Preparation of an Aqueous Dispersion of Acrylate-Siloxane Copolymer Particles

Abstract

The present invention provides a polymerizable composition comprising a) an acrylate monomer, b) an acid monomer, and c) a siloxane-acrylate monomer of formula (I), wherein R, R 1 , R 2 and copolymer particles comprising the structural units of siloxane-acrylate monomers, Y, and x, as defined herein. The method also requires the use of specific classes of anionic and nonionic surfactants as described herein. The aqueous dispersions prepared by the method of the present invention are useful in a variety of applications ranging from architectural coatings to personal care products. [Formula 1] JPEG2023514072000019.jpg22128

Description

Technical Field

[0001] The present invention relates to an aqueous dispersion of copolymer particles containing structural units of acrylate monomers and siloxane - acrylate monomers. The compositions of the present invention are useful for coating and personal care applications.

Background Art

[0002] Aqueous hybrid latex compositions containing copolymer particles functionalized with acrylate groups and siloxane groups provide improved performance in coating and cosmetic applications such as improved dyeing and solvent resistance, water and oil repellency, non - biofouling properties, and high tactile feel compared to all - acrylic compositions.

[0003] Xiao, J. et al., Prog. Org. Coat. 2018, 116, 1 - 6 and Zhang, B. et al., Appl. Surf. Sci. 2007, 254, 452 - 458 have reported the preparation of polymer dispersions of siloxane - acrylic hybrid particles. However, it has been shown by the inventors that the processes used to prepare these dispersions result in latexes having high levels of gel and unreacted monomers. The formation of high concentrations of gel, a strong indicator of an inefficient process, can lead to fouling of the reactor and contribute to poor properties of the final coating. Furthermore, the concentration of the incorporated siloxane - containing monomer in each of these reported processes was well below 10 weight percent, which limits the effectiveness of the dispersion. It is widely recognized that by achieving a relatively high level of incorporated siloxane - containing monomer (e.g., >20 weight %) in the final dispersed copolymer particles, coating and personal care formulation additives that exhibit improved properties related to the desired siloxane - containing oligomers and polymers can be obtained.

[0004] Therefore, it would be advantageous to prepare an aqueous dispersion of siloxane - acrylate copolymer particles functionalized with relatively high concentrations of structural units of siloxane - containing monomers.

Summary of the Invention

[0005] The present invention relates to 1) adding a first portion of an aqueous monomer emulsion to a container containing water and an anionic surfactant, the contents of the container being stirred and controlled at a temperature in the range of 60°C to 95°C; 2) adding a first portion of an initiator to the container to form an aqueous dispersion of seed copolymer particles over time; and then 3) adding a second portion of the monomer emulsion and a second portion of the initiator to the container; and then 4) maintaining the temperature of the contents of the container in the range of 60°C to 95°C for a time sufficient to achieve substantially complete conversion of the monomer in the monomer emulsion to polymer particles containing structural units of the monomer, thereby addressing a need in the art, The monomer emulsion has an average monomer droplet size in the range of 1 μm to 30 μm and, based on the weight of the monomer, comprises a) 40 to 98.8 weight percent acrylate monomer, b) 0.1 to 5 weight percent acid monomer, c) 1 to 59.8 weight percent siloxane acrylate monomer, 0.5 to 5 weight percent nonionic surfactant, and 0.5 to 5 weight percent anionic surfactant, The siloxane acrylate monomer is represented by the following formula I,

[0006]

Chemical formula

[0007] [Chemical Formula] In the formula, n is 0 to 10, p is 2 to 30, provided that p ≥ n, and R 3 is a linear or branched C3-C 16 -alkyl group, The anionic surfactant is represented by Formula III,

[0008] [Chemical Formula] In the formula, R 4 is C6-C 20 -alkyl, m is 0 to 10, and M is Li, Na, or K.

