Note: Descriptions are shown in the official language in which they were submitted.
-~S~'7'~
FL~ME RETAR~ANT BINDER FOR FLAMMABLE MATERIALS
BACKGROUND OF THE INVENTION
. . ~
Copolymers of vinyl halides, vinylidene halides and
various phorpho~us-containin~ vinyl monomers have been fre-
quently used as fire retardant agents for various flammable
materials, such as paper, cellulosic textlles and non-woven
fabrics. For light weight and flexible substrates, there is
a limit to how much polymer the substrates can pick up before
flexibility and a soft hand are lost. In these cases, there is
insufficient add-on to give reduced flammability. Inorganic
salts such as diammonium phosphate and ammonium sulfamate have
heretofore been used for this purpose; however, their water
solubility has rendered their flame retardant property non-
durable.
Thus, in accordance with the present teachings, a
flame retardant polymer latex binder composition is provided
which comprises (a) a polymer latex containing ~l) a bis(hydro- -
carbyl) vinyl phosphonate of the formula: :
X O
~ OR'
CH2 = C - P
~ OR,
wherein X is selected from the group consisting of hydrogen, ~:
halogen, cyano 9 phenyl, C1-Cl8 alkyl and
Il OR'
~ OR,
and each of R and R' are hydrocarbyl or substituted hydrocarbyl
having from 1 to 18 carbon atoms (2) a vinyl halide or vinylidene
halide, (3) a Cl to C20 alkyl ester of acrylic acid, and
optionally (4) a comonomer selected from the group consisting
of acrylicacid, methacrylic acid, amides of acrylic acid and
methacrylic acid, N-methylol derivati~es of the amides of
acrylic acid and methacrylic acid, and diacetone derivatives of
the amides of acrylic acid and methacrylic acid, (b) at least
~ ~ -2~
-
1~5~ 77
one phorphorus containing compound selected ~rom the group
consisting of a co-condensate of bist~ ~chloroethyl)vinyl phos-
phonate and dimethyl methyl phosphonate, a condensate of bis
(~ -chloroethyl)vinyl phosphonate~ tetrakisthydroxymethyl)
phosphonium chloride or hydroxide, ~l~hydroxymethyl-3-(dimethyl-
phosphoro)propionamide, tris(2,3-dibromopropyl phosphonate) and
water-insoluble ammonium polyphosphate, water-insoluble
ammonium salt of metaphosphoramidic acid, and mixtures thereo~,
said water-insoluble phosphorus compounds being characterized
by a water solubility of less than 25g/lOOcc at lO~C., (c) :
optionally urea, (d) an aminoplast selected from the group
consisting of melamine formaldehyde and urea formaldehyde, and
(e) optionally a phosphate plasticizer. -
It has now been found that excellent and non-after~
glowing durable flame retardant properties are imparted to :
flammable materials when they are treated with a composition
comprising the following components: (a) from about 20 to about
70 weight % of a polymer latex, (b) from about 3 to about 50
weight % of a phosphorus source, (c) from O to about 50 weight %
20 of urea, (d) a melamine formaldehyde or urea formaldehyde amino- ~- :
plast in about 10 to about SO weight ~, and (e) a phosphate ;; .
plasticizer in O to about 20 weight %. The components will now
be more fully described.
Component (aj is a polymer latex derived from at least
three monomers: (1) a bis(hydrocarbyl)vinyl phosphonate, (2) a
vinyl halide or vinylidene halide, (3) an alkyl acrylate, and
optionally (4) another derivative of acrylic or methacrylic
:
' '
-2a-
: . , . - , , ~: - ;:: ,
-,, ~ :
. - -
s~
acid as more fully described below.
The bis(hydrocarbyl)~inyl phosphonate has thestrurture:
X O
' " OR'~
C~2 = C - p OR ,/
wherein X is selected from ~he group consisting of hydrogen,
halogen, cyanot aryl such as phenyl, Cl-C18 alkyl and
OR'`~
~ OR _l
R and R' are hydrocarbyl and substituted hydrocarbyl groups
consisting essentially of hydrogen and carbon and containing
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 combine to form one single radical. `~;~
The use, in this disclosure, of the expression ~ ;
"hydrocarbyl" and "substituted hydrocarbyl groups" in the
definition of the suitable bis~hydrocarbyl)vinyl phosphonatss
given hereinabove~ref~rs to the radicals obtained upon the
remoYal of a hydrogen from a hydrocarbon or substituted hydro-
carbon group which may be either an aliphatic or aro~atic
group. These hydrocarbyl groups may be substituted with any
~on-interfering groups, i.e.~ with any group which does not
interfere with the polymerization of the bis(hydrocarbyl)vinyl
phosphonate. Such substituent groups include, for example,
chloro, bromo, fluoro, nitro, hydroxy, sulfone, ethoxyt methoxy,
nitrile, ether, ester and keto groups and the like.
