Note: Descriptions are shown in the official language in which they were submitted.
115~79~
This invention relates to compositions which are curable by radiation
such as electron beam, actinic light or heat curable compositions. In one aspect,
the present invention relates to polyetherurethaneacrylates. In a ~urther aspect,
the present invention relates to substituted polyetherurethaneacrylates and to the
cured compositions produced therefrom. In yet a further aspect, this invention
relates to fluorocarbonpolyetherurethaneacrylates and to the radiation cured mat-
erials produced therefrom.
The advantages of radiation curable (especially actinic light curable)
polymers, such as the ability to precisely control the time and extent of cure,
increased shelf life and the utili~ation of undiluted (i.e., 100%) solids, has
motivated considerable research effort toward the development of these composi-
tions. The present invention is a novel radiation curable composition that is
particularly useful for specialty applications, such as in joining electro-opti-
cal components, and as a protective coating.
In one aspect, the present invention provides a radiation curable com-
position comprising a substituted urethane acrylate having an aliphatic backbone,
said backbone having an ether or polyether group and having at least one pendent
fluorinated organic group attached thereto, said pendent organic group having the
formula -W-Rf wherein -W- is a connecting moiety selected from a single bond,
-CH2-O-CH2, and -CH2OC-, and -Rf is a monovalent fluorinated organic radical hav-
ing 35 to 85 weight percent fluorine, and at least 75 percent of its carbon val-
ence bonds are attached to fluorine.
In a further aspect, the present invention provides radiation curable
fluorocarbon-substituted polyetherurethaneacrylates having the formula:
-1-
l 156795
--2--
O O O
2 11
R[t0cH2-cH)mocNH-R -(NHC0-R -OCC-CH2) ]n III
R
wherein:
R is the residue or reaction product of a
hydroxyl-containing material with an epoxy-containing
material the hydroxyl-containing material having n
hydroxyls;
n is an integer from 1 to 6 inclusively;
W is a polyvalent connecting moiety
Rf is a monovalent highly fluorinated
fluorocarbon radical;
m is a number having a value from 1 to about
20;
Rl is a polyvalent residue or reaction product
of an organic polyisocyanate, Rl(NCO)p (preferably a
cycloaliphatic or aromatic polyisocyanate) and a
hydroxyl-containing material, p having a value of 2
20 to 4;
R2 is a divalent saturated aliphatic group
havinq 2 to 6 carbon atoms and optionally one or two
non-vicinal catenary oxygen atoms; and,
R3 is hydrogen or methyl.
The fluorocarbon-substituted polyetherurethane-
acrylates (hereafter sometimes referred to as fluorocarbon
etheracrylates in the interest of brevity) of this
1 156~95
invention are curable (i.e., polymeriza~le) in the presence oE
catalysts or initiators which liberate or generate free-radicals
under the influence of radiation such as actinic light or infrared
radiation (heat). Free radicals can be generated in the system by
the thermal or photo decompostion of known free radical initiators
such as peroxides. Alternatively, the present materials have been
found to be curable by the means of electron beam irradiation even
in the complete absence of an initiator.
The cured materials of the invention can be utilized as
tack-free protective coatings. Further, the cured compositions
herein, having an optical transmission of greater than 95% and a
low refractive index, are well suited for use as adhesives in ap-
plications where optical transmissivity is required.
The fluorocarbon-substituted polyetherurethaneacrylates
of this invention are generally prepared by procedures well known
in the art. One synthetic route is as follows:
I. Preparation of a fluorocarbon-substituted polyether-
alcohol (hereinafter sometimes designated fluorocarbonalcohol or
fluorocarbonpolyoll.
-- 3 --
1156795
--4--
A fluorocarbon-substituted (the substitution
corresponding to -W-Rf in the final product) polyether-
alcohol is prepared by ring opening additlon
polymerization of a fluorocarbon-substituted epoxide with
a hydroxyl containing compound (containing n hydroxyl
group-~) initiator. This reaction may be written thus:
o
R(OH)n + mn CH2-CH atalys R[(O-CH2-CH~mOH]n
7 w
Rf Rf
In I, Rf ls a pendent, monovalent, highly
fluorinated aliphatic, aryl, or alkaryl radical. ~Pendent~
as the term is used herein means not of the backbone
carbon chain, i.e., non-catenary. ~y ~highly fluorinated~
is meant that generally 35 to 85 weight percent,
preferably 50-77 weight percent, of the fluorocarbon
radical is fluorine, with at least 75 percent of the
non-catenary carbon valence bonds being attached to
fluorine atoms. The weight percent of fluorine in the
preferably saturated pendent fluorocarbon radical is found
by dividing the total atomic weight of the radical into
the total atomic welght of the fluorine atoms present in
the radicals (e.g., -CF3 is 82.6 weight percent fluorine).
