HU209841B - 2-Coat paint system for strippable, temporary coatings, esp. for cars - has first layer of film-forming monomers or polymers, adhesion-reducing cpds. and plasticiser, and sec. layer of crosslinkable polymers etc. - Google Patents

Abstract

A paint system (I) comprises (A) a compsn. for a first layer, in the form of a sprayable, homogeneous soln. or dispersion, contg. (a) linear polymer(s) and/or monomers and/or oligomers and/or synthetic resins as film-formers (II), (b) up to 50 wt.% alkali and/or alkaline earth salt of (un)satd. 2-24C aliphatic acid and/or synthetic satd. 6-18C aliphatic monocarboxylic acid and/or alkyd resins obtd. from these cpds., as adhesion-reducing agent, and (c) 0-100 wt.% plasticiser (w.r.t. amt. of polymer from II), and (B) a compsn. for a second layer, contg. crosslinkable polymers and/or oligomers and/or monomers and/or synthetic resins. Compsn. (A) has dry substance content (DS) = up to 25 wt.% (the rest being inert organic solvent) and (II) consists of linear polymer(s), or up to 50 wt.% with linear polymers of mol. wt. 20,000-500,000 and monomers and/or oligomers with mol. wt. 100-5000 and/or synthetic resins with mol. wt. 500-10,000, or up to 100 wt.% with monomers and/or oligomers of mol. wt. 100-200 and/or synthetic resins with mol. wt. 500-2000. USE/ADVANTAGE - (I) is useful for providing articles, esp. motor vehicles, with a temporary, scratch-resistant, corrosion-proof coating (for transport, etc.) which can be easily stripped off by hand when required without damaging the original surface, and which can be disposed of without adverse environmental effects.

Description

FIELD OF THE INVENTION The present invention relates to the production of a film-like release liner on a varnished substrate, particularly on a freshly varnished vehicle surface.

Vehicle manufacturers usually apply an exterior protective coating to the lacquer coating of new vehicles, which can be easily and quickly removed from the vehicle with hot water or steam. These transition barrier layers are predominantly low softening point materials made from natural and / or synthetic resins and / or waxes which can be removed from the surface by hot water or steam at temperatures above 60-80 ° C in the form of small particles, droplets or aqueous suspensions. An essential requirement for temporary protective coating materials is that they do not attack the original enamel layer of the vehicle, the rubber and chrome surfaces, and provide a temporary mechanical protection of the surface so that after the removal of the protective material, the appearance of the vehicle corresponds to its new condition.

Polymer films that are only soluble in warm water or alkaline water are also used to temporarily protect vehicle lacquer coatings. These include polyvinyl alcohols having a high degree of hydrolysis, polyacrylic acids, polymers containing various vinyl carboxylic acids.

These substances cause significant amounts of poorly decomposing organic matter in the wastewater and the environment, which makes them increasingly difficult to protect from the environment.

Ullmann Encyclopedia of Chemistry Volume 19 4th Edition 386-387. pages and the Encyclopedia of Polymer Sci. and Techn. 14. Polyvinyl butyral dispersions containing a plasticizer according to page 233 are used as strip coating for valuable articles and products against corrosion.

Coatings made of polyvinyl butyral dispersions do not mechanically exert sufficient protection against vehicle surfaces, and it is cumbersome and costly to produce such coatings.

U.S. Patent No. 1,960,817 discloses a peelable, water-soluble protective coating for metallic objects comprising polyethylene oxide, polyvinyl alcohol, carboxymethylcellulose and / or hydroxymethylcellulose. The organic matter load in wastewater is also a significant problem in this process.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a protective coating for vehicle lacquer, which is easily removable by hand and is environmentally friendly, adjustable adhesion of the coating to the lacquer surface, and provides the outer layer with sufficient mechanical strength to protect the lacquered metal surface during transport and storage.

A further object of the present invention was to provide a coating with good weather resistance and optional adhesive strength using environmentally friendly film-forming agents and solvents which are non-toxic, alone or after biological or thermal degradation, and which do not damage the lacquered surface to be protected.

