JP2008179716A - Method for producing sheet for forming pad member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a sheet for forming a pad member, which suppresses discoloration and improves air permeability. <P>SOLUTION: The method for producing a sheet for forming a pad member comprises adding an isocyanate group-containing urethane prepolymer as a binder to chips obtained by grinding a polyurethane foam. The polyurethane foam is obtained by reacting an aliphatic polyisocyanate or alicyclic polyisocyanate with a polyol and the urethane prepolymer is obtained by reacting an aliphatic polyisocyanate or alicyclic polyisocyanate with a polyol. Successively, the chips are formed into a sheet by a compression operation, the sheet is heated with water vapor to react and cure the urethane prepolymer and the chips are mutually bonded to produce a sheet for forming a pad member. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing a sheet for forming a pad member used, for example, as an underwear pad or the like for a brassiere cup, for example, obtained by regenerating a polyurethane foam.

  In general, soft polyurethane foam has good cushioning properties, and has a soft and good feel without being used for a long time or repeated use. Therefore, underwear pads for shoulder pads, hangers, etc. It is widely used as clothing materials such as pads, sanitary materials such as disposable diapers and napkins, medical materials, and miscellaneous materials. The polyurethane foam (polyurethane foam) used for these specific applications is required to be white.

  As this type of material, for example, a hardly yellow-modified flexible polyurethane foam is known (see, for example, Patent Document 1). That is, the polyurethane foam is obtained by foaming a polyurethane raw material containing a polyol component and an isocyanate, and the polyol component contains a polyether polyol having an ester bond in the polyol skeleton. Examples of the polyether polyol include phthalic polyether polyol and maleic polyether polyol.

Moreover, the technique which suppresses yellowing of a polyurethane foam is also known (for example, refer patent document 2). That is, as the polyol, a polyether polyol having an ethylene oxide addition rate (polyoxyethylene unit) of less than 15 parts by mass in 100 parts by mass of the polyol is used, and the amount of the organotin catalyst used is 100 parts by mass of the polyol. It is set to be less than 0.1 parts by mass.
Re-published patent WO2002 / 053618 (page 2, page 4 and page 8) JP-A-2004-51795 (pages 2 and 6)

  In the hardly yellow-modified polyurethane foam described in Patent Documents 1 and 2, tolylene diisocyanate (TDI) is specifically used as a raw material polyisocyanate. For this reason, the polyurethane foam obtained has a structure having an aromatic ring in the chain of urethane bonds, and when irradiated with ultraviolet rays, a quinoid reaction occurs to produce an azo compound or a quinoneimide compound, which causes yellowing. It is remarkable. Such yellowing has been insufficiently improved only by changing the types and blending amounts of raw materials such as polyols and catalysts described in Patent Documents 1 and 2.

  On the other hand, white materials are often used in applications such as the above-described underwear pads and clothing materials, and consideration is given to minimizing discoloration such as yellowing. Furthermore, in order to improve ventilation when the underwear pad is worn and to improve the wearing feeling, an increase in ventilation is required. Therefore, in these applications, discoloration can be suppressed as much as possible, and at the same time, high air permeability is required.

  Then, the place made into the objective of this invention is providing the manufacturing method of the sheet | seat for pad member shaping | molding which can suppress discoloration and can improve air permeability.

  In order to achieve the above object, in the method for producing a pad member molding sheet according to claim 1, a polyurethane foam obtained by reacting an aliphatic polyisocyanate or an alicyclic polyisocyanate with a polyol is crushed. A urethane prepolymer having an isocyanate group obtained by reacting an aliphatic polyisocyanate or an alicyclic polyisocyanate with a polyol as a binder is added to the chip. And after compressing and shape | molding in a sheet form, it heats with water vapor | steam, the urethane prepolymer is reaction-hardened, and couple | bonds the said chips | tips.

