ES2549579B1 - Composition to remove cement-based cements and mortars - Google Patents

Abstract

Composition for removing cement-based cements and mortars. # The present invention relates to cement-based cement-removing mortars and compositions comprising a solvent component consisting of a dialkylsulfoxide or mixture of dialkylsulfoxides, such as dimethyl sulfoxide and / or sulfoxides of low molecular weight, as well as moisture absorption inhibitor components and, optionally, other auxiliary components such as ion sequestrants, hydrotropes, thickeners, preservatives, antioxidants, defoamers, pH regulators, dyes and perfumes; as well as combinations thereof. Preferably, the compositions further comprise surfactant components.

Description

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DESCRIPTION

Composition to remove cement-based cements and mortars TECHNICAL FIELD OF THE INVENTION

The present invention is part of the chemical sector, specifically in the technical field of compositions for the elimination of cement and cement-based mortars adhered to surfaces.

BACKGROUND OF THE INVENTION

Cement is a binder material resulting from the calcination of a mixture of clays, limestone and other materials that has the property of hardening in contact with water. When mixed with aggregates, water and optionally with various additives it forms a mixture of plastic consistency that sets to give a hard and resistant material called concrete or concrete and that has application in construction as a mortar, coating and supporting elements.

Among other applications, cement-based mortars are used to place various elements in horizontal and vertical ceramics, stoneware, terrazzo, tiles, stone, etc. To fill the joints between the different pieces, cement grouts or cement-based mortars are used.

After the final process of colocation and grouting, the newly constructed surface is frequently stained with the remains of cement and mortar which, when hardened, are difficult to remove. To remove these cement residues or cement-based mortar you can resort to rubbing with an abrasive material or using a chemical composition that dissolves these remains.

In the state of the art, the compositions for the removal of cement residues and cement-based mortars are constituted by acids that dissolve the cement components by chemical reaction. The compositions usually contain as strong components strong acids such as smoking hydrochloric acid, phosphoric acid and others. They are applied by spreading them on the stained surface and then

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After a period of actuation proceed to rub, remove the detached residues and rinse abundantly with water.

These compositions by their very nature have the disadvantage that they are dangerous in their application since they are corrosive to the skin and eyes, corrosive by ingestion and corrosive by inhalation. This requires the use of extreme security measures. Another drawback that limits its application is that these compositions can only be used on surfaces resistant to strong acids such as tiles and stoneware, and are not applicable on stones sensitive to acids such as marbles and limestones, or on bricks and others. also sensitive materials.

The invention protected by patent document US 6592658 proposes the use as cement stripper compositions based on citric acid, which is a non-smoking organic acid and not very aggressive for users, the environment and many resistant surfaces, but even so It can be applied on surfaces sensitive to acids such as those indicated above.

In the technical field of the invention there are no known cement removers and cement based mortars that have no acidic nature.

Low molecular weight alkylsulfoxides and especially dimethylsulfoxide (also known by the acronym DMSO) are substances that are used in the industry as solvents, as vectors to aid in the penetration of active ingredients of drugs and agricultural products mainly, and as cryopreservatives of living cells and living organs for subsequent transplants.

The most common applications in the alkylsulfoxides industry as solvents are in the technical field of paint and varnish stripper. Documents ES 2228767, ES 2263566, ES 2298702, EP 0490726, EP 0573339 and US 6673157, publish paint stripper compositions containing DMSO in their composition. Compositions containing DMSO are also used to dissolve polymers and plastics in many different applications (US 7592385, US 7592385). It is also known in the state of the art that various alkylsulfoxides, especially alkylsulfoxides, can be used as detergents (US 3243463, US 3329617, US 3898187).

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Other applications of DMSO in which it plays the role of improving the penetration of active ingredients are for example its use in herbicides, insecticides, microbicides, foliar fertilizers, dyes, etc. (US 6 133 200, US 3 756 801, US 6 133 200).

The application as a cryopreservant of living biological materials is described, for example, in US 7112576, US 5071741, US 5131850 and US 5160313.

Dimethyl sulfoxide (DMSO) and similar sulfoxides such as ethyl methyl sulfoxide (EMSO) and diethyl sulfoxide (DESO) are characterized by their ability to dissolve substances of an organic nature, such as polyacrylic polymers, polystyrene, PVC, etc., usually present in paints and varnishes. But now, the authors of the present invention have found, surprisingly and against all odds, that compositions containing at least 70% of these solvents are also capable of dissolving completely inorganic materials formed by Portland cement and mortars containing it.

