Polymer structures and their applications

Abstract

The present invention provides a polymer structure and applications thereof. The polymer structure comprises a substrate and a light-shielding layer covering at least a part of the surface of the substrate, wherein the substrate comprises a first polymer, the light-shielding layer comprises a second polymer, and the second polymer comprises a structural unit derived from a first ultraviolet light absorber, and the light-shielding layer has a thickness of 1 micrometer to 200 micrometers, the first ultraviolet light absorber being a multifunctional reactive ultraviolet light absorber.

Description

Technical Field

[0001] This invention relates to a polymer structure, and more particularly to a thermoplastic polyurethane structure having a thin ultraviolet light shielding layer. Background Technology

[0002] Polyurethane is an important polymer formed by the polymerization of polyols and isocyanates. By adjusting the proportions of the raw materials, materials with desired mechanical properties can be manufactured, including abrasion resistance, temperature resistance, flexibility, and elongation. Polyurethane is widely used in various materials, such as coatings, elastomers, foaming materials, adhesives, and sealants. Generally, polyurethane can be classified into aliphatic polyurethane and aromatic polyurethane based on the presence or absence of aromatic rings in its structure. Aromatic polyurethane has superior physicochemical properties and processability compared to aliphatic polyurethane, but the problem of weather yellowing in aromatic polyurethane has always been a difficult problem to solve in industry.

[0003] US 7,910,642 B2 proposed using additive ultraviolet absorbing agent (UVA) and hindered amine light stabilizer (HALS) to try to solve the above problems. However, due to the compatibility issues between additive UVA and aromatic polyurethane, there is an upper limit to the amount of additive UVA that can be added, which makes it impossible to significantly improve the anti-yellowing effect. Therefore, the yellowing problem cannot be completely solved, and the application of aromatic polyurethane, especially in outdoor products, has been limited for a long time. Summary of the Invention

[0004] To protect polymer materials from the effects of ultraviolet (UV) radiation, current technologies involve directly adding or reacting UV absorbers into the polymer. This method results in a uniform distribution of UV-absorbing components throughout the polymer. Therefore, even if only the surface-level UV absorbers are effective, a significant amount of UV absorber must be added to the entire polymer to ensure sufficient UV protection. However, this large-scale addition not only increases costs but can also negatively impact the polymer's physicochemical properties. In particular, for high-value transparent or white polymers (such as thermoplastic polyurethane), excessive UV absorption significantly affects the color, reducing commercial value. This explains why aromatic polyurethanes, despite their superior physicochemical properties and processability compared to aliphatic polyurethanes, are often excluded from outdoor applications due to their yellowing and weathering problems.

[0005] In view of the above-mentioned technical problems, the present invention provides an innovative approach by forming a thin ultraviolet light shielding layer on the surface of a polymer material to provide a composite polymer material that can simultaneously achieve the advantages of effective UV resistance, low cost, and minimal impact on the physicochemical properties of the polymer material, thereby solving the long-standing bottleneck of aromatic polyurethane in the application of outdoor products in industry.

[0006] Specifically, one object of the present invention is to provide a polymer structure comprising a substrate and a light-shielding layer covering at least a portion of the surface of the substrate, wherein the substrate comprises a first polymer, the light-shielding layer comprises a second polymer, and the second polymer comprises structural units derived from a first ultraviolet light absorber, and the light-shielding layer has a thickness of 1 micrometer to 200 micrometers, wherein the first ultraviolet light absorber is a multifunctional reactive ultraviolet light absorber.

[0007] In some embodiments of the present invention, the light-shielding layer has a thickness of 2 micrometers to 100 micrometers.

[0008] In some embodiments of the present invention, the first ultraviolet light absorber has the following chemical formula (1):

[0009] [Chemical Formula (1)]

[0010]

[0011] In chemical formula (1), R1 is H or Cl.

[0012] In some embodiments of the present invention, the content of the first ultraviolet absorber is from 0.5% to 45% by weight, based on the total weight of the second polymer.

[0013] In some embodiments of the present invention, the first polymer and the second polymer are each independently selected from the group consisting of: polyurethane, polyester, polycarbonate, epoxy resin, amine resin, polyamide, polyimide, polypropylene, polyethylene, liquid crystal polymer, acrylonitrile-butadiene-styrene copolymer, polyoxymethylene, polystyrene, and the aforementioned composites.

[0014] In some embodiments of the present invention, the first polymer and the second polymer are each independently polyurethane.

[0015] In some embodiments of the present invention, the polyurethane is thermoplastic polyurethane.

[0016] In some embodiments of the present invention, the first polymer is an aromatic polyurethane.

[0017] In some embodiments of the present invention, the light-shielding layer at least covers the light-receiving surface of the substrate.

[0018] In some embodiments of the present invention, the polymer structure has a visible light transmittance of 65% or higher.

[0019] In some embodiments of the present invention, the substrate and the light-shielding layer each independently comprise additives selected from the group consisting of: defoamers, leveling and wetting agents, thickeners, dispersants, micronized waxes, matting agents, antibacterial agents, metal oxide light-shielding agents, light stabilizers, heat stabilizers, non-reactive ultraviolet absorbers, monofunctional reactive ultraviolet absorbers, polyfunctional reactive ultraviolet absorbers different from the first ultraviolet absorber, antioxidants, fillers, flame retardants, plasticizers, dyes, pigments, brighteners, antistatic agents, fluorescent whitening agents, antioxidants, metal stabilizers, acid absorbers, anti-hydrolysis agents, waxes, and combinations thereof.

[0020] Another object of the present invention is to provide the use of the above-described polymer structure in the preparation of articles that can resist ultraviolet light.

[0021] In some embodiments of the present invention, the article is selected from the group consisting of: transparent covers, components of electronic products, peripheral materials of solar panels, components of vehicles, clothing materials, optical articles, building components, wind power generation components, agricultural components, military industrial articles, external viewing surfaces of displays, films, sheets, and explosion-proof panels.

