Abstract:
A one step system for hoof repair material that cures upon exposure to light. Found is a urethane solution that contains polymerization initiators so that exposure to visible light induces the cure.

Description:
RELATED APPLICATIONS  
       [0001]     This application claims benefit to PCT/US2006/031620 and U.S. Provisional Application Ser. No. 60/707,885, filed Aug. 12, 2005, both of which are incorporated herein by reference in their entireties for all useful purposes. 
     
    
     BACKGROUND OF THE INVENTION  
       [0002]     The three U.S. patents that mention hoof material are U.S. Pat. Nos. 6,761,223; 6,505,686; and 6,497,292. All three deal with a two part system (A and B) for creating hoof protecting shoes that take the place of metal horse shoes. Part A contains a diisocyanate and Part B contains an alcohol. When mixed immediately before application of the dough on a hoof, these two chemicals react to create a urethane-based polymer.  
       SUMMARY OF THE INVENTION  
       [0003]     The present invention relates to a one-step system for hoof repair material that cures upon exposure to light. This one-step system provides for a liquid urethane solution that contains polymerization initiators so that exposure to visible light induces the cure.  
         [0004]     The invention also relates to a thickened urethane liquid solution that is light curable and has a viscosity about 500 to about 100,000 cps. The thickened urethane liquid solution also must be surface-active on the hoof. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0005]     The following formulation is preferable for applying to a hoof of an animal, especially a horse or cow:  
         [0006]     a liquid urethane, such as, but not limited to a urethane dimethacrylate (UDMA) or a urethane formed by reacting diisocyanate, preferably 2,2,4-trimethyl hexane diisocyanate or 3,3,5 hexane diisocyanate, with an alcohol or polyol. The liquid urethane is present in an amount of from 10 to about 100 weight %,  
         [0007]     and a visible light-absorbing initiator (photoinitiator) which absorbs light in the visible light region from about 350-600 nm. Any number of commercially sold photoinitiators are employable, including photo-polymerization initiators which have hitherto been used for dental compositions, such as α-diketone compounds, ketal compounds, anthraquinone-based compounds, thioxanthone-based compounds, benzoin alkyl ether-based compounds, acyl phosphine oxide-based compounds, and α-aminoketone-based compounds. Specific examples include camphorquinone, benzil, diacetyl, benzyl dimethyl ketal, benzyl diethyl ketal, benzyl di(2-methoxyethyl) ketal, 4,4′-dimethylbenzyl-dimethyl ketal, anthraquinone, 1-chloroanthraquinone, 2-chloroanthraquinone, 1,2-benzanthraquinone, 1-hydroxyanthraquinone, 1-methylanthraquinone, 2-ethylanthraquinone, 1-bromoanthraquinone, thioxanthone, 2-isopropylthioxanthone, 2-nitrothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, 2,4-diisopropylthioxanthone, 2-chloro-7-trifluoromethylthioxanthone, thioxanthone-10,10-dioxide, thioxanthone-10-oxide, benzion methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin isobutyl ether, benzophenone, bis(4-dimethylaminophenyl)ketone, 4,4′-bisdiethylaminobenzophenone, 2,4,6-trimethylbenzoyl diphenylphosphine oxide, 2,6-dimethylbenzoyl diphenylphosphine oxide, 2,6-dimethoxybenzoyl diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, and 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropan-1-one. The photo-polymerization initiators may be used either singly or in admixture of two or more thereof.  
         [0008]     Of these, benzyl dimethyl ketal (which absorbs light at about 420 nm), camphorquinone (CQ) (which absorbs light at about 470 nm), or 2,4,6-trimethylbenzoyl diphenylphosphine oxide (which absorbs light at about 350-400 nm) are particularly preferred. The initiator would preferably be in an amount of from about 0.01 to about 5 weight %.  
         [0009]     In addition, if desired, a photo-polymerization accelerator can be used in combination. For the photo-polymerization accelerator, an aromatic tertiary amine, an aliphatic tertiary amine, and the like are effective. Specific examples of the photo-polymerization accelerator that can be used include N,N-dimethyl-p-toluidine, N,N-diethyl-p-toluidine, N,N-dimethylaniline, N,N-bis(2-hydroxyethyl)-p-toluidine, N,N-dimethylaminoethyl methacrylate, triethanolamine, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, isoamyl 4-dimethylaminobenzoate, triethylamine, N-ethyidiethanolamine, and triethanolamine. As a matter of course, these photo-polymerization accelerators may be used either singly or in admixture of two or more thereof.  
