Hydrophobic polymer composition and method for preparing the hydrophobic polymer composition - Patents.com

Abstract

Flowable beads of hydrophobic polymers having high chemical and optical purity are provided. The hydrophobic polymers are homopolymers or copolymers of monomers having a water solubility of less than 0.01 g / 100 g H2O. A method for preparing the hydrophobic polymer beads without the use of surfactants or micelle forming agents is also provided.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 63 / 302,694, filed January 25, 2022, the disclosure of which is incorporated herein by reference in its entirety. [Background technology]

[0002] The present disclosure is directed to high purity polymer compositions based on hydrophobic monomers that are water insoluble or have very low water solubility, and methods for preparing the compositions in the form of flowable beads.

[0003] Hydrophobic polymers have traditionally been used as protective coatings in both exterior and interior coating applications where preventing or minimizing water penetration into the protective film and alkali resistance are required. Long-chain branched esters such as vinyl neo-nonanoate, vinyl neo-decanoate, vinyl neo-undecanoate, vinyl neo-dodecanoate, and other hydrophobic monomers with very low water solubility are available and have traditionally been used as monomers or comonomers in polymer compositions to enhance the hydrophobicity of the polymer. Because these monomers can be polymerized with vinyl acetate and acrylic monomers, copolymers of these units have been prepared for applications such as interior and exterior paints, clear and stained wood coatings, corrosion-resistant metal coatings, and structural coatings for cement and concrete. However, the difficulty of copolymerizing or homopolymerizing hydrophobic monomers with very low water solubility is described in U.S. Patent Application Publication No. 2009 / 0264585. As pertaining to this publication, the methods for preparing polymers with such highly hydrophobic monomers are based on emulsion polymerization processes in which the resulting product is an aqueous polymer emulsion containing surfactants and emulsifiers. While such emulsions are useful in latex coating applications, there may be applications in which a hydrophobic polymer composition in solid form with high polymer purity could have significant advantages.

[0004] One technical application area relates to adhesives, coatings, and inks applied to and adhered to plastic substrates, particularly polyolefin plastic substrates such as polyethylene and polypropylene, which are known to be difficult to adhere to due to their difficulty wetting the surface and penetrating the plastic matrix. However, to be effective as adhesives, coatings, or inks on such substrates, it would be advantageous to have the hydrophobic polymer as a relatively pure composition with low or very low water content and free of surfactants and emulsifiers. Having such a composition in the form of a flowable solid, such as beads, would facilitate hygienic handling on an industrial scale. Furthermore, compositions that provide coatings and adhesive layers with high optical purity would be advantageous.

[0005] Therefore, there is a need for high purity hydrophobic polymer compositions in the form of easy to handle solid powders or beads that provide coatings or layers of high optical purity.

[0006] Additionally, there is a need for a process for preparing hydrophobic polymer compositions that produces high purity hydrophobic polymers in high yields and in economically acceptable reaction times. Summary of the Invention

[0007] These and other objects are obtained within the scope of the present disclosure, in a first embodiment, which provides a hydrophobic polymer composition comprising: a homopolymer of a hydrophobic monomer, a copolymer containing at least 30 mole % of a hydrophobic monomer, or a mixture of homopolymers and copolymers; the hydrophobic monomer is selected from the group consisting of vinyl neo-pentanoate, vinyl 2-ethylhexanoate, vinyl neo-nonanoate, vinyl neo-decanoate, vinyl neo-undecanoate, vinyl neo-dodecanoate and hyperbranched vinyl esters of formula (I), H2C=C(R)-OC(O)-C(R1)(R2)(R3) (I) In the formula, R is —H or —CH3, R1, R2, and R3 are each independently a C1 to C10 alkyl group, and the hydrophobic polymer resin The composition is in the form of flowable beads containing at least 95% by weight of homopolymer and / or copolymer.

[0008] In one aspect of the first embodiment, the molecular weight of the homopolymer and / or copolymer is from 50,000 to 300,000 g / mol, and the ratio Mw / Mn of the homopolymer and / or copolymer is from 2.0 to 5.0.

[0009] In another aspect of the first embodiment, the optical clarity of a cast sheet of the hydrophobic polymer composition, as measured by the transmittance of light at a wavelength of 580 nm through a 1.0 mm thick cast sheet of the resin, is 80% or greater according to ASTM D1003.

[0010] In another aspect of the first embodiment, the homopolymer and / or copolymer glass transition temperatures (T g ) is 0 to 100°C.

[0011] In another aspect of the first embodiment, the water solubility of the hydrophobic monomer ranges from completely insoluble to less than 0.01 g / 100 g H2O.

[0012] In another aspect of the first embodiment, the particle size of the flowable beads is between 50 and 500 microns.

[0013] In a further aspect of the first embodiment, the copolymer containing at least 30 mol % of a hydrophobic monomer is selected from the group consisting of styrene, derivatives of styrene, ethylene, propylene, 1,3-butadiene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylamide, optionally substituted C1-C acrylic acid different from the highly branched vinyl ester of formula (I). 30 alkyl esters and optionally substituted C1-C methacrylic acids different from the highly branched vinyl esters of formula (I) 30 It further comprises at least one comonomer selected from the group consisting of alkyl esters.

