WO1994028104A1

WO1994028104A1 - Bleaching compositions comprising peroxyacid activators having amide moieties

Info

Publication number: WO1994028104A1
Application number: PCT/US1994/005370
Authority: WO
Inventors: Alan David Willey; Michael Eugene Burns; Richard Timothy Hartshorn
Original assignee: The Procter & Gamble Company
Priority date: 1993-05-20
Filing date: 1994-05-12
Publication date: 1994-12-08
Also published as: CZ305895A3; HU9503298D0; CA2161211C; JPH08510778A; EP0699233B1; BR9406307A; HUT73730A; DE69417413D1; CN1057792C; HU216639B; AU6949294A; CN1124038A; DE69417413T2; ATE178091T1; EP0699233A1

Abstract

The present invention relates to a method of cleaning fabrics in washing machines which have parts made of natural rubber using laundry detergents comprising amido-derived bleaching activators and a source of hydrogen peroxide such that said natural rubber parts of said machines are substantially undamaged by products of the perhydrolysis reaction between the activator and hydrogen peroxide.

Description

BLEACHING COMPOSITIONS COMPRISING PEROXYACID ACTIVATORS HAVING AMIDE MOIETIES

FIELD OF THE INVENTION The present invention relates to laundry detergents with activated bleaching systems.

BACKGROUND OF THE INVENTION It has long been known that peroxygen bleaches are effective for stain and or soil removal from fabrics, but that such bleaches are temperature dependent. At a wash liquor temperature of 60 C, peroxygen bleaches are only partially effective As the wash liquor temperature is lowered below 60 C, peroxygen bleaches become relatively ineffective As a consequence, there has been a substantial amount of industrial research to develop bleaching systems which contain an activator that renders peroxygen bleaches effective at wash liquor temperatures below 60 C.

Numerous substances have been disclosed in the art as effective bleach activators. One widely-used bleach activator is tetraacetyl ethylene diamine (TAED). TAED provides effective hydrophiiic cleaning especially on beverage stains, but has limited performance on dingy, yellow stains such as those resulting from body oils Another type of activator, such as nonanoyl- oxybenzenesulfonate (NOBS) and other activators which generally comprise long chain alkyl moieties, is hydrophobic in nature and provides excellent performance on dingy stains However, many of the hydrophobic activators developed thus far can promote damage to natural rubber parts used in certain washing machines Because of these negative effects on washing machine parts, the selection of such detergent-added bleaching systems has long been limited. This is especially true for European detergent/bleaches, since many washing machines manufactured in Europe have been equipped with key parts, such as sump hoses and motor gaskets, made of natural rubber A need, therefore, exists for a bleaching system which provides dingy soil clean up without substantially damaging the natural rubber parts found in washing machines.

It has now been determined that in conventional bleaching systems, typically comprising a hydrophobic bleach activator and a source of hydrogen peroxide, the activator undergoes perhydrolysis to form a peroxyacid bleaching agent. A by-product of the perhydrolysis reaction between such bleach activators and hydrogen peroxide is a diacylperoxide (DAP) species. It has now further been discovered that the DAP's derived from hydrophobic bleaching activators tend to be insoluble, pooriy dispersible, oily materials which form a residue which can deposit on the natural rubber machine parts that are exposed to the wash liquor. The oily DAP residue can form a film on the natural rubber parts and promote free radical and peroxide damage to the rubber, which eventually leads to failure of the parts. This is particularly true of rubber parts which have prolonged exposure to the wash liquor, such as sump hoses.

By the present invention, it has now been discovered that the class of hydrophobic bleach activators derived from amido acids forms hydrophobic amido peracids upon perhydrolysis without the production of harmful, oily DAP's Without limiting the invention herein, it is believed that the DAP's produced by the perhydrolysis reaction of the amido acid-derived bleach activators are insoluble crystalline solids. Such solid DAP's do not form a coating film. Accordingly, the natural rubber machine parts are not exposed to the DAP's for extended periods of time and remain substantially undamaged by the bleaching system of the present invention. The present invention thus solves the long-standing need for an effective hydrophobic bleaching system which does not promote free radical and peroxide damage to natural rubber parts in washing machines The invention provides a method of cleaning fabrics with a bleaching system in washing machines which have parts made of natural rubber such that the natural rubber is substantially undamaged by the bleaching system. BACKGROUND ART

U.S. Patent 4.634,551, Bums et al, issued January 6, 1987, discloses amido peroxyacid bleaching compounds and their precursors of the type employed in the present invention. See also, U.S. Patent 4,852,989, Burns et al, issued August 1, 1989, and U.S. Patent 4,966,723, Hodge et al, issued Oct. 30, 1990. SUMMARY OF THE INVENTION The present invention relates to a method for cleaning fabrics in automatic washing machines having parts made of natural rubber which is susceptible to oxidative degradation. The method comprises agitating fabrics in said washing machine in an aqueous liquor comprising a bleaching system comprising a bleach activator which reacts with a source of peroxide in said aqueous liquor to yield a peroxyacid without the formation of oily diacylperoxide (DAP) such that said natural rubber parts are substantially undamaged by the by-products of said reaction. The amido-derived peroxyacids generated by the reaction are of the general formulas:

O 0 0 0

II II II II

R1-C-N-R2-C-OOH R-^-N-C-R2-C-OOH

I I R5 R5 i wherein R is an al yl, aryl, or alkaryl group containing from about I to about

2 14 carbon atoms, R is an alkylene, arylene or alkaryiene group containing from about 1 to about 1 carbon atoms, and R is H or an alkyl, aryl, or alkaryl group containing from about 1 to about 10 carbon atoms.

