JPS5817183A - Adhesive for production of corrugated board - Google Patents

Abstract

PURPOSE:To provide the titled adhesive having a high solid content without suffering from increase of viscosity and lowering of adhesive strength, prepared by adding a specified amount of a filler to a base adhesive consisting of a starch paste solution and an aqueous suspension of starch. CONSTITUTION:The adhesive is of a stain-hole type consisting of a mixt. of a starch paste solution and an aqueous suspension of a starch with the ratio of starch to water ranging 45.0-1.85, and containing 10-60% filler based on the weight of the starch. The filler should pref. have an average particle size of 1-15mu. When the average particle size is less than 1mu, a high concentration adhesive becomes too viscous to be used on the conventional production equipment and when it exceeds 15mu, the adhesive layer formed is poor in strength and consequently bonding strength of corrugated board is lowered. This tendency is esp. remarkable when the filler has a particle size larger than that of starch.

Description

DETAILED DESCRIPTION OF THE INVENTION This article relates to the adhesive for producing corrugated board produced by the present invention. For making roux - related to adhesives.

In the production of general KR&R, adhesive made by Stein Hall 2 and Kuden main yarn is used. This adhesive uses a carrier made by monopolizing starch with caustic soda and giving it viscosity.It is possible to increase the viscosity without causing a large amount of starch to settle. It has the characteristic that a thick paste liquid can be obtained.

However, the solid content concentration 1 of the adhesive produced by this method is about 20X, and in special cases, 42sX am is higher than this, so if the concentration is higher than this, the viscosity of the glue or liquid will be high (too much paper). This will hinder operations.

In general, the four viscosity ranges that do not interfere with operation are preferably 20 to 50 seconds (at 40°C), preferably 30 to 40 seconds, using the Dongdan Houd Cup method (hereinafter, viscosity will be expressed as the Dongdan Houd Cup method). It is called. This Kume Stainohole type adhesive has a problem due to the fact that it has a low AT and a large amount of water must be removed by evaporation during lamination with a corrugator. Problems with wrinkles during meetings, lamination speed t-ToF due to the need for a large amount of heat
This is one of the causes of warping due to rapid evaporation of water and quality problems such as washing boards.

Among these, the problem of wrinkles when using a liner with a low basis weight is particularly important.

In recent years, in order to reduce packaging costs, there has been rapid progress in reducing the weight of base paper used for corrugated boxes. However, if a low-basis corrugated board paper, especially a liner base paper with a 160 yen basis or less, is used in the production of corrugated board, the corrugated board surface will be wrinkled and the frame will be dense.
C@ occurs, exhibiting extremely poor appearance and causing printing defects in subsequent processes, resulting in a significant decrease in product value.

When double-sided corrugated board is made using low basis liner base paper, wrinkles mainly occur in the drying section during the corrugated board manufacturing process, especially in 77 Glue 7 A! - side liner W, I11
The reason for this is thought to be as follows. That is, the moisture in the adhesive applied to the corrugated top of the core base paper by the double facer evaporates in the drying section, and the evaporated moisture moistens the liner base paper on the single facer side on the opposite side. As a result, the single facer side liner partially stretches and does not return to its original shape even after subsequent drying, resulting in wrinkles.

Double facer and drying process are not used when making single-sided corrugated cardboard, but single 7 Acer allows moisture to be added by glue and heat evaporation in a short time, and it is not possible to make double-faced corrugated cardboard, etc. As expected, the liner will stretch partially, causing wrinkles.

The issue of lamination speed is also important. The maximum lamination speed in the production of dust-containing double-sided corrugated poles is approximately 200 m/min, but the main reason why the lamination speed t-S cannot be increased is the use of stain hole adhesive. That is, the Stinhole adhesive has a low solid content, and most of the heat required for producing double-sided corrugated board is consumed for evaporation of adhesive moisture.

Conventionally, in order to solve these problems, for example, synthetic resin adhesives such as vinyl acetate emulsion, styrene butadiene latex, or various modified starches were used. Attempts have been made to manufacture adhesives.

However, these adhesives are generally expensive and
There are operational problems such as the need for special equipment during the preparation of the adhesive and its actual application, and no significant improvement has been seen.