[0014] In a second embodiment, the present invention provides a method for preparing a hydrophobic polymer composition, the method comprising: charging a pressurizable reactor equipped with a dispersive agitation system with an aqueous solution of an inorganic salt and a polymeric water-soluble material; adding an organic peroxide and / or an azo initiator to the aqueous solution; adding a charge of a hydrophobic monomer or a charge of a mixture of monomers comprising at least 30 mole percent hydrophobic monomer to an aqueous solution to obtain a monomer oil phase / water phase two-phase mixture; agitating the two-phase mixture at a rate to disperse the monomer and organic peroxide and / or azo initiator phase in the aqueous phase in the form of oil droplets having a size of 50 to 1000 microns to form a reaction mixture; pressurizing the reactor with a gas that is chemically inert to the reaction mixture; heating the reaction mixture at a polymerization temperature while maintaining stirring at a dispersing rate that maintains the monomer oil phase in droplet form until polymerization is complete and solid beads are formed; heat-treating the mixture of beads after polymerization at a temperature 5 to 25°C higher than the polymerization temperature for 1 to 10 hours; cooling the mixture of heat-treated polymerized beads to below 50°C to obtain a slurry of homopolymer or copolymer beads and aqueous mother liquor; removing the homopolymer or copolymer beads from the mother liquor; and drying the homopolymer or copolymer beads to obtain free-flowing beads having a particle size of 50 to 500 microns, wherein the water solubility of the hydrophobic monomer ranges from completely insoluble to less than 0.01 g / 100 g water.

[0015] In this second embodiment, the hydrophobic monomer is the same as that described in the first embodiment.

[0016] In a second aspect of the second embodiment, the method further comprises adding at least one sulfur-containing compound selected from the group consisting of alkyl and substituted alkyl thioglycolates, alkyl and substituted alkyl mercaptans, and alkyl and substituted alkyl mercaptopropionates to the charge of hydrophobic monomer or mixture of monomers comprising a hydrophobic monomer.

[0017] In a third aspect of the second embodiment, the method further comprises washing and centrifuging the copolymer beads removed from the mother liquor before drying the copolymer beads.

[0018] In another aspect of the second embodiment, the conversion of monomer to polymer or copolymer (monomer conversion) is at least 99%. In another aspect of the second embodiment, the polymeric water-soluble material is hydroxyethyl cellulose, poly(meth)

[0019] The content of the water-soluble polymeric material in the aqueous solution is 0.01 to 0.1 part per 100 parts of water, and is selected from the group consisting of alkali metal salts of acrylic acid, ammonium salts of poly(meth)acrylic acid, polyvinyl alcohol, and polyvinylpyrrolidone.

[0020] In another aspect of the second embodiment, the inorganic salt of the aqueous solution is an alkali metal sulfate, alkali metal nitrate, alkali metal phosphate, alkali metal carbonate, alkali metal bicarbonate, or alkali metal halide, and the content of the inorganic salt in the aqueous solution is 0.1 to 0.5 parts per 100 parts of water.

[0021] In another aspect of the second embodiment, the organic peroxide is selected from the group consisting of dibenzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, t-hexyl peroxypivalate, t-butyl peroxypivalate, di(3,5,5-trimethylhexanoyl)peroxide, di(4-methylbenzoyl)peroxide, di(3-methylbenzoyl)peroxide, benzoyl(3-methylbenzoyl)peroxide, t-hexylperoxy-2-ethylhexanoate, 1 ,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, tert-amylperoxypivalate, tert-amylperoxyisobutyrate, tert-amylperoxy-2-ethylhexanoate, and t-butylperoxybenzoate, and the content of the organic peroxide is 0.1 to 2.0 parts per 100 parts of the total monomers.

[0022] In another aspect of the second embodiment, the polymerization temperature is 50°C to 95°C.

[0023] In another aspect of the second embodiment, the content of the hydrophobic monomer charge or the charge of a mixture of monomers containing a hydrophobic monomer is 25 to 100 parts per 100 parts of water.

[0024] In a further aspect of the second embodiment, a mixture of monomers including a hydrophobic monomer is charged, the mixture being selected from the group consisting of styrene, ethylene, propylene, 1,3-butadiene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylamide, acrylic acid, optionally substituted C1-C 30 Optionally substituted C1-C alkyl esters and methacrylic acids 30 The polymer further comprises at least one monomer selected from the group consisting of alkyl esters.

[0025] In another aspect of the second embodiment, the reaction mixture does not include a surfactant or micelle-forming agent.

[0026] In another aspect of the second embodiment, a mixture of monomers is charged that includes a hydrophobic monomer, and the mixture does not include a cross-linking monomer.

[0027] The foregoing paragraphs have been provided by way of general introduction and are not intended to limit the scope of the claims that follow. The described embodiments, together with further advantages, will be best understood by reference to the following detailed description taken in conjunction with the accompanying drawings, in which: [Brief explanation of the drawings]

[0028] [Figure 1] FIG. 1 is a schematic flow chart of a polymerization method of the present invention. [Figure 2] FIG. 1 is a diagram illustrating an adhesion test method used in the evaluation of examples of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0029] As used herein, words such as "a" and "an" mean "one or more." Phrases such as "selected from the group consisting of," "selected from," and the like include mixtures of the specified materials. Terms such as "comprising" are open terms meaning "including at least," unless otherwise specified.

[0030] When a numerical boundary or range is described, the endpoints are included. Also, all values ​​and subranges within the numerical boundary or range are specifically included, as if expressly written out. When the term "about" is applied to a numerical value, it refers to a value up to 5% greater than that value and / or up to 5% less than that value.

[0031] As used herein, the term "(meth)" in (meth)acrylate refers to the acrylate and / or the corresponding methacrylate, e.g., methyl (meth)acrylate refers to both methyl acrylate and methyl methacrylate. As used herein, the term "copolymer" refers to a polymer polymerized from at least two monomers, and includes terpolymers, tetrapolymers, etc.

