JPH104800A - Coating materials for agricultural facilities - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To provide a covering material for an agricultural facility that has high strength, high light-shielding properties, light weight, and easy handling. SOLUTION: On one or both surfaces of a woven fabric 1 made of polyethylene flat yarn, a surface layer 2 made of a thermoplastic synthetic resin blended with a black pigment for imparting light-shielding property is provided in the thermoplastic synthetic resin. The system pigment is one of the surface film 2
A coating material for an agricultural facility, which is applied so as to be uniformly dispersed in a range of about 1.75 to 2.05 g per square meter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a covering material for an agricultural facility which covers the ceiling or wall of an agricultural facility such as a greenhouse or a pipe house from outside or inside thereof.

[0002]

2. Description of the Related Art In conventional covering materials for agricultural facilities, light-shielding sheets characterized by light-shielding properties are roughly classified into two types. One is for the purpose of creating an optimal growth and good growth environment for crops such as houseplants and soft vegetables. These materials have a high light-shielding property, and various materials have been devised by various material manufacturers to provide a wide variety of materials.

[0003] Among the above-mentioned materials, the former is a film obtained by kneading aluminum powder into a thermoplastic resin such as a polyvinyl chloride resin or the above-mentioned thermoplastic synthetic resin film by subjecting it to aluminum vapor deposition or the like. Various types of fibrous materials, such as sheet-like materials having a light-shielding property, or Russell netting, Karami fabric, cold gauze, split-fiber nonwoven fabric, etc., are introduced. Multi-layer consisting of a material with an inner layer or a relatively thick film of about 100μ laminated with a large amount of black pigment mixed in a thermoplastic synthetic resin such as polyvinyl chloride resin or polyethylene resin. A light shielding sheet having a structure is introduced.

[0004]

However, the latter,
That is, a light-shielding sheet using an aluminum foil or a multilayer structure in which a black pigment is kneaded performs a sufficient function in terms of light-shielding properties. However, it is very inconvenient to handle because of its large thickness and heavy weight per unit area, and it is expensive in terms of price. Therefore, it has been desired to provide a coating material for agricultural facilities which is excellent in durability, thin, lightweight, and easy to handle without losing a high light-shielding property.

The present invention has been made in view of the above situation, and has as its object to provide a coating material for agricultural facilities which has high light-shielding properties, is lightweight, and is easy to handle, in addition to having high strength.

[0006]

Means for Solving the Problems A coating material for an agricultural facility according to the present invention which has been made to solve the above-mentioned problems is a black-based material for imparting a light-shielding property to one or both sides of a woven fabric made of polyethylene flat yarn. A surface layer made of a thermoplastic synthetic resin containing a pigment is coated with the black pigment in the thermoplastic synthetic resin in an amount of about 1.7 per square meter of the surface layer.
It is characterized in that it is applied so as to be evenly distributed in the range of 5 to 2.05 g. The surface film has a density of 0.930 g.
Preferably, the main component is a polyethylene-based resin composition of not less than / 45 cm3 and not more than 0.945 g / cubic centimeter.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the covering material for agricultural facilities according to the present invention will be described below in detail with reference to the drawings. The coating material for agricultural facilities according to the present invention includes a surface film 2-a fabric 1
Or, a two-layer structure of a nonwoven fabric layer (see FIG. 1), a surface film 2-a fabric 1 or a nonwoven fabric layer-a three-layer structure of a surface film 2 (see FIG. 2), a surface film 2-a fabric 1 or a nonwoven fabric layer- Four or more layers including a low-density polyethylene layer 4-aluminum-deposited layer 6-surface film 2 are exemplified.

[0008] The resin composition of the surface film 2 to be adhered to a woven or non-woven fabric basically has a density (JIS K-711).
2): 0.930 g / cubic centimeter or more and 0.94
Although a polyethylene resin of 5 g / cubic centimeter or less is used, it is preferably 0.934 g / cubic centimeter to 0.942 g / cubic centimeter in terms of abrasion resistance and extrusion processability, and a melt flow rate (JIS K-7210). 4) to 20 g /
10 min is desirable.