Where Rf contains a plurality of carbon atoms in a
25 skeletal chain, such chain may be straight, branched or
cyclic but preferably is straight. The skeletal chain of
carbon atoms can be interrupted by divalent oxygen or
1 1~6795
--5--
trivalent nitrogen heteroatoms, each of which is bonded
only to carbon atoms, but where such heteroatoms are
present, it is preferable that the skeletal chain contain
not more than one said heteroatom for every two carbon
atoms. ~n occasional carbon-bonded hydrogen atom, bromine
atom, or chlorine atom may be presentJ Where such atoms
are present, they are preferably present to the extent of
not more than one such atom for every two carbon atoms in
the chain. Thus, the non-skeletal valence bonds are
preferably carbon-to-fluorine bonds, that is, Rf is
preferably perfluorinated. The total number of carbon
atoms of Rf can Yary and can be, for example 1 to 18,
preferably 1 to 12. Where Rf is or contains a cyclic
structure, such structure preferably has S or 6 ring
15 member atoms, 1 or 2 of which can contain heteroatoms,
e.g., oxygen and/or nitrogen. Where Rf is aryl, it has 1
or 2 rings. Where Rf is an aromatic structure, the
aromatic structure may be substituted with lower alkyl
radicals (i.e., alkyl radicals having 1-4 carbon atoms).
20 Examples of such aryl radicals include perfluorophenyl
F F
F F
4-trifluoromethylphenyl, and perfluoronaphthyl. Rf is
also preferably free of ethylenic or other
carbon-to-carbon unsaturation, that is, it is a saturated
25 aliphatic or heterocyclic radical. Examples of useful Rf
radicals are fluorinated alkyl, e.g., -CF3, -C8F17 and
1~6~95
--6--
alkoxyalkyl, e.g., CF30CF2-, said radicals being
preferably perfluorinated straight-chain alkyl radicals,
CnF2n+l, where n is 1 to 12.
In the above formula, W is a polyvalent
connecting moiety. W has a valence of at least 2 and is
preferably selected from the group consisting of
carbon-to-carbon
o
single bonds, -CH2-0-CH2-, or -CH2-0-C-. The pendent
group -W - Rf ls herein sometimes referred to as ~the
pendent fluorocarbon substituent~, or the ~highly
fluorinated fluorocarbon substituent~. This latter term
is used especially when -W-~f and -Rf both are highly
fluorinated.
In reaction I above, catalysts may be employed
such as Lewis acids, optionally modified with organotin
compounds. Generally, the reaction may be run without
solvent at a temperature of about 25C to 150C. It is
~mportant to note at this juncture that the
fluorocarbon substituent of the epoxide (-W-Rf ln I)
becomes the pendent fluorocarbon-substituent of the novel
polyetherurethaneacrylates of the invention. Hence, in
this preparative route, the pendent fluorocarbon
substituent of the end product is determined by the
materials reacted in the first step.
II. Preparation of an isocyanate-term1nated
fluorocarbon-substituted polyethe~.
ll56795
--7--
The product of Step I is reacted with an organic
polyisocyanate Rl(NCO)p, p having a value of 2 to 4
according to the reaction:
o
R[(O-CH2-CH)mOH]n ~ nRl~NCO)p--~ R[(O-CH2-CH)mOCNH-Rl-(NCO)p_l]n II
W W
Rf Rf
Preparative Step II is generally discussed
below.
III. Preparation of the fluorocarbonacrylates.
The novel fluorocarbon-substituted polyetherurethane-
acrylates are prepared by reacting the product of Step II
wlth a hydroxyalkylacrylate according to the reaction:
O O
R~(OCH2-CH)mOCUH-Rl(UCO)p l]n ~ nHOR20CC=CH2 ~ ?
W R3
Rf
O O O
2 11
R[(OCH2-CH)mOCNH-R -(NHCOR OCCI-CH2)p-l]n III
W R
Rf
In the structural formulae of equations I, II
and III, R, Rf, Rl, R2, R3, m, n, p, and W are all
defined as above.
