DE2365554A1 - Satin white filler prodn. from silicate, aluminate and sulphate - by hydration of industrial cpds., for use in paper, paint and plastics - Google Patents

Abstract

In the prodn. of a filler based on Ca trisulphoaluminate (I) (3CaO.Al2O3.3CaSO4.32H2O), a prod., contg. silicates (II) contg. Ca, aluminates (III) contg. Ca and CaSO4, is hydrated to give a mixt. of 80-90% ettringite, i.e. (I) and 20-10% tobermorite (IV) (xCaO.ySiO2.zH2O, in which 0.85 x/y 2 and 1 z/y 4). Pref. (II) is Portland Cement, (III) a refractory alumina cement and the CaSO4 is in the form of powdered gypsum. (II) can be hydrated first to a prim. hydrate and then mixed with (III) and CaSO4 in an amt. corresp. to the available (III) or the starting materials can be hydrated together. Used esp. in paper, paint and plastics mfr. The filler can be produced in all forms (dry powder, solns. or suspensions of almost any concn.) from various industrial cpds.

Description

the company Societo Anonyme dite: CIMENTS IAPARGE, 28, rue Emile Menier, Paris lodme / France

concerning:
"Process for the production of fine silk white"

The present invention relates to a process for the production of fine silk white, which is available in various Industries such as papermaking, painting, plastics manufacturing etc. can be used.

It is known that pure silk white is hydrated calcium trisulfoaluminate, which can be obtained either alone or used as part of mixed filler materials.

This mineral filler has good properties in terms of mattness, degree of whiteness, and absorption capacity of ink, etc., which make it one of the well-known better fillers in the paper industry.

Numerous processes for producing a pure silk white are known. The traditional production is described, for example, in the monographs of TAPPI (e.g. No. 30, Chapter 6). Jedooh exist all in producing the silk white by precipitation, starting from aluminum sulphate and slaked lime. Man

509848/0886

In this way keeps various processes for making a very fine precipitate of hydrated Calcium trisulfoaluminate, which is commonly in the form an aqueous dispersion is used. It is advisable to add various additives to this mass are intended to stabilize the crystalline suspension obtained. This mix that mainly consists of hydrated trisulfoaluminate of lime and various Consists of additives, forms the mineral filler, which is used in the boil recipes under the name Silk white is used.

The silk white has the necessary properties to be a good filler when couching; its use for this purpose is described in numerous references, of which, for example, US Pat. No. 3,212,919 is mentioned. The theological properties of suspensions made from casein and silk white are also known. Besides these properties and advantages, it is also known that silk white has disadvantages, which consist in the fact that the aqueous dispersions of silk white are very viscous and it is difficult to disperse with Establish concentrations that exceed levels of more than 20 - 30 % . Furthermore, it can be said that the already increased viscosities, such as the crystallinity that can develop, are also capable of development over time (see TAPPI Technical Association for Pulp and Paper Industry, Vol. 53, No. 3, March 1970).

That is why they were looking for a material that had the good properties of silk white without it Has disadvantages. You already have a pigment composition based on clay and calcium sulfoaluminate,

suggested where the silk white used is obtained from aluminum sulphate, which reacts with lime. Mixtures of other fillers can also be cited, for example
the substances rich in aluminum hydroxide Al (OH) - ,,
(WP WAIDECK, Volume 53, No. 3, TAPPI, March 1970), the
have been suggested to preserve the high qualities of the silk white.

Whatever results are achieved in this way
it appears that the most general use of silk white is limited by its increased manufacturing price, since large quantities of relatively expensive aluminum sulfate are always required in its manufacture.

It is also known that., In the industry, the
deals with hydraulic binders, produces and uses anhydrides which contain calcium-containing aluminates which are soluble in water and capable of self-hydrating or of forming sparingly soluble salt complexes by coprecipitation with other salts. For this
the following calcium-containing aluminates are cited:

3 (CaO) (Al ₂ O ₅ ) and 1
CaOAl ₂ O ₅ and CaO2Al ₂ O,

Even hydrated in hydraulic binders, these calcium-containing aluminates lead to: CaO AlgO- ^ lOHJ), to 2CaO Al ₂ O ₅ 8H ₂ O or to 3CaO Al ₃ O ₅ 6HgO, 4CaOAl ₂ O ₅ IiH ₂ O "(where with η usually is on the order of 12-14)
according to the reaction conditions.

In the area of the same branch of industry relating to hydraulic binders, such as

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from T.D. ROBSON (High Alumina Cements) shows that

A.

Hydration always in the context of the hydraulic binders of composite systems of calcium-containing aluminates and other soluble salts, such as calcium sulfates, which are described in this way to form hydrated Calcium trisulfoaluminate (commonly referred to as ettringite) in the binder.

It is also known that the hydration of Portland cements to form KaMumtrisulfoaluminat in small amounts due to the anhydride of the composition 5 CaO Al 0, which is contained in these cements and hydrates in the presence of gypsum, which is added to avoid false setting of the portland cements will. In the case of the usual binders, the formation of this salt is generally avoided because it has the property possesses to form by creating a destructive expansion. Under these educational conditions will this salt is commonly referred to as candlot salt.

Finally, binders have already been proposed which produce the ettringite in question as the main hydrates (Compare T.D. ROBSON, as mentioned above; Lafuma, ^. Inter. Sympt. Chem. of Cement - London 1952; Budnikov, 4th Inter. Symp. Chem. Of Cement - Washington, 1960).

