TWI861598B - Polymer structure and uses thereof - Google Patents

Abstract

A polymer structure and uses thereof are provided. The polymer structure comprises 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 which comprises a structural unit derived from a first ultraviolet absorbing agent, the light shielding layer has a thickness of 1 μm to 200 μm, and the first ultraviolet absorbing agent is a polyfunctional reactive ultraviolet absorbing agent.

Description

Polymer structures and their uses

The present invention relates to a polymer structure, more particularly, to a thermoplastic polyurethane structure having a thin ultraviolet light shielding layer.

Polyurethane is an important polymer formed by the polymerization of polyols and isocyanates. By adjusting the ratio of raw materials, materials with the required mechanical properties can be manufactured, including wear resistance, temperature resistance, flexibility, elongation, etc. Polyurethane has been widely used in various materials, such as coatings, elastomers, foaming materials, adhesives, sealants, etc. Generally speaking, polyurethane can be divided into aliphatic polyurethane and aromatic polyurethane according to the presence or absence of aromatic rings in the structure. Aromatic polyurethane is superior to aliphatic polyurethane in physical and chemical properties and processability, but the weathering and yellowing problem of aromatic polyurethane has always been a difficult problem to solve in the industry.

US 7,910,642 B2 proposes to solve the above problems by using additive ultraviolet absorbing agent (UVA) and hindered amine light stabilizer (HALS). However, due to the compatibility between additive ultraviolet absorbing agent and aromatic polyurethane, the amount of additive ultraviolet absorbing agent added has an upper limit, so the anti-yellowing effect cannot be significantly improved. Therefore, the yellowing problem cannot be completely solved, so the application of aromatic polyurethane, especially in outdoor items, has been restricted for a long time.

In order to protect polymer materials from the effects of ultraviolet radiation on their properties, conventional techniques are to directly add or react ultraviolet absorbers into the polymer materials to be protected. The ultraviolet absorbing components of the polymer materials prepared in this way are evenly distributed throughout the polymer materials. Therefore, even if only the ultraviolet absorbing components distributed near the surface of the polymer materials can actually play an anti-ultraviolet function, a large amount of ultraviolet absorbers must still be added to the entire polymer materials to ensure that the content of ultraviolet absorbing components near the surface of the polymer materials is sufficient to resist ultraviolet rays. However, the result of adding a large amount of ultraviolet absorbers is not only an increase in cost, but also an adverse effect on the physical and chemical properties of the polymer materials. In particular, for transparent or white polymer materials with high application value (such as thermoplastic polyurethane), adding a large amount of UV absorbers will significantly affect the color of the polymer material visually, resulting in a reduction in commercial value. This also explains why aromatic polyurethanes are superior to aliphatic polyurethanes in physical and chemical properties and processability, but are always excluded from use in outdoor items due to their weathering and yellowing problems.

In view of the above technical problems, the present invention provides an innovative idea to provide a composite polymer material by forming a thin UV shielding layer on the surface of the polymer material, which can simultaneously achieve the advantages of effective UV resistance, low cost, and minimized impact on the physical and chemical properties of the polymer material, thereby solving the long-standing bottleneck of aromatic polyurethane in the application of outdoor items in the industry.

Specifically, one object of the present invention is to provide a polymer structure, which comprises 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 a structural unit derived from a first ultraviolet light absorber, and the light shielding layer has a thickness of 1 micron to 200 microns, and the first ultraviolet light absorber is a multifunctional reactive ultraviolet light absorber.

In some embodiments of the present invention, the light shielding layer has a thickness of 2 microns to 100 microns.

於化學式(1)中，R1為H或Cl。 In some embodiments of the present invention, the first ultraviolet light absorber has the following chemical formula (1):

In the chemical formula (1), R1 is H or Cl.

In some embodiments of the present invention, the content of the first ultraviolet light absorber is 0.5 wt% to 45 wt% based on the total weight of the second polymer.

In some embodiments of the present invention, the first polymer and the second polymer are independently selected from the following groups: polyurethane, polyester, polycarbonate, epoxy resin, amine resin, polyamide, polyimide, polypropylene, polyethylene, liquid crystal polymer, acrylonitrile-butadiene-styrene copolymer, polyoxymethylene, polystyrene, and composites thereof.

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

In some embodiments of the present invention, the polyurethane is a thermoplastic polyurethane.

