JP2617433B2 - Paper Strengthening Agent - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to a paper strength agent excellent in paper reinforcing effects in papermaking systems which plenty of electrolytic material coexist.

[0002]

In recent years, insufficient forest resources, which is a raw material of paper, there is an increasing use ratio of old Gion as an alternative. This
When waste paper such as
Was dissolved in papermaking water, the papermaking water is the electrolyte material gradually accumulates by being recycled I accompanied the closed system of the papermaking process, a large amount of electrolyte material for papermaking water
May be included. In addition, there is a case in which the river water containing sea water and a large amount of electrolyte material, the industrial water must be used in papermaking water.

[0003]

However, this is not the case.
Paper using water containing a large amount of electrolyte material
In addition, the active ingredient of the dry paper strength enhancer that increases the dry paper strength
And widely used polyacrylamide-based
When using paper strength agents containing limers, sufficient paper strength
There is a problem that the enhancement effect cannot be obtained. The eyes of the present invention
The target is paper-based odor using water containing a large amount of electrolyte substances.
To provide a paper strengthening agent exhibiting an excellent paper strength enhancing effect even.

[0004]

Means for Solving the Problems The present invention, in order to de <br/> determine the above problem, tables in (1), (a) the following general formula [1]
0.5 to 10 mol% of a monomer to be

Embedded image (Wherein, R ₁ is H or CH ₃ , R ₂ and R ₃ are each an alkyl group having 1 to 2 carbon atoms, n is an integer of 2, 3 or 4, and X ⁻ is an anionic counter ion. ) (B) from α , β-unsaturated dicarboxylic acids and salts thereof
At least one monomer of the group 2-5 mol%, (c) acrylamide and / or methacrylic ami de
Obtained from monomer components containing 8 5 to 99.3 mol%
The present invention provides a paper-strength enhancer comprising a water-soluble copolymer as an active ingredient . Also, the present invention
The monomers represented by the general formula [1] of (2) and (a)
A paper-strengthening agent of the above (1) represented by the following chemical formula:

Embedded image The α, β-unsaturated dicarboxylic acids of (3) and (b)
The paper strength enhancer according to the above (1) or (2), which is an acid,
Things .

Next, the present invention will be described in detail. Paper of the present invention
The force enhancer is a simple composition containing the above (a), (b) and (c).
Water-soluble copolymer obtained from monomer component as active ingredient
Things. Represented by the general formula [Chemical Formula 1] of the above (a)
Monomer is an amide-based cationic monomer.
As a specific material belonging to the general formula [1], di-methylcarbamoyl <br/> Le aminopropyl methacrylamide, quaternized compound according benzyl chloride and dimethyl amino propyl acrylamide. Among these, the above chemical formula [Formula 2]
Quaternized products by benzyl chloride di methyl aminopropyl acrylamide represented are preferred. Simple substance of the above (b)
Body is an anionic monomer, including Ma maleic acid,
Fumaric acid, itaconic acid, alpha, such as citraconic acid, beta-unsaturated dicarboxylic acids and their sodium salts, potassium salts, ammonium salts, and of these
Also, itaconic acid and its salts have the most excellent effects. Of course, these may be used in combination . these
Therefore, as an anionic monomer, α, β-unsaturated
At least one of the group consisting of the sum of dicarboxylic acids and salts thereof
It can be said that one monomer is used. (A) above,
In addition to (b), the acrylamide and / or
Or methacrylamide is used as a copolymer component
But in addition to these three components, a cationic monomer such as dimethylaminoethyl methacrylate may be used in combination with the component (a), also, to be obtained in addition to these
The amount of styrene to the extent that does not impair the water solubility of the water-soluble copolymer, acrylonitrile may be used hydrophobic monomers such as ethyl acrylate in the copolymer component. (A) above,
Aqueous solution obtained from monomer components containing (b) and (c)
These monomers and the necessary
A known and commonly used chain transfer agent such as isopropyl alcohol, allyl alcohol, sodium allyl sulfonate, and sodium hypophosphite is appropriately used in the aqueous solution charged with the above other monomer, and the monomer concentration is 5 to 30. Weight percent, at a polymerization initiation pH of 3 to 6, a radical polymerization initiator such as ammonium persulfate, sodium persulfate or potassium persulfate, or a redox initiator obtained by combining these persulfates with a reducing agent such as sodium bisulfite. In addition, it is manufactured by heating and stirring at 35 to 95 ° C. for 1 to 10 hours in the presence of an inert gas . The water - soluble copolymer thus obtained is 300 to 100,0 in a 15% by weight solution.
00cps (25 ℃, Brook field viscosity) rather goodness those having a viscosity of, in particular 800~30,000cp
It s is preferred. When the viscosity is extremely low (low molecular weight) less than 300 cps , the water-soluble copolymer is effectively synthesized.
Min to a paper strengthening agent has poor paper strength enhancing effect, also, 10
Extremely high viscosity (high molecular weight) greater than 000 cps
In the case of, have a water-soluble copolymer for disturbing the formation of the paper to which the water-soluble copolymer has a paper causing excessive aggregation
Paper strength enhancing agent to active ingredient are Once also the adverse effect of such reduction in paper strength
You.