The bleaching system of said method comprises: a) at least about 0.1%, preferably from about 1% to about 75%, by weight, of a peroxygen bleaching compound capable of yielding hydrogen peroxide in an aqueous liquor; and b) at least about 0.1%. preferably from about 0.1% to about 50%, by weight, of a bleach activator selected from the group consisting of:

>)

O O O O

II II II II R¹-C--N— R2-C— L. R1— -C— R2-C— L

I I

R5 R5 or mixtures thereof, wherein R is an alkyl, aryl, or alkaryl group

2 containing from about I to about 14 carbon atoms, R is an alkylene, arylene or alkaryiene group containing from about 1 to about 14 carbon atoms, R is H or an alkyl, aryl, or alkaryl group containing from about 1 to about 10 carbon atoms, and L is a leaving group; H)

wherein R. is H, alkyl, alkaryl, aryl, aralkyl, and wherein R^ R-, R₄, and R- may be the same or different substituents selected from H, halogen, alkyl, alkenyl, aryl, hydroxyl, alkoxyl, amino, alkylamino, COORg (wherein R₆ is H or an alkyl group) and carbonyl functions; and iii) mixtures of i) and ii).

Preferably the molar ratio of hydrogen peroxide yielded by a) to bleach aαivator b) is greater than about 1.0. Most preferably, the molar ratio of hydrogen peroxide yielded by a) to bleach activator b) is at least about 1.5.

The invention also encompasses laundry compositions in granular, paste, liquid, or bar form which comprise the aforesaid bleaching system together with detersive ingredients which are present in the composition at the levels indicated hereinafter. Preferred bleach activators of type b)i) are those wherein R is an alkyl

2 group containing from about 6 to about 12 carbon atoms, R contains from about 1 to about 8 carbon atoms, and R is H or methyl. Particularly preferred bleach aαivators of type b)i) are those of the above general formulas wherein,

R 1 is an alkyl group containing from about 7 to about 10 carbon atoms and R 2 contains from about 4 to 5 carbon atoms.

Preferred bleach aαivators of type b)ii) are those wherein R-, R-,, R₄. and R are H and R . is a phenyl group.

The peroxygen bleaching compound can be any peroxide source and is preferably a member selected from the group consisting of sodium perborate monohydrate, sodium perborate tetrahydrate, sodium percarbonate, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate, sodium peroxide and mixtures thereof. Highly preferred peroxygen bleaching compounds are selected from the group consisting of sodium perborate monohydrate, sodium perborate tetrahydrate, sodium percarbonate and mixtures thereof. The most highly preferred peroxygen bleaching compound is sodium percarbonate The bleach aαivators herein can also be used in combination with rubber-safe, hydrophiiic aαivators such as TAED, typically at weight ratios of amido-derived aαivators:TAED in the range of 1 :5 to 5: 1, preferably about 1 : 1. Another important class of rubber- safe, hydrophiiic activators comprise the N-acyl caprolaαam aαivators wherein the acyl moiety has the formula

R -CO- wherein R contains 6 or less carbon atoms Highly preferred hydrophiiic caprolaαam aαivators include formyl caproiactam, acetyl capro¬ laαam, and benzoyl caproiactam .

The method of cleaning fabrics comprises agitating fabrics in said washing machine in an aqueous liquor comprising a detergent composition which comprises at least about 300 ppm of conventional detergent ingredients, at least about 25 ppm of the bleaching compound and at least about 25 ppm of a bleach aαivator. Preferably, the liquor comprises from about 900 ppm to about 20,000 ppm of conventional detergent ingredients, from about 100 ppm to about 25,000 ppm of the bleaching compound and from about 100 ppm to about 2.500 ppm of a bleach aαivator. The method can be successfully carried out at temperatures below about 60 C but, of course, is quite effective and is still safe to rubber parts at laundry temperatures up to the boil.

The conventional detergent ingredients employed in fully formulated detergent compositions provided herein can comprise from about 1% to about

99.8%, preferably from about 5% to about 80%. of a detersive surfactant Optionally, detergent compositions can comprise from about 5% to about 80% of a detersive builder Other optional detergent ingredients are also encompassed by the fully-formulated detergent/bleach compositions provided by this invention

All percentages, ratios, and proportions are by weight, unless otherwise specified. All documents cited are incorporated herein by reference. DETAILED DESCRIPTION OF THE INVENTION The invention relates to a method for cleaning fabrics in automatic washing machines having parts made of natural rubber which is susceptible to oxidative degradation. The bleaching system used in this invention is safe to natural rubber machine pans and to other natural rubber articles which are exposed to the bleaching system, including fabrics containing natural rubber and natural rubber elastic materials. The bleaching system employed in the present invention provides effeαive and efficient surface bleaching of fabrics which thereby removes stains and or soils, including "dingy" soils, from the fabrics. Dingy soils are soils that build up on fabrics after numerous cycles of usage and washing and, thus, eventually cause white fabrics to have a gray or yellow tint. These soils tend to be a blend of paniculate and greasy materials. The removal of this type of soil is sometimes referred to as "dingy fabric clean up".

The bleaching systems and aαivators herein afford additional advantages in that, unexpeαedly, they are safer to fabrics and cause less color damage than other aαivators when used in the manner provided by this invention. The bleaching mechanism and, in particular, the surface bleaching mechanism are not completely understood. However, it is generally believed that the bleach aαivator undergoes nucleophilic attack by a perhydroxide anion, which is generated from the hydrogen peroxide evolved by the peroxygen bleach, to form a peroxycarboxylic acid. This reaction is commonly referred to as perhydrolysis

It is also believed, that the bleach activators within the invention can render peroxygen bleaches more efficient even at wash liquor temperatures wherein bleach aαivators are not necessary to aαivate the bleach, i.e., above about 60°C. Therefore, with bleach systems of the invention, less peroxygen bleach is required to get the same level of surface bleaching performance as is obtained with the peroxygen bleach alone.

The Bleach Aαivator

The hydrophobic bleach activators employed with this invention are amide substituted compounds of the general formulas: O 0 O 0

II II II II

Rⁱ-C-N— R2-C— L R1— N~C— R2-C— L

I I

R5 R5 or mixtures thereof, wherein R I . R 2. and R 5 are as defined hereinabove and L can be-essentially any suitable leaving group. A leaving group is any group that is displaced from the bleaching activator as a consequence of the nucleophilic attack on the bleach aαivator by the perhydroxide anion. This, the perhydrolysis reaction, results in the formation of the peroxycarboxylic acid.

