Use of sulfated ethoxylated C8-11 branched alkanols in emulsion polymerization and method for producing polymer latices

Abstract

The invention relates to the use of sulfated ethoxylated C8-11 branched alkanols as anionic surfactants for producing polymer latexes in emulsion polymerization, to a method for producing polymer latexes by emulsion polymerization in the presence of anionic surfactants selected from the group of sulfated ethoxylated C8-11 branched alkanols, and a polymer latex obtained or obtainable by emulsion polymerization using an anionic surfactant selected from the group consisting of sulfated ethoxylated C8-11 branched alkanols.

Description

Technical Field

[0001] This invention relates to sulfated ethoxylated C 8-11 The use of branched alkanols in emulsion polymerization to produce polymer latex, one of which is used in the production of polymer latexes selected from sulfated and ethoxylated C464. 8-11 A method for preparing polymer latex via emulsion polymerization in the presence of anionic surfactants of branched alkanols, and the use of sulfated ethoxylated C 8-11 Anionic surfactants of branched alkanols are obtained or can be obtained as polymer latexes through emulsion polymerization. Background Technology

[0002] In CASE (i.e., coatings, adhesives, sealants, elastomers) applications, low-VOC formulations are receiving increasing attention from both manufacturers and end-users due to growing environmental awareness and the implementation of stricter environmental regulations. In recent years, developing suitable aqueous polymer emulsions or dispersions (also known as polymer latexes) to replace conventional solvent-based polymer emulsions or dispersions available for CASE has been a challenge.

[0003] To prepare polymer latexes, emulsion polymerization is typically used, in which monomers (e.g., (meth)acrylic acids, vinyl compounds, etc.) are polymerized in an aqueous medium in the presence of free radicals. In emulsion polymerization, emulsifiers are essential and necessary for stabilizing the system during polymerization and for the resulting dispersed polymer particles. Selecting a suitable emulsifier for the emulsion polymerization method to provide a latex with the desired particle size and stability for the intended application is quite important.

[0004] Anionic and nonionic surfactants are widely used as emulsifiers in emulsion polymerization processes to provide polymer latexes suitable for CASE applications. Typically, anionic surfactants are used alone or in combination with nonionic emulsifiers. Typical anionic emulsifiers are sodium, potassium, or ammonium salts of fatty acids and C... 12-16 Alkyl sulfates. Typical nonionic emulsifiers include fatty alcohol alkoxylates. Typical protective colloids are, for example, poly(ethylene oxide), poly(vinyl alcohol), and hydroxyethyl cellulose.

[0005] High solids content is one of the main goals pursued in polymer latex production because it reduces production time per unit volume of material, as well as transportation and storage costs. However, the production of high-solids-content polymer latex presents several challenges, such as controlling the particle size, particle size distribution, and viscosity of the product. Furthermore, polymer latexes with high solids content, especially ultra-high solids content, typically exhibit high viscosity, making handling and subsequent application (e.g., dilution) difficult.

[0006] There is a need for a method for preparing polymer latex with high or ultra-high solids content by emulsion polymerization, wherein the polymer latex can have low viscosity and preferably large particle size. Summary of the Invention

[0007] The object of this invention is to find an anionic surfactant that can be used in emulsion polymerization methods to provide polymer latex with high or ultra-high solids content and low viscosity, and preferably large particle size and / or narrow particle size distribution.

[0008] The inventors discovered that this objective can be achieved by using ethoxylated C sulfate. 8-11 Branched alkanols, especially sulfated ethoxylated C8 Goerbert alcohols or sulfated ethoxylated C8... 10 Guerbert alcohol is used as an anionic surfactant for emulsion polymerization.

[0009] Therefore, in a first aspect, the present invention relates to sulfated ethoxylated C 8-11 Branched alkanols are used as anionic surfactants in emulsion polymerization to produce polymer latexes with a solid content of at least 35% by weight.

[0010] In some embodiments of the first aspect, the present invention relates to sulfated ethoxylated C 8-11 Branched alkanols are used as anionic surfactants in emulsion polymerization to produce polymer latexes with a solid content of at least 35% by weight, wherein sulfated ethoxylated C 8-11 Branched alkanols have a number-average degree of ethoxylation in the range of 2 to 8 (e.g., 2.5 to 6).

[0011] In a second aspect, the present invention relates to a method for use in the reaction of C selected from sulfated ethoxylated C 8-11 A method for producing polymer latex with a solid content of at least 35% by weight by emulsion polymerization in the presence of anionic surfactants of branched alkanols.

[0012] In some embodiments of the second aspect, the present invention relates to a method for use in the production of sulfated ethoxylated C having a number-average degree of ethoxylation in the range of 2 to 8, for example 2.5 to 6. 8-11 A method for producing polymer latex with a solid content of at least 35% by weight by emulsion polymerization in the presence of anionic surfactants of branched alkanols.

[0013] In a third aspect, the present invention relates to a method using a mixture selected from sulfated ethoxylated C 8-11 The branched alkanol anionic surfactant is obtained or available via emulsion polymerization of polymer latex having a solid content of at least 35% by weight.

[0014] In some embodiments of the third aspect, the present invention relates to a method using sulfated ethoxylated C having a number-average degree of ethoxylation in the range of 2 to 8, for example 2.5 to 6. 8-11 A polymer latex with a solid content of at least 35% by weight, obtained by emulsion polymerization of branched alkanol anionic surfactants.

[0015] In some additional embodiments of the third aspect, the present invention relates to a method using a mixture selected from sulfated ethoxylated C 8-11 A polymer latex with a solid content of at least 35% by weight, obtained by emulsion polymerization of branched alkanol anionic surfactants, comprising...

