Note: Descriptions are shown in the official language in which they were submitted.
~ 04:~Q~
BACKGROUND OF THE INVENTION
Prior art disclosing polymerizable blocked isocyan-
ates is as follows: U.S. Patent Nos. 2,483,194, 2,556,437,
2,882,260; 3,261,817; 3,299,oo7; 3,542,739 and 3,694,146, and
British Patent 1,288,225. Other relevant art is disclosed in -
U.S. Patent Nos. 3,519,478, 3,694,389 and 3,711,571.
The novel ethylenically unsaturated blocked aromatic
diisocyanates can be distinguished from other known polymeriz-
able isocyanates by their ease of polymerization and copolymer-
ization with vinylidene monomers, particularly in emulsion
polymerization systems. The prepared polymers are quite stable
to hydrolysis and can be stored in latex iorm.
Interpolymers o~ the novel diisocyanates with acrylate
monomers have particular utility as binders for non-woven fibers
such as paper, cotton, synthetic ~ibers, and the like. The
fibers are coated or impregnated with the interpolymers which :
can then be cured at temperatures as low as 80C. and under
acldlc, neutral, or basic pH conditions. This is in contrast ~;~
.
to the known acrylic or nitrile latex binders which require
~20 highly acidic (pH o~ about 2) conditlons to exhibit a strong
fast cure at low temperatures. The hlghly acidic environment
is undesirable a~ it can degrade some fibers, especially
; cellulose-type fibers, it can interfere with e~forts to
thlcken the latex ~or more convenient use, and it can cause
corrosion
S~ARY OF THE INVENTION
Ethylenically unsaturated blocked aromatic diiso-
cyanates are prepared having the formula
R O O
", " ., ' :.''
CH2-C-A-OC-NH-B-NH-C-X
~ ~where~R~is hydrogen or a methyl or ethyl radical, A is a
o~ .
carbonyloxyalkylene radical containing 2 to about 8 carbon atoms ~ -
~or an aralkylene radical, B is a bivalent aromatic radical
selected from the group consisting of arylene, napt~alene
and the s~ructure
R ~
n n
where Y is O, S or--~CH2~ , where n = O to 3, and X is the
radical fragment remaining by the removal of a hydrogen atom
from the nitrogen atom of an oxime selected from the group
consisting of acetoxime, methylethyl ketoxime, methylpropyl -
ketoxime, methylisobutyl ketoxime, ethylhexyl ketoxime, cyclo-
hexanone oxime, benzophenone oxime, benzoaldoxime; benzimi-
dazole, a pyrazole, a pyrazole selected from the group consist-
ing of pyrazole,3-methyl pyrazole, 3,5-dimethyl pyrazone; and
a benzotriazole selected from the group consisting of benzo-
triazole, 5-methylbenzotriazole, 6-ethylbenzotriazole, 5-
chlorobenzotriazole and 5-nitrobenzotriazole.
The defined diisocyanates are readily polymerized,
especially via emulsion polymerization techni~ues, to form
polymers of from about 0.1 percent to 100 percent by weight
(i.e., homopolymers) of the diisocyanate and up to 99~9
. .
percent by weight of a copolymerizable vinylidene monomer.
DETAILED DESCRIPTION OF THE INVENTIO~
The ethylenically unsaturated blocked aromatic di-
isocyanates have the formula
R O O
11 11 '
CH2=C-A-OC-N~I-B-NH-C-X . ~: '
wherein R is hydrogen or a methyl or ethyl radical, A is either -
a carbonyoxyalkylene radical containing 2 to about 8 carbon atom,s
or an aralkylene radical containing 7 to about 12 carbon atoms,
~ -3-
,.
. :
B is a bivalent aromatic radical selected from the group consist-
ing of arylene, napthalene, and the structure
. . .
~~Y~O~
R'n n
: ~ , . ., ., ~ . .
:' ' ' '
,
. ' .,, '.
" ':
'.'; ~' '
''' ' ' ~ '
" ~::: .
' :
-3a- .
1C34~
where R is defined as above~ Y is 0, S, or -~-CH2-~-n , n = O
to 3, and X is the radical fragment remaining after a hydrogen
atom is removed from the nitrogen atom of an oxime,benzimi~ole,
pyrazole, benzotriazole, caprolactam, thiocaprolactam, or p-
nitroaniline. The aromatic rings in A and/or B can be furthersubstituted with 1 to 4 carbon atom alkyl radicals. More
preferredly, R is hydrogen or a methyl radical, B is selected
from the group consisting of phenylene, tolylene, naphthalene,
and the defined structure where Y is ~ CH2-~-n group and
n = O to 1.
Examples of the unsaturated blocked aromatic diiso-
cyanates are:
When ~rAI~ is a carbonyloxyalkylene radical:
O '
H O O NH-CO-N=C/ 3
~ t~
CH2-C-CO-(CH2)2-OC-NH ~ CH3 C2H5
.
H O O CH3 0
. CH2=C-CO-(CH2)3-OC-NH ~ NH-cO-N=c~c H
CH3
O
CH3 O O NH_co_N=c~ 2 5
CH2=C--CO- (CH2)2-OC-NH~CH3 C6H13 ~ '
,
:
H O O O
CH2=C- CO- ( CH2 ) 4-OC-NH~II- C-N~
CH3 CH3
..~ .
_ 4 _
- . . - . . - . - .
, . . -
10~
CH3 0 0 O
CH2=C - CO-(CH2)6-OC-NH ~ NH-CO-N-C~ 3
H O O O
CH2=C-CO-(CH2)-0C-NH-C2H4 ~ C2H4-NH-CO-N-C~ 3
,CH3 ~t ~ <C2H5
CH2=C- CO-(CH2)3-0C-NH ~ . :
NH-C-N ~ ~ ~
' ' ' ' . '
: , , ,
C,2H5 ,0, ,ol CH3 CH3 ~N ~ CH3
CH2=C- C-(CH2)4-C-NH ~ CH2 ~ H C N ~ : ,
. :
::,
,.
H O O O . :
~ CH2-C-CO-(CH2)2-0C-NH ~ CH2-NH-C-NH ~ N02
~ .
.:
O
H O O ~NH-CO-N=C~ 3
-CO-(CH2)4_0C_NH ~ Cl 3 7 ~.
C,H3 ,,~ i ~ 3 ~~ ~
CH2~C - C-(CH2)2-C-NH ~ b H3
< O ~ C2H5
CH3
-
`.:. :: '
5 -
104i~
O O CH O ~N
, 3 " " ~ 3
CH2=C C0-'CH2'5-OC-NH ~ CH-NH-C-N
O ~
~ ' ,N- N
CH O O NH-C-N~
~ 3 t~ t~
CH2=C CO-(CH2)2-Oc-NH ~ 3 ~ H
CH
H O O ~H-CO-N=C
CH2SC-CO-(CH2)2-OC-NH ~ CH3 2 5
O : ,:
" CH
CH3 O O NH-CO-N=C
CH2=C CO-(CH2)2-OC-NH ~ CH3 C4Hg
.
