EP0543983A4 - - Google Patents
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- Publication number
- EP0543983A4 EP0543983A4 EP19920913373 EP92913373A EP0543983A4 EP 0543983 A4 EP0543983 A4 EP 0543983A4 EP 19920913373 EP19920913373 EP 19920913373 EP 92913373 A EP92913373 A EP 92913373A EP 0543983 A4 EP0543983 A4 EP 0543983A4
- Authority
- EP
- European Patent Office
- Prior art keywords
- composition
- melt
- amount
- weight
- saccharide
- Prior art date
- Legal status (The legal status 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 status listed.)
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Classifications
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- 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
- C09J103/00—Adhesives based on starch, amylose or amylopectin or on their derivatives or degradation products
- C09J103/02—Starch; Degradation products thereof, e.g. dextrin
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- 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
- C08L2666/28—Non-macromolecular organic substances
Definitions
- This invention relates to compositions useful as hot melt adhesives and to methods related thereto.
- Hot melt adhesives produce a bond by cooling while in contact with surfaces wetted by a melt of the adhesive.
- a hot melt adhesive is a thermoplastic polymer that is heated to obtain a liquid of flowable viscosity which, after application, cools to form a solid. It is stated that while many of these adhesives are polymers of reasonable molecular weight, e.g .
- polyethylene other polyolefins or mixtures, ethylene/vinyl acetate copolymers, polya ides, polyesters, and block copolymer rubbers, it is common to incorporate low molecular weight additives for increased fluidity at application temperatures .
- Hot melt adhesives are used for bonding a variety of materials such as paper, wood, plastics, textiles, and other materials .
- One common use of hot melt adhesives is in the fabrication of corrugated paper board .
- Considerations surrounding the use of hot melt adhesives include the need for a bond having sufficient strength under conditions of shock, stress, high humidity, and extremes of temperature encountered in transportation and storage. I n addition, considerations relating to the application of the adhesive include the melt temperature, wetting time, initial tack, setting time, pot life and general handling qualities on automated application machinery.
- U. S. Patent No. 3,891 ,584 discloses a water-dispersible hot melt adhesive.
- the adhesive comprises a graft copolymer of a vinyl monomer and a polyalkylene oxide polymer with a polymerized ethylene oxide content of at least 50% by weight.
- the patent states that papers coated with such adhesives are recyclable without adverse effects .
- U. S . Patent No. 3,474,055 discloses a hot melt adhesive containing a high melting polyhydroxy compound.
- the patent notes the problems associated with repulping corrugated board paper stock that has been treated with a conventional hot melt adhesive.
- the patent states that improved repulpability is obtained by adding to an otherwise acceptable hot melt from 5 to 50 parts by weight of a water soluble crystalline polyhydroxy compound having a melting point of at least 100°C.
- the polyhydroxy compound is preferably selected from the group consisting of polyhydric alcohols and saccharides, sorbitol being an example of the former and D-glucose being an example of the latter.
- the patent also states that higher molecular weight oligosaccharides and polysaccharides are unsuitable because of amorphous structure or tendency to decompose under the conditions of preparation and use of the hot melt adhesive.
- This invention relates to a composition useful as a hot melt adhesive or component thereof comprising a major amount of a lower alkyl glycoside, and a minor amount of a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches, cold-water soluble dextrins, and maltodextrins, and mixtures of more than one of such members of said group, wherein :
- This invention relates to a heterogeneous blend comprised of particles of each of the above ingredients and to a substantially homogeneous melt-processed blend of the ingredients .
- a hot melt adhesive blend prepared from the ingredients set forth above has excellent functionality as an adhesive, particularly when used to bond paper materials, and yet will readily disperse in the aqueous medium used in repulping of the paper materials .
- the composition is compatible with conventional ethylene/vinyl acetate copolymers used as hot melt adhesives and, when used in admixture therewith, will improve the repulpability of paper materials bonded with the resulting hot melt adhesive.
- dextrose was used alone to provide a melt of the polysaccharide, the resulting adhesive bond was very susceptible to failure under conditions of high humidity. Substitution of an alkyl glycoside for the dextrose has been found to substantially eliminate adhesive failure under conditions of high humidity.
- This invention also relates to a composition useful as a hot melt adhesive or component thereof comprising a lower alkyl glycoside, dextrose, and a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches, cold-water soluble dextrins, and maltodextrins, and mixtures of more than one of such members of said group, wherein :
- the amount of said lower alkyl glycoside is sufficient in relation to the amount of dextrose in said composition to impart to said composition resistance to adhesive failure when used as a hot melt adhesive under conditions of elevated humidity
- This invention relates to a heterogeneous blend comprised of particles of each of the above ingredients and to a substantially homogeneous melt-processed blend of the ingredients .
- This application also relates to a method of adhering a cellulosic material to another substrate comprising interposing a melt of a blend composition between a cellulosic material and a substrate such that the cellulosic material and substrate are in contact with said melt and cooling said melt while in contact with said cellulosic material and said substrate, wherein said blend composition comprises :
- meltable saccharide selected from the group consisting of a mono-saccharide, a di-saccharide, a derivative of a mono-saccharide, a derivative of a di-saccharide, and mixtures of more than one of such members , and
- a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches , cold-water soluble dextrins , and maltodextrins , and mixtu res of more than one of such members of said group, wherein :
- said major amount of saccharide is sufficient to provide a flowable melt of said composition
- said degree of polymerization and said minor amount of said polysaccharide is sufficient to tackify said melt, but is insufficient to prevent said melt from flowing .
- the term "derivative" as applied to mono-saccha rides and di -saccha rides shall mean a compound derived from a mono-saccharide or di-saccharide, respectively .
- Preferred derivatives of mono- and di-saccha rides are glycoside derivatives or hydrogenation products, e.g. alkyl glucoside and sorbitol, respectively.
- This invention also relates to a method of manufacturing a shaped article comprising melting a composition of this invention , shaping said melt into the form of an article, and cooling said melt while in the shape of said article and to articles of manufacture produced by such methods .
- lower alkyl glycoside is meant a composition comprised predominantly of an acetal or ketal of a monosaccharide with a lower (i . e. C, -C 4 ) alkanol .
- monosaccharides from which the glycoside is derived include glucose, fructose, annose, galactose, talose, gulose, allose, altrose, idose, arabinose, xylose, lyxose, and ribose.
- the preferred glycosides are glucosides, i . e. derived from glucose, and most preferred is alpha-methyl glucoside.
- Lower alkyl glycosides are typically manufactured by heating the monosaccharide in the lower alkanol under conditions which cause the condensation of the alkanol with the monosaccharide and the liberation of water or by heating a polysaccharide form of the monosaccharide (e. g . starch in the case of glucosides) in a lower alkanol to cause a type of transglycosidation of the polysaccharide to the lower alkyl glycoside.
- a polysaccharide form of the monosaccharide e. g . starch in the case of glucosides
- lower aliphatic polyol such as the diols ethylene glycol and/or propylene glycol and the triol glycerol
- the product is a lower hydroxy-alkyl glycoside.
- lower hydroxy-alkyl glycosides are within the scope of the term "derivative" as applied to mono-saccharides and di-saccharides as used herein .
- Dextrose is available commercially in the anhydrous or monohydrate crystalline form, or as a syrup .
- Dextrose is obtained by the hydrolysis of starch , e. g . from corn .
- the production and properties of dextrose and corn syrups are discussed by H . M . Pancoast et al . , Handbook of Sugars, pp . 157-287 (AVI Publ . Co. , Westport, Connecticut, 2d ed . , 1980) , the disclosure of which is incorporated by reference herein .
- Substantially pure dextrose, as crystalline monohydrate or high solids syrup e.g .
- Corn syrups and corn syrup solids are characterized by dextrose equivalent (D. E. ) with the high conversion syrups having a high D. E. and a high concentration of dextrose. Lower conversion syrups and corn syrup solids (which are typically of low conversion) may be useful, but are not preferred.
- the polysaccharide component of the composition is selected from the group consisting of three individual classes of starch based materials. All of these materials are characterized by having been derived from starch in a manner such that the native polysaccharide has been subjected to partial hydrolysis to lower its molecular weight and, thus, the viscosity of a melt in which the polysaccharide is dispersed .
- the polysaccharide will be sufficiently depolymerized that the melt will exhibit a viscosity of not more than about 50,000 cps at 135°C, preferably not more than about 10,000 cps, e.g .
- the higher saccharides that may be present in the source of the dextrose may act as a secondary source of the polysaccharide purposely added to the composition .
- the dextrose that may be present in the source of polysaccharide, particularly the maltodextrins may act as a secondary source of the dextrose of the composition . i n the event that such secondary sources of polysaccharide and dextrose, respectively, are substantial, such sources should, of course, be taken into account when selecting the proper amount of the dextrose or polysaccharide which is purposely added .
- Converted pre-gelatinized starches are typically derived from native starch by hydrolysis , e. g .
- the starch may be in granular form during hydrolysis with acid, but it is hydrolyzed to a degree sufficient to reduce the viscosity of an aqueous dispersion of the starch , in which dispersion the starch is in gelatinized form . I n other words, the starch is made "thin-boiling" .
- Typical acid hydrolysis conditions will include slurrying starch with water to a slurry density of from about 1 . 1 g/ml to about 1 .2 g/ml and adding sufficient mineral acid (e. g . hydrochloric acid or sulfuric acid) to reduce the pH of the slurry to between about 1 .5 and about 2.5.
- the slurry is then heated under pressure to a temperature between about 105°C to about 125°C, for a time sufficient to give the desired degree of thinning (and which also serves to gelatinize or liquefy the starch) .
- the starch will typically have a Brookfield viscosity at about 30% solids of from about 600 to about 1000 cps .
- the starch can be isolated after neutralization of residual mineral acid by drying of the slurry, for example on heated rolls , to a moderate moisture content (e. g . 10% to 12% by weight) .
- Another class of materials derived from starch and which are useful as the polysaccharide are the cold-water soluble dextrins .
