DK153797B - Cleaning fluid containing γ-butyrolactone and/or N- methyl-2-pyrrolidone for the removal of printing ink and silk screen printing colours - Google Patents

Description

DK 153797B

The present invention relates to a cleaning fluid of the kind set forth in the preamble of claim 1 for the removal of printing and screen printing inks, in particular for cleaning screen frames.

The liquid according to the invention, which is suitable for solving all kinds of cleaning problems in the printing and screen printing industry without the use of dangerous substances, is characterized in that it consists of a substantially anhydrous mixture comprising (a) Y-butyrolactone of the formula And CH or H 2 C C = O / O 10 and / or N-methyl-2-pyrrolidone of formula H 2 C-CH 2 | = O

N

CH, in an amount of 1 - 25 ° ό, preferably about 10 µ (v / v) and (b) one or more propylene glycol derivatives selected from substituted propyl acetates of the general formula ch wherein R is hydrogen or alkyl of 1-6 carbon atoms, and / or propylene glycol ethers of the general formula

DK 153797B

2 CH 3 R, -O- (CH 2 -CH-O) -H, in L n wherein R 1 is alkyl of 1-6 carbon atoms and n is 1, 2 or 3, and optionally 5 (c) a diluent consisting of one or more aliphatic hydrocarbons having a flash point greater than 22 ° C and / or an ether selected from butyldiglycol ether, ethyl diglycol ether and methyldiglycol ether (d) a surfactant wherein the amount of components (c) and (d) is maximum 5Q% (v / v) of the liquid.

Dilution as well as universal cleaning or washing away of printing and / or screen printing inks from stencils, printing plates, screen frames, rollers and the like have so far been carried out by cleaning liquids containing either "dangerous substances", cf. Environmental Protection Agency Order No. 147 of March 16, 1981, or aromatic solvents, the use of which involves significant risks to persons working 20 with the funds. Especially for the purification of old dried color residues in offset and letter printing, hitherto xylene- or toluene-based agents, whose health effects are well known, have so far been preferably used. In addition, the known cleaning fluids often exhibit very low flame points, which partly means that the liquids are easily flammable and partly have a high volatility and thus increase the potential health risk through inhalation of vapors. Thus, toluene has a flash point 30 of only 5 ° C.

The currently leading cleaning liquid for washing screen frames is thus "Pregan 240E" from Kissel &

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3

Wolf, West Germany, which has the following composition:

Ethyl acetate 10%

Isobutyl acetate 32% "Solvesso® 100" 58% 5 and a flash point of 31 ° C.

"Solvesso® 100" from Esso Chemicals contains 99% aromatics.

It has long been recognized that the colorant thinner liquids recommended by the dye manufacturers 10 are based on solvents containing dangerous substances and therefore require the utmost care.

Within the purification process, the task is even more difficult. Here, it is often a matter of dissolving dried colors in order to remove them from the printing and serial printing apparatus. Some colors are easy to clean, while others are extremely difficult to deal with, and the color types used are different for each graphic company. Certain dyes are particularly malignant because they consist of two-component systems. Such dyes can be difficult to remove during a normal working day unless cleaning fluids of a type that involve health risks are used.

As a result, hitherto, it has been necessary to maintain the aforementioned health-hazardous and easily flammable cleaning fluids, since only such fluids have been found to dissolve all current color types.

Special problems are encountered in the silk screen industry

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more, because the cleaning fluids capable of removing all the dyes will also tend to destroy the glue used in mounting tissues on screen frames. At the same time, 5 water-based or highly hydrophilic cleaning fluids cannot be selected simply because such fluids will tend to destroy the stencil emulsion.

The use of γ-butyrolactone and / or N-methyl-2-pyrrolidone as a color cleaner is known per se.

Thus, such an application is described in FR Patent No. 2,354,377, however, which is concerned with removing the stencil itself and not the ink. An important feature of a cleaning agent for removing screen printing colors is that it must not remove or destroy the stencil.

The cleaning agent according to the aforementioned FR patent, inter alia, contains periodicities which will destroy polyvinyl alcohol-based stencils. In addition, the agent may contain large amounts of water which will also damage the stencil used.

A cleaning liquid consisting of 50-95% by weight of N-methyl-2-pyrrolidone and 5-50% by weight of a water-miscible alkanolamine is disclosed in EP Patent No. 21,149. however, is primarily aimed at dissolving solder flux residues and various cured coatings of 25 synthetic organic polymers, as well as it can utilize *.

It is desirable to dissolve epoxy varnishes, which it is intended to avoid with the cleaning liquid according to the invention, because the adhesive used for mounting silk-screen frames is made on this basis.

DE Publication No. 3 401 982 discloses water-based inks of pH 9 - 11, which inks may contain solvents such as N-methyl-2-pyrrolidone, to increase the solubility of the dye in

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5 formulations. However, the cleaning fluids comprising the invention are not water-based, but essentially water-free, since water, in greater quantities, will degrade the stencils used in practice.

A lacquer remover based on β-butyrolactone is known from US

Patent No. 2,438,038. However, this varnish remover is also water-based and contains from 40 to 80% of β-butyrolactone or β-valerolactone, whereas the liquid of the invention does not contain substantial amounts of water and may contain a maximum of 25% of lactone as it will otherwise break down the glue. In other words, the cleaning fluid known from the aforementioned US patent cannot be used for cleaning silk screen frames while preserving both the glue and the stencil.

