DE1056821B - Process for the production of crosslinked polyether urethanes - Google Patents

Description

The subject of British patent specification 733 624 is a process for the preparation of curable polyether urethanes, wherein at least 1.2 moles of one or more activating groups, such as the nitro group, are free bifunctional isocyanates with 1 mole of one or more linear isocyanates under essentially anhydrous conditions Polyethers of the formula HO (RO) ₀ H, where R can be various divalent linear aliphatic hydrocarbon radicals, which can be the same or different, and α is an integer whose value is such that the average molecular weight of the polyether is greater than 1000 .

In accordance with the present invention, there is provided a process for the preparation of rubbery crosslinked polyether urethanes proposed in such a way that one prepared by the method described above, Polyether urethane containing free isocyanate groups with dif non-functional compounds, such as water or steam, also glycols or with ammonia or with Treated compounds containing at least three OH groups and an elevated temperature suspends during shaping.

The method of the invention can either be used as a casting process in which the material to be cast is in an open mold to form a rubber-like plate, or as a molding process in which the material to be molded is subjected to heat and pressure to form the molded body is subjected. In the casting process, the polyether urethane used should preferably be linear, because this makes the casting process easier. On the other hand, when molding under pressure the Forms the final stage, the material fed to the mold should to a certain extent be cross-linked, Heat and / or kneading treatment should be modified as far as possible. The material should just be like that be widely networked that it can still be deformed. This level is usually reached when the material has the crepe shape which is heated on Rolling can be processed.

The polyether urethane can be crosslinked to a rubbery material in the presence of a basic catalyst. The catalyst can be organic or inorganic in nature and should preferably not contain any groups which react with isocyanate groups. Examples of catalysts are: alcoholates (sodium methylate or sodium ethylate), inorganic bases (calcium oxide or hydroxide, barium oxide or hydroxide, beryllium hydroxide, lithium hydroxide and sodium hydroxide) and tertiary organic bases (trimethylamine, triethylamine, tripropylamine, tributylamine, triamyl process for production
of crosslinked polyether urethanes

Applicant:

Imperial Chemical Industries Limited,
London

Representative: Dipl.-Ing. A. Bohr, Munich 5,

Dr.-Ing. H. Fincke, Berlin-Lichterfelde, Drakestr. 51,

and Dipl.-Ing. H. Bohr, Munich 5,

Patent attorneys

Claimed priority:

Great Britain from April 10th to June 27th

and November 13, 1952

Arthur Colin Baskett, Croydon,
George Arthur Rooke Matthews, Letchworth,
and Hugh James Spencer-Palmer, Knebworth

(Great Britain),
have been named as inventors

amine, tribenzylamine and dimethylaniline). The amount of the catalyst required is usually within the range of 0.05 to 0.5% based on the weight of the polyether urethane. If the polyether urethane with the less reactive Diisocyanates such as aliphatic diisocyanates are the more reactive ones Catalysts, such as the alkali hydroxides, work best.

The property of the end product depends on the uniformity with which the reaction proceeds, when the polyether urethane is heated in the presence of the catalyst. The polyether urethane can also use other auxiliaries, for example Dyes.

If the reaction mixture is sufficiently liquid, the crosslinking can only take place in one Mixer done. In other cases, only the first reaction can be carried out in a stirring mixer

90 & 509/459

will. The final stage is then preferably carried out on heated rollers or in a mixer of the Banbury type. The treatment temperature depends on the type of crosslinking agent. When working with water, the reaction can be carried out at a temperature below 100 ° C, for example 80 ° C, but it is preferred to be 120 to 160 ° C If the material is further reacted with kneading, it is preferred to carry out this further reaction at 103 to 140 ° C. The reaction with steam is preferably ^{carried out at temperatures:} from 120 to 160.degree. C., which is then, if desired, followed by a kneading treatment, for example at 103 to 140.degree. On the other hand, when working with diamines, dicarboxylic acids and amino acids, the polyether urethane is expediently cooled in order to bring about a thorough mixing of the starting materials before the further reaction takes place at the higher temperatures.

In the case of the use of steam and ammonia, these crosslinking agents can be applied the surface of the mass are blown.

Compounds which have two groups, each of which is reactive with the isocyanate group are: glycols, diamines, with primary or secondary amino groups, dicarboxylic acids, hydroxylamines, Hydroxy acids and amino acids. Suitable compounds are, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, ethylenediamine, trimethylenediamine, Tetramethylenediamine, m-phenylenediamine, Naphthyleridiamine, "toluene-2,4-diamine, Aminobenzylaniline, aminodiphenylamine, 2-aminoethyl alcohol, 2-amino-l-naphthol, m-aminophenol, Glycolic acid, a-hydroxyproplic acid, aminoacetic acid and aminobenzoic acids "■ The applied bifunctional Compound should have a relatively low melting point, for example one below 150 ° C for easy mixing.

