PRINTED COATED SUBSTRATE AND ITS PREPARATION PROCESS
Patent Information
- Authority / Receiving Office
- MX · MX
- Patent Type
- Patents
- Current Assignee / Owner
- DOW GLOBAL TECHNOLOGIES LLC
- Filing Date
- 2022-09-23
- Publication Date
- 2026-05-19
Abstract
Description
COATED PRINTED SUBSTRATE AND ITS PREPARATION PROCESS DESCRIPTION OF THE INVENTION Printing ink is often desired to create an image on a plastic surface. It is usually desirable to subsequently protect the printed surface. Without protection, the image is vulnerable to damage, for example, by scratching, which can occur during shipping or handling, and / or by distortion when the printed surface is heated, for example, during a sealing operation. In the past, it was common to protect the printed image by bonding a transparent plastic cover film to the printed surface, usually by lamination. Such laminates often have one or more of the following undesirable characteristics: added complexity in the manufacturing process or additional cost. WO 2016 / 196168 describes a coated film, where the film comprises polyethylene and the coating comprises polyurethane. It is desired to provide a method for making a coated printed substrate having one or more of the following advantages: good appearance, good abrasion resistance, good high temperature resistance, and / or good chemical resistance. Preferably, the coated printed substrate has one or more of these advantages to a greater extent. Ref. 338559 sufficient that it is not necessary to join a layer of plastic cover to the coated surface. The following is a statement of invention. A first aspect of the present invention is a process for producing a coated printed substrate comprising (a) providing a printed substrate, the substrate comprising a surface upon which reside one or more areas of a layer of an ink, the ink comprising (i) one or more copolymers of a definite, and (ii) one or more appearance additives selected from one or more pigments, one or more dyes and mixtures thereof, and (iii) one or more conductivity additives, (b) combining an A component with a B component to form a urethane coating composition, wherein component A comprises an A1 polyisocyanate prepolymer, wherein the A1 polyisocyanate prepolymer is a reaction product of an A1 polyisocyanate monomer and an A1 isocyanate-reactive polycompound, wherein component B comprises one or more B1 polyols, wherein the urethane coating composition has an isocyanate number greater than 0.9, and (c) applying a layer of the urethane coating composition to the surface. A second aspect of the present invention is a coated printed substrate that is made by the method of the first aspect of the present invention. The following is a detailed description of the invention. As used in this description, the following terms have the definitions indicated, unless the context clearly indicates otherwise. As used herein, polymer and plastic are synonymous. A polymer is a molecule made up of many repeating units. There may be more than one type of repeating unit; that is, the polymer may be a homopolymer (exactly one type of repeating unit) or a copolymer (more than one type of repeating unit). A polymer has a molecular weight of 5,000 or more. A polymer may be linear, branched, crosslinked, or any combination thereof. A polyolefin is a polymer in which 75% or more by weight based on the weight of the polymer, of the repeating units have the structureI: R1R R3R4j where each of R1, R2, R3, and R4 is independently hydrogen or an olefin group. Any one of R1, R2, R3, and R4 may be the same as or different from any of the other Rs. R1, R2, R3, and R4. Two or more of R1, R2, R3, and R4 can combine to form a cyclic structure. Polyethylene is a polymer in which 75% or more by weight based on the weight of the polymer, of repeating units have structure II (ethylene units). —-ch2— ch2ii As used herein, an olefin copolymer is a polymer having repeating units of structure I and also having repeating units containing one or more oxygen atoms. Suitable oxygen-containing repeating units include, for example, acrylic units (structure III), ester units (structure IV), and carbonyl units (structure V): R5Ί CH?--C — C' O O--R6 III R5 is methyl or hydrogen and R6 is hydrogen or is a substituted or unsubstituted alkyl group. R8 and R9 are each, independently of each other, a substituted or unsubstituted alkyl group. Suitable substituents include hydroxyl groups, carboxyl groups, nitrogen-containing groups, groups containing carbon-carbon double bonds, other substituents, and combinations thereof. In an olefin copolymer, the repeating units of structure I and the one or more oxygen-containing repeating units may be arranged in the copolymer in any order, including, for example, random, alternating, block, branched, or any combination thereof. In an olefin copolymer, 75% or more of the repeating units, by weight based on the weight of the polymer, are of structure I or an oxygen-containing repeating unit. As used herein, an isocyanate-reactive group is a chemical group capable of reacting with an isocyanate group to form a covalent bond between the isocyanate group and the isocyanate-reactive group. An intact isocyanate group is an isocyanate group that has not reacted with an isocyanate-reactive group. An intact isocyanate-reactive group is an isocyanate-reactive group that has not