JPS58129081A - Adhesion of paper - Google Patents

Abstract

PURPOSE:An alkaline chemical is applied to one surface of paper to be bonded and a specific PVA adhesive is applied to the other, then they are bonded together to increase the viscosity of the adhesive to effect adhesion of corrugated boards and board pipes with high initial adhesion without any adverse effect on product quality. CONSTITUTION:An alkaline chemical, preferably sodium hydroxide or potassium hydroxide by 0.05-5g/m<2> on the solid basis, is applied to one of paper surfaces to be bonded, while a PVA adhesive that increases the viscosity in alkaline madium and is kept less than 7 in pH, preferably a 5-25wt% PVA aqueous solution containing PVA of 500-25,000 polymerization degree and 80-100mol% saponification degree and a reactive thickening agent such as boric acid. Then, both surfaces are bonded together by pressing to increase the viscosity of the adhesive to effect the adhesion of the paper. EFFECT:High-speed paper bonding can be effected using an inexpensive PVA adhesive through simple operations.

Description

[Detailed description of the invention] The present invention relates to a method for p# bonding one sheet of paper.

In more detail, the initial adhesion is good, and the adhesion of core base paper and finisher base paper in the production of 1-corrugated board.The adhesion of paper tube base paper in paper tube #4M.The adhesion of single corrugated board and printing paper in 1-fold paper, and the printing with Chipboard N. This article relates to the method of adhering paper, particularly in the case of adhesion to paper or the bonding of chipboard and chipboard**.

Conventionally, starch-based pastes, polyvinyl alcohol (hereinafter abbreviated as Pl)-based pastes, and the like have been widely used for bonding paper because they are inexpensive and exhibit good adhesive strength after drying. but,
These glues have a weak initial adhesion force (also referred to as slow initial adhesion), which is the ability to hold the glue together, and are suitable for applications that require fast initial adhesion, such as cardboard, paper tubes, etc. 111 such as fast laminating paper (high union paper)
I! It is not compatible with 1, so @exist, 19
In the production of balls, starch (cornstarch) is used in a special method called the Stinho method (a method in which cornstarch is made cloudy in water and then instantly gelatinized and bonded using alkal and heat). ing. but,
This bonding method is complicated because of the need for glue, and also requires large-scale equipment for heating, which requires a large amount of energy.

There are many problems such as quality problems such as "warpage" occurring in the finished product (y-). The above problems can be solved by using vinyl acetate-based emulfuran or hot melt adhesives, but these adhesives are generally expensive and require replacement if used in existing equipment. Since there are various problems that need to be resolved due to the conditions and operating speed, it is not possible to make any further changes compared to the current method. In addition, vinyl acetate-based emulsion is often used in the production of paper tubes and interleaving paper, but as mentioned above, this adhesive is expensive, and the quality is also limited by improvements in heat resistance and hard injection. There are whispers that improvements need to be made.

In light of the above situation, many proposals have been made to improve the bonding method, mainly for the production of special 1c corrugated board.

For example, unlike the Stine Hall method, a completely gelatinized starch is used as the starch-based thickening agent, and the temperature of the starch is raised in the thickening vat, and this is transferred to the paper by applying it to the paper. The viscosity increases due to the cooling of the paste when it is heated, and the viscosity increases due to the increase in the concentration of the paste brought about by the penetration of moisture into the paper waste, which thickens the paste and turns it into a gel.
A method for gluing paper is proposed. However, 7. This method is not well suited to the bonding speeds of current corrugating machines. In addition, a thickener that thickens and gels starch-based pastes and PVA-based pastes through a chemical reaction is mixed into at least one of the core base paper and liner base paper. , Naka 8111 [A method has been proposed in which a starch-based glue or a PVA-based glue is applied to the top of the corrugated paper to rapidly bond the core base paper and the liner base paper through a chemical reaction. However, the above method is not sufficiently satisfactory for application to current high-speed corrugating machines.

The present inventors have proposed a paper bonding method that uses an inexpensive adhesive agent, allows paper to be joined at high speed with relatively simple operations, and does not impair product quality. Ojo, who has conducted extensive research with the aim of can be changed.

As a result, it was discovered that the paste could be thickened and gelled to exhibit good initial adhesion, and the present invention was achieved.

