CH624421A5 - One-component mixtures for the preparation of sealants, heat-sealing compositions or moulding compositions - Google Patents

Description

The invention is illustrated by the following examples:

Examples:

The polymer used in Examples 1 to 3 is an average structure polysulfide

HS (C2H4-0-CH2-0C2H4-SS) 23-C2H4-0-CH2-0-C2H4SH

with about 0.5% cross-linking.

It has an average molecular weight of 4000 and a viscosity at 27 ° C of 350-450 poises.

All quantities refer to parts by weight or percentages by weight.

example 1

A hardener mixture of 50 potassium permanganate, techn.

40 chlorinated paraffin 10 molecular sieve powder pasted.

100 g of this hardener paste were mixed with 1000 g of polysulfide polymer under vacuum. The mixture was divided. Some were stored locked in an aluminum tube. With the second part, a 15 x 15 x 50 mm joint between concrete prisms in accordance with DIN 18 540, sheet 2, was filled and stored open in a standard climate (23 ° C and 50% RH).

The open-stored mixture had thin skin after one hour and was fully hardened after 6 days.

The sealed mixture was still liquid after 10 days.

Example 2

100 g of the hardener paste described in Example 1 were mixed with 1000 g of polysulfide polymer and 10 g of dimethylaniline under vacuum.

The mixture was divided. Some were stored locked in an aluminum tube.

With the second part, a 15x 15x50 mm joint between concrete prisms was filled and stored open in a standard climate (23 ° C and 50% RH).

The open-stored mixture had thin skin after 45 minutes and was fully hardened after 5 days.

The sealed mixture was still liquid after 10 days.

Example 3

a) A basic mix-out

Polysulfide polymer 1000

Benzyl butyl phthalate 400

Calcined clay 200

Titanium dioxide 400

Molecular sieve puvler 10

Dimethylaniline 5 was made with 100 g of a paste

Potassium permanganate 50

Chlorinated paraffin 40

Molecular sieve powder 10

mixed under vacuum. The mixture was divided.

One part was sealed in a tube at 23 ° C, with the second part test specimens were made by placing the mixture in 15x 15x50 mm joints between two concrete prisms (15 x 25 x 80 mm). These test specimens were stored open in a standard climate (23 ° C and 50% rh). The mixture stored in this way had a thin skin after 90 min and was fully hardened after 5 days.

The sealed mixture was still sprayable after 10 days.

b) The basic mixture described in Example 3a was made with 50 g of a paste

Chlorinated paraffin 40

Molecular sieve powder 10

mixed and the mixture stored open at room temperature. After storage for 10 days, no skin formation or signs of hardening were observed on the mixture; d. H. that there is no crosslinking of the polymer without an oxidizing agent.

c) The test specimens described in Example 3a were stored for 14 days in a standard climate (23 ° C and 50% rh) and then tested:

Tensile force at 100% stretch: 10 N / cm2 reset after 5 hours of 100% stretch: 93%

Example 4

The product used in this example is an oligomeric polysulfide of average structure

HS- (C2H4.0-CH2.0-C2H4.SS) 8 • C2H4-O.CH2.O-C2H4.SH

with about 2% cross-linking. It has an average molecular weight of 1000 and a viscosity at 27 ° C of 7-12 P. 300 g of this oligomer were vacuumed out with a paste

5

10th

13

20th

25th

30th

35

40

45

50

55

bO

65

624421

4th

Potassium permanganate

Chlorinated paraffin

Molecular sieve powder

Aerosil 200 (= amorphous silica)

50 40 10 5

mixed under vacuum. The mixture was divided.

One part was stored open in a standard climate (23 ° C and 50% r.h.), the second part closed in a tube. The open-stored mixture formed a thin skin within one hour and was completely hardened by 15 mm after 6 days. The sealed sample was still liquid after this time.

