CN102549085A

CN102549085A - Conductivity control of ink composition

Info

Publication number: CN102549085A
Application number: CN2010800377741A
Authority: CN
Inventors: 理查德·M·琼斯; 张月梅
Original assignee: Sun Chemical Corp
Current assignee: Sun Chemical Corp
Priority date: 2009-08-24
Filing date: 2010-08-24
Publication date: 2012-07-04
Also published as: IN2012DN01982A; AU2010286777A1; WO2011025773A1

Abstract

Systems and methods to control the printability of an ink comprising water are presented In exemplary embodiments of the present invention, monitoring the conductivity of the ink via a conductivity measurement device yields a signal which, for example, decreases strongly and linearly as water is removed from the ink In exemplary embodiments of the present invention a lower limit on this signal can be set to control the turning on of a pump, and/or the opening of a valve to allow flow of a makeup fluid into the ink In exemplary embodiments of the present invention the makeup fluid can, for example, be compnsed of water, a caustic substance, and an inhibitor Such a make-up fluid can restore the lost component(s) and correct for damage due to ink heating on press Similarly, in exemplary embodiments of the present invention, an upper limit on the conductivity signal can also be set to turn off the pump and/or close the valve, so as to prevent over-addition of the makeup fluid and avoid ink dilution and/or insoluble phase formation

Description

The specific conductivity control that printing ink is formed

The cross reference of related application

The application requires the right of priority in the U.S. Provisional Patent Application 61/236,206 of submission on August 24th, 2009, through reference its disclosure is incorporated herein hereby.

Technical field

The present invention relates to printing and correlation technique, particularly use the specific conductivity that records during printing operation, to control the method that printing ink is formed.

Background technology

Routinely, viscosity and the pH control printing ink formed are used in the water color ink dispersion liquid of offset printing and intaglio printing.The two all be used in the face of through evaporation when the printing ink loss printing ink that water produced changes, printing ink formed remain in the optimal scope of press quality.Yet, along with the passing of printing time in the printing ink of water dissolution in tackiness agent (such as for example at the UniQure of sun Chemical Corporation (Sun Chemical) ^TMIn the printing ink) follow the trail of two kinds of response functions and show that these are measured and change seldom in significant initial time section, their experience change suddenly with fast in the later time section.Therefore, use viscosity or pH to control the problem that this printing ink forms and be, although printing ink changes the printing defects that its composition and generation are followed during this initial time section, viscosity or pH measurement all can not be forecast these variations.Therefore, the system of measuring based on viscosity or pH lacks the particularity that in printing ink is formed, detects these important initial change, therefore can not in time remedy.

Similarly, viscosity controller also possibly lost in excessive control.For example, entrained air and foam possibly cause wrong HV reading, trigger the injection of fluid in the printing ink thus to attempt to keep viscosity.In this situation, printing ink can be by excess dilution, because the HV reading is to be caused rather than caused by the noticeable change of no air ink viscosity by the entrained air bubble.

Therefore, be the method that control printing ink is formed when printing that solves these problems of prior art what need in the art.

Summary of the invention

Proposed to be used to control the system and method for the printing of aqueous ink.In exemplary embodiment of the present invention, the specific conductivity of monitoring printing ink through conductivity measuring apparatus has produced for example along with water removing and the strong and linear signal that reduces from printing ink.In exemplary embodiment of the present invention, the lower limit that can set this signal is with starting of control pump and/or opening of valve, thereby makes the supply fluid to flow in the printing ink.In exemplary embodiment of the present invention, said supply fluid can comprise for example water, corrodent and suppressor factor.The damage that printing ink heating when this supply fluid can for example recover the component of losing and proofread and correct because of printing causes.Similarly, in exemplary embodiment of the present invention, the upper limit that also can set conductivity signal to be closing pump and/or shut-off valve, thereby prevents the excessive interpolation of supply fluidic and avoid the printing ink dilution and/or insolublely form mutually.In exemplary embodiment of the present invention; Can be for example be less than or equal to conductivity value half the with the lower limit set of conductivity signal, said conductivity value damages relevant with printing defects or permanent printing ink for given printing press, printing density and used pigment.In exemplary embodiment of the present invention; For example; For (i) every kind of ink colors, the (ii) volume in the storage tank, (iii) print speed, (iv) printing width and (v) one or more in the printed design can be confirmed the setting of aqueous liquid stream and on-off control bound respectively.

