EP0051508B1 - Bleaching compositions - Google Patents

Description

The present invention relates to bleaching compositions.

Bleaching agents that generate liquid active oxygen, such as hydrogen peroxide, or solids, such as persalts, such as sodium perborate, do not decompose at a rate fast enough to be compatible with a bleaching process, except at a temperature above 70 ° C.

However, household detergents at moderate temperature are a subject on the agenda linked to the problem of energy saving. In addition, the implementation, in a washing machine, of an effective bleaching process at a temperature below 60 ° C, has a number of advantages. In the case of cotton fabrics, there is less degradation of the cellulose, and consequently a reduction in the wear of the linen. Ob observes improved whitening of synthetic fabrics or textile articles treated with a finish ensuring their wrinkle-resistant and permanent ironing, and which cannot withstand a temperature above 60 ° C. Bleaching at moderate temperature reduces the risk of attack of the dyes or their transfer from one fabric to another. This type of bleaching is also in favor of the fight against pollution by lowering the polyphosphates content of waste water. It is known that, in general, washing powders contain up to 40% of polyphosphates whose role is the sequestration of calcium Ca ⁺⁺ from hard waters to avoid encrustation in textile fibers. However, this encrustation is due to the precipitation of calcium carbonate; however, if the temperature remains below 60 ° C, the rate of transformation of HC0 ₃ - into C0 ₃ ⁼ decreases and, consequently, the precipitation of calcium carbonate decreases. Also, the use of washing powders at temperatures below 60 ° C could reduce their polyphosphate content and therefore this kind of water pollution which causes the eutrophication of lakes and rivers.

A large number of molecules have been studied and proposed as activators of active oxygen generating compounds. French Patent No. 1,232,554 describes the use of organic acylamides, in particular organic acetyl amide. Among these acetylated derivatives of aromatic amines, tetracetylethylene diamine: (CH ₃ CO) ₂ N - (CH ₂ ) ₂ -N (COCH ₃ ) ₂ or TAED, mentioned in French Patent No. 1,258,675, currently enters the composition of commercial washing powders.

Also known from French Patent No. 2,340,371 is a process for activating a peroxide-based bleaching agent, in which is incorporated into an aqueous medium: a peroxide-based bleaching agent, cyanamide and / or a metal cyanamide in an amount suitable for activating the peroxide, and optionally a metal compound of group II A, and the aqueous medium is maintained in an alkaline state, optionally by incorporating a buffer therein, with the proviso that if the constituent (b) is cyanamide and if component (c) is absent, the aqueous medium is maintained at a pH greater than 7.5.

We found a new class of compounds carrying the amidine group relatively simple to manufacture, more economical in particular than that of the molecule of tetracetylethylene diamine, endowed with interesting capacities of activation of active oxygen generators.

dans laquelle B désigne un atome d'hydrogène, un halogène, un radical alkyle, aryle, alkylaryle, cycloalkyle, oxyalkyle, tel 0 - CH₃, un radical thioalkyle, tel S - CH₃, un radical acyle, tel -CO - CH₃, un radical acide minéral tel S0₃H, un radical organominéral tel CH₂PO₃H₂; R₁, R₂ et R₃ désignent un atome d'hydrogène, un radical alkyle, aryle, alkylaryle, cycloalkyle ou acyle, tel acétyle -CO-CH₃.This class of compounds which improves the efficiency, at ordinary or moderate temperature, of liquid or solid bleaching agents, such as hydrogen peroxide, alkaline perborates such as sodium perborate and alkaline percarbonates such as sodium percarbonate, carrying the group amidine, is represented by the general formula

in which B denotes a hydrogen atom, a halogen, an alkyl, aryl, alkylaryl, cycloalkyl or oxyalkyl radical, such as 0 - CH ₃ , a thioalkyl radical, such as S - CH ₃ , an acyl radical, such as -CO - CH ₃ , an inorganic acid radical such as S0 ₃ H, an organomineral radical such as CH ₂ PO ₃ H ₂ ; R ₁ , R ₂ and R ₃ denote a hydrogen atom, an alkyl, aryl, alkylaryl, cycloalkyl or acyl radical, such as acetyl -CO-CH ₃ .