[0006] The above (a), (b),
Water-soluble copolymer obtained from monomer component containing (c)
The amount of the monomer of the component (a) in obtaining the body, 0.5
10 mol% is preferred. If this is less than 0.5 mole
Its fixing force to the pulp water-soluble copolymer is insufficient, also, not only more than 10 mol% and a carbamoyl group to Tsutsumi subjected <br/> (meth) copolymerization ratio of acrylamide is reduced the (a) for multi amount of hydrophobic groups by a benzyl group component will be present the water-soluble copolymer and Se
Since it inhibits the hydrogen bond with the cellulose fiber, the paper strength is rather reduced . Further, α and β of the component (b)
- at least one unsaturated dicarboxylic acid and salts thereof,
In a paper strength enhancer containing the obtained water-soluble copolymer as an active ingredient
Aluminum sulphate (bansulfuric acid sulphate), which is widely used as a cation moiety in copolymers or other papermaking chemicals
Are those anions sites provide for forming the aluminum ions and ionic bonds de), the amount used 0.2
5 mol% is preferred , and less than 0.2 mol% is insufficient to form this ion bond, and more than 5 mol%.
The paper-strength enhancer using the obtained water-soluble copolymer is undesirable because it tends to disperse pulp, particularly fine fibrous pulp, and adversely affect the pulp yield and the like . α , β
-Of the unsaturated dicarboxylic acids, itaconic acid is most preferred . Monomer component containing the above (a), (b) and (c)
<br/> strength agents of the present invention to the resulting water-soluble copolymer as an active ingredient from the on pulp dry weight of the aqueous dispersion of the pulp, used by adding from 0.05 to 4 wt% Is done . That
Addition location is good pulp is any one as long as the place is a state of well-dispersed in water in the papermaking process. Use of a known sizing agent, paper strength enhancer, drainage improver, or the like at the time of papermaking does not hinder at all.

The water-soluble copolymer according to the present invention is a cationic
Site and an anion site, and the cation site is
Establishes electrostatic ionic bonding with negatively charged pulp.
With this, the fixing power to pulp is excellent, and its copolymerization
The bodies form an ionic bond between their cation and anion sites.
Aluminum sulfate for papermaking
When aluminum is used, aluminum ions fixed to the pulp
And the anion site of the water-soluble copolymer bind,
Contains (meth) acrylamide component
Hydrogen bond-forming ability of moyl-based pulp with cellulose fiber
It is considered that the force exerts a paper strength enhancing effect. At this time,
If a large amount of electrolyte material is present in the paper system,
Is prevented by this ionic bond and its water-soluble copolymerization
Although the fixation of the body to the pulp is prevented, the above component (a)
Hydrophobic benzyl group is the hydrophobic part of pulp cellulose fiber
That can easily adsorb to the surface, thus exhibiting paper strength enhancing effects
it is conceivable that. At this time, α, β-
Without the use of unsaturated monocarboxylic acids, α, β-unsaturated
When a carboxylic acid is used, the resulting water-soluble copolymers
Bonding with the cation site in the
When using a combination of
The bond becomes stronger, and because it is a bifunctional acid,
Even if the copolymerization ratio in the water-soluble copolymer of
As many anion sites as possible
(Meth) acrylic resin having hydrogen bond forming ability
Because the copolymerization ratio of amide can be increased, α, β-
Better paper strength than using unsaturated monocarboxylic acid
It is considered to be. Within the range that does not impair this excellent performance
Α, β-unsaturated monomers such as acrylic acid and methacrylic acid
Nocarboxylic acid may be used in combination .

