WO2020129806A1

WO2020129806A1 - Polyol composition for molding flexible polyurethane foam

Info

Publication number: WO2020129806A1
Application number: PCT/JP2019/048707
Authority: WO
Inventors: 石橋圭太; 吉井直哉
Original assignee: 東ソー株式会社
Priority date: 2018-12-21
Filing date: 2019-12-12
Publication date: 2020-06-25
Also published as: JP2024032914A

Abstract

To provide a polyol composition for molding a flexible polyurethane foam which has such a hardness distribution as to give a comfortable feeling when used as a cushion material; and a flexible polyurethane foam using the composition.　The above problem is solved by a polyol composition for molding a flexible polyurethane foam, said polyol composition comprising a polyol component (A), a catalyst (B), a foam stabilizer (C), a foaming agent (D) and a crosslinking agent (E), characterized in that a carbohydrate (E-1) is contained as the crosslinking agent (E) and the content of the carbohydrate (E-1) is 0.1-5 mass% relative to the polyol component (A).

Description

Polyol composition for molding flexible polyurethane foam

The present invention relates to a polyol composition for molding a flexible polyurethane foam and a flexible polyurethane foam using the composition.

Flexible polyurethane foams are widely used in daily necessities, automobile materials, clothing, sports/leisure products, medical materials, civil engineering materials, etc. In addition to the functions conventionally required for cushioning applications such as automobile seats and wheelchairs among such application fields, the hardness felt during initial compression when sitting and the occupant's waist and buttocks during lateral travel are also considered to be It is required to reduce the feeling of wobbling by tilting in the direction. In order to achieve these problems, it is necessary to more stably maintain the sitting posture by providing a hardness distribution in which the hardness of the flexible polyurethane foam is difficult to be expressed at the initial compression and the hardness is easily expressed at the time of high compression. ..

Various efforts have been made in the past as a means of expressing this hardness distribution. For example, a seat cushion structure having a laminated structure in which a highly elastic polyurethane foam is arranged in an upper layer (seat surface side) and a viscoelastic foam is arranged in a lower layer (bottom surface side) is disclosed (Patent Document 1). According to this, the lower layer side viscoelastic foam indirectly gives the occupant a soft fit through the upper layer side high elastic foam, and the upper layer high elasticity foam gives the occupant a cushioning feeling directly. Although the seating comfort is improved by these synergistic effects, there are problems such as an increase in the number of parts and an increase in the number of steps for integrating the foam by adhesion or the like. Further, a technique is disclosed in which the hardness distribution is expressed by changing the density of the sheet for each part (Patent Document 2). However, when the hardness is adjusted by changing the density, the density must be increased to increase the hardness, which leads to an increase in cost. In addition, it is necessary to perform molding for each part, which causes a problem of increasing man-hours. Further, the main polymerizable group (reactive group) of the crosslinking agent component contained in the polyol composition is an ethylene oxide group, by containing glycerin, and by controlling the shape of the foam cell, A technique for expressing hardness distribution even with the same density is disclosed (Patent Document 3). However, these factors alone are insufficient to develop the hardness distribution that reduces the hardness at the time of initial compression felt at the time of sitting and suppresses the wobble feeling.

Japanese Utility Model No. 6-19604 Japanese Patent Laid-Open No. 2002-300936 International Publication 2017/022824

The present invention has been made in view of the above background art, and a flexible polyurethane foam molding polyol composition having a hardness distribution that provides a comfortable sitting comfort when used as a cushioning material, and a flexible polyurethane foam using the composition. The purpose is to provide.

That is, the present invention includes the embodiments described below.

[1] A flexible polyurethane foam molding polyol composition comprising a polyol component (A), a catalyst (B), a foam stabilizer (C), a foaming agent (D), and a crosslinking agent (E), which comprises a crosslinking agent ( E) a saccharide (E-1) is contained, and the addition amount of the saccharide (E-1) is 0.1 to 5 mass% with respect to the polyol component (A). Polyol composition for molding polyurethane foam.

[2] The flexible polyurethane foam molding polyol composition according to the above [1], wherein the sugar (E-1) contains at least one selected from monosaccharides to decasaccharides.

[3] The flexible polyurethane foam molding polyol composition according to the above [1] or [2], wherein the average sugar chain number of the sugar (E-1) is 1.0 or more and 9.0 or less.

[4] A total degree of unsaturation of 0.001 to, which is produced by using at least one selected from a complex metal cyanide complex catalyst, a phosphazene catalyst, and an imino group-containing phosphazenium salt as a catalyst in the polyol component (A). 0.04 meq. /G of polyoxyalkylene polyol (A-1) is contained, The polyol composition for flexible polyurethane foam molding according to any one of the above [1] to [3].

[5] A flexible polyurethane foam molding composition comprising the flexible polyurethane foam molding polyol composition according to any one of the above [1] to [4] and a polyisocyanate component (F), wherein the polyisocyanate is The component (F) contains diphenylmethane diisocyanate in the range of 50 to 85% by mass, and the total amount of 2,2′-diphenylmethane diisocyanate and 2,4′-diphenylmethane diisocyanate contained in the diphenylmethane diisocyanate is equal to the total amount of the diphenylmethane diisocyanate. A flexible polyurethane foam molding composition, characterized in that it is 10 to 50 mass %.

