High molecular weight vinyl acrylic combined with low molecular weight vinyl acetate-maleate for controlled permanent tack and method of making same

An unsupported decorative film of a polymeric composition having controlled permanent tack, the polymeric composition being a blend of 86 to 88% of a polyvinyl acetate-acrylic copolymer of high molecular weight and low residual tack and 12 to 14% of a polyvinyl acetate-maleate copolymer of low molecular weight and high residual tack. Other chemicals may be added to the blend to control color, viscosity and resistance to microorganisms. A casted film of this composition adheres to most surfaces, but may be forcefully removed and relocated. The film is used for decorative art pieces.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention pertains to an unsupported decorative film of a polymeric 
composition having controlled permanent tack for temporary adhesion to all 
types of surfaces and a method of making said film. The film may be used 
for decorative purposes, may or may not be transparent to light and may be 
colored. The decorative formed film of this invention is of value in the 
field of arts and crafts. 
2. Description of the Prior Art 
The principal object of this invention is to provide a decorative film as 
an arts and crafts medium which is tough, flexible and permanently tacky. 
The film is designed to be arranged in a decorative, physical form and to 
be itself decorative. In order to be able to display this decorative 
formed film and to change the display from time to time, it is necessary 
that this decorative formed film be able to stick to many types of 
surfaces and have a permanent tack. The person using this art form can 
make a decorative art creation in the form of a film which may or may not 
be transparent to light, yet can bear color, much like tinted glass. To 
achieve this principal object, the film must be tough, flexible and 
adhesive. The most important property of this decorative formed film is 
that it have the proper permanent tack which will allow the formed film 
piece to be placed upon any surface, this placement supporting the 
decorative film piece, and which will allow the removal of the decorative 
film piece from one surface and its replacement on another surface without 
any loss of tack. 
Thus, the polymeric composition of this invention must possess some very 
unique properties. In a search of the literature and of the marketplace, 
the inventors found that each apparently suitable polymer had one or more 
shortcomings. The inventors were searching for a film forming polymeric 
composition with the appropriate controlled permanent tack. The tack level 
has to be of such a nature as to stick to many different kinds of surfaces 
over a broad temperature range. 
A permanently tacky adhesive or compound is not new or novel. There are 
many such compositions in use. However, these formulations were designed 
mainly as adhesives to stick one object to another object on a temporary 
basis, such as the adhesive on a finger bandage. But these adhesive masses 
would not be acceptable to support or make the decorative formed films of 
this invention. 
Tack is a very difficult property to define. It certainly implies stick, as 
for example, the human skin must have a degree of tack to objects, or our 
hand would not be able to pick up or hold things rather easily. It is not 
only a chemical property as defined by molecular weight, solubility, or 
incompatibility of substances, but is also a mechanical property, as 
defined by displacement, deformation and contact. So, it is known that 
both chemical and mechanical considerations would have to be employed. It 
is also known that simple physical testing was not sufficient, for tack is 
too complex a property to evaluate with one simple test, but rather it 
would require painstakingly long empirical studies of trial and error and 
of end use evaluation on all kinds of surfaces, under all kinds of 
conditions of heat, moisture, and temperature. 
It is common knowledge that tack, or permanent tack, can be achieved by the 
60-40 principle. This says that 60 parts of a high molecular resin mixed 
with 40 parts of a low molecular resin or compound will result in a tacky 
mass. This principle holds quite well. However, compositions of this 
design were not acceptable to the requirements of this invention. They 
suffered from draw backs of cold flow, creep, migration, extreme 
variability of tack as to temperature, and complete loss of tack on 
exposure to moisture. Long term aging became a problem, the degree of tack 
would gradually lessen, and a lot of the composition in time would lose 
their tack. 
To have a clear film that is transparent, the polymeric composition must be 
amorphous. This requirement eliminates a lot of polymers. However, 
amorphous or noncrystalline structures are more prone to permanent change 
when exposed to forces of chemical or mechanical stress. Hence, the 
amorphous polymer used in this invention must be very stable chemically, 
and not too thermoplastic so as to hold an acceptable level of 
physico-mechanical stability, especially as it relates to tack. 
