DE3818657A1 - Stable aqueous suspension of silicates which are insoluble in water and capable of binding calcium ions, and the use thereof for producing detergents and cleaners - Google Patents

Abstract

Stable, pumpable aqueous suspension of a silicate which is insoluble in water and is capable of binding calcium ions and which contains, based on the total weight of the aqueous suspension, a) as silicate capable of binding calcium, 0.5 to 80 per cent by weight of a finely divided, synthetic compound which contains bound water, is insoluble in water and has the general formula (Cat2/nO)x.Me2O3.(SiO2)y in which Cat is a cation which has n charges and can exchange with calcium, x is a number from 0.7 to 1.5, Me is boron or aluminium and y is a number from 0.8 to 6, and b) as dispersant component 0.5 to 6 per cent by weight of a mixture of at least two oxo alcohol ethoxylates of the formula II R-(OCH2CH2)n-OH, where R = C10-C15-alkyl with a maximum degree of branching of 25%, i.e. a maximum of 25% of the fatty alcohol ethoxylate has a single methyl branch, n = 3-5.5 mol of EO for component 1, n = 5.75-7 mol of EO for component 2. The suspension can be used to produce detergent and cleaning powders.

Description

Processes for washing and cleaning of solid materials, especially textiles, and for the implementation of the procedures appropriate washing and Detergents suggested in which the role of Calcium complex binding phosphates in whole or in part capable of binding calcium, finely divided, in containing general bound water, water-insoluble aluminum silicates is taken over (cf. DE-OS 24 12 837).

These are compounds of the general Formula I.

(Kat _{2 / n} O) _x · Me₂O₃ · (SiO₂) _y (I),

in the cat a calcium-exchangeable cation of valence n , x is a number from 0.7 to 1.5 Me aluminum and y is a number from 0.8 to 6, preferably ovn 1.3 to 4.

Sodium is preferred as the cation, but it can also replaced by lithium, potassium, ammonium or magnesium be.  

Those defined above that are capable of binding calcium Connections are as follows for the sake of simplicity referred to as "aluminum silicates". This is especially true also for the preferred ones Sodium aluminum silicates; all for their invention Information used and all information about their manufacture and properties apply accordingly to the entirety of all the connections defined above.

For use in detergents and cleaning agents particularly suitable aluminum silicates have Calcium binding capacity of preferably 50 to 200 mg CaP / g of anhydrous aluminum silicate. If below anhydrous aluminum silicate is referred to is this means the state of the aluminum silicates, which is after drying for one hour at 80 ° C is achieved. At this The adhering and the bound water become drying practically completely removed.

In the manufacture of detergents or cleaning agents, in which in addition to the usual components of such agents Aluminum silicates defined above are present advantageous to start from aluminum silicates that are moist are, for example, still from their manufacture. Man mixes the wet compounds at least a part of the remaining components of the By means of and transfers the mixture by known measures, such as spray drying in the finished washing or Detergent as the end product, for example in one pourable product.

As part of the manufacturing process outlined above for detergents or cleaning agents Aluminum silicates, for example as an aqueous suspension  delivered or used. There would be certain Improvements in suspension properties - e.g. B. Suspension stability and pumpability - the in aqueous phase still dispersed aluminum silicates he wishes.

It is known for the formation of aluminum silicate suspensions To use alkylphenol ethylene adducts. For example Adducts with 6 to mol of ethylene oxide used (DE-OS 26 15 698).

Because of the increasing ecological awareness increasing attention to biodegradability placed. In addition to the primary degradation, the loss of surface-active properties, more and more is also available secondary mining, mineralization, in the foreground.

Both the primary and the secondary in particular Degradation are from the linearity of the carbon chain dependent, that is, the dismantling usually so much is worse, the more branched the carbon chain is.

The nonylphenol ethoxylates used in DE-OS 32 09 631 apply due to their benzene ring and their branched Nonyl residues as poorly degradable, in particular the There is a risk that toxic nonylphenyl as metastable breakdown product is created. On the use of For this reason, nonylphenol ethoxylates were used by the German detergent industry waived. In Switzerland the use should be prohibited.

When used in DE-OS 34 44 311 Iso-tridecyl alcohol ethoxylates are like that Name already suggests using branched-chain oxo alcohols  a degree of branching of at least 50%. Acting it is unmanageable mixtures of isomers, often with all possible branches such as methyl, ethyl, propyl, isopropyl u. a.

