Coating composition

Abstract

An aqueous matte finish coating composition comprising at least one acrylic dispersion having a plurality of crosslinked particles comprising a plurality of first acrylic particles having a median weight average particle size of 4 microns or less in diameter and a surface Young's modulus of 450 megapascals or greater; a process for producing said aqueous matte coating composition; and a coated substrate coated with a dried coating made using said aqueous matte coating composition.

Description

[Technical Field]

[0001] The present invention relates to a coating composition, and more particularly to a matte coating composition. The coating composition can be applied to a film substrate to form a matte coated film for use in packaging applications. [Background technology]

[0002] Matte finishes for film structures are commonly used in packaging applications to add further functionality to packaging films, such as optical appearance, tactile or tactile response, ink and image protection for direct printing, improved packaging durability, and improved packaging processing. Most matte finishes are formulated from inorganic fillers such as silica or titanium dioxide and polymer binders (solvent-based or aqueous) such as acrylic and polyurethane. However, inorganic pigments present in matte finishes can reduce abrasion resistance and degrade the tactile feel of the film, and such pigments may adversely affect other performance characteristics of the film. To address the adverse effects caused by inorganic pigments, polymer organic bead particles have been used in matte coating formulations. For example, U.S. Patent Application Publication 20190315994(A1), International Publication 2020076577(A1), and U.S. Provisional Patent Application Publication 63 / 122,686 disclose forming a coating substrate for packaging by applying an aqueous matte coating composition containing acrylic polymer beads onto a film substrate. The aforementioned prior art documents describe forming matte coated products using compositions containing acrylic beads larger than 4.5 microns. However, the matte coated products disclosed in the above references are too large in size to be applied by flexographic (relief printing) and offset printing processes, which are two processes that can be advantageously used in various packaging coating applications. Therefore, they can only be applied by gravure (photographic intaglio) processes.

[0003] Furthermore, matte finish coating film substrates prepared using inorganic pigments exhibit poor color matching and weak abrasion resistance of overprinting vanish (OPV), which are critical control characteristics of coating films for the packaging industry, particularly in providing matte finish coating films that meet the needs of primary packaging applications. In recent years, polyurethane (PU) bead-based matte finishes have been developed that offer excellent matte appearance and soft-touch properties. However, the PU components of such varnishes (i.e., coating formulations) add a considerably high cost to the manufacture of matte coating formulations.

[0004] Other matte coating formulations used for matte packaging applications require the original formulation to be modified or reformulated by individual packaging manufacturers to meet the specific application requirements of those manufacturers. Furthermore, some matte coating formulations offer coatings with a high coefficient of friction (COF). Some ready-to-use matte coating formulations have not been entirely successful in providing performance improvements related to properties such as soft touch, color retention, abrasion resistance, and coating rheology without the need to reformulate the original formulation. However, ready-to-use matte coating formulations still have a high COF, and such formulations are suitable only for gravure printing processes due to the use of acrylic beads with a particle size larger than 4.5 microns (μm) and a lower solids content in the formulation. The larger particle size and lower solids content of the formulations limit their application in flexographic and offset printing processes due to the low transfer efficiency from the anilox roll to the printing roll.

[0005] Therefore, the packaging industry desires the development of matte coating formulations for use in all types of application processes, including gravure printing, flexographic printing, and offset printing. Furthermore, the packaging industry desires to improve the performance of matte coatings. Additionally, the packaging industry desires to provide matte coatings with low COF (Coefficient of Performance). [Overview of the project]

[0006] In one embodiment, the present invention solves the above-mentioned problems of the prior art by incorporating an aqueous matte coating composition containing polymer multi-crosslinked beads having an average particle size of 4.0 μm or less (e.g., an average particle size of 3 μm) and a surface Young's modulus of 450 megapascals (MPa) or more (≧) as a raw material for producing a coating with a matte appearance. The solid content of the coating composition of the present invention is increased (e.g., to more than 35 wt% [>]) to improve the transfer efficiency of flexographic and offset printing processes.

[0007] In another embodiment, an aqueous matte finish coating formulation is prepared that includes a plurality of first acrylic particles having a median weight-average particle size of 4 μm or less in diameter, and in a typical embodiment having a surface Young's modulus of 500 MPa or more.

[0008] In yet another embodiment, the aforementioned multi-crosslinked 3μm size bead formulation may be further formulated with (1) other multi-crosslinked beads of smaller size, such as beads smaller than 1μm size, (2) an acrylic binder, and (3) a unique additive package for forming a matte coating material that can result in a low COF (e.g., COF less than 1.0 [<] for coating / coating-static). The aqueous matte coating composition of the present invention provides a coating with good properties such as a good matte appearance, abrasion resistance, color retention, and soft touch. The aqueous matte coating composition of the present invention is not limited to the use of a gravure process, but can instead be used with gravure processes including reverse gravure and rotary gravure processes, flexographic printing processes, and offset printing processes. Furthermore, 3μm size multi-crosslinked acrylic beads with a higher solids content increase the solids content of the finishing agent formulation and improve the transfer efficiency of flexographic printing and offset printing. The present invention relates to a novel coating composition and solves the process challenges and performance gaps of previous matte coating composition products.

[0009] In yet another embodiment, the present invention relates to a novel matte coating composition or formulation comprising a multi-crosslinked acrylic bead dispersion, an acrylic binder, and an additive. Novel combinations of the above components provide a range of specially designed polymer materials, as well as the applicable processing rheological properties and dry-finished surface morphologies of the polymer materials. The matte finish coatings of the present invention have beneficial performance properties such as a matte appearance, and therefore low gloss at 60°, abrasion resistance, good adhesion, excellent color matching, excellent soft touch, and low COF, as well as better storage stability of the formulation. Furthermore, the novel matte coating compositions of the present invention can be used with several application processes such as gravure printing, including reverse gravure and rotary gravure, flexographic printing, and offset printing.

[0010] In various other embodiments, the matte coating formulation of the present invention may contain various additives such as different defoamers, different rheology modifiers, and different slip additives such as silicone emulsions and wax dispersions to further improve the performance of the matte coating formulation. The matte coating formulation may be combined with various one or more different water-dispersible post-crosslinking agents such as polyisocyanates added immediately before the coating is applied, but is not limited thereto.

[0011] The matte coating composition of the present invention can advantageously be applied using gravure printing, flexographic printing, and offset printing to produce a matte packaging material for premium packaging. The coating composition of the present invention beneficially provides unique properties including, for example, soft touch, low COF, color retention, abrasion resistance, anti-glare (lower gloss), etc.

[0012] In other embodiments, the matte coating composition of the present invention can advantageously be applied onto a polyolefin substrate to construct a reusable polyolefin packaging.

[0013] For example, in one broad embodiment, the matte finishing formulation of the present invention comprises: (A) at least one acrylic-based dispersion having multi-stage crosslinked particles with an average particle size of 4.0 μm or less and a surface Young's modulus of 450 MPa or more, (B) at least one rheology modifier, (C) at least one defoamer, (D) at least one neutralizing agent for adjusting the pH of the formulation to a level of 7.5 - 9.0, (E) at least one wetting additive, (F) at least one slip additive, and (G) at least one water-dispersible post-crosslinking agent.

[0014] In another embodiment, the matte finish formulation of the present invention includes, for example, (A)(Ai) a first acrylic bead dispersion having multi-stage crosslinked particles having an average particle size of 1 μm to 4.0 μm and a surface Young's modulus of 450 MPa or more, and a first polymer phase having a glass transition temperature (Tg) of 20°C (°C) or less and a second polymer phase having a Tg of 30°C or more; and (Aii) unlike the first acrylic bead dispersion, the first polymer phase having a Tg of 20°C or less. (Aiii) a combination of a second acrylic multi-stage crosslinked bead dispersion having a second polymer phase with a Tg of 30°C or higher and an average particle size of 0.2 μm to 0.99 μm, and a third acrylic binder emulsion used as a binder, which differs from the first and second acrylic bead dispersions in that it has a Tg of -30°C to 60°C and a z-average particle size distribution of 0.05 μm to 0.3 μm, and (B) in a general embodiment at least (C) a rheological modifier, which in a preferred embodiment may comprise a combination of two or more different rheological modifiers; (D) a defoaming agent, which in a general embodiment may comprise a combination of two or more different defoaming agents; (E) a wetting additive, which in a general embodiment may comprise a combination of two or more different wetting additives; (F) a slip additive, which in a general embodiment may comprise a combination of two or more different slip additives; (G) a water-dispersible polyisocyanate used as a post-crosslinking agent; and (H) water, which optionally is used as a diluent.