- the term “dextrin” is meant to refer to the products derived from essentially dry starch by the action of heat, or both heat and acid. Such materials are also referred to in the art as “pyrodext ins” .
- the manufacture of dextrins is extensively discussed in R. B . Evans et al . , “Production and Use of Starch Dextrins” ⁇ Starch : Chemistry and Technology, vol . I I , pp. 253-278 (R. L. Whistler, ed. , Academic Press Inc. , N. Y. , N . Y. , 1967) , the disclosure of which is incorporated by reference herein.
- dextrins There are generally four major steps in the production of dextrins, i. e. acidification (typically with about 0.05% to 0.15% of 0. 1 N HCI) , predrying (typically to about 1-5% moisture) , dextrin ization (heating at temperatures of about 95°C to 180°C) and cooling, although the class of dextrins known as British gums are made without acid.
- acidification typically with about 0.05% to 0.15% of 0. 1 N HCI
- predrying typically to about 1-5% moisture
- dextrin ization heating at temperatures of about 95°C to 180°C
- cooling although the class of dextrins known as British gums are made without acid.
- the white dextrins are heated at lower temperatures than the canary dextrins, and thus, longer periods of roasting of white dextrins are needed to obtain the same increase in solubility as a canary dextrin .
- the cold-water solubility of the dextrin should be substantial, e. g . greater than 50%, and the viscosity sufficiently reduced from the parent starch to yield the melt viscosity discussed above in connection with pre-gelatinized converted starches .
- the polysaccharide may also be a maltodextrin .
- Maltodextrins are prepared from starch by the hydrolysis with acid and/or enzyme of starch in an aqueous medium. Maltodextrins are generally characterized on the basis of dextrose equivalent (D.E.) which is an indication of the total reducing sugars present calculated as D-glucose on a dry weight basis. Unhydrolyzed starch has a D.E. of virtually zero while pure anhydrous D-glucose has a D.E. of 100. Maltodextrins have a D.E. of less than 20 from which it may be inferred that the average degree of polymerization (DP) of the polysaccharide will be greater than about 5. Maltodextrins having a D.E.
- DP average degree of polymerization
- a slurry of starch in water (e.g. at 40% by weight starch solids) is typically heated to liquefy the starch and then acid (e.g. HCI) is added to lower the pH of the slurry (e.g. to about 2) to catalyze the hydrolysis of the starch in the hot aqueous solution.
- acid e.g. HCI
- the acid is neutralized and the slurry is typically evaporated to higher solids for further hydrolysis, if desired, with enzyme, or for drying (e.g. by spray drying).
- the amounts of the components are chosen in relation to one another to yield the desired properties in the resulting hot melt adhesive.
- the alkyl glycoside, and dextrose if present, provides a flowable melt phase to the adhesive.
- the flowability of the adhesive melt is important in allowing the melt to wet the substrate to be bonded.
- the degree of polymerization of the polysaccharide will affect the viscosity, and thus flowability, of the melt as well .
- the selection of the precise amount of alkyl glycoside, and dextrose will be influenced by the choice of polysaccharide.
- the alkyl glycoside will comprise a major amount by weight (i . e.
- the mixture of alkyl glycoside and polysaccharide and the polysaccharide will comprise a minor amount by weight of the mixture (i .e. less than 50% by weight, typically from about 15% by weight to about 35% by weight) .
- the amount of polysaccharide should be sufficient to impart wet tack to the melt and to prevent excessive migration of the melt into porous substrates, such as uncoated paper.
- the combined weight of the alkyl glycoside and dextrose will be a major amount by weight of the mixture.
- the amount of alkyl glycoside should be sufficient in relation to the amount of dextrose to provide the desired degree of resistance to adhesive failure at elevated temperature and humidity.
- Such resistance can be measured by use of the customary test methods, e. g . TAPPI Method T 517 om-85 "Dynamic Strength of Flexible Barrier Material Seals” (Technical Association of the Pulp and Paper Industry, Atlanta, Georgia, 1985) and TAPPI Useful Method 556 "Static Load Strength of Flexible Barrier Material Seals", upon samples tested in an environment having conditions of elevated temperature and humidity (e.g. 100°F and 85% r. h . ) .
- the amount of dextrose can be adjusted to lower the temperature at which the compositions form a melt upon heating .
- This lower melt temperature will allow the adhesive to be kept at application temperatures for longer periods with lower risk of degrading the components of the melt, e. g . the polysaccharide.
- the ratio of alkyl glycoside to dextrose will be at least about 1 : 1 to about 5: 1 , and typically from about 2: 1 to about 4: 1 .
- the above components of the adhesive composition are commercially available as powdered, crystalline or granulated solids which are substantially dry, e. g containing no more than about 15% moisture.
- the crystalline monohydrate form of dextrose when substantially dry, will contain about 9% by weight moisture held within the crystal lattice.
- the polysaccharide will generally contain substantial moisture, e. g . 8% to 12% by weight, although a dextrin may have substantially less moisture, e. g . 3-5%.
- a melt of the ingredients will generally contain, at most, a nominal or trace amount of water, preferably less than 5% by weight.
- this invention relates to a mixture of the components in the form of a blend of particles, each particle comprised of one of the individual components, and thus, the blend is heterogeneous in nature.
- a blend is prepared by simply dry mixing individual dry ingredients .
- This dry blend can be used as a hot melt adhesive directly or it can be mixed with other additives or hot melt adhesives .
- this invention relates to a melt processed blend of the ingredients which , as a result of the melt processing, is a substantially homogeneous mixture.
- the composition may be in the form of rods, pellets, granules, or powders .
- the melt processed blend is prepared by heating a mixture of the desired amounts of the components to form a melt, e.g. to a temperature of from about 100°C to about 200°C, and stirring of the melt to achieve substantial homogeneity.
- the melt chamber is preferably vented to allow evaporation of the water that may be present in the composition .
- the process may comprise first melting the alkyl glycoside and/or dextrose followed by the addition of the polysaccharide.
- the components can be fed to an extruder, e. g. a vented, single-screw extruder, with a heating zone to melt the composition followed by a cooling zone to solidify the composition .
- an extruder e. g. a vented, single-screw extruder
- the composition can be deposited as a rod for use as an adhesive or the composition can be pelleted, e. g. through the use of a reciprocating or rotating knife positioned at the mouth of the extruder barrel .
- the composition can then be packed and/or stored, as desired, prior to reheating for use as a hot melt adhesive.
- the hot melt adhesive may contain additional components .
- Typical additives include tackifying resins (e.g . terpene resins and/or rosin derivatives) , plasticizers, flow modifiers, fillers, pigments, and/or dyestuffs, generally in a minor amount by weight (i . e. less than 50% by weight of the adhesive) .
- Particularly useful additives are waxes or oils .
- Particularly preferred waxes are the hydrocarbon waxes such as paraffin waxes, microcrystalline waxes , polyethylene waxes, Fischer-Tropsch waxes , and/or chemically modified hydrocarbon waxes (e. g . oxidized polyethylene waxes) .
- Waxes and their sources are more particularly described in Encyclopedia of Chemical Technology, vol . 24, pp. 466-481 (Kirk-Othmer, eds . , John Wiley & Sons, Inc. , N . Y. , N . Y . , 3rd ed . , 1984) , the disclosure of which is incorporated herein by reference.
- the amount of wax added, if any, will typically range from about 5% to about 20% by weight of the hot melt adhesive.
- hot melt compositions of this invention can be used in admixture with conventional hot melt adhesives, i.e. thermoplastic polymers, e.g. ethylene/vinyl acetate copolymers (e. g . ELVAX, available from E. I . DuPont de Nemours, Wilmington , Delaware) , polyethylene, other polyolefins, polyamides, polyesters, and block copolymer rubbers .
- thermoplastic polymers will generally comprise a minor amount by weight of the hot melt adhesive (i . e. iess than 50% by weight) , but may be present in a major amount depending upon the properties desired in the hot melt and the degree of repulpability that is needed in the chosen use of the adhesive.
- thermoplastic polymers will generally have a melting point between about 100°C and about 200°C .
- compositions of this invention are used as a hot melt adhesive.
- the composition while in the form of a flowable melt, is interposed between two surfaces to be bonded .
- the two surfaces are mated and the composition is allowed to at least partially solidify after wetting the two surfaces and thus form a bond between the surfaces .
- the precise amount of adhesive applied per unit of area of the bond will vary, but typical values range from about 0.1 to about 0.3 grams per square inch of adhesive bond, most typically from about 0.15 to about 0.25 g/sq. in .
- the surface of the substrate actually bonded is typically only a fraction, e. g . 10%, of the area of the surfaces that are mated as a result of the bond, e. g. in a closure of box flaps .
- the temperature to which the composition need be heated to form a flowable melt will also vary depending upon the precise formulation thereof, but will typically be between about 100°C to about 200°C.
- a melt of the adhesive is applied to one of the surfaces to be bonded, and the second surface is then mated to the first with the melt positioned between the surfaces .
- the mode of application of the melt may vary, depending upon the desired pattern of adhesive and the viscosity of the melt, e.g. melts of relatively low viscosity may be applied by spraying, melts of moderate viscosity may be applied by extrusion, and melts of high viscosity may be applied by roll coating .
- the melt is fed between prepositioned surfaces by gravity, capillary wicking, pressure, or vacuum feeding techniques.
- a solid form of the adhesive e.g. a powder of film, is placed between the surfaces and heat is applied to the adhesive to melt it.
- the composition used as an adhesive is a mixture of a major amount of a meltable saccharide and a minor amount of a polysaccharide.
- the group of meltable saccharide includes the alkyl glycosides and the saccharides discussed above. This group also includes other sugars, e.g. sucrose, fructose, lactose, and maltose, and the sugar alcohols, e.g. sorbitol, mannitol, xylitol, dulcitoi, mannitol, and lactitol. Methods of obtaining sugar alcohols are described in F.
- compositions of this invention may be used to bond a variety of substrates, but are most advantageously used to bond cellulosic substrates, e.g. paper, paperboard, corrugated board, chipboard, and the like.
- the adhesive finds particular utility in case and carton sealing applications wherein the adhesive is used to bond the flaps of paperboard or corrugated board containers and thereby close the case or carton.
