JP2010207469A - Pedestal for flower arrangement, and method for manufacturing thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To easily provide a pedestal for flower arrangement which is biodegradable and excellent in insertion property and holding property of a flower, and also excellent in light weight and water absorbency. <P>SOLUTION: The pedestal for flower arrangement is formed of aliphatic polyester-based resin, wherein a continuous air bubble rate is ≥50%, and melting calorie is 15-60J/g in a DSC curve obtained when raising temperature from 0°C to 200°C by 10°C/min in differential scanning calorimetry. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a lightweight flower arrangement pedestal that is unlikely to adversely affect the environment and a method for manufacturing the same.

  The flower arrangement pedestal is required to retain water or absorb water so that the florets are fixed at a desired position and the fresh flowers do not die. In order to insert and fix the florets and to exhibit water retention and water absorption, those having a cell structure in the resin are suitable.

  From such a point of view, the use of a foam molded article as a pedestal for flower arrangement has been studied. In general, the cell structure of a foamed molded product is a closed cell structure in which one cell is surrounded by a resin wall and independent from each other, and there is no resin wall that completely surrounds one cell. It is divided into open cell structures. Among them, an open-cell foamed molded body has water permeability, water absorption, and air permeability from its structure, and is therefore widely used as a filter medium, a water absorbent, an adsorbent, and the like.

  For example, Patent Document 1 discloses an open-cell foamed molded article of phenol resin, which is made of a so-called phenol foam, and is used as a pedestal for flower arrangement after water absorption. Such phenolic foam bases are lightweight, have a high degree of freedom of processing and expression, and can be used easily. However, since phenolic foam is a thermosetting resin, it cannot be recycled (recycled). When discarded, it may produce bisphenol, which is suspected of being an environmental hormone.

  Patent Document 2 discloses a foam that is biodegradable by adding a biodegradable component as a subcomponent to a phenol foam component. However, even such biologically degradable foams do not solve the problem of environmental hormones as long as they contain a phenol component, and conversely, decomposition causes diffusion of the phenol component into the soil. There is a concern that will be promoted.

  From the above, application of biodegradable resins that are less likely to adversely affect the environment has been studied for foamed molded articles having an open-cell structure. For example, in Patent Document 3, an open-cell body mainly composed of cellulose acetate is prepared and used. (TSH); P, P'-oxybisbenzenesulfonylhydrazine (OBSH); sodium hydrogen carbonate; volatile substances such as pentane; water etc. " Only the method of throwing it into water is used. By such a method, a uniform foam cannot be obtained, and it is estimated that it is difficult to obtain a foam having a low density as described in Patent Document 3.

  On the other hand, since a crystalline foamed molded article generally has brittleness, it can be suitably used as a flower arrangement pedestal excellent in floret insertion and retention by adjusting its crystallinity appropriately. there is a possibility. For example, it is a polylactic acid resin foam molded article obtained by in-mold foam molding of polylactic acid resin foamed particles in Patent Document 4, wherein the crystalline dimensional change rate at 150 ° C. is less than 5%. A polylactic acid resin foamed molded article is disclosed. In general, a polylactic acid resin foamed molded article has excellent heat resistance compared to an amorphous polylactic acid resin foamed molded article because of its high degree of crystallinity, but crystalline foamed polylactic acid is inferior in foamability. It is difficult to obtain a foamed molded article having a low density using the pre-expanded resin particles. Moreover, since the open cell ratio is also low, it is difficult to say that it has sufficient water absorption.

  Patent Document 5 discloses a flower arrangement pedestal excluding a foam skin layer extruded using polycaprolactone, cellulose acetate, modified starch, polylactic acid, or the like. There is no mention of crystallinity.

  As described above, development of a flower arrangement pedestal that is biodegradable, excellent in flower bud insertion and retention, lightweight, and excellent in water absorption is demanded.

Japanese Patent Laid-Open No. 9-75193 JP-A-8-53564 JP 2000-333802 A JP 2007-100025 A JP 2000-217683 A

  An object of the present invention is to easily provide a flower arrangement pedestal that is biodegradable, excellent in flower bud insertion and retention, lightweight, and excellent in water absorption.

As a result of intensive studies, the present inventors obtain a crystalline aliphatic polyester resin foamed molded article having a high expansion ratio and a high open cell ratio while using an amorphous aliphatic polyester resin as a raw material. In addition, the present inventors have found that the crystalline aliphatic polyester-based resin foamed molded article is excellent in floret insertion and holding properties that can be suitably used as a pedestal for flower arrangement, and have completed the present invention.

