Note: Descriptions are shown in the official language in which they were submitted.
Z~i8
Background of the Invention
Field of the Invention;
This invention relates to the production of radiation curable microcapsu-
lar coating co~positions. In particular, it relates to the production of micro-
capsules containing a hydrophobic liquid core by polycondensation polymerizationof tw~ w~ forming materials in a hydrophilic liquid continuous phase wherein
the hydrophilic liquid cc~orises a polar radiation curable compound. In one
em}od1ment of this invention, the encapsulated hydrophobic liquid contains a
chromogenic material soluble in the encapsulated hydrophobic liquid. A disper-
sion of these microcapsules containing a chramcgenic material can be coated on
a substrate and cured by radiation to give a pressure-sensitive carbonless ccpy
` sheet having a transfer coating.
` Prior Art:
The production of microcapsules containing an encapsulated oily (hydropho-
i ~
~ 15 bic) liquid wherein the microcapsule walls are produced b~ a polycondensation
reaction of polyisocyanate and a second w~ forming material is described in
U. S. Patent No. 3,796,669 to Kiritani et al~ Both the polyisocyanate ~all-
;:~
~` forming ma~rial and the second wall-forming material are mlxed with oily liquid.
m e mixed oily liquid is dispersed into an aqueous continuous phase and the
tem~2rature is raised to initiate the reaction on the surface of the oil drops
to encapsulate the oil drops with the reaction produc~ of the polyisocyanate
and second wa~l-fo~ming material. A catalyst for the reaction may also be
added to the oily liquid.
A number of patents disclose the production of microcapsules using inter-
facial condensation polymerization of two or m~re reactants to form the micro-
capsule walls. Typical of ~hese c~re:
U. ~. Patent 3,429,827 (1969) to Ruus
U. S. Patent 3,432,427 (1969) to Xan et al
U. S. Patent 3,464,926 (1969) to Vande~aer et al
U. S. Pat nt 3,492,380 (1970) to Santo et al
U. S. Patent 3,575,882 (1971) to Vandegaer et al
U. S. Pat~nt 3,577,515 (1971) to Vande~aer
~ ~ ~ 3 ~
U. S. Patent 3,607,776 (1971) to Santo et al
U. S. Patent 3,726,804 (1973) to Matsukawa et al
U. S. Patent 3,875,074 (1975) to Vassiliades et al
It is im?ortant to note that none of the above listed patents or U. S.
Patent 3,796,669 to Kiritani disclose the in situ preparation of the micro~ap-
sules in a radiation curable hydrophilic liquid contai~ing a radiation curable
polar compound.
Carbonless copy paper, briefly stated is a standard type of paper wher2in
during manufacture the backside o~ the paper substrate is coated with ~hat is
referred to as a CB or transfer coating, the CB coating containing one or ~ore
chrcmcgenic materials, generally in capsular form. At the same time the front
; side of the paper substrate is coated during manufacture with what is referred
to as a CF coating, ~hich contains one or more chrcmogenic materials capable
of producing a color with encapsulated CB chromogenic material. Both the
chromogenic materials remain in the coatings on the respective back and front
surfaces of the paper in substantially colorless form. Ihis is ~rue until the
CB and CF coatings are brought into overlying relationship and sufficient pres-
sure, as by a typewriter, is applied to rupture -the CB coating to release the
encapsulated chrcmogenic material. At this ~ime the chrQmogenic material con-
tacts the CF coating and reacts with the chromogenic material therein to ~orm
a colored image. Carbonless copy paper has proved to ~e exceptionally valuable
image transfer ~dia for a variety of reasons~ only one of which is the fact
that until a CB coating is placed next to a CF coating both the CB and CF coat~
ings are in an inactive state as the coreactive elements are not in contact
~ith one another until pressure is applied. Patents r~lating to carbonless copy
paper products are:
U. S. Patent 2,712,507 (1955) to Green
U. S. Patent 2,730,456 (1956) to Green et al.
U. S. Patent 3,455,721 (1969) to Phillips et al.
U. S. Patent 3,466,184 (1969) to Bowler et al.
U. S. Patent 3,672,935 (1972) to Miller e-t al.
U. S. Patent 3,720,623 (1973) to Cartmell et al.
A disadvan-tage of coated paper products such as carkonless transfer
papers stems from the necessit~ of applying a liquid coating ccmposition con-
taining the color forming ingredients during the rnanufacture process. In the
application of such coatings, volatile organic solvents are sometimes used
which then in turn requires evaporation of excess solvent to dry the coating
thus producing volatile solvent vapors. An alternate method of ooating involves
the application of the color forming ingredients in an aqueous slurry reguiring
removal of water by drying. Both methods suffer from serious disadvantages.
