JP6993770B2 - Manufacturing method of low-resilience polyurethane slab foam and low-resilience polyurethane slab foam - Google Patents

Description

The present invention relates to a method for producing a low-resilience polyurethane slab foam and a low-resilience polyurethane slab foam .

Low-resilience polyurethane foam is used as a cushion body for pillows, shock absorbers, and the like.
Conventionally, as a method for producing a low-resilience polyurethane foam, a polyol having a functional group number of 1.5 to 4.5 and a hydroxyl value of 20 to 70 mgKOH / g and a polyol having a functional group number of 1.5 to 4.5 and a hydroxyl value of 14 to A method using a polyol of 300 mgKOH / g (Patent Document 1), or a polyol polyol having a hydroxyl group number of 2 to 3 and a hydroxyl value of 10 to 90 mgKOH / g, and a polyol having a hydroxyl group number of 2 to 3 and a hydroxyl value of 15 to 250 mgKOH. There is a production method using a / g polyether polyol (Patent Document 2).

However, the conventional low-resilience polyurethane foam has a problem that the hardness rapidly increases in a low temperature range. Urethane foam, which is highly temperature-dependent in terms of hardness, becomes hard in a low temperature range when used in winter, and the low resilience of the bending angle is impaired.

Japanese Unexamined Patent Publication No. 11-286566 Japanese Unexamined Patent Publication No. 2006-063254

The present invention has been made in view of the above points, and an object of the present invention is to provide a method for producing a low-resilience polyurethane slab foam capable of suppressing an increase in hardness in a low temperature range and a low-resilience polyurethane slab foam .

The first invention is a method for producing a low-resilience polyurethane slab foam by reacting a polyol and a polyisocyanate in the presence of a foaming agent and a catalyst and foaming by slab foaming, wherein the polyol has a molecular weight of 3700 to 7000. A polyether polyol A having 2 to 4 functional groups and a hydroxyl value of 20 to 50 mgKOH / g, and a polyether polyol B having a molecular weight of 800 to 1200 per functional group, 2 to 3 functional groups and a hydroxyl value of 40 to 70 mgKOH / g. The weight ratio of the polyol A to the polyol B is polyol A: polyol B = 55: 45 to 90:10, the polyisocyanate is an MDI-based isocyanate, and the isocyanate index is 60 to 115. It is characterized by.

The second invention is characterized in that, in claim 1, the low-resilience polyurethane slab foam has a rebound resilience of 10 to 22% after 80,000 times of 50% compression.

The third invention is a low-repulsion polyurethane slab foam obtained from a composition for low-repulsion polyurethane foam containing a polyol, an isocyanate, a foaming agent, and a catalyst, wherein the polyol has a molecular weight of 3700 to 7000 and a functional group number of 2 to 4. The polyol A comprises a polyether polyol A having a hydroxyl value of 20 to 50 mgKOH / g and a polyether polyol B having a molecular weight of 800 to 1200 per functional group, a functional group number of 2 to 3, and a hydroxyl value of 40 to 70 mgKOH / g. And the weight ratio of the polyol B is polyol A: polyol B = 55: 45 to 90:10, the isocyanate is an MDI-based isocyanate, the isocyanate index is 60 to 115, and after 50% compression 80,000 times. Is characterized by a repulsive elasticity of 10 to 22%.
The fourth invention is characterized in that, in the third invention , the ratio of the hardness of -30 ° C to the hardness of 23 ° C (hardness of -30 ° C / hardness of 23 ° C) is 20 times or less. do.
A fifth aspect of the invention is characterized in that, in the third or fourth invention , the low-resilience polyurethane slab foam is provided on a part or the entire surface of a vehicle seat cushion.