[0009] The present invention addresses the need in the art by providing a method for increasing the incorporation of siloxane-based monomers into copolymer particles with minimal gel formation. [Embodiments for Carrying Out the Invention]

[0010] The present invention 1) adding a first portion of an aqueous monomer emulsion to a container containing water and an anionic surfactant, wherein the contents of the container are stirred and controlled at a temperature in the range of 60°C to 95°C; 2) adding a first portion of an initiator to the container to form an aqueous dispersion of seed polymer particles over time; and then 3) adding a second portion of the monomer emulsion and a second portion of the initiator to the container; and then 4) maintaining the temperature of the contents of the container in the range of 60 °C to 95 °C for a time sufficient to achieve substantially complete conversion of the monomers in the monomer emulsion to polymer particles containing the structural units of the monomers; A method for preparing an aqueous dispersion of acrylate-siloxane copolymer particles, comprising: The monomer emulsion has an average monomer droplet size in the range of 1 μm to 30 μm and, based on the weight of the monomers, a) 40 to 98.8 weight percent of an acrylate monomer, b) 0.1 to 5 weight percent of an acid monomer, c) 1 to 59.8 weight percent of a siloxane acrylate monomer, 0.5 to 5 weight percent of a nonionic surfactant, and 0.5 to 5 weight percent of an anionic surfactant. The siloxane acrylate monomer is represented by the following formula I:

[0011] [Chemical formula] In the formula, R is H or CH3; R 1 is H or CH3; Each R 2 is independently CHCH3 or O-Si(CH3)3; Y is -CH2- or -CH2CH2-; x is 0 or 1; However, when x is 1, R 1 is H, when Y is -CH2-, R 1 is H, when Y is -CH2CH2-, R 1 is CH3, and provided that x is 0; The nonionic surfactant is represented by formula II:

[0012] [Chemical formula] In the formula, n is 0 to 10, p is 2 to 30, provided that p ≥ n, and R 3 is a linear or branched C3-C 16- an alkyl group, The anionic surfactant is represented by Formula III,

[0013]

Chemical formula

[0014] As used herein, the term "structural unit" of the listed monomer refers to the residue of the monomer after polymerization. For example, the structural unit of methyl methacrylate (MMA) is as shown below,

[0015]

Chemical formula

[0016] As used herein, "substantially complete conversion of the monomer" refers to at least 98%, preferably at least 99% conversion of all monomers to copolymer particles.

[0017] As used herein, the term "acrylate monomer" refers to one or more acrylate and / or methacrylate monomers. Examples of suitable acrylate monomers include MMA, n-butyl methacrylate (BMA), ethyl acrylate (EA), n-butyl acrylate (BA), and 2-ethylhexyl acrylate (2-EHA). Preferably, at least 80, more preferably at least 90 weight percent of the acrylate monomer is a combination of MMA and BA.

[0018] Examples of suitable acid monomers include carboxylic acid monomers, phosphoric acid monomers, and sulfuric acid monomers. Examples of preferred carboxylic acid monomers include acrylic acid (AA), methacrylic acid (MAA), and itaconic acid (IA), and their salts.

[0019] Examples of suitable phosphoric acid monomers include phosphonates and dihydrogen phosphate esters of alcohols that contain or are substituted with polymerizable vinyl or olefin groups. Preferred dihydrogen phosphate esters are phosphates of hydroxyalkyl acrylates or methacrylates including phosphoethyl methacrylate (PEM) and phosphopropyl methacrylate.

[0020] Examples of suitable sulfuric acid monomers include sulfoethyl methacrylate, sulfopropyl methacrylate, styrene sulfonic acid, vinyl sulfonic acid, and 2-acrylamido-2-methylpropanesulfonic acid (AMPS), and their salts.

[0021] In one aspect, the weight-to-weight ratio of BA to MMA ranges from 45:55 to 55:45, and in another aspect, the weight-to-weight ratio of acrylate monomers, preferably BA and MMA to acid monomers, preferably MAA, ranges from 99.95:0.05, more preferably from 99.5:0.5 to 97:3, more preferably 98:2.