Amidines are generally strong, stable bases in the form of a mineral or organic acid salt, in formula I, HA symbolizes a mineral or organic monoacid; H represents the proton and A a monovalent anion; optionally a polyacid can be linked to one or more amidine molecules.

dans laquelle X est un halogène, notamment le chlore et le brome, HA désignant un acide minéral ou organique, constituent un groupe d'acitvateurs particulièrement intéressants du peroxyde d'hydrogène ou des composés solides libérant du peroxyde d'hydrogène à température modérée.Haloformamidines in free form or in an acid salt, represented by the formula:

in which X is a halogen, in particular chlorine and bromine, HA denoting a mineral or organic acid, constitute a group of particularly advantageous activators of hydrogen peroxide or solid compounds releasing hydrogen peroxide at moderate temperature.

est dotée d'une grande capacité d'activation; elle peut se présenter sous forme de chlorhydrate ou de nitrate, mais on note l'intérêt pratique des dérivés sulfurique et phosphorique beaucoup plus stables. Ces amidines présentent l'avantage d'être plus actifs que le tétracétyléthylène diamine (TAED), plus facilement manipulables que la cyanamide CN₂H₂ et beaucoup plus solubles que la cyanamide calcique CaCN₂.Chloroformamidine

has a large activation capacity; it can be in the form of hydrochloride or nitrate, but we note the practical interest of sulfuric and phosphoric derivatives much more stable. These amidines have the advantage of being more active than tetracetylethylene diamine (TAED), more easily manipulated than cyanamide CN ₂ H ₂ and much more soluble than calcium cyanamide CaCN ₂ .

sont douées aussi d'une forte capacité d'activation; la formamidine H-C (=NH)NH₂; l'acétamidine H₃C--C(-NH)NH₂; la méthyl isothiourée CH₃S-C(=NH)-NH₂, sont aussi des activateurs du perborate. Les sels des haloformamidines peuvent être employés seuls à l'état pur ou en mélange.Other haloformamidines, in free form or salts of mineral and organic acids, such as bromoformamidine

are also endowed with a strong activation capacity; formamidine HC (= NH) NH ₂ ; acetamidine H ₃ C - C (-NH) NH ₂ ; methyl isothiourea CH ₃ SC (= NH) - NH ₂ , are also activators of perborate. The haloformamidine salts can be used alone in pure form or as a mixture.

It has been shown by French patent application No. 2,340,371 that cyanamide H ₂ N - C s N and the alkali or alkaline earth salts, are also very good bleach activators for peroxygen compounds. Because of their very low molecular weight, an efficiency equivalent to that of TAED is obtained by using, with these products, doses three times lower.

However, the use of these compounds can have serious drawbacks because, in the case of cotton fabrics, they cause a strong degradation of the cellulose fiber; moreover, as TAED does, they are relatively aggressive with regard to certain particularly fragile dyes; finally, some are relatively difficult to handle such as cyanamide H ₂ N - CN or poorly soluble in water such as its Ca ⁺⁺ or Mg ⁺⁺ salts.

Another drawback of the cyanamide function is that the activators of this class see their effectiveness greatly reduced when the bleaching bath contains as impurities cations of transition metals, in particular the cations Fe ³⁺ and C _{u2 +} .

For activators containing the amidine function, these side effects are greatly reduced if not completely canceled.

est l'activeur de la série qui allie une très bonne activité à un minimum d'effets secondaires.In particular chloroformamidine sulfate (SCF)

is the activator of the series which combines very good activity with a minimum of side effects.

