Germination-promoting polyurethane foam, and germination-promoting polyurethane foam binder

Abstract

To provide a polyurethane foam for germination that has a high germination rate and can be used for a variety of plants. [Solution] This technology provides a germination polyurethane foam having an upper surface for sowing seeds and a lower surface which is the opposite side of the upper surface, with five or more slits radiating from the center of the upper surface, and the slits penetrating from the upper surface to the lower surface. This technology also provides a germination polyurethane foam composite in which a plurality of germination polyurethane foams according to this technology are joined together in a separable state.

Description

[Technical Field]

[0001] This technology relates to a polyurethane foam for germination and a polyurethane foam binder for germination. [Background technology]

[0002] Polyurethane foam is widely used in various fields, from furniture such as sofas and chairs, bedding such as mattresses and pillows, clothing such as underwear, daily necessities such as dishwashing and cleaning sponges, vehicle and aircraft interior products such as car seats, electronic devices such as mobile phones, cameras, and televisions, electrical equipment such as home appliances, toys, general merchandise, and even seedling beds for hydroponics. Furthermore, various developments are underway to improve quality and add new functions according to each field and purpose.

[0003] For example, Patent Document 1 discloses a seed sheet for direct planting, which is constructed by making cuts in a soft or semi-rigid polyurethane foam sheet of appropriate thickness so that it can be separated into 25 to 30 small pieces in the short direction and 50 to 60 small pieces in the long direction, and fixing a small number of rice or wheat seeds of about 1 to 3 grains in each small piece. This prevents damage to the seeds from birds and wind, eliminates the need for seedling cultivation and planting, significantly reduces labor and costs, improves the germination rate, and further improves the harvest by thickening the stems during the growth process of the seeds.

[0004] Thus, technologies have been developed to process blocks such as polyurethane sheets into forms suitable for plant seedling cultivation. For example, Patent Document 2 discloses a nutrient block that provides nutrients to seeds, with a seed input pit at the tip of the nutrient block and a seed cultivation pit inside the seed input pit. The seed input pit is provided with a larger upper section than the lower section so that seeds fall into the seed cultivation pit along the surface of the seed input pit under the influence of gravity, and an incision is provided inside the seed cultivation pit that extends away from the seed cultivation pit and provides a growth passage for the root system that germinates from the seed. This improves sowing efficiency, thoroughly moistens the seeds, and improves the overall germination rate and uniformity of the seeds. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2001-245505 [Patent Document 2] Special Publication No. 2021-531753 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] As mentioned above, methods are being developed to improve the germination rate of plant seeds using polyurethane foam and the like, but there is a real need for further development of technologies that can be used for a wider variety of plants.

[0007] Therefore, the primary objective of this technology is to provide a polyurethane foam for germination that has a high germination rate and can be used for a variety of plants. [Means for solving the problem]

[0008] The inventor of this invention conducted diligent research to solve the aforementioned problems and discovered that differences in the shape of the surface on which seeds are sown affect the germination rate and root growth, leading to the completion of this technology.

[0009] In other words, this technology first has an upper surface for sowing seeds and a lower surface which is the opposite side of the upper surface, The upper surface is provided with five or more slits radiating from the center, The aforementioned slit provides a germination-promoting polyurethane foam that penetrates from the top surface to the bottom surface. The upper surface of the germination polyurethane foam according to this technology can be a flat surface. The number of slits in the germination polyurethane foam related to this technology can be designed to be 6 to 8. The germination polyurethane foam related to this technology can be used for taproot-type plants. This technology then provides a germinated polyurethane foam composite in which multiple germinated polyurethane foams related to this technology are bonded together in a manner that allows them to be separated from one another. [Brief explanation of the drawing]

