what are the scientific chemicals measures we use to test fountain solution
Fountain Solution and Fountain Solution Concentrates Specification The present invention relates to fountain solutions and a fountain solution concentrate for use in offset printing and methods for their manufacture. The nowadays invention besides refers to the use of tert.-amyl alcohol in fountain solutions or fountain solutions concentrates for offset printing. In addition the nowadays invention refers to a method for offset printing wherein a fountain solution according to the present invention is applied to the image plate to desensitize the non-epitome areas of the image plate as well as to printed media obtained with this method.
First press is a unremarkably used printing technique where the inked epitome is transferred (or "offset") from a lithographic plate to a rubber coating, and then to the press sur- confront.
In offset printing, the lithographic plate is designed in such as fashion that the positive image areas have a hydrophilic surface while the negative image areas have a hydrophobic surface.
The lithographic plate is generally treated with a then called fountain solution. The foun- tain solution is usually a hydrophilic water based composition which adheres to the hydrophilic non-image areas of the lithographic plate. The treatment of the lithographic plate with a fountain solution insures that the hydrophobic ink solutions which are applied in the next processing step only adhere to the hydrophobic imaging areas of the plate. The function of the fountain solution is therefore to desensitize the non-image areas rendering them ink-repellent.
Commonly known fountain solutions comprise water, brine metallic table salt or ammonium salt of dichromic acid, phosphorous acrid or salts of phosphorous acid and a colloidal substance, such equally gum arabic or carboxymethyl cellulose (CMC).
Solutions based on these substances lone take the disadvantage that they do not moisture the not-image areas of the press plate sufficiently.
If too little fountain solution is applied, the nonprinting areas will not accept plenty moisture and volition accept some ink, which subsequently volition be transferred to the newspaper. On the other mitt, if too much fountain solution is practical to the plate, it will dilute the ink and crusade the printed epitome to have a done-out advent.
If the fountain solution is practical unevenly, so that as well piffling fluid is applied to some portions of the plate and too much is practical to other portions of the plate, the final printed image will take some undesired areas inked and other areas wherein the image is done out.
Therefore a considerable amount of skill and experience is required in controlling the feed rate of such fountain solutions to the printing plate.
To overcome this problem, a wetting amanuensis is normally added to the fountain solution. A wetting amanuensis reduces the surface tension of the fountain solution allowing the rapid formation of a thin, fifty-fifty film of the fountain solution on the non-image areas. Dahlgren (U.s. three,705,451 ) has suggested the use of isopropyl booze as a wetting agent and fountain solutions known as "Dahlgren systems" accept become standard in the industry.
The use of isopropyl alccohol in fountain solutions has many advantages in add-on to reducing surface tension. Information technology also increases the viscosity of the solution allowing a thicker movie to be practical to the rollers and/or the plate. The high volatility of isopropyl alcohol ways that it will evaporate more quickly before being transferred to the blanket minimizing wash out furnishings and ink-haemorrhage. Its tendency to emulsify the ink to a bottom extent than other liquids reduces snowflaking (modest, white, unprinted specks in printed solids and type). In add-on, isopropyl booze tends to allow greater print quality right at startup, which is a cost-effective benefit.
However, Environmental Protection Agency (EPA) and Occupational Rubber and Wellness Administration (OSHA) regulations (such as those calling for the reduction of volatile organic compounds) are limiting the use of isopropyl alcohol in fountain solutions. For instance, measures must be taken when concentrations of v% past weight or greater are used, such equally installation of ventilation, measurements of the working environs and wellness checks of workers. Several of the disadvantages of isopropyl alcohol - such as its expense, toxicity, flammability, and need for adequate ventilation in areas of its apply - are causing substitutes to be more frequently utilized.
These substitutes include polyhydric alcohols, glycol, glycol ethers and derivatives thereof frequently in combination with ethylene glycol (e.g. US iii,877,372 or US five,695,550). These substitutes can either completely supplant isopropanol or they can be added as a supplement to it, reducing the total isopropanol concentration.
US 2009/0081592 mentions fountain solution compositions comprising at to the lowest degree one acyclic hydrocarbon diol chemical compound, having 6 to eight carbon atoms in total and two hydroxyl groups at the 1 - and 2-positions, respectively.