SUMMARY OF THE INVENTION 
This invention provides a new art and craft medium not heretofore 
available. A special polymeric composition is provided in a suitable 
container from which the artisan can cast a liquid composition into a 
decorative form. The casting phase is done on a non-porous, release, 
plastic sheeting such as polypropylene, polyethylene or polyester film, or 
resin-coated release papers, whereby the coating is polypropylene, 
polyethylene, polyester, silicon or various hydrocarbon waxes. The liquid 
composition then sets to a film that is tough, flexible and permanently 
tacky. The casting phase is done on cellophane sheeting or similar 
nonporous material. With the polymeric film-forming composition, an edging 
compound is provided that for framing the casting liquid. After the 
casting phase, the composition is allowed to act, whereby a clear film 
results that is transparent to light, bearing color and form that then can 
be supportably affixed to any surface. The artpiece can be removed and 
affixed to many different objects such as windows, walls, furniture, or 
any kind of surface. 
The following polymeric composition satisfies this invention. The polymeric 
part of the final composition consists of two polymer entities: 
Polymer I--A polyvinyl acetate-acrylic copolymer of high molecular weight, 
and low residual tack, and, 
Polymer II--A polyvinyl acetate-maleate copolymer of low molecular weight, 
and high residual tack. 
Both of these polymers are of special design and are made especially for 
this invention. 
Polymer I readily forms a film that is low in tack, glossy, very clear, and 
flexible. Polymer II readily forms a film that is very high in tack, 
glossy, very clear and soft. 
Polymer I is very different from Polymer II. Polymer I is not a tacky 
Polymer. It is tough and very stable to the influence of moisture or 
temperature. However, it has a very critical performance factor, and that 
is that it will absorb 10-12% moisture. This feature is extremely 
important to achieve proper tack control. Polymer II is very tacky and has 
excellent moisture resistance, but mechanically offers no stability. 
In the final composition a blend of Polymer I and Polymer II was found to 
be necessary and critical to obtain controlled permanent tack. This blend 
ratio was found to be: 
Polymer I; 88-86 
Polymer II; 12-14 
this blend ratio gave the final casted film just the right adhesive tack 
properties. The coated film of the proper blend of Polymer I and II was 
tried for adhesion to all kinds of surfaces such as metal, wood, paper, 
paper board, coated cloth, painted woods, and glass, under all sorts of 
conditions of humidity and temperature. The adhesive or stick feature of 
the blend film was excellent under all extremes of humidity from 20-90%, 
and temperatures from 0.degree. C. to 30.degree. C. Metallic and glass 
surfaces will have condensed moisture which can destroy tack, but the 
blend film will pickup this moisture without losing tack, and transport it 
through the film in time. This is a very important performance feature, 
for without this feature, the film would not stick to moisture 
contaminated surfaces. 
Other chemicals may be added to obtain color, viscosity control and 
resistance to micro-organisms. The preferred composition contains a color 
and may be supplied to the arts and crafts field in many basic colors so 
that most colors can be achieved by blending the basics. The artisan will 
first frame the art-piece with a black color in about a 1/4 line, allow it 
to partially dry, then fill in with the appropriate colors to cast the 
final film art. After it has dried, or set, it is now ready to be 
supportively attached to a surface for display. 
DESCRIPTION OF THE PREFERRED EMBODIMENT 
This invention pertains to an unsupported decorative formed film of a 
polymeric composition having controlled permanent tack for temporary 
adhesion to all types of surfaces, which film is color bearing and may or 
may not be transparent. The formed film must be tough, flexible, adhesive 
and have a controlled permanent tack which allows for film piece placement 
on any surface over a broad temperature range. 
In the preferred embodiment, the following polymeric composition satisfies 
the objects of this invention. The polymeric part of the final composition 
consists of two polymer entities: 
Polymer I--A polyvinyl acetate-acrylic copolymer of high molecular weight, 
and low residual tack, and, 
Polymer II--A polyvinyl acetate-maleate copolymer a low molecular weight, 
and high residual tack. 
Both of these polymers are of special design and are made especially for 
this invention.