In particular, the organic solvent coating method necessarily involves the
,
prc~uction of generally volatile solvent vapors, creating both a health and
fire hazard in the surrounding en~ironment. When using an aqueous solvent
system the large amounts of water must be evaporated since the microcapsule
ooatings currently used cc~mercially generally comprise 60% to 85% water.
This invol~es the expenditure of significant a~ounts of energy and further
necessitates a separate drying step which rli!~res the use of cc~plex and
expensive apparatus to continuously dry a substrate whi~h has been coated with
such aqueous coating ccmpositions.
Radiation curable coating ccmpositions and methods of producing these
co~lpositions are ~7ell known, although their use is not well known in the produc-
tion of carkonless papers. In general, patents concerned with the production
and application of liquid resin campositions containins no volatile solvent
which are subsequ~ntly polymerized by free radical radiation to a solid film
are:
Z~
U. S. Patent 3,551,235 (1970) to Basse~ir e-t al.
U. 5. Patent 3,551,246 (1970) to Bassemir et al.
,! U. S. Patent 3,551,311 (1970) to Nass et aL.
,,:
U. S. Patent 3,558,387 (1971) to Bassemir et al.
U. S. Patent 3,661,614 (1972) to Bassemir et al.
' U. S. Patent 3,720,534 (1973) to Macaulay et al.
U. S. Patent 3,754,966 (1973) to Newman et al.
: .
; ~ U. S. Patent 3,772,062 (1973) to Shur et al.
U. S. Patent 3,772l171 (1973) to Savageau et al.
U. S. Patent 3,801,329 (1974) to Sandner et al.
U. S. Patent 3,819,496 (1974) to Roskott et al.
U. S. Patent 3,847,768 (1974) to Kagiya et al.
U. S. Patent 3,847,769 (1974) to Garratt et al.
These CQmpositiQns generally also contain a pigm~nt or dye. Such resin
compositions are useful for protective coatings and fàst drying inks. U. S.
Patent 3,754,966 describes the production of an ink releasing dry transfer
element which can be used as a carbon paper or typewriter ribbon. Additionall~
it is known to use such radiation in the formation and hardening of microcaps~Les
although none of these microcapsules are kno~n to have utility in the car~onlesspaper environment. Patents knc~ to use radiation in the preparation of-micro--
capsules æ e:
; U. S. Patent 3,242,051 (1966) to Hiestand et al.
U. S. Patent 3,265,630 (1966) to Jensen
U. S. Patent 3,405,071 (1968) to Reyes
U. S, Patent 4,021,364 (1977) to Speiser et al.
It is significant to note that the encapsuLated materials disclosed in
any of the above patents do not include oil solutions of colorless dyes. It is
particularly significant in view of the fact that the radiation cured coating ofthe instant invention mu~st be compatible with the reaction of CB and CF chrcmo-genic ma-~erials to form a color in order to have utility in the car onless
paper environment. Such color forming reactions are g~erally of a sensitive
or delicate nature and are not generally ccmpatible with the compositions
found in the prior art. For instance, it is known that certain
color precursors currently used in the commercial production o~
carbonless transfer sheets will undergo a color change when
exposed to ultraviolet radiation.
The present invention provides a radiation cura~le
liquid coating composition for use in the manufacture of micro-
capsule coated papers, said liquid coating composition being
characterized by being curable by radiation to a dry, solid,
tack-free resin, said ra~iation being a combination of ultra-
violet radiation and infra-red radiation, said li~uid coating
composition being further characterized by containing micro-
capsules having a hydrophobic core material, said microcapsules
being dispersed in a radiation curable hydrophilic liquid, said
hydrophilic liquid comprising water and at least one polar
radiation curable compound, said liquid coating composition
additionally containing a photoinitiator.
