DE1252892B - Process for the production of homogeneous polyurethane elastomers - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. CI .:

C08g

German K] .: 39 b -22/04

Number: 1 252 892

File number: D 43708IV c / 39 b

Filing date: February 22, 1964

Opening day: October 26, 1967

The invention relates to a process for the production of homogeneous polyurethane elastomers of polyesters, polyethers or polyester amides and polyisocyanates or polyisothiocyanates according to the Prepolymer process by crosslinking the prepolymers with high-melting polyamines.

Polyurethane elastomers are usually prepared by first reacting a polyester, polyether or a polyester amide with a polyisocyanate or polyisothiocyanate to form a polyester, polyether or polyester amide modified with polyisocyanate or polyisothiocyanate, which is usually referred to as a prepolymer, and then reacting the crosslinking reaction of this prepolymer with a causes a melting point of below 110 ⁰ C having crosslinking agent.

Since the polyisocyanate is very reactive, the regulation or control of the reaction is very important in this production method. In the known procedures, the temperature of the prepolymer is kept below HO ⁰ C, and a solid crosslinking agent with a melting point of below about 110 ⁰ C is melted and added. When using a crosslinking agent with a high melting point of above 120 ^° C., for example o-dichlorobenzidine, o-methylbenzidine or 1,5-naphthylenediamine, a solution of these compounds in a solvent, e.g. B. Dimethylformamide, dioxane or the like. Added to the prepolymer in order to effect the crosslinking reaction. When the polyurethane elastomers obtained by the known procedures using crosslinking agents were tested for their mechanical strength, it was found that the products obtained using crosslinking agents with a high melting point of above 120 ° C. have superior properties. When using high-melting crosslinking agents in accordance with the above-described procedure, however, particularly when using the urethane elastomer as a rubber, it is necessary to remove the solvent before casting or molding, which is a considerable problem. There is also known a method according to which the crosslinking agent having a melting point above 120 ⁰ C the prepolymer at a temperature below its melting point without using a solvent is added directly. However, a uniform elastomer cannot be obtained, with the result that the elastomer thus formed has very poor mechanical strength.

Process for the division of homogeneous
Polyurethane elastomers

Applicant:

Dainippon Ink and Chemicals,

Incorporated, Tokyo

Representative:

Dr. E. Wiegand and Dipl.-Ing. W. Niemann,

Patent Attorneys, Munich 15, Nussbaumstr. 10

Named as inventor:
Hitoshi Kinouchi,
Motoyasu Kunugiza,
Nishinomiya-shi, Hyogo-ken (Japan)

Claimed priority:

Japan February 22, 1963 (9111)

It is a process for the production of moldings by converting linear, predominantly Polyesters composed of aliphatic components with an excess of aliphatic or aromatic diisocyanates from 20 to 100% over that calculated on the end groups of the polyester Amount and offset of the extended polyesters produced in this way with at most that on the free isocyanate groups calculated amount of diamines or oxyamines known.

In this processes, the use of diamines or Oxydiamine must satisfy the condition that they react with the diisocyanate used in halbmolarer solution in methylene chloride at 4O ⁰ C until at least 25 to 30 seconds with separation of polyurea.

According to this known procedure, the diamine is used only as a chain extender, with z. B. o-dichlorobenzidine at a temperature of 135 ⁰ C is added. This results in an uneven distribution or dispersion of the diamine in the prepolymer; accordingly, the products obtained have a lower mechanical strength. According to this known procedure, the diamine can also be used together with a polyhydric alcohol, but only a cured product with poor physical properties is obtained.

709 679/595

3 4

It is also a process for the production of to lower their mixed melting point

Molded bodies by converting linear, pre-mixes ^{below 120 ° C.} As such low-melting

Zende crosslinking agents composed predominantly of aliphatic components are suitable compounds

Polyesters known in which a diisocyanate and or called the polyols, such as trimethylolpropane, butanediol

or a diamine with kinetically unevenly rea- 5 hexanetriol, tetramethylene glycol, 1,6-hexanediol or

Yawing amino or isocyanate groups used the adduct of propylene oxide (2 mol)

will. of bisphenol A, the amino alcohols such as 4-amino

According to this known procedure, a phenylethanol, monoethanolamine or diethanoi delay should be used the timing of the reaction and amine, triethanolamine, methylene-o-chloroaniline, according to Phedem an extended castability is aimed at io nylenediamine or tolylenediamine. The usage will. a composite crosslinking agent that,

The object of the invention is to create a process as described above for the production of homogeneous poly of two or more high-melting polyurethane elastomers with elimination of the prewetting agents or by mixing at least the disadvantages of the known working 15 a high-melting crosslinking agent and exhibit, a polyurethane elastomer of high at least one low-melting crosslinking quality and excellent mechanical strength means for lowering the mixed melting point is obtained under favorable working conditions. has been obtained below about 120 ⁰ C, represents a

The method according to the invention is thereby an indispensable condition in the method according to FIG

characterized in that one represents the crosslinking mixtures 20 invention. The type of crosslinking used

of high-melting polyamines with a medium and the proportion in which it is incorporated,

Melting point of the mixture of below 120 ⁰ C, can over a wide range according to the

consisting of at least two polyamines, of which for the polyurethane elastomer to be produced

at least one of a melting point can be varied from the intended use seen above.