         [0010]     The formulation may additionally contain a polymerizable monomer of a methacrylate or an acrylate containing at least one unsaturated double bond in a molecule thereof, such as, but not limited to, methyl (meth)acrylate (MMA), ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, glycidyl (meth)acrylate, 2-methoxyethyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, 2,2-bis[(meth)acryloxyphenyl]propane, 2,2-bis[4-(meth)acryloxydiethoxyphenyl]propane, 2,2-bis[4-(meth)acryloxypolyethoxyphenyl]propane, ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycoldi(meth)acrylate, butylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, trimethylolmethane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxy-1,3-di(meth)acryloxypropane, 1,2-dihydroxy-3-(meth)-acryloxypropane, and 2,2-bis[4-{2-hydroxy-3-(meth)-acryloxypropoxy}phenyl]propane, preferably in an amount of from about 3 to about 55 weight %. Acid group-free polymerizable monomers having a urethane bond in the molecule thereof may also be included, for example di-2-(meth)acryloxyethyl-2,2,4-trimethylhexamethylene dicarbamate (see U.S. Pat. No. 6,916,858, which is incorporated herein by reference in its entirety for all useful purposes), preferably in an amount of from about 3 to about 55 weight %.  
         [0011]     The formulation may additionally contain a viscosity thickening agent. A number of suitable viscosity thickening agents are commercially available, including but not limited to inorganic thickening agents such as dibenzyl sorbitol (DBS), finely divided or colloidal silicas, fumed silicas, and silicates, which includes montmorillonite clays and hydrophobically treated montmorillonites, e.g., bentonites, hectorites and colloidal magnesium silicates, and also including, but not limited to, organic thickening agents such as hydrogenated butylene/ethylene/styrene copolymer, polyethylene, oxidized polyethylene, polyamides, acrylic acid polymers, ethylene acrylate copolymers, and other organic polymeric gelling agents. Preferably, the thickening agent used is DBS. Thickening agents are preferably present in an amount up to about 5 weight %.  
         [0012]     The formulation may additionally contain bisphenol diglycidylmethacrylate (BisGMA). When used in this application, BisGMA thickens the viscosity of the polymer and imparts additional beneficial properties to the polymer, making the polymer hard, glassy, and tough. BisGMA is preferably present in an amount of from about 15 to about 75 weight %.  
         [0013]     The formulation may additionally contain polar molecules to generate bonding influence on the surface. The polar molecules change the polarity of the polymer on the hoof. A number of suitable polar molecules are commercially available, such as 2-hydroxypropyl methacrylate, 2-hydroxyethyl methacrylate, methacryloxyethyl phthalate, the addition product of 2-hydroxyethyl methacrylate and succinic anhydride, the addition product of 1,3-glycerol dimethacrylate and maleic anhydride, the addition product of 2-hydroxyethyl methacrylate and pyrromelletic anhydride, the addition product of 1,3-glycerol dimethacrylate and pyrromelletic anhydride, and acetoacetoxyethyl methacrylate. Compounds that would be useful would be 1,3-glycerol dimethacrylate (GDMA) and HEMA phosphate (HEMA-P).  
         [0014]     GDMA would preferably be present in an amount up to about 65 weight %. Most preferably, GDMA would be present in an amount up to about 51 weight %.  
         [0015]     HEMA-P would preferably be present in an amount of from 0 to about 10 weight %.  
         [0016]     The formulation may additionally contain amine photoreductant, for example ethyl 4-dimethylamino benzoate (4EDMAB), present in an amount of from 0 to about 4 weight %.  
         [0017]     Viscosity modifiers can also be used according to the invention. A number of suitable viscosity modifiers are commercially available, including, but not limited to, ultra fine inorganic fillers such as aerosil silica, aluminum oxide, and titanium dioxide. If desired, a silica glass powder, a barium glass powder, and the like may be used.  
         [0018]     All the percentages are on a dry weight basis unless otherwise stated.  
       EXAMPLE 1  
       [0019]     A formula was made with the following recipe:  
                                                                 Item   Measured                                        UDMA   35.94%           CQ   0.66%           BisGMA   57.27%           GDMA   3.35%           Hema-P   1.13%           4EDMAB   1.12%           DBS   0.53%                      
 