According to the present invention, the polyol has a molecular weight of 3700 to 7000, a functional group number of 2 to 4, a polyether polyol A having a hydroxyl value of 20 to 50 mgKOH / g, and a molecular weight per functional group of 800 to 1200 and a functional group number of 2 to 3. It is composed of a polyether polyol B having a hydroxyl value of 40 to 70 mgKOH / g, and the weight ratio of the polyol A to the polyol B is polyol A: polyol B = 55: 45 to 90:10, and the polyisocyanate is an MDI-based isocyanate. By setting the isocyanate index to 60 to 115, the ratio of the hardness at -30 ° C to the hardness at 23 ° C (-30 ° C hardness / 23 ° C hardness) is 20 times or less, which is a low-repulsion polyurethane. Foam can be obtained and the increase in hardness can be suppressed in a low temperature range.

It is a perspective view of an example of a seat cushion for a vehicle which has the low-resilience polyurethane slab foam of this invention in a part. It is a 2-2 sectional view of FIG. FIG. 3 is a sectional view taken along the line 3-3 of FIG. It is sectional drawing of another example of the seat cushion for a vehicle which has the low-resilience polyurethane slab foam of this invention in a part.

In the method for producing a low-resilience polyurethane slab foam of the present invention, a polyol and a polyisocyanate are reacted in the presence of a foaming agent and a catalyst, and foamed by slab foaming to obtain a low-resilience polyurethane slab foam.

The polyols are a polyether polyol A having a molecular weight of 3700 to 7000, a functional group number of 2 to 4, and a hydroxyl value of 20 to 50 mgKOH / g, and a molecular weight per functional group of 800 to 1200, a functional group number of 2 to 3, and a hydroxyl value of 40 to 70 mgKOH. It is composed of / g of a polyether polyol B. The molecular weight is a number average molecular weight.

The polyether polyol A has a molecular weight of 3700 to 7000, a functional group number of 2 to 4, a hydroxyl value of 20 to 50 mgKOH / g, and is used as a main polyol to set the glass transition point of the main polymer in a temperature range lower than room temperature. It is possible to suppress the increase in hardness in the low temperature range. Further, since the polyether polyol is superior in hydrolysis resistance as compared with the polyester polyol, it is also preferable because it is also excellent in moist heat aging resistance over a long period of time. The polyether polyol A is, for example, a polyhydric alcohol such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, shoe cloth, and ethylene oxide ( Examples thereof include polyether polyols to which alkylene oxides such as EO) and propylene oxide (PO) are added. The type of the polyether polyol A is not limited to one, and a plurality of types may be used.

The polyether polyol B has a molecular weight of 800 to 1200 per functional group, a functional group number of 2 to 3, and a hydroxyl value of 40 to 70 mgKOH / g, so that a conventionally used low molecular weight polyol or cross-linking agent can be used. It is possible to achieve low resilience without. The polyether polyol B is, for example, a polyhydric alcohol such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butylene glycol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, sorbitol, shoe cloth, and ethylene oxide ( Examples thereof include polyether polyols to which alkylene oxides such as EO) and propylene oxide (PO) are added. The type of the polyether polyol B is not limited to one, and a plurality of types of polyether polyols having a molecular weight of 800 to 1200 per number of monofunctional groups such as polyether polyols B1 and B2 may be used.

The weight ratio of the polyol A to the polyol B is polyol A: polyol B = 55 to 90:45 to 10, and more preferably polyol A: polyol B = 60 to 80:40 to 20. When the weight ratio of polyol A is less than 55 (that is, when the weight ratio of polyol B is larger than 45), even if the density of the low-resilience polyurethane slab foam is adjusted, the rebound resilience and the rebound resilience after repeated compression Exceeds 20%, and low resilience is impaired. On the other hand, when it exceeds 90 (that is, when the weight ratio of the polyol B is less than 10), the foam balance is lost and the foam formability of the foam becomes difficult. In the present invention, the density of the low-resilience polyurethane slab foam can be adjusted by using a foaming agent.

