Importance of Monomer Interfacial Tension for UV Curable Litho Inks Performance.Editor's Note Editor's Note (foaled in 1993 in Kentucky) is an American thoroughbred Stallion racehorse. He was sired by 1992 U.S. Champion 2 YO Colt Forty Niner, who in turn was a son of Champion sire Mr. Prospector and out of the mare, Beware Of The Cat.
Trained by D. : "Importance of Monomer monomer (mŏn`əmər): see polymer.
Molecule of any of a class of mostly organic compounds that can react with other molecules of the same or other compounds to form very large molecules (polymers). Interfacial Tension Noun 1. interfacial tension - surface tension at the surface separating two non-miscible liquids
interfacial surface tension
surface tension - a phenomenon at the surface of a liquid caused by intermolecular forces for UV Curable cur·a·ble
Capable of being cured or healed. Litho Inks Performance" was presented during the 2002 RadTech Technical Conference in Indianapolis, IN. [C]2002, RadTech International North America North America, third largest continent (1990 est. pop. 365,000,000), c.9,400,000 sq mi (24,346,000 sq km), the northern of the two continents of the Western Hemisphere. , Inc. Reprinted with permission from the RADTECH 2002 Conference Proceedings.
For many years, the Years, The
the seven decades of Eleanor Pargiter’s life. [Br. Lit.: Benét, 1109]
See : Time goal of ink makers is to improve the runnability and lithographic lith·o·graph
A print produced by lithography.
tr.v. lith·o·graphed, lith·o·graph·ing, lith·o·graphs
To produce by lithography. behavior, dot gain, cure speed and odor for UV offset inks. Unfortunately, the formulation of UV curable printing inks depends on many variables, both in ink making and in lithography lithography (lĭthŏg`rəfē), type of planographic or surface printing. It is distinguished from letterpress (relief) printing and from intaglio printing (in which the design is cut or etched into the plate). process.
One of the key properties of a good lithographic ink is its ability to emulsify e·mul·si·fy
To make into an emulsion.
e·mulsi·fi·cation n. the fountain solution and its water pickup. The ink-water interaction, in our particular case, is determined by the hydrophilic hydrophilic /hy·dro·phil·ic/ (-fil´ik) readily absorbing moisture; hygroscopic; having strongly polar groups that readily interact with water.
adj. properties of the various raw materials used in the formulation, such as UV binders, pigments, photoinitiators and UV monomers.
The aim of this paper is to describe the lithographic behavior from different grades of GPTA (glycerol glycerol, glycerin, glycerine, or 1,2,3-propanetriol (prō`pāntrī'ŏl), CH2OHCHOHCH2OH, colorless, odorless, sweet-tasting, syrupy liquid. propoxylated triacrylate) at 19% in a magenta UV offset ink. The two GPTAs were tested with various interfacial tension properties which are more hydrophilic for one, and for the other one, more hydrophobic hydrophobic /hy·dro·pho·bic/ (-fo´bik)
1. pertaining to hydrophobia (rabies).
2. not readily absorbing water, or being adversely affected by water.
In the last 20 years, UV curing inks have been widely used in the field of lithographic ink. According to according to
1. As stated or indicated by; on the authority of: according to historians.
2. In keeping with: according to instructions.
3. some market surveys, [1,2] radiation curable inks are forecast to enjoy a 10 percent growth rate.
This growth is also due to a continuous improvement in printing technology. Recent developments in printing presses (sheetfed and web machines in terms of high speed production and inking/dampening units) and drier equipment (nitrogen blanketing and cold lamps) have led to a significant increase in the number of applications in the graphic arts graphic arts: see aquatint; drawing; drypoint; engraving; etching; illustration; linoleum block printing; lithography; mezzotint; niello; pastel; poster; silk-screen printing; silhouette; silverpoint; sketch; stencil; woodcut and wood engraving. industry, including boxes for cosmetics, food, tobacco, spirits, business forms, direct mail, lottery tickets and credit cards.
Formulation of UV curable printing inks depends on many variables. In this paper, we have tried to highlight the role of the physical behavior of the monomer in an ink recipe. We have fully characterized the monomers in term of interfacial tension in order to anticipate their behavior with water in a lithographic process.
Furthermore, inks have been formulated with these monomers and end-used properties have been compared.
