JP2002322236A - Method for producing soft polyurethane slab foam - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide soft polyurethane slab foam having a soft surface touch, a supporting property, endurance and a flame retardant property. SOLUTION: This soft polyurethane slab foam is characterized by using a prepolymer having 23-33 mass % NCO content and obtained by reacting an MDI containing 20-50 mass % 2,4'-isomer with a polymethylenepolyphenylpolyisocyanate having >=3 benzene rings as a urethane- modified polyisocyanate and a polyalkylene polyol having 200-2,500 hydroxyl equivalent, and as a polyol, a polyoxyalkylene polyol consisting of a terminal ethylene oxide-capped polyoxypropylene polyol having 2-4 nominal number of functional groups and 1,000-2,500 mean hydroxyl equivalent, and a polyoxyalkylene polyol in which oxyethylene in the oxyalkylene is >=50 mass %, having 2-6 number of functional groups and 200-2,000 mean hydroxyl equivalent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a flexible polyurethane slab foam, and more particularly, to a supportability, durability, flame retardancy, production efficiency, excellent working environment, low viscosity and low temperature. The present invention relates to a method for producing a flexible polyurethane slab foam using a liquid storable isocyanate.

[0002]

2. Description of the Related Art Soft polyurethane slab foam is cut into a suitable size, and is used for a wide range of applications such as cushioning materials for furniture and automobile seats, mattresses for bedding, pillows, industrial sealing materials, and soundproofing materials. In recent years, with the aging, the need for good supportability in furniture and mattress applications, and moreover, for foams with high flame retardancy has been increasing. At the production site, a highly reactive and highly curable raw material system with high production efficiency is desired.

Although a technique using toluene diisocyanate as a polyisocyanate component as a flexible polyurethane slab foam is already widely known, the freezing point of toluene diisocyanate is as high as about 17 ° C. under normal pressure, and the solidification temperature in winter is high. , Temperature control was required. Recently, a slab foam using diphenylmethane diisocyanate having a low vapor pressure as a polyisocyanate component has been proposed in view of the effect of isocyanate on the worker's health at the production site and the improvement of reactivity, but 4,4'-diphenylmethane diisocyanate has been proposed. Has a freezing point of about 38 at normal pressure
The temperature is higher than that of toluene diisocyanate, and processing such as a prepolymer method is required. As a result, the viscosity becomes extremely high, so that there have been problems such as deterioration in workability and limitations due to production equipment conditions. It has high productivity and meets various market needs such as supportability, durability, flame retardancy,
Further, a technique for producing a flexible polyurethane slab foam from a raw material which can be handled in a liquid state even in winter and is not restricted by the conditions of production equipment has been hitherto unknown.

[0004]

SUMMARY OF THE INVENTION The present invention relates to an isocyanate component comprising a polyol-modified polyisocyanate starting from a specific diphenylmethane diisocyanate having a low viscosity and being storable in a liquid state at a low temperature, a specific polyether polyol, a blowing agent, Using a catalyst, a foam stabilizer, and additives as necessary, a method for producing a soft polyurethane slab foam having a soft surface feel, supportability, durability, and flame retardancy is provided. 15-80 kg / m ³ , hardness 30-250 N in ILD
/ 314 cm ² of a flexible polyurethane slab foam.

[0005]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that by using a specific urethane foam composition, the moldability, supportability, durability and flame retardancy are excellent, and low viscosity It has been found that a flexible polyurethane slab foam can be obtained from isocyanates which can be stored in a liquid state at a low temperature. That is, the present invention is as follows.

