FI57116B - ANVAENDNING AV HYDROFOB STAERKELSE VID PAPPERSFRAMSTAELLNING - Google Patents

Description

ri ADVERTISEMENT ΚΠΛΛΖ MK [Β] 11 UTLAGG NINGSSKRI FT 5/116 ^ Patent ooddelat ^ T ^ (51) Kv.ik. «/ int.ci. · C 08 B 31/0 ^ D 21 H 3/28 FINLAND — FINLAND (*) Paunttihaltamu · - Rttwitameknlng 1372/73 (22) HakamUpllvl - Aniftknlnpdaf l6.05.73 (23) AlkupUvl —GUtl | h * t * daj ΐ6.05 · 73

(41) Tullut Julki * · ksl - Bllvlt off «ntlig i7.ll.7U

Patent and Rakicter Board · .... ...,. ,, .., _ '. (44) Date of issue of the publication. -

Patent- och ragistarstyralsan Arwttkan Utl * | d och utl. * Krlft * n published 29.02.80 "(32) (33) (31) Requested« tuolkau »—Begird prlorltat (71) KemaNobel AB, Box 11065, 100 6l Stockholm, Sweden-Sweden (SE) ^ (72) Karin Ulla Elisabet Helmer, Solna, Berit Ingegärd Simonsson, Solna,

Sweden-Sweden (SE) (7U) Oy Borenius & Co Ab (5U) Use of water-repellent starch in papermaking - Användning av hydrofob stärkelse vid pappersframställning

The invention relates to the use of water-repellent starch as a grinding additive in papermaking or as a paper surface sizing agent for making paper water-repellent. The invention relates in particular to the use of a water-repellent starch containing groups of the general formula R 2

N - C

R 2 - in which the formula represents an organic water-repellent hydrocarbon group having 8 to 40 carbon atoms, and R 1 represents a lower alkyl group or has the same meaning as.

Starch is widely used in papermaking. Adding starch to the grinding increases the strength of the finished paper. The polar hydroxy groups of starch form fiber-starch-fiber bonds that are stronger than pure fiber-fiber bonds.

The desired degree of water repellency of starchy papers is usually obtained by separately adding pine resin glue or synthetic water repellents to the milling. This limits e.g. grinding 2 57116 pH selection and grinding temperature.

By using water-repellent starch, the pH can be selected from a wider range, and if, moreover, a cationic starch having quaternary groups is selected for use, the degree of water repellency achieved becomes completely independent of the pH of grinding.

The presence of water-repellent groups can, as is known, inhibit hydrogen bonds, which lowers the strength of the finished paper. It has surprisingly been found that the number of alkyl chains added to the starch according to the invention is oriented in such a way that these chains give the paper good water-repellent properties but do not affect the strength properties of the paper.

In the case where starch is used for surface sizing, the procedure is in some cases to improve the surface strength of the paper and to adjust the resistance of the paper to water and inks. According to the invention, when water-repellent starch is used, the surface strength does not deteriorate, but both good surface strength and good water-repellent properties are obtained by adding a single additive.

The water-repellent starch used according to the invention for making paper water-repellent contains 0.05 to 30% by weight of groups having the general formula

N - C

R 2 represents an organic, water-repellent hydrocarbon group having 8 to HO carbon atoms, and R 2 represents a lower alkyl group or represents the same as R 1 and the starch is prepared by reacting it with carbamoyl chloride substituted by R 1 and R 2.

The organic water-repellent hydrocarbon groups R 1 and R 2 that have been found to be useful in imparting water-repellent properties to a cellulosic fibrous material are those in which the water-repellent group is higher alkyl having at least about 8 carbon atoms, such as Decyl. , undecyl, dodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, heptadecyl, octadecyl, tetracosyl and pentacosyl, and higher alkyls having up to about 40 carbon atoms, if desired, although groups having about 12 to 30 carbon atoms are best used. as well as corresponding alkenyl groups having from about 8 to about 40 carbon atoms, some examples of which include decenyl, tridecenyl, hepta-decenyl, octadecenyl, eicosenyl, tricosenyl, etc., further aralkyl, alkaryl and alkyl-substituted cycloalkyls having at least 8 carbon atoms, and examples include 4-tert-butylphenyl, octyl ifenyl, dinophenyl, dodecylphenyl, tri-decylphenyl, pentadecylphenyl, octadecylphenyl, benecosylphenyl, nonylcyclopropyl, dodecylcyclobutyl, tridecylcyclo-pentyl, octecyclohexyl, tetradecylcyclohexyl, pentadecyl, pentadecyl, pentadecyl; alkylcycloalkyl groups having non-interfering inert substituents. Examples of inert substituents include carboalkoxy, alkyloxy, aryloxy, arylalkyloxy, keto (carbonyl), tert-amide groups, etc. Examples of radicals which must not be present in more pronounced water-repellent groups include hydroxyl groups, primary and secondary groups. halogens, amide groups containing amide-hydrogen and carboxyl groups or other acidic groups. The person skilled in the art will of course know which groups are to be used in these compounds in order to avoid harmful side reactions.

and R 2 generally represent a straight, branched or polycyclic alkyl group having 12 to 30 carbon atoms.

For example, a water-repellent starch can be prepared by contacting an aqueous starch slurry with compounds that may or may not be dispersed in any suitable manner.

It is also conceivable to contact the starch with a solution or dispersion of the compounds.

As an example of a suitable procedure for rendering starch water-repellent, it is shown that an aqueous dispersion of the compounds is prepared and this dispersion is added to the aqueous starch slurry. Dispersion „57116 is prepared using an emulsifier of an anionic, cationic or nonionic nature or a mixture thereof.

A cationic emulsifier is suitably used so that the dispersed compounds can be satisfactorily contacted with the starch so that the reaction can take place with good efficiency, suitably using 0.1 to 10% by weight of emulsifier, based on the weight of the dry starch. Examples of suitable cationic dispersants include polyethyleneimine, polyalkylene polyamide resins, cationic starch, and the like.

Carbamoyl chlorides per se have a certain cationic activity, and thus a certain retention capacity relative to starch. This eliminates the need for any other special retention agent for some uses. However, when the compounds are added to an aqueous suspension of starch, in most cases a cationic emulsifier is suitably used together with the compounds. Examples of certain types of retention agents which have a good effect together with these compounds are quaternary ammonium compounds, e.g. amine hydrochlorides containing at least one alkyl group having 8 to 22 carbon atoms, e.g. dimethyldistearylamine chloride or dimethylstearylaminohydrochloride.

Examples of types of starch which contain water-repellent groups or which can be made water-repellent in accordance with the invention include natural starch such as potato starch, corn starch, tapioca starch, etc., as well as modified starches of the above-mentioned natural products, e.g. with cationizing agents, e.g. diethylaminoethyl chloride hydrochloride, glycidyltrimethylammonium chloride, phosphonium compounds. The starch may be in gelatinized or non-gelatinized form.

Due to the high reactivity between starch and carbamoyl chlorides, the water repellent process can be carried out directly in paper mills, suitably at the stage where the starch is heated to about 80-120 ° C to paste the starch before it is added to the paper or cellulose fibers. The reactivity of carbamoyl chloride is improved to some extent in the case of the presence of an alkyl chloroformate during the reaction. The alkyl chain suitably contains 8 to 20 carbon atoms.

The amount of carbamoyl chloride waste in starch can vary widely, depending on the intended use of the starch. The reaction between the carbamoyl chloride and the starch can be carried out in the presence of 0.05 to 30% by weight of carbamoyl chloride, based on the weight of the dry starch. When, for example, water-repellent starch is used as a grinding additive in papermaking, the amount of carbamoyl chloride residues must be in the range of 8 to 30% by weight, while amounts of 0.1 to 8% by weight give a good effect when gluing the surface of the paper.

The following embodiments illustrate the invention in more detail. Percentages and parts refer to percentages by weight, i.e. parts by weight, unless otherwise stated.

Example 1

12.5 g of potato starch and 150 ml of water were mixed in the flask at room temperature, followed by the addition of a dispersion of 1.12 g of distearylcarbamoyl chloride in 100 ml of water. The temperature was raised to 90 ° C for 2 hours, after which the mixture was allowed to cool. The nitrogen content was determined according to Kjelldahl and the concentrations obtained showed an efficiency of the reaction of 83%.

Example 2

The preparation of Example 1 was repeated using cationic starch. Instead of the above amounts, 1.69 g of distearylcarbamoyl chloride and 0.19 g of cetyl chloride formate in 100 ml of water were added. The nitrogen content was determined according to Kjelldahl and the concentrations obtained represented 80% efficiency of the reaction.

Example 3

The preparation of Example 2 was repeated. Instead of the above amounts, 2.26 g of distearylcarbamoyl chloride in 100 ml of water were added. Nitrogen concentrations were determined according to Kjelldahl and represented a reaction efficiency of 70%.

6 57116

Example 4

It was performed in exactly the same manner as in Example 1, but without the addition of distearylcarbamoyl chloride.

Example 5

It was performed entirely according to Example 2, but without the addition of distearylcarbamoyl chloride and cetyl chloroformate.

Example 6

From the water-repellent starch derivatives of Examples 1 to 5, 5% aqueous solutions were prepared, which were added to an aqueous suspension of cellulose fibers. The paper sheets were prepared in a laboratory type sheet forming machine. The sheets were dried for 40 minutes at 60 ° C and cured for 30 minutes at 105 ° C. The humidity was equilibrated for 4 hours at 20 ° C to a relative air humidity of 65%, after which the Cobb number was determined according to Scan-P 12:64. Untreated starch was used as a reference product. The results are shown in Table 1.

7 571 1 6 d ιΗ

•B

m + J o U Q) ^ O O zt X-> · X I Ο- CM CO j- ·

ΤΟ LO CM

_ * O O O *, 10 T- CM CO * O 1 T- LO to

O CO LO

.λ * O O LO *.

to T- c ^ * cm co * oo 1

T— LO LO

O CM CO., LTD

rt Λ o O CO *

Is · »CM CO * CO |

r- LO LO

O CM C **> o ** CO * ro Λ O 00 · »CO go

w ^ LO CM T— «O LO

T- CO ΤΟ * r *** Λ ro * OC * "» r »r- °° tc ^ cmt- lo lo ooo oo LO« ^ r OT— Λ 00 -ί CM O CM CM LO; f T- lo r- co cd Λ CM λ Λ o O * CD ^ CM O Γ '** CM CM LO rt, -

LO JO

O * rt * rt

CSJ * O O Λ CM

^ T-r ^ CMCM LO LO ^

O CM O

O *> t Λ

rs LO LO r »CO., LTD

t— f- J cm lo lo en ^ σ lo o O CM *

rt O O CO., LTD

t— CM CO LO lO cd O Ή im eee wc ma) oi m SvH e λ to ω m rl 41 I Ή LO ^ + j <D + Jrtffi omk>, CO OX +>> CL Oi 'U Aarnio (0 e ! XG · Η O e .3 I 0) 4j> UVPC CO ^ 3 <D · Η · Η, * ω T- mma) a) ω § x ηό, ^ ο rd'H-μο to to <<to > vH ea

O XX fcem. * Χι-i P -g ä · Η >>: rö -H

λ; ΟΧ >> O. 0) -P d P Ή X ΰ B g 0 P m X .n PP -n CO PPP d JS Ä fl m · —I ex pa) + j «3 om Iti X) rH to a) a>>; m to h *> s: m ρ p e, c, ccL i md x + J-Hd> d a) -h cotm-H-Hd dg a>. P. A οιμ-η.γη m o ω -h 3¾ d m m m »3 λ‘ h .ti 3 · η>! oj 3

H Ά CU JEXOji-o bH O äo, CL, O

CJ

Example 7 8 5711 6

5% aqueous solutions were prepared from the starch of Examples 1, 2, 3. These were applied with a laboratory brush to the surface of untreated sheets of paper. The amount added was kept constant = 3.0 g of dry starch per square meter of paper surface. The untreated starch according to Examples 4, 5 was used as a control. The sheets were dried at room temperature and cured for 30 minutes at 105 ° C. The moisture was leveled for 4 hours at 20 ° C and 65% relative humidity, after which the surface strength was determined.

Results: _3

Sample according to the example Surface strength, dyn / cm 10 5 216 1 224 4 202 2 222 3 252

Example 8

The procedure of Example 1 was repeated except that 1.48 g of dilaurylcarbamoyl chloride was added to the mixture instead of distearylcarbamoyl chloride. Nitrogen content was determined according to Kjelldahl from an experiment taken after 2 hours and the result showed an efficiency of 74%.

Example 9

The procedure of Example 1 was repeated except that 2.70 g of methyl tetradecylcarbamoyl chloride from the distearyl carbamoyl chloride state was added to the mixture. Nitrogen content was determined according to Kjelldahl from an experiment taken after 2 hours and the result showed an efficiency of 74%.

Example 10

The procedure of Example 1 was repeated except that 2.00 g of methyl stearylcarbamoyl chloride was added to the mixture instead of distearyl carbamoyl chloride. The nitrogen content was determined according to Kjelldahl 9,571 1,6 from an experiment taken after 2 hours and the result showed an efficiency of 77%.

Example 11

From the water-repellent starch derivatives of Examples 8 to 10, 5% solutions were prepared in water. These solutions were added to an aqueous suspension of cellulose fibers. The pH of the slurry was 7 and the temperature was 20 ° C. Paper sheets were prepared in a laboratory-type sheet forming machine. The sheets were dried for HO minutes at 60 ° C and cured for 30 minutes at 105 ° C. The humidity was equalized for H hours at 20 ° C to a relative air humidity of 65%, after which the Cobb number was determined according to Scan-P 12; 6H. , as well as dry break length and burst factor according to Mullen. The results are shown in Table 2.

Table 2

Water repellent starch according to the example_8_9_10

Amount of starch added as a percentage of the dry weight of the fibers

Cobb number (g / m2) 23.5 26.0 22.0

Dry break length (km) 5.30 5.58 5.50

Burst factor 52 56 5H

Amount of carbamoyl chloride as a percentage of the dry weight of starch

Example 12

In a glass flask, 12.5 g of potato starch and 150 ml of water were mixed cold and 0.1 g of distearylcarbamoyl chloride (dry) in 100 ml of water was added as a dispersion. The temperature was maintained at 90 ° C for 2 hours, after which the mixture was cooled. The starch derivative thus obtained, containing 3.6% of carbamoyl chloride by dry weight of the starch, was used in the same manner and in the same amount as in Example 11 to obtain a sheet with a Cobb number of 65.0.

Example 13 57116 1 o

In a glass flask, 12.5 g of cationic starch and a dispersion of 0.20 g of distearylcarbamoyl chloride in 150 ml of water were mixed. The temperature was maintained at 90 ° C for 1 hour, after which the reaction mixture was cooled to room temperature. The pH was kept constant at 7 with NaOH.

Example 14

The experiment of Example 13 was repeated using only 0.10 g of distearyl carbamoyl chloride.

Example 15

5% aqueous solutions were prepared from the starch derivatives of Examples 13 and 14. These were applied with a laboratory brush to the surface of untreated sheets of paper. The sheets were dried at room temperature and cured for 30 minutes at 105 ° C. The humidity was equalized for 4 hours at 20 ° C with a humidity of 65%, after which the Cobb number was determined according to SCAN-P 12:64. The results are shown in Table 3.

Table 3

Water repellent starch according to the example_1J_1J_14_14

Amount of starch added per paper area g / mz 6969

Carbamoyl chloride as a percentage of the dry weight of starch 1.6 1.6 0.8 0.8

Cobb number g / m2 20.0 16> 0 36, o 21> 0

Claims (4)

11 57116 Use of water-repellent starch as a pulp grinding additive in papermaking or surface sizing of paper to render paper water-repellent, wherein the water-repellent starch used is starch containing 0.05 to 30% by weight of groups of the general formula R 1, wherein in the formula means an organic water-repellent hydrocarbon group having 8 to 40 carbon atoms, and R 2 represents a lower alkyl group or the same as R 1, which starch is prepared by reacting it with carbamoyl chloride substituted by R 1 and R 2. Use according to Claim 1, characterized in that the substituent is an alkyl group having 12 to 30 carbon atoms and R 2 is a lower alkyl group or an alkyl group having 12 to 30 carbon atoms. 1. Application of hydrophobic starch for hydrophobing of paperboard for the production of paper or paperboard for the production of paper paints with hydrophobic starch ash in the form of a mixture of 0,05 to 30% by weight of a group of R1 / N - H , a hydrophobic flask group having 8 to 40 carbon atoms and R2 is a substituent on the same side of the R1 and a starch-containing genome by reaction with carbamoyl chlorides having a substituent R1 and R2.