reacted with an isocyanate group. A compound that has one or more isocyanate-reactive groups is characterized by functionality, which is the number of isocyanate-reactive groups per molecule. In a mixture of compounds that each have one or more isocyanate-reactive groups per molecule, the functionality of the mixture is the number-average functionality. Similarly, a compound that has one or more isocyanate groups is characterized by functionality, which is the number of isocyanate groups per molecule. In a mixture of compounds that each have one or more isocyanate groups per molecule, the functionality of the mixture is the number-average functionality. A compound having isocyanate-reactive groups and having a functionality of 2 or more is referred to herein as a polyisocyanate-reactive compound. A polyol is a compound that has two or more hydroxyl groups. A polyol that has two or more ether linkages is a polyether polyol. A polyol that has two or more ester linkages is a polyester polyol. A polyol that has two or more urethane linkages is a polyurethane polyol. A polyol that has two or more carbonate linkages is a polycarbonate polyol. A polyol that has two or more residues from an epsilon-caprolactone ring-opening polymerization reaction is a polycaprolactone polyol. A polyol can be characterized by its OH number, as determined by ASTM D4274-16 (American Society of Testing and Materials, Conshohocken, PA, USA). A low molecular weight polyol has a molecular weight of 300 or less. A composition containing intact isocyanate groups may be characterized by the isocyanate index, which is the ratio of the number of all intact isocyanate groups in the composition to the number of all intact isocyanate-reactive groups in the composition. A composition containing intact isocyanate groups may also be characterized by the NCO content, which is the weight percent of isocyanate groups based on the weight of the composition, as determined by ASTM D2572-19 (American Society of Testing and Materials, Conshohocken, PA, USA). If the composition contains solvent, the NCO content may be stated as solvent-containing, meaning that the percent NCO content is based on the weight of the entire composition, or the NCO content may be stated as solvent-free, meaning that the percent NCO content is based on the weight of the non-solvent portion of the composition. A compound containing one or more isocyanate groups per molecule is an isocyanate. A compound containing two or more isocyanate groups per molecule is a polyisocyanate. An isocyanate that has one or more aromatic rings in the molecule is an aromatic isocyanate. An isocyanate that has no aromatic rings in the molecule is an aliphatic isocyanate. A polyisocyanate monomer is a polyisocyanate that has a molecular weight of 700 or less. As used herein, a solvent is a compound that is liquid over a temperature range including 10°C to 30°C and that does not participate in the chemical reaction between isocyanate groups and isocyanate-reactive groups. A solvent has a boiling point of 200°C or less. As used herein, a fatty compound is a compound containing a linear hydrocarbon group having 8 or more carbon atoms bonded together in a line. A fatty compound containing a carboxyl group or carboxylate anion is a fatty acid. A fatty compound containing a hydroxyl group is a fatty alcohol. As used herein, a fatty triglyceride is a compound having the structure of a triester of glycerol with three fatty acids. The portion of the fatty triglyceride that would have been derived from one of the fatty acids (if the fatty triglyceride had been formed by an esterification reaction between the fatty acids and glycerol) is known as the fatty acid residue. As used herein, a natural oil polyol is a fatty triglyceride having two or more hydroxyl groups. As used herein, a wax ester is a compound having the structure of an ester of a fatty acid and a fatty alcohol and which is solid over a temperature range including 10°C to 40°C. A mixture of wax esters is also referred to herein as a wax ester. Also included in the term wax ester are mixtures in which 80% or more by weight of the ingredients consist of one or more wax esters, while the remaining 20% or less by weight consists of substances that are not wax esters. As used herein, a printed surface is a surface upon which one or more areas of printing ink reside. On the printed surface, the printing ink is dry, meaning that the printing ink contains, by weight based on the weight of the printing ink, 10% or less of all compounds having a boiling point of 120 C or less. The printing ink contains 15% or more by weight based on the weight of the printing ink, of one or more olefin copolymers. The printing ink also contains one or more pigments, one or more dyes, or a mixture thereof. The digital printing ink also contains one or more conductivity additives. Conductivity additives are also known as charge directors or imaging agents. Conductivity additives increase the electrical conductivity of the ink. As used herein, wettability of a surface refers to the tendency of a liquid placed upon the surface to form a thin, spread layer rather than a rounded, localized microsphere. The greater the tendency of such liquids to form a thin, spread layer rather than a rounded, localized microsphere, the better the wettability is considered in the present disclosure. Specifically, in