[0032] As used herein, the term "polymerization conditions sufficient to polymerize the monomers of the monomer composition" means that the conditions are sufficient to achieve conversion of the monomers to a polymer or copolymer, where monomer conversion can be expressed as a percentage, e.g., at least 90 percent, at least 95 percent, at least 98 percent, or at least 99 percent, as specified. Monomer conversion can be determined as described in the Examples of the present disclosure.

[0033] The hydrophobic polymer compositions of the present disclosure are based on homopolymers of hydrophobic monomers or copolymers containing at least 30% by weight of a hydrophobic monomer or a mixture of hydrophobic monomers. According to the present disclosure, hydrophobic monomers are defined as monomers that are completely insoluble in water or may have a solubility in water of less than 0.01 g / 100 g deionized HO at 20° C.

[0034] Although any monomer having a water solubility ranging from insoluble to less than 0.01 g / 100 g HO may be suitable as the hydrophobic monomer according to the present disclosure, preferred hydrophobic monomers are selected from the group consisting of vinyl neo-pentanoate, vinyl 2-ethylhexanoate, vinyl neo-nonanoate, vinyl neo-decanoate, vinyl neo-undecanoate, vinyl neo-dodecanoate and hyperbranched vinyl esters of formula (I): H2C=C(R)-OC(O)-C(R1)(R2)(R3) (I) In the formula, R is —H or —CH3, and R1, R2, and R3 are each independently a C1 to C10 alkyl group.

[0035] These monomers are well known and many are commercially available. For example, vinyl neo-pentanoate is available as vinyl pivalate from Handan Huajun Chemicals Co., Ltd. Vinyl 2-ethylhexanoate is available from Chemoxy International Ltd. Vinyl neo-nonanoate, vinyl neo-decanoate, and vinyl neo-undecanoate are available from Hexion under the trade names VeoVa9, VeoVa10, and VeoVa11, respectively.

[0036] While the homopolymers of the present disclosure are derived from one of the hydrophobic monomers identified above, copolymers may contain at least 30% by weight, preferably 40% by weight or more, and most preferably 50% by weight or more of one or more of the hydrophobic monomers listed above, as long as the hydrophobic properties are not adversely affected. The copolymers may also contain other hydrophobic monomers such as vinyl laurate, vinyl stearate, (C9-C 30 ) alkyl group, such as vinyl alkyl or aryl ethers of (meth-)acrylic acid (C6-C 30 ) alkyl esters such as hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, isobornyl (meth)acrylate, isooctyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, dodecyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, benzyl (meth)acrylate, lauryl (meth)acrylate, oleyl (meth)acrylate, palmityl (meth)acrylate, and stearyl (meth)acrylate; and comonomers including one or more of unsaturated vinyl esters of (meth)acrylic acid, such as those derived from fatty acids and fatty alcohols.

[0037] Other comonomers included are optionally substituted C1-C styrene, derivatives of styrene, ethylene, propylene, 1,3-butadiene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylamide, acrylic acid.30 Optionally substituted C1-C alkyl esters and methacrylic acids 30 alkyl esters, and the optional substituents may be one or more selected from the group consisting of halide, cyano, nitro, C 1~10 They may include alkoxy groups, optionally substituted phenyl groups and optionally substituted benzyl or phenethyl groups. Derivatives of styrene include alkyl styrenes such as methyl or ethyl styrene and halogen substituted styrenes.

[0038] Any mixture of these monomers can be included in the hydrophobic copolymer of the present invention, and one skilled in the art can design the copolymer monomer composition based on the performance characteristics selected for the hydrophobic copolymer of interest.

[0039] Any crosslinking agent suitable for radical polymerization may be applicable, but preferred examples include divinylbenzene, allyl methacrylate, and 1,6-hexanediol dimethacrylate. The crosslinking agent is preferably used in an amount of 0 to 2.0 parts, more preferably 0 to 0.5 parts, per 100 parts of monomer or comonomer. The crosslinking agent may be included in the mixture of monomers to be polymerized, but in a preferred embodiment, no crosslinking monomer is present.

[0040] The homopolymers or copolymers according to the present invention may have a molecular weight of 50,000 to 350,000 g / mol, preferably 100,000 to 300,000 g / mol, and most preferably 125,000 to 275,000. Molecular weight can be determined by standard gel permeation chromatography (GPC) methods as described in the Examples. Molecular weight can be controlled by appropriate adaptation of the polymerization methods described later in this disclosure.

[0041] The polydispersity index (Mw / Mn) of the homopolymer or copolymer of the present invention, determined by GPC, may be 2.0 to 5.0, preferably 2.0 to 4.0, and most preferably 2.0 to 3.0, and is determined depending on the monomer or polymerized monomers of the present invention and the polymerization method.

[0042] Depending on the monomer composition of the hydrophobic homopolymer or hydrophobic copolymer, the glass transition temperature (Tg) can be 0 to 100° C. Those skilled in the art can derive an appropriate hydrophobic polymer composition to have a desired Tg value.

[0043] The hydrophobic polymer composition according to the present disclosure is provided in the form of a solid powder or beads containing a homopolymer, copolymer, or mixture thereof, and the content is at least 95%, preferably at least 96%, and most preferably at least 97% by weight of the powder or beads. The physical form and high weight percentage are obtained as a result of the polymerization method used to prepare the composition, as described below. The method can produce homopolymers or copolymers in yields (monomer conversion) of 97%, preferably 98%, and most preferably 99% or greater, without the use of surfactants or micelle-forming agents.

