DE1595256A1 - Hardenable urethane compounds - Google Patents

Description

intended for,
Disclosure

P 15 95 256.4 31. January 1969

Polio 5916

Allied Chemical Corporation, New York, N.Y., USA

Curable urethane compositions

The invention relates to curable urethane compositions which have a content of chain extender.

As is well known, elastomeric urethane polymers can be made. By using an essentially linear polymer, such as a polyester or a polyester which has terminal hydroxyl groups with an organic polyisocyanate Reacts in excess, with by reaction with the hydroxyl groups of the polymer is an essentially linear polyurethane which still contains free isocyanate groups, is formed, and this polymer is then mixed with a functional compound, such as an Olykol. a diamine, an amino alcohol or a mixture of such compounds. In implementing these failures

909834/1351

BATH ORIGINAL

Component with the free isocyanate groups of the urethane prepolymer, crosslinking and / or lengthening takes place of the linear chains of the polymer until the polymer becomes hard or rigid. In general, the hydroxyl-rich polymer and the organic polyisocyanate are first reacted in such a quantitative ratio that a polymer with free isocyanate groups (NCO) is formed and this Polymer is then, usually with the application of heat and pressure, with the functional compound, i.e. the Chain extender, implemented. This second stage of the process can be referred to as curing.

The curing is carried out in this way. that the prepolymer mixed with the chain extender, usually at an elevated temperature, and preferably mixed thoroughly. The mixture is then poured into molds and cured or heated by the application of heat and / or pressure Rolls processed and formed into foils.

The mixture of prepolymer and chain extender only remains liquid or pourable for a relatively short time, i.e. the curable urethane composition is only useful for relatively short periods, so that these mixtures can be used in small Approaches that are only sufficient to fill a small number of molds need to be produced,

909834/1351

8AD ORIGINAL

Also the filling of the forms, especially those of more complicated shape, this makes it more difficult and ultimately there may be occlusion of oasis bubbles in the thickened Mass can, so that the moldings obtained flaws exhibit. In particular if the masses are kept at a temperature above that of the surroundings for a longer period of time, they do not remain fluid enough to be poured into molds. However, there are elevated temperatures both for the preparation of the prepolymer and for its curing are required, the difficulties which the large-scale implementation of the Adhere to the procedure, increased.

The object of the invention is therefore a curable urethane composition with a long usability period, which on the one hand hardens easily and at relatively low temperatures, but on the other hand remains pourable for a long enough time to achieve a thorough mixing of prepolymer and chain extender as well as the production of large quantities to enable such masses.

The subject of the invention is a curable urethane composition. the a urethane prepolymer that still contains free isocyanate groups contains, and a chain extender that predominantly consists of an aryldiamine contains. The crowd is through it marked that they are used as a means of extension

909834/1351

BATH O.

contains an organotin compound in its shelf life.

Organic tin compounds are in the field of polyurethanes known as catalysts, i.e. as reaction accelerators »so that the anti-catalytic or slowing effect that they exert in the curable urethane compositions of the invention is extremely surprising.

The curable urethane compositions of the invention are immediate after they are made, they are liquid and pourable and remain so for longer periods of time. When cured, they form elastomeric polyurethanes with multiple uses. You can be cast or deformed into bodies of complex shapes. Examples of such items are tires, vibration-dampening brackets, drive wheels, propellers, sleeve bearings, shaft covers, gear drives, drive belts, Helmet linings and gas masks.

The urethane prepolymers. their production and that for theirs Materials used in manufacture are known. The preparation takes place, for example, by adding a polymer with terminal hydroxyl groups, for example a polyester polyol or a polyalkylene polyether polyol with a average molecular weight of at least 500 and a hydroxyl number of at least 40 at one temperature

909834/1351

BATH

between about 50 and 100 ° C with an organic polyisocyanate implemented in% schuQ. The organic polyisocyanate is preferred Used in an excess corresponding to at least one molar equivalent of isocyanate. However, up to 12 or more Equivalents of isocyanate per equivalent of hydroxyl groups are used. In the masses of the invention are preferred Prepolymers containing 4-R £ free isocyanate groups, used.

The polymer with terminal hydroxyl groups used for the preparation of the prepolymer can, for example a polyester polyol, including polyester amide polyols, or a polyether polyol including polyether thiols. Those polyols are preferred which essentially are linear and have a functionality of about 2.