It is known that DMSO, and low molecular weight sulfoxides such as EMSO and DESO, have the property of absorbing large amounts of water when exposed to the atmosphere. In the tests carried out by the authors of the present invention it was found that this was an inconvenience that severely limited the efficacy of the compositions based on these substances, since a certain threshold in the water content was exceeded, the composition abruptly ceases to remove cement , saying then that it is inactive or deactivated.

Based on these drawbacks, the composition developed by the authors of the present invention includes, in addition to dialkyl sulfoxides as solvents, moisture absorption inhibitor components, presenting a high efficiency in the elimination of cements, and mortars based of them, without damaging the surfaces on which they are.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1. Design of Central Face-centered Composition experiments (CCF) where the distribution of high values is represented

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(black), medium (gray) and low (white) of the factors tested: glycerin, Levenol C-201 and petrolatum.

Figure 2. Response surface for values of constant glycerin concentration of 7.5%. Values of liquid petrolatum between 0 and 15% and values of Levenol C-201 between 0 and 10%

DESCRIPTION OF THE INVENTION

Based on the needs posed in the state of the art, the authors of the present invention have developed a new composition for removing cement and cement-based mortars which aims to:

- Overcome the inconveniences of the state of the art detailed in the previous section regarding the impossibility of using acid-removing cement compositions on surfaces sensitive to acids such as marble and limestone, and

- Also overcome the inconvenience of water absorption and the consequent deactivation of possible neutral compositions based on DMSO and / or sulfoxides of low molecular weight such as EMSO and DESO.

Thus, in a main embodiment of the invention, a cement-based cement and mortar-removing composition comprising at least one solvent component consisting of a dialkylsulfoxide or mixture of dialkylsulfoxides, preferably dialkylsulfoxides consisting of chains of one or two carbon atoms is contemplated. , such as dimethyl sulfoxide (DMSO) and / or low molecular weight sulfoxides such as EMSO and DESO, and at least one moisture absorption inhibitor component. Preferably, glycerin is used as a moisture absorption inhibitor component. Even more preferably, liquid petrolatum is used, solubilized by the presence of surfactants such as Levenol C-201 (KAO CORPORATION) (INCI: Glycereth 17 Cocoate) (Commission Decision of 9.02.06 amending Decision 96/335 / EC, page 186).

Optionally, the composition of the invention additionally comprises at least one auxiliary component selected from ion sequestrants (eg citrates, gluconates), hydrotropes (eg ethyl alcohol, glycerin, ethylene glycol, dipropylene glycol), thickener, preservatives (eg sorbates, triclosan, parabens), antioxidants (eg BHT, BHA, acid

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ascorbic), defoamers (eg polydimethyl siloxane), pH regulators (eg, citric acid, phosphoric acid), dyes and perfumes; as well as combinations thereof.

In preferred embodiments, the composition of the invention additionally comprises at least one surfactant component. Preferably, these components are selected from non-ionic surfactants, anionic surfactants, cationic surfactants and amphoteric surfactants (eg ethoxylated fatty alcohols and ethoxylated glycerides) and combinations thereof. Preferably, in the method of the invention, Glycereth 17 Cocoate (Levenol C-201; KAO CORPORATION) or FINDET 1214 / N23 (KAO CORPORATION) (commercial mixture of Laureth-11 and Myreth-11; INCI are used as surfactants) ) (Commission Decision of 9.02.06 amending Decision 96/335 / EC).

In a particular embodiment of the invention, the composition comprises:

- 70% to 95% by weight of the solvent component,

- 5% to 30% by weight of moisture absorption inhibitors, and

- 0% to 25% by weight of auxiliary components.

In addition, preferably, the composition additionally comprises up to 15% by weight of a surfactant component.

The compositions according to the present invention are effective in removing cement and mortars that contain it, have a neutral or slightly alkaline pH, are not smokers, do not give off aggressive vapors and are not corrosive to the skin and mucous membranes. Nor do they affect the physical and chemical integrity of the cleaned surface.

