EP1861464A2

EP1861464A2 - Aqueous suspensions or dispersions of inorganic pigments containing a mixture consisting of dialdehydes and formaldehyde cleavers

Info

Publication number: EP1861464A2
Application number: EP06723601A
Authority: EP
Inventors: Willem Anker; Marc Hombeck; Louise Sander Hansen
Original assignee: Bode Chemie GmbH and Co KG
Current assignee: ISP Investments LLC
Priority date: 2005-03-21
Filing date: 2006-03-21
Publication date: 2007-12-05
Also published as: CA2606594A1; NO20075357L; DE102005013695A1; WO2006100042A3; WO2006100042A2; US20090088483A1

Abstract

The invention relates to aqueous suspensions or dispersions (slurries) of minerals and/or fillers and/or pigments containing one or more dialdehydes and one or more formaldehyde cleavers, and to the use of mixtures consisting of one or more dialdehydes and of one or more formaldehyde cleavers for stabilizing aqueous suspensions or dispersions of minerals and/or fillers and/or pigments (slurries) with regard to infestation or deterioration by microorganisms.

Description

BEIERSDORF AG Hamburg

Aqueous suspensions or dispersions of inorganic pigments containing a mixture of dialdehydes and Formaldehydabspaltem

description

The present invention relates to aqueous suspensions or dispersions (= "slurries") of minerals and / or fillers and / or pigments containing one or more dialdehydes and one or more formaldehyde releasers and the use of mixtures of one or more dialdehydes and one or more Formaldehydabspaltem for stabilizing aqueous suspensions or dispersions of minerals and / or fillers and / or pigments ("slurries") against infestation or spoilage by microorganisms.

For the paper and board industry, a considerable number of pigments are available both as fillers and for surface treatment ("coating pigments"), by far the greater part of natural origin, formed by inorganic processes and physically and chemically homogeneous as minerals However, organic products can also be used as "coating pigments", eg Plastic pigments.

Depending on the requirements and economy different pigments are used, such as natural calcium carbonate (Ground Calcium Carbonate = GCC), precipitated calcium carbonate (Precipitated Calcium Carbonate = PCC), kaolin, talc, titanium dioxide and aluminum hydroxide, in some special cases also satin white.

Coating pigments for the surface finishing of paper and board have established themselves as one of the most important raw materials in addition to fibrous materials and fillers over the past 25 years. The permanent development activity of various branches of industry leads to a significant increase in the pigment content of coated varieties, whereby the fiber content can be reduced.

Very high solids (68-73%) high-solids coating ("High Solids") paint results in the highest levels of gloss and print gloss while achieving high levels of paper whiteness and optimum printability in offset printing Carton sector is the use of high-white calcium carbonate (CaCO ₃ ) in the meantime widespread.

From the individual recipe examples for offset papers and boxes, it is clear that it is necessary to distinguish for which type of paper the coating colors must be designed. For matt papers a distinction is made between single, double and triple strokes, in the latter for high-weight grades up to about 300 g / m ² . CaCO ₃ is increasingly being used as a coating pigment by up to 100%, with various papers and cardboard boxes containing approx. 10 - 20% talc or kaolin, especially in the top coat, for joint use. The fineness of CaCO ₃ for matt qualities is usually 60-75% <2 μm. In glossy qualities, which are also manufactured with single, double or triple strokes, coarser CaCO ₃ qualities can be found in the precoat. In single and top coats the fineness of the CaCO _{3 is} already in the range of 90 - 98% <2 μm.

Calcium carbonate slurries (suspension / dispersion) are by nature alkaline (pH 8-10) and are used worldwide in many millions of tonnes per year as a filler and / or as a coating pigment in the paper and board industry.

The production of the Ca CO ₃ -SI Urries performed either by wet milling of marble / chalk / limestone (this is called quality GCC = ground calcium carbonate), or by reaction of lime water with CO ₂ (this is called quality PCC: Precipitated calcium carbonates). Depending on the manufacturing process and the pigment hardness arise during the production of increased Slurrytemperaturen, these can 45 - 9O ⁰ C amount. Due to the large production volumes and the associated energy-intensive cooling processes, the slurries are not completely cooled down (also for cost reasons). Thereby lie in the storage tank of the finished slurry also often temperatures 35-65 ⁰ C before. Under the generic term calcite, the natural calcium carbonate occurs as chalk, limestone and marble. Chalk is a weakly consolidated sedimentary rock with limited whiteness. Limestone, on the other hand, is already more strongly solidified and whiter than chalk. Marble is a metamorphic carbonate rock formed by the chemical recrystallization of chalk or kaolin under high pressure and high temperature.