[0015] In yet another embodiment, the matte finish formulation of the present invention comprises, for example, (A)(Ai) a first acrylic bead dispersion having multi-stage crosslinked particles with an average particle size of 1 μm to 4.0 μm and a surface Young's modulus of 450 MPa or more, with a packing concentration of 30% to 70% by dry weight based on the total dry weight of the formulation, and (Aii) unlike the first acrylic dispersion, having a first polymer phase with a Tg of 20°C or less and a second polymer phase with a Tg of 30°C or more. (Aiii) a combination of a second multi-stage crosslinked acrylic bead dispersion having an average particle size of 0.2 μm to 0.99 μm at a packing concentration based on a solid content of 10% to 40% based on the total dry weight of the formulation, and a third acrylic emulsion, unlike the first and second acrylic dispersions, used as a binder with a Tg of -30°C to 60°C, and having a z-average particle size of 0.05 μm to 0.3 μm when used at a concentration of 10% to 30% based on the total dry weight of the formulation, and (B) in a general embodiment (C) a rheological modifier, which in a preferred embodiment may comprise a combination of two or more different rheological modifiers at a total packing concentration of up to 2.0% by dry weight, with the packing amount based on the total dry weight of the formulation, and (D) a defoaming agent, which in a general embodiment may comprise a combination of two or more different defoaming agents at a packing concentration of up to 0.5% by weight, based on the total dry weight of the formulation, and (D) a defoaming agent to adjust the pH of the formulation to a pH level of 7.5 to 9.0. (E) a neutralizing agent, and in a general embodiment, at least one wetting additive, in a preferred embodiment, the wetting additive may include a combination of two or more different wetting additives at a total filling concentration of up to 1.0% dry weight, with the filling amount based on the total dry weight of the formulation; (F) a slip additive, in a general embodiment, at least one slip additive, in a preferred embodiment, the slip additive may include a combination of two or more different slip additives at a total filling concentration of up to 7.0% dry weight based on the total dry weight of the formulation; and (G) 10.A water-dispersible polyisocyanate used as a post-crosslinking agent at a filling concentration of up to 0% dry weight, wherein the filling amount, based on the total dry weight of the formulation, comprises (H) water, optionally used as a diluent.

[0016] In yet another embodiment, the present invention includes a method for applying the aqueous matte coating composition to a substrate, the method comprising: (I) forming an aqueous matte coating composition comprising (a) at least one acrylic bead having an average particle size of 4 μm or less and a surface Young's modulus of 450 MPa or more; (b) at least one polymer binder; (c) at least one slip additive comprising a silicone emulsion and a wax dispersion; and (d) a water-dispersible post-crosslinking agent; (II) applying the aqueous matte coating composition to a substrate; and (III) drying or allowing the applied aqueous matte coating composition to dry.

[0017] In yet another embodiment, the present invention includes a coating substrate coated with the aqueous matte coating composition described above.

[0018] In yet another embodiment, the present invention includes a packaging article made from the above-mentioned aqueous matte coating composition. Furthermore, although this application relates to the invention described in the claims, it may also encompass the following as other embodiments. (1) A water-based matte finish coating compound comprising (a) a plurality of first multi-stage crosslinked acrylic beads having a median weight-average particle size of 4 microns or less and a surface Young's modulus of 450 megapascals or more. (2) The formulation according to (1) above, wherein the particles provide the formulation having a static friction coefficient between coatings of less than 1. (3)(b) The composition according to (1) above, further comprising a plurality of second acrylic beads having a predetermined average particle size of more than 0.2 microns and less than 1.0 micron. (4)(c) The composition described in (1) above, further comprising a binder. (5) The composition according to (4) above, wherein the binder is a third acrylic emulsion different from the first acrylic beads and the second acrylic beads, the binder has a Tg of -30°C to 60°C, and the binder has an average z-average particle size of 0.05 μm to 0.3 μm. (6) The composition according to (1) above, further comprising: (d) at least one rheological modifier; (e) at least one defoaming agent; (f) at least one neutralizing agent for adjusting the pH of the composition to a level of 7.5 to 9.0; (g) at least one wetting additive; (h) at least one slip additive; and (i) at least one water-dispersible post-crosslinking agent. (7) The compound according to (1) above, wherein the multi-stage crosslinked acrylic beads have a core-shell particle form having a first stage and a second stage, the first stage being a crosslinked core having a Tg of 20°C or less, and the second stage being grafted onto the core as a shell, the shell having a Tg of 30°C or more. (8) A dry coating made from the formulation described in (1) above. (9) A matte coating substrate comprising (i) the dry coating described in (8) above, and (ii) the dry coating described in (8) above, which is disposed on the surface of at least one layer of the substrate. (10) The matte coating substrate according to (9) above, wherein the substrate comprises at least one substrate selected from the group consisting of wood, metal, plastic, leather, paper, vinyl, woven fabric, nonwoven fabric film, sheet or container and two or more combinations thereof. (11) A packaging article made from the matte coated substrate described in (9) above. (12) A process for producing the aqueous matte finish coating formulation described in (1) above, (I) A step of synthesizing a first acrylic bead dispersion having a median weight-average particle size of 4 microns or less in diameter and a surface Young's modulus of 450 megapascals or more, (II) A step of mixing the bead dispersion with an aqueous binder emulsion to form a pre-coating formulation, (III) A step of mixing the pre-coating compound with an isocyanate post-crosslinking agent to form a matte coating compound, (IV) A step of applying the matte coating compound to a substrate to form a coating layer on the substrate, (V) A process comprising the step of curing the coating layer or curing it to form a water-based matte finish coating on the substrate. (13) Multilayer acrylic beads, including beads having a median weight-average particle size of 4 microns or less and a surface Young's modulus of 450 megapascals or more. (14) A core-shell particle morphology having a first stage and a second stage, wherein the first stage is a crosslinked core having a Tg of 20°C or less, the second stage is grafted onto the core as a shell, the shell having a Tg of 30°C or more, the beads are functionalized with 0.05% to 5% by weight of a polymerizable organic phosphate or a salt thereof, based on the weight of the beads, and the polymerizable organic phosphate has the following formula: [ka] Or represented by its salt, where R is H or CH 3 And R 1 and R 2 However, each is independently H or CH 3 However, two adjacent CRs 2 CR 1 The base is CH(CH 3 )CH(CH 3 ) Not the group, but each R 3 However, C is independently linear or branched 2 ~C 6 It is an alkylene, m is 2-10, n is 0-5, x is 1 or 2, y is 1 or 2, x+y=3, or n is 1, m is 1, and R is CH 3 And R 1 and R 2 However, each is H, and R 3 However, -(CH 2 The multi-layered acrylic bead described in (13) above, wherein x is 5-, x is 1 or 2, y is 1 or 2, and x+y=3. [Modes for carrying out the invention]

[0019] In this specification, “dispersion” means any polymer crosslinked particles stabilized in a water matrix during polymerization, or in wax and other additives dispersed in water by high-shear mixing.

[0020] In this specification, "emulsion" means an aqueous material prepared by free radical emulsion polymerization of unsaturated monomers.

[0021] In this specification, "matte finish" in relation to coatings means a low-gloss or anti-glare layer coated on a substrate.

[0022] Unless otherwise stated, not implied by the context, or not conventional in the art, all parts and percentages are by weight, all temperatures are in °C, and all test methods are the latest as of the filing date of this disclosure.

[0023] As used herein, the term "composition" refers to a mixture of materials including the composition.

[0024] As used herein, the term "particle size" of acrylic beads refers to the central weight average (D 50 ) particle size measured by the Disc Centrifuge Photosedimentometer (DCP) described in the method section.

[0025] As used herein, the term "z-average particle size" of acrylic emulsion refers to the z-average (D z ) particle size measured by the Malvern dynamic light scattering method described in the method section.