In other words, the present invention has the property of applying an alkaline agent to one of the contact surfaces of one paper and increasing the viscosity with an alkaline agent to the other surface of the paper when adhering two papers, and the PH is This paper adhesion method is characterized in that by bonding both sides of the scratch 9 to which a PVA-based glue has been applied at a temperature of 7 or less, the viscosity of the fiPVA-based glue is increased and the paper is bonded.

The alkaline alkaline agent used for Kotsubakiaki is water-soluble, and the pH of a 0.5 wt% aqueous solution is 9.0 when measured at 20°C.
It refers to a substance that exhibits a value of 5 or more, and any such substance can be used in the present invention, but preferred specific examples include sodium hydroxide, potassium hydroxide,
Examples include alkali metals such as sodium carbonate, sodium silicate, barium hydroxide, and hydroxides with an alkali metallurgical Q-inclination. Among these, sodium hydroxide, potassium hydroxide, sodium carbonate, and sodium silicate are particularly preferably used.

In this paper, it is necessary that the amount of ashcaridic agent applied to paper is at least enough to thicken the PvA:$ glue, but usually 0.05~
5f/〆, particularly a range of 0.1 to S9/Ill is preferably employed.

The PVA-based glue used in the present invention refers to a PVA-based glue that has the property of increasing viscosity in the presence of alkali and has a pFI maintained below 7Lm. By incorporating reactive thickeners such as PTA and PTA, or if necessary, add bulking agents or p! It can be made by blending Ill conditioning agent, and the content of Pvum component is
7); It is preferably used as an aqueous solution, preferably 5 to 25 wtl, particularly preferably 7 to 1% wtg6.

As a PTA, the average degree of fermentation is 500 to 100, especially 500 to 25,000, and the degree of saponification is 807% or more.
100% PVA is preferably used. Also,
As for pyx, the adhesive performance is 1. <P within the range that does not damage
It is also possible to use vA partially aceterized or etherified, copolymerized with Ike's hinomer, or grafted with vA.PTA
Reactive thickener 1 refers to a substance that increases the viscosity of PTA by reacting with PVA in an alkali state. Examples of reactive thickeners include boric acid, sodium boric acid,
Alkali metal bases such as potassium mounds, ammonium enrichment of horyo, calcium base of boric acid, alkaline earth metal bases such as magnesium loading, esters such as glycerin esters of horyo, mlI steel, bottled No. 2 Examples include salts of steel such as ropes, etc. Among these, boric acid and sodium borate are particularly preferably used.

As fillers, for example, starches such as cornstarch, wheat flour starch, modified starches such as oxidized starch [Powder II
I. Charcoal + 1 It is possible to use silent enhancers such as calcium, clay, kaolin, talc, etc.

As the pH adjusting agent, it is possible to use, for example, mineral acids such as sulfuric acid, hydrochloric acid, etc., and organic acids such as oxalic acid, stearic acid, fumaric acid, etc.

If the content of the PvA component is less than 5 wt%, sufficient adhesive strength will be obtained.On the other hand, if it exceeds 25 wt%, the viscosity of the paste will become high and it will be difficult to apply it uniformly to the paper. 9 Preferably 0.5 to 15 as workability tends to deteriorate
wt*, particularly preferably 1 to 10wt96 1. S.

Bulking agents increase the solid concentration of water*i, reduce the amount of moisture carried into the paper, and smooth the bonding surface of the paper, and are effective. 1
It is preferable to mix the true equivalent amount.

The pHt4 adjuster is an additive necessary to adjust the pH of the paste to 7 or less, preferably 6 or less. When the pH of the paste exceeds 7, the paste starts to thicken, and the paste becomes so viscous that it becomes difficult to apply it to paper.

In the present invention, the amount of application of the PTA-based glue can be adjusted as appropriate depending on the requirements, and the appropriate amount of application can be determined by a simple test.

In the present invention, the method of applying the alkaline agent to the adhesive surface of paper includes, for example, a method of directly applying the alkaline agent to the paper, a method of crushing the paper in a solution obtained by dissolving the alkaline agent in water, Spray this solution on paper or
A coating method, a method of increasing the weight of an alkaline agent during paper making, dipping it in an aqueous solution of an alkaline agent, spraying this solution, or applying the solution can be adopted, and known devices can be used as appropriate.