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

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

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

In some embodiments of the present invention, the substrate and the light shielding layer each independently contain additives selected from the following groups: defoaming agent, leveling wetting agent, thickener, dispersant, micro powder wax, matting powder, antibacterial agent, metal oxide light shielding agent, light stabilizer, heat stabilizer, non-reactive ultraviolet light absorber, monofunctional reactive ultraviolet light absorber, multifunctional reactive ultraviolet light absorber different from the first ultraviolet light absorber, antioxidant, filler, flame retardant, plasticizer, dye, pigment, brightener, antistatic agent, fluorescent whitening agent, anti-aging agent, metal stabilizer, acid absorbent, anti-hydrolysis agent, wax, and combinations thereof.

Another object of the present invention is to provide the use of the above-mentioned polymer structure in the preparation of products that can resist ultraviolet light.

In some embodiments of the present invention, the product is selected from the following groups: transparent outer 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, display external viewing surfaces, films, sheets, and explosion-proof panels.

In some embodiments of the present invention, the product is selected from the following group: vehicle envelope, lampshade, housing of mobile device, vehicle housing, car lamp, surface material for vehicle interior, windshield, side window glass, window, door, filter, clothing, pants, coat, shoes, optical lens, optical element, photochromic lens, contact lens, roof film , roof tiles, roof pads, eaves, wall materials, floor materials, road construction components, pipeline materials, signs, sunshades, greenhouse covering films, backlights, windmill parts, aircraft transparent bodies, radar antenna covers, explosion-proof glass, bulletproof panels, transparent screen films, conductive films, microwave absorbing films, thermal transfer films, packaging films, and low-resistance films.

In order to make the above-mentioned objectives, technical features and advantages of the present invention more clearly understood, the following is a detailed description of some specific implementation forms.

10:Polymer structure

11: Light shielding layer

12: Base material

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

The following will specifically describe some specific implementations of the present invention; however, the present invention can be implemented in a variety of different forms, and the scope of protection of the present invention should not be limited to the specific implementations described.

Unless otherwise specified, the terms "a", "the" and similar expressions used in this specification and the scope of the patent application shall be understood to include both singular and plural forms.

Unless otherwise specified, the terms "first", "second" and similar terms used in this specification and the scope of patent application are only used to distinguish the elements or components described, and have no special meanings and are not used to represent the order of precedence.

Unless otherwise specified, in this specification and the scope of the patent application, the term "non-reactive UV absorber" refers to a compound that absorbs UV light without a reactive functional group, the term "monofunctional reactive UV absorber" refers to a compound that absorbs UV light with one reactive functional group, and the term "multifunctional reactive UV absorber" refers to a compound that absorbs UV light with two or more reactive functional groups. Examples of the reactive functional groups include, but are not limited to, hydroxyl, carboxyl, carbonyl, amino, cyano, sulfonyl, phenyl, and nitro.

Unless otherwise specified, in this specification and the scope of the patent application, the term "light-receiving surface" refers to the surface that is irradiated with light.

The effect of the present invention compared with the prior art is to provide a polymer structure with a thin ultraviolet light shielding layer, especially a polymer structure comprising thermoplastic aromatic polyurethane as a substrate, wherein the ultraviolet light shielding layer is used to prevent the polymer substrate, such as thermoplastic aromatic polyurethane, from yellowing, and the thickness of the ultraviolet light shielding layer is controlled within a certain range to reduce the 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 the present invention and its application.

1. Polymer structure

FIG1 is a schematic diagram of the structure of a polymer structure of one embodiment of the present invention. As shown in FIG1 , the polymer structure 10 of the present invention comprises 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 the light-receiving surface and the non-light-receiving surface of the substrate 12.

1.1. Substrate

In the polymer structure of the present invention, the substrate comprises a first polymer, or is mainly composed of a first polymer, or is composed of a first polymer. In some embodiments of the present invention, the substrate is formed by the first polymer and an optional additive.

The type of the first polymer is not particularly limited, and examples thereof include but are not limited to polyurethane, polyester, polycarbonate, epoxy resin, amine 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 the thermoplastic polyurethane may be thermoplastic aromatic polyurethane or thermoplastic aliphatic polyurethane. An example of polyimide is colorless polyimide (CPI). Examples of polyesters 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 present invention, the first polymer is polyurethane, specifically thermoplastic polyurethane, and more specifically thermoplastic aromatic polyurethane.