Generally, for a group to be a suitable leaving group it must exert an electron attracting effeα. It should also form a stable entity so that the rate of the back reaαion is negligible. This facilitates the nucleophilic attack by the perhy¬ droxide anion.

The L group must be sufficiently reaαive for the reaction to occur within the optimum time frame (e.g., a wash cycle). However, if L is too reaαive, this activator will be difficult to stabilize for use in a bleaching composition. These charaαeristics are generally paralleled by the pKa of the conjugate acid of the leaving group, although exceptions to this convention are known. Ordinarily, leaving groups that exhibit such behavior are those in which their conjugate acid has a pKa in the range of from about 4 to about 13, preferably from about 6 to about 1 1 and most preferably from about 8 to about

I I

Preferred bleach aαivators are those of the above general formula l 1 22 55 wherein n RR ,, RR aanndd R R a arree as defined for the peroxyacid and L is seleαed from the group consisting of:

and mixtures thereof, wherein R is an alkyl, aryl, or alkaryl group containing

3 from about 1 to about 14 carbon atoms, R is an alkyl chain containing from 1

4 3 to about 8 carbon atoms, R is H or R , and Y is H or a solubilizing group.

+ + +

The prefeπed solubilizing groups are -SO M , -CO₂ M ,-SO , ^"M , -N⁺(R³)₄X^" and CK-N(R³)₃ and most preferably -SO₃ ^"M and -CO₂ ^"M⁺ wherein R is an alkyl chain containing from about 1 to about 4 carbon atoms, M is a cation which provides solubility to the bleach activator and X is an anion which provides solubility to the bleach aαivator. Preferably, M is an alkali metal, ammonium or substituted ammonium cation, with sodium and potassium being most preferred, and X is a halide, hydroxide methylsulfate or acetate anion. It should be noted that bleach activators with a leaving group that does not contain a solubilizing groups should be well dispersed in the bleaching solution in order to assist in their dissolution.

Preferred bleach aαivators are those of the above general formula wherein L is seleαed from the group consisting of:

wherein R is as defined above and Y is -SO,~M or -CO-^'M wherein M is as defined above

Another important class of bleach aαivators which provide organic peracids as described herein ring-opens as a consequence of the nucleophilic attack on the carbonyl carbon of the cyclic ring by the perhydroxide anion.

This ring-opening reaαion involves attack at the ring carbonyl by hydrogen peroxide or its anion Examples of ring-opening bleach aαivators can be found in U.S. Patent 4,966.723. Hodge et al, issued Oct. 30, 1990.

Such aαivator compounds disclosed by Hodge include the aαivators of the benzoxazin-type, having the formula:

including the substituted benzoxazins of the type

wherein R. is H, alkyl, alkaryl, aryl, aralkyl, and wherein I , K~, K., and K, may be the same or different substituents seleαed from H, halogen, alkyl, alkenyl, aryl, hydroxyl, alkoxyl, amino, alkyl-amino, COOR, (wherein R_fi is H or an alkyl group) and carbonyl functions.

A preferred aαivator of the benzoxazin-type is:

The bleach activators employed herein will comprise at least about 0.1%, preferably from about 0.1% to about 50%, more preferably from about 1% to about 30%, most preferably from about 3% to about 25%, by weight of the bleaching system or detergent composition.

When the aαivators are used, optimum surface bleaching performance is obtained with washing solutions wherein the pH of such solution is between about 8.5 and 10.5 and preferably between 9.5 and 10.5 in order to facilitate the perhydrolysis reaction Such pH can be obtained with substances commonly known as buffering agents, which are optional components of the bleaching systems herein The Peroxygen Bleaching Compound

The bleaching systems, wherein the bleach activator is used, also have as an essential component a peroxygen bleach capable of releasing hydrogen peroxide in aqueous solution.

The peroxygen bleaching systems useful herein are those capable of yielding hydrogen peroxide in an aqueous liquor. These compounds are well known in the an and include hydrogen peroxide and the alkali metal peroxides, organic peroxide bleaching compounds such as urea peroxide, and inorganic persalt bleaching compounds, such as the alkali metal perborates, percarbonates, perphosphates, and the like. Mixtures of two or more such bleaching compounds can also be used, if desired.

Preferred peroxygen bleaching compounds include sodium perborate, commercially available in the form of mono-, tri-, and tetra-hydrate, sodium percarbonate, sodium pyrophosphate peroxyhydrate, urea peroxyhydrate, and sodium peroxide. Particularly prefened are sodium perborate tetrahydrate, sodium perborate monohydrate and sodium percarbonate. Sodium percarbonate is especially preferred because it is very stable during storage and yet still dissolves very quickly in the bleaching liquor. It is believed that such rapid dissolution results in the formation of higher levels of percarboxylic acid and, thus, enhanced surface bleaching performance.

Highly preferred percarbonate can be in uncoated or coated form. The average panicle size of uncoated percarbonate ranges from about 400 to about 1200 microns, most preferably from about 400 to about 600 microns. If coated percarbonate is used, the preferred coating materials include mixtures of carbonate and sulphate, silicate, borosilicate, or fatty carboxylic acids

The peroxygen bleaching compound will comprise at least about 0.1%, preferably from about 1% to about 75%, more preferably from about 3% to about 40%, most preferably from about 3% to about 25%, by weight of the bleaching system or detergent composition.

The weight ratio of bleach aαivator to peroxygen bleaching compound in the bleaching system ranges form about 2:1 to about 1 :5. In preferred embodiments, the ratio ranges from about 1 : 1 to about 1 :3.

The bleach aαivator bleaching compound systems herein are useful per se as bleaches However, such bleaching systems are especially useful in compositions which can comprise various detersive adjuncts such as sur- faαants, builders, enzymes, and the like as disclosed hereinafter. Detersive Surfaαant

The amount of detersive surfaαant included in the fully-formulated detergent compositions afforded by the present invention can vary from about

1% to about 99.8% by weight of detergent composition depending upon the particular surfaαants used and the effects desired. Preferably, the detersive surfactants comprise from about 5% to about 80% by weight of the composition. The detersive surfaαant can be nonionic, anionic, ampholytic, zwitterionic. or cationic. Mixtures of these surfactants can also be used. Prefened detergent compositions comprise anionic detersive surfactants or mixtures of anionic surfaαants with other surfaαants, especially nonionic surfaαants.

