JPS646649B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel method for producing polyurethane resins, particularly hard polyurethane resins having high heat distortion temperatures. Among rigid polyurethanes, non-foamed molded products and low-foamed molded products are used as engineering resins in various equipment parts, automobile parts, and the like. Conventional rigid polyurethanes are composed of one or more polyfunctional resinous or aromatic polyol monomers, polyoxyalkylene polyols, especially polyoxypropylene polyols, or polyfunctional aliphatic or aromatic polyester polyols. A polyol component consisting of a mixture and a polyisocyanate component consisting of one or more aliphatic or aromatic polyisocyanates or polyisothiocyanates are cured and molded in the presence of a catalyst, a blowing agent, etc. However, these polyurethane molded products generally have poor heat resistance, and when heat distortion temperature (measured according to ASTM D-648) is used as a measure to evaluate heat resistance, conventional polyurethane molded products have a temperature of 80 to 80% at most. The limit was 100°C, and it was difficult to exceed 100°C with practical strength. On the other hand, heat resistance can be improved by introducing isocyanurate groups obtained by trimerization of isocyanate, but at the same time, the resulting molded product becomes extremely brittle and cannot be put into practical use. The object of the present invention is to provide a polyurethane with high thermal stability, in particular at least 100°C, which has not been achieved with conventional rigid polyurethanes.
The object of the present invention is to provide a novel polyurethane that has a high heat distortion temperature as described above and has practical strength, particularly impact resistance. The present invention comprises 80 to 98 parts by weight of a propylene oxide adduct of 2,2-bis(4-hydroxyphenyl)propane containing 2,2-bis{4-(2-hydroxypropoxy)phenyl}propane as one component; A polyol component having at least a difunctional hydroxyl group and an at least difunctional polyisocyanate component, which contains a mixed polyol consisting of 2 to 20 parts by weight of a polymer polyol obtained by graft polymerizing a monomer having a vinyl group to an ether polyol. The present invention relates to a method for producing a highly heat-resistant rigid polyurethane resin having a heat distortion temperature of 100°C or higher, which is characterized by reacting the following. The polyurethane of the present invention can be used in various fields, and is particularly useful as various industrial parts that require heat resistance, such as parts for sliding materials and other coatings. In the present invention, 2,2-bis(4-hydroxyphenyl)propane (2,2-bis{4-(2-hydroxypropoxy)phenyl}propane) having the following structure as one component of the polyol component is used in the present invention. (hereinafter referred to as bisphenol A)
By using a propylene oxide (hereinafter referred to as PO) adduct, we succeeded in obtaining a rigid polyurethane with excellent heat resistance. That is, in the present invention, since the PO adduct of bisphenol A was used as one component of the polyol component, the polyurethane obtained by reacting with polyisocyanate has a high concentration of aromatic rings in the molecular chain and has a rigid molecular structure, so it has a high glass content. Has a transition point. Therefore, it exhibits excellent thermal stability and a high heat distortion temperature (hereinafter referred to as HDT). When using the PO adduct of bisphenol A, the HDT is 10°C compared to when using the EO (ethylene oxide) adduct of bisphenol A instead.
Even more expensive. The bisphenol A-PO adduct of the present invention can be obtained by reacting 1 mole of bisphenol A with 2 or more moles of PO using a known method. That is, the above adduct is bisphenol A
2,2-bis{4-(2-
Hydroxypropoxy) phenyl}propane 1
Contained as an ingredient, its content is usually about 40% by weight
The content is preferably about 80% by weight or more. Other components include bisphenol A, an adduct containing 3 moles or more of PO per 1 mole, usually about 60%
It may contain up to % by weight, preferably up to about 20% by weight. In addition, bisphenol A having one or two primary terminal hydroxyl groups as other components.
The adduct of 2 moles or 3 moles or more of PO is produced as a by-product during the addition reaction, and can be contained in the polyol component in any proportion. However, the amount of unreacted phenolic hydroxyl groups, such as bisphenol A and PO, 1 molar adducts of bisphenol A, must be 1% by weight or less. In addition, if the adduct of 2 moles of PO per 1 mole of bisphenol A is less than 40% by weight, the concentration of the skeleton of bisphenol A, which is a polyol component, decreases, resulting in a decrease in the heat resistance of the resulting polyurethane. . Furthermore, although a rigid polyurethane composed of a PO adduct of bisphenol A and an isocyanate has high heat resistance, it has the drawback of being brittle and is therefore difficult to call practical. The present invention solves these drawbacks by using a polymer polyol in combination, and the tensile strength, flexural strength, flexural modulus, and impact strength are improved. Moreover, it has been found that the PV value, which is the product of P (pressure: Kg/cm ² ) and V (velocity: m/min), which are important for sliding members, is improved. In the present invention, the polymer polyol is a polyether polyol graft-polymerized with a monomer having a vinyl group, and preferably has a hydroxyl value in the range of about 56 to 200. As a specific example, a representative example of a commercially available product is Mitsui Nisso's
Examples include POP31/28, 32/30, 34/35, 36/28, 40/45, etc. The amount of polymer polyol added is preferably in the range of 2 to 20 parts by weight per 80 to 98 parts by weight of the PO adduct of bisphenol A. Additionally, polymer polyols can be added to polyol components and/or polyisocyanate components, but
When added to the PO adduct of bisphenol A, it is effective in reducing viscosity, and when added to the isocyanate component, it behaves like a prepolymer and improves physical properties. Furthermore, in the present invention, as a polyol component, 100 parts by weight of the above-mentioned mixed polyol is added with at least 10 parts of an aromatic amine-based polyoxyalkylene polyol having a difunctional hydroxyl value of 200 to 700, preferably 300 to 500.