Raw Material Characteristics
All the monomers used in the study are Cray (Cray, Inc., Seattle, WA, www.cray.com) A supercomputer manufacturer founded in 1972 as Cray Research, Inc., by Seymour Cray, a leading designer of large-scale computers at Control Data. In 1976, it shipped its first computer to Los Alamos National Laboratory. Valley products. The GPTA monomers have been synthesized syn·the·sized
1. Relating to or being an instrument whose sound is modified or augmented by a synthesizer.
2. Relating to or being compositions or a composition performed on synthesizers or synthesized instruments. in order to change their affinity with water.
UV ink formulation
The printing inks for the laboratory and press investigations have the following formulation (see Table 1).
The experiments are performed on a Kruss Drop Shape Analysis System DSA (1) (Directory Server Agent) An X.500 program that looks up the address of a recipient in a Directory Information Base (DIB), also known as white pages. It accepts requests from the Directory User Agent (DUA) counterpart in the workstation. 10 at T=23[degrees]C.
The interfacial tension is measured using the pending drop method.  A drop of liquid is formed at the tip of a syringe syringe /sy·ringe/ (si-rinj´) (sir´inj) an instrument for injecting liquids into or withdrawing them from any vessel or cavity. needle in a water medium. The drop shape and size depend on the interfacial tension between the liquid and the water medium.
Thus, from the profile of the drop, a software enables the calculation of the value of interfacial tension. It must be noted at this point that the same measurement can be done in air in replacement to water and thus the surface tension of the liquid is obtained.
* Viscosity is measured with a Laray viscometer viscometer
Instrument for measuring the viscosity (resistance to internal flow) of a fluid. In one type, the time taken for a given volume of fluid to flow through an opening is recorded. at 30[degrees]C and with a Haake RS100 cone and plate viscometer, fitted with a cone C20/4 (diameter 2 cm) at 30[degrees]C.
* The yield value, expressed in Dynes/[cm.sup.2], is determined using the Laray viscometer.
* Gloss gloss [Gr.,=tongue], explanatory note on a word or words of a text, usually written between the lines or in a margin of a manuscript. In copying a manuscript, a copyist sometimes incorporated a gloss in the text, so that the copy departed from the original. reading is taken from weighed prints at a 60[degrees] angle.
* The reactivity is checked by chemical resistance to methyl ethyl ketone methyl ethyl ketone
methyl ethyl ketone
Noun 1. methyl ethyl ketone (MEK Noun 1. MEK - a terrorist organization formed in the 1960s by children of Iranian merchants; sought to counter the Shah of Iran's pro-western policies of modernization and opposition to communism; following a philosophy that mixes Marxism and Islam it now attacks the ) and ethanol.
* Water pick-up Duke test
This method is used for the determination of the amount of water picked up by a lithographic printing ink in a laboratory mixer mixer, either of two electronic devices in which two or more signals are combined. In the type of mixer used in radio receivers, radar receivers, and similar systems, a signal is translated upward or downward in frequency. . This laboratory mixer, such as a Duke Ink Water Emulsification Tester, is equipped with a stainless steel stainless steel: see steel.
Any of a family of alloy steels usually containing 10–30% chromium. The presence of chromium, together with low carbon content, gives remarkable resistance to corrosion and heat. bowl and with mixer blades rotating ro·tate
v. ro·tat·ed, ro·tat·ing, ro·tates
1. To turn around on an axis or center.
2. at 90 rounds/mm.
For a single-point water pick-up, 50 grams of UV ink are mixed with 50 grams of press fountain solution (Aqualite SM 95 from SIOPA + 6 % of Isopropanol isopropanol, isopropyl alcohol, or 2-propanol (ī'səprō`pənōl, ī'səprō`pĭl), (CH3)2CHOH, a colorless liquid that is miscible with water. ) during one minute on the Duke. The water pick-up is determined by weighing the quantity of free water.
* Tack measurements
Tack and misting are measured at 30[degrees]C on the Tack-o-Scope instrument from Testprint, using 0,6 g of ink. The water balance of the UV offset inks is checked on the W model. The instrument is fitted with a system allowing the controlled delivery of the fountain solution (or water). This system consists of a roller placed in a duct, which holds the dampening solution from the water duct to the center roller. The roller can be placed in contact with, or removed from, a chromium chromium (krō`mēəm) [Gr.,=color], metallic chemical element; symbol Cr; at. no. 24; at. wt. 51.996; m.p. about 1,857°C;; b.p. 2,672°C;; sp. gr. about 7.2 at 20°C;; valence +2, +3, +6. spiralled brass centre roller by means of a lever.
