MXPA98010148A - Satined and satined iridiscent films satina - Google Patents

Abstract

The present invention relates to this invention provides a resinous film of multiple thermoplastic layers wherein two or more resinous materials form a plurality of very thin layers of a substantially uniform thickness, the adjoining adjacent layers being of different resinous, thermoplastic, transparent materials that they differ in the refractive index, with each of the outer skin layers being at least 5% of the total thickness of the film, and the multilayer film containing a sufficient amount of a pearlescent pigment to make it do not shine

Description

IRIDISCENT FILMS SATIN AND SATIN DYED BACKGROUND OF THE INVENTION Multilayer plastic films, which contain alternating layers of two polymers of different refractive indexes, are iridescent when the individual layers are of adequate thickness. These films are described in Patent Number Re 31,780 to Cooper, Shetty and Pinsky, and in Patent Number 5,089,318, and in Patent Number 5,451,449, both to Shetty and Cooper, which are incorporated herein by reference, and in others. patents The iridescent color is produced by the phenomenon of light interference. The pair of alternating polymer layers constitutes the optical core. Normally, the outermost layers or layers of skin are thicker than the layers in the optical core. This thicker skin may consist of one of the components of the optical core, or may be of a different polymer that is used to impart physical, mechanical or other desired properties to the film. Most iridescent films are transparent and bright, with levels of nebulosity on the scale of 1 to 5 percent. There have been different requests in the past for an iridescent film that is muted or not bright. Different methods have been tried to produce a non-glossy film, but in the past, these have had their drawbacks. Some of the tested methods were: 1. An additive in the skin material that would alter the surface of the film and disperse the light, resulting in a cloudy film. Here the drawback was that when the film was laminated, the roughness of the surface that was laminated was filled with the adhesive, and the nebulosity was reduced by half. The additive had particle sizes equal to, or smaller than, the skin layer (less than or equal to 1 or 2 microns). Attempting to increase the amount of additives resulted in problems in trying to stretch the molten fabric. 2. The addition of a pigment such as Ti02, gave the desired levels of nebulosity, but added a large amount of whiteness to the film, and did not provide the desired appearance. 3. The mixture of two polymers with different refractive indices gave the desired levels of nebulosity. The two polymers, in general, had to be from different families of polymers, due to the requirement that the refractive indexes had to be different. This resulted in mixing and processing problems, and resulted in deterioration of the properties of the film.

In the past, it has been tried to incorporate pearlescent pigments in the skins, but due to the relatively large particle sizes, sufficient pigment could not be made to enter the film to achieve the desired effect without introducing voiding problems in the film.

SUMMARY OF THE INVENTION With the introduction of the finer particle sizes of the pearlescent pigments, it has now been discovered that sufficient pearlescent pigments can be added to achieve cloudiness levels of 10 percent to 80 percent, and possibly more. The pearlescent pigments offer a soft, satiny, pearl-like appearance to the iridescent base colors, which is very pleasing to the eye, without substantially changing the properties of the base film. More specifically, this invention provides a thermoplastic resinous multilayer laminated film of a plurality of very thin layers of substantially uniform thickness, the layers being generally parallel to adjoining adjacent layers that are of different transparent thermoplastic resinous materials, being each of the outermost skin layers at least 5 percent of the total thickness of the film, and the multilayer film containing a sufficient amount of pearlescent pigment to render them non-glossy. The multilayer laminated film preferably has at least 10 of the very thin layers, more preferably at least 35, and most preferably at least 70. Adjacent layers of the laminated film preferably differ in the refractive index by at least about 0.03, and more preferably by at least about 0.06. Preferred transparent thermoplastic resinous materials of the laminated film are ethylene polyterephthalate (PET), polymethyl methacrylate (PMMA), polybutylene terephthalate (PBT), and glycol-modified ethylene poly terephthalate (PETG). The pearlescent pigment may be incorporated in at least one of the outermost layers (skin), or in at least one inner layer of the film. In one embodiment of this invention, a sufficient amount of a transparent, preferably stable, dye is dissolved in at least one of the layers to improve or modify the apparent color of at least one of the reflection and the transmission of the colors of the movie. The dye may be present in each of the different thermoplastic resinous materials, or in less than all of them.