In an alternative route, the
fluorocarbonacrylates of the invention can be prepared by
1156795
--8--
the reaction of a hydroxyalkylacrylate with an oryanic
diisocyanate to form a polyisocyanatoalkylacrylate, viz.,
O O O
2 ~ 2 11
R (NCO)p+(p-l)HoR OC-C-CH2 OCN-R -(NHCOR OCf-CH2) IV
R
The product of I~ may then be reacted with a
fluorocarbon-substituted polyetheralcohol such as the
product of I above. Thiæ reaction may be written as
follows:
R[(OCH2-CH)mOH]n + nOCN-RltNH3OR2O3C-CH2)
W R
Rf V
O O O
~ 2 11
R[(OCH2-CH)mOCN-R ~NHCOR OC-C=CH2) ~n
P
W H R3
Rf
All symbols are defined as above.
It is also contemplated and often desirable to
20 modify the fluorocarbon-substituted polyetheralcohols of
Step I above, by copolymerizing the fluorocarbon epoxide
with one or more oxacycloalkanes which may or may not
have fluorine substituents,
Oxacycloalkanes (cyclic ethers) herein comprise
25 cycloaliphatic hydrocarbons having at least one oxygen
heteroatoms in the aliphatic ring. Oxacycloalkanes
. 115~7g5
- 9 -
polymerize by ring opening to polyethers. Particularly
useful oxacycloalkanes are the 2-, 3- and 4- carbon atom
(which ln conjunction with an oxygen heteroatom form 3-,
4- and 5 member rings) species known as oxiranes,
oxetanes and oxolanes. It has been found that the
fluorocarbon-substitued polyether alcohols (Equation I)
can be modified with up to about 80~ by weight
oxacycloalkanes which contain no fluorine.
Selectively incorporating oxacycloalkanes in
the fluoropolyetherurethaneacrylates provides a method to
control the optical characteristics of the finished
polymer. For example, decreasing the fluorine content of
the polymer by increasing the amount of oxacycloalkane in
the polyether chain, generally increases its refractive
lS index.
Suitable hydroxyl-containing materials which
can be used as initiators in step I preferably conta~n 1
to 6 hydroxyl groups and include water and monomeric or
polymeric aliphatic alcohols having 1 to 18 or more
carbon atoms. Examples of such aliphatic alcohols
include methanol, ethanol, 2-chloroethanol, isopropanol,
octanol-l, dodecanol, cyclohexanol, ethyleneglycol,
propyleneglycol, 1,3-butanediol,
3,4-dibromo-1,4-butanediol, 1,4-butanediol,
neopentylglycol, 1,6-hexanediol, 1,4-cyclohexanediol,
1,4-cyclohexanedimethanol, 2-(2-hydroxyethoxy~ethanol,
2-[2-(hydroxyethoxy)ethoxy]ethanol, 2-1[2-[2-(hydroxy-
795
--10--
ethoxy)ethoxy]ethoxy]]ethanol,3-(3-hydroxypropoxy)propanol, glycerol,
trimethylolpropane, pentaerythritol, dipenta- erythritol,
sorbitol, 1,1,4,4-tetrahydroperfluoro-
tetramethyleneglycol, 1,1,5,5-tetrahydroperfluoropenta-
methyleneglycol, and 1,1,6,6-tetrahydroperfluorohexa-
methyleneglycol and the monomeric alcohols described in
U.S. Patent 3,318,960. Preferred hydroxyl-containing
materials for use as initiators are the short chain
aliphatic terminal diols containing 4 to 6 methylene
groups such as 1,6-hexanediol and 1-4 butanediol.
Suitable polymeric aliphatic alcohols for use
in the present invention generally contain only carbon,
hydrogen and oxygen and have 1 to 6 hydroxyl groups. The
15 hydroxyl groups may be primary or secondary and generally
should be present to the extent of about one per thousand
units of molecular weight (l.e., a hydroxy equivalent
weight of less than 1000 is preferred). Polymeric
aliphatlc alcohols having a hydroxyl equivalent weight of
20 greater than about 1000 generally produce
polyetherurethaneacrylates having a ~luorine content
which is too low to exhibit the advantageous properties
of the present materials. Polymeric diols and triols
having a molecular weight of less than about 2000
25 (corresponding to a hydroxyl equivalent weight of 670 and
1000 for triols and diols respectively) constitute a
preferred class of polymeric aliphatic alcohols.
