JP2006037019A - Selection method of material for soft polyurethane foam and production process of molded soft polyurethane - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a selection method of molded soft polyurethane foam without big change in hardness or repulsive elasticity coefficient when used for a seat cushion pad of automobiles and maintaining similar level of resonant oscillation rate with a declined magnification at about 2-4 Hz and a process for production of the molded soft urethane foam. <P>SOLUTION: The selection method of a material for soft polyurethane foam is characterized in selection of a material for soft polyurethane foam composed of a water containing a polyol component and an isocyanate component as a foaming agent to give a storage modulus of 10-25 N/mm<SP>2</SP>at a frequency of 4.0 Hz in a non-foamed molded product. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for selecting a material for flexible polyurethane foam and a method for producing a molded product of flexible polyurethane foam. In particular, the molded product of the flexible polyurethane foam obtained by the present invention is suitable for a seat cushion pad for a vehicle that vibrates during use, particularly an automobile.

  In general, flexible polyurethane foam is widely used for seat cushion materials for automobiles, cushion materials for furniture, and the like by utilizing the cushioning properties. The flexible polyurethane foam molded body is comfortable to sit because of its soft surface, and it is difficult for the driver to get tired even after prolonged driving. A seat cushion pad made of a flexible polyurethane foam molded body is known. It is.

  Conventionally, in order to improve the ride comfort of an automobile seat cushion, a vibration frequency range (4 to 10 Hz: 6 Hz as an evaluation value) that a person feels uncomfortable with respect to the vibration transmissibility characteristics of JASO B-407. It is said that it is effective to greatly reduce the transmission rate (usually adopted). In particular, vibrations around 6 Hz are said to be the frequency that causes car sickness. Therefore, development has been carried out to keep the vibration transmission rate low even in automobile seat cushion pads made of urethane foam moldings. It was.

  However, the conventional seat cushion pad that suppresses the vibration transmissibility at 6 Hz has a large resonance magnification (resonance peak) that appears in the vicinity of 2 to 4 Hz in the vibration transmissibility characteristics, so that the occupant sits on the seat cushion for an automobile. When running, the sense of stability of the body is lost due to the vibration of the vehicle body, and the sense that the body swings up and down (so-called leopard feeling) could not be sufficiently prevented.

  For these reasons, seat cushion pads for vehicles, including automobiles, not only keep vibration transmission rates near 6 Hz low, but also improve safety during driving operations in order to reduce occupant sickness and fatigue. (Improved stability when seated on the seat cushion) is also necessary, and it is considered preferable to exhibit a low vibration transmissibility even in a wider range of frequencies.

  However, when the resonance magnification that generally appears in the vicinity of 2 to 4 Hz of the vibration transmissibility characteristic is lowered, the resonance peak position is higher in the vibration transmissibility characteristic curve (vertical axis: vibration transmissibility, horizontal axis: frequency). The vibration transmissibility on the relatively high frequency side (for example, 6 Hz) related to the cushioning property increases, resulting in an unfavorable vibration transmissibility characteristic curve that is broad overall. That is, in the vibration transmissibility characteristic curve, it is difficult to achieve both reduction of the resonance magnification and retention of the resonance frequency, or shift to the low frequency range, and reduction of the vibration transmissibility near 6 Hz as a result. I came.

  Up to now, as an attempt to lower the resonance magnification in the measurement of vibration transmissibility characteristics around 2 to 4 Hz, a seat cushion pad made of a flexible polyurethane foam molded body focused on specific physical property values (for example, see Patent Document 1), A flexible polyurethane foam molded article using a fluorosurfactant having a hydrophilic group as a foam stabilizer (for example, see Patent Document 2) is disclosed.

