MXPA97009215A - Packaging structure of a base supply that includes a coloidal copolymer for greater sustainability - Google Patents

Abstract

The present invention relates to the use of a single "hold" coating layer that includes a colloidal copolymer applied by the paper machine on the barrier side applied by press of a cardboard substrate. Structures of this type generally allow paper machines to have only one coater on the barrier side, to apply a sufficient coating for the support desired.

Description

PACKAGING STRUCTURE OF A BASE SUPPLY INCLUDING A COLOIDAL COPOLYMER FOR GREATER SUSTAINABILITY 5 BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the use of a single layer of M? "hold" coating applied by the machine paper on the barrier side applied by press of a cardboard substrate. Structures of this type in general allow paper machines to have only one coater on the barrier side, to apply a coating sufficient for the desired support. 2. Description of the Related Art In the production of cardboard boxes, it is known to produce a box with a coating applied by press on the side not coated with clay. Due to the lack of support, severe stings of the coating applied with press. On the side coated with clay, a film applied with a press almost free of pitting can be achieved. However, during bending and marking operations, pitting may occur at the corners and joints, and may result in the food product attacks the cardboard layer, resulting in a catastrophic failure. Also, if a clay-coated surface is required under the press applied film, it may require external printing on one side not coated with clay, if C1S paperboard is used (coated on one side). This can dramatically reduce the print quality of the package. Consequently, a more convenient coating would be presented then if the sustenance could be improved. In the papermaking industry, it is also known to make use of a colloidal copolymer, such as a styrene-butadiene resin (REB). The styrene-butadiene resin is specifically used as a coating binder in papermaking. The advantages of styrene-butadiene resin are better gloss, inking, resistance to moisture, and a more relaxed and flexible coating. Examples of this prior art are U.S. Patent Number 2,537,114 ('114) to A.E. Young et al., Entitled "Pigment Coated Paper", and the United States Patent Number 2,685,571 ('571) to J.C. Stinchfield, entitled "Mineral-Coated Paper and Composition Therefor". Although Patents '114 and' 571 employ a styrene-butadiene resin, the styrene-butadiene resin is not used to increase the desired support. Consequently, an even more convenient coating would then be present if the styrene-butadiene resin could be used in order to increase the support. From the foregoing, it can be seen that there is a need in the art for a polymeric layer applied with a press that can be applied to boxes and carton packs, but that at the same time can be used to improve the barrier support applied with cardboard press. It is a purpose of this invention to satisfy this and other J needs of the technique, in a more apparent way for the expert once given the following description. SUMMARY OF THE INVENTION Broadly speaking, this invention meets these needs by providing a substrate for carton packaging, which comprises a first layer of particulate minerals, a layer of cardboard located inside. of the first layer of particulate minerals, and a second layer of particulate minerals that includes a colloidal copolymer to improve the support located inside the cardboard layer, and a barrier layer located inside the second layer of minerals in particles. In certain preferred embodiments, the colloidal copolymer is styrene-butadiene resin (REB). Also, the barrier layer is a barrier layer applied with a press. In another additional preferred embodiment, the use of the colloidal copolymer in the second layer of minerals in particles, improves the barrier holding properties applied with the substrate press, and consequently, can prevent catastrophic failure in the subsequently produced cardboard containers. The preferred substrate, according to this invention, offers the following advantages: ease of assembly; excellent stability; excellent durability; good economy and excellent sustaining characteristics. In fact, in many of the preferred embodiments, these factors of ease of assembly, stability, durability and sustainability are optimized to the extent that they are considerably higher than what has been achieved hitherto in the above known substrates. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other characteristics of the present invention, which will become clearer as the description proceeds, are better understood by considering the following detailed description in conjunction with the accompanying drawing, in which: the single figure 1 is a vertical cross-sectional view of a coated two-sided substrate for press applied barriers, in accordance with the present invention. DETAILED DESCRIPTION OF THE INVENTION With reference to Figure 1, a coated two-sided substrate 2 is illustrated. The substrate 2 includes, in part, the outer particulate coating 4, the cardboard layer 6, the internal particulate coating 8 which includes a colloidal copolymer, and a conventional barrier coating 10. The coating 4 is preferably constructed of clay or calcium carbonate, and is achieved through a conventional coating of one or more layers of particulate minerals on the layer of cardboard 6. The cardboard layer 6 is typically constructed of a sheet of 0.457 g ^. millimeters (0.018 inches) thick solid bleached sulphate (SBS), unbleached solid sulphate sheet (SNS), or newspaper backed with clay (RPRA). The term "cardboard" describes paper within the thickness scale of 0.178 to 0.711 millimeters (0.007 to 0.028 inches). The invention is relevant for the entire scope of this range, as it applies to packaging and so on. During the construction of the substrate 2, the cardboard layer 6 is suitably coated with one or more layers of particulate minerals to form the outer layer 4. On the other side of the cardboard layer 6, the inner coating 8 is formed. by adjusting the formulation of coating to contain a desired percentage of film-forming binder, in order to improve the holding qualities. Styrene-butadiene resin (REB) can be used at a level of up to 100 percent of the total binder, and in coatings weights of 2.27 to 4.08 kilograms (5 to 9 pounds) per ream. Different levels of styrene-butadiene resin, different coating weights, and the use of other film-forming binders (polyvinyl alcohol) can also be used. This should improve the holding qualities of the coating layer 8, such that a layer for a press applied barrier is typically sufficient. This also allows the paper machines to have only one coater on the barrier side, to apply a coating sufficient for the desired hold. After the coating 8 is applied, the conventional barrier coating 10 is press applied according to conventional techniques. The following examples are provided to further illustrate the present invention, and should not be construed to limit the invention in any way. Example 1 1. Caliber of the cardboard layer (thickness): 0.457 mm (0.018 inches) 2. Weights of the first coating layer of particulate minerals: First coater: 1.59 kg (3.5 lbs) / ream 12% binder (all polyvinyl acetate (PVAC)) Second coater: 2.95 kg (6.5 lbs) / ream Binder 12% (all polyvinyl acetate). 3. Weight of the second mineral layer 5 particles with colloidal copolymer coating (barrier side applied with press): 3.40 kg (7.5 lbs) / ream • 12% binder, 50% of which is 10 styrene resin -butadiene, and 50% PVAC. 4. Barrier layer: 1.36 kg (3.0 lbs) / ream Example 2 15 1. Caliber of the cardboard layer (thickness): 0.356 mm (0.014 inches) • 2. Weights of the first layer of mineral particulate coating: First coater: 1.59 kg (3.5 lbs) / ream 12% binder (all polyvinyl acetate (PVAC)) Second coater: 2.95 kg (6.5 lbs) / ream 25 12% binder (all polyvinyl acetate). 3. Weight of the second layer of particulate minerals with colloidal copolymer coating (applied barrier side 5 with press): 3.40 kg (7.5 lbs) / ream 12% binder, 50% of which is J || styrene-butadiene resin, and 50% PVAC. 10 4. Barrier layer: 1.36 kg (3.0 lbs) / ream. Once given the above description, the expert can think of many other features, modifications or improvements. Therefore, it is considered that these features, modifications or improvements are part of this invention, the scope of which should be determined by the following claims.

