MXPA95002205A - Water repellent compositions - Google Patents

Abstract

Se describe una composición en emulsión acuosa adecuada para tratar superficies celulósicas o de mampostería, para volverlas repelentes al agua. Esta composición comprende (i) un alcoxisilano de fórmula RnSi(OR')4-n en donde R es un radical alquilo, un radical alquenilo, fenilo, cloropropilo o trifluoropropilo, n es 1 o 2, y R'es un radical alquilo que tiene 1 a 6átomos de carbono;(ii) un agente de acoplamiento de silano de fórmula R"mR"'pSi(OR')4-m-p'en donde R"se selecciona del grupo que consiste de grupos organofuncionales amino o amonio cuaternario, R"'es un radical alquilo que tiene 1 a 4átomos de carbono, R'tiene su significado definido previamente, m ex 1 o 2 y p es 0 o 1, con la condición de que m + p sea 2 o menor y la relación molar del alcoxisilano (i) al agente de acoplamiento de silano (ii) es 0.5:1 a 3:1;y (iii) un polímero de poliisobutileno. Emulsiones preferidas de la invención comprenden además un componente de cera.

Description

s ^ « "COMPOSITIONS REPELLENT TO WATER" Inventors: LORI ANN STARK-KASLEY, North American, domiciled at 2683 Mier Road, Midland, Michigan, E.U.A .; PAUL JOSEPH POPA, North American, domiciled at 408 Sunshine Court, Auburn, Michigan, E.U.A .; THOMAS MATTHEW GENTLE, North American, domiciled at 1953 Kimes Road, York, Pennsylvania, E.U.A .; DALE EARL HAUENSTEIN, North American, domiciled at 2111 Jenkins Drive, Midland, Michigan, E.U.A. and LINDA DENISE KENNAN, North American; domiciled at 6124 Londonberrie Court, Midland, Michigan, E.U.A.

Causaire: DOW CORNING CORPORATION, Michigan State Corporation, E.U.A. domiciled in Midland, Michigan 48686-0994, E.U.A. '•• * n FIELD OF THE INVENTION-%. "*F This invention relates to the treatment of cellulose and masonry surfaces. More particularly, it uses certain organosilicon compounds in combination with polyisobutylene, and preferably a wax, to render such surfaces water repellent.

BACKGROUND OF THE INVENTION # 10 U.S. Patent 5,073,195 discloses an aqueous solution formed by combining water, a silane coupling agent and an alkoxysilane. Then this The solution is used as a treatment agent for cellulose and masonry surfaces to return to such water repellent surfaces. An improvement over that description is claimed in the North patent ^^ W? American 5,300,327. In it, an oil wax or Synthetic is combined with the aforementioned silanes to provide improved water repellency to wood or masonry. To achieve the most desirable results, an aqueous silicone resin emulsion is also included in the compositions taught by the latest patent.

The present invention relates to compositions and methods for treating cellulose or masonry surfaces with aqueous emulsions of a combination of one or more alkoxysilanes, an amine or functional quaternary ammonium silane coupling agent and a polyisobutylene polymer. It has been found that the exclusion of water and water repellency # 10 of surfaces treated with the composition of the present invention is superior to those treated, either with the silane combination mentioned above alone or with the polymer, of polyisobutylene alone. Further, when the aqueous emulsion of the present invention also includes a wax, such as a combination of petroleum waxes and synthetic hydrocarbon waxes, the cellulosic or masonry surfaces treated therewith, exhibit water droplet formation, which is a feature valued in many consumer-oriented applications. The The latter compositions have a high degree of exclusion of initial water, and reduced swelling of the wood treated with them. These signs of water repellency were also retained after subsequent exposures to moisture. Such a combination of repellency Initial and sustained water is an unexpected result compared to the prior art.

