JP4680927B2 - Freshness preservation material for cut flowers - Google Patents

Description

  The present invention relates to a freshness-keeping material for cut flowers that does not spill even if it falls during transport or sale of cut flowers, and that can maintain a flowering state for a long period of time during transport, sale, and appreciation.

  In general, when selling cut flowers, they are often sold in a state where cut flowers are placed in a place where water is put on a plastic container. In this method, when the cut flower is taken out from the plastic container, water drops from the cut flower and wets the floor surface. Some dealers may refrain from getting the floor wet from the safety and hygiene aspects, and a sales method that can be handled dry is required.

  If the vase is sold with the cut flowers in the vase, the cut flowers will not be taken out, so there will be no water spillage. However, in the unlikely event that the vase falls, it cannot be said that it can be handled dry because water spills from the vase.

  As a method of handling in a dry manner, a gel-like composition containing gellan gum as a main ingredient is filled in a waterproof bag or container, and the gel-like composition is transported with the lower end of a cut flower stem inserted into the gel-like composition. Has been proposed (see Patent Document 1). However, in this gel composition, the gel composition is hard to insert when the lower end of the cut flower stem is inserted. Even if the gel composition is inserted, the contact between the lower end of the cracked stem and the gel composition is insufficient. Has a problem of insufficient supply.

In addition, a water supply material for cut flowers in which an appropriate amount of water-absorbing fibers is encapsulated as a water-absorbing material in a water-impermeable material has been proposed (see Patent Document 2). As the form of the water-absorbing fiber, it should be provided in a loosely entangled state such as cotton-like, felt-like, and the contact between the lower end of the stem and the water-absorbing fiber by using the cotton-like water-absorbing fiber. It is disclosed that the water supply to cut flowers is possible and that it has a freshness maintaining effect equivalent to that of water alone in two days. However, plant water conduits are extremely thin and clogged by bacteria and the like present in the water. The water-absorbing fiber used in this document has a weak gel strength, and a very small amount of very fine gel may fall off from the water-absorbing fiber, and the water conduit may be clogged. As compared with the case of water alone, it has a problem that it quickly wilts.
JP-A-7-82101 Japanese Patent Laid-Open No. 11-165767

  The present invention has been made in view of the above-described conventional problems, and the problem is that it eliminates water spillage during transport and sale of cut flowers, and is longer than the freshness-keeping material for cut flowers using conventional water absorbent fibers. An object of the present invention is to provide a freshness retaining material capable of retaining the freshness of cut flowers.

The present invention has the following configuration.
1. It contains water-absorbing fibers having a pure water absorption ratio of 10 to 100 times and a value obtained by dividing the pure water absorption ratio by the amount of salt-type carboxyl groups (mmol / g) in the range of 5 to 50. A freshness retaining material for cut flowers.
2. The freshness-keeping material for cut flowers according to 1, wherein the water-absorbent fibers are those in which a crosslinked structure by covalent bond is introduced.
3. The freshness-keeping material for cut flowers according to 1 or 2, wherein the water-absorbing fiber content is 30 to 100% by weight.

  By adopting the above-mentioned means, the water-absorbent fibers are gelled, so that the fluidity of water can be suppressed, water spillage during cut flower sales and transportation can be eliminated, and a long-term freshness maintaining effect can be obtained.

  Hereinafter, embodiments of the present invention will be described in detail. The water-absorbing fiber of the present invention refers to a fiber that absorbs and swells the fiber surface, the inside of the fiber, or the entire fiber when the water-absorbing fiber is immersed in pure water. A fiber that absorbs pure water having a weight of 10 to 100 times, preferably 30 to 70 times the weight of the water-absorbing fiber is suitably used. Since the water absorbed here is present inside the gel, it does not easily flow out. On the other hand, moderate water supply to the cut flower is performed from the portion in contact with the lower end of the stem of the cut flower. If the pure water absorption ratio is less than 10 times, water supply to cut flowers is insufficient, and the effect of maintaining freshness is not exhibited. Further, when the pure water absorption ratio exceeds 100 times, it is difficult to increase the gel strength.