However, these properties are greatly influenced by the properties of the polyurethane resin itself and the properties of the foam, such as cell shape and air permeability. In other words, even if the material composition is changed for the purpose of improving the vibration transmissibility characteristics of this molded product of flexible polyurethane foam, it should be clearly judged and distinguished whether the effect is due to improved polyurethane resin characteristics or improved foam characteristics. I could not. For this reason, the development of a flexible polyurethane foam molded product that takes into account other characteristics and cost reductions other than those described above requires many experiments such as fine adjustment of the material configuration and optimization of molding conditions.
Japanese Patent Laid-Open No. 11-146821 JP-A-11-322875

  Therefore, the object of the present invention is to use the measurement in the vicinity of 2 to 4 Hz while maintaining the resonance frequency at the same level without greatly changing the hardness and the impact resilience when used as a seat cushion pad for an automobile. An object of the present invention is to provide a method for selecting a flexible polyurethane foam material having a reduced resonance magnification and a method for producing a flexible polyurethane foam molded body.

  In order to achieve the above object, the present inventors have conducted intensive research on the physical properties of a substantially non-foamed polyurethane molding obtained mainly by using a blend of materials for a flexible polyurethane foam. It has been found that the above object can be achieved by using the following materials selection method and flexible polyurethane foam molded body production method, and the present invention has been completed.

That is, the method for selecting a material for a flexible polyurethane foam according to the present invention is a method for selecting a material for a flexible polyurethane foam comprising a polyol component containing water as a foaming agent and an isocyanate component. The flexible polyurethane foam material is selected so that the storage elastic modulus at 0.0 Hz is in the range of 10 to 25 N / mm ² .

  According to the flexible polyurethane foam molded body obtained by the method for selecting a flexible polyurethane foam molded body of the present invention, as shown in the results of Examples, only the characteristics of the resin component can be evaluated by the selection method and the manufacturing method of the present invention. It is possible to easily select and obtain a flexible polyurethane foam molded article having a resonance frequency of 3.6 Hz or less and a resonance magnification of 3.0 or less simply by adjusting the air permeability with a foam stabilizer. There is no need to conduct many experiments accompanying the change of one component as in the prior art, and the material change becomes easy.

  The non-foamed polyurethane molded body in the present invention refers to a polyurethane molded body that does not substantially contain bubbles, and is preferably a polyurethane molded body that does not contain bubbles at all. There may be. The method of non-foaming polyurethane molding is not particularly limited. For example, centrifugal molding under the following conditions is a suitable example.

In the present invention, a predetermined polyurethane foam molding is obtained by using a polyurethane foam material having a storage elastic modulus of 10 to 25 N / mm ² at a frequency of 4.0 Hz of the obtained substantially non-foaming polyurethane molding. It is characterized by selecting. The storage elastic modulus is more preferably in the range of 15 to 21 N / mm ² . If less than 10 N / mm ^2, and, if greater than 25 N / mm ² is not flexible polyurethane foam molded article of interest can be obtained even by adjusting the air permeability.

The storage elastic modulus in the present invention refers to a value (N / mm ² ) obtained by dividing the stress having the same phase as the strain in the sinusoidal vibration by the strain, for example, viscoelasticity which is a dynamic viscoelasticity measuring device. It can be measured using a spectrometer (VES).

  Further, in the present invention, the non-foamed polyurethane molded body production step is a centrifugal molding at a rotation speed of 400 rpm or more and 90 ° C. or more for 10 minutes or more after the polyol component and the isocyanate component are mixed and injected into the mold. Including a molding step.

  According to the present invention, as shown in the results of the examples, in the non-foamed polyurethane molding production process, after the polyol component and the isocyanate component are mixed and injected into the mold, the rotational speed is not less than 400 rpm and 90 rpm. By including a molding step of centrifugal molding at a temperature of 10 ° C. or more for 10 minutes or more, a polyurethane molded body in which mixing of bubbles is greatly reduced, particularly a non-foamed polyurethane molded body can be obtained. Although the details of the reason why the foam of the polyurethane molded body obtained by the above production method is reduced and the foam becomes non-foamed are not clear, the combination of the rotational speed condition and the heat treatment condition is a foam of water and an isocyanate group. It is presumed that the bubbles generated by the chemical reaction were effectively broken and removed to the outside of the urethane composition.

  The method for selecting a polyurethane molded body according to the present invention is such that the process for producing the non-foamed polyurethane molded body mixes the polyol component and the isocyanate component and injects them into a mold, and then rotates at a rotation speed of 400 rpm or higher and 90 ° C. or higher. Including a molding step of centrifugal molding for 10 minutes or more. The rotational speed in the centrifugal molding is preferably 600 rpm or more, and more preferably about 600 to 1000 rpm. When the rotational speed is less than 200 rpm, foaming may remain inside the polyurethane molded body. On the other hand, when it exceeds 1200 rpm, the liquid tends to scatter, such being undesirable.