         [0020]     This formula produced a very thick hoof material with a viscosity greater than 100,000 cps.  
       EXAMPLE 2  
       [0021]     A formula was made with the following recipe:  
                                                   Item   Measured                           UDMA   76.18%           CQ    0.55%           BisGMA   21.71%           GDMA      0%           Hema-P    0.9%           4EDMAB    0.65%           DBS     0.%                      
 
         [0022]     This formula produced a thick hoof material with a viscosity between 20,000 and 100,000 cps.  
       EXAMPLE 3  
       [0023]     A formula was made with the following recipe:  
                                                   Item   Measured                           UDMA   30.0%            CQ   2.0%           BisGMA   30.0%            GDMA   31.0%            Hema-P   5.0%           4EDMAB   2.0%           DBS    0.%                      
 
         [0024]     This formula produced a thin hoof material with a viscosity lower than 20,000 cps.  
       EXAMPLE 4  
       [0025]    
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                   
               
               
                   
                   
               
               
                   
                 Item 
                 Lbs 
                 Grams 
                 % 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 Urethane Dimethacrylate 
                 10.6 
                   
                 35.4 
               
               
                   
                 Bis GMA 
                 9 
                   
                 30 
               
               
                   
                 1,3-Glycerol Dimethacrylate 
                 9.6 
                   
                 32 
               
               
                   
                 HEMA Phosphate 
                 0.2996 
                 136 
                 1 
               
               
                   
                 Camphorquinone 
                 0.1498 
                 68 
                 0.5 
               
               
                   
                 Ethyl-4- 
                 0.2996 
                 136 
                 1 
               
               
                   
                 Dimethylaminobenzoate 
               
               
                   
                 Hydroquinone 
                 0.0181 
                 8.2 
                 0.06 
               
               
                   
                   
                 29.9671 
                   
                 99.96 
               
               
                   
                   
               
             
          
         
       
     
       EXAMPLE 5  
       [0026]    
       
         
               
               
               
               
             
               
               
               
               
             
           
               
                   
               
               
                   
               
               
                 Item 
                 Lbs 
                 Grams 
                 % 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 Urethane Dimethacrylate 
                 8.7 
                   
                 34.9 
               
               
                 Bis GMA 
                 17.8 
                   
                 51.3 
               
               
                 1,3-Glycerol Dimethacrylate 
                 2.8 
                   
                 11.3 
               
               
                 HEMA Phosphate 
                 0.25 
                 113.4 
                 1 
               
               
                 Camphorquinone 
                 0.125 
                 56.7 
                 0.5 
               
               
                 Ethyl-4- 
                 0.25 
                 113.4 
                 1 
               
               
                 Dimethylaminobenzoate 
               
               
                 Methyl Ether of Hydroquinone 
                 0.005 
                 2.2 
                 0.0196 
               
               
                 Hydroquinone 
                 0.008 
                 3.4 
                 0.03 
               
               
                   
                 29.938 
                   
                 100.0496 
               
               
                   
               
             
          
         
       
     
