Enhanced thin metal paillette

Abstract

The utility model discloses an enhanced thin metal paillette. Comprising a metal reflecting layer; the thin metal paillette further comprises medium reflection enhancement film stacks symmetrically arranged on the two sides of the metal reflection layer, and the medium reflection enhancement film stacks are formed by alternately stacking a plurality of high-refractive-index medium layers and a plurality of low-refractive-index medium layers. And the dielectric layer close to one side of the metal reflecting layer is a low-refractive-index dielectric layer. According to the utility model, the metal is thinned by multilayer media, so that the reflectivity is enhanced, and the rigidity and brittle fracture of the metal are ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of thin metal sequins, in particular to an enhanced thin metal sequin. Background Art

[0002] In application environments where it is necessary to improve the gloss and reflectivity of the surface of an object or achieve a sparkling effect, such as paints, cosmetics, pigments, and coatings, metal sheets or thin layers are involved to achieve the target effect, but the size and shape of the metal sheets and metal particles will affect the coverage. When the metal sheet is too thick, many sheets will be oriented in a vertical state, resulting in the inability to evenly cover the entire plane, causing great scattering and diffraction, thereby reducing the reflective performance, and may also cause process problems such as spray gun clogging. When the metal sheet is too thin, microscopic defects will occur during use. For example, when the application surface is uneven, the metal sheet will also be correspondingly rough, and most metals will not undergo brittle fracture, but are more likely to undergo plastic deformation, which will reduce the reflectivity. Utility Model Content

[0003] In view of this, the purpose of the utility model is to provide an enhanced thin metal sequin. Based on the advantages and disadvantages of metal sheets, a method of multi-layer dielectric plus thin metal is proposed to enhance the reflectivity while ensuring the rigidity and brittle fracture of the metal.

[0004] According to one aspect of the utility model, there is provided a reinforced thin metal sequin, comprising a metal reflective layer;

[0005] The thin metal sequin also includes a dielectric reflection enhancement film stack symmetrically arranged on both sides of the metal reflection layer, the dielectric reflection enhancement film stack is formed by alternatingly stacking a plurality of high refractive index dielectric layers and a plurality of low refractive index dielectric layers; and the dielectric layer close to the side of the metal reflection layer is a low refractive index dielectric layer.

[0006] In the above technical scheme, a symmetrical enhanced reflection type thin metal sequin is proposed, which adopts a reflection enhancement film stack symmetrically distributed on both sides of the thin metal sheet. The introduction of the dielectric reflection enhancement film stack not only further improves the reflectivity of the central metal layer, but also improves the rigidity and brittle fracture of the metal sequin. Structurally, a combination of multi-layer dielectric enhanced reflection unit + metal reflection layer + multi-layer dielectric enhanced reflection unit is used to achieve high reflectivity in the visible light band. Compared with previous studies, the method proposed in this paper has a higher reflectivity while also ensuring the rigid and brittle characteristics of the metal sequin. These advantages make this metal sequin widely used in application scenarios such as coatings, paints, cosmetics, etc. that require improved gloss or reflection performance.

[0007] In some embodiments, the material of the metal reflective layer is one of aluminum and silver.

[0008] In the above technical solution, aluminum and silver have high reflectivity in the visible light band, the price of metallic aluminum is relatively low and the film layer is firm and stable.

[0009] In some embodiments, the thickness of the metal reflective layer is 50 nm-300 nm.

[0010] In the above technical solution, the reflectivity of the metal film generally tends to be stable when the thickness is greater than 50nm.

[0011] In some embodiments, the optical thickness of the dielectric layer is N QWOT, where N is a positive integer.

[0012] In the above technical solution, the enhanced reflection added to the metal film layer based on the dielectric film stack is theoretically derived with the regular quarter optical thickness QWOT as the thickness unit. According to the derivation of Formula 1 and Formula 2 below, the admittance of the combined film layer is a conclusion based on the regular film system structure. In the theory of multilayer dielectric reflective film superposition, when the optical thickness of the high and low refractive index dielectric film layers is one quarter, the highest reflectivity and the widest reflection bandwidth are obtained, so generally optical multilayer dielectric films are also mostly based on one quarter optical thickness as a reference.

[0013] In some embodiments, the reflection enhancement unit often uses two dielectric materials with a large difference in refractive index.