[0022] In some embodiments of the present invention, the article is selected from the group consisting of: vehicle cladding, lampshades, housings of mobile devices, vehicle housings, automotive lights, surface materials for vehicle interiors, windshields, side window glass, windows, doors, filters, clothing, trousers, coats, shoes, optical lenses, optical components, photochromic lenses, contact lenses, roofing films, roof tiles, roofing linings, eaves, wall materials, flooring materials, road construction components, pipe materials, signs, sunshades, greenhouse covering films, backlights, windmill components, transparent bodies for aircraft, radar radomes, explosion-proof glass, bulletproof panels, transparent screen films, conductive films, microwave absorbing films, heat transfer films, packaging films, and low-resistance films.

[0023] To make the above-mentioned objectives, technical features and advantages of the present invention more apparent and understandable, the following detailed description is provided with reference to some specific embodiments. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the polymer structure according to one embodiment of the present invention.

[0025] Explanation of reference numerals in the attached figures

[0026] 10: Polymer Structure

[0027] 11: Light-shielding layer

[0028] 12: Substrate Detailed Implementation

[0029] The following describes some specific embodiments of the present invention; however, the present invention can be practiced in many different forms and the scope of protection of the present invention should not be limited to the specific embodiments described.

[0030] Unless otherwise stated, the terms “a,” “the,” and similar terms used in this specification and claims shall be understood to include both singular and plural forms.

[0031] Unless otherwise stated, the terms “first,” “second,” and similar terms used in this specification and claims are used only to distinguish the described components or ingredients and have no special meaning in themselves, nor are they used to indicate a sequence.

[0032] Unless otherwise stated, in this specification and claims, the term "non-reactive ultraviolet absorber" refers to a compound that absorbs ultraviolet light without any reactive functional groups; the term "monofunctional reactive ultraviolet absorber" refers to a compound that absorbs ultraviolet light with one reactive functional group; and the term "polyfunctional reactive ultraviolet absorber" refers to a compound that absorbs ultraviolet light with two or more reactive functional groups. Examples of such reactive functional groups include, but are not limited to, hydroxyl, carboxyl, carbonyl, amino, cyano, sulfonyl, phenyl, and nitro groups.

[0033] Unless otherwise stated, in this specification and claims, the term "light-receiving surface" means a surface that is exposed to light.

[0034] The advantage of this invention compared to the prior art lies in providing a polymer structure with a thin ultraviolet (UV) light shielding layer, particularly a polymer structure comprising a thermoplastic aromatic polyurethane as a substrate. The UV light shielding layer prevents yellowing of the polymer substrate, such as the thermoplastic aromatic polyurethane, and the thickness of the UV light shielding layer is controlled within a certain range to reduce its adverse effects on the appearance and light transmittance of the thermoplastic aromatic polyurethane structure. The following provides a detailed description of the polymer structure of this invention and its applications.

[0035] 1. Polymer structure

[0036] Figure 1 This is a schematic diagram of the polymer structure according to one embodiment of the present invention. Figure 1As shown, the polymer structure 10 of the present invention includes a substrate 12 and a light-shielding layer 11 covering at least a portion of the surface of the substrate. In some embodiments of the present invention, the light-shielding layer 11 at least partially covers the light-receiving surface of the substrate 12 to provide an ultraviolet light shielding effect. In a preferred embodiment of the present invention, the light-shielding layer 11 completely covers the light-receiving surface of the substrate 12, or completely covers both the light-receiving and non-light-receiving surfaces of the substrate 12.

[0037] 1.1. Substrate

[0038] In the polymer structure of the present invention, the substrate comprises, is primarily composed of, or is composed of the first polymer. In some embodiments of the present invention, the substrate is formed from the first polymer and, if desired, additives.

[0039] The type of the first polymer is not particularly limited, and examples include, but are not limited to, polyurethane, polyester, polycarbonate, epoxy resin, amino resin, polyamide, polyimide, polypropylene, polyethylene, liquid crystal polymer, acrylonitrile-butadiene-styrene copolymer, polyoxymethylene, polystyrene, and the aforementioned composites. Polyurethane includes, but is not limited to, acrylic-modified polyurethane and thermoplastic polyurethane, and thermoplastic polyurethane may be thermoplastic aromatic polyurethane or thermoplastic aliphatic polyurethane. An example of polyimide is colorless polyimide (CPI). Examples of polyester include, but are not limited to, polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polypropylene terephthalate (PTT), thermoplastic polyester elastomer (TPEE), and polyarylate (PAR). In some embodiments of the invention, the first polymer is polyurethane, specifically thermoplastic polyurethane, and more specifically thermoplastic aromatic polyurethane.

[0040] Additives, when needed, can adaptively improve the processability of a substrate or impart specific functions. Examples of additives include, but are not limited to, defoamers, leveling and wetting agents, thickeners, dispersants, micronized waxes, matting agents, antibacterial agents, metal oxide light-blocking agents, light stabilizers, heat stabilizers, non-reactive UV absorbers, monofunctional reactive UV absorbers, multifunctional reactive UV absorbers (different from the primary UV absorber), antioxidants, fillers, flame retardants, plasticizers, dyes, pigments, brighteners, antistatic agents, fluorescent whitening agents, antioxidants, metal stabilizers, acid scavengers, hydrolysis inhibitors, and waxes. The aforementioned additives can be used alone or in combination. One example of a light stabilizer is a hindered amine light stabilizer (HALS), a compound with an amine group that can capture free radicals to inhibit photodegradation, typically a derivative of tetramethylpiperidine.