The invention thus relates to a process for producing a film-like peelable protective film coating having a thickness of 10 to 100 µm on a freshly lacquered vehicle surface comprising a rubber and / or plastic surface such that a monomer and / or oligomer polymerizable as an inner layer in homogeneous solvent solution or dispersion film-forming agents optionally sprayed with a lacquer composition containing additives which are linearly formed from a polymer having a molecular weight of more than 100,000 average molecular weights, preferably nitrocellulose, ethylcellulose, polyvinyl ester, polyvinyl acetate and vinyl esters and polyvinyl acetals and polyvinyl acetals, A viscosity of 5000 mPas and a boiling point of mono, di- or polyvinyl compounds having a boiling point higher than 100 ° C, preferably isopropyl methacrylate, butyl methacrylate, (poly) propylene glycol; methacrylate, vinyl carboxylic acid esters of polyhydric alcohols, preferably dipropylene glycol dimethacrylate, trimethylolpropane triacrylate, polypropylene glycol dimethacrylate, and / or polyesters and / or polyesters with a viscosity of up to 50,000 mPas and / or from 0.1 to 50% by weight, based on the film-forming component, of an alkali metal or alkaline earth metal salt of C ₂ -C ₂₄ aliphatic saturated or unsaturated fatty acids and / or C ₆ C ₁₈ aliphatic, saturated synthetic monocarboxylic acid and / or from alkyd resin (s) and / or C ₆ -C ₁₂ aliphatic primary alcohol (s) made from bbi products and dicarboxylic acids, and lacquer softeners having a boiling point greater than 200 ° C at an atmospheric pressure of 0-100% by weight and 050% by volume with a boiling point higher than 50 ° C and a flash point higher than 21 'C consisting of acrylic solvents and sprayed onto the composition as an overcoat consisting of 5-8 Erichsen (mm) and 10-60 Persoz (mm) hardened modified alkyd resin, aliphatic isocyanate-crosslinked acrylic resin or acrylic resin ester at a temperature of 50-90 ° C for 10 minutes. It is cured for 8 hours by heat treatment.

In accordance with the present invention, a film former is first applied to form a film coating which is adherent in a limited but highly controllable manner, and then a vehicle varnish or an enamel is applied which is applied or applied. adheres to the primer coat so that, if necessary, they can be completely stripped away from the original vehicle lacquer surface when needed. The peeled foil can be folded into a small volume and then stored or disposed of with normal municipal waste. destroyed. Therefore, we use only film-makers that are either biological or non-biological, for film production. they are non-toxic during thermal decomposition, ie not dangerous to the environment.

The release liner according to the present invention is an in situ self-adhesive film on a conventional vehicle lacquer layer which is in direct contact with the metal surface.

HU 209 841 A is located. You must have an outer layer of sufficient tensile strength and thickness for complete removal. To this is attached an elastic, dimensioned adhesive layer on the inside. The outer and inner layers are chemically bonded to polymer chains so that they cannot separate from each other during the peeling operation, or under external, rough mechanical or thermal stress. The peeling may occur only at the interface of the original lacquer and the protective film applied thereto.

For the thicker outer coat of sufficiently high tensile strength, commercially available automotive enamels are generally suitable. The lower, dimensionally adherent film is formed by film formers which, with external or internal plasticizers, are elastic and contain anti-adhesive agents.

A large group of controllable adhesive film-forming components are linear polymers which are soluble in inactive solvents, such as aliphatic esters, ketones, alcohols, ethers and mixtures thereof, which are commonly used in vehicle varnishes. In particular, copolymers of nitrocelluloses, ethylcelluloses, polyvinyl esters, polyvinyl acetate, polyacrylic esters, vinyl esters and acrylic esters are advantageously used.