Nonlimiting examples of surfaαants useful herein include the conventional C . , -C . « alkyl benzene sulfonates and primary, secondary, and random alkyl sulfates, the C_jQ-C.g alkyl alkoxy sulfates, the C,_Q-C,g alkyl polyglycosides and their conesponding sulfated polyglycosides, ,2-C, _g alpha-sulfonated fatty acid esters, C,₂-C,g alkyl and alkyl phenol alkoxylates (especially ethoxylates and mixed ethoxy/propoxy), _{j ^}-C. g betaines and sulfobetaines ("sultaines"), C._Q-C. g amine oxides, and the like. Other conven¬ tional useful surfaαants are listed in standard texts.

One particular class of adjunα nonionic surfactants especially useful herein comprises the polyhydroxy fatty acid amides of the formula:

wherein: R is H. Cj-Cg hydrocarbyl, 2-hydroxyethyl, 2-hydroxypropyl, or a mixture thereof, preferably C.-C, alkyl, more preferably C. or C- alkyl, most preferably C. alkyl (i.e.. methyl), and R is a C→-C^ hydrocarbyl moiety, preferably straight chain C--.-C._Q alkyl or alkenyl, more preferably straight chain Cg-C.→, alkyl or alkenyl, most preferably straight chain C, ,-C.g alkyl or alkenyl, or mixture thereof, and Z is a potyhydroxyhydrocarbyl moiety having a linear hydrocarbyl chain with at least 2 (in the case of glyceraldehyde) or at least 3 hydroxyls (in the case of other reducing sugars) directly connected to the chain, or an alkoxylated derivative (preferably ethoxylated or propoxylated) thereof. Z preferably will be derived from a reducing sugar in a reductive amination reaction, more preferably Z is a glycityl moiety. Suitable reducing sugars include glucose, fruαose, maltose, lactose, galactose, mannose, and xylose, as well as glyceraldehyde. As raw materials, high dextrose corn syrup, high fructose corn syrup, and high maltose corn syrup can be utilized as well as the individual sugars listed above. These corn syrups may yield a mix of sugar components for Z. It should be understood that it is by no means intended to exclude other suitable raw materials. Z preferably will be selected from the group consisting of -CH₂-(CHOH)_n-CH₂OH, -CH(CH₂OH)-(CHOH)_n .- -CH₂OH, -CH₂-(CHOH)₂(CHOR^,)(CHOH)-CH₂OH, where n is an integer from 1 to 5, inclusive, and R' is H or a cyclic mono- or poly- saccharide, and alkoxylated derivatives thereof. Most prefened are glycityls wherein n is 4, particularly -CH^CHOH^-O^OH.

In Formula (I), R can be, for example, N-methyl, N-ethyl, N-propyl,

N-isopropyl, N-butyl, N-isobutyl, N-2-hydroxy ethyl, or N-2-hydroxy propyl. For highest sudsing, R is preferably methyl or hydroxyalkyl. If lower sudsing is desired, R is preferably C₂-Cg alkyl, especially n-propyl, iso-propyl, n-butyl, iso-butyl, pentyl, hexyl and 2-ethyI hexyl. 2 R -CO-N^**- can be, for example, cocamide, stearamide, oleamide, lauramide, myristamide, capricamide, palmitamide, tallowamide, etc. Detersive Builders

Optional detergent ingredients employed in the present invention contain inorganic and/or organic detersive builders to assist in mineral hardness control. If used, these builders comprise from about 5% to about 80% by weight of the detergent compositions. Inorganic detersive builders include, but are not limited to, the alkali metal, ammonium and alkanolammonium salts of polyphosphates (exemplified by the tripolyphosphates, pyrophosphates, and glassy polymeric meta- phosphates), phosphonates. phytic acid, silicates, carbonates (including bicarbonates and sesquicarbonates), sulphates, and aluminosilicates. However, non-phosphate builders are required in some locales.

Examples of silicate builders are the alkali metal silicates, particularly those having a SiO^Na-O ratio in the range 1.6.1 to 3.2: 1 and layered silicates, such as the layered sodium silicates described in U.S. Patent 4,664,839, issued May 12. 1987 to H. P. Rieck, available from Hoechst under the trademark "S S", SKS-6 is an especially prefened layered silicate builder.

Carbonate builders, especially a finely ground calcium carbonate with

2 surface area greater than 10 m /g, are prefened builders that can be used in granular compositions The density of such alkali metal carbonate built detergents can be in the range of 450-850 g 1 with the moisture content preferably below 4%.

Examples of carbonate builders are the alkaline earth and alkali metal carbonates as disclosed in German Patent Application No. 2,321,001 published on November 15, 1973.

Aluminosilicate builders are especially useful in the present invention. Prefened aluminosilicates are zeolite builders which have the formula:

Na_z[(AlO₂)_z (SiO₂)_y] xH₂O wherein z and y are integers of at least 6, the molar ratio of z to y is in the range from 1.0 to about 0.5, and x is an integer from about 15 to about 264.

Useful aluminosilicate ion exchange materials are commercially available These aluminosilicates can be crystalline or amorphous in structure and can be naturally-occurring aluminosilicates or synthetically derived.

Mαhods for producing aluminosilicate ion exchange materials are disclosed in U.S Patent 3,985,669, Krummel, et al, issued Oαober 12, 1976, and U.S. Patent 4,605,509, Corkill, et al, issued Aug. 12, 1986. Prefened synthetic crystalline aluminosilicate ion exchange materials useful herein are available under the designations Zeolite A, Zeolite P (B), (including those disclosed in

EPO 384,070), and Zeolite X. Preferably, the aluminosilicate has a particle size of about 0.1-10 microns in diameter

Organic dαersive builders suitable for the purposes of the present invention include, but are not restriαed to, a wide variety of polycarboxylate compounds, such as ether polycarboxylates, including oxydisuccinate, as disclosed in Berg, U.S Patent 3,128,287, issued April 7, 1964, and Lamberti et al, U.S. Patent 3.635,830, issued Januaiy 18, 1972. See also "TMS TDS" builders of U.S. Patent 4.663.071. issued to Bush et al, on May 5, 1987.

