JP2022069022A - Coating sheet for tea trees - Google Patents

Abstract

To provide a coating sheet for tea trees that holds a necessary light blocking rate while suppressing a rise in sheet temperature, selectively blocks light with a wavelength in the ultraviolet light region, and improves the airflow to tea trees in a shelf facility or under directly-coating materials, thereby improving the growth environment of the tea trees.SOLUTION: A coating sheet for tea trees is a sheet formed from the combination of warp 21 as a white reflection tape and weft 31 as a black dye material. The white reflection tape contains a large number of one or more kinds of fillers, containing at least one kind of white pigment. Both sides of the warp 21 have a large number of projections formed by the fillers and voids therearound, the projections resulting from the process of stretching an olefinic resin film into a thin film. The warp are arranged side by side without gaps and weaved with the weft.SELECTED DRAWING: Figure 1

Description

The present invention mainly relates to a sheet that covers a tea plant when cultivating a tea plant for producing green tea.

By cover cultivation, which is cultivated in a shaded state for a certain period of time, the tea leaves have a coarse and soft distribution of veins, a thin leaf thickness, and an increase in chlorophyll makes the tea leaves dark green. In addition, since it has the effect of preventing theanine, which is an umami component, from changing to catechin, cover cultivation has long been used as a cultivation method for high-grade tea having a large amount of umami component.

As a traditional covering cultivation method, there is a shelving covering with a bamboo blind coating. For this bamboo blind covering, a covering shelf with a height of about 2 meters is provided in the tea plantation, and when one or two new leaves are opened, the entire tea plantation is covered with a shading rate of about 60%. It is a coating method that maintains for about 10 days, and then sprinkles rice straw on the bamboo blinds so that the shading rate is 95 to 98% as a whole and maintains for about 10 days.

The tea leaves cultivated by the shelving coating with the bamboo blind coating are made into gyokuro, which is a high-grade tea through a kneading process from steaming heat, or are made into green tea without kneading and then ground with a stone mill to make matcha.

Since such a bamboo blind coating requires a great deal of labor and skill and is costly, as an alternative, a shelf-mounted coating (hereinafter referred to as "blackened fiber") is used to perform a two-stage coating (hereinafter referred to as "blackened fiber"). Hereinafter, "blackened fiber shelving coating") has been developed, and most of the shelving coatings have recently become blackened fiber shelving coatings. In the blackened fiber shelf covering, when one new leaf is opened, a net of blackened fiber with a shading rate of about 70% is spread on the upper and side surfaces and maintained for 7 to 10 days, and then the shading rate is about 90% in the lower row. This is a coating method in which the net is stretched and double-coated to maintain a light-shielding rate of 95 to 98% for about 2 weeks.

On the other hand, there is a direct covering method as a covering method other than the shelf covering method. The direct coating method is a coating method in which the coating material is directly applied to the tea plant. As for the shelf-mounted coating method, the direct-mounted coating method is increasingly being adopted as a simpler and lower-cost coating method because the installation cost of the shelves is high even if the blackened fiber shelf-mounted coating is used. Although the tea leaves cultivated by direct covering are inferior to the shelving covering, they are superior in quality such as vivid color and taste with a lot of umami components as compared with ordinary open-field sencha. For this reason, in addition to being used as high-grade sencha, it is also used as matcha in a broad sense that has been made into green tea and then crushed with a ball mill. In particular, the demand for matcha in a broad sense, including exports, for food products has increased sharply in recent years.

In the direct coating method, blackened fibers with a light-shielding rate of about 60 to 90% are used in consideration of the quality based on the application of the product, and the tea plant is directly covered from the time when about two new leaves are opened. It is a coating method that is maintained for 2 to 3 weeks.
As a simplified version of the shelving covering method, there is also a tunnel covering that covers the tea plant without contacting the tunnel shape.

By the way, the blackened fiber, which is mainly used as a light-shielding material in both the shelf-mounted coating and the direct-mounted coating, exerts the effect of blocking the light irradiation of the tea plant in the shelf facility or under the direct-mounted material by its light absorbing action. On the other hand, since the temperature of the blackened fiber itself rises due to the light absorption action, the temperature rises for the tea plant in the shelf facility or under the direct hanging material. As the demand for high-grade tea increases and the production of tea in the covering facility in the summer is increasing, it is indispensable to take measures against heat to support the production of the covering tea in the shelf facility. Further, in the case of the direct coating, the heat absorbed by the blackened fibers is directly transmitted to the tea plant, so that the adverse effect is larger and the leaves are burnt. Therefore, there is a demand for a covering material having a heat-shielding property superior to that of the blackened fiber while ensuring a light-shielding property equivalent to that of the blackened fiber.

In addition, in the case of shelving coating, blackened fiber shelving coating has been almost replaced by blackened fiber shelving coating due to the reduction of skill and labor, but in terms of quality, blackened fiber shelving coating is evaluated to be inferior to this bamboo blind coating. There is. It has been pointed out that the cause of this is not a mere shading rate but a difference in the shading rate in the ultraviolet light region. For example, "The effect of spectral spectral characteristics in the blind coating and the effect of UV irradiation and removal on the quality of tea shoots (Tea Industry Research Report No. 116, published in December 2013) shows that in the case of the blind coating, the ultraviolet light region On the other hand, in order to produce high-grade tea equivalent to the bamboo blind coating, while pointing out that the blackened fiber shelving coating does not have such selective shading while selectively having a high shading rate. Describes that a material that has selective ultraviolet light shielding properties such as a bamboo blind coating and is easy to handle is required.

