JP6759648B2 - Polyurethane integral skin foam and its manufacturing method - Google Patents

Description

The present invention relates to a polyurethane integral skin foam (hereinafter, may be referred to as "ISF") and a method for producing the ISF. More specifically, the present invention relates to a method for producing an ISF, which has high impact resilience in a wide temperature range and is excellent in productivity and mechanical strength as a molded product.

ISF is widely used as a material for soles and interior parts of automobiles such as steering wheels because of its high productivity, mechanical strength, and good feel, but it is suitable for high-performance soles. Until now, the technology of ISF having a good mechanical strength while having a high repulsive modulus in a normal temperature range has not been known.

Patent Document 1 proposes a highly elastic flexible polyurethane foam having a relatively high density using diphenylmethane diisocyanate (hereinafter, may be referred to as “MDI”).

However, the polyurethane foam achieves a high elastic modulus by using a cross-linking agent and increasing the amount of chemical cross-linking, and has sufficient mechanical strength such as elongation and tear strength as a resin for soles and the like. Cannot be realized.

Further, Patent Document 2 describes a method of giving a low-density polyurethane molded product as a shoe sole member, but this is a complicated process, and the disclosed elastic modulus is not sufficient.

Japanese Unexamined Patent Publication No. 2003-342343 Japanese Patent Publication No. 2015-507513

An object of the present invention is to provide an ISF having a high rebound resilience in a wide temperature range and having excellent mechanical strength and productivity, and to provide a method for producing the ISF.

As a result of intensive studies and studies aimed at solving these problems, the present inventors may refer to polytetramethylene ether glycol (hereinafter, referred to as "PTMEG") having a specific molecular weight range as an organic polyisocyanate composition. The present invention has been completed by using an organic polyisocyanate composition having a specific isocyanate group content modified with urethane in (1).

That is, the present invention includes the following embodiments (1) to (12).

(1) A polyurethane integral skin foam made from at least an organic polyisocyanate composition (A), a polyol component (B), a catalyst (C), and a foaming agent (D), wherein the organic polyisocyanate composition (A) is used. Is a urethane modified product of diphenylmethane diisocyanate and polytetramethylene ether glycol having a number average molecular weight of 1,000 to 3,500, and is an organic polyisocyanate (a1) having an isocyanate group content of 7 to 25% by mass. Polyurethane integral skin foam.

(2) The organic polyisocyanate composition (A) is a urethane modified product of diphenylmethane diisocyanate, which is liquid at room temperature, and polytetramethylene ether glycol having a number average molecular weight of 1,000 to 3,500, and has an isocyanate group content of 7. The polyurethane integral skin foam according to (1) above, which is an organic polyisocyanate (a2) of ~ 25% by mass.

(3) The polyurethane integral skin foam according to (1) or (2) above, wherein the organic polyisocyanate composition (A) contains a viscosity reducing agent (F).

(4) The polyol component (B) contains polytetramethylene ether glycol (b1) having a number average molecular weight of 600 to 3,500, and the ratio of (b1) in the polyol component (B) is 50% by mass or more. The polyurethane integral skin foam according to any one of (1) to (3) above, which comprises the above.

(5) From the group in which the polyol component (B) contains a polyether polyol (b2) other than (b1), and (b2) is a polymerization initiator having an average number of functional groups of 2 to 4, and propylene oxide and ethylene oxide. The polyurethane integral skin according to any one of (1) to (4) above, which is a polymerization product of at least one selected and is a polyether polyol having a hydroxyl group equivalent of 1,000 to 3,000. Form.

(6) The polyurethane integral skin foam according to any one of (1) to (5) above, wherein the foam density is 150 to 500 kg / m3.

(7) Any of the above (1) to (6), characterized in that the elastic modulus is 60% or more, the elongation rate is 200% or more, and the tear strength is 30 N / cm or more. The polyurethane integral skin foam described.