the present disclosure, the class of liquids used to evaluate wettability is the class of liquids that contain 50% or more by weight of one or more hydrocarbon compounds and that also contain (i) one or more ethylene copolymers, (ii) one or more appearance additives selected from one or more pigments, one or more dyes, and mixtures thereof, and (iii) one or more imaging agents. As used herein, TDI is toluene diisocyanate and MDI is diphenylmethane diisocyanate. The present invention involves a coating composition, which is formed by combining a component A and a component B. Component A contains one or more polyisocyanates. Component A preferably contains one or more Al prepolymers, which are reaction products of one or more Ala polyisocyanate monomers and one or more Al isocyanate-reactive polycompounds. The Al prepolymer is a polyisocyanate. The Ala polyisocyanate monomer preferably contains one or more aromatic polyisocyanate monomers, or one or more aliphatic polyisocyanate monomers, or a mixture thereof. More preferably, the Ala polyisocyanate monomer contains one or more aromatic polyisocyanate monomers. Most preferably, the Ala polyisocyanate monomer contains one or more monomers selected from 2,6-TDI; 2,4-TDI; 2,4'-MDI; 4,4'-MDI, and mixtures thereof. The isocyanate-reactive polyol Alb preferably contains one or more polyols. Suitable polyols for the isocyanate-reactive polyol Alb include, for example, polyether polyols, polyester polyols, polyether-polyester polyols, polyurethane polyols, polycarbonate polyols, polycaprolactone polyols, natural oil polyols, and mixtures thereof. Preferred polyols for the isocyanate-reactive polyol Alb are polyether polyols, polyester polyols, and mixtures thereof. More preferred are polyether polyols, low molecular weight polyols, and mixtures thereof. Suitable low molecular weight polyols include, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, triisopropanolamine and mixtures thereof. Preferably, the isocyanate-reactive polycomposite Alb contains one or more isocyanate-reactive polycomposites having a functionality of 2 or more. Preferably, the isocyanate-reactive polycomposite Alb contains one or more isocyanate-reactive polycomposites having a functionality of 6 or less; more preferably, 5 or less; most preferably, 4 or less. When the isocyanate-reactive polyol Alb comprises one or more polyols, preferably one polyol has a molecular weight of 50 or more; more preferably, 100 or more. When the isocyanate-reactive polyol Alb comprises one or more polyols, preferably one polyol has a molecular weight of 4000 or less; more preferably, 2000 or less. Component A may or may not contain solvent. Examples of suitable solvents are ethyl acetate, propyl acetate, cyclohexane, methyl acetate, methyl ether ketone, toluene, and mixtures thereof. Preferred solvents are ethyl acetate, propyl acetate, cyclohexane, methyl ether ketone, and mixtures thereof; more preferred are ethyl acetate, propyl acetate, cyclohexane, and mixtures thereof. If solvent is present in component A, preferably all ingredients of component A are dissolved in the solvent. Preferably, the amount of solvent in component A, by weight based on the weight of component A, is 20% or more; more preferably, 30% or more. Preferably, the amount of solvent in component A, by weight based on the weight of component A, is 70% or less; more preferably, 50% or less. Preferably, the NCO content of component A, with solvent, is 5% or more; more preferably, 7% or more. Preferably, the NCO content of component A, with solvent, is 15% or less; more preferably, 13% or less. Preferably, the NCO content of component A without solvent is 8% or more; more preferably, 12% or more. Preferably, the NCO content of component A without solvent is 25% or less; more preferably, 22% or less. Preferably, component A contains one or more fatty triglycerides. Fatty triglycerides in which one or more fatty acid residues have 12 or more carbon atoms are preferred, more preferably 16 or more carbon atoms. Fatty triglycerides in which one or more of the fatty acid residues have one or more carbon-carbon double bonds are preferred. Preferably, the amount of fatty triglyceride in component A is, by weight based on the weight of component A, 0.1% or more; more preferably, 0.2% or more; more preferably, 0.3% or more. Preferably, component A contains one or more fatty triglycerides. Preferably, the amount of fatty triglyceride in component A is, by weight based on the weight of component A, 10% or less; more preferably, 5% or less; most preferably, 3% or less. Preferably, component A contains one or more wax esters. Examples of suitable wax esters include, but are not limited to, cetyl palmitate, palmityl stearate, stearyl stearate, hydrogenated tallow, carnauba wax, beeswax, and mixtures thereof. Cetyl palmitate, palmityl stearate, stearyl stearate, hydrogenated tallow, and mixtures thereof are preferred. A mixture of cetyl palmitate, palmityl stearate, stearyl stearate, and hydrogenated tallow is most preferred. Preferably, the amount of wax ester in component A is, by weight based on the weight of component A, 0.1% or more; more preferably, 0.2% or more; more preferably, 0.3% or more. Preferably, the amount of wax ester in component A is, by weight based on the weight of component A, 10% or less; more preferably, 5% or less; most