JP2006089718A - Molded article of polyurethane foam - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a molded article of a polyurethane foam that can realize the production of a seat pad, a mattress and the like giving a comfortable feel to a person to sit on even if the thickness of the molded article is decreased. <P>SOLUTION: The molded article of the polyurethane foam is produced by foam molding a polyurethane foam blend comprising a polyol and an isocyanate as the main components and an organic clay blended therewith wherein the molded article of the polyurethane foam has a resonant frequency of 2-5 Hz and a density of 20-500 kg/m<SP>3</SP>; and the molded article of the polyurethane foam has a polyurethane layer having an impact resilience of 0.1-40% laminated on the back face thereof. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polyurethane foam molded product having a thin-walled portion, particularly to a polyurethane foam molded product for a seat pad or a mattress, which is used for various molded products such as automobile parts and indoor products.

Conventionally, polyurethane foam molded products are often used in automobile seat pads, mattresses, etc., but from the viewpoint of securing a larger interior space, and if the vehicle height can be lowered, the vehicle weight is reduced and fuel consumption is reduced. From the standpoint that it can be improved, there is a need to reduce the thickness of polyurethane foam molded products.
However, simply reducing the thickness of polyurethane foam moldings made of the same material can reduce the resilience and durability required for seat pads and mattresses, and provide a comfortable seat (bottom feeling, spring feeling, initial seating or continuous seating). There is a tendency to lead to a decrease in taste, etc.). For this reason, it is desired to develop a polyurethane foam molded article that can maintain a sitting comfort and the like even if it is thinned.

  For the purpose of improving the general characteristics of polyurethane materials, for example, Patent Document 1: Japanese Patent Application Laid-Open No. 10-168305 proposes a technique for combining a layered clay mineral with a polyurethane material. However, the invention according to this document is intended to improve the gas barrier property of a film or sheet-like molded product due to the contribution of the layered clay mineral, and the polyurethane foam used for the vehicle seat pad and mattress is not in mind, It does not pay attention to the problems caused by thinning the polyurethane foam molded product.

  In addition, the applicant of the present application previously found in Patent Document 2: Japanese Patent Application Laid-Open No. 2004-210976 that a polyurethane foam containing an organically treated inorganic filler becomes a high hardness and high durability polyurethane foam. ing. However, even in such an invention, there is still room for improvement in order to meet the above-mentioned needs for thinning mainly for automobile seat pads, mattresses, etc. (request for compatibility between thinning and sitting comfort). It was.

JP 10-168305 A JP 2004-210976 A

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a polyurethane foam molded product that can realize a seat pad, a mattress, and the like having good sitting comfort even if the molded product is thinned.

  As a result of diligent investigations to achieve the above object, the present inventor has made a polyurethane foam molding obtained by foaming a polyurethane foam compound (polyurethane foaming stock solution) composed mainly of polyol and isocyanate and blended with organic clay. The present invention makes it possible to realize a vehicle seat pad or the like that exhibits good resilience and high durability and maintains good sitting comfort even when thinned. It came to.

That is, the present invention provides the following polyurethane foam molded articles.
Claim 1:
A polyurethane foam molded article obtained by foam-molding a polyurethane foam compound containing a polyol and an isocyanate as main components and an organic clay.
Claim 2:
The polyurethane foam molded article according to claim 1, wherein 0.1-30 parts by mass of the organic clay is blended with respect to 100 parts by mass of the total amount of the polyol.
Claim 3:
The polyurethane foam molded article according to claim 1 or 2, wherein the resonance frequency is 2 to 5 Hz.
Claim 4:
The polyurethane foam molded article according to any one of claims 1 to ³ , wherein the density is 20 to 500 kg / m ³ .
Claim 5:
The polyurethane foam molded article according to any one of claims 1 to 4, which is used for a molded article having a thin portion.
Claim 6:
The polyurethane foam molded article according to any one of claims 1 to 5, which is used for a seat pad or a mattress.
Claim 7:
The polyurethane foam molded article according to any one of claims 1 to 6, wherein a polyurethane foam layer having a rebound resilience of 0.1 to 40% is laminated on the back surface of the polyurethane foam molded article.

