JPH0788639B2 - Papermaking additives - Google Patents

Description

TECHNICAL FIELD The present invention relates to a papermaking additive that is used by adding it during the production of paper or paperboard.

[Prior art]

In the production of paper and paperboard, improving drainage on wires and pressing equipment and improving the yield of fine fibers, fillers, sizing agents, paper strengthening agents, etc. improve paper quality and lower costs. From is extremely important.

For these purposes, conventionally, a papermaking using polyethyleneimine-based resin, polyamide-based resin, Hofmann modified polyacrylamide, copolymer of (meth) acrylamide and cationic monomer, and Mannich modified polyacrylamide as main components. Additives are used.

[Problems to be Solved by the Invention]

However, among the above papermaking additives, the Hoffmann-modified polyacrylamide has a problem that its cationic property decreases with time, and therewith a problem that the above-mentioned effects of improving drainage and retention decrease. The copolymer of cation monomer and cation monomer has a problem that it is economically disadvantageous because the cation monomer is expensive. Further, the polyethyleneimine-based resin and the polyamide-based resin both have a problem that it is difficult to obtain the above-mentioned sufficient effects of improving drainage and yield.

On the other hand, Mannich modified products of polyacrylamide are economically advantageous because amines and formaldehyde used for imparting cationic property to polyacrylamide are inexpensive, and therefore, they are widely used as additives for papermaking. However, it is still not completely satisfactory in terms of effectiveness.

Therefore, the present invention is to provide a papermaking additive containing a Mannich modified product of polyacrylamide, which has a large effect of improving drainage and yield.

[Means for Solving the Problems]

In order to further enhance the effect of the Mannich modified product of polyacrylamide which has been conventionally used, the present inventors have conducted extensive studies, and as a result, acrylamide and / or methacrylamide, a water-soluble unsaturated dibasic acid, and further these A Mannich modified product of polyacrylamide, which has a Mannich modification rate of more than 70% with respect to (meth) acrylamide of an acrylamide copolymer composed of a vinyl monomer copolymerizable with In comparison with the above, it was found that the drainage, the fine fibers, the filler, the sizing agent, the paper-strengthening agent, and the like have a significant effect on the retention, and the present invention has been completed.

That is, the present invention provides (a) acrylamide and / or methacrylamide 50
To 99 mol%, (b) 1 to 20 mol% of water-soluble unsaturated dibasic acid, and (c) Monomer 30 copolymerizable with (a) and (b) above.
In the acrylamide-based copolymer obtained from mol% or less, the above (a)
More than 70 mol% based on the components (d) Formaldehyde and (e) Mannich-modified acrylamide copolymer obtained by reacting an aliphatic secondary amine or an aliphatic secondary amine and an aliphatic primary amine The present invention provides a papermaking additive characterized by:

The acrylamide-based copolymer in the present invention means acrylamide and / or methacrylamide (hereinafter referred to as a monomer (a)) and a water-soluble unsaturated dibasic acid (hereinafter referred to as a copolymerizable monomer) with the monomer (a). , A monomer (b)), or a monomer copolymerizable with the monomer (a) and the monomer (b). , Monomer (c)) is also used as one component of the non-polymerized monomer, that is, the monomer (a),
The copolymer obtained by polymerizing the monomers consisting of (b) and (c) is referred to.

Here, the amount of the monomer (a) to be used is 50 to 99 mol%, preferably 60 to 97 mol%, based on all the monomers, and the amount of the monomer (b) to be used is appropriate. Is 1 to 20 mol%, preferably 3 to 12 mol%, based on the total monomers, and the amount of the monomer (c) used is 0 to 30 mol% based on the total monomers. Molar% is suitable.

Typical examples of the monomer (b) include maleic acid, fumaric acid, itaconic acid and citraconic acid, or their anhydrides, alkali metal salts or ammonium salts. Further, esters that can be hydrolyzed to form such a water-soluble unsaturated dibasic acid can also be used. These may be used alone or in combination of two or more.