Other useful detersive builders include the ether hydroxypolycar- boxylates, copolymers of maleic anhydride with ethylene or vinyl methyl ether,

1, 3, 5-trihydroxy benzene-2. 4, 6-trisulphonic acid, and carboxymethyl- oxysuccinic acid, the various alkali metal, ammonium and substituted ammonium salts of polyacetic acids such as ethylenediamine tetraacetic acid and nitrilotriacetic acid, as well as polycarboxylates such as mellitic acid, succinic acid, oxydisuccinic acid, polymaieic acid, benzene 1,3,5-tricarboxylic acid, carboxymethyloxysuccinic acid, and soluble salts thereof.

Citrate builders, e g . citric acid and soluble salts thereof (particularly sodium salt), are prefened polycarboxylate builders that can also be used in granular compositions, especially in combination with zeolite and/or layered silicate builders.

Also suitable in the detergent compositions of the present invention are the 3,3-dicarboxy-4-oxa-l,6-hexanedioates and the related compounds disclosed in U.S. Patent 4,566,984, Bush, issued January 28, 1986.

In situations where phosphorus-based builders can be used, and especially in the formulation of bars used for hand-laundering operations, the various alkali metal phosphates such as the well-known sodium tripolyphosphates, sodium pyrophosphate and sodium orthophosphate can be used. Phosphonate builders such as ethane- l-hydroxy-l,l-diphosphonate and other known phosphonates (see, for example, U.S. Patents 3,159,581; 3,213,030; 3,422,021; 3,400,148 and 3,422,137) can also be used Optional Detersive Adiunαs

As a preferred embodiment, the conventional detergent ingredients employed herein can be seleαed from typical detergent composition components such as detersive surfaαants and detersive builders. Optionally, the detergent ingredients can include one or more other detersive adjunαs or other materials for assisting or enhancing cleaning performance, treatment of the substrate to be cleaned, or to modify the aesthetics of the detergent composition. Usual detersive adjunαs of detergent compositions include the- ingredients set forth in U.S. Pat. No. 3,936,537, Baskerville et al. Adjunαs which can also be included in detergent compositions employed in the present invention, in their conventional art-established levels for use (generally from

0% to about 20% of the detergent ingredients, preferably from about 0.5% to about 10%), include enzymes, especially proteases, lipases, and celluiases, color speckles, suds boosters, suds suppressors, antitarnish and/or anticonosion agents, soil-suspending agents, soil release agents, dyes, fillers, optical brighteners. germicides, alkalinity sources, hydrotropes, antioxidants, enzyme stabilizing agents, perfumes, solvents, solubilizing agents, clay soil removal/anti-redeposition agents, polymeric dispersing agents, processing aids, fabric softening components, static control agents, etc.

Bleach systems optionally, but preferably, will also comprise a chelant which not only enhances bleach stability by scavenging heavy metal ions which tend to decompose bleaches, but also assists in the removal of polyphenolic stains such as tea stains, and the like. Various chelants, including the amino- phosphonates, available as DEQUEST from Monsanto, the nitrilotriacetates, the hydroxyethyl-ethylenediamine triacetates, and the like, are known for such use. Preferred biodegradable, non-phosphorus chelants include ethylene- diamine disuccinate ("EDDS"; see U.S. Patent 4,704,233, Hartman and Perkins), ethylenediamine-N.NT-diglutamate (EDDG) and 2-hydroxypro- pylenediamine-N.N'-disucciπate (HPDDS) compounds. Such chelants can be used in their alkali or alkaline earth metal salts, typically at levels from about 0.1% to about 10% of the present compositions. Optionally, the detergent compositions employed herein can comprise, in addition to the bleaching system of the present invention, one or more other conventional bleaching agents, aαivators, or stabilizers which do not reaα with or otherwise harm natural rubber. In general, the formulator will ensure that the bleach compounds used are compatible with the detergent formulation.

Conventional tests, such as tests of bleach aαivity on storage in the presence of the separate or fully-formulated ingredients, can be used for this purpose

Specific examples of optional bleach aαivators for incorporation in this invention include tetraacetyl ethylene diamine (TAED) and N-acyl caprolaαams. Highly prefened N-acyl caprolactams include benzoyl caprolaαam and those wherein the acyl moieties have the formula R -CO- wherein R is H or an alkyl, aryl, arkaryl, or alkoxyaryl group containing from 1 to 12 carbon atoms, preferably 1 to 6 carbon atoms.

Such bleaching compounds and agents can be optionally included in detergent compositions in their conventional art-established levels of use, generally from 0% to about 15%, by weight of detergent composition.

Bleaching aαivators of the invention are especially useful in conventional laundry detergent compositions such as those typically found in granular detergents or laundry bars. U.S. Patent 3,178,370, Okenfuss, issued April 13, 1965. describes laundry detergent bars and processes for making them. Philippine Patent 13,778. Anderson, issued Sept. 23, 1980, describes synthetic detergent laundry bars Methods for making laundry detergent bars by various extrusion methods are well known in the art.

The following examples are given to further illustrate the present invention, but are not intended to be limiting thereof.

EXAMPLE I Synthesis of (6-Nonanamidocaproyi)oxybenzenesulfonate (NACA-OBS).

6-Nonanamidocaproic Acid fNACA) - The reaction is carried out in a 12L 3 -necked flask equipped with a thermometer, addition funnel and mechanical stiner To a solution made from 212g (5.3 moles) of sodium hydroxide and 6L of water (cooled to room temperature) is added 694.3g (5.3 moles) of 6-aminocaproic acid. This mixture is cooled to 10°C and a solution of 694.3g (5.3 moles) of nonanoyl chloride in IL of ether is added in a slow stream (about 2.5 hours) keeping the temperature at 10-15°C. During the addition, and subsequently until acidification, the reaction is maintained at pH

1 1-12 by periodic addition of 50% NaOH. After the addition is complete, the reaαion is stined for another 2 hours at 10 C and allowed to come to room temperature before acidification to pH 1 with cone. HC1. The precipitated produα is vacuum filtered, the filter cake is washed twice with 8L portions of water and the produα air dried overnight. It is then suspended in 3L of hexane, filtered and washed with an additional 3L of hexane. The produα is then vacuum dried overnight (50°C, 1 mm) to give 1354 g (94%) of NACA.