[0044] When the composition of the present disclosure contains a mixture of hydrophobic homopolymers and hydrophobic copolymers, the mixture may be a physical blend of the homopolymers and copolymers produced separately. Any plurality of homopolymers and copolymers may be physically blended to obtain a composition having selected desired properties.

[0045] Alternatively, the mixture can be prepared by first preparing the homopolymer in a reactor and then preparing the copolymer in the presence of the homopolymer in the same reactor.

[0046] The hydrophobic polymer composition according to the present disclosure may be provided in the form of flowable beads having a particle size of 50 to 500 microns, preferably 100 to 400 microns, and most preferably 150 to 300 microns. According to the present invention, the term "flowable" means that the resin composition beads can be easily transferred by gravity or a conveyor from one container to another or from a container to a hopper of a device without clumping or clogging problems.

[0047] Due to the high weight percent loading and the absence of contaminants such as surfactants and micelle-forming agents, the hydrophobic polymer compositions of the present disclosure provide coatings or cast layers with high optical clarity. For example, a 1.0 mm thick cast sheet of the polymer composition may have an optical clarity exhibiting a transmittance of 80% or greater, preferably 85% or greater, and most preferably 90% or greater at 580 nm per ASTM D1003. Thus, the hydrophobic polymer compositions may be well suited as adhesives or coatings for polyethylene or polypropylene structures where optical clarity is required.

[0048] In a second embodiment, the present disclosure provides a method for preparing a hydrophobic polymer composition having the composition and properties described above, the method comprising: charging a pressurizable reactor equipped with a dispersive agitation system with an aqueous solution of an inorganic salt and a polymeric water-soluble material; adding an organic peroxide and / or an azo initiator to the aqueous solution; adding a charge of a hydrophobic monomer or a charge of a mixture of monomers comprising at least 30 wt. % hydrophobic monomer to an aqueous solution to obtain a monomer oil phase / water phase two-phase mixture; agitating the two-phase mixture at a rate to disperse the monomer and organic peroxide and / or azo initiator phase in the aqueous phase in the form of oil droplets having a size of 50 to 1000 microns to form a reaction mixture; pressurizing the reactor with a gas that is chemically inert to the reaction mixture; heating the reaction mixture at a polymerization temperature while maintaining stirring at a dispersing rate that maintains the monomer oil phase in droplet form until polymerization is complete and solid beads are formed; heat-treating the mixture of beads after polymerization at a temperature 5 to 25°C higher than the polymerization temperature for 1 to 10 hours; cooling the mixture of heat-treated polymerized beads to below 50°C to obtain a slurry of homopolymer or copolymer beads and aqueous mother liquor; removing the homopolymer or copolymer beads from the mother liquor; and drying the homopolymer or copolymer beads to obtain free-flowing beads having a particle size of 50 to 500 microns.

[0049] As defined above, the water solubility of the hydrophobic monomers ranges from completely insoluble to less than 0.01 g / 100 g water.

[0050] The hydrophobic monomers and comonomers used in this method are the same as those described above for the hydrophobic homopolymer or copolymer of the first embodiment.

[0051] The reactor used in the disclosed process can be any conventional reactor with a dispersing agitator or mechanical system capable of dispersing and maintaining the hydrophobic monomer phase containing the organic peroxide and / or azo initiator at a droplet size of 50 to 1000 microns. Because the polymerization reaction is carried out under pressure, the reactor's rated operating pressure should be about 20 psi (1.38 bar) to about 100 psi (6.9 bar) at a temperature range of 50°C to 100°C. Reactors with rated pressures higher than this range may also be used.

[0052] Because the processes of the present disclosure are carried out in an aqueous medium, the materials of construction of the reactor can be any of those conventionally used in polymerization chemistry.

[0053] The gas used to pressurize the reactor can be any gas that is chemically inert to the reaction mixture components and may be nitrogen, carbon dioxide or argon.

[0054] The water comprising the aqueous continuous phase may be filtered water, and in a preferred embodiment, the water is deionized and filtered. The water may be treated to remove biological contaminants.

[0055] The initial aqueous solution charged to the reactor contains 0.1 to 0.5 parts of a water-soluble inorganic salt. While any water-soluble inorganic salt based on alkali metals, alkaline earth metals, and transition metals that does not interfere with the polymerization reaction can be used, preferred inorganic salts are selected from the group consisting of alkali metal sulfates, alkali metal nitrates, alkali metal phosphates, alkali metal carbonates, alkali metal bicarbonates, and alkali metal halides. Preferably, the alkali metal is sodium or potassium.

[0056] The initial aqueous solution charged to the reactor also contains a polymeric water-soluble material preferably selected from the group consisting of hydroxyethyl cellulose, alkali metal salts of poly(meth)acrylic acid, ammonium salts of poly(meth)acrylic acid, polyvinyl alcohol, and polyvinylpyrrolidone. Mixtures of these materials may also be used.

[0057] The total content of the water-soluble polymeric materials in the aqueous solution is 0.01 to 0.1 part per 100 parts of water.

[0058] The monomer composition is then charged, and the monomer charge may be 25 to 100 parts per 100 parts of the aqueous solution in the reactor.