U.s.a. four,278,467 discloses a fountain solution containing at least 1 member selected from the grouping consisting of n-hexoxyethylene glycol, north-hexoxydiethylene glycol, 2- ethyl-i ,3-hexanediol, n-butoxyethylene glycol acetate, n-butoxydiethylene glycol acetate and 3-butoxy-2-propanol.
Fountain solutions comprising 2-ethyl-one ,iii-hexanediol and at to the lowest degree ane member selected from the group consisting of propylene glycol, ethylene glycol, dipropylene glycol, diethylene glycol, hexylene glycol, Methylene glycol, tetraethylene glycol, tripropane glycol and 1 ,5-pentanediol are mentioned in U.s. 4,560,410.
As these fountain solutions do non incorporate isopropyl alcohol, they are preferable in view of safety and hygiene. However, the wettablility with respect to non-image areas of a lithographic printing plate during press operation is not sufficient and information technology is sometimes observed that the non-image areas are contaminated, in particular, during high speed printing operation. This may cause and then-called ink spreading of half dot image portions, a phenomenon wherein the shape of half dot images is abnormally plain-featured. Moreover, 2-ethyl-1 ,three-hexanediol is not sufficient soluble in water and thus the utilize thereof is unfavorable to obtain a fountain solution concentrate or an additive for a fountain solution having a high concentration.
US five,106,414 discloses fountain solutions consisting of aliphatic alcohols or diols having 5 to ane 1 carbon atoms to which 1 to 10 units of ethylene oxide are added. A similar fountain solution is mentioned in U.s.a. v,308,388 in which alkanols, alkenols or al- kanediols or alkenediols having 5 to fifteen carbon atoms are converted with 3 to 12 ethylene oxide and or propylene oxide units. Such substitutes are added to the fountain solutions in low amounts which have lilliputian effect on the viscosity of the fountain solution. Therefore college roller speeds in continuous-flow dampening systems are required when using such solutions.
The object of the nowadays invention was to provide a fountain solution which allows for an excellent print reproducibility, east.g. an exact transfer of the image to the printed medium. Therefore it was an object of the present invention to provide a fountain solution which minimizes bleeding. Information technology was also an object of the present invention to provide a fountain solution which allows a smooth operation in beginning printing, due east.1000. a minimizing of ink piling on the blanket. Another aim of the present invention was to provide a fountain solution with enables proper emulsification of the ink, e.g. to forestall over- emulsification, which may result in unclear images or images having voids or to prevent insufficient water uptake (poor emulsification), which in turn may result in poor ink transfer and ink piling on the blanket. It was also intended to enable a college throughput during press operations. Therefore it was the aim to provide a fountain solution having a low dynamic surface tension in order to enhance the desensitizing properties and a sufficiently high dynamic viscosity to permit an fifty-fifty distribution of fountain solution on the epitome plate. In addition it was intended to provide a fountain solution having a wetting agent showing a reasonable tendency to evaporate in order to minimize wash out effects and ink-bleeding. A still further object of the present invention is to provide a fountain solution or a fountain solution concentrate which is not subject area to current health and ecology regulations.
The object of the present invention is solved by a fountain solution for offset printing comprising water and tert.-amyl alcohol (2-methyl-two-butanol).
The present invention besides relates to a fountain solution concentrate for offset printing which can exist diluted with water to provide a set-to-utilize fountain solution according to the present invention. The advantage of providing a fountain solution concentrate is that water must not be transported from the manufacturer of the concentrate to the operator of the printing machine. The fountain solution concentrate of the present invention comprises tert.-amyl booze (two-methyl-2-butanol).
The fountain solution concentrate comprises 10 to 100% by weight of tert.-amyl alcohol, preferably 20 to 95% by weight, more preferably 5 to 75% by weight, even more than preferably between 7,5 to 60% by weight and near preferably 10 to fifty% by weight.
As well tert.-amyl alcohol, the fountain solution concentrate may too comprise auxiliary wetting agents.
Preferably the auxiliary wetting agents are surfactants or auxiliary wetting solvents, which are miscible with tert.-amyl alcohol.
Surfactants are preferably nonionic, anionic surfactants, N-alkylpyrrolidones and acetylene alcohols and their derivatives.
