NO152783B - BISAMINOPYRIDINES USED AS COUPLING AND / OR DEVELOPING COMPONENTS FOR OXIDATION COLORS - Google Patents

Description

Process for the production of non-cellular urethane elastomers.

The present invention relates to hitherto unknown urethane elastomers. More particularly, the invention relates to urethane polymers derived from organic polyisocyanates, polyalkylene ether polyols and low molecular weight alkylene diols. The invention

includes a new "one-step" method for

their production.

Urethane elastomers are a well-known

class of materials that have different

applications. They can be molded or shaped

complicated shapes and shaped to give such

various items such as fixed rings, anti-vibration mounts, impellers, propellers,

liners, bearings, pipe liners, exchanges,

belts, protective equipment, iron lung valves,

helmet liners and oxygen masks. The general method of manufacture includes it

preliminary formation of a prepolymer by

to co-react a polyfunctional diol, e.g.

a polyester or a polyether glycol, with a

excess of polyisocyanate. The resulting prepolymer containing unique isocyanate groups, as well as free polyisocyanate, is then cured by reaction

with a polyfunctional compound which

contains hydrogen, e.g. water, an aromatic or aliphatic diamine, or an aliphatic diol.

The elimination of the expensive and often not

appropriate prepolymer steps often result in low quality products that

has deficiencies with respect to such properties as tensile strength, elongation, modulus, compressibility, etc. Moreover, the use

of isocyanate-terminated prepolymers requires subsequent reaction with chain-extending agents at relatively high temperatures, e.g. 100° C or more, which conditions lead to a correspondingly short "lifetime" which results in processing difficulties during the casting or forming treatment, or other disadvantages, such as limitation of the batch size.

Many compositions have included an aryl diamine such as 4,4'-methylene-bis-(2-chloroaniline) as a chain extender for the middle part. This agent gives elastomers with high tensile strength, but it is relatively expensive and, moreover, other properties of the elastomer are usually poor, e.g. the extension is reduced.

It is therefore an object of the present invention to provide an efficient and economical "one-step" process for the production of urethane elastomers. This "one-step" process relates to a method in which all components are converted simultaneously, but not necessarily completely.

According to the present invention, a method for the production of non-cellular urethane elastomers has been provided which consists in simultaneously reacting a polyisocyanate, a polyalkylene ether glycol having a molecular weight of 500-2500, preferably 700-1300, and a lower hydrocarbon alkylenediol, preferably 1,4- butanediol, in the presence of a catalyst, and these components are reacted in the following conditions:

and optionally in the presence of a difunctional chain-extending agent, preferably an aryl diamine in an amount of less than that which would give 0.20 of a functional group for each hydroxyl group present, preferably less than that which would give 0.10 of a functional group for each hydroxyl group present.

Apart from arylene diamines, other suitable chain extenders are water, maleic acid (anhydride) or aliphatic diamines. The resulting elastomer is characterized after curing in the usual way by a surprisingly high tensile strength and satisfactory, if not outstanding, other physical properties.

A number of varieties of organic polyisocyanates or mixtures thereof can be used, but diisocyanates and especially liquid diisocyanates are preferred. Examples of suitable isocyanates are: m-phenyl diisocyanate 2,4-tolylene diisocyanate 2,6-tolylene diisocyanate naphthalene-1,5-diisocyanate cumene-2,4-diisocyanate 4,4', methylene-bis-(phenylisocyanate) 4,4', methylene-bis-(cyclohexyl- isocyanate)

4,4',4"-triphenylmethane triisocyanate 1,6-hexamethylene diisocyanate 1,3,5-benzene triisocyanate, and

polyalkylene polyaryl polyisocyanates,

such as those described in U.S. patent no. 2 683 730. The commercially available mixture of diisocyanates consisting of 80% 2,4- and 20% 2,6-tolylene diisocyanates and 4,4'-methylene-bis-(phenylisocyanate) is particularly preferred.