The additives as needed can be used to improve the processability of the substrate or give it specific functions. Examples of additives include but are not limited to defoamers, leveling wetting agents, thickeners, dispersants, micronized waxes, matting powders, antimicrobial agents, metal oxide light shielding agents, light stabilizers, heat stabilizers, non-reactive UV absorbers, monofunctional reactive UV absorbers, multifunctional reactive UV absorbers different from the first UV absorber, antioxidants, fillers, flame retardants, plasticizers, dyes, pigments, brighteners, antistatic agents, fluorescent whitening agents, anti-aging agents, metal stabilizers, acid absorbers, anti-hydrolysis agents, and waxes. The aforementioned additives can be used alone or in combination. An example of a light stabilizer is a hindered amine light stabilizer (HALS), which is a compound with an amine group that can capture free radicals to inhibit photodegradation, usually a derivative of tetramethylpiperidine.

There is no particular limitation on the content of the additive, 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 0.01 to 5 parts by weight, such as 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.1 .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 formed by any two of the above values.

In the polymer structure of the present invention, the thickness of the substrate is not particularly limited. For example, it can be 1 μm to 150 mm, such as 1 μm, 5 μm, 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm , 900 microns, 950 microns, 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm, 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, or 150 mm, or within the range formed by any two of the above values, but the present invention is not limited thereto.

Due to the thin light shielding layer, the polymer structure of the present invention does not need to add a large amount of ultraviolet light absorbing components to the substrate, so that the original physical and chemical properties of the substrate can be better preserved, especially the original color or transparency of the substrate can be better preserved. Therefore, in some embodiments of the present invention, the polymer structure as a whole can have a visible light transmittance of 65% or more, such as 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 the present invention, the polymer structure can have a visible light transmittance of 95% or more.

1.2. Light shielding layer

In the polymer structure of the present invention, the light shielding layer includes a second polymer, or is mainly composed of a second polymer, or is composed of a second polymer, and the second polymer includes a structural unit derived from a first ultraviolet light absorber. In some embodiments of the present invention, the light shielding layer is formed by the second polymer and an optional additive.

In the polymer structure of the present invention, the thickness of the light shielding layer can be 1 μm to 200 μm, for example, 1 μm, 2 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 11 μm, 12 μm, 13 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, 20 μm, 21 μm, 22 μm, 23 μm, 24 μm, 25 μm, 26 μm, 27 μm, 28 μm, 29 μm, 30 μm, 31 μm, 32 μm, 33 μm, 34 μm, 35 μm, 36 μm, 37 μm, 38 μm, 39 μm, 40 μm, 41 μm, 42 μm, 43 μm, 44 μm, 45 μm, 46 μm, 47 μm, 48 μm, 49 μm, 50 μm, 51 μm, 52 μm, 53 μm, 54 μm, 55 μm, 56 μm, 57 μm, 58 μm, 59 μm, 60 μm, 61 μm, 62 μm, 63 μm, 64 μm, 65 μm, 66 μm, 67 μm, 68 μm, 69 μm, 70 μm, 71 μm, 72 μm, 73 μm, 74 μm 3 microns, 54 microns, 55 microns, 56 microns, 57 microns, 58 microns, 59 microns, 60 microns, 61 microns, 62 microns, 63 microns, 64 microns, 65 microns, 66 microns, 67 microns, 68 microns, 69 microns, 70 microns, 71 microns, 72 microns, 73 microns, 74 microns, 75 microns, 76 microns, 77 microns, 78 microns, 79 microns, 80 microns, 81 microns, 82 microns, 83 microns, 84 microns, 85 microns, 86 microns, 87 microns, 88 microns, 89 microns, 90 microns, 91 microns, 92 microns, 93 microns, 94 microns, 95 microns, 96 microns, 97 microns, 98 microns, 99 microns, 100 microns, 101 microns, 102 microns, 103 microns, 104 microns, 105 microns, 106 microns, 107 microns, 108 microns , 109 microns, 110 microns, 111 microns, 112 microns, 113 microns, 114 microns, 115 microns, 116 microns, 117 microns, 118 microns, 119 microns, 120 microns, 121 microns, 122 microns, 123 microns, 124 microns, 125 microns, 126 microns, 127 microns, 128 microns, 129 microns, 130 microns, 131 microns, 132 microns, 133 microns, 134 microns, 135 microns, 136 microns, 137 microns, 138 microns, 139 microns, 140 microns, 141 microns, 142 microns, 143 microns, 144 microns, 145 microns, 146 microns, 147 microns, 148 microns, 149 microns, 150 microns, 151 microns, 152 microns, 153 microns, 154 microns, 155 microns, 156 190 microns, 191 microns, 192 microns, 193 microns, 194 microns, 195 microns, 196 microns, 197 microns, 198 microns, 199 microns, or 200 microns, or in a range consisting of any two of the foregoing values. In a preferred embodiment of the present invention, the light shielding layer has a thickness of 2 microns to 100 microns. When the thickness of the light shielding layer is within the above range, the phenomenon of reduced transparency caused by high concentration of ultraviolet light absorber can be ignored, thereby maintaining the visible light transmittance of the overall polymer structure.