[0016] a) Styrene monomer units,

[0017] b) (Meth)acrylic acid monomer units, and

[0018] c) Optionally, olefinic unsaturated monomer units other than monomer units a) and b). Attached Figure Description

[0019] Figure 1 Photographs of the coagulated polymer latexes from Examples 5 (top left), 6 (top right), 7 (bottom left), and 8 (bottom right), produced by stability measurements, are shown. Detailed Implementation

[0020] Unless the context clearly specifies otherwise, the singular forms “a / an” and “the” include the plural indicator. The terms “comprise(s) / comprising” are interchangeable with “contain(s) / containing” and should be interpreted in a non-restrictive, open-ended manner. That is, for example, additional components or elements may exist. Expressions such as “consist(s) of / consisting of” or cognates may be included in “comprise(s) / comprising” or cognates. The terms “include(s) / including” should be interpreted in a non-restrictive, open-ended manner.

[0021] In this document, the term "high solids content" is intended to refer to a solids content of at least 35% and up to 50% by weight, as determined, for example, by drying polymer latex in an oven at 115°C for 2 hours.

[0022] In this document, the term "ultra-high solids content" is intended to refer to a solids content of greater than 50% by weight, for example up to 70% by weight, as determined by drying polymer latex in an oven at 115°C for 2 hours, for example.

[0023] In a first aspect, the present invention provides sulfated ethoxylated C 8-11 Branched alkanols are used as anionic surfactants in emulsion polymerization to produce polymer latexes having a solid content of at least 35% by weight, for example, 35% to 70% by weight.

[0024] In some embodiments, the present invention provides sulfated ethoxylated C 8-11 Branched alkanols are used as anionic surfactants in emulsion polymerization to produce polymer latexes with high solids content, i.e., polymer latexes with a solids content of 35% to 50% by weight.

[0025] In some other embodiments, the present invention provides sulfated ethoxylated C 8-11 Branched alkanols are used as anionic surfactants in emulsion polymerization to produce polymer latexes with ultra-high solid content, that is, polymer latexes with a solid content of more than 50% and up to 70% by weight.

[0026] Sulfated ethoxylated C 8-11 Branched alkanols can also be called C sulfated alkanols. 8-11 Branched alkanol ethoxylates or C 8-11 Branched-chain alkanol ethoxylates sulfate. Typically used for the derivatization of ethoxylated C-sulfates. 8-11 Suitable C of branched alkanols 8-11 Branched alkanols can be 2-alkyl-1-alkanols with 8 to 11 carbon atoms, especially Guerbert alcohols.

[0027] In this article, sulfation and ethoxylation of C 8-11 Branched alkanols or can be produced by "sulfation and ethoxylation of C". 8-11 Any specific concept or substance covered by "branched alkanols" may also be referred to as an anionic surfactant according to the present invention.

[0028] In some embodiments, sulfated ethoxylated C 8-11 Branched alkanols can be sulfated or ethoxylated C 8-11 Guerbert alcohol, especially sulfated ethoxylated C8 Guerbert alcohol or C 10 Guerbert alcohol.

[0029] Preferably, sulfated ethoxylated C 8-11 Branched alkanols have a number-average degree of ethoxylation in the range of 2 to 8, for example 2.5 to 6, particularly 3 to 6, and even more particularly 3 to 5.

[0030] In some specific embodiments, sulfation ethoxylated C 8-11 Branched alkanols are sulfated ethoxylated C-type alkanols represented by formula (I). 10 Guerbert alcohol:

[0031] (I)

[0032] in

[0033] n represents the number-average degree of ethoxylation, preferably in the range of 2 to 8, more preferably in the range of 2.5 to 6, and

[0034] M + It is a cation, preferably a sodium cation, lithium cation, potassium cation, or ammonium cation.

[0035] It should be understood that the sulfated ethoxylated C applicable to this invention 10 Guerbert alcohol can be sulfated or ethoxylated C with different degrees of ethoxylation. 10 The form of a mixture of Guerbert alcohols. This is why the notation "n" in formula (I) may not necessarily be an integer.

[0036] Preferably, sulfated ethoxylated C 10 Guerbert alcohol has a number-average degree of ethoxylation in the range of 3 to 6, particularly 3 to 5, for example 3, 4 or 5.

[0037] In some illustrative embodiments, sulfation ethoxylated C 10 Gerbert alcohol has a degree of ethoxylation of 4 or 5, preferably 4.

[0038] Suitable sulfated ethoxylated C for use in this invention 10 Guerbert alcohol can be converted from the corresponding ethoxylated C 10 Guerbert alcohol is prepared by sulfonation via any conventional method. Commercially available ethoxylated C-type alcohols with degrees of ethoxylation of 3, 4, or 5 are available. 10 Examples of guerbert alcohol are known and are exemplified by Lutensol. ® XP30, Lutensol ® XP40 and Lutensol ® The XP50 comes from BASF SE in Ludwigshafen, Germany.

[0039] In some specific embodiments of the present invention, sulfated ethoxylated C8-C11 Guerbert alcohol may further comprise additional alkoxylated groups, such as propoxylated groups. In some specific embodiments of the present invention, sulfated ethoxylated C10 Guerbert alcohol may further comprise additional alkoxylated groups, such as propoxylated groups.

[0040] It is conceivable that the anionic surfactant according to the invention can be used in emulsion polymerization to produce various types of polymer latexes, such polymer latexes being based, for example, on one or more monomers selected from styrene monomers, conjugated diene monomers, vinyl monomers, (meth)acrylic monomers, or any combination thereof.

[0041] The anionic surfactant according to the invention can be used in emulsion polymerization at any amount of emulsifier known for use in emulsion polymerization, for example, 0.5% to 5% based on the total weight of the monomer.

[0042] In some embodiments, the present invention specifically provides sulfated ethoxylated C 8-11 Branched alkanols, as anionic surfactants, are used in emulsion polymerization to produce polymer latexes with high or ultra-high solids content from the following monomers.

[0043] a) Styrene monomers,

[0044] b) (Meth)acrylic acid monomers, and

[0045] c) Optionally, an olefinic unsaturated monomer other than monomers a) and b).

