JPS6347727B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a novel polyurethane composition, and particularly to a polyurethane composition that has a high heat distortion temperature and excellent friction and abrasion resistance. Rigid polyurethane is broadly classified into non-foamed molded products and foamed molded products, and foamed molded products are further classified into high foamed molded products and low foamed molded products depending on the foaming rate. Non-foamed molded products and low-foamed molded products are used as engineering resins for various equipment parts, automobile parts, and the like. Conventional rigid polyurethanes contain one or more polyfunctional aliphatic or aromatic polyol monomers, polyoxyalkylene polyols, especially polyoxypropylene polyols, or polyfunctional aliphatic or aromatic polyester polyols. A polyol component consisting of a mixture, an aliphatic or aromatic polyisocyanate or a type of polyisocyanate,
or a polyisocyanate component consisting of a mixture thereof 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 heat distortion temperature of 80 to 100 at most. ℃ was the limit, and it was difficult to exceed 100℃ 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. Furthermore, it is said that it is preferable for the engineering resin to have a PV value, which is the product of P (load Kg/cm ² ) and V (velocity m/min), of 800 or more as a sliding member. However, the current rigid polyurethane made of polyol and polyisocyanate has a PV value of 400 or less, and has the disadvantage that it can only be used under conditions of low speed and low load. Generally, molybdenum disulfide and graphite are used to improve friction and wear resistance, but these compounds have no significant effect on hard polyurethane, but rather improve heat distortion temperature, tensile strength,
Decreases bending strength and impact resistance. Therefore, in order to improve friction and wear resistance, various silicone resins, fluorine oligomers, titanium coupling agents,
We tried adding silane coupling agents, encapsulated oil, etc., but it was found that all of them deteriorated in properties such as foam content, impact resistance, tensile strength, and bending strength. Furthermore, fiber reinforcement had only a negative effect. The object of the present invention is to have high thermal stability and
Our objective is to provide a polyurethane composition with excellent friction and abrasion resistance, and in particular, a polyurethane composition that has a high heat distortion temperature of at least 100°C, which was unattainable with conventional hard polyurethanes, and has practical strength, especially impact resistance. An object of the present invention is to provide a novel polyurethane composition having the following properties. Furthermore, the object of the present invention is to provide a friction-resistant material that can be used at low speeds and high loads, high speeds and low loads, and high speeds and high loads.
An object of the present invention is to provide a wear-resistant polyurethane composition. The present invention is a polyurethane composition obtained by the reaction of a polyol component having at least difunctional hydroxyl groups and an at least difunctional polyisocyanate component, wherein the polyol component includes 2,
A mixed polyol consisting of 40 to 80 parts by weight of a propylene oxide adduct of 2-bis(4-hydroxyphonyl)propane and 20 to 60 parts by weight of an aromatic amine-based polyoxyalkylene polyol having a hydroxyl value of 200 to 700 is used. , relates to a friction-resistant and wear-resistant polyurethane composition characterized in that an aliphatic or aromatic oil component and an inorganic compound powder having an ability to retain the oil component are added to the polyol component and/or the polyisocyanate component. The polyurethane of the present invention can be used in various fields, and is particularly useful as various industrial parts that require heat resistance, friction resistance, and wear resistance, such as sliding material parts 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). 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 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, in the present invention, the polyol has at least a difunctional hydroxyl value of 200 as a polyol component.
-700, preferably 300-500, is used in combination with an aromatic amine-based polyoxyalkylene polyol. Furthermore, the average hydroxyl value of the above mixed polyol component is
200 to 700, preferably 300 to 500, the impact strength of the polyurethane obtained was surprisingly contrary to expectations, and it was found that a synergistic effect of increasing impact strength was obtained without almost reducing the high HDT. Ivy. That is, the impact strength of the polyurethane using the above two types of polyol components in combination is superior to the impact strength of each polyurethane when the above two types of polyol components are used alone. Although the reason for this has not been fully elucidated in theory, it is considered 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. and,
The above effects of the present invention are surprising. In terms of moldability and physical properties, the polyol component consisting of the bisphenol A-PO adduct is preferably 40 to 80 parts by weight, and the aromatic amine-based polyoxyalkylene polyol is preferably 20 to 60 parts by weight. It has also been found that in the present invention, by using the PO adduct of bisphenol A in combination with an aromatic amine-based polyol, not only high HDT and impact strength can be obtained, but also processability, moldability, etc. can be effectively improved. Ivy. 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. Therefore, there is no need to add a catalyst to the polyol liquid.
