CA1123997A

CA1123997A - Lithographic ink vehicle containing addition polymers and aliphatic hydrocarbon solvent

Info

Publication number: CA1123997A
Application number: CA295,526A
Authority: CA
Inventors: Graham Swift; Harry J. Cenci; Raymond F. Jenkins
Original assignee: Rohm and Haas Co
Current assignee: Rohm and Haas Co
Priority date: 1977-02-07
Filing date: 1978-01-24
Publication date: 1982-05-18
Also published as: AU517975B2; FR2401209A1; IT7867238A0; GB1563670A; FR2401209B1; DE2803943A1; NO780399L; DK54578A; CH627776A5; GB1563669A; JPS5398385A; SE7801356L; FR2396032A1; AU3299778A; BE863624A; NL7801394A

Abstract

ABSTRACT OF THE DISCLOSURE

The specification discloses a lithographic ink vehicle containing an addition homo- or co-polymer of ethylenically unsaturated monomers having a critical calculated second order transition temperature (Tg), and a critical molecular weight, utilizing as the essential solvents in the ink a predomi-nantly aliphatic hydrocarbon having akauri-butanol value of between about 18 and 31, preferably between about 21 and 28, in which the polymer must be soluble. Among the preferred monomers or comonomers are isobornyl methacry-late and isobutyl methacrylate. Other ethylenically unsaturated monomers may be included, particularly functional monomers in small amounts having acid or amine groups.

Description

3~t9~

Background of the Invention Copolymers containing isobornyl methacrylate, one of the preferred monomers of the invention, are shcwn in various prior disclosures.
me following three patents, for example are assigned to the assignee of the present application. Martorano, U.S. Patent No. 3,940,353, shows a copolymer containing 40 to 60~ by weight of isob~rnyl methacrylate and having an average ~Dlecular weight of between 1,000 and 8,500. They are utilized as pigment dispersants and laoquers, and in blends with materials such as alkyds, vinyl resins and cellulose ester resins. The materials shown in the examples of the patent are insoluble in aliphatic hydrocarbons, althou~h if styrene is substituted for methyl methacrylate, they possibly could be soluble in certain cases. Hurwitiz et al, U.S. Patent No. 3,681,298, relates to the same ~opolymer and claims the copolymer per se. Hurwitz et al disclose pigments such as carbon black and phthalocyanine blue. Cenci et al U.S.
Patent No, 3,485,775, relates to an isobornyl methacrylate copolymer as a m~difier for polyvinyl chloride, the acrylic polymer having a number average molecular weight of between 10,000 and 1,500,000. Ihe polymer contams 25 to 75 parts of isobornyl methacrylate with 70 to 25 parts by weight of methyl methacrylate, optionally with up to 10% of other unsaturated monomers based on the combined wei~ht of the first two. me polymer is dry blended ; with polyvinyl chloride and molded or ex*ruded.
Acrylic copolymers for inks are also kncwn as shown for example in U.S~ Patent Nos. 3,271,347 (~ronoff et a]) and 3,764,587 (Zunker). The inherent viscosity of the polymer of the latter patent, a measure of molecular weight, is between 0.2 and 0.35 measured at 25~C. using 25 milligrams of polymer in 5 cc. of chloroform, which suggest a M~ of 100,000 or greater. m e mDnomers in the polymer are such as would yield a very rukbery, soft, product~
having a vely low calculated T as defined herein. The Aronoff et al polymer in one embodL~ent is primarily of vinylidene chloride, with acrylic and methacrylic acid or itaconic acid, with the optional inclusion of other mono~ers. The vinylidene chloride copolymers have molecular weights in the

