Low static optical removable lens stack

Abstract

The removable lens stack may include a base layer including a substrate and an antistatic coating including quaternary ammonium cations on a first surface of the substrate, and one or more removable lens layers laminated on the base layer. Each removable lens layer may include a substrate, an antistatic coating including quaternary ammonium cations on a first surface of the substrate, and an adhesive on a second surface of the substrate opposite the first surface. The one or more removable lens layers may be laminated on the base layer such that the second surface of the substrate of each removable lens layer faces the first surface of the substrate of the immediately preceding layer. The refractive indices of the substrate of the base layer, the substrate of each removable lens layer, and the adhesive of each removable lens layer may be matched (within 0.2).

Description

[Technical Field]

[0001] The present invention relates to a low static optical removable lens stack. [Background technology]

[0002] Current optical removable lens stacks, such as those currently manufactured by Racing Optics, Inc. of Las Vegas, Nevada, have become the industry standard for vision and surface protection. The disclosure of which is expressly incorporated herein by reference. One industry sector where such lens stacks are not widely used is sandblasting applications. Sandblasters wear protective helmets with rigid face shields. Their face shields wear very quickly, impairing their vision. Ideally, they would incorporate current removable lens stacks into face shields and remove a layer from the stack when their vision is impaired. However, removing a layer from the stack has been found to generate static electricity, causing airborne particles to adhere to the remaining lens stack surface and face shield. Each time an outer layer is removed from the lens stack, more static electricity is generated and released. For conventional lens stacks to be used effectively during sandblasting and in other industrial and medical environments where static charges are undesirable, static electricity must be eliminated.

[0003] Static electricity is the name given to the buildup of electrical charge on the surface of an insulator (a poor conductor of electricity). It is a surface phenomenon that occurs when two or more surfaces come into contact with each other and are then separated. These charges are then released when each lens layer is removed. Polymers / plastics tend to have a negative charge. Air and skin tend to be positively charged. Surfaces with the same polarity repel each other. Surfaces with opposite polarities attract each other. This is why you feel a static shock when removing two pieces of plastic from each other. Negative ions jump to the nearest positive ions in the air and on your skin. Summary of the Invention [Problem to be solved by the invention]

[0004] SUMMARY OF THE INVENTION The present disclosure contemplates various systems and methods for overcoming the above-noted shortcomings associated with the related art. [Means for solving the problem]

[0005] One aspect of an embodiment of the present disclosure is a removable lens laminate. The removable lens laminate may include a base layer including a substrate and an antistatic coating including a quaternary ammonium cation, the antistatic coating being provided on a first side of the substrate. The removable lens laminate may further include one or more removable lens layers laminated on the base layer, each removable lens layer including a substrate, an antistatic coating including a quaternary ammonium cation, and an adhesive, the antistatic coating being provided on a first side of the substrate, and the adhesive being provided on a second side of the substrate opposite the first side. The one or more removable lens layers may be laminated on the base layer such that the second side of the substrate of each removable lens layer faces the first side of the substrate of the immediately preceding layer of the base layer and the one or more removable lens layers. The refractive index of the substrate of the base layer, the substrate of each removable lens layer, and the adhesive of each removable lens layer may match within 0.2.

[0006] Each removable lens layer may further comprise an adhesion-promoting treatment on the second surface of the substrate between the substrate and the adhesive. Each removable lens layer may be corona-treated on the second surface of the substrate. The base layer may comprise an adhesive, the adhesive being provided on the second surface of the substrate opposite the first surface. The base layer may further comprise an adhesion-promoting treatment on the second surface of the substrate between the substrate and the adhesive. The base layer may be corona-treated on the second surface of the substrate. The substrate of each removable lens layer may comprise a polyethylene terephthalate (PET) film or a thermoplastic polyurethane (TPU) film. The substrate of the base layer may comprise a PET film or a TPU film.

[0007] Another aspect of an embodiment of the present disclosure is a sandblasting helmet. The sandblasting helmet may include a face shield and one or more removable lens layers laminated on the face shield. Each removable lens layer may include a substrate, an antistatic coating including a quaternary ammonium cation, and an adhesive, where the antistatic coating is provided on a first surface of the substrate and the adhesive is provided on a second surface of the substrate opposite the first surface. The one or more removable lens layers may be laminated to the face shield such that the second surface of the substrate of a first removable lens layer of the one or more removable lens layers faces the face shield, and the second surface of the substrate of each removable lens layer after the first removable lens layer faces the first surface of the substrate of the immediately preceding removable lens layer of the one or more removable lens layers. The refractive index of the substrate of each removable lens layer may match (e.g., within 0.2) the refractive index of the adhesive of each removable lens layer.