[0022] The preferred range of the siloxane acrylate monomer of Formula I is application-dependent. For household and personal care applications such as cosmetics, hair care, and skin care, for example, the weight percentage of the monomer of Formula I based on the weight of the total monomer is preferably in the range of 20, more preferably 30, and most preferably 45% to 55% by weight based on the weight of the copolymer particles. For coating applications, the preferred weight percentage is in the range of 2% by weight, more preferably 3% to 20% by weight, more preferably 15% by weight, and most preferably 10% by weight based on the weight of the copolymer particles.

[0023] Examples of the monomer of Formula I include the following.

[0024]

Chem.

[0025] The nonionic surfactant of Formula II preferably contains a branched alkyl group, n is preferably in the range of 0 to 5, and p is preferably in the range of 3 to 16. Examples of suitable commercially available nonionic surfactants include TERGITOL™ 15-S-9 nonionic surfactant (15-S-9, a trademark of The Dow Chemical Company or its affiliates), TERGITOL™ TMN-3 nonionic surfactant (TMN-3), TERGITOL™ TMN-6 nonionic surfactant (TMN-6), TERGITOL™ TMN-10 nonionic surfactant (TMN-10), ECOSURF™ EH-6 nonionic surfactant (EH-6, a trademark of The Dow Chemical Company or its affiliates). The structures of these surfactants are as shown below:

[0026]

Chem.

[0027] The anionic surfactant of formula III is preferably a linear C 10 ~C 14 -alkyl sulfate, and m is 0. A preferred anionic surfactant is sodium lauryl sulfate (SLS). The concentration of the anionic surfactant of formula III is preferably in the range of 1 to 3 weight percent, based on the weight of the monomer. Preferably, the weight-to-weight ratio of the anionic surfactant to the nonionic surfactant is in the range of 1:2 to 2:1.

[0028] A preferred method for preparing an aqueous dispersion of acrylate-siloxane copolymer particles is 1) adding a first portion of an aqueous monomer emulsion to a container containing water, an anionic surfactant, and preferably a nonionic surfactant, the contents of the container being stirred and controlled at a temperature preferably in the range of 80°C to 95°C; 2) adding a first portion of an initiator to the container to form an aqueous dispersion of seed polymer particles over time, and then 3) gradually adding a second portion of the monomer emulsion and a second portion of the initiator to the container, and then 4) maintaining the temperature of the contents of the container for a time sufficient to achieve at least 99% conversion of the monomer to copolymer particles containing the structural units of the monomer, preferably in the range of 80°C to 95°C.

[0029] Preferably, after step 4), a redox initiator package is added to the container, and it is also preferred to neutralize the aqueous dispersion to a pH in the range of 6.5 to 7.5 after step 4). It is more preferred to add the redox initiator package after step 4) and then neutralize.

[0030] Surprisingly, the efficient incorporation of the high levels of the siloxane acrylate monomer of Formula I into the siloxane-acrylate copolymer can be achieved by the process of the present invention without substantially forming coagulum (gel) and large diameter particles (i.e., particles having a particle size diameter >1 μm and <40 μm as determined by single particle optical sensing described herein) as determined gravimetrically.

[0031] Determination of Suspended Polymer Levels by AccuSizer The amount of suspended polymer in the copolymer particle dispersion was measured using an AccuSizer 7000 APS single particle optical sensor instrument (Particle Sizing Systems (PSS), Entegris Company, Port Richey, FL). The copolymer particle dispersion was diluted 1000-fold with MilliQ water and then injected into the sample chamber of the instrument. The experimental method applied a two-step dilution of the injected sample, applying a first dilution of 21.6 in the pre-dilution chamber and a second dilution of 78.4 in the second stage dilution zone of the instrument. After data collection was complete, the sample chamber was flushed with MilliQ water until a baseline threshold of less than 200 counts per milliliter was observed. The sampling method was set to measure a total count of approximately 100,000, and particles measured with a diameter >1 μm were defined as suspended polymer. The samples were run in duplicate and the data presented as an average. The data was collected and processed using PSS software (version 2.3.1.6).