- 2 -range of 3,000 ko 5,000. Aronoff et al also mention allacrylic copolymers, the invention being in the inclusion of polyoxyethylene ethers. No met~hod of preparing the acrylic polymer is disclosed nor are molecular weights. The specific acrylics disclosed have extremely low calculated T Is. Aronoff et al disclose solvents including aliphatic hydrocar~ons, aromatic hydrocarbons, ketones, alcohols, etc.
Summary of the Invention The present invention is in the discovery that the utilization of an addition polymer containing polymerized ethylenically unsaturated monQmers, particularly those prepared from a narm w class of certain monomers, including homopolymers but most preferably interpolymers from certain comonomers in critical ratios, along with a particular class of aliphatic hydrocarbons solvents, as an essential component in a printing ink, gives a quick-set ink or a heat-set ink with excellent characteristics, without the need to use additives to provide hardness, such as nitrocellulose, oellulose aoetate butyrate, shellac, polyamides, aIkyds, and the like.
e present invention, in one aspect, resides in an addition co-polymer, soluble in a hydrocarbon solvent having a kauri-butanol number of between 18 and 31, said solvent comprising at least about 70~ of saturated hydrocarbons, said copolym~r being composed of from about 1% to about 40~ isobornyl methacrylate mer units, the ren~inder of said copolymer being polymerized ethylenically unsaturated monomers which do not detract from said solubility, bhe MW of the polymer being from about 1,000 to about 15,000, and the calculated Tg Of the polymer being from about 40 C.
to 200C.
In another aspect, the invention resides in a printing ink containing the above-described addition copolymer dissolved in a hydrocarbon solvent comprising at least 70~ of aliphatic hydrocarbons and having a kauri-butanol number of bfftween 18 and 31.
30. An improvement quality of such addition poly~er is the molecular ~,3~

weight thereof. The molec~ar weight must be between 1,000 to 15,000, preferably 12,000, on a weight average basis, (Mw), and between 1,000 and 7,500, preferably between 1,500 and 5,500, on a number a~erage molecular weight basis ~Mh). Molecular weight is critieal since the polymer viscosity at a constant solids content is proportional to moleeular weight, partieularly Mw Another important property of the polymer is the Tg thereof, and consequently the selection of m~nomers and proportions thereof depends upon their influenee on the T . "T " is a oonventional criterion of polymer hardness and is deseribed by Flory, "Principles of Polymer Chemistry," pp. 56 and 57 (1953)~ Cornell University Press. See also "Polymer Handbook", Brandrup and Immergut, See. III, pp. 61-63, Interseience (1966). While aetual measurement of the T ean be used, it is difficult to obtain an aceurate value - on low moleeular weight polymexs, and it may be ealeulated as described by Fox, Bull. Am. Physics Soc. 1, 3, p. 123 (1956), or by the use of "Rohm and Haas Acrylie Glass Temperature Analyzer" Publieation No. CM~24 L/cb, Rohm and Haas Company, Philadelphia, Pa., 19105. While the aetual Tg'S of the invention are lower than the ealculated T because of low molecular weights, the calculated T values, which are essentially the same as the measured Tgls of high moleeular weight (~100,000, Mn) polymers, are relevant indicia of the relative Tgls of different polymers. Examples of the Tg of high moleeular weight (~100,000) homopolymers, and the inherent Tg values thereof whieh permit such caleulations, are as follcws:
Homopolymer of Tg 2-ethylhexyl acrylate-90 C.
n- deeyl methacrylate -60 C.
n-butyl acrylate -56 C.
n-tetradeeyl. methacrylate -9 C.
n-tetradeeyl aerylate 20 C.
t-butyl acrylate 43 C.
methyl methacrylate 105 C~

styrene 100 C.
acrylic acid .106 C.
isobornyl ~ethaerylate 180 C.

~3~

Another critical requirement of the invention is that there be a balan oe between the second order transition temperature (Tg), and molecular weight. The calculated Tg of the poly~ers according to the invention, havLng ~olecular weights within the ranges specified above, have a value falling between about 40 C. and about 200 C. preferably between about 50Q C. and 120 C. me approximate calculated Tg of a high molecular weight homopolymer of isobornyl methacrylate is about 180 C. However, as specified, the actual molecular weight is much lcwer and thus th~ actual Tg maiy be lower than the "calculated" value. The calculated value is given as a significant index of the lcwer, but relative actual Tgl of the low molecular weight polyner.
In general, oopolymers are preferred. Thus, in addition to ~onomers such as isobornyl methacrylate, other mononers may be used in suitable mp nts, particularIy those which give polymers having high calculated TglS, i.e., if prepared as high molecuIar weight polymers, 5uch polymers would have high Tg values matching thie calculated value, provided of course that the low .:
mDlecular weight polymers of the inventio~ are soluble in the specified low kauri-butanol (KB) value sol~ nts. ~xamples of other useful monomsrs are isobutyl methacry1ate ~Tg 49 C.) tert-}utylaminoe*hyl acrylate ~Tg 30 C.), methacrylic acid (Tg>100 C.), dimethylam moethyl methacrylate ~Tg 18 C.), dimethylamlnoethyl acrylate, acrylic acid (Tg 105 C.) maleic anhydride, itaconic acid,oxazolidinyl-e~hyl methacrylate, and strene (Tg 100 C). Others include dicyclopentenyl methacrylate and acrylate, dicyclopenteneyl-etho~y methacrylate, and~acrylate, butyl methacrylate (Tg 20 C.) dicyclopentenyl-neopentoxy methacrylate and acrylate, isobornyl acrylate, and vinyl aromatics :
such as ~-c~hloro styrene, ~-methyl styrene, _-butyl styrene, and vinyltoluene. ~ethyl methacrylate (Tg 105 C.) can be used, but only in limlted am~unts, because o~ limited solubility. As noted above, such limited amounts can be readily as oertained.
;- Isobornyl methacrylate and/or isobutyl methacrylate are preferred components of the pol~mer. When isoborny] methacrylate is utilized in a ~3963~