The polyester polyols are known and can be used in a conventional manner Way, for example by making a Basic acid or a mixture of dibasic acids with a Olykol or a mixture of glycols. Suitable organic acids are, for example, amber. Glutar, Adipine, Pimelln, Cork, Azelaine, S bacine and Terephthalic acid. Suitable glycols are, for example, ethylene glycol, 1,2- and 1,3-propylene glycol and 1,4-butylene glycol and hexamethylene glycol. Preferred are polyesters of adipic acid and a mixture

909834/1351

used by ethylene and 1,2-propylene glycol. The polyester may have an average molecular weight of at least 500, and preferably have an average molecular weight of 1000 to 2500, a hydroxyl number between about 40 and 115 *, preferably between 50 and 70, and a low one Acid number of preferably below 5

The polymer with terminal hydroxyl groups can also be a polyether polyol, for example a polyalkylene ether glycol. be. These glycols are also known and a number of them are commercially available. You probably have that general formula

R.
HO (CH ₂ -CH-O) _x H.

where R is hydrogen or a low molecular weight alkyl group and X is an integer and is large enough that the molecular weight of the polyether glycol is at least 500 and preferably is in the range from 1000 to 25ΟΟ. Suitable glycols of this type are polyethylene ether glycol and polypropylene ether glycol and polybutylene ether glycol. Such polyether glycols can be obtained by condensing an alkylene oxide or a mixture of alkylene oxides, such as ethylene oxide, Propylene oxide and its mixtures with a polyhydric alcohol, such as ethylene glycol, in the presence of a catalyst, for example trimethylamine or potassium hydroxide obtained

909834/1351

BATH ORIGINAL

will. The production of such polyalkylene ether glycols is known.

Many different organic polyisocyanates can be reacted with the polymeric polyols for the production of the urethane prepolymer. For example, aromatic, aliphatic and cycloaliphatic isocyanates can be used. Liquid aromatic diisocyanates are preferably used. Examples of these known isocyanates are 1,4-phenylene diisocyanate and 2,4-toluene diisocyanate. 2,6-toluene-dilsocyanate, 1,5-naphthalene-disocyanate, 4,4 * -methylene-bis- (phenyl isocyanate), cumene-2,4-di-isocyanate, 4-methyl-1,3-oyolohexyl-disocyanate. 4,4 ^t -methylene bs- (eyclohexylieocyanat), 1,6-hexamethylene diisocyanate and the polyalkylene polyaryl polyisocyanates described in US Pat. No. 2,683,720. If desired, mixtures of these and equivalents of isocyanates can also be used. Particularly preferred is the commercially available mixture of about $ 0% 2,4- and about 20% 2,6-tolylene diisocyanate in pure or crude form.

The chain extender that is present in the curable urethane compositions of the invention consists predominantly i.e. to more than 50 ow .- ^ from an aryl diamond and can Contains up to $ 100 aryldlofnin. In a smaller amount

909834/1351

however, other chain extenders such as low molecular weight glycols and aminoalkanols with 2-10 carbon atoms can also be present and are preferably present in a smaller amount, ie in an amount of less than 50% by weight of the average chain extension. The aryldiamines are known as chain extenders in the manufacture of elastomeric polyurethanes. They are also sometimes called hardening agents. Their reaction with the prepolymer is presumably a crosslinking through which the polymer is solidified. With the aryl diamonds, elastomeric products with excellent tensile strength, hardness and other advantageous physical properties and thus versatility are obtained. Examples for usable aryldiamines are: 4.4 ^t -methylene-bis- (2-chloroaniline), 4.4-methylene-bis- (2-bromaniline). 4,4'-methylenebis (2-roethoxyaniline), 4,4'-methylene-bis- (2-hexylaniline), 4 _> 4 ^> -methylene-bis- (2-ethylaniline), 1,5-naphthalenediamine <2.2 ^I -Dichlorobenzidine and Dianisldine. Mixtures of these and equivalent aryldiamines can also be used. Examples of the other components that may be present in the chain extender are alkylene diols such as ethylene glycol and 1,4-butanediol, as well as aminoalkanols. such as 2-aminoethanol and 3-aminobutanol-1 and mixtures thereof.

The chain extender is in the curable urethane

90983A / 1351

In general, compositions of the invention in an amount of 5-25 #, based on the total weight of the composition and preferably in an amount of 10-20 wt -.% present. However, depending on what properties the elastomeric product is intended to have, other amounts of the chain extender can be used.

The organotin compounds present in the compositions of the invention are known in the polyurethane art. . In combination with the other components of the curable urethane composition of the invention, when they are used in the amounts indicated, they do not have an accelerating, but rather a retarding effect and extend the otherwise undesirably short useful life of such a composition. The organotin compound is preferably present in an amount of 0.15-0.4 %, based on the total weight of the curable urethane composition, and the optimum amount range is between 0.20 and 0.35%

R / -J R «

| 2 il

R ₁ -Sn-OR or Sn - OR "3

where R is an acyl radical, such as an acetyl, propionyl, octanoyl or lauroyl residue 1st. R-, Rg and R, either OR or alkyl

