JPS61146900A - Production of printing paper - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing printing paper that has good printability during offset printing and is suitable for reuse as waste paper.

[Conventional technology]

In general offset printing, when printing, the paper comes into contact with the dampening water coming from the plate, so its strength decreases and the surface peels during printing [hereinafter referred to as wet blistering], and the paper absorbs the dampening water. If this is poor, printing defects such as insufficient ink acceptance (hereinafter referred to as ink receptivity) may occur.

For this reason, it is necessary to take measures such as lowering the printing speed and lowering the viscosity of printing ink. However, the printing speed and print quality are lower than that of K.

In order to improve this drawback, a so-called wet paper strength enhancer is added to the paper for the purpose of imparting water resistance strength to the paper.

[Problem that the invention seeks to solve]

However, improving the water resistance of paper comes with drawbacks in other aspects. In other words, in the paper manufacturing process, it is common practice to reuse defective loss paper (hereinafter referred to as waste paper) as raw material (hereinafter referred to as recovery of horizontal paper) that occurs in the process, but if it is water resistant, it can be submerged in water. The re-disintegration properties of paper deteriorate, and the time, power, energy, chemicals, etc. required for this re-disintegration increase.Also, when such paper is used, waste paper generated during printing and bookbinding, and even waste paper after use. The same inconvenience as above occurs when paper is used again as a raw material for paper.Therefore, increasing the water resistance of paper is effective for printing, but it is difficult to recover waste paper and reuse waste paper. Unfavorable.Especially in recent years, the depletion of wood resources has become a problem, and collection of waste paper and reuse of waste paper have been called for from the perspective of resource conservation, but due to the above problems, it has not always been carried out sufficiently. The current situation is such that it is difficult to say that there are any.

In view of these circumstances, it is an object of the present invention to produce paper that has fewer problems such as the occurrence of wet picks during offset printing, and has good disintegration properties when the horizontal paper is collected and reused as waste paper.

[Means for solving problems]

While investigating the printability of paper by adding urea formaldehyde polymer particle aggregates, the present inventor discovered that the above aggregates and a specific wet paper strength enhancer17) + [i
The present invention was achieved by discovering that it is possible to balance printability and disintegration properties in combination.

That is, in the present invention, for dry pulp in pulp slurry,
At least 0.5 to 20% by weight of urea formaldehyde aggregate (hereinafter referred to as weight% unless otherwise specified) and 0.05% of epichlorohydrin-modified polyamide polyamine resin.
This is a method for producing printing paper, which is characterized in that papermaking is carried out by adding 1.2 chloride.

The aggregate of urea formaldehyde polymer particles used in the present invention is preferably an aggregate of polymer particles in which each individual particle has an average particle size of α05 to α5 μ and an average aggregate size of 1 to 15 μ. . Such a urea formaldehyde polymer particle aggregate can be easily produced by any known method. Thus, for example, urea-formaldehyde polymer particle aggregates may be obtained using a one-step or two-step process, in which case the polymer particles are produced with any molar ratio of urea to formaldehyde. More specifically, the two-step process first forms a water-soluble precondensate of urea and formaldehyde and then cures the water-soluble precondensate in the presence of a suitable curing catalyst and at elevated temperatures. By doing so, an aggregate of polymer particles is formed. Alternatively, in the case of a one-step method, all components and additives used in the reaction are added first, and the reaction proceeds directly to the formation of aggregates of polymer particles. In each case, the resulting urea-formaldehyde polymer particle aggregates are neutralized and washed with water to remove free formaldehyde, or prior to neutralization, urea, ammonia, ammonium salts, sulfites, or sulfites are reacted to remove free formaldehyde. After neutralization, the urea formaldehyde polymer particle aggregate is recovered into a cake by filtration or centrifugation, or dried by conventional methods such as spray drying, further air drying, and other contact and convection drying. When the aggregate of urea formaldehyde polymer particles is used in the form of a cake or in the form of a slurry by redispersing it in water,
Before forming into a cake, it is pulverized to adjust the average aggregate diameter to preferably 1 to 15 μm, more preferably 2 to 10 μm. When an aggregate of urea-formaldehyde polymer particles is obtained in a dry state, it is pulverized after drying to adjust the average aggregate diameter to preferably 1 to 15 microns, more preferably 2 to 10 microns. The P solution obtained by the above filtration or centrifugation is
It is used as raw material water or adjustment water in the previous process.