[6] A flexible polyurethane foam obtained by reactively foaming the flexible polyurethane foam molding composition according to the above [5].

[7] A two-layer foam in which a flexible polyurethane foam molded such that the upper mold side is the lower surface and the lower mold side is the upper surface is cut out from the end surface on the upper surface side toward the lower surface side at every 45% of the thickness. The flexible polyurethane foam according to the above [6], wherein the hardness ratio of the foam on the upper surface side is 50 to 85% when the average value of the 25% compression hardness of the foam of each layer is 100.

[8] It is characterized in that the apparent density is 30 to 70 kg/m ³ , the 25% compression hardness of the skinned foam test piece is 100 to 350 N/314 cm ² , and the elongation is 100% or more. The flexible polyurethane foam according to the above [6] or [7].

[9] The flexible polyurethane foam according to any one of the above [6] to [8], which has a rebound resilience of 45 to 75% and a wet heat compression strain of less than 20%.

By using the polyol composition for molding a flexible polyurethane foam of the present invention, it is possible to obtain a flexible polyurethane foam having a hardness distribution that provides a comfortable sitting comfort when used as a cushioning material.

The present invention will be described in more detail.

The polyol composition for molding a flexible polyurethane foam according to the present invention contains the following polyol component (A), catalyst (B), foam stabilizer (C), foaming agent (D), and crosslinking agent (E).

The polyol component (A) is one that is polyadded with the polyisocyanate component (F) to form polyurethane, and in the present invention, it is at least one selected from the group consisting of polyether polyol and polyester polyol. desirable. Further, those having a number average molecular weight of 1,000 to 10,000 and a nominal number of functional groups of 2 or more are more desirable. When the number average molecular weight is less than the lower limit, the flexibility of the resulting foam tends to be insufficient, and when it exceeds the upper limit, the hardness of the foam tends to be lowered. Further, when the number of nominal functional groups is less than 2, there is a possibility that a problem such as deterioration of wet heat compression strain, which is an index of durability, may occur. Incidentally. The nominal number of functional groups refers to the theoretical average number of functional groups (the number of active hydrogen atoms per molecule), assuming that side reactions do not occur during the polymerization reaction of the polyol.

As the polyether polyol, for example, polypropylene ether polyol, polyethylene polypropylene ether polyol (hereinafter referred to as PPG), polytetramethylene ether glycol (hereinafter referred to as PTG), or the like can be used, and as the polyester polyol, for example, polycondensation can be used. Polyester polyols consisting of adipic acid and a diol, which are type polyester polyols, polycaprolactone polyols such as lactone polyester polyols, and the like can be used.

In the present invention, from the viewpoint of improving the durability of the foam, the polyol component (A) is produced by using at least one selected from a complex metal cyanide complex catalyst, a phosphazene catalyst, and an imino group-containing phosphazenium salt as a catalyst. The total unsaturation degree is 0.001 to 0.04 meq. /G of polyoxyalkylene polyol (A-1) is preferably contained. The increase in the total unsaturation degree of the polyol (A-1) means that the monool component having an unsaturated group at the terminal increases, and the total unsaturation degree is 0.04 meq. If it is larger than /g, the durability may be lowered as the cross-linking density of the foam is lowered. In addition, 0.001 meq. If it is less than /g, it takes a long time to produce the polyol, which is not preferable.

Further, in the present invention, a polyether polyol having a polyoxyalkylene chain composed of a copolymer of oxyethylene and oxypropylene in the polyol component (A) for the purpose of accelerating the foam breaking of the flexible polyurethane foam. It is preferable to include. The number average molecular weight of the polyether polyol is preferably 4,000 to 8,000, more preferably 6,000 to 8,000. Further, it is preferable that the number of nominal functional groups is 2 to 4. Further, the oxyethylene unit in the polyether polyol is preferably 60 to 90% by mass, more preferably 60 to 80% by mass. By setting the oxyethylene unit to 60 to 90% by mass, the hardness distribution of the foam can be easily obtained, and the durability can be further improved. From the viewpoint of storage stability at low temperatures, the copolymer composed of oxyethylene and oxypropylene is preferably a random copolymer.

The amount of the polyether polyol added is preferably 0.5 to 5 mass% with respect to the polyol component (A). If it is less than the lower limit, the moldability of the foam may deteriorate, and if it exceeds the upper limit, the elongation rate of the foam may decrease.

The polyol component (A) of the present invention is preferably used in combination with a polymer polyol obtained by polymerizing a vinyl monomer in the polyol by a usual method for the purpose of adjusting hardness. Examples of such a polymer polyol include those obtained by polymerizing a vinyl-based monomer in a polyalkylene polyol such as PPG in the presence of a radical initiator and stably dispersing it. Examples of the vinyl-based monomer include acrylonitrile, styrene, vinylidene chloride, hydroxyalkyl methacrylate and alkyl methacrylate, and of these, acrylonitrile and styrene are preferable. Examples of such polymer polyols include EL-910 and EL-923 manufactured by AGC, and FA-728R manufactured by Sanyo Kasei.

As the catalyst (B), 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 -Diaza-bicyclo[5.4.0]undecene-7,1,2-dimethylimidazole, dimethylethanolamine, N,N-dimethyl-N-hexanolamine, and their organic acid salts, stannas octoate, naphthene Organometallic compounds such as zinc oxide are also included. Further, amine catalysts having active hydrogen such as N,N-dimethylethanolamine and N,N-diethylethanolamine are also preferable.

