Method for plating nonwoven fabric by using continuous electroless and electrolytic plating processes

Abstract

The present invention relates to: a method for plating nonwoven fabric with metals (copper and nickel, or nickel and nickel) by electroless and electrolytic continuous processes; and a nonwoven fabric plated by the method. The present invention can prepare a metal-plated nonwoven fabric by electrolytic plating a space of metal ions, which are formed by performing electroless plating with copper or nickel, with nickel in a short amount of time, thereby filling up the space, and thus has excellent conductivity while being thin. A desired conductivity can be obtained by changing the composition of a plating solution or controlling the plating velocity, and a line capable of performing plating with copper and nickel, nickel and nickel, nickel alone, or copper alone, in combination, can be manufactured. In addition, a highly conductive nonwoven fabric having no difference in plating thickness of nonwoven fabric performed by only electroless plating can be produced.

1 . A method for plating a non-woven fabric with metals through continuous electroless and electrolytic processes, the method comprising:
 (a) allowing a non-woven fabric to pass through an electroless plating liquid to plate the non-woven fabric with copper for 6-10 minutes, the electroless plating liquid containing, on the basis of the volume of pure water, 2.5-5.5 g/l Cu ions, 20-55 g/l EDTA, 2.5-4.5 g/l formalin, 2-6 g/l triethanolamine (TEA), 8-12 ml/l 25% NaOH, and 0.008-0.15 g/l 2,2′-bipiridine and having a pH of 12-13 and a temperature of 36-45° C.; and   (b) allowing the copper-plated non-woven fabric in step (a) to pass through an electrolytic plating liquid to plate the copper-plated non-woven fabric with nickel for 1-3 minutes, the electrolytic plating liquid containing 280-320 g/l Ni(NH 2 SO 3 ) 2 , 15-25 g/l NiCl 2 , and 35-45 g/l H 3 BO 3  and having a pH of 4.0-4.2 and a temperature of 50-60° C.   
     
     
         2 . (canceled) 
     
     
         3 . The method of  claim 1 , wherein the non-woven fabric is manufactured from a carbon fiber, a polyester fiber, a glass fiber, an aramid fiber, a ceramic fiber, a metal fiber, a polyimide fiber, a polybenzoxazole fiber, a natural fiber, or a mixed fiber thereof. 
     
     
         4 . The method of  claim 3 , wherein the polyester fiber is polyethylene terephthalate (PET), polyglycolide (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), polyethylene adipate (PEA), polybutylene succinate (PBS), poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), or Vectran. 
     
     
         5 . The method of  claim 1 , wherein in step (a), the non-woven fabric is allowed to pass through an electroless plating liquid to plate the non-woven fabric with copper for 6-10 minutes, the electroless plating liquid containing, on the basis of the volume of pure water, 4.5-5.5 g/l Cu ions, 45-55 g/l EDTA, 3.5-4.5 g/l formalin, 4-6 g/l triethanolamine (TEA), 8-12 ml/l 25% NaOH, and 0.01-0.15 g/l 2,2′-bipiridine and having a pH of 12-13 and a temperature of 40-45 ° C. 
     
     
         6 . The method of  claim 1 , wherein step (b) is performed by applying a constant voltage (CV) of 5-15 V. 
     
     
         7 . The method of  claim 1 , wherein the non-woven fabric in step (a) is pre-treated, before step (a), by a method comprising the following steps:
 (i) degreasing and softening the non-woven fabric by allowing the non-woven fabric to pass through an aqueous solution containing a surfactant, an organic solvent, and a non-ionic surfactant;   (ii) performing an etching process for neutralizing, cleaning, and conditioning actions by allowing the non-woven fabric as the product in step (a) to pass through an aqueous solution containing sodium bisulfite (NaHSO 3 ), sulfuric acid (H 2 SO 4 ), ammonium persulfate ((NH 4 ) 2 S 2 O 8 ), and pure water;   (iii) performing a sensitizing process by allowing the non-woven fabric as the product in step (ii) to an aqueous solution of PdCl 2 ; and   (iv) performing an activating process by allowing the non-woven fabric as the product in step (iii) to pass through an aqueous solution of sulfuric acid (H 2 SO 4 ).   
     
     
         8 . The method of  claim 7 , wherein the aqueous solution in step (i) contains: as a surfactant, 15-35 wt % of a solution in which pure water and NaOH are mixed at a weight ratio of 40-49:1-10; as organic solvents, 50-80 wt % of diethyl propanediol and 5-15 wt % of dipropylene glycol methyl ether; and 400-600 ppm of a non-ionic surfactant. 
     