preferably, 3% or less. Component B contains one or more isocyanate-reactive polyols B1. Preferably, the isocyanate-reactive polyols B1 contain one or more polyols. Suitable polyols for inclusion in the isocyanate-reactive polyols B1 include, for example, polyether polyols, polyester polyols, polyether-polyester polyols, polyurethane polyols, polycarbonate polyols, polycaprolactone polyols, natural oil polyols, and mixtures thereof. Preferably, the isocyanate-reactive polyol compound B1 contains one or more polyurethane polyols. Suitable polyurethane polyols for use in the isocyanate-reactive polyol compound B1 are preferably the reaction products of one or more polyisocyanate monomers B1a and one or more polyols B1b. The polyisocyanate monomer B1a may be an aromatic polyisocyanate, an aliphatic polyisocyanate, or a mixture thereof. Preferably, the polyisocyanate monomer B1a contains one or more aromatic polyisocyanate monomers. Preferred polyisocyanate monomers in B1a are 2,6-TDI; 2,4-TDI; 2,2'-MDI; 2,4'-MDI; 4,4'-MDI, and mixtures thereof. Preferably, the polyisocyanate monomer B1a contains one or more polyisocyanate monomers having a functionality of 2 or more. Suitable polyols for inclusion in the Blb polyol include, for example, polyether polyols, polyester polyols, polyether-polyester polyols, polyurethane polyols, polycarbonate polyols, polycaprolactone polyols, natural oil polyols, and mixtures thereof. Preferred polyols for the Blb polyol are polyether polyols, low molecular weight polyols, and mixtures thereof. Suitable low molecular weight polyols include, for example, ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, trimethylolpropane, triisopropanolamine, and mixtures thereof. Preferably, the amount of polyurethane polyol B1PU in component B is, by weight based on the weight of component B, 20% or more; more preferably, 30% or more; more preferably, 49% or more. Preferably, the amount of polyurethane polymer B1PU in component B is, by weight based on the weight of component B, 95% or less; more preferably, 85% or less; most preferably, 75% or less. Preferably, one or more of the polyols included in polyol B1b do not react with the isocyanate compound and are present in component B. Preferably, component B comprises one or more anti-blocking agents. An anti-blocking agent reduces blocking on the surface of polymer films and other plastic articles to allow easier processing and handling of the films. The anti-blocking agent can be inorganic or organic. Examples of inorganic anti-blocking agents include, but are not limited to, talc and silica. Examples of organic anti-blocking agents include, but are not limited to, cellulose acetate butyrate. Mixtures of anti-blocking agents are also suitable. Preferably, the amount of anti-blocking agent in component B is, by weight based on the weight of component B, 0.05% or more; more preferably, 0.1% or more; more preferably, 0.2% or more. Preferably, the amount of anti-blocking agent in component B is, by weight based on the weight of component B, 10% or less; more preferably, 5% or less; most preferably, 3% or less. Preferably, component B comprises one or more wetting agents. A wetting agent improves the flow and leveling of a liquid and reduces any tendency of the liquid to form pinholes, fish eyes, craters, mottled surfaces (called orange peel), or any combination thereof, when the liquid is applied as a layer to a surface. Examples of suitable wetting agents include, but are not limited to, acrylic polymers, siloxanes, and mixtures thereof. Preferably, the amount of wetting agent in component B is, by weight based on the weight of component B, 0.05% or more; more preferably, 0.1% or more; more preferably, 0.2% or more. Preferably, the amount of wetting agent in component B is, by weight based on the weight of component B, 10% or less; more preferably, 5% or less; most preferably, 3% or less. Component B may or may not contain solvent. Examples of suitable solvents are ethyl acetate, propyl acetate, cyclohexane, methyl acetate, methyl ether ketone, toluene, and mixtures thereof. Preferred solvents are ethyl acetate, propyl acetate, cyclohexane, methyl ether ketone, and mixtures thereof; more preferred are ethyl acetate, propyl acetate, cyclohexane, and mixtures thereof. If solvent is present in component B, preferably all of the ingredients in component B are dissolved in the solvent. Preferably, the amount of solvent in component B, by weight based on the weight of component B, is 5% or more; more preferably, 10% or more. Preferably, the amount of solvent in component B, by weight based on the weight of component B, is 80% or less; more preferably 70% or less. In the practice of the present invention, component A and component B are combined and the resulting mixture is a urethane coating composition. Preferably, component A and component B are then thoroughly mixed. A layer of the coating composition is applied to a substrate. It is anticipated that isocyanate groups on component A will react with isocyanate-reactive groups on component B. Preferably, the layer of the coating composition is applied to the substrate at a time when 50 mole % or less of the isocyanate groups on component A have reacted with isocyanate-reactive groups on component B. It is useful to consider the mixture of component A and component B before any chemical reaction between