When ~40 parts by weight is used together, the impact strength of the polyurethane obtained is surprisingly high, contrary to expectations.
This was accompanied by a synergistic effect of increasing impact strength with almost no decrease in HDT. In other words, the impact strength of the three types of polyol components above is higher than the impact strength of each polyurethane when the three types of polyol components are used alone.
Polyurethane containing various types of polyol components has excellent impact strength. The reason for this has not yet been fully elucidated, but considering that with conventional hard polyurethanes, impact strength tends to decrease when HDT is increased, and it is extremely difficult to increase both HDT and impact strength. , the above effects of the present invention are surprising. Furthermore, in the present invention, by using the PO adduct of bisphenol A, a polymer polyol, and an aromatic amine-based polyol in combination, not only high HDT and impact strength can be obtained, but also processability, moldability, etc. can be effectively improved. I also realized that. The improvement in processability referred to here refers to the reduction in the viscosity of the polyol liquid due to the introduction of the aromatic amine-based polyol, and the improvement in so-called compatibility in which the polyol liquid and the polyisocyanate liquid mix well even at room temperature. Further, since the chemical reaction proceeds due to the moderate autocatalytic action of the aromatic tertiary amine, no catalyst is intentionally required. Furthermore, even if the NCO Index is lowered, the reactivity is improved, which is also preferable for improving physical properties and lowering the coefficient of friction. Therefore, since there is no need to add a catalyst to the polyol liquid, the storage stability of the polyol liquid is excellent. Furthermore, improvement in moldability includes increasing the strength of the polyurethane molded product upon demolding due to the introduction of a primary network using at least a difunctional aromatic amine-based polyol. The above-mentioned at least bifunctional hydroxyl value 200~
Aromatic amine-based polyoxyalkylene polyols having a molecular weight of 700, preferably 300 to 500, can be prepared using known methods such as 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 and formalin, ortho- or meta- or para-phenylene diamines. , a free primary compound 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 meta- or para-xylylene diamine. Or it is a polyol in which substantially no secondary amine remains. This aromatic amine-based polyol is mixed with bisphenol A.
When used in combination with PO adducts and polymer polyols, the average hydroxyl value of the mixed polyol components should be
It is preferable to set it to 300-500. Further, the tertiary amine concentration of the mixed polyol used in combination is preferably 3 meq/g or less, particularly preferably in the range of 0.2 to 1.5 meq/g. Within these ranges, the above-mentioned synergistic effect due to combined use is particularly remarkable. The above-mentioned aromatic amine-based polyols are synthesized at the stage of synthesis to reduce viscosity and improve processability
In addition to aromatic amines, the following aliphatic glycols and the like can be used as coinitiators. For example, ethylene glycol, diethylene glycol,
Examples include polyfunctional aliphatic glycols such as propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, glucose, sorbitol, and sucrose; aliphatic amines and aliphatic alkanolamines such as ethanolamine, diethanolamine, triethanolamine, and ethylenediamine. These co-initiators are preferably used in an equimolar or less amount relative to the aromatic amine. The present invention is characterized in that a mixed polyol consisting of the PO adduct of bisphenol A and a polymer polyol is used as a polyol component. Other at least difunctional polyols having a hydroxyl value of 50 to 1830 may be used in combination with the component. In this case, it is preferable to use 55 to 97 parts by weight of a PO adduct of bisphenol A, 2 to 15 parts by weight of a polymer polyol, and 1 to 30 parts by weight of a polyol having a hydroxyl value of 50 to 1,830. Specific examples of the at least difunctional polyol having a hydroxyl value of 50 to 1830 include the following polyols. (a) An aromatic polyol having a hydroxyl value of 50 to 850 and having at least difunctional hydroxyl groups. (a) Hydroquinone, pyrogallol, 4,4'-
Polyol with a hydroxyl value of 250 to 600 obtained by adding an alkylene oxide such as propylene oxide or ethylene oxide to a monocyclic or polycyclic aromatic compound having at least two hydroxyl groups such as isopropylidene diphenol (b) Phthalic acid, isophthalic acid acid, terephthalic acid,