These various proposals based on systems using a more or less large amount of ettringite have, are intended to provide hydraulic binders by their density and cohesion are characterized, the increased properties in terms of compressive strength in addition to the desired Deliver binding effect.

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In the course of experiments it has been found by the applicant that natural or synthetic products used or manufactured in the indiEbr ie branch relating to hydraulic binders make it possible to produce fine white fillers corresponding to those used in other industries, the the paper industry, the ^A ntrichfarben industry, the plastics industry, etc. needed. This is the general object of the invention, which relates in particular to the production of a filler which has the shape and appearance of the silk white filler and forms the main and mineral part of this filler according to the invention, a filler which is generally known under the name "ettringite".

The invention not only enables manufacture of all manifestations (dry powder, solutions or suspensions in practically large concentrations or Contained), but also the use as a starting component of various industrial compounds, such as Cements containing clay, unfired cements, calcium sulfates as well as hydraulic binders that are not accurate possess the properties of the cements for which they are normally intended to be made.

The process for producing the ettringite or calcium tridulfoaluminate, J> CaO AL ₂ O-, 3 CaSO ₁ ^ 52HgO, is characterized according to the invention in that an approximately stoichiometric mixture which is at a temperature between about 20 and 90 ° C., preferably between 25 and βθ ° C, on the one hand from calcium-containing aluminate (either from the industry relating to aluminum-containing hydraulic binders or produced directly for this purpose) and on the other hand from natural or synthetic, also as white as possible calcium sulphate and water, hydrated at the same time

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the water is added at least in a stoichiometric ratio with respect to the reaction and at most in an amount such that a product is obtained after the reaction which contains 5 % (dry state) ettringite and 95 % (by weight) water.

The formation reaction of the ettringite in stoichiometric proportions is one of the following reactions: the substances that react are introduced in proportions as shown below and which represent the stoichiometric proportions of the reaction. According to the invention it is of interest not to move more than 20 % to one side or the other of the stoichiometric proportions corresponding to the formation reaction according to the invention corresponding to the calcium-containing aluminate mixture.

Reaction (1)

CaOAl ₂ O ₃ + 2 (CaOH ₂ O) + 3 (CaSO ^ 2H ₂ O) + 24HgO

(QaO) ₃ Al ₂ 0 ₃ 3CaS0 ^ 32H ₂ 0 (which is called ettringite),

that is, a mixture of 158 parts by weight of monocalcium containing aluminate, 148 parts by weight of hydrated lime, Carry out 5I6 parts by weight of plaster of paris and 4 ^ 2 parts by weight of water to I254 parts by weight of ettringite.

Reaction (2)

(CaO) ₃ Al ₂ O ₃ + 3 (CaS0 ₂ 2H ₂ 0) + 2βΗ ₂ 0 1 Ettringit.,

that is, a mixture of 270 weight tricalcium containing aluminate, 6516 parts by weight gypsum and 468 parts by weight Water gives 1254 parts by weight of ettringite.

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Reaction (3)

CaO (AlgOOg + 5 (CaOHgO) + 6 (CaSO ₄ 2HgO) + 47HgO g ettringite,

that is, a mixture of 260 parts by weight of monocalcium containing dialuminate, 370 parts by weight of hydrated lime, 1032 parts by weight of gypsum, 846 parts by weight of water 2508 parts by weight of ettringite.

Reaction (4)

12 CaO7AlgO ₃ + 9 (CaOHgO) + 2l (caS0 ^ 2Hg0) + 173Hg ₀

7 "ttringit,

That is, 1386 parts by weight of the specified aluminate, 666 parts by weight of hydrated lime, 3612 parts by weight of gypsum and ~ $ WK parts by weight of water provide 8778 parts by weight of ettringite.

Reaction (5)

CaO6AlgO ₃ + 17 (CaOH ₂ O) + l8 (CaSO ^ 2HgO) + 139 HgO 6 ettringite,

that is to say 668 parts by weight of calcium aluminate, 1258 parts by weight Calcium hydroxide, 3096 parts by weight gypsum, 2502 Parts by weight of water provide 7524 parts by weight of ettringite.

The following substances are understood as calcium-containing aluminates, which have a certain degree of purity be used alone or as a mixture of these substances in any proportions:

3 CaOAlgO ^; 12 CaO7AlgOy CaOAl Oy Ca02Al ₂ '0, j

As calcium sulphate one can indifferently gypsum, ^ 2HgO, Halbyhdrat, CaSO ^ 1/2 HgO, "soluble" anhydride, ^CaS0 4, "dead burnt" anhydride, CaSO ₂ ^, or the natural

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Use a form of this anhydride, called natural anhydride, and mixtures of any of these compounds. One can also use synthetic calcium sulphates, either pure or in a mixture, such as industrial waste products regarding the use of phosphorus fertilizers, fluorine, etc. These latter sulphates lead to the same result, but can only be used under the condition that the impurities, which they contain in non-negligible amounts, are acceptable in industries for which the final filler is determined to be. These calcium sulfates can be either pure or with other salts, such as Be loaded with calcium, magnesium, etc. carbonates.

If a sulfate containing carbonate is used, the reaction product obtained is a mixture of ettringite and calcium carbonate. According to the invention, sulfates are preferably used which contain at least βθ% pure calcium sulfate.

According to a further embodiment of the invention, to facilitate the stoichiometry, unslaked lime or hydrated lime can be added in such an amount that the Ca ⁺⁺ ion which is released keeps the ettringite formation reactions stoichiometrically in equilibrium. According to the invention, hydrated lime or unslaked lime is preferably used, which, to be precise, is called calcium hydroxide or calcium oxide. It can be used neat, but it can also contain variable proportions and even larger impurities, mainly calcium carbonate. It is clear at this point that only the part Ca) OH) _{o of} the mixture (lime and carbonate) leads to a white filler which is a mixture of ttringite and carbonate. According to the invention it is of interest to use mixtures which contain less than 40% carbonate.