[0046] For example, polymer latexes with high or ultra-high solids content can be produced from the following monomers.

[0047] a) 25% to 50% styrene monomers by weight,

[0048] b) 50% to 75% by weight of (meth)acrylic acid monomers, and

[0049] c) 0% to 20% by weight of olefinic unsaturated monomers other than monomers a) and b).

[0050] Polymer latexes with high or ultra-high solids content can also be produced from the following monomers.

[0051] a) 30% to 50% by weight of styrene monomers

[0052] b) 50% to 70% by weight of (meth)acrylic acid monomers, and

[0053] c) 0% to 10% by weight of olefinic unsaturated monomers other than monomers a) and b).

[0054] Exemplary styrene monomers may include, but are not limited to, styrene, α-methylstyrene, α-ethylstyrene, vinyltoluene (such as 2-methylstyrene, 3-methylstyrene, and p-methylstyrene), 2,4-dimethylstyrene, 2,5-dimethylstyrene, p-α-dimethylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2-isopropylstyrene, 3-isopropylstyrene, 4-isopropylstyrene, p-tert-butylstyrene, or any combination thereof. Preferably, the styrene monomer may be selected from styrene, α-methylstyrene, or any combination thereof.

[0055] Exemplary (meth)acrylic monomers may include, but are not limited to, acrylic acid or its salts, methacrylic acid or its salts, acrylates (such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, and glycidyl acrylate), methacrylates (such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, 2-hydroxyethyl methacrylate, and glycidyl methacrylate), (meth)acrylamide (such as hydroxymethylacrylamide), acrylic anhydride, methacrylic anhydride, acrolein, methacrolein, acrylonitrile, methacrylonitrile, or any combination thereof. Preferably, the (meth)acrylic monomer may be selected from acrylic acid or its salts, methacrylic acid or its salts, acrylates (such as methyl acrylate, ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, and 2-hydroxyethyl acrylate), methacrylates (such as methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, 2-ethylhexyl methacrylate, and 2-hydroxyethyl methacrylate), or any combination thereof.

[0056] Exemplary olefinic unsaturated monomers other than monomers a) and b) may include, but are not limited to, vinyl esters (such as vinyl acetate), halogenated or halogenated vinylides (such as vinyl chloride and vinyl fluoride), heterocyclic vinyl compounds (such as vinylpyrrolidone and vinylimidazole), open-chain conjugated dienes (such as butadiene, isoprene and chloroprene), unsaturated acids (such as maleic acid and fumaric acid) and their derivatives (such as salts, anhydrides, esters and amides), or any combination thereof.

[0057] It should be understood that the anionic surfactant according to the present invention can be used alone or in combination with at least one other anionic surfactant or nonionic surfactant in emulsion polymerization to produce polymer latex with high or ultra-high solids content.

[0058] Emulsion polymerization can be carried out according to well-known methods for producing polymer latex suitable for CASE applications, without any particular limitations. Preferably, emulsion polymerization can be carried out according to the method according to a second aspect of the invention as described below.

[0059] The inventors have unexpectedly discovered that a polymer latex with low viscosity can be provided by using the anionic surfactant according to the invention in a system with high or ultra-high solid content for emulsion polymerization.

[0060] The inventors also unexpectedly discovered that polymer latexes obtained by using the anionic surfactant according to the invention have a large particle size and narrow particle size distribution.

[0061] The inventors have further and unexpectedly discovered that polymer latexes obtained by using the anionic surfactant according to the present invention exhibit excellent mechanical and storage stability.

[0062] In a second aspect, the present invention provides a method for [using] C selected from sulfated ethoxylated C 8-11 A method for producing polymer latex with a solid content of at least 35% by weight by emulsion polymerization in the presence of anionic surfactants of branched alkanols.

[0063] Selected from sulfated ethoxylated C 8-11 The anionic surfactant for branched alkanols is as described above with respect to the first aspect. In the context of the first aspect of the invention, regarding sulfated ethoxylated C... 8-11 Any general description or preference of branched alkanols may be incorporated herein by reference.

[0064] Furthermore, the monomers suitable for producing polymer latex in the method according to the second aspect are as described above in the context of the first aspect. Any general description or preference of the monomers described above is incorporated herein by reference.

[0065] A method for producing a polymer latex having a solid content of at least 35% by weight may include the following steps:

[0066] i) Supply monomers selected from sulfated ethoxylated C during the feed period 8-11 The branched alkanols contain anionic surfactants and initiators, during which the polymerization of the monomers begins and continues.

[0067] ii) Sustaining polymerization after the feed phase to allow for post-polymerization, thereby providing an aqueous polymer dispersion.

[0068] iii) Optionally, an anti-settling agent may be added after post-polymerization to provide an additional aqueous polymer dispersion.

[0069] iv) Optionally, a redox initiator system for monomer chasing is supplied, and

[0070] v) Perform post-processing to provide polymer latex.

[0071] The monomer and anionic surfactant can be pre-prepared as an aqueous emulsion so that they are supplied together to the reactor in the form of an aqueous emulsion in step i).

[0072] The initiator can be any initiator known for emulsion polymerization (such as ammonium persulfate, sodium persulfate, or potassium persulfate), or a redox system typically containing an oxidant and a reductant. Conventional redox initiator systems are described, for example, in Progress in Polymer Science 24 (1999), 1149-1204. The initiator can be supplied to the reactor as an aqueous solution in step i).

[0073] In step i), a portion of the initiator may initially be added to the water in the reactor, and the remaining portion of the initiator may be fed into the reactor in parallel with the supply of the aqueous emulsion of the monomer and the anionic surfactant.

[0074] Alternatively, in step i), a portion of the aqueous emulsion of monomer and anionic surfactant and a portion of the initiator may initially be added sequentially to water in the reactor and reacted to provide a seeding latex. Then, the remaining portion of the aqueous emulsion of monomer and anionic surfactant and the remaining portion of the initiator are fed into the reactor in parallel for primary polymerization.

