FI94974B - Process and compositions for bonding paper - Google Patents

Abstract

The manufacture of sized paper, by adding a sizing agent and an aluminium compound to paper-making stock or by surface-sizing paper with a pre-blend of the agent and the compound, is carried out at a neutral or alkaline pH, typically a pH above 6, and so that the agent and the compound are added simultaneously to the paper-making stock or are applied simultaneously to the paper surface. If the agent and the compound are used as a one-shot pre-blend, this is made on or immediately before use.

Description

94974

This invention relates to paper sizing methods and more particularly to paper sizing using rosin resin-5 s-type sizing compositions at relatively high pH values. This invention also relates to sizing compositions as such for use in carrying out such methods and to the resulting sizing paper products.

Conventional paper sizing methods using rosin resin in either its emulsified or soaped form involve the separate addition of a rosin resin-based sizing composition and an aluminum salt to one or more locations on the wet end of the paper machine.

15 This technique works satisfactorily at pH values, which are usually between 4-6. When the pH is significantly higher than about 6, for example, in the case where chalk is added to the pulp, gluing with this technique becomes irregular and very difficult to control.

In view of these difficulties, when attempting to make glued paper or surface sizing paper already made using a pH above the normal pH range of 4 to 6, it is common practice to use non-rosin resin adhesives, such as those based on alkyl ketene dimers.

Attempts to glue generally at neutral or initial pH values, or to use special aluminum salts (e.g., polyaluminum chloride) in a two-step form in the presence of chalk, have yielded only very poor results.

30 It is also known that if a one-step operation is used, namely a process involving the use of a premix of colophonic resin and an aluminum salt prepared well before the premix is added to the machine, again only momentary control of gluing is possible in an alkaline environment. Such single-step systems, which are used to avoid these difficulties, are described, for example, in pending Patent Application No. 8,712,370 (Publication No.) and also in U.S. Patent No. 4,333,795.

5 It has now surprisingly been found that preparing a premix of rosin-based adhesive and aluminum salt directly on a production line just before it is added to a paper machine results in much better and more controlled rosin resin bonding when the raw material contains chalk or otherwise has a neutral or alkaline pH. Thus, the present invention is based on the unexpected finding that there is a difference in behavior if a mixture of rosin resin and aluminum salt is prepared when actually used or immediately prior to it, compared to known methods in which it is prepared well prior to use.

According to one aspect of the present invention, there is thus provided a method of sizing paper in which the paper is made from a pulp system containing chalk or otherwise neutral or alkaline and thus high pH at which a rosin resin-based sizing and an aluminum compound premixed composition is used or a rosin resin-based sizing composition is added separately but at the same time * 25 and premixed just before the addition at the appropriate selected point on the wet end of the paper machine.

According to a second aspect of the present invention there is also provided a premixed paper sizing composition comprising a rosin resin based adhesive and an aluminum compound and suitable for use in forming or. immediately thereafter. Particular optional but preferred frameworks for the proposed one-step paper sizing composition of the present invention may include the incorporation of a higher than normal amount of aluminum salt, a higher than normal amount of colo-35 resin based adhesive, or the inclusion of at least one polyelectrolyte.

According to a further preferred feature of the process and the composition of the invention, the weight ratio between the rosin resin and the aluminum compound 5 used in carrying out the process and thus present in the single-stage composition on a dry weight basis is between 1: 0.01 and 5. According to a further preferred feature of the invention, the ingredients which are added to the wet end of the paper machine in carrying out the process of the invention, either during operation or as a single-stage premix, include at least one urea-based extender.

In addition to pulp sizing in accordance with the present invention, another aspect encompasses the use of the aforementioned premixed compositions and techniques for surface sizing of already made paper whether or not a rosin-based sizing composition has been used to date in its manufacture. A further aspect of the present invention consists of any paper or paper-like product made by the method of the present invention or made using the paper sizing composition of the present invention.

According to a preferred embodiment of the present invention, the premixed rosin resin-based sizing composition used to practice the present invention may contain, in addition to the rosin resin and the aluminum compound, one or more other additives useful in papermaking, for example to optimize the sizing function of the rosin resin-based component itself. Such other and optional additives include cationic and anionic polyelectrolytes and also cationic starches. The premix may contain, for example, one or more cationic and anionic polyacrylamides, polyethyleneimine, * polydialkyldimethylammonium chloride (DADMAC) or polyamide / epichlorohydrin condensates as well as dicyano-diamide / formaldehyde condensates.

