DK158508B - HYDRAULIC PORTLAND CEMENT COMPOSITION, ITS MANUFACTURING AND PROCEDURE FOR MANUFACTURING AMINAL SALTS FOR USING ADDITIVES IN THE CEMENT COMPOSITION - Google Patents

Description

DK 158508B

The present invention relates to a hydraulic Port Landing composition, its preparation and a process for preparing amine salts for use as additives in the cement composition.

5 In the processing of e.g. Portland cement is usually used in a grinding operation either in the unworked or the semi-worked up condition to reduce the cement to a relatively small particle size. It is desirable during this grinding step to achieve as efficient operation 10 as possible, i.e. reducing the particular mineral to the desired size using as little energy as possible.

For this purpose, it is customary to add chemicals known as "grinding auxiliaries" during the grinding operation, which substances facilitate operation 15 either by increasing the rate of production or by increasing the fineness of the particles at the same rate of production, without adversely affecting the milled properties of the product.

The cleavage of the cement particles during grinding 20 exposes fresh or "status nascendi" surfaces which have high energy. The surface forces of the milled particles persist for some time after milling and can lead to packing and / or poor fluidity if not reduced. Cement whose particles are packed by vibration, e.g. during transport in a self-looser, often becomes semi-rigid and will not float unless significant mechanical strength is used to break up this packing. It is therefore desirable if the grinding additive also reduces this tendency to pack.

Many chemicals and chemical mixtures have been proposed for use as milling additives and packing inhibitors for hydraulic cement types such as Portland cement. Examples of such chemicals which have been successfully used in practice are triethanolamine salts of acetic acid 35 (U.S. Patent No. 3,329,517) and triethanolamine salts of phenol (U.S. Pat. No. 3,607,326). Likewise,

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2, the addition of amine salts of alkylbenzene sulfonic acid and the diethanol amine salt of dodecylbenzenesulfonic acid have been particularly suggested as cement additives (Japanese Patent Nos. 741408 and 741410). Furthermore, US Patent No. 2,360,517 discloses a cement grinding aid in which, as an active substance, it can be used, inter alia, substituted benzoic acid and phthalic acid.

The present invention is based on the recognition that an amine salt of a carboxylic acid containing 10 aromatic group (s), wherein the carboxylic acid is a mixture of aromatic carboxylic acids from a by-product prepared by a process for the preparation of phthalic anhydride, is excellent. fermentation additives in the grinding of hydraulic Portland cement compositions. The presence of 15 such amine salts in the ground cement also helps to inhibit the tendency of the ground cement to pack. Moreover, such salts offer the advantage that in many cases the carboxylic acid reactant is obtained in many cases from starting materials (benzene, toluene, xylenes, etc.) produced by cold distillation and thus not subject to price fluctuations and the scarcity currently characterized by chemicals which is derived solely from petroleum.

The cement composition according to the invention is thus characterized in that it contains Portland cement and intimately mixed therefrom from ca. 0.001 to approx. 1% by weight of an amine salt of a carboxylic acid containing aromatic group (s), the carboxylic acid being a mixture of aromatic carboxylic acids from a by-product prepared by a process for the preparation of phthalic anhydride.

In accordance with the invention, the mixture of acids for stepwise comprises a mixture of benzoic acid and phthalic acid, the mixture of acids being preferably prepared by hydrolysis of a by-product mixture containing benzoic acid and phthalic anhydride, in particular where the by-product is produced by distillation of an oxidation product from the production of an oxidation product from of the naphthalene. The naphthalene is obtained from

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3 coal tar.

According to the invention, amines preferably comprise triethanolamine or a mixture thereof with other amines, especially in the form of residual product from ethanolamine synthesis.

The process for preparing the cement composition is characterized in that a hydraulic cement is ground in the presence of an amine salt of a carboxylic acid (s), wherein the carboxylic acid is a mixture of aromatic carboxylic acids produced by a by-product 10. a process for the preparation of phthalic anhydride and the present process for the preparation of the amine salts used is characterized in that an amine is reacted with a mixture of aromatic carboxylic acids obtained from the by-product prepared by a process for the preparation of phthalic anhydride.