[0041] There are no particular limitations on the content of the additives, as long as the content is sufficient to achieve the desired function. In some embodiments of the present invention, the substrate comprises a thermoplastic aromatic polyurethane as the first polymer and HALS, and the content of HALS can be from 0.01 parts by weight to 5 parts by weight per 100 parts by weight of the first polymer, for example 0.01 parts by weight, 0.02 parts by weight, 0.03 parts by weight, 0.04 parts by weight, 0.05 parts by weight, 0.06 parts by weight, 0.07 parts by weight, 0.08 parts by weight, 0.09 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.3 parts by weight, 0.4 parts by weight, 0.5 parts by weight, 0.6 parts by weight, 0.7 parts by weight, 0.8 parts by weight, 0.9 parts by weight, 1 part by weight, 1.1 parts by weight, 1.2 parts by weight, 1.3 parts by weight, 1.4 parts by weight, 1.5 parts by weight, 1 0.6 parts by weight, 1.7 parts by weight, 1.8 parts by weight, 1.9 parts by weight, 2 parts by weight, 2.1 parts by weight, 2.2 parts by weight, 2.3 parts by weight, 2.4 parts by weight, 2.5 parts by weight, 2.6 parts by weight, 2.7 parts by weight, 2.8 parts by weight, 2.9 parts by weight, 3 parts by weight, 3.1 parts by weight, 3.2 parts by weight, 3.3 parts by weight, 3.4 parts by weight, 3.5 parts by weight, 3.6 parts by weight, 3.7 parts by weight, 3.8 parts by weight, 3.9 parts by weight, 4 parts by weight, 4.1 parts by weight, 4.2 parts by weight, 4.3 parts by weight, 4.4 parts by weight, 4.5 parts by weight, 4.6 parts by weight, 4.7 parts by weight, 4.8 parts by weight, 4.9 parts by weight, or 5 parts by weight, or within the range of any two of the above values.

[0042] In the polymer structure of this invention, the thickness of the substrate is not particularly limited. For example, it can range from 1 micrometer to 150 millimeters, such as 1 micrometer, 5 micrometer, 10 micrometer, 15 micrometer, 20 micrometer, 25 micrometer, 30 micrometer, 35 micrometer, 40 micrometer, 45 micrometer, 50 micrometer, 55 micrometer, 60 micrometer, 65 micrometer, 70 micrometer, 75 micrometer, 80 micrometer, 85 micrometer, 90 micrometer, 95 micrometer, 100 micrometer, 150 micrometer, 200 micrometer, 250 micrometer, 300 micrometer, 350 micrometer, 400 micrometer, 450 micrometer, 500 micrometer, 550 micrometer, 600 micrometer, 650 micrometer, 700 micrometer, 750 micrometer, 800 micrometer, 850 micrometer. The values ​​are: meter, 900 micrometer, 950 micrometer, 1 millimeter, 5 millimeter, 10 millimeter, 15 millimeter, 20 millimeter, 25 millimeter, 30 millimeter, 35 millimeter, 40 millimeter, 45 millimeter, 50 millimeter, 55 millimeter, 60 millimeter, 65 millimeter, 70 millimeter, 75 millimeter, 80 millimeter, 85 millimeter, 90 millimeter, 95 millimeter, 100 millimeter, 105 millimeter, 110 millimeter, 115 millimeter, 120 millimeter, 125 millimeter, 130 millimeter, 135 millimeter, 140 millimeter, 145 millimeter, or 150 millimeter, or within the range of any two of the above values, but the present invention is not limited thereto.

[0043] Due to the thin light-shielding layer, the polymer structure of this invention eliminates the need to add a large amount of ultraviolet light-absorbing components to the substrate, thereby better preserving the original physicochemical properties of the substrate, especially its original color or transparency. Therefore, in some embodiments of this invention, the polymer structure as a whole can have a visible light transmittance of 65% or higher, for example, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%, or 100%. In some embodiments of this invention, the polymer structure can have a visible light transmittance of 95% or higher.

[0044] 1.2. Light-shielding layer

[0045] In the polymer structure of the present invention, the light-shielding layer comprises, is primarily composed of, or is composed of the second polymer, and the second polymer comprises structural units derived from the first ultraviolet light absorber. In some embodiments of the present invention, the light-shielding layer is formed from the second polymer and, as desired, additives.

[0046] In the polymer structure of this invention, the thickness of the light-shielding layer can be from 1 micrometer to 200 micrometers, for example, 1 micrometer, 2 micrometers, 3 micrometers, 4 micrometers, 5 micrometers, 6 micrometers, 7 micrometers, 8 micrometers, 9 micrometers, 10 micrometers, 11 micrometers, 12 micrometers, 13 micrometers, 14 micrometers, 15 micrometers, 16 micrometers, 17 micrometers, 18 micrometers, 19 micrometers, 20 micrometers, 21 micrometers, 22 micrometers, 23 micrometers, 24 micrometers, 25 micrometers, 26 micrometers, 27 micrometers, 28 micrometers, 29 micrometers, 30 micrometers, 31 micrometers, 32 micrometers, 33 micrometers, 34 micrometers, 35 micrometers, 36 micrometers, 37 micrometers, 38 micrometers, 39 micrometers, 40 micrometers, 41 micrometers, 42 micrometers, 43 micrometers, 44 micrometers, 45 micrometers. 46 micrometers, 47 micrometers, 48 ​​micrometers, 49 micrometers, 50 micrometers, 51 micrometers, 52 micrometers, 53 micrometers, 54 micrometers, 55 micrometers, 56 micrometers, 57 micrometers, 58 micrometers, 59 micrometers, 60 micrometers, 61 micrometers, 62 micrometers, 63 micrometers, 64 micrometers, 65 micrometers, 66 micrometers, 67 micrometers, 68 micrometers, 69 micrometers, 70 micrometers, 71 micrometers, 72 micrometers, 73 micrometers, 74 micrometers, 75 micrometers, 76 micrometers, 77 micrometers, 78 micrometers, 79 micrometers, 80 micrometers, 81 micrometers, 82 micrometers, 83 micrometers, 84 micrometers, 85 micrometers, 86 micrometers, 87 micrometers, 88 micrometers, 89 micrometers, 90 micrometers, 91 micrometers, 92 micrometers, 93 micrometers, 94 micrometers, 95 micrometers 96 micrometers, 97 micrometers, 98 micrometers, 99 micrometers, 100 micrometers, 101 micrometers, 102 micrometers, 103 micrometers, 104 micrometers, 105 micrometers, 106 micrometers, 107 micrometers, 108 micrometers, 109 micrometers, 110 micrometers, 111 micrometers, 112 micrometers, 113 micrometers, 114 micrometers, 115 micrometers, 116 micrometers, 117 micrometers, 118 micrometers, 119 micrometers, 120 micrometers, 121 micrometers, 122 micrometers, 123 micrometers, 124 micrometers, 125 micrometers, 126 micrometers, 127 micrometers, 128 micrometers, 129 micrometers, 130 micrometers, 131 micrometers, 132 micrometers, 133 micrometers, 134 micrometers, 135 micrometers, 136 micrometers, 137 micrometers, 13 8 micrometers, 139 micrometers, 140 micrometers, 141 micrometers, 142 micrometers, 143 micrometers, 144 micrometers, 145 micrometers, 146 micrometers, 147 micrometers, 148 micrometers, 149 micrometers, 150 micrometers, 151 micrometers, 152 micrometers, 153 micrometers, 154 micrometers, 155 micrometers, 156 micrometers, 157 micrometers, 158 micrometers, 159 micrometers, 160 micrometers, 161 micrometers, 162 micrometers, 163 micrometers, 164 micrometers, 165 micrometers, 166 micrometers, 167 micrometers, 168 micrometers, 169 micrometers, 170 micrometers, 171 micrometers, 172 micrometers, 173 micrometers, 174 micrometers, 175 micrometers, 176 micrometers, 177 micrometers, 178 micrometers, 179 micrometersThe light-shielding layer has a thickness of 180 micrometers, 181 micrometers, 182 micrometers, 183 micrometers, 184 micrometers, 185 micrometers, 186 micrometers, 187 micrometers, 188 micrometers, 189 micrometers, 190 micrometers, 191 micrometers, 192 micrometers, 193 micrometers, 194 micrometers, 195 micrometers, 196 micrometers, 197 micrometers, 198 micrometers, 199 micrometers, or 200 micrometers, or a range consisting of any two of the above values. In a preferred embodiment of the invention, the light-shielding layer has a thickness of 2 micrometers to 100 micrometers. When the thickness of the light-shielding layer is within the above range, the reduction in transparency caused by the high concentration of ultraviolet light absorber can be ignored, thereby maintaining the overall visible light transmittance of the polymer structure.