As the polyisocyanate, MDI-based isocyanate is used. Specific examples of the MDI-based isocyanate (diphenylmethane diisocyanate-based isocyanate) include 2,2'-diphenylmethane diisocyanate (2,2'-MDI), 2,4'-diphenylmethane diisocyanate (2,4'-MDI), 4, 4'-diphenylmethane diisocyanate (4,4'-MDI), Polymeric MDI which is a mixture of diphenylmethane diisocyanate and polymethylenepolyphenylene polyisocyanate, these urethane modified products, urea modified products, allophanate modified products, biuret modified products, and carbodiimide modified products. , MDI prepolymer obtained by reacting these isocyanates with polyols, etc., such as modified isocyanurates. A plurality of types of MDI-based isocyanates may be used in combination. By using MDI-based isocyanate as the polyisocyanate, the reactivity with the polyol or the like in the urethane raw material can be enhanced. Furthermore, the viscosity of the urethane-blended raw material can be increased by using a high molecular weight polyether polyol A having a molecular weight of 3700 to 7000, and the polyurethane foam obtained by reacting these raw materials with an MDI-based isocyanate is fine. It becomes a cell. As a result, the resulting polyurethane foam can have low air permeability. Therefore, the number of cells is preferably 60 to 90 cells / 25 mm, and the air permeability is preferably 1 cc / cm ² / sec or less.

The isocyanate index is preferably 60 to 115. If the isocyanate index is less than 60, good foam cannot be obtained. On the other hand, if the isocyanate index exceeds 115, the foam becomes too hard or a good foam cannot be obtained. The isocyanate index is a value obtained by dividing the number of moles of isocyanate groups in polyisocyanate by the total number of moles of active hydrogen groups such as hydroxyl groups of polyols and water as a foaming agent, multiplied by 100, and [NCO equivalent of polyisocyanate]. / Active hydrogen equivalent x 100].

As the foaming agent, water or a hydrocarbon such as pentane can be used alone or in combination. In the case of water, carbon dioxide gas is generated during the reaction between the polyol and polyisocyanate, and the carbon dioxide gas causes foaming. The amount of the foaming agent is appropriate, but in the case of water, 1 to 7 parts by weight is preferable with respect to 100 parts by weight of the polyol. Further, the density of the low-resilience polyurethane slab foam can be adjusted by setting the amount to 2 to 5 parts by weight.

As the catalyst, known catalysts for polyurethane foam can be used. For example, amine-based catalysts such as triethylamine and tetramethylguanidine, tin-based catalysts such as stanus octoate, and metal catalysts such as phenylmercury propionate or lead octenoate (also referred to as organic metal catalysts) can be mentioned. Can be done. The amount of the catalyst is 0.1 to 3 parts by weight with respect to 100 parts by weight of the polyol.

In addition, other auxiliaries are appropriately included. For example, a foam stabilizer, a flame retardant, a colorant and the like can be mentioned.
As the foam stabilizer, those known for urethane foam can be used. For example, a silicon-based defoaming agent, a fluorine-containing compound-based defoaming agent, and a known surfactant can be mentioned. The amount of the foam stabilizer is 0.5 to 5 parts by weight with respect to 100 parts by weight of the polyol.
Flame retardants include halogenated polymers such as polyvinyl chloride, chloroprene rubber and chlorinated polyethylene, phosphoric acid esters and halogenated phosphoric acid ester compounds, organic flame retardants such as melamine resin and urea resin, antimony oxide and aluminum hydroxide. Inorganic flame retardants such as, etc. can be mentioned. The amount of the flame retardant is 1 to 25 parts by weight with respect to 100 parts by weight of the polyol.
Examples of the colorant include carbon black and the like. The amount of colorant is determined according to the type of colorant.

The composition for low-resilience polyurethane slab foam of the present invention contains the polyol, polyisocyanate, foaming agent, and catalyst described in the method for producing low-resilience polyurethane foam, and contains an appropriate auxiliary agent.

Further, slab foaming in the method for producing low-resilience polyurethane slab foam is a method in which a mixed composition for polyurethane foam (polyurethane foam raw material) is discharged onto a belt conveyor and foamed at room temperature under atmospheric pressure. Mold foaming is a method in which a mixed composition for polyurethane foam (polyurethane foam raw material) is filled in a mold (molding mold) and foamed in the mold.

