Matrix free thin labels

A label construction comprises a temporary carrier web having a release surface and a label releasably adhered to the release surface. The label comprises a radiation cured face film in contact with the release surface of the carrier web and a layer of pressure sensitive adhesive on the side of the label opposite the carrier web, and may comprise indicia between the face film and the layer of adhesive. A protective backing covers the adhesive and has a second release surface in contact with the adhesive. Adhesion between the release surface of the protective backing and the layer of adhesive is weaker than adhesion between the release surface of the temporary carrier web and the face film. The protective backing can be removed from the label to expose the adhesive while leaving the label releasably adhered to the carrier web. The exposed adhesive is applied to a substrate and the temporary carrier web is removed, leaving the label adhered to the substrate.

BACKGROUND OF THE INVENTION 
This invention relates to pressure sensitive adhesive label construction, 
particularly to thin label constructions having radiation cured face 
films. 
Conventional pressure sensitive adhesive labels are adhered to the release 
surface of a carrier web in spaced apart relation. The web may be a 
plastic film but is usually a smooth paper, such as glassine, or kraft 
coated with a silicone release layer. The labels include a layer of 
pressure sensitive adhesive in contact with the release layer on a carrier 
web and a label facestock which may include indicia in one or more colors 
printed over the label facestock. The facestock may be paper or plastic 
such as vinyl. Indicia take the form of printed words, letters, or 
designs. Because such indicia are printed over the label facestock, they 
are subject to wear and abrasion. Clear protective coatings are sometimes 
applied over the indicia. Such labels, with or without printed indicia, 
are referred to as "laid-on" labels and they are in wide commercial use 
for attachment of various articles and materials for identification, 
advertising, decoration, or protection. 
Laid-on labels are made by die cutting as described in U.S. Pat. Nos. 
2,391,539 and 3,166,186, for example. A sheet or roll of a laminated 
construction comprising a layer of label facestock, a layer of pressure 
sensitive adhesive, and a temporary carrier web having a release surface 
in contact with the adhesive is provided. Discrete labels are formed on 
the carrier web by die cutting through the label facestock and the 
adhesive layer, without cutting through the carrier web, to define the 
periphery of individual labels. The facestock and adhesive surrounding the 
individual labels remain as a continuous, skeletal web or matrix which is 
then stripped from the carrier web leaving discrete spaced apart labels 
adhered to the carrier web. Indicia may be printed on the labels before or 
after die cutting and stripping of the matrix. Protective coatings may 
also be applied before or after stripping of the matrix. The practice of 
making laid-on labels by die cutting and stripping of matrix is wasteful 
of materials and entails the use and maintenance of precision die cutting 
machinery. 
Laid-on labels having an adhesive layer in contact with the release surface 
of a carrier web are typically dispensed in one of two ways. An individual 
label may be manually peeled from the carrier sheet and applied to a 
substrate. Alternatively, the carrier web may be bent over a sharp angle, 
for example, by drawing the carrier across an edge. The label is less 
flexible than the carrier web and fails to follow the carrier around the 
sharp angle, but instead becomes at least partly separated from the 
carrier web. The separated portion of the label may be applied directly to 
a substrate or grasped manually for removal from the carrier web. In both 
of these methods of label dispensing it is necessary that the label itself 
have sufficient rigidity and strength to survive removal from the carrier 
film and transfer to a substrate. In addition when a label is manually 
removed from carrier web it must have sufficient thickness to be readily 
grasped by the user. 
SUMMARY OF THE INVENTION 
In accordance with this invention, a label construction comprises a 
temporary carrier having a first release surface and a label releasably 
adhered to the release surface. The label comprises a face film in contact 
with the release surface and a layer of pressure sensitive adhesive on the 
side of the label opposite the carrier. The face film comprises radiation 
cured polymer. A protective backing having a second release surface is in 
contact with the adhesive layer. The adhesion between the adhesive and the 
release surface of the protective backing is weaker than the adhesion 
between the face film and the release surface of the carrier web, whereby 
the protective backing can be removed from the label to expose the 
adhesive while leaving the label releasably adhered to the carrier web. 