The amines used in the present invention comprise primary, secondary and tertiary aliphatic or aromatic amines and preferably alkanolamines as well as mixtures thereof. Useful amines may be represented by formulas R1 2 11 3 (A) R 1 -N-R 3 and (B) R 4 N-R 5 where R 1 is hydrogen, an alkyl, alkanol, alkaryl-2 or aryl group, R 2 is hydrogen, alkyl or alkanol R 3 is hydrogen, hydroxyl, alkyl, alkanol or 3 aryl, 4 R 4 N is pyrrolidinyl, pyrrolinyl, pyrrolyl, morpholinyl, piperidinyl or piperazinyl and R 1 is hydrogen, alkyl or alkanol.

5

As used herein, the term "aryl" should refer to a phenyl or naphthyl group. One or more of the hydrogen atoms on the aryl group may be replaced by a substituent such as nitro, halogen, preferably chloro, alkyl,

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4 preferably with 1-5 carbon atoms, especially methyl, aryl, amino or alkoxy, preferably with 1-5 carbon atoms. In addition, pyridazine, pyrimidine and pyridine, and such compounds where one or more hydrogen atoms are replaced by one or more hydroxy or alkyl groups, are also useful in the preparation of the additives herein. The terms pyrrolyl, pyrrolinyl, morpholinyl and piperazinyl as used herein also include the substituted groups known in the art, e.g. N-methylmorpholine and 4- (2-aminoethoxy) ethylmorpholine.

A particularly preferred amine component for reaction with a carboxylic acid containing an aromatic group to prepare the present additives is a residual product obtained by industrial processes for the preparation of 15 alkanolamines as disclosed in U.S. Patent No. 3,329,517. The additive is obtained from this residue obtained from the preparation of ethanolamines. The residual product can be obtained by several known methods used to synthesize ethanolamines. It can be obtained by such reactions as ammonolysis 20 or amination of ethylene oxide, reduction of nitroalcohols, reduction of amino aldehydes, ketones and esters, and reaction of halohydrin with ammonia or amines. The exact composition of the residual product varies within certain limits, and therefore the term "ethanolamines" as used herein refers to one or more mono-, di- or tri-ethanolamines, preferably between 40 and 85% by volume of triethanolamine. As a rule, the residual product is predominantly tri-ethanolamine. A specific residual product used in a particularly preferred embodiment of the invention is a commercially available mono-, di- and triethanolmine mixture having the following chemical and physical properties:

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Triethanolamine 45-55% by volume Equivalent weight 129-139

Tertiary amine 6.2-7.0 meq / g

Water 0.5% by weight, maximum 5 Density 1.14 kg / liter

Here, the carboxylic acids containing an aromatic group reacted with the amines include mono- and polycarboxylic acids having one or more aromatic groups in their molecular structure. The terms "aromatic" and "aryl", as used herein, include the unsaturated cyclic hydrocarbon groups, substantially as exemplified by phenyl, benzyl and naphthyl groups. Such carboxylic acids may have groups (e.g., alkyl, halogen, nitro, and hydroxy groups) in addition, e.g. applied to such aromatic or aryl groups when they simply do not adversely affect the intended use of the present additive compound.

Examples of carboxylic acids containing aromatic group (s) which may be used include aromatic carboxylic acids such as benzoic acid, phthalic acid and alkylbenzenecarboxylic acids, as well as aryl-substituted aliphatic acids such as naphthalene acetic acid and almond acid (a-hydroxyphenylacetic acid). -dikesyre). Mixtures of such acids may also be used. In addition, anhydrides of such acids may be used, but it may be necessary to first convert the anhydride to the acid before reacting with the amine component.