The amount of the catalyst added is preferably 0.01 to 10 mass% with respect to the polyol component (A). If it is less than the lower limit, the curing tends to be insufficient, and if it exceeds the upper limit, the moldability may be deteriorated.

As the foam stabilizer (C), an ordinary surfactant is used, and an organosilicon-based surfactant can be preferably used. For example, Toray Dow Corning SZ-1327, SZ-1325, SZ-1336, SZ-3601, Momentive Y-10366, L-5309, Evonik B-8724LF2, B-8715LF2 and the like. Can be mentioned. The amount of these foam stabilizers added is preferably 0.1 to 3 mass% with respect to the polyol component (A).

Water is mainly used as the foaming agent (D). Water reacts with an isocyanate group to form a high-hardness urea group and generates carbon dioxide gas, which allows foaming. In addition to water, an optional foaming agent may be used. For example, a small amount of a low boiling point organic compound such as cyclopentane or isopentane may be used together, or air or nitrogen gas or liquefied carbon dioxide may be mixed and dissolved in the stock solution using a gas loading device to foam. The addition amount of the foaming agent is usually 0.5 to 10% by mass with respect to the polyol component (A), but 3.0 to 6 when a low density flexible polyurethane foam having an apparent density of less than 40 kg/m ³ is obtained. It is preferably 0% by mass, and more preferably 3.0 to 5.5% by mass. If it exceeds the upper limit, foaming may be difficult to stabilize, and if it is less than the lower limit, the density of the foam may not be sufficiently lowered.

The cross-linking agent (E) in the present invention contains a sugar (E-1). The saccharide (E-1) preferably contains at least one selected from monosaccharides to decasaccharides, and more preferably contains at least one selected from monosaccharides to hexasaccharides. The monosaccharide is the minimum unit of sugar, and the disaccharide to decasaccharide means each of 2 to 10 monosaccharides dehydrated and condensed to form a glycoside bond to form one molecule.

Among these, examples of monosaccharides include triose, tetrose, pentose, hexose, heptose, octose, nonose, and decose. These compounds may be aldose or ketose, and dialdose (a compound of a sugar derivative in which both ends of the carbon chain are aldehyde groups, for example, tetraacetylgalactohexodialdose, idhexodialdose, xylopentodose. Aldoses, etc.), monosaccharides having a plurality of carbonyl groups (such as aldol alkoketose such as othone and onose), monosaccharides having a methyl group (such as methyl sugars such as altromethylose), acyl groups (especially C2 such as acetyl group) -C4 acyl group and the like) (acetylose of the aldose, for example, acetyl body such as aldehyde glucose pentaacetyl compound), carboxyl group-introduced sugar (sugar acid or uronic acid), lyo sugar , Amino sugar, deoxy sugar and the like.

Such monosaccharides include, for example, tetrose (erythrose, threorose, etc.), pentose (arabinose, ribose, lyxose, deoxyribose, xylose, etc.), hexose (allose, altrose, glucose, mannose, gulose, idose, galactose, Fructose, sorbose, fucose, rhamnose, talose, galacturonic acid, glucuronic acid, mannuronic acid, glucosamine, etc.) and the like.

Also, the monosaccharide may be a cyclic isomer having a cyclic structure formed by a hemiacetal bond. The monosaccharide does not have to have optical activity and may be any of D type, L type and DL type. Further, it may be a crystal or a liquid, and may be a hydrate or may contain water. These monosaccharides can be used alone or in combination of two or more. In particular, isomerized liquid sugars that are liquid at room temperature, such as high-fructose liquid sugar, fructose-glucose liquid sugar, glucose-fructose liquid sugar, workability during preparation of the flexible polyurethane foam molding polyol composition, and soft polyurethane foam molding polyol composition It is more preferable in terms of storage stability.

Examples of disaccharides include trehalose (for example, α,α-trehalose, β,β-trehalose, α,β-trehalose, etc.) cozybiose, nigerose, maltose, isomaltose, sophorose, laminaribiose, cellobiose, gentiobiose, lactose. , Sucrose, palatinose, melibiose, rutinose, primeverose, turanose and the like. These monosaccharides and disaccharides can be used alone or in combination of two or more kinds, but as described above, a room temperature liquid mixture of sugars that are liquid at room temperature and a room temperature liquid mixture with a hydrophilic polyol such as ethylene glycol, diethylene glycol or glycerin. It is more preferable to use as.

Trisaccharides to decasaccharides are also generally called oligosaccharides (hereinafter, the trisaccharides to decasaccharides may be referred to as oligosaccharides). Homo-oligosaccharides in which 3 to 10 molecules of monosaccharides are dehydrated and condensed via glycoside bonds. And, at least two or more kinds of 3 to 10 molecules of monosaccharides and/or sugar alcohols are roughly classified into hetero-oligosaccharides dehydrated and condensed via glycoside bonds. The oligosaccharides that can be used in the present invention are preferably trisaccharides to decasaccharides, and more preferably trisaccharides to hexasaccharides. In addition, these oligosaccharides may have a cyclic structure, and may be an anhydride or a hydrate. Further, in the oligosaccharide, a monosaccharide and a sugar alcohol may be bound to each other. These oligosaccharides can be used alone or in combination of two or more, and can also be used in combination with monosaccharides, disaccharides and polysaccharides. The oligosaccharide may be an oligosaccharide composition composed of a plurality of sugar components. Even such an oligosaccharide composition may be simply referred to as an oligosaccharide. Regarding oligosaccharides, those that are solid at room temperature are preferably used after being liquefied at room temperature by mixing with other sugars or hydrophilic polyols such as glycerin.