(1) A mixture of an organic polyisocyanate, a polyol, a catalyst, water as a foaming agent, a foam stabilizer, and other auxiliaries is poured onto a box or a conveyor and foamed by reaction to produce a flexible polyurethane slab foam and a method for producing the same. Wherein (a) 2,4'-
60 to 98 parts by mass of diphenylmethane diisocyanate containing 20 to 50% by mass of an isomer and 2 to 4 nominal functional groups;
A prepolymer having an isocyanate content of 23 to 33% by mass, comprising 2 to 40 parts by mass of a polyoxyalkylene polyol having an average hydroxyl equivalent of 200 to 2,500,
The average number of functional groups of the prepolymer is 2.00 to 2.25.
(B) urethane-modified polyisocyanate
Polyoxypropylene polyol (a) having a terminal ethylene oxide cap having a nominal number of functional groups of 2 to 4 and an average hydroxyl equivalent of 1,000 to 2,500 and oxyethylene in oxyalkylene is 50% by mass or more. It consists of a polyoxyalkylene polyol (b) having a nominal number of functional groups of 2 to 6 and an average hydroxyl equivalent of 200 to 2,000, and its mass ratio is (B1) = 1.
(B2) contains two components consisting of 0.5 to 25, and (c) all isocyanate groups in the organic polyisocyanate (A) and all isocyanate-reactive groups in the isocyanate-reactive compound containing water. The equivalent ratio of 0.5 to
1.5. A method for producing a flexible polyurethane slab foam, which is 1.5.

(2) In a flexible polyurethane slab foam and a method for producing the same, a mixed solution of an organic polyisocyanate, a polyol, a catalyst, water as a foaming agent, a foam stabilizer, and other auxiliaries is poured onto a box or a conveyor and foamed by reaction. (A) 60 to 98% by weight of diphenylmethane diisocyanate containing 20 to 50% by weight of 2,4'-isomer as an organic polyisocyanate, and polymethylene polyphenyl polyisocyanate comprising a polynuclear body having three or more benzene rings is used. A prepolymer having an isocyanate content of 23 to 33% by mass, comprising 20 parts by mass and 1 to 40 parts by mass of a polyoxyalkylene polyol having a nominal number of functional groups of 2 to 4 and an average hydroxyl equivalent of 200 to 2,500. Urethane-modified polyester having an average number of functional groups of 2.00 to 2.25 (Ii) Polyoxypropylene polyol (a) having a terminal ethylene oxide cap having a nominal number of functional groups of 2 to 4 and an average hydroxyl equivalent of 1,000 to 2,500.
And oxyethylene in the oxyalkylene is 50% by mass or more of 2 to 6 nominal functional groups and an average hydroxyl equivalent of 2
A polyoxyalkylene polyol (b) having a mass ratio of (B1) = 100 to (B1) = 100, and (B2) containing 0.5 to 25;
(C) a soft material characterized in that the equivalent ratio of all isocyanate groups in the organic polyisocyanate (A) to all isocyanate-reactive groups in the water-containing isocyanate-reactive compound is 0.5 to 1.5. Manufacturing method of polyurethane slab foam.

(3) The method for producing a flexible polyurethane slab foam according to (1) or (2), wherein the viscosity of the organic polyisocyanate (A) at 25 ° C. is 400 mPa · s or less.

(4) Organic polyisocyanate (A)
The method for producing a flexible polyurethane slab foam according to any one of (1) to (3), wherein the foam is liquid at 15 ° C. for a period of one day or more.

(5) The polyoxypropylene polyol (B1) is a polyoxypropylene polyol having a nominal ethylene number of 2 to 4 and an average hydroxyl equivalent of 1,000 to 2,500 and having an ethylene oxide cap at the terminal, and a primary hydroxyl group at the terminal. The method for producing a flexible polyurethane slab foam according to any one of (1) to (4), wherein the conversion is 30 mol% or more.

(6) The density of the obtained foam is 15 to
80kg / m ^3, ILD is 30~250N / 314cm
^{2. The} method for producing a flexible polyurethane slab foam according to any one of (1) to (5), wherein the elongation percentage is 100% or more.

This will be described in more detail. The organic polyisocyanate (A) used in the present invention comprises 60 to 98 parts by mass of diphenylmethane diisocyanate containing 20 to 50% by mass of 2,4'-diisocyanate isomer and a nominal number of functional groups of 2
4, a prepolymer having an isocyanate group (hereinafter, sometimes abbreviated as NCO) content of 23 to 33% by mass obtained by reacting 2 to 40 parts by mass of a polyoxyalkylene polyol having an average hydroxyl equivalent of 200 to 2,500. The average number of functional groups of the prepolymer is 2.00 to
It is a urethane-modified polyisocyanate of 2.25.