Example 5

The polymer used in this example is a polymercaptan with the average structure e / o (c3h6o) 20_25ch2-ch-ch2sh oh l] 2--.

where R represents an aliphatic radical. The polymer has an average molecular weight of 6000 and a viscosity at 25 ° C of 60 P.

1000 g of this polymer were made with a paste

Potassium permanganate

Chlorinated paraffin

Molecular sieve powder mixed under vacuum.

20th

50 40 10

The mixture was divided. One part was stored open in a standard climate (23 ° C and 50% F.), the second part closed in a tube.

A thin skin formed on the openly stored mixture within 45 min and after 4 days the mass had hardened to a depth of 15 mm.

The sealed sample was still liquid after this time.

Claims (3)

624421 z PATENT CLAIMS there is a possibility that 1 800 982 and DT-OS 2 062 259 eliminated by continuing to harden there through 65. Chemical reaction of the activator for Zn02 hardening is of particular advantage here, as is the rapid det, which enables a chain reaction. However, the adhesive free time of about one hour and the independent one are activated by carboxylic acid (acetic acid) and further hardening of the mixtures. In addition, single grain 1. One-component mixtures for the production of tightness that the polymer degrades in dry heat due to the acid during the aging process and in the sealing and sealing or molding compounds. In addition, the condition can be stored in a stable manner and the chalk, which is important and inexpensive under the influence of moist fillers, cannot be used, and can be hardened in the presence of oxidizing agents, on which 5 da CO2 is formed. Basis of liquid polymers or mixtures of monomers. Also in DT-OS 2 107 971 a one-component system, oligomeric and polymeric compounds with end-end systems with zinc peroxide as hardener is described, which according to Kongen mercapto groups, characterized in that they were Cycle with moisture in a chain reaction independently of serum-free potassium permanganate as a latent hardener that can continue to harden. However, the method has the disadvantage of containing capto-terminal compounds in the anhydrous state 10 that the masses are sticky for a relatively long time. the process does not produce any permanent mixtures 2. One-component mixtures according to claim 1, thereby producing. characterized that they optionally plasticizers, pigments, a fairly easy to manufacture, relatively quick skin Contain fillers, thixotropic and drying agents. and hardening one-component system 3. Process for the preparation of one-component 15 one with the sodium chromate hardening (DT-OS 2 363 856). Mixtures according to one of claims 1 to 2, characterized in that the toxic properties of the chromium are disadvantageous here in that both the mercapto-terminal mats, particularly since during the curing period of the compounds and the potassium permanganate, are left traces of sodium chromate by rain All the water can be washed out of the top mixes by heating or adding a surface of the mass. Desiccant withdrawn. It is therefore an object of the present invention to produce nontoxic, storage-stable, thixotropic mixtures which contain the polymer and the oxidizing agent at the same time and which form a tack-free skin quickly on contact with moisture and relatively quickly become rubber-elastic 25 Cure the mass. One-component mixtures for the preparation of sealing compounds. The invention therefore relates to one-component mixtures of sealing, sealing or molding compositions based on liquid, for the production of sealing and sealing or molding polymers or mixtures of monomeric, oligomeric compositions are stable in storage in the dry state and those under ren and polymeric compounds with terminal mercapto exposure to moisture in the presence of oxidizing groups. 30 t harden, based on liquid polymers or Oligomers and polymers with mercapto end groups, the mixtures of monomeric, oligomeric and polymeric Versich with oxidizing agents such as Pb02, MnOî, chromate, cumene bonds with terminal mercapto groups, thereby hydroperoxide u. a. Oxi-marked for rubber-like elastic materials, that they allow anhydrous potassium permanganate to be used, are often used for the production of sealing latent hardeners and the mercapto-terminal connections and sealing or molding compounds. 