Articles including polymeric sheets and coatings and coated substrates including same

Abstract

A coated substrate may include a transparent substrate and an article positioned on at least a portion of a first surface of the substrate. An article may include a polymeric sheet including a first surface and a second surface opposite the first surface. The polymeric sheet may comprise a neutralized ethylene acid copolymer material containing carboxylic acid groups. The carboxylic acid groups of the ethylene acid copolymer may be at least partially neutralized with metal ions. The article may also include a coating in direct contact with at least a portion of the first surface of the polymeric sheet. The coating may comprise an acrylic material. The coating may be an air contact layer.

Description

Cross-references to related applications

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 520,239, filed on August 17, 2023, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0002] This disclosure relates to polymer materials, and more specifically to coated polymer sheets. Background Technology

[0003] Transparent substrates often lack sufficient protective properties for their intended use. For example, portable electronic devices such as mobile phones typically have large, valuable, and fragile screens. Extensive research has been conducted to develop less fragile screens and screen protectors. Screen protectors can be applied to screens at the factory or by the end user. In either case, screen protectors benefit from acceptable adhesion to the screen, relatively high impact resistance, and / or relatively high hardness (to provide scratch and / or crack resistance). Summary of the Invention

[0004] There is a need for novel articles that provide one or more of the following: acceptable adhesion to the screen, relatively high impact resistance, and / or relatively high hardness. In some embodiments, such articles can be used as screen protectors. As described herein, such articles may comprise a polymer sheet and a coating in contact with the polymer sheet. In particular, the polymer sheet may comprise a neutralized vinyl acid copolymer, at least partially neutralized with metal ions, and the coating may comprise an acrylic material. In one or more embodiments, this combination of materials can provide beneficial effects such as enhanced scratch resistance and / or impact resistance while maintaining suitable optical properties of the screen protector.

[0005] According to one or more embodiments, an article may include a polymer sheet comprising a first surface and a second surface opposite the first surface. The polymer sheet may comprise a neutralized vinyl acetate copolymer material containing carboxylic acid groups. These carboxylic acid groups of the vinyl acetate copolymer may be at least partially neutralized with metal ions. The article may also include a coating in direct contact with at least a portion of the first surface of the polymer sheet. The coating may comprise an acrylic material. The coating may be an air contact layer.

[0006] According to one or more other embodiments, a coated substrate may include a transparent substrate and an article. The article may be located on at least a portion of a first surface of the substrate. The article may include a polymer sheet including a first surface and a second surface opposite the first surface. The polymer sheet may contain a neutralized vinyl acetate copolymer material containing carboxylic acid groups. These carboxylic acid groups of the vinyl acetate copolymer may be at least partially neutralized with metal ions. The article may also include a coating in direct contact with at least a portion of the first surface of the polymer sheet. The coating may contain an acrylic material. The coating may be an air contact layer.

[0007] These and other embodiments are described in more detail in the detailed description. It should be understood that both the foregoing general description and the following detailed description present embodiments of the technology disclosed in this invention and are intended to provide an overview or framework for understanding the nature and features of the technology as claimed. Drawings are included to provide a further understanding of the technology disclosed in this invention, and these drawings are incorporated in and form a part of this specification. The drawings illustrate various embodiments and, together with the description, serve to explain the principles and operation of the technology disclosed in this invention. Furthermore, the drawings and description are intended to be illustrative only and are not intended to limit the scope of the claims in any way. Attached Figure Description

[0008] The following detailed description of specific embodiments of this disclosure is best understood in conjunction with the following drawings, in which similar reference numerals indicate similar structures and in the drawings:

[0009] Figure 1 A cross-sectional view of an article of manufacture according to one or more embodiments described herein is schematically depicted; and

[0010] Figure 2 A cross-sectional view of another article according to one or more embodiments described herein is schematically depicted.

[0011] Reference will now be made in more detail to various embodiments, some of which are shown in the accompanying drawings. Where possible, the same reference numerals will be used throughout the drawings to refer to the same or similar parts. Detailed Implementation

[0012] This document describes one or more embodiments of articles comprising polymer sheets and coatings. The construction of the polymer sheets and coatings, as well as their materials, are generally described.

[0013] A "copolymer" is defined as a polymer compound prepared by polymerizing multiple different types of monomers. Trace amounts of impurities (e.g., catalyst residues) may be incorporated into and / or within the copolymer.

[0014] The term "neutralization percentage" is defined as the degree of neutralization or ionization of the total acid fraction present in a neutralized vinyl acetate copolymer material. The neutralization percentage can range from 0% to greater than 100%. At 0%, the acid groups are not ionized. At 100%, all acid groups have been neutralized or ionized. When more than 100% of the acid groups are neutralized, the neutralized cations loosely associate with the acid groups.

[0015] The term "haze" is defined as the percentage of transmitted light that deviates from the incident beam due to forward scattering as it passes through a membrane sample. Haze can also be defined as a measure (expressed as a percentage of total transmitted light) of the intensity of transmitted light scattered over a 2.5° angle. When observed through a membrane sample, haze may appear milky, smoky, or a blurred view. Low values ​​are measures of low "haze".

[0016] This disclosure will now be described with reference to specific implementation methods. For example... Figure 1 The depicted coating substrate 100 may include a transparent substrate 106 and an article 108 positioned on at least a portion of a first surface of the substrate 106. The article 108 may include a polymer sheet 104 including a first surface and a second surface opposite the first surface. The polymer sheet 104 may comprise a neutralized vinyl acetate copolymer material containing carboxylic acid groups, wherein the carboxylic acid groups of the vinyl acetate copolymer are at least partially neutralized by metal ions. The article 108 may also include a coating 102 in direct contact with at least a portion of the first surface of the polymer sheet 104. The coating 102 may comprise an acrylic material. The coating 102 may be an air contact layer. The article 108 may be adapted to be attached to the substrate 106 or may already be attached to the substrate 106 to form the coating substrate 100.