Further, the organic polyisocyanate (A) used in the present invention comprises 60 to 98 parts by mass of diphenylmethane diisocyanate containing 20 to 50% by mass of 2,4'-diisocyanate isomer, and a polynuclear having three or more benzene rings. NC obtained by reacting 1 to 20 parts by mass of a polymethylene polyphenyl polyisocyanate composed of a product, 1 to 40 parts by mass of a polyoxyalkylene polyol having a nominal number of functional groups of 2 to 4 and an average hydroxyl equivalent of 200 to 2,500
It is a prepolymer having an O group content of 23 to 33% by mass, and may be a urethane-modified polyisocyanate having an average number of functional groups of 2.00 to 2.25.

Further, the viscosity of the organic polyisocyanate at 25 ° C. is preferably 400 mPa · s or less, more preferably 200 mPa · s or less.

Here, the polymethylene polyphenylene polyisocyanate will be described. Polymethylene polyphenylene polyisocyanate is a polyisocyanate obtained by phosgenating a polyamine obtained by a condensation reaction of aniline and formaldehyde, and has two benzene rings, diphenylmethane diisocyanate (also referred to as a binuclear body) and a benzene ring. It is obtained as a mixture of three or more homologs of polyisocyanates (expressed as polynuclears in the present invention). The polymethylene polyphenylene polyisocyanate comprising a polynuclear body having three or more benzene rings in the present invention is a compound excluding diphenylmethane methane diisocyanate obtained by phosgenation of a diamine obtained from 2 mol of aniline and 1 mol of formaldehyde.

[0016] Polymeric MDI shown in the following embodiments
Is a polymethylene polyphenylene polyisocyanate composed of diphenylmethane diisocyanate and a polynuclear body having three or more benzene rings, and is, for example, Millionate (registered trademark) MR-10 manufactured by Nippon Polyurethane Industry.
0, Millionate MR-200 and the like.

When the 2,4'-isomer ratio of diphenylmethane diisocyanate contained in the organic polyisocyanate (A) is less than 20% by mass, the stability of the foam is impaired and the storage stability at low temperatures is impaired. 5
If it exceeds 0% by mass, the air permeability of the foam decreases,
The curing property is remarkably reduced.

When the content of the diphenylmethane diisocyanate component in the organic polyisocyanate (A) is less than 60% by mass, the flexibility of the foam is reduced, and the mechanical strength such as elongation properties is particularly remarkably deteriorated. On the other hand, if it exceeds 98% by mass, 2,2 in diphenylmethane diisocyanate
Even when the 4'-isomer ratio is 50% by mass, the storage stability at low temperatures is deteriorated.

The NCO content of the organic polyisocyanate (A) is 23 to 33% by mass, particularly preferably 25 to 3%.
0% by mass. NC of organic polyisocyanate (A)
When the O content exceeds 33% by mass, the storage stability at 15 ° C. is deteriorated, and it is difficult to handle in a liquid state. On the other hand, when the NCO content is less than 23% by mass, the viscosity of the raw material itself becomes too high, and special production equipment is required. In addition, poor flowability tends to cause underfill and uneven foam.

The polyoxyalkylene polyol used in the prepolymer synthesis has a nominal number of functional groups of 2 to 2.
4. polyols such as water, propylene glycol, dipropylene glycol, diethylene glycol, glycerin, trimethylolpropane, and pentaerythritol, having an average hydroxyl equivalent of 200 to 2,500,
Or diethanolamine, triethanolamine,
Examples include amino alcohols such as tripropanolamine or amines such as ethylenediamine, 1,6-hexanediamine and methylenebisaniline, and block or random ring-opening copolymers of alkylene oxides such as ethylene oxide and propylene oxide.

