Cement mixtures for plugging honeycomb bodies and methods of making the same

A method for manufacturing a porous ceramic wall flow filter, comprising the steps of:

• selectively inserting a cement mixture into an end of at least one predetermined cell channel of a ceramic honeycomb structure, wherein the ceramic honeycomb structure comprises a matrix of intersecting porous ceramic walls which form a plurality of cell channels bounded by the porous ceramic walls that extend longitudinally from an upstream inlet end to a downstream outlet end, wherein the cement mixture comprises:
• (i) inorganic ceramic particles;
• (ii) an inorganic binder;
• (iii) an organic binder comprising:
• a hydrophilic polymer;
• and
• a hydrophilic additive comprising a polymer with a different composition than the composition of the hydrophilic polymer, the additive having a weight average molecular weight (Mw) of at least 1,000,000 g/mol;
• and
• (iv) an aqueous liquid vehicle, and wherein the cement mixture disposed in the at least one predetermined cell channel is in the form of at least one respective plug that blocks the respective at least one cell channel;
• and
• drying the at least one respective plug for a period of time sufficient to at least partially remove the aqueous liquid vehicle from the mixture.

A filter body comprising:

• a honeycomb structure that comprises intersecting porous walls of a first ceramic material that define channels extending from a first end to a second end;
• plugging material disposed in a first plurality of the channels at the first end;
• plugging material disposed in a second plurality of the channels at the second end, wherein the channels of the first plurality are distinct from the channels of the second plurality and the first plurality of channels have a first cross-sectional area that is different than a second cross-sectional area of the second plurality of channels, and
• wherein the plugging material in both the first plurality of channels and the second plurality of channels is derived from a cement mixture comprising:
• (i) inorganic ceramic particles;
• (ii) an inorganic binder;
• and
• (iii) an organic binder comprising:
• a hydrophilic polymer;
• and
• a hydrophilic additive comprising a polymer with a different composition than the composition of the hydrophilic polymer, the additive having a weight average molecular weight (Mw) of at least 1,000,000 g/mol;
• wherein:
• the hydrophilic polymer comprises at least one polymer selected from hydroxyethyl cellulose (HEC), methyl cellulose, carboxymethyl cellulose, hydroxypropyl cellulose, polysaccharides, and modified cellulose;
• and
• the hydrophilic additive comprises at least one polymer selected from polyethylene oxide (PEO), polyvinylpyrrolidone (PVP), a PEO-polypropylene oxide (PPO) block copolymer, and polypropylene oxide (PPO).