       EXAMPLE 6  
       [0000]     Peanut Butter  
         [0027]     Very Thick Hoof Material Recipe  
                                                                             Item   Lbs.   Grams   %   Lbs.   %                                Urethane Dimethacrylate   15       34.9   15.0   35.89       Bis GMA   23.9       51.3   23.9   57.19       DiBenzyl Sorbitol       133.5       0.294   0.70       1,3-Glycerol       632.5   11.3   1.39   3.33       Dimethacrylate       HEMA Phosphate       210   1   0.46   1.11       Camphorquinone       126.8   0.5   0.28   0.67       Ethyl-4-       211   1   0.465   1.11       Dimethylaminobenzoate                   38.9       100   41.8                  
 
       EXAMPLE 7  
       [0028]     X 720 1000 Peanut Butter Hoof Repair Material  
                                                                               Item       Lbs   Grams   %                                BisGMA   X 9500 0000   28.5       57.20       Urethane dimethacrylate   X 850 0000   17.9       35.92       1,3-Glycerol   X 768 0000   1.65       3.31       Dimethacrylate       HEMA Phosphate   X 744 0000       249.5   1.10       Dibenzyl Sorbitol           158.7   0.70       Camphorquinone   X 801 0000       149.7   0.66       Ethyl 4-           249.5   1.10       dimethylaminobenzoate                49.83 Lbs total                      
 
       EXAMPLE 8  
       [0029]     X 720 0500 Thick Hoof Repair Material  
                                                                               Item       Lbs   Grams   %                                Urethane dimethacrylate   X 850 0000   8.7       34.89       BisGMA   X 950 0000   12.8       51.33       1,3-Glycerol   X 768 0000   2.8       11.23%       Dimethacrylate       HEMA Phosphate   x 744 0000       113.4   1.00       Camphorquinone   X 801 0000       56.7   0.50       Ethyl 4-           113.4   1.00       dimethylaminobenzoate       Hydroquinone           2.2   0.02       Hydroquinone           3.4   0.03                24.94 Lbs total                      
 
       EXAMPLE 9  
       [0030]     X 720 0500 Thin Hoof Repair Material  
                                                                               Item       Lbs   Grams   %                                Urethane   X 850 0000   10.6       35.37       dimethacrylate       BisGMA   X 950 0000   9       30.03       1,3-Glycerol   X 768 0000   9.6       32.04       Dimethacrylate       HEMA Phosphate   x 744 0000       136   1.00       Camphorquinone   X 801 0000       68   0.50       Ethyl 4-           136   1.00       dimethylaminobenzoate       Hydroquinone           8.2   0.06                29.97 Lbs total                      
 
         [0031]     For application to the hoof, an outline of a use protocol would be the following:  
         [0032]     1. Select the appropriate material. A thicker material would be beneficial for horses or cows with bad hooves, while the thin material may be all that is necessary for hoofs in a lesser state of disrepair.  
         [0033]     2. Paint the material on over the nails and/or in the cracks of the hoof in a dark area (such as the isle to a barn). The area need not be completely devoid of light, but should be dark enough to prevent the hardening of the material.  
         [0034]     3. Walk the animal such as the cow or horse out into the sun and the material will instantly harden. (A thin greasy film will remain on the hoof, but this will wear off over time). For thick cracks or holes in the hoof, the application of more than one layer may be required to completely fill the hole.  
         [0035]     4. Upon next shoeing (4-6 weeks) the material will be filed off and new material should then be applied.  
         [0036]     This material prevents horses from throwing their shoes off with ease, where the material is applied after the shoes have been nailed to the hoof.  
         [0037]     All the references described above are incorporated herein by reference in their entireties for all useful purposes.  
         [0038]     While there is shown and described certain specific structures embodying the invention, it will be manifest to those skilled in the art that various modifications and rearrangements of the parts may be made without departing from the spirit and scope of the underlying inventive concept and that the same is not limited to the particular forms herein shown and described.