JPH0978495A - Surface sizing liquid composition for printing paper and printing paper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a surface sizing liquid composition for printing paper, comprising starch containing a prescribed amount of amylopectin and a water- resisting agent and capable of providing printed paper having strong surface strength and insoluble to the applying aqueous solution. SOLUTION: This surface sizing liquid composition comprises (A) preferably 80-99wt.% starch having an amylopection content in an amount of >=95wt.% based on total weight and (B) preferably 1-20wt.% water-resisting agent which is a cyclic amide-based resin such as a cyclic amide-aldehyde-based resin and/or a zirconium-based compound such as zirconium acetate. Furthermore, the surface sizing liquid composition is applied to the surface to provide the objective printed paper.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface size liquid composition applied to the surface of printing paper for publications, advertisements, newspapers and the like.

[0002]

2. Description of the Related Art In recent years, printing of printing paper has good ink receptivity, little strikethrough, easy plate making, and a replication speed.
Lithographic offset printing has become the mainstream because it is fast, can produce plates of any size, is easy to reprint, does not expand or contract during printing, and is suitable for multicolor printing.

As mentioned above, the lithographic offset printing has many excellent points, but it also has drawbacks such as the fact that a dampening water solution must be used at the time of printing and the tack of the ink used is high. From these points, in the case of lithographic offset printing, it is necessary to make the dry and wet surface strengths sufficiently strong so that the pulp fibers and the filler on the surface of the printing paper are not removed by the tack of the ink. If the surface strength is weak, pulp fibers and fillers will adhere to the blanket or printing plate of the printing machine, which will cause printing problems such as poor ink deposition. As a measure against the above trouble, it has been practiced to apply starch, polyvinyl alcohol, polyacrylamide or the like to the surface of the printing paper as a surface size liquid to increase the dry and wet surface strength. Although this achieved the initial purpose to some extent, since the above-mentioned substances were water-soluble, they were gradually dampened during printing and dissolved in the aqueous solution, which increased the stickiness of the blanket and caused the blanket to wrap around the printing paper. It may result in deterioration of the cleaning property of foreign matter on the blanket or printing plate, and may cause coagulated foreign matter in the ink. Therefore, there has been a long-awaited development of a surface-size liquid that is water-soluble at the time of application, but becomes water-insoluble after application, and further increases the surface strength.

As a conventional technique relating to the above problems, there is disclosed a surface sizing composition comprising a cationic starch and an ASA-treated starch which is a monoester of alkenyl succinate blended, as disclosed in Japanese Patent Application Laid-Open No. 2-74697, vinyl simple substance. JP-A-5-287695, which is a surface treatment agent containing a cationic emulsion obtained by adding a cationic polymer to a copolymer of a monomer and an unsaturated carboxylic acid, a surface treatment using a substituted succinic acid (derivative) as an active ingredient JP-A-6-19299
5. Japanese Patent Application Laid-Open No. 5-195489, which is a starch composition for paper coating in which high-viscosity starch and low-viscosity starch are blended, has been proposed. However, these are aimed at improving water resistance, reducing porosity, improving surface strength, and preventing sticking during rewetting, and it is not possible to satisfy both prevention of elution into a dampening aqueous solution and improvement of surface strength. Absent. For the purpose of preventing elution into a dampening aqueous solution and improving the surface strength, JP-A-5-195 is known.
No. 489, which is a starch composition for paper coating in which a high-viscosity starch and a low-viscosity starch are blended, but this is still not sufficient.

[0005]

DISCLOSURE OF THE INVENTION The present invention is intended to provide a surface sizing liquid composition for printing paper which does not elute in a dampening aqueous solution and improves surface strength.

[0006]

The present invention adopts the following constitution in order to solve the above problems. That is, the first invention of the present invention is that "the content of amylopectin is 95% of the total weight.
A surface-size liquid composition for printing paper, which comprises a starch and a water-proofing agent in an amount of at least wt. A second invention of the present invention is "a surface-size liquid composition for printing paper according to the first invention, wherein the waterproofing agent is a cyclic amide resin and / or a zirconium compound". . Further, the third invention of the present invention is "a printing paper obtained by applying the surface size liquid composition of the first or second invention on the surface".

