; with unsaturated esters, e.g. [meth]acrylic acid esters
  • C08L23/0876—Salts thereof, i.e. ionomers
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L2666/00—Composition of polymers characterized by a further compound in the blend, being organic macromolecular compounds, natural resins, waxes or and bituminous materials, non-macromolecular organic substances, inorganic substances or characterized by their function in the composition
  • C08L2666/02—Organic macromolecular compounds, natural resins, waxes or and bituminous materials
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L33/00—Compositions of homopolymers or copolymers of compounds having one or more unsaturated aliphatic radicals, each having only one carbon-to-carbon double bond, and only one being terminated by only one carboxyl radical, or of salts, anhydrides, esters, amides, imides or nitriles thereof; Compositions of derivatives of such polymers
• • 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/20—Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
  • Y10T442/2631—Coating or impregnation provides heat or fire protection
  • Y10T442/2721—Nitrogen containing
• • 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
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T442/00—Fabric [woven, knitted, or nonwoven textile or cloth, etc.]
  • Y10T442/20—Coated or impregnated woven, knit, or nonwoven fabric which is not [a] associated with another preformed layer or fiber layer or, [b] with respect to woven and knit, characterized, respectively, by a particular or differential weave or knit, wherein the coating or impregnation is neither a foamed material nor a free metal or alloy layer
  • Y10T442/2926—Coated or impregnated inorganic fiber fabric
  • Y10T442/2934—Coating or impregnation contains vinyl polymer or copolymer
  • Y10T442/2943—Vinyl acetate polymer or copolymer

Definitions

• This invention relates to improved adhesives. Specifically, the invention relates to improved adhesives that exhibit improved dispensability properties.
• Typical consumer adhesives or white glues are formulated at 40 to 60 percent solids and have a viscosity ranging from 2,000 to 300,000 cP as measured by on a Brookfield viscometer.
• These adhesives or white glues have a variety of shortcomings such as, for example, regardless of viscosity, the glues run or sag when applied to a vertical surface. In addition, these glues suffer from imprecise dispensability. Low viscosity glues are excessively runny and high viscosity glues are excessively stringy. In general, the more viscous glues tend to be slow to "set" and are difficult to obtain in thin sections since they do not spread easily under modest stress. Thick glue sections can be undesirable since upon drying, they exacerbate curl and cockle effects in paper substrates. Thus, there is a need for an improved adhesive.
• an adhesive composition includes a polymer adhesive material and a thickener.
• the adhesive composition has a stringing length of 9 cm or less and a phase lag, ⁇ , (hereinafter referred to as "phase lag") of 45 degrees or less, or a sag distance of 5 mm or less.
• phase lag phase lag
• the adhesive can be formed by combining a vinyl acetate polymer, an alkali swellable thickener, an alkali material, and water.
• an article includes a dispenser container having a dispensing opening and an adhesive composition disposed within the dispenser container.
• the adhesive composition includes a polymer adhesive material and a thickener.
• the adhesive composition has a stringing length of 9 cm or less and a phase lag of 45 degrees or less.
• an adhesive composition includes a vinyl acetate polymer, an alkali swellable thickener, and water. The vinyl acetate polymer is dispersed within the water and the adhesive composition has a pH of 4 to 10.
• FIG. 1 is a schematic view of an illustrative adhesive dispenser. While the invention is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the invention to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.
• the present invention is believed to be applicable generally to adhesives and their manufacture, as well as apparatus for dispensing such improved adhesives. While the present invention is not so limited, an appreciation of various aspects of the invention will be gained through a discussion of the examples provided below.
• polymer will be understood to include polymers, copolymers (e.g., polymers formed using two or more different monomers), oligomers and combinations thereof, as well as polymers, oligomers, or copolymers that can be formed in a miscible blend by, for example, coextrusion or reaction, including transesterification. Both block and random copolymers are included, unless indicated otherwise.
• Weight percent, percent by weight, % by weight, and the like are synonyms that refer to the concentration of a substance as the weight of that substance divided by the weight of the composition and multiplied by 100.
• the present invention provides an improved adhesive.