- compositions of this invention can also be used to prepare shaped articles that are largely biodegradable.
- shaped articles is meant items that have utility by virtue of their structural dimensions of height, width and depth .
- Such articles may have a variety of geometric shapes and may be either solid, hollow, open-celled foams, closed-cell foams, and the like.
- Such articles include bottles, sheets, films, wrappings, pipes, rods, spheres, cubes, squares, tiles, mats, laminated films, bags, capsules (e.g. pharmaceutical capsules) , granules, powders, or foams .
- the techniques employed to form such articles may include casting, injection molding, blow molding, extrusion, co-extrusion, spray coating, dip coating, roller coating, curtain coating, and the like. Further, ingots, rods, or films of the composition can, if heated above their glass transition temperature, but below their melt temperature, be physically manipulated (e. g. by roll forming, stamping and so on) and, thus, articles can be formed in this manner.
- compositions of this invention will be melted, molded, and cooled to form solid cylinders that are useful as hot melt glue sticks .
- Such cylinders are typically from about 2 mm to about 2 cm in diameter and from about 2 cm to about 20 cm in length .
- These cylinders can then be inserted into commercially available hot melt glue "guns" which have a heated chamber that receives the cylinder. In operation, the cylinder is heated in the chamber and the melt dispensed from the "muzzle" of the gun .
- the melt range reported in the examples is the range over which the melt processed blend first began to soften to the temperature at which the melt was fully liquified .
- the softening points reported in the examples were measured according to ASTM Method E28 "Test Method for Softening Point by Ring-and-Ball Apparatus" (American Society for Testing and Materials, Philadelphia, Pennsylvania, 1982) .
- the melt viscosity was a dynamic viscosity as measured by Bohlin Rheometer, model VOR, available from Bohlin Reologi, I nc. , Cranbury, New Jersey .
- Bonds for shear testing were prepared by remelting the adhesive to a temperature above its melt range, and applying the melt between coated cereal box stock bonded coated side to uncoated side to simulate a flap closure of a cereal box .
- the adhesive was applied at the rate of approximately 0.2 grams per square inch .
- the shear testing for Examples 1-14 was performed in accordance with TAPPI Method T 517 om-85 "Dynamic Strength of Flexible Barrier Material Seals" and TAPPI Useful Method 556 "Static Load Strength of Flexible Barrier Material Seals".
- the Dynamic Shear value reported below is the average load needed to cause failure and the Static Load Shear value reported below is the time until failure of a one square inch bond tested with a load of 300 grams.
- Dextrin 230 a pyrodextrin available from A.E. Staley Mfg. Co., Decatur, Illinois, as STADEX® 230.
- Dextrin 94 a pyrodextrin available from A.E. Staley Mfg. Co., Decatur, Illinois, as STADEX® 94.
- Acid-modified Starch an acid depolymerized
- Maltodextrin 10 a 10 D.E. maltodextrin available from A.E. Staley Mfg. Co. as STAR-DRI® 10.
- Maltodextrin 1 a 1 D.E. maltodextrin available from A.E. Staley Mfg. Co. as STAR-DRI® 1.
- Corn Syrup Solids 24 a low conversion corn syrup solids having a D.E. of 24 available from A.E. Staley Mfg. Co. as STAR-DRI 24R
- Corn Syrup Solids 35 a low conversion corn syrup solids having a D.E. of 35 available from A.E. Staley Mfg. Co. as STAR-DRI 35R
- Corn Syrup Solids 42 a low conversion corn syrup solids having a D.E. of 42 available from A.E. Staley Mfg. Co. as STAR-DRI 42C
- Methyl Glucoside alpha-methyl glucoside available from Grain Processing Corporation, Muscatine, Iowa, as STA-MEG® 104.
- Dextrose dextrose monohydrate available from A.E. Staley Mfg. Co. as STALEYDEX® 333.
- Paraffin Wax a paraffin wax having a melt range of from 48°C to 68°C, available from Boyle-Midway, Inc., N.Y., N.Y.
- C-4040 Wax a saturated straight chain hydrocarbon polymer available from Petrolite Corporation
- Wax an oxidized hydrocarbon available from Petrolite Corporation as PETROLITE® C-5500.
- EVA 1 an ethylene/vinyl acetate copolymer
- EVA 2 an ethylene/vinyl acetate copolymer
- EBAC an ethylene/n-butyl acrylate copolymer available from Quantum Chemical Corp . , Cincinnati, Ohio, as EA 89822.
- Methyl Glucoside 50 Dextrose 15 C4040 Wax 5 C5500 Wax 10
- Static Load Shear at 100°F/85% r.h./300 gm. wt. Failed between 3 days and 5 days
- Viscosity at 121°C 12,800 cps at 135°C 7,590 cps at 150°C
- Viscosity at 135°C at 150°C 150,000 cps at 163°C 5,260 cps
- Viscosity at 135°C 150,000 cps at 150°C 86,000 cps at 163°C 25,000 cps
- Viscosity at 135°C 3,590,000 cps at 150°C cps at 163°C 76,300 cps
- Viscosity at 135°C at 150°C 47,300 cps at 163°C 31,500 cps
- Static Load Shear at 100°F/85% r.h./300 gm. wt. : Failed at ⁇ l/2 hr.
- Viscosity at 149°C 1,288 cps at 143°C 1,963 cps at 138°C off scale at 133°C off scale
- Viscosity at 149°C 8,638 cps at 143°C 127,500 cps at 138°C off scale at 133°C off scale
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Abstract
A hot melt adhesive composition and method of use thereof is provided. The hot melt adhesive contains a major amount of a meltable saccharide, e.g. a lower alkyl glycoside and a minor amount of a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches, cold-water soluble dextrins, and maltodextrins, and mixtures of more than one of such members of said group. The amount of meltable saccharide is sufficient to provide a flowable melt of said composition and the degree of polymerization and said minor amount of the polysaccharide are sufficient to tackify said melt, but are insufficient to prevent said melt from flowing. Preferred compositions also contain a minor amount of dextrose in addition to an alkyl glycoside. The composition can be used alone as a hot melt or in admixture with other hot melt materials, e.g. ethylene/vinyl acetate copolymers. The composition is advantageously used to bond cellulosic substrates which are, as a result, particularly susceptible to repulping, and thus recycling.
Description
HOT MELT ADHESIVE COMPOSITION AND METHOD
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is a continuation-in-part of
U . S . application (Case No. 2004371 ) filed May 27, 1992 and a continuation-in-part of U . S . application Serial No.
07/714,789, filed June 13, 1991 , the disclosures of which are incorporated herein by reference.
FIELD OF THE INVENTION
This invention relates to compositions useful as hot melt adhesives and to methods related thereto.
BACKGROUND OF THE INVENTION
Hot melt adhesives produce a bond by cooling while in contact with surfaces wetted by a melt of the adhesive. As defined in S . Temin, "Adhesive Compositions", Encyclopedia of Polymer Science and Technology, vol. 1 , pp . 547-577 (John Wiley & Sons, I nc. , N.Y. , N .Y. , rev. ed . , 1985) , a hot melt adhesive is a thermoplastic polymer that is heated to obtain a liquid of flowable viscosity which, after application, cools to form a solid. It is stated that while many of these adhesives are polymers of reasonable molecular weight, e.g . based on polyethylene, other polyolefins or mixtures, ethylene/vinyl acetate copolymers, polya ides, polyesters, and block copolymer rubbers, it is common to incorporate low molecular weight additives for increased fluidity at application temperatures .
Hot melt adhesives are used for bonding a variety of materials such as paper, wood, plastics, textiles, and other materials . One common use of hot
melt adhesives is in the fabrication of corrugated paper board . Considerations surrounding the use of hot melt adhesives include the need for a bond having sufficient strength under conditions of shock, stress, high humidity, and extremes of temperature encountered in transportation and storage. I n addition, considerations relating to the application of the adhesive include the melt temperature, wetting time, initial tack, setting time, pot life and general handling qualities on automated application machinery.
There is great and still growing interest in the recycling of materials, particularly those materials that typically have a limited duration of use, e. g . packaging materials such as corrugated boxes , see C . Rowland, "New Corrugated Box Rules . . . ", Pulp and Paper, December 1990, pp . 120-126. Thus, paper and related pulp products are commonly regarded as recyclable materials . These materials are generally repulped as part of the recycling process . Repulping generally involves heating and vigorously agitating an aqueous slurry of the paper material to cause its disintegration into its component fibers . If the paper material is associated with an adhesive that is not dispersible in water, the repulping may be impeded and the paper fibers will tend to break away from the adhesive leaving large lumps or films of adhesive mixed with the paper fibers . These lumps or films of adhesive can foul the repulping equipment or the equipment used to make paper from the repulped fibers and may be retained in the resulting recycled paper as blotches and other irregularities .
U. S. Patent No. 3,891 ,584 (Ray-Chaudhuri et al . ) discloses a water-dispersible hot melt adhesive. The adhesive comprises a graft copolymer of a vinyl monomer and a polyalkylene oxide polymer with a polymerized ethylene oxide content of at least 50% by weight. The patent states that papers coated with such adhesives are recyclable without adverse effects .
U. S . Patent No. 3,474,055 (Dooley) discloses a hot melt adhesive containing a high melting polyhydroxy compound. The patent notes the problems associated with repulping corrugated board paper stock that has been treated with a conventional hot melt adhesive. The patent states that improved repulpability is obtained by adding to an otherwise acceptable hot melt from 5 to 50 parts by weight of a water soluble crystalline polyhydroxy compound having a melting point of at least 100°C. It is further stated that the polyhydroxy compound is preferably selected from the group consisting of polyhydric alcohols and saccharides, sorbitol being an example of the former and D-glucose being an example of the latter. The patent also states that higher molecular weight oligosaccharides and polysaccharides are unsuitable because of amorphous structure or tendency to decompose under the conditions of preparation and use of the hot melt adhesive.
