JPS6346766B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a novel polyurethane composition, and particularly to a hard polyurethane composition having 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 in various equipment parts and automobile parts, while highly foamed molded products are used mainly as insulation materials, making them a versatile resin that is useful for an extremely wide range of applications. has been done.

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 isocyanate groups obtained by trimerizing isocyanates;
At the same time, the resulting molded product becomes extremely brittle and cannot be put to practical use.

Also, as an engineering resin, P (load
The PV value, which is the product of Kg/cm ² ) and V (velocity m/min), is
It is said that a value of 800 or more is preferable for 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, and bending strength. and reduce impact resistance. In order to improve friction and abrasion resistance, we tried adding various silicone resins, fluorine oligomers, titanium coupling agents, silane coupling agents, encapsulated oil, etc., but none of them had foam-containing, impact resistance, It was found that properties such as tensile strength and bending strength deteriorated. 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 polyurethane with excellent friction and abrasion resistance, and in particular, to provide a new polyurethane that has a high heat distortion temperature of at least 100°C, which could not be achieved with conventional hard polyurethane, and has practical strength, especially impact resistance. An object of the present invention is to provide a rigid polyurethane composition.

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 hard, 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-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 product characterized by adding an aliphatic or aromatic oil component to the polyol component and/or polyisocyanate component;
It relates to a wear-resistant hard polyurethane composition.

The hard polyurethane of the present invention can be used in various fields, but 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. As another component, an adduct containing 3 moles or more of PO per mole of bisphenol A may be contained, usually at most about 60% by weight, preferably at most about 20% by weight. In addition, other components include bisphenol A and PO, which have one or two primary terminal hydroxyl groups.
The adduct of 2 or 3 moles or more 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 adducts of 1 mole of PO of bisphenol A, must be 1% by weight or less.

If the adduct containing 2 moles of PO to 1 mole of bisphenol A is less than 40% by weight, the concentration of the skeleton of bisphenol A as a polyol component decreases, resulting in a decrease in the heat resistance of the resulting polyurethane.

Furthermore, in the present invention, at least a bifunctional hydroxyl group with a hydroxyl value of 200 to 200 is added to the polyol as a polyol component.
700, preferably 300 to 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. 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. In view 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 polyoxyalkyl 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.

At least the above bifunctional hydroxyl value 200 to 700,
Preferably 300 to 500 aromatic amine-based polyoxyalkylene polyols are prepared by known methods such as aromatic monoamines such as aniline or 2,4- and 2,6-tolylene diamines (TDA) and so-called crude TDA, 4,4 '-diaminodiphenylmethane and one type of aromatic diamine and aromatic polyamine such as polymethylene polyphenylene polyamine obtained by condensation of aniline and formalin, ortho-, meta- or para-phenylene diamine, meta- or para-xylylene diamine, or Moreover, it is a polyol obtained by adding one or more alkylene oxides such as propylene oxide and ethylene oxide, and substantially no free primary or secondary amine 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 co-initiators. For example, polyfunctional aliphatic glycols such as ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, glycerin, trimethylolpropane, glucose, sorbitol, sucrose; aliphatic amines and aliphatic glycols such as ethanolamine, diethanolamine, triethanolamine, ethylenediamine; Examples include alkanolamines, and these co-initiators are preferably used in an equimolar or less amount relative to the aromatic amine.

The present invention uses a PO adduct of bisphenol A and an aromatic amine-based polyol as polyol components,
It is characterized by the fact that the polyurethane obtained by reaction with polyisocyanate has a high HDT.
In addition, although it has excellent processability and moldability, in addition to these polyol components, at least another difunctional polyol with a hydroxyl value of 50 to 1830 must be used 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, 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) Metaxylylene glycol, paraxylylene 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., and contains ethylene glycol, 1,4-butylene glycol, Aliphatic polyols such as methylolpropane, 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. These aromatic polyols in (a) are used in combination. 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, glucose, 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, the range is from 100 to 180, particularly preferably from 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. In order to lower the coefficient of friction, the isocyanate index is preferably 100 to 115.

In the present invention, an aliphatic or aromatic oil component is added to the polyol component and/or polyisocyanate component in order to improve the friction and abrasion resistance of the hard polyurethane obtained above. Aliphatic oils also include alicyclic oils. The above-mentioned aliphatic oil is preferably a lubricating oil specified by JIS, and specific examples thereof include turbine oil, gear oil, machine oil, 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.

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. By adding the oil component in this manner, the hard polyurethane of the present invention can be given superior friction and abrasion resistance to polyacetal resin, monomer cast nylon resin, and high-density polyethylene resin.

Although a catalyst is not particularly required for producing the rigid 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. It is also possible to obtain an inorganic filler-containing rigid polyurethane by preliminarily mixing the inorganic filler with polyol or polyisocyanate. 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 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 Industry Co., Ltd., "Bisol-2P" (approx. 93% of the 2-mole adduct of PO as determined by gas chromatography analysis,
Contains approximately 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.
%. It consists of 50 g of a TDA-based polyol with an OH value of 400 obtained by addition-reacting 50 g of this polyol with 1 mole of 2,4-tolylene diamine (TDA), 5.6 moles of propylene oxide, and 2.6 moles of ethylene oxide, 100 g of a mixed polyol, and carbodiimide modification. 98 g of 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 x
Pour into a 6mm prefabricated glass mold, 100
After reacting for 30 minutes in an air constant temperature bath at ℃, 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°C Flexural modulus 27600 Kg/cm ² Izot impact value 4.0 Kg cm/cm Friction coefficient μ=0.400 PV value 200 Example 1 100 g of the mixed polyol prepared in Reference Example 1 is prepared. On the other hand, carbodiimide-modified MDI (Japan Polyurethane Co., Ltd. “Millionate MTL”, NCO content
28.8%) 98g of Maruzen Sekiyu RO as aliphatic oil.
10g of 320 was added, heated to 80°C, and dehydrated under reduced pressure to bring the moisture content to 0.014%. A non-foamed, tough, rigid polyurethane was obtained in the same manner as in Reference Example 1 using both of them.

Heat deformation temperature 113℃ Flexural modulus 22100Kg/cm ² Izot impact value 2.4Kg・cm/cm Friction coefficient μ=0.09 PV value 1200 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℃ Flexural modulus 26000Kg/cm ² Izot impact value 2.5Kg・cm/cm Friction coefficient μ=0.090 PV value 800 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,
A 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%.
Ethylenediamine-based polyol with an OH value of 540 (average molecular weight 415) obtained by adding propylene oxide to 50g of this polyol and ethylenediamine.
To 100 g of a mixed polyol consisting of 50 g, 10 g of RO-320 manufactured by Maruzen Oil was added as an aliphatic oil, heated to 80° C., and dehydrated under reduced pressure to give a moisture content of 0.014%. Transfer this to a beaker and denature it with carbodiimide.
MDI (Millionate MTL, NCO content 28.8%)
117 g was added, 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 80℃ Flexural modulus 19260Kg/cm ^2Izotsu impact value 3.0Kg・cm/cm Friction coefficient μ=0.24 PV value 440

Claims (1)

[Claims] 1 A composition comprising a polyurethane obtained by the reaction of a polyol component having at least a difunctional hydroxyl group and an at least difunctional polyisocyanate component, the polyol component containing 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 product characterized by adding an aliphatic or aromatic oil component to the polyol component and/or polyisocyanate component;
Abrasion resistant hard polyurethane composition.