It is generally accepted that haloformamidine salts, in particular chloroformamidine chloride, behave in aqueous solution like cyanamide generators; if this were the case, in bleaching at moderate temperature, the use of these salts would cause the same side effects with respect to the degradation of the cellulose. However, it has been demonstrated that these effects are greatly reduced, especially in the case of chloroformamidine sulfate.

On the other hand, it has been shown that the amidine function by itself has a certain activity. It can be concluded that the mechanism of activation of peroxidic oxygen induced by haloformamidine salts would be different from that of cyanamide, and that in this case, these products do not act as cyanamide generators. The activity of the amidine function would be increased by the substitution, on the carbon carrying the amine and imine groups, of a strongly electro-negative element such as chlorine or bromine.

• Une composition de blanchiment stable formée d'un agent de blanchiment apte à libérer de l'oxygène actif et d'une amidine représentée par la formule 1, en quantité suffisante pour ectiver ledit agent de blanchiment.

The subject of the invention is:

• A stable bleaching composition formed of a bleaching agent capable of releasing active oxygen and an amidine represented by formula 1, in an amount sufficient to activate said bleaching agent.

A stable solid bleaching composition constituted by the association of a pulverulent solid derivative and soluble in water, releasing hydrogen peroxide in aqueous alkaline solution, such as sodium perborate, sodium percarbonate, per-pyrophosphate, persilicate, urea peroxide, and all mineral or organic hydroperoxidates and an amidine from the class of compounds represented by formula 1 in an amount sufficient to activate the release of active oxygen at moderate temperature.

A stable liquid bleaching composition consisting of hydrogen peroxide and an amidine according to formula I, in an amount necessary for the activation of hydrogen peroxide at moderate temperature.

The bleaching compositions activated by an amidine can be used in the bleaching of any bleachable substance by means of a compound capable of releasing active oxygen.

The bleaching compositions according to the invention are specially suitable for household and industrial bleaching of natural, artificial and synthetic fibers at moderate temperature. In these laundering cases, the compositions of the invention are used in conjunction with detergents or detergents, such as a commercial washing powder free of bleaching agent.

Examples are given below which illustrate, without limitation, the activation properties of the amidines according to the invention.

The activation capacity of these molecules vis-à-vis hydrogen peroxide or solid compounds releasing hydrogen peroxide in alkaline aqueous solution, is demonstrated by bleaching tests at 30 and 60 ° C in a device sold under the Terg-O-Tometer brand.

• a) Dans la première, on utilise six carrés de coton de 10 cm de côté: deux sont salis par une infusion de thé, deux par une infusion de café, deux par du vin rouge; on les immerge dans un bain de lavage porté à la température de l'essai. Le bain de lavage dont le pH est compris entre 9 et 10,5 contient une poudre à laver du commerce sans agent de blanchiment, du perborate de sodium à raison de 1, 5 g/1 à titre d'agent de blanchiment et éventuellement un agent d'activation; on ajoute éventuellement du carbonate de sodium pour maintenir le pH à une valeur convenable. Le lavage sous agitation dure 40 min; après rinçage, essorage et repassage, on mesure le degré de blanc à l'aide d'un appareil commercialisé sous la marque ERELPHO.

Three test methods are used:

• a) In the first, we use six 10 cm cotton squares: two are soiled with an infusion of tea, two with an infusion of coffee, two with red wine; they are immersed in a washing bath brought to the test temperature. The washing bath whose pH is between 9 and 10.5 contains a commercial washing powder without bleaching agent, sodium perborate in an amount of 1.5 g / l as a bleaching agent and optionally a activation agent; sodium carbonate is optionally added to maintain the pH at a suitable value. The washing with stirring lasts 40 min; after rinsing, spinning and ironing, the degree of white is measured using a device sold under the brand ERELPHO.

dans laquelle

• DL : d° de blanc du tissu lavé
• DB : d° de blanc du tissu non sali
• DS : d° de blanc du tissu sali

on mesure aussi la consommation d'oxygène actif.We express the result in% average of removal of stains from wine, tea, coffee, calculated according to the formula

in which

• DL: white of the washed fabric
• DB: white number of the soiled fabric
• DS: white color of soiled fabric

the consumption of active oxygen is also measured.

