JPH08154501A - Mulching paper for field crop - Google Patents

Abstract

PURPOSE: To prepare biodegradable mulching paper which can serve as an organic fertilizer after harvesting in no need of its removal. CONSTITUTION: This mulching paper for field cropping is a fluted or embossed wavy sheet of more than 5% elongation and contains 1-15wt.% of starch.The wavy paper is produced by fluting or embossing a base paper of 50-150g/m<2> unit weight, 80-120 seconds sizing, 2.8-5.6km breaking length and 0-5% optical transmittance into 0.3-5.0mm wave height. This base paper includes reused corrugated paper as the core layer and has a shape of either of A flute, B flute, E flute or F flute. The starch is derived from corn, potato, tapioka or other natural polymer and it is combined or coated to the wavy paper in an amount of with 1-15wt.%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is a paper sheet mainly used for weeding, weeding or heat retention in upland cultivation, which becomes an organic fertilizer after the end of harvest and does not require removal. Related to paper.

[0002]

2. Description of the Related Art As an example, conventionally, the following means have been adopted as means for weeding and weeding of upland action. Use of chemicals such as herbicides. The seedbed is covered with a mulching sheet made of a plastic film such as polyethylene. Use of mulching paper (mostly imported) made mainly from softwood and kraft cooked pulp.

Japanese Unexamined Patent Publication No. 6-78659 (hereinafter, conventional example A)
Has a thickness of 0.08-0.
30 mm, basis weight 35 to 160 g / m2, wet tensile strength 0.20 to 2.00 kgf / 15 mm width, and the result of using the base paper made so that the stext size degree is 15 seconds or less. Hold the sheet for days,
It is disclosed that the solution disappears in 50 to 70 days. Also,
An example is described in which waste paper from corrugated board is used as a raw material, a chemical is not added, and papermaking is performed with a paper machine at a basis weight of 120 to 160 g / m 2. In addition, there is a description that kraft pulp is used as a paper material, no chemicals are added, and papermaking is performed with a paper machine at a basis weight of 50 g / m 2.

On the other hand, Japanese Patent Application Laid-Open No. 60-250949 (hereinafter referred to as Conventional Example B) discloses a crepe paper core material having a standard weight of about 30 to 80 g / m 2 and an elongation of about 5 to 15%, and A mulching sheet formed with a coating having a dry residue of a vinylidene chloride latex dispersion is disclosed.

Further, JP-A-6-16834 (Conventional Example C) has a breaking length in the range of 0.80 km and less than about 6.20 km, and the base web is a dried fiber base web containing cellulosic fibers. Disclosed is the case of forming a web composite treated with an impregnant-containing latex supplemented with about 16 to about 80 parts by weight of the impregnant. The web composite has a strength of about 50 kg / cm 2 and about 0.2-0.6.
The wet strength to dry strength ratio of the latex is about −
Biodegradation present in the latex web composite at a ratio of synthetic polymer to natural polymer having a glass transition temperature in the range of 50 to about 20 ° C. and about 2: 1 to 4: 1 based on the total weight of the polymer. It is described that it is a sheet material having good properties, is microcreped, and the natural polymer is selected from starch, protein and natural rubber.

[0006]

The above-mentioned conventional example has the following problems. Residual pesticides adversely affect local communities and contribute to environmental damage. In addition, there are many problems such as residual pesticides being detected in crops after harvest. When the temperature rises, the film stretches due to heat reception,
The seedling and the film come into contact with each other, resulting in poor growth. Even in the fallow period after harvesting, if the soil temperature is relatively low as in Hokkaido, the rate of weathering and hydrolyzing in the soil is slow, and decay and incomplete decomposition parts remain at the time of planting. Requires removal work.

Further, Conventional Example A is a mulching sheet for paddy fields, and as a strength adjusting agent for the stexite sizing degree and mulching paper, it is obtained from natural paper strengthening agents such as corn, potato, tapioca and the like. Starch is desirable, and it is described that it is unsuitable for paddy fields if the addition rate of 10% by weight or less is not controlled by internal addition, external addition spraying or coating, and it is unsuitable for paddy fields. The period is extremely long, 50 to 70 days.

On the other hand, the conventional example B is a composite sheet, in which both sides of a core material of crepe-like natural kraft paper are coated with an aqueous dispersion or latex of polyvinylidene chloride, which only increases the manufacturing cost. Without crepe paper,
It has poor tensile strength and is prone to breakage, requiring a period of 3 months for biodegradation.