13 EP Publication No. 81,355 discloses a method and a means for cleaning tissues for printing. The composition according to the specification contains N-methyl-2-pyrrolidone in amounts of 30 - 85%, which will cause degradation of the polyurethane- and epoxy-based 20 adhesive types used in the silk-screen printing fabric. In addition, the agent of the aforementioned EP disclosure may contain cyclohexanone or halogenated compounds which are referred to as dangerous substances and which are not included in the liquid according to the invention.

As mentioned above, it is an object of the invention to provide a cleaning fluid for removing printing and screen printing inks which are partly effective against all common color types and partly less harmful to the cleaning fluids used so far. In particular, the latter characteristic has been given high priority as a result of the rising environmental awareness, which increasingly focuses on occupational health and safety problems. An alarming increase in the incidence of brain damage in humans

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Of course, 6 people who have been working with organic solvents for a long time have sharpened the need to find less toxic cleaning fluids for the printing and silk-screen industry.

5 The Vapor Hazard Ratio (VHR) can be used as a measure of the potential danger of a compound. The definition is VHR = £ where C is the equilibrium concentration at the prevailing temperature and GV is the limit value of the compound, see Danish

Chemistry 5, 1986, pages 146-153.

In the following Table 1, relevant chemical compounds are listed according to the increasing hazard assessed by the VHR method. A number of these compounds are used in the Examples of the above-mentioned EP Publication no.

81,355. The data set out in Table 1 show that the compounds used in said EP publication disclosure cannot be construed as being in accordance with current health and safety regulations under normal conditions of use.

In other words, the liquid mixtures used according to EP Publication No. 81,355 cannot avoid being labeled Xn and thus designated as harmful according to the Environmental Protection Agency's list of dangerous 25 substances.

In the following Table 1, "Vapor Hazard Ratio" is calculated as P · 106 Po

VHR = HGV 760 = 13 ”M

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7 where P0 is the vapor pressure in mmHg at 25 ° C and HGV is the hygienic limit value in ppm.

There are no established hygienic limit values for propylene carbonate, diethylene glycol monobutyl ether and dimethylsulfoxide. Therefore, these compounds are assumed to have HGV values of 100 ppm.

The cleaning fluids of the invention contain no constituents further down the table than propylene glycol monorethyl ether.

TABLE 1 10 VHR values_for some liquids; _ Liquid_ HGV__P0__VHR Comments

Propylene carbonate 100 * 0.03 0.4 **

Solvesso® 200 100 0.1 1.3 ** X.

'I

Diethylene glycol monobutyl ether (DB) 100 * 0.1 1.3 ** EXSOL® D 80 100 0.3 3.9 **

Dipropylene glycol monomethyl ether (DPM) 100 0.4 5.3 ** N-methyl-2-pyrrolidone (NM2P) 100 0.5 6.6 X.

in

Dimethylsulfoxide lnn * "Λ (DMSO) 100 ° 6 7'9 Δ 2 -butyrolactone (BL0) 75 0.9 15.8 **

Propylene glycol monomethyl ether acetate (PMA) 100 2.4 32 **

Ethylene glycol monobutyl ether 0.6 0.6 X Δ (ro n

Solvesso'17 100 50 2.8 74 ** X

EXSOL® D 30 100 6 79 ** ° 30 Propylene glycol monomethyl ether (PM) 100 10.3 146 **

Isobutyl acetate 150 175

Cyclohexanone 3.4 179 Xn (odor genes)

Xylene 50 8 210 X

n 8

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in '* · 1 * «* · TABLE 1 (continued) TABLE 1 (continued) VHR values for some liquids; _ Liquid_ HGV _P0__VHR Comments

Ethyl acetate 300 94 412

Ethylene glycol monoethyl ether acetate 5 1.7 448 Xn

Trichlorotrifluoroethane 500 330 868 **

1,1,1-Trichloroethane 100 130 1711 X

n

Dichloromethane 50 428 11260 X

n

Chloroform 2 205 134890 XR

* set at 100 ppm as explained above ** not listed in the Environmental Protection Agency's list of hazardous substances X: Irritant for 15 Xp: Harmful Δ: not included in the applicant's cleaning fluids.

As can be seen from the above as well as the following Examples 7 and 8, the cleaning fluids of the invention are less toxic and less degrading on the adhesive systems used in the series than the cleaning fluids known from EP Publication No. 81355.

As will be seen from Examples 7 and 8, adhesive systems based on two-component epoxy or polyurethane will be degraded and rendered unusable if the serigraphic frames of color purification are exposed to cleaning fluids whose receptors contain more than 25¾ N- methyl-2-pyrrolidone.

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The ability of a solvent to dissolve a given substance, e.g. a polymer can conveniently be evaluated by parameter considerations according to the so-called "Hansen system" described in Encyclopedia of Chemical Technology, Suppl. vol. 2nd. Ed., Pp. 889-910, John Wiley & Sons,

New York, and by Charles M. Hansen in Sheep Och Lack 17, 69-77 (1971). According to the "Hansen system", a solvent can be described by three solubility parameters / p (the dispersion parameter), Jp (the polarity parameter h) and 10 (the hydrogen bonding parameter), whose squares together are the total cohesive energy square: ^ tot + * P + ^ H '

Two substances have maximum interaction (ie are soluble in each other) when their solubility parameters are in pairs as close to each other as possible. Thus, a solvent can be characterized by a total parameter which can be divided into three subparameters. can be illustrated in a three-dimensional coordinate system with the sub-parameters as axes.