Polyols with a hydroxyl value of 300 to 500 obtained by adding alkylene oxides such as propylene oxide and ethylene oxide to aromatic polybasic acids such as trimellitic acid (c) Metaxylene glycol, baraxylylene glycol (d) Phthalic acid, isophthalic acid, The acid component is aromatic dicarboxylic acid such as terephthalic acid or its anhydride or its lower alcohol ester, and/or aliphatic dicarboxylic acid such as adipic acid or succinic acid, and ethylene glycol, 1,4-butylene glycol, or trimethylol. Aliphatic polyols such as propane, 1,4-cyclohexanediol, 1,
4-Cyclohexane dimethanol, β, β,
β',β'-tetramethyl-2,4,8,10-tetraoxaspiro(5,5)-undecane-
Polyester polyol with a hydroxyl value of 50 to 450, whose polyol component is an alicyclic polyol such as 3,9-diethanol or the polyol of (a), (b), or (c) above (b) Polyfunctional polyester with a hydroxyl value of 800 to 1830 Aliphatic glycols. For example, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, triethanolamine, etc. (c) Polyfunctional aliphatic polyol with a hydroxyl value of 300 to 800 For example, one or more of sucrose, sorbitol, glycol, pentaerythritol, trimethylolpropane, glycerin, ethylenediamine, diethanolamine, water, etc., and propylene oxide, ethylene oxide, etc. A polyol to which one or more alkylene oxides are added. The polyols exemplified above are particularly preferred, and other at least difunctional polyols having a hydroxyl value of 50 to 1830 can also be used. On the other hand, since the PO adduct of bisphenol A has a high viscosity, it is not necessarily compatible with the above-mentioned polyol having a hydroxyl value of 50 to 1830, which may result in poor appearance and nonuniform quality. In order to eliminate this drawback, it is preferable to use the above-mentioned aromatic amine-based polyoxyalkylene polyol having the same aromatic group as the PO adduct of bisphenol A. In this case, the PO adduct 55-97 of the above bisphenol A
It is preferable to blend 10 to 40 parts by weight of an aromatic amine base polyol to 100 parts by weight of a mixed polyol consisting of 2 to 15 parts by weight of a polymer polyol and 1 to 30 parts by weight of a polyol having a hydroxyl value of 50 to 1830. . In the present invention, the polyol must have a moisture content of 0.05% or less, preferably 0.02% or less prior to the reaction with the isocyanate. Also, the polyisocyanates should be sufficiently degassed in advance. If this is not done, unnecessary foaming will occur during the curing reaction. However, this is of course not the case when obtaining a foam. As the polyisocyanate component of the present invention, various at least difunctional aliphatic, alicyclic, and aromatic polyisocyanates known in the field of polyurethane production can be used, but aromatic polyisocyanates are particularly preferably used. . For example, 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), 2,4- and 2,6-tolylene diisocyanate (TDI), orthotoluidine diisocyanate (TODI), naphthylene diisocyanate (NDI), xylylene diisocyanate (XDI), and the like are preferably used. The polyol component and the polyisocyanate component can be reacted by a one-shot method or a prepolymer method. The reaction between polyol and polyisocyanate is preferably performed as an isocyanate index (NCOIndex) of 100 to 180,
Particularly preferably, it is within the range of 105 to 160; outside this range, heat resistance decreases regardless of whether the isocyanate index becomes smaller or larger. Although the cause of this is not clear, it is presumed that it is due to a decrease in the substantial molecular weight of the polymer. Although a catalyst is not particularly required for producing the polyurethane of the present invention, known catalysts such as tertiary amines such as triethylene diamine and organometallic compounds such as dibutyltin dilaurate can also be used. However, isocyanate trimerization catalysts that produce isocyanurate rings are not preferred. Incidentally, it is also possible to obtain an inorganic filler-containing polyurethane by mixing the inorganic filler with the polyol or polyisocyanate in advance. Inorganic fillers include glass fibers such as milled glass fibers and chopped strand glass fibers, graphite, silicon carbide, aluminum oxide, molybdenum disulfide, etc., and have properties such as hardness, molding shrinkage rate, coefficient of friction, and wear resistance. However, it is desirable to add a minimum amount of filler, and adding too much will lead to deterioration of physical properties. In addition, when friction resistance and wear resistance are required,
By adding lubricating oil, it can be dramatically improved. In this case, the lubricating oil is preferably added in an amount of 1 to 20 parts by weight per 100 parts by weight of the urethane resin. In the present invention, it is also possible to form a foam by using water, a halogenated hydrocarbon such as trifluorotrichloroethane, or an organic blowing agent such as azobisisobutyronitrile. In the present invention, the curing reaction can be carried out, for example, as follows. First, adjust the liquid temperature of the compound to room temperature to 120℃.