MII-Tfl _--- i j-aa-i-i hb ^ -b-B-aa-a-r, » A composition of the present invention is in the form of an aqueous emulsion of (i) at least one alkoxysilane, (ii) at least one functional silane, amino or quaternary ammonium coupling agent; and (ii) a polyisobutylene polymer or oligomer. Component (i) of the invention is an alkoxysilane, or mixture of alkoxysilanes, of the general formula R Si (OR '). Wherein R is independently selected from the group consisting of alkyl radicals having 1 to 10 carbon atoms. carbon, preferably 1 to 6 carbon atoms, alkenyl radicals that have 2 to 8 carbon atoms, phenyl, chloropropyl and trifluoropropyl, n is 1 or 2 and R 'is an alkyl radical having 1 to 6 carbon atoms. It is preferred that both R and R "are methyl radicals, suitable alkoxysilanes are such compounds as methyltrimethoxysilane, methyltriethoxysilane, propoxysilane, ethyltrimethoxysilane, etiltributoxisilano, propyltrimethoxysilane, propyltriethoxysilane metiltri-, isobutiltri- methoxysilane, butyltriethoxysilane, hexyltrimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, dietildime- 25 toxisilano, diisobutyldimethoxysilane, silane feniltrimetoxi-, dibutildietoxisilano and dihexildimetoxisilano.