- The choice of connections, -which best to use Modification of the polyether urethanes that are suitable depends on the reactivity of the during manufacture of the polyether urethanes applied isocyanates. If therefore remaining, proportionately less reactive aliphatic isocyanates are present, the crosslinking agent should, for example Water, ammonia, an amino or carboxylic acid, so that the crosslinking is relatively quick going on. If one of the less reactive crosslinking agents, for example 1,4-butanediol, is used, it is best used in conjunction with a basic catalyst. However, if residues of an aromatic diisocyanate are present, a reactive crosslinking agent is like an aliphatic diamine, usually not suitable, at least it should 'in the case of' an aromatic one Diamine have inhibiting groups in the core, for example S.S'-dichlorobenzidine.

Water can be added in the form of a hydrous salt, for example as sodium sulfate decahydrate are ... For water:! the amount is usually between 0.4 and 1.5 percent by weight of the to be treated Materials. > '■ ■

■ .Furthermore, polyhydroxy compounds are suitable, which three or more primary; and / or secondary alcohol groups contain / wherein compounds are preferred which have melting points of less than 150 ° C. Examples! Of such connections are ": Glycerin-PentaBEyih'ätAiTrlhydroxy ^ tert .'-butane, Trimethylolpropane, trimethylolethane and 1,2,4-butanetriol or low molecular weight novolak resins. Mixtures of such compounds can also be used be used. '

5. The polyether urethane is reacted with the mentioned bi- or trifunctional compounds usually molded as a crepe or cast into a desired shape. However, it can also be in the form of Ribbons, films, plates, threads, and webs

ίο Solutions or dispersions are converted for covering and impregnation purposes. The formation of the molded rubber-like, completely crosslinked resin is best done by about 10 to 30 minutes long heating the crepes having a partial crosslinking, to an elevated temperature, for example of 140 to 170 ⁰ C, gegebi'iH-nIf under a pressure of the order of 78.7 to 157.5 kg / cm ² .

The casting process can be carried out in such a way that the polyether urethane after the addition the bifunctional compound, preferably in a substantially linear state and if necessary at elevated temperature, poured into an open mold and heated without the use of pressure. Even if the polyether urethane has been reacted with a compound, for example water or steam, which leads to gas evolution during the reaction, can be achieved by heating the reaction product an expanded rubbery material can be obtained in a suitable form. The formation of this rubbery material can be accelerated or carried out at a lower temperature, by that obtained by reacting the synthetic resin with a bifunctional compound A suitable catalyst is incorporated into the product,

■ ·: for example an inorganic or organic one basic compound of the type described above. When the bifunctional compound is a diamine or contains an amino group, the use of such a catalyst is usually not necessary.

In each work stage before the last heating stage, auxiliary materials, such as Fillers, plasticizers, extenders, pigments or other substances are incorporated.

In the case where it is not intended, however, the mass immediately after its production in a transferring rubbery material, it should be cooled to room temperature or below.

The relative amounts of the polyhydroxy compound

■> and the polyether urethane are preferably such that the hydroxyl groups and terminal isocyanate groups are present in substantially equivalent amounts. It is preferred to have an excess to avoid hydroxyl groups compared to the isocyanate groups, because such hydroxyl groups on the Networking do not participate and are therefore superfluous. Such a disadvantage occurs with the Presence of a small excess of isocyanate groups does not occur, since these do not have such a limiting

C Effect on the structure of the rubbery material own.

The present invention is illustrated in the following examples. The parts are parts by weight.

■ '·. ■' · '■

₍ . B eis ρ ie 1 1

50 parts of the as in the example! of the British patent specification 733 624 described manufactured product were placed in a cold mold and with 1.5 parts of water moistened. The shape was on

1 O 5 6 8

Heated to 160 ° C, closed and held under a pressure of 78.7 kg / cm ² for 30 minutes. The material formed into a disk in the mold was removed from the mold. This was highly transparent and had a tensile strength of 98.4 kg / cm ² and an elongation at break of 700%.

Example 2

To the product prepared from 100 parts of polymerized tetrahydrofuran and 12.5 parts of tolylene diisocyanate in the manner described in Example 2 of British Patent 733,624, 0.35 part of tolylenediamine was added. After 40 minutes of further mixing, the reaction product was transferred to a double-roll calender, the rolls of which were heated to 103 and 110 ° C., respectively, whereby a uniform crepe was obtained. The product was then molded into a disk in a mold by heating the mold to 140 ° C and performing molding treatment under a pressure of 78.7 kg / cm ^{2 for} 15 minutes. A tough, rubbery material was obtained.

