Cellulosic fiber composites using protein hydrolysates and methods of making same

Abstract

A method of preparing a cellulosic fiber composite is provided comprising mixing protein hydrolysates and a synthetic resin to produce a resin binder. The synthetic resin can be phenolic resin, isocyanate resin, or combinations thereof. The method further comprises mixing the resin binder with a cellulosic material to form a cellulosic material/resin binder blend, felting the blend to form a low-moisture content mat, and pressing the mat at an elevated temperature and pressure, producing the cellulosic fiber composite. The amount of the resin binder can be between about 2% and about 15% of the dry weight of the cellulosic material. The protein hydrolysates provide a composite with a reduced amount of petrochemicals. The composite can also contain a silicone, silane, or combination thereof. The low moisture-content mat does not require drying prior to pressing. Additional methods can be employed to produce finished cellulosic fiber composite articles.

What is claimed is:  
     
         1 . A method of preparing a cellulosic fiber composite comprising: 
 mixing a protein hydrolysate with a synthetic resin, wherein the synthetic resin is phenolic resin, isocyanate resin, or combinations thereof, to produce a resin binder;    mixing the resin binder with a cellulosic material to form a cellulosic material/resin binder blend;    felting the cellulosic material/resin binder blend to form a low moisture-content mat; and    pressing the low moisture-content mat at an elevated temperature and pressure, producing the cellulosic fiber composite.    
     
     
         2 . The method of  claim 1  wherein the amount of the resin binder is between about 2% and about 15% of the dry weight of the cellulosic material.  
     
     
         3 . The method of  claim 1  wherein the amount of the resin binder is between about 4% and about 8% of the dry weight of the cellulosic material.  
     
     
         4 . The method of  claim 1  wherein the amount of the resin binder is between about 4% and about 6% of the dry weight of the cellulosic material.  
     
     
         5 . The method of  claim 1  wherein the amount of the resin binder is between about 4% and about 5% of the dry weight of the cellulosic material.  
     
     
         6 . The method of  claim 1  further comprising adjusting the moisture content of the cellulosic fiber composite to a predetermined amount.  
     
     
         7 . The method of  claim 1  wherein the average moisture content of the cellulosic material is between about 8% and about 35% by weight after application of the resin binder.  
     
     
         8 . The method of  claim 1  wherein the protein hydrolysate is made by hydrolyzing a source of protein with sodium carbonate.  
     
     
         9 . The method of  claim 1  wherein the protein is animal protein, vegetable protein, or combinations thereof.  
     
     
         10 . The method of  claim 9  wherein the vegetable protein is soy protein.  
     
     
         11 . The method of  claim 10  wherein the soy protein is soy isolate.  
     
     
         12 . The method of  claim 10  wherein the soy protein is soy flour.  
     
     
         13 . The method of  claim 10  wherein the soy protein is a blend of soy isolate and soy flour.  
     
     
         14 . The method of  claim 13  wherein the weight ratio of the blend of the soy isolate to the soy flour is about 50:50.  
     
     
         15 . The method of  claim 1  wherein the synthetic resin is phenolic resin.  
     
     
         16 . The method of  claim 15  wherein the phenolic resin is phenol formaldehyde.  
     
     
         17 . The method of  claim 15  wherein the resin binder has a weight ratio of protein hydrolysate to phenolic resin between about 10:90 and about 90:10.  
     
     
         18 . The method of  claim 15  wherein the resin binder has a weight ratio of protein hydrolysate to phenolic resin between about 10:90 and about 75:25.  
     
     
         19 . The method of  claim 15  wherein the resin binder has a weight ratio of protein hydrolysate to phenolic resin between about 25:75 and about 75:25.  
     
     
         20 . The method of  claim 15  wherein the resin binder has a weight ratio of protein hydrolysate to phenolic resin between about 25:75 and about 50:50.  
     
     
         21 . The method of  claim 1  wherein the synthetic resin is isocyanate resin.  
     