  The pad member molding sheet manufacturing method according to claim 2 is characterized in that, in the invention according to claim 1, the addition amount of the urethane prepolymer is 7 to 20 parts by mass per 100 parts by mass of the chip.

  The pad member molding sheet manufacturing method according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the compression ratio at the time of compression is 1 to 3 times.

According to the present invention, the following effects can be exhibited.
In the manufacturing method of the sheet | seat for pad member shaping | molding of Claim 1, aliphatic polyisocyanate or alicyclic polyisocyanate reacts with a polyol, and the chip | tip formed by crushing the polyurethane foam obtained by making an aliphatic polyisocyanate as a binder is used. A urethane prepolymer having an isocyanate group obtained by reacting an isocyanate or an alicyclic polyisocyanate with a polyol is added. Since both the aliphatic polyisocyanate and alicyclic polyisocyanate forming these chips and binders do not have an aromatic ring that causes discoloration, discoloration of the resulting pad member molding sheet can be suppressed. . Furthermore, after compressing and forming into a sheet, the urethane prepolymer is heated and cured with water to cure the urethane prepolymer with water, etc., so that the chips are mainly bonded at the contact portion, and sufficient gaps are formed between the chips. The Therefore, the air permeability of the pad member molding sheet can be improved.

  In the method for producing a pad member molding sheet according to claim 2, since the addition amount of the urethane prepolymer is 7 to 20 parts by mass per 100 parts by mass of the chip, in addition to the effect of the invention according to claim 1, between the chips Bonding and void formation can be performed satisfactorily.

  In the manufacturing method of the pad member molding sheet according to claim 3, since the compression ratio at the time of compression is 1 to 3, in addition to the effect of the invention according to claim 1 or 2, while maintaining air permeability , Mechanical properties such as tensile strength and elongation can be improved.

In the following, embodiments that are considered to be the best of the present invention will be described in detail.
In the method for producing a pad member molding sheet of this embodiment, a urethane prepolymer having an isocyanate group is added as a binder to a chip formed by crushing a polyurethane foam. Here, the polyurethane foam is obtained by reacting aliphatic polyisocyanate or alicyclic polyisocyanate with a polyol, and the urethane prepolymer is obtained by reacting aliphatic polyisocyanate or alicyclic polyisocyanate with polyol. It is obtained. Next, after forming into a sheet by performing a compression operation, the urethane prepolymer is reacted and cured with water by heating with water vapor, and the pads are formed by bonding between the chips. .

  The chip is obtained by crushing a polyurethane foam produced by reacting an aliphatic or alicyclic polyisocyanate and a polyol in the presence of a catalyst, a foaming agent, a foam stabilizer, and the like. The polyurethane foam may be either soft or semi-rigid, but is preferably soft in order to use the pad member forming sheet as an underwear pad, clothing material, or the like. Here, the flexible polyurethane foam generally refers to a cell having a communication structure, flexibility, and resilience. As the polyisocyanate, an aliphatic or alicyclic polyisocyanate or a modified product thereof is used to suppress coloring of the polyurethane foam. As the modified product of the aliphatic polyisocyanate or the alicyclic polyisocyanate, an isocyanurate modified product, a prepolymer modified product, a biuret modified product, or the like is used. Polyisocyanate is a compound having a plurality of isocyanate groups.

  Specific examples of the aliphatic polyisocyanate include hexamethylene diisocyanate (HDI), lysine diisocyanate (LDI), butene diisocyanate (BDI), 1,3-butadiene-1,4-diisocyanate, octamethylene diisocyanate, lysine ester triisocyanate, Examples include 1,8-diisocyanate-4-isocyanate methyloctane, 1,6,11-undecane triisocyanate, 1,3,6-hexamethylene triisocyanate, and modified products thereof.

