Adhesive coating compositions for secondary batteries

Abstract

A composition for a non-aqueous secondary battery adhesive layer. The composition includes a binder and a plurality of multistage polymeric particles. Each of the plurality of multistage polymeric particles includes a first-formed hard stage including a first polymer and a second-formed soft stage including a second polymer, the glass transition temperature of the first polymer (TgH) is at least 20˚C greater than the glass transition temperature of the second polymer (TgS), and each of the plurality of polymeric particles includes less than 10% by mass of an acid-functionalized monomer. A percentage distribution of acid-functionalized monomer in the second polymer (PDFM2) of this composition is greater than 50%, and the binder is a water-soluble polymer, a water-insoluble polymer, or a combination thereof. The composition is an adhesive coating composition for coating secondary battery separators.

Description

ADHESIVE COATING COMPOSITIONS FOR SECONDARY BATTERIES

[0001] FIELD OF THE INVENTION

[0002] The invention relates to adhesive coating compositions for separator membranes used in secondary batteries, separator membranes coated with such adhesive coating compositions, and secondary batteries including such separators. The separator coated with the adhesive coating composition described herein shows a good balance of adhesion to electrodes and permeability properties.

[0003] BACKGROUND

[0004] Reference to or discussion of any document or item of information in this specification is not an admission that the document or item of information, or any combination thereof was at the priority date, publicly available, known to the public, part of common general knowledge, or otherwise constitutes prior art under the applicable statutory provisions.

[0005] The separator is a key component of secondary batteries, such as lithium-ion batteries (LIB). The separator serves as a physical barrier between the cathode and the anode while allowing the transport of ions, such as lithium ions, between the cathode and the anode. Various separator technologies are used in the secondary battery industry. Of these, ceramic-coated microporous polyolefins such as polyethylene and polypropylene-based separators are widely favored due to their good thermal stability, mechanical strength, and chemical stability to the electrolytes used in secondary batteries, such as LIBs, as well as their ability to allow mass transport of the ions between the cathode andthe anode. However, the ceramic coated separators typically have poor adhesion to electrodes, which results in undesirable gap formation or misalignment between separators and electrodes during battery cell assembly and negatively impact battery performance.

[0006] The poor adhesion between electrodes and separators can be addressed by inclusion of an adhesive layer comprising functionalized polymeric particles to the surface of a separator. For example, US Patent Nos. 9,620,760; 10,141,557 and 11,319,391, US Publication No. 2022 / 0140437 and CN 11414549 all describe adhesive layers comprising multistage polymeric particles.

[0007] However, despite facilitating a more intimate contact between separators and electrodes, the addition of an adhesive layer compromises the permeability of the separators, hindering the ion transportation efficiency and ultimately leading to decreased battery performance. Therefore, it remains a challenge in the field to develop an adhesive layer that can have good adhesion to electrodes with minimal impact on separator permeability. Achieving the desired balance between good adhesion to electrodes and minimal impact on separator permeability is a significant problem that is yet to be overcome by the inclusion of adhesive coatings including standard multistage polymeric particles on these separators.

[0008] The invention described herein addresses these drawbacks of current separator technology by providing an adhesive layer composition comprising multistage polymeric particles having a higher acid concentration in the second-formed soft stage polymer. This adhesive coating composition unexpectedly balances adhesion of the separator to the electrodes with separator permeability.

[0009] SUMMARY

[0010] An embodiment is directed to a composition for a non-aqueous secondary battery adhesive layer, the composition comprising a binder and a plurality of multistage polymeric particles, wherein each of the plurality of multistage polymeric particles comprises a first formed hard stage comprising a first polymer and a second formed soft stage comprising a second polymer, wherein the glass transition temperature of the first polymer (Tgn) is at least 10°C greater, preferably at least 20°C greater, than the glass transition temperature of the second polymer (Tgs), wherein each of the plurality of polymeric particles comprises less than 10% by mass of an acid-functionalized monomer, wherein a percentage distribution of acid-functionalized monomer in the second polymer (PDFM2) is greater than 50%, preferably greater than 60%, and the PDFM2 is calculated from Equation 1:PDFM2 = percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer / (percentage of acid-functionalized monomer based on the total amount of monomers in the first polymer + percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer)... Equation 1,and wherein the binder is a latex polymer, a water-soluble polymer, or a combination thereof.

[0011] Another embodiment is directed to a method for forming a composition for a nonaqueous secondary battery adhesive layer, wherein the method comprises the steps of:

[0012] feeding a first monomer mixture to a reactor vessel; initiating a free radical polymerization of the first monomer mixture to form a first stage of the polymeric particles, the first-formed stage comprising a first polymer comprising the first monomer mixture as polymerized units; feeding a second monomer mixture to the reactor vessel; and polymerizing the second monomer mixture in the presence of the first-formed stage to form a second stage of the polymeric particles, the second stage comprising a second polymer comprising the second monomer mixture as polymerized units;

[0013] wherein: the composition comprises a binder and a plurality of multistage polymeric particles, wherein each of the plurality of multistage polymeric particles comprises the first polymer and the second polymer, wherein the glass transition temperature of the first polymer (Tgn) is at least 10°C greater, preferably at least 20°C greater, than the glass transition temperature of the second polymer (Tgs), wherein each of the plurality of polymeric particles comprises less than 10% by mass of an acid-functionalized monomer, wherein a percentage distribution of acid-functionalized monomer in the second polymer (PDFM2) is greater than 55%, and the PDFM2 is calculated from Equation 1:PDFM = percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer / (percentage of acid-functionalized monomer based on the total amount of monomers in the first polymer + percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer)... Equation 1,

[0014] and wherein the binder is a water-soluble polymer, a water-insoluble polymer, or a combination thereof.

[0015] Another embodiment is directed to a non-aqueous adhesive layer for secondary battery comprising the composition for a non-aqueous secondary battery adhesive layer described herein.

[0016] Another embodiment is directed to a separator comprising a substrate and the nonaqueous adhesive layer for secondary battery comprising the composition for a nonaqueous secondary battery adhesive layer described herein, wherein the non-aqueous adhesive layer is deposited on at least one surface of the substrate.

[0017] Another embodiment is directed to a second battery comprising a positive electrode, a negative electrode, and a separator a separator comprising a substrate and the non-aqueous adhesive layer for secondary battery comprising the composition for a non-aqueous secondary battery adhesive layer described herein.

[0018] Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.

[0019] DETAILED DESCRIPTION

[0020] Various aspects of the present invention will be described in detail herein. The following description is merely exemplary in nature and is in no way intended to limit the present disclosure or its application or uses.

[0021] Unless indicated otherwise, each individual feature, aspect or embodiment described herein is combinable with any other individual feature(s), aspect(s) orembodiment(s) that is / are described herein, without limitation. Such combinations are specifically contemplated as being within the scope of the present invention, regardless of whether they are explicitly described as a combination herein.

[0022] Any compositions described herein are intended to encompass compositions which consist of, consist essentially of, as well as comprise, the various constituents identified herein, unless explicitly indicated to the contrary

[0023] As used herein, the singular forms “a”, “an" and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. Additionally, the use of “or” is intended to include “and / or”, unless the context clearly indicates otherwise.

[0024] As used herein, the recitation of a numerical range for a variable is intended to convey that the variable can be equal to any value(s) within that range, any and all sub¬ ranges encompassed by the broader range, including any integer value(s) within that range as well as the upper and lower limits unless explicitly indicated to the contrary.

[0025] As used herein, "about" is a term of approximation that would be understood by one of skill in the art, and is Intended to include minor variations such as, for example, standard deviations associated with techniques commonly used to measure the amounts of the constituent elements or components of an alloy or composite material, or other properties and characteristics All of the values characterized by the above-described modifier "about," are also intended to include the exact numerical values disclosed herein. Moreover, all ranges include the upper and lower limits.

[0026] When a plurality of lower limits and a plurality of upper limits are provided herein with respect to ranges of a variable or ratio, the invention contemplates all ranges from any disclosed lower limit to any disclosed upper limit.

[0027] As used herein, the terms “latex” and “emulsified polymeric binder” may be considered to be interchangeable.

[0028] As used herein, the terms “water soluble” means that the material dissolves into water at 10 mg per liter or greater at 25°C, as opposed to “insoluble” which means less than 10 mg per liter of the substance will dissolve in water at 25°C.

[0029] As used herein, the term “theoretical Fox Equation glass transition temperature” or “theoretical Fox equation Tg” or “Tg” are used interchangeable, and refers to the estimated Tg of a polymer or copolymer calculated using the Fox equation. The Fox equation can be used to estimate the glass transition temperature of a random polymer or copolymer. The theoretical glass transition temperature Tg of a copolymer derived from monomers 1, 2,..., i can be calculated according to equation (I):-^ = Ei ^7 (I), where wi is the weight fraction of monomer i in the copolymer.

[0030] As used herein, the terms “layer” and “shell” and “stage” may be considered to be interchangeable.

[0031] Unless otherwise indicated, all percentages herein are weight percentages.

[0032] Technical and scientific terms used herein have the meaning commonly understood by one of skill in the art to which the present description pertains, unless otherwise defined.

[0033] Methods of preparing the emulsion polymers and the monomers useful to prepare useful as the binders in the present coating composition are known in the art (see, e.g., “Emulsion Polymerization: Theory and Practice” by D. C. Blackley published by Wiley in 1975, “Emulsion Polymerization” by F. A Bovey et al. published by Interscience Publishersin 1965, and “Emulsion Polymerization and Emulsion Polymers” by P. A. Lovell et al. published by Wiley Science in 1997).

[0034] Polymeric binder

[0035] The polymeric binder can be a latex polymer or a water soluble polymer, or a mixture thereof. The aqueous adhesive layer coating composition may comprise, consist of, or consist essentially of about 0.01 wt% to about 30 wt%, or about 0.05 wt% to about 25 wt%, or about 0.1 wt% to about 20 wt%, or about 0.5 wt% to about 15 wt%, or about 1 wt% to about 10 wt%, or about 2 wt% to about 7 wt%, and the like, of the at least one polymeric binder, based on a total dry weight of the adhesive layer coating. The amount of the polymer binder can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0036] The polymeric binder may be in a form of a latex, i.e. an aqueous emulsified polymer. The polymeric binder may comprise, consist of, or consist essentially of, as polymerized monomers, any ethylenically unsaturated monomer. Non-limiting examples are (meth)acrylates, vinyl esters, vinyl aromatic monomers, styrene, and substituted styrene, (meth) acrylamide and derivatives thereof, olefins, and combinations thereof.

[0037] Non-limiting examples of suitable alkyl (meth)acrylates are alkyl esters of (meth) acrylic acid, or (eth)acrylic acid, for example. Such acrylate monomers may be C1-C22 linear, cyclic or branched alkyl esters of (meth) acrylic acid, or (eth)acrylic acid. Nonlimiting examples include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, cyclohexyl (meth)acrylate, allyl methacrylate, 2-ethylhexyl acrylate; isooctyl methacrylate and iso-octyl acrylate, lauryl acrylate and lauryl methacrylate, stearyl acrylate and stearyl methacrylate, isobornyl acrylate and isobornyl methacrylatemonomers. According to an embodiment, the ethylenically unsaturated monomer comprises at least one of vinyl aromatic monomers, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethyl hexyl acrylate, (meth)acrylic acid, or a combination thereof.

[0038] Other suitable monomers include but are not limited to ethylene, propylene, mono-ethylenically unsaturated carboxylic acid monomer, phosphorous-containing monomer, sulfur-containing monomer, silane co-monomers, and mixtures thereof.

[0039] These other suitable monomers may include various carboxylic acids such as itaconic acid, and esters thereof, various esters of versatic acid, methoxyethyl acrylate and methoxyethyl methacrylate, 2-ethoxy ethyl acrylate and 2-ethoxyethyl methacrylate, and combinations thereof.

[0040] Also suitable as monomers are acrylonitrile; vinyl cyanides; vinylpyrrolidone; polypropylene glycol mono(meth)acrylate or polyethylene glycol mono(meth)acrylate; phosphorous-based monomers including but are not limited to phosphoalkyl (meth)acrylates or acrylates, phosphoalkyl (meth)acrylamides or acrylamides, phosphoalkyl crotonates, phosphoalkyl maleates, phosphoalkyl fumarates, phosphodialkyl (meth)acrylates, phosphodialkyl crotonates, vinyl phosphates and (meth)allyl phosphate, phosphate esters of polypropylene glycol mono(meth)acrylate or polyethylene glycol mono(meth)acrylate, polyoxyethylene allyl ether phosphate, vinyl phosphonic acid. Suitable sulfur-based monomers include, but are not limited to, vinyl-and allyl- sulfonic or sulfuric acids, sulfoethyl (meth)acrylate, aryl- sulfonic or sulfuric acids, (meth)acrylamidoethane- sulfonic or sulfuric acids, methacrylamido-2-methyl propane- sulfonic or sulfuric acids, and the alkali metal salts of sulfonic and sulfuric acids.Suitable optional silane co-monomers include, but are not limited to methacryloxypropyl trimethoxysilane, methacryloxypropyl triethoxysilane, methacryloxypropyl tripropoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, and vinyltriethoxysilane.