SUMMARY OF THE INVENTION
This invention relates to a composition useful as a hot melt adhesive or component thereof comprising a major amount of a lower alkyl glycoside, and a minor amount of a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches, cold-water soluble dextrins, and maltodextrins, and mixtures of more than one of such members of said group, wherein :
(i) said major amount of alkyl glycoside is sufficient to provide a flowable melt of said composition, and
(ii) the degree of polymerization and said minor amount of said polysaccharide is sufficient to tackify said melt, but is insufficient to prevent said melt from flowing . This invention relates to a heterogeneous blend comprised of particles of each of the above ingredients and to a substantially homogeneous melt-processed blend of the ingredients .
It has been found that a hot melt adhesive blend prepared from the ingredients set forth above has excellent functionality as an adhesive, particularly when used to bond paper materials, and yet will readily disperse in the aqueous medium used in repulping of the paper materials . I n addition to acting as the hot melt adhesive itself, the composition is compatible with conventional ethylene/vinyl acetate copolymers used as hot melt adhesives and, when used in admixture therewith, will improve the repulpability of paper materials bonded with the resulting hot melt adhesive. It was found that when dextrose was used alone to provide a melt of the polysaccharide, the resulting
adhesive bond was very susceptible to failure under conditions of high humidity. Substitution of an alkyl glycoside for the dextrose has been found to substantially eliminate adhesive failure under conditions of high humidity.
This invention also relates to a composition useful as a hot melt adhesive or component thereof comprising a lower alkyl glycoside, dextrose, and a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches, cold-water soluble dextrins, and maltodextrins, and mixtures of more than one of such members of said group, wherein :
(i) the amounts of dextrose and lower alkyl glycoside are sufficient to provide a flowable' melt of said composition,
(ii) the amount of said lower alkyl glycoside is sufficient in relation to the amount of dextrose in said composition to impart to said composition resistance to adhesive failure when used as a hot melt adhesive under conditions of elevated humidity, and
(iii) the degree of polymerization and the amount of said polysaccharide is sufficient to tackify said melt, but is insufficient to prevent said melt from flowing. This invention relates to a heterogeneous blend comprised of particles of each of the above ingredients and to a substantially homogeneous melt-processed blend of the ingredients .
It has been found that the use of dextrose with an alkyl glycoside to provide a melt will generally yield a composition having a lower melt temperature.
This allows for a longer pot life for the resulting adhesive without degradation of the adhesive
components . Thus , under production circumstances which require an extended pot life, the use of dextrose with an alkyl glycoside is preferred .
This application also relates to a method of adhering a cellulosic material to another substrate comprising interposing a melt of a blend composition between a cellulosic material and a substrate such that the cellulosic material and substrate are in contact with said melt and cooling said melt while in contact with said cellulosic material and said substrate, wherein said blend composition comprises :
(a) a major amount of a meltable saccharide selected from the group consisting of a mono-saccharide, a di-saccharide, a derivative of a mono-saccharide, a derivative of a di-saccharide, and mixtures of more than one of such members , and
(b) a minor amount of a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches , cold-water soluble dextrins , and maltodextrins , and mixtu res of more than one of such members of said group, wherein :
(i ) said major amount of saccharide is sufficient to provide a flowable melt of said composition , and (ii) the degree of polymerization and said minor amount of said polysaccharide is sufficient to tackify said melt, but is insufficient to prevent said melt from flowing .
As used herein , the term "derivative" as applied to mono-saccha rides and di -saccha rides shall mean a compound derived from a mono-saccharide or di-saccharide, respectively . Preferred derivatives of mono- and di-saccha rides are glycoside derivatives or
hydrogenation products, e.g. alkyl glucoside and sorbitol, respectively.
This invention also relates to a method of manufacturing a shaped article comprising melting a composition of this invention , shaping said melt into the form of an article, and cooling said melt while in the shape of said article and to articles of manufacture produced by such methods .
DETAILED DESCRIPTION OF THE INVENTION
One of the components of the composition is a lower alkyl glycoside. By "lower alkyl glycoside" is meant a composition comprised predominantly of an acetal or ketal of a monosaccharide with a lower (i . e. C, -C4) alkanol . Examples of monosaccharides from which the glycoside is derived include glucose, fructose, annose, galactose, talose, gulose, allose, altrose, idose, arabinose, xylose, lyxose, and ribose. The preferred glycosides are glucosides, i . e. derived from glucose, and most preferred is alpha-methyl glucoside. Lower alkyl glycosides are typically manufactured by heating the monosaccharide in the lower alkanol under conditions which cause the condensation of the alkanol with the monosaccharide and the liberation of water or by heating a polysaccharide form of the monosaccharide (e. g . starch in the case of glucosides) in a lower alkanol to cause a type of transglycosidation of the polysaccharide to the lower alkyl glycoside. If a lower aliphatic polyol (such as the diols ethylene glycol and/or propylene glycol and the triol glycerol) is used condensed with the monosaccharide, the product is a lower hydroxy-alkyl glycoside. As such , lower hydroxy-alkyl glycosides are within the scope of the term "derivative" as applied to mono-saccharides and di-saccharides as used herein .
Another component of the preferred adhesive compositions of this invention is dextrose. Dextrose is available commercially in the anhydrous or monohydrate crystalline form, or as a syrup . Dextrose is obtained by the hydrolysis of starch , e. g . from corn . The production and properties of dextrose and corn syrups are discussed by H . M . Pancoast et al . , Handbook of
Sugars, pp . 157-287 (AVI Publ . Co. , Westport, Connecticut, 2d ed . , 1980) , the disclosure of which is incorporated by reference herein . Substantially pure dextrose, as crystalline monohydrate or high solids syrup (e.g . about 70% by weight) , is preferred for use herein . Corn syrups and corn syrup solids are characterized by dextrose equivalent (D. E. ) with the high conversion syrups having a high D. E. and a high concentration of dextrose. Lower conversion syrups and corn syrup solids (which are typically of low conversion) may be useful, but are not preferred.
The polysaccharide component of the composition is selected from the group consisting of three individual classes of starch based materials. All of these materials are characterized by having been derived from starch in a manner such that the native polysaccharide has been subjected to partial hydrolysis to lower its molecular weight and, thus, the viscosity of a melt in which the polysaccharide is dispersed . In general, the polysaccharide will be sufficiently depolymerized that the melt will exhibit a viscosity of not more than about 50,000 cps at 135°C, preferably not more than about 10,000 cps, e.g . a dynamic viscosity as determined by Bohlin Rheometer, model VOR, available from Bohlin Reologi, I nc. , Cranbury, New Jersey. Further, the form of the polysaccharide has been converted from the native granular state to a form which will allow the polysaccharide to disperse in the high temperature, but low moisture, environment of a melt of the ingredients .
As can be appreciated, the higher saccharides that may be present in the source of the dextrose may act as a secondary source of the polysaccharide
purposely added to the composition . Conversely, the dextrose that may be present in the source of polysaccharide, particularly the maltodextrins, may act as a secondary source of the dextrose of the composition . i n the event that such secondary sources of polysaccharide and dextrose, respectively, are substantial, such sources should, of course, be taken into account when selecting the proper amount of the dextrose or polysaccharide which is purposely added . Converted pre-gelatinized starches are typically derived from native starch by hydrolysis , e. g . with enzymes or aqueous acid . The starch may be in granular form during hydrolysis with acid, but it is hydrolyzed to a degree sufficient to reduce the viscosity of an aqueous dispersion of the starch , in which dispersion the starch is in gelatinized form . I n other words, the starch is made "thin-boiling" . Typical acid hydrolysis conditions will include slurrying starch with water to a slurry density of from about 1 . 1 g/ml to about 1 .2 g/ml and adding sufficient mineral acid (e. g . hydrochloric acid or sulfuric acid) to reduce the pH of the slurry to between about 1 .5 and about 2.5. The slurry is then heated under pressure to a temperature between about 105°C to about 125°C, for a time sufficient to give the desired degree of thinning (and which also serves to gelatinize or liquefy the starch) . The starch will typically have a Brookfield viscosity at about 30% solids of from about 600 to about 1000 cps . The starch can be isolated after neutralization of residual mineral acid by drying of the slurry, for example on heated rolls , to a moderate moisture content (e. g . 10% to 12% by weight) .
Another class of materials derived from starch and which are useful as the polysaccharide are the cold-water soluble dextrins . As used herein, the term "dextrin" is meant to refer to the products derived from essentially dry starch by the action of heat, or both heat and acid. Such materials are also referred to in the art as "pyrodext ins" . The manufacture of dextrins is extensively discussed in R. B . Evans et al . , "Production and Use of Starch Dextrins"^ Starch : Chemistry and Technology, vol . I I , pp. 253-278 (R. L. Whistler, ed. , Academic Press Inc. , N. Y. , N . Y. , 1967) , the disclosure of which is incorporated by reference herein.
There are generally four major steps in the production of dextrins, i. e. acidification (typically with about 0.05% to 0.15% of 0. 1 N HCI) , predrying (typically to about 1-5% moisture) , dextrin ization (heating at temperatures of about 95°C to 180°C) and cooling, although the class of dextrins known as British gums are made without acid. Of the two types of dextrins prepared with acid, the white dextrins are heated at lower temperatures than the canary dextrins, and thus, longer periods of roasting of white dextrins are needed to obtain the same increase in solubility as a canary dextrin . In general, the cold-water solubility of the dextrin should be substantial, e. g . greater than 50%, and the viscosity sufficiently reduced from the parent starch to yield the melt viscosity discussed above in connection with pre-gelatinized converted starches . The polysaccharide may also be a maltodextrin .