The solubility of polymers, e.g. those used as a binder in printing ink can then be characterized on the basis of their interactions with various solvents, since it has been found that all solvents capable of dissolving a particular binder fall within a defined volume in the above coordinate system . If the scale of the ^ p axis is expanded by a factor of 2, the solubility range becomes a sphere.

Thus, a polymer can be characterized by a center and a radius Rp.

Any solvent can, based on its three parameters, be fitted into the three-dimensional coordinate system for a given polymer. In solubility experiments, it is determined subjectively whether the individual

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The solvent may or may not dissolve the polymer, and then an IT determination of the solubility range of the polymer is made, the program iteratively determining a center and a radius such that the greatest possible number of active solvents lie within the resulting sphere while not - effective funds fall outside.

The following Examples 1 and 2 describe how, using the "Hansen system", possible solvents were found for two common vinyl binder printing inks, "Thermojet White" and "Drugloss Blue", considered to be some of the the most difficult colors to remove from printing equipment. Examples 3-6 describe similar calculations for an additional four common print colors that are difficult to remove.

However, a methodical review of the screen printing and printing inks for the development of new cleaning and dilution fluids found that Hansen's parameter theory, even at equal weight without regard to the time parameter, leads to clear answers . This can be explained, inter alia, by the fact that the colors can be complicated and contain several polymers and that the parameter model is complicated by the use of mixtures of solvents. In addition, in 25 practices, the above-mentioned "time parameter" has to be taken into account, since a solvent is not practically useful if it is only effective after prolonged exposure, even if it satisfies the Hansen model.

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Therefore, in order to obtain results that are useful in practice, one must use a modified Hansen model to find a solvent that can itself dissolve the colors in question, but which - to achieve a reasonably high dissolution rate and adapt low costs - are part of a mix with one or more other means.

As mentioned, N-methyl-2-pyrrolidone and γ-butyrolactone are solvents which, each or in combination, have been shown to be capable of dissolving many, but not all, common printing and screen printing colors. Thus, for example, γ-butyrolactone cannot dissolve Colorjet C0113 mandarin orange from Sericol (see Example 3), and N-methyl 1-2-pyrrolidone cannot dissolve Seristar® SX (see Example 15), which are inks based on vinyl binders. Therefore, it has been found necessary to add one or more substituted propyl acetates and / or propylene glycol ethers, thereby obtaining (a) solubility, (b) higher dissolution rates (i.e., improved 20 time parameters) in several cases, and (c) economically more beneficial cleaning fluids.

γ-Butyrolactone and / or N-methyl-2-pyrrolidone (a) must be mixed with such substituted propyl acetates and / or propylene glycol ethers (b) within certain limits as determined by such conditions as solubility, dissolution rate ("time parameter") and economy. Applicable compositions are obtained, also economically, when the mixing ratio between (a) and (b) is between 25:75 and 1:99 (v / v).

As component (b), the present cleaning liquid may contain the substituted propyl acetates and / or one or more propylene glycol ethers selected from propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene ether.

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12 glycol monomethyl ether and tripropylene glycol monomethyl ether. The diluent (c) is an ether selected from butyldiglycol ether, ethyl diglycol ether and methyldiglycol ether and / or one or more aliphatic hydrocarbons having a flash point above 22 ° C.

The flash point of the aliphatic hydrocarbon must not be below 22 ° C. Preferably, the flame retardant should be above 55 ° C.

Furthermore, the present liquid may contain a surfactant (d), in particular a nonionic surfactant, preferably in the form of a nonylphenol ethoxylate.

As mentioned, the liquids in question can be used for all types of cleaning jobs in the field of screen printing and printing. In the field of silk-screen printing, the fluids are particularly useful for cleaning frames, but also during the printing process itself. In offset printing, the fluids can be used to clean old dried color residues and to clean machine parts, rollers, cliches, etc.

Component (a), as mentioned, represents a maximum of 25¾ of the mixture.

Components (c) and (d) together make up to a maximum of 50¾ of the mixture. Incidentally, the mixture can be composed within fairly wide limits, taking into account the specific field of application.

The invention is further illustrated by the following examples. Examples 1-6 illustrate the application of the Hansen parameter theory to conventional inks, while Examples 7 and 8 illustrate the invention.

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EXAMPLE 1 In this example, possible solvents are selected for the "Thermojet White" inks based on solubility tests and Hansen parameters. A subjective assessment is made of the ability of the selected solvents to dissolve the color, the solubility tests being carried out in test tubes where the ink is in contact with an excess of the liquids in question. The assessment is done after 10 minutes and after 24 hours.

10 The results obtained are shown in the following Table 2, which shows, among other things, that some of the solvents require long-term exposure before they are effective.

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14 TABLE 2

Solubility range for "Thermojet White" <TD 3 18.77 / p = 11.55 / = 7.81 Rp = 9.76

Solubility

Solvent tf <f 10 min. 24 hrs.

