EP0750069B1 - Agents for sizing paper, paperboard and cardboard and their use - Google Patents

Abstract

Sizing agent (I) for paper, pasteboard and cardboard, comprising a mixt. of (a) 5-75 wt% alkyl-ketene dimer dispersion and (b) 25-95 wt% cationic resin size consisting of a rosin dispersion and poly-(aluminium hydroxy chloride) cpds. Also claimed is a process for sizing paper etc. with (I).

Description

The invention relates to means for sizing paper, Cardboard and cardboard, a process for making them Means as well as their use.

With paper sizing one differentiates between mass and Surface sizing, with regard to mass sizing between acidic, pseudo-neutral and neutral resin sizing is distinguished. Mass gluing is understood to mean that Sizing that takes place in bulk during production.

The individual differences of these sizing processes will be described in detail in the applicant's EP-B-0 200 002.

During the acidic resin sizing through the use of alum with the associated disadvantages in the papermaking process, such as B. Formation of deposits in the paper machine, Corrosion and poor aging resistance of the paper pushed back more and more pseudo-neutral and neutral sizing will gain Meaning.

The pseudo-neutral sizing behavior compared to the neutral Process the disadvantages that it is on the one hand by the Use of sodium aluminate is expensive and on the other hand the pH value in the substance must be strictly observed.

Neutral sizing is done with a reactive substance (e.g. ketene dimers) or a cationic plastic dispersion worked as a sizing agent. Disadvantages with this Procedures include sensitivity to alum and other aluminum-containing salts, against lignin and contaminants in the waste paper, the necessary high amount and always observed ripening of the sizing.

The so-called surface sizing is a finishing variant the mass gluing of glued or not glued Paper. Through the process of subsequent surface sizing becomes a surface improvement for the application achieved as writing and printing paper, which becomes the Example in improved ink and eraser resistance as well shows improved gloss.

Rosin is preferred for mass and surface sizing used in the form of resin soap and resin dispersions, which are added to the liquid pulp and afterwards by adding aluminum compounds as aluminum resinate be canceled.

Surface sizing uses natural and synthetic Products used that are wound on the paper fibers and give the paper a water-repellent effect. The natural products are rosin, animal glue, starch. The synthetic products are copolymers of styrene and Acrylic esters, alkyl succinic anhydride, alkyl ketene dimers.

Sizing agents are predominantly from the newest state of the art synthetic products known.

From EP-B2-0 200 002 is a paper sizing agent as well known its use, which comes from a conventional reinforced rosin dispersion and polyaluminium hydroxychlorides exists and optionally agents such as polyamine or contains polyamide-epichlorohydrin resins.

EP-B1-0 074 544 describes a glue dispersion, which as continuous phase an aqueous solution of at least one Resin glue dispersant e.g. Polyamine, polyamide epichlorohydrin resin contains as well as a dispersed phase finely divided particles of a hydrophobic cellulose-reactive Glues such as alkyl ketene dimers and finely divided particles of Contains fumaric acid-reinforced rosin resin (e.g. tall resin). These can only be produced by extreme shear forces with the help of a homogenizer. They don't contain polyaluminium hydroxychloride, but need at least one water-soluble, nitrogenous cationic dispersant. The resinous reaction products are preferably used of epichlorohydrin with aminopolyamides etc.

WO 86/02677 describes a glue emulsion / dispersion, consisting of unsaponified resin acid in an aqueous Phase, a dissolved polyaluminum salt and preferably one cationic organic component such as e.g. Washing emulsions, Polyamines, cellulose derivatives or polyacrylates. The resin sizing is carried out at low pH values (pH <5).

EP-B-0 292 975 discloses the use of an emulsion from an alkyl ketene dimer glue in combination with a cationic Rosin glue and an insolubilizing agent, preferably alum, known in a manufacturing process a cardboard for certain containers as well as a process for the production of such containers. The cationic rosin glue and the insolubilizing agent are preferred mixed before use. The means to make it insoluble the rosin resin is only in the usual way later added; see. Page 3, lines 49 to 53. As a precipitant Alum is preferred and not before with mixed polyaluminium hydroxychloride.