The curing catalyst iC that can be used in the production of the aggregate of urea formaldehyde boron 1J mer particles used in the present invention can be any acidic catalyst such as sulfuric acid, phosphoric acid, hydrochloric acid, nitric acid,
Included are moderately acidic organic acids having values such as formic acid, sialic acid, maleic acid, succinic acid and chloroacetic acid and the like. Furthermore, sulfamino acids or formulas: RNH, SO,
Water-soluble ammonium hydrogen sulfate of H (wherein is hydrogen, an alkyl group, a cycloalkyl group, a hydroxyalkyl group, an aralkyl group, or an aryl group) can also be used.

Water-soluble ammonium hydrogen sulfate is methyl ammonium hydrogen sulfate, methyl ammonium hydrogen sulfate, hydroxyethylammonium hydrogen sulfate, am water f.

These include phenylammonium, benzyl ammonium hydrogen sulfate, etc.

In the production of the urea-formaldehyde polymer particle aggregate used in the present invention, a water-soluble initial condensate of urea and formaldehyde before particle formation is added to a water-soluble organic polymer having a protective colloid function in order to form particles with a preferred particle size. Alternatively, it is advantageous to add it to a mixed aqueous solution of urea and formaldehyde. The water-soluble organic polymers having a protective colloid function include starch, gelatin, glue, gum tragacanth, gum arabic, natural substances such as carboxymethyl cellulose,
Alkali metal salts such as sodium and potassium carboxymethylcellulose, methylcellulose, ethylcellulose, β-hydroxyethylcellulose, modified natural products such as alkali metal salts of alginic acid, polyvinyl alcohol, polyvinylpyrrolidone, polymers of acrylic acid or methacrylic acid, and their Alkali metal salts, copolymers of maleic acid and styrene or butylene, or salts thereof;
These include vinylpyridine homopolymer and copolymer salts. The amount of protective colloid used depends on the type, but is generally about 0.1 to 10%, preferably 0.5 to 5 N, based on the weight of the urea and formaldehyde reactants.

Furthermore, the advantageous production of the urea formaldehyde polymer particle aggregate used in the present invention will be explained in detail.

Usually, the molar ratio of urea and formaldehyde is 1=1 to 1:
A water-soluble precondensate of urea and formaldehyde, which is No. 2, is used as an intermediate raw material, which has a total concentration of urea, formaldehyde and other additives of about 20-75 cm, a temperature of about 60-100 °C, and a pH value of about 5. ~9 and can be obtained in about 10 minutes to 4 hours. The protective colloid used is polyvinyl alcohol or carboxymethyl cellulose (IJ) salt, which can be added at any point during the production of the water-soluble initial mesh of urea and formaldehyde. In the next step, the initial condensate containing the protective colloid is prepared from room temperature to
Under stirring at a temperature of approximately 100° C., a solution of sulfuric or sulfamic acid is added until gelation occurs. Next, the aggregates are coarsely pulverized using a pelletizer or a hammer mill to a size of 1 to 2 inches, and then water is added while stirring to form a slurry having a concentration of urea formaldehyde particle aggregates of 5 to 10 inches. Subsequently, it is neutralized with an aqueous alkali solution such as aqueous ammonia or caustic soda, and then passed through a pulverizer to preferably
After pulverizing the aggregates to a size of 15μ, more preferably 2 to 1oμ, they are dehydrated in a filtration dehydrator to obtain a cake of urea formaldehyde polymer particle aggregates.

The epichromehydrin-modified polyamide polyamine resin (hereinafter referred to as "PA resin") used in the present invention is already known (Japanese Patent Publication No. 55-5547,
5-27855, Special Publication No. 52-11715).