[0010] [Figure 1] This is a schematic perspective view showing the first embodiment of the germination polyurethane foam 1 related to this technology. [Figure 2] This is a six-view diagram schematically showing the first embodiment of the germination polyurethane foam 1 related to this technology. [Figure 3] These are schematic cross-sectional views of the first embodiment of the germination polyurethane foam 1 related to this technology, shown along lines AA and BB. [Figure 4] This is a schematic plan view showing a modified example of the germination polyurethane foam 1 related to this technology. [Figure 5] This is a schematic diagram illustrating an example of a method for hydroponic cultivation using the germination polyurethane foam 1 related to this technology. [Figure 6] This is a schematic perspective view showing a first embodiment of the germination polyurethane foam binder 10 related to this technology. [Figure 7] It is a six-sided view schematically showing a first embodiment of the polyurethane foam conjugate 10 for germination according to the present technology. [Figure 8] It is a cross-sectional view taken along line C-C, a cross-sectional view taken along line D-D, and a cross-sectional view taken along line E-E schematically showing a first embodiment of the polyurethane foam conjugate 10 for germination according to the present technology. [Figure 9] It is a six-sided view schematically showing the polyurethane foam for germination 1 with the portion indicated by the solid line in FIGS. 7 and 8 separated. [Figure 10] It is a perspective view schematically showing a second embodiment of the polyurethane foam conjugate 10 for germination according to the present technology. [Figure 11] It is a plan view and a cross-sectional view taken along line F-F schematically showing the form of the polyurethane foam for germination used in the examples. [Figure 12] It is a cross-sectional view schematically showing the water level during cultivation in the examples. [Figure 13] It is a graph showing the measurement results of the germination rate in the examples.

Embodiments for Carrying Out the Invention

[0011] Hereinafter, preferred embodiments for carrying out the present technology will be described. The embodiments described below show an example of typical embodiments of the present technology, and any of the embodiments can be combined. Also, the scope of the present technology is not construed narrowly by these.

[0012] 1. Polyurethane foam 1 for germination FIG. 1 is a perspective view schematically showing a first embodiment of the polyurethane foam 1 for germination according to the present technology. FIG. 2 is a six-sided view schematically showing a first embodiment of the polyurethane foam 1 for germination according to the present technology. FIG. 3 is a cross-sectional view taken along line A-A and a cross-sectional view taken along line B-B schematically showing a first embodiment of the polyurethane foam 1 for germination according to the present technology.

[0013] The germination polyurethane foam 1 according to this technology has an upper surface 11 for sowing seeds and a lower surface 12 which is the opposite side of the upper surface 11. It also has five or more slits 13 radiating from the center of the upper surface 11. On the upper surface 11, each slit 13 is a straight line of a predetermined length. One end of each slit 13 is connected to one another and converges at a single point in the center of the upper surface 11. The other ends of each slit 13 are arranged on the upper surface 11 so as to surround the center of the upper surface 11 while maintaining a distance from each other (for example, at equal intervals). These slits 13 penetrate from the upper surface 11 to the lower surface 12 (see cross-sectional view in Figure 3). In this specification, the length direction between the upper surface 11 and the lower surface 12 may be referred to as the "vertical direction" or "thickness direction".

[0014] In the germination polyurethane foam 1 according to the first embodiment, an example with 8 slits 13 is shown, but it is not limited to this. In this technology, the number of slits 13 can be freely designed as long as there are 5 or more slits, as long as the function and effect of this technology are not impaired. For example, modified examples 1 to 3 with 5 to 7 slits 13 are shown in Figure 4. In this technology, in particular from the viewpoint of improving germination, the lower limit of the number of slits 13 is preferably 6 or more, more preferably 7 or more, and even more preferably 8 or more. As shown in the examples described later, in this technology, it has been found that by setting the number of slits 13 to 5 or more, germination is improved, and the roots can be prevented from creeping along the top surface 11, and the roots can grow straight towards the bottom surface 12 by passing through the slits 13 that penetrate in the thickness direction.

[0015] There is no particular upper limit to the number of slits 13, but for example, it is 10 or less, preferably 9 or less, and more preferably 8 or less. Setting the upper limit of the number of slits 13 within this range makes processing easier, improves the shape retention of the foam, and prevents the foam from collapsing during use.

[0016] The length of the slit 13 can be freely designed according to the type of plant being sown and the characteristics of its roots, as long as it does not impair the function and effect of this technology. The lower limit of the length of the slit 13 from the center to the end in the planar direction is, for example, 3.0 mm or more, preferably 3.5 mm or more, and more preferably 4.0 mm or more. By setting the lower limit of the length of the slit 13 within this range, germination can be further improved, and the roots can be prevented from creeping along the upper surface 11, allowing them to grow straight towards the bottom surface 12.