For the purpose of improving the heat sealing property and the adhesiveness in post-processing, other polyols can be used for modifying the prepolymer within a range not exceeding the total amount of the modifying polyoxyalkylene polyol. Specific examples thereof include glutaric acid, adipic acid, sebacic acid, azelaic acid, phthalic anhydride, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, dicarboxylic acids such as dimer acid, and ethylene glycol, 1,2-propylene. Glycol, diethylene glycol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 3-methyl-1,
5-pentanediol, 2-ethyl-2-butyl-1,
Cyclic lactones such as diols of 3-propanediol and 1,9-nonanediol, polyester polyols obtained by polycondensation with triols such as glycerin and trimethylolpropane, and ε-caprolactone and δ-valerolactone are used as ethylene glycol. And polyester glycol obtained by ring-opening polymerization using diethylene glycol, neopentyl glycol, glycerin, trimethylolpropane and the like as initiators, and polytetramethylene glycol obtained by cationic polymerization of tetrahydrofuran. The hydroxyl equivalent of these polyols is preferably from 200 to 2,000.

The method of synthesizing the prepolymer is not particularly limited, and is a method in which the entire amount of the isocyanate raw material and the polyol raw material are charged and prepolymerized. Methods and the like can be applied. Also,
The present organic polyisocyanate can be further divided into two components depending on the number of raw material components applicable to the foaming machine used. In this case, the organic polyisocyanate is preferably a two-component component mainly composed of a prepolymer composed of diphenylmethane diisocyanate and a polyol, and a component mainly composed of polymethylene polyphenyl polyisocyanate containing diphenylmethane diisocyanate.
Depending on the mixing ratio of the mixing device, the prepolymer main component may partially contain the polymethylene polyphenylisocyanate component, or the polymethylene polyphenylene polyisocyanate component may be partially prepolymerized. By dividing into two components in this way, the range of adjusting the hardness and the density can be further expanded.

It should be noted that other isocyanates may be used in combination for the purpose of adjusting flowability, hardness, foaming speed and the like. Specific examples include 2,4-toluene diisocyanate,
2,6-toluene diisocyanate, o-xylylene diisocyanate, m-xylylene diisocyanate, p
-Aromatic diisocyanate such as xylylene diisocyanate, hexamethylene diisocyanate, 2-methyl-
1,5-pentanediisocyanate, 3-methyl-1,
Aliphatic diisocyanates such as 5-pentane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated toluene diisocyanate, hydrogenated xylylene diisocyanate, diisocyanates such as alicyclic diisocyanates such as cyclohexyl diisocyanate, and biuret modified products of these diisocyanates, isocyanates Nurate-modified, uretonimine-modified, carbodiimide-modified, and polyol-modified products.

The polyol (B) of the present invention has a nominal number of functional groups of 2 to 4 and an average hydroxyl equivalent of 1,000 to 2,500.
A polyoxypropylene polyol having a terminal ethylene oxide cap of 0, more preferably a polyoxypropylene polyol (B1) having a terminal hydroxyl group primary degree of not less than 30 mol% and oxyethylene in the oxyalkylene being 50% by mass. It consists of the above polyoxyalkylene polyol (B2) having 2 to 6 functional groups and an average hydroxyl equivalent of 200 to 2,000, and the mass ratio of (B2) is 0.5 to 25 with respect to 100 parts by mass of (B1). Parts by weight. If the average hydroxyl equivalent of the polyol (B) is less than 1,000, the flexibility of the foam cannot be obtained. On the other hand, when it exceeds 2,500, synthesis of the foam cannot be obtained, and sufficient mechanical strength cannot be obtained.

These polyoxyalkylene polyols include polyols such as water, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, pentaerythritol and sorbitol, or amino alcohols such as diethanolamine, triethanolamine and tripropanolamine. Alternatively, it can be obtained by adding propylene oxide or ethylene oxide to amines such as ethylenediamine, 1,6-hexanediamine, triethylenetetraamine, aniline, toluylenediamine, and methylenebisaniline.

