CS197737B1 - Rosin or tall resin based size and method of preparing same - Google Patents

Description

BACKGROUND OF THE INVENTION The present invention relates to a paper sizing and to a process for its preparation. Paper made from mere fibrous materials is poorly water-resistant, permeable and absorbent, and the font spills on it. If it is not to have these properties, a sizing agent must be added. They are sized by adding the sizing agent to the papermaking cloth (sizing in the mass) or by applying the sizing agent to the paper web (surface sizing). As the sizing agent, mainly natural and tall resin resins, synthetic resin, wax or paraffin dispersions, polyvinyl alcohol and other substances are used. The most commonly used sizing agents include rosin-based resin sizing and tall resin. These are anionic sizing agents which are prepared mostly by saponification (conversion of acids to sodium or potassium salts) of the resin. In this case, either the entire resin volume is saponified to form a neutral sizing agent, also called resin soap, or only a portion of the resin volume used is saponified, resulting in a so-called white sizing agent having a high (up to about 90%) free resin content. The sizing agent thus prepared is added to the fiber suspension and precipitated onto the fibers by an aluminum sulfate solution. In recent years, reinforced resin sizing has been used for sizing paper, i.e. sizing, which has been modified with suitable carbonic acids and derivatives thereof. The crosslinking is carried out, for example, on the basis of diene synthesis by addition of substances with at least one conjugated double bond to a so-called dienophile, which is a carboxylic acid or its anhydride with at least one double bond. Suitable dienophiles are, in particular, maleic, succinic, phthalic, crotonic or fumaric anhydrides. Condensation of the resin with formaldehyde and paraformaldehyde, respectively, at a suitable temperature in an alcohol or ether environment is also used. The saponification and resin application steps are similar to those described above. The improved solubility of the crosslinked sizing leads to a better dispersion of the sizing agent on the cellulose fibers after its precipitation and hence a better sizing effect. During the saponification of the crosslinked sizing agents with alkali hydroxides, or potash or soda, either the carboxyl groups are neutralized or the anhydride is hydrolyzed. Depending on the type of saponification component, a sizing with a liquid or paste consistency is produced. Generally, sizing saponified by potassium hydroxide or potash exhibit better flowability than sodium sizing at a concentration of up to 45%. At certain concentrations, the liquid and gel phases of the potassium sizing are separated, the sizing ability of the phases being different. Sodium sizing agents usually provide

9 7 7 3 7 higher density dispersions that are more difficult to handle. These sizing agents can therefore only be added to the pulp after a two-step dilution. A suitable paper sizing agent should be liquid at normal temperature, but at the same time it should have a high consistency and should dissolve well in cold water. The sizing agents used so far, including reinforced sizing agents, do not meet all these requirements. Reinforced sizing produced in liquid form, i.e. a concentration of less than 62%, is separated into a liquid and gel-like phase in a relatively short time, leading to difficulties in dispensing sizing in paper mills and uneven sizing of the paper produced. Solving this problem by constructing suitably adapted sizing solution storage tanks, or by stabilizing the size, is expensive. Stabilizing the sizing alone involves introducing additional substances into the sizing while increasing the time and cost of sizing. Another problem is the difficulty of dissolving otherwise highly effective crosslinked resin sizing agents prepared by modification and maleic anhydride. Improved solubility of these sizing agents can be achieved by increasing the maleic anhydride content of the sizing agent. This treatment can produce a stable liquid sizing agent with a dry matter content of 65-75%. However, a disadvantage of such an adduct is the difficult saponification of the resin due to the higher softening point of the resin.

These disadvantages are overcome by the present invention. The present invention relates to a rosin-based rosin or tall resin resin, optionally modified with dicarboxylic acids or derivatives thereof, which consists of a salt of resin acids with an ammonium or polyammonium cation of the formula below, wherein R 1 is an ammonium or polyammonium cation with one to four the radial of formula C _n H _2n and R ₂ = K or Na.

