JP4688055B2 - Method for producing flexible polyurethane foam for heating carpet - Google Patents

Description

  The present invention relates to a method for producing a flexible polyurethane foam for a heating carpet. More specifically, the present invention relates to a method for producing a flexible polyurethane foam for a heating carpet by integral molding of a surface material, which achieves both filling properties and curing properties and is excellent in productivity and physical properties.

  In recent years, there has been a growing demand for heating carpets represented by electric carpets to provide comfort, such as sitting comfort, walking comfort, and sound insulation, as well as natural heating functions, and further increase production efficiency. Conventional electric carpets are manufactured by attaching a felt material as a surface material, a heating element, and a heat insulating material through an adhesive or an adhesive sheet, and have problems such as insufficient cushioning, heavy weight, and a large number of manufacturing processes. It was. On the other hand, a method of using a foam such as a synthetic resin sheet or polyurethane for an electric carpet or a health warmer is also disclosed. For example, Patent Document 1 proposes to use a flexible urethane foam as a surface layer for providing cushioning properties. Patent Document 2 proposes a structure in which foams such as soft urethane, soft vinyl chloride resin, and SBR are infiltrated into the entire fibers on the front and back surfaces for the purpose of improving cushioning properties and strength. Further, Patent Document 3 discloses that a flexible polyurethane foam, a polyethylene foam, a polyvinyl chloride foam, or the like is used for a health warmer in consideration of imparting flexibility and elasticity.

JP 60-49590 A JP 61-173030 A JP 59-57469 A

  According to the present invention, there is provided a method for producing a flexible polyurethane foam for a heating carpet by integral molding of a surface material, which achieves both a filling property and a curing property by adjusting a gelation rate and a rise rate, and is excellent in productivity and physical properties. It becomes possible to provide.

  In general, molding of a thin flexible polyurethane foam such as for heating carpets makes it difficult to satisfy both the filling property of the reaction mixture and the curing property. That is, if the curing property is improved with the aim of improving the productivity, a problem of lack of thickness is likely to occur. On the other hand, if the fillability is improved with the aim of preventing missing parts, the productivity tends to be lowered.

  The present invention has been studied in order to solve the above-mentioned problems, and is intended to achieve both filling properties and curing properties, and to produce a flexible polyurethane foam for heating carpets by integral molding of a surface material, which is excellent in productivity and physical properties. A method is provided.

  That is, this invention is shown by following (1)-(4).

(1) In a mold in which a surface material and a heating element are set in advance, the organic polyisocyanate (A) and the polyol (B) are added in the presence of a catalyst (C), a foaming agent (D), and a foam stabilizer (E). A method for producing a flexible polyurethane foam for heating carpet that is integrally formed by reaction,
Gelling rate by falling ball type up viscometry of when-free foam, Ru der maximum value of 2.5 or less in the ratio of rise rate due to foaming height measuring method (gelation index / rise rate), organic polyisocyanate isocyanate (a), polyol (B), catalyst (C), foaming agent (D) and a foam stabilizer manufacturing method of heating carpet flexible polyurethane foams, characterized in Rukoto using a reaction mixture consisting of (E).

(2) In a mold in which a surface material and a heating element are set in advance, the organic polyisocyanate (A) and the polyol (B) are added in the presence of the catalyst (C), the foaming agent (D), and the foam stabilizer (E). A method for producing a flexible polyurethane foam for heating carpet that is integrally formed by reaction,
Catalyst (C) is 1,8-diazabicyclo -5,4,0- containing undecene, One or the time to reach the foam highest point at the time of free foaming with (rise time), the injection of the foaming mixture Organic polyisocyanate (A), polyol (B), catalyst (C), foaming agent whose relationship with the time during which the product can be taken out from the mold (demoldable time) is the relationship represented by the following formula A method for producing a flexible polyurethane foam for a heating carpet, which comprises using a reaction mixture comprising (D) and a foam stabilizer (E) .
(Equation 3)
Demoldable time (minutes)> 0.1 × (rise time (seconds) −60)
However, the rise time is 60 seconds or more.

