FR2596754A1 - Additives delaying the setting of plaster and of plaster-based compositions and plaster and plaster-based compositions containing them - Google Patents

Abstract

An additive for plaster and plaster-based compositions. This additive consists of water-soluble phosphonomethylated polyalkoxylated polyamines and/or of water-soluble salts of these polyamines. Application in the plaster industry.

Description

 The present invention relates to additives which retard the hardening of the flat and to plaster and plaster based compositions and plaster-based compositions containing them.

Plaster, a cheap product, easy to manufacture, with a very wide supply, could, thanks to its specific characteristics:
- flame retardant properties,
- regulating properties of the hygrometric degree (it absorbs or restores the water vapor),
- thermal insulation properties (conductivity factor is 0.4 Kcal / mh0C),
- soundproofing properties, constitute a quality bonding material and construction if, in use, it had a number of serious disadvantages, the most grueling is a speed of setting much too fast.

 Indeed, the plasters tend to harden, that is to say set, very quickly after mixing with water. The curing mechanism consists of a hydration of most of the hemihydrated calcium sulphate ( SOqCa.Q H2O) to dihydrate (SO4Ca.2H2O) in aqueous suspension, which leads to the formation of a coherent mass by "entangling" the crystals of the dihydrate. In addition, the speed of setting is even greater than the amount of water is closer to the amount required for hydration alone and also that the grind is thinner. This amount of water is of the order of 25% of the weight of plate. So practically the plaster is stripped with a very large excess of water to avoid a catch too brutal and allow its implementation.Despite this artifice, however, we can prepare and apply only small amounts of plaster in a time interval necessarily in short, with the additional inconvenience of this large excess of water, obtaining a binder which, once dry, will be very porous and not very resistant mechanically.

 For example, the building, building materials, and sculpture industries, which use gypsum plaster or hydrochloride plaster on a large scale, alone or mixed with lime, sand and aggregates. light, such as perlite and cellulose derivatives, wish to extend the setting time of their compositions.

 There have already been many attempts to lengthen the setting time, but none has given a completely satisfactory result because of side effects quite often very troublesome. For example, add tartaric acid to increase the setting time.

However, the effect that can be obtained in this way is not very great. It is also possible to add hydrolysates of proteins of animal or vegetable origin. But protein hydrolysates are complex mixtures whose composition depends on the one hand the raw materials used (whose regularity is not the main quality) and hydrolysis processes which, in general, are poorly mastered, which leads to at non-constant retarding efficiencies that can vary considerably from one operation to another. Moreover, retarders of this type generally have very strong characteristic odors, poor storage stability, they contribute to the formation of foam during the operations of preparation and use of the binder, and very often they cause molds as well. In addition, retardants, such as phosphoric or citric acid, sodium hexametaphosphate, magnesia, require either a greater amount of mixing water than plaster. pure consistency (constant fluidity), or later cause changes in the final properties of the plasters thus treated, such as the appearance of blooms or blisters, lack of adhesion and even the destruction of the finishing paints applied on plaster
On the other hand, there have already been some attempts to reduce the amount of water in the dish, so that when it is desired both to delay the setting of the plaster and to decrease its amount of In the case of storage water, it is necessary to use two specific products: a retarder and a fluidifying agent or water reducing agent. Their harmful side effects most often add up instead of retreating, and, very often, the fluidifying agent comes to thwart the action of the retarder setting, hence the need to put a higher dose to obtain the same effect delay, all this resulting in a very significant increase in the cost price of plaster thus treated.

 The Applicant has now discovered that the addition of certain very low-level substances derived from residues or by-products of manufacture of the chemical industry to the mixing water of plaster or other preparations made from gypsum Other binders (lime for example) or aggregates (for example sand, stone powder, perlite, cellulose derivatives), allowed to obtain significantly longer setting times while decreasing the amount of mixing water. The term "plaster" should be understood as encompassing any product obtained by dehydration and more or less spraying of natural or artificial raw materials consisting essentially of calcium sulfate hydrate.

 In particular, it has been found that certain by-products of the manufacture of amino-alkoxyamines and their higher derivatives having undergone phosphonomethylation treatment can be used as hardening-retarding additives for gypsum plaster or anhydrite products. .

It is known that the manufacture of aminoalkoxyamines and their higher derivatives from polyamines of the general formula
NH 2 --CH 2 --CH 2 - 4 NH - CH 2 2 CH 2 n NH 2 in which n is an integer between 0 and 5, makes it possible to obtain not only monoalkoxylated derivatives, but also polyalkoxylated derivatives whose proportion varies naturally from one process to the other. Until now, these compounds have been regarded as by-products that are difficult to use because of their very dark color and their lack of interest in other syntheses.