Maltodextrins are prepared from starch by the hydrolysis with acid and/or enzyme of starch in an aqueous medium. Maltodextrins are generally characterized on
the basis of dextrose equivalent (D.E.) which is an indication of the total reducing sugars present calculated as D-glucose on a dry weight basis. Unhydrolyzed starch has a D.E. of virtually zero while pure anhydrous D-glucose has a D.E. of 100. Maltodextrins have a D.E. of less than 20 from which it may be inferred that the average degree of polymerization (DP) of the polysaccharide will be greater than about 5. Maltodextrins having a D.E. as low as about 1 (i.e. an average DP of about 100) are commercially available. Starch hydrolysates having a D.E. above 20, e.g. low conversion (D.E. of 20-45) corn syrup solids, may also be useful as the polysaccharide, particularly in compositions which otherwise have no added dextrose. The production of maltodextrins is discussed in
R. L. Whistler, Starch: Chemistry and Technology, pp. 614-623 (2nd ed., Academic Press Inc., N.Y., N.Y., 1984), the disclosure of which is incorporated herein by reference. A slurry of starch in water (e.g. at 40% by weight starch solids) is typically heated to liquefy the starch and then acid (e.g. HCI) is added to lower the pH of the slurry (e.g. to about 2) to catalyze the hydrolysis of the starch in the hot aqueous solution. The acid is neutralized and the slurry is typically evaporated to higher solids for further hydrolysis, if desired, with enzyme, or for drying (e.g. by spray drying).
The amounts of the components are chosen in relation to one another to yield the desired properties in the resulting hot melt adhesive. The alkyl glycoside, and dextrose if present, provides a flowable melt phase to the adhesive. The flowability of the adhesive melt is important in allowing the melt to wet the substrate to be
bonded. As noted above, the degree of polymerization of the polysaccharide will affect the viscosity, and thus flowability, of the melt as well . Thus, the selection of the precise amount of alkyl glycoside, and dextrose, will be influenced by the choice of polysaccharide. In general, the alkyl glycoside will comprise a major amount by weight (i . e. at least 50% by weight) of the mixture of alkyl glycoside and polysaccharide and the polysaccharide will comprise a minor amount by weight of the mixture (i .e. less than 50% by weight, typically from about 15% by weight to about 35% by weight) . The amount of polysaccharide should be sufficient to impart wet tack to the melt and to prevent excessive migration of the melt into porous substrates, such as uncoated paper. Likewise, in mixtures of alkyl glycoside, dextrose, and polysaccharide, the combined weight of the alkyl glycoside and dextrose will be a major amount by weight of the mixture.
In compositions which contain both alkyl glycoside and dextrose, the amount of alkyl glycoside should be sufficient in relation to the amount of dextrose to provide the desired degree of resistance to adhesive failure at elevated temperature and humidity. Such resistance can be measured by use of the customary test methods, e. g . TAPPI Method T 517 om-85 "Dynamic Strength of Flexible Barrier Material Seals" (Technical Association of the Pulp and Paper Industry, Atlanta, Georgia, 1985) and TAPPI Useful Method 556 "Static Load Strength of Flexible Barrier Material Seals", upon samples tested in an environment having conditions of elevated temperature and humidity (e.g. 100°F and 85% r. h . ) . As noted above, the amount of dextrose can be adjusted to lower the temperature at which the
compositions form a melt upon heating . This lower melt temperature will allow the adhesive to be kept at application temperatures for longer periods with lower risk of degrading the components of the melt, e. g . the polysaccharide. Generally, the ratio of alkyl glycoside to dextrose will be at least about 1 : 1 to about 5: 1 , and typically from about 2: 1 to about 4: 1 .
The above components of the adhesive composition are commercially available as powdered, crystalline or granulated solids which are substantially dry, e. g containing no more than about 15% moisture. The crystalline monohydrate form of dextrose, when substantially dry, will contain about 9% by weight moisture held within the crystal lattice. The polysaccharide will generally contain substantial moisture, e. g . 8% to 12% by weight, although a dextrin may have substantially less moisture, e. g . 3-5%. Thus, a melt of the ingredients will generally contain, at most, a nominal or trace amount of water, preferably less than 5% by weight. I n certain embodiments, this invention relates to a mixture of the components in the form of a blend of particles, each particle comprised of one of the individual components, and thus, the blend is heterogeneous in nature. Such a blend is prepared by simply dry mixing individual dry ingredients . This dry blend can be used as a hot melt adhesive directly or it can be mixed with other additives or hot melt adhesives .
In other embodiments, this invention relates to a melt processed blend of the ingredients which , as a result of the melt processing, is a substantially homogeneous mixture. I n this embodiment, the composition may be in the form of rods, pellets, granules, or powders . The melt processed blend is
prepared by heating a mixture of the desired amounts of the components to form a melt, e.g. to a temperature of from about 100°C to about 200°C, and stirring of the melt to achieve substantial homogeneity. The melt chamber is preferably vented to allow evaporation of the water that may be present in the composition . Alternatively, the process may comprise first melting the alkyl glycoside and/or dextrose followed by the addition of the polysaccharide. In the event a syrup is used as a source of the dextrose, most, if not all, of the water of the syrup will be evaporated during this melt blend processing. The melt is then cooled below its melting range to solidify. Such processing may be batch or continuous . .' For example, the components can be fed to an extruder, e. g. a vented, single-screw extruder, with a heating zone to melt the composition followed by a cooling zone to solidify the composition . Upon exit from the extruder barrel, the composition can be deposited as a rod for use as an adhesive or the composition can be pelleted, e. g. through the use of a reciprocating or rotating knife positioned at the mouth of the extruder barrel . The composition can then be packed and/or stored, as desired, prior to reheating for use as a hot melt adhesive.
The hot melt adhesive may contain additional components . Typical additives include tackifying resins (e.g . terpene resins and/or rosin derivatives) , plasticizers, flow modifiers, fillers, pigments, and/or dyestuffs, generally in a minor amount by weight (i . e. less than 50% by weight of the adhesive) . Particularly useful additives are waxes or oils . Particularly preferred waxes are the hydrocarbon waxes such as paraffin
waxes, microcrystalline waxes , polyethylene waxes, Fischer-Tropsch waxes , and/or chemically modified hydrocarbon waxes (e. g . oxidized polyethylene waxes) . Waxes and their sources are more particularly described in Encyclopedia of Chemical Technology, vol . 24, pp. 466-481 (Kirk-Othmer, eds . , John Wiley & Sons, Inc. , N . Y. , N . Y . , 3rd ed . , 1984) , the disclosure of which is incorporated herein by reference. The amount of wax added, if any, will typically range from about 5% to about 20% by weight of the hot melt adhesive.
Further, the hot melt compositions of this invention can be used in admixture with conventional hot melt adhesives, i.e. thermoplastic polymers, e.g. ethylene/vinyl acetate copolymers (e. g . ELVAX, available from E. I . DuPont de Nemours, Wilmington , Delaware) , polyethylene, other polyolefins, polyamides, polyesters, and block copolymer rubbers . Such conventional hot melt adhesives will generally comprise a minor amount by weight of the hot melt adhesive (i . e. iess than 50% by weight) , but may be present in a major amount depending upon the properties desired in the hot melt and the degree of repulpability that is needed in the chosen use of the adhesive. Such thermoplastic polymers will generally have a melting point between about 100°C and about 200°C .
The compositions of this invention are used as a hot melt adhesive. The composition , while in the form of a flowable melt, is interposed between two surfaces to be bonded . The two surfaces are mated and the composition is allowed to at least partially solidify after wetting the two surfaces and thus form a bond between the surfaces . The precise amount of adhesive applied per unit of area of the bond will vary, but typical
values range from about 0.1 to about 0.3 grams per square inch of adhesive bond, most typically from about 0.15 to about 0.25 g/sq. in . Of course, it should be noted that the surface of the substrate actually bonded is typically only a fraction, e. g . 10%, of the area of the surfaces that are mated as a result of the bond, e. g. in a closure of box flaps . The temperature to which the composition need be heated to form a flowable melt will also vary depending upon the precise formulation thereof, but will typically be between about 100°C to about 200°C.
Various techniques may be used to obtain a melt of the adhesive interposed between the surfaces to be bonded . Techniques of bonding with hot melts are discussed in Encyclopedia of Polymer Science and Engineering, vol . 1 , pp . 547-552 (John Wiley & Sons, Inc. , N . Y. , N . Y. 1984) , and Encyclopedia of Chemical Technology, vol . 1 , pp . 499-501 (Kirk-Othmer eds. , John Wiley & Sons, Inc. , N. Y. , N . Y. , 3rd ed. , 1984) , the disclosures of which are incorporated herein by reference. I n general , the adhesive is applied to the substrates by one of three general methods, or variations thereof.
In the first method, a melt of the adhesive is applied to one of the surfaces to be bonded, and the second surface is then mated to the first with the melt positioned between the surfaces . The mode of application of the melt may vary, depending upon the desired pattern of adhesive and the viscosity of the melt, e.g. melts of relatively low viscosity may be applied by spraying, melts of moderate viscosity may be applied by extrusion, and melts of high viscosity may be applied by roll coating . I n the second method, the melt
is fed between prepositioned surfaces by gravity, capillary wicking, pressure, or vacuum feeding techniques. In the third method, a solid form of the adhesive, e.g. a powder of film, is placed between the surfaces and heat is applied to the adhesive to melt it.
In the broadest embodiments of the method of this invention, the composition used as an adhesive is a mixture of a major amount of a meltable saccharide and a minor amount of a polysaccharide. The group of meltable saccharide includes the alkyl glycosides and the saccharides discussed above. This group also includes other sugars, e.g. sucrose, fructose, lactose, and maltose, and the sugar alcohols, e.g. sorbitol, mannitol, xylitol, dulcitoi, mannitol, and lactitol. Methods of obtaining sugar alcohols are described in F. Benson, "Alcohols, Polyhydric (Sugar)", Encyclopedia of Chemical Technology, vol. 1, pp. 754-778, (John Wiley & Sons, Inc. N.Y., N.Y., Kirk-Othmer, eds., 3d ed., 1978), the disclosure of which is incorporated by reference. The compositions of this invention may be used to bond a variety of substrates, but are most advantageously used to bond cellulosic substrates, e.g. paper, paperboard, corrugated board, chipboard, and the like. The adhesive finds particular utility in case and carton sealing applications wherein the adhesive is used to bond the flaps of paperboard or corrugated board containers and thereby close the case or carton. The case or carton, after use, is then particularly susceptible to repulping. The compositions of this invention can also be used to prepare shaped articles that are largely biodegradable. By shaped articles is meant items that have utility by virtue of their structural dimensions of
height, width and depth . Such articles may have a variety of geometric shapes and may be either solid, hollow, open-celled foams, closed-cell foams, and the like. Such articles include bottles, sheets, films, wrappings, pipes, rods, spheres, cubes, squares, tiles, mats, laminated films, bags, capsules (e.g. pharmaceutical capsules) , granules, powders, or foams . The techniques employed to form such articles may include casting, injection molding, blow molding, extrusion, co-extrusion, spray coating, dip coating, roller coating, curtain coating, and the like. Further, ingots, rods, or films of the composition can, if heated above their glass transition temperature, but below their melt temperature, be physically manipulated (e. g. by roll forming, stamping and so on) and, thus, articles can be formed in this manner.