[0007] It is not clear why the surface-size liquid composition of the starch and the water-proofing agent, in which 95% by weight or more is amylopectin, does not elute surprisingly in the aqueous solution, but it is presumed as follows. Starch is generally composed of a straight-chain molecule amyrose and a branched molecule amylopectin. Further, in order to make the water-soluble polymer substance insoluble in water, it is necessary to form a network structure. Here, since amylopectin is a branched molecule, it is considered that a dense network structure is formed by slightly cross-linking it with a waterproofing agent. On the other hand, Amilo
It is considered that since the sponge is a linear molecule, only a low-density network structure is formed even if it is crosslinked with a waterproofing agent. Therefore, it is considered that the higher the proportion of amylopectin in the starch, the higher the insolubility in the case of the crosslinking reaction with the waterproofing agent.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The starch used in the present invention is not particularly limited as long as 95% by weight or more of the total weight is amylopectin, and for example, waxy corn starch in which 99% by weight or more is amylopectin, or amylopectin and amyloses. Separated 95% by weight
There are starches and the like from which amyloses have been removed so as to become amylopectin. There are no particular restrictions on the starch raw material used in this fractional removal method, and examples thereof include cone, potato, tapioca, rice, wheat, sweet potato, and the like, and two or more of these may be used in combination. When using waxy corn starch, other starch may be mixed as long as the amylopectin content is 95% by weight or more. Further, the starch used in the present invention may or may not be modified, and examples of the modified treatment include cationization, phosphorylation, hydroxyethylation, oxidation, enzyme treatment and the like. .

The water resistance agent is not particularly limited, and zirconium compounds, melamine-formaldehyde resins, urea-
Formaldehyde resin, polyamide polyurea-formaldehyde resin, glyoxal, dialdehyde starch, cyclic amide resin, glycerin diglycidyl ether, polyamide-epoxy resin, diphenylmethane-
There are bis-4,4′-N, N ′ diethylene urea and the like, and among them, cyclic amide-aldehyde resin and zirconium compound (zirconium acetate, zirconium carbonate, zirconium chloride, etc.) are preferable.

If desired, a synthetic surface sizing agent may be used. Polystyrene-maleic acid resin, polystyrene-maleic acid half ester resin, poly α-olefin-maleic acid resin, poly α- Olefin-maleic acid half-ester resin, polystyrene-acrylic resin, polystyrene- (meth) acrylic acid ester- (meth) acrylic acid resin, rosin ester, modified alkyd resin, polyamide resin, alkyl ketene dimer, etc. is there.

The mixing ratio of the starch and the waterproofing agent is also not particularly limited, but in consideration of the dissolution property into the dampening aqueous solution, the surface strength, and the balance of the effective reaction between the starch and the waterproofing agent, the solid content weight is Assuming that the total composition is 100% by weight, 80% starch
˜99% by weight and 1-20% by weight of the waterproofing agent are suitable. Further, when the synthetic surface sizing agent is used in combination, it is preferable to add it at a compounding ratio which does not exceed 100% of the addition ratio of the waterproofing agent.

In addition, if necessary, a dry paper strength enhancer, a drainage improver, a retention improver, a slime control agent, a pitch control agent, a defoaming agent, a wet paper strength enhancer,
You may use dye etc.

A coater for applying the surface size liquid of the present invention.
Also, there is no particular limitation, and a roll press such as a size press, a gate roll coater, a metering size press, an air knife coater, a blade coater, a rod coater, There are a metalling bar coater, a gravure coater, and the like. The coating amount is 0.1 g / total solid weight of both sides.
In the range of m ^{2 to 3} g / m ² , preferably 0.2 to ² g / m
²

In the present invention, the printing paper includes not only publications and advertisements, but also newspapers and information sheets used for printing. The pulp used for producing the printing paper of the present invention is not particularly limited, and mechanical pulp such as GP, RGP, CGP and TMP, chemical pulp such as NBKP and LBKP, waste paper pulp and the like can be used. Furthermore, in papermaking, acidic papermaking,
It can be applied to both neutral papermaking.

[0015]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples. Moreover, all percentages are by weight.

<Measurement of amylopectin content in starch> It was measured according to the iodine colorimetric colorimetric method (P.174-175, Starch Science Handbook, published by Asakura Shoten).

<Measurement of Starch Elution Rate> Five 5 cm × 20 cm samples were folded into bellows and rotary shaker.
It is put in a polybin for use, and 100 ml of ion-exchanged water is added thereto and immersed. This is stirred at 150 rpm for 3 minutes using a rotary shaker. Remove the sample after stirring. The remaining elution solution is taken with a 25 ml hole pipette and put in a 100 ml volumetric flask. Further, 5 ml of a 1: 1 HCl solution and 2 ml of a 0.1N KI-I ₂ solution were added to make 100 ml with ion-exchanged water. At this time, a control solution is prepared in which the same chemicals are added and operated, except that the elution solution is not added. After color development by addition of chemicals, the mixture is left for 10 minutes, and the absorbance at 580 nm is measured with a UV absorptiometer. The absorbance of the control solution is set to 0 point. The amount of starch (A) in the elution solution is determined from the measured absorbance and the calibration curve prepared in advance. With the total amount of starch (B) applied to the sample, the dissolution rate of starch is calculated from the following formula. Dissolution rate = (A / B) x 100