  That is, the first of the present invention is made of an aliphatic polyester resin, has an open cell ratio of 50% or more, and is obtained when the temperature is raised from 0 ° C. to 200 ° C. at 10 ° C./min in differential scanning calorimetry. It is related with the base for flower arrangement whose heat of fusion is 15 J / g or more and 60 J / g or less in a DSC curve.

As a preferred embodiment,
(1) The apparent density is 0.014 g / cm ³ or more and 0.038 g / cm ³ or less,
(2) The aliphatic polyester resin is a polylactic acid resin,
The pedestal for flower arrangement described above.

  The second aspect of the present invention relates to the above-mentioned method for producing a flower arrangement pedestal characterized in that it is obtained by hydrolyzing a foamed molded article having an amorphous aliphatic polyester resin as a base resin. Relates to a method for producing a pedestal for flower arrangement as described above, wherein the hydrolysis is carried out under temperature and humidity conditions of a temperature of 60 ° C. or more and 100 ° C. or less and a relative humidity of 60% or more.

  Since the pedestal for flower arrangement of the present invention is biodegradable, it is less likely to adversely affect the environment even after decomposition. Moreover, since the density is small, it is lightweight and has a high open cell ratio, so water absorption can be expected. Moreover, since it has moderate brittleness, it is excellent in floret insertion and retention.

  The pedestal for flower arrangement of the present invention is made of an aliphatic polyester resin. The aliphatic polyester resin used in the present invention refers to an aliphatic polyester as a main component (50% by weight or more). For example, a polylactic acid resin including polylactic acid as a main component, poly-3- (hydroxy Butyrate), poly-3- (hydroxybutyrate-covalerate), poly-3- (hydroxybutyrate-cohexanoate) and other hydroxy acid polycondensates, and ring-opening polymers of lactones such as polycaprolactone And polycondensates of aliphatic polyhydric alcohols such as polybutylene succinate, polybutylene adipate, polybutylene succinate adipate, poly (butylene adipate / terephthalate) and aliphatic carboxylic acid, etc., selected from these groups Can be used.

  In addition, two or more aliphatic polyester resins can be mixed and used, and, as long as the effects of the present invention are not impaired, other resins are added to the aliphatic polyester resin to form a base resin. I can do things. The base resin preferably contains 50% by weight or more of an aliphatic polyester resin, more preferably 70% by weight or more, and still more preferably 90% by weight or more. Examples of the other resins include polyethylene resins, polypropylene resins, polystyrene resins, polyester resins, acrylic resins, and vinyl resins.

  Among these, in order to obtain the effects of the present invention, as the aliphatic polyester-based resin, a polylactic acid-based resin or a hydroxy acid polycondensate is preferable, and a polylactic acid-based resin is particularly preferable from the viewpoint of environmental friendliness.

  The polylactic acid-based resin is not particularly limited, but it is preferable that the main component is polylactic acid whose isomer ratio of the lactic acid component is 5% or more, preferably 8% or more. If it is the said range, since polylactic acid is amorphous, since there exists a tendency which a low density foam is easy to obtain from the point of foamability and a moldability, it is preferable.

  The polylactic acid resin that can be used in the present invention is preferably subjected to a thickening treatment from the viewpoints of foamability and moldability. As the thickening treatment, a method of thickening the polylactic acid resin to a viscosity region suitable for foaming by the thickening treatment can be used, and various conventionally known methods such as polyisocyanate compounds, peroxides, acid anhydrides, A method using a general cross-linking agent such as an epoxy compound, a silane cross-linking method, and an electron beam cross-linking method can be used if only the surface layer is sufficient, but a method using a cross-linking agent is preferred from the viewpoint of ease of implementation including cost.

  As the polyisocyanate compound, aromatic polyisocyanate, alicyclic polyisocyanate, aliphatic polyisocyanate, and the like can be used. An isocyanate compound is mentioned. Examples of the alicyclic polyisocyanate include polyisocyanate compounds having isophorone and diphenylmethane hydroxide as a skeleton, and examples of the aliphatic polyisocyanate include polyisocyanate compounds having hexamethylene and lysine as a skeleton.

  Examples of the peroxide include benzoyl peroxide, bis (butylperoxy) trimethylcyclohexane, bis (butylperoxy) cyclododecane, butylbis (butylperoxy) valerate, dicumyl peroxide, butylperoxybenzoate, and dibutyl peroxide. And organic peroxides such as bis (butylperoxy) diisopropylbenzene, dimethyldi (butylperoxy) hexane, dimethyldi (butylperoxy) hexyne, and butylperoxycumene.