[0017] Still referencing Figure 1 In one or more embodiments, the polymer sheet 104 may be positioned immediately adjacent to the coating 102. In some embodiments, the polymer sheet 104 may be in direct contact with the coating 102. In embodiments where the article 108 forms part of the coated substrate 100, the polymer sheet 104 may be positioned between the coating 102 and the substrate 106. In some embodiments, the polymer sheet 104 may be in direct contact with the substrate 106. Alternatively, as... Figure 2 As depicted, the polymer sheet 104 can be separated from the substrate 106 via the adhesive layer 202. In embodiments where the article 108 is not positioned immediately adjacent to the substrate 106, the polymer sheet 104 may be an air contact layer. Alternatively, in embodiments where the article 108 is not positioned immediately adjacent to the substrate 106, the polymer sheet 104 may be positioned between the adhesive layer 202 and the coating 102, and the adhesive layer 202 may be an air contact layer.

[0018] As previously mentioned herein, polymer sheet 104 may contain a neutralized ethylene copolymer. The neutralized ethylene copolymer may be an ionomer. The neutralized ethylene copolymer may contain ethylene and a carboxylic acid, such as those provided by acrylic acid, methacrylic acid, or both. The carboxylic acid functional group may be at least partially neutralized with a metal (such as sodium, magnesium, lithium, or zinc). The term "base resin" refers to the composition of the ethylene copolymer prior to neutralization to form the neutralized ethylene copolymer. The weight percentage of acid in the base resin (wt% acid) is based on the total weight of all α,β-ene unsaturated carboxylic acid monomers and ethylene in the base resin. The weight percentage of acid in the base resin is measured by Fourier transform infrared spectrophotometry (FTIR analysis) using a standard calibrated by titration. The degree of neutralization can be measured by several techniques. Thus, infrared analysis can be employed, and the degree of neutralization can be calculated from the changes in the absorption bands produced. Another method includes titrating a solution of the ionic copolymer with a strong base. Another method includes X-ray fluorescence. All of these methods are within the skill of those skilled in the art.

[0019] The neutralized ethylene copolymer may contain copolymer units of ethylene and acrylic acid, methacrylic acid, or both. In an embodiment, based on the total polymer weight of the neutralized ethylene copolymer, the neutralized ethylene copolymer may contain 70% to 85% by weight, such as 75% to 85% by weight, 80% to 85% by weight, 70% to 80% by weight, 70% to 75% by weight, 75% to 80% by weight, or any subset thereof, of ethylene copolymer units, and 15% to 30% by weight, such as 15% to 25% by weight, 15% to 20% by weight, 20% to 30% by weight, 25% to 30% by weight, 20% to 25% by weight, or any subset thereof, of acrylic acid or methacrylic acid copolymer units.

[0020] According to some embodiments, the neutralized vinyl acid copolymer may contain a carboxylic acid group. The carboxylic acid group may be derived from acrylic acid, methacrylic acid, a comonomer, or a combination thereof. The carboxylic acid group may be neutralized with one or more metal salts. The cation of the metal salt may be monovalent, divalent, trivalent, or have a higher valence. The metal salt may include alkali metal salts, such as sodium (Na), potassium (K), or both; alkaline earth metal salts, such as beryllium (Be), zinc (Zn), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra); cationic salts, such as aluminum (Al), chromium (Cr), iron (Fe), or lanthanide metal cationic salts; or combinations thereof. In embodiments, the metal salt may include sodium, magnesium, zinc, or combinations thereof.

[0021] From 0.1% to 100% of the carboxylic acid groups in the neutralized vinyl acid copolymer can be neutralized by a metal salt. In embodiments, 1% to 100%, 5% to 100%, 10% to 100%, 20% to 100%, 40% to 100%, 60% to 100%, 80% to 100%, 0.1% to 80%, 0.1% to 60%, 0.1% to 40%, 0.1% to 20%, 5% to 95%, 10% to 90%, 20% to 80%, 30% to 70%, 30% to 60%, 20% to 40%, or any subset thereof of the carboxylic acid groups in the neutralized vinyl acid copolymer can be neutralized by a metal salt. In embodiments, 40% to 70% of the carboxylic acid groups in the neutralized vinyl acid copolymer can be neutralized with a sodium cation.

[0022] In the context of this disclosure, the following assumption is used to present the neutralization percentage: each cation will react with the maximum number of carboxylic acid groups calculated based on its ionic charge. That is, assuming, for example, Al 3+ It will react with three carboxylic acid groups, Mg 2+ and Zn 2+ It will react with two carboxylic acid groups, and Na + It will react with a carboxylic acid group. The neutralization level can be calculated according to the following equation:

[0023]

[0024] In the embodiments, based on the total polymer weight of the neutralized ethylene copolymer, the neutralized ethylene copolymer may further comprise 1% to 35% by weight of comonomers. Comonomers may include carbon monoxide, sulfur dioxide, acrylonitrile, maleic anhydride, maleate diester, maleic acid, maleate monoester, itaconic acid, fumaric acid, fumarate monoester, salts of these acids, glycidyl acrylate, glycidyl methacrylate and glycidyl vinyl ether, methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, amyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate and butyl methacrylate, amyl methacrylate or combinations thereof. In the implementation, based on the total polymer weight of the neutralized ethylene copolymer, the neutralized ethylene copolymer may contain 1% to 30% by weight, 1% to 25% by weight, 1% to 20% by weight, 1% to 15% by weight, 1% to 10% by weight, 1% to 5% by weight, 5% to 35% by weight, 10% to 35% by weight, 15% to 35% by weight, 20% to 35% by weight, 25% to 35% by weight, 30% to 35% by weight, 5% to 30% by weight, 10% to 25% by weight, 15% to 20% by weight, or any subset thereof of comonomers.