[0017] The upper limit of the length of the slit 13 from its center to its end in the planar direction is, for example, 10.0 mm or more, preferably 9.5 mm or more, and more preferably 8.0 mm or more. By setting the upper limit of the length of the slit 13 within this range, the shape retention of the foam can be improved, and the foam shape can be prevented from collapsing during use.

[0018] The upper surface 11 of the germination polyurethane foam 1 according to this technology is preferably a flat surface. As with the prior art described in Patent Document 2 above, it was previously thought that having a recess on the upper surface where sowing takes place would improve germination. However, as shown in the examples described later, in this technology, we have found that a flat upper surface 11 where sowing takes place not only improves germination but also prevents the roots from creeping along the upper surface 11, allowing the roots to enter the slits 13 that extend in the thickness direction and grow straight towards the bottom surface 12.

[0019] The germination polyurethane foam 1 according to this technology allows the plant roots to grow straight towards the bottom surface 12 after germination, and is therefore particularly suitable for use with taprooted plants. Examples of taprooted plants include deep-rooted plants such as tomatoes, eggplants, watermelons, turnips, radishes, carrots, cabbage, Chinese cabbage, burdock, spinach, okra, green beans, and cowpeas; and shallow-rooted plants such as cucumbers, pumpkins, bitter melons, melons, cantaloupes, bell peppers, edamame, broad beans, peas, peanuts, leafy greens, lettuce, and garland chrysanthemum. This technology is particularly suitable for use with deep-rooted plants.

[0020] Furthermore, since the germination polyurethane foam 1 related to this technology has five or more slits 13, plant roots can grow straight through the slits 13 towards the bottom surface 12, and at the same time contribute to the spread of roots in the lateral direction. For this reason, it can be used not only for taprooted plants but also for fibrous rooted plants. Examples of fibrous rooted plants include potatoes, sweet potatoes, strawberries, taro, ginger, leeks, onions, garlic, and chives.

[0021] The permeability of the germination polyurethane foam 1 according to this technology can be freely set as long as it does not impair the function or effect of this technology. The lower limit of the permeability of the germination polyurethane foam 1 according to this technology is, for example, 20 L / min or more, preferably 25 L / min or more, and more preferably 30 L / min or more. By setting the lower limit of the permeability of the germination polyurethane foam 1 within this range, it is possible to improve seedling cultivation properties such as germination rate and root growth without impairing the flexibility of the germination polyurethane foam 1 (preventing it from becoming hard).

[0022] The upper limit of the air permeability of the germination polyurethane foam 1 according to this technology is, for example, 150 L / min or less, preferably 145 L / min or less, and more preferably 140 L / min or less. By setting the air permeability of the germination polyurethane foam 1 within this range, the support for seedlings and other properties can be improved.

[0023] In this technology, the air permeability was measured using a method compliant with ASTM D3574.

[0024] The density of the germination polyurethane foam 1 related to this technology can be freely set as long as it does not impair the function or effect of this technology. The lower limit of the density of the germination polyurethane foam 1 related to this technology is, for example, 10 kg / m³. 3 Preferably 11 kg / m 3 More than 12 kg / m 3That concludes the explanation. By setting the lower limit of the density of the germination polyurethane foam 1 within this range, the seedling support and other properties can be improved.

[0025] The upper limit of the density of the germination polyurethane foam 1 related to this technology is, for example, preferably 60 kg / m³. 3 For the following, a more preferable rate is 55 kg / m 3 More preferably 50 kg / m 3 The following is true: By setting the density of the germination polyurethane foam 1 within this range, it is possible to improve seedling cultivation properties such as germination rate and root growth without compromising the flexibility of the germination polyurethane foam 1 (preventing it from becoming hard).

[0026] In this technology, the density is measured using a method compliant with JIS K7222:2005.

[0027] The number of cells in the germination polyurethane foam 1 can be freely set as long as it does not impair the function or effect of this technology. The lower limit of the number of cells in the germination polyurethane foam 1 according to this technology is, for example, 5 cells / 25 mm or more, preferably 10 cells / 25 mm or more, more preferably 15 cells / 25 mm or more, and even more preferably 20 cells / 25 mm or more. By setting the lower limit of the number of cells in the germination polyurethane foam 1 within this range, seedling growth performance such as germination rate can be improved.