509848/0886 - 9 -

On the other hand, it is known that calcium-containing silicates hydrate, indene. them if. Water used in sufficient quantity will provide a mixture of hydrated calcium silicate, hydrated lime, and possibly silicon dioxide. It is also known that Portland cement or its clinker or the "white limes" are rich in calcium-containing silicates which, when hydrated, are a mixture of hydrated lime, Ca (OH) ₂ and tobermorite, CaOy SiO ₂ ZH ₂ O (with 0.85 <x / y <2 and 1 <z / y <4) provide hydrates. The latter mixture is made up of 75-20 % tobermorites, of which 0-20 % is hydrated silica "expressed in SiO ₂ and 25 to 80 % lime.

Another embodiment of the invention looks before to the KaMum ion in at least one of the preceding To deliver reactions 1, ^, 4. and 5, on the one hand:

Calcium-containing aluminates, pure or in a mixture, CaOAlO ,; CaO (AlOj ₉ ; 12 (CaO ') 7 (Al _p 0,), or produced by synthesis or from known refractory alumina-containing binders (e.g. aluminum-containing cements),

and on the other hand:

natural or synthetic calcium sulphates specified above,

Di- or tri-calcium containing alone or in a mixture manufactured silicates or Portland cement (preferably white) in powder form or its clinker or the products to use, which are known as white limes

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509848/0888

and are pure in calcium containing silicates. The commercial form is particularly suitable for the purposes of the invention of powdered artificial white portland cement is excellent.

The process according to the invention then consists "in / that between 20 and 100 ° C a product containing calcium silicates, preferably Portland cement, a product containing aluminates, preferably a refractory cement containing alumina, and" calcium sulfate, for example gypsum, which is broken down in powder form , hydrated and that the constituent or constituents are stirred for the time necessary for hydration and a mixed compound is collected, which on average consists of 8o - 90 % KaMum-containing trisulfoaluminate (ettringite) and 20 - 10 % tobermorites, that is, a compound , which is essentially formed from Efcbringit.

The treatment can be carried out directly on the raw materials mixed in the required proportions.

The hydration can, however, also be brought about first with regard to the product that contains the calcium-containing silicates contains and then provides a primary hydrate; the mixture is then hydrated with the product containing the calcium-containing aluminate and with the calcium sulfate, the The proportions of the primary hydrate correspond to the amount of calcium available for the production of the etrringite Aluminates are determined as part of the above reactions: Finally, the mixture obtained is treated as was set out above.

One of the above calcium sulfates can be used in the above reactions. You can also use lime, CaO, instead of the hydroxide. In these underfedliehen Cases have to be added in quantities of water which were not incorporated into the structure of this hydrate.

509848/0886

~ ^κ "

The amount of water given is the amount that is minimally necessary to obtain ettringite. One can rely on Limit this amount of water, but it is safe to use it according to the ingredients used and accordingly can use the final desired products in greater quantity.

Various examples of mixtures used as further described are given below.

example 1

By practically working according to reaction 2, one part by weight of a mass of 90 % aluminate, 3CaAlpO ₃ and the remainder impurities are mixed with the corresponding amount of water with 2.02 parts by weight of a gypsum of the composition:

CaO 35-36 parts by weight

H ₂ O 18 parts by weight

SO ₃ 59-40 parts by weight

6 parts by weight

Example 2

By working according to reaction 1, one part by weight of a mass of 95 % calcium-containing aluminate, CaO, AlpO _{3 is} mixed with 3.665 parts by weight of the gypsum according to Example 1 and 0.90 parts by weight of lime of the following composition:

CaO 75 %

H ₂ O 23-24% ■

CO ₂ 1 - 2 #.

The minimum amount of water results from the reaction

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1Z

Example 3

One part by weight of a mass containing 88 % aluminate CaO2Al ₂ O is mixed with 4.105 parts by weight of gypsum of the type mentioned above and 1.255 parts by weight of lime of the type mentioned above. The minimum amount of water results from reaction 3 mentioned above.

Example 4

Calcium-containing aluminate mixtures are used as the starting point A to E, which are listed below and which have the specified impurities. You connect Part by weight with the specified amounts of gypsum (or other sulphates) and lime. The minimum amounts of water are light from the above reactions 1 to 5 to ifvote.

Aluminate mixtures of the composition:

ieis p. Verun Al ₂ O ₅
bound CaO CaO lot Plaster like Ca (0H) o pure
worked "53 total verb, m, the aluminum
minatm. in Ex.
1 as in
Example 2 A. 5.5 58 36.5 33 1 part by weight 3.16 0.72 B. 8.5 35 27 24.5 1 dd dd 3.45 0.94 C. 45 49 19th 19th 1 " " 2.08 0.51 D. 8th 72.5 41 ' 34.5 1 dd dd 2.91 0.61 8.9 26.7 26.6 ι tt It 3.22 10.4

It is evident that the use of industrial len products which are mixtures of various calcium-containing aluminates and impurities lead to the formation reactions indicated being linked in such a way that a combination is obtained which gives the best yield in is possible in every case.

509848/0886

The above table is restrictive and permitted the implementation of the invention under all circumstances with simple laboratory tests. The impurities are mostly calcium carbonates, magnesium carbonates, etc., or titanium oxides, iron oxides, etc., or for example small amounts of silicon oxide or aluminum oxide.

