FI118090B - Additive, use of additive in paper and board production, process for improving paper and board production, and process for improving paper and board product - Google Patents

Description

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ADDITIVE, USE OF ADDITIVE IN PAPER AND PAPERBOARD MANUFACTURE, METHOD FOR IMPROVING PAPER AND PAPERBOARD MANUFACTURE AND METHOD FOR IMPROVING PAPER AND 5 PAPERBOARD PRODUCTS

The present invention relates to an additive according to the preamble of the claims below, to the use of an additive in the manufacture of paper and board, to a process for improving paper and board production, and to a paper and board product.

The pulp suspensions used in the manufacture of paper and board contain, in addition to cellulosic fibers, various types of extractants, i.e., a heterogeneous group of lipophilic and / or hydrophilic substances. In particular, pulp suspensions containing mechanical pulp may contain significant amounts of lipophilic substances such as fatty acids, glycerides, sterol esters, sterols and resin acids. The addition of a large amount of rejection may also increase the amount of lipophilic substances in the pulp suspension. 4

Lipo Yesterday's substances are naturally hydrophobic and form what's called a pitch: * j *; insoluble sticky aggregates that easily deposit, especially at some temperatures: · · ···, on different surfaces of paper and board machines.

: Sticky aggregates typically adhere to cylinders, rolls, and fabrics in the drying section of paper and board machines, but may also cause problems elsewhere in paper and board machines, for example, by depositing the press section on the felt and rolls. Difficulties can lead to runner problems, track breaks and a thorough cleaning of the machine. Insoluble aggregates may also cause quality problems such as holes and dots in the paper product.

• · • · • ··. ·: \ 25 The appearance of resin on paper machines has seemed to occur ♦ ♦ * irregularly. Various methods for solving the problem have been proposed.

···; For example, longer storage of wood seems to reduce the amount of glycerides 4 • · · • * * · in the mechanical pulp. However, prolonged storage will result in • · a reduction in the lightness of the paper and cardboard and, of course, 30 storage costs.

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Regular washing of the paper machine with some chemicals can help solve the problem. Some additives, such as anionic dispersants, aluminum sulfate, adsorbents, cationic polymers or enzymes, have also been proposed. The materials and structures of the papermaking machine are also selected such that corrosion is avoided to prevent the formation of deposits.

Still, there are problems.

Sometimes, paper and board products may be degraded by an unexplained unpleasant odor. Often the smell component, such as starch, has been blamed for the odor. No single simple answer to odor problems has been found. Odor problems appear to occur more frequently on some paper machines than on others.

The papermaking process uses pulp gluing or surface sizing to give the paper product good hydrophobicity. At lower pH levels, that is, at pH <6, resin acids are generally used as adhesive components in combination with various IS aluminum components. At higher pH levels synthetic adhesives such as ASA and AKD are commonly used. A potential drawback of these adhesives is the formation of hydrolysis products which may be even more sticky than the Hima component itself.

It is an object of the present invention to provide an improved additive for use in the manufacture of paper and board to reduce the aforementioned disadvantages.

The object of the present invention is, in particular, to provide an additive which reduces the formation of sticky aggregates.

It is also an object of the present invention to provide an additive which; * · *; 25 provides an increase in hydrophobicity in the paper and board product.

It is a further object of the present invention to provide an improved method for reducing pitch problems in a paper and board machine.

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It is a further object of the present invention to provide an improved process for hydrophobicity, particularly so-called. short-term hydrophobicity in manufactured paper and pulp.

It is also an object of the present invention to provide an improved method of reducing odor nuisance in manufactured paper and board.

To accomplish the aforementioned purposes, the additive and the method for improving the production of paper and board and the method for improving the paper and board product according to the present invention are known from those set forth in the characterizing parts of the independent claims below.

A typical additive according to the invention comprises at least one component containing fatty acid glycerides, typically triglycerides having a high content of unsaturated, especially polyunsaturated, fatty acids.

It is believed that unsaturated fatty acids in the component can cross-link between glycerides in the added component and | 15 between the glycerides already in the pulp suspension, whereby the polymerization of the glycerides,? the so-called dehydration, will happen. : • · * * · · “It is believed that the unsaturated fatty acids of glycerides react without oxygen • · ''. Ί *. , especially at the highest temperatures, forming cross-linkages of glycerides • · ·. ···. between. Saturated fatty acids or resin acids, respectively * · * · · 20 are not believed to form crosslinks, whereby corresponding polymerization is not expected to occur.