, . ~'
CH O O NH-C-N _
3 11 ~ ~
CH?-C - CO-(CH2)2-OC-NH ~ 3 ~ 3
~.
O
; CH3 ,, tt ~ H-CO-N=C~ 3
CH2=C CO-(CH2)2-OC-NH ~ CH3 '.
.
. .
C,2H5 ,O, o CH3
' CH2=C _ CO-(CH2)3-OC-~H ~ NH-C-N ~ :
.~
~ ' '
: .:
- .
.:
- : r
lQ~O~L
CH O O
, 3 "
CH2=C CO- (CH2)2-OC-NH~CH3,0, ~ ,~,
S~ :
t, ~ .
,CH3 i~ ~ H-C-N\
CH2-C CO-CH2CH2-OC- ~ H3 ~ . :
. ~ . . .
' - ...
H O O O
CH2-C-CO-(CH2)4-0-NH ~ CH2 ~ O `~
,
CH O O Br ~-
CH2=C GO-(CH2)6-OC-NH ~
B NH - C-N-C~ 3 .
C2H5 ., :' " '
CH O O
t 3
CH2=C CO-(CH2)2-0C-NH ~ CH3 ~~ /N CH3 .
NH- C-N
H O O CH3 0
=C-CO-(CH2)4-0C-NH ~ NH C N ~N `
3 ~
~ -
. ~
~ . - 7 -
.
CH O O CH3 CH3 O
3 1 ~r ~ ~-- < /=~N
CH2=C--- CO- (CH2)2-0C-NH~cH2~NH-C-N~
~)
/ <CH3 O / N
H O ~ O j~NH-C~
CH2=C-CO- (CH2)3-0c-NH~ ~ N2
CH3 ;
CH3 0 I N= N
CH2~C - CO-(CH2)2-OC-NH~ NH-C-N~ ¦
<~ ... ~ . .,
C2H
.
- ,o, ~ . .
CH O O NH-C NH
~ 3 1 r--~
CH2=C CO- ( CH2 ) 2-OC-NH~ 3 [~
NO . .
5 and ~he like.
When l'A" i~ an arylene radical: :
o
H O H-CO-N=C~ 3
CH2=c~cH2-oc-NH~cH3 3
~ .
H ~ 0 ~ It /N1 ~-
H2=C~ CH2-OC-NH ~ N~-C-N\=J
.
.
10~0~
CH^ O
CH2=c ~ ~ N -C-N=C~ 3 ; ~
. .
,CH3 ,, .~ = N
CH2=C ~ ~ NH-C-N ~ CH
CH2-OC-NH ~ CH3 ~ 3
' ,': ~'- ' '
H O CH3~t - -~ ~ CH3 0 ~ .
CH2=C ~ -CH2-OC-NH ~ CH2 ~ NH-C-
: 3
'~
-C-~
CH2---O ~ CH2-00-NH ~ H3 (~--
O CH3 O
H CH2-OC-NH ~ NH-CO-N- C H
CH2-C~ CH3
'
. ~ N2
CH2-oC-NH~CH3
O
.
' ' ~
.: '
- . : .
~ _ g _ '':
1(~4.1l~
CH2=C ~ CH2-OC-NH ~ CH2 ~ NH-C-N
H O ,NH-CO-N-C ~ : .
CH2-C ~ CH2-OC-NH ~ CH3 CH3 C2H5
and the like.
The ethylenically unsaturated blocked aromatic diiso-
cyanates are prepared in a two-step process wherein first a
hydroxy-containing vinylidene monomer is reacted with an aro-
matic diisocyanate, and the product obtained then reacted with
a blockIne agent. Reference is made to U.S. Patent 2,958,704,
and the process disclosed therein.
The hydroxyl-containing vinylidene monomer has the
formula
CH2=C-A-OH
where A and R are defined as above. When A is a carbonyloxy-
alkylene radical, examples of the monomer include 2-hydroxy-
ethyl acrylate, 2-hydroxyethyl methacrylate, 3-hydroxypropyl
acrylate, 4-hydroxybutyl methacrylate, 4-hydroxybutyl ethacry-
late, 5-hydroxypentyl acrylate~ 5-hydroxy-3-methylpentyl
acrylate, 6-hydroxyhexyl acrylate, and the like. When A is an
aralkylene or alkyl substituted aralkylene radical, examples
include o, m, and p-vinyl benzyl alcohol, o-methyl-p-vinyl
benzyl alcohol, and the like,
me hydroxyl-containing monomer is reacted with an
aromatic diisocyanate using at least a slight molar excess of
the diisocyanate. Temperature of reaction is from about 0C. ~ ~ -
to 100C. The reaction must be conducted free of water.
~041~
Solvents for the reaction are benzene~ toluene, chlorobenzene, ~-;
chloroform, carbon tetrachloride, trichloroethylene, and the
like. The aromatic diisocyanates ha~e the formula OCN-B-NCO
wherein B is defined as above. Examples of these diisocyanates
are 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, naphtha-
lene-1,4-diisocyanate, diphenyl diisocyanate, diphenylmethane-
p,p'-diisocyanate~ dimethylphenylether diisocyanate, 3,3'-
dimethyl-4,4'-biphenyl diisocyanate, p-isocyanatobenzyl iso-
cyanatel bis(2-isocyanatoethyl)benzene, and the like. Halo-
genated diisocyanates such as 1-chloro-2,4-diisocyanatobenzene,
tetrachloro-1,3-phenylene diisocyanate, 2,4,6-tribromo-1,3-
phenylene diisocyanate, and the like, can be used. ~ ;
The more pre~erred aromatic diisocyanates are those
wherein one of the isocyanate groups has a l to 4 carbon atom
alkyl group ortho to one of the isocyanate groups. Examples
of these are 2,4-toluene diiæocyanate, 2,6-toluene diisocyanate,
and ortho-methyl substituents of other aromatic dlisocyanates
such as 2-methyl-1,4-naphthalene diisocyanate, 5-methyl-diphenyl
diisocyanate, 2,6-dimethyltoluene-1,4-diisocyanate, 3-ethyl-
1,4-toluene dlisocyanate, 1,6-dimethyl-2,4-toluene diisocyanate,
3,6-dimethyl-5-ethyl-1,4-naphthalene diisocyanate, and the like.