[0041] Crosslinkable co-monomers may also optionally be present in the polymeric binder. These crosslinkable co-monomers may be of two different types. The first type is crosslinkable co-monomers that include two or more sites of ethylenic unsaturation such that the crosslinks are formed during polymerization of the polymeric binder a). The second type of crosslinkable comonomer is those that include, in addition to an ethylenic unsaturation ((meth)acrylate, allyl or vinyl functional groups), at least one moiety that is capable of reacting with a separate crosslinking compound that may be included in the one-part aqueous composition to form a crosslink.

[0042] Suitable crosslinkable co-monomers with two or more sites of ethylenic unsaturation include, but are not limited to, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, trimethylol propane trimethacrylate, 1,3-butyleneglycol dimethacrylate, and 1, 4-butyleneglycol dimethacrylate, hexanediol dimethacrylate, divinyl benzene, diallyl phthalate, and the like.

[0043] Crosslinkable co-monomers that are capable of reacting with a separate crosslinking agent that may be included in the aqueous coating composition may be selected from, for example, acetoacetate co-monomers containing (meth)acrylate, allyl or vinyl functional groups including but not limited to acetoacetate moieties such as: 2-acetoacetoxyethyl (meth)acrylate, 3-acetoacetoxypropyl (meth)acrylate, 4-acetoacetoxybutyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, 3-cyanoacetoxypropyl (meth)acrylate, 4-cyanoacetoxybutyl (meth)acrylate, N(2-acetoacetoxyethyl) (meth)acrylamide, allyl acetoacetate, 2,3-di(acetoacetoxy)propyl (meth)acrylate, vinyl acetoacetate and combinations thereof. Also suitable are comonomers containing a keto group such as diacetone acrylamide. Non-limiting examples of such crosslinkable monomers are acetoacetoxyethyl methacrylate and diacetone acrylamide. Water-soluble crosslinking agents that can react with certain moieties of these second type of crosslinkable comonomers may also optionally be included in the aqueous coating composition.

[0044] The water-soluble crosslinking agents effect post crosslinking during film formation and drying by reacting with the crosslinkable moieties on the second type of crosslinkable co-monomers. For example, such crosslinking agents containing at least two hydrazine and / or hydrazide groups may be included in certain embodiments of the aqueous coating composition. Preferred such separate crosslinking agents are water soluble. Non-limiting examples include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide and / or itaconic acid dihydrazide. Adipic acid dihydrazide (ADH) is a particular example of such a water-soluble cross- linking agent for use in the coating compositions herein, especially those produced from monomer compositions containing diacetone acrylamide (DAAM). Other suitable water-soluble crosslinking agents are compounds which contain at least two amine functional moieties such as ethylene diamine and hexamethylene diamine. Such cross-linking agents are especially useful in combination with polymers comprising 1,3- dicarbonyl groups as the crosslinkable moiety, such as acetoacetoxyethyl methacrylate (AAEM).

[0045] The Tg of the latex polymer binder may be from about -60°C to about 60°C, or from about -50°C to about 40°C, or from about -50°C to about 30°C, or from about -50°C to about 20°C, and the like. The Tg of the latex polymer binder can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0046] The polymer binder can also be a water-soluble polymer. Nonlimiting examples of a water-soluble polymer as described herein can include cellulose-based polymers such as carboxymethyl cellulose, methyl cellulose, and hydroxypropyl cellulose, and ammonium salts and alkali metal salts thereof; such as modified poly(meth)acrylic acid and ammonium salts and alkali metal salts thereof; such as polyvinyl alcohol compounds such as (modified) polyvinyl alcohol, a copolymer of acrylic acid or acrylic acid salt and vinyl alcohol, and a copolymer of maleic anhydride, maleic acid, or fumaric acid and vinyl alcohol; such as polyethylene glycol, polyethylene oxide, polyvinylpyrrolidone, modified polyacrylic acid, oxide starch, phosphoric acid starch, casein, and a variety of starches. As used herein, a "(modified) polymer” includes both "unmodified polymers” and “modified polymers”.

[0047] The polymeric binder can also be a mixture of latex and water soluble polymer.

[0048] First-formed Hard Stage Polymer

[0049] The first-formed (hard stage) polymer may have a theoretical Fox equation Tgn of from about 10°C to about 1150°C, or from about 10°C to about 75°C, or from about 10°C to about 50°C, or from about 10°C to about 25°C, or from about 20°C to about 100°C, or from about 20°C to about 75°C, or from about 20°C to about 50°C, or from about 30°C to about 100°C, or from about 30°C to about 75°C, or from about 30°C to about 50°C, or from about 35°C to about 100°C, or from 35°C to 90°C, or from about 35°C to about 75°C,or from about 35°C to about 50°C, or from about 40°C to about 100°C, or from about 40°C to about 80°C, or from about 50°C to about 60°C, or from about 45°C to about 100°C, or from about 45°C to 70°C, or from about 45°C to about 60°C, or from 50°C to about 100°C, or from about 50°C to about 80°C, or from about 50°C to about 60°C, about 10°C, about 12.5°C, about 15°C, about 17.5°C, about 20°C, about 25°C, about 30°C, about 35°C, about 37.5°C, about 40°C, about 42.5°C, about 45°C, about 47.5°C, about 50°C, about 51 °C, about 52°C, about 53°C, about 54°C, about 55°C, about 56°C, about 57°C, about 58°C, about 59°C, about 60°C, about 70°C, about 80°C, about 90°C, about 100°C, and the like. The Tgn value can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0050] Second-formed Soft Stage Polymer

[0051] The second (soft stage) polymer may have a theoretical Fox equation Tgs of from about 120°C to about 0°C, or from about 60DC to about -10°C, or from about 50DC to about -20°C, or from about 40°C to about -30°C, or from about 30°C to about -40°C, or from about 15°C to about -40°C, or from about 10°C to about -30°C, or from about 10°C to about -50°C, or from about 10°C to about -40°C, or from about 10°C to about -30°C, or from about 10°C to about -20°C, or from about 10°C to about -10°C, or from about 5°C to about -50°C, or from about 5°C to about -40°C, or from 5°C to about -30°C, or from about 5°C to about -20°C, or from about 0°C to about -45DC, or from about 0°C to about -20°C, or from about -5°C to about -40°C, or from about -5°C to about -30°C, or from about -5°C to about -20°C, or from about -10°C to about -40°C, or from about -10°C to about -20°C, or from about -10°C to about -30°C, or from about -10°C to about -40°C, or from about -15°C to about -45°C, or from about -15°C to about -35°C, or from about -15°C to about -25°C, or from about -20°C to about -50°C, or from about -20°C to about -40°C, or from about -20°C to about -30°C, about 80°C, about 70°C, about60°C, about 50°C, about 40°C, about 30°C, about 20°C, about 10°C, about 0°C, about -10°C, about -20°C, about -25°C, about -30°C, about -40°C, about -50°C, and the like. The Tgs value can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0052] Adjusting the amounts of different monomers in a copolymer can be used to tailor the Tg value of the copolymer, and the soft and hard stage polymer may have two different Tg values. The various monomers described herein can be included in the first- and second-stage polymer, respectively, such that Tgn is at least 10°C greater, preferably at least 20°C greater, than Tgs.

[0053] The multi-stage particles may include, based on the total dry weight of the first and second polymers, from about 10 wt% to 90 wt%, or from about 10 wt% to about 75 wt%, or from about 10 wt% or about 50 wt%, or from about 10 wt% to about 25 wt%, or from about 20 wt% to 80 wt%, or from about 20 wt% to about 60 wt%, or from about 20 wt% to about 40 wt%, from about 30 wt% to about 70 wt%, or from about 30 wt% to about 60 wt%, from about 30 wt% to about 50 wt%, from about 30 wt% to about 40 wt%, from about 40 wt% to about 60 wt%, or from about 40 wt% to about 50 wt%, or from about 50 wt% to about 60 wt%, or from about 50 wt% to about 75 wt%, or from about 45 wt% to about 55 wt%, or about 15 wt%, or about 25 wt%, or about 30 wt%, or about 40 wt%, or about 41 wt%, or about 42 wt%, or about 43 wt%, or about 44 wt%, or about 44.2 wt%, or about 44.4 wt%, or about 44.6 wt%, or about 44.8 wt%, or about 45 wt%, or about 60 wt%, or about 75 wt%, and the like, of the first polymer. The weight percentage of the first polymerparticles can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0054] The multi-stage particles may include, based on a total dry weight of the first and second polymers, from about 90 wt% to 10 wt%, or from about 90 wt% to about 25 wt%, or from about 90 wt% to about 50 wt%, or from about 90 wt% to about 75 wt%, or from about 80 wt% to about 10 wt%, or from about 80 wt% to about 20 wt%, or from about 80 wt% to about 30 wt%, or from about 80 wt% to about 50 wt%, or from about 70 wt% to about 10 wt%, or from about 70 wt% to about 20 wt%, or from about 70 wt% to about 30 wt%, or from about 70 wt% to about 40 wt%, or about 70 wt% to about 50 wt%, or from about 60 wt% to about 10 wt%, or from about 60 wt% to about 30 wt%, or from about 60 wt% to about 40 wt%, or from about 55 wt% to about 15 wt%, or from about 55 wt% to about 25 wt%, or from about 55 wt% to about 45 wt%, or about 85 wt%, or about 80 wt%, or about 75 wt%, or about 70 wt%, or about 65 wt%, or about 60 wt%, or about 55 wt%, or about 50 wt%, or about 45 wt%, or about 40 wt%, or about 35 wt%, or about 30 wt%, or about 25 wt%, or about 20 wt%, or about 15wt%, or about 10 wt%, and the like, of the second polymer. The weight percentage of the second polymer particles can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0055] In one embodiment, the total of the weight % of the soft polymer phase and the weight % of the hard polymer phase is 100%.

[0056] A total solids content of the two-stage polymer content may range from about 5 wt% to about 70 wt%, or from about 15 wt% to about 65 wt%, or from about 20 wt% to about 60 wt%, or from about 45 wt% to about 55 wt%, or about 6 wt%, or about 16 wt%, or about 26 wt%, or about 38 wt%, or about 42 wt%, or about 44 wt%, or about 46 wt%,or about 48 wt%, and the like. The total solids content can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0057] The D50 particle size of the polymer particles can vary. In various embodiments of the invention, the particles have an average diameter of less than about 10 pm, or less than about 5 pm, or less than about 1 pm, or less than about 800 nm, or less than about 700 nm, or less than about 6000 nm, or less than about 500 nm, or less than about 400 nm, or about 5 pm, or about 1 pm, or about 800 nm, or about 700 nm, or about 600 nm, or about 500 nm, or about 400 nm, or about 350 nm, or about 300 nm, or about 250 nm, and the like. In various embodiments of the invention, the particles have an average diameter of more than about 50 nm, more than about 100 nm, more than about 150 nm, more than about 200 nm. In various embodiments of the invention, the particles have an average diameter ranging from about 100 nm to about 5 pm, or from about 150 nm to about 2 pm, or from about 200 nm to about 1 pm, or from about 300 nm to about 500 nm, and the like. The size of the polymer particles can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges. The D50 particle size is a measure of the particle size distribution corresponding to the cumulative frequency 50%, i.e., the particle size at which 50% of the particles are larger and 50% are smaller than the D50 value.

[0058] Particle size and particle size distribution may be analyzed using Nanotrac UPA 150 (from Microtrac Inc.) to provide volume-averaged particle sizes based on dynamic light scattering techniques. Typically, the multi-stage particles may be approximately spherical in shape, although oblong, oval, teardrop or other shapes are also possible. Inan embodiment of the invention, the soft polymer phase is an inner (core) phase within the polymer particles and the hard polymer phase is an outer (shell) phase.

[0059] Free Radical Polymerizable Ethylenically Unsaturated Monomers Not Containing Acid Groups i) and vi):

[0060] The first polymer of the multi-stage polymer particles may comprise, as polymerized units based on the dry weight of the first polymer, i) one or more free radical polymerizable ethylenically unsaturated monomers not containing acid groups. The second polymer of the multi-stage polymer particles may comprise, as polymerized units based on the dry weight of the second polymer, vi) one or more free radical polymerizable ethylenically unsaturated monomers not containing acid groups.

[0061] Non-limiting examples of suitable polymerizable ethylenically unsaturated monomers not containing acid groups i) and vi) that may be used to form the first-formed soft stage and the second-formed hard stage, respectively, of the multi-stage polymer particles include: branched and linear (C1-C20) alkyl or (C3-C20) alkenyl esters of (meth)acrylic acid, such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2 ethylhexyl (meth)acrylate, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth)acrylate, stearyl (meth)acrylate and the like, vinyl aromatic monomers such as styrene, a-methyl styrene, p-methyl styrene, t-butyl styrene, or vinyltoluene, olefins such as ethylene, vinyl acetate, vinyl chloride, vinylidene chloride, (meth)acrylonitrile, and (meth)acrylamide, for example. Preferred monomers are methyl (meth)acrylate, 2 ethylhexyl (meth)acrylate, styrene, butyl (meth)acrylate, ethyl (meth)acrylate, benzyl (meth)acrylate, glycidyl methacrylate, 3-(methacryloyloxy)propyltrimethoxysilane,vinyltrimethoxysilane and mixtures thereof. Most preferred monomers are styrene, methyl methacrylate, 2 ethylhexyl acrylate, butyl acrylate, and mixtures thereof.

