JPH0126609B2 - - Google Patents

Description

[Detailed description of the invention]

(Industrial Application Field) This invention relates to a flexible polyurethane foam used in automobiles, furniture, bedding, or daily necessities. (Prior Art) Soft polyurethane foams have so far been produced with apparent densities in the range of 10 to 50 kg/m ³ , of which foams with apparent densities of 14 to 25 kg/m ³ are the mainstream. For foams in this apparent density range, there is generally a proportional relationship between apparent density and hardness, and the higher the apparent density, the greater the hardness.
Usually commercially available ones have a JIS hardness of 5.5 to 13.5 kg.
The form ranges from . Recently, there has been a strong demand for weight reduction in various application fields including the automobile field, and research has begun from various angles on technology that can stably produce foams with increased hardness without increasing apparent density. There is. As strategies for this, methods such as the combination of polyols having four or more functional functions, high isocyanate index, increasing the amount of water blended, and combination of polymer polyols are being considered. However, method (2) has the disadvantage that the strength and elongation properties and compression set properties decrease, and method (2) generates significant heat during the reaction, which tends to cause scorch inside the foam, and in some cases, there is a risk of ignition. There were some difficulties involved. Furthermore, the heat resistance of the obtained foam is poor in the other methods, and apart from the mold foam, scorch tends to occur easily in the slab foam, so none of the methods has reached the point where it can be used as a decisive factor. . On the other hand, as a polyol for polyurethane, 2,
A propylene oxide adduct of 2-bis(4-hydroxyphenyl)propane (hereinafter abbreviated as bisphenol A-PO adduct) alone or at least two
A technique for use in combination with a functional aromatic amine-based polyoxyalkylene polyol (hereinafter referred to as aromatic amine-based polyol) is known in JP-A-59-47223; The aim is to improve the heat resistance of foam. (Problems to be Solved by the Invention) The present invention overcomes the drawbacks of the prior art as described above, and has a rigid molecular structure and high viscosity that are normally unimaginable, as well as trifunctionality for soft foams. Bisphenol A- has poor compatibility with polyols
By making it possible to incorporate PO adducts, we aim to obtain a soft urethane foam that has well-balanced strength and elongation properties and has increased hardness without increasing the apparent density of the foam. . (Structure of the Invention) One component of the mixed polyol used in this invention is a propylene oxide adduct of 2,2-bis(4-hydroxyphenyl)propane. This is 2,2-bis(4-hydroxyphenyl)propane (hereinafter referred to as bisphenol A).
It is obtained by reacting 2 or more moles of propylene oxide (hereinafter referred to as PO) per mole. This bisphenol A-PO adduct is preferably one described in JP-A-59-47223, and is commercially available, for example, from Toho Chiba Chemical Co., Ltd.
BISOL-2P falls under this category. In addition, the aromatic amine-based polyol, which is another component of the mixed polyol used in this invention, has at least a bifunctional hydroxyl value (hereinafter abbreviated as OH value) of 200 to 700, and this is a known polyol. Aromatic monoamines such as aniline or 2,
4- and 2,6-tolylene diamine (TDA) and so-called crude TDA, 4,4'-diaminodiphenylmethane and polymethylene polyphenylene polyamines obtained by condensation of aniline with formalin, ortho- or meta- or paraphenylene diamine It is obtained by adding one or more alkylene oxides such as propylene oxide and ethylene oxide to one or more aromatic diamines and aromatic polyamines such as amines, meta- or para-xylylene diamines, and the free one At least a bifunctional polyol with substantially no residual primary or secondary amines, commercially available products include, for example, GR manufactured by Takeda Pharmaceutical Co., Ltd.
-30 falls under this category. The bisphenol A-PO adduct mentioned above is
It has poor compatibility with general-purpose polyols for soft foam, and even if the two are stirred and mixed, the two will degrade over time.
