JPH0216330B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing polyurethane. More specifically, the present invention relates to polyurethanes using novel polymer polyols and, in particular, to methods for producing polyurethanes by the RIM method. It has been known to produce polyurethane by reacting a polymer polyol produced by polymerizing an ethylenically unsaturated monomer in a high molecular weight polyol in the presence of a radical generator with an organic polyisocyanate. However, it has traditionally been called "polymer polyol" and is obtained by polymerizing ethylenic monomers among high molecular polyols such as polyoxypropylene polyol and polyoxyethylene polyol, which are produced in large quantities. The polyurethane produced using this method has the disadvantage of high water absorption, and its physical properties are not necessarily satisfactory. The present inventors have arrived at the present invention as a result of intensive studies on a method for producing a polymer polyol that does not have the above-mentioned problems. That is, the present invention provides a method for producing polyurethane by reacting an organic polyisocyanate and a polyol, if necessary in the presence of a blowing agent, which comprises an ethylenically unsaturated monomer as at least a part of the polyol, and (A) polyoxypropylene. and/or a polyol composition comprising polyoxyethylene polyol and (B) polytetramethylene ether glycol; and a method for producing polyurethane (first invention); and producing the polyurethane described above. Using the above polymer polyol in the method
This is a method for producing high-density polyurethane (second invention) characterized by molding by RIM method. The polytetramethylene ether glycol (B) used in the production of the polymer polyol used in the present invention can be hydrolyzed by a conventional method such as ring-opening polymerization of tetrahydrofuran in the presence of an acidic polymerization catalyst such as a Lewis acid. The following can be mentioned. The catalyst includes AlCl ₃ ,
FeCl ₃ , SnCl ₄ + HCl (or instead of HCl
Conventionally used agents include CE ₃ COOH or SOCl ₂ ), fluorosulfuric acid, perchloric acid and acetic anhydride, boron trifluoride, hydrogen borofluoride, acetic anhydride and boron trifluoride, and sulfur trioxide. Also, those described in the Journal of the Japan Rubber Association, Vol. 45 (1972), pages 447-448, can be used. Also, Japanese Patent Publication No. 52-32798 using a super strong acid-acetic anhydride system as a catalyst,
The polytetramethylene ether glycol obtained by the method described in Publication No. 53-28195 has a molecular weight of
Preferably, the distribution is narrow. The hydroxyl value of polytetramethylene ether glycol is usually 22 to 110, preferably 35 to 75. The polyoxypropylene and/or polyoxyethylene polyol (A) used in the production of the polymer polyol used in the present invention includes polyhydric alcohols, amines, polyhydric phenols,
It is a compound with a structure in which propylene oxide and/or ethylene oxide is added to an active hydrogen atom-containing compound such as polycarboxylic acid. The above polyhydric alcohols include ethylene glycol, propylene glycol, 1.4-butanediol, 1.6-
Examples include hexanediol, diethylene glycol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, and sucrose. As amines, monoamines such as ammonia and butylamine;
Aliphatic polyamines such as ethylenediamine, trimethylenecyamine, diethylenetriamine; alicyclic polyamines such as piperazine, N-aminoethylpiperazine; phenylenediamine, tolylenediamine, xylylenediamine, diphenylmethanediamine, polyphenylmethanepolyamine, etc. aromatic polyamines and monoethanolamines,
Examples include alkanolamines such as diethanolamine and triethanolamine. Examples of polyvalent phenols include polyvalent phenols such as pyrogallol and hydroquinone, as well as bisphenols such as bisphenol A. Examples of polycarboxylic acids include aliphatic polycarboxylic acids such as succinic acid and adipic acid; and aromatic polycarboxylic acids such as phthalic acid, terephthalic acid and trimellitic acid. Two or more kinds of the above-mentioned active hydrogen atom-containing compounds can also be used. The method for adding propylene oxide or ethylene oxide to the active hydrogen atom-containing compound may be any conventional method, and either block or random addition method may be used. Preferred compounds in (A) are compounds having a structure in which propylene oxide or propylene oxide and ethylene oxide are added to a polyhydric alcohol, and particularly preferred are compounds in which propylene oxide is added to a polyhydric alcohol (especially propylene glycol, glycerin, trimethylolpropane). and ethylene oxide, especially polyoxypropylene/polyoxyethylene polyols containing terminal oxyethylene groups (chip type and balanced type). The terminal oxyethylene group content is usually 8 to 30% by weight, preferably 10 to 25% by weight.