The ortho-substituted aromatic d~isocy~nates are pre-
~erred,as the unhlndered isocyanate group will react first and,
pre~erentially, with the hydroxyl group of the monomer. The
hindered isocyanate group tends to remain apart from this
~;~ reaction and good yields of the unsaturated aromatic isocyanate
are obtained. The product obtained is reacted with a compound
havlng a labile hydrogen atom to block the remaining isocyanate
group.
30~ The choice of a compound to be used as a blocking
age~t is particularly crucial to the successful use of a
blocked isocyanate in~nonwoven fiber bonding applications. I~
, ': - 11
~4~
the blocking agent - isocyanate reaction product is too stable,
the agent will not release quickly and/or at moderate tempera- -
tures. High temperatures and long heating times can degrade
the polymers and the nonwoven fibers. Many tertiary alcohols,
phenols, amines, and imines were found to be unsatisfactory
for this reason. If the blocking agent - isocyanate reaction
product is too labile, the agent will release prematurely
and the isocyanate will be free to react. This results in
instability of the interpolymer latex or solution and problems
in applying snd heat curing. The novel interpolymers of this
invention provide an improved balance between polymer stability
and quick, moderate temperature cure cycles. This balance is
struck and the excellent properties obtained only when a
combination of an aromatic diisocyanate and the specified
blocking agents are employed.
Blocking agents for the ethylenically unsaturated
aromatic diisocyanates are oximes,benzlmidazole, pyrazoles,
benzotriazoles, caprolactam, thiocaprolactam, and p-nitro-
aniline.
me oximes are aldoximes or ketoximes of the formula
H0-N=C
~R"
whereln R' is an alkyl radical containing 1 to about 8 carbon
atoms, a cycloalkyl radical containing 4 to 8 carbon atoms,
an aryl radical containing 6 to about 12 carbon atoms, or
where R' and R", together with the carbon atom, form a carbon
ring of 4 to 8 carbon atoms, and R" iæ hydrogen or the same
as R'. Examples of the oximes are acetoxime, methylethyl , i
ketoxime, methylpropyl ketoxime, methylisobutyl ketoxime,
ethylhexyl ketoxime, cyclohexanone oxime, benzophenone oxime,
benzoaldoxime, and the like.
-.:
: .
- 12 - ~
Pyrazole and 1 to 4 carbon atom alkyl substituents
thereo~ can be employed. Examples are pyrazole, 3-methyl
pyrazole, 3,5-dimethyl pyrazole, and the like.
The benzotriazoles are benzotriazole and 1 to 4
carbon atom alkyl, halogen, and nitro substituents thereof.
Examples of the benzotriazoles are benzotriazole, 5-methyl-
benzotriazole, 6-ethylbenzotriazole, 5-chlorobenzotriazole,
5-nitrobenzotriazole, and the like.
The blocking agents are employed on about a 1 to 1
mole basis of isocyanate to agent. The reaction temperature
is from about 30C. to about 110C. Reaction time is from
about 1 hour to about 15 hours. Suitable solvents for the
reaction are aromatic hydrocarbon solvents such as benzene
and toluene.
The ethylenically unsaturated blocked aromatic
diisocyanates can be polymerized using emulsion (latex),
suspension, solution~ and bulk techniques known to those
skilled in the art. The polymerization can be performed as
a batch reaction~ or one or more ingredients can be propor-
tioned during the run. Temperature of polymerization ranges
from about -lO~C. to about 100C., whereas a more preferred
range is from about 5C. to about 80C.
The polymerization is initiated by free-radical
generating agents. Examples o~ such agents are organic
peroxides and hydroperoxides such as benzoyl peroxide, dicumyl
peroxide, cumene hydroperoxide, paramethane hydroperoxide, and
the like, used alone or with redox systems; dlazo compounds
such as azobisisobutyronitrile, and the like; persulfate salts
such as sodium, potassium, and ammonium persulfate, used alone
~ .
- 13 -
1~4i~0~
or with redox systems, and the use of ultraviolet light with
photo-sensitive agents such as benzophenone, triphenylphosphine,
organic diazos, and the like.
Typical emulsion polymerization ingredients would
include a persulfate salt or organic peroxide and uqually a
redox system, water adjusted to a desired pH with acids or
bases and usually buffered with inorganic salts and either
anionic, cationic, or nonionic surface active agents well
known to the art. -
The polymerization normally is continued until about
90% or more conversion of monomers is obtained. The resulting
latex can be coagulated to isolate the polymer. Typical
coagulation procedures are salt/acid coagulations, use of
polyvalent metal salts such as MgS04, use of alcohols such as
methanol and isopropyl alcohol, and freeze agglomeration
techniques. The polymer is then usually washed wlth water
and dried. -
The polymers are comprised of~rom 0.1 percent to
100 percent by weight (i.e., homopolymers) of an ethylenically
unsaturated blocked aromatlc diisocyanate(s), as defined, and
up to 99.9 percent by weight, and more preferably up to about
70 percent by wei~ht, o~ a copolymerizable vinylidene monomer.
Thls monomer is a vinyl monomer having a terminal vinylidene ;
(CH2=C-) group. Examples o~ these monomers are acrylates and
methacrylates such as ethyl acrylate, n-butyl acrylate, octyl
acrylate, dodecyl acrylate, methyl methacrylate, phenyl acrylate,
cyclohexyl acrylate, and the like; vinyl and allyl esters such
as vinyl acetate, vinyl propionate, vinyl butyrate, allyl
acetate, and the like; vinyl ketones such as methyl vinyl
..
ketone? propyl vinyl ketone, and the like; vinyl and allyl
ethers such as vinyl methylether, vinyl ethylether, vinyl
. . .
isobutylether, allyl methylether, and the like; vinyl aromatics
.
- 14 -
1(~41~Ql ;
such as styrene, ~-methylstyrene, p-chlorostyrene, vin~l
toluene, vinylnaphthalene, and the likej vinyl nitriles such
as acrylonitrile, methacrylonitrile, ~-chloroacrylonitrile,
and the like; dienes such as butadiene, isoprene, chloroprene,
2-isopropyl-1,3-butadiene, and the like, ~-monoolefins such
as ethylene, propylene, l-butene, l-hexene, and the like;
vinyl halides such as vinyl chloride, vinyl fluoride, vinyl-
idene chloride, and the like; and divinyls such as divinyl
benzene, divinyl ether, diethylene glycol diacrylate, and the
like. In addition, because the isocyanate is blocked, so-
called reactive monomers can be copolymerized with the acrylates
and unsaturated lsocyanate. Examples of these monomers are
vinyl carboxylic acids such as acrylic acid, methacrylic acid,
ethacrylic acid, 2-hexanoic acid, and the like, vin~l amides
such as acrylamide, methacrylamide, N-methyl methacrylamide,
dlacetone acrylamide, and the like; hydroxyl-containing vinyl
monomers such as allyl alcohol, vinyl benzyl alcohol, ~- ;
hydroxyethyl acrylate, ~-hydroxypropyl acrylate, 4-hydroxy-
butyl acrylate, ~-hydroxyethyl methacrylate, N-methylol
acrylamide, and the like.
