ES2581884T3 - Wetting agent - Google Patents

Abstract

Wetting agent or wetting agent concentrate comprising at least * at least one pH value regulator * at least one N-alkyl guanidine salt comprising the wetting agents obligatorily, and the wetting agent concentrates where appropriate, also * water characterized because as n-alkyl guanidine salt, n-dodecyl guanidine acetate or ndodecyl guanidine chloride are used.

Description

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DESCRIPTION

Wetting agent

The subject of the present application are wetting agents with biocides and their concentrates, as used, for example, for offset printing.

In offset printing, a printing plate is used, which essentially has no height differences. Rather, the image and non-image areas of an offset printing plate have different wetting properties, that is, hydrophobic and hydrophilic zones. An offset printing plate usually comprises a support, which is provided with a suitable hydrophobic coating. In areas without an image, the photosensitive layer is removed, so that the hydrophilic layer support is exposed. The hydrophobic areas of the printing plate can be moistened with ink, the hydrophilic zones, correspondingly not. Other details in regard to offset printing technique, for example, come from the Rompp Encyclopedia "Lacke und Druckfarben" (paints and printing inks), Georg Thieme publishing house, Stuttgart, New York 1998, pp. 167 to 170.

For example, an offset printing plate is held on the printing cylinder, for example. The pressure cylinder is touched by two other rollers, the so-called ink roller and the so-called wetting roller.

By means of the ink roller, the printing ink is transferred to the printing plate, and by means of the wetting roller the so-called wetting agent is applied on the surface of the plate. In the case of wetting agents, it is usually a composition consisting essentially of water and additives.

The wetting agent has the task of generating on the non-printing parts of the printing plate, a stable moisture film, which prevents the absorption of offset printing ink in these parts of the printing press. In this case it is irrelevant if, when wetting agent and ink are applied on the pressure plate during each rotation of the plate cylinder, the wetting agent is first applied and then the ink, or if this is carried out in reverse order. From the printing cylinder the ink applied in accordance with the image is usually printed first on the so-called rubber blanket cylinder and from there on the paper.

From the wetting roller, the wetting agent is transferred to both the printing and non-printing areas of the printing plate. The amount of wetting agent transferred can be controlled, for example, through the speed of the addition roller in the wetting system. In areas of non-printing, the wetting agent is responsible for the hydrophilization of the areas. In the printing zones, a water-ink emulsion is formed from the wetting agent and the printing ink.

It is advantageous and usual to prepare the wetting medium ready to use immediately before use in offset printing, from corresponding concentrates of wetting agent and water.

Wetting agent concentrates are usually concentrated aqueous solutions, but eventually also solid, powdered, lozenge or paste products, which contain the necessary additives for the wetting agent in offset printing. From these concentrates, the wetting agents are ready for use by dilution with or dissolving the concentrates in water.

This type of wetting agents can be affected during storage and use in the printing machine, by microorganisms such as bacteria, mold, yeasts and algae, and due to this end up having a shape that is no longer suitable for use. The microbiological deterioration of wetting agents is noted, for example, by bad smell, changes in pH, decoloration, precipitation, increased corrosivity and the like, effects that reduce the quality of the products. Proper use of these products is no longer possible, with the consequence that they must be disposed of properly. If the microbiological decomposition occurs when the wetting agent is used in the printing press, process disturbances and thereby downtimes can occur.

Consequently, no attempts to reduce the microbiological vulnerability of wetting agents through the use of biocides have been lacking. In this way it is known to add to the wetting agents for example, formaldehyde dissociation compounds. These effective biocides themselves are no longer desirable however in practice, due to toxicological reasons.

Another widely used group of substances is isothiazolinones, particularly the 3: 1 mixture of chloromethylisothiazolinones and methylisothiazolinone (CMIT / MIT). Despite the good efficacy of this group of substances, the use is controversial due to the sensitizing properties of isothiazolinones. All known preservative agents therefore have, according to experience, that although they have a certain protective effect, they nevertheless have negative characteristics in a practical application.

JP 2959663 B discloses a wetting agent containing a biguanidine salt.

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There was therefore a particular need in the printing industry for microbiologically stable wetting agents for offset printing, which can overcome the disadvantages of the prior art.