Weight%. If the terminal oxyethylene group content is less than 8% by weight, the curing properties during polyurethane production will be poor, and if it exceeds 30% by weight, the water absorption of the polyurethane will increase. Furthermore, the content of oxyethylene groups in (A) is 10 to 35% by weight. In the polyol composition, the hydroxyl value of (A) polyoxypropylene and/or polyoxyethylene polyol is 150 or less, preferably 15-60, more preferably 20-45. If a polymer polyol obtained with a hydroxyl value exceeding 150 is used in a urethane molded product, the molded product will have poor elasticity. (A) in the polyol composition is usually 20 to 95% (wt%
represents. The same applies below) Preferably 30 to 90%, particularly preferably 50 to 80%, and (B) is usually 5 to 80%, preferably 20 to 50%. If (A) is less than 20%, the fluidity of the polyol will be poor and the physical properties (especially temperature characteristics) of the polyurethane will be poor. When (B) is less than 5%, the water absorption of the polyurethane is large and unsuitable, and furthermore, the physical properties are poor and insufficient, and when it exceeds 80%, the fluidity of the polyol is poor and the physical properties of the polyurethane are also deteriorated. Ethylenically unsaturated monomers used in the production of the polymer polyol used in the present invention include:
The following can be mentioned. (a) Acrylic acid, methacrylic acid and their derivatives: acrylonitrile, methacrylonitrile, acrylic acid, methacrylic acid and their salts, methyl acrylate, methyl methacrylate,
Dimethylaminoethyl methacrylate, acrylic amide, methacrylic amide, etc. (b) Aromatic vinyl monomers: styrene, α-methylstyrene, etc. (c) Olefinic hydrocarbon monomers: ethylene, propylene, butadiene, isobutylene, isoprene, 1,4-pentadiene, etc. (d) Vinyl ester monomer: vinyl acetate, etc. (e) Vinyl halide monomers: vinyl chloride, vinylidene chloride, etc. (f) Vinyl ether monomers: vinyl methyl ether, etc. Among these, preferred are acrylonitrile, methyl methacrylate, styrene, and butadiene, and particularly preferred are acrylonitrile and a combination of acrylonitrile and styrene. The ratio of the polyol composition to the monomer in the polymer polyol can vary over a wide range, but is usually 2 to 70 parts by weight of ethylenically unsaturated monomer (or polymer) per 100 parts by weight of the polyol composition.
Parts by weight, preferably 5 to 40 parts by weight. When polymerizing a mixture of styrene and acrylonitrile, the blending ratio of styrene:acrylonitrile is preferably 10:90 to 60:40 (weight ratio). The preparation of polymeric polyols from polyol compositions and ethylenically unsaturated monomers is carried out in conventional manner. For example, in a polyol composition, an ethylenically unsaturated monomer is polymerized using a catalyst (such as a radical generator).
(U.S. Pat. No. 3,383,351,
Special Publication No. 39-24737, Special Publication No. 47-47999, Publication No.