• b) A second faster method was used in which six squares were used in each test. cotton soiled with an infusion of tea; after the test as described above, the degrees of white measured using a device sold under the brand Electro synthesis with a blue filter are compared; the various constituents of the mixture are dissolved in a buffer solution based on sodium hydroxide and bicarbonate.
• c) In the third method, the same dirt is used as in the first and the same buffer solution and measurement of the degree of white as in the second.

Example 1 - Amidine Function

The activation capacity of the amidine function is measured in the form of acetamidine hydrochloride according to the test protocol described except that the measurement of the whiteness is carried out with an electrosynthesis device and the result expressed in degrees of white and not as a percentage of stain removal; the results are obtained in the table below which show a significant activation effect of the amidine function at 60 ° C.

Example 2

On en déduit que, à condition d'opérer à un pHde l'ordre de 9,7, l'addition de 0,3 g de chlorhydrate de chloroformamidine est équivalente à celle de 0,6 de TAED.The percentage of stain removal obtained according to test protocol (a) is compared at 30 and 60 ° C., using chloroformamidine hydrochloride (CCF) and tetraacetyl ethylene diamine (TAED) as an activator. The results are grouped in the table below, OA = active oxygen.

It is deduced therefrom, provided that operating at a pH of the order of 9.7, the addition of 0.3 g of chloroformamidine hydrochloride is equivalent to that of 0.6 of TAED.

Example 3

With the test method (b) the degrees of whiteness on tea stains are compared with various amidines; the results are obtained from Table 2 below.

est désigné par Am.In the first column of the table above, the amidine group

is designated by Am.

It is noted that, apart from the formamidine acetate (n 6) which is not very active, all the other amidines tested are effective. This clearly highlights the activating effect of this group; this effect can be changed by substitution; the substitution of the carbonate carrying the imino and amino groups by an electronegative element such as chlorine, reinforces the activation efficiency of the molecule; this is the case with chloroformamidine.

Example 4

According to test protocol (c), the efficacy of acetamidine hydrochloride is evaluated by measuring the degree of white after washing; the results are obtained below.

The results of this test, more severe than the previous one, confirm the positive effect of the amidine function at 60 ° C.

Example 5

The activation effect of chloroformamidine sulfate (SCF) is examined using the same test protocol as in Example 2. The results are obtained from the table below.

To obtain a bleaching efficiency comparable to that obtained with 0.6 g of TAED. approximately 0.4 of SCFet should be used at 30 ° C and only 0.2 g at 60 ° C.

Example 6 Effect on Cellulose

• (dont 30 min pour monter à 90°C)
• (dont 20 min pour monter à 60°C)

A device sold under the brand "AHIBA" is used under the following conditions:

• (including 30 min to climb to 90 ° C)
• (including 20 min to climb to 60 ° C)

Rinse in warm water between each wash.

A succession of 10 washes is thus carried out at 60 ° C. and 90 ° C., then the degree of polymerization of the cellulose (DP) is measured.

The results are obtained from the following table in which, on the one hand, the residual DP after 10 washes at 60 ° C. is indicated and, on the other hand, the residual DP after 10 washes at 90 ° C.

The initial PD for the fabric designated commercially under the reference EMPA 301 (S27) is 2000.

It is noted that the chloroformamidine sulfate (SCF) used at the dose where it has a good activating efficiency, only causes a slight reduction in the degree of polymerization of the cellulose; at the same dose, the sodium and calcium salts of cyanamide cause much higher degradation.

EXAMPLE 7 Effect on the dyes

This particular test was carried out with the aim of reproducing the action that a deposit of detergent could have in a fold of fabric when a washing by soaking is carried out.

