Solvent free aqueous polyurethane dispersions and adhesive films therefrom for stretch fabrics

Abstract

Novel aqueous polyurethane dispersions and shaped articles formed therefrom are provided. The aqueous polyurethane dispersions are provided in solvent-free systems of a prepolymer comprising at least one polyether, polyester, or polycarbonate polyol, a mixture of MDI isomers, and a diol. The shaped articles from such dispersions can be heat-activated for bonding, lamination, and adhesion of substrates, including stretch fabrics.

1 . A prepolymer for use in an aqueous polyurethane dispersion comprising: 
 a) at least one polyether, polyester or polycarbonate polyol, wherein said polyether, polyester, or polycarbonate polyol has a number average molecular weight of about 600 to about 3,500;    b) a mixture of 4,4′and 2,4′-methylene bis(phenyl isocyanate)(MDI) isomers, wherein the ratio of 4,4′-MDI to 2,4′-MDI isomers ranges from about 65:35 to about 35;65; and    c) at least one diol compound comprising: (i) hydroxyl groups capable of reacting with the mixture of MDI isomers of components b), and (ii) at least one carboxylic acid group capable of forming a salt upon neutralization, wherein said at least one carboxylic acid group is incapable of reacting with the mixture of MDI isomers of component b),    wherein the prepolymer is substantially solvent-free.    
     
     
         2 . The prepolymer of  claim 1 , wherein the at least one polyether, polyester, or polycarbonate of component a) is a poly(tetramethylene ether) glycol having a number average molecular weight of about 1400 to about 2400.  
     
     
         3 . The prepolymer of  claim 1 , wherein the ratio of 4,4′-MDI to 2,4′-MDI isomers ranges from about 55:45 to about 45:55.  
     
     
         4 . The prepolymer of  claim 1 , wherein the at least one diol compound is selected from the group consisting of 2,2-dimethylopropionic acid (DMPA), 2,2-dimethlobutanoic acid, and 2,2-dimethylovaleric acid.  
     
     
         5 . The prepolymer of  claim 2 , wherein the ratio of 4,4′-MDI to 2,4′-MDI isomers ranges from about 55:45 to about 45:55, and the at least one diol compound is 2,2-dimethylopropionic acid (CMPD).  
     
     
         6 . The prepolymer of  claim 1 , wherein the component a) is present in a weight percentage ranged from about 34% to about 89%, based on the total weight of the prepolymer; component b) is present in a weight percentage ranging from about 59% to about 10%, based on the total weight of the prepolymer; and component c) is present in a weight percentage ranging from about 7.0% to about 1.0%, based on the total weight of the prepolymer.  
     
     
         7 . The prepolymer of  claim 1 , having a bulk viscosity from about 500 to about 6,000 poises, measured by the falling ball method at 40° C.  
     
     
         8 . The prepolymer of  claim 7 , having a bulk viscosity from about 500 to about 4,500 poises, measured by the falling ball method at 40° C.  
     
     
         9 . The prepolymer of  claim 1 , further comprising at least one additional component selected from the group consisting of anti-oxidants, UV stabilizers, colorants, pigments, crosslinking agents, phase change materials, antimicrobials, minerals, microencapsulated well-being additives, nanoparticles, calcium carbonate, flame retardants, antitack additives, chlorine resistant additives, dye-assist agents, adhesion promoters, anti-static agents, anti-cratering agents, anti-crawling agents, optical brighteners, coalescing agents, electroconductive additives, luminescent additives, flow and leveling agents, freeze-thaw stabilizers, lubricants, organic and inorganic fillers, preservatives, texturing agents, therochromic additives, insect repellants, and wetting agents.  
     
     
         10 . The prepolymer of  claim 1 , wherein the at least one polyether, polyester, or polycarbonate polyol of component a) has two glycol ends or three glycol ends.  
     
     
         11 . The prepolymer of  claim 1 , wherein the aqueous polyurethane dispersion is a polyurethane urea.  
     
     
         12 . A process for making a prepolymer for use in an aqueous polyurethane dispersion, wherein the prepolymer comprises: 
 a. at least one polyether, polyester, or polycarbonate polyol, wherein said polyether, polyester, or polycarbonate polyol has a number average molecular weight of about 600 to about 3,500;    b. a mixture of 4,4′and 2,4′-methylene bis(phenyl isocyanate) (MDI) isomers, wherein the ratio of 4,4′-MDI to 2,4′-MDI isomers ranges from about 65:35 to about 35:65; and    c. at least one diol compound comprising: (i) hydroxyl groups capable of reacting with the mixture of MDI isomers of component b) and (ii) at least one carboxylic acid group capable of forming a salt upon neutralization, wherein said at least one carboxylic acid group is incapable of reacting with the mixture of MDI isomers of component b);    and the process comprises combining components a), b) and c) in a substantially solvent-free system.    
     
     
         13 . The process of  claim 12 , wherein components a), b), and c) are mixed and allowed to react at temperatures ranging from about 50° C. to about 100° C.  
     
     
         14 . The process of  claim 12 , k wherein components a), b), and c) are combined together in one step.  
     