Preferable anionic surfactants are fatty acid salts, abietate, hydroxyalkanesulfonate, alkanesulfonate, dialkyl sulfosuccinate, linear alkylbenzene sulfonate, branched alkyl- benzene sulfonate, alkylnaphthalenesulfonate, alkylphenoxy polyoxyethylene propyl- sulfonate, polyoxyethylene alkylsulfenyl ether salt, N-methyl-N-oleyl taurine sodium salt, N-alkyl sulfosuccinic acrid monoamide disodium table salt, petroleum sulfonate, sulfated brush oil, sulfated beef tallow oil, sulfuric ester salt of fatty acrid alkyi ester, alkyi sulfuric acrid ester table salt, polyoxyethylene alkyi ether sulfuric ester salt, fatty acrid monoglyceride sulfuric ester salt, polyoxyethylene alkylphenyl ether sulfuric ester salt, polyoxyethylene styrylphenyl ether sulfuric ester table salt, alkyi phosphoric ester common salt, polyoxyethylene alkyi ether phosphoric ester salt, polyoxyethylene alkylphenyl ether phosphoric ester salt, partially saponified product of styrene-maleic anhydride copolymer, partially saponified product of olefin-maleic anhydride copolymer, naphthalene sulfonate formalin condensate and the like.
Preferable nonionic surfactants are polyoxyethylene alkyi ether, polyoxyethylene alkylphenyl ether, polyoxyethylene polystyrylphenyl ether, polyoxyethylene polyoxypropyl- ene alkyi ether, glycerol fatty acid partial ester, sorbitan fatty acrid partial ester, pentae- rythritol fatty acid partial ester, propylene glycol mono fatty acid ester, sucrose fatty acid partial ester, polyoxyethylene sorbitan fat acid partial ester, polyoxyethylene sorbitol fat acid partial ester, polyethylene glycol fatty acid ester, polyglycerin fatty acid partial ester, polyoxyethylenated castor oil, polyoxyethylene glycerol fatty acid partial ester, fatty acid diethanol amide, North,N-bis-ii-hydroxy alkylamine, polyoxyethylene al- kylamine, triethanolamine fatty acid ester, trialkylamine oxide and the similar. In addition, fluorochemical surfactants and silicon surfactants may be used.
Preferable N-alkylpyrrolidones are North-ethyl pyrrolidone, N-butyl pyrrolidone, North- pentylpyrrolidone, N-hexylpyrrolidone, N-octylpyrrolidone and Due north-laurylpyrrolidone. Preferable acetylene alcohols and their derivatives are 3,five-dimethyl-ane -hexyne-3-ol, ii,5- dimethyl-three-hexyne-2,5-diol, two,iv,7,9-tetramethyl-5-decyne-four,7-diol, iii,6-dimethyl-four- octyne-3,6-diol, 2-butyne-1 ,four-diol, 3-methyl-one -butyne-iii-ol, adduct compounds of ethylene oxide and/or propylene oxide to the higher up acytelene alcohols, such every bit ethoxylated ii,four,7,9-Tetramethyl-five-decyn-iv,seven-diol (available asSurfynol ® 440), and the like. Among these, iii,6-dimethyl-4-octyne-3,6-diol, two,4,7,9-tetramethyl-five-decyne-4,vii-diol, and an adduct compound of 4 to 10 ethylene oxides to two,4,7,9-tetramethyl-five-decyne-4,7-diol are preferable.
In addition, combination of two or more than surfactants tin can be employed.
The amount of surfactants based on the total weight of the fountain solution
concentrate is generally between 0 to fifteen% by weight, preferably 1 to x% by weight and more preferably three to 8% past weight. The auxiliary wetting solvent is a solvent which fully or at least partly miscible with tert- amyl alcohol.
Preferably, the auxiliary wetting solvent existence miscible with tert.-amyl alcohol are alcohols, ethers of polyhydric alcohols, such as adducts of polyhydric alcohols with ethylene or propylene oxide.
