JPS5898499A - Production of printing high grade 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] The present invention uses dry waste paper for unbeaten or lightly beaten paper stock. This invention relates to a method for producing high-grade paper for printing with low density, which is characterized by mixing a small amount of extremely beaten material and making paper.

There are various qualities required for high-quality paper for printing, but with the trend toward lighter paper and faster printing machines, it is necessary to have thickness (low density), high smoothness, and the ability to print in one liter. Recently, paper with high strength and good dimensional stability has become increasingly desired. Paper is manufactured by variously devising raw material formulations and paper-making conditions to meet these requirements, but many of the required qualities have contradictory properties. There were limits to achieving both. For example, paper that is thick and has good dimensional stability can be obtained by reducing the degree of beating of the raw material pulp, but in this case, it is not only difficult to achieve a level of smoothness over a certain level, but also difficult to print. The strength becomes weak and cannot withstand high-speed printing. Moreover, the strength of the wet paper is also reduced, which significantly reduces the paper-making efficiency, and furthermore, problems arise such as the accumulation of fiber axes on the press roll, making paper-making practically impossible.

The inventors of the present invention have conducted various studies to overcome the disadvantages of the conventional 2nd grade paper and to reduce the density of paper. Lightly beaten paper stock 70～
95% by weight of dry horizontal paper or recycled waste paper with a beatingness of 1
It was discovered that the object could be achieved by beating the paper in extremely cold temperatures to less than 00+1 LzcsFff, and mixing 5 to 60% by weight of tomomo into paper-making, leading to the completion of the present invention.

The paper stock with which the extremely beaten material is mixed refers to pulp of L material, M material, or mixed pulp 2 such as pulp, and bleached chemical pulp is particularly desirable for the purpose of high-grade paper for printing.

It should be noted that if the beating degree is advanced beyond *450 xt csy, there will be no difference from mere beating which is the prior art, and the advantages of the present invention will be lost. Dry horizontal paper refers to the dry end of paper machines and the finishing process of wine goo, cutter, etc., and the disintegrated material of 7 usually has a beating degree of 500.
~400 ns, indicating tC8F. Collected waste paper once goes on the market, is used by users, and is later collected, deinked,
It refers to waste paper pulp that has gone through various processes such as bleaching and selection, and from the purpose of the present invention, it is intended to be high-grade paper for printing. It is preferable to use the so-called old white paper. Dry horizontal paper or recycled waste paper can be beaten by any type including disk type 7 aina, and the beating concentration can be from 1 to 65% by weight.
A commonly used concentration range can be used.

The more the beating is advanced and the mixing amount is reduced, the greater the desired density reduction effect is, so the degree of beating is 100 pn, t C8
F or less, and the mixing ratio is 5 to 60% by weight as mentioned above, and in the case of dry waste paper, the remainder is preferably used by performing only the disintegrating treatment as usual. Mixing ratio of extremely beaten material is 5% by weight
If it is less than that, the effect as a binder will be low, leading to a decrease in the strength of the paper. Moreover, if the mixing ratio exceeds 50% by weight, the number of adhesion points between fibers will increase, and the characteristic of the paper layer structure with many voids will be lost.

The final beating degree (measured after mixing) of the raw material to be mixed, the method of using fillers and various internal additive chemicals, etc. may be the same as when using normal raw materials, but may of course be changed as necessary.

If the final freeness is kept the same, the paper making conditions are also large fibers. There is no difference, especially in press rolls which are a problem in paper making.

It is recognized that the lees loading condition is the same, but it is necessary to adjust it slightly because the freeness in normal cases such as water draining on the wire, water squeezing ability of the press roll, and draw of wet paper changes slightly in the direction of the paper. is.

Comparing the paper obtained by applying chemicals and adjusting the calendering conditions as is normally done in a size press with the paper produced by the prior art, it was found that the final freeness of the raw material, the paper weight,
When the smoothness is kept the same, there is clearly a difference in the paper layer structure, and the former is bulkier and thicker because it has more void areas. Additionally, printability such as paper opacity, stiffness, and one-dimensional stability is improved. On the other hand, it is undeniable that the paper strength such as specific bursting strength will decrease, but the decrease in printing strength on an actual printing machine is small, probably due to the presence of slightly more size breath chemicals and more uniform adhesion. It is not a problem in terms of use.