»·· * • · *** 'It has now been unexpectedly discovered that it is possible to influence those in the pulp suspension. . to the behavior of lipophilic substances by the addition of this novel additive containing • 11 · glycerides, preferably triglycerides with a high content of unsaturated fatty acids, in particular polyunsaturated fatty acids. For example, the additive allows * i · 25 to influence the formation of sticky aggregates and * · * * ·.

behavior in the pulp suspension and on the paper or board web, the formation of unpleasant: * · * · odors in the paper or board product and / or the hydrophobicity of the final paper product.

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It has been found that it is possible to increase the rate of polymerization of glycerides by increasing the amount of unsaturated fatty acids, especially polyunsaturated fatty acids, in the pulp suspension. Thus, the content of non-polymerized glycerides, i.e. sticky glyceride aggregates, is reduced. It is also believed that the polymerized glycerides can form layers in the pulp suspension and in the paper web; around non-polymerized sticky aggregates, thus reducing the negative impact of these sticky aggregates in the papermaking process.

It has been found that the higher the amount of unsaturated, especially polyunsaturated, fatty acids in the pulp suspension, the fewer the runner problems caused by the pitch, i.e. the sticky aggregates.

A sufficiently high content of unsaturated and polyunsaturated fatty acids is required to ensure polymerization. More than 0.5 kg / h, typically 0.5-10 kg / h, more typically 2 to 5 kg / h, the addition of glyceride with a high content of polyunsaturated fatty acids can thus give the desired result.

15 An additive having a high content of unsaturated or polyunsaturated fatty acids may be added to the pulp suspension or to the paper or board web, for example by pulp or surface sizing. The additive may be added to the pulp suspension as a bulk sizing before the headbox, in the headbox or (·; ··· at any other convenient location. On the other hand, the additive may be added to wet or:

* * · ·. ··.; · -.

Thus, according to the present invention, a component to reduce pitch problems or unpleasant odors, or to increase hydrophobicity, may contain * · • · · '_ ·' fatty acid glycerides in which more than 10%, typically more than 40% fatty acids have more than 1 double bond * * · ·: ***; 25 fatty acid glycerides with> 60%, preferably> 65%, * · · · · · ·. , has 2 double bonds, and / or *. ** -. - fatty acid glycerides in which> 10%, preferably> 30%, typically> 45%, of the fatty acids have 3 double bonds.

The component of the invention may be crude or partially polymerized vegetable oils, such as sunflower oil containing a high amount of '5118090 linoleic (C 18: 2) acid, and / or linseed oil containing a high amount of linolenic (C). 18: 3) acid.

The additive of the invention may contain, in addition to said component, - one or more emulsion stabilizing agents, such as natural or synthetic polymers, for example starches, starch derivatives, CMCs, mannan, polyacrylamides, polyamines, - one or more surfactants, and / or at least one conventional adhesive component such as a synthetic adhesive.

Typically, cationic emulsion stabilizers may be used. Here, cationic starch derivatives such as - cold water soluble starches having a DS (degree of substitution) of> 0.1 or - conventional starch starches having a DS of 0.01 to 0.05 can be used.

Synthetic adhesives such as AKD, ASA, styrene acrylate, styrene maleic anhydride or styrene acrylic acid copolymers may be used. In the papermaking process, pulp suspensions normally contain some amounts of f resin acids and fatty acids, the latter occurring as free acids or as% esterified glycerides. The resin and fatty acids in the pulp suspension can be divided into two groups: ♦ * # * · - drying acids, i.e. unsaturated fatty acids such as pinolenic acid or # ♦ · 20 linolenic acid (C18: 3), linoleic acid (Cl 8: 2) and oleic acid (C 18: 1), and * **! non-drying acids such as resin acid and saturated fatty acids such as stearic acid. ··· (Cl8: 0), ante-iso-heptadecanoic acid (C17: 0ai) and palmitic acid (C16: 0). v * * * ·

It has now been found that drying acids, i.e. unsaturated fatty acids, «· ·.

* *; · Ratio to non-drying acids, i.e., resin acids and saturated fatty acids, seems to play an important role in the polymerization of glycerides and in the drying of a · · *. *. The higher the amount of unsaturated, especially {f * * · * · w # 11 * ··· * polyunsaturated fatty acids compared to the non-drying * ·;. · · Components, the faster polymerization will occur.