[0047] The type of the second polymer is not particularly limited, and examples include, but are not limited to, polyurethane, polyester, polycarbonate, epoxy resin, amino resin, polyamide, polyimide, polypropylene, polyethylene, liquid crystal polymer, acrylonitrile-butadiene-styrene copolymer, polyoxymethylene, polystyrene, and composites thereof. Polyurethane includes, but is not limited to, acrylic-modified polyurethane and thermoplastic polyurethane, and thermoplastic polyurethane may be thermoplastic aromatic polyurethane or thermoplastic aliphatic polyurethane. An example of polyimide is CPI. Examples of polyester include, but are not limited to, PET, PBT, PTT, TPEE, and PAR. In some embodiments of the invention, the second polymer is polyurethane, specifically thermoplastic polyurethane, and more specifically thermoplastic aromatic polyurethane.

[0048] The first ultraviolet absorber is a multifunctional reactive ultraviolet absorber, which may comprise any ultraviolet absorber having multiple reactive functional groups that can bond to the polymer chain of the second polymer. In a preferred embodiment of the present invention, the first ultraviolet absorber is a benzotriazole type ultraviolet absorber, preferably an ultraviolet absorber having the following chemical formula (1).

[0049] [Chemical Formula (1)]

[0050]

[0051] In chemical formula (1), R1 is H or Cl. Compounds having the structure of chemical formula (1) can be synthesized by reacting a compound having a benzotriazol structure with a compound having three hydroxyl groups in the presence of an acid catalyst. Examples of compounds having a benzotriazol structure include, but are not limited to, 3-(2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-benzene propanoic acid or 3-(5-chloro-2H-benzotriazol-2-yl)-5-(1,1-dimethylethyl)-4-hydroxy-benzene propanoic acid. Examples of compounds having three hydroxyl groups include, but are not limited to, trimethylolpropane. Examples of acid catalysts include, but are not limited to, p-toluenesulfonic acid.

[0052] There are no particular limitations on the method for forming the light-shielding layer of the polymer structure of the present invention. Existing plastic molding methods or thin film coating methods can be used to form the light-shielding layer of the polymer structure of the present invention. Taking the preparation of a light-shielding layer in which the second polymer is polyurethane as an example, a first ultraviolet light absorber (e.g., a compound having the structure of chemical formula (1)) can be added to the raw materials for synthesizing polyurethane to participate in the polymerization reaction, so as to obtain polyurethane containing structural units derived from the first ultraviolet light absorber. The content of the first ultraviolet light absorber can be such that, based on the total weight of the second polymer, it is from 0.5 wt% to 45 wt%, for example, 0.5 wt%, 0.6 wt%, 0.7 wt%, 0.8 wt%, 0.9 wt%, 1 wt%, 1.5 wt%, 2 wt%, 2.5 wt%, 3 wt%, 3.5 wt%, 4 wt%, 4.5 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, 9 wt%. The percentages are 10 wt%, 11 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt%, 16 wt%, 17 wt%, 18 wt%, 19 wt%, 20 wt%, 21 wt%, 22 wt%, 23 wt%, 24 wt%, 25 wt%, 26 wt%, 27 wt%, 28 wt%, 29 wt%, 30 wt%, 31 wt%, 32 wt%, 33 wt%, 34 wt%, 35 wt%, 36 wt%, 37 wt%, 38 wt%, 39 wt%, 40 wt%, 41 wt%, 42 wt%, 43 wt%, 44 wt%, or 45 wt%, or within the range of any two of the above values. This polyurethane can be further formed into a light-shielding layer by co-extrusion or co-injection with a first polymer as a substrate, or by dissolving it in an organic solvent to form a solution and then coating it onto the surface of a substrate to form a light-shielding layer. The detailed preparation method is illustrated in the attached examples and will not be repeated here.

[0053] 1.3. Other layered structures

[0054] In addition to the substrate and the light-shielding layer covering at least a portion of the substrate surface, the polymer structure of the present invention may further include other layer structures. In some embodiments of the present invention, a carrier layer may be disposed on the other surface of the substrate not covered by the light-shielding layer. The carrier layer may be a polymer film, polymer sheet, or polymer plate formed of a third polymer. Examples of the third polymer have been illustrated above with respect to the first and second polymers and will not be repeated here.