Acid Chloride (NACA-C1) - The reaαion is carried out in a 5L, 3-necked flask equipped with an addition funnel, mechanical stiner and argon sweep. To a suspension of 542g (2.0 moles) of NACA in 2L of toluene is added (in a slow stream over 30 minutes) 476 g (4.0 moles) of thionyl chloride.

This mixture is stined at room temperature for four hours during which time the solids dissolve. The solution is partially evaporated (30°C, 10 mm) to remove any excess thionyl chloride leaving 905g of NACA-Cl/toluene solution (contains approximately 2 moles of NACA-C1). An IR spectrum confirms conversion of COOH to COCI.

(6-NonanamidocaprovDoxybcnzenesulfonate (NACA-OBS) - The reaαor is a 12L, 3-necked flask equipped with a condenser, mechanical stiner and static argon supply. To the reactor are added 647g of the above NACA-Cl toluene solution (1 43 moles), 6L of toluene and 310.8g (1.43 moles) of disodium p-phenolsulfonate (disodium p-phenolsulfonate is previously prepared and dried in a vacuum oven before use (1 10°C, 0.1mm hg, 18 hours). This mixture is refluxed for 18 hours. After cooling to room temperature, the produα is colleαed on a Buchner funnel and dried to give 725g of crude solids. The crude is taken up in 7L of refluxing 87: 13 (v,v) methanol/water, filtered hot and allowed to recrystallize at room temperature.

The resulting precipitate is filtered and vacuum dried (50°C, 0.1 mm) for 18 hours to give 410g (64% based on NACA) of light tan product. A trace of unreaαed phenolsulfonate is indicated by the small doublets at 6.75 and 7.55 ppm in the H spectrum Otherwise, the spectra are consistent with expected structure and no other impurities are evident.

EXAMPLE II A granular detergent compositions is prepared comprising the following ingredients.

Component Weight % C.₂ linear alkyl benzene sulfonate 22

Phosphate (as sodium tripolyphosphate) 30 Sodium carbonate 14

Sodium silicate 3

Sodium percarbonate 5

Ethylenediamine disuccinate chelant (EDDS) 0.4 Sodium sulfate 5.5

(6-Nonanamidocaproyl)oxybenzenesulfonate 5

Minors, filler* and water Balance to 100%

•Can be seleαed from convenient materials such as CaCO^, talc, clay, silicates, and the like. In testing the bleaching performance and effeα on natural rubber washing machine parts, the following test method is used:

Aqueous crutcher mixes of heat and alkali stable components of the detergent compositions are prepared and spray-dried. The other ingredients are admixed so that the composition contains the ingredients tabulated at the levels shown.

The detergent granules with bleach activator are added together with 5 lb. (2.3 kg) of previously laundered fabrics, including natural rubber articles such as elastic fabrics, to an automatic washing machine equipped with a natural rubber sump hose. Aαual weights of detergent and bleach activator are taken to provide a 950 ppm concentration of the former and 50 ppm concentration of the latter in the 17 gallon (65 I) water-fill machine. The water used has 7 grains gallon hardness and a pH of 7 to 7.5 prior to (about 9 to about 10.5 after) addition of the detergent and bleaching system.

The fabrics are laundered at 35°C (95°F) for a full cycle (12 min.) and rinsed at 2I°C (70°F) The laundering method is repeated for 2,000 wash cycles without rupture of, or significant damage to, the natural rubber parts, or damage to the natural rubber articles.

EXAMPLE III A granular detergent composition is prepared comprising the following ingredients.

Component Weight %

Anionic alkyl sulfate 7

Nonionic surfaαant 5

Zeolite (0.1-10 micron) 10 Trisodium citrate 2

S S-6 silicate builder 10 Acrylate maleate polymer 4

(6-Nonanamidocaproyl)oxybenzenesulfonate 5

Sodium percarbonate 15

Sodium carbonate 5 Ethylenediamine disuccinate chelant (EDDS) 0.4

Suds suppressor 2

Enzymes* 1.5

Soil release agent 0.2

Minors, filler** and water Balance to 100% * 1.1.1 mixture of protease, lipase, and cellulase.

••Can be seleαed from convenient materials such as CaCO^, talc, clay, silicates, and the like.

In testing the bleaching performance and effect on natural rubber washing machine parts, the following test method is used: Aqueous crutcher mixes of heat and alkali stable components of the detergent composition are prepared and spray-dried. The other ingredients are admixed so that the composition contains the ingredients tabulated at the levels shown.

The detergent granules with bleach activator are added via the dispensing drawer together with 5 lb. (2.3 kg) of previously laundered fabrics to an automatic washing machine equipped with a natural rubber sump hose. Actual weights of detergent and bleach aαivator are taken to provide a 8,000 ppm concentration of the former and 400 ppm concentration of the latter in the 17 I water-fill machine The water used has 7 grains gallon hardness and a pH of 7 to 7.5 prior to (about 9 to about 10.5 after) addition of the detergent and bleaching system

The fabrics are laundered at 40°C (104°F) for a full cycle (40 min.) and rinsed at 2I°C (70°F) The laundering method is repeated for 2,000 wash cycles without rupture of. or significant damage to, the natural rubber parts. EXAMP E IV

A detergent composition is prepared by a procedure identical to that of Example III, with the single exception that an equivalent amount of nonanoyloxybenzenesulfonate (NOBS) is substituted for the (6-Nonanamido- caproyl)oxybenzenesulfonate bleach aαivator in Example III. The laundering method of Example III is repeated for 1200 cycles at about which time the natural rubber sump hose ruptures. EXAMPLE V A detergent composition is prepared by a procedure identical to that of Example III, with the single exception that an equivalent amount of benzoyloxybenzenesulfonate (BOBS) is substituted for the (6-Nonanamido- caproyl)oxybenzenesuIfonate bleach aαivator in Example III The laundering method of Example III is repeated for 1200 cycles at about which time the natural rubber sump hose ruptures.