(3) In a mold in which a surface material and a heating element are set in advance, the organic polyisocyanate (A) and the polyol (B) are added in the presence of the catalyst (C), the foaming agent (D), and the foam stabilizer (E). A method for producing a flexible polyurethane foam for heating carpet that is integrally formed by reaction,
Gelling rate by falling ball type up viscometry of when-free foam, the highest value of the ratio of the rise rate due to foaming height measuring method (gelation index / rise rate) is 2.5 or less, the catalyst (C ) Contains 1,8-diazabicyclo-5,4,0-undecene, and the product reaches the maximum in the mold (rise time) when free foaming is performed, and the product is injected into the mold from the injection of the foaming mixture. time can be taken out more relationship between (demolding allows time), Ru near relation represented by the following formula, an organic polyisocyanate (a), polyol (B), catalyst (C), foaming agent (D) And a method for producing a flexible polyurethane foam for heating carpets, comprising using a reaction mixture comprising a foam stabilizer (E) .
(Equation 4)
Demoldable time (minutes)> 0.1 × (rise time (seconds) −60)
However, the rise time is 60 seconds or more.

(4) Diphenylmethane diisocyanate-based polyisocyanate mixture (a1) in which the organic polyisocyanate (A) in the reaction mixture is composed of diphenylmethane diisocyanate (a1-1) and polymethylene polyphenyl polyisocyanate (a1-2) having 3 or more functional groups (A) is contained in an amount of 20% by mass or more, and the mass ratio of (a1-1) and (a1-2) is (a1-1) :( a1-2) = 20: 80 to 90:10,
The polyol (B) of the reaction mixture contains 50 mass% or more of the terminal ethylene oxide-capped polyoxyalkylene polyol (b1-1) having a nominal average functional group number of 2 to 4 and an average hydroxyl equivalent weight of 500 to 3,000. Heating carpet process for producing a flexible polyurethane foam according to any one of 請 Motomeko 1 you wherein 3.

The present invention will be described in further detail.
In the present invention, an organic polyisocyanate (A) and a polyol (B) are mixed with a catalyst (C), a foaming agent (D) and a foam stabilizer (E) in a mold in which a surface material and a heating element are set in advance. Is a method for producing flexible polyurethane foam for heating carpets by integral molding, which is the ratio of the gelation rate by the falling ball viscosity measurement method during free foaming to the rise rate by the foam height measurement method (gelation rate) / Rise rate) is 2.5 or less. When the maximum value of the gelation rate / rise rate exceeds 2.5, lack of meat is likely to occur. The gelation rate and rise rate are measured by the following methods.

Free foaming condition Set a polypropylene bag inside the mold with the top open, put the foamed mixture into the foamed foam, and observe and measure the foaming behavior.
Foamed mixture volume: 400 g
Foaming atmosphere temperature: 25 ° C
Mold shape: 25cm x 25cm x 25cm
Mold preheating temperature: 60 ℃
Mixing condition of foaming liquid mixture: 5,000 rpm x 7 seconds

・鉄球サイズ：質量＝０．４５ｇ、直径＝４．５mm
・鉄球の落とす位置（沈下開始位置）は、その時の発泡上面から Gelation rate measurement method The iron ball is allowed to settle freely while shifting the position at intervals of 5 seconds from the start of foaming, and after the free foaming is completed, the position at which the iron ball is stationary with respect to the final foam height is measured. Since the foam is free foaming, the final foam height varies depending on the location. Therefore, it is measured at a perpendicular line passing through the center of the iron ball.

・ Iron ball size: Mass = 0.45g, Diameter = 4.5mm
・ The position where the iron ball is dropped (settlement start position) is from the top surface of the foam.

Rise rate measurement method At the interval of 5 seconds from the start of foaming, measure the height of the top edge of the foam and the final foam height after completion of the reaction, and measure what percentage of the final foam height the foam height at each measurement. To do.

Gelation rate / rise rate calculation method The ratio of the gelation rate and the rise rate at each corresponding foaming time is calculated.