A preferred label construction in accordance with this invention comprises 
a temporary carrier web having a first release surface and a protective 
backing having a second release surface and a plurality of discrete labels 
releasably adhered to the first release surface. In a preferred self-wound 
embodiment such temporary carrier web can also be the protective backing 
(i.e., the carrier web has first and second release surfaces on opposite 
sides of the carrier web). Each label comprises a face film in contact 
with the first release surface, a layer of pressure sensitive adhesive on 
the side of the label opposite the carrier web, the face film comprising 
radiation cured polymer, and indicia between the face film and the layer 
of pressure sensitive adhesive. 
A label construction according to this invention is made by forming 
discrete label face films releasably adhered to a release surface of a 
carrier web by coating discrete areas on the release surface which 
correspond to labels being formed with at least one layer of radiation 
curable liquid and curing the liquid by exposure to polymerizing 
radiation. Pressure sensitive adhesive in liquid form is applied over the 
discrete label face films substantially in register with the label face 
films and is solidified. Discrete labels are thus formed, each having a 
face film releasably adhered to the first release layer on the carrier web 
and a pressure sensitive adhesive on the side of the label opposite the 
carrier web. The pressure sensitive adhesive is covered with a protective 
backing having a release layer in contact with the adhesive. Polymerizing 
radiation may be ultraviolet radiation or ionizing radiation such as 
electron beam or gamma radiation.

DETAILED DESCRIPTION OF THE INVENTION 
FIG. 1 illustrates a label construction according to this invention. A 
temporary carrier web 10 having a release surface 12 supports two labels 
14. Each label has a face film 16 releasably adhered to the release 
surface 12. Indicia 18 are printed on the face film 16, and both the 
indicia and portions of the face film not covered by the indicia are 
covered with a layer of pressure-sensitive adhesive 20. A backing sheet 22 
having a release surface 24 protects the adhesive from dust and dirt. The 
adhesion between the adhesive 20 and the release surface 24 of the 
protective backing is weaker than the adhesive between the face film 16 
and the release surface 12 of the carrier web. Thus, the protective 
backing can be removed, leaving the label 14 releasably adhered to the 
carrier web. Adhesion between the layer of adhesive 20 and a substrate to 
which the label is applied is stronger than adhesion between the face film 
16 and the release surface 12 on the carrier web, so that when the 
adhesive is pressed into contact with a suitable substrate, such as paper, 
metal, wood, hardboard, glass, or a painted surface, the carrier web can 
be removed leaving the label adhered to the substrate. 
Such a label construction provides a number of advantages. When the 
protective backing is removed, the label remains releasably adhered to the 
carrier with the adhesive side facing out. Thus, the label need not be 
removed from the carrier for application to a substrate, but can be 
applied to the substrate while still adhered to the carrier. The indicia 
are between the face film and the adhesive. When the label is applied to a 
substrate, as shown in FIG. 5, the indicia are protected from wear, 
abrasion, and solvents by the face film. Thus, there is little or no need 
for a wear-resistant overcoating on labels of this invention to protect 
the indicia. 
A great advantage is that such labels may be made very thin, having a face 
film (excluding indicia and adhesive) with a thickness in the range of 
from about 0.1 to about 2.0 mil, preferably from about 0.1 to about 1.5 
mil, (a mil being 0.001 inch). Thicker labels may of course be made. Such 
thin labels may be too thin to be removed manually from a carrier web. 
Thin labels of this invention may be too flexible to be dispensed in the 
ordinary way by drawing the carrier over a sharp angle, because a thin, 
flexible label will follow the flexible carrier without becoming partially 
detached therefrom. Providing an adhesive layer on the label on the side 
opposite the carrier web enables the user to transfer a label directly 
from the carrier to a substrate, even when the label is too thin and 
fragile to survive manual removal from the carrier. 