1 1~6795
--11--
Other useful polymeric aliphatic alcohols
include polyester polyols, such as the lactone polyester~
described in U.S. Patent 3,169,945 (especially the
polyesters terminated with two or more hydroxyl groups
formed by reaction of epsilon-caprolactone and polyol),
the hydroxyl-terminated polyester condensation polymers
described in U.S. Patent 3,641,199, the substantially
linear, saturated, hydroxyl-terminated polyesters
described in U.S. Patent 3,457,326, the
hydroxy-containing polyesters described in U.S. Patent
3,931,117, and the hydroxy- terminated block polymers of
polyethers and polyesters described in U.S. Patent
3,960,572. Useful polyether block polymers include the
hydroxy-terminated polyether condensation polymers
described in U.S. Patent 3,641,199, the substantially
linear, saturated hydroxy-terminated polyethers described
in U.S. Patent 3,457,326, the polyalkylene ether polyols
described in U.S. Patents 3,499,852, 3,697,485 and
3,711,444, and the polyetheylene glycol and polypropylene
20 glycols described in V.S. Patent 3,850,770. Useful
polyolefin polyols include those described in U.S. Patent
3,678,014 and the ~ diols from ethylene described in
J. Pol~mer Science, Part A-l, Vol. 5, p. 2693 (1967). A
particularly useful, commercially available class of
25 caprolactone polyols which can be used are those sold
under the Trademark ~NIAX,- such as PCP-0200, PCP-0210,
PCP-0230 and PCP-0300 (e.g., see technical bulletin
7~5
-12-
F42464 of Union Carbide Corp.).
Other useful hydroxyl-containing materials
whlch can be utilized as initiators in I include
polysiloxane polyols such as the hydroxy-terminated
diorgano-polysiloxanes described in U.S. Patents
4,098,742 and 3,886,865, and the siloxanes having a
reactive hydroxyl-functional group bonded to at least two
of its silicon atoms, described in U.S. Patents
3,577,264, 3,976,676 and 4,013,698.
Suitable epoxide-containing compounds having
pendent highly fluorinated fluorocarbon substituents
(which become W-Rf in the finished polymer) are the
fluoroaliphatic glycidyl ether compounds including
perfluoroalkyl glycidyl ethers such as perfluoroisopropyl
glycidyl ether whose preparation is described in U.S.
Patent 3,361,685; the 1,1, -trihydrofluoroalkyl glycidyl
ethers such as the 1,1,3-trihydrotetrafluoroethyl
glycidyl ether whose preparation is described in U.S.
Patent 3,417,035; the l,l-dihydroperfluoroalkyl glycidyl
ethers such as l,l-dihydrotrifluoroethyl glycidyl ether,
l,l-dihydropentafluoropropyl glycidyl ether,
l,l-dihydroheptafluorobutyl glycidyl etherr
l,l-dihydropentadecafluorooctyl glycidyl ether,
l,l-dihydrohepadecafluorononyl glycidyl ether and others
25 whose preparation 1s described in U.S. Patent 3,591,547;
and the glycidyl perfluoroalkanoates such as glycidyl
perfluoroacetate, glycidyl perfluoropropionate, glycidyl
115G795
-13-
perfluorobutyrate, and glycidyl perfluorooctoate which
are prepared by the esterification reaction of glycidol
and the corresponding perfluoroalkanoic acids and the
glycidyl ethers of fluorinated phenols such as
perfluorophenyl glycldyl ether and trifluoromethylphenyl
glycidyl ether.
Examples of oxaheterocycles that can be
copolymerized with the fluorocarbon substituted epoxides
for preparing the fluorocarbon alcohols and polyols
lnclude ethylene oxide; alkyl-substituted ethylene
oxides, e.g., propyleneoxide, epichlorohydrin,
butyleneoxide alkenyl- substituted ethylene oxides,
e.g., butenyloxide; aryl- substituted ethylene oxides,
e.g., styreneoxide, benzylethylene oxlde; glycidyl
ethers, e.g., methyl glycidyl ether, butyl glycidyl
ether, phenyl glycidyl ether, 3-phenylpropyl glycidyl
ether, cyclohexyl glycidyl ether; cycloalkyl oxides,
e.gO, cyclohexene oxide, cyclopentene oxide and limonene
oxide; oxetanes, e.g., oxetane and 2,2-dimethyl oxetane;
and the oxolanes, e.g., tetrahydrofuran. Other suitable
copolymerizable epoxides and glycidyl ethers are
disclosed in U.S. Patent 3,417,035 among others.