  In the present invention, a soft polyurethane foam for heating carpet, which is a so-called thin material, is manufactured using a mold, and therefore, the foamed mixed liquid needs to spread sufficiently inside the mold before foaming proceeds. For this purpose, the reactivity of the foamed mixed solution may be lowered, but if it is lowered too much, the productivity is lowered. In order to solve this problem, a temperature-sensitive catalyst may be used. Immediately after mixing the isocyanate liquid and the polyol liquid containing the temperature-sensitive catalyst, the reaction has not yet proceeded sufficiently, so the heat generation is low, and therefore the reaction activity of the temperature-sensitive catalyst is low. For this reason, there is room for the reaction mixture to flow to every corner of the mold. After the liquid reaches every corner of the mold, the reaction proceeds to a certain extent and the heat generation is sufficient. After this, the reaction activity is further improved by the temperature-sensitive catalyst, contributing to productivity improvement. become. Therefore, in the present invention, 1,8-diaza-bicyclo (5,4,0) undecene-7 having temperature sensitivity is used as the catalyst (C).

  Further, in the present invention, the catalyst (C) can be used in combination with known ones, such as dimethylethanolamine, N-trioxyethylene-N, N-dimethylamine, N, N-dimethyl-N-hexanolamine and the like. An active hydrogen group-containing tertiary amine catalyst, 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, 1-butyl-2-methylimidazole, etc. Grade amines, and these organic acid salts, stannous octoate, dibutyl tin dilaurate, organic metal compounds such as zinc naphthenate and the like.

  In order to obtain sufficient curability and filling property, the amount of the catalyst (C) used is 0.01 to 5% by mass, preferably 0.5 to 3.0% by mass, based on the polyol (B). is there. When the amount of the catalyst used is less than the lower limit, curability capable of producing a product commercially cannot be obtained, and an unpleasant odor due to unreacted substances is caused. On the other hand, if the amount is larger than the upper limit, the reaction becomes too fast, and a thin-walled, large area heating carpet cannot be obtained.

In the present invention, the time required to reach the highest foaming point during free foaming after using temperature-sensitive 1,8-diaza-bicyclo (5,4,0) undecene-7 as the catalyst (C) (rise) It is preferable that the relationship between the time) and the time during which the product can be taken out from the mold from the injection of the foamed mixture (demoldable time) is a relationship represented by the following formula.

  If the demolding time is too short, the foam will be taken out from the mold before it is fully cured, and problems such as lack of thickness, poor adhesion, and abnormal shapes are likely to occur.

The preferable raw material used for this invention is demonstrated.
Preferred organic diisocyanates (A) used in the present invention are diphenylmethane diisocyanate (a1-1, hereinafter referred to as MDI), and polymethylene polyphenyl polyisocyanate having 3 or more functional groups (a1-2, hereinafter referred to as MDI polynuclear condensation). The diphenylmethane diisocyanate-based polyisocyanate mixture (a1, hereinafter referred to as “polymeric MDI”) is contained in (A) in an amount of 20% by mass or more. When the content of polymeric MDI (a1) in the organic polyisocyanate (A) is too small, the strength of the resulting foam tends to be insufficient. In addition, when the content of MDI (a1-1) in the polymeric MDI (a1) is too small, problems such as a decrease in strength of the foam obtained and lack of wall due to poor flowability are likely to occur. When the amount is too large, problems such as poor stability (occurrence of depression or the like) of the obtained foam easily occur.

  Polymeric MDI (a1) is obtained as a mixture of MDI and an MDI-based polynuclear body by phosgenating a condensate of aniline and formalin. MDI (a1-1) can be obtained by separating the polymeric MDI by distillation or crystallization. When condensing aniline and formalin, the composition ratio of isomers in MDI and the ratio of MDI to MDI polynuclear body can be changed by controlling the feed ratio and reaction temperature. Furthermore, by mixing commercially available MDI and polymeric MDI as appropriate, the isomer composition ratio of MDI and the ratio of MDI to MDI-based polynuclear substance can be controlled. The isomers of MDI are 2,2'-diphenylmethane diisocyanate (2,2'-isomer), 2,4'-diphenylmethane diisocyanate (2,4'-isomer), and 4,4'-diphenylmethane diisocyanate. (4,4'-isomer). In the present invention, the isomer composition ratio of MDI (a1-1) in the polymeric MDI (a1) is preferably one containing 5 to 55% by mass of the 2,2′- and 2,4′-isomers. . Polymeric MDI containing MDI having an isomer composition ratio within the above range can be given stability by the foam.

