FR2816954A1 - Aqueous borated solution obtained from a mixture of boric acid and sodium carbonate, useful in water treatment and substituent for starch glues - Google Patents

Abstract

An aqueous concentrated borate solution comprises a quantity of boric trioxide, a borate, an aminoborate, an antifermenting agent and optionally a sequestrant or complexant additive. A highly concentrated borate solution comprises a quantity of borate, as 5-40 % of B2O3, a borate formed from a carbonate from sodium carbonate or bicarbonate, potassium carbonate or mixtures, an aminoborate formed from a borate compound an alkanolamine from ethanolamine, diethanolamine or mixtures, an anti-fermenting agent from a quaternary ammonium, isothiazolinone (optionally chlorinated) or a mixture, and optionally an additive with sequestrant or complexant properties for heavy metals or alkaline earth metals chosen from a polycarboxylic acid and/or ethylenediamine tetraacetic acid sodium salt or mixtures. An Independent claim is also included for the preparation of the borate solutions.

Description

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 The present invention relates to an aqueous boron solution, its method of preparation and its use as a substitute for borates in powder form, especially in processes for the preparation of corrosion inhibitor or for the preparation of starch adhesive, among others.

 Most materials for industrial use are made of different metals such as copper and its alloys, galvanized steel, aluminum or iron and its alloys. In contact with air and / or water, its materials undergo disturbing transformations, called corrosion phenomena.

 The preparation of starch-based glue in the corrugated board industry is basically ensured by the dispersion of starch from wheat or corn or potato starch into the water and added with sodium hydroxide (NaOH, soda).

 Sodium hydroxide promotes the oxidation of ferrous metals and causes the formation of rust.

 The removal of glue is provided mainly by a cylinder glue.

 The surface of the cylinder is designed by micro cells to deposit a string of glue on the crest of the corrugated paper groove.

 Too high a oxidation deforms these cells and causes an irregularity of the formation of the glue film on the cylinder to glue. As a result, the amount of glue will be imperfectly deposited on the corrugated paper.

 Therefore, the present invention aims to achieve a borated liquid additive capable, in particular to reduce the corrosion of metals.

 It is known from the prior art that the most widely used organic substances for the preparation of corrosion inhibitor are aliphatic amines having a molecular weight of less than 300. Such as alkanolamines and their water-soluble salts obtained by neutralization stoichiometric using boric acid in a molar ratio of 1: 1 to 1: 4, described in DE 2 908 301, free from exploitation.

 Force to note that the prior art is imperfect to the possible use of the invention for the preparation of starch adhesive.

 According to another object of the invention is its use for substituting pulverulent polyborates used in the corrugated board industry, among others.

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 In the case of starch glues, it should be known that the viscosity is ensured basically by the gelling of the starch using sodium hydroxide (sodium hydroxide).

 Indeed, if soda is added slowly in starch paste at room temperature, it is cooked. The starch thus cooked will be much more tacky and less pasty than a starch cooked only by heating.

1 isser cette te grâce à la soude, il est possible d'abaisser cette température. Si la température de gélification est trop basse (inférieur à 54Oc) il y a risque de gélification intempestive dans les tuyauteries ou les bacs à colle d'ou des variations de viscosité et de collage et des déposes trop importantes. The controlled addition of sodium hydroxide thus makes it possible to reduce the amount of heat to be added to the glue to gel it. Starch can cook around 74c and

To emit this te thanks to the soda, it is possible to lower this temperature. If the gelling temperature is too low (less than 54Oc) there is a risk of inadvertent gelation in the pipes or glue tanks or viscosity variations and gluing and excessive deposits.

 Therefore, a large excess of sodium hydroxide considerably reduces the gelation temperature.

 In known manner, the use of the borax compound (B4O7Na2) makes it possible to inhibit this phenomenon. Borax is a natural product extracted in mines. Borax reacts exclusively with the fired portion of the glue and modifies the rheological properties of the glue.

 Borax thus makes it possible to improve the quality of the glue by providing it with properties with regard to the functions of adhesion promoter, plasticizer, a shooting texture, and freezing the glue on paper, among others.

 Borax is a poorly soluble compound, about 5% in water.

 US Pat. No. 3,228,781, which is free of exploitation, discloses a process for producing starch-based glue in which it is specified that a storage tank contains "liquid borax". Furthermore, the patent states that the "liquid borax" is conveyed by the same supply line of liquid sodium hydroxide without particular precautions.