  Examples of the acid anhydride include trimellitic anhydride, pyromellitic anhydride, ethylene-maleic anhydride copolymer, methyl vinyl ether-maleic anhydride copolymer, styrene-maleic anhydride copolymer, and the like.

  Examples of the epoxy compound include glycidyl methacrylate-methyl methacrylate copolymer, glycidyl methacrylate-styrene copolymer, glycidyl methacrylate-styrene-butyl acrylate copolymer, polyethylene glycol diglycidyl ether, trimethylolpropane polyglycidyl ether, coconut fatty acid glycidyl. Examples thereof include various glycidyl ethers such as esters, epoxidized soybean oil, and epoxidized linseed oil, and various glycidyl esters.

  Of these crosslinking agents, polyisocyanate compounds are preferably used. The reason is that if a polyisocyanate compound is used, torque increase due to cross-linking and thickening during kneading is small, and post-thickening due to urea bond, urethane bond, allophanate bond, etc. is possible by heating in the presence of moisture after kneading. It is. Among the polyisocyanate compounds, it is preferable to use a polyisocyanate compound having a tolylene or diphenylmethane skeleton, particularly a polyisocyanate of diphenylmethane, from the viewpoints of versatility, handleability, weather resistance, and the like.

  The addition amount of the crosslinking agent can be adjusted and determined for each crosslinking agent so as to obtain desired melting characteristics. The amount varies depending on the kind of the crosslinking agent and the amount of the functional group, but is generally preferably 0.1 parts by weight or more and 6.0 parts by weight or less, more preferably 0.2 parts by weight with respect to 100 parts by weight of the polylactic acid resin. The amount is from 0.5 parts by weight to 5.0 parts by weight, more preferably from 0.5 parts by weight to 4.0 parts by weight.

  For example, when an aromatic polyisocyanate compound having 2 to 3 functional groups is used for polylactic acid having a weight average molecular weight of about 200,000 and a polydispersity of about 2 to 2.5, the content of the polylactic acid is 0.1 to 5 parts by weight is preferable with respect to 100 parts by weight of the resin, more preferably 0.2 to 4 parts by weight, and still more preferably 1.5 to 3.5 parts by weight. is there.

  The flower arrangement pedestal of the present invention has a curve (hereinafter referred to as DSC) obtained when the temperature is raised from 0 ° C. to 200 ° C. at a rate of 10 ° C./min in differential scanning calorimetry (hereinafter sometimes referred to as DSC measurement). In some cases, the heat of fusion is 15 J / g or more and 60 J / g or less. Preferably they are 15 J / g or more and 55 J / g or less, More preferably, they are 15 J / g or more and 50 J / g or less. If it is the said range, it is excellent in the insertion property and holding | maintenance property of a flower bud.

  The open cell ratio of the pedestal for flower arrangement of the present invention is 50% or more, preferably 55% or more and 100% or less, more preferably 60% or more and 100% or less. Within the range of the open cell ratio, a flower arrangement pedestal having excellent water absorption can be obtained. The flower arrangement pedestal of the present invention can be obtained by hydrolyzing a foamed molded article having an amorphous aliphatic polyester-based resin as a base resin. The flower arrangement pedestal has a low density and a high open cell ratio. It is preferable because it can be easily obtained. Here, the amorphous aliphatic polyester resin refers to an aliphatic polyester resin having a heat of fusion of less than 15 J / g.

A foamed molded article using an amorphous aliphatic polyester-based resin as a base resin is typically obtained as follows.
(1) A bead-method in-mold foam molding method in which an amorphous aliphatic polyester resin is used as foam particles, and the foam particles are foam-molded in the mold.
(2) An extrusion foaming method in which an amorphous aliphatic polyester resin is melted and kneaded in an extruder together with a foaming agent and extruded into a plate shape.

Furthermore, for the bead method in-mold foam molding method,
(A) A method of impregnating an amorphous aliphatic polyester resin having a particle shape with a foaming agent to form an aliphatic polyester resin foamable particle, and heating and foaming the aliphatic polyester resin foamable particle to obtain a foamed particle;
(B) a method of impregnating an amorphous aliphatic polyester resin in the form of particles in a pressure-resistant container with a foaming agent and releasing the foamed particles in a low-pressure atmosphere;
(C) A method of melt-kneading an amorphous aliphatic polyester resin together with a foaming agent in an extruder and extruding, foaming or cutting into a foamed particle shape after completion of foaming,
(D) Amorphous aliphatic polyester-based resin is melt-kneaded in an extruder together with a foaming agent, and cut into a particle shape while extruding without foaming to obtain aliphatic polyester-based resin foamable particles. A method of heating and foaming a resin-based foamable particle to form a foamed particle,
And the like.