Description of drawings

Fig. 1 is at 100m/min, 35-40 ℃ and have no under the corrective action and (stress test: 3000gm printing ink under low printing ink volume conditions; 15 inches printing widths; The magenta and the blue-greenish colour UniQure of the exemplary of the printing ink circulation under 1.0 liters/minute), on Ko-Pack central authorities drum-type (CI) printing press, moving ^TMThe double exposure per-cent on yellow of printing ink is to the figure of working time;

Fig. 2 is under the stress test condition of Fig. 1, and the water weight percent of various ink colors is compared the figure (yellow=empty circles, magenta=gray circles, and blue-greenish colour=solid circles) of working time;

Fig. 3 is under the stress test condition of Fig. 1; Three kinds of printing ink (yellow=empty circles of Fig. 1; Magenta=gray circles, and blue-greenish colour=solid circles) viscosity to the figure of the working time of process (through printing ink being left standstill uninterruptedly clarified in 24 hours the viscosity that records after removing air);

Fig. 4 is under the stress test condition of Fig. 1, and the pH meter response of three kinds of printing ink (yellow=empty circles, magenta=gray circles, blue-greenish colour=solid circles) of Fig. 1 is to the figure of the working time of process;

Fig. 5 is the figure of the measurement specific conductivity of blue-greenish colour printing ink under the preparation of wide region and evaporation conditions;

Fig. 6 is to use three kinds of controlled variable, and under the stress test condition, the pH of exemplary magenta ink is to the figure of working time; And

Fig. 7 is for three kinds of controlled variable in Fig. 6, using, and the double exposure per-cent of magenta ink on Yellow ink is to the figure of working time.

Embodiment

Routinely, the water that uses simple specific conductivity to control in the printing ink adds, and both also is not suggested by practice.Be described below, this control is specially adapted to the wherein printing ink of water dissolution in tackiness agent.For for example at WetFlex ^TMThe UniQure of the sun Chemical Corporation that uses in the wet double exposure technology ^TMPrinting ink, situation are just so.

In exemplary embodiment of the present invention; Opposite with the pH that measures printing ink or viscosity and conventional system that its system and this variable are combined; Conductivity measurements accurately and is delicately followed printing ink and is formed the variation with working time; Thereby make to use the specific conductivity that records control the for example feeding rate of water, cause reducing or prevented by the caused printing defects of the evaporation of water from printing ink.

Printing press depends on printing ink or the technology weather resistance (robustness) to the variation (the for example variation of temperature, nip pressure or substrate) of printing condition to the acceptability major part of printing ink or technology, this in addition can for example find out in a printing period.At first, when printing operation begins, can obtain excellent result.Yet in 2-3 hour, the doctor groove possibly be full of agglomerative printing ink and possibly influence ink transfer negatively.This be because, in operation, printing ink is not carried out any adjustment, round-robin printing ink owing to evaporate concentrates.It has reached following state, and pigment and polymkeric substance cause gelling, has the unstable of some other variations of pH decline or dispersion agent character as basic reason.First sign of agglomerative is in can't seeing its doctor groove.It builds up, thereby causes flowing poorlyer in the storehouse, and causes bigger heating owing to printing ink can not be defined as to become popular.This alluvial makes printing stop the most at last, and first sign is to shift deficiency.

In exemplary embodiment of the present invention; If can avoid these variations through in whole printing operation, keeping initial printing ink to form; Ink performance when then having improved printing, and the market of this product and technology or similar products like and technology can significantly increase.

Like what mentioned, the specific conductivity control of the water color ink in not being described in intaglio plate and offset printing application in the art as yet.This possibly partly be since based on the printing ink of the aqueous solution such as for example UniQure ^TMPrinting ink rare.Based on the printing ink of the continuous dispersion liquid of solid water, before significant water evaporation, show the variation of specific conductivity hardly, even and such their specific conductivity also possibly increase.Yet, very responsive to the less water loss usually based on the measurement specific conductivity of the printing ink of the aqueous solution, because the water that is dissolved in the oligopolymer helps the ionic migration strongly.Therefore, although the concentration of dissolved ions increases, specific conductivity descends.Organic printing ink (for example based on the monomeric printing ink of radcure) is when the water dissolution conduction (and when such as through evaporating water being become more non-conductive when wherein removing) that becomes therein the time more.This conductivity variations is because ionic mobility increase when in organic phase, having water.Therefore, new control method of the present invention has utilized organic printing ink such as for example UniQure ^TMThis performance of type printing ink.

In exemplary embodiment of the present invention, through can adding aqueous fluids by the determined speed of the measurement of printing ink specific conductivity, can during the printing operation composition of printing ink remained under its original state or near.

In exemplary embodiment of the present invention, the printing ink that can use this control is preferably water and can be dissolved in the printing ink in the ink vehicle such as for example 5 weight % to 80 weight % with significance degree.

In exemplary embodiment of the present invention, for example, can set the tolerable limit of specific conductivity through inspection printing ink specific conductivity relevant in the printing ink that does not keep through the interpolation aqueous fluids with the generation of printing defects.In exemplary embodiment of the present invention; The storage tank or the conductivity measuring apparatus in the reflux pipeline that are arranged on printing ink can for example be exported signal; Said signal can be used for the pump and/or the valve of operating fluid injecting systems under the situation of amplifying or not amplifying, said fluid injection system is delivered to this fluid in storage tank or the printing ink suction line.In exemplary embodiment of the present invention, can use any device that produces with the proportional signal of printing ink specific conductivity.In exemplary embodiment of the present invention, transmitter can for example be transmitted and easily cleaned by printing ink or fluidic.In exemplary embodiment of the present invention, conducting probe can for example be preferably induction type.In exemplary embodiment of the present invention, injecting systems can be for example similar or identical with the injecting systems that is used for viscosity or pH control of commercial sale.