[0026] "Polymer" means a polymeric compound prepared by polymerizing monomers, whether of the same or different types. Thus, the general term "polymer" encompasses the term "homopolymer" (used to refer to a polymer prepared from only one type of monomer, with the understanding that trace impurities may be incorporated into the polymer structure) and the term "interpolymer" defined below herein. Trace impurities (e.g., catalyst residues) may be incorporated in and / or within the polymer. The polymer may be a polymer mixture including a single polymer, a polymer blend, or a mixture of polymers formed in situ during polymerization.

[0027] The term "post-crosslinking agent" refers to a class of materials having more than two reactive chemical groups per molecule that can form a crosslinked network of stable chemical bonds during or after film formation.

[0028] The term "HDPE" generally refers to a type of single-site catalyst, including but not limited to Ziegler-Natta catalysts, chromium catalysts, or bis-metallocene catalysts and geometrically constrained catalysts, prepared using 1 cubic centimeter (g / cm³). 3 ) Over 0.940 grams per unit (multiple units allowed), and a maximum of 0.970 g / cm³ 3 This refers to polyethylene having a certain density.

[0029] The term "ULDPE" generally refers to a single-site catalyst, including but not limited to Ziegler-Natta catalysts, chromium catalysts, or bis-metallocene catalysts and geometrically constrained catalysts, prepared using a concentration of 0.880 g / cm³. 3 ~0.912 g / cm³ 3 This refers to polyethylene having a certain density.

[0030] The terms “comprising,” “including,” and “having,” and their derivatives, are not intended to exclude the presence of any additional components, processes, or procedures, whether or not they are specifically disclosed. To avoid any doubt, all compositions claimed through the use of the term “comprising” may include any additional additives, auxiliaries, or compounds, whether polymeric or otherwise, unless otherwise stated. In contrast, the term “consisting essentially of” excludes any other components, processes, or procedures from the scope of any subsequent description, except those not essential to operability. The term “consisting of” excludes any components, processes, or procedures not specifically described or listed.

[0031] In broad embodiments, the present invention includes, for example, a matte formulation or matte composition comprising: (A) at least one acrylic bead dispersion having multi-stage crosslinked particles with an average particle size of 4.0 μm or less in diameter and a surface Young's modulus of 450 megapascals or more; (B) at least one rheological modifier; (C) at least one defoaming agent; (D) at least one neutralizing agent for adjusting the pH of the formulation to a level of 7.5 to 9.0; (E) at least one wetting additive; (F) at least one slip additive; and (G) at least one water-dispersible post-crosslinking agent.

[0032] In the present invention, component (A), which is a useful acrylic dispersion, may include one or more acrylic dispersions and emulsions.

[0033] In one preferred embodiment, the acrylic bead dispersion is a combination, blend, or mixture of one or more dispersions, and in another preferred embodiment, component (A), which is the dispersion, is a combination of three dispersions or emulsions, such as (Ai) a first acrylic bead dispersion, (Aii) a second acrylic bead dispersion, and (Aiii) a third acrylic emulsion.

[0034] Aqueous dispersions of multi-stage crosslinked acrylic beads can be prepared in various ways, including those described in U.S. Patent Publication No. 2013 / 0052454, U.S. Patents No. 4,403,003, No. 7,768,602, No. 7,829,626, No. 10,676,580B2, No. 10,723,838B2, and No. 10,865,276B2.

[0035] The first and second acrylic beads are multi-stage and crosslinked, comprising a first-stage polymer phase containing a low Tg (less than 20°C in one embodiment, less than 10°C in another embodiment, and less than 0°C in yet another embodiment) homopolymer or copolymer that is crosslinked to provide elasticity and not diffuse into the substrate, and a second-stage polymer phase with a high Tg (greater than 30°C in one embodiment, greater than 50°C in another embodiment, calculated by the Fox formula) for providing beads that are not film-forming at room temperature. The crosslinked first stage comprises at least 50% by weight in one embodiment, at least 70% by weight in another embodiment, and at least 90% by weight in yet another embodiment, (I) butyl acrylate or ethyl acrylate or a combination thereof, and (II) structural units of polyethylenically unsaturated nonionic monomers as exemplified below herein, in a w / w ratio of (I):(II) in one embodiment, ranging from 99.5:0.5 to 85:15. The methyl methacrylate homopolymer comprises at least 60% by weight in one embodiment of the second stage, at least 80% by weight in another embodiment, and 100% by weight in yet another embodiment.

[0036] The first stage of the first acrylic beads and the second acrylic beads contains 85% to 99.9% by weight of structural units of monoethylene unsaturated nonionic monomers, examples of which include acrylic acids such as ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate; methacrylic acids such as methyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, acetoacetoxyethyl methacrylate, and ureid methacrylate; acrylonitrile; acrylamides such as acrylamide and diacetone acrylamide; styrene; and vinyl esters such as vinyl acetate. The first stage may contain structural units of carboxylic acid monomers such as methacrylic acid or acrylic acid, but in certain embodiments, the first stage contains structural units of carboxylic acid monomers based on the weight of the beads, in one embodiment less than 5% by weight, in another embodiment less than 3% by weight, and in yet another embodiment less than 1% by weight. In a preferred embodiment, the first stage includes a structural unit of acrylic acid or methacrylic acid, or a combination of acrylic acid and methacrylic acid.

[0037] In other embodiments, the first stage of the first acrylic beads and the second acrylic beads further contain a polyethylenically unsaturated nonionic monomer in a concentration ranging from 0.1% to 15% by weight in one embodiment, 1% to 12% by weight in another embodiment, and 3% to 10% by weight in yet another embodiment, based on the weight of the first stage monomer. Examples of suitable polyethylenically unsaturated nonionic monomers include allyl methacrylate, allyl acrylate, divinylbenzene, trimethylolpropane trimethacrylate, trimethylolpropane trimethacrylate, butylene glycol (1,3) dimethacrylate, butylene glycol (1,3) diacrylate, ethylene glycol dimethacrylate, ethylene glycol diacrylate, and mixtures thereof.

[0038] In other embodiments, the multi-stage acrylic beads include a core-shell particle morphology in which the first stage is a crosslinked core with a Tg of 20°C or less, and the second stage is grafted onto the core as a shell with a Tg of 30°C or more.

[0039] The crosslinked particles of the first acrylic dispersion have an average particle size (technically, median weight-average particle size, D) of 4 μm or less in one embodiment, in another embodiment, in the range of 1 μm to 4 μm, and in yet another embodiment, in the range of 2 μm to 3.5 μm, as measured using DCP as described below herein. 50 ) has.

[0040] The crosslinked particles of the second acrylic dispersion have an average particle size (technically, median weight-average particle size, D) measured using DCP as described below herein, in one embodiment of 0.99 μm or less, in another embodiment in the range of 0.2 μm to 0.99 μm, and in yet another embodiment in the range of 0.5 μm to 0.9 μm. 50 ) has.

[0041] In preferred embodiments, the multi-crosslinked acrylic bead composition is functionalized with one or more polymerizable organic phosphates or salts thereof in an amount of up to 5% by weight, based on the weight of the beads. Polymerizable organic phosphates useful in the present invention include those with the following general chemical formula (I):

[0042] [ka] Or represented by its salt, where R is H or CH3, 1 and R 2 Each is independently either H or CH3, except for two adjacent CR 2 CR 1 The group is not a CH(CH3)CH(CH3) group, but each R 3R is an independently linear or branched C2-C6 alkylene, m is 2-10, n is 0-5, x is 1 or 2, y is 1 or 2, x+y=3, or n is 1, m is 1, R is CH3, R 1 and R 2 These are H and R respectively. 3 is -(CH2)5-, x is 1 or 2, y is 1 or 2, x+y=3, and the polymer beads have a solids content in the range of 10% to 60% by weight in one embodiment and 30% to 55% by weight in another embodiment, based on the weight of the multi-crosslinked acrylic beads and water.

[0043] In another preferred embodiment, the multi-crosslinked acrylic bead composition is functionalized with 0.2% to 2% by weight of a polymerizable organic phosphate represented by any of the following general chemical formulas (II) in an acid or ammonium salt, based on the weight of the beads.

[0044] [ka] In the formula, m is 4 to 6, and each CR 2 CR 1 The group is either CH(CH3)CH2 or CH2CH(CH3). Sipomer PAM-100 (acid form), Sipomer PAM-200 (acid form), and Sipomer PAM-600 (ammonium salt form) are examples of commercially available compounds of the above formula (II) or the following general chemical formula (III).