90983A / 1351

reete with 1-18 carbon atoms, hydrogen or halogen atoms and are the same or different, are shown will. Examples of these organotin compounds are: dimethyl tin dioctoate, dioctyl tin diacetate, stannol laurate, Stannous hexanoate, tributyltin-o-phenylphenolate, stannous octoate, Stannooleate, stannotartrate, dibutyltin di- (2-ethylhexoate), Dibenzyltin di (2-ethylhexoate). Dibutyl xine dilaurate. Dibutyltin bis (o-phenylphenolate), dibutyltin bis (acetylacetonate), diaenzyltin dioleate, dlbenzyltin dilaurate. Dietary tin dilaurate, dilauryl tin dibutyrate. Dibutyltin dibutyrate, butyltin dibutyrate caproate. Benzyl tin trietearate, Stannosuocinate and stannoadipate. Are particularly preferred Stannous octoate and dibutyltin dilaurate as they are light are available and have a good effect.

In some cases, the organotin compound can also be used in quantities present outside the preferred range given above.

If for the preparation of the prepolymer, in deviation from the usual method for the preparation of the same, a Organotin compound is used as a catalyst, the amount of organotin compound getting into the prepolymer must be in the range given above be brought by either removing organotin compound or a further amount of organotin compound

909834/1351

adds _μ κ »ηκ the desired extension of the duration is to be achieved.

The chain lengthening agent can be added to the urethane prepolymer containing free isocyanate groups in an amount which is generally in the range of 80-100% of the theoretically required amount for reaction with all free isocyanate groups in the prepolymer. The choice of diamine or a mixture of diamine and CUykol or aminoalkanol or another chain extender depends largely on the properties of the elastomeric product. Since this is well known from the literature, a more detailed discussion is not necessary.

The urethane compositions of the invention also include those which IUr the production of curable urethane compounds with a content of a chain lengthening agent, which mainly consists of an aryldiamine, and an organotin compound in an amount that extends the useful life of the urethane maese.

The following examples illustrate the invention. Parts and percentages relate to the Gewloht.

909834/1351

example 1 Part A - Preparation of the prepolymer

A urethane prepolymer was prepared in the usual way by adding a mixture of γοη 4.4 ^l -methylene bis (phenyl isocyanate) and ethylene propylene adipate (a polyester made from a mixture of ethylene and propylene glycol in a ratio of 80:20 and adipic acid with a average molecular weight of about 2000 and a hydroxyl number of about 56.1 mg KOH / g) heated to about 80 ° C. for about three hours. Diisocyanate and polyester were used in such proportions that 5.2 NCO groups were present per OH group. The prepolymer formed contained 5> 74 pounds of free NCO groups.

Part B - production of a curable urethane mass without

Tin salt

A mixture of 5.75 parts of 4.4 ^l -methylene-bis- (2-chloroaniline) and 1.75 parts of 1,4-butanediol was heated to 1OCC and then to 70 parts of the prepared as described in Part A and to 10W heated urethane prepolymer8 added. The mixture was stirred for 15-20 seconds and then poured into a mold preheated to 50 ° C. The mixture had a usable time of 70 seconds.

909834/1351

Part C - Making a curable urethane composition with

Following the procedure of Part B of this example but with the addition of 0.24 parts (0.31 $) Stannoootoat was obtained a curable ürethanmasse with a usable life of 230 seconds at IjJO ⁰ C.

The useful life was determined by using the The mixture was poured into a mold preheated to the specified temperature and carefully observed. The time after mixing of the components elapsed until the mass was no longer flowable, was noted as the useful life. The flowability of the mixture was determined by pressing a wooden stick into the hardenable liquid. If the The cavity formed by the wooden stick no longer closes when the stick is removed, the mixture becomes referred to as no longer flowable.

Example 2

Part A

A Gemisoh of 73 ¹ K? Parts of polyoxypropylene diol with an average molecular weight of 1000 and a hydroxyl number of about HO mg KOH / g and 3272 parts of a mixture of about 80 # 2,4- and about 20 # 2,6-toluylene diisocyanate were heated to about 70 ° C and about 4 Maintained for 1/2 hour at a temperature between 59 and & yc . The educated

urethane

909834 / Ί351 _BAD original

polymer was cooled to ambient temperature. It had an amine number of 544 and contained £ 7.74 free NCO groups.

part B

To 70 parts of the urethane prepolymer prepared as described in Part A and mentioned above at about 110 "C were added 15-5 parts of molten (1 (XlK) 4,4 ^> -methylene-bs- (2-chloroanllln)) and the mixture became about Vigorously stirred for 15 to 20 seconds, then poured into a 130% preheated mold for 65 seconds.