In the present invention, a polymer polyol having a solid content of 15 to 50% by mass and having 2 to 4 functional groups and an average hydroxyl equivalent of 1,000 to 3,000 is further used in combination for the purpose of improving flame retardancy and adjusting hardness. be able to. As the base polyol, water, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, polyols such as pentaerythritol, or diethanolamine, triethanolamine, amino alcohols such as tripropanolamine, or ethylenediamine, 1, Polyether polyols obtained by adding alkylene oxides such as ethylene oxide and propylene oxide to amines such as 6-hexanediamine, triethylenetetraamine and methylenebisaniline can be used. As the polymer particle component, acrylonitrile, styrene, a polymer of an ethylenically unsaturated monomer such as methyl methacrylate and / or urea,
An aminoplast resin selected from melamine and phenol can be used. Specific examples of polymer polyols using aminoplast resins include trade names M-950, US-301, UH-201, and UC-8 manufactured by Asahi Glass.
01. Polyurethane particles or polyurea particle-dispersed polyether polyol obtained by reacting an isocyanate with an amino alcohol or an amine compound in a polyether polyol can also be used. Particularly preferred polymer components are urea, melamine,
It is an aminoplast resin selected from phenol.

As the catalyst used in the present invention, various urethanization catalysts and trimerization catalysts known in the art can be used. Representative examples include triethylamine, tripropylamine, tributylamine, N-methylmorpholine, N-ethylmorpholine, dimethylbenzylamine,
N, N, N ', N'-tetramethylhexamethylenediamine, N, N, N', N ', N "-pentamethyldiethylenetriamine, triethylenediamine, bis- (2-
Tertiary amines such as dimethylaminoethyl) ether, 1,8-diaza-bicyclo (5,4,0) undecene-7,
Dimethylethanolamine, N-trioxyethylene-
Reactive tertiary amines such as N, N-dimethylamine, N, N-dimethyl-N-hexanolamine or organic acid salts thereof, 1-methimidazole, 2-methylimidazole, 1,2-dimethylimidazole, 2, Imidazole compounds such as 4-dimethylimidazole and 1-butyl-2-methylimidazole; organic metal compounds such as stannas octoate, dibutyltin dilaurate and zinc naphthenate; 2,4,6-tris (dimethylaminomethyl) phenol; 2,4,6-tris (dialkylaminoalkyl) hexahydro-S-triazine, potassium acetate, 2
-A trimerization catalyst such as potassium ethylhexanoate. It is preferable to use at least an imidazole-based compound and an ether group-containing tertiary amine compound as the catalyst from the viewpoint of a mild reaction and a high curing property, and a particularly preferable catalyst is 1,2-dimethylimidazole and bis-.
It is a combination with (2-dimethylaminoethyl) ether.

The foaming agent used in the present invention is foamed by carbon dioxide gas generated by the reaction between isocyanate groups and water. For the purpose of lowering the density, carbon dioxide is mixed in a liquid state and foamed during foaming. The methods can be used together. The amount of water is preferably 2 to 20 parts by mass based on 100 parts by mass of the organic polyisocyanate. When liquefied carbon dioxide is used in combination, the amount is preferably 0.5 to 6 parts by mass with respect to 100 parts by mass of the organic polyisocyanate.

The foam stabilizer used in the present invention is an organic silicon-based surfactant known in the art, for example, L-520, L-540, L-5309, L-536 manufactured by Nippon Unicar.
6, SZ-1306, SH- made by Dow Corning Toray
190, SH-192, SH-193, SH-194,
SRX-274C, SF-2962, SF-2964,
Gold Schmidt B-4113, B-8680,
DC-2583, DC-504 manufactured by Air Products
3, DC-5169 and the like. These foam stabilizers are preferably used in an amount of 0.1 to 3 parts by mass based on 100 parts by mass of the organic polyisocyanate.

In the present invention, diethanolamine or triethanolamine can be added for the purpose of stabilizing the cell. A preferable addition amount is 0.5 to 5 parts by mass with respect to 100 parts by mass of the polyol component.