• the improved adhesive includes a polymer adhesive material, and a thickener.
• the improved adhesive has two or more of the following physical properties: a limited stringing length; a limited phase lag; a limited sag distance; a viscosity such that the adhesive is flowable; a limited set time; a range of complex shear modulus; and the adhesive composition may not be thixotropic. Many of these properties can be determined by the methods set in the Methods section below.
• the adhesive composition can have a limited stringing length. Stringing length of an adhesive can be determined by the stringing length method defined in the Methods section below. A limited stringing length can aid in precise placement of flowable adhesives.
• the adhesive composition can have a stringing length of 0 to 9 cm, or 0 to 5 cm, 0 to 3 cm, or 0 to 2 cm.
• the adhesive composition can have a limited shear modulus phase lag.
• Shear modulus phase lag or "phase lag,” can be determined by the phase lag method defined in the Methods section below.
• the adhesive composition can have a phase lag of 0 to 45 degrees, or 0 to 30 degrees, or 0 to 20 degrees.
• the adhesive composition can have a limited sag distance when placed on a vertical surface. Sag distance or sag resistance can be determined by the sag distance method defined in the Methods section below. A limited sag distance can aid in keeping adhesive on a surface where it is placed. In some embodiments, the adhesive composition can have a sag distance of 0 to 10 mm, or 0 to 5 mm, or 0 to 2 mm.
• the adhesive composition can have a viscosity such that the adhesive is flowable. Viscosity can be determined via a Brookfield RVT with a #6 spindle at 20 rpm at ambient conditions. In some embodiments, the adhesive composition can have a viscosity of 3,000 to 50,000 cP, or 3,000 to 30,000 cP, or 10,000 to 30,000 cP.
• the adhesive composition can have a limited set time.
• Set time of the adhesive can be determined by the set time method defined in the Methods section below.
• the adhesive composition can have a set time of 0 to 180 seconds, or 0 to 60 seconds, or 0 to 45 seconds.
• the adhesive composition can have a range of complex shear modulus G*.
• Complex shear modulus G* can be determined by the complex shear modulus method defined in the Methods section below.
• the adhesive composition can have a complex shear modulus G* of 50 to 1000 Pa, or 100 to 600 Pa.
• the adhesive composition includes a polymer adhesive material and a thickener where the adhesive composition has a stringing length of 9 cm or less and a phase lag of 45 degrees or less.
• the adhesive composition includes a polymer adhesive material and a thickener where the adhesive composition has a stringing length of 9 cm or less and a sag distance of 10 mm or less.
• two or more of the above identified physical properties can be combined, as desired.
• the improved adhesive composition can be formed by combining an adhesive polymer, a thickener, and water.
• the adhesive polymer can be a vinyl acetate polymer.
• the thickener can be an alkali swellable thickener, hi some embodiments, the adhesive composition can have a glass transition temperature in a range of -60 to 100 degrees Celsius, or, -50 to 50 degrees Celsius, -20 to 30 degrees Celsius. As used herein, glass transition temperatures of the adhesive composition are taken from dried adhesive compositions, hi illustrative embodiments, the adhesive composition can have a total solids content from 5 to 85 wt%, or 30 to 85wt%, or 60 to 80 wt%, as desired.
• the adhesive composition can have a pH of 4 to 10, or 5 to 10, or 6 to 9. In other embodiments the adhesive composition can be considered as being "acid-free" and have a pH of 7 to 9. In some embodiments, an alkali or alkaline material can be added to the adhesive composition in any useful amount.
• Vinyl acetate polymers include, for example, vinyl acetate homopolymers and vinyl acetate co-polymers such as, for example, vinyl acetate-ethylene (VAE). These vinyl acetate polymers can be combined in water to form a polymer dispersion. Vinyl acetate based polymers can be obtained by conventional emulsion polymerization and are commercially available from a variety of sources.
• the vinyl acetate polymer includes vinyl acetate, ethylene, and optionally one or more other ethylenically unsaturated monomers.