Pearlescent pigments of fine particles can be easily incorporated into many of the resins used to make iridescent films, and accordingly, formulations of laminated film of these resins in the glossy appearance can be conveniently produced.

DETAILED DESCRIPTION OF THE INVENTION The pearlescent pigments used herein consist of mica platelets coated with an oxide, usually titanium dioxide and / or iron oxide. The pigments are transparent and reflect light, due to their smooth surface and high refractive index. Since coatings of a controlled thickness can also produce color by optical interference, certain pearlescent pigments impart color as well as luster. Pearlescent pigments have the following properties: Pearlescent pigments are transparent or translucent, to allow light to pass through them to the optical core of the multilayer film, and to allow iridescent colors to pass through the pigments and are visible, resulting in an iridescent film. 2. Pearlescent pigments disperse enough light from the edges to result in a non-glossy satin film, with high levels of haze. The light is scattered by the pearlescent pigments inside the film, and it is not a superficial phenomenon. Therefore, the level of haze and the satin effect are not reduced if the film is laminated, coated, etc. 3. The particles of pearlescent pigment should be sufficiently small (2 to 15 microns), so that there can be a sufficient amount of pigments added to the polymers, to reach the desired levels of nebulosity (from 10 to 80 percent) , and not find problems in the maintenance of a fabric during the process of making the film. Magnapearl 3100® (mica coated with titanium dioxide) and Micromica Red® (mica coated with titanium dioxide, with a red interference color), are the two preferred pearlescent pigments used to make the satin and satin-dyed iridescent films of this invention . Both have all the above characteristics, and the particle size range of these two pigments is in the range of 2 to 15 microns. The following examples are illustrative: EXAMPLE 1 Ethylene polyterephthalate (PET) thermoplastic polyester was fed to the feed block from an extruder, and methyl polymethyl methacrylate (PMMA) from a second extruder, to form a 115 layer optical core, a second was added. skin layer (approximately 20 percent of the total thickness) of ethylene poly-terephthalate (PETG) modified with glycol to each surface by means of a third extruder, to form an iridescent film of 0.73 mils (18.5 microns) thick. The film was brilliantly iridescent, and red and green prevailed when seen by reflection in a perpendicular incidence, and blue and pink when seen by transmission in a perpendicular incidence. The film had a glossy surface, and had a level of haze of about 3 percent. The above procedure was repeated, with the exception that a white pearlescent pigment was incorporated into the second skin layer of glycol-modified ethylene poly terephthalate, at a concentration level of 5 percent. The pearlescent pigment had a particle size scale of 2 to 15 microns, and was a mica coated with titanium dioxide. The resulting film had the same colors in reflection and transmission as the previous sample, but had a non-glossy satin surface, and had a cloudiness level of approximately 36 percent.

Example 2 A multi-layered structure was prepared with the same polymers in the optical core as in Example 1, with the exception that the optical core had 229 layers, and the two outer skin layers added by means of a third extruder were of ethylene poly terephthalate, which had a white pearlescent pigment incorporated therein, at a concentration level of 5 percent. The pearlescent pigment was a mica coated with titanium dioxide, with a scale of particle sizes of 2 to 15 microns. The resulting film was 1.30 mils (33 microns) thick, and had more intense iridescent colors than the film of Example 1, due to the greater number of layers in the optical core. The addition of the pearlescent pigment resulted in a film having a non-glossy satin surface, and having a cloudiness level of approximately 43 percent. In Examples 3 to 7 they are presented in tabular form immediately: EXAMPLE 8 Example 7 was repeated, where the thicknesses of the outer skin layers of PETG were doubled in a film with a cloudiness level of 31 percent.

Example 9 Example 1 was repeated with a red pyridone dye incorporated in the PMMA polymer of lowest index in a concentration of 0.07 percent. This resulted in a film similar to the iridescent film colored with a red tint, but with a non-glossy satin surface, and a cloudiness level of about 36 percent.