CHs COOR ₂ X ^ y ^ -CHCOO,

CH 3 to - - ^{CHCO 3}

CH3 = CH3

The present invention further provides a process for the preparation of rosin-based rosin or tall resin modified with or without dicarboxylic acids or derivatives thereof as described above, wherein the resin is treated with alkali amines, polyalkylamines or polyalkylpolyamines with one primary or two to three secondary nitrogen % in an amount of 13.6 to 24.7 parts by weight; per 100 parts by weight. a resin acid adduct, preferably in the form of an aqueous solution.

The rosin-based rosin or tall resin-based resin or cross-linked rosin-based resin of the present invention is a product of the reaction (salt) of a resin acid with an alkylamine, a polyalkylamine or a polyalkylpolyamine or a mixture thereof, and the subsequent saponification of the alkali. This salt is an active substance - a sizing agent, which, at a dry matter content of about 57.7% by weight, shows, without the addition of a stabilizing agent, better stability than the sizing agents used hitherto and a viscosity of 50 to 60 cP.

The dosage can be reduced by up to 60% compared to the sizing agents used hitherto.

Example 1

Rosin in the amount of 100 wt. parts were melted in a melting pot. In the connecting pipe between the melting and saponification boiler, 3.04 parts by weight of maleic anhydride were metered into the rosin. thereby modifying 20% of the total amount of 100 parts by weight of the rosin taken into the process. The saponification boiler was charged with 100 wt. parts of water and the water was heated by indirect heating to a temperature between 90-100 ° C. In addition, 13.6 wt. parts of diethylenetriamine. The contents of the saponification boiler were further heated so that the contents temperature did not fall below 97 ° C. The modified resin was then added to the saponification boiler with stirring. Finally, 20% by weight of potassium hydroxide was metered into the saponification boiler with stirring. parts. The resulting resin sizing was capable of being folded into storage containers. There was no need to stabilize the sizing as it was homogeneous. The sizing effect was tested on a Hercules Sizing Tester, which automatically measured the paper ink breakthrough time.

When dosing 1% by weight of the sizing agent according to the invention into the pulp and adding aluminum sulphate in an amount of 1.9% by weight. a sizing effect of HST of 402 seconds was achieved.

Example 2

As Example 1, but a tall resin was used instead of rosin, diethylenetriamine was replaced by dipropylenetriamine in the same amount. At a dose of 1 wt. aluminum sulphate had a sizing effect of HST of 446 seconds.

Example 3

As Example 1, however, diethylenetriamine was replaced by methylamine in an amount of 16 parts by weight. At a dose of 1% by weight of the fabric and with the addition of 1.9% by weight of aluminum sulphate, the sizing effect of HST was 385 seconds.

Example 4

As Example 2, but instead of dipropylenetriairin, triethylenetetramine was used in an amount of 15 wt. parts. At a dosage of 1% by weight in the fabric and after the addition of 1.9% by weight of aluminum sulfate, a sizing effect of HST of 345 seconds was achieved.

Claims (2)

SUBJECT VYNALEZU 1. Resin sizing based on rosin or tall resin, optionally modified with dicarboxylic acids, or derivatives thereof, characterized in that it consists of a resin acid salt with an ammonium or polyammonium cation of the formula CH ₃ coor ₂ -CHCOO xl ₃ R, ch ₃ J-CHCOO ^ CH ₃ wherein R 1 represents an ammonium or polyamomic cation of one to four N containing a bivalent radial of the formula C _n H _2n , and β ₂ = K or Na. 2. A process for the preparation of a rosin-based rosin or talc resin modified with or without dicarboxylic acids or their alkali saponified derivatives according to claim 1, characterized in that the resin is treated with alkylamines, polyalkylamines or polyalkylpolyamines with one primary or two to three secondary N, in an amount of 13.6 to 24.7 parts by weight; per 100 parts of resin acid adduct, preferably in the form of an aqueous solution.