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the following embodiments.

[0009]

EXAMPLES show embodiments and applications of paper strength agent of the present invention below, but the invention is not limited only to the embodiment of the present invention Yoko. In the following, “%” means “% by weight” unless otherwise specified.

Example 1 A stirrer, a thermometer, a reflux condenser, and a nitrogen gas inlet were provided.
663.1 deionized water in a 1 liter four-necked flask
g, 503.2% acrylamide aqueous solution 243.2 g(95 m
%), 3-acrylamidopropyldimethylbenzyl
80% aqueous solution of ammonium chloride19.08 g
(3 mol%), 4.68 g of itaconic acid(2 mol%), 2
% Aqueous sodium hypophosphite solution 12.95 g,
Then, to pH 4.0 with a 15% aqueous sodium hydroxide solution.
After adjustment, introduce nitrogen gassoRaise the temperature to 60 ° C and exceed 5%
4.11 g of aqueous ammonium sulfate solution was added to initiate the polymerization reaction.
Started. After that, keep the temperature at 75 ° C for 3 hours to complete the polymerization reaction.
I let it. The polymer thus obtained has a non-volatile content.15.6
%, 25 ° C, Brookfield viscosity7400cps
Was a clear aqueous solution ofHTo be. What
In addition, the weight (g) of each component is calculated from the mol% in ().
Table 1 shows mol% in parentheses.

[0011]

[Table 1]

Example 2 A polymerization aqueous solution K was obtained by carrying out the same polymerization reaction as in Example 1 by mixing the constituent monomer components shown in Table 1. In order to obtain the same viscosity, the amount of the chain transfer agent was appropriately changed. Table 1 shows the physical properties of the copolymers obtained in the examples. Each monomer a _{1 in} Table 1 and Table 2 (for a comparative example described later)
_{a 2 b 1 b 2 b 3} c 1 c 2 d 1 d 2 d
₃ is as follows. a ₁ .beta.-methacryloyloxyethyldimethylbenzylammonium chloride (compound of the following formula 3 )

[0013]

Embedded image

[0014] a ₂ · · · 3- acrylamidopropyltrimethylammonium dimethyl benzyl ammonium chloride (the compound of the formula 2]) Ride _b 1 · · · itaconic acid b ₂ · · · maleic acid b ₃ · · · acrylic acid c ₁ · · acrylamide c ₂ · · · methacrylamide d ₁ · · · dimethylaminoethylmethacrylate d ₂ · · · 4 grade product by _CH 3 Cl in the _{d 1} (beta-methacryloyloxyethyl trimethylammonium chloride) _d 3 · · · dimethyl Aminopropyl acrylamide

[0015]

[Table 2]

Comparative Examples 1 to 7 Polymerization was carried out in the same manner as in Example 1 in accordance with the composition of the constituent monomer components shown in Table 2, and copolymer aqueous solutions a to g were obtained .

[0017] Only with acrylic acid _{b 3} instead of Comparative Example 8 (b) component, its
Other components according to the composition of the constituent monomer components shown in Table 2,
The polymerization reaction was carried out in the same manner as in Example 1, and the aqueous copolymer solution h was used.
I got Also in the case of the above comparative example, the amount of the chain transfer agent is appropriately changed.
I went there. Table 2 shows the physical properties of the copolymer obtained in Comparative Example.

