JPH0418434A - Production of flexible polyurethane foam - Google Patents

Abstract

PURPOSE:To efficiently produce a flexible polyurethane foam having excellent physical properties of foam by reacting a specific polyhydroxy compound with a polyisocyante compound in the presence of a specific foam stabilizer. CONSTITUTION:(A) A polyhydroxy compound consisting of a mixed polyether polyol (modified material) capable of satisfying 35-75mg KOH/g hydroxyl value, 25-60wt.% ethylene oxide content and >=40mol% terminal primary OH group in total OH group is reacted with (B) a polyisocyanate compound in the presence of (C) a catalyst and (D) a foam stabilizer expressed by formula I [R is monovalent hydrocarbon containing no aliphatic unsaturated hydrocarbon; a is >=7; Q is formula II or/and formula III (y<1> and y<2> are >=4 when oxyalkylene group is alone and >=1 and y<1>+y<2>>=4) when oxyalkylene group is two kinds of combination] of >=0.3 pts.wt. based on 100 pts.wt. component A.

Description

[Detailed description of the invention] [Purpose of the invention]

[Industrial Application Field] The present invention relates to a method for producing flexible polyurethane foam, and more specifically, a method for producing a flexible polyurethane foam, and more specifically, a method for reacting a specific polyhydroxy compound and a polyisocyanate compound in the presence of a catalyst, a blowing agent, and a specific foam stabilizer. The present invention relates to a method for producing flexible polyurethane foam. [Prior art] Flexible polyurethane foam has excellent elasticity, so it is widely used in cushions and backrest materials for furniture and automobiles, but molded 7 ohm foam is mostly used for automobiles. be. Techniques for producing 2-ohm soft urethane molds are broadly classified into cold curing methods and hot curing methods, each of which has advantages and disadvantages as described below. That is, the foam obtained by the cold cure method is commonly known as HR (High
h Resilience) 7 ohm, and has excellent physical properties such as high impact resilience and SAG coefficient.Moreover, the molded surface can be cured at low temperatures, the curing time is short, and the foam does not cause cracks or shrinkage. Although it has the advantage that it is difficult to use and has a high product yield, it has the disadvantage that it can only be used for high-density cooking because wet setting becomes extremely poor especially when the density of the foam is reduced. On the other hand, in the hot curing method, the curing temperature during molding is high and the curing time is long, and cracks, shrinkage,
Although it has drawbacks such as loose skin defects and low product yield, it has the advantage of producing low-density products with better compression set (particularly wet set) than the cold cure method. Therefore, the low density foam obtained by this method is used for backrest materials, and the medium to high density foams are used for cushions. In recent years, the product yield of cushions and backrest materials for automobiles has been decreasing due to the pursuit of maximum interior comfort and comfort.Especially with hot cure, which has slightly poor moldability, it is difficult to improve the yield. has become a major issue. The cause of the decrease in yield is that a large number of various insert materials are used,
In addition, this is thought to be due to the fact that the shape of the product has become more and more complex, and the partial variation in mold temperature within the same mold, especially seen in three-piece molds. In addition, the low-density, low-hardness foams used for backrest materials have mostly been produced with fluorocarbons (chlorofluorocarbons, CFCs) in them. The development of manufacturing methods that do not require (or can significantly reduce the amount used) is becoming an important theme. In addition, in order to obtain a low density, low hardness foam, a long curing time is required, resulting in poor wet setting. Therefore, it has the following properties: (1) Good yields can be obtained even for complex-shaped products. (2) Short curing time; (3) Good foam properties (especially wet set) even at low density. (0) In the production of low-density foam, CFCs are not used or their use can be significantly reduced; (6) On the other hand, if we could develop a method for manufacturing flexible polyurethane foam that can be used for cushioning and has a high density and high hardness,
A great deal of industrial success can be expected. Regarding (1) to (6) above, several solutions have been proposed so far for each individual problem (for example, regarding (1), Japanese Patent Application Laid-Open No. 501197, -5715, (2) in JP-A-54-37198, (3) in Time+71-31536, (4) in JP-A-57-182714, JP-A-1989- No. 115919, and regarding (5), JP-A-56-67330, JP-A-57-195725, and JP-A-59-1001.
Regarding Publication No. 25, (6), Special Publication No. 4B-24255
Publication No. 48-8880, etc.) are (1) to (
No method has been proposed that can solve all of the problems in 6) at the same time. [Problems to be Solved by the Invention] The present invention solves all of the problems (1) to (6) as described above, and produces flexible polyurethane foam with excellent foam properties in an extremely efficient manner regardless of the product shape or use. The objective is to provide a method that can be manufactured easily.