, Illustrative of the aliphatic and aromatic groups
as are represented by R and R' in the structure of-the bis(hydro- -
carbyl~vinyl phosphonate givenhereinabove are alkyl groups, such
as methyl, ethyl, propyl, butyl, pentyl, hexyl, nonyl, and the
like; alkenyl groups such as pentenyl and hexenyl groups and
all of their respective isomers; cycloalkyl groups, such as
cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and the liks;
cycloalkenyl groups, such as cyclohexenyl, and the like; typical
aryl groups include phenyl, benzyl, phenethyl, tolyl, naphthyl,
and the like.
~epresentative of the above-defined bis(hydrocarbyl~
vinyl phosphonat~s are:
bis(~-chloroethyl)vinyl phosphonate;
bis(~-chloropropyl)vinyl phosphonate;
bis(~-chloroethyl) l-methylvinyl phosphonate;
bis(~-chloroethyl) l-cyanovinyl phosphonate;
bis(~chloroethyl) l-chlorovinyl phosphonate;
bis(~chloroethyl) l-phenylvinyl phosphonate;
dimethyl vinyl phosphonate;
diethyl vinyl phosphonate;
bis(~-chlorobutyl)vinyl phosphonate;
di-n-butyl vinyl phosphonate;
di-isobutyl vinyl phosphonate;
bis(2-chloroisopropyl) l-methylvinyl phosphonate;
diphenyl vinyl phosphonate; and
bis(2,3-dibromopropyl)vinyl phosphonate
From the group of bis(hydrocarbyl)vinyl phosphonate
monomers, it is preferred to employ bis(~-chloroethyl)vinyl
phosphonate in preparing the novel aqueous emulsion polymers
of this invention since the latter monomer is a commercially n
available material and lower in cost than any of the other
bis(hydrocarbyl)vinyl phosphonates.
The vinyl hallde or vinylidene halide may be, for
example, vinyl chloride, vinyl bromide, vinyl fluoride, vinyli-
dene chloride, vinylidene bromide, vinylidene chlorobromide
or vinylidene fluoride. Preferred are vinyl chloride and
vinylidene chloride.
~ The alkyl acrylate may be any Cl to C20 alkyl ester
of acrylic acid, such as methyl acrylate, ethyl acrylate, n- .-
butyl acrylate, sec.-butyl acrylate, 2-ethylhexyl acrylate,
,
0~7~
lauryl acrylate or mixture thereoE. Preferred monomers are the
C4-C8 alkyl acrylates such as n-butyl acrylate and 2-ethylhexyl
acrylate.
The fourth monomer is another derivative of acrylic
acid or a derivative of methacrylic acid, or may be the respec~
tive acids themselves. Among the derivatives are the amides
and t.he N-mathylol and diacetone derivatives of the æmides. `:
Preferred are N-methylol acrylamide, acrylamide, acrylic acid ~ :~
and methacrylic acid. s
The proportions of the various monomers forming
component (a) are as follows: from about 10 to a~out 75 weight
% of bis(h~drocarbyl)vinyl phosphonate, from about 20 to about
85 weight % of vinyl halide or vinylidene halide, from a~cut
5 to about 35 weight.% of alkyl acrylate, and from 0 to
about 10 weight ~ of the fourth comonomer~
Specific latex polymers for component ~a) include .
the following: ;
: (1) a terpolymer of 30 parts by weight of vinylidene
chloride, 20 parts by weight o~ n-bu~yl ae~rylate and 5O parts by
weight of bis(beta-chloroethyl)vinyl phosphonate;
t2) a terpolymer containing 15 parts by weight o~
di-n-butyl vinyl phosphonate, 20 parts by weight of di-2-ethyl-
hexyl acrylate and 65 parts by weight of vinylidene chloride; :
(3) a polymer containing 50 parts of bis(beta-
chloroethyl)vinyl phosphonate, 25 parts of vinylidene chloride,
- 20 parts of 2-ethylhexyl acrylate~ and 5 parts of N-methylol
acrylamide;
~ 4) a polymer containing 45 parts by weight of
vinylidene chloride, 35 parts by weight of bis(beta-chloroethyl)
vinyl phosphonate, 15 parts by weight of n-butyl acrylate and
~5t~'7~
5 parts by weight of N-methylol acrylamide; and
~ 5) a polymer containing 30 parts by weight of
bis(beta-chloroethyl)vinyl phosphonate, 5 parts by weight of
propylene, 60 parts by weight of vinyl chloride and 5 parts by
weight of N-methylol acryl~mide.
