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Retroreflective sheeting comprising a substantially amorphous polymer layer

A polymer layer, amorphous technology, applied in the direction of synthetic resin layered products, layered products, instruments, etc., can solve the problems of adverse effects of retroreflective efficiency, retroreflective efficiency, etc.

Active Publication Date: 2019-05-07
3M INNOVATIVE PROPERTIES CO
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

A disadvantage of this manufacturing method is that the resulting sheet has cube corner elements that exhibit a relatively high level of shrinkage when hardened or cured, creating optical defects in the cube corner microstructure, i.e., the faces intervening the cube corners. Angle change between that produces light scatter rather than the desired maximum retroreflectivity
If the angles between the faces of the replicated cube-corner elements cannot be controlled and maintained (for example, because of shrinkage effects, deformation upon removal from the mold, or deformation due to thermal or mechanical stress), retroreflective efficiency will suffer significantly influences
Even a slight lack of control and maintenance of cube corner geometry can have a significant detrimental effect on the resulting retroreflective efficiency

Method used

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  • Retroreflective sheeting comprising a substantially amorphous polymer layer
  • Retroreflective sheeting comprising a substantially amorphous polymer layer
  • Retroreflective sheeting comprising a substantially amorphous polymer layer

Examples

Experimental program
Comparison scheme
Effect test

example

[0056] Material

[0057] The following materials were used in the preparation of Comparative Examples A-B and Examples 1-8.

[0058]

[0059] Test Methods

[0060] back Reflectance coefficient (brightness) (R A ) : generally by the method described in ASTM E810-03, "Standard Test Method for Coefficient of Retroreflection of Retroreflective Sheeting Utilizing the Coplanar Geometry (the standard test method for the coefficient of retroreflective sheeting using coplanar geometry)", using retroreflective Luminance was measured with a meter (Retrosign GR3, commercially available from DELTA Danish Electronics). Take cd / lux.m 2 Report results for units.

example 1

[0067] A retroreflective article was made as described in Comparative Example A, except that a substantially amorphous polymer layer was disposed between the body layer and the cube corner elements. Additionally, a substantially amorphous polymer layer is disposed on the opposite side of the body layer. The PET body layer was coextruded with two amorphous "PETG 14285" polymer layers on each side of the PET body layer. The multilayer article is biaxially stretched (tentering), which crystallizes the PET film, and then subjected to annealing at a temperature of about 230-260°C (445-500°F). The thickness of the PET bulk layer was 234 μm, and each PETG layer had a thickness of about 10 μm.

[0068] Cube corner elements were cast on the amorphous polymer layer using the stereo resin composition and procedure of Comparative Example A.

example 2

[0070] Retroreflective articles were made as described in Example 1, except that the bulk layer comprised a PET film available under the trade designation "NanYa 1N404," which had a thickness of about 71.2 μm, and each amorphous polymer layer had a thickness of is 1.9 μm.

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Abstract

This application relates generally to retroreflective articles and methods of making retroreflective articles. The retroreflective article includes a substantially amorphous polymer layer interposed between the body layer and the discrete truncated cube corner elements. The substantially amorphous polymer layer absorbs, dissipates, and / or accommodates at least some of the stress placed on the retroreflective article during handling. Discrete truncated cube corner elements with increased fidelity can thereby be formed. Accordingly, a retroreflective sheeting that includes a substantially amorphous polymer layer has increased brightness compared to a composite sheet that is similarly prepared and does not contain the substantially amorphous polymer layer.

Description

technical field [0001] This application relates generally to retroreflective articles and methods of making retroreflective articles. Background technique [0002] Retroreflective articles are characterized by the ability to redirect light incident on the material so that it reflects back to the original light source. This characteristic has led to the widespread use of retroreflective articles in sheet form, for example, in traffic signs and personal safety articles. Retroreflective sheeting is commonly used in a variety of traffic control articles (eg, road markings, barricades, license plates, pavement markings and pavement marking tapes, and reflective tapes for vehicles and clothing). [0003] Cube corner sheeting (sometimes called prisms, microprisms, corner prisms, or total internal reflection sheeting) is a type of retroreflective sheeting. Such retroreflective sheeting typically includes a plurality of cube corner elements that retroreflect incident light. Retror...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B32B3/26
CPCB32B7/12B32B27/08B32B27/32B32B27/322B32B27/34B32B3/30B32B2250/02B32B2250/24B32B2307/416B32B2307/51B32B2307/518B32B2307/702B32B27/36B32B27/365B32B3/10B32B3/14B32B3/18B32B2307/704B32B2551/00B32B2590/00G02B5/124B29D11/00605B29K2067/003B29K2995/003
Inventor 雷马·查特吉斯蒂芬·A·约翰逊罗伯特·F·瓦特金斯比马尔·V·塔卡尔
Owner 3M INNOVATIVE PROPERTIES CO