Such thin labels are highly decorative and appear almost to become part of 
the substrate to which they are applied. When a transparent face film and 
a transparent adhesive are used, indicia in such labels appear to be 
printed directly upon the substrate rather than being merely "stuck on." 
Application of such labels to a particular substrate, such as a curved 
container, may be easier than printing indicia directly on the substrate, 
and indicia in the labels are protected from wear by the face film. Such 
labels may be destructible, i.e., they may be impossible to remove in one 
piece from a substrate. Destructible labels have many useful applications. 
The label face film 16 comprises radiation-cured polymeric material that is 
formed by applying substantially solvent-free radiation-curable liquid to 
the release surface of the carrier web in at least the discrete area 
corresponding to a label being made and curing the liquid to a solid state 
by exposure to polymerizing radiation. Curing the liquid on the release 
surface of the carrier web forms a solid label face film releasably 
adhered to the release surface, the face film comprising a reaction 
product of radiation curable monomers. When ultraviolet radiation is used 
to cure the liquid, the face film also comprises a residue of at least one 
photoinitiator formed by exposure thereof to ultraviolet light. A 
plurality of label face films 16 may be formed on a carrier web by 
applying radiation-curable liquid to a plurality of discrete, spaced apart 
areas on the release surface corresponding to the labels being made. The 
liquid is applied as a continuous liquid film within each discrete area, 
but is not applied to portions of the release surface outside of the 
discrete areas, e.g. portions of the release surface between adjacent 
discrete areas. 
The label face film 16 may be opaque, translucent, or substantially 
transparent, and may be colored or colorless. An opaque face film is 
useful when a label without indicia 18 is made. Transparent face films 
permit indicia to show through clearly. When indicia 18 are present in the 
label, it is, of course, desirable to have a face film that is 
sufficiently transparent or translucent for the indicia to show through. 
The label face films may comprise more than one layer of radiation-cured 
polymers. Polymer of each layer may be the same or different. Each layer 
may be cured separately, or a plurality of layers of radiation-curable 
liquid may be applied and then cured at the same time. For example, a 
label face film may comprise a hard, wear-resistant layer in contact with 
the release surface of the carrier web and a tough, flexible layer over 
the hard layer for greater strength. Other variations in the number and 
kind of layers in the label face film may also be used. 
Any radiation-curable liquid capable of forming a solid, flexible film upon 
curing may be used in forming the label face films. A copolymerizable 
mixture of prepolymers and monomers that is curable or polymerizable to a 
solid state by exposure to radiation is preferred. 
Preferred monomers are acrylate monomers including acrylic acid, lower 
alkylacrylic acids such as methacrylic acid, and esters thereof. Preferred 
prepolymers are acrylated epoxy resins, acrylated polyester resins, 
acrylated urethane resins such as acrylated polyether-polyisocyanate 
resins and acrylated polyester-polyisocyante resins. It is preferred that 
the monomers employed include at least one monomer having two or more 
acrylate groups to promote rapid cross-linking polymerization, such as 
trimethylolpropane triacrylate. Additional cross-linkers include 
pentraerythritol-tetraacrylate and pentaerythritol triacrylate. Of the 
two, the tetraacrylate is preferred for faster cure rate and improved 
release of the cured film from the release surface of the carrier web. 
Useful acrylated epoxy resins are commercially available, for example; 
XD-8079 from Dow Chemical Company. 
Useful acrylated polyether-polyisocyanate resins and monomer solutions 
thereof for radiation curing are described in U.S. Pat. No. 3,989,609, the 
entire disclosure of which is incorporated herein by this reference. This 
patent describes compositions comprising a liquid prepolymer which is the 
reaction product of a polyisocyanate with a polyether triol and an 
unsaturated alcohol such as allyl alcohol, a copolymerizable acrylate 
ester monomer, and at least one monomer having three or more unsaturated 
acrylate or methacrylate groups to promote cross linking. Other radiation 
polymerizable film forming resins useful in the present invention are 
described in U.S. Pat. No. 3,844,916, the entire disclosure of which is 
incorporated herein by this reference. 