 The Applicant has found that a simple phosphonomethylation treatment makes it possible to valorize these by-products by rendering them useful as additives retarding the hardening of the plate or of compositions based on plaster or anhydrite.

où n est un nombre entier de O à 5,
x est un nombre entier de 2 à 6,
y est un nombre entier de 2 à 6,
R1 est choisi parmi-les groupes - CH2 - CH2 - OH,

More specifically, the subject of the present invention is an additive for the plate and gypsum or anhydrite plaster-based compositions, characterized in that it consists of water-soluble polyalkoxylated polyalkoxylated polyamines of the general formula:

where n is an integer of 0 to 5,
x is an integer from 2 to 6,
y is an integer from 2 to 6,
R1 is selected from - CH2 - CH2 - OH groups,

R2 is selected from - CH - CH2 - OH,

est choisi parmi les groupes - CH2 - CH2 - OH,

is selected from the groups - CH2 - CH2 - OH,

et/ou de sels solubles dans l'eau de ces polyamines polyalcoxylées phosphonométhylées.<tb><SEP> O
<tb><SEP> - <SEP> CH2 <SEP> - <SEP> PUT <SEP> OH
<tb><SEP> OH
<tb> R4 <SEP> is <SEP> a <SEP> group <SEP> - <SEP> CH2 <SEP> - <SEP> P <SEP> t <SEP> OH <SEP>,
<tb><SEP> OH
<Tb>
R5 is selected from - CH2 - CH2 - OH,

and / or water-soluble salts of these phosphonomethylated polyalkoxylated polyamines.

Examples of compounds of formula (1) according to the invention that may be mentioned include the residues of the manufacture of aminoethylethanolamine, having undergone phosphonomethylation. Thus, in this category, two typical additives I and II according to the invention have as composition by weight
Additive (I) Additive (II)
Derivative containing an ethoxylated group and 3 groups 17% 0% methylenephosphonic
Derivative containing 2 ethoxylated groups and 2 groups 53% 63% methylenephosphonic
Derivative containing 3 ethoxylated groups and 1 group 19% 23% methylenephosphonic
Tetraethoxylated derivatives 11% 14%
Although generally, all of the water-soluble salts of the phosphonomethylated polyalkoxylated polyamines can be employed in the compositions according to the invention, the sodium salt is preferred. However, other alkali metal salts such as potassium, lithium, and the like. .., as well as mixtures of alkali metal salts, can be substituted between it. In addition, all the water-soluble salts, such as ammonium salts and amine salts, which have characteristics similar to the alkali metal salts, can be used in the practice of the invention. amine salts prepared from low molecular weight amines, that is, having a molecular weight of less than 300, such as, for example, alkylamines, alkylene amines, and alkanolamines containing not more than two amine groups such as ethylamine, diethylamine, propylamine, propylene amine, hexylamine, 2-ethylhexamine, monoethanolamine, N-butyl ethanolamine, triethanolamine.

 The additive according to the invention can be used in the form of dehydrated powder, or in the form of an aqueous concentration solution of up to 60 to 70%, as the case may be.

 The addition to the plaster, or flat-based composition, may be 0.01 to 2 phr (part per cent), preferably 0.05 to 1 phr, of dry additive to plaster. . It also depends on the hardening delay that is to be imparted in this case.

 The additives according to the invention can either be pre-mixed with dry plaster when they are in the form of powder, or added in the mixing water when they are in liquid form, or in the form of diluted solution when the dosage is too difficult to achieve at the original concentration.

 These additives can be used in plaster alone or in combination with other auxiliary agents (water-repellent, fungicidal, foaming, dyestuffs) or with other binders (lime for example) or with mineral or organic aggregates (sand, stone powder, perlite, cellulose derivatives) for the purpose of producing either a concrete, a mortar, or various coatings.

 The present invention will also be better understood with the aid of the following nonlimiting examples which illustrate the improvements obtained using the compositions according to the invention.

 In these examples, parts per cent are by weight unless otherwise indicated. All the tests were carried out with plaster of construction called symbolically "PFC2" according to the French standard NF / B 12 301.

EXAMPLE 1. Synthesis of the additive (I)

Charge to a reactor equipped with a stirrer, a thermometer and a refrigerant
55% technical phosphorous acid 220 g
Water 3OOg
Then, at a temperature below 400 ° C., 130 g of a residue (A) from the manufacture of aminoethylethanolamine, having as compositions by weight:
Monoethoxylated derivative of ethylene diamine 9%
Diethoxylated derivative of ethylene diamine 45% Residue
Triethoxylated derivative of ethylene diamine 25% A
Tetraethoxylated derivative of ethylene diamine 21%
Then heated to 1050C and introduced in about 2 hours
30% Formalin 121 g
Then we stay 4 hours at 105 C.