them takes place. The isocyanate index of such a mixture is 0.9 or more; preferably, 1.0 or more; more preferably, 1.1 or more; most preferably, 1.2 or more. The isocyanate index of such a mixture is preferably 2 or less; more preferably, 1.8 or less; most preferably, 1.6 or less. In the practice of the present invention, a layer of the urethane coating composition is applied to the surface of the printed substrate. Preferably, at a time subsequent to the application of the ink to the substrate, but before the layer of the urethane coating composition is applied to the substrate, the surface of the substrate is subjected to a surface treatment. Suitable surface treatments alter the surface energy of the substrate in a manner that improves the wettability of the substrate surface. Examples of suitable surface treatments include, for example, corona treatment and plasma treatment. Preferably, the urethane coating composition, prior to the curing process, is a liquid at the temperature at which the urethane coating composition is applied to the substrate. Preferably, the liquid urethane coating composition, when applied to the printed surface of the substrate, exhibits good wetting, both on the areas of the substrate that are covered by printing ink and on the areas of the substrate (if any) that come into direct contact with the liquid urethane coating composition. That is, the liquid urethane coating composition preferably forms a smooth, uninterrupted layer over the entire covered portion of the substrate, without voids. Such voids are sometimes observed when a liquid coating composition pulls away from portions of the substrate surface, typically due to surface tension, to form structures such as microspheres or fish eyes. It is anticipated that, after the layer of the urethane coating composition has been applied to the substrate, some or all of the isocyanate groups will react with some or all of the isocyanate-reactive groups, thereby forming a cured polyurethane layer. To promote this reaction, the layer of the urethane coating composition may be heated. When 80 mole % or more of the isocyanate groups have reacted, the layer of urethane coating composition is said herein to have become a cured polyurethane layer. If the urethane coating composition contains one or more solvents, preferably, after the layer of the urethane coating composition has been applied to the substrate, the solvent is forced to evaporate or allowed to evaporate from the coating composition.When heating the layer of the urethane coating composition, it is contemplated that the act of heating the layer of the urethane coating composition on the substrate will serve to promote evaporation of the solvent, as well as to promote the curing reaction. Preferably, the average thickness of the cured polyurethane layer is 0.5 micrometers or more; more preferably, 1 micrometer or more. Preferably, the average thickness of the cured polyurethane layer is 10 micrometers or less; more preferably, 7.5 micrometers or less; most preferably, 5 micrometers or less. The substrate is a printed surface. Preferably, within the area of the substrate covered by the layer of the urethane coating composition, the portion of the substrate covered by ink is 10% or more; more preferably, 20% or more; most preferably, 50% or more. Preferably, within the area of the substrate covered by the layer of the urethane coating composition, the portion of the substrate covered by ink is 100% or less. On the printed surface, the ink is dry. The amount of olefin copolymer in the ink, by weight based on the weight of the ink, is 1% or more; more preferably, 5% or more; more preferably, 10% or more. The amount of ethylene-acrylic copolymer in the ink, by weight based on the weight of the ink, is 99% or less; more preferably, 95% or less; most preferably, 90% or less. The ink contains one or more conductivity additives. The amount of conductivity additive in the ink, by weight based on the weight of the dry ink, is preferably 0.5% or more; more preferably 1% or more; more preferably 1.5% or more. The amount of conductivity additive in the ink, by weight based on the weight of the dry ink, is preferably 15% or less; more preferably 10% or less; most preferably 5% or less. The substrate preferably has a thickness of 20 to 200 micrometers. The substrate preferably comprises one or more polymers; preferably, the amount of polymer in the substrate is 50% or more; more preferably, 75% or more; most preferably, 90% or more. The substrate may be a single layer of polymer, or the substrate may be made of multiple polymer layers. When the substrate has multiple layers, any layer may have the same composition as one or more of the other layers, or that layer may have a composition that is different from all of the other layers. Any layer may optionally contain one or more impact modifiers or other additives. The compounds may optionally be present between the layers, for example, to act as co-extrusion adhesives and / or insulating layers. The substrate layer that is in contact with the printing ink and the urethane coating composition of the present invention is referred to herein as the top substrate layer. Preferably, the top substrate layer contains one or more polyolefins or one or more polyesters or a combination thereof. Preferably, the amount of polyolefin in the top substrate layer