[0014] In the above technical solution, the difference between the high and low refractive indices ranges from 0 to 2. For example, the refractive index of tantalum oxide is 2.15, the refractive index of silicon oxide is 1.45, and the refractive index difference is 0.7. For example, tantalum oxide (Ta2O5) and silicon oxide (SiO2) are selected as two dielectric materials with a large difference in refractive index to form a basic reflection unit. The metal dielectric combination improves the reflectivity, and two high and low refractive index dielectric film layers need to be superimposed. The greater the refractive index difference, the greater the equivalent admittance Y obtained. The greater Y is, see Formula 1 below, the higher the reflectivity R achieved, so a combination of two materials with a large difference in refractive index should be selected.

[0015] In some embodiments, the dielectric layer has a thickness of 20 nm-200 nm.

[0016] In the above technical solution, high reflectivity of metal is achieved in the visible light band, and the central wavelength range is between 400-700. The extreme values ​​at both ends are taken. If the central wavelength is 400nm, the quarter optical thickness is 100nm. If the maximum refractive index of the high refractive index material is 3, the corresponding physical thickness is 33nm; if the central wavelength is 700nm, the quarter optical thickness is 175nm, the corresponding minimum refractive index is 1.2, and the corresponding physical thickness is 146nm, so the thickness range of high and low refractive index medium materials is 20-200nm.

[0017] In some embodiments, the material of the high refractive index medium layer is a mixture of one or more of tantalum oxide, titanium oxide, hafnium oxide, silicon nitride, and zinc sulfide.

[0018] In the above technical solution, the high refractive index medium layer should be made of non-absorbent or low-absorbent material in the visible light band to achieve the effect of enhancing reflection, and the outermost high refractive index medium layer can be made of silicon nitride to improve the wear resistance of the thin metal sequins.

[0019] In some embodiments, the material of the low refractive index medium layer is a mixture of one or more of silicon oxide, magnesium fluoride, and yttrium fluoride.

[0020] In the above technical solution, the low refractive index medium layer should be made of a material with no absorption or low absorption in the visible light band to achieve the effect of enhancing reflection. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0022] Figure 1 This is a schematic diagram of the symmetrical structure of an embodiment of an enhanced thin metal sequin of the utility model;

[0023] Figure 2 This is a reflection spectrum diagram of an enhanced thin metal sequin embodiment of the utility model at normal incidence when the aluminum sequin is enhanced;

[0024] Figure 3 This is a reflection spectrum diagram of the enhanced silver sequins at normal incidence in the second embodiment of the enhanced thin metal sequins of the utility model;

[0025] Figure 4 This is a reflection spectrum diagram of an enhanced thin metal sequin embodiment 3 of the utility model at normal incidence of an enhanced aluminum sequin;

[0026] Figure 5 This is a reflection spectrum diagram of the enhanced copper sequins at normal incidence in the fourth embodiment of the enhanced thin metal sequins of the utility model;

[0027] Figure 6 This is a reflection spectrum diagram of the enhanced thin metal sequin in the fifth embodiment of the utility model at normal incidence. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It is particularly noted that the following embodiments are only used to illustrate the present invention, but do not limit the scope of the present invention. Similarly, the following embodiments are only partial embodiments of the present invention rather than all embodiments. All other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] The utility model provides an enhanced thin metal spangle sheet. Based on the advantages and disadvantages of metal sheets, a method of multi-layer dielectric plus thin metal is proposed to enhance reflectivity while ensuring the rigidity and brittle fracture of the metal.

[0030] See also Figure 1 , a reinforced thin metal sequin, comprising a metal reflective layer;

[0031] The thin metal sequin also includes a dielectric reflection enhancement film stack symmetrically arranged on both sides of the metal reflection layer, the dielectric reflection enhancement film stack is formed by alternatingly stacking a plurality of high refractive index dielectric layers and a plurality of low refractive index dielectric layers; and the dielectric layer close to the side of the metal reflection layer is a low refractive index dielectric layer.

[0032] In this embodiment, a reflection enhancement film stack symmetrically distributed on both sides of the thin metal sheet is used. The introduction of the dielectric reflection enhancement film stack not only further improves the reflectivity of the central metal layer, but also improves the rigidity and brittle fracture of the metal sequins. Structurally, a combination of a multi-layer dielectric enhancement reflection unit + a metal reflection layer + a multi-layer dielectric enhancement reflection unit is used to achieve high reflectivity in the visible light band. Compared with previous studies, the method proposed in this article has a higher reflectivity while also ensuring the rigid and brittle characteristics of the metal sequins. These advantages make this metal sequin widely used in application scenarios such as coatings, paints, cosmetics, etc. that require improved gloss or reflective performance.

