Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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This invention relates to a laminate having a base
of highly plasticized polyvinyl chloride and a lamina of co-
polymer of 60-30 parts of acrylonitrile and 40 to 70 parts
2-ethylhexyl methacrylate adhered thereto.
Copolymers of acrylate/vinyl nitrile are trans-
parent and have useful properties of forming films by cast-
ing, calendering or extrusion. Unfortunately~ these copoly-
mers have poor adhesion to highly plasticized polyvinyl
chloride, and thus laminates of these cannot be readily
made. In general, the film laminates of this nature can
only be made by incorporating organic isocyanate or polyiso-
cyanate into polyvinyl chloride and/or the copolymer. These
laminates are very desirable for outdoor usage where resis-
tance to sunlight and weathering is required.
Canadian Patent 820,268 discloses how to produce
a brittle laminate instead of a highly flexible laminate
where the base is a polymer or copolymer of acrylic acid
ester and the exposed lamina is non or low plasticized poly-
vinyl chloride, preferably less than 20 percent. Also, the
exposed polyvinyl chloride does not weather well.
An object of this invention is to provide films
of the above copolymers that have good adhesive character-
istics and thus permit laminates to be readily made with
substrates such as highly plasticized polyvinyl chloride
where the former serves as a top-dressing and dirt releas-
ing agent. mis type of composite film has better service
life than the single polyvinyl chloride film due to the
protection afforded by the top or exposed coating in the
prevention of plasticizer extraction, the screening effect
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for ultraviolet light, and the prevention of dirt pick--~p
which tends to degrade the film prematurely.
An embodiment of this invention is a highly
flexible, weather resistant laminate comprising a base of
polyvinyl chloride containing 30 to 100 parts plasticizer
per 100 parts polyvinyl chloride, having adhered to at least
one f~ce thereo~ a layer of a copolymer of 60 to 30 parts of
acrylonitrile with 40 to 70 parts of 2-ethylhexyl methacrylate.
The advantages of this invention can be readily
obtained by preparing a copolymer of a 2-ethylhexyl metha-
crylate/acrylonitrile and then using these copolymers alone
to form a laminate with a highly plasticized polyvinyl chlo-
ride, without the need to use adhesives in the substra~e
polyvinyl chloride and/or copolymer or isocyanate.
The composite films were made up of these copoly-
rners with highly plasticized polyvinyl chloride. Further
variations on all these components are possible. Representa-
tive examples of these useful and well known;plasticizers
are dialkyl adipate esters, dialkyl azelates, some glycol di-
benzoate esters, epoxy derivatives including epoxidized soy-
bean oil, epoxidized tall oil and some epoxy resins, glycol-
lates such as butyl phthalyl butyl glycollate, mellitates
such as trialkyl trimellitates, phosphate esters including -
triaryl, trialkyl and alkyl-aryl combinations, derivatives of
phthalic acid with emphasis on dialkyl and alkyl benzyl phtha-
lates, polyesters of various dibasic acids with glycols (e.g.
adipic, azelaic and phthalic acids with various glycols termi-
nated with a monofunctional compound), some pentaerythritol
derivatives, esters of citric acids and sebacic acids. These
.
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plasticizers are added to the polyvinyl chloride in amounts
of from 30 parts up to 100 parts, to obtain the highly fiex-
ible, good weathering laminate of this invention. They include
ratios of two monomers, various alkyl methacrylates where the
alkyl group contains 1 to 30 carbon atoms and various vinyl
nitriles such as methacrylonitrile and ethacrylonitrile. Al-o
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included is a composite film of highly plasticized polyvinyl
chloride with a copolymer of 2 ethylhexyl acrylate and metha-
crylonitrile. The film thickness of these copolymers and
polyvinyl chloride which make up the composite film can be
varied. The preferred ones are about two mils for these co-
polymers and about 10 mils for polyvinyl chloride.
This object is achieved by polymerizing a mixture
of about 40 to 70 parts 2-ethylhexyl methacrylate monomer
and 30 to 60 parts of acrylonitrile monomer with a free radi-
cal initiator such as the peroxide catalysts to yield a poly-
mer soluble in tetrahydrofuran (THF) and readily castable
from THF solution as a flexible film or otherwise shaped into
the desired article. Usually the preferred copolymers of
this invention can be made from the following precursors in
amounts of about 40 to 70 phr (parts per hundred) of 2-ethyl-
hexyl methacrylate (2-EHMA) and about 60 to 30 phr of acrylo-
nitrile (AN). Where emulsion polymerization is used to make
the polymer, various modifiers such as the aliphatic and
aryl mercaptans or disulfides or even carbon tetrachloride,
carbon tetrabromide, chloroform or iodoform can be used to
advantage to control the polymer molecular weight and related
physicals.