Thus the water/ink behavior influences the tack value of the emulsified ink, the stability, and the rate of up-take or release of water during the test.
* Lithotronic test method
The lithotronic measuring instrument operates like a rotational viscometer, giving the viscosity behavior of a sample of ink under high shear shear: see strength of materials.
A straining action wherein applied forces produce a sliding or skewing type of deformation. conditions. A defined amount of printing ink (25 g) is placed in a beaker beaker /beak·er/ (bek´er) a glass cup, usually with a lip for pouring, used by chemists and pharmacists.
a round laboratory vessel of various materials, usually with parallel sides and often with a pouring spout. and the fountain solution is added at a specific stirring speed and flow. The torque at the propeller propeller, device consisting of a hub with one or more blades that propels a craft to which it is attached by rotating its blades in a fluid such as air or water. is measured as a function of the amount of added fountain solution.
* Contact angle
The contact angle is measured by placing a drop of fountain solution on an ink film and measuring the tangent tangent, in mathematics.
1 In geometry, the tangent to a circle or sphere is a straight line that intersects the circle or sphere in one and only one point. of the angle at the point of contact between the fountain solution droplet droplet
very small drop of fluid.
the finite particles of matter which are transmitted from animal to animal. and the ink.
Sheetfed Press Performance
UV offset printability was carried out on a sheetfed offset press Roland Favorit (see Table 2).
Physical Characterization Of the Monomers
The interface between the fountain solution and the ink is complex: it means that the ink has to exhibit the right hydrophobic/hydrophilic balance.
On the one hand, a certain water uptake uptake /up·take/ (up´tak) absorption and incorporation of a substance by living tissue.
n. is required to achieve good handling features of the ink. For this purpose, the interfacial tension between the ink and the fountain solution must not exceed a value of approximately 10 mN/m.
On the other hand, the ink must not be too soluble soluble /sol·u·ble/ (sol´u-b'l) susceptible of being dissolved.
Capable of being dissolved, especially easily dissolved. in the fountain solution: the interfacial tension must not be lower than 0.5 to 1 mN/m. (6)
Interfacial tension measurements allow us to anticipate the differences observed in ink performances with the same type of monomer.
On Table 3, the values of surface tension and interfacial tension for several monomers are given. The first remark is that there is no correlation between surface tension and interfacial tension with water. Surface tension corresponds to the interface of the monomer with air, which highlights the hydrophobic part of the monomer. On the contrary, the interfacial tension with water is more related to the hydrophilic part of the monomer.
An important factor that influences interfacial tension is the nature of the medium. Examples are given on Table 4, when isopropanol and surfactants are added to water. Addition of isopropanol in water leads to a lower interfacial tension than in pure water.
We have synthesized various GPTA in order to have different behaviors with water (see Table 4). GPTA-SP1 is more hydrophilic as it exhibits a lower interfacial tension with water. GPTA-SP2 is more hydrophobic. The more hydrophilic OPTA OPTA Onafhankelijke Post en Telecommunicatie Autoriteit
OPTA Optimum Performance Theoretically Attainable
OPTA Orthotic & Prosthetic Technological Association
OPTA Open Packet Telephony Architecture (Cisco) (GPTA-SP1) presents a higher hydroxyl hydroxyl /hy·drox·yl/ (hi-drok´sil) the univalent radical OH.
The univalent radical or group OH, a characteristic component of bases, certain acids, phenols, alcohols, carboxylic value.
Results and Discussion
First the contact angles between the fountain solution and the ink films were measured and compared for both magenta inks. The lower the contact angle between the fountain solution and the ink, the higher the hydrophilicity of the ink.
Unfortunately, no obvious difference was noticed among the contact angle values after 30 seconds to 3 minutes. In this case, the contact angle method can not differentiate between the two grades of GPTA in a static condition (Table 5).