copolymer, it is used in an a~ount of about 1 to 40~, rnore preferably from about 5 to 35%. Where isobornyl methacrylate is omitted, and isobutyl methacrylate is a component of the poly~er, usually it is present in an amDunt of between about 50% and 100% by weight, the remainder preferably being one or more of the other monomers mentioned heretofore, and more preferably one or mDre of the vmyl aromatics, tert-butylaminoethyl methacrylate, dimethyl-aminoethyl methacrylate, maleic anhydride, acrylic acid, methacrylic acid, itaconic acid, or oxazolidinylethyl methacrylate. The nitrogen-containing and carboxylic acid containing monomers are used in very small am~unts, if at all, and preferably in an am~unt of from about 0% to about 5%, preferably at least 0.5% by weight of the total monomers. For example, a copolymer of vinyl toluene/isobutyl methacrylate in the ratio of 50/50, or a polymer of styrene/isobutyl methacrylate in the ratio of 30/70 are useful; with or without the nitrogen containing or carboxylic acid containing monomers in small amounts. The preferred copolymers contain both isobornyl methacrylate and isobutyl methacrylate. Particularly preferred are copolymers of interpolymers contaim ng from 35% to 75% isobutyl methacrylate and from 15%
to 40%, more preferably below 35%, isobornyl methacrylate, any remainder be mg other ethylenically unsaturated monomers such as styrene, methacrylic acid, dimethylaminoethyl methacrylate and the like.
me polymers are preferably prepared by high temperature solution poly~erization, which is kncwn to give low n~lecular weight polymers, although low molecular weights can be obtained by other methods such as ~he inclusion of a molecular weight regulator such as an aliphatic mercaptan, for example, n-dodecyl mercaptan. In a preferred polymerization procedure, the low KB
(kauri-butano]) predominantly aliphatic hydrocarbon solvent is included as at least one of the solvents utilized in the polymerization. E'or example the conbination of xylenes, or other suitable hydrocarbon, and a hydrocarbon solvent having a KB value of about 25 may be used with a suitable polymerization catalyst or initiator, and the residual monomexs and xylene or other hydrocarbon stripped off by distillation after completion of the polymerization.

.~

~3~7 Another means of o~taining low mol~cular weight polymers in~Dlves the utilization of a particular anionically initiated polymerization prooedure, USLng methanol and e.g., sodium methoxide, Ln palticular using acrylic ester and methacrylic ester mDnomers. These polymers have an extremely ~arrcw distribution of molecular weights and are prepar~d by a unique procedNre described in Canada Patent N~. 959,999, granted Dece~ker 24, 1974; U.S. Patent No. 4,056,559~ granted ~ er 1, 1977; and Canadian Patent No. 1,013,096, granted June 28, 1977, all three patents being in the names of Sheldon N. Lewis and Richard A. ~aggard, and æsigned to Rohm and Haas Cbmpany. Ihe reader is referred to said patents ~or a description of ~ethods of cbtaining l~w molecular weight or oligomeric polymers of aLkyl acxylates and alkyl methacrylates as well as ~or a teaching o methods of transesterifying the resulting polymers ~o cb~ain for example oxazolidine groups, oxazolidinyl acrylates and methacrylates, isobornyl acrylates and methacrylates and the like. Also well adapted to transesterification is low molPcular weight polymeth~l methacrylate, utilizmg an aloohol such as isobornyl alcohol such as isobornyl aloohol and a catalyst such as sodium methoxide, and in which the displaced methanol is distilled off, resulting in polyisobornyl methacrylate.
The liguid solvents in the ink are oonventional solvents in the printing ink industry, but they find unique applicability when c3mbLned with the resins of thR in~ntion. m e solvents have a KB value of ketween 18 and 31, pre~erably between 21 and 28. Typical pr~ducts have a ninImum of about 70~ paraffms, i.e., oonsisting essentially of saturated hydrocarbans with no more than about 25~ aromatics, on a weight basis. lhey may contain small percentages of aliFhatic olefins, less than lO~, and preferably less than about 5%. The average molecular weight is between about 160 and 240. They have an m itial boiling point o bebween about 400~ and about 600F., with a final boiling point of between about 475 and 700F. Ihe preferr~d initial boiling point is between about 400 and 450F. with a final boiling point of bebween 475 and 600F. The anil ~e poLnt is between about 150 and 200. Suit-able products are obtained from M~gie Bros. Oil Cbmpany, 9101 Fullerton Avenue, Franklin Park, Illin~is 60131. Suitable products are sold as "M~gie Oil" 400, * **
~5, ~ 440, "DeD" , ~40, 470, 4600, 500, "Deo"