A particularly preferred carboxylic acid component for reaction with the amines to prepare the additives is that obtained from a by-product of industrial processes for the preparation of phthalic anhydride by oxidation of naphthalene, usually in the presence of catalyst, to phthalic anhydride. In the final stages of such processes, the oxidation product is subjected to a distillation step to recover the extremely pure anhydride product. A by-product produced by such distillation, sometimes referred to in the industry as "phthalic lites", comprises a

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6 mixture of benzoic acid and phthalic anhydride. Due to its impurity, this by-product has limited use. Likewise, its toxicity makes its removal complicated. It has been found that such a by-product, after treatment to convert the phthalic anhydride to the acid, is an ideal material for reacting with an amine to produce the grinding additive in question. The by-product is economically procured, and its use in hydraulic cement, where it is finally enclosed (in concrete, etc.), is a desirable way of disposing of it for environmental reasons. In addition, the by-product is obtained from naphthalene obtained from coal tar, thus avoiding many of the problems associated with petroleum-dependent chemicals.

As previously mentioned, the by-product mixture consists essentially of a mixture of benzoic acid and phthalic anhydride.

The exact proportion of each of these ingredients in the mixture can vary greatly, e.g. from 99: 1 to 1:99 benzoic acid / anhydride. It has been found desirable to convert the anhydride of the by-product to the acid before reacting with the amine 20 to prepare the grinding additive. If the product is not converted in this way, esters are produced by reaction with the amine, which leads to products which are less effective as grinding additives.

The preferred method of converting the by-product mixture is by hydrolysis, hereinafter called "hydrolyzed phthalic acid lites". In a preferred method, the by-product mixture is heated to the molten state (e.g., 110 ° C), making it easily transportable and pumpable, and added to hot water (e.g., about 80 ° C) to convert the anhydride 30 to phthalic acid . After cooling, the amine reactant is added to prepare essentially a mixture of amine salt of benzoic acid and amine salt of phthalic acid.

The amine salt additive is ground together with the cement in the milling mill, so as to obtain increased milling efficiency as well as other beneficial results, e.g. inhibition of packing of cement stored in bulk. The additives

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7 is particularly preferred for use with Portland cement, a type of hydraulic cement consisting essentially of two calcium silicates and a minor amount of calcium aluminate. These types of cement are produced by heating and intimate mixing of 5 finely divided limestones (limestone) and clayey material (clays) to form clinker. The tiles are ground with the addition of approx. 2% gypsum or other form of calcium sulfate to obtain the desired bonding properties of the final cement. It is also to the clinker that the additive is preferably added to increase the milling efficiency and inhibit the subsequent packing of the final cement.

The additives can be used either in dry or liquid form. For convenience, the additive is present in aqueous solution, allowing accurate metering to the milling stream.

The addition takes place either before grinding, or the additive is introduced into the grinding mill at the same time as the cement. If the additive is used only for the purpose of reducing packaging or to render the product free flowing, it is added at any convenient location in the processing.

The additive is used effectively within a relatively wide range, namely as mentioned from ca. 0.001 to approx. 1%, based on the weight of the cement, ie. the weight of the solids in the additive based on the weight of cement solids (hereinafter simply referred to as "solids on solids"). In a particularly preferred embodiment, the amount of additive used is from 0.004 to 0. 04%. Higher levels are used if ground to a relatively large surface area and the amount of additive is limited only by the desired surface area and where the free flowing product is desired.

As used herein, the term "packing" refers to agglomeration or adhesion of particles, e.g. by storage or transport in bulk. Adhesion results from surface forces, which for the most part are believed to occur during the milling of the cement.

The packing is determined as follows:

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8 100 g of cement are placed in a 250 ml Erlenmeyer flask placed on a variable vibrator. The flask containing the cement is vibrated for 15 seconds, then it is removed from the vibrator and fixed on a turntable with the flask beak 5 lying horizontally. The flask is then rotated around its axis until the cement packed at the bottom of the flask sinks. Turn the flask at 180 ° angles by approx.

100 turns per minute. The number of turns of 180 ° required before the sample sinks is the packing number. Thus, the greater the energy required to break up the layer, the higher the packing number will be.