[Structure of the invention]

[Means and effects for solving the problems] The present invention provides a method for producing flexible polyurethane foam by reacting a polyhydroxy compound and a polyisocyanate compound in the presence of a catalyst, a blowing agent, and a foam stabilizer. The above problem was solved by using a polyhydroxy compound and a specific foam stabilizer. That is, in the present invention, A, a polyhydroxy compound having a hydroxyl value of 35 to 75+++gKOH
/g ethylene oxide content 25-80% by weight total O
A mixed polyether polyol or a modified product thereof having a content of 40 mol% or more of terminal primary OH groups in H groups is used; B. A compound represented by the following formula as a foam stabilizer ([R
5iO] a [Q] l b (hereinafter referred to as the margin) to 100 parts by weight of the above mixed polyether polyol
．． It is characterized in that it is used in a proportion of 3 parts by weight or more. The polyhydroxy compound used in the present invention consists of a mixed polyether polyol containing two or more types of polyether polyols or a modified product thereof. That is, the mixed polyether polyol of the present invention or its modified product is prepared by adding a starting material having two or more active hydrogens, in the presence of a basic catalyst,
Addition polymerization of alkylene oxide to a mixture of two or more individual starting materials in the same manner as described above and modified products obtained by graft polymerizing ethylenically unsaturated monomers (hereinafter also referred to as polymer polyols). Examples of the starting materials include polyhydric alcohols such as propylene glycol, ethylene glycol, butanediol, hexanediol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, diglycerin, sorbitol, sugar, monoethanolamine, Any of amines such as jetanolamine, triethanolamine, ethylenediamine, and triethylenediamine can be used. Particularly preferred starting materials are compounds having three active hydrogen atoms such as glycerin and trimethylolpropane.As the alkylene oxide, any of ethylene oxide, 2-propylene oxide, butylene oxide, styrene oxide, etc. can be used. However, the most preferred examples are ethylene oxide (hereinafter abbreviated as EO) and propylene oxide (hereinafter abbreviated as PO). In addition, as the modified product, an ethylenically unsaturated monomer such as acrylonitrile (hereinafter abbreviated as AN) or styrene (hereinafter abbreviated as ST) is appropriately grafted onto the polyether polyol obtained from the starting material and the alkylene oxide. Polymerized products can be used. These mixed polyether polyols or modified products thereof need to satisfy the following requirements. That is, the hydroxyl value is 35 to 75 gKOH/, preferably 45 to 60
gKOH/g, the weight ratio of EO and other fullylene oxides is 25-80:75-4o, and more than 40 mol%, preferably 50-85 mol% of the total OH groups are terminal primary OH groups. It is necessary to prepare it so that it becomes. If the hydroxyl value is lower than 35mgKOH/g,
Although the appearance of the foam is good, the compression set is poor, making it impossible to obtain a foam that is suitable for use as a foam material.On the other hand, if the hydroxyl value is higher than 75mgKO)l/g, the cell openness and impact resilience will deteriorate. , the compression set is poor and a good form cannot be obtained. Furthermore, when the ethylene oxide content is less than 25% by weight, the resulting foam becomes oily foam, has poor compression set and impact resilience, and has an ethylene oxide content of less than 8% by weight.
If it is more than 0% by weight, the cells of the foam become coarse and sometimes collapse. Furthermore, when the terminal primary OH group is less than 40 mol%,
The skin of the foam is weak and the curing time is long, making it impractical. Next, in the present invention, a specific compound represented by the following general formula is used as a foam stabilizer. ([R25iO]a[Q])bIn the above general formula,
[R25iO]a preferably has a molecular weight of 500 to 10,000 and a content of 20 to 50% by weight, and Q
has a molecular weight of 300 to 10,000, and a content of 80 to 50
Preferably, R is a monovalent hydrocarbon containing no aliphatic unsaturated bonds and having 1 to 2 carbon atoms.
0, especially a lower alkyl group such as CH3 or a phenyl group. Moreover, Q is (CaH40)yl, (C3HiO)
It is an oxyalkylene group consisting of a combination of yl or tsure, especially one (Cz) 0π1i(3H60)y'
(y', !2:1 or more, 7L+72=4 or more), the molecular weight of such a bubble stabilizer is 11