Example 3

A mixture of _{7/58 parts of 4 i} 4 ^f -ethylene-bis (2-chloro-aniln), 2.56 parts of 1,4-butanediol and 0.20 parts (0.25 / 0 of starmooctoate was heated to 100% and then as described to 70 parts heiSem (about 11Οι) urethane prepolymer, prepared in part a of example 2} was added. The mixture was stirred vigorously for 15 seconds and then poured into a pre-heiste to 13O ⁵ C shape. The Verwendbarkeitedauer this curable Urethangemisehes was 240 seconds. ;

Example 4 As described in Example 2, a mixture of 15> 5 parts

BATH

4,4'-methylenebi- (2-chloroaniline) and 0.24 parts (£ 0.28) 3terinooctoate is 70 parts of that described in Example 2, Part A. Urethane prepolymer mixed. A curable urethane composition having a usefulness date was obtained. he of 90 seconds.

Example 5

A mass equal to that of Example 4 was produced, with the difference, however, that the amount of stannous oil was increased from 0.24 parts to 0.> 7 parts (0.2 k}%) . The usable time decreased to 45 seconds.

Example 6

A mass was produced like In Example? described, with the difference, however, that a mixture of 9 * 3 parts 4,4 »-Methylene-bia- (2-chloroaniline), 2.09 parts 1,4-butanediol and 0.23 part (0.26 pounds) of stannous octoate was used. A curable urethane composition was obtained with a useful life of 195 seconds at 150.degree.

Example 7

A composition was prepared as described in Example 3, with the difference, however, that 11.6 parts of 4.4 ^f -ethylene-bie- (2-chloromilin), 1.3 parts of 1,4-butanediol and 0.24 parts (0.29Jf) stannous octoate were used. A curable urethane composition was obtained with a useful life of 110 seconds at ÜXTC.

909834/1351

BATH ORIGINAL

Example 8

Example 7 was repeated with the difference that 0.18 parts (0.22 #) stannous octoate instead of 0.24 parts were used. A curable urethane composition having a useful life of 95 seconds was obtained

Examples 9-13

Part A - Preparation of the prepolymer

A mixture of 500 parts of ethylene propylene adipate (molecular weight 2000, hydroxyl number 56.1) and 85 parts of a mixture became from about 80 # 2,4- and about 20 $ 2,6-tolylene diisocyanate heated to 8C ^ C and kept at this temperature for 3 hours.

In another vessel, 31 parts of ethylene glycol were added dropwise at 150-95 ° C. to 183 parts of hot (85-9CTC) mixture of 2,4- and 2,6-tolylene diisocyanate. The composition formed was heated for half an hour to 90-95 C ¹ after the addition of the glycols. 146 parts of the adduct were then prepared as described above the Polyestervorpolymerisat added and the mixture was heated for 3 hours at 8O ⁰ C. The prepolymer obtained contained 6.2 $ free NCO.

part B

From 70 parts of the urethane prepolymer from Part A

909834/1351

BATH ORIGINAL

a mixture of 50 molar equivalents of 4,4 * -methylene-bi8- (2 ~ chloroaniline) (6.2 parts) and 50 moles of # 1,4-butanediol (2.1 parts) and no organotin compound or various amounts of organotin compound were curable Urethane compounds produced. The influence of concentration on the tin compound on the useful life of the curable urethane composition is the values in the following table remove:

At »tin concentration, % usability«

duration, sec.

9 no 0.227 0 75 10 A. 0.227 0.29 180 11 B. 0.109 0.29 150 12th A. 0.544 0.14 75 13th A. 0.44 60 Annotation: Λ is Dibutyltin dilaurafc Are you Stannous oat

909834/1351

Claims (6)

Pat η e tansprüctie l.j HSartable urethane mask, which is a urethane prepolymer, "which contains nooh free ssoeyanate groups, and a chain ver · extension frame, which mainly consists of an aryldlamine, contains, thereby golcennzelehnet that they as a means an organotin to extend your usable life « connection contains. 2. Curable urethane composition according to claim 1, characterized in that it contains 0.15-0, ^ 0% by weight , in particular 0 ^ 20 = 0.35% by weight, of the organocin compound. 3. Curable urethane composition according to claim 1 or 2, characterized known that they contain all organo-stannous octoate or dibutylsense dilaurate 4. Use of a compound according to one of the preceding Claims in the production of polyurethane elastomers. 5. A method for producing a composition according to any one of claims ί to 3 » characterized in that a urethane prepolymer which still contains free isocyanate groups 909834/1351 holds, a chain extender that consists primarily of a Arylenediamine consists, and an organotin compound in such Amount that the useful life of the hater is thereby extended. 6. mass which is suitable for use in a curable urethane composition, and includes a chain extender which consists mainly of an aryl diamine, characterized in that it 3se as a means to extend the Verwendbarkeitedauer the curable Urethanmr still contains an effective amount of an organotin compound . 909834/1351.