EP-A-0 275 851 describes an aqueous dispersion, the dispersed phase a homogeneous mixture of resin material and a synthetic sizing agent, preferably ketene dimerate, contains as well as a polyaluminium compound at least four aluminum atoms. This manufacturing process The dispersion has the disadvantage that the dispersion or the homogeneous mixture of rosin and ketene dimerate is very complex to manufacture and therefore expensive.

DE-A-43 06 557 describes a composition for surface sizing of paper and cardboard containing an aqueous Dispersion of 1 to 40 wt .-% rosin resin and 1 to 5% by weight protective colloid and / or surfactant. As rosin resin are called tall, balm or root resin. As a cationic Polymers are polyacrylamide, urea derivatives, Called acrylic acid derivatives, etc.

US-A-4,522,686 describes a sizing agent for mass and surface sizing for paper, which is a dispersion a ketene dimer, a reinforced resin and water-soluble, nitrogen-containing cationic dispersants contains.

EP-A2-0 357 866 describes a cationic sizing agent for paper, which also has an excellent sizing effect for surface sizing. The sizing agent consists of a stable, aqueous, colloidal dispersion Solution of a salt of a copolymer consisting of N, N-dimethylaminoalkyl acrylate, Meth / acrylic acid ester of a fatty alcohol and concentrations of methacrylate and methacrylic acid.

EP-A-0 257 412 also describes a sizing agent for Paper containing a dispersion of copolymers Acrylonitrile and acrylic acid esters of an alcohol. This composition can be used as surface sizing agent for paper will.

Many of the sizes used so far have the disadvantage that it is predominantly synthetically produced copolymers deals, the production of which is complex and cost-intensive is.

The object of the invention is therefore to provide an inexpensive environmentally friendly and easy to manufacture agent for mass and surface sizing of paper, cardboard and cardboard to provide. The manufacturing process of glued papers is said to be known per se Means take place and can be carried out inexpensively be.

The object of the invention is surprisingly simply achieved by a means for gluing paper, cardboard and cardboard consisting of 5 to 75% by weight dispersions of alkylketene dimers and 25 to 95% by weight of a cationic resin glue, the cationic resin glue being made from a rosin -Dispersion and polyaluminium hydroxychlorides. The agent can be used both as a mass and as a surface sizing agent. The agent is liquid and is in dispersion form.
In addition to the above means, objects of the invention are the method according to claim 2 and the use according to claim 3.

Rosin resins such as tall resin, Balsam resin or root resin used, the resin can be partially saponified or unsaponified.

As a rosin dispersion, commercially available ones are preferred Dispersions used like the rosin resin Kentosol AP® according to EP-B-0 200 002. For these dispersions either Conventionally unreinforced rosin resin dispersions or using the conventionally reinforced resin glue dispersions, those made from maleic anhydrite or fumaric acid modified Rosin or hydrocarbon resin with additives made of protective colloids or surface-active substances will. These commercial rosin dispersions with a solids content of 10 to 50% by weight have the advantage that they are made of natural resin and thus are environmentally friendly and recyclable. Compared to the polymers or synthetically produced sizing agents they are characterized by a significantly better price / performance ratio out.

Commercial protective products such as casein, Soy protein, polyvinyl alcohol, polyvinyl pyrrolidone, carboxymethyl cellulose, Starch, collages, manogallactans and alginates used.

As a surface-active substance (surfactants), alkylbenzyl sulfonates, Alkylphenol polyglycol ethers, alkylphenol polyglycol sulfonates, Phosphoric acid esters, alkyl polyglycol sulfosuccinates can be used to disperse the rosin resin.

The aqueous dispersions also contain commercially available Polyaluminum hydroxychloride. You will instead used by alum and serve as a precipitant.