is 50% by weight or more; more preferably, 75% or more; most preferably, 90% or more. Suitable polyolefins include, for example, polypropylene, polyethylene, and mixtures thereof. Suitable forms of polyethylene include, for example, linear polyethylene homopolymer (HDPE), linear low-density polyethylene, homopolymer, linear medium-density polyethylene homopolymer, low-density polyethylene homopolymer, and blends of two or more of these. Suitable polyesters include, for example, polyethylene terephthalate. The cured polyurethane layer is expected to be durable. That is, the cured polyurethane layer is expected to resist degradation due to one or more of the following stressors: scratching, exposure to harsh chemicals, wrinkling, and heat. Printed substrates, if not protected in some manner (e.g., by a durable coating or by an additional laminate layer), are considered highly vulnerable to any of the aforementioned stressors. In particular, the printing ink would suffer appearance degradation and / or adhesion to the substrate when exposed to any of the stressors. In the past, to protect the printed surface, it was common to bond a layer of an additional polymer on top of the printed surface (i.e., laminate an additional polymer layer onto the printed surface). Common additional polymers were polyethylene terephthalate and biaxially oriented polypropylene. Typically, the thickness of the additional polymer layer was 8 to 25 micrometers. iviA / a / zuzz / u ι i oz / In contrast to the prior art of laminating an additional polymer layer, in the practice of the present invention, the cured polyurethane layer provides a durable surface, and lamination of an additional polymer layer is not necessary. Preferably, after the printed surface has been coated by practicing the present invention, no additional polymer layers are laminated to the coated printed surface. An object having a coated printed surface of the present invention can be used for any purpose. Suitable purposes include, for example, using an object having a coated printed surface of the present invention as part of a bag or other packaging, for example, for holding food. Other purposes include, for example, packaging for personal and household care products, protective films, printed coatings, and labels. Preferably, when an object having a coated printed surface of the present invention is used for any purpose, no additional polymer layers are laminated to the coated printed surface. The following are examples of the present invention. Operations were carried out at room temperature (approximately 23°C) except where otherwise indicated. The following test methods were used. (ASTM refers to the American Society for Testing and Materials (American Society for Testing and Materials) Society of Testing and Materials), Conshohocken, PA, USA). The wettability of the liquid coating composition on the printed substrate was visually evaluated. The smoother and more uniform the liquid coating composition layer, the better the wettability was rated. Ridges and valleys were considered evidence of unevenness in the liquid coating composition layer. Scratch resistance was evaluated using ASTM D702705. Temperature resistance was evaluated using ASTM 1921. Gloss was evaluated using ASTM D2457. Chemical resistance was evaluated using the following test. One ml of a liquid simulant was placed directly onto the coated ink on a printed film. At 0.5 hours, 4 hours, and 24 hours, the printed film was subjected to five cycles of creasing and flattening by hand. The film was then rated as follows: Good: The ink and coating remained on the surface unchanged Fair: Portions of ink and varnish were randomly removed from the film surface Bad: Ink and coating are discolored and completely removed from the film surface Temperature resistance was evaluated using a method based on ASTM 1921 and ASTM D2457. The test result is the lowest temperature at which the sample begins to show obvious damage, such as drastic shrinkage or film burn. Various printing inks were used to produce multi-color printed images. The approximate composition of the inks, before drying, is believed to be as follows (weight percentages based on the weight of the printing ink): Less than 80% petroleum hydrocarbon, less than 15% olefin copolymer, approximately 2.5% conductivity additive, approximately 3.5% dyes and pigments The substrate used in the tests was as follows. The symbol pm refers to micrometer. Percentages are by weight based on the layer weight. PA is polyamide. Polyamide can be coextruded with polyethylene and / or maleic anhydride-modified polyethylene. 