The amount of the isocyanate used is such that it provides 0.95 to 1.20 isocyanate groups for each active hydrogen-containing group, i.e. hydroxyl and amino groups, present in the reaction mixture. Preferably, an excess of -NCO groups is present, and this excess is from approx. 0.05 to 0.20 -NCO group for each active hydrogen-containing group.

The polyalkylene ether glycol reaction component used in the method according to the present invention is assumed to have the general formula:

R

IN

HO(CH2-CHO)xH

where R is hydrogen or a lower alkyl group with 1-5 carbon atoms and x is an index of such size that the molecular weight of the glycol is within the range approx. 500-2500, preferably within the area of approx. 700—1300, and especially approx. 1000. Typical glycols suitable for use as this reaction component include: polyethylene ether glycol polypropylene ether glycol polybutylene ether glycol polyamylene ether glycol

Mixtures of these and equivalent glycols may be used if desired.

The polyether glycols can be obtained by condensation of an alkylene oxide, or mixture of alkylene oxides, such as ethylene glycol, in the presence of a suitable catalyst, e.g. trimethylamine or potassium hydroxide. The preparation of such polyalkylene ether glycols is well known in the art.

The lower hydrocarbon alkylene glycols that can be used have a molecular weight of at least 62 to about 200 and includes the following typical examples: ethylene glycol propylene glycol 1.3-butanediol 1.4-butanediol 1.5-pentanediol 1,3-hexanediol 1,8-octanediol

Mixtures of these and equivalent diols can be used. If desired, triols that have a molecular weight of over 100 up to approx. 2000, such as polypropylene ethertriol, is used in amounts up to approx. 30 equivalent percent based on the amount of polyalkylene ether glycol used. This triol auxiliary leads to hard, relatively compliant elastomers that have a strong degree of cross-linking.

In the production of urethane elastomers according to the present invention, the reaction components can be used in varying amounts within the stated limits, depending on the particular range of properties desired in the final elastomer product. Thus, the highly flexible method can be used to produce urethane elastomers in the form of soft elastic materials for very hard elastoplastic products, i.e. products that show good elongation but low compliance.

The characteristic properties of the elastomers are believed to result in part from the use of relatively large amounts of the lower hydrocarbon alkylene diol. This diol component is believed to perform at least two important functions in the invention;

(1) The reaction with isocyanate compo-

is stronger and consequently more exothermic than the corresponding reaction of the polyalkylene ether glycol and the isocyanate. Thus, the exothermic peak is increased to a desired extent and normal heating of the polymerization mixture is not necessary to the same extent, i.e. the reaction can be carried out at lower temperatures.

(2) The linear reaction product of the diol and the isocyanate which can be represented by

has a linear molecular structure that "fits" into the polymer structure.

With respect to the first function, it will be understood that as the molecular weight of the diol increases, the increased exothermic effect will decrease, and consequently less low molecular weight diol, such as ethylene glycol, will be necessary to achieve the effect that would be achieved with a diol of higher molecular weight, such as 1,6-hexanediol. Consequently, when the ranges for the diol reaction component used are to be given, it should be understood that the lower limit of the range finds adaptation to the diol of lower molecular weight and consequently the upper limit refers to the higher diols.

With reference to the second function stated above, it is stated that as the molecular weight increases, the softness of the polymer increases and conversely, as the molecular weight of the diol decreases, the polymer becomes harder.

The preferred diol is 1,4-butanediol and the preferred amount used is within the range of 1.8 to 3 mol of butane-diol per moles of polyalkylene ether glycol.

The so-called "chain-extending" components, i.e. water, maleic acid and preferably arylene or aliphatic diamines which can, if desired, be used in the present invention are well known in the field. Typical of these preferred compounds are: 4,4'-methylene-bis-(2-chloroaniline) 4,4'-methylene-bis-2 (bromoaniline) 4,4'-methylene-bis (2-methoxyaniline) 4,4 '-methylene-bis-(2-ethylaniline) 4,4'-methylene-bis-(2-hexylaniline') 2,2'-dichloro-benzide and 1,6-hexylenediamine.

