JPH04240296A - Easy dispersion 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]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to writing and printing paper which can be easily dissociated and dispersed into individual fibers in water.

0002

[Prior Art] Conventional printing paper generally has internal sizing agents, external sizing agents, paper strength enhancers, etc. added to give it water resistance, writability, and printability, making it difficult to disperse in water. It is not easily dissociated and dispersed into individual fibers.

[0003] Conventionally, a method of adding carboxymethyl cellulose salt and an alkali metal compound to pulp slurry was used to improve the water dispersibility described above (Japanese Patent Publication No. 43-28766).
No., Japanese Unexamined Patent Publication No. 02-149237), etc. are known.

0004

SUMMARY OF THE INVENTION The present invention improves the dispersibility of paper in water and provides an easily dispersible writing or printing paper that is easier to produce.

[0005]

[Means for Solving the Problems] As a result of extensive research, the present inventors added polyethylene oxide to the raw material pulp slurry in an amount of 0.2 to 0.5% by weight based on the pulp, thereby substantially eliminating the sizing agent and paper. It has been found that by making paper without adding a force enhancer, it can be easily dissociated and dispersed into individual fibers in water.

[0006] There are no particular restrictions on the type and composition of the raw material pulp used in the present invention. If the paper has a small basis weight and lacks strength, softwood pulp may be added as appropriate. In that case, softwood kraft pulp (NBKP) 15-7
0% by weight and hardwood kraft pulp (LBKP) 85-3
It is preferable to mix 0% by weight.

The amount of polyethylene oxide added is 0.2 to 0.5% by weight, preferably 0.3 to 0.0% by weight based on the pulp.
．． It is 4% by weight. Even if the amount of polyethylene oxide added is 0.5% by weight or more, the dispersibility of the paper does not improve much, and on the contrary, the blanket of the papermaking equipment becomes dirty and becomes an obstacle in the papermaking process.

[0008] The pulp can be used either unbeaten or beaten, but the freeness is 300 to 600 ml, preferably 400 to 500 ml. If the pulp freeness is less than 300 ml, the water dispersibility of the paper produced will be insufficient, and if it is more than 600 ml, the dry paper strength and prevention of pinholes on the paper surface will be insufficient.

[0009] By adjusting the pulp freeness to 300 to 600 ml, printing paper with excellent dry paper strength, no pinholes on the paper surface, and excellent water dispersibility has become possible.

[0010] It is preferable that neither a sizing agent nor a paper strength enhancer is substantially added.

The raw material pulp slurry thus prepared is supplied to a paper making process. Each part of the papermaking process (wire, press, dryer, calendar, winder) may be of any type and is not particularly limited. In the calender part, calender finishing processing may be performed according to product target specifications.

0012

Effects of the Invention As described above, the present invention provides a writing paper that can be produced by ordinary papermaking methods, easily dissociates and disperses into individual fibers in water, and has excellent dry paper strength and pinhole prevention. It has also become possible to provide paper that can be used for printing.

[0013]

[Examples] The present invention will be explained below with reference to Examples, but the present invention is not limited to these Examples.

Example 1 A blended pulp consisting of 50% by weight of softwood kraft pulp (NBKP) and 50% by weight of hardwood kraft pulp (LBKP) was beaten to a freeness of 450ml, and the slurry was mixed with polyethylene oxide (manufactured by Tetsu Seikagaku Co., Ltd., PE).
O) was added in an amount of 0.3% by weight based on the pulp, and a paper having a basis weight of 37 g/m2 was made using a Fourdrinier paper machine and dried with a Yankee dryer.

As for the physical properties of the obtained paper, tensile strength and water dispersibility were evaluated by the following methods. 1. Tensile strength Measured according to the JISP8113 test method. 2. Dispersibility in water Pour 500ml of water into a 1000ml graduated cylinder, immerse one 10cm x 10cm piece of test paper in the water, then press the top of the graduated cylinder with your hand and turn it upside down.
The state of dispersibility in water after shaking was evaluated. In the evaluation of dispersibility, commercially available toilet paper was used as a standard for paper with good dispersibility. The evaluation criteria at this time are as follows. ○: Good dispersibility △: Slightly poor dispersibility ×: Poor dispersibility

Comparative Examples 1 and 2 In Example 1, the blended pulp freeness was 230 ml and 700 ml.
Paper was made in the same manner as in Example 1, except that each sample was prepared in ml, and the tensile strength and dispersibility in water were evaluated.

Comparative Example 3 Paper was made in the same manner as in Example 1 except that polyethylene oxide was not added, and the tensile strength and dispersibility in water were evaluated. Table 1 shows the results of Example 1 and Comparative Examples 1 to 3.
Shown below.

[0018]

[Table 1]

Claims (1)

[Claims] [Claim 1] An easy-to-make paper characterized in that 0.2 to 0.5% by weight of polyethylene oxide is added to the raw material pulp slurry based on the pulp, and paper is made without substantially adding a sizing agent or a paper strength enhancer. Dispersible printing paper.