In particular embodiments, the compositions of this invention will be melted, molded, and cooled to form solid cylinders that are useful as hot melt glue sticks . Such cylinders are typically from about 2 mm to about 2 cm in diameter and from about 2 cm to about 20 cm in length . These cylinders can then be inserted into commercially available hot melt glue "guns" which have a heated chamber that receives the cylinder. In operation, the cylinder is heated in the chamber and the melt dispensed from the "muzzle" of the gun .
The following examples will illustrate the invention and should not be construed to limit the scope thereof . All parts, percentages and ratios recited in this specification are by weight unless otherwise noted in context.
EXAMPLES
In all of the examples, the following procedures of adhesive preparation, application and testing were employed .
All of the ingredients were first dry blended until well mixed . After dry blending, the mixture was fed at maximum rate into a fou r stage, single screw extruder available as the Bonnot Model 2 and 1/4" from The Bonnot Co. , Kent, Ohio. This extruder had a barrel length of 44 inches, a screw diameter of 2 and 1/4 inches, and a screw speed of 36 rpm . The temperature within the extruder was at 60°C in the first stage and 163°C in the remaining three stages . The extrudate was collected on a stainless steel plate or cooling belt.
The melt range reported in the examples is the range over which the melt processed blend first began to soften to the temperature at which the melt was fully liquified . The softening points reported in the examples were measured according to ASTM Method E28 "Test Method for Softening Point by Ring-and-Ball Apparatus" (American Society for Testing and Materials, Philadelphia, Pennsylvania, 1982) . The melt viscosity was a dynamic viscosity as measured by Bohlin Rheometer, model VOR, available from Bohlin Reologi, I nc. , Cranbury, New Jersey .
Bonds for shear testing were prepared by remelting the adhesive to a temperature above its melt range, and applying the melt between coated cereal box stock bonded coated side to uncoated side to simulate a flap closure of a cereal box . The adhesive was applied at the rate of approximately 0.2 grams per square inch .
The shear testing for Examples 1-14 was performed in accordance with TAPPI Method T 517 om-85 "Dynamic Strength of Flexible Barrier Material Seals" and TAPPI Useful Method 556 "Static Load Strength of Flexible Barrier Material Seals". The Dynamic Shear value reported below is the average load needed to cause failure and the Static Load Shear value reported below is the time until failure of a one square inch bond tested with a load of 300 grams. The peel and shear testing for Examples 23-30 was performed in accordance with Modified TAPPI Methods T8145su-71 from "Testing of Adhesives, TAPPI Monograph series No. 35 (R.G. Meese, ed., Mack Printing Co., Easton, Pennsylvania, 1974).
The following identifies the materials listed in the formulations set forth in the examples.
Dextrin 230: a pyrodextrin available from A.E. Staley Mfg. Co., Decatur, Illinois, as STADEX® 230.
Dextrin 94: a pyrodextrin available from A.E. Staley Mfg. Co., Decatur, Illinois, as STADEX® 94.
Acid-modified Starch: an acid depolymerized
® starch available from A.E. Staley Mfg. Co. as KOLDEX
60.
Maltodextrin 10: a 10 D.E. maltodextrin available from A.E. Staley Mfg. Co. as STAR-DRI® 10.
Maltodextrin 1: a 1 D.E. maltodextrin available from A.E. Staley Mfg. Co. as STAR-DRI® 1.
Corn Syrup Solids 24: a low conversion corn syrup solids having a D.E. of 24 available from A.E. Staley Mfg. Co. as STAR-DRI 24R
Corn Syrup Solids 35: a low conversion corn syrup solids having a D.E. of 35 available from A.E. Staley Mfg. Co. as STAR-DRI 35R
Corn Syrup Solids 42: a low conversion corn syrup solids having a D.E. of 42 available from A.E. Staley Mfg. Co. as STAR-DRI 42C
Methyl Glucoside: alpha-methyl glucoside available from Grain Processing Corporation, Muscatine, Iowa, as STA-MEG® 104.
Dextrose: dextrose monohydrate available from A.E. Staley Mfg. Co. as STALEYDEX® 333.
Paraffin Wax: a paraffin wax having a melt range of from 48°C to 68°C, available from Boyle-Midway, Inc., N.Y., N.Y.
C-4040 Wax: a saturated straight chain hydrocarbon polymer available from Petrolite Corporation,
® Tulsa, Oklahoma, as PETROLITE C-4040 crystalline polymer.
C-5500 Wax: an oxidized hydrocarbon available from Petrolite Corporation as PETROLITE® C-5500.
EVA 1 : an ethylene/vinyl acetate copolymer
® available from DuPont, Wilmington, Delaware, as ELVAX
205W.
EVA 2: an ethylene/vinyl acetate copolymer
® available from DuPont, Wilmington, Delaware, as ELVAX
210.
EBAC: an ethylene/n-butyl acrylate copolymer available from Quantum Chemical Corp . , Cincinnati, Ohio, as EA 89822.
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 88.8 Ibs./sq. in, at 100°F/85% r.h./24 hrs. 74.4 Ibs./sq. in,
Static Load Shear: at 100°F/85% r.h./300 gm. wt. Failed at 97 hrs.
Viscosity: at 135°C: at 150°C: 21,100 cps
Melt Range: 160°-163°C
Softening Point: 155°C
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 101.6 Ibs./sq. in. at 100°F/85% r.h./24 hrs.: 44.1 Ibs./sq. in.
Static Load Shear: at 100°F/85% r.h./300 gm. wt. : Failed at 54 hrs.
Viscosity: at 135°C: 39,200 cps at 150°C: 1,470 cps
Melt Range: 115°-123°C
Softening Point: 126.5°C
EXAMPLE 3
Formulation :
Parts
Ingredient by Weight Dextrin 20
Methyl Glucoside 50 Dextrose 15 C4040 Wax 5 C5500 Wax 10
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 99.3 Ibs./sq. in, at 100°F/85% r.h./24 hrs. 49.3 Ibs./sq. in,
Static Load Shear: at 100°F/85% r.h./300 gm. wt. Failed between 3 days and 5 days
Viscosity: at 135°C: 2,240 cps at 150°C: 1,120 cps
Melt Range: 116-122°C
Softening Point: 135.5°C
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 92.8 Ibs./sq. in, at 100°F/85% r.h./24 hrs. 0 Ibs./sq. in.
Static Load Shear: at 100°F/85% r.h./300 gm. wt. : <2 hrs. to failure
Viscosity: at 135°C: 17,800 cps at 150°C: 538 cps
Melt Range: 109°-119°C
Softening Point: 130°C
EXAMPLE 5
Formulation:
Parts
Ingredient by Weight Dextrin 25
Methyl Glucoside 50 Dextrose 25
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 79.5 Ibs./sq. in, at 100°F/85% r.h./24 hrs.: 0 Ibs./sq. in.
Static Load Shear: at 100°F/85% r.h./300 gm. wt. : <1 hr. to failure
Viscosity: at 135°C: 8,980 cps at 150°C: 670 cps
Melt Range: 117°-126°C
Softening Point: 134°C
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 81.2 Ibs./sq. in. at 100°F/85% r.h./24 hrs. 44.2 Ibs./sq. in.
Static Load Shear: at 100°F/85% r.h./300 gm. wt. : >10 days with no failure
Viscosity: at 121°C 12,800 cps at 135°C 7,590 cps at 150°C
Melt Range: 108°-129°C
Softening Point: 103.5°C
EXAMPLE 7
Formulation:
Parts
Inqredient by Weight Methyl Glucoside 72.2 Maltodextrin 10 27.8
Properties: Dynamic Shear: at 72°F/50% r.h./24 hrs.; 83.1 Ibs./sq. in, at 100°F/85% r.h./24 hrs, 88.3 Ibs./sq. in,
Static Load Shear: at 100°F/85% r.h./300 gm. wt. Failed at 20 hrs,
Viscosity: at 135°C: at 150°C: 1,230,000 cps
at 163°C: 2,960 cps
Melt Range: 147°-154°C
Softening Point: 145°C
EXAMPLE 8
Formulation:
Parts ngredient by Weight Methyl Glucoside 70.05 Acid-Modified Starch 23.70 Paraffin Wax 6.25
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 88.6 Ibs./sq. in, at 100°F/85% r.h./24 hrs. 82.3 Ibs./sq. in.
Static Load Shear: at 100°F/85% r.h./300 gm. wt. : >2 months with no failure
Viscosity: at 135°C: at 150°C: 16,500 cps
Melt Range: 149°-155°C
Softening Point: 155°C
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 85.0 Ibs./sq. in, at 100°F/85% r.h./24 hrs. 75.2 Ibs./sq. in,
Static Load Shear: at 100°F/85% r.h./300 gm. wt. >2 months with no failure
Viscosity: at 135°C at 150°C 150,000 cps at 163°C 5,260 cps
Melt Range: 149°-152°C
Softening Point: 156°C
EXAMPLE 10
Formulation :
Parts
Ingredient by Weight Methyl Glucoside 66.7 Acid-Modified Starch 33.3
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 90.9 Ibs./sq. in. at 100°F/85% r.h./24 hrs.: 81.5 Ibs./sq. in.