More preferably auxiliary wetting solvent having a miscibility with tert.-amyl alcohol are selected from the group consisting of north-propyl alcohol, n-pentyl booze, 2-methyl-1 - butanol, 2,2-dimethyl-1 -propanol, 2,2-dimethyl-ii-propanol, 1 -pentanol, 2-pentanol, 3- pentanol, 2-methyl-one -butanol, 3-methyl-1 -butanol, ii-methyl-2-butanol, 3-methyl-2- butanol, 1 -octanol, 2-octanol, 2-ethylhexanol, ethylene glycol, ethylene glycol mono- isopropyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol mono-due north-butyl ether, ethylene glycol mono-tertiary-butyl ether, diethylene glycol, diethylene glycol mono-n-butyl ether, diethylene glycol monoethyl ether, propylene glycol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n- propyl ether, propylene glycol mono-n-butyl ether, propylene glycol monoisobutyl ether, dipropylene glycol, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol isobutyl ether, Methylene glycol, Methylene glycol monomethyl ether, Methylene glycol monoethyl ether, Methylene glycol monobutyl ether, butylene glycol, glycerine, three-methoxy-three-methylbutane. The amount of auxilliary wetting solvent having a miscibility with tert.-amyl alcohol based on the total weight of the fountain solution concentrate is generally betwixt 0 to threescore% by weight, preferably 5 to 55% by weight more preferably 10 to 50% by weight and virtually preferably 15 to 50% by weight.
In a preferred embodiment, the fountain solution concentrate comprises less than 10% past weight, preferably less than 5% by weight and most preferably less than 1 % past weight of isopropyl alcohol. Most preferably the fountain solutions and fountain solutions concentrates co-ordinate to the present invention do non comprise isopropyl alcohol. In a further preferred embodiment of the present invention, the fountain solution concentrate co-ordinate to the present invention too comprises h2o. The amount of water based on the full weight of the fountain solution concentrate is generally betwixt 0 to 75% by weight, preferably 5 to 75% by weight, more preferably seven.five to lx% past weight and most preferably fifteen to 55% by weight
The fountain solution co-ordinate to the present invention may optionally also incorporate desensitizing agents, pH-adjusting agents, chelating agents and other additives, such as odor masking agents, preservatives, anti-corrosives, anti-foaming agents etc.. The corporeality and pick of additional components depends on the application surface area and printing prepare and is known to a person skilled in the art. The fountain solution concentrate may optionally comprise a desensitizing agent to impart to non-paradigm areas water-receptivity and ink-repellency.
Examples of the aqueous desensitizing agent include aqueous solutions of water soluble natural polymers such equally mucilage standard arabic, dextrin and carboxymethyl cellulose, and aqueous solutions of water soluble synthetic polymers such every bit polyvinyl alcohol, poly- vinyl pyrrolidone and polyacrylic acid.
The corporeality of desensitizing amanuensis in the fountain solution concentrate is preferably in the range of 0 to 15% by weight, more preferably 1 to 10% by weight and most preferably 3 to 8% by weight based on the weight of the fountain solution concentrate. The fountain solution concentrate may additionally comprise a pH-adjusting amanuensis. pH adjusting agents may exist used to adjust a specific pH-range in the fountain solution or to buffer the fountain solution.
Fountain solutions are preferably slightly to moderately acidic, e.m. in the pH-range of 3 to 7, if desensitizing agents such as glue arabic is used because gum arabic may lose its effectiveness if the pH rises above five . In this case, it may lose its ability to adhere to the plate, and ink may begin to adhere to the plate in the non-image areas, a problem known equally scumming. However, excessive acidity tin can also cause scumming (as the acid eats away the protective plate coating), as well as plate blinding, in which the acid eats abroad the image areas of the plate, causing a lack of ink receptivity. Increased acidity tin also cause roller stripping, or the lack of ink receptivity of the ink rollers. Fountain solutions are preferably slightly alkaline, e.g. in the pH-range of vii to i 1 , if alkaline paper or newspaper containing calcium carbonate either every bit a filler or a blanket is used in the printing procedure. Calcium carbonate is an alkali metal fabric, and when particles of information technology come into contact with an acidic fountain solution, deleterious effects tin can occur. If slightly alkaline fountain solutions are desired, it is additionally preferred non to employ glue as a desensitizing amanuensis.
pH-adjusting agents are normally h2o-soluble organic and/or inorganic acids and/or salts thereof.