The making and composition of Polymer I is prepared as follows. Polymer I 
is made by emulsion polymerization under a blanket of nitrogen. The 
formula is: 
______________________________________ 
Ingredients Parts By Weight 
______________________________________ 
Vinyl acetate 77.0 
Itaconic acid 1.5 
Ethyl acrylate 12.0 
Glycidyl methacrylate 
2.5 
Thiodiethylene glycol 
4.0 
Sodium Lauryl sulfate 
2.5 
Ammonium persulfate 0.4 
Water 100.0 T.T.S 50% 
______________________________________ 
The water is charged to the reactor, then 14 parts of vinyl acetate 1.5 
parts of itaconic acid, 2.5 glycidyl methacrylate, 4.0 parts of 
thiodiethylene glycol, 2.5 parts of sodium lauryl sulfate, an 0.4 parts of 
ammonium persulfate are added. This mixture is then heated to 84.degree. 
C., at which time a mixture of 63 parts of vinyl acetate and 12 parts of 
ethyl acrylate are added dropwise to the reactor. The temperature is 
maintained while the addition is made over a period of 45 minutes. The 
temperature then rises to 94.degree. C. and the conversion is complete to 
about 96 to 98%. The latex solids are about 47 to 49%. The batch is cooled 
and filtered. 
The making and composition of Polymer II is as follows. Polymer II is made 
by emulsion polymerization under a blanket of nitrogen. The formula is: 
______________________________________ 
Ingredients Parts By Weight 
______________________________________ 
vinyl acetate 56.0 
methacrylic acid 1.5 
dioctyl maleate 37.0 
sodium lauryl sulfate 
3.5 
hydroxyethyl cellulose 
1.5 
ammonium persulfate 
0.6 
water 100.0 
______________________________________ 
The water is charged to the reactor, then 8 parts of vinyl acetate, 1.5 
parts of methacrylic acid 5.5 parts of dioctyl maleate, 3.5 parts of 
sodium lauryl sulfate, 1.5 parts of hydroxy ethyl cellulose (MW2-4000), 
and 0.6 parts of ammonium persulfate are added. This is heated to 
84.degree. C., at which time a mixture of 48 parts of vinyl acetate and 
31.5 parts of dioctyl maleate are added dropwise to the reactor. The 
temperature is maintained while the addition made over a period of 90 
minutes. The temperature rises to 96-97.degree. C. The conversion is 
complete to about 96-97%. The latex solids are about 47 to 48%. The batch 
is cooled and filtered. 
Polymer I readily forms a film that is low in tack, glossy, very clear, and 
flexible. A 4 mil film has the following typical properties: 
______________________________________ 
tensile strength 150-200 psi 
% elongation at break 
175-225 
tack by sq. in. foot, +20.degree. C. 
4-5 lbs. 
tack by sq. in. foot, 0.degree. C. 
2 lbs. 
melting point 140-145.degree. C. 
moisture regain; 90% R.H. 30.degree. C. 
6-7% 
moisture regain; 70% R.H. 20.degree. C. 
5-6% 
moisture regain; 50% R.H. 20.degree. C. 
5-6% 
moisture regain; 20% R.H. 20.degree. C. 
4-5% 
moisture pick up 10-12% 
% creep, 20.degree. C., 24 hrs. 
5-6% 
resistance to sunlight 
excellent 
molecular weight million and above 
______________________________________ 
Polymer II readily forms a film that is very high in tack, glossy, very 
clear and soft. A 4 mil film has the following typical properties: 
______________________________________ 
tensile strength 10-15 psi 
% elongation at break 
2000% 
tack by 1 sq. in. foot, 20.degree. C. 
40-50 lbs. 
tack by 1 sq. in. foot, 0.degree. C. 
35-45 lbs. 
melting point 120-125.degree. C. 
moisture regain, 90%, R.H. 30.degree. C. 
0.5-0.75% 
moisture regain, 70%, R.H. 20.degree. C. 
0.5-0.75% 
moisture regain, 50%, R.H. 20.degree. C. 
0.5-0.75% 
moisture regain, 20%, R.H. 20.degree. C. 
0.5-0.75% 
moisture pick up 1-2% 
% creep, 20.degree. C., 24 hrs. 
extreme 
resistance to sunlight 
excellent 
molecular weight 55-35,000 
______________________________________ 
From the above physical data, it can be seen that Polymer I is very 
different from Polymer II. Polymer I is not a tacky polymer. It is tough 
and very stable to the influence of moisture or temperature. However, it 
has a very critical performance factor, and that is that it will absorb 
10-12% moisture and this feature is extremely important to achieve proper 
tack control. Polymer II is very tacky, excellent moisture resistance, but 
mechanically offers no stability. 