In addition, the covering material has to have a very low aperture ratio of the sheet in order to secure the light-shielding property, and therefore, there is almost no ventilation in the shelf facility or under the direct hanging material. Therefore, as described above, the hot air brought to the tea plant in the shelf facility or under the direct hanging material tends to be trapped as it is, which causes leaf burning. Especially in the case of direct application, the temperature of the tea plant surface tends to rise and the risk of leaf burning is greater.

There is also the effect of chills. Many tea-producing areas have frost-proof fans installed to prevent frost damage, but the relatively high-temperature air in the sky that circulates is blocked by the covering material and does not reach the tea plants inside the shelf facilities or under the direct-hanging materials. Therefore, the effect of the frost-proof fan cannot be obtained. In particular, direct coating has high heat transfer efficiency and promotes radiative cooling, which is a major cause of leaf burning due to frost damage.
From the above, a covering material having ventilation is required.

As a light-shielding sheet, there is a proposal of a technique of laminating a reflective layer by thin-film aluminum deposition on the surface (Patent Documents 1 and 2). Although the solar reflection effect of the thin-film vapor-deposited aluminum layer is very high, the technique according to Patent Document 1 has a problem that the light-shielding effect is rather reduced because the reflection in the downward direction of the covering sheet also occurs. Further, the technique according to Patent Document 2 overcomes the problems like the technique according to Patent Document 1, but when used as a weft of a covering sheet, the reflective layer becomes an upper surface or a lower surface due to twisting during weaving. As a result, there is a problem that the effect of reflecting sunlight cannot be sufficiently exerted.

Further, there is a proposal of a technique relating to a tape in which a large number of uneven shapes are generated on both surfaces by stretching a film containing a filler inside (Patent Document 3). However, the present invention aims to promote the growth of plants by irradiating the area above the tape with diffusely reflected light widely, and to confuse flying pests by irradiating diffusely reflected light in the ultraviolet region. It is supposed to be. On the other hand, the present invention aims to act downward on the tape in the direction opposite to that of the above invention, and is intended for a problem in a limited field of high quality tea plant cultivation. Further, regarding the composition, the above invention merely positions the filler as a substance for causing diffuse reflection on the surface and inside, and does not make the existence of the filler as a white pigment a constituent requirement. Further, there is no viewpoint of selectively blocking light by absorbing light in the ultraviolet light region. Therefore, the above invention is different from the present invention.

Jitsufuku No. 5-33339 Gazette Japanese Unexamined Patent Publication No. 2004-176210 Japanese Unexamined Patent Publication No. 2016-218449

An object of the present invention is to provide a coating sheet for tea plants that maintains a required light-shielding rate while suppressing an increase in sheet temperature. Another object of the present invention is to provide a coating sheet for tea plants that selectively blocks wavelengths in the ultraviolet light region. Furthermore, the purpose is to improve the growing environment of tea plants by improving the ventilation to the tea plants in the shelf facility or under the direct hanging material.

In order to solve the above problems, according to the present invention, a large number of fillers of one or more types containing at least one type of white pigment are contained therein, and an olefin resin film is stretched to thin the surface on both surfaces. It is a sheet formed by a combination of warp and weft, which is a white reflective tape having a large number of protrusions formed around the filler and voids formed around the filler, and weft, which is a black material, and the warp is gapped. Provided is a coating sheet for tea trees, which is characterized in that it is woven with the warp and weft in parallel.

In order to maintain the light-shielding property while improving the heat-shielding property, which is a problem of the conventional blackened fiber (black material for both warp and weft), in the present invention, the white reflective tape (warp and weft) juxtaposed without gaps in a plan view. Weaving is done by weaving a black material (warp and weft).

The warp threads can be juxtaposed without gaps in a plan view during weaving. Therefore, most of the sunlight irradiates the upper surface of the white reflective tape, and most of it is reflected upward by the white reflective tape. The heat shielding property can be exhibited without impairing the light blocking property.

However, even if the warp threads are juxtaposed without gaps, gaps or overlaps may occur between the warp threads due to weaving. Furthermore, it is inevitable that weaving will create a stereoscopic gap near the intersection of the warp and weft.

The role of the warp and weft is important in order to supplement the part where the light-shielding property is insufficient based on these and maintain the light-shielding property as a whole. Further, the wefts cannot be juxtaposed without gaps during weaving, and a certain amount of gaps are generated between the wefts. Therefore, it is preferable to determine the material and arrangement of the wefts in consideration of this point.

Comparing the light-shielding properties of white materials and black materials, white materials are mainly light-shielding properties based on reflection, and black pigmented materials are mainly light-shielding properties based on absorption, but in general, the total light-shielding property is black. The material of is higher. This is the reason why blackened fibers are generally used as a coating material for tea plants. If it is a black material, a part of the sunlight irradiating the gap between the black materials is absorbed by the side surface of the black material, which can contribute to the improvement of the light blocking effect. The same applies to the sunlight reflected on the surface of the white reflective tape. The high level of shading rate of the entire sheet is adjusted by selecting the material of the warp and weft and adjusting the density of the spacing between the warp and weft.

Contrary to the above configuration, when the warp is made of a black material and the weft is made of a white material such as white reflective tape, the light blocking rate is insufficient and the light blocking rate such that the sunlight shining on the gaps between the wefts cannot be blocked. It will not be possible to hold it. The same applies to the case where both the warp and weft are made of white material.

In the present invention, the material of the warp is a white reflective tape. If it is a tape, it is easy to juxtapose it without any gap including the overlap between the warps. When the warp yarns are monofilaments, the contact between the warp yarns adjacent to each other becomes a point contact, which is slippery and difficult to juxtapose without a gap.