Static Load Shear: at 100°F/85% r.h./300 gm. wt. : >10 days with no failure
Viscosity: at 135°C 150,000 cps at 150°C 86,000 cps at 163°C 25,000 cps
Melt Range: 142°-152°C
Softening Point: 154.5°C
EXAMPLE 11
Formulation:
Parts
Ingredient by Weight Methyl Glucoside 50 Acid-Modified Starch 25 EBAC 25
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 99.6 Ibs./sq. in, at 100°F/85% r.h./24 hrs.: 83.4 Ibs./sq. in,
Static Load Shear: at 100°F/85% r.h./300 gm. wt. >10 days with no failure
Viscosity: at 135°C 3,590,000 cps at 150°C cps at 163°C 76,300 cps
Melt Range: 148°-155°C
Softening Point: 155°C
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 86.8 Ibs./sq. in. at 100°F/85% r.h./24 hrs.: 79.5 Ibs./sq. in.
Static Load Shear: at 100°F/85% r.h./300 gm. wt. : >10 days with no failure
Viscosity: at 135°C: at 150°C: 15,100 cps
Melt Range: 140°-150°C
Softening Point: 138.5°C
EXAMPLE 13
Formulation:
Parts
Ingredient by Weight Methyl Glucoside 55.6 Acid-Modified Starch 27.8 EVA 2 16.6
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: 97.6 Ibs./sq. in, at 100°F/85% r.h./24 hrs.: 83.3 Ibs./sq. in.
Static Load Shear: at 100°F/85% r.h./300 gm. wt. >10 days with no failure
Viscosity: at 135°C at 150°C 47,300 cps at 163°C 31,500 cps
Melt Range: 140°-150°C
Softening Point: 151°C
Properties:
Dynamic Shear: at 72°F/50% r.h./24 hrs.: at 100°F/85% r.h./24 hrs. Failed before 24 hrs.
Static Load Shear: at 100°F/85% r.h./300 gm. wt. : Failed at <l/2 hr.
Viscosity: at 135°C: 45,200 cps at 150°C: Foams
Melt Range: 105°-116°C
Softening Point: 88.5°C
EXAMPLE 17
Formulation:
Parts
Ingredient by Weight Dextrin 94 50 Dextrose 25 Sucrose 25
Percent Dynamic Shear Retained on Conditioning: 99.47
Peel : 66°C
Shear: >82°C
Softening Point: 95°C
Viscosity: at 149°C: 875 cps at 143°C: 1 ,238 cps at 138°C: 6,550 cps at 133°C: offscale
Percent Dynamic Shear Retained on Conditioning: 91 .78
Peel : 63°C
Shear: >82°C
Softening Point: 151 °C
Viscosity: at 149°C 2,375 cps at 143°C 3,250 cps at 138°C 6,213 cps at 133°C offscale
EXAMPLE 25
Formulation:
Parts
Ingredient by Weight Methyl Glucoside 50 Corn Syrup Solids 35 50
Properties
Dynamic Shear: at 72°F/50% r.h. First replicate: 27.23 Ibs./sq. in, Second replicate: 37.91 Ibs./sq. in,
Percent Dynamic Shear Retained on Conditioning: 78.53
Peel: 60° C
Shear: >82°C
Softening Point: 147°C
Viscosity: at 149°C 1,288 cps at 143°C 1,963 cps at 138°C off scale at 133°C off scale
Dynamic Shear: at 72°F/50% r.h. First replicate: 38.04 Ibs./sq. in. Second replicate: 40.67 Ibs./sq. in.
Percent Dynamic Shear Retained on Conditioning: 94.89
Peel: 41°C
Shear: >62°C
Softening Point: 107°C
Viscosity: at 149°C 8,638 cps at 143°C 127,500 cps at 138°C off scale at 133°C off scale
Percent Dynamic Shear Retained on Conditioning: 62.76
Peel : 77°C
Shear: >82°C
Softening Point: 103°C
Viscosity: at 149°C: 650 cps at 143°C: 900 cps at 138°C: 1 ,638 cps at 133°C: off scale
Percent Dynamic Shear Retained on Conditioning : 102.51
Peel : 57°C
Shear: >82°C
Softening Point: 79°C
Viscosity: at 149°C: 1 ,400 cps at 143°C: 2, 125 cps at 138°C: 5,625 cps at 133°C: off scale
Percent Dynamic Shear Retained on Conditioning : 86.37
Peel : 38°C
Shear: >82°C
Softening Point: 77°C
Viscosity: at 149°C 625 cps at 143°C 800 cps at 138°C 1 ,375 cps at 133°C 147,000 cps
EXAMPLE 30
Formulation:
Parts
Ingredient by Weight Methyl Glucoside 50 Corn Syrup Solids 24 35 Fructose 15
Properties
Dynamic Shear: at 72°F/50% r.h. First replicate: 49.82 Ibs./sq. in, Second replicate: 92.75 Ibs./sq. in,
Percent Dynamic Shear Retained on Conditioning: 65.48
Peel: 52°C
Shear: >82°C
Softening Point: 89°C
Viscosity: at 149°C 775 cps at 143°C 963 cps at 138°C 1,250 cps at 133°C 2,525 cps
EXAMPLES 31-42
A series of mixtures were prepared and melt processed substantially as described above. The ingredients and properties are set forth below.
Claims
What is claimed is:
1 . A composition useful as a thermoplastic material or component thereof comprising a melt processed blend of:
(a) a major amount of a meltable saccharide selected from the group consisting of a mono-saccharide, a di-saccharide, a derivative of a mono-saccharide, a derivative of a di-saccharide, and mixtures of more than one of such meltable saccharides, and
(b) a minor amount of a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches, cold-water soluble dextrins, and maltodextrins, low conversion corn syrup solids, and mixtures of more than one of such polysaccharides, wherein : (i) said major amount of meltable saccharide is sufficient to provide a flowable melt of said composition, and
(ii) the degree of polymerization and said minor amount of said polysaccharide is sufficient to tackify said melt, but is insufficient to prevent said melt from flowing.
2. A composition of Claim 1 wherein said meltable saccharide is comprised of a lower alkyl glycoside.
3. A composition of Claim 1 wherein said meltable saccharide is methyl glucoside.
4. A composition of Claim 1 wherein said pre-gelatinized converted starches have a weight average molecular weight of from about 5,000 to about 15,000 g/mole, said cold-water soluble dextrins have a weight average molecular weight of from about 5,000 to about 15,000 g/mole, said maltodextrins have a weight average molecular weight of from about 4,000 g/mole to about 250,000 g/mole, and said corn syrup solids have a D. E. of from about 20 to about 45.
5. A composition of Claim 1 wherein said minor amount of said polysaccharide is from about 15% to about 35% by weight of said composition .
6. A composition of Claim 1 wherein said composition forms a melt having a dynamic viscosity of not more than about 50,000 cps when measured at 135°C.
7. A composition of Claim 1 wherein said composition forms a melt having a dynamic viscosity of not more than about 10,000 cps when measured at 135°C .
8. A composition of Claim 1 wherein said composition has a moisture content of no more than about 15% by weight.
9. A composition of Claim 1 wherein said composition has a moisture content of less than 5% by weight.
10. A composition of Claim 1 wherein said composition is a homogeneous melt-processed blend of said meltable saccharide and said polysaccharide.
11 . A composition of Claim 1 further comprising a thermoplastic polymer having a melting point within the range of about 100°C to about 200°C in an amount less than about 50% by weight of said composition .
12. A method of adhering a cellulosic material to another substrate comprising interposing a melt of a blend composition between a cellulosic material and a substrate such that the cellulosic material and substrate are in contact with said melt and cooling said melt while in contact with said cellulosic material and said substrate, wherein said blend composition comprises :
(a) a major amount of a meltable saccharide selected from the group consisting of a mono-saccharide, a di-saccharide, a derivative of a mono-saccharide, a derivative of a di-saccharide, and mixtures of more than one of such meltable saccharides, and
(b) a minor amount of a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches, cold-water soluble dextrins, and maltodextrins, low conversion corn syrup solids, and mixtures of more than one of such polysaccharides, wherein :
(i) said major amount of meltable saccharide is sufficient to provide a flowable melt of said composition, and
(ii) the degree of polymerization and said minor amount of said polysaccharide is sufficient to tackify said melt, but is insufficient to prevent said melt from flowing.
13. A method of manufactu ring a shaped article comprising melting a blend composition , shaping said melt into the form of an article, and cooling said melt while in the shape of said article, wherein said blend composition comprises :
(a) a major amount of a meltable saccharide selected from the group consisting of a mono-saccha ride, a di-saccharide, a derivative of a mono-saccharide, a derivative of a di-saccharide, and mixtu res of more than one of such meltable saccharides , and
(b) a minor amount of a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches , cold-water soluble dextrins, and maltodextrins , low conversion corn syrup solids, and mixtures of more than one of such polysaccharides , wherein :
(i) said major amount of meltable saccharide is sufficient to provide a flowable melt of said composition , and (ii) the degree of polymerization and said minor amount of said polysaccharide is sufficient to tackify said melt, but is insufficient to prevent said melt from flowing .
14. An article of manufactu re produced by the. method of Claim 13.
15. A composition useful as a hot melt adhesive or component thereof comprising a major amount of a lower al kyl glycoside, and a minor amount of a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches , cold-water soluble dextrins , and maltodextrins , and
mixtures of more than one of such members of said group, wherein :
(ϊ) said major amount of alkyl glycoside is sufficient to provide a flowable melt of said composition, and
(ii) the degree of polymerization and said minor amount of said polysaccharide is sufficient to tackify said melt, but is insufficient to prevent said melt from flowing .
16. A composition of Claim 15 wherein said lower alkyl glycoside is a lower alkyl glucoside.
17. A composition of Claim 15 wherein said lower alkyl glycoside is methyl glucoside.
18. A composition of Claim 15 wherein said pre-gelatinized converted starches have a weight average molecular weight of from about 5,000 to about 15,000 g/mole, said cold-water soluble dextrins have a weight average molecular weight of from about 5,000 to about 15,000 g/mole, and said maltodextrins have a weight average molecular weight of from about 4,000 g/mole to about 250,000 g/mole.