Surprisingly, it has now been discovered that wetting agents of known composition themselves no longer exhibit virtually no microbiological attack, when as N-alkyl guanidine salt they have n-dodecyl guanidine acetate or n-dodecyl guanidine chloride. In this case, it is surprising that amounts of 1000 ppm or less in ready-to-use wetting agents are already sufficient to achieve the good protection effect.

The salts of N-alkyl guanidine are known for example from US 6,890,969, in which they are described for the stabilization of polymer emulsions.

The subject of the invention are therefore wetting agents and wetting agent concentrates that contain at least one N-alkyl guanidine salt which is an n-dodecyl guanidine acetate or n-dodecyl guanidine chloride.

The framework of the invention also includes the preferred fields and fields of formulas and parameters, also any combinations of these, even when they are not fully explicitly explained due to practical reasons hereafter.

Compounds of N-alkyl guanidine are generally understood as compounds, which have at least one guanidine group or biguanidine group, which have at least one of their nitrogen atoms, an alkyl radical, or compounds in which they are linked respectively two groups selected from guanidine groups and biguanidine groups through at least one of their nitrogen atoms respectively through an alkyl radical. Examples of compounds of the latter type comprise chlorhexidine and polyhexanide.

The salts of N-alkyl guanidine are generally those of the formula (I)

[H2N- (C = NH2) -NH-R] + X- (I)

wherein R represents a C8-C18 alkyl radical and X- a monovalent anion or 1 / p equivalents of a potential anion, representing p a natural number of 2 or more.

R represents according to the n-dodecil invention.

X- represents according to the invention acetate or chloride.

Compounds of the formula (I) used according to the invention are n-dodecyl guanidine acetate and n-dodecyl guanidine chloride.

The concentration of use of these compounds in the wetting agents ready for use, depends on the type and appearance of the microorganisms to be fought, on the microbial starting load, for example, on the water normally used for diluting agent concentrates. humectant, as well as after the composition of the wetting agent to be protected. The optimum amount of use can be determined in a simple way known sufficiently by the expert before being put into practice by a series of tests in the laboratory.

In the ready-to-use wetting agents, for example from 10 to 5000, preferably from 50 to 2000, particularly preferably from 100 to 1500 and very particularly preferably from 100 to 1000 ppm of N-alkyl guanidine salts are used.

The wetting agents according to the invention contain at least:

• Water

• at least one pH value regulator

• at least one N-alkyl guanidine salt, as defined in claim 1.

The water content in the wetting agents ready for use is, for example, 95.0 to 99.7% by weight, preferably 98.0 to 99.7% by weight. The rest up to 100.0% by weight, is made up of the N-alkyl guanidine salts, the pH regulators, as well as the substances optionally added additionally.

Additives or mixtures of additives are understood as pH value regulators, with the help of which the desired pH value can be adjusted.

Ready-to-use wetting agents preferably have a pH value under standard conditions, from 3 to 9, preferably from 3.0 to 6.0, and particularly preferably from 4.0 to 5.5.

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The pH value regulators comprise for example buffer substances or buffer systems, or depending on the desired pH value also acids and bases.

Preferred acids are phosphoric acid or organic acids, such as, for example, citric acid, ascorbic acid, sulfamyl acid, tartaric acid, lactic acid and acetic acid, citric acid being preferred due to its buffering capacity.

With the aforementioned acids, the corresponding alkaline salts of these acids, particularly preferably, the sodium, potassium and lithium salts, or corresponding bases, which neutralize a part of the acid, can preferably be used for the formation of buffer systems.

The wetting agents according to the invention may also or may comprise respectively:

• hydrophilic film-forming substances, such as gum arabic, tragacanth gum, carboxymethyl cellulose, alginates, such as sodium alginate, cellulose derivatives, such as carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, methyl cellulose, carboxymethyl starch, methyl cellulose, polyvinyl pyrrol poly alcohol.