In the present invention, methods for applying PVA thread glue to the adhesive surface of paper include, for example, applying an aqueous solution of PTA-based glue to paper with a roller, applying it with a spatula, and applying it with a slide V- or nozzle. How to cloth or PV
A method is adopted in which paper is immersed in an aqueous solution of A-type paste and then the excess aqueous paste solution is removed using a doctor grade, and various known devices are used as appropriate.

In the present invention, the method of bonding paper by laminating the contact surface of paper to which an alkaline agent has been applied and the adhesive surface of paper to which PvA-based glue has been applied is to apply pressure after overlapping both papers. A method of additional adhesion is preferably adopted. As a pressurizing method, a known method such as a method of pressurizing using a rubber belt or a cloth belt as in a corrugating machine for manufacturing paperboard or corrugated board, or a method of tightening with a belt as in the manufacturing of paper tubes, etc. is adopted. can do. Regarding the pressurization conditions, the current known pressurization conditions are sufficient.

The paper bonding method of the present invention includes not only a method of bonding separate pieces of paper, but also a method of bonding different parts of one sheet of paper, such as a method of bonding the front and back sides of one sheet of paper, or a method of bonding one sheet of paper to the other. It also includes a method of gluing different locations on the same side of paper together.

According to the method of the present invention, an inexpensive PvA-based glue is used, and a good initial
I! 11F can be obtained. In addition, since PTA-based glue is easy to remove, it can be stored and handled in the same way as the glue currently used for the surrounding parts of corrugated board manufacturing, gold paper, and paper tube manufacturing. Application of the method of the invention to the above-mentioned uses is relatively easy. Furthermore, it has many advantages, such as no special heating or the like and the ability to manufacture products without impairing product quality.

The present invention will be explained in more detail below by giving examples.

In order to measure the initial adhesive strength in one example, adhesive was applied to one side of a sheet of paper, and a 15 mm
151 x 15 pieces of 11,111 pieces of tanzak-shaped paper with a daily width
- Put several sheets (usually 4 sheets) so that it becomes 2509/d
The load was applied for 10 seconds, then the load was removed, and then the paper was peeled off at intervals of 10 seconds, and the area where the material damage of the paper was detected was i**, and according to the 9th criterion. evaluated.

Material failure 11 dark accumulation less than 596 -・× conflict
54 to less than 50 years - Δ months 5096 to less than 8046 years...○
80 or more ・-◎ An example of measuring the initial adhesive strength is shown below.

Select kraft liner (basis weight 36,097 d) as the base paper and press A/f! Sodium hydroxide is used as the oxidizing agent, and by changing the concentration of the sodium hydroxide aqueous solution, the amount of sodium hydroxide applied can be reduced to O,
[]59/d, 0.19/d, 0.2 f/m
, 0.5 f/d, 1 f/ld, and 3 f/l on the craft liner and air-dried. As a PVA-based glue, PTA (average polymerization F
1800, saponification degree of 88 mo/1/*) and a powder blended so that the ratio of boric acid and kaolin was 50: 1: 50 by weight, and the solid content was 18 wt%.
Dispersed and dissolved in water so that the following was used. This P
VA-based glue was applied to the kraft liner to a thickness of 2 mils, and an adhesion test was conducted using a tanzaku-shaped kraft liner (basis weight 56,097 d) prepared in advance, and the results were measured using the above measurement method. Table 1 shows the relationship between the amount of alkali coated on the surface of the kraft liner and the determination criteria, which was determined from the trial theory of 0 or more.

The marks X to ◎ in Table 1 and Table 9 indicate the state of peeling after 10 seconds of the above test method.

Examples 1-4. Comparative Example 1 Sodium hydroxide, sodium silicate, sodium carbonate, and potassium hydroxide were selected as alkaline chemicals, and aqueous solutions with a concentration of 59/l were prepared for each of them, and 0.0. It was applied by spraying to a coating amount (solid content) of 59% and air-dried to obtain a kraft liner coated with an alkaline chemical.