In preferred embodiments of the invention the following compositions are contemplated: Composition 1:

Cement-based cement and mortar removal composition consisting of 81.9% DMSO, 7% Levenol (R) C-201, 10% liquid petrolatum, 0.3% carboxymethylcellulose (thickener auxiliary component), 0.5 % perfume, 0.3% preservative and coloring. Efficiency of elimination of cement on dry surface of value 5 on a scale of 0 to 5, that is, complete and easy removal. Water absorption equal or

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less than 0.05%, at 35 ° C, and 2 hours of exposure in an atmosphere with 65% relative humidity.

Composition 2:

Cement-based cement and mortar eliminator composition consisting of 75% DMSO, 10% Findet (R) 1214 / N23, 15% Kquida Vaseline, 0.3% preservative and dye. Efficiency of elimination of cement on dry surface of value 5 on a scale of 0 to 5. Water absorption equal to or less than 0.05%, at 35 ° C, and 2 hours of exposure in an atmosphere with 65% relative humidity.

Composition 3:

Cement-based cement and mortar removal composition consisting of 75% DMSO, 5% glycerin, 9% Levenol (R) C-201, 9% liquid petrolatum, 1.7% ascorbate sodium (ion sequestrant and antioxidant) and 0.3% preservative. Cement removal efficiency on dry surface of value 5 on a scale of 0 to 5. Water absorption equal to or less than 0.05%, at 35 ° C, and 2 hours of exposure in an atmosphere with 65% relative humidity.

Next, without being limiting, the following examples of realization of the present invention are proposed.

EXAMPLES

Example 1

Table 1 shows several previous tests of formulations whose objective is to determine which possible substances are more interesting to form the compositions according to the invention and the approximate ranges of concentration.

In order to verify the elimination efficiency, the following procedure was carried out: A glue cement mortar was prepared on a regular basis, spread using a spatula on marble, limestone and travertine and allowed to dry for at least 48 hours. The example compositions (described in Table 1) were tested by wetting the stained surfaces with the glue cement mortar, allowed to act two minutes and rubbed with a scourer. The effect of removing cement glue mortar on a scale was assessed

from 0 (no elimination) to 5 (complete and easy elimination). In general, it was found that either the elimination was zero (zero value on the scale) or quite appreciable, assigning the value of 4 when it required a greater effort to rub and 5 when it was easily removed. Intermediate values between 1 and 3 were not found. In all cases, the physical and chemical integrity of the cleaned surface was not affected.

Table 1.- Formulations tested

 Formula

 Composition Surface status Efficiency Scale: 0 to 5 Comment

 one

 DMSO 100% Dry 5 If the product is left exposed to the atmosphere it absorbs water very quickly and in less than 30 minutes it is inactivated completely losing its effectiveness. Formulation not recommended.

 2

 DMSO 100% Wet 0 Composition completely inactivated

 3

 DMSO 90% Glycerin 10% Dry 5 The elimination residue is gelatinous.

 4

 DMSO 80% Glycerin 20% Dry 4 The elimination residue is gelatinous.

 5

 DMSO 97% Water 3% Dry 5 Up to 3% water removes cement effectively

 6

 DMSO 95% Water 5% Dry 0 Deactivation is complete

 7

 DMSO 70% Glycerin 20% Water10% Dry 4 The presence of 20% glycerin allows up to 10% water to be introduced into the formulation. Interesting since it is shown that formulation 3 can absorb a certain amount of water without inactivating the composition.

 8

 DMSO 90% Glycerin 10% Wet 4 Glycerin helps in the removal of wet surfaces.

 9

 DMSO 80% Glycerin 20% Wet 4 The increase in glycerin does not improve the efficacy with respect to the formulation 8

 10

 DMSO 70% Glycerin 20% Acetone 10% Dry 5 Introducing acetone dry improves the effectiveness of formula 4.

 eleven

 DMSO 70% Glycerin 20% Acetone 10% Wet 0 It is deactivated by the presence of moisture. Although acetone dries the cement, in this case it is not interesting to introduce it.

 12

 DMSO 80% Thymol 20% Dry 0 The introduction of a very mild acid such as thymol does not improve elimination but deactivates the formula

 13

 DMSO 97% Sodium sulfate anhydrous 3% Dry 5 Elimination is faster than with 100% DMSO (Formula 1).