[0062] Mixtures of any or all of the above free-radical polymerizable monomers may be included in either or both of the first and second polymers.

[0063] In one embodiment, the free radical polymerizable ethylenically unsaturated monomers i) and iv) of the first and second polymers, respectively, may be the same. In another embodiment, the second monomer mixture of the second polymer differs from the first monomer mixture of the first polymer in at least one of type or relative amount of the free radical polymerizable monomer.

[0064] The one or more free radical polymerizable ethylenically unsaturated monomers in the first polymer may be selected from the group consisting of one or more alkyl(meth)acrylates, styrene, and mixtures thereof. The one or more free radical polymerizable ethylenically unsaturated monomers in the second polymer are selected from the group consisting of one or more alkyl(meth)acrylates, styrene, and mixtures thereof.

[0065] According to some embodiments, preferred monomers are methyl (meth)acrylate, 2 ethylhexyl (meth)acrylate, styrene, butyl (meth)acrylate, ethyl (meth)acrylate, benzyl (meth)acrylate and mixtures thereof. According to some embodiments, most preferred monomers are styrene, methyl methacrylate, 2 ethylhexyl acrylate, butyl acrylate, butyl methacrylate and mixtures thereof.

[0066] In an embodiment, the free radical polymerizable ethylenically unsaturated monomer i) may be included in the first polymer in an amount of from about 70 wt% to about 99.98 wt%, or from about 75 wt% to about 95 wt%, or from about 80 wt% to about90 wt%, or about 72 wt%, or about 74 wt%, or about 76 wt%, or about 78 wt%, or about 82 wt%, or about 84 wt%, or about 86 wt%, or about 88 wt%, or about 92 wt%, or about 94 wt%, or about 96 wt%, or about 98 wt%, and the like, based on the dry weight of the first polymer. The amount of the free radical polymerizable ethylenically unsaturated monomer i) in the first polymer can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0067] In an embodiment, the free radical polymerizable ethylenically unsaturated monomer vi) may be included in the second polymer in an amount from about 65 wt% to about 99.98 wt%, from about 70 wt% to about 98 wt%, from aout 75 wt% to about 97 wt%, from about 80 wt% to about 96 wt%, or from about 85 wt% to about 95 wt%, or about 68 wt%, or about 72 wt%, or about 74 wt%, or about 76 wt%, or about 82 wt%, or about 84 wt%, or about 86 wt%, or about 88 wt%, or from about 92 wt% to about 98 wt%, or from about 94 wt% to about 96 wt%, or about 91 wt%, or about 93 wt%, or about 95 wt%, or about 97 wt%, or about 99 wt%, and the like, based on the dry weight of the second polymer. The amount of the free radical polymerizable ethylenically unsaturated monomer vi) in the second polymer can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0068] Acid-containing functional monomers

[0069] The first polymer of the multi-stage polymer particles may comprise, as polymerized units based on the dry weight of the first polymer, ii) one or more acidcontaining functional monomers. The second polymer of the multi-stage polymer particles may comprise, as polymerized units based on the dry weight of the second polymer, vii) one or more acid monomers.

[0070] Non-limiting examples of suitable acid-containing functional monomers ii) and vii) that may be used to form the first and second polymers, respectively, include ethylenically unsaturated monomers containing carboxylic acids such as acrylic acid, methacrylic, itaconic acid, maleic acid, fumaric acid; ethylenically unsaturated monomers containing phosphoric acids such as vinyl phosphonic acid, phosphoalkyl (meth)acrylates or acrylates, vinyl phosphates and (meth)allyl phosphate, phosphate esters of polypropylene glycol mono(meth)acrylate or polyethylene glycol mono(meth)acrylate, polyoxyethylene allyl ether phosphate; ethylenically unsaturated monomers containing sulfonic acids such as vinyl- and allyl- sulfonic or sulfuric acids, sulfoethyl (meth)acrylate, aryl- sulfonic or sulfuric acids, (meth)acrylamidoethane- sulfonic or sulfuric acids, methacrylamido-2-methyl propane- sulfonic or sulfuric acids. In preferred embodiments, the acid monomer may be selected from acrylic acid, methacrylic acid, or a mixture thereof.

[0071] Mixtures of any or all of the above acid-containing monomers may be included in the first and second polymers.

[0072] In an embodiment, the acid-containing monomer ii) may be included in the first polymer in an amount of from about 0.01 wt% to about 10 wt%, from about 0.1 wt% to about 10 wt%, or from about 0.5 wt% to about 10 wt%, or from about 1 wt% to about 10 wt%, or from about 1.5 wt% to about 10 wt%, or from about 2 wt% to about 10 wt%, or from about 2.5 wt% to about 10 wt%, or from about 3 wt% to about 9.5 wt%, or from about 3.5 wt% to about 9 wt%, or from about 4 wt% to about 8.5 wt%, or from about 4.5 wt% to about 8 wt%, or from about 5 wt% to about 7.5 wt%, or about 0.75 wt%, or about 1.25 wt%, or about 1.75 wt%, or about 2.25 wt%, or about 2.75 wt%, or about 3.25 wt%, orabout 3.75 wt%, or about 4.25 wt%, or about 4.75 wt%, or about 5.25 wt%, or about 5.5 wt%, or about 5.75 wt%, or about 6.25 wt%, or about 6.5 wt%, or about 6.75 wt%, or about 7.25 wt%, or about 7.75 wt%, or about 8.25 wt%, or about 8.5 wt%, or about 8.75 wt%, or about 9.25 wt%, or about 9.75 wt%, or about 10.5 wt%, and the like, based on the dry weight of the first polymer. The amount of the acid monomer ii) can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0073] In an embodiment, the acid monomer vii) may be included in the second polymer in an amount of from about 0.01 wt% to about 20 wt%, from about 0.1 wt% to about 18 wt%, or from about 0.5 wt% to about 16 wt%, or from about 1 wt% to about 14 wt%, or from about 1.5 wt% to about 12 wt%, or from about 2 wt% to about 11 wt%, or from about 2.5 wt% to about 10 wt%, or from about 3 wt% to about 9.5 wt%, or from about 3.5 wt% to about 9 wt%, or from about 4 wt% to about 8.5 wt%, or from about 4.5 wt% to about 8 wt%, or from about 5 wt% to about 7.5 wt%, or about 0.75 wt%, or about 1.25 wt%, or about 1.75 wt%, or about 2.25 wt%, or about 2.75 wt%, or about 3.25 wt%, or about 3.75 wt%, or about 4.25 wt%, or about 4.75 wt%, or about 5.25 wt%, or about 5.5 wt%, or about 5.75 wt%, or about 6.25 wt%, or about 6.5 wt%, or about 6.75 wt%, or about 7.25 wt%, or about 7.75 wt%, or about 8.25 wt%, or about 8.5 wt%, or about 8.75 wt%, or about 9.25 wt%, or about 9.75 wt%, or about 10.5 wt%, or about 11 wt%, or about 11.5 wt%, and the like, based on the dry weight of the second polymer. The amount of the acidcontaining monomer can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0074] Free Radical Polymerizable Monomer Having a Crosslinkable Functionality (iii) and (vii):

[0075] Free radical polymerizable monomer having a crosslinkable functionality may also optionally be present in the first and second polymers. The first polymer of the multi-stage polymer particles may optionally comprise, as polymerized units based on the dry weight of the first polymer, iii) one or more free-radical polymerizable monomers having a crosslinkable functionality. The second polymer of the multi-stage polymer particles may optionally comprise, as polymerized units based on the dry weight of the second polymer, viiii) one or more acid free-radical polymerizable monomers having a crosslinkable functionality.

[0076] These crosslinkable co-monomers may be of two different types. The first type are crosslinkable co-monomers that include two or more sites of ethylenic unsaturation such that the crosslinks are formed during polymerization of the two-stage polymer. The second type of crosslinkable comonomers are those that include, in addition to an ethylenic unsaturation ((meth)acrylate, allyl or vinyl functional groups), at least one moiety that is capable of reacting with a separate crosslinking compound that may be included in the one-part aqueous composition to form a crosslink.

[0077] Suitable crosslinkable co-monomers with two or more sites of ethylenic unsaturation include, but are not limited to, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, trimethylol propane trimethacrylate, 1,3-butyleneglycol dimethacrylate, and 1, 4-butyleneglycol dimethacrylate, hexanediol dimethacrylate, divinyl benzene, diallyl phthalate, and the like.

[0078] Crosslinkable co-monomers that are capable of reacting with a separate crosslinking agent that may be included in the aqueous coating composition may be selected from, for example, acetoacetate co-monomers containing (meth)acrylate, allyl orvinyl functional groups including but not limited to acetoacetate moieties such as: 2-acetoacetoxyethyl (meth)acrylate, 3-acetoacetoxypropyl (meth)acrylate, 4-acetoacetoxybutyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, 3-cyanoacetoxypropyl (meth)acrylate, 4-cyanoacetoxybutyl (meth)acrylate, N(2-acetoacetoxyethyl) (meth)acrylamide, allyl acetoacetate, 2,3-di(acetoacetoxy)propyl (meth)acrylate, vinyl acetoacetate and combinations thereof. Also suitable are comonomers containing a keto group such as diacetone acrylamide. Non-limiting particular examples of such crosslinkable monomers are acetoacetoxyethyl methacrylate and diacetone acrylamide. Water-soluble crosslinking agents that can react with certain moieties of these second type of crosslinkable comonomers may also optionally be included in the aqueous coating composition. These water-soluble crosslinking agents effect post crosslinking during film formation and drying by reacting with the crosslinkable moieties on the second type of crosslinkable co-monomers. For example, such crosslinking agents containing at least two hydrazine and / or hydrazide groups may be included in certain embodiments of the aqueous coating composition. Preferred such separate crosslinking agents are water soluble. Non-limiting examples include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide and / or itaconic acid dihydrazide. Adipic acid dihydrazide (ADH) is a particular example of such a water-soluble cross- linking agent for use in the coating compositions herein, especially those produced from monomer compositions containing diacetone acrylamide (DAAM). Other suitable water-soluble crosslinking agents are compounds which contain at least two amine functional moieties such as ethylenediamine and hexamethylene diamine. Such cross-linking agents are especially useful in combination with polymers comprising 1,3- dicarbonyl groups as the crosslinkable moiety, such as acetoacetoxyethyl methacrylate (AAEM).

[0079] In an embodiment, the free radical polymerizable monomer having a crosslinkable functionality iii) may be included in the first polymer in an amount of from about 0 wt% to about 10 wt%, from about 0.01 wt% to about 10 wt%, from about 0.1 wt% to about 8 wt%, or from about 0.5 wt% to about 6 wt%, or from about 1 wt% to about 4 wt%, or from about 1.5 wt% to about 2 wt%, or about 0.75 wt%, or about 1.25 wt%, or about 1.75 wt%, or about 2.25 wt%, or about 2.75 wt%, or about 3.25 wt%, or about 3.75 wt%, or about 4.25 wt%, or about 4.75 wt%, or about 5.25 wt%, or about 5.5 wt%, or about 5.75 wt%, or about 6.25 wt%, or about 6.5 wt%, or about 6.75 wt%, or about 7.25 wt%, or about 7.75 wt%, or about 8.25 wt%, or about 8.5 wt%, or about 8.75 wt%, or about 9.25 wt%, or about 9.75 wt%, and the like, based on the dry weight of the first polymer. The amount of the free radical polymerizable monomer having a crosslinkable functionality iii) can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0080] In an embodiment, the free radical polymerizable monomer having a crosslinkable functionality viii) may be included in the second polymer in an amount of from about 0 wt% to about 10 wt%, from about 0.01 wt% to about 10 wt%, from about 0.1 wt% to about 8 wt%, or from about 0.5 wt% to about 6 wt%, or from about 1 wt% to about 4 wt%, or from about 1.5 wt% to about 2 wt%, or about 0.75 wt%, or about 1.25 wt%, or about 1.75 wt%, or about 2.25 wt%, or about 2.75 wt%, or about 3.25 wt%, or about 3.75 wt%, or about 4.25 wt%, or about 4.75 wt%, or about 5.25 wt%, or about 5.5 wt%, or about 5.75wt%, or about 6.25 wt%, or about 6.5 wt%, or about 6.75 wt%, or about 7.25 wt%, or about 7.75 wt%, or about 8.25 wt%, or about 8.5 wt%, or about 8.75 wt%, or about 9.25 wt%, or about 9.75 wt%, and the like, based on the dry weight of the second polymer. The amount of the free radical polymerizable monomer having a crosslinkable functionality viii) can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0081] Anionic Surfactant

[0082] The first polymer of the multi-stage polymer particles may comprise, as polymerized units based on the dry weight of the first polymer, iv) one or more anionic surfactants. The second polymer of the multi-stage polymer particles may comprise, as polymerized units based on the dry weight of the second polymer, ix) one or more anionic surfactants.