In exemplary embodiment of the present invention; When the specific conductivity of measuring drop to the specific conductivity (functions of printing press, printing density and used pigment etc.) relevant with printing defects or the infringement of permanent printing ink different, preferably be no more than the one of which half; Pump can for example be activated and/or valve can for example be opened; Thereby make the supply aqueous fluids can flow in the printing ink import of printing press, said supply water-based fluidic is formed and the composition of loss is complementary.Then, in case return to initial conductivity, then pump can for example cut out and/or valve can for example cut out.

In exemplary embodiment of the present invention, for fear of nonessential feedback, conductivity sensor can for example be arranged in before the valve of ink flow.Therefore, place the upper reaches of syringe to avoid lacking any influence of well blend conductivity sensor, said influence can cause unsettled ON/OFF signal is sent to pump or valve.

In exemplary embodiment of the present invention, as required, can the signal from the exemplary conducting probe be amplified.It should be noted that some printing ink have low water component, even make the noticeable change that a small amount of evaporation also can produce specific conductivity.Perhaps, have other printing ink of big water-content, when losing the water of same amount, can measure less conductivity variations although will have through evaporation.Therefore, in exemplary embodiment of the present invention, can perhaps more at large, according to circumstances the specific conductivity wave be calibrated for example to the printing ink of specific ink or particular type.

In exemplary embodiment of the present invention, preferred water-based supply solution can contain for example corrodent or the buffered soln of pH more than 10, and the dilute solution of solubility suppressor factor such as MEHQ for example.In this exemplary embodiment, general idea is the material that loses when replenishing ink printing, i.e. water, basicity and suppressor factor.Through the composition of maintenance ink vehicle like this, can avoid the loss of printing defects such as for example ink transfer.Notion of the present invention is compared with the known control of forming through the printing ink of pH and/or viscosity, and advantage is the commitment in printing, and when the variation of printing ink and printing was in fact taking place, a kind of printing ink in back was measured and do not shown any difference.

For example, in people's such as Laksin USP 6,772,683, evaporation and the ink viscosity subsequently according to fluid (being preferably water) after the printing in substrate increases the wet double exposure of having described water base UniQure type offset printing printing ink.Yet, if in press or evaporation of water earlier takes place in the printing ink recycle system, the possible loss double exposure that wets.The contrary double exposure that can not have ink transfer or previous color.This is depicted among Fig. 1; It has shown for two the continuous measuring points (station) on Ko-Pack CI printing press; Moving the double exposure loss of magenta (M) (empty circles) on yellow (Y) in 1 hour, and suitably printed (Yellow ink has more multimachine meeting drying before the coating blue-greenish colour under this latter event) by two kinds of color blue-greenish colours (C) (solid circles) and yellow (Y) continuation that two other measuring points separate.The reason of this behavior is the variation of the magenta ink rheology that causes of the loss owing to water, as shown in Figure 2, thereby causes from the ink transfer of the die mould roller that is used for magenta bad in this case.

In other cases, evaporation of water can cause for example higher printing density, contrary double exposure, printing ink impelling (ink slinging), static hair and fly China ink.

In exemplary embodiment of the present invention, can through to storage tank or in the printing ink pipeline controlled interpolation aqueous fluids come this premature evaporation of management of water from printing ink.Sometimes this fluid is sometimes referred to as in this article " supply fluid ".Like what mentioned, typically, viscosity or pH measurement are used for sending feedback signal to pump and/or valve, thereby control supply fluid adds speed.For UniQure ^TMFluid viscosity of printing ink (cone-plate formula) and pH, with this response record that records in Fig. 3 and 4.Show variation seldom in the time period that the M/Y double exposure density that two kinds of responses are seen reduces greatly in Fig. 1, exposed their vice propers thus as controlling mechanism.

On the contrary, as shown in Figure 5, the printing ink specific conductivity reduces very responsive to the water-content in about 30-20 weight % scope for example, and this printing defects (being that M/Y double exposure density reduces) takes place in said scope.In this example; Although be derived from the feedback of viscosity or pH do not require the printing preceding 1 to 2 hour in adjust; But be derived from the conductivity measurement signal to open the feedback of controlled water injection system; With the excessive water loss from circulation printing ink that prevents in preceding two hours that print at a gallop, to take place, as shown in Figure 2.

For the UniQure that in tackiness agent and pigment, comprises epoxy acrylate oligomer, water-dispersible polyurethane polymer, polyethyleneglycol diacrylate monomer, water, dispersing auxiliary, wetting agent and skimmer with level of signification (15-40% depends on color) ^TMPrinting ink, the concentration of water is typically 5 weight % to 40 weight % in the printing ink, and more preferably 10 weight % to 30 weight % most preferably are 20 weight % to 30 weight %.For the exemplary blue-greenish colour printing ink shown in Fig. 5, said printing ink contains has an appointment 28% water and shows the specific conductivity of about 270 little siemens/cm.Experience shows, is not lower than about 200 little siemens/cm (it is not reduced to corresponding to water and is lower than about 25 weight %) if the specific conductivity of this printing ink is not reduced to, and then obtains very acceptable printed matter.Yet when the water-content of this printing ink was lower than this level, observe the incident of following order along with further water evaporation: pH descended; Ink density increases in the solid area, the loss of the ink transfer of some form, double exposure loss; The loss of ink density in the solid area; The printing ink impelling is derived from the hair and the hangover of solid structure, and the assembly of unstable printing ink grumeleuse in the doctor groove.Any of these incidents all maybe be very unfavorable to press quality, and can for example further cause stopping work and/or postponing, and said shut-down and/or delay need or be removed it to defective printing ink place under repair from printing press.

