Note: Descriptions are shown in the official language in which they were submitted.
Technical Description of the Invention
A method for forming plastic foam laminatPs is described
in U.S. Patent No. 2,964,799 to P. E. Roggi et al. wherein a
vinyl chloride-vi~yl acetate copolymer mass containing a blow-
ing agent can be calendered at 150C.-185C. to fuse the resin
and form a thin film on a fabric substrate, and this laminate
can then be heated to 190C.-255C. whereby the film expands
freely without disruption to form a blown sheet having a contin-
uous surface. That patent mentions that use of resins which cal-
ender below the 160-185C. temperature range will give a poor
foam quality in the final product.
This invention is a method for forming a foam by utiliz-
ing a resin formulation which calenders below the range set
forth in the Roggi et al. patent, the foam formed thereby,
and the resin formulation which is to be used in forming the foam.
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1l~78~)9~ ,
Thus, in accordance with the present teachings, a
method is provided for making a plastic film laminate which
comprises forming a laminate of a plastic film on a base, the
film comprising a vinyl chloride-vinyl acetate-dis(hydro-
carbyl) vinylphosphonate suspension copolymer and a blowing
agent.
In accordance with a further embodiment a plastic
foam laminate is provided which comprises a base and a plastic
foam attached to the base, the foam comprising a suspension co-
polymer of vinyl chloride, vinyl acetate and bis(hydrocarbyl) vinyl-
phosphonate.
By a further embodiment a plastic laminate is
provided which comprises a base, a plastic film attached to
the base, the film comprising a suspension copolymer of vinyl
chloride, vinyl acetate and bis(hydrocarbyl) vinylphosphonate
and blowing agent.
Thus, in accordance with the present teachings, a
suspen~ion polymer is provided which comprises from about 80% to
about 90% by weight vinyl chloride, from about 2~ to about 15% by
weight vinyl acetate, and from about 2% to about 15% by weight of
a bis(hydrocarbyl) vinylphosphonate.
The first step in the process of forming the laminate
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1078Q96 CIP of C-4078
is the milling of a solid thermoplastic suspension copolymer
which comprises from about 80~ to about 90~ by weight vinyl
chloride, about 2~ to about 15~ by weight vinyl acetate, and
about 2~ to about 15~ of a bis (hydrocarbyl) vinylphosphonate
with an amount of blowing agent which is effective to foam the
plastic film in the later heating step~which will be described
in greater detail below, and, preferably, with from about 25~
to about 50~ by weight of plasticizer, based on the weight of
the resin composition. The amount of plasticizer that is used
allows for production of an expandable melt at the heating
temperature used in the process. In addition to these components,
the composition can also contain conventional amounts of the
heat stabilizers, pigments, fillers, colorants or other
functional additives known to persons of ordinary skill in the
art.
If desired, the resin cmmposition can be easily flame
retarded by using phosphate esters, e.g., tricresyl phosphate,
2,3-dibromopropyl phosphate, etc., either alone or in combin-
ation with antimony trioxide, hydrated alumina or any other
2Q flame retardant generally used in the plastics industry in
amounts conventionally used in flame retarding polyvinyl
chloride, e.g., about 2~ to about lo~ of the composition.
The term "bis (hydrocarbyl~ vinylphosphonate" as used
herein is intended to encompass vinylphosphonates having the
structure:
X O
r ~ OR~
CH2 = C- P~
~ OR~
wherein X is selected from the group consisting of hydrogen,
- 1078096 CIP of C-4o78
halogen, cyano, aryl, such as phenyl, Cl-C18 alkyl and
o
p ,,,OR
OR~
wherein R and R' are hydrocarbyl and substituted hydrocarbyl
groups consisting essentially of hydrogen and carbon and con-
taining up to about 18 carbon atoms inclusive with the proviso
that R and R' may be the same, different or conjoint, i.e., R
~ and R' may form one single radical.