Another group of film-forming components are compounds that form polymers after spraying by "in situ" polymerization. In other words, starting from low viscosity liquid monomers and / or vinyl oligomers, low or medium viscosity (η = max 50,000 mPa.s) resins, the film forming layer is formed by radical polymerization and / or polyaddition and / or polycondensation.

The monomeric and / or oligomeric and / or polymeric film formers are selected to solubilize each other or to form homogeneous solutions with conventional lacquer solvents.

From this homogeneous solution, during spraying and subsequent drying, a special film is formed which has a limited adhesive capacity (peeling force min. 0.5, max. 10.0 N / cm, preferably 1-6.0 N / cm), Elastic material having a Tg (glass transition temperature) of less than 20 ° C, preferably less than 10 ° C, with a tensile elongation greater than 150%.

The adhesion of the release liner according to the invention, i.e. the adhesion at the interface of the vehicle lacquer and the release liner, can be controlled by appropriately selecting the film forming components of the inner layer and by selecting the most suitable plasticizer from the plurality of plasticizers.

If one or more linear polymers are used in the film production, a solution with a dry solids content of up to 15-25% by weight will be used. Only high average molecular weight (M _n preferably> 100,000) polymers provide good film-forming properties. They can only be sprayed sufficiently from a solution having a concentration of 5-10% by weight. Liquid film thickness can be applied in one spraying operation up to max. Between 3Q and 60pm. So the dry film thickness is no more than that

1.5-6 pm. When multiple layers of liquid are sprayed, the outer layer of the previously applied film is partially dissolved in the solvent mixture, i.e., the macromolecules of the two layers diffuse to each other, resulting in a film approximately twice as thick as the one applied.

If the film-forming solution contains low or medium monomeric and / or synthetic resin components in addition to or instead of the linear polymer (s), the dry matter content may be increased. In this case, the thickness of the film that can be applied in one operation can be considerably larger and the amount of environmentally polluting inactive solvents to be evaporated is considerably smaller.

Among the vinyl monomers, materials with lower vapor density, boiling point greater than 100 ° C and high LD ₅₀ (LD ₅₀ > 5.0 g / kg), such as isopropyl methacrylate, butyl methacrylate, methacrylic acid and ( monoesters of poly) propylene glycols.

With the help of adi or polyvinyl compounds, the resulting material can be converted to a cross-linked insoluble polymer, which may be advantageous for example in terms of heat resistance. Preferred di- or polyvinyl compounds are esters of polyhydric alcohols with vinyl carboxylic acids, such as dipropylene glycol dimethacrylate, trimethylolpropane triacrylate, polypropylene glycol dimethacrylates.

The monomers and monomer mixtures in question can be converted into linear or crosslinked polymers using known radical initiators and redox systems.

Occasionally, photoinitiation may be useful, in which case known photoinitiators or photoactivators should be added to the monomers.

Synthetic resins crosslinked at room temperature or higher by radical or ionic polymerization, polycondensation, or polyaddition mechanism can be advantageously used in the film coatings of the present invention.

Of the conventional lacquer resins, saturated polyesters, saturated polyesters modified with natural resins and / or oils and / or epoxy resins, aliphatic polyurethane prepolymers, aliphatic isocyanates containing other groups (such as biuret, allophanate, uretdione, isocyanurate, etc.) are particularly preferred. aliphatic, cycloaliphatic and aromatic epoxy resins with crosslinkers. Of the above resins, especially low and medium viscosities (η = max. 50,000 mPa.s) are highlighted. These are generally well or sufficiently soluble in the solvent mixture required for film formation.

Preparing peelable reduce adhesion films are particularly useful for the various carbon atoms, more particularly C ₂ -C ₂₄ aliphatic monocarboxylic acids, Na, K and Ca salts and / or C ₆ -C _Ig aliphatic saturated synthetic monocarboxylic acids and / or made using the latter alkyd resins and / or C ₆ -C ₁₂ aliphatic primary alcohols. The amount thereof is selected from 0.150 wt%, preferably from 1 to 201 wt%, based on the weight of the dry inner film.