  Furthermore, the molding process condition includes a molding step of heat molding at 90 ° C. or more for 10 minutes or more. Centrifugal molding is preferably performed at 100 to 130 ° C. for 10 to 60 minutes, more preferably centrifugal molding at 100 to 110 ° C. for 10 to 60 minutes.

  The selection method preferably includes a molding step of centrifugal molding at 90 ° C. or higher for 10 minutes or more at a rotational speed of 400 rpm or higher, and then a molding step of heat molding at 130 ° C. or higher for 10 minutes or longer. Furthermore, it is more preferable to include a molding step of centrifugal molding at 100 to 130 ° C. for 10 to 60 minutes at a rotation speed of 600 rpm or higher, and then a molding step of heat molding at 130 to 170 ° C. for 10 to 60 minutes. If the molding process is performed outside this range, bubbles due to carbon dioxide gas often remain inside the polyurethane molded body during the molding process, which is not preferable.

  The present invention further includes a step of selecting a foam stabilizer so that the air permeability of the flexible polyurethane foam molding is in the range of 4.22 to 42.2 L / min. By selecting the foam stabilizer so that the air permeability is in the above range, a flexible polyurethane foam molded body having a resonance frequency of 3.6 Hz or less and a resonance magnification of 3.0 or less can be obtained.

  Regarding the adjustment of the air permeability in the present invention, a known method that can be generally used for adjusting the air permeability of a flexible polyurethane foam molded article, a flexible polyurethane foam molded article, or a seat cushion pad can be appropriately used.

  Further, in the method for producing a flexible polyurethane foam molding, a step of selecting a flexible polyurethane foam material by the selection method, and a step of producing a flexible polyurethane foam molding using the flexible polyurethane foam material selected by the above step , Including.

  In addition, it is considered that the polyurethane molded body obtained by the present invention is a foam-free polyurethane molded body reflecting the action of water molecules in the molding process from the raw material of the molding material containing water. By evaluating this non-foamed polyurethane molding, it is presumed that it would be useful for evaluating the physical properties of the resin that constitutes the cells of polyurethane foam moldings, which consisted of using water as a foaming agent. The

  The molded product of the flexible polyurethane foam obtained by the present invention is particularly suitable for a seat cushion pad for a vehicle with vibration during use, particularly an automobile. Moreover, when using the flexible polyurethane foam molding obtained by this invention as a seat cushion pad, the well-known general method used for seat cushion molding can be applied suitably.

  Examples of the polyol compound used in the polyol component of the present invention include those usually used as a polyol compound in the technical field of polyurethane. For example, compounds known as polyol compounds in the technical field of polyurethane, such as hydroxy-terminated polyesters, polycarbonates, polyester carbonates, polyethers, polyether carbonates, and polyester amides. These compounds may be used alone or in combination of two or more.

  Examples of the polyether polyol include polytetramethylene glycol (PTMG), polypropylene glycol (PPG), and polyethylene glycol (PEG).

  Examples of the polyester polyol include polybutylene adipate, polyhexamethylene adipate, and polycaprolactone polyol.

  Examples of the polyester polycarbonate polyol include a reaction product of a polyester glycol such as polycaprolactone polyol and alkylene carbonate, a reaction product of ethylene carbonate with a polyhydric alcohol, and then a reaction product obtained. And reaction products obtained by the reaction of a dicarboxylic acid with an organic dicarboxylic acid.

  In the present invention, a polymer polyol in which polymer particles are dispersed in the form of fine particles in a polyol component may be used.

  Examples of the polymer particles include particles such as addition polymerization polymers such as homopolymers or copolymers of vinyl monomers such as acrylonitrile, styrene, alkyl methacrylate, and alkyl acrylate, and condensation polymerization polymers such as polyester, polyurea, and melamine resin. Can be given. Of these, acrylonitrile and homopolymers or copolymers of styrene are preferred. In particular, a homopolymer of acrylonitrile is preferable. As the polymer particles, a system containing acrylonitrile polymer fine particles is preferable because the moldability of the seat cushion pad is good.