The low-resilience polyurethane slab foam of the present invention obtained from the production method and composition of the present invention has an appropriate density, but a preferable density (JIS K 7222) is 20 to 80 kg / m ³ . If the density is less than 20 kg / m ³ , the cushioning property is lowered, and if the density is more than 80 kg / m ³ , it is unsuitable for vehicles in terms of weight reduction. The density of the low-resilience polyurethane slab foam of the present invention can be adjusted by adjusting the blending amount of the foaming agent. For example, by using water as a foaming agent in an amount of 1 to 7 parts by weight, more preferably 2 to 5 parts by weight, based on 100 parts by weight of the polyol, the density can be adjusted to 20 to 80 kg / m ³ .

The low-resilience polyurethane slab foam of the present invention has a rebound resilience (JIS K 6400-3: 2011) of 10 to 20% and a hardness (JIS K 6400) when the density (JIS K 7222) is 20 to 80 kg / m ³ . -2: 2004 D method) is 0.4 to 2.6 kPa. Further, the low-resilience polyurethane slab foam of the present invention has a rebound resilience of 10 to 22% after repeated compression of 80,000 times when the density (JIS K 7222) is 20 to 80 kg / m ³ , and repulsion due to repeated compression. It has little decrease in elasticity and is suitable for cushions that are used repeatedly by compression, for example, cushion sheets for vehicles, cushions for household use, and the like. The rebound resilience after repeated compression of 80,000 times is measured after the test conditions (compression cycle 60 times / min, 80,000 times with 50% compression) of repeated compression residual strain (JIS K 6400-4: 2011). ..

Further, the low-resilience polyurethane foam of the present invention has a ratio of hardness of -30 ° C to hardness of 23 ° C (hardness of -30 ° C / hardness of 23 ° C), that is, a hardness increase ratio at low temperature of 20. It is less than double, and the increase in hardness can be suppressed in the low temperature range. The hardness at 23 ° C. was measured by placing the measurement sample at 23 ° C. and 50% relative humidity for 24 hours or more, and then adjusting the condition, and then performing it in the same environment based on the JIS K 6400-2: 2004 D method. On the other hand, the hardness measurement at −30 ° C. is performed based on the JIS K 6400-2: 2004 D method after adjusting the state of the measurement sample at −30 ° C. for 30 minutes or more.

The low-resilience polyurethane slab foam of the present invention has a cell count of 60 to 90 cells / 25 mm and a breathability (JIS L 1096) of 1 cc / cm when the density (JIS K 7222) is 20 to 80 kg / m ³ . Low resilience is ² / sec or less, and the cells of the low-resilience polyurethane slab foam itself are fine (the number of cells is large) and the air permeability is low, so that low resilience can be realized, and the surface of the urethane foam is breathable. It is suitable for cushions having a structure that covers the skin material. Further, the low-resilience polyurethane slab foam of the present invention has a breathability (JIS L 1096) of 1 cc / cm ² / sec after repeated compression 80,000 times when the density (JIS K 7222) is 20 to 80 kg / m ³ . It is as follows, and there is no increase in air permeability due to repeated compression. In addition, the rebound resilience after repeated compression also maintains low repulsion, which is practical. Further, it is suitable for a cushion having a structure in which the surface of the urethane foam is covered with a breathable skin material. The air permeability after repeated compression of 80,000 times is measured after the test conditions (compression cycle 60 times / min, 80,000 times with 50% compression) of repeated compression residual strain (JIS K 6400-4: 2011). ..
Further, the low-resilience polyurethane slab foam of the present invention has a compression residual strain (JIS K 6400, method A) of 10% or less when the density (JIS K 7222) is 20 to 80 kg / m ³ , and the strain due to compression. It has less growth and is particularly suitable for compressed applications such as vehicle seats.

FIG. 1 is an example of a vehicle seat cushion 100 in which the low-resilience polyurethane slab foam F of the present invention is provided on a part of the surface.
The vehicle seat cushion 100 includes a seat seat cushion 10 and a backrest seat cushion 50. In addition, the seat cushion for a vehicle may indicate only one of the seat cushion 10 for the seat portion and the seat cushion 50 for the back support portion.
As shown in the cross-sectional views of FIGS. 2 and 3, the seat cushion 10 and the backrest seat cushion 50 have a shape in which the side portions 13, 13, 53, and 53 are raised, and the main body portions 21, 61. And the low-resilience polyurethane slab foam F of the present invention laminated and bonded to the side portions 13, 13, 53, 53.
Further, these vehicle seat cushions are used by wearing a breathable skin material (not shown) such as woven fabric, tricot, knit, jersey, and perforation synthetic leather.