[0045] [ka] In the formula, x is 1 or 2, y is 1 or 2, and x + y = 3. In one embodiment, a commercially available compound within the range of formula III is Kayamar PM-21 phosphate ester.

[0046] The multi-crosslinked particles of the first acrylic bead dispersion have an average surface Young's modulus of 450 MPa or more in one embodiment and 500 MPa or more in another embodiment, as measured using atomic force microscopy at 2,000 Hz, as described below herein.

[0047] The filling concentration of the first acrylic dispersion, based on the solid content, is generally 70% or less by dry weight in one embodiment, 30% or more to 70% or less by dry weight in another embodiment, and 40% to 60% by dry weight in yet another embodiment, based on the dry weight of the formulation.

[0048] The filling concentration of the second acrylic dispersion, based on the solid content, is, based on the dry weight of the formulation, 40% by dry weight or less in one general embodiment, 10% by weight or more and 40% by dry weight or less in another embodiment, 15% by dry weight or more and 35% by dry weight in yet another embodiment, and 20% by dry weight or more and 30% by dry weight in yet another embodiment.

[0049] The third acrylic emulsion component (Aiii), unlike the first and second acrylic dispersions, is used as a binder and has a Tg of -30°C to 60°C. For example, the Tg of the binder particles is 60°C or less in a typical embodiment, -30°C to 30°C in another embodiment, -20°C to 20°C in yet another embodiment, and -10°C to 15°C in yet another embodiment.

[0050] The third emulsion component (Aiii) used as a binder includes, for example, an acrylic emulsion, preferably an acrylic one, meaning that these binder particles contain, based on the weight of the binder particles, at least 30 weight percent of one or more methacrylic acid monomers, such as methyl methacrylic acid and ethyl methacrylic acid, and / or structural units of one or more acrylic acid monomers, such as ethyl acrylic acid, butyl acrylic acid, 2-propylheptylacrylic acid, and 2-ethylhexylacrylic acid. The acrylic binder may also contain ethylenically unsaturated acid monomers such as methacrylic acid, acrylic acid, and itaconic acid, or salts thereof, and structural units of other non-acrylic acid monomers or non-methacrylic acid monomers, such as styrene, acrylonitrile, and vinyl acetate.

[0051] In another embodiment, a hydrophobic acrylic binder may be used in the coating formulation to further reduce the COF of the matte finish. The hydrophobic acrylic binder is defined as a binder comprising at least 30% by weight of hydrophobic acrylic or methacrylic esters of tert-butyl alcohol, 2-ethylhexyl alcohol, cyclohexyl alcohol, isobornyl alcohol, lauryl alcohol, and other long-chain linear or branched alcohols, and mixtures thereof.

[0052] In another embodiment, the component (Aiii), which is a third particle used as a binder, may be, for example, a polyurethane dispersion, a polyvinyl acetate emulsion, a styrene-acrylic emulsion, or a mixture thereof.

[0053] The particles of the third acrylic emulsion have a z-average particle size of 0.3 μm or less in diameter in one general embodiment, 0.05 μm or more and 0.3 μm or less in another embodiment, 0.05 μm to 0.25 μm in yet another embodiment, and 0.05 μm to 0.2 μm in yet another embodiment.

[0054] In some embodiments, a third binder emulsion useful in the present invention may be selected from commercially available third acrylic binder emulsion products. For example, the third acrylic binder emulsion may be Opulux® 1000 (available from Dow Inc.), Rhobarr® 110 (available from Dow Inc.), Bayderm® polyurethane dispersion (available from Lanxess, Leverkusen), and mixtures thereof.

[0055] The filling concentration of the third acrylic binder dispersion, based on the solid content, is, based on the dry weight of the formulation, 30% by dry weight or less in one general embodiment, 10% by dry weight or more and 30% by dry weight or less in another embodiment by diameter, 13% by dry weight or more and 28% by dry weight in yet another embodiment, and 17% by weight or more and 25% by weight in yet another embodiment.

[0056] In the present invention, component (B), which is a useful rheological modifier, may contain at least one rheological modifier or a combination of two or more different rheological modifiers at a total fill concentration of up to 2.0% dry weight, where the fill concentration is based on the total dry weight of the formulation. Examples of rheological modifiers used in the present invention are combinations, blends, or mixtures of two or more rheological modifiers, and in a preferred embodiment, component (B), which is a rheological modifier, is a combination of at least two rheological modifiers, such as (Bi) a first rheological modifier and (Bii) a second rheological modifier. In certain embodiments, rheological modifiers include, for example, alkali swellable emulsion (ASE) type polymers, hydrophobically-modified alkali swellable emulsion (HASE) type polymers, hydrophobically modified ethoxylate urethane (HEUR) type polymers, and mixtures thereof.

[0057] For example, component (B1), which is the first rheological modifier, contains a HEUR-type rheological modifier in aqueous solution.

[0058] In some embodiments, the first rheological modifier useful in the present invention may be selected from commercially available rheological modifier products. For example, the first rheological modifier may be Acrysol® RM-2020E (available from Dow Inc.), Acrysol® RM-8W (available from Dow Inc.), or mixtures thereof.

[0059] The packing concentration of the first rheological modifier is generally up to 2.0% by dry weight in one embodiment, 0.1% to 1.5% by dry weight in another embodiment, and 0.3% to 1.0% by dry weight in yet another embodiment, and the packing amount is based on the dry weight of the formulation.

[0060] Examples of the second rheological modifier component (Bii), which is different from the first rheological modifier, include polyacrylic acid rheological modifiers or polymethacrylate rheological modifiers, such as ASE-type polymers in aqueous solution.

[0061] In some embodiments, a second rheological modifier useful in the present invention may be selected from commercially available rheological modifier products. For example, the second rheological modifier may be Acrysol® ASE-60 (available from Dow Inc.), Acrysol® ASE-75 (available from Dow Inc.), or mixtures thereof.

[0062] The filling concentration of the second rheological modifier is generally up to 2.0% by dry weight in one embodiment, 0.05% to 1.5% by dry weight in another embodiment, and 0.1% to 1.0% by dry weight in yet another embodiment, and the filling amount is based on the dry weight of the formulation.

[0063] In the present invention, component (C), which is a useful defoaming agent, may contain at least one defoaming agent or a combination of two or more different defoaming agents at a total filling concentration of up to 0.5% dry weight, the filling amount being based on the total dry weight of the formulation. Examples of defoaming agents are combinations, blends, or mixtures of two or more defoaming agents, and in a preferred embodiment, component (C), which is a defoaming agent, is a combination of at least two defoaming agent components, such as a first defoaming agent and a second defoaming agent.

[0064] For example, component (C), which is a defoaming agent, may be selected from one or more of the following products: Tego Antifoam 4-94 (available from Evonik), Tego Antifoam 2291 (available from Evonik), Tego Antifoam 4-88 (available from Evonik), and mixtures thereof.

[0065] The total filling concentration of the defoaming agent is generally up to 0.5% dry weight in one embodiment, 0.1% to 0.3% dry weight in another embodiment, and 0.15% to 0.25% dry weight in yet another embodiment, and the filling amount is based on the total dry weight of the formulation.

[0066] In the present invention, component (D), which is a useful neutralizing agent, may comprise one or more neutralizing agents. Examples of component (D), which is at least one useful neutralizing agent in the present invention, include ammonia, triethylamine (TEA), other amines, sodium hydroxide, potassium hydroxide, and mixtures thereof.

[0067] In some embodiments, the neutralizing agent useful in the present invention may be selected from commercially available neutralizing agent products. For example, the neutralizing agent may be ammonia (28 percent concentration, available from Fisher), TEA (available from Sigma-Aldrich), or mixtures thereof.

[0068] The neutralizing agent used in the matte coating formulation is used to adjust the pH of the formulation to a level of 7.5–9.0 in one embodiment, 7.8–8.8 in another embodiment, and 8.0–8.5 in yet another embodiment. The pH of the coating formulation is measured using conventional methods and equipment, such as a digital pH meter according to ASTM E70-19.

[0069] In the present invention, component (E), which is a useful wetting additive, may contain at least one wetting additive or a combination of two or more different wetting additives at a total filling concentration of up to 1.0 dry weight%, where the filling is based on the total dry weight of the formulation. Examples of wetting additives are combinations, blends, or mixtures of two or more wetting additives, and in a preferred embodiment, component (E), which is a wetting additive, is a combination of at least two wetting additive components, such as a first wetting additive and a second wetting additive.