  The polyurethane foam molded article of the present invention exhibits good resilience and high durability, and even when it is thinned, it has good sitting comfort (bottom feeling, spring feeling, initial seating or continuous seating) Vehicle seat pads, mattresses, and the like having preferences, etc.) can be realized.

  Hereinafter, the present invention will be described in more detail. The polyurethane foam molded article of the present invention is obtained by foam-molding a polyurethane foam compound mainly composed of polyol and isocyanate. Here, in the present invention, the “main component” means that the proportion of the total amount of polyol and isocyanate in the total amount of the polyurethane foam compound is usually 50% by mass or more, preferably 70% by mass or more, more preferably 90% by mass or more. It means that.

  Examples of the polyol include dihydric to hexavalent polyhydric alcohols, polyoxyalkylene polyols (polyether polyols), polyester polyols, polymer polyols, and the like. Of these, polyether polyols and polyester polyols are preferably used, and polyether polyols are particularly preferably used. These polyols may be used alone or in combination of two or more.

  As the polyether polyol, a polyether polyol obtained by ring-opening polymerization of alkylene oxide is preferable from the viewpoint of reactivity. Examples of such alkylene oxides include propylene oxide (PO) and ethylene oxide (EO). These may be used alone or in combination of two or more.

Among these, from the viewpoint of raw material activity, the polyether polyol is preferably a polyether polyol obtained by copolymerization of the PO and the EO. Examples of the polymerization initiator include pentaerythritol and glycerin.
The blending ratio of PO and EO during copolymerization is usually 8/92 to 18/82 (molar ratio) as EO / PO (molar ratio), preferably 13/87 to 15/85 (molar ratio). is there. When EO / PO (molar ratio) is out of the above range, it may be difficult to produce a polyether polyol.

  Further, the number of hydroxyl groups contained in one molecule of the polyether polyol is usually 2 to 4, particularly preferably 3. If the number of hydroxyl groups is too large, the raw material viscosity may increase, and if it is too small, the physical properties of the molded article may decrease.

  As the polyether polyol, it is preferable to use one having a low degree of unsaturation. More specifically, a polyether polyol having an unsaturation degree of usually 0.07 meq / g or less, preferably 0.04 meq / g or less is used. When the degree of unsaturation in the polyether polyol exceeds 0.07 meq / g, the durability and hardness of the polyurethane foam molded article of the present invention may be impaired. In the present invention, “unsaturation degree” is measured by a method in which acetic acid released by acting mercuric acetate on unsaturated bonds in a sample is titrated with potassium hydroxide in accordance with JIS K 1557-1970. Means the total degree of unsaturation (milli equivalent / g).

  As said polymer polyol, it is possible to use a general-purpose polymer polyol for polyurethane foam molded articles. More specifically, for example, a polymer polyol obtained by graft copolymerizing a polyether polyol with a polymer component such as polystyrene, polyacrylonitrile, or acrylonitrile-styrene copolymer can be given. The alkylene oxide used as a raw material for the polyether polyol (polyalkylene oxide) preferably includes propylene oxide, and particularly preferably includes propylene oxide alone or includes both propylene oxide and ethylene oxide. The proportion of the graft polymer component as described above in the polymer polyol is usually 25 to 50% by mass.

In the present invention, the polyether polyol and polymer polyol can be blended and used. When the polymer polyol is blended with the polyether polyol, it is preferable in that the hardness of the foam can be increased. On the other hand, when it is not blended, the rebound resilience of the obtained polyurethane foam molded article is further improved. It is suitable at the point which can be made.
When the polyether polyol and polymer polyol are blended and used, the blending ratio is usually 30/70 to 100/0, preferably 40/60 as (polyether polyol) / (polymer polyol) (mass ratio). ~ 80/20. When the blending ratio of both deviates from the above range, the physical properties of the polyurethane foam molded product of the present invention may be deteriorated or a reaction failure may occur.

  The number average molecular weight of each of the polyols in the present invention is usually 1000 to 10,000, preferably 2000 to 5000. If the number average molecular weight is too large, the stirring efficiency of the polyurethane foam stock solution may be inferior. On the other hand, if it is too small, the resilience of the resulting polyurethane foam may be greatly reduced. In the present invention, the number average molecular weight is a value calculated as a polystyrene equivalent value by the GPC method.