The microcapsular coating compositions of the instant
invention have a significantly lower water content than the -~
microcapsular coating compositions currently used in the prepa-
ration of carbonless transfer papers. For example, prior art
coating compositions containing gelatin are seldom applied at
a water content below 80% (20% solids). In comparison with a
microcapsular coating composi~ion con~aining 40% water (60%
solids) produced by the process of this invention, the amount
of water necessary to be evaporated from the prior art compo-
sitions is 6 times the amount to be evaporated from the coating
compositions of this invention. By using the coating composi-
tions of this invention, a substantial reduction in heat energy
used in drying can be realized. Another advantage is that by
using available sources of ultraviolet radiation which also
contains infra-red radiation such as the radiation from a
mercury vapor lamp the microcapsular coating compositions may
be cured in one combined polymerization and drying step, thus
,,/~,
~,~ ..,,;, ~
eliminating the need for additional or separate drying.
This invention relates to a process for producing a
liquid coating composition for use in the manufacture of
~i pressure-sensitive carbonless transfer papers, said li~uid
` coating composition being characterized by being curable by
radiation to a dry, solid, tack-free resin, said radiation
being a combination oE ultraviolet radiation and infra-red
. radiation and said liquid coating composition being further
characterized by containing microcapsules having a hydrophobic
`~ 10 core material, comprising the steps of:
~ a) preparing an emulsion containing droplets of hydrophobic~
emulsion component dispersed in a hydrophilic emulsion compo-
nent, said hydrophobic emulsion component comprising a hydro-
phobic liquid, said hydrophobic emulsion component additionally
containing a first wall-forming material capable of reacting
by condensation polymerization with a second wall-forming
material to form a polymeric capsule wall, said first wall-
forming material being soluble in said hydrophobic emulsion
component, said polymeric capsule wall being substantially
insoluble in said hydrophilic and said hydrophobic emulsion
components, said hydrophilic emulsion component comprising an
emulsifier dispersed in a radiation curable hydrophilic liquid,
said radiation curable hydrophi]ic liquid comprising water and
at least one radiation curable polar compound, said emulsion
additionally containing said second wall-f~rming materials;
b~ subjecting said emulsion, with mixing, to temperature con-
ditions for a period of time sufficient to substantially com~
pletely polymerize said first and second wall-forming materials
thereby forming a dispersion of microcapsules in said hydro-
philic emulsion componen~, said microcapsules having capsulewalls substantially impermeable to said hydrophilic and said
hydrophobic emulsion components; and
c) adding a photoinitiator to said dispersion of microcapsules.
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.:
DETAILED DESCRIPTION OF THE INVENTION
~` The coating compositions produced by the process
~ of this invention are essentially dispersions of microcap-
'~ sules containing a hydrophobic liquid core material in a
` radiation curable hydrophilic liquid as a continuous phase.
The dispersions of microcapsules are prepared in situ in the
radiation curable hydrophilic liquid by a condensation poly-
merization reaction of a first wall-forming material and a
second wall-forming material. The coating compositions can
be applied as a coating to a substrate such as paper or
plastic film and can be cured by radiation to a tack-free
resinous film. If the mi~rocapsules contain a chromogenic
material, the coated pape~ is useful as a pressure-sensitive
carbonless transfer CB paper. For purposes of this inven-
tion, the term "chromogenic" shall be understood to refer
to materials such as color precursors, color developers,
and color formers.
The coating composition can contain additional
materials which function as photoinitiators. Addition of
these materials depends upon the particular method of curing
; the microcapsular coating. Filler materials can also be
added to modify the properties of the cured film. Although
the product and process o~ this invention are useful in the
manufacture of a variety of microencapsulated products, such
as, for example, microencapsulated flavors, foods, pharma-
ceuticals, insecticides and the like, the preferred use of
the process and product of this invention is in the produc-
tion of a pressure-sensitive carbonless transfer sheets such
as is described in commonly-assigned U. S. Patent 4,091,122
issued on May 23, 1978.
The hydrophobic liquids useful in the process o~
this invention are the non-polar oils and solvents. In the
preferred use of this invention, i.e. to prepare pressure-
Y~ ) , _g_
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sensitive carbonless transfer sheets, the preferred hydro-
phobic liquids are monoisopropybiphenyl (MIPB), chlorinated
paraffins, alkylnaphalenes, kerosene, petroleum naphtha and
mixtures thereof.