With marble, the highest whiteness among the natural carbonates can be achieved. For this purpose, the GCC is processed in different ways depending on the use, e.g. Dry milling and especially wet grinding are used for different purposes. For the paper and board industry, wet grinding has become popular, as it enables the highest levels of fineness to be achieved with targeted grain distribution curves. With solids contents of up to nearly 80%, these slurries are delivered directly to the manufacturers of paper and board.

The GCC quality is mostly produced near the limestone source, not necessarily near the paper mill. The delivery to the paper or cardboard factories takes place by means of railways, road tankers or ships. Additional storage facilities, near the paper mills, will ensure shorter-term deliveries.

PCC quality is often produced in a factory directly next to a paper mill and pipelined directly from the slurry manufacturer's storage tank to the paper process. Here very short residence times of the slurry can occur in the storage tank (6 - 12 hours), before it is used. On the other hand, other slurry qualities can also be stored much longer in the tank until it is used (1 - 21 days). Deliveries to other, distant paper mills can also take place.

Slurries in general and calcium carbonate slurries in particular are very susceptible to microorganisms.

A well-known preservative is glutaraldehyde (GDA). GDA is stable only in the acidic pH range (pH 3-5). In the alkaline pH range, the stability decreases very rapidly. This is significantly accelerated by temperatures> 30 ° C. GDA is able to remediate a germinated (alkaline) slurry within 1 to 4 hours. However, GDA offers no long-term protection, because after a few days, the drug GDA is completely degraded in the slurry.

It was therefore an object of the present invention to provide slurries which can be sterilized in a short time, but which also ensure sterility over a longer waiting period until further processing.

This object is achieved according to the invention by aqueous suspensions or dispersions of minerals and / or fillers and / or pigments ("slurries") containing

- one or more dialdehydes

- one or more Formaldehydabspalter.

Advantageous dialdehydes are glutaric dialdehyde (GDA), orthophthalaldehyde (OPA) and glyoxal.

Preparations according to the invention are distinguished by high long-term stability against infestation of microorganisms.

The invention therefore also relates to the use of mixtures of one or more dialdehydes and one or more formaldehyde releasers for stabilizing aqueous suspensions or dispersions of minerals and / or fillers and / or pigments ("slurries") against infestation or spoilage by microorganisms.

The concentration of one or more dialdehydes in the aqueous suspensions or dispersions according to the invention can advantageously be in the range from 0.0001 to 5.0% by weight, preferably from 0.0005 to 1.0% by weight, particularly preferably 0.001-0 , 5 wt .-%, based on the total weight of the product to be protected.

Formaldehyde releasers such as (ethylenedioxy) dimethanol (also called EDDM or O-formaldehyde) are stable in the alkaline pH range (7-10). Also elevated temperatures (50-80 ⁰ C) make no significant drug drop over a time frame of a few days away (the slurry is cooled slowly after production; the storage tank volume can easily 300-1000 tonnes and more be). Formaldehyde scavengers are used when you need a microbicide that is less volatile, less odorous, and more stable than formaldehyde. The first step towards these substances is the introduction of the hydroxymethyl group into molecules with active hydrogen atoms that can react with formaldehyde. Such molecules can be found in a wide variety of classes, from water to amino acids.

The hydroxymethyl compounds obtained in this way. can continue to react intra- and intermolecularly with elimination of water, so that an enormous variety of formaldehyde-decomposers with different chemical-physical properties are available. Among these are low-odor solids or liquids, water-soluble and oil-soluble substances, active substances that are alkaline, neutral or slightly acidic. Many of these substances have in common that they contain formaldehyde in bound form, but at the same time in available form for the antimicrobial effect, so that they are useful as electrophile-active ingredients.

As a rule, formaldehyde releasers are antimicrobially active if their formaldehyde content in aqueous solution can be determined by the method described by Tannenbaum and Bricker (reaction of the liberated formaldehyde with phenylhydrazine and potassium hexacyanoferrate).

With the help of the Formaldehydabspalter the formaldehyde as a microbicide areas of application are developed, which otherwise remained closed because of its unfavorable properties. The antimicrobial formaldehyde releasers can be divided into the following important main classes: hemiformal (O-hydroxymethyl compounds), C-hydroxymethyl compounds, amine-formaldehyde addition and condensation products, amide-formaldehyde addition products.

