FI59132B - HJAELPMEDEL FOER FRAMSTAELLNING AV PAPPER OCH PAPP - Google Patents

Description

ANNOUNCEMENT 59-130 lbj (11) utläogningsskript ° y 1 ° * ♦ gW c (4¾ r-tenUi «yUr.:· .: Uy? 0 06 1001 (51) K» .lk? /Lnt.C1.3 D 21 H 3/02

ENGLISH —FINLAND (21) PtMnttlhakeimi · - PttwitamSknlng 76082U

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(32) (33) (31) Requested Muolkeut — Begird prlorltvt 05 .OU.75

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) P 251 ^ 908.0 (71) Cassella Aktiengesellschaft, Hanauer Landstrasse 526, Frankfurt am Main,

Federal Republic of Germany-Förbundsrepubliken Tyskland (DE) (72) Roland Fejoz, Aix-Les-Bains, France-Frankrike (FR), Winfried Pommer,

Bad Homburg v.d.H., Karlfried Keller, Bergen-Enkheim, Federal Republic of Germany-Förbundsrepubliken lyskland (DE) (7 ^) Oy Kolster Ab (5 ^) Excipient for the manufacture of paper and board - Hjälpmedel för fram-s + ällning av papper och Papp

The present invention relates to an excipient which, alone or in admixture with other water-soluble binders, is used in the manufacture of paper, board, cardboard and nonwovens having improved wet and dry strength and / or improved surface water resistance, which is indefinitely dilutable and alkaline curable. obtained by condensing the amino resin-forming agent, formaldehyde and sulfamate in a molar ratio of 1: 2.5 to 7 * 0.1 to 1.5 at temperatures between 80 and 120 ° C at a pH of 7 to 11, with condensation being continued until 50 The sample set to a resin content of # gives a viscosity of at least 500 DIN eq and the sample set to a resin content of 20 n gives a viscosity of not more than 300 DIH seconds, measured at 20 ° C in a 4 mm flow vessel, and the method of making paper, board, cardboard and nonwovens, with improved wet and dry strength and / or improved water resistance of the surfaces, whereby the method The excipient according to the invention is added to the pulp in an amount of 0.5 to 5% by weight before forming the sheet or is introduced into the paper web or nonwoven between web formation and winding 2,513,132 or to the finished paper or nonwoven 35 To a weight of -35 in the form of a solution, preferably a solution of 1-1Θ ^ 6, optionally mixed with other water-soluble products.

It is already known that sulphite-modified melamine resins can be used to improve the strength properties of paper (see, for example, German Publication Publication DOS 2,301,035). It has also been previously described that these resins can be used to improve the wet and dry strength of paper when introduced into it. from the surface of the paper (e.g. with a gluing press). Such a procedure represents a substantial advantage over the long-known method in which melamine resin is made cationic by adding significant amounts of strong acids and is allowed to actively affect cellulose in the pulp, as acid saving has a beneficial effect on the longevity and strength of the paper produced. However, it has been found (cf. e.g. Wochenblatt fur Papierfab. 17, 671/1973) that sulphite-modified melamine resins can be used according to this method only when the paper contains a minimum content of aluminum sulphate, since the resins harden only when acidic. However, this property negates the above-mentioned advantage of acid-free processing of resins in practice, since Aluminum sulfate clearly reacts acidically and gives the paper undesired properties. The processing possibilities of known sulfite-modified melamine resins in a sizing press are further limited by the fact that the degree of condensation of the resins must be relatively high in order to be effective. However, this reduces the amount to be applied and thus also the strength improvements that can be achieved because the fast-moving paper web cannot receive sufficient amounts of viscous resin.

Thus, there is a need to find low viscosity excipients for paper that can be introduced through the surface and that cure without the aid of acids or acid salts.

It is also known (cf. German Public Procurement Publication DOS 2,241,15b) that, after drying, melamine-formaldehyde resins are not sufficiently waterproof binders for surface sizing after drying, such as, for example, starch, casein, polyvinyl alcohol, methylcellulose, sodium carboxoxy. or waterproof. The present embodiments of melamine-formaldehyde resins in these fields of application have the considerable disadvantage that they are not sufficiently effective in the basic range. Therefore, there is a need to find an excipient to improve the water resistance of materials for surface sizing treatment of paper 3,5132, which also gives good values even in the alkaline range up to pH 11, as some important pulps for surface treatment of paper are run alkaline. Thus, hardness in the alkaline range is required for this application, while the intrinsic viscosity of the excipient does not play a decisive role, since the pulps for the surface treatment of the paper themselves have a relatively high viscosity. Known sulfite-modified melamine resins have the required hardenability in the basic range, but in an undesired amount.