Preferable organic acrid includes, for example, citric acid, ascorbic acid, malic acid, tar- taric acid, lactic acrid, acerb acid, gluconic acid, acetic acid, hydroxyacetic acid, oxalic acid, malonic acid, levulinic acid, sulfanilic acrid, p-toluenesulfonic acid, phytic acid, an organic phosphonic acrid and the like. Preferable inorganic acid includes phosphoric acid, nitric acid, sulfuric acid, polyphos- phoric acrid and the like.
In addition, brine metal salts, alkaline earth metal salts, ammonium salts or organic amine salts of these organic and/or inorganic acids, in peculiarly brine metal carbon- ates, element of group ii carbonates, element of group i silicates or alkaline earth metal silicates, especially sodium carbonate or sodium silicate, can exist preferably used, and such organic and inorganic acids and salts thereof can be used either alone or in combination of more one.
The amount of pH-adjusting amanuensis based on the total weight of the fountain solution concentrate is mostly betwixt 0 to xv% by weight, preferably ane to ten% by weight and most preferably 3 to 8% by weight.
The fountain solution concentrate may optionally as well incorporate a chelating agent.
A chelating agent is generally used as a h2o softener to bind calcium ions which may adversely affect the printing process.
Examples of preferred chelating agents include ethylenediaminetetraacetic acid and potassium salts and sodium salts thereof; diethylenetriaminepentaacetic acid and potassium salts and sodium salts thereof; triethylenetetraminehexaacetic acid and potassium salts and sodium salts thereof; hydroxyethylethylenediaminetriacetic acrid and potassium salts and sodium salts thereof; nitrilotriacetic acrid and sodium salts thereof; organic phosphonic acids such every bit 1 -hydroxy ethane-one ,1 -diphosphonic acid and potassium salts and sodium salts thereof; aminotri (methylenephosphonic acid) and potassium salts and sodium salts thereof, and phosphonoalkanetricarboxylic acids.
Organic amine salts may also be used as chelating agents.
The corporeality of chelating agent based on the total weight of the fountain solution concentrate is generally between 0 to 5% by weight, preferably 0.i to ii.5% by weight and most preferably 0.three to 1 % by weight of a chelating agent.
In addition, the fountain solution concentrate may as well comprise other additives, such every bit odor masking agents, preservatives, emmet-corrosives, anti-foaming agents, surface active agents etc..
Odor masking agents include esters which are conventionally known to be used equally flavors. Specific examples of olfactory property masking agents which may exist used include esters of formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, 2-ethylbutyric acrid, valeric acid, isovaleric acid, two-methylvaleric acrid, hexanoic acid (caproic acid), 4- methylpentanoic acrid (isohexane acid), 2-hexenoic acid, 4-pentene acid, heptanoic acid, 2-methylheptane acid, octanoic acrid (caprylic acid), nonanoic acid, decanoic acrid (capric acid), 2-decenoic acid, lauric acid or myristic acrid. In addition, odor masking agents as well includes acetoacetic esters such equally benzyl phenylacetate, ethyl acetoace- tate and ii-hexyl acetoacetate. Among these, northward-pentyl acetate, isopentyl acetate, n- butyl butyrate, n-pentyl butyrate and isopentyl butyrate are preferred and, in particular, n-butyl butyrate, n-pentyl butyrate and isopentyl butyrate are preferred.
Preservatives which may be used for the fountain solution concentrate of the present invention include phenol or derivatives thereof, formalin, imidazole derivatives, sodium dehydroacetate, iv-isothiazolin-iii-one derivatives, benztriazole derivatives, derivatives of amidine or guanidine, quaternary ammonium table salt, pyridine, derivatives of quinoline or guanidine, derivatives of diazine or triazole, derivatives of oxazol or oxazin, bromonitro alcohols such as bromonitro propanol, 2,2-dibromo-ii-nitro ethanol, 3-bromo-iii-nitro pentane ii,iv-diol, and the like. Preferable corporeality of the preservative to be added is such that stably exhibit its effect on bacteria, fungi, yeasts and the similar, and varies with the types of the bacteria, fungi and yeasts.
Anticorrosives which may be used for the invention include benzotriazole, v- methylbenzotriazol, thiosalicylic acid, benzimidazole and derivatives thereof and the like.
The amount of other additives based on the full weight of the fountain solution concentrate is by and large between 0 to15% by weight, more than preferably one to ten% by weight and nearly preferably 3 to 8% by weight, based on the weight of the fountain solution concentrate.