Therefore; In exemplary embodiment of the present invention; For fear of the water loss that possibly cause printing defects or printing issues; For example preferably avoid developing into and be lower than 20% water, more preferably avoid developing into and be lower than 22% water, can for example the signal based on conductivity measurement be used for being activated to the water-based charging of printing ink.This can be through pouring water in the storage tank of stirring, perhaps through under the conductivity readings that for this instance is about 150 little siemens/cm or near the automatic injecting systems that is activated it and realizing simply.In general, the optimum water concentration of printing ink can be that printing ink and pigment are all specific.Therefore, it should be noted that existing water-content should not be reduced to is lower than some printing ink of 25%, therefore according to exemplary embodiment of the present invention, the water in those printing ink adds and can or be activated near it under the conductivity readings of for example about 220 little siemens/cm.

In exemplary embodiment of the present invention, surpass solubility limit (even partial) for fear of the excessive interpolation of water, for example can use the interpolation speed that is no more than the per hour about 120ml aqueous solution of per gallon circulation printing ink.It should be noted that adding the too high result of speed is the risk with the pigment cohesion of being separated.Curiously, this also is the result of the too many water of feasible evaporation, and unsettled pH descends but the latter also has the urethane of making and dispersible pigment dispersion incomprehensibly.In exemplary embodiment of the present invention, can the supply fluid be added rate setting for being substantially equal to vaporator rate.

In exemplary embodiment of the present invention; Except making water as the preferred aqueous fluids; Said aqueous fluids can also contain other materials alone or in combination, and said other materials is consumed when printing ink moves or will improves the overall printing ink performance on the contrary.For example, a kind of such material is to help pH is remained high corrodent.In general, printing ink solid dispersion stabilization depends on pH.Printing ink possibly flocculate being lower than under about 6 the pH, as in the laboratory, using droplet strong acid to confirm.The origin that pH descends possibly be the hydrolysis of propenoate, thereby causes forming acrylate, and said acrylate is buffered to pH and is lower than about 9.Curiously, high pH is a catalytic for this reaction, but acid (low) pH also is like this.Therefore, in exemplary embodiment of the present invention, can be preferably, degree of heat in the printing slows down hydrolysis through being minimized.In exemplary embodiment of the present invention, for example, this can utilize and add the low viscosity ink remain on under the suitable pH of dispersion stabilization through water-based supply fluid and come to realize best.

This exemplary corrodent in the supplementary feed solution can be for example strong inorganic base such as for example sodium hydroxide, or for example at least about pH 9, more preferably at least about the buffered soln of pH 10.When for example using specific radiation-hardenable printing ink; It also can be for example organic bases such as tertiary amine; But said material preferably is not secondary amine or primary amine or ammonia, because they possibly cause (in these radiation-hardenable printing ink) Michael reaction and printing ink gelling when printing press reclaims.In exemplary embodiment of the present invention, this corrodent preferably can be to be dissolved in the water at least about 1 weight %, even because under low-level water-based supply fluid added, it also should be effective.Yet according to base strength and/or surge capability, actual supply solution can only comprise for example about 0.1% this causticity material.For example, preferred solution is to use mineral alkali or damping fluid so that do not change the specific conductivity of organic phase.This is important, because expectation keeps the water-content of printing ink and the relation between its measurement specific conductivity.Add organic bases or damping fluid possibly for example raise printing ink specific conductivity and do not change water-content, so this possibly produce wrong wave.

The printing heating also causes suppressor factor loss and possible stability problem in the printing ink that reclaims.Demand to water-soluble inhibitor preferably waits to satisfy through the hydroquinone type material.In exemplary embodiment of the present invention, can use MEHQ.It has solvability in printing ink and alkaline water (pH＞8).Yet because it is to the strong influence of other standing storage suppressor factor, the level of MEHQ preferably should not be higher than about 0.5 weight % in printing ink.In addition, because the MEHQ negatively charged ion is the strong contributor of organic specific conductivity, to be lower than 1% be useful so for example in exemplary supplementary feed solution, its concentration remained.In the exemplary embodiment of the present invention of using MEHQ; Can estimate the wear rate of MEHQ from printing ink; And consider the estimation load cycle (for example semi-open, 1/3rd times opened etc.) of pump and/or valve, in supply solution, provide enough MEHQ to mate.

