BRPI0613009A2 - hydrophobic fillers and minerals - Google Patents

Abstract

CARGO MATERIALS AND HYDROPHAPIC MINERALS A method of preparing a hydrophobic mineral and / or filler material, for example, plaster material, comprises (i) preparing a hydrolyzate containing polysiloxanes by hydrolysis of a hydrolysable silane or a mixture of hydrolysable silanes in presence of an acid hydrolysis catalyst; and (ii) combining the polysiloxane hydrolyzate with the mineral and / or filler, and optionally water and / or a catalyst for condensation of the hydrolyzate.

Description

CARGO MATERIALS AND HYDROPHIC MINERALS

This invention relates to a process of producing minerals and filler materials, particularly plaster and plaster products that are hydrophobic and / or water resistant. Particularly, hydrophobicity and / or water resistance is provided by the addition of aqueous solutions of polysiloxanes obtained by prehydrolysis under acidic conditions of certain silanes hydrolyzates such as alkylalkoxysilanes, arylalkoxysilanes, alkenylalkoxysalkanes, alkylenalkanes, alkylene alkanes, and hydrophobicity and / or water resistance.

Gypsum products such as chipboard are made by mixing stucco with water to produce a semi-fluid mixture. The semi-fluid mixture is fed onto a cardboard sheet covered with a second cardboard sheet, and passed over a demolding platform to be molded into a coated strip. The gypsum plasterboard strip is initially soft, but then quickly hardens as calcium sulphate (stucco) hemihydrates rehydrate to calcium dehydrate dihydrate (gypsum) and then hardens, and is cut apart into separate sheets of gypsum plasterboard of plaster.

In particular, drywall is produced from basic materials including paper in the form of cardboard, stucco, water, starch and additives such as accelerators and foams. Other additives for the production of plasterboard chips are also added, including retardants such as proteins and organic acids, viscosity modifying agents; antibacterial agents; water resistant chemicals with polysiloxanes and wax emulsions; fiberglass; flame retardant enhancers such as vermiculite, clays and silica-calcinated and polymeric compounds such as polyvinyl alcohol.

As noted, pressed or plasterboard sheets are large cardboard-covered thin plasterboard panels. This invention relates to an improved process for incorporating polysiloxane into plaster, a roughing product or other mineral or filler to impart water resistance.

WO-A-81/01702 describes a process for preparing a plaster mortar containing plaster powder, water, conventional additives and a ballast material, comprising adding said materials during the production process in the preparation of the powder. gypsum, powder and water mixing or mixing water or wet mortar, alkoxy silanes and optionally a solvent and optionally a silanol polymerization catalyst and optionally substances providing acidic or basic reaction conditions in the mixing water and, optionally a fine powder consisting of reactive silica.

In one embodiment of the present invention there is provided a method for preparing a mineral and / or filler material comprising:

(i) preparing a polysiloxanes-containing hydrolyzate by hydrolysis of a hydrolysable silane or mixture of hydrolysable silanes in the presence of an acid hydrolysis catalyst; and

(ii) combining the commineral and / or filler polysiloxane hydrolyzate and optionally water and / or a catalyst for condensation of the hydrolyzate.

The process of the invention may be used to treat a wide range of minerals or powdered fillers.

The method of the invention may be used to prepare other types of water resistant and / or hydrophobic materials such as minerals and fillers. Some representative examples include fluorides, chlorides, bromides, unhydrated, partially hydrated or hydrated iodides, chromates, carbonates, hydroxides, phosphates, hydrogen phosphates, nitrates, oxides, sodium sulfates, potassium, magnesium, calcium and barium, titanium dioxide, zinc, aluminum oxide, aluminum trihydroxide, vermiculite, silica, including calcined silica, fused silica, precipitated silica, quartz, sand, silica gel, rice husk ash, ceramic and glass beads, zeolites, calcium hydrosilicate, silica composite carbon black, functionalized carbon nanotubes, cement, ash particles, slate powder, bentonite, clay, mica, kaolin, talc, calcium carbonate, volastonite, polymeric fillers, rubber particles, sawdust, wood fibers, cellulose and products containing cellulose, aramid fibers, nylon fibers, cotton fibers or glass fibers.

An example is in the preparation of plaster and hydrophobic step products, and the invention will be further described in terms of plaster, although it can be applied to other minerals and fillers. As used herein, the term "gypsum" is intended to mean all solid forms of calcium sulfate, including CaSO4-2SO20 calcium sulfate dihydrate. The term "stucco" is intended to mean calcium sulfate hemihydrate CaSO4-O7SH2O, commonly known as Paris plaster or calcined plaster, but in connection with this invention should also be understood to be dehydrated and dehydrated derivatives thereof. Stucco is produced by heating the plaster to remove 3/2 of the H2O molecule. The method for preparing hydrophobic and / or water resistant plaster and plaster products according to the invention may be used to prepare hydrophobic plaster and plaster products derived from all sources of plaster and stucco, including natural plaster (calcium sulfate dihydrate), plaster Synthesis of plasterboard sludge or synthetic plaster (desulfogypsum) slurry waste stations produced coal-fired power plants that convert sulfur dioxide into synthetic plaster and other degreasing forms such as titan, fluorogypsum and phosphogypsum. The method of the invention is particularly suitable for treating stucco in powder form as used in the preparation of plaster products such as plasterboard.