The present invention is further represented by trichloroethyl phosphate, trichloropropyl phosphate, phosphorus-halogen type liquid flame retardants represented by these condensation types, solid flame retardants represented by melamine powder, and Ketjen black, if necessary. Plasticizers such as conductive carbon and dioctyl phthalate, antioxidants, ultraviolet absorbers, coloring agents, internal mold release agents, and other auxiliaries can be used.
These auxiliaries are usually used by adding them to a polyol. However, auxiliaries having no active hydrogen capable of reacting with isocyanate can also be mixed in advance with an organic isocyanate.

The equivalent ratio (NCO / NC) of the total isocyanate groups in the isocyanate-reactive compound containing water to all the isocyanate groups in the organic polyisocyanate of the present invention.
The O-reactive group is 0.5 to 1.5 (isocyanate index = 50 to 150), and particularly preferably 0.7 to 1.2 (isocyanate index = 70 to 150).
120).

As the production apparatus in the present invention, a multi-component type foaming machine having a rotor rotating type or high pressure impingement type mixing head known in the art for mixing raw materials is used. A slab foam of any size can be obtained by foaming in a box shape or continuously on a belt conveyor.

[0034]

Next, the present invention will be specifically described based on examples and comparative examples, but the present invention is not limited to these examples unless it exceeds the gist. In addition,
Unless otherwise specified, “parts” and “%” in the text are based on mass. (Raw materials used) (1) Isocyanate MDI-1: Diphenylmethane diisocyanate containing 10% of 2,4'-diphenylmethane diisocyanate MDI-2: Diphenylmethane diisocyanate containing 30% of 2,4'-diphenylmethane diisocyanate MDI-3: 2 Diphenylmethane diisocyanate containing 50% of 4'-diphenylmethane diisocyanate Polymeric MDI-1: 40% binuclear 2,4-MDI in binuclear 10% Viscosity 200 mPa · s NCO = 31.3% Average number of functional groups = 2.70 Polymeric MDI-2: 35% binuclear 2,4-MDI in binuclear 50% Viscosity 250 mPa · s NCO = 30.0% Average number of functional groups = 2.75 TDI-80: (2 , 4-Toluene diisocyanate / 2,6 Toruenjiiso cyanate = 80/20 mixture)

(2) Polyol Polyol A: a polyoxypropylene polyol having a nominal number of functional groups of 3, and an average hydroxyl equivalent of 1,000. Polyol B: containing an oxyethylene terminal (7%) having a nominal number of functional groups of 3, and an average hydroxyl equivalent of 1,000. Polyoxypropylene polyol (primary degree of terminal hydroxyl group: 50 mol%) Polyol C: Nominal functional group 3, average hydroxyl equivalent 1,700, polyoxypropylene polyol containing oxyethylene terminal (15%) (terminal hydroxyl group) Polyol D: Polyoxyethylene / propylene random copolymer polyol containing nominal number of functional groups 3, average hydroxyl equivalent 1,250, oxyethylene 80% Polyol E: Nominal number of functional groups 3, average Polyoxy with a hydroxyl equivalent of 500 Ethylene Polyol Polyol F: nominal functionality 6, polyoxyethylene polyol polyol having an average hydroxyl equivalent weight of 200 G: nominal functionality 2, an average polyoxyethylene polyol hydroxyl equivalent weight 300

(3) Catalyst TOYOCAT DP-70: DPG solution of amine catalyst 1,2-dimethylimidazole TEDA L33: Toda TE33 Lamine: DPG solution of triethylenediamine TOYO TOYOCAT ET: Amine catalyst Bis (2-dimethylaminoethyl) Ether Tosoh Dabco T-9: Metal Catalyst Stanas Octoate Air Products

(4) Additives Diethanolamine SH-210: silicone foam stabilizer Dabco DC194 made by Witco: silicone foam stabilizer Air Products SRX-280A: silicone foam stabilizer Dow Corning Toray

(Synthesis of Polyisocyanate) After a reactor equipped with a stirrer, a cooling pipe, a nitrogen introducing pipe, and a thermometer was purged with nitrogen, predetermined amounts of isocyanates A and C were charged.
Was heated. Next, a predetermined amount of polyol C was charged and reacted at 80 ° C. for 4 hours with stirring to obtain a prepolymer A.
I got The NCO content of Prepolymer A was 24.0%. Hereinafter, similarly, prepolymers B, C, D, E, F, G, H, I, and K shown in Tables 1 and 2 were obtained.