[0075] The feeding time can vary depending on the feed rate and feed volume, and can be determined by a technician. Polymerization typically takes place at room temperature or at elevated temperatures, such as under heating. Any known temperature for emulsion polymerization can be applied, depending on the monomer, initiator, etc.

[0076] In step ii), after the feeding period in step i), the polymerization is maintained at the same temperature as in step i) for a certain period of time for post-polymerization, thereby ensuring complete polymerization.

[0077] Optionally, after polymerization is complete, i.e. in step (iii), an anti-settling agent and / or surfactant are added to the aqueous polymer dispersion as produced by step (ii).

[0078] The anti-settling agent / surfactant can be selected from substances known as nonionic surfactants and anionic surfactants, preferably the same as or different from the anionic surfactant according to the invention used for emulsion polymerization. Exemplary anti-settling agents / surfactants can include, but are not limited to, salts of alkyl sulfates, sulfonates, phosphates, phosphonates, especially salts of alkyl ether sulfates, such as C 8-22 Salts of alkyl ether sulfates. Antisettling agents / surfactants are commonly used to improve the stability of polymer latexes obtained (e.g., shelf stability).

[0079] Anti-settling agents / surfactants can be added entirely before polymerization, during polymerization, or added to the post-polymerization emulsion. For example, anti-settling agents / surfactants can be added continuously during polymerization, partially before polymerization and then added during polymerization, or added after polymerization has started and continued for a period of time.

[0080] Optionally, but preferably, in step iv), a redox initiator system for monomer chasing is added to the aqueous polymer dispersion produced as in step ii) or step iii) (if that step is performed).

[0081] As is known in the art, the term "monomer chasing" refers to the removal of residual monomers from an aqueous polymer dispersion using a redox initiator system that typically comprises at least one oxidant and at least one reductant. Suitable oxidants and reductants may be selected from those described in the context of redox initiator systems in US 20020099156 A1.

[0082] In particular, suitable oxidants for redox initiator systems may include, for example, peroxides, hydroperoxides, and mixtures thereof, such as tert-butyl peroxide, lauryl peroxide, tert-butyl hydroperoxide, tert-amyl hydroperoxide, cumyl hydroperoxide, or any combination thereof. Suitable reducing agents for redox initiator systems may include, for example, formaldehyde hyposulfite and its salts, such as sodium formaldehyde hyposulfite.

[0083] The oxidant and reductant of the redox initiator system can be added to the aqueous polymer dispersion in parallel during the feed phase. If the polymerization in steps i) and ii) is carried out at a high temperature, the monomer chasing in step iv) can be carried out at a lower temperature than that used for the polymerization.

[0084] In step v), conventional post-processing can be applied to provide polymer latex, such as neutralization, addition of desired additives, and filtration.

[0085] In some embodiments, the present invention provides a method for [using] a mixture selected from sulfated ethoxylated C 8-11A method for producing polymer latex with a solid content of 35% to 50% by weight via emulsion polymerization in the presence of anionic surfactants of branched alkanols. Specifically, the method according to these embodiments includes steps i), ii), iv), and v). For polymer latex with a solid content of 35% to 50% by weight, an anti-settling agent is not necessary and therefore step iii) may be excluded from the method.

[0086] In some other embodiments, the present invention provides a method for [using] a mixture selected from ethoxylated C [sulfate]. 8-11 A method for producing polymer latex with a solid content of more than 50% and up to 70% by weight by emulsion polymerization in the presence of anionic surfactants of branched alkanols. Specifically, the method according to these embodiments includes steps i), ii), iii), iv), and v).

[0087] In a third aspect, the present invention provides a method using a mixture selected from sulfated ethoxylated C 8-11 The branched alkanol anionic surfactant is obtained or available via emulsion polymerization of polymer latex having a solid content of at least 35% by weight.

[0088] Selected from sulfated ethoxylated C 8-11 The anionic surfactant for branched alkanols is as described above with respect to the first aspect. In the context of the first aspect of the invention, regarding sulfated ethoxylated C... 8-11 Any general description or preference of branched alkanols is incorporated herein by reference. Furthermore, monomers suitable for forming polymer latexes according to the second aspect are as described above in the context of the first aspect. Any general description or preference of the monomers described above is incorporated herein by reference.

[0089] In some embodiments of the third aspect, the present invention provides a polymer latex having a solid content of 35% to 50% and an average particle size greater than 200 nm, for example greater than 300 nm, as measured by dynamic light scattering (DLS) methods, such as using a Malvern Zetasizer Nano S90. Additionally, the polymer latex has a particle size distribution (PDI) of less than 0.2, as measured by dynamic light scattering (DLS) methods, such as using a Malvern Zetasizer Nano S90. Furthermore, in those embodiments, the polymer latex has a viscosity of no more than 40 centipoise (cP), preferably no more than 35 cP, more preferably no more than 30 cP, as measured by a Brookfield rotational viscometer with a #5 rotor at 23°C and 100 rpm.

[0090] In some other embodiments of the third aspect, the present invention relates to a polymer latex having a solid content of greater than 50% and up to 70% by weight, having an average particle size greater than 200 nm, as measured by dynamic light scattering (DLS) methods, for example using a Malvern Zetasizer Nano S90. Additionally, the polymer latex has a particle size distribution (PDI) of less than 0.2, as measured by dynamic light scattering (DLS) methods, for example using a Malvern Zetasizer Nano S90. Furthermore, in those embodiments, the polymer latex has a viscosity of no more than 3000 cP, preferably no more than 2000 cP, more preferably no more than 1800 cP, as measured by a Brookfield rotational viscometer with a #5 rotor at 23°C and 100 rpm.