The preerred catalysts for preparing the
fluorocarbon alcohols and polyols (I, above) are the
catalyst systems comprising: (1) a fluorinated acld
selected from bis(fluorinated aliphatic sulfonyl)alkanes,
fluorinated aliphatic sulfonic acids, and Lewis acid of
1 15~7~5
the formula H X Fb+a where X may be aluminum, boron, phosphorus,
arsenic, tin, antimony and the like; b is the highest oxidation
number of X and a is 0 or 1; and (2) a polyvalent tin compound as
are taught in assignee's copending Canadian application No. 326,143,
entitled "Colorless Hydroxyl-terminated Poly(chloroalkylene
ethers)", filed on April 23, 1979 clai~ing a U.S. priority date of
May 17, 1978 in the name of Chung I. Young and Loren I. Barber,
Jr. Many other catalysts are useful for preparing the fluorocarbon
alcohols by cationic polymerization techniques. Useful Lewis acid
10 catalysts are disclosed in U.S. Patents 3,269,961; 3,850,856;
3,910,878; 3,910,879; and 3,980,579 among others. Useful aluminum
alcoholate catalysts are disclosed in U.S. Patent 3,318,960 and the
use of diethyl zinc to polymerize glycidyl ethers is disclosed in
U.S. Patent 3,361,685.
The fluorocarbon alcohols are prepared in accordance with
Equation I by adding one to 20 mole equivalents of fluorocarbon
epoxy compound to one hydroxyl equivalent of hydroxyl-containing
initiator compound. The temperature and time required for the
reaction will vary depending on the particular reactants and amounts
employed and on the nature and amount of catalyst used. Generally,
temperatures from about 20C to 200C for periods up to 24 hours
suffice for the reaction. The catalyst concentration for the pre-
ferred fluorinated acid/organo tin compound can be from about
~ 14 -
,A ~
I 1 ~ 6 7 9 ~
-15--
0.1% to about 1% of the total weight of reactants.
Generally, the higher the catalyst concentration, the
lower the temperature and shorter the time required for
the reaction. An inert organic solvent such as
dichloromethane or chloroform may be employed to
facilitate the reaction.
Polyisocyanates useful for preparing the
fluorocarbon acrylates can be aliphatics, cycloaliphatic
or aromatic, Exemplary diisocyanates are disclosed in
U.S. Patents 3,641,199; 3,700,643; 3,960,572 and others.
Preferred polyisocyanates are the cycloaliphatic and
aromatic diisocyanates of which isophorone diisocyanate
and toluene diisocyanate ~tolylene-2,4-diisocyanate) are
the most preferred.
An exemplary list of hydroxyalkylacrylates
useful for preparing the polyetherurethaneacrylates is
disclossd in U.S. Patent 3,577,252. Other desirable
compounds include hydroxyalkylpolyacrylates such as
trimetholylpropanediacrylate and
pentaerythritoltriacrylate.
The reaction of the fluorocarbon alcohol,
diisocyanate, and hydroxyalkylacrylate to form the
polyetherurethaneacrylate in accordance with Equations II
and III or IV and V is performed in sequential steps at
temperatures from about 20C to 100C for about 10
minutes to several hours,sufficient to bring about the
reaction. Preferably, a tin catalyst such as diphenyl
1 15~'~9S
16-
dibutyl tin dilaurate is used to promote the reaction~
Other sultable catalysts include compounds containing
tertiary amino groups, and titanium compounds.
Generally, the catalyst is included to the extent of
about 0.01 to about l.S percent of the total weight of
reactants.
Depending on the use to which the fluorocarbon
acrylates are to be put, various materials can be added
including curing catalysts, fillers, extenders, pigments
and dyes.