EXAMPLE 10 Example 1 was repeated with a blue anthraquinone dye incorporated in the lower index PMMA polymer, at a concentration of 0.4 percent. This resulted in a film similar to the iridescent film colored with a blue tint, but with a non-glossy satin surface, and a nebulosity level of about 36 percent.

Example 11 Example 1 was repeated with a combination of a green anthraquinone dye and a yellow pyrazolone dye incorporated in the lower index PMMA polymer at a concentration of 0.15 percent. This resulted in a film similar to the iridescent film colored with a green tint, but with a non-glossy satin surface, and a cloudiness level of about 36 percent. Example 12 Example 1 was repeated with a yellow pyrazolone dye incorporated in the PMMA polymer of lowest index in a concentration of 0.15 percent. This resulted in a film similar to the iridescent film colored with a yellow tint, but with a non-glossy satin surface, and a nebulosity level of about 36 percent. Different changes and modifications can be made in the present invention without departing from the spirit and scope thereof. The above examples show films made with combinations of PBT, PET, PETG and PMMA. The pearlescent pigments can be incorporated into any thermoplastic resinous material that can be used as the outer skin materials to make an iridescent film. Pearlescent pigments can also be incorporated into more than one component of the iridescent film, provided that the iridescent color obtained from the optical core is not destroyed or darkened. It will be appreciated that, although the invention has been described with reference to the type of film emptied from film production, iridescent films can also be made by the tubular process (blown film). In accordance with the foregoing, the various embodiments disclosed herein were for the purpose of illustration only, and not to limit the invention. The present invention should be limited not by specific disclosure of the present, but only by the appended claims.

Claims (14)

NOVELTY OF THE INVENTION Having described the foregoing invention, it is considered as a novelty and, therefore, the content of the following is claimed as property: CLAIMS

1. A resinous film coextruded in multiple thermoplastic layers, comprising a plurality of very thin coextruded layers of transparent thermoplastic resinous materials, these layers being substantially parallel, the adjacent layers being different transparent thermoplastic resinous materials of different refractive index, each layer constituting more externally a skin, this skin constituting at least 5 percent of the total thickness of the film, the multilayer film containing a sufficient amount of a pearlescent pigment to render it non-glossy.

2. The resinous multilayer thermoplastic film according to claim 1, characterized in that it has at least 10 of these very thin layers.

3. The resinous multilayer thermoplastic film according to claim 1, characterized in that it has at least 35 of these very thin layers.

4. The resinous multilayer thermoplastic film according to claim 1, characterized in that it has at least 70 of these very thin layers.

5. The resinous multilayer thermoplastic film according to claim 1, characterized in that the contiguous adjacent layers differ in the refractive index by at least about 0.03.

6. The resinous multilayer thermoplastic film according to claim 1, characterized in that the adjoining adjacent layers differ in the refractive index by at least about 0.06.

7. The thermosetting multilayer resinous film according to claim 1, characterized in that the thermoplastic resinous materials are selected from the group consisting of ethylene poly-terephthalate, butylene poly terephthalate, poly-terephthalate ethylene modified with glycol, and poly-methyl methacrylate.

8. The thermoplastic multilayer resinous laminated film according to claim 1, characterized in that one of the thermoplastic resinous materials is ethylene poly-terephthalate.

9. The resinous multilayer thermoplastic film according to claim 1, characterized in that one of the thermoplastic resinous materials is methyl polyethacrylate.

10. The thermoplastic multilayer film according to claim 1, characterized in that it also contains a sufficient amount of a transparent dye dissolved in at least one of the layers, to improve or modify the apparent color of at least one of the reflection and transmission colors of the film. The resinous multilayer thermoplastic film according to claim 10, characterized in that the dye is present in each of the different thermoplastic resinous materials. 12. The thermoplastic resinous multilayer film according to claim 10, characterized in that the dye is present in less than all the different transparent thermoplastic resinous materials. 13. The resinous multilayer thermoplastic film according to claim 1, characterized in that the pearlescent pigment is incorporated in at least one of the skin layers. 14. The resinous thermoplastic multilayer film according to claim 1, characterized in that the pearlescent pigment is incorporated in at least one of the internal layers.