There was therefore the prejudice that preferred only such branched surfactants for zeolite A slurry stabilization own.

It has now been found that certain mixtures of largely linear oxo alcohol ethoxylates throughout particularly have the ability to suspend the the above calcium-binding aluminum silicates stabilize that even with high solids content stable for a long time and still after long standing are perfectly pumpable. Surprisingly, has demonstrated that these particular blends are able even damp aluminum silicates that have a water content of 70% and less, without for a long time Stir to keep sedimentation stable.

The invention relates to an aqueous, pumpable, stable suspension of a water-insoluble, for binding Calcium ions enabled silicate, which thereby is characterized that it is based on the total weight the aqueous suspension

• a) as capable of binding calcium silicate 0.5 to 80 percent by weight of a finely divided, bound water-containing, synthetically produced, water-insoluble compound of the general formula (Kat _{2 / n} O) _x · Me₂O₃ · (SiO₂) _y (I), in the cat is a calcium-exchangeable cation of the valence n , x is a number from 0.7 to 1.5 Me boron or aluminum and y is a number from 0.8 to 6, and
• b) as a dispersing component 0.5 to 6% by weight, preferably 1 to 2% by weight, in particular 1.4 to 1.6% by weight, a mixture of at least two oxo alcohol ethoxylates of the formula II R- (OCH₂CH₂) _n - OH, where R = C₁₀-C₁₅ alkyl with a degree of branching of at most 25%, ie that at most 25% of the fatty alcohol ethoxylate have a simple methyl branch. n = 3-3.5 mol EO for component 1
  n = 5.75-7 moles of EO for component 2.

For component 1, n = 3 to 5.0 moles of EO.

For component 2, n = 5.5 to 7.0 moles of EO.

In the suspension according to the invention, component A be crystalline.

In formula I of component A, y can be a number from 1.3 to 4.

The crystalline component A can in a preferred Type A zeolite.

The above compounds are the essential ones Components of the suspension according to the invention. It can   however, other ingredients may also be included, e.g. B. foam-suppressing additives or solubilizers, d. that is, compounds that increase the solubility of the added Improve dispersant in the aqueous phase. As Foam dampers can be the usual foam suppressants Substances, for example foam-suppressing soap, Silicone defoamers, foam-reducing triazine derivatives that are all known and familiar to the specialist will. Such an addition is generally not required; with foaming dispersants it can however - especially when higher amounts of alkylbenzenesulfonic acid are used - be desired.

An addition of solubilizing substances is also in the not generally required, but may be indicated if the suspension according to the invention as a stabilizing Medium a hydrophilic but not very soluble in water Contains colloid such as polyvinyl alcohol. Z is advantageous. B. a solubilizer - very suitable are sodium toluenesulfonate or polyglycol ether - used.

The proportion of the solubilizer in the total suspension can for example be of the same order of magnitude as the Proportion of the stabilizing agent. More than Suitable mediators are connections to the professional world well known; hydrotrophic agents such as Benzenesulfonic acid, xylenesulfonic acid or their Water-soluble salts or octyl sulfate are suitable.

With all information on the "concentration of Aluminum silicates "to the" solids content "or to the content of "Active substance" (= AS) is based on the state of the Aluminum silicates referenced after one hour Drying at 800 ° C is achieved. During this drying  the adhering and the bound water practically completely away.

In the case of the aluminum silicates of component A to be used can be amorphous or crystalline products act, of course also mixtures of amorphous and crystalline products and also semi-crystalline Products can be used. The aluminum silicates can naturally occurring or synthetically produced Be products, the synthetically produced Products are preferred. The production can e.g. B. by Reaction of water-soluble silicates with water-soluble ones Aluminates take place in the presence of water. To this Purpose can be aqueous solutions of the starting materials mixed together or one in solid state present component with the other as aqueous Solution present component are implemented. Also through Mix the two, present in solid state Component is obtained in the presence of water desired aluminum silicates. Also from Al (OH) ₂, Al₂O₃ or SiO₂ can be reacted with alkali silicate or aluminate solutions Manufacture aluminum silicates. The Production can also by other known methods respectively. In particular, the invention relates to Aluminum silicate, which is a three-dimensional Show space lattice structure.