In exemplary embodiment of the present invention, conducting probe can be an any kind almost for example, and it comprises single two electrodes device, but more preferably can be the so-called sensing device of four electrodes for example.For example; Also can use several kinds of known dielectric monitors, for example such as the dielectric monitor of making or providing by a magnetoelectricity Subsidiary Company (B&C Electronics), Mei Teletuo benefit (Mettler Toldeo) and the Vinnie you (Vernier) of Italian Carnate.In exemplary embodiment of the present invention, probe can be for example self-cleaning.In addition, the placement of probe can be preferably in storage tank for example or in the printing ink reflux pipeline, wherein conductivity measurement will be derived from the printing ink of the well blend of returning from doctor groove (wherein take place significant shear and mix thus).Should note; It possibly be because the uniqueness of UniQure type structure has wherein been used the radiation curing oligopolymer with high water capacity property that these devices are not used to control the fact that printing ink forms (and make the surprised specific conductivity control of viscosity controller manufacturers be the fact of expectation) as yet; Yet the application's inventive method is not limited to UniQure type printing ink.

In exemplary embodiment of the present invention, injecting systems can be an any kind almost for example, and it comprises the injecting systems that is used for viscosity or pH control of commercial sale.Like what mentioned, in exemplary embodiment of the present invention, supply water-based fluidic injection point preferably in ink pumps suction line for example, thereby utilize any mixing in pump and the dual doctor groove.This placement has also avoided wherein too closely taking place owing to the position of detector and syringe the feedback loop of the too much on-off of syringe.In exemplary embodiment of the present invention, syringe can for example preferably drive by the conductivity signal of the printing ink that is derived from well blend or by its deutero-signal.

In exemplary embodiment of the present invention, for the volume in every kind of ink colors, the storage tank, print speed, printing width and even possibly also have printed design etc., can confirm the accurate setting of supply stream and on-off control bound respectively.Below embodiment shown that the typical case of the miniprinter that is suitable for utilizing the operation of relatively small amount printing ink is provided with.In exemplary embodiment of the present invention, actual quantity will change in other are used.The purpose of the following example only is to explain the validity of the method that is proposed, and can be changed or adjust the specific print request that in given application or situation, possibly be fit to satisfy.

Embodiment

Fig. 6 and 7 has described under 60m/min, uses Ko-Pack International CI narrow width press (six looks), ESI EZCure electrocuring and white polyethylene substrate, at exemplary UniQure ^TMThe instance that obtains in the actual print test of printing ink.Anilox roll is 1000 row, 1.6bcm, and printing plate is Esko CBU, and viscosity gum (back tape) is L5.4.Doctor is a steel.Printing press is tempering not.Continuous circulation through test printing ink is pressurized to printing ink on the printing press of no rolled paper of operation.Use 3000gm printing ink (except Yellow ink, it uses 10Kg), printing width is 15 inches, and the printing ink cycle rate is 1.0 liters/minute.After the operation of each hour, import rolled paper, obtain printed matter, remove rolled paper then and continue operating printing machine.Because a succession of factor, this method is damaged printing ink and printing apace, causes higher printing temperature and printing defects thus, and said factor comprises that for example water loss, suppressor factor loss and the pH of printing ink descend.Therefore we are called " stress test " with this test.

The instance printing ink that in Fig. 6 and 7, uses is the standard UniQure that processes with the pigment that is fit to ^TMPrinting ink.With big volume (4 gallons) operation, it before had been illustrated through increasing RCT the printing ink damage is minimized yellow in storage tank.Magenta is moved in 1 gallon container, and it is about half that is filled in printing ink pipeline and the doctor groove.Monitoring printing ink and sampling are checked in the laboratory being used in storage tank.Press quality is measured through the XRite photodensitometer.The water-based bulking liquor that uses is 0.1w/w%NaOH and 0.5w/w%MEHQ.Abbreviate this liquid as " corrodent " below.

Fig. 6 has shown and has been used for realizing various means that controlled corrodent the adds UniQure to the printing of measuring through pH meter ^TMThe influence of the pH of printing ink.Known when making the pH decline of this printing ink, printing ink possibly irreversibly damage because of the polyether polyols with reduced unsaturation deposition.In empty circles, the specific conductivity of use 220 ± 10 little siemens/cm is controlled 100 milliliters/hour/gallons the metering that opens and closes the water-based bulking liquor and is flowed.Under this control scheme.Printing ink pH (meter) is maintained at about in the stabilized zone of 6.7-7.2.Gray circles has shown the result of use pH (meter) as the feedback control signal that corrodent is added itself.PH (meter) at first must drop to and is lower than 6.5 and adds to trigger supply; As can see, because flow limitation, pH only slowly recovers.Solid circles has shown the result who uses viscosity controller.At this, after about 1 hour of operation,, viscosity just obtains wave when surpassing 0.5Pa.s.This delay mean can not addible supply volume/hour restriction in recover pH, and observe printing defects.

It should be noted that fluid flow restriction is crucial, is colour intensities because can add how many supply fluidic limiting factors.Color can not be diluted too many.Although can improve supply fluidic pH, can produce its impact ink or other problems such as corrosive and worry.The injection of any corrodent all wants spended time to obtain desired effects, because must it be blended in whole printing ink volumes and make it effective.Otherwise, owing to can detect the regional area of different pH and take responsiveness to proofread and correct, so the pH of printing ink is indefinite with heaving and dipping.Therefore, pH control is not effective fully.