HU 209 841 A

The solvents used have a boiling point higher than 50 ° C but lower than 200 ° C. It is preferred to use aliphatic and cycloaliphatic mono- and polyhydric alcohols of inorganic and organic acids, aliphatic and cycloaliphatic ketones, ethers, ether alcohols and alcohols being preferred. In addition, there may be occasionally aliphatic, cycloaliphatic, aromatic hydrocarbons and / or their halogenated derivatives which are less hazardous to the environment.

In addition to the inactive solvents, one or more plasticizers having a boiling point greater than 200 ° C may be added to the film forming fluid.

These are predominantly esters and / or oligo esters of inorganic and organic acids. Epoxidated derivatives of certain vegetable oils and polyester resins, inactive or reactive only above 100 ° C, may also be used as plasticizers in the inner film layer.

In addition to film-forming components and inactive solvents, the film-forming fluid may contain pigments, dyes, light and heat stabilizers, antistatic agents known in the art, as required. The particulate solids (e.g., pigments) have a particle size of not more than 30 µm, preferably less than 10 µm.

Example I

A homogeneous solution is first prepared in a known varnish equipment and method by the following formula:

1 kg Nitrocellulose NIKE 115 (Nitrochemical Industrial Plants, Hungary) Gelatinated with 201% Dibutyl Phthalate 5 kg butanone 3 kg i-propyl acetate 5 kg n-butyl acetate 2 kg xylene 0.3 kg butyl stearate 0.2 kg alkyd resin (GALIKO BT GAA-2 type, Hungary)

From the solution, a film is drawn on a silicone paper used in the synthetic leather industry with a film-drawing frame of 50 µm slot size. After drying, the film is peeled off and the film's tensile strength and elongation at break are measured. Similarly, we also film film on a car enamel coated aluminum sheet. Again we apply enamel varnish to the surface of these films. The peeling force is measured at an angle of 180 ° to the film as is customary for self-adhesive films. The values obtained are shown in Table 1.

The rest of the solution is sprayed with 2 new Lada 1300 cars after favorable laboratory results. After applying the previous coat, wait 30 minutes at room temperature and then apply a new topcoat, which is a BUDALAKK enamel paint (vehicle lacquer) with modified alkyd resin-based noble pigments and additive based on BUDALAKK. 80, volatile material (105 ° C, 2 hours), min: 44%. Erichsen elasticity 5 (mm), Pendulum hardness (mm) 15.

From one car, the protective film (cut into pieces about 10 cm below) was pulled from the bottom up by hand while using a jet of water to help pull and release the film. In this way, the film could be removed from the entire surface of the vehicle in about 15 minutes. Underneath, the original coat of paint remained intact.

After another month of washing, the film was washed by hand in a conventional manner from the other car, and similarly easy to remove completely.

Example 2

Example 1 was performed and the results obtained are shown in Table 1. Composition of the coating in contact with the lacquered vehicle surface:

kg Mowilith DM 21 (Hoechst, BRD) Dispersion, Contains 50% Versatic Acid Vinyl Ester and Vinyl Acetate Copolymer

0.05 kg octanol

0.1 kg dibutyl sebacate kg methyl isobutyl ketone kg n-propyl acetate kg xylene kg methylcellosolve

The preparation of the solution was carried out with the difference as shown in Figure 1.

Compared to Example 1, the Mowilith dispersion was first dissolved in the cellulose and then the water was distilled off and then the other solvents were added to the solution.

As shown in Table 1, with the topcoat of Example 1, the coating has advantageous properties and can be completely removed from the vehicle.

Example 3

The inner layer was prepared and the resulting solution tested as described in Example 1. Composition of inner layer:

kg Galiko 14 (Galiko BT, Hungary) Methyl methacrylate and butyl acrylate copolymer powder

0.1 kg tributyl citrate kg ethanol kg methyl isobutyl ketone kg n-butyl acetate

0.2 kg alkyd resin (GAA-2 type,

Galiko BT, Hungary)

0.1 kg Ca-stearate

The protective film of Example 3 can also be peeled off the lacquered vehicle surface perfectly. (The topcoat is here too

It was as in Example 1.)

