JP2000041500A - Base paper for nursery container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject base paper composed of a multilayered structure and capable of maintaining the form during the period of seedling raising and rapidly decomposing a container after planting a seedling together with the container into soil after raising the seedling without any fear of environmental pollution such as a disposed plastic container by including a specific amount of a mechanical pulp in the outermost layer and a specified amount of a nonmechanical pulp in the outermost layer on the opposite side. SOLUTION: This base paper for a nursery container consists essentially of cellulosic fibers and is composed of a multilayered structure of two or more layers. The outermost layer contains >=20 wt.% of a mechanical pulp and the outermost layer on the opposite side contains >=80 wt.% of a nonmechanical pulp. At this time, the constituent ratio of the layer containing >=20 wt.% of the mechanical pulp is preferably 20-80 wt.% and the constituent ratio of the layer containing >=80 wt.% of the nonmechanical pulp is preferably 80-20 wt.%. A resin layer having heat sealability and water resistance is preferably formed on the side of the layer containing >=80 wt.% of the nonmechanical pulp.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a base paper for a seedling container used for a seedling container in the field of agriculture or horticulture, which retains the shape of the container during the seedling raising period and can be transplanted into the ground as it is after the seedling raising. And biodegradable immediately after transplantation.

[0002]

BACKGROUND OF THE INVENTION As a container for breeding for agriculture and horticulture, it is inexpensive and has relatively good durability. Therefore, containers for raising seedlings made of plastic such as vinyl chloride and polyethylene have been used. I have. These containers are discarded as garbage when the seedlings are transplanted to the alley after the seedlings are raised and disposed of by landfilling or incineration. However, containers are plastics that have little biodegradability even when discarded in a landfill or the like. Therefore, there are problems in appearance such as restriction of use after landfill and plastic on the surface being scattered without being decomposed forever. In addition, combustion disposal has a high combustion temperature and it is easy to damage the furnace,
In the case of vinyl chloride, dioxin is generated depending on combustion conditions, which is problematic in terms of environment and health.

Although various paper-based seedling containers (pots, pots) have been proposed, chemicals for controlling the biodegradation resistance of easily biodegradable cellulosic fibers may be added during papermaking. A method of performing a treatment such as coating and impregnation on a paper sheet is disclosed. For example, in JP-A-8-116796, humic acid, nitrohumic acid,
One or two selected from regenerated humic acids and their salts
There is disclosed a seedling transplanting paper pot manufactured from paper to which seeds or more are added during papermaking. JP-A-8-116797 discloses that in addition to one or more selected from humic acid, nitrohumic acid, regenerated humic acid and salts thereof, a fungicide 8-
There is disclosed a seedling transplanting paper pot in which the outer side of the container is manufactured from paper to which copper oxyquinoline is added. JP 9-2944
No. 81 discloses a seedling transplanting paper pot manufactured from a wax emulsion or a paper added in combination with a wax and a fungicide to control the degradability. These are methods of controlling biodegradability by adding a chemical having an antibacterial action such as humic acid or wax to base paper.
These antibacterial agents suppress the activity of microorganisms in the soil that are effective for plant growth.

Therefore, there is a demand for a container for raising seedlings which is inexpensive and satisfies the seedling raising performance and has no disposal problem, such as a plastic container, but has not yet been commercialized.

[0005]

SUMMARY OF THE INVENTION According to the present invention, the shape is maintained like a plastic container during the seedling raising period, and after the whole container is planted in the ground after the seedling raising, the container is rapidly decomposed and the seedling is planted. Later, the task was to develop base paper for nursery containers used for nursery containers that would not cause environmental pollution such as plastic containers to be discarded.