• ethylenically unsaturated monomers are C 3 -C 10 alkenoic acids, such as acrylic acid, methacrylic acid, crotonic acid and isocrotonic acid and their esters with C 1 -C 18 alkanols, such as methanol, ethanol, propanol, butanol, and 2-ethylhexanol; vinyl halides, such as vinyl chloride; alpha, beta-unsaturated C 4 -C 10 alkenedioic acids such as maleic acid, fumaric acid, and itaconic acid and their monoesters and diesters with the same C 1 -C 18 alkanols; and nitrogen containing monoolefinically unsaturated monomers
• Illustrative vinyl acetate-ethylene (emulsion) polymers used in this invention are commercially available products. Examples are AIRFLEXTM 320, AIRFLEXTM 323, AIRFLEXTM 400, AIRFLEXTM 400H, AIRFLEXTM 401 , AIRFLEXTM 405, AIRFLEXTM 410, AIRFLEXTM 420, AIRFLEXTM 423, AIRFLEXTM 426, AIRFLEXTM 460, AIRFLEXTM 465, AIRFLEXTM 7200, AIRFLEXTM 920, AIRFLEXTM EN421, AIRFLEXTM EP 17, AIRFLEXTM 315, AIRFLEXTM 418, AIRFLEXTM EF, 350, and AIRFLEXTM EF940, all available from Air Products Polymers, L.P., (Allentown, PA) and ELVACETM 722, ELVACE TM 725, ELVACE TM 731
• Vinyl acetate polymers typically can have a viscosity ranging from 500 to 3000 cP.
• Vinyl acetate polymers can be present in the adhesive compositions in any useful amount. In some embodiments, vinyl acetate polymers are present in the adhesive composition from 5 to 75 wt%, or from 20 to 75wt%, or 50 to 75 wt%, as desired.
• Alkali swellable thickeners include alkali swellable acrylic thickeners. These acrylic thickeners can be termed an "associative thickener" and can be anionic alkali swellable acrylic aqueous emulsion copolymers containing carboxylic acid groups. These alkali swellable thickeners can be substantially cross-linked.
• a partial listing of suitable alkali swellable acrylic thickeners includes those commercially available under the trade name RhoplexTM ASE-60, from Rohm and Haas Co. (Philadelphia, PA) and RohagitTM SD 15 available from Polymer Latex GmbH & Co.
• Alkali swellable thickeners can be present in the adhesive compositions in any useful amount. In some embodiments, Alkali swellable thickeners are present in the adhesive composition from 0.1 to 10 wt%, or from 0.1 to 5 wt%, or 0.1 to 3 wt%, as desired.
• the alkalinity source can be a strong base material or a source of alkalinity which can be an organic source or an inorganic source of alkalinity.
• a source of alkalinity also known as an alkali material is a composition that can be added to an aqueous system and result in a pH greater than about 7.
• Organic sources of alkalinity are often strong nitrogen bases including, for example, ammonia, monoethanol amine, monopropanol amine, diethanol amine, dipropanol amine, triethanol amine, tripropanol amine, etc.
• the source of alkalinity can also comprise an inorganic alkali.
• the inorganic alkali can be derived from sodium or potassium hydroxide which can be used in both liquid (about 10- 60 wt % aqueous solution) or in solid (powder, flake or pellet) form.
• Other inorganic alkalinity sources are soluble silicate compositions such as sodium metasilicate or soluble phosphate compositions such as trisodium phosphate, or any other buffer derived from phosphoric acid.
• Exemplary alkalinity sources include ammonia, or triethanol amine.
• the alkalinity source can include an alkali metal carbonate. Alkali metal carbonates which may be used include sodium carbonate, potassium carbonate, sodium or potassium bicarbonate or sesquicarbonate, among others.
• the alkali material can be provided in the adhesive composition in any useful amount.
• the adhesive compositions of the invention can optionally include fillers.
• Fillers can be organic or inorganic fillers and can be present in the adhesive in any useful amount. Fillers can be any organic or inorganic additives such as, for example, antioxidants, stabilizers, antiozonants, plasticizers, dyes, U. V. absorbers, HALS, and pigments.