[0059] According to the method of the present invention, an organic peroxide and / or azo initiator is added to an aqueous mixture of hydrophobic monomers so that it dissolves within the dispersed monomer oil phase droplets. The organic peroxide may be any peroxide soluble in the monomer phase, and in a preferred embodiment, the organic peroxide is selected from the group consisting of dibenzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, t-hexyl peroxypivalate, t-butyl peroxypivalate, di(3,5,5-trimethylhexanoyl) peroxide, di(4-methylbenzoyl) peroxide, di(3-methylbenzoyl) peroxide, benzoyl(3-methylbenzoyl) peroxide, t-hexyl peroxypivalate, t-butyl peroxypivalate, di(3,5,5-trimethylhexanoyl) peroxide, di(4-methylbenzoyl) peroxide, di(3-methylbenzoyl) peroxide, benzoyl(3-methylbenzoyl) peroxide, t-hexyl peroxypivalate, di(3,5,5-trimethylhexanoyl) peroxide, di(4-methylbenzoyl) peroxide, di(3-methylbenzoyl) peroxide, benzoyl ... The peroxide may be one or more selected from the group consisting of tert-butyl peroxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, tert-amyl peroxypivalate, tert-amyl peroxyisobutyrate, tert-amyl peroxy-2-ethylhexanoate, and t-butyl peroxybenzoate.

[0060] The content of the organic peroxide may be in the range of 0.1 to 2.0 parts, preferably 0.50 to 2.0 parts, and most preferably 1.0 to 2.0 parts, based on 100 parts of the monomer composition charged.

[0061] The nitrogen-based radical azo initiator may be used alone or in combination with a peroxide initiator. Preferred examples include 2,2'-azobisisobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(1-acetoxy-1-phenylethane), and dimethyl 2,2'-azobisisobutyrate. The content of the nitrogen-based radical initiator may be 0 to 2.0 parts, more preferably 0 to 0.5 parts, per 100 parts of the total monomers. Most preferably, no azo initiator is used.

[0062] The polymerization temperature depends on the initiation temperature of the peroxide and / or azo initiator, i.e., the temperature at which the peroxide or azo bond is cleaved, resulting in free radical initiation of polymerization. Generally, the polymerization temperature can be from about 50°C to about 95°C, although the temperature can be outside this range depending on the combination of monomers and organic peroxide or azo initiator selected. Those skilled in the art can determine the optimal polymerization temperature through routine experimentation.

[0063] The inventors have discovered that the molecular weight and polydispersity of the resulting polymer can be controlled through the addition of a sulfur-containing agent selected from the group consisting of alkyl and substituted alkyl thioglycolates, alkyl and substituted alkyl mercaptans, and alkyl and substituted alkyl mercaptopropionates. Specific examples of sulfur-containing agents include methyl thioglycolate, ethyl thioglycolate, butyl thioglycolate, octyl thioglycolate, 2-ethylhexyl thioglycolate, isooctyl thioglycolate, 3-methoxybutyl thioglycolate, ethylene bis(thioglycolate), polyethylene bis(thioglycolate), 1,4-butanediol bis(thioglycolate), 1,6-hexanediol bis(thioglycolate), pentaerythritol, and the like. tetrakis(thioglycolate), stearyl thioglycolate, methyl mercaptan, ethyl mercaptan, butyl mercaptan, cyclohexyl mercaptan, 2-ethylhexyl mercaptan, n-octyl mercaptan, t-nonyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, t-tetradecyl mercaptan, t-hexadecyl mercaptan, adamantyl mercaptan, 1-p-menthen-8-thiol, p-mentha-8- Thiol-3-one, stearyl mercaptan, benzyl mercaptan, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, butyl 3-mercaptopropionate, octyl 3-mercaptopropionate, 2-ethylhexyl 3-mercaptopropionate, isooctyl 3-mercaptopropionate, 3-methoxybutyl 3-mercaptopropionate, tridecyl 3-mercaptopropionate, ethylene glycol bis(3-methylpropionyl) Examples of suitable mercaptopropionates include, but are not limited to, polyethylene glycol bis(3-mercaptopropionate), 1,4-butanediol bis(3-mercaptopropionate), 1,6-hexanediol bis(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), and stearyl 3-mercaptopropionate.

[0064] In a preferred embodiment, the sulfur-containing agent is methyl thioglycolate, ethyl thioglycolate, butyl thioglycolate, octyl thioglycolate, 2-ethylhexyl thioglycolate, isooctyl thioglycolate, 3-methoxybutyl thioglycolate, ethylene bis(thioglycolate), polyethylene bis(thioglycolate), 1,4-butanediol bis(thioglycolate), 1,6-hexanediol bis(thioglycolate), pentaerythritol tetrakis(thioglycolate), stearyl thioglycolate, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, butyl 3-mercaptopropionate, octyl 3-mercaptopropionate, or methyl 3-mercaptopropionate. mercaptopropionate, 2-ethylhexyl 3-mercaptopropionate, isooctyl 3-mercaptopropionate, 3-methoxybutyl 3-mercaptopropionate, tridecyl 3-mercaptopropionate, ethylene glycol bis(3-mercaptopropionate), polyethylene glycol bis(3-mercaptopropionate), 1,4-butanediol bis(3-mercaptopropionate), 1,6-hexanediol bis(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), stearyl 3-mercaptopropionate.

[0065] Mixtures of these sulfur-containing compounds may also be used.

[0066] Preferably, surfactants and micelle formers are not added to the reactor and the presence of such materials in the polymerization reactor should be avoided.

[0067] According to the disclosed method, once all components constituting the polymerization reaction medium are charged into the reactor, the system can be purged with an inert gas and then pressurized. The stirring system, which may be running at a constant speed to mix the components during charging, is then increased to a sufficient agitation level to form droplets of a hydrophobic oil phase containing an organic peroxide and / or azo initiator and a sulfur-containing compound. The temperature is raised to the polymerization temperature and maintained until polymerization within the oil phase droplets is complete and the oil droplets are converted into solid beads. Depending on the monomer(s), peroxide and / or azo initiator content, and polymerization temperature used, polymerization can take from 0.5 to 10 hours.