(8) A method for producing a polyurethane integral skin foam in which an organic polyisocyanate composition (A) and a polyol component (B) are reacted in the presence of a catalyst (C) and a foaming agent (D). The isocyanate composition (A) is an organic polyisocyanate (a1) having an isocyanate group content of 7 to 25% by mass obtained by urethane-modifying diphenylmethane diisocyanate with polytetramethylene ether glycol having a number average molecular weight of 1,000 to 3,500. A method for producing polyurethane integral skin foam, which is characterized by the fact that.

(9) The organic polyisocyanate composition (A) has an isocyanate group content of 7 to 25 mass obtained by urethane-modifying diphenylmethane diisocyanate, which is liquid at room temperature, with polytetramethylene ether glycol having a number average molecular weight of 1,000 to 3,500. The method for producing a polyurethane integral skin foam according to (8) above, which is an organic polyisocyanate (a2) of%.

(10) The method for producing a polyurethane integral skin foam according to (8) or (9) above, wherein the organic polyisocyanate composition (A) contains a viscosity reducing agent (F).

(11) The polyol component (B) contains polytetramethylene ether glycol (b1) having a number average molecular weight of 600 to 3,500, and the ratio of (b1) in the polyol component (B) is 50% by mass or more. The method for producing a polyurethane integral skin foam according to any one of (8) to (10) above.

(12) From the group in which the polyol component (B) contains a polyether polyol (b2) other than (b1), and (b2) is a polymerization initiator having an average number of functional groups of 2 to 4, consisting of propylene oxide and ethylene oxide. The production of the polyurethane integral skin foam according to any one of (8) to (11) above, which is a polyether polyol having a hydroxyl group equivalent of 1,000 to 3,000 obtained by polymerizing at least one selected substance. Method.

In the present invention, the elastic modulus can be remarkably improved in a wide temperature range without deteriorating physical properties such as mechanical strength in IS F. Further, the ISF produced by the present invention can be widely used for materials requiring high elastic performance such as resin for shoe soles and is very useful. Further, during ISF production, high production stability in a general foaming apparatus can be realized.

The present invention will be described in more detail.

The polyurethane integral skin foam of the present invention is an organic polyisocyanate composition (A), a polyol component (B), a catalyst (C), and a foaming agent (D) as raw materials in the polyurethane integral skin foam. The isocyanate composition (A) is an organic polyisocyanate (a1) having an isocyanate group content of 7 to 25% by mass obtained by urethane-modifying diphenylmethane diisocyanate with polytetramethylene ether glycol having a number average molecular weight of 1,000 to 3,500. That is the feature.

The organic polyisocyanate composition (A) used in the present invention is an organic polyisocyanate (a1) in which MDI is urethane-modified with PTMEG, or MDI (hereinafter referred to as "liquid MDI") which is liquid at room temperature is PTMEG. It is an organic polyisocyanate (a2) modified with urethane. Here, the normal temperature is based on JIS Z8703 (standard condition at the test site) and means 20 ° C ± 15 ° C.

The isocyanate group content of the organic polyisocyanates (a1) and (a2) used in the present invention is 7 to 25% by mass, preferably 10 to 20% by mass. If the isocyanate group content is below the lower limit, the viscosity of the organic polyisocyanate becomes very high, making it difficult to introduce it into the foaming equipment, and the mixing capacity of isocyanates and polyols of general foaming equipment is sufficiently uniform. There is a problem that is not done. On the other hand, when the isocyanate group content is equal to or higher than the upper limit, the reaction between isocyanate and polyol and water as a foaming agent becomes random, and the repulsive modulus estimated to be caused by the enlargement of the urea bond repeating unit caused by the reaction between isocyanate and water. There is a marked decrease in the rate.

The urethane modifying polyols of the organic polyisocyanates (a1) and (a2) used in the present invention are PTMEG having a number average molecular weight of 1,000 to 3,500, preferably a number average molecular weight of 1,500 to 3, It is 500 PTMEG. If the number average molecular weight is below the lower limit, the PTMEG chain does not function sufficiently as a soft segment, and it becomes difficult to achieve the target value for the elastic modulus. On the other hand, if the molecular weight is equal to or higher than the upper limit, the hardness as ISF suitable for applications such as shoe soles cannot be obtained, the crystallinity of the PTMEG chain is increased, and the low temperature storage stability of the organic polyisocyanate is deteriorated. is there.