1, 3-bis (hydroxymethyl) urea, (ethylenedioxy) dimethanol, 2,2 ', 2 "- (hexahydro-1,3,5-triazine-1,3,5-), which are to be used advantageously in the context of the present invention, are tri-hyl) triethanol, tetrahydro-1,3,4,6-tetrakis (hydroxymethyl) imidazo [4,5-d] imidazole-2,5- (1H, 3H) -dione, α, α ', α "-trimethyl- 1 _I 3,5-triazine-1,3,5 (2H, 4H, 6H) -triethanol, 3,3'-methylene-bis- [5-methyloxazolidine] / oxazolidine, reaction products of N, N'-bis (hydroxymethyl ) urea with 2- (2-butoxyethoxy) ethanol, ethylene glycol and formaldehyde, (benzyloxy) methanol, 4.4- Dimethyloxazolidine, 7a-ethyldihydro-1H, 3H, 5H-oxazolo [3,4-c] oxazole, sodium N- (hydroxymethyl) glycinate, 1,3-bis (hydroxymethyl) -5,5-dimethylimidazolidine-2 , 4-dione, reaction products of ethylene glycol and formaldehyde, reaction products of tetrahydroimidazo [4,5-d] imidazole-2,5 (1H, 3H) -dione and formaldehyde, 1- [1,3-bis (hydroxymethyl) -2, 5-dioxoimidazolidin-4-yl] -1,3-bis (hydroxymethyl) urea / diazolidinyl urea, cis-1- (3-chloroallyl) -3,5,7-triaza-1-azonia-adamantan chloride, Dazomet.

Preferred formaldehyde releaser in the context of the present invention is the (ethylenedioxy) dimethanol (EDDM).

Advantageously, the concentration of one or more Formaldehydabspaltern in the aqueous suspensions or dispersions of the invention from the range of 0.0001 to 5.0 wt .-%, preferably 0.001 to 1.0 wt .-%, particularly preferably 0.005 - 0.5 % By weight, based on the total weight of the product to be protected.

The weight ratios of dialdehyde to formaldehyde releasers can advantageously be selected from the range from 50: 1 to 1: 1000, preferably from 10: 1 to 1: 100, particularly preferably from 5: 1 to 1:20.

Through the combined addition of GDA and EDDM, a pigment slurry can now be delivered in a germ-free / germ-free manner at room temperature or at elevated temperatures very quickly (= rapid action of the biocide), as well as for longer periods of time.

In addition, it has been found that this combination works significantly better than the individual substances, even in higher concentrations.

As is known to the person skilled in the art, the majority of customary slurries, generally between 25 and 80% by weight of very finely ground or divided pigment material, namely of the abovementioned inorganic pigments, are preferably calcium carbonate according to the invention. The particle size is advantageously adjusted so that about 50-90% of the particles have a particle size <2 microns. It is advantageous to incorporate other conventional ingredients in the slurry. Of these, mention should be made of dispersants whose purpose is to keep the dispersed particles in suspension. The dispersant is advantageously present in concentrations of 0.1-1.5% by weight. Polyacrylates are advantageous to use, but also quaternary ammonium compounds are optionally advantageous.

In particular, when hydrophobic pigments (such as talc or mica) are used, wetting agents can be advantageously used in addition. Advantageous are polyethylene / polypropylene block copolymers.

Furthermore, small amounts of anti-foaming agents, optical brighteners or flow improvers may be added.

It may also be particularly advantageous for the purposes of the present invention to add further antimicrobially active substances to the slurries of the invention, for example 3-iodo-2-propynyl butylcarbamate (IPBC), bronopol or antimicrobially active substances selected from the group of isothiazolinones, in particular those selected from the group 5-chloro-2

Methylisothiazolin-3-one, 2-methylisothiazolin-3-one, 2-n-octylisothiazolin-3-one, 4,5-dichloro-2-n-octylisothiazolin-3-one, 1,2-benzisothiazolin-3-one on, N- (C _t -C ₁₂ ) -alkyl-1,2-benzisothiazolin-3-one, preferably N-butyl-1,2-benzisothiazolin-3-one.

It is advantageous for the concentration of IPBC, bronopol or one or more isothiazolinones to be in the range from 0.00001 to 0.5% by weight, preferably 0.00005 to 0.1% by weight, particularly preferably 0 , 0001 - 0.01 wt .-%, based on the total weight of the aqueous suspensions or dispersions.

The following examples are intended to illustrate the invention. Example 1:

An aqueous suspension (pH 8.9) containing

76% calcium carbonate (GCC)

0.35% sodium polyacrylate

120 ppm ethylenedioxy (dimethanol) (EDDM)

15 ppm glutaric dialdehyde (GDA)

Water ad 100%

Example 2:

An aqueous suspension (pH 9.8) containing

30% calcium carbonate (PCC) 0.30% sodium polyacrylate 80 ppm ethylenedioxy (dimethanol) 10 ppm glutardialdehyde water ad 100%

Microbiological results of this suspension.

Here it was quantitatively tested how fast (1 hour to 7 days) the indicated amounts of active ingredient reduce the germ count of a germinated slurry. The germ counts of the unpreserved slurry (= without biocide) show that the germ spectrum in the slurry is viable.