On the other hand, as a PVA-based glue, PvA
00 saponified skin (88 moy%), boric acid, and clay in a weight ratio of 50:1:50, the powder is dissolved in water to create an aqueous solution with a solid content of 18 wt*. was prepared and the pH was adjusted to 4.5 by adding V-Ulic acid. This PVA glue was applied to the gaff board using a coating rod to a thickness of 4 mils, and then the glue was applied to a rectangular single corrugated board (E tier) with a size of 15 W x 15 ■ from the lath board. transcribed.

Next, the first printing of the kraft liner and the one-dan board made as described above was measured.

For comparison, the same method as in Example 1 was used except that instead of using the liner coated with the alkaline agent, a liner to which no alkaline agent was applied was used, and the initial cooling power was measured.

The results are shown in Table 2.

Table 2 Comparative Examples 2 to 5 As a PVA glue, PVA and clay were dissolved in water at a weight ratio of 50:50 instead of the PVA 5ill material in Example 1, and the solid content was reduced. 18wt
The aqueous solution was evaporated, and V-hydric acid was added to adjust the pH to 4.
The initial adhesive strength was measured in the same manner as in Example 1, except that the adhesive adjusted to 5 was used. Table 3 shows the 70-year-old fruits.

Table 3 Example 5 1 wt.
% aqueous solution was applied using a roller so that the coating amount (solid content) was 0.59/〆, and air-dried.

On the other hand, PvA (average degree of polymerization 17
00 degree of saponification 96.57~g6) and a powder blended with boric acid and kaolin in a heel weight ratio of 50:1:50, dissolved in water to a solid content concentration of 16 w
Create an aqueous solution and add stearic acid to adjust the pH.
We prepared a version in which the value was adjusted to 4.5.

This PVA-based glue was applied to the fully automatic type paper 111 (Sanso Iron Works @
T-2S type) was used to apply the coating amount to 309 ed on the single-corrugated board A/(BF2) using normal lamination work, and then the above-mentioned white board to the surface of the paper coated with we sodium was applied. We pasted them together.

Although the operating speed was increased to 110 V, sufficient operation was possible even if the pressure bonding time after gold paper was within 1 minute. In addition, a product with good quality was obtained.

Comparative Example 6 The same equipment and the same glue as in Example 5 were used, except that the white cardboard was not coated with sodium carbonate.

When the lamination work was carried out in the same manner as in Example 5, the voltage was 60V.
Embodiment 6. When the speed reached 10 minutes, it was necessary to take more than 2.5 minutes to bond the gold paper due to insufficient initial adhesive strength. Comparative Example 7 Using a Spyful type paper tube manufacturing machine (Okazaki Kikai II T-W type), paper tube base paper (rice device 5009/
From d), a 5-layer film paper tube with an inner diameter of 38 m and a wall thickness of 7.7+W was manufactured.

0.5wt* of sodium carbonate as an alkaline laxative
An aqueous solution was used. In addition, as a pvxi glue, PV'A
(degree of uniform grinding 1800, degree of saponification 88 mol%) and the ratio of boric acid to kaolin was 50:1:7 in terms of IT ratio.
The powder blended at a ratio of 0 was dissolved in water to obtain an aqueous solution having a solid content concentration of more than 28 wt.

First, the above-mentioned sodium cape acid water solution was applied to the four parts of the paper tube base paper at a ratio of 0.59/t (
Solid content). Next, Blind Mountain Tsune's Paper Tube II
I! ! According to the manufacturing process, the PVA-based paste was applied to the untreated surface of the paper tube base paper at a coating amount of 55 mm/#/ to manufacture 9 paper tubes. As a result, good paper tubes were obtained even at q rotation speeds of 800 r, p, and m.

When 11 paper tubes were made using Moeki base paper that was not treated with +7um, the initial adhesion remained good even when the operating speed was lowered to 60 Or, p, m. It was impossible to manufacture paper tubes.

Special Pestle Deneto Unitika Co., Ltd.

Claims (1)

[Claims] +1) When adhering paper to paper, an alkaline agent is applied to one of the adhesive surfaces of 9 papers, and the other adhesive surface is applied. It has the property of thickening in alkaline conditions, and its pH is 71.
4. A method for adhering paper, characterized in that the paper is bonded by increasing the viscosity of the polyvinyl alcohol-based glue by laminating both sides of the polyvinyl alcohol-based glue kept under RT.