FI82067B - Composition for coating, sealing and protection purposes - Google Patents

Description

1 82067

The present invention relates to a composition for coating, sealing and protective purposes, to a process for its preparation and to a process for its application.

It is an object of the present invention to provide a composition which can be used as a surface coating which is susceptible to corrosion and mechanical effects; as a sealant for water and other liquids in pipe joints, roofs, as a joint sealant for ceramic bricks, metal sheets, etc., and which mixture is highly resistant to mechanical wear and the effects of chemicals, including water.

SE-B-399915 describes a corrosion-resistant coating composition specifically for rust protection outside vehicle bodies, which composition consists of a polyurethane polymer, waste rubber, anhydrous coal tar and a zeolite desiccant. This mixture generally serves its purpose, but it has some disadvantages due to the strong odor of coal tar, which prevents its use in confined spaces and also leads to the need for well-ventilated spaces for application. Furthermore, coal tar results in the coating acquiring a black color, which may often not be relevant, but just as often is not acceptable, but instead requires a product dyed with the selected color pigment. In addition to these disadvantages, which are to some extent cosmetic in nature, even greater durability, duration of action of chemicals, especially in an alkaline environment, and temperature stability are often required.

2 82067

It has now surprisingly proved possible to overcome these problems with the present invention, which is characterized in that the mixture contains rubber having a particle size of up to 0.4 mm and present in an amount of up to 50% by weight, and an isocyanate-curable polyhydroxy type 40-55% by weight of the base polymer, 18-30% by weight of the polymer-curable isocyanate and 1-5% by weight of the aliphatic polyether teriglycol.

Other features are set forth in the appended claims.

The curable prepolymer is preferably an isocyanate-curable polyurethane (Desmodur hardener, Desmophen 1150 prepolymer), but isocyanate-curable epoxy polymers can also be used.

Suitable polymeric binders that can be cured with active isocyanate curing agents include various polyols and polyester base resins having a molecular weight of 200 or more. Other polymeric materials include epoxy resins that are primarily dissolved in a ketone or glycol ether and then cured using an active isocyanate hardener (e.g., Desmodur) or an active amino group hardener. Suitable epoxy resins have a molecular weight of 1000 or more.

The polyol used may be either a polyester such as Desmophen 1150 or the like and / or an aliphatic glycol or more simply ethylene glycol, diethylene glycol and triethylene glycol.

All types of rubber can be used as rubber material, such as waste rubber, waste rubber tires, raw rubber and other rubber grades.

Thus, it has been found that 20-40% by weight of rubber powder, suitably waste rubber with a particle size <0.4 mm and preferably 0.05-0.2 mm, 40-50% by weight of base polymer, 1-5% by weight of

II

3,82067% aliphatic polyether glycol base resin and 18-25% by weight iaocyanate hardener provide excellent products within the scope of this invention. Thus, these alloys have a very high elasticity and wear resistance in the cured state. In the case where the polyester base resin contains moisture, a desiccant, alternatively active alumina or basic aluminum foil and.

Example 1 40 parts by weight of waste rubber having a particle size of 0.1-0.2 mm were thoroughly mixed with a mixture of 40 parts by weight of Desmophen 1150 and 2 parts by weight of polyether glycol (triethylene glycol). To this common mixture was then added 18 parts by weight of active iaocyanate hardener (Desmodur) to cure the polymers. The prepared mixture was used to prepare various test coatings for testing.

The above product <A> of Example 1 was tested and compared with the product <B) of the example of patent SE-B-399915 in terms of wear resistance, heat resistance, steel adhesion and chemical resistance.

Kulutuekestoisuus

Plates coated with the above coatings were treated for 5 days (120 h) in a barrel mixer along with 200 g of stones. The elapsed material volume was then measured in units e.g.

3 A = 19 mm 3 B = 105 mm

Cylindrical specimens of the corresponding product were forced over 2 abrasive cloths of 60 particles / cm at a pressure of 5 N and a distance of 20 m, after which the discharged volume was determined.

3 4 82067 A = 145 mm 3 B = 470 mm Heat resistance

The plates with the coatings applied to them were hung for 2 days (48 h) at different temperatures, the samples / plates were then adjusted at ambient temperature (20 ° C) and then visually inspected.

A = withstands 150 ° C B = withstands 80 ° C

Adhesion to steel

Coatings on steel were tested for adhesion to determine adhesion.

