DE2151189A1 - Solvent, process and apparatus for its manufacture, and its use in printing inks - Google Patents

Description

PATENT Attorney O Λ Μ 1 Q Q

DIPL-ING. ZIOI IOC?

HELMUT. GÖRTZ

srf> nid «nh ^ f !. χτΊτΛοτοη ^'12 * ^{October 1971}

Gzy / Ha.

The Valspar Corporation, Minneapolis, Minnesota, U.S.A.

Solvent, process and apparatus for its manufacture, and its use in printing inks.

The invention relates to paints, printing inks and solvents, their production and use,

Paints are mixtures of a liquid and one or more pigments in powder form. The liquid which that contains pigment is called a carrier. They can be solvents or thinners, binders, desiccants and plasticizers contain. Typical solvents are turpentine, petroleum distillates, aromatic hydrocarbons and the like. Most solvents are organic. In the following, the term "paints" also refers to printing inks, Means colorants and the like made from pigments and vehicles or solvents.

In the manufacture of paints, a carrier is mixed with a pigment in a mill, e.g. in a ball mill, a sand mill or a roller mill. In the mill, the pigment particles are dispersed into the carrier. This process is called it is used as grinding, but the pigments are only slightly broken down, and essentially only one is found mechanical dispersion takes place. The procedure carried out in this way takes up to twelve to sixteen hours. The capacity a mill could be increased if it succeeds in reducing the time for this treatment significantly. After grinding

209Ö 17/1317

you add other carriers, solvents and dryers to the paste. The dyer then adds further pigments to the paint, to achieve the desired shade. In the laboratory, the paint is then checked for compliance with the regulations checked. The paint is then strained, stored and finally packaged.

The manufacture of paints, printing inks and the like ™ is flammable because flammable materials are used. Such a fire hazard exists, for example, in the mill, where the pigment is ground and the temperature rises in the process. Another fire hazard is where the material, like printing ink, is applied with a press. One by static Charging generated sparks can ignite the volatile solvents and cause an explosion. It is beneficial suppress flammability and thus reduce the risk of fire.

Paints can be stored in the factory in an unopened container or after opening the container. oxidize ters. Solvents can also be lost in the empty space above the paint. consumer know the skin formation on paints caused by oxidation. A product that does not or only little is therefore desirable oxidized and from which no solvents are lost during storage.

Investigations have shown that the vapors of certain organic solvents lead to photochemical contamination under biological conditions.

ozone, aerosols and compounds that are irritating to the eye. The evaporation of organic solvents works so polluting the air. It is therefore desirable to prepare paints in such a way that no solvents get into the Atmosphere. The loss of solvents here

209817/1317

_ ■ 3 -

according to the current state of the art up to h%, which means an economic loss.

The invention relates to a carbon dioxide-containing product for use in paints and printing inks. It consists of a volatile organic solvent and gaseous carbon dioxide in an amount greater than 1 part by volume each Part of the volume of the solvent is contained in this. The carbon dioxide mixed solvent can also be mixed with a pigment are mixed to form a paint or a printing ink.

The invention also relates to a process for the preparation of an organic solvent to which carbon dioxide has been added. Man treated the organic solvent with an atmosphere of carbon dioxide under such a pressure that more than 1 part by volume Carbon dioxide per part by volume of the solvent absorbed by this will.

The invention also relates to a method for producing a paint or a solvent by incorporation of pigment, gaseous carbon dioxide and an organic solvent in a mill. There the pigment and The organic solvent is ground in the presence of gaseous carbon dioxide to the energy level and the Brown's To increase agitation of the particles and to improve the dispersion of the pigment in the organic solvent.

The invention also relates to a device for carrying out this method. The device contains a mill for grinding the pigment and the solvent, means for enclosing the

2 ü 9 8 1 7/1 3 1 7

Mill and to seal it against "the atmosphere and means for introducing gaseous carbon dioxide into the mill during milling.

The invention also relates to a printing method using the printing inks according to the invention. This is the carbon dioxide containing ink placed in a container on the printing press. This printing ink is then subjected to direct pressure through the printing device is applied to the material to be printed such as paper "or the like.

The general aim of the invention is to eliminate the above-described drawbacks of the prior art through use a paint or a printing ink containing a pigment and an organic solvent.