No. 50-15894) or a method of graft polymerizing a polyol composition of a polymer obtained by prepolymerizing the above monomers in the presence of a radical generator (Tokuko Sho
47-47597). The former method is preferred. As the organic polyisocyanate used in the present invention, those conventionally used in polyurethane production can be used. For example, aliphatic polyisocyanates (hexamethylene diisocyanate, lysine diisocyanate, etc.), alicyclic polyisocyanates (hydrogenated diphenylmethane diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, etc.), aromatic polyisocyanates [tolylene diisocyanate (TDI)] ,
diphenylmethane diisocyanate (MDI), naphthylene diisocyanate, xylylene diisocyanate, etc.] and mixtures thereof. Preferred among these are aromatic diisocyanates, particularly preferred are TDI,
It is MDI. These polyisocyanates are crude polyisocyanates, such as crude TDI, crude
MDI [crude diaminodiphenylmethane {condensation product of formaldehyde and aromatic amine or mixture thereof: mixture of diaminodiphenylmethane and a small amount (e.g. 5 to 20% by weight) of trifunctional or higher functional polyamine}]: polyallylpolyisocyanate (PAPI)] or modified polyisocyanates, such as liquefied MDI (carbodiimide modification, trihydrocarbyl phosphate modification, etc.) or excess polyisocyanate (TDI, MDI
It can also be used as a free isocyanate-containing prepolymer obtained by reacting a polyol with a polyol, or they can be used in combination (for example, a modified polyisocyanate and a prepolymer are used together). The polyols used in the production of the above prepolymer include polyols with an equivalent weight of 30 to 200;
For example, glycols such as ethylene glycol, propylene glycol, diethylene glycol, and dipropylene glycol; triols such as trimethylolpropane and glycerin; high functional polyols such as pentaerythritol and sorbitol; and alkylene oxides thereof (ethylene oxide and/or propylene oxide). Additives can be mentioned. Among these, those having 2 to 3 functional groups are preferred. The free isocyanate group content of the modified polyisocyanate and prepolymer is usually 10 to 33%, preferably
15-30%, particularly preferably 25-30%. In carrying out the method for producing polyurethane of the present invention, the above polymer polyol is reacted with an organic polyisocyanate, alone or in combination with other polymeric polyols or/and a crosslinking agent. . As the crosslinking agent that may be used in combination, low-molecular polyols and polyamines can be used. Examples of low-molecular polyols include triethanolamine, diethanolamine, ethylene glycol, diethylene glycol, butanediol, trimethylolpropane, and glycerin. Examples of polyamines include tolylene diamine, xylylene diamine, diaminodiphenylmethane, and methylenebis-O-chloroaniline. The amount of crosslinking agent used can be varied depending on the required degree of rigidity, etc. In the case of low-molecular polyols, it is usually 50% by weight or less, preferably 5 to 40% by weight of the total polyol.
% amount is used. When polyamines are used, they are used in smaller amounts, for example up to 10%, preferably from 2 to 5%, based on the total of polyol and amine. If the amount of the crosslinking agent is larger than the above, the urethane becomes too rigid and the temperature characteristics deteriorate. Other polymeric polyols that may be used include polyether polyols, polyester polyols, other polymer polyols, and the like. The polyether polyol may be of a commonly used type, and may be a compound having at least two active hydrogen atoms [polyhydric alcohols, amines, polyhydric phenols, polycarbonate, etc. mentioned as starting materials in (A) above]. [acids, etc.] and alkylene oxide (propylene oxide, ethylene oxide, butylene oxide, etc.) adducts. When used in combination with other polymer polyols, the polymer polyol accounts for usually 5% by weight or more, preferably 20% or more, more preferably 50% by weight or more of the total polymer polyol (total of the above polymer polyol and other polymer polyols). % or more is used. In producing polyurethane using the polymer polyol according to the present invention, the polyurethane foam may be produced by foaming, or the polyurethane resin (elastomer, sealant sheet, paint, adhesive) may be produced without foaming. May be manufactured. Foaming is usually carried out using a foaming agent, but foaming can also be carried out by introducing a gas such as air during molding. As the blowing agent, water and/or a halogen-substituted aliphatic hydrocarbon blowing agent (fluorocarbons such as trichloromonofluoromethane) can be used. The amount of blowing agent used can be varied depending on the required physical properties, usage, etc., but in general, in the case of water, it is usually 6 parts or less, preferably 4 parts per 100 parts of polyol.