  Specific examples of the alicyclic polyisocyanate include isophorone diisocyanate (IPDI), dicyclohexylmethane diisocyanate, hydrogenated xylene diisocyanate (hydrogenated XDI), hydrogenated diphenylmethane diisocyanate (hydrogenated MDI), cyclohexyl diisocyanate (CHDI), Examples thereof include methylcyclohexyl diisocyanate, dicyclohexylmethane diisocyanate, bicycloheptane triisocyanate, and modified products thereof. Of these polyisocyanates, alicyclic polyisocyanates are preferred in that the mechanical properties of the polyurethane foam can be enhanced.

  As the polyol, polyether polyol, polyester polyol or the like is used. Examples of the polyether polyol include polypropylene glycol, polytetramethylene glycol, and modified products thereof. Polyester polyols include polycondensic acids such as adipic acid and phthalic acid as well as condensed polyester polyols obtained by polycondensation reaction with polyols such as ethylene glycol, diethylene glycol, propylene glycol, glycerin and trimethylolpropane, and lactones. Based polyester polyols and polycarbonate based polyols.

  The catalyst is for accelerating a reaction such as a urethanization reaction between a polyol and a polyisocyanate. Such catalysts include tertiary amines such as N, N ′, N′-trimethylaminoethylpiperazine, triethylenediamine, dimethylethanolamine, 1,8-diazabicyclo-5,4,0-undecene-7 (DBU), 1 An amine having an amidino group such as 1,5-diazabicyclo (4,3,0) nonene-5 (DBN), organometallic compounds such as tin octoate, acetates, alkali metal alcoholates and the like are used.

  The foaming agent is for foaming polyurethane into a polyurethane foam. As the foaming agent, pentane, cyclopentane, hexane, cyclohexane, dichloromethane, carbon dioxide, etc. are used in addition to water. As a raw material of the polyurethane foam, a silicone compound, a foam stabilizer such as a surfactant, a flame retardant such as a condensed phosphate ester, an antioxidant, a plasticizer, an ultraviolet absorber, a colorant and the like can be added.

  When the urethanization reaction between a polyol and a polyisocyanate is performed, a one-shot method or a prepolymer method is employed. The one-shot method is a method in which a polyol and polyisocyanate are directly reacted. The prepolymer method is a method in which a part of a polyol and a polyisocyanate is reacted in advance to obtain a prepolymer having an isocyanate group or a hydroxyl group at a terminal, and the polyol or polyisocyanate is reacted therewith.

  The polyurethane foam is produced by a slab molding method, a molding method, or the like. In the slab molding method, the reaction raw material (reaction mixture) mixed and stirred by the one-shot method is discharged onto a belt conveyor, and while the belt conveyor moves, the reaction raw material spontaneously foams at room temperature and atmospheric pressure and cures. It is obtained by doing. Thereafter, it is cured (cured) in a drying furnace and cut into a predetermined shape. The mold forming method is a method for producing a polyurethane foam by injecting a foam raw material (raw material mixture) into a molding recess of a mold, and clamping and reacting and foaming the raw material components in the mold. In this case, the heating temperature and heating time of the mold are, for example, 50 to 70 ° C. and 5 to 10 minutes.

  The polyurethane foam molded product (end material) thus obtained is crushed by a crushing machine when discarded after use, and is reused. The size of the chip is, for example, 5 to 20 mm. When the size of the chip is smaller than 5 mm, it is not preferable because it takes time for crushing by the crusher or crushing becomes difficult. On the other hand, when it is larger than 20 mm, a gap is easily formed between the chips, and the connection between the chips tends to be insufficient, which is not preferable.

Next, the binder will be described.
The binder reacts with water to generate a cured product and serves to bond the chips together. As the binder, as described above, an urethane prepolymer having an isocyanate group obtained by reacting an excess of aliphatic polyisocyanate, alicyclic polyisocyanate or a modified product thereof with a polyol is used. By using this urethane prepolymer, discoloration of the pad member forming sheet can be suppressed. As the aliphatic polyisocyanate or alicyclic polyisocyanate, each polyisocyanate listed as a raw material of the polyurethane foam forming the chip is used. In addition, as the modified product of the aliphatic polyisocyanate or the alicyclic polyisocyanate, an isocyanurate modified product, a biuret modified product, or the like is used.