The preferred, approximately in the range of 100 to 200 mg CaO / g AS usually around 100 to 180 mg CaO / g AS Calcium binding capacity is found primarily in compounds the composition:

0.7-1.1 Na₂O · Al₂O₃ · 1.3-3.3 SiO₂

This empirical formula comprises two types of different ones Crystal structures (or their non-crystalline structures Intermediate products), which are also characterized by their empirical formulas differentiate. They are:

• a) 0.7-1.1 Na₂O · Al₂O₃ · 1.3-2.4 SiO₂
• b) 0.7-1.1 Na₂O · Al₂O₃ · 2.4-3.3 SiO₂

The different crystal structures are shown in the X-ray diffraction pattern.

The amorphous or in aqueous suspension crystalline aluminum silicate can be filtered separate from the remaining aqueous solution and at Temperatures of e.g. B. dry 50 to 400 ° C. Depending on the The product contains more or less drying conditions bound water.

Such high drying temperatures are generally not recommendable; expediently one does not go over 200 ° C beyond when the aluminum silicate for use is provided in detergents and cleaning agents. The However, aluminum silicates need to be manufactured for the preparation of a suspension according to the invention at all not to be dried; rather, it can - and it is particularly advantageous - one from the manufacture still damp aluminum silicate can be used. Leave it however, even at medium temperatures, for example at 80 to 200 ° C until the adhesive is removed aluminum silicates dried in liquid water Use preparation of suspensions according to the invention.  

The particle size of the individual aluminum silicate particles can be different and z. B. in the range between 0.1 µ and 0.1 mm. It is used with particular advantage Aluminum silicates made up of at least 80% by weight of particles a size of 10 to 0.01 µ, in particular from 8 to 0.1 µ consist.

These aluminum silicates preferably do not contain any Primary or secondary particles more with diameters above 45 µ. Secondary particles are particles that by aggregating the primary particles into larger ones Formations have arisen, referred to.

With regard to the agglomeration of the primary particles too Larger entities have used their Production of still moist aluminum silicates for production the suspensions according to the invention have been particularly successful since it has been found that when using this still moist products practically form agglomerates is completely prevented.

In a particularly preferred embodiment of the Invention is used as component A powdered zeolite Type A with a particularly defined particle spectrum used.

Such zeolite powder can according to DE-AS 24 47 021, DE-AS 25 17 218, DE-OS 26 52 419, DE-OS 26 51 420, DE-OS 26 51 436, DE-OS 26 51 437, DE-OS 26 51 445, DE-OS 26 51 485 can be produced. You can point that out there specified particle distribution curves.

In a particularly preferred embodiment, a Type A powdered zeolite can be used which that described in DE-OS 26 51 485 Has particle size distribution.  

The concentration of component A can preferably be 44 to 55% by weight, in particular 46 to 52 percent by weight and more be.

Component B can preferably be a mixture of two oxo alcohol ethoxylates, one of which Component an oxo alcohol ethoxylate with 3 to 5.5 mol Ethylene oxide and the cloud point 56-71 ° C preferably with 4-5 mol EO and the cloud point 62-67 ° C, the Carbon chain R 10-15 preferably 12-13 carbon atoms and the second component (B) Oxo alcohol ethoxylate with 5.75 to 7 moles of ethylene oxide and the cloud point 72 to 80 ° C, preferably with 5.5-6.5 mol EO and the cloud point 72-77 ° C, the Carbon chain R 10-15, preferably 12-15 carbon atoms having.

Component B can preferably be a mixture of two oxo alcohol ethoxylates, one of which Component an oxo alcohol ethoxylate with 3 to 5.0 mol Ethylene oxide and the cloud point 56-69 ° C preferably with 4-5 mol EO and the cloud point 62-67 ° C, the Carbon chain R 10-15 preferably 12-13 carbon atoms and the second component (B) Oxo alcohol ethoxylate with 5.75 to 7 moles of ethylene oxide and the cloud point 70 to 80 ° C, preferably with 5.5-6.5 mol EO and the cloud point 72-79 ° C, the Carbon chain R 10-15, preferably 12-15 carbon atoms having.

The oxo alcohol ethoxylates can be used in a ratio of 9: 1 to 1: 9, preferably 2: 3 to 3: 2, in particular 0.9: 1.1 to 1.1: 0.9 mixed together.