  The OH value of each polyol is usually 20 to 100, preferably 20 to 60. Moreover, as each said polyol, while the ethylene oxide terminal polyol which has an ethylene oxide unit in a molecular chain terminal is included, the ratio for which the ethylene oxide unit which exists in a molecular chain terminal occupies in all polyols is 0.1-20 mass%, especially 5-10 It is suitable from a viewpoint of reaction controllability that it is the mass%.

  Commercially available products can be used as the above polyols, for example, E-3030 (molecular weight 3000, f (number of functional groups; the same applies hereinafter) = 3, polyether polyol manufactured by Asahi Glass Co., Ltd.), V3943A (base polyol molecular weight 3000, f = 3, Dow Polyurethane Japan Co., Ltd. acrylonitrile / styrene 43% graft copolymer polyol), 3P56B (molecular weight 3000, f = 3, Takeda Pharmaceutical Co., Ltd. polyether polyol).

  A known isocyanate can be used as the isocyanate in the present invention. For example, tolylene diisocyanate, diphenylmethane diisocyanate, triphenyl diisocyanate, xylene diisocyanate, polymethylene polyphenylene polyisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and the like can be mentioned, and these can be used alone or in combination of two or more. May be.

  Among these, in the present invention, it is preferable to use tolylene diisocyanate (TDI) and / or diphenylmethane diisocyanate (MDI) as the isocyanate from the viewpoint of the molding density region. Here, the TDI is not particularly limited, but is a mixture having a blending ratio of 2,4-TDI and 2,6-TDI of 80/20 to 50/50 (mass ratio). A mixture of 80/20 to 65/35 (mass ratio) is particularly preferable. The MDI is not particularly limited, and can be used regardless of its molecular weight distribution. For example, pure (Pure) MDI (4,4'-MDI), polymeric MDI, crude MDI, etc. It can be used suitably.

  As such TDI and MDI, commercially available products can be used. As TDI, for example, T-80 (manufactured by Sumitomo Bayer Urethane Co., Ltd.), and as MDI, for example, 44V20 (manufactured by Sumitomo Bayer Urethane Co., Ltd.) MDI) can be used.

  When the TDI and MDI are used in combination, the mixing ratio of the two is usually 20/80 to 90/10 (mass ratio) as the value of TDI / MDI (mass ratio), preferably 50/50 to 80/20 ( Mass ratio).

  Although the compounding quantity of the said isocyanate is not restrict | limited in particular, It is 20-100 mass parts normally with respect to 100 mass parts of all polyols, Preferably it is 25-60 mass parts. If the amount of isocyanate is too small, the resinification reaction proceeds too much, resulting in closed cells and a suitable sheet may not be obtained. On the other hand, if the amount is too large, curing of the polyurethane foam may be delayed.

  The proportion of the isocyanate in the polyurethane foam stock solution (when two or more isocyanates are used in combination, the total amount of the isocyanate in the polyurethane foam stock solution) is an isocyanate equivalent (polyurethane foam stock solution). The equivalent (mole) ratio of isocyanate groups in the polyurethane foam stock solution when the amount of active hydrogen (mole) is 100 is usually 80 or more, preferably 95 or more, and the upper limit is usually 120 or less, preferably 115 or less. If the isocyanate equivalent is less than 80, the resulting polyurethane foam may suffer from shrinkage, while if it exceeds 120, foam may be down.

Examples of the clay used as the raw material for the organic clay in the present invention include, for example, a nesosilicate containing one silicon atom in a unit skeleton, a solosilicate containing several silicon atoms, an isosilicate containing a large number of silicon atoms, and a ferrosilicate. Specific examples include smectite clay minerals such as montmorillonite, saponite, hectorite, beidellite, stevensite, and nontronite, verculite, halloysite, and mica. These may be natural products or artificial synthetic products. These may be used alone or in combination of two or more.
The organic clay is obtained by organically treating such clay. Such an organic treatment method is not particularly limited, and a method of quaternary ammonium chlorination by ion exchange of a sodium ion as a counter ion of silicic acid, a chemical bond, an ion bond, etc. The method of introducing an organic group onto the surface of the silicate can be exemplified by the above, but from the viewpoint of dispersibility in the polyol, the silicate can be converted to 4 by exchanging sodium ions as counter ions of silicic acid. A method of quaternary ammonium chloride is preferred.