Fig. 7 has shown the influence of different printing ink composition control methods to the double exposure of magenta on yellow.Empty circles is a data point of using specific conductivity control to produce under 220 ± 10 little siemens/cm using.As can in Fig. 7, see, this method has shown the excellence control of this print result.Gray circles has shown the result of the pH control of using corrodent stream as stated.Because 1/2 to 1 hour delay in the significant signal (the lower limit set point is 6.5) that obtains indication pH decline; Double exposure is degenerated in preceding two hours of operation; And when the past 5 hours after beginning supply fluid stream, just recover initial double exposure density, this is bad result.Similarly, solid circles is the data point that is derived from the viscosity control system that is used for present embodiment.In this case, postponed, and caused the remarkable reduction of double exposure magenta density in 1 hour that causes by the viscosity variation that does not record.In fact, as shown, this press quality observed value is never got back to desirable value, even after under 120 milliliters/hour/gallons, printing 5 hours with supply corrodent stream.

It should be noted that in this case even viscosity sensitivity increases and little variation is calibrated, said method still can be failed.Foam in the printing ink makes viscosity controller invalid.In addition, when also expectation replenishes the water of evaporation when avoiding retrogradation, the pH adjustment can not be fast.In make up water, can only contain a certain amount of corrodent, and not expect to make pH surpass 10.

Fig. 1 has shown to have no under the corrective action at 100m/min, 35-40 ℃ and under aforesaid low printing ink volume stress test condition, the UniQure that on Ko-Pack central authorities drum-type (CI) printing press, moves ^TMPrinting ink.In operation 1 hour, magenta (M) can not be transferred to yellow (Y) gradually and go up (empty circles) in double exposure, and blue-greenish colour (C) continues normal double exposure (solid circles) on yellow.

Fig. 2 shown with the passing of time, under the stress test condition in Fig. 1, and the water weight percent of measuring through the oven drying of institute's sample thief of weighing (yellow=empty circles, magenta=gray circles, blue-greenish colour=solid circles).Decline is linear and pump rate that only depend on all printing ink.

Fig. 3 shown under the stress test condition of Fig. 1, with the passage of working time, and the viscosity of three kinds of printing ink (yellow=empty circles, magenta=gray circles, blue-greenish colour=solid circles).In preceding approximately two hours of operation, do not detect viscosity and change.But after about 2 hours, can see that the linearity of viscosity increases.

Fig. 4 shown under the stress test condition of Fig. 1, with the passage of working time, and the pH of these printing ink (yellow=empty circles, magenta=gray circles, blue-greenish colour=solid circles).Said value is the pH meter reading and does not have correction to be real hydrogen ion activity.Magenta shows that with yellow early stage pH descends, though and blue-greenish colour postpones but still pH decline took place before 2 hour working time.

Fig. 5 has shown the measurement specific conductivity of blue-greenish colour printing ink under the preparation of wide region and evaporation conditions.Empty circles is the printing ink that in baking oven, is dried near 20% water.

Like what mentioned, Fig. 6 shown with damage under the stress test condition that is associated the pH of magenta ink response by the printing ink that disperses unstable to cause.Empty circles obtains down in the specific conductivity control (the present invention) of corrodent injection (0.1%NaOH), and is presented at 6 hours continuous in service significant pH variation does not take place.Gray circles has shown the result of the pH control of using the corrodent injection, itself since the signal delay of start injection almost caused on average lower pH in 1 hour.Grey black look circle has shown the result of the viscosity controller of using the corrodent injection, wherein before sending the viscosity signal to injecting systems, significant pH has taken place and has descended.

At last, like what mentioned, Fig. 7 has shown the double exposure of magenta on yellow under the stress test condition.Empty circles obtains down in the specific conductivity control (the present invention) of corrodent injection (0.1%NaOH), and it has produced stable double exposure.Gray circles has shown the result of the pH control of corrodent injection, and it has caused the loss that magenta shifts, and this delay in injection begins almost can not recover in back 5 hours.Grey black look circle has shown the result of the viscosity controller of using the corrodent injection, and it has caused the heavy losses of wet double exposure, and this did not recover in 5 hours.

Although it should be noted that the UniQure that has used sun Chemical Corporation ^TMPrinting ink is described the exemplary composition that is used for this process modification, but also can other printing ink be used for this method, and said other printing ink include but not limited to contain other printing ink of dissolved water.UniQure is disclosed in transferring the following patent of sun Chemical Corporation ^TMThe composition details of printing ink, through reference it is incorporated herein hereby: US 7479511, and EP 1504067, and EP 1792956, US 7226959 and EP 1392780.

The present invention to comprising its preferred embodiment is described.However, it should be understood that those skilled in the art after having considered present disclosure, can make amendment and/or improve, these modifications and/or improve within scope of the present invention and purport the present invention.