35 included in anhydrous condition. Such materials usually come in two components. Surprisingly, it has now been found that systems for use; d. H. the connection with end-stable mixtures of mercapto-terminated polymers and permanent mercapto groups on the one hand and the Oxidationsmit- potassium permanganate can be made if both the tel are packaged and stored separately and polymer and the permanganate before mixing all- mixed together shortly before processing. Withdrawal from greenish water. In the event of contact with atmospheric moisture, simplified and safer application, these mixtures want a tack-free skin to be used by more and more processors in 60-120 min. One-component masses and the hardening takes place within a few days. zen, d. H. Storage-stable mixtures which contain the polymer and the oxi. The curing of mercapto-terminated polymers with dating agent at the same time and which has been known for many years in the processing of potassium permanganate, contact with air humidity at room temperature 45 has so far only been used in two-component systems polymerize. turns. There are currently three groups of technically usable monomers. Normally, liquid polysulfide polymer components systems are known, hardening with calcium per 0.1-0.2% and potassium permanganate about 0.3% water. Already oxide, with zinc oxide or peroxide and with sodium chromate. this small amount of moisture is sufficient for immediate In the calcium peroxide system, which is described in US Pat. No. 3,349,047, when the mercapto end groups are oxidized when the two are mixed, two components form on contact with the atmospheric moisture. Only after a complete drying of the skin quickly. The further curing takes place, however, both substances can produce a mixture that is stable in storage, very slowly, so that appropriate mixtures for use contact with the air humidity necessitate water purposes, in which the seal would soon be exposed to the surface of the mixture, followed by the oxide - is not usable. The same applies to hardening crosslinking of the SH end groups, so that systems with zinc oxide or zinc peroxide, such as those formed in US-PS, form tack-free skin very quickly. The seven-valent man-3 275 579, US-PS 3 402155 and US-PS 3 499 864 describes the permanganate to reduced to tetravalent and which are - an activation of the oxidizing agent takes place through the originally violet color of the mixture disappears. An amine which is further reduced from an amine-loaded molecular sieve by what part of the tetravalent manganese is displaced to the water. Since many molecules of water are needed, 60 divalent. As a result, at least partially, per person to displace one molecule of amine from molecular sieve, manganation two and a half 'molecules of water are formed, which, like these mixtures, can activate further permanganate if there is a lot of moisture from outside. Thus instructed. there is a chain reaction so that when the mixture This disadvantage is independent of the methods according to DT-OS that has come into contact with moisture 3rd 624421 Component compositions according to the present invention, the good properties known from manganese-hardened two-component compositions with regard to UV resistance and high resilience with relatively low tensile stress values. Either the pure compound or a commercially available product with a lower degree of purity can be used as potassium permanganate. However, it must be finely powdered and dried before use, be it that it is heated above 100 ° C or with small amounts of a desiccant, such as. B. molecular sieve powder is mixed. The amount of potassium permanganate required for curing depends on the SH equivalent of the polymer to be oxidized. In any case, it must be ensured that all thiol groups can be oxidized. It is therefore expedient to use the stoichiometrically necessary amount plus an approximately 10% excess, so that generally 2-15% KMnOt, based on the liquid mercapto-terminal polymer, is sufficient. The inventive method is applicable to all polymers or mixtures of monomeric, oligomeric and polymeric compounds with terminal mercapto groups, such as. B. on polysulfide polymers, polymeric thioethers and the like. An example of a monomeric compound with only one SH group is 2-mercaptoethanol, which is often added to the polymers as a so-called chain stopper in order to achieve greater flexibility in the cured end product. The curing rate can be increased both by adding amines, such as. As dimethylaniline, trioctylamine, hexamethylenetetramine or triethylamine, as well as by adding small amounts in the rubber industry of conventional vulcanization accelerators, such as. B. tetramethylthiur amide sulfide or Zn-N-dimethyldithiocarbamate can be increased. To the mixture of mercapto-terminated polymer, potassium permanganate and optionally accelerator can optionally plasticizers, such as phthalates or chlorinated hydrocarbons, as well as pigments, fillers, thixotropic agents and drying agents, such as. B. titanium dioxide, calcium carbonate, clay, carbon black, calcium oxide, molecular sieve powder u. a. can be added.