In the present invention, the white reflective tape is a tape obtained by stretching an olefin resin film containing a large number of fillers inside, and the olefin resin flows by stretching to thin the film. The included filler has a higher specific gravity and higher rigidity than the olefin resin, does not follow the flow of the olefin resin as it is, and is not easily deformed. For this reason, voids (voids) are generated around the filler due to the difference in fluidity between the olefin resin and the filler, and the surface portion of the stretched tape on which the filler is located swells due to the fluidity due to stretching to form protrusions. It will be. The olefin resin has a small specific gravity (about 0.9) among synthetic resins and is excellent in injection fluidity.

The filler included in the olefin resin is a filler, which is mainly a powdery inorganic substance, but is not limited thereto. A pigment is a substance that is colored to a certain color, and is an opaque substance that does not act on a substance to be mixed and exhibits a predetermined color. The number of types of the above fillers is not particularly limited, and one type may be used or a plurality of types may be used. In the case of one type, the filler is always a white pigment. In the case of multiple types, in the case of all white pigments, in the case of one or more white pigments and pigments other than one or more white pigments, in the case of one or more white pigments and substances other than one or more white pigments, etc. There is.

The formation of protrusions on the surface of the reflective tape and the size of the protrusions are defined by the ratio of the particle size of the filler to the thickness of the stretched tape. When the particle size of the filler is constant, the thinner the tape, the larger the protrusion. The tape thickness is appropriately selected in consideration of factors such as the formation of protrusions and the strength of the tape.

If the filler is too small, voids are less likely to occur and protrusions on the surface are less likely to be formed. A filler (pigment) having an extremely small particle size makes the sheet transparent, the white color fades, and the ultraviolet light absorption decreases. On the other hand, if it is too large, uniform dispersion becomes difficult, film formation cannot be maintained, and a hole (fish eye) phenomenon occurs in the unstretched film. In the case of a plurality of fillers, if the functions to be exhibited differ depending on the type, the average particle size corresponding to each function is set. As described above, the particle size of the filler is set from various viewpoints, but the average particle size is preferably 2.5 to 6.0 μm from the viewpoint of forming surface protrusions.

The filler content is preferably 10% by weight or more in order to form protrusions, while the film is torn when the filler content is 40% by weight or more in the film state. The maximum is preferably 35% by weight because of the problem. The blending ratio of 10 to 35% by weight with respect to the olefin resin film means the weight ratio of the filler to the total weight of the olefin resin and the weight of the filler.

The void means a void. Further, "rigidity" refers to the ability of an object to withstand fracture against bending, twisting, etc., and represents the difficulty of deformation. Further, the "specific gravity" means an intrinsic specific gravity, for example, in the case of calcium carbonate, it is about 2.7, and in the case of titanium oxide, it is about 4.2.

The filler according to the present invention is kneaded into the film when producing an olefin resin film, or is contained inside the film by forming a filler-containing layer on the film surface by applying or attaching a material containing the filler. It will be. The kneading method is more preferable from the viewpoint of the simplicity of the manufacturing process and the effect of being contained substantially uniformly inside.

Further, there is provided a coating sheet for tea plants, characterized in that the tape width and the tape thickness of the white reflective tape are 20: 1 to 45: 1 in aspect ratio.

The white reflective tape contains the filler and is softened. Therefore, when it is used as a warp, it may be easily folded in the width direction during weaving. In order to prevent this, it is preferable that the tape width is a certain ratio or less with respect to the tape thickness. On the other hand, since the white reflective tape is characterized by forming protrusions due to thinning, it is preferable that the width of the stretched tape slit into a certain number of sheets is at least a certain ratio with respect to the tape thickness. To meet these different requirements, the tape width and tape thickness of the white reflective tape are preferably 20: 1 to 45: 1 in aspect ratio. From the viewpoint of improving ventilation, which is one of the objects of the present invention, a thick and bulky tape is preferable. Further, from the viewpoint of improving ventilation, it is preferable that the material is not too soft and has a certain rigidity.
The aspect ratio refers to the ratio between the long side and the short side, but in the present invention, it refers to the ratio between the tape width and the tape thickness of the warp tape slit for weaving.

Further, a coating sheet for tea plants is provided, wherein at least one kind of filler is a substance that absorbs ultraviolet light.

As described above, the blackened fiber generally used as a coating material does not have a selective light-shielding property, and the quality as a high-grade tea is said to be inferior to that of the blind coating. At least one of the fillers according to the present invention is a substance having a property of absorbing ultraviolet light. The sunlight radiated to the white reflective tape is reflected, but some of the sunlight enters the tape and passes through the tape. Since the ultraviolet light among the transmitted light that has reached the filler is absorbed based on the absorption spectrum peculiar to the contained filler, the transmission of the ultraviolet light among the transmitted light under the sheet is reduced. If there is only one type of filler, the filler is a white pigment and is a substance having a property of absorbing ultraviolet light. In the case of two or more types of fillers, one or two or more of them are substances having ultraviolet light absorption, and the other one or two or more types are white pigments, and the entire filler absorbs ultraviolet light. It may also be said that it exerts the functions of sex and sheet whitening.
The type of filler that absorbs ultraviolet light is not limited, but titanium oxide, which has ultraviolet light absorption and is also a white pigment, is preferable.

Further, there is provided a tea plant sheet, which comprises a plurality of types of the filler, at least a filler which is a white pigment that absorbs ultraviolet light and a filler having high reflectivity of visible light and infrared light.

For the purposes of the present invention, a plurality of fillers having different light-shielding properties can be combined. It is also a promising combination to combine the above-mentioned filler having an ultraviolet light absorption effect with a filler having high reflectivity of visible light and infrared light.