[0070] For example, the wetting additive component (E) may be selected from one or more of the following products: Triton GR-5M (available from Dow Inc.), Polystep B-5 (available from Stepan), and mixtures thereof.

[0071] The total filling concentration of the wetting additive is generally up to 1.0% by dry weight in one embodiment, 0.1% to 0.8% by dry weight in another embodiment, and 0.2% to 0.6% by dry weight in yet another embodiment, and the filling amount is based on the dry weight of the formulation.

[0072] In the present invention, component (E), which is a useful slip additive, may contain at least one slip additive or a combination of two or more slip additives at a total filling concentration of up to 7.0% by dry weight based on the total dry weight of the formulation. Examples of slip additives are a combination, blend, or mixture of two or more slip additives, and in a preferred embodiment, component (F), which is a slip additive, is a combination of at least two slip additive components, such as (Fi) a first slip additive and (Fii) a second slip additive.

[0073] For example, the component (Fi), which is a useful first slip additive in the present invention, can be selected from commercially available slip additives based on silicone dispersions. For example, the first slip additive may be TE-352FG (available from ICM), Dowsil® DC-51, Dowsil® DC-52, Dowsil® 401, and Dowsil® 27 (all available from Dow Inc.), as well as mixtures thereof.

[0074] The filling concentration of the first slip additive is generally up to 7.0% by dry weight in one embodiment, 0.5% to 5.0% by dry weight in another embodiment, and 1.0% to 3.0% by weight in yet another embodiment, and the filling amount is based on the dry weight of the formulation.

[0075] For example, a component (Fii) which is a second slip additive useful in the present invention can be selected from commercially available slip additives based on wax dispersions. For example, the second slip additive may be Acrawax C (available from Lonza Company), Hydrocer 145 (available from Shamrock), or a mixture thereof.

[0076] The filling concentration of the second slip additive is generally up to 7.0% by dry weight in one embodiment, 1% to 6% by dry weight in another embodiment, and 2% to 5% by dry weight in yet another embodiment, and the filling amount is based on the dry weight of the formulation.

[0077] In the present invention, component (G), which is a water-dispersible polyisocyanate useful as a post-crosslinking agent, may comprise one or more water-dispersible polyisocyanates. Examples of component (G), which is at least one water-dispersible polyisocyanate used as a crosslinking agent in the present invention, include water-dispersible aliphatic diisocyanates such as various forms of hexamethylene di-isocyanate (HDI), methylene dicyclohexyl diisocyanate (also called hydrogenated MDI, HMDI), isophorone diisocyanate (IPDI), and mixtures thereof.

[0078] In some embodiments, the water-dispersible polyisocyanates useful in the present invention may be selected from commercially available water-dispersible polyisocyanate products. For example, the water-dispersible polyisocyanates may be CR9-101 (available from Dow Inc.), Bayhydur® Ultra 2487 / 1, Bayhydur® Ultra 304, and Bayhydur® Ultra 3100 (all available from Covestro), as well as mixtures thereof.

[0079] The packing concentration of at least one water-dispersible post-crosslinking agent is generally up to 10% dry weight in one embodiment, 1.0% to 9.0% dry weight in another embodiment, and 2.0% to 8.0% dry weight in yet another embodiment, and the packing amount is based on the dry weight of the formulation.

[0080] As an optional component (H), water may be added to the coating composition for dilution, such as reducing the total solids content of the coating composition to a desired range. The water can be supplied from any water source. The water may include, for example, deionized water. Furthermore, water can be added to one or more of the other components (A) to (G) to form an aqueous composition, which can then be used to transport the components in a stable, concentrated form.

[0081] If desired, the coating compositions of the present invention may be formulated with a wide variety of additives to enable the performance of specific functions while maintaining the excellent advantages / properties of the compositions of the present invention. For example, useful optional components in the coating formulations of the present invention may be selected from antistatic additives, blocking additives, and mixtures thereof.

[0082] Any compound used in the coating composition of the present invention may generally be present in amounts of up to 2% by dry weight in one embodiment, 0.1% to 1.0% by dry weight in another embodiment, and 0.2% to 0.8% by dry weight in yet another embodiment, with the fill amount based on the dry weight of the formulation.

[0083] In one broad embodiment, the process for producing the matte coating formulation of the present invention includes mixing, blending, combining, or blending the above-mentioned components (A) to (G) to form the matte coating formulation. One or more additional optional components, such as water, optional component (H), may be added to the matte coating formulation as desired. For example, components (A) to (D) may be mixed together at the desired concentrations described above, at a temperature of 10°C to 50°C in one embodiment and 20°C to 30°C in another embodiment. The mixing order of components (A) to (F) is not important, and two or more of these components may be mixed together, after which the remaining components, such as a crosslinking agent or component (G), may be added. The components of the matte coating formulation may be mixed together by any well-known mixing process and apparatus, such as an overhead mixer or a Flacktek speed mixer.

[0084] The matte coating formulations of the present invention produced by the above process have several advantageous properties and benefits. For example, some of the properties / benefits exhibited by the formulations of the present invention may include, for example, high solids content, low foaming, high storage stability at 45°C and 3°C, and suitable application processing rheological properties.

[0085] The viscosity of the coating formulation is measured using conventional methods and equipment, such as a Brookfield viscometer, before the post-crosslinking agent is incorporated into the formulation. For example, the viscosity of the coating composition of the present invention may generally range from 200 millipascal seconds (mPa-s) to 700 mPa-s in one embodiment, from 300 mPa-s to 600 mPa-s in another embodiment, and from 450 mPa-s to 500 mPa-s in yet another embodiment.

[0086] The solid content of the coating formulation is measured using conventional methods and equipment. For example, the solid content of the coating composition of the present invention may generally be in the range of 32% to 55% by weight in one embodiment, 34% to 50% by weight in another embodiment, and 36% to 45% by weight in yet another embodiment.

[0087] The foaming generated by the coating formulation of the present invention should be minimized as much as possible to obtain the best performance of the formulation. Generally, the foaming generated by the formulation is in the range of 0% to 50% in one embodiment, 0.001% to 40% in another embodiment, and 0.01% to 30% in yet another embodiment.

[0088] The storage stability of the coating formulation of the present invention is measured at a temperature of 45°C for one month and at a temperature of 3°C for one month. The storage stability of the coating formulation is determined by visual observation of the formulation to see whether the coating formulation undergoes phase separation during that period. After exposure of the coating formulation of the present invention to 45°C for one month, the coating formulation of the present invention does not undergo phase separation, as can be determined visually with the naked eye.

[0089] The film substrate used to produce the matte coating film substrate of the present invention is generally a polyolefin film web and may contain one or more polyolefins. For example, the film substrate may contain one or more polyolefin layers, such as high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), and mixtures thereof.

[0090] In some embodiments, the polyolefin film coated with the coating formulation of the present invention may include a stretched single-layer PE film or a multi-layer PE film produced using either a mechanically oriented process or a biaxially oriented process, which is bonded to a second layer film substrate. For example, stretched polyolefin films useful in the present invention may be oriented polyethylene (OPE), biaxially oriented polyethylene (BOPE), and mixtures thereof.

[0091] In other embodiments, the polyolefin film may be a polypropylene (PP) film or a biaxially oriented (BOPP) film.

[0092] In further embodiments, the film substrate coated with the coating formulation of the present invention may be a multilayer film structure comprising two or more layers. For example, a multilayer polyolefin film may be a film comprising two or more layers of HDPE, LLDPE, and LDPE.

[0093] In some embodiments, the film substrate may include a laminated film structure comprising a first PE film bonded to a second PE film selected from HDPE, LLDPE, and LDPE, for example, a first PE film selected from HDPE, LLDPE, and LDPE. The multilayer films can be bonded to each other using any conventional adhesive.

[0094] In other embodiments, the film substrate may include, for example, PET, nylon, PLA, and combinations thereof.

[0095] The thickness of the polyolefin film used to form the coating substrate of the present invention may be, for example, 10 μm to 300 μm in one embodiment, 10 μm to 200 μm in another embodiment, and 10 μm to 100 μm in yet another embodiment.