Therefore one embodiment is particularly directed to a method for producing plaster and hydrophobic and / or water resistant plaster products by:

(i) preparing a polysiloxanes-containing hydrolyzate by hydrolyzing, under acidic conditions, a hydrolysable silane or mixture of hydrolysable silanes;

(ii) combining the polysiloxane hydrolyzate with stucco and / or plaster and optionally water and / or a basic catalyst to form a semifluid mixture; and

(iii) discharging the semifluid mixture into a support or mold and drying the semifluid mixture to form a hydrophobic plaster or hydrophobic plaster product.

As used herein, the terms "polysiloxane containing hydrolyzate" and "polysiloxane hydrolyzate" are intended to include the various species resulting from the hydrolysis of alkoxy silanes, chlorosilanes, and / or acetoxysilanes, including combinations of hydroxy silanosmonomeric, organotrihydroxysilanes, branched and hydroxyl silicasinanes, cams oligomeric or polymeric and any species containing both hydroxyl and hydrolysable groups such as organodihydroxymonoalkoxysilanes and organomonohydroxydialcoxysilanes, in oligomeric or polymeric siloxane forms resulting from the partial hydrolysis or residual esterification of the hydroxy group into alkoxy groups and residual alkoxy siloxane or alkoxy functional hydroxyl groupings smaller siloxanes. Although post-distillation of alcohol byproduct significantly reduces the regeneration of alkoxy silanes, alkoxyoligosilanes, and residual alkoxypolysilanes, it is not required to achieve low water intake and consequent hydrophobic properties in plaster and plaster products.

The hydrolysable organosilane according to the present invention may comprise one or more silanes, each silanes being the same or different and comprising one or more alkoxy groups and / or one or more acetoxy groups and / or one or more halide groups (typically chloride groups) and mixtures thereof. Thus, the hydrolysable organosilane may, for example, be an alkoxy silane or acetoxy silane or an silane containing both alkoxy and acetoxy groups attached to a silicon atom. The alkoxy silane may be a monoalkoxyxysilane, dialkoxysilane, trialkoxysilane outetra-alkoxysilane. The alkoxy silane may contain the same or different alkoxy groups. Optionally, it may contain one or more halogenated substituted organic groups. The alkoxy silane may be an alkylalkoxysilane, arylalkoxysilane or alkenylalkoxysilane. Mixtures of alkoxy silanes may be used, or a mixture of alkoxy silane with acetoxysilane may be used.

A suitable organosilane group for use in the method of the invention is trialkoxysilanes having the formula RSi (OR ') 3, where "R" represents an alkyl or alkenyl group having from 1 to 18 carbon atoms and "R'" represents an alkyl group having from 1 to 4 carbon atoms. Examples of alkyl trialkoxysilanes include methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-propoxysilane, methyltri-i-propoxysilane, methyltri-n-butoxysilane, methyltri-sec-butoxysilane, methyltrisethane, methyltrisethane, n-propoxysilane, ethyltri-i-propoxysilane, ethyltri-n-butoxysilane, ethyltri-butylisilane, ethyltri-t-butoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxyltrisethoxysilane, hexiltrimetoxissilano, n-octiltrimetoxissilano, n-octyltriethoxysilane, iso-octiltrimetoxissilano, clorometiltrimetoxissilano, clorometiltrietoxissilano, cloroetiltrimetoxissilano, cloroetiltrietoxissilano, cloropropiltrimetoxissilano, chloropropyltriethoxysilane, trifluoropropiltrimetoxissilano, trifluoropropiltrietoxissilano, iltri trifluoroprop-n-propoxy ss ilano, trifluoropropiltri- i-propoxysilane, trifluoropropyltri-n-butoxysilane, trifluoropropyltris-t-butoxysilane, methyldimethoxyethoxysilane, methyldimethoxy-n-propoxysilane, methyldimethoxy-i-propoxysilane, methyldimethoxy-niethoxymethyl-methoxybutyl i-propoxysilane, methyldiethoxy-n-butoxysilane and methyldiethoxy-t-butoxysilane. Examples of alkenyltrialkoxysilanes include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriisopropoxysilane, alitrimethoxysilane, alithriethoxysilane, hexenyltrimethoxysilane and mixtures thereof. Mixtures containing at least two, entremethyltripropoxysilane and / or methyltrimethoxysilane and / or methyltriacetoxysilane and / or alkenyltrialcoxysilane and / or alkenyltriacetoxysilane have been found to be particularly efficient in the process of the invention.