However, aromatic amine-based polyols have excellent compatibility with general-purpose flexible foam polyols, especially trifunctional polyols, and when these three are mixed and stirred, they not only form a uniform layer, but also form mixed polyols. Since it exhibits the effect of lowering the viscosity of the system, it also has the effect of significantly improving the mixing operation with other compounding agents, so it is an indispensable component. In addition, in order to make the effect of this aromatic amine-based polyol more effective, in order to lower the viscosity of the aromatic amine-based polyol itself and improve processability, the following are added in addition to the aromatic amines at the synthesis stage: These aliphatic glycols and the like can be used as co-initiators. For example, polyfunctional aliphatic glycols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, glucose, sorbitol, sucrose, aliphatic amines such as ethanolamine, diethanolamine, triethanolamine, ethylenediamine, etc. and aliphatic alkanolamines, and these co-initiators are preferably used in an equimolar or less amount relative to the aromatic amine. In this invention, as the trifunctional polyol for soft foam used, all known polyester polyols and polyether polyols having an OH value of 35 to 65 can be used, but in particular, polyester polyols and polyether polyols having an OH value of 56 to 65 can be used.
Polyoxypropylene ether polyol or polyoxyethylene propylene ether polyol is preferred. This invention is a technology characterized by increasing the hardness of a flexible urethane foam using a mixed polyol of a trifunctional polyol for softness, a bisphenol A-PO adduct, and an aromatic amine-based polyol. In this case, the usage ratio of each polyol is trifunctional polyol for flexible foam 84
0.2 to 8 parts by weight of bisphenol A-PO adduct, preferably 0.6 to 2 parts by weight, and 0.2 to 8 parts by weight of aromatic amine-based polyol, preferably 0.6 to 2 parts by weight, based on ~99.6 parts by weight. desirable. Note that the bisphenol A-PO adduct and the aromatic amine-based polyol are 0.6 to 1% of the aromatic amine-based polyol to 1 part of the bisphenol A-PO adduct.
It is desirable to use a ratio of 1.4, and optimally both are used in equal amounts. Although the hardness of foams made from these mixed polyols is clearly improved, the strength and elongation properties may be slightly reduced. When such a tendency is observed, it is preferable to add a small amount of diol (bifunctional polyol) to the mixed polyol. The diol used in this case has an OH value of 28
~280 (molecular weight 400~4000) preferably OH value 28~
112 (molecular weight 1,000 to 4,000) is suitable; as the molecular weight decreases, the resulting foam tends to shrink more easily. The amount of diol added is preferably in the range of 0.4 to 12 parts by weight per 100 parts by weight of the mixed polyol, and if it is less than 0.4 parts by weight, the effect of improving strength and elongation properties is poor. On the other hand, increasing the addition amount to 12 parts by weight or more is not preferable because it will adversely affect the compression set characteristics of the obtained foam. Even if a polymer polyol is used in place of the amine-based polyol, which is one component of the mixed polyol, the same effects can be obtained, namely, compatibility with the bisphenol A-PO adduct and increased hardness of the foam. All known polymer polyols can be used in this case, such as commercially available Mitsui Nisso POP31/28, 34/28, 32/45,
Examples include 36/24, 36/28, 40/45, etc. The amount of polymer polyol added is preferably in the range of 0.4 to 33 parts by weight based on 77 to 99.2 parts by weight of the trifunctional polyol for soft use; if it is less than 0.4 parts by weight, no hardening effect will be observed, and if it is more than 33 parts by weight, The heat generation temperature inside the foam increases significantly, which tends to cause scorch. Even when a polymer polyol is used, the effect of improving strength and elongation properties can be observed by using a diol in combination, so it is recommended to add it as necessary. This invention requires the use of a mixed polyol consisting of a trifunctional polyol, a bisphenol A-PO adduct, and an amine-based polyol or a polymer polyol as a polyol component. Based on the total amount of phenol A-PO adduct and amine-based polyol or polymer polyol,