Further, in Conventional Example C, latex is used as in Conventional Example B. In particular, as a farmland cover mulch, a cellulosic web of softwood kraft fiber, 42
In combination with a case of saturated with a latex emulsion of carboxylated styrene-butadiene rubber containing wt% bound styrene-butadiene rubber, and a cellulose web of softwood kraft fibers in a ratio of 85:15 with polyester fibers of denier 3-6 mm. The examples of use are described, and all of them are used for agricultural land, and synthetic resins are used to increase the tensile strength, and they have poor biodegradability and have the drawback that it takes a considerable number of days to dissolve.

As described above, the above-mentioned conventional example is not developed as a field action, and so-called polymulch such as polyvinyl chloride film is exclusively used for the field action, and it is necessary to remove it after harvesting. It was

In addition, in mulching paper, in order to improve the decay and incompletely decomposed parts, it is attempted to apply several decay accelerators such as yeast, nitrogen, phosphoric acid and potassium as nutrient sources. However, due to the excessive weathering of the paper during the covering period, that is, the timing difference between the covering period and the rotting period and the adverse effect on the crops, the problem could not be resolved.

By the way, the growing period of seedlings is 30 to 50 days, and it is necessary to cover the seedlings during that period, but the mulching paper was repeatedly wetted and repeated in a natural environment, and a rupture phenomenon due to expansion and contraction occurred. Then, after the breakage, the air flowed from the breakage place and the covering became impossible, and the original purpose of the mulching paper could not be achieved.

On the other hand, most of the existing mulching papers for upland field are imported products, and domestic products are covered by diversion of hydroponic base paper. For imported products, depending on the type of raw wood and the pulping method used for softwood and kraft pulp, it depends on the basis weight at the time of paper making, but at 50 g / m2 or more, long fibers cause weathering and hydrolyzation in the soil. The speed was slow, and the pulp fibers were often incompletely decayed at the time of planting after fallow, and it was necessary to remove those portions.

[0014]

The present invention has an elongation of 5%.
The above-mentioned flute- or embossed corrugated paper is a field-effect mulching paper containing 1 to 15% by weight of starch. The corrugated paper has a basis weight of 50 to 150 g / m2,
Size degree 80-120 seconds, breaking length (longitudinal direction) 2.8-
A base material having a height of 0.3 mm to 5.0 mm and having a light transmittance of 0 to 5% is formed by flute or embossing, and the base material is made of corrugated cardboard waste paper. This is a core paper for use in any one of A flute, B flute, E flute and F flute shapes. further,
The starch is a natural polymer such as corn, potato and tapioca, which is contained in corrugated paper in an amount of 1 to 15% by weight.
Internally added or applied. And, in the present invention, after applying 10% starch, this starch acts as a paper strength agent during the laying period in the field, and after harvesting, it exerts a function of doubling the decay rate about twice. It is a characteristic field action mulching paper.

[0015]

The corrugated paper has a large required expansion degree of 5% or more, and has a cushioning property of absorbing the amount of expansion and contraction in the shape of the paper to enhance the tensile strength and wipe out the breaking phenomenon. Furthermore, by internally adding or applying starch to the corrugated paper, the starch acts as a paper-strengthening agent during the covering period, and becomes a nutrient source for bacteria in the soil after harvesting, greatly promoting weathering and hydrolysis. , It has about twice as fast decay rate as uncoated paper. In addition, cost reduction was achieved by using corrugated paper made from corrugated waste paper.

[0016]

EXAMPLE The present invention is a mulching paper mainly used for upland farming, which has a specific size degree, a light-shielding property, in order to prevent tearing during agricultural machine transplanting work, a predetermined number of days, and a covering function.
Has tear strength.

Incidentally, the base paper constituting the present invention may be softwood or kraft pulp, but the one using corrugated cardboard waste paper is advantageous in various conditions such as strength and cost. The field-effect mulching paper of the present invention has a basis weight of 50 to 150 g / m.
2, size degree 80-120 seconds, breaking length (longitudinal direction) 2.8
A base material within a range of ˜5.6 km and a light transmittance of 0 to 5% was flute (corrugated) processed by a corrugating machine to form a base paper. Further, in the mulching paper of the present invention, starch (corn, tapioca, potato) or a similar polysaccharide substance was internally added or applied in the range of 1 to 15% by weight in the papermaking process of the base paper and the like.