 Formula

 Composition Surface status Efficiency Scale: 0 to 5 Comment

 14

 DMSO 80% Methyl salicylate 20% Dry 5 As methyl salicylate produces red coloration in the presence of iron (usual component of cement), an ion sequestrant must be added to avoid this problem.

 fifteen

 DMSO 90% Findet (R) 1214 / N23 (Kao Corporation) 5% Liquid Vaseline 5% Dry 5 Effective and low water absorption due to the presence of liquid paraffin which is in turn stabilized by Findet (R) 1214 / N23 (surfactant)

 16

 DMSO 90% Levenol C-201 (Kao Corporation) 5% Liquid Vaseline 5% Dry 5 Similar to formulation 16

It was found that DMSO can be mixed, in general, with up to 30% with other components without its cement removal properties being significantly affected, except for exceptions such as thymol. Once this threshold value is exceeded, composition 5 abruptly loses its eliminating power. In the special case of water, the threshold is lower and is 3%, although the addition of hydrophilic absorbent substances such as glycerin can allow a greater presence of water in the composition. However and for obvious reasons, the preferred compositions should be free of water. The presence of liquid petrolatum, solubilized in the composition thanks to the presence of a surfactant 10 such as Findet (R) 1214 / N23 or Levenol (R) C-201, helps not absorb water and does not interfere with the cleaning efficiency . Likewise, glycerin as hydrophilic helps prevent the possible accidental presence of water from being finally absorbed by DMSO.

Example 2

To more accurately quantify the cross effects of the candidate components 15 to form compositions, a design of central compound experiments centered on the faces was made (in English literature it is called central composite face centered and is therefore usually known by the initials CCF ) (Figure 1), adjusted by multiple linear regression (MLR), whose factors are different concentrations in DMSO, of glycerin (hydrophilic water absorption regulator component), liquid petrolatum 20 (water repellent component that also acts as a water regulator absorption) and Levenol C-201 (surfactant that solubilizes liquid petrolatum).

The experiments consisted of leaving exposed for 2 hours samples with a mass of 25 grams of different compositions in an atmosphere with 65% humidity and 35 ° C

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Of temperature. The samples were weighed before the test and after the test, determining the weight gain attributable to water absorption. In parallel to this experimental design, pure components were also tested to study their water absorption as pure components. Note, therefore, that these experiments have not only been restricted to testing effective compositions against the elimination of cement, but have also studied others not effective for the purpose of the invention, but which are necessary for the mathematical analysis that leads to explain the cross effects between all components in terms of moisture absorption. Assuming ideal mixtures of the components, without cross effects, the theoretical weight increase was calculated and compared with the one actually observed. The difference between the two indicates the resulting cross effect when making the composition. The values are those shown in table 2. In some cases the mixture of the components presented a positive synergy, that is to say more water was absorbed than expected theoretically as an ideal mixture, while in other cases a negative synergy has been found, that is, less water was absorbed than expected. Of the tests it is necessary to highlight N6, N7, N8 and N14 with a negative synergy around 100%: this implies that water absorption has been zero for these experiments. In all cases, liquid petrolatum was at its maximum concentration of 15%.

The response surface obtained by MLR adjustment (multiple linear regression) for intermediate glycerin concentration values (7.5%) is shown graphically. Mathematically the response surface obtained is expressed by the following equation:

Humidity = 6.543 - 0.613G - 0.344L - 3.906V + 0.416G2 - 0.200L2 - 1.780V2 + 0.2425GL - 0.465GV - 0.848LV

where AH is the percentage of weight gain due to moisture absorption, G is the concentration in% by weight of glycerin, L is the concentration in% by weight of Levenol (R) C-201 and V is the concentration in% by petroleum jelly. The model has a coefficient of determination of 90.6% and a reproducibility of 99.4% in the central values.

Figure 2 shows that the lowest water absorption is achieved in compositions with high values of liquid petrolatum. Although these compositions are the ones that absorb less water, they are at the limit of the effectiveness of cement removal, so they should not necessarily be preferred. They are therefore interesting

compositions whose sum of percentages of glycerin, Levenol (R) C-201 (or other surfactant or mixtures of surfactants chosen from those of non-ionic, anionic, cationic or amphoteric type) and petroleum jelly Kquida (or other low volatile hydrocarbon), plus others Auxiliary components among those mentioned above do not exceed 30% to avoid the loss of efficiency 5 in the elimination of cement and cement-based mortars.