Commercially available cationic polymers can also contain be. These additives generally consist of aqueous ones Solutions or dispersions of, for example, polyacrylamide, Polydialkyldimethylammonium chloride, polyethyleneimine, Polyaminepichlorohydrin resin, polyamidepichlorohydrin resin, Melamine formaldehyde resin, urea formaldehyde resin, Polydicyandiamine formaldehyde resin and further cationic Copolymers of styrene, methacrylic acid ester, acrylic acid ester, Methacrylic acid, acrylic acid, N, N-dimethylaminomethacrylate.

It is generally known that cationic rosins or rosins considered in addition to the advantageous Resistance to hot hydrogen peroxide solutions also have disadvantages. Above all, the low counts Resistance to lactic acid liquids as well as the The fact that the sizing is only in the acidic pH range (pH 4 to 6) can be done.

To the above Avoiding disadvantages are invented to the cationic resin glues so-called ketene dimer glues given. These ketene dimers have the advantage that they are lactic acid resistant, but show intolerance with alum and aluminum salts. Further can only use sizes in the neutral to weakly alkaline pH range (pH 7 to 8.5) will. Surprisingly, the sensitivity to aluminum-containing salts in the agent according to the invention not observed.

The types of glue therefore do not require aluminum sulfate or alum as a precipitant. Ketene dimers are hydrophobic cellulose-reactive sizing agents of the general formula: [R-CH = C = O] ₂ where R = H, alkyl, aryl, cycloalkyl, alkaryl, arakyl, benzyl etc.

It was found that, surprisingly, the invention Mixture of cationic resin glue and alkyl ketene dimers a paper sizing agent with the usual additives that is applicable over a wide pH range, is environmentally friendly and easy to manufacture. The pH insensitivity is so great that even the addition of alum does not bother, although according to the invention precisely on the use can be dispensed with by alum.

This result was completely surprising since the expert first had to assume that when combining the rosin dispersion and the ketene dimer dispersion in the presence a mixture of two dispersions of aluminum-containing salts arises, which leads to a heterogeneous or speckled Surface and thus completely useless results leads. Under no circumstances could it be expected that such Mixtures of two sizing agents, precipitants and other additives at all homogeneous on or in the fiber material can be introduced and by simple Change the respective mixing ratio sizing agent with special, modified properties. It has also been shown that when using the invention Mixture of alkyl ketene dimer dispersions and cationic resin glue even better and more reliable Results in sizing can be achieved and the process of making sized papers can be carried out more easily and reliably.

The manufacture of the product according to the invention is relative simple. It can be done, for example, by looking at the individual Introduces components in a stirred tank.

In the following examples and reference examples the mixture, its preparation and use explained in more detail.

Reference Example 1 Resin dispersion (according to the state of the art)

100 parts by weight tall resin or balsam resin or a mixture thereof with 7.5 parts by weight of maleic anhydride or fumaric acid at 200 ° C in a reaction time of 2 h with each other implemented. At a temperature between 160 ° C and The reacted resin becomes 170 ° C. with 2.5 parts by weight of 20% strength Saponified sodium hydroxide solution with slow addition. After saponification and with further vigorous stirring the resin with the addition of 50 parts by weight of a 10% casein solution dispersed. For the digestion of this casein solution, 2 parts by weight Borax used. Further water is added to the Setting the desired concentration.

Reference example 2 Cationic resin dispersion (according to EP 0 200 002)

100 parts by weight of the resin dispersion according to 1) are mixed with 100 parts by weight of water, and then 200 parts by weight of polyaluminum hydroxychloride with an Al ₂ O ₃ content of 10% are added with vigorous stirring. After the polyaluminium hydroxychloride addition has ended, the mixture is stirred for a further half an hour. Then another 10 parts by weight of a 12.5% strength polyamidoamine-epichlorohydrin resin solution (such as Luresin KN from BASF) are added. After stirring for half an hour, a stable cationic resin dispersion is obtained. The order of addition of the three components in the cationic resin dispersion can be varied as desired.