[0033] In this embodiment, a symmetrical structure of a multilayer dielectric reflection enhancement unit + a metal reflection layer + a multilayer dielectric enhancement reflection unit is adopted. The metal reflection layer material can be selected from metals and transition metal materials or mixtures thereof with high reflectivity in the visible light band, such as aluminum (Al), silver (Ag), gold (Au), copper (Cu), nickel (Ni), rhodium (Rh), etc. The preparation process of these materials is simple and the material properties are stable. The multilayer dielectric enhancement reflection unit adopts one or several high and low refractive index materials to achieve high reflectivity in the visible light band and enhance the reflectivity. The dielectric material is usually selected from non-absorption or low absorption materials in the visible light band to achieve the effect of enhancing reflection. The high refractive index material can be selected from one or a mixture of at least two of tantalum oxide (Ta2O5), titanium oxide (TiO2), hafnium oxide (HfO2), silicon nitride (Si3N4), zinc sulfide (ZnS), etc., and the low refractive index material is generally selected from one or a mixture of at least two of silicon oxide (SiO2), magnesium fluoride (MgF2), yttrium fluoride (YF3).

[0034] For thin film-based effect materials used in coatings, paints, cosmetics and other fields, the multi-layer thin film structure can be directly prepared by physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), sol-gel and other deposition processes. Considering the application requirements, the structure is designed to be a symmetrical structure to ensure that the front and back incident surfaces of the multi-layer thin film have the same high reflectivity in the visible light band. The thin film structure is deposited on the release layer, and the multi-layer enhanced reflection film is peeled off from the substrate by dissolving the release layer to form a metal sequin composed of a single multi-layer thin film. The film fragments are dried, crushed and other processes to be processed into micro-element metal sequins that can be added to paints and coatings.

[0035] In the present embodiment, the substrate material is highly polished glass, polished stainless steel, or polished mirror aluminum. As required, the substrate may also be one of optical plastic substrates such as polyethylene terephthalate (PET), triacetyl cellulose (TAC), polymethyl methacrylate (PMMA), polycarbonate / polymethyl methacrylate composite material (PC / PMMA), polyimide (PI), polypropylene (PP), polyvinyl chloride (PVC), polyvinyl butyral (PVB), ethylene vinyl acetate copolymer (EVA), or polyurethane elastomer (TPU), polytetrafluoroethylene (PTFE), fluoroethyl propylene (FEP), or polyvinyl difluoride (PVDF).

[0036] Common materials for metal reflective layers are aluminum (Al), silver (Ag), gold (Au), and copper (Cu). Aluminum and silver have high reflectivity in the visible light band. The price of metal aluminum is relatively low and the film layer is firm and stable, so it is the most widely used material. The metal reflective layer uses materials with high reflectivity in the visible light band, which simplifies the reflective film structure. Multilayer dielectric reflective layers can often only have high reflectivity in a narrow band near the target wavelength, and it is difficult to achieve high reflectivity in the entire visible light band, or in order to achieve high reflectivity in the entire band, the design structure becomes complicated, but the metal reflective layer can achieve high reflectivity in the entire band in the simplest way. The thickness of the metal reflective layer is controlled at 30-300nm, and the optimal thickness is 50-200nm.

[0037] In this embodiment, in order to further improve the reflectivity of the metal reflective film, several dielectric layers of a certain thickness can be plated on the outside of the film to form a metal-dielectric reflective film to achieve high reflection of the target band. For an equal-thickness periodic film system, that is, the thickness of each dielectric layer is 1 / 4 of the central wavelength optical thickness or an integer multiple thereof, the film system structure is hereinafter referred to as a regular 1 / 4 wavelength film stack structure. The reflection enhancement unit often uses two dielectric materials with a large refractive index difference, such as tantalum oxide (Ta2O5) and silicon oxide (SiO2). These two dielectric materials with a large refractive index difference constitute the basic reflection unit. The regular 1 / 4 wavelength film stack symmetrical thin film structure is (HL) P M(LH) P , the reflectivity of the film system is:

[0038]

[0039] Where Y is the target wavelength admittance, which is related to the optical parameters of each layer of material and the number of stacked layers. For example, for a metal with a complex refractive index of n-ik, two layers of dielectric films with a thickness of λ0 / 4 and refractive indices of n1 and n2 are plated on the metal film, and n2 is close to the metal. The admittance of wavelength λ0 at vertical incidence is