[0055] In the case where the polymer structure of the present invention includes a carrier layer, the thickness of the carrier layer is not particularly limited, and generally can be from 100 micrometers to 200 millimeters, for example 100 micrometers, 150 micrometers, 200 micrometers, 250 micrometers, 300 micrometers, 350 micrometers, 400 micrometers, 450 micrometers, 500 micrometers, 550 micrometers, 600 micrometers, 650 micrometers, 700 micrometers, 750 micrometers, 800 micrometers, 850 micrometers, 900 micrometers, 950 micrometers, 1 millimeter, 5 millimeters, 10 millimeters, 15 millimeters, 20 millimeters, 25 millimeters, 30 millimeters, 35 millimeters, 40 millimeters. 45 mm, 50 mm, 55 mm, 60 mm, 65 mm, 70 mm, 75 mm, 80 mm, 85 mm, 90 mm, 95 mm, 100 mm, 105 mm, 110 mm, 115 mm, 120 mm, 125 mm, 130 mm, 135 mm, 140 mm, 145 mm, 150 mm, 155 mm, 160 mm, 165 mm, 170 mm, 175 mm, 180 mm, 185 mm, 190 mm, 195 mm, or 200 mm, or within the range of any two of the above values.

[0056] 2. Application

[0057] The polymer structure of this invention has a wide range of applications, including but not limited to the construction industry, aerospace industry, transportation industry, electronics industry, medical devices, daily necessities, food industry, and military industry. Due to its excellent weather resistance and anti-yellowing properties, the polymer structure of this invention is particularly suitable for use in places exposed to sunlight or ultraviolet light for extended periods. Furthermore, because the polymer structure of this invention has good visible light transmittance (i.e., excellent transparency), it can be used without affecting the appearance of the covered object, and is therefore also suitable for use as a transparent cover.

[0058] Therefore, the present invention also provides an application of polymer structures in the preparation of articles that can resist ultraviolet light. In some embodiments of the present invention, the articles include, but are not limited to, transparent covers, components of electronic products, peripheral materials of solar panels, components of vehicles, clothing materials, optical products, building components, wind power generation components, agricultural components, military industrial products, external viewing surfaces of displays, films, sheets, or explosion-proof panels.

[0059] Specifically, examples of components for transportation vehicles include, but are not limited to, lamps, vehicle shells, automotive lights, interior surface materials, windshields, and side window glass. Examples of transparent enclosures include, but are not limited to, lamp covers and backlights. Examples of components for electronic products include, but are not limited to, the shells of mobile devices. Examples of clothing materials include, but are not limited to, clothing, trousers, coats, and shoes. Examples of optical products include, but are not limited to, optical lenses, optical components, photochromic lenses, and contact lenses. Examples of architectural components include, but are not limited to, windows, doors, roofing membranes, roof tiles, roofing linings, eaves, wall materials, flooring materials, road construction components, pipe materials, signs, and sun visors. Examples of wind power generation components include, but are not limited to, windmill components. Examples of agricultural components include, but are not limited to, greenhouse covering films. Examples of military industrial products include, but are not limited to, transparent bodies for aircraft, radar radomes, and bulletproof panels. Examples of external viewing surfaces for displays include, but are not limited to, transparent screen films. Examples of films include, but are not limited to, vehicle wrapping films, conductive films, microwave absorbing films, thermal transfer films, packaging films, and low-resistance films. Examples of sheets include, but are not limited to, light filters. Examples of explosion-proof panels include, but are not limited to, explosion-proof glass.

[0060] 3. Example

[0061] 3.1. Measurement Method Description

[0062] The present invention will now be further illustrated by the following specific embodiments, wherein the measuring instruments and methods used are as follows:

[0063] [Weather Resistance Test - Xenon Lamp]

[0064] The samples were placed in a xenon lamp aging test chamber (model: Q-SUN Xenon Test Chamber, purchased from Q-Lab) and weathered under the following conditions: black panel temperature 60℃, irradiance 0.5W / m². 2 (watts per square meter) @ 340 nanometers.

[0065] [Weather Resistance Test - Outdoor Sunlight]

[0066] The samples were placed outdoors in a sunny location for weather resistance testing.

[0067] [Hue Detection]

[0068] According to ASTM 1926-70, the yellow index (YI) of the sample was tested using a spectrophotometer (model: ColorQuest XE, purchased from Hunter Lab).

[0069] [Color Difference Detection]

[0070] Using a UV-Vis spectrophotometer (model: Varian) 50, purchased from Agilent Technologies, was used to test the ΔE of the sample.

[0071] 3.2. Thermoplastic aromatic polyurethane for light-shielding layers

[0072] 3.2.1. Preparation of thermoplastic aromatic polyurethane

[0073] [Preparation Example 1-1]

[0074] 100 g of polytetrahydrofuran (model: PTMEG1000, purchased from Mitsubishi Chemical, OH value 112.2), 11 g of 1,4-butanediol (purchased from Tokyo Chemical), and 0.15 wt% (based on the total weight of reactants) of hindered phenolic antioxidant (model: Deox 105, compound name: triethylene glycol bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate) were mixed.

[0075] (triethylene glycol bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate), CAS No.: 36443-68-2, purchased from Qitai Technology), 0.05% by weight (based on the total weight of reactants) of benzo-furanone antioxidant (model: Revonox 501, compound name: 4-(1,1-dimethylethyl)-2[5-(1,1-dimethylethyl)-2,3-dihydro-2-oxo-3-benzofuranyl]phenyl-3,5-bis(1,1-dimethylethyl)-4-hydroxybenzoate (benzoic acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 4-(1,1-dimethylethyl)-2-[5-(1,1-dimethylethyl)

[0076] [-2,3-dihydro-2-oxo-3-benzofuranyl]phenyl ester), CAS No.: 1261240-30-5, purchased from Chitai Technology), 0.1 wt% (based on the total weight of reactants) of organophosphite antioxidant (model: Deox 604, compound name: 3,9-bis(2,4-bis(1,1-dimethylethyl)phenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro(5.5)undecane), CAS No.: 26741-53-7, purchased from Chitai Technology), 0.5 wt% (based on the total weight of reactants) of UV stabilizer (model: Chiguard) 1152, compound name: 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)amino]-6-(2-hydroxyethylamino)-1,3,5-triazine (CAS No.: 191743-75-6, purchased from Chitai Technology), 0.85 g of reactive UV absorber (model: Chiguard R-455, purchased from Chitai Technology) and 200 ppm of dibutyltin dilaurate were added to a reaction vessel and heated to 110°C. Separately, 56 g of diphenylmethane diisocyanate was added.

