WO2011128129A1

WO2011128129A1 - Use of aqueous alkyl- and amino-functionalized silicon-containing co-condensates for the mass hydrophobization of inorganic building materials

Info

Publication number: WO2011128129A1
Application number: PCT/EP2011/052108
Authority: WO
Inventors: Manuel Friedel; Spomenko Ljesic
Original assignee: Evonik Degussa Gmbh
Priority date: 2010-04-12
Filing date: 2011-02-14
Publication date: 2011-10-20
Also published as: DE102010003870A1

Abstract

The invention relates to the use of aqueous alkyl- and amino-functionalized silicon-containing co-condensates for hydrophobing, preferably for mass-hydrophobing, inorganic building materials, in particular substantially non-siliceous building materials containing mineral alkali metals and/or alkaline earth metals, preferably gypsum.

Description

Use of aqueous alkyl- and amino-functionalized silicon-containing co-condensates for the mass-hydrophobicization of mineral building materials

The invention relates to the use of aqueous amino- and alkyl-functional silicin-containing co-condensates for hydrophobicization, preferably for the mass hydrophobization of mineral-based plastics, in particular mineral-containing and / or alkaline earth metal-containing and essentially non-aqueous. silicate building materials, preferably gypsum.

Gypsum is used under various conditions of use as a construction and material. The expert knows that gypsum is umsulfat Calci, in different

Hydration levels may be present. Due to the easy drainability

(Dehydration) of, for example, naturally occurring or obtained from industrial processes, CaSO ₄ ^» 2H ₂ O, it has a diverse range of applications.

Dehydrated gypsum anhydrite or hemihydrate obtains a more or less high strength by adding water to form a crystalline structure and can then be used as a building material. Gypsum products, such as plasterboard and

Gypsum fiberboards are often made by premixing gypsum anhydrite or hemihydrate in water and spreading the resulting gypsum slurry onto large ones

Applying belt systems to cardboard, covering them with a second layer of cardboard, bringing them into a desired shape and allowing them to set (Gypsum Data Book, Bundesverband der Gipsindustrie e.V. (ed.), 2006).

In humid rooms or outdoor applications, however, the use of gypsum as a building material is limited, since even set gypsum has a certain solubility in water and would dissolve when soaked. Water-repellent (hydrophobic) plasterboards and elements are therefore used. Particularly desirable and economical is the hydrophobing of gypsum elements in the mass (Massenhydrophobierung) already during production. It is advantageously possible to provide the aqueous gypsum slurry with an additive which gives the set material the hydrophobic properties. Advantageously, this is an aqueous system or a readily water-soluble, or

dispersible system, which together with the mixing water the

dehydrated gypsum anhydrite or hemihydrate can be added. For example, US 2007/0028809 discloses the joint use of monomers

Siliconates and a hydroxycellulose for hydrophobizing equipment of gypsum known. US 51 10684, WO 00/47536, DE 4124892 and DE 10220659 each relate to the use of hydridically H-substituted siloxanes optionally in the presence of another substituted silane for the water-repellent finishing of gypsum. The resulting in the use of such H-substituted siloxanes hydrogen requires increased demands on occupational safety and the

Safety precautions.

EP 1 1 12986 and US 2006/0107876 each disclose processes for producing water-repellent plasters in which silanes and / or siloxanes and at least one additional catalyst are added to a gypsum mixture. Thus, US 2006/0107876 discloses the use of a glycol-functionalized siloxane in the presence of alkali metal hydroxides. EP 1 12986 relates to the use of hydridically substituted siloxanes and a catalyst such as Portland cement.

GB 2433497 discloses hydrophobized gypsum mixtures obtained by adding the powdered gypsum to a hydrolyzable organosilane, water and a catalyst whereby the organosilane is hydrolyzed only in the presence of the gypsum. For this purpose it is recommended to add the catalyst to the monomeric organosilanes only immediately before the addition of the stucco. Disadvantage of the mixtures described is the VOC content of the alkoxy silanes preferably used. In addition, the reactivity of the alkoxy-silanes in such gypsum mixtures with the addition of only catalytic amounts of, for example, sodium hydroxide is low and the achievable water-repellent effect is generally not sufficiently large, as the disclosed examples show.