Further provided is a tea plant sheet characterized in that the warp is a monofilament, a flat monofilament or a plyed tape.

As mentioned above, hot air tends to be trapped inside the shelf facility or under the direct hanging material, and there is almost no air permeability. In particular, since the heat transfer efficiency is high in the direct coating, the adverse effect due to insufficient air permeability is large in both high temperature and low temperature. In the present invention, in order to ensure breathability, the black material to be woven is a monofilament having a bulky shape, a flat monofilament, or a plying tape. The shape of the sheet woven with monofilament, flat monofilament or plying tape is three-dimensional. That is, the white reflective tapes, which are warps, are juxtaposed without gaps in a plan view, but in a side view, they have a shape that undulates up and down due to weaving with bulky wefts. This swell creates space on the sides of the white reflective tape. Due to this space, the wind blowing on the side of the white reflective tape reaches the tea plant below.

Any material other than monofilament, flat monofilament, and plying tape, which has a bulky shape, can be used as a warp and weft. This is because the air permeability can be improved as well.

Further, a sheet for tea plants, characterized in that the weaving method is double-sided diagonal weaving, is provided.

In the diagonal weave, the space between the warp and the weft is increased by reducing the number of places where the warp intersects with the warp as compared with the plain weave. Weaves and entwined weaves are not appropriate as they add more space and create a too loose texture. The same effect can be obtained regardless of which is the upper surface (lower surface) by using the double-sided diagonal weave.

A sheet for tea plants is provided, wherein the weaving method is a 3/4, 1/1 double-sided diagonal weave.

In consideration of the balance between creating a three-dimensional void in the sheet and the looseness of the allowable structure, a 3/3 and 1/1 double-sided diagonal weave was used. In addition, double-sided weft weaving is a weaving method in which warps straddle multiple wefts and weave them in a staggered manner (oblique weaving). ) The same number of wefts. The appearance of the warp and weft is the same on both sides. 3/3 is also called a three-sheet diagonal weave, and refers to a diagonal weave in which warps and wefts repeat ups and downs in units of three. 3/3/3/1 is a deformation of 3/3. After the warp straddles three wefts, it passes through three wefts, and after straddling one weft, it passes through one weft. This means a pattern in which the unit is repeated.

A sheet for tea plants is provided, wherein the weaving method is a weaving in which double-sided diagonal weave and plain weave are arranged at regular intervals.

By inserting the plain weave into the weave part at regular intervals, the jumping yarn of the weave is loosened. This is because the consumption of warps supplied from the same beam differs between diagonal weave and plain weave.

By using a white reflective tape in which the warps are juxtaposed without gaps and a black material for the wefts, it has become possible to provide a covering sheet that has both light-shielding and heat-shielding properties. When the warp is a black material and the weft is a white reflective tape, when both the warp and the weft are black materials, and when both the warp and the weft are white reflective tape, the object of the present invention cannot be achieved. In the present invention, by adjusting the coarseness and density of the arrangement of the black material which is the weft, it is possible to exhibit a light-shielding property comparable to that of the blackened fiber.

The surface of the white reflective tape according to the present invention is white based on a white pigment, and the light reflectivity thereof suppresses the temperature rise of the coating sheet. The tea plant under the covering sheet can prevent harmful effects such as leaf burning due to an increase in the sheet temperature. In the case of a white pigment by internal kneading, it is uniformly and inexpensively contained in the stretched reflective tape.

Due to the structure of the present invention, both surfaces of the stretched reflective tape have the same white color and exhibit the same surface uneven shape. Therefore, even if the stretched reflective tape is twisted in the weaving process and the upper surface and the lower surface are exchanged, there is no difference in the effect. It can be effective as a reversible material.

Further, in the tea plant coating sheet according to the present invention, a large number of protrusions are formed on the surface and a large number of pigments are present inside the olefin-based resin, and the structure increases the surface reflectance and the internal reflectance of the sheet. ..
Even the incident light that has once entered the inside is emitted as diffuse reflected light from the tape surface due to reflection on the pigment surface or reflection via refraction in the void, so that the light shielding property and the heat shielding property are improved. The diffusely reflected light refers to the reflected light excluding the specularly reflected light. Due to these synergistic effects, the tape according to the present invention has a higher reflectance than a simple white tape, and can prevent the temperature rise of the sheet and the heat storage effect.

By making the stretched tape as thin as possible, it is possible to promote the generation of protrusions on the surface of the tape having pigments and voids as cores and the increase in the size of the protrusions. Further, by increasing the particle size of the pigment as much as possible to the extent that holes are not generated in the tape, voids can be generated to be larger, and the protrusions on the surface of the olefin resin tape can be made larger and higher.

Further, by increasing the weight% of the pigment in the olefin resin as much as possible, the density of the pigment present in the olefin resin is increased. As a result, the number of protrusions generated on the tape surface increases, and the diffuse reflectance increases. Furthermore, as the pigment density increases, the possibility that another pigment is present inside the pigment near the tape surface increases, and the incident enters the inside without hitting the pigments and voids on the surface and near the surface of the olefin resin. Light is also more likely to be reflected by the internal pigment. As a result, the overall reflectance is further increased.

By setting the tape width and tape thickness of the warp to 20: 1 to 45: 1 in aspect ratio, it is possible to prevent the tape from folding in the width direction during weaving while ensuring the formation of protrusions due to thinning. can.