An aromatic polyol having at least a difunctional OH group having an OH value of 28 to 850 can be used in combination within a range of 40% or less. at least bifunctional
As aromatic polyols having an OH group and an OH value of 28 to 850, (a) monocyclic or polycyclic aromatic compounds having at least two hydroxyl groups such as hydroquinone, pyrogallol, and 4,4'-isopropylidenephenol; Polyols with a hydroxyl value of 28 to 600 obtained by adding alkylene oxides such as propylene oxide and ethylene oxide to aromatic polybasic acids such as propylene oxide and ethylene oxide. Hydroxyl value 28~ obtained by adding alkylene oxide
500 polyols (c) metaxylylene glycol, paraxylylene glycol (d) aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, or their anhydrides or lower alcohol esters, and/or adipic acid, The acid component is aliphatic dicarboxylic acid such as succinic acid, and ethylene glycol, 1,
Aliphatic polyols such as 4-butylene glycol and trimethylolpropane, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol β, β, β', β'-tetramethyl-
2,4,8,10-tetraoxaspiro (5,
5) -A hydroxyl value of 28 to 28 containing an alicyclic polyol such as -undecane-3,9-diethanol or the polyol of the above (a), (b), or (c) as a polyol component
There are 450 polyester polyols, etc. As the polyisocyanate component used in this invention, all known at least difunctional polyisocyanates can be used, but aromatic polyisocyanates are particularly preferred, such as 2,
4- and 2,6-tolylene diisocyanate (TDI), orthotoluidine diisocyanate (TODI), naphthylene diisocyanate (NDI),
Xylylene diisocyanate (XDI) 4,4'-diphenylmethane diisocyanate (MDI) and carbodiimide-modified MDI (e.g. Nippon Polyurethane Co., Ltd. MTL), polymethylene polyphenyl isocyanate (PAPI), polymeric polyisocyanate (e.g. Sumitomo Bayer Urethane 44V) etc. can be used alone or in combination. In the present invention, when a urethane foam is produced by reacting a polyol with an isocyanate or the like, the isocyanate index is preferably 103 to 130, but can be increased or decreased as appropriate based on desired physical properties. Further, the present invention can be applied not only to soft slab forms but also to mold forms. Furthermore, in this invention, in order to produce the flexible polyurethane foam, catalysts, blowing agents, foam stabilizers, and flame retardants, pigments, fillers, etc. are used as necessary, but there are no particular restrictions on these, and known ones may be used. are all available. (Example) Hereinafter, a detailed explanation will be given based on an example. Example 1 980 g of trifunctional polypropylene glycol (Mitsui Nisso #3050, OH value 56), 1.6 g of tin catalyst (Stanocto manufactured by Yoshitomi Pharmaceutical Co., Ltd.), 10 g of silicone foam stabilizer (SH-190 manufactured by Toray Silicon Co., Ltd.), and amine catalyst A mixed solution was prepared by adding 1.2 g of 1-methyl-4(dimethylaminoethyl)piperazine. To this, 10 g of BISOL-2P (OH value 320) manufactured by Toho Chiba Chemical Co., Ltd. was added as a bisphenol A-PO adduct, and GR-30 manufactured by Takeda Pharmaceutical Co., Ltd. was used as an aromatic amine-based polyol.
Add 10g (OH number 400) and 38g deionized water,
Next, tolylene diisocyanate (manufactured by Mitsui Nisso)
After adding 530 g of TDI-80) and immediately stirring for 7 seconds using a homomixer, the mixture was allowed to foam freely. At this time, a thermometer was inserted into the center of the foam to measure the maximum exothermic temperature. After that, the thermometer was removed, the foam was heated for 10 minutes in a constant temperature bath at 100℃, and after being left to cool for 24 hours, the hardness, rebound resilience, and
Compressive residual strain, tensile strength, and
Elongation rate, tear strength, and apparent density were measured using the method of ASTMD1564-64T. The results are shown in Table 1. Comparative example 1 Take 1000g of polypropylene glycol,
A foam was obtained in exactly the same manner as in Example 1 without adding BISOL-2P and GR-30, and the physical properties were measured. The results are also listed in Table 1. Examples 2 to 5 Forms having the formulations shown in Table 2 were prepared in exactly the same manner as in Example 1, and the results of measuring the physical properties are also listed in Table 1. Further, the hardness/density ratio of each Example was expressed as an index, with the ratio of Comparative Example 1 being 100.