  There are no particular limitations on the foaming agent that can be used in the production of the foamed molded article, and conventionally known ones can be used. Propane, isobutane, normal butane, isohexane, normal hexane, cyclobutane, cyclohexane, isopentane, normal pentane, cyclohexane Hydrocarbon blowing agents such as pentane, halogenated hydrocarbon blowing agents such as methyl chloride, methylene chloride and dichlorodifluoromethane, ether blowing agents such as dimethyl ether and methyl ethyl ether, nitrogen, carbon dioxide, argon, air, etc. And at least one selected from these groups can be used.

  In the case of producing a foam molded article by the bead method in-mold foam molding method, there is little gas dissipation with respect to the aliphatic polyester-based resin, and foamable particles can be transported, and the desired foamability can be obtained. 6 hydrocarbon blowing agents are preferred. The impregnation amount of the foaming agent may be adjusted depending on the type of foaming agent and the desired foaming ratio. For example, in order to obtain foamed particles having a foaming ratio of 30 times or more, the base resin 100 constituting the foamable particles 4 parts by weight or more is preferable with respect to parts by weight.

  For example, a colored pigment or dye such as black, gray, brown, blue, or green may be added to the aliphatic polyester resin. If a colored base resin is used, a colored foamed molded product can be obtained. Examples of the color pigment or dye include organic and inorganic pigments and dyes. Conventionally known pigments and dyes can be used.

  The amount of the color pigment or dye added varies depending on the color of the color, but is usually preferably 0.001 part by weight or more and 5 parts by weight or less, and 0.02 part by weight or more with respect to 100 parts by weight of the aliphatic polyester resin. More preferably, it is 3 parts by weight or less.

  Moreover, as a bubble regulator, inorganic substances, such as talc, calcium carbonate, borax, zinc borate, aluminum hydroxide, calcium stearate, can be added in advance. In addition, additives such as a flame retardant, an antistatic agent, and a weathering agent may be added to the aliphatic polyester resin as long as the effects of the present invention are not impaired.

  When adding additives such as color pigments, dyes, or inorganic substances to the aliphatic polyester-based resin that is the base resin, the additives can be kneaded into the base resin as they are, but usually considering dispersibility and the like. It is preferable to make a master batch of the additive and knead it with the base resin.

  When the flower arrangement pedestal comprising the crystalline aliphatic polyester-based foamed molded article having a high open cell ratio according to the present invention is produced by the bead method in-mold foam molding method, it is preferably produced as follows.

  First, an amorphous aliphatic polyester resin foamable particle is produced, and then the foamable resin particle is foamed to obtain an amorphous aliphatic polyester resin foam particle, followed by curing (relaxation of internal and external pressure difference). Then, in-mold foam molding is performed to obtain an amorphous aliphatic polyester resin in-mold foam molding. If the secondary foaming power during in-mold foam molding is poor, in addition to the pressure filling and compression filling methods used in general in-mold foam molding, inorganic gases such as air, nitrogen and carbon dioxide are amorphous. After imparting to the aliphatic polyester resin expanded particles, they may be subjected to in-mold expansion molding.

  The weight average molecular weight of the aliphatic polyester of the amorphous aliphatic polyester-based resin foam molded article of the present invention is preferably 150,000 or more and 400,000 or less. However, if the weight average molecular weight is less than 150,000 at the stage of foamable particles or foamed particles, sufficient melt tension cannot be obtained in preliminary foaming or in-mold foam molding, and foamable particles with good moldability and good appearance are obtained. There is a tendency that a foam molded article cannot be obtained. For this reason, as shown below, after first producing amorphous aliphatic polyester resin foamed particles using the amorphous aliphatic polyester resin composition based on the above formulation, the aliphatic polyester resin foamed particles Is molded into a foamed molded product having a weight average molecular weight of 150,000 or more and 400,000 or less at a desired magnification, and then the foamed molded product is hydrolyzed under an appropriate temperature and humidity condition to obtain a crystalline aliphatic having a high open cell ratio. It is preferable to use a polyester resin foam molded article.

  Here, a description will be given by taking as an example a foam molded body produced by a bead method in-mold foam molding method using a polylactic acid resin as a base resin.