• the adhesive composition includes a "glitter" material as a filler. The glitter material can add sparkle and/or color to the adhesive as desired.
• the adhesive compositions of the invention can optionally include colorants, such as pigments or dyes, to provide a tint or color to the adhesive composition.
• the adhesive composition can include 5 to 75 wt% vinyl acetate polymer, 0.1 to 10 wt% alkali swellable thickener, and a balance water. In other embodiments, the adhesive composition can include 20 to 75 wt% vinyl acetate polymer, 0.1 to 5 wt% alkali swellable thickener, and a balance water.
• the adhesive composition can include 50 to 75 wt% vinyl acetate polymer, 0.1 to 3 wt% alkali swellable thickener, and a balance water, hi some of these embodiments, the formation of the adhesive composition can include the addition of an alkali material that may activate or swell the alkali swellable thickener material and provide a resulting adhesive composition that can have a pH of 7 to 9. hi illustrative embodiments, the alkali swellable thickener material is substantially cross-linked.
• a limited stringing length a limited phase lag; a limited sag distance; a viscosity such that the adhesive is flowable; a limited set time; a range of complex shear modulus; and the adhesive composition may not be thixotropic.
• FIG. 1 shows an illustrative adhesive dispenser 100 that can hold and dispense the improved adhesive described herein.
• the dispenser 100 can include an adhesive containing portion 120 that contains the adhesive prior to being dispensed.
• the containing portion 120 is formed of a flexible material such as a polymeric material.
• the dispenser can contain any useful amount of adhesive such as, for example, 0.5 to 5000 ml, or 0.5 to 1000 ml, or 50 to 500 ml.
• the dispenser 100 can include a dispensing portion 130 disposed on the containing portion 120.
• the dispensing portion 130 can include a dispenser opening 140.
• adhesive can be dispensed by a user by the user applying finger pressure to the flexible containing portion 120 which urges adhesive material toward and through the dispenser opening 140 to the application target.
• the dispenser opening 140 has an area in a range of 0.05 to 40 mm 2 , 0.1 to 30 mm 2 , 0.1 to 10 mm 2 , 0.2 to 1.8 mm 2 , 0.5 to 1.5 mm 2 , or 0.75 to 1.25 mm 2 , as desired.
• Described herein are adhesive compositions exhibiting a unique combination of rheology and fast set time, and when applied to paper substrates, can reduce the amount of curl/cockle observed. These adhesive compositions are easily and precisely dispensed from a fine tipped applicator using only hand pressure to apply. Such adhesive/dispenser combinations are often used in performing craft projects, household repairs, or scrapbooking activities.
• the combination of adhesive rheology and fine tipped dispensers provides excellent control during adhesive dispensing and allows the user to effortlessly apply the adhesive in any shape desired (fine or coarse dots, streaks, lines, etc).
• the adhesive rheology can also assist in the creation of thin bond lines due to the ease with which the adhesive spreads when compressed lightly between adherents with modest lamination pressure, e.g., light hand pressure used to laminate paper card stock together.
• Such thin adhesive bond lines can also contribute to fast adhesive drying since the thin cross- sectional area of the adhesive increases the rate at which moisture is removed from the adhesive, hi addition the rheology provided by associative thickened adhesive polymers described herein also minimizes/eliminates the tendency of the adhesive to string or leg when applied in small drops or in a fine continuous bead, thus allowing more precise application of the adhesive.
• This test involves the following steps:
• Adhesive sag resistance is assessed by depositing a 0.1 ml drop of adhesive near an end of a horizontally positioned 2 mil clean thick strip of poly(ethylene terephthalate) (PET) film measuring ⁇ 15 cm x 25 cm. Immediately following adhesive deposition, the PET film is positioned vertically, with the adhesive drop located at the top of sheet, which allows the adhesive to flow downward along the length of the film strip.
• PET poly(ethylene terephthalate)
• the distance, in millimeters (mm), the adhesive has flowed is measured and recorded.
• the specific distance measured is that distance from the bottom edge of the original adhesive drop, prior to orienting vertically, to the bottom most edge of the adhesive flow once the adhesive flow has ceased.
