Reactive phenolic resins in the preparation of highly viscous self-adhesive compositions
View Patent ↗Hot-melt pressure-sensitive adhesive based one or more non-thermoplastic elastomers, at least comprising 100 parts by mass of the non-thermoplastic elastomer(s), from 1 to 200 parts by mass of one or more tackifying resins, from 1 to 100 parts by mass of one or more reactive phenolic resins whose methylol content is from 1 to 20% by weight, based on the reactive phenolic resin, from 1 to 100 parts by mass of accelerator substances.
1. Hot-melt pressure-sensitive adhesive based on one or more non-thermoplastic elastomers, comprising at least
a) 100 parts by mass of one or more non-thermoplastic elastomers selected from the group consisting of natural rubbers, random-copolymerized styrene-butadiene rubbers (SBR), butadiene rubbers (BR), synthetic polyisoprenes (IR), butyl rubbers (IIR) and ethylene-vinyl acetate copolymers (EVA),
b) from 1 to 200 parts by mass of one or more tackifying resins,
c) from 1 to 100 parts by mass of one or more reactive phenolic resins whose methylol content is from 1 to 20% by weight based on the reactive phenolic resin, and
d) from 1 to 100 parts by mass of accelerator substances.
2. Hot-melt pressure-sensitive adhesive according to claim 1 , based on a polymer blend of one or more of the non-thermoplastic elastomers and one or more thermoplastic elastomers selected from the group consisting of polypropylenes, polyethylenes, metallocene-catalyzed polyolefins, polyesters, polystyrenes and synthetic block copolymer rubbers.
3. Hot-melt pressure-sensitive adhesive according to claim 1 , wherein the crosslinking accelerator substances are selected from the group consisting of chloroprenes, chlorinated butyl rubbers, brominated butyl rubbers, chlorosulphonated polyethylenes, metal oxides, organic acids or salts thereof, metal stearates and metal resinates.
4. Hot-melt pressure-sensitive adhesive according to claim 1 , wherein the reactive phenolic resins are halogenated and have a halogen content of from 1 to 20% by weight, based on the reactive phenolic resin.
5. Hot-melt pressure-sensitive adhesive according to claim 1 , wherein the reactive phenolic resin comprises a mixture of different reactive phenolic resins having different reactivities.
6. Hot-melt pressure-sensitive adhesive according to claim 1 , wherein fillers are added to the adhesive which are selected from the group consisting of metal oxides, chalks, precipitated or pyrogenic silicas, solid or hollow glass beads, microballoons, carbon blacks, glass fibers, polymer fibers and combinations thereof.
7. Hot-melt pressure-sensitive adhesive according to claim 1 , wherein plasticizers are added to the adhesive which are selected from the group consisting of paraffinic or naphthenic oils, oligomeric nitrile rubbers, liquid isoprene rubbers, oligobutadienes, soft resins, wool fats, rapeseed oils, castor oils and combinations thereof.
8. Self-adhesive article comprising the hot-melt pressure-sensitive adhesive of claim 1 applied to at least one side of a web-form material.
9. Self-adhesive article according to claim 8 , wherein the thickness of the hot-melt pressure-sensitive adhesive on the web-form material is between 5 μm and 3000 μm.
10. Self-adhesive article according to claim 9 , wherein the hot-melt sensitive adhesive is applied in a thickness of from 40 μm to 1500 μm to a release paper having an anti-adhesive coating on both sides.
11. Process for producing self-adhesive articles wherein the hot-melt pressure-sensitive adhesive of claim 1 is applied to a web form material with the aid of a multi-roll applicator unit which comprises from two to five rolls.