[0008] Each removable lens layer may further comprise an adhesion promoting treatment on the second surface of the substrate between the substrate and the adhesive. Each removable lens layer may be corona treated on the second surface of the substrate. The substrate of each removable lens layer may comprise a PET film or a TPU film.

[0009] Another aspect of an embodiment of the present disclosure is a method for manufacturing a removable lens laminate. The method may include providing an antistatic coating on a first substrate, the antistatic coating comprising a quaternary ammonium cation. The method may further include providing an adhesive on a second substrate, and laminating the second substrate onto the first substrate such that the adhesive on the second substrate faces the antistatic coating on the first substrate. The refractive indices of the first substrate, the second substrate, and the adhesive may be matched (e.g., within 0.2).

[0010] The method may further comprise the step of providing an adhesion promoting treatment on the second substrate prior to the adhesive providing step. The method may further comprise the step of corona treating the second substrate prior to the adhesive providing step. The first and / or second substrate may comprise a PET film or a TPU film.

[0011] These and other features and advantages of the various embodiments disclosed herein may be better understood with regard to the following description and drawings. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 illustrates a removable lens stack applied to a face shield of a sandblasting helmet according to one embodiment of the present disclosure. [Figure 2] 2 is a cross-sectional view of the removable lens laminate and face shield taken along line 2-2 in FIG. 1. [Figure 3]FIG. 10 is another cross-sectional view of the removable lens laminate and face shield with the outermost layer of the removable lens laminate peeled away. [Figure 4] FIG. 10 is a diagram illustrating an example of an operational flow according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0013] The present disclosure encompasses various embodiments of a removable lens laminate that can be attached to or used as a face shield for a sandblasting helmet, as well as methods of making and using the same. The detailed description set forth below in connection with the accompanying drawings is intended as a description of some currently contemplated embodiments and is not intended to represent the only manner in which the disclosed invention can be deployed or utilized. The description describes functions and features in connection with the illustrated embodiments. It may be understood that the same or equivalent functions may be achieved by various embodiments that are, however, also intended to be encompassed within the scope of the present disclosure. It is further understood that relative terms such as "first" and "second" are used only to distinguish one entity from another entity and do not necessarily require or imply any actual such sequential relationship between such entities.

[0014] FIG. 1 shows a removable lens laminate 100 applied to a face shield 10 of a sandblasting helmet 20 according to an embodiment of the present disclosure. FIG. 2 shows a cross-sectional view thereof. The removable lens laminate 100 may include a base layer 110. The base layer 110 may be attached (e.g., mechanically or with an adhesive) to the face shield 10, particularly for use in sandblasting or other activities that may benefit from avoiding static buildup, or to other surfaces such as a goggle lens or visor or transparent window of a helmet, hood, or gown. Alternatively, the base layer 110 of the removable lens laminate 100 may itself function as a lens, visor, face shield, or other surface, for example, by attaching its periphery to the frame of a helmet, hood, gown, goggles, or other article. Laminated on the base layer 110, the removable lens laminate 100 may further include one or more removable lens layers 120a, 120b, etc. (collectively 120). Each comprises a substrate 122, such as a polyethylene terephthalate (PET) or thermoplastic polyurethane (TPU) film, and an adhesive 124 for adhering the removable lens layer 120 to the previous adhesive lens layer 120 (or, in the case of the innermost removable lens layer 120, to the base layer 110). When debris accumulates on the outermost removable lens layer 120 during sandblasting or other activities, or when layer 120 is damaged, such as when layer 120 is punctured, the wearer can simply peel it off to reveal the next fresh lens layer 120 (or base layer 110) underneath. Depending on the number of removable lens layers 120 in the stack, the process can be repeated several times before the stack 100 needs to be replaced.