[0025] The neutralized vinyl acid copolymer may have a melt flow index (I2) of 0.1 g / 10 min to 6 g / 10 min as measured according to ASTM D1238. In embodiments, the neutralized vinyl acid copolymer may have a melt flow index (I2) of 0.9 g / 10 min to 13 g / 10 min, 0.9 g / 10 min to 10 g / 10 min, 0.9 g / 10 min to 5 g / 10 min, 0.9 g / 10 min to 6 g / 10 min, 1 g / 10 min to 6 g / 10 min, 2 g / 10 min to 10 g / 10 min, 4 g / 10 min to 6 g / 10 min, 0.1 g / 10 min to 5 g / 10 min, 0.1 g / 10 min to 4.75 g / 10 min, 0.5 g / 10 min to 4.5 g / 10 min, or any subset thereof. According to ASTM D1238, the melt flow index (I2) was measured at 190°C and 2.16 kg.

[0026] Neutralized ethylene glycol copolymers can have a content of 0.1 g / cm³. 3 Up to 2g / cm 3 0.5g / cm 3 Up to 1.5g / cm 3 0.8g / cm 3 Up to 1.2 g / cm 3 0.9g / cm 3 Up to 1.1 g / cm 3 0.9g / cm 3 Up to 1.0 g / cm 3 0.95g / cm 3 Up to 1.0 g / cm 3 0.96g / cm 3 Up to 0.98 g / cm 3 Or the density of any subset thereof. Measure density according to ASTM D792.

[0027] Suitable vinyl acetate copolymers for neutralizing polymer sheet 104 can be traded under the name SURLYN. ™ Purchased from Dow. Inc. (Midland, Mi).

[0028] See still Figure 1 The polymer sheet 104 may contain at least 50% by weight of a neutralized ethylene glycol copolymer. In an embodiment, based on the total weight of the polymer sheet 104, the polymer sheet 104 may contain at least 60% by weight, at least 75% by weight, at least 90% by weight, at least 95% by weight, at least 99% by weight, or even at least 99.9% by weight of a neutralized ethylene glycol copolymer.

[0029] The polymer sheet 104 may have a thickness of 0.01 mm to 0.51 mm. The thickness of the polymer sheet 104 should be selected such that it is thick enough to provide impact protection while remaining thin enough to ensure optical transparency. In embodiments, the polymer sheet 104 may have a thickness of 0.05 mm to 0.51 mm, 0.1 mm to 0.51 mm, 0.15 mm to 0.51 mm, 0.18 mm to 0.51 mm, 0.2 mm to 0.51 mm, 0.01 mm to 0.4 mm, 0.01 mm to 0.35 mm, 0.01 mm to 0.3 mm, 0.05 mm to 0.45 mm, 0.1 mm to 0.4 mm, 0.15 mm to 0.35 mm, 0.2 mm to 0.3 mm, or any subset thereof.

[0030] Article 108 may include a polymer sheet 104 having a first surface and a second surface; and a coating 102 in direct contact with at least a portion of the first surface. In an embodiment, there may be no additional layer, such as a primer layer, between the polymer sheet 104 and the coating 102. The coating 102 may be an air contact layer (e.g., the coating 102 may be an outer layer on which no other layer is disposed).

[0031] Coating 102 may contain acrylic materials. Without being theoretically limited, some embodiments of the acrylic materials in coating 102 can provide hardness, scratch protection, and moisture protection to the neutralized vinyl acetate copolymer material in polymer sheet 104. In embodiments, based on the total weight of coating 102, coating 102 may contain at least 80% by weight, at least 90% by weight, at least 95% by weight, at least 99% by weight, or even at least 99.9% by weight of acrylic materials.

[0032] Acrylic materials may comprise ethyl acrylate (EA) and methyl methacrylate (MMA). In embodiments, the acrylic material may also comprise hydroxyethyl methacrylate (HEMA). In embodiments, the acrylic material may also comprise itaconic acid. In embodiments, based on the total weight of the acrylic material, the acrylic material may comprise 20% to 80% by weight of ethyl acrylate (EA), such as 20% to 70% by weight, 20% to 60% by weight, 20% to 50% by weight, 20% to 40% by weight, 30% to 80% by weight, 40% to 80% by weight, 50% to 80% by weight, 60% to 80% by weight, 30% to 70% by weight, 40% to 60% by weight, or any subset thereof. In the implementation, based on the total weight of the acrylic material, the acrylic material may contain 15% to 75% methyl methacrylate, such as 15% to 65% methyl methacrylate, 15% to 55% methyl methacrylate, 15% to 45% methyl methacrylate, 15% to 35% methyl methacrylate, 25% to 75% methyl methacrylate, 35% to 75% methyl methacrylate, 45% to 75% methyl methacrylate, 55% to 75% methyl methacrylate, 25% to 65% methyl methacrylate, 35% to 55% methyl methacrylate, or any subset thereof. In the implementation scheme, based on the total weight of the acrylic material, the acrylic material may contain 0% to 20% HEMA, such as 0% to 17.5% wt%, 0% to 15% wt%, 0% to 12.5% ​​wt%, 0% to 10% wt%, 0% to 7.5% wt%, 0% to 5% wt%, 0% to 2.5% wt%, 0.1% to 20% wt%, 1% to 20% wt%, 2.5% to 20% wt%, 5% to 20% wt%, 7.5% to 20% wt%, 10% to 20% wt%, 2.5% to 17.5% wt%, 5% to 15% wt%, or any subset thereof. In the implementation, based on the total weight of the acrylic material, the acrylic material may contain 0% to 20% itaconic acid, such as 0% to 17.5% by weight, 0% to 15% by weight, 0% to 12.5% ​​by weight, 0% to 10% by weight, 0% to 7.5% by weight, 0% to 5% by weight, 0% to 2.5% by weight, 0.1% to 20% by weight, 1% to 20% by weight, 2.5% to 20% by weight, 5% to 20% by weight, 7.5% to 20% by weight, 10% to 20% by weight, 2.5% to 17.5% by weight, 5% to 15% by weight, or any subset thereof.In the embodiments, the acrylic material may contain 0.1% to 10% by weight of HEMA, 15% to 30% by weight of MMA, 15% to 30% by weight of EA and 0.1% to 10% by weight of itaconic acid.