*Trademark *~Tra~emark ~23~7 520, 535, 5300, 590, 625, and "Deo"** 620. Gther boiling ranges are usable provided the KB value is as specified~
Typical pigments include carbon black, phthalocyanine blue, titanium dioxide, lithol rubin reds, ultramarine blue, hansa yellow, and the like. A suitable pigment:binder ratio is between .01:1 and 2:1, weight basis. In so~e cases, no pi~ment is necessc~ry.
Determ mation of the properties of the polymers are by conventional methods. The kauri-butc~nol value is the number of milliliters of the hydrocarbon or other liquid required to case cloudiness when added to 20 gms of a solution of kauri gum and butyl alcohol, in which there is ! 100 gms of kauri gum and 500 gms of butyl alcohol. This is basically ASTM
method D-1133, Volume 20.
Molecular weight is determined by gel permeation chromatography, utilizing polymethylmethacrylate for calibration.
Second order transition temperature or glass transition tem~erature (Tg) is the teoperature at which the polymer changes from a glassy state to a rubbery state, calculated as noted abov~.
`~ Ihe i~c has exoellent scruff and abrasion resistance, blocking -I resistance and heat-s~ear resistance even without the polymeric additives noted above, such as the oe llulose esters. In addition to good quick fast-set and heat-set, and other superior qualities, the products have excellent gloss and e~cellent adhesion to porous and nonporous substrates. In addition, the resins of the invention are useful for pigment flushing, with flushed pigments - can be let down with more of the resin of the invention and ~ormulated into lithographic quick-set and heat-set inks.
Specific EhtDdim nts In the following examples, the monomer abbreviations have the follcwing meanings:
iBMA i~obutyl methacrylat~
iBo~ isobornyl methacrylate ** Trademark !

- ~L239~

ST styrene M~A methkacrylic acid VT ~inyltoluene MMA methyl methacrylate t-~AEMA tertiary butylaminoethyl methacrylate Plso in the examples, the "Magie Oill'* 535 and 470 have the following properties:

API gravity 43.7 36.9 Flash F. 230 285 KB ~umber 26.9 25.4 Aniline Point F. 170 173 % Aromatics (wt.~ 10 22 % Olefins (wt.) 5 2 % Paraffins (wt.) 85 76 Average Arithmetical Mole~ular Weight 205 235 ~egarding typical distillations, "Magie Oil"* 470 has an initial boil mg point of 470F. and a final boiling point of 515F., while l'Magie Oil"* has an initial boiling point of 524F. and end point of 595F.
Unless otherwise specified herein, all parts and ratios are by weight. Iemperatures are either C. or F., as specified.
EXAMPLE I
Preparation of a Polymer of the Composition iEMA~iBQM~M~A//57/40/3WT.%
_.
1. Equip~ent 5 liter, 4 neck round bottom flask equipped with stirrer, condenser, thermometer and addition funnel with an N2 inlet. The flask is heated with an oil bath.
2. Charges A. Xylene 239 B. "Magie" 535 oil 200 _ g _ * Trademark ~3~

C. Tertiary butyl perbenzoate (85%) 51.6 D. "Magie" 535 oil 145 E. Isobutyl m~thacrylate 1000 F. Isobornyl methacrylate 701 G. Methacrylic acid S3 H. Tertiary butyl perbenzoate (85%) 25.8 I. "Magie" 535 oil 50 J. "Magie" 535 oil 744

3. Procedure 1. Prepare initiator feed ~C & D) and mono~er feed (E, F & G)o 2. Charge A & B to the flask and heat to 150 C. Maintain an N2 atmosphere throughout the reaction.
3. When heat is at 150C. begin to add the monomer and initiabor feeds. Charge these feeds linearly over , ~` 5 hours.