U.S. Pat. No. 3,857,768 describes polyacrylate-methacrylate compositions 
useful in the present invention. The entire disclosure of this patent is 
incorporated herein by this reference. 
The viscosity of the radiation-curable liquid may be varied by altering the 
relative proportions of the prepolymer and the copolymeriable monomer. 
Increasing the proportion of monomer will decrease the viscosity of the 
composition and vice versa. The viscosity is preferably relatively low so 
that a thin film of the liquid can be applied with conventional printing 
or coating equipment. The optimum viscosity depends, of course, upon the 
particular printing or coating equipment employed and can thus be readily 
determined by one skilled in the operation of such equipment. 
The radiation curable liquid may also include a wetting agent to improve 
wetting of the release surface on the carrier web, and an antifoam agent. 
Other ingredients such as pigments, dyes, leveling and flow promoting 
agents, inhibitors, or the like may also be included. 
Indicia, where desired, are printed over the cured face film. Conventional 
inks may be employed. Radiation curable inks are preferred. Indicia formed 
from radiation curable inks comprise a reaction product of 
radiation-polymerizable monomers. When ultraviolet light is used, 
radiation cured indicia also comprise the residue of at least one 
photoinitiator formed by exposure thereof to ultraviolet light. 
Commercially available inks or inks made by adding coloring agents such as 
pigments or dyes to the radiation polymerizable liquids described above 
may be used. 
A method of preparing label assemblies without die cutting is described in 
U.S. Pat. No. 4,022,926 to Keough, et al., the disclosure of which is 
incorporated herein by this reference. The patent describes a method 
comprising printing over the release surface of a temporary carrier web, a 
liquid pressure sensitive adhesive in a pre-determined pattern of discrete 
label areas separated by intervening areas of the carrier, solidifying the 
adhesive surface, forming a continuous film of radiation polymerizable 
liquid over each adhesive area, the film over each area being unconnected 
to films over adjacent areas, and exposing the films to radiation 
sufficiently to solidify them by polymerization. Indicia may then be 
printed on top of the solidified films. An overcoating over the indicia 
and base layer may be provided to add chemical or abrasion resistance. 
This method lends itself to rapid continuous production of label 
assemblies on carrier web and avoids the waste incident to the practice of 
die cutting and stripping of a matrix. 
Other layers may be included if desired, such as tie-coatings between 
layers to improve adhesion or an opaque coating between over the indicia 
and the face film and to provide a background of contrasting color for the 
indicia when viewed through the face film. 
The carrier web 10 may be a plastic film or sheet having desirable release 
properties such as polyethylene or polypropylene. Other materials such as 
polyester films, for example, Mylar (trademark of E. I. DuPont de Nemours 
and Company) may be used when treated with a suitable release agent 
including stearatometal complexes such as Aluminum Complex 101 from Du 
Pont. For reasons of economy the carrier web 10 may be paper, such as 
kraft or glassine having a release surface 12, ordinarily coated with 
low-density polyethylene. Protective backing 22 is a conventional glassine 
or kraft paper backing having a silicone coated release surface 24. 
Any conventional pressure-sensitive adhesive that can be applied in liquid 
form to the cured face films on the carrier web and solidified thereon may 
be used in the practice of this invention. It is preferable to apply the 
liquid adhesive substantially in register with the cured face films so 
that the layer of applied adhesive is coextensive with the face film and 
does not flow onto areas of the carrier web release surface between the 
discrete label face films. The liquid adhesive can be applied by any 
conventional printing or coating method capable of selectively applying 
the adhesive to the cured face films. The adhesive can be applied as a 
solvent solution. Preferably for speed and avoidance of solvent fumes, the 
adhesive is applied as a molten hot melt or as a radiation curable liquid. 
The adhesive can be applied through a mask or by a technique such as silk 
screen printing. 