Another object of the invention is a less flammable one End product. Yet another object of the invention is an end product which creates an inert atmosphere over it. A Another object of the invention is an end product which skins during storage. Even more fc Objectives of the invention are a method and a device for Production of paints and printing inks in which there are lower losses of organic solvents. Yet Further objects of the invention are a method and an apparatus for producing paints and printing inks from a pigment and an organic solvent in which the pigment is better dispersed. This better dispersion is achieved by introducing carbon dioxide into the end product. Still another object of the invention is a method and one Apparatus for the production of paints and printing inks, using carbon dioxide to render the inert and pressurize the End product is used. Finally, the invention relates to

209817/1317

a printing process with the following advantages: improved printing, a reduction in static charges or a reduction in flammability.

For example, the drawings illustrate some embodiments the invention.

Show it:

Fig. 1 schematically shows a device by means of which an inventive Product can be manufactured;

Fig. 2 is a photomicrograph of a gravure print using a printing ink according to the invention;

Fig. 3 is the same, but using a conventional printing ink ; and

4 schematically shows a device for adding a solvent with carbon dioxide.

In the manufacture of paints and printing inks, it is particularly important that the pigment particles are well dispersed in the liquid carrier or solvent. For this one uses
various devices such as ball mills, sand mills, roller mills and the like. The main purpose of these mills is that
intimately mixing and wetting the solid pigment particles with the liquid carrier or solvent. This procedure is far more difficult than is usually thought. To treat mixtures that are easy to grind, e.g. when using titanium dioxide as a pigment, it takes about six hours, for grinding mixtures that are difficult to grind, e.g. carbon black,
takes up to 24 hours. In means becomes a meal

209817/13 17

Requires from 12 to 16 hours.

It has now been found that the time for dispersing the pigment can be reduced substantially, for example to about 1/3 of the time previously required or less, if the milling is carried out in the presence of a pressurized atmosphere of carbon dioxide. The carbon dioxide in larger amounts helps to better disperse the pigment in the solvent. This phenomenon is due, at least in part, to an increased energy level and increased Brown ¹ see movement caused by the carbon dioxide. According to the invention, the carbon dioxide can be introduced directly into the mill before or during milling. The pressure of the carbon dioxide should preferably be between ο.5 and 7 kg / cm.

It has also been found that these advantages can also be achieved by treating the liquid organic solvent in an atmosphere of carbon dioxide, for example in a storage container, before it is introduced into the mill. By means of a suitable regulation, the organic solvent contains the desired amounts of carbon dioxide when it is introduced into the mill. The carbon dioxide can be absorbed by the organic solvent by first pressurizing the storage container and then pumping the organic solvent into the container at a pressure higher than that of the atmosphere of carbon dioxide. Since the organic solvent absorbs the carbon dioxide, the solvent can be pumped into the container without venting it, as was previously necessary. It is estimated that up to 4 % of the solvent can be lost in the prior art venting process which, when using certain solvents, contributes to atmospheric pollution. By adding carbon dioxide to the solvent

209817/1317

the evaporation of the solvent "suppressed. Under certain Under certain circumstances, the solvent can be fed from the pressurized container to the mill without the need for a pump is required.

When the organic solvent by absorption is sufficient absorbed by carbon dioxide does not need any further carbon dioxide. fed to the mill. The pressure in the storage container is preferably at least 3.5 kg / cm for the best Achieve results. But you can also proceed in such a way that the carbon dioxide is fed to both the storage container and the mill will.

After dispersing or grinding the pigment in the liquid solvent in the mill, the product is placed in a staining container brought. There the dyer adds further solvents and pigments. Surprisingly, it was found that the present carbon dioxide not only significantly reduces the meal, but that the end product also has a better ability to be colored Has. This phenomenon also indicates better dispersion of the pigment. Correspondingly, this can be done by the mill upcoming end product contain larger amounts of solvents or diluents without affecting the hiding power of the paint or the printing ink can be reduced.

After inking, the paint or printing ink can either be stored or in a container for transport to be brought. If a solvent mixed with carbon dioxide is used during dyeing, the resultant contains Paints or printing inks have a high proportion of carbon dioxide, preferably more than 1 part by volume and up to A parts by volume of carbon dioxide per part by volume of the organic solvent in the paint or the printing ink. Part of this carbon dioxide escapes into the empty space of the container, so that

209817/1317

where an inert atmosphere arises'. In cans for paints there is the development of carbon dioxide even after repeated opening, which reduces the loss of solvents and the Prevents skin formation on the paint. When using printing inks, this phenomenon causes an inert atmosphere over the ink and reduces the risk of fire. It has also been found that a carbon dioxide-added printing ink has an increased electrical conductivity, which prevents dangerous static charges.