Moreover, it is essential that the functional group of the gel part which a water absorbing fiber swells contains a salt type carboxyl group, and the value which remove | divided the pure water water absorption magnification | multiplying_factor with this salt type carboxyl group amount (mmol / g) is 5-50. It is essential to be in range. The value obtained by dividing the pure water absorption ratio by the salt-type carboxyl group amount is a numerical value that is a measure of gel strength. The lower this value, the stronger the gel strength, and the higher the value, the weaker the gel strength. If this value is less than 5, the gel strength is increased and the water absorption performance of the pure water is greatly reduced, and the water supply to the cut flowers becomes insufficient. On the other hand, if this value exceeds 50, the gel strength is weak and the freshness retention effect, which is thought to be due to clogging due to dropping off of the gel during use, is reduced.
The range of 5-50 is the optimal range which reduces the physical drop-off of a gel and enables water supply to a cut flower, and implement | achieves the freshness maintenance effect over a long period of time.

The method for measuring the water absorption ratio of the water-absorbing fiber used in the present invention is to immerse about 0.5 g of a sample in 300 ml of pure water at 25 ° C. for 30 minutes, and then perform centrifugal dehydration (160 G × 5 minutes, where G is the acceleration of gravity. ) To measure the weight of the prepared sample (Y ₁ (g)), and then measure the weight of the dried fiber (Y ₂ (g)) in the vacuum dryer at 80 ° C. until a constant weight is obtained. And calculated by the following equation.
Water absorption capacity of water absorption fiber (times) = (Y ₁ -Y ₂ ) / Y ₂

  The water-absorbing fiber is not limited as long as it satisfies the above-mentioned value obtained by dividing the pure water absorption capacity and the salt-type carboxyl group amount (mmol / g) by the pure water absorption capacity, but specifically, the surface of the acrylonitrile fiber. Water-absorbing layer having a salt-type carboxyl group on the surface, acrylonitrile-based water-absorbing fiber having a core-sheath structure with the acrylonitrile-based fiber part remaining in the center, and a crosslinked structure by covalent bonding to the water-absorbing fiber Crosslinked acrylonitrile-based water-absorbing fiber having a core-sheath structure introduced, a hydroxyl group-containing monomer capable of forming an ester crosslinked structure by reacting with a carboxylic acid group and a carboxylic acid group or a hydrophilic group-containing monomer such as an alkali metal base thereof. Polyacrylic acid-based crosslinked fiber and maleic anhydride-based crosslinked product obtained by copolymerization and introduction of an ester crosslinking bond It can be cited Wei, alginate-based crosslinked fibers.

  In order to produce a water-absorbing fiber having a value obtained by dividing the water absorption capacity of pure water by the salt-type carboxyl group amount (mmol / g), which is a measure of the water absorption capacity and gel strength required for the water-absorbing fiber of the present invention. It is desirable to introduce a crosslinked structure by covalent bond, and the above-mentioned crosslinked acrylonitrile-based water-absorbing fiber, polyacrylic acid-based crosslinked fiber, maleic anhydride-based crosslinked fiber, and alginic acid-based crosslinked fiber are desirable. . Among them, the cross-linked acrylonitrile water-absorbing fiber starting from acrylonitrile fiber has a high physical strength of the fiber because the acrylonitrile fiber part remains in the center, and the handling property at the time of processing is good. Since there is little change to a length direction, the dimensional stability of a product is favorable and it is more preferable.

  The introduction of the crosslinked structure by covalent bond in the crosslinked acrylonitrile-based water-absorbing fiber may be before the hydrolysis of the fiber surface described above, at the same time as the hydrolysis, or after the hydrolysis. Moreover, in introducing the crosslinked structure, the nitrile group of the acrylonitrile fiber or the carboxyl group generated by hydrolysis can be used. However, in the method using the carboxyl group generated by hydrolysis, the fiber is obtained by hydrolysis. The gel strength of the gel site formed on the surface is weak, and the gel falls off before the introduction of the covalently crosslinked structure, or some of the carboxyl group-containing polymer that does not undergo crosslinking flows out, whereas before hydrolysis Alternatively, if a nitrile group is used during the hydrolysis to introduce a cross-linked structure, the gel strength after hydrolysis is high, and the carboxyl group-containing polymer that does not undergo cross-linking decreases. Therefore, a method of introducing a crosslinked structure using a nitrile group is preferable.