[0096] Generally, the coating substrate of the present invention is manufactured by applying the aqueous matte coating composition of the present invention described above to a film substrate and drying the coating on the substrate. In one preferred embodiment, this process is (I) A step of forming an aqueous matte coating composition, wherein the aqueous matte coating composition is (a) At least one acrylic bead having an average particle size of 4 μm or less and a surface Young's modulus of 450 MPa or more, (b) at least one polymer binder, (c) A step of forming an aqueous matte coating composition comprising at least one slip additive containing a silicone or wax dispersion, (II) A step of applying the aqueous matte coating composition of step (I) to at least a portion of the surface of one or more film substrates to form a coating layer on the substrates, (III) A step of drying or curing (or, optionally) the aqueous matte coating composition applied to the substrate.

[0097] The forming step (I) of the process of the present invention for forming an aqueous matte coating composition comprises the step of combining components (A) to (G) and optionally component (H), as described above.

[0098] One of the advantages of the process of the present invention is that step (II) of the process of the present invention can be carried out by several conventional processes and apparatus well known in the art, such as gravure processes, flexographic printing processes, and offset printing processes.

[0099] In other embodiments, the application step (II) of the process of the present invention for coating (applying) a matte coating composition to a substrate may be carried out by any well-known method, such as a spray method, a brush method, a roll method, an electrostatic bell method, or a fluidized bed method. For example, the coating composition may be applied to the substrate by (1) a curtain coater, (2) an aerosol method such as air atomization spray, air-assisted spray, airless spray, high-volume low-pressure spray, and air-assisted airless spray, (3) roll coating, and (4) knife coating.

[0100] The drying step (III) of the present invention may be carried out in a well-known manner for coating a substrate. For example, the drying step (III) may be carried out by air drying or heat drying at a temperature that does not damage the substrate. For example, the oven temperature for drying in step (III) may be 150°C or less in one embodiment, 100°C or less in another embodiment, 80°C to 150°C in yet another embodiment, and 90°C to 100°C in yet another embodiment. In another embodiment, after coating the film substrate, the coated film is continuously cured at room temperature for 7 days before the coated film material is used for packaging applications.

[0101] If desired, alternative methods for applying a coating compound onto a film substrate to produce a matte coated substrate include, for example, the hand drawdown method, the spray method, the brushing method, or the roller coater method.

[0102] When a coating is applied to a film substrate, the coating weight is generally 0.8 grams per square meter (g / m²) in one embodiment. 2 ) ~5g / m 2 In another embodiment, 1.0 g / m 2 ~4.0g / m 2 In yet another embodiment, 1.6 g / m 2 ~3.2g / m 2 That is the case.

[0103] The matte coating layer of the present invention, formed on a film substrate manufactured by the process described above, has several advantageous properties and benefits. For example, some of the properties / benefits exhibited by the matte finish coating film of the present invention may include, for example, low COF, increased color fit, low gloss, strong abrasion resistance, strong adhesion, and excellent soft touch.

[0104] The low gloss of the coating substrate of the present invention at 60° is generally in the range of 1 to 20 gloss units in one embodiment, 4 to 10 gloss units in another embodiment, and 5 to 10 gloss units in yet another embodiment.

[0105] The low gloss of the coating substrate of the present invention at 85° generally ranges from 1 to 40 gloss units in one embodiment, from 5 to 35 gloss units in another embodiment, and from 10 to 30 gloss units in yet another embodiment. The gloss of the coating substrate formulation is measured using conventional methods and instruments. For example, the gloss properties of a coating film can be analyzed at 60° and 85° using a BYK Gardner Glossmeter (micro-tri-gloss).

[0106] The abrasion resistance of the coating substrate of the present invention is measured using conventional methods and equipment. For example, abrasion resistance is determined using a Sutherland Ink Rub Tester, which provides the number of Sutherland Rub cycles based on 100 cycles / reading. The test is performed with a weight load of 1.8 kilograms (kg) and an operating speed of 1 rub cycle / second. Before performing the above abrasion resistance test, the coating film is cured at room temperature (23°C) for one week. The abrasion resistance of the coating substrate of the present invention generally ranges from 500 to 5,000 Sutherland Rub cycles in one embodiment, from 700 to 4,000 Sutherland Rub cycles in another embodiment, and from 1,000 to 3,000 Sutherland Rub cycles in yet another embodiment.

[0107] The inter-coating (CC) / static COF of the coating substrate of the present invention is generally in the range of 0.1 to 2.0 in one embodiment, 0.2 to 1.5 in another embodiment, and 0.3 to 1.0 in yet another embodiment. The COF of the coating substrate is measured using conventional methods and equipment. For example, the COF of a coating film is determined using a TMI Friction and Slip Tester Model 32-07-00 at 25°C and relative humidity (RH) 50%.

[0108] The soft touch of the coating substrate of the present invention generally falls within the range of 1 to 5 in one embodiment, 3 to 5 in another embodiment, and 4 to 5 in yet another embodiment. The soft touch characteristics of the coating substrate are determined by conventional means, for example, the soft touch of various coating film substrates is compared by a human sensory panel in a sensory evaluation laboratory. The soft touch is determined by detecting the difference in tactile perception when comparing different coating substrates or laminated structures.

[0109] The heat seal resistance of the coating substrate of the present invention is generally in the range of 120°C to 205°C in one embodiment, 130°C to 202°C in another embodiment, and 140°C to 202°C in yet another embodiment. The heat seal resistance of the coating substrate is measured using conventional methods and equipment. For example, the heat seal resistance of a coating film is evaluated by a V-Fold Heat Resistance Test using a heat sealer at a temperature of 205°C, a pressure of 276 kPa, and a duration of 1 second. After heat sealing the film, the coating film is designated as "pass" or "fail". The coating film substrate is "pass" if the adhesive or finishing agent is not removed from the coating, or if the gloss of the coating does not change. The coating film substrate is "fail" if the films undesirably stack together, or if the matte finish peels off from the coating film substrate, or if the gloss of the coating changes.

[0110] The adhesive strength of a coating film can be measured using conventional methods and equipment, such as tape adhesion tests. Tape adhesion tests are performed, for example, using 3M Scotch 610 tape. In the test, the tape is applied to the matte coating with finger pressure, and after a few seconds, the tape is quickly pulled off the coating. The amount of coating that peels off with the tape, if any, is then measured. A rating system numbered 1 to 5 is used to evaluate the adhesive properties of the coating substrate by visually observing the amount of coating peeled off from the coating substrate. A rating of "1" means that 90% or more of the coating peeled off the coating substrate by the tape. A rating of "2" means that 60% or less of the coating peeled off the coating substrate by the tape. A rating of "3" means that 20% or less of the coating peeled off the coating substrate by the tape. A rating of "4" means that 10% or less of the coating peeled off the coating substrate by the tape. A rating of "5" means that the amount of coating removed from the coated substrate by the tape is essentially nonexistent or zero, i.e., the coating is not peeled off the coated substrate by the tape.

[0111] In other embodiments, the adhesive strength of the coating substrate of the present invention is measured by the procedure described in ASTM standard D3359, provided that cross-hatching is not used in the adhesion test (i.e., no cuts are made on the film being tested). For example, the adhesive strength of the coating substrate is in the range of 3 to 5 in one general embodiment, 3 to 5 in another embodiment, and 4 to 5 in yet another embodiment.

[0112] In a typical embodiment, the coating film substrate of the present invention is used in packaging applications for manufacturing various packaging materials and products. For example, the matte coating substrate can be used in food packaging, cosmetic packaging, and electronic device packaging. Other applications include non-food packaging applications such as pesticide packaging. [Examples]

[0113] The following embodiments of the present invention (Embodiments of the Invention) and comparative embodiments (Comparative Embodiments) (collectively referred to as "Embodiments") are presented herein to further illustrate the features of the present invention, but are not intended to be expressly or implicitly construed as limiting the scope of the claims. Embodiments of the Invention are identified by Arabic numerals, and comparative embodiments are represented by alphabetical letters. The performance of embodiments of the compositions described herein was analyzed in the following experiments. Unless otherwise indicated, all parts and percentages are by weight based on total weight.

[0114] In the examples, the following abbreviations have the given meanings. DI = Deionized, PET = Polyethylene terephthalate, OPP = Stretched PP, and HDPE = High-density polyethylene.

