DE2037586C3 - Plaster of paris - Google Patents

Description

π
Χ, Υ

Ri and R ₂

: oh /

R _n -NICP = O (1)

OHy ₃ -.
R ₁ R ₃ OH

N-C-P = O (II)

/ i \
R ₂ R ₄ OH

Ooderl

H or an alkyl radical with 1 to 4 carbon atoms

H or an alkyl radical with 1 to 4 carbon atoms

H or an alkyl, cycloalkyl or aralkyl radical with 1 to 10 carbon atoms
H, an aryl or an alkyl radical with 1 to 4 carbon atoms
H or an alkyl radical having 1 to 4 carbon atoms or -PO ₃ H ₂ , optionally in the form of the water-soluble salts.

10

15th

The invention relates to gypsum masses with delayed setting time, which have an additive to certain Aminophosphonic acids, optionally in the form of the water-soluble salts.

Plaster of paris in the form of burnt plaster or plaster of paris alone or in a mixture with lime, sand, Lightweight aggregates such as perlite and cellulose derivatives are used in construction and in sculpture used to a greater extent. The setting time after mixing the named products with water is however, it is relatively short, so that rapid processing must be carried out. However, in many cases it would be one Extension of the setting time is desirable.

You therefore have to set the plaster of paris with additives of various kinds such as glue, dextrin, borax-aluminum sulfate and phosphates delayed. However, the organic substances mentioned have the disadvantage that they clog the pores of the gypsum and also mold or decompose in the course of the Can evoke time. The inorganic substances set - as they are in relatively large quantities must be added - in part, the strength of the plaster of paris is significantly reduced and in part give rise to it to efflorescence on the surface of the plaster of paris. Therefore, phosphoric acid was used together with Citric acid used in small quantities can be the opposite of the start of setting Work without additives can be delayed 2 to 3 times. Another improvement is the use of polyoxycarboxylic acids as an additive, which achieves setting times of about 60 to 145 minutes will.

Finally, one already has synthetic aliphatic polyamino-polycarboxylic acids with 3 to 9 carbon atoms or their salts are used as an additive to plaster of paris to increase the setting time significantly. However, it has been shown that in the case of plaster of paris, which contains additions of hydrated lime, the setting times can be significantly reduced.

It has now been found that excellent setting times are obtained, also in the case of Stucco plaster with the addition of hydrated lime good values can be achieved if you look at the following means described. The gypsum masses, in particular stucco plaster, are characterized by a Content of aminophosphonic acids of the general formula I and II

25th

30th

2. Gypsum masses according to claim I, characterized by a content of aminophosphonic acids Formulas I and II in amounts from 0.03 to 5% by weight.

3. Plaster of paris mass according to claim 1 in the form of plaster of paris, characterized by a content of Hydrated lime.

R _n -N-

'X OH ^X

-C-P = O

I \

Y OH

(D

R ¹ R ₃ OH

N-C-P = O

R ₂ R ₄ OH

η
X, Y

Ri and R ₂
R ₃

50

55

60

65 Ooderl

H or an alkylresl with 1 to 4 carbon atoms

H or an alkyl radical with 1 to 4 carbon atoms

H or an alkyl, cycloalkyl or aralkyl radical with 1 to 10 carbon atoms
H, an aryl or an alkyl radical with 1 to 4 carbon atoms

H or an alkyl radical with 1 to 4 carbon atoms or - PO3H2, optionally in the form of the water-soluble salts.

Examples of compounds of the formula I are in particular aminotri (methylenephosphonic acid) and Methylaminodi- (methylenephosphonic acid) should be mentioned. Particularly suitable aminophosphonic acids of the general Formula II are

Aminomethanephosphonic acid,

Ν, Ν-dimethylaminomethanediphosphonic acid,

Ν, Ν-dibutylamino-methanediphosphonic acid,

N.N-dioctylaminomethanediphosphonic acid,

N-methylarhinomethanediphosphonic acid,

N-butylaminomethanediphosphonic acid,

N-hexylaminometan diphosphonic acid,

N-cyclohexylaminomethanediphosphonic acid,

N-benzylaminomethanediphosphonic acid,

l-aminoethane-l-diphosphonic acid, 1-aminobutane-1,1-diphosphonic acid, 1-amino-1-phenylmethanediphosphonic acid and Ν, Ν-dimethyl-1-aminoethane-1,1-diphosphonic acid.