In a preferred apotheosis, the fountain solution concentrate according to the present invention comprises: tert.-amyl booze: 15 to 75% by weight and/or
h2o: 0 to 75% by weight; and/or
auxiliary-wetting solvent: 0 to 60% by weight and/or
desensitizing agents: 0 to xv% by weight and/or
pH-adjusting agents: 0 to fifteen% past weight and/or
chelating agents: 0 to v% by weight and/or
surfactants: 0 to 15% past weight and/or
other additives, including smell masking agents, preservatives, ant-corrosives, anti- foaming agents: 0 to fifteen% by weight,
based on the weight of the fountain solution concentrate.
In some other preferred embodiment the fountain solution concentrate co-ordinate to the nowadays invention more preferably additionally comprises: tert.-amyl booze: vii,5 to 60% by weight and/or
water: v to 75% past weight and/or
auxiliary-wetting solvent: 5 to 55% past weight and/or desensitizing agents: i to 10% by weight and/or
pH-adjusting agents: 1 to x% by weight and/or
chelating agents: 0.1 to 2.5% by weight and/or
surfactants: one to x% by weight and/or
other additives, including smell masking agents, preservatives, ant-corrosives, anti- foaming agents: i to 10% by weight,
based on the weight of the fountain solution concentrate.
In a more than preferred embodiment the fountain solution concentrate according to the present invention more than preferably additionally comprises:
tert.-amyl alcohol: 10 to 50% by weight and/or
water: 7.5 to 60% by weight and/or
auxiliary-wetting solvent: x to 50% by weight and/or
desensitizing agents: 3 to 8% past weight and/or
pH-adjusting agents: 3 to eight% by weight and/or
chelating agents: 0.3 to 1 % by weight and/or
surfactants: iii to 8% by weight and/or
other additives, including odor masking agents, preservatives, ant-corrosives, anti- foaming agents: 3 to viii% by weight,
based on the weight of the fountain solution concentrate.
The fountain solutions concentrates according to the present invention may exist obtained by mixing tert.-amyl alcohol with water and optionally other components, such as desensitizing agent, pH-adjusting agents, chelating agents or other additives, such equally odor masking agents, preservatives, ant-corrosives, anti-foaming agents, etc..
The fountain solution according to the invention is obtained by calculation water to the fountain solution concentrate of the present invention.
The weight ratio of tert.-amyl alcohol to water in the obtainable fountain solutions is preferably in the range of i : 200 to twenty : 100, more preferably in the range of 1 : 100 to 10 : 100 and most preferably 3 : 100 to v : 100.
In a preferred embodiment, the fountain solution co-ordinate to the present invention comprises: tert.-amyl alcohol: 0.1 to 10%, preferably 0.3 to 10% past weight, more than preferably 0.5 to three% by weight and/or
water: l to 99.9% past weight, preferably 70 to 99.5% by weight, more preferably 95 to 99% by weight and/or
auxiliary-wetting solvent: 0 to 5% past weight, preferably 0.05 to 3% by weight, more preferably 0.i to 2% past weight and/or desensitizing agents: 0 to 5% by weight, preferably 0.05 to 3% by weight, more preferably 0.ane to 2% by weight and/or
pH-adjusting agents: 0 to v% by weight, preferably 0.05 to 3% by weight, more preferably 0.one to two% by weight and/or
chelating agents: 0 to one % by weight, preferably 0.01 to 0.5% by weight, more preferably 0.05 to 0.25% by weight and/or
surfactants: 0 to 5% by weight, preferably 0.05 to 3% by weight, more preferably 0.1 to 2% by weight and/or
other additives, including scent masking agents, preservatives, ant-corrosives, anti- foaming agents: 0 to 5% by weight, preferably 0.05 to 3% by weight, more preferably 0.one to 2% by weight based on the weight of the fountain solution concentrate.
The use of tert.-amyl alcohol in fountain solution affords fountains solutions with superior awarding properties.