Radiation polymerizable pressure sensitive adhesive liquids are known and 
are described, for example, in an article entitled, "Radiation 
Polymerization for Pressure Sensitive Adhesives," CHEM-TECH, September, 
1974, pages 539-543, and incorporated herein by this reference. Such 
adhesives as disclosed therein also include hot melt pressure sensitive 
liquids. Radiation curable pressure sensitive adhesive liquids may also be 
made by incorporating tackifying resins into the radiation curable 
acrylate systems described above for use in forming the label face films 
or by employing suitable acrylic elastomers of the type used in 
conventional synthetic pressure sensitive adhesives which have reactive 
groups copolymerizable by radiation with acrylate monomers and 
prepolymers. A layer of pressure sensitive adhesive formed by irradiating 
radiation curable liquid comprises a reaction product of 
radiation-polymerized monomers. When ultraviolet radiation is used, the 
layer of adhesive also comprises the residue of at least one 
photoinitiator formed by exposure thereof to ultraviolet light. 
A preferred embodiment of the present invention is illustrated in FIG. 2 in 
which carrier webs 26, 34, and 36 comprise a paper web 32 such as kraft or 
glassine having one one side a first release surface 28 and on the other 
side a second release surface 30. The carrier web 26 acts as both a 
carrier web for a label 31 which has been formed on the carrier web as 
described above and as a protective backing for another label 31' on an 
adjacent portion of carrier web 34. Another portion 36 of carrier web 
covers and protects the adhesive of label 31 on the portion 26 of carrier 
web. Portion 36 of carrier web is shown partially removed to illustrate 
how the label 31 remains releasably adhered to portion 26 of carrier web. 
A construction as illustrated in FIG. 2 can be made by forming labels as 
described above on a carrier web having a release surface for the face 
film of the labels on one side and release surface for the adhesive on the 
other side. A plurality of portions of carrier web having such labels 
releasably adhered thereto are then laminated to provide a cohesive 
laminate or blocking stack comprising alternating layers of label and 
carrier web. Release surface 28 on the carrier web corresponds to release 
surface 12 in FIG. 1. Release surface 30 on the carrier web corresponds to 
release surface 24 on the protective backing in FIG. 1. Thus, when two 
portions of carrier web having a label between them are peeled apart, the 
release surface 30 preferentially releases from the adhesive side of the 
label, thus exposing the adhesive while leaving the label releasably 
adhered to the release layer 28 of the portion of carrier web upon which 
the label was formed. 
Labels made as illustrated in FIG. 2 are convenient to use. A plurality of 
sheets of carrier web having labels thereon are laminated to form a 
cohesive laminate or stack of labels and sheets of carrier web. Each sheet 
of carrier web may have one or more labels on it. Preferably the laminated 
stack is covered with a sheet of carrier web having no labels thereon, as 
illustrated. When it is desired to apply a label, the topmost piece of 
carrier web is peeled away exposing the adhesive of an underlying label. 
The laminated stack of labels is then manipulated to apply the exposed 
label to a substrate. The stack is then removed from the substrate leaving 
the label adhered to the substrate. Another piece of carrier web can then 
be removed from the top of the stack leaving another label exposed, and so 
on. 
FIG. 3 and 4 illustrate another preferred embodiment of the present 
invention. FIG. 3 illustrates a self-wound roll 38 of labels 14 on a 
continuous strip of carrier web 40. As illustrated more clearly in FIG. 4, 
the carrier web 40 comprises a paper web 32 having a first release coating 
28 on one side and a second release coating 30 on the other side. Release 
surface 28 as described above is, for example, polyethylene. Release 
surface 30 is, for example, silicone. 
The relative release properties of the release surfaces 28 and 30 are such 
that when a portion of carrier web 40 is unwound from the roll the labels 
remain releasably adhered to the portion of carrier web being unwound and 
the adhesive side of each label is exposed. Thus, a portion of carrier web 
with a label thereon can be unwound from the roll and the label thereon 
transferred to a substrate. It is apparent that such a label construction 
can be readily adapted to dispensing with a mechanical label dispenser. 