Claims (according to the modification of the 19th of treaty)

1. method that during printing operation, keeps printing ink to form, said method comprises:

In printing ink, add aqueous fluids,

Wherein said interpolation is to be undertaken by the determined speed of printing ink conductivity measurement.

2. the process of claim 1 wherein that said aqueous fluids is a water, and wherein said aqueous fluids is injected in the said printing ink with 50～150 milliliters/hour/gallons speed.

3. the process of claim 1 wherein that said aqueous fluids is a water, and wherein under the temperature between 25 ℃ to 35 ℃ said aqueous fluids is injected in the said printing ink.

4. the process of claim 1 wherein and use the interpolation of controlling said aqueous fluids based on the feedback loop of printing ink specific conductivity.

5. the process of claim 1 wherein that said aqueous fluids is a kind of in water, the alcohol or their combination.

6. the process of claim 1 wherein that said aqueous fluids is a kind of in water, the alcohol or their combination, and said printing ink contains, and to be designed to make fluid emulsification be the material of printing ink.

7. the method for claim 6, wherein said material is a tensio-active agent.

8. the process of claim 1 wherein that said printing ink comprises water.

9. the process of claim 1 wherein that said aqueous fluids is corrodent and the combination that cushions at least a and water in the solution.

10. each method in the claim 1～9 wherein is maintained under its original state or near it at said printing ink during the printing operation.

11. the method for claim 10 is used for preventing by (i) evaporation of water and (ii) variation at least a and the printing defects that causes of pH.

12. the method for claim 11, wherein said printing defects comprise at least a in the following situation: printing ink condenses, ink transfer reduces, the contrary double exposure of no ink transfer, the loss of wet double exposure, previous color, higher printing density, printing ink impelling, static hair, fly China ink and printing press damage.

13. each method in the claim 1～9, the specific conductivity of wherein said printing ink is responsive to the less water loss.

14. the process of claim 1 wherein that water can be dissolved in the ink vehicle in a large number.

15. the method for claim 14, the solubleness of wherein said water are 5 weight % to 80 weight %.

16. each method in the claim 1～9, wherein conductivity measuring apparatus places the storage tank or the reflux pipeline of printing ink.

17. the method for claim 16, wherein said conductivity measuring apparatus output and the proportional signal of said printing ink specific conductivity.

18. the method for claim 16 wherein can transmit and easily cleans said conductivity measuring apparatus through printing ink or fluidic.

19. the method for claim 16, wherein said conductivity measuring apparatus comprises conducting probe.

20. the method for claim 19, wherein said conducting probe are a kind of in simple two electrodes device and the four electrode sensing devices.

21. the method for claim 16, wherein said conductivity measuring apparatus output signal, said signal can be used for the pump and/or the valve of operating fluid injecting systems under the situation of amplifying or not amplifying.

22. each method in the claim 1～21 wherein is added into said aqueous fluids at least one in storage tank, printing ink suction line, printing ink reflux pipeline and the doctor groove.

23. each method in the claim 1～21 is not wherein being set the tolerable limit of said specific conductivity through adding the printing ink specific conductivity relevant with the generation of printing defects in the printing ink that aqueous fluids keeps through inspection.

24. each method in the claim 1～21 is wherein added said aqueous fluids through injecting systems such as commercially available those injecting systems that are used for viscosity or pH control.

25. each method in the claim 1～21, wherein when said specific conductivity was reduced to prescribed value, said pump was activated and/or said valve is opened, and made aqueous fluids flow in the printing ink.

26. the method for claim 25, wherein when returning to initial conductivity, said pump cuts out and/or said valve cuts out.

27. each method in the claim 21,25 and 26, wherein in ink flow, conductivity sensor is positioned at before the valve.

28. each method in the claim 25～27, wherein said prescribed value are less than or equal to the half the of said conductivity value, said conductivity value damages relevant with printing defects or permanent printing ink for given printing press, printing density and used pigment.

29. each method in the claim 1～9, the wherein said aqueous solution contains: (i) corrodent more than the pH10 or buffered soln and the (ii) dilute solution of solubility suppressor factor.

30. the method for claim 29, wherein said solubility suppressor factor is MEHQ.

31. each method in the claim 1～9 is wherein observed the difference of printing ink conductivity measurements in the commitment of printing.

32. a system that is used for during printing operation, keeping the printing ink composition, said system comprises:

Syringe;

Conducting probe; With

The unit that can be connected with the output of said conducting probe with passing on,

Wherein in operating process, said conducting probe is measured the specific conductivity of said printing ink, and said unit is made response and controlled the aqueous solution that in printing ink, adds to this.

33. the system of claim 32 also comprises pump and/or valve.

34. the system of claim 33, wherein when the measurement specific conductivity of said printing ink was reduced to prescribed value, said pump was activated and/or said valve is opened, and made aqueous fluids flow in the printing ink.

35. the system of claim 32, wherein said conducting probe is a kind of in simple two electrodes device and the four electrode sensing devices.

36. the system of claim 32, wherein said conducting probe output signal, said signal can be used for the pump and/or the valve of operating fluid injecting systems under the situation of amplifying or not amplifying.