[0083] The anionic surfactant iv) may be included in the first polymer in an amount of at least about 0.001 wt%, such as at least about 0.005 wt%, such as at least about 0.01 wt%, such as at least about 0.05 wt%, such as at least about 0.1 wt%, such as at least about 0.5 wt%, such as at least about 1 wt%, such as at least about 1.5 wt%, such as about 0.001 wt% to about 5 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 3 wt%, such as about 0.01 wt% to about 1 wt%, such as about 0.1 wt% to about 10 wt%, such as about 0.1 wt% to about 5 wt%, such as about 1 wt% to about 10 wt%, such as about 1 wt% to about 5 wt%, based on the total weight of the monomers. The amount of the anionic surfactant iv) can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0084] The anionic surfactant ix) may be included in the second polymer in an amount of at least about 0.001 wt%, such as at least about 0.005 wt%, such as at least about 0.01 wt%, such as at least about 0.05 wt%, such as at least about 0.1 wt%, such as at least about 0.5 wt%, such as at least about 1 wt%, such as at least about 1.5 wt%, such as about 0.001 wt% to about 2.5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 2 wt%, such as about 0.01 wt% to about 1 wt%, such as about 0.1 wt% to about 10 wt%, such as about 0.1 wt% to about 5 wt%, such as about 1 wt% to about 10 wt%, such as about 1 wt% to about 5 wt%, based on the total weight of the monomers. The amount of the anionic surfactant iv) can be equal to any integer value(s) within any of these ranges, including the endpoints of these ranges.

[0085] Examples of suitable anionic surfactants include, but are not limited to, alkylbenzenesulfonic acids, alkaline earth metal alkylbenzenesulfonates, sulfonated fatty acids, sulfonated olefins, sulfonated diphenyl ethers, sulfosuccinates, fatty alcohol sulfates, alkylphenol sulfates, alkyl polyglycol ether sulfates, fatty alcohol ether sulfates, fatty alcohol phosphates, alkylphenol phosphates, alkyl polyglycol ether phosphates, alkyl polyalkylene oxide phosphates, fatty alcohol ether phosphates and mixtures thereof.

[0086] Specific examples of suitable anionic surfactants include, but are not limited to, sodium lauryl sulfate, sodium dodecylbenzenesulfonate, potassium stearate, sodium dioctyl sulfosuccinate, sodium dodecyldiphenyloxide disulfonate, nonylphenoxyethylpoly(l)ethoxyethyl sulfate ammonium salt, sodium styrene sulfonate, sodium dodecyl allyl sulfosuccinate, sodium or ammonium salts of phosphate esters of ethoxylated nonylphenol, sodium octoxynol-3-sulfonate, sodium cocoyl sarcocinate,sodium 1-alkoxy-2-hydroxypropyl sulfonate, sodium a-olefin (C14-C16)sulfonate, sulfates of hydroxyalkanols, tetrasodium N-(1,2-dicarboxy ethyl)-N-octadecylsulfosuccinamate, disodium N-octadecylsulfosuccinamate, disodium alkylamido polyethoxy sulfosuccinate, disodium ethoxylated nonylphenol half ester of sulfosuccinic acid and the sodium salt of tert -octylphenoxyethoxypolyethoxyethyl sulfate.

[0087] Non-ionic Surfactant

[0088] The first polymer of the multi-stage polymer particles may comprise, as polymerized units based on the dry weight of the first polymer, v) one or more non-ionic surfactants. The second polymer of the multi-stage polymer particles may comprise, as polymerized units based on the dry weight of the second polymer, x) one or more nonionic surfactants.

[0089] The non-ionic surfactant v) may be optional or may be included in the first polymer in an amount of at least about 0.001 wt%, such as at least about 0.005 wt%, such as at least about 0.01 wt%, such as at least about 0.05 wt%, such as at least about 0.1 wt%, such as at least about 0.5 wt%, such as at least about 1 wt%, such as at least about 1.5 wt%, such as about 0.0 wt% to about 5 wt%, such as about 0.001 wt% to about 5 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 5 wt%, such as about 0.01 wt% to about 3 wt%, such as about 0.01 wt% to about 1 wt%, such as about 0.1 wt% to about 10 wt%, such as about 0.1 wt% to about 5 wt%, such as about 1 wt% to about 10 wt%, such as about 1 wt% to about 5 wt%, based on the total weight of the monomers. The amount of the non-ionic surfactant v) can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0090] The non-ionic surfactant x) may be optional or may be included in the second polymer in an amount of at least about 0.001 wt%, such as at least about 0.005 wt%, such as at least about 0.01 wt%, such as at least about 0.05 wt%, such as at least about 0.1 wt%, such as at least about 0.5 wt%, such as at least about 1 wt%, such as at least about 1.5 wt%, such as about 0.0 wt% to about 2.5 wt%, such as about 0.001 wt% to about 2.5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 2.5 wt%, such as about 0.01 wt% to about 2 wt%, such as about 0.01 wt% to about 1 wt%, such as about 0.1 wt% to about 10 wt%, such as about 0.1 wt% to about 5 wt%, such as about 1 wt% to about 10 wt%, such as about 1 wt% to about 5 wt%, based on the total weight of the monomers. The amount of the non-ionic surfactant x) can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0091] Examples of suitable nonionic surfactants include, but are not limited to, alkyl (e.g., monoalkyl, dialkyl, trialkyl) phenol ethoxylates, polysiloxane polyalkylene oxide copolymers, primary alcohol ethoxylates, fatty alcohol ethoxylates, fatty acid ethoxylates, alkanolamide ethoxylates, fatty amine ethoxylates, ethylene oxide-propylene oxide (EO-PO) block copolymers and alkylpolyglucosides, and mixtures thereof.

[0092] Specific examples of suitable nonionic surfactants include, but are not limited to, tert-octylphenoxyethylpoly-ethoxyethanol, dodecyloxypolyethoxyethanol, nonylphenoxyethyl-polyethoxyethanol, polyethylene glycol 2000 monooleate, ethoxylated castor oil, fluorinated alkyl esters and alkoxylates, polyoxyethylene sorbitan monolaurate, sucrose monococoate, di(2-butyl)phenoxypolyethoxyethanol, hydroxyethylcellulosepolybutyl acrylate graft copolymer, dimethyl silicone polyalkyleneoxide graft copolymer, poly(ethylene oxide)poly(butyl acrylate) block copolymer, block copolymers of propylene oxide and ethylene oxide, 2,4,7,9-tetramethyl-S-decyne-4,7-diol ethoxylated with 30 moles of ethylene oxide, N-polyoxyethylene lauramide, N-lauryl-N-polyoxyethylene amine, polyethylene glycol dodecyl thioether and mixtures thereof.

[0093] In an embodiment, the non-ionic surfactant comprises at least one of a linear fatty alcohol ethoxylate, a branched fatty alcohol ethoxylate, an ethoxylated monoalkyl phenol, an ethoxylated dialkyl phenol and an ethoxylated trialkyl phenol.

[0094] Polymerization Process Conditions

[0095] Any suitable chain transfer agent may be used in the polymerization of the first and second polymers of the multi-stage emulsion polymer particles. Non-limiting examples of such chain transfer agents include isooctyl 3-mercaptopropionate (IOMP), dodecyl mercaptan (DDM), n-butyl mercaptan, tert-dodecyl mercaptan, 2-ethylhexyl mercaptan, methyl mercaptan, carbon tetrachloride, carbon tetrabromide, dibenzoyl peroxide, dithioesters, trithiocarbonates, dithiocarbamates, xanthates, 1,8-dimercapto-3,6-dioxaoctane (DMDO), pentaerythritol tetrakis(2-mercaptoacetate), and the like. The amount of the chain transfer agent may be, for example, from about 0.01 wt% to about 5 wt%, or from about 0.05 wt% to about 4.5 wt%, or from about 0.1 wt% to about 4 wt%, or from about 0.2 wt% to about 3.5 wt%, or from about 0.3 wt% to about 3 wt%, or from about 0.35 wt% to about 2.5 wt%, or from about 0.4 wt% to about 2 wt%, or from about 0.45 wt% to about 1.75 wt%, or from about 0.5 wt% to about 1.5 wt%, or from about 0.5 wt% to about 1 wt%, or from about 0.5 wt% to about 0.75 wt%, and the like, based on the total amount of monomer. The amount of chain transfer agent can be equal to any integer value(s) within this range, including the end-points of these ranges. The type and amountof chain transfer agent may be the same or different in the various stages of the multistage polymerization.

[0096] The free radical initiators suitable for the polymerization of the monomers used to prepare the multi-stage emulsion polymer particles as described herein may be any water soluble initiator suitable for aqueous emulsion polymerization. Examples of free radical initiators suitable for the preparation of any of the shell layers of the multi-stage emulsion polymer particles of the present application include hydrogen peroxide, tert-butyl peroxide, alkali metal persulfates such as sodium, potassium and lithium persulfate, ammonium persulfate, and mixtures of such initiators with a reducing agent. The amount of initiator may be, for example, from about 0.01 to about 5 percent by weight (wt%), or from about 0.05 wt% to about 2.5 wt%, or from about 0.1 wt% to about 2 wt%, or from about 0.5 wt% to about 1.5 wt%, or about 0.025 wt%, or about 0.075 wt%, or about 0.125 wt%, or about 0.15 wt%, or about 0.175 wt%, or about 0.15 wt%, or about 0.3 wt%, or about 0.7 wt%, or about 1.25 wt%, or about 1.75 wt%, or about 2.25 wt%, or about 2.75 wt%, and the like, based on the total amount of monomer. The amount of initiator can be equal to any integer value(s) within this range, including the end-points of these ranges. The type and amount of initiator may be the same or different in the various stages of the multi-stage polymerization.

[0097] In some embodiments, a redox polymerization initiator system may be used. In a redox free radical initiation system, a reducing agent may be used in conjunction with an oxidant.

[0098] Reducing agents suitable for the aqueous emulsion polymerization include sulfites (e.g., alkali metal metabisulfite, hydrosulfite, and hyposulfite). In some embodiments,sugars (such as ascorbic acid and isoascorbic acid or an alkali metal (iso)ascorbate salt) might also be a suitable reducing agent for the aqueous emulsion polymerization. In a redox system, the amount of reducing agent may be, for example, from about 0.01 wt% to about 5 wt%, or from about 0.05 wt% to about 2.5 wt%, or from about 0.1 wt% to about 2 wt%, or from about 0.5 wt% to about 1.5 wt%, or about 0.025 wt%, or about 0.075 wt%, or about 0.125 wt%, or about 0.15 wt%, or about 0.175 wt%, or about 0.15 wt%, or about 0.3 wt%, or about 0.7 wt%, or about 1.25 wt%, or about 1.75 wt%, or about 2.25 wt%, or about 2.75 wt%, and the like, based on the total amount of monomer. The amount of the redox polymerization initiator system can be equal to any integer value(s) within this range, including the end-points of these ranges. The type and amount of the redox polymerization initiator system may be the same or different in the various stages of the multi-stage polymerization.

[0099] Oxidizing agents include, for example, for example, hydrogen peroxide and ammonium or alkali metal persulfates, perborates, peracetates, peroxides, and percarbonates and a water-insoluble oxidizing agent such as, for example, benzoyl peroxide, lauryl peroxide, t-butyl peroxide, t-butyl hydroperoxide, 2,2'-azobisisobutyronitrile, t-amyl hydroperoxide, t-butyl peroxyneodecanoate, and t-butyl peroxypivalate. The amount of oxidizing agent may be, for example, from about 0.01 wt% to about 5 wt%, or from about 0.05 wt% to about 2.5 wt%, or from about 0.1 wt% to about 2 wt%, or from about 0.5 wt% to about 1.5 wt%, or about 0.025 wt%, or about 0.075 wt%, or about 0.125 wt%, or about 0.15 wt%, or about 0.175 wt%, or about 0.15 wt%, or about 0.3 wt%, or about 0.7 wt%, or about 1.25 wt%, or about 1.75 wt%, or about 2.25 wt%, or about 2.75 wt%, and the like based on the total amount of monomer. The amount of theoxidizing agent can be equal to any integer value(s) within this range, including the endpoints of these ranges. The type and amount of the oxidizing agent may be the same or different in the various stages of the multi-stage polymerization.

