TWI584961B - Retroreflective composite film ready for yarn-slitting - Google Patents

Description

Reversion reflective composite film that can be directly used for yarn division

The present invention relates to a retroreflective composite film, and more particularly to a retroreflective composite film that can be used directly for yarn-slitting.

A retroreflective material is characterized by being capable of redirecting light incident on the material to reflect it back to the original source. This performance has made complex reflective materials widely used in a variety of transportation and personal safety applications. Reversion reflective materials are commonly used in a variety of articles such as traffic signs, roadblocks, license plates, pavement markings and signage, as well as reflective strips for vehicles and clothing.

Articles that can be prepared to have reversion reflective properties include fibers, fabrics, materials, and garments made therefrom. It is also possible to impart reversion reflective properties to attachments and security articles. A garment having a reflexive reflective property can include a film-like coating that includes a retroreflective element embedded in the adhesive to enhance the visibility of the garment and the person wearing the garment, particularly at night. With enhanced visibility, garments with complex reflective properties provide greater security in areas such as areas with large traffic flows. Construction workers, road maintenance personnel, pedestrians, joggers and cyclists can all benefit from providing this improved safety. The attachment may also have a reflex reflection property.

The return may be commercially available reflective material film, for example ^(TM) Scotchlite ^(TM) Reflective material 3M, which can be composite to the substrate, and further divided into a desired yarn of the textile article. The reflective material having an adhesive is firmly laminated to the support film via a roller, and the resulting laminated film is divided or cut into strands or fibers having a certain width, as disclosed in U.S. Patent No. 4,336,092. And finally wrap it onto the bobbin. The yarn produced in this manner can then be used for subsequent processing, such as making a fabric having retroreflective properties.

The present invention provides a reconstituted reflective composite film comprising a base film and a retroreflective film, wherein a reactive solventless adhesive layer is present between the base film and the retroreflective film. Therefore, the reconstituted reflective composite film of the present invention can be directly used for the yarn division and has better heat resistance. In addition, because of the different composite methods used, the resulting reconstituted reflective composite film can have a thinner thickness and can provide a wider range of applications.

The invention also provides a method of manufacturing the reconstituted reflective composite film comprising the steps of: (a) providing a base film and a reversal reflective film; (b) coating a reactive solventless adhesive layer on the base film or recursive reflection (c) laminating the retroreflective film onto the base film.

The invention also relates to the use of the complex reflection composite film, which can be used for manufacturing reflective yarns, and further into fabrics, clothes and the like. The mechanical strength (e.g., tensile strength, elongation at break, etc.) of the resulting retroreflective yarn is comparable to that of the prior art.

The inventors have surprisingly found that the reconstituted reflective composite film provided by the present invention can also overcome the problems associated with yarns prepared from conventional retroreflective material films. In particular, yarns made with conventional retroreflective material films are less heat resistant because the films of the retroreflective materials comprise a hot melt adhesive. Although the film of the composite reflective material can be bonded to the support film by heat, the problem of residual hot-melt adhesive on the machine parts is caused by reheating in subsequent processes such as textile or heat treatment of the final product.

In addition, during storage and storage, due to the humidity and temperature of the environment, the adhesive exposed to the side due to the yarn-slitting procedure may also degumming, resulting in adhesion between the yarns during use. Need additional stress to separate the yarn and thus easy fracture. In order to avoid this problem, it is necessary to rewind the entangled yarn, resulting in an increase in time and money costs, and a problem that may cause the yarn to be turned over.

Therefore, the reconstituted reflective composite film provided by the present invention is more suitable for yarn division and subsequent processing (for example, textile), and at least partially solves and avoids the above disadvantages.

Based on the enumerated uses and the description in the present specification, those skilled in the art can envision various other uses of the reconstituted reflective composite film of the present invention.

Other aspects and specific embodiments are also contemplated by the present invention. The above summary of the invention and the following embodiments are not intended to limit the invention to any particular embodiments.

1‧‧‧Return-reflective composite membrane

2‧‧‧ basement membrane

3‧‧‧Reactive solvent-free adhesive layer

4‧‧‧Returned reflective film

5‧‧‧Layer of elastic material

6‧‧‧Returning reflective structural layer

D‧‧‧thickness

Figure 1 shows a specific embodiment of the reconstituted composite film of the present invention.

