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Chemical name: Alkyl Ketene Dimer
Alias: AKD wax
Alkyl ketene dimer is a common compound neutral sizing agent of
papermaking. The structural formula is as follows:
R or R' in the above structural formula is the alkyl group, and a series of alkyl ketene dimers can be obtained through modifying different alkyl groups. Octodecane and cetane are applicable to the papermaking neutral sizing agent.
Alkyl ketene dimer is a white-to-yellow solid with the melting point of about 47 ¡« 51 ¡æ , which can be soluble in ethyl alcohol, benzene, chloroform and other organic solvents.
The reactive group of alkyl ketene dimer-ketone group has high activity
and makes esterification reaction with the hydroxyl in cellulose.
2. Specification
Appearance: Light yellow granule
M.P.: 47¡æ
Iodine number£¨I2£©,w/(g/100g): 45.0min
Acid value(KOH), w/(g/100g): 5.0max
Purity: 88%min
Toluene: 0.001%max.
3. Product Application
AKD wax can be made into AKD emulsion applied as in sizing agent in the papermaking production.
AKD wax is emulsified by the cationic emulsifier, and melted AKD wax and emulsifier undergo high-speed shearing and high pressure homogenization to form the liquid AKD sizing agent after cooled.
In the papermaking process, application of AKD sizing agent gives the fluid resistance to paper and paperboard to prevent or delay the penetration and diffusion of some liquids on paper fibers, thus satisfying people's requirements on the processing and use of paper products.
AKD contains hydrophobic group and hydrophilic group, which are well distributed in the sizing process to transfer to locate the process of bonding with cellulose. AKD emulsion particles stay between negatively charged paper fibers since they carry with positive charge by virtue of cationic starch and PAM and other retention agents; In the pressing and drying process of the paper machine, these globular AKD particles are easily expanded and distributed on the surface of fibers due to the lower melting point to form a homogeneous cover film; When paper is dried and stored for a period, the active group (lactone ring) on AKD molecule makes the esterification reaction with the hydroxyl on fibers under certain conditions to be binding on fibers in the form of fixed covalent bonds. Hydrophobic long-chain alkyls transfer to the paper surface in order to give the penetration resistance to paper.
Also we can supply AKD Sizing Agent Series