[0100] The free radical polymerization temperature typically is in the range of about 50°C to about 110°C, or in the range of about 50°C to about 100°C, or in the range of about 20°C to about 90°C, or in the range of about 25°C to about 85°C, or in the range of about 30°C to about 80°C, or in the range of about 40°C to about 70°C, or about 12°C, or about 23°C, or about 34°C, or about 45°C, or about 56°C, or about 67°C, or about 78°C, or about 81°C, or about 92°C, and the like. In the case of the persulfate systems, the temperature may be in the range of about 60°C to about 100°C, or in the range of about 65°C to about 90°C, or in the range of about 70°C to about 80°C, or about 62°C, or about 64°C, or about 66°C, or about 68°C, or about 72°C, or about 74°C, or about 75°C, or about 77°C, or about 79°C, or about 81 °C, or about 85°C, or about 88°C, or about 92°C, or about 95°C, or about 98°C, and the like. In the redox system, the temperature may be in the range of about 30°C to about 100°C, or in the range of about 30°C to about 90°C, or in the range of about 30°C to about 80°C, or in the range of about 30°C to about 70°C, or in the range of about 30°C to about 60°C, or in the range of about 30° C to about 45° C, or in the range of about 35°C or about 40°C, or about 45°C, or about 50°C, or about 55°C, or about 60°C, or about 65°C, or about 70°C, or about 75°C, or about 80°C, or about 85°C, or about 90°C, and the like. The polymerization temperature can be equal to any integer value(s) within this range, including the end-points of these ranges. The temperature may be the same or different in the various stages of the multi-stage polymerization.

[0101] The pH of the polymerization process ranges from about 2 to about 9, or from about 3 to about 6, or from about 4.5 to about 8.5, or from about 4.75 to about 8, or from about 5 to about 7.75, or from about 5.25 to about 7.5, or from about 5.5 to about 7, and the like. The pH can be equal to any integer value(s) within this range, including the endpoints of these ranges. The pH may be the same or different in the various stages of the multi-stage polymerization.

[0102] Additives

[0103] The adhesive coating composition may further include at least one additive. Nonlimiting examples of suitable additives are those that are typically included in coating compositions including, for example, ammonium hydroxide, alkali metal hydroxides, or other bases to neutralize latex, leveling agents, emulsifiers, rheology control additives, additional polymers, dispersants or surfactants, defoamers, thickeners, stabilizers, viscosity stabilizers, biocides, solvents, rheology modifiers, wetting or spreading agents, conductive additives, thermal insulating fillers, adhesion promoters, antiblocking agents, anti-cratering agents or anti-crawling agents, anti-static agents, flame retardants, chelating agents, cross-linking agents, flattening agents, insecticides, lubricants, oils, waxes, or inorganic particles such as ceramic particles.

[0104] According to some embodiments, the aqueous coating composition may further comprise a rheology modifier. Nonlimiting examples are carboxymethyl cellulose (CMC), carrageenan, hydroxyethylcellulose (HEC), hydrophobically modified HEC (HMHEC); hydrophobically modified alkali-soluble emulsions (HASEs); and nonionic synthetic associative thickeners (NSATs), hydrophobically modified alkali swellable emulsions (HASE), hydrophobically modified ethoxylated urethane resins (HEUR). If present, theaqueous coating composition may comprise from 0.01 to 10 wt% of a rheology modifier, based on a total dry weight (i.e., exclusive of water) of the aqueous coating composition. In certain embodiments, carboxymethyl cellulose (CMC) may act as a binder.

[0105] According to some embodiments, the aqueous coating composition may further comprise a wetting agent. Non-limiting examples include silicone surfactants such as HYDROPALAT® WE 3220, nonionic surfactants such as tertoctylphenoxyethylpolyethoxyethanol, dodecyloxypolyethoxyethanol, tridecyloxypolyethoxyethanol, nonylphenoxyethyl-polyethoxyethanol, polyethylene glycol 2000 monooleate, ethoxylated castor oil, fluorinated alkyl esters and alkoxylates, polyoxyethylene sorbitan monolaurate, sucrose monococoate, di(2-butyl)phenoxypolyethoxyethanol, hydroxyethylcellulosepolybutyl acrylate graft copolymer, dimethyl silicone polyalkylene oxide graft copolymer, polyethylene oxide)poly(butyl acrylate) block copolymer, block copolymers of propylene oxide and ethylene oxide, 2,4,7,9-tetramethyl-5-decyne-4,7-diol ethoxylated with 30 moles of ethylene oxide, N-polyoxyethylenelauramide, N lauryl-N-polyoxyethyleneamine and polyethylene glycol dodecyl thioether. Aso suitable are ionic (anionic or cationic) surfactants such as sodium lauryl sulfate, sodium lauryl ether sulfate, sodium dodecylbenzenesulfonate, potassium stearate, sodium dioctyl sulfosuccinate, sodium dodecyldiphenyloxide disulfonate, nonylphenoxyethylpolyethoxyethyl sulfate ammonium salt, sodium styrene sulfonate, sodium dodecyl allyl sulfosuccinate, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, mixtures of fatty acids (e.g., linseed oil fatty acid), sodium or ammonium salts of phosphate esters of ethoxylated nonylphenol, sodium octoxynol-3-sulfonate, sodium cocoylsarcocinate, sodium l-alkoxy-2-hydroxypropyl sulfonate, sodium a-olefin (C 14-C I6) sulfonate, sulfatesof hydroxyalkanols, tetrasodium N-( 1,2-dicarboxy ethyl )-N-octadecylsulfosuccinamate, disodium N-octadecylsulfosuccinamate, disodium alkylamido polyethoxy sulfosuccinate, di sodium ethoxylated nonylphenol half ester of sulfosuccinic acid and the sodium salt of tertoctylphenoxyethoxypolyethoxyethylsulfate, or combinations thereof.

[0106] If present, the coating composition may comprise from about 0.01 wt% to about 5 wt% of a wetting agent (surfactant) based on the total dry weight (i.e. exclusive of water) of the coating composition.

[0107] Secondary Battery

[0108] A secondary battery incorporating the adhesive layer coated separator described herein can be any secondary battery know in the art, and such a secondary battery can be fabricated by any suitable method known in the art. For example, the secondary battery can be any device that includes a separator interposed between a cathode and an anode, and may include an electrolyte disposed therebetween. Such a secondary battery can be manufactured by assembling an electrode structure having an anode and a cathode with a separator therebetween. An electrolyte solution may be injected into the electrode assembly. In an embodiment herein, the secondary battery may be a lithium secondary battery.

[0109] The electrodes may include an electrode active material bonded to an electrode current collector. The cathode active material may be any commonly used cathode material, non-limiting examples of which include lithium manganese oxides, lithium cobalt oxides, lithium nickel oxides, lithium iron oxides, and lithium composite oxides thereof. The anode active material may be any commonly used anode material, non-limiting examples of which include lithium, lithium alloys, and lithium intercalation materials suchas carbon, petroleum coke, activated carbon, graphite and other carbonaceous materials. The cathode current collector material can include any suitable material, including but not limited to aluminum foils, nickel foils, and combinations thereof. The anode current collector material can include any suitable material, including but not limited to copper foils, gold foils, nickel foils, copper alloy foils and combinations thereof. The electrolyte solution may be a non-aqueous electrolyte solution that includes an organic solvent and an electrolyte salt. Preferably, the electrolyte salt may be a lithium salt that is conventionally used in a lithium secondary battery, including but not limited to Li salts having any one of the anions selected from F-, Cl-, Br, I-, NO3“, N(CN)2“, BF4-, ClO4-, ASF6“, PF6-, (CF3)2PF4-, (CF3)3PF3-, (CF3)4PF2-, (CF3)5PF- (CF3)6P- CF3SO3-, CF3CF2SO3-, (CF3SO2)2N-, (FSO2)2N- CF3CF2(CF3)2CO- (CF3SO2)2CH- (SF5)3C-, (CF3SO2)3C-, CF3(CF2)7SO3-, CF3CO2- CH3CO2-, SCN, (CF3CF2SO2)2N-, and combinations thereof. The electrolyte solution may also contain an organic solvent that is conventionally used in such electrolyte solutions, including but not limited to an ether, an ester, an amide, a linear carbonate, a cyclic carbonate, and combinations thereof.

[0110] Coating process

[0111] A process for producing a coated separator for a secondary battery includes applying the adhesive coating composition to at least one surface of the substrate, to form a coating layer on the substrate.

[0112] Non-limiting examples of coating methods are wire bar coating, gravure roll coating, slit coating, anilox roll coating, slot-die coating and spraying. Also suitable are a die coating method, a dip coating method, a roll coating method, a doctor coating method,a knife coating method, a spray coating method, a gravure coating method, a screenprinting method, an electrostatic coating method, and the like.

[0113] Coated separator

[0114] A coated separator for a secondary battery may include a porous or microporous substrate and a coating layer formed from the adhesive composition described herein on at least one surface of the substrate. The coating layer thickness on each surface of the substrate may be less than about 4 pm, or less than about 3 pm, or less than about 2 pm, or less than about 1.5 pm, or less than about 1 pm, or less than about 0.5 pm on each side, and may be greater than about 0 pm, or greater than about 0.001 pm, or greater than about 0.01 pm, or greater than about 0.1 pm, or greater than about 0.25 pm, or greater than about 0.5 pm,, and the like. The coating layer thickness may be from about 0.5 pm to about 4 pm, from about 1 pm to about 4 pm, from about 1.5 pm to about 4 pm, from about 2 pm to about 4 pm, and the like. The coating layer thickness can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0115] The adhesive composition may be applied to a surface of the separator in a patterned or a non-patterned layer, and if patterned, can be applied in any suitable pattern. The adhesive composition may be applied on an entire surface of the separator or may be applied to a portion of the surface of the separator. When the adhesive layer partially covers the surface of the separator, the coverage of the adhesive layer on the separator from about 1% to about 99%, or from about 5% to about 90%, or from about 10% to about 85%, or from about 15% to about 80%, and the like. The coverage of theadhesive layer on the separator can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0116] Porous or microporous substrate

[0117] The porous or microporous substrate may comprise olefinic polymers, such as polyethylene, polypropylene, copolymers of propylene and ethylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, and combinations thereof.

[0118] The porous or microporous substrate may have a thickness of from about 3 pm to about 50 pm, or from about 10 pm to about 45 pm, or from about 15 pm to about 40 pm, or from about 20 pm to about 35 pm, or about 3.5 pm, or about 5 pm, or about 7 pm, or about 9 pm, or about 12.5 pm, or about 17.5 pm, or about 22.5 pm, or about 27.5 pm, or about 32.5 pm, or about 37.5 pm, or about 42.5 pm, or about 47.5 pm, and the like. The thickness of the porous or microporous substrate can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0119] The porous or microporous substrate may have a pore size from about 1 nm to about 200 nm, or from about 5 nm to about 150 nm, or from about 10 nm to about 100 nm, or from about 15 nm to about 50 nm, or from about 20 nm to about 40 nm, or from about 2 nm, or about 4 nm, or about 6 nm, or about 8 nm, or about 12 nm, or about 14 nm, or about 16 nm, or about 18 nm, or about 25 nm, or about 30 nm, or about 35 nm, or about 45 nm, or about 55 nm, or about 60 nm, or about 65 nm, or about 70 nm, or about 75 nm, or about 80 nm, or about 85 nm, or about 90 nm, or about 95 nm, or about 125 nm, or about 175 nm, and the like. The pore size of the porous or microporous substratecan be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0120] The porous or microporous substrate may have a porosity from about 10% to about 95%, or from about 15% to about 90%, or from about 20% to about 85%, or from about 30% to about 80%, or from about 35% to about 75%, or from about 40% to about 80%, or from about 50% to about 75%, or about 12%, or about 14%, or about 16%, or about 18%, or about 22%, or about 24%, or about 25%, or about 27%, or about 29%, or about 31%, or about 33%, or about 35%, or about 37%, or about 39%, or about 45%, or about 55%, or about 65%, and the like. The porosity of the porous or microporous substrate can be equal to any integer value(s) within any of these ranges, including the end-points of these ranges.

[0121] An embodiment is directed to a composition for a non-aqueous secondary battery adhesive layer, the composition comprising a binder and a plurality of multistage polymeric particles, wherein each of the plurality of multistage polymeric particles comprises a first formed hard stage comprising a first polymer and a second formed soft stage comprising a second polymer, wherein the glass transition temperature of the first polymer (Tgn) is at least 10°C greater, preferably at least 20°C greater, than the glass transition temperature of the second polymer (Tgs), wherein each of the plurality of polymeric particles comprises less than 10% by mass of an acid-functionalized monomer, wherein a percentage distribution of acid-functionalized monomer in the second polymer (PDFM2) is greater than 50%, preferably greater than 60%, and the PDFM2 is calculated from Equation 1:PDFM2 = percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer / (percentage of acid-functionalized monomer based on the total amount of monomers in the first polymer + percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer)... Equation 1,and wherein the binder is a latex polymer, a water-soluble polymer, or a combination thereof.

