JPS5869099A - Manufacture of paper supporting body for lithographic plate - Google Patents

Abstract

PURPOSE:To obtain a supporting body which can provide a product inexpensive and free from curl with a higher printing durability preventing elongation during the printing by adding a cationic synthetic resin emulsion to a wood pulp slurry to make a paper. CONSTITUTION:A cationic synthetic resin emulsion (preferably, a stylene-butadiene copolymer or an ester acrylate based copolymer emulsion) is added to a wood pulp slurry preferably in the amount of 20-100 part in the form of solid with respect to 100pts.wt. of the pulp and at the same time, an inorganic pigment sich as aluminum sulfate, clay, calcium carbonate, titanium oxide and an assistant such as polyamide epichlorohydrine resin are done so as required. The mixture is made a paper to obtain the intended supporting body. EFFECT:This product is so excellent in the water resistance that it can be reduced to less than 0.3% in the elongation when contacting a damping water during the printing while protected from damage thereby providing a printing durability equivalent to 10,000-20,000 sheets.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a base paper used as a support for a lithographic printing original plate.

Conventionally, lithographic printing original paper supports have generally been produced by adding water-resistance reinforcing agents such as mela-formaldehyde resins to wood pulp slurry and making paper, but the base paper obtained in this way still has insufficient water-resistance strength. When used as a lithographic printing original plate, the dampening water supplied during printing will cause the original plate to stretch or be damaged by more than 2% as the number of printing sheets increases, especially when performing high-speed long-time printing mt+, resulting in printing misalignment. As a result, the printing area may increase, or printing may become impossible, resulting in a stiffness resistance of about 3,000 to 5,000 sheets at most. When the amount of melamine to formaldehyde resin added to the pulp exceeds 0.5%, there is a drawback that formalin odor is generated during heat fixing of an image when used as a dry electrophotographic lithographic printing original plate.

As the second method, 1% Kaisho 52-78B02, 1+y
As disclosed in No. J 53-29802, there is a method in which wood noruzosu 2-li and polyoleain-based synthetic norupus slurry are mixed, paper-formed, and then heat-treated, but this method does not require the use of expensive synthetic pulp. The third method is to make a wood slurry and coat the surface of the resulting base paper with 4-lithelene, but this method is uneconomical due to changes in humidity and dampening water from the false cross section. It has the disadvantage of curling due to penetration.

The purpose of the present invention is to provide a method for producing a lithographic printing original paper support that prevents elongation during printing when used as a lithographic printing original plate, improves printing durability, and provides an inexpensive product that does not cause curling. That is, the method of the present invention is characterized in that a cationic synthetic resin emulsion is added to a wood pulp slurry to form paper.

The synthetic resin emulsion used in the present invention may be any cationic one, such as polyvinyl acetate, polyvinyl chloride, I-lyacrylate, styrene-butadiene copolymer, styrene-lyacrylate, etc. Examples include emulsions such as polymers, ethylene-vinyl acetate copolymers, and ethylene acrylic ester copolymers, among which styrene-butadiene copolymer emulsions and acrylic ester copolymer emulsions are preferred.

These cationic synthetic resins are water resistant and have good fixing power to pulp, so they can firmly coat the surface of pulp and make paper supports with excellent water resistance and interlayer adhesion. The amount of thionic synthetic resin emulsion used is usually 5 to 150 in terms of solid content based on the pulp Zoo weight part.
Parts by weight, preferably 20 parts and 1001 parts by weight. As the wood pulp slurry, those conventionally used can be used as they are. The papermaking conditions may also be exactly the same as conventional ones.

In the present invention, in order to further improve the fixing properties of the cationic synthetic resin, inorganic pigments such as sulfuric acid, clay, calcium carbonate, titanium oxide, polyamide epichlorohydrin resin, and other auxiliaries can be used in combination.

The paper support of the present invention obtained as described above has particularly excellent water resistance, so when used as a lithographic printing original plate, the elongation is 0.3% or less even when it comes in contact with dampening water during printing. 10,000 to 20 because it can be suppressed and does not cause damage.
It can exhibit printing durability of about 000 sheets.

The present invention will be explained below by way of examples. All parts are by weight.

Dormitory IN Example 1 NUKP (Unexposed 2 Futononorupu) 50
Part LBKP (Hardwood Saving Craft No.1) 5
0 parts cationic polyacrylic acid ester emulsion (solid content 40%) [Showa Kobunshi Co., Ltd. Y table Polysol AM 50
Part 2386)
(as solid content) Slurry (beating!fVi400cF')
The adhesion amount after drying s) on a fourdrinier paper machine is 131 f/m.
A paper support was prepared by making the paper so that it had the following properties.

Next, an 8% aqueous solution of polyvinyl alcohol is applied to the surface of this support to form a precoat layer with a coating weight of 3 f/m', and then a liquid with the following formulation is applied to the opposite side and dried to obtain a coating weight of 1Of. A conductive paper support for an electrophotographic X-type lithographic printing original plate was obtained by providing a coating layer of /mJ and super calendering with a nip pressure of 50 kg.

200 parts of 50% aqueous dispersion of clay? Reseal M-17) (as a shadow) 10% aqueous solution of polyvinyl alcohol 120
Part C670) 5
0 parts water 2
00 parts Next, the following intermediate layer g is applied to the back coated side of this support.
After coating and drying, an intermediate layer with a coating amount of 0.7 f/m' was provided.The following photoconductive layer solution was coated, dried, and attached.
A photoconductive layer of 3 t/m1 was provided to obtain an electrophotographic lithographic printing original plate.

Intermediate layer liquid Thermo 2 Tsuk U-230m] 100 parts Conate L''1 15 g toluene 660 parts Photoconductive layer liquid zinc oxide [Zex 2000 manufactured by Sakai Chemical Co., Ltd.] 100 parts 7/IJ resin 50 % toluene solution [Hon Nippon Ink (A-401 manufactured by l) 20
50% toluene solution of acrylic resin [Ll-800 manufactured by Mitsubishi Rayon (Ten)]
20 parts Rose Bengal 0.1 part Toluene 100 parts The lithographic stamp 461JM plate thus obtained was made using a commercially available electronic plate making machine, fixed, and then printed using a commercially available offset printing machine.
20,000 clear prints were obtained. The elongation of the original printing plate at this time was 0.5%.

LOL Example 2 NUKP 50 copies LBKP
fiO part cationic styrene ~ acrylic acid varnish part 40 axis)
A dry weight of 129 f/'g was produced using a fourdrinier paper machine using Pargis 2 Li, which consists of two parts of sulfuric acid band.
A paper support was created by making paper so that the following formula was applied to the surface of this support (solid content: 30 millimeters).
was applied and dried at 130℃ for 3 minutes to achieve a coating weight of 2097g1.
A direct seeding planographic printing original plate was prepared by forming a hydrophilic layer.

Titanium oxide 100 parts Polyvinyl alcohol 20 parts Carbon formaldehyde resin 4 parts Ammonium chloride
2 parts Zinc chloride 1 part Next, an aqueous solution of 0.1% sodium alginate was applied to the surface of this original plate and dried to obtain a direct seeding type offset master. When this was plate-made using a commercially available electrophotographic copying machine and offset printed as an offset master, no peeling, wrinkles, or other defects occurred even after printing 10,000 sheets. O was extremely low at 3%.

Claims (1)

[Claims] 1. A method for producing a lithographic printing original paper support, which comprises adding a cationic synthetic resin emulsion to a wood Alupus slurry and forming the paper.