  Hereinafter, a method for producing a crosslinked acrylonitrile-based water-absorbing fiber having a crosslinked structure introduced using a nitrile group will be described in detail. First, as the acrylonitrile polymer constituting the acrylonitrile fiber, a polymer containing acrylonitrile at 80% by weight or more, preferably 85% by weight or more is desirable. As copolymerizable monomers, vinyl halides and vinylidene halides such as vinyl chloride, vinyl bromide and vinylidene chloride; ethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid and itaconic acid and their salts: ( (Meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth) acrylate; vinyl esters such as vinyl acetate and vinyl propionate: vinyl sulfonic acid, (meth) allyl sulfone Examples include acids, ethylenically unsaturated sulfonic acids such as P-styrene sulfonic acid, and salts thereof; vinyl compounds such as (meth) acrylamide, vinylidene cyanide, and methacrylonitrile.

  Here, the molecular weight of the acrylonitrile-based polymer may be a molecular weight of a level that is used as a general clothing fiber, or may be a high molecular weight used for high-strength fibers, etc. Since it is more cost-effective to use, those having a weight average molecular weight of 200,000 or less can be suitably used.

  As for the fiber diameter, if the fiber is too thin, the gel is completely covered with the portion that comes into contact with the lower end of the cut flower stalk, resulting in a state close to clogging. A particle size of ˜100 μm, preferably 50˜80 μm is recommended. In addition, the cross-sectional shape of the fiber can be used without being limited to a circle, a flat shape, a triangle, and the like.

  Next, using the acrylonitrile fiber as a starting material, a crosslinked structure using a nitrile group is introduced, and the pure water absorption capacity and the salt type carboxyl group content (mmol / g) are used to divide the pure water absorption capacity. The method for obtaining a water-absorbing fiber having the above-mentioned value will be described in detail. This method includes a method of performing a hydrolysis treatment after a crosslinking treatment using a nitrile group and a method of simultaneously performing a crosslinking and hydrolysis using a nitrile group. Can be mentioned.

  First, a method for performing a hydrolysis treatment after a crosslinking treatment using a nitrile group will be described. As a method for introducing a crosslinked structure using a nitrile group into acrylonitrile fiber, a means of treating at a temperature of 50 to 120 ° C. for 5 to 150 minutes at a crosslinking agent concentration of 0.1 to 10.0% by weight is industrially preferable. Here, if the crosslinker concentration and processing temperature fall below the lower limit, the amount of covalently crosslinked structure introduced will be insufficient. Conversely, if the crosslinker concentration and treatment temperature exceed the upper limit, the amount of covalently crosslinked structure introduced will increase. In any case, it is difficult to obtain a water-absorbing fiber having a value obtained by dividing the water absorption ratio of pure water by the amount of salt-type carboxyl group after hydrolysis (mmol / g) within the scope of the present invention.

  The cross-linking agent is not particularly limited as long as it is a compound containing a polyfunctional compound having two or more functional groups in one molecule capable of chemically reacting with a nitrile group, for example, primary amino group, epoxy Examples include polyfunctional compounds having two or more functional groups of any one of functional groups such as hydrazine, specifically, hydrazine hydrate, hydrazine sulfate, hydrazine hydrochloride, hydrazine nitrate, hydrazine bromate, diaminoethane, carbonic acid. Examples thereof include guanidine, 1,3-diaminopropane, ethylene glycol diglycidyl ether and the like.

  In addition, means for filling the acrylonitrile fiber in a container equipped with a pump circulation system and introducing a cross-linked structure by advancing the reaction while circulating the aqueous solution of the cross-linking agent from the pump, such as safety, uniform reactivity, etc. Desirable from various points. A representative example of such a device (a container equipped with a pump circulation system) is an Overmeier dyeing machine.

  The means for hydrolyzing the crosslinked acrylonitrile fiber thus obtained is that the amount of pure alkaline metal compound is 2.5 to 10.0 (mmol / g) with respect to the dry weight of the alkaline metal compound or its aqueous solution. The fibers are preferably adjusted so as to be in the range of 5.0 to 10.0 (mmol / g), and the fibers are heated at a temperature of 80 ° C. or higher for 5 to 180 minutes, preferably 100 to 150. It is desirable to employ a means of heating for 10 to 120 minutes in a moist heat atmosphere at ℃.

  The alkaline metal compound used here refers to a substance having a pH of 7.5% or more of a 1.0% by weight aqueous solution of an alkali metal compound. Examples of such substances include alkali metal compounds such as Na, K, and Li. Examples thereof include hydroxides or alkali metal salts of organic acids such as carbonic acid, acetic acid and formic acid such as Na, K and Li. As a solvent for preparing an aqueous solution of an alkaline metal compound, water is industrially preferable, but a mixed solvent of water-miscible organic solvent such as alcohol, acetone, dimethylformamide and water may be used.