℃, and the temperature of the casting mold is set to 50 to 120℃, and the mold is poured, hardened, and demolded. The cured molded product of the present invention is higher than conventional polyurethane molded products even as it is.
Although it has HDT, properties such as impact strength can be improved by further performing heat treatment at a temperature of 140 to 180°C. The heat treatment can be performed in an inert gas atmosphere such as air or nitrogen. The present invention will be explained below with reference to reference examples and examples. Reference example 1 Propylene oxide adduct of bisphenol A [manufactured by Toho Chiba Chemical Co., Ltd., "BISOL-2P" (approx. 93% of 2 mole adduct of PO as determined by gas chromatographic analysis,
Contains approximately 7% of the 3 molar adduct of PO. OH value 316)]
100g of polyol obtained by heating 1000g to 100°C and dehydrating under reduced pressure to a moisture content of 0.015%, and 1100g of carbodiimide-modified MDI (Japan Polyurethane Co., Ltd., "Millionate") obtained by vacuum dehydration by the above method.
MTL', NCO content 28.8%) 88g in a beaker
The mixture was stirred with a propeller type stirrer for 40 seconds and then defoamed in a vacuum desiccator for 1 minute. This mixed solution was immediately poured into a prefabricated glass mold with inner dimensions of 130 mm x 130 mm x 6 mm heated to 90°C, and after reacting for 30 minutes in an air constant temperature bath at 100°C, the cured product was taken out from the mold. During this time, no bubbles were observed.
Next, heat treatment was performed for 2 hours in an air constant temperature bath at 160°C. A non-foamed, slightly brittle hard polyurethane was obtained. The heat distortion temperature of the obtained polyurethane is determined by ASTM,
The flexural modulus is determined by D648 under a load of 18.6 kg/cm ² by ASTM, the Izot impact value by D790 is determined by ASTM, and the notched condition is determined by D256.
The friction coefficient was measured using a friction tester manufactured by Toyo Baldwin Co., Ltd. under dry conditions at 20 m/min and 5 to 60 kg/cm ² . Table 1 shows the physical properties. Examples 1 to 4 Polymer polyol [manufactured by Mitsui Nisso, “POP40/
45", hydroxyl value 110] was taken, heated to 100°C, and dehydrated in vacuum. Also, 5.6% of propylene oxide per mole of 2,4-tolylene diamine (TDA)
150 g of TDA-based polyol (GR-30, manufactured by Takeda Pharmaceutical Co., Ltd.) with an OH value of 400 obtained by addition reaction with 2.6 moles of ethylene oxide was heated to 100°C and dehydrated under reduced pressure to obtain a moisture content of 0.015%. I made it. According to the formulation in Table 1, a predetermined amount of BISOL-2P prepared in Reference Example 1, the polymer polyol prepared in the above method, and GR-30 are added to a beaker to obtain a mixed polyol, and then added to the mixed polyol prepared in Reference Example 1. did
A rigid polyurethane was obtained in the same manner as in Reference Example 1 by adding MTL. Table 1 shows the physical properties. Examples 5 to 10 Diol with a molecular weight of 200 [manufactured by Sanyo Chemical Co., Ltd., “PP-
200'', hydroxyl value 560] was heated to 100°C and dehydrated in vacuum. In addition, 100g of sucrose-based polyol [manufactured by Mitsui Nisso, "LV450A", hydroxyl value 450] was heated to 100℃.
and vacuum dehydrated. BISOL-2P prepared in Reference Example 1 and the polymer polyol prepared in Examples 1 to 4 were placed in a beaker.
Add GR-30 and the above PP-200 and LV450A in the specified amounts shown in Table 2 to make a mixed polyol.
A rigid polyurethane was obtained in the same manner as in Reference Example 1 by adding MTL prepared in Reference Example 1. Table 2 shows the physical properties.

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Claims (1)

[Claims] 1 2,2-bis{4-(2-hydroxypropoxy)phenyl}propane as one component
-Polymer polyol 2 obtained by graft polymerizing 80 to 98 parts by weight of a propylene oxide adduct of bis(4-hydroxyphenyl)propane and a monomer having a vinyl group to a polyether polyol
containing a mixed polyol consisting of ~20 parts by weight,
The heat distortion temperature is characterized by reacting a polyol component having at least a difunctional hydroxyl group with an at least difunctional polyisocyanate component.
A method for manufacturing hard polyurethane resin with high heat resistance of 100℃ or higher.