The type of the second polymer is not particularly limited, and examples thereof include but are not limited to polyurethane, polyester, polycarbonate, epoxy resin, amine 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 can 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 present invention, the second polymer is polyurethane, specifically thermoplastic polyurethane, and more specifically thermoplastic aromatic polyurethane.

The first ultraviolet light absorber is a multifunctional reactive ultraviolet light absorber, which may include any ultraviolet light absorber having multiple reactive functional groups and capable of bonding to the polymer chain of the second polymer. In a preferred embodiment of the present invention, the first ultraviolet light absorber is a benzotriazole type ultraviolet light absorber, preferably an ultraviolet light absorber having the following chemical formula (1).

[Chemical formula (1)]

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

There is no particular limitation on the method for forming the light shielding layer of the polymer structure of the present invention. The light shielding layer of the polymer structure of the present invention can be formed by a known plastic molding method or a film coating method. Taking the preparation of a light shielding layer in which the second polymer is polyurethane as an example, a first ultraviolet light absorber (for example, a compound having a structure of chemical formula (1)) can be added to the raw material for synthesizing polyurethane to participate in the polymerization reaction to obtain a polyurethane containing structural units derived from the first ultraviolet light absorber. The content of the first ultraviolet light absorber can be such that it is 0.5 wt % to 45 wt % based on the total weight of the second polymer, 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%, 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 a range consisting of any two of the above values. The polyurethane can be co-extruded or co-injected with the first polymer as the substrate to form a light shielding layer, or can be dissolved in an organic solvent to form a solution, and then coated on the surface of the substrate to form a light shielding layer. The detailed preparation method is shown in the attached examples and will not be further described here.

1.3. Other layers

In addition to the substrate and the light shielding layer covering at least part of the surface of the substrate, 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 provided on the other surface of the substrate not covered with the light shielding layer. The carrier layer may be a polymer film, a polymer sheet or a polymer plate formed by a third polymer. Examples of the third polymer are described above for the first polymer and the second polymer, and will not be further described here.

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 100 μm to 200 mm, for example, 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm, 400 μm, 450 μm, 500 μm, 550 μm, 600 μm, 650 μm, 700 μm, 750 μm, 800 μm, 850 μm, 900 μm, 950 μm, 1 mm, 5 mm, 10 mm, 15 mm, 20 mm, 25 mm, 30 mm, 35 mm, 40 mm m, 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 in the range formed by any two of the above values.

2. Application

The polymer structure of the present invention can be applied in a wide range of fields, including but not limited to the construction industry, aviation industry, transportation industry, electronics industry, medical equipment, daily necessities, food industry, and military industry. The polymer structure of the present invention has excellent weather resistance and anti-yellowing properties, and is particularly suitable for being placed in places exposed to sunlight or ultraviolet light for a long time. In addition, since the polymer structure of the present invention can have good visible light transmittance (i.e., good transparency), it can be used without affecting the appearance of the covered object, so it is also suitable for use as a transparent cover.

Therefore, the present invention also provides an application of a polymer structure in the preparation of products that can resist ultraviolet light. In some embodiments of the present invention, the products 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, display external viewing surfaces, films, sheets, or explosion-proof panels.

Specifically, examples of components of vehicles include, but are not limited to, lamps, vehicle shells, car lights, surface materials for vehicle interiors, windshields, and side windows. Examples of transparent covers include, but are not limited to, lampshades and backlights. Examples of components of electronic products include, but are not limited to, mobile device housings. Examples of clothing materials include, but are not limited to, clothes, pants, coats, and shoes. Examples of optical products include, but are not limited to, optical lenses, optical elements, photochromic lenses, and contact lens lenses. Examples of building components include, but are not limited to, windows, doors, roof membranes, roof tiles, roof pads, eaves, wall materials, floor materials, road construction components, piping materials, signs, and sunshades. Examples of wind power components include, but are not limited to windmill parts. Examples of agricultural components include, but are not limited to greenhouse covering films. Examples of military industrial products include, but are not limited to aircraft transparencies, radar antenna covers, and bulletproof panels. Examples of display external viewing surfaces include, but are not limited to transparent screen films. Examples of films include, but are not limited to vehicle wraps, conductive films, microwave absorbing films, thermal transfer films, packaging films, and low-resistance films. Examples of thin films include, but are not limited to filters. Examples of explosion-proof panels include, but are not limited to, explosion-proof glass.