Examples of the trisaccharides include homooligosaccharides such as maltotriose, isomaltotriose, panose, and cellotriose; manninotriose, solatriose, melezitose, planteose, gentianose, umbelliferose, lactosucrose, raffinose and the like. To be

Examples of tetrasaccharides include homooligosaccharides such as maltotetraose and isomalttetraose; heterooligosaccharides such as stachyose, cellotetraose, scorodose, liquinose, and telolaose having sugar or sugar alcohol attached to the reducing end of panose.

Examples of pentasaccharides include homooligosaccharides such as maltopentaose and isomaltopentaose; and heterooligosaccharides such as pentaose in which a disaccharide is bonded to the reducing end of panose.

Examples of hexasaccharides include homo-oligosaccharides such as maltohexaose and isomalthexaose.

Examples of cyclic oligosaccharides include α-cyclodextrin (hexasaccharide), β-cyclodextrin (heptasaccharide), and γ-cyclodextrin (octasaccharide).

Oligosaccharide may be a reduced type (maltose type) or a non-reduced type (trehalose type).

Examples of polysaccharides include amylose, amylopectin, glycogen, cellulose, agar, inulin, glucomannan, glycosaminoglycan (mucopolysaccharide), alginic acid, hyaluronic acid, chondroitinic acid, heparin and chitin.

Monosaccharides, disaccharides, oligosaccharides and mixtures thereof have ether-modified or ester-modified a part of their hydroxyl groups for the purpose of improving the compatibility with other components of the polyol molding composition and the sugar. May be. However, since the effect of the present invention is reduced due to the reduction of the hydroxyl group concentration due to the modification, the modifiable hydroxyl groups are preferably 30 mol% or less of all the hydroxyl groups.

The number average molecular weight of the sugar (E-1) is preferably 180 to 2,500, more preferably 180 to 1,800. If it exceeds the upper limit, foam formability and foam elongation may deteriorate.

The average number of sugar chains of the carbohydrate (E-1) is preferably 1.0 or more and 9.0 or less, more preferably more than 1.0 and 9.0 or less, and most preferably 1.5 or more. It is 9.0 or less. Here, the number of sugar chains is the number of linked monosaccharides, and the average number of sugar chains is the average number of sugar chains of each component contained in the sugar (E-1). If it is less than the lower limit, it is difficult to obtain a sufficient elongation, and if it exceeds the upper limit, the formability of the foam and the elongation of the foam may be deteriorated.

Also, the average number of hydroxyl groups in the sugar (E-1) is preferably 0.5 times or more the average number of carbon atoms. Here, the average number of hydroxyl groups is the average number of hydroxyl groups of each component in the sugar (E-1), and the average number of carbon atoms is the carbon number of each component in the sugar (E-1). It is the average of the number of atoms.

The amount of the sugar (E-1) added is 0.1 to 5% by mass, preferably 0.1 to 4% by mass, more preferably 0.3 to 4% by mass based on the polyol component (A). It is% by mass. If it is less than the lower limit, it is difficult to obtain the effect of expressing the hardness distribution, and if it exceeds the upper limit, the formability of the foam and the elongation rate of the foam may be deteriorated.

In addition, in the present invention, from the viewpoint of improving physical properties such as foam elongation and wet heat compression strain, an alicyclic glycol is used as a crosslinking agent component other than the sugar (E-1) in the polyol composition for molding a flexible polyurethane foam. And at least one cyclic glycol selected from the group consisting of aromatic glycols (hereinafter also simply referred to as “cyclic glycol”). The cyclic glycol is a compound having a ring structure, and examples thereof include cyclohexanediol, cyclohexanedimethanol, hydroquinone bis(2-hydroxyethyl)ether, dihydroxydiphenylmethane, bisphenol A hydride, polyoxyethylene bisphenol ether, and polyoxyethylene bisphenol ether. Examples thereof include oxypropylene bisphenol ether. Among these, 1,4-cyclohexanedimethanol and polyoxyethylene bisphenol A ether are preferable from the viewpoint that the resulting flexible polyurethane foam has a high effect of improving the wet heat compression strain. The content of the cyclic glycol is preferably 1.5 to 8% by mass, and more preferably 1.5 to 6% by mass based on the polyol component (A).

By using the above polyol composition containing the polyol component (A), the catalyst (B), the foam stabilizer (C), the foaming agent (D), and the cross-linking agent (E), sitting when used as a cushioning material It is possible to obtain a flexible polyurethane foam having a comfortable feeling and a hardness distribution in the vertical direction.

