Patent Issued for Acrylic-Peg Open Time Additive (USPTO 10,538,675)

2020 JAN 31 (NewsRx) -- By a News Reporter-Staff News Editor at Insurance Daily News -- According to news reporting originating from Alexandria, Virginia, by NewsRx journalists, a patent by the inventors Pastena, Gianna (Flanders, NJ); Gharapetian, Hrire (Ridgewood, NJ); Tilara, Navin (Roseland, NJ), filed on June 19, 2018, was published online on February 3, 2020.

The assignee for this patent, patent number 10,538,675, is Columbia Insurance Company (Omaha, Nebraska, United States).

Reporters obtained the following quote from the background information supplied by the inventors: “The open time of emulsion paint is the time interval during which freshly applied paint can be blended with subsequently applied paint without the appearance of lack of uniformity. Under one approach, open time can be extended by adding volatile organic compounds (VOC) such as glycols into the emulsion paint formulation. However, environmental regulations limit the level of VOCs in paint compositions.

“Currently, in many low VOC aqueous paints, open time becomes unacceptably short. Open time problems include, but are not limited to, skinning of left-open paints, not being able to cut back or blend in during brushing and rolling, and non-uniformity of sprayed surfaces. These problems are further exacerbated under fast dry conditions such as low humidity and high temperature.

“Some attempts to improve open time involve modifying the aqueous paint composition during the manufacturing process. For example, U.S. Pat. No. 5,270,380 discloses a method for forming an aqueous coating by combining a latex polymer and a modifying compound having complementary reactable groups. U.S. Pat. No. 7,071,261 relates to aqueous paint compositions comprising a dispersion of polymeric nanoparticles that include amine functionality and at least one multi-ethylenically-unsaturated monomer. U.S. Pat. No. 7,569,636 discloses an aqueous coating composition comprising, among other things, a crosslinkable oligomer that provides improved open time and a dispersed polymer (e.g., in the form of a polymer latex) that reduces time to tack free dryness of the composition. U.S. Pat. No. 6,040,368 discloses an aqueous coating composition comprising an emulsion polymer that includes a copolymerized ethylenically unsaturated monomer such as acetoacetoxyethyl methacrylate (AAEM) to improve open time. U.S. Pat. No. 6,610,776 discloses aqueous emulsion paints, where the film forming emulsion latex polymer is copolymerized with a polyethylene glycol or polypropylene glycol to improve open time. US 2007/0249780 concerns a stabilizer composition comprising an uncrosslinked AB type polymer, where the A component can be polyphenoxy glycidyl ether, methylphenyl glycidyl ether, ethylphenyl glycidyl ether and the B component can be polyactalpolyether, acrylate, acrylamide and polyethylene oxide.

“Some other attempts to improve open time use polyurethane. U.S. Pat. No. 6,303,189 discloses the addition of an aqueous polyurethane dispersion (PUD) to an aqueous coating composition having at least one film forming latex polymer, which is substantially un-crosslinked. US 2006/0148980 concerns polyurethane and polyurethane/acrylic hybrid dispersions formed from functional polyurethane and vinyl monomers including crosslinking agents to enhance the film formation and fast hardness development of the polyurethane.

“Other attempts are directed at paint additives. US 2009/0227705 to Bochnick et al. discloses a latex open time extender wherein the acrylic or vinyl latex particles are polymerized with crosslinkable monomers. The latex particles are less than about 150 nm in size. US 2012/0165428 to Tilara discloses an open time extender comprising a neutralized water-soluble polymer having a hydrophilic, hydrophobic and crosslinkable monomers with a solid content less than about 20 wt. %.

“Another method of improving open time involves the use of commercial paint extenders, which a consumer can add to a pre-manufactured aqueous latex paint. One latex-based paint extender on the market is Floetrol.RTM., which is commercially available from the Flood Company of Hudson, Ohio. However, when Floetrol.RTM. is added to paints, the aqueous paints still tend to form skins, which are indicative of poor open time. Floetrol.RTM. also negatively affects water sensitivity and paint flow leveling. Furthermore, Floetrol.RTM. also does not provide compatibility with many commercial low-VOC latex paints since it can cause quick syneresis and separation. Floetrol.RTM. also reduces the gloss of higher sheen paints, such as semigloss and high gloss paints. Other commercially available open time additives include WonderWet.TM. IV and Optifilm.TM. OT1200. The commercially available open time additives may also negatively affect properties of paint films, such as scrubability and water sensitivity.