below. In the case of fluorocarbons, the amount is usually 30 parts or less, preferably 15 parts or less. When manufacturing a polyurethane molded article by the RIM method (second invention), the amount of blowing agent is preferably 0.5 parts or less in the case of water, and 10 parts or less in the case of fluorocarbons, based on 100 parts of the polyol. Both blowing agents can also be used in combination. The ratio of polyisocyanate and active hydrogen atom-containing compound (polymer polyol, crosslinking agent, water) may be the same as that of ordinary polyurethane (resin, foam) (for example, 95 to 120 as an NCO index, especially 100).
~110). It is also possible to form a polyisocyanurate (resin, foam) by using an excess of isocyanate (for example, an index of 120 to 1000, especially 150 to 500. If necessary, a catalyst (tertiary amines, organic tin compounds, organic lead The reaction can be carried out in the presence of compounds (e.g. compounds), surfactants (e.g. silicone surfactants), and other auxiliaries. Pigments, fillers, flame retardants, solvents, thixotropic agents, etc. can be added as necessary. The polyurethane manufacturing method is the same as the conventional method, and either the one-shot method or the prepolymer method (semi-prepolymer method) can be applied.
The foam manufacturing method described in JP-A-55-133417, JP-A-46-5750, etc., JP-A-50-23497,
JP-A-49-99597 JP-A-53-42294 JP-A-53-
The elastomer, sheet or sealant manufacturing method described in No. 16796 and the like can be used, and the catalyst, surfactant and other auxiliary agents, equivalent ratio, amount added, etc., described in these can also be used. The polyurethane production method of the present invention is particularly useful for molding by the RIM method, but other methods such as molding other than the RIM method (open mold molding, integral molding with composite materials, cold cure and hot cure), slab law, on-site construction,
It can also be applied to various methods such as spraying, injection, coating, and impregnation. In the present invention (second invention), a method for producing a polyurethane molded product by molding by the RIM method can be carried out by a conventional method. For example, a polyol, a crosslinking agent, a catalyst, and if necessary a blowing agent (water and/or
or fluorocarbons), pigments, and foam stabilizers are added and mixed uniformly to form liquid A, and as liquid B, an organic isocyanate is prepared in advance and filled into the A and B liquid tanks of the high-pressure foaming machine. The injection nozzle of the high-pressure foaming machine is connected in advance to the injection port of the mold, and the mixing head mixes liquids A and B, injects the mixture into a closed mold, and removes the mixture after hardening. The polyurethane obtained by reacting the polymer polyol produced from the polyol composition consisting of (A) and (B) and an ethylenically unsaturated monomer with an organic polyisocyanate according to the present invention has low water absorption; Excellent strength properties (tensile strength, elongation) and weather resistance. Furthermore, since the polymer polyol used in the present invention has a low melting point and good fluidity, it has good workability and miscibility during the production of polyurethane, and can produce a uniform polyurethane. The method (second invention) of reacting the polymer polyol with an organic polyisocyanate and molding by the RIM method according to the present invention is superior to the conventional method in the following points. Because it has excellent curing properties, it is extremely effective in shortening the cycle time from injection to demolding, which is the original purpose of the RIM method. Even with a small amount of catalyst, the curing property is excellent, so the increase in viscosity when reacted with polyisocyanate is moderate, and it is possible to avoid insufficient filling and the formation of voids caused by poor flowability in the molded product. When manufacturing rigid polyurethane, it is possible to achieve the same rigidity with a smaller amount of crosslinking agent than conventional methods, and as a result, it has superior temperature characteristics compared to conventional methods (less changes in physical properties from low to high temperatures).