Generally, diluent monomers are added to
fluorocarbon-substituted polyetherurethaneacrylates of
the }nvention to reduce their viscosity and increase or
decrease their curlng rate. Amounts of the diluent
monomer up to 2 or more times the weight of the
polyetherurethaneacrylate present may be employed. A
suitable diluent monomer is any ethylenically unsaturated
monomer that is compatible and copolymerizable with the
polyetherurethaneacrylates of the invention. Suitable
ethylenically unsaturated monomers include acrylic acid,
acrylates and acrylate esters such as methyl
methacrylate, ethyl acrylate, 2-ethylhexyl acrylate,
cyclohexyl acrylate, styrene and its derivatlves such as,
2-chlorostyrene, 2,4-dichlorostyrene, acrylamide,
25 acrylonitrile, t-butyl acrylate, methyl acrylate, butyl
acrylate, 2-(N-butylcarbamyl)ethyl methacrylate and
2-(N-ethylcarbamyl)ethyl methacrylate,
1 156795
-17-
N~vinyl-2-pyrrolidone. Especially desirable dilutent
monomers are the acrylic acid and methacrylic acid esters
of l,l-dihydroperfluoroalkanols such as
2,2,2-trifluoroethyl acrylate, l,l-dihydroperfluoropropyl
methacrylate, l,l-dihydroperfluorobutyl acrylate and
l,l-dihydroperfluorooctyl methacrylate. Other diluent
monomers that can be incorporated into the composition of
the invention to increase the cross-link density include
1,4-butylene dimethacrylate or acrylate,
1,1,6,6-tetrahydroperfluorohexanediol diacrylate,
ethylene dimethacrylate, glyceryl diacrylate or
methacrylate, glyceryl triacrylate or trimethacrylate,
pentaerythritol triacrylate or trimethacrylate, diallyl
phthalate, dipentaerythritol pentaacrylate,
neopentylglycol triacrylate and 1,3,5-tri(2-
methacryloxyethyl)-s-triazine.
Suitable catalysts or initiators for use in
polymerizing (curing) the compositions of the invention
are catalysts which liberate or generate free-radicals
upon addition of energy in the form of radiation such as
heat, actinic light or electron beam. Such catalysts are
well known and are described frequently in the
polymerization art, e.g., Chapter II of ~Photochemistry~
by Calvert and Pitts~ John Wiley & Sons (1966).
Included among free radical catalysts are the
conventional heat activated catalysts such as organic
peroxides and organic hydroperoxides; examples are
115~7~5
benzoyl peroxide, tertiary-butyl perbenzoate, cumene
hydroperoxide, azobis(isobutyronitrile) and the like~
The preferred catalysts ara photopolymerization
initiators which facilitate polymerization when the
composition is irradiated. Included among such
initiators are acyloin and derlvatives thereof, such as
benzoin, benzoin methyl ether, benzoin ethyl ether,
benzoin isopropyl ether, benzoin isobutyl ether, and
~-methylbenzoin; diketones such as benzil and diacetyl,
etc.; organic sulfides such as diphenyl monosulfide,
diphenyl disulfide, decyl phenyl sulfide, and
tetramethylthiuram monosulfide; S-acyl dithiocarbamates,
such as S-benzoyl-N,N-dimethyldithiocarbamate; phenones
such as acetophenone, a,a,~-tribromacetophenone,
15 a, a-d i ethoxyacetophenone,
o-nitro-~ -tribromoacetophenone; benzophenone, and
p,p'-tetramethyldiaminobenzophenone; sulfonyl halides
such as p-toluenesulfonyl chloride, l-naphthalenesulfonyl
chloride, 2-naphthalenesulfonyl chloride,
1,3-benzenedisulfonyl chloride, 2,4-dinitrobenzene-
sulfonyl bromide and p-acetamidobenzenesulfonyl
chloride. Normally, the initiator is used in amounts
ranging from about 0.01 to 5% by weight of the total
polymerizable composition. When the quantity is less
than 0.01% by weight, the polymerization rate becomes
extremely low~ If the initiator is used in excess of
about 5% by weight, no correspondingly improved effect
' ~1567g~
can be expected. Preferably, about 0.25 to 1.0~ by
weight of initiator is used in the polymerizable
compositions. As noted above, a catalyst is not
necessary when cure of the present materials is
undertaken by such curing techniques as electron beam.
The advantages and benefits of the compositions
o the invention will be described in the following
illustrative examples wherein the term aparts~ refers to
parts by weight unless otherwise indicated. In the
examples, the polyetherpolyols having pendent
fluorocarbon groups were prepared according to the
following general procedure.
The fluorocarbon alcohols were prepared in
glas~ reactlon flasks equipped with a stirrer,
thermometer and a dropping funnel. A dry atmosphere was
maintained within the flask during the reaction.
In each preparation, the hydroxyl-containing
material (generally, about 0.1 mole) and 0.3 weight
percent of a catalyst system of both
bis(trifluoromethylsulfonyl) phenylmethane,
(CF3~02)2cHc6H5~ and dibutyldiphenyltinJ
(C6Hs)2(C4Hg)2Sn, were charged into the flask and heated
to 80C while stirring. The fluorocarbon epoxide and,
where used, a copolymerizable oxacycloalkane (e.g.,
non-fluorine- containing oxira~e, oxetane or oxolane)
were then charged dropwise over a period of 0.5 to 1 hour
to the stirred and heated flask. The resulting mixture
1 15~J,795
-20-
was stirred at atmospheric pressure at 50C to 125C
until the reaction was substantially complete, generally
8 to 24 hours. Then the reacted compositions were heated
at about 80C under about 0.5 Torr for a period of time
sufficient to remove volatile components. The ratio of
the moles of initiator hydroxyl compound to the moles of
fluorocarbon epoxide and oxacycloalkane (where used) was
varied to control the hydroxyl equivalent of the product
fluorocarbon alcohol.