[0033] Acrylic materials can be formed from the reaction products of acrylic emulsions (such as self-crosslinking acrylic emulsions). Self-crosslinking acrylic emulsions can be aqueous. Self-crosslinking acrylic emulsions may also contain adhesion promoters. Adhesion promoters may include amino-functionalized silanes, alkoxysilanes, or both. Alkoxysilanes may include monofunctional alkoxysilanes, difunctional alkoxysilanes, trifunctional alkoxysilanes, or combinations thereof.

[0034] Acrylic materials may have glass transition temperatures ranging from 10°C to 50°C, such as 10°C to 40°C, 10°C to 30°C, 10°C to 20°C, 20°C to 50°C, 30°C to 50°C, 40°C to 50°C, 20°C to 40°C, or any subset thereof.

[0035] Suitable commercially available acrylic materials include RHOPLEX from Dow Inc. (Midland, Michigan, USA). ™ ECO-100.

[0036] In one or more embodiments, the acrylic material may comprise butyl acrylate (BA) and methyl methacrylate (MMA). In embodiments, the acrylic material may further comprise one or more of hydroxyethyl methacrylate (HEMA), styrene, and polyisocyanate. In embodiments, based on the total weight of the acrylic material, the acrylic material may comprise 10% to 80% by weight of butyl acrylate (BA), 15% to 75% by weight of methyl methacrylate (MMA), 0% to 20% by weight of hydroxyethyl methacrylate (HEMA), 0% to 20% by weight of styrene; and 1% by weight of... % to 20% by weight of polyisocyanate. In embodiments, based on the total weight of the acrylic material, the acrylic material may contain 0% to 15% by weight, 0% to 10% by weight, 0% to 5% by weight, 1% to 20% by weight, 1% to 15% by weight, 1% to 10% by weight, 2.5% to 20% by weight, 2.5% to 10% by weight, 2.5% to 5% by weight, or any subset thereof of HEMA. In embodiments, based on the total weight of the acrylic material, the acrylic material may contain 10% to 70% by weight, 10% to 50% by weight, 10% by weight, or 10% by weight. % to 30 wt%, 10 wt% to 20 wt%, 10 wt% to 15 wt%, or any subset thereof of BA. In an embodiment, based on the total weight of the acrylic material, the acrylic material may contain 10 wt% to 75 wt%, 10 wt% to 50 wt%, 10 wt% to 30 wt%, 15 wt% to 75 wt%, 15 wt% to 50 wt%, 15 wt% to 30 wt%, 20 wt% to 75 wt%, 20 wt% to 50 wt%, 20 wt% to 30 wt%, 10 wt% to 30 wt%, or any subset thereof of MMA. In an embodiment, based on the acrylic material Based on the total weight of the material, the acrylic material may contain 0% to 20% by weight, 0% to 15% by weight, 0% to 10% by weight, 0% to 5% by weight, 1% to 20% by weight, 1% to 10% by weight, 1% to 5% by weight, 1% to 2.5% by weight, or any subset thereof, of styrene. In an embodiment, based on the total weight of the acrylic material, the acrylic material may contain 1% to 18% by weight, 1% to 15% by weight, 1% to 13% by weight, 1% to 10% by weight, 1% to 7.5% by weight, or 1% to 5% by weight of polyisocyanate.In embodiments, the acrylic material may further comprise methacrylic acid, such as 0% to 10% by weight, 0% to 7.5% by weight, 0% to 5% by weight, 0% to 2.5% by weight, 0.1% to 10% by weight, 0.1% to 5% by weight, 0.1% to 2.5% by weight, 1% to 10% by weight, 1% to 5% by weight, 1% to 2.5% by weight, or any subset thereof. In embodiments, the acrylic material may comprise 0% to 10% by weight of HEMA, 10% to 30% by weight of BA, 10% to 30% by weight of MMA, 0% to 10% by weight of styrene, and 0% to 10% by weight of methacrylic acid.

[0037] Suitable commercially available acrylic materials include RHOSHIELD from Dow Inc. (Midland, Michigan, USA). ™ 3275.

[0038] Acrylic materials can be applied in relatively thin film form, such as by spraying, dipping, or placing droplets of acrylic material onto the surface of polymer sheet 104. In an embodiment, the surface of polymer sheet 104 can be treated with corona discharge before applying the acrylic material. Although the disclosed acrylic materials exhibit relatively strong adhesion to the neutralized vinyl acetate copolymer layer even without corona discharge treatment, in some cases, the adhesion can be further improved if the neutralized vinyl acetate copolymer is corona treated prior to coating. In some cases, corona treatment will further improve the adhesion of coating 102 to the polymer sheet. Corona treatment can be performed, for example, just before coating polymer sheet 104.