The polymers are high molecular welght solids having
dllute solution viscosities (DSV) of over 0.5 measured on a
0.2 gram sample of the polymer in 100 milliliters of solvent
at 25C. The polymers are cured at temperatures as low as
80C. and can be cured under acidic, neutral, or basic pH
conditions.
, . .
The polymers can be admixed with cure ingredients and
compounding ingredients using two-roll mills, internal mixers
; such as Banburys and extruders, and like equipment.
~ The polymers, as isolated solid rubbers, can be
- cured to prepare useful vulcanizates. Compounding ingredients
well known to the art can be used, such as fillers, oils and
~ 15 -
.,.: . . - - ~
~ 041~0iL
plasticizers, antioxidants, and the like. Standard mixing
and cure techniques are employed. Upon heating the polymer,
the blocking agent is released. Hydroxyl, carboxyl, and
amine containing materials are used as curing agents. For
example, glycols, polyols, polyalkylene amines, hydroxyl and
carboxyl containing polyesters and polyethers, hydroxyl,
carboxyl, and amine terminated vinylidene polymers, etc., and
water itself, are all known and suggested reactants for iso-
cyanate-containing materials. If the interpolymer itself
contains hydroxyl, carboxyl, or amine groups, the polymer can
be considered self-curing. Upon heating, the isocyanate is
released and the polymer can undergo intra- and inter-molecular
crosslinking.
The polymers do not have to be isolated, but can be
readily stored in latex or solution form. The novel polymers
have excellent stability in latex form. In non-woven binder
applications, the polymers are conveniently used as latexes
or solutions to coat or impregnate the fibers. Fillers,
extenders, and other ingredients such as stabilizing agents,
thickeners, antioxidants, and the like, are readily admixed
with the latexes or solutions prior to u~e.
In non-woven flber binder applications, the ethylen-
ically unsaturated bl~ked aromatic diisocyanates are preferably
copolymerlzed with an acryiate monomer. The interpolymer com-
prises from about 0.5 percent to about 50 percent by weightof the diisocyanate(s) as defined, and from about 50 percent
to about 99.5 percent by weight o~ an acrylate monomer(s).
More preferably, the interpolymer contains from about 1 percent
to about 30 percent by weight of the diisocyanate, from about
70 percent to about 99 percent by weight of an acrylate monomer,
and up to 20 percent by weight of another copol~merizable
.. .: .. ..
vinylidene monomer, all present as interpolymerized units.
- 16 -
.
~U4~
The acrylate monomer has the formula
R 0
CH2=C- C~Ra
wherein R is H, -CH3 or -C2H5~ and Ra is an alkyl radical
containing 1 to about 24 carbon atoms, an alkoxyalkyl or
alkylthioalkyl radical containing a total of 2 to about 12
carbon atoms, or a cyanoalkyl radical containing 2 to about
12 carbon atoms total. The alkyl structure can be linear or
branched Examples of the acrylates are methyl acrylate,
ethyl acrylate, n-propyl acrylate, isopropyl acrylate, isobutyl ~
acrylate, n-pentyl acrylate, isoamyl acrylate, n-hexyl acrylate, ~ -
2-methylpentyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate,
n-decyl acrylate, n-dodecyl acrylate, n-tetradecyl acrylate,
n-octadecyl acrylate, n-eicosyl acrylate, and the like, methyl
methacrylate, ethyl methacrylate, n-hexyl methacrylate, n-
octyl methacrylate, n-dodecyl methacrylate, n-octadecyl meth-
acrylate, ethyl ethacrylate, n-butyl ethacrylate, and the like,
methoxymethyl acrylate, methyl acrylate, methoxyethyl acrylate,
ethoxyethyl acrylate, butoxyethyl acrylate, ethoxypropyl
.
acrylate, methoxyethyl methacrylate, methylthioethylacrylate~
hexylthioethyl acrylate, and the like; and a and ~-cyanoethyl
acrylate, a, ~, and ~-cyanopropyl acrylate, cyanobutyl acrylate,
cyanohexyl acrylate, cyanooctyl acrylate, cyanoethyl meth-
; acrylate, and the like. O~ten mixtures of two or more monomers
~ and/or types o~ acrylate monomers are employed.
-~ 25 More preferably, the interpolymer contains from 70
percent to about 99 percent by weight o~ an acrylate monomer(s)
whereln Ra is an alkyl radical containing 1 to about 18 carbon
atoms or an alkoxyal~yl radical containing 2 to about 8 carbon
atoms. Examples of the more preferred monomers are methyl
acrylate, ethyl Icrylate, n-propyl acrylate, isopropyl acrylate,
~ n-pentyl acrylate, isoamyl acrylate, n-hexyl acrylate, n-octyl
;~ _ 17
acrylate, 2-ethylhexyl acrylate, n-decyl acrylate, n-dodecyl
acrylate, n-octadecyl acrylate, methoxyethyl acrylate, ethoxy-
ethyl acrylate, methoxypropyl acrylate, ethoxypropyl acrylate,
and the like. Both an alkyl acrylate and an alkoxyalkyl
acrylate can be used. Especially good results are obtained
when employing ethyl acrylate, octyl acrylate, 2-ethylhexyl
acrylate, and/or methoxyethyl acrylate.
The interpolymers are applied to the non-woven fibers
using dip coating, knife edge coating, roller coating, soaking,
spray coating, and like known techniques. Cure conditions
depend in part upon the specific blocking agent and aromatic
diisocyanate used to prepare the monomer. However, temperatures
from about 80C. to about 150C. and more preferably from about
100C. to about 125DC. are usually employed. Cure times range
from about 3 minutes to about 30 minutes. An excellent cure
is readily obtained at 100C. in about 3 minutes at an acidic,
neutral or basic pH.
Examples o~ non-woven fibers are papers such as
Kraft paper, crepe paper, and the like, rag fibers, cotton,
wool, regenerated cellulose, glass fiber, asbestos, and
synthetic fibers such as polyesters~ and the like. In
addition to binding fibers to impart tensile strength, edge
tear strength, and the like, the lnterpolymers are also use~ul
as pigment and filler binders and as fabric adhesives.
The polymers can be copolymers of the essential
blocked diisocyanate with acrylate monomers and from about
~ .....