     
         22 . The method of  claim 21  wherein the isocyanate resin is polymeric isocyanate.  
     
     
         23 . The method of  claim 21  wherein the resin binder has a weight ratio of protein hydrolysates to isocyanate resin between about 10:90 and about 90:10.  
     
     
         24 . The method of  claim 21  wherein the resin binder has a weight ratio of protein hydrolysates to isocyanate resin between about 10:90 and about 75:25.  
     
     
         25 . The method of  claim 21  wherein the resin binder has a weight ratio of protein hydrolysate to isocyanate resin between about 25:75 and about 75:25.  
     
     
         26 . The method of  claim 21  wherein the resin binder has a weight ratio of protein hydrolysates to isocyanate resin between about 25:75 and about 50:50.  
     
     
         27 . The method of  claim 1  wherein the synthetic resin is a combination of phenolic resin and isocyanate resin.  
     
     
         28 . The method of  claim 27  wherein the weight ratio of the isocyanate resin to the total of the protein hydrolysates and the phenolic resin is between about 25:75 and about 75:25.  
     
     
         29 . The method of  claim 21  wherein the amount of isocyanate resin making up the composite is about 1% to about 6% based on the total weight of the cellulosic material.  
     
     
         30 . The method of  claim 21  wherein the amount of isocyanate resin making up the composite is about 1% to about 3% based on the total weight of the cellulosic material.  
     
     
         31 . The method of  claim 21  wherein the amount of isocyanate resin making up the composite is about 1% to about 2% based on the total weight of the cellulosic material.  
     
     
         32 . The method of  claim 1  wherein the synthetic resin further comprises paraformaldehyde.  
     
     
         33 . The method of  claim 32  wherein the weight ratio of the paraformaldehyde to the total of the protein hydrolysates and the synthetic resin is between about 2:48 and about 15:35 based on 50% resin solids.  
     
     
         34 . The method of  claim 1  wherein the synthetic resin further comprises high methylol content phenol formaldehyde pre-polymer.  
     
     
         35 . The method of  claim 34  wherein the molar ratio of formaldehyde to phenol to NaOH of the high methylol content phenol formaldehyde pre-polymer is about 2:1:0.5.  
     
     
         36 . The method of  claim 34  wherein the weight ratio of the high methylol content phenol formaldehyde pre-polymer to the total of the protein hydrolysates and the synthetic resin is between about 10:90 and about 90:10.  
     
     
         37 . The method of  claim 34  wherein the weight ratio of the high methylol content phenol formaldehyde pre-polymer to the total of the protein hydrolysates and the synthetic resin is between about 25:75 and about 75:25.  
     
     
         38 . The method of  claim 1  wherein the resin binder further comprises a silicone, silane, or combination thereof.  
     
     
         39 . The method of  claim 1  that further comprises applying a coating to the composite, wherein the coating is a silicone, silane, or combination thereof.  
     
     
         40 . The method of  claim 38  wherein the amount of silicone, silane, or combination thereof is between about 0.1% and about 1.0% based on the total amount of the cellulosic material.  
     
     
         41 . The method of  claim 39  wherein the amount of silicone, silane, or combination thereof is between about 0.1% and about 1.0% based on the total amount of the cellulosic material.  
     
     
         42 . A method of preparing a finished cellulosic fiber composite article comprising: 
 mixing a protein hydrolysate with a synthetic resin, wherein the synthetic resin is phenolic resin, isocyanate resin, or combinations thereof, to produce a resin binder;    mixing the resin binder with a cellulosic material to form a cellulosic material/resin binder blend;    felting the cellulosic material/resin binder blend to form a low moisture-content mat; and    molding the low moisture-content mat at an elevated temperature and pressure, producing the finished cellulosic fiber composite article.    
     
     
         43 . The method of  claim 42  that further comprises applying a laminate overlay to the finished cellulosic fiber composite article.