[0039] The coating 102 may have a thickness of 0.2 μm to 20 μm, such as 0.2 μm to 15 μm, 0.2 μm to 10 μm, 0.2 μm to 8 μm, 0.2 μm to 6 μm, 1 μm to 20 μm, 1 μm to 15 μm, 1 μm to 10 μm, 1 μm to 8 μm, 2 μm to 20 μm, 2 μm to 15 μm, 2 μm to 10 μm, 2 μm to 8 μm, 2 μm to 6 μm, or any subset thereof.

[0040] Article 108 may have a coating equivalent of 0.3 g / cm² (gsm) to 32 gsm, such as 0.5 gsm to 32 gsm, 1 gsm to 32 gsm, 2 gsm to 32 gsm, 4 gsm to 32 gsm, 8 gsm to 32 gsm, 16 gsm to 32 gsm, 24 gsm to 32 gsm, 0.5 gsm to 25 gsm, 0.5 gsm to 20 gsm, 0.5 gsm to 15 gsm, 0.5 gsm to 10 gsm, 0.5 gsm to 5 gsm, 2 gsm to 25 gsm, 4 gsm to 20 gsm, 6 gsm to 15 gsm, or any subset thereof.

[0041] like Figure 2 As depicted, article 108 may include a polymer sheet 104, a coating 102, and an adhesive layer 202. The adhesive layer 202 may be positioned on a second surface of the polymer sheet 104, opposite to the surface of the polymer sheet 104 that contacts the coating 102. In some embodiments, article 108 may be adhered to a substrate 106 via the adhesive layer 202. In other embodiments (such as those without a substrate 106), the adhesive layer 202 may be an air contact layer.

[0042] Adhesive layer 202 may comprise a pressure-sensitive adhesive (PSA). The PSA may comprise an acrylic PSA. The acrylic PSA may comprise one or more acrylate compounds. The one or more acrylate compounds may comprise one or more of 2-ethylhexyl acrylate (2-EHA), ethyl acrylate, and butyl acrylate (BA). In an embodiment, the one or more acrylate compounds may comprise 2-ethylhexyl acrylate (2-EHA), ethyl acrylate, and butyl acrylate (BA). In an embodiment, based on the total weight of the acrylic PSA, the acrylic PSA may comprise 10% to 80% by weight of 2-ethylhexyl acrylate (2-EHA), 10% to 75% by weight of ethyl acrylate, and 0% to 20% by weight of butyl acrylate (BA). Adhesive layer 202 may comprise at least 80% by weight, such as at least 90% by weight, at least 95% by weight, at least 99% by weight, or even at least 99.9% by weight of the acrylic PSA.

[0043] Product 108 can be transparent. As used herein, transparent material is a material that allows an observer to clearly see an object on the other side. Transparency can be quantified as the clarity of a material and the haze of a material.

[0044] At the protective thickness, article 108 may have an average Gardner transparency of at least 80% as determined by ASTM D1746. In some embodiments, at the protective thickness, article 108 may have an average Gardner transparency of at least 82%, at least 84%, at least 86%, at least 88%, at least 90%, or at least 92% as determined by ASTM D1746. Alternatively, transparency may be measured as Zebedee transparency, as determined according to ASTM D1746. Article 108 may have an average Zebedee transparency of at least 10%, such as at least 15%, at least 20%, at least 25%, or at least 28%. The protective thickness can be at least 0.1 mm, such as at least 0.12 mm, at least 0.14 mm, at least 0.16 mm, at least 0.18 mm, or at least 0.2 mm, 0.01 mm to 3 mm, 0.1 mm to 3 mm, 0.1 mm to 1.5 mm, 0.1 mm to 1 mm, 0.1 mm to 0.5 mm, 0.1 mm to 0.3 mm, 0.2 mm to 0.3 mm, or any subset thereof.

[0045] At the protective thickness, article 108 may have a haze of less than 20% as measured by ASTM D1003. In some embodiments, at the protective thickness, article 108 may have a haze of less than 18%, less than 16%, less than 12%, less than 10%, less than 8%, less than 6%, less than 4%, less than 3%, or even less than 2% as measured by ASTM D1003.

[0046] At the protective thickness, article 108 may have a Spencer dart impact resistance of at least 1500 gf according to ASTM D3420. In embodiments, at the protective thickness, article 108 may have a Spencer dart impact resistance of at least 2000 gf, at least 2200 gf, at least 2400 gf, at least 2800 gf, at least 3000 gf, at least 3250 gf, at least 3500 gf, at least 3750 gf, at least 4000 gf, at least 4250 gf, at least 4500 gf, at least 4750 gf, or at least 5000 gf.

[0047] Article 108 may have a hardness of at least 5B as measured according to ASTM D3363-20. It should be understood that hardness is measured on the air-contact surface of coating 102. In embodiments, article 108 may have a hardness of at least 4B, at least 3B, at least 2B, at least B, or at least HB. On the ASTM D3363-20 hardness scale, hardness ranges from 6B (softest) to 9H (hardest).

[0048] Article 108 may primarily comprise a polymer sheet 104 and a coating 102. In an embodiment, the polymer sheet 104 and the coating 102 may constitute at least 95% of the thickness of article 108, such as at least 98%, at least 99%, or even 99.9%. In an embodiment, the polymer sheet 104, the coating 102, and the adhesive layer 202 may constitute at least 95% of the thickness of article 108, such as at least 98%, at least 99%, or even 99.9%.

[0049] In some embodiments, the substrate 100 and article 108 may be free of a primer layer. In some embodiments, article 108 may include a primer layer of less than 1% by weight, such as less than 0.5% by weight, less than 0.1% by weight, less than 0.01% by weight, or even less than 0.001% by weight. The primer layer may contain an epoxy material. Without being theoretically limited, it is believed that the primer layer can reduce the transparency of article 108.