Usually 1 mole of polyalkylene polyamine such as ethylenediamine, diethylenetriamine, triethylenetetramine, 3-azahexane-1,6 diamine, 4,7-cyazadecane-1,1o diamine and 0 mol of aliphatic dihydrochloric acid such as geltaric acid, adipic acid, and speric acid. 1.0 to 1.0 at a reaction temperature of 100'C to 250C using .9 to 105 mol.
A dehydration reaction was carried out for 8.0 hours, and this was made water-solubilized to form PAM.
An aqueous solution of polyamide polyamine, which is an intermediate raw material for PA resin, is obtained.

In this case, urea is used as a part of aliphatic dihydrochloric acid to make a polyurea polyamide polyamine, or caprolactam is used as a part of the peripheral component of a polyalkylene polyamine and an aliphatic dibasic acid to make a polyamide polyamine. Aqueous solutions can likewise be used as intermediate raw materials for PAMPA resins. Next, epichlorohydrin is added in an amount of 5 to 2.5 times the mole of amine contained in the aqueous solution of polyamide polyamine, and the total nonvolatile content is 5 to 50 cm and the temperature is 60 to 90'C. When the reaction takes 8.0 hours and reaches a non-volatile content concentration of 5% and a Pulckfield viscosity of 10 to 100 centipoise at 25°C, it is treated with a mineral acid such as phosphoric acid, sulfuric acid, hydrochloric acid, or nitric acid while cooling. Neutralization yields PAMPA resin.

In the present invention, the amount of the urea formaldehyde polymer particle aggregate added to the dry bulb is 0.5 to 20%, preferably 1 to 17%.

If it is less than 0.5 inch, the wet pick and ink receptivity in offset printing will be insufficient, and if it exceeds 20%, the wet pick will deteriorate.

The amount of PAFv[FA resin added to the dry pulp in the present invention is 0.05 to 1.2, preferably 0.05 to 1.2.
It is 1 to 0.8%. The amount of PAMPA resin added is 0.0
If it is less than 5 inches, wet vic is insufficient and PA
If the amount of MPA resin added exceeds 1.2%, it becomes difficult to recover waste paper and repulp it for reuse (hereinafter referred to as disintegration).

The printing paper of the present invention is newspaper roll paper, printing paper A, B, 0
, D. Includes printing paper such as gravure paper, printing paper, and other paper types used for day-colored printing that requires opacity.

These papers are made from softwood (N material), hardwood (L material) bleached kraft pulp (KP), and sulfide pulp (
sp), biochemical pulp (SOP), chemical ground pulp (0GF), thermomechanical pulp (TMP)
, refiner ground pulp (RGP), ground pulp (GP), deinked waste paper pulp (DIP), and the like are used.

These pulps are used in various combinations depending on the required physical properties of the paper type to be made. These /< loops are usually beaten with 7 ainer, stored in a machine chest, diluted with a fan pump, and made into paper using a paper machine. Main additives such as sizing agents, aluminum sulfate, and fillers are usually added to the pulp slurry in the process from the finer to the fan pump, but in the production of the printing paper of the present invention, the mourea formaldehyde polymer particle aggregate The PAMPA resin beam is added to the pulp slurry in the process between the finer and the fan pump. Preferably, a mixing box is installed just before or after the machine chest and the mixture is added there. The urea formaldehyde polymer particle aggregate to be added is diluted with water to 5 to 109 g, and PA
It is preferable to use the MPA resin diluted with water to 0.5 to 5% from the viewpoint of uniform dispersion and uniform mixing in the pulp slurry. The amount of these additives can be determined by continuously adding a predetermined amount to the dry equivalent flow rate of the pulp slurry in the addition step. Sizing agent, aluminum sulfate, filler,
When PAMPA resin is added, the preferred order of addition is the sizing agent, aluminum sulfate, and PAMPA resin, but it is generally preferable to add the additive with a low fixing rate first.

Incidentally, inorganic fillers such as talc, clay, calcium carbonate, etc. may be used as long as the object of the present invention is not impaired, and polyacrylamide-based and starch-based dry paper strength enhancers may be used in combination.