  The urethane prepolymer reacts and cures with water such as water vapor, but triethylamine, stannic chloride, ammonium chloride and the like can be blended with the urethane prepolymer as a curing catalyst to promote the reaction and curing.

  The addition amount of the urethane prepolymer is appropriately determined depending on the size of the chip or the pad member forming sheet, and is preferably 7 to 20 parts by mass per 100 parts by mass of the chip. When the addition amount of the urethane prepolymer is less than 7 parts by mass, the binder is insufficient and the bonding between the chips tends to be insufficient, which is not preferable. On the other hand, when it exceeds 20 parts by mass, the urethane prepolymer becomes excessive and an excessive amount of urethane prepolymer remains in an unreacted state, and the resulting pad member molding sheet becomes too hard. It is not preferable because the physical properties deteriorate.

  Next, when manufacturing a pad member forming sheet, a liquid binder made of a urethane prepolymer is sprayed on the above-described chip using a known blender, and mixed and stirred. The chip with the binder attached is put into a mold and clamped, and compressed using a punching metal or the like so as to have a predetermined compression ratio. The compression ratio is determined by the apparent density and mechanical properties of the obtained pad member molding sheet, but is preferably about 1 to 3 times. If the compression ratio is less than 1, mechanical properties sufficient as a sheet material cannot be obtained. On the other hand, when it exceeds 3 times, the apparent density of the pad member forming sheet becomes too high, and it becomes impossible to reduce the weight, and the air permeability is lowered, and it tends to be too hard, which is not preferable. .

  Subsequently, water vapor is usually introduced into the mold for 1 to 5 minutes to heat the urethane prepolymer and to react with water and cure. Thereby, the reaction hardened | cured material of a urethane prepolymer is produced | generated, and between chips | tips is couple | bonded. Thereafter, by opening the mold and taking out the molded body, the intended pad member molding sheet can be produced.

In order to use the obtained sheet for forming a pad member as a material for an underwear pad or the like, it is desirable to have physical properties such as a predetermined apparent density, air flow rate, discoloration, tensile strength, and elongation. The apparent density measured in accordance with JIS K 7222 is preferably 45 to 110 kg / m ³ . When this apparent density is less than 45 kg / m ³ , the pad member forming sheet becomes too soft and the strength tends to be insufficient. On the other hand, when it exceeds 110 kg / m ³ , the pad member forming sheet becomes heavy and tends to be too hard. The air flow rate measured in accordance with JIS K 6400-7 is preferably 13 to 70 cm ³ / cm ² · sec. When the air flow rate is less than 13 cm ³ / cm ² · sec, when the pad member forming sheet is used for an underwear pad or the like, the air permeability becomes poor and sweat cannot be released sufficiently, resulting in a state of stuffiness. It becomes uncomfortable. On the other hand, when it exceeds 70 cm ³ / cm ² · sec, the air permeability is sufficient, but physical properties such as strength are deteriorated, which is not preferable.

Further, the discoloration (ΔYI) representing the color difference of the pad member molding sheet before and after leaving the pad member molding sheet for 2 hours in an acceleration tester having a temperature of 30 ° C., a humidity of 75%, and a NO ₂ gas concentration of 10 ppm is small. More specifically, ΔYI is more preferably 3.2 or less. When ΔYI is larger than 3.2, the discoloration property such as yellowing of the pad member forming sheet is increased, and it is not suitable as a material for an underwear pad or the like. The tensile strength measured according to JIS K 6400-5: 2004 is preferably 30 to 130 kPa. When the tensile strength is lower than 30 kPa, the strength of the pad member molding sheet is weak, and it is difficult to form the underwear pad and the like, and the shape retaining property of the underwear pad tends to deteriorate. On the other hand, when it is higher than 130 kPa, the flexibility becomes insufficient, and the underwear pad becomes too hard, which is not preferable. The elongation measured in accordance with JIS K 6400-5 is preferably 20 to 50%. When this elongation is less than 20%, when the underwear pad is formed from the pad member forming sheet, the underwear pad is less elastic and unpleasant to the touch. On the other hand, when it is larger than 50%, when the pad member forming sheet is used as an underwear pad, the deformation becomes large and the shape cannot be satisfactorily maintained, which is not preferable.