Claims (5)

1. LTY OF THE INVENTION Having described the foregoing invention, it is considered as a lty and, therefore, property is claimed as contained in the following: 5 CLAIMS 1. A composite structure for cardboard packaging, to increase the support, in where is it The structure is: a first layer of particulate minerals; a cardboard layer located inside the first layer of 10 minerals in particles; a second layer of particulate minerals including a binder comprised of polyvinyl acetate and a colloidal copolymer to increase the support located within the cardboard layer, wherein the colloidal copolymer is further comprised of resin 15 of styrene-butadiene, and the colloidal copolymer is added to the second layer of particulate minerals at a level of up to 100 percent of a total binder, this binder including up to 50 percent by weight of the colloidal copolymer; and the second layer is applied with a weight of 20 coating from 2.27 to 4.08 kilograms (5 to 9 pounds) per ream; and a press applied barrier layer located within the second layer of particulate minerals.
2. 2. The structure according to claim 1, characterized in that the first layer 25 of particulate minerals is included in addition to: clay.
3. 3. The structure according to claim 1, characterized in that the first layer of particulate minerals is also comprised of: calcium carbonate.
4. 4. The structure according to claim 1, characterized in that the second layer of particulate minerals is also comprised of: clay.
5. 5. The structure according to claim 1, characterized in that the second layer of particulate minerals is also comprised of: calcium carbonate.