Some examples of dialkyldialkoxysilanes which may be used in the method of the invention include dimethyldimethoxysilane, dimethyldiethoxysilane, ethylmethyldimethoxysilane, ethylmethyldiethoxysilane, isobutylmethyldimethoxysilane, isobutylmethyldiethoxysilane and etrifluoropropylmethyldimethoxysilane. Examples of detrialkylalkoxysilanes which may be used in the method of the invention include trimethylmethoxysilane, tri-n-propylmethoxysilane, trimethylethoxysilane, triethylethoxysilane, tri-n-propylethoxysilane and tri-n-butylethoxysilane. Examples of tetraphoxysilanes include tetramethoxysilane, tetraethoxysilane, tetra-n-propoxysilane, tetra-propoxysilane, tetra-n-butoxysilane and tetra-t-butoxysilane.

Some examples that can arilalcoxissilanos serutilizados incluemfenildimetilmetoxissilano in the method of the invention, feniletilmetilmetoxissilano, difenilmetilmetoxissilano, trifenilmetoxissilano, trifeniletoxissilano, feniletildimetoxissilano, feniletildietoxissilano, fenilmetildimetoxissilano, fenilmetildietoxissilano, fenilmetoxydietoxissilano, phenyltrimethoxysilane, phenyltriethoxysilane efenilmetiltrimetoxissilano.

Some examples of alkenyl alkoxysilanes which may be used in the method of the invention include vinyl dimethyl methoxysilane, vinyl dimethylethoxysilane, vinylmethyldethoxysilane, vinylmethyldiethoxysilane, triallylethoxysilane, diallylmethylisethoxysilane and vinylmethoxysilane.

If desired, other types of organosilanehydrolysables, such as acetoxysilanes, may be used.

Acetoxysilanes may be monoacetoxysilanes, diacetoxysilanes, triacetoxysilanes, tetraacetoxysilanes and mixtures thereof. Examples of suitable acetoxysilanes include phenylmethyldiacetoxysilane, vinylmethyldiacetoxysilane, methyltriacetoxysilane, ethyltriacetoxysilane, propyltriacetoxysilane, butyltriacetoxysilane, phenyltriacetoxysilane, vinyltriacetoxysilane and tetraacetoxysane.

Examples of silanes containing both alkoxy and acetoxy groups are methyldiacetoxymethoxysilane, methylacetoxydimethoxysilane, vinylacethoxymethoxysilane, vinylacetoxydimethoxysilane, methyldiacetoxyethoxysilane and ethylacetoxydiethoxysilane.

The acid hydrolysis catalyst in step (i) of the present invention may be any suitable acid which may be used in hydrolysis processes. Examples of suitable inorganic acids include sulfuric acid, phosphoric acid and hydrochloric acid. Examples of suitable inorganic acids include acetic acid, formic acid, oxalic acid, citric acid, trichloroacetic acid and sulfonic acids such as dodecylbenzenesulfonic acid. The preferred pH during process step (i) may be from 0.1 to 6, preferably from 3 to 5. The acid is added to the hydrolysis solution in the amount of 0.1 to 1.0 weight percent, based on the total weight of water and alkoxysilanes in hydrolysis solution. Organotrialcoxysilanes are commonly dissolved in water by vigorous stirring with acidified water until a colorless solution results. Ostrialcoxysilanes gradually hydrolyze in water to the corresponding ossilanols, which condense to empolysiloxanes. The hydrolysis of organotrialcoxysilixanes is relatively rapid while the condensation reaction is slower. Hydrolysis of silanes is typically conducted at a high dilution in water. According to the present invention, however, it has been found that improved results are achieved, particularly for hydrophobic plaster, if the hydrolyzate is prepared at a relatively high concentration of silane in water. While hydrolysis can generally be performed at a silane concentration of 0 ° C. 0.1% to 90% in water, concentrations greater than about 5% by weight may be preferred. The concentration of silane in water can be, for example, from 10% to 15% to 50%, or even higher.

After hydrolysis and condensation, the solution may, if required, be at least partially acid free, and this is achieved by neutralization with a base. A light base is generally preferred as over-neutralization may result in product instability. After neutralization, the solution is generally distilled to remove the alcohol by-product formed during hydrolysis, and the distilled solution may be filtered to remove any excess neutralizing agent and any neutralization products in the composition. Although alcohol removal is preferable, it is not a requirement. When using other hydrolysable silanes such as acetoxysilanes and chlorosilanes, hydrolysis is similar, however the by-product is an acid, ie acetic acid and hydrochloric acid, rather than an alcohol. Preferably the acid is removed or partially neutralized with a neutralizing agent. It will be appreciated that according to the present invention, in many instances the mineral and / or filler materials introduced in step (ii) may be sufficiently basic in water to effect partial neutralization without the need for any additional base material. Examples of such minerals include calcium carbonate or calcium sulfate such as stucco. When used, the catalyst used in step (ii) to catalyze the condensation of hydrolyzed silane may, for example, be a basic catalyst, an organic metal compound, such as an alkoxide. metal, or a salfluoride or a combination of any of these.