• This test method provides a means of assessing the extent to which an adhesive strings when dispensed.
• the test method involves dispensing glue through a vertically oriented syringe needle at fixed rate, and measuring the length of the glue fiber/strand that forms as the glue extends from the needle and falls to a stage below. The longer the strand the higher the extent of stringing, the shorter the strand the lower the extent of stringing.
• This test method is conducted in a constant temperature room having temperature of 22 0 C and a relative humidity of 50% and employs the following equipment. 1. Syringe pump, catalog # 55-2226, Harvard Apparatus, So Natick, MA 01760
• Cylindrical sleeve constructed from 0.45 mm thick clear polycarbonate ⁇ 14 cm dia x 38 cm tall and slotted appropriately to allow clearance for clamp and Teflon tubing clearance.
• the syringe/tubing/needle assembly is arranged with the syringe mounted horizontally in the syringe pump and needle oriented vertically, such that the extruded adhesive discharges straight downward from the needle tip.
• the small clamp is affixed to the vertical member of the jack stand and the needle is secured with the clamp to maintain orientation during the test.
• the lab jack is placed on the jack stand below the needle to provide a movable stage onto which the flowing adhesive impinges.
• the range of lab jack motion is ⁇ 38 cm total, i.e., the jack can be elevated to touch the tip of the needle and can be lowered 38 cm below the tip of the needle.
• the polycarbonate sleeve is used as a draft eliminator to reduce the effect of any air motion on the falling strand of adhesive.
• the sleeve is placed on the jack such that it is concentric with the circumference of the needle barrel.
• Two longitudinal slots are required on the sleeve to allow the sleeve to pass by the small clamp and the flexible tubing as the lab jack is raised or lowered.
• the needle was shortened, using a die grinder fit with cut-off wheel, to provide a square end on the barrel of the needle and a length of 6.4 mm, i.e., 6.4 mm of needle protruded from the hub.
• the shortened needle barrel was deburred with 320 grit sandpaper.
• the square-ended needle barrel allows uniform discharge of the adhesive from the needle and minimizes any tendency for the extruded adhesive to drag or distort upon exiting the needle.
• the adhesive is free of bubbles prior to performing this test.
• the syringe is filled with adhesive by immersing the syringe tip into the adhesive and gently withdrawing the plunger to fill the syringe. Care must be taken during this operation to avoid introducing air into the adhesive as this deleteriously affects the test outcome, i.e., air bubbles in the discharged adhesive can cause flaws in the stream that result in premature breakage of the falling stream.
• the filled syringe is fit with the flexible connection tube and needle, and mounted in the syringe pump.
• the pump is started to provide an adhesive flow of 1.75 milliliters/minute (ml/min).
• the syringe needle is initially held by hand and oriented to discharge straight upward in order to purge any air from the flexible line, connections, or needle.
• the pump is stopped, the needle orientation reversed (to discharge straight down), the needle clamped in position for testing, and the jack and cylindrical sleeve placed as described above.
• the stage is positioned at a distance of 2.5 cm from the needle tip, the pump started, and the adhesive stream observed. If the adhesive stream is stable and continuous the stage is slowly lowered in 1 cm increments, with a 5 second observation time required at each height, until the stream breaks. The stage is then raised until the flow reconnects to provide a continuous stream. The stage is lowered in steps to the point at which the stream breaks-off, and the distance at which a continuous flow occurred is recorded (i.e., that distance from the needle tip to the stage).
• This protocol is repeated 2 more times to obtain a total of 3 separate measurements of the maximum distance at which a continuous strand could be observed. If upon starting the test the stream is discontinuous, the stage is raised to a point at which the flow connects to provide a continuous stream and the protocol described above followed to complete the test. For certain adhesives, during the course of the test, the dispensed adhesive collecting on the stage may tend to pile up, thus when recording the maximum distance at which a continuous flow occurred, any buildup on the stage must be taken into account, i.e., the build-up distance (the height from the stage to the top of the adhesive pile) subtracted from the overall measured distance. The average of the three measurements is recorded as the "Continuous Fiber Stringing Length" and reported in centimeter units.