In addition, when a typical example of the monomer (c) is shown,
Nonionic vinyl monomers such as styrene, (meth) acrylonitrile, methyl (meth) acrylate, and butyl (meth) acrylate; dimethylaminopropyl (meth) acrylamide, diethylaminopropyl (meth)
A vinyl monomer having a tertiary amino group such as acrylamide, hydrochloric acid, sulfuric acid or acetate of the tertiary amino group-containing vinyl monomer, or methyl chloride, dimethylsulfate or the like to the tertiary amino group-containing vinyl monomer. Cationic vinyl monomers such as vinyl monomers containing quaternary ammonium salts obtained by reacting so-called quaternizing agents such as epichlorohydrin; and unsaturated monobasic bases such as (meth) acrylic acid and crotonic acid Examples thereof include acids, anionic vinyl monomers such as alkali metal salts or ammonium salts of the unsaturated monobasic acids, and these may be used alone or in combination of two or more.

In the present invention, amines are used in the Mannich reaction, and typical examples of the amines include aliphatic secondary amines such as dimethylamine and diethylamine. Further, there is no problem in using a known and commonly used primary amine together.

The Mannich reaction is preferably in the range of more than 70 mol% and 100 mol% of formaldehyde and amines used with respect to the monomer (a) in the acrylamide-based copolymer before carrying out the Mannich reaction. This gives a papermaking additive having excellent storage stability, drainage improving effect, and yield improving effect.

Of course, when the Mannich reaction is carried out, there is no problem even if one of formaldehyde and amines is added in excess so long as the storage stability and economy are not impaired. The Mannich reaction can be carried out according to a known and commonly used method.

〔Example〕

Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the examples. Also, in the following,% means% by weight unless otherwise specified.

[Example 1] In a 1000 ml four-necked flask equipped with a stirrer, a thermometer, a reflux condenser and a nitrogen gas inlet tube, 30% maleic anhydride aqueous solution 9.80 g, 50% acrylamide aqueous solution 137.93 g, isopropyl alcohol 10.84 g. And 405.39 g of water were collected and charged, and then the pH was adjusted to 4.5 with 30% aqueous sodium hydroxide solution.
Then, the temperature of the reaction solution was raised to 65 ° C. while purging oxygen by passing nitrogen gas into the system.

Then, while continuing stirring, 2.28 g of a 5% ammonium persulfate aqueous solution was added as a polymerization initiator to proceed the polymerization reaction, and 1 hour and 2 hours later while maintaining the same temperature, 1.14 g of a 5% ammonium persulfate aqueous solution was added. Added.

Five hours after the start of polymerization, non-volatile components (hereinafter NV
Is abbreviated. ) Was 13.0%, a Brookfield viscosity at 25 ° C (hereinafter abbreviated as viscosity) was 4,600 cps, and a stable aqueous solution of a acrylamide copolymer having a pH of 4.7 was obtained. Incidentally, maleic anhydride in an aqueous solution,
It was immediately hydrolyzed.

After that, the copolymer aqueous solution was cooled to 40 ° C. and, while continuing stirring, 87.30 g of a 50% dimethylamine aqueous solution and 37
% Formaldehyde aqueous solution 78.65g and added, further 30%
After adding 5.29 g of sodium hydroxide aqueous solution and adjusting the pH to 10, hold at 40 ° C for 2 hours to obtain a stable Mannich modified product with NV of 15.2%, viscosity of 6,100 cps and PH of 10.2. It was Hereinafter, this is abbreviated as a papermaking additive (A-1).

Examples 2 to 13 and Comparative Examples 1 to 4 In the same manner as in Example 1 except that the raw material components shown in Table 1 were changed, the respective acrylamide copolymers and then the Mannich modified products of the respective copolymers were used. Got

However, for adjusting the amount of isopropyl alcohol and pH
The amount of 30% sodium hydroxide aqueous solution was changed and used each time.

Table 1 shows the property values of the Mannich-modified acrylamide copolymer aqueous solutions obtained in the above Examples and Comparative Examples. In the table, the Mannich modification rate (%) is the mole% of formaldehyde and amines used with respect to the monomer (a) of the acrylamide-based copolymer as described above, HCHO mole%, DMA Mol% is all monomers (a) + (b) + of the acrylamide copolymer
It is a mol% with respect to (c).

Application Examples 1 to 13 and Comparative Application Examples 1 to 4 Canadian standard standard obtained from waste newspaper
A sulfuric acid band [Al ₂ was added to a 0.3% concentration slurry of beaten pulp having a freeness (hereinafter abbreviated as CSF) of 164 ml.
(SO ₄ ) ₃ · 14H ₂ O] was added to pulp 0.5% (based on dry weight of dry pulp; the same applies below), and the pH of this pulp slurry was adjusted to 15% sulfuric acid or 30% sodium hydroxide aqueous solution. The content was adjusted to 6.0, and then 0.02% of the papermaking additives obtained in Examples 1 to 13 and Comparative Examples 1 to 4 were added to the pulp and the mixture was stirred for 1 minute.