  Next, a method for simultaneously treating crosslinking and hydrolysis using a nitrile group will be described. An aqueous solution in which a crosslinking agent and an alkaline metal compound coexist has a pure alkaline metal compound amount of 2.5 to 10.0 (mmol / g), preferably 5.0 to 10 with respect to the dry weight of the fiber. The fibers are adjusted so that the cross-linking agent in the range of 0.0 (mmol / g) is 0.1 to 1.5% by weight, preferably 0.5 to 1.0% by weight. Then, it is desirable to employ a means for heating the fiber for 5 to 180 minutes at a temperature of 80 ° C. or higher, and preferably for 10 to 120 minutes in a humid heat atmosphere of 100 to 150 ° C.

  In this way, the pure water absorption ratio introducing a crosslinked structure using a nitrile group is 10 to 100 times, and the value obtained by dividing the pure water absorption ratio by the salt-type carboxyl group amount (mmol / g) is 5 to 50. It is possible to produce a crosslinked acrylonitrile-based water-absorbing fiber in the range of.

  The water-absorbing fiber of the present invention is preferably one having a covalently crosslinked structure introduced therein, but can also be produced without introducing a covalently crosslinked structure by using a high molecular weight polymer. is there. For example, using an acrylonitrile-based fiber composed of an acrylonitrile-based polymer having a weight average molecular weight exceeding 200,000, the surface is a water-absorbing part composed of a salt-type carboxyl group generated by hydrolysis by the above-mentioned hydrolysis treatment, and the center is acrylonitrile. An acrylonitrile-based water-absorbing fiber having a two-layer structure made of a base fiber can be produced.

  The content of the water-absorbing fiber when the freshness-keeping material is prepared using the water-absorbing fiber of the present invention described above is preferably 30 to 100% by weight. The higher the water-absorbing fiber content, the greater the amount of water retained per unit weight, the greater the amount of water supplied to the cut flowers, and not only can the water supply be carried out efficiently but also the freshness retaining material can be made compact. When the water-absorbing fiber content is 30% by weight or less, the amount of water absorption per unit weight is small, and it is necessary to make the freshness-keeping material very large in order to secure the amount of water supplied to the cut flowers, making practical handling difficult.

  The fiber used for mixing the water-absorbing fiber with other fibers is not particularly limited, but general-purpose fibers such as polyester, nylon, acrylic, polypropylene, polyethylene, vinylon, cotton, rayon, wool, glass fiber, etc. Is preferably used.

  Since the freshness-keeping material is used in a state swollen with water, the form before swelling is not particularly limited, and may be either cotton-like or sheet-like. In view of handling properties before swelling, a sheet form is preferable to a cotton form. Moreover, even if it is a sheet form, it is preferable that there are few entanglements between fibers as much as possible. If there is little entanglement, it will be flexible and amorphous when swollen as a whole, and it will be easy to insert the lower end of the stem, but if there is much entanglement, it will become harder overall when swollen, making it difficult to insert the lower end of the stem, The contact between the part and the water-absorbing fiber tends to be insufficient. Examples of the processing method of the sheet with less entanglement include a method of directly embossing the defibrated web, a method of passing the defibrated web through only the pre-punching step of the needle punching step, and the like.

  The water to be absorbed by the freshness-keeping material of the present invention may be distilled water or tap water alone, but an ethylene inhibitor such as silver thiosulfate complex or an antibacterial agent such as silver nitrate, aluminum sulfate, 8-hydroxyquinoline, sodium hypochlorite Alternatively, saccharides such as sucrose, glucose and fructose, surfactants such as alkylbenzene sulfonate and polyoxyethylene lauryl ether, or agents such as plant hormones such as gibberellin and benzylaminopurine are added singly or in combination. It is preferable to apply a commercially available pretreatment agent or a freshness-preserving agent containing such drugs.

  If the freshness-keeping material described so far is used, it becomes possible not only to transport and sell cut flowers without spilling water, but also to maintain freshness for a long period of time that could not be achieved with the prior art.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, the scope of the present invention is not limited only to these Examples. Parts and percentages in the examples are on a weight basis unless otherwise indicated.