Condensation products of polymerized unsaturated fatty acids with aliphatic diamines, such as "Versamides" and mixtures of these diamines with each other and equivalent "chain extenders" can also be used.

The chain-extending substance is used to obtain products with increased tensile strength. However, this method of increasing strength can be carried out at the expense of the elastic properties of the polymer. Accordingly, this component is added in relatively small quantities. The amount of the arylenediamine used in this connection is given by the expression:

<*>) or other functional group derived from the "chain extender".

The preferred diamine is 4,4'-methylene-bis-(2-chloro-aniline) because of its low reactivity, low melting point and easy availability, and the compound sel-

is given commercially under the trade name

"MOCA".

Examples of suitable catalysts or activators or accelerators for use in the method are: (1) Tertiary amines such as triethylamine, N-ethylmorpholine, triethylenediamine and N,N,N',N'-tetramethyl-1,3-butanediamine. (2) Tertiary amines containing hydroxy groups and capable of cross-linking with the urethane segments, such as: where X,, X,„ X,j and X4 can be the same or different and are H-CO-alkylene), in which z is an index from 1-4, and the alkylene stands for a divalent aliphatic saturated hydrocarbon with from 1- 10 carbon atoms, i.e. one of the X's can be an alkyl radical with up to 20 carbon atoms, n is an index from 1—10, preferably 2 or 3, m is an index from 0 to 3, and y is an index from 1— 10. Typical catalysts are: tetra-(hydroxyethyl) ethylenediamine tetra-(hydroxypropyl) ethylenediamine the condensation product of propylene -

oxide

and di(ethylenediamine) N-cocos-iV,iV',JV'-trihydroxyethyl-ethylenediamine.

(3) Organotin compounds of the general formula: where -CH2X means a hydrocarbon radical with 1-18 carbon atoms, R,, R;, and R., is a hydrocarbon radical with 1-18 carbon atoms, hydrogen, halogen or a hydrocarbon acyl radical, and R,, R., and R. , are the same or different and a further two of the groups R,, R„ and R., can together be oxygen or sulphur. Typical catalysts of this class are: tetramethyltin tetra-n-butyltin tetraoctyltin dimethyldioctyltin dilauryltin difluoride di-n-butyltin dichloride 2-ethylhexyltin triiodide di-n-octyltin oxide di-n-butyltin dilaurate di-t-butyltinndiacetate di-n-butyltin-bis- (monobutyl- maleate) di-2-ethylhexyltin-bis-(2-ethyl- hexanoate) tri-n-butyltin acetonate and di-butyltin distearate. (4) Organic tin salts, such as stannous octoate and stannous oleate.

The catalysts can be used alone or in admixture with one or more of the different types of compounds described above.

The amount of catalyst used can be varied widely, but the catalysts are effective in extremely small amounts, e.g. 0.025 parts by weight per 100 parts of the mixture. Various types of catalysts, e.g. tertiary amines and organotin compounds, vary in effect intensity, but usually the more catalyst used, the faster and more intense the polymerization.

The following examples are provided to illustrate the present invention. Parts and percentages are by weight and temperatures are given in degrees Celsius.

Example 1.

A mixture of 66.6 parts polypropylene ether glycol ("Pluronic P-1010", Wyandotte Chemical Corp.) having an average molecular weight of 1000, 15 parts 1,4-butanediol and 44.4 parts of a mixture of 80 percent 2, 4 and 20% 2,6-tolylene diisocyanates were mixed and heated to 80°. Then 0.5 parts of N-ethylmorpholine was added and the mass was vigorously stirred for 45 seconds and then degassed under a vacuum of 5 mm pressure for 2-3 minutes. The mixture was heated in an oven at 110° for approx. 50 minutes and the resulting more viscous mass was poured into a hollow mold and preheated to medium

110° and 130° and heated in the mold under pressure at 135° for 1 y2 hours. The product was removed from the mold and cured at 110° for approx.

16 hours.

The resulting urethane elastomer had the following properties:

Example 2.