The fountain solution according to the present invention can easily be practical to the image plates to desensitize the not-image areas of the paradigm plate using standard equipment known to a person skilled in the art. The fountain solution according to the nowadays invention allows for an fantabulous print reproducibility, e.k. an exact transfer of the image to the printed medium. Bleeding is significantly reduced. The fountain solutions according to the present invention besides enable a smooth performance in offset printing, e.k. minimizing ink piling on the blanket and enabling a proper emulsification of the ink, preventing over-emulsification, which may upshot in unclear images or images having voids or too little water uptake (poor emulsification), which may upshot in poor ink transfer and ink piling on the blanket. The present fountain solutions enable high processing speeds during printing operations. They possess a low dynamic surface tension in order to enhance the desensitizing properties and a sufficiently loftier dynamic viscosity to permit an fifty-fifty distribution of fountain solution on the image plate. In addition, the fountain solution according to the present invention minimizes wash out effects and ink-haemorrhage. The fountain solutions co-ordinate to the present invention are compliant with current wellness and environmental regulations. Printed media obtained according to a printing process according to the nowadays invention have a loftier quality, even at high processing speeds.
The nowadays invention is exemplified past following examples:
Examples: Following fountains solutions were prepared by mixing the respective amounts of booze with water: a) 1 % by weight of tert.-amyl alcohol; 99% past weight of water.
b) 3% by weight of tert.-amyl alcohol; 97% by weight of h2o.
c) 5% past weight of tert.-amyl alcohol; 95% by weight of water.
d) i % by weight of tert.-butyl alcohol; 99% by weight of water (comparative example). due east) 3% by weight of tert.-butyl alcohol; 97% past weight of water (comparative example). f) 5% past weight of tert.-butyl alcohol; 95% past weight of water (comparative example). g) 1 % by weight of isopropyl alcohol; 99% by weight of h2o (comparative example). h) 3% past weight of isopropyl alcohol; 97% past weight of water (comparative example). i) 5% by weight of isopropyl alcohol; 95% by weight of water (comparative case).
The kinematic viscosity of the mixtures was determined at 20°C. The results are listed in Table 1 .
The static surface tension of the mixtures was determined according to the bubble pressure method with the automated dynamic surface tensiometer BP-D by Kyowa Interface Science Co.. The results are also listed in Table 1. Table i :
one> FSE = Dynamic Surface Tension of Water (72,8 dyne/cm) - (Dynamic Surface Tension / Dynamic Viscosity) Information technology is evident, that fountain solutions based on tert.-amyl alcohol and water accept a lower surface tension compared to fountain solutions based on other alcohols. However, the use of tert.-amyl alcohol in fountain solutions does non lead to an undesired reduction of fountain solution viscosity. Therefore the fountain solutions according to the present invention are able to combine a low surface tension without a sacrifice in viscosity. Also the FSE is higher for the fountain solutions of the nowadays invention compared to fountain solutions based on other alcohols at the same concentration. The FSE is a measure for the efficiency the fountain solution can be supplied from one curlicue to the other during the offset printing procedure.
Applications tests:
Following fountains solutions concentrates were prepared by mixing an amount of tert- amyl alcohol with the respective corporeality of a fountain solution base of operations mixtures compris- ing:
water: 19% by weight;
auxiliary wetting solvent: sixty%by weight;
desensitizing agent: 5% past weight;
pH-adjusting amanuensis: five% by weight;
chelating amanuensis: 1 % past weight;
surfactants: five% past weight;
other additives: five% past weight, based on the total weight of the fountain solution base mixture The respective fountain solutions were obtained by mixing the respective amount of fountains solution concentrate with the respective amount of water.
Fountain solution concentrate I :
a) tert.-amyl alcohol: 33.33% by weight;
b) fountain solution base of operations mixture: 66.67% past weight.
Fountain solution I:
a) fountain solution concentrate I: 3% by weight;
b) water: 97% past weight.
Fountain solution concentrate II:
a) tert.-amyl alcohol: xx% by weight;
b) fountain solution base mixture: lxxx% by weight. Fountain solution concentrate 2:
a) fountain solution concentrate Ii: ii.5% by weight;
b) water: 97.5% by weight.
Fountain solution concentrate III:
a) tert.-amyl alcohol: 32.3% by weight;
b) fountain solution base of operations mixture: 64.5% by weight;
c) N-octylpyrrolidone: three.ii% by weight.