[0028] The upper limit of the number of cells in the germination polyurethane foam 1 according to this technology is, for example, 70 cells / 25 mm or less, preferably 65 cells / 25 mm or less, and more preferably 60 cells / 25 mm or less.

[0029] In this technology, the number of cells is measured according to the method specified in the JIS K 6400-1 Annex.

[0030] The polyurethane foam 1 for germination according to the present technology can be freely designed in other forms as long as it has an upper surface 11 for seeding and a bottom surface 12 which is the reverse side of the upper surface 11. In FIGS. 1 to 4, an example of a quadrangular prism is shown, but it is not limited thereto, and examples include prisms such as triangular prisms, pentagonal prisms, hexagonal prisms, heptagonal prisms, octagonal prisms, and cylinders.

[0031] The area of the upper surface 11 can also be freely designed according to the type and amount of seeds to be sown, the type of plants, the characteristics of the roots, etc. As the lower limit of the area of the upper surface 11, for example, 2.5 cm 2 or more, preferably 3.0 cm 2 or more, more preferably 3.5 cm 2 or more, still more preferably 4.0 cm 2 or more. As the upper limit of the area of the upper surface 11, for example, 25 cm 2 or less, preferably 20 cm 2 or less, more preferably 15 cm 2 or less, still more preferably 10 cm 2 or less.

[0032] Similarly, the area of the bottom surface 12 can also be freely designed according to the type of plants to be sown, the characteristics of the roots, etc. As the lower limit of the area of the bottom surface 12, for example, 2.5 cm 2 or more, preferably 3.0 cm 2 or more, more preferably 3.5 cm 2 or more, still more preferably 4.0 cm 2 or more. As the upper limit of the area of the bottom surface 12, for example, 25 cm 2 or less, preferably 20 cm 2 or less, more preferably 15 cm 2 or less, still more preferably 10 cm 2 or less.

[0033] Note that the upper surface 11 and the bottom surface 12 do not have to be in the same form. For example, in order to improve the water absorption amount from the bottom surface 12, it is also possible to design the area of the bottom surface 12 to be wider than the area of the upper surface 11, or conversely, to design the area of the bottom surface 12 to be narrower than the area of the upper surface 11.

[0034] The thickness from the top surface 11 to the bottom surface 12 can also be freely designed according to the type of plant to be sown and the characteristics of its roots. The lower limit of the thickness is, for example, 1.5 cm or more, preferably 2.0 cm or more, and more preferably 2.5 cm or more. The upper limit of the thickness is, for example, 5.0 cm or less, preferably 4.5 cm or less, and more preferably 4.0 cm or less.

[0035] The polyurethane foam 1 for germination according to this technology can be suitably used for germination from sowing to germination, but can also be used as is for seedling cultivation after germination. The polyurethane foam 1 for germination according to this technology can be used in all germination and seedling cultivation methods, but can be used particularly well in seedbeds for hydroponic cultivation. Hydroponics is a cultivation method in which plants are grown using water and liquid fertilizer as needed, without using soil, and the polyurethane foam 1 for germination according to this technology is very suitable for methods in which part or all of the germination and seedling cultivation period is carried out by hydroponics.

[0036] More specifically, examples include a method in which all stages from sowing to germination, seedling cultivation, and harvesting are carried out hydroponically using a seedbed made of germination polyurethane foam 1, and a method in which sowing and germination are carried out hydroponically using a seedbed made of germination polyurethane foam 1 related to this technology, and then transplanting the entire seedbed into soil when the roots have developed to a certain extent.

[0037] The germination polyurethane foam 1 related to this technology is particularly suitable for hydroponic cultivation methods in which all stages from sowing to germination, seedling cultivation, and harvesting are carried out hydroponically. An example of hydroponic cultivation using the germination polyurethane foam 1 related to this technology is shown in Figure 5. As shown in Figure 5, hydroponic cultivation can be carried out by circulating the cultivation water W using a pump P, for example. Liquid fertilizers and chemicals can also be added to the cultivation water W as appropriate.