[0068] Once solid beads have formed and polymerization is substantially complete, the aqueous mixture of beads is heat treated by raising the temperature to a treatment temperature 5 to 25°C above the polymerization temperature and maintaining that temperature for 1 to 10 hours.

[0069] At the end of the heat treatment, the beads have hardened into solid particles with a diameter of 50 to 500 microns. The beads are separated from the reaction mother liquor by any method commonly used in the art. For example, the bead slurry can be decanted, washed, and then transferred to a centrifuge for recovery. Alternatively, the beads can be filtered.

[0070] The recovered beads may be reslurried in water and recovered by centrifugation or filtration one or more times to remove any remaining mother liquor before drying.

[0071] The beads are then dried by conventional methods such as a hot air drying oven or a fluidized bed dryer at temperatures ranging from room temperature to 20° C. below the Tg of the hydrophobic polymer.

[0072] FIG. 1 shows a schematic diagram of the steps of the method described above, including images of the resulting beads.

[0073] The disclosed method is broadly applicable to the preparation of homopolymers and copolymers of the hydrophobic monomers disclosed herein, as shown in Tables 1 and 2. The method can be designed to provide hydrophobic polymers with a wide range of physical properties in the form of flowable beads with high weight percentages of polymer and high light transmittance.

[0074] The above description is presented to enable any person skilled in the art to make and use embodiments and aspects of the present disclosure, and is provided in the context of a particular application and its requirements. Various modifications to the preferred embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the present disclosure. Thus, the present disclosure is not intended to be limited to the embodiments shown, but is to be accorded the widest scope consistent with the principles and features disclosed herein. In this regard, any particular embodiment within the present disclosure may not exhibit all of the advantages of the present disclosure, considered broadly. [Example]

[0075] Molecular weight determination Molecular weights were obtained by standard gel permeation chromatography (GPC). GPC measurements were performed on a Tosoh HLC-8320 GPC using three columns in series (two TSKgel Super HZM-M followed by an HZ2000). Measurements were performed by RI at a polymer concentration of 0.2% in THF at a flow rate of 0.35 mL / min at 40°C.

[0076] Example 1 Polymerization stage: A reactor was charged with 200 parts water, 0.5 parts sodium sulfate, and 0.03 parts poly(methacrylic acid) potassium salt as a suspension stabilizer. Next, 1 part benzoyl peroxide as an initiator (BPO), and a monomer mixture containing 75 parts vinyl neodecanoate (VV-10), 20 parts isobornyl methacrylate (IBOMA), and 5 parts lauryl methacrylate (LMA) were added to the reactor. After addition was complete, the water and monomer mixture were mechanically stirred at 1000 rpm to disperse the monomer mixture in the water and form monomer droplets 100-500 microns in diameter.

[0077] After the reactor was purged with nitrogen at a pressure of 45 psi, the reactor mixture was heated to a reaction temperature of 85°C and polymerization was continued for 45 minutes with stirring. The polymerization competition was judged from the temperature peak accompanied by a pressure drop.

[0078] Heat treatment stage: After polymerization was completed, the reactor contents were held at 95° C. for 60 minutes. After the heat treatment stage was completed, the reaction mixture was cooled to 40° C. and the reactor contents were discharged under pressure into a slurry tank. The polymerization yield (monomer conversion) was determined to be 99.5%.

[0079] Dehydration and drying: The wet product was decanted, centrifuged, washed with water, and dried for 2 hours at 40° C. The final product was dry beads with a diameter of 100-300 microns.

[0080] Typical physical properties of the final product are listed below. [Table 1]

[0081] Example 2 A sample was obtained in the same manner as in Example 1, except that 1 part of lauryl peroxide (LPO) was used instead of 1 part of benzoyl peroxide. The polymerization yield (monomer conversion) was 99.4%, and the weight-average molecular weight of the obtained sample was 260,000 as measured by GPC.

[0082] Comparative Example 1 A sample was obtained in the same manner as in Example 1, except that 0.4 parts of azobisisobutyronitrile (AIBN) was used instead of 1 part of benzoyl peroxide. The polymerization yield (monomer conversion) was 97.0%, and the weight-average molecular weight of the obtained sample was 150,000 as measured by GPC.

[0083] Example 3 A sample was obtained in the same manner as in Example 1, except that 0.6 parts of 2-ethylhexyl thioglycolate (2-EHTG) as a chain transfer agent was added together with the monomer mixture. The polymerization yield (monomer conversion) was 99.3%, and the weight-average molecular weight of the obtained sample was 85,000 as measured by GPC.

[0084] Comparative Example 2 A sample was obtained in the same manner as in Example 3, except that 0.6 parts of n-octyl mercaptan (NOM) was used instead of 0.6 parts of 2-ethylhexyl thioglycolate (2-EHTG). The polymerization yield (monomer conversion) was 96.2%, and the weight-average molecular weight of the obtained sample was 110,000 as measured by GPC.

[0085] Table 1 provides a summary of these examples. [Table 2]

[0086] The hydrophobic polymers listed in Table 2 below were prepared and analyzed using the same method as above. Light transmittance data was obtained by dissolving the hydrophobic resin composition in toluene at 40-50% solids. Films of the solution were prepared using an appropriately sized stretcher rod to obtain a 1 mm dry film upon evaporation of the toluene. The dry film was cut to the appropriate size and the light transmittance at 580 nm was measured according to ASTM D1003.

[0087] The samples were also evaluated for adhesion to polypropylene per ASTM D3359, as shown in Figure 2. Samples were prepared as a 40% resin solution in toluene, with or without plasticizer. The solution was drawn onto a polypropylene substrate and allowed to dry. Tape testing per ASTM D3359 was then performed, with the results shown in Table 2.