The inventors of the present invention have conducted extensive research in order to improve this drawback, and have found that by adding a certain percentage of filler to the conventional Stainohole adhesive, the solid content am can be reduced without increasing the viscosity. It was discovered that the adhesive strength can be increased, and that the adhesive strength does not decrease at all within this range, leading to the present invention.

That is, the present invention applies to a stainless steel adhesive made by mixing a starch gelatinized liquid and a starch aqueous suspension.
0% to 10% to 60% by weight of filler must be contained in the mold manufacturing adhesive.
It is something to do.

It is known to add fillers to the adhesive for the stem yarns, as described in Stinehall's Patent No. 13G266.

However, as is clear from the description, the purpose of adding filler in this example is not particularly necessary, but is to prevent the mixture from becoming bulky, such as starch, etc. Therefore, the filler content in the starch is extremely low at less than 8%.In contrast, in the present invention, the starch water ratio of the adhesive is 4% or less.
．． 5O-L85, and the filler content t10 to 60% by weight based on the starch, the paper viscosity tt20 to 50.
The viscosity of the adhesive does not increase at all, and the adhesive strength does not decrease at all. 1
increasing with a certain beat as shown in the figure, the second
As shown in the figure, it was completely unexpected that when the solid content #IIl was increased, the evaporation of adhesive water became very slow.

Figure 1 shows the relationship between the starch filler content and amount and the permanent adhesive strength of Kouki balls when corrugated poles are manufactured using this adhesive and the starch double water wheel of the adhesive is constant. There is a peak in adhesive strength when the filler content relative to starch is 30 times IN.

In addition, 1ml is a comparison of the evaporation rate of adhesive water when the adhesive is heated at the same temperature for the same time.The higher the solid content #I, the slower the evaporation rate.

In the adhesive of the present invention, the water soaking rate of starch is 185 to 10 SO, preferably 23 to 10, and the water rate is 1.
If the viscosity of the adhesive is less than 85, the viscosity of the adhesive may be too high, which will hinder operation, and if it exceeds 9, the solid content of the adhesive may not be sufficiently high. The filler used is not particularly limited as long as it is generally used as a filler, but for example, heavy calcium carbonate, precipitate, etc. Mention may be made of inorganic fillers such as calcium carbonate, clay, and common organic fillers.The fillers are added in an amount of 10 to 60% by weight, preferably 10 to 40% by weight, based on 100 weight of starch!XK.

If the amount is less than 10% by weight, the concentration effect cannot be achieved, and if it exceeds 60% by weight, the desired initial adhesive strength and permanent adhesive strength cannot be obtained.

The filler preferably has an average particle diameter of 1 to 15 tones. If the average particle diameter is less than 1/2, the adhesive will change to a high #I, and if the viscosity of the adhesive increases, it will be difficult to use the current AM equipment. On the other hand, if the average particle diameter exceeds 15 tones, the strength of the formed adhesive layer itself becomes weak, and the adhesive strength R of the cardboard is reduced. This tendency is particularly noticeable when the filler particle size is larger than the particle size of the ship.

The adhesive for making corrugated bars of the present invention is made as follows.

First, a portion of starch is suspended in water, caustic soda is added, and the mixture is heated to about 60° C. to gelatinize the starch and form a portion of the carrier. Separately, suspend the remaining starch in water and use it as the main portion. Thereafter, both are mixed and stirred to form an adhesive for manufacturing corrugated board.

In this case, the filler can be added to either the carrier part or the main part, or it can be divided into two parts and added to both, but most commonly it is added to the main part due to operability. It will be done.

The adhesive for manufacturing corrugated board of the present invention includes borax, which is commonly used.
Additives are added as necessary.

When the adhesive for producing corrugated poles of the present invention is used for laminating corrugated poles, the following effects can be obtained.

b) If a low basis weight liner is laminated, wrinkles can be prevented because there is little evaporated water and the evaporation process is slow.

1) Since there is less water to evaporate, the lamination speed can be increased.

c) Improving general cardboard quality. It is possible to greatly improve the warping and washer of cardboard caused by evaporated water.

2) Energy saving.

Next, the present invention will be explained in more detail using practical examples.