3. Implementation Examples

3.1. Measurement method description

The present invention is further illustrated by the following specific implementation forms, wherein the measuring instruments and methods used are as follows:

[Weather resistance test-Xenon lamp]

The samples were placed in a xenon lamp weathering test chamber (model: Q-SUN Xenon Test Chamber, purchased from Q-Lab) and weathering tested under the following conditions: blackboard temperature of 60°C and irradiance of 0.5 W/m ² (watts/square meter) @ 340 nm.

[Weather resistance test-outdoor sunlight]

Place the sample outdoors in a sunny location for weathering test.

[Hue detection]

According to ASTM 1926-70, a spectrophotometer (model: ColorQuest XE, purchased from Hunter Lab) was used to test the yellowness index (YI) of the sample.

[Color difference detection]

The △E of the samples was tested using a UV-Vis spectrophotometer (model: Varian Cary® 50, purchased from Agilent).

3.2. Thermoplastic aromatic polyurethane for light shielding layer

3.2.1. Preparation of thermoplastic aromatic polyurethane

[Preparation Example 1-1]

100 g of polytetrahydrofuran (model: PTMEG1000, purchased from Mitsubishi Chemical, OH value 112.2), 11 g of 1,4-butanediol (purchased from Tokyo Chemical Industry), 0.15 wt% (based on the total weight of the reactants) of a hindered phenol antioxidant (model: Deox 105, purchased from Chi-Tai Technology), 0.05 wt% (based on the total weight of the reactants) of a benzo-furanone antioxidant (model: Revonox 501, purchased from Chi-Tai Technology), 0.1 wt% (based on the total weight of the reactants) of an organophosphite antioxidant (model: Deox 604, purchased from Chi-Tai Technology), 0.5 wt% (based on the total weight of the reactants) of UV stabilizer (model: Chiguard 1152, purchased from Chi-Tai Technology), 0.85 g of reactive UV absorber (model: Chiguard R-455, purchased from Chi-Tai Technology) and 200 ppm of dibutyltin dilaurate were added to the reaction iron pot and heated to 110°C. 56 g of methylene diphenyl diisocyanate (MDI) (purchased from BASF) was preheated to 110°C, added to the reaction pot and stirred for 1 minute to react to obtain thermoplastic aromatic polyurethane. The content of reactive UV absorber was about 0.5 wt% based on the total weight of the thermoplastic aromatic polyurethane.

[Preparation Example 1-2]

The thermoplastic aromatic polyurethane of Preparation Example 1-2 was prepared in the same manner as Preparation Example 1-1, except that the amount of MDI was adjusted to 56.5 grams, and the amount of reactive ultraviolet light absorber Chiguard R-455 was adjusted to 1.7 grams. The content of the reactive ultraviolet light absorber was about 1.0 weight % based on the total weight of the thermoplastic aromatic polyurethane.

[Preparation Example 1-3]

The thermoplastic aromatic polyurethane of Preparation Example 1-3 was prepared in the same manner as Preparation Example 1-1, except that the amount of MDI was adjusted to 57 grams, and the amount of reactive ultraviolet light absorber Chiguard R-455 was adjusted to 2.55 grams. The content of the reactive ultraviolet light absorber was about 1.5% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[Preparation Example 1-4]

The thermoplastic aromatic polyurethane of Preparation Example 1-4 was prepared in the same manner as Preparation Example 1-1, except that the amount of MDI was adjusted to 57.4 grams, and the amount of reactive ultraviolet light absorber Chiguard R-455 was adjusted to 3.45 grams. The content of the reactive ultraviolet light absorber was about 2.0 weight % based on the total weight of the thermoplastic aromatic polyurethane.