The printing paper of the present invention is manufactured using a Fourdrinier paper machine, a twin-wire paper machine, or similar paper machines, and then passes through a press heart, a dryer part, and a calender. Water-based polymers or emulsions such as starch-based, polyacrylamide-based, polyvinyl alcohol-based, styrene-maleic acid-based, etc. are applied singly or in combination of two or more to improve surface strength, size, and other functions. Sometimes.

0 effect] In multicolor printing in offset printing, we often see examples in which colors are printed in the order of indigo, red, and yellow. However, when the ink color part is printed, the plate on which the colors of indigo, red, and yellow are printed is There is dampening water on the body, and the dampening water is transferred to the indigo, red, and yellow parts onto the paper at the same time as the ink is printed. When the indigo color is to be printed next, dampening water is transferred onto the paper surface in other areas.

Of the indigo, red, and yellow to which the ink is transferred after the dampening water is transferred, the dampening water is transferred most often (three times) to the paper surface where yellow is printed. Therefore, the paper surface on which yellow is printed has the greatest decrease in paper strength due to water. Wet pick occurs when the paper strength decreases and the surface strength is less than the tack strength of the ink. When printing at high speed, the ink will be transferred (printed) almost immediately after the dampening water is transferred to the indigo, red, and yellow areas, but if the dampening water that was transferred just before is transferred to the paper surface layer. If the oil-based ink remains transferred without being absorbed, it will be washed away by the dampening water and will not be transferred to the paper. Therefore, ink transfers better to paper that absorbs dampening water at a faster rate and in a larger amount, which is usually referred to as having better ink receptivity.) It is considered to be one of the printability factors that enable high-speed printing and high-quality printing. ing.

Now, PAMPA resin is well known and used as a wet strength agent for paper. It is generally believed that PAMPA resin covers the hydrogen bonding areas between pulp fibers, reducing the rate of water penetration and preventing water from easily penetrating into the hydrogen bonding areas and breaking the hydrogen bonds. . Therefore P.A.M.
If paper containing PA resin is soaked in water for a long time, the water will penetrate into the hydrogen bonds and the hydrogen bonds will be broken, reducing the strength of the paper and making it almost completely water resistant. The difficulty in collecting waste paper is that water penetrates into the hydrogen bonding parts quickly (it is said that recovery is easy when the pulp fibers disintegrate quickly.
A state where the rate of water permeation into the hydrogen bonding portion is slow and the rate of disintegration of pulp fibers is slow, as in the case of using PA resin, is said to be difficult to recover. Therefore, in paper with a large amount of PAMPA resin added, the rate of water permeation into the hydrogen bonding portion becomes slow, making it difficult to recover the paper. On the other hand, reducing the amount of PAMPA resin added makes it easier to recover waste paper, but the wet strength decreases.

On the other hand, urea formaldehyde polymer particle aggregates have a large surface area (the aggregates, which are secondary particles, can absorb a large amount of water or oil. Therefore, printing paper made of pulp to which urea formaldehyde polymer particle aggregates have been added) Even if dampening water is transferred to its surface, the aggregate of urea-formaldehyde polymer particles absorbs it quickly, reducing the amount of dampening water that penetrates into the hydrogen bonds between pulp fibers. The ability of the urea-formaldehyde polymer particle aggregate to absorb quickly improves the ink receptivity of printing ink, and even if the amount of PAMPA resin, which is a wet paper strength enhancer, is added, the resulting printing paper has a high wet viscosity. It is thought that it will have strength and as a result, it will be easier to collect waste paper.

〔Example〕

The present invention will be described in detail below with reference to Examples, but the present invention is not limited in any way by these Examples.

In the following, all parts refer to parts by weight, except for those relating to whiteness, white paper opacity, and post-print opacity. In addition, various measurements and calculation methods were performed according to the following procedures.

・Whiteness was measured using a Hunter whiteness meter using a blue filter.

- White paper opacity was measured according to JIS (P-8158).

- Post-print opacity was determined according to J, TAPP''A Paper Pulp Test Method A45-84.

・Wet pick strength during offset printing was measured with Toyo Ink 8MX using an RI tester (printing aptitude tester manufactured by Mei No Seisakusho).
Offset printing was performed using a tack grade of 10 to 15 and dampening water, and the peeling state of the surface was observed and evaluated, with the best score being 10 points and the worst being 1 point.