A portion of the pulp slurry thus obtained was used to measure CSF to compare the drainage effect, and another portion to compare the retention effect of fine fibers, Tappi Vol. 56, No. 1.
The suspension contained in a fixed amount of the obtained filtrate was weighed by a filtration test using "Dynamic Drainage Jar" described on page 46 of No. 0 (1973). . Below, SS
Expressed as a value.

Application Examples 14 to 26 and Comparative Application Examples 5 to 8 Similar to Application Examples 1 to 13 and Comparative Application Examples 1 to 4 except that a sulfuric acid band was added to pulp 1.5% and the pH of the pulp slurry was adjusted to 4.5. The operation was performed and the CSF value and SS value were measured.

Table 2 shows the results of the above-mentioned application examples and comparative application examples.

Application Examples 27 to 39 and Comparative Application Examples 9 to 12 A pulp slurry having a concentration of 0.3%, a pH of 7.5 and a CSF of 393 ml, obtained from waste corrugated cardboard, and a neutral sizing agent alkyl ketene dimer emulsion to pulp 0.07%.
Add, stir for 2 minutes, and then add each of the papermaking additives obtained in Examples 1-13 and Comparative Examples 1-4 to pulp.
0.05% was added and the mixture was further stirred for 1 minute. Using a part of the pulp slurry thus obtained, the CSF value and the SS value were measured in the same manner as in Application Examples 1 to 13 and Comparative Application Examples 1 to 4, and the rest were produced by Noble and Wood Co., USA. The paper was made with a handmade paper machine and then dried at 110 ° C. for 1 minute with a drum dryer to obtain a handmade paper with a weight of 85 ± 2 g / m ² . After that JIS for each handmade paper JIS
According to P-8122, "Steckigt Sizing" and JIS P
“Specific burst strength” was measured according to −8112.

Application Examples 40 to 52 and Comparative Application Examples 13 to 16 A pulp slurry having a concentration of 3.0%, a pH of 6.5 and a CSF of 393 ml obtained from waste corrugated paper was added with a sulfuric acid band (0.5% to pulp) and stirred for 2 minutes, Then, dilute 10-fold with diluting water whose pH has been adjusted to 6.5 in advance, and then add 0.05% of pulp to alkenyl succinic anhydride emulsified with cationized starch as a sizing agent and stir for 2 minutes, Then, 0.05% of pulp was added to each of the papermaking additives obtained in Examples 1 to 13 and Comparative Examples 1 to 4 to obtain 1
After stirring for a minute, the same as Application Examples 27-39 and 9-12
Measurement of CSF value, measurement of SS value, measurement of "Steckigt sizing degree", and measurement of "specific burst strength" were performed.

Application Examples 53 to 65 and Comparative Application Examples 17 to 20 To a pulp slurry having a concentration of 3.0%, a pH of 4.5 and a CSF of 393 ml obtained from waste corrugated paper, 0.3% of anionic polyacrylamide as a paper strength agent was added to pulp. And stir for 2 minutes, then add a sulfuric acid band and rosin emulsion as the sizing agent to pulp at 1.5% and
After adding 0.1% and stirring for 2 minutes, the mixture was diluted 10-fold with diluting water whose pH was adjusted to 4.5 in advance, and then Examples 1 to 13 were used.
And 0.05% of pulp to which each of the papermaking additives obtained in Comparative Examples 1 to 4 was added and stirred for 1 minute.
27-39 and Comparative Application Examples 9-12
The F. value, SS value, "Steicht sizing degree" and "specific burst strength" were measured.

The results of Application Examples 27 to 65 and Comparative Application Examples 9 to 20 are summarized in Table 3.

Application Examples 66 to 78 and Comparative Application Examples 21 to 24 BKP with L / N = 4/1 and 3 of beaten pulp with CSF of 310 ml
20% heavy calcium carbonate powder to pulp was added to the slurry with a concentration of 10%, and then cationized starch was added to the pulp.
Add 0.5% and stir for 2 minutes, then dilute 10-fold with diluting water whose pH has been adjusted to 7.5 beforehand, add 0.15% of alkyl ketene dimer emulsion to pulp, and stir for 2 minutes. , Examples 1 to 13 and Comparative Examples 1 to
Each of the papermaking additives obtained in 4 above was added 0.025% to pulp and stirred for 1 minute.