When the catalyst used in step (i) is a base, it may be any suitable strong or weak base. Examples of suitable bases include calcium oxide powder, calcium carbonate, calcium solid or liquid lime, calcium acetate, sodium hydroxide, potassium hydroxide, sodium methylate, sodium carbonate, sodium bicarbonate, sodium borate, sodium acetate , solutions of a siliconate or silicate salt such as sodium, potassium, calcium or aluminum silicates or silicates, ash particles, amines such as triethylamine, ethylenetriamine, butylamine, octylamine, monoethanolamine, diethanolamine, triethanolamine, diethylenetriamine, triethylenemethylamine, benzylate, , xylylenediamine, triethylenediamine, guanidine, diphenylguanidine, morpholine, laurylamine or N, N-dimethylbenzylamine, ammonium hydroxide, ammonium carbonate, ammonium acetate, a phosphazene base, potassium acetate, magnesium carbonate, dolomite, potassium carbonate, sodium, demagnesium oxide, cement as cement Portl and, sulphate resistant cement, blast furnace cement, pozzolanic cement, white cement, high alumina cement or expansive cement and mixtures thereof. The pH generated in an aqueous stucco and organosilane mixture with basic catalyst may be from 8 to 14. Strong bases, capable of generating a pH of at least 10, preferably about 10 to 13, are efficient catalysts in the process of the invention once that the mineral or cargo is not adversely affected by the strong base. Sodium hydroxide is an example of a strong base. It may be added in solid form, for example flakes, or as an aqueous solution. Weaker bases, generating a pH of 8 to 10 in a semifluid mixture of stucco and organosilane, are also efficient catalysts, used individually or in conjunction with an organic metal compound. The basic catalyst is added to the semi-fluid stucco mixture in an amount sufficient to achieve the desired pH, typically in an amount of 0.1% to 1.0%, based on the total weight of the semi-fluid stucco mixture. The basic catalyst acts as a condensation catalyst and improves the formation of higher molecular weight siloxane species, which improves the anchorage of the siloxanes to stucco or other mineral, giving durable hydrophobicity.

The organic metal compound which may be used as the catalyst which is combined with the polysiloxane hydrolyzate and the mineral or filler in step (ii) of the present invention may be, for example, a detitanium, tin, aluminum, zirconium or vanadium compound. It may, for example, be a metal alkoxide or a metal decarboxylate salt or a chelated metal compound. Preferred titanium compounds are titanium alkoxides, otherwise known as ester titanates, for example a tetra titanium alkoxide such as tetra-n. - titanium butoxide (tetrabutyl titanate), tetraethyl titanate, tetranonyl titanate or tetraisopropyl titanate. A titanium chelate may be used, for example, an ester detitanate chelate, such as a diisopropoxy titanium bis (acetylacetonyl) diisopropyl titanate or bis (ethylacetoacetate).

Titanium tetraalkoxides are generally more catalytically active than titanium chelate compounds. Analogous zirconium and vanadium compounds, for example, zirconate or vanadate esters may alternatively or additionally be used. Preferred aluminum compounds are aluminum alkoxides, for example aluminum sec-butanolate, or aluminum chelate compounds.

If the organic compound of a metal is a tin compound, it will generally be a tin carboxylate or an organotin carboxylate, for example dibutyltin dilaurate, dioctyltin dilaurate, stannous octoate, stannous acetate, stannous oxalate, naphthenate, bisbutylstannate, dibutyltin (isooctyl maleate) or dibutyltin bis (isooctyl thioglycollate), although a ductyl tin (2,4-pentadionate) chelate compound is also used. Combining an organic tin compound with an amine such as laurylamine may be particularly effective as a catalyst.

The amount of organic compound of a metal added as catalyst may, for example, be from 0.01% to 2% based on the total weight of the semi-fluid stock mixture, preferably from 0.02% to 0.5%.

The fluoride salt which may be used as a catalyst in step (ii) of the present invention is preferably an ammonium fluoride of the formula [R "4N] F, wherein each R" may be a monovalently optionally substituted hydrogen atom or a hydrocarbon radical , for example methyl, ethyl, n-butyl, n-propyl, isopropyl or benzyl, mixtures thereof with decarbonyl compounds such as beta-ketocarboxylic acid esters or a 1,3-diketone, a metal fluoride such as depotassium fluoride, cesium, zinc fluoride or copper fluoride, an organometallic fluoride such as dibutyltin fluoride, or an inorganic or inorganic hydrogen fluoride, phosphonium fluoride, phosphonium hydrogen fluoride, tetrafluoroborate, hexafluorosilicate or fluorophosphate. Preferred ammonium fluorides include tetrabutylammonium fluoride, tetramethylammonium fluoride, benzylmethylammonium fluoride and methylammonium fluoride and their additions to decarbonyl compounds such as acetylacetone, methyl acetoacetate, 2-ethylhexyl acetoacetate, isopropyl acetoacetate or. The amount of fluoride salt added as catalyst may, for example, be from 0.01% to 5% based on the total weight of the semi-fluid stucco mixture, preferably from 0.02% to 1%.