4 94974 In accordance with a further aspect of the present invention, despite the difficulty of using premixed single-stage adhesive products such as those commercially available in the form of products manufactured and supplied by chemical companies, especially under neutral or alkaline pH conditions, modify the above blending technique by optionally adding other aluminum salt and / or polymers so that such premixed commercial products can also be used in accordance with the principles of this invention, thereby achieving better control and efficiency than previously possible with these single step products.

In order to carry out the process of the present invention at the practical level, it is necessary to use some kind of mixing device to control the degree of dispersion of the aluminum salt and rosin resin adhesive, which in turn affects their distribution among the paper fibers, optimizing the gluing efficiency. The mixing device is suitably connected to the wet end of the 20 paper machines and its proper use ensures that the dispersion works by controlling the degree of agglomeration of the fibers in the pulp.

The rosin-resin-based adhesive component used in the practice of this invention, doped into a premix together with an aluminum compound, may be based on rosin resin or modifications thereof before being converted to a stable emulsion form. Thus, for this purpose, resin resin, formaldehyde-treated resin or tall oil resin, fumaric acid-treated resin or tall oil resin, dehydrated resin-like compound resin, treated with maleic anhydride, resin resin or m

In addition, esters or half-esters of any of the aforementioned 5,94974 forms of rosin resin formed using straight-chain or polyhydric alcohols can also be used. A third possibility is to use any suitable mixture of any of the above-mentioned untreated or treated forms of rosin resin, including a dehydrated resin or tall oil resin, together with any one or more of the esters or half-esters just mentioned.

As a further aspect of the present invention, it is possible to use resinous materials other than the rosin resin itself or chemically modified rosin resin compounds. For example, hydrocarbon resins, both aromatic and aliphatic modifications, may be used in an appropriate blend to carry out the papermaking processes of this invention.

Paraffin waxes and microcrystalline waxes can be used in combination with a rosin resin of one of the above-mentioned sizing compositions, or with a resin-based type, depending on the particular use of one or the other wax, depending largely on the properties that may be required in the final paper product.

In addition, any suitable rosin resin-based sizing emulsion derived from any one or more of the aforementioned materials may contain one or more extenders. As an example, urea-based extenders can be used for this purpose. Such extenders are described, for example, in U.S. Pat. Nos. 4,022,634, 4,093,779, 4,141,750, 4,025,354, 4,437,894 and 4,605,445. Any suitable rosin emulsion of rosin-30 may also be extended by emulsion of alkyl ketene dimers prior to premixing with the aluminum compound. with or after. Alkyl ketene dimer emulsions can be stabilized with either cationic starch or cationic or anionic polymers.

According to a second aspect of the present invention, an aluminum compound incorporated into a single-stage premix of the present invention or otherwise used in the paper sizing processes of the present invention is selected from polyaluminum chlorides, aluminum chlorohydrate, aluminum sulfate (paper-5 alum) and any mixture of two or more.

In the practice of this invention, it is desirable to add to its paper sizing composition, when made in a single step form, at least one stabilizer that can take the form of one or more surfactants. Mixtures of stabilizers or surfactants may also be used. A very wide range of possibilities are available with regard to the nature of these materials, which can be anionic, nonionic, cationic or amphoteric.

One special class of stabilized emulsion consists essentially of rosin resin soap and a protective colloid. The rosin resin-based component, namely rosin resin soap, may be sodium, potassium or ammonium soap of rosin resin or modified co-rosin resin together with amine salts of rosin resins or modified rosin resins, for example triins of amines or salts formed using mono-. These stabilizers can be added separately or formed in situ to prepare a rosin resin-based emulsion composition. Colloids that can be used to stabilize the resulting product include casein, starch, soy protein, and cellulose derivatives, with the former being most preferred, as well as certain polymers such as polyvinylpyrrolidone or polyvinyl alcohol. (PVA). The preferred form of the stabilized emulsion consists of potassium or sodium soap of an essential rosin resin or rosin resin derivative and casein as a stabilizing colloid.

