DE2606559A1 - Abrasion-resistant multi-layer polyurethane lacquer coating - from polyester mixt., esp. for fibre-reinforced synthetic blades in turbo-machines - Google Patents

Abstract

A protective coating for articles subjected to abrasion consists of the reaction prod. prepd. in absence of an accelerator, from (a) polyethylene glycol adipate and a polyester from glycerin, adipic acid with phthalic acid, and (b) an isocyanate resin from 3 moles toluylene diisocyanate and 1 mole trimethylolpropane. The coating is applied in several pref. 3 layers with total thickness 0.1-1 mm (0.1-0.5 mm) with the elasticity increasing towards the outer layer. The ratio OH: NCO is 1: 0.6-1.8. The coating is esp. used on blades for turbo-machines, formed of several layers of fibre-reinforced synthetic matrices. Abrasion-resistance is considerably better than with known polyurethane la cquers.

Description

ßSHiizer mechanical engineering

Sssriin plant

129

Surface protection layer for components at risk of abrasion, in particular blades for turbo machines, and processes for their production

The invention relates to a surface protection layer for components at risk of abrasion, in particular for a plurality of components layers of a fiber material bound with a synthetic resin matrix existing blades for turbomachinery, and a method for their manufacture.

It has been shown that in particular made of fiber-reinforced Plastic penalty certificate due to the dusty and intake air containing sand are subject to strong abrasion, which considerably reduces the service life. It will therefore sought to extend the service life of such components at risk of abrasion by applying a To achieve surface protective layer.

It is already known that a certain amount of surface protection can be achieved by applying polyurethane paints. Those formed by applying common polyurethane varnishes However, protective layers have so far been able to with regard to their use, particularly when used on compressor blades Abrasion resistance not yet satisfactory.

The invention is based on the object of providing a polymeric surface protection layer for components at risk of abrasion, especially for those made of fiber-reinforced plastic To create blades for turbo machinery, which has a high abrasion resistance.

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According to the invention this is achieved in that the surface protection layer made of a graduated, increasingly elastic, multi-layer, preferably three-layer, Polyurethane application with a total layer thickness of 0.1 to 1.0 mm, preferably 0.1 to 0.5 mm, exists whose first order is an OH-ITCO ratio in Starting mixture between 1: 0.6 and 1: 0.9 and its last application an OH-FCO ratio in the starting mixture between 1: 1.4 and 1: 1.8.

The surface protection layer is produced duroh a successive application of these individual layers, after each layer has been applied, pre-drying is carried out at low temperature and intermediate curing at 80 ° C is done during one hour. The entire surface protective layer is then cured at 150 over a period of up to three days or by curing for only ten hours at 150 ° G followed by four weeks Storage at room temperature,

The evaluation of the abrasion behavior of the protective surface layer was carried out by measurement by weighing the abrasion loss. In the test facility, the coated test specimen was irradiated with corundum blasting with a grain diameter of 0.2 mm in an air flow at a speed of 250 m / s. The calculated bombardment rate was 3.34 g / s ₀ cm _β. The protective layer according to the invention has an abrasion loss that is about a power of ten lower than the known protective layers. In compressor blades coated according to the invention, this very favorable abrasion behavior made their operational use possible.

The invention is to be explained in more detail below using an exemplary embodiment.

The multi-layer surface protection layer with outwardly increasing elasticity consists of a base coat and a top coat _{or the like}

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The base coat is 0.15 equivalents (198.3 g) of a polyethylene glycol adipate (OH number 42) and 0.1 equivalents (19.45 g) of a polyester made from glycerol, adipic acid and phthalic acid (OH number 288) , with equal parts of a Lösangsmittelgemisches consisting of 37.5 ew * fo methyl ethyl ketone, 12.5 wt. fo butyl ac et at, 37.5 wt. fo ethylglycol acetate and 12.5 wt. # toluene, mixed so that the solution Contains 50 fo solid. 0.2 equivalents (75.4 g) of an isocyanate resin (11.2 fo HCO content), consisting of 3 moles of tolylene diisocyanate and 1 mole of trimethylolpropane (75 followings in ethyl acetate), are diluted with the abovementioned solvent mixture to give a 50 followings solution and stirred with the above-mentioned polyester. After the components have been thoroughly mixed, this base coat stands for about an hour to pre-react.

0.3 equivalents (396.6 g) of the polyethylene glycol adipate and 0.2 equivalents (38.9 g) of the functional polyester resin made from glycerol, adipic acid and phthalic acid (OH number 288) with the above-mentioned solvent mixture are used as topcoat mixed to a 50 # solution. 0.75 equivalents (282 g) of the isocyanate resin (ITCO content 11.1 fo) are added as a 50 # solution to this mixture. The topcoat is also left to stand for an hour _{or similar}

Primer and topcoat are applied to the corresponding component, for example the blade of a compressor blade, using known application methods for paints. Each of the layers created in this way is predried at room temperature and cured for one hour ^{at a temperature of 80 ° C.}

After applying the last top coat in compliance Using the method described above, the entire surface protective layer is cured in one

609837/0995

Temperature of 150 ° C in a period up to three days protective layer »The surfaces also receives its favorable abrasion properties with only a ten-hour curing at a temperature of 15O ⁰ C and subsequent storage at room temperature over a period of four weeks ago ·

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Claims (2)

P at ent claims Surface protection layer for components at risk of abrasion, especially for one with one layer made up of several layers Resin matrix bonded fiber material existing Blades for turbo machines, made of polyurethane by converting an OH-terminated bifunctional and / or trifunctional part Polyester and an isocyanate resin, characterized in that that the surface protective layer consists of a graduated, to the outside increasingly elastic, multi-layer, preferably three-layer, polyurethane application with a total layer thickness of 0.1 to 1.0 mm, preferably 0.1 to 0.5 mm, the first Apply an OH-KGO ratio in the starting mixture between 1: 0.6 and 1 ι 0.9 and the last order an OH-NCO ratio in the starting mixture between 1: 1.4 and 1: 1.8. 2. A method for producing a surface protective layer according to claim 1, characterized in that successively in several layers, preferably in three layers, with a total layer thickness of 0.1 to 1.0 mm, preferably 0.1 to 0.5 mm , Polyurethane resin mixtures are applied, the compositions of which have an OH-OTGO ratio between 1: 0.6 and 1: 0.9 for the first application and an OH-ETCO ratio between 1: 1.4 and 1: 1 for the last application have 8, and NaOH the application of each layer, a Vörtrocknung at room temperature and an intermediate curing at 80 ° C for one hour is performed, and the curing of the entire surface protective layer at 150 ⁰ C over a period bj at about three days, or by only ten-hour curing 150 ⁰ G with subsequent four-week storage at room temperature takes place _o 609837/0995