1 shows a ball mill 1o which consists of a large drum 12 which rotates about a horizontal axis 14. Usually the mill contains the pigment, the carrier or the solvent and balls, pieces or the like which, when the drum rotates, thoroughly disperse the pigment in the solvent. The drum 12 has a removable lid 18 over the opening 16 through which the pigment can be introduced into the mill. The solvent is supplied through line 22 through port 16. Carbon dioxide is introduced into the mill through branch line 26a which passes through a
Main line 26 is connected to the container 3o for the carbon dioxide. The carbon dioxide is preferably fed to the mill under a pressure of about 0.5 to 7 kg / cm. The branch line 26a expediently runs coaxially with the axis 14, so that the carbon dioxide can also be introduced while the drum 12 is rotating. A valve 32 is located at the outlet from the container 3o. A valve 34 and eiSSe & fer 36
may be placed in line 26a to control the flow of carbon dioxide to the mill. The drum 12 has an outlet to which a flexible conduit 24 can be connected to withdraw the final milled product.

209817/1317

The storage container 4o for the organic solvent is expedient not ventable. A second branch line 26b is connected to the container 4o and to the main line 26 to To introduce carbon dioxide into the container. In the line 26b, a valve 44 and a pressure regulator 46 are arranged to the To regulate the flow of carbon dioxide to the storage container. After filling the container with carbon dioxide under pressure, e.g. under a pressure of 3.5 kg / cm, the organic solvent is pumped through line 47 by means of a pump 48 into the container. A valve 49 is in line 4? arranged. By the pump, the organic solvent is in the container 4o introduced under a pressure which is above the pressure of carbon dioxide. The solubility of the carbon dioxide increases with it the increase in pressure. As the carbon dioxide is absorbed by the solvent, the amount of free increases Carbon dioxide. The carbon dioxide is absorbed by the solvent, so that when the solvent flows into the Container the pressure in this does not increase.

At the bottom of the storage container 4o an outlet line 52 is arranged, which leads to the line 22 and a dyeing tank 6o. A valve 54 in line 22 regulates the flow of carbon dioxide added organic solvent to the mill 1o. A valve 56 in line 52 regulates the flow to the dyeing tank 6o. It should be noted that no pump is provided to deliver the carbonated organic solvent Mill or the staining container. If desired, however, a pump can also be provided if, for example, the.,.

^to as with HiXfK des_ Koniendioxyas mqspi

Wants to convey solvents to greater heights, VEine line 57 is connected to line 52 and flexible line 24 to connect the mill 1o to the dye container 6o. On the line 57 a valve 58 and a pump 59 are arranged to regulate the flow from the mill 1o.

2 0 9 817/1317

In a conventional manner, the dyeing container 60 contains a mixer or stirrer 62 which is driven by a motor 64. This mixes the ground pigment and the solvent with other solvents, pigments or additives. The container has an opening 66 through which additional pigments and additives can be added. The opening 66 has a lid
68 by which the container 60 can be sealed. The container has a poppet valve 72 for venting it. ¥ enn der
If lid 68 does not seal the container, care should be taken
be that in it a slight overpressure of for example
0.2 to 0.4 kg / cm prevails. The free space above the mixture is filled with carbon dioxide from the paint or the
Ink escapes. This will reduce the risk of fire
and prevents evaporation of the solvent. In most cases the carbon dioxide evolved is sufficient for this purpose. But you can also use the container with the main line 26
a branch line 26c with a valve 74 and a pressure regulator 76. In this way, the container 60 can be an inert
Contain atmosphere even if there is no end product in it.

In the manner described in this way, a paint or
an ink containing carbon dioxide. The final product can be put into a container or jug 80 by the with the container
60 connected line drained v / earth. A pump 84 and a
Valves 86 regulate the flow through line 82. This bleeding can be done either automatically or by hand.

209817/1317

The end product in can 80 preferably contains more than 1 part by volume of carbon dioxide per part by volume of organic solvent and up to 4 parts by volume of carbon dioxide per part by volume of the organic solvent. In this way the carbon dioxide escapes in the free space in the container and creates an inert atmosphere. It was found that this released carbon dioxide prevents the evaporation of the solvent in the case of paints and the tendency to skin formation is reduced. In the case of printing inks, the carbon dioxide developed creates protection even in open areas Containers, which helps to suppress flammability.