Combinations of two or more different hydrolyzed catalysts may be used in step (ii), for example, a basic catalyst may be used in common conjunction with metal alkoxide such as titanium, zirconium, vanadium or aluminum alkoxide, or other organic compound of a metal such as an organic tin compound and / or a salfluoride.

The hydrolysis catalyst may be introduced into a mixture of hydrolyzable organosilane and water rapidly, typically just prior to combination with stucco to form a semi-fluid mixture. It has been found that if the organosilane is hydrolyzed in the presence of the plaster or other mineral or filler, so that the organosilane hydrolysis product condenses to form polyorganosilane in the presence of the mineral or filler, opoliorganosilane initially becomes incorporated in the nomineral or filler.

The mixtures used in step (i) and / or step (ii) may further include other organosilicon compounds, silane comodiols and hydroxyl-terminal block polydimethylsiloxane fluids. Some examples include silanols, hydroxy-functional polydimethylsiloxanes and alkoxy-functional epolidymethylsiloxanes. Silanols may be silanols, silanediols or silanotriols. Some examples include trimethylsilanol, triethylsilanol, tripropylsilanol, triisopropylsilanol, tributylsilanol, triisobutylsilanol, tri (sec-butyl) silanol, tri (tert-butyl) silanol, tripentylsilanol, triisopentylsilanol, tri (sec-pentyl) silanol, tri- (tert) pentyl) silanol;

dimethylsilanediol, diethylsilanediol, dipropylsilanediol, diisopropylsilanediol, dibutylsilanediol,

diisobutylsilanediol, di (sec-butyl) silanediol, di (tert-butyl) silanediol, di-pentylsilanediol,

diisopentylsilanediol, di- (sec-pentyl) silanediol, di- (tert-pentyl) silanediol, methylsilanotriol, ethylsilanotriol, propylsilanotriol, isopropylsilanotriol, isobutylsilanotriol, sec-butylsilotriol, secanylsulanol, pentyl silanethriol, tert-pentyl silanethriol, triphenylsilanol, triphenylethylsilanol, triphenylpropylsilanol, diphenylsilanediol, diphenylsilanediol, diphenylpropylsilanediol, methylphenylsilanediol, phenylsilanotriol, and mixtures thereof.

Hydroxyl-function polydimethylsiloxanes and alkoxy-functionpolidymethylsiloxanes may contain terminal, branched or branched terminal functional groups. Suitable functional polymethylsiloxanes will generally have from 2 to 300 units repeating in the chain. This organosilicon compound is capable of acting as crosslinking agents and / or chain extenders.

If another silicon compound is used, silanol-functional polydimethylsiloxanes having from 4 to 100 repeating units in the chain are preferred. In general, the hydrolysable organosilane is hydrolyzed and then condensed to form a polysiloxane, although when a silanol-functional polysiloxane is present the hydrolysable silane groups may condense with the groupysilanol to form an extended or cross-linked polysiloxane. The weight ratio of organosilane hydrolysable to silanol or alkoxy-functional polyorganosilane is preferably at least 1:10, more preferably at least 1: 3, for example 1: 1 to 10: 1.

The concentration of silane hydrolysis product in water in the semi-fluid mixture of mineral or filler as the mineral or filler is being treated is generally about 0.1% to 50% by weight. Preferably, the amount of water is chosen such that the solution contains from 0.3% to 20% by weight, more preferably about 0.3% to 10% by weight of the hydrolyzate. When polysiloxane hydrolysate contains sufficient water, the addition of more water in process step (ii) is not required in order to form the fluid mixtures. In this case, water is an optional component in step (ii), although it may be included when additional amounts of water are required to form the fluid mixture.

OPTIONAL ADDITIVES

As noted above, other additives for the production of gypsum plasterboard are often used in commercial operations, including starch, foaming agents; wetting agents; accelerators; retardants such as proteins and organic acids; paper or fluff; viscosity modifying agents; anti-flame agents; products containing water-resistant silicon-free chemicals such as wax emulsions; glass fibers; fire-resistant improvers such as vermiculite, clays and calcined silica; and polymeric compounds such as polyvinyl alcohol. One or more additives such as these may be included in step (ii) of the present process.

EXAMPLES

The following examples are set forth to illustrate the invention in greater detail.

EXAMPLE 1

Stirring acetic acid was added to 795 milliliters of water to adjust the pH to 3.6. 5 grams of methyltrimethoxysilane (MTM) was added dropwise under constant stirring. The aqueous mixture became clear in minutes. The mixture was used fresh or kept under agitation for 2 days before being packaged and stored prior to stucco testing for a period of time.