The chromogenic materials useful in the practice
of this invention are the electron-donor type color precur-
sors. These include the lactone phthalides, such as crystal
violet lactone, and 3,3-bis-(1'-ethyl-2-methylindol-3'yl)
phthalide, the lactone fluorans, such as 2-dibenz.ylamino-6-
10 diethyl- ................. ~
~ t -9a-
~":
amlno-fluoran and 5-diethylc~mino-1,3-dimethylfluoran, the lactone xanthenes,
the leucoauramines, the 2-(omega substituted vinylene)-3,3-disubsti-tuced-3-H
indoles and 1,3,3-trialkylindolinospirans. Mixtures of these color precursors
can be used if desired. The color precursors are soluble in the hydrophobic
liquid and are preferably present in such solutions, somet~mes referred to as
carrier oil solutions, in an a~Dunt of from about 0.5% to about 20.0% based
on the weight of the oil solution, and the most preferred range is ~rom about
2% to about 7%.
The radiation curable hydr~philic liquids useful in the practice of this
invention ccmprise the free radical polymeriza~Le ethylenically unsaturated
organic compounds in water solution. These compounds contain at least one
terminal ethylenically unsaturated group per molecule. These cc~pounds ar2-
radiation curable polar compounds and their aqueous solutions function in part
as the continuous hydrophilic phase during the in situ preparat,ion of the
microcapsules and as a dispersing medium for the microcapsules and other
ingredients of the coating composition prior to the coating operation. They
are curable to a solid resin when exposed in the presence of a photoinitiator
to ultraviolet radiation containing additionally some infra-red radiation. The
cured resin acts as a binder for the microcapsules to a substrate such as pa~er.
E~amples of useful radiation curable polar compounds are N-vinyl-2-
pyrrolidonel acrylamide, h~droxyethyl acrylate, hydroxypropyl acrylate~ diaoe tone
acrylamide, 2-acrylamido-2-methylpropanesulfonic acid, acrylic acid, polyethylene
glycol monoacrylates~ polye-thylene glycol polyacrylates, polyvinyl alcohol
acrylate, starch acrylate, cellulose acrylate, quaternary ammonium salt deriva-
25 tives of dimethyl2m moeth~l acrylate and methacrylate and muxtures thereof. The
abo~e radiation curable polar ocmpounds are liquids. ~owever, solid radiation
curable polar com~ounds, such a N-methylol acrylamide, can ke dissolved in ~ater
and used as the radiation curable hydrophilic liquid. The preferred polar
compounds are ~-methylol acrylamide and hydroxyethyl acryla~e.
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The first wall-forming material is soluble in and
forms a part of a hydraphobic emulsion component. It may
be either a polyisocyanate or a polyacid halide compound.
The polyisocyanates useful in this invention are the ali-
phatic and aromatic polyisocyanates which include, for example,
(a) diisocyanates, such as m-phenylmethane-4,4'-diisocyanate;
(b) triisocyanates, such as toluene-2,4,6-triisocyanate; (c)
tetraisocyanates, such as 2,2,5,5- tetraisocyanate; (d)
isocyanate prepolymers produced and sold by Mobay Chemical
Company, Pitt~burg, Pennsylvania, Mondur C~-75* (75~ of a
high molecular weight adduct of toluene isocyanate and 25%
of ethyl acetate produced and sold by Mobay Chemical Company)
DesmodurN-100* (a biuret oontaining aliphatic isocyanate
also produced and sold by Mobay Chemical Company) and NIAX
SF-50* (a trifunctional aromatic polyurethane prepolymer
having a free isocyanate content of 32.5~ made and sold by
Union Carbide Corporation, New York, N.Y.). Mixtures of
these compounds may be used.
The polyacid halides include terephthalyl dichlo-
ride, adipyl di~hloride, 1,3,5-benzenetricarboxylic acid
trichloride, oxalyl dibromide, 1,4-benzenedisulfonyl dichlo-
ride and 4,4'-biphenyldisulfonyl dichloride~ Mixtures of
these compounds may also be used. The preferred first wall-
forming materials are NIAX SF-50, ~esmodur N-100 and tereph-
thalyl dichloride.