  The pad member forming sheet described above is used as a material for an underwear pad such as a brassiere cup and a brassiere inner, and molding into a predetermined shape for this purpose is performed according to a conventional method. For example, when a brassiere cup is formed, a heated press molding machine is used, and both the upper mold and the lower mold are heated to 180 ° C. and press molded at a pressure of 0.6 MPa. The brassiere cup thus obtained can be subjected to needle punching in order to further improve the air permeability.

  Now, the operation of the present embodiment will be described. When the end material of the polyurethane foam is reused, the urethane prepolymer is added as a binder to the chip obtained by crushing the polyurethane foam, and then compressed. To make water vapor act. At this time, the isocyanate group of the urethane prepolymer reacts with water (foaming reaction) to produce a urea compound, and the urea compound reacts with the isocyanate group of the urethane prepolymer (burette reaction) to produce a crosslinking reaction. Further, the isocyanate group of the urethane prepolymer reacts (allophanate reaction) with the urethane bond of the chip to generate a crosslinking reaction product. With these reactions, a reaction cured product is generated and the chips are bonded together.

  In this case, both the chip and the urethane prepolymer are formed of an aliphatic polyisocyanate or an alicyclic polyisocyanate with little discoloration, and do not have an aromatic ring that causes discoloration. The discoloration of the sheet is suppressed and the white color is maintained. In addition, by reacting and curing the urethane prepolymer by heating with water vapor, the chips are joined mainly at the contact parts, and sufficient gaps are formed in the non-contact parts between the chips, and air can be easily formed in the gaps. Can pass through.

The effects exhibited by the above embodiment will be described collectively below.
-In the manufacturing method of the pad member forming sheet of this embodiment, a crushed polyurethane foam obtained by reacting aliphatic polyisocyanate or alicyclic polyisocyanate that does not cause discoloration with polyol as a chip is used. . At the same time, a urethane prepolymer having an isocyanate group obtained by reacting an aliphatic polyisocyanate or alicyclic polyisocyanate that does not cause discoloration with a polyol as a binder is used. Therefore, it is possible to easily manufacture a pad member molding sheet in which discoloration is suppressed and air permeability is enhanced.

-By setting the addition amount of the urethane prepolymer to 7 to 20 parts by mass per 100 parts by mass of the chip, bonding between the chips and formation of voids can be favorably performed.
-By setting the compression ratio at the time of compression to 1 to 3, mechanical properties such as tensile strength and elongation can be improved while maintaining air permeability.

Hereinafter, the embodiment will be described more specifically with reference to examples and comparative examples, but the present invention is not limited to the scope of these examples.
(Examples 1 to 10 and Comparative Examples 1 and 2)
The polyurethane foam chip and binder shown below were used. A polyurethane foam chip was put into a blender, and the binder was sprayed and stirred to spray the binder onto the chip. Thereafter, the chip was put into a mold having a length of 400 mm, a width of 400 mm, and a height of 50 mm. The presence or absence of the skin layer in Table 1 is for the polyurethane foam forming the chip. The amount of the binder sprayed was set to parts by mass shown in Table 1 with respect to 100 parts by mass of the chip. Next, after compressing at a compression ratio shown in Table 1 using a punching metal, 100 ° C. water vapor was supplied into the mold for 2 minutes, the binder was reacted and cured, and particularly the contact portion between the chips was adhered. In this way, a polyurethane foam sheet was obtained. This sheet-like material had no surface wrinkles and had a clean surface state. And the sheet | seat for pad member shaping | molding was manufactured by slicing this to predetermined thickness. The thickness in Table 1 is the thickness of the pad member forming sheet after slicing. Here, in Comparative Examples 1 and 2, instead of bonding the chips with a binder, a soft slab foam block was peeled to form a sheet.

