Method of producing slurry, method of producing composite resin material, and method of producing shaped product
Provided is a method of producing a slurry that enables simple production of a slurry in which fibrous carbon nanostructures are favorably dispersed. The method of producing a slurry includes: a mixing step of mixing resin particles having an average particle diameter of at least 1 μm and not more than 700 μm, fibrous carbon nanostructures, and a dispersion medium to obtain a mixed liquid; and a dispersing step of subjecting the mixed liquid to dispersion treatment using a wet medialess disperser under conditions in which pressure acting on the mixed liquid (gauge pressure) is 5 MPa or less to obtain a slurry. The fibrous carbon nanostructures preferably include carbon nanotubes.
1. A method of producing a slurry comprising:
a mixing step of mixing resin particles having an average particle diameter of at least 1 μm and not more than 700 μm, fibrous carbon nanostructures, and a dispersion medium to obtain a mixed liquid; and
a dispersing step of subjecting the mixed liquid to dispersion treatment using a wet medialess disperser, wherein the wet medialess disperser performs wet dispersion treatment without using dispersing media under conditions in which pressure acting on the mixed liquid, in terms of gauge pressure, is 5 MPa or less to obtain a slurry, wherein
the wet medialess disperser is a rotary homogenizer or an inline rotor-stator mixer including a fixed stator and a rotor that rotates at high speed in opposition to the stator.
2. The method of producing a slurry according to claim 1 , wherein content of the resin particles in the mixed liquid is at least 1 mass% and not more than 30 mass%.
3. The method of producing a slurry according to claim 1 , wherein a Hansen solubility parameter distance R of the dispersion medium and a resin forming the resin particles, obtained by formula (1) shown below, is at least 2 and not more than 14,
R={ 4×(δ d1 −δ d2 ) 2 +(δ p1 −δ p2 ) 2 +(δ h1 −δ h2 ) 2 } 1/2 (1)
where where δ d1 is dispersion term of the resin, δ d2 is a dispersion term of the dispersion medium, δ p1 is a polarity term of the resin, δ p2 is a polarity term of the dispersion medium, δ h1 is a hydrogen bonding term of the resin, and δ h2 is a hydrogen bonding term of the dispersion medium.
4. The method of producing a slurry according to claim 1 , wherein the mixed liquid contains the fibrous carbon nanostructures in a proportion of at least 0.01 parts by mass and not more than 10 parts by mass per 100 parts by mass of the resin particles.
5. The method of producing a slurry according to claim 1 , wherein the resin particles are fluororesin particles, acrylic resin particles, polycarbonate resin particles, or cycloolefin resin particles.
6. A method of producing a composite resin material comprising a step of removing the dispersion medium from a slurry produced using the method of producing a slurry according to claim 1 to form a composite resin material.
7. A method of producing a shaped product comprising a step of shaping a composite resin material produced using the method of producing a composite resin material according to claim 6 .
8. The method of producing a slurry according to claim 1 , wherein that the mixed liquid does not contain dispersing agent, or dispersants other than dispersion medium.