The method for measuring the water absorption ratio of the water-absorbing fiber used in the present invention is to immerse about 0.5 g of a sample in 300 ml of pure water at 25 ° C. for 30 minutes, and then perform centrifugal dehydration (160 G × 5 minutes, where G is the acceleration of gravity. ) To measure the weight of the prepared sample (Y ₁ (g)), and then measure the weight of the dried fiber (Y ₂ (g)) in the vacuum dryer at 80 ° C. until a constant weight is obtained. And calculated by the following equation.
Water absorption capacity of water absorption fiber (times) = (Y ₁ -Y ₂ ) / Y ₂

The amount of water absorbed by the freshness-keeping material was measured by measuring the initial weight (W ₁ (g)) of the freshness-keeping material, immersed in 500 ml of water or a freshness-keeping agent for 30 minutes, and then transferred onto a 16-mesh wire net for 10 minutes. Drain the water and measure the weight (W ₂ (g)). The amount of water absorption of the freshness retaining material is calculated by the following formula.
Water retention amount (g) of freshness retaining material = W ₂ −W ₁

The salt-type carboxyl group amount (mmol / g) of the water-absorbent fiber is measured by first measuring the total carboxyl group amount in the water-absorbent fiber and then measuring the H-type carboxyl group amount and calculating according to the following formula.
Salt-type carboxyl group amount (mmol / g) = Total carboxyl group amount (mmol / g) −H-type carboxyl group amount (mmol / g)

The total amount of carboxyl groups was measured by immersing the water-absorbing fiber in a sulfuric acid aqueous solution having a pH of 2 to 3 for 30 minutes, thoroughly washing with water and drying with an 80 ° C. dryer, and then weighing about 0.4 g of a sample (X ₁ (g )), This is put into a solution obtained by dissolving 0.5 g of sodium chloride in 100 ml of pure water and stirred for 30 minutes. Subsequently, 30 ml of 0.1 mol / L NaOH was dropped, and after confirming that several drops of phenolphthalein were dropped and colored red, stirring was continued for 30 minutes. Thereafter, using a wire mesh, the water-absorbent fibers and the dispersion are separated to recover the dispersion. 0.1 mol / L HCl is added dropwise to the dispersion until the red color disappears (X ₂ (ml)). The total amount of carboxyl groups is calculated according to the following formula.
Total carboxyl group content (mmol / g) = (30−X ₂ ) × 0.1 / X ₁

The method for measuring the amount of H-type carboxyl groups is to weigh about 0.4 g of water-absorbing fiber (Z ₁ (g)), put it in a solution of 0.5 g of sodium chloride in 100 ml of pure water, and stir for 30 minutes. To do. Subsequently, 30 ml of 0.1 mol / L NaOH was dropped, and after confirming that several drops of phenolphthalein were dropped and colored red, stirring was continued for 30 minutes. Thereafter, using a wire mesh, the water-absorbent fibers and the dispersion are separated to recover the dispersion. 0.1 mol / L HCl is added dropwise to the dispersion until the red color disappears (Z ₂ (ml)). The amount of H-type carboxyl group is calculated according to the following formula.
H-type carboxyl group amount (mmol / g) = (30−Z ₂ ) × 0.1 / Z ₁

Preparation of acrylonitrile-based water-absorbing fiber A 35% sodium hydroxide aqueous solution is attached to the surface of acrylic fiber having a fineness of 6.6 dtex and fiber length of 51 mm, and the surface is salted by hydrolysis at 108 ° C for 15 minutes. An acrylonitrile-based water-absorbing fiber A having a core-sheath structure in which a water-absorbing layer having a carboxylic group and a acrylonitrile-based fiber portion at the center portion was left was prepared. This acrylonitrile-based water-absorbing fiber A had a pure water absorption ratio of 220 times, a salt-type carboxyl group amount of 2.75 mmol / g, and a value obtained by dividing the water absorption ratio by the salt-type carboxyl group amount was 80. In addition, the acrylonitrile type | system | group polymer of the weight average molecular weight 100,000 was used for manufacture of an acrylic fiber, and the acrylonitrile type | system | group polymer was also used for the acrylic fiber of the water absorbing fibers B, C, and D.