[0039]

[Table 1]

[0040]

[Table 2]

In Tables 1 and 2, MDI: diphenylmethane diisocyanate storage stability at 15 ° C .: evaluated by appearance after one day ○ → clear × → turbidity, precipitation, precipitation, etc.

Examples 1 to 6, Comparative Examples 1 to 5 According to the formulation shown in Table 3, Cannon Viki
Using a multi-component low-pressure foaming machine manufactured by ng Co., Ltd., a flexible polyurethane slab foam was produced in the following manner. Raw material temperature 25 ±
Each component adjusted to 2 ° C. at a predetermined ratio of 4,500 rpm
The mixture was stirred and mixed at a rotation speed of, and continuously poured onto a conveyor having a width of 750 mm to form a slab foam block having a length of 2,000 mm and a height of 700 mm. The obtained polyurethane foam was allowed to stand for 24 hours after production, and then the foam was cut into 300 mm x 300 mm x 50 mm, and the physical properties were measured. Table 3 shows the results.

[0043]

[Table 3]

[0044]

[Table 4]

Method for measuring physical properties of foam Measurement of physical properties of foam was performed according to JIS K6400 (1997).
It went based on. The unit is as follows. Total density: kg / m ³ Hardness (25% ILD): N / 314 cm ² Sag factor: 65% ILD / 25% ILD value (larger, more supportive) Hysteresis loss:% Tensile strength: kPa Elongation: % Tear strength: N / cm Compression residual permanent set:% Flame retardancy: Measured by JIS K 6400 (1997) A method. Unit: mm / min

According to the present invention, it is possible to obtain a flexible polyurethane slab foam having a stable and uniform cell using a low-viscosity isocyanate, and the mechanical strength, the compression set, and the feel are good. . In addition, a flexible polyurethane slab foam having good flame retardancy was obtained without adding a flame retardant.

Examples 7 to 10 In the same manner as in Example 1, a flexible polyurethane slab foam was produced, and its physical properties were measured in the same manner. The results are shown in Table 5. As in Example 1, a good flexible polyurethane slab foam was obtained using a low-viscosity isocyanate. The mechanical strength, the permanent compression set, the feel and the flame retardancy were all good.

[0048]

[Table 5]

In Tables 3 to 5, foam state: evaluated by the state of the appearance of the foam after production ○ → good CR → cracked SE → depressed SH → shrinkage occurred

The slab foam obtained according to the present invention is particularly excellent in durability, supportability, flame retardancy, etc., and is used for cushioning materials for furniture such as sofas, clothing, cushioning materials for automobiles and railway vehicles, and automobile interiors. Wood, mattress, futon,
It is useful for beddings such as pillows, sound-absorbing materials, sound-insulating materials, home appliances, electronic components, industrial sealing materials, packing materials, daily necessities and the like.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Nagaoka 3-5-37 Tsunashimahigashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture (72) Inventor Takao Fukami 4-20-20, Kugenuma Beach, Fujisawa-shi, Kanagawa F-term (reference) 4J034 BA03 BA09 DA09 DA03 DB03 DB04 DB05 DB07 DB08 DC50 DG02 DG03 DG04 DG06 DG08 DG10 DG12 HA01 HA02 HA07 HA08 HA11 HA14 HC03 HC12 HC16 HC61 HC64 HC65 HC67 JA42 NA01 NA05 QA01 QA02 QA03 QB01 QB15 RA10 QA15 RA10

Claims (6)