  In addition, if necessary, a part can be modified with polyether polyol, the initial reactivity can be suppressed according to the shape size, the liquid flow property can be controlled, and a molded product without lacking can be obtained. it can. The prepolymer synthesis method is not particularly limited, and there are a method in which all the isocyanate raw material and polyol raw material are charged and prepolymerized, a method in which a part of the isocyanate raw material is reacted with the polyol raw material, and the remaining isocyanate raw material is mixed. Applicable.

  Other isocyanates can be used in combination for the purpose of flowability, hardness, foaming speed adjustment and the like. Specific examples include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, p-phenylene diisocyanate, m-phenylene diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, and the like. Aromatic diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, 2-methyl-1,5-pentane diisocyanate, aliphatic diisocyanates such as 3-methyl-1,5-pentane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated tri Diisocyanates such as alicyclic diisocyanates such as diisocyanate, hydrogenated xylylene diisocyanate and cyclohexyl diisocyanate , Biuret modified products of these diisocyanates, isocyanurate modified body, uretonimine modified product, a carbodiimide modified product, a urethane group-containing polyisocyanates, and the like with polyols modified.

  The content of polymeric MDI (a1) in the organic polyisocyanate (A) is at least 20% by mass or more, even if the polyisocyanate other than (a1) is used in combination or polyol is modified. In obtaining A), it means that 20% by mass or more of polymeric MDI (a1) is used.

  Since the present invention is a method for producing a flexible polyurethane foam by integral molding for heating carpets, the resulting flexible polyurethane foam is thin with respect to its bottom area. For this reason, favorable moldability is obtained by adjusting the viscosity of the organic polyisocyanate (A) at 25 ° C. to 1,000 mPa · s or less, more preferably 200 mPa · s or less. Furthermore, the isocyanate content of the organic polyisocyanate (A) is preferably 28 to 45%. When the isocyanate content is less than 28%, the raw material viscosity itself becomes too high, and the loss of flowability is likely to occur due to poor flowability and uneven foam.

  The polyol (B) to be combined with such an organic polyisocyanate is 50% by mass or more of the terminal ethylene oxide-capped polyoxyalkylene polyol (b1-1) having a nominal average functional group number of 2 to 4 and an average hydroxyl equivalent weight of 500 to 3,000. What is contained is preferable. Particularly preferably, polyoxypropylene polyol (b1) capped with terminal ethylene oxide having a nominal average functional group number of 2 to 4, an average hydroxyl equivalent of 1,000 to 3,000, and a primary hydroxyl group of 70% or more in (B). It is preferable to contain 50-90 mass%. In the present invention, “primary hydroxyl group” means a hydroxyl group bonded to a primary carbon atom.

  When the nominal average functional group number is less than 2 and the average hydroxyl equivalent exceeds 3,000, the foam strength is insufficient. When the nominal average functional group number exceeds 4, the viscosity of the polyol (B) becomes too high, the flowability of the urethane foam-forming liquid becomes poor, and the problem of lack of wall tends to occur. Moreover, when the average hydroxyl equivalent is less than 200, the flexibility and cushioning properties of the foam are impaired.

  In the present invention, it is preferable to use the polymer particle-dispersed polyol (b2) in combination for improving physical properties. The polymer particle-dispersed polyol (b2) is a polymer-dispersed polyol having a polymer solid content of 5 to 50% by mass, a nominal average functional group number of 2 to 4, and an average hydroxyl equivalent of 1,000 to 4,000. Is water, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol and other polyols, or diethanolamine, triethanolamine, tripropanolamine and other amino alcohols, ethylenediamine, 1,6-hexanediamine, Examples thereof include polyether polyols obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to amines such as triethylenetetraamine and methylenebisaniline.

