DE1916931A1 - Use of copolymers as binders for printing inks - Google Patents

Description

REICHHOID-ALHEHT-CHEMIE AO, 2 Hamburg 13 $ Iversstrasse 57 Patent application Use of copolymers as binders for printing inks

The invention relates to the use of copolymers as Binder for printing inks, especially for toluene gravure printing.

Gravure printing inks consist of a dispersion of a pigment in the solution of a binder. They should have relatively low, constant viscosities. With the shortest possible Drying times they should produce a high gloss and good color strength of the prints «

A series of binders based on rosin fulfills these requirements World-wide requirements. Since a natural substance is used as the starting material which in its characteristics depends on the origin and the age Depending on the rosin used, the composition of these binders can sometimes vary. Another disadvantage of this The reason for resins is that they are always more or less colored and susceptible to oxidation.

On the other hand, oligomeric polystyrene is very soluble in toluene and dilutable. However, it has the disadvantage that it dries too slowly Pigment «poorly wetted and has a low melting point.

It has now been found that the aforementioned disadvantage can be · deal and quality gravure inks · comes This is possible in the invention by the use of copolymers of units of Maleinsäureanhydrld, 50 to 95 mole - misohpolyrnerlslerbaren% olefinically unsaturated monomers dl · where appropriate, a further " Telogen component "included,

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BATH ORIGINAL

the copolymers having an average molecular weight of 600 ble 3000 and the sum of the components is always 100 MoI-Jf than Binders for printing inks, in particular for toluene gravure printing. By The inventive use of these binders arises in comparison the also inexpensive printing ink resins based on rosin have the advantage that the printing inks made from them dry more quickly. Wet pigments better and show higher gloss. In addition, one can start from pure, chemically uniform, easily accessible monomers and, in one reaction stage, easy-to-characterize, light-colored binders are obtained.

Those copolymers which are considered to be olefinic are particularly suitable unsaturated monomers 60 to 75 mol of a vinyl aromatic compound the general formula

in which X and Y are hydrogen, chlorine, bromine or a methyl group. Such a copolymer can contain, for example, styrene and / or vinyl toluene units. In general, the copolymer can also contain cumene or cyraol as a telogen. Other suitable telogens are, for example, p-xylene or mixtures of ieomers of xylenes. The telogen content can make up to 20% by weight of the copolymer. It can vary depending on the molecular weight of the polymer and the chemical character of the telogen. So it is for example possible that copolymers having an average molecular weight of from about 6OO to 700 a telogen content of from about 15 to l8 Gewiohta-Ji, those having an average molecular weight of about 1000 to 15ΟΟ zn a telogen content of up to 5 weight ^. In general, one will have a higher proportion of telogen with a molecular weight and vice versa "

The copolymers suitable for the binders can »on

those on well-known ways, g.B. according to the Belgian Pateatsotoift "664 getting produced. In the case of interpolymerization, which is usually carried out at

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If reaction temperatures of over 150 ^° C. are carried out, the solvent is generally heated ^{to 170 to 220 ° C.} The olefinically unsaturated monomer, for example styrene, maleic anhydride and a peroxide, are then added as initiator. The copolymer formed is obtained by precipitation or distilling off the solvent. Examples of solvents that can be used are cumene, cymene, methyl ethyl ketone, the various xylenes, toluene or benzene.

Styrene-maleic anhydride copolymers are particularly useful for gravure printing inks suitable, of which solutions with 40 to 50 weight ^ solids content e.g. can be produced in toluene which can be diluted to at least a concentration of 25 to 30% by weight.

The viscosity of the 40 Jfigen mixed polymer solutions in toluene must be so low that you can achieve run times of 15 to 100 seconds in the Ford (DIN) cup no. 4 at room temperature. This is guaranteed if the average molecular weights of the copolymers in the invention Area lie. The mean molecular weights (number average) can be determined by isothermal distillation.

