Acid-resisting material
United States Patent Dalmatov et al.  
 1 1 ACID-RESISTING MATERIAL [76] Inventors: Vsevolod Yakolevich Dalmatov.  
  Kuskovskaya ul.. 3. k\&#39;. 20; lnna Pavlovna Kim. S. Kovalevskoi til. 10 korp. 3. kv 214. both of Moscow; Tamara Georgievna Voronkova. Polovaya ul.. 9. Skhodnya; Nikolai Alexeevich Moschansky, Bronitsk per.. 3 k\&#39;. 11. Moscow. all of USSR.  
 [22] Filed: Oct. 24., 1972 [21] Appl. No.: 300.309  
  Related U.S. Application Data [63] Continuation-impart of Ser. No. 89.436. Nov. 13.  
 1970. abandoned.  
 [52 US. Cl. 106/84, 106/2875 [51] Int. Cl. CO-lb 15/12, (04b 13/26 [58] Field of Search 106/3835. 287. 74. 16. 106/84 [56] References Cited UNITED STATES PATENTS 2.195.586 4/1940 Snell 106/74 3.008.205 11/1961 Blaies 164/16 3.179.523 4/1965 Moren. 106/3835 3.209.420 10/1965 King 164/16 FOREIGN PATENTS OR APPLICATIONS 672.061 10/1963 Canada 260/DIG. 40  
 Primary E.\&#39;(Ulllll(l-Tl&#39;lOdOIe Morris Attorney, Agent. or Firm-Holman &amp; Stern [57] ABSTRACT 0.2-5.0 percent by weight of all components. selected from the group containing furfurol. furfurol-acetone monomer. furfuryl alcohol and the mixtures thereof. The said acid-resisting material features high resistivity to acid permeation which is independent of the duration of the exposure. as well as high resistance to water.  
 8 Claims, No Drawings AClD-RESlSTlNG MATERIAL The present Application is a continuation-in-part of our copending application Ser. No. 89,436 filed Nov. 13, 1970, now abandoned.  
  The invention relates to construction materials, and more particularly, to acid-resisting materials intended for protective coyerings and coatings of floors, apparatus, reservoirs, vessels, bath-tubs and other articles, as well as for construction of acid-proof structures, articles and buildings subject to action of various acids except those containing fluorine.  
  The hitherto known acid-resisting materials, used for the above-specified purposes, had their compositions based on the aqueous solution of a water-soluble silicate of an alkali metal selected from the group consisting of sodium and potassium, a hardening initiator and inert fillers. However these known materials are not free from a series of disadvantages. They are acidpermeable, insufficiently water-resistant, of poor mechanical strength and have inadequate bonding properties to ceramics, concrete, metals; they are characterized by high deformability (shrinkage), as well as by excessive tackiness of the mixture of the initial components at&#39;the placing of this mixture, and by the short setting time thereof, which affects the productivity of labor, when the materials are used for making coatings and structures.  
  It is an object of the present invention to provide an acid-resisting material being acid-impermeable irrespectively of the time of action of acids thereupon.  
  It is another object of the present invention to provide a water-resistant acid-resisting material.  
  It is still another object of the invention to provide an acid-resisting material having increased mechanical strength.  
  It is a further object of the present invention to provide an acid-resisting material offering increased strength of bonding to concrete, ceramics, metals.  
  It is a still further object of the present invention to provide an acid-resisting material featuring reduced deformability (shrinkage), which should improve the resistance of coatings and structures to formation of cracks.  
  Furthermore, it is an object of the invention to reduce the tackiness of the mixture of the initial components of the acid-resisting material and to facilitate the placing thereof, as well as to step up the setting time of said mixture, which should enhance the productivity of labor and the quality of thejobs done with this material.  
  The herein disclosed acid-resisting material in accordance with the present invention is produced by solidifying a mixture containing sodium silicate, potassium silicate or their mixtures, an inert filler, a hardening initiator and organic additives selected from the group consisting of furfurol, furfurol-acetone monomer, furfuryl alcohol and their mixtures, taken in specific proportions.  
  The material is prepared by mixing in a specific sequence of the said components, until a truly homogeneous mixture is obtained.  
  The herein disclosed acid-resisting material (a mortar, a putty, a grade of concrete) has for its major component an aqueous solution of a water-soluble silicate of an alkali metal selected from a group containing sodium and potassium (which may also be referred to as water-soluble potash or/and sodium glass, respectively), a hardening initiator, an inert filler and an organic additive selected from the group consisting of furfuryl alcohol, furfurol and furfurol-acetone monomer and their mixtures. The aforementioned components are uniformly distributed throughout the mixture, their main characteristics being discribed hereinbelow.  
  An aqueous solution of water-soluble silicate of sodium or potassium, with the silico/alkali ratio (SiOy Na O; SiOgiKgO) being within a range, approximately, from 2.4 to 3.6, and having the specific weight substantially within a range from 1.3 gr./cu. cm to 1.45 gr./cu. cm, is taken in a quantity providing for easy placing of the mixture by the commonly practiced methods of construction work, i.e., in a quantity within a range from 9 to 30 per cent by weight of the total weight of the acid-resisting material.  