  In the present invention, in order to preferably produce amorphous polylactic acid resin expanded particles, first, amorphous polylactic acid resin particles are prepared. The amorphous polylactic acid-based resin particles can be produced by a conventionally known method. For example, after the amorphous polylactic acid-based resin and a crosslinking agent, and if necessary, other additives are melt-kneaded with an extruder, It can be obtained by extrusion cutting with a cutter or a strand cutter. The weight per amorphous polylactic acid-based resin particle is preferably 0.05 to 10 mg, more preferably 0.1 to 4 mg. When the particle weight is in the above range, the productivity of the resin particles is good and the filling property at the time of in-mold foam molding tends to be good.

  The melt viscosity of the amorphous polylactic acid resin is preferably 0.1 g / 10 min or more and 10 g / 10 min or less as a melt index (MI) value based on JIS K 7210 (load 2.16 kg). If the MI value is within this range, it tends to be easy to obtain a foamed molded article having excellent productivity and a high foaming ratio, and the objects and effects of the present invention are easily exhibited.

  Next, the amorphous polylactic acid resin particles are impregnated with a foaming agent to obtain amorphous polylactic acid resin foamable particles. The method for impregnating the amorphous polylactic acid resin particles with the foaming agent is not particularly limited as long as sufficient pressure is applied in the presence of the foaming agent capable of obtaining the desired foamability. . For example, it is possible to impregnate a resin particle with a foaming agent by placing an aqueous medium or a non-aqueous medium in an airtight container, adding resin particles and a foaming agent thereto, and stirring at an appropriate temperature and time. is there. When the impregnation is performed with an aqueous medium, it is preferable that the resin composition is easily subjected to a hydrolysis reaction, so that the impregnation is completed in a short time or a device for suppressing hydrolysis.

  In the impregnation with the foaming agent, an impregnation aid, a dispersing agent or the like may be used in order to obtain stable impregnation properties and foamability. Examples of the impregnation aid include proton solvents such as methanol, ethanol and propanol, ketones such as acetone and methyl ethyl ketone, esters such as ethyl acetate, butyl acetate and normal propyl acetate, toluene and xylene. Examples include aprotic solvents such as aromatic hydrocarbons, etc., but when impregnating with an aqueous medium, using an aprotic solvent does not promote hydrolysis of the polylactic acid resin, preferable. Examples of the dispersant include a cationic surfactant, an anionic surfactant, and a nonionic surfactant. In the case of impregnation with an aqueous medium, monovalent metal salts such as sodium chloride, sodium sulfate, sodium carbonate, potassium chloride, potassium sulfate, potassium carbonate, and chloride are used for the purpose of suppressing water penetration into the resin particles. It is preferable to add water-soluble salts such as divalent metal salts such as magnesium and magnesium sulfate, and trivalent metal salts such as aluminum sulfate. The amount of water-soluble salts added for the purpose of suppressing water penetration into the resin particles is preferably 5 parts by weight or more and 20 parts by weight or less, and 7.5 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of water. More preferred are parts by weight or less. When the amount is less than 5 parts by weight, the foaming agent may not be sufficiently impregnated, and when the amount is more than 20 parts by weight, the foaming agent may be difficult to enter.

  In the above, or in order to obtain amorphous polylactic acid resin expandable particles, using an extruder, amorphous polylactic acid resin and a crosslinking agent, if necessary, other additives are introduced into the extruder, Then, after adding a foaming agent and melt-kneading, the kneaded product can be extruded, and the extruded kneaded product can be cut to obtain expandable particles.

  Next, the amorphous polylactic acid resin foamable particles obtained as described above can be foamed to obtain amorphous polylactic acid resin foamed particles. As such a method, for example, a method of heating and foaming amorphous polylactic acid-based resin expandable particles with steam, hot air, high frequency, or the like can be mentioned, which is the simplest method.

  As another method, the resin particles are dispersed in a dispersion medium in the presence of a foaming agent in a sealed container, and the contents are heated to soften the resin particles and impregnate the foaming agent in the particles. Next, one end of the container is opened, and the resin particles and the dispersion medium are simultaneously released into an atmosphere (usually under atmospheric pressure) lower than the inside of the container while maintaining the pressure inside the container at a pressure higher than the vapor pressure of the blowing agent. Examples of the foaming method include foaming.

  In addition, the base resin, the crosslinking agent, and other additives are melted with an extruder, kneaded with a foaming agent to form a foamable melt-kneaded product, then extruded into a strand shape and foamed, and after cooling to an appropriate length. Examples thereof include a method of producing expanded particles by cutting or cooling the strands to an appropriate length and then cooling.