Reversion reflective composite film

The complex reflection composite film of the present invention comprises a base film and a retroreflective film, wherein a reactive solventless adhesive layer is provided between the base film and the retroreflective film. In one embodiment of the invention, the thickness of the retroreflective composite film of the present invention is less than or equal to about 0.255 mm, preferably from about 0.220 mm to about 0.255 mm. Conventional composite film thicknesses are typically at least about 0.260 mm to about 0.295 mm, or even thicker. In another embodiment of the invention, both sides of the base film may each have a layer of retroreflective film.

Basement membrane

The material of the base film may be any material suitable for supporting the retroreflective film, such as a film comprising one or more thermoplastic polymers, such as polyester or polycarbonate. In one embodiment of the present invention, the base film of the present invention may be a polyethylene terephthalate (PET) film or a polyethylene naphthalate (PEN) film. In one embodiment of the invention, the base film of the present invention has a thickness of at least about 0.025 mm, preferably from about 0.025 to about 0.060 mm, most preferably about 0.050. Mm.

Reversion film

In an embodiment of the invention, the retroreflective film of the present invention comprises an elastic material layer and a reversal reflective structure layer. In another embodiment of the invention, the retroreflective film of the present invention has a thickness of at least about 0.080 mm, preferably from about 0.080 mm to about 0.105 mm.

The layer of elastomeric material can be any material suitable for carrying a layer of revertive reflective structures, such as rubber or resin. In one embodiment of the invention, the elastomeric layer of the invention comprises an elastomeric rubber or a polyurethane (PU) resin. In another embodiment of the present invention, the elastic material layer may further contain a metal or mineral (powder or flake) material to increase its thermal stability to lower the viscosity at high temperatures.

The structure of the reversing reflective structure layer provides reversion reflective properties such as a bead layer and a solid angle (prism) layer. In one embodiment of the invention, the reconstituted reflective structural layer of the present invention comprises a layer of microbeads which may be made of glass, a non-glass ceramic composition or a synthetic resin. In another embodiment of the invention, the reversing reflective structural layer comprises glass beads.

In one embodiment of the invention, the microbeads generally have an average diameter of from about 10 [mu]m to about 200 [mu]m, preferably from about 25 [mu]m to about 80 [mu]m. In one embodiment of the invention, the refractive index of the microbeads can be adjusted as desired, typically between about 1.5 and about 2.5, preferably about 1.91.

The reset reflective structure layer used in embodiments of the present invention may have a specularly reflective portion underneath it to form a plurality of retroreflective elements. In an embodiment of the invention, the specularly reflective portion is a thin layer of reflective metal or a thin layer of a metal compound. In one embodiment of the invention, the specularly reflective portion is preferably located on the embedded or back side portion of the return-reflective structural layer. The term "specular reflection portion" means a portion containing an elemental metal or a compound thereof (e.g., an oxide, a sulfide, and a hydroxide) that reflects light, preferably specularly reflects light. The metal can be formed into a continuous plating by vacuum deposition, evaporation, chemical deposition or electroless plating, and a specular reflection portion can be obtained using various metals. These metals include aluminum, silver, tin, titanium, chromium, nickel, magnesium, indium, copper or gold in elemental form; or compound forms such as sulfur Zinc or titanium dioxide. In one embodiment of the invention, aluminum and silver are preferred metals for the specularly reflective layer because they provide good refraction brightness. In an embodiment of the present invention, the elemental metal or a compound thereof may be coated on one side of the revertive reflective structure layer; in another embodiment of the present invention, the elemental metal or a compound thereof is coated on the microbead One side of the layer.

The retroreflective film of the present invention is substantially free of an adhesive.

Reactive solventless adhesive

A suitable reactive solventless adhesive in the present invention refers to an adhesive which does not require a solvent when applied, and the method for producing a composite film of the present invention is environmentally friendly because no solvent is required.