It is cooled under vacuum to 600C and concentrated under reduced pressure to remove unreacted formalin.

It is cooled to 200C.

704 g of product (I) having a solids content of 38% are then obtained.

EXAMPLE 2 The technical phosphorous acid of the preceding test is replaced by 38% phosphorous acid recovered from the manufacture of a fatty acid chloride (for example, a dichloride). We charge:
38% recovery phosphorous acid 248 g
250 g water
Then at a temperature below 400C, is introduced 110 g of residue (A) identical to that of Example 1.

It is heated to 1050 ° C. and introduced in about 2 hours.
40% Formalin 87 g
Then we stay 4 hours at 1050C.

Cooled to 800C, and concentrated under reduced pressure to remove excess formaldehyde.

540 g of additive (I) having a dry matter content of 42% are then obtained.

EXAMPLE 3 246 g of the product (I) obtained in the preceding example are used and neutralized with sodium hydroxide to reach pH = 7.8. It takes 108 g. 354 g of a perfectly clear solution of directly usable additive are thus obtained.

EXAMPLE 4. Synthesis of the Additive (II)

In a reactor equipped as in Example 1, the following are charged:
Technical phosphorous acid 68% 200 g
400 g water
Then at a temperature below 400 ° C., 200 g of the residue (B) from the manufacture of aminoethylethanolamine having the composition by weight of:
Monoethoxylated derivative of ethylene diamine 0%)
Diethoxylated derivative of ethylene diamine 48% Residue
Triethoxylated ethylene diamine derivative 27%
Tetraethoxylated derivative of ethylene diamine 25%
Then heated to 1050C and introduced in about 2 hours
37% Formalin 135 g
Then we stay 6 hours at reflux.

Cooled to 800C and concentrated under pressure
pick to remove excess formalin.

We then obtain 710 g of product (II) having a content
in dry matter of 50%. at
EXAMPLE 5 In a reactor equipped as in Example 1,
charge
Phosphorous acid recovery 38% 471 g
of example 2
Water 480 g
Then at a temperature below 400 C, 264 g are introduced
of residue B, identical to that of Example 4.

It is heated to 102 ° C., and introduced in one hour
Formalin 33% 200 g
Then we stay 4 hours at reflux.

Cooled to 800C and concentrated under reduced pressure
to remove excess formalin.

It is then neutralized with an aqueous solution of ammonia
at 20% recovered from the EDTA synthesis.
350 g for pH = 7, and finally 1300 g of
the ammonium salt of the additive (II) can be used
ment.

EXAMPLE 6 In a reactor equipped as in Example 1,
we charge
Phosphorous acid recovery at 38%
the example 2 989 g
Water 266 g
Then at a temperature below 400C, we introduce
417 g of residue A identical to that of Example 1.

It is heated to 1070C and introduced in about 2.5 hours
44% Formalin 312 g
Then we stay about 7 hours at 107-7100C,
The product is cooled to 600C and is concentrated under
reduced pressure to remove excess formalin.

of the
It is then neutralized with / monoethanolamine to a pH of about 8: 1010 g are necessary.
Finally, 2800 g of aqueous solution of the salt of
monoethanolamine additive (I) directly usable.

EXAMPLE 7 In a reactor equipped as in Example 1 is charged
38% recovery phosphorous acid
of Example 2 345 g
500 g water
Then at a temperature below 300C, 250g of residue is introduced from the oxybutylenation of propylene diamine. Then heated to 1050C and introduced in about 2 hours
40% Formalin 120g
Then we stay 6 hours at 105 C.

Cooled to 60 C, and concentrated under reduced pressure to remove excess formaldehyde.

850 g of an additive according to the invention having a dry matter content of 47% directly usable are then obtained.

EXAMPLE 8 In a reactor equipped as in Example 1, one charges
38% recovery phosphorous acid
of Example 2 690 g
700 g water
Then at a temperature below 30 ° C., 311 g of residue originating from the oxypropylenation of tetraethylene pentamine are introduced. Then heated to 1050C and introduced in about 2 hours
30% Formalin 320g
Then we stay 12h at 105 C.

Cooled to 800C and distilled under reduced pressure to remove excess unreacted formalin.

It is cooled to 20 ° C. and neutralized to pH = 7 with an aqueous ammonia solution identical to that used in Example 5. This requires 850 g. In this way, 2500 g of solution of an additive according to the invention can be used directly.

