Amphoteric Polymer Blend for Paper Strength in High-Conductivity Papermaking

The patent divides the single polymer into two different amphoteric (meth)acrylamide polymers with different molecular weights (first polymer with weight-average molecular weight of 1,500,000 to 10,000,000 and second polymer with weight-average molecular weight of 1,500,000 to 10,000,000 but different viscosity characteristics). This segmentation allows each polymer to contribute differently to the overall performance, with the mixture providing both low-viscosity flowability and high-viscosity strengthening effects, thereby achieving reliable paper-strengthening across varying electrical conductivity conditions.

The patent creates a composite paper-strengthening agent by combining two different amphoteric (meth)acrylamide polymers in a specific ratio (first polymer:second polymer by weight is 95:5 to 50:50). This composite formulation leverages the complementary properties of both polymers to achieve superior performance in high electrical conductivity environments where single polymers fail, while maintaining effectiveness in low conductivity environments as well.

The patent segments the viscosity contribution into two separate polymers with different viscosity characteristics. The first polymer provides base viscosity and strengthening, while the second polymer (with higher viscosity at lower concentrations) provides enhanced strengthening only when needed. This segmentation prevents excessive viscosity buildup that would cause cloudiness and insoluble substance formation, while still achieving adequate paper strength.

The patent changes the viscosity parameter dynamically through the mixture ratio of the two polymers. By adjusting the ratio of first polymer to second polymer (95:5 to 50:50), the overall viscosity of the paper-strengthening agent can be optimized to provide sufficient strength without excessive viscosity that would cause harmful effects like cloudiness and insoluble substance formation in high electrical conductivity environments.

The patent segments the polymer population into two distinct molecules with different molecular weights and viscosity characteristics. This segmentation creates a more versatile agent that can navigate high electrical conductivity environments better, as the mixture provides both low-viscosity components that can access ion sites and high-viscosity components that provide structural strengthening, thereby compensating for ion shielding effects.

The patent formulates a composite paper-strengthening agent combining two amphoteric (meth)acrylamide polymers in specific ratios (95:5 to 50:50 by weight). This composite material leverages the synergistic effects of both polymers to overcome ion shielding by calcium ions, providing sufficient paper-strengthening effect in high electrical conductivity environments where single polymers are ineffective.