[Reference Example 1]

The thermoplastic aromatic polyurethane of Reference Example 1 was prepared in the same manner as Preparation Example 1-1, except that the reactive ultraviolet light absorber Chiguard R-455 was not added, and 0.85 g of an oxamide-based additive ultraviolet light absorber (model: Tinuvin® 312, purchased from BASF) was added instead. The content of the additive ultraviolet light absorber was about 0.5% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[Reference Example 2]

The thermoplastic aromatic polyurethane of Reference Example 2 was prepared in the same manner as Reference Example 1, except that the amount of the additive ultraviolet light absorber 312 was adjusted to 1.7 grams. The content of the additive ultraviolet light absorber was about 1.0 weight % based on the total weight of the thermoplastic aromatic polyurethane.

[Reference Example 3]

The thermoplastic aromatic polyurethane of Reference Example 3 was prepared in the same manner as Reference Example 1, except that the amount of the additive ultraviolet light absorber 312 was adjusted to 2.55 grams. The content of the additive ultraviolet light absorber was about 1.5% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[Preparation Example 1-5]

The thermoplastic aromatic polyurethane of Preparation Example 1-5 was prepared in the same manner as Preparation Example 1-1, except that the amount of MDI was adjusted to 60.3 grams, and the amount of reactive ultraviolet light absorber Chiguard R-455 was adjusted to 9 grams. The content of the reactive ultraviolet light absorber was about 5% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[Preparation Example 1-6]

The thermoplastic aromatic polyurethane of Preparation Example 1-6 was prepared in the same manner as Preparation Example 1-1, except that the amount of MDI was adjusted to 66.3 grams, and the amount of reactive ultraviolet light absorber Chiguard R-455 was adjusted to 19.7 grams. The content of the reactive ultraviolet light absorber was about 10% by weight based on the total weight of the thermoplastic aromatic polyurethane.

[Preparation Example 1-7]

The thermoplastic aromatic polyurethane of Preparation Example 1-7 was prepared in the same manner as Preparation Example 1-1, except that the amount of MDI was adjusted to 82 grams, and the amount of reactive ultraviolet light absorber Chiguard R-455 was adjusted to 48.5 grams. The content of the reactive ultraviolet light absorber was about 20% by weight based on the total weight of the thermoplastic aromatic polyurethane.

3.2.2. Preparation of Thermoplastic Aromatic Polyurethane Specimens

Thermoplastic aromatic polyurethanes of Preparation Examples 1-1 to 1-4 and Reference Examples 1 to 3 were used to prepare test pieces. 55 g of thermoplastic aromatic polyurethane was placed at 100°C for 2 hours to fully dry and remove surface moisture, then placed in a mold (size 20 cm × 15 cm × 0.15 cm), and heat-pressed for 1.5 minutes at 190°C using a hot press molding machine (purchased from Longchang Company) at a pressure of 20 kg/cm2. The hot-pressed thermoplastic polyurethane was then placed in a cold press and cooled at a pressure of 50 kg/cm2 for 5 to 10 minutes to obtain a thermoplastic aromatic polyurethane test piece with a thickness of 0.15 cm.

3.2.3. Outdoor sunlight weathering test of thermoplastic aromatic polyurethane specimens

The outdoor sunlight weathering test of thermoplastic polyurethane specimens was carried out using the above method, and the results are recorded in Table 1.

As can be seen from Table 1, the outdoor light yellowing resistance of the thermoplastic aromatic polyurethane increases with the increase in the amount of ultraviolet light absorber added. As shown in Preparation Examples 1-1 to 1-4, when the structure of the thermoplastic aromatic polyurethane contains a structural unit derived from the compound of chemical formula (1), the △YI value is low, and the value decreases with the increase in the amount added. In particular, as shown in Preparation Examples 1-2 to 1-4, the reactive ultraviolet light absorber participates in the chain expansion reaction during the synthesis of the thermoplastic polyurethane and becomes a part of the polymer main chain. Therefore, there is no problem of spitting out at a high addition amount, and the thermoplastic polyurethane can be given good weather resistance, which can be used outdoors for a long time and shows better weather resistance and anti-yellowing properties. In contrast, as shown in Reference Examples 2 and 3, additive-type UV absorbers will have spitting problems at high addition levels and cannot be used outdoors for a long time.