EXAMPLES 1-21
In accordance with the general procedures
given above, various fluorocarbon alcohols were prepared.
The initiator alcohol, fluorocarbon epoxide, mole ratio
of alcohol to epoxide, reaction temperature and ratio of
moles of bis(trifluoromethylsulfonyl)phenylmethane
(commercially referred to as phenyl disulfone, or 0DS) to
moles of dibutyldiphenyltin in the catalyst system are
given in Table I. Also given are the percent of epoxide
convers1On, the hydroxyl equivalent weight, the
polydispersity (p= the ratio of weight average to number
average molecular weight), and the values of m and n in
the general formula of the product alcohol. Also given
in Table I are the glass transition temperature, Tg, the
melting point, Tm~ and the refractive index of the
product fluorocarbon alcohol.
The polydispersity was determined by gel permea-
tion chromatography using a Waters, Associates
1 1~67~S
-21-
chromatograph with a microstyrogel column. The hydroxy
equivalent weights were obtained by reacting the hydroxyl
group with phenylisocyanate, adding amine to remove the
excess phenyl isocyanate and titrating the excess amine
with dilute hydrochloric acid. The value of m was found
by calculation from the hydroxyl equivalent weight. The
Tg and Tm were measured using differential thermal
analysis (using the 900 DTA differential thermal-analyzer
and instructions available from the E.I. duPont deNemours
and Company). The refractive indices were determined on
a Rarl Zeiss refractometer.
1 15~9~
--22--
o B
2~.~ ~
~ r ~ ~ O y~ r
_ ,~
~ O~ N C~ ~!! ~ O
~ ~ ~ ~ ~ + ,~
~ ~ ~ r~7 ,r, U') ~ N N C~
T ~ ~ T
~v ~ ~ 9
~ N
~ r ~ T ~N r r r ~ ~
o O O ~ ; o N
.5 O ~ ~ o ~ æ
10 G _ æ ~ 0~
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115~3795
-24-
The following additional examples illustrate the
preparation of the fluorocarbon substituted
polyetherurethane acrylates of the invention.
EXAMPLE 22
Thirty grams of the fluorocarbon polyol of
Example 2 was mixed wlth one equivalent (7.50 g) of
distilled isophorone diisocyanate until thoroughly
blended. The mixture was roll milled until the infrared
spectrum of the mixture no longer exhibited an absorption
peak at 3.10 micrometers attributable to hydroxyl
functionality (about two hours). One equivalent (4.40 g)
distilled 2-hydroxyethyl methacrylate was then added to
the mixture and roll milling continued until the infrared
spectrum no longer exhibited an absorption peak at 4.2
mlcrometers attributable to isocyanate funct~onality, but
exhibited a peak at 5.84 micrometers attributable to
urethane functionality (about two hours). The
fluorocarbonetheracrylate obtained was a clear, very
viscous oil having a structure that was essent1ally:
CH3
~CH2~6 [~0CH2CH ) 20CNH~CH3
CIH2~ ~H3 e e
OH3C CH2-NHCO~CH2)2OCC=CH2]2
2 7 15C~3
To ten parts of the fluorocarbon etheracrylate
obta~ned above was added and thoroughly mixed one part by
weight of l,l-dihydroperfluorooctyl methacrylate to reduce
1 156795
-25-
the viscosity of the mixture and 0.01 part of diethoxy-
acetophenone as actinlc light or photoinitiator. The
mixture was cast as a 140 micrometer thick layer between
two sheets of 50 micrometer polyester. Upon exposure to
the radiation from a xenon/mercury arc lamp, the layer
cured within one mlnute to a tough, flexible, clear film
having a refractive index of 1.402, a tensile strength of
85.4 kg/cm2 (1200 p5i) ~ and an elongation at break of
9.4%.