It has been found that the presence of carbon dioxide in organic Solvents whose flash point increases, which also reduces flammability. It was also found that the The presence of carbon dioxide increases the electrical conductivity of the solvent. This results in much lower static Charges that can cause an explosion.

When printing inks according to the invention are used, up to 20 % better printing is achieved. The carbon dioxide-mixed printing ink therefore covers better. This phenomenon can perhaps be explained by the fact that the printing ink according to the invention conducts better and less static charges arise on the printing rollers.

The following examples illustrate the invention.

209817/1317

example 1

Parts by weight 1. Benziden-Yellow ~

2. Primrose-Chrome-Yellow 1588

3. Toluene 361

4. Ethyl cellulose solution 25 % NV in a hydrocarbon 962 used as a thinner for paints

5. Zinc resinate and a solution of ethyl cellulose *. 4962

w 6. Hydrocarbon used as solvent for lacquers 1784

* This component had the following Composition in percent by weight:

Zinc resinate 37% Ethyl cellulose 3 % Paint thinner 5 % Acetone 7% Isopropyl alcohol 11 % Hexane 25 % toluene 12 %

It is a yellow printing ink. Ingredient 6 is added after grinding. Components 1 to 5 were ground in a laboratory ball mill. The mill contained 2,388 grams of steel balls. Four equal mills were for used the experiments with each mill running the same number of revolutions for the same time. One ■ The mill contained a comparative sample, the other mills were supplied with carbon dioxide under the specified pressure. It was Stabilized for an hour and then re-pressurized. Different attempts have been made with different Meals carried out. Ingredients were then diluted 1 to 5. Each sample was checked for the fineness of grind, using a North Standard grind gauge. The opti-

209817/1317

see density was measured with a densichrom densitometer, the manufactured by Welch Scientific Co., Skokie, 111.. Here the following results were obtained.

Trial meal CO, fineness increased coloring power

1 H.

1 H.

.1 H.

1 H.

2 hours 2 hours 2 hours 2 hours 4 hours 4 hours 4 hours 4 hours

1.ο kg / cm * 3.5 kg / cm * 5.3 kg / cm *

1, ο kg / cm * 3.5 kg / cm ^ 7.o kg / cm *

1, ο kg / cm ^ 3.5 kg / cm ^ 7, ο kg / cm ^

2.5

5.5

6.5

Comparison 4%

%

Comparison %

7% 9% comparison

8%%%

Example 2

Raven 4o Black Densed Atomite

Nuact Paste 13 % Bentone O = - 38 Slurry Medium Oil Alkyd Resin (Fed. S]

TT-R-2I

) ec.

J6 Type 3)

Methyl ethyl ketoxime 24% lead naphthenate 4% calcium Mineral oils Same as ingredient 5 Polyurethane resin modified with oil 60% NV in mineral oils

6 ^ cobalt naphthenate 6 ounce manganese naphthenate

209817/1 3

Parts by weight

122

3oo

153

918 6

37 25 319 2223

649 12 12

It is a black enamel color. The parts 1 to 9 were ground according to Example 1, with the difference that 15 hours were allowed for stabilization. Ingredients 10 to 13 were added after milling. The finished product was diluted with a paste of titanium dioxide. The measurements were carried out as in the example 1 is described. As a result, the following results were obtained.

Try meal CO,

Fineness increased coloring power

4th game 4th 3 Hours. 4th Hours. 4th Hours. 4th Hours. at

1.ο kg / cm * 3t5 kg / cm * 7.o kg / cm *

/ j , 5 comparison £ ψ , 5 4% 5 8 % 5 , 5 14%

The ingredients according to Example 1 were placed in a ball mill, with the difference that the components 3 to 6 with carbon dioxide under a pressure of 7, okg / cm with carbon dioxide were treated. So the solvent had already been mixed with carbon dioxide. At the same time a comparison sample was made processed. The final products were made following the procedure of the example 1 treated further. When they were examined, the following results were obtained.

attempt Enjoy the meal co ₂ kg / cm fineness increased coloring power 5 2.5 hours - 3.5 comparison 2.5 hours 7, o kg / cm 4th 6 % 6th 6 hours - 4.5 comparison 6 hours 7, ο A, 5 13 %

209817/1317

Example 4

The ingredients of Example 1 were used, with the exception that 6,890 parts of xylene were used as the ingredient. All ingredients were treated with carbon dioxide at various pressures prior to milling. Here were the following Get results.

attempt

Meal CO,

Fineness increased coloring power

7th 4 hours Example 5 Benziden yellow o, 5 kg / cm 4th 75 comparison one 4 hours 1. Primros e-chrome-yellow 1, o kg / cm 4th 7 # 4 hours 2. VM&P naphtha 1.7 kg / cm 4, 21 % 4 hours 3. 3.5 kg / cm 4th 75 15 50 4 hours 4th 5.3 kg / cm 4th 9 % 4 hours 7, ο kg / cm 4, 9 # 4 hours VJl 14% Parts by weight 318 in 17o2 Ethyl cellulose solution 25% 1p64 N.V.