Fountain solution Three:
a) fountain solution concentrate Three: three.i % by weight;
b) water: 96.9% past weight. Fountain solution concentrate IV:
a) tert.-amyl alcohol: fifty% by weight;
b) fountain solution base mixture: l% past weight. Fountain solution IV:
a) fountain solution concentrate IV: 2% past weight; b) water: 98% past weight.
Fountain solution concentrate 5:
a) tert.-amyl alcohol: 47.half-dozen% past weight;
b) fountain solution base mixture: 47.half-dozen% by weight; c) North-octylpyrrolidone: iv.viii% by weight.
Fountain solution Five:
a) fountain solution concentrate V: 2.ane % by weight; b) water: 97.9% by weight.
Fountain solution concentrate VI:
a) tert.-amyl alcohol: 47.six% by weight;
b) fountain solution base of operations mixture: 47.half-dozen% by weight; c) Surfynol® 440 (Air Products): 4.8% by weight.
Fountain solution VI:
a) fountain solution concentrate VI: ii.ane % by weight; c) water: 97.9% by weight.
Fountain solution concentrate Seven (comparative exampl a) fountain solution base mixture: 2% past weight. Fountain solution VII (comparative example):
a) fountain solution concentrate Vii: 2% by weight; b) water: 98% past weight.
Fountain solution concentrate VIII (comparative examp a) fountain solution base mixture: 40% past weight; b) isopropy alcohol: lx% past weight.
Fountain solution Viii (comparative example):
a) fountain solution concentrate VIII: two.1 % past weight; b) water: 97.9% by weight. Printing tests were carried out on a commercial press machine (Mitsubishi Lithopia Max BT-2 800). The printing speed was 800 rpm.
Paper of following form was used: Aurora® newspaper made past Nippon Paper Co..
Printing was carried out at ambient temperatures betwixt 20 to 25°C and a relative humidity of xl to 50%.
Post-obit ink was used: WD LEO-X by Toyo Ink MFG. CO., LTD.
The printing properties using the different fountain solutions were evaluated. The results are summarized in Table 2.
Table 2:
one) The minimum h2o source dial number refers to the setting of the fountain solution feed rate control of the printing car. The Mitsubishi printing auto used for the experiments has a punch range from 0 to 100. A pocket-size value for the water source punch number corresponds to a lower feed charge per unit of fountain solution. To obtain the value for lowest possible setting at which stains are not generated on the paper and printing operation is stable. Information technology is axiomatic that the equal or lower feed rates of fountain solutions could be applied to obtain better printing properties when fountain solutions of the present inventions were used.
¾ Emusifiability of the ink was controlled later on 10 000 sheets of newspaper were printed at the minimum water dial number. The emulsifiability was evaluated visually and as rated co-ordinate to following scale: A: good; B: somewhat bad; C: very bad.
Emulsification or mixing between ink and fountain solutions occurs due to shear forces during the transfer procedure. If the ink takes up too much water it becomes over- emulsified information technology leaves voids and unclear images on the substrate. If the ink does not mix with water and forms no stable emulsion the ink may mottle and the ink transfer to the paradigm plates will be poorer so that ink piling may occur where the ink hangs back on the plate and does non transfer onto the substrate. 3> The bleeding properties of the ink and the fountain solutions were evaluated visually and rated according to following scale: A: good; B: somewhat bad; C: very bad. Bleeding occurs when color pigments of the ink are eluted by the fountain solution. This effect results in a discoloration of the fountain solution and an accumulation of ink in the not-paradigm areas of the printing plates.
four> The impress reproducibility is a measure for the degree of quality of reproducing the image on the printing plate to the paper. Press reproducibility is evaluated by the comparing of the size of a halftone dot on the printing plate compared to the size of the halftone dot on the printed newspaper. The print reproducibility was rated according to post-obit calibration: A: good (no significant increase of the size of the halftone dot); B: somewhat bad (moderate increase of the size of the halftone dot); C: very bad (meaning increase in size of the halftone dot). 5> The blanket piling resistance is a measure for the amount of ink accumulated on the surface of the blanket used to transfer the image from the image plate to the paper. The coating piling resistance is good, if little or no ink has accumulated on the blanket and bad if a visually pregnant amount of ink has accumulated on the coating. The blanket piling resistance was rated according to post-obit scale: A: expert; B: somewhat bad; C: very bad.
Source: https://patents.google.com/patent/WO2012055870A1/en
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