Stock material or miscellaneous articles – Web or sheet containing structurally defined element or... – Adhesive outermost layer
Patent
1998-02-12
2000-01-04
Zirker, Daniel
Stock material or miscellaneous articles
Web or sheet containing structurally defined element or...
Adhesive outermost layer
428354, 428516, B32B 712
Patent
active
060107839
DESCRIPTION:
BRIEF SUMMARY
This invention relates to polymer resin blends generally, and more specifically but without limitation to resin blends useful for making film capable of being made into labels (that is, label filmstock) such as deformable, pressure-sensitive labels. This invention also relates to labels generally, and more specifically but without limitation to deformable, pressure-sensitive labels and to label filmstock for making such labels.
It is well known in the art to use thermoplastic label filmstock for making labels that are preferable in many respects to paper labels. Deformable thermoplastic labels desirably are resistant to moisture, tearing, cracking, creasing, wrinkling, shrinking, etc. These properties are especially important when the labels are applied to squeezable or otherwise deformable substrates.
For making labels, label filmstock is generally used in conjunction with an adhesive layer for adhering the label filmstock to a selected substrate. The adhesive is generally selected so that when the label filmstock is adhered to the substrate, the strength of the label filmstock-adhesive interface, the strength of the substrate-adhesive interface, and the cohesive strength of the adhesive itself are all greater than the forces required for deformation and recovery of the label filmstock. The adhesive should be sufficient to enable the label to accomplish its intended purpose for the reasonable lifetime of a deformable container. Pressures sensitive adhesives are preferable and include the acrylic and styrene-butadiene adhesives.
For making labels, label filmstock is also generally used in conjunction with a release liner. The release liner is releasably bonded to the adhesive until the label filmstock/adhesive is suitably peeled away from or dispensed from the liner and adhered to a flexible or deformable substrate. The release liner may be any suitable conventionally known liner material for labeling applications.
In order to be successfully used as label filmstock for deformable, pressure-sensitive labels, a film should also meet three additional general requirements: good optics, die-cuttability, and appropriate stiffness. Whether a label filmstock has good optics is application dependent. In some cases, a low haze high gloss film is required. In other cases, a higher haze, lower gloss film is required. For example, blow molded high density polyethylene bottles may have a 60 degree gloss from 19-36 percent, as measured by ASTM D 2457, while some polypropylene blow molded bottles may have a 60 degree gloss up to 80 percent.
In terms of die-cuttability, a film/adhesive/release liner composite desirably should be die-cuttable on a rotary die at commercial manufacturing speeds without web breaks or damage to the liner. When a film is not very die-cuttable, then more sophisticated and expensive release liners must be used.
In terms of stiffness, a label filmstock must be sufficiently stiff to dispense easily from a release liner, but not too stiff that it wrinkles or deforms when applied to a deformable container.
Polystyrene-based label filmstocks are generally sufficiently die-cuttable and stiff. The stiffness of these polystyrene-based label filmstocks allows for good machine processability in label application equipment, but limits their utility on deformable substrates because labels made from these polystyrene-based label filmstocks wrinkle when applied to a deformable substrate.
U.S. Pat. No. 5,151,309 issued to Dollinger ("Dollinger") discloses a label filmstock comprising a polystyrene blend. The label filmstock of Dollinger is die-cuttable and has good stiffness. However, the label filmstock of Dollinger has very high haze due to the polystyrene blend component. This high haze precludes the use of Dollinger label filmstock in clear labels.
Polyethylene label filmstocks, such as disclosed in Re. 32,929 issued to Ewing ("Ewing"), can be formulated to meet a range of optical and stiffness requirements, but are difficult to die-cut and to dispense from a release liner in labeling equipment because of t
REFERENCES:
patent: Re32929 (1989-05-01), Ewing
patent: 4713273 (1987-12-01), Freedman
patent: 4888075 (1989-12-01), Freedman
patent: 4946532 (1990-08-01), Freeman
patent: 5151309 (1992-09-01), Dollinger
patent: 5562962 (1996-10-01), Tung
patent: 5756173 (1998-05-01), Tung et al.
patent: 5849419 (1998-12-01), Josephy et al.
The Dow Chemical Company
Zirker Daniel
LandOfFree
Clear monolayer label filmstock does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Clear monolayer label filmstock, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Clear monolayer label filmstock will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1071012