Under these conditions, it may be thought that a mixture or a reaction is carried out between the "liquid borax" and the sodium hydroxide by means of the alternative path of the two products,
Force to notice that the prior art is imperfect by its lack of explanation on the exact composition of the "liquid borax".

 It is known from the patent BE 842 649, free operating, which describes highly concentrated solutions of polyborates resistant to extreme cold.

These solutions are used as a son impregnating adjuvant,

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Forcer de constater que l'art antérieur démontre qu'il suffit de mélanger de l'acide borique et une alcanolamine, notamment la monoéthanolamine, dans un rapport molaire de la base à l'acide borique compris entre 1 et plus de 2, pour atteindre une concentration en acide borique supérieur à 30g dans une solution portée à 100ml par de l'eau sous agitation pour obtenir un mélange homogène.

Force to note that the prior art demonstrates that it is sufficient to mix boric acid and an alkanolamine, especially monoethanolamine, in a molar ratio of base to boric acid of between 1 and more than 2, to reach a concentration of boric acid greater than 30 g in a solution heated to 100 ml with water to obtain a homogeneous mixture.

 In order to obtain a borate additive in stable liquid form capable of substituting borax, having a high effectiveness of viscosity enhancer of the starch adhesive.

 A process for the preparation of a borated solution has been described in patent FR 98. 13390, in that it is obtained from a highly concentrated borated solute formed by a mixture of boric acid and a compound alkanolamine in water without formation of sodium borate and that it contains, especially a soap and possibly antiferment.

Previously to this French patent, it has been described in the patent
EP 0 326 247 (Cerestar holding) a borated solution characterized in that it is formed based on boric acid and monoethanolamine, only and without possible initialization of sodium borate.

 In fact, in order to solve the same problem as the two previous patents for a particular use in the preparation of starch glue, it has been advantageously found a new, more economical method for the preparation of borated solution.

 It has been found that it is possible to neutralize a quantity of boric acid with sodium carbonate, in order to reduce the amount of monoethanolamine.

 By this new process the weight ratio between boric acid and ethanolamine can be reduced to a ratio of 4 instead of 3 previously.

 It is customary in industrial trade that sodium carbonate is approximately 4 times as expensive as ethanolamine.

 Therefore, an essential objective of the invention is to produce a borated solution comprising as little as possible of monoethanolamine.

 Patent FR 95 02391 describes a borated aqueous solution comprising: a theoretical amount of B203 of between 25 and 55% by weight.

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 at least one complex solubilized between a borated product and an organic amine and / or polyhydroxyl compound.

 and optionally at least one biocide and / or antifoam and / or anionic or nonionic surfactant. and obtained from at least one borated solute initially formed by a mixture of: at least one borate boric acid and / or B2B3 and optionally at least one strong base and in that its pH is between 6 and 9.

The patent specifies in claim 5 that the use of the invention is characterized in that the solution comprises at least initially a strong mineral and / or organic base, preferably hydroxylic, and more preferably still selected from the following products: NaOH . KOH,
LiOH and mixtures thereof.

It is specified in claim 9 that the preparation process of the invention is characterized in that solubilization is carried out in solutes at a temperature of between 20 c and 55 c.
Under these conditions, it is apparent from the prior art that the formation of a borate can be achieved with a strong base.

 Force to note that the process of the prior art is imperfect or even failing with respect to the borate solution borate solution process.

 Sodium hydroxide is a very caustic component. Sodium hydroxide solutions are concentrated aqueous solutions of sodium hydroxide. Because of their very destructive effect on tissues and mucous membranes, sodium hydroxide and / or sodium hydroxide solution must be handled according to very strict safety instructions.

 The pH of a concentrated sodium hydroxide solution is 14.

Répertoire des produits chimiques dangereux. tD
Tandis que le carbonate de sodium est un produit peu dangereux, classé dans la catégorie de substance irritante. Sodium hydroxide is listed in Table C, a corrosive substance,

Directory of hazardous chemicals. tD
While sodium carbonate is a low-hazard product, it is classified as an irritant.

 The pH of a concentrated sodium carbonate solution is 11.

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 Therefore, another essential objective of the invention is therefore the particular use of sodium carbonate.

 In a simplified way and without wishing to be bound by a complex theory, it is demonstrated that the stability of the new invention of a concentrated borated solution passes, on the one hand, by the production of a borate using carbonated sodium.

 It is known that sodium pentaborate is very similar in water, a saturated solution at 20GC contains 15.2% by weight.

 The pH of a solution at 0. 1mol. (59g / liter) is 7.95 at room temperature.

 By increasing the concentration, the solution becomes slightly acidic.