One example is that the polyol liquid has excellent storage stability. 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 bifunctional 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 anhydride remains. 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 the polyol component is a PO adduct of bisphenol A and an aromatic mine-based polyol, and the polyurethane obtained by reaction with a polyisocyanate has a high HDT.
In addition, it has excellent processability and moldability, but this requires that at least another difunctional polyol with a hydroxyl value of 50 to 1830 be used in combination with the polyol component in an amount not exceeding 40% by weight based on the total polyol component. processability, such as reducing the viscosity of the polyol component,
It has the effect of improving moldability. 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, birogallol, 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) Meta-xylylene glycol, para-xylylene glycol (d) Phthalic acid, isophthalic acid Acid, aromatic dicarboxylic acid such as terephthalic acid, its anhydride or its lower alcohol ester, and/or aliphatic dicarboxylic acid such as adipic acid, succinic acid, etc. as the acid component, ethylene glycol, 1,4-butylene glycol, Aliphatic polyols such as trimethylolpropane, 1,4-cyclohexanediol, 1,
4-Cyclohexane dimethanol, β, β,
β',β'-tetramethyl-2,4,8,10-tetraoxaspiro(5,5)-undecane-
A polyester polyol with a hydroxyl value of 50 to 450 whose polyol component is an alicyclic polyol such as 3,9-diethanol or the polyols listed in (a), (b), and (c) above. Use of these aromatic polyols in (a) together. In this case, it is preferable that the amount does not exceed 50% by weight based on the total polyol, and that the average hydroxyl value is 200 to 500. (b) Polyfunctional aliphatic glycol with a hydroxyl value of 800 to 1830. Examples include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, and triethanolamine, which can be used in combination in an amount of 10% by weight or less based on the total polyol. (c) A polyfunctional aliphatic polyol with a hydroxyl value of 300 to 800. For example, a polyol in which one or more alkylene oxides such as propylene oxide and ethylene oxide are added to one or more of sucrose, sorbitol, glycose, pentaerythritol, trimethylolpropane, glycerin, ethylenediamine, diethanolamine, water, etc. , is preferably used in combination in an amount of 40% by weight or less based on the total polyol. The polyols listed above are particularly preferred, and other polyols with at least bifunctional hydroxyl value of 50 to 1830 are used based on all polyols.
They can be used in combination within a range not exceeding 40% by weight. Prior to the reaction with isocyanates, these polyols have a moisture content of 0.05% or less, preferably
It is necessary to keep it below 0.02%. Also, the polyisocyanates should be sufficiently degassed in advance. If these are neglected, 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 known as isocyanate index.
Preferably 100-180, particularly preferably 105-160
It is appropriate to carry out the treatment within the range of 1. Outside this range, the 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. In order to lower the coefficient of friction, the isocyanate index is preferably 100 to 115. In the present invention, in order to improve the friction and abrasion resistance of the polyurethane obtained above, an aliphatic or aromatic oil component and an inorganic compound powder having an oil component retention ability are added to the polyol component and/or polyisocyanate component. Added. Aliphatic oils also include alicyclic oils. The above-mentioned aliphatic oil is preferably a lubricating oil specified by JIS, and specifically includes turbine oil, gear oil, machine oil,
Examples include bearing oil, refrigerating machine oil, and lubricating oil for internal combustion engines. Further, as the aromatic oil, for example, petroleum-based softeners called extender oils or process oils are used, and various softeners such as paraffin-based process oils, naphthenic process oils, aromatic process oils, etc. can be used. Can be done. In the present invention, the above aliphatic oils or aromatic oils are used alone or as a mixture, and their ISOVG
[Viscosity grade, cSt (mm ² /s), 40℃] is 68 to 1000
is preferable, and 100 to 680 is particularly preferable. In this range, a migration phenomenon occurs in which the oil oozes onto the surface of the polyurethane, and this migration phenomenon produces a grease effect and improves the friction and wear resistance. However, the migration of oil components to the surface can have a negative effect on the appearance of the product and reduce its commercial value, so we conducted research to suppress the migration of oil components and found that a combination of aliphatic oil and aromatic oil was used as the oil component. It turned out to be preferable to do so. However, in this case, it was found that the HDT and PV values were lower than when aliphatic oil was added alone. To solve this problem, aliphatic oil and solid lubricants such as molybdenum disulfide, graphite, and carbon were mixed and then added to urethane resin, but even if the aliphatic oil and solid lubricant were in the same amount, Transfer to the urethane resin surface could not be prevented. Therefore, as a result of further intensive research, it has become possible to solve the above problems by using together an oil component and an inorganic compound powder having the ability to retain the oil component in the present invention. Examples of inorganic compounds used here include metal hydroxides such as calcium hydroxide, zinc hydroxide, and aluminum hydroxide, metal sulfates such as barium sulfate and sodium sulfate, metal sulfites such as sodium sulfite, sodium chloride, One or more metal halides such as potassium chloride can be used. If the particle size of the inorganic compound powder is large, it will not be sufficiently moistened by the oil component, and will be scattered in the polyurethane resin, causing local physical property deterioration and secondary heating, which will have an adverse effect on the resin surface. The following are preferred. In the present invention, the amount of the oil component added is preferably 1 to 15 parts by weight per 100 parts by weight of polyurethane.