19. A composition of Claim 15 wherein said minor amount of said polysaccharide is from about 15% to about 35% by weight of said composition .
20. A composition of Claim 15 wherein said composition forms a melt having a dynamic viscosity of not more than about 50,000 cps when measured at 135°C.
21 . A composition of Claim 15 wherein said composition forms a melt having a dynamic viscosity of not more than about 10,000 cps when measured at 135°C .
22. A composition of Claim 15 wherein said composition has a moisture content of no more than about 15% by weight.
23. A composition of Claim 15 wherein said composition has a moisture content of less than 5% by weight.
24. A composition of Claim 15 wherein said composition is a homogeneous melt-processed blend of said lower alkyl glycoside and said polysaccharide.
25. A composition of Claim 15 further comprising a thermoplastic polymer having a melting point within the range of about 100°C to about 200°C in an amount less than about 50% by weight of said composition .
26. A method of adhering a cellulosic material to another substrate comprising interposing a melt of the composition of Claim 15 between a cellulosic material and a substrate such that the cellulosic material and substrate are in contact with said melt and cooling said melt while in contact with said cellulosic material and said substrate.
27. A method of manufacturing a shaped article comprising melting a composition of Claim 15, shaping said melt into the form of an article, and cooling said melt while in the shape of said article.
28. An article of manufacture produced by the method of Claim 27.
29. A composition useful as a hot melt adhesive or component thereof comprising a lower alkyl glycoside, dextrose, and a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches, cold-water soluble dextrins, and maltodextrins, and mixtures of more than one of such members of said group, wherein :
(i) the amounts of dextrose and lower alkyl glycoside are sufficient to provide a flowable melt of said composition,
(ii) the amount of said lower alkyl glycoside is sufficient in relation to the amount of dextrose in said composition to impart to said composition resistance to adhesive failure when used as a hot melt adhesive under conditions of elevated humidity, and
(iii) the degree of polymerization and the amount of said polysaccharide are sufficient to tackify said melt, but is insufficient to prevent said melt from flowing.
30. A composition of Claim 29 wherein said lower alkyl glycoside is a lower alkyl glucoside.
31 . A composition of Claim 29 wherein said lower alkyl glycoside is methyl glucoside.
32. A composition of Claim 29 wherein said pre-gelatinized converted starches have a weight average molecular weight of from about 5,000 to about 15,000 g/mole, said cold-water soluble dextrins have a weight average molecular weight of from about 5,000 to about 15,000 g/mole, and said maltodextrins have a weight average molecular weight of from about 4,000 g/mole to about 250,000 g/mole.
33. A composition of Claim 29 wherein said minor amount of said polysaccharide is from about 15% to about 35% by weight of said composition .
34. A composition of Claim 29 wherein said composition forms a melt having a dynamic viscosity of not more than about 50,000 cps when measured at 135°C .
35. A composition of Claim 29 wherein said composition forms a melt having a dynamic viscosity of not more than about 10,000 cps when measured at 135°C .
36. A composition of Claim 29 wherein the weight ratio of the amount of said lower alkyl glycoside to the amount of said dextrose is from about 1 : 1 to about 5: 1 .
37. A composition of Claim 29 wherein said composition has a moisture content of no more than about 15% by weight.
38. A composition of Claim 29 wherein said composition has a moisture content of less than 5% by weight.
39. A composition of Claim 29 wherein said composition is a homogeneous melt-processed blend of said lower alkyl glycoside, said dextrose and said polysaccharide.
40. A composition of Claim 29 further comprising a thermoplastic polymer having a melting point within the range of about 100°C to about 200°C in an amount less than about 50% by weight of said composition .
41 . A method of adhering a cellulosic material to another substrate comprising interposing a melt of the composition of Claim 29 between a cellulosic material and a substrate such that the cellulosic material and substrate are in contact with said melt and cooling said melt while in contact with said cellulosic material and said substrate.
42. A method of manufacturing a shaped article comprising melting a composition of Claim 29, shaping said melt into the form of an article, and cooling said melt while in the shape of said article.
43. An article of manufacture produced by the method of Claim 29.
44. A composition useful as a hot melt adhesive or component thereof comprising methyl glucoside, dextrose, and a polysaccharide derived from starch selected from the group consisting of pre-gelatinized converted starches, cold-water soluble dextrins, and maltodextrins, and mixtures of more than one of such members of said group, wherein :
(i) the amounts of dextrose and methyl glucoside total a major amount by weight of said composition and are sufficient to provide a flowable melt of said composition,
(ii) the weight ratio of methyl glucoside to dextrose in said composition ranges from about 1 : 1 to about 5: 1 , provided that the amount of said methyl glucoside is sufficient in relation to the amount of dextrose in said composition to impart to said composition resistance to adhesive failure when used as a hot melt adhesive under conditions of elevated humidity, and
(iii) said polysaccharide is present in an amount of from about 15% to about 35% by weight of the composition and the degree of polymerization and the amount of said polysaccharide are sufficient to tackify said melt, but are sufficient to provide said melt with a dynamic viscosity of more than about 10,000 cps when measured at 135°C .
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US71478991A | 1991-06-13 | 1991-06-13 | |
US714789 | 1991-06-13 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0543983A1 EP0543983A1 (en) | 1993-06-02 |
EP0543983A4 true EP0543983A4 (en) | 1994-02-09 |
Family
ID=24871462
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP92913373A Withdrawn EP0543983A1 (en) | 1991-06-13 | 1992-06-10 | Hot melt adhesive composition and method |
Country Status (7)
Country | Link |
---|---|
EP (1) | EP0543983A1 (en) |
JP (1) | JPH06500821A (en) |
AU (1) | AU2227092A (en) |
CA (1) | CA2089175A1 (en) |
MX (1) | MX9202820A (en) |
PL (1) | PL298230A1 (en) |
WO (1) | WO1992022606A1 (en) |
Families Citing this family (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE4125122C2 (en) * | 1991-07-30 | 1994-06-23 | Henkel Kgaa | Starch ether-based glue stick |
US5360845A (en) * | 1992-12-23 | 1994-11-01 | National Starch And Chemical Investment Holding Corporation | Starch ester based hot melt adhesive |
US5434201A (en) * | 1994-07-29 | 1995-07-18 | National Starch And Chemical Investment Holding Corporation | Process for production of starch based hot melt adhesives |
US5523335A (en) * | 1994-10-17 | 1996-06-04 | Henkel Corporation | Printing inks and related laminates and processes |
ES2112192B1 (en) * | 1995-11-29 | 1999-09-16 | Univ Pais Vasco | BLENDS OF STARCH AND COPOLYMER OF ETHYLENE AND VINYL ACETATE AND THERMOFUSIBLE ADHESIVES THAT CONTAIN THEM. |
SE9602226D0 (en) | 1996-06-05 | 1996-06-05 | Astra Ab | Biocompatible glue |
US6846502B1 (en) * | 1996-06-26 | 2005-01-25 | National Starch & Chemical Investment Holding Corporation | Edible hot melt composition |
NL1004379C2 (en) * | 1996-10-29 | 1998-05-08 | Borculo Cooep Weiprod | Use of sugar amines and sugar amides as an adhesive, as well as new sugar amines and sugar amides. |
FI113876B (en) | 2002-02-15 | 2004-06-30 | Valtion Teknillinen | New starch-based adhesives |
US7070822B1 (en) | 2002-12-20 | 2006-07-04 | National Starch And Chemical Investment Holding Corporation | Powdered adhesive for foods |
DE10344126A1 (en) * | 2003-09-24 | 2005-04-21 | Henkel Kgaa | Water soluble hot melt adhesive |
CN101280162B (en) * | 2008-05-29 | 2010-06-02 | 同济大学 | Preparation of low-cost hot-melt adhesive |
FR2961822B1 (en) * | 2010-06-24 | 2014-02-21 | Raphael Georges Duval | PROCESS FOR THE PREPARATION OF ADHESIVES FROM AT LEAST ONE CETOSE AND AT LEAST ONE POLYSACCHARIDE OF DP> 2, ADHESIVE COMPOSITIONS AND USES THEREOF |
WO2013096438A1 (en) * | 2011-12-19 | 2013-06-27 | Tate And Lyle Ingredients Americas Llc | Formulation for the prevention of delamination in starch-based adhesives |
CN104015324A (en) * | 2014-05-27 | 2014-09-03 | 东莞市华立实业股份有限公司 | Preparation technology for edge-sealing strip subjected to co-extrusion molding |
CN114426761B (en) * | 2020-10-29 | 2023-09-08 | 财团法人工业技术研究院 | Biodegradable polyester material and method for producing same |
US20240026583A1 (en) | 2020-12-08 | 2024-01-25 | Wacker Chemie Ag | Textile sheet material |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
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USH603H (en) * | 1987-12-04 | 1989-03-07 | A. E. Staley Manufacturing Company | Methods of making and using adhesive resins and glue mixes |
-
1992
- 1992-06-10 WO PCT/US1992/004876 patent/WO1992022606A1/en not_active Application Discontinuation
- 1992-06-10 AU AU22270/92A patent/AU2227092A/en not_active Abandoned
- 1992-06-10 JP JP5500995A patent/JPH06500821A/en active Pending
- 1992-06-10 PL PL29823092A patent/PL298230A1/en unknown
- 1992-06-10 CA CA002089175A patent/CA2089175A1/en not_active Abandoned
- 1992-06-10 EP EP92913373A patent/EP0543983A1/en not_active Withdrawn
- 1992-06-12 MX MX9202820A patent/MX9202820A/en unknown
Non-Patent Citations (2)
Title |
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No further relevant documents disclosed * |
See also references of WO9222606A1 * |
Also Published As
Publication number | Publication date |
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PL298230A1 (en) | 1994-02-07 |
WO1992022606A1 (en) | 1992-12-23 |
EP0543983A1 (en) | 1993-06-02 |
MX9202820A (en) | 1992-12-01 |
AU2227092A (en) | 1993-01-12 |
JPH06500821A (en) | 1994-01-27 |
CA2089175A1 (en) | 1992-12-14 |
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