  Among these, the method of heating and foaming amorphous polylactic acid-based resin foamable particles by steam, hot air, high frequency, etc. from the viewpoint that transportation of foamable particles is advantageous in terms of cost and that foamable particles can be transported. Is preferred.

Preferably 0.014 g / cm ³ or more 0.038 g / cm ³ or less as the bulk density of the amorphous polylactic acid resin foamed particles obtained as described above, 0.016 g / cm ³ or more 0.038 g / cm ^3, more preferably less, more preferably 0.018 g / cm ³ or more 0.038 g / cm ³ or less. If the foamed particles are within the above range, it tends to be a pedestal for flower arrangement made of a crystalline polylactic acid resin foamed molded article having a light weight and high open cell ratio. In addition, the bulk density of the amorphous polylactic acid-based resin expanded particles was measured in accordance with JIS K6911, and the bulk density of the amorphous polylactic acid-based resin expanded particles was calculated based on the following formula.
Bulk density of polylactic acid-based resin expanded particles (g / cm ³ ) = [mass cylinder weight (g) -mass cylinder mass (g)] / [volume of the graduated cylinder (cm ³ )]

  Amorphous polylactic acid resin foamed particles are obtained by molding the amorphous polylactic acid resin foamed particles in-mold. In-mold foam molding can use a molding machine usually used for molding polystyrene foam and a molding machine used for molding polyolefin resin foam particles, usually with a vapor pressure of 0.03 to 0.3 MPa (G), preferably It carries out at 0.05-0.20 MPa (G). When the secondary foaming power at the time of molding is poor, in addition to the pressure filling and compression filling methods used for general in-mold foaming, inorganic gases such as air, nitrogen, carbon dioxide, etc. You may give to resin foaming particle. Further, in order to improve the fusion property between the foam particles inside the foam molded article, steam and air may be mixed, and in-mold foam molding may be performed using steam having a low heat capacity.

  It is preferable to obtain the flower arrangement pedestal of the present invention by hydrolyzing a foam-molded product using the amorphous aliphatic polyester resin obtained as described above as a base resin.

  The hydrolysis method and conditions are not particularly limited as long as the hydrolysis proceeds uniformly, but the treatment in the soil is extremely long in hydrolysis time and is difficult to cause uniform hydrolysis. From the viewpoints of hydrolyzing with water vapor or constant temperature and humidity machine with high penetrating power for the foamed molded product having a basic aliphatic polyester-based resin as the base resin, uniformity of treatment, and ease of control, A method using a constant temperature and humidity machine is more preferable.

  When hydrolysis is performed using a thermostatic oven, a foamed molded article having an amorphous aliphatic polyester resin as a base resin is preferably 60 ° C. or higher and 100 ° C. or lower and a relative humidity of 60% or higher, more preferably 60 Preferably from 3 to 48 hours, more preferably from 60 to 100%, relative humidity from 60 to 95%, more preferably from 60 to 95 ° C, and relative humidity from 60% to 100%. By treating for 4 hours or more and 24 hours or less, it is possible to obtain a flower arrangement pedestal having a high open cell ratio and excellent floret insertion and retention.

  Although the temperature may exceed 100 ° C, it is usually performed at a temperature of 100 ° C or lower because pressure resistance equipment is required or the processing speed is too high and the crystallinity may be difficult to control. preferable. The treatment conditions may be appropriately adjusted depending on the density of the flower arrangement base to be obtained and the desired crystallinity. Moreover, in order to shorten a hydrolysis time, you may mix a trace amount alkali component and hydrolyze with an alkali vapor | steam.

Apparent density of the resulting flower arrangement holder is preferably not more than 0.014 g / cm ³ or more 0.038 g / cm ^3, not more than 0.016 g / cm ³ or more 0.038 g / cm ³ more preferably, it is more preferably not more than 0.018 g / cm ³ or more 0.038 g / cm ^3. The apparent density is a value obtained by dividing the weight of the flower arrangement pedestal by the volume of the flower arrangement pedestal.

  The 25% compressive strength of the flower arrangement pedestal of the present invention is preferably 0.050 MPa or more and 0.15 MPa or less. When the compressive strength is within the above range, the floret insertion and retention are good.

  The weight average molecular weight of the aliphatic polyester-based resin of the pedestal for flower arrangement of the present invention is preferably 8000 or more and 120,000 or less. When the molecular weight is in the above range, desired heat resistance, compressive stress, and compressive elastic modulus tend to be ensured.

  Hereinafter, although the base for flower arrangements of this invention is demonstrated in detail by a specific Example, this invention is not limited only to this Example. Unless otherwise specified, “part” and “%” are based on weight.