The urethane modification PTMEGs of the organic polyisocyanates (a1) and (a2) have a number average molecular weight of 1,000 to 3,500, more preferably a number average molecular weight of 1,500 to 3,500, which is obtained by ring-opening polymerization of tetrahydrofuran alone. A functional polyol is preferable in terms of mechanical properties centered on the elastic modulus, elongation, and tear strength. However, as long as the pre-polymerization monomer is in the range of up to 10 mol%, the effect of the present technology is not significantly impaired even if another ether unit is introduced into the molecule. Generally, 1,3-propanediol, 3-methyl-1,5-pentanediol, neopentyl glycol and the like can be introduced for the purpose of liquefying PTMEG at room temperature.

The MDI used for the organic polyisocyanate (a1) preferably contains 4,4'-MDI as a main component. In addition to 4,4'-MDI, MDI contains 2,2'-MDI and 2,4'-MDI as isomers, and the content of these isomers in MDI is preferably 60% by mass or less. When a large amount of MDI isomer is contained, the ISF hardness may be lowered, the reactivity may be lowered, and the productivity may be deteriorated.

Further, the MDI used in (a1) can contain polyphenylene polymethylpolyisocyanate (p-MDI) having a similar structure, but the elongation rate of ISF decreases due to the increase in the number of isocyanate functional groups, and the ISF derived from p-MDI. Since coloring and the like occur, the content of p-MDI is preferably 10% by mass or less, and more preferably 5% by mass or less, based on the MDI used for the organic polyisocyanate (a1).

The liquid MDI used for the organic polyisocyanate (a2) is
(1) React MDI at 200 ° C or higher,
(2) Add trimethyl phosphate, triethyl phosphate, etc. to MDI as a catalyst and react at 170 ° C or higher, or (3) Add a phospholen compound such as 3-methyl-1-phenyl-2-phospholene 1-oxide to MDI. After adding as a catalyst, react at 70 ° C. or higher, and add a reaction terminator at a predetermined reaction rate.
It contains at least one selected from the group consisting of a partially carbodiimide and a partially uretonimine modified product of MDI obtained by the above method. The liquid MDI used in the present invention is preferably a liquid MDI in which the reaction proceeds at a low temperature with a phosphorene catalyst from the viewpoint of preventing coloring of the ISF.

Further, after the above reaction is completed and the reaction terminator is added, the mixture is stored at a temperature of 50 ° C. or lower for 24 hours or more, and in a state where most of the carbodiimide bonds are converted into uretonimine bonds, gel permeation chromatography or the like, uretonimine The total content of the carbodiimide-modified MDI and the uretonimine-modified MDI in the liquid MDI measured by a method that does not decompose the bond is preferably 5 to 40% by mass, more preferably 10 to 35% by mass. When the total content of the carbodiimide-modified MDI and the uretonimine-modified MDI is within the above range, a suitable number of isocyanate functional groups can be obtained, and the viscosity at the time of use can also be adjusted appropriately. Further, even when ISF is used, the elongation rate and strength can be satisfied.

Similar to (a1), the liquid MDI used for the organic polyisocyanate (a2) has a total content of 2,2'-MDI and 2,4'-MDI of 60 mass as the MDI before carbodiimide modification or uretonimine modification. % Or less is preferable. This is for the same reason as in (a1).

Further, the liquid MDI used for the organic polyisocyanate (a2) can contain a small amount of p-MDI in the MDI before carbodiimide modification or uretonimine modification.

However, (a2) has a higher average number of isocyanate groups than (a1), and the MDI before carbodiimide modification or uretonimine modification needs to be kept at a maximum of 5% by mass, more preferably 3% by mass or less. is there.

As the polyol component (B) used in the present invention, PTMEG having a number average molecular weight of 600 to 3,500 can be preferably used. More preferably, it is 1,000 to 3,500. The content of (b1) in the polyol component (B) is preferably 50% by mass or more. More preferably, it is 60 to 90% by mass. Below the lower limit, the elastic modulus of the obtained ISF is not sufficiently high, and the mechanical properties such as tear strength are lowered. On the upper limit or higher, the rebound resilience at room temperature and the mechanical properties are improved, but the rebound resilience of ISF obtained from the crystallinity of PTMEG is significantly reduced in the low temperature range near 0 ° C.