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It has now also been found that the decomposition of some non-drying acids in the pulp suspension or paper or board web may result in components such as heptaldehyde or hexaldehyde which cause a highly unpleasant odor. Furthermore, it has surprisingly been found that the polymerization of the fatty acids and / or glycerides of the invention in a pulp suspension or in a paper or board web can prevent odor-causing degradation.

In the following example, the results of measurements on a papermaking machine show that the polymerization of glycerides in the pulp suspension occurs simultaneously with less sticky agglomerates, i.e. pitch problems, occurring on the papermaking machine.

The example demonstrates that a relatively high concentration of drying acids, i.e. unsaturated fatty acids, promotes the polymerization of glycerides.

EXAMPLE

Samples were taken of: - Paper product at the wet end of a paper machine and 15 - dried Paper product.

The following fatty acids, ante-iso-heptadecanoic acid (Cl7: 0ai), pinolene and: ***; linolenic acid (Cl8: 3), linoleic acid (Cl8: 2) and oleic acid (Cl8: 1), concentration ·; ··: analyzed in each sample.

• 1 * · ·; * · ·. · 1 ·] An analytical method was used which • 1 • 1 20 - measured the concentration of free fatty acids as well as fatty acids: * • · «1 concentration in non-polymerized glycerides but which * ·· 1 - did not measure the concentration of fatty acids in polymerized glycerides .

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The concentration of ante-iso-heptadecanoic acid (C17: 0ai) was used as reference = 1.

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The following almost constant ratio between the different fatty acids could be observed in all the paper product samples taken from the wet end of the papermaking machine.

• 1 * · · • · 1 · 1 · · 118090 7 I C17: or Cl 8: 3 Cl 8: 2 C18 ante-iso-heptaprololene or t decanoic acid linoleic acid linoleic acid oleic acid 1 about 10 about 15 about In contrast, samples taken from the dried paper product gave two distinctly different results. Further experiments could show that the difference correlated with the difference in concentration of the resin acid in the pulp suspension IIA C17: or C18: 3 C18: 2 C18: ante-iso-heptapinolene or 10 decanoic acid linolenic acid oleic acid 1 about 10 about 8 IIB C17 C18: 3 C18: 2 C18: ante-iso-hepta-pinolene or "decanoic acid linolenic acid linoleic acid oleic acid f 15 1 about 1 about 1 about 4

It can be seen that the relative concentrations of unsaturated fatty acids: * · * · measured in Samples IIA are the same as in the wet end Paper Samples ·; **: samples. This seems to be nothing about unsaturated fatty acids *; polymerization has not occurred on a paper machine.

· »* * · * ·. ..ty * · ♦ .:. 20 Relative Concentrations of Unsaturated Fatty Acids Measured in Samples IIB · * ··. ** ·. are significantly lower than in samples IIA. This shows that the glycerides are * ··· * polymerized and dried, making the unsaturated fatty acids not measurable: the analytical method used.

Samples ΠΑ were taken at the concentration of the resin acid, i.e., the non-drying component.

*;] / 25 concentration, high in pulp suspension, generally greater than 0.6 kg / t (measured in finished * * paper) and samples IIB were taken at low resin acid concentration, : generally less than 0.6 kg / h (measured in finished paper) Glyceride polymerization «· * ·« was seen to continue in this particular pulp suspension as long as the 118090 8 resin acid concentration remained below 0.6 kg / h. As the resin acid concentration increased, the polymerization rate decreased .

Therefore, we believe that the ratio of drying to non-drying extractants in the pulp suspension plays an important role in the polymerization of the glycerides. Thus, the polymerization rate can be increased as proposed in the present invention by increasing the concentration of the drying fatty acid components.

Unsaturated, preferably polyunsaturated, fatty acids can be used for this purpose.