0.5 percent to about 10 percent by weight of a hydroxyl,
carboxyl, amlne or amide containing monomer. ~fter applying
such an interpolymer to a non-woven substrate and heating it~
the blockingagent is released and the free isocyanate cross-
links through these reactive groups to cure the polymer. -
However, if the polymer does not have these groups present
- 18 -
thereon, compounds containing the groups can be readily added
to the latex or solution prior to use. These compounds are
crosslinking agents, and include aliphatic and phenolic diols
and polyols, diamines and polyamines~ di- and polymercaptans,
di- and polycarboxylic acids, and polymeric materials such as
polyether polyols, polyester polyols, polyester amides, poly-
ether amides~ and the like. Examples o~ crosslinking agents
are alkylenediols such as 1,4-butanediol, 1,6-hexanediol, 4-
methyl-1,4-pentanediol, l,10-decanediol, and the like; ali-
cyclic diols such as 1,4-cyclohexanediol, 2-hydroxymethyl-
cyclohexanol, and the like; phenolic diols such as p hydroxy-
benzyl alcohol, hydroquinone, 2,2'-dihydroxydiphenyl, methylene-
bisphenol, p,p'-isopropylidene bisphenol, and the like; polyols
such as 1,3,5-pentanetriol, 1,3,5-trishydroxybenzene, glycerol,
sorbital, and the like; alkylenediamines such as ethylene-
diamine, 1,2-butylenediamine, 2-methyl-1,4-diaminobutane,
hexamethylenediamine, decamethylenediamine, dodecamethylene-
diamine, and the like; alicyclic diamines such as 1,4-diamino-
cyclohexane, 1,4-diaminoethylcyclohexane, and the like; aro-
matic diamines such as m-phenylenediamine, m-xylylenediamine,
3,3'-diaminobiphenyl, 4,4'-diaminodiphenylmethane, p,p'-bis-
aminomethyl diphenylmethane, and the like, heterocyclic dl-
amines such as piperazine, aminoethylpiperazineg and the like;
polyamines such as diethylenetriamine, triethylenetetraamine,
and the like; and alkanolamines such as tris(hydroxyethyl)
amine, bisthydroxyethyl)methylamine, tris(hydroxypropyl)amlne,
l-amino-2-hydroxypropane, l-aminomethylcyclohexanol, m-amino-
phenol, 2-amino-6-hydroxypyridine, and the like. The more
pre~erred crosslinking agents are the alkylenediols, the
alk~lenediamines, and the alkanolamines.
The crosslinking agent can be added directly to the
latex (or solutionj. It can be dissolved in a solvent such
~(~4~L~Q~
as chloroform or trichloroethylene, or suspended in water
using an emulsifying agent, and then added to the latex or
solution. No reaction takes place until the blocking agent is
released in the cure process. The crosslinking agents are
used on about a mole to mole basis of isocyanate to hydroxy,
amino, etc., group. Higher levels may be used, but it is not
necessary for obtaining fast strong cures.
Of course, water alone can act as a crosslinking
agent for the polymers. In the presence of water, the blocked
diisocyanate can react to form an amine structure which can
then further react with another blocked diisocyanate group to
crosslink the polymer. The water can be added to the polymer,
or it can be present as residual water in the polymer or
saturated non-woven. Atmospheric moisture can also act to ; -
crosslink the polymers.
As the novel interpolymers have particular utility
as binders for nonwoven fibers, testing was directed to
evaluation of the interpolymers in latex form as paper
saturants. Actual testing included original and wet tensile
strength, using an Instron tensile tester at a pull rate of
12 inches per minute. Wet tensile followed TAPPI procedure
T465-m44 (specimens soaked in water for 16 hours before teGting).
The following examples serve to more fully illustrate
the invention. .
EXAMPLE I
A series o~ ethylenically unsaturated blocked aro-
matic diisocyanates was prepared. The general reaction scheme
is to first react a mole of a hydroxyl-containing vinylidene
monomer with about two moles of an aromatic diisocyanate, and
secondly, react the intermediate product with about 1.1 mole of
a defined blocking agent per mole of the intermediate.
. Preparation of 4-(0-methacryloyloxyethyl)-
.
- 20 -
1~4~
urethanotolyl(2-carbamoyl)-1-tolyltriazole. The synthesis
consists o~ a two-step reaction. Toluene, 1080 grams and 2,4- -
toluene diisocyanate~ 1160 grams (6.66 moles), were put into
a reactor vessel equipped for stirring and temperature control.
The vessel was then flushed with nitrogen ~as and the inter-
mediate product reaction conducted under nitrogen gas. The
mix was heated to 60C. while stirring, and 433 grams (3.33
moles) of ~-hydroxyethylmethacrylate slowly added over 5.5
hours. Temperature o~ the mixture rose to 65~C. and was con-
trolled there throughout the addition. The mixture was thenstirred for one hour. Total reaction time was about 7 hours.
The reactor mixture (a solution)was cooled to 5C.
and allowed to stand ~or about 16 hours. White crystals formed
in the solution. me mixture was then cooled to -30C. and
the crystals filtered out and washed with hexane. The inter-
mediate product was dried to yield 754 grams o~ a white
crystalline solld having a melting point of 71-72C. Analyzed
~or isocyanate content and for unsaturation, the intermediate
product proved to be about 99% pure. The yield was 74~ by
20 ~ ~ weight based on the theoretical weight as measured on the
hydroxy compound.
The intermediate product (i.e., the ~-hydroxyethyl-
methacrylate/2,4-toluenediisocyanate reaction product), 22.3
.
grams (0.0735 mole) was dissolved in 350 milliliters o~
toluene at about 30C. and the solution placed into a reactor
vessel., Tolyltriazole, 10.75 grams (o.o808 mole) was dissolved
in 50 milliliters of toluene at about 30C. and the solution
then~added to the reactor vessel. The mixture was stirred for
3~hours at 30~C. and then at 50C. for 0.5 hour. A white
3~ precipltate forms during the stirring time. Total reaction
time is about 4 hours. -
- The reaction mixture was cooled to 0C. and the white
~ ~ .
.
21 -
~ ~ .
~(~4~
precipitate isolated by filtration. The product was washed
with acetonitrile and dried at 25C. under a vacuum to yield
25.6 grams of a crystalline solid having a melting point of
132-133.5C. The yield was 80~ based on the amount of inter-
mediate product used. Analysis by unsaturation showed theproduct to be about 99% pure. The product has the structure
O N=N~
CH3 O O NH-C-N~
CH2=C - COCH2CH2-OC-NH ~ CH3 ~
B. Preparation of 4-(0-mPthacryloyloxyethyl)ure-
thanotolyl(2-carbamoyl)-2-butanone oxime. The intermediate -
product prepared above was employed.
Toluene, 2686 milllliters, and 517 grams (1.7 moles)
of the intermediate product were placed in a reactor vessel
and stirred. Methylethyl ketoxime, 152 grams (1.74 moles)
was dissolved in 260 milliliters of toluene and the solution ~ `
added to the reactor vessel slowly over a 1.5 hour period.