According to a further aspect of the present invention, surfactants which can be used in compounding the compositions of the present invention include: (i) salts of sulfonic acids having the general formula:

5 (H ') m - * 0] - 0 (C2H4O) n -CH2-CH-CH2-SO3M

X

wherein R 'represents a hydrocarbon residue having 4 to 18 carbon atoms, m is an integer having a value of 1 or 2, n is an integer having a value of 4 to 25, X represents a hydrogen atom or a hydroxyl group and M represents a monovalent cation and ( (ii) salts of sulfuric acid half-esters of general formula:

15 [R 2 -

2 wherein R represents a hydrogen atom or alkyl groups having 1 to 4 carbon atoms, A represents a straight-chain or branched alkylene group having 2 or 3 carbon atoms, p is an integer having a value of 4.25 and Q is a monovalent cation, including all those compounds described in U.S. Patent No. 4,309,388; (iii) alkyl benzene sulfonates in which the alkyl substituent contains from 8 to 24 carbon atoms, including all compounds described in U.S. Pat. No. 4,157,982; (iv) sulfosuccinate half-esters of a fortified rosin resin of the formula: H (3-m) · H. [(CH2CH2O) n-OC.C2H3SO3Ma.-COOMal. 5-3 and n are on average 4.5-25, including -35 all described in EP-A-159,794; • »949 74 8 (v) compounds having either of the following formulas: 5 ^ 0 (CH 2 CH 2 O) n -SO 3 M +

_R

and IR * -O (CH-CH2O) -so, M + L2 'wherein A represents an alkyl group having 4 to 18 carbon atoms and R' represents an alkyl or alkenyl group containing 4 to 18 carbon atoms and n is an integer having a value of 4-25 including all those described in U.S. Patent No. 4,199,367; (vi) sulfonic succinate salts of ethylene oxide condensates having the general formula: wherein R represents an alkyl group containing from 4 to 18 carbon atoms in which R (CH, CH, O) n is C - CH CH, -CO. atoms and n is an integer from 4 to 25, including all compounds described in U.S. Patent No. 4,203,776; (vii) organic phosphate esters having either of the general formulas: R.O. (CHo-CH - O) 2 z n. o o-x ^ * - o-x 35 and

/ ° X

9,94974 R.O. (CH2-CH2-O) n R.O. (CH2-CH2-O) n 5 and mixtures thereof; wherein R represents an alkyl or alkylphenol, alkenyl or alkaryl group having 5 to 20 carbon atoms, n has a value of 5 to 20 and X represents a monovalent cation or a hydrogen atom.

Dispersant systems formed by a cationic resin can also be used to stabilize the rosin resin dispersions of this invention. Examples of suitable materials are water-soluble polyaminopolyamide / epi-15 chlorohydrin resins, water-soluble alkylene polyamine / epichlorohydrin resins and poly (diallylamine) / epichlorohydrin resins.

In order that this invention may be more fully understood and appreciated, the following examples of the use of the paper sizing methods and compositions of this invention are provided for illustrative purposes only. In the examples, all amounts are by weight unless otherwise indicated. In Example 1, Part A represents the use of the present invention, while Part B represents the use of prior art.

Example 1 Part A

An experimental scale Fourdrinier paper machine was used to make 85 g / m 3 paper at a rate of 16 kg / h of softwood / hardwood sulphate pulp. to which 10% chalk had been added.

«

Premixes were prepared from rosin glue and aluminum salt using a laboratory mixer and fed to the machine just before the headbox.

• · 35 94974 10

The following results were obtained:

Column resin- Polyaluminium- 1 min. Cobb pH stern 2 adhesive; solid chloride (g / m in a box of raw materials / intake-5 dut% lassa) 1.0 0.5 68 7.8 1.0 1.0 29 7.6 1.0 1.5 29 7.6 10 Part B:

For comparison with the exemplary practice in Part A, sheets were prepared using sulfate cellulose containing 10% chalk. The adhesive and PAC were added separately to the pulp and held for 20 minutes 15 before the sheets were made.