  Examples of the organic onium ions include hexyl ammonium ions, octyl ammonium ions, 2-ethylhexyl ammonium ions, dodecyl (lauryl) ammonium ions, octadecyl (stearyl) ammonium ions, dioctyl dimethyl ammonium ions, and distearyl dimethyl ammonium ions. An organic pyridinium ion such as an alkylbipyridinium ion, but is not limited thereto. Among these, organic ammonium ions are preferable from the viewpoint of stability in the polyol component. These are preferably quaternary ammonium ions, but may be protonated primary, secondary, or tertiary amines.

  Moreover, as said organic ammonium ion, the thing whose organic group couple | bonded with a nitrogen atom is an alkyl group and / or a hydroxyalkyl group is preferable, and especially the di (hydroxyalkyl) dialkyl ammonium ion is preferable. Examples of the alkyl group include a methyl group, an ethyl group, a propyl group, and a butyl group. On the other hand, the hydroxyalkyl group may be one having one OH group or two or more OH groups, and may be bonded to a terminal carbon atom such as a hydroxymethyl group, a 1-hydroxyethyl group, or a 1-hydroxypropyl group. Those having an OH group to be bonded, those having an OH group bonded to a carbon atom in the middle of the carbon chain, such as 2-hydroxy-n-propyl group and 2-hydroxy-n-butyl group, 1,3-dihydroxy-n- Examples thereof include those having an OH group bonded to a carbon atom at the terminal and in the middle of the carbon chain, such as a butyl group. Among these, those having an OH group at the terminal are preferable from the viewpoint of the strength of the produced flexible polyurethane foam. As an organic group couple | bonded with a nitrogen atom, you may have an ester bond, a urethane bond, etc. in the middle of carbon chains, such as an alkyl group and a hydroxyalkyl group. From the viewpoint of the stability of the dispersed state in the polyol component, it is also preferable to use a fluorinated silicate in which the OH group on the silicate surface is substituted with a fluorine atom.

  As a compounding quantity of the said organic clay, it is 0.1-30 mass parts normally with respect to 100 mass parts of whole quantity of the said polyol, Preferably it is 1-5 mass parts, More preferably, it is 2-3 mass parts. If the amount of the organic clay is too large, the viscosity of the foaming stock solution may become high and it may be difficult to finish the foam. There is a risk of not.

  In addition, as said organic clay, you may use a commercial item, for example, Somasif MEE, Somasif ME-100, Somasif MAE, Somasif MTE (all are the Corp Chemical Co., Ltd. product).

  In the present invention, from the viewpoint of adjusting (increasing) the hardness of the polyurethane foam molded article, a crosslinking agent may be blended in the polyurethane foam formulation. Examples of such a crosslinking agent include trimethylolpropane, diethylene glycol, sucrose (sugar), pentaerythritol, 1,4-butanediol, dipropylene glycol, ethylenediamine, glycerin, etc., and PO or EO added thereto. And alkylene oxide homopolymers (EO homopolymers and PO homopolymers). In particular, when an EO homopolymer is used as a cross-linking agent, it is possible to moderately suppress the initial reaction when the polyurethane foam compound is foam-cured, and the liquid spreads and foams to every corner in the mold. As a result of the stock solution being easily spread, abnormalities in the outer shape of the molded product (such as “chips” at the corners) are less likely to occur.

A commercial item can be used as said crosslinking agent, For example, Takeda Pharmaceutical Co., Ltd. product T-880, the company GR-04, Dow polyurethane Japan Co., Ltd. XQ82211 etc. can be mentioned.
Although it does not specifically limit as a compounding quantity of the said crosslinking agent, It is 0.1-10 mass parts normally with respect to 100 mass parts of all polyols, Preferably it is 1-5 mass parts.