• Substances with surfactant properties, such as surfactants. The surfactants may be, for example, nonionic, cationic and amphoteric surfactants, preferably anionic surfactants. Suitable anionic surfactants are, for example, alkyl sulfates, ether alkyl sulfates, alkylaryl sulphonates, alkyl succinates, alkyl sulphosuccinates, N-alkylsarcosinates, acyl restaurants, acylisethionates, alkyl phosphates, alkyl ether phosphates, alkylethercarboxylates, alpha-olefin sulfonates, particularly alkali and alkaline earth metal salts, for example, sodium, potassium, magnesium, calcium, as well as ammonium and triethanolamine salts. The alkyl ether sulfates, ether alkyl phosphates and alkylethercarboxylates may respectively have, for example, between 1 and 10 units of ethylene oxide or propylene oxide, preferably 1 to 3 units of ethylene oxide. Suitable are, for example, sodium lauryl sulfate, ammonium lauryl sulfate, sodium lauryl ether sulfate, sodium lauryl ether sulfate, sodium lauryl sarcosinate, sodium oleyl succinate, sodium lauryl sulphosuccinate, sodium dodecylbenzenesulfonate, triethanolamine dodecylbenzene sulfonate .

• Wetting media, such as alkaline, alkaline earth salts, ammonium salts of aromatic sulfonic acids, for example, lignin, phenolic acid, naphthalene and dibutylnaphthalenesulfonic acid, as well as fatty acids, alkyl- and alkylarylsulfonates, alkyl sulfates , of lauryl ether and fatty alcohol, as well as salts of sulfated hexadecanoles, heptadecanoles and octadecanoles or fatty alcohol glycol ethers, condensation products of sulfonated naphthalene and its derivatives with formaldehyde, condensation products of naphthalene or sulfonated naphthalene acids with phenol and formaldehyde, octylphenol polyoxyethylene ether, alkylphenol or tributylphenyl polyglycol ether, polyaryl alkylaryl alcohols, isotridecyl alcohol, fatty alcohol ethylene oxide condensates, ethoxylated castor oil, polyoxyethylene or polyoxypropylene alkyl ether of lauryl alcohol polyglycol, sorbitol esters, sulfur residual liquors lignin or methylcellulose.

• Organic solvents, such as mono or polyvalent alcohols, alcohol ethers and ketones. Examples of suitable solvents are methanol, ethanol, isopropanol, ethylene glycol, glycerin, sorbitol, hexitol, propylene glycol or polyethylene and propylene glycols, butylene glycol, neopentyl glycol, 2-ethyl-1,3-hexanediol and 1,6-hexanediol .

• Softening agents such as complexing agents, such as EDTA.

• Antifoaming agents to reduce the formation of foam induced by surfactants or other substances.

• Corrosion inhibitors.

• Drying accelerators for drying printing ink.

The wetting agents according to the invention may additionally comprise as additional biocides, or none, one or more active ingredients. These additional biocides may be chosen, for example, from the group consisting of bronopol, benzylhemiformal, trimethylene-2-methylisothiazolinone-3-one, N-methyl-benzisothiazolinone, 2-n-octylisothiazolin-3-one, tetramethylacetylene diurea (TMAD), 1,3-bis (hydroxymethyl) -5,5-dimethylimidazolidine-2,4-dione (DMDMH), p-chloro-m-cresol, dimethylol urea, 1,2-dibromo-2,4-dicyanobutane, 2,2 -dibromo-3-amide of propionic nitrile acid, glutardialdehyde, ethylene glycol-hemiformal, sodium pyrithione, 2-phenoxyethanol, phenoxypropanol, o-phenyl phenol, chlorophen, and quaternary ammonium salts, such as N-alkyl-N, N-dimethyl benzyl ammonium chloride.

The wetting agents according to the invention are characterized by high microbial stability, which can avoid the aforementioned drawbacks.

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It is also the object of the invention, therefore, a method to avoid chemical decompositions of product or process interruptions caused by microorganisms in offset printers, by using the wetting agents according to the invention, as defined in claim 10. They are particularly effective against bacteria, fungi, yeasts or mucous organisms. As an example, the following microorganisms are named:

- Bacteria: Alcaligenes, such as Alcaligenes faecalis, Bacillus, such as Bacillus subtilis, Citrobacter, such as Citrobacter freundii, Corynebacter, such as Corynebacterium ammoniagenes, Enterobacter, as Enterobacter aerogenes, Enterococcus, as Enterococcus hirae, Escherus colius, Escherus colius, Escherus coli, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus colius, Escherus coli, Escherus colius , Pseudomonas, such as Pseudomonas aeruginosa, Pseudomonas fluorescens or Pseudomonas stutzeri, Salmonella, such as Salmonella enterica, Staphylococcus, such as Staphylococcus aureus;