Temperature of the reaction was kept at 28-290C. The mixture
was then stirred for 16 hours at about 25C., followed by
cooling to -30C. A white preclpltate formed whlch was
flltered out and dried to yleld 494 grams of product (a 74%
yield). The crystalline product has a melting point of 80.50-
820C., and analyzed by unsaturation to be about 98% pure.
The theoretlcal nltrogen content of the product is 10.7~ by
weight and the analyzed nitrogen content was measured to be
10.6~ by weight. The product has the structure
.
,~ C2H5
~ ,CH3 1t ~ NH-CON=C
CH2-C - COCH2CH2-OC-NH ~ CH3 CH3
:
- 22 -
Ql
C. Following the procedure given in B above, the
~ollowing compound was prepared by reacting the intermediate
product with acetoxime:
" ,CH3
CH O O NH-CON=C
~ 3 ~ r--<
CH2~C - COCH2CH2-OC-NH ~ 3 H3
D to E. Following the procedure given in B, the inter-
mediate product was reacted with meth~lisobutyloxime and di-
methylpyrazole, respectively, to yield:
CH3-1CH-CH3
,0, Cl H2 . .:
CH3 0 0 NH-CON-C
t~ It
CH2=C COCH2CH2-OC-NH ~ CH3 CH3
melting point o~ 75-79.5C., and
O / ~ H3
CH3 ,0, ,, ~ NH-C-N
CH2-C COCH2CH2-OC-NH ~ CH3 CH3
melting point of 109-110.5C.
F. Followlng the procedure glven in A above~ ~-
hydroxyethyl acrylate and 2,4-toluene dlisocyanate were
reacted together to form an intermedlate product which was
then reacted with methylethyl ketoxime. The product is
~; O ,C2H5 ', '.
H O O~ ~ H-CON=C
CH2-C-COCH2CH2-OC-NH ~ CH3 CH3
melting point of 1~08-113C. The compound was tested to be
95% pure using a standard isocyanate analysis test.
G. Following the procedure given in A æbove, ~
. ' ' "
- 23 - ~
Q~
p-vinylbenzyl alcohol was reacted with 2,4-toluene diisocyanate,
followed by reaction with methylethyl ketoxime. The product
is . ~ .
o C2H5
H O NE-CON=C
CH2 C ~ CH2-OC-NE ~ CH3 CH3
melting point of 79.5~-83C.
FXAMYLE II
The ethylenically unsaturated blocked aromatic di-
isocyanate prepared ln Example I in procedure B was inter- ~ - :
polymerized with a vinylidene terminated monomer, using an
emulsion polymerization system. The recipe is as follows: - i
Ethyl acrylate grams 94.1 `
Diisocyanate B~ grams 5.9
Water, milliliters 175
Sodium lauryl sulfonate 30
millilitersb
N~halene sbulfonate, 9
milliliters
Sodium hydrosulfite, 8.3
, millilitersC,
Sodium formaldehyde sulfoxalate, 10
millilitersd
Sodium salt of ethylene diamine 8.3
tetraacetic acid and sodium
gluconate, milliliterse
p-methane hy~roperoxide, 0.2
millilitersl
O
CH3 O O H-coN=c~ 2E5
a CH2=C - COCH2CH2-OC-NE ~ CH3 CH3
b 10% by weight in water ;
c o,5% by weight in water
d 1.0% by weight in water
.
e 0.24 and 0.13 grams in 100 milliliters of water
f 50~ by weight
The dlisocyanate was dissolved in the ethyl acrylate,
and the solution admixed with the water, sodium lauryl sulfonate,
".. '.
- ' ~:,
- 24 -
- .
.. . ... .. . ~ . ~ , ~,. ., , , .. - .
sodium hydrosulfite, and naphthalene sulfonate. 17 milliliters
of the mixture was placed in a reactor vessel followed by the
sodium formaldehyde sulfoxalate, sodium salt of ethylene
diamine tetraacetic acid and sodium glyconate, and p-menthane
hydroperoxide~ An immediate exotherm occurred and temperature
of the reaction was controlled at 27~3C. Using a stirred
dropping funnel, the remaining mixture was slowly added to
the reactor vessel over a 1 hour period. After the addition
was complete, the reactor mix stood for 16 hours. Total
conversion of monomers to polymer was 96%, based on the total
solids of the mix.
EXAMPLE III
Interpolymers of ethylenically unsaturated blocked
aromatic diisocyanates (as prepared in Example I) and ethyl
acrylate, were prepared following the procedure of Example II.
The ~ollowing polymeric samples were prepared and evaluated
in thelr latex form.
.
- 25
'
:
N 1~ C ~ m
~i~ V- ~- V U- ~- U V--V--V--V
o= V ~ o- V ,~ O- V ~ U o
~I z
Oo _ V o _ V o = V o- o , ~ ,
rlU V V V ' '
~v~ ~ ~ . u
o- VO Ot V o C~ O- U . .
N ~ P l
: :~` .3 ,,~
. ~ .~ ` ` .
.. . ~ . .
26 - -
I ~ 11 14~
æ ~N ~ N
o~ o
~d 5~ ~ O O = C~
a) ~; 1o = ~ ~ , ~ ~ -
I P~ ~ V a)
~PJ~ . ~
o ~
o æ
p~ o= O ~ o ~ .
P~
~ ~ 1 o
Or ~
, ~ , , o . .:
: ' -
o ",
. ~ ,..
C) C) . ~, . . .
o~
:
-- h
C) ~ ' '.,
.
~ ' ,, .
' ' ' ' '- ' ~, ' '
.
' ' .
-- 27 --
~ . ,
.. .
The latex samples were used at a total solids content
...... .. .
of about 20% by weight. The non-woven ~iber employed was
saturatlon grade, bleached Kraft paper of 11 mils thickness.
8 inch by 1 inch strips of the paper were soaked in each
sample latex. Solids pickup was about 50~ by weight for each
test strip. The strips were then dried at room temperature
followed by curing at selected temperatures and times. When
an added crosslinker was employed, it was dissolved in or
added to the latex as a solution or suspension prior to soaking
I0 the paper strips.
Evaluation consisted of wet tensile strength testing
following Tappi procedure T465-m 44. The impregnated paper
strips were soaked overnight in water and then pulled on an
. . , :, .
Instron tensile tester at a ~aw speed of 12 inches per minute.
Test strip samples were run in triplicate and the arithmetric
average reported.
The crosslinker employed in this series o~ experi-
ments i8 either residual water (i.e., no crosslinking agent
was added~ or triethanol amine. When triethanol amine was
used, it was simply dissolved in the latex, prior to soaking
the samples? at none, one, or two mole equivalent~ of cross-
linker per mole equivalent o~ isocyanate group on the polymer.
