AQUEOUS COMPOSITIONS HAVING POLYALKOXYLATE SALTS FOR IMPROVED OPEN TIME

Abstract

The present invention provides aqueous compositions which have low or zero volatile organic content (VOC) comprising (i) an open time additive composition of one or more phosphorus acid salts, preferably a phosphoric acid salt, and one or more polyalkoxylates having from 2 to 15 polyalkoxylate chains and an ethylene oxide (EO) content ranging from 20 to 70 wt. %, based on the total weight of polyalkoxylate solids in the composition. The (i) additive compositions may have a solids content as high as 95 wt. %. Further, the compositions may comprise (ii) one or more aqueous polymer, such as for use in coatings or non-cementitious mortars.

Claims

1. A low volatile organic content (VOC) aqueous composition comprising (i) an additive composition of one or more phosphorus acid salts, preferably a phosphoric acid salt, and one or more polyalkoxylates having from 2 to 15 polyalkoxylate chains and an ethylene oxide (EO) content ranging from 20 to 70 wt. %, based on the total weight of polyalkoxylate solids in the composition.

2. The aqueous composition as claimed in claim 1, wherein the total amount the (i) additive composition ranges from 30 to 95 wt. %, as solids.

3. The aqueous composition as claimed in claim 1, wherein the phosphorus acid salt concentration in the (i) additive composition ranges from 0.1 to 2 millimoles/g as solids, based on the total solids of the additive composition.

4. The aqueous composition as claimed in claim 1, wherein the (i) additive composition comprises one or more polyalkoxylates of the formula I-[AO.sub.nH].sub.f, wherein I is an organic active hydrogen containing compound; wherein AO is an alkylene oxide that comprises ethylene oxide (EO) or EO combined with propylene oxide (PO) and/or butylene oxide (BO) in a random order or in an oligomer having blocks, wherein n is the total number of AO groups; and, wherein f is the total number of active hydrogen groups in I, which ranges from 2 to 15.

5. The aqueous composition as claimed in claim 4, wherein f ranges from 3 to 10.

6. The aqueous composition as claimed in claim 1, wherein in the (i) additive composition, the one or more phosphorus acid salts is a phosphate or a polyphosphate salts with a cation chosen from an alkali metals, alkaline earth metals, ammonium, and quaternary ammonium groups.

7. The aqueous composition as claimed in claim 1, wherein the (i) additive composition has one or more polyalkoxylates that is a polyalkoxylate of an active hydrogen compound chosen from polyols having 3 or more hydroxyl groups, difunctional aminoalcohols, diamines, triamines, polyamines, and phenolic resins having 3 to 8 hydroxyl groups.

8. The aqueous composition as claimed in claim 1, wherein in the (i) additive composition, at least one of the one or more polyalkoxylates has a number average molecular weight (Mn) of from 800 to 10,000.

9. The aqueous composition as claimed in any one of claims 1 to 8, which is an aqueous polymer composition that further comprises (ii) one or more aqueous polymer chosen from emulsion polymers, aqueous dispersion polymers and mixtures thereof and wherein the amount of (i) the additive composition ranges from 0.1 to 5 wt. % as solids, based on the total weight of solids in the composition.

10. A method of making a coated substrate comprising applying the aqueous polymer compositions as claimed in claim 9 and allowing it to dry to form a coated substrate.

Description

EXAMPLES

[0091] The following examples illustrate the present invention.

[0092] Abbreviations used in the Examples include: BA=butyl acrylate; MMA=methyl methacrylate; MAA=methacrylic acid; nDDM=n-dodecyl methacrylate; EHA=ethylhexyl acrylate; STY=styrene; BMA=butyl methacrylate; MPG=monopropylene glycol; DETA=diethylene triamine; DAnMDPA=3,3′ diamino-N methyl dipropylamine

[0093] Also used in the Examples are:

[0094] Acrylic emulsion polymer A (50 wt. % solids, one stage, BA/MMA emulsion polymer, Tg (DSC) <5° C.);

[0095] Acrylic acid copolymer dispersant (Tamol™ 165A, 21.50 wt. % solids, Dow);

[0096] Dioctyl sulfosuccinate surfactant (Triton™ GR-7M, Dow, 100 wt. % solids);

[0097] Mineral oil/silica defoamer (Drewplus™ L-475, Ashland Chemical, Houston, Tex., 100 wt. % solids);

[0098] Triethylene glycol bis-2-ethylhexanoate (Optifilm™ 400 coalescent, Eastman Chemicals).

[0099] Additives for open time of the invention are characterized in Table 1, below:

TABLE-US-00001 TABLE 1 Poly(alkoxylate) Additives Treated to Make Aqueous Salt Compositions Polyalkoxylate Salt Initiator, I Functionality, f % EO Mn 1 Sorbitol 6 35.7 6000 2 Di-ethylene Triamine 5 25 5000 3 Glycerine 3 32 4500 4 Diol (MPG) 2 40 2500

[0100] The polyalkoxylates listed in Table 1, above, were treated with dry P.sub.2O.sub.5 and ammonium hydroxide to neutralize the mixture of polyalkoxylate and P.sub.2O.sub.5 and create a mixture of polyalkoxylate in a salt solution.

[0101] In Example 1, 102 g of the Example 1 polyalkoxylate was treated with 7.5 gm of P.sub.2O.sub.5 (3.1 moles P.sub.2O.sub.5 to 1 molar equivalent of the polyalkoxylate) at room temperature and neutralized with ammonium hydroxide to give a product with 72 wt. % solids as an ammonium salt. The resultant additive compositions are shown in Table 2, below.