For gravure printing, only those copolymers are of interest that not only sufficient solubility and compatibility (dilutability) but at the same time release the solvent as quickly as possible. It is surprising that the rate of solvent release depends very much on the maleic anhydride content of the copolymers. The more maleic anhydride is incorporated, the faster the solvent is released again. There are therefore only maleic acid / anhydride copolymers with certain specified according to the invention medium molecular weight and with certain maleic anhydride proportions corresponding to the above-mentioned proportion of the olefinically unsaturated Monomers with a possible maximum telogen content of about 20 Weight percent suitable. If the copolymers are olefinic unsaturated monomers and the maleic anhydride in the molar ratio of ItI show those based on styrofoam derivatives, such as Vinyl toluene, better properties, e.g. better solubility than those based on styrene.

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Although styrene copolymers «especially with a very high styrene content, e.g., about 90 mole percent, are quite useful, products with lower styrene content become in some respects improved products obtain! e.g. the evaporation time for the solvent is reduced Reduction of the styrene content from 90, preferably to 75 to 60 mol percent, considerably shortened. Other vinylaromatic compounds, such as α-methylstyrene and vinyltoluene, also bring similar results olefinically unsaturated compounds e.g. esters, such as solohe made of acrylic or methacrylic acid, vinyl acetate, and olefins with up to 18 carbon atoms, in particular α-olefins, allyl compounds, such as allyl esters or ethers or similar.

The copolymers used in the printing ink binders dissolve generally in the heat quickly in toluene, with light-colored solutions being formed. These do not change their viscosity when standing and are insensitive to oxidation. The production of the printing ink can be done, for example, in a 20 to 50% solution of the copolymers in toluene Pigments finely dispersed in the usual way. surprisingly leave In spite of their high acid numbers, these solutions proved to be easy with the pigments, such as phthalocyanine blue or dispersed oil pigments, process into storage-stable mixtures, although this has so far often made difficulties with resins with higher acid numbers. It can additionally other solvents such as xylene or gasoline can also be used. the The pigment concentration can be 5 to 30 weight units of the binder.

example 1 Production of the styrene-MalelnsMureanhydrid-Mischpolyinerisaf

8 kg of xylene are placed in a 40! Autoclave and heated to 200.degree. A solution, heated to 40 ^° C., of 2.75 kg of maleic anhydride in 5 × 5 kg of styrene and a solution of 250 g of di-tert-butyl peroxide in 3 × 5 kg of xylene are then metered in as an activator in about 60 minutes. React for another 15 minutes and then distill off the xylene. 9.2 kg of styrene-maleic anhydride copolymer are obtained with a maleic anhydride equivalent of 346, an average molecular weight of about 1200 and a melting point of 106 ° C. (capillary method).

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Examples 2 to 6

Using the same procedure, styrene and maleic anhydride are made also copolymerized in other weight ratios. the Properties are summarized in Table 1.

Example 7

Using the same procedure as in Example 1, vinyl toluene and maleic anhydride ralach-polymerized.

Vergleloha attempt 8 (polystyrene)
Production of the oligoric polystyrene

500 ml of cumene are heated to 200 ° C. in an autoclave. A solution of 4 g of di-tert-butyl peroxide in 200 g of styrene is then pumped in over the course of 20 minutes. After the cumene has been distilled off, 210 g of oligomeric polystyrene remain.
Molecular weight 1740, melting point 90 ° C.

Comparative experiment 9 (phenolic resin)

Rosin, for example in the form of polymerized rosin, is condensed with an alkaline condensed phenol-formaldehyde resin based on diphenylolpropane and the resulting resin is then largely esterified with pentaerythritol. Melting point of the product 1 ^ 8 ⁰ C (capillary method), SXuresahl 20, Viskos! Tut (50 Jfige solution in toluene at 20 ° C) 250 to 350 cP, solubility in toluene as desired.