 The pH range of a solution of sodium pentaborate in water, therefore varies between 6.90 and 7.95 depending on the concentration.

 Hence the importance of pH, it guarantees the presence of sodium pentaborate, excellent miscibility and stability of the various components to constitute the invention.

 It has merit to have highlighted the need to respect the pH zone of the invention, the chemical and economic interest in the particular use of sodium carbonate.

 In this state of affairs, one of the essential objectives of the invention is to provide a concentrated borated solution, in particular, for the preparation of starch-based glue, initially containing a carbonate-type compound of sodium carbonate (Na 2 CO 3) type and / or sodium hydrogen carbonate (NaHCO3), among others, allowing the conversion of boric acid to soluble sodium pentaborate.

We give below the reaction equation between boric acid and sodium carbonate, the skilled person can therefore define the appropriate stoichiometric quantities to obtain a desired amount of sodium pentaborate (maximum amount 15 2%) .

The equation defines a weight ratio: Boric acid 1 sodium carbonate = 5, 8

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IL est connu de l'art antérieur que l'action de la monoéthanolamine sur l'acide borique forme un complexe pleinement soluble dans l'eau. La réaction a été représentée par l'équation

It is known from the prior art that the action of monoethanolamine on boric acid forms a fully soluble complex in water. The reaction was represented by the equation

The equation defined a weight ratio: Boric acid / Monoethanolamine = 3
The action of sodium carbonate makes it possible to consume a quantity of boric acid in a more soluble product.

 Boric acid consumed = 5.8 x Amount of sodium carbonate with a maximum amount of sodium carbonate at 2.7% by weight.

65, 0 % d'acide borique granulé - 16, 3 % monoéthanolamine 2, 7 % carbonate de sodium granulé 16, 0 % eau A-Procédé de préparation de 100g de soluté boré concentré Dans 16g d'eau préchauffé entre 40 C et 50oC, on incorpore sous agitation 2, 7g de carbonate de sodium puis on incorpore sous plus forte agitation la quantité d'acide borique correspondante au rapport pondéral acide borique/carbonate de sodium = 5, 8 soit une quantité d'acide borique égale a 16g sur les 65g initial. On malaxe jusqu'à complète dissolution de l'acide borique. Ensuite on ajoute 163g de monoéthanolamine et on incorpore sous très forte agitation les 49g restant d'acide borique tout en chauffant de manière que la température du mélange soit spérieur à 45 C. We have therefore demonstrated the new possible weight ratio:
Boric acid / Monethanolamine = 4
This gives rise to an example of a new concentrated boron solute formula composed of:

65.0% granular boric acid 16.3% monoethanolamine 2.7% granulated sodium carbonate 16.0% water A-Process for preparing 100 g of concentrated borated solute In 16 g of water preheated between 40 ° C. and 50 ° C. 2.7 g of sodium carbonate are incorporated with stirring and then the amount of boric acid corresponding to the boric acid / sodium carbonate weight ratio = 5.8, ie a quantity of boric acid equal to 16 g, is incorporated under greater agitation. the initial 65g. Knead until complete dissolution of boric acid. Then 163 g of monoethanolamine are added and the remaining 49 g of boric acid is incorporated with very strong agitation while heating so that the temperature of the mixture is greater than 45 ° C.

 After the complete solubilization of the boric acid, the concentrated borated solute must be homogenized for a few minutes at a temperature of between 55 ° C. and 70 ° C., preferably 63 ° C.

 Check the pH of the preparation which should be between 7.00 and 7.80 otherwise adjust the pH with a saturated aqueous solution of sodium carbonate.

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 To this highly concentrated boron preparation is added one or more additives in order to obtain solutions for applications in various fields, particularly in the preparation of starch glues, liquid fertilizers, charcoal, among others.

B-Application for preparation of starch glue
Boron adjuvant composition, expressed in weight ratio
1) Concentrated boron solute --------------------------- 96, 00% 2) anti ferment ---------- The antifreeze is characterized in that it is formed by an isothiazolinonc preparation and / or a preparation of alkyl benzyl dimethyl ammonium chloride, among others.

 The above composition of the invention was used for viscosity measurement tests to determine its performance with respect to borax and a liquid boron solution described in patent FR 98 13390 and the borate solution (test no. 6). ) described in the patent FR 95 02391 on page 12.

1) Conduct of the tests
The various glue preparations were carried out, with a ratio of amount of sodium hydroxide to a quantity of the present invention (and soda / borax) varying.

 The comparisons are made using 112g1m2 corrugated paper based on recycled paper.