[0050] The method of manufacturing article 108 is not particularly limited, because each layer of article 108 can be manufactured by any suitable method known or not yet discovered by those skilled in the art. For example, according to the embodiments, the individual layers and article 108 can be cast, extruded, co-extruded, laminated, etc. by various methods (e.g., blown film, mechanical stretching, etc.), including orientation (uniaxial or biaxial).

[0051] The substrate 106 may include glass. In an embodiment, the substrate 106 may be a cover glass for an electronic device.

[0052] Test methods

[0053] Haze

[0054] Haze was measured according to ASTM D1003.

[0055] Gardner transparency

[0056] Gardner's transparency was measured according to ASTM D1746.

[0057] ZebedeeTransparency

[0058] Zebedee transparency was measured according to ASTM D1746.

[0059] Melt flow index (I2)

[0060] The melt flow index I2 was measured at 190°C and 2.16 kg according to ASTM D1238.

[0061] density

[0062] Density was measured according to ASTM D792.

[0063] Spencer's Dart Impact

[0064] Spencer's resistance to dart impact was measured according to ASTM D3420.

[0065] hardness

[0066] Hardness was measured according to ASTM D3363-20.

[0067] Glass transition temperature

[0068] The glass transition temperature is measured according to ASTM D3418.

[0069] aspect

[0070] According to a first aspect, an article may include a polymer sheet comprising a first surface and a second surface opposite to the first surface, the polymer sheet comprising a neutralized ethylene copolymer material containing carboxylic acid groups, wherein the carboxylic acid groups of the ethylene copolymer are at least partially neutralized by metal ions; and a coating that is in direct contact with at least a portion of the first surface of the polymer sheet, the coating comprising an acrylic material, wherein the coating is an air contact layer.

[0071] According to the second aspect, in conjunction with the first aspect, the combination of polymer sheet and coating can account for at least 95% of the thickness of the article.

[0072] According to the third aspect, in conjunction with the first or second aspect, the polymer sheet may have a thickness that is measured as the distance between the first surface and the second surface, and the thickness may be from 0.01 mm to 0.51 mm.

[0073] According to the fourth aspect, in conjunction with any one of aspects 1 to 3, the ratio of the surface area of ​​the first surface to the thickness of the article may be at least 100,000 mm.

[0074] According to the fifth aspect, in conjunction with any one of aspects 1 to 4, the coating may have a thickness of 2 μm to 8 μm.

[0075] According to the sixth aspect, in conjunction with any one of aspects 1 to 5, the article may further include an adhesive layer that is in direct contact with the second surface of the polymer sheet.

[0076] According to the seventh aspect, in conjunction with any one of aspects 1 to 6, the neutralized vinyl acid copolymer material may contain 1% to 35% by weight of comonomers, including carbon monoxide, sulfur dioxide, acrylonitrile, maleic anhydride, maleic acid diester, maleic acid, maleic acid monoester, itaconic acid, fumaric acid, fumaric acid monoester, salts of these acids, glycidyl acrylate, glycidyl methacrylate and glycidyl vinyl ether, methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, amyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate and butyl methacrylate, amyl methacrylate or combinations thereof.

[0077] According to the eighth aspect, in conjunction with any of aspects 1 to 7, the neutralized ethylene-acrylic acid copolymer material can be an ethylene-methacrylic acid copolymer, wherein the methacrylic acid groups of the copolymer are at least partially neutralized by sodium ions.

[0078] According to the ninth aspect, in conjunction with any one of aspects 1 to 8, the neutralized ethylene copolymer material may comprise 15% to 30% by weight of acrylic acid or methacrylic acid copolymer units and 70% to 85% by weight of ethylene copolymer units based on the total weight of the neutralized acid copolymer; and about 40% to about 70% of the carboxylic acid groups of the neutralized acid copolymer are neutralized to carboxylates containing sodium cations.

[0079] According to aspect 10, in conjunction with any of aspects 1 to 9, the neutralized ethylene copolymer material may have a melt flow index (I2) of 0.9 g / 10 min to 13 g / 10 min as measured by ASTM D1238.

[0080] According to the eleventh aspect, in conjunction with any one of aspects 1 to 10, the acrylic material may comprise 20% to 80% by weight of ethyl acrylate (EA), 15% to 75% by weight of methyl methacrylate (MMA), 0% to 20% by weight of hydroxyethyl methacrylate (HEMA), and 0% to 20% by weight of itaconic acid, based on the total weight of the acrylic material.

[0081] According to the twelfth aspect, in conjunction with any one of aspects 1 to 11, the acrylic material may comprise 10% to 80% by weight of butyl acrylate (BA), 15% to 75% by weight of methyl methacrylate (MMA), 0% to 20% by weight of hydroxyethyl methacrylate (HEMA), 0% to 20% by weight of styrene, and 1% to 20% by weight of polyisocyanate, based on the total weight of the acrylic material.

[0082] According to aspect thirteen, in conjunction with any of aspects 1 to 12, the article can be a screen protector.

[0083] According to the fourteenth aspect, a coated substrate may include: a transparent substrate; and an article of article positioned on at least a portion of a first surface of the substrate, the article of article comprising: a polymer sheet including a first surface and a second surface opposite to the first surface, the polymer sheet comprising a neutralized ethylene copolymer material containing carboxylic acid groups, wherein the carboxylic acid groups of the ethylene copolymer are at least partially neutralized by metal ions; and a coating in direct contact with at least a portion of the first surface of the polymer sheet, the coating comprising an acrylic material, wherein the coating is an air contact layer.

[0084] According to aspect 15, in conjunction with aspect 14, the substrate may include glass.