A polyurethane molded product is obtained. In the conventional RIM method, a large amount of catalyst is required to increase the curing property, and the physical properties of the molded product are greatly deteriorated due to the use of a large amount of catalyst, whereas the RIM method of the present invention has high curing property and requires a large amount of catalyst. Since the catalyst does not cause any deterioration in the physical properties of the molded product due to the catalyst. Furthermore, in addition to the RIM method, the method of the present invention can also be applied to
It exhibits excellent effects in various polyurethane manufacturing methods (foams, elastomers, sealants, coating agents, etc.), especially in polyurethane manufacturing methods that conventionally required relatively large amounts of catalysts and polyurethane manufacturing methods that use crosslinking agents. The polyurethane obtained by the present invention is useful for various uses, but it is particularly useful for molded products with a density of 0.7.
Suitable for high-density molded products with g/cm ³ or more. The present invention will be explained below with reference to Examples, but the present invention is not limited thereto. (The parts shown in the Examples represent parts by weight.) The polyols used in the following Examples and Comparative Examples were manufactured as in the following Production Examples 1 to 4 and Comparative Production Examples 1 and 2. Production example 1 Kolbene was mixed with a polyether polyol with a hydroxyl value of 42 (3466 parts of propylene oxide in 134 parts of trimethylolpropane, then ethylene oxide).
After adding 30 parts of polytetramethylene ether glycol (obtained by adding 400 parts of acrylonitrile) and 70 parts of polytetramethylene ether glycol with a hydroxyl value of 37 to 120 to 140°C with stirring, add azobisisobutyronitrile to 15 parts of acrylonitrile. A portion of the solution was added dropwise in small portions over 3 hours. After dropping, the mixture was aged at the same temperature for 1 hour to obtain the polymer polyol () of the present invention. Production example 2 Polyether polyol with a hydroxyl value of 28 (obtained by adding 4828 parts of propylene oxide and 1080 parts of ethylene oxide to 92 parts of glycerin) 80
20 parts of acrylonitrile and 20 parts of polytetramethylene ether glycol having a hydroxyl value of 56 were reacted in the same manner as in Production Example 1 using 20 parts of acrylonitrile and 1 part of azobisisobutyronitrile. A polymer polyol () according to the invention was obtained. Production Example 3 Acrylonitrile and styrene were added in advance in a weight ratio of 8:2 to a polyol composition prepared by mixing 50 parts of polyether polyol with a hydroxyl value of 28 obtained in Production Example 2 and 50 parts of polytetramethylene ether glycol with a hydroxyl value of 56. A reaction was carried out in the same manner as in Production Example 1 using 25 parts of the mixed monomers and 1 part of azobisisobutyronitrile to obtain the polymer polyol () of the present invention. Production example 4 Polyether polyol with a hydroxyl value of 22 (136 parts of pentaerythritol and propylene oxide)
70 parts of acrylonitrile and 1 part of azobisisobutyronitrile were added to a polyol composition prepared by mixing 70 parts of polytetramethylene ether glycol with a hydroxyl value of 112 and 70 parts of polytetramethylene ether glycol with a hydroxyl value of 112. The polymer polyol () of the present invention was obtained by reacting in the same manner as in Production Example 1. Comparative Production Example 1 A comparative polymer polyol was prepared by reacting 100 parts of polytetramethylene ether glycol with a hydroxyl value of 56 with 20 parts of acrylonitrile and 1 part of azobisisobutyronitrile in the same manner as in Production Example 1. I got (A). Comparative Production Example 2 In place of the polytetramethylene ether glycol in Comparative Production Example 1, the polyether polyol with a hydroxyl value of 28 used in Production Example 2 was used and reacted in the same manner to produce a comparative polymer polyol (B). I got it. The appearance and analytical values of polymer polyols ~ and A obtained in Production Examples 1 to 4 and Comparative Production Example 1 are as shown in Table 1.