Acetone 15.50 10.40 7.00 yes

Acetophenone 19.60 8.60 3.70 no * 3 yes 1.3-butanediol 16.60 10.00 21.50 no no

Butyl acetate 15.80 3.70 6.30 no yes-butyrolactone 19.00 16.60 7.40 yes

Carbon tetrachloride 17.80 0.00 0.60 no no

Chlorobenzene 19.00 4.30 2.00 yes

Chloroform 17.80 3.10 5.70 yes

Cyclohexanol 17.40 4.10 13.50 no no * 3

Diacetone alcohol 15.80 8.20 10.80 no * 3 yes o-dichlorobenzene 19.20 6.30 3.30 no * 3 yes

Diethylene glycol 16.20 14.70 20.50 no yes

Diethyl ether 14.50 2.90 5.10 no no

Dimethylformamide 17.40 13.70 11.30 yes

Dimethylsulfoxide 18.40 16.40 10.20 no yes 1.4-dioxane 19.00 1.80 7.40 no yes

Dipropylene glycol 15.90 20.20 18.40 no no

Ethanol 15.80 8.80 19.40 no no

Ethyl acetate 15.80 5.30 7.20 yes

Ethylene dichloride 19.00 7.40 4.10 yes

Ethylene glycol 17.00 11.00 26.00 no no

Ethylene glycol monoethyl ether acetate 15.90 4.70 10.60 no yes

Hexane 14.90 0.00 0.00 no no

Isophorone 16.90 8.20 7.40 no * 3 yes

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Solubility

Solvent J ^ <fp 10 min. 24 hrs.

Methanol 15.10 12.30 22.30 no no

Methylene chloride 18.20 6.30 6.10 yes

Methyl isobutyl ketone 15.30 6.10 4.10 no yes N-methyl-2-pyrrolidone 18.00 12.30 7.20 yes

Nitrobenzene 20.00 8.60 4.10 no yes 2-nitropropane 16.20 12.10 4.10 no yes

Propylene carbonate 20.00 18.00 4.10 * yes

Propylene glycol 16.80 9.40 23.30 no no

Tetrahydrofuran 16.80 5.70 8.00 yes

Toluene 18.00 1.40 2.00 no no

Trichlorethylene 18.00 3.10 5.30 yes *) Not rated after 10 min.

a) Should have been inside the calculated ball b) Should have been outside the calculated ball EXAMPLE 2 Similar to Example 1, possible solvents for the "Drugloss Blue" inks are selected based on solubility experiments and Hansen parameters.

5 The results obtained are shown in Table 3: TABLE 3 16

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Solubility range for "Drugloss Blue" JD = 17.54 <f? = 8.35 / H = 7.33 Rp = 5.90

Solubility

Solvent «/ ^ 10 min. 24 hrs.

Acetone 15.50 10.40 7.00 yes

Acetophenone 19.60 8.60 3.70 yes 1.3-butanediol 16.60 10.00 21.50 no no 1-butanol 16.00 5.70 15.80 no no

Butyl acetate 15.80 3.70 6.30 jaa ^ -Butyrolactone 19.00 16.60 7.40 jaa

Carbon tetrachloride 17.80 0.00 0.60 no no

Chlorobenzene 19.00 4.30 2.00 yes

Cyclohexanol 17.40 4.10 13.50 no no

Diacetone Alcohol 15.80 8.20 10.80 No * 3 Yes 0-Dichlorobenzene 19.20 6.30 3.30 No * 3 Yes

Diethylene glycol 16.20 14.70 20.50 no no

Diethyl ether 14.50 2.90 5.10 no no

Dimethylsulfoxide 18.40 16.40 10.20 no yes 1.4-dioxane 19.00 1.80 7.40 no yes8

Dipropylene glycol 15.90 20.20 18.40 no no

Ethanol 15.80 8.80 19.40 no no

Ethyl acetate 15.80 5.30 7.20 yes

Ethylene dichloride 19.00 7.40 4.10 yes

Ethylene glycol 17.00 11.00 26.00 no no

Ethylene glycol monoethyl ether acetate 15.90 4.70 10.60 yes

Hexane 14.90 0.00 0.00 no no

Isophorone 16.90 8.20 7.40 no * 3 yes

Methanol 15.10 12.30 22.30 no no N-methyl-2-pyrrolidone 18.00 12.30 7.20 yes

Nitrobenzene 20.00 8.60 4.10 no yes 2- nitropropane 16.20 12.10 4.10 no yes

Propylene glycol 16.80 9.40 23.30 no no

Toluene 18.00 1.40 2.00 no yes

Trichlorethylene_18.00 3.10 5.30_, 1a_- a) Should have been inside the calculated sphere l_ \ Π _ I l_ 1 * _ ___L. __I _ Pn n / J <-> λ Is 1 l n I r \ EXAMPLE 3 17

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Similar to Example 1, possible solvents are selected for the "Color Jet" inks on the basis of solubility tests and Hansen parameters.

5 The results obtained are shown in Table 4; TABLE 4

Color Jet Solubility Range (CO-113) <fD = 14.34 / p = 7.45 <fH = 10.12 Rp = 12.75

Solubility

Solvent «fp ^ 10 min. 24 hrs.