EXAMPLE 2

Stirring acetic acid was added to 790 milliliters of water to adjust the pH to 3.6. Then 10 grams of methyltrimethoxysilane was added dropwise while stirring. The mixture was used fresh or kept under stirring for 2 days before being packaged and stored prior to stucco testing for a long time.

EXAMPLE 3

Stirring acetic acid was added to 750 milliliters of water to adjust the pH to 3.6. Then 50 grams of methyltrimethoxysilane was added dropwise while stirring. The mixture was used fresh or kept under stirring for 2 days before being packaged and stored prior to stucco testing for a long time.

EXAMPLE 4

Stirring acetic acid was added to 795 milliliters of water to adjust the pH to 3.6. Then 5 grams of methyltriethoxysilane (MTE) was then added dropwise under constant stirring. The aqueous mixture became transparent in minutes. The mixture was kept under stirring for 2 days before being packaged and stored before stuccoing for a period of time.

EXAMPLE 5

Stirring acetic acid was added to 790 milliliters of water to adjust the pH to 3.6. Then 10 grams of methyltriethoxysilane was added dropwise while stirring.

The mixture was kept under stirring for 2 days before being packed and stored prior to stucco testing for a period of time.

EXAMPLE 6

Stirring acetic acid was added to 750 milliliters of water to adjust the pH to 3.6. Then 50 grams of methyltriethoxysilane was added dropwise while stirring. The mixture was kept under stirring for 2 days before being packaged and stored prior to the stucco test for a period of time.

Example 7: GENERAL PROCEDURE

Aqueous solutions containing the polysiloxane hydrolyzate composition were prepared such that the weight of polysiloxane hydrolyzate based on the stucco weight was 0.5 to 5.0 percent. To 80 grams of the aqueous solution containing the polysiloxane hydrolyzate composition was added 100 grams of vigorously stirring plaster. No additional catalysts were used and the pH of the resulting semifluid mixture was measured at about 6 to 7. The semifluid mixture was stirred for another 60 seconds and poured into finger-shaped molds. The samples were allowed to stand at room temperature (20 ° C to 25 ° C) for 15 to 60 minutes. The disks, separated from their molds, were plaster disks three centimeters in diameter and one centimeter thick. The samples were further dried in a circulating air oven for 30 minutes at 100 ° C and then for 12 to 24 hours at 40 ° C. The discs were cooled and immersed in water for two hours. The weight of the discs before and after their immersion in water was measured. Water absorption expressed as a percentage was used as a measure of the hydrophobic property of polysiloxane hydrolyzate compositions. The water uptake of the discs treated with the polysiloxane hydrolyzate composition was compared to the adsorption of untreated plaster water having a value of about 40%. Table 1 shows the results obtained, following the procedure above.

TABLE 1 - WATER ABSORPTION

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In Table 1, MTM indicates methyltrimethoxysilane and TEM indicates methyltriethoxysilane. Examples 1 to 6 of Table 1 show that a reduction in water absorption, and consequent improvement in water resistance, were obtained with various charges of polysiloxane hydrolyzate. Table 1 also shows that good stability and improved water absorption over time can be obtained with polysiloxane hydrolysates.

EXAMPLE 8

Stirring acetic acid was added to 3962.5 milliliters of tap water to adjust the pH to 3.6. 37.5 grams of methyltrimethoxysilane (MTM) was added dropwise under constant stirring. The aqueous mixture became transparent in minutes. The mixture was kept under agitation for one day before being packaged and stored prior to the stucco test.

EXAMPLE 9

Stirring acetic acid was added to 3900 milliliters of tap water to adjust the pH to 3.6.

100 grams of methyltrimethoxysilane was then added dropwise under constant stirring. The mixture was kept under agitation for one day before being packaged and stored prior to the stucco test.

EXAMPLE 10

Stirring acetic acid was added to 3962.5 milliliters of piped water to adjust the pH to 3.6. 37.5 grams of methyltriethoxysilane (MTE) was then added dropwise under constant stirring. The aqueous mixture became clear in minutes. The mixture was kept under stirring for one day before being packaged and stored prior to stucco testing.

EXAMPLE 11

Stirring acetic acid was added to 3900 milliliters of tap water to adjust the pH to 3.6.

100 grams of methyltriethoxysilane was then added dropwise under constant stirring. The mixture was kept under agitation for one day before being packaged and stored prior to the stucco test.

EXAMPLE 12

Stirring acetic acid was added to 3962.5 milliliters of tap water to adjust the pH to 3.6.

37.5 grams of vinyltriethoxysilane (VTE) was then added dropwise under constant stirring. The mixture was kept under stirring for one day before being packaged and stored prior to the stucco test.

EXAMPLE 13

Stirring acetic acid was added to 3950 milliliters of tap water to adjust the pH to 3.6.