The use in this disclosure of the expression "hydro-
carbyl" and "substituted hydrocarbyl" groups refers to the rad-
~cals obtained upon the removal of a hydrogen from a hydrocarbon
or substituted hydrocarbon group which may be either an aliphat-
ic or aromatic group. These hydrocarbyl groups may be substi-
tuted with any non-interfering groups, i.e., with any group
which toes not ~nterfere wlth the polymerization of the bis-
thydrocarbyl) vinylphosphonate. Such sub~tituent groups in-
clude, for example, chloro, bromo, fluoro, nitro, hydroxy, sul-
ZO fone, ethoxy, methoxy, nitrile, ether, ester and keto groups and
the like.
Illustrative of such groups as are represented by R and
R' are alkyl or alkenyl groups, such as methyl, ethyl, propyl,
butyl, pentyl, hexyl, nonyl, pentenyl, and hexenyl groups and
all of their respective isomers; cycloalkyl or cycloalkenyl
groups, such as cyclopropyl, cyclobutyl, cyclophenyl, cyclohexyl
and cyclohexenyl groups and the like; while typical aryl groups
represented by R and R' include phenyl, benzyl, phenethyl, tolyl
and napthyl groups and the like.
1~ 7809 6 C~P of C-4078
Representative of the above depicted bis(hydrocarbyl)
vinylphosphonates which may be used in preparing the fire re-
tardant vinyl chloride copolymers of this invention are:
Bis~beta-chloroethyl) vinylphosphonate;
Bis(beta-chloropropyl~ vinylphosphonate;
Bis(beta-chloroethyl) l-methylvinylphosphonate;
Bis(beta-chloroethyl) l-cyanovinylphosphonate;
Bis(beta-chloroethyl~ l-chlorovinylphosphonate;
Bis(beta-chloroethyl) l-phenylvinylphosphonate;
Dimethyl vinylphosphonate;
Diethyl vinylphosphonate;
Bis(omega-chlorobutyl) vinylphosphonate;
Di-n-butyl vinylphosphonate
Di-isobutyl vinylphosphonate;
Bis(2-chloroisopropyl) l-methylvinylphosphonate;
Diphenyl vinylphosphonate; and
Bis(2,3-dibromopropyl) vinylphosphonate.
It is, however, to be emphasized that it is preferred
to employ bis(beta-chloroethyl) vinylphosphonate in preparing
the copolymers of this invention since the latter monomer is a
commercially available material and is lower in cost than any
of the other above listed bis(hydrocarbyl) vinylphosphonates.
The preferred composition of the suspension copolymer
f this invention is about 85~ to about 87~ vinyl chloride, about
3~ toabout 8~ vinyl acetate and about 5~ to about 7~ bis (beta-
chloroethyl) vinylphGsphonate. Any of the copolymers suitable
for use in the present invention are formed by subjecting the
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1C~78096
foregoing monomers to conventional suspension polymerization
procedures which are well known to persons of ordinary skill in
the art. Typically, such procedures entail the use of from
about o.o510 to about 1~, by weight of the monomers, of a sus-
pending agent, e.g., methyl cellulose, hydroxyethyl cellulose,
hydroxypropyl cellulose, carboxymethyl cellulose, talc, clay,
polyvinyl alcohol, gelatine or the like, with from about 0.2~
to about l.o~, by weight of the monomers, of a monomer-soluble
initiator, e.g., azobisisobutyronitrile, lauroyl peroxide,
lo benzoyl peroxide or isopropylperoxy dicarbonate, in an aqueous
medium containing said monomers. The polymerization is con-
ducted at about 45C. to about 75C. for a period of about 2 to
12 hours with agitation being applied throughout ~he reaction.
The relative viscosity of the copolymers (1~ in cyclohexanone
at 25C.) should range from about 1.7 to about 2.7.
The blowing agent which is used is present in an effec-
tive amount, e.g., preferably ranging from about 1~ to about 20
by weight of the copolymer, most preferably from about 7.5% to
about lo~ by weight, and is one which decomposes at a tempera-
ture of from about 140 to about 160C. The preferred blowing
agent is 4,4' oxybis(benzenesulfonyl hydrazide) which is avail-
able from Uniroyal Chemical Div., under the trademark "Celogen
OT".