<Differential scanning calorimetry>
The obtained flower arrangement base was cut with a razor or the like and weighed about 5 mg. The obtained sample was heated by a differential scanning calorimeter (Seiko Instruments Co., Ltd.) from 0 ° C. to 200 ° C. at a heating rate of 10 ° C./min, and the heat of fusion (J / g) was measured. The amount of heat of fusion is the amount of heat at the melting peak appearing in the DSC curve, connecting the baseline before the start of melting and the baseline after the end of melting with a straight line and surrounded by the straight line and the curve.

<Open cell ratio>
The obtained flower arrangement pedestal was measured according to ASTM D-2856 using a multi-pycnometer (manufactured by Beckman Japan Co., Ltd.). The open cell ratio is a measure of water absorption.

<25% compressive strength>
For the flower arrangement pedestals obtained in Examples 1, 2, 4, 5 and Comparative Examples 1 and 2, using a tensile and compression tester (TG-20kN, manufactured by Minebea), at 25% compression according to JIS-K7220 The compressive stress of was measured. A sample size of 50 mm × 50 mm × 25 mm was used.

<Flower bud insertion and retention>
Insert the cut flower stalk (diameter: 4 mm, floret length: 50 mm, acute angle 30 ° angle of stem cut) into the obtained flower arrangement pedestal 20 mm vertically with respect to the pedestal. It was judged good when the stem of the cut flower could be fixed and held only by the pedestal. When the stem of the flower could not be inserted, or when it could not be fixed or held, it was not allowed.
○: Good ×: Impossible

Example 1
Twin screw extrusion of 100 parts by weight of non-crystalline polylactic acid resin with a D-form ratio of 10% and MI value of 3.7 g / 10 min and 2.0 parts by weight of a polyisocyanate compound (manufactured by Nippon Polyurethane Co., Ltd., MR-200) Was melt-kneaded at a cylinder temperature of 185 ° C. using a machine (Toshiba Machine, TEM35B), and about 1 mmφ (about 1.5 mg) bead-like amorphous polylactic acid resin particles were obtained using an underwater cutter.

  100 parts by weight of water, 12 parts by weight of deodorized butane (normal butane / isobutane weight ratio = 7/3) as a foaming agent, 10 parts by weight of sodium chloride and dispersion, with respect to 100 parts by weight of the obtained amorphous polylactic acid resin particles As an auxiliary, 0.3 part by weight of polyoxyethylene oleyl ether was charged into an autoclave and maintained at 84 ° C. for 90 minutes. After sufficiently cooling, the product was taken out and dried to obtain amorphous polylactic acid resin expandable particles. The resulting amorphous polylactic acid resin foamable particles had a foaming agent impregnation rate of 5.5%.

The amorphous polylactic acid resin foamable particles are put into a pre-foaming machine (Daisen Kogyo Co., Ltd., BHP-300) and kept at 90 ° C. for 40 to 60 seconds to obtain amorphous polylactic acid resin foamed particles. It was. The obtained amorphous polylactic acid resin foamed particles were air-dried, and then the fused particles were separated using a sieve. The bulk magnification of the separated amorphous polylactic acid-based resin expanded particles was 0.025 g / cm ³ .

A 300 × 450 × 25 mm mold was placed on a foam molding machine (Daisen Kogyo, KR-57), and the amorphous polylactic acid resin foamed particles obtained above were filled at a compression rate of 0%, and the vapor pressure In-mold molding was carried out at 0.1 MPa for 10 to 20 seconds to obtain an amorphous polylactic acid resin foam molded body having a density of 0.025 g / cm ³ . Next, the obtained foamed molded product was cut to 100 × 100 × 25 mm, and left for 15 hours in a constant temperature and humidity chamber with a temperature of 80 ° C. and a relative humidity of 95% to perform hydrolysis treatment, and a flower arrangement pedestal was Obtained. The amount of heat of fusion of this pedestal for flower arrangement was determined by differential scanning calorimetry. In addition, the open cell ratio, 25% compressive strength, floret insertion and retention were evaluated. The results are shown in Table 1.

(Example 2)
Example 1 except that the amorphous polylactic acid-based resin foam molded body obtained in Example 1 was left to stand for 24 hours in a constant temperature and humidity chamber having a temperature of 80 ° C. and a relative humidity of 95%, followed by hydrolysis treatment. A pedestal for flower arrangement was obtained by the same method as in Example 1, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

Example 3
Example 1 except that the amorphous polylactic acid-based resin foam molded body obtained in Example 1 was left to stand in a constant temperature and humidity chamber at a temperature of 80 ° C. and a relative humidity of 95% for 48 hours for hydrolysis treatment. A pedestal for flower arrangement was obtained in the same manner as described above, and the open cell ratio, floret insertion and retention were evaluated. The results are shown in Table 1.