Component (ii) is a silane coupling agent 4 of formula R "mR" 'pSi (OR') 4, -mp wherein R "is selected from the group consisting of organofunctional amino or quaternary ammonium groups, R "'is an alkyl radical having 1 to 4 carbon atoms, R' has its previously defined meaning, m is 1 or 2 and p is 0 or 1, with the proviso that m + p is 2 or less. It is preferred that R1 is a methyl radical, R "is selected from N- (2-aminoethyl) -3-aminopropyl groups or AlO 3-amino-propyl and R "'is a methyl radical For component (ii), the counter ion, typically a bromide or chloride ion, is not explicitly shown for the case when R" is an organofunctional quaternary ammonium group. Suitable silane coupling agents with amino organofunctionality are N- (2-aminoethyl) -3-amino-propyltrimethoxysilane, N- (2-atinoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3 -aminopropyltri-ethoxysilane, 3-aminopropyltrimethoxysilane, N- (aminoethyl-20-aminomethyl) phenethyltrimethoxysilane, bis (2-hydroxyethyl) -3-aminopropyltrimethoxysilane, trimethoxysilylpropyl-diethylenetriamine and 3-aminopropylmethyldimethoxysilane. Suitable silane coupling agents with quaternary ammonium organofunctionality are compounds represented by the following formulas, wherein the counterion is now explicitly shown and Me, Et, and Ph hereinafter denote methyl, ethyl and phenyl radicals, -respectively: (MeO) -SiCH2CH2CH2 X2C18H3 ^ - 5 (MeO) 3SiCH2CH2CH2 2C10H21 X ~ (M.O) 3SiCH2CH2CH2 X ~ (MeO) 3SÍCH2CH2CH2 2C4H9 X ~ (M <? O) 3SiCH2CH2CH2 2CH2Ph X ~ (MeO) 3SiCH2CH2CH2 2CH2CH2OH X ~ A10 (M 0) 3 SiCH2CH2CH2 3 X ~ W (MeO) 3 SiCH2CH2CH2 3 X ~ (Et.O) 3 SiCH2CH2CH2 2C18H37 X ~ (MeO) 3 SiCH2CH2CH2 2CH2CH20-C (O) C (Me) = CH2 X "y (M.?O ) 3SiCH2CH2CH2 2 _CH2_CH2_CH2_NHC (0) (CF2 -) C6CF3_, X ~, 15 in which the counterion X is either Br or Cl. Of these, the structure (MeO) 3SiCH2CH2CH2N (Me) 2C-8H3-C1 is preferred For the present invention, the silanes (i) and (ii) are used in a molar ratio of 0.5: 1 to 3: 1, respectively, preferably in a ratio of 1: 1 to 1.5: 1. These silanes can be introduced as a cold mixture, but are preferably reacted with limited water (ie, less than stoichiometric) to form a partial hydrolyzate. This partial hydrolyzate contains an alcohol (i.e., R'OH) formed as ? hydrolysis reaction and can be used to form the emulsion of the invention, described hereinafter, without further modification. Alternatively, the alcohol can be distilled prior to the preparation of the emulsion when a composition having a low VOC content (volatile organic components) is desired. When the alkoxysilane is reacted with a silane coupling agent containing a reactive amino group or quaternary ammonium group, the reaction product can then be combined with another silane coupling agent having either a reactive organophosphorus group. amino or quaternary ammonium, if desired. Component (iii) of the invention is a polymer or oligomer of polyisobutylene having an average molecular weight number (Mn) of 200 to 2,300, preferably less than 1,500 and more preferably less * of 1,000. Such polymers and oligomers are known in The technique and many are commercially available in a variety of molecular weights and extreme group combinations. It has been found that the relatively low molecular weight of polyisobutylenes (ie, Mn less than 1,000), which have terminal groups which can be linked by hydrogen to the hydroxyl groups generally found on cellulose and masonry substrates, provide particularly superior water repellent compositions according to the present invention. Thus, the preferred polyisobutylene polymers have at least one terminal group which contains a functional group such as epoxy, halide, alkoxyphenylene, hydroxyl, carboxyl, chlorosilyl, isocyanate, amino or amido. A highly preferred end group is epoxy. Again, these specific polymers and oligomers can be prepared by methods known in the art. To form the compositions of this invention, an emulsion of components (i) to (iii) is formed by methods well known in the art. For example, an aqueous emulsion of polyisobutylene can First be prepared by mixing this component with water and a sufficient amount of a nonionic or anonic surfactant, and then by subjecting this combination to high shear, such as in a homogenizer or sonolator apparatus, to result in a stable emulsion. This The emulsion is then mixed thoroughly with the components (i) and (ii) or, preferably, the aforementioned partial hydrolyzate of (i) and (ii). For purposes of the present, from 10 to 300 parts by weight by weight of component (iii) is used for every 100 parts of the combined weights of component (i) and (ii) used. Preferably, from 30 to 150 parts of (iii) ? w? they are used for every 100 countries of (i) plus (ii). The above proportions are taken in a solid base (this e.3, active ingredients that exclude solvent and water). The aqueous emulsion thus formed and contains from 5 to 25 weight percent (solid base) of the combination of alkoxysilane (i), silane coupling agent (ii) and polyisobutylene (iii), preferably from 7.5 to 25 percent in weigh. In preferred embodiments, and where desired # 10 formation of water droplets from the treated surface, a wax (iv) is added to this emulsion. This can be done, for example, by first preparing an aqueous emulsion of the wax and adding it to the emulsion of components (i) to (iii), although the order of mixing is not critical. Component (iv) is preferably carnuba wax or a combination of petroleum and synthetic waxes, more particularly a combination which includes paraffin and polyethylene waxes. Polyethylene waxes can be high-grade polyethylene waxes or low density or mixtures of high and low density polyethylene waxes. One exemplary wax and wax that is found to be especially suitable in accordance with the present invention is JONWAX MR120, a product and trademark of S.C. Johnson & Sons Inc., Racine, Wisconsin USA. This wax is sold in the form of an aqueous emulsion of polyethylene and paraffin waxes with a solids content of about thirty-five percent. Other mixed paraffin and polyethylene waxes can also be used. When compositions of the present invention, added at a level of 5 to 1,500 parts by weight per LOO parts of the combined weights of components (i) and (ii), preferably 200 to 500 parts by weight. When the wax is included in the compositions of the present invention, The total solids content of the emulsions should be from 7.5 to 30 weight percent, preferably 7.5 to 15 weight percent. The emulsion compositions of this invention find utility as water repellent treatments for cellulosic and masonry surfaces, and can be used in a manner similar to that described in the prior art and as illustrated in the examples. Thus, they can be applied by brush application, spill, spray or spray, roller coating, immersion or scraper blade techniques. After application to a given substrate in an amount sufficient to completely coat the surface thereof and impart a water repellent character thereto, the composition of the present invention is preferably cured by exposure to ambient humidity for several days. Optimal curing quantities and conditions --¡-s-a-. are easily determined "" - by systematic experimentation by those experienced in the art The following examples are presented to further illustrate the composition and method of this invention All parts - percentages in the examples are one base in weight and all measurements are obtained at 25 C, unless otherwise indicated.The aqueous emulsion treatment compositions are prepared by mixing the components shown in the second column of table 1 at the indicated solids levels. used are as follows: MVMS / AFS is a partial hydrolyzate prepared by reacting 36 parts of methyltrimethoxysilane (MTMS) and 58 parts of N- (beta-aminoethyl) -gamma-aminopropyltrimethoxysilane (AFS) (ie molar ratio of MTMS: AFS = 1. 