  Examples of polymer particle components include aldehyde condensation resin fine particles obtained by condensing one or more compounds selected from urea compounds, melamine compounds, phenol compounds and guanidine compounds with aldehydes, acrylonitrile, styrene. , Α-methylstyrene, acrylic acid, acrylic acid ester, methacrylic acid, methacrylic acid ester, allyl alcohol, allyl ether, polymer of ethylenically unsaturated monomers such as vinyl acetate, or isocyanate and amino alcohol or amine compound The polymer etc. which are chosen from the polyurethane particle or polyurea obtained by making this react are mentioned. The content of the polymer particles in the foam is preferably 0.1 to 10% by mass. If it is less than 0.1% by mass, the strength of the foam may be insufficient. When it exceeds 10% by mass, the flexibility and cushioning properties of the foam are likely to be impaired.

  In order to improve cushioning properties, (B) has a nominal average functional group number of 2 to 4, an average hydroxyl equivalent of 1,000 to 2,500, 50% by mass or more of oxyalkylene groups are oxyethylene groups, and the rest are oxypropylene groups. It is also possible to use ethylene oxide / propylene oxide random copolymer polyether polyol (poly (oxyethylene) polyol when 100% by mass of the oxyalkylene group is an oxyethylene group) (b3). When the oxyethylene group content is too small, the foam cushioning property tends to be low. If the amount is too large, the strength of the foam tends to be low. In the present invention, (b3) is preferably contained in 3 to 10% by mass in (B). When the content is too small, the foam cushioning property tends to be low. If the amount is too large, the strength of the foam tends to be low. (B3) is a polyol such as water, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane or pentaerythritol, or an amino alcohol such as diethanolamine, triethanolamine or tripropanolamine, or ethylenediamine, It can be obtained by adding ethylene oxide or a mixture of ethylene oxide and propylene oxide using amines such as hexanediamine, triethylenetetraamine, aniline, toluylenediamine and methylenebisaniline as initiators.

  The foaming agent (D) used in the present invention is water, and more precisely, the foaming agent (D) is foamed by carbon dioxide gas generated by the reaction between an isocyanate group and water. In addition, it is also possible to use a gas loading device to mix and dissolve a gas such as air, nitrogen, carbon dioxide or the like in the stock solution, or to mix and form carbon dioxide in a liquid state to evaporate and foam during foaming. Non-halogen low-boiling compounds include propane, normal butane, isobutane, normal pentane, isopentane, normal hexane, cyclopentane, furan, dimethyl ether, diethyl ether, acetone, methyl ethyl ketone, methyl formate, dimethyl oxalate, ethyl acetate, etc. It can also be used additionally.

  The foam stabilizer (E) used in the present invention is an organosilicon surfactant known in the art, such as L-520, L-540, L-5309, L-5366, manufactured by Nippon Unicar Co., Ltd. SZ-1306, Toray Dow Corning SH-193, SRX-274C, Goldschmidt B-4113, and the like.

  In addition, the present invention can be used by further adding an antioxidant, an ultraviolet absorber, a colorant, various fillers, an internal mold release agent, an antifungal agent, an antibacterial agent and other processing aids as necessary. These auxiliaries are usually used by adding them to polyols, but processing auxiliaries having no active hydrogen group capable of reacting with isocyanate can be mixed in advance with the isocyanate component. In addition, the phosphoric acid ester compound and the halogenated phosphoric acid ester compound generally used as a viscosity reducing agent / flame retardant are not preferable for the present invention because they cause odor when the heating carpet is used.

  The flexible polyurethane foam from the present invention usually comprises a polyisocyanate liquid composed of an organic polyisocyanate (A), a polyol (B), a catalyst (C), a foaming agent (D), a foam stabilizer (E), if necessary. It is obtained by using two components of a polyol liquid in which additives, processing aids and the like are mixed in advance, and mixing and foaming the two liquids. For mixing, a mixing head having a known low-pressure mechanical stirring device, an injection head having a high-pressure collision mixing mechanism, or a spray head can be used. In addition, when coloring a foam, it is preferable to use the apparatus which can supply a coloring agent directly to a mixing head from a color change surface or an economical surface.

  In the present invention, the isocyanate index (isocyanate group (mol) / active hydrogen group (mol) × 100) is preferably 60 to 150, more preferably 70 to 120.