  The proportion of the polymer particles in the entire polyol component is economically inconvenient if the proportion is too large, and is preferably 40% by weight or less, more preferably 20% by weight or less. In order to effectively improve physical properties such as hardness and durability of the seat cushion pad, it is preferable that the content of the polymer particles in the entire polyol component is 1% by weight or more, further 2% by weight or more.

  The method for introducing such polymer particles into the polyol component is not particularly limited. For example, when the polymer particles are an addition polymerization polymer, in the polyol such as polyoxyalkylene polyol, in the presence of a radical polymerization initiator, By polymerizing vinyl monomers such as styrene and acrylonitrile, it can be stably dispersed in the polyol component. Polymer polyols (POP) are commercially available from Mitsui Takeda Chemicals, Asahi Glass, etc., and can be suitably used.

  Both the polyether polyol and the polyoxyalkylene polyol constituting the polymer polyol preferably have a lower terminal unsaturated group concentration. Specifically, the terminal unsaturated group concentration is 0.1 meq / g or less. Is preferred. When the unsaturated group concentration becomes high, the compression set of the flexible polyurethane foam molded article becomes large, and problems such as a decrease in durability occur.

  Examples of the polycarbonate polyol include diols such as 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, polyethylene glycol, polypropylene glycol and / or polytetramethylene glycol, phosgene, and diallyl carbonate. Reaction products with (for example diphenyl carbonate) or cyclic carbonates (for example propylene carbonate).

  As the isocyanate compound used as the isocyanate component in the present invention, a known compound in the field of polyurethane can be used without particular limitation. For example, 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 1,5-naphthalene diisocyanate, p-phenylene Aromatic diisocyanates such as diisocyanate, m-phenylene diisocyanate, p-xylylene diisocyanate, m-xylylene diisocyanate, aliphatic such as ethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 1,6-hexamethylene diisocyanate Diisocyanates, 1,4-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, isophorone diisocyanate Alicyclic diisocyanates such as norbornane diisocyanate, crude MDI, and the like. These compounds may be used alone or in combination of two or more.

  As the isocyanate compound, in addition to the diisocyanate compound, a trifunctional or higher polyfunctional isocyanate compound can also be used. As a polyfunctional isocyanate compound, for example, a series of diisocyanate adduct compounds are commercially available as Desmodur-N (manufactured by Bayer) or Duranate (manufactured by Asahi Kasei Kogyo).

  In the present invention, an isocyanate-terminated prepolymer can be appropriately used as a flexible polyurethane foam material. The isocyanate-terminated prepolymer is generally obtained by a polyaddition reaction of a polyol compound and an isocyanate compound, but may be synthesized by other methods. Moreover, although an isocyanate terminal prepolymer is generally obtained by making an isocyanate compound react more excessively than the molar equivalent with respect to a polyol compound, what was synthesize | combined by the other method may be used.

  In addition to the polyols described above, the constituents of the isocyanate-terminated prepolymer include, for example, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexane. Low molecular weight polyhydric alcohols such as diol, neopentyl glycol, 1,4-cyclohexanedimethanol, 3-methyl-1,5-pentanediol, diethylene glycol, triethylene glycol, 1,4-bis (2-hydroxyethoxy) benzene May be used in combination. These compounds may be used alone or in combination of two or more.

  The ratio of the polyol compound to the isocyanate compound in the present invention can be appropriately selected depending on the molecular weight of each, the desired physical properties of the molded body, and the like.

  The foaming agent in the present invention contains at least water, but a known foaming agent other than water may be used in combination as appropriate. One type of foaming agent other than water may be used alone or in combination with water, or two or more types may be used. Examples of blowing agents other than water include halogenated hydrocarbons such as HCFC-141b, HFC-134a, HFC-245fa, and HFC-365mfc, low-boiling aliphatic or alicyclic hydrocarbons such as cyclopentane and n-pentane, Examples thereof include liquefied carbon dioxide gas.