The concentration of this mixture in the aqueous Suspension can preferably be from 1 to 2% by weight, in particular from 1.4 to 1.6% by weight. These Concentration is sufficient, a suspension with one Stabilize solids content of 50 wt .-% and more.

The suspension according to the invention has the advantage that them in the temperature range of 10 to 50 ° C is stable to sedimentation and has a pumpable consistency having.

Another advantage is that the oxo alcohol ethoxylate Room temperature is liquid and therefore not heated are needed.  

It is of particular advantage that in the Suspension significantly higher solids content of 50% by weight and more can be achieved.

The known suspension according to DE-OS 26 15 698 has one lower sedimentation stability and is the same Type of incorporation at room temperature not homogeneous and therefore more difficult to process.

Basically, the aqueous suspensions other than the constituents A and B and except where appropriate of starting materials for the production of these Contain components in comparatively small amounts. Is a further processing of the suspension into washing and Detergent provided, so it is additional substances present are of course expedient to substances that are part of washing and Detergents are suitable.

It gives an indication of the stability of the suspension a simple test in which one Aluminum silicate suspension of the desired concentration - e.g. B. 31% - is produced, which is an inventive Dispersing agents and optionally other substances, for example detergent ingredients such as Contains pentasodium triphosphate in various amounts. The influence of the added substance can then Sedimentation behavior of the suspension can be observed visually. After standing for 72 hours, a preferred suspension in the generally be so far removed that the protruding clear solution or free of silicate particles not more than 20%, preferably not more than 10%, in particular not more than 6% of the total amount.  

In general, the amount of additives should be kept so be that the suspension after 24 hours, preferably after 48 hours and especially after 72 hours Stand in storage containers and pipe or hose lines can still be pumped perfectly again. The Settling behavior of the possibly further Components containing suspension is at Room temperature checked. They are also after 4 or 8 days perfectly pumpable. This information about the Suspension stability only gives clues; it depends on each individual case, what suspension stability is to be set. When using the invention Suspension as stock suspension for longer storage in a reservoir from which they can be pumped as needed can be deducted, it may be appropriate to share other ingredients such as washing and Keep cleaning products low or approach them entirely dispense.

The suspensions can be made by simply mixing their Components are made, the Aluminum silicates e.g. B. as such or - if necessary from the production - already wet or in water Suspension can be used. Especially It is advantageous to use component B in its Manufacture still moist aluminum silicates z. B. as Stir in the filter cake.

Of course, it is also possible to d. H. freed of adhering water, if necessary still aluminum silicates containing bound water will.  

The suspensions according to the invention are notable for high Stability and other advantages. Your stabilizing effect is particularly at Aluminum silicates with particle sizes from 5 to 30 µ particularly valuable. They are pumpable, so they are one enable easy handling of moist aluminum silicates. Even after long interruptions in the pumping process the suspensions can be pumped around perfectly. Because of your The suspensions are also very stable in the usual way Tank and tank wagons can be transported without one Formation of unusable or disruptive residues fear. The suspensions are excellent as a form of delivery of aluminum silicates for the Suitable for delivery to detergent manufacturers, for example.

The suspensions can be at room temperature or else keep at higher temperatures, by piping pump or otherwise transport. Mostly done the handling of the suspensions at temperatures between Room temperature - usually preferred - and about 50 ° C.

The suspensions according to the invention are particularly suitable appearing to be dry for further processing, pourable or free-flowing products, for example for the production of powdered aluminum silicates. It there are no annoying residues when feeding the aqueous suspensions for drying apparatus. Further has been shown that the suspensions of the invention a Processing to extremely dust-free products enable.

Because of their particular stability, the Suspensions according to the invention already as such, d. H.  without further processing with or without further washing, bleaching and / or cleaning additives, for example as a water softener, washing or Detergent and especially as a mild liquid Abrasives with increased suspension stability can be used.

A particularly important use of the suspension is Further processing to appear dry, bulk or free-flowing detergents and cleaning agents, in addition to the Suspension components contain other compounds.

The suspensions according to the invention are in particular for Manufacture of powder detergents suitable.

An aqueous, flowable premix of the individual components of the Funds and introduces them in the usual way pourable product over. Doing the above defined aluminum silicates in the form of the invention Suspension initiated. The suspensions according to the invention can be made into solid, pourable detergents and cleaning agents will.