To further improve the printing strength, size reinforcing agents, dyes, etc. can be added in addition to the table and usual size press coating chemicals by known methods. Since the paper made according to the present invention has a pore structure, the surface sizing liquid has good permeability into the paper, and the amount of coating liquid is slightly increased compared to ordinary paper.

Hereinafter, a more detailed explanation will be given with reference to Examples. In the examples, all references to "weight" refer to the weight, and in the case of dry horizontal paper collected once, the weight includes the filler contained therein. Moreover, the numerical values in the examples are values measured and calculated by the following method.

The water level at 1F was in accordance with J Engineering SP 8121 (Canadian standard p water level tester), but if it contains fillers etc., they should be combined as 3y.

Paper thickness and density) are J-K SP 8118, smoothness is J-K SP 8119, and opacity is J-K SF 813.
8 B method, stiffness is J engineering s p 8125 # air permeability is J
Engineering SP 8117, bursting strength #'1JxSp 81
12. Dimensional stability is the elongation of paper under water (J).

TAPP I 279) was used as a scale.

The surface strength was measured using a Roland printing machine under certain conditions (20°C
,65% RE, ,X heat 5000 sheets/h
r) Black and white printing was performed, and the degree of peeling of the 200th sheet of paper was evaluated as 0.1 rrL2wsoco white spot Q side number and expressed as printing strength.

Example 1 L, BKP (freeness degree 405 9tc day F) 100
%, 0.3% sizing agent and 2.0% band sulfate (both relative to pulp) were added to make paper, and a starch solution (1! degree 51%) was applied using a size press to obtain a weight of 64 F// Lt (
7) Used as paper Radry waste paper. The dry horizontal paper was disintegrated, passed through a single disc refiner at a pulp density of 4.5 cs, and extremely beaten to obtain a beating degree of 80yzzcsy.几L, mixed with BKP paper stock 9. The final freeness is 4401FLtC8? , ! 180
vn,t CB'l det yt.

This mixed stock contains 0.5% sizing agent and 2.0% sulfuric acid.
(both are for pulp) and tested by test machine to 16 tsubo
0y//L, z paper is made. Surface sizing was performed by applying a 5.0% solution of oxidized starch (trade name: Nissan Sizer 700, manufactured by Ajinomoto Co., Ltd.) using the size press of a test machine, and the paper had a smoothness of approximately 250θC with a constant calender linear pressure of 15 Ky/cfn. I got it.

Regarding the paper stock made by the conventional method, L and BKP are each 44
After beating to 0 m-1 and 580 m-t C8F to match the degree of beating, papermaking was performed in exactly the same manner as described above, and the paper quality was compared.

The results obtained are shown in Table 1.

As is clear from the margin Table 1 below, the extremely beaten horizontal paper of the present invention 1
The paper made by mixing 0- or 20% of paper is beaten individually to the same degree of beating, and the thickness increases and the density decreases at the same basis weight and smoothness compared to paper made by the conventional method. are doing. Nine submerged water extensions.

Opacity and rigidity are also improving. Although the specific bursting strength is slightly lower, there is no difference in printing strength between the conventional method and the method of the present invention in the original printing test conducted under conditions close to the actual machine.

Example 2 The dry horizontal paper of Example 1 was extremely beaten to obtain a beating degree of 3Q m
, l C8F and the following so that the mixing ratio is 25%: Beating degree 520 nLt C8F glue, BKP85sIN;
, mixed with BKP 15% stock. Final freeness level 60
yrbt C8F and Natsuri. A filler (Merck) is added to this mixed stock so that the filler content in the paper becomes 5% or 15%, and further 0.5% sizing agent and 2.0% sulfuric acid
(all for pulp) and paper with a basis weight of 70 y/- was made using a test machine. Oxidized starch (product name: Varnish Sansizer 7) was manufactured using the size press of the test machine.
00. (manufactured by Ajinomoto Co., Ltd.) 5.0%, auxiliary sizing agent (product name: Size Up 411 K, manufactured by Arayo Kagaku Kogyo Co., Ltd.) L
], a 15% concentration liquid was surface sized, and the smoothness was set to about 4L1gθC using a calendar line E1GKg-.