The main body portions 21 and 61 are made of an elastic foam having a higher resilience than the low-resilience polyurethane slab foam F, and in the illustrated example, are made of a molded foam of a soft urethane foam. The rebound resilience (JIS K 6400-3: 2011) of the main bodies 21 and 61 is preferably 40 to 70%, and the hardness (JIS K 6400-2: 2004 D method) is preferably 0.4 to 2.6 kPa.

The low-resilience polyurethane foam F has a density (JIS K 7222) of 20 to 80 kg / m ³ , a resilience (JIS K 6400-3: 2011) of 10 to 20%, and a hardness (JIS K 6400-2: 2004). Method D) is 0.4 to 2.6 kPa, and the ratio of hardness at −30 ° C. (hardness at −30 ° C./hardness at 23 ° C.) to hardness at 23 ° C. is 20 times or less. The low-resilience polyurethane foam F is made of slab foam, processed to a thickness of 5 to 30 mm, and adhered to the side surfaces of the main bodies 21 and 61 with an adhesive or the like.

In the vehicle seat cushion 100, the seat cushion 10 and the backrest seat cushion 50 support the occupant by the central portions 11 and 51 to which the weight of the occupant is constantly applied, such as when the vehicle is cornering. When the occupant's posture is tilted, the occupant comes into contact with the side portions 13, 13, 53, 53 of the vehicle seat cushion, and the side portions support the occupant's posture.

The side portions 13, 13, 53, and 53 of the seat cushion 10 and the backrest seat cushion 50 are made of the low-resilience urethane foam F of the present invention, which has lower impact resilience than the central portions 11, 51. Therefore, when a high-speed load due to the inclination of the occupant is applied to the low-resilience polyurethane foam F on the side when the vehicle is cornering, the repulsive force on the side with respect to the occupant is reduced and high energy absorption is achieved. It is possible to reduce the tiredness of the occupant and obtain a good sitting feeling and a good support of the sitting posture. Further, even if a occupant with a large physique normally contacts the low-resilience polyurethane foam F on the side and presses the low-resilience polyurethane foam F on the side, the low-resilience causes a feeling of oppression on the occupant by the side. Can be reduced. Further, even when a small occupant comes into contact with the low-resilience polyurethane foam F on the side and lightly presses the side, the low-resilience polyurethane foam F on the side is deformed according to the degree of pressing and the vehicle seat. The cushion fits the occupant and gives a good seating feeling. Furthermore, even in areas with severe cold in winter, the low-resilience polyurethane foam F on the side is the ratio of the hardness of -30 ° C to the hardness of 23 ° C (hardness of -30 ° C / hardness of 23 ° C). Is 20 times or less, it is possible to suppress deterioration of low resilience due to an increase in hardness and maintain occupant support. In this way, the seat cushion for a vehicle is a cushion body, in particular, depending on the temperature condition before boarding the vehicle in winter (the temperature of the cushion is low) and the temperature control in the room and the body temperature in contact with the vehicle after riding the vehicle. Since the temperature changes easily, it is suitable for the application of the present invention.

The vehicle seat cushion 200 shown in FIG. 4 is an example in which the low-resilience polyurethane slab foam of the present invention is provided on the entire surface, and the illustrated example is for a seat portion. The vehicle seat cushion 200 is composed of a main body portion 71 and a low-resilience polyurethane slab foam F of the present invention laminated and bonded to the entire surface of the main body portion 71. The main body 71 is made of a molded foam of soft urethane foam and has higher impact resilience than the low-resilience polyurethane slab foam F. In the vehicle seat cushion 200, the low-resilience polyurethane slab foam F on the surface is responsible for the shock absorption, and the high-resilience main body 71 is responsible for the cushioning.