The surface layer 2 made of a polyethylene resin composition having a density of less than 0.930 g / cubic centimeter as a raw material resin has poor abrasion resistance and slipperiness. In addition to the problem that the light-shielding property is remarkably reduced, the workability at the time of hoisting / unwinding work cannot be overlooked.
The raw material resin of the polyethylene-based resin composition exceeding 0.945 g / cubic centimeter not only has poor workability but also has a problem that the formed surface layer 2 makes the sheet stiff and the spread workability deteriorate. This is because it occurs. That is, by using the polyethylene-based resin composition having the density in the specific range, excellent workability can be obtained and light-shielding property for a long period can be secured.

Examples of the type of black pigment to be added to the material resin of the surface layer film 2 include thermal black, furnace black, channel black, aniline black and the like. Furnace black is more desirable in terms of extrusion stability, pigment dispersibility, and good workability of color removal after processing. The finer the particle size of these carbon blacks, the higher the contact force and the concealing property are secured, but from the viewpoint of cost, the specific surface area is about 50 square meters / g or more, preferably about 80 square meters / g or more. .

The water content of the black pigment is at least 1
It is necessary to be below 000 ppm. If the content is 1000 ppm or more, the moisture contained in the black pigment is volatilized by heat during the melt extrusion lamination processing, and the pinhole phenomenon caused by foaming causes poor light-shielding properties. As for the lower limit of the water content in the black pigment, the smaller the lower, the better, but the higher the drying degree, the higher the cost. Therefore, if the lower limit in consideration of the economy at the present stage is given, about 100 ppm would be appropriate.

When the thickness of the layer is 30 μm, the final amount of the black pigment required to obtain high light-shielding properties is about 6.7% by weight. A predetermined light-shielding property can be obtained even when the concentration is low in proportion to
In the case of 0 μm, a sufficiently high light-shielding property can be obtained even when the final concentration is about 2.0% by weight. As described above, the amount of the black pigment to be added varies depending on the thickness of the layer to be added, but from the absolute amount of the black pigment, from 1.75 g to 2.05 per square meter of the surface layer film.
The amount of about g needs to be mixed almost evenly. Therefore, when the surface film 2 is applied to both surfaces of the fabric 1, about half the amount of each of the surface films 2 may be mixed. In the case of such a structure, a black pigment is blended in one of the surface layers 2 and a pigment having a high light-reflecting color tone such as silver, other than the black pigment, is applied to the other surface layer. May be added to increase the pigment content, and a black pigment may not be added for the purpose of reducing the pigment cost.

The black pigment may be compounded by dry blending the black pigment directly with the material resin of the surface layer film 2 or by using a so-called masterbatch which is previously kneaded with a thermoplastic synthetic resin and pelletized. It may be performed by a widely used technique such as dry blending.
Further, if necessary for the resin composition of the surface layer film 2, an antifogging agent, an antistatic agent, a fungicide, an anti-algal agent and the like may be added. It may be kneaded in advance with the raw material resin, or may be dry-blended immediately before processing.

Among the above-mentioned additives, the method for adding an anti-fogging agent which plays an important role in the prevention of dripping of water droplets on leaves and the prevention of diseases in the coating material for agricultural facilities of the present invention is described. Means for kneading the antifogging agent or means for applying. Since the antifogging agent has a property of easily absorbing water even when the antifogging agent is used in the masterbatch of the resin composition, a sufficient drying treatment is performed on the antifogging agent masterbatch. It is desirable to do.