Example 3

(a) 20 parts of the product prepared from polymerized tetrahydrofuran and tolylene diisocyanate as described in Example 3 of British Patent 733,624 were mixed with 0.1 part of triethylenediamine at 140.degree. The mixture was quickly poured into a flat mold so that a thin layer was formed in that mold. The mold was then held at HO ⁰ C for 16 hours. The pale brown, clear, tough gum product was then removed.

(b) Another 20 parts of the product was mixed with 0.26 parts of 1,4-butanediol. The mixture was heated to 140 ° C and poured into a flat mold which was ^{heated to HO 0} C for 16 hours. The pale brown, clear, tough gum product was then removed.

Example 4

Densationsprodukts from octylphenol with 10 molar parts of ethylene oxide and 0.48 parts of the sodium salt of sulfated methyl oleate added. After thorough mixing, the liquid reaction mixture was poured into a mold in which it was heated and foamed. The product was a foam-rubber-like fabric with a density of 0.034 g / cm ³ .

B e i s ρ i e 1 6

ίο The 100 parts polytetrahydrofuran and 8 parts of naphthylene-1,5-diisocyanate as described in Example 11 of British Patent 733,624 prepared Product was added to 0.25 parts glycerin and mixing continued for 35 minutes.

The product was brought from the mixer onto a two-roll calender, the rolls of ^{which were kept at HO 1} or 103 ° C. The treatment on the rollers lasted for 10 minutes. The crepe was removed from the calender and molded in a mold heated to 140 ° C. and under a pressure of 78.7 kg / cm ² for 15 minutes to form a plate. The plate was kept removed from the mold and for 15 minutes at 8O ⁰ C. The end product was a tough clear rubber.

B e i s ρ i el 7

In the one out of 100 ^! Parts of polytetrahydrofuran and 16 parts of naphthylene-1,5-diisocyanate as described in Example 12 of British Patent 733,624 product obtained were 0.24 part of sodium sulfate decahydrate, which corresponds to an equivalent amount of 0.13 part of water, stirred in and stirring for 1 hour continued. The product was then placed on a two-roll calender, the rolls of which were heated to 110 and 103 ° C, respectively. The uniform crepe was then shaped as a skin in a mold which was heated to 140 ° C. and under a pressure of 78.7 kg / cm ² . This treatment lasted 15 minutes. The plate was then removed from the mold and held at 80 ° C for 15 hours.

To the product prepared from 100 parts of polytetrahydrofuran and 14.5 parts of naphthylene-1,5-diisocyanate as described in Example 9 of British Patent 733,624, 0.65 parts of glycerol were added and mixing was continued for 35 minutes. The product was transferred from the mixer into a two-roll calender, the rolls of which were kept at 110 and 103 ° C., and treated there for 10 minutes. The crepe was removed from the calender and placed in the form of a sheet in a mold which was held at 140 ° C. for 15 minutes and was under a pressure of 78.7 kg / cm ² . A transparent gum was obtained which was heated to 80 ° C. for 15 hours. The product obtained had a tensile strength of 16.9 kg / cm ² and an elongation at break of 620% and very little permanent set.

Example 5

1300 parts of an acid-free polypropylene glycol with a molecular weight of 1940 and a water content of 0.02% were with 503 parts of an 80:20 mixture of toluene-2,4- and 2,6-diisocyanates implemented.

A mixture of 2.14 parts of water and 1.07 parts was added to 100 parts of the polyurethane thus formed Ν, Ν-dimethylcyclohexylamine, 0.71 parts of the

Claims (2)

Patent claims: 1. A process for the preparation of crosslinked polyether urethanes, characterized in that the polyisocyanates free from activating groups such as nitro groups with 1 mol of one or more linear polyethers of the formula HO ( RO) ₀ ^- H, where R denotes various divalent linear aliphatic hydrocarbon radicals, which can be the same or different, and α is an integer whose value is such that the average molecular weight of the polyether is greater than 1000, under essentially anhydrous conditions The resulting polyether urethanes containing free isocyanate groups are treated with compounds which are difunctional with respect to isocyanate groups or with compounds containing at least three hydroxyl groups and exposed to an elevated temperature during molding. 2. The method according to claim 1, characterized in that the amount of opposite isocyanate groups multifunctional connections are sufficient to create a network between only one I 056 821 7 ■ 8 Part of the isocyanate groups of the polyether urethane 4. The method according to claim 1 to 3, characterized bring about. characterized that the treatment in opposite , 3. The method according to claim 1 and 2, characterized waiting for a basic catalyst made characterized as being the treatment of the poly. ether urethane with the opposite isocyanate groups _; 5 5. The method according to claim 4, characterized multifunctional compound at a temperature indicates that a ter- temperature of 120 to 160 ° C takes place. tertiary amine is used. © 909 509/459 4.59