Among the instal mixtures particularly suitable for the purposes of the invention, there are included those indicate which correspond to the following compositions in weight points:

M. N 0 P. 1.8 I. 2.5 R. S. T U Insoluble
Components 1 0.75 2 3.25 1.8 6th 0.8 0 TiO ₂ 0.7 2 0.1 3.5 0.1 Fe ₂ O ₃ 0.05 0.0 * 4.5 1 0.5 0.07 SiO ₂ 1 7.5 5 0.2 0.1 2.5 1.2 MgO 1.3 0.2 0.2 11.5 Alkaline
Components 0.15 0.25 1 C , 5 0.3 0.2 fleeting
Components 0.5 0.03 53 55 0.3 4.5 0.24 Al ₂ O ₃ 63 49 32 39 57 55164 | 69 72 CaO 34 4o ^ o 53 (27 | l8 27

Examples of certain possible processes for the industrial realization of the invention are described below represent. The flexibility and the ease of implementation of the method according to the invention can be seen from this, as well as the quality of the products received. In these examples, an aluminate mixture is used accordingly the case C of the table worked.

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236555A

Example 5

12.6 parts by weight of an alumina mixture of type U, 40.6 parts by weight of gypsum of the composition according to Example 1 and 12.2 parts by weight of lime of the composition according to Example 2 are placed in a container provided with a stirring device. The aluminate is a white solid which has been reduced to a very great fineness, for example 4,000 em _o / g

ρ
up to 8,000 cm / g, as is commercially available in the form of refractory, alumina-containing cement.

The stoichiometric amount of water necessary for the formation of ettringite, which is 33 * 6 for the substances mentioned above Parts by weight is supplied, and the mixture thus formed provides 100 parts by weight of ettringite.

In order to facilitate the reaction on the one hand and the preparation of the products on the other hand, additional Water added (that is, that which is not chemically necessary for the reaction). For example, you can too the above mixture of 50 parts by weight of water (the to thick paste) add up to 1,900 parts by weight (which results in a very liquid product).

If you add 650 parts by weight of steep water, you get the reaction between 25 and 60 ° C. The mixture is kept continuously in suspension by stirring. Between 8 and 48 hours, for example after 36 hours, turns under these working conditions apply hydration. A paste is obtained which only contains ettringite with inert substances, which was introduced with the industrial reaction product. You can use the Ettrinigt as it is or dry it to get the product in the form of a white powder.

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It is easy to understand the development of the reaction on the one hand by observing crystallized bodies, their Occurrence or disappearance is followed with X-rays and, on the other hand, with measurements during cement production to monitor the usual techniques of water bound to hydrates.

It is found that in this process the dissolution of the aluminum-containing salt is the slow reaction stage is; therefore, it is practically preferred to make this element very fine in order to accelerate the reaction.

Example 6

The same mixture is prepared as in Example 5, but only the amount of water required for the reaction is used. After several days a pest is obtained which is mainly formed from ettringite, which only needs to be crushed in order to obtain the calcium trisulfoaluminate in the form of a dry powder. The reaction goes here stehr slowly, because the measurements made show that obtained after 24 hours, only 67% of the possible ^E ttringitis. Nonetheless, this remains an acceptable way of obtaining ettringite in dry form.

On the other hand, according to the invention, a faster one is obtained Reaction by feeding in the necessary components in a non-contaminating and comminuting manner, and the reaction as a whole or partially in this environment. For this purpose, you can advantageously use a metal container made of high carbon steel, .Either uncovered or provided with a special coating on the inside, use the corundum - or Porcelain balls is filled. The one educated in this way

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Crusher is used continuously in the mineral body industry. The example described below concerns this embodiment of the invention.

Example 7

A stoichiometric mixture according to Example 5 and then the necessary amount of water so that the weight concentration of the ettringite obtained is 15 to 100 is introduced into a comminution vessel. Nan also introduces corundum balls in the usual amount and the vessel can be rotated at a speed of 70 revolutions per minute for 2K hours. After 2K hours, the X-ray diffraction of the product obtained is examined and it is established that ettringite has been formed and that it no longer contains any anhydrides.

In this way a white paste is obtained which contains very fine particles of calcium trisulfoaluminate, which mineral part of the well-known filler in the paper industry under the name "silk white". This filler can then be supplied industrially in the form of this aqueous dispersion; the excess water can also removed by fully suitable industrial drying and in this way this filler in powder form can be obtained.

If you look at a drop of this solution under a microscope, you can see that all the particles HAVE dimensions below a MICRON! To that

de
In order to better renate the product, it was dried with the aid of hydroscopic solvents, acetone for example, then with ether or by drying at 40 to 60 ° C, after which a few grams of this product, which correctly represent the whole, were removed. A dry powder was obtained which had the following properties which are those of various dry products evident from the above examples.

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Structure: Ettringite (determined by X-ray diffraction) Appearance: white powder

Degree of whiteness in photovolt: (H = 93.5 % for> ( _d = 574.5 rryu refractive index: 1.46

In the case of papermaking, this corresponds to ettringite powder additional the following properties:

specific surface area of the dried and

re-crushed product: 11.21 m / g oil absorption (rub or test): 69 g / 100g

Solubility in water in moles: 0.3 x 10 moles / l Solubility in water (Codex method): 0.64 Solubility in 1/4 normal HDL (Codex method): 26.95 Grain size measurement with a sieve:

<10 / ^u 99.5 %

<5 / ^U 96 %
■ <3 / ^u 81 %

■ Chemical analysis: SiO 1 %

10.5 % CaO: 26.5 %

so, 18.5 %

CO ₂ 1.4 ji

Humidity up to 105 ° ^C '^ loss on fire at 1,000 ° C: 42.80 %, pH value at 10 % in water: 9.8o.