[Claims] 1. A mixture of an organic polyisocyanate (A), a polyol (B), a catalyst, water as a foaming agent, a foam stabilizer, and other auxiliaries is continuously poured into a box or a conveyor and foamed by reaction. In the obtained flexible polyurethane slab foam, (a) the organic polyisocyanate (A) is composed of 60 to 98 parts by mass of diphenylmethane diisocyanate containing 20 to 50% by mass of the 2,4'-isomer, 2 to 4 nominal functional groups, and A prepolymer having an isocyanate group content of 23 to 33% by mass obtained by reacting 2 to 40 parts by mass of a polyoxyalkylene polyol having a hydroxyl equivalent of 200 to 2,500, and having an average number of functional groups of 2.
(B) the polyol (B) is a polyoxypropylene polyol having a terminal ethylene oxide cap having a nominal number of functional groups of 2 to 4 and an average hydroxyl equivalent of 1,000 to 2,500. (B1) and oxyethylene in oxyalkylene are 5
It is composed of a polyoxyalkylene polyol (B2) having a functional group number of 2 to 6 at 0% by mass or more and an average hydroxyl equivalent of 200 to 2,000, and its mass ratio is (B1) =
(B2) contains two components consisting of 0.5 to 25 with respect to 100, and (c) all isocyanate groups in the organic polyisocyanate (A) and all isocyanate-reactive groups in the isocyanate-reactive compound containing water. A flexible polyurethane slab foam having an equivalent ratio of 0.5 to 1.5. 2. A mixture of an organic polyisocyanate (A), a polyol (B), a catalyst, water as a foaming agent, a foam stabilizer, and other auxiliaries is continuously poured into a box or a conveyor and foamed by reaction. In the obtained flexible polyurethane slab foam, (a) the organic polyisocyanate (A) is 60 to 98 parts by mass of diphenylmethane diisocyanate containing 20 to 50% by mass of 2,4'-isomer, and a polynuclear body having three or more benzene rings. Group obtained by reacting 1 to 20 parts by mass of a polymethylene polyphenyl polyisocyanate consisting of 1 to 40 parts by mass of a polyoxyalkylene polyol having a nominal number of functional groups of 2 to 4 and an average hydroxyl equivalent of 200 to 2,500. A prepolymer having a content of 23 to 33% by mass, the average number of functional groups of the prepolymer being 2.
(B) the polyol (B) is a polyoxypropylene polyol having a terminal ethylene oxide cap having a nominal number of functional groups of 2 to 4 and an average hydroxyl equivalent of 1,000 to 2,500. (B1) and oxyethylene in oxyalkylene are 5
It is composed of a polyoxyalkylene polyol (B2) having a functional group number of 2 to 6 at 0% by mass or more and an average hydroxyl equivalent of 200 to 2,000, and its mass ratio is (B1) =
(B2) contains two components consisting of 0.5 to 25 with respect to 100, and (c) all isocyanate groups in the organic polyisocyanate (A) and all isocyanate-reactive groups in the isocyanate-reactive compound containing water. A flexible polyurethane slab foam having an equivalent ratio of 0.5 to 1.5. 3. The process for producing a flexible polyurethane slab foam according to claim 1, wherein the viscosity of the organic polyisocyanate (A) at 25 ° C. is 400 mPa · s or less. 4. An organic polyisocyanate (A) comprising 15
The method for producing a flexible polyurethane slab foam according to any one of claims 1 to 3, wherein the liquid is liquid at a temperature of 1 ° C for one day or more. 5. A polyoxypropylene polyol (B)
1) is a polyoxypropylene polyol having a terminal ethylene oxide cap having a nominal number of functional groups of 2 to 4 and an average hydroxyl equivalent of 1,000 to 2,500, and the primary hydroxyl group of the terminal hydroxyl group is 30 mol% or more. A method for producing a flexible polyurethane slab foam according to any one of claims 1 to 4. 6. A foam having a density of 15 to 80 k.
The method for producing a flexible polyurethane slab foam according to claim 1, wherein the g / m ³ , the ILD is 30 to 250 N / 314 cm ² , and the elongation is 100% or more.