By having a filler which is a white pigment that absorbs ultraviolet light in the white reflective tape, it becomes possible to exhibit selective light blocking effect. As described above, the blackened fiber does not have a difference in the light-shielding rate depending on the wavelength, whereas the blind coating has a selectively high light-shielding rate with respect to the ultraviolet light region. There is a report that it causes a difference in quality. The coating sheet according to the present invention is as easy to handle as the blackened fiber, but has a selective light-shielding property against ultraviolet light, so that it is possible to produce tea leaves of higher quality than the blackened fiber. ..

By containing a plurality of fillers having different properties, it is possible to selectively maintain a high light-shielding rate with respect to the ultraviolet light region and maintain a higher level of light-shielding property in the visible light or infrared light region.

By forming the weft into a three-dimensional shape of monofilament, flat monofilament or plying tape, it becomes possible to guide the wind downward from the side surface of the monofilament or plying tape, and the air permeability to the tea plant is improved. As a result, it is possible to reduce harmful effects such as leaf burning of tea plants under high temperature and low temperature.

By increasing the space between the warp and weft based on the double-sided diagonal weave, the breathability of the sheet can be improved. There is no trade-off between improved breathability and light blocking effect. The increase in space due to diagonal weaving means that the warp and weft overlap loosely in the part where the warp and weft do not intersect, creating space. In this case, in the plan view, the diagonal weaves overlap as well as the plain weaves, and there is no difference. Therefore, the effect of the light-shielding property on the sunlight radiated from above is minor. By using double-sided diagonal weaving, the same effect can be obtained regardless of which of the sheets is used as the upper surface.

By using a 3/3 double-sided weave, it is possible to provide a sheet that improves breathability while considering light-shielding properties. It is necessary to improve the air permeability while ensuring the necessary light-shielding property, but from that viewpoint, 3/3 and 1/1 are preferable. It should be noted that the pattern in which 1/1 is added instead of only 3/3 is that the intersection of the warp and weft is small in the diagonal weaving pattern of only 3/3, and the wefts are misaligned, resulting in morphological stability. Because it is lacking.

By arranging the double-sided diagonal weave and the plain weave at regular intervals, it is possible to exert the same effect of improving the breathability as the full-scale diagonal weave. Further, by including the plain weave, the shape stability of the sheet can be improved as compared with the full-face diagonal weave.

It is a partial plane image of the coating sheet for tea plant which concerns on Example 1 in this invention. It is a partial slope image of the coating sheet for tea plant which concerns on Example 1 in this invention. It is a partial plane image of the coating sheet for tea plant which concerns on Example 2 in this invention. It is a partial slope image of the coating sheet for tea plant which concerns on Example 2 in this invention. FIG. 1 is a partial image 1 of a coating sheet for tea plants according to Comparative Example 1 in the present invention. FIG. 2 is a partial image 2 of a coating sheet for tea plants according to Comparative Example 1 in the present invention. It is an enlarged partial image of the coating sheet for tea plant which concerns on Comparative Example 2 in this invention. It is a partial image of the coating sheet for tea plant which concerns on Example 2 in this invention. It is a plane conceptual diagram of the double-sided diagonal weave in this invention. It is a design drawing of the double-sided diagonal weave in this invention. It is sectional drawing conceptual figure of the double-sided diagonal weave in this invention. It is a plane conceptual diagram of a plain weave. It is a plain weave design drawing. It is a cross-sectional conceptual diagram of a plain weave. It is a conceptual diagram of the shading rate measuring apparatus in this invention. It is a shading rate for each wavelength for Examples and Comparative Examples in the present invention. It is the reflectance for each wavelength about the Example and the comparative example in this invention.

The present invention will be described in more detail below. In order to achieve the object of the present invention, the coating sheet for tea plant according to the present invention adopts a structure significantly different from the conventional general light-shielding material for tea plant represented by blackened synthetic fiber.

In the past, black warps were juxtaposed at a coarse density, and the density of the black tape, which is the weft, was changed to adjust and secure the shading rate and air permeability.

In the present invention, first, it is decided to maintain the light-shielding ratio while improving the heat-shielding property. For this reason, we decided to use white reflective tape for the warp and weave it side by side without gaps, and to ensure high light-shielding properties, we used a black material for the weft to adjust the roughness of the black material. It was decided to adjust the shading rate of the entire sheet at a high level by selecting the fineness.

Examples of the material of the white reflective tape used as the warp include high-density polyethylene, a linear copolymer, polypropylene and the like as the polyolefin resin used for the stretched tape made of polyolefin. As polypropylene, a propylene homopolymer, an ethylene-propylene block copolymer, an ethylene-propylene random copolymer, or a mixture thereof can be used. Among these, high-density polyethylene and polypropylene are preferable, and high-density polyethylene has a melt flow rate of 0.4 to 1.0 g / g / 1.0 g / 10 minutes, 0.8 to 6 g / 10 minutes of polypropylene is preferable.

Next, the black material used as the warp and weft will be described. Examples of the black material used as the weft include a drawn monofilament made of polyolefin, and examples of the polyolefin resin used for the tape include high-density polyethylene, a linear copolymer, polypropylene and the like. As polypropylene, a propylene homopolymer, an ethylene-propylene block copolymer, an ethylene-propylene random copolymer, or a mixture thereof can be used. Among these, high-density polyethylene and polypropylene are preferable, and high-density polyethylene has a melt flow rate of 0.4 to 1.0, considering mechanical properties such as stretched monofilament and tape strength, extrusion formability at the time of manufacturing, and stretchability. It is preferably g / 10 minutes, and polypropylene is preferably 0.8 to 6 g / 10 minutes. For the black material that is the weft, select a shape close to a round cross section in order to create its three-dimensional structure. For example, a monofilament, a flat monofilament obtained by crushing a monofilament, and a tape are twisted to form a bulkier shape than the tape. The light-shielding property is adjusted by adjusting the coarseness and density of the warp and weft and selecting the fineness.