The procedure therefore generally allows the silky white filler to produce at a relatively low price, which is suddenly less time than that used in traditional production, starting from an aluminum sulphate solution and lime can be achieved. The resulting reduction in the manufacturing price therefore makes it possible to

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CrtOÖ /. Ö / riDfiß

The silk white, on the one hand, to gain a place in the paper industry, which by its qualities and not by its Price is stinging, and on the other hand in the formulation of paints itself of denser paints than such used to ground with binders based on plaster of paris, etc.

On the basis of example 7, the product was subjected to tests in order to study the preparative conditions. These experiments described in the examples below have the flexibility and ease of manufacture of ettringite as the main hydrated product according to the process of the present invention was confirmed.

The principle of these experiments is as follows:

The mixture is poured into a vessel according to Example 7. At certain times, a part of the paste is removed and immediately afterwards dried with acetone, then with ether and finally the status of the reaction is checked by X-ray diffraction _{or similar}

The total bound water is also tested on this dried product as the difference between the loss on burning at 900 ° C. and the CO ₂ content, measured by. Calcimetry. Therefore, it should be noted that the mixture comprises 80.9 parts by weight of at 9OO ⁰ C nonvolatiles to 100 parts, of which 72.5 parts by weight hydratable anhydride. The bound water was based on 100 parts of the calcined product. This makes it possible to calculate directly the effectively hydrated part of the hydratable product and also to follow the actual uptake of water from one experiment to the other.

- 20 -

Furthermore, the influence of the following factors on the corresponding test series was investigated:

A. Ratios of dry mix to water before hydration: Assume: A -: 0.1 / 1; A _? : 0.2 / l;

Ay 0.5 / 1.

B. Response time: 2h-4h-6h-8h-24h

B1 B2 B3 'B4 B5

C. Ratio of the crushing bodies in weight with respect to the non-hydrated paste: C-,: 1 - C ₂ : 2 - c ^: 1.5 «

D. Diameter of the crushing bodies:

Dl: 2P mm - D 2: 30 mm - D 3: 50 # each of the two diameters.

E. Reaction temperature:

El: ambient temperature, assumed around 25 ° C. E2: starting material and apparatus brought to 50 ° C. at the beginning of the reaction.

P. Fineness of the aluminum-containing salts used:

p.

Fl: fineness Blaine 3800 cm / g

F2: Blaine fineness 8,000 cm / g

G. Influence of the casting crushing on the color of the product obtained (iron grinder (Gl) or grinder made of porcelain (G2).

After first investigating the grinding times that give the maximum yield, the influence became examined each of these described factors.

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The result is this:

The amount of bound water as a percentage of the calcined water as a function of the reaction time and under the following conditions;

A1.C2-D3.E1.F1 -Gl

theoretical maximum of bound water: 75.9 parts by weight per 100 parts of calcined product.

The results at the various points in time are as follows:

drier, don't

hydrated

Mixing: 2h: 4h: 6h: 8h: 24h:

bound water
on 100 parts of calcined mixture 20.65 35.15 48.65 59.7 60.65 64.10

Yield of collected water
used on 100 parts.
Theoretically bindable water mixture * 100 27.20 46.3 60.35 78.6 79.65 84 ** 4

The yield is calculated as a percentage of the bound water based on the theoretically bindable water, with the latter refers to the fact that the ettringite formed can be represented in the following form:

3 CaOAl ₂ O CaS0 ^ 32

The period of 6 hours corresponds practically and under these conditions to the best economic yield. Egg? will retained for the following experiments;

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§09348 / 0886

a) You start again with the substances from Example 1 and carry out the reaction under the following conditions:

B5-C2-D3-E1 -Pl -Gl This gives the following results:

Al A2 A)

bound water

100 parts of fired mixture 59.7 64,)

b) the constituents of Example 1 are used again and the reaction is carried out under the following conditions:

A1-B3-D3-E1-F1 -Gl You get:

Cl C2 C)

bound water on -

100 parts of fired

Mix 52.5 59.7 54.0

C) the components of Example 1 are taken and carried out the reaction under the following conditions:

Al-B) -Cl-El-Pl-Eq You get:

Dl D2 D)

bound water
100 parts of fired
Mix 49.6 49.2 52.5

" -23 -

/ Λ Q Ö C

d) the constituents of Example 1 are taken and the reaction is carried out under the following conditions:

A1-B3-C2-D3-P1-G1

You get;

bound water to 100 parts of distilled water mixture

El

E2

59.7

66.25

e) you take the components of Example 1 and carry out the
Reaction under the following conditions by:

A 1 - B} - C 2 - D 3 - E 1 -Gl

You get:

Pl

bound water on parts of burnt mixture

59.7

F2

62.96

Example 9

The ingredients of Example 7 are used and the Reaction under the following conditions:

A1.B5-C2.D5-E1.F1

The following whiteness assessments according to G were made (comminuted plaster of paris below 100 / ^u '* ^^ ^e degrees of whiteness were expressed in proportions of color values.