The overview of the resins used results from the following Table 1

Table 1 Styrene Vinyl- Π Malein Vinyl- • 65 Mole Enamel viscosity example toluene acid fade 72.5 weight point ^e C oP (Molecular anhydride manure 89 (Middle (Kaplllar- (50 % ToIu ratio) (MoI-Ji) 66.6 value) method) oil solution kg kg kg 66.6 20 · C) 5.5 2.75 1200 106 1200 1 (1.9 »1) 7.0 2.5 1400 106 156 2 (2.6 »1) IA .- 0.8} 2000 87 56 3 (7.9H) 2.0 2.3 2.0 1300 121 975 * (0.95l0.97 »l) 3.0 1.15 2.0 1250 120 615 3 (1.3 to 5 H) no «*? /? / 6
BATH ORIGINAL

Table 1. (continued) example

(Molecular ratio)

Styrene

Vinyl toluene

kg

Malein-

acid·*

anhydride

kg

Vinyl compound
(MoI-Jl)

Molecular weight (mean)

Melting point * C (capillary method)

Viscosity cP

(50 % toluene solution "20 ⁰ C)

6 (4.8 * 1))

8 polystyrene (comparison)

9 phenolic resin (comparison)

5.0

3.55

1.0
3 83
60 1800
1100 106
92 142
1700 - - 17 ^ 0 90 - 2000 138 250-350

Manufacture of toluene printing inks

In each case 100 g of samples 1 to 9 are dissolved in 100 g of toluene. This solution is in a ball mill with 20 g of a red pigment (Pigment Red 53 paint red toner LClL 20) homogenized for 30 minutes. The color dispersion becomes with further Toluene adjusted to an outflow time of 17 to 20 seconds (DSf 4 cup).

Printing test

In order to demonstrate the particular advantages of the claimed binders, were the solids content, the non-tackiness as a measure of the speed of the Dissolving agent delivery and the amount of oil produced from these binders Gravure printing inks compared to an oligomeric polystyrene and a natural resin modified one Measured phenolic resin.

The printing inks are all coated with a drawing spiral in a respective Neö-Schiohtdicke of 36 Ai on machine-coated paper (weight of A4 sheet 5.4 g). The absence of glue in seconds is determined by manual touching. It is determined by the time span in seconds from the drawing up of the print colors to the point in time when they are tack-free when touched. For the oil test according to position, colored layers of the same visual strength are also used. The solids content of the printing inks (resin and pigment) is determined by simple RUoketes «3 determination for 30 minutes at 150 ° C. The results are compiled in the table below.

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Table 2 Tack-free Shine after Feetoffstoff rehearse Seconds location Weight? 64 30th 41.6 1 95 30th 43.4 2 102 32 46 3 86 24 42.1 4th 73 25th 41.8 5 97 30th 43.3 6th 68 28 40.4 7th 260 32 46.2 8 (comparison) 105 29 40 9 (comparison)

The values shown in Table 2 show a good gloss and the faster release of solvents from printing inks based on styrene-maleic anhydride copolymers. The products thus meet the requirements of the printing ink industry for printing inks as closely as possible short ventilation times, i.e. the fastest possible release of solvent, with high gloss at the same time.

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Claims (6)

Paten ta na ρ r U c h β 1. Use of copolymers made from units of maleic anhydride, 50 to 95 MoI-Ji polymerizable, olefinically unsaturated Monomers, which optionally contain a telogen component contain, the copolymers have an average molecular weight of 600 to 3OOO and the sum of the components always 100 · MoI-Ji as a binder for printing inks, in particular for tologravure printing. 2. Use according to claim 1, characterized in that the olefinic unsaturated monomers a vinylaromatic ^ compound the formula \ S - CH - CH ₂ is where X and Y are hydrogen, chlorine, bromine or a methyl group mean. 3. Use according to claim 1 or 2, characterized in that the olefinically unsaturated monomers styrene and / or vinyl toluene units contain. 4. Use naoh claims 1 to }, characterized in that the copolymer contains 60 to 75 mol of olefinically unsaturated monomers. 5. Use naoh claims 1 bie h, characterized in that the copolymer has an average molecular weight of 800 to 2000. BATH ORIGINAL 009852/2037 6. Use according to claims 1 to 5 «characterized in that that the copolymer still contains cumene as telogen. J, use according to claims 1 to 6, characterized in that the binder is present as a mixture with 5 to } 0 % by weight of pigments. 2k. March 1969
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