1500 (preferably 1 or more; the upper limit is not particularly limited; however, if the molecular weight is too high, the viscosity will increase, so although the desired foam properties can be obtained, it is impractical in one work aspect. Note that if R, a, yl, yt, and b in the general formula are outside the specified ranges, the foam surface may become rough, cracked, collapsed, or shrink, or a normal foam may not be obtained. Or, even if a good foam can be obtained, the result will be a foam that lacks practicality, such as poor impact resilience and compression set.Next, the amount of the foam stabilizer to be blended is 0.3 parts by weight or more per 100 parts by weight of ether polyol, 0
．． Preferably, it is 5 to 3 parts by weight. If it is less than 0.3 parts by weight, the cells of the foam may become coarse,
Cracks, collapse, etc. occur. Note that the foam stabilizer represented by the above general formula used in this invention may be used in combination with a foam stabilizer commonly used in the art, if necessary. Examples of the bubble stabilizer used in combination include compounds represented by the following general formula. Ra5iO(RzSiO) a (R3iO) b
5iR3YO(C,H◆0)yl (CaH60)Te1
R Polyisocyanate compounds used in the present invention include tolylene diisocyanate, phenylene diinocyanate, diphenylmethane diisocyanate, etc.
Examples of catalysts include triethylene diamine and its formate salts, amine catalysts such as dimethylethanolamine, tetramethylhexamethylene diamine, N-methylmorpholine, and N-ethylmorpholine, stannath octoate, dibutyl tin laurate, etc. Examples include tin-based catalysts. In addition, water is usually used as a blowing agent, but in some cases, trifluorofluoromethane, decofluoromethane,
It is also possible to blend low-boiling point solvents such as methylene chloride, and in addition, pigments, flame retardants, antistatic agents,
Additives such as a crosslinking agent may also be added, and the raw materials other than the polyether polyol and the foam stabilizer and the molding method are not particularly limited. As a method for producing flexible polyurethane foam, any conventionally known method can be applied. In this way, the polyurethane foam obtained by the present invention has extremely good compression set (especially wet set), so it can be lowered in density and hardness than the conventional hot curing method. Therefore, it is possible to produce a practical low-hardness foam without using fluorocarbons at all or with a significant reduction in the use of fluorocarbons. On the other hand, by using the above-mentioned polymer polyol as a compounding component, it is possible to increase the hardness, and a wide range of physical properties can be obtained by changing the compounding composition and compounding ratio. Furthermore, compared to the conventional method, the catalyst range and mold temperature range during raw material injection are extremely wide in the present invention, so there is no need to strictly control the amount of catalyst and mold temperature as in the conventional method, and it is superior in workability. Instead, curing time is fast, which greatly improves productivity. [Examples] Examples and effects of embodiments of the invention will be described below using Examples and Comparative Examples. However, the examples are merely for explanation and are not intended to limit the invention idea. Unless otherwise specified, the values shown are parts by weight or % by weight. Examples 1-10 and Comparative Examples 1-11 Various polyether polyols, polymer polyols, and foam stabilizers (see Tables 1.2 and 3) used in Examples and Comparative Examples were prepared by known methods. Next, 100 parts of various polyether polyols, 1.2 parts of bubble stabilizer, 5.0 parts of water, 0.3 parts of TEDA-L33 (manufactured by Tosoh, 33% dipropylene glycol solution of triethylene diamine), and Stanus octoate. Pour 0.13 parts into a container and adjust the temperature inside the container to 22°C.
After pre-preparing for seconds, TD4-80 (tolylene diincyanate manufactured by Mitsubishi Kasei) at 22°C was added in a stoichiometric amount (NCO
index 100), stir for 5 seconds, and preheat to 40°C.
400(W)X400(L)X100(H) with temperature controlled to
It was injected into a +ms aluminum mold and formed into a foam. Approximately 100 seconds after the addition of TDI-80, the mold was placed in a hot air oven at 170° C. for 8 minutes for curing to obtain a flexible polyurethane mold form. The physical properties of this foam were measured according to JIS K-[1401, and the state of the foam was examined. The results are shown in Tables 4 and 5. Examples 11 to 18 - Test of catalyst amount - Foaming was carried out in the same manner as in Example 2 except for the catalyst amount,