Example 1: Suspend 56 parts by weight of starch in 250 parts by weight of warm water, and add 1 part by weight of caustic soda starch to 20 parts by weight while stirring thoroughly.
Gradually add an aqueous solution of caustic soda dissolved in 6 parts by weight of water until the corn starch is completely dissolved and gelatinized.
180 parts by weight of warm water at 0 to 10°C was added and thoroughly stirred to form part of the carrier. Separately, 640 parts by weight of water, 2 parts by weight of gastric soda L, 1 part by weight of borax, 90 parts by weight of heavy calcium carbonate, and 392 parts by weight of Tomoro Zeta starch.
The weight part was tIl#II, the main part was mixed with Toshitomo, and the main part and a part of the carrier were mixed to prepare an adhesive for corrugated board. The viscosity of this adhesive was measured at 40° C. using a Higashi Dan-Hord cup.

Next, using this adhesive, the following lamination test was carried out on a normal corrugated adhesive.

a) Base paper composition Kraft liner 100f/m'/
Sap Core 12517d/Kraftliner Zoo Cap Temperature of corrugated roll and hot plate: 150°C Stable lamination speed with double Betzger was measured, and the occurrence of wrinkles in the corrugated board was visually observed.

Base paper composition: Kraft liner 220v/d/s
ap mill core 125 4♂/craft liner 2201
Temperature of roll and hot plate: 180°C Stable lamination speed with double adhesive and amount of glue applied with double adhesive were measured, and permanent adhesive strength of corrugated board was measured based on tJ-8Z 0402. .

The results are shown in the table.

Example 2 An adhesive was prepared in exactly the same manner as in Example 1 except that the amount of heavy calcium carbonate in the main part in Example 1 was 180 parts by weight, and adhesive and lamination tests were conducted in the same manner. Ta.

The results are shown in the table.

Example 3 Adhesion was carried out in exactly the same manner as in Example 1, except that 5701 was placed in the main part of the water in Example 1, 51.2 parts by weight of heavy calcium carbonate, and 200 parts by weight of corn starch. Adhesive and lamination tests were conducted in exactly the same manner.

The results are shown in the table.

Example 4 In Example 3, an adhesive was made in exactly the same manner as in Example 3, except that the amount of primary calcium carbonate in the main part was changed to 1024 coulometric parts, and adhesive and lamination tests were conducted in the same manner. A friend of mine.

The results are shown in the table.

Example 5 An adhesive was prepared in exactly the same manner as in Example 1 except that tt-498 weight of starch in the main part in Example 1 was used as part, and an adhesive test was conducted in the same manner as in Example 1.

The results are shown in Table 1.

Comparative Example 1 An adhesive was prepared in exactly the same manner as in Example 3, except that the amount of heavy calcium carbonate in the main part was reduced to zero, and adhesive and lamination tests were conducted in the same manner. Ta.

The results are shown in the table.

Comparative Example 2 An adhesive was made in the same manner as in Example 1, except that the main part of Example 1 was borax T-&9 parts by weight, corn starch at 560 parts by weight, and the amount of heavy calcium carbonate at zero. Adhesive and lamination tests were conducted in exactly the same manner.

The results are shown in the table.

As is clear from the table, when corrugated cardboard is laminated using the adhesive of the present invention, the speed at which it can be stably laminated is significantly increased, and the permanent adhesive strength is also improved.

Furthermore, in the case of lamination using a thin liner such as Kraft Liner 1 o o f/d, there is a remarkable effect in preventing wrinkles.

Note that Comparative Example 2 has a high viscosity and poor operability, so the lamination speed t cannot be reduced.

[Brief explanation of drawings]

Figure 1 is a graph showing the relationship between starch filler content and permanent adhesive strength of corrugated board. Figure 2 is the adhesive temperature and evaporation rate of adhesive moisture when the solid content of #i adhesive is varied by 11 degrees. This is a graph showing the relationship between Tokushin Yamaganjin Honshu A Paper Co., Ltd. Figure 1 Puller - Including Jt (%)

Claims (1)

[Claims] (1) In the stainless steel adhesive made of a mixture of starch gelatinization liquid and starch water 5fI4 liquid, the starch-water soaking rate is 450-L85, starch 106
Adhesive for manufacturing corrugated poles containing 10 to 60% by weight of filler. a) The adhesive for producing corrugated board according to claim 1, wherein the filler has an average particle size of 1 to 15P.