【table】

【table】

[Table] Examples 6 to 9 Using Takeda Pharmaceutical Actol #3000 (OH value 56) as trifunctional polypropylene glycol,
Freon 11 (manufactured by Mitsui Chlorochemical) as a foaming agent
A foam was prepared according to the formulation shown in Table 3 in the same manner as in Example 1 except that N-methylmorpholine (abbreviated as NMM) and trimethylpentadiamine (abbreviated as TMPDA) were used as amine catalysts, and the physical properties were determined. Measurements were carried out and the results are shown in Table 4. Comparative Example 2 BISOL-2P and GR in the same manner as Examples 6 to 9
A foam without addition of -30 was prepared and its physical properties were measured and are also listed in Table 4.

【table】

【table】

[Table] Example 10 Trifunctional polyol HF3013 (Daiichi Kogyo Seiyaku Co., Ltd.,
OH number 56,) 62 parts by weight, polymer polyol
36/24 (manufactured by Mitsui Nisso, OH value 42) 33 parts by weight, 1 part by weight of BISOL-2P (manufactured by Toho Chiba Chemical, OH value 320) as a bisphenol A-PO adduct, aromatic amine-based polyol GR-30 (Manufactured by Takeda Pharmaceutical Company,
OH value 400) 1 part by weight, bifunctional polyol (Asahi Denka Diol 2000, OH value 56) 3 parts by weight, silicone foam stabilizer (Nippon Unicar L5740M) 1 part by weight, tin catalyst (Yoshitomi Pharmaceutical Stanoct) A liquid A was prepared by mixing 0.02 parts by weight of the flame retardant TH101 (manufactured by Olin Corporation) and 7 parts by weight. On the other hand, 4.5 parts by weight of deionized water, 0.14 parts by weight of triethylenediamine as an amine catalyst and trifunctional polyol P-333 (manufactured by Daiichi Kogyo Seiyaku, OH value 56)
A liquid C was prepared by adding 15 parts by weight. 39.3 g of C liquid to 216 g of A liquid obtained in this way,
Tolylene diisocyanate (TDI-80 manufactured by Mitsui Nisso) was added as liquid B, stirred and mixed for 7 seconds using a homomixer, and foamed by injection into a mold provided with a vent hole of 32 x 32 x 7 cm. After foaming was completed, the mold was heated in an oven at 150° C. for 15 minutes, left to cool, and then removed from the mold. The physical properties of the obtained mold form were measured in the same manner as in Example 1, and the results are shown in Table 5. Comparative Example 3 Example 10 without blending the bisphenol A-PO adduct, aromatic amine-based polyol, and bifunctional polyol, and using trifunctional polyol
65 parts by weight of HF3013, polymer polyol 36/24
A mold form was prepared in exactly the same manner except that 35 parts by weight was changed and TDI-80 was changed to 85 g.The results of measuring the physical properties are also shown in Table 5.

[Table] (Effects of the invention) By using a trifunctional polyol for soft foam together with a bisphenol A-PO adduct and an aromatic amine-based polyol, (1) Not only can the viscosity of the bisphenol A-PO adduct be uniformly dissolved, but it can also be lowered to a viscosity range that is easy to use for one shot form. (2) There is no problem in compatibility with known compounding agents such as diols other than trifunctional polyols and flame retardants.
It can be applied to the production of molded forms as well as slab forms. (3) The obtained foam has excellent effects such as being able to improve hardness by approximately 1 kg/314 cm ² or more without reducing tensile strength, elongation, tear strength, or compressive residual strain properties or increasing density. Therefore, the technology of the present invention can be applied to a wide range of applications such as cushioning materials for automobiles and furniture, insulation materials, and daily miscellaneous goods.

Claims (1)

[Claims] 1 In a flexible polyurethane foam obtained by reacting a polyol component having at least a difunctional hydroxyl group and an at least difunctional polyisocyanate component in the presence of a blowing agent, a catalyst, and a foam stabilizer, the polyol component 3 for soft foam as
The main component is a functional polyol, and 2,2-
A high-hardness flexible polyurethane characterized by using a mixed polyol containing a propylene oxide adduct of bis(4-hydroxyphenyl)propane, an aromatic amine-based polyoxyalkylene polyol, or a mixed polyol containing a polymer polyol further added thereto. form.