Next, a test example of tensile strength using this base paper will be shown. -Test 1 ---------------------------------------- Sample Tensile strength (longitudinal / kg) Elongation (%) 1. Base paper A 7.8 1.8 2. Base paper B 12.0 2.0 3. A flute processed paper of base paper A 7.5 13.0 4. B flute processed paper of base paper A 7.3 10.2 5. E-fluted paper of base paper A 7.2 10.0 6. F-flute processed paper of base paper A 7.0 8.2 7. A flute processed paper of base paper B 9.7 10.5 8. E-flute processed paper of base paper B 9.5 10.2 9. F-flute processed paper of base paper B 9.3 8.6 10. Embossed paper of base paper A 7.1 5.1

Base paper A: A core base paper for corrugated board having a strength level of a general core. Raw material composition is 100% Japanese dan, basis weight 115 g / m2, tensile strength 7.8 kg. Base paper B: base paper specially made for paper mulching, raw material composition is 100% western dan (softwood, waste paper of kraft cooked pulp) With a basis weight of 115 g / m2 and a tensile strength of 12 kg, it is 1.5 times stronger than base paper A.・ Embossed shape is 5mm pitch, 0.3m height
m, diameter 2 mm, prototype manufactured for this base paper, and passed through a molding hot roll (140 ° C., linear pressure 30 kg / cm). It was moistened to a water content of about 15% and molded and dried on a hot roll.

[Test method] 15 mm in 18 cm span
The width of the paper was sandwiched and wet (immersion in water) and drying (in an electric constant temperature dryer set at a temperature of 105 ° C.) were repeated 5 times.

[Test Results] All of the unprocessed base papers (samples 1 and 2) were broken, and the processed papers (samples 3 to 10) were not broken. In addition,
Although the degree of stretch of the A-flute processed paper was sufficient, it was difficult to secure the stability of the corrugated sheet at the time of winding, so when using it,
Further ingenuity is needed.

-Test 2 (laying in field) --------------- Sample-Extension (%) 1. Base paper A 2. Base paper B 3. A flute processed paper of base paper A 3.1 4. B flute processed paper of base paper A 5.8 5. E-flute processed paper of base paper A 6.4 6. F-flute processed paper of base paper A 6.9 7. Embossed paper of base paper A 5.1 8. Base paper A F flute processed paper 6.9

[Test Method] The mulch base paper was actually laid in the above-mentioned extension level in the field, and seedlings were transplanted to confirm the presence or absence of breakage and the situation.

Agricultural products Chinese cabbage Construction length 100 m Observation after 50 days

[Test Results] Base papers A and B (unprocessed) were broken. No fracture phenomenon was observed in the B, E, and F flute processed products and the embossed product, but the 3.1% elongation product was the limit as judged from the paper tension. This is because when the paper begins to dry after it has become wet due to rain,
If uniformly dried, the shrinkage will be absorbed in the shape of the paper,
The soil is not flat but has irregularities, and water remains in the recesses, causing variations in paper moisture. In addition, (paper-
It is thought that the frictional resistance between papers will also increase. Therefore,
Considering safety, if the degree of stretch of the base paper is 5% or more, it can withstand even severe conditions.

-Test 3 (rotation speed) --------
--------------------------- Sample 1. Craft and base paper 2. Corrugated cardboard waste paper / base paper 3. TMP base paper (chips are heated to about 120 ° C beforehand,
3. Mechanical pulp obtained by softening wood and then pulping it with a refiner) 4. Magazines, newspaper base papers 5. GP base paper (rough paper, etc.) 6. 6. SCP base paper (uses hardwood, high yield, high pentosan content, high rigidity and density, reduces opacity due to beating. Unbleached paper is used for corrugated cardboard cores, etc.) 7. AP base paper (soda pulp)

1) The base paper was prepared by hand. The handmaking conditions are the same for all seven types and are as follows. -Basis weight 100G / m2-Freeness F = 350ml-Size degree 110 seconds

[Test Method] A beaker, in which a predetermined amount of soil and water were sampled, was placed in a constant temperature / humidity chamber (setting / temperature: 35 ° C., humidity: 100%), and a sample was placed on the beaker. I sprinkled the soil. It was observed 40 days in total. The degree of decay of the paper was determined every predetermined number of days by the naked eye and the touch of the finger (the decayed portion of the paper is affected by microorganisms, the connection between fibers disappears and becomes a moist powder).

