CS201066B1 - Surface treatment method of parts from polypropylene before sticking - Google Patents

Description

The invention relates to a method of surface treatment of polypropylene parts prior to gluing, in particular polypropylene lining with other parts.

In the prior art methods of treating polypropylene parts prior to bonding, various active agents are applied to the surface of the finished molded parts. The action of strong acids such as chromosulfuric acid, nitric acid, acetic acid, and the action of strong oxidizing agents, e.g. a mixture of sulfuric acid and nitric acid in a ratio of 1 · 4 to 1: 6, a mixture of hydrochloric acid and nitric acid in a ratio of 1 or 30% hydrogen peroxide solution. Furthermore, the interaction of halogenating agents, e.g. 3% trichloroisocyanuric acid solution. Impact of antioxidants on their surface as well as ozone, ultraviolet rays, electron stream and unsaturated acids and their salts such as acrylic, malonic and fumaric acid are also used to improve the stickability of the polypropylene products. Such a surface treatment of the polypropylene parts prior to bonding with other parts achieves a maximum bond strength of 30 N / 2.5 cm using current adhesives. The achieved bond strength is low and therefore polypropylene parts are not used in some areas, although other properties would be advantageous for this application. For this reason, e.g. they do not use polypropylene soles, as the prior clinging methods do not guarantee the necessary strength of the glued joint required for footwear.

201 066

201 Οββ

A substantial improvement in the bond strength of the polypropylene parts β by other parts is achieved by the process according to the invention, characterized in that the non-green part of the surface of the polypropylene parts is treated with a halogenating agent applied to the respective part of the mold cavity surface. .

The technical effect of the invention is to increase the strength of the glued joint of propylene parts with other parts and to extend the possibility of using propylene parts.

The portion of the surface of the mold cavity that shapes the surface of the polypropylene sole intended to be adhered to the upper of the shoe is coated with a 20% solution of trichloroisocyanuric acid in acetone before injection of the polypropylene. Due to the oxidative effects of the halogenating agent, it is necessary to form a protective coating on the surface of the mold cavity, e.g. Teflon. After the polypropylene has been injected, the halogenating agent during the molding of the sole in the mold cavity affects the respective portion of the sole. The molded sole remains in the mold for the same time as molding without the use of a halogenating agent. After pick! the soles of the mold cavity e and the surface of the mold cavity is again coated with a halogenating agent and the polypropylene is injected to form the sole sole. The respective part of the surface of the sole and the halogenating agent does not activate to such an extent that it can be glued by conventional epdsobom using a polyurethane adhesive with the addition of an isocyanate crosslinker, e.g. Vukoplaet D 418 and Desmodur R. The initial strength of the glued joint of the modified polypropylene sole with the leather upper is in the range of 50 to 70 N / 2.5 cm; 24 hours after the joint was formed, e is in the range of 70 to 100 N / 2.5 cm.

Claims (1)

OBJECT OF THE INVENTION Process for treating the surface of polypropylene parts prior to bonding with other parts by halogenating, characterized in that the subsequent glued part thereof is treated with a halogenating agent applied to the respective part of the mold cavity surface by forming the polypropylene parts in the mold cavity.