In particular, one goes in the production of powdery, free-flowing detergents and cleaning agents so that a suspension according to the invention - for example from a storage container - with at least a washing, bleaching or cleaning effect Part of the agent to be mixed and that Mix into the mixture by any method powdered product transferred. One will be advantageous  Complexing agent added, d. H. a connection that the alkaline earth metal ions responsible for the water hardness, especially complex to bind magnesium and calcium ions can

In general, in the manufacture of washing and Detergents the suspension according to the invention preferably with at least one not possible Components of component B belonging to water-soluble Surfactant combined.

In the manufacture of detergents and cleaning agents there are different variants.

For example, the suspensions according to the invention with substances capable of binding crystal water be combined, conveniently by spraying the Suspension to that in a mixer, for Binding of water of crystallization, so that with constant mixing, finally a solid, dry appearing product is obtained. Preferably be the suspensions according to the invention, however, as a "slurry" mixed, washing with at least one other, bleaching or cleaning compound of the Subjected to spray drying. Here show up further surprising advantages of the claimed Aluminum silicate suspension. It has been shown that when using suspensions according to the invention in the Spray drying to obtain very low-dust products can be. Those obtained by spray drying Products have a high calcium binding capacity and are well wettable.  

Detergents using the ones described above Suspension can be made on be composed in different ways. In general they contain at least one not according to the invention dispersants used in the claimed Aluminum silicate suspensions are available water soluble surfactant. Generally they contain next to at least one other compound that washes, has a bleaching or cleaning effect and is inorganic or is organic as a calcium binding compound like Aluminum silicate defined above. In addition, in such means other usual, mostly in small Amounts of auxiliary substances and additives present.

Examples

It becomes a zeolite filter cake and stabilizer stirred, if necessary with the addition of water.

As a stabilizer compounds according to the Formula II used. The degree of ethoxylation is given EO. The zeolite A filter cake used is according to DE-OS 26 51 485 produced and has the specified there Particle spectrum.

For the implementation of the examples, 50 kg unstabilized zeolite suspension with an Ekato standard mix stirrer, equipped with a wing disc, one hour at 500 rpm, optionally with the addition of Water, stirred up.

After adding 1.5% by weight of stabilizer mixture, 10 Minutes continued at the same speed.  The evaluation is carried out as Table I illustrates after 3 days.

The cloud points of the stabilizers used are in described in Table I.

Table I

Cloud points according to DIN 53 917 of the fatty alcohol ethoxylates used

(5 g surfactant in 25 g, 25% butyl diglycol solution)

In Tables II to VIII below, the Oxo alcohols with the carbon chains C₁₂ / C₁₃ as Denoted oxo alcohols 23.

Correspondingly, an oxo alcohol with C₁₄ / C₁₅ is an oxo alcohol 45 or an oxo alcohol with C₁₂ / ₁₅ an oxo alcohol 25.

Oxo alcohol 23-4.5 / 5.5 denotes a 1: 1 mixture of Oxo alcohol C₁₂ / C₁₃ with 4.5 mol EO with an oxo alcohol C₁₂ / C₁₃ with 5.5 mol EO.

The zeolite A concentration is in all examples 50%.  

Table II

Stabilization of Wessalith S with oxo alcohol ethoxylates with R = alkyl with C₁₂-C₁₅ chain length

Table III

Stabilization of Wessalith S with oxo alcohol ethoxylates with R = alkyl with C₁₂-C₁₅ chain length

Table IV

Stabilization of Wessalith S with oxo alcohol ethoxylates with R = alkyl with C₁₂-C₁₅ chain length

Table V

Stabilization of Wessalith S with oxo alcohol ethoxylates with R = alkyl with C₁₂-C₁₅ chain length

Table VI

Stabilization of Wessalith S with oxo alcohol ethoxylates with R = alkyl with C₁₂-C₁₅ chain length

Table VII

Stabilization of Wessalith S with oxo alcohol ethoxylates with R = alkyl with C₁₂-C₁₅ chain length

Table VIII

Stabilization of Wessalith S with oxo alcohol ethoxylates with R = alkyl with C₁₂-C₁₅ chain length

Little branched tridecyl alcohol ethoxylates, which in Degree of branching that used according to the invention Oxo alcohol ethoxylates are not suitable Suitable for slurry stabilization, such as Examples 9-33 occupy.