[0006]

Means for Solving the Problems Wood-based fibers are generally known as fibers having relatively good biodegradability. However, the present inventors have proposed a biodegradable fiber based on the type of wood-based fibers in order to solve the above problems. We focused on the difference. That is, it has been found that mechanical pulp is relatively hard to biodegrade and non-mechanical pulp is relatively easy to biodegrade. Utilizing the difference in biodegradability depending on the type of raw pulp, the innermost layer that is in direct contact with the soil when raising seedlings is provided with a layer containing at least 20% by weight of biodegradable mechanical pulp. The outermost layer that does not come into direct contact with the paper has a multi-layered structure composed of a layer containing at least 80% by weight of non-mechanical pulp with good biodegradability. It has been found that when the plant is directly planted in the ground, the container is rapidly biodegraded, and the present invention has been achieved.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The chemical composition of mechanical pulp and non-mechanical pulp used in the present invention is greatly different. The composition of the main component of the woody portion is composed of a fiber portion mainly composed of cellulose and a lignin portion connecting fibers. Mechanical pulp softens lignin and isolates fibers by mechanical shearing force or heating in addition to mechanical shearing force. For this reason, each fiber is in a state where the fiber portion is covered with lignin. On the other hand, non-mechanical pulp elutes the lignin part by chemical treatment and isolates the fiber. For this reason, the fiber is substantially composed of only the cellulose component.

[0008] Cellulose and lignin are the major natural polymers that make up wood and are degraded by microorganisms. Cellulose has a linear structure in which D-glucose is β1,4-linked and is easily hydrolyzed by microorganisms. On the other hand, lignin has a complicated structure and does not contain a repeating unit which is susceptible to hydrolysis. That is, the decomposition rate of microorganisms is different between the non-mechanical pulp having most of the cellulose component and the mechanical pulp having the surface layer of the fiber covered with lignin.

In the present invention, mechanical pulp is
"Types of paper pulp and their test methods" edited by Japan Society of Paper and Pulp Technology
In accordance with TAPPI Standard Method T-401 shown in the table, when a Wilson dyeing solution was used as the dyeing solution, the fibers dyed yellow were used as mechanical pulp, and the others were used as non-mechanical pulp. More specifically, the mechanical pulp used in the present invention includes groundwood pulp (GP), refiner ground pulp (RGP), and thermomechanical pulp (TM).
P) and chemithermomechanical pulp (CTMP). In addition, the present invention is similarly applied to deinked pulp made from waste paper containing these pulp as a main component.

On the other hand, non-mechanical pulp used in the present invention includes unbleached kraft pulp (UKP), bleached kraft pulp (BKP), unbleached sulphite pulp (USP),
Bleached sulphite pulp (BSP) and the like. Similarly, the present invention is similarly applied to deinked pulp made from waste paper containing these pulp as a main component.

It is preferable to add a wet paper strength enhancer in order to improve wet paper strength as long as the decomposition by microorganisms in the soil is not hindered. As a wet paper strength agent,
Melamine-formaldehyde resin, polyamide / epichlorohydrin resin, polyethyleneimine, glyoxal, dialdehyde starch and the like.

[0012] Fillers may be added as long as they do not hinder the decomposition by microorganisms in the soil. Examples of the filler include white carbon, silica, clay, kaolin, calcium carbonate, titanium oxide and the like.

The base paper for a nursery container of the present invention has a multi-layer structure of two or more layers. In manufacturing, the base paper has water resistance, printability, fungicide, insect repellent, and fertilizer as long as biodegradability can be maintained. It is possible to add chemicals and pigments by internal addition and external addition during papermaking in order to impart functionality such as effects. Further, post-processing such as coating and impregnation can be similarly performed after forming the paper. For example, the internal addition of a fixing agent, a sizing agent, a paper strength improver, a filler, etc., and the external addition of a surface sizing agent, a surface strength improver, a pigment, etc. Impregnation machine in the post-process after paper,
Pigment coating, resin coating, and resin impregnation by a coating machine are conceivable.

Particularly, in order to impart heat sealability and water resistance, a resin layer is provided on the layer side containing at least 80% by weight of non-mechanical pulp by coating or impregnating at the time of paper making or after forming. Is preferred. As resins having good heat sealability and water resistance, styrene / acrylic resin emulsions such as copolymers of styrene and acrylic acid (methacrylic acid) and / or acrylic acid (methacrylic acid) ester, styrene / butadiene, methacrylate・
Butadiene-based, acrylonitrile-butadiene-based copolymer latex-based emulsion, ethylene-vinyl acetate resin-based emulsion, and the like.