The following raw materials were mixed according to the formulations shown in Table 1 and reacted / foamed to prepare low-resilience polyurethane foams of each Example and each Comparative Example. The foaming method was an open foaming method by a slab method.
Polyol A: polyether polyol, molecular weight 5000, number of functional groups 3, hydroxyl value 34 mgKOH / g, product number; CP1421, manufactured by Dow Chemical Japan Co., Ltd. Polyol B1: polyether polyol, molecular weight 2000 (molecular weight 1000 per functional group) ), Number of functional groups 2, hydroxyl value 56.1 mgKOH / g, product number; D2000, manufactured by Mitsui Chemicals Polyurethane, Polyol B2: polyether polyol, molecular weight 3000 (molecular weight 1000 per number of functional groups), number of functional groups 3, hydroxyl value 56 .1 mgKOH / g, product number; GP3050NS, manufactured by Sanyo Kasei Kogyo Co., Ltd., polyol C: polyether polyol, molecular weight 700, number of functional groups 3, hydroxyl value 240 mgKOH / g, product number; V2070, manufactured by Dow Chemical Japan Co., Ltd. : Water / Catalyst A: Triethylenediamine, Part No .; 33LV, Air Product Japan Co., Ltd. ・ Catalyst B: Amin Catalyst, Part No .: NIAX A-1, Momentive Performance Materials Japan GK Co., Ltd. Foam regulator, product number; SZ-1136, Toray Dow Corning Co., Ltd. ・ Flame retardant: Phosphate ester type, product number: CR504L, manufactured by Daihachi Chemical Industry Co., Ltd. ・ MDI: Polymeric MDI, product number; "S-6564", NCO %; 29.9%, manufactured by Huntsman, TDI: TDI-80 (isomer ratio of 2,4-TDI 80% by mass and 2,6-TDI 20% by mass), NCO%; 48.2%, product number; coronate T -80, manufactured by Toso Co., Ltd.

For each obtained Example and each Comparative Example, density (JIS K 7222), rebound resilience (JIS K 6400-3: 2011), repulsive elasticity after 50% compression 80,000 times, number of cells (JIS K 6400). -1), Breathability (JIS L 1096), Breathability after 50% compression 80,000 times, Hardness (JIS K 6400-2: 2004 D method), Hardness increase ratio at low temperature (for hardness at 23 ° C) The hardness ratio at −30 ° C.) and the compression residual strain (JIS K 6400, method A) were measured.
The impact resilience after 80,000 times of 50% compression, the air permeability after 80,000 times of 50% compression, and the increase in hardness at low temperature were measured by the above procedure.

Example 1-3 is an example in which the isocyanate index is changed by 70-110 . Example 4 is an example in which polyol B2 is used instead of polyol B1 in Example 1, Example 5 is an example in which a flame retardant is blended in Example 1, and Example 6 is a blending of polyol A and polyol B1 in Example 1. This is an example of changing the ratio. Examples 7 and 8 are examples in which the amount of the foaming agent in Example 1 is changed.
In Examples 1-8, the density is as fine as 30 to 35 kg / m ³ , the number of cells is as fine as 62 to 70 cells / 25 mm, the air permeability is as low as 1 cc / cm ² / sec, and the impact resilience is 13 to 18%. The hardness was 0.6 to 2.2 kPa, the hardness increase ratio at low temperature was 8 to 18 times, the resilience was low, and the hardness increase at low temperature was small.