As the polyol component (b2) other than (b1) used in the present invention, a hydroxyl group equivalent obtained by polymerizing at least one selected from the group consisting of propylene oxide and ethylene oxide with a polymerization initiator having an average number of functional groups of 2 to 4. 1,000 to 3,000 polyether polyols commonly used in the production of flexible polyurethane foams can be used. Specifically, as an initiator, water, ethylene glycol, propanediol, diethylene glycol, dipropylene glycol, butanediol, hexanediol, hydroquinone, glycerin, trimethylolpropane, hexanetriol, pentaerythritol, ethylenediamine, toluenediamine, methylenediphenyl. It is a polyether polyol obtained by addition-polymerizing ethylene oxide (EO), propylene oxide (PO), or both using diamine or the like. Further, it is also possible to use a polymer polyol obtained by radically polymerizing a vinyl compound such as acrylonitrile or styrene among the above polyols or by producing a urea compound by a reaction between an amine and an isocyanate.

As the catalyst (C), various urethanization catalysts known in the art can be used. For example, triethylamine, tripropylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, dimethylbenzylamine, N, N, N', N'-tetramethylhexamethylenediamine, N, N, N', N ", N" -pentamethyldiethylenetriamine, bis- (2-dimethylaminoethyl) ether, triethylenediamine, 1,8-diazabicyclo [5.4.0] undecene-7, 1,2-dimethylimidazole, 1-butyl Tertiary amines such as -2-methylimidazole and their organic acid salts, amino alcohols such as dimethylethanolamine, N-trioxyethylene-N, N-dimethylamine, N, N-dimethyl-N-hexanolamine, And organic metal compounds such as these organic acid salts, stanas octoate, dibutyltin dilaurate, dioctyltin dilaurate, zinc naphthenate and the like. If necessary, two or more of these catalysts can be mixed and used. Further, these catalysts can be used by being dissolved in various solvents, polyols, plasticizers, etc. for the reasons of lowering the viscosity, liquefying, increasing the volume for improving the measurement accuracy of the molding machine, and the like.

Water is desirable as the foaming agent (D) used in the present invention, but if necessary, known ones that have little significant effect on the global environment or the like can also be used. There are two types of this known foaming agent, an inert low boiling solvent and a reactive foaming agent. The former includes dichloromethane, hydrofluorocarbon, hydrofluoroolefin, acetone, methyl formate, hexane, pentane, isopentane, cyclopentane and the like. Further, nitrogen gas, carbon dioxide gas, air and the like can be mentioned. Examples of the latter include azo compounds and sodium hydrogen carbonate, which are decomposed at a temperature higher than room temperature to generate a gas.

In the present invention, the auxiliary agent (E) may be used if necessary. Examples of such an auxiliary agent (E) include a foam stabilizer, a thickener, a pigment or dye, a reinforcing material or filler such as mica and glass fiber, a flame retardant, an antioxidant, an ultraviolet absorber, and a light stabilizer. Examples thereof include agents, antifungal agents, antibacterial agents, VOC catcher agents, etc., which can be used as needed.

Examples of the foam stabilizer include known ones generally used for producing polyurethane foam. For example, polydimethylsiloxane-polyalkylene oxide block polymer, vinylsilane-polyalkylene polyol polymer and the like can be mentioned.