[0077] (methylene diphenyl diisocyanate, MDI) (purchased from BASF) was preheated to 110°C, added to a reaction vessel, and stirred for 1 minute to obtain thermoplastic aromatic polyurethane. The content of the reactive UV absorber was approximately 0.5% by weight of the total weight of the thermoplastic aromatic polyurethane.

[0078] [Preparation Examples 1-2]

[0079] The thermoplastic aromatic polyurethane of Preparation Example 1-2 was prepared in the same manner as in Preparation Example 1-1, but the amount of MDI was adjusted to 56.5 g, and the amount of the reactive ultraviolet absorber Chiguard R-455 was adjusted to 1.7 g. The content of the reactive ultraviolet absorber was approximately 1.0% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[0080] [Preparation Examples 1-3]

[0081] The thermoplastic aromatic polyurethanes of Preparation Examples 1-3 were prepared in the same manner as those of Preparation Example 1-1, except that the amount of MDI was adjusted to 57 g and the amount of the reactive UV absorber Chiguard R-455 was adjusted to 2.55 g. The content of the reactive UV absorber was approximately 1.5% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[0082] [Preparation Examples 1-4]

[0083] The thermoplastic aromatic polyurethanes of Preparation Examples 1-4 were prepared in the same manner as those of Preparation Example 1-1, except that the amount of MDI was adjusted to 57.4 g and the amount of the reactive UV absorber Chiguard R-455 was adjusted to 3.45 g. The content of the reactive UV absorber was approximately 2.0% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[0084] [Reference Example 1]

[0085] The thermoplastic aromatic polyurethane of Reference Example 1 was prepared in the same manner as in Preparation Example 1-1, but instead of adding the reactive UV absorber Chiguard R-455, 0.85 g of an oxamide-based additive UV absorber (model: 312 (purchased from BASF). The content of the additive UV absorber is approximately 0.5% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[0086] [Reference Example 2]

[0087] The thermoplastic aromatic polyurethane of Reference Example 2 was prepared in the same manner as Reference Example 1, but the amount of the added ultraviolet absorber 312 was adjusted to 1.7 grams. The content of the added ultraviolet absorber was approximately 1.0% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[0088] [Reference Example 3]

[0089] The thermoplastic aromatic polyurethane of Reference Example 3 was prepared in the same manner as in Reference Example 1, but the amount of the additive ultraviolet absorber 312 was adjusted to 2.55 grams. The content of the additive ultraviolet absorber was approximately 1.5% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[0090] [Preparation Examples 1-5]

[0091] The thermoplastic aromatic polyurethanes of Preparation Examples 1-5 were prepared in the same manner as those of Preparation Example 1-1, except that the amount of MDI was adjusted to 60.3 g and the amount of the reactive UV absorber Chiguard R-455 was adjusted to 9 g. The content of the reactive UV absorber was approximately 5% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[0092] [Preparation Examples 1-6]

[0093] The thermoplastic aromatic polyurethanes of Preparation Examples 1-6 were prepared in the same manner as those of Preparation Example 1-1, except that the amount of MDI was adjusted to 66.3 g and the amount of the reactive UV absorber Chiguard R-455 was adjusted to 19.7 g. The content of the reactive UV absorber was approximately 10% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[0094] [Preparation Examples 1-7]

[0095] The thermoplastic aromatic polyurethanes of Preparation Examples 1-7 were prepared in the same manner as those of Preparation Example 1-1, except that the amount of MDI was adjusted to 82 g and the amount of the reactive UV absorber Chiguard R-455 was adjusted to 48.5 g. The content of the reactive UV absorber was approximately 20% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[0096] 3.2.2. Preparation of thermoplastic aromatic polyurethane test pieces

[0097] Test pieces were prepared using the thermoplastic aromatic polyurethanes prepared in Examples 1-1 to 1-4 and Reference Examples 1 to 3. 55 grams of thermoplastic aromatic polyurethane were placed at 100°C for 2 hours to thoroughly dry and remove surface moisture. Then, the polyurethane was placed in a mold (20 cm × 15 cm × 0.15 cm) and hot-pressed at 190°C for 1.5 minutes at a pressure of 20 kg / cm² using a thermoforming machine (purchased from Longchang Company). The hot-pressed polyurethane was then placed in a cold press and cooled at 50 kg / cm² for 5 to 10 minutes to obtain a thermoplastic aromatic polyurethane test piece with a thickness of 0.15 cm.

[0098] 3.2.3. Outdoor Sunlight Weathering Resistance Test of Thermoplastic Aromatic Polyurethane Specimens

[0099] Outdoor solar weathering resistance tests were conducted on thermoplastic polyurethane specimens using the aforementioned method, and the results are recorded in Table 1.

[0100] Table 1: Outdoor Sunlight Weather Resistance Test of Thermoplastic Polyurethane Specimens

[0101]

[0102] As shown in Table 1, the outdoor light exposure resistance to yellowing of thermoplastic aromatic polyurethanes increases with the increase of the amount of UV absorber added. As shown in Preparation Examples 1-1 to 1-4, when the structure of the thermoplastic aromatic polyurethane contains structural units derived from the compound of chemical formula (1), the ΔYI value is lower and decreases with increasing addition amount. In particular, as shown in Preparation Examples 1-2 to 1-4, the reactive UV absorber participates in the chain extension reaction during the synthesis of thermoplastic polyurethane and becomes part of the polymer backbone. Therefore, it does not have a release problem even at high addition amounts, and can give thermoplastic polyurethanes good weather resistance, allowing for long-term outdoor use and exhibiting better weather resistance and anti-yellowing properties. In contrast, as shown in Reference Examples 2 and 3, the additive UV absorber will have a release problem at high addition amounts, making it unsuitable for long-term outdoor use.