  As a raw material in the polyurethane molded product of the present invention, a chain extender, a reaction catalyst, and a crosslinking agent can be appropriately contained in addition to the above components. Moreover, these each component is not specifically limited, What is generally used as a raw material of a polyurethane resin can be used suitably, These may be used individually by 1 type and may be used together 2 or more types.

  In the present invention, a reaction catalyst may be used. Examples of the reaction catalyst include triethylenediamine (TEDA), bis (N, N-dimethylamino-2-ethyl) ether, N, N, N ′, N′-tetramethylhexamethylenediamine, and bis (2-dimethylamino). Examples thereof include amine catalysts such as ethyl) ether (TOYOCAT-ET, manufactured by Tosoh Corporation), carboxylic acid metal salts such as potassium acetate and potassium octylate, and organometallic compounds such as dibutyltin dilaurate. Among these, the use of an amine catalyst is preferable because it is suitable for the production of water-foamed polyurethane foam. These reaction catalysts may be used alone or in combination of two or more.

  In the production of the flexible polyurethane foam molded article of the present invention, a low molecular weight polyvalent active hydrogen compound can be appropriately used as a crosslinking agent as necessary. As such low molecular weight polyhydric active hydrogen compounds, polyhydric alcohols such as ethylene glycol, propylene glycol, 1,4-butanediol, trimethylolpropane, glycerin, and these polyhydric alcohols are used as initiators. Examples thereof include compounds having a hydroxyl value of 300 to 1000 mg KOH / g obtained by polymerizing ethylene oxide and propylene oxide, and alkanolamines such as monoethanolamine, diethanolamine, triethanolamine and N-methyldiethanolamine. These compounds may be used alone or in combination of two or more. Commercially available products using these compounds are also suitable. For example, KL-210 (manufactured by Mitsui Takeda Chemical Co., Ltd.), Hard Master 17 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), EL-980 (manufactured by Asahi Glass Co., Ltd.), etc. can give.

  In addition to the above-mentioned components, the polyurethane molded body of the present invention includes an antioxidant, an ultraviolet absorber, an anti-aging agent, a filler, a flame retardant, a plasticizer, a colorant, an antifoaming agent, an antifungal / antifungal agent. Various additives such as an agent may be added as necessary.

  Moreover, in the process of producing the flexible polyurethane foam molded body of the present invention, known methods that can be generally used for the flexible polyurethane foam molded body can be used as appropriate.

  In the material selection of the present invention, in the non-foamed polyurethane molded body for evaluating the characteristics of the resin component, the centrifugal molding method is not particularly limited, and a centrifugal molding machine that can be generally used for centrifugal molding of resin or the like can be used as appropriate. In the molding process, any centrifugal molding can be used without any particular limitation as long as it is a technique that suppresses the remaining of bubbles and further eliminates bubbles.

  The centrifugal molding machine in this invention is illustrated in FIG. The centrifugal molding machine 1 has a cylindrical mold 10 having a molding part 14 for molding a cylindrical sheet on the inner surface and a rotating shaft 12 for rotating the cylindrical mold 10. By rotating the cylindrical mold 10 and supplying a mixed raw material liquid of a polyurethane molded body to a molding portion formed on the inner surface and performing centrifugal molding, a cylindrical sheet substantially free of bubbles can be molded.

  FIG. 2 shows a cross-sectional shape in the vicinity of the opening side end portion of the cylindrical mold 10 shown in FIG. A step 18 is formed at the opening end of the cylindrical mold 10, and sheet molding is possible with the molding part 14, and a foaming reaction between water and isocyanate groups is caused by the mixed raw material liquid of the polyurethane molding. The non-foamed polyurethane sheet 16 containing the resulting urea bond is molded.

  For the adjustment of the raw material mixture in the present invention, a method generally used for polyurethane resins can be appropriately used. For example, there is a technique in which a liquid containing a polyol compound and water and a liquid containing an isocyanate compound are prepared, and a mixture thereof is injected into a mold of a centrifugal molding machine. In such a raw material mixture, it is preferable not to add a foam stabilizer. The foam stabilizer in the present invention is mainly involved in the adjustment of air permeability, and bubbles generated due to the presence of the foam stabilizer in the system are less likely to break, which is likely to be harmful in non-foaming molding. The presence or absence of water affects the chemical and physical properties of the resin that constitutes the cell. On the other hand, the presence of a foam stabilizer in the system within the normal usage range is a resin that constitutes the cell. It is presumed that it does not particularly affect the chemical and physical properties of At this time, it is preferable to add an antifoaming agent, and additives such as a reaction catalyst may be added to each solution.