The polymers of the presen~ invention can be prepared
by means of free radical initiated e!mulsion polymerization
techniques well known to those skilled in the art. In these
procedures r the various monomers and catalysts are emulsiied,
in water, by means of one or more surface-active emulsifiers
whereupon the polymerization reaction is then initiated.
Suitable water soluble, free radical initiating catalysts for
use in preparing the copolymer latices of this invention include
sodium,potassium and ammonium persulfate and hydrogen peroxide
or one may use a redox system such, for example, as a mixture
of a persulfate with an al~ali metal bisulfite, thiosulfate or -
hydrosulfite. These catalysts should be present in a concentra-
tion of from about 0.05 to 5.0%, by weight, of the total
monomer charge. With respect to the emulsiier or surfactant,
it is possible to utilize one or more anionic, cationic, or non-
ionic emulsifiers such, for example, as the alkyl carboxylic ~ ;
acid salts; the alkyl sulfate, sulfonate, phosphate, or sul~o-
succinamate salts; the alkyl aryl ether alcohols, and the
alkyl aryl polyether sulfate salts. The selected emulsifier
or emulsifiers should be present in effective concentration of
from about 0.3 to 6.0%, hy weight, of the total monomex charge.
In addition, a protective colloid such 25 polyvinyl alcohol,
polyvinyl pyrrolidone, methyl cellulose or gelatin can also,
if desired, be present in the recipe in an effective concentra-
tion of from about 0.03 to 6.0%, by weight, of the total
~3~;'7'7 ~-
monomer charge. Alternatively, the protective colloid may be
introduced into the copolymer latex subsequent to its prepara-
tion. When post-added in this ma~ner, the protective colloid
should be present in a concentration of from about 0.03 to 6.o~,
by weight, of the total resin solids. In any event, the pre-
sence of the protective colloid serves to enhance the mechanical
stability of the emulsion.
The actual polymerization raaction will ordinarily
be conducted at a temperature of from about 0 to 100C. for a
period of from about 1 to 24 hoursJ depending upon such factors
as the particular monomer, catalysts, surfactants and polymeriza-
tion apparatus that is being utilized. The latices resulting
from this polymerization process will ordinarily have a resin
solids content of from about 5 to 7~, by weight, wherein the
particles have a diameter which ranges in size from about 0.03
to 3.0 microns.
Component (b) is a source of phosphorus selected from
the following: (i) a co-condensate of bis(~3-chloroethyl)vinyl
phosphonate and dimethyl metbyl phosphonate or a condensate of
bis(~3- chloroethyljvinyl phosphonate, (ii) tetrakis (hydroxymethyl)
phosphoni~m halide or hydroxide, (iii) (N-'nydroxymethyl-3-dimethyl-
phosphoro) propionamide, (iv) tris(2,3-dibromopropyl)phosphate3
(v) water-insoluble ammonium polyphosphate, and (vi) water-
insoluble ammonium salt of metaphosphoroamidic acid.
The co~condensate of bis(~ -chloroethyl)vinyl phosphonate
and dimethyl methyl phosphonate or the condensate of vinyl
phosphonate is prepared by heating the mixtures of the two components
or bis(f3-chloroethyl)vinyl phosphonate alone at about 100 to
250C. with a basic catalyst for about 2 to 12 hours resulting in a
fluid liquid. A mixture of ethylene dichloride and methyl chloride
or ethylene dichloride is generated as a by-product.
: - . - ,. -
. - . . : , . . .
~05~'77
Tetrakis(hydroxymethyl) phosphonium chloride or
hydroxide, also Xnown as ~IPC or THPOH has the structure:
(HOCH2)~PCl or (H()CH2)~PO~
and is sold by Hooker Chemical Corporation, a division of
Occidental Petroleum Corporation.
N-hydroxymethyl-3-(dimethylphosphoro)propionamide
has the structure:
O
(CH30)2-P-CH2CH2C-NHCH20H
and is sold under the trademark PYROVATEX CP by Ciba-Geigy
Corporation.
,
Tris(2,3-dibromopropyl phosphate) has the structure:
(cH2BrcHBrcH2o)3p=o
and is sold under the trademark FYROL HB32 by Stauffsr Chemical
Company.
Water-insoluble ammonium polyphosphate is made by heating ~-
,
ammonium phosphate with urea, and is known commercially as
PHOSCHEK P30 sold by Monsanto Company.