In the preferred embodiment, a blend of Polymer I and Polymer II was found 
to be necessary and critical to obtain controlled permanent tack. This 
blend ratio was found to be: 
Polymer I; 88-86 
Polymer II; 12-14 
This blend ratio gives the final casted film just the right adhesive tack 
properties. The typical film properties of a blend of Polymer I and 
Polymer II is as follows: 
______________________________________ 
tensile strength 140-180 psi 
% elongation at break 
200-250 
tack by 1 in. foot, 20.degree. C. 
7-8 lbs. 
tack by 1 in. foot, 0.degree. C. 
7-8 lbs. 
melting point 140.degree. C. 
moisture regain, 90% R.H. 30.degree. C. 
5-7% 
moisture regain, 70% R.H. 20.degree. C. 
5-6% 
moisture regain, 50% R.H. 20.degree. C. 
5-6% 
moisture pickup 9-10% 
% creep, 20.degree. C. 24 hrs. 
7-10% 
resistance to sunlight 
excellent 
molecular weight mixed, but millions 
______________________________________ 
The coated film of the proper blend of Polymer I and II was tried for 
adhesion to all kinds of surfaces such as metal, wood, paper, paper board, 
coated cloth, painted woods, and glass, under all sorts of conditions of 
humidity and temperature. The adhesive or stick feature of the blend film 
was excellent under all extremes of humidity from 20-90%, and temperatures 
from 0.degree. C. to 30.degree. C. Metallic and glass surfaces will have 
condensed moisture which can destroy tack, but the blend film will pickup 
this moisture without losing tack, and transport it through the film in 
time; this is a very important performance feature, for without this 
feature, the film would not stick to moisture contaminated surfaces. 
It should be understood that the stick performance, or adhesiveness to the 
various surfaces, under varied conditions was adjudged by end-use testing. 
The initial stick performance was noted, whereby when the art-piece is 
affixed to a surface, either it would stick immediately and sufficiently, 
or it would simply not stick, which resulted in a performance failure. If 
the art-piece would stick acceptably, initially, then it must stay affixed 
in place, indefinitely, until forceably removed, under varied 
environmental conditions. Only a polymeric composition as defined above, a 
blend of Polymer I and Polymer II would meet the stringent requirement of 
initial stick, and long-term stable surface adhesion. 
Once the proper polymeric composition is obtained, then a final formula is 
prepared to include such chemicals as are necessary to obtain color, 
viscosity control, and resistance to micro-organisms. The final formula 
for the film casting composition is -- 
______________________________________ 
Ingredients Parts By Weight 
______________________________________ 
1. Polymer I 88-86 
2. Polymer II 12-14 
3. Hydroxethyl cellulose 
0.08-0.14 
4. Poly acrylic acid 0.035-0.15 
5. Pigment Colorant Dispersion 
2-10 
6. Fungicide 0.004-0.10 
7. Ammonium Hydroxide 
0.14 
______________________________________ 
The above composition contains a color, and obviously, it is supplied to 
the Arts and Craft field in many basic colors, so that most colors can be 
achieved by blending the basics. 
This polymeric composition is provided in a suitable container from which 
the artisan casts the liquid composition into a decorative form. The 
liquid composition then sets to a film that is tough, flexible and 
permanently tacky. The casting phase is done on a non-porous, plastic, 
release sheeting or a resin-coated release paper. With the polymeric 
film-forming composition an edging compound is provided that provides the 
framing for the casting liquid. After the casting phase, the composition 
is allowed to set, whereby a clear film results that is transparent to 
light, bearing color and form that now can be supportably, affixed to any 
surface. The art-piece can be removed and affixed to many different 
objects such as windows, walls, furniture, etc., this is a distinct 
advantage. For colored art pieces, the artisan will first frame the 
art-piece with a black color in about a 1/4" line, allow it to partially 
dry, then fill in with the appropriate colors to cast the final film art. 
After it has dried, or set, it is now ready to be supportively attached to 
a surface for display.