Example 3:

An aqueous suspension (pH 10.1) containing

64% talc

0.3% sodium polyacrylate

1, 4% ethylene oxide / propylene oxide adduct (EO / PO adduct) 170 ppm ethylenedioxy (dimethanol) 15 ppm glutardialdehyde water ad 100%

Example 4:

An aqueous suspension (pH 7.8) containing

60% kaolin

0.35% sodium polyacrylate

185 ppm ethylenedioxy (dimethanol)

30 ppm glutaraldehyde water ad 100%

Claims

claims

1. Aqueous suspensions or dispersions (= "slurries") of minerals and / or fillers and / or pigments containing - one or more dialdehydes

- one or more Formaldehydabspalter.

2. suspension or dispersion according to claim 1, characterized in that the concentration of one or more dialdehydes in the aqueous suspensions or dispersions from the range of 0.0001 to 5.0 wt .-%, preferably 0.0005 to 1 , 0 wt .-%, particularly preferably 0.001 to 0.5 wt .-% is selected, based on the total weight of the aqueous suspensions or dispersions.

3. A suspension or dispersion according to claim 1, characterized in that the concentration of one or more Formaldehydabspaltern in the aqueous suspensions or dispersions in the range of 0.0001 to 5.0 wt .-%, preferably 0.001 to 1, 0 Wt .-%, particularly preferably 0.005 to 0.5 wt .-% is selected, based on the total weight of the aqueous suspensions or dispersions.

4. suspension or dispersion according to claim 1, characterized in that the weight ratios of dialdehyde to Formaldehydabspalter from the range of 50: 1 to 1: 1000 are selected, preferably 10: 1 to 1: 100, particularly preferably 5: 1 to 1: 20th

5. suspension or dispersion according to claim 1, characterized in that the dialdehyde is selected from the group glutaric dialdehyde (GDA), orthophthalaldehyde (OPA) or glyoxal.

6. A suspension or dispersion according to claim 1, characterized in that the formaldehyde releaser is selected from the group consisting of 1, 3-bis (hydroxymethyl) urea, (ethylenedioxy) dimethanol, 2,2 ', 2 "- (hexahydroxy) 1, 3,5-triazine-1, 3,5-triyl) triethanol, tetrahydro-1, 3,4,6-tetrakis (hydroxymethyl) imidazo [4,5-d] imidazole-2,5- (1H, 3H) -dione, α, α ', α "-trimethyl-1,3,5-triazine-1,3,5 (2H, 4H, 6H) -triethanol, 3,3'-methylene-bis- [5 methyloxazolidine] / oxazolidine, reaction products of N, N'-bis (hydroxymethyl) urea with 2- (2-butoxyethoxy) ethanol, Ethylene glycol and formaldehyde, (benzyloxy) methanol, 4,4-dimethyloxazolidine, 7-ethyldihydro-1H, 3H, 5H-oxazolo [3,4-c] oxazole, sodium N- (hydroxymethyl) glycinate, 1, 3-bis (hydroxymethyl) -5,5-dimethylimidazolidin-2 _> 4-dione, reaction products of ethylene glycol and formaldehyde, reaction products of tetrahydroimidazo [4,5-d] imidazole-2,5 (1H, 3H) -dione and formaldehyde, 1- [1,3-bis (hydroxymethyl) -2,5-dioxoimidazolidin-4-yl] -

1, 3-bis (hydroxymethyl) urea / diazolidinylurea, cis-1- (3-chloroallyl) -3,5,7-triaza-1-azonia-adamantan chloride, Dazomet.

7. suspension or dispersion according to claim 1, characterized by an additional content of 3-iodo-2-propynyl butylcarbamate, bronopol or one or more isothiazolinones, in particular selected from the group 5-chloro-2-methylisothiazolin-3-one, 2nd - Methylisothiazolin-3-one, 2-n-octyl-isothiazolin-3-one, 4,5-dichloro-2-n-octylisothiazolin-3-one, 1, 2-Benzisothiazolin-3-one, N ^ Ci-C ^ -AlkyM ^ -Benzisothiazolin-S-one, preferably N-butyl-1, 2-benzisothiazolin-3-one.

8. suspension or dispersion according to claim 7, characterized in that the concentration of 3-iodo-2-propynyl butylcarbamate, bronopol or one or more isothiazolinones in the range of 0.00001 to 0.5 wt .-%, preferably 0 , 00005 to 0.1% by weight, particularly preferably 0.0001 to 0.01 wt .-%, based on the total weight of the aqueous suspensions or dispersions.

9. Use of mixtures of one or more dialdehydes and one or more Formaldehydabspaltern for stabilizing aqueous suspensions or dispersions of minerals and / or fillers and / or pigments ("slurries")

Infestation or spoilage by microorganisms.