Q = brightness or luminescence factor X = main wavelength P = color unit

5 09 848/0886

Eq G2

Degree of whiteness of gypsum β = 77.1 77.3 %

^X d ^{= 577 m} / ^{u 577} > ^{5 m} / ^u

ρ = 7.4 % 9.1 %

B = 92.8 92.5 %

Degree of whiteness of the ettringite obtained k ^ = 577.5 m , u 577.5 m / U

P = 2.4 % 2.9 fo

Example IO

A mixture according to Example 7 is used, in which the calcium hydroxide is replaced by industrial lime, which is called "Pleur de chaux" and has the following composition Has:

SiO ₂ 0.5 a I %

CaO 75 a 74 ^

H ₂ O 22 a 23 ^

CO ₀ 2 a 3

A comparison of the degree of whiteness of this with that of Example 7 shows:

Lime Example 7 88.5 % 577 m / U 4.15 %

Lime example 10 90.8 % 578 m / a 4.8 %

This lime, which is given for example, can therefore be used without any disadvantage for the preservation of the color shade.

Example 11

This example confirms that the plaster of paris mentioned can be replaced by synthetic plasters used in the manufacture of chemical products:

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lla) by working according to Example 8, that is, under the conditions A ₁ - B ₅ - C ₂ -D ^ -E ₁ - F ₁ , the gypsum used is replaced by phosphogypsum of the composition:

Silica 1 % - CaO ~ $ ~ 5% - H ₃ O 20 % - SO-, 44 % - P ₂ O ₅ 1 % - P 0.5 a I %.

This means that you use the following mixture:

61.8 phosphogypsum

19j42 KaMvim hydroxide of the composition

according to example 2

18.77 % of the mixture U of calculus-containing aluminates.

This mixture contains 82.75 parts by weight per 100 parts of the calcined product, of which 77 * 3 parts by weight hydratable Are anhydrides.

The following ratio is obtained:

bound water = 62.85 % of the calcined product.

Ib) the phosphogypsum is replaced by the fluorofinhydride the composition:

CaO: 42 %

SOy 56 - ° 57 %

F = 1 #

to make the following mixture:

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55.87 fluoro anhydride 22.4 ^ calcium hydroxide of the composition according to

Example 3
21.70 of the calcium-containing aluminate mixture

This mixture contains 94 parts by weight per 100 parts calcined product containing 89.4 parts of hydratable anhydrides. After treatment according to the preparative conditions of the previous one For example, one chooses the following ratio:

bound water = 61.25 % of the calcined product.

lic) the fluoro anhydride is replaced by Silobore gypsum the composition:

CaO 31 - 32 %

H ₂ O 19-20 %

SO ₃ 44 - 415 % SiO ₃ 2 %

B ₂ O ₃ 2 fo,

to obtain a mixture having the following composition:

61.75 % Silobore gypsum 19.45 % calcium hydroxide according to Example 2, 18.80 % white cement of the U type containing alumina.

This mixture contains 83.10 parts by weight of calcined product with 77.45 parts by weight of anhydratable product per 100 parts Anhydride. After treatment according to the preparative conditions of the previous example one obtains the yield:

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bound water = 53 > 10 % of the fired product, lld) the Silibore gypsum is replaced by gypsum from the

CaO: 35 - 36 H ₂ O: 15th - 16 O / ~ \.
3 48 - 49

to make the following mixture:

59 * 75 % gypsum from the Salins du Midi 20.45 % calcium hydroxide according to Example 2 19.80 % aluminum-containing, white cement of type U.

This mixture contains, per 100 parts, 83.35 parts by weight of the calcined product with 81.5 parts by weight of anhydratable anhydride. After treatment according to the preparative conditions of the preceding example ¹ , the yield is obtained;

bound water = 6θ, βθ of the calcined product.

lie) the plaster of paris from the Salins du Midi is replaced by Natural anhydride from Tarascon with the composition:

CaO: 43 + SO ₃ : 50 % CO ₂ :

to make a mixture of the following composition:

59.05 % anhydride

20.80 calcium hydroxide according to example 2 20.15 % aluminum-containing, white cement of type U.

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This mixture contains 82.90 % hydratable anhydride in 93.35 % of the calcined product.

After treatment according to the preparative conditions of the previous example, the yield is obtained:

bound water = 68.80 % of the calcined product.

Example 12

the plaster of paris used according to example 1 and according to the other examples contains 6 % COp corresponding to 13.65 % calcium carbonate.

The lime used according to Example 2 and other examples contains 1 to 2 $ CO _2, corresponding to 2.227 to 3.55 % CaCO

For industrial purposes it can be interesting to start with products rich in carbonate due to the fact that that they are more common and more common. In this context, the following mixture was examined:

Plaster composition 42 parts by weight CaO: 27.9 " SO, 17.6 " co ₂ 12.6 " H ₂ O

This composition corresponds to 40 % CaCO _n for 60 # gypsum.

Likewise, a very carbonate-rich lime of the following composition was used:

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Cao:. 69.8 parts by weight H ₂ O: 17 "
CO ₂ : 13.2 "

of a mixture of 70 wt ^ Ca (OH) ₂ with 30 wt -.% CaCO ^ corresponds.

These ingredients were made with calcium-containing aluminates Type U mixed in stoichiometric proportions of the active elements, that is, the following mixture is prepared Has:

Gypsum (above composition): Lime (""):

Calcium-containing aluminates

of type U:

stoichiometric amount of water :

added water to facilitate hydration:

It was according to Example 8 under the conditions Ap B- ,, C ₂ , υ- ,, E ^, P ^

worked. An aqueous suspension with 2βθ parts by weight was obtained Potassium carbonate, 700 parts by weight of ettringite and 3040 parts by weight of water.

The following are two examples for the preparation of a composition based on ettringite in the main made from lime formed from Portland cement.