The size of the heating carpet obtained by the present invention is half tatami mat to 4.5 tatami mat, and the effect is further exhibited when used for 2 to 3 tatami mat size. The flexible polyurethane foam preferably has a thickness of 2 to 30 mm, a density of 0.05 to 0.2 g / cm ³ , and a hardness of 20 to 90 when measured with a CSC2 hardness meter manufactured by Kobunshi Keiki. Regarding the measurement of hardness, the measurement temperature is 25 ° C., the sample thickness is 5 to 50 mm, and the sample thickness of less than 5 mm is measured by overlapping the same foam.

  The mold for integral molding is not particularly limited as long as the surface material, the back surface material, and the heating element can be set in advance and the product can be taken out, but usually the upper and lower separate types are used. A surface material, a back material, and a heating element are set in advance in each of the upper mold and the lower mold, and the liquid is injected by opening the mold. As the liquid injection method, a method using an injection head and a method using a spray head can be applied. When the product area is large, it is preferable to traverse the injection head or spray head so that the liquid spreads in the mold as much as possible. Moreover, it is preferable that the metal mold | die, surface material, and back surface material are managed within the range of 15-70 degreeC for stable manufacture and cure property promotion. The mold clamping after the liquid injection should be as quick as possible, preferably within 1 minute after the injection at the latest. Although the demolding time depends on the mold temperature, it is preferably within 6 minutes from the viewpoint of production efficiency.

  The present invention will be described more specifically with reference to the following examples, but the present invention is not limited thereto. “Parts” and “%” indicate “parts by mass” and “% by mass” unless otherwise specified. The isocyanate used: MDI-1, PMDI-1, TDI-1, polyol: B-1 to B-6, catalyst: C-1 to C-4, and foam stabilizer: E-1 are shown below.

MDI-1: MDI
2,2'- and 2,4'-isomer content in MDI = 20%
PMDI-1: Polymeric MDI
MDI: MDI polynuclear body = 40: 60
2,2'- and 2,4'-isomer content in MDI = 1%
Isocyanate content = 30.7%
TDI-1: Tolylene diisocyanate (TDI)
2,4-isomer content in TDI = 80%
2,6-isomer content in TDI = 20%
B-1: Polyoxypropylene glycol
Nominal average functional group = 2
Number average molecular weight = 3,000
B-2: 14% ethylene oxide capped polyoxypropylene polyol
Nominal average functional group = 3
Number average molecular weight = 5,100
B-3: 17% ethylene oxide capped polyoxypropylene polyol
Nominal average functional group = 3
Number average molecular weight = 6,000
B-4: ethylene oxide / propylene oxide = 1/2 (mass ratio)
Random copolymer polyether polyol
Nominal average functional group = 3
Average hydroxyl equivalent = 3,500
B-5: Polyoxyethylene polyol
Nominal average functional group = 3
Number average molecular weight = 1,000
B-6: Acrylic polymer-dispersed polyol containing 22% polymer particles
Base polyol:
Polyoxypropylene polyol with 17% ethylene oxide cap
Nominal average functional group = 3
Number average molecular weight = 6,000
Polymer composition:
Acrylonitrile / styrene = 45/55 (mass ratio)
C-1: a solution of triethylenediamine in dipropylene glycol (DPG),
(Product name TEDA-L33, manufactured by Tosoh Corporation)
C-2: Tertiary amine
(Product name TOYOCAT-HX70, manufactured by Tosoh Corporation)
C-3: tertiary amine carboxylate
(Product name TOYOCAT-NCE, manufactured by Tosoh Corporation)
C-4: 1,8-diaza-bicyclo (5,4,0) undecene-7
(Product name: Dabco DBU, manufactured by Air Products)
E-1: Silicone foam stabilizer
(Product name L-5309, manufactured by Nihon Unicar)

<Formulation Examples 1-3>
Preparation of polyisocyanate A-1 to 3 Each raw material polyisocyanate was charged in a reactor equipped with a stirrer, a cooling tube, and a thermometer with the composition shown in Table 1, and stirred and mixed at 80 ° C. for 1 hour, and then cooled to room temperature. Thus, polyisocyanate A-1 to A-3 were prepared.

<Synthesis example>
Manufacture of polyisocyanate A-4 A reactor equipped with a stirrer, a condenser, and a thermometer was charged with 463 parts of MDI-1, 379 parts of PMDI-1, and 158 parts of polyol B-1 at 80 ° C for 4 hours. After reacting, it was cooled to room temperature. The obtained polyisocyanate A-4 had an NCO content of 26.7% and a viscosity at 25 ° C. of 110 mPa · s.