Preparation of crosslinked acrylonitrile-based water-absorbing fiber B The same acrylic fiber used in acrylonitrile-based water-absorbing fiber A is immersed in 1.0% hydrazine aqueous solution and then held at 85 ° C. for 40 minutes to introduce a crosslinked structure by covalent bonding. went. Thereafter, a 35% aqueous solution of sodium hydroxide is attached to the fiber surface in an amount equal to the weight of the crosslinked acrylic fiber, and hydrolyzed at 113 ° C. for 18 minutes, whereby a water-absorbing layer having a salt-type carboxyl group on the surface and an acrylonitrile fiber part in the center. A cross-linked acrylonitrile-based water-absorbing fiber B having a core-sheath structure with the remaining left was prepared. This crosslinked acrylonitrile-based water-absorbing fiber B had a pure water absorption ratio of 60 times, a salt-type carboxyl group amount of 4.3 mmol / g, and a value obtained by dividing the water absorption ratio by the salt-type carboxyl group amount was 14.0.

Preparation of cross-linked acrylonitrile-based water-absorbing fiber C The same acrylic fiber used for acrylonitrile-based water-absorbing fiber A is immersed in a 1.0% hydrazine aqueous solution and then held at 85 ° C. for 50 minutes to introduce a crosslinked structure by covalent bonding. went. Thereafter, a 35% aqueous solution of sodium hydroxide is attached to the fiber surface in an amount equal to the weight of the crosslinked acrylic fiber and hydrolyzed at 113 ° C. for 25 minutes to have a water-absorbing layer having a salt-type carboxyl group on the surface, and an acrylonitrile fiber part in the center. A cross-linked acrylonitrile-based water-absorbing fiber C having a core-sheath structure with the remaining left was prepared. This crosslinked acrylonitrile-based water-absorbing fiber C had a pure water absorption ratio of 35 times, a salt-type carboxyl group amount of 4.8 mmol / g, and a value obtained by dividing the pure water absorption ratio by the salt-type carboxyl group amount was 7.3. It was.

Preparation of crosslinked acrylonitrile-based water-absorbing fiber D After the same acrylic fiber used in acrylonitrile-based water-absorbing fiber A is immersed in a 2.0% hydrazine aqueous solution, it is held at 90 ° C. for 120 minutes to introduce a crosslinked structure by covalent bonding. went. Then, a 35% aqueous solution of sodium hydroxide is attached to the fiber surface in an amount equal to the weight of the cross-linked acrylic fiber, and hydrolyzed at 104 ° C. for 22 minutes to have a water-absorbing layer having a salt-type carboxyl group on the surface, and an acrylonitrile-based fiber part in the center. A cross-linked acrylonitrile-based water-absorbing fiber D having a core-sheath structure with the remaining left was prepared. The cross-linked acrylonitrile water-absorbing fiber D had a pure water absorption ratio of 9 times, a salt-type carboxyl group amount of 2.85 mmol / g, and a value obtained by dividing the pure water absorption ratio by the salt-type carboxyl group amount was 3.2. It was.

Example 1
After the crosslinked acrylonitrile-based water-absorbing fiber B and cotton were mixed at a weight ratio of 60/40, a defibrating web was formed by a card defibrating machine and directly embossed to prepare a freshness maintaining material having a basis weight of 220 g / m ² . Cut this freshness-keeping material to 10cm x 10cm size, immerse it in Misaki (made by Otsuka Chemical), a freshness-keeping agent for cut flowers, for 30 minutes, transfer to a 16-mesh sieve and leave for 10 minutes to drain off excess water. And made a state without water spills. The weight was measured after draining, and the value obtained by subtracting the weight before immersion was defined as the water retention amount. Table 1 shows the results of evaluating the water retention and sheet handling properties. The sheet handling property is determined by determining whether or not the size can be handled as a sheet volume when three roses are transported and sold.

  The freshness-holding material after water absorption by the freshness-keeping agent was put in a bag and stabbed until the lower end of the stem entered the freshness-keeping material after weighing three roses (variety: rotellose) cut to 40 cm. Thereafter, the whole was wrapped in a sleeve and placed in a cup so as not to fall down, and left for 3 days. This state assumes a state at the time of transportation or sales, and this period is called a storage period. Thereafter, the roses were taken out from the freshness-keeping material, cut back, and then replaced in a vase containing Misaki and left for 5 days. This state assumes a state at the time of viewing, and this period is referred to as a viewing period. Table 2 shows the weight change rate and flowering state of roses during the storage period and the appreciation period. The weight change rate is a percentage change in weight with respect to the weight of the rose at the start of the test.

Example 2
Table 1 shows the results of carrying out the same test as in Example 1 except that the crosslinked acrylonitrile-based water-absorbing fiber B in Example 1 was changed to the crosslinked acrylonitrile-based water-absorbing fiber C and the freshness retaining material size was changed to 12 cm × 12 cm. 2 shows.