Also, the polymer properties can be modified to
build in certain desirable attributes by including in the
polymerization recipes crosslinkers such as triallyl cyanu-
rate and ethylene glycol dimethacrylate. Small amounts of
these crosslinkers, preferably 0.2 to 1.5 phr are desirable
if the polymer is to be extended to form films.
The polymerization of the new copolymer of the
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present invention may be carried out in any conventional man-
ner, although polymerization in an aqueous emulsion is pre-
ferred. Alternately, polymerization may be carried ou-t in
an aqueous suspension system, or in solution in a suitable
well-known solvent for the monomer, such as methyl ethyl
ketone and tetrahydrofuran.
Whatever method of polymerization is employed,
any catalyst commonly employed may be used, including acti-
nic radiation, peroxygen compounds such as hydrogen peroxide,
cumene hydroperoxide and persulfates and percarbonates and
azo or diazo compounds. These catalysts may be activated
when used in combination with a reducing substance such as
sodium and ferrous salts. Any of the usual emulsifying
; agents may be used, including ordinary soaps, such as the
alkali metals of fatty acids including sodium oleate, and
the detergents generally known as the sulfates and sulfo-
nates, such as sodium lauryl sulfate and sodium isopropyl
naphthalene sulfonate.
Polymerization may be carried out in the presence
of air, but faster reactions are observed in the absence of
oxygen at temperatures ranging from -30C. to 110C., al-
though preferred temperatures range from about 5C. to
about 80C.
A series of emulsion polymerizations of 2-EHMA/
AN were carried out in eight-ounce bottles as well as in
five-gallon reactors. All the ingredients (0.05 phr potas-
sium persulfate, 0.5 phr divinylbenzene, l.0 phr tertiary
dodecyl mercaptan (t-DDM), 2.0 phr sodium tetradecyl sul-
fate, lO0 phr total monomers in the ratio desired in the
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copolymer and 150 phr deionized water) were charged into
eight-ounce bottles or five-gallon reactors and flushed well
with nitrogen and -then reacted at 50C. to about 40 percent
solids in 24 hours. Typically 60 parts 2-EHMA is used with
40 parts AN in the conventional polymerization recipe. The
whole bottle was cooled to room temperature and three phr
distilled water and 0.25 phr 30 percent H202 added and agi-
tated for 20 minutes. Finally, this polymer was coagulated
in 1.5 percent warm MgS04 solution (25-40C,), washed tho-
roughly several times with distilled water and dried in an
oven at 50C. for about one day. This copolymer consist-
ed of 60/40 2-EHMA/AN respectively.
To those skilled in the art, one knows that various
ingredients such as lubricants, stabilizers, pigments, toners,
surfactants, ultra-violet absorbers, antioxidants, can be
added to the film depending upon the intended use and na-
ture thereof. In addition, the 2-EHMA/AN polymer can be
extruded using proper equipment and conditions.
Polyvinyl chloride (PVC) resin was plasticized
with 40 parts of plasticizers composed of 22.8 parts diiso-
octyl phthalate, 7.4 parts N-octyl N-decyl phthalate, 5.7
parts tricresyl phosphate and 4.1 parts epoxy soya oil in a
Hensche~ Mixer. Beside the plasticizers, the common recipe
included in PVC was: 1.0 part 2-hydroxy-4-n-octoxy benzo-
phenone, as a stabilizer, 2.6 parts Advastab~ BC lO~A (liquid
barium cadmium zinc stabilizer for PVC), 1.5 parts Mark C
(alkyl aryl phosphate complex, a PVC stabilizer), 0.01 part
of a dispersion of oil violet one percent, a color hiding
agent) and 0.6 part triple pressed stearic acid (as a lubri-
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cant). The PVC and the copolymer were dissolved in tetra-
hydrofuran (THF) and 50/50 - THF/MEK respectively at 50 to
55C. using a low RPM air stirrer. Solution casting was
done by draw-down operation using a Gardne~ fiber casting
knife with micrometer and blade adjustments. Composite
films (total thicknessr~ 12 mils) made up of PVC ( ~ lO mils)
with a thin coating of copolymer (~J 2 mils) were made by a
solution casting technique in the following way:
First, a single vinyl film was cast on a clean
glass plate to give a film of approximately lO mils thick-
ness af-ter drying in the hood overnight. Second, the co-
polymer solution was cast on top of the dried single vinyl
film to give a film of about 2 mils thickness. Third, this
composite film was completely dried in the oven at 66C.
overnight. The polyvinyl chloride contains from 20 to 80
parts of plasticizer per hundred parts of polyvinyl chloride.