The reactive solventless adhesives of the present invention include, but are not limited to, reactive hot melt adhesives, two component adhesives, and heat curable adhesives. In one embodiment of the invention, the reactive hot melt adhesive may be a polyurethane (PUR) system, which typically contains an isocyanate (eg, methyl bis(phenyl isocyanate)); crystalline, amorphous, and/or Or a liquid polyol; a curing catalyst; and a non-reactive additive. Reactive hot melt adhesives have reactive groups that are sensitive to environmental factors such as heat, moisture, light and/or pressure. The initial solidification strength (green strength) was good after application, and the degree of curing and adhesion were enhanced when subjected to environmental factors. The reactive hot melt adhesive is a fluid having high viscosity after being heated to a temperature (for example, about 110 to 133 ° C), and is triggered by cooling of the non-reactive additive and the prepolymer at room temperature after application. The action produces an initial solidification strength, and its final strength is achieved by chemical secondary crosslinking, such as heat, moisture or both, and solidification into a non-thermoplastic adhesive layer.

Unlike conventional hot melt adhesives, after the reactive hot melt adhesive is thermally melted and applied, an initial solidification strength is produced at room temperature, and subsequent heat or moisture does not cause the reactive heat. The molten adhesive melts again, which in turn causes it to further produce chemical secondary cross-linking, which enhances the adhesive strength of the adhesive and its mechanical strength.

In an embodiment of the present invention, the two component adhesive of the present invention comprises, but is not limited to In the epoxy resin adhesive commonly known as AB glue, after mixing the two liquid components A and B, the two agents cross-link and react to form a high-strength structural layer.

In one embodiment of the present invention, the reactive solvent-free adhesive is a one-liquid type heat-curing epoxy resin, and the liquid adhesive is heated to a certain temperature to rapidly generate a crosslinking reaction to be cured.

Figure 1 is a specific embodiment of the present invention. The composite reflection composite film (1) comprises an intermediate layer (2) as a base film, an outer layer (4) as a reversal reflection film, and a reactive solventless adhesive between the base film (2) and the reversion reflection film (4) (3) Bonding, wherein the retroreflective film (4) may further comprise an elastic material layer (5) and a bead layer (6) (ie, a reversing reflective structure layer). The composite reflective film (1) has an overall thickness (d shown in FIG. 1) of about 0.225 mm to about 0.255 mm, a base film (2) thickness of about 0.050 mm, and a return reflection film (4) thickness of about 0.080 mm. Up to about 0.100mm.

Production method

The present invention provides a method of fabricating a reconstituted reflective composite film comprising the steps of: (a) providing a base film and a retroreflective film; (b) coating a reactive solventless adhesive layer on the base film or the retroreflective film (c) laminating the retroreflective film onto the base film.

In one embodiment of the invention, the method of applying the reactive solventless adhesive in step (b) is preferably screen printing, gravure printing or letterpress printing. In another embodiment of the present invention, the method of applying the reactive solventless adhesive is more preferably a gravure or relief printing method in a full-size manner. In the present invention, the amount of the reactive solvent-free adhesive applied is sufficient to bond the base film and the retroreflective film, and to reduce the thickness as much as possible. In one embodiment of the invention, the reactive solventless adhesive layer of the retroreflective composite film produced after lamination in step (c) has substantially no measurable thickness.

use

The complex reflection composite film of the present invention can be directly divided into yarns, for example, by conventional means. The yarn machine divides or cuts it into strands or fibers and then wraps it onto the spool. The resulting textured yarn has a tensile strength of at least about 0.20 kg/f, preferably at least about 0.25 kg/f; and an elongation at break of at least about 30%. In one embodiment of the invention, the retroreflective yarn of the present invention may have a width of about 0.368 mm or less, or any width suitable for subsequent applications.

The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

Example 1

A PET film is provided as a base film on which a reactive non-solvent type adhesive of the present invention, such as a moisture-curable polyurethane adhesive, is applied by gravure printing. Comprising an elastic material layer and a reset return of the reflection film layer structure, e.g. film 3M ^TM Scotchlite ^TM C420 production of 3M were laminated to both sides of the base film, the return of the present invention to obtain a reflective composite film. The composite film was divided into yarns having a width of about 0.368 mm, and the thickness of the obtained reflective yarn was tested to be about 0.220 mm to about 0.230 mm according to the ASTM D1777 standard.

Example 2

After the reflective yarn obtained in Example 1 was subjected to accelerated aging conditions (e.g., 37 ° C, 90% relative humidity, 8 hours), it was tested to have a thickness of about 0.220 mm to about 0.230 mm according to the ASTM D1777 standard.