12 is the melt index measured at 90°C using 2.16 kg, expressed in units of grams per 10 minutes. D is the density, in grams per cubic centimeter. iviA / a / zuzz / u ι i / Layer Thickness (pm) Product A (top) 30 Linear low density polyethylene (LLDPE) 12 = 0.85, D = 0.918 B 20 Polyethylene modified with maleic anhydride 12 = 2.0, D = 0.950 c 10 PA D 20 Maleic anhydride modified polyethylene 12 = 2.0, D = 0.950 E 20 Linear low density polyethylene (LLDPE) 12 = 0.85, D = 0.918 The following Examples of coating composition of the present invention were used. Component A of example 1 Ingredient Description Amount (% by weight) Ethyl acetate Solvent from UNIVAR, Inc. 24,049 Trimethylolpropane from Lanxess Corp, functionality = 3 11,480 Toluene diisocyanate (TDI) monomeric Mondur TD-80 Grade B from Covestro 43,612 Synaceti 125 wax ester from Werner G. Smith, Inc. 1,191 Corn oil Fatty triglycerides, refined corn oil from Cargill Inc. 1,191 Cyclohexane Cyclohexane from UNIVAR, Inc. 18,423 Benzoyl chloride Benzoyl chloride from Aldrich Chemical Co. 0.055 To prepare Composition A of Example 1, the wax ester and trimethylolpropane were charged to the reactor followed by ethyl acetate. TDI was charged under vacuum to the reactor followed by the remainder of the ethyl acetate as a rinse. The batch was held at 70°C for 3 hours. The batch was then cooled to 55°C. The viscosity of the batch was measured. If the viscosity was less than 380 mPa*s (380 cP), the batch viscosity was adjusted to 380 mPa*s (380 cP) by the addition of trimethylolpropane. If the viscosity was greater than 380 mPa*s (380 cP), or after adding more trimethylolpropane, then the reactor was cooled to 55°C. The corn oil was charged under vacuum to the reactor. Cyclohexane was then added to the reactor, and the contents were maintained at 45°C and stirred for 45 minutes until the contents became clear. Benzoyl chloride was then vacuum-charged into the reactor, and the contents were stirred for 15 minutes.Reactive Composition A was then packaged for use. Component A of example 2. Ingredient Description Amount (% by weight) Ethyl acetate Solvent from UNIVAR, Inc. 24.049 Trimethylolpropane Trimethylolpropane from Lanxess Corp, MW = 134; functionality = 3 6.471 Diphenylmethylene diisocyanate ISONATE 125M from Dow Chemical Company 48.62 Synaceti 125 wax ester from Werner G. Smith, Inc. 1.191 Corn oil Fatty triglycerides, refined corn oil from Cargill Inc. 1.191 Cyclohexane Cyclohexane from UNIVAR, Inc. 18.423 Benzoyl Chloride Benzoyl Chloride from Aldrich Chemical Co. 0.055 iviA / a / zuzz / u ι i / To prepare Composition A of Example 2, the wax ester and trimethylolpropane were charged to the reactor followed by ethyl acetate. The MDI was charged under vacuum to the reactor followed by the remaining ethyl acetate as a rinse. The batch was held at 70°C for 3 hours. The batch was then cooled to 55°C. The corn oil was charged under vacuum to the reactor. The cyclohexane was then added to the reactor and the contents were held at 45°C and stirred for 45 minutes until the contents became clear. The benzoyl chloride was then charged under vacuum to the reactor and the contents were stirred for 15 minutes. Reactive Composition A was then packaged for use. Component B of example 1 Ingredient Description Amount (% by weight) Ethyl acetate Solvent from UNIVAR, Inc. 26.5861 Triisopropylanolamine (TIPA) polyol from The Dow Chemical Company; MW = 191; functionality: 3 20.2901 Toluene diisocyanate (TDI) monomeric Mondur TD-80 Grade B from Covestro 17.8299 Voranol™ 220-260 polyether diol (nominal molecular weight of 13.8618 425), functionality = 2, OHN = 260 from The Dow Chemical Company Voranol™ 220-1 ION Polyether Polyol, MW = 1000; Functionality: 2; OHN = 110 from The Dow Chemical Company 21.4276 SAG-47 Antifoam from Momentive Performance Materials 0.0046 To prepare Reagent Composition B of Example 1, TIPA was melted. Voranol 220-260 was vacuum charged to a reactor. The molten TIPA was vacuum charged to the reactor, followed by VORANOL 220-110N. The vacuum lines were flushed with ethyl acetate, and the reactor contents were stirred at 75 RPM. The ethyl acetate was vacuum charged to the reactor. The reactor contents were cooled through a cooling jacket. After cooling, TDI was charged to the reactor, and the vacuum lines were flushed with ethyl acetate. Due to the exothermic nature of the reaction, the reactor contents were cooled to 75°C. The temperature in the reactor was maintained at 75°C with stirring for 4 hours. The reactor contents were then cooled to 60°C, and a mixture of the antifoam and the remaining ethyl acetate was vacuum-charged into the reactor. The contents were then stirred for 30 minutes.The reactor was then cooled to 50°C, and Reactive Composition B was packaged for use. Component B of example 2 Ingredient Description Amount (% by weight) Ethyl acetate Solvent from UNIVAR, Inc. 34,196 Triisopropylanolamine (TIPA) Polyol from The Dow Chemical Company; MW = 191; Functionality: 3 17,644 Toluene diisocyanate (TDI) monomeric Mondur TD-80 Grade B from Covestro 15,505 Voranol™ 220-260 polyether diol (nominal molecular weight 425), functionality = 2, OHN = 260 from The Dow Chemical Company 12,054 Voranol™ 220-110N Polyether polyol, MW = 1000; Functionality: 2; OHN = 110 from The Dow Chemical Company 18.633 SAG-47 Antifoam from Momentive Performance Materials 0.004 CAB-381-0.5 Cellulose acetate butyrate, antiblocking agents from Eastman Chemical Company 1.121 CAB-551-0.01 Cellulose acetate butyrate, antiblocking agents from Eastman Chemical Company 0.280 Modaflow wetting agent, leveling agent, acrylic polymer from Allnex 0.561To prepare Reagent Composition B of Example 2, TIPA was melted. Voranol 220-260 was vacuum charged into a reactor. The molten TIPA was vacuum charged to the reactor, followed by VORANOL 220-110N. The vacuum lines were flushed with ethyl acetate, and the reactor contents were stirred at 75 RPM. Ethyl acetate was vacuum charged to the reactor. The reactor contents were cooled through a cooling jacket. After cooling, TDI was charged to the reactor, and the vacuum lines were flushed with ethyl