Alternately, the copolymers were compounded at
149C. with one part distearyl pentaerythrityl diphosphite,
1,5 parts Advastab BC 103A (liquid barium cadmium zinc sta-
bilizer), l part 2-hydroxy-4-n-octoxy benzophenone and 2
parts polyethylene and then ground through one-fourth inch
screen before they were coextruded with PVC (40 parts plas-
ticizer) to make composite films. me following were coex-
trusion conditions:
Pol~mer No. l Polymer No.2
Type: Copolymer PVC
State: Ground Pellets
Extruder No. lExtruder No~2
L/D Ratio: 20/l; Dia: l-1/2"15/1; Dia: 1-1/2"
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Extruder No. 1 Extruder No. 2
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Mfg: NRM NRM
Screen Pack:20/40/120/40 mesh ~
Screw Type:Low compression PE Type >
5Adaptor and Die
Composite Box:Research 2 layers
Die Width:12"; Die type: flat
Take-Off Equipment
Describe: Casting unit
Processing Conditions Extruder No. 1Extruder No. 2
Extr Throat, C.15.6 54.4 ~ -
Extr Zone-l, C. 149 168
Extr Zone-2, C. 210 191
Extr Gate, C. 209 196
Extr Load, amp/k2.4 1.9
Barrel, psi 1200 1100
Melt Temp., C. 179 179
Extr, rpm 12 72
Polymers Copolymer PVC
Composite Box, C. 199 ~ -
Die Adapt, C. 204
Die Zone-l, C. 201
Die Zone-2, C. 202
Cast Roll, C. 65.6
Chill Roll, C. R~To
Wind-up, fpm 7-1/2
Total Gauge, mils 12
Film Width, ins. 11
Film length, ft. 50
Aging studies indicated that both cast and coex-
truded composite films had excellent retention of tensile ` ;
strength and elongation. They exhibited no evidence of
discoloration, surface crazing, surface cracking and pitting ~-
after 7000 hours Xenon-arc Weatherometer, or 5000 hours
Fadeometer, or 300 hours Accelerometer exposure. The test - `
results on the laminate are shown in Table 1.
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Table 1
PHYSICAL TEST DATA ON AGED FILMS
Laminated Film *
Modulus Tensile Ultimate
Ph~sical Test at 100%~psi Strength,psi Elongation,%
Initial, unexposed1890** 2930 280
(1920)*** (2790) (220)
300 hrs. Accelerometer 1940 2850 300
Exposure(2270) (2360) (160)
5000 hrs. Fadeometer2500 2590 130
Exposure(2570) (2570) (120)
7000 hrs.Xenon-Arc2480 2950 280
Weatherometer exposure (-) (-) (-)
*Laminated films were composed of about 10-12 mils PVC and
about 2-4 mils copolymer (60/40-2-EHMA/AN). The copolymer
film in the laminate faced the light for exposure.
**Data for solution cast laminated films.
***Numbers within parentheses are data for coextruded lami-
nated films.
The physical test data in Table 1 indicates the
laminated films prepared by either casting or coextrusion
would be suitable for use in inflatable shelters, for exam-
ple, green houses.
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Table 2 shows physical properties of aged lamina-
ted cast films composed of PVC containing from lO to 50
parts plasticizers and a copolymer (60/40 2-EHMA/AN). The
laminates containing a plasticizer level of above 30 parts
such as Sample Nos. 3, 4 and 5, had excellent retention of
modulus at 100%, tensile strength and ultimate elongation
after 5000 hours Xenon-arc Weatherometer exposure.
While certain representative embodiments and de-
tails have been shown for the purpose of illustrating the
invention, it will be apparent to those skilled in this art
that various changes and modifications may be made therein
without departing from the spirit or scope of the invention.
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