The following examples serve to further illustrate the invention.

Example 1

In tests that serve to test the efficacy of chemicals as Portland cement grinding additives, several components of aromatic acid are first reacted with a triethanolamine mixture to form a salt thereof, and 20 experimental tests are performed with a laboratory scale. The triethanolamine mixture is a product obtained as a residual product from ethanolamine synthesis as previously described. Several clinkers ("A" - "D" in Table I), each from a different source of manufacture, are used for the samples.

25 In the tests, 3325 g of clinker, -0.8 mm (-20 mesh size) is ground together with 175 g of plaster (the latter is used for industrial production of "Portland cement"). The amine salts are added in various proportions (salt solids to cement solids) to the clinker / gypsum mixture before grinding.

By comparison, a blind check is also performed, i.e. a grinding of each of the clinker "A ,, - HD" with plaster and no grinding additive. Each grind is identical with respect to the individual clinker, ie. the mill operates at the same number of revolutions at 104 ° C, and the surface area ("Blaine-35 surface area") of the resulting milled product is measured in cm 2 gram. The exact number of turns varies

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9 between 5,000 and 10,000 depending on the particular clinker. The increase in fineness (the increase of "Blaine surface area") exhibited by the ground samples containing the grinding additive is calculated as a percentage of the surface area measured on the blank. This percentage is noted as "% improvement over blank" in Table I.

Duplicate,! in some cases, triple milling with each of the milling additives tested, and the indication "% improvement over blank" listed in Table I is an average value thereof. Table I gives the "hydrolyzed phthalic acid" lites "product as previously described, using method 1 of Example 2 in particular. The results are listed in Table I.

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Table I

% improvement in advance. for blank test

Trials Trials Trials Additive%% χ_2_3 Section A Triethanolamine salt of phthalic acid 0.025 6.7 8.6 7.3 7.5 A Triethanolamine salt of phthalic acid 0.014 3.5 1.8 - 2.7 10 AI trade product 0.025 9.8 7.8 9.3 9.0 AI trade product 0.013 2.2 2.3 - 2.3 A Triethanolamine salt 15 of naphthaene acetic acid 0.025 5.7 7.3 - 6.5 A Triethanolamine salt of benzoic acid 0.025 6.9 8.5 - 7.7 A Triethanolamine salt 2o of hydrolyzed phthalic acid "lites" 0.015 3.1 6.0 6.5 5.2 All commercial product 0.015 6.3 6.3 8.1 6, 9 B Triethanolamine salt 25 of hydrolyzed phthalic acid "lites" 0.015 8.9 9.3 8.9 9.0 BI commercial product 0.015 5.8 8.3 10.7 8.3 C Triethanolamine salt 30 of hydrolyzed phthalic acid "lites" 0.015 6.1 5.0 8.7 6.6 CI commercial product 0.015 7.8 5.9 7.0 6.9 D Triethanolamine salt 35 of hydrolyzed phthalic acid "lites" 0.015 8.2 8.5 7.1 7, 9

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Table I (cont.)% Improvement in advance. for Blind Test 5 Trials Trials Trials

Clinker Grinding Addi t. Added,% 1_2_3 section DI trade being product 0/015 6.4 7.7 8.6 1.6 A Triethanolamine salt of naphthalenesulfonic acid 0/025 4.9 6.4 - 5.7 Example 2

Two methods can be used to prepare the triethanolamine salt from "hydrolyzed phthalic acid" lites, the method of choice being determined primarily by the type of processing plant available. The figures in this example are based on a batch of 1000 g, but in practice batches up to 227 kg are used using both methods.

Method 1

292 g of phthalic acid "lites" are melted and the molten material is heated to between 110 and 115 ° C, then 20 g of hot water (93-100 °) is added to the molten phthalic acid "lites" with vigorous stirring. The temperature of the reaction mixture is monitored and initially observed to increase as the exothermic hydrolysis reaction 30 takes place, then becomes constant when a thermal equilibrium is reached and eventually decreases after the hydrolysis is complete. When this occurs (as evidenced by the decrease in the reaction mixture temperature), 448 g of triethanolamine are added under moderate stirring and 35 when the reaction temperature has fallen below 90 ° C, 240 g of water is added.