[0018] In papermaking systems comprising respond examples 1 a large amount of the electrolyte material, tap water / sea = 8/2 (conductivity as papermaking water in order to determine paper strength agent of the present invention exhibit what effect Degree 820
0

(Equation 1) , Hardness 1300 ppm) and Canadian Standard Freeness (hereinafter abbreviated as CSF) 399
After adding 2.0% of a sulfuric acid band (based on dry weight of pulp, the same applies hereinafter) to 2.5 ml of an aqueous dispersion of 2.5% corrugated cardboard Kogi, each of the copolymers obtained in Examples and Comparative Examples was added. Each was added 1.0%. 0.33 of this pulp slurry
%, And paper making (pH 5.0 at the time of paper making) with a hand-making device made by Noble & Wood, followed by drying with a drum dryer at 110 ° C. for 1.5 minutes to obtain a basis weight of 82.
± 2 g / m ² handmade paper (I) and basis weight 165 ± 3 g
/ M ² of paper (II). The obtained handmade paper was conditioned at 20 ° C. and a relative humidity of 65% for 24 hours, and then “specific burst strength” was obtained for handmade paper (I) and handmade paper (II) was obtained. Measured "specific compressive strength" and "plane compressive strength". Table 3 shows the results. The measurement of physical properties in each application example was performed according to the following method. In addition,
In the table, "no addition" means that the above copolymer was not added
It is. Specific burst strength ··· JIS P-8112 Specific compressive strength ··· JIS P-8126 Specific plane compressive strength ··· Japan Tappi Paper pulp test method No. According to 29-78 "Testing method of plane compressive strength of core for corrugated cardboard", humidity measurement was performed for 24 hours in a constant temperature and humidity room at a relative humidity of 65% and a temperature of 20 ° C after corrugation. Break length JIS P-8113

[0019]

[Table 3]

It is apparent from Table 3 that the paper strength enhancer of the present invention exhibits an excellent paper strength enhancing effect in a system containing a large amount of an electrolyte substance.

Application Example 2 In order to clarify the effect of the paper-strength enhancer of the present invention in a system containing a large amount of an electrolyte substance as the closing of the paper-making process progresses, various salts (water) for paper-making water are used. Prepare salt-containing tap water containing Note 1) and use it.
Using 383 ml of SF corrugated cardboard, paper was made in the same manner as in Application Example 1, and the paper was measured. Table 4 shows the results. From the table, it is clear that the paper strength enhancer of the present invention exhibits an excellent paper strength enhancing effect even in a papermaking system in which a large amount of salt has accumulated. Note 1) Salt-containing tap water The following salts are contained in tap water 101 (liter). _{Na 2 SO 4 6.8g CaCl 2 5.0g} MgCl 2 1.7g K 2 SO 4 0.6g conductivity 1900

(Equation 2) Hardness 630ppm

[0022]

[Table 4]

Application Example 3 In order to clarify the effect of the paper strength enhancer of the present invention in a papermaking system using unbleached kraft pulp, 532 ml of CSF 532 ml of unbleached kraft pulp was used. 0.5% aqueous dispersion (slurry pH 10.5, conductivity 820)

(Equation 3) ), 0.3% of a sulfuric acid band and 0.4% of each of the copolymers obtained in Examples and Comparative Examples were added. This pulp slurry was diluted to 0.33%, and paper was made using a hand-making apparatus manufactured by Noble & Wood (pH at paper making: 8.
0) then 110 ° C. in a drum drier, and dried for 1.5 minutes, hand-made paper having a basis weight ^{75 ± 2g / m 2 (I} ) and basis weight 150 ± 2g / ^{m 2} of handsheets (II) I got
The obtained handmade paper was conditioned at 20 ° C. and a relative humidity of 65% for 24 hours, and then the handmade paper (I) had a “break length”, and the handmade paper (II) had a "Specific compressive strength" was measured. Table 5 shows the results. From the table, it is clear that the paper strength-enhancing agent of the present invention also exhibits an excellent paper strength-enhancing effect even in unbleached kraft pulp containing a large amount of lignin soda and the like.

[0024]

[Table 5]

Application Example 4 In order to clarify the effect of the paper strength enhancer of the present invention on gypsum board base paper, pulp (Note 2) obtained from a gypsum board base paper manufacturer was used. To a 0.5% aqueous dispersion, 1.0% of a saponified rosin sizing agent (PFP manufactured by Dick Hercules Co., Ltd.) and 2.5% of sulfate were added, and then each of the samples obtained in Examples and Comparative Examples was added. 0.3% of each copolymer was added. The pulp slurry was diluted to 0.33% and mixed with Noble &
Paper was made with a wood hand-making device, and the pH was adjusted to pH 5.
5) Then, drying was performed at 110 ° C. for 1.5 minutes with a drum dryer to obtain a handmade paper having a basis weight of 160 ± 2 g / m ² .
The obtained handmade paper was conditioned at 20 ° C. and a relative humidity of 65% for 24 hours, and then “tear length” and “specific burst strength” were measured. Table 6 shows the results. It is clear from the table that the paper strength enhancer of the present invention also exhibits an excellent paper strength enhancing effect on gypsum board base paper. Note 2) Pulp is a mixture of used newspaper and used magazine paper (CSF 160 ml), and the properties of this pulp slurry are as follows. pH 6.6 conductivity 770