Because of this, it was surprising that a combination from these little branched products like that a zeolite A slurry used according to the invention can stabilize excellently.

The oxo alcohol ethoxylates used according to the invention are 80% linear and only one in the remaining 20% Methyl branch on. For this reason, you have one very good biodegradability.

Claims (9)

1. Aqueous pumpable, stable suspension of a water-insoluble silicate capable of binding calcium ions, characterized in that it is based on the total weight of the aqueous suspension

• A) as a silicate capable of binding calcium 0.5 to 80 percent by weight of a finely divided, bound water-containing, synthetically produced, water-insoluble compound of the general formula (Kat _{2 / n} O) _x · Me₂O₃ · (SiO₂) _y (I), in the cat is a cation exchangeable with calcium of the valence n , x is a number from 0.7 to 1.5 Me boron or aluminum and y is a number from 0.8 to 6 and
• B) as a dispersing component 0.5 to 6 percent by weight of a mixture of at least two oxo alcohol ethoxylates of the formula II R- (OCH₂CH₂) _n -OH, where R = C₁₀-C₁₅ alkyl with a degree of branching of at most 25%, ie that at most 25 % of the fatty alcohol ethoxylate have a simple methyl branch n = 3-5.5 mol EO in component 1
  n = 5.75-7 moles of EO for component 2.

2. Suspension according to claim 1, characterized in that component A is crystalline. 3. Suspension according to claims 1 or 2, characterized in that in formula I of component A y is a number from 1.3 to 4. 4. Suspension according to claims 1 to 3, characterized characterized in that component A is a zeolite A. 5. Suspension according to claims 1 to 4, characterized characterized in that component B from a mixture of two oxo alcohol ethoxylates, one of which Component an oxo alcohol ethoxylate with 3 to 5.5 mol Ethylene oxide and the cloud point 56-71 ° C preferred with 4-5 mol EO and the cloud point 62-67 ° C, the carbon chain R 10-15 preferably 10-12 Has C atoms and the second component (B) Oxo alcohol ethoxylate with 5.75 to 7 moles of ethylene oxide and the cloud point 72 to 80 ° C, preferably with 5.5-6.5 mol EO and the cloud point 72-77 ° C, the Carbon chain R 10-15, preferably 12-15 C atoms, having.   6. Suspension according to claim 5, characterized in that the mixing ratio of the two C₁₂-C₁₅ oxo alcohol ethoxylates 9 to 1 to 1 to 9. 7. Use of the aqueous suspension according to the claims 1-6 for the production of powdered washing and Cleaning supplies.   8. Aqueous pumpable, stable suspension of a water-insoluble silicate capable of binding calcium ions, characterized in that it is based on the total weight of the aqueous suspension

• A) as capable of binding calcium silicate 0.5 to 80 percent by weight of a finely divided, bound water-containing, synthetically produced, water-insoluble compound of the general formula (Kat _{2 / n} O) _x · Me₂O₃ · (SiO₂) _y (I), in the cat is a cation exchangeable with calcium of the valence n , x is a number from 0.7 to 1.5 Me boron or aluminum and y is a number from 0.8 to 6 and
• B) as a dispersing component 0.5 to 6 percent by weight of a mixture of at least two oxo alcohol ethoxylates of the formula II R- (OCH₂CH₂) _n -OH, where R = C₁₀-C₁₅ alkyl with a degree of branching of at most 25%, ie that at most 25 % of the fatty alcohol ethoxylate have a simple methyl branch n = 3-5.0 mol EO in component 1
  n = 5.5-7 moles of EO for component 2.

9. Suspension according to claims 1 to 4, characterized characterized in that component B from a mixture of two oxo alcohol ethoxylates, one of which Component an oxo alcohol ethoxylate with 3 to 5.0 mol Ethylene oxide and the cloud point 56-69 ° C preferred with 4-5 mol EO and the cloud point 62-67 ° C, the carbon chain R 10-15 preferably 12-13 Has C atoms and the second component (B) Oxo alcohol ethoxylate with 5.5 to 7 moles of ethylene oxide and the cloud point 70 to 80 ° C, preferably with 5.5-6.5 mol EO and the cloud point 71-79 ° C, the Carbon chain R 10-15, preferably 12-15 carbon atoms having.