120 ⁰ C possesses, is used. 25 In the practical implementation of the procedure

The process according to the invention can be carried out according to the invention can carry out the process up to the stage

any polyurethane prepolymers applied to the preparation of the prepolymer according to common

are carried out as a polyhydroxyl component, polyester, borrowed technical procedures.

Polyether or polyester amide and as isocyanate- The prepolymer is easily synthesized,

component polyisocyanate or polyisothiocyanate 30 by either a polyester, or polyether

include. a polyester amide with a two-fold equivalent

Suitable polyesters include polyesters by amount based on the reactive end groups Condensation of polyhydric alcohols, such as the aforementioned polyhydroxyl compound, Ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, from a polyisocyanate or a polyisothiol, 4-butylene glycol, diethylene glycol, trimethylolpropane, 35 cyanate at 80 to 110 ° C for 30 minutes to 2 hours Glycerol, hexanetriol or pentaerythritol, and converted into two. The co-basic described above Acids such as adipic acid, sebacic acid or set crosslinking agents according to the invention Maleic acid, synthesized, and polyesters, which are melted and added to the prepolymer, by polymerization with ring opening of z. B. After adding and thoroughly mixing the Decetenes or lactones, such as ε-caprolactone, include crosslinking agents in the prepolymer have been held. Suitable polyethers include stirring, pouring the mixture into molds, Polyethylene glycol, polypropylene glycol, polytetra- in which the shaping and heat treatment is demethylene glycol or their derivatives, in which a speaking usual working methods are carried out aromatic group has been introduced. Will be suitable.

Polyesteramides include those derived from the above said ethylene glycol, propylene glycol or borrowed working methods in the process according to the other polyhydric alcohols, the dibasic invention must be carried out, there is no need Acids and the amino alcohols, such as ethanolamine, consider the deterioration of the are made. Suitable polyisocyanates or poly-elastomers by the solvent, and consequently isothiocyanates are e.g. B. 1,5-naphthylene diisocyanate, it can be a uniform or uniform elastomer 4,4'-diphenylene diisocyanate or tolylene diisocyanate with excellent mechanical properties or the corresponding polyisothiocyanates. can be made effortlessly.

For use in the method according to the invention suitable crosslinking agents that explain the play in more detail.

sammengesetzte crosslinking agent according to the ER 55 will now be three modes of operation for Herfindung as the polyamines having a high melting position a prepolymer example described, point of above 120 ⁰ C of the individual components,

represent are o-dichlorobenzidine, o-dinitrobenzidine,. .

Dianisidine, 1,5-naphthylenediamine, 1,4-naphthylen- Procedure 1

diamine, toluidine, aminodiphenylamine or 4,4'-SuI- 6o (preparation of a prepolymer)
fonyldianiline. This can be done according to the procedure

the invention to apply by adding 100 parts of polyethylene glycol adipate (OH equivalent

at least two or more of any of them 1000) were heated to 90 ⁰ C. After adding

mixes to its melting point below 120 ⁰ C 18.3 parts of toluene diisocyanate was the mixture

to humiliate. These high-melting polyamines 65 are kept at 90 ^° C. with stirring. After 2 hours it was

can also use a prepolymer with an isocyanate equivalent in the process according to the invention

come to use by obtaining them with that of 1090, which is called prepolymer A.

known low melting point crosslinking agents.

Working method 2

(Preparation of a prepolymer)

After heating 100 parts of polytetramethylene glycol (OH equivalent 1010) at 9O ⁰ C 18.3 parts of tolylene diisocyanate was added, and the mixture was kept under stirring at 9O ⁰ C. After 2 hours, a prepolymer with an isocyanate equivalent of 1095, which was referred to as prepolymer B, was obtained.