Particularly preferred is 2 to 10 parts by weight. Within this range, friction resistance and abrasion resistance can be improved without reducing the tensile strength, bending strength, impact strength, etc. of the polyurethane obtained. In addition, in the present invention, the mixing ratio of the oil component and the inorganic compound powder is preferably 2 to 6/1 by weight, and more preferably 3/1.
A range of ~5/1 is more preferred. When kneading the oil component and the inorganic compound powder, it is preferable to knead equal amounts of both in a normal weight ratio using a ball mill or the like, and then dilute with a desired amount of the oil component before use. By adding the oil component and the inorganic compound powder in this manner, it is possible to impart friction and abrasion resistance superior to polyacetal resin, monomer cast nylon resin, and high-density polyethylene resin to the polyurethane of the present invention. 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. In order to further improve the physical properties, the inorganic filler can be mixed with the polyol or polyisocyanate in advance by using a combination of synthetic resin powder such as fluororesin or polyamide resin and metal soap. It is also possible to use polyurethane containing polyurethane. Examples of inorganic fillers include graphite, silicon carbide, aluminum oxide, and molybdenum disulfide, which are effective in improving hardness, molding shrinkage, friction coefficient, wear resistance, and the like. 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 the conventional polyurethane molded product 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% 2-mole adduct of PO as determined by gas chromatographic analysis,
Contains about 7% of the 3 molar adduct of PO. OH value 316)]
is heated to 100℃ and dehydrated under reduced pressure to reduce the moisture content to 0.015.
%. 100 g of a mixed polyol consisting of 50 g of a TDA-based polyol with an OH value of 400 obtained by addition reaction of 5.6 moles of propylene oxide and 2.6 moles of ethylene oxide to 1 mole of 2,4-tolylene diamine (TDA) and 50 g of this polyol, and carbodiimide. 98 g of modified MDI (Nippon Polyurethane Co., Ltd., "Millionate MTL" NCO content 28.8%) was stirred in a beaker for 40 seconds with a propeller type stirrer, and then defoamed in a vacuum desiccator for 1 minute. This mixture was immediately heated to 90℃.Inner dimensions: 130mm x 130mm
Pour into a 6mm assembled glass mold,
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 to obtain a non-foamed, tough polyurethane. 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 coefficient of friction was measured using a friction tester manufactured by Toyo Baldwin under dry conditions at 20 m/min and 50 kg/cm ² . Heat deformation temperature 118℃ Bending elastic modulus 27600Kg/cm ² Izot impact value 4.0Kg・cm/cm Friction coefficient μ=0.400 PV value 200 Reference example 2 Aliphatic oil ( 4 g of Maruzen Sekiyu RO-320) and 6 g of aromatic oil (Kyodo Sekiyu X-50F) were added, heated to 80°C, and dehydrated under reduced pressure to bring the moisture content to 0.015%. To this was added 100 g of the mixed polyol component of Reference Example 1, and in the same manner as in Reference Example 1, a non-foamed, tough, rigid polyurethane was obtained. Heat deformation temperature 108°C Flexural modulus 26000 Kg/cm ² Izot impact value 2.5 Kg cm/cm Friction coefficient μ=0.090 PV value 800 Examples 1 to 3 100 g of the mixed polyol prepared in Reference Example 1 is prepared. Place 2.5 g of BaSO ₄ in a mortar, add 2.5 g of Maruzen Oil's RO-320 as an aliphatic oil, and knead well to make three batches. Each of these
7.5 g of RO-320 (oil/BaSO ₄ = 4/1), 10 g (5/
1) and 12.5g (6/1) were added and kneaded again, and each of these was mixed with carbodiimide-modified MDI (Japan Polyurethane Co., Ltd. "Millionate MTL", NCO content 28.8
%) was added to a container containing 98 g, heated to 80°C and dehydrated under reduced pressure to bring the moisture content to 0.014%. A non-foamed hard polyurethane with a specular surface was obtained in the same manner as in Reference Example 1 using both of them. Results first
Shown in the table.

[Table] Comparative Example 1 Trimethylolpropane-based polyoxypropylene glycol “T-400” (Adeka, OH value
391) 100g (0.697 equivalent) and Sumidyur 44V-
104 g (0.768 equivalent) of 20 was reacted in the same manner as in Reference Example 1 (but without heat treatment) to obtain a non-foamed rigid polyurethane. Heat deformation temperature 76℃ Bending elastic modulus 23800Kg/cm ² Izot impact value 3.0Kg・cm/cm Friction coefficient μ=0.500 PV value 150 Comparative example 2 Using 100g of TDA base polyol used in Reference example 1 and Coronate MTL (109g) Then, a reaction was carried out in the same manner as in Reference Example 1 to obtain a non-foamed rigid polyurethane. Heat deformation temperature 102℃ Flexural modulus 25100Kg/cm ² Izot impact value 3.2Kg・cm/cm Friction coefficient μ=0.450 PV value 150 Comparative example 3 100g of TDA-based polyol used in Reference example 1,
The polyol component prepared by mixing 100 g of the polyol used in Comparative Example 1, 0.04 g of dibutyltin dilaurate, and 20 g of monochlorotrifluoromethane, and 220 g of Sumidyur 44V-20 were used in the same manner as in Reference Example 1 (but without heat treatment), and the specific gravity was determined. A rigid polyurethane foam of 0.50 was obtained. Heat distortion temperature (load 4.6Kg/cm ² ) 83℃ Bending modulus 6000Kg/cm ² Bending strength 184Kg/cm ² Izot impact value (without notch)
2.8Kg・cm/cm Friction coefficient μ=1.60 PV value 100 Comparative example 4 The propylene oxide adduct of bisphenol A (Bisol-2P) used in Reference Example 1 was heated to 100℃ and dehydrated under reduced pressure to remove moisture. The rate was set to 0.015%.
OH value 480 obtained by adding propylene oxide to 50g of this polyol and triethanolamine
Prepare 100 g of a mixed polyol consisting of 50 g of triethanolamine-based polyol (average molecular weight 350). Separately, take BaSO ₄ (25g) in a mortar, add 10g of Maruzen Oil's RO-320, mix well, then pour into 100g of the mixed polyol prepared earlier, heat to 100℃ and dehydrate under reduced pressure to bring the moisture content to 0.015%. did. Transfer this to a beaker and use carbodiimide modified MDI.
(Millionate MTL, NCO content 28.8%) 109g
was added and stirred in a beaker for 40 seconds with a propeller type stirrer, and then defoamed in a vacuum desiccator for 1 minute. Hereinafter, a rigid polyurethane was obtained in the same manner as in Reference Example 1, and its physical properties were measured in the same manner. Heat deformation temperature 88℃ Flexural modulus 18000Kg/cm ^2Izotsu impact value 1.05Kg・cm/cm Friction coefficient μ=0.23 PV value 640

Claims (1)

[Scope of Claims] 1. A composition comprising a polyurethane obtained by the reaction of a polyol component having at least difunctional hydroxyl groups and an at least difunctional polyisocyanate component, the polyol component comprising 2,
A mixed polyol consisting of 40 to 80 parts by weight of a propylene oxide adduct of 2-bis(4-hydroxyphenyl)propane and 20 to 60 parts by weight of an aromatic amine-based polyoxyalkylene polyol having a hydroxyl value of 200 to 700 is used. A friction-resistant and wear-resistant polyurethane composition, characterized in that an aliphatic or aromatic oil component and an inorganic compound powder having an ability to retain the oil component are added to the polyol component and/or the polyisocyanate component. 2 1 oil component per 100 parts by weight of polyurethane
The polyurethane composition according to claim 1, wherein the polyurethane composition is added in an amount of 15 parts by weight. 3 The ratio of oil component to inorganic compound powder is 2 by weight.
The polyurethane composition according to claim 2, which has a polyurethane composition of 6/1.