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537 Parts by weight 149 dd 100 dd 267 M. 304 0 t!

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ti

Example 12

a) In a ball mill filled with corundum balls, if a white commercial Portland cement is hydrated with the following composition:

SiO ₂ : 23.7 Parts by weight Al ₂ O ₃ : 2.7 SO ₃ : 1.19 dd CaO: 69.3 Il Pe ₂ O ₃ : 0.28 !! fleeting Shares: 1 .80 "

The ball mill was filled to a third of the volume with balls and a third with the mixture of water and cement, the water being 2.5 times the weight of the cement. Finally, a third was released _v to enable the shredding.

The hydration was carried out between 20 and 100.degree. C., for example at 80.degree. C. It was found that the hydration was complete after 13 hours of comminution and that the product formed was 57.5% by weight of tobermorite of the general formula (CaO) ₃ (SiO) ₂ (H ₂ O) ₂ ^ and ^ 2.5 % calcium hydroxide, Ca (OH) _{2 was} formed.

Then the amounts of this mixture were calculated, which in the reaction corresponding to the calcium-containing aluminate it is to be introduced that one prepares for the production of the ettringite.

b) The following ingredients were then mixed:

a refractory, alumina cement (mixture of Calcium-containing aluminates) of the composition:

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50984 870886

ⁱ⁰

Al ₂ O ₃ : 72 Ge important parts 2365554 CaO: 27 I! volatile be
components: 0, 24 t! Pe ₂ O ,: 07 dd
>

which are mainly in the form of CaO AIpO.,; CaO (AIpO-,) _? are combined.

Ais calcium sulfate a naturally broken plaster of paris Composition:

CaO: 35-36 parts by weight

SOy 39 - 40 "
CO ₂ : 6 "

H ₂ O: 18 ",

which is in the form of a fine powder of fineness 4,000 Blaine.

The primary hydrate obtained according to Example 12a.

The ingredients were in a reactor vessel in the following Mixed conditions.

alumina cement: 16.5 parts by weight Calcium Sweet: 63.5 "

primary hydrate: 47.0 "

One of the methods described in Examples 1 to 7 was used, and under the same conditions a fine-grained, inert, white, mineral powder was obtained, which was composed of 162 parts by weight of ettringite and 27.5 parts by weight of tobermorite and 1% of other constituents, parts accordingly mainly 85.5 % calculus-containing trisulfoaluminate and 14.5 % tobermorite was formed.

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Example I3

In the above-mentioned ball mill, the following Mixture of the same ingredients hyaratised:

alumina cement: 16.5 parts by weight

equivalent to $ 14.2 wt

Calcium sulfate: 63.5 parts by weight

k ^ accordingly, J wt -.%

white portland cement: ^ 6.0 parts by weight

corresponding to 31.1% by weight ,

The hydration was carried out as described in Example 7 for 16 hours. At the end of this time, a fine-grain mineral powder in suspension in water was obtained, which was formed from 85.5 % calcium-containing trisulfoaluminate and 14.5 % tobermorite.

After drying according to the known methods for mineral pigments, the powder showed the following properties:

Appearance: dusty white powder. Grain fineness: 100 # <1Ό αχ

Composition: Mixture that mainly consists of

Calcium trisulfoaluminate and tobermorite

is formed accordingly

^ to 32 HgO χ CaO y SiO ₂ ζ (H ₂ (x / y between 0.85 and 2, z / y between 1 and 4).

Actual density of the filler material: 2.06 pH value at 10 % in water: 10.2 Degree of whiteness: 9 ² J- A

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509848/08 8 6

Oil absorption (rub out test :) 65g / 100g Theological property of the aqueous dispersion:

Nixotropy

Composition at 1000 ° C of the production of 85 % trisulfoaluminate residues: 56.5 %

fleeting
Components: 4j5.5 %

of which water: 41.6 %

The above two examples correspond to the preparation of specific mixtures of Tobermorite and Ha Actual Trisulfoaluminate. In view of the limits indicated, one can according to the invention from compounds which mainly calcium sulphoaluminate containing calcium, tobermorite mixtures, hydrated silicon dioxide and calcium trisulfoaluminate included, make in the following proportions:

3I to 2 % tobermorite whose 0 to 4 % silicon dioxide _{is pressed out as SiO 2}

• and 69 to 98 % hydrated calcium-containing trisulfoaluminate (silk white).

According to the invention, the powder or paste of the examples is a mineral filler with very interesting Synthesis for all industries that use these products and especially for the paper industry (filler and · Gautschen), the production of watercolors, organic paints, mastics and wall paints, Fertilizers, pharmaceutical products, etc. The products can be liquid.

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-χ

The following examples describe the results obtained with the products according to the invention in FIG Papermaking and parbing can be obtained can.