~he water-insoluble ammonium salt of metaphosphoramidicacid ~ ;
is made by the reaction of ammonia with phosphorus pentoxide. -
The term "water-insoluble" is meant to denoteij~that
:' , :
the solubility of the phosphorus compound in water is less than
.,
25g/lOOcc at 10C. or less than 75g/lOOcc at 70C.
Component (c), whose presence is optional, is urea. ` ;
Component (d) is a melamine formaldehyde or urea ;
formaldehyde aminoplast. Typical aminoplasts include such `
melamine/formaldehyde resins as AEROTEX M-3, AEROTEX 23 Special,
AEROTEX MW and AEROTEX ResLn 44, all of said resins being
available from American Cyanamid Company.
~ 7'~
Componsnt (e), whose presence is also optional,
is a phosphate plasticizer. To illustrate, it can be alkyl
acid phosphates, i.e., methyl acid phosphate, butyl acid
phosphate; trialkyl phosphates, i.e., trioctyl phosphate, tri-
dodecyl phosphate; triaryl phosphates, i.e., tricresyl phcsphate,cresyl diphenyl phosphate, i.e., octyl diphenyl phosphate, hutyl
dicresyl phosphate, and the like.
The flammable materials treated by the compositions
of this invention include cellulose, regenerated cellulose ~uch
as rayon cellulose esters and mixed esters such as, for exampleO
cellulose nitra.te, cellulose acetate, cellulose acetate-butyrate, ;
cellulose acetate propionate and cellulose ethers such as, for
example, ethyl cellulose and combinations thereof. In addition, ~ -
tha~e flammable materials can be blended with polyesters such
as polyethylene terephthalate, poly(cyclohexane-1,4-dimethylene)
terephthalate; polyamides; mineral fibers such as asbestos and
glass fibers. The flammable m~terials can be in the form of
paper, woven textlle fabrics or non-woven fabxics.
The binder compositions are applied to the flammable
material by methods well known in the art, such as, for exa~ple,
by immersion in a.bath containing the binder t or by knife- .
~oating.
The practice of this invention is shown by the follow-
ing examples, which are included here for purposes of illus~ra- .
25 tion only and are not intended as lLmitations. .:
. EXAMPLE 1
A polymer latex composition was prepared having the
following constituents: 48% bis(~-chloroethyl)vinyl phosphonate,
29~ vinylidene chloride, 19% n-butyl acrylate, and 4~ N-methylol
acrylamide, all percentages being by weight. The composition
. ~ ,. .. . .. .
~50~'7'/'
was prepared as an emulsion of 50% of solid content.
A pad bath was then charged with:
lOOg - above-described po]ymer latex t50% active)
lOg - co-condensate of bis(~-chloroethyl)vinyl
phosphonate and dimethyl methyl phosphonate
tlOO% active)
25g - melamine-formaldehyde condensate, AEROTEX M-3,
American Cyanamid Company (50% active)
20g - urea
0-8g - ~NH4)2S28 ~ -
50g ~ ~2 ~ ~`
A sample of 1 1/2 ounce/square yard weight commercial
non-woven celIulosi~ is employed as the flammable substrate. -
The mixture in the pad bath was stirred to uniformity, and
samples of the cellulosic cloth immersed therein. The exce s
liquid was squeezed out and the sample cured at 170C.for 8
minutes. The dried samples were then burned according to ~TCC
method 34-1966. The results of the burn test are as follows: ;
% Add On Char Lenyth After Test
.. :: -
20 50 3" - non-burning
4 1/2" - non-burning
5" - non-burning
6" - non-burning
6 1/~" - non-burning ;~
0 burn entire length
The samples were also washed for 5 minutes at 30C.
in water to test retention of fire retardant properties. The
fire retardant propeFties remained.
--10-- ~
-
~I~S~7'7
EX~MP_LE 2
In this example, the flammable substrate i5 a cloth
of 65/35 blend of polyester/rayon. Th~ same pad bath and the
procedure as employed in Example 1 gave a flame retardant fabric,
the flame retardant property of whic:h was not lost by washing.
EXANPLES 3-5
In these examples, the co-condensate of bis(~-chloro-
ethyl)vinyl phosphonate and dimethyl methyl phosphonate in the
formulation of Example 1, was replaced by an equal weight of
PYROVATEX CP, THPOH, PHOSCHECX P30, respectively. The resulting
baths imparted durable flame retardant properties to textile
fabrics and non-woven fabrics, which if not treated with the
latex will burn the entire length by the test described in
Example 1.
. .
,, ~. '.,, . ~