EXAMPLE VI

A dαergent composition is prepared by a procedure identical to that of Example III, with the exceptions that 15% of a 1 : 1 mixture of tetraacetyl ethylene diamine and (6-NonanamidocaproyI)oxybenzenesulfonate bleach aαivator is substituted for the bleach aαivator in Example III and the amount of sodium percarbonate is 30%. The laundering method of Example III is repeated for 2,000 cycles without rupture of, or significant damage to, the natural rubber parts

EXAMPLE VII A detergent composition is prepared by a procedure identical to that of Example III, with the single exception that 15% of a 1: 1 mixture of benzoyl caproiactam and (6-Nonanamidocaproyl)oxybenzenesulfonate is substituted for the bleach aαivator in Example III and the amount of sodium percarbonate is

30% The laundering method of Example III is repeated for 2,000 cycles without rupture of, or significant damage to, the natural rubber parts.

EXAMPLE VIH A detergent composition is prepared by a procedure identical to that of Example III. with an equivalent amount of a benzoxazin-type bleaching activator, as disclosed in U S Patent 4,966,723, Hodge et al, is substituted for the bleach activator in Example III The laundering method of Example III is repeated for 2,000 cycles without rupture of, or significant damage to, the natural rubber parts EXAMPLE IX

A detergent composition is prepared by a procedure identical to that of

Example III, with the single exception that 6% of a 1: 1 mixture of (6-Nonan- amidocaproyl)oxybenzenesulfonate and a benzoxazin-type bleaching activator, as disclosed in U S Patent 4,966,723, Hodge et al, is substituted for the bleach aαivator in Example III The laundering method of Example III is repeated for 2,000 cycles without rupture of, or significant damage to, the natural rubber parts.

EXAMPLE X A detergent composition is prepared by a procedure identical to that of Example III, with the single exception that 6% of a 1 : 1 mixture of tetraacetyl ethylene diamine and a benzoxazin-type bleaching aαivator, as disclosed in U.S. Patent 4,966,723, Hodge et al, is substituted for the bleach activator in Example III. The laundering method of Example III is repeated for 2,000 cycles without rupture of, or significant damage to, the natural rubber parts. M^ho of Processing the Bleach Aαivators

The bleach aαivators may be processed with a range of organic and inorganic substances to achieve a rapid dispersion in the bleaching liquor and to insure good stability in the detergent composition. The bleach aαivators are preferably employed in paniculate form. An example of prefened caprolaαam bleach aαivator particles is an agglomerate of about 65%, by weight, bεnzoyl caprolaαam; about 7% of a builder, such as aluminium silicate; about 15% sodium carbonate; about 9% dispersant, such as a polyacrylate polymer; and about 4% of a solubilizing agent, such as a linear alkyl sulfonate. Another example of a prefened caprolaαam bleach aαivator particle is an agglomerate of about 80% to about

85%, by weight, benzoyl caprolaαam and about 15% to about 20% of a binder, such as tallow alcohol ethoxylates, preferably TAE25.

An example of a preferred amido-derived bleach aαivator particle comprises a 1 :1 : 1 mixture of (6-oαanamidocaproyI)oxybenzenesulfonate, (6- decanamidocaproyl)oxybenzenesulfonate, and citric acid powder. The mixture is intimately mixed in a food mixer for 5-10 minutes. To the resultant mixture is added tallow alcohol ethoxylate (TAE25) nonionic surfactant at 50° C until granules are formed Typically successful granulations are achieved with a ratio of bleach aαivator/citric acid solid mixtures.nonionic binding agent of 3.5: 1. The resultant granules, ellipsodial and spherical in shape, are white and free flowing.

A typical particle composition is about 40% to about 60%, preferably about 55%, by weight, of the bleach activator or mixture of bleach activators; about 20% to about 40%, preferably about 25%, by weight, of citric acid; and about 15% to about 30%, preferably about 20%, by weight of TAE25 binding agent. Alternatively, a 2:1 mixture of (6-decanamidocaproyl)oxyben- zenesulfonate and citric acid powder may be used. In this case, the composition on the granule is 55% bleach aαivator, 25% citric acid, and 20% TAE25 binding agent. Other prefened organic binding agents include anionic surfaαants (Cj2 linear alkyl benzene sulfonates), polyethylene glycols, and TAE50.

The particle size of the resulting granules may be varied according to the desired performance/stability. Fine particles (<250 um) show improved solubility, though coarse particles (>1 180 um) are more stable at high temperatures moist environment. A typically prefened particle size range is 250-1 180 um; particles conforming to this specification show excellent stability and solubility.

EXAMPLE XI

A laundry bar suitable for hand-washing soiled fabrics is prepared by standard extrusion processes and comprises the following:

Component Weight %

C.. linear alkyl benzene sulfonate 30

Phosphate (as sodium tripolyphosphate) 7

Sodium carbonate 25

Sodium pyrophosphate 7

Coconut monoethanolamide 2

Zeolite A (0.1-10 micron) 5

Carboxymethylcellulose 0.2

Ethylenediamine disuccinate chelant (EDDS) 0.4

Polyacrylate (m.w. 1400) 0.2

(6-Nonanamidocaproyl)oxybenzenesulfonate 5

Sodium percarbonate* 5

Brightener, perfume 0.2

Protease 0.3

CaSO '4, 1 MgSO₄ 1

Water 4

Filler* * Balance to 100%

•Average particle size of 400 to 1200 microns

**Can be seleαed from convenient materials such as CaCO,, talc, clay, silicates, and the like The detergent laundry bars are processed in conventional soap or detergent bar making equipment as commonly used in the art Testing is conduαed following the testing methods in Example II. The laundering method is repeated for 2,000 wash cycles without rupture of, or significant damage to, the natural rubber parts, or damage to the natural rubber articles.