50 grams of vinyltriethoxysilane was then added dropwise under constant stirring. The mixture was kept under agitation for one day before being packaged and stored prior to the stucco test.

EXAMPLE 14

Stirring acetic acid was added to 3900 milliliters of tap water to adjust the pH to 3.6.

Then 100 grams of vinyltriethoxysilane was added dropwise under constant stirring. The mixture was kept under agitation for one day before being packaged and stored prior to the stucco test.

Example 15: GENERAL PROCEDURE

Aqueous solutions containing polysiloxane hydrolysate composition were prepared. The weight of polysiloxane hydrolyzate based on the weight of the plaster is 0.5 to 5.0 percent. At 80 grams of the aqueous solution containing the polysiloxane hydrolyzate composition, 100 grams of stucco was added under vigorous stirring and several drops of a 40 wt% aqueous NaOH solution to adjust the pH to 12. The semifluid mixture was stirred for another 60 seconds and poured. disc-shaped molds. Samples were allowed to stand at room temperature (20 ° C to 25 ° C) for 15 to 60 minutes. The disks, separated from their molds, were plaster disks three centimeters in diameter and one centimeter deep. The samples were further dried in a circulating air oven for 30 minutes at 100 ° C and then for 12 to 24 hours at 40 ° C. The discs were cooled and immersed in water for two hours. The weight of the discs before and after their immersion in water was measured. Water absorption expressed as a percentage was used as a measure of the hydrophobic property of polysiloxane hydrolysate composition. The water absorption of discs treated with the polysiloxane hydrolyzate composition was compared to the water absorption of untreated plaster plaster having a value of about 37% to 40%. Table 2 below sets forth the results obtained according to the above procedure.

TABLE 2 - WATER ABSORPTION

<table> table see original document page 24 </column> </row> <table> <table> table see original document page 21 </column> </row> <table>

In Table 2, MTM indicates methylethyltrimethoxysilane, MET indicates methyltriethoxysilane and VTE indicates vinyltriethoxysilane. Examples 1 to 6 and Examples 8 to 14 in Table 2 show that a dramatic reduction in water absorption and the consequent improvement in water resistance can be obtained at various charges of depolysiloxane hydrolyzate under basic catalysis compared to Table 1. Table 2 It also shows that good stability and improved water absorption over time can be achieved with polysiloxane hydrolysates.

EXAMPLE 15

Stirring citric acid was added to 85 milliliters of water to adjust the pH to 3.6. 15 grams of methyltrimethoxysilane (MTM) was added dropwise while stirring. The mixture was packaged prior to stucco testing.

Example 16

Stirring citric acid was added to 70 milliliters of water to adjust the pH to 3.6. 30 grams of methyltrimethoxysilane (MTM) was added dropwise under constant stirring. The mixture was packaged prior to stucco testing.

Example 17

Stirring citric acid was added to 50 milliliters of water to adjust the pH to 3.6. 50 grams of methyltrimethoxysilane (MTM) was added dropwise under constant stirring. The mixture was packaged prior to stucco testing.

Aqueous solutions were prepared from the hydrolysates of Examples 15 to 17 so that the weight of polysiloxane hydrolyzate based on the weight of the stucco was 1% to 2%. At 80 grams of the aqueous solution containing polysiloxane hydrolysate composition 100 grams of stucco were added under vigorous stirring.

No additional catalysts were used and the pH of the resulting semi-fluid mixture was measured between 5 and 7. The semi-fluid mixture was stirred for a further 60 seconds in disc-shaped molds and then tested as described in Example 7. Table 3 shows the results obtained, followed by if the above procedure.

TABLE 3 - WATER ABSORPTION

<table> table see original document page 27 </column> </row> <table>

Examples 15 to 17 of Table 3 show that a reduction in water absorption, and the consequent improvement in water resistance, were obtained with various charges of polysiloxane hydrolyzate from concentrated hydrolyzed solutions.

Other variations may be made on the compounds, compositions, and methods described herein without departing from the essential features of the invention. The embodiments of the invention specifically illustrated herein are exemplary only and are not intended as limitations on their scope except as defined in the appended claims.

Claims (25)