The milling may be accomplished in an internal mixer,
open roll mill, or both, at a temperature which is less than
that required to decompose the blowing agent. The milled com-
position containing the copolymer is a unitary, solid mass,
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1~78096
rather than particulate, and the composition is non-flowing
and self-supporting at ordinary temperatures. The amount of
plasticizer used should be from about 25 to about 50~, by
weight, based on the weight of copolymer. Any conventional
polyvinyl chloride plasticizer can be used. Conventional
stabilizers, colorants, antioxidants, lubricants and other
additives can also be included in conventional amounts in the
composition.
The next step of the process involves the calendering
of the milled copolymer-containing composition onto a suitable
base. Flexible bases, such as a fabric base, are preferred.
The calendering is accomplished by using a conventional cal-
end~r, e.g., a three or four roll calender, at a temperature
sufficiently elevated to bring about substantial fusion of
the resin so that a coherent, uniform film , is formed. The
temperature should be about lloC. to about 125C., preferably
about 115 to about 125C. These temperatures are insufEicient
to cause decomposition of the blowing agent contained in the
composition. The calendering step forms a film having a
thickness of from about lO to about 120 mils on the base. This
product can be wound up into a roll, or transported or stored
in any other convenient form, for an indefinite period of time.
Alter~atively, the copolymer composition may first be
calendered into a cohesive, unsupported film or sheet which is
then combined with the flexible base to form a laminated con-
struction by the use of an adhesive or by ~he application of
heat and pressure. Typical adhesives are plastisols, latexes,
solutions, dispersions or hot melts which are suitably form-
~ 809 6 CIP of C-4078
ulated as is well known to those of ordinary skill in ehe art.
The adhesive may be applied to the side to be laminated on
either the flexi~e base or the unsupported film or sheet. The
two components of the construction are then contacte~ with each
other, and the adhesive is allowed to dry or cure thereby form-
ing a permanently bonded laminate. If practical, the copolymer
film or sheet may be placed on the flexible substrate and lam-
inated thereto by the use of heat and pressure.
After the calendered base and copoly,~er composition is
formed, it is then heated to a temperature of from about 140 C~
to about 160C. for a period of from about 5 to about 15 min.
to decompose the blowing agent and thereby foam the compostion
containing the copolymer and blowing agents.
The following Examples illustrate the present invention:
EXAMPLE 1
This illustrates formation of a suspension copolymer
suitable for use in forming the laminates of the present in-
vention.
Deionized water (52 lbsq 13 oz.) and 32 grams of Metho-
cel suspending agent solution were charged into a lo gallon re-
actor. Vinyl acetate (2 lbs.~ and bis (beta-chloroethyl) vinyl-
phosphonate (1 lb. 11 oz.) were added followed by 5 grams of
azobisisobutyronitrile catal~st (Vazo-52). The manhole of the
reactor was closed, vacuum was twice applied, and the reactor
was purged with nitrogen. The vinyl chloride monomer (24 lbs
8 oz.) was then charged into the reactor, and the mixture was
stirred at 496 rpm. for about 30 minutes. The reactor was heated
to 52C. and was maintained at this temperature until th~e pres-
sure dropped by 30 psi from the levels noted while the reaction
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was initiated. At this point lo grams of 2,6-di-tert-butyl-4-
methylphenol (IonoL) was added. The product was recovered by
centrifuging in the presence of filter paper and was dried in
an oven dryer.