[Test Results] -The decay of starch (starch) -free products is slow,
The craft type was the most delayed. The kraft product finally changed into a moist powder state on the entire surface of the paper after 40 days of standing.・ Regarding the base papers of samples 2 to 7 other than craft type,
The entire paper became decayed in 30 to 35 days, but the decay of the long fiber portion in the corrugated cardboard waste paper is delayed. From these results, it is considered that kraft-type long fibers are essentially resistant to decay. -The effect of promoting decay by applying starch is remarkable, for example, 1
With 0% coated paper, the kraft paper was completely decayed in 20 days and the other samples were also degraded in 17 to 18 days. Therefore, it can be said that the application of starch doubled the decay speed.

In order to confirm the above test results, the following three types were selected from the samples, and the used mulching paper and soil were mixed at the agricultural machine rotary after harvesting, and the fallow period, that is, from autumn to spring of the next year. It was left for about 5 months.

Sample Base paper A Corrugated cardboard waste paper with 5% starch applied Base paper B Craft type without starch applied F flute processed paper of base paper A Corrugated cardboard waste with 10% applied starch

[Test Results] Regarding the decay state of the mulching paper for 5 months, with respect to the base paper B (without kraft type starch coating), incomplete decay portions were scattered, and the results of Test 3 were confirmed.

5 of base paper B and base paper A F flute processed paper
%, The 10% starch-coated product was completely decayed, and the fiber shape could not be found, and it was in a state of being reduced to soil.

As described above, according to the present invention, as a result of containing 1 to 15% by weight of starch in the corrugated paper having an elongation of 5% or more,
We were able to provide mulching paper with field action that decays at twice the speed of conventional ones. Further, according to the constitution of claim 2, not only the tensile strength is excellent and the laying work such as the agricultural machine transplanting work can be efficiently performed, but also the strength is maintained after the laying, whereby the function as the mulching is sufficiently exerted. further,
According to the structure of claim 3, not only is there a cost advantage, but it also has better extensibility than crepe paper. Furthermore, the embossed material also exhibits the same tensile strength as the flute processing. In addition, the embossed product is
Not only does it have the same extensibility as the flute-processed product, but it is also possible to firmly and consistently wind the base paper during embossing, regardless of the height of the corrugation. Therefore, the winding does not come apart and the bamboo is not wound into a bamboo shoot. As a result, there is an advantage that not only the handling at the time of transportation and loading is easy, but also there is little concern at the time of laying. Furthermore, mulching paper coated with 10% starch was laid in the field, and after harvesting, the speed of soil decay was about 2 compared to uncoated paper during the decay period.
It doubled in speed and became a completely organic fertilizer after decay.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masahiko Kobayashi 1-4, Yamanote 1, Yamanote, Nishi-ku, Sapporo, Hokkaido 1-602 (72) Takenosuke Otani 1-1-404, Suehiro, Ichikawa, Chiba (72) ) Inventor Masamitsu Tomita 12-5 Nishi 4-jo North, Nayoro City, Hokkaido

Claims (6)

[Claims] 1. A field action mulching paper comprising 1 to 15% by weight of starch in a flute or embossed corrugated paper having an elongation of 5% or more. 2. The corrugated paper has a basis weight of 50 to 150 g / m 2.
2, size degree 80-120 seconds, breaking length (longitudinal direction) 2.8
2. The field mulching according to claim 1, wherein a base material within a range of .about.5.6 km and a light transmittance of 0 to 5% is processed into a corrugation having a height of 0.3 mm to 5.0 mm, and has an elongation of 5% or more. paper. 3. The field action mulching paper according to claim 2, wherein the base material is a corrugated fiberboard core paper made from corrugated cardboard waste paper and has any one of A flute, B flute, E flute and F flute shapes. . 4. The field working mulching paper according to claim 2, wherein the base material is embossed with a pitch of 5 mm, a height of 0.3 mm and a diameter of 2 mm, using a corrugated cardboard waste paper as a base paper. 5. The upland action mulching paper according to claim 1, wherein the starch is a natural polymer such as corn, potato and tapioca, which is internally added or applied to corrugated paper. 6. The method according to claim 1, wherein after applying 10% starch, it acts as a paper-strengthening agent while laying in a field and, after harvesting, exhibits a decay rate about twice that of uncoated paper. The described field action mulching paper.