PL189345B1 - Water-dilutable polyurethane paints for use on wood and plastic - Google Patents

Abstract

The water-soluble polyurethane varnish products to be applied to wood and plastics contain coalescent solvents, moistening agents, froth-breaking and condensing agents, as well as pigments and fillers, in the case of pigmented products. Their amounts are adjusted to ensure the product has got the required properties. It is characterised in that the film-forming base of the product is constituted by: 40 - 90 percent by mass of colloidal water solutions of low-viscosity aliphatic or aromatic polyester or polyether polyurethanes, without free isocyanate groups, characterised by the lowest film-formation temperature of ~0 degrees Celsius and the sticking temperature of 160 - 200 degrees Celsius; 0 - 15 percent by mass of 100 percent hydrophilised aliphatic isocyanate resin, based on hexamethylene-diisocyanate, containing 16 - 20 percent of NCO groups.

Description

The subject of the invention are water-soluble polyurethane lacquer products for use on wood and plastics.

Solvent-based polyurethane varnishes have been known and used for painting wood for many years, and recently, for about 10 years, also water-soluble polyurethane varnishes.

Lacquer coatings obtained from the known water-based polyurethane lacquers have worse properties than lacquer coatings obtained from solvent-based lacquers. This especially applies to properties such as chemical resistance and abrasion resistance.

The water-soluble polyurethane varnish products according to the invention are based on special polyurethane dispersions which enable to obtain coatings with very good chemical resistance and abrasion resistance.

The use of a polyurethane dispersion in the products according to the invention in a two-component combination with a special water-dispersible isocyanate resin allows for even better properties of the coatings.

The products according to the invention contain 40% by weight of a special polyurethane dispersion and 0-15% by weight of an aliphatic isocyanate resin. Additionally, the products contain small amounts of coalescing solvents, wetting agents, defoamers and thickeners.

The products according to the invention may be pigmented with organic pigments, such as, for example, flalocyanin pigments and inorganic pigments, such as iron and titanium oxides, and may also contain mineral fillers.

The polyurethane dispersions used in the products according to the invention are aqueous, colloidal, low-viscous aliphatic or aromatic polyester or polyether polyurethanes without free isocyanate groups. The lowest film formation temperature ~ 0 ° C, gluing temperature 160 - 200 ° C.

These dispersions dry out physically through the formation of hydrogen bridges (tautomerism effect).

In order to obtain coatings with the best properties, the dispersions can be cured with the appropriate isocyanate.

The isocyanate resins used in the products according to the invention are 100% low viscosity hydrophilized aliphatic systems based on hexamethylene diisocyanate containing 16 - 20% NCO groups.

The products according to the invention are obtained by traditional methods, the products are pigment-free with the use of a stirrer, and pigmented with the use of bead mills or dissolvers.

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The products according to the invention are illustrated in more detail in the following examples.

Example I. Floor varnish

Component 1

Polyester-polyurethane dispersion 87.0 parts by weight Water 8.1 parts by weight Butylglycol (coalescent) 4.0 parts by weight An agent improving the wettability of the substrate 0.5 parts by weight Silicone defoamer 0.3 parts by weight Polyurethane thickening agent 0.1 parts by weight Component 2 Water-dispersible isocyanate resin 100.0 parts by weight containing 17% by NCO Example II. Wood varnish (one-component) 10.0 parts by weight Polyester-polyurethane (alicyclic) dispersion 87.0 parts by weight Water 8.1 parts by weight Butylglycol (coalescent) 4.0 parts by weight An agent improving the wettability of the substrate 0.5 parts by weight Silicone defoamer 0.3 parts by weight Polyurethane thickening agent 0.1 parts by weight

100.0 parts by weight

Example III. Wood enamel (two-component) Component 1

Polyurethane dispersion modified with fatty acids

Butylglycol (coalescent)

Water

Silicone defoamer

An agent improving the wettability of the substrate

Polyurethane thickening agent

Titanium white

Component 2

Water dispersible isocyanate resin with 17% NCO

70.0 parts by weight 5.0 parts by weight 6.0 parts by weight 0.5 parts by weight 0.3 parts by weight 0.2 parts by weight 18.0 parts by weight

100.0 parts by weight

10.0 parts by weight

Example IV. Two-component polyurethane varnish for furniture

Component 1 Aliphatic polycarbonate-polyurethane dispersion 85.0 parts by weight Water 8.7 parts by weight Butylglycol (coalescent) 5.0 parts by weight An agent improving the wettability of the substrate 0.5 parts by weight Silicone defoamer 0.5 parts by weight Polyurethane thickening agent 0.3 100.0 parts by weight parts by weight

Component 2

Water-dispersible isocyanate resin with 19% NCO

10.0 parts by weight

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The table below illustrates the properties of the coatings obtained from the products according to Examples I to W.

Table

Example AND II III IV Properties of the coating Konig coating hardness (after 72 h) 170 sec 165 sec 185 sec 160 sec Coating gloss, 60 ° 80 85 70 65 Abrasion resistance, Taber method CS 17 mg / 1000 units 15 50 thirty thirty Resistance to action (tampon method) of water 24 h 24 24 h 24 h 50% alcohol no change 6 h no change lh no change 1 h no change 6 h 5% acetic acid no change 16 h no change 6 h no change 6 h no change 16 h coffee without changing no change no change 1 h no change 16 h tea - no change 1 h no change no change 16 h no change

Publishing Department of the UP RP. Circulation of 50 copies

Price PLN 2.00.

Claims (1)

Patent claim Water-soluble polyurethane varnish products for applications on wood and plastics containing coalescing solvents, wetting, defoaming and thickening agents, and in the case of pigmented products, pigments and fillers, in amounts securing the production of a product with the desired properties, characterized by the fact that the film-forming base of the products is 40 - 90 % by weight of aqueous, colloidal, low-viscous aliphatic or aromatic polyester or polyether polyurethanes without free isocyanate groups with the lowest film forming temperature ~ 0 ° C and gluing temperature 160 - 200 ° C and 0 - 15% by weight 100% with hydrophilized aliphatic resin isocyanion based on hexamethylene diisocyanate containing 16 - 20% NCO groups.