  Chip of polyurethane foam: 100 parts by mass of polyester polyol shown below, 63 parts by mass of isophorone diisocyanate as alicyclic polyisocyanate, 3.6 parts by mass of water as blowing agent, 1,8-diazabicyclo-5 as catalyst A polyurethane foam obtained by reacting and foaming 1.2 parts by mass of 4,0-undecene-7 and 1.5 parts by mass of silicone as a foam stabilizer to a size of 6 mm.

Polyester polyol: polyester polyol obtained by polycondensation of adipic acid, diethylene glycol, and trimethylolpropane, hydroxyl value 56 (mgKOH / g)
Urethane prepolymer as binder:
(A): A polyisocyanate obtained by reacting a part of hexamethylene diisocyanate with a polyol, the viscosity of which is adjusted with a plasticizer, the isocyanate group (—NCO) content is 21.8% by mass, and the viscosity is 2600 mPa · s. Manufactured by Asahi Kasei Chemicals Corporation, Duranate TKA-100
(B): Polyisocyanate obtained by reacting a part of hexamethylene diisocyanate with polyol, isocyanate group content 20.5% by mass, viscosity 380 mPa · s, manufactured by Asahi Kasei Chemicals Corporation, Duranate TSR-10
(C): Polyisocyanate obtained by reacting a part of isophorone diisocyanate with polyol, isocyanate group content is 11.8% by mass, manufactured by Sumitomo Bayer Urethane Co., Ltd., Desmodur Z4470 BA
And about the manufactured pad member shaping | molding sheet | seat, the apparent density, the air flow rate, the discoloration, tensile strength, and elongation were measured by the method shown below. The results are shown in Table 1.

Apparent density (kg / m ³ ): Measured according to JIS K 7222: 1999.
Ventilation rate (cm ³ / cm ² · sec): Measured according to JIS K 6400-7: 2004.

Discoloration: Measure the discoloration after leaving the pad member molding sheet for 2 hours in an accelerated tester with a temperature of 30 ° C., a humidity of 75%, and a NO ₂ gas concentration of 10 ppm, and the color of the pad member molding sheet before the test, The difference ΔYI was calculated.

Tensile strength (kPa): Measured according to JIS K 6400-5: 2004.
Elongation (%): Measured according to JIS K 6400-5: 2004.

表１に示したように、実施例１〜１０においては、チップ及びバインダーを形成するポリイソシアネートとして脂肪族ポリイソシアネート又は脂環族ポリイソシアネートをポリオールを使用したことから、変色性を表すΔＹＩを０．５３〜３．１８に抑えることができた。しかも、上記チップ間の接触部分をバインダーで結合させたことから、通気量を１５．５〜６０．５ｃｍ^３／ｃｍ^２・ｓｅｃに増加させることができた。なお、チップを形成するポリウレタン発泡体のスキン層の有無は、パッド部材成形用シートの通気量にはほとんど影響がなかった（実施例１と２との比較）。

As shown in Table 1, in Examples 1 to 10, since a polyol was used as an aliphatic polyisocyanate or an alicyclic polyisocyanate as a polyisocyanate forming a chip and a binder, ΔYI representing discoloration was 0. It was able to be suppressed to .53-3.18. Moreover, since the contact portion between the chips is bonded with a binder, the air flow rate can be increased to 15.5 to 60.5 cm ³ / cm ² · sec. The presence or absence of the polyurethane foam skin layer forming the chip had almost no effect on the air permeability of the pad member forming sheet (comparison between Examples 1 and 2).

  On the other hand, in Comparative Examples 1 and 2, since the soft slab foam block was peeled to form a sheet, there was originally no gap generated between the chips, and the air flow was a physical property value of the soft slab foam. It was a low result.