- puis ajouter : 2000g d'eau à 20oC 850g amidon de maïs Xg borax ou solution borée General Protocol for the preparation of starch glue
1500g water at 35 C 150g corn starch
15g sodium hydroxide - stirring for 10 minutes at a temperature of 40 ° C

- then add: 2000g of water at 20oC 850g corn starch Xg borax or borated solution

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 stirring for 5 minutes. For ease of measurement, the adhesive is diluted 5 times.

2) Viscosity measurement Brook field Test n 1 soda / borax = soda / borated solution = 1.50

<Tb>
<tb> Type <SEP> Speed (RPM) <SEP> Torque <SEP> (%) <SEP> Viscosity <SEP> (CP)
<tb> borax <SEP> powder <SEP> 100 <SEP> 25 <SEP> 1160
<tb> solution <SEP> en <SEP> 98.133890 <SEP> 100 <SEP> 32 <SEP> 1710
<tb> solution <SEP> borate <SEP> of the <SEP> patent <SEP> en <SEP> 95. <SEP> 02391 <SEP> 100 <SEP> 34 <SEP> 1750
<tb> solution <SEP> borate <SEP> carbonate <SEP> from <SEP> the invention <SEP> 100 <SEP> 33 <SEP> 1930
<Tb>

Essai r 2 soude/borax = soudc/solution borée = 1, 10

Test r 2 sodium hydroxide / borax = weld / borated solution = 1, 10

<Tb>
<tb> Type <SEP> of <SEP> glue <SEP> with <SEP>: <SEP> Speed (RPM) <SEP> Torque <SEP> (%) <SEP> Viscosity <SEP> (CP)
<tb> borax <SEP> 100 <SEP> 38 <SEP> 2310
<tb> solution <SEP> boree <SEP> of the <SEP> patent <SEP> en <SEP> 98. <SEP> 133890 <SEP> 100 <SEP> 60 <SEP> 3400
<tb> solution <SEP> boree <SEP> of the <SEP> patent <SEP> en <SEP> 95. <SEP> 02391 <SEP> 100 <SEP> 65 <SEP> 3380
<tb> solution <SEP> borated <SEP> carbonated <SEP> from <SEP> the invention <SEP> 100 <SEP> 67 <SEP> 3610
<Tb>

3) commentaire des résultats
Le fait de substituer le borax dans les préparations de colles par une solution aqueuse borée se traduit par une nette amélioration de la montée en viscosité. on note également qu'avec une quantité de solution borée égale à une quantité de borax, la viscosité de la colle est nettement supérieure. IL est alors possible de réduire la quantité d'amidon ou la quantité de solution borée pour obtenir une viscosité équivalente avec le borax.

3) comment on the results
The fact of substituting borax in the glue preparations by a borous aqueous solution results in a marked improvement in the rise in viscosity. it is also noted that with a quantity of borate solution equal to a quantity of borax, the viscosity of the glue is significantly higher. It is then possible to reduce the amount of starch or the amount of borated solution to obtain an equivalent viscosity with borax.

 Moreover, the results clearly demonstrate that the borate carbonate solution of the present invention can advantageously substitute a borate solution without borate formation (patent FR 98 13390) and / or a boron solution composed of sodium hydroxide (patent FR 95.02391). ).

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 The invention relates to a highly concentrated borated aqueous solution, characterized in that it comprises: a theoretical expressed quantity of boron trioxide (B 2 O 3) of between 5 and 40%; a borate formed by a carbonate compound chosen from the following products: sodium carbonate, sodium bicarbonate, potassium carbonate and their mixtures; a aminoboron compound formed between a borated product and an alkanolamine compound chosen from the following products: ethanolamine, diethanolamine, and mixtures thereof; antifreeze chosen from the following products: quaternary ammonium, a chlorinated and non-chlorinated isothiazolinone preparation and / or their mixtures; and optionally an additive possessing sequestering or complexing properties with respect to heavy or alkaline earth metal ions chosen from the following products: a polycarboxylic acid or the tetrasodium salt of ethylene diamine tetracetic acid, and mixtures thereof.

* la solution est obtenue à partir d'un soluté boré fortement concentré qui comprend les substances suivantes : - le composé carbonate est le carbonate de sodium - le composé alcanolamine est la monoéthanolamine - le produit boré est l'acide borique. According to other features of the invention,

the solution is obtained from a highly concentrated borated solute which comprises the following substances: the carbonate compound is sodium carbonate; the alkanolamine compound is monoethanolamine; the borated product is boric acid.