4. When feeds are complete, cool the system to 130 C. over 0.5 hours.
` 5. ~t 130 C. chase with (H & I) over 0.5 hr. Hold at 130 C
for 1 hour.
6. Gradually apply vacuum and increase t~nperature to a maximum of 150 C. and 25 mm. vacuum to rem~ve xylenes and unreacted iBMA.
7. When analytical results indlcate that ~esidual monomers are within specifications, oool to 100 C. and dilute to 60~ solids with J.
Characteriza-tion .
Pol~mer Solids 60 -~ 2 wt. %
Viscosity ca. 200,000 cps.~ 25 C.
Cblor Clear amber solution, free frcm particulate matter Calculated 1~ = 93 C.

~1~3~d:3~7 Mn = ~ 4300 MW = ~ 9500 EXAMPLES II-V
By a s~ilar procedure to that described, the p~lymer ccmpositions shown below and with the given properties are obtained as solutions in either Magie Oil 535 or 470 as shcwn.
Composition (wt.%)SolventVlscosity/Solids 2. i~MA/iBCMA/ST/M~AMagie 535127,000 / 60 Calculated Tg = 89 C.
Mn = ~ 4770 ~ = ~ 11,000 3. iBM~iBCMA~VT/MA~Magie 535 128,000 / 60 Calculated Tg = 81 C.
~ Mn = ~ 2600 -~ M~ = ~ 8300 4. iBM~/iBaM~/MM~/MAAMagie 535178,000 / 60%

Calculated Tg = 85 C.
. Mn = ~ ~100 Mw = ~ 10,500

5. iBMA/iBCVP/MY~/t-B~EMA Magie 535 170,000 / 60 Calculated Tg = 82 C.
~n = ~,3100 Mw = ~ 8700 EX~MPLE VI
QUICK-SET INKS
Blue_Ink Based on Polymers 6 (or ~) iBM~/iBQM~M~A

Calculated ~g = 79 C. ~w = 7,000-8,500; Mn = 2,000-2,500 ~L23~

iEM~/iBCMP4t-~AEM~/M~A

Calculated Tg = 76 C.
k~ ^ s,noo Mn - 3,500 These polymers are prepared similarly to the foregoing.
Formulation:
Phthalo Blue 14.7 Polymer 6 (60% Solids in "Magie Oil" 535~ 76.7 "Magie Oil" 535 8.6 Total 100.0 Constant:
Total Solids % 60.7 :~ Pigment/Binder Ratio 24/76 : Red Ink Based on Polymer 6 ox 7 -- . .
~- FormLlation:
Lithol Rubine (Red pigment) 14.7 Polymer 6 (60% Solids in "Magie Oil" 535) 76.7 "Magie Oil" 535 8.6 - Total 100.0 Constant:
lbtal Solids 60.7 Pigment/Binder Ratio 24/76 Blue Ink Based on P lu ~ uick-Set ~arnish Forn~llation:
Phthalo Blue 16.7 Polymer 6 (60~ Solids in Magie 535) 20.1 "Magie Oil" 535 3.2 "Uroset"*(Urethane-modified alkyd to give fast drying)1 50 3 l~wter Chem~cal ~
* Trademark - 12 -"Plvco 19641"**(W~xy slip aid) 7.4 Cobalt Napthenate (6% metal) 1.7 Manganese Naphthenate (6% metal) 0.6 Total 100.0 Constant:
Total Solids 66.1 Pigment/Binder Ratio 25/75 EXAMPLE VII
HEAT-SET INKS
.
Black Ink Based on Polymer 6 Formulatlon:
Carbon Black 10.0 Polymer 6 (60% Solids in "Magie Oil" 470) 84.4 "Magie Oil" 470 2.7 "~crofive VI-FS "*** (Waxy slip aid) 2.9 Ibtal 100.0 Constant:
Tbtal Solids 63.6~
Pigment/Binder Ratio 16/84 ~ The follcwing is a sample calculation of the glass transition tem~erature ; of polymer No. 6, iEM~/iBCM~/M~A 69/29/2, using the Fox equation.
The Fox equation is:
1 wt. fraction Mbncmer #l T Copol. T Homcpolymer #l wt. fraction Monomer #2 Tg Hom~pol~ner # 2 etc.
The temperatures in the equation are degrees Kelvin. Thus for copolymer #6, l .69 .29 .02 Tg ~ 501 T = 352K. = 79C.
g .
Lawter Chemical Co. ** Trad OE k Dura Ccmmcdities Cbrp. *** Trademark - .