Acetone 15.50 10.40 7.00 yes

Acetophenone 19.60 8.60 3.70 yes 1.3-butanediol 16.60 10.00 21.50 no * 3 no * 3 1-butanol 16.00 5.70 15.80 yes

Butyl Acetate 15.80 3.70 6.30 Yes ^ -Butyrolactone 19.00 16.60 7.40 No No

Carbon tetrachloride 17.80 0.00 0.60 yes

Chlorobenzene 19.00 4.30 2.00 yes

Chloroform 17.80 3.10 5.70 yes

Cyclohexanol 17.40 4.10 13.50 no * 3 no * 3

Diacetone Alcohol 15.80 8.20 10.80 Yes O-Dichlorobenzene 19.20 6.30 3.30 Yes Diethylene Glycol 16.20 14.70 20.50 Yes3 Diethylene Glycol Monobutyl Ether 16.00 7.00 10.60 Yes Diethyl Ether 14 50 2.90 5.10 yes dimethylformamide 17.40 13.70 11.30 yes dimethyl phthalate 18.60 10.80 4.90 yes dimethyl sulfoxide 18.40 16.40 10.20 no * 3 no * 3 1.4-dioxane 19.00 1.80 7.40 yes 18

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Solubility

Solvent ^ 10 min. 24 hrs.

dipropylene glycol 15.90 20.20 18.40 no no dipropylene glycol methyl ether 15.50 5.70 11.20 yes

Ethanol 15.80 8.80 19.40 yes

Ethyl acetate 15.80 5.30 7.20 yes

Ethylene dichloride 19.00 7.40 4.10 yes

Ethylene glycol monoethyl ether acetate 15.90 4.70 10.60 yes

in L

Hexane 14.90 0.00 0.00 noD no

Isophorone 16.90 8.20 7.40 yes

Methanol 15.10 12.30 22.30 yes

Methylene chloride 18.20 6.30 6.10 yes N-methyl-2-pyrrolidone 18.00 12.30 7.20 yes

Nitrobenzene 20.00 8.60 4.10 yes 2-nitropropane 16.20 12.10 4.10 yes

Propylene carbonate 20.00 18.00 4.10 no no

Propylene glycol mono-. methyl ether 15.60 6.30 11.60 yes

Tetrahydrofuran 16.80 5.70 8.00 yes

Toluene 18.00 1.40 2.00 yes

Trichlorethylene 18.00 3.10 5.30 yes a) Should have been inside the calculated ball b) Should have been outside the calculated ball EXAMPLE 4 In a similar way to Example 1, possible solvents for the vinyl binder based pressure / d are selected. \ color "Seristar ^ SX" based on solubility tests and Hansen parameters.

5 The results obtained are shown in Table 5: TABLE 5 19

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Solubility range for Sericol red Seristar D2528 (Seristar® SX) -iD = 16.25 ^ p = 14.43 ^ = 10.29 Rp = 11.06

Solubility

Solvent ^ 10 min. 24 hrs.

Acetone 15.50 10.40 7.00 yes

Acetophenone 19.60 8.60 3.70 yes 1.3-butanediol 16.60 10.0021.50 no no 1-butanol 16.00 5.7015.80 no * 3 no

Butyl acetate 15.80 3.70 6.30 ya ya-butyr olactone 19.00 16.60 7.40 yes

Carbon tetrachloride 17.80 0.00 0.60 no no

Chlorobenzene 19.00 4.30 2.00 no no

Chloroform 17.80 3.10 5.70 no no

Cyclohexanol 17.40 4.10 13.50 no no

Di acetone alcohol 15.80 8.20 10.80 yes o-dichlorobenzene 19.20 6.30 3.30 no no diethylene glycol 16.20 14.70 20.50 yes diethyl ether 14.50 2.90 5.10 no no dimethylformamide 17.40 13.70 11.30 yes dimethyl phthalate 18.60 10.80 4.90 no yes dimethyl sulfoxide 18.40 16.40 10.20 yes 1.4-dioxane 19.00 1.80 7.40 no no dipropylene glycol 15.90 20.20 18.40 no ^ yes dipropylene glycol methyl ether 15.50 5.70 11.20 yes

Ethanol 15.80 8.80 19.40 yes

Ethyl acetate 15.80 5.30 7.20 yes

Ethylene dichloride 19.00 7.40 4.10 no * 3 no * 3

Hexane 14.90 0.00 0.00 yes

Isophorone 16.90 8.20 7.40 no no

Methanol 15.10 12.30 22.30 yes

Methylene chloride 18.20 6.30 6.10 yes N-methyl-2-pyrrolidone 18.00 12.30 7.20 no no

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Solubility

Solvent </ q / p ^ 10 min. 24 hrs.

Nitrobenzene 20.00 8.60 4.10 yes 2-nitropropane 16.20 12.10 4.10 yes

Propylene carbonate 20.00 18.00 4.10 yes

Propylene glycol monomethyl ether 15.60 6.30 11.60 yes

Tetrahydrofuran 16.80 5.70 8.00 yes

Toluene 18.00 1.40 2.00 no no

Trichlorethylene 18.00 3.10 5.30 no no a) Should have been inside the calculated ball b) Should have been outside the calculated ball EXAMPLE 5 In a similar way to Example 1, possible solvents for the vinyl binder based ink are selected. 5 col® MW 043 on the basis of solubility tests and Han late parameters.

The results obtained are shown in Table 6.

TABLE 6

Solico range of Sericoi® M \ l 043.

/ D = 17.55 </p> 10.30 = 7.26 Rp = 6.93

Solubility

Solvent cfp 10 min. 24 hrs.

Acetone 15.50 10.40 7.00 yes

Acetophenone 19.60 8.60 3.70 Yes 1,3-Butanediol 16.60 10.00 21.50 No No 1-Butanol 16.00 5.70 15.80 No No

Butyl acetate 15.80 3.70 6.30 jaa J + butyrolactone 19.00 16.60 7.40 jaa

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21 O p 1 ø s e 1 i g h e d

Solvent ^^ 10 min. 24 hrs.