acetate. Due to the exothermic nature of the reaction, the reactor contents were cooled to 75°C. The temperature in the reactor was maintained at 75°C with stirring for 4 hours. After the reactor contents were cooled to 60°C, a mixture of the antifoam, cellulose acetate butyrate, modaflow, and the remaining ethyl acetate was vacuum-charged into the reactor. The contents were then stirred for 60 minutes at 60°C.The reactor was then cooled to 50°C, and Reactive Composition B was packaged for use. The following comparative examples were used. Comparative example Product Supplier Comments C3 Siegwerk Flexo 1K Coating OPV One-component polyurethane C4 Sun Chemical SQ2K Gloss Coating Two-component polyurethane C5 Sericol UV-curing varnish 002 believed to be acrylic In the scratch resistance test, an area of the substrate was printed with a uniform block of a single-color printing ink, and that printed area was evaluated. The result is the number of scratch cycles performed before the sample surface showed any visible damage. The test stopped at 50 cycles, even though the best samples showed no damage at that point. The results were as follows: Example Number of scratch cycles before damage 1 50 2 50 C3 30 C4 45 C5 20 The examples of the present invention showed better scratch resistance than all the comparative examples. In the Chemical Resistance Test, three different chemical reagents were used: Cl = a liquid disinfectant solution containing chlorine Cl / det = the same solution as in Cl, with added detergent liq = a general-purpose commercial liquid household cleaning solution Three different resting times were used: 0.5 h (hour), 4 h and 24 h. iviA / a / zuzz / u ι i / The results were as follows: CI CI ci Cl / det Cl / det Cl / det light light light Example 0.5 h 4h 24 h 0.5 h 4h 24 h 0.5 h 4h 24 h 1 good good good good good good good good good 2 good good good good good good good good good C3 good bad bad bad bad bad bad bad bad C4 good bad bad bad bad bad bad bad C5 good average bad good average bad good average bad At 0.5 hours, all examples showed good performance. At 4 hours and 24 hours, the examples of the present invention showed better chemical resistance than all comparative examples. The temperature resistance test was performed as described above. The results were as follows: Example Temperature (°C) 1 175 2 175 C3 125 C4 155 C5 135 uncoated printed film 75 The examples of the present invention showed better temperature resistance than all the comparative examples. The uncoated film showed damage to 75°C; Comparative Examples C3, C4 and C5 showed damage from 125°C to 155°C, while the inventive examples showed no damage up to 175°C. In the gloss test, the result is the gloss observed at a 60-degree angle. The results were as follows: Example Gloss (%) 1 77 2 82 C3 58 C4 72 C5 65 uncoated printed film 41 The examples of the present invention showed better gloss than all the comparative examples. It is noted that in relation to this date, the best method known to the applicant to put the aforementioned invention into practice is the one that is clear from the present description of the invention.
Claims
1. A process for producing a coated printed substrate, characterized in that it comprises (a) providing a printed substrate comprising a surface on which one or more areas of a layer of an ink reside, wherein the ink comprises (i) one or more copolymers of a certain type, and (ii) one or more appearance additives selected from one or more pigments, one or more dyes and mixtures thereof, and (iii) one or more conductivity additives, (b) combining a component A with a component B to form a urethane coating composition, wherein the component A comprises a polyisocyanate prepolymer Al, wherein the polyisocyanate prepolymer Al is a reaction product of a polyisocyanate monomer Ala and an isocyanate-reactive polycomposite Alb, wherein the component B comprises one or more polyols Bl, wherein the urethane coating composition has an isocyanate index greater than 0.9, and (c) apply a layer of the urethane coating composition to the surface.
2. The process according to claim 1, characterized in that the polyol B1 comprises one or more polyurethane polyols B1PU, wherein the polyol B1PU comprises a reaction product of a polyisocyanate monomer BIPUa and a polyol BIPUb.
3. The process according to claim 1, characterized in that the copolymer to be defined is selected from the group consisting of ethylene / acrylic copolymers, ethylene / ester copolymers, ethylene carbonyl copolymers, and mixtures thereof.
4. The process according to claim 1, characterized in that component A comprises one or more fatty triglycerides.
5. The process according to claim 1, characterized in that component A comprises one or more wax esters.
6. The process according to claim 1, characterized in that component B further comprises one or more anti-blocking agents.
7. The process according to claim 1, characterized in that component B further comprises one or more wetting agents.
8. The process according to claim 1, characterized in that the substrate comprises polyethylene. iviA / a / zuzz / u ι i / 9. The process according to claim 1, characterized in that the urethane coating composition has an isocyanate index of 0.9 to 1.
6.
10. A coated printed substrate, characterized in that it is manufactured by the process in accordance with claim 1.