[0015] FIG. 3 is another cross-sectional view of the removable lens laminate 100 and face shield 10, with the outermost layer 120b of the removable lens laminate 100 peeled away. To prevent static buildup that may result from peeling away each removable lens layer 120, each removable lens layer 120 may further comprise an antistatic coating 126, as shown in FIGS. 2 and 3. The antistatic coating 126 may contain positively charged ions 30 (e.g., polyatomic ions such as quaternary ammonium cations (QACs)), which may be dispersed in, for example, an acrylic polymer or a urethane polymer. By embedding cations in the mating surfaces between layers in this manner, static electricity resulting from separation of the negatively charged (typically resin) lens 122 can be neutralized. As shown in FIG. 3, for example, the antistatic coating 126 of the removable lens layer 120a remaining on the laminate 100 is in direct contact with the removable adhesive 124 of the removable lens layer 120b being peeled away. The cations 30 embedded in the antistatic coating 126 attract the anions 40 that are released from the removable lens layer 120b when the layer 120 is peeled away. While the anions 40 would normally create a net negative charge on the remaining removable lens layer 120a, thereby undesirably attracting dust and debris from the air, the anions 40 can instead be attracted to and neutralized by the cations 30 of the remaining removable lens layer 120a. In this way, when the layer 120 is removed from the stack 100, most, if not all, of the charge can be completely removed, thereby enabling a neutralized embodiment for sandblasting or other activities where static buildup is undesirable.

[0016] In addition to the antistatic coating 126, various other surface treatments may be applied to the removable lens layer 120, typically in the form of very thin coatings that help promote adhesion on the surface of the lens layer 120. Of particular use in the context of the disclosed removable lens laminate 100, each removable lens layer 120 may further comprise an adhesion-promoting treatment 128 between the substrate 122 and the adhesive 124. The adhesion-promoting treatment 128 may be, for example, a very thin (e.g., 5 nm-10 nm) rough coating of acrylic or polyurethane. Alternatively, the substrate 122 may be subjected to a corona treatment to promote adhesion. Promoting the adhesion of the substrate 122 can ensure that the adhesive 124 remains with the substrate 122 when a given layer (e.g., layer 120b) is removed from the layer below (e.g., layer 120a). Advantageously, this can prevent the transfer of unwanted residue to the next layer 120, which could impair the vision of the sandblaster or other wearers of the lens stack 100. Such clean removal can typically result in an increased buildup of static electricity, making the disclosed antistatic coatings 126 particularly beneficial in the context of removable lens layers 120 that have been treated to promote adhesion.

[0017] Similar to the removable lens layer 120, the base layer 110 of the removable lens laminate 100 may comprise a substrate 112 and an antistatic coating 116, which may be the same as the substrate 122 and antistatic coating 126 of each removable lens layer 120. When the base layer 120 is attached to the face shield 10 or other surface, the base layer 110 may further comprise an adhesive 114 (e.g., a self-wetting removable adhesive) and, optionally, an adhesion-promoting treatment 118, which may be the same as the adhesive 124 and adhesion-promoting treatment 128 of each removable lens layer 120. To keep optical distortion as low as possible, the refractive indices of the substrates 112, 122 and any adhesives 114, 124 used may be matched (e.g., within 0.2), as explained in U.S. Pat. No. 9,295,297, entitled "Adhesive Mountable Stack of Removable Layers," the entire contents of each of which are incorporated herein by reference.

[0018] Figure 4 is an example operational flow according to one embodiment of the present disclosure. The operational flow of Figure 4 may serve as an example method for manufacturing the removable lens stack 100 described with respect to Figures 1-3. The operational flow may begin with providing the base layer 110 and the substrates 112, 122 used in each removable lens layer 120 (step 410). As mentioned above, the substrates 112, 122, which may be made of PET (e.g., biaxially oriented PET or BoPET) or TPU, may be selected for specific modulation transfer function (MTF) data or may be fabricated in a continuous or multiple batch process while actively monitoring MTF data, as described in U.S. Patent Application Publication Nos. 2021 / 0162645 and 2022 / 0032591, entitled "Method and Apparatus for Reducing Non-Normal Incidence Distortion in Glazing Films," or U.S. Patent Application Publication No. 2021 / 0283994, entitled "Protective Barrier for Safety Glazing," the entire contents of each of which are incorporated herein by reference. In this regard, providing the substrate 112, 122 may include, for example, melting a resin, extruding the molten resin through a die to produce a film, and cooling the film. Examples of TPU films can be found, inter alia, in commonly owned U.S. patent application Ser. No. 17 / 937,371, entitled "Multi-layer Windshield Film having Progressive Thickness Layers," the entire contents of which are incorporated herein by reference.