A method for preparing a mineral and / or discharge material comprising: (i) preparing a polysiloxanes-containing hydrolyzate by hydrolysing a hydrolysable silane or mixing hydrolysable silanes in the presence of an acid hydrolysis catalyst; and (ii) combining the polysiloxane hydrolyzate with at least one mineral and / or filler and optionally water and / or a catalyst for condensation of the hydrolyzate. Method according to claim 1, characterized in that the hydrolysable silane comprises one or more silanes comprising one or more alkoxy groups and / or one or more acetoxy groups and / or one or more halide groups. Method according to claim 2, characterized in that the hydrolysable silane is selected from at least one alkyl alkoxysilane, arialkoxysilane, and / or alkenylalkoxysilane or a mixture thereof. Method according to claim 2, characterized in that the hydrolysable organosilane comprises a mixture containing at least two demethyltripropoxysilane and / or methyltrimethoxysilane and / or methyltriacetoxysilane and / or alkenyltrialcoxysilane and / or alkenyltriacetoxysilane. Method according to any one of claims 2, 3 or 4, characterized in that any alcohol generated during the preparation of the polysiloxane hydrolyzate is removed before the polysiloxane hydrolyzate is contacted with the mineral material or discharge. Method according to claim 2, characterized in that the hydrolysable silane is a ketoxysilane or a mixture of acetoxysilanes, which silanes may additionally comprise one or more group chlorine per molecule. Method according to claim 2, characterized in that the hydrolysable silane is a chlorosilane or a mixture of chlorosilanes. Method according to either of Claims 6 or 7, characterized in that any excess acid generated during the preparation of the polysiloxane hydrolyzate is removed before the polysiloxane hydrolyzate is contacted with the mineral or filler material. Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7 or 8, characterized in that the pH during step (i) ranges from 0.1 to 6. Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7, 8 or 9, characterized in that the hydrolyzate is prepared at a concentration of silane in water of greater than 5% by weight. Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7, 8 or 9, characterized in that the hydrolyzate is prepared at a concentration of silane in water in the range of 15 to 90% by weight. . Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or 11, characterized in that the minerals and fillers are selected from fluorides, chlorides, bromides, unhydrated iodides, partially hydrated or hydrated, chromates, carbonates, hydroxides, phosphates, hydrogen phosphates, nitrates, oxides, sodium sulphates, potassium, magnesium, calcium and barium, titanium dioxide, zinc oxide, aluminum oxide, trihydroxide aluminum, vermiculite, silica, calcined silica, fused silica, precipitated silica, quartz, sand, silica gel, rice husk ash, ceramic and glass beads, zeolites, calcium hydrosilicate, carbon black silica composite, nanotubes carbonate, cement, ash particles, slate powder, bentonite, clay, mica, kaolin, talc, calcium carbonate, volastonite, polymeric fillers, rubber particles, sawdust, wood fibers, cellulose and products containing cellulose, aramid fibers, nylon fibers, cotton fibers or glass fibers. Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12, characterized in that the mineral and / or filler is plaster and optionally plaster. A method according to claim 13, characterized in that the plaster comprises one or more calcium sulfate dehydrate, phosphogypsum and / or desulphogypsum and / or titanogypsum and / or fluorogypsum and characterized in that the stucco is derived from natural plaster. and / or synthetic plaster. Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or -14, characterized in that the catalyst which is combined with the polysiloxane hydrolyzate and the mineral or charge is a base and the pH during step (ii) ranges from 8 to 14. A method according to claim 13 or 14 for the preparation of hydrophobic plaster and plaster products, comprising: (i) preparing a hydrolysate containing polysiloxanes by hydrolysis under hydrolysis of a hydrolysable silane or mixture of hydrolysable silanes; and (ii) combining the polysiloxane hydrolyzate, a basic catalyst and optionally water to form a semi-fluid mixture. Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14, characterized in that the catalyst which is combined with the hydrolyzate of polysiloxane and the mineral or charge is titanium, zirconium, vanadium or aluminum alkoxide. Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14, characterized in that the catalyst which is combined with the hydrolyzate of polysiloxane and the mineral oucarga is an organic tin compound. Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14, characterized in that the catalyst which is combined with the hydrolyzate of polysiloxane and the mineral oucarga is a fluoride salt. Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or -14, characterized in that the catalyst which is combined with the The polysiloxane hydrolyzate and the mineral or filler comprises a base and a titanium, zirconium, vanadium or aluminum alkoxide, an organic tin compound or a fluoride salt. Method according to any one of Claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -14, 15, 16, 17, 18, 19 or 20 characterized in that the hydrolyzable silane mixture and / or the materials with which it is combined in step (ii) also comprises a silanol, a silanediol, a silanetriol, hydroxy-functional polydimethylsiloxane, or an alkoxy-function polydimethylsiloxane. Method according to any one of claims 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, -14, 15, 16, 17, 18, 19, 20 or 21, characterized in that at least one additive comprising starch, a foaming agent, a wetting agent, an accelerator, a retarder, paper, pulp, a viscosity modifying agent, an anti-flame agent, a non-silicon containing water resistant chemical, fiberglass, a fire resistance improver, a polymeric compost and / or uncalcined plaster is additionally introduced during step (ii). A method according to any one of claims 13 or 14 for preparing hydrophobic plaster comprising mixing a hydrolyzable organosilane with a hydrolysis catalyst immediately prior to the addition of stucco and an additional catalyst, water being present as the organosilane, catalyst and stucco are mixed. . A method of preparing a hydrophobic plaster product, for example paperboard sheets, comprising preparing a hydrophobic plaster material of any one of claims 13 or 14 and discharging the hydrophobic plaster material onto a support or mold, and dry. Hydrophobic plaster product characterized in that it is prepared according to the method of claim 24.