Comparative Example 1 is an example in which the isocyanate index of Example 8 is 120, Comparative Example 2 is an example in which the polyol of Example 1 is used alone as polyol A, and Comparative Example 3 is an example in which the polyol of Example 8 is 50 parts by weight of polyol A. An example in which the polyol B1 is composed of 50 parts by weight and the isocyanate index is 90 , Comparative Example 4 is an example in which the polyisocyanate of Example 8 is changed to TDI and the isocyanate index is 90, and Comparative Example 5 is a polyol B2. This is an example in which polyisocyanate is used as TDI, which is composed of Polyol C and Polyol C.
In Comparative Example 1 and Comparative Example 2, the foaming balance was lost and the foam could not be formed. Further, in Comparative Example 3 and Comparative Example 4, the number of cells was 50 to 58 cells / 25 mm, the air permeability was less than 1 to 3 cc / cm ² / sec, and the impact resilience was 21 to 25% higher than that of the examples, resulting in low resilience. It wasn't. In Comparative Example 5, although the number of cells was 50/25 mm and the air permeability was 50 cc / cm ² / sec, the rebound resilience was 9% and the repulsion was low, but the hardness increase ratio at low temperature was high. Was 40 times higher, and the increase in hardness at low temperatures was large.

As described above, the low-resilience polyurethane slab foam obtained by the production method and composition of the present invention has low resilience with fine cells and a small increase in hardness at low temperatures, and is provided on the surface of a vehicle seat cushion. It is suitable as a member to be used. The application of the low-resilience polyurethane slab foam of the present invention is not limited to the surface of a vehicle seat cushion, and is also suitable as a shock absorbing member whose operating temperature is in a low temperature range.

100, 200 Vehicle seat cushion 21, 61, 71 Main body 13, 53 Side F Low-resilience polyurethane slab foam of the present invention

Claims (3)

In a method for producing a low-resilience polyurethane slab foam by reacting a polyol and an isocyanate in the presence of a foaming agent and a catalyst and foaming by slab foaming.
The polyols are a polyether polyol A having a molecular weight of 3700 to 7000, a number of functional groups of 2 to 4, and a hydroxyl value of 20 to 50 mgKOH / g, and a molecular weight of 800 to 1200 per functional group, a number of functional groups of 2 to 3, and a hydroxyl value of 40 to 40. Consisting of 70 mgKOH / g of polyether polyol B,
The weight ratio of the polyol A to the polyol B is polyol A: polyol B = 55:45 to 90:10.
The isocyanate is an MDI-based isocyanate and is
Isocyanate index is 60-115,
The low-resilience polyurethane slab foam has a density (JIS K 7222) of 20 to 80 kg / m ³ , and a rebound resilience of 10 to 22% after 80,000 times of 50% compression.
The value of the rebound resilience after 80,000 times of 50% compression is repeatedly compressed under the test conditions of repeated compression residual strain (JIS K 6400-4: 2011) (compression cycle 60 times / min, 50% compression 80,000 times). A method for producing a low-resilience polyurethane slab foam provided on a part or all of the surface of a vehicle seat cushion, which is a value obtained by measuring the impact resilience after the compression. In a low-resilience polyurethane slab foam obtained from a composition for low-resilience polyurethane foam containing a polyol, an isocyanate, a foaming agent, and a catalyst.
The polyols are a polyether polyol A having a molecular weight of 3700 to 7000, a number of functional groups of 2 to 4, and a hydroxyl value of 20 to 50 mgKOH / g, and a molecular weight of 800 to 1200 per functional group, a number of functional groups of 2 to 3, and a hydroxyl value of 40 to 40. Consisting of 70 mgKOH / g of polyether polyol B,
The weight ratio of the polyol A to the polyol B is polyol A: polyol B = 55:45 to 90:10.
The isocyanate is an MDI-based isocyanate and is
Isocyanate index is 60-115,
Density (JIS K 7222) is 20-80kg / m ³ , The rebound resilience after 80,000 times of 50% compression is 10 to 22%.
The value of the rebound resilience after 80,000 times of 50% compression is repeatedly compressed under the test conditions of repeated compression residual strain (JIS K 6400-4: 2011) (compression cycle 60 times / min, 50% compression 80,000 times). A low-resilience polyurethane slab foam provided on a part or all of the surface of a vehicle seat cushion, which is a value obtained by measuring the impact resilience after the compression. The vehicle seat cushion according to claim 2, wherein the ratio of the hardness of -30 ° C to the hardness of 23 ° C (hardness of -30 ° C / hardness of 23 ° C) is 20 times or less. Low-resilience polyurethane slab foam provided on part or all of the surface.

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