5: 1) with 6 parts of water, while maintaining the temperature below 50 C and distillation of the secondary product of methanol. 20 Jonwax MR120 is a product of S.C. Johnson & Sons Inc., Racine, Wisconsin USA and is described as an aqueous emulsion of polyethylene and paraffin waxes with a solids content of about thirty-five percent. 25 The abbreviation "PIB" represents several polyisobutylene products (which are also made ^^^^^^ m referecia as polybutene) sfi? moco Chemical Company, Chicago, IL. Thus, the E- * fj is described as a GDP termi¬ * Epoxy swim that has an Mn of 365. Likewise, the E-16 is described as a PIB finished in epoxy with an Mn of 975. The E-23 is described as a PIB finished in epoxy with an Mn of 1,433. L-14 is described as a vinyl-terminated GDP with an Mn of 300. In the examples, the PIB is emulsified first by running a mixture of 55% of GDP, 42% deionized water 10 and 3% of Tergitol MR TMN -6 (trimethylnonylphenyl poly (oxide * of ethylene); Union Carbide Chemical & Plastics Division, Danbury, CT) through a microfluidizer until a constant particle size is reached (at least 4 passes). 15 The hydrolyzed MTMS / AFS, Jonwax MR emulsion 120 and emulsion of PIB are mixed and diluted with water to provide the treatment emulsions shown in Table 1. It is noted, however, that the partial silane hydrolyzate alone forms a solution when it is dilutes, instead of an emulsion, the concentration of 2.5% solids used (example 1). The emulsions in Table 1 are used to treat wood samples which are then subjected to water repellency tests according to two different procedures, as described below. The water repellency, using a "Swellometer" test for wood, according to the federal (North American) specification TT-W-572B, uses platelets cut from granular, light weight, grain-average ponderosa pine sapwood. flat, dried in the oven. Wood is machined to a 38.1 mm by 254 mm (1.5 inches by 10 inches) cylinder and plates that have a thickness of 6.4 mm (1/4 of an inch) are cut from them. All wood pieces are conditioned at 50% +/- 5% relative humidity and 21.1 ° +/- 2.8 ° C until Í10 that a constant weight is reached. An untreated sample, selected from a consecutive piece of wood in each case, serves as a reference for each treated sample. The treated pieces are rinsed for three minutes in the repellent compositions based on The water is then dried with air at ambient conditions for one day, after which the samples are returned to the conditioning room for six days. When a sample after this reaches a constant weight, it is tested annually as to swelling in a "Swellometer" apparatus (basically, an apparatus for the precise determination of the change in length of the sample) according to the standard of the American Society for Testing and Materials (ASTM) 4446-84. The treated and untreated pieces are placed in appliances "Swellometer" and immerse in deionized water for thirty minutes. The swelling of each piece of wood is recorded after * a 30 minute rinse or peel-off. The percent and swelling in the longitudinal direction (% W5) is calculated as follows: 100 X (reference swelling - swelling of treated piece) / (swelling of reference). These values are reported in the fourth column of table 1. It should be evident that the value for untreated references is zero by definition, this is applicable for all similarly calculated results that relate to the tests with the "Swellometer" device. and the gravimetric tests described later. In addition, samples of the "Swellometer" apparatus are weighed before and after exposure to the water described above and the exclusion of water relative to control samples (% W) is calculated as: 100 X (reference weight - treated piece weight) / (reference weight). These values are reported in parentheses in the fourth column of table 1. The values of% WS and% WE above represent the swelling values initial and exclusion of water and are designated as "Test 1" in Table 1. In one variation, the previous tests are continued by allowing the samples to equilibrate at 50% humidity for an additional week. The 30 minute rinse is repeated and the values of% WS and % WE are determined again (Test II in table 1). This is still repeated a third time (Test III in Table 1) if the variation between Rueba I and Test II is significant (that is, * 9g £ the measurements differ by at least 10%). In a gravimetric water absorption test method, knot-free pine boards, 50.8 mm x 101.6 mm (2 x 4 inches) standard, are cut into lengths of 152.4 mm (six inches) and allowed to reach equilibrium in an atmosphere at 50% relative humidity. LDS boards = e deal with the water repellent composition either by brush treatment until they are saturated or by rinsing the boards in the composition for three minutes. The treated boards are allowed to cure for one day at ambient conditions and are allowed to float in the room at 50% moisture for six days to cure and condition the sample. An untreated reference board is stored in a room at fifteen percent relative humidity during the curing process. After curing, the boards (which include the reference board) are weighed and placed in water at room temperature for 15 minutes, they are turned over and allowed to float in the water for an additional 15 minutes. All the boards are weighed and the water absorption is calculated (Test I). The percent exclusion of water is calculated as the absorption of water from the board control minus the water absorption of the treated board, multiplied by one hundred and divided by the water absorption of the reference board. The results of this procedure are shown in the last column of table 1, where the data of repeated tests after additional conditioning for one week at 50% humidity (Test I) 'and additional conditioning for yet another week (Test III) ) are also presented.