3.3. Preparation of polymer structure substrate

[Preparation Example 2-1]

100 g of polytetrahydrofuran PTMEG1000, 11 g of 1,4-butanediol, 0.15 wt % (based on the total weight of the reactants) of hindered phenol antioxidant Deox 105, 0.05 wt % (based on the total weight of the reactants) of benzofuranone antioxidant Revonox 501, 0.1 wt % (based on the total weight of the reactants) of organic phosphite antioxidant Deox 604, 0.5 wt % (based on the total weight of the reactants) of ultraviolet stabilizer Chiguard 1152 and 200 ppm of dibutyltin dilaurate were added to a reaction iron pot and heated to 110°C. Take another 55.5 grams of MDI and preheat it to 110°C, add it to the reaction tank and stir for 1 minute to react to obtain a thermoplastic aromatic polyurethane rubber block. Put the rubber block into an oven and bake it at 70°C for 24 hours, and then make a substrate with a thickness of 0.15 cm in the same way as described in Section 3.2.2.

[Preparation Example 2-2]

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 the total weight of the reactants) of hindered phenol-based antioxidant Deox 105, 0.05 wt % (based on the total weight of the reactants) of benzofuranone-based antioxidant Revonox 501, 0.1 wt % (based on the total weight of the reactants) of organic phosphite-based antioxidant Deox 604, and 200 ppm of dibutyltin dilaurate were added to a reaction iron pot and heated to 110° C. Take another 55.5 grams of MDI and preheat it to 110°C, add it to the reaction tank and stir for 1 minute to react to obtain a thermoplastic aromatic polyurethane rubber block. Put the rubber block into an oven and bake it at 70°C for 24 hours, and then make a substrate with a thickness of 0.15 cm in the same way as described in Section 3.2.2.

[Preparation Example 2-3]

The substrate of Preparation Example 2-3 was prepared in the same manner as Preparation Example 2-2, except that 0.5 wt% (based on the total weight of the reactants) of UV stabilizer Chiguard 228 (purchased from Chitai Technology) was additionally added.

[Preparation Example 2-4]

The substrate of Preparation Example 2-4 was prepared in the same manner as Preparation Example 2-2, except that 0.25 wt% (based on the total weight of the reactants) of UV stabilizer Chiguard 622 (purchased from Chi-Tai Technology) and 0.25 wt% (based on the total weight of the reactants) of UV stabilizer Chiguard 100 (purchased from Chi-Tai Technology) were additionally added.

3.4. Polymer structures

[Implementation Example 1]

The thermoplastic aromatic polyurethanes of Preparation Examples 1-5 to 1-7 were used to prepare high-efficiency light shielding layers, which contained 5%, 10%, and 20% by weight of reactive ultraviolet light absorbers, respectively, and had a thickness of only 20 microns. Under elevated temperature, the thermoplastic aromatic polyurethanes of Preparation Examples 1-5 to 1-7 were dissolved into a 20% solid content gel using dimethylacetamide (DMAC), and then diluted with methyl ethyl ketone (MEK)/toluene to form a coating solution with a solid content of about 10%. The coating solution was applied to a transparent glass and dried in an oven at 120°C to form a light shielding layer with a thickness of 20 microns. 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 weathering test. The results were as follows: (1) The YI value of the 20-micron light shielding layer according to 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 according to 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 according to 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 according to 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 UV absorber has not only extremely low chromaticity, but also excellent long-term resistance to light yellowing.

The removed light shielding layer is placed on the substrate of Preparation Example 2-1 to form a polymer structure. The weather resistance test of the polymer structure is carried out using the aforementioned method, and the results are recorded in Table 2-1 to Table 2-2.

Table 2-1: Outdoor sunlight weathering test of polymer structures

It can be seen from Table 2-1 to Table 2-2 that the polymer structure of the present invention has excellent weather resistance and can be used outdoors for a long time. In addition, as shown in Table 2-1, compared with the substrate of thermoplastic aromatic polyurethane without a light shielding layer (Preparation Example 2-1), the polymer structure of the present invention (that is, the polymer structure comprising the substrate of Preparation Example 2-1 and the light shielding layer of Preparation Examples 1-5 to 1-7) has significantly improved weather resistance and yellowing resistance.

[Example 2]

Using the same testing method as Example 1, the thermoplastic aromatic polyurethanes of Preparation Examples 1-5 and 1-6 were dissolved into a 20% solid content gel using DMAC, and then diluted with MEK/toluene to form a coating solution with a solid content of about 10%. The coating solution was applied to a transparent glass and dried in an oven at 120°C to form a light shielding layer with a thickness of 20 microns. 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 a polymer structure. The weathering test of the polymer structure was performed using the aforementioned method, and the results are recorded in Tables 2-3 to 2-6.