“Thus, there remains a need for a paint open time extender that in addition to extending open time maintains/improves properties of paint films.”

In addition to obtaining background information on this patent, NewsRx editors also obtained the inventors’ summary information for this patent: “Hence, one embodiment of the present invention is directed to a polymeric paint additive that increases the open time and the flow and leveling of paint compositions, as well as, maintaining/improving paint film properties such as scrub resistance, water sensitivity, surfactant leaching and stain removal. The polymeric open time additive preferably has a high glass transition temperature, e.g., above 100.degree. C., as determined by the well-known Fox’s equation, and molecular weight of less than 20,000 Daltons (number average molecular weight). The particle size of the inventive polymeric open time additive is in the range of about 130 nm to about 230 nm (volume average), prior to being dissolved in a basic solution, e.g., ammonia and water, or in paint compositions with pH higher than 7. Hence, the polymeric paint open time additive is a non-film forming polymer at room temperature (RT) for interior paints or outdoor/environmental temperature for exterior paints. The inventive polymeric open time additive contributes to the film’s mechanical properties due to its hardness or high Tg.

“An embodiment of the present invention relates to an aqueous latex architectural composition comprising an optional opacifying pigment, a film forming latex resin, and a non-film forming polymeric open time additive. Preferably, the additive has a number average MW from about 7,000 Daltons to about 20,000 Daltons, and a Tg from about 100.degree. C. to about 200.degree. C. and the additive comprises at least one hydrophilic monomer and at least one polymerizable glycol monomer. Preferably, the aqueous latex architectural composition is basic and the additive is dissolved in the aqueous latex architectural composition.

“The number average MW of the open time additive may range from about 7,000 Daltons to about 20,000 Daltons, from about 8,000 Daltons to about 15,000 Daltons, or from about 9,000 Daltons to about 13,000 Daltons. The polydispersity index (PDI) may range from about 1.05 to about 1.35, preferably from about 1.10 to about 1.3 or from about 1.15 to about 1.25 or from about 1.10 to about 1.35. The acid number of the open time additive may range from about 130 to about 350, preferably about 180 to about 300, more preferably from about 200 to about 260 or from about 220 to about 250.

“The hydrophilicity of the open time additive has a Hansch parameter from about 0.500 to about 1.500, preferably from about 0.750 to about 1.350, more preferably from about 1.000 to about 1.250. Alternatively, the hydrophilicity of the inventive open time polymeric additive is expressed as a weighted solubility at a temperature from 20.degree. C. to 30.degree. C. that ranges from about 30 g/L to about 120 g/L, preferably from about 35 g/L to about 100 g/L and more preferably from about 40 g/L to about 80 g/L.

“An acceptable amount or range of solid additive added to the paint composition is about 10 lbs. of solid additive to 100 gallons of paint compositions. This amount of polymeric open time additive can vary from about 30 lbs. to about 60 lbs. per 100 gallons, or 20 lbs. to 70 lbs. per 100 gallons. Preferably, the total amount of the inventive polymeric open time additive (solid) makes up from about 1.5 wt. % to about 2.0 wt. % of the solids in the paint composition, more preferably from about 1.6 wt. % to about 1.9 wt. % or from about 1.65 wt. % to about 1.8 wt. %.

“The polymerizable glycol monomer in the open time additive preferably comprises a methoxy polyethylene glycol. The hydrophilic monomer in the open time additive may comprise methyl methacrylate (MMA) monomer and/or methacrylic acid (MAA) monomer.

“Another embodiment of the present invention is directed to a copolymer open time emulsion latex comprising a hydrophilic monomer and a polymerizable glycol monomer. Preferably, the latex has a MWn from about 7,000 Daltons to about 20,000 Daltons, a Tg from about 100.degree. C. to about 200.degree. C. and a volume average particle size from about 130 nm to about 230 nm. The latex is dissolvable in a basic aqueous solution.