[0085] Example

[0086] The following examples are provided to illustrate the implementation schemes described in this disclosure, and these examples are not intended to limit the scope of this disclosure or its appended claims.

[0087] Material

[0088] PS-1 is a neutralized ethylene glycol copolymer as described herein, with a melt flow rate (190°C / 2.16 kg) of 4.5 g / 10 min (ASTM D1238) and a density of 0.970 g / cc (ASTM D792). The production of PS-1 is described in U.S. Patent 3,264,272, the entire contents of which are incorporated herein by reference.

[0089] PS-2 is a neutralized ethylene glycol copolymer as described herein, with a melt flow rate (190°C / 2.16 kg) of 1.8 g / 10 min (ASTM D1238) and a density of 0.950 g / cc (ASTM D792). The production of PS-2 is described in U.S. Patent 3,264,272, the entire contents of which are incorporated herein by reference.

[0090] PS-3 is a neutralized ethylene glycol copolymer as described herein, with a melt flow rate (190°C / 2.16 kg) of 0.7 g / 10 min (ASTM D1238) and a density of 0.970 g / cc (ASTM D792). PS-3 is a highly branched, neutralized ethylene glycol copolymer produced via random radical polymerization. The production of PS-3 is described in U.S. Patent 3,264,272, the entire contents of which are incorporated herein by reference.

[0091] PS-4 is a neutralized ethylene glycol copolymer as described herein, with a melt flow rate (190°C / 2.16 kg) of 4.5 g / 10 min (ASTM D1238) and a density of 0.970 g / cc (ASTM D792). The production of PS-4 is described in U.S. Patent 3,264,272, the entire contents of which are incorporated herein by reference.

[0092] Coating-1 is an acrylic material formed from a water-based acrylic latex, having 42% solids and a hydroxyl equivalent of 2600, as provided. Once cured, the acrylic material of Coating-1 contains 10% to 80% by weight of butyl acrylate (BA), 15% to 75% by weight of methyl methacrylate (MMA), 0% to 20% by weight of hydroxyethyl methacrylate (HEMA), and 0% to 20% by weight of styrene, based on the total weight of the acrylic material.

[0093] Coating-2 is an acrylic material formed from a self-crosslinking aqueous emulsion. Once cured, the acrylic material of Coating-2 contains 20% to 80% by weight of ethyl acrylate (EA), 15% to 75% by weight of methyl methacrylate (MMA), 0% to 20% by weight of hydroxyethyl methacrylate (HEMA), and 0% to 20% by weight of itaconic acid, based on the total weight of the acrylic material.

[0094] CR 9-101 is an isocyanate co-reactant, commercially available from Dow Inc. (Midland, MI).

[0095] For the following examples, various coated and uncoated polymer sheets were prepared. Sheets with a thickness of 1 to 7 mils were produced by cast extrusion, and sheets with a thickness of 8 to 10 mils were produced by compression molding. The presence or absence of coating is recorded in the table below.

[0096] Example 1

[0097] Gardner transparency (ASTM D1746), haze (ASTM D1003), and impact resistance (ASTM D3420) were tested for each membrane in the test. Polyethylene terephthalate (PET) No. 92 was included as a comparative example. The results are shown in Table 1.

[0098] Table 1

[0099]

[0100] As can be seen from Table 1, compared to PET sheets, polymer sheets PS-1 to PS-4 generally have improved haze, Gardner transparency, and impact resistance.

[0101] Example 2

[0102] Four polymer sheets were prepared using acrylic-based materials coated with four grades of neutralized vinyl acetate copolymer materials (PS-1 to PS-4), and a comparative sheet of polyethylene terephthalate (PET). The polymer sheets were manufactured using a compression molding process. Resin was placed in a heated, open mold cavity, and then the mold was closed under pressure (using a hydraulic press), allowing the material to flow and completely fill the cavity. Pressure was then maintained until the material cured.

[0103] The polymer sheets for PS-1, PS-2, PS-3 and PS-4 are 0.2 mm thick.

[0104] Polymer sheets were coated with acrylic materials. Prior to coating, the polymer sheets (PS-1 to PS-4) were treated with corona discharge. In the first set of experiments, the PET film was not corona treated. Specifically, the polymer sheets were coated with Paint-1, Paint-2, and Paint-1 / / CR 9-101 (100:7 mixing ratio) via Meyer rod coating. After coating the polymer sheets with wet paint, the samples were placed in an oven at 70°C for 3 minutes to remove volatiles. The coating weight of the dried coatings was measured to be 3.6 lb / ream for Paint-1 / CR 9-101 and 2.98 lb / ream (3000 sq ft) for Paint-2. The dried samples were removed from the oven and allowed to reach room temperature before testing at 77°C. Curing occurs at 50% relative humidity.

[0105] The hardness of the samples was measured using the ASTM D3363-20 test method with a pencil, and the results are shown in Table 2. The pencil hardness ranges from 6B (softest), 5B, 5B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H to 9H (hardest).

[0106] Table 2

[0107]

[0108] As can be seen from Table 2, PS-1 and PS-4, which were already coated with Coating-1 / CR 9-101 or Coating-2, achieved the best results in terms of hardness.

[0109] The haze, transparency, dart drop, and abrasion of coated and uncoated PS-1 samples were tested. Comparative examples were also prepared using PET #92. The PS-1 samples had a standard thickness of 8 mils (0.232 mm). The PET samples had a standard thickness of 1 mil (0.0254 mm). Thickness T1 is the measured thickness for haze, Gardner transparency, and dart drop measurements. Thickness T2 is the measured thickness for Zebedee transparency and Taber abrasion measurements.

[0110] The results are shown in Table 3.