It has now been found that practical requirements can be met and the described disadvantages of known products avoided by using an adjuvant to improve the wet and dry strength of paper, board, nonwovens and / or surface waterproofing by condensing the amino resin, formaldehyde and sulphamates. in a molar ratio of 1: 2.3-7: 0.1-1.3 at temperatures between 80-120 ° C and a pH between 7-11 «, whereby condensation is continued until the sample set at a resin content of 30 # at 20 ° C gives a viscosity, measured in a 4 mm DIN flow container, of at least 300 DIN seconds and a sample set at a resin content of 20 #sn gives a viscosity of up to 300 DIN seconds, measured at 20 ° C in a 4 mm DIN flow container. These aminoplastic resins used as excipients according to the invention can be diluted indefinitely with water and can be cured in the basic range. As the aminoplastic former, the excipient according to the invention is used in the preparation of a mixture of 75 to 100% by weight of melamine and 0 to 25% by weight of urea, dicyandiamide or guanamine. Preferred excipients according to the invention are obtained when melamine alone is used as the amino resin former. As the sulfamate, sodium sulfamate condensation is preferably used. Particularly preferred products according to the invention are obtained when the amino resin former, formaldehyde and sulfamate are condensed in a molar ratio of 1: 3.0 to 6: 0.3 to 0.8. The condensation can be carried out in a technically particularly simple manner at temperatures between 80 and 100 ° C. Of particular importance for the chemical structure and technical properties is the degree of condensation of the excipients according to the invention, which is characterized by viscosity. For the preparation of excipients for surface treatment of paper, such as sizing compounds, it is in many cases advantageous to condense until an aqueous solution of 20 # resin in samples at 20 ° C gives a viscosity, measured in a 4 mm DIN flux, of at least 12 DIN -sekuntia.

The present invention also relates to a process for the production of paper, board, cardboard and non-fibrous mats with improved wet and dry strength and / or improved water resistance of surfaces, the process providing a condensation product according to the invention which is infinitely dilutable with water and alkaline. in the form of a 0.5-35% by weight solution, preferably a $ 1-10 solution, optionally mixed with other water-soluble materials, to be curable in the region, as an intermediate in the formation and rolling of the paper on the pulp or paper web or nonwoven or on the finished paper or nonwoven. products. A particularly preferred embodiment comprises applying the condensation product according to the invention to the formed paper web in a gluing press or before it, e.g. by spraying or in the case of cardboard, before felting the different layers, it is particularly preferred that the condensation product is in the form of a 0.5-35 weight solution. , preferably in the form of a 1-10 solution, optionally together with water-soluble products.

A particular advantage of the excipient according to the invention is that, after forming the sheet, the substance can be applied to the surface of the paper web by means of an application device, e.g. a gluing press, and penetrates so well that at least the same effect on wet strength is achieved. This provides an exceptionally good recovery advantage, as the substance is $ 100 combined with the paper and, as with pulp addition, cannot be wasted with the underside of the wire. However, application to the pulp after the pH has been adjusted to 2-3 with acid according to hitherto known technology is likewise possible for new excipients. The addition of the excipient according to the invention causes not only an increase in the wet breaking load of the papers or similar products made according to the invention, but also surprisingly a strong increase in the wet breaking load with increasing addition rates without already increasing the saturation value (see graph in Example 1). In addition, there is an unusually strong increase in dry fracture load and sulfur compression pressure when the excipients according to the invention are added.

Particular advantages are obtained by combining the excipients according to the invention with other water-soluble binders, such as, for example, starch or polyvinyl alcohol, in the pH range from 5 to 11%, because the excipient according to the invention can be replaced by one of these water-soluble binders without a reduction in the wet strength of the substrate, even when water-soluble binders used alone do not increase virtually any wet strength. In addition, the dry strength achieved by the additives according to the invention can be considerably improved by adding certain water-soluble binders, such as, for example, medium-viscosity polyvinyl alcohol. Finally, by combining the excipients according to the invention with such water-soluble binders, a clear improvement in the dry strength of the substrate treated with them and a reduction in the water sensitivity of the surfaces is also achieved.

The percentages mentioned in the following embodiments are percentages by weight.