Reference example 3 AKD emulsion (according to the state of the art)

100 parts by weight of an aqueous solution with 5% cationic Starch and 1% lignosulfonate sodium is used at 60 to 70 ° C 15 parts by weight of a melted AKD wax (manufactured from palmitic and stearic acid mixture) mixed intensively. The mixture is then mixed in with a homogenizer homogenized under high pressure. With the addition of further water and the pH adjustment with sulfuric acid becomes the AKD emulsion to a concentration of 10% and a pH of 3 to 4 brought. Instead of cationic starch and lignosulfonate sodium can be used to make AKD emulsion among other things also synthetic polymers or surface-active Substances are used. Examples include: polyacrylamide, Dicyandiamide-formaldehyde resin, fatty alcohol ethoxylates, Polyamine-epichlorohydrin resin, polyalkylamine-epichlorohydrin resin, Glycerol stearates.

example 1 Product according to the invention

The product according to Reference Example 2 is stirred with the Product according to Reference Example 3 in a ratio of 3: 1 mixed. The mixture obtained is stable in storage and can diluted or undiluted for sizing paper, cardboard both in bulk as well as superficially on the finished one Paper or cardboard can be used. The mixing ratio is variable in a wide range. Other additions of cationic Products such as polyamidoamine-epichlorohydrin resin, dicyandiamide-epichlorohydrin resin, Polyacrylamide are possible and can improve the sizing.

The superiority stems from the following comparative tests emerged:

Comparative tests

The proprietary product Flexsize 114 was compared European patent application 0 074 544 with two according to the invention Patent holder's commercial products, namely Kentosol KF 1 and Kentosol KF 2. The commercial product Flexsize 114 contains, according to the applicant's investigations, 15 to 20% Rosins, 2 to 5% alkyl ketene dimers and 5 to 8% Alum. It also contains a quantitatively difficult to determine Amount of water-soluble nitrogenous cationic Dispersants.

The applicant's commercial products have the following composition: Kentosol KF 1 Kentosol KF 2 Rosin 10% 11.25% Alkyl ketene dimer wax 5% 3.75% Polyaluminium hydroxychloride 20% 22.5%

None of these products contain a water-soluble nitrogenous one cationic dispersant.

Test conditions : Waste paper fabric pH 6.0 with a basis weight of 80 g / m ^{2 was used} . Was dried at 120 ° C for 7 min on a Rapid Koethen system.
Additional quantities of 7, 8 and 10% of the merchandise (Hdw) were tested. The degree of sizing Cobb60 was measured.

The test results are summarized in the table below: glue % Hdw quantity Cobb60 (degree of sizing) Flexsize 114 7 no sizing 8th 71 10th 35 Kentosol KF 1 7 31 8th 30th 10th 22 Kentosol KF 2 7 39 8th 31 10th 22

The results show a much better degree of sizing when using considerably less and less expensive sizing agents.

Claims (3)

1. An agent for sizing paper and cardboard, characterized by being a mixture of from 5 to 75% by weight of dispersions of alkylketene dimers and from 25 to 95% by weight of a cationic resin size, said cationic resin size consisting of a colophonium dispersion and poly(aluminium hydroxide chlorides).
2. A method for sizing paper and cardboard, characterized in that a mixture of from 5 to 75% by weight of an alkylketene dimer and from 25 to 95% by weight of a cationic resin size is used, said cationic resin size consisting of a colophonium dispersion and poly(aluminium hydroxide chlorides).
3. Use of a mixture of from 5 to 75% by weight of an alkylketene dimer and from 25 to 95% by weight of a cationic resin size as the sizing agent in the production of paper and cardboard, said cationic resin size consisting of a colophonium dispersion and poly(aluminium hydroxide chlorides).