EP 0 819 663 B1 discloses a gypsum mixture in which a physical mixture of a lower alkyl group-substituted silane and a trialkoxysilane substituted with amino groups, amino-lower alkylamino groups or dialkylenetriamine groups are uniformly dispersed. The possible weight ratios of the two silanes are 1: 1 to 9: 1. The entire aqueous gypsum mixture is VOC-containing and still contains the entire hydrolysis of the two silanes. The disadvantage of this VOC content in the industrial production of gypsum plasterboard, as special security measures to keep the indoor air and in terms of flame retardance are to be taken. In addition, a porous gypsum is formed. EP 0796826 discloses hydrophobic gypsum mixtures which, in addition to the silane mixtures described in EP 0819663, also contain polysiloxanes. These are H-substituted polysiloxanes, with the disadvantages explained above.

Finally, WO 2007/009935 discloses a process in which the VOC content of the hydrophobing components is lowered by preparing a precondensate before the resulting siloxane is added to the gypsum mixture.

A disadvantage in turn is the necessity of adding a second catalyst to the gypsum mixture. If this second catalyst is dispensed with, the achievable water-repellent effect is not reliably given sufficiently strong.

The object of the present invention is therefore to find a composition which allows the hydrophobing of mineral building materials, in particular of gypsum, in the mass without releasing harmful volatiles in too high a concentration and / or without using an additional catalyst.

The object is achieved according to the information in the claims. In particular, the object is achieved by the invention

Use of a composition according to the features of claim 1 solved. Preferred embodiments are set forth in the subclaims and in the description. The water-soluble amino- and alkyl-functional silicon-containing co-condensate used according to the invention is referred to below as the co-condensate.

The invention relates to the use of a composition for

Massenhydrophobierung of mineral building materials, containing substantially as a water repellent at least one water-soluble amino- and alkyl-functional co-condensate and water, in particular the co-condensate amino- and / or alkyl-functional alkoxysilanes, and has crosslinking structural elements which form chain-like, cyclic and / or crosslinked structures, wherein at least one structure of the co-condensate in idealized form corresponds to the general formula I,

(R ² O) [(R ² O) i _-x (R ³⁾ _x Si (B) O] _b [Si (C) (R ⁵⁾ _y (OR ⁴⁾ i _-y O] _c [Si (D ) ₂ O] dR ⁶ * (HX) _e (I) where in the structural elements derived from alkoxysilanes

- B corresponds to an aminoalkyl radical of the general formula IIa or IIb

R ¹ VNH (2-h *) [(CH ₂ ) h (NH)] _j [(CH ₂ ) i (NH)] _n - (CH ₂ ) _k - (Ha) where h, I and k are independently whole Numbers correspond to 0 <h <6;

h * = 0, 1 or 2, j = 0, 1 or 2; 0 <I <6; n = 0, 1 or 2; 0 <k <6 and

R ¹⁰ corresponds to a benzyl, aryl, vinyl, formyl radical and / or a linear, branched and / or cyclic alkyl radical having 1 to 8 C atoms, and / or

[NH ₂ (CH ₂ ) _m ] ₂ N (CH ₂ ) p - (IIb), where m and p independently correspond to integers, with 0 <m <6 and 0 <p <6,

C is a linear, branched or cyclic alkyl radical having 1 to 20 C atoms,

- D independently corresponds to a linear, branched or cyclic alkyl radical having 1 to 8 carbon atoms, and

wherein R ² , R ⁴ and / or R ^{6 are} independently hydrogen or a linear or

are branched alkyl radical having 1 to 4 carbon atoms and

R ³ and / or R ^{5 are} independently a linear or branched alkyl radical

correspond to 1 to 4 C atoms and / or aryl radical and

- HX represents an acid, where X is an inorganic or organic

Acid residue is,

with x = 0 or 1, y = 0 or 1, b> 1, c> 0, d> 0, and e> 0 with the proviso that that (c + d)> 1. As stated, h, I and k in formula IIa may independently and also m or p in formula IIb independently correspond to a number selected from 1, 2, 3, 4, 5 or 6. In formula IIa it is preferred that k = 1 or 3 with h = 2 and / or I = 2, in particular with j = 1 and n = 1, alternatively h = 2 and j = 1 with n 0 =.

Also preferred is k = 6 with j = 0, n = 0 and h ^* = 0. In formula IIb is preferably p = 1 or 3 with m = 2. As the inorganic or organic acid radical, the expert is familiar with known conventional acid residues, for example, by adding HCl, HNO3, H ₂ SO ₄ , H ₃ PO ₄ , formic acid, acetic acid and other common acids can form.