• Shear Modulus Phase Lag " ⁇ " and Complex Shear Modulus "G*" Dynamic mechanical properties of the samples were measured with a Bohlin CVO 120 HR NF rheometer. Bohlin rheometers are available from Malvern Instruments Ltd., Enigma Business Park, Grovewood Road, Malvern, Worcestershire, United Kingdom, WR14 IXZ. All measurements were taken using the Bohlin C25 Mooney-Couette geometry at 25 degrees Celsius. A trap was placed over the top of the C25 cup to retard sample drying.
• Evaporation traps are available from Malvern Instruments.
• the dynamic mechanical properties of interest are the complex shear modulus, G , and the phase lag, which is also sometimes called phase shift. These two parameters are often used to describe the relationship between stress and strain for materials, and in particular for viscoelastic materials. Materials with high moduli provide greater resistance to an applied stress, resulting in smaller strains, than those with low moduli.
• the phase lag is, by definition, bounded between zero and 90 degrees and represents the relative levels of elastic and viscous response of the sample to the applied stress. Purely elastic (i.e., Hookean) materials have a zero degree phase lag and purely viscous materials have a 90 degree phase lag relative to the oscillatory stress.
• G * and ⁇ were measured by loading 17 grams of each sample into the rheometer. The samples were equilibrated to 25° C, sheared for 30 seconds at 50 s '1 , and then allowed to rest for 30 seconds before each test was run. Sinusoidally oscillating stresses were applied to each sample at a frequency of 1 Hz. Ten stress amplitudes, increasing logarithmically from 0.1 Pa to 100 Pa, were chosen as test conditions. The values of G and ⁇ at 1.7 Pa recorded by the instrument are used here.
• RhoplexTM ASE-60 alkali swellable associative thickener supplied at 28% solids, Rohm and Haas Co., Philadelphia, PA.
• Ammonium hydroxide 28-30% NH3, EM Science, Gibbstown, NJ.
• KelzanTM S xanthan gum, lot 40863A, CP Kelco U.S., Inc., San Diego, CA.
• Sodium carboxymethylcellulose Na CMC
• type 7H4XF lot 83724, Aqualon Division of Hercules Inc., Wilmington, DE.
• KelginTM MDH sodium alginate, lot 281211, ISP Technologies Inc., San Diego, CA.
• LaponiteTM RD synthetic layered silicate
• Southern Clay Products, Inc. Gonzales, TX.
• inventive adhesive examples described herein typically consist of an adhesive polymer, associative thickener, water, and base.
• Such samples are prepared by combining the adhesive polymer, thickener, and water in a vessel and mixing well with a motor driven marine propeller to obtain a uniform composition. With continued stirring the base is added in a single charge and agitation continued until the adhesive composition is well mixed.
• ElvaceTM 737 was neutralized as follows. To 175 parts ElvaceTM 737 being agitated with a mechanical stirrer was added 0.56 ml NH 4 OH. The pH of the well mixed solution was 7.63, as measured by a pH meter. To 100 parts of neutralized ElvaceTM 737 being agitated with a mechanical stirrer was added 2.67 parts RhoplexTM ASE-60. After mixing well an additional 0.25 parts NH 4 OH solution was added and mixed in well to complete the preparation of Example 4 and provide an adhesive having pH of 7.12. Example 4 was characterized for Brookfield viscosity, set time, stringing, and rheology. The results are reported in Table 4. Comparative Examples C4, C5, C6, C7
• Comparative Examples C8, C9, ClO, CIl This series of Comparative Examples employ as the adhesive neutralized ElvaceTM 737 from Example 4.
• the adhesive, thickeners, and amounts of each are provided in Table 3. Samples were prepared by adding the thickener charge slowly to ElvaceTM 737 that was agitated with a mechanical stirrer and mixed for 15 minutes until the additive was well incorporated. After standing for 24 hr some of the samples appeared to contain small gel particles that could possibly be attributed to thickener that was either swollen or not completely dispersed initially. Each sample was mixed again for 15 minutes at which time all samples appeared very smooth.

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