“The volume average particle size may range from about 140 nm to about 220 nm or from about 150 nm to about 210 nm. The ranges of MW, Tg, PDI, acid number and hydrophilicity are the same as those described above and below.”

The claims supplied by the inventors are:

“We claim:

“1. An aqueous latex architectural composition comprising an optional opacifying pigment, a film forming latex resin, and a non-film forming polymeric open time additive, wherein said additive has a number average MW from about 7,000 Daltons to about 20,000 Daltons, and a Tg from about 100.degree. C. to about 200.degree. C. and said additive comprises at least one hydrophilic monomer and at least one polymerizable glycol monomer, wherein the aqueous latex architectural composition is basic and said additive is dissolved in the aqueous latex architectural composition.

“2. The aqueous latex architectural composition of claim 1, wherein the number average MW of the open time additive ranges from about 8,000 Daltons to about 15,000 Daltons.

“3. The aqueous latex architectural composition of claim 2, wherein the number average MW of the open time additive ranges from about 9,000 Daltons to about 13,000 Daltons.

“4. The aqueous latex architectural composition of claim 1, wherein an acid number of the open time additive ranges from about 130 to about 350.

“5. The aqueous latex architectural composition of claim 1, wherein the open time additive has a Hansch parameter from about 0.500 to about 1.500.

“6. The aqueous latex architectural composition of claim 1, wherein the open time additive has a Hansch parameter from about 0.750 to about 1.350.

“7. The aqueous latex architectural composition of claim 1, wherein open time additive has a Hansch parameter from about 1.000 to about 1.250.

“8. The aqueous latex architectural composition of claim 1, wherein the at least one polymerizable glycol monomer in the open time additive comprises a methoxy polyethylene glycol.

“9. The aqueous latex architectural composition of claim 1, wherein the open time additive has a polydispersity index from about 1.05 to about 1.35.

“10. The aqueous latex architectural composition of claim 1, wherein the open time additive has a polydispersity index from about 1.10 to about 1.3.

“11. The aqueous latex architectural composition of claim 1, wherein the open time additive has a polydispersity index from about 1.15 to about 1.25.

“12. The aqueous latex architectural composition of claim 1, wherein the open time additive has a polydispersity index from about 1.10 to about 1.35.

“13. The aqueous latex architectural composition of claim 1, wherein a total amount of solids in the non-film forming polymeric open time additive makes up from about 1.5 wt. % to about 2.0 wt. % of total solids in the paint composition.

“14. The aqueous latex architectural composition of claim 1, wherein a total amount of solids in the non-film forming polymeric open time additive makes up from about 1.6 wt. % to about 1.9 wt. % or from about 1.65 wt. % to about 1.8 wt. % of total solids in the paint composition.

“15. A copolymer open time emulsion latex comprising at least one hydrophilic monomer and at least one polymerizable glycol monomer, wherein the latex has a Mn from about 7,000 Daltons to about 20,000 Daltons, a Tg from about 100.degree. C. to about 200.degree. C. and a volume average particle size from about 130 nm to about 230 nm, wherein the latex is dissolvable in a basic aqueous solution.

“16. The copolymer open time emulsion latex of claim 15, wherein the number average MW ranges from about 8,000 Daltons to about 15,000 Daltons.

“17. The copolymer open time emulsion latex of claim 16, wherein the number average MW ranges from about 9,000 Daltons to about 13,000 Daltons.

“18. The copolymer open time emulsion latex of claim 15, wherein the volume average particle size ranges from about 140 nm to about 220 nm.

“19. The copolymer open time emulsion latex of claim 18, wherein the volume average particle size ranges from about 150 nm to about 210 nm.

“20. The copolymer open time emulsion latex of claim 15, wherein the open time additive has a Hansch parameter from about 0.500 to about 1.500.”

For more information, see this patent: Pastena, Gianna; Gharapetian, Hrire; Tilara, Navin. Acrylic-Peg Open Time Additive. U.S. Patent Number 10,538,675, filed June 19, 2018, and published online on February 3, 2020. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=10,538,675.PN.&OS=PN/10,538,675RS=PN/10,538,675

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