     
         15 . The process of  claim 12 , wherein components a) and b) are reacted in a first step, followed by combination with component c).  
     
     
         16 . The process of  claim 12  further comprising a catalyst.  
     
     
         17 . An aqueous polyurethane dispersion, comprising: 
 a prepolymer, which comprises:    a) at least one polyether, polyester, or polycarbonate polyol, wherein said polyether, polyester, or polycarbonate polyol has a number average molecular weight of about 600 to about 3,500;    b) a mixture of 4,4′and 2,4′-methylene bis(phenyl isocyanate) (MDI) isomers, wherein the ratio of 4,4′-MDI to 2,4′-MDI isomers ranges from about 65:35 to about 35:65; and    c) at least one diol compound comprising (i) hydroxyl groups capable of reacting with the mixture of MDI isomers of component b) and (ii) at least one carboxylic acid group capable of forming a salt upon neutralization, wherein said at least one carboxylic acid group is incapable of reacting with the mixture of MDI isomers of component b); wherein the aqueous polyurethane dispersion is a substantially solvent-free system that further comprises;    d) at least one neutralizing agent to form an ionic salt with the at least one diol compound; and    e) at least one monfunctional dialkyl amine compound as a blocking agent for isocyanate groups.    
     
     
         18 . The aqueous polyurethane dispersion of  claim 17 , further comprising at least one surface active agent and at least one antifoam agent.  
     
     
         19 . The aqueous polyurethane dispersion of  claim 18 , further comprising at least one rheological modifier.  
     
     
         20 . The aqueous polyurethane dispersion of  claim 19 , further comprising: 
 f) at least one diamine chain extension component, and    g) at least one polymeric component having a molecular weight of greater than about 500, with at least three or more primary and/or secondary amino groups per mole of the polymer.    
     
     
         21 . The aqueous polyurethane dispersion of  claim 17 , wherein the at least one neutralizing agent is selected from the group consisting of tertiary amines and alkali metal hydroxides; and the at least one blocking agent is selected from the group consisting of N,N-diethylamine, N-ethyl-N-propylamine, N,N-diisopropylamine, N-tert-butyl-N-methyamine, N-tert-butyl-N-benzylamine, N,N-dicyclohexylexylamine, N-ethyl-N-isopropylamine, N-tert-butyl-N-isopropylamine, N-isopropyl-N-cyclohexylamine, N-ethyle-N-cycloheylamine, N,N-diethanolamine, and 2,2,6,6-tetramethylpiperidine.  
     
     
         22 . The aqueous polyurethane dispersion of  claim 18 , wherein the at least one surface active agent is selected from the group consisting of sodium dodecyl sulfate, sodium dodecylbenzenesulfonate, ethoxylated nonylphenols, and lauryl pyridinium bromide.  
     
     
         23 . The aqueous polyurethane dispersion of  claim 19 , wherein the at least one rheological modifier is selected from the group consisting of hydrophobically-modified ethoxylate urethanes (HEUR), hydrophobically-modified alkali swellable emulsions (HASE), and hydrophobically-modified hydroxyl-ethyl cellulose (HMHEC).  
     
     
         24 . The aqueous polyurethane dispersion of  claim 20 , wherein the at least one diamine chain extension component is selected from the group consisting of 1,2-ethylenediamine, 1,4-butanediamine, 1,6-hexamethylenediamine, 1,12-dodecanediamine, 1,2-propanediamine, 2-methyl-1,5-pentanediamine, 1,2-cyclohexanediamine, 1,4-cyclohexanediamine, 4,4′-methylene-bis(cyclohexlamine), isophorone diamine, 2,2-dimethyl-1,3-propanediamine, and meta-tetramethylxylenediamine; and the at least one polymeric component having a molecular weight of greater than about 500 is selected from the group consisting of polyethyleneimine dendrimers, poly(vinylamine) dendrimers, poly(allylamine) dendrimers, and poly(amidoamine) dendrimers.  
     
     
         25 . The aqueous polyurethane dispersion of  claim 17 , wherein the at least one polyether, polyester, or polycarbonate polyol of component a) is a poly(tetramethylene ether) glycol having a number average molecular weight of about 1,700 to about 2,100, the ratio of 4,4′-MDI to 2,4′-MDI isomers ranges from about 55:45 to about 45:55, and the at least one diol compound is 2,2-dimethylopropionic acid (DMPA).  
     
     
         26 . The aqueous polyurethane dispersion of  claim 20 , further comprising at least one additional component selected from the group consisting of anti-oxidants, UV stabilizers, colorants, pigments, crosslinking agents, phase change materials, antimicrobials, minerals, microencapsulated well-being additives, nanoparticles, calcium carbonate, flame retardants, antitack additives, chlorine degradation resistant additives, dye-assist agents, wetting and leveling agents, adhesion promoters, anti-static agents, anti-cratering agents, anti-crawling agents, optical brighteners, coalescing agents, electroconductive additives, luminescent additives, flow and leveling agents, freeze-thaw stabilizers, lubricants, organic and inorganic fillers, preservatives, texturing agents, therochromic additives, insect repellants, and wetting agents.  
     
