FI70038C - FOERFARANDE FOER FRAMSTAELLNING AV FAERGER TAOLANDE STAERKELSELIM OCH VID FRAMSTAELLNING ANVAENDBART TILLSATSAEMNE - Google Patents

Description

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C / 45) Patent;}; patented (} Patent raelCelat 1C CO 1000 (51) Kv.lk.7int.Cl. * C 09 J 3/06, C 08 K 3/00, C 08 L 3/02 SUOMUfinland ( 21) Patent application — Patentansökning 793809 (22) Filing date - Ansökningsdag Oct 12.79 (* = «) (23) Starting date - Giltighetsdag 04.12.79 (41) Published public - Blivit offentlig 05 0 £ gg

National Board of Patents and Registration Date of publication and month of publication. -

Patent- och registerstyrelsen '1 Ansökan utlagd och utl.skriften publicerad 31-01 .86 (32) (33) (31) Pyydetty etuoikeus - Begärd priority 0 ^ 4. 1 2.78 France-France (FR) 783 ^ 153 (71) Roquette Freres, 62136 Lestrem, France-France (FR) (72) Serge Gosset, Lestrem, Francis Pichon, Perenchies,

Michel Huchette, Merville, France-France (FR) (7 * 0 Fors sen & Salomaa Oy (5 **) Procedure Imi Additive for the manufacture of color-tolerant starch adhesives and the additive used in the manufacture - Förfarande för framstä11 Ning av färger tälande stärkelselim och vid framstä11 The present invention relates to a process for the preparation of color-tolerant starch adhesives, in particular starch adhesives for the production of corrugated board, using washing waters of flexographic equipment.

It should be noted at the outset that starch glues are generally prepared using three classical methods, the first of which, more specifically the Stein-Hall method, mixes an aqueous suspension of gelled starch (or "primary") and starch milk (or "secondary") as a gelling starch ".

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Another method uses starch milk, the grains of which are partially gelled and thus make the use of a carrier unnecessary, and these adhesives are commonly referred to as "no-carrier" adhesives.

According to the third method, a simple aqueous dispersion of ready-to-use products is used, these products containing at least one cold-water-soluble part (consisting of, for example, an amylase product, carboxymethylcellulose or polyvinyl alcohol), one particulate part and one alkaline part.

With regard to the state of the art, reference is made to English Patent Publications 1,302,942 and 1,533,170. These publications relate to the manufacture of starch adhesives, but do not allow the use of washing waters for flexographic equipment in the manufacture of said adhesives.

In addition, flexography is a printing method currently used for corrugated board printing and uses inks of complex composition with the main constituents of these inks being dyes, solvents, surfactants and others.

Finally, it should be noted that the wash water generated when washing flexographic printing equipment (basins or presses) loaded with flexographic inks is very problematic with soiling and can in no way be adjusted without other methods.

The location of the treatment plant would often appear to be disproportionate to the volume and concentration of the water being treated (concentration of the order of 1-3 X). On the other hand, even if the plant had a purification station, it would not be effective in most cases with flexographic ink washing machines, as they are very different from each other and it is very difficult to predict the composition of the washing waters.

In view of these factors, it has already been proposed to include washing waters containing flexographic inks in corrugated board adhesives, as the water can be recycled after flexographic printing, in any case highlighting the disadvantage of colors.

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It turns out that when a relatively large percentage of colors have to be made compatible with starch adhesives for corrugated boards, some of them are quite incompatible and adversely affect the solidification point of the adhesives and also often the viscosity.

To clarify these drawbacks, adhesives have been prepared for double-sided corrugated board. This term "double-sided adhesive" corresponds to an adhesive specially made for gluing a second cover or paper - a pre-assembled cover - to a duct structure.

These adhesives are prepared by the Stein-Hall method, in which a "support" is prepared by solidifying a portion of the starch with soda and then adding water, crude starch and borax.

In practice, 450 liters of water and 50 kg of corn starch have been mixed and the temperature of this milk has been brought to 45 ° C before the addition of 9 kg of soda, which allows the starch to solidify.

The mixture was stirred for 15 minutes, then the following were added in order: - 700 liters of water - 250 kg of starch - 6 kg of borax

The mixture was stirred for 15 minutes, then 35 kg of flexographic dye corresponding to 5% of the water from the second batch was added.