(Equation 4) Total hardness 430 ppm Total acidity 25 ppm Total alkalinity 290 ppm Sulfate ion 510 ppm Chloride ion 27 ppm Sodium ion 64 ppm Calcium ion 130 ppm Potassium ion 22 ppm

[0026]

[Table 6]

Application Example 5 In order to clarify the effect of the paper-strength enhancer of the present invention in an actual system in which the papermaking process is closed, a paperboard manufacturing company near a city where the closed process has advanced has been carried out. Using the obtained pulp (Note 3), 1.0% of a sulfuric acid band was added to the 2.5% aqueous dispersion, and then 0.4% of each of the copolymers obtained in Examples and Comparative Examples was added.
added. This pulp slurry was diluted to 0.33%, and paper was made using a hand-making device manufactured by Noble & Wood (pH 4.5 at the time of paper making).
0 ° C., to obtain a 1.5 minutes dried basis weight of 80 ± 2g / ^{m 2} of handsheets (I) and basis weight 160 ± 2g / ^{m 2} of handsheets (II). The obtained handmade paper was conditioned at 20 ° C. and a relative humidity of 65% for 24 hours, and then handmade paper (I)
Was measured for "specific burst strength", and for handmade paper (II), "specific compressive strength" was measured. Table 7 shows the results. It is clear from the table that the paper strength-enhancing agent of the present invention exhibits an excellent paper strength-enhancing effect even when a pulp containing a large amount of an electrolyte substance used in a papermaking company is used. Note 3) The pulp is used corrugated paper (CSF 416 ml), and the properties of this pulp slurry are as follows. pH 4.4 conductivity 3340

(Equation 5) Total hardness 1250 ppm Total acidity 555 ppm Total alkalinity 0 ppm Sulfate ion 440 ppm Chloride ion 38 ppm Sodium ion 42 ppm Calcium ion 68 ppm

[0028]

[Table 7]

From the above Tables 3 to 7, it is apparent that the paper strength enhancers of the examples of the present invention show excellent paper strength enhancing effects in a system containing a large amount of an electrolyte substance. It can be seen that this is superior to the case where acrylic acid is used.

[0030]

The paper strength enhancer of the present invention comprises the above (a) to
Water-soluble copolymer obtained from monomer component containing (c)
Since the body is used as an active ingredient , an excellent paper strength enhancing effect can be provided in a papermaking system containing a large amount of an electrolyte substance , and instead of the component (b), α, β-unsaturated monoca
Water-soluble copolymer obtained in the same manner using rubonic acid
Demonstrates better paper strength than when used as an active ingredient
I can .

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-62-299599 (JP, A) JP-A-58-60095 (JP, A) JP-A-55-137298 (JP, A) 1353 (JP, B1) JP 1-49839 (JP, B2)

Claims (3)

(57) [Claims] (A) a compound represented by the following general formula [1]
0.5 to 10 mol% of the monomer (In the formula, R ₁ is H or CH ₃ , R ₂ and R ₃ are each an alkyl group having 1 to 2 carbon atoms, n is an integer of 2, 3 or 4, and X ⁻ represents an anionic counter ion .) (b) alpha, or β- unsaturated dicarboxylic acids and salts thereof
At least one monomer of the group consisting of 2-5 mol%, (c) acrylamide and / or methacrylic ami de
Obtained from a monomer component containing 8 5 to 99.3 mol%
Paper strength agent characterized in that the water-soluble copolymer as an active ingredient that. 2. The paper-strengthening agent according to claim 1, wherein the monomer of ( a) represented by the general formula [1] is represented by the following chemical formula [2] . Embedded image 3. The paper-strengthening agent according to claim 1 , wherein the α , β-unsaturated dicarboxylic acid of ( b) is itaconic acid .