Polymers and laundry detergent compositions containing them

Preparation of Vinyl Pyrrolidone / vinyl 2-ethylhexanoate Copolymers

[0064] The following copolymers were prepared by free radical polymerisation. The preparation was adapted from the process described in U.S. Pat. No. 5,319,041 (Zhong et al).

2 Weight % Weight % Example vinyl pyrrolidone vinyl 2-ethyl hexanoate 1 99 1 2 98 2 3 96 4 4 92 8

[0065] The starting materials used were as follows (* denotes Trade Mark):

3 Name Chemical name Supplier Function VP Vinylpyrrolidone Aldrich Monomer V2EH Vinyl 2-ethylhexanoate Aldrich Monomer Vazo* 67 2,2-azobis(2- Fluka Initiator methylbutyronitrile) Luperox* 101 2,5-bis(tert-butylperoxy)-Aldrich Initiator 2,5-dimethylhexane Butanol n-Butanol Solvent

Experimental Procedure

[0066] The polymers were prepared using a four-step procedure as described below.

[0067] The relative weights of VP and V2EH required were calculated in function of the % of hydrophobic units needed in the final copolymer. For example, the total quantities required to make a 200 g batc

Detergency / antiredeposition Performance

[0078] Detergency and antiredeposition performance of the polymers were evaluated by a small scale wash method, using a laundry detergent composition having the following formulation:

9 Weight % Linear alkylbenzene sulphonate 6.00 Sodium C.sub.12-C.sub.14 alcohol ethoxy sulphate 3EO 10.50 Nonionic surfactant 6.60 (C.sub.12-C.sub.14 alcohol ethoxylate, 9EO) Sodium citrate dihydrate 3.20 Propylene glycol 4.75 Sorbitol 3.25 Sodium borate pentahydrate 2.13 (Water to 100.00)

[0079] This formulation has a pH of 7.0. In the doseage 1 g / L and 2 g / L it has a pH of 8.8.

Methodology

[0080] The polymers were tested for their ability to enhance the removal of oily and clay / sebum soil from white cotton fabric, using an apparatus for simulating a soiling and wash procedure on a small scale.

[0081] Using this apparatus, the fabric was soiled, and subjected to a simulated main wash procedure using wash liquors with and without the polymer according to the inven