Wherein the co-condensate, in particular of the formula I, is derived from alkoxysilanes, such as, for example, from at least one aminoalkoxysilane of the formula

B-Si (R ³ ) _x (OR ² ) _3- x and alkylalkoxysilanes of the general formulas C-Si (R ⁵ ) _y (OR ⁴ ) _3- y and / or D ₂ Si (OR ⁴ ) 2 and in the presence of Water hydrolyzed and / or condensed and the hydrolysis and optionally used organic solvents were preferably substantially completely removed, wherein the radicals C, D, R ² , R ³ and / or R ^{4 are} as defined above.

Preferred co-condensates, in particular of the formula I, include:

Amino-functional structural elements, in particular [(R ² O) i _-x (R ³⁾ _x Si (B) O] with x = 0 or 1, preferably x = 0, have, as amino-functional group, in particular B, and optionally additionally as alkyl Group preferably the following:

Aminopropyl, diaminoethylene-3-propyl, triaminodiethylene-3-propyl, derived from H ₂ N (CH ₂ ) 2 NH (CH 2) 2 NH (CH 2) 3 Si (OCH 3) 3; Aminopropyl and methyl as R ³ ; 2-aminoethyl, 2-aminoethyl and methyl as R ³ , 6-amino-n-hexyl, 6-amino-n-hexyl and methyl as R ³ ; 3-amino-n-propyl, 1-aminomethyl, 1-aminomethyl and methyl R ³ ; N-butyl-3-aminopropyl, N-butyl-3-aminopropyl and methyl as R ³ ; N-butyl-1-aminomethyl, N-butyl-1-aminomethyl, and methyl as R ³ ; N-formyl-3-aminopropyl, N-formyl-3-aminopropyl and methyl as R ³ .

Preferred co-condensates, in particular of the formula I, comprise as purely alkyl-functional structural elements, in particular independently

[Si (C) (R ⁵ ) y (OR ⁴ ) i _-y O] and / or [Si (D) ₂ O] with y = 0 or 1, preferably y = 0, which the following alkyl groups, in particular independently as C and / or D: C, is a linear or branched alkyl radical having 1 to 20 C atoms, in particular having 1 to 8 C atoms, preferably a methyl, ethyl, particularly preferably n Propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, hexyl, octyl or hexadecyl radical. D is a linear, branched or cyclic alkyl radical having 1 to 8 C atoms, preferably a methyl, ethyl, particularly preferably n-propyl, iso-propyl, n-butyl, isobutyl, pentyl, hexyl -, heptyl octyl radical and / or hexadecyl, in each case preferably methyl, n-propyl, iso-propyl, iso-butyl and / or octyl radical.

Particularly preferred co-condensates which can be used according to the invention are:

Aminopropyl and iso-butyl-functional co-condensates, which may be present partially, preferably fully hydrolyzed.

In general, the co-condensates can be linear oligomers with M and D structures, or cyclic structures of D structures or also crosslinked oligomers with M, D and T structures, as is familiar to the person skilled in the art for siloxane ( O-Si-O -) - bridge-linked co-condensates of alkoxysilanes are known which can be formed by hydrolysis and at least partial condensation of alkoxysilanes. The co-condensates used may be random, randomly distributed co-condensates and / or block co-condensates.

According to a particularly preferred embodiment, co-condensates are particularly suitable for the use according to the invention if they have a ratio of amino-functional groups B to alkyl-functional groups C and / or D in the range from 1:10 to 10: 1, preferably 1 : 5 to 5: 1, most preferably 1: 3 to 3: 1.

Co-condensates preferably used have only a low VOC content of slightly above> 200 g / l, preferably below 150 g / l, more preferably below 10 g / l. Determined according to ASTM D5095-91.

According to the invention, particularly good results for the hydrophobicization in the mass could be achieved for the following mineral building materials, as in particular particular with non-silicate building materials containing alkali and / or alkaline earth metal, in particular, the building material is an alkali and / or

Alkaline earth metal sulfate or an alkali metal and / or alkaline earth metal carbonate, independently of one another as anhydrate, as hydrate, a modification of these or mixtures thereof, preferably an alkaline earth metal sulphate, alkali metal sulphate, alkaline earth metal carbonate,

Alkali metal carbonate or a mixture containing at least one of these

Compounds, more preferably CaSO ₄ , CaSO ₄ .xH ₂ O, where x = 0, 0.5 or 2;

CaCO ₃ , MgCO ₃ , BaCO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , calcium sulfate is preferably in

various forms of hydration, especially calcium dihydrate, calcium hemihydrate, calcium sulfate anhydrite; Calcium carbonate, magnesium carbonate,

Barium carbonate, potassium carbonate, sodium carbonate in each case in the form of naturally occurring or synthetically produced minerals and anhydrous or hydrous or their modifications.