  Moreover, in the centrifugal molding in the present invention, a publicly known method generally used accompanying centrifugal molding can be appropriately used. For example, in order to improve releasability and productivity, a release agent may be applied to the wall surface in advance, or a mold may be subjected to a release treatment such as polytetrafluoroethylene coating.

  The adjustment of the air permeability using a foam stabilizer can be performed, for example, by adjusting the bubble (cell) diameter of the polyurethane foam. If the cell diameter is reduced, the air permeability can be lowered.

  The step of adjusting the air permeability of the flexible polyurethane foam molded body includes a method of adjusting at the time of molding the flexible polyurethane foam molded body and a method of adjusting by post-processing after molding the flexible polyurethane foam molded body. Can be used arbitrarily.

  In the process for producing a flexible polyurethane foam molded article having an adjusted air permeability, the air permeability can be adjusted by the type and amount of the foam stabilizer. In the raw material blend of the flexible polyurethane foam molded body selected as described above, for example, components generally usable for polyurethane foam formation such as a foam stabilizer may be appropriately used.

  Moreover, as a foam stabilizer in this invention, what is used for manufacture of a normal flexible polyurethane foam can be especially used without a restriction | limiting. Examples thereof include various foam stabilizers such as dimethylsiloxane, polyether dimethylsiloxane, and phenylmethylsiloxane. The amount of the foam stabilizer used is usually 0.01 to 5 parts by weight (based on the active ingredient in the case of a foam stabilizer diluted with a plasticizer or the like) with respect to 100 parts by weight of the polyol component, preferably 0. .1 to 2 parts by weight.

  As a highly active silicone-based foam stabilizer, it can be used in combination with known foam stabilizers such as polydimethylsiloxane and its derivatives as appropriate. Commercially available products are preferably used as the highly active silicone-based foam stabilizer. Specifically, for example, SF2965, SF2962, SF2904, SF2908, SRX294A (manufactured by Toray Dow Corning Silicone), L-5366, L- 5309 (manufactured by Nihon Unicar), B8680 (manufactured by Goldschmidt), and the like are commercially available. Particularly effective is the use of a foam stabilizer having a surface tension reducing ability (difference in surface tension before and after addition to the polyol component) of about 1 (dyne / cm). SF2965, SF2962, B8680, L-5366, L -5309 is particularly preferred. However, it is also possible to adjust the air permeability by adjusting the surface tension and the ability to lower the surface tension by using a plurality of foam stabilizers in combination instead of a single foam stabilizer.

  Thus, a flexible polyurethane foam molded body molded into a predetermined shape as a seat cushion pad can be obtained. On the back surface of the seat cushion pad, for example, a supporter of a resin made of polyurethane, polypropylene, polyethylene, polystyrene or a foam thereof or PP cloth is used. Further, a supporter (reinforcing material) such as a coarse blanket or a non-woven fabric can be laminated by an integral molding method in which a supporter (reinforcing material) is inserted into a mold in advance during molding or by adhesion after foam molding.

  A seat seat or the like that is actually mounted on a vehicle is used for assembling the vehicle by covering the seat cushion pad of the present invention with an outer layer such as a main skin, a moquette, a tricot, a jersey, and a fabric, and further attaching metal fittings. When the outer layer is coated on the seat cushion pad, it is also preferable to attach one surface fastener member to the seat cushion pad by adhesion or the like.

  Examples and the like specifically showing the configuration and effects of the present invention will be described below. In addition, the evaluation methods, such as a physical property in an Example etc., are as follows.