<Formulation examples 4 to 10>
Manufacture of preparation of polyol premix Charge each polyol, catalyst, etc. with the composition shown in Table 2 into a reactor equipped with a stirrer, condenser, and thermometer, stir and mix at 80 ° C for 1 hour, then cool to room temperature. Thus, polyol premixes P-1 to 7 were prepared.

Examples 1-5, Comparative Examples 1-2
<Free foaming>
A polypropylene bag was set inside the open mold, and the foamed mixed solution shown in Tables 3 to 9 was placed in the mold and foamed. The foaming behavior was observed and measured. Tables 3 to 9 show the foaming behavior measurement results and rise time measurement results, and Table 10 shows the free-form physical properties. Moreover, the graph with respect to the foaming time of the gelatinization rate / rise rate especially in Example 2 and Comparative Example 1 is shown in FIG.
Free foaming condition Foaming mixture amount: 400g
Foaming atmosphere temperature: 25 ° C
Mold shape: 25cm x 25cm x 25cm
Mold preheating temperature: 60 ℃
Mixing conditions of foaming liquid mixture: 5,000 rpm x 7 seconds Gelation rate measurement method, rise rate measurement method, gelation rate / rise rate calculation method As described above.

<Molding-1>
Using a high-pressure foam molding machine equipped with a CANNON L-shaped head, 2500 g of the reaction mixture having the composition shown in Table 2 was linearly traversed into the mold center. The mold was an aluminum mold with an inner dimension of 2,000 × 2,000 mm having gas vent holes at the four corners, and a mold whose thickness was adjustable was adjusted to 60 ° C. and used. For evaluation of moldability, in a mold adjusted to a thickness of 10 mm, a PE film treated with corona discharge having a thickness of 0.05 mm is set in advance in the lower mold, and the upper mold is also 2 mm thick and has a weight of 200 g / m ² . A surface material in which a tube heater with a diameter of 2.5 mm is bonded to a cloth coated with a 0.05 mm thick corona discharge-treated PE film on the inner surface of the pile ground is set in advance, and the mixed reaction mixture is placed in the mold. The upper mold was clamped 30 seconds after the start of injection, and the mold was removed after 5 minutes to obtain an integrally molded polyurethane foam sheet.
Moreover, the flexible foam sheet | seat was similarly obtained so that it might become a predetermined density in the same metal mold thickness for evaluation of a physical property. The physical properties were measured by leaving the foam sheet at 25 ° C. × 60% RH for 24 hours and then cutting it into a predetermined size.

Physical property evaluation conditions Measured according to JIS K6400.
Hardness measurement Measured with a CSC2 hardness meter manufactured by Kobunshi Keiki.

  From Tables 3-10 and FIG. 1, the flexible polyurethane foam obtained by this invention was a favorable thing, without producing a lack of thickness. On the other hand, in the comparative example, since the gelation ratio / rise ratio exceeded 2.5, the reaction was too fast, resulting in lack of thickness.

Examples 6-8, Comparative Examples 3-5
<Molding-2>
Using a high-pressure foam molding machine equipped with a CANNON L-shaped head, 2,500 g of the reaction mixture having the composition shown in Table 11 was linearly traversed into the mold center. The mold was an aluminum mold with an inner dimension of 2,000 × 2,000 mm having gas vent holes at the four corners, and a mold whose thickness was adjustable was adjusted to 60 ° C. and used. For evaluation of moldability, in a mold adjusted to a thickness of 10 mm, a PE film treated with corona discharge having a thickness of 0.05 mm is set in advance in the lower mold, and the upper mold is also 2 mm thick and has a weight of 200 g / m ² . A surface material in which a tube heater with a diameter of 2.5 mm is bonded to a cloth coated with a 0.05 mm thick corona discharge-treated PE film on the inner surface of the pile ground is set in advance, and the mixed reaction mixture is placed in the mold. After 30 seconds from the start of injection, the upper mold was tightened, and after the demolding time shown in Table 11, the mold was removed to obtain an integrally molded polyurethane foam sheet.
In addition, the demolding standard time in Table 11 is the time calculated by the following formula.