[0038] It is possible to perform sowing, germination, and seedling cultivation all in the same cultivation tank, or to use a seedbed made of polyurethane foam 1 for germination according to this technology and perform sowing and germination in a small cultivation tank, and then transplant the entire seedbed into a large cultivation tank when the roots have developed to a certain extent. When using the same cultivation tank for sowing, germination, and seedling cultivation all in the same cultivation tank, it is preferable to have a control mechanism that can control the water level in the cultivation tank according to the development, such as a water level suitable for germination and a water level suitable for seedling cultivation.

[0039] 2. Polyurethane foam binder for germination 10 Figure 6 is a schematic perspective view showing a first embodiment of the germinated polyurethane foam assembly 10 according to this technology. In Figure 6, for illustrative purposes, one germinated polyurethane foam 1 is shown separated from the end. Figure 7 is a schematic six-view drawing showing a first embodiment of the germinated polyurethane foam assembly 10 according to this technology. Figure 8 is a schematic cross-sectional view along lines CC, DD, and EE showing a first embodiment of the germinated polyurethane foam assembly 10 according to this technology. Figure 9 is a schematic six-view drawing showing the germinated polyurethane foam 1 separated from the parts indicated by solid lines in Figures 7 and 8. The germinated polyurethane foam 1 according to this technology can be distributed individually, but it can also be distributed as a germinated polyurethane foam assembly 10 in which multiple foams are bonded together in a separable state.

[0040] A state in which the components are joined in a separable manner is, for example, a method in which a joint portion 101 is provided on a part of the side surface 14 of the germinated polyurethane foam 1, as shown in the example of the germinated polyurethane foam assembly 10 according to the first embodiment in Figure 6. Regarding the position of the joint portion 101, in the example of the germinated polyurethane foam assembly 10 according to the first embodiment shown in Figures 6 to 9, it is provided vertically in the center of the side surface 14 of the germinated polyurethane foam 1, but is not limited to this. For example, as in the germinated polyurethane foam assembly 10 according to the second embodiment shown in Figure 10, the joint portion 101 may be provided at the corner of the side surface 14 of the germinated polyurethane foam 1.

[0041] The number of joints 101 on the germination polyurethane foam 1 is not limited to providing four joints 101 on one germination polyurethane foam 1, as shown in the first embodiment in Figures 6 to 9 and the second embodiment in Figure 10, but can be freely designed. Although not shown, for example, two, three, five, six, seven, or eight joints 101 can be provided on one germination polyurethane foam 1.

[0042] The number of germinated polyurethane foam units 1 in the germinated polyurethane foam assembly 10 according to this technology is not limited to a configuration in which 35 germinated polyurethane foam units 1 are bonded together, as shown in the first embodiment 10 in Figures 6 to 9 and the second embodiment 10 in Figure 10, but can be freely designed. The lower limit of the number of germinated polyurethane foam units 1 in the germinated polyurethane foam assembly 10 can be set to, for example, 2 or more, preferably 4 or more, more preferably 8 or more, and even more preferably 12 or more. The upper limit of the number of germinated polyurethane foam units 1 in the germinated polyurethane foam assembly 10 can be set to, for example, 100 or less, preferably 80 or less, and more preferably 60 or less.

[0043] 3. Compositions for the manufacture of polyurethane foam The germination polyurethane foam 1 according to this technology is characterized by its form, and its raw materials and manufacturing method are not particularly limited. The germination polyurethane foam 1 according to this technology can be manufactured using a composition containing a polyol and a polyisocyanate. The composition used in the manufacture of the germination polyurethane foam 1 according to this technology may also contain a blowing agent, catalyst, foam stabilizer, etc., as needed. Each component will be described in detail below.

[0044] (1) Polyol The polyols that can be used in this technology can be freely selected from one or more types of polyols that can be used in the general manufacture of polyurethane foam, as long as they do not impair the function or effect of this technology. Examples of polyols include polyester polyols, polyether polyols, polyester ether polyols, polycarbonate polyols, polymer polyols, and the like.

[0045] (2) Polyisocyanates The polyisocyanates that can be used in this technology can be freely selected from one or more types of polyisocyanates that can be used in the general manufacture of polyurethane foam, as long as they do not impair the function or effect of this technology. Examples of polyisocyanates include aliphatic isocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, and dicyclohexamethane diisocyanate; aromatic isocyanates such as toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), naphthalene diisocyanate, xylylene diisocyanate, and polymeric polyisocyanate (crude MDI); and modified polyisocyanates obtained by modifying these.