[0122] Another embodiment is directed to a method for forming a composition for a nonaqueous secondary battery adhesive layer, wherein the method comprises the steps of:

[0123] feeding a first monomer mixture to a reactor vessel; initiating a free radical polymerization of the first monomer mixture to form a first stage of the polymeric particles, the first-formed stage comprising a first polymer comprising the first monomer mixture as polymerized units; feeding a second monomer mixture to the reactor vessel; and polymerizing the second monomer mixture in the presence of the first-formed stage to form a second stage of the polymeric particles, the second stage comprising a second polymer comprising the second monomer mixture as polymerized units;

[0124] wherein: the composition comprises a binder and a plurality of multistage polymeric particles, wherein each of the plurality of multistage polymeric particles comprises the first polymer and the second polymer, wherein the glass transition temperature of the first polymer (Tgn), calculated using the Fox equation, is at least 10°C greater, preferably at least 20°C greater, than the glass transition temperature of the second polymer (Tgs), calculated using the Fox equation, wherein each of the plurality ofpolymeric particles comprises less than 10% by mass of an acid-functionalized monomer, wherein a percentage distribution of acid-functionalized monomer in the second polymer (PDFM2) is greater than 50%, preferably greater than 55%, and the PDFM2 is calculated from Equation 1:PDFM = percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer / (percentage of acid-functionalized monomer based on the total amount of monomers in the first polymer + percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer)... Equation 1,

[0125] and wherein the binder is a water-soluble polymer, a water-insoluble polymer, or a combination thereof.

[0126] Another embodiment is directed to a non-aqueous adhesive layer for secondary battery comprising the composition for a non-aqueous secondary battery adhesive layer described herein.

[0127] Another embodiment is directed to a separator comprising a substrate and the nonaqueous adhesive layer for secondary battery comprising the composition for a nonaqueous secondary battery adhesive layer described herein, wherein the non-aqueous adhesive layer is deposited on at least one surface of the substrate.

[0128] Another embodiment is directed to a second battery comprising a positive electrode, a negative electrode, and a separator a separator comprising a substrate and the non-aqueous adhesive layer for secondary battery comprising the composition for a non-aqueous secondary battery adhesive layer described herein.

[0129] In any of the embodiments herein, the PDFM2 is from about 55% to about 99.99%, preferably from about 65% to about 95%.

[0130] In any of the embodiments herein, the first polymer comprises, as polymerized units based on a dry weight of the first polymer: i) about 70 wt% to about 99.98 wt% of one or more free radical polymerizable ethylenically unsaturated monomers not containing acid functional groups; ii) about 0.01 wt% to about 10 wt% of one or more acid containing functional monomers; ill) about 0.0 wt% to about 10 wt% of one or more free radical polymerizable monomers having a crosslinkable functionality; iv) about 0.001 wt% to about 5 wt% of one or more anionic surfactants; and v) about 0 wt% to about 5 wt% of one or more non-ionic surfactants, wherein the glass transition temperature of the first polymer, calculated using the Fox equation, is between 30°C and 80°C.

[0131] In any of the embodiments herein, the second polymer comprises, as polymerized units based on a dry weight of the second polymer: vi) about 65 wt% to about 99.98 wt% of one or more free radical polymerizable ethylenically unsaturated monomers; vii) about 0.01 wt% to about 20 wt% of one or acid containing monomers; viii) about 0.0 wt% to about 10 wt% of one or more free radical polymerizable monomers having a crosslinkable functionality; ix) about 0.001 wt% to about 2.5 wt% of one or more anionic surfactants; and x) about 0.0 wt% to about 2.5 wt% of one or more non-ionic surfactants, wherein the glass transition temperature of the second polymer, calculated using the Fox equation, is between -20°C and 20°C.

[0132] In any of the embodiments herein, a ratio of the first polymer to the second polymer ranges from about 90:10 to about 10:90, preferably from about 90:10 to about 50:0, more preferably from about 80:20 to about 55:45.

[0133] In any of the embodiments herein, the i) one or more free radical polymerizable ethylenically unsaturated monomers in the first polymer are selected from the group consisting of one or more alkyl(meth)acrylates, styrene, and mixtures thereof.

[0134] In any of the embodiments herein, the ii) one or more acid monomers in the first polymer are selected from the group consisting of acrylic acid, methacrylic acid, or a mixture thereof.

[0135] In any of the embodiments herein, the iii) free radical polymerizable monomer having a crosslinkable functionality in the first polymer are selected from the group consisting of diacetone acrylamide, acetoacetoxyalkyl(meth)acrylate, 2-acetoacetoxyethyl (meth)acrylate, 3-acetoacetoxypropyl (meth)acrylate, 4-acetoacetoxybutyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, 3-cyanoacetoxypropyl (meth)acrylate, 4-cyanoacetoxybutyl (meth)acrylate, N-(2-acetoacetoxyethyl) (meth)acrylamide, allyl acetoacetate, 2,3-di(acetoacetoxy)propyl (meth)acrylate, vinyl acetoacetate, and combinations thereof.

[0136] In any of the embodiments herein, the anionic surfactant iv) is selected from the group consisting of alkylbenzenesulfonic acids, alkaline earth metal alkylbenzenesulfonates, sulfonated fatty acids, sulfonated olefins, sulfonated diphenyl ethers, sulfosuccinates, fatty alcohol sulfates, alkylphenol sulfates, alkyl polyglycol ether sulfates, fatty alcohol ether sulfates, fatty alcohol phosphates, alkylphenol phosphates, alkyl polyglycol ether phosphates, alkyl polyalkylene oxide phosphates, fatty alcohol ether phosphates, and mixtures thereof.

[0137] In any of the embodiments herein, the non-ionic surfactant v) is selected from the group consisting of alkyl phenol ethoxylates, polysiloxane polyalkylene oxide copolymers,primary alcohol ethoxylates, fatty alcohol ethoxylates, fatty acid ethoxylates, alkanolamide ethoxylates, fatty amine ethoxylates, ethylene oxide-propylene oxide (EO-PO) block copolymers, alkylpolyglucosides, and mixtures thereof.

[0138] In any of the embodiments herein, the vi) one or more free radical polymerizable ethylenically unsaturated monomers in the second polymer are selected from the group consisting of one or more alkyl(meth)acrylates, styrene, and mixtures thereof.

[0139] In any of the embodiments herein, the vii) one or more acid monomers in the second polymer are selected from the group consisting of acrylic acid, methacrylic acid, or a mixture thereof.

[0140] In any of the embodiments herein, the viii) free radical polymerizable monomer having a crosslinkable functionality in the second polymer are selected from the group consisting of diacetone acrylamide, acetoacetoxyalkyl(meth)acrylate, 2-acetoacetoxyethyl (meth)acrylate, 3-acetoacetoxypropyl (meth)acrylate, 4-acetoacetoxybutyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, 3-cyanoacetoxypropyl (meth)acrylate, 4-cyanoacetoxybutyl (meth)acrylate, N-(2-acetoacetoxyethyl) (meth)acrylamide, allyl acetoacetate, 2,3-di(acetoacetoxy)propyl (meth)acrylate, vinyl acetoacetate, and combinations thereof.

[0141] In any of the embodiments herein, the anionic surfactant ix) is selected from the group consisting of alkylbenzenesulfonic acids, alkaline earth metal alkylbenzenesulfonates, sulfonated fatty acids, sulfonated olefins, sulfonated diphenyl ethers, sulfosuccinates, fatty alcohol sulfates, alkylphenol sulfates, alkyl polyglycol ether sulfates, fatty alcohol ether sulfates, fatty alcohol phosphates, alkylphenol phosphates,alkyl polyglycol ether phosphates, alkyl polyalkylene oxide phosphates, fatty alcohol ether phosphates, and mixtures thereof.

[0142] In any of the embodiments herein, the non-ionic surfactant x) is selected from the group consisting of alkyl phenol ethoxylates, polysiloxane polyalkylene oxide copolymers, primary alcohol ethoxylates, fatty alcohol ethoxylates, fatty acid ethoxylates, alkanolamide ethoxylates, fatty amine ethoxylates, ethylene oxide-propylene oxide (EO-PO) block copolymers, alkylpolyglucosides, and mixtures thereof.

[0143] In any of the embodiments herein, the binder is a polymer latex, wherein the polymer latex comprises, as polymerized monomer, at least one ethylenically unsaturated monomer. Preferably, the ethylenically unsaturated monomer comprises at least one of vinyl aromatic monomers, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethyl hexyl acrylate, (meth)acrylic acid, or a combination thereof, wherein the the glass transition temperature of the polymer latex, calculated using the Fox equation, is between -60°C to 20°C.

[0144] In any of the embodiments herein, the non-aqueous adhesive layer further comprises an additive selected from neutralizers, leveling agents, emulsifiers, rheology control additives, additional polymers, dispersants or surfactants, defoamers, thickeners, stabilizers, viscosity stabilizers, biocides, solvents, rheology modifiers, wetting or spreading agents, conductive additives, thermal insulating fillers, adhesion promoters, antiblocking agents, anti-cratering agents or anti-crawling agents, anti-static agents, flame retardants, chelating agents, cross-linking agents, flattening agents, insecticides, lubricants, oils, waxes, or inorganic particles such as ceramic particles.

[0145] In any of the embodiments herein, the non-aqueous adhesive layer is deposited on at least one surface of the substrate.

[0146] In any of the embodiments herein, the non-aqueous adhesive layer is deposited on two opposite surfaces of the substrate.

[0147] In any of the embodiments herein, the substrate is a coated porous membrane or an uncoated porous membrane.

[0148] In any of the embodiments herein, the substrate is a coated porous membrane, and wherein a surface of the porous membrane is coated with a ceramic layer.

[0149] In any of the embodiments herein, a thickness of the porous substrate is from about 3 pm to about 50 pm.

[0150] In any of the embodiments herein, as thickness of the non-aqueous adhesive layer is from about 0.1 pm to about 5 pm.

[0151] In another embodiment, the Gurley value of the separator is increased by less than 30% relative to the Gurley value of the base substrate without the non-aqueous adhesive layer, the percentage increase being determined by the formula:(Gurley value of the adhesive layer-coated base substrate - Gurley value of the uncoated base substrate) - Gurley value of the uncoated base substrate).

[0152] Within this specification, embodiments have been described in a way which enables a clear and concise specification to be written, but it is intended and will be appreciated that embodiments may be variously combined or separated without departing from the invention. For example, it will be appreciated that all preferred features described herein are applicable to all aspects of the invention described herein.

[0153] In some embodiments, the invention herein can be construed as excluding any element or process step that does not materially affect the basic and novel characteristics of the compositions, prepared therefrom and methods for making and using such compositions described herein. Additionally, in some embodiments, the invention can be construed as excluding any element or process step not specified herein. Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.

[0154] EXAMPLES

[0155] The principles of the present invention, as well as certain exemplary features and embodiments thereof, will now be described by reference to the following non-limiting examples.

[0156] Experimental Details

[0157] Preparation Example 1

[0158] Multistage polymeric particles were prepared by emulsion polymerization. In Preparation Example 1, 662 parts of deionized water was charged into a reactor equipped with a stirrer, reflux condensers, thermocouples, and stainless-steel feed lines. Separately, a pre-emulsified Monomer Mixture 1 (“MMT; hard stage) was prepared from 153 parts of water, 4.5 parts of Aerosol® A102, 8.3 parts of a Disponil® A3065, 417 parts of styrene, 95 parts of 2-ethylhexyl acrylate (2-EHA), 7 parts of acrylamide, 22 parts of diacetone acrylamide (DAAM), and 4 parts of acrylic acid. The calculated Fox Tg of the first polymerized hard stage polymer based on MM1 is 52 °C.

[0159] After the reactor was heated to 800°C, 2 wt% of MM1 was added into the reactor, followed by adding 0.6 parts of ammonium persulfate in 2 parts of water. After 10 mins, the remaining 98% of MM1 was fed continuously to the reactor over 170 minutes. In the meantime, a delayed oxidizer solution consisting of 3.1 parts of ammonium persulfate in 109 parts of water was fed into the reactor over 250 mins. During the feeding of MM1 in the reactor, a pre-emulsified Monomer Mixture 2 (“MM2”; soft stage) was prepared from 66 parts of water, 1.9 parts of Aerosol® A102, 3.6 parts of Disponil® A3065, 105 parts of styrene, 100 parts of 2-ethylhexyl acrylate (2-EHA), 3 parts of acrylamide, 9 parts of diacetone acrylamide (DAAM), and 16 parts of acrylic acid. The calculated Fox Tg of the second polymerized soft stage polymer based on MM2 is 1 °C.

[0160] At the end of MM1 feed, the reaction was held for 10 mins, followed by MM2 into the same reactor over 70 mins. At the end of MM2 feed, a solution of 1.6 parts of tertiary- butyl hydroperoxide (t-BHP, 70% active) and 2.1 parts of BRUGGOLITE@ FF6 M were fed into the reactor over 60 mins to minimize the concentration of any residual monomers At the end of reaction, a solution of 16 parts of adipic dihydrazide and 72 parts of water was added into the reaction mixture. The final pH of the latex was adjusted to 8-9 using ammonium hydroxide. The multistage polymeric particles of Preparation Example 1 has a solid content of 40%, with a hard / soft stage ratio of 70 / 30 and a total acrylic acid level in the hard and soft stages of 2.6 parts per hundreds of monomers (PHM).

[0161] The percentage distribution of acrylic acid in the second-formed soft stage (PDFMZ) is calculated from Equation 1:PDFM2 = percentage of acid-functionalized monomer based on the total amount of monomers in the second formed soft stage / (percentage of acid-functionalized monomerbased on the total amount of monomers in the first formed hard stage + percentage of acid-functionalized monomer based on the total amount of monomers in the second formed soft stage) Equation 1.