The detergent mixtures, which differ only in the nature and the quantity of activator, are placed inside small bags of identical dimensions made with each of the dyed fabrics to be tested. These bags are placed in a beaker containing two liters of water at 50 ° C, and kept in immersion for two hours; after this time, the temperature of the bath is approximately 40 ° C .; then the small bags are unstitched and the fabrics rinsed and dried; the degradation of the dyes is then evaluated qualitatively relative to the control treated in the same way but with a detergent mixture without activator.

• - turquoise réactif: tissu coton teint avec le colorant commercialisé sous la marque bleu réaction FGL
• - bleu phtalogène: maille coton teint avec le colorant commercialisé sous la marque bleu phtalogène IF3 GK
• - brun réactif: tissus de coton teint avec le colorant commercialisé sous la marque trichromie en Rémazol.

The dyed fabric samples used are:

• - reactive turquoise: cotton fabric dyed with the dye sold under the blue reaction FGL brand
• - phthalogen blue: cotton mesh dyed with the dye marketed under the phthalogen blue brand IF3 GK
• - reactive brown: cotton fabrics dyed with the dye sold under the three-color brand in Rémazol.

• lessive 6 g
• perborate 1 g
• activeur 0,4 g dans le cas de SCF et TAED
• 0,2 g dans le cas des cyanamides calcique ou mo- nosodique.

The quantities used in each test are:

• detergent 6 g
• perborate 1 g
• activator 0.4 g in the case of SCF and TAED
• 0.2 g in the case of calcium or monosodium cyanamides.

It is found that none of the compositions used has caused degradation of the phthalogenic blue.

The fabric dyed with reactive Turquoise and having contained the mixture activated by CaCN _z has some small white dots after tests.

The reactive brown is more sensitive than the two preceding ones but the color of the fabric which contained the mixture of detergent and perborate without activator is not modified; chloroformamidine sulfate only caused a weakening of the color which remained uniform and without a halo; monosodium cyanamide leads to a more marked weakening of the color and the formation of rather diffuse and not very visible halos and spots; the fabric of the bag having contained CaCN ₂ is marked with a multitude of small yellow spots; It is the TAED which degrades this dye the most strongly: the tissues which contained this activator have taken on non-uniform light brown colorations tending to yellow.

Claims (8)

1. Stable bleaching composition consisting of a bleaching agent able to release oxygen and an activator introduced in a sufficient amount to activate the said bleaching agent, characterized in that the said activator is an amidine of the formula

wherein:

B is hydrogen, a halogen, an alkyl, aryl, alkylaryl, cycloalkyl, thioalkyl, oxyalkyl, acyl, mineral acid, such as S0₃H, or organomineral radical;

R_1' R₂ and R₃ are hydrogen, an alkyl, aryl, alkylaryl, cycloalkyl or acyl radical; and HA symbolizes a mineral or organic monoacid or the equivalent part of a polyacid.

2. Stable bleaching composition according to claim 1, characterized in that the amidine is selected from the class of haloformamidines having the formula X - C (= NH) - NH₂, HA, wherein X is a halogen.

3. Stable bleaching composition according to claim 2, characterized in that the amidine selected from the group of the haloformamidines consists of chloroformamidine in the form of the chloride, nitrate, sulfate or phosphate solely or in admixture.

4. Stable bleaching composition according to claim 2, characterized in that the amidine introduced in an amount sufficient to activate the bleaching agent consists of chloroformamidine sulfate

5. Solid stable bleaching composition consisting of the combination of a solid pulverulent and watersoluble derivatives releasing hydrogenperoxide in an aqueous alkaline solution and of an amidine according to one of the claims 1 to 4 in an amount sufficient to activate the release of hydrogenperoxide at normal or moderate temperature.

6. Solid stable bleaching composition according to claim 5, characterized in that the bleaching agent is sodium perborate.

7. Liquid stable bleaching composition consisting of hydrogen peroxide and an amidine according to one of the claims 1 to 4.

8. Solid stable bleaching composition according to one of the claims 5 or 6, characterized in that it contains additionally detergents.