[0046] The isocyanate index of the polyurethane foam is not particularly limited, as long as it does not impair the function or effect of this technology. In this technology, the lower limit of the isocyanate index is, for example, 80 or more, preferably 85 or more, and more preferably 90 parts by mass or more. By setting the lower limit of the isocyanate index within this range, the strength of the polyurethane foam produced can be improved.

[0047] The upper limit of the isocyanate index is, for example, 120 or less, preferably 115 or less, and more preferably 110 or less. By setting the upper limit of the isocyanate index within this range, it is possible to prevent the polyurethane foam from becoming too hard, brittle, and losing its flexibility, and to improve the elasticity of the polyurethane foam.

[0048] In this technology, the isocyanate index is calculated using the formula [(equivalent amount of polyisocyanate in the polyurethane foam manufacturing composition / equivalent amount of active hydrogen in the polyurethane foam manufacturing composition) × 100].

[0049] (3) Foaming agent As for the blowing agents that can be used in this technology, one or more types of blowing agents that can be used in the general manufacture of polyurethane foam may be freely selected and used, as long as they do not impair the purpose and effects of this technology. Examples of blowing agents include water, hydrocarbons, halogenated compounds, etc. Examples of hydrocarbons include cyclopentane, isopentane, n-pentane, etc. Examples of halogenated compounds include methylene chloride, trichlorofluoromethane, dichlorodifluoromethane, nonafluorobutyl methyl ether, nonafluorobutyl ethyl ether, pentafluoroethyl methyl ether, heptafluoroisopropyl methyl ether, etc. In this technology, it is preferable to use water as the blowing agent among these. The water may be deionized water, tap water, distilled water, etc.

[0050] The amount of blowing agent used in this technology can be freely set as long as it does not impair the function or effect of this technology. In this technology, the lower limit of the blowing agent content in the composition is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 1 part by mass or more, per 100 parts by mass of polyol. By setting the lower limit of the blowing agent content in the composition within this range, foaming properties can be improved, and as a result, polyurethane foam with excellent mechanical properties and appearance can be obtained.

[0051] In this technology, the upper limit of the foaming agent content in the composition is, for example, 20 parts by mass or less, preferably 15 parts by mass or less, and more preferably 10 parts by mass or less, per 100 parts by mass of polyol. By setting the upper limit of the foaming agent content in the composition within this range, it is possible to suppress formation defects due to excessive foaming.

[0052] (4) Catalyst As catalysts that can be used in this technology, one or more catalysts that can be used in the manufacture of polyurethane foam can be freely selected and used, as long as they do not impair the action or effect of this technology. Examples of catalysts include metal catalysts (organometallic catalysts) such as organotin compounds (dibutyltin dilaurate, tin octoate, tin 2-ethylhexanoate, etc.), organoiron compounds (iron acetylacetonate, etc.), organoniceric compounds (nickel acetylacetonate, nickel octoate, nickel naphthenate, etc.), organobismuth compounds (bismuth octoate, bismuth naphthenate, etc.), organolead compounds (lead octanoate, lead naphthenate, etc.), organocobalto compounds (cobalt acetylacetonate, cobalt octoate, cobalt naphthenate, etc.), organozirconium compounds (zirconium acetylacetonate, etc.), and organozinc compounds, as well as triethylamine, triethylenediamine (TEDA), tetramethylguanidine, diethanolamine, and bis(2-dimethylaminoethyl Examples of amine catalysts include ethers, N,N,N′,N″,N″-pentamethyldiethylenetriamine, imidazole compounds, piperazine amines such as N,N'-dimethylpiperazine, N,N',N'-trimethylaminoethylpiperazine, N-methyl-N'-(2-dimethylamino)ethylpiperazine, and N-methyl-N'-(2-hydroxyethyl)piperazine, morpholine amines such as N-methylmorpholine and N-ethylmorpholine, and amines referred to as DBU congeners such as 1,8-diazabicyclo-[5,4,0]-undecene-7 (DBU), 1,5-diazabicyclo-[4,3,0]-nonene-5 (DBN), 1,8-diazabicyclo-[5,3,0]-decene-7 (DBD), and 1,4-diazabicyclo-[3,3,0]octene-4 (DBO). In this technology, it is preferable to use one or more catalysts selected from organotin compounds, piperazine amines, morpholine amines, and DBU congeners, and it is more preferable to select one or more catalysts selected from dibutyltin dilaurate, N,N'-dimethylpiperazine, N,N',N'-trimethylaminoethylpiperazine, and N-ethylmorpholine 1,8-diazabicyclo-[5,4,0]-undecene-7(DBU).