[0162] A PDFMS value greater than 50% is indicative of a higher acrylic acid concentration in the second-formed soft stage. PDFM2 value of the multistage polymer particles of Preparation Example 1 is 91%.

[0163] Preparation Examples 2-5 and Comparative Preparation Examples 1-3

[0164] Preparation Examples 2-5 and Comparative Preparation Examples 1-3 were carried out according to the process described in Example 1, with the exception that the hard / soft stage ratios, total acrylic acid levels, and the percentage of acrylic acid distribution in the second-formed soft stage for each of these examples were as shown in Table 1.

[0165] TABLE 1Particle size AcrylicAcrylicacidacid level Total level inStage inacrylic first- PDFM2 ratios second- acid formed (%) (hard / soft) formed(PHM) hardsoft stage stage(pm) (pm) (%)(%)ComparativePreparation 0.355 0.267 70 / 30 2.6 2.6 2.6 50 Example 1Preparation0.350 0.288 70 / 30 2.6 0.7 6.9 91 Example 1ComparativePreparation 0.528 0.335 70 / 30 3.5 3.5 3.5 50Example 2Preparation0.400 0.324 70 / 30 3.5 0.9 9.5 91 Example 2ComparativePreparation 0.322 0.244 80 / 20 2.6 2.6 2.6 50 Example 3Preparation0.362 0.301 80 / 20 2.6 0.9 9.5 91 Example 3Preparation0.324 0.271 80 / 20 2.6 1.5 6.8 82 Example 4Preparation0.324 0.262 80 / 20 2.6 2.0 4.9 71Example 5

[0166] As shown in Table 1, the PDF Z values are at 50% in Comparative Examples 1 -3, indicating equal distribution of the acrylic acid monomer is the first-formed hard and second-formed soft stages. In comparison, the PDFMZ values of Examples 1-5 is greater than 50% indicating a higher concentration of the acrylic acid monomers in the second- formed soft stage.

[0167] Preparation Example 6 - Preparation of Latex Binder

[0168] The latex binder was prepared by emulsion polymerization. Specifically, 713 parts of deionized water and 1.2 parts of Aerosol® MA-80I was charged into a reactor equipped with a stirrer, reflux condensers, thermocouples, and stainless-steel feed lines. Separately, a pre-emulsified monomer mixture (“MMB”) consisting of 186 parts of water, 2 parts of Rhodacal® DS 4, 667 parts of butyl acrylate, 68 parts of acrylamide, 41 parts of acrylonitrile, 32 parts of methacrylic acid, and 4 parts of allyl methacrylate was prepared. After the reactor was heated to 85°C, 2 wt% of MMB was added into the reactor, followed by addition of 3.4 parts of ammonium persulfate in 27 parts of water. After 10 mins, the remaining 98 wt% of MMB was fed continuously to the reactor over 210 minutes. At the end of monomer feed, a solution of 3.3 parts of tertiary-butyl hydroperoxide (t-BHP,70% active) and 2.5 parts of BRUGGOLITE@ FF6 M were fed into the reactor over 90 mins to minimize the residual monomer concentrations. The final pH of the latex was adjusted to 8-9 using ammonium hydroxide. The final latex has solids content of 40%, with volume average particle size of 600 nm and Brookfield viscosity below 500 centipoises.

[0169] Preparation of Adhesive Layer Coated Separators

[0170] Aqueous adhesive slurries was prepared by mixing 94.1 parts of the multi-stage polymeric particles prepared according to Preparation Examples 1-5 and Comparative Preparation Examples 1-3, respectively, 5.6 parts of the latex binder prepared according to Preparation Example 6, and 0.2 parts of Daicel 1220 carboxymethyl cellulose. Water was added to each respective slurry to adjust the total solids content of the slurry to 15%. Each adhesive slurry was then applied onto ceramic coated separator membranes (12 pm base polyethylene film with a 2 pm ceramic coating on each surface thereof) using a wire bar coater, followed by drying at 60°C for 5 mins to achieve an adhesive layer having a thickness of 1 to 2 pm.

[0171] Characterization of the Permeability of Adhesive Layer Coated Separators

[0172] Gurley value is a measure of the permeability of a separator and is calculated based on the time taken for 100 cubic centimeters of air to pass through one square inch of a given material, and this value is measured using a Gurley Standard Densometer411 ON manufactured by Thwing-Albert Instrument Company. The increase in Gurley value after coating (“Ginc”) with adhesive layer is calculated from Equation 2:Ginc (sec / 100 cc) = Gseparator (sec / 100 cc) - GBase (sec / 100 cc)Equation 2J 1In Equation 2, Gseparator is the Gurley value of the adhesive layer coated and Gsase is the Gurley value of the base separator For the examples described herein, the base separator is ceramic coated and has a Gsase value of 250 sec / 100cc.

[0173] Adhesion of Adhesive Layer Coated Separators Against Anodes

[0174] The adhesion of the adhesive layer coated separators was measured with respect to a graphite-containing anode deposited on a copper current collector. The adhesive layer coated separators were heat pressed against the anodes at a pressure of 1 MPa and a temperature of 80“C for 15 sec. After completion of the heat pressing process, the adhesion force between the adhesive layer coated separators and the anodes was characterized by measuring the 180° peel strength using a tensile / compression tester from Chem Instruments. The load cell was 25 lbs obtained from FUTEK Advanced Sensor Technology, Inc., and the peel speed was set. at 50 mm / min. The adhesion force was measured in triplicate, and the average value was reported. The adhesion of the base ceramic coated separator against the anode was undetectable under the same characterization conditions. The measured adhesion values are listed in Table 2. The adhesive composition of the adhesive layer coated separators of Examples 1-5 include the polymeric particles of Preparation Examples 1-5 respectively, and the adhesive compositions of the adhesive layer coated separators of Comparative Examples 1-3 include the polymeric particles of Comparative Preparation Examples 1-3 respectively. As shown in Table 2, all the adhesive layer coated separators of Examples 1-5 and Comparative Example 1-3 showed good adhesion (20-25 N / m) against anodes compared to the lack of adhesion observed for a base separator without the adhesive layer described herein.

[0175] TABLE 2Properties of the ad hesive layer coated separators Ginc (sec / 100 cc) Adhesion against anodes (N / m) Comparative Example 1 80 23Example 1 49 24Comparative Example 2 143 24Example 2 74 25Comparative Example 3 112 22Example 3 75 22Example 4 67 24Example 5 61 23

[0176] While strong bonding between adhesive-coated separators and electrodes improves battery performance, the adhesive layer can reduce separator permeability, which would be reflected as increasing Ginc values. Thus, an ideal solution would be an adhesive layer-coated separator that maintains good electrode adhesion while minimizing impact on permeability. Better permeability (i.e., lower Gurley value) correlates with more efficient ion transportation during the charge and discharge process in secondary batteries.

[0177] The results in Table 2 show the unexpectedly surprising effect of concentrating the acid monomers in the second formed soft stage polymer. The adhesive layer coated separators of Comparative Examples 1-3 all have significantly higher Gino values (80-143) than the Ginc values (49-75) of Examples 1-5. In Comparative Examples 1-3, the PDFM2 values are at 50% indicating equal distribution of the acrylic acid monomer is the first- formed hard and second-formed soft stages. In comparison, the PDFM2 values of Examples 1-5 is greater than 50% indicating a higher concentration of the acrylic acid monomers in the second-formed soft stage. These results show that both enhancedadhesion of the adhesive layer coated separators to the anodes and improved permeability can be achieved when the acid monomer concentration is higher in the second formed soft stage having a PDFM2 value of greater than 50%, preferably greater than 60%, as in the inventive examples described herein.

[0178] As various modifications could be made in the above methods and compositions and would be apparent to those skilled in the art without departing from the scope of the invention, the disclosures herein are intended to be interpreted as illustrative and not limiting. Any numbers expressing quantities of ingredients, constituents, reaction conditions, and so forth used in the specification are to be interpreted as encompassing the exact numerical values identified herein, as well as being modified in all instances by the term “about” used as a term of approximation, and intended to include minor variations in the literally stated values as understood in the art and subject to any standard deviations found in their respective measurement techniques. None of the features recited herein should be interpreted as invoking 35 U S C § 112, paragraph 6, unless the term “means” is explicitly used in reference to a function.

Claims

What is claimed is:

1. A composition for a non-aqueous secondary battery adhesive layer, the composition comprising a binder and a plurality of multistage polymeric particles, wherein each of the plurality of multistage polymeric particles comprises a first formed hard stage comprising a first polymer and a second formed soft stage comprising a second polymer,wherein the glass transition temperature of the first polymer (Tgn), calculated using the Fox equation, is at least 20°C greater than the glass transition temperature of the second polymer (Tgs), calculated using the Fox equationwherein each of the plurality of polymeric particles comprises less than 10% by mass of an acid-functionalized monomer,wherein a percentage distribution of acid-functionalized monomer in the second polymer (PDFM2) is greater than 50%, and the PDFM2 is calculated from Equation 1:PDFM = percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer I (percentage of acid-functionalized monomer based on the total amount ofmonomers in the first polymer + percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer).... Equation 1, and wherein the binder is a latex polymer, a water-soluble polymer, or a combination thereof.

2. The composition of claim 1, wherein the PDFM2 is from about 55% to about 99.99%.

3. The composition of claim 1 or 2, wherein the wherein a percentage distribution of acid-functionalized monomer in the second polymer PDFM2 is from about 65% to about 95%.

4. The composition of any one of claims 1 -3, wherein the first polymer comprises, as polymerized units based on a dry weight of the first polymer:i) about 70 wt% to about 99.98 wt% of one or more free radical polymerizable ethy len ically unsaturated monomers not containing acid functional groups;ii) about 0.01 wt% to about 10 wt% of one or more acid containing functional monomers; iii) about 0.0 wt% to about 10 wt% of one or more free radical polymerizable monomers having a crosslinkable functionality;iv) about 0.001 wt% to about 5 wt% of one or more anionic surfactants; andv) about 0 wt% to about 5 wt% of one or more non-ionic surfactants,wherein the Tgn, calculated using the Fox equation, is between 30°C to 80°C.

5. The composition of any one of claims 1 -4, wherein the second polymer comprises, as polymerized units based on a dry weight of the second polymer:vi) about 65 wt% to about 99.98 wt% of one or more free radical polymerizable ethylenically unsaturated monomers;vii) about 0.01 wt% to about 20 wt% of one or acid containing monomers;viii) about 0.0 wt% to about 10 wt% of one or more free radical polymerizable monomers having a crosslinkable functionality;ix) about 0.001 wt% to about 2.5 wt% of one or more anionic surfactants; andx) about 0.0 wt% to about 2.5 wt% of one or more non-ionic surfactants,wherein the Tgs, calculated using the Fox equation, is between -240°C to 20°C.

6. The composition of any one of claims 1-5, wherein a ratio of the first polymer to the second polymer ranges from about 90: 10 to about 10:90, preferably from about 90: 10 to about 50:50, more preferably from about 80:20 to about 55:45.

7. The composition of any one of claims 1-6, wherein the i) one or more free radical polymerizable ethylenically unsaturated monomers in the first polymer are selected from the group consisting of one or more alkyl(meth)acrylates, styrene, and mixtures thereof.

8. The composition of any one of claims 1-7, wherein the ii) one or more acid monomers in the first polymer are selected from the group consisting of acrylic acid, methacrylic acid, or a mixture thereof.

9. The composition of any one of claims 1-8, wherein the iii) free radical polymerizable monomer having a crosslinkable functionality in the first polymer are selected from the group consisting of diacetone acrylamide, acetoacetoxyalkyl(meth)acrylate, 2-acetoacetoxyethyl (meth)acrylate, 3-acetoacetoxypropyl (meth)acrylate, 4-acetoacetoxybutyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, 3-cyanoacetoxypropyl (meth)acrylate, 4-cyanoacetoxybutyl (meth)acrylate, N-(2-acetoacetoxyethyl) (meth)acrylamide, allyl acetoacetate, 2,3-di(acetoacetoxy)propyl (meth)acrylate, vinyl acetoacetate, and combinations thereof.

10. The composition of any one of claims 1-9, wherein the anionic surfactant iv) is selected from the group consisting of alkylbenzenesulfonic acids, alkaline earth metal alkylbenzenesulfonates, sulfonated fatty acids, sulfonated olefins, sulfonated diphenyl ethers, sulfosuccinates, fatty alcohol sulfates, alkylphenol sulfates, alkyl polyglycol ether sulfates, fatty alcohol ether sulfates, fatty alcohol phosphates, alkylphenol phosphates,alkyl polyglycol ether phosphates, alkyl polyalkylene oxide phosphates, fatty alcohol ether phosphates, and mixtures thereof.