The apparatus for producing a base paper for a nursery container of the present invention is not particularly limited, but is generally a multi-layer paper machine generally used for the production of paperboard, or an inner layer and an outer layer are separately formed and laminated by a laminating machine. Any of the known methods, such as conversion, can be used.

The basis weight of the seedling container base paper of the present invention is as follows.
It is preferably from 40 g / m ^{2 to} 400 g / m ² . Basis weight 40g
If it is less than / m ² , the strength and the roughness are low, and when molded into a seedling raising container, the container is cut or crushed when moving or the like, and handling is difficult. On the other hand, if the basis weight exceeds 400 g / m ² , necessary and sufficient strength and cracking can be obtained, but the cost is increased and it is not practical.

In the present invention, 20% by weight of mechanical pulp is used.
The composition ratio of the layer containing the above and the layer containing the non-mechanical pulp of 80% by weight or more is not particularly limited,
20-80% by weight of the layer containing 20% by weight or more of mechanical pulp, and 80-20% of the layer containing more than 80% by weight of non-mechanical pulp
A weight percent composition is desirable. In addition, the blending amount of the mechanical pulp in the layer containing 20% by weight or more of the mechanical pulp is preferably adjusted to a blending rate suitable for the target crop because the seedling raising period varies depending on the type of crop to be cultivated. . That is,
If the seedling raising period is short, the mixing ratio of mechanical pulp should be 20-40.
Wt%, and conversely, if the seedling raising period is long, it is desirable to set the blending ratio of the mechanical pulp to 40 wt% or more.

[0018]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited to these examples.

Example 1 A two-layer multi-layer paper machine was used.
As shown in FIG. 1, the first layer is composed of 50% by weight of GP and 50% by weight of hardwood unbleached kraft pulp (LUKP), and the second layer is composed of 100% by weight of hardwood bleached kraft pulp (LBKP). Two layers were added at a weight ratio of 1: 1. Each layer was added with 2% by weight of rosin-based sizing agent to pulp and 0.4% by weight of an epichlorohydrin-based wet paper strength improver, and the papermaking pH was adjusted to 4.5 with a sulfuric acid band. Paper was made. Acrylic resin emulsion with good water resistance and heat sealability is applied to the second layer surface with a bar blade coater in the intermediate process of the paper machine so as to have a solid content of 5 g / m ^2.
A base paper for raising seedlings consisting of two layers of 150 g / m ² was obtained. Using a paper cup molding machine, the seedling container base paper is heat-sealed at the laminated part of the body so that the second layer of the base paper is on the outside. The part was heat-sealed to prepare a paper cup-like seedling raising container as shown in FIG. To evaluate the performance of the seedling raising container, fill the culture soil into the container, water it once a day in a house with an average temperature of about 30 ° C, leave it for three weeks, transplant it to an alley, and leave it for another month to leave it. The morphology of the container was observed. As a result, in the third week of the seedling raising period, it was possible to maintain the strength and stiffness enough to withstand the movement and to transplant it in the alley without any problems without any problems. When the morphology was observed one month after transplantation, the morphology was hardly maintained and assimilation with the soil was observed.

Example 2 FIG. 2 shows the results obtained by using a three-layer paper machine.
As shown in the figure, the first layer is 100% by weight of deinked pulp of recycled paper containing 60% by weight of mechanical pulp, the second layer is 100% by weight of deinked pulp of PPC paper containing 5% by weight of mechanical pulp,
The third layer is composed of 100% by weight of LBKP, 1 layer, 2 layers, 3 layers
The paper was then made in the same manner as in Example 1 so that the weight ratio of the layers was 2: 2: 1, and the acrylic resin emulsion was solidified to 5 g / m ^{2 in} the same manner as in Example 1. The surface of the third layer was coated so as to obtain a base paper for a nursery container consisting of three layers having a basis weight of 150 g / m ² . In the same manner as in Example 1, a paper cup-like seedling-raising container was prepared from this seedling-raising container base paper so that the third layer of the base paper was on the outside, and evaluation was performed. as a result,
In the third week of the seedling raising period, it was possible to transplant the container as it was in the alley without any problems while maintaining the strength and rigidity enough to move. When the morphology was observed one month after transplantation, the morphology was hardly maintained and assimilation with the soil was observed.