The laboratory results obtained for the UV inks based on GPTA-SP1 and GPTA-SP2 (Table 6) demonstrate that there is no impact of interfacial tension on the rheological rhe·ol·o·gy
The study of the deformation and flow of matter.
rheo·log properties (viscosity and yield value), wetting characteristic (gloss) and UV reactivity (alcohol and MEK resistance).
On the contrary, the Duke tests and the tack measurements are dependent on interfacial tension.
A correct water uptake is one of the critical properties required to achieve satisfactory lithographic print quality with LIV offset printing inks. The aim is to obtain and keep the proper ink-water balance during the printing process. This can be simulated with the Duke and Tack-o-Scope measurements.
The ink-water interaction for GPTA-SP1 confirmed its hydrophilic behavior: the water pick-up with the Duke test increased of 3.6% compared to GPTA-SP2, and the tack value obtained after the first contact with the fountain solution is increased from 140 to about 240 points (+ 70%). In the same conditions, the tack value is increased only 14% in the case of GPTA-SP2.
The time values of de-inking and recovery of the center roller chromium spiral of the Tack-o-scope are presented in Table 7 for both inks.
It can be noted that the ink based on GPTA-SP1 requires much more time to de-ink the spiral. For example, 70 seconds are required for the fountain solution to completely clean the hydrophilic chromium spiral during the first water contact. This is due to the great affinity between the ink and water, as an excessive water compatibility is known to result in serious printing problems like toning (the printing ink is transferred to the non-image areas). For the ink based on GPTA-SP2, the time of de-inking is equivalent to a standard value for UV offset printing inks.
The recovery time is measured between the water withdrawn and the full re-inking of the spiral. Due to its water affinity, the ink based on GPTA-SP1 took more time for the recovery.
The strong fountain solution tinting tint
1. A shade of a color, especially a pale or delicate variation.
2. A gradation of a color made by adding white to it to lessen its saturation.
3. A slight coloration; a tinge.
4. in the case of GPTA-SP1 demonstrated again its hydrophilic behavior: the magenta pigment pigment, substance that imparts color to other materials. In paint, the pigment is a powdered substance which, when mixed in the liquid vehicle, imparts color to a painted surface. (color index color index, in astronomy, difference in an object's brightness as recorded between any two well-defined bands of the electromagnetic spectrum by using optical filters of different colors. PR 57/1 which is normally non-soluble in water) is transferred to the water phase.
Five different water contacts were made during the laboratory trial and an increasing tack was observed after each water contact. A continuous tack increase is related to a lower film thickness due to the transfer of the ink in water. A lower film thickness increases the force required to split the ink film and consequently increases the tack value.
From the lithotronic experiments, we measure the emulsification capacity (EC), which is the percentage (% w/w) of emulsified water in the ink (before the strong drop in torque). The EC for the ink based on GPTA-SP1 is 44,2 % and 47,5 % for the GPTA-SP2 ink, indicating a higher capacity for water emulsification without rheological modification. Moreover, the lithotronic curve of the magenta ink based on GPTA-SP1 gives a flat curve which indicates a sensitive behavior towards offset printing according to our experience (after comparison to laboratory and practical information from our printers). The ink based on GPTA-SP2 displays an increasing curve during the water pick-up which is more in line with "good" UV binders for litho application.
In order to compare all these results, obtained with simple laboratory methods, to the behavior on an offset printing press, printing trials were carried out with the two UV magenta inks on a Man Roland MAN Roland is a German sheetfed and web press manufacturer. MAN is an abbreviation for Maschinenfabrik Augsburg-Nürnberg (German: Machine Works of Augsburg and Nürnberg). Full company name: MAN Roland Druckmaschinen AG. sheetfed printing machine.
The printing trials were performed for both magenta inks with an optical density between 1,4 and 1,7. The red ink red ink Health administration A popular term for financial losses. Cf in the Black. based on GPTA-SP2 confirmed a good offset printability. The ink formulated with the monomer GPTA-SP1 displayed a very sensitive runnability, as the lithographic behavior arid ar·id
1. Lacking moisture, especially having insufficient rainfall to support trees or woody plants: an arid climate.
2. the water ink balance were not easy to maintain and as some toning appeared during the trials (see Figure 1).
Thanks to various tests (tensiometry, tack measurements, Duke and Lithotronic tests) on UV offset inks based on two GPTAs (GPTA-SP1 and GPTA-SP2), we have succeeded in predicting the water/ink balance and in giving a clear statement of the printability of the UV offset ink.