The viscosity reducing agent (F) used in the present invention is a liquid substance generally used for reducing the viscosity of high-viscosity liquids, which does not contain an active hydrogen group, a carbodiimide group, a formyl group, etc. that react with an isocyanate group. Can be used. Preferably, the viscosity at 25 ° C. is 100 mPa · s or less from the viewpoint of viscosity reducing effect, the melting point is 0 ° C. or less from the viewpoint of handling, the flash point measured by the method of JIS K2265 is 70 ° C. or more from the viewpoint of safety, and toxicity. , It is preferable that the environmental pollution is low. Specifically, diethyl phthalate, dipropyl phthalate, dibutyl phthalate, dioctyl phthalate, diisononyl phthalate, diethyl adipate, dipropyl adipate, dibutyl adipate, dioctyl adipate, diisononyl adipate, diethyl maleate, Examples thereof include dipropyl maleate, dibutyl maleate, dioctyl maleate, tricresyl phosphate, tris β-chloropropyl phosphate, tributyl acetylcitate, and dibenzyl ether.

The content of the viscosity reducing agent (F) is preferably 25% by mass or less in the organic polyisocyanate composition. If the upper limit is exceeded, the moldability of the ISF molded product may deteriorate, and the mechanical properties such as the elastic modulus and tear strength may deteriorate.

The ISF according to the present invention comprises, for example, an organic polyisocyanate composition (A) and a polyol component (B) in the presence of a catalyst (C), a foaming agent (D) and, if necessary, an auxiliary agent (E). It is manufactured as a mold foam obtained by injecting into a mold after stirring and mixing, or a continuous sheet-like foam obtained by injecting into a conveyor having walls on the top, bottom, left and right. In both production methods, components other than the organic polyisocyanate composition (A) are mixed in advance to prepare a polyol premix, and the two components of this and (A) are mixed and foamed, and some or all of the components are used. It is possible to separately introduce the mixture into the mixing head of the stirring mixer and foam it.

The molar ratio (isocyanate group / NCO reactive group) of the total isocyanate group in the organic polyisocyanate composition of the present invention to the total isocyanate reactive group in the isocyanate reactive compound containing water is 0.5 to 1.2. (Isocyanate index (NCO INDEX) = 50 to 120) is preferable, and 0.6 to 1.1 (NCO INDEX = 60 to 110) is more preferable.

The use of the ISF of the present invention is not particularly limited, but usually, a foamed resin used for a shoe sole, a part of a shoe sole, a shoe insole, etc. having a repulsive modulus of about 40%, a conventional foam resin, or a conventional one. By replacing the ISF with the ISF according to the present invention, a very excellent usability can be obtained. The mechanical strength of the ISF required for such applications is an elongation rate of 200% or more and a tear strength of 25 N / cm or more. In order to realize this, the density of the ISF according to the present invention is at least 150 kg. / is required to be ^{m 3.} On the other hand, considering economic efficiency and productivity, the upper limit of the ISF density is preferably 500 kg / m ³ or less. Although it depends on the type and amount of the catalyst (C), when only water is used as the foaming agent, the number of copies of water required to achieve this density band is 100 parts by mass of the polyol component (B). It is 0.3 to 2.5 parts by mass.

Hereinafter, specific examples of the present invention will be described, but the present invention is not limited to the present examples alone. In the examples, all parts and% are based on mass unless otherwise specified.

[Organic Polyisocyanate Composition Synthesis Example I-1]
A reactor having a capacity of 1 L equipped with a stirrer, a thermometer, a cooler and a nitrogen gas introduction tube was charged with MDI: 439 g having an isomer content of 1%, heated to 75 ° C., and then PTMEG having a number average molecular weight of 1000 (PTMEG). 561 g of PTG-1000SN (manufactured by Hodogaya Chemical Industry Co., Ltd.) was charged, and the urethanization reaction was carried out for 2 hours while uniformly mixing with a stirring blade while maintaining the temperature. The mixture was cooled to room temperature to obtain an organic polyisocyanate composition "I-1" (NCO group content 10%).

[Organic Polyisocyanate Composition Synthesis Example I-2]
A reactor having a capacity of 1 L equipped with a stirrer, a thermometer, a cooler and a nitrogen gas introduction tube was obtained by carbodiimide-modifying and uretonimine-modified MDI having an isomer content of 1%, and having an MDI content of 68% and an isocyanate group. Liquid MDI with a content of 28.9%: 819 g was charged, the temperature was raised to 75 ° C., and then 182 g of PTMEG (PTG-2000SN: manufactured by Hodoya Chemical Industry Co., Ltd.) having a number average molecular weight of 2000 was charged and stirred while maintaining the temperature. The urethanization reaction was carried out for 2 hours while uniformly mixing with the blades. The mixture was cooled to room temperature to obtain an organic polyisocyanate composition "I-2" (NCO group content 23%).

