CS220977B1 - Method of treating the segments surface from polypropylene before pasting - Google Patents

Description

The invention relates to a method of surface treatment of polypropylene parts made by spraying or melt intrusion into a die cavity, in particular polypropylene soles and heels, prior to gluing with other parts such as soles, bollards, leather upper and coverings,

In the previously known methods of bonding of polypropylene parts, the surface of the polypropylene panels is impregnated with activating agents prior to bonding. It is known to treat strong acids such as ehromsulphuric acid, nitric acid, acetic acid, strong oxidizing agents such as nitric acid and sulfuric acid in a ratio of 41 = 1 and 6: 1, mixtures of hydrochloric acid and nitric acid. pomeire · 3: 1 or 30 ^fl / o hydrogen peroxide solution. Furthermore, the action of hailogenizing agents, for example a 3% solution of trichloroisocyanuric acid, is known. The action of amitioxidamides on their surface as well as ozone, ultraviolet lumens, electron currents, flame® and the effects of unsaturated fatty acids and their salts such as acrylic acid, malonic acid and fumaric acid are also used to improve the bondability of the polypropylene panels. This surface treatment of the polypropylene panels achieves a maximum bond strength of 30 N / 2.5 cm by the use of current adhesives. The bond strength achieved is insufficient. A substantial improvement in the bond strength between the polypropylene panels and other substrates is achieved by the action of a 210% solution of trichloroisocyanuric acid in aceiton on the polypropylene camber during molding, in the cavity of the die. The considerable aggressiveness of the formulation used limits the possibility of using this method in practice. It is also known to apply hot solvents or vapors thereof for 15 to 30 seconds to the surface of the polypropylene panels. A disadvantage of this method is the adverse effect of the solvent vapor on the working environment.

A further disadvantage of this method is that the surface treated in this way needs to be bonded to the chip in a relatively short time, as it rapidly loses the ability to anchor the adhesive well. In the event that the die does not stick to the next part in a short time, the glued surface needs to be reactivated.

These disadvantages are overcome by the method of surface treatment of the polypropylene panels prior to bonding with other substrates according to the invention. 20 parts by weight of low molecular weight chlorinated alkene are added. parts of polyehloroprene adhesive, composed of 16 to 20 wt. parts by weight of the epoxy resin, 6 to 8 wt. parts of modifying additives and 72 to 76 himot. parts by weight of solvent or polyurethane adhesive, composed of 16 to 23 parts by weight of a polyester-type linear polyurethane, 77 to 82 parts by weight; parts of solvents and 3 to 8 wt. parts of an isocyanate crosslinker.

The technical effect consists mainly in the fact that permanently anchored adhesive substances remain on the surface of the parts, whereby the adhesive time is significantly reduced. Furthermore, the adverse effect of the hot vapors on the working environment will be substantially reduced.

For the sake of clarity, the following are examples of the use of the method of bonding polypropylene panels to other substrates of the invention.

Example 1

The sole of the creeper type molded from polypropylene is allowed to reach 110 ° C in a continuous tempering chamber. The tempered sole will be lined up. It is immersed in a 45% solution of URLEP.1 polychloroprene adhesive in itetria-aluminum-ethylene at normal temperature of the solution for 20 seconds. The tetrachlorethylene present in the solution activates the surface of the heated polypropylene part and the adhesive present allows the adhesive to be bonded in place to adhere the adhesive insole according to the regulations applicable to said type of adhesive, and an adhesive having a reduced content of the base polymer component may be used.

Example 1, d 2

The heel of the polypropylene spout is brought to a temperature of 110 ° C and immersed in a 30% solution of VUKOPLAST D-418 polyurethane adhesive mixed with 8 wt. the perceint of the crosslinker Desmodiur RF at 1,2,3-trichloropiropema at normal temperature of the solution for 15 seconds. The 1,2,3-chlorofluoropropene present in the solution activates the surface of the heated polypropylene panel and the adhesive present allows the bonding between the paddle and the leather coatings to be made, the regulations applicable to that type of adhesive have been complied with. An adhesive with a proportionally reduced content of polymer component may be hardened to further deposition.

The polychlonoprene adhesive consists of chloropirene rubber, modifying additives and solvents. The polyurethane adhesive comprises linear polyester-type polyurethane, solvents and an isocyanate crosslinker.

The initial strength of the bonded joint is in the range of 30 'to 50 N / 2, 5', the final bond strength, i.e., 24 hours after formation of the joint, ranges from 100 to 150 N / 2.5 cm and tear of the materials adhered to the polypropylene die during tear tests.

Claims (1)

SUBJECT S, acts on the surface treatment of the polypropylene panels prior to bonding with other substrates. by the action of low molecular weight chlorinated alkenes having a carbon number of 2 to 4 at a temperature of 70 to 110 ° C, characterized in that per 100 wt. 20 parts to 50% by weight of low molecular weight chlorinated alkene are added. parts of polychloroprene adhesive, composite 18 OF THE INVENTION up to 20 wt. parts by weight of chloroprene rubber, 6 to 8 wt. parts of the modifiers in the kit and up to 72 to 76 wt. % of parts of solvents, or polyuirethane adhesive, composed of: 18 to 23 wt. of polyester-type liner polyurethane, 77 to 82 wt. die lov roizppustaidiel and 3 to 8 hmoit. parts of the isocyanate network of the vehicle.