The second wall-forming material can ~e selected
from the group consisting of polyols, polythiols, polyamines,
acid anhydrides, and polycarboxylic acids and mixtures
thereof. The polyols include for example, glycerin, resor-
cinol, 1,3-naphthalenediol, bisphenol A/1,3-propylene blycol,
1,5-pentanediol and the like. Examples of polythiols are
thioglycol and thioglycol condensates. Polyamines include,
for example, p-phenylenediamine, diethylene triamine,
* Trade Mark
N,N,N',N',-tetrakis-[2-hydroxypropyl) ethylene diamine
(Quadrol*-Wyandotte Chemic~l Corp., Wyandotte, Michigan)
and phthalamide and the like. Examples of acid anhydrides
includ~ maleic anhydride and succinic anhydride. Examples
of polycarboxylic acids are malonic acid, succinic acid
and terephthalic acid. The preferred second wall-forming
materials are Quadrol and diethylene triamine.
A photoinitiator is added to the coating compo-
sition to permit curing by ultraviolet radiation. A wide
variety of photoinitiators are available which serve well
in the system described in this invention. The preferr~d
photoinitiators are the benzoin alkyl ethers, such as
Vicure 30*, benzoin methyl ether, ~, a azobisisobutyroni-
trile, ar a-diethoxyacetophene and ~inc carbonate. Other
photoinitiators which can be used are benzophenone, 4,4'-
bis-(dimethylamino~benzophenone, ferrocene, xanthone, thi-
oxanthane, decabromodiphenyl oxide, pentabromomonochloro-
cyclohexane, pentachlorobenzene, benzoin ethyl ether,
2-ethyl anthraquinone, l-~chloroethyl~-naphthalene, desyl
chloride, chlorendic anhydride, naphthalene sulfonyl
chloride and 2-bromoethyl ethyl ether. The amount of
photoinitiator added can be ~rom about 0.2% to about 10
by weight of the coating composition, with a preferred
range from about 1% to about 4~ by weight.
Photoinitiation synergists can be added, if desi-
red, to the ultraviolet curable coating compositions. Photo-
initiation synergists serve to enhance the initiation
efficiency of the photoinitiators. The preferred synergists
are the chain transfer agents, such as the tertiary alcohol-
amines and substituted morpholines, triethanolamine, N-
methyldiethanolamine, N,N-dimethylethanolamine and N-
methylmorpholine. The amount of photoinitiation synergist
added can be from about 0.2% to about 10~ by weight of the
* Trade Mark
-12-
2~8
coating composition with a preferred range of from abou~ 3
to about 4% by weight.
In the preparation of the dispersion of microcap-
sules of this invention, a hydrophobic emulsion component
is prepared by dissolvin~ the first wall-forming material
in an hydrophobic liquid, as for example, an oil. If the
microcapsules are to be used in preparing carbonless copy
papers, a chromogenic material i5 dissolved in a carrier
oil.
The hydrophilic emulsion component is prepared
by dissolvin~ or dispersing an emulsifier and at least one
radiation curable polar compound in water. Any of the
known emulsifiers can be used including polyvinyl alcohol,
carboxymethyl cellulose, hydroxypropyl cellulose and Triton
N-lOl* (Rohm and Haas, Philadelphia, Pa.)O The water from
the radiation curable hydrophilic liquid increases the
polarity of the hydrophilic emulsion component to a point
where the two phases, hydrophobic and hydrophilic are essen-
tially insoluble in each other, thus permitting formation
2~ of an emulsion. At this pointr the second wall-forming
material sol~ble in the hydrophilic emulsion component can
also be dissolved in the hydrophilic emulsion component.
Alternatively, the second wall-forming material can be added
to the emulsion formed during the emulsification step. To
facilitate mixing the second wall-~orming material may be
dissolved in additional radiation curable hydrophilic liquid
prior to addition to the emulsion.
Alternatively, the second wall-forming material
may be added to the h~drophobic emulsion component. In
this case, the second wall-forming material is soluble in
the hydrophobic emulsion component. Some second wall-
~orming materials, ~or example, diethylene triamine, are
soluble in both the hydrophobic and hydrophilic emulsion
* Trade Mark
-!, . - 13-
_ ..
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components. These materials can be added to the hydrophobic
and/or hydrophilic emulsion components or to the emulsion
formed by the emulsification step.
Preparation of each of these components is easily
accomplished by stirring together at room temperature the
materials of each component. The Brookfield viscosity of
the hydrophilic emu]sion component can be from about 0.5
cps. to about 1,000 cps. The preferred viscosity is about
1 cps. to about 500 cps. a~d the most preferred viscosity
is from about 1 cps. to about 50 cops.
