PL160247B1 - Alkyd-carbamide lacquer - Google Patents

Abstract

Alkyd-carbamide lacquer agent for coating steel surfaces which were previously coated with passive layer, containing a two-component adhesive for pigments and fillers composed of modified alkyd resin or the mixture of such resins - as the first component, whose presence in the adhesive amounts to 48.6-49.0 parts by weight, and amino resins - as the second component characterised in that the content of the second component, i.e. amino resins, in the adhesive is 8.0-8.2 of the same parts by weight.

Description

The subject of the invention is an alkyd-carbamide varnish agent for covering steel surfaces previously covered with a passive layer, giving smooth coatings that do not require grinding.

There are known varnish agents for covering metal objects, which, after being painted, create a varnish layer that protects against corrosion and damaging effects of external factors, or for decorative purposes. The quality requirements for the painted element have a decisive impact on the proper selection of a set of varnish products, as well as determining the painting technology in strictly defined conditions, namely: coating drying time, drying temperature, determining the thickness and number of layers in the set, as well as determining the method of applying varnish coatings.

For these purposes, varnish agents based on modified organic binders consisting of phthalic, epoxy ester, epoxy and polyester resins with the addition of amino and urea cross-linking resins, acid hardeners, polyamide resins, or aromatic or aliphatic polyamines are used.

An example of such a varnish agent is the composition described in U.S. Patent No. 2,218,474, in which the binder consists of a modified alkyd resin in an amount of 85-40 parts by weight and a cross-linking amino resin in an amount of 15-60 parts by weight.

These known paints based on a modified alkyd resin did not meet the requirements for high-quality car paints as defined in the relevant standards for the automotive industry. In particular, they do not provide coatings of sufficient quality or it is difficult from a technological point of view to obtain coatings meeting the high requirements. For example, it is difficult to achieve proper adhesion between the individual layers of applied varnishes, which is very important when painting motor vehicles. During painting, surface defects in the form of cratering, poor flow and drainage from vertical surfaces often occur, and the resulting coatings usually require grinding and polishing.

Surprisingly, the research showed that the reason for the described disadvantages of known varnishes based on modified alkyd resins is a large proportion of the cross-linking component in the binder of the varnish, including also amino resins fulfilling this role. This unexpected finding was used for the realization of the present invention, the aim of which was to obtain a paint meeting the high demands of automotive paints, drying in 10 minutes at a temperature of 120-130 ° C and creating smooth coatings that do not require sanding.

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According to the invention, the content of the cross-linking component in the composition of the lacquer binder is significantly reduced, the agent according to the invention contains a two-component binder, in which the first component is a modified alkyd resin or a mixture of resins of this type taken in an amount of 4B, 6, 49.0 parts by weight, the second component is a resin or The amino resins (crosslinkers) are distinguished by the fact that the content of the second component, i.e. the amino resins, in the binder is Θ - 8.2 of the same parts by weight.

The varnish agent according to the invention, after application to the substrate and drying at a temperature of 120-130 ° C, forms a varnish coat that perfectly levels surface unevenness and does not require sanding. The coating has very good mechanical and chemical properties as well as high corrosion resistance, this agent creates coatings that fully meet the requirements of the standards for car paints, in terms of the stability of painted products, protection against corrosion, does not require sanding layers and dries in a suitable time 10 minutes at a temperature lower than usual, varnishes of this type, already at a temperature of 120-130 ° C. It also shows a very high resistance to water and moisture.

The following examples illustrate the nature, properties and advantages of lacquers based on the lacquer composition of the invention.

Example I. A varnish based on a varnish agent was prepared with the following composition: a modified alkyd resin containing 43¾ of dehydrated castor oil in the form of a 30¾ solution in butanol and xylene in the amount of 48.6 parts by weight, and a highly reactive melamine resin etherified with butanol in the form of a 30 solution in butanol in an amount of 8.00 parts by weight. In addition to this lacquer agent, the lacquer contained the following components in the following amounts, expressed in parts by weight, the same as the components of the lacquer formulation:

- aluminosilicate - 14.00

- Rutil titanium oxide - 14.00

- varnish silica / aerosil / - 0.44

- varnish carbon blacks - 0.03

- non-silicone dispersant - 0.18

- butyl alcohol - 3.00

- ethylglycol - 2.90

- xylene - 8.85

The paint components together accounted for 100 parts by weight. Accelerated corrosion-resistant coatings were obtained in a 5 sol salt mist solution at 30 ° C according to the Polish Standard PN-78 / C-91531. These coatings showed very good adhesion of 1 according to the Polish Standard PN-80 / C-B1531, drawability of 8 mm according to the Polish Standard PN-80 / C-81531, flexibility of 2 according to the Polish Standard PN-76 / C-81528 and impact strength of 50 kg / cm according to the Polish Standard PN-54 / C-B1526. The coatings are also characterized by high thickness and very good interlayer adhesion, they are suitable for various application techniques, while the lacquer binder itself is stable for a minimum period of 24 months.

Example II. A varnish based on a varnish agent was made. Composition: modified alkyd resin with 40 o of dehydrated castor oil in the form of a 50¾ solution in solvent naphtha and 32.60 parts by weight, a modified alkyd resin containing 45¾ of dehydrated castor oil in the form of a 50¾ solution in solvent naphtha, of butanol and xylene in the amount of 16.4 parts by weight and from the network of melamine etherified with butanol in the amount of 8.2 oz: with 5 parts of a solution in buSrnol. Logically as in Example 1, the varnish was wiped off with the number of times in parts by weight:

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- titanium oxide 'Rutil

- varnish silica

- the dispersing agent was carried by Iconowy

- aluminosilicate

- butyl alcohol

- 16.00

- 0.50

- 0.18 - 16.00

3.00

- ethylglycol

- soot

- xylene

- 2.50

- 0.03

4.59

The coatings obtained from the varnish according to example 2 are particularly highly resistant to aging and corrosion. Tested according to the standards mentioned in Example 1, they showed an adhesion of 1 (very good), a drawability of 8 mm, an elasticity of 2 and an impact strength of 50 kg / cm. Similarly to the coatings according to example 1, they are characterized by high thickness, very good interlayer adhesion, they are suitable for various application techniques, and the lacquer agent is stable for a minimum period of 24 months.

Department of Publishing of the UP RP. Circulation of 90 copies. Price: PLN 10,000

Claims (1)

Claimed alkyd-carbamide varnish agent for coating steel surfaces previously covered with a passivating layer, containing a two-component binder for pigments and fillers consisting of a modified alkyd resin or a mixture of such resins as the first component, the content of which in the binder is 48.6 - 49.0 parts by weight and with amino resins as the second component, characterized in that the content of the second component, i.e. the amino resins, in the binder is 8.0 - 8.2 with the same parts by weight. «« *