[0032] Example 1 - Preparation of an Aqueous Dispersion of Hybrid Copolymer Particles Using a Mixture of SLS and 15 - S - 9 Nonionic Surfactant Deionized water (150.0 g), Polystep B-5-N sodium lauryl sulfate (SLS, 3.0 g, 28.0% in water), and 15-S-9 (3.0 g) were added to a 500 mL four-neck round-bottom flask equipped with a condenser, an overhead stirrer, and a thermocouple. The contents of the reactor were stirred at 250 rpm and heated to 88 °C under N2. In a separate container, a monomer emulsion (ME) containing deionized water (180.0 g), SLS (14.1 g, 28.0% in water), 15-S-9 (3.0 g), BA (73.5 g), MMA (73.5 g), MAA (3.0 g), MD’M-ALMA (150.0 g), n-dodecyl mercaptan (n-DDM, 0.15 g), ammonium hydroxide solution (2.8 g, 28% active in water), and sodium acetate (0.9 g) was prepared using an overhead mixer, followed by treatment with a handheld homogenizer (Tissue Tearor, model 985370, Biospec Products Inc.) for 1 minute to produce an ME with an average droplet size of about 2 - 15 μm as determined by optical microscopy. A portion of the ME (20.0 g) was added to the reactor while rinsing (with 5.0 g of water), followed by ammonium persulfate (APS, 0.09 g) was added while rinsing with (2.0 g of water). The remainder of ME and the solution of APS (0.32 g in 24.0 g of water) were simultaneously fed to the reactor over 120 minutes at a temperature of 87 - 88 °C. When the feeding was complete, the reactor was then held at 87 - 88 °C for an additional 30 minutes. The reactor was then cooled to 60 °C, and then (i) Luperox TAH 85 t-amyl hydroperoxide (t-AHP, 0.29 g, 85 wt% active in water), SLS (0.06 g, 28% active in water), and deionized water (3.0 g), and (ii) isoascorbic acid (IAA, 0.15 g), VERSENE™ EDTA (EDTA, a trademark of Dow, Inc. or its affiliates, 0.3 g, 1% active in water), and the solution of ferrous sulfate (2.1 g, 0.15% active in water) were added to the reactor. The reactor was then cooled to room temperature, and ammonium hydroxide solution (28% active in water) was added dropwise to adjust the pH to about 7.0. The aqueous dispersion was continuously filtered through stainless steel mesh screens with pore sizes of 840 μm, 150 μm, and 40 μm. The final aqueous particle dispersion had 43.0% solids, a z-average particle size of 103 nm as determined by DLS, a final polymer coagulum (gel) level of 0.11 wt% (based on monomer, total gel collected at each mesh size), and a suspended polymer of 0.43 wt% (based on monomer) as determined by Accusizer characterization. The level of residual MD’M-ALMA in the sample was <30 ppm as determined by UHPLC.

[0033] Preparation of an Aqueous Dispersion of Hybrid Copolymer Particles Using a Mixture of SLS and TMN-6 Nonionic Surfactant Example 1 was repeated except that the 500 mL four-neck round-bottom flask and the 15-S-9 nonionic surfactant in ME were replaced with an equal mass of TMN-6 nonionic surfactant. The final aqueous particle dispersion had 42.8% solids, a z-average particle size of 100 nm as determined by DLS, a final polymer gel level of 0.12 wt% (total gel collected at each mesh size, based on monomer), and a suspended polymer level of 1.75 wt% (based on monomer) as determined by Accusizer characterization. The level of residual MD’M-ALMA in the sample was <30 ppm as determined by UHPLC.