Example 3

The tensile strength and elongation at break of the reflective yarns of Examples 1 and 2 were measured, and the measurement standards and results are shown in Table 1 below.

As can be seen from the data, the reconstituted reflective composite film of the present invention (Example 1) was significantly reduced by about 15.4% compared to the conventional film thickness. Since the thickness of the reconstitution reflection composite film of the present invention is lowered, the reversal reflection composite film of the present invention can be made into a reflective yarn having a narrower width, thereby making the application layer wider.

In addition, the retroreflective composite film of the present invention has a thickness of about 16.4%, which is greatly reduced in softness compared to the conventional laminated film, by the retroreflective yarn obtained by direct yarn splitting (Example 1). Lifting without compromising the mechanical strength of the reflective yarn (eg tensile strength) Degree and elongation at break).

The reflective yarn of the present invention (Example 2) subjected to accelerated aging conditions also has a thickness of about 0.220 mm to about 0.230 mm, and its mechanical strength is also similar to that of the reflective yarn before the aging (Example 1), showing the reversal reflection composite of the present invention. The mechanical strength of the reflective yarn produced by the film under normal storage conditions is still unaffected (as shown in Table 1).

1‧‧‧Return-reflective composite membrane

2‧‧‧ basement membrane

3‧‧‧Reactive solvent-free adhesive layer

4‧‧‧Returned reflective film

5‧‧‧Layer of elastic material

6‧‧‧Returning reflective structural layer

D‧‧‧thickness

Claims (19)

A complex reflective composite film comprising a base film and a retroreflective film, wherein a reactive solventless adhesive layer is present between the base film and the retroreflective film. The reconstituted reflective composite film of claim 1, wherein each of the two sides of the base film has a layer of the retroreflective film. The reconstituted reflective composite film of claim 1, wherein the reactive solvent-free adhesive layer comprises a reactive hot melt adhesive, a two-component adhesive, or a thermosetting adhesive. The reconstituted reflective composite film of claim 3, wherein the reactive hot melt adhesive is a moisture curable polyester (PUR) adhesive. The reconstituted reflective composite film of claim 1, wherein the base film comprises a polyethylene terephthalate film or a polyethylene 2,6 naphthalate film. The composite reflective film of claim 1, wherein the retroreflective film comprises an elastic material layer and a reversal reflective structure layer, wherein the reactive solventless adhesive layer is interposed between the elastic material layer and the base film. The reconstituted reflective composite film of claim 6, wherein the elastic material layer comprises an elastic rubber or a polyurethane (PU) resin. The reconstituted reflective composite film of claim 6, wherein the retroreflective structural layer comprises glass beads. The reconstituted reflective composite film of claim 6, wherein one side of the retroreflective structural layer has a thin layer of reflective metal or a thin layer of a metal compound. The reconstituted reflective composite film of claim 9, wherein the reflective metal thin layer or metal compound thin layer comprises aluminum, silver, tin, titanium, chromium, indium, copper, gold, zinc sulfide or titanium dioxide. The reconstituted reflective composite film of any one of claims 1 to 10, wherein the base film has a thickness of from about 0.025 to about 0.060 mm, and the retroreflective film has a thickness of at least about 0.080 Mm. The reconstituted reflective composite film of any one of claims 1 to 10, which has a thickness of less than or equal to about 0.255 mm. The reconstituted reflective composite film of any one of claims 1 to 10, wherein the retroreflective film is substantially free of an adhesive. A use of a reconstituted reflective composite film according to any one of claims 1 to 13 for the manufacture of a reflective yarn. A retroreflective yarn produced by the recursive composite film of any one of claims 1 to 13 having a width of about 0.368 mm or less. The reflective yarn of claim 15 having a tensile strength of at least about 0.20 kg/f. The reflective yarn of claim 15 or 16 having an elongation at break of at least about 30%. A method of manufacturing a complex reflection composite film comprising the steps of: (a) providing a base film and a reversal reflection film; (b) coating a reactive solvent-free adhesive layer on the base film or the reversal reflection film; The composite retroreflective film is laminated to the base film. The method of claim 18, wherein the step (b) is using a screen, letterpress or gravure printing method.