[0091] Polymer latex can also contain any conventional additives, such as pH adjusters, defoamers, biocides, etc. Example

[0092] Various embodiments are listed below. It should be understood that the embodiments listed below can be combined with all aspects of the invention and other embodiments.

[0093] Example 1. Sulfated ethoxylated C 8-11 Branched alkanols are used as anionic surfactants in emulsion polymerization to produce polymer latexes with a solid content of at least 35% by weight.

[0094] Example 2. Sulfated ethoxylated C according to Example 1 8-11 Uses of branched alkanols, in which the sulfated ethoxylated C 8-11 Branched alkanols are sulfated ethoxylated C 8-11 Guerbert alcohol.

[0095] Example 3. Sulfated ethoxylated C according to Example 2 8-11 Uses of branched alkanols, in which the sulfated ethoxylated C 8-11 Branched alkanols are sulfated ethoxylated C8 Gelbert alcohols or C8 Gelbert alcohols. 10 Guerbert alcohol.

[0096] Example 4. Sulfated ethoxylated C according to Example 3 8-11 Uses of branched alkanols, including sulfation and ethoxylation of C 8-11 Branched alkanols are sulfated ethoxylated C-type alkanols represented by formula (I). 10 Guerbert alcohol:

[0097] (I)

[0098] in

[0099] n represents the number-mean degree of ethoxylation, and

[0100] M + It is a cation, preferably a sodium cation, lithium cation, potassium cation, or ammonium cation.

[0101] Example 5. Sulfated ethoxylated C according to any one of Examples 1 to 4 8-11 Uses of branched alkanols, in which the sulfated ethoxylated C 8-11 Branched alkanols have a number-average degree of ethoxylation in the range of 2 to 8.

[0102] Example 6. Sulfated ethoxylated C according to Example 5 8-11 Uses of branched alkanols, in which the sulfated ethoxylated C 8-11 Branched alkanols have a number-average degree of ethoxylation in the range of 2.5 to 6.

[0103] Example 7. Sulfated ethoxylated C according to Example 6 8-11 Uses of branched alkanols, in which the sulfated ethoxylated C 8-11 Branched alkanols have a number-average degree of ethoxylation in the range of 3 to 6.

[0104] Example 8. Sulfated ethoxylated C according to Example 7 8-11 Uses of branched alkanols, in which the sulfated ethoxylated C 8-11 Branched alkanols have a number-average degree of ethoxylation in the range of 3 to 5.

[0105] Example 9. Sulfated ethoxylated C according to Example 8 8-11 Uses of branched alkanols, in which the sulfated ethoxylated C 8-11 Branched alkanols have a number-average degree of ethoxylation of 3, 4, or 5.

[0106] Example 10. Sulfated ethoxylated C according to any one of Examples 1 to 9 8-11 Uses of branched alkanols, in which the sulfated ethoxylated C 8-11 Branched alkanols are used in emulsion polymerization at amounts ranging from 0.5% to 5% based on the total weight of the monomers.

[0107] Example 11. Sulfated ethoxylated C according to any one of Examples 1 to 10 8-11 Uses of branched alkanols, including the ethoxylation of the sulfated C-chain alcohol. 8-11 Branched alkanols are used in emulsion polymerization to produce polymer latexes from the following monomers:

[0108] a) Styrene monomers,

[0109] b) (Meth)acrylic acid monomers, and

[0110] c) Optionally, olefinic unsaturated monomers other than these monomers a) and b).

[0111] Example 12. Sulfated ethoxylated C according to Example 11 8-11 Uses of branched alkanols, wherein the polymer latex has a solid content of 35% to 70% by weight.

[0112] Example 13. Use of sulfated ethoxylated C8-C11 branched alkanols according to any one of claims 1 to 10, wherein the sulfated ethoxylated C8-C11 branched alkanols further comprise additional alkoxy groups, preferably propoxy groups.

[0113] Example 14. A method for producing a polymer latex having a solid content of at least 35% by weight by emulsion polymerization in the presence of an anionic surfactant as defined in any one of Examples 1 to 10 and 13.

[0114] Example 15. The method according to Example 14 includes the following steps:

[0115] i) Supply monomers selected from sulfated ethoxylated C during the feed period 8-11 The anionic surfactants and initiators of branched alkanols initiate and continue the polymerization of these monomers during this period.

[0116] ii) The polymerization is sustained after the feed period to allow for post-polymerization, thereby providing an aqueous polymer dispersion.

[0117] iii) Optionally, an anti-settling agent may be added after this post-polymerization to provide an additional aqueous polymer dispersion.

[0118] iv) Optionally, a redox initiator system for monomer chasing is supplied, and

[0119] v) Perform post-processing to provide the polymer latex.

[0120] Example 16. The method according to Example 14 or 15, wherein the polymer latex is produced from the following monomers,

[0121] a) Styrene monomers,

[0122] b) (Meth)acrylic acid monomers, and

[0123] c) Optionally, olefinic unsaturated monomers other than these monomers a) and b).

[0124] Example 17. The method according to Example 16, wherein the polymer latex is produced from the following monomers,

[0125] a) 25% to 50% by weight of the styrene monomer.

[0126] b) 50% to 75% by weight of the (meth)acrylic acid monomer, and

[0127] c) 0% to 20% by weight of the olefinic unsaturated monomer other than these monomers a) and b).

[0128] Example 18. The method according to any one of Examples 15 to 17, wherein a polymer latex having a solid content of 35% to 50% by weight is produced, and comprising steps i), ii), iv), and v).

[0129] Example 19. The method according to any one of Examples 15 to 18, wherein a polymer latex having a solid content of more than 50% and up to 70% by weight is produced, and includes steps i), ii), iii), iv), and v).

[0130] Example 20. A polymer latex having a solid content of at least 35% by weight, the polymer latex being obtained or obtainable by the method according to any one of Examples 14 to 19.