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Claims (21)

118090 An additive for the production of paper and board comprising at least one component containing fatty acid glycerides, preferably triglycerides, characterized in that the? 5 component contains a high content of unsaturated, preferably polyunsaturated, fatty acids. Additive according to claim 1, characterized in that the component contains fatty acid glycerides in which more than 10%, typically more than 40%, of the fatty acids have more than 1 double bond. Additive according to Claim 1, characterized in that the component contains: ¾ fatty acid glycerides in which> 60%, preferably> 65%, typically> 70%, of the fatty acids have 2 double bonds. '. . '; > Additive according to claim 1, characterized in that the component contains fatty acid glycerides in which> 10%, preferably> 30%, typically 15%> 45% of the fatty acids have 3 double bonds. The compound of claim 1.2. Additive according to claim 3 or 4, characterized in that M · 5 1 1 «« «**. the component is crude or partially polymerized vegetable oil, such as sunflower oil, ·· »« • ·,. containing a high amount of linoleic (C18: 2) acid, and / or linseed oil containing -5, a large amount of pinolene or linolenic (C18: 3) acid. * t * 1 2 • ^ 6. An additive according to claim 1, characterized in that it additionally contains • 1 · »» ··· 2 one or more emulsion stabilizing agents, such as natural or synthetic j '· polymers, for example starches, starch derivatives, CMC, mannans, • # · * ", 1 polyacrylamides, polyamines. * · • · "·! • · · · -f • ·>; 2; 1 · 7. An additive according to claim 1, characterized in that it additionally contains · 3:25 one or more surfactants. ··· v «2 • · · - 8. An additive according to claim 1, characterized in that it additionally contains 3 · «··« ·. at least one conventional adhesive component such as a synthetic adhesive. 118090 ίο '.. -I 9. A method for reducing resin problems in paper or board manufacture comprising treating a paper or board suspension or a paper or board web with an additive having at least one component containing fatty acid glycerides, typically triglycerides, characterized in that the component contains fatty acid glycerides wherein high content of I unsaturated, preferably polyunsaturated, fatty acids. Process according to claim 9, characterized in that the component contains fatty acid glycerides in which more than 1%, typically more than 40% of the fatty acids have more than 1 double bond. The process according to claim 9, characterized in that the component contains fatty acid glycerides in which> 60%, preferably> 65%, typically> 70%, of the fatty acids have 2 double bonds. Process according to claim 9, characterized in that component 15 contains fatty acid glycerides in which> 10%, preferably> 30%, typically> 45%, of the fatty acids have 3 double bonds. : T: Process according to Claim 9.10.11 or 12, characterized in that the component is a crude or partially polymerized vegetable oil, such as sunflower oil, containing a high amount of linoleic (Cl8: 2) acid, and / or linseed oil containing • * * 20 large amounts of pinolenic or linolenic (C18: 3) acids. A process for increasing hydrophobicity, in particular short-term hydrophobicity, in a paper or board product or for reducing odor nuisance in paper: a process comprising a paper or board suspension or a «M ί.,. Ί paper. -or treating the paperboard web with an additive containing at least one; * · *: 25 component containing fatty acid glycerides, typically triglycerides, •: ***: characterized in that ···: component contains high fatty acid glycerides * ·· Unsaturated, preferably polyunsaturated, fatty acids. : 11 118090: Method according to claim 14, characterized in that the component; »I contains fatty acid glycerides in which more than 1% of the fatty acids have more than 1 double bond, typically more than 40%. Process according to claim 14, characterized in that component 5 contains fatty acid glycerides in which> 60%, preferably> 65%, typically> 70%, of the fatty acids have 2 double bonds. Process according to claim 14, characterized in that the component contains fatty acid glycerides in which> 10%, preferably> 30%, typically> 45%, of the fatty acids have 3 double bonds. Process according to claim 14,15,16 or 17, characterized in that the component is a crude or partially polymerized vegetable oil, such as sunflower oil, which contains a high amount of linoleic (C18: 2) acid, and / or flax oil, which contains a large amount. pinolenic or linolenic (C18: 3) acid. Use of an additive according to claims 1-8 to improve runnability in the manufacture of paper and board using - a mechanical pulp containing fiber suspension, and / or · * · * - a fiber suspension from which a paper or board product contains> 0.6 kg / t · : * ·: Resin acid. Use of an additive according to claims 1 to 8 in paper and paperboard. 20 hydrophobicity, in particular the so-called short-term «···. ** ·. paper or paperboard to increase hydrophobicity. # ·· *,. Use of an additive according to claims 1 to 8 in the manufacture of paper and board to reduce the formation of unpleasant odors. • ♦ ♦ «• # · · · •« • e e e e e e 80 11 11 80 11 80 118090! PATENTKRAV |