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Method 2 260 g of water is heated to between 75 and 100 ° C, after which 292 g of molten phthalic acid, litesH are added to the hot water with vigorous stirring. The temperature of the molten material must be between 110 and 115 ° C. The temperature is monitored. in the same manner as explained under Method 1. When the temperature of the reaction mixture drops to 70 ° C, a slow addition of 448 g of triethanolamine is started with moderate stirring, the addition of the triethanolamine being adjusted so that the reaction mixture temperature does not exceed 100 ° C.

Example 3

The ability of the grinding additive to also act as an inhibitor for the packaging of the ground product 15 is tested. Table II shows the results of samples as previously described for the additive's ability to inhibit trends in packing Portland cement clinker mixtures "A", "B" and "D". The lower the packing rate, the more effective the grinding additive is as a packing inhibitor.

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Table II

Cement Comparison Formal additive_Add% Package number 25 A None (blank) - 30 A Triethanolamine salt of naphthalene acetic acid 0.025 5 30 A Triethanolamine salt of benzoic acid 0.025 2 A Triethanolamine salt of 35 phthalic acid 0.025 3 A Trade in product 0.05 5 40

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Table II (continued)

Cement Compounds 5 Clink Formal Additive_ Added% Package Number A Triethanolamine salt of "hydrolyzed phthalic acid" lites "0.015 7 10 B None (blank) - 14 B Triethanolamine salt of" hydrolyzed phthalic acid "lites" "0.015 9 BI trade 0.015 14 20 D None (blank) - 29 D Triethanolamine salt of "hydrolyzed phthalic acid" lites "" 0.015 li 25 DI commercial product 0.015 8

Claims (7)

1. Hydraulic Portland cement composition, characterized in that it contains Portland cement and intimately mixed therefrom from ca. 0.001 to approx. 1% by weight 5 of an amine salt of a carboxylic acid containing aromatic group (s), the carboxylic acid being a mixture of aromatic carboxylic acids from a by-product prepared by a process for the preparation of phthalic anhydride. Cement composition according to claim 1, characterized in that the mixture of acids comprises a mixture of benzoic acid and phthalic acid, the mixture of acids being preferably prepared by hydrolysis of a by-product mixture containing benzoic acid and phthalic anhydride, especially where the by-product is produced by distillation of an oxidation product from the preparation of phthalic anhydride by oxidation of naphthalene. Cement composition according to claim 2, characterized in that the amine comprises triethanolamine or a mixture thereof with other amines, in particular in the form of residual product from ethanolamine synthesis. Process for preparing a hydraulic Portland cement composition according to claim 1, characterized in that a hydraulic cement is ground in the presence of an amine salt of a carboxylic acid containing aromatic group (s), the carboxylic acid being a mixture of aromatic carboxylic acids from a carboxylic acid. by-product prepared by a process for the preparation of phthalic anhydride. Process for the preparation of amine salts for use as additives in hydraulic cement according to claim 1, characterized in that an amine is reacted with a mixture of aromatic carboxylic acids obtained from the by-product prepared by a process for the preparation of phthalic anhydride. 6. A process according to claim 5, characterized in that the by-product comprises a mixture of benzoic acid and phthalic anhydride, in particular wherein the by-product mixture is hydrolyzed to convert the anhydride to phthalic acid before reaction with the amine, the amine being preferably alkaline. nolamine or a mixture of amines containing them. Process for the preparation of amine salts for use as additives in hydraulic cement according to claim 1, characterized in that a) hydrolyzes a mixture of benzoic acid and phthalic anhydride obtained as a by-product in the preparation of phthalic anhydride from naphthalene and b) reacting the hydrolyzed product of a) with a mixture of amines obtained as a residual product of ethanolamine synthesis to prepare the amine salts.