Working method 3

(Preparation of prepolymer) After heating 100 parts of poly-e-caprolactone (OH equivalent of 1000) at 9O ⁰ C 18.3 parts of tolylene diisocyanate was added, and the mixture was maintained at 90 ⁰ C for one hour with stirring, ; the isocyanate equivalent of 1120 of a prepolymer was obtained. This was referred to as prepolymer C.

example 1

While 100 parts of prepolymer A were heated to 100 ° C., this was degassed at 5 mm Hg for 30 minutes. To this was then a mixture as a crosslinking agent (mixed melting point 95 ° C) of 3.1 parts of 1,5-naphthylenediamine (melting point 189 ° C) and 3.1 parts of o-dichlorobenzidine (melting point 136 ⁰ C), which had been prepared in advance , given. After stirring the mixture for 1 minute while defoaming, it was poured and molded.
100 parts of the

ίο defoamed prepolymer A above with 6.2 parts of only o-dichlorobenzidine were added, which formed after stirring for 30 seconds became.

The properties of these two types of elastomers are listed in Table I below.

The determination of the amount of output with the addition of

o-Dichlorobenzidine as a wetting agent could not be used because the sample was due to the high The melting point of the o-dichlorobenzidine was not uniform and showed great local differences. Even if the non-uniformity was disregarded and a test was made, it was abrasion obtained insignificant. This was also observed in the later examples.

Table I.

Crosslinking agents
(added amount)

Tensile strength kg cm ² elongation

Shore A hardness

Amount of abrasion, g
Williams Tester

1,5-naphthylenediamine (3.1 parts)
+ o-dichlorobenzidine (3.1 parts)

o-dichlorobenzidine (6.2 parts)

282 30.1 400
29

82 0.0123

because of the high melting point of the o-dichlorobenzidine, the uniformity was of the sample and local differences were very large

In the case of the elastomer produced using only o-dichlorobenzidine as a crosslinking agent local gelation took place. From the values in the table above it can be seen that the Properties thereof are so inferior that there is no comparison with that using the with composite crosslinking agent produced elastomers.

Example 2

100 parts of prepolymer B are heated to 100 ° C., whereupon it is at 5 mm Hg for 30 minutes was defoamed. For this purpose, a mixture of 3.1 parts of 1,5-naphthylenediamine was used as a crosslinking agent and 3.1 parts of o-dichlorobenzidine prepared in advance were added. after the The mixture was stirred for 2 minutes with defoaming, it was poured and molded.

As a control, 6.2 parts of o-dichlorobenzidine alone was added to 100 parts of the above defoamed prepolymer B was added, and after stirring the mixture for one minute, it became shaped.

The properties of the two kinds of elastomers thus obtained are as follows Table II given.

Table II

Crosslinking agents
(added amount)

Tensile strength kg cm ²

strain

Shore A hardness

Amount of abrasion, g
Williams Tester

1,5-naphthylenediamine (3.1 parts)
+ o-dichlorobenzidine (3.1 parts)

o-dichlorobenzidine (6.2 parts)

328 27.5

300
29

0.0123

because of the high melting point of the o-dichlorobenzidine, the uniformity was of the sample and local differences were very large

Example 3

After defoaming of 100 parts of prepolymer C for 30 minutes at 100 ⁰ C under 5 mm Hg, a mixture (mixed melting point 97 ° C) of 3.1 parts was added 4,4'-sulfonyldianiline (melting point 170 ⁰ C) and 3.1 Parts of o-dichlorobenzidine (melting point 136 ° C.), which had been prepared in advance by mixing in the melt, were added to the prepolymer. After stirring the mixture

it was poured and molded for one minute while defoaming.

Separately, 6.2 parts of o-dichlorobenzidine alone were added to 100 parts of the above, defoamed prepolymer was added, and after mixing for 30 seconds with stirring, the Mixture shaped. The properties of the two kinds of elastomers obtained in this way are given in Table III below.

Table III

Crosslinking agents
(added amount)

Tensile strength kg / cm ² elongation

/O

Shore A hardness

Amount of abrasion, g
Williams Tester

4,4'-sulfonyldianiline (3.1 parts)
+ o-dichlorobenzidine (3.1 parts)

o-dichlorobenzidine (6.2 parts)

298 19 400
42

0.0090
Melting point of

because of the high
o-dichlorobenzidine, the uniformity of the sample was poor and local differences were very large

In addition, found in a control where the crosslinking reaction carried out by adding a solution of o-dichlorobenzidine, dissolved in dimethylformamide, to prepolymer C and mixing it with it gelation occurred before solvent removal was complete.

Example 4

100 parts of the prepolymer B were defoamed for 10 minutes at 100 ⁰ C under 5 mm Hg. For this purpose, then one in advance by mixing in the melt blended mixture (mixed melting point 90 ⁰ C) of 3.1 parts of o-dichlorobenzidine (melting point 136 ° C) and 3.1 parts of toluidine (melting point 129 ° C) was added followed by 1 minute mixed for a long time with stirring; then the mixture was poured and molded. As a control, elastomers were prepared as described above, with the modification that 6.2 parts of o-dichlorobenzidine and toluidine were used independently of one another.