In the polyurethane foam formulation, a foaming agent, a catalyst, a foam stabilizer and the like can be blended as necessary in the same manner as in a normal polyurethane foam formulation.
The foaming agent can be appropriately blended as necessary. For example, water can be suitably used, but a compound having a low boiling point such as methylene chloride and monofluorotrichloromethane can also be used. The blending amount of the foaming agent is appropriately adjusted, but is usually 0 to 15 parts by mass, preferably 1 to 5 parts by mass with respect to 100 parts by mass of the total polyol.

  As the catalyst, for example, amine-based and tin-based catalysts are preferably used. Examples of amine catalysts include tetramethylhexamethylenediamine, pentamethyldiethylenetriamine, dimethylcyclohexylamine, bis- (dimethylaminoethyl) ether, tetramethylpropylenediamine, trimethylaminoethylpiperazine, tetramethylethylenediamine, dimethylbenzylamine, methylmorpholine, Examples of tin-based catalysts such as ethylmorpholine and triethylenediamine include stannous octate and dibutyltin dilaurate. These may be used alone or in combination of two or more. Among them, triethylenediamine is suitably used for promoting resinification, and diethanolamine is suitably used for controlling the breathability of the resulting foam. As a compounding quantity of a catalyst, it is 0-5 mass parts normally with respect to 100 mass parts of all the polyols, Preferably it is 0.1-1 mass part.

  Examples of the foam stabilizer include organopolysiloxanes, alkyl carboxylates, and alkylbenzene sulfonates. As a compounding quantity of a foam stabilizer, it is 0-5 mass parts normally with respect to 100 mass parts of all the polyols, Preferably it is 0.5-2 mass parts.

  Furthermore, various additives can be added to the polyurethane foam formulation of the present invention as necessary, for example, colorants such as pigments, fillers such as calcium carbonate, antioxidants, flame retardants, Ultraviolet absorbers, light stabilizers, conductive materials such as carbon black, antibacterial agents, and the like can be blended.

  The polyurethane foam molded article of the present invention is obtained by foam-curing the above polyurethane foam composition. As the foaming method, for example, a one-shot method or a prepolymer method can be employed. The foaming temperature is usually 0 to 40 ° C., preferably 15 to 25 ° C., and the value of (specific gravity of foam molded product / specific gravity of raw material before foaming) is usually 1/1 to 1/5.

  The polyurethane foam molded article of the present invention is obtained by foam molding of the above-mentioned polyurethane foam composition. As a specific molding method, for example, organic mica is blended with polyol, water, amine catalyst and silicone. It is possible to employ a method in which the prepared raw material and isocyanate are simultaneously discharged and molded in a mold.

The polyurethane foam molded article of the present invention preferably has a resonance frequency of 2 to 5 Hz, particularly 2.5 to 3.0 Hz, from the viewpoint of improving the resilience and preventing the deterioration of durability. Moreover, the polyurethane foam molded article of the present invention has a density of usually 20 to 500 kg / m ³ , preferably 50 to 100 kg / m ³ , more preferably 55 to 70 kg / m from the viewpoint of securing the performance of the urethane foam molded article. ^The rebound resilience is usually 50 to 95%, preferably 70 to 90%, more preferably 78 to 85%, and the repeated compression thickness reduction rate measured according to JIS K 6400: 2004. Is usually 4% or less, preferably 0.5 to 2.0%.

In addition, when creating a vehicle seat or cushion using the polyurethane foam molded article of the present invention, from the viewpoint of realizing a better sitting comfort, there is a rebound resilience on the back surface of the polyurethane foam molded article of the present invention. It can be formed by laminating a polyurethane foam layer having a low resilience of about 0.1 to 40%. In particular, bonding three layers of polyurethane materials having different resilience and density is effective in forming a vehicle seat having excellent sitting comfort.
Here, when a vehicle seat or a cushion is prepared using the polyurethane foam molded article of the present invention, the thickness of the polyurethane foam molded article of the present invention is usually 40 to 200 mm, preferably 60 to 100 mm. If the thickness of the molded product is too small, the feeling of bottoming at the time of sitting may increase and the sitting comfort may deteriorate.

