Cleaning compositions for solid surfaces – auxiliary compositions – Cleaning compositions or processes of preparing – Solid – shaped macroscopic article or structure
Reexamination Certificate
2003-05-08
2004-12-14
Douyon, Lorna M. (Department: 1751)
Cleaning compositions for solid surfaces, auxiliary compositions
Cleaning compositions or processes of preparing
Solid, shaped macroscopic article or structure
C510S224000, C510S228000, C510S231000, C510S444000, C510S451000, C510S469000, C510S509000, C510S510000
Reexamination Certificate
active
06831054
ABSTRACT:
FIELD OF THE INVENTION
The invention relates to substantially inorganic mild alkaline detergent materials that can be manufactured in the form of a solid block and packaged for sale. In the manufacture of the solid detergent a detergent mixture is extruded to form the solid. The solid water soluble or dispersible detergent is typically uniformly dispensed, without undershoot or overshoot of detergent concentration, from a spray-on type dispenser which creates an aqueous concentrate by spraying water onto the soluble solid product. The aqueous concentrate is directed to a use locus such as a warewashing machine.
BACKGROUND OF THE INVENTION
The use of solid block detergents in institutional and industrial cleaning operations was pioneered in technology claimed in the Fernholz et al. U.S. Reissue Pat. Nos. 32,762 and 32,818. Further, pelletized materials are shown in Gladfelter et al., U.S. Pat. Nos. 5,078,301, 5,198,198 and 5,234,615. Extruded materials are disclosed in Gladfelter et al., U.S. Pat. No. 5,316,688, The solid block format is a safe, convenient and efficient product format.
In the pioneering technology, substantial attention was focused on how the highly alkaline material, based on a substantial proportion of sodium hydroxide, was cast and solidified. Initial solid block products (and predecessor powder products) used a substantial proportion of a solidifying agent, sodium hydroxide hydrate, to solidify the cast material in a freezing process using the low melting point of sodium hydroxide monohydrate (about 50° C.-65° C.). The active components of the detergent were mixed with the molten sodium hydroxide and cooled to solidify. The resulting solid was a matrix of hydrated solid sodium hydroxide with the detergent ingredients dissolved or suspended in the hydrated matrix. In this prior art cast solid and other prior art hydrated solids, the hydrated chemicals are reacted with water and the hydration reaction is run to substantial completion. The sodium hydroxide also provided substantial cleaning in warewashing systems and in other use loci that require rapid and complete soil removal. In these early products sodium hydroxide was an ideal candidate because of the highly alkaline nature of the caustic material provided excellent cleaning. Another sodium hydroxide and sodium carbonate cast solid process using substantially hydrated sodium materials was disclosed in Heile et al. U.S. Pat. Nos. 4,595,520 and 4,680,134.
Similarly, pioneering technology relating to the use of solid pelleted alkaline detergent compositions in the form of a water soluble bag assembly and an extruded alkaline solid material wrapped in a water soluble film has also been pioneered by Ecolab Inc. These products within the water soluble bag can be directly inserted into a spray on dispenser wherein water dissolves the bag and contacts the soluble pellet or extruded solid, dissolves the effective detergent ingredients, creates an effective washing solution which is directed to a use locus.
In recent years, attention has been directed to producing a highly effective detergent material from less caustic materials such as soda ash, also known as sodium carbonate, because of manufacturing, processing, etc. advantages. Sodium carbonate is a mild base, and is substantially less strong (has a smaller K
b
) than sodium hydroxide. Further on an equivalent molar basis, the pH of the sodium carbonate solution is one unit less than an equivalent solution of sodium hydroxide (an order of magnitude reduction in strength of alkalinity). Sodium carbonate formulations were not given serious consideration in the industry for use in heavy duty cleaning operations because of this difference in alkalinity. The industry believed carbonate could not adequately clean under the demanding conditions of time, soil load and type and temperature found in the institutional and industrial cleaning market. A few sodium carbonate based formulations have been manufactured and solid in areas where cleaning efficiency is not paramount. Further solid detergents made of substantially hydrated, the carbonate content contained at least about seven moles of water of hydration per mole of carbonate, sodium carbonate were not dimensionally stable. The substantially hydrated block detergent tended to swell and crack upon aging. This swelling and cracking was attributed to changing of the sodium carbonate hydration states within the block. Lastly, molten hydrate processing can cause stability problems in manufacturing the materials. Certain materials at high melting temperatures in the presence of water can decompose or revert to less active or inactive materials.
Accordingly, a substantial need for mechanically stable solid carbonate detergent products, having equivalent cleaning performance when compared to caustic based detergents, has arisen. Further, a substantial need has arisen for successful non-molten processes for manufacturing sodium carbonate based detergents that form a solid with minimal amounts of water of hydration associated with the sodium base. These products and processes must combine ingredients and successfully produce a stable solid product that can be packaged, stored, distributed and used in a variety of use locations.
BRIEF DISCUSSION OF THE INVENTION
The invention involves a solid block detergent based on a combination of a carbonate hydrate and a non-hydrated carbonate species solidified by a novel hydrated species we call the E-form hydrate composition. The solid can contain other cleaning ingredients and a controlled amount of water. The solid carbonate based detergent is solidified by the E-form hydrate which acts as a binder material or binding agent dispersed throughout the solid. The E-form binding agent comprises at a minimum an organic phosphonate and water and can also have associated carbonate. The solid block detergent uses a substantial proportion, sufficient to obtain cleaning properties, of hydrated carbonate and non-hydrated carbonate formed into solid in a novel structure using a novel E-form binder material in a novel manufacturing process. The solid integrity of the detergent, comprising anhydrous carbonate and other cleaning compositions, is maintained by the presence of the E-form binding component comprising an organic phosphonate, substantially all water added to the detergent system and an associated fraction of the carbonate. This E-form hydrate binding component is distributed throughout the solid and binds hydrated carbonate and non-hydrated carbonate and other detergent components into a stable solid block detergent.
The alkali metal carbonate is used in a formulation that additionally includes an effective amount of a hardness sequestering agent that both sequesters hardness ions such as calcium, magnesium and manganese but also provides soil removal and suspension properties. The formulations can also contain a surfactant system that, in combination with the sodium carbonate and other components, effectively removes soils at typical use temperatures and concentrations. The block detergent can also contain other common additives such as surfactants, builders, thickeners, soil anti-redeposition agents, enzymes, chlorine sources, oxidizing or reducing bleaches, defoamers, rinse aids, dyes, perfumes, etc.
Such block detergent materials are preferably substantially free of a component that can compete with the alkali metal carbonate for water of hydration and interfere with solidification. The most common interfering material comprises a second source of alkalinity. The detergent preferably contains less than a solidification interfering amount of the second alkaline source, and can contain less than 5 wt %, preferably less than 4 wt %, of common alkalinity sources including either sodium hydroxide or an alkaline sodium silicate wherein the ratio Na
2
O:SiO
2
is greater than or equal to about 1. While some small proportion sodium hydroxide can be present in the formulation to aid in performance, the presence of a substantial amount of sodium hydroxide can interfere with solidification. S
Lentsch Steven E.
Olson Keith E.
Wei G. Jason
Douyon Lorna M.
Ecolab Inc.
Merchant & Gould P.C.
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