As the filler contained in the white reflective tape of the coating sheet for tea plant, only a white pigment having ultraviolet light absorption may be used. The covering sheet has high light-shielding and heat-shielding properties, and selectively has high light-shielding properties in the ultraviolet light region. Further, it can be used as two types, a white pigment having an ultraviolet light absorption property and a filler having high reflectivity of visible light and infrared light. By such a combination, the coating sheet for tea plant has a higher heat-shielding property and selectively has a high light-shielding property in the ultraviolet light region. The types and combinations of fillers contained in the white reflective tape are not limited to these. For example, when an infrared reflective pigment other than white is contained, a substance other than the pigment, which has high reflectivity of visible light or infrared light, and a substance having ultraviolet light absorption are not excluded.

The filler will be specifically described. In the white reflective tape (composition) according to the present invention, as the filler (inorganic filler) to be mixed with the polyolefin resin, known ones conventionally used in the production of films are used. For example, calcium carbonate, titanium oxide, talc, calcium sulfate, calcium sulfite, calcium phosphate, magnesium carbonate, hydrated silicic acid, anhydrous silicic acid, soda ash, barium sulfate, and other inorganic substances or organic metal salts mainly composed of inorganic substances are mentioned. Can be done.

Of these examples, barium sulfate, titanium oxide, calcium carbonate, talc and the like are preferable, and titanium oxide and calcium carbonate having a small particle size and a large surface area are particularly preferable.

In the present invention, the particle size of the inorganic filler, particularly calcium carbonate, is 0.1 to 15 μm because it greatly affects the formation and reflection of the obtained polyolefin tape, and the average particle size is 3 to 6 μm. preferable. If the particle size is small, it is difficult to generate voids, and micro unevenness on the tape surface cannot be formed. In addition, if the particle size is large or the content is high, uniform dispersion is difficult, film formation cannot be maintained, and a hole (fish eye) phenomenon occurs in the unstretched film, which makes it difficult to stretch and tape. ..

Titanium oxide has a property of absorbing ultraviolet light, but reflects visible light and infrared light, so that the sheet temperature does not rise and the heat-shielding property for the coated tea leaves can be maintained. The particle size of titanium oxide is not particularly limited, but a particle size of 0.2 to 0.3 μm, which is generally used for pigments, can be used as a reflection / shielding effect of the present invention.

Further, various known additives such as a light stabilizer, an antioxidant, an antistatic agent, a crystal nucleating agent, a surfactant, a foaming agent, a flame retardant, and a dispersant are used in the composition of the present invention, if necessary. It may be blended in a range that does not impair the effect of.
Further, the method of mixing the polyolefin resin and the inorganic filler is not particularly limited, and a known method can be adopted.

A method for manufacturing a white reflective tape according to the present invention will be described. Examples of the film forming method include known methods such as T-die water cooling method, T-die chill roll method, water cooling, and air-cooled inflation method. Next, the obtained unstretched film is slit to a width corresponding to the fineness after stretching. Examples of the slit include a known method, for example, a leather blade assembled to the width of the slit, a rotary cutter (round blade), and the like. Next, the slit unstretched tape is stretched in the flow direction while applying heat at a predetermined magnification to impart fineness (tape thickness), width, thickness shape, and mechanical characteristics suitable for woven and knitted fabrics. It is a thing.

It is generally known that stretching an unstretched film causes peeling at the interface between the polyolefin resin and the inorganic filler to form voids. The effect is obtained by stretching and thinning the unstretched film to which the inorganic filler particle size is added, which is a feature of the present invention, so that the fine particles contained therein are exposed on the surface of the stretched tape at the same time as the voids are generated. As long as the final thickness can be secured, the draw ratio is not particularly limited, but is preferably in the range of 4 to 9 times.

Next, for the dimensional stability of the woven and knitted fabric, the strain generated by stretching is heated and relaxed to remove it. The fineness (thickness) of the stretched tape is not particularly limited, but is 100 to 3000 decitex (hereinafter referred to as dt) from the formability as a woven and knitted fabric, and is preferably in the range of 200 to 2000 dt.

The weaving method will be described. First, "I will explain how to weave white reflective tapes side by side without gaps. Regarding the arrangement of warps, if the warp density of the woven fabric is 24 lines / 2.54 cm, the warp tapes are 24 stitches / 2.54 cm. The number of reeds (the one in which the warp densities of the woven fabrics are regularly arranged) is passed according to the required weaving width. In this case, the 1.058 mm wide tape calculated from 2.54 / 24 is passed through the reeds. However, in weaving, selecting a slightly wider tape width (for example, width 1.2 mm) so that the tapes do not break and a slight overlap occurs prevents the occurrence of gaps. From the point of view, it is more preferable.

A double-sided diagonal weave was used for the weaving method, creating a three-dimensional structure with a space when viewed from the side. The three-dimensional structure and the use of bulky wefts have improved breathability. The weaving method is not limited to the double-sided diagonal weave, and a weave having another three-dimensional structure such as a double-sided diagonal weave and a plain weave arranged at regular intervals may be used. Even if a slight space is formed on the side surface due to the three-dimensional structure, the direction of the space does not match the angle of the irradiation light emitted from above. Therefore, the formation of the space has some influence on the light blocking effect, but does not have a serious influence. In the case of double-sided diagonal weaving, 3/3/3/1/1 double-sided diagonal weaving is particularly preferable in consideration of the balance between improving breathability and maintaining light-shielding property.