[0131] Example 21. The polymer latex according to Example 20, wherein the polymer latex has a solid content of 35% to 50% by weight and has an average particle size greater than 200 nm, for example greater than 300 nm, as measured by dynamic light scattering.

[0132] Example 22. The polymer latex according to Example 21, wherein the polymer latex has a viscosity of not more than 40 cP, preferably not more than 35 cP, more preferably not more than 30 cP, as measured by a Brookfield rotational viscometer with a #5 rotor at 23°C and 100 rpm.

[0133] Example 23. The polymer latex according to Example 22, wherein the polymer latex has a solid content of more than 50% and up to 70% by weight, and has an average particle size of more than 200 nm as measured by dynamic light scattering.

[0134] Example 24. The polymer latex according to Example 23, wherein the polymer latex has a viscosity of not more than 3000 cP, preferably not more than 2000 cP, more preferably not more than 1800 cP, as measured by a Brookfield rotational viscometer with a #5 rotor at 23°C and 100 rpm.

[0135] Example 25. A polymer latex according to any one of Examples 20 to 24, wherein the polymer latex has a particle size distribution (PDI) of less than 0.2 as measured by dynamic light scattering. Example

[0136] The various aspects of the invention will be illustrated by the following examples, which are provided to illustrate certain aspects of the invention and should not be construed as limiting it.

[0137] Chemicals:

[0138] AIS-C12 / 14: Anionic surfactant, C12 / 14 alkyl sulfate sodium salt.

[0139] AIS-C10-4EO: Anionic surfactant, sulfated ethoxylated C 10 Gelbert's sodium salt, 4 EOs.

[0140] AIS-C12 / 14-30EO: Anionic surfactant, C12 / 14 alkyl ether sulfate sodium salt, 30 EO.

[0141] AIS-C12 / 14-4EO: Anionic surfactant, C12 / 14 alkyl ether sulfate sodium salt, 4 EOs.

[0142] The above chemicals are available commercially from BASF.

[0143] AIS-iso C11-7EO: Anionic surfactant, sodium isoC11 alkyl ether sulfate, 7 EOs (from Clariant's Emulsogen EPA 073).

[0144] Example 1

[0145] In a reaction vessel equipped with an anchor stirrer, 107.9 g of demineralized water was introduced and heated to 85°C. Then, 7.67 g of ammonium persulfate solution (6.3% concentration) was added and stirred at 85°C for 3 min, followed by the addition of monomer emulsion feed and initiator feed as shown in Table 1 over a 4 h time process at 85°C. The reaction was then maintained at 85°C for a 1 h post-polymerization, followed by the addition of 9.11 g of surfactant AIS-C10-4EO in 16.79 g of demineralized water. The system was then cooled to 73°C–75°C, and residual monomer chasing was initiated by parallel initiation of feeds 3 and 4 as shown in Table 1 over 30 min. The resulting system was then cooled to below 40°C, followed by the addition of ammonia for pH adjustment, a mineral oil defoamer, and a CIT / MIT mixture biocide, and then filtered through a 200-mesh sieve.

[0146] The characterization of the obtained polymer latex is shown in Table 1.

[0147] Example 2

[0148] In a reaction vessel equipped with an anchor stirrer, 107.9 g of demineralized water was introduced and heated to 85°C. Then, 7.67 g of ammonium persulfate solution (6.3% concentration) was added and stirred at 85°C for 3 min, followed by the addition of monomer emulsion feed and initiator feed as shown in Table 1 over a 4 h time process at 85°C. The reaction was then maintained at 85°C for a 1 h post-polymerization, followed by the addition of 22.3 g of surfactant AIS-C12 / 14-30EO in 3.6 g of demineralized water. The system was then cooled to 73°C–75°C, and residual monomer chasing was initiated by parallel initiation of feeds 3 and 4 as shown in Table 1 over 30 min. The resulting system was then cooled to below 40°C, followed by the addition of ammonia for pH adjustment, mineral oil defoamer, and a CIT / MIT mixture biocide, and then filtered through a 200-mesh sieve.

[0149] The characterization of the obtained polymer latex is shown in Table 1.

[0150] Example 3

[0151] In a reaction vessel equipped with an anchor stirrer, 107.9 g of demineralized water was introduced and heated to 85°C. Then, 7.67 g of ammonium persulfate solution (6.3% concentration) was added and the mixture was stirred at 85°C for 3 min, followed by the addition of monomer emulsion feed and initiator feed as shown in Table 1. The reaction was stopped during the addition of the monomer emulsion feed because the system in the reactor became too viscous.

[0152] Example 4

[0153] The preparation was carried out using the same method as described in Example 1, except that 22.3 g of surfactant AIS-C12 / 14-4EO was added to 3.6 g of demineralized water after post-polymerization.

[0154] Example 4.1

[0155] The preparation was carried out using the same method as described in Example 4, except that 32.84 g of surfactant AIS-iso C11 7EO was used instead of 13.43 g of surfactant AIS-C10-4EO for the monomer emulsion.

[0156] The characterization of the obtained polymer latex is shown in Table 1.

[0157]

[0158] Table 1. Feed formulations for ultra-high solids content emulsion polymerization and characterization of polymer latex.

[0159] Measured at 100 rpm at 23°C using a Brinell rotational viscometer with a #5 rotor.

[0160] Measured by DLS using Malvern Zetasizer Nano S90

[0161] It can be seen that, compared with emulsion polymerization using other anionic surfactants, emulsion polymerization at ultra-high solids content using the anionic surfactants according to the present invention (Examples 1 and 4) can provide polymer latexes with much lower viscosity, comparable or larger particle size, and narrower particle size distribution. PDI indicates that the large particles of the polymer latex are not due to agglomeration.

[0162] It can also be seen that the anionic surfactants used during emulsion polymerization are crucial for obtaining polymer latexes with low viscosity and high particle size at ultra-high solid content, while the surfactants added as anti-settling agents have little effect on the particle size and viscosity of polymer latexes (Example 3 vs. Example 4).