I. Papermaking

a) To demonstrate the performance of the dry extract compared to that of the invention as a filler a trad id ioneile η silk white is applied ,, were under the best possible conditions and while optimizing the amount of the corresponding each pigment zugezugte.ι Dispersing agent, aqueous dispersions of the same viscosity produced:

Content of dispersion content of dry

kenem material for 500 centipoise

middle:

TRADITIONAL
Silk white

according to the invention
filler

0.6 0.5

29 % 48 %

b) The following couch masses were produced according to the usual processes of the paper industry:

Recipe A. Recipe B Recipe C kaolin usual
Silk white inventive
m. filler Amount of filler 40 wt. 40 wt. 40 parts by weight Amount of dry starch 3.6 " 4.4 " 4.4 " Amount of tr. Disper
dissolving agents 0.16 " 0.24 " 0.20 " Amount of tr. Vinyl
naremulsion 3.6 " 4, 1 " 4.4 " Amount of water 52.64 " 51 51

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For the production according to these recipes there are diagrams To make remarks:

For recipes A and C, the amount of filler material is dispersed in the water added to the dispersant according to:

I. dry

Water: 38.24 parts by weight

Dispersant: according to the recipe

drier
Filler: 40

The dispersion of Recipe I can be easily made for example in a slowly rotating mixer. Then Part II of the recipe adds:

Strength at 2o ^ '18

Latex at 50 % 7.2

In contrast to this, in the case of recipe B (previously the usual filler), first a dispersion of part I produce:

Water: 29 parts by weight of ² JO

Dispersant: according to the recipe

Strength at 20 %: 22 of which water 17 * 6

Silk white: 4o

This previous measure is due to the high viscosities of the usual silk white compared to his Dispersions necessary; it is necessary to disperse this silk white in a preparation which already contains starch; which takes up a larger amount of water in the dispersion. Despite

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these precautions, the dispersion remains difficult because their dry extract of silk white 46 percent - has%, after which you can only add the rest of the specified Rezepetes..

The cheesy masses produced in this way have the following properties:

recipe A. B. C. Viscosity Broofield at 100 tr / mn. 112 cp 450 cp 220 cp PH value 6.5 9.7 10.1 Water retention 15th 12th 19th

Applied to normal Afnor Vll paper, these result Masses the following results:

recipe A. B. C. Appearance silky silky brilliant Weight amount d, he Be
layering g / m surface 12th 12th 12th Whiteness degree 81.6 87.9 89.4 Opacity % 97.6 89 89 Efficiency of the opti
blue discoloration 2.4 5.3 5.8

The great advantages of the filler according to the invention when used for couching paper in terms of the results the usual silk white are obviously similar to silk white (calcium trisulfoaluminate) it has the excellent Properties of this product, it produces the same or better optical qualities, it possesses

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509848/08 86

3 * 36

a good water retention system. Furthermore make it possible its rheological properties that it corresponds to the usual processes of the paper industry can be used and prepared without special precautions.

c) The filler according to the invention can be mixed with Kaolin is used as it is in manufacture in the paper industry is more common; one makes Gautschmassen of the same recipe as in Example Ib with the following mineral Ingredients of the mixture;

Recipe D E F

Composition of

Fu]] substances kaolin 100 % kaolin 80 % kaolin 80 %

Silk white filler

20 fo according to the

• Erf , 20 %

This will be done with no difficulty or special precautions performed.

Applied under the same conditions deliver this Masses the following result

recipe D. E. F. Weight amount of the
brought coating
g / m surface
Degree of whiteness %
Opacity % 15th
82.2
88.3 15th
85.3
89.1 15th
85.4
89.2 Ι! » Paints

- For a paint for inside or outside based on a Part I of vinyl resin emulsion is produced

- 38 -

Parts by weight

Protective holloid of the methyl 0.3 type Water 23

ionic dispersant

(STABIRON (Societe PROTEX) 0.1

In the mixtures I and II, the dispersed quickly Fillers:

Weight texle Filler according to invention 20.0 Titanium, rutile 6th barium sulfate 5.2

While stirring gently, add:

Vinyl resin emulsion with

50 % dry matter 31.2

Dibutyl phalate 1

Ethyl glycol 2.2

Turpentine essence 0.3

Water for viscosity 10

99.3

This paint has a dry content of 47.2 while its pH value is 10.1 without adjustment. It is very stable over time, as the following observations show:

Time 0 1 Day 7 days 3 months viscosity
(Brookfield
100 tr / mn)
PH value 550 cp
10.1 585
10, cp
0 58O cp
9.9 578 cp
10

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After this time it is found that, despite the presence of barium sulphate, there is no sediment in the paint has been formed.

The filler has an overall thixotropic property which enables easy application.

It should be noted that non-white cements can be used as a valid product obtained that has no special color purity.

The present invention therefore provides the means necessary to increase the uses of conventional silk white with flexibility and simplicity of manufacture which is remarkable and at a price below those of the known Procedure lies. In particular, there is the advantage due to the expanded manufacturing possibilities that in each Case the ideal filler can be chosen.

- patent claims -

50 9 8 48/0886

Claims (7)

Claims 1) Method of making one mainly from calcium trisulfoaluminate existing filler, characterized in that a product containing calcium-containing silicates, a Product containing calcium-containing aluminates, and calcium sulfate hydrated to obtain a mixture that on average consists of 80-90% ettringite and 20-10% tobermorites. 2) Method according to claim 1, characterized in that the product containing calcium-containing silicates is Portland cement used. 3) Process according to claim 1 or 2, characterized in that the product containing calcium-containing aluminates is a Refractory alumina cement used. 4) Method according to one of claims 1 to 3, characterized in that that powdered plaster of paris is used as calcium sulfate. 5) Method according to one of claims 1 to 4, characterized in that that the product containing the silicates is hydrated and the primary hydrate thus formed with it caiζiumhaltigern JÜJuminat and calcium sulfate is mixed, whereby the proportions of the primary hydrate according to what is available calsium-containing aluminate can be selected. 509848/0886 6) Method according to one of claims 1 to 5, characterized in that that the starting substances are hydrated at the same time. 7) filler, especially for use in papermaking and for paints, characterized in that it consists of 80 - 90% calcium-containing trisulfoaluminate and 20 - 10% Tobermorites exist. 509848/0886