Hereinafter, Examples and Comparative Examples will be shown, but the present invention is not limited to these Examples. The measured values of physical properties shown in Examples and Comparative Examples were carried out by the methods shown below.
1) Breathability measurement
JIS L 1096 A method (Frazier type method)
2) Diffuse reflectance, transmittance SolidSpec 3700DUV manufactured by Shimadzu Corporation
3) Heat shield test The specific work of the heat shield test shown in FIG. 11 will be described. In the case of the heat insulation test of JIS L 1951 fabric, a ref lamp is used as the light source 51. Further, a light receiving body is arranged on the back surface of the sample in a non-contact manner, and the heat of solar radiation (radiant heat) that has passed through the sample 52 is absorbed by the light receiving body. The rising temperature of the light receiving body 53 to which the sample 52 is attached is measured by irradiating with light for an arbitrary time.
[Example 1]

A composition containing 76% by weight of polypropylene (MI = 2.4 g / 10 minutes, density = 0.9, melting point = 163 ° C.) and 24% by weight of calcium carbonate having an average particle size of 5 μm added thereto to 100 parts by weight. It is a mixture in which 6 parts by weight of titanium oxide and 0.5 parts by weight of a weather resistant agent are added. After mixing them using a heavy-duty automatic raw material mixing device, the resin is mixed with a T-die of a screw 65 mmφ extruder. It was extruded and cooled with a chill roll to form a film.

As the conditions, an unstretched film having a thickness of 100 μm was formed under the conditions of a cylinder temperature of 240 ° C., a die temperature of 225 ° C., and a take-up speed of 14 m / min. The film was slit and stretched 7 times in the vertical direction at 100 ° C. to obtain a stretched tape having a width of 1.2 mm, a thickness of 50 μm, and a fineness of 580 dt.

The obtained stretched tape was used as a warp and had a density of 24 threads / 2.54 cm, and a black 1600 dt thread having a flat cross section of a monofilament was woven into a weft with a density of 12 threads / 2.54 cm. As a weaving method, weaving was performed by double-sided diagonal weaving of 3/3 and 1/1. Various characteristics of the obtained sheet were measured by the above method.

A plan view of the double-sided diagonal weave of 3/3 and 1/1 is shown in FIG. 9A, a design drawing is shown in FIG. 9B, and a cross-sectional view is shown in FIG. 9C. Further, a plan view of a plain weave is shown in FIG. 10A, a design drawing is shown in FIG. 10B, and a cross-sectional view is shown in FIG. 10C. In both plan views and both design drawings, the warp threads 2 are connected in the vertical direction, and the weft threads 3 are connected in the horizontal direction. In both cross-sectional views, the black circle in the center indicates the warp and weft 3, and the dotted or solid line indicates the warp and weft 2.

A partial plan view of the covering sheet according to the first embodiment is shown in FIG. 1 is a part of the coating sheet for tea plants according to the present invention. The white warp 21 is a reflective tape according to the present invention. The black weft 31 is a flat monofilament. In the partial plan view, the gap portion of the sheet is not found due to the warp threads juxtaposed without gaps. Next, a partial slope view of the same covering sheet is shown in FIG. Since the weft 31 is bulky, the width of the ups and downs of the warp is large, and a gap 4 in the side surface direction is generated around the portion intersecting the weft. Therefore, although it does not have much effect on the shading of sunlight radiated from above, the air permeability is greatly improved.
[Example 2]

The warp direction was the same as in Example 1 for both the type and density of the yarn, and the same yarn as in Example 1 was used for the yarn in the weft direction, and only the density was 15 yarns / 2.54 cm. The weaving method was the same 3/3/1/1 double-sided diagonal weaving.

A partial plan view of the covering sheet according to the second embodiment is shown in FIG. 1, and a partial slope view is shown in FIG. The wefts 31 were arranged 25% more densely than in Example 1. Therefore, the width of the void 4 in the side surface direction is reduced and the void area is smaller than that of the first embodiment.
[Comparative Example 1]

For the examples, a commonly used black synthetic fiber sheet, specifically, a monofilament toned with high-density polyethylene carbon black corresponding to the warp, is arranged at a pitch of about 12 mm, and black is made of polypropylene corresponding to the weft. A comparative test was conducted on a product in which a tape 32 (16 sheets / 2.54 cm) having a width of 2.3 mm, a thickness of 55 μm, and a thickness of 1100 dt was rasselled (warp-knitted) and had a light-shielding ratio of 85%.

The partial images of the covering sheet according to Comparative Example 1 are shown in FIGS. 5 and 6. The polypropylene tape 32 toned in black is connected in the horizontal direction of FIG. 5 and in the vertical direction of FIG.
[Comparative Example 2]

As a comparison with the current high-grade tea-coated light-shielding sheet for the examples, in detail, as the warp 2, high-density polyethylene (MI = 0.6 g / 10 minutes, density = 0.959, melting point = 134 ° C.). Four monofilaments 310t (10.7 / 吋) toned with carbon black made of carbon black are concentrated and arranged in one place, and the space between the four monofilaments is about 1 cm as in Example 1. A high-density polyethylene (MI = 0. A plain woven product provided with a monofilament 310t (14.4 / 吋) toned with carbon black made of 6 g / 10 minutes, density = 0.959, melting point = 134 ° C. was evaluated.

The partial images of the covering sheet according to Comparative Example 2 are shown in FIGS. 7 and 8. It is the aluminum-deposited composite slit tape 22 that has gloss.