The polyisocyanate component (F) used for producing the flexible polyurethane foam of the present invention includes 4,4′-diphenylmethane diisocyanate (hereinafter, 4,4′-MDI) and 2,4′-diphenylmethane diisocyanate (hereinafter, 2,4). Diphenylmethane diisocyanate (hereinafter, MDI) such as'-MDI), 2,2'-diphenylmethane diisocyanate (hereinafter, 2,2'-MDI), polyphenylene polymethylene polyisocyanate (hereinafter, P-MDI) is used as an isocyanate source. It is preferable. In the present invention, various modified products such as the above-mentioned MDI, a mixture of MDI and P-MDI, a urethane modified product, a urea modified product, an allophanate modified product, a nurate modified product, and a burette modified product may be used.

The MDI content of the polyisocyanate component (F) according to the present invention is preferably in the range of 50 to 85 mass %. If the MDI content exceeds 85% by mass, the storage stability of the polyisocyanate component at low temperatures and the durability of the resulting flexible polyurethane foam may decrease, while if it is less than 50% by mass, the crosslinking density increases, The elongation of the flexible polyurethane foam may decrease, and it may be difficult to obtain sufficient foam strength.

Furthermore, the sum of the content of 2,2'-MDI and the content of 2,4'-MDI (hereinafter referred to as isomer content) is preferably 10 to 50% by mass with respect to the total amount of MDI.

If the content of 2,2'-MDI and 2,4'-MDI with respect to the total amount of MDI according to the present invention is less than 10% by mass, the storage stability of the polyisocyanate component at low temperatures may be impaired, and the isocyanate storage location It may be necessary to constantly heat pipes, piping, and foam molding machines. In addition, the molding stability of the flexible polyurethane foam may be impaired, and foam collapse may occur during foaming. On the other hand, if it exceeds 50% by mass, the reactivity is lowered, and there is a possibility that problems such as extension of the molding cycle, increase of the closed cell ratio of the foam and shrinkage after molding may occur.

Then, in the production of the flexible polyurethane foam in the present invention, fillers such as calcium carbonate and barium sulfate, flame retardants, plasticizers, colorants, known various additives such as antifungal agents, and auxiliaries as necessary. Can be used.

In the present invention, a flexible polyurethane foam can be obtained from the above polyol composition for molding a flexible polyurethane foam and the polyisocyanate component, and has an apparent density of 30 kg/m ³ to 70 kg/m ³ and a skin test piece of 25. A soft polyurethane foam having a% compression hardness of 100 to 350 N/314 cm ² , an elongation of 100% or more, a rebound resilience of 45 to 75%, and a wet heat compression strain of less than 20% and having a hardness distribution in the foaming direction is suitable. Can be obtained.

Next, a method for producing the flexible polyurethane foam of the present invention will be described.

The flexible polyurethane foam of the present invention reacts with a mixed solution of a polyol component (A), a catalyst (B), a foam stabilizer (C), a foaming agent (D), a crosslinking agent (E), and a polyisocyanate component (F). It is manufactured by foaming.

The molar ratio (NCO/active hydrogen) at the time of mixed foaming of all the isocyanate groups in the polyisocyanate composition of the present invention and all the active hydrogen groups in the active hydrogen group-containing compound containing water is 0.7 to 1 .4 (isocyanate index (NCO INDEX)=70 to 140) is preferable, and 0.7 to 1.2 (NCO INDEX=70 to 120) is more preferable as the range of foam durability and molding cycle. ..

When NCO INDEX is less than 70, durability is lowered and foaming property is excessively increased, and when it is more than 120, the unreacted isocyanate remains for a long time to extend the molding cycle and delay the high molecular weight during foaming. Foam collapse may occur.

As a method for producing a flexible polyurethane foam, a mixed liquid of the polyol component (A), the catalyst (B), the foam stabilizer (C), the foaming agent (D), the crosslinking agent (E), and the polyisocyanate component (F) is used. The method for producing a flexible polyurethane mold foam (hereinafter, soft mold foam), which comprises injecting the undiluted foaming solution into a mold and then foaming and curing the same can be used.

The mold temperature at the time of injecting the foaming stock solution into the mold is usually 30 to 80° C., preferably 45 to 65° C. If the mold temperature at the time of injecting the above foaming undiluted solution into the mold is less than 30° C., the production cycle is prolonged due to a decrease in reaction rate, while if it is higher than 80° C., the reaction between the polyol and the isocyanate is If the reaction between water and isocyanate is excessively promoted, the foam may collapse during foaming.

The curing time for foaming and curing the above-mentioned foaming undiluted solution is preferably 10 minutes or less, more preferably 7 minutes or less, in consideration of a general flexible mold foam production cycle.

When manufacturing a soft mold foam, the above components can be mixed using a high-pressure foaming machine, a low-pressure foaming machine, etc., as in the case of a normal soft mold foam.

It is preferable to mix the isocyanate component and the polyol component immediately before foaming. Other components can be mixed in advance with the isocyanate component or the polyol component as long as they do not affect the storage stability of the raw material or the change with time of the reactivity. The mixture may be used immediately after mixing, or may be used in an appropriate amount after storage. In the case of a foaming device capable of simultaneously introducing more than two components into the mixing section, it is also possible to individually introduce a polyol, a foaming agent, an isocyanate, a catalyst, a foam stabilizer, an additive and the like into the mixing section.