The following results were obtained:

Rosin Resin- Polyaluminum- 1 min Cobb pH aft 2 adhesive; solid chloride (equivalent g / m in the box substances / fibers,% in the intake space) 20___ 1.0 0.5 146 7.4 1.0 1.0 156 7.2 1.0 1.5 154 7.3 2.0 0.5 154 7, 4 25 2.0 1.0 144 7.3 2.0 1.5 137 7.2

Example 2

In a commercial paper machine producing envelope paper at a rate of 6.8 t / h with a chalk content ranging from 5.8 to 7.8%, the glue treatment was performed in advance. by mixing free rosin resin glue and alum and «adding the premix to the front of the thick mass headbox. The amount of glue used (dry weight) was 0.45% and the amount of alum used (image weight) was 1.93% throughout the run.

35 11 94974

Time 1 min Cobb Headbox pH

12.30 26 8.0 12.45 20 8.0 5 13.45 20 8.0 13.50 22 7.5 14.25 21 7.7 14.59 21 7.6 15.34 21 7.7 Referring to Example 1 above, it is observed that in Part B, the Cobb values indicate that the sheets were close to the saturation point. Referring to the last three results in Part B of Example 1, twice the amount of rosin resin adhesive calculated as solids percentage of fibers compared to the first three was used, but this caused very little difference in the Cobb values obtained and none of the values obtained in Part B came close to the much better gluing levels obtained. in carrying out the present invention in accordance with Example 1, Part 20A. In particular, the last two results of Example 1, Part A, and Example 2 as a whole give a very satisfactory range of sizing values. In these examples, "in the received state" with respect to polyaluminum chloride means that it contained 10% Al 2 O 2.

Thus, the present invention represents a substantial and surprising advance over previous paper sizing methods and compositions.

1 · «« »

Claims (6)

A method for improving the sizing of paper containing chalk as a filler, wherein a rosin or resin-based sizing agent and an aluminum compound are added to the papermaking pulp at a specified location at the wet end of the paper machine, characterized in that amount of chalk so that the pH is above 6. 2. A patent according to claim 1, which comprises polyaluminum chlorides or aluminum chlorohydrates. 3. A preferred embodiment of claim 1 or 2, having a rotary angle, a rotary head, a rotary head, an aluminum having an aluminum content of 1: 0.01-5. Process according to Claim 1, characterized in that the aluminum compound is polyaluminum chloride or aluminum chlorohydrate. Process according to Claim 1 or 2, characterized in that the weight ratio of the sizing agent to the aluminum compound, based on the dry weight, is 1: 0.01 to 5. 4. An embodiment according to claim 1 or 2, 20 is provided, for example, in the case of ureas based on a drying device. Process according to Claim 1 or 2, characterized in that the premix contains at least one urea-based extender. 5. The present invention relates to a cationic stack, a cationic and anionic polyacrylamide polyacrylamide form, a cationic and anionic polyacrylamide formate, a cationic and anionic polyacrylamide form, a polyethylene glycol formulation Process according to one of the preceding claims, characterized in that the premix contains an additive selected from the group consisting of cationic starches, cationic and anionic polyacrylamides, polyethyleneimine, polydialkyldimethylammonium chloride (DADMAC), polyamide / epichlorohydrin syaanidiamidi / formaldehyde condensate. Process according to one of the preceding claims, characterized in that the sizing agent: is based on rosin or modified rosin selected from the group consisting of rosin, formaldehyde-treated rosin or tall oil resin, fumaric acid-treated rosin, tallow resin, treated rosin or tall oil resin, esters or half - esters of such rosin or modified rosin with straight - chain or polyhydric alcohols. ·· s. ut hui m · - 13 94974 • 1. Förfarande för fätbättrande av limning av pap- per innehällande In the form of an emulsion and an aluminum alloy, a mixture of the same solution and a mixture of paper and paper is also used in the form of a mixture of water. 6. A formulation according to the preceding patent-30, having a base, having a base of rosin or a modifier of rosin, a group consisting of rubber resins, formaldehyde resins, rubber resins or tallow resins, fumar resins dehydrerat rosin, maleinsyrabe-35 handlat gummiharts eller talloljaharts, estrar eller par-tiella estrar av dylikt rosin or ellifier modifierat rosin med rakkedjade eller flervärda alkoholer.