[0040] Substituting into formula 1, we get:

[0041]

[0042] Let n1>n2, the reflectivity is R 12 , the reflectivity when n2>n1 is R 21 According to formula 2, when the two dielectric materials are fixed, R 12 >R 21That is, in order to obtain a high reflectivity film system, the material close to the metal should be a low refractive index medium. Only when the low refractive index medium layer n2 is close to the metal substrate, the reflectivity R12 obtained is greater than the reflectivity R21 obtained when the high refractive index medium layer n1 is close to the metal substrate. The letters L and H represent the low and high refractive index medium materials respectively. The thickness of each layer of the medium layer is controlled at 20-400nm, and the optimal thickness is 50-300nm.

[0043] The multilayer dielectric reflective layer in the present invention is obtained by further computer optimization based on the regular 1 / 4 wavelength film stack symmetrical film structure. The film system structure can adopt an equal thickness periodic film system, such as (LH)^S, or a non-equal thickness periodic film system, such as (aLbH)^S, where a and b are positive numbers that are not all 1, and the value range of a is a positive integer.

[0044] Embodiment 1

[0045] A symmetrical metal sequin based on metal Al is composed of metal material M (Al), high refractive index dielectric material H (Ta2O5), and low refractive index dielectric material L (MgF2). The dielectric material H (Ta2O5) and the dielectric material L (MgF2) are superimposed to form a two-layer reflection enhancement unit (LH). The specific thickness of each layer is given in the following table.

[0046] Number of layers Layer1 H Layer2 L Layer3 M Layer4 L Layer5 H Physical thickness (nm) 59.31 94.18 150.00 94.18 59.31

[0047] According to the given thickness value, a metal sequin with high reflectivity at 400nm-700nm can be prepared. The average reflectivity of a single layer of metal aluminum at 400nm-700nm is 91.5%. With this enhanced symmetrical structure, the average reflectivity is 95.5%. Figure 2 As shown, a reflectivity of 4% is mentioned.

[0048] Embodiment 2

[0049] A symmetrical metal sequin based on metal Ag is composed of metal material M (Ag), high refractive index dielectric material H (Si3N4), and low refractive index dielectric material L (Al2O3). The dielectric material H (Si3N4) and the dielectric material L (Al2O3) are superimposed to form a two-layer reflection enhancement unit (LH). The outermost layer of the multi-layer reflective metal sequin adopts Si3N4 material, which has good wear resistance and can greatly improve the rigidity and wear resistance of the metal sequin. The specific thickness of each layer is given in the following table.

[0050] Number of layers Layer1 H Layer2 L Layer3 M Layer4 L Layer5 H Physical thickness (nm) 53.66 85.44 100.00 85.44 53.66

[0051] According to the given thickness value, a metal sequin with high reflectivity and good wear resistance at 480nm-700nm can be prepared. The average reflectivity of a single layer of metal silver at 480nm-700nm is 96.5%. With this enhanced symmetrical structure, the average reflectivity is 98.8%. Figure 3 As shown, a reflectivity of 2% is mentioned.

[0052] Embodiment 3

[0053] A symmetrical metal sequin based on metal Al is composed of metal material M (Al), high refractive index dielectric material H (Si3N4), and low refractive index dielectric material L (SiO2). The dielectric material H (Si3N4) and dielectric material L (SiO2) are superimposed to form a 4-layer reflection enhancement unit (LH). The outermost layer of the multi-layer reflective metal sequin adopts Si3N4 material, which has good wear resistance. The combination of Si3N4 material and SiO2 material can further improve the rigidity strength of the metal aluminum film, and can greatly improve the rigidity and wear resistance of the metal sequin. The specific thickness of each layer is given in the following table. The single-sided 4-layer dielectric structure can obtain a higher reflectivity level in the local band.

[0054] Number of layers Layer1 H Layer2 L Layer3 H Layer4 L Layer5 M Physical thickness (nm) 67.08 94.18 67.08 94.18 100.00 Number of layers Layer6 L Layer7 H Layer8 L Layer9 H Physical thickness (nm) 94.18 67.08 94.18 67.08

[0055] According to the given thickness value, a thin film sequin with high reflectivity at 480nm-700nm can be prepared. The average reflectivity of a single layer of metal aluminum at 480nm-700nm is 91.1%. With this enhanced symmetrical structure, the average reflectivity is 96.6%. Figure 4 As shown, a reflectivity of 5% is mentioned.