[Materials for non-foamed polyurethane moldings and materials for flexible polyurethane foam]
The contents and suppliers of the materials used for the production of polyurethane moldings are as follows.

a) Polyol: EP901, hydroxyl value = 24 ± 2 (mgKOH / g) (manufactured by Mitsui Takeda Chemical Co., Ltd.)
b) Polyol: EP3033, hydroxyl value = 34 ± 2 (mgKOH / g) (Mitsui Takeda Chemical Co., Ltd.)
c) Polyol: EP3028, hydroxyl value = 28 ± 2 (mg KOH / g) (Mitsui Takeda Chemical Co., Ltd.)
d) Polymer polyol: POP3690, hydroxyl value = 21 ± 2 (mgKOH / g) (Mitsui Takeda Chemical Co., Ltd.)
e) Polymer polyol: POP3628, hydroxyl value = 26 ± 2 (mgKOH / g) (manufactured by Mitsui Takeda Chemical Co., Ltd.)
f) Polymer polyol: POP3128, hydroxyl value = 27.5 ± 1.5 (mg KOH / g) (Mitsui Takeda Chemical Co., Ltd.)
g) Crosslinking agent: DEA, diethanolamine (Mitsui Chemicals)
h) Foam stabilizer: SF2962 (manufactured by Toray Dow Corning Silicon)
i) Foam stabilizer: SF2969 (manufactured by Toray Dow Corning Silicon)
j) Foam stabilizer: SRX274C (manufactured by Toray Dow Corning Silicon Co., silicone foam stabilizer)
k) Catalyst: TEDA-L33, 33% triethylenediamine solution (manufactured by Tosoh Corporation)
l) Catalyst: TOYOCAT-ET: Bis (2-dimethylaminoethyl) ether (manufactured by Tosoh Corporation)
m) Isocyanate component A: Crude-MDI / TDI-80 = 20/80 mixed isocyanate n) Isocyanate component B: Crude-MDI / TDI-80 = 90/10 mixed isocyanate [Preparation of non-foamed polyurethane molding]
Centrifugal molding machine: ES-400 (manufactured by Toho Machine Industry Co., Ltd.)
Centrifugal rotating part, diameter 330mm, depth 420mm
Centrifugal molding conditions: A heat treatment was performed at a centrifugal rotation speed of 700 rpm at 100 ° C. for 30 minutes and then at 130 ° C. for 1 hour.

  Raw material charging method: Table 1 shows the blending amount of the non-foamed polyurethane molding material. Each component is blended in a conventional manner at a weight ratio described in the same table, and a solution comprising a mixture of each of the above compounds a) to g) and k) and water, and a compound comprising the above compounds m) to n). The mixed raw material obtained by stirring and reacting at 25 ° C. for 1 minute was put into the centrifugal molding machine and centrifugal molding was performed to produce a polyurethane sheet (420 × 1000 × 2 (mm)).

[Measurement of storage modulus]
The storage elastic modulus of the produced non-foamed polyurethane sheet was measured by a tensile test using a viscoelastic spectrometer (VES).

Apparatus: UBM Co., model number Rheogel-E4000
Mode: Tensile Waveform: Sine Wave Frequency: 1-10Hz
Initial strain: 3mm
Amplitude: 30 μm
Temperature: 23 ° C
Sample size: 5 × 1.3 × 20mm

[Production of flexible polyurethane foam moldings]
Table 2 shows the blending amount of the flexible polyurethane foam material. These polyol components a) to f), the crosslinking agent g), the foam stabilizers h) to j), the catalysts k) to l), the isocyanate components m) to n), and the water component as the blowing agent are the same. After blending in a conventional manner at the weight ratios shown in the table and mixing uniformly, the mold is kept in advance at 60 ° C., and a predetermined amount is injected into a flexible foam molding die of a predetermined shape and foamed and cured to form a flexible polyurethane foam. A molded body was obtained.

[Physical properties of flexible polyurethane foam moldings]
a) Foam density (kg / m ³ ): A density measured for a molded product of flexible polyurethane foam.

b) 25% ILD (Indentation Load Deflection) (kgf / 314 cm ² ): The load when the seat cushion pad is compressed 25% with a pressure plate having a diameter of 200 mm (conforms to JIS K6400). This value is preferably about 20 (kgf / 314 cm ² ) in terms of sitting comfort.

  c) Air permeability (L / min): Measured according to ASTM D-1564. That is, 50 mm in length, 50 mm in width, and 25 mm in thickness including the skin part under the hip point, which becomes the seating surface of the seat cushion pad, are collected from three locations, and a measuring instrument made by FLUID DATA is used. It is the measured value (DOW method).