     
         9 . The method of  claim 7 , wherein the aqueous solution in step (ii) contains 0.1-10 wt % of sodium bisulfite (NaHSO 3 ), 0.1-3 wt % of sulfuric acid (H 2 SO 4 ), 5-25 wt % of ammonium persulfate ((NH 4 ) 2 S 2 O 8 ), and 62-94.8 wt % of pure water. 
     
     
         10 . The method of  claim 7 , wherein step (i) is performed at a temperature of 40-60° C. for 1-5 min, step (ii) is performed at a temperature of 20-25° C. for 1-5 min, step (iii) is performed at a temperature of 20-40° C. for 1-5 min, and step (iv) is performed at a temperature of 40-60° C. for 1-5 min. 
     
     
         11 . A method for plating a non-woven fabric with metals through continuous electroless and electrolytic processes, the method comprising:
 (a) allowing a non-woven fabric to pass through an electroless plating liquid to plate the non-woven fabric with nickel for 6-10 minutes, the electroless plating liquid containing, on the basis of the volume of pure water, 5-7 g/l Ni ions, 20-30 g/l NaH 2 PO 2 , 20-30 g/l Na 3 C 6 H 5 O 7 , and 0.0005-0.001 g/l potassium thiosulfate and having a pH of 8.5-9.5 and a temperature of 30-35° C.; and   (b) allowing the nickel-plated non-woven fabric in step (a) to pass through an electrolytic plating liquid to plate the nickel-plated non-woven fabric with nickel for 1-3 minutes, the electrolytic plating liquid containing 280-320 g/l Ni(NH 2 SO 3 ) 2 , 15-25 g/l NiCl 2 , and 35-45 g/l H 3 BO 3  and having a pH of 4.0-4.2 and a temperature of 50-55° C.   
     
     
         12 . The method of  claim 11 , wherein the non-woven fabric is manufactured from a carbon fiber, a polyester fiber, a glass fiber, an aramid fiber, a ceramic fiber, a metal fiber, a polyimide fiber, a polybenzoxazole fiber, a natural fiber, or a mixed fiber thereof. 
     
     
         13 . The method of  claim 12 , wherein the polyester fiber is polyethylene terephthalate (PET), polyglycolide (PGA), polylactic acid (PLA), polycaprolactone (PCL), polyhydroxyalkanoate (PHA), polyhydroxybutyrate (PHB), polyethylene adipate (PEA), polybutylene succinate (PBS), poly(3-hydroxybutyrate-co-3-hydroxyvalerate (PHBV), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polyethylene naphthalate (PEN), or Vectran. 
     
     
         14 . The method of  claim 11 , wherein step (b) is performed by applying a constant voltage (CV) of 5-15 V. 
     
     
         15 . The method of  claim 11 , wherein the non-woven fabric in step (a) is pre-treated, before step (a), by a method comprising the following steps:
 (i) degreasing and softening the non-woven fabric by allowing the non-woven fabric to pass through an aqueous solution containing a surfactant, an organic solvent, and a non-ionic surfactant;   (ii) performing an etching process for neutralizing, cleaning, and conditioning actions by allowing the non-woven fabric as the product in step (a) to pass through an aqueous solution containing sodium bisulfite (NaHSO 3 ), sulfuric acid (H 2 SO 4 ), ammonium persulfate ((NH 4 ) 2 S 2 O 8 ), and pure water;   (iii) performing a sensitizing process by allowing the non-woven fabric as the product in step (ii) to an aqueous solution of PdCl 2 ; and   (iv) performing an activating process by allowing the non-woven fabric as the product in step (iii) to pass through an aqueous solution of sulfuric acid (H 2 SO 4 ).   
     
     
         16 . The method of  claim 15 , wherein the aqueous solution in step (i) contains: as a surfactant, 15-35 wt % of a solution in which pure water and NaOH are mixed at a weight ratio of 40-49:1-10; as organic solvents, 50-80 wt % of diethyl propanediol and 5-15 wt % of dipropylene glycol methyl ether; and 400-600 ppm of a non-ionic surfactant. 
     
     
         17 . The method of  claim 15 , wherein the aqueous solution in step (ii) contains 0.1-10 wt % of sodium bisulfite (NaHSO 3 ), 0.1-3 wt % of sulfuric acid (H 2 SO 4 ), 5-25 wt % of ammonium persulfate ((NH 4 ) 2 S 2 O 8 ), and 62-94.8 wt % of pure water. 
     
     
         18 . The method of  claim 15 , wherein step (i) is performed at a temperature of 40-60° C. for 1-5 min, step (ii) is performed at a temperature of 20-25° C. for 1-5 min, step (iii) is performed at a temperature of 20-40° C. for 1-5 min, and step (iv) is performed ata temperature of 40-60° C. for 1-5 min.