[0102] In Example 2, 113 g of the Example 2 polyalkoxylate was treated with 3.9 gm of P.sub.2O.sub.5 (1.8 molar equivalents of the P.sub.2O.sub.5 to 1 equivalent of the polyalkoxylate) at room temperature and neutralized with ammonium hydroxide to give a product with 75 wt. % solids as an ammonium salt. The resultant additive compositions are shown in Table 2, below.

[0103] In Example 3, 100 g of the Example 3 polyalkoxylate was treated with 5.75 gm of H.sub.3PO.sub.4 (1 molar equivalent H.sub.3PO.sub.4 to 1 molar equivalent of polyalkoxylate) at room temperature and was neutralized with ammonium hydroxide to give a product with 68 wt. % solids of ammonium salt. The resultant additive compositions are shown in Table 2.

[0104] In Example 4, 100 g of the Example 4 polyalkoxylate was treated with 6.9 gm of H.sub.3PO.sub.4 (0.67 equivalents to 1 equivalent of polyalkoxylate) at room temperature and neutralized with ammonium hydroxide to give a product with 68 wt. % solids of ammonium salt. The resultant additive compositions are shown in Table 2.

TABLE-US-00002 TABLE 2 Polyalkoxylate Salt Compositions Polyalkoxylate mmol/gm of Salt Wt. % Solids Ammonium salt 1S 72 0.64 2S 75 0.34 3S 68 2.3 4S 68 1.4

[0105] The additives in Examples 1S and 2S of Table 2, above, were added at 2 wt. %, as solids, of the total formulation to the aqueous coating composition shown in Table 3, below. The additives in Examples 3S and 4S of Table 2, above, were added at 1 wt. % of the total formulation to the aqueous coating compositions shown in Table 3, below. The additives were included in the letdown to make an aqueous paint composition.

TABLE-US-00003 TABLE 3 Aqueous Coating Composition with an Acrylic Emulsion Polymer at a 22% PVC and volume solids of 36 wt. % Wt. Material Name parts Grind Rutile TiO.sub.2 slurry (76.5 wt. % solids in water, Ti-Pure ™ 1584.45 R-746, Chemours, Wilmington, DE) Polyacrylic acid dispersant (25 wt. % in water, Tamol ™ 731A, 33.97 Dow) Polyether siloxane surfactant (BYK 348, Byk Additives, Inc., 4.53 Louisville, KY) Polyether siloxane defoamer (Tego Foamex ™ 810, Evonik 2.26 Industries, Parsippany, NJ) Grind Sub-total 1625.22 Premix Water 94.67 Acrylic emulsion polymer A 2374.41 Ammonia (28%) 3.17 BYK 348 surfactant 4.53 Tego Foamex ™ 810 defoamer 2.26 Acrysol ™ RM-2020 NPR Hydrophobically modified 138.15 ethoxylated urethane (HEUR) rheology modifier (Dow) Acrysol ™ RM-8W (HEUR rheology modifier, Dow) 19.48 Water 549.44 Premix Sub-total 3186.11 Totals 4811.33 Property Value Total % PVC 21.95 Volume Solids 36.44

[0106] The formulations were tested, as follows:

[0107] Open time: The indicated composition in a container was drawn down on a Leneta chart (B#4425 paper, Leneta company, Inc., Mahwah, N.J.), with a 125 micron (5 mil) square bar that is 10 cm (4″) wide. Immediately after the drawdown was complete, a timer was started at 0 minutes. With a tongue depressor, two (2) parallel lines were drawn from the edge of the chart and running ⅓ of the length of the chart. A brush (2.54 cm nylon brush, Wooster model 4176, Wooster Brush Company, Wooster, Ohio) was dipped in the composition and brushed out on scrap paper. The container with the indicated composition was placed on a scale. Then, starting with the 1 minute time mark and repeating every min. thereafter, the brush was loaded so that from 1 to 2 cm (½ in.-¾ in.) of the bristles of the brush were dipped into the composition in the container so as to hold the desired amount of 0.6-0.7 gms of the composition on the brush, as determined by weighing the container with a scale. The loaded brush was placed down on the left side of the drawdown and brushed in a back and forth manner across the two scribed lines of the painted Leneta chart. Each stroke was counted as 1 (back and forth=2). In each minute, this was repeated until 20 strokes were completed; the brushing time was 30 seconds within each minute. This was continued every minute until “failure” was observed visually. Failure means the scribed lines did not disappear after brushing. The time for such failure was recorded as the open time of the composition. An average from a total of three trials of this experiment was taken for each Example indicated and the results were recorded as the open time of the composition in Table 4, below.

TABLE-US-00004 TABLE 4 Open Time Additive Performance Example @ 2 wt. % Open time, mins 1* 8.3 2* 12.5 1S 15.3 2S 17.3 3S 12.3 4S 6.3 None* 4 *Denotes Comparative Example

[0108] As shown in Table 4, above, aqueous coating compositions with the open time (i) additive composition of the present invention dramatically improved the open time of the aqueous compositions when compared to no such additive (None). The open time was especially improved when the (i) additive compositions included one or more phosphorus acid salt as in Examples 1S and 2S; compare Example 1S to Comparative Example 1; and compare Example 2S to Comparative Example 2.