TABLE 1 0 PERFORMANCE OF WATER REPELLENCE ON WOOD: TEST BY MEANS OF "SWELLOMETER" APPARATUS AND GRAVIMETRIC TEST EXAMPLE TREATMENT TEST SWELLOMETER TEST GRAVITY- (% in solids) (% WS) (% WE) METRIC (%) 2.5% MTMS / AFS • 4.7 (15.4) 52 ' % Jonwax M. -25.2 (36.3) 82 2.5% GDP (E-16) I 1.4 (22.2) 21.9 II 2.4 (13.8) 26.2 2. 5% GDP (E-16) 4.0 (23.9) 62.2 5% JonwaxMR II -5.3 (33.7) 60.2 25 ^^ - í-., -. ", '?. ^. z 'T ^ LA 1 (Continued) PERFORMANCE OF REPELENCE * -L WATER ON WOOD: TEST THROUGH "SWELLOMETER" APPARATUS AND GRAVIMETRIC TEST EXAMPLE TREATMENT TEST SWELLOMETER TEST GRAVITY- (% in solids) (% WS) (% WE) METRIC (%) 2. 5% MTMS / AFS I 13.6 (48.9) 87.4 5% Jonwax II 40.4 (67.6) 83.2 2. 5% MTMS / AFS I 7.1 (38.0) 66.8 2.5% GDP (E-16) II 12.1 (35.5) 52.4 III 53.2 15 2.5% MTMS / AFS 34.5 (70.9) 66.0 ** 5ca% J-ronwaxMR II 34.8 (64.7) 2.5% MTMS / AFS I 46.1 (68.4) 83.2 ** 5c,% J_onwaxMR II 45.8 (64.2) 2.5% GDP (E-16) 3. 75% MTMS / AFS I 29.0 (62.6) 82.5 25 1.25% GDP (E-23) II 40.8 (67.8) 77.7 5ce% - J-ronwaxMR III 34.8 (60.1) 77.6 TABLE 1 (Continued) PERFORMANCE OF REPELENCE _WATER ON WOOD : TEST BY MEANS OF "SWELLOMETER" APPARATUS AND GRAVIMETRIC TEST EXAMPLE TREATMENT TEST SWELLOMETER TEST GRAVITY- (% in solids) (% WS) (% WE) METRIC (%) 3.75% MTMS / AFS I 10.3 (53.4) 82.6 1.25% GDP (L-14) II 12.6 (58.6) 82.2 5ca% JTonwaxMR 11 1.25% MTMS / AFS 13.8 (59.3) 61.8 3.75% GDP (E-23) 38.6 (58.6) 50.8 5% JonwaxMR III 30.1 (62.0) 50.7 12 1.25% MTMS / AFS I 4.7 (40.0) 49.4 3.75% GDP (L-14) II 5.0 (38.3) 50.6 5 C.% 1 JTonwaxMR * Tested at 15% solids ** Different lot of tested wood It is seen from the above table that the compositions herein provide improved water exclusion or water swelling (ie, larger values of% WE,% WS of the "Swellometer" test and by - :. ? . r * -ß-1 percent exclusion, 1 # gravimetric test) than the silane mixture alone, the wax alone or the GDP alone. In addition, the initial values; 'Higher% WS and% WE are obtained for composition = pP? < § the invention containing wax (examples 7 and 8) in relation to a comparable composition (example 5) which does not contain PIB. Additionally, these values do not move much from the initial data when the tests are repeated (ie, Test II, etc.). The emulsion composition of Example 7 is used to treat sandstone and mortar samples by the federal test method (North American) SS-W-110C to compare the absorption of water in relation to untreated samples which are maintained at ambient conditions. The mortar samples are in the form of cubes, 50.8 mm (two inches) in side; The sandstone samples are pieces of sandstone Briar Hlll of 25.4 mm x 25.4 mm x # 101.6 mm (l x l - 4 inches). The pieces of mortar and sandstone are cleaned with wire brush and cleaned by blowing with high pressure air. Sandstone masters are treated by immersion in the emulsion composition for 10 seconds, followed by curing at ambient conditions.