Example 4

120 g Butvar foil (Monsanto, USA, polyvinyl butyral) is cut into small pieces and placed in a 2 liter round bottom flask. To the flask was added 300 g of n-butyl acetate and 700 g of ethanol, and the contents were heated to the boiling point of ethanol with stirring and the components were allowed to dissolve while boiling the ethanol. The solution was filtered through a G-4 glass filter and cooled to dryness

At room temperature, add 1.0 g of benzoyl peroxide (component A).

In another vessel, weigh 5 g of 2-ethylhexanoic acid and 150 g of dipropylene glycol dimethacrylate (component "B").

Immediately before use, add Component B to Component A, then apply film to glass sheet and silicone paper as described in Example 1, and then spray-coat on automotive enameled body parts. The sprayed liquid mixture forms a film of 10-15 µm thickness which, at 80 ° C, obtains its final property about 30 minutes after absorption due to the onset of polymerization. For this, a two-component BUDALAKK resacrylic enamel was applied, which, after heat treatment, formed a 25-30 µm outer film. Rezacryl is an acrylate resin-based product crosslinked with a pigmented aliphatic isocyanate and crosslinked with an aliphatic polyisocyanate. The results of the laboratory samples are shown in Table 1. Attempts to peel off the surface were successful. The resilience of Rezacryl (Erichsen) (mm) is 6, the pendulum hardness (mm) is 40.

Example 5

The procedure of Example 4 is followed except that the composition of the inner layer is as follows:

Component A:

100 g Butaflex film (Fatra Napajedla, Czechoslovakia) (polyvinyl butyral) g VeoVa 10 acid (Versatic acid),

Shell make

500 g of toluene

500 g ethanol g azo-bis-isobutyronitrile Component B:

150 g of butyl methacrylate

150 g of trimethylolpropane triacrylate

Spraying a blended mixture of Components A and B and then treating the automotive components in a conventional drying tunnel after about 20 minutes results in a high quality lacquer. Spray BUDALAKK Metallux coating varnish “A” 001 and “B” 001 3: 1. Metallux "A" 001 contains a special acrylate resin cross-linked with an aliphatic isocyanate. Elasticity (Erichsen) (mm) 7, hardness (pendulum) 50.

The resulting film has a lower tensile elongation and a higher surface hardness than that of Example 4, although it can be easily removed from the coated surface in a similar manner.

Example 6

Component A of the solution for the inner layer of the coating was prepared as in Example 1, component B was prepared by homogenizing two liquids.

Component A:

0.5 kg GALIKO 14 (GALIKO BT, Hungary)

0.3 kg benzyl butyl phthalate

0.4 kg Versamid 140 (Schering AG., Austria) Epoxy resin crosslinker

0.1 kg Κ-2-ethylhexanoate kg ethanol kg toluene kg ethyl cellulose acetate Component B:

1.7 kg diethylene glycol diglycidyl ether (MÜKI, Hungary)

The Neolux enamel of Example 1 is sprayed and heat treated to provide high quality but manually peelable protective films.

Table 1

Test results of film layers

Example Solution movie- formation contain today (Wt%) Movie dry thick- saga (Pm) Tensile strength (N / mm ² ) sections Dasi strain (%) TgCC) Main- lia / inner + outer layer / peel power (N / cm) 1 + 9.09 9 3 500 0 2.2 2nd ++ 5.14 8 2 800 3 1.8 3 + 13.5 12 0.5 1200 <0 1.5 4th 21.6 10 5 1500 <0 3.4 5th 29.1 15 9 900 <0 4.1 6th 33.3 16 15 300 5 3.6 γ +++ 80.0 16 20 200 10 5.3 8 + 17.3 17 7 400 <0 4.5

⁺ filmmaking repeated so film can be examined ++ filmmaking twice repeated +++ filmmaking with 20 pm gap

Example 7

Composition of the solution used to make the inner film: Component A:

kg Neopentyl glycolbis-glycidyl ether (AH-14 MÜKI)

0.2 kg of epoxidized octiolate

0.15 kg toluene Component B:

0.4 kg Versamid 140

0.3 kg of dioctylphthalate

0.1 kg trioctyl phosphate

0.2 kg alkyd resin (GAA-12 type, Galikó BT) is saturated, modified with aminoplast.