Carbon tetrachloride 17.80 0.00 0.60 no no

Chlorobenzene 19.00 4.30 2.00 no no

Chloroform 17.80 3.10 5.70 yes

Cyclohexanol 17.40 4.10 13.50 no no

Diacetone alcohol 15.80 8.20 10.80 no * 3 no * 3 o-dichlorobenzene 19.20 6.30 3.30 no * 3 no diethylene glycol 16.20 14.70 20.50 no no diethyl ether 14.50 2, 90 5.10 yes dimethylformamide 17.40 13.70 11.30 no no dimethyl phthalate 18.60 10.80 4.90 no yes dimethylsulfoxide 18.40 16.40 10.20 yes 1,4-dioxane 19.00 1, 80 7.40 no no dipropylene glycol 15.90 20.20 18.40 no no dipropylene glycol methyl ether 15.50 5.70 11.20 no no

Ethanol 15.80 8.80 19.40 no no

Ethyl acetate 15.80 5.30 7.20 no * 3 yes

Ethylene dichloride 19.00 7.40 4.10 no * 3 no

Hexane 14.90 0.00 0.00 yes

Isophorone 16.90 8.20 7.40 no no

Methanol 15.10 12.30 22.30 yes

Methylene chloride 18.20 6.30 6.10 yes N-methyl-2-pyrrolidone 18.00 12.30 7.20 yes

Nitrobenzene 20.00 8.60 4.10 yes 2-nitropropane 16.20 12.10 4.10 no no

Propylene carbonate 20.00 18.00 4.10 no no

Propylene glycol monomethyl ether 15.60 6.30 11.60 no no

Tetrahydrofuran 16.80 5.70 8.00 yes

Toluene 18.00 1.40 2.00 no no

Trichlorethylene 18.00 3.10 5.30 no no * 3 a) Should have been inside the calculated ball b) Should have been outside the calculated ball EXAMPLE 6 22

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In the same way as in Example 1, possible solvents for the vinyl binder-based inks Sericol® "Polyplast PY-043" are selected based on solubility experiments and Hansen parameters.

The results obtained are shown in Table 7: TABLE 7

Solubility range for Sericol® "Polyplast PY-043" iD = 19.37 Jp = 8.73 ^ = 5.91 Rp = 8.74

Solubility

Solvent £ p ^ 10 min. 24 hrs.

Acetone 15.50 10.40 7.00 yes

Acetophenone 19.60 8.60 3.70 yes 1.3-butanediol 16.60 10.00 21.50 no no 1-butanol 16.00 5.70 15.80 no no

Butyl Acetate 15.80 3.70 6.30 Yes ^ -Butyrolactone 19.00 16.60 7.40 Yes

Carbon tetrachloride 17.80 0.00 0.60 no no

Chlorobenzene 19.00 4.30 2.00 yes

Chloroform 17.80 3.10 5.70 yes

Cyclohexanol 17.40 4.10 13.50 no no * 3

Diacetone Alcohol 15.80 8.20 10.80 No * 5 Yes O-Dichlorobenzene 19.20 6.30 3.30 Yes Diethylene Glycol 16.20 14.70 20.50 No No Diethyl Ether 14.50 2.90 5.10 No no dimethylformamide 17.40 13.70 11.30 yes dimethyl phthalate 18.60 10.80 4.90 no yes dimethyl sulfoxide 18.40 16.40 10.20 yes 1.4-dioxane 19.00 1.80 7.40 yes dipropylene glycol 15 , 90 20.20 18.40 no no

DK 153797 B

23

Solubility

Solvent ^) p ^ 10 min. 24 hrs.

dipropylene glycol methyl ether 15.50 5.70 11.20 no no

Ethanol 15.80 8.80 19.40 no no

Ethyl acetate 15.80 5.30 7.20 yes

Ethylene dichloride 19.00 7.40 4.10 yes

Ethylene glycol monoethyl ether acetate 15.90 4.70 10.60 yes

Hexane 14.90 0.00 0.00 no no

Isophorone 16.90 8.20 7.40 no yes

Methanol 15.10 12.30 22.30 no no

Methylene chloride 18.20 6.30 6.10 yes N-methyl-2-pyrrolidone 18.00 12.30 7.20 yes

Nitrobenzene 20.00 8.60 4.10 yes 2-nitropropane 16.20 12.10 4.10 yes

Propylene carbonate 20.00 18.00 4.10 no yes

Propylene glycol monomethyl ether 15.60 6.30 11.60 no no

Tetrahydrofuran 16.80 5.70 8.00 yes

Toluene 18.00 1.40 2.00 no no

Trichlorethylene 18.00 3.10 5.30 yes a) Should have been inside the calculated ball b) Should have been outside the calculated ball

From the above examples, it can be seen that for each ink, several solvent candidates can be found, which, according to the Hansen model, fall within the solubility range, but which (5) due to existing environmental requirements are unusable in practice, (b) on due to slow dissolution effect are useless in practice, cf. the previously mentioned time parameter, or

DK 153797 B

2 µl (c) is without effect on one or more of the usual inks.

EXAMPLE 7

This example shows that the comparative mixtures EX EX I A, EX I B, EX I C, and EX 2 destroy the adhesive systems used in the screen printing more than the liquid mixtures 0 and V according to the invention.