[0056] Embodiment 4

[0057] A symmetrical metal sequin based on metal Cu, the reflection of copper is concentrated in the long-wave red band, the reflection of copper in the blue-green band of visible light 400nm-550nm is about 50%, and the reflectivity in the orange-red band of 600-700nm can reach about 90%, showing a metallic bright copper color. The multi-layer metal sequin structure is composed of metal material M (Cu), high refractive index dielectric material H (Si3N4), and low refractive index dielectric material L (SiO2). The dielectric material H (Si3N4) and the dielectric material L (SiO2) are superimposed to form a two-layer reflection enhancement unit (LH). The specific thickness of each layer is given in the following table.

[0058] Number of layers Layer1 H Layer2 L Layer3 M Layer4 L Layer5 H Physical thickness (nm) 68.35 95.92 100.00 95.92 68.35

[0059] According to the given thickness value, a metal film sequin with a linear reflectivity increase from 400nm to 700nm can be prepared, such as Figure 5As shown, the reflectivity of the multi-layer metal sequin is 10% at 400nm, 65% at 500nm, 92% at 600nm, and 97% on average in the red band of 600-700nm. The spectral reflectivity increases linearly from short wave to long wave. The overall color of the metal sequin is brass. The outermost layer of the multi-layer reflective metal sequin adopts Si3N4 material, which has good wear resistance. The combination of Si3N4 material and SiO2 material can further improve the rigidity strength of the metal copper film, and can greatly improve the rigidity and wear resistance of the metal sequin.

[0060] Embodiment 5

[0061] A symmetrical metal sequin based on metal Au is composed of metal material M (Au), high refractive index dielectric material H (ZnS), and low refractive index dielectric material L (YF3). The dielectric material H (ZnS) and the dielectric material L (YF3) are superimposed to form a two-layer reflection enhancement unit (LH). The specific thickness of each layer is given in the following table.

[0062] Number of layers Layer1 H Layer2 L Layer3 M Layer4 L Layer5 H Physical thickness (nm) 64.35 100.40 150.00 100.40 64.35

[0063] According to the given thickness value, a pure gold metal sequin film with a specific lower reflectivity of about 10% in the 400nm-500nm blue band and a higher reflectivity of about 97% in the 550-700nm yellow-green and red band can be prepared, such as Figure 6 As shown, the multi-layer gold metal sequins have higher color saturation and higher brightness than the reflection spectrum of a single-layer metal gold film. At the same time, the use of the dielectric film layer ZnS can further improve the rigidity and density of the film.

[0064] The above descriptions are only some embodiments of the present invention, and do not limit the protection scope of the present invention. Any equivalent device or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. An enhanced thin metal sequin, characterized in that: including a metal reflective layer; The thin metal sequin further comprises a dielectric reflection enhancement film stack symmetrically arranged on both sides of the metal reflection layer, wherein the dielectric reflection enhancement film stack is formed by alternately stacking a plurality of high refractive index dielectric layers and a plurality of low refractive index dielectric layers; and the dielectric layer close to one side of the metal reflection layer is a low refractive index dielectric layer; The dielectric reflection enhancement film stack structure is (aLbH)^S, where a and b are positive numbers that are all 1 or not all 1.

2. The enhanced thin metal sequin according to claim 1, characterized in that: The material of the metal reflective layer is one of aluminum, silver and copper.

3. The enhanced thin metal sequin according to claim 1, characterized in that: The thickness of the metal reflective layer is 30nm-300nm.

4. The enhanced thin metal sequin according to claim 1, characterized in that: The optical thickness of the dielectric layer is N QWOT, where N is a positive integer.

5. A reinforced thin metal sequin as claimed in claim 1 or 4, characterized in that: The refractive index difference between the high refractive index medium layer and the low refractive index medium layer is 0-2.

6. The enhanced thin metal sequin according to claim 1, characterized in that: The thickness of the dielectric layer is 20 nm-200 nm.

7. The enhanced thin metal sequin according to claim 1, characterized in that: The material of the high refractive index medium layer is one of tantalum oxide, titanium oxide, hafnium oxide, silicon nitride and zinc sulfide.

8. The enhanced thin metal sequin according to claim 1, characterized in that: The material of the low refractive index medium layer is one of silicon oxide, magnesium fluoride and yttrium fluoride.

Images