[0019] Each substrate 112, 122 may be coated on one side with an antistatic coating 116, 126 (step 420). The antistatic coating 116, 126 may include an acrylic or urethane polymer having positively charged ions 30 dispersed therein, which may be coated onto the substrate by, for example, spin coating, dip coating, or vacuum deposition. While the ions 30 may be the same as those found in consumer products such as dryer sheets or hair conditioners, they may advantageously be dispersed in a very thin (e.g., 5 nm-10 nm), optically transparent coating 116, 126, which may be refractive index matched (e.g., within 0.2) to the substrate 112, 122 to reduce optical distortion. On the opposite side, each removable lens layer substrate 122 (and optionally base layer substrate 112) may further comprise an adhesion-promoting treatment 128, 118 (step 430), such as an acrylic or polyurethane rough coating or a corona treatment, and then be coated with an adhesive 124, 114 (step 440), which is preferably wet-deposited but may be applied according to any suitable method, including spin-coating, dip-coating, or vacuum deposition. The adhesive 114, 124 may be a wet-mount adhesive, such as those disclosed in U.S. Pat. Nos. 9,128,545, 9,274,625, and 10,620,670, all entitled "Touch Screen Shield," or a dry-mount adhesive, such as those disclosed in the aforementioned U.S. Pat. No. 9,295,297, the entire contents of each of which are incorporated herein by reference. The adhesives 114, 124 may be acrylic or silicone adhesives, such as acrylic pressure sensitive adhesives (PSA) or silicone PSA, and in particular may be optically clear adhesives (OCA).

[0020] 4 may continue with laminating one or more of the resulting lenses 120, comprising a substrate 122, adhesive 124, antistatic coating 126, and optional adhesion-promoting treatment 128, onto a base layer 110, comprising a substrate 112 and antistatic coating 116 (and in some cases, an adhesive 114 with an optional adhesion-promoting treatment 118), to produce a removable lens stack 100 (step 450). Exemplary lamination and adhesive curing processes that may be used in connection with producing the removable lens stack 100 are described in commonly owned U.S. patent application Ser. No. 17 / 823,413, entitled "Stack of Sterile Peelable Lenses with Low Creep," the entire contents of which are incorporated herein by reference. If an adhesive 114 is used in the base layer 110, a release liner may be used to protect the adhesive 114 before applying the removable lens stack 100 onto a face shield or other article.In addition to the substrates 112, 122, adhesives 114, 124, antistatic coatings 116, 126, and adhesion promoting treatments 118, 128 described herein, the base layer 110 and / or each removable lens layer 120 may contain other layers or additives, such as hard coatings as described in the aforementioned U.S. Patent Application Publication No. 2021 / 0283994, antireflective coatings as described in U.S. Patent Application Publication No. 2020 / 0124768 entitled "Transparent Covering Having Anti-Reflective Coatings," thermochromic films as described in U.S. Patent Application Publication No. 2021 / 0070017 entitled "Nano Particle Solar Control Film," and low haze UV ​​blocking removable lens laminates. Nos. 17 / 342,373 and 17 / 938,308, entitled "Low Reflectance Removable Lens Stack," and / or a fluoropolymer coating, such as described in U.S. Pat. No. 11,307,329, entitled "Low Reflectance Removable Lens Stack," and / or a coating of different reflectivity, such as described in U.S. Pat. Nos. 10,427,385, 11,141,959, entitled "Low Reflectance Optical Web," and U.S. Patent Application Publication No. 2021 / 0402744, the entire contents of each of which are incorporated herein by reference.To keep optical distortion as low as possible, the refractive indices of the substrates 112, 122, adhesives 114, 124, antistatic coatings 116, 126, adhesion-promoting treatments 118, 128, and any other layers or additives in each layer 110, 120, as well as the refractive index between each of the layers 110, 120 of the laminate 100, can be matched (e.g., within 0.2) as described in the aforementioned U.S. Pat. No. 9,295,297.

[0021] 2 and 3 show two removable lens layers 120 laminated onto the base layer 110 to form the removable lens stack 100. However, it is contemplated that there may be more than two removable lens layers 120 (e.g., three, four, or more), or only a single removable lens layer 120. It should be noted that not all removable lens layers 120 need be identical. For example, for the outermost layer 120, increased static charge buildup caused by prior removal of the layer 120 is not a concern, so the outermost removable lens layer 120 may omit the antistatic coating 126. It is also contemplated that the removable lens layer 120 may have peripheral tabs to facilitate peeling, which may vary in thickness or location along the periphery of the layer 120, as described, for example, in the aforementioned U.S. patent application Ser. No. 17 / 937,371. In this regard, an example system that may allow for easy removal of the removable lens laminate 100 when attached to a face shield or other article is described in U.S. Patent Application Publication No. 2022 / 0304412, entitled "Tearoff Tab Tensioner," the entire contents of which are incorporated herein by reference.