・Ink adhesion during offset printing is conducted in the same way as the wet pick strength test method except that the ink tack grade is lowered, and after printing, the ink transfer is measured using a Macbeth ink densitometer. The amount was measured.

・Difficulty in collecting waste paper: 2g of collected paper is approximately 1cm long.
Cut into pieces of x 1 cm in size, and if they have not been desintegrated, stir for an additional 2 minutes, repeat stirring and observation until they are completely disintegrated, and determine the difficulty of collection based on the total time required for complete disintegration. Show degree.

Production Example 1 After dissolving 20.00 parts of water and 0.525 parts of sodium salt of carboxymethyl cellulose (trade name Celogen F-3H) by Dai-Kogyo Seiyaku Co., Ltd. in a flask, a 37% formaldehyde aqueous solution was added. Add 18.24 parts and heat to 70° C. with stirring, and at the same time adjust the pH to 15 with an aqueous caustic soda solution. Next, add 9 parts of urea and heat to 70°C.
The condensation reaction was carried out for 2.0 hours to obtain a urea formaldehyde initial condensation reaction product. This initial condensation reaction product was cooled to about 45°C, and 0.46 parts of 95% sulfuric acid was added to 15 parts of water.
Immediately and uniformly mix with the solution diluted with 73 parts. about 10
It solidifies after a few seconds, at which time the temperature of the reaction mixture rises to 61°C. Then hold at about 60"C for 1 hour.

Next, this solidified material is coarsely divided into particles with a size of 1 to 2 grains using a cutter granulator, and 100 parts of water is added to form a slurry.
Neutralize to pH 7.5 with 20% caustic soda aqueous solution. The obtained slurry was pulverized in a pulverizer, filtered and dehydrated to obtain 60.2 parts of a white cake-like substance. A part of this is heated to 105℃
After drying with hot air for 2 hours, the concentration of the urea formaldehyde polymer particle aggregate in the cake was measured, and it was found to be 20.
1% and 12.10 parts of aggregate (A) was obtained. The average particle diameter of the aggregates obtained was 0.2 μm as measured from an electron micrograph, and the average diameter of the aggregates was 5.1 μm as measured and calculated using a Coulter counter.

The urea formaldehyde polymer aggregate obtained in this example is referred to as UP-1.

Production Example 2 119 parts of adipic acid and 84 parts of diethylenetriamine were placed in 11 flasks equipped with a cooler and a thermometer, and the temperature was raised while replacing the air with nitrogen gas, followed by a dehydration reaction at 180°C for 5 hours. . Thereafter, water was added thereto and cooled to obtain 500 parts of a polyamide polyamine aqueous solution. The concentration of this aqueous solution was 155.5%. Next, 217 parts of water and 150 parts of epichlorohydrin were added to this, and 5
The temperature was raised to 5°C, a reaction was carried out for 5.5 hours, and the pH was adjusted by adding 110 parts of 20% hydrochloric acid. The thus obtained epichlorohydrin-modified polyamide polyamine resin (hereinafter referred to as PAMPA-1) had a pH of 4.5 and a concentration of 30.
．． At 0%, the Pulckfield viscosity was 80 centipoise at 25°C.

Example 1 Freeness (Hereinafter, the freeness is expressed in Canadian Standard Freeness) From 300ml of N, BKP 55g, RGP 20% with a freeness of 190g, TMP 20% with a freeness of 1801nl, and DIP 25% with a freeness of 170d. 20.0 parts of bone-dry blended pulp and 2000 parts of water were dispersed in a desinching grater for 2 minutes, and 2 parts of a 5% aqueous solution of a saponified partially maleated rosin was added as a sizing agent.* 12(SO,), 18N (6 parts of an aqueous solution of aluminum sulfate with a concentration of 5% as 20, PAM
PAMPA resin aqueous solution 4 with a concentration of 1% using PA-1
1 part and 6 parts of a 7% concentration urea formaldehyde polymer aggregate dispersion using UP-1 were added at 1 minute intervals with stirring to obtain 0.0 parts of PAMPA resin per weight of bone-dry pulp.
．． 2% and urea formaldehyde polymer aggregate 0.7
A blended pulp slurry to which H was added was obtained.