[0088] Monomer conversion is defined as the conversion of monomer to polymer. % = weight of polymer / (weight of monomer + weight of polymer). Monomer conversion is determined by gas chromatography.

[0089] The dispersity of a polymer is defined as the ratio Mw / Mn and is determined by GPC analysis.

[0090] The plasticizer used was Hexamoll® DINCH, 1,2-cyclohexanedicarboxylic acid diisononyl ester, which was tested to reflect the possibilities of practical application, and any common plasticizer known to those skilled in the art of adhesives can be used. [Table 3]

[0091] The abbreviations in the table are defined as follows: VV-9: Vinyl Neono Nano Art VV-10: Vinyl neodecanoate IBOMA: Isobornyl methacrylate LMA: Lauryl methacrylate 2-EHA: 2-ethylhexyl acrylate MMA: methyl methacrylate BA: butyl acrylate t-BMA: tert-butyl methacrylate 2-EHTG: Ethylhexyl thioglycolate NOM: n-octyl mercaptan AIBN: Azobisisobutyronitrile LPO: Lauryl peroxide BPO: Benzoyl peroxide

[0092] As shown in Table 2, all homopolymers and copolymers according to the present disclosure exhibit light transmittance greater than 80% by ASTM D1003 at 580 nm and a polymer weight percentage of 99.0% or greater. Note that Examples 20-23 are not hydrophobic copolymers according to the present disclosure due to low light transmittance and / or low monomer conversion.

[0093] Adhesion performance according to ASTM D3359 is a function of the hydrophobic monomer content, the comonomer and comonomer content used, and the molecular weight of the polymer. As shown in Examples 1 and 11, when the hydrophobic monomer content is high, adhesion to polypropylene is rated at its highest, regardless of the molecular weight of the polymer. When a less hydrophobic comonomer is included, the addition of a plasticizer improves adhesion to polypropylene.

Claims

1. 1. A hydrophobic polymer composition comprising: a homopolymer of a hydrophobic monomer, a copolymer containing at least 30% by weight of said hydrophobic monomer, or a mixture of said homopolymer and said copolymer, the hydrophobic monomer is selected from the group consisting of vinyl neo-pentanoate, vinyl 2-ethylhexanoate, vinyl neo-nonanoate, vinyl neo-decanoate, vinyl neo-undecanoate, vinyl neo-dodecanoate and hyperbranched vinyl esters of formula (I), H ２ C=C(R)-O-C(O)-C(R １ )(R ２ )(R ３ ) (I) During the ceremony, R is -H or -CH ３ and R １ , R ２ and R ３ are each independently a C1 to C10 alkyl group, A hydrophobic polymer composition in the form of flowable beads containing at least 95% by weight of said homopolymer and / or copolymer.

2. 2. The hydrophobic polymer composition of claim 1, wherein the molecular weight of said homopolymer and / or said copolymer is from 50,000 to 300,000 g / mol and the ratio of Mw / Mn is from 2.0 to 5.

0.

3. 3. The hydrophobic polymer composition of claim 1 or 2, wherein the optical clarity of a 1.0 mm thick cast sheet of said resin, as measured by the transmittance of light at a wavelength of 580 nm, is 80% or greater according to ASTM D1003.

4. The glass transition temperature (T ｇ 3. The hydrophobic polymer composition according to claim 1, wherein the temperature is 0 to 100°C.

5. The water solubility of the hydrophobic monomer ranges from completely insoluble to 0.01 g / 100 g H ２ 3. The hydrophobic polymer composition of claim 1, wherein the molecular weight of the polymer is less than 0.

6. The copolymer contains at least 30% by weight of the hydrophobic monomer, and the copolymer is selected from the group consisting of styrene, derivatives of styrene, ethylene, propylene, 1,3-butadiene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylamide, and optionally substituted C １ ~C ３０ Alkyl esters and optionally substituted C methacrylic acid １ ~C ３０ 3. The hydrophobic polymer composition of claim 1 or 2, further comprising at least one comonomer selected from the group consisting of alkyl esters.

7. 3. The hydrophobic polymer composition of claim 1 or 2, wherein the flowable beads have a particle size of 50 to 500 microns.

8. 3. The hydrophobic polymer composition of claim 1 or 2, comprising said homopolymer of a hydrophobic monomer.

9. 3. The hydrophobic polymer composition of claim 1, comprising said copolymer, said copolymer containing a mixture of said hydrophobic monomers.

10. 3. A method for preparing the hydrophobic polymer composition of claim 1 or 2, comprising: charging a pressurizable reactor equipped with a dispersive agitation system with an aqueous solution of an inorganic salt and a polymeric water-soluble material; adding an organic peroxide and / or an azo initiator to the aqueous solution; adding a charge of said hydrophobic monomer or a charge of a mixture of monomers comprising at least 30 wt.% of said hydrophobic monomer to said aqueous solution to obtain a monomer oil phase / water phase two-phase mixture; agitating the two-phase mixture at a rate to disperse the monomer and organic peroxide phase in the aqueous phase in the form of oil droplets of 50 to 1000 microns in size to form a reaction mixture; pressurizing the reactor with a gas that is chemically inert to the reaction mixture; heating the reaction mixture at a polymerization temperature while maintaining the stirring at a dispersing rate that maintains the monomer oil phase in the form of droplets until polymerization is complete and solid beads are formed; heat-treating the mixture of beads after the polymerization is completed at a temperature 5 to 25°C higher than the polymerization temperature for 1 to 10 hours; cooling the heat-treated mixture of polymerized beads to below 50°C to obtain a slurry of homopolymer or copolymer beads and aqueous mother liquor; removing the homopolymer or copolymer beads from the mother liquor; drying the homopolymer or copolymer beads to obtain free-flowing beads having a particle size of 50 to 500 microns; A method for preparing a hydrophobic polymer composition, wherein the water solubility of said hydrophobic monomer ranges from completely insoluble to less than 0.01 g / 100 g water.