EXAMPLE 2
A composition was formed by milling the ingredients
listed in the Table for seven minutes (front roll: 245F., 30
feet/min.; back roll: 250F., 42 feet/min.):
AMOUNT
lo INGREDIENTS (Parts by Weight)
87~ vinyl chloride: 7
vinyl acetate: 6~ bis
(beta-chloroethyl)vinyl-
phosphonate copolymer* loo
Dioctyl Phthalate 40
Butyl Benzyl Phthalate 15
Epoxidized Soya~fan oil 5
Stabilizer (ABC~) 3
Filler (CaC03) lo
Pigment (TiO2) , 2
Lubricant (Stearic Acid) 2.5
Celogen-OT (4,4'-oxybis
benzene sulfonyl hydrazide~ 8
*Relative visc08ity: 2.17,made as described in Example 1.
2S EXAMPLE 3
Another formulation was milled according to Example 2 and
contained the following:
AMOUNT
INGREDIENTS (Parts By Weight)
Copolymer of Example 1 loo
Dioctyl Phthalate 60
Butyl Benzyl Phthalate 20
Epoxidized Soyabean Oil 5
Stabilizer (ABC-2) 3
Filler (CaC03) lo
Pigment (TiO2) 2
Lubricant (Stearic Acid) 2.5
Celogen-OT(4,4'-oxybis benzene
sulfonyl hydrazide) 8
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~078096 CIP of C-4o78
EXAMPLES 4-6
These examples show use of polymer compositions falling out-
side the scope of the present invention and use of a blowing
agent which does not decompose in the range of 140C,-160C.
All milling conditions are the same as in Example 1.
EXAMPLE 4
AMOUNT
INGREDIENTS ~Parts By Weight)
87~ vinyl chloride: 7
vinyl acetate: 6~ bis
(beta-chloroethyl)vinyl-
phosphonate copolymer* 100
Dioctyl Phthalate 40
Butyl Benzyl Phthalate 15
Epoxidized Soyabean Oil 5
Stabilizer (ABC-2) 3
Filler (CaC03) lo
Pigment (TiO2) 2
Lubriant (Stearic Acid~ 2.5
R-80~(Diisopropyl Azodiformate) 8
~Relative Vi8cosity: 2.17
EXAMPLE 5
AMOUNT
INGREDIENTS (Parts By Weight~
85.5~ vinyl chloride: 10.7
(beta-chloroethyl~ vinyl-
phosphonate: 3.8~ propylene* loo
Dioctyl Phthalate 25
Butyl benzyl phthalate 15
3 Epoxidized Soyabean Oil 5
Stabilizer (ABC-2) 3
Filler (CaC03) lo
Pigment (Tio23 2
Lubricant (Stearic Acid) 2.5
Celogen-OT (4,4'-oxybis
benzenesulfonyl hydrazide) 8
~This copolymer at 60 parts per hundred plasticizer was too
soft and could not be milled.
1~7809~ CIP of C-4078
EXAMPLE 6
AMOUNT
INGREDIENTS (Parts By Weight)
90% vinyl chloride: lo~ bis
(beta-chloroethyl) vinyl-
phosphonate* loO
Dioctyl Phthalate 40
Butyl benzyl phthalate 15
Epoxidized Soyabean Oil 5
lo Stabilizer (ABC-2) 3
Filler (CaC03) lO
Pigment (TiO2) 2
Lubricant (Stearic acid) 2.5
Celogen-OT(4,4'oxybis benzene-
sulfonyl hydrazide) 8
~Relative Viscosity: 2.5
EXAMPLE 7
Each of the five compositions in Examples 2-6 was lam-
inated onto a fabric in a two roll mill. The laminated film was
expanded by heating in a circulatory oven for five minutes at
320F. The table sets forth the pre-expansion and post ex-
pansion characteristics.
PRE-EXPANSION POST-EXPANSION BLOW-UP
THICKNESS THICKNESS RATE* CELL
COMPOSITION(MILS) (MILS) (~) QUALITY
Ex. 2 80 205 300 E'ine &
Uniform
Ex. 3 63 280 600 Fine ~
Uniform
Ex. 4 74 135 210 Coarse
Ex. 5 99 179 200 Coarse
Ex. 6 98 187 210 Coarse
~Corrected for a fabric thickness of 20 mil.
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