Preferably, the use of a composition comprising the cocondensate, in particular of the formula I, to 0.002 to 10 wt .-% comprising additionally at least one mineral building material and water, wherein ad 100 wt .-% is adjusted with building material and water. Further preferred is a use with a content of co-condensate in the composition of 0.01 to 5 wt .-%, preferably from 0.1 to 4 wt .-%, particularly preferably from 0.1 to 3.5 wt. -%, particularly preferably from 0.2 to 3.0 wt .-%, more preferably from 0.2 to 1, 0 wt .-%, with building material and water ad 100 wt .-%.

In addition, the co-condensate, in particular of the formula I or its hydrolysis and / or condensation products, is preferably mixed with at least one mineral building material, preferably gypsum anhydrite and / or gypsum hemihydrate, if appropriate in the presence of water. In which preferably a ratio of building material to water of 4: 1 to 1: 4 is set, in particular for gypsum, gypsum anhydrite and / or gypsum hemihydrate to water of 4: 1 to 1: 4, preferably about 1: 2.

According to a particularly preferred embodiment, (i) the at least one co-condensate, in particular of the formula I, or its hydrolysis and / or

Condensation products and optionally water with (ii) a mixture containing at least one mineral building material and water mixed, in particular an alkali and / or alkaline earth metal-containing and substantially non-silicate building material. The invention also provides the use of a mixture comprising at least one co-condensate, water and mineral building material (i) is optionally formed, and (ii) is cured. Depending on requirements, water that has formed after shaping can be decanted off or by others

Measures, such as filtration are separated. It will be understood by those skilled in the art that curing may be accomplished by an active drying process as well as at ambient conditions. This process step results in a product or article rendered hydrophobic in the mass. Preferred articles are plasterboard, cured gypsum products or gypsum elements. This can for example also be a stucco, which should be suitable for wet rooms.

The invention also provides the use in which (i) at least one cocondensate, in particular of the formula I, having a ratio of the amino group B to alkyl groups C and / or D in the range from 1:10 to 10: 1, preferably 1: 5 to 5: 1, most preferably 1: 3 to 3: 1; mixed with a mixture of (ii) gypsum anhydrite or hemihydrate and water; in particular in the ratio of 4: 1 to 1: 4, preferably from 3: 1 to 1: 3, particularly preferably from 3: 1 to 1: 1, better by 2: 1; and preferably homogenized, subsequently the prepared mixture (iv) is transferred to a mold or cured on a belt, which may be a filter belt, and (v). In step (iv), application to cardboard can also be provided.

In addition, at least one of the following components from the series of pigments, fillers, binders, crosslinkers, optical brighteners, paint assistants or other auxiliaries can be added in the inventive use.

The invention also provides an article obtainable by the use according to the invention, such as preferably a hydrophobized in the mass element of at least one mineral building material and the co-condensate. The following examples illustrate the present invention and the compositions according to the invention in more detail, without restricting the invention to these examples.

Example 1 :

Preparation of a co-condensate of isobutyltrimethoxysilane and aminopropylsilane

In a 500 ml laboratory stirred reactor with temperature sensor, dropping funnel and

Reflux are submitted under nitrogen blanketing 442 g of 3-aminopropyltriethoxysilane and 356 g of isobutyltrimethoxysilane. Within 30 minutes, 144 g of water are added dropwise. The temperature should not rise above 60 ° C, if necessary, to cool. The reaction mixture is stirred for 2 hours at 60.degree. Thereafter, the reflux condenser is replaced by a distillation bridge and 50% (about 234 g) of the resulting hydrolysis alcohol distilled off. A mixture of 500 g of water, 120.5 g of formic acid and 0.42 g of hydrochloric acid is then added dropwise within 30 minutes. The temperature should again not rise above 60 ° C, if necessary, to cool. At a pressure of 150 mbar and a sump temperature of 50 ° C will now within about 5 hours

Distilled off methanol / ethanol / water mixture and simultaneously replaced by water. In this case, water is added dropwise so that the volume of the solution remains constant.

If the head temperature is about 50 ° C and the top product only off

Water is, the distillation is stopped.

Example 2:

Preparation of a composition with water repellent, building material and

Water - production of gypsum specimens

2.1 Reference:

Unmodified, commercially available plaster (eg the company Knauf) is added to a container with water. The mass ratio of water to gypsum equals 0.5. This mixture can cure for 4 days. 2.2 According to the invention:

Unmodified, commercially available gypsum (eg the company Knauf) is mixed with water in a container. The mass ratio of water to gypsum equals 0.5. In this mixture, the mixture prepared under Example 1 is added and homogenized by stirring. Subsequently, the composition can cure for 4 days.