[Isocyanate Synthesis Examples I-3 to I-18]
Using the raw materials shown in Tables 1 to 3, the organic polyisocyanate compositions I-3 to I-18 were obtained by performing the same operations as I-1 and I-2. The viscosity reducing agent was added after the reaction was completed and mixed uniformly. The raw material composition in the table is shown by mass.

PTG-1000SN: PTMEG manufactured by Hodogaya Chemical Co., Ltd., number average molecular weight = 1000.
PTG-2000SN: PTMEG manufactured by Hodogaya Chemical Co., Ltd., number average molecular weight = 2000.
PTG-3000SN: PTMEG manufactured by Hodogaya Chemical Co., Ltd., number average molecular weight = 3200.

PTG-650SN: number average molecular weight = 650

[Adjustment of polyol component]
The raw materials were uniformly mixed at the ratios shown in Tables 4 to 6 to prepare polyol components P-1 to P-18 as a polyol premix. The raw material composition is shown by mass.

The raw materials used in Tables 4 to 6 are as follows.

Polyol 1: Propylene oxide addition polymerization of glycerin, hydroxyl equivalent 1000.
Polypolymer 2: Propylene oxide of ethylene glycol, ethylene oxide addition polymerization, propylene oxide / ethylene oxide = 55/45 (mass ratio), hydroxyl group equivalent 1000.
Polypolymer 3: Pentaerythritol propylene oxide, ethylene oxide addition polymerization, propylene oxide / ethylene oxide = 86/14 (mass ratio), hydroxyl group equivalent 2000.
Polycarbonate 4: Propylene oxide of glycerin, ethylene oxide addition polymerization,
Propylene oxide / ethylene oxide = 86/14 (mass ratio), hydroxyl group equivalent 2300.
Polypolymer 5: Propylene oxide addition polymerization of ethylene glycol, hydroxyl group equivalent 3000.
Polypolymer 6: Propylene oxide addition polymerization of glycerin, hydroxyl equivalent 500.
Polypolymer 7: Propylene oxide addition polymer of ethylene glycol, hydroxyl group equivalent 5000.
Toyocat ET: 70% by mass DPG solution of bis- (2-dimethylaminoethyl) ether.
DABCO NCIM: 1-isobutyl-2-methylimidazole.
DOTDL: Dioctyltin dilaurate

ISFs were prepared using isocyanate prepolymers I-1 to I-18 and polyol premixes P-1 to P-18 as organic polyisocyanate compositions.

That is, each organic polyisocyanate composition whose temperature was adjusted to 45 ° C. and the polyol premix at the ratios shown in Tables 7 to 10 were 7000r. p. m. The mixture was mixed and stirred with a tabletop mixer at the rotation speed of. The mixture was heated to 60 ° C., a release agent was applied, the mixture was poured into a dry metal mold having a size of 300 mm × 300 mm × 5 mm, the mixture was covered, and the mixture was cured for 7 minutes. After curing, it was taken out from the mold to obtain an ISF test piece (hereinafter abbreviated as TP). The obtained TP was evaluated for density, hardness, mechanical properties and the like.

<Measurement method of mechanical properties>
The density is JIS K7222, hardness (Asker C, surface hardness with skin), TB (tensile strength, using No. 3 dumbbell), EB (tensile elongation, using No. 3 dumbbell), TR (tear strength, using B type dumbbell). ), The repulsive elastic modulus (Rupuke type) was measured according to JIS K7312. The elastic modulus at 0 ° C. was measured within 10 seconds by the same method as at room temperature after taking out the sample stored in a constant temperature bath whose temperature was adjusted to 0 ± 1 ° C. for 24 hours.

The evaluation results of the prepared ISF are shown in Tables 7 to 10.