[0163] Example 5

[0164] In a reaction vessel equipped with an anchor stirrer, 318.91 g of demineralized water was introduced and heated to 85°C. Then, 44.5 g of monomer emulsion as shown in Table 2 and 17.38 g of ammonium persulfate solution (8.3% concentration) were added sequentially, and the system was stirred for 20 min. When the exothermic reaction ended, the residual monomer emulsion feed and initiator feed as shown in Table 2 were added over a 4-h time process at 85°C. The reaction was then maintained at 85°C for a 1-h post-polymerization. Afterward, the system was cooled to 73°C–75°C, and residual monomer chasing was initiated by starting feeds 3 and 4 as shown in Table 2 in parallel over 30 min. Subsequently, the resulting system was cooled to below 40°C, followed by the addition of ammonia for pH adjustment, mineral oil defoamer, and a CIT / MIT mixture biocide, and then filtered through a 200-mesh sieve.

[0165] The characterization of the obtained polymer latex is shown in Table 2.

[0166] Example 6

[0167] In a reaction vessel equipped with an anchor stirrer, 318.91 g of demineralized water was introduced and heated to 85°C. Then, 44.5 g of monomer emulsion as shown in Table 2 and 17.38 g of ammonium persulfate solution (8.3% concentration) were added sequentially, and the system was stirred for 20 min. When the exothermic reaction ended, the residual monomer emulsion feed and initiator feed as shown in Table 2 were added over a 4-h time process at 85°C. The reaction was then maintained at 85°C for a 1-h post-polymerization. Afterward, the system was cooled to 73°C–75°C, and residual monomer chasing was initiated by starting feeds 3 and 4 as shown in Table 2 in parallel over 30 min. Subsequently, the resulting system was cooled to below 40°C, followed by the addition of ammonia for pH adjustment, mineral oil defoamer, and a CIT / MIT mixture biocide, and then filtered through a 200-mesh sieve.

[0168] The characterization of the obtained polymer latex is shown in Table 2.

[0169] Example 7

[0170] In a reaction vessel equipped with an anchor stirrer, 318.91 g of demineralized water was introduced and heated to 85°C. Then, 44.5 g of monomer emulsion as shown in Table 2 and 17.38 g of ammonium persulfate solution (8.3% concentration) were added sequentially, and the system was stirred for 20 min. When the exothermic reaction ended, the residual monomer emulsion feed and initiator feed as shown in Table 2 were added over a 4-h time process at 85°C. The reaction was then maintained at 85°C for a 1-h post-polymerization. Afterward, the system was cooled to 73°C–75°C, and residual monomer chasing was initiated by starting feeds 3 and 4 as shown in Table 2 in parallel over 30 min. Subsequently, the resulting system was cooled to below 40°C, followed by the addition of ammonia for pH adjustment, mineral oil defoamer, and a CIT / MIT mixture biocide, and then filtered through a 200-mesh sieve.

[0171] The characterization of the obtained polymer latex is shown in Table 2.

[0172] Example 8

[0173] In a reaction vessel equipped with an anchor stirrer, 318.91 g of demineralized water was introduced and heated to 85°C. Then, 44.5 g of monomer emulsion as shown in Table 2 and 17.38 g of ammonium persulfate solution (8.3% concentration) were added sequentially, and the system was stirred for 20 min. When the exothermic reaction ended, the residual monomer emulsion feed and initiator feed as shown in Table 2 were added over a 4-h time process at 85°C. The reaction was then maintained at 85°C for a 1-h post-polymerization. Afterward, the system was cooled to 73°C–75°C, and residual monomer chasing was initiated by starting feeds 3 and 4 as shown in Table 2 in parallel over 30 min. Subsequently, the resulting system was cooled to below 40°C, and then ammonia for pH adjustment, mineral oil defoamer, and a CIT / MIT mixture biocide were fed, followed by filtration through a 200-mesh sieve.

[0174] Example 8.1

[0175] The preparation was carried out using the same method as described in Example 8, except that AIS-iso C11-7EO was used instead of AIS-C12 / 14-30EO as the surfactant.

[0176] The characterization of the obtained polymer latex is shown in Table 2.

[0177] Table 2 Feed formulations for high-solids-content emulsion polymerization and characterization of polymer latex

[0178]

[0179] Measured at 100 rpm at 23°C using a Brinell rotational viscometer with a #5 rotor.

[0180] Measured by DLS using Malvern Zetasizer Nano S90

[0181] It accounts for approximately 7.5% of the total monomer emulsion.

[0182] It can be seen that, compared with emulsion polymerization using other anionic surfactants, emulsion polymerization under high solids content conditions using the anionic surfactant according to the present invention (Example 5) can provide polymer latex with much lower viscosity and much larger particle size.

[0183] Example 9

[0184] Repeat the same procedure as in Example 5, except that 11.81 g of monomer emulsion and 17.38 g of ammonium persulfate solution (8.3% concentration) were added sequentially to provide inoculation. The monomer emulsion used for inoculation comprised approximately 2% of the total monomer emulsion.

[0185] The characterization of the obtained polymer latex is shown in Table 3.

[0186] Example 10

[0187] Repeat the same procedure as in Example 5, except that 76.77 g of monomer emulsion and 17.38 g of ammonium persulfate solution (8.3% concentration) were added sequentially. The monomer emulsion used for inoculation comprised approximately 13% of the total monomer emulsion.

[0188] The characterization of the obtained polymer latex is shown in Table 3.

[0189] Table 3 Characterization of polymer latex

[0190]

[0191] Measured at 100 rpm at 23°C using a Brinell rotational viscometer with a #5 rotor.

[0192] Measured by DLS using Malvern Zetasizer Nano S90

[0193] Percentage of monomer emulsions in total monomer emulsions

[0194] For emulsion polymerization at high solids content in the presence of the anionic surfactant according to the invention, polymer latexes with low viscosity and large particle size were obtained by using different doses of monomer emulsions for inoculation.