37. the system of claim 32, wherein when said specific conductivity was reduced to prescribed value, said pump was activated and/or said valve is opened, and made aqueous fluids flow.

38. the system of claim 37, wherein when returning to the initial conductivity of said printing ink, said pump cuts out and/or said valve cuts out.

39. the system of claim 32, wherein said aqueous fluids is that (i) is added into the aqueous fluids of storage tank or (ii) is added at least a in the aqueous fluids of printing ink suction line.

40. the system of claim 32 is wherein for (i) every kind of ink colors, the (ii) volume in the storage tank, (iii) print speed, (iv) printing width and (v) at least a in the printed design confirmed the setting of aqueous liquid stream and on-off control bound respectively.

41. the system of claim 37, wherein said prescribed value is less than or equal to the half the of said conductivity value, and said conductivity value damages relevant with printing defects or permanent printing ink for given printing press, printing density and used pigment.

42. the system of the composition of the printing ink that a different measuring points place that is used for during printing operation keeping printing press uses, said system comprises at each measuring point place of said printing press:

Syringe;

Conducting probe; With

Wherein in operating process, the conducting probe at each measuring point place is measured the specific conductivity of printing ink, and said unit is made response and controlled the aqueous solution that in the printing ink at this measuring point place, adds to this.

43. the system of claim 42; Wherein each unit comprises one or more central controllers; Said one or more central controller can be connected with the output of the said conducting probe at each measuring point place with passing on, and the aqueous solution that in the printing ink at this measuring point place, adds of Long-distance Control.

44. the system of claim 42, wherein each unit is carried out performance and the optimised control algolithm of the said printing ink that uses for its specific measuring point place.

45. the system of claim 43, wherein said one or more central controllers are carried out the optimised control algolithm for the performance of the printing ink of each given measuring point place use of said printing press.

46. each system in the claim 42～45, the said aqueous solution at wherein given measuring point place is a kind of or its combination in water, the alcohol.

47. each system in the claim 42～45, the said aqueous solution at wherein given measuring point place is corrodent and the combination that cushions at least a and water in the solution.

48. each system in the claim 42～45, the said aqueous solution at wherein given measuring point place contains the above corrodent of (i) pH10 or buffered soln and the (ii) dilute solution of solubility suppressor factor.

49. the system of the composition of the printing ink that a different measuring points place that is used for during printing operation keeping printing press uses, said system comprises at each measuring point place of said printing press:

Each system in the claim 32～41,

Wherein separately the system that uses of measuring point place can but needn't be identical.

50. the system of claim 49; Wherein the unit separately of each system at each measuring point place comprises one or more central controllers; Said one or more central controller can be connected with the output of the said conducting probe at each measuring point place with passing on, and the aqueous solution that in the printing ink at this measuring point place, adds of Long-distance Control.

51. the system of claim 49, each unit of wherein said different system is carried out the optimised control algolithm for the performance of the printing ink of its specific measuring point place use.

52. the system of claim 50, wherein for each measuring point, said one or more central controllers are carried out the optimised control algolithm for the performance of the printing ink of the said measuring point place use of said printing press.

53. the system of claim 49, the aqueous solution that wherein uses at each measuring point place of said printing press can but needn't be identical with the aqueous solution that any other measuring point place uses, and the performance of the printing ink that uses for said specific measuring point place and optimised.

54. each system in the claim 46～48; The aqueous solution that each measuring point place of wherein said printing press uses can but needn't be identical with the aqueous solution that any other measuring point place uses, and the performance of the printing ink that uses for said specific measuring point place and optimised.

Claims

In printing ink, add aqueous fluids,

7. the method for claim 6, wherein said material is a tensio-active agent.

8. the process of claim 1 wherein that said printing ink comprises water.

11. each method in the claim 1～10 is used for preventing by (i) evaporation of water and (ii) variation at least a and the printing defects that causes of pH.

13. each method in the claim 1～12, the specific conductivity of wherein said printing ink is responsive to the less water loss.

16. each method in the claim 1～15, wherein conductivity measuring apparatus places the storage tank or the reflux pipeline of printing ink.

23. each method in the claim 1～22 is not wherein being set the tolerable limit of said specific conductivity through adding the printing ink specific conductivity relevant with the generation of printing defects in the printing ink that aqueous fluids keeps through inspection.

24. each method in the claim 1～22 is wherein added said aqueous fluids through injecting systems such as commercially available those injecting systems that are used for viscosity or pH control.

25. each method in the claim 21, wherein when said specific conductivity was reduced to prescribed value, said pump was activated and/or said valve is opened, and made aqueous fluids flow in the printing ink.

29. each method in the claim 1～28, the wherein said aqueous solution contains: (i) corrodent more than the pH10 or buffered soln and the (ii) dilute solution of solubility suppressor factor.

30. the method for claim 29, wherein said solubility suppressor factor is MEHQ.

31. each method in the claim 1～30 is wherein observed the difference of printing ink conductivity measurements in the commitment of printing.

Syringe;

Conducting probe; With

33. the system of claim 32 also comprises pump and/or valve.