     
         27 . The aqueous polyurethane dispersion of  claim 20  wherein the bulk viscosity is from about 10 to about 100,000 centipoises as measured by the falling ball method at 40° C.  
     
     
         28 . The aqueous polyurethane dispersion of  claim 27  wherein the bulk viscosity is from about 500 to about 30,000 centipoises as measured by the falling ball method at 40° C.  
     
     
         29 . A process for making an aqueous polyurethane dispersion, wherein the aqueous polyurethane dispersion comprises: 
 a prepolymer which comprises:    a) at least one polyether, polyester, or polycarbonate polyol, wherein said polyether, polyester, or polycarbonate polyol has a number average molecular weight of about 600 to about 3,500;    b) a mixture of 4,4′-and 2,4′-methylene bis(phenyl isocyanate) (MDI) isomers, wherein the ratio of 4,4′-MDI to 2,4′-MDI isomers ranges from about 65:35 to about 35:65; and    c) at least one diol compound comprising (i) hydroxyl groups capable of reacting with the mixture of MDI isomers of component b) and (ii) at least one carboxylic acid group capable of forming a salt upon neutralization, wherein said at least one carboxylic acid group is incapable of reacting with the mixture of MDI isomers of component b); wherein the aqueous polyurethane dispersion is a substantially solvent-free system that further comprises;    d) at least one neutralizing agent to form an ionic salt with the at least one diol compound; and    e) at least one monfunctional dialkyl amine compound as a blocking agent for isocyanate groups;    and where the process comprises dispersing the prepolymer in an aqueous medium, wherein the at least one neutralizing agent is added to either the prepolymer or aqueous medium prior to dispersing the prepolymer in the aqueous medium, and the at least one blocking agent is added to the aqueous medium either during or after dispersing the prepolymer in the aqueous medium.    
     
     
         30 . The process according to  claim 29 , wherein the at least one blocking agent is added to the aqueous medium immediately after dispersing the prepolymer in the aqueous medium.  
     
     
         31 . The process according to  claim 30 , wherein the at least one neutralizing agent is added to the aqueous medium prior to dispersing the prepolymer in the aqueous medium.  
     
     
         32 . The process according to  claim 30 , wherein the at least one neutralizing agent is added to the prepolymer prior to dispersing the prepolymer in the aqueous medium.  
     
     
         33 - 68 . (canceled)  
     
     
         69 . A shaped article derived from the aqueous polyurethane dispersion of  claim 17 .  
     
     
         70 . The shaped article of  claim 69 , wherein the aqueous polyurethane dispersion is formed into a film or tape.  
     
     
         71 . The shaped article of  claim 69 , wherein the shaped article comprises a glove, condom, bead, fiber or a sheet of film.  
     
     
         72 . The shaped article of  claim 69 , wherein a surface of the shaped article is adapted to receive marking or to receive printing inks or dyes.  
     
     
         73 . The shaped article of  claim 69 , wherein a dye or pigment is incorporated into the aqueous polyurethane dispersion  
     
     
         74 . The shaped article of  claim 69 , wherein said article is shaped by molding.  
     
     
         75 . A garment comprising one or more of the shaped articles of  claim 69  applied or laminated or bonded to a fabric.  
     
     
         76 . The garment of  claim 75  wherein the garment is molded after the shaped article or shaped articles is/are laminated or bonded or applied to the fabric.  
     
     
         77 . A garment comprising one or more of the shaped articles of  claim 74  applied or laminated or bonded to a fabric.  
     
     
         78 . A garment comprising one or more of the shaped articles of  claim 69  bonded or adhered to a seam or a support area of a fabric forming said garment.  
     
     
         79 . A garment comprising one or more of the shaped articles of  claim 69  bonded or adhered to a fabric that has been pre-treated to increase hydroxyl functionality of said fabric with one or more substances selected from the group consisting of acids, plasmas and dyes.  
     
     
         80 . A garment comprising one or more of the shaped articles of  claim 74  bonded or adhered to a fabric that has been pretreated to increase hydroxyl functionality of said fabric with one or more substances selected from the group consisting of acids, plasmas and dyes.  
     
     
         81 . The shaped article of  claim 69 , wherein the aqueous polyurethane dispersion is coated onto a substrate to a thickness of from about 0.1 mil to about 250 mil.  
     
     
         82 . The shaped article of  claim 81 , wherein the aqueous polyurethane dispersion coating has a basis weight of about 2.5 g/m 2  to about 6.4 kg/m 2 .  
     
     
         83 . An intimate apparel item comprising one or more of the shaped articles of  claim 69  applied or laminated or bonded to a fabric.  
     
     
         84 . An intimate apparel item comprising one or more of the shaped articles of  claim 74  applied or laminated or bonded to a fabric.  
     
     
         85 . An intimate apparel item comprising the shaped article of  claim 81 .  
     
     
         86 . A brassiere incorporating a shaped article of  claim 69 .  
     
     
         87 . A brassiere incorporating a shaped article of  claim 74 .  
     
     
         88 . A brassiere comprising the shaped article of  claim 81.