[Molding prescription]

Polymer polyol 100 parts 1.4-butanediol 30 parts Black toner 4 parts Daiflon-11u 7 parts DABCO33LV 0.5 parts DTD 0.05 parts Millionate MTL NCO Index 105 (Note) Black toner: Carbon black dispersed in polyether polyol. Daiflon-11u: Freon manufactured by Daikin Industries, Ltd.
11. DABCO33LV: Amine catalyst manufactured by Sankyo Air Products. DTD: Dibutyltin dilaurate manufactured by Sankyoki Gosei Co., Ltd. Millionate MTL: Modified MDI manufactured by Nippon Polyurethane Co., Ltd. [Molding conditions for urethane molded product] A polyol component, which is a mixture of a polymer polyol, a crosslinking agent, and auxiliary agents such as a catalyst, and an isocyanate component are charged into the raw material tank of a high-pressure foaming machine, and A
After mixing liquid and B liquid with a high-pressure foaming machine, the thickness is 2.5mm and the width is 300mm.
A urethane molded product was created by injecting it into a temperature-controlled sealed mold with a length of 1000 mm. Discharge rate (Kg/min) Approx. 40 Discharge pressure (Kg/cm ² ) Approx. 160 Injection time (sec) Approx. 1.8 Raw material temperature (℃) Polyol component/Isocyanate component 50/40 Mold temperature (℃) 70±2 Mold release time (Seconds) 30 Example 5 and Comparative Example 2 Polyurethane molded products were produced using the polymer polyol or A under the same molding conditions as above and according to the following formulation. [Molding recipe] Polymer polyol 100 parts Ethylene glycol 20 parts Black toner 4 parts Freon-11 7 parts DTD 0.10 parts Millionate MTL NCO Index 105 Table 2 shows the physical property measurement results of the polyurethane molded products obtained in the above examples and comparative examples. Shown below. The physical properties were measured as follows. The molded polyurethane was immediately annealed at 120° C. for 1 hour after being released from the mold, and then left at room temperature for 3 days or more before measurement. Tensile strength: According to JIS K-6402. Elongation: Same as above Bending modulus: Sample size 25mm x 70mm
Measured with ×2.5mm (t), span 40mm, punch diameter 5R. Heat sag: Sample size 25mm x 150mm x
2.5mm (t) with 100mm overhang, left at 120℃ for 1 hour, then cooled at room temperature for 30 minutes, then measured the sagging distance. Brittle temperature: According to JIS K-6301. Water absorption: Sample size 100mm x 200mm x 2.5
mm (t), weight change rate after immersion in a water tank at 40°C for 10 days.

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Claims (1)

[Claims] 1. A method for producing polyurethane by reacting an organic polyisocyanate and a polyol, if necessary in the presence of a blowing agent, in which an ethylenically unsaturated monomer and (A) polyol are used as at least a part of the polyol. 1. A method for producing polyurethane, comprising using a polymer polyol produced from oxypropylene and/or polyoxyethylene polyol and (B) a polyol composition comprising polytetramethylene ether glycol. 2 The polyol composition contains (A) 20 to 95% by weight and (B)
The manufacturing method according to claim 1, which is a polyol composition comprising 5 to 80% by weight. 3. The manufacturing method according to claim 1 or 2, wherein (A) is a polyoxypropylene/polyoxyethylene polyol containing a terminal oxyethylene group. 4 The terminal oxyethylene group content of the polyoxypropylene/polyoxyethylene polyol is from 8 to
30% by weight of the manufacturing method according to claim 3. 5. The manufacturing method according to any one of claims 1 to 4, wherein the polyol composition has a hydroxyl value of 10 to 130. 6. A method for producing polyurethane by reacting an organic polyisocyanate and a polyol, if necessary in the presence of a blowing agent, in which an ethylenically unsaturated monomer and (A) polyoxypropylene and/or A high-density polyurethane characterized in that a polyurethane molded product is produced by a reaction-in-die extension molding method using a polymer polyol produced from a polyoxyethylene polyol and a polyol composition consisting of (B) polytetramethylene ether glycol. manufacturing method.