The mixing method may be either dynamic mixing for mixing in the machine head mixing chamber of the foaming machine or static mixing for mixing in the liquid feed pipe, or both may be used together. In many cases, mixing of a gaseous component such as a physical foaming agent and a liquid component is performed by static mixing, and mixing of components that can be stably stored as a liquid is performed by dynamic mixing. The foaming device used in the present invention is preferably a high-pressure foaming device that does not require solvent cleaning of the mixing section.

　The mixed solution obtained by such mixing is discharged into the mold, foamed and cured, and then demolded. In order to smoothly perform the above mold release, it is also preferable to apply a mold release agent to the mold in advance. As the releasing agent to be used, a releasing agent usually used in the field of molding and processing may be used.

The product after demolding can be used as it is, but it is preferable to break the cell membrane of the foam under compression or under reduced pressure by a conventionally known method to stabilize the appearance and dimensions of the product thereafter.

According to the above-mentioned method for producing a flexible polyurethane foam, an apparent density of 30 kg/m ³ to 70 kg/m ³ and a 25% compression hardness of the skin-attached foam test piece are 100 to 350 N/314 cm ² , and the impact resilience is 45 to 75%. A flexible polyurethane foam having a wet heat compression strain of less than 20% can be obtained. Further, the flexible polyurethane foam has a hardness distribution in the foaming direction.

[Mechanism of flexible polyurethane foam exhibiting hardness distribution]
The mechanism by which the flexible polyurethane foam according to the present invention exhibits a hardness distribution will be described. For example, a flexible polyurethane foam used as a cushion material is molded in a mold so that the lower mold side is the upper surface and the upper mold side is the lower surface. Therefore, in the flexible polyurethane foam, the upper surface is first formed in the mold, and after the volume expansion due to foaming, the lower surface is finally formed. When the foam is formed on the upper surface side, the saccharides associate with water to delay the reaction between water and isocyanate, and suppress the formation of high hardness urea bond. On the other hand, from the core layer portion formed by the high temperature reaction, it is considered that the urea bond is concentrated and generated on the lower surface side, so that the hardness is increased and the hardness distribution is developed.

The flexible polyurethane foam produced as described above not only has excellent physical properties such as hardness and impact resilience, but also has a hardness distribution in which the hardness increases from the upper surface side to the lower surface side, and therefore has excellent riding comfort. It becomes possible to provide it as a cushion material.

Hereinafter, the present invention will be described more specifically based on Examples and Comparative Examples, but the present invention is not limited to the following Examples. In addition, "part" and "%" in the text are based on mass unless otherwise specified.

[Preparation of polyol composition]
(Examples 1 to 15, Comparative Examples 1 to 6)
After replacing the reactor equipped with a stirrer, a cooling pipe, a nitrogen introduction pipe, and a thermometer with nitrogen, 700 g of polyol 1, 300 g of polyol 3, 15 g of polyol 4, 15 g of crosslinking agent 1, 20 g of crosslinking agent 11 and a catalyst were used. 1 g, 8.0 g of catalyst 2, 2.0 g of catalyst 2, 10 g of foam stabilizer 1 and 36 g of water were charged, and the mixture was stirred at 23° C. for 0.5 hours to obtain a polyol composition (P-1). Other polyol compositions (P-2 to P-21) were prepared in the same manner as P-1.

Of the raw materials shown in Tables 1 to 4, the liquid temperature of the mixture (polyol composition) of all raw materials other than the polyisocyanate component was adjusted to 24°C to 26°C, and the polyisocyanate component was adjusted to the liquid temperature of 24°C to 26°C. did. A predetermined amount of polyisocyanate component was added to the polyol composition, mixed for 7 seconds with a mixer (7,000 rpm), and then poured into a mold to foam a flexible polyurethane foam. Then, it was taken out from the mold and the physical properties of the obtained flexible polyurethane foam were measured. The NCO Index in Tables 1 to 4 is the ratio of NCO groups to the number of active hydrogen atoms present in the formulation.

[Bubbling conditions]
Mold temperature: 60-70℃
Mold shape: 300mm×300mm×100mm
Mold material: Aluminum Cure time: 5 minutes

