BINDING AGENT Russian patent published in 2022 - IPC C08F255/08 C08F10/02 B32B27/32 

FIELD: chemistry.

SUBSTANCE: present invention relates to a new binding agent, which is multimodal linear low-density polyethylene (hereinafter – LLDPE), to which an acidic grafting agent is grafted; to composite materials containing the specified binding agent; a method for the production of grafted LLDPE, and to the use of grafted multimodal LLDPE (hereinafter – g-LLDPE) as a binding agent in composite material. This LLDPE is copolymer of ethylene and at least one alpha-olefin comonomer. LLDPE density is from 915 to 950 kg/m³. LLDPE is obtained using Ziegler-Natt catalyst. LLDPE has MFI₂ from 0.05 to 50g/10 min. The binding agent contains multimodal LLDPE, and LLDPE is a single polymer component in the binding agent. Composite material contains a binding agent containing g-LLDPE or consisting of it. This method for the production of grafted LLDPE includes obtainment of LLDPE and grafted polymerization of LLDPE with the acidic grafting agent. Obtainment of LLDPE includes stages of: (i) homopolymerization of ethylene or copolymerization of ethylene and at least one alpha-olefin comonomer at the first polymerization stage in the presence of Ziegler-Natt catalyst to obtain the first ethylene homo- or copolymer; (ii) copolymerization of ethylene and at least one alpha-olefin comonomer at the second polymerization stage in the presence of the first ethylene homo- or copolymer and the same Ziegler-Natt catalyst as at the stage (i) to obtain the specified LLDPE containing the first ethylene homo- or copolymer and the second ethylene copolymer. The comonomer content in the second ethylene copolymer is the same or exceeds the comonomer content in the first ethylene homo- or copolymer. The first polymerization stage can be carried out for one or two polymerization cycles in a loop reactor, and the second polymerization stage is carried out in a gas phase reactor.

EFFECT: development of grafted multimodal linear low-density polyethylene having high viscosity, multimodal distribution of branching points, and relatively high rigidity.

24 cl, 1 tbl, 7 ex