Example 3
Results of performing the same test as in Example 1 except that the freshness-holding material configuration in Example 1 was changed to crosslinked acrylonitrile-based water-absorbing fiber C / cotton = 80/20 and the freshness-holding material size was changed to 12 cm × 12 cm. Are shown in Tables 1 and 2.

Example 4
Results of performing the same test as in Example 1 except that the freshness-holding material configuration in Example 1 was changed to crosslinked acrylonitrile-based water-absorbing fiber C / cotton = 20/80, and the freshness-holding material size was changed to 23 cm × 23 cm. Are shown in Tables 1 and 2.

Comparative Example 1
Tables 1 and 2 show the results when the same operation as in Example 1 was performed except that the crosslinked acrylonitrile-based water absorbent fiber B in Example 1 was changed to the acrylonitrile-based water absorbent fiber A.

Comparative Example 2
The results when the same operation as in Example 1 was performed except that the crosslinked acrylonitrile-based water absorbent fiber B in Example 1 was changed to the crosslinked acrylonitrile-based water absorbent fiber D and the freshness retaining material size was changed to 45 cm × 45 cm. Shown in Tables 1 and 2.

  In Examples 2 and 3, the water is sufficiently retained in a state without water spilling, and an appropriate amount of water is supplied to the roses. After a storage period of 3 days, the flowering state continues for a long period of 5 days after the viewing period. Is maintained. The size of the freshness-keeping material is also suitable for transportability and handling when assuming sales use. Example 1, which has a relatively high value obtained by dividing the pure water absorption ratio by the amount of salt-type carboxyl groups, caused a decrease in water-raising property, and the progress of weight reduction was slightly faster, and one was close to the vent neck after 5 days of the viewing period. Although it is in a state, a long-term freshness maintaining effect is recognized. In Example 4, since the water-absorbing fiber content in the freshness-keeping material is small, the size is increased in order to secure the water retention amount, which is slightly inferior in handling property compared to Examples 1 to 3, but is sufficiently practical. .

  The value obtained by dividing the pure water absorption ratio by the salt-type carboxyl group amount, that is, Comparative Example 1 having low gel strength, is all bent-necked after 5 days of the viewing period. In Comparative Example 2, the water absorption capacity of the water-absorbing fiber is low, so that the water retention amount is very large and the handleability is not only bad, but also the handling property is poor. Water supply to the cut flowers became difficult, regardless of the gel strength, the water deficit caused the dwarfing without flowering and withered after 5 days of the appreciation period.

Example 5
Cross-linked acrylonitrile-based water-absorbing fiber B and cotton are mixed at a weight ratio of 50/50, and then a spread web (approx. 200 g / m ² ) is made with a card weaving machine. An embossed sheet was obtained. This embossed sheet was cut into 10 × 10 cm, and the water retention amount was measured. The water retention amount was 191 ml, there was no water spillage, and the handleability was good. Place the embossed sheet for cut water supply in water holding state into a round bottom container with a diameter of 6 cm and a height of 15 cm, and stand three roses (yellow top sun) trimmed to 40 cm with the cut end stuck in the water retaining state embossed sheet. In that state, it was left for 3 days (storage period). After that, it was replaced with a vase containing water and left for 7 days (viewing period). Table 3 shows the weight change (g) and appearance of the three roses during the storage period and the appreciation period.

Comparative Example 3
In Example 5, instead of using the embossed sheet in the storage state during the storage period, the same operation as in Example 1 was performed except that the water was changed to 200 ml. The results are also shown in Table 3.

Comparative Example 4
The same operation as in Example 5 was performed except that the embossed sheet configuration in Example 5 was changed from the crosslinked acrylonitrile-based water-absorbing fiber B to the acrylonitrile-based water-absorbing fiber A. The results are also shown in Table 3.

Claims (3)

  It contains a water-absorbing fiber having a pure water absorption ratio of 10 to 100 times and a value obtained by dividing the pure water absorption ratio by the salt-type carboxyl group amount (mmol / g) in the range of 5 to 50. Freshness retaining material for cut flowers.   The freshness-keeping material for cut flowers according to claim 1, wherein the water-absorbent fibers are those in which a crosslinked structure by covalent bond is introduced.   The freshness-keeping material for cut flowers according to claim 1 or 2, wherein the water-absorbing fiber content is 30 to 100% by weight.