Claims

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. An addition copolymer, soluble in a hydrocarbon solvent having a kauri-butanol number of between 18 and 31, said solvent comprising at least about 70% of saturated hydrocarbons, said copolymer being composed of from about 1% to about 40% isobornyl methacrylate mer units, the remainder of said copolymer being polymerized ethylenically unsaturated monomers which do not detract from said solubility, the ?w of the polymer being from about 1,000 to about 15,000, and the calculated Tg of the polymer being from about 40° C.
to 200° C.

2. The polymer of claim 1 in which the polymerized isobornyl methacrylate is present in an amount of from 5% to 35%, the ?w of the copolymer is between about 4,000, and about 12,000 said Tg is between about 50° and about 120° C., and said kauri-butanol value is from about 21 to about 28.

3. The polymer of claim 1 in which polymerized isobutyl methacrylate is present in said copolymer in an amount of between 35% and 75%, and the isobornyl methacrylate is present in an amount between about 15% and about 35%.

4. The polymer of claim 3 in which one or more of the additional monomers, dicyclopentenyl methacrylate and acrylate, dicyclopentenylethoxy methacrylate and acrylate, dicyclopentenylneopentoxy methacrylate and acrylate, isorbornyl acrylate, a vinyl aromatic monomer, a carboxylic acid monomer or a nitrogen-containing monomer is included.

5. The polymer of claim 3 containing about 0.5% to 5% of at least one of unsaturated amino monomer units and unsaturated acid monomer units.

6. The polymer of claim 5 which consists essentially of isobutyl methacrylate, isobornyl methacrylate, and one or more of methacrylic acid, acrylic acid, itaconic acid, tert-butylaminoethyl methacrylate, dimethylaminoethyl methacrylate, and 2-(3-oxazolidinyl)ethyl methacrylate.

7. A printing ink containing the polymer of claim 2 dissolved in said solvent.

8. A printing ink containing as a binder the polymer of claim 3 dissolved in said solvent.

9. A printing ink containing as a binder the composition of claim 4 dissolved in said solvent.

10. A printing ink containing as a binder the polymer of claim 5 dissolved in said solvent.

11. A printing ink containing as a binder the polymer of claim 6 dissolved in said solvent.

12. A method of printing comprising applying the ink of claim 8 to a substrate and setting said ink.

13. A method of printing comprising applying the ink of claim 8 to to a substrate and setting said ink.

14. A method of printing comprising applying the ink of claim 10 to a substrate and setting said ink.

15. A printing ink containing a polymer and a hydrocarbon solvent comprising at least 70% of aliphatic hydrocarbons, said solvent having a kauri-butanol number of between 18 and 31, said polymer being an addition copolymer composed from about 1% to about 40% isobornyl methacrylate mer units and the remainder of said copolymer being polymerized ethylenically unsaturated monomers which do not detract from the copolymer's solubility in said hydrocarbon solvent, the ?w of the polymer being from 1,000 to 15,000, and the calculated Tg of the polymer being from 40° C. to 200° C.

16. The ink of claim 15 containing a pigment, in which the ?w of the copolymer is at least 4,000, said T is between 50° and 120° C., the kauri-butanol value of said solvent is from 21 to 28, and the pigment:binder ratio is between about 0.01:1 and 2:1, weight basis.

17. A method of printing comprising applying the ink of claim 15 to a substrate and setting said ink.

18. The method of printing comprising applying the ink of claim 16 to a substrate and setting the ink.

19. The ink of claim 15 in which said monomers include at least one of isobutyl methacrylate, isobornyl acrylate, dicyclopentenyl methacrylate, dicyclopentenyl acrylate, dicyclopentenylethoxy methacrylate, dicyclopentenylethoxy acrylate, dicyclopentenylneopentoxy methacrylate, dicyclopentenylneopentoxy acrylate, and a vinyl aromatic monomer.

20. The ink of claim 19 in which the monomers include up to about 5 percent of at least one of an unsaturated amino monomer and an unsaturated acid monomer.