The polyurethane foam molded article of the present invention is useful, for example, for automobile / transportation vehicle seat pads or mattresses, and is particularly suitable for forming a thin seat pad or the like or forming a thin seat pad or the like. Can be adopted.
That is, the polyurethane foam molded article of the present invention has a high resilience and durability compared to conventional polyurethane foam molded articles, and therefore, a seat pad having the same resilience and durability as a conventional product. Since a thinner molded product is sufficient when forming the vehicle, it is possible to reduce the weight of the vehicle (improvement of fuel consumption) by securing the space in the vehicle interior and reducing the vehicle height. Moreover, in general, when the seat is thinned, the seating comfort generally tends to decrease, such as a deterioration in the feeling of bottoming of the seat, and many factors are intertwined with this seating comfortably. Although it is not as simple as being able to maintain sitting comfort, according to the present invention, details are not detailed, but even if the molded product is thinned, there is no reduction in rebound and durability. Moreover, it is possible to realize a molded product (seat pad, mattress, etc.) having a good sitting comfort.

  EXAMPLES Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not restrict | limited to the following Example.

[Examples 1 to 3, Comparative Example 1]
A polyurethane foam formulation for a seat pad was prepared according to the formulation shown in Table 1 below. Subsequently, it was foamed and molded by a one-shot method under conditions of a foaming liquid temperature of 25 to 35 ° C. and a foaming mold temperature of 55 to 65 ° C. to obtain a polyurethane foam molded product.
Various physical properties of the obtained polyurethane foam molded article were evaluated. The results are shown in Table 1 below.

Polyether polyol trade name F124 (Mitsui Takeda Chemical Co., Ltd.). A polyether polyol having a number average molecular weight of 7000 and a functional group (OH group) number of 3.
Polymer polyol trade name KC855 (manufactured by Sanyo Kasei Co., Ltd.). A polymer polyol obtained by graft copolymerizing a polymer component of acrylonitrile-styrene copolymer with polypropylene glycol having a number average molecular weight of 5000 and a functional group (OH group) number of 3.
4: 1 (mass ratio) blend of isocyanate TDI-80 (Sumitomo Bayer Urethane Co., Ltd., TDI) and 44V20 (Sumitomo Bayer Urethane Co., Ltd., Crude MDI).
Organic clay Somashif MEE (Co-op Chemical Co., Ltd., organic mica).
Catalyst A
Triethylenediamine, manufactured by Kao Corporation.
Catalyst B
Diethanolamine, manufactured by Nippon Shokubai Co., Ltd.
Foam stabilizer brand name SRX274C (manufactured by Toray Dow).

The density, resonance frequency, and resonance magnification were evaluated based on the JASO B 408 standard. In Table 1, the density value is an approximate value as a result of measuring a plurality of samples, and includes a fluctuation of about ± 5%.
Wet heat compression residual strain The wet heat compression residual strain was measured by the compression residual strain measurement method described in JIS K 6400: 2004. However, in the measurement, the core part of the molded flexible foam was cut out by 50 × 50 × 25 mm and used as a test piece. The test piece was compressed to a thickness of 50%, sandwiched between parallel flat plates, and left under conditions of 50 ° C. and relative humidity of 95% for 22 hours. And after leaving for 22 hours, this test piece was taken out, 30 minutes later, its thickness was measured, compared with the value of the thickness before the test, the strain rate was measured, and this strain rate was defined as the wet heat compression residual strain.
Rebound resilience was measured according to JIS K 6400: 2004. The ratio of the height at which the metal ball dropped from a predetermined position and bounced back to the initial height was defined as the rebound resilience.

[Examples 4 to 6, Comparative Example 2]
A polyurethane foam compounded according to the formulation of Example 2 or Comparative Example 1 was foamed and cured in a mold in the same manner as in Table 1 above, and a vehicle seat having the thickness shown in Table 2 below was prepared. The sitting comfort (preference) was evaluated by the method. The results are shown in Table 2 below. The density was evaluated in the same manner as in Table 1 above.