[0103] 3.3. Preparation of substrates for polymer structures

[0104] [Preparation Example 2-1]

[0105] 100 g of polytetrahydrofuran (PTMEG1000), 11 g of 1,4-butanediol, 0.15 wt% (based on the total weight of reactants) of hindered phenolic antioxidant Deox 105, 0.05 wt% (based on the total weight of reactants) of benzofuranone antioxidant Revonox 501, 0.1 wt% (based on the total weight of reactants) of organophosphite antioxidant Deox 604, 0.5 wt% (based on the total weight of reactants) of UV stabilizer Chiguard 1152, and 200 ppm of dibutyltin dilaurate were added to a reaction vessel and heated to 110°C. Separately, 55.5 g of MDI, preheated to 110°C, was added to the reaction vessel and stirred for 1 minute to prepare a thermoplastic aromatic polyurethane block. The adhesive block was placed in an oven and baked at 70°C for 24 hours, and then a substrate with a thickness of 0.15 cm was prepared in the same manner as described in Section 3.2.2.

[0106] [Preparation Example 2-2]

[0107] 100 g of polyethylene glycol butylene adipate (model: PEBA1000, purchased from Quanda Chemical, OH value 112.2), 11 g of 1,4-butanediol, 0.15 wt% (based on total reactant weight) of hindered phenolic antioxidant Deox105, 0.05 wt% (based on total reactant weight) of benzofuranone antioxidant Revonox 501, 0.1 wt% (based on total reactant weight) of organophosphite antioxidant Deox 604, and 200 ppm of dibutyltin dilaurate were added to a reaction vessel and heated to 110°C. Separately, 55.5 g of MDI, preheated to 110°C, was added to the reaction vessel and stirred for 1 minute to prepare a thermoplastic aromatic polyurethane block. The rubber block was placed in an oven and baked at 70°C for 24 hours, and then a substrate with a thickness of 0.15 cm was made in the same manner as described in Section 3.2.2.

[0108] [Preparation Examples 2-3]

[0109] The substrates of Preparation Example 2-3 were prepared in the same manner as those of Preparation Example 2-2, but with the addition of 0.5% by weight (based on the total weight of the reactants) of the UV stabilizer Chiguard 228 (purchased from Chitai Technology).

[0110] [Preparation Examples 2-4]

[0111] The substrates of Preparation Example 2-4 were prepared in the same manner as those of Preparation Example 2-2, but with the addition of 0.25% by weight (based on the total weight of the reactants) of the UV stabilizer Chiguard 622 (purchased from Chitai Technology) and 0.25% by weight (based on the total weight of the reactants) of the UV stabilizer Chiguard 100 (purchased from Chitai Technology).

[0112] 3.4. Polymer Structure

[0113] [Example 1]

[0114] High-efficiency light-shielding layers were prepared using the thermoplastic aromatic polyurethanes of Preparation Examples 1-5 to 1-7. These high-efficiency light-shielding layers contained 5 wt%, 10 wt%, and 20 wt% reactive ultraviolet light absorbers, respectively, and had a thickness of only 20 micrometers. The thermoplastic aromatic polyurethanes of Preparation Examples 1-5 to 1-7 were dissolved in dimethylacetamide (DMAC) at elevated temperature to form a 20% solids solution, which was then diluted with methyl ethyl ketone (MEK) / toluene to a coating solution with a solids content of approximately 10%. The coating solution was applied to transparent glass and dried in an oven at 120°C to form a light-shielding layer with a thickness of 20 micrometers. The light-shielding layer was removed from the transparent glass, and samples of the light-shielding layers prepared in Preparation Examples 1-5 and 1-6 were taken for weather resistance testing. The results are as follows: (1) The YI value of the 20-micron light-shielding layer of Preparation Example 1-5 after 714 hours of xenon lamp irradiation was 2.1, and the YI value of the 20-micron light-shielding layer of Preparation Example 1-6 after 639 hours of xenon lamp irradiation was 1.4; and (2) The YI value of the 20-micron light-shielding layer of Preparation Example 1-5 after 78 days of outdoor sunlight exposure was 2.5, and the YI value of the 20-micron light-shielding layer of Preparation Example 1-6 after 96 days of outdoor sunlight exposure was 1.3. From the above results, it can be observed that the high-efficiency light-shielding layer containing a high concentration of reactive ultraviolet light absorber, in addition to its extremely low chromaticity, also has excellent long-term resistance to photoyellowing.

[0115] The removed light-shielding layer was placed on the substrate of Preparation Example 2-1 to form a polymer structure. Weather resistance tests were performed on the polymer structure using the aforementioned method, and the results are recorded in Tables 2-1 to 2-2.

[0116] Table 2-1: Outdoor Sunlight Weather Resistance Test of Polymer Structures

[0117]

[0118] Table 2-2: Weathering resistance test of polymer structures for xenon lamps

[0119]

[0120] As can be seen from Tables 2-1 to 2-2, the polymer structure of the present invention exhibits excellent weather resistance and can be used outdoors for extended periods. Furthermore, as shown in Table 2-1, compared to a thermoplastic aromatic polyurethane substrate without a light-shielding layer (Preparation Example 2-1), the polymer structure of the present invention (i.e., the polymer structure comprising the substrate of Preparation Example 2-1 and the light-shielding layers of Preparation Examples 1-5 to 1-7) exhibits significantly improved weather resistance and resistance to yellowing.

[0121] [Example 2]

[0122] Using the same testing method as in Example 1, the thermoplastic aromatic polyurethanes of Preparation Examples 1-5 and 1-6 were dissolved using DMAC to form a 20% solids content solution, which was then diluted with MEK / toluene to a coating solution with a solids content of approximately 10%. The coating solution was applied to transparent glass and dried in an oven at 120°C to form a light-shielding layer with a thickness of 20 micrometers. The light-shielding layer was removed from the transparent glass and placed on the substrates of Preparation Examples 2-2 to 2-4 to form polymer structures. Weather resistance tests were performed on the polymer structures using the aforementioned method, and the results are recorded in Tables 2-3 to 2-6.