A portion of each of the pulp slurries thus obtained was used to describe in Application Examples 1-13 and Comparative Application Examples 1-4.
The SS value was measured, and the remainder was used to describe the "Steckigt sizing degree" described in Application Examples 27 to 39 and Comparative Application Examples 9 to 12,
"Ash content" according to JIS P-8128 was measured except that it was incinerated at 500 ° C.

Application Examples 79 to 91 and Comparative Application Examples 25 to 28 Instead of cationized starch, a sulfuric acid band was used for pulp.
Application Example 66 ~ except that 0.5%, cationized starch emulsified alkenyl succinic anhydride was added to pulp 0.15% instead of 0.5% alkyl ketene dimer emulsion
In the same manner as in 78 and Comparative Application Examples 21 to 24, the SS value, the “Steckigt sizing degree” and the “ash content” were measured.

Application Examples 92 to 104 and Comparative Application Examples 29 to 32 3 of beating pulp with BKP of L / N = 4/1 and CSF of 310 ml
% Slurries to pulp were added 20% talc to pulp, then sulfuric acid bands and rosin emulsion were added to pulps 1.5% and 0.5% respectively and stirred for 2 minutes, pre-adjusted to pH 5.0. It was diluted 10 times with the above-mentioned dilution water, and 0.025% of each of the papermaking additives obtained in Examples 1 to 13 and Comparative Examples 1 to 4 was separately added to pulp, and then Application Examples 66 to 78 and Comparative Examples were compared. Same as application examples 21-24
The SS value, "Sekicht sizing degree" and "ash content" were measured.

The results of Application Examples 66 to 104 and Comparative Application Examples 21 to 32 are summarized in Table 4.

From the above results, application examples 1-26 are drainage, application examples 27-52
Is mainly due to the yield effect of sizing agents, application examples
In 53 to 65, in addition to the sizing degree, the effects of the specific bursting rate can be understood by the yield effect of the paper strength agent.

〔The invention's effect〕

According to the present invention, acrylamide and / or acrylamide of an acrylamide copolymer obtained by copolymerizing acrylamide and / or methacrylamide with a water-soluble unsaturated dibasic acid and further a monomer copolymerizable therewith at a predetermined ratio. Since it is possible to provide a papermaking additive containing a Mannich-modified acrylamide copolymer obtained by performing a Mannich modification reaction of more than 70 mol% to methacrylamide,
When papermaking is carried out using this, the drainage property on the wire and the press machine can be improved, and the yields of the fine fibers, the filler, the sizing agent, the paper strengthening agent, etc. can be improved. Then, for example, the sizing degree is improved by improving the yield of the sizing agent, and the paper strength is enhanced by improving the yield of the paper strength agent. Such drainage and retention effects can be achieved by using a water-soluble unsaturated monobasic acid instead of the water-soluble unsaturated dibasic acid, or by using the Mannich modification reaction as described above.
It cannot be obtained when the content is less than or equal to mol%, and the present invention using these as constituent elements shows a remarkable effect which is not available in the conventional art.

As a result, the paper quality can be improved and the paper manufacturing cost can be reduced.

Claims (4)

[Claims] 1. (a) 50 to 99 mol% of acrylamide and / or methacrylamide, (b) 1 to 20 mol% of water-soluble unsaturated dibasic acid, and (c) copolymerized with (a) and (b) above. Possible monomers 30
In the acrylamide-based copolymer obtained from mol% or less, the above (a)
More than 70 mol% based on the components (d) Formaldehyde and (e) Mannich-modified acrylamide copolymer obtained by reacting an aliphatic secondary amine or an aliphatic secondary amine and an aliphatic primary amine An additive for papermaking, which is characterized by: 2. A method according to claim 1, wherein the component (c) is 0.
The additive for papermaking according to the item. 3. The papermaking additive according to claim 1 or 2, wherein the component (a) is 60 to 97 mol% and the component (b) is 3 to 12 mol%. . 4. The method according to claim 1, wherein the component (b) is at least one water-soluble unsaturated dibasic acid selected from the group consisting of maleic acid, fumaric acid, itaconic acid and salts thereof. The additive for papermaking according to any one of item 3.