The hydrophobic and hydrophilic emulsion compo-
nents prepared as above are mixed together with high agita-
tion to form an emulsion containing droplets of the
hydrophobic emulsion component dispersed in the continuous
hydrophilic emulsion component.
The term "soluble" as used herein is intended to
describe wall-forming materials which are only partially
soluble in and give hazy solutions in the radiation curable
hydrophilic liquid as well as those which are completely
soluble in the radiation curable hydrophilic liquid.
-13a-
After emulsification, the emulsion is stirred for a period of a~out 3
hours to about 16 hours at a temperature of about 0 C to about 70 & , pre-
ferably ro~m temperature to about 40& , to allow the firs-t and secorld wall-
fonming materials to react and form a dis~ersion of microcapsules having
capsule walls which are substantially impermeable to both the hydrophilic and
hydrophobic enLlsion components used to form the microcapsules. The
microcapsules should be fr~m about 0.1 micron to about 50 microns in diameter.
A preferred range is from about 5 to 15 microns.
After formation of the microcapsules is complete, the photoionitiator
is added. m e microcapsular coating compositions prepared according to this
invention can contain from about 20~ to about 60%, by weight, wa-ter. The
preferred range is from akout 30% to about 50% water. The coating co~lposition
of this inv~tion can be applied to a substrate, such as paper or a plastic
filn ~y any of the ccmmon paper coating processes such as roll, air knife, or
blade coating, or by any of the ccmmon printing processes, such as offset,
gravure, or flexographic printing. The rheological properties, particularly,
the viscosity of the coating compositions~ can be adjusted for each type of
application by proper selection of the type, molecular wei~ht and relative
amounts of the liquid radiation curable compounds and the amount of water present.
ThPse coating ccmpositions can be set to a solid film by a cc~bination o
ultraviolet radiation and infra-red radiation. A typical ultraviolet source
suitable for this t~pe of curing process is a Hanovia 200 watt medium pressure
mercury lamp which emits both ultraviolet and infra-red radiation. Polymeri-
zation efficiencies of the coating composition æ e dependent on such para~eters
as the nature of the radiation curable polar comFounds, atm~sphere in contact
with the coating, quantum efficiency of the radiation absorbed, thickness of
coating and inhibitory effects of the various materials in the compositiQn.
The ~ater present on the coating composition is e~aporated by the ener~y
of the in~ra-red radiation.
~9z~
The coating weight of the solid film containing
the microcapsules can be from about 0.2 pounds to about 12
pounds per 3300 square feet. The preferred coating weight
range is from about 4 to about 7 pounds per 3300 square
feet.
The following examples further illustrate but do
not limit the invention:
Example 1
An aqueous phase (hydrophilic emulsion component)
was prepared as follows:
In a 250 ml. beaker with magnetic stirring bar on
a magnetic stirrlng hot plate, 40 grams of distilled water,
60 grams of a radiation curable compound, 2-hydroxyethyl
acrylate, 0.5 gram of carboxymethyl cellulose (grade 7L2,
Hercules, Inc., Wilmington, Delaware) and 0.5 gram of hydroxy-
propyl cellulose (Klucel L*, Hercules, Inc.) were mixed to-
gether and then heated to 60C until the solid ingredients
were dissolved. After cooling the mixture to room tempera-
ture, 0.1 gram of Turkey Red Oil (Sulfonated castor oil)
and 0.5 gram of trie~hylene tetramine were stirred in.
An oil phase (hydrophobic emulsion component) was
prepared as follows:
In an 100 ml. beaker with magnetic stirring bar
on a magnetic stirring hot plate, 24 grams of monoisopropyl-
biphenyl, 0.83 gram of 3-(N,N-diethylamino-7-(N,N-dibenzyl-
amino)fluoran, and 0.08 gram of 2,3-(1'-phenyl-3'-methyl)-
7-(N,N-diethylamino)-4-spirophthalidochromene were heated
with stirring at 90C for one hour to dissolve the above
color precursors. To this solution at room temperature, 3
grams of an aliphatic polyisocyanate (desmodure N-100), 3
grams of an aromatic polyisocyanate (NIAX SF-50) and 0.9
gram of a polyol (Quadrol) were added with stirring until
homogeneous.