The color was pre-placed due to standardization issues Ford no. Measured by 4 methods to a viscosity of 20 seconds.

For preparations made with different colors, the following were measured: - viscosity Lory (flow viscosity - BRAIVE INSTRUMENTS - machines d'essais - 39 rue Bles, 400 Liege (Belgium)), - viscosity Brookfield (corrugated viscosity - viscose meter type RVF -Societe BROOKFIELD, 240 Cushing Street , Stoughton, Massachusetts, USA), 4 70038 - solidification point measured on a Brabender viscograph (BRABENDER DHG,

Duisburg), in which the preparation is heated in a viscograph and the temperature at which the crude starch of the second part solidifies, which is manifested by a strong increase in viscosity.

The results obtained with eleven flexographic colors are shown in Table I.

TABLE I

Viscosity Viscosity Viscosity Solids-Lory Lory after 4 hours Brookfield storage point (seconds) (seconds) (centipoises) (° C)

Comparison without color 19 21 280 50

Blue Reference. 1 18 18 275 55

Yellow "2 18 24 310 54

Blue "3 15.5 16 250 54

Green "4 15 16 240 54

Yellow chrome "1" "5 39 21 780 59

Yellow chromium "3" "6 not to be measured 19 29 000 58

Black "7 15 16 230 52

Red "8 43 27 2 200 56

Orange "9 17 19.5 350 53.5

Blue "10 20.5 10.5 400 54

Yellow "11 15 15 230 53.5 This table shows that all colors have a very detrimental effect on the pour point. They sometimes change it considerably and always in the upward direction.

Some colors affect viscosity. But given the fact that flexographic ink washings are mixtures, there is always at least one color that adversely affects viscosity.

70 0 3 8 In view of these disadvantages, users of flexographic paints have virtually given up the application of washing water to starch adhesives.

In order to eliminate the above drawbacks, it has already been proposed that, before washing water is used for adhesives, the harmful components of the dyes are removed by precipitation, and then removed, for example, by filtration.

Such methods are complex and require the use of substances that, with some exceptions, have not been used.

However, it is an object of the invention to obviate these drawbacks and to provide a method for producing color-tolerant starch adhesives which allows the use of flexographic machine washings in the manufacture of corrugated adhesives without adversely altering the solidification point and viscosity of the obtained adhesives.

The applicant has found that this object can be achieved by using the substances Ca, Mg, Mo, Ni, Ba, Co, Cr, Al, 3+

Fe, Zn, Sr, Pb, Sn, Ti, V, Cu, Mo, Cd, Sb, W, Bi group of salts and oxides, as well as silicoaluminates, activated carbon, cements and silicates.

3+

From said group, a substance selected from the group consisting of salts and oxides of Ca, Mg, Mo, Ni, Co, Fe and silicate aluminates, activated carbon and cements is preferably used, and preferably one more silicate is used.

It is therefore known that a process for preparing color-tolerant starch adhesives for corrugated board using flexographic equipment washing waters is characterized in that either starch for the production of these adhesives or flexographic equipment washing waters or a carrier on the other hand 3+ at least one substance from salts and oxides of Ca, Mg, Mn, Ni, Co, Cr, Fe or silicoaluminate, activated carbon, cement or silicates and optionally alkali metal hydroxide and the amount of this substance to be added when it is not silicate is 0 , 01-10, preferably 0.05-5% by weight of the total amount of starch and the substance to be added, and the amount of the substance to be added when it is silicate is 0.01-49, preferably 0.05-20% by weight of the amount of starch and the total amount of silicate.

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O

The additive according to the invention, which enables the use of printing presses in the manufacture of starch adhesives for corrugated board, according to the invention, consists of a mixture of starch used in the manufacture of corrugated adhesives and 0.05-20% by weight and most preferably 0.1-6% by weight of the amount of amulase.

The following examples illustrate the invention with respect to at least some of the above substances.

EXAMPLE 1

A double-sided type adhesive is produced (intended for use in the production of double-sided corrugated board). To do this, starch milk is made from 450 liters of water and 50 kg of starch. This milk is heated to 45 ° C.

Otherwise, 9 kg of pure soda is dissolved in 20 liters of water. This solution is added to the starch milk to solidify it and to prepare a "carrier" or primary part after 15 minutes of sufficiently vigorous mixing. Add again 700 liters of water, then 250 kg of starch, then 6 kg of borax, which forms starch milk or "secondary".