The properties of the three kinds of elastomers thus obtained are as follows Table IV shown.

Table IV

Crosslinking agents
(added amount)

Tensile strength kg / cm ² elongation

Shore A hardness

Amount of abrasion, g
Williams Tester

o-dichlorobenzidine (3.1 parts)
+ Toluidine (3.1 parts) ...

o-dichlorobenzidine (6.2 parts)
Toluidine (6.2 parts)

350 27.5

32

400
29

11

0.0110

because of the high melting point of the o-dichlorobenzidine, the uniformity was of the sample and local differences were very large

the same

Example 5

100 parts of prepolymer C were heated to 100 ⁰ C, whereby its defoaming was carried out for 30 minutes at 5 mm Hg. For this purpose, then a prepared in advance by mixing in the melt mixture (mixed melting point 90 to 98 ⁰ C) of 3.1 parts of o-dichlorobenzidine (melting point 136 ° C) and 3.1 parts dianisidine (melting point 137 ° C) was added, and after mixing for one minute, the mixture was poured and molded. As a control, the above procedure was repeated with the modification that 6.2 parts each of o-dichlorobenzidine and dianisidine were used independently of one another for the production of polyurethane elastomers.

The properties of these three types of elastomers are shown in Table V below.

Table V

10

Crosslinking agent tensile strength

(amount added) kg / cm ^s

o-dichlorobenzidine (3.1 parts)
+ Dianisidine (3.1 parts) 210

o-dichlorobenzidine (6.2 parts) 19

Dianisidine (6.2 parts) 50

Comparison 6

The procedure of Example 1 was repeated with the modification that 3.1 parts of 1,4-butanediol used in place of 3.1 parts of 1,5-naphthylenediamine became. An elastomer was produced in the process.

Comparison 7

The procedure of Example 2 was repeated with the modification that 3.1 parts of tetrahydrobisphenol A was used in place of 3.1 parts of 1,5-naphthylenediamine. It became an elastomer manufactured.

Comparison 8

The procedure of Example 3 was repeated with the modification that 3.1 parts of N, N'-bishydroxypropyltolylenediamine 4,4'-sulfonyldianiline was used in place of 3.1 parts. An elastomer was produced.

strain

0 / / 0

Shore A hardness

Amount of abrasion, g
Williams Tester

35

40

Comparison 9

The procedure of Example 4 was repeated with the modification that 3.1 parts of Ν, Ν'-bishydroxypropyltoluylenediamine instead of 3.1 parts of tolidine were used. An elastomer was produced.

Comparison 10

45

55

The procedure of Example 5 was repeated with the modification that 3.1 parts of 1,4-butanediol were used in place of 3.1 parts of dianizidine. An elastomer was produced.

The properties of the elastomers made in Comparisons 6-10 are shown below Table VI compiled (the values recorded in this table relating to the products according to Examples 1 to 5 are taken from Tables I to V).

205
42

72

69

0.0181

because of the high melting point of the o-dichlorobenzidine, the uniformity was of the sample and local differences were very large

the same

15th Table VI strain
% Shore A
hardness tensile strenght
kg / cm ² 400
1100
300
200
400
700
400
650
205
1000 82
55
88
78
79
70
80
75
69
50 _2O example 1
Comparison 6
Example 2
Comparison 7
Example 3
a ₅ comparison 8
Example 4
Comparison 9
Example 5
Comparison 10 282
80
328
60
298
200
350
205
210
70

30 also exist between the properties of the products produced according to the invention (Examples 1 to 5) and the products of the control or comparative tests 6 to 10, as is explained in greater detail below, substantial differences.

a) The ratio of the change in hardness of corresponding temperatures of those in the comparisons 6 up to 10 elastomers produced is 5 to 10 times as much as large as those of the elastomers prepared in Examples 1-5.

b) In general, the elastomers produced according to comparisons 6 to 10 have a poor rebound force or resilience, and they require several to several tens of times the length of time to return to the original state after the deformation.

Claims (1)

Claim: A process for the preparation of homogeneous polyurethane elastomers from polyesters, PoIyäthern or polyester amides and polyisocyanates or polyisothiocyanates after Vorpolymerisatverfahren by crosslinking the prepolymers with high melting polyamines, characterized in that for cross-linking blends of high melting polyamines having a melting point of the mixture of below 120 ⁰ C, consisting of at least two polyamines of which at least one has a melting point above 12O ⁰ C, is used. Considered publications:
German patent specifications No. 838 826, 953116. 709 679/595 10. 67 © Bundesdruckerei Berlin