[0123] Table 2-3: Weathering resistance test of polymer structures for xenon lamps

[0124]

[0125]

[0126] Table 2-4: Weathering resistance test of polymer structures for xenon lamps

[0127]

[0128] Table 2-5: Outdoor Sunlight Weather Resistance Test of Polymer Structures

[0129]

[0130] Table 2-6: Outdoor Sunlight Weather Resistance Test of Polymer Structures

[0131]

[0132] As can be seen from Tables 2-3 to 2-6, in the polymer structure of the present invention, the yellowing value of the 20-micron light-shielding layer itself is already extremely low. If an ultraviolet light stabilizer is added to the substrate, the light yellowing resistance of the entire polymer structure can be further improved, so that the entire polymer structure can have excellent long-term outdoor weather resistance and yellowing resistance.

[0133] 3.5. Co-extruded polymer structures

[0134] [Example 3]

[0135] The thermoplastic aromatic polyurethane containing a reactive UV absorber, the thermoplastic aromatic polyurethane containing HALS (Chiguard 1152, purchased from Chitai Technology, 0.5 wt%) (model: 90AE, purchased from Huntsman), and polypropylene (model: PD943, purchased from LCYCHEMICAL CORP.) of Preparation Examples 1-5 and 1-6 were co-extruded to form a three-layer co-extruded polymer structure. The light-shielding layer formed by the thermoplastic aromatic polyurethane of Preparation Examples 1-5 and 1-6 had a thickness of approximately 30 micrometers, the substrate formed by thermoplastic aromatic polyurethane 90AE had a thickness of approximately 120 micrometers, and the carrier formed by polypropylene PD 943 had a thickness of approximately 125 micrometers. Weather resistance tests were performed on the co-extruded polymer structures using the aforementioned method, and the results are recorded in Tables 3-1 and 3-2.

[0136] Table 3-1: Xenon Lamp Weathering Test of Co-extruded Polymer Structures

[0137]

[0138]

[0139] Table 3-2: Outdoor Sunlight Weather Resistance Test of Co-extruded Polymer Structures

[0140]

[0141] As can be seen from Tables 3-1 and 3-2, the polymer structures of the present invention prepared in different ways also exhibit good weather resistance and can be used outdoors for extended periods. Through the design of this invention, thermoplastic aromatic polyurethanes, which are highly susceptible to yellowing due to sunlight, can achieve excellent long-term weather resistance and anti-yellowing properties, overcoming the limitation of their use in outdoor products due to weathering and yellowing issues, expanding their industrial application range, and creating potential commercial value.

[0142] The above embodiments are merely illustrative of the principles and effects of the present invention and to illustrate its technical features, and are not intended to limit the scope of protection of the present invention. Any changes or arrangements that can be easily made by those skilled in the art without departing from the technical principles of the present invention are within the scope claimed by the present invention.

Claims

1. A polymer structure comprising a substrate and a light-shielding layer covering at least a part of the surface of the substrate, characterized in that, The substrate comprises a first polymer and the light-shielding layer comprises a second polymer, wherein the first polymer is a thermoplastic aromatic polyurethane and the second polymer is a thermoplastic aromatic polyurethane, wherein the second polymer comprises structural units derived from a first ultraviolet light absorber, triethylene glycol bis(3-tert-butyl-4-hydroxy-5-methylphenyl)propionate, 4-(1,1-dimethylethyl)-2[5-(1,1-dimethylethyl)-2,3-dihydro-2-oxo-3-benzofuranyl]phenyl-3,5-bis(1,1-dimethylethyl)-4-hydroxybenzoate, 3,9-bis(2,4-bis(1,1-dimethylethyl)phenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro(5.5)undecane, and 2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)aminyl]-6-(2-hydroxyethylaminyl)-1,3,5-triazine, and the light-shielding layer has a thickness of 5 micrometers to 200 micrometers, the first ultraviolet light absorber has the following chemical formula (1): [Chemical formula (1)] ， In the chemical formula (1), R1 is H or Cl, wherein the content of the first ultraviolet light absorber is 10% to 20% by weight based on the total weight of the second polymer; and The polymer structure has a visible light transmittance of 65% or more.

2. The polymeric structure of claim 1, wherein The light-shielding layer covers at least a light-receiving surface of the substrate.

3. The polymeric structure according to claim 1 or 2, wherein The substrate and the light-shielding layer each independently comprise an additive selected from the group consisting of an antifoaming agent, a leveling wetting agent, a thickening agent, a dispersing agent, a matting powder, an antibacterial agent, a metal oxide light-shielding agent, a light stabilizer, a heat stabilizer, a non-reactive ultraviolet light absorber, a monofunctional reactive ultraviolet light absorber, an antioxidant, a filler, a flame retardant, a plasticizer, a dye, a pigment, a brightening agent, an antistatic agent, a fluorescent whitening agent, an anti-aging agent, a metal stabilizer, an acid absorbent, an anti-hydrolysis agent, a wax, and combinations thereof.

4. Use of the polymer structure according to any one of claims 1 to 3 for the production of an ultraviolet light-resistant article.

5. Use according to claim 4, characterized in that, The article is selected from the group consisting of a transparent cover, a member of an electronic product, a solar panel peripheral material, a member of a vehicle, a clothing material, an optical article, a building member, a wind power generation member, an agricultural member, a military industry article, a display external viewing surface, a film, a sheet, and a blast-resistant panel.

6. The use according to claim 4, characterized in that, The article is selected from the group consisting of a vehicle envelope, a lamp cover, a housing of a mobile device, a vehicle housing, a car lamp, a surface material for a vehicle interior, a windshield, a side window, a window, a door, a filter, a garment, a shoe, an optical component, a roof membrane, a roof tile, a roof underlayment, a roof overhang, a wall material, a floor material, a road construction member, a pipe material, a sign, a sun visor, a greenhouse covering film, a back light, a windmill component, an aircraft transparency, a radar antenna cover, a blast-resistant glass, a bullet-proof panel, a transparent screen film, a conductive film, a microwave absorbing film, a thermal transfer printing film, a packaging film, and a low resistance film.

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