- eau-------------1-20% en poids - acide borique---------10-70% en poids - carbonate de sodium poudre---1-3% en poids - monoéthanolamine-------5-24% en poids * le rapport pondéral d'acide borique sur le carbonate de sodium est supérieur à 3, de préférence égal à 5,8 * le rapport pondéral d'acide borique sur la monoéthanolamine est supérieur à 3, de préférence égal à 4 the solution comprises a quaternary ammonium, preferably allcylbenzyl dimethyl ammonium chloride, the concentrated borated solute is formed by a mixture of the following composition:

- water ------------- 1-20% by weight - boric acid --------- 10-70% by weight - sodium carbonate powder --- 1-3 % by weight - monoethanolamine ------- 5-24% by weight * the weight ratio of boric acid to sodium carbonate is greater than 3, preferably equal to 5.8 * the weight ratio of acid boric acid on monoethanolamine is greater than 3, preferably 4

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* la solution a une composition suivante en poids par poids - soluté bore concentré--------20-98% - antiferment-----------1-10% - additif séquestrant ou complexant-----0-20%.

the solution has the following composition by weight by weight - concentrated boron solute ----- 20-98% - antiferrment ------ 1-10% - sequestering or complexing additive ---- 0-20%.

 * the solution is free of antiferment and additive sequestering or complexing.

 The invention also relates to the use of the aqueous boron solution as defined above, in substitution for borax and / or boric acid, especially in the preparation of starch-based glue, or else as a fertilizer in agriculture, between other.

C-Other applications
US Pat. No. 4,332,609 discloses a borated fertilizer comprising a boric acid compound with a monoethanolamine. This document of the prior art is imperfect or even defective, as regards the possibility of a formulation of a highly concentrated solution of boron, comprising the initialization of a borate with the aid of sodium carbonate.

 Without wishing to be bound by the theory, it has been observed in the application for the preparation of starch glue that the physicochemical characteristics of boron in the present invention are identical to those of borates or boric acid.

 In this state of affairs, a variant of the present invention is free from antifers for fertilizing application.

Claims (10)

 1. A boron aqueous solution highly concentrated, characterized in that it comprises: - an expressed theoretical amount of boron trioxide (B203) between 5 and 40%; a borate formed by a carbonate compound chosen from the following products: sodium carbonate, sodium bicarbonate, potassium carbonate and their mixtures; a aminoboron compound formed between a borated product and an alkanolamine compound chosen from the following products: ethanolamine, diethanolamine, and mixtures thereof; an antiferment chosen from the following products: quaternary ammonium, a chlorinated and non-chlorinated isothiazolinone preparation and / or their mixtures; and optionally an additive possessing sequestering or complexing properties with respect to heavy or alkaline earth metal ions chosen from the following products: a polycarboxylic acid or the tetrasodium salt of ethylene diamine tetracetic acid, and mixtures thereof.  2. Solution according to claim 1, characterized in that it is obtained from a highly concentrated borated solute which comprises the following substances: - the carbonate compound is sodium carbonate - the alkanolamine compound is monoethanolamine - the product boré is boric acid.  3. Solution according to claim 1, characterized in that it comprises a quaternary ammonium, preferably alkylbenzyldimethylammonium chloride.  4. Solution according to any one of claims 1 and 2, characterized in that the concentrated boron solute is formed by a mixture of the following composition: - water ------------- 1-20% by weight - boric acid --------- 10-70% by weight - sodium carbonate powder ------- 1-3% by weight

 - monoethanolamine ------- 5-24% by weight <Desc / Clms Page number 12> 5. Solution according to claim 3, characterized in that the weight ratio of boric acid to sodium carbonate is greater than 3, preferably equal to 5.8.  6. Solution according to claim 3, characterized in that the weight ratio of boric acid to monoethanolamine is greater than 3, preferably equal to 4.  7. boron aqueous solution according to any one of the preceding claims, characterized in that it has the following composition by weight by weight - concentrated boron solute ------- 20-98% - antiform ----- ----- 1-10% - sequestering or complexing additive ------ 0-20%.  8. Borate solution according to one of the preceding claims, characterized in that it is free of antiferment and sequestering additive or complexing.  9. Process for the preparation of the aqueous boron solution according to any one of Claims 1 to 8, characterized in that a concentrated borated solute is produced by the solubilization in water of the substances at a concentration of

 temperature between 55 C and 70oC, preferably 63OC.  10. Use of the aqueous boron solution according to any one of claims 1 to 8, in substitution of borax and / or boric acid, especially in the preparation of starch glue, or as a fertilizer, especially in agriculture.