A mixture of 120 parts of polypropylene glycol having an average molecular weight of 1000 (hydroxyl no. 56), 30 parts of 1,4-butanediol and 5.9 parts of 4,4'-methylene-bis-(2-chloroaniline) was heated to 90° and stirred in vacuo until the diamine was dissolved. 0.025 part of stannous acetate was added to the solution and then cooled to 80°, at which temperature 93.7 parts of a mixture of 80% 2,4- and 20% 2,6-tolylenediisocyanates were rapidly added. The mixture was stirred vigorously for less than 1 minute and then completely in a preheated mold. The mass "hardened" within 25-28 minutes and was kept in the heated form ("pre-hardened") for approx. 10 minutes. The exothermic peak was approx. 170°. The product was removed from the mold and cured at approx. 100° for 20 hours.

The resulting elastomer had the following properties:

Example 3.

The procedure described in Example 2 above was repeated using 23.8 parts of 4,4'-methylene-bis-(2-chloroaniline) instead of 5.9 parts of this reaction component, and the mixing of the components was carried out at atmospheric pressure rather than in vacuum.

The resulting elastomer had the following properties:

Example 4.

100 parts of a polypropylene ether glycol with a molecular weight of approx. 1000, 22.5 parts 1,4-butanediol, approx. 37 parts 4,4'-methylene-bis-(2-chloroaniline), 95.7 parts tolylene diisocyanate

(a mixture of 80 per cent 2,4- and 20 per cent 2,6-tolylene diisocyanates) and 0.05 part stannous octoate were mixed together by first mixing the glycols and amine at 80-90° until the amine had dissolved in the mixture, and after slight cooling (to approx. 60-80°) the tin catalyst and the isocyanate were added. This mixture was vigorously stirred for approx. 1 minute and pour into a suitable preheated mould. The mold was heated under pressure at approx. 100-140° for approx. 20-30 minutes. The elastomer product was cured for approx.

16 hours at approximately 100°. The resulting

urethane elastomers had high tensile strength along with excellent elongation, modulus, tear strength and hardness.

Example 5.

A mixture of 66.6 parts polypropylene ether glycol having an average molecular weight of 1160 (Solvay Polyether P-630), 15.6 parts 1,4-butanediol and 7.9 parts 4,4'-methylene-bis-(2-chloroaniline) ) was heated to 90° until the arylene diamine had dissolved in the mixture. The mass was then cooled to 60° and a mixture of 0.05 parts of stannous octoate and 48 parts of a mixture of 80% 2,4- and 20% 2,6-tolylene diisocyanate was added to the previously prepared solution . This mixture was stirred vigorously for 20 seconds, then poured into a preheated hollow mold (110-130°) and heated for 1 hour at 135°. The product was removed from the mold and cured in an oven at 100° for 16 hours.

The urethane elastomer had the following physical properties:

From the preceding examples it will be seen that a simple and efficient "one-step" process has been provided for the production of urethane elastomers. The new products following the method are characterized by relatively high tensile strength, modulus, tear strength and other desired properties. Moreover, it has been shown that the properties of these elastomers can be varied to obtain "soft" or "hard" elastomers as desired.

The use of relatively large amounts of alkylenediol and/or polyisocyanate and/or arylene diamine results in an elastomer product with high tensile strength, modulus and tear resistance. As the tear strength and modulus increase, the elastic nature of the polymer is lowered, and consequently, depending on the particular end use proposed for

the elastomer, the amounts can be adjusted to

obtain a polymer having the desired

mixture of strength and elasticity properties.

Claims (1)

Process for the production of non-cellular urethane elastomers which involves simultaneously reacting a polyisocyanate, a polyalkylene ether glycol, which has a molecular weight of 500-2500, preferably 700-1300, and a lower hydrocarbon alkylenediol, preferably 1,4-butanediol, in the presence of a catalyst, characterized in that said components are reacted in the following conditions: and optionally in the presence of a difunctional chain-extending agent, preferably an arylenamine, in an amount of less than that which would give 0.20 of a functional group for each hydroxyl group present, preferably less than that which would give 0, 10 of a functional group for each hydroxyl group present.