  The hardening initiator for solidifying the acidresisting material may be in the form of, e.g., sodium fluorosilicate (Na SiF potassium fluorosilicate (K SiF the grain size being, e.g., below 0.15 mm; it is taken in a quantity ensuring that the solidified acidresisting material has sufficient strength and water resistance, i.e., in a quantity from 1.0 to 5.0 per cent of the weight of the acid-resisting material; alternatively, any other suitable hardening agent may be used, taken in an appropriate quantity.  
  For the inert filler to form a mineral carcass in the herein disclosed material, there may be used quartz sand, comminuted rock with a high silica content, such as diabase, basalt, andgslte and other acid-resisting kinds of rock, as well as man-made acid-proof materials, e.g., ceramic ones, taken in a quantity of approximately 60 to per cent by weight of the total weight of the acid-resisting material.  
  When a putty is prepared, it is advisable to have the inert filler in the form of the diabase powder having the grain size not in excess of 015mm, with the content of grains below 0.075 mm in size not less than 60 per cent by weight. v  
  To prepare the herein disclosed acid-resisting material as a mortar, it is advisable to employ for the inert filler a dry mixture containing quartz sand of various degrees of fineness and diabase powder. The quartz sand should not contain clay and lime impurities and should not have the grain size in excess of 1.2 mm.  
  To prepare the herein disclosed acid-resisting material as a grade of concrete, the filler may be in the form of crushed stone obtained by crushing of acid-proof rock.  
  The organic additive in a quantity of 0.2 to 5.0 per cent by weight of the total weight of the material is selected from a group consisting of furfuryl alcohol, furfurol and furfurol-acetone monomer. The lastmentioned additive is a product of reaction between furfurol and acetone (see Synthetic Polymers and Plastics Based Thereon&#34; by A. F. Nikolaev, Moscow, Leningrad, 1964, pp. 600-603).  
  The furfurol-acetone monomer is a compound of monoand difurfurilidenacetone having the following structures:  
 monofurfurilidenac at one The abovesaid organic additives may be taken either :parately or in various combinations, either in pairs or l together.  
 When the herein disclosed acid-resisting material, -ter having hardened, is attacked by an acid, the latter, &#39;opagating to a small depth into the layer of the mateal which directly contacts the acid, brings about resinication of the abovesaid organic additive. The thus &#39;oduced resin-like products change the color of the yer to a specific tint which is different from the color t&#39;the rest of the material, and increase the density of ie layer, whereby further propagation of the acid into 1e body of the material is prevented.  
 The thickness of the above-described layer depends 1 a number of circumstances, e.g., on the kind, con- :ntration and temperature of the acid; it can be as &#34;eat as 5-6 mm.  
 The resinification of the organic additive can be ought about by other external influences, e.g., under ie action of elevated temperatures.  
 Given hereinbelow is a detailed description of one nbodiment of the invention, illustrated by a series of tamples.  
 The acid-resisting material is prepared by mixing the )mponents thereof, batched in advance in a desired &#39;oportion by weight, either in a mortar mixer or in a )ncrete mixer.  
 Initially, for 3-4 minutes, there is mixed the entire nount of inert fillers, needed for a single batch, to- :ther with the hardening initiator; then there is added ie pre-mixed aqueous solution of either sodium siliite or potassium silicate or both with the organic addive, whereafter mixing is continued for 3 to 5 minutes, &#34;itil the mixture becomes completely homogeneous. It is also possible, when preparing the herein disosed acid-resisting material, to add to the pre-mixed complete homogeneity aqueous solution of the siliite with the organic additive the mixture of the dry )mponents, containing the inert filler and the hardeng initiator.  
 The acid-resisting material prepared by the herein sclosed method features the setting time from 80 to minutes, depending on the temperature of the mixre, counted from the initial moment of the prepara- )n of the mixture.  
 To illustrate the abovesaid there is given hereinbelow series of examples, wherein the components are taken per cent by weight of the total weight of the material.  
 ample l iartz sand abase powder dium silicate (SiO :Na,O=2.8) aqueous solution to spec. weight L38 gr/cu.cm 21.0 dium fluorosilicate 2.6 rfuryl alcohol 0.8 ample 2 am sand 37.8 abuse powder 37.8  
 difurfurilidenacetone;  
 -Continued Sodium silicate (SiO- :Na O=2.8) in aqueous solution to spec. weight of EXAMPLE 4 The components are the same as in Example I, with the difference that for the organic additive, instead of the furfuryl alcohol, there is taken the mixture of substantially equal quantities of furfuryl alcohol and furfurol, also in a total quantity of 0.8 per cent by weight.  