  From Table 11, in the system using 1,8-diaza-bicyclo (5,4,0) undecene-7 as the catalyst, when the demolding time was longer than the demolding standard time, the curing property was good. When cured, the curing property was poor. When the demolding time is shorter than the demolding guide time, it indicates that the molding is not sufficiently cured.

It is a graph with respect to the ratio of the gelation rate / rise rate of Example 2 and Comparative Example 1 to foaming time.

Solid line: gelation rate / rise rate curve of Example 2

Dashed line: Gelation rate / rise rate curve of Comparative Example 1

Claims (4)

Surface material, in a mold which was previously set a heating element, an organic polyisocyanate (A) and the polyol (B), catalyst (C), is reacted in the presence of a blowing agent (D) and foam stabilizer (E) a method of manufacturing a heating carpet for flexible polyurethane foam molded integrally Te,
Gelling rate by falling ball type up viscometry of when-free foam, Ru der maximum value of 2.5 or less in the ratio of rise rate due to foaming height measuring method (gelation index / rise rate), organic polyisocyanate isocyanate (a), polyol (B), catalyst (C), foaming agent (D) and a foam stabilizer manufacturing method of heating carpet flexible polyurethane foams, characterized in Rukoto using a reaction mixture consisting of (E). Surface material, in a mold which was previously set a heating element, an organic polyisocyanate (A) and the polyol (B), catalyst (C), is reacted in the presence of a blowing agent (D) and foam stabilizer (E) a method of manufacturing a heating carpet for flexible polyurethane foam molded integrally Te,
Catalyst (C) is 1,8-diazabicyclo -5,4,0- containing undecene, One or the time to reach the foam highest point at the time of free foaming with (rise time), the injection of the foaming mixture Organic polyisocyanate (A), polyol (B), catalyst (C), foaming agent whose relationship with the time during which the product can be taken out from the mold (demoldable time) is the relationship represented by the following formula A method for producing a flexible polyurethane foam for a heating carpet, which comprises using a reaction mixture comprising (D) and a foam stabilizer (E) .
(Equation 1)
Demoldable time (minutes)> 0.1 × (rise time (seconds) −60)
However, the rise time is 60 seconds or more. Surface material, in a mold which was previously set a heating element, an organic polyisocyanate (A) and the polyol (B), catalyst (C), is reacted in the presence of a blowing agent (D) and foam stabilizer (E) a method of manufacturing a heating carpet for flexible polyurethane foam molded integrally Te,
Gelling rate by falling ball type up viscometry of when-free foam, the highest value of the ratio of the rise rate due to foaming height measuring method (gelation index / rise rate) is 2.5 or less, the catalyst (C ) Contains 1,8-diazabicyclo-5,4,0-undecene, and the product reaches the maximum in the mold (rise time) when free foaming is performed, and the product is injected into the mold from the injection of the foaming mixture. time can be taken out more relationship between (demolding allows time), Ru near relation represented by the following formula, an organic polyisocyanate (a), polyol (B), catalyst (C), foaming agent (D) And a method for producing a flexible polyurethane foam for heating carpets, comprising using a reaction mixture comprising a foam stabilizer (E) .
(Equation 2)
Demoldable time (minutes)> 0.1 × (rise time (seconds) −60)
However, the rise time is 60 seconds or more. The organic polyisocyanate (A) in the reaction mixture is a diphenylmethane diisocyanate polyisocyanate mixture (a1) composed of diphenylmethane diisocyanate (a1-1) and polymethylene polyphenyl polyisocyanate (a1-2) having 3 or more functional groups (A1). ) Is contained in an amount of 20% by mass or more, and the mass ratio of (a1-1) and (a1-2) is (a1-1) :( a1-2) = 20: 80 to 90:10. And
The polyol (B) of the reaction mixture contains 50 mass% or more of the terminal ethylene oxide-capped polyoxyalkylene polyol (b1-1) having a nominal average functional group number of 2 to 4 and an average hydroxyl equivalent weight of 500 to 3,000. Heating carpet process for producing a flexible polyurethane foam according to any one of 請 Motomeko 1 you wherein 3.

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