2.3 Testing of gypsum specimens:

The underwater storage is carried out in accordance with the specifications of DIN EN 520. The weight increase of the specimens is measured. The weight gain should be less than 5 wt .-%. The following table shows the results of the test.

Claims

claims:

1 . Use of a composition for the mass hydrophobization of

mineral building materials comprising substantially at least one water-soluble amino- and alkyl-functional co-condensate and water as hydrophobizing agent, wherein the co-condensate is derived from amino- or alkyl-functional alkoxysilanes and has crosslinking structural elements which forms chain-like, cyclic and / or crosslinked structures , wherein at least one structure of the co-condensate in an idealized form of

corresponds to general formula I,

- B corresponds to an aminoalkyl radical of the general formula IIa or IIb

R ¹ VNH (2-h *) [(CH ₂ ) h (NH)] _j [(CH ₂ ) i (NH)] _n - (CH ₂ ) _k - (Ha) where h, I and k are independently whole Correspond to numbers, with 0 <h <6;

h * = 0, 1 or 2, j = 0, 1 or 2; 0 <I <6; n = 0, 1 or 2; 0 <k <6 and

[NH ₂ (CH ₂ ) _m ] ₂ N (CH ₂ ) p - (IIb), where m and p are independently integers, with 0 <m <6 and

0 <p <6,

C is a linear, branched or cyclic alkyl radical having 1 to 20 C atoms,

- wherein R ² , R ⁴ and / or R ^{6 are} independently hydrogen or a linear or branched alkyl radical having 1 to 4 carbon atoms, and R ³ and / or R ⁵ independently correspond to a linear or branched alkyl radical having 1 to 4 C atoms and / or aryl radical and

- HX represents an acid, where X is an inorganic or organic

Acid residue is,

with x = 0 or 1, y = 0 or 1, b> 1, c> 0, d> 0, and e> 0, with the proviso that (c + d)> 1.

2. Use according to claim 1,

characterized,

the co-condensate has a ratio of amino-functional groups B to alkyl-functional groups C and / or D in the range from 1:10 to 10: 1, preferably 1: 5 to 5: 1, very particularly preferably 1: 3 to 3: 1.

3. Use according to claim 1 or 2,

characterized,

that it is used for the mass hydrophobization of mineral building materials, in particular alkali and / or alkaline earth metal-containing substantially non-silicate building materials, in particular the building material is an alkali and / or alkaline earth metal sulfate, an alkali and / or alkaline earth metal carbonate, independently of one another as anhydrate, as Hydrate, a modification of these or mixtures thereof, preferably an alkaline earth sulphate, alkali metal sulphate, alkaline earth metal carbonate, alkali metal carbonate or a mixture containing at least one of these compounds, more preferably CaSO ₄ , CaSO ₄ .xH ₂ O, x = 0, 0.5 or 2; CaCO ₃ , MgCO ₃ , BaCO ₃ , Na ₂ CO ₃ , K ₂ CO ₃ , preferably calcium sulfate in various forms of hydration, in particular calcium dihydrate, calcium hemihydrate, calcium sulfate anhydrite; Calcium carbonate, magnesium carbonate, barium carbonate, potassium carbonate, sodium carbonate in each case in the form of naturally occurring or synthetically produced minerals and anhydrous or hydrous or their modifications.

4. Use according to one of claims 1 to 3,

characterized, that the content of co-condensate in the composition comprising additionally at least one mineral building material and water is adjusted to 0.002 to 10 wt .-% and ad 100 wt .-% with building material and water.

5. Use according to one of claims 1 to 4,

characterized,

that the co-condensate or its hydrolysis and / or

Condensation products with at least one mineral building material is optionally mixed in the presence of water.

6. Use according to one of claims 1 to 5,

characterized,

that

(I) the at least one co-condensate or its hydrolysis and / or condensation products and optionally water with

(Ii) a mixture containing at least one mineral building material, in particular an alkali and / or alkaline earth metal-containing and in the

Essentially non-silicate building material, and water is mixed.

7. Use according to one of claims 1 to 6,

characterized,

the ratio of building material to water is 4: 1 to 1: 4, in particular for gypsum, gypsum anhydrite and / or gypsum hemihydrate to water of 4: 1 to 1: 4, preferably about 1: 2.

8. Use according to one of claims 1 to 7,

characterized,

that (i) is optionally formed and (ii) cured.

9. Article obtainable according to claim 8.