After stirring for 15 minutes, a viscosity of Lory for 15 seconds, a Brookfield viscosity of 290 centipoise and a pour point of 54 ° C are obtained.

In the second experiment, the secondary water is replaced with water containing 4% of the flexographic color formed by Yellow Chromium "1". The viscosity of Lory is then no longer measurable, and the viscosity of Brookfield rises to 20,000 centipoise, and the pour point is 58 ° C.

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The attitude of the adhesive is thus quite disturbed by the use of water containing the color of flexography.

In the third experiment, the color of the flexography of the second experiment is retained, and the secondary starch is replaced with a dry mixture of 99.4% starch and 0.6% calcium sulfate. The "shock" of the second experiment no longer occurs. The viscosity of Lory is 18 seconds, the viscosity of Brookfield is 260 cp. In contrast, the solidification point is 60 ° C and is restored with soda. As a result, the effect of calcium sulfate and soda prevents the detrimental effect of flexographic color.

In this case, the amount of sodium present is 10.8 kg.

EXAMPLE 2

Perform the same experiments as in Example 1, ie - in the first experiment (1): the general formula - in the second experiment (2): the secondary water is replaced by water containing 4% of the flexographic color Yellow chromium "3", and - in the third experiment (3): the starch is replaced by a mixture of 99.5% starch and 0.5% calcium sulphate.

The results of the measurements performed are summarized in Table II.

TABLE II

Viscosity Viscosity Solidification

Lory Brookfield dot (seconds) (centipoises) (° C)

Experiment (1) 19 280 54

Experiment (2) 39 780 58

Experiment (3) 18 240 58 8 70038

The conclusions are the same as in Example 1. It is sufficient to add additional soda (on the order of 1.7 kg). Calcium sulfate under these conditions makes it possible to prevent the harmful effect of the color Yellow Chromium ITT.

EXAMPLE 3

The experiments are the same as in Example 1, but in Experiment (3), a mixture of 99.4% starch and 0.6% calcium sulfate is replaced by a mixture of 99% starch and 1% calcium oxalate.

In this experiment (3), the viscosity Lory is 20 seconds, the viscosity Brookfield 280 cp and the pour point 59.5 ° C.

The calcium oxalate content is thus similar to the calcium sulphate content, and it is necessary to add a little soda (on the order of 1.6 kg) to completely correct the effect of the color.

EXAMPLE 4

The experiments are the same as in Example 1, but in Experiment (3), a mixture of 99.5% starch and 0.6% calcium sulfate is replaced by a mixture of 98.25% starch and 1.75% magnesium sulfate.

In this experiment (3), the viscosity Lory is then 22 seconds in a Lory viscometer, 410 centipoise in a Brookfield viscometer, and the solidification point is 61 ° C. Viscosity ratios are acceptable, but it is still necessary to add soda to correct the pour point (on the order of 1.39 kg).

EXAMPLE 5

The experiments are similar to Example 1, but in Experiment (2) the color Yellow chromium "1" is replaced by Orange (known as MILLORY as "Orange 802"), which is even more harmful to adhesives than chrome yellow. % starch and 5% ferrous sulphate.

The results are summarized in Table III.

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TABLE III

Viscosity Viscosity Solidification-Lory Brookfield dot (seconds) (centipoises) (° C)

Experiment (1) 19 290 54

Test (2) does not measure 34 800 58

Experiment (3) 18 470 69

The structure is a bit short, but the glue is very suitable. In contrast, the pour point has risen a lot. It is necessary to correct it with considerable amounts of soda, which causes in practice that ferrous sulphate is of little interest in the case of this color.

EXAMPLE 6

The experiments are similar to Example 5, but in Experiment (3), the mixture of starch and ferrous sulfate is replaced by a mixture of 99% starch and 17 ° sodium silicate (powder 2.06 of the modulus). The viscosity Lory then becomes 18 seconds. The viscosity in Brookfield is 280 cp, and the pour point is about normal at 56 ° C.

It is observed how sodium silicate seems particularly suitable while correcting the viscosity and pour point.

ESIMERKKI_7

The conditions are the same as in Example 6, but 2% of the same sodium silicate is used instead of 1%.