Claims

What is claimed is:

1. A bleaching system characterized in that it comprises: a) a bleach aαivator seleαed from the following:

1 to 14 1 to 14

carbon atoms, R is H or an alkyl, aryl, or alkaryl group containing from 1 to 10 carbon atoms, and L is a leaving group; and

wherein R, is H, alkyl, alkaryl, aryl, aralkyl, and wherein l , R~, R,, and R₅ may be the same or different substituents seleαed from H, halogen, alkyl, alkenyl, aryl, hydroxyl, alkoxyl, a ino, alkylamino, -COORg, wherein Rg is H or an alkyl group and carbonyl funαions; b) a nonamido-derived hydrophiiic bleach activator; and c) a peroxygen bleaching compound, preferably seleαed from the group consisting of perborate salts and percarbonate salts..

2. A composition according to Claim 1 wherein R is an alkyl group containing from

2 7 to 10 carbon atoms, R contains from 4 to 5 carbon atoms, and L is seleαed from the group consisting of:

wherein R^ is an alkyl chain containing from 1 to 8 carbon atoms, Y is -SO3-M ^" or -CO2^*M wherein M is sodium or potassium.

3. A composition according to Claim 1 wherein the hydrophiiic bleach activator is selected from the group consisting of benzoyl caproiactam and tetraacetyl ethylene diamine.

4. A composition according to Claim 1 wherein the bleach activator is

5. A composition according to Claim 1 which additionally comprises a chelant, preferably an ethylenediamine disuccinate chelant or an aminophosphonate chelant.

6. A composition according to Claim 1 in the form of a laundry detergent which additionally comprises detersive surfaαants, builders and detersive adjunα ingredients.

7. A method for cleaning fabrics in an automatic washing machine having parts made of natural rubber which is susceptible to oxidative degradation, said method comprising agitating said fabrics in said machine in an aqueous liquor comprising a bleaching system according to Claim 1, such that said natural rubber parts of said machine are substantially undamaged by the bleaching system.

8. A method according to Claim 7 wherein the bleaching system comprises a bleach aαivator which reacts in said aqueous liquor to yield a peroxyacid of the general formulae:

wherein R is an alkyl, aryl, or alkaryl group containing from 1 to 14 carbon atoms, R is an alkylene, arylene or alkaryiene group containing from 1 to 14 carbon atoms, and R is H or an alkyl, aryl, or alkaryl group containing from 1 to 10 carbon atoms.

9. A method according to Claim 7 wherein said aqueous liquor further comprises conventional detergent ingredients; said bleaching system comprising: a) at least 0.1%, by weight, of a peroxygen bleaching compound capable of yielding hydrogen peroxide in an aqueous liquor; said peroxygen bleaching compound is preferably selected from the group consisting of sodium perborate monohydrate, sodium percarbonate, sodium perborate tetrahydrate, sodium pyrophosphate peroxy-hydrate, urea peroxyhydrate, sodium peroxide and mixtures thereof; and b) at least 0.1%, by weight, of a bleach aαivator seleαed from the group consisting of: i)

or mixtures thereof, wherein R is an alkyl, aryl, or alkaryl group

2 containing from 1 to 14 carbon atoms, R is an alkylene, arylene or alkaryiene group containing from 1 to 14 carbon atoms, R is H or an alkyl, aryl, or alkaryl group containing from 1 to 10 carbon atoms, and L is a leaving group selected from the following:

and mixtures thereof, wherein R is an alkyl, aryl, or alkaryl group containing from 1 to 14 carbon atoms, R is an alkyl chain containing from 1 to 8 carbon atoms, R 4 is H or R 3 , and Y is H or a solubilizing group; and ϋ)

wherein R. is H, alkyl, alkaryl, aryl, aralkyl, and wherein R_y, K*, K., and R^ may be the same or diflferent substituents seleαed from H, halogen, alkyl, alkenyl, aryl, hydroxyl, alkoxyl, amino, alkylamino, -COOR,, wherein Rg is H or an alkyl group, and carbonyl funαions, such that the molar ratio of hydrogen peroxide yielded by a) to bleach activator b) is greater than 1.0.

10. A method according to Claim 9 wherein R is an alkyl group containing from 6 to

2 12, preferably from 7 to 10, carbon atoms, R contains from 1 to 8, preferably from 4 to

5, carbon atoms, and R is H or methyl.

11. A method according to Claim 10 wherein Y is selected from the group consisting of: -SO3"M⁺, -CO2"M⁺, -SO4-M+ -N⁺(R³)4X- and 0<-N(R³)3 and mixtures thereof wherein R³ is an alkyl chain containing from 1 to 4 carbon atoms, M is a cation which provides solubility to the bleach aαivator and X is an anion which provides solubility to the bleach aαivator.

12. A method according to Claim 11 wherein L is seleαed from the group consisting of:

wherein R³ is an alkyl chain containing from 1 to 8 carbon atoms, Y is -SO3-M+ or -CO2-M+ wherein M is sodium or potassium.

13. A method according to Claim 9 wherein the bleach aαivator is

14. A method according to Claim 9 wherein the conventional detergent ingredients comprise from 5% to 80%, by weight, of a detersive surfactant, from 5% to 80%, by weight, of a detersive builder and from 0% to 20%, by weight, of conventional detersive adjunα materials.

15. A composition according to Claim 1 wherein said bleach aαivators are in particulate form.

16. A composition according to Claim 16 wherein said bleach activator particle comprises from 40% to 60%, by weight, of a 1:1 mixture of (6- octanaπύdocaproyQoxybenzenesulfonate and (6-decanamidocaproyl)- oxybenzenesulfonate; from 20% to 40%, by weight, citric acid; and from 15% to 30%, by weight, tallow alcohol ethoxylate nonionic surfaαant.

17. A composition according to Claim 16 wherein said bleach activator particle comprises 65% benzoyl caproiactam, 7% aluminium silicate, 15% sodium carbonate, 9% potyacrylate poymer, and 4% linear alkyl sulfonate.

18. A composition according to Claim 16 wherein said particle comprises 80% benzoyl caproiactam and 20% tallow alcohol ethoxylate nonionic surfactant