When the surface layer 2 made of the polyethylene resin composition is applied, a melt extruder is used to apply 280 to 3
Extrusion lamination of the resin composition heated and melted at 20 ° C. is employed. Although the thickness of the surface films 2 and 2 may be different for each surface of the sheet, the thickness of the surface film 2 may be 30
The standard is set to be not less than μm and not more than 100 μm, and is usually set to be not less than 30 μm and not more than 60 μm, which is excellent in terms of balance between rigidity and workability. The reason is that, at present, the blending amount per unit area of the black pigment, which is the minimum necessary for obtaining high light-shielding properties, is almost fixed. As a result, not only the pinholes are easily generated but also the heat sealing strength tends to be weakened. In that respect, if the thickness of the surface layer film 2 is less than 30 μm, it is not convenient. On the other hand, if it exceeds 100 μm, the proportion of the black pigment in the entire film becomes low, and pinholes are unlikely to occur. However, there is a problem that the sheet becomes stiff and heavy, resulting in poor workability. The range of the film thickness is balanced from these viewpoints.

The woven fabric 1 to which the surface layer film 2 is applied is a single layer flat yarn or a multilayer flat yarn having a length of 4 to 50 yarns / inch and a width of 4 to 50 yarns / inch. . The weave shape may be appropriately selected from plain weave, twill weave, oblique weave, double weave, and the like, and in the case of plain weave, a yarn perpendicular to the winding direction to improve convergence during winding. The multilayer flat yarn made of a thermoplastic resin other than the polyethylene resin composition is driven as the warp or the weft of the woven fabric 1 within a range in which the number of the woven fabrics is slightly reduced or the adhesiveness between the woven fabric 1 and the surface film 2 is not impaired. But it is good. Further, in place of the woven fabric 1, a nonwoven fabric formed by aligning the warp and the weft without being woven and bonding the intersections may be used.

As the raw resin for the single-layer flat yarn, for example, a polyethylene-based resin composition having good adhesiveness to the surface layer film 2 to be laminated is desirable. The density is 0.93
The standard value is 0 to 0.970 g / cubic centimeter, but usually 0.950 to 0.9
Use around 60 g / cubic centimeter.
The range of the melt flow rate suitable for use as a material is around 0.3 to 1.5 g / 10 min.

It is desirable to use a polyethylene resin having good adhesiveness to the surface layer film 2 to be laminated, even if it is a raw material resin for the outer layer of the multilayer flat yarn. The melting point is about 90 to 125 ° C., but usually a melting point of 105 to 115 ° C. is selected from the viewpoint of workability and strength. The appropriate range of the melt flow rate in this case is 1.0 to
It is around 10 g / 10 min. On the other hand, for the inner layer resin of the multilayer flat yarn, for example, a polyethylene resin composition having a higher melting point than the outer layer resin whose melting point is about 130 to 140 ° C. is used. Usually, 130 to 136 ° C. is used in consideration of workability and strength. The appropriate range of the melt flow rate in this case is 0.3 to 1.5 g / 1.
It is near 0 min.

In addition, a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, a flame retardant, a filler, and the like are added to the outer layer and the inner layer resin of the single layer flat yarn and the multilayer flat yarn as required. In some cases.

The flat yarn used for weaving the woven fabric 1 is as follows:
Both the single-layer flat yarn and the multi-layer flat yarn have denier: 50 to 2000 d, width: 0.5 to 6.0 mm, and yarn thickness: 10 to 40 μm, but denier: 200 to 1500 d is usually used. , Width 1.0 ~
3.0 mm, and the thickness of the yarn is in the range of 15 to 30 μm. The multilayer flat yarn mainly has a three-layer structure of outer layer: inner layer: outer layer, and its thickness ratio is such that one outer layer has a ratio of 10 to 25% and the inner layer has a thickness of 80 to 50%.
The form of the flat yarn may be a split yarn or a streaked yarn.

[0021]

EXAMPLES Various base fabrics were manufactured as samples from the above-mentioned materials and other materials, and some samples were extracted to produce trial coating materials for agricultural facilities according to the present invention. In addition to the details of the manufacturing method, the specifications of each sample (see Table 1) and the characteristics of each sample such as surface slipperiness, sheet surface scratchability, stiffness, light-shielding properties, pinhole occurrence status, etc. (See Tables 2 and 3).