For example, the carrier web bearing a label may be passed between a 
roller and a substrate with the adhesive side of the label contacting the 
substrate under the roller so that the label is transferred to the 
substrate. 
The embodiment of the invention illustrated in FIG. 3 and FIG. 4 is called 
a "self-wound" roll because the coils of the roll are adhered to one 
another through the layers of adhesive 20 on the labels much as the coils 
of a roll of ordinary adhesive tape are adhered to one another. When a 
strip of ordinary labels in which the adhesive is between the carrier web 
and the facestock of the label is wound upon itself to form a roll, the 
coils of the roll do not adhere to one another, and such a roll is not 
"shelf-wound" as the term is used herein. 
FIG. 5 illustrates a label of the present invention as it appears after 
being applied to a substrate 42. The layer of adhesive 20 secures the 
label to the substrate. The indicia 18 are between the adhesive and the 
face film of the label, which protects the indicia from wear and abrasion 
but permits the indicia to be observed. 
FIG. 6 illustrates another label of the present invention as applied to a 
substrate 42. The label comprises a layer of adhesive 20, indicia 18, face 
film 16, and in addition a layer 44 between the adhesive on the one hand 
and the face film and indicia on the other to provide a background for the 
indicia of contrasting color. Both the indicia 18 and portions of layer 44 
are observable through the face film 16. The background layer 44 is 
preferably formed by applying a radiation curable liquid in register over 
the cured face film and dried or cured indicia and then curing the liquid 
by exposure to radiation. The layer of radiation cured material may be 
substantially opaque. 
FIG. 7 schematically illustrates a method for making a self-wound roll of 
labels in accordance with the preferred embodiment of this invention. A 
continuous strip of carrier web 61 is unrolled from a roll 60. The carrier 
web 61 has a first release coating 28 on one side, and a second release 
surface 30 on the other side as previously described. The web passes 
through a coating or printing station 52 which may be any suitable press 
such as a flexographic rotograver or rotary screen press. At printing 
station 52 a radiation curable liquid composition is applied in a 
predetermined pattern of discrete areas corresponding to the labels being 
made. The liquid is applied as a continuous film within each discrete area 
of the carrier web but is not applied to portions of the carrier web 
outside the discrete areas. A sufficient thickness of radiation curable 
liquid is applied in one or more layers to provide a cured label face film 
having a thickness of at least about 0.1 mil. A label face film of any 
desired thickness may be built up by applying and curing a plurality of 
layers of radiation curable liquid. In accordance with a preferred 
embodiment of this invention, the thickness of the face film is between 
about 0.1 and about 1.5 mil, more preferably between about 0.3 and about 
1.0 mil. 
The carrier web 61 carrying the discrete areas of applied radiation curable 
liquid advances past a source of ultraviolet radiation 53. The intensity 
of radiation and the time of exposure are suffient to at least partially 
solidify and preferably to fully cure the radiation curable liquid within 
the discrete areas on the carrier web. The carrier web carrying thus 
formed label face films advances to printing or coating station 54 in 
which indicia are printed on the label face films using a radiation 
curable ink. The web then advances past source 55 of ultraviolet radiation 
where the ink in the indicia is cured. It should be noted that because the 
indicia will be viewed through the film upon which they are printed they 
must be printed in reverse upon the label face films so that when viewed 
through the films they will appear correct, left to right. The carrier web 
advances then through printing or coating station 56 in which a background 
layer of radiation curable liquid is applied over the indicia and the face 
film to provide a background of contrasting color to the indicia. The 
background layer may be applied over only a portion of each label face 
film or it may be substantially coextensive with each label face film. 
However, background layer is not applied to portions of the carrier web 
between the discrete label face films thereon. The web advances past 
ultraviolet source 57 where the background layer is cured. The web then 
advances to printing or coating station 58 at which pressure sensitive 
adhesive in liquid form is applied over the background layer and 
substantially in register with the label face films but is not applied to 
portions of the carrier web between the discrete labels being made. The 
adhesive is preferably a radiation curable liquid adhesive which is then 
cured to a semi-solid tacky adhesive state at ultraviolet source 59. The 
web 61 now carrying a series of finished labels is then wound upon itself 
in the manner shown with the adhesive sides of the labels facing toward 
the center of the roll. The coils of the rolls adhere to one another to 
provide a self-wound roll 65 having the desirable characteristics 
hereinabove described. 