Hydrocarbon used as a thinner for paints ■ 1 o64

5. Zinc resinate and a solution of ethyl cellulose 532o

6. Toluene '532

Components 3 to 6 were previously treated with carbon dioxide as described in Example 3. It became the following Get results.

20S817 / 1317

attempt Enjoy the meal 6th Hours. ^C0 2 kg / cm Fexnhe.it increased dyeing capacity 8th 4th Hours. - 6th Comparison. 4th 7, ο 6.5 12 % example

The ingredients according to Example 1 were milled for four hours and then diluted. Different samples of this ink were then treated with carbon dioxide for different prints and stirred for 15 minutes. As a result, the following results were obtained.

attempt Enjoy the meal CO 2 kg / cm Delicacy increased color and strength 9 - - kg / cm - Comparison - 2, 1 kg / cm 4 % - 3, VJl 5 % 7, O 1o%

The above examples show that in paints and printing inks which are easy and difficult to grind, the pigments have one have improved fineness when milled in the presence of carbon dioxide. With the carbon dioxide can deviate the solvents are added beforehand or it can be introduced into the mill. The examples also show that the The addition of carbon dioxide before, during or after grinding improves the coloring power of the end product. You can see that a lot various organic solvents can be used.

To reduce skin formation by treating with carbon dioxide To show, two different varnishes, which normally form skins, were tested. These were the same compared with carbon dioxide-added varnishes. It was a polyurethane, varnish and ura one Phenolic-Wood Oil Marine Gloss Varnish. One pattern each was made

2Ü981 7/1317

BATH ORIGINAL

- 17 -

a pressure chamber at a pressure of 1.o kg / cm "in open * Treated carbon dioxide. After removing from the print

The lids were put on in the chamber. The jugs were at room temperature stored together with other samples in the same jugs that did not contain carbon dioxide. At time intervals the cans were opened and the skin formation was checked. Before resealing, the gas was blown away in the empty space. Treatment with carbon dioxide significantly delayed skin formation.

Polyurethane Gloss Varnish

Days without carbon dioxide with carbon dioxide 0 attempt started attempt started

3 Formation of a soft decrease in pressure on opening; Skin on the lid no skin formation

5 Formation of a skin on no skin formation, none of the surface of the fir- pressure when removing the nisses, the skin on the lid tightly lid

^1o firm skin on the varnish

firm skin no skin formation

firm skin no skin formation

firm skin no skin formation

Phenolic-Wood Oil Marine Varnish

without carbon dioxide with carbon dioxide 0 experiment started experiment started 3 skin formation on the lid pressure decrease when opening;

and no skin formation on the surface

of the varnish

5 firm skin no skin formation, none

Pressure decrease

no skin formation no skin formation

Formation of a soft skin on the lid and on the surface

* Provided with a Friction ^ ⁵ varnish.

209817/1317

1o fixed skin 14th fixed skin 2o fixed Ha μt 27 fixed skin

To illustrate the effect of the treatment with carbon dioxide on the flash points, various solvents were kept under a pressure of 3.5 kg / cm under carbon dioxide for 12 hours. The flash points were determined with a closed TAG tester for liquids below 80 ° C., which is available from CJ. Tagllabue Mfg. Co., Brooklyn, New York. Treatment with carbon dioxide increased the flash points in each case. The flash points given in the table below are the mean values of three tests.

Material with carbon dioxide (° C) without carbon dioxide ( ⁰ C)

Mineral oils 44 43 Xylene 33 26th toluene 7th 4th VM&P Naptha 13th 11

To illustrate the effect of the treatment with carbon dioxide Various solvents were treated with carbon dioxide under a pressure of 7 kg / cm for electrical conductivity, Their conductivity was measured with a DeVilbiss-Microampere-DC- Meter measured. The treatment with carbon dioxide increased the conductivity in each case.

Carbon dioxide material without carbon dioxide

N-butyl alcohol 65 et al. 3o et al

Isopropyl alcohol 68 et al. 54 et al

Acetone 8o et al. 68 et al.