The sample shown in each table is a laminated sheet 3 having a multilayer structure composed of a surface film 2-a fabric 1 and a surface film 2, and only one of the surface films 2 and 2 made of a polyethylene resin composition has a black color. Pigment is blended.

The single-layer flat yarn constituting the base fabric 1 of the present embodiment is a low-pressure high-density polyethylene manufactured by Mitsubishi Chemical Corporation (density: 0.952 g / cubic centimeter, melt flow rate: 0.6 g / 10 min). ) 10
0 parts by weight, 0.1 part by weight of a hindered amine-based light stabilizer was added, and the mixture was kneaded sufficiently and extruded from a round die using a melt extruder, and formed into a film by inflation. After cutting on the same line with leather (razor) to width 3.0mm,
It is stretched 7 times in the take-off direction at a temperature of 110 ° C. on a hot plate, and then subjected to a 6% relaxation heat treatment at a temperature of 115 ° C. on another hot plate. Denier: 300 d, yarn width:
1.4 mm, strength: 5.2 g / d, elongation: 35.0%
This is a uniaxially stretched product. This single-layer flat yarn is sewn on a sulzer loom in a length direction of 17 yarns / inch and in a width direction of 17
A plain weave fabric 1 was formed by weaving in a grid pattern at books / inch.

On one side of the woven fabric 1, the thickness of the resin composition obtained by adding 100 parts by weight of a high-pressure low-density polyethylene resin composition and 0.2 part by weight of a hindered amine-based light stabilizer and sufficiently kneading the mixture. A 30 μm surface film 2 is formed by melt extrusion lamination, and the other surface is coated with a surface film 2 made of a polyethylene resin composition containing a black pigment as described above by melt extrusion lamination. By forming, samples having different specifications as shown in Table 1 were obtained.

[0025]

[Table 1]

[0026]

[Table 2]

[0027]

[Table 3]

[0028]

[Table 4]

The measurement of the slipperiness was performed as shown in FIG.
A sample 12 was laid on the sample 12 and the sample 12 was stuck to the entire lower surface of the sample 12. A weight W of 243 g / 30 cm 2 was attached to the side by a steel wire 15 fixed to the side.
It is performed by pulling horizontally at a speed of 00 mm / min. The coefficient of static friction is derived from μs = Fs / W by measuring the tensile force Fs when the weight 14 starts to move. The coefficient of kinetic friction is derived from μk = Fk / W by measuring the pulling force Fk when the weight 14 slides on the sample 12.

FIG. 4 shows the test for the scratch property of the sheet surface.
One end of a band 8 imitating a holding string of a pipe house is fixed to an upright wall surface 9 and is rotatably supported at a distance from the wall surface 9 with a horizontal axis at about 80 ° C.
This is performed by using a device in which a weight 10 of 500 g is hung on the other end of the band 8 by hanging it over a heat roll 11 heated to a temperature. In the test, the degree of wear after the sample was applied to the peripheral surface of the heat roll 11 and rotated at 10 m / min for 1 hour was evaluated as follows: ：: no change, Δ: fine scratches less than 10 X: Evaluation was made at three stages of occurrence of scratches on the entire surface.

The rigidity is measured by a 45-degree cantilever method using a table 17 having a 45-degree inclined surface 16 and a smooth surface as shown in FIG. 6 (JIS L-1096 (1990)).
Perform with. That is, five test pieces of about 2 × 15 cm were taken from each sample in the vertical and horizontal directions, respectively.
The short piece 18 of the sample is aligned with the baseline 19 of the scale 20 on the scale, and the short piece 18 is gently slid in the direction of the inclined surface 16 by an appropriate method so that one end of the short piece 18 contacts the inclined surface 16 at the other end. The position is read on a scale 20. As a result, the stiffness is represented by the length (mm) to which the short piece 18 has been moved, each of which is measured on the front and back of five pieces, and is represented by the average value in the vertical and horizontal directions.