FIG. 12 shows the shading rate for each wavelength measured for Examples 1 and 2 and Comparative Examples 1 and 2. The shading rate J1 according to Example 1 is a solid line, the shading rate J2 according to Example 2 is a broken line, Comparative Example 1 (H1) is a dotted line, and Comparative Example 2 (H2) is a alternate long and short dash line. In the visible light and near infrared light regions, there is no big difference as a whole, and the values are 85% inside and outside. When observed for each wavelength, in Example 1 and Example 2, a wavelength close to the ultraviolet light region shows a high light-shielding property of 10 points or more as compared with Comparative Example 1 and Comparative Example 2, while a region having a longer wavelength than that. Then, it is slightly downward to the right. In the case of Example 1, the light-shielding property in the near-infrared light region is about 5% lower. In the case of Example 2, it is not so inferior to Comparative Example 1 and Comparative Example 2, and in particular, it keeps almost the same light-shielding property as Comparative Example 1.

In the ultraviolet region, a remarkable difference is shown between Examples 1 and 2 and Comparative Examples 1 and 2. In Examples 1 and 2, the shading rate is about 100% in the entire ultraviolet light region, whereas in Comparative Examples 1 and 2, the shading rate is about 85%, which is a difference of about 15 points. There is.

The reflectance for each wavelength measured for Examples 1 and 2 and Comparative Examples 1 and 2 is shown in FIG. Comparative Example 1 (H1) has almost no reflectivity over the entire wavelength region. Examples 1 (J1) and 2 (J2) Comparative Example 2 (H2) show almost the same light-shielding ratio in the visible light region and the near-infrared light region, but Comparative Example 2 has 30 to 60% in the ultraviolet light region. In contrast to the reflectance, Examples 1 and 2 have a large deviation from the reflectance of about 10%. Considering that the light-shielding rate of the ultraviolet light region in FIG. 12 is about 100% in Examples 1 and 2 and about 85% in Comparative Example 2, Examples 1 and 2 have extremely high light-shielding property due to the ultraviolet light absorption. It is inferred that it has acquired.

Table 1 shows a summary of the light-shielding rate / reflectance and the measured values of the heat-shielding property / air permeability for Examples 1 and 2 and Comparative Examples 1 and 2. The numerical values of the light-shielding rate and the reflectance show the average light-shielding rate or the average reflectance of UVA having a wavelength of 315 to 380 nm, visible light having a wavelength of 380 to 800 nm, and near-infrared light having a wavelength of 800 to 2500 nm.

The shading rate and reflectance are as described above. Regarding the heat-shielding property, in the case of Example 1 and Example 2, a decrease of 11 ° C. was observed as compared with Comparative Example 1 which is a conventional general covering material, indicating that it has heat-shielding property. It is generally recognized that Comparative Example 2 has a high heat-shielding property due to the reflective effect of aluminum vapor deposition, but Examples 1 and 2 according to the present invention have equivalent values. The difference in placement density has an effect on breathability. The coarsely arranged Comparative Example 1 has excellent breathability and is superior to the other densely arranged examples. However, when Examples 1 and 2 are compared with Comparative Example 2, the air permeability is improved by 20% in Example 2 and 40% in Example 1. By selecting the wefts and the weaving method according to the present invention, it is presumed that the air permeability is improved even in the covering sheet woven by arranging the warps closely side by side.

The present invention is useful as a covering sheet for shelving and direct hanging. As for the demand for Japanese tea, the demand for sencha brewed in teapots is sluggish, while the demand for matcha, which is added to foods in a broad sense, is rapidly increasing, including exports. In order to meet this increase in demand, it is necessary to improve the cover cultivation more effectively and efficiently. The present invention meets that need and has high industrial applicability.

1 Tea plant covering sheet 2 Warp 21 White reflective tape (warp)
22 Aluminum-deposited composite tape (warp)
3 Warp 31 Black flat monofilament (warp)
32 Black tape (warp and weft)
4 Void 5 Shading rate measuring machine 51 Lamp 52 Sample 53 Receiver J1 Shading rate (or reflectance) according to Example 1.
J2 Shading rate (or reflectance) according to Example 2
Light-shielding rate (or reflectance) according to H1 Comparative Example 1.
Light-shielding rate (or reflectance) according to H2 Comparative Example 2.

Claims (8)

A large number of one or two or more types of fillers containing at least one type of white pigment are contained therein, and the filler and voids formed around the filler are formed on both surfaces by stretching and thinning an olefin resin film. It is a sheet formed by a combination of warp and weft, which is a white reflective tape on which a large number of protrusions are formed as a core, and weft, which is a black material, and the warp and weft are woven with the weft by arranging the warp without gaps. A characteristic coating sheet for tea trees. The coating sheet for tea plants according to claim 1, wherein the tape width and the tape thickness of the white reflective tape are 20: 1 to 45: 1 in aspect ratio. The coating sheet for tea plants according to claim 1 or 2, wherein at least one kind of filler is a substance that absorbs ultraviolet light. One of claims 1 to 3, wherein the filler is a plurality of types, and includes at least a filler which is a white pigment that absorbs ultraviolet light and a filler having high reflectance of visible light and infrared light. Sheet for tea tree described in section The tea plant sheet according to any one of claims 1 to 4, wherein the warp is a monofilament, a flat monofilament, or a plyed tape. The tea plant sheet according to any one of claims 1 to 5, wherein the weaving method is double-sided diagonal weaving. The sheet for tea plants according to claim 6, wherein the weaving method is a double-sided diagonal weaving of 3/3/3/1. The tea plant sheet according to any one of claims 1 to 5, wherein the weaving method is a weaving in which double-sided diagonal weave and plain weave are arranged at regular intervals.

Images