The viscosity Lory is then 16 seconds, the viscosity Brookfield 230 cp, and the pour point is 55 ° C.

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The values are very close to the values of Example 6. Thus, the momentum of the silicate is not destructive to the adhesive.

EXAMPLE 8

The conditions are the same as in Example 7, but no orange color is applied.

The viscosity of Lory is 19 seconds. The viscosity of Brookfield is 250 cp. The pour point is 54 ° C.

Thus, the composition is definitely not disturbed by the presence of sodium silicate. The use of this silicate can thus be generalized whether or not flexographic printing presses are used.

EXAMPLE 9 In this example, it is intended to use the washing waters of flexographic printing presses for the production of both the primary part or the support and the secondary part in the production of a two-surface adhesive by the Stein-Hall method.

As a result, a support or primary is prepared using water containing 4% orange and a mixture of 98% starch and 2% sodium silicate under the same conditions as in Example 7.

In other words, this "carrier" is obtained using - 450 l of the above-mentioned wash water, - 50 kg of said starch-silicate mixture, 8 kg of pure soda, under the conditions of Example 1 secondary to the amounts of - 700 l of said wash water, - 250 kg of said starch-silicate mixture, 6 kg of borax.

The viscosity of the resulting adhesive Lory is 19 seconds. The viscosity of Brookfield is 460 cp. The solidification point is 58 ° C. The latter therefore changes slightly. At the border could be repaired with soda (about 1 kg). In practice, however, it is often not necessary, as the conditions maintained are the most severe and in the industry 70038 π washing waters are less harmful and do not require repair of the solidification point.

EXAMPLE 10 An adhesive formula of the "no carrier" type or without a "support" is used here.

To prepare this glue, starch milk and soda solution are prepared with both preparations mixed so that the temperature of the mixture is 39 ° C, and in this case soda ash is 3.56% by weight of the commercially available starch.

Starch milk is obtained using 225 kg of starch and 706 liters of water.

In the first experiment, the product obtained with tap water is subjected to a soda effect time "x" sufficient to bring the viscosity measured with a Brabender viscograph to 300 Brabender units. This time "x" is measured.

In the second experiment, an adhesive is prepared using milk obtained from starch and water containing 4% of an "Orange 802" type flexographic dye. Measure the time "x".

In the third experiment, the milk needed to make the glue is made using 97% starch powder and 3% water containing module 2.06 sodium silicate and 4% flexographic dye. This milk is exposed to soda. Then another time "x" is measured.

The fourth experiment proceeds in the same way as the third, except that the water does not contain flexographic color. Measure the time "x".

The values of time "x" are summarized in Table IV.

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TABLE IV

Reaction time in soda "x" (300 UB)

First experiment (comparison) 22 minutes

The second test is not swelling

Third test 21 minutes

Fourth experiment 26 minutes Examining these results, it is found that the sensitivities to sodium in the first and third experiments are very close to each other. In other words, a good viscosity is obtained after the same times.

Sodium silicate makes it possible to correct the very harmful effect of the color, which in the second experiment prevents any swelling.

On the other hand, the fourth experiment states that, in the absence of color, sodium silicate in no way interferes with the composition of the product.

Measurements are restarted with an adhesive formula similar to that used in industry.

This formula is obtained with the following quantities and conditions:

- 225 kg of starch in 705 l of water, all placed at 36 ° C

temperature,

- 8 kg of soda ash in 215 liters of water at 54 ° C

to temperature - the two above solutions are mixed, the temperature then reaches 39 ° C.

Using these volumes, carry out four experiments similar to those above and fix the reaction time "x" for 20 minutes with 3.56% soda ash, adding 4.5 kg of boric acid. Measure the viscosities of Lory and Brookfield and the solidification point. for the adhesives thus obtained.

The results are shown in Table V.

TABLE V

Viscosity Viscosity Freezing point

Lory Brookfield (seconds) (centipoises) (° C)

First experiment (comparison) 10 780 50

The second test is not swelling is not performed

Third tissue 11 1 280 55

Fourth experiment 11.5 1,000 50.5

Examining the results in Table V, it is found that although sodium silicate slows down the expansion slightly in the presence of soda, the final viscosity, on the other hand, is slightly higher in the absence of color (Experiment 4).