The dispersion improves approximately proportionally to the pressure of carbon dioxide within a range of approximately 0.5 to 7

209817/1317

kg / cm. Treatment with carbon dioxide also leads to a improved coloring power in all prints between 0.5 and 7 kg / cra, but here the increase in coloring power is not always proportional to the pressure. With greater coloring power and better dispersion, the products have a brighter color. By the treatment with carbon dioxide before, during or after the grinding v / earths more than 1 part by volume of carbon dioxide per part by volume of the Solvent added. The final product contains two 1 part by volume and 4 parts by volume of carbon dioxide per part by volume of the solvent. Alcoholic solvents can be slightly larger Absorb quantities of carbon dioxide.

As shown above, end products treated with carbon dioxide, e.g. printing inks, advantages of using with themselves. These benefits include improved printing, a Decrease in static charges in the press and lower flammability.

Usually, a printing ink is usually diluted by adding an equal amount of an organic solvent before it is placed in the press container. The advantages indicated above can be achieved by replacing the usual solvents with solvents which have been treated with carbon dioxide. The organic solvent preferably contains so much dioxide that the finished printing material contains more than 1 part by volume of carbon dioxide per part by volume of the printing ink. So if the finished printing ink consists to 50% of an organic solvent, as it is usually used, then this solvent should contain more than 2 parts by volume of carbon dioxide per part by volume of the solvent.

209817/1317

- 2ο -

Of course, such organic solvents can also be used for dilution use · that contain more than 1 part by volume of carbon dioxide per part by volume of the organic solvent. Here too the same advantages are achieved «.

For example, various organic solvents have been used

Treated carbon dioxide under a pressure of 7 kg / cm until equilibrium was reached. The following values are mean values out of three attempts each.

Organic solvent Parts by volume of carbon dioxide Hexane 14.3 Heptane 11.6 Mineral spirits 1o, 9 VM&P Naptha 11.1 toluene 14.8 Xylene 12.2

These are used for printing with the printing inks according to the invention placed in a container. From this, the carbon dioxide-mixed printing ink reaches the printing device, where it is located direct pressure is applied to the material to be printed.

Experiment 1: A common yellow printing ink with a common solvent (Tolusol 3o) was used for printing on an engraving press. The ink was then replaced by a yellow printing ink that contained more than 1 part by volume of carbon dioxide per part by volume of the solvent. Copies of each Prints were compared for printability, color tone, strength and other properties. At the edge of every attempt they were static charges on the cylinder were measured with a WSM-2950 static meter from the Western Static Eliminator Company. Dam

209a17 / 13 1 7

the usual printing ink and the carbon dioxide-treated printing ink were placed in cans of 0.25 liters and ignited. Here the following results were obtained:

1) No press trouble was observed.

2) The printout has been increased.

3) The static charges increased from 35,000 to 40000 volts with the usual printing ink to 10,000 to 15,000 volts the carbon dioxide-mixed printing ink.

4) The usual ink burned off quickly, while the carbon dioxide ink only glowed, but instantly himself went out.

Experiment 2: The procedure of Experiment 1 was repeated using yellow, red, blue and black inks. The following results were obtained:

1) and 4) As in experiment 1.

2) Printing has been improved. Figures 2 and 3 are photomicrographs of lithograph prints with yellow inks, one of which was treated with carbon dioxide. In the area of FIG. 3, about 27 pressure points are missing, which is denoted by 92 is. In the area of FIG. 2, only about 7 pressure points are missing, which is denoted by 92 '. The pressure points with the Carbon dioxide-treated printing inks are more regular and more clearly delineated. There is less smearing instead of between the pressure points, as shown for example 94 in FIG. 3. The white spots in Figures 2 and 3 are originated when taking photos and do not need to be taken into account

to become. _{at ? consecutive days} _

3) The static charges were measured in three tests each. The mean values are given in the table below.

209817/1317

Day 1:

co ₂ yellow V Red V blue V black with co ₂ 75oo BC 9ooo V 1o 5oo V 35oo V without 2: 24 ooo 18ooo 18,000 28,000 BC Taffeta

with CO,
without CC

13,000 V 17,000 V

1o 5oo V 17,000 V

18,000 B.C.
16 500 B.C.

19,000 V 57,000 V

Experiment 3: The procedure of Experiment 2 was repeated, working at a humidity of 46 % and a temperature of 19 ° C. The following results were obtained

obtain.