Table 2.- Design of experiments and cross effects found in the different compositions in terms of water absorption.

 Experiment

 % Glycerin% Levenol (R) C-201% Vaseline% DMSO% Observed weight increase% Expected weight increase as ideal mixture Cross effect

 N1

 0 0 0 100 8.18 8.18 0.0

 N2

 25 0 0 75 9.19 7.38 24.7

 N3

 0 10 0 90 10.60 7.49 41.5

 N4

 25 10 0 65 8.39 6.69 25.5

 N5

 0 0 15 85 5.09 6.94 -26.7

 N6

 25 0 15 60 0.05 6.13 -99.2

 N7

 0 10 15 75 -0.07 6.25 -101.1

 N8

 25 10 15 50 0.05 5.44 -99.0

 N9

 0 5 7.5 87.5 6.13 7.22 -15.1

 N10

 25 5 7.5 62.5 6.12 6.41 -4.5

 N11

 12.5 0 7.5 80 5.46 7.16 -23.8

 N12

 12.5 10 7.5 70 5.56 6.47 -14.1

 N13

 12.5 5 0 82.5 7.84 7.43 5.4

 N14

 12.5 5 15 67.5 0.02 6.19 -99.6

 N15

 12.5 5 7.5 75 7.85 6.81 15.3

 N16

 12.5 5 7.5 75 7.36 6.81 8.0

 N17

 12.5 5 7.5 75 7.75 6.81 13.8

 Glycerin

 100 0 0 0 4.95 4.95 0.0

 Levenol C-201

 0 100 0 0 1.30 1.30 0.0

 Vaseline

 0 0 100 0 -0.12 -0.12 0.0

 DMSO

 0 0 0 100 8.18 8.18 0.0

Although dimethyl sulfoxide (DMSO) was used for the assays as a representative of the family of dialkyl sulfoxides of low molecular weight and of greater industrial availability, it is understood that the compositions of the present invention can be formulated without appreciable decreases in their efficacy with dialkylsulfoxides similar such as methyl ethyl sulfoxide, diethyl sulfoxide and mixtures thereof between them and / or with DMSO.

Likewise, the introduction of quantities at the discretion of up to a total of 5% of 15 auxiliary components that help to modify the presentation properties of the compositions or improve their stability, such as ion sequestrants, hydrotropes,

thickeners, preservatives, antioxidants, defoamers, pH regulators, dyes and perfumes, did not significantly modify the cement elimination properties of the compositions.

Claims (9)

5 10 fifteen twenty 25 30 1. Composition for removing cement and cement-based mortars comprising at least one solvent component consisting of a dialkylsulfoxide or mixture of dialkylsulfoxides and at least one water absorption inhibitor component. 2. Composition according to claim 1, wherein the solvent component is selected from DMSO, EMSO, DESO and combinations thereof. 3. Composition, according to claim 1 or 2, which additionally comprises at least one auxiliary compound selected from ion sequestrants, hydrotropes, thickeners, preservatives, antioxidants, defoamers, pH regulators, dyes, perfumes and combinations thereof. 4. Composition according to any of the preceding claims, which additionally comprises at least one surfactant component selected from non-ionic surfactants, anionic surfactants, cationic surfactants, amphoteric surfactants and combinations thereof. 5. Composition according to claims 1-4, comprising: - 70% to 95% by weight of the solvent component, - 5% to 30% by weight of moisture absorption inhibitors, and - 0% to 25% by weight of the auxiliary compound. 6. Composition according to claim 5, which further comprises up to 15% by weight of the surfactant component. 7. Composition, according to the preceding claims, consisting of 81.9% DMSO, 7% Glycereth 17 Cocoate 10% liquid petrolatum, 0.3% carboxymethylcellulose, 0.5% perfume, 0.3% preservative and Colorant. 8. Composition according to claims 1-6, consisting of 75% DMSO, 10% Laureth-11 / Myreth-11, 15% liquid petrolatum, 0.3% preservative and dye. 9. Composition according to claims 1-6, consisting of 75% DMSO, a 5% glycerin, 9% Glycereth 17 Cocoate, 9% liquid petrolatum, 1.7% sodium ascorbate and 0.3% preservative