11. 11. The method of claim 10, further comprising adding at least one sulfur-containing compound selected from the group consisting of alkyl and substituted alkyl thioglycolates, alkyl and substituted alkyl mercaptans, and alkyl and substituted alkyl mercaptopropionates to said charge of said hydrophobic monomer or mixture of monomers comprising said hydrophobic monomer.

12. The at least one sulfur-containing compound is selected from the group consisting of methyl thioglycolate, ethyl thioglycolate, butyl thioglycolate, octyl thioglycolate, 2-ethylhexyl thioglycolate, isooctyl thioglycolate, 3-methoxybutyl thioglycolate, ethylene bis(thioglycolate), polyethylene bis(thioglycolate), 1,4-butanediol bis(thioglycolate), 1,6-hexanediol bis(thioglycolate), pentaerythritol tetrakis(thioglycolate), stearyl thioglycolate, methyl 3-mercaptopropionate, ethyl 3-mercaptopropionate, butyl 3-mercaptopropionate, and octyl 3-mercaptopropionate. , 2-ethylhexyl 3-mercaptopropionate, isooctyl 3-mercaptopropionate, 3-methoxybutyl 3-mercaptopropionate, tridecyl 3-mercaptopropionate, ethylene glycol bis(3-mercaptopropionate), polyethylene glycol bis(3-mercaptopropionate), 1,4-butanediol bis(3-mercaptopropionate), 1,6-hexanediol bis(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), pentaerythritol tetrakis(3-mercaptopropionate), and stearyl 3-mercaptopropionate.

13. 11. The process of claim 10, wherein the conversion of monomer to polymer or copolymer is at least 99%.

14. 11. The method of claim 10, further comprising washing and centrifuging the copolymer beads removed from the mother liquor before drying the copolymer beads.

15. 11. The method of claim 10, wherein the polymeric water-soluble material is at least one selected from the group consisting of hydroxyethyl cellulose, alkali metal salts of poly(meth)acrylic acid, ammonium salts of poly(meth)acrylic acid, polyvinyl alcohol, and polyvinylpyrrolidone.

16. The method according to claim 10, wherein the content of the water-soluble polymeric material in the aqueous solution is 0.01 to 0.1 parts per 100 parts of water.

17. 11. The method of claim 10, wherein the inorganic salt of the aqueous solution is an inorganic salt of an alkali metal, alkaline earth metal, or transition metal.

18. 11. The method of claim 10, wherein the inorganic salt of the aqueous solution is an alkali metal sulfate, alkali metal nitrate, alkali metal phosphate, alkali metal carbonate, alkali metal bicarbonate, or alkali metal halide.

19. The method according to claim 10, wherein the content of the inorganic salt in the aqueous solution is 0.1 to 0.5 parts per 100 parts of water.

20. The organic peroxides used include dibenzoyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, dilauroyl peroxide, t-hexyl peroxypivalate, t-butyl peroxypivalate, di(3,5,5-trimethylhexanoyl)peroxide, di(4-methylbenzoyl)peroxide, di(3-methylbenzoyl)peroxide, benzoyl(3-methylbenzoyl)peroxide, t-hexylperoxy-2-ethylhexanoyl 11. The method of claim 10, wherein the peroxyl group is selected from the group consisting of 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylperoxy-2-ethylhexanoate, 2,5-dimethyl-2,5-di(2-ethylhexanoylperoxy)hexane, tert-amylperoxypivalate, tert-amylperoxyisobutyrate, tert-amylperoxy-2-ethylhexanoate, and t-butylperoxybenzoate.

21. The method according to claim 10, wherein the content of the organic peroxide is 0.1 to 2.0 parts per 100 parts of the total monomers.

22. 11. The process of claim 10, wherein the azo initiator is used and is selected from the group consisting of 2,2'-azobis-isobutyronitrile, 2,2'-azobis-2-methylbutyronitrile, 2,2'-azobis-2,4-dimethylvaleronitrile, 1,1'-azobis(1-acetoxy-1-phenylethane) and dimethyl 2,2'-azobisisobutyrate.

23. 11. The method of claim 10, wherein the content of the charge of the hydrophobic monomer or the charge of the mixture of monomers containing the hydrophobic monomer is 25 to 100 parts per 100 parts of the water.

24. The mixture of monomers including a hydrophobic monomer is charged, and the mixture is a vinyl C ９ ~C ３０ Optionally substituted C alkyl ethers, styrene, derivatives of styrene, ethylene, propylene, 1,3-butadiene, vinyl acetate, vinyl chloride, vinylidene chloride, acrylonitrile, (meth)acrylamide, acrylic acid １ ~C ３０ Alkyl esters and optionally substituted C methacrylic acid １ ~C ３０ 11. The method of claim 10 further comprising at least one monomer selected from the group consisting of alkyl esters.

25. The method of claim 10 , wherein the reaction mixture does not contain a surfactant or micelle-forming agent.

26. The method of claim 10 wherein the mixture of monomers comprises a hydrophobic monomer, and the mixture does not comprise a cross-linking monomer.

27. The method of claim 10, wherein the polymerization temperature is from 50°C to 95°C.

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