[0115] Table I lists the various materials used in the embodiments and comparative embodiments of the present invention.

[0116] [Table 1]

[0117] Examples 1-4 and Comparative Examples A-C General procedure for preparing coating formulations Using the raw materials listed in Table I above, the coating formulation of the present invention, Examples 1 to 4 described in Tables II to V below, and Comparative Examples A to D described in Tables VI to IX below were prepared.

[0118] [Table 2]

[0119] [Table 3]

[0120] [Table 4]

[0121] [Table 5]

[0122] [Table 6]

[0123] [Table 7]

[0124] [Table 8]

[0125] [Table 9]

[0126] General procedure for preparing the components of a coating formulation Synthesis of Bead 1 Beads 1 used in this embodiment are prepared according to the procedure described in Example 6, column 10, lines 30-44 of U.S. Patent No. 10,676,580, with the following modifications: (1) The final solids content of the coating formulation is adjusted to 43%. (2) The allyl methacrylic acid in shots ME and ME1 is both further increased by 50%, while the n-butylacrylic acid in shots ME and ME1 is reduced by the same amount of additional allyl methacrylic acid added to shots ME and ME1. (3) The amount of acrylic oligomer seeds is increased to produce a median particle size of 3.0 μm by weight, and the particle size is measured using DCP as described in column 7, lines 34-44 of U.S. Patent No. 10,676,580.

[0127] Synthesis of Beads 2 Beads 2, which are second-stage acrylic beads having a particle size with an average diameter of 0.85 μm, are manufactured using the procedure described in U.S. Patent No. 9.410,053(B2), Sample D, column 14, lines 1-48.

[0128] Synthesis of Beads 3 Beads 3, which are second-stage acrylic beads having a particle size with an average diameter of 6 μm, are manufactured using the procedure described in Example 2, column 18, lines 50-65 to column 19, lines 1-20 of U.S. Patent No. 7,829,626.

[0129] Synthesis of Beads 4 The beads 4 used in this embodiment are prepared according to the procedure described in Example 6, column 10, lines 30-44 of U.S. Patent No. 10,676,580, with the following modifications: (1) The final solids content of the coating formulation is adjusted to 43%. (2) The amount of acrylic oligomer seeds is adjusted to produce a median particle size of 3.0 μm by weight, and the particle size is measured using DCP as described in column 7, lines 34-44 of U.S. Patent No. 10,676,580.

[0130] Synthesis of binder 1 Binder 1, a two-stage acrylic binder, is manufactured using the procedure described in Example 9, column 21, lines 1-10 of U.S. Patent No. 7,829,626.

[0131] General procedure for preparing coating formulations Generally, in the examples and comparative examples of matte coating formulations for the present invention, the following is performed by loading acrylic bead material into a container equipped with a mixing impeller. Next, a defoaming agent is added to the acrylic bead material in the container, followed by the addition of an acrylic binder while mixing the contents of the container. Rheological modifiers and other additives are added to the container while mixing. After mixing for 10 to 20 minutes (depending on the scale size), the resulting mixture is neutralized with ammonia to obtain a coating material having a pH of 7.5 to 9.0.

[0132] After preparing the coating material as described above, before applying the coating material to the film substrate, add 0.5 to 1.0 part of water-dispersible polyisocyanate (1.4 to 2.8% by dry weight of polyisocyanate based on the dry weight of the coating formulation) per 100 parts of wet material while mixing it into the prepared coating material sample, and continue mixing for 20 minutes before applying the coating material to the substrate.

[0133] Measurement of the properties of matte coating formulations We measured some of the physical properties of the matte coating formulation, and the results of these measurements are shown in Table X.

[0134] [Table 10] Notes to Table X: * "PS" stands for "phase separation".

[0135] General procedure for applying matte coating formulations A matte coating formulation was applied to a film substrate using a gravure process. The matte coating was applied to different film substrates at an operating speed of 122 m / min using pilot gravure laminators, namely Labo Combi and Super Combi (Examples 3 and 4 of the present invention).

[0136] Using a Super Combi coater, a matte coating was applied to different film substrates at an operating speed of 152 m / min (Example 2 of the present invention, Comparative Example A, Comparative Example B, and Comparative Example C).

[0137] A matte coating was applied to a PET film substrate at a speed of 305 m / min using a TC customer's Robbie W&H Miraflex CM flexographic printing press (Example 1 of the present invention).

[0138] Test method and measurement Foaming test The foaming of the coating formulation is measured using a method that includes the following steps: Step (1): Weigh 300 grams (g) of the sample, place it in a 4.7-liter (L) stainless steel bowl, and provide a mixer such as a Kitchen Aid Stand Mixer model RRK5A used to mix the contents of the bowl. Step (2): After ensuring the mixer speed control is off, place the bowl lift handle in the lowered position. Attach the bowl support to the positioning pin, push down the rear of the bowl until the bowl pin snaps into the spring latch, then lift the bowl before mixing the contents. Step (3): Attach the stainless steel wire whip by sliding it onto the beater shaft and pushing it upwards as far as possible. Turn the beater to the right and hook it onto the pin on the shaft. Step (4): Gradually move the mixer's speed control lever to setting #6 and mix the contents of the bowl for 5 minutes (min) ± 10 seconds (s). Step (5): Turn off the mixer, remove the bowl from the mixer, and immediately pour the mixed sample from the bowl into a clean specific gravity cup (100 ml [mL] size). Measure and record the density of the sample mixture. Step (6): Calculate the percentage of foam generated using the following general formula (I). [(Weight before mixing - Weight after mixing) / (Weight before mixing)] x 100 = Foam % Equation (I)

[0139] viscosity The viscosity of the compounded product (before incorporating the crosslinking agent into the formulation) is measured using a Brookfield viscometer DV I. + Measurements were taken at 23°C using spindle #2.

[0140] gloss The gloss characteristics of coated PET films were analyzed at 60° and 85° gloss by directly measuring the coating surface at room temperature using a BYK Gardner Glossmeter (micro-tri-gloss) according to ASTM D523. The reported data are averages based on 10 data points measured from different locations on the coating. Before performing the gloss test, all coated films were cured for one week at room temperature (25°C) and 50% humidity.

[0141] Wear resistance Abrasion resistance (Sutherland friction) was measured using a Sutherland® 2000® friction tester at room temperature, with a 1.8 kg weight pad, at operating speed 2, in accordance with ASTM D-5264. Prior to the coating-to-coating abrasion resistance test, all coating films were cured for one week at room temperature (25°C) and 50% humidity. Test data was recorded based on 100 cycles / reading.

[0142] Coefficient of friction (COF) The COF of the coating film was determined using a TMI friction and slip tester Model 32-07-00 at 25°C and 50% relative humidity, according to the procedure described in ASTM D1894. COF tests were performed both coating-to-coating and coating-to-stainless steel panels using a 200g thread at a sliding speed of 15cm / min over a travel distance of 5cm. COF data was collected from the average of triplicates. Both static and dynamic COF were measured for coating-to-coating (C / C) and coating-to-stainless steel (C / S).

[0143] Soft touch The soft-touch properties were compared using a human sensory panel in a sensory evaluation laboratory. Softness was determined by detecting differences in tactile perception when comparing different laminated structures.

[0144] Heat seal resistance The heat seal resistance of the coating film was measured at a temperature of 205°C, with a measurement of 2.76 × 10⁻⁶. 5 The film was evaluated by a V-Fold heat seal resistance test using a heat sealer at a pressure of Pa and a duration of 1 second. After heat sealing the film, the coating film was designated as "pass" or "fail," where "pass" meant that the adhesion or finish was not removed, or the gloss did not change, and "fail" meant that the film was undesirably stacked, the matte finish peeled off, or the gloss changed.

[0145] Tape adhesion Using 3M Scotch 610 tape, a tape adhesion test was performed by applying the tape to a 2.5 cm long area of ​​the coating with finger pressure, confirming that no air bubbles were formed in the adhesive area. Next, after a few seconds, the tape was quickly peeled off the coating adhesive area, and the tape was observed to determine whether the coating had peeled off from the substrate.