If desired, to assure that all the layers of the finished label are fully 
cured, an additional source of radiation 63, for example, ultraviolet 
radiation or electron beam radiation may be provided after the ultraviolet 
source 59. When a plurality of discrete labels are formed side by side on 
the web as it advances past the printing stations and sources of 
radiation, the carrier may be slit with a conventional slitter between 
rows of labels to provide individual self wound rolls of labels. 
Specific ultraviolet radiation curable coating compositions useful for 
forming the label face films 16 are given below in Examples I and II. The 
formulation in Example II is preferred. 
EXAMPLE I 
UV Curable 100% Solids Liquids 
______________________________________ 
UV Curable 100% Solids Liquids 
Parts by Weight 
______________________________________ 
XD-8079 10.0 
Uvimer 540 20.0 
Wetting agent 0.3 
Witco 3054 0.2 
dioctylphthalate 0.3 
diethoxyacetophenone 0.5 
______________________________________ 
XD-8079 is a UV curable acrylated epoxy composition of Dow Chemical 
Corporation. Uvimer 540 is a polyethylenically unsaturated liquid 
prepolymer of high reactivity available from the Polychrome Corporation. 
The wetting agent is a silicone wetting agent from Dow Corning 
Corporation. Witco 3054 is a silicone antifoam agent from Witco Chemical 
Corporation. Dioctylphthalate is a plasticizer and diethoxyacetophenone is 
a photoinitiator for curing by ultraviolet radiation. 
EXAMPLE II 
______________________________________ 
Uvimer 745 30.0 
polyethylene glycol diacrylate 
3.0 
trimethylol propane triacrylate 
1.0 
1, 6, hexanediol diacrylate 
5.0 
2 hydroxyethyl acrylate 3.0 
diethoxyacetophenone 0.4 
______________________________________ 
Uvimer 745 is another polyethylenically unsaturated liquid oligomer of the 
Polychrome Corporation. The next four ingredients are reactive monomers. 
EXAMPLE III 
A piece of commercially available kraft paper carrier having a low density 
polyethylene release surface on one side was coated on the other side with 
a conventional silicone release agent which was dried and cured on the 
paper. By means of flexographic printing discrete areas on the 
polyethylene coated side of the carrier were coated with a 0.3 mil thick 
layer of the radiation curable liquid formulation of Example II. The 
carrier was then passed under a medium pressure mercury lamp as a source 
of ultraviolet radiation. The lamp was rated at 200 watts per inch and the 
carrier was passed about 1/2 inch from the lamp at the rate of 50 feet per 
minute. The liquid was fully cured to provide discrete label face films on 
the carrier. 
Indicia were then printed on the label face films with a standard 
solvent-based flexographic ink and dried with a stream of hot air. A 0.3 
mil thick layer of a commerically available pressure sensitive adhesive 
comprising a rosin ester modified styrene-isoprene block copolymer 
solution diluted to about 30 weight percent solids with toluene was then 
applied in register over the label face films and indicia and allowed to 
dry. Sheets of carrier web bearing thus formed labels were laminated to 
form a cohesive stack and then separated. Upon separation of adjacent 
sheets of carrier web, labels remained adhered to the sheet of carrier web 
upon which they were formed and the adhesive sides of the labels were 
exposed. The adhesive side of a label still releasably adhered to its 
carrier sheet was applied to a sheet of paper and the carrier sheet was 
removed. The label transferred cleanly from the carrier sheet to the 
paper, and had a thickness of about 0.6 mil. 
Although the present invention has been described with reference to 
particular details and embodiments thereof, the particulars of the 
description are not intended to limit the invention, the scope of which is 
defined in the following claims: