A METHOD FOR CONTROLLING THE DEPOSITION OF STICKIES IN PULPING AND PAPERMAKING PROCESSES

A method for controlling the deposition of stickies in pulping and papermaking processes comprises adding to fibre pulp or stock an additive comprising an organo-modified siloxane comprising units of the formula: [R1 aZbSiO(4-a-b) /2]n in which each R1 is independently selected from a hydrogen atom, an alkyl, aryl, alkenyl, aralkyl, alkaryl, alkoxy, alkanoyloxy, hydroxyl, ester or ether group, and each Z is independently selected from an alkyl group substituted with an amine, amide, carboxyl, ester, or epoxy group, or preferably at least one or more groups -R2- (OCpH2p)q (OCrH2r)S-R3; wherein n is an integer greater than 1; a and b are independently 0, 1, 2 or 3; R2 is an alkylene group or a direct bond; R3 is a group as defined for R1 or Z above; p and r are independently an integer from 1 to 6; q and s are independently 0 or an integer such that 1 = q + s = 400; and wherein each molecule of the organo-modified siloxane contains at least one group Z. The organo-modified siloxane is preferably a hydroxyl- or alkyl- endcapped linear polydimethylsiloxane, in which 5 to 18 mole percent of silicon atoms are substituted by Z groups of the formula -R2- (OCpH2p) q (OCrH2r)S-R3, in which p is 2, r is 3 and q and s are independently 10 to 20, R2 is an alkylene group having from 1 to 6 carbon atoms or a direct bond, and R3 is a hydrogen atom or a hydroxyl, alkoxy, ester or ether group. Un método para controlar la deposición de adhesivos en procesos de producción de PASTA y de fabricación de papel comprende adicionar a la pasta o al reservorio de fibras un aditivo que comprende un siloxano con modificación orgánica que comprende unidades de la fórmula: [R1aZbSiO (4-a-b)/2]n en la cual cada R1 se selecciona independientemente entre un átomo de hidrógeno, un grupo alquilo, arilo, alquenilo, aralquilo, alcarilo, alcoxi, alcanoiloxi, hidroxilo, éster o éter, y cada Z se selecciona independientemente de un grupo alquilo sustituido con una amina, amida, carboxilo, éster o epoxi, o preferiblemente al menos uno o más grupos -R2- (OCpH2p)q(OCrH2r)S-R3; en donde n es un número entero mayor que 1; a y b son independientemente 0, 1, 2 ó 3; R2 es un grupo alquileno o un enlace directo; R3 es un grupo como se ha definido para R1 o Z anteriores; p y r son independientemente un número entero de 1 a 6; q y s son independientemente 0 o un número entero tal que 1 = q + s = 400; y en el que cada molécula de siloxano con modificación orgánica contiene al menos un grupo Z. El siloxano con