[0034] Preparation of an Aqueous Dispersion of Hybrid Copolymer Particles Using a Mixture of SLS and TMN-10 Nonionic Surfactant Example 1 was repeated except that the 500 mL four-neck round-bottom flask and the 15-S-9 nonionic surfactant in ME were replaced with an equal mass of TMN-10 nonionic surfactant. The final aqueous particle dispersion had 42.7% solids, a z-average particle size of 115 nm as determined by DLS, a final polymer gel level of 0.18 wt% (total gel collected at each mesh size, based on monomer), and a suspended polymer level of 1.01 wt% (based on monomer) as determined by Accusizer characterization. The level of residual MD’M-ALMA in the sample was <30 ppm as determined by UHPLC.

[0035] Preparation of an Aqueous Dispersion of Hybrid Copolymer Particles Using a Mixture of SLS and EH-6 Nonionic Surfactant Example 1 was repeated except that the 500 mL four-neck round-bottom flask and the 15-S-9 nonionic surfactant in ME were replaced with an equal mass of EH-6 nonionic surfactant. The final aqueous particle dispersion had 42.5% solids, a z-average particle size of 103 nm as determined by DLS, a final polymer gel level of 0.18 wt% (total gel collected at each mesh size, based on monomer), and a suspended polymer of 1.75 wt% (based on monomer) as determined by Accusizer characterization. The level of residual MD’M-ALMA in the sample was <30 ppm as determined by UHPLC.

[0036] Preparation of an Aqueous Dispersion of Hybrid Copolymer Particles Using Comparative Example 1 - SLS Example 1 was repeated except that SLS was added to both the 500 mL four-neck round-bottom flask (13.36 g, 1.29 wt% based on monomer) and ME (24.45 g, 2.36 wt% based on monomer). The final aqueous copolymer particle dispersion had 37.8% solids, a z-average particle size of 78 nm as determined by DLS, a final polymer gel level of 2.50 wt% (total gel collected at each mesh size, based on monomer), and a suspended polymer of 1.60 wt% (based on monomer) as determined by Accusizer characterization. The level of residual MD’M-ALMA in the sample was 2500 ppm as determined by UHPLC.

[0037] Preparation of an Aqueous Dispersion of Hybrid Copolymer Particles Using Comparative Example 2 - 15-S-9 Nonionic Surfactant Example 1 was repeated except that 15-S-9 was added to both the 500 mL four-neck round-bottom flask (6.00 g, 2.00 wt% based on monomer) and ME (17.1 g, 5.70 wt% based on monomer). The copolymer particle dispersion gelled irreversibly in about 100 minutes in the ME feed. (46.2% solids theoretical, 19.8% actual)

[0038] Preparation of an Aqueous Dispersion of Hybrid Copolymer Particles by the Xiao ProcessThe process for preparing an aqueous dispersion of hybrid particles described in Xiao, J. et al., Prog. Org. Coatings 2018, 116, 1 - 6 was reproduced. Synthesis was carried out using a 500 mL four - neck round - bottom flask equipped with a condenser, an overhead stirrer, and a thermocouple. Deionized water (19.0 g) and SLS (1.43 g, 28.0% in water), TRITON™ X - 100 polyethylene glycol, t - octylphenyl ether (trademark of Dow, Inc. or its related companies, 0.80 g), and sodium bicarbonate (NaHCO3, 0.40 g) were added to the flask. The contents of the reactor were stirred at 100 rpm and heated to 60 °C under N2. In a separate container, ME containing deionized water (48.5 g), SLS (2.14 g, 28.0% in water), Triton X - 100 (1.20 g), BA (BA, 44.8 g), MMA (42.3 g), styrene (10.1 g), and AA (1.9 g) was prepared using an overhead mixer. A portion of ME (15.1 g) was added to the reactor, followed by the addition of APS (0.13 g) in deionized water (10.0 g), and the temperature of the reactor was raised to 80 °C over 10 minutes. The remainder of ME and a solution of APS (0.27 g in 20.0 g of water) were simultaneously fed to the reactor at a temperature of 80 - 81 °C over 4.5 hours and 5 hours, respectively (i.e., the APS feed was continued for 30 minutes after the completion of the ME feed). At the 3 - hour mark of the feed, MD’M ALMA was added to the reactor (10.0 g). When the APS feed was completed, the reactor was then held at 80 °C for an additional 30 minutes. The reactor was then cooled to room temperature, and an ammonium hydroxide solution (28% active in water) was added dropwise to raise the pH to approximately 8.5. The aqueous dispersion was continuously filtered through stainless - steel mesh screens with pore sizes of 150 μm and 40 μm. The final aqueous particle dispersion had 44.3% (theoretical value = 53.0%) solids, a z - average particle size of 135 nm determined by DLS, a final polymer gel level of 0.80 wt% (based on monomer, the sum of gels collected at each mesh size), and a suspended polymer of 2.69 wt% (based on monomer) determined by Accusizer characterization. The level of residual MD’M - ALMA in the serum phase was 13,700 ppm determined by UHPLC.