- Fungi: Acremonium, such as Acremonium strictum, Alternaria, such as Alternaria tenuis, Aspergillus, as Aspergillus niger, Chaetomium, as Chaetomium balloonsum, Fusarium, as Fusarium solani, Geotrichum, as Geotrichum candidum, Lentinus, as Lentinic tigrinus, Penicumium, Penis or Penicillium pinophilum;

- Yeasts: Candida, as Candida albicans, Rhodotorula as Rhodotorula rubra, Yarrowia, as Yarrowia lipolytica;

Also subject to the invention are concentrates of the wetting agent as defined in claim 9, from which the wetting agents ready for use can be obtained by the addition of water, and as a consequence they may contain the same components or not, as have been described above for ready-to-use wetting agents.

The formulation of the wetting agent concentrates according to the invention is any, and can be carried out, for example, in the form of solutions, pastes, granules or tablets.

Due to the locally different and often variant water qualities for industrial use and their influences that are difficult to calculate according to the experience through the wetting agents in the printing result, it is advisable to use treated, preferably demineralized water for the preparation of the wetting agents. or water with a total hardness of 2.14 mmol / at least, such as 1.42 to 2.14 mmol / l.

The necessary amounts of N-alkyl guanidine salts for microbiological stabilization, as well as possibly other biocides, can be added to the wetting agents of usual composition also directly before use in the printing process. Because of this, the invention also comprises the use of N-alkyl guanidine salts for the production of wetting agents as defined in claim 11 particularly for offset printing.

The good efficacy of the N-alkyl guanidine salts used according to the invention for the protection of wetting agents ready for use is documented in the following example.

Example

Microbiological load test

With a microbiological load test, the vulnerability of water-based systems to microbial contamination and the effect of preservative agents was verified. For this, the preservatives were incorporated in defined concentrations in the wetting agents ready for use. After that, a contamination with microorganisms respectively per week was introduced during a 6-week test period, as indicated below at weekly intervals, so that after each contamination approximately 106-107 bacteria are included per / g and 104- 106 mold or yeast cells per / g. 7 days after each contamination, it was determined by microbial count, if there was a complete destruction (= 0 bacteria or mold or yeast cells per / g) or at least the inhibition of the reproduction of the microorganisms introduced in comparison with the samples of control not preserved.

As a water-based system, a wetting agent concentrate with the following composition was used:

10% by weight glycerin

7.5% by weight citric acid

2% by weight of sodium hydroxide

2% by weight of arabic gum

5% by weight of isopropanol

Rest up to 100% by weight of water

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The amounts of n-dodecyl guanidine hydrochloride (DGH) (commercial solution of DGH with 35% by weight of active agent content diluted in a mixture were added to the ready-to-use wetting agent (2.5% aqueous dilution) of dipropylene glycol / propylene glycol, N-2000 LANXESS Antimicrobial, for example, 0.1% by weight of N-2000 Antimicrobial for 350 ppm DGH), indicated in Table 1.

As microorganisms, the following types of mixed microorganisms were used for testing:

Bacteria: Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus,

Molds: Acremonium strictum, Aspergillus niger, Geotrichum candidum,

Yeasts: Candida albicans, Rhodotorula rubra.

Very good efficiency is achieved when the preserved samples result in complete destruction (0 bacteria or mold or yeast cells per / g) of the introduced microorganisms (grade 3 = very good).

A good effect occurs when compared to the unconserved sample, a strongly reduced level of microbes is observed (at 103-101 bacteria or at 102-101 mold or yeast cells per g) (rating 2 = good).

A moderate effect occurs when compared to the unconserved sample, a slightly reduced level of microbes is observed (at 104-103 bacteria or at 103-102 mold or yeast cells per / g) (rating 1 = moderate).

An insufficient effect occurs when compared to the unconserved sample, no or only a minimal reduction in the level of microbes is observed (at a residual level of at least 105 bacteria or 104 mold or yeast cells per / g) ( rating 0 = insufficient).

The results obtained are indicated in table 1.