L-BKP 85%N, BKP 15% paper stock 350
It is beaten to tC13F, and the paper filler target is also 5%.
Alternatively, filler (talc) is added to give a total density of 15 cm, followed by a sizing agent and sulfuric acid band, followed by surface sizing to prepare a comparison sample.

The paper quality of these papers was measured and the results are shown in Table 2.

Table 2 It is clear from the results in Table 2 that paper made by the method of the invention maintains its superiority in thickness and density compared to the conventional method even if filler is added. Further, if the thickness density is kept constant, it is also possible to incorporate filler in an amount more than twice the amount in the method of the present invention. Other paper qualities with an opacity level of 7 are also comparable to conventional methods.

Example 6 Used continuous slips printed on a computer were collected and deinked and bleached using the following process. Put the waste paper in a steamer that can heat and stir it, add 4% caustic soda,
Added 1.5% ia acid powder (both from waste paper) and treated at 90°C at a pulp concentration of 6%. After dehydrating, washing, diluting and screening, and further adjusting the concentration, the pulp concentration was 5%.
One stage bleaching was carried out using sodium hypochlorite at a temperature of 45° C. and an amount of available chlorine of 4% (based on waste paper). Through these treatments, waste paper pulp with a yield of 85% and a whiteness of 78% was obtained.

Waste paper pulp was extremely refined using a single disc refiner at a pulp concentration of 4% to obtain 9 beaten products of CBIP with a beating degree of 165 t and 65 t, respectively.

Unbeaten (520yn-1C
8F)'s L-B is mixed with P. This gives a final freeness of 570 m, l CBII. 0.5% of sizing agent and 5% of sulfuric acid (all based on pulp) were added to this mixed stock as usual, and the basis weight was 70P//r using a test machine.
Original paper made from Lz paper. In this case as well, oxidized starch (M83800, manufactured by Nihon Shokuhin Kogyo Co., Ltd.) was added using a size press.5.
Apply 0% liquid and set the smoothness to about 6Q se'c with a constant calendar pressure of 25KF/.

On the other hand, as comparative samples, L and B KP were used at 570 WLt.
After beating to CSY, adding the same amount of sizing agent and sulfuric acid band, surface sizing with the same concentration of oxidized starch, and making paper with the same basis weight.

The results of these paper quality measurements are shown in Table 5.

As can be seen in Table 5, the thickness of high-quality paper obtained by adding extremely beaten waste paper increases and the density decreases compared to conventional single-beaten paper. Also, the water immersion elongation decreases.

It is also clear that ancillary effects such as increased opacity can be obtained.

Although the specific bursting strength and printing strength are slightly inferior, they are within a range that does not cause any practical problems. In addition, in Hono's example, unbeaten L-BKPft was used as the raw material pulp to be mixed with extremely beaten waste paper, but there were no machine troubles such as paper breakage or lees adhesion.
The same operational efficiency as the conventional method was obtained.

Claims (1)

[Scope of Claims] 1. Paper making by mixing 70 to 95% by weight of unbeaten or lightly beaten paper stock with t-5 to 60% by weight of extremely beaten material having a beating degree of 100zzcsF or less after processing paper. A manufacturing method for high-quality paper for printing. 2 Unbeaten or lightly beaten paper stock has a beating degree of 450trb1
．． cBF or higher, the method for producing high-quality paper for printing according to any one of claims 1 to 5. 5. The method for producing high-grade paper for printing according to claim 1, wherein the extremely beaten product having a beating degree of 100yzzcsy or less is obtained by subjecting the high-grade paper to dry paper waste sound generated in step 4. 4. The method for producing high-grade paper for printing according to claim 1, wherein the extremely beaten material with a beating degree of 100 m and zcsIP or less is obtained by processing recovered waste paper.