Softener concentrate, softener emulsion, method for producing softener emulsion and its use

1 . A softener concentrate to be emulsified with water to form an oil-in-water softener emulsion for use in manufacture of a paper, tissue or paperboard, comprising:

5 to 10 wt % of an imidazoline-based surfactant with a carbon chain of 16 to 18 carbon atoms based on the total weight of the softener concentrate;

5 to 10 wt % of a lanolin-based softener based on the total weight of the softener concentrate;

5 to 20 wt % of phospholipids based on the total weight of the softener concentrate; and

60 to 85 wt % of a surfactant blend based on the total weight of the softener concentrate comprising polysorbate ester, sorbitan ester-based surfactants, polypropylene glycol, polyethylene glycol, and their esters, silicon-based softeners, or any combination thereof.

2 . The softener concentrate according to claim 1 , wherein the concentrate comprises 5 wt % imidazoline-based surfactant, 5 wt % lanolin-based softener, 10 wt % phospholipids, and 80 wt % surfactant blend, of the total weight of the softener concentrate.

3 . The softener concentrate according to claim 1 , wherein the lanolin-based softener comprises USP grade lanolin.

4 . The softener concentrate according to claim 1 , wherein the phospholipids comprise lecithin.

5 . The softener concentrate according to claim 1 , wherein the softener concentrate is substantially free of water.

6 . A softener emulsion for use in manufacture of paper, tissue or paperboard comprising:

20 to 50 wt-% of the softener concentrate according to claim 1 , and

50 to 80 wt-% of water,

of the total weight of the softener emulsion.

7 . A process for making paper, tissue or paperboard, wherein a softener emulsion according to claim 6 is added to fiber slurry having a consistency of 0.05 wt. % to 8 wt. % at the wet end of a paper machine, and/or a softener emulsion according to claim 6 is applied on a wet fiber web having a moisture level of 30 to 90% as weight percentage of water in the wet fiber web, and/or a softener emulsion according to claim 6 is applied on a dry sheet of paper or a converted roll of paper having a moisture level of less than 12%, as weight percentage of water in the dry sheet of paper or the converted roll.

8 . The softener emulsion according to claim 6 , wherein the softener emulsion further comprises an electrolyte selected from soluble salts, acids, bases, polyelectrolytes, and any combination thereof.

9 . The softener emulsion according to claim 6 , wherein the softener emulsion comprises an electrolyte in an amount of 0.01 to 1.0 wt-% of the weight of the softener emulsion, and wherein the softener emulsion has a viscosity lower than 500 cPs measured with a Brookfield Viscometer, DV2T, with #63 spindle and spindle rotation speed at 30 rpm at ambient temperature.

10 . A process for producing a softener emulsion, the process comprising:

providing a softener concentrate according to claim 1 ,

emulsifying the softener concentrate with water, thus forming a softener emulsion comprising 20 to 50 wt-% softener concentrate of the total weight of the softener emulsion, and

treating the softener emulsion with a high shear homogenizer and/or ultrasonic energy, thus reducing viscosity of the softener emulsion.

11 . The process according to claim 10 , wherein the process further comprises adding an electrolyte selected from soluble salts, acids, bases, polyelectrolytes, and any combination thereof.

12 . The process according to claim 11 , wherein the electrolyte is added before, during and/or after the emulsifying step, and/or the electrolyte is added before, during and/or after the high shear homogenizer and/or the ultrasonic energy treatment.

13 . The process according to claim 11 , wherein the electrolyte is added in an amount of 0.01-1.0 wt. % of the weight of the softener emulsion.

14 . The process according to claim 10 , wherein the softener emulsion is treated with the ultrasonic energy treatment for a period of 1 to 60 min.