The data obtained is listed in the ~ollowing table.
Wet Tensile Strength
Latex Part~ by Wt. of 3 Mlnute Cure At
Sample Triethanol aminea 100C. 125C. 150C.
none 18 20 20
0.75 21 20 21
1.50 22 20 22
3 B none 20 22 23
1.~0 22 24 25
C none 15 21 27
0.?5 18 23 29
, . .
D none 20 22 21
3~ - 0.75 20 21 21
,
f
- 28 - -
l~ L101
Wet Tensile Strength
Latex Parts by Wt. of 3 Minute Cure At
Sample Triethanol Aminea 100C. 125C. 150C.
E none 22 23 24
1.50 20 23 22
F none 21 22 23
0.75 21 24 24
G none 19 23 22
0.75 20 23 24
aParts by weight per 100 parts by
weight of polymer in the latex
The data shows that excellent wet tensile strength
is exhibited by all of the æamples. The paper strip, without -
. .
being impregnated by the novel polymers, has a wet tensile ~-
strength of about 0.5 psi. The Example shows the excellent -
results obtained using the novel polymers in latex form as
non-woven fiber binders. me strength obtained is as good as
or better than results obtained using commercial latexes,
especially at low cure temperatures. For comparison, a
commercial acrylic latex would exhibit, cured at lOO~C. using
no crosslinker, a wet tensile strength of about 4 psi at a
basic pH to a high of about 16 psi at an acid pH.
EXAMPLE IV
Following up Example III in more detail, sample
latex A was used to prepare wet tensile ~amples at various
pH's of the latex. Using 0.90 parts by weight of 1,6-hexane-
dlol as a crosslinker, after cure at 100C. for 3 minutes,
the wet tensile strength values were: pH of 5, 20 p8i, pH of
7, 20 psi, and pH of 9, 19 psl. Repeating the test using 0.75
~ parts by weight of triethanol amine as the crosslinker, the
values were: pH of 5, 21 psi; pH of 7, 21 psi; and pH of 9,
21 psi. In contrast, two commercial acrylic latexes were also
evaluated as to their ability to impart wet tensile strength
over a range of pH values with the following results: p~I of 5,
.
,
,
., - - . :
- 29 ~
~.L~Ql
11 psi and 6 psi, respectively; pH of 7, 8 psi and 6 psi~
respectively; and pH of 9, 4 psi and 4 psi, respectively.
The exam~le shows that not only do the polymers of the
invention impart greater wet tensile strength to non-wovens
than known commercial latexes, compared at a 100C. cure
temperature, but the novel polymers are also not sensitive to
pH as the commercial acrylic latexes are. At a cure temperature :
of 80C., a test sample using the novel polymer prepared as
sample B had a wet tensile strength of 14 psi (cured 3 minutes). ~
The difference between the novel polymers of the invention - ~,
and the commercial latexes diminishes as the temperature of
cure increases and the pH of cure decreases. However, fast
:
cures at low temperatures over a range of pH conditions is
highly desirable.
. . .
EXAMP~E V
The ultimate tensile strength and wet tensile
strength of a bound non-woven fiber is a function of both
the polymeric binder and the crosslinking agent employed. Of
the known crosslinking agents, the use of alcoholic amines is
preferred with the novel polymers of this invention. Using
the polymer latex prepared as sample A in Example III, and
following the procedure given in Example III, various cross-
linking agents were evaluated at one equivalent weight as to
their abillty to develop rapid and high strength cures.
. .
30 -
Ql ~ ~
.: - . . .
~,
o ~C--O ~ ~-
.l C~J N N cu c~l
~ ~1
":':
o
u~ C~ N C~ N N ~1
~1 rl . .. :
~ O ~ ~ ~ ~1 ~1 ~ CU ~ "
O ~1 ~I N ~ C~J C~ ~I h ;-
a~ ~1 . ~ .. .
E~ h
ol ~0 o ,I N o
~3: X) l ~1 ~1 ~ ~I N c~
o : :
~ ~ o bD "' ~`"'''
. .
. . o 0~ 1~ 0 00 0 ~ rl h
. .... , . ~q o
~R O ~ O O O
a~ . ~
P~ ~ o : . .,
o
0
O ~ h
. ~ ~ ~ ~r O O r~
~: ~E c h
r~ O ~r ~:! r ~ a) ~q .
O ~rl ~ ~ Ci ~r~ ~C
O ~ r ~ ~3 a
~ ~:! O r~ a) r~ cq h,r-l
- ~d c~ ~ O ~1~ n~ ~ a 5
. a) ~ c~ o o
rl ~ 5'~ ~ ~ ~ O ~ ~q 5'~ ::
~0 O . I O (1~ ~ 5 N ~Q Ul t~ h
- O 5~0 r1~ ~ r~ rl
h O ~ ~ h ~rl C) ~ r~
C,) ~z; r-l r~ ) r~ cB ~ C)
.~ ~ - : '' - " ' '
r~
r~ 0
~ ,..... ..
:. , ; . .:
:: :
` ~: . ~: :
::
EXAMPLE VI
The polymers of the present invention present a
unique balance between rapid cure at low temperatures
(evidencing quick, efficient release of the blocking agent)
and stability, especially to hydrolysis in the presence of
water. This unique balance is struck by the use of both the
aromatic dilsocyanate and the specified blocking agents in
the preparation of the novel ethylenically unsaturated
blocked aromatic isocyanates. The following data shows that
the polymers of the invention have good stability to hydrolysis.
Polymer latex sample B prepared in Example III is employed. ~
Testing consisted of wet tensile strength before and after ;
aging at room temperature.
Wet Tensile
Sample B Strength, psi Time Aged
Test Strip Cl~rginal Aged (days) ~;
.:
Cured ~i
3' at 100C. 20 14 50 -
12 100
;
3' at 125C. 22 19 50
17 100
3' at 150C. 23 19 50
18 100
Aged in presence
0~ 0.75 parts by
wt. of triethanol
amine
Cured 3' at 22 19 50
100C. 22 17 100
3o EXAMPLE VII
Expanding on Example VI, other polymers o~ this
invention were prepared following the procedures given in
Examples I and II, and evaluàted as to their stability to
hydrolysis and their ability to impart wet tensile strength
to non-woven flbers. Original and aged wet tensile strength
~ . - .
of impregnated non-woven paper was determined following the
~ - 32 -
1~4~ Q~ :
procedure in Example III. Results are reported in the
following tables.
, ~, .
: . .
. ', '
~- :
- '' '
.' ";
.
. ::
, . . .
.,: , ::
' ~
- ... . . .. ..
~ _ 33 _ ~ .
: : ;
Ql
~ ~, .
