Contamination-preventing agent composition and contamination preventing method

Abstract

To provide a contamination-preventing agent composition and a contamination preventing method which even if the composition is imparted only to a dryer on the upstream side, a sufficient amount of the composition can be imparted to a dryer on the downstream side via a wet paper, and pitch contamination of a plurality of dryers can be prevented sufficiently as a whole. The present invention is a contamination-preventing agent composition imparted to dryers D 1 to D 8 in a dry part D of a paper machine and comprising an emulsion, a re-transfer agent and water, wherein the re-transfer agent has a cloud point of 55° C. or higher and an HLB value of 8 to 15, and preferably a contamination-preventing agent composition wherein the dynamic surface tension value at a lifetime of 100 ms by a maximum bubble pressure method is 65 mN/m or less.

1 . A contamination-preventing agent composition imparted to a dryer in a dry part of a paper machine and comprising an emulsion, a re-transfer agent and water, wherein said re-transfer agent has a cloud point of 55° C. or higher and an HLB value of 8 to 15. 
     
     
         2 . The contamination-preventing agent composition according to  claim 1 , wherein the dynamic surface tension value at a lifetime of 100 ms by a maximum bubble pressure method is 65 mN/m or less. 
     
     
         3 . The contamination-preventing agent composition according to  claim 1 , wherein said dryer is made of cast iron, and the contact angle to the cast iron is 70° or less. 
     
     
         4 . The contamination-preventing agent composition according to  claim 1 , wherein said re-transfer agent is at least one selected from the group consisting of polyoxyalkylene alkyl ether, polyoxyalkylene fatty acid ester, polyoxyalkylene sorbitan fatty acid ester and polyoxyalkylene sorbitol fatty acid ester. 
     
     
         5 . The contamination-preventing agent composition according to  claim 1 , wherein said emulsion is composed of a non-silicone oil, water and an emulsifier, and said non-silicone oil is at least one selected from the group consisting of polybutenes, synthetic ester oils, mineral oils, vegetable oils and liquid paraffins. 
     
     
         6 . The contamination-preventing agent composition according to  claim 5 , wherein the compounding ratio of said re-transfer agent with respect to 10% by mass of said non-silicone oil is 0.1% by mass to 10% by mass. 
     
     
         7 . The contamination-preventing agent composition according to  claim 1 , wherein the compounding ratio of said re-transfer agent is 0.01% by mass to 10% by mass. 
     
     
         8 . The contamination-preventing agent composition according to  claim 1 , wherein a coating film is formed by being imparted to said dryer, and a part of said coating film is re-emulsified when the coating film comes in contact with a wet paper. 
     
     
         9 . A contamination preventing method, comprising
 a first step of imparting the contamination-preventing agent composition according to  claim 1  to a dryer on the upstream side to form a coating film,   a second step of bringing a wet paper into contact with the coating film to re-emulsify a part of the coating film and transfer the re-emulsified emulsion to the wet paper, and   a third step of bringing said wet paper carrying said emulsion into contact with a dryer on the downstream side to impart said emulsion to the dryer on the downstream side.