[0022] The above description is provided by way of example, not limitation. Given the above disclosure, those skilled in the art will be able to devise variations that are within the scope and spirit of the invention disclosed herein. Furthermore, the various features of the embodiments disclosed herein can be used alone or in varying combinations with each other and are not intended to be limited to the specific combinations described herein. Therefore, the scope of the claims should not be limited by the embodiments shown.

Claims

1. A removable lens stack, comprising: a base layer comprising a substrate and an antistatic coating comprising a quaternary ammonium cation, the antistatic coating being provided on a first surface of the substrate; one or more removable lens layers laminated on the base layer, each removable lens layer comprising a substrate, an antistatic coating comprising a quaternary ammonium cation, and an adhesive, the antistatic coating being provided on a first side of the substrate and the adhesive being provided on a second side of the substrate opposite the first side, the one or more removable lens layers laminated on the base layer such that the second side of the substrate of each removable lens layer faces the first side of the substrate of an immediately preceding one of the base layer and the one or more removable lens layers; A removable lens stack wherein the refractive index of the substrate of the base layer, the substrate of each removable lens layer, and the adhesive of each removable lens layer are matched to within 0.

2.

2. 10. The removable lens stack of claim 1, wherein each removable lens layer further comprises an adhesion promoting treatment on the second surface of the substrate between the substrate and the adhesive.

3. The removable lens stack of claim 1 , wherein each removable lens layer is corona treated on the second surface of the substrate.

4. The removable lens laminate of claim 1 , wherein the base layer further comprises an adhesive, the adhesive being provided on a second side of the substrate opposite the first side.

5. The removable lens laminate of claim 4 , wherein the base layer further comprises an adhesion promoting treatment on the second surface of the substrate between the substrate and the adhesive.

6. The removable lens laminate of claim 4 , wherein the base layer is corona treated on the second side of the substrate.

7. The removable lens stack of claim 1 , wherein the substrate of each removable lens layer comprises a polyethylene terephthalate (PET) film.

8. The removable lens stack of claim 1 , wherein the substrate of each removable lens layer comprises a thermoplastic polyurethane (TPU) film.

9. The removable lens laminate of claim 1 , wherein the substrate of the base layer comprises a polyethylene terephthalate (PET) film.

10. The removable lens laminate of claim 1 , wherein the substrate of the base layer comprises a thermoplastic polyurethane (TPU) film.

11. A sandblasting helmet, Face shield and one or more removable lens layers laminated on the face shield, each removable lens layer comprising a substrate, an antistatic coating comprising a quaternary ammonium cation, and an adhesive, the antistatic coating being provided on a first side of the substrate and the adhesive being provided on a second side of the substrate opposite the first side, the one or more removable lens layers laminated to the face shield such that the second side of the substrate of a first removable lens layer of the one or more removable lens layers faces the face shield, and the second side of the substrate of each removable lens layer after the first removable lens layer faces the first side of the substrate of a immediately preceding removable lens layer of the one or more removable lens layers; A sandblast helmet, wherein the refractive index of the substrate of each removable lens layer and the refractive index of the adhesive of each removable lens layer match within 0.

2.

12. 12. The sandblasting helmet of claim 11, wherein each removable lens layer further comprises an adhesion promoting treatment on the second surface of the substrate between the substrate and the adhesive.

13. 12. The sandblasting helmet of claim 11, wherein each removable lens layer is corona treated on the second surface of the substrate.

14. 12. The sandblasting helmet of claim 11, wherein the substrate of each removable lens layer comprises a polyethylene terephthalate (PET) film.

15. The sandblasting helmet of claim 11 , wherein the substrate of each removable lens layer comprises a thermoplastic polyurethane (TPU) film.

16. A method for manufacturing a removable lens laminate, comprising: providing an antistatic coating on a first substrate, the antistatic coating comprising a quaternary ammonium cation; providing an adhesive on a second substrate; laminating the second substrate onto the first substrate such that the adhesive provided on the second substrate faces the antistatic coating provided on the first substrate; The method wherein the refractive indices of the first substrate, the second substrate, and the adhesive are matched to within 0.

2.

17. 17. The method of claim 16, further comprising the step of providing an adhesion promoting treatment on the second substrate prior to the adhesive providing step.

18. 17. The method of claim 16, further comprising corona treating the second substrate prior to the adhesive providing step.

19. The method of claim 16 , wherein the second substrate comprises a polyethylene terephthalate (PET) film.

20. The method of claim 16 , wherein the second substrate comprises a thermoplastic polyurethane (TPU) film.

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