JPS595300Y2 - Agricultural or forestry string - Google Patents

Description

[Detailed description of the invention] This invention relates to a string used for agriculture or forestry.

For agricultural or forestry use, it is desirable to have something that will naturally rot or decompose, like straw rope, if left outdoors for a certain period of time.

Focusing on this point, agricultural paper that is particularly susceptible to aging by ultraviolet rays has been proposed.

Japanese Patent Publication No. 53-20414 describes the string.

The publication describes that by adding an embrittlement accelerator to a synthetic resin and foaming the synthetic resin to form a foam and making a string from this, a string that is easily embrittled can be obtained.

On the other hand, a special type of forestry cord is called kiori paper.

This string is used in regions with a lot of snow to prevent young trees from falling under the pressure of snow.

Specifically, this string is tied between the young tree and the bottom tree,
The traction force from the mature tree prevents the young tree from falling over.

This string becomes unnecessary once the snow season ends and the weather gets warmer.

When the weather gets warmer, this string not only becomes unnecessary, but also hinders the growth of young trees.

Therefore, it is necessary to use this string only during the winter and remove it from spring to summer.

However, attaching and removing the string is a troublesome work, so even if it is necessary to attach it, removing it is a labor-intensive task.

Therefore, it was desired that the string would naturally age and break after a certain period of use.

This inventor added an embrittlement accelerator to various synthetic resins and foamed the synthetic resin by adding a foaming agent, and attempted to make the above-mentioned wood-raised paper using this foam as a material.

As a result, the inventor confirmed that olefin resins become brittle or age particularly quickly, and that the cross-sectional shape of the string is a contributing factor to the accelerated brittleness or aging of the string.

That is, in the above-mentioned Japanese Patent Publication No. 53-20414,
Although the shape of the string was not taken into consideration at all, it was confirmed that if the cross-sectional shape of the string was set appropriately, the wood-raised paper would quickly become brittle and break.

This idea was made based on such confirmation.

This idea focuses on the fact that olefin resins have a high deterioration property, so olefin resins are selected as the material, and the strings are made into flat strips, but the thickness is not uniform, and the strings are made in the width direction. The main idea is that the cross section is bead-shaped, with thick and thin parts alternately provided.

This idea consists of a foamed olefin resin containing a deterioration accelerator, and in a string-like object made by forming this into a long belt-like body, the cross-sectional shape is formed into a bead-like shape, and the thick part is The present invention relates to a string for agricultural or forestry use, which is formed by alternating thick and thin parts.

An example of implementing this invention will be described below with reference to the drawings.

1 and 2 are partially cutaway perspective views of the string according to this invention.

In FIGS. 1 and 2, 1 and 3 are thick parts, and 2 and 4 are thin parts.

These thick portions and thin portions are both made of an olefin resin foam containing a deterioration accelerator, and are connected to each other to form an integral body.

In the example shown in FIG. 1, the cross section of the thick portions 1 is approximately square, and the thin portions 2 connect the thick portions 1.
The cross section of is rectangular.

In the example shown in FIG. 2, the cross section of the thick part 3 is almost circular, and there is a thin part 4 between each thick part 3, but the cross section of the thin part 4 has almost no width. It has become a valley of not having it.

Here, the thickness of the thick part and thin part is appropriately determined depending on the use of the string, but generally speaking, the maximum thickness of the thick part is more than twice the minimum thickness of the thin part. It is preferable that

Therefore, in this case, there is a difference between the thick part and the thin part that is greater than the thickness of the thin part.

Further, the width of the thick portion is preferably approximately half to twice the thickness of the thick portion.

As for wood-cut paper, the thickness of the thick part is about 1.0 to Q, 4mm, and the thickness of the thin part is about 0.6 to 0.2.
It is desirable to set the thickness to 2 mm, and the thickness of the thick part is 2 mm
It is desirable to double or more.

Also, the width of the thick part is about 0.5 to 1. □mm, and the width of the thin portion is preferably about 0.1 to Q, 5mm.

As the deterioration accelerator, a known deterioration accelerator or embrittlement accelerator for synthetic resins can be used.