[0053] The amount of catalyst in the composition used in this technology can be freely set as long as it does not impair the function or effect of this technology. In this technology, the lower limit of the catalyst content in the composition is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, and more preferably 1.0 part by mass or more, per 100 parts by mass of polyol. By setting the lower limit of the catalyst content in the composition within this range, various reactions during manufacturing can be controlled, and as a result, polyurethane foam with excellent mechanical properties and appearance can be obtained.

[0054] In this technology, the upper limit of the catalyst content in the composition is, for example, 10 parts by mass or less, preferably 9 parts by mass or less, and more preferably 8 parts by mass or less, per 100 parts by mass of polyol. By setting the upper limit of the catalyst content in the composition within this range, it is possible to prevent destabilization of various reactions during manufacturing. As a result, polyurethane foam with excellent mechanical properties and appearance can be obtained.

[0055] (5) Foam stabilizers A foam stabilizer can be used in the manufacturing of the polyurethane foam used in this technology. By using a foam stabilizer, a higher quality polyurethane foam can be manufactured.

[0056] As foam stabilizers that can be used in this technology, one or more types of foam stabilizers that can be used in the manufacture of polyurethane foam may be freely selected and used, as long as they do not impair the function or effect of this technology. Examples include silicone-based foam stabilizers, fluorine-containing compound-based foam stabilizers, surfactants, etc. Examples of silicone-based foam stabilizers include those mainly composed of siloxane chains, those in which siloxane chains and polyether chains form a linear structure, those that are branched and separated, and those in which polyether chains are modified into a pendant-like structure of siloxane chains.

[0057] The amount of foam stabilizer in the composition used in this technology can be freely set as long as it does not impair the function or effect of this technology. The lower limit of the foam stabilizer content in the composition is, for example, 0.1 parts by mass or more, preferably 0.5 parts by mass or more, per 100 parts by mass of polyol. The upper limit of the foam stabilizer content in the composition is, for example, 10 parts by mass or less, preferably 7 parts by mass or less, more preferably 5 parts by mass or less, per 100 parts by mass of polyol.

[0058] (6) Others In the manufacture of the polyurethane foam used in this technology, one or more components that can be used in the manufacture of polyurethane foam may be freely selected and used as other components, as long as they do not impair the function or effect of this technology, depending on the purpose. Examples of components that can be used in this technology include flame retardants, pigments, stabilizers, plasticizers, colorants, crosslinking agents, antibacterial agents, dispersants, fillers, antioxidants, and ultraviolet absorbers.

[0059] 4. Method for manufacturing polyurethane foam 1 for germination The germination polyurethane foam 1 related to this technology can be manufactured by mixing the components of the polyurethane foam manufacturing composition described above to prepare a composition, and then proceeding with a resinification reaction and a foaming reaction. The methods for the resinification reaction and foaming reaction can be freely combined using general methods, as long as they do not impair the action and effects of this technology.

[0060] In the manufacturing method of the germinated polyurethane foam 1 related to this technology, foaming can be carried out using any of slab foaming, batch foaming, or mold foaming. Slab foaming is a method in which a polyurethane foam manufacturing composition (raw material for polyurethane foam) is mixed and cast onto a moving conveyor, and foamed at atmospheric pressure and room temperature. Batch foaming is a method in which the mixture is extruded into a foaming box and foamed at atmospheric pressure and room temperature. On the other hand, mold foaming is a method in which a polyurethane foam manufacturing composition (raw material for polyurethane foam) is mixed and injected into the cavity of a mold (molding mold), and foamed into the shape of the cavity.

[0061] The manufactured polyurethane foam is processed into the forms of the germinated polyurethane foam 1 and germinated polyurethane foam composite 10 described above. The processing method can be one or more general polyurethane foam processing techniques, as long as it can be processed into the forms of the germinated polyurethane foam 1 and germinated polyurethane foam composite 10 described above. Examples include slicing, cutting, and punching.

