JPH038167B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a novel soil conditioner for agriculture and horticulture.

As is well known, in order for plants to grow well,
It is necessary that the growing soil has appropriate pores, good air permeability, and good water retention. For this reason, rice straw, rice husks, etc. have been poured into the soil for a long time to keep the soil pore volume at an appropriate level and improve the physical properties of the soil. However, with recent cropping regulations, rice straw, etc., has become in short supply, and it has become increasingly difficult for people other than rice farmers to obtain rice straw, etc.

In view of such circumstances, the present inventor focused on the use of synthetic resin foam as a soil conditioner,
Although various studies were conducted, the results were not easily achieved. In other words, in order to be suitable for use as a soil conditioner, it is necessary to meet certain conditions such as having adequate water retention, being easily degradable, being able to mix uniformly with the soil, and having adequate heat retention. Yes, but
Conventional general synthetic resin foams have advantages and disadvantages, and it has been difficult to find one that satisfies all of these conditions. However, as a result of continuing research without giving up, we finally discovered that foams containing 1,2-polybutadiene as a main component satisfy all of the above conditions and can be used extremely favorably as soil conditioners. I have completed my invention.

That is, the present invention is characterized in that it consists of a crushed product of a foam whose main component is 1,2-polybutadiene blended with superabsorbent resin powder.

This foam is made by blending a small amount of super absorbent resin powder into a polymer blend of thermoplastic resin containing a photosensitizer and a thermally decomposable blowing agent, and irradiating it with ultraviolet rays of a predetermined wavelength and intensity for a short period of time. It is produced continuously by cross-linking into a three-dimensional network and then heating it above the decomposition temperature of the blowing agent to expand the foam, and those with a foaming ratio of about 10 to 20 times are preferably used. Ru. The main component, 1,2-polybutadiene, has good thermal stability and moldability, has a relatively large number of 1,2 bonds at 70% or more, a relatively high molecular weight of 100,000 or more, and a crystallinity of 50% or less. Those that have a relatively low degree of syndiotactic stereoregularity of 20% or more (for example, the product name manufactured by Japan Synthetic Rubber Co., Ltd.)
RB810 etc.) are used.

As the highly water-absorbent resin powder blended into the 1,2-polybutadiene foam, for example, acrylic acid/vinyl alcohol copolymer, sodium acrylate polymer, sodium acrylate/acrylamide copolymer, etc. are preferably used. Ru. The amount of super absorbent resin powder blended is preferably about 1 to 2% by weight based on the crushed 1,2-polybutadiene foam. This is because if it is less than 1% by weight, the improvement in water retention will not be so significant, and if it exceeds 2% by weight, the water retention will be excessive and root rot will occur.

General foams other than this 1,2-polybutadiene foam, such as polyethylene and polystyrene foams, are usually extremely lightweight with an expansion ratio of about 30 to 50 times, so they float on the soil surface. It has the disadvantage that it is difficult to mix uniformly and is scattered by the wind, and it is difficult to decompose, so it remains in the soil for how long, and it is hydrophobic, so it has the disadvantage of decreasing water capacity. It is unsuitable as a modifier. On the other hand, polyurethane foam is more suitable than polyethylene or polystyrene foam in that it is easily degradable and hydrophilic, but it has too much water-holding ability, so if it is mixed with soil, it may cause waterlogging. It has the disadvantage of causing root rot in plants, and like polystyrene foam, it has a high expansion ratio of about 50 times, so it has the disadvantage of being difficult to mix uniformly with the soil, making it unsuitable as a soil conditioner. It is.

On the other hand, the 1,2-polybutadiene foam blended with the superabsorbent resin powder has high photodegradability and can be easily decomposed and turned into soil within a short period of time. The semi-hydrophilic and blended super absorbent resin powder ensures an appropriate amount of water retention, and the foaming ratio is less than half that of the foams mentioned above, such as polyethylene, polystyrene, and polyurethane. It satisfies all of the above-mentioned conditions, such as uniformly mixing with the soil without floating up and also having appropriate heat retention properties, making it an extremely suitable soil conditioner. In particular, as mentioned above, those with a foaming ratio of 10 to 20 times are extremely desirable since they have good water retention, uniformity, and the like.

The soil conditioner of the present invention is made of a crushed 1,2-polybutadiene foam blended with such a superabsorbent resin powder, and there is no particular restriction on the size of the crushed material, but Approximately 10μm
It is desirable that the crushed material be of irregular shape and have a size within the range of about 2 cm. If it is smaller than 10μm, little effect on increasing soil pores can be expected;
This is because if it is larger than 2 cm, problems such as difficulty in uniformly mixing it with the soil will occur. The above-mentioned 1,2-polybutadiene foam has a satisfactory soil improvement effect by itself, but by blending a small amount of super absorbent resin powder as in the present invention, the water retention property can be moderately increased. It becomes a soil conditioner with even better effects.

Further, the soil conditioner of the present invention may further contain fertilizers such as nitrogen, phosphoric acid, potassium, etc., if necessary.

The soil conditioner of the present invention as described above is mixed with the soil at a ratio of 10 to 90% (vo 1%). Ten
If it is less than 90%, the effect of the soil conditioner is not significant.
This is because if the amount exceeds this amount, the amount of soil will become too small, which will actually worsen the growth of plants. Although the figure of 90% may seem too high at first glance, this 1,2-polybutadiene foam is highly flexible,
Since the volume easily contracts due to earth pressure, the amount of soil pores will not become excessive.

Next, an example will be given and explained.

Example: 30 pieces of crushed 1,2-polybutadiene foam (irregular crushed pieces with an average size of 10 mm)
%, 50%, and 80% (VO 1%) mixed three types of test soil were filled into three planters (inner volume 1500 c.c.), and Primula polyanthus seeds were planted and allowed to grow under the same conditions. Their developmental status was observed.

For comparison, the same amount of soil without 1,2-polybutadiene foam was filled in a planter and a similar growth test was conducted.

As a result, the products filled with crushed 1,2-polybutadiene foam showed better growth in terms of root development, leaf color, flower size, and number of blooms than those without the foam. The growth was particularly good with the 50% combination.

After that, we stopped the water absorption and investigated the length of time it takes for the Plum Lapolianthus to wilt.The results showed that the one with no foam wilted the fastest, followed by the one with 30%, and the second one with 50%. Of these, the one that lasted the longest was the one containing 80%.

Next, 30% of crushed 1,2-polybutadiene foam mixed with super absorbent resin powder,
Three different test soils mixed at 50% and 80% (VO1%) were filled into three planters (inner volume 1500 c.c.), and Primula polyanthus seeds were similarly planted and allowed to grow under the same conditions. When we observed the state of growth, we found that those packed with crushed 1,2-polybutadiene foam mixed with super absorbent resin powder were different from those filled with crushed pieces of 1,2-polybutadiene foam alone. Furthermore, the growth was better in terms of root development, leaf color, flower size, and number of flowers.

In addition, when we investigated the length of time until water absorption was stopped and Primula polyanthus withered, we found that 1,2-
It takes longer to wilt than one filled with crushed polybutadiene foam alone, and the blending ratio is also lower.
The one with 30% formulation was followed by the one with 50% formulation, and the one with 80% formulation lasted the longest.

As can be understood from the above description and examples,
The soil conditioner of the present invention is useful because it can improve soil to make it suitable for plant growth and improve plant growth.

Claims (1)

[Claims] 1. A soil conditioner for agriculture and horticulture, characterized by comprising a crushed product of a foam mainly composed of 1,2-polybutadiene and blended with super absorbent resin powder.