Instead of the phosphonic acids mentioned, the corresponding water-soluble ones can optionally also be used Find salts use. For this purpose, the alkaline earth salts and especially the Alkali and ammonium salts in consideration ι ο

The aminophosphonic acids or their water-soluble salts can be used in various ways Plaster of paris can be added. The addition can be made in solid form. However, it is also possible to use the Add aminophosphonic acids to the water when mixing the plaster. In this way of working it is expedient to add an aqueous solution of the aminophosphonic acids or their water-soluble salts use.

The effectiveness of the individual aminophosphonic acids is different. However, in all cases a Significant increase in setting time achieved This can fluctuate within considerable limits and can exceed 7 Hours to be stretched. A particularly strong increase in the setting time is achieved with plaster of paris Use of aminotri (methylenephosphonic acid), methylaminodi- (methylenephosphonic acid) and aminomethanephosphonic acid obtain. This strong increase occurs when using methylaminodi- (methylenephosphonic acid) even if the plaster of paris still contains an addition of 10% hydrated lime. The new The way of working and the new plaster of paris therefore allow the setting time to meet the respective requirements adapt well to practice.

example 1

100 parts of plaster of paris were each with the amount of aminophosphonic acid given in Table 1 mixed and mixed with 42 parts of water when using the larger amount of aminophosphonic acid this was first dissolved in water and the solution used to mix the plaster of paris test specimens were produced in accordance with DIN 1164. The setting behavior of the plaster of paris masses produced in this way was then tested according to DIN 1168

The test method is essentially that the stiffening end is determined in minutes will. The end of stiffening is determined on various samples and is the point in time at which at 2 Impressions that are made immediately one after the other on the plaster samples, no more water on the The edge of the impression appears The pressure should be carried out with the index finger and should be around 5 kg. The individual time values obtained for the end of the stiffening are for the various additional amounts given in Table 1. As a comparison value, the stiffening end is also used for the same Plaster of paris, but without addition, given at the end of the table.

If, instead of the aminophosphonic acids listed in detail, the corresponding potassium, Sodium or ammonium salts produce comparable effects.

Tabel

Setting retarder

Plaster of paris in% by weight Added amount 0.2 0.1 > 420 420 > 420 420 > 420 420 360 180 420 104 320 127 420 135 420 240 420 105 360 155 180 85 420 250 360 160 160 55 420 204 20th 20th

Aminotri- (methylenephosphonic acid) methylaminodi- (methylenephosphonic acid) Aminomethanephosphonic acid N, N-dimethylaminomethanediphosphonic acid N, N-dibutylaminomethanediphosphonic acid Ν, Ν-dioctylaminomethanediphosphonic acid N-methylaminomethanediphosphonic acid N-butylaminomethane diphosphonic acid. N-hexylaminomethane diphosphonic acid N-Cyclohexylaminomethane diphosphonic acid. N-Benzylaminomethane diphosphonic acid l-aminoethane-l, l-diphosphonic acid, l-aminobutane-l, l-diphosphonic acid, 1-amino-l-pnenylmethanediphosphonic acid N, N-Dimethyl-l-aminoethane-l, l-diphosphonic acid without additives

Example 2

Table 2 shows the results obtained with otherwise the same procedure as in Example 1 were, but the stucco contained 10% hydrated lime.

Table 2

Setting retarder

Stucco + 10% hydrated lime amount added in% by weight 0.1 0.15

Aminotri- (methylenephosphonic acid) methylaminodi- (methy] enphosphonic acid) Aminomethanephosphonic acid Ν, Ν-dimethylaminomethanediphosphonic acid N.N-dibutylaminomethanediphosphonic acid N ^ -Dioctylaminomethanediphosphonic acid N-Methylaminomethanediphosphonic acid N-butylaminomethanediphosphonic acid N-hexylamino-methylene diphosphonic acid N-Cyclohexylarninornuhandiphosphonic acid N-Benzylaminomethanediphosphonic acid l-Am5no.ethane-l, l-diphosphonic acid l-aminobutane-l, l-diphosphonic acid 1-amino-l-phenylmethanediphosphonic acid N ^ -Dimethyl-1-aminoethane-1J-diphosphonic acid 1-Aminoethane-1-phosphonic acid comparison with diethylenediaminepentaacetic acid Without addition

168 243 420 > 420 150 325 176 420 157 420 240 420 145 420 310 420 152 420 202 420 148 420 310 420 220 420 300 420 215 262 160 330 123 22nd 22nd

Claims (1)

Patent claims: 1. Plaster of paris, in particular stucco plaster with a delayed setting, characterized by a content of aminophosphonic acids of the general formulas I and II whereby