25% hardness Measured according to JIS K 6400: 2004. A rectangular parallelepiped foam sample was cut out from the center of the slab foam (portion not including the skin layer) to obtain a test piece.
In order to make it easy for air to escape from the test piece, the test piece was placed on a table with a number of small holes having a diameter of 6 mm and a center distance of 19 mm. Next, it was pressed from the upper surface of the test piece with a circular pressure plate having a diameter of 200 mm using an Instron type compression load tester having an automatic recording device. At this time, a test piece having a size including a circle having a diameter of 300 mm or more was used, and a test was performed by ILD (local compression).
The thickness when 4.9 N was applied as a preload was measured, and this was the initial thickness. Next, the circular pressure plate was pushed in at a distance of 75% of the initial thickness at a speed of 50 mm / min. Immediately after pressing, the pressure plate was raised at a speed of 50 mm / min and returned to the initial thickness. After being left for 1 minute, it was compressed again to the distance of 25% of the original thickness at the same speed, and the load after 20 seconds was read after being stopped. This was 25% hardness.
The test was carried out in accordance with a known sensitivity test ANOVA called “paired comparison method”. After selecting 10 panelists, they were asked to sit on the reference sample, and were given a score (evaluated in 7 levels from -3 to +3) for sitting comfort. Similarly, it was done by getting a score for sitting comfort. If the difference between the evaluation numerical values of the reference sample and the sample to be evaluated is equal to or larger than the yardstick value obtained for each measurement, the numerical value was entered as having a significant difference, and the average value was calculated. The yardstick value in Table 2 is 0.368, and the yardstick value in Table 3 is 0.373. In the present invention, “sitting comfort” is a measure of a total impression of a feeling of bottoming, a feeling of spring, a preference at the time of initial sitting or continuous sitting, and the like.

  From the results of Table 2 above, the polyurethane foam molded product of the present invention according to the formulation of Example 2 was compared with the conventional polyurethane foam molded product according to the formulation of Comparative Example 1 (the formulation without blending organic clay). It was found that the seating comfort was not impaired even when the thickness was reduced by about 20%. The weight of the sheet thinned by 20% according to the formulation of Example 2 is only about + 9% by weight compared to the weight of the conventional sheet according to the formulation of Comparative Example 1, and the polyurethane foam of the present invention It has been found that the molded article can be a molded article having both sitting comfort and thinning.

[Examples 7 to 9, Comparative Example 3]
A polyurethane foam compounded according to the formulation of Example 3 or Comparative Example 1 was foam-cured in a mold in the same manner as in Table 1 above, and a vehicle seat having the thickness shown in Table 3 below was created. The sitting comfort (preference) was evaluated by the method. Each evaluation was performed in the same manner as in Table 2 above. The results are shown in Table 3 below.

From the results of Table 3 above, the polyurethane foam molded product of the present invention according to the formulation of Example 3 is compared with the conventional polyurethane foam molded product according to the formulation of Comparative Example 1 (a formulation not containing an organic clay). It was found that the seating comfort was not impaired even when the thickness was reduced by about 20%. Moreover, the weight of the sheet thinned by 20% by the blending of Example 3 is about -7% by weight compared to the weight of the conventional sheet by the blending of Comparative Example 1, achieving further weight reduction. It was something to do. It has been found that the polyurethane foam molded article of the present invention can be a molded article that is compatible with both sitting comfort, thinning, and weight reduction.

Claims (7)

  A polyurethane foam molded article obtained by foam-molding a polyurethane foam compound containing a polyol and an isocyanate as main components and an organic clay.   The polyurethane foam molded article according to claim 1, wherein 0.1-30 parts by mass of the organic clay is blended with respect to 100 parts by mass of the total amount of the polyol.   The polyurethane foam molded article according to claim 1 or 2, wherein the resonance frequency is 2 to 5 Hz. The polyurethane foam molded article according to any one of claims 1 to ³ , wherein the density is 20 to 500 kg / m ³ .   The polyurethane foam molded article according to any one of claims 1 to 4, which is used for a molded article having a thin portion.   The polyurethane foam molded article according to any one of claims 1 to 5, which is used for a seat pad or a mattress. The polyurethane foam molded article according to any one of claims 1 to 6, wherein a polyurethane foam layer having a rebound resilience of 0.1 to 40% is laminated on the back surface of the polyurethane foam molded article.