It appears that interfacial tension is one of the key parameters in the raw material selection for the ink formulator, as it influences the water uptake, the tack value, and the runnability (toning phenomenon).
In the near future, these methods of characterisation based on interfacial tension determination will be used for UV binders having medium to high viscosity.
[FIGURE 1 OMITTED]
Table 1 UV offset ink recipe. Composition of the Magenta UV Offset Ink Epoxy acrylate 22.5% Modified polyurethane acrylate 30.5% Liquid photoinitiator blend 5% UV stabilizer 1% Fillers 2% Magenta Irgalite 20% GPTA 19% Table 2 Characteristics of the sheetfed press Man Roland. Running speed 3000-12000 sheets/hour Sheet dimension 52 cm x 72 cm Print dimension 49 cm x 62 cm Number of printing units 2 Fountain solution SM95 + 6% IPA UV lamps: Spectral Cold Systems 2 x 140 W/cm Table 3 Surface tension of acrylate monomers and interfacial tension with water. Monomers Surface tension * (mN/m) Neopentylglycol propoxylated diacrylate (SR9003) 31 2ethoxyethoxyethyl acrylate (SR256) 32 Tripropylene glycol diacrylate (SR306) 32.5 Propoxylated Trimethylopropane triacrylate (SR492) 33.5 Propoxylated Glyceryl triacrylate (SR9020) 34.5 Hexanediol diacrylate ((SR238) 35 Trimethylopropane triacrylate (SR351) 36 Ethoxylated trimethylol propane triacrylate (SR454) 37.5 Ethoxylated pentaerythritol tetraacrylate (SR494) 38 Tatraethyleneglycoldiacrylate (SR268) 39.5 Polyethyleneglycoldiacrylate (SR344) 41 Monomers Water/monomer interfacial tension (mN/m) Neopentylglycol propoxylated diacrylate (SR9003) 9.4 2ethoxyethoxyethyl acrylate (SR256) Water-soluble Tripropylene glycol diacrylate (SR306) 7.9 Propoxylated Trimethylopropane triacrylate (SR492) 8.3 Propoxylated Glyceryl triacrylate (SR9020) 6.5 Hexanediol diacrylate ((SR238) 11.2 Trimethylopropane triacrylate (SR351) 13.5 Ethoxylated trimethylol propane triacrylate (SR454) 8.5 Ethoxylated pentaerythritol tetraacrylate (SR494) 4.9 Tatraethyleneglycoldiacrylate (SR268) Water-soluble Polyethyleneglycoldiacrylate (SR344) Water-soluble Monomers Viscosity (mPa.s) Neopentylglycol propoxylated diacrylate (SR9003) 17 2ethoxyethoxyethyl acrylate (SR256) 5 Tripropylene glycol diacrylate (SR306) 15 Propoxylated Trimethylopropane triacrylate (SR492) 120 Propoxylated Glyceryl triacrylate (SR9020) 110 Hexanediol diacrylate ((SR238) 8 Trimethylopropane triacrylate (SR351) 100 Ethoxylated trimethylol propane triacrylate (SR454) 80 Ethoxylated pentaerythritol tetraacrylate (SR494) 150 Tatraethyleneglycoldiacrylate (SR268) 20 Polyethyleneglycoldiacrylate (SR344) 60 * Measurements done with the Du Nouy ring method Table 4 Surface tension and interfacial tension (IFT) of the synthesized GPTA. Monomer Viscosity Surface IFT monomer/ IFT monomer/ tension water (mNm) water + 10% (mN/m) Isopropanol (mN/m) GPTA-SP1 125-135 34 3.1 1.9 GPTA-SP1 125-135 34 3.1 1.9 Monomer IFT monomer/ Acid value Hydroxyl value fountain solution (mg KOH/g) (mg KOH/g) (mN/m) GPTA-SP1 2 <0.1 75 +- 1 GPTA-SP1 2 <0.1 75 +- 1 Table 5 Contact Angle. Time 15" 1' 2' 3' Magenta SP1 62[degrees] 60[degrees] 58[degrees] 57[degrees] Magenta SP2 63[degrees] 60[degrees] 59[degrees] 57[degrees] Table 6 Inks evaluation. Laboratory properties Magenta UV offset ink based on GPTA -- SP1 GPTA -- SP2 Viscosity in Laray 14 13.8 Pa. s at 30[degrees]C Haake/50s - 1 29,3 30,3 Yield value (dynes/ cm_) 5500 5500 Tack 1 min 135 140 Gloss (%) at OD from 1,8 to 1,7 32.8 30.1 Reactivity in rubs MEK 10 8 Alcohol 40 35 Tack increase: first water +70% +14% contact Duke: water pick-up 29.4% 25.8% Table 7 Litho tack behavior. UV Inks Magenta based on SP1 Litho-Tack De-inking * Recovery time * First contact 70 90 Second contact 25 60 Third contact 6 51 Fourth contact 5 48 Fount tinting strong coloration UV Inks Magenta based on SP2 Litho-Tack De-inking * Recovery time * First contact 15 55 Time in Seconds Second contact 5 35 Third contact 5 35 Fourth contact 4 37 Fount tinting moderate coloration * from the chromium spiral
Thanks to Greet Demeyer and Christine Lacroix from SICPA and Helene Godelier from Cray Valley for their kind participation.