[0111] Table 3

[0112]

[0113] Haze was measured using the standard test method for haze and transmittance of transparent plastics, ASTM D1003. Table 3 shows that Coating-2 had the least impact on the haze of the PS-4 film, and even reduced the haze of the PET film. On the other hand, samples coated with Coating-1 showed a 2.7 to 3.5 times increase in haze compared to uncoated samples. In each case, the haze of the PET sample was higher than that of the PS-1.

[0114] Transparency was measured using the standard test method for transparency of plastic sheets, ASTM D1746, with the Gardner and Zebedee meters. This test method covers the measurement of transparency of plastic sheets based on conventional transmittance. As shown in Table 3, the transparency results using the Gardner and Zebedee meters are consistent with the haze results, where the coating with Paint-2 improved the transparency of the PET film and maintained or slightly improved the transparency of the PS-4 film, while the coating containing Paint-1 / CR 9-101 reduced the transparency by 3.5% to 4.3%.

[0115] In addition to optical properties, two of the most important mechanical properties for the application were measured: impact resistance and abrasion resistance. Impact resistance was measured using ASTM D3420, "Resistance to Pendulum Impact of Plastic Films," and abrasion resistance was measured using ASTM D4060, "Abrasion Resistance of Organic Coatings in Taber Mills." As can be seen from Table 3, the polymer sheet containing the neutralized vinyl acetate copolymer material again exhibited the best abrasion resistance and impact resistance.

[0116] While specific embodiments of the invention have been described and illustrated, it will be apparent to those skilled in the art that many other changes and modifications can be made without departing from the spirit and scope of the invention. Therefore, it is intended that all such changes and modifications falling within the scope of the invention be covered in the appended claims.

Claims

1. An article comprising: A polymer sheet comprising a first surface and a second surface opposite to the first surface, the polymer sheet comprising a neutralized ethylene glycol copolymer containing carboxylic acid groups, wherein the carboxylic acid groups of the ethylene glycol copolymer are at least partially neutralized by metal ions; as well as A coating that is in direct contact with at least a portion of the first surface of the polymer sheet, the coating comprising an acrylic material, wherein the coating is an air contact layer.

2. The article of any preceding claim, wherein the combination of the polymer sheet and the coating accounts for at least 95% of the thickness of the article.

3. The article of manufacture according to any of the preceding claims, wherein the polymer sheet has a thickness measured as the distance between the first surface and the second surface, and the thickness is from 0.01 mm to 0.51 mm.

4. The article of claim 3, wherein the ratio of the surface area of ​​the first surface to the thickness of the article is at least 100,000 mm.

5. The article of manufacture according to any of the preceding claims, wherein the coating has a thickness of 2 μm to 8 μm.

6. The article of manufacture according to any of the preceding claims, wherein the article of manufacture further comprises an adhesive layer in direct contact with the second surface of the polymer sheet.

7. The article according to any of the preceding claims, wherein the neutralized vinyl copolymer material comprises 1% to 35% by weight of a comonomer, said comonomer including carbon monoxide, sulfur dioxide, acrylonitrile, maleic anhydride, maleic acid diester, maleic acid, maleic acid monoester, itaconic acid, fumaric acid, fumaric acid monoester, salts of these acids, glycidyl acrylate, glycidyl methacrylate and glycidyl vinyl ether, methyl acrylate, ethyl acrylate, isopropyl acrylate, butyl acrylate, amyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate and butyl methacrylate, amyl methacrylate or combinations thereof.

8. The article according to any of the preceding claims, wherein the neutralized ethylene copolymer material is an ethylene methacrylic acid copolymer, wherein the methacrylic acid groups of the copolymer are at least partially neutralized by sodium ions.

9. The article according to any of the preceding claims, wherein the neutralized ethylene copolymer material comprises 15% to 30% by weight of acrylic acid or methacrylic acid copolymer units and 70% to 85% by weight of ethylene copolymer units based on the total weight of the neutralized acid copolymer; and approximately 40% to approximately 70% of the carboxylic acid groups of the neutralized acid copolymer are neutralized to carboxylates containing sodium cations.

10. The article according to any of the preceding claims, wherein the neutralized ethylene copolymer material has a melt flow index (I2) of 0.9 g / 10 min to 13 g / 10 min as measured by ASTM D1238.

11. The article according to any of the preceding claims, wherein the acrylic material comprises 20% to 80% by weight of ethyl acrylate (EA), 15% to 75% by weight of methyl methacrylate (MMA), 0% to 20% by weight of hydroxyethyl methacrylate (HEMA), and 0% to 20% by weight of itaconic acid based on the total weight of the acrylic material.

12. The article according to any of the preceding claims, wherein the acrylic material comprises 10% to 80% by weight of butyl acrylate (BA), 15% to 75% by weight of methyl methacrylate (MMA), 0% to 20% by weight of hydroxyethyl methacrylate (HEMA), 0% to 20% by weight of styrene, and 1% to 20% by weight of polyisocyanate based on the total weight of the acrylic material.

13. The article of manufacture according to any of the preceding claims, wherein the article of manufacture is a screen protector.

14. A coating substrate, the coating substrate comprising: Transparent substrate; as well as Article, said article being positioned on at least a portion of a first surface of said substrate, said article comprising: A polymer sheet comprising a first surface and a second surface opposite to the first surface, the polymer sheet comprising a neutralized ethylene glycol copolymer containing carboxylic acid groups, wherein the carboxylic acid groups of the ethylene glycol copolymer are at least partially neutralized by metal ions; as well as A coating that is in direct contact with at least a portion of the first surface of the polymer sheet, the coating comprising an acrylic material, wherein the coating is an air contact layer.

15. The coating substrate of claim 14, wherein the substrate comprises glass.

Images