Table 6 shows the results of determining the relationship between the amount of catalyst, the physical properties of the foam, and the state of the foam. -Test on catalyst amount- Formation was performed in the same manner as in Comparative Example 1 except for the catalyst amount, and the relationship between the catalyst amount, foam physical properties, and foam state was determined. The results are shown in Table 7. . Examples 19 to 23 Comparative Examples 18 to 21 - Test of Mold Temperature Range Forming was carried out under the same conditions as in Example 2 and Comparative Example 1, except that only the mold temperature at the time of raw material injection was changed. The obtained foam was further cut to examine the appearance and the state of the core, and the results are shown in Table 8. Examples 24-25. Comparative Example 22 - Cure Test - Formation was carried out under the same conditions as Examples 2 and 17 and Comparative Example 3, with only the curing time being changed. Table 9 shows only the state of the foam when it was removed from the mold. Examples 26 to 29 Comparative Example 23 - Bubble stabilizer mixing test Except for the type and amount of the bubble stabilizer, foaming was carried out in the same manner as in Example 1, and the foam physical properties and foam state were examined, and the results are shown in Table 10. Indicated. Example 30 and Comparative Example 24 - Moldability test - Using a foaming machine, a moldability test was conducted using a foaming mold instead of a complex mold type in which it is difficult to obtain the best form, and the defective rate of the obtained foam was determined. The results are shown in Table 11. The following can be seen from the results shown in Tables 4 to 11 above. (1) Form physical properties Examples 1 to 10, Comparative Examples 1 to 11 (Tables 4 and 5) Among the examples according to the present invention, when no polymer polyol was blended, the hardness was 4 to 5 kg lower, and the compression permanent It is possible to obtain a product with extremely excellent distortion (especially weight set),
CFC-free or the use of CFCs can be significantly reduced.
Furthermore, lower density is also possible. In the example of the low density formulation, the set value is 35K in core density value according to the prior art.
g/layer 3. Moreover, when a polymer polyol is blended, a high hardness foam can also be obtained. (2) Catalyst amount control range Examples 11-18, Comparative Examples 12-17 (Tables 6 and 7) It can be seen that the method of the present invention is incomparably wider than the conventional method. (3) Mold temperature control range Examples 18 to 23, Comparative Examples 18 to 21 (Table 8) While the conventional method is limited to around 40°C, the method of the present invention has a wide range of 30 to 60°C. Good results have been obtained over a wide range of temperatures. (4) Curing properties Examples 24 to 25, Comparative Example 22 (Table 9) In the examples of the present invention, demolding can be performed in about 172 hours compared to the conventional method, speeding up the process. (5) Moldability (Yield) Example 30, Comparative Example 24 (Table 11) While the conventional method resulted in about half of the forms having some sort of defect, the method of the present invention had a defective rate of only 2%. The result was extremely excellent. (Leaving space below) Table-1 Preparation table of polyether polyol (PEPO)-1 Preparation CM) table of polyether polyol (PEPO)-
1 Preparation of polyether polyol (PEPO) Table 2 Preparation of mixed polyether polyol (PEPf kidney x) Mixed polyether polyol CP'FPCJ* + =
) Preparation Table-4 Foam Physical Properties (1) ■ = Very Good O: Good Δ: Slightly Poor x 6 Poor × × = Totally Poor Wet Set: 50°C 95R) 1%, 22 hours Table-3 Foam Stabilizer Preparation Table - 3 Preparation Table of Bubble Stabilizer - 4 Form Physical Properties (1) C Note) ■ = Very Good O: Good Δ: Slightly Poor XX = Totally Poor Wet Set: 50°C, 95RH%, 22 hours ×: Failure table-5 Form physical properties (2) Table-6 Catalyst amount test table-6 Catalyst amount test G-table-5 Foam physical properties (2) C table-7 Catalyst amount test table-8 Mold temperature Frog test chart Cure test O mark ○ mark △ mark × mark × × mark Removal from the mold Very good removability from the mold Good removability from the mold Very skin or very little skin attached to the mold. Adhesive skin fully adheres to the mold and cannot be removed from the mold Surface moldability test table-10 Bubble stabilizer mixing test