[0195] Example 11: Measurement of Stability

[0196] The polymer latexes obtained as in Examples 5 through 8 were stirred at 2500 rpm for 30 min. After filtration through a 200-mesh sieve and drying, the coagulants obtained for each sample were observed for comparison. Less coagulant indicates higher stability of the polymer latex. Photographs of the coagulants from each polymer latex are shown in [the table / image / etc.]. Figure 1 It can be clearly seen that, compared with other polymer latexes, the polymer latex according to Example 5 of the present invention produces far less coagulation, indicating a significant improvement in the stability of the polymer latex.

[0197] Although the invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It will be apparent to those skilled in the art that various modifications and variations can be made to the methods and apparatus of the invention without departing from the spirit and scope thereof. Therefore, the invention is intended to include modifications and variations within the scope of the appended claims and their equivalents.

Claims

1. Use of sulfated ethoxylated C 8-11 Use of branched alkanols as anionic surfactants in emulsion polymerization for the production of polymer latices having a solid content of at least 35% by weight.

2. The sulfated ethoxylated C 8-11 Use of branched alkanols, wherein The sulfated ethoxylated C 8-11 The branched alkanol is the sulfated ethoxylated C 8-11 The Guerbet alcohol, in particular the sulfated ethoxylated C8 Guerbet alcohol or C 10 Guerbet alcohol.

3. The sulfated ethoxylated C 8-11 Use of branched alkanols, wherein sulfated ethoxylated C 8-11 branched alkanols are sulfated ethoxylated C 10 gellert alcohol: (I) wherein n denotes the number average ethoxylation degree, preferably in the range of 2 to 8, and M + is a cation, preferably a sodium cation, a lithium cation, a potassium cation or an ammonium cation.

4. The sulfated ethoxylated C 8-11 Use of branched alkanols, wherein The sulfated ethoxylated C 8-11 The branched alkanols have a number average ethoxylization degree in the range of 2 to 8, preferably 2.5 to 6, in particular 3 to 6, preferably 3 to 5, for example 3, 4 or 5.

5. The sulfated ethoxylated C 8-11 Use of branched alkanols, wherein The sulfated ethoxylated C 8-11 The branched alkanol is used in the emulsion polymerization in an amount ranging from 0.5% to 5% based on the total weight of monomers.

6. The sulfated ethoxylated C 8-11 Use of branched alkanols, wherein The sulfated ethoxylated C 8-11 The branched alkanols are used in emulsion polymerization for the production of polymer latexes from the following monomers, a) a styrenic monomer, b) a (meth)acrylic monomer, and c) optionally, an ethylenically unsaturated monomer other than these monomers a) and b).

7. The sulfated ethoxylated C 8-11 Use of branched alkanols, wherein The polymer latex has a solids content of 35% to 70% by weight.

8. The ethoxylated sulfated C8- according to any one of claims 1 to 7 11 Uses of branched alkanols, among which, The sulfated ethoxylated C 8-11 The branched alkanols further comprise additional alkoxylate groups, preferably propoxylate groups.

9. A process for producing a polymer latex having a solids content of at least 35% by weight by emulsion polymerization in the presence of an anionic surfactant as defined in any one of claims 1 to 5.

10. The process according to claim 9, comprising the steps of: i) supplying monomers, selected from the group consisting of sulfated ethoxylated C 8-11 anionic surfactant of branched alkanols, and initiator, during which the polymerization of these monomers starts and proceeds, ii) maintaining the polymerization after the feed period for post polymerization, thereby providing an aqueous polymer dispersion, iii) optionally, adding a anti-settling agent after the post polymerization, to provide a further aqueous polymer dispersion, iv) optionally, a redox initiator system for use in monomer chase, and v) work-up to provide the polymer latex.

11. The method of claim 9 or 10, wherein, The polymer latex is produced from a) a styrenic monomer, b) a (meth)acrylic monomer, and c) optionally, an ethylenically unsaturated monomer other than these monomers a) and b).

12. The method of claim 11, wherein, The polymer latex is produced from a) 25% to 50% by weight of the styrenic monomer, b) 50% to 75% by weight of the (meth)acrylic monomer, and c) 0% to 20% by weight of the ethylenically unsaturated monomer other than these monomers a) and b).

13. The method of any one of claims 10 to 12, wherein, producing a polymer latex having a solids content of 35% to 50% by weight, and wherein the steps i), ii), iv) and v) are included.

14. The method of any one of claims 10 to 12, wherein, producing a polymer latex having a solids content of more than 50% and up to 70% by weight, and wherein the steps i), ii), iii), iv) and v) are included.

15. A polymer latex having a solids content of at least 35% by weight, obtained or obtainable by the process according to any one of claims 9 to 12.

16. The polymer latex of claim 15, wherein, The polymer latex has a solids content of 35% to 50% by weight, and has an average particle size of more than 200 nm, for example more than 300 nm, as measured by dynamic light scattering.

17. The polymer latex of claim 16, wherein, The polymer latex has a viscosity of not more than 40 cP, preferably not more than 35 cP, more preferably not more than 30 cP, as measured by a Brookfield rotational viscometer with a 5# spindle at 23°C at 100 rpm.

18. The polymer latex of claim 15, wherein, The polymer latex has a solids content of more than 50% and up to 70% by weight, and has an average particle size of more than 200 nm, as measured by dynamic light scattering.

19. The polymer latex of claim 18, wherein, The polymer latex has a viscosity of not more than 3000 cP, preferably not more than 2000 cP, more preferably not more than 1800 cP, as measured by a Brookfield rotational viscometer with a 5# spindle at 23°C at 100 rpm.

20. The polymer latex of any one of claims 16-19, wherein, The polymer latex has a particle size distribution (PDI) of less than 0.2, as measured by dynamic light scattering.

Images