EXAMPLES 23-25
The procedure of Example 22 was followed with
the exception that different fluorocarbon polyols from
Table 1 were employed. The results of these further runs
are summarized in Table 2. Isophorone diisocyanate,
2-hydroxyethylmethacrylate, and diethoxyacetophenone
photoinitiator were employed as in Example 22.
l 15~795
--26--
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115~795
2~-
EXAMPLES 26-29
The procedure of Example 22 was followed with
the exception that the preparation of the highly
fluorinated fluorocarbon substituted
polyetherurethaneacrylate was accomplished by heating the
reaction mixture with an infrared lamp on a roll mill.
The results of these runs are summarized ln ~able III.
9 51
-2(`
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-29-
EXAMPLE 30
A fluorocarbonpolyeth~erurethaneacrylate was
prepared by mixing on a roller mill for about two hours a
mixture of 20 part~ of the fluorocarbon diol of Example 2
and 3.19 parts of isocyanatoethyl methacrylate (available
from Dow Chemical Company). The resultlng compound had an
infrared absorption peak at 5.84 micrometers attributable
to urethane functionality. A cured film prepared wlthout
addition of diluent monomer had a refractive index of
1 388, a tensile strength of 60 kg~cm2 (850 psi) and an
elongation at break of 2~
EXAMPLE 31
Ten parts of fluorocarbonetheracrylate as
described ~n Example 2 was diluted with 3 parts by weight
of l,l-dihydroperfluorooctyl methacrylate and polymerized
as a film that had an index of refraction of 1.408, a
tensile strength of 133 kg/cm2 (1900 psi) and an
elongation at break of 36%.
EXAMPLE 32
When ten parts of fluorocarbonetheracrylate as
described in Example 22 were diluted with five parts by
weight of l,l-dihydroperfluorooctyl methacrylate and
polymerized, a film was obtained having an index of
fraction of 1.397, a tensile strength of 78.4 kg/cm2 (1120
psi) and an elongation at break of 82~.
i7~
-30--
EXAMPLE 33
The fluorocarbonetheracrylate prepared in
Example 22 was diluted with 10% by weight of the acrylate
ester rather than the methacrylate ester of l,l-dihydro~
perfluorooctyl alcohol and cast as a 140 micrometers thick
film between two sheets of polyester film. The cured film
obtalned had a refractive index at 25C of 1.413, a
tenslle strength of 78.4 kg/cm2 (1120 psi) and an
elcngation at break of 29~.
EXAMPLE 34
The procedure of Example 22 was followed with
the exception that an equivalent weight of tolylene-2~4-
diisocyanate was used in place of isophoronedilsocyanate.
The fluorocarbonetheracrylate obtained had an infrared
spectrum consistent with a structure that was essentially:
O O O
Il 11 11
tCH2t6[tOCH2CH ~ OCNH ~ NHC(CH2)2CC=CH2
CIH2 CH3
o
CIH2C7F15
On polymerIzation of the fluorocarbonether-
acrylate without use of a diluent monomer, a cured film
having a refractive index at 25C of 1.408, a tensile
strength of 65 kg/cm2 (928 psi), and an elongation at
break of 42~ was obtained.
115~
-31-
Example 35
~ rapidly photocuring system comprislng
fluorocarbonetheracrylates was formulated by mxing 4
grams of the fluorocarbonetheracrylate as described in
Exampla 2 with 2 grams of l,l-dihydroxyperfluoro-
octylacrylate, 2 gram~ of 1,6-tetrahydroperfluoro
hexanediol diacrylate, 0.8 gram N-vinyl-2-pyrrolidone and
0.5 gram diethoxyacetophenone. This formulation was
coated onto poly(vinylchloride~ film. Vpon exposure in
air to ultravlolet radiation of 1 joule/cm2 from two
200-watt medium pressure Hanovia mercury lamps, the
formulation cured in 0.5 second to form a clear tough
coating.
Example 37
A sample of the fluorocarbonetheracrylate system
described in Example 22 was coated onto a sheet of 2
mil(50 micrometer) polyester film using a ~14 wire-~ound
bar. A thin sheet of 0.5 mll polyimide was rolled over
the coating with a printing rollerO The sample was
irradiated in an electron beam at 1.05 KV and 2.5
milliamps for 8 seconds. The coating was completely cured
after this exposure.
Example 3~
A l-gram sample of the fluoroca~bonetheracrylate
system described in Example 22 was mixed with 25 mg AIBN
~azobisisobutyronitrile) with gentle heating until the
7~5
-32-
initiator was dissolved. A 5.4-mll (140-mlcrometer)
coating was cast between two layers of 2-mil
(50-micrometer) polyester. The sample was cured at 65C
for 15 hours, after which time the sample was cured.