<Surface Strength> A (dry) paper sample is set in an RI printability tester, and P
0.5 ml of printing ink TAK GRADE 18 (TOYO INK) is supplied to the rubber roller of the RI printability tester, kneaded for 2 minutes, and printed at a printing speed of 60 rpm. After printing, the paper sample is visually evaluated for the trabecular condition of pulp fiber and filler. (Wet) The same operation as in dry is performed except that water is supplied to a paper sample with a rubber roll moistened with tap water immediately before printing, and the fiber trajectories are visually evaluated. The evaluation criteria are the same for both dry and wet. ⊚: Pulp fibers and / or filler are not traversed at all. ◯: Pulp fiber and / or filler is slightly slipped. Δ: Pulp fiber and filler are considerably loose. ×: Pulp fiber and filler are traversed on the entire surface of the sample.

<Example 1> CATO 240 (amylopectin content: 99.5%, cationized waxy-corn starch, National Starch and Chemical) in solid content of 95%, SECUREX R (cyclic amide type) A resin, tricrystal) is prepared to a surface size liquid composition having a solid content of 5%. This composition was applied to a medium-weight paper having a weight of 46 g / m ^{2 on a} basis weight of both sides by a gate roll coater so that the coating amount was 0.5 g / m ² on both sides.
The sample was dried at 1 ° C. for 1 minute to obtain a surface-sized sample. This sample is pretreated in accordance with JIS P8111, and the amount of starch eluted in the surface size solution and the surface strength are measured. The results are shown in Table 2.

<Examples 2 to 5> Samples were obtained in the same manner as in Example 1 except that the surface sizing composition and the coating amount were as shown in Table 1, and the starch elution amount and surface strength were determined. It was measured. The results are shown in Table 2.

<Comparative Examples 1 to 5> Samples were obtained in the same manner as in Example 1 except that the surface sizing composition and the coating amount were as shown in Table 1, and the starch elution amount and surface strength were determined. It was measured. The results are shown in Table 2.

Comparative Example 6 Starch (concentration 8% by weight, 45% by weight) of corn starch lightly oxidized with sodium hypochlorite
A 1: 1 mixture of highly-oxidized starch (concentration: 15 wt%, 45 ° C., B-type viscosity: 100 cp) and gelatinized a 1: 1 mixture to prepare a surface-size liquid with a solid content of 5% by weight. did. Using this surface size solution, a sample was obtained in the same manner as in Example 1, and the amount of starch eluted and the surface strength were measured. The results are shown in Table 2. Comparative Example 7 The same measurement as in Example 1 was performed on the paper obtained in the same manner as in Example 1 except that the surface sizing agent was not applied, and the results are shown in Table 2.

[0023]

[Table 1]

<Notes to Table 1> -CATO SIZE 240: Amylopectin content = 99.5%, cationized waxy corn starch (National Starch Chemical) -CATO SIZE 270: Amylopectin content = 99.2%, cation Wax-cone starch (National Starch Chemical) ・ FILM K0TE 54: Amylopectin content = 99.7%, esterified wax-cone starch (National Starch Chemical) ・ MS-3800: Amylopectin Rate = 70.8%, oxidized corn starch (Nippon Shokuhin Kako) -Penford Gum 280: amylopectin content = 72.3%, human ethoxyethyl ether
Tellurized corn starch (Nissei Mutual Benefits) -Nilgame A-85: Amylopectin content = 80.1%, Urea phosphate esterified potato starch (Matsuya Chemical Industry Co., Ltd.)-Secuex R: Cyclic amide resin (Sansei) ) -Violet 636: Polyamide resin (Sumitomo Chemical) -Bacote 20: Zirconium carbonate salt (Nippon Light Metals) -Gicosol ZA-20: Zirconium acetate salt (Daiichi Rare Element Chemical Industry) -SANCISA-HS-5 : Styrene-acrylic resin (Sanyo Chemical Co., Ltd.) ・ Comparative Example-7: Medium-quality base paper (uncoated)

[0025]

[Table 2]

[0026]

As shown in Table 2, a surface-size liquid composition comprising starch and a waterproofing agent having an amylopectin content of 95% by weight or more based on the total weight has stronger surface strength and can be used in a dampening aqueous solution. On the other hand, insoluble substances became possible.

Claims (3)

[Claims] 1. The content of amylopectin is 95 based on the total weight.
A surface-size liquid composition for printing paper, which comprises starch and water-proofing agent in an amount of at least wt.%. 2. The waterproofing agent is a cyclic amide-based resin and / or a zirconium-based compound.
Surface-size liquid composition for printing paper. 3. A printing paper obtained by applying the surface-size liquid composition according to claim 1 or 2 onto a surface.