Next, paper was made using a square sheet machine to obtain 6Ic9/d.
After pressing for 15 minutes, the material was dried by passing it through a drum dryer with a surface temperature of 115±5° C. for 3 minutes. Subsequently, the paper was passed through a calender of 7 to 9/d twice and seasoned for 24 hours in a constant temperature and humidity chamber at a humidity of 65 degrees and a temperature of 21 degrees Celsius to obtain Example 1 paper with a basis weight of 459/rrl. The printed paper was measured for whiteness, white paper opacity, post-print opacity, wet pick, ink receptivity, and waste paper recoverability, and the results are shown in Table 1.

Examples 2 to 5 The amount of UP-1 used in Example 1 was 0.7% to the pulp, but it was 2.0%, 7%, and 15.0%.
Examples 2, 3, 4 and 5 papers with a basis weight of 459/rl were obtained using the same method and operation except that the paper was changed to 190 cm, and the same tests as in Example 1 were carried out, and the results are shown in Table Shown in 1.

Comparative Examples 1 to 10 A basis weight of 45 g/m' was obtained using the same method and operation as in Example 1 except that PAMPA-1 and UP-1 were not added.
Comparative Example 1 paper was obtained and the PA added in Example 1
The basis weight was 45 i/r using the same method and operation as in Example 1 except for changing the amounts of MPA-1 and UP-1.
r? Comparative Examples 2 to 10 papers were obtained. The same tests as for the Example 1 paper were also conducted on the papers of these comparative examples, and the results are shown in Table 1.

Examples 6 to 8 In Example 1, the amount of PAMPA-1 added and UF-1
Examples 6 to 8 with a basis weight of 45 ji/m were prepared using the same method and operation as in Example 1 except for changing the combination of the amounts added.
Obtain papers, measure the physical properties of these papers, and show the results in Table 2.
It was shown to.

Comparative Examples 11 to 20 In order to clarify the usefulness of the combinations of the amounts of PAMPA resin and urea formaldehyde polymer particle aggregate added to the blended pulp according to the claims of the present invention in Examples 6 to 8,
Comparative Examples 11 to 20 papers with a basis weight of a5trljj/m were obtained using the same method and operation as in Example 1 except that the combination of added amounts of PAMPA-1 and UP-1 was different, and the physical properties were similarly evaluated. The results are shown in Table 2.

〔effect〕

From Table 1, even if the amount of PAMPA resin added is within the range of the present invention, if the amount of urea formaldehyde polymer particle aggregate added is less than or exceeds the range of the present invention, the wet pick will be low, and the amount of urea formaldehyde polymer particle aggregate will be low. Even if the amount of polymer particle aggregate added is within the range of the present invention, PAM
If the PA resin is less than the range of the present invention, wet pick performance is low, and the range of the present invention provides excellent physical properties in terms of wet pick performance, whiteness, white paper opacity, post-print opacity, ink receptivity, and horizontal paper recovery. It is clear that it is possible to produce printing paper having

Also, it is clear from Table 2 that even if the urea formaldehyde polymer particle aggregate is present in the 4th circle, if the amount of PAMPA resin added is less than the range of the present invention, the wet pick will be low as shown in Table 1. If it exceeds the limit, it will be very difficult to collect the waste paper and it will take a long time to disintegrate it.
When the urea formaldehyde polymer particle aggregate falls within the range of the present invention, high wet pick performance can be obtained with a small amount of PAMPA resin added, and waste paper can be easily recovered.

From Tables 1 and 2, it is clear that the present invention is a method for producing extremely transparent printing paper, which cannot be achieved using conventional techniques.

Claims (1)

[Claims] Printing characterized by papermaking by adding 0.5 to 20% by weight of urea formaldehyde polymer particle aggregate and 0.05 to 1.2% by weight of epichlorohydrin-modified polyamide polyamine resin to pulp slurry based on dry pulp. Paper manufacturing method.