The following commercial adhesive systems based on two-component epoxy or polyurethane were used; 1. 10¾ hardener, as prescribed by the manufacturer.

2. 10¾ hardener as prescribed; After 1 day of curing, coat with varnish to cover all glue.

3. 20¾ hardener, where the frame is pre-coated with adhesive mixture, which is cured for 1 day prior to tissue adhesion.

Solvent mixtures EX I (according to EP Publication No. 81,355) U / V% A 72.93 N-methyl-2-pyrrolidone 20.01 Ethylene glycol monobutyl ether 5.56 Cyclohexanone 2.50 Synperonic® NP 9

EX I V / V S

B 44.49 N-methyl-2-pyrrolidone 50.91 Ethylene glycol monobutyl ether 2.50 Cyclohexanone 2-, 10 Synperonic® NP 9

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25

EX I v / V S

C 37.18 N-methyl-2-pyrrolidone 20.01 Ethylene glycol monobutyl ether 40.31 Cyclohexanone 2.50 Synperonic® NP 9 EX 2 (according to EP Publication No. 81,355) V / V% 38.14 N-methyl-2 -pyrrolidone 12.75 Ethylene glycol monobutyl ether 1.66 Cyclohexanone 25.67 Ethylene glycol monoethyl ether acetate 20.44 Methylene chloride 1.34 Synperonic® NP 9

V V

c v / h% V / V%

Isopar L 29.9 28.7 DPM (dipropylene glycol monomethyl ether) 16.1 15.5 PMA (propylene glycol monomethyl ether acetate) 59.7 38.3 (butyrolactone 9.3 12.5

Synperonic ^ NP 9 5.0 5.0

A maximum of 15 W / W% of butyrolactone may be added if homogeneous liquid is desired.

DK 153797 B

26> Liquid mixture V with various amounts of N-methyl-2-pyrrolidone

VA V0 "F

v / v s υ / ν s v / v s

Isopar L 29.6 26.84 25.2 DPM 16.0 14.48 13.6 PMA 39.3 35.61 33.4 N-methyl-2-pyrrolidone 10.1 18.05 22.7

Synperonic® NP 9 5.0 5.0 0.02 5.1 Liquid mixture V with various amounts of β-butyrolactone and N-methyl-2-pyrrolidone

VB "E

U / V% M / \ I S

Isopar L 29.8 25.2 DPM 16.0 15.0 PMA 39.5 36.8 3 -butyrolactone 4.6 8.5 N-methyl-2-pyrrolidone 5.1 9.3

Synperonic® NP 9 5.0 5.2

DK 153797B

27 Liquid Mixture O with Various Amounts of -Butyro-Iactone

0 ° I ° L

V / V% V / V% V / V «

Isopar L 12.0 11.2 10.6 PMA 14.4 13.4 12.7 DB (diethylene glycol monobutyl ether) 27.4 25.6 24.1 DPM 32.0 29.9 28.2 β-Butyrolactone 11 , 6 17.2 21.7

Synperonic® NP 9 2.6 2.7 2.7 Liquid mixture 0 with different amounts of N-methyl1-2-pyrrolidone

° G ° J ° M

v / v% v / v% v / v%

Isopar L 11.9 11.0 10.4 PMA 14.2 13.2 12.4 DB 27.5 25.2 23.7 DPM 31.0 29.5 27.7 N-methyl-2-pyrrolidone 12, 8 18.5 23.2

Synperonic® NP 9 2.6 2.6 2.6

DK 153797B

28 Liquid mixture O with various amounts of -butyrolacone and N-methyl-2-pyrrolidone

° H ° K ° N

U / MJ. % V / V% V / V%

Isopar L 11.9 11.1 10.5 PMA 14.3 13.3 12.6 DB 27.2 25.4 25.9 DPM 31.9 29.7 28.0 Y-butyrolactone 5.8 8.6 10.7 N-methyl-2- 6.3 9.3 Hj7 pyrrolidone

Synperonic® NP 9 2.6 2.6 2.6

Synperonic® NP 9 = Surfactant Isopar L = Isoparaffinic solvent, flash point 64 ° C.

In the experiments described below, a subjective evaluation of the adhesive's continued function is made. Given that different washing methods exist (in some cases, the frame is fully immersed in the liquid, while in other cases 5 a brief spray of the cleaning fluid is performed), a visual / mechanical assessment is made of whether the adhesive is still good enough for the tissue to withstand the powerful effects of continued printing. In the present experiments, the frames have been fully immersed in the liquid for the periods indicated in Table 8.

Assessment is done using a scale that expresses increasing destruction of the glue system. Values of 15 and above indicate that the glue system is damaged and cannot be used for continued printing while the value 14-15 indicates that the glue system will be just reusable. The lower the number, the better the adhesive system has been able to withstand the treatment with the cleaning fluid. Measurements have been made on the three above adhesive systems.