Example 1 a) Molar ratio 1: 3: 0.6 184β g (24 moles) of formaldehyde, from $ 39, are mixed with 20 ml of 2N sodium hydroxide solution, with 1440 g (4.8 moles) of 40 # sodium sodium sulfamate solution and 1008 g (8 moles) of melamine and condensed at 90 ° C and pH 10 for about 4 hours until the sample cooled to room temperature no longer runs. Now add 3600 ml of water and cool. A resin solution is obtained with a viscosity of 14 seconds (measured at 20 ° C in a 4 mm DIN flow vessel) and a resin content of 27 b) Molar ratio 1: 3: 0.3 462 g (6 moles) of formaldehyde, from $ 39 , mixed with 3 ml of 2N sodium hydroxide solution, 180 g (0.6 mol) of 40 .mu.l of sodium sulphamate solution and 232 g (2 mol) of melamine and condensed at pH 10 and 90 ° C for about 4 hours until the sample cooled to room temperature no longer runs. Now add 900 ml of water and condense at 90 ° C for a further 2 hours until the sample at 20 ° C mixed with the same amount of 3 # saline solution directly gives turbidity. Cool to room temperature and add another 300 ml of water. A resin solution with a viscosity of 35 DIN seconds and a concentration of $ 22 is obtained.

c) Molar ratio 1: 6: 0.2 924 g (12 moles) of formaldehyde, from $ 39, are mixed with 7 ml of 2N sodium hydroxide solution, with 120 g (0.4 moles) of 40 δ sodium sulfamate solution and 252 g (2 moles) of melamine and condensed at 90 ° C and pH 10 for about 2 hours until the sample no longer runs at room temperature. Now add 1500 ml of water, cool and adjust the pH from 7 to 9 with 0.6 ml of 10 μl sodium hydroxide solution. A $ 20 resin solution with a viscosity of 50 DIN seconds is obtained. D) Molar ratio 1: 6: 0.1 924 g (12 moles) of formaldehyde solution, 39 #, are mixed with 10 ml of 2N sodium hydroxide solution, 900 ml: with water, 60 g (0.2 moles) of 40% sodium sulfamate solution and 252 g (2 moles) of melamine and condensed at 90 ° C and pH 10 for about 2 hours until room temperature is reached. the cooled sample no longer runs. 1400 ml of water are now added and, after cooling, the pH is adjusted to 9 with 2N sodium hydroxide solution. A $ 20 resin solution with a viscosity of 14 DIN seconds is obtained.

e) Molar ratio 1: 2.5: 1.5 385 g (5 moles) of formaldehyde, from $ 39, are mixed with 10 ml of 2N sodium hydroxide solution, with 900 g (3 moles) of a sodium sulfamate solution of $ 40. and 252 g (2 moles) of melamine and condensed at pH 11 for about 4 hours at reflux until the sample cooled to room temperature no longer flows. Now add 900 ml of water and cool. A 20 # resin solution with a viscosity of 20 DIN seconds is obtained.

Example 2

Aqueous solutions of the condensation product obtained according to Example 1a) containing 2.5; 5 »0; 7 * 8; and $ 10.0 active ingredient, was applied with a size press to a wood-containing paper having a basis weight of about 55 g / m 2 and dried with 140 ° C hot air in a drying channel. Due to the residence time, the paper web only reached a residence time when rolling with a dry matter content of about $ 95.

The following measurements were made on the papers thus treated and on the untreated papers for comparison: 1. After 24 hours of storage at 20 ° C and 65 ° C relative humidity, the breaking load in the longitudinal and transverse directions and the sulfur compression pressure were measured *.

Table 1 shows the measured values as the breaking load in the longitudinal direction I, in the transverse direction I and as the sulfur compression pressure.

2. The paper was stored for 24 hours at 20 ° C and 65 n relative humidity and then for 1 hour in 20 ° C water and the longitudinal and transverse breaking load of the badger paper was measured. Table 1 shows the measured values for the breaking load a) in the longitudinal direction II and in the transverse direction II.

3. The paper was heated for 10 minutes at 120 ° C, then stored for 1 hour in water at 20 ° C, and then the breaking load in the longitudinal and transverse direction was measured from the wet paper. Table 1 shows the measured values as breaking load in the longitudinal direction III and in the transverse direction III.

Table 1 shows, in illustrative form, the dependence of the measured mechanical strength values of the papers on the amount applied.

7,591 32

table 1

Concentration of solution applied [#] - 2,5 5 7 »5 10

PH of the applied solution - 8.6 8.8 8.9 9 * 3

Applied active substance g / m2 0 0.61 1.16 1.75 2.56 io on Atro paper 0 1.12 2.14 3.22 4.35 2

Sulfur recording pressure kp / cm 0.8 0.92 1 »05 1.13 1» 21

Breaking load: I 4 »15 5.9 6.5 6.9 7 * 3 longitudinally: [kp] II 0.7 1.3 1.7 1.85 1.95 III 0.7 1.6 2.3 2.6 2.9

Breaking load: I 1,251.7 1.81.9 2.1 transversely [kp] II 0.15 0.3 0.45 0.5 0.55 III 0.15 0.45 0.6 0.8 0.85

If, instead of the aqueous solutions of the condensation product obtained in Example 1a), corresponding solutions of the condensation products prepared according to Examples 1e), Id) and e) are used, comparable results are obtained.

Example 3

The filter paper (S + S no. 557) was impregnated by dipping with a solution according to Example Ib) containing 20 g of active ingredient per liter. In this case, the solution was in each case adjusted to the prescribed pH with sodium hydroxide or formic acid. to determine the effect of the excipient at a different pH. After immersion, the paper samples were allowed to lightly air dry and then dried on a steam heated drying cylinder at 120 ° C to a residual moisture content of 2-3% and then air conditioned for experiments at 20 ° C and $ 65 relative humidity.

The following breaking loads were measured from the samples:

PH of the solution Fracture load in kg 6 2.28 7 2.50 9 2.43 11 2.05

A surprising result for the required substance is a slight decrease in the measured value as the pH increases. This finding is particularly important because a large proportion of solutions for application in an adhesive press or coating apparatus, primarily in combination with other products due to compatibility, viscosity or stability, must be made temporary.

If, instead of the aqueous solutions of the condensation product obtained according to Example Ib), corresponding solutions of the condensation products prepared according to Examples 1e), d) and e) are used, comparable results are obtained.

Example 4 2

On wood-containing paper with a basis weight of about 55 g / ® *, one of the following solutions was applied in the same manner as described in Example 2:

Solutions I:

Aqueous solutions of medium viscosity polyvinyl alcohol containing 1,0, 2,0, 5 * 0, 4 * 0 $ active substance (pH 5 * 7) ·

Solutions II:

Aqueous solutions of the condensation product obtained according to Example 1a) containing 2.5, 5 * 0, 7.5> 10.0 l of active substance (pH 9.0-9.5) ·

Solutions III:

Aqueous solutions of medium viscosity polyvinyl alcohol, as in solutions I, and the condensation product obtained according to Example 1a), the concentration ratio of polyvinyl alcohol to condensation product being 1.0: 2.5 in each case and the total concentrations of Ikos were 5 * 5, 7 * 0, 10 , 5 and 14.0 £ (pH 9.1-8.6).

Solutions IV:

Aqueous solutions of medium viscosity polyvinyl alcohol, such as in solutions I and the condensation product obtained according to Example 1a), in which case the concentration ratio of polyvinyl alcohol to condensation product was in each case 1.0: 1.0 and the total concentrations of the solutions were 2.0, 4 * 0, 6.0 and 8.0 (pH 8.6-8.0).

The papers were then dried as described in Example 2.

Papers thus treated were stored for 24 hours at 20 ° C and 65% relative humidity and then for 1 hour in water at 20 ° C to measure the breaking load from the wet paper in the longitudinal and transverse directions. Graphs 1 and 2 show the dependence of the obtained measurement results on the quality and application rate of the applied solution as well as the measured values on untreated paper.

Abbreviations and symbols in Figures 1 and 2 have the following meanings: NBL [kp] * »longitudinal wet breaking load NBQ [kp] - transverse wet breaking load M f - ^ J = amount of active substance applied based on the weight of the treated paper X- = measuring point for solution 1

x = measuring point for solution II

C3 = measuring point for solution III

O = measuring point for solution IV

These measurement results show the good reactivity of the excipient according to the invention with polyvinyl alcohol. Replacing the condensation product of Example 1a) up to 50% with polyvinyl alcohol which only slightly increases the water resistance per se does not lead to a deterioration in the high water resistance of the paper obtained by treating the condensation product according to Example 1a) alone.

In the following, the present invention is compared with GB Patent 1,360,339. Application Examples 1-1 + of GB Patent 1,360,339 were repeated and the products obtained were compared with the product of Example 1h now described.

Aqueous solutions of the obtained condensation products containing 7.5% by weight of active ingredient were applied in a gluing press to wood pulp-containing paper 2 having a pH of 9 and a basis weight of about 55 g / m 2 and dried by means of hot air in a drying channel at 10 ° C. Due to the drying time, the paper webs had only a dry content of 95 # when rolled. The same procedure was repeated with paper having a pH of 11.

The papers were then heated for 10 minutes at 120 ° C and then allowed to stand in water at 20 ° C, and the breaking load of the wet papers was determined in the longitudinal and transverse directions. The service life of the remaining impregnation solution, i.e. the time until the impregnation solution becomes unusable due to turbidity and the formation of fines, was determined. The test results are shown in Table 2.

Table 2 GB 1 360 339 Melamine: formaldehyde: Paper- Wet Breakage- Use- „. . sodium sulfamate grinding load time

Example No. "/ r y r n pH / kg / / miny length.

1 1: 1+: 1 9 2.5 1.1+ 115 11 1.6 0.9 2 1: 3: 0.3 9 2.7 1.5 55 11 1.9 1.0 3 1: 3 : 2: 9 1.1 + 0.8 2l + 0 11 1.1 0.5 1+ 1: 2.2: 0.05 9 1.1 0.6 108 11 0.7 0.1+

Product according to the invention 1: 3: 0.3 9 2.7 1.7 115 11 1.9 1.0 10 591 32

The results show that the products according to Examples 1, 3 and h of the GB publication have a significantly weaker effect than the product according to the invention. Although the product according to Example 2 of the GB publication has only a slightly weaker effect than the product according to the invention, its stability is only about% of the stability of the product now described. As can be seen from the above, the products according to the invention have very good effect-stability properties, which are particularly important from a technical point of view, and consequently the products according to the invention are technically considerably better than the corresponding known products.

Claims (12)

11 5 913 2 1. Excipient, used alone or in combination with other water-soluble binders, for the manufacture of paper, board, cardboard and non-fibrous mats with improved wet and dry strength and / or improved water resistance of surfaces, which can be diluted indefinitely with water and cured in neutral and alkaline by condensing the aminoplastic-forming agent, formaldehyde and sulfamates, characterized in that the excipient is obtained by condensing the aminoplastic-forming agent, formaldehyde and sulfamate in a molar ratio of 1: 2.5-7: 0.1-1.5 at temperatures between Ö0-120 ° C and pH between 7 and 11 »in which case the condensation is continued until the viscosity of the sample adjusted to 50 # resin content is at least 300 DIN seconds and the viscosity of the sample adjusted to 20 # resin content is not more than 300 DIN seconds, measured at 20 ° C k mm in a DIN flow vessel, and used as an amino resin-forming agent in condensation n a mixture of 75 to 100% by weight of melamine and 0 to 25% by weight of urea, dicyandiamide or guanamine. Excipient according to Claim 1, characterized in that melamine is used as the amino resin former. Excipient according to Claims 1 to 2, characterized in that sodium sulfamate is used as sulfamate. * 1. Excipient according to Claims 1 to 3, characterized in that the condensation takes place in a molar ratio of 1: 3.0 to 6: 0.3 to 0.8. Excipient according to Claims 1 to H, characterized in that the condensation takes place at temperatures between 80 and 100 ° C. Excipient according to Claims 1 to 5, characterized in that the condensation is continued until the viscosity of the 20% aqueous solution of the sample at 20 ° C, measured in a t mm DIN flow vessel, is at least 12 DIN seconds. Process for the preparation of an excipient according to Claim 1 for improving the wet and dry strength of paper, board, cardboard and nonwovens and / or for improving the water resistance of surfaces, characterized in that the amino resin, formaldehyde and sulphamate are condensed in a molar ratio of 1: 2.5 to 7: At temperatures of 0.1 to 1.5 ° C and a pH of 7 to 11, with condensation continuing until the viscosity of the sample adjusted to a resin content of 50 # is at least 300 DIN seconds and that of a sample adjusted to a resin content of 20 # is the viscosity does not exceed 300 DIN seconds, measured at 20 ° C in a 1+ mm DIN flow vessel, and a mixture of 75 ~ 100 wt.% melamine and 0-25 wt.% urea is used as the amino plastic former in the condensation, dicyandiamide or guanamine. 12 5 91 3 2 Process according to Claim 7, characterized in that melamine is used as the amino resin former. Process according to Claims 7 to 8, characterized in that sodium sulfamate is used as sulfamate. Process according to Claims 7 to 9, characterized in that the condensation takes place in a molar ratio of 1: 3.0 to 6: 0.3 to 0.8. Process according to Claims 7 to 10, characterized in that the condensation takes place at temperatures between 80 and 100 ° C. Process according to Claims 7 to H, characterized in that the condensation is continued until the viscosity of the 20% aqueous solution of the sample at 20 ° C, measured in a U mm DIN flow vessel, is at least 12 DIN seconds. 13,591 32