11. The composition of any one of claims 1-10, wherein the non-ionic surfactant v) is selected from the group consisting of alkyl phenol ethoxylates, polysiloxane polyalkylene oxide copolymers, primary alcohol ethoxylates, fatty alcohol ethoxylates, fatty acid ethoxylates, alkanolamide ethoxylates, fatty amine ethoxylates, ethylene oxide-propylene oxide (EO-PO) block copolymers, alkylpolyglucosides, and mixtures thereof.

12. The composition of any one of claims 1-11, wherein the vi) one or more free radical polymerizable ethylenically unsaturated monomers in the second polymer are selected from the group consisting of one or more alkyl(meth)acrylates, styrene, and mixtures thereof.

13. The composition of any one of claims 1-13, wherein the vii) one or more acid monomers in the second polymer are selected from the group consisting of acrylic acid, methacrylic acid, or a mixture thereof.

14. The composition of any one of claims 1-13, wherein the viii) free radical polymerizable monomer having a crosslinkable functionality in the second polymer are selected from the group consisting of diacetone acrylamide, acetoacetoxyalkyl(meth)acrylate, 2-acetoacetoxyethyl (meth)acrylate, 3-acetoacetoxypropyl (meth)acrylate, 4-acetoacetoxybutyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, 3-cyanoacetoxypropyl (meth)acrylate, 4-cyanoacetoxybutyl (meth)acrylate, N-(2-acetoacetoxyethyl) (meth)acrylamide, allyl acetoacetate, 2,3-di(acetoacetoxy)propyl (meth)acrylate, vinyl acetoacetate, and combinations thereof.

15. The composition of any one of claims 1-14, wherein the anionic surfactant ix) is selected from the group consisting of alkylbenzenesulfonic acids, alkaline earth metal alkylbenzenesulfonates, sulfonated fatty acids, sulfonated olefins, sulfonated diphenyl ethers, sulfosuccinates, fatty alcohol sulfates, alkylphenol sulfates, alkyl polyglycol ether sulfates, fatty alcohol ether sulfates, fatty alcohol phosphates, alkylphenol phosphates, alkyl polyglycol ether phosphates, alkyl polyalkylene oxide phosphates, fatty alcohol ether phosphates, and mixtures thereof.

16. The composition of any one of claims 1-15, wherein the non-ionic surfactant x) is selected from the group consisting of alkyl phenol ethoxylates, polysiloxane polyalkylene oxide copolymers, primary alcohol ethoxylates, fatty alcohol ethoxylates, fatty acid ethoxylates, alkanolamide ethoxylates, fatty amine ethoxylates, ethylene oxide-propylene oxide (EO-PO) block copolymers, alkylpolyglucosides, and mixtures thereof.

17. The composition of any one of claims 1 -16, wherein the binder is a polymer latex, wherein the polymer latex comprises, as polymerized monomer, at least one ethylenically unsaturated monomer.

18. The polymer latex of claim 17, wherein the ethylenically unsaturated monomer comprises at least one of vinyl aromatic monomers, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethyl hexyl acrylate, (meth)acrylic acid, or a combination thereof, wherein the glass transition temperature of the polymer latex, calculated using the Fox equation, is between -60°C to 20°C.

19. A method for forming a composition fora non-aqueous secondary battery adhesive layer, wherein the method comprises the steps of:feeding a first monomer mixture to a reactor vessel;initiating a free radical polymerization of the first monomer mixture to form a first stage of the polymeric particles, the first-formed stage comprising a first polymer comprising the first monomer mixture as polymerized units;feeding a second monomer mixture to the reactor vessel;polymerizing the second monomer mixture in the presence of the first-formed stage to form a second stage of the polymeric particles, the second stage comprising a second polymer comprising the second monomer mixture as polymerized units;wherein:the composition comprises a binder and a plurality of multistage polymeric particles,wherein each of the plurality of multistage polymeric particles comprises the first polymer and the second polymer,wherein the glass transition temperature of the first polymer (Tgn), calculated using the Fox equation, is at least 20°C greater than the glass transition temperature of the second polymer (Tgs), calculated using the Fox equation,wherein each of the plurality of polymeric particles comprises less than 10% by mass of an acid-functionalized monomer,wherein a percentage distribution of acid-functionalized monomer in the second polymer (PDFM2) is greater than 50%, and the PDFM2 is calculated from Equation 1: PDFM = percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer I (percentage of acid-functionalized monomer based on the total amount ofmonomers in the first polymer + percentage of acid-functionalized monomer based on the total amount of monomers in the second polymer)... Equation 1, andwherein the binder is a water-soluble polymer, a water-insoluble polymer, or a combination thereof.

20. The method of claim 19, wherein the PDFM2 is from about 55% to about 99.99%.

21. The method of claim 19 or 20, wherein the wherein a percentage distribution of acid-functionalized monomer in the second polymer PDFM2 is from about 60% to about 95%.

22. The method of any one of claims 19-21, wherein the first polymer comprises, as polymerized units based on a dry weight of the first polymer:i) about 70 wt% to about 99.98 wt% of one or more free radical polymerizable ethylenically unsaturated monomers;ii) about 0.01 wt% to about 10 wt% of one or more acid containing functional monomers; iii) about 0.0 wt% to about 10 wt% of one or more free radical polymerizable monomers having crosslinkable functionality;iv) about 0.001 wt% to about 5 wt% of one or more anionic surfactants; andv) about 0.0 wt% to about 5 wt% of one or more non-ionic surfactants,wherein the Tgn, calculated using the Fox equation, is between 30°C to 80°C.

23. The method of any one of claims 19-22, wherein the second polymer comprises, as polymerized units based on a dry weight of the second polymer:vi) about 65 wt% to about 99.98 wt% of one or more free radical polymerizable ethylenically unsaturated monomers;vii) about 0.01 wt% to about 20 wt% of one or more acid containing monomers;viii) about 0.0 wt% to about 10 wt% of one or more free radical polymerizable monomers having a crosslinkable functionality;ix) about 0.001 wt% to about 2.5 wt% of one or more anionic surfactants; andx) about 0.0 wt% to about 2.5 wt% of one or more non-ionic surfactants,wherein the Tgs, calculated using the Fox equation, is between -20°C to 20°C.

24. The method of any one of claims 19-23, wherein a ratio of the first polymer to the second polymer ranges from about 90:10 to about 10:90, preferably from about 90:10 to about 50:50, more preferably from about 80:20 to about 55:45.

25. The method of any one of claims 19-24, wherein the i) one or more free radical polymerizable ethylenically unsaturated monomers in the first polymer are selected from the group consisting of one or more alkyl(meth)acrylates, styrene, and mixtures thereof.

26. The composition of any one of claims 19-25, wherein the ii) one or more acid monomers in the first polymer are selected from the group consisting of acrylic acid, methacrylic acid, or a mixture thereof.

27. The composition of any one of claims 19-26, wherein the iii) free radical polymerizable monomer having a crosslinkable functionality in the first polymer are selected from the group consisting of diacetone acrylamide, acetoacetoxyalkyl(meth)acrylate, 2-acetoacetoxyethyl (meth)acrylate, 3-acetoacetoxypropyl (meth)acrylate, 4-acetoacetoxybutyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, 3-cyanoacetoxypropyl (meth)acrylate, 4-cyanoacetoxybutyl (meth)acrylate, N-(2-acetoacetoxyethyl) (meth)acrylamide, allyl acetoacetate, 2,3-di(acetoacetoxy)propyl (meth)acrylate, vinyl acetoacetate, and combinations thereof.

28. The composition of any one of claims 19-27, wherein the anionic surfactant iv) is selected from the group consisting of alkylbenzenesulfonic acids, alkaline earth metal alkylbenzenesulfonates, sulfonated fatty acids, sulfonated olefins, sulfonated diphenyl ethers, sulfosuccinates, fatty alcohol sulfates, alkylphenol sulfates, alkyl polyglycol ether sulfates, fatty alcohol ether sulfates, fatty alcohol phosphates, alkylphenol phosphates, alkyl polyglycol ether phosphates, alkyl polyalkylene oxide phosphates, fatty alcohol ether phosphates, and mixtures thereof.

29. The composition of any one of claims 19-28, wherein the non-ionic surfactant v) is selected from the group consisting of alkyl phenol ethoxylates, polysiloxane polyalkylene oxide copolymers, primary alcohol ethoxylates, fatty alcohol ethoxylates, fatty acid ethoxylates, alkanolamide ethoxylates, fatty amine ethoxylates, ethylene oxide-propylene oxide (EO-PO) block copolymers, alkylpolyglucosides, and mixtures thereof.

30. The composition of any one of claims 19-29, wherein the vi) one or more free radical polymerizable ethylenically unsaturated monomers in the second polymer are selected from the group consisting of one or more alkyl(meth)acrylates, styrene, and mixtures thereof.

31. The composition of any one of claims 19-30, wherein the vii) one or more acid monomers in the second polymer are selected from the group consisting of acrylic acid, methacrylic acid, itaconic acid, maleic acid, fumaric acid, linolenic acid, 3-butenoic acid.

32. The composition of any one of claims 19-31, wherein the viii) free radical polymerizable monomer having a crosslinkable functionality in the second polymer are selected from the group consisting of diacetone acrylamide, acetoacetoxyalkyl(meth)acrylate, 2-acetoacetoxyethyl (meth)acrylate, 3-acetoacetoxypropyl (meth)acrylate, 4-acetoacetoxybutyl (meth)acrylate, 2-cyanoacetoxyethyl (meth)acrylate, 3-cyanoacetoxypropyl (meth)acrylate, 4-cyanoacetoxybutyl (meth)acrylate, N-(2-acetoacetoxyethyl) (meth)acrylamide, allyl acetoacetate, 2,3-di(acetoacetoxy)propyl (meth)acrylate, vinyl acetoacetate, and combinations thereof.

33. The composition of any one of claims 19-32, wherein the anionic surfactant ix) is selected from the group consisting of alkylbenzenesulfonic acids, alkaline earth metal alkylbenzenesulfonates, sulfonated fatty acids, sulfonated olefins, sulfonated diphenyl ethers, sulfosuccinates, fatty alcohol sulfates, alkylphenol sulfates, alkyl polyglycol ether sulfates, fatty alcohol ether sulfates, fatty alcohol phosphates, alkylphenol phosphates, alkyl polyglycol ether phosphates, alkyl polyalkylene oxide phosphates, fatty alcohol ether phosphates, and mixtures thereof.

34. The composition of any one of claims 19-33, wherein the non-ionic surfactant x) is selected from the group consisting of alkyl phenol ethoxylates, polysiloxane polyalkylene oxide copolymers, primary alcohol ethoxylates, fatty alcohol ethoxylates, fatty acid ethoxylates, alkanolamide ethoxylates, fatty amine ethoxylates, ethylene oxide-propylene oxide (EO-PO) block copolymers, alkylpolyglucosides, and mixtures thereof.

35. The method of any one of claims 19-34, wherein the binder is a polymer latex, wherein the polymer latex comprises, as polymerized monomer, at least one ethylenically unsaturated monomer.

36. The polymer latex of claim 35, wherein the ethylenically unsaturated monomer comprises at least one of vinyl aromatic monomers, methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethyl hexyl acrylate, (meth)acrylic acid, or a combination thereof, and wherein the glass transition temperature of the polymer latex, calculated using the Fox equation, is between -60°C to 20°C.

37. A non-aqueous adhesive layer for secondary battery comprising the composition according to any one of claims 1 -18.

38. The non-aqueous adhesive layer according to claim 37, further comprising an additive selected from neutralizers, leveling agents, emulsifiers, rheology control additives, additional polymers, dispersants or surfactants, defoamers, thickeners, stabilizers, viscosity stabilizers, biocides, solvents, rheology modifiers, wetting or spreading agents, conductive additives, thermal insulating fillers, adhesion promoters, antiblocking agents, anti-cratering agents or anti-crawling agents, anti-static agents, flame retardants, chelating agents, cross-linking agents, flattening agents, insecticides, lubricants, oils, waxes, or inorganic particles such as ceramic particles.

39. A separator comprising a substrate and the non-aqueous adhesive layer according to claim 37 or 38, wherein the non-aqueous adhesive layer is deposited on at least one surface of the substrate.

40. The separator according to claim 39, wherein the non-aqueous adhesive layer is deposited on two opposite surfaces of the substrate.

41. The separator according to claim 39 or 40, wherein the substrate is a coated porous membrane or an uncoated porous membrane.

42. The separator according to any one of claims 39-41, wherein the substrate is a coated porous membrane, and wherein a surface of the porous membrane is coated with a ceramic layer.

43. The separator according to any one of claims 39-42, wherein a thickness of the porous substrate is from about 3 pm to about 50 pm.

44. The separator according to any one of claims 39-43, wherein a thickness of the non-aqueous adhesive layer is from about 0.1 pm to about 5 pm.

45. The separator according to any of claims 39-45, wherein the Gurley value of the separator is increased by less than 30% relative to the Gurley value of the base substrate without the non-aqueous adhesive layer, the percentage increase being determined by the formula:(Gurley value of the adhesive layer-coated base substrate - Gurley value of the uncoated base substrate) * Gurley value of the uncoated base substrate).

46. A second battery comprising a positive electrode, a negative electrode, and a separator according to any one of claims 39-45.

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