[0039] Preparation of an Aqueous Dispersion of Hybrid Copolymer Particles by the Comparative Example 4 - Zhang Process The process for preparing an aqueous dispersion of hybrid particles as described in Zhang, B. et al., Appl. Surf. Sci. 2007, 254, 452 - 458 was reproduced. Deionized water (60.0 g), sodium dodecylbenzenesulfonate (0.30 g), and Span 20 sorbitan monolaurate (0.50 g) were added to a 100 mL glass reactor equipped with a condenser, overhead stirrer, and thermocouple. The contents of this reactor were stirred at 100 rpm, heated to 80 °C, and sparged with N2 for 30 minutes. In a separate container, a monomer mixture consisting of MMA (12.0 g), BA (12.0 g), and MD’M - ALMA (1.2 g) was prepared. The monomer mixture and a solution of APS (0.05 g in 10.0 g of water) were simultaneously fed to the reactor over 120 minutes at a temperature of 80 - 81 °C. When the feed was complete, the reactor was then held at 80 - 81 °C for an additional 6 hours. The reactor was then cooled to room temperature, and an ammonium hydroxide solution (28% active in water) was added dropwise to raise the pH to approximately 7.0. The final aqueous particle dispersion had 22.8% (theoretical value = 27.1%) solids, a z - average particle size of 64 nm as determined by DLS, a final polymer gel level of 1.97 wt% (based on monomers, total gel collected at each mesh size), and a suspended polymer of 0.66 wt% (based on monomers) as determined by Accusizer characterization. The level of residual MD’M - ALMA in the serum phase was 13,700 ppm as determined by UHPLC.

[0040] Table 1 shows the type and corresponding mass of monomer-based surfactants added to the monomer emulsion (ME) and / or kettle, the amount of unreacted residual siloxane-acrylate monomer (final MD’M-ALMA), the concentration of suspension copolymer particles formed having a diameter > 1 μm and < 40 μm (suspended polymer ppm) based on the monomer, the concentration of the gel formed based on the monomer (gel ppm), and the total concentration of both the gel and suspension copolymer particles expressed as weight percent based on the monomer (suspension + gel %). ND indicates that the monomer amount was not detected above 30 ppm (detection limit). The percentages of the starting materials in the monomer emulsion (ME) and kettle are based on the weight of the monomer. This table shows the importance of using both nonionic and anionic surfactants in a process to reduce gel formation and improve the conversion of the siloxane acrylate monomer MD’M-ALMA.

[0041]

Table 1

[0042] The data shows that a high concentration of siloxane-acrylate monomer can be incorporated into copolymer particles having relatively low gel formation and low residual monomer.