In the presence of color (Experiment 3), the viscosity of Lory is very suitable. The structure of the glue is slightly shorter. The pour point is higher, but the expansion time is stabilized, which is considerable.

EXAMPLE 11

Perform the same experiments as in Example 1, ie: - first experiment (1): standard formula, - second experiment (2): the secondary water is replaced by water with 4% flexographic color type ROUGE 824 (brand MILL0RY), and - the third experiment (3): the starch is replaced by a mixture of 98% starch and 2% Portland cement.

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The results of the measurements performed are shown in Table VI.

TABLE VI

Viscosity Viscosity Freezing point

Lory Brookfield (seconds) (centipoises) (° C)

Experiment (1) 19 280 54

Test (2) does not measure 14 200 59

Experiment (3) 43 410 56.5

Cement appeared to be too inactive, but in general, the color mixtures contained in the water are less harmful than the colors considered above, and as a result, in practice, its use may be sufficient to neutralize the effect of industrial washing waters.

EXAMPLE 12

Perform the same experiments as in Example 1, i.e. - first experiment (1): standard formula - second experiment (2): the secondary water is replaced by water containing 4% flexographic color type ROUGE 824 (mark MILLORY) and - the third experiment (3 ): the starch is replaced by a mixture of 99% starch and 1% activated carbon as a powder (Societe CECA SA - 78140 Velizy-Villecoublay).

The results of the measurements performed are shown in Table VII.

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TABLE VII

Viscosity Viscosity Freezing point

Lory Brookfield (seconds) (centipoises) (° C)

Experiment (1) 19 280 54

Test (2) does not measure 14 200 59

Experiment (3) 43 550 57 The conclusions are the same as for cement. However, the effect is less obvious with respect to the pour point, and it may be necessary in normal industrial operation to correct the pour point by adding a small amount of alkali.

Thus, depending on the embodiment used, there is thus provided a method which allows the use of washing water for flexographic printing equipment in the manufacture of an adhesive for the manufacture of corrugated board, a method whose features and advantages are clearly apparent from the above.

As is clear and as will be apparent from the foregoing, the invention is in no way limited to the embodiments set forth in more detail herein but, on the contrary, includes all modifications.

Claims (6)

16 700 3 8 A method for producing color-tolerant starch adhesives, in particular starch adhesives for the production of corrugated board, using flexographic equipment washing waters, characterized in that either the starch for the production of these adhesives or the flexography equipment on the other hand, at least one substance from salts and oxides of Ca, Mg, Mn, Ni, Co, Cr, Fe or silicoaluminate, activated carbon, cement or silicates and optionally alkali metal hydroxide and the amount of this substance to be added, if not be silicate, being 0.01 to 10, preferably 0.05 to 5% by weight of the total amount of starch and substance to be added, and the amount of substance to be added, when it is silicate, is 0.01 to 49, preferably 0.05 to 20% by weight. -% of the total amount of starch and silicate. Process according to Claim 1, characterized in that the amount of silicate used is 0.01 to 10% by weight of the sum of the amount of starch and silicate used. 3. An additive which enables the use of flexographic printing press washings in the manufacture of color-tolerant starch adhesives, in particular starch adhesives for corrugated board, and which is intended to be added under normal pH conditions to either starch or wash water or to a carrier the substance is selected from the group consisting of salts and oxides of Ca, Mg, Mn, Ni, Co, Cr, Fe and silicoaluminates, activated carbon, cements and silicates and the amount of this substance to be added when it is not silicate is 0, 01-10, preferably 0.05-5% by weight of the total amount of starch and the substance to be added, and the amount of the substance to be added when it is silicate is 0.01-49, preferably 0.05-20% by weight of the total amount of starch and silicate in the order of. Use of starch, in particular in the manufacture of adhesives for the production of corrugated board, using washing water for flexographic equipment, which starch contains an effective amount of the substance according to claim 3. I? 70038 Use of starch according to Claim 4, characterized in that the starch contains a substance other than silicate in an amount of 0.01 to 10%, preferably 0.05 to 5% by weight, of the sum of the amount of starch and the substance. Use of starch according to claim 4, characterized in that the starch contains 0.01-49%, preferably 0.05-20% and even more preferably 0.1-6% of the sum of the amount of starch and silicate. 18 70038