[Raw materials used]
-Polyol 1: average number of functional groups = 3.0, hydroxyl value = 24 (mgKOH/g), terminal primary conversion rate = 84%, oxyethylene unit = 14.6 mass%, total unsaturation degree 0.03 meq. /G of polyoxyethylene polyoxypropylene polyol, Tosoh NEF-693
-Polyol 2: average number of functional groups = 3.0, hydroxyl value = 24 (mgKOH/g), terminal primary conversion rate = 79%, oxyethylene unit = 14.0 mass%, total unsaturation degree 0.19 meq. /G of polyoxyethylene polyoxypropylene polyol, NEF-728 manufactured by Tosoh Corporation
-Polyol 3: Polymer polyol having an average number of functional groups of 3.0 and a hydroxyl value of 24 (mgKOH/g), Exenol EL-923 manufactured by AGC Co.
Polyol 4: polyether polyol having an average number of functional groups of 3.0, a hydroxyl value of 24 (mgKOH/g), and an oxyethylene unit of 70% by mass, NEF-729 manufactured by Tosoh Corporation.
Polyol 5: polyoxyethylene polyoxypropylene polyol having an average number of functional groups of 4.0, a hydroxyl value of 28 (mgKOH/g), and an oxyethylene unit of 80% by mass, NEF-024 manufactured by Tosoh Corporation.
Polyol 6: Polyoxyethylene polyoxypropylene polyol having an average number of functional groups of 4.0, a hydroxyl value of 28 (mgKOH/g), and an oxyethylene unit of 90% by mass, NEF-730 manufactured by Tosoh Corporation.
・Crosslinking agent 1: D-(+)-glucose (Fujifilm Wako Pure Chemical Industries, monosaccharide)
-Crosslinking agent 2: D-(-)-fructose (manufactured by Tokyo Chemical Industry Co., Ltd., monosaccharide)
-Crosslinking agent 3: D-(+)-sucrose (Tokyo Chemical Industry Co., Ltd., disaccharide)
-Crosslinking agent 4: D-(+)-raffinose (Tokyo Chemical Industry Co., Ltd., trisaccharide)
-Crosslinking agent 5: high-fructose corn syrup (manufactured by Japan Food Processing Co., mixture of monosaccharides to decasaccharides)
-Crosslinking agent 6: γ-cyclodextrin (Tokyo Chemical Industry Co., Ltd., octasaccharide)
Cross-linking agent 7: Maltose syrup (manufactured by Japan Food Processing Co., mixture of monosaccharides to decasaccharides)
-Crosslinking agent 8: Purified glycerin (manufactured by Sakamoto Yakuhin Kogyo Co., Ltd.)
-Crosslinking agent 9: trimethylolpropane (manufactured by Mitsubishi Gas Chemical Company)
-Crosslinking agent 10: diethanolamine (manufactured by Mitsui Chemicals, Inc.)
-Crosslinking agent 11: PEG200 (manufactured by Sanyo Chemical Industries, polyethylene glycol, number average molecular weight 200)
-Crosslinking agent 12: CHDM-D (1,4-cyclohexanedimethanol, manufactured by EASTMAN CHEMICAL, alicyclic glycol)
-Catalyst 1: 2-hydroxymethyltriethylenediamine (manufactured by Tosoh Corporation, trade name: R-ZETA HD)
-Catalyst 2: N,N,N'-trimethyl-N'-hydroxyethyl-bisaminoethyl ether (manufactured by Tosoh Corporation, trade name: TOYOCAT RX-10)
・Foam stabilizer 1: Silicone-based foam stabilizer (manufactured by Evonik, brand name: B-8715LF2)
Isocyanate 1: Polyphenylene polymethylene polyisocyanate having an MDI content of 85% by mass and an isomer content of 38% by mass (manufactured by Tosoh Corporation, trade name: CEF-550).

[Moldability evaluation]
In each table, the evaluation of moldability "○" means that the urethane foam does not have a collapse that greatly sinks after reaching the maximum height and the phenomenon that the generated urethane foam shrinks immediately after foaming or after curing does not occur. This means that the polyurethane foam could be molded, and the evaluation of “x” means that the urethane foam had phenomena such as collapse and shrinkage.

[Apparent density]
It was determined by the method described in JIS K6400.

[25% compression hardness (25% ILD) of test piece foam with skin]
It was determined by the B method described in JIS K6400.

[Rebound resilience]
It was measured by the method described in JIS K6400.

[Heat compression strain]
It was measured by the method described in JIS K6400.

[Growth rate]
It was measured by the method described in JIS K6400.

[About hardness distribution in the height direction of flexible polyurethane foam]
The hardness distribution measurement sample of the present invention is a flexible polyurethane foam molded with a thickness of 100 mm so that the upper mold side is the lower surface and the lower mold side is the upper surface, and cut from the end surface on the upper surface side toward the lower surface side every 45 mm. In addition, the two-layer foam is “upper surface side: 0 mm (upper surface end) to 45.0 mm, lower surface side: 45.0 mm to 90.0 mm”.
For each of the above-mentioned two-layer evaluation samples, first, the evaluation sample was compressed until the stress received by the pressure plate became 0.98 N, and this position was set to the initial position of the pressure plate where the thickness of the evaluation sample was 100%. And The pressure plate is a disc having a diameter of 200 mm. Next, the pressure plate is compressed toward the evaluation sample at a speed of 50 mm/min to 25% of the thickness of the evaluation sample. After that, the pressure plate is returned to the initial position at a speed of 50 mm/min. In the above process, when the evaluation sample was compressed and deformed by 25%, the stress value exerted on the evaluation sample was measured, and this value was defined as 25% compression hardness.

Then, the ratio of the hardness of each evaluation sample when the average value of the 25% compression hardness of the evaluation samples of each of the two layers was set to 100 was calculated. That is, this hardness ratio means the hardness ratio of each evaluation sample to the average hardness in the foaming height direction.
If the hardness ratio of the upper surface side foam is 50 to 85% when the average value of the 25% compression hardness of the evaluation samples of each of the two layers is 100, it can be said that the foam has a hardness distribution.

[Urea binding ratio calculation method]
FT-IR measurement is performed on the above-mentioned two-layer evaluation sample, and the peak height derived from the urea bond observed near the wave number of 1660 cm ⁻¹ is divided by the peak height derived from the urethane bond observed near the wave number of 1710 cm ^−1. The urea binding ratio was calculated by. That is, the smaller the urea bond ratio, the more suppressed the generation of urea bonds and the harder it is to develop hardness.