The light-shielding properties were determined by making a round simple pipe house whose entire surface was covered with a sample and visually observing the direction of the sun from inside the pipe house. A: completely invisible, B: blurry sun, C: clear And the sun are visible, D: the whole surface looks faint, and E: the entire surface is bright.

Regarding the occurrence of pinholes, O
This is performed using an HP projector. That is, a sample is placed on the light projector, and light leakage is visually observed.

Table 4 shows the evaluation results of the spreading workability, the winding workability, and the durability of the surface layer film 2 with respect to various curtains extracted from each sample and experimentally manufactured. Regarding the workability of stretching and winding, the width of each sample was cut by hot air heat sealing to produce a lining curtain for a greenhouse for greenhouse use. The lining house curtain was arranged, and the work of extending and winding the lining house curtain was actually evaluated.
Regarding the durability of the surface layer film 2, the repetition of the spreading operation and the winding operation in the facility horticultural house is continuously performed over a long period of time, and a decrease in light-shielding property due to the repetition is indicated as a service life. Was.

In consideration of these, the density of the resin composition constituting the surface layer film 2 must be 0.927 g / cubic centimeter or more in order to obtain the scratch property of the sheet surface. Sample no. 17 indicates the lower limit. Then, it can be seen that approximately the same density is required for obtaining the surface slipperiness. In addition, in the case of the stiffness, although it depends on the film thickness, it can be said that the sample 21 is too stiff in obtaining the surface layer 2 of 40 μm. In order to obtain an evaluation A in terms of light-shielding properties, the sample no. 4 is the lower limit, and in terms of pinhole generation, the moisture content of Sample 11 is as follows:
1000 ppm is the upper limit.

From Table 4, the workability of spreading, the workability of winding and the durability of the surface film 2 were evaluated.
2 and prototype no. 3 used in sample no. 18 and sample n
o. In addition to the favorable results obtained with the sample no. 17 to no. 20 is a suitable sample, and the conditions described above for the surface layer 2 made of polyethylene resin, ie, the density of the polyethylene resin, the amount of the pigment mixed into the main material of the surface layer 2, the water content of the pigment, the surface layer The result confirms the appropriate value of the thickness of the film 2.

[0037]

As described above, by using the covering material for an agricultural facility according to the present invention, not only high strength is provided, but also
Despite its thinness and light weight, it is easy to handle, but by having both high light-shielding properties and durability, it not only has a remarkable effect in night-time cooling of strawberry cultivation or short-day treatment of chrysanthemums, etc. This greatly contributes to reducing the burden.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of a covering material for an agricultural facility according to the present invention.

FIG. 2 is a sectional view showing an example of a covering material for an agricultural facility according to the present invention.

FIG. 3 is a cross-sectional view illustrating an example of a covering material for an agricultural facility according to the present invention.

FIG. 4 is a side view of a test device for measuring a scratch property of a sheet surface.

FIG. 5 is a perspective view of an apparatus for measuring slip properties.

FIG. 6 is a perspective view of an apparatus for measuring rigidity.

[Explanation of symbols]

 1 Textile 2 Surface film

Claims (2)

[Claims] 1. A surface layer (2) made of a thermoplastic synthetic resin in which a black pigment is blended on one or both sides of a woven fabric (1) made of polyethylene flat yarn to provide light-shielding properties, is formed by thermoplastic synthesis. The black pigment in the resin,
Surface layer (2) About 1.75 to 2.0 per square meter
A coating material for agricultural facilities, which is applied so as to be evenly dispersed in a range of 5 g. 2. The surface layer (2) has a density of 0.930.
The coating material for agricultural facilities according to claim 1, characterized in that the main material is a polyethylene resin composition of not less than g / cubic centimeter and not more than 0.945 g / cubic centimeter.