* Trade Mark
~-~ -15-
,
,
2~
The oil phase in the 100 ml. beaker was added
slowly over a one minute period to the first solution in
a Waring Blender on low speed, and stirred for five
minutes more. A mint green colored mixture resulted in
which capsules 1 to 4 microns in diameter were observed
through a 450X microscope. The mixture was placed in a
60C hot water bath for 30 minutes. An off-white disper-
-15a-
.,~ . .
~, ~
i:
resulted, with no apparent chanye in capsule size. 1.5 grams of azobisiso~u-
tyronitrile photoinitiator was added, a drawdown was made on 13.5 lb. per 1300
square feet paper rawstock wi-th a No. 16 Mayer rod and exposed to a 200 ~att
mercury ultraviolet lamp at a distance of 4 inches for one minute. Ihe coating
was smooth and tack-free. When pressure imaged against a kaolin/phenolic resin
coated CF sheet, a clear, green image was formed on the CF sheet.
Example 2
The exa~lple above was repeated except that 0.5 gram of polyvinyl alcohol
(grade 50-05, E. I. duPont de Nemours & Co., Inc., Wilmington, Del.) was used
in place of hydroxypropyl cellulose. Capsules before heat c~ring were 1 to ~
microns as determined by microscopic e~amination of the dispersion. The image
formed was clear but not as intense as in Example 1.
Example 3
An aqueous phase was produced by s-tirring together 90 grams of a radia-
tion curable ccmpound, N-~ethylol acrylamide (60% solution in water, from
Proctor Chemical Company, Salisbury, N.C. 28144), 0.5 gram of a dispersing agent(Triton N-101 - Rohm and Haas Company, Philadelphia, Pennsylvania), 0.8 gram of
sodium carbonate (anhydrous) and 9.3 grams of diethylene triamine,
An oil solution was prepared by dissolving the following color precur-
sors into 19 grams of MIPB (monoisopropylbiphenyl) with heating to 85C: 0.40
gram of crystal violet lactone, 0.10 gram of 3,3-bis(l'-ethyl-2'-methylindol-3-
yl) phthalide, 0.17 gram of 2,3-(1'-phenyl-3'-methyl)-7-~N,N-diethylamino)-4-
spirophthalidochromene, and 0.05 gram of 3-N,N~diethylamino-7-~N,N-dikenzylamino)
fluoran. When the solution was cooled and filtered, 3 grams of terephthaloyl
chloride were dissolved. The oil solution was added to the aq~leous phase in a
Wari~g Blender operating a high speed over a 30 second period and was stirred
for 5 minutes more. Microscopic examination of the fluid, gray muxture skK~
capsules of 2 to 10 micron size. Few agglcmerates were present. A 0.1 gram of
benzoin me~hyl ether phoboinitiator was stirred in. m e mixture was coated on
13 Ib./1300 square feet form bond using a No. 16 Mayer rcd and e~posed bD an
ultraviolet lamp as in Example 1. When pressure ima~ed against kaolin/phenolic
coated CF paper with a ballpoint pen, a purple image was formed.
Example 4
~n aqueous phase was produced by stirring together 90 grams of a radia-
tion curable compound, N-methylol acrylamiae (60~ solution in water, from
Proctor Chemical Ccmpany, Salisbury, N.C. 28144), 1.0 gram of a dispersing
agent ~Triton N-101 - Rohm and Haas Company, Philadelphia, Pennsylvania), and
1.59 gram of sodium carbonate (anhydrous).
An oil solution contail~ing color precursors was prepared as in EXa~ple
3 and 3 grams of terephthaloyl chloride were dissolved therein. The oil solution
was added to the aqueous phase in a Waring Blender operating at high speed over
a 30 second period and was stirred for 3 minutes more~ To the Waring Blender
mixture, 6.19 grams of diethylene triamine was added over a 15 seoond period
and the speed was reduced to low speed for 5 minutes re. Microsoopic examina-
tion of the fluid, light pink mixture showed capsules of approximately 2 to 10micron size. Few agglcmerates were present. 0.1 gram of kenzoin methyl ether
photoinitiator was stirred in. The ~ux~ure was coated on 13 Ib./1300 square
feet form bond using a No. 16 Mayer rod and exposed to an ultraviolet lamp as
in Example 1. When pressure imaged against kaolin/phenolic coa-ted CF paper with
a ballpoint pen, a purple image was formed.
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