It can be seen from Table 2-3 to Table 2-6 that 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 additional UV 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 anti-yellowing properties.

3.5. Co-extruded polymer structures

[Implementation Example 3]

The thermoplastic aromatic polyurethane containing a reactive ultraviolet light absorber of Preparation Examples 1-5 and 1-6, the thermoplastic aromatic polyurethane (model: 90 AE, purchased from Huntsman) added with HALS (model: Chiguard 1152, purchased from Chitai Technology, with a content of 0.5 wt%), and polypropylene (model: PD943, purchased from LCY CHEMICAL CORP.) were co-extruded to form a three-layer co-extruded polymer structure, wherein the light shielding layer formed by the thermoplastic aromatic polyurethane of Preparation Examples 1-5 and 1-6 had a thickness of about 30 μm, the substrate formed by the thermoplastic aromatic polyurethane 90 AE had a thickness of about 120 μm, and the carrier formed by the polypropylene PD 943 had a thickness of about 125 μm. The weather resistance test of the co-extruded polymer structure was carried out using the above method, and the results are recorded in Table 3-1 and Table 3-2.

It can be seen from Table 3-1 and Table 3-2 that the polymer structures of the present invention prepared in different ways also have good weather resistance and can be used outdoors for a long time. Through the design of the present invention, the thermoplastic aromatic polyurethane, which is very easy to yellow due to light, can achieve excellent long-term weather resistance and yellowing resistance, solving the limitation of being excluded from use in outdoor items due to weather resistance and yellowing problems, expanding its industrial application range, and creating potential commercial value.

The above embodiments are only for illustrative purposes to illustrate the principle and efficacy of the present invention and to illustrate the technical features of the present invention, and are not intended to limit the scope of protection of the present invention. Any changes or arrangements that can be easily completed by anyone familiar with the present technology without violating the technical principle of the present invention are within the scope advocated by the present invention. Therefore, the scope of protection of the present invention is as listed in the attached patent application scope.

10:Polymer structure

11: Light shielding layer

12: Base material

Claims (6)

A polymer structure comprises 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, 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 a structural unit 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-oxy-3-benzofuranyl]phenyl-3,5-bis(1,1-dimethylethyl)-4-hydroxybenzoate, acid, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-, 4-(1,1-dimethylethyl)-2-[5-(1,1-dimethylethyl)-2,3-dihydro-2-oxo-3-benzofuranyl]phenyl ester), 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)amino]-6-(2-hydroxyethylamino)-1,3,5-triazine (2,4-bis[N-butyl-N-(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl)amino]-6-(2-hydroxyethylamine)-1,3,5-triazine), and the light shielding layer has a thickness of 5 microns to 200 microns, and 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 wt % to 20 wt % based on the total weight of the second polymer; and wherein the polymer structure has a visible light transmittance of 65% or more. The polymer structure as described in claim 1, wherein the light shielding layer at least covers the light-receiving surface of the substrate. The polymer structure as described in claim 1 or 2, wherein the substrate and the light shielding layer each independently contain additives selected from the following groups: defoaming agent, leveling wetting agent, thickener, dispersant, micronized wax, matting powder, antibacterial agent, metal oxide light shielding agent, light stabilizer, heat stabilizer, non-reactive UV absorber, monofunctional reactive UV absorber, antioxidant, filler, flame retardant, plasticizer, dye, pigment, brightener, antistatic agent, fluorescent whitening agent, anti-aging agent, metal stabilizer, acid absorber, anti-hydrolysis agent, wax, and combinations thereof. A use of a polymer structure as described in any one of claims 1 to 3, which is used to prepare a product that can resist ultraviolet light. The use as described in claim 4, wherein the product is selected from the following groups: transparent outer 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, display external viewing surfaces, films, sheets, and explosion-proof panels. The use as described in claim 4, wherein the product is selected from the following group: vehicle envelope, lampshade, housing of mobile device, vehicle housing, car lamp, surface material for vehicle interior, windshield, side window glass, window, door, filter, clothing, pants, coat, shoes, optical lens, optical element, photochromic lens, contact lens, roof film , roof tiles, roof pads, eaves, wall materials, floor materials, road construction components, pipeline materials, signs, sunshades, greenhouse covering films, backlights, windmill parts, aircraft transparent bodies, radar antenna covers, explosion-proof glass, bulletproof panels, transparent screen films, conductive films, microwave absorbing films, thermal transfer films, packaging films, and low-resistance films.