[Anisotropy (shape) of cells of flexible polyurethane foam]
The measurement sample of the cell anisotropy in the present invention is a flexible polyurethane foam molded with a thickness of 100 mm, which is a four-layer foam "first layer" cut out every 22.5 mm from the end face on the upper surface side to the lower surface side. 0 mm (upper end) to 22.5 mm, second layer: 22.5 mm to 45 mm, third layer: 45 mm to 67.5 mm, fourth layer: 67.5 mm to 90 mm”. The first to fourth layers were divided into four layers. Each of the obtained layers was divided into two equal parts in the vertical direction, and an enlarged image of the central portion (field of view: 3.2 mm×3.2 mm) of the cross section was obtained by a microscope. When looking at the acquired image from the bottom to the top in the foaming direction, randomly select 30 foam cells from the image to determine the cell length in the foaming direction and the cell length orthogonal to the foaming direction. It was measured. A value obtained by dividing the cell length in the foaming direction by the cell length orthogonal to the foaming direction was obtained for each cell, and the average value of 30 cells was used as the evaluation value of the cell anisotropy. The closer the anisotropy value is to 1, the closer the cell shape becomes to the spherical shape, the smaller the value, the longer the horizontal direction to the foaming direction, and the larger the value, the longer the vertical direction to the foaming direction. In this example, measurement was performed using Example 1 and Comparative Example 3 as representative examples.

As shown in Comparative Examples 1 to 5 in Table 4, when the sugar (E-1) is not used as the cross-linking agent, the hardness distribution is extremely small or does not appear. In these cases, the urea bond ratio on the upper surface side is higher and the urea bond ratio on the lower surface side is lower than in the examples. Further, since there is no correlation between the cell anisotropy and the hardness distribution ratio, it cannot be said that the hardness distribution is exhibited by controlling the cell anisotropy. As shown in Comparative Example 6, even when the sugar (E-1) was used as a cross-linking agent, when the amount used was too large relative to the specified amount, the molding stability of the foam was remarkably reduced, and the foam was molded. Can not do it. By comparing the above Examples and Comparative Examples, in the present invention, it is clear that a molded product having a favorable hardness distribution with good sitting comfort when used as a cushioning material and having preferable physical properties can be obtained. Yes, it is possible to understand the significance and outstanding excellence of the configuration of the present invention.

Although the present invention has been described in detail and with reference to particular embodiments, it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the spirit and scope of the invention.

In addition, Japanese patent application 2018-239669 filed on December 21, 2018, Japanese patent application 2019-027120 filed on February 19, 2019, and Japanese patent filed on August 29, 2019 The entire contents of the specification, claims, and abstract of the application 2019-156884 are incorporated herein by reference and are incorporated as the disclosure of the specification of the present invention.

Claims

A polyol composition for molding a flexible polyurethane foam, comprising a polyol component (A), a catalyst (B), a foam stabilizer (C), a foaming agent (D), and a cross-linking agent (E), which is used as the cross-linking agent (E). Flexible polyurethane foam molding containing a sugar (E-1) and the addition amount of the sugar (E-1) is 0.1 to 5 mass% with respect to the polyol component (A). Polyol composition.
The flexible polyurethane foam molding polyol composition according to claim 1, wherein the sugar (E-1) contains at least one selected from monosaccharides to decasaccharides.
The polyol composition for molding a flexible polyurethane foam according to claim 1 or 2, wherein the average number of equal chains of the sugar (E-1) is 1.0 or more and 9.0 or less.
A total degree of unsaturation of 0.001 to 0.04 meq produced by using at least one selected from a complex metal cyanide complex catalyst, a phosphazene catalyst, and an imino group-containing phosphazenium salt as a catalyst in the polyol component (A). ． 4. The flexible polyurethane foam molding polyol composition according to claim 1, wherein the polyoxyalkylene polyol (A-1)/g is included.
A flexible polyurethane foam molding composition comprising the flexible polyurethane foam molding polyol composition according to any one of claims 1 to 4 and a polyisocyanate component (F), wherein the polyisocyanate component (F) comprises: Diphenylmethane diisocyanate is contained in the range of 50 to 85% by mass, and the total amount of 2,2'-diphenylmethane diisocyanate and 2,4'-diphenylmethane diisocyanate contained in the diphenylmethane diisocyanate is 10 to 50% by mass with respect to the total amount of the diphenylmethane diisocyanate. A composition for molding a flexible polyurethane foam, characterized in that
A flexible polyurethane foam obtained by reacting and foaming the flexible polyurethane foam molding composition according to claim 5.
A soft polyurethane foam molded so that the upper mold side is the lower surface and the lower mold side is the upper surface is cut out from the end surface of the upper surface side toward the lower surface side at a rate of 45% for each of the two layers of foam. 7. The flexible polyurethane foam according to claim 6, wherein the hardness ratio of the foam on the upper surface side is 50 to 85% when the average value of the 25% compression hardness of the foam is 100.
Claims characterized in that the apparent density is 30 to 70 kg/m 3 , the 25% compression hardness of the skinned foam test piece is 100 to 350 N/314 cm 2 , and the elongation is 100% or more. Item 6. The flexible polyurethane foam according to Item 6 or 7.
9. The flexible polyurethane foam according to any one of claims 6 to 8, which has a rebound resilience of 45 to 75% and a wet heat compression strain of less than 20%.