A = withstands 4.0 MPa before rupture B = withstands 0.8 MPa before rupture

Chemical resistance

Test coatings on similar products were exposed to different oils, allowing Sample B to stain all of these liquids, while Sample A did not cause staining.

When tested in an acidic aqueous environment (HCl 30%, ΗΝ0 10%, H SO 10% or CH C00H 50%) the durability is approximately the same. In an alkaline aqueous environment (NaOH or NH 4 OH), sample A is better.

The water vapor permeability is lower in sample A than in sample B.

Application Sample A can be applied in thicker layers (2.5-3 mm) vertically depending on sample 1 than sample B, which can be applied only in a 1.5 mm thick layer.

Il 5 82067

In the preparation of the mixture in question, the product should preferably be placed under reduced pressure, whereby in particular the wear resistance and the chemical resistance are further improved. In addition, aging resistance, moisture resistance and adhesion strength are improved. The pressure in the vacuum stage to eliminate air should be 80 kPa, but in the case of very viscous mixtures it can be further reduced to 50-60 kPa.

The application of the mixture can be carried out in various ways, such as by simple hand painting, by mechanical painting and by high-pressure spraying. For high-pressure spraying, it is suitable to use a modified conventional two-component type high-pressure spraying device in which the mixture without hardener and hardener is brought together before the outlet of the mixing tube (s e-mixer) and passed through a high-pressure hose 1. The pressure of the mixture should be so high as to obtain a well-distributed (sprayed) spray mass which, with the viscosities of the mixtures normally present, gives 16-20 MPa at a pressure and a temperature of 40 ° C, preferably 40-80 ° C and more preferably 45-60 ° C. :in.

Normally, the viscosity of the mixture is such that the high pressure pump as such fails to suck the mixture into the apparatus at normal temperature. Thus, the pressure plate is successfully placed in a high pressure injector, which plate fits exactly into the vessel in which the mixture is prepared, after which the pressure plate is pressed down into the manufacturing vessel either mechanically, pneumatically or hydraulically so that the mixture is pressed upwards into the high pressure injector.

To improve the curing of the above mixture, the curing reaction accelerator may be added in an amount of 0.1 to 0.5% by weight. Examples of such accelerators are dibutyl distanediol diurate or similar lead compounds.

6 82067

To reduce the risk of fire, a flame retardant such as a phosphite compound may be added to the mixture in an amount of 5 to 15% by weight. The Nowgard V-4 is an example of a retarder.

The mixture can also be made thixotropic by the addition of a suitable gelling agent.

Il

Claims (10)

A mixture for coating, filling, bonding and protection comprising an isocyanate-curable polymer and a rubber, characterized in that it consists of rubber having a particle size of not more than 0.4 mm and present in an amount of 20 to 50% by weight, and an isocyanate-curable base polymer present in an amount of 40 to 55% by weight, a polymer-curable isocyanate in an amount of 18 to 30% by weight, and an aliphatic polyether glycol in an amount of 1 to 5% by weight, which the components after curing said base polymer are the resilient and adhesive part of the mixture. Mixture according to Claim 1, characterized in that the base polymer consists of a polyester-type polymer mixed with a polyether glycol-type base polymer. Mixture according to Claim 1, characterized in that the rubber has a particle size of 0.01 to 0.2 mm. Mixture according to Claim 1, characterized in that the base polymer is an isocyanate-curable polyepoxide. Mixture according to Claim 1, characterized in that the base polymer is polyurethane. Mixture according to Claim 1, characterized in that the mixture further contains a zeolite desiccant, active alumina and / or aluminosilicate. Mixture according to Claims 1 to 6, characterized in that the mixture further contains a coloring pigment. 7 82067 Process for preparing a mixture according to Claims 1 to 7, characterized in that the rubber powder with a particle size of at most 0.4 mm is provided with a curable p-β 82067 base polymer, an aliphatic polyether glycol, and optionally a coloring pigment, after which the mixture is reduced to at least 90 kPa. Method according to Claim 8, characterized in that the vacuum is 80 kPa, but preferably not less than 50 kPa. A method for applying a mixture according to claims 1 to 7 by means of a high pressure, characterized in that the mixture without hardener is sucked with the hardener into a high-pressure pump modified with a pressure plate; that the pressure plate is placed in a high pressure pump, which pressure plate is pressed down into the mixture and the hardener to press them up into the pump; that the mixture is heated to more than 40 ° C in connection with a pump to obtain a fine mixture injection pattern with a mixture pressure of 15 MPa or more. ti β 82067