Samples of heavy sandstone (treated and reference) are rinsed in a tray containing water to a depth of 6.4 mm (inch), weighed again and the exclusion of water (% WE) is calculated, in $ relation to the untreated reference, an average of three determinations is used: (% WE) = 100 X (reference weight - weight of treated piece) / (? that reference). When the previous curing time is two days and the rinsing time is 72 hours, the value of (% WE) as of 12.4%. In comparison, after curing for 7 days and rinsing for 72 hours, this value is 14.6%. When the above samples are dried at room atmosphere during # * 10 days and re-tested by rinsing for 96 hours, the (% WE) is 95.6%. Similarly, when these samples are dried at room atmosphere for 2 days and re-tested by rinsing for 72 hours. flush, the (% WE) is 66.5%. Mortar samples are treated in a similar manner, but require longer immersion times to obtain satisfactory water repellent character (ie, they are repeatedly immersed until 4 grams of The composition of the treatment is absorbed by the sample). After a cure of 7 days and a rinse of 72 hours, the (% WE) is 44.8%. It is noted that in relation to this date, the best method known to the applicant to carry The practice of said invention is that which is clear from the present description of the invention. Having described the invention as above, it is claimed as property, what is contained in the following

Claims (8)

CLAIMS 1. An aqueous emulsion, characterized in that it comprises: where R is alkyl radicals having 1 to 10 carbon atoms, alkenyl radicals having 2 to 8 carbon atoms, phenyl, chloropropyl and trifluoropropyl, n is 1 or 2 and R 'is an alkyl radical having 1 to 6 carbon atoms. carbon; (ii) a silane coupling agent of formula
1. R "mR" 'pSi (OR') 4.-mp wherein R "is selected from the group consisting of amino or quaternary ammonium organofunctional groups, R" 'is an alkyl radical having 1 to 4 carbon atoms, R1 has its previously defined meaning, m is 1 D 2 and p is 0 or 1, with the proviso that m + p is 2 or less and the molar ratio of the alkoxysilane (i) to the silane coupling agent (ii) is 0.5: 1 to 3: 1; and (iii) a polyisobutane polymer, wherein from 10 to 300 parts by weight of the polyisobutylene polymer (iii) are used per 100 parts by weight of component (i) plus component (ii).
2. 2. The emulsion according to claim 1, characterized in that it further comprises (iv) a wax, wherein 5 to 1,500 parts by weight of the wax (iv) are used per 100 parts by weight of the component (i) M. n »plus component (ii). 'II
3. 3. The emulsion according to claim 2, characterized in that the wax (iv) is a mixture of petroleum waxes and synthetic waxes.
4. 4. The emulsion according to claims 1-3, characterized in that n of the alkoxysilane (i) is 1, m of the cleaving agent (ii) is 1 and R 'of the 10 components (i) and (ii) is methyl.
5. 5. The emulsion according to claim 4, characterized in that R of the alkoxysilane (i) is an alkyl group having 1 to 6 carbon atoms and R "of the agent 15 coupling (ii) is selected from the group N- (2-amino-ethyl) -3-aminopropyl or 3-aminopropyl.
6. 6. The emulsion according to claims 1 # or 2, characterized in that the average molecular weight number of the polyisobutylene (iii) is less than 1,000.
7. 7. The emulsion according to claim 6, characterized in that the polyisobutylene (iii) has at least one epoxy end group and the R group of the Alkoxysilane (i) is methyl. ? »5t-
8. 8. A method for treating a surface, to make it water-repellent, the method is characterized . because it comprises applying to the surface the emulsion in accordance with claims 1 or 2. In testimony of the one which I sign the present in this City of Mexico, D.F., May 15, 1995. fifteen # twenty 25