Claims

1. A method for preparing an aqueous dispersion of acrylate-siloxane copolymer particles, comprising: 1) adding a first portion of an aqueous monomer emulsion to a container containing water and an anionic surfactant, wherein the contents of the container are stirred and controlled at a temperature in the range of 60°C to 95°C; 2) adding a first portion of an initiator to the container to form an aqueous dispersion of seed copolymer particles over time; and then 3) adding a second portion of the monomer emulsion and a second portion of the initiator to the container; and then 4) maintaining the temperature of the contents of the container in the range of 60°C to 95°C for a time sufficient to achieve substantially complete conversion of the monomers in the monomer emulsion to polymer particles containing the structural units of the monomers. The monomer emulsion has an average monomer droplet size in the range of 1 μm to 30 μm and, based on the weight of the monomers, comprises: a) 40 to 98.8 wt% of an acrylate monomer; b) 0.1 to 5 wt% of an acid monomer; c) 1 to 59.8 wt% of a siloxane acrylate monomer; 0.5 to 5 wt% of a nonionic surfactant of the monomer emulsion; and 0.5 to 5 wt% of an anionic surfactant of the monomer emulsion. The siloxane acrylate monomer is represented by the following formula I: 【Chemical 1】 wherein R is H or CH ３ and R １ is H or CH ３ and Each R ２ is independently CH ３ or O—Si(CH ３ ) ３ and Y is -CH ２ - or -CH ２ CH ２ - and x is 0 or 1; However, when x is 1, R １ is H, and when Y is -CH ２ -, R １ is H, and when Y is -CH ２ CH ２ -, R １ is CH ３ on the condition that x is 0, The nonionic surfactant of the monomer emulsion is represented by formula II; [Chemical Formula 2] In the formula, n is from 0 to 10, p is from 2 to 30, provided that p ≥ n, and R ３ is a linear or branched C ３ to C １６ -alkyl group, The anionic surfactant contained in the container and the anionic surfactant of the monomer emulsion are represented by formula III. 【Chemical 3】 wherein R ４ is C ６ -C ２０ -alkyl, m is 0 to 10, and M is Li, Na, or K, a method.

2. The siloxane-acrylate monomer is 【Chemical 4】 The method according to claim 1.

3. n is in the range of 0 to 5, p is in the range of 3 to 16, the anionic surfactant of formula III contained in the container and the anionic surfactant of formula III of the monomer emulsion are linear C １０ to C １４ -alkyl sulfates, wherein m is 0, and the weight percentage of the structural unit of the siloxane-acrylate monomer is in the range of 20 to 55 weight percent based on the weight of the copolymer particles, the method according to claim 2.

4. The acrylate monomer is butyl acrylate and methyl methacrylate, the acid monomer is methacrylic acid, the weight-to-weight ratio of butyl acrylate to methyl methacrylate is in the range of 45:55 to 55:45, and the weight-to-weight ratio of butyl acrylate and methyl methacrylate to methacrylic acid is in the range of 99.5:0.5 to 97:

3. The method according to claim 3. **Claim 5**: The concentrations of the nonionic surfactant of Formula II and the anionic surfactant of Formula III in the monomer emulsion are each in the range of 1 to 3 weight percent based on the weight of the monomer, and the weight-to-weight ratio of the nonionic surfactant in the monomer emulsion to the anionic surfactant in the monomer emulsion is in the range of 1:2 to 2:

1. The nonionic surfactant in the monomer emulsion is 【Chemical Formula 5】 wherein p is 3, 8, or 11. The method according to claim 4. **Claim 6**: The nonionic surfactant in the monomer emulsion is represented by 【Chemical Formula 6】 The anionic surfactant contained in the container and the anionic surfactant in the monomer emulsion are sodium lauryl sulfate, and the siloxane-acrylate monomer of Formula I is [Chemical Formula 7] The method according to claim 5. **Claim 7** In step 1), the container containing water and the anionic surfactant of Formula III further contains the nonionic surfactant of Formula II, and the contents of the container are stirred and controlled at a temperature in the range of 80 °C to 95 °C. The method according to claim 1. **Claim 8** After step 4), a redox initiator package is added to the container. The method according to claim 7. **Claim 9** After step 4), a redox initiator package is added to the container, followed by the addition of a neutralizing agent. The method according to claim 7.

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