[Vibration transmissibility characteristics of flexible polyurethane foam moldings]
The sample was cured under conditions of 60 ° C. × 6 minutes, and a sample having a shape of 400 × 400 × 100 mm was prepared and evaluated. Based on JASO B-407, a resonance in the frequency range of 1 to 10 Hz is obtained from a vibration transmissibility curve obtained by applying a forced vibration test with an amplitude of ± 2.5 mm by loading a 50 kg iron-steel pressure plate. The frequency (Hz) and the resonance magnification were measured. For measurement of the vibration characteristics, a seat cushion vibration tester C-1002DL (manufactured by Ito Seiki Co., Ltd.) was used.

（実施例、比較例）
上述した手法に従い、実施例１〜２及び比較例１〜３に対応する無発泡ウレタン成型体、及び軟質ポリウレタンフォーム成型体を得た。

(Examples and comparative examples)
According to the method mentioned above, the non-foaming urethane molding corresponding to Examples 1-2 and Comparative Examples 1-3 and the flexible polyurethane foam molding were obtained.

Table 3 shows the evaluation results of the obtained non-foamed urethane molded product and the flexible polyurethane foam molded product. From these results, in accordance with the present invention, a formulation having a storage elastic modulus in the range of 10 to 25 N / mm ² when foam-free molding is selected, and the air permeability is 4.22 to 42.2 L using this formulation. In any of Examples 1 and 2 prepared so as to be in the range of / min, a flexible polyurethane foam molded body having a resonance frequency of 3.6 Hz or less and a resonance magnification of 3.0 or less is selected and obtained. I was able to. On the other hand, in Comparative Examples 1 and 2, which did not satisfy the constituent requirements of the present invention and were manufactured so that the air permeability exceeded 42.2 L / min, the resonance magnification exceeded 3.0 and the storage elastic modulus was 25 N. In Comparative Example 3 exceeding / mm ² , the resonance frequency exceeded 3.6 Hz.

  From the above, it can be confirmed that the flexible polyurethane foam molded body having a resonance frequency of 3.6 Hz or less and a resonance magnification of 3.0 or less can be easily selected and obtained by the selection method and the manufacturing method of the present invention. It was.

It is a perspective view of centrifugal molding machine example 1. It is a fragmentary sectional view at the time of resin molding of the centrifugal molding machine example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Cylindrical metal mold 12 Rotating shaft 14 Molding part 16 Polyurethane sheet 18 Step part

Claims (6)

In the method for selecting a material for a flexible polyurethane foam comprising a polyol component containing water as a foaming agent and an isocyanate component, the storage elastic modulus at a frequency of 4.0 Hz in the case of a non-foamed polyurethane molding is 10 to 25 N / mm ² The method for selecting a material for a flexible polyurethane foam, wherein the material for the flexible polyurethane foam is selected so as to be in a range.   The manufacturing process of the non-foamed polyurethane molding includes a molding process in which the polyol component and the isocyanate component are mixed and injected into a mold, and then subjected to centrifugal molding at a rotation speed of 400 rpm or more and 90 ° C. or more for 10 minutes or more. The method for selecting a flexible polyurethane foam material according to claim 1.   The method for selecting a material for flexible polyurethane foam according to claim 2, wherein the rotational speed is 600 to 1000 rpm.   The method for selecting a material for flexible polyurethane foam according to claim 2 or 3, further comprising a second molding step of heat molding at 130 ° C or higher for 10 minutes or longer after the molding step.   Furthermore, a foam stabilizer is selected so that the air permeability of a flexible polyurethane foam molded object may be in the range of 4.22-42.2 L / min, The flexible polyurethane foam in any one of Claims 1-4 characterized by the above-mentioned. Material selection method. In the method for producing a flexible polyurethane foam molded body,
A step of selecting a flexible polyurethane foam material by the selection method according to claim 1, and
A step of producing a flexible polyurethane foam molded body using the flexible polyurethane foam material selected in the above step;
The manufacturing method of the flexible polyurethane foam molded object characterized by including.

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