1), 2) and 4) As in experiment 1.

3) The static charges averaged 25,000 volts with conventional printing inks to about 1,000 volts for printing inks

with carbon dioxide.

It was also found that better results were obtained using carbon dioxide treated inks in US Pat a press used to check plates for proper etching.

The improved pressure of Figure 2 is surprising. It can be accepted that this phenomenon can be explained in the case of printing inks treated with carbon dioxide by the fact that they escape the carbon dioxide from the printing ink this is mechanically stirred or that the temperature is increased here. In a Engraving press, the printing ink is relatively quiet in the container. When the roller of the engraving cylinder through passes through the container with the ink, the carbon dioxide treated ink becomes relatively dormant Conditions recorded. Immediately afterwards, a steel squeegee scrapes off the excess printing ink. This squeegee works under considerable pressure at high speed compared to

20 9817/131 * 7

the speed of the roller of the cylinder. This does two things. There will be strong shear agitation on the surface of the ink under the squeegee, which is likely to increase the temperature locally. These both circumstances cause the carbon dioxide to escape. Perhaps the volume of the ink with the bubbles of carbon dioxide becomes Enlarged so that it sits high on the roller and lighter from paper and from the depressions of the engraving roller is recorded. It is possible that the carbon dioxide also reduces the surface tension of the printing ink, which leads to the results mentioned leads.

When adding the printing ink to the container at the press, it is advantageous to have the pigmented product in place with it to mix with a volatile organic solvent containing carbon dioxide. A device for displacing the solvent in place with carbon dioxide is shown in FIG.

Two storage containers 1o1 for the solvent are each provided with an outlet valve 1o2, which the flow to the line 1o3 regulates. The containers 1o1 with a capacity of, for example, 40,000 liters are on supports that are not shown and are fitted with an explosion-proof pump, not shown, to remove the solvent from a tanker truck to promote in the container 1o1. The storage containers 1o1 are preferably not shown with inhibitions for ignition Mistake.

A storage container 1o4 contains liquid carbon dioxide under a pressure of 20 kg / cm at a temperature of -18 ° C. This The container holds about 6 tons, is made of plastics reinforced with glass fibers and is insulated with polyurethane. The cooling

209817/1317

is supplied by the device 1o5 with o.75 hp. A vaporizer 1o6 converts the liquid carbon dioxide into gas before it is fed to gas line 1o7.

A device 114 for treating with carbon dioxide is connected to the supply line 1o3 and to a branch line 1o7a of the gas line 1'o7. The level of the liquid in the device 114 is regulated by a float 115, as described below. The amount of gaseous carbon dioxide ψ, which flows to the device 114, is controlled by adjusting des'Druckes, which is measured at the 116th After sufficient stirring, the solvent has absorbed the carbon dioxide. The carbon dioxide-added solvent can then be withdrawn through valve 117 to where it is needed, for example for mixing or for filling the container on the printing press.

In the supply line 1o3 are a pump 125, a measuring device 127i a regulating valve 124 and an electrically actuatable ball valve 128 operated by compressed air are arranged. the Pump 125 is driven by a motor 126 and presses the solvent into the container at a pressure of up to 9 kg / cm a. A bypass 1o3a around the pump has a safety valve 123.

The ball valve 128 is controlled by the float 115 in the apparatus 114 for treating with carbon dioxide. When the liquid level In device 114 sinks, float 115 operates a four-way solenoid valve 131 at the end of the branch line 1o7b of the gas line 1o7. The valve 131 leads the gas through the lines 1o7c and 1o7b so that the valve 128 is opened or is closed. Simultaneously with the opening of the valve 131 the pump 125 begins to operate and vice versa.

209017/1317

Preferably, some gaseous carbon dioxide is added to the supply line 103 before the solvent enters the device 114 reached for treatment with carbon dioxide. For this purpose, the gas line 1o7 is connected to the line 1o3 after the valve 128. Appropriately, the connection point should be at least about 3 meters before the entry of the material into the device be arranged for treatment with carbon dioxide. In the gas line 1o7 there are two isolating valves 133 with one between them Control valve 134 and a pressure regulator 135 are arranged.

The foregoing clearly shows that the invention has improved carbon dioxide paints, inks and solvents as well as an improved method of printing. The invention provides better printing and increased safety by reducing the fire hazard.

