Cotton fabrics are conventionally laundered in domestic washing machines using detergent compositions. However, the use of detergents that contain phosphates or other calcium ion sequestering builders can contribute to the formation of insoluble calcium salts in the wash, which are particularly noticeable on whiteness maintenance. The term whiteness maintenance is used herein to refer to the change in reflectance of the substrate, i.e., the treated fabric, between the original, untreated fabric, and the fabric after completion of the washing or rinsing process. A major problem arising from these insoluble salts is the loss of fabric whiteness on exposure to sunlight (photosensitized discolouration), which is a significant problem in the use of automatic laundry washing machines (see, for example, EP 0 679 903 B1).
EP 0 679 903 B1 discloses a means for overcoming this problem. The process described therein comprises treating a fabric-containing domestic laundry load with a water-soluble sunscreen chemical compound and thereafter treating the fabric with a water-soluble sunscreen scale inhibitor chemical compound. Examples of water-soluble sunscreen chemical compounds include aminobenzoic acid, salicylates, benzophenones, cinnamates, benzoates, resorcinol monobenzoate, bis-resorcinol mono- and bis-mono-cresols, triazoles and gallic and cinnamic acids. Examples of water-soluble sunscreen scale inhibitor chemical compounds include ethoxylated alkylphenols and water-soluble inorganic phosphates.
WO 00/14081 discloses a fabric washing composition comprising a calcium ion sequestering builder, a water-soluble calcium sequestering agent, and a water-soluble sunscreen scale inhibitor chemical compound that is different from the calcium sequestering builder.
WO 00/14097 discloses a fabric washing composition comprising a zeolite builder, a water-soluble calcium sequestering agent, and a water-soluble sunscreen scale inhibitor chemical compound that is different from the calcium sequestering builder.
As well as providing good cleaning of the fabric by the detergent components, there is also a need to protect the enzymes used in the detergent compositions from the degradation caused by calcium and magnesium ions in the water. Many detergent compositions comprise enzymes, for example, proteases, amylases, lipases and cellulases. The use of enzymes in such compositions has the advantages that they can be used at lower temperatures than the chemicals and therefore are more environmentally friendly and provide a more effective and specific cleaning action. However, the enzymes may be inactivated at higher temperatures by the detergent components themselves.
The present invention therefore also provides a process for protecting enzymes used in the detergent compositions from the degradation caused by calcium and magnesium ions in the water. This protection is provided by adding to the detergent compositions, components that remove calcium ions, said components being physically separated from the enzymes.
There is provided a process for treating a fabric with a detergent composition comprising a component to remove calcium ions from the wash solution and another component to remove magnesium ions from the wash solution, the components being physically separated in the detergent composition, wherein the component to remove calcium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition and the component to remove magnesium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition, the components being selected so that the component to remove calcium ions from the wash solution does not contain magnesium ions and the component to remove magnesium ions from the wash solution does not contain calcium ions.
The component to remove calcium ions from the wash solution comprises water-soluble calcium sequestrant. The component to remove magnesium ions from the wash solution comprises water-soluble scale inhibitor.
The detergent composition comprises a source of enzymes.
The present invention provides a process for treating a fabric with a detergent composition comprising components to remove calcium ions and magnesium ions from the wash solution, the components being physically separated in the detergent composition, wherein the component to remove calcium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition and the component to remove magnesium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition, the components being selected so that the component to remove calcium ions from the wash solution does not contain magnesium ions and the component to remove magnesium ions from the wash solution does not contain calcium ions.
The component to remove calcium ions from the wash solution comprises water-soluble calcium sequestrant. The component to remove magnesium ions from the wash solution comprises water-soluble scale inhibitor.
The detergent composition comprises a source of enzymes.
The present invention provides a detergent composition comprising a component to remove calcium ions from the wash solution and another component to remove magnesium ions from the wash solution, the components being physically separated in the detergent composition, wherein the component to remove calcium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition and the component to remove magnesium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition, the components being selected so that the component to remove calcium ions from the wash solution does not contain magnesium ions and the component to remove magnesium ions from the wash solution does not contain calcium ions.
The component to remove calcium ions from the wash solution comprises water-soluble calcium sequestrant. The component to remove magnesium ions from the wash solution comprises water-soluble scale inhibitor.
The present invention provides a process for treating a fabric with a detergent composition comprising a component to remove calcium ions from the wash solution and another component to remove magnesium ions from the wash solution, the components being physically separated in the detergent composition, wherein the component to remove calcium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition and the component to remove magnesium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition, the components being selected so that the component to remove calcium ions from the wash solution does not contain magnesium ions and the component to remove magnesium ions from the wash solution does not contain calcium ions.
The component to remove calcium ions from the wash solution comprises water-soluble calcium sequestrant. The component to remove magnesium ions from the wash solution comprises water-soluble scale inhibitor.
The present invention provides a detergent composition comprising a component to remove calcium ions from the wash solution and another component to remove magnesium ions from the wash solution, the components being physically separated in the detergent composition, wherein the component to remove calcium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition and the component to remove magnesium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition, the components being selected so that the component to remove calcium ions from the wash solution does not contain magnesium ions and the component to remove magnesium ions from the wash solution does not contain calcium ions.
The component to remove calcium ions from the wash solution comprises water-soluble calcium sequestrant. The component to remove magnesium ions from the wash solution comprises water-soluble scale inhibitor.
The present invention provides a process for treating a fabric with a detergent composition comprising a component to remove calcium ions from the wash solution and another component to remove magnesium ions from the wash solution, the components being physically separated in the detergent composition, wherein the component to remove calcium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition and the component to remove magnesium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition, the components being selected so that the component to remove calcium ions from the wash solution does not contain magnesium ions and the component to remove magnesium ions from the wash solution does not contain calcium ions.
The component to remove calcium ions from the wash solution comprises water-soluble calcium sequestrant. The component to remove magnesium ions from the wash solution comprises water-soluble scale inhibitor.
The present invention provides a detergent composition comprising a component to remove calcium ions from the wash solution and another component to remove magnesium ions from the wash solution, the components being physically separated in the detergent composition, wherein the component to remove calcium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition and the component to remove magnesium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition, the components being selected so that the component to remove calcium ions from the wash solution does not contain magnesium ions and the component to remove magnesium ions from the wash solution does not contain calcium ions.
The component to remove calcium ions from the wash solution comprises water-soluble calcium sequestrant. The component to remove magnesium ions from the wash solution comprises water-soluble scale inhibitor.
The present invention provides a process for treating a fabric with a detergent composition comprising a component to remove calcium ions from the wash solution and another component to remove magnesium ions from the wash solution, the components being physically separated in the detergent composition, wherein the component to remove calcium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition and the component to remove magnesium ions from the wash solution comprises from 5 to 50% by weight of the detergent composition, the components being selected so that the component to remove calcium ions from the wash solution does not contain magnesium ions and the component to remove magnesium ions from the wash solution does not contain calcium ions.
The component to remove calcium ions from the wash solution comprises water-soluble calcium sequestrant. The component to remove magnesium ions from the wash solution comprises water-soluble scale inhibitor.
In a preferred embodiment, the water-soluble calcium sequestrant is selected from a group comprising linear polycarboxylates, salicylic acid, gluconic