(1): G. Faure, "Overview of the UV/EB Inks and Coatings European Market," p 239, Radtech Europe, 1999.
(2): European Printing Inks Market, Frost & Sullivan, 2000, n. 3795-39.
(3): K. Alam & M.R. Kamal, p.1955, ANTEC '99.
(4): Standard Test Methods for Water Pickup of Lithographic Printing Inks, ASTM ASTM
American Society for Testing and Materials , 1989.
(5): "Studying the Behavior of Emulsions is Valuable and Beneficial for Your Inks," PPCJ PPCJ Polymers Paint Colour Journal , Sept 1999,28-30
(6): J.U. Ziller, Kruss GmbH, Application Note # 207.
Dr. Benoit Magny was educated at the Ecole Nationale Superieure de Chimie de Paris, where he gained an engineer diploma in chemistry in 1988. He earned his Ph.D. in 1992 at the Ecole Superieure de Physique physique /phy·sique/ (fi-zek´) the body organization, development, and structure.
The body considered with reference to its proportions, muscular development, and appearance. et Chimie Industrielles de Paris.
Since then, he has been working at the Research Center of Verneuil as a research scientist for the resin division in the Atofina organization. Dr. Magny is now research group manager of the physico-chemistry, analysis and characterization team.
Dr. Gilles Eisele is a chemical engineer from the High School of Chemistry from Mulhouse. Dr. Eisele is graduated in photochemistry photochemistry, study of chemical processes that are accompanied by or catalyzed by the emission or absorption of visible light or ultraviolet radiation. A molecule in its ground (unexcited) state can absorb a quantum of light energy, or photon, and go to a from the University of Haute-Alsace, France. During his industrial Ph.D., he spent three years at the laboratory of Professor Fouassier and at the Rhodia Research Centre of Aubervilliers.
In 1995, Dr. Eisele joined SIOPA commercial inks division based in Annemasse, France. There, he assumed responsibilities in R&D. At present, he is division R&D manager for UV binders and polyurethane polyurethane
Any of a class of very versatile polymers that are made into flexible and rigid foams, fibres, elastomers (elastic polymers), surface coatings, and adhesives. resins for the SICPA Group.
Glenn Albrighton is the technical service manager for inks and graphic arts within the photocure and functional additives department of Cray Valley, Verneuil, France. After completing his BSc in applied chemistry from Lanchester Polytechnic, Mr. Albrighton worked for several years in the ink industry.
Prior to taking his current role in April 1999, Mr. Albrighton served as the general technical manager of Bousfield Printing Inks & Coating, Bristol, England. He is also a member of the Graphic Arts Working Group for RadTech, Europe.
Dr. Sophie Mouzon-Pelletier was educated at the Ecole Nationale Superieure de Chimie et de Physique de Bordeaux, France, where she earned an engineer diploma in physico-chemistry in 1996. Dr. Mouzon-Pelletier earned her Ph.D. in 1999 at the Ecole Nationale Superieure des Industries Chimiques, Nancy, France.
Since then, Dr. Mouzon-Pelletier has been working as a research scientist in the physico-chemistry, analysis and characterization team at the Research Centre of Cray Valley, resin division of the Atofina organization.