[0062] Furthermore, this technology can be configured as follows: [1] It has an upper surface for sowing seeds and a lower surface which is the opposite side of the upper surface, The upper surface is provided with five or more slits radiating from the center, The slit is a germination-promoting polyurethane foam that penetrates from the top surface to the bottom surface. [2] The aforementioned upper surface is a flat surface, as described in [1], for germination polyurethane foam. [3] The germination polyurethane foam according to [1] or [2], wherein the number of slits is 6 to 8. [4] A germination polyurethane foam for taprooted plants, as described in any of [1] to [3]. [5] A germination polyurethane foam compound in which multiple germination polyurethane foams described in any of [1] to [4] are bonded together in a manner that allows them to be separated from one another. [Examples]

[0063] The present technology will be described in more detail below based on the following examples. The examples described below are representative examples of the present technology and should not be interpreted as narrowing the scope of the present technology.

[0064] (1) Method Three types of polyurethane foam (A-C) with different densities, cell counts, and air permeability, as shown in Table 1, were prepared. For each of the polyurethane foams A-C, 27 pieces were processed into four different forms as shown in Figure 11. Each polyurethane foam was generally in the shape of a vertically elongated rectangular parallelepiped (24mm x 24mm x 30mm). Each polyurethane foam was immersed in water, pressed to remove the air inside, and then placed in a tray with a culture medium for the polyurethane foam and rock wool (not shown). Water was then added as shown in Figure 12. Specifically, for the cross-shaped processing (Example) and cross-shaped processing (Comparative Example 1), water was added to the same height as the polyurethane foam, while for the perforated processing (Comparative Example 2) and perforated + cross-shaped processing (Comparative Example 3), water was added to the bottom surface of the holes. Five seeds of spinach seeds S (Fukubei) were sown in each piece of polyurethane foam as shown in Figure 12. Specifically, for the crisscross pattern (Example) and cross pattern (Comparative Example 1), five seeds S were placed in the center of the top surface of each polyurethane foam. For the perforated pattern (Comparative Example 2) and perforated + cross pattern (Comparative Example 3), five seeds S were placed in the holes of each polyurethane foam. The foams were covered loosely, and left to stand for six days under conditions of 22°C and 70-80% humidity to encourage rooting. After six days, liquid fertilizer was added, the lids were removed, and the foams were left to stand for another two days. After a total of eight days, the number of germinated seedlings was measured, and the germination rate was calculated.

[0065] [Table 1]

[0066] (2) Results The results are shown in Figure 13. In all cases using polyurethane foams A to C, the example with a cross-shaped pattern (eight slits radiating from the center) showed a higher germination rate compared to Comparative Examples 1 to 3.

[0067] Furthermore, observation of the root condition revealed that in Comparative Examples 2 and 3, which were perforated, the roots grew along the surface of the polyurethane foam. In Comparative Example 1, which was cross-shaped, the roots also grew along the surface of the polyurethane foam. On the other hand, in Example 1, which was shaped like a star (eight slits radiating from the center) and had a flat top surface, the roots grew towards the bottom of the polyurethane foam. From these results, it was found that the germination polyurethane foam according to this technology is particularly suitable for taprooted plants that extend their main root straight into the soil. [Explanation of Symbols]

[0068] 1. Polyurethane foam for germination 11 Top side 12. Base 13 slits 10 Polyurethane foam binder for germination 14 Side 101 Joint W Cultivation water P Pump S species

Claims

1. It has an upper surface for sowing seeds and a lower surface which is the opposite side of the upper surface, The upper surface is provided with five or more slits radiating from the center, The slit is a germination-promoting polyurethane foam that penetrates from the top surface to the bottom surface.

2. The germination polyurethane foam according to claim 1, wherein the upper surface is a flat surface.

3. The germination polyurethane foam according to claim 1, wherein the number of slits is 6 to 8.

4. The germination polyurethane foam according to claim 1, for use with taproot-type plants.

5. A germination polyurethane foam composite in which a plurality of germination polyurethane foams according to any one of claims 1 to 4 are bonded together in a manner that allows them to be separated from one another.

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