Table 8 29

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Results of glue test + dissolves the varnish * = falls off ^ Glue system 1. 2. 3.

time (hours) 1.5t 2.5t 3.5t l, 5t 2.5t 3.5t l, 5t 2.5t 3.5t

Pregan 240 E 0 0 0-1 -1-0 -1-0 000-1 V 6 8-9 8 5 4 5 4 6-7 6 VA10.1 * NM2F 8 9 10-11 6 5 6-7 5 -6 7-8 7-8 VB 9.7% NM2P / BLO7-8 10 10 6 6 6 6 8 7-8_

Vc 12.5% BL0 6-7 11-12 12 7 10-11 11 6 8 7

Ujj8p5% NM2P 13 13-14 14-15 11 13 10 9 12 12

Ve17.8% NM2P / BLO 7-8 13-14 12 9 12 10 10 10-11 12 V p-22.7% NM2 P 13-14 13-14 12 14 14 11-12 12 12 0 11.6% BL0 4-5 7 6-7 2 3 5-6 4 5-6 4-5 0g12.8% NM2P 3-4 8 6-7 2 4 5-6 4 6 4-5 0 ^. 12.1% NM2P / BLO 4-5 9 8 2 4 6-7 5 5 6 --- 1- ------------------------- ------- 0 17.2 * BLO 6 8 11-12 4-5 4 6-7 4 5-6 5-6

Oj 18.5% NM2P 8 9 11 3 4-5 6 5 8-9 8-9 0K 17.9% NM2P / BLC 7 8-9 11 3 4 7 5-6 8-9 7 0 ^ 21.7% BLO 7 6 11 3 '6 6 4-5 6 7 0M 23.2% NM2P 8-9 11 10 4-5 6 6 6-7 9 9-10 0N 22.4% NM2P / BLO 6-7 12 12 4 -5 6 8 6 9 8 EX IA 11 14 15 + * * * 16 * * 16 EX IB 12 14 15 9+ 14 14 14 15 15 EX IC 13 13 14-15 13+ 14-15 * 14 14-15 15 EX 2 14 14 14 14+ 14-15 15 14 15 15 V contains 9.3% β-butyrolactone (BLO) 0 contains n, 6% β-butyrolactone NM2P = N-methyl-2-pyrrolidone

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30

The results show that EX IA, EX IB, EX IC and EX 2 destroy all three adhesive systems and that the more the adhesive systems are destroyed, the more γ-butyrolactin and N-methyl-2-pyrrolidone respectively added to the liquid mixtures 50 and V according to the invention.

EXAMPLE 8 In the same manner as described in Example 7, a further number of liquid mixtures Α * Ι according to the invention have been performed, and it has been found that comparative mixtures EX IA, EX IB, EX IC and EX 2 mentioned in Example 7, the glue system destroys more than the liquid mixtures AI, the compositions of which appear in the following Table 9.

In the experiments, the commercial adhesive system No. 1 described in Example 7 was used.

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31

Table 9

Tested liquid mixtures according to the invention Composition in V / V%

Mixture Ύ'-butyro-N-methyl-2-DPM PMA DB PM lactone pyrrolidone A 1.0 - 49.0 30.0 20.0 B - 1.0 49.0 30.0 20.0 C 0.5 0.5 99.0 - D 5.0 95.0 - E - 5.0 95.0 - F 2.5 2.5 50.0 45.0 - G 1.0 - - - 99.0 H - 1.0 99.0 I 0.5 0.5 - 99.0 - DPM: Dipropylene glycol monomethyl ether PMA: Propylene glycol monomethyl ether acetate DB: Diethylene glycol monobutyl ether PM: Propylene glycol monomethyl ether

The results found are shown in Table 10:

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32

Table 10

Glue test results + dissolves the varnish * falls off

Time (hours) Liquid mixture 1.5 2.5 3.5 EX I A 15 15 * EX I B 14-15 15 16+ EX I C 14-15 15 15+ EX 2 12 13-14 15+

A j 1-3 1-3. 1-3 I

B 1-3 1-3 1-3 i C 1-3 5-7 7-8 j D 1-3 1-3 6-9 E 6-7 7-8 10-11 F 4-5 5-6 9 -10 G 4-5 6-8 10-11 · H 3-4 6-7 9-10 »

I 3 5-6 9-10 I

It will be seen that, contrary to the known liquid mixtures, the liquid mixtures A-I of the invention do not destroy the adhesive system.

Claims (4)

A cleaning liquid containing β-butyrolactone and / or N-methyl-2-pyrrolidone for the removal of printing and screen printing inks, in particular for cleaning screen frames, characterized in that it consists of a substantially anhydrous mixture comprising (a) -butyrolactone and / or N-methyl-2-pyrrolidone in an amount of 1 - 25%, preferably about 10% (v / v) and (b) one or more propylene glycol derivatives selected from substituted propyl acetates of the general formula CH ? Wherein R is hydrogen or alkyl of 1-6 carbon atoms, and / or propylene glycol ethers of the general formula ch3 R, -O- (CH9-CH-O) -H, 1. n wherein R 1 is alkyl of 1-6 carbon atoms and n is 1, 2 or 3 and optionally (c) a diluent consisting of one or more aliphatic hydrocarbons having a flash point above 22 ° C and / or a ether selected from butyl diglycol ether, ethyl diglycol ether and methyl diglycol ether (d) a surfactant wherein the amount of components (c) and (d) constitutes a maximum of 50% (v / v) of the liquid. ; DK 153797B Liquid according to claim 1, characterized in that R is methyl or ethyl. Liquid according to claim 1, characterized in that it contains as component (b) one or more propylene glycol ethers selected from propylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether and tripropylene glycol monomethyl ether. Liquid according to claim 1, characterized in that it contains a surfactant, preferably in the form of a nonylphenol ethoxylate.