Table 1: efficacy of biocides, determined respectively one week after germ addition

 Addition of biocide

   Week Week Week Week Week Week

 1 2 3 4 5 6

 + 0.10% by weight of N-2000

 B 3 3 3 3 3 3

 Antimicrobial

 S 3 3 3 3 3 3

 = 350 ppm DGH

 H 3 3 3 3 3 3

 + 0.20% by weight of N-2000

 B 3 3 3 3 3 3

 Antimicrobial

 S 3 3 3 3 3 3

 = 700 ppm DGH

 H 3 3 3 3 3 3

 + 0.30% by weight of N-2000

 B 3 3 3 3 3 3

 Antimicrobial

 S 3 3 3 3 3 3

 = 1050 ppm DGH

 H 3 3 3 3 3 3

 B = Bacteria S = Molds H = Yeasts

As can be seen in the table above, by adding only 350 ppm of DGH or 0.1% by weight of N-2000 Antimicrobial, a microbiologically stable wetting agent can be obtained, which also resists several cycles of massive contamination.

Claims (12)

5 10 fifteen twenty 25 30 35 40 Four. Five fifty 55 60 65 1. Wetting agent or wetting agent concentrate comprising at least • at least one pH value regulator • at least one N-alkyl guanidine salt the wetting agents necessarily comprising, and the wetting agent concentrates, if necessary, also • Water characterized in that as n-alkyl guanidine salt, n-dodecyl guanidine acetate or n-dodecyl guanidine chloride are used. 2. Wetting agent or wetting agent concentrate according to claim 1, characterized in that buffer substances, buffer systems, acids or bases are used as regulators of the pH value. 3. Wetting agent or wetting agent concentrate according to one of claims 1 to 2, characterized in that in all conceivable permutations they respectively comprise or do not respectively include: • at least one hydrophilic film-forming substance • at least one substance with surfactant properties • at least one wetting agent • at least one organic solvent • at least one softening agent • at least one antifoam agent • at least one corrosion inhibitor • at least one drying accelerator 4. Wetting agent or wetting agent concentrate according to one of claims 1 to 3, characterized by comprising respectively: • at least one hydrophilic film-forming substance • at least one organic solvent 5. Wetting agent or wetting agent concentrate according to one of claims 1 to 4, characterized in that they additionally either comprise none or comprise one or more biocides, which are preferably chosen from the group consisting of bronopol, benzylhemiformal, trimethylene-2-methylisothiazolinone-3-one, N-methyl-benzisothiazolinone, 2-n-octylisothiazolin- 3-one, tetramethylacetylene diurea (TMAD), 1,3-bis (hydroxymethyl) -5,5-dimethylimidazolidine-2,4-dione (DMDMH), p-chloro-m-cresol, dimethylol urea, 1,2-dibromo -2,4-dicyanobutane, 2,2-dibromo-3-amide of propionic nitrile acid, glutardialdehyde, ethylene glycol-hemiformal, sodium pyrithione, 2- phenoxyethanol, phenoxypropanol, o-phenyl phenol, chlorophen, and quaternary ammonium salts. 6. Wetting agents according to one of claims 1 to 5, characterized in that they comprise from 10 to 5000, preferably from 50 to 2000, particularly preferably from 10 to 1500 and very particularly preferably from 100 to 1000 ppm of salts of N-alkyl guanidine. 7. Wetting agents according to one of claims 1 to 6, characterized in that the water content is from 95.0 to 99.7% by weight, preferably from 98.0 to 99.7% by weight. 8. Wetting agents according to one of claims 1 to 7, characterized in that the pH value under standard conditions is 3 to 9, preferably 3.0 to 6.0 and particularly preferably 4.0 to 5, 5. 9. Wetting agent concentrate, from which the wetting agents according to one of claims 1 to 8 can be obtained by dilution with water. 10. Procedure for the prevention or reduction of product decomposition or process interruptions caused by microorganisms in offset printers, characterized in that as wetting agents those according to claims 1 to 8 are used. 11. Use of N-alkyl guanidine salts for the production of wetting agents or concentrates of wetting agents, particularly for offset printing, characterized in that n-dodecyl guanidine acetate or n-chloride are used as the N-alkyl guanidine salt. -dodecil guanidine. 12. Use according to claim 11, characterized in that the wetting agents are those according to one of claims 1 to 8, and the wetting agent concentrates, those according to one of claims 1 to 5.