【Effect of the invention】

The method of the present invention breaks the conventional wisdom in the industry that compression set (particularly wet set) deteriorates when foam density is lowered, and makes it possible to produce low-density flexible polyurethane foam with good compression set. , those with good curing properties have high hardness, narrow catalyst width and mold temperature range,
Moreover, it breaks down the conventional wisdom that product yields are low, and can stably produce foams with very good physical properties in a short period of time. Furthermore, since soft foam can be obtained without using fluorocarbons, it can also contribute to environmental conservation. On the other hand, if a polymer polyol is used as the polyhydroxy compound, it is possible to increase the hardness, and a wide range of physical properties can be obtained depending on the composition, making it suitable for a wide range of applications. Patent applicant Daiichi Kogyo Seiyaku Co., Ltd.

Claims (1)

[Claims] A polyhydroxy compound and a polyisocyanate compound,
In the method of producing flexible polyurethane foam by reacting in the presence of a catalyst, a blowing agent, and a foam stabilizer, A. As a polyhydroxy compound, hydroxyl value 35 to 75 mgKOH/g Ethylene oxide content 25 to 60% by weight based on total OH groups , using a mixed polyether polyol or a modified product thereof satisfying 40 mol% or more of terminal primary OH groups; B. a compound represented by the following formula as a foam stabilizer {[R_
2SiO]a[Q]}b However, in the formula, R represents a monovalent hydrocarbon group containing no aliphatic unsaturation. a represents an integer of 7 or more. Q is (C_2H_4O)y^1, (C_3H_6O)y
Represents an oxyalkylene group consisting of ^2 alone or a combination thereof. When y^1 and y^2 are the oxyalkylene group alone,
Each represents an integer of 4 or more, or when the oxyalkylene group is a combination of two types, each is an integer of 1 or more, and the sum of the numbers y^1+y^2 is 4 or more. b represents an integer of 4 or more. 0 per 100 parts by weight of the above mixed polyether polyol
．． A method for producing flexible polyurethane foam, characterized in that it is used in a proportion of 3 parts by weight or more.