Comparative Example 1 A seedling container base paper was prepared in the same manner as in Example 1, except that the raw material mixing ratio of the first layer was the same as that of the second layer, and the seedling container was evaluated. As a result, a part of the container began to decompose about two weeks after raising the seedlings, and after three weeks, the shape of the cup collapsed, and the mulch in the container was scattered around.

Comparative Example 2 A seedling container base paper was prepared in the same manner as in Example 1 except that the raw material mixing ratio of the two layers was the same as that of the one layer, and the seedling container was further evaluated. As a result, in the third week of the seedling raising period, it was possible to transplant the container as it was in the alley without any problems while maintaining the strength and rigidity enough to move, but it was somewhat softer when observing the form one month after transplantation. However, the shape of the container remained almost as it was.

As described above, Examples 1 and 2 had a sufficient seedling raising function during the seedling raising similarly to the plastic seedling raising containers, and after transplanting to soil, they rapidly biodegraded, and the effect was sufficiently recognized. On the other hand, in Comparative Example 1, the container biodegrades during the seedling raising, and does not function as a seedling raising container. Further, in Comparative Example 2, since the biodegradation is slow even after transplanting into the ground, the shape of the container remains even after one month, so that the growth of the crop may be delayed.

[Brief description of the drawings]

FIG. 1 is a base paper for a nursery container comprising two layers of the present invention.

FIG. 2 is a base paper for a nursery container comprising three layers of the present invention.

FIG. 3 is an example of a sectional view of a seedling container prepared from the base paper for a seedling container of the present invention.

[Explanation of symbols]

 1 1 layer (inside the seedling container) 2 2 layers (outside the seedling container) 3 resin layer 3 1 layer (inside the seedling container) 4 2 layers 5 3 layers (outside the seedling container) 6 resin layer 6 top curl 8 trunk Part 9 Bottom part 9 Hole 10 Body sticking part

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2B027 NC02 NC23 NC24 NC36 NC40 NC44 NC52 ND03 ND09 NE05 4F100 AJ02A AJ02C AK01B AK25 BA03 BA07 BA10A BA10C BA25 CA12 DA01 DG10A DG10C GB01 JB11B JC00 JL12B01AG04AG AG89 AG97 AJ01 AJ02 BD17 BD18 BE14 EA01 EA04 EA08 FA19 FA20 FA30 GA25

Claims (5)

[Claims] Claims: 1. A base paper for raising seedlings mainly composed of cellulosic fibers, comprising a multilayer structure of two or more layers, wherein the outermost layer contains 20% by weight or more of mechanical pulp and the outermost layer on the opposite side is non-mechanical. A base paper for a container for raising seedlings, comprising 80% by weight or more of pulp. 2. The composition containing 20 to 80% by weight of the layer containing at least 20% by weight of the mechanical pulp and 80 to 20% by weight of the layer containing at least 80% by weight of the non-mechanical pulp. The base paper for a nursery container according to claim 1, characterized in that: 3. The non-mechanical pulp of said seedling container base paper
The base paper for a nursery container according to claim 1 or 2, wherein a resin layer having heat sealability and water resistance is provided on a surface on a layer side containing 80% by weight or more. 4. The base paper for a nursery container according to claim 1, wherein the basis weight is 40 g / m ² or more and 400 g / m ² or less. 5. The mechanical pulp of the base paper for the seedling raising container is 20
80% by weight of non-mechanical pulp
A container for raising seedlings, which is formed so that a layer containing not less than% by weight is on the outside.