V V V V V V V ~ ~
~ , ~ v ~ v
~ V- o V ~ V- o ~ o
~~ ~ X .. : '
~3
C) o= ov o- V o ~ o ,
o
~ ~ V V
~v~ ~ v~
. o o o
7 1
o vl ~ ~
C~- V , V- V
V- V ..
.
V C~ V
. ..
,, , .: :.
. ,~
~ .o~ ~o
h 00 ~ :
a~
1:4 ., ', '
~ , .~
''
a) :
~1
. ~j :' "'
U~ ,:
P:~ H ~
O : :
: "; ' ,
.
' ' ,', . ~:
- . - 34 -
. .- . : - ::-
v
~ ~ ~ ~ o ~
~ v- v v- v- v o
o-v ~
l ~ o ~ ~ o
q o = ~ ~ :
~d~ ~
~ o- v l l ~ :
c) o o- v o- v
o l o o ~
V ~ ~ ~:
~ p:~ P:~
o v v
o- v o o ~
I o I o
p~
v v o ~ :
~ ~ .. .
: ~ . ll
:~ ~ ~
~ o ~ :
~ . tq
~ : p~
~O O o o
F~ h ~, h
P~
~ bD ~
O ~ 1~1 ¢
~ ;~
~ .
O : .: ' '
P~ . . ~
. '
:: ,
.~ .
:.
' ~
- 35 ~
- ; ,
.. . . ~ ~ . ,
...... .: ~ . . , . ~ .. . . . .. . . . .. . . .
The polymers above, in latex form, were used to
impregnate saturation grade, bleached Kraft paper (11 mils
thick) ~ollowing the procedure in Example III. The test
sample strips were then evaluated for their original wet
tensile strength. Following Example VI, after allowing the
polymer latex samples to age, test sample strips were again
prepared and the wet tensile strength measured. Results are
reported below.
Wet Tens~le Average
Latex Stren~th , psi % Decrease -
Sample Original Aged ays Per Day
B 20 12 100 0.40
H 20 17 45 0.33
14 100 0.30
I 15 8 47 99
J 20 17 30 0.50
0.42
K 162 11 34 0.92
L 21 19 29 0-33
6~ 0.45
M 223 15 5 o.64
'
1 Cured 3 minutes at 100C., no
crosslinker added
2 At 15th day
3 At 70th day
The data shows that the polymers of the present
invention, samples B and H to M, prepared using the novel
ethylenlcally unsaturated blocked aromatic diisocyanates,
im~art good wet tensile strength to non-woven flbers, and
have unexpectedly good stability to hydrolysis when stored
as a latex. If a crosslinker and/or higher cure temperatures
are employed with the novel polymers, higher original and aged
wet tensile strengths are obtained. For example, sample I,
which showed the least stability, can be cured at 150C. using
0.75 parts o~ triethanolamine (after 47 days of aglng) to yield
,
- ~
~ - 36 -
.~, ' :. ..
a wet tensile strength of 19 psi.
EXAMPLE VIII
If, instead of reacting the hydroxyl-containing
monomer with the aromatic diisocyanate, the blocking agent is
first reacted with the aromatic diisocyanate, different
variations in the structure of the ethylenically unsaturated
blocked aromatic diisocyanate can be prepared. For example,
in Example I, procedure A, the following diisocyanate was
prepared:
.. N--N
CH3 0 0 ~ H-C-~
CH2=C - COCH2CH2-OC-NH ~ 3 ~
When the methylbenzotriazole was first reacted with the 2,4-
toluene diisocyanate, followed by reaction with the ~-hydroxy-
ethyl acrylate, the structure is:
CH3 0 o
" "
CH2~C - COCH~CH2-OC-N ~ " /N= N
CH3 ~ NH-C-N
~ CH3
me diisocyanate prepared by the reverse addition ;l ;
o~ materials can be easily polymerized with vinylidene-termin-
ated monomers via emulsion techniques, and is useful in latex
iorm as a binder ~or non-woven ~ibers. The following data
shows this fact.
Latex Wet Tensile Strength~ psib
::
pa 15 16 19 22
:' .
a 96% by weight ethyl acrylate,
4% by weight diisocyanate
b 3 minute cure
The~polymer was prepared following the procedure in
.: .
_ 37 _ ~-
-,
Example II. Testing followed the procedure in Example III.
Use of an added crosslinker raises the value of the we~
tensile strength.
EXAMP~E IX
Following procedures in previous Examples, the diiso-
cyanates made in Example I as C and E were interpolymerized
with ethyl acrylate and ~-hydroxyethyl methacrylate. The
polymers were evaluated in latex form as binders for non-woven
paper. Data is as follows:
Latex Wet Tensile Stren th psi
Sample lOODC. 12~C. ~ .
Qa 17 18 18
Rb 15 21 24
a 93.8% ethyl acrylate 1.5% ~-hydroxy-
ethyl methacrylate, ~.7% diisocyanateE
b 95.6% ethyl acrylate, 1.3~ ~-hydroxy-
ethyl methacrylate, 3.1% diisocyanate C
EXAMPLE X
Diisocyanate sample B from Example I was lnterpolymer-
ized~with ethyl acrylate via an emulsion polymerization process.
me recipe was:
Ethyl acrylate grams 20.4
Dllsocyanate Ba, grams 12.9
Water~ milllliter~ 68
Sodium laury~ sul~onate, 10
millilitersD
~mmonium persulfate~ grams 6.5
CH 0 -
1 3
a CH2=C C0-CH2CH2-OC-NH ~ CH3 ,C2H5
NH-C0-N~C
. . " ~ . .
0 CH3
~ b 10~ by weight ln water
3o me ethyl acrylate, diisocyanate B, sodium lauryl
sulfate solution, and 4 millillters of water were mixed
~together in a stirred dropping ~unnel. 2 milliliters of the
;; .' . ~ ,,,
~ _ 38 -
... . . .
a~ . .
mixture was then placed into the reactor vessel with 62 milli-
liters of water and the ammonium persulfate (dissolved in 2
milliliters of water). The temperature was raised to 50C.
and held at 55~ 2C. throughout the run. The remaining
monomer mixture was added over a 20 minute period. Total
reaction time was 1.5 hours. Percent conversion of monomers
to polymer was 96% based on total solids. The example demon-
strates that interpolymers containing high weight percents of
the ethylenically unsaturated blocked aromatic diisocyanates
of this invention can be readily prepared. In this example,
the interpolymer composition was about 61% by weight ethyl
acrylate and about 39% by weight of the specific diisocyanate. ;;
: '; ,' '
`-I . . :, ! . '. '
..
'~
~,' ~"'
.' ;''.
. .
" ~ ." '
' ~ ~ " ' , ' ' . ' ' '
.' "
, ~ ' ', ' ~. ,''-
_ 39 -
: - . .
. - ~ - , .