As is clear from Tables 7 to 10, the ISF obtained by the present invention has a high elastic modulus and excellent mechanical strength. Specifically, in Tables 7 to 10, ISF Examples 1 to 24 in which the Asuka-C hardness was adjusted to about 20 to 60 were molded in Comparative Examples 1, 3 and 3. Compared with 5, the rebound resilience is remarkably improved.

The polyurethane integral skin foam according to the present invention, which has a low density, a high elastic modulus and good mechanical properties, which is not available in the conventional market, can be used for shoe soles, shoe insoles, industrial machine parts, toys, musical instruments, etc. It brings excellent effects such as improvement and weight reduction.

Claims (10)

A polyurethane integral skin foam made from at least an organic polyisocyanate composition (A), a polyol component (B), a catalyst (C), and a foaming agent (D), wherein the organic polyisocyanate composition (A) is. It is a urethane modified product of diphenylmethane diisocyanate and polytetramethylene ether glycol having a number average molecular weight of 1,000 to 3,500, and is an organic polyisocyanate (a1) having an isocyanate group content of 7 to 25% by mass , and a polyol component. (B) contains polytetramethylene ether glycol (b1) having a number average molecular weight of 600 to 3,500, and the ratio of (b1) in the polyol component (B) is 50% by mass or more. Polyurethane integral skin foam. The organic polyisocyanate composition (A) is a urethane modified product of diphenylmethane diisocyanate, which is liquid at room temperature, and polytetramethylene ether glycol having a number average molecular weight of 1,000 to 3,500, and has an isocyanate group content of 7 to 25 mass. The polyurethane integral skin foam according to claim 1, wherein the polyurethane is an organic polyisocyanate (a2). The polyurethane integral skin foam according to claim 1 or 2, wherein the organic polyisocyanate composition (A) contains a viscosity reducing agent (F). The polyol component (B) contains a polyether polyol (b2) other than (b1), and (b2) is at least selected from the group consisting of a polymerization initiator having an average number of functional groups of 2 to 4 and propylene oxide and ethylene oxide. The polyurethane integral skin foam according to any one of claims 1 to 3 , which is a polymerization product of one kind and is a polyether polyol having a hydroxyl group equivalent of 1,000 to 3,000. The polyurethane integral skin foam according to any one of claims 1 to 4 , wherein the foam density is 150 to 500 kg / m ³ . The polyurethane integral skin according to any one of claims 1 to 5 , wherein the elastic modulus is 60% or more, the elongation rate is 200% or more, and the tear strength is 30 N / cm or more. Form. In the method for producing a polyurethane integral skin foam in which the organic polyisocyanate composition (A) and the polyol component (B) are reacted in the presence of the catalyst (C) and the foaming agent (D), the organic polyisocyanate composition ( A) is an organic polyisocyanate (a1) having an isocyanate group content of 7 to 25% by mass obtained by urethane-modifying diphenylmethane diisocyanate with polytetramethylene ether glycol having a number average molecular weight of 1,000 to 3,500 . The polyol component (B) contains polytetramethylene ether glycol (b1) having a number average molecular weight of 600 to 3,500, and the ratio of (b1) in the polyol component (B) is 50% by mass or more. A method for manufacturing polyurethane integral skin foam. The organic polyisocyanate composition (A) is an organic in which diphenylmethane diisocyanate, which is liquid at room temperature, is urethane-modified with polytetramethylene ether glycol having a number average molecular weight of 1,000 to 3,500 and an isocyanate group content of 7 to 25% by mass. The method for producing a polyurethane integral skin foam according to claim 7 , which is a polyisocyanate (a2). The method for producing a polyurethane integral skin foam according to claim 7 or 8 , wherein the organic polyisocyanate composition (A) contains a viscosity reducing agent (F). The polyol component (B) contains a polyether polyol (b2) other than (b1), and (b2) is at least selected from the group consisting of propylene oxide and ethylene oxide as a polymerization initiator having an average functional group number of 2 to 4. The method for producing a polyurethane integral skin foam according to any one of claims 7 to 9 , wherein it is a polyether polyol having a hydroxyl group equivalent of 1,000 to 3,000, which is obtained by polymerizing one kind.