200017/1517

Claims (1)

Patent claims: 1. Volatile organic solvent for use in paints or printing inks, characterized in that it contains more than one part by volume of carbon dioxide per part by volume. 2. Solvent according to claim 1, characterized in that it contains more than two parts by volume of carbon dioxide per part by volume. 3. Solvent according to claim 1 or 2, characterized in that it contains a dispersed pigment. 4. Solvent according to claim 3, characterized in that it contains up to 4 parts by volume of carbon dioxide per part by volume. 5. A method for preparing a solvent according to any one of claims 1 to 4, characterized in that it is with a Atmosphere of carbon dioxide treated under a pressure of at least 0 »5 kg / cm. 6. The method according to claim 5, characterized in that the atmosphere of carbon dioxide is introduced into a closed vessel, in which the solvent is located. 7. The method according to claim 5, characterized in that the solvent is introduced into a closed vessel in which there is an atmosphere of carbon dioxide. 8. The method according to claim 7, characterized by the use of an atmosphere of carbon dioxide under a pressure of about 3.5 kg / cm. 2098Ί7 / 1317 9. Process for the preparation of a paint or a Printing ink according to Claim 3 or 4, characterized in that the pigment, gaseous carbon dioxide and an organic Solvents ground together in a grinder. 10. The method according to claim 9, characterized in that the Treated solvent with carbon dioxide before placing it in the mill. 11. The method according to claim 1o, characterized by the use a solvent pretreated according to claim 7 or 8. 12. The method according to any one of claims 9 to 11, characterized in, that one introduces the pigment and the solvent together and the carbon dioxide separately into the mill. 13. The method according to claim 12, characterized in that one introduces more carbon dioxide into the mill during milling. 14. The method according to claim 12 or 13, characterized in that that one introduces the carbon dioxide under a pressure of 0.5 to 7 kg / cm in the mill. 15. The method according to any one of claims 9 to 14, characterized in that that the milled product is drawn off into a mixing container and further ingredients are added to it there . 16. The method according to claim 15, characterized in that the product in the mixing container is further mixed with carbon dioxide treated solvent added. 200617/1317 17. Apparatus for producing a solvent according to claim 1 or 2, characterized by a container (1o1) i'ür the solvent, through a container (1ο4Ί for liquid Carbon dioxide with an evaporator (1o6), which evaporates the carbon dioxide before it enters the line (1o7, 1o7a), by a device (114) for treating the solvent with the carbon dioxide, which by means of a line (1o3) is connected to the supply line and the container (1o1), and through a connecting line between the line (1o7) and the line (1o3) above the device (114) for treating of the solvent with dsm carbon dioxide ,, 13. Apparatus for the production of a paint or a printing ink according to claim 3 or 4, characterized by a mill (ic) for grinding the pigment and the solvent; by a covering (IS) around the hollow. the sis is sprayed off against the atmosphere, and by means (30 _£ 26 _S 26a, etc.) for the insertion of gaseous carbon dioxide into the mill during the grinding. 19. The device according to claim 1S _r gekennsedcnnsu by a closed not to be ventilated: the Seh & lüsv \ ko) for the Lc- 'solvent- through Mittal' 3o, 26b and 3v _; to introduce. gaseous carbon dioxide in the Εΐηβ, 'χ ^ η \ ^L o) under a certain pressure by Mitxel (4T _; 4o _; -' ■ ~ i] sun introduction of the solution level in usn E ^ - keeps sr- '.urrtv- a pressure above the pressure of the Kc?; J.endic: -: ydy, and äu; .us: -. ii6 line C52 ₅ 22} from the container: · -. *. ir I-Iü; l-- ΰ, νοη:. "? ..'-" l · -.--: Lcsun- ^ smitvs. '. un ·: iilu ΐ - ^ we lead 2o. ? Method additionally Print u: - .: t i "'■ ii ^ rsndung a Brucl prepared according to claim 5 or 6: IAR; _s; dacurcli ^ skennzeichnet _s that the Kolilendioxyd ENTN & ltcnde Dmckfarta In a container of the printing press Bringu and "/ on there under direct . 20981 # / 131? BATH ORIGINAL Pressure by the printing device on the item to be printed Applies material. 21. The method according to claim 2o, characterized by the use an engraving press. 22. The method according to claim 2o or 21, characterized by the use of a printing ink that contains as much carbon dioxide contains that static charges are reduced. 23. The method according to any one of claims 2o to 22, characterized by the use of a printing ink that has as much carbon dioxide contains that there is an atmosphere of carbon dioxide above the printing ink in the container for the printing ink is. 209817/1317 Blank page