JPH0539339A - Polyurethane elastomer composition - Google Patents

Abstract

PURPOSE:To prepare a polyurethane elastomer compsn. excellent in heat resistance by curing a prepolymer prepd. by reacting p-phenylene diisocyanate and a specific hydroxyl-terminated polyol with 4,4'-methylenebis(o-chloroaniline). CONSTITUTION:A diol such as ethylene glycol is reacted with a carboxylic acid to give a hydroxyl-terminated polyester polyol of formula I or II having a number-average mol.wt. of 1,600-3,500. At least one of such polyester polyols or caprolactone polyols is reacted with p-phenylene diisocyanate in a nitrogen atmosphere to give a urethane prepolymer having a terminal isocyanate content of 1-20wt.%, which is mixed with a specified amt. of a curative [e.g. 4,4'- methylenebis(o-chloroaniline)], a plasticizer, a filler, etc., and thermally cured to give the objective compsn. excellent in resistance to oil and heat.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyurethane elastomer composition, and more particularly to a polyurethane elastomer composition which is more excellent in oil resistance and heat resistance than before.

[0002]

2. Description of the Related Art Recently, various properties such as excellent mechanical properties of a polyurethane elastomer composition have been actively utilized as a component of machine tools, OA equipment, FA equipment and the like. However, the required characteristics of these constituent members have recently become more sophisticated due to the dramatic improvement in performance of devices and the like due to recent rapid technological innovation. That is, the polyurethane elastomer composition is required to have higher oil resistance, heat resistance, etc. than ever before.

Polyurethane elastomer compositions are of the thermoplastic type, the cast type and the millable type. Of these, cast polyurethane elastomers, which have the best mechanical strength, are particularly widely used.
By the way, as a method for producing a polyurethane elastomer composition, a method in which a polyol is reacted with an excess of polyisocyanate to form a urethane prepolymer having an isocyanate group at a terminal, and then a curing agent is reacted therewith, a so-called pre-treatment Polymer methods are known. There are ether-based and ester-based polyurethane elastomers, and conventionally, ether-based polyurethane elastomer compositions have been produced by the prepolymer method with the following compositions.

First, 2,4-tolylene diisocyanate represented by adiprene (trademark of Uniroyal Chemical Co., Ltd., hereinafter) or a mixture of the 2,4-tolylene diisocyanate and 2,6-tolylene diisocyanate [=
4,4′-methylenebis (O-chloroaniline), which is a urethane prepolymer produced from TDI, hereinafter appropriately abbreviated as TDI] and polytetramethylene ether glycol [= PTMG, hereinafter simply abbreviated as PTMG]
[= MBOCA, hereinafter simply abbreviated as MBOCA],
2,6-dichloro-P-phenylenediamine, 1,2-
Some are cured with a curing agent for an aromatic diamine such as bis (2-aminophenylthio) ethane.

Since the polyurethane elastomer composition, which is so-called so-called adiprene type, produced in this manner has excellent mechanical properties, it has been conventionally used as various molded articles such as belts and rollers, and also as elastic sheets and the like. ing. However, when used in a machine tool or the like, it may be used in oil or in a place exposed to oil, but since the polyurethane elastomer composition obtained by the above composition uses a polyether polyol as a polyol component, swelling / heat deterioration does not occur. Intense.

Therefore, as a means for improving the heat resistance of this composition, paraphenylene diisocyanate [= PPDI, which may be considered to be able to obtain higher heat resistance depending on the molecular structure of polyisocyanate, will be simply abbreviated as PPDI hereinafter].
Whether or not it can be produced using PPDI was examined, and in view of the rapid reaction of PPDI, 1,4-butanediol [= 1,4-BG] and 1,4 bis (2-hydroxyethoxy) were used as its curing agent. It is known that diol compounds such as benzene [= BHEB] are effective [(Uret
hane chemistry and Application ACS Symposium Serie
s), 172, 419-431, 1981, University of Detroit].