[0146] A rating system numbered 1-5 is used to evaluate the adhesion properties of a coated substrate by visually observing the amount of coating peeled off from the substrate. A rating of "1" means that 90% or more of the coating peeled off the substrate by the tape. A rating of "2" means that 60% or less of the coating peeled off the substrate by the tape. A rating of "3" means that 20% or less of the coating peeled off the substrate by the tape. A rating of "4" means that 10% or less of the coating peeled off the substrate by the tape. A rating of "5" means that there is essentially no or zero amount of coating peeled off the substrate by the tape, i.e., the coating is not peeled off the substrate by the tape.

[0147] Glass transition temperature (Tg) In this specification, the Tg of polymers is calculated using the Fox formula (TGFox, Bull. Am. Physics Soc., Volume 1, Issue No. 3, page 123 (1956)). That is, the following general formula (II) is used to calculate the Tg of a copolymer of monomers M1 and M2.

[0148]

number

[0149] The Tg values ​​of various monomers can be found, for example, in the "Polymer Handbook" edited by J. Brandrup and E. Himmergut (Interscience Publishers).

[0150] Malvern Particle Sizing Method for Binder Emulsions The particle size of the acrylic binder emulsion was measured using a Malvern Zetasizer Nano ZS90 analyzer, which uses dynamic light scattering (DLS) at a scattering angle of 90° with Zetasizer software version 7.11 to determine the Z-average particle size (D z The particle size was measured. One drop of emulsion was diluted with a 0.01 M NaCl aqueous solution (ultrapure water, type I, ISO3696), and further diluted as needed to obtain particle counts in the range of 100 to 400 kilocounts / second (Kcps). Particle size measurement was performed using the instrument's particle size metric method and by software D zD was calculated. z This is also known as the harmonic mean particle size based on strength and is represented by equation (III).

[0151]

number

[0152] In the above equation (III), S i is diameter D i This is the scattering intensity from particle i having [specific characteristic]. Detailed D z The calculation is described in ISO 22412:2017 (Particle size analysis - Dynamic light scattering (DLS)).

[0153] Acrylic bead particle size The particle size of the multi-crosslinked bead dispersion used in coating formulations is measured using a Disc Centrifuge Photosedimentometer (DCP, CPS Instruments, Inc., Prairieville, LA) that separates modes by centrifugation and sedimentation with a sucrose gradient. Samples were prepared by adding 1-2 drops of the bead dispersion to 10 mL of deionized (DI) water containing 0.1% sodium lauryl sulfate, followed by injecting 0.1 mL of the sample into a rotating disk filled with a 15 g / mL sucrose gradient. A 2%-8% sucrose gradient disk rotating at 10,000 rpm was used, and an 895 nanometer (nm) polystyrene calibration standard was injected before sample injection. The median weight-average (D) particle size was measured. 50 Determine the particle size.

[0154] Solid content The solid content of the coating compound and its individual components is determined by placing approximately 1 g of the wet dispersion on an aluminum pan and weighing it if recording is required. Next, the pan containing the sample is placed in a 150°C oven for 30 minutes. The pan containing the dry sample is weighed and the dry sample weight is recorded. The solid content is calculated as the ratio of the dry sample weight to the wet sample weight using the following formula (IV). Solid content % = (Weight of dry sample / Weight of wet sample) * 100 Formula (IV)

[0155] Sample preparation for AFM The acrylic bead dispersion was diluted with water to 1 / 20 (v / v), cast onto a freshly cut mica surface, and then dried in a paper-covered petri dish at room temperature for 3 days before AFM analysis.

[0156] Surface Young's modulus measurement by AFM using PF-QNM Samples were analyzed using a Bruker Icon AFM system with PeakForce QNM based on PeakForce Tapping mode. In PeakForce Tapping, the probe was vibrated at a frequency of 2,000 Hz, and a specified peak force (the maximum nominal force applied to the sample) was used for feedback control. Force curves were collected each time the tip interacted with the sample, and the nanomechanical properties were analyzed. Only force curves collected at the top of the beads were extracted to calculate Young's modulus using SPIP Image Processor Software (Image Metrology, Denmark). Table XI shows the parameters used in the embodiments discussed in this application.

[0157] [Table 11]

[0158] The Young's modulus was calculated according to the DMT spherical intrusion model (referenced from Derjaguin, BV, VMMuller, and Y. Toporov, "Effect of contact deformations on the adhesion of particles," Journal of Colloid and Interface Science, 1975, 53(2): pp. 314-326), as shown in the following general formula (V).

[0159]

number

[0160] The Young's modulus of bead 1 (size 3 μm) was compared with that of bead 4 (size 3 μm) at a frequency of 2,000 Hz. Compared to bead 4's Young's modulus of 380 MPa, bead 1's Young's modulus was 557 MPa.

[0161] The results show that the 3μm bead 1 has a higher surface modulus and therefore has a COF-C / C-static of less than 1. On the other hand, the 3μm bead 4 has a lower surface modulus and therefore has a COF-C / C-static of greater than 1.

[0162] Performance of matte coating The matte coatings from all the examples were placed on a 12 μm thick PET film substrate, and the performance of these coated films was measured. The results of these measurements are shown in Table XII.

[0163] [Table 12] Notes regarding Table XII: 1 "C / C" stands for "coating versus coating". 2 "C / S" stands for "Coated vs. Steel." * Test up to 1,500 cycles. ** 1B-5B scale: "1B" = Coating removed, "5B" = Coating undamaged. ***Sensory panel test: "1" = worst and "5" = best. **** "NT" = Not tested.

[0164] The matte coating according to Example 2 of the present invention was placed on various film substrates having various film thicknesses, and the performance of such coated film substrates was measured. The results of these measurements are shown in Table XIII.

[0165] [Table 13] Notes to Table XIII: * Tested up to 1,000 cycles, no damage to the coating surface was observed. ** 1B-5B scale: "1B" = Coating removed, "5B" = Coating undamaged.

Claims

1. A water-based matte finish coating compound, (a) A plurality of first multi-crosslinked acrylic beads comprising 30% to 70% by dry weight, comprising allyl methacrylate and n-butyl acrylate, having a median weight-average particle size of 4 microns or less and a surface Young's modulus of 450 megapascals or more. (b) A second acrylic bead in an amount of 15% to 35% by dry weight, having a predetermined average particle size of more than 0.2 microns to less than 1.0 micron, and (c) A water-based matte finish coating formulation comprising a binder in an amount of 10% to 30% by dry weight, wherein the binder is a third acrylic emulsion different from the first acrylic beads and the second acrylic beads.

2. The formulation according to claim 1, wherein the formulation has a coating-to-coating static friction coefficient of less than 1.

3. The compound according to claim 1, wherein the binder is a third acrylic emulsion different from the first acrylic beads and the second acrylic beads, the binder has a Tg of -30°C to 60°C, and the binder has an average z-average particle size of 0.05 μm to 0.3 μm.

4. (d) at least one rheological modifier, (e) at least one defoaming agent, (f) at least one neutralizing agent for adjusting the pH of the compound to a level of 7.5 to 9.

0. (g) at least one wetting additive, (h) at least one slip additive, and (i) The composition according to claim 1, further comprising at least one of at least one water-dispersible post-crosslinking agents.

5. The compound according to claim 1, wherein the multi-stage crosslinked acrylic beads have a core-shell particle form having a first stage and a second stage, the first stage being a crosslinked core having a Tg of 20°C or less, and the second stage being grafted onto the core as a shell, the shell having a Tg of 30°C or more.

6. A dry coating made from the formulation described in claim 1.

7. A matte coating substrate comprising (i) the dry coating according to claim 6, and (ii) the dry coating according to claim 8, which is disposed on the surface of at least one layer of the substrate.

8. The matte coating substrate according to claim 7, wherein the substrate comprises at least one substrate selected from the group consisting of wood, metal, plastic, leather, paper, vinyl, woven fabric, nonwoven fabric film, sheet or container, and two or more combinations thereof.

9. A packaging article made from a matte coating substrate as described in claim 7.

10. A process for producing the aqueous matte finish coating compound according to claim 1, comprising: (I) a step of synthesizing a first acrylic bead dispersion having a median weight-average particle size of 4 microns or less in diameter and a surface Young's modulus of 450 megapascals or more; (II) A step of mixing the bead dispersion with an aqueous binder emulsion to form a pre-coating formulation, (III) A process comprising the step of mixing the pre-coating formulation with an isocyanate post-crosslinking agent to form a matte coating formulation.

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