In addition, this embodiment can also be changed and embodied as follows.
-As said chip | tip, what was formed using aliphatic polyisocyanate and what was formed using alicyclic polyisocyanate can also be mixed and used.

  -As a urethane prepolymer of a binder, what was formed using aliphatic polyisocyanate and what was formed using alicyclic polyisocyanate can also be mixed and used.

  -As a binder, what blocked the isocyanate group of the urethane prepolymer can also be used. If comprised in this way, reaction with the water | moisture content in air can be suppressed and the pot life of a binder can be lengthened.

-It is also possible to mix | blend an oleic acid etc. with a binder as a reaction retarder which suppresses reacting with the water | moisture content in air before a urethane prepolymer reacts with water vapor | steam.
-As a binder, in addition to a urethane prepolymer, aliphatic polyisocyanate, alicyclic polyisocyanate, or those modified substances can also be used.

-The pad member forming sheet can be used for clothing materials such as shoulder pads and hanger pads, sanitary materials such as disposable diapers and napkins, medical materials, and miscellaneous materials.
Further, the technical idea that can be grasped from the embodiment will be described below.

  The pad member molding sheet according to any one of claims 1 to 3, wherein the pad member molding sheet is an underwear pad molding sheet. When comprised in this way, about the underwear pad shaping | molding sheet | seat, the effect of the invention which concerns on any one of Claims 1-3 can be exhibited most effectively.

The apparent density measured based on JISK7222: 1999 of the said sheet | seat for pad member shaping | molding is 45-110 kg / m < ³ >, The Claim 1 characterized by the above-mentioned. The manufacturing method of the sheet | seat for pad member shaping | molding of description. When comprised in this way, in addition to the effect of the invention which concerns on any one of Claims 1-3, the balance of the mechanical physical property of a pad member shaping | molding sheet | seat and lightweight can be aimed at.

The air flow rate measured in accordance with JIS K 6400-7: 2004 of the pad member molding sheet is 13 to 70 cm ³ / cm ² · sec. The manufacturing method of the sheet | seat for pad member shaping | molding as described in any one. When constituted in this way, in addition to the effect of the invention according to any one of claims 1 to 3, it is possible to sufficiently exhibit bonding between chips and improve air permeability.

  The pad member molding sheet according to any one of claims 1 to 3, wherein the polyisocyanate forming the chip and the urethane prepolymer is of the same type. In this case, in addition to the effects of the invention according to any one of claims 1 to 3, the compatibility between the chip and the urethane prepolymer can be increased, and the adhesion between the chips can be further improved. it can.

  ・ Obtained by reacting aliphatic polyisocyanate or alicyclic polyisocyanate with polyol as a binder on a chip obtained by crushing polyurethane foam obtained by reacting aliphatic polyisocyanate or alicyclic polyisocyanate with polyol Pad member molding characterized in that a urethane prepolymer having an isocyanate group is added and compressed to form a sheet, and then heated with water vapor to react and cure the urethane prepolymer to bond the chips together Sheet. According to this configuration, discoloration of the pad member forming sheet can be suppressed, and air permeability can be improved.

Claims (3)

It is obtained by reacting aliphatic polyisocyanate or alicyclic polyisocyanate with polyol as a binder on a chip obtained by crushing a polyurethane foam obtained by reacting aliphatic polyisocyanate or alicyclic polyisocyanate with polyol. For forming a pad member, comprising adding a urethane prepolymer having an isocyanate group, compressing and molding the sheet into a sheet, and then heating and curing the urethane prepolymer with steam to bond the chips together. Sheet manufacturing method. The method for producing a sheet for forming a pad member according to claim 1, wherein the amount of the urethane prepolymer added is 7 to 20 parts by mass per 100 parts by mass of the chip. The method for producing a pad member forming sheet according to claim 1 or 2, wherein a compression ratio at the time of compression is 1 to 3 times.