Example 4
An amorphous polylactic acid resin foamed molded article having a density of 0.037 g / cm ³ was produced in the same manner as in Example 1, and allowed to stand in a constant temperature and humidity chamber at a temperature of 80 ° C. and a relative humidity of 95% for 15 hours. Hydrolysis treatment was performed to obtain a flower arrangement pedestal, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

(Example 5)
To prepare a amorphous polylactic acid resin expansion molding having a density of 0.020 g / cm ³ in the same manner as in Example 1, the temperature 80 ° C., in a constant temperature and constant humidity chamber relative humidity of 95% and allowed to stand 15 hours Hydrolysis treatment was performed to obtain a flower arrangement pedestal, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

(Example 6)
As a hydroxy acid condensate, poly 3- (hydroxybutyrate-cohexanoate) (melting point 135 ° C., weight average molecular weight 700,000, specific gravity 1.2 g / ml) 100 parts by weight, and polyisocyanate compound 2 parts by weight (Nippon Polyurethane) Made by Millionate MR-200 (isocyanate group 2.7 to 2.8 equivalents / mol) and then melt-kneaded at a cylinder temperature of 150 ° C. with a 30 mmφ twin screw extruder (Ikegai Seisakusho, PCM30). The strand extruded from a 3 mmφ small hole die attached to the tip of the extruder was cut with a pelletizer to produce poly 3- (hydroxybutyrate-cohexanoate) resin particles having a particle weight of 5 mg and a melting point of 138 ° C. .

  After charging 100 parts by weight of the resin particles in a 4.5 L pressure vessel, 25 parts by weight of isobutane is added as a foaming agent and stirred. After raising the temperature of the container to 119 ° C. (foaming temperature), After maintaining for 1 hour in a state where the internal pressure of the container is 2.5 MPa, poly 3- (hydroxybutyrate-cohexanoate having a foaming ratio of 30 times is released and foamed under atmospheric pressure through a small hole nozzle provided in the lower part of the pressure-resistant container. ) Obtained resin foam particles.

  The poly 3- (hydroxybutyrate-cohexanoate) resin expanded particles are filled into a 300 × 400 × 20 mm mold, and water vapor of 0.10 to 0.32 MPa (gauge) is introduced into the mold to expand the resin. The particles were heated and fused to obtain a foamed molded article of poly 3- (hydroxybutyrate-cohexanoate) resin having an expansion ratio of 30 times. Further, a foamed poly 3- (hydroxybutyrate-cohexanoate) resin foam was allowed to stand in a high-temperature and high-humidity machine at 80 ° C./95% (temperature / humidity) for 4 weeks to produce a flour. The pedestal for the arrangement was used to evaluate the open cell ratio, floret insertion and retention. The results are shown in Table 1.

(Comparative Example 1)
The amorphous polylactic acid resin foam molded article obtained in Example 1 was used as it was as a pedestal for flower arrangement without hydrolysis, and the same evaluation as in Example 1 was performed. The results are shown in Table 1.

(Comparative Example 2)
The amorphous polylactic acid resin foam molded body obtained in Example 1 was allowed to stand in a dryer at a temperature of 80 ° C. and a relative humidity of 5% for 15 hours to form a flower arrangement pedestal, similar to Example 1. Was evaluated. The results are shown in Table 1.

Claims (5)

  It is made of an aliphatic polyester resin and has an open cell ratio of 50% or more. In a DSC curve obtained when the temperature is raised from 0 ° C. to 200 ° C. at 10 ° C./min in differential scanning calorimetry, the heat of fusion is 15 J / The base for flower arrangement which is more than g and less than 60J / g. The pedestal for flower arrangement according to claim 1 or 2, wherein the apparent density is 0.014 g / cm ³ or more and 0.038 g / cm ³ or less.   The pedestal for flower arrangement according to claim 1, wherein the aliphatic polyester resin is a polylactic acid resin.   The method for producing a pedestal for flower arrangement according to any one of claims 1 to 3, which is obtained by hydrolyzing a foamed molded article having an amorphous aliphatic polyester resin as a base resin.   The manufacturing method of the base for flower arrangements of Claim 4 which performs a hydrolysis on temperature and humidity conditions with a temperature of 60 degreeC or more and 100 degrees C or less and a relative humidity of 60% or more.