 EXAMPLE 5 The components are the same as in Example 1, except that for the organic additive, instead of furfuryl alcohol there is taken the mixture of substantially equal quantities of furfuryl alcohol and furfurol-acetone monomer, in a total quantity of 0.8 per cent by weight.  
 EXAMPLE 6 The components are the same as in Example 1, except that for the organic additive instead of furfuryl alcohol, there is taken the mixture of substantially equal quantities of furfurol and furfurol-acetone monomer, in a total quantity of 0.8 per cent by weight.  
 EXAMPLE 7 The components are the same as in Example 1, except that for the organic additive instead of furfuryl alcohol there is taken the mixture of substantially equal quantities of furfuryl alcohol, furfurol and furfurolacetone monomer, also in a total quantity of 0.8 per cent by weight.  
 EXAMPLE 8 The components are the same as in Example 1, except that for the binder, instead of sodium silicate (SiO Na O=2.8) in aqueous solution to the spec.  
 5 weight of l.38 gr./cu.cm, there is taken the mixture of substantially equal quantities of sodium silicate (SiO Na O=2.8) and potassium silicate (SiO :K O=3.0) in aqueous solution to the spec. weight of 1.38 gr./cu.cm, also in a total quantity of 21 per cent by weight.  
 Crushed diubase 52.5 Quartz sand 20.0 Diabase powder 17.0 Sodium silicate (SiO;:Na O=2.8) in aqueous solution to the spec. weight of L38 gr./cu.cm 9.2 Sodium fluorosilicate 1.1  
 -Continued Furt&#39;uryl alcohol 0.2 Example Crushed diabase 43.5 Diabase sand 2|.S Diabase powder 21.5  
 Sodium silicate (ratio =2.S)  
 in aqueous solution to the specific weight of [.38 gr./cu.cm ll Sodium fluorosilicate l Furfuryl alcohol 0 Example ll Quartz sand 37 Diabasc powder 37 Sodium silicate (ratio =2.8)  
 in aqueous solution to the spec. weight of 1.38 gr./cu.cm 19.0 Sodium fluorosilicate 2.3 Furfuryl alcohol 2 l Furfuryl-acetone monomer l 0 Example 12 Diabase powder 60.0 Sodium silicate (ratio 2.8) in aqueous solution to the spec. weight of L38 gr./cu.cm 30.0 Sodium fluorosilicate 5.0 Furfuryl alcohol 3 0 Example 13 Diabase powder 77.0  
 coo  
  It should be understood that,a1though in the above description each one of the examples relates to a mixture containing specific kinds of the components necessary for the composition of the mixture (such as potash glass for the main binder, sodium fluorosilicate for hardening initiator, quartz sand as the inert filler, furfuryl alcohol as the organic additive), taken in specific quantitave proportion, said examples may be related to other specific kinds of necessary components for the mixture without varying substantially the quantitative proportions specified in these examples. Thus, the above-mentioned examples, which are but different modifications of the embodiments of the invention, are  
 by no means limiting the possible combinations and proportions of the components, and it should be also understood that the above specific compositions may undergo slight changes which do not change the essence of the present invention and do not depart from the spirit and scope thereof.  
 What we claim is:  
  1. An acid-resisting material obtained as a result of solidication of a mixture consisting essentially of an aqueous solution of a water-soluble silicate of sodium or potassium, an inert acid-resisting filler, a solid hard ening initiator selected from the group consisting of sodium fluorosilicate and potassium fluorosilicate, and an organic additive selected from the group consisting of furfurol, furfurol-acetone monomer, furfuryl alcohol, and mixtures thereof, said additive being present in an amount of from 0.2 to 5 percent of the total weight of said material.  
  2. A material according to claim 1 wherein said silicate is present in an amount of 9 to 30 percent by weight, said filler is present in an amount of 60 to percent by weight, said initiator is present in an amount of l to 5 percent by weight, and said additive is present in an amount of 0.2 to 5 percent by weight of the total weight of said material.  
  3. A material according to claim 2 containing 0.4 3 percent furfurol.  
  4. A material according to claim 2 containing 0.4 2 percent furfurol-acetone monomer.  
  5. A material according to claim 2 containing 0.2 5 percent furfuryl alcohol.  
  6. A method for the preparation of an acid-resisting material comprising the steps of mixing inert acidre&#39;sisting fillers with a solid hardening initiator selected from the group consisting of sodium fluorosilicate and potassium fluorosilicate, mixing a homogeneous aqueous solution of a water-soluble silicate of sodium or potassium and an organic additive selected from the group consisting of furfurol, furfurol-acetone monomer, furfuryl alcohol, and mixtures thereof, mixing said mixture of inert fillers and hardening initiator with said mixture of silicate and organic additive, and mixing the entire mixture until it becomes completely homogeneous.  
  7. A method according to claim 6 wherein said mixture of silicate and additive is added to said mixture of fillers and initiator.  
  8. A method according to claim 6 wherein said mixture of filler and initiator is added to said mixture of silicate and additive.