However, when the above diol type curing agent is used for PPDI, the mold releasing time is long and there is a problem in productivity, and further heat resistance, oil resistance and other mechanical properties are not satisfactory. It was Furthermore, PPD
As a curing agent for I, it was sought to apply a diamine-based compound instead of the diol-based compound, and among these diamine-based compounds, 4,4′-methylenebis (dichloroaniline) [= TCDMA, hereinafter simply referred to as TCDA
The production method using M] is proposed (JP-A-63-270723). However, the above curing agent TC was added to PPDI.
When DAM is used, it is possible to obtain heat resistance that is to some extent satisfactory, but there is a problem in productivity due to the high melting point of TCCAM.

In order to eliminate the above-mentioned problems, it has been proposed that a polyurethane elastomer composition is obtained by using a curing agent MBOCA in a urethane prepolymer composed of PPDI and a specific ether-based polyol (Japanese Patent Application No. 2000-242242). Flat 3-21107). The proposed polyurethane elastomer composition has excellent heat resistance and can be precisely molded, and has a very excellent reaction property with a proper reaction time.

On the other hand, in spite of such excellent characteristics, the ether type polyurethane elastomer composition has a drawback that it is easily swelled in an oil environment due to its essential property, and it may be difficult to use for certain applications. That is, the ether-based polyurethane elastomer composition may have some problems in oil resistance. On the other hand, it can be generally said that the ester-based polyurethane elastomer has excellent oil resistance. This ester-based polyurethane elastomer composition has conventionally used TDI as a polyisocyanate and MBOCA as a curing agent. However, although this product is excellent in oil resistance, it has a problem in that it cannot satisfy the recently required performance in heat resistance.

Therefore, an attempt was made to use PPDI instead of TDI as the polyisocyanate.
Since this PPDI has a fast reaction as described above, it is very difficult to mold and cannot be cast.

[0011]

Therefore, an object of the present invention is to propose a polyurethane elastomer composition which is more excellent in oil resistance and heat resistance than before.

[0012]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in view of the above situation, the inventors have found that the above technical problems can be solved by adopting the following technical means to complete the present invention. Came to. That is, the polyurethane elastomer composition of the present invention comprises paraphenylene diisocyanate, a hydroxyl group-terminated polyester polyol, and 4,4′-methylenebis (O-chloroaniline) as main components, and the hydroxyl group-terminated polyester polyol is It contains at least one of a polyol having a group represented by the formula (Chemical formula 1) and a polyol having a group represented by the formula (Chemical formula 2), and the number average molecular weight of the polyol is It was determined to be 1,600 or more and 3,500 or less.

PPDI was selected as the isocyanate because the TDI represented by the conventional so-called adiprene type was used.
This is because it is considered that even higher heat resistance can be obtained than the polyurethane elastomer using As a curing agent, M
The use of BOCA is relatively cheaper than that of TCCAM, and its melting point is slightly lower (TCCAM has a melting point of 155 to 170 ° C, MBOCA has a melting point of 98 ° C or higher), is easy to handle, and has suitable workability. This is because it has the advantage that

The hydroxyl group-terminated polyester polyol contains at least one of a polyol having a group represented by the formula (Formula 1) and a polyol having a group represented by the formula (Formula 2). It was decided that these polyols had a low reactivity with the terminal diol, and the pot life (from adding the curing agent to the urethane prepolymer with fluidity until the viscosity increased and casting work became impossible) This is because the time can be set longer than when using a general-purpose polyester polyol.

The pot life is very important in the production process of polyurethane, and if the reaction in the curing step of the urethane prepolymer is too fast or too slow, there is a problem in terms of workability and productivity. That is, a pot life of about 2 to 20 minutes is suitable, and it is preferable that the pot life is as short as possible within an appropriate range. However, if it is too short, work such as mixing and casting becomes difficult and workability deteriorates,
On the other hand, if it becomes too long, productivity will deteriorate.