For example, copper or iron salts such as copper chloride, iron chloride, copper stearate, copper oleate, iron oleate, unsaturated salts such as propylene diamine oleate, oleic acid derivatives, linoleic acid derivatives, sorbitan monooleate. compounds, polyethers such as polyethylene glycol, polyoxyethylene oleate, polyoxyethylene nonylphenol ether, polyoxyethylene nonylphenyether, polyoxyethylene alkylamide, polypropylene glycol, sodium dodecylbenzenesulfonate, alkylsulfonic acid Sulfonic acid salts such as soda, organic halogen compounds such as chlorinated polypropylene, chlorosulfonated polyethylene, etc. can be used.

This deterioration accelerator is 0.5
It is preferable to use it in a proportion of from 5% by weight.

As the olefin resin, polypropylene, polyethylene, or a mixture thereof with a small amount of other resin can be used.

As the polyethylene, both high density polyethylene and low density polyethylene can be used.

Furthermore, copolymers of ethylene and propylene or mixtures thereof can also be used.

To foam olefin resin, put the olefin resin into an extruder, heat the resin in the extruder, and melt it.
A blowing agent is kneaded into this and the mixture is extruded and foamed at the same time.

As the blowing agent, it is possible to use aliphatic hydrocarbons or halogenated aliphatic hydrocarbons having a boiling point lower than the softening point of the olefin resin, or a solid compound that decomposes at the softening point of the olefin resin to generate gas. can.

Examples of the former are propane, butane, methyl chloride, etc., and examples of the latter are azosica-bonamide, dinitrosopentamethylenetetramine, etc.

The degree of foaming is preferably set to a foaming ratio of 1 to 3 times.

In order to make the string according to this invention, it is desirable to use extrusion molding.

That is, first, a deterioration accelerator is mixed into an olefin resin, this is put into an extruder, and it is thoroughly kneaded with a foaming agent in the extruder, so that when extruding from a die, thick parts and thin parts are formed alternately. It is desirable to do so.

Further, it is desirable to stretch the extrusion molded product at an appropriate temperature to form a string.

Further, similar thick portions and thin portions may be provided along the longitudinal direction of the string.

Note that the width of the string is preferably 6 to 25 mm.

Since the string of this invention is entirely made of a foamed olefin resin containing a deterioration accelerator, the olefin resin is susceptible to deterioration due to the deterioration accelerator and the foamed structure.

However, when using this string, the olefin resin has not deteriorated, so it can be used like a normal string.

While being used as a string, the olefin resin deteriorates due to exposure to sunlight, and the thinner parts first become brittle and are destroyed, leaving only the thicker parts separated.

Once the thick part is separated, the string no longer retains its original strength and becomes more susceptible to breakage.

Therefore, it is suitable for use as the above-mentioned wood-raised paper.

In addition, when the thin part is cut and the thick part is separated as mentioned above, the surface area of the thick part increases, which accelerates deterioration and makes it easier to decompose. It can be widely used as a cord for commercial use or forestry.

Here, a specific example of the rapid deterioration of this device will be explained as follows.

Polypropylene with 0.8% photodegradation accelerator (benzophenone) and 0.26% blowing agent (azocica-bonamide)
In addition, when the cross section is a rectangular string, the cross-sectional shape is made as shown in Figure 2 using a material with the same composition as A. Comparison with B (thick part Q, 5 mm, thin part Q, 3 mm) In the former case, the number of days until the string broke was 216 days (with a variation of 76), but in the latter case, it was 152 days (with a variation of 38 days).
) (n = 30).

This confirmed the superiority of this device.

[Brief explanation of the drawing]

1 and 2 are partially cutaway perspective views of the string according to this invention. In the figure, 1 and 3 are thick parts, and 2 and 4 are thin parts.

Claims (1)

[Scope of utility model registration request] In a string-like article made of an olefin resin foam containing a deterioration accelerator and formed into a long belt-like body, the cross-sectional shape is formed into a bead shape, and a thick part and a thin part are separated. An agricultural or forestry cord made of alternating layers.