Homogenization of the two components gives a spray solution which forms a film which cures within a few hours at room temperature. However, it is preferable to heat the film at 60-80 ° C for half an hour. Finally, as described in Example 1, NEOLUX enamel is applied and heat treated. so

841 A high quality protective film is formed which can be peeled off from the surface by hand; its properties are shown in Table 1.

Example 8

Composition of the solution for internal film Component A:

160g ethylcellulose (Hercules Co., USA)

200 g of medium gasoline (boiling range 60-110 ° C)

100 g ethanol

600 g toluene 100 g n-butanol g GAA-2 type alkyd resin component B:

g TMXDI (tetramethyl xylene)

(diisocyanate) prepolymer

American Cyanamid Comp., USA

100 g toluene g benzyl butyl phthalate

The inner film forming solution was prepared, applied, heat treated, and the outer film was formed as in Example 7. The properties of the resulting high quality film are shown in Table 1.

Claims (2)

PATIENT INDIVIDUAL POINTS A method for producing a film-like film-coating of a film thickness of between 10 and 100 µm on a freshly lacquered vehicle surface including rubber and / or plastic surfaces, characterized in that the polymeric monomer and / or oligomer and / or polymer film-forming film is a homogeneous solvent solution or dispersion for the vehicle surface to be protected. a varnish composition optionally containing additives, which is a linear film-forming film-forming agent, preferably a polymer having a molecular weight greater than 100,000, preferably nitrocellulose, ethylcellulose, polyvinyl ester, polyvinyl acetate, polyvinyl acetals, copolymers of vinyl esters and acrylic esters, and / or at most With a viscosity of 5000 mPas, mono-, di- or polyvinyl, boiling in the range of 100 ° C, preferably isopropyl methacrylate, butyl methacrylate, (poly) propylene glycol methacrylate 1, of vinyl carboxylic acid esters of polyhydric alcohols, preferably dipropylene glycol dimethacrylate, trimethylolpropane triacrylate, polypropylene glycol dimethacrylate and / or saturated polyesters having a viscosity of up to 50,000 mPas and / or their aminoplast modified derivatives and / or aliphatic polyurethane and / or epoxy resin, based on the film forming component 0.1 to 50% by weight C ₂₄ aliphatic saturated or unsaturated alkali or alkaline earth metal salt and / or C ₂ -C 6 fatty acid (s) ^_ C | ₈ aliphatic saturated synthetic monocarboxylic acid (s) and / or alkyd resin (s) made from the above products and dicarboxylic acids and / or C ₆ -C ₍₂ aliphatic, primary alcohol (s) and 0-100% by weight of the film former) At atmospheric pressure, it consists of varnish softeners with boiling point higher than 200 ° C and lacquer solvents with a boiling point of more than 50 ° C and a flash point of more than 21 ° C and a composition of 5-8 Erichsen (mm) as the coating. An outer layer of an aliphatic isocyanate crosslinked acrylic resin or an acrylic resin ester is sprayed from 10 to 60 hardened modified alkyd resins and cured at 5090 ° C for 10 minutes to 8 hours. 2. The method of claim 1, wherein the film-forming additive is used as a dye, light and heat stabilizer, with the restriction that the solids soluble in the solvent medium have a particle size of less than 30 µm, preferably less than 10 µm. Published by the National Inventory Office, Budapest Responsible for release: Gyurcsekné Philipp Clarisse Head of Division ARCANUM Databases - BUDAPEST