EXAMPLE 9 In each of the tests of this example, "PFC 2" plaster is capped with 20 + 100 water containing increasing doses of phosphonomethylated polyalkoxylated polyamine additives according to the invention and non-compliant polyalkoxylated polyamines. according to the invention, that is to say having not undergone the simple treatment of phosphonomethylation. The amount of water relative to the plaster is determined so that a defined volume of the mixture gives a determined spread. On the mixture thus obtained, the start of setting is then determined according to a method adapted from the French standard NF / B 12401, paragraph 2.321: start of setting.

 at. Consistency tests.

 160 g of water are weighed at 20 ± 1 ° C. in a beaker; 200 g of plaster 'tPFC 2' in another (water / plaster ratio (E / P) = 0.80 at the start) The plaster is poured into the water in less than 30 s with stirring. obtained in a stainless steel cylinder with an inside diameter of 50 mm and a height of 50 mm placed on a glass plate, the surface of the plaster is leveled at the upper level of the cylinder, and after 15 seconds of waiting, the cylinder is lifted abruptly; The paste is spread out, and the aim is to obtain a slab, the average of which has two perpendicular diameters between 15 and 16 cm.If this is not so, the amount of water is modified in the appropriate direction.

 b. Beginning of catch.

 The start of the conditioned chamber (20 + 10C, 65% RH) is determined on the dough cake of suitable consistency (15 cm (diameter D 16 cm).

For this, at regular intervals, we slightly pass a knife blade (maintained in a vertical plane) and it is considered that there is beginning to take when the lips of the cut do not close. The duration of start of setting is counted from the contact between plaster and water.

Additives used:
Additive (I) of Example 1: residue of the manufacture of aminoethylethanolamine having undergone phosphonomethylation (according to the invention).

 - Residue (A) of Example 1 of the manufacture of aminoethylethanolamine.

 Additive (II) of Example 4: residue of the manufacture of phosphonomethylated aninoethylethanolamine (according to the invention).

 Residue (B) of Example 4 of the manufacture of aminoethylethanolamine.

The results are shown in the table
I below.

 As can be seen from this table the residues of the manufacture of aminoethylethanolamine having undergone phosphonomethylation (according to the invention), exert some fluidifying action in the plaster (they substantially reduce the amount of water required to obtain a fixed consistency) moreover they increase in a rather important way the duration of start of setting.

On the other hand, the same residues which have not undergone the phosphonomethylation treatment do not exert any of these two actions in the plate.

TABLE 1
Tests Additive Dose E / P Ratio for Start Time
N ppc of matter have a con-
dry / plaster tance fixed minutes
15cm <D <16cm
1 O (pure plaster) 0.860 25
ADDITIVE: Additive (I) according to the invention
2 0.025 0.835 95
3 0.050 0.825 140
4 0.100 0.815 240
5 0.200 0.805 960
ADDITIVE: Residue (A)
6 0.025 0.860 25
7 0.050 0.860 27
8 0.100 0.855 30
9 0.200 0.855 30
ADDITIVE: Additive (II) according to the invention
0.025 0.845 100
he 0.050 0.835 150
12 0.100 0.830 260
13 0.200 0.825 1020
ADDITIVE: Residue (B)
14 0.025 0.860 25
0.050 0.860 25
16 0.100 0.860 27
17 0.200 0.855 30
EXAMPLE 10

 In each of the tests of this example, the plaster "PFC 2" is mixed with water at 20 ± 1 ° C, containing increasing doses of additives consisting of soluble salts of polyalkoxylated polyamino phosphonomethylated polyamines according to the invention. obtained are evaluated according to the same principles and the same operational methods as in example 9.

Additives tested t
Sodium salt of the product (I) of Example 3 residues from the manufacture of aminoethylethanolamine having undergone phosphomethylation (according to the invention).

 - Ammonium salt of the product (II) of Example 5: residues of the manufacture of aminoethylethanolamine having undergone phosphomethylation (according to the invention).

 - Monoethanolamine salt of the product (I) of Example 6: residues of the manufacture of aminoethylethanolamine having undergone phosphonomethylation (according to the invention).

 - Ammonium salt of Example 8: residues of the manufacture of the oxypropylenation of tetraethylene pentamine, having undergone phosphonomethylation (according to the invention).

 The results are shown in Table II below.

 This Table II clearly shows that the addition to the gassing water of the gypsum of various water-soluble salts of residues from the production of polyalkoxylated polyamines having undergone phosphonomethylation according to the invention makes it possible to obtain start of setting strongly increased, at the same time as a reduction of the amount of water necessary to obtain a fixed consistency.

EXAMPLE 11

 In each of the tests of this example, measurements of the setting time of taps are carried out on mixtures of water and plaster without lime, on the one hand, and of flat with 5% of lime, on the other hand, containing increasing doses of phosphonomethylated polyalkoxylated polyamine additives according to the invention and polyalkoxylated polyamines not in accordance with the invention, that is to say having not undergone the simple treatment of phosphonomethylation, and of soluble salts of polyamines polyalkoxylated according to the invention.

TABLE II
Tests Additive Dose .: E / P ratio for Start Time
N ppc of matter have a con-
dry / plaster tance fixed minutes
15cm <D <16cm
18 0 (pure plaster) 0.860 25
ADDITIVE: sodium salt of the product (I) according to the invention
19 0.025 0.840 90
0.050 0.830 130
21 0.100 0.820 225
ADDITIVE: Ammonium salt of the product (II) according to the invention
22 0.025 0.850 70
23 0.050 0.845 105
24 0.100 0.840 180
ADDITIVE: monoethanolamine salt of the product (I) according to the invention
25 0.025 0.845 75
26 0.050 0.835 105
27 0.100 0.830 185
ADDITIVE: ammonium salt of Example 8 according to the invention
tion
28 0.025 0.850 60
29 0.050 0.840 95
30 0.100 0.835 160
The mixtures thus obtained are evaluated as regards the starting time of setting, according to the same principles and the same procedures as in example 9.

 - Product (I) of Example 2: residues of the manufacture of aminoethylethanolamine having a phosphonomethylation according to the invention.

 - Residue (A) of Example 1: residues of the manufacture of aminoethylethanolamine.

 Sodium salt of the product (I) of Example 3: residues of the manufacture of aminoethylethanolamine having undergone phosphonomethylation according to the invention.

 - Product of Example 7: residues of the manufacture of the oxybutylenation of propylene diamine having undergone phosphonomethylation according to the invention.

The results are recorded in the table
III below.

 These results show again that the residues of the manufacture of polyalkoxylated polyamines having undergone phosphonomethylation according to the invention, whether they are used as or in salt form, considerably lengthen the setting times of the plaster used alone or mixed with small amounts of lime.

It goes without saying that the embodiments described are only examples and could be modified, in particular by substitution of technical equivalents, without departing from the scope of the invention. TABLE III
Tests N ADDITIVES Dose ppc in Start time in minutes dry matter / plaster binder without plaster with 5% lime lime 31 Nil: WITNESS 0 25 38 32 Product (I) 0,020 65 55 33 according to the inven- 0,040 120 105 composition 0.060 165 135 35 0.080 190 145 36 0.020 25 38 37 Residue (A) 0.040 27 40 38 0.060 27 40 39 0.080 28 42 40 sodium salt 0.020 60 50 41 of the product (I) 0.040 115 100 42 according to the invention 0.060 155 125 43 0.080 180 140 44 Product 0.020 55 48 45 Example 7 0.040 105 95 46 According to the invention 0.060 150 115 47 tion 0.080 170 130

Claims (9)

 R1 is selected from the groups - CH2 - CH2 - OH,  y is an integer from 2 to 6,  x is an integer from 2 to 6,  where n is an integer of 0 to 5,

 An additive for plaster and compositions based on gypsum or anhydrite plaster, characterized in that it consists of phosphonomethylated polyalkoxylated polyamines, soluble in water, of the general formula:

 is selected from the groups - CH2 - CH2 - OH,

R2 is selected from - CH2 - CH2 - OH,

 and / or water-soluble salts of these phosphonomethylated polyalkoxylated polyamines.

R5 is selected from - CH2 - CH2 - OH, R4 is a  2. Additive according to claim 1,  characterized in that it is in the form of salts of  alkaline levels, ammonium salts or amine salts,  3. Additive according to claim 2, carac  terized in that it is in the form of sodium salts  4. Additive according to any of the  I to 3, characterized in that it is under the  form of a plaster or premix premix powder  based on plaster.  5. Additive according to any of the claims  1 to 3, characterized in that it is in the form  an aqueous solution to add to the mixing water.  6. Process for retarding the hardening of the  plaster or a composition based on plaster, characterized  in that it is added to the plaster or the base composition  plaster and / or their mixing water, an additive such as  defined in any one of claims 1 to 5.  7. Process according to claim 6, characterized in that 0.001 to 2 parts of additive are added per 100 parts of plaster.  8. Process according to claim 7, characterized in that 0.005 to 1 part of additive per 100 parts of plaster is added.  9. Plaster and compositions based on plaster, characterized in that they contain an additive according to any one of claims 1 to 4.