A hydroxyl group-terminated polyester polyol containing at least one of a polyol having a group represented by the formula (1) and a polyol having a group represented by the formula (2). The reason why the number average molecular weight is 1,600 or more and 3,500 or less is that when it is less than 1,600, the pot life is very short and molding is practically impossible, Three
When it is more than 500, the viscosity of the obtained prepolymer is high, so that the mixing is not sufficiently performed during the addition and stirring of the curing agent, and the physical properties are likely to vary, and the molecular weight of the polyol is large. This is because the content of the soft segment, which is a component, increases, but the content of the hard segment decreases, and therefore the crosslink density decreases, so that the mechanical properties cannot satisfy the required properties.

The polyol having a group represented by the formula (Chemical formula 1) and the polyol having a group represented by the formula (Chemical formula 2) may contain either one, of course. You may contain both. The polyurethane elastomer composition of the present invention contains the above composition as a main component, and even if other components are contained within a range not impairing the object of the present invention, they are included in the gist of the present invention. That is, the hydroxyl group-terminated polyester polyol is one or more selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, 1,4 butanediol, neopentyl glycol and 1,6 hexane glycol. A polyester polyol or a carboxylic acid or a caprolactone polyol may be contained. Other polyester polyols as described above may be contained.

Further, the polyurethane elastomer composition may contain additives and the like. Additives that can be used in the present invention are plasticizers, flame retardants, fillers, stabilizers, colorants and the like. Examples of the plasticizer include dioctyl phthalate (DOP), dibutyl phthalate (DBP),
Dioctyl adipate (DOA), tricresyl phosphate (TCP), chlorine-based paraffin, etc. can be used.

Examples of the flame retardant include phosphoric acid esters such as tris- (β-chloropropyl phosphate, tris-dichloropropyl phosphate and trischloroethyl phosphate, and bromine compounds such as dibromoneopentyl glycol and tribromoneopentyl alcohol. Fillers such as glass fiber, carbon black,
Calcium carbonate, talc, kaolin, zeolite, diatomaceous earth, perlite, permiculite, titanium dioxide, etc. can be used.

As the stabilizer, conventionally used antioxidants, ultraviolet absorbers, light stabilizers, hydrolysis inhibitors and the like can be used. Antioxidants are radical chain inhibitors
The former includes phenols and aromatic amines that act as peroxide decomposers and have steric hindrance. As a radical chain inhibitor, butylated hydroxytoluene, tetrakis [methylene ・ 3 ・ (3 '・ 5'-di ・ t-butyl-
4-hydroxyphenyl) propionate] methane, n.
Octadecyl-β- (4 '・ hydroxy-3'-5' ・
Di ・ t-butylphenyl) propionate, 1,3,5 tris (4 ・ t-butyl ・ 3hydroxy ・ 2,6-dimethylbenzyl) isocyanuric acid, triethylene glycol bis 3 (2-t-butyl ・ 4hydroxy-5 ・ methylphenyl)
Propionate or the like can be used.

As the peroxide decomposing agent, 4,4'thiobis (6-t-butyl.m.cresol, dilauryl.thiodipropionate, distearylthio.dipropionate, thiophenylphosphite and the like can be used. As a UV absorber, salicylic acid-based phenyl salicylate, Pt-butylphenyl salicylate, benzophenone-based 2,4-di-hydroxybenzophenone, 2-
Hydroxy-4-methoxybenzophenone, 2-hydroxy-4-n-octoxybenzophenone, benzotriazole-based 2 (2'-hydroxy-5'-methylphenyl) benzotriazole, 2 (2'-hydroxy-
3'-t-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2 (2'-hydroxy-3 ',
5'-di-t-aminophenyl) benzotriazole,
Siare acrylate type ethyl-2-cyano-3,5-
Diphenyl acrylate, 2 (2'-hydroxy-5 '
-T-octylphenyl) benzotriazole and the like can be used.

As the UV screen, pigments such as carbon black and zinc white can be used. As a light stabilizer, there is a hindered amine. Hindered amines include bis (1,2,2,2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalonate
6,6-pentamethyl-4-piperidyl, dimethyl-1- (2-hydroxyethyl) -4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate of succinate,
Poly [[6- (1,1,3,3-tetramethylbutyl)
Imino-1,3,5-triazine-2,4-diyl]
[(2,2,6,6-tetramethyl-4-piperidyl)
Imino] hexamethylene [[2,2,6,6-tetramethyl-4-piperidyl) imino]], 2- (3,5-di-t-butyl-4-hydroxybenzyl) -2-n-butylmalon Acid bis (1,2,2,6,6-pentamethyl-4-piperidyl) or the like can be used.

As a hydrolysis inhibitor, carbodiimide type stavaxol-1, PCD (Bayer Co.), hexamethylenetetraamine, azodicarbonamide, 4-t
-Butylcatechol and the like can be used. The method for producing the urethane prepolymer by reacting the hydroxyl group-terminated polyether polyol and paraphenylene diisocyanate is not particularly limited, and for example, a known reaction temperature, reaction time, presence or absence of a solvent, etc. are known. It can also be done by the method.

It is necessary to react the organic polyisocyanate and the active hydrogen-containing compound so that the prepolymer thus obtained has an isocyanate group content of 1 to 20% by weight. When the isocyanate group content of the obtained prepolymer exceeds 20% by weight and becomes large, the amount of free paraphenylene diisocyanate increases and the storage stability of the urethane prepolymer becomes poor.

On the other hand, if it is less than 1% by weight, the urethane prepolymer has a low isocyanate group content and the pot life becomes too long, resulting in poor productivity.

[0026]

EXAMPLES The polyurethane elastomer composition of the present invention will be described in more detail by way of examples. The following examples and the like were performed by the following procedure. A urethane prepolymer having a terminal isocyanate group by adding a polyisocyanate component (hereinafter referred to as (2)) to 100 parts by weight of a polyol component (hereinafter referred to as (1)) and reacting at 85 ° C. for 1 hour under a nitrogen stream. To get

Isocyanate group (NCO) content of the resulting urethane prepolymer (shown below), and
The viscosity at 80 ° C. (shown below) was measured. The viscosity of the prepolymer is a Haake rotary viscometer, Rotovisco RV.
It was determined using -12. 100 parts by weight of the urethane prepolymer obtained as described above was kept at 80 ° C., and a curing agent (hereinafter referred to as (3)) was melted at 120 ° C. and mixed,
The mixture was poured into a mold having a thickness of 2 mm which was previously kept at 110 ° C. and left in an oven at 110 ° C. for 10 hours to complete the curing reaction. The pot life (shown below) at this time was measured. By the above procedure, Examples and Comparative Examples were carried out using the components specifically shown below. (Example 1) (1) Polyol component 70 parts by weight of a polyester polyol (Kuraray Co., Ltd., trade name CLAPOL L-2010) having an average molecular weight (which refers to the number average molecular weight Mn. The same applies hereinafter) and an average molecular weight Of 2,015 polyester polyol (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 407
0) 30 parts by weight were blended and used.

In this specification, trade name CLAPOL L-***
What is shown as * and P-*** (in this example, Clapol L-2010) is shown by the following (Chemical formula 3) and (Chemical formula 4), respectively, and is 3-methyl-
It is a copolymer of 1,5-pentanediol and β-methyl-δ-valerolactone.

[0029]

[Chemical 3]

[0030]

[Chemical 4]

(2) Polyisocyanate Component Paraphenylene diisocyanate [= PPDI, manufactured by DuPont, the same applies hereinafter] was used in an amount of 15.5 parts by weight. (3) Hardener 4,4'-methylenebis (O-chloroaniline) [= M
10.3 parts by weight of BOCA, manufactured by Ihara Chemical Industry Co., Ltd., Ihara Cumian MT, the same shall apply hereinafter]. Each measurement result-isocyanate group (NCO) content ... 3.61% (theoretical value 3.52%). Viscosity at 80 ° C ... 4,410 cps. Pot life ... 2 minutes 30 seconds.

A sheet-shaped molding was obtained with the above composition. In this description, trade names Clapor L-*** and P- *
Since the polyester polyol shown as *** is liquid at room temperature, it has an advantage that the workability is much better than that of a general-purpose polyester polyol that is solid at room temperature. (Example 2) (1) Polyol component Polyester polyol having an average molecular weight of 2,059 (Kuraray Co., Ltd., trade name CLAPOL L-2010) 90
Part by weight and 10 parts by weight of a polyester polyol having an average molecular weight of 2,011 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 4040) were blended and used. (2) Polyisocyanate component PPDI was used in an amount of 15.9 parts by weight. (3) Hardener MBOCA was used in an amount of 9.9 parts by weight. Each measurement result-isocyanate group (NCO) content ... 3.45% (theoretical value 3.54%). Viscosity at 80 ° C .... 3,560 cps. Pot life ... 2 minutes 25 seconds.

A sheet-shaped molded product was obtained with the above composition. (Example 3) (1) Polyol component Polyester polyol having an average molecular weight of 2,022 (Kuraray Co., Ltd., trade name CLAPOL L-2010) 90
Parts by weight and 10 parts by weight of a polyester polyol having an average molecular weight of 1,986 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 4042) were blended and used. (2) Polyisocyanate component PPDI was used in an amount of 15.9 parts by weight. (3) 10.1 parts by weight of the curing agent MBOCA was used. Each measurement result-isocyanate group (NCO) content ... 3.52% (theoretical value: 3.59%). Viscosity at 80 ° C: 5,070 cps. Pot life ... 2 minutes 25 seconds.

A sheet-shaped molded product was obtained with the above composition. (Example 4) (1) Polyol component Polyester polyol having an average molecular weight of 2,022 (Kuraray Co., Ltd., trade name CLAPOL L-2010) 90
Part by weight and 10 parts by weight of a polyester polyol having an average molecular weight of 2,055 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 4010) were blended and used. (2) Polyisocyanate component PPDI was used in an amount of 15.8 parts by weight. (3) Hardener MBOCA was used in an amount of 9.9 parts by weight. Each measurement result-isocyanate group (NCO) content ... 3.47% (theoretical value: 3.58%). Viscosity at 80 ° C ... 4,770 cps. Pot life ... 2 minutes 05 seconds.

A sheet-shaped molded product was obtained with the above composition. (Example 5) (1) Polyol component Polyester polyol having an average molecular weight of 2,022 (Kuraray Co., Ltd., trade name CLAPOL L-2010) 10
0 parts by weight was used. (2) Polyisocyanate component PPDI was used in an amount of 15.8 parts by weight. (3) 10.8 parts by weight of the curing agent MBOCA was used. Each measurement result-isocyanate group (NCO) content ... 3.76% (theoretical value: 3.59%). Viscosity at 80 ° C ... 3,360 cps. Pot life ... 4 minutes 05 seconds.

A sheet-shaped molding was obtained with the above composition. (Example 6) (1) Polyol component Polyester polyol having an average molecular weight of 1,929 (Kuraray Co., Ltd., trade name CLAPOL L-2010) was used.
100 parts by weight was used. (2) Polyisocyanate component PPDI was used in an amount of 16.6 parts by weight. (3) 10.7 parts by weight of the curing agent MBOCA was used. Each measurement result-isocyanate group (NCO) content ... 3.75% (theoretical value 3.73%). Viscosity at 80 ° C .... 2,710 cps. Pot life ... 5 minutes 05 seconds.

A sheet-shaped molded product was obtained with the above composition. Next, a comparative example to the above embodiment will be described. (Comparative Example 1) (1) Polyol Component Polyester polyol having an average molecular weight of 1,042 (Kuraray Co., Ltd., trade name CLAPOL L-1010) was used.
100 parts by weight was used. (2) Polyisocyanate component PPDI was used in an amount of 30.7 parts by weight. (3) 17.4 parts by weight of the curing agent MBOCA was used. Each measurement result-isocyanate group (NCO) content ... 6.09% (theoretical value 6.17%). Viscosity at 80 ° C .... 1,610 cps. Pot life ... 1 minute 10 seconds.

As described above, the pot life was too short as 1 minute and 10 seconds to allow casting, and a sheet-shaped molded product could not be obtained. (Comparative Example 2) (1) Polyol component Polyester polyol having an average molecular weight of 1,509 (Kuraray Co., Ltd., trade name CLAPOL P-1510) was used.
100 parts by weight was used. (2) Polyisocyanate component PPDI was used in an amount of 21.2 parts by weight. (3) 13.6 parts by weight of curing agent MBOCA was used. Each measurement result-isocyanate group (NCO) content ... 4.76% (theoretical value: 4.59%). Viscosity at 80 ° C ... 2,210 cps. Pot life ... 1 minute 30 seconds.

As described above, the pot life was too short as 1 minute and 30 seconds to cast, and a sheet-shaped molded product could not be obtained. (Comparative Example 3) (1) Polyol component Polyester polyol having an average molecular weight of 3,728 (Kuraray Co., Ltd., trade name CLAPOL L-3010) was used.
100 parts by weight was used. (2) Polyisocyanate component PPDI was used in an amount of 8.6 parts by weight. (3) 5.5 parts by weight of the curing agent MBOCA was used. Each measurement result-isocyanate group (NCO) content ... 1.92% (theoretical value 2.08%). Viscosity at 80 ° C ... 11,290 cps. Pot life ... 10 minutes 25 seconds.

A sheet-shaped molded product was obtained with the above composition. (Comparative Example 4) (1) Polyol component Polyester polyol having an average molecular weight of 2,011 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 40
40) was used in 100 parts by weight. (2) Polyisocyanate component PPDI was used in an amount of 15.9 parts by weight. (3) 10.9 parts by weight of curing agent MBOCA was used. Each measurement result-isocyanate group (NCO) content ... 3.81% (theoretical value 3.60%). Viscosity at 80 ° C ... 11,180 cps. Pot life ... 0 minutes 50 seconds.

As described above, the pot life was too short as 0 minutes and 50 seconds, casting could not be performed, and a sheet-shaped molded product could not be obtained. (Comparative Example 5) (1) Polyol component Polyester polyol having an average molecular weight of 2,055 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 40
10) was used in 100 parts by weight. (2) Polyisocyanate component PPDI was used in an amount of 15.6 parts by weight. (3) Curing agent MBOCA was used in an amount of 10.5 parts by weight. Each measurement result-isocyanate group (NCO) content ... 3.67% (theoretical value 3.54%). Viscosity at 80 ° C .... 35,580 cps. Pot life ... 0 minutes 40 seconds.

As described above, the pot life was too short as 0 minutes and 40 seconds, casting could not be performed, and a sheet-shaped molded product could not be obtained. (Comparative Example 6) (1) Polyol component Polyester polyol having an average molecular weight of 1,986 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 40
42) was used in 100 parts by weight. (2) Polyisocyanate component 16.1 parts by weight of PPDI was used. (3) 9.8 parts by weight of curing agent MBOCA was used. Each measurement result-isocyanate group (NCO) content ... 3.43% (theoretical value 3.64%). Viscosity at 80 ° C ... 18,240 cps. Pot life ... 0 minutes 50 seconds.

As described above, the pot life was too short as 0 minutes and 50 seconds, casting could not be performed, and a sheet-shaped molded product could not be obtained. (Comparative Example 7) (1) Polyol component Polyester polyol having an average molecular weight of 2,051 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 40
73) was used in 100 parts by weight. (2) Polyisocyanate component PPDI was used in an amount of 15.6 parts by weight. (3) 10.1 parts by weight of the curing agent MBOCA was used. Each measurement result-isocyanate group (NCO) content ... 3.53% (theoretical value 3.54%). Viscosity at 80 ° C ... 62,620 cps. Pot life ... 1 minute 25 seconds.

As described above, the pot life was too short as 1 minute and 25 seconds to cast, and a sheet-shaped molded product could not be obtained. (Comparative Example 8) (1) Polyol component Polyester polyol having an average molecular weight of 2,015 (manufactured by Nippon Polyurethane Industry Co., Ltd., trade name Nipporan 40
70) was used in 100 parts by weight. (2) Polyisocyanate component PPDI was used in an amount of 15.9 parts by weight. (3) Curing agent MBOCA was used in an amount of 10.6 parts by weight. Each measurement result-isocyanate group (NCO) content ... 3.72% (theoretical value 3.60%). Viscosity at 80 ° C ... 12,280 cps. Pot life ... 1 minute 15 seconds.

As described above, the pot life was too short as 1 minute and 15 seconds to cast, and a sheet-shaped molded product could not be obtained. (Comparative Example 9) (1) Polyol component Polycaprolactone polyol having an average molecular weight of 1,996 (trade name: Praxel 2 manufactured by Daicel Chemical Industries, Ltd.)
20 N) was used in 100 parts by weight. (2) Polyisocyanate component 16.0 parts by weight of PPDI was used. (3) Hardener MBOCA was used in an amount of 9.9 parts by weight. Each measurement result-isocyanate group (NCO) content ... 3.45% (theoretical value: 3.63%). Viscosity at 80 ° C ... 2,320 cps. Pot life ... 0 minutes 50 seconds.

As described above, the pot life was too short, 0 minutes and 50 seconds, casting could not be performed, and a sheet-shaped molded product could not be obtained. (Comparative Example 10) (1) Polyol component Polytetramethylene glycol having an average molecular weight of 1,986 (trade name PTG200, manufactured by Hodogaya Chemical Co., Ltd.)
0) was used in 100 parts by weight. (2) Polyisocyanate component 16.1 parts by weight of PPDI was used. (3) Hardener 4,4'-methylenebis (dichloroaniline) [TCD
AM, manufactured by Ihara Chemical Industry Co., Ltd., trade name TCDA
M] was used in an amount of 9.8 parts by weight. Each measurement result-isocyanate group (NCO) content ... 3.44% (theoretical value: 3.64%). Viscosity at 80 ° C .... 2,500 cps. Pot life ... 14 minutes 30 seconds.

A sheet-shaped molded product was obtained with the above composition. The polyol component used in this comparative example is an ether type which is currently widely used. (Comparative Example 11) (1) Prepolymer Trade name Hyprene L-80 (manufactured by Mitsui Toatsu Co., Ltd.) was used. The polyisocyanate component is TDI and the polyol component is ether type. (2) 7.8 parts by weight of the curing agent MBOCA was used. Each measurement result-isocyanate group (NCO) content ... 2.73%. Viscosity at 80 ° C .... 2,570 cps. Pot life ... 15 minutes 36 seconds.

A sheet-shaped molded product was obtained with the above composition. The polyisocyanate component used in this comparative example is TDI which is currently widely used. The sheet-shaped moldings obtained in Examples 1 to 6 and Comparative Examples 3, 10 and 11 were punched with JIS No. 3 dumbbells to obtain samples for various tests described below. [Performance test] For each of the above samples, moldability, heat resistance (evaluated by heat aging resistance of hardness and mechanical properties),
Each evaluation test of oil resistance (hardness, mechanical characteristics, mass change rate, volume change rate, and oil aging resistance) was performed. Test method Moldability: Pot life was used as a scale for evaluating moldability. The test results in the examples are shown in Table 1, and the test results in the comparative examples are shown in Table 2. Heat resistance ... As a scale for evaluating the heat resistance, the retention rate of hardness and mechanical properties before and after the heat resistance test (the sample was left in a gear oven at 140 ° C. for 7 days) was used. Similarly, the test results in the examples are shown in Table 1, and the test results in the comparative examples are shown in Table 2. Oil resistance: As a scale for evaluating oil resistance, the retention rate of hardness and mechanical properties before and after the oil resistance test (the sample was left in JIS No. 3 oil at 70 ° C. for 3 days), and the mass change at that time The rate / volume change rate (how much it swells) was used.

The test results of the examples are shown in Table 3, the test results of the comparative examples are shown in Table 4, and the mass change rate / volume change rate test results are shown in Table 5.

[0050]

[Table 1]

[0051]

[Table 2]

[0052]

[Table 3]

[0053]

[Table 4]

[0054]

[Table 5]

In the table, PPDI is paraphenylene diisocyanate.
Anate and MBOCA are 4,4'-methylenebis (O
-Chloroaniline), PTMG is polytetramethylene
Ether glycol, TCDMA is 4,4'-methyle
Bis (dichloroaniline). Also the table mechanical
Among the characteristics, Hs is the hardness (JISA), M₁₀₀Is 100
% Modulus (Kgf / cm²), M₂₀₀Is 200% model
Thrust (Kgf / cm²), M ₃₀₀Is 300% modular
(Kgf / cm²), Tb is the tensile strength (Kgf / cm²)
, Eb shows elongation (%), and these physical properties are JIS-
It was measured according to K-6301.Moldability evaluation The pot lives of Examples 1 to 6 are 2 minutes and 30 seconds,
2 minutes 25 seconds, 2 minutes 25 seconds, 2 minutes 05 seconds, 4 minutes 05 seconds, 5
Minutes is 05 seconds, which is about 2 to 6 minutes.
It is possible range.

On the other hand, the pot lives of Comparative Examples 1 and 2 having a number average molecular weight of less than 1,600 were 1 min 10
The casting time is very short, 1 minute 30 seconds, and casting is practically impossible.
Similarly, the pot life of Comparative Example 3 having a number average molecular weight of more than 3,500 is 10 minutes and 25 seconds, which is within the range of moldability. The pot life of Comparative Examples 4 to 9 containing neither 3-methyl-1,5-pentanediol nor β-methyl-δ-valerolactone as a polyol component was 1 min 32 sec. 0
Minutes 50 seconds, 0 minutes 40 seconds, 0 minutes 50 seconds, 1 minute 25 seconds, 1 minute 15 seconds and 0 minutes 50 seconds were too short to cast.

The pot lives of Comparative Example 10 using a general-purpose polyether polyol and that of Comparative Example 11 using TDI as the polyisocyanate are 14 minutes 30 seconds and 15 minutes 36 seconds, respectively, which are within the moldable range. Is. Comparison of heat resistance evaluation Examples 1 to 6 and Comparative Examples 3, 10 and 11 with respect to retention rates of hardness and mechanical properties, the Examples are clearly superior. Oil resistance evaluation Examples 1 to 6 are compared with Comparative Examples 10 and 11 in terms of hardness / mechanical property retention rate and mass change rate / volume change rate. .. In particular, when the rate of change in mass and the rate of change in volume are taken out, it can be said that those of the examples are much less likely to swell than the comparative examples. Although the retention ratio and the like of Comparative Example 3 are excellent, the original mechanical properties are not good.

Since the polyurethane elastomer composition of the present invention has the above-mentioned excellent properties, for example, a toothed belt, a flat belt, a V-belt, which is a constituent member of automobiles, machine tools, OA equipment, FA equipment and the like, Suitable for various belts such as round belts, industrial rolls, rollers, slides, seals, etc., and more suitable for machine tools, automobile engine, room, etc. that are often exposed to oil environment. Can be applied.

[0059]

EFFECT OF THE INVENTION The present invention takes the above technical means, and by adopting the above respective constituents, provides a polyurethane elastomer composition which is more excellent in oil resistance and heat resistance than conventional ones. can do.

Claims (2)

[Claims] 1. Paraphenylene diisocyanate, a hydroxyl-terminated polyester polyol, and 4,4 ′.
-Methylenebis (O-chloroaniline) as a main component, and the hydroxyl group-terminated polyester polyol is a group represented by the following formula: And a group represented by the following formula: Containing at least one of the above-mentioned polyols and having a number average molecular weight of 1,6
A polyurethane elastomer composition, which is 00 or more and 3,500 or less. 2. The hydroxyl group-terminated polyester polyol is one selected from the group consisting of ethylene